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Pranav M, Shukla A, Moser D, Rumeney J, Liu W, Wang R, Sun B, Smeets S, Tokmoldin N, Cao Y, He G, Beitz T, Jaiser F, Hultzsch T, Shoaee S, Maes W, Lüer L, Brabec C, Vandewal K, Andrienko D, Ludwigs S, Neher D. On the critical competition between singlet exciton decay and free charge generation in non-fullerene based organic solar cells with low energetic offsets. ENERGY & ENVIRONMENTAL SCIENCE 2024; 17:6676-6697. [PMID: 39157178 PMCID: PMC11323475 DOI: 10.1039/d4ee01409j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Accepted: 07/16/2024] [Indexed: 08/20/2024]
Abstract
Reducing voltage losses while maintaining high photocurrents is the holy grail of current research on non-fullerene acceptor (NFA) based organic solar cell. Recent focus lies in understanding the various fundamental mechanisms in organic blends with minimal energy offsets - particularly the relationship between ionization energy offset (ΔIE) and free charge generation. Here, we quantitatively probe this relationship in multiple NFA-based blends by mixing Y-series NFAs with PM6 of different molecular weights, covering a broad power conversion efficiency (PCE) range: from 15% down to 1%. Spectroelectrochemistry reveals that a ΔIE of more than 0.3 eV is necessary for efficient photocurrent generation. Bias-dependent time-delayed collection experiments reveal a very pronounced field-dependence of free charge generation for small ΔIE blends, which is mirrored by a strong and simultaneous field-dependence of the quantified photoluminescence from the NFA local singlet exciton (LE). We find that the decay of singlet excitons is the primary competition to free charge generation in low-offset NFA-based organic solar cells, with neither noticeable losses from charge-transfer (CT) decay nor evidence for LE-CT hybridization. In agreement with this conclusion, transient absorption spectroscopy consistently reveals that a smaller ΔIE slows the NFA exciton dissociation into free charges, albeit restorable by an electric field. Our experimental data align with Marcus theory calculations, supported by density functional theory simulations, for zero-field free charge generation and exciton decay efficiencies. We conclude that efficient photocurrent generation generally requires that the CT state is located below the LE, but that this restriction is lifted in systems with a small reorganization energy for charge transfer.
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Affiliation(s)
- Manasi Pranav
- Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht Straße 24/25 14476 Potsdam Germany
| | - Atul Shukla
- Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht Straße 24/25 14476 Potsdam Germany
| | - David Moser
- IPOC - Functional Polymers, Institute of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Julia Rumeney
- IPOC - Functional Polymers, Institute of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Wenlan Liu
- Max Planck Institute for Polymer Research, Ackermannweg 10 55128 Mainz Germany
| | - Rong Wang
- Institute of Materials for Electronics and Energy Technology (i-MEET), Friedrich-Alexander-Universität Erlangen-Nürnberg, Martensstrasse 7 Erlangen 91058 Germany
| | - Bowen Sun
- Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht Straße 24/25 14476 Potsdam Germany
| | - Sander Smeets
- UHasselt-Hasselt University, Institute for Materials Research, (IMO-IMOMEC), Agoralaan 1 3590 Diepenbeek Belgium
- IMOMEC Division, IMEC, Wetenschapspark 1 3590 Diepenbeek Belgium
| | - Nurlan Tokmoldin
- Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht Straße 24/25 14476 Potsdam Germany
- Heterostructure Semiconductor Physics, Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e. V, Hausvogteiplatz 5-7 10117 Berlin Germany
| | - Yonglin Cao
- Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht Straße 24/25 14476 Potsdam Germany
| | - Guorui He
- Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht Straße 24/25 14476 Potsdam Germany
| | - Thorben Beitz
- Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht Straße 24/25 14476 Potsdam Germany
| | - Frank Jaiser
- Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht Straße 24/25 14476 Potsdam Germany
| | - Thomas Hultzsch
- Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht Straße 24/25 14476 Potsdam Germany
| | - Safa Shoaee
- Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht Straße 24/25 14476 Potsdam Germany
- Heterostructure Semiconductor Physics, Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e. V, Hausvogteiplatz 5-7 10117 Berlin Germany
| | - Wouter Maes
- UHasselt-Hasselt University, Institute for Materials Research, (IMO-IMOMEC), Agoralaan 1 3590 Diepenbeek Belgium
- IMOMEC Division, IMEC, Wetenschapspark 1 3590 Diepenbeek Belgium
| | - Larry Lüer
- Institute of Materials for Electronics and Energy Technology (i-MEET), Friedrich-Alexander-Universität Erlangen-Nürnberg, Martensstrasse 7 Erlangen 91058 Germany
| | - Christoph Brabec
- Institute of Materials for Electronics and Energy Technology (i-MEET), Friedrich-Alexander-Universität Erlangen-Nürnberg, Martensstrasse 7 Erlangen 91058 Germany
- Helmholtz-Institut Erlangen-Nürnberg for Renewable Energies (HIERN), Forschungszentrum Jülich, Immerwahrstraße 2 91058 Erlangen Germany
| | - Koen Vandewal
- UHasselt-Hasselt University, Institute for Materials Research, (IMO-IMOMEC), Agoralaan 1 3590 Diepenbeek Belgium
- IMOMEC Division, IMEC, Wetenschapspark 1 3590 Diepenbeek Belgium
| | - Denis Andrienko
- Max Planck Institute for Polymer Research, Ackermannweg 10 55128 Mainz Germany
| | - Sabine Ludwigs
- IPOC - Functional Polymers, Institute of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55 70569 Stuttgart Germany
| | - Dieter Neher
- Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht Straße 24/25 14476 Potsdam Germany
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2
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Han JH, Zhou HP, Wang LL, Zhao ZW, Liu XM, Pan QQ, Su ZM. The superiority of isomeric, fluorination and curtailed π-conjunction on A-D-A type acceptors for organic photovoltaics. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024; 325:125043. [PMID: 39236567 DOI: 10.1016/j.saa.2024.125043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 07/30/2024] [Accepted: 08/24/2024] [Indexed: 09/07/2024]
Abstract
The performance of organic solar cell (OSC) devices has been significantly enhanced by the dramatic evolution of A-D-A type non-fullerene acceptors (NFAs). Nevertheless, the structure-property-performance relationship of NFAs in the OSC device is unclear. Here, the intrinsic design factors of isomeric, fluorination and π-conjunction curtailing on the photophysical properties of benzodi (thienopyran) (BDTP) (named NBDTP-M, NBDTTP-M, NBDTP-Fin, and NBDTP-Fout)-based NFAs are discussed. The results show that fluorination on the terminal group of NBDTP-Fout could effectively decrease the highest occupied orbital (HOMO) energy level and the lowest unoccupied orbital (LUMO) energy level. And the long π-conjugated donor unit for NBDTTP-M could increase the HOMO energy level and bring a small HOMO-LUMO energy bandgap. Meanwhile, the substitution of external oxygen atoms and the fluorine atoms in the terminal group could introduce positive changes to the electrostatic potential of the NBDTP-Fout, favouring the charge separation at the donor/acceptor interface. Moreover, the structural design of external oxygen atom substitution, fluorination on the terminal group and curtailed π-conjugated donor unit could decrease the electron vibration-coupling of exciton diffusion, exciton dissociation and electronic transfer processes. The suppression of the exciton decay and charge recombination in those high-performance NFAs indicate that the investigated molecular designs could be effective for further improvement of OSCs.
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Affiliation(s)
- Jin-Hong Han
- School of Chemistry and Environmental Engineering, Changchun University of Science and Technology, Jilin Provincial Science and Technology Innovation Center of Optical Materials and Chemistry, Jilin Provincial International Joint Research Center of Photo-functional Materials and Chemistry, Changchun 130022, China
| | - Hai-Ping Zhou
- School of Chemistry and Environmental Engineering, Changchun University of Science and Technology, Jilin Provincial Science and Technology Innovation Center of Optical Materials and Chemistry, Jilin Provincial International Joint Research Center of Photo-functional Materials and Chemistry, Changchun 130022, China
| | - Li-Li Wang
- School of Chemistry and Environmental Engineering, Changchun University of Science and Technology, Jilin Provincial Science and Technology Innovation Center of Optical Materials and Chemistry, Jilin Provincial International Joint Research Center of Photo-functional Materials and Chemistry, Changchun 130022, China
| | - Zhi-Wen Zhao
- College of Chemical Engineering, Hubei University of Arts and Science, Xiangyang 441053, China; School of Materials Science and Engineering, Changchun University of Science and Technology, Changchun 130022, China.
| | - Xing-Man Liu
- School of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China
| | - Qing-Qing Pan
- School of Chemistry and Environmental Engineering, Changchun University of Science and Technology, Jilin Provincial Science and Technology Innovation Center of Optical Materials and Chemistry, Jilin Provincial International Joint Research Center of Photo-functional Materials and Chemistry, Changchun 130022, China.
| | - Zhong-Min Su
- School of Chemistry and Environmental Engineering, Changchun University of Science and Technology, Jilin Provincial Science and Technology Innovation Center of Optical Materials and Chemistry, Jilin Provincial International Joint Research Center of Photo-functional Materials and Chemistry, Changchun 130022, China; State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun 130021, China.
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3
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Li J, Ji Q, Wang R, Zhang ZG, Wang X, Xiao M, Lu YQ, Zhang C. Charge Generation Dynamics in Organic Photovoltaic Blends under One-Sun-Equivalent Illumination Detected by Highly Sensitive Terahertz Spectroscopy. J Am Chem Soc 2024; 146:20312-20322. [PMID: 38980945 DOI: 10.1021/jacs.4c05786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/11/2024]
Abstract
Organic photovoltaic (OPV) devices attain high performance with nonfullerene acceptors by utilizing the synergistic dual channels of charge generation that originate from excitations in both the donor and acceptor materials. However, the specific intermediate states that facilitate both channels are subject to debate. To address this issue, we employ time-resolved terahertz spectroscopy with improved sensitivity (ΔE/E < 10-6), enabling direct probing of charge generation dynamics in a prototypical PM6:Y6 bulk heterojunction system under one-sun-equivalent excitation density. Charge generation arising from donor excitations is characterized with a rise time of ∼9 ps, while that from acceptor excitations shows a rise time of ∼18 ps. Temperature-dependent measurements further reveal notably distinct activation energies for these two charge generation pathways. Additionally, the two channels of charge generation can be substantially manipulated by altering the ratio of bulk to interfaces. These findings strongly suggest the presence of two distinct intermediate states: interfacial and intramoiety excitations. These states are crucial in mediating the transfer of electrons and holes, driving charge generation within OPV devices.
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Affiliation(s)
- Jiacong Li
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Qing Ji
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Rui Wang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing 210093, China
- College of Physics, Nanjing University of Aeronautics and Astronautics, and Key Laboratory of Aerospace Information Materials and Physics (NUAA), MIIT, Nanjing 211106, China
- Institute of Materials Engineering, Nanjing University, Nantong, Jiangsu 226019, China
| | - Zhi-Guo Zhang
- State Key Laboratory of Organic/Inorganic Composites, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Xiaoyong Wang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Min Xiao
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing 210093, China
- Department of Physics, University of Arkansas, Fayetteville, Arkansas 72701, United States
| | - Yan-Qing Lu
- National Laboratory of Solid State Microstructures, Key Laboratory of Intelligent Optical Sensing and Manipulation, College of Engineering and Applied Sciences, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210023, China
| | - Chunfeng Zhang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing 210093, China
- Institute of Materials Engineering, Nanjing University, Nantong, Jiangsu 226019, China
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4
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Xu L, Li S, Zhao W, Xiong Y, Yu J, Qin J, Wang G, Zhang R, Zhang T, Mu Z, Zhao J, Zhang Y, Zhang S, Kuvondikov V, Zakhidov E, Peng Q, Wang N, Xing G, Gao F, Hou J, Huang W, Wang J. The Role of Solution Aggregation Property toward High-Efficiency Non-Fullerene Organic Photovoltaic Cells. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2403476. [PMID: 38666554 DOI: 10.1002/adma.202403476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Revised: 04/16/2024] [Indexed: 05/07/2024]
Abstract
In organic photovoltaic cells, the solution-aggregation effect (SAE) is long considered a critical factor in achieving high power-conversion efficiencies for polymer donor (PD)/non-fullerene acceptor (NFA) blend systems. However, the underlying mechanism has yet to be fully understood. Herein, based on an extensive study of blends consisting of the representative 2D-benzodithiophene-based PDs and acceptor-donor-acceptor-type NFAs, it is demonstrated that SAE shows a strong correlation with the aggregation kinetics during solidification, and the aggregation competition between PD and NFA determines the phase separation of blend film and thus the photovoltaic performance. PDs with strong SAEs enable earlier aggregation evolutions than NFAs, resulting in well-known polymer-templated fibrillar network structures and superior PCEs. With the weakening of PDs' aggregation effects, NFAs, showing stronger tendencies to aggregate, tend to form oversized domains, leading to significantly reduced external quantum efficiencies and fill factors. These trends reveal the importance of matching SAE between PD and NFA. The aggregation abilities of various materials are further evaluated and the aggregation ability/photovoltaic parameter diagrams of 64 PD/NFA combinations are provided. This work proposes a guiding criteria and facile approach to match efficient PD/NFA systems.
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Affiliation(s)
- Lei Xu
- Key Laboratory of Flexible Electronics (KLOFE), Institute of Advanced Materials (IAM) & School of Flexible Electronics (Future Technologies), Nanjing Tech University (Nanjing Tech), Nanjing, 211816, China
| | - Sunsun Li
- Key Laboratory of Flexible Electronics (KLOFE), Institute of Advanced Materials (IAM) & School of Flexible Electronics (Future Technologies), Nanjing Tech University (Nanjing Tech), Nanjing, 211816, China
| | - Wenchao Zhao
- Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, 210037, China
| | - Yaomeng Xiong
- Key Laboratory of Flexible Electronics (KLOFE), Institute of Advanced Materials (IAM) & School of Flexible Electronics (Future Technologies), Nanjing Tech University (Nanjing Tech), Nanjing, 211816, China
| | - Jinfeng Yu
- Key Laboratory of Flexible Electronics (KLOFE), Institute of Advanced Materials (IAM) & School of Flexible Electronics (Future Technologies), Nanjing Tech University (Nanjing Tech), Nanjing, 211816, China
| | - Jinzhao Qin
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Gang Wang
- Joint Key Laboratory of the Ministry of Education, Institute of Applied Physics and Materials Engineering, University of Macau, Avenida da Universidade, Taipa, Macau, 999078, China
| | - Rui Zhang
- Department of Physics, Chemistry and Biology (IFM), Linköping University, Linköping, SE-58183, Sweden
| | - Tao Zhang
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Zhen Mu
- Joint Key Laboratory of the Ministry of Education, Institute of Applied Physics and Materials Engineering, University of Macau, Avenida da Universidade, Taipa, Macau, 999078, China
| | - Jingjing Zhao
- Key Laboratory of Flexible Electronics (KLOFE), Institute of Advanced Materials (IAM) & School of Flexible Electronics (Future Technologies), Nanjing Tech University (Nanjing Tech), Nanjing, 211816, China
| | - Yuyang Zhang
- Key Laboratory of Flexible Electronics (KLOFE), Institute of Advanced Materials (IAM) & School of Flexible Electronics (Future Technologies), Nanjing Tech University (Nanjing Tech), Nanjing, 211816, China
| | - Shaoqing Zhang
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Vakhobjon Kuvondikov
- Institute of Ion-Plasma and Laser Technologies, Uzbekistan Academy of Sciences, 33 Durmon yuli, Tashkent, 100125, Uzbekistan
| | - Erkin Zakhidov
- Institute of Ion-Plasma and Laser Technologies, Uzbekistan Academy of Sciences, 33 Durmon yuli, Tashkent, 100125, Uzbekistan
| | - Qiming Peng
- Key Laboratory of Flexible Electronics (KLOFE), Institute of Advanced Materials (IAM) & School of Flexible Electronics (Future Technologies), Nanjing Tech University (Nanjing Tech), Nanjing, 211816, China
| | - Nana Wang
- Key Laboratory of Flexible Electronics (KLOFE), Institute of Advanced Materials (IAM) & School of Flexible Electronics (Future Technologies), Nanjing Tech University (Nanjing Tech), Nanjing, 211816, China
| | - Guichuan Xing
- Joint Key Laboratory of the Ministry of Education, Institute of Applied Physics and Materials Engineering, University of Macau, Avenida da Universidade, Taipa, Macau, 999078, China
| | - Feng Gao
- Department of Physics, Chemistry and Biology (IFM), Linköping University, Linköping, SE-58183, Sweden
| | - Jianhui Hou
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Wei Huang
- Key Laboratory of Flexible Electronics (KLOFE), Institute of Advanced Materials (IAM) & School of Flexible Electronics (Future Technologies), Nanjing Tech University (Nanjing Tech), Nanjing, 211816, China
- Shaanxi Institute of Flexible Electronics (SIFE), Xi'an Institute of Biomedical Materials and Engineering (IBME), Northwestern Polytechnical University (NPU), Xi'an, 710072, China
| | - Jianpu Wang
- Key Laboratory of Flexible Electronics (KLOFE), Institute of Advanced Materials (IAM) & School of Flexible Electronics (Future Technologies), Nanjing Tech University (Nanjing Tech), Nanjing, 211816, China
- School of Materials Science and Engineering & School of Microelectronics and Control Engineering, Changzhou University, Changzhou, Jiangsu, 213164, China
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5
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Jungbluth A, Cho E, Privitera A, Yallum KM, Kaienburg P, Lauritzen AE, Derrien T, Kesava SV, Habib I, Pratik SM, Banerji N, Brédas JL, Coropceanu V, Riede M. Limiting factors for charge generation in low-offset fullerene-based organic solar cells. Nat Commun 2024; 15:5488. [PMID: 38942793 PMCID: PMC11213929 DOI: 10.1038/s41467-024-49432-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Accepted: 06/05/2024] [Indexed: 06/30/2024] Open
Abstract
Free charge generation after photoexcitation of donor or acceptor molecules in organic solar cells generally proceeds via (1) formation of charge transfer states and (2) their dissociation into charge separated states. Research often either focuses on the first component or the combined effect of both processes. Here, we provide evidence that charge transfer state dissociation rather than formation presents a major bottleneck for free charge generation in fullerene-based blends with low energetic offsets between singlet and charge transfer states. We investigate devices based on dilute donor content blends of (fluorinated) ZnPc:C60 and perform density functional theory calculations, device characterization, transient absorption spectroscopy and time-resolved electron paramagnetic resonance measurements. We draw a comprehensive picture of how energies and transitions between singlet, charge transfer, and charge separated states change upon ZnPc fluorination. We find that a significant reduction in photocurrent can be attributed to increasingly inefficient charge transfer state dissociation. With this, our work highlights potential reasons why low offset fullerene systems do not show the high performance of non-fullerene acceptors.
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Affiliation(s)
- Anna Jungbluth
- Department of Physics, The University of Oxford, Oxford, Oxfordshire, OX13PJ, UK
| | - Eunkyung Cho
- Department of Chemistry and Biochemistry, The University of Arizona, Tucson, AZ, 85721-0088, USA
- Division of Energy Technology, DGIST, Daegu, 42988, Republic of Korea
| | - Alberto Privitera
- Department of Physics, The University of Oxford, Oxford, Oxfordshire, OX13PJ, UK
- Department of Industrial Engineering and INSTM Research Unit, University of Florence, 50139, Firenze, Italy
| | - Kaila M Yallum
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, 3012, Bern, Switzerland
| | - Pascal Kaienburg
- Department of Physics, The University of Oxford, Oxford, Oxfordshire, OX13PJ, UK
| | - Andreas E Lauritzen
- Department of Physics, The University of Oxford, Oxford, Oxfordshire, OX13PJ, UK
| | - Thomas Derrien
- Diamond Light Source, Didcot, Oxfordshire, OX11 0DE, UK
- Living Systems Institute, University of Exeter, Exeter, EX4 4QD, UK
| | - Sameer V Kesava
- Department of Physics, The University of Oxford, Oxford, Oxfordshire, OX13PJ, UK
| | - Irfan Habib
- Department of Physics, The University of Oxford, Oxford, Oxfordshire, OX13PJ, UK
| | - Saied Md Pratik
- Department of Chemistry and Biochemistry, The University of Arizona, Tucson, AZ, 85721-0088, USA
| | - Natalie Banerji
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, 3012, Bern, Switzerland
| | - Jean-Luc Brédas
- Department of Chemistry and Biochemistry, The University of Arizona, Tucson, AZ, 85721-0088, USA
| | - Veaceslav Coropceanu
- Department of Chemistry and Biochemistry, The University of Arizona, Tucson, AZ, 85721-0088, USA
| | - Moritz Riede
- Department of Physics, The University of Oxford, Oxford, Oxfordshire, OX13PJ, UK.
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6
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Shoaee S, Luong HM, Song J, Zou Y, Nguyen TQ, Neher D. What We have Learnt from PM6:Y6. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2302005. [PMID: 37623325 DOI: 10.1002/adma.202302005] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 07/10/2023] [Indexed: 08/26/2023]
Abstract
Over the past three years, remarkable advancements in organic solar cells (OSCs) have emerged, propelled by the introduction of Y6-an innovative A-DA'D-A type small molecule non-fullerene acceptor (NFA). This review provides a critical discussion of the current knowledge about the structural and physical properties of the PM6:Y6 material combination in relation to its photovoltaic performance. The design principles of PM6 and Y6 are discussed, covering charge transfer, transport, and recombination mechanisms. Then, the authors delve into blend morphology and degradation mechanisms before considering commercialization. The current state of the art is presented, while also discussing unresolved contentious issues, such as the blend energetics, the pathways of free charge generation, and the role of triplet states in recombination. As such, this review aims to provide a comprehensive understanding of the PM6:Y6 material combination and its potential for further development in the field of organic solar cells. By addressing both the successes and challenges associated with this system, this review contributes to the ongoing research efforts toward achieving more efficient and stable organic solar cells.
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Affiliation(s)
- Safa Shoaee
- Optoelectronics of Disordered Semiconductors, Institute of Physics and Astronomy, University of Potsdam, D-14476, Potsdam-Golm, Germany
- Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V., 10117, Berlin, Germany
| | - Hoang M Luong
- Centre for Polymers and Organic Solids, University of California, Santa Barbara, CA, 93106, USA
| | - Jiage Song
- College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, P. R. China
| | - Yingping Zou
- College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, P. R. China
| | - Thuc-Quyen Nguyen
- Centre for Polymers and Organic Solids, University of California, Santa Barbara, CA, 93106, USA
| | - Dieter Neher
- Soft Matter Physics and Optoelectronics, Institute of Physics and Astronomy, University of Potsdam, D-14476, Potsdam-Golm, Germany
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7
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Shi J, Sun K, Chen Z, Qiu Y, Liu H, Ma W, Liu Q, Ge Z. The Influence of Donor/Acceptor Interfaces on Organic Solar Cells Efficiency and Stability Revealed through Theoretical Calculations and Morphology Characterizations. Angew Chem Int Ed Engl 2024; 63:e202318360. [PMID: 38189578 DOI: 10.1002/anie.202318360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 01/05/2024] [Accepted: 01/08/2024] [Indexed: 01/09/2024]
Abstract
End-groups halogenation strategies, generally refers to fluorination and chlorination, have been confirmed as simple and efficient methods to regulate the photoelectric performance of non-fullerene acceptors (NFAs), but a controversy over which one is better has existed for a long time. Here, two novel NFAs, C9N3-4F and C9N3-4Cl, featured with different end-groups were successfully synthesized and blended with two renowned donors, D18 and PM6, featured with different electron-withdrawing units. Detailed theoretical calculations and morphology characterizations of the interface structures indicate NFAs based on different end-groups possess different binding energy and miscibility with donors, which shows an obvious influence on phase-separation morphology, charge transport behavior and device performance. After verified by other three pairs of reported NFAs, a universal conclusion obtained as the devices based on D18 with fluorination-end-groups-based NFAs and PM6 with chlorination-end-groups-based NFAs generally show excellent efficiencies, high fill factors and stability. Finally, the devices based on D18: C9N3-4F and PM6: C9N3-4Cl yield outstanding efficiency of 18.53 % and 18.00 %, respectively. Suitably selecting donor and regulating donor/acceptor interface can accurately present the photoelectric conversion ability of a novel NFAs, which points out the way for further molecular design and selection for high-performance and stable organic solar cells.
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Affiliation(s)
- Jingyu Shi
- Zhejiang Provincial Engineering Research Center of Energy Optoelectronic Materials and Devices, Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Zhejiang, 315201, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Kexuan Sun
- Zhejiang Provincial Engineering Research Center of Energy Optoelectronic Materials and Devices, Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Zhejiang, 315201, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Zhenyu Chen
- Zhejiang Provincial Engineering Research Center of Energy Optoelectronic Materials and Devices, Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Zhejiang, 315201, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Yi Qiu
- Zhejiang Provincial Engineering Research Center of Energy Optoelectronic Materials and Devices, Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Zhejiang, 315201, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Hui Liu
- Zhejiang Provincial Engineering Research Center of Energy Optoelectronic Materials and Devices, Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Zhejiang, 315201, P. R. China
| | - Wei Ma
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Quan Liu
- Zhejiang Provincial Engineering Research Center of Energy Optoelectronic Materials and Devices, Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Zhejiang, 315201, P. R. China
| | - Ziyi Ge
- Zhejiang Provincial Engineering Research Center of Energy Optoelectronic Materials and Devices, Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Zhejiang, 315201, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
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8
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Lüer L, Wang R, Liu C, Dube H, Heumüller T, Hauch J, Brabec CJ. Maximizing Performance and Stability of Organic Solar Cells at Low Driving Force for Charge Separation. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2305948. [PMID: 38039433 PMCID: PMC10853714 DOI: 10.1002/advs.202305948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 10/19/2023] [Indexed: 12/03/2023]
Abstract
Thanks to the development of novel electron acceptor materials, the power conversion efficiencies (PCE) of organic photovoltaic (OPV) devices are now approaching 20%. Further improvement of PCE is complicated by the need for a driving force to split strongly bound excitons into free charges, causing voltage losses. This review discusses recent approaches to finding efficient OPV systems with minimal driving force, combining near unity quantum efficiency (maximum short circuit currents) with optimal energy efficiency (maximum open circuit voltages). The authors discuss apparently contradicting results on the amount of exciton binding in recent literature, and approaches to harmonize the findings. A comprehensive view is then presented on motifs providing a driving force for charge separation, namely hybridization at the donor:acceptor interface and polarization effects in the bulk, of which quadrupole moments (electrostatics) play a leading role. Apart from controlling the energies of the involved states, these motifs also control the dynamics of recombination processes, which are essential to avoid voltage and fill factor losses. Importantly, all motifs are shown to depend on both molecular structure and process conditions. The resulting high dimensional search space advocates for high throughput (HT) workflows. The final part of the review presents recent HT studies finding consolidated structure-property relationships in OPV films and devices from various deposition methods, from research to industrial upscaling.
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Affiliation(s)
- Larry Lüer
- Institute of Materials for Electronics and Energy Technology (i‐MEET)Friedrich‐Alexander‐Universität Erlangen‐NürnbergMartensstrasse 791058ErlangenGermany
| | - Rong Wang
- Institute of Materials for Electronics and Energy Technology (i‐MEET)Friedrich‐Alexander‐Universität Erlangen‐NürnbergMartensstrasse 791058ErlangenGermany
- Erlangen Graduate School in Advanced Optical Technologies (SAOT)Paul‐Gordan‐Straße 691052ErlangenGermany
| | - Chao Liu
- Institute of Materials for Electronics and Energy Technology (i‐MEET)Friedrich‐Alexander‐Universität Erlangen‐NürnbergMartensstrasse 791058ErlangenGermany
| | - Henry Dube
- Department Chemistry and PharmacyFriedrich‐Alexander‐Universität Erlangen‐NürnbergNikolaus‐Fiebiger‐Straße 1091058ErlangenGermany
| | - Thomas Heumüller
- Institute of Materials for Electronics and Energy Technology (i‐MEET)Friedrich‐Alexander‐Universität Erlangen‐NürnbergMartensstrasse 791058ErlangenGermany
| | - Jens Hauch
- Helmholtz‐Institute Erlangen‐Nürnberg (HI‐ERN)Immerwahrstraße 291058ErlangenGermany
| | - Christoph J. Brabec
- Institute of Materials for Electronics and Energy Technology (i‐MEET)Friedrich‐Alexander‐Universität Erlangen‐NürnbergMartensstrasse 791058ErlangenGermany
- Helmholtz‐Institute Erlangen‐Nürnberg (HI‐ERN)Immerwahrstraße 291058ErlangenGermany
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9
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Zhang KN, Du XY, Yan L, Pu YJ, Tajima K, Wang X, Hao XT. Organic Photovoltaic Stability: Understanding the Role of Engineering Exciton and Charge Carrier Dynamics from Recent Progress. SMALL METHODS 2024; 8:e2300397. [PMID: 37204077 DOI: 10.1002/smtd.202300397] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Revised: 04/25/2023] [Indexed: 05/20/2023]
Abstract
Benefiting from the synergistic development of material design, device engineering, and the mechanistic understanding of device physics, the certified power conversion efficiencies (PCEs) of single-junction non-fullerene organic solar cells (OSCs) have already reached a very high value of exceeding 19%. However, in addition to PCEs, the poor stability is now a challenging obstacle for commercial applications of organic photovoltaics (OPVs). Herein, recent progress made in exploring operational mechanisms, anomalous photoelectric behaviors, and improving long-term stability in non-fullerene OSCs are highlighted from a novel and previously largely undiscussed perspective of engineering exciton and charge carrier pathways. Considering the intrinsic connection among multiple temporal-scale photocarrier dynamics, multi-length scale morphologies, and photovoltaic performance in OPVs, this review delineates and establishes a comprehensive and in-depth property-function relationship for evaluating the actual device stability. Moreover, this review has also provided some valuable photophysical insights into employing the advanced characterization techniques such as transient absorption spectroscopy and time-resolved fluorescence imagings. Finally, some of the remaining major challenges related to this topic are proposed toward the further advances of enhancing long-term operational stability in non-fullerene OSCs.
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Affiliation(s)
- Kang-Ning Zhang
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong, 250100, P. R. China
| | - Xiao-Yan Du
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong, 250100, P. R. China
| | - Lei Yan
- Academy for Advanced Interdisciplinary Studies and Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, P. R. China
| | - Yong-Jin Pu
- RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Keisuke Tajima
- RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Xingzhu Wang
- Academy for Advanced Interdisciplinary Studies and Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, P. R. China
- School of Electrical Engineering, University of South China, Hengyang, 421001, P. R. China
| | - Xiao-Tao Hao
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong, 250100, P. R. China
- ARC Centre of Excellence in Exciton Science, School of Chemistry, The University of Melbourne, Parkville, Victoria, 3010, Australia
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10
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Li C, Zhao Y, Song Y, Qiu X, Wang S, Sun P. Optimization of Electron Transport Pathway: A Novel Strategy to Solve the Photocorrosion of Ag-Based Photocatalysts. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:18626-18635. [PMID: 36853926 DOI: 10.1021/acs.est.2c07012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Although Ag-containing photocatalysts exhibit excellent photocatalytic ability, they present great challenges owing to their photocorrosion and ease of reduction. Herein, an electron acceptor platform of Ag2O/La(OH)3/polyacrylonitrile (PAN) fiber was constructed using a heterojunction strategy and electrospinning technology to develop a novel photocatalytic membrane with a redesigned electron transport pathway. Computational and experimental results demonstrate that the optimized electron transport pathway included intercrystal electron transfer induced by the La-O bond between Ag2O and La(OH)3 as well as electron transfer between the catalyst crystal and electrophilic PAN membrane interface. In addition, the photocatalytic performance of the Ag2O/La(OH)3 membrane for tetracycline (TC) removal was still above 97% after five photocatalytic reaction cycles. Furthermore, the carrier life was greatly extended. Mechanistic study revealed that photogenerated holes on the Ag2O/La(OH)3 membrane were the main reactive species in TC degradation. Overall, this study proposes a novel electron transport pathway strategy that effectively solves the problems of photocatalyst photocorrosion and structural instability.
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Affiliation(s)
- Chenxi Li
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Yingxin Zhao
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Yanxing Song
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Xiaojie Qiu
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Shuaize Wang
- Hongzhiwei Technology (Shanghai) Co. Ltd., Shanghai 200000, China
| | - Peizhe Sun
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
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11
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Müller K, Schellhammer KS, Gräßler N, Debnath B, Liu F, Krupskaya Y, Leo K, Knupfer M, Ortmann F. Directed exciton transport highways in organic semiconductors. Nat Commun 2023; 14:5599. [PMID: 37699907 PMCID: PMC10497625 DOI: 10.1038/s41467-023-41044-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 08/21/2023] [Indexed: 09/14/2023] Open
Abstract
Exciton bandwidths and exciton transport are difficult to control by material design. We showcase the intriguing excitonic properties in an organic semiconductor material with specifically tailored functional groups, in which extremely broad exciton bands in the near-infrared-visible part of the electromagnetic spectrum are observed by electron energy loss spectroscopy and theoretically explained by a close contact between tightly packing molecules and by their strong interactions. This is induced by the donor-acceptor type molecular structure and its resulting crystal packing, which induces a remarkable anisotropy that should lead to a strongly directed transport of excitons. The observations and detailed understanding of the results yield blueprints for the design of molecular structures in which similar molecular features might be used to further explore the tunability of excitonic bands and pave a way for organic materials with strongly enhanced transport and built-in control of the propagation direction.
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Affiliation(s)
- Kai Müller
- Center for Advancing Electronics Dresden, Technische Universität Dresden, 01062, Dresden, Germany
- Institut für Theoretische Physik, Technische Universität Dresden, 01062, Dresden, Germany
| | - Karl S Schellhammer
- Center for Advancing Electronics Dresden, Technische Universität Dresden, 01062, Dresden, Germany
- Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Institute for Applied Physics, Technische Universität Dresden, 01062, Dresden, Germany
| | - Nico Gräßler
- Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Institute for Applied Physics, Technische Universität Dresden, 01062, Dresden, Germany
- Leibniz Institute for Solid State and Materials Research Dresden, Helmholtzstr. 20, 01069, Dresden, Germany
| | - Bipasha Debnath
- Leibniz Institute for Solid State and Materials Research Dresden, Helmholtzstr. 20, 01069, Dresden, Germany
| | - Fupin Liu
- Leibniz Institute for Solid State and Materials Research Dresden, Helmholtzstr. 20, 01069, Dresden, Germany
| | - Yulia Krupskaya
- Leibniz Institute for Solid State and Materials Research Dresden, Helmholtzstr. 20, 01069, Dresden, Germany
| | - Karl Leo
- Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Institute for Applied Physics, Technische Universität Dresden, 01062, Dresden, Germany
| | - Martin Knupfer
- Leibniz Institute for Solid State and Materials Research Dresden, Helmholtzstr. 20, 01069, Dresden, Germany
| | - Frank Ortmann
- Center for Advancing Electronics Dresden, Technische Universität Dresden, 01062, Dresden, Germany.
- Department of Chemistry, TUM School of Natural Sciences, Technische Universität München, Lichtenbergstr. 4, 85748, Garching b. München, Germany.
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12
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Li D, Xiong S, Peng B, Liu W, Li B, Bao Q. Revealing Charge-Transfer Dynamics at Buried Charge-Selective Heterointerface in Highly Effective Perovskite Solar Cells. J Phys Chem Lett 2023; 14:7953-7959. [PMID: 37646609 DOI: 10.1021/acs.jpclett.3c02138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
The suboptimal carrier dynamics at the heterointerface between the perovskite and charge transport layer severely limit further performance enhancement of the state-of-the-art perovskite solar cells (PSCs). Herein, we completely map charge carrier extraction and recombination kinetics over a broad time range at buried electron-selective heterointerfaces via ultrafast transient technologies. It is revealed that the heterointerfaces carefully contain the electronic processes of free charge generation in perovskite within ∼2.8 ps, relaxation process of trap-state induced electron capturing less than ∼10.0 ps, electron extraction from perovskite to SnO2 within ∼194 ps, trap-assisted recombination within ∼2047 ps, and recombination between back-injected electrons and remaining holes within ∼8.4 ns. Moreover, we further demonstrate that the inserted poly(vinyl alcohol) (PVA) thin layer can effectively enhance the electron extraction from perovskite to SnO2, block the undesired electron back injection, and significantly suppress the nonradiative recombination, contributing to the improved device parameters of photovoltage and fill factor. This work sheds light on charge-transfer limitations at the perovskite buried heterointerface and provides an effective guide of ideal heterointerface design for promoting charge transfer and improving PSC performance.
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Affiliation(s)
- Di Li
- Key Laboratory of Polar Materials and Devices, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China
| | - Shaobing Xiong
- School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China
- Shanghai Frontiers Science Research Base of Intelligent Optoelectronics and Perception, Institute of Optoelectronics, Department of Materials Science, Fudan University, Shanghai 200433, China
| | - Bo Peng
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Weimin Liu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Bo Li
- Key Laboratory of Polar Materials and Devices, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China
| | - Qinye Bao
- School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China
- Shanghai Frontiers Science Research Base of Intelligent Optoelectronics and Perception, Institute of Optoelectronics, Department of Materials Science, Fudan University, Shanghai 200433, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
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13
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Müller J, Comí M, Eisner F, Azzouzi M, Herrera Ruiz D, Yan J, Attar SS, Al-Hashimi M, Nelson J. Charge-Transfer State Dissociation Efficiency Can Limit Free Charge Generation in Low-Offset Organic Solar Cells. ACS ENERGY LETTERS 2023; 8:3387-3397. [PMID: 37588019 PMCID: PMC10425975 DOI: 10.1021/acsenergylett.3c00943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 07/06/2023] [Indexed: 08/18/2023]
Abstract
We investigate the charge-generation processes limiting the performance of low-offset organic bulk-heterojunction solar cells by studying a series of newly synthesized PBDB-T-derivative donor polymers whose ionisation energy (IE) is tuned via functional group (difluorination or cyanation) and backbone (thiophene or selenophene bridge) modifications. When blended with the acceptor Y6, the series present heterojunction donor-acceptor IE offsets (ΔEIE) ranging from 0.22 to 0.59 eV. As expected, small ΔEIE decrease nonradiative voltage losses but severely suppresses photocurrent generation. We explore the origin of this reduced charge-generation efficiency at low ΔEIE through a combination of opto-electronic and spectroscopic measurements and molecular and device-level modeling. We find that, in addition to the expected decrease in local exciton dissociation efficiency, reducing ΔEIE also strongly reduces the charge transfer (CT) state dissociation efficiency, demonstrating that poor CT-state dissociation can limit the performance of low-offset heterojunction solar cells.
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Affiliation(s)
- Jolanda
Simone Müller
- Department
of Physics and Centre for processable Electronics, Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2AZ, United Kingdom
| | - Marc Comí
- Department
of Arts and Sciences, Texas A&M University
at Qatar, Education City,
P.O. Box 23874, Doha, Qatar
| | - Flurin Eisner
- Department
of Physics and Centre for processable Electronics, Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2AZ, United Kingdom
| | - Mohammed Azzouzi
- Department
of Physics and Centre for processable Electronics, Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2AZ, United Kingdom
| | - Diego Herrera Ruiz
- Department
of Physics and Centre for processable Electronics, Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2AZ, United Kingdom
| | - Jun Yan
- Department
of Physics and Centre for processable Electronics, Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2AZ, United Kingdom
- School
of Science and Engineering, The Chinese
University of Hong Kong, Shenzhen, Guangdong Province 518172, P. R. China
| | | | - Mohammed Al-Hashimi
- Department
of Arts and Sciences, Texas A&M University
at Qatar, Education City,
P.O. Box 23874, Doha, Qatar
| | - Jenny Nelson
- Department
of Physics and Centre for processable Electronics, Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2AZ, United Kingdom
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14
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Wang K, Xu C, Liu W, Yuan J, Zou Y, Yang Y. Observation of an Exciton-Plasma Transition in a Molecular Semiconductor. J Phys Chem Lett 2023:5607-5612. [PMID: 37307380 DOI: 10.1021/acs.jpclett.3c01330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The nonfullerene electron acceptors (NFAs) for organic solar cells are attracting intense research efforts due to their impressive performance. Understanding the temporal evolution of the excited states in NFAs is essential to gain insights into the working mechanism of these state-of-the-art devices. Here we characterized the photoconductivities of a neat Y6 film and a Y6:PM6 blend film using time-resolved terahertz spectroscopy. Three different types of excited states were identified based on their distinct terahertz responses, i.e., plasma-like carriers, weakly bound excitons, and spatially separated carriers. Under high-intensity excitation, the many-body interaction of excitons in the Y6 film leads to the plasma-like state, giving rise to a terahertz response characteristic for a dispersive charge transport. This transient state decays quickly into exciton gas due to fast Auger annihilation. Under low-intensity excitation, only isolated excitons are created and the plasma state is absent.
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Affiliation(s)
- Kang Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Chaoying Xu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Wei Liu
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China
| | - Jun Yuan
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China
| | - Yingping Zou
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China
| | - Ye Yang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
- Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen 361005, China
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15
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Ji Y, Mu X, Yin H, Cui B, Hao X, Gao K. Revealing the Role of Donor/Acceptor Interfaces in Nonfullerene-Acceptor Based Organic Solar Cells: Charge Separation versus Recombination. J Phys Chem Lett 2023; 14:3811-3817. [PMID: 37057899 DOI: 10.1021/acs.jpclett.3c00282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Organic solar cells (OSCs) based on nonfullerene-acceptors (NFAs) have achieved rapid development, while the role of donor/acceptor (D/A) interfaces in NFA based heterosystems has not been fully addressed. Here, we clarify that the photoinduced spontaneous charge separation efficiency in typical NFA heterosystems can reach up to 67%, and the charge separation efficiency contributed by the D/A interface is only 25%. The more important role of D/A interfaces is reducing the charge recombination rate, especially optimizing the competition between radiative and nonradiative charge recombination, thus reducing the nonradiative voltage loss. Systematical simulations demonstrate that there exists an optimal interfacial distance for a fixed energy offset, at which the D/A interface can reduce the nonradiative voltage loss by a maximum value of 0.12 V. Hence, we propose that optimizing the interfacial distance combined with the actual interfacial energy offset of a given heterosystem is important to develop its best photovoltaic performance.
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Affiliation(s)
- Yiwen Ji
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
| | - Xinyu Mu
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
| | - Hang Yin
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
| | - Bin Cui
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
| | - Xiaotao Hao
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
| | - Kun Gao
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
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16
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Lowrie W, Westbrook RJE, Guo J, Gonev HI, Marin-Beloqui J, Clarke TM. Organic photovoltaics: The current challenges. J Chem Phys 2023; 158:110901. [PMID: 36948814 DOI: 10.1063/5.0139457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2023] Open
Abstract
Organic photovoltaics are remarkably close to reaching a landmark power conversion efficiency of 20%. Given the current urgent concerns regarding climate change, research into renewable energy solutions is crucially important. In this perspective article, we highlight several key aspects of organic photovoltaics, ranging from fundamental understanding to implementation, that need to be addressed to ensure the success of this promising technology. We cover the intriguing ability of some acceptors to undergo efficient charge photogeneration in the absence of an energetic driving force and the effects of the resulting state hybridization. We explore one of the primary loss mechanisms of organic photovoltaics-non-radiative voltage losses-and the influence of the energy gap law. Triplet states are becoming increasingly relevant owing to their presence in even the most efficient non-fullerene blends, and we assess their role as both a loss mechanism and a potential strategy to enhance efficiency. Finally, two ways in which the implementation of organic photovoltaics can be simplified are addressed. The standard bulk heterojunction architecture could be superseded by either single material photovoltaics or sequentially deposited heterojunctions, and the attributes of both are considered. While several important challenges still lie ahead for organic photovoltaics, their future is, indeed, bright.
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Affiliation(s)
- William Lowrie
- Department of Chemistry, University College London, Christopher Ingold Building, London WC1H 0AJ, United Kingdom
| | - Robert J E Westbrook
- Department of Chemistry, University of Washington, Seattle, Washington 98195, USA
| | - Junjun Guo
- Department of Chemistry, University College London, Christopher Ingold Building, London WC1H 0AJ, United Kingdom
| | - Hristo Ivov Gonev
- Department of Chemistry, University College London, Christopher Ingold Building, London WC1H 0AJ, United Kingdom
| | - Jose Marin-Beloqui
- Departamento de Química Física, Universidad de Malaga, Campus Teatinos s/n, 29071 Málaga, Spain
| | - Tracey M Clarke
- Department of Chemistry, University College London, Christopher Ingold Building, London WC1H 0AJ, United Kingdom
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17
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Yuk D, Jee MH, Koh CW, Park WW, Ryu HS, Lee D, Cho S, Rasool S, Park S, Kwon OH, Kim JY, Woo HY. Simplified Y6-Based Nonfullerene Acceptors: In-Depth Study on Molecular Structure-Property Relation, Molecular Dynamics Simulation, and Charge Dynamics. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2206547. [PMID: 36541782 DOI: 10.1002/smll.202206547] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 11/25/2022] [Indexed: 06/17/2023]
Abstract
Two new Y6 derivatives of symmetrical YBO-2O and asymmetrical YBO-FO nonfullerene acceptors (NFAs) are prepared with a simplified synthetic procedure by incorporating octyl and fluorine substituents onto the terminal 2-(3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile (INCN) moiety. By moving the alkyl substituents on the Y6 core to the terminal INCN moiety, the lowest unoccupied molecular orbital of the YBO NFAs increases without decreasing solubility, resulting in high open-circuit voltages of the devices. Molecular dynamics simulation shows that YBO-2O/-FO preferentially form core-core and terminal-terminal dimeric interactions, demonstrating their tighter packing structure and higher electron mobility than Y6, which is consistent with 2D grazing incidence X-ray scattering and space charge limited current measurements. In blend films, the hole transfer (HT) from YBO-2O/-FO to the polymer donor PM6 is studied in detail by transient absorption spectroscopy, demonstrating efficient HT from YBO-FO to PM6 with their suitable energy level alignment. Despite the simplified synthesis, YBO-FO demonstrates photovoltaic performance similar to that of Y6, exhibiting a power conversion efficiency of 15.01%. Overall, this design strategy not only simplifies the synthetic procedures but also adjusts the electrical properties by modifying the intermolecular packing and energy level alignment, suggesting a novel simplified molecular design of Y6 derivatives.
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Affiliation(s)
- Dohun Yuk
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Min Hun Jee
- Department of Chemistry, Research Institute of Natural Science, Korea University, Seoul, 136-713, Republic of Korea
| | - Chang Woo Koh
- Department of Chemistry, Research Institute of Natural Science, Korea University, Seoul, 136-713, Republic of Korea
| | - Won-Woo Park
- Department of Chemistry, College of Natural Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Hwa Sook Ryu
- Department of Chemistry, Research Institute of Natural Science, Korea University, Seoul, 136-713, Republic of Korea
| | - Dongchan Lee
- Department of Physics and EHSRC, University of Ulsan, Ulsan, 44610, Republic of Korea
| | - Shinuk Cho
- Department of Physics and EHSRC, University of Ulsan, Ulsan, 44610, Republic of Korea
| | - Shafket Rasool
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Sungnam Park
- Department of Chemistry, Research Institute of Natural Science, Korea University, Seoul, 136-713, Republic of Korea
| | - Oh-Hoon Kwon
- Department of Chemistry, College of Natural Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Jin Young Kim
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
- Graduate School of Carbon Neutrality, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Han Young Woo
- Department of Chemistry, Research Institute of Natural Science, Korea University, Seoul, 136-713, Republic of Korea
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, 02841, Republic of Korea
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18
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Xiao C, Wang X, Zhong T, Zhou R, Zheng X, Liu Y, Hu T, Luo Y, Sun F, Xiao B, Liu Z, Yang C, Yang R. Hybrid Cycloalkyl-Alkyl Chain-Based Symmetric/Asymmetric Acceptors with Optimized Crystal Packing and Interfacial Exciton Properties for Efficient Organic Solar Cells. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2206580. [PMID: 36592412 PMCID: PMC9982590 DOI: 10.1002/advs.202206580] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 12/08/2022] [Indexed: 06/17/2023]
Abstract
Hybrid cycloalkyl-alkyl side chains are considered a unique composite side-chain system for the construction of novel organic semiconductor materials. However, there is a lack of fundamental understanding of the variations in the single-crystal structures as well as the optoelectronic and energetic properties generated by the introduction of hybrid side chains in electron acceptors. Herein, symmetric/asymmetric acceptors (Y-C10ch and A-C10ch) bearing bilateral and unilateral 10-cyclohexyldecyl are designed, synthesized, and compared with the symmetric acceptor 2,2'-((2Z,2'Z)-((12,13-bis(2-butyloctyl)-3,9 bis(ethylhexyl)-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2″,3″':4',5']thieno[2',3':4,5] pyrrolo[3,2-g]thieno[2',3':4,5]thieno[3,2-b]indole-2,10- diyl)bis(methanylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile (L8-BO). The stepwise introduction of 10-cyclohexyldecyl side chains decreases the optical bandgap, deepens the energy level, and enables the acceptor molecules to pack closely in a regular manner. Crystallographic analysis demonstrates that the 10-cyclohexyldecyl chain endows the acceptor with a more planar skeleton and enforces more compact 3D network packing, resulting in an active layer with higher domain purity. Moreover, the 10-cyclohexyldecyl chain affects the donor/acceptor interfacial energetics and accelerates exciton dissociation, enabling a power conversion efficiency (PCE) of >18% in the 2,2'-((2Z,2'Z)-((12,13-bis(2-ethylhexyl)-3,9-diundecyl12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2″,3″':4',5']thieno[2',3':4,5]pyrrolo[3,2-g]thieno[2',3':4,5]thieno[3,2-b]indole-2,10-diyl)bis(methanylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile (Y6) (PM6):A-C10ch-based organic solar cells (OSCs). Importantly, the incorporation of Y-C10ch as the third component of the PM6:L8-BO blend results in a higher PCE of 19.1%. The superior molecular packing behavior of the 10-cyclohexyldecyl side chain is highlighted here for the fabrication of high-performance OSCs.
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Affiliation(s)
- Cong Xiao
- Key Laboratory of Optoelectronic Chemical Materials and Devices (Ministry of Education)School of Optoelectronic Materials and TechnologyJianghan UniversityWuhan430056China
| | - Xunchang Wang
- Key Laboratory of Optoelectronic Chemical Materials and Devices (Ministry of Education)School of Optoelectronic Materials and TechnologyJianghan UniversityWuhan430056China
- State Key Laboratory of Fine BlastingJianghan UniversityWuhan430056China
| | - Tian Zhong
- Key Laboratory of Optoelectronic Chemical Materials and Devices (Ministry of Education)School of Optoelectronic Materials and TechnologyJianghan UniversityWuhan430056China
| | - Ruixue Zhou
- Key Laboratory of Optoelectronic Chemical Materials and Devices (Ministry of Education)School of Optoelectronic Materials and TechnologyJianghan UniversityWuhan430056China
| | - Xufan Zheng
- Key Laboratory of Optoelectronic Chemical Materials and Devices (Ministry of Education)School of Optoelectronic Materials and TechnologyJianghan UniversityWuhan430056China
| | - Yirui Liu
- Key Laboratory of Optoelectronic Chemical Materials and Devices (Ministry of Education)School of Optoelectronic Materials and TechnologyJianghan UniversityWuhan430056China
| | - Tianyu Hu
- Key Laboratory of Optoelectronic Chemical Materials and Devices (Ministry of Education)School of Optoelectronic Materials and TechnologyJianghan UniversityWuhan430056China
| | - Yixuan Luo
- Hubei Engineering Technology Research Center of Optoelectronic and New Energy MaterialsWuhan Institute of TechnologyWuhan430205China
| | - Fengbo Sun
- Hubei Engineering Technology Research Center of Optoelectronic and New Energy MaterialsWuhan Institute of TechnologyWuhan430205China
| | - Biao Xiao
- Key Laboratory of Optoelectronic Chemical Materials and Devices (Ministry of Education)School of Optoelectronic Materials and TechnologyJianghan UniversityWuhan430056China
| | - Zhitian Liu
- Hubei Engineering Technology Research Center of Optoelectronic and New Energy MaterialsWuhan Institute of TechnologyWuhan430205China
| | - Chunming Yang
- Shanghai Synchrotron Radiation FacilityShanghai Advanced Research InstituteChinese Academy of SciencesShanghai201204China
| | - Renqiang Yang
- Key Laboratory of Optoelectronic Chemical Materials and Devices (Ministry of Education)School of Optoelectronic Materials and TechnologyJianghan UniversityWuhan430056China
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19
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Guo Y, Zhu L, Duan R, Han G, Yi Y. Molecular Design of A-D-A Electron Acceptors Towards Low Energy Loss for Organic Solar Cells. Chemistry 2022; 29:e202203356. [PMID: 36504417 DOI: 10.1002/chem.202203356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 12/10/2022] [Accepted: 12/12/2022] [Indexed: 12/15/2022]
Abstract
Low energy loss is a prerequisite for organic solar cells to achieve high photovoltaic efficiency. Electron-vibration coupling (i. e., intramolecular reorganization energy) plays a crucial role in the photoelectrical conversion and energy loss processes. In this Concept article, we summarize our recent theoretical advances on revealing the energy loss mechanisms at the molecular level of A-D-A electron acceptors. We underline the importance of electron-vibration couplings on reducing the energy loss and describe the effective molecular design strategies towards low energy loss through decreasing the electron-vibration couplings.
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Affiliation(s)
- Yuan Guo
- Faculty of Light Industry, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353, P. R. China.,Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Organic Solids Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Lingyun Zhu
- Chinese Academy of Sciences (CAS) Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
| | - Ruihong Duan
- School of Science, Xuchang University Xuchang, Henan, 461000, P. R. China
| | - Guangchao Han
- Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Organic Solids Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Yuanping Yi
- Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Organic Solids Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.,University of Chinese Academy Sciences, Beijing, 100049, P. R. China
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20
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Zhang J, Guan J, Zhang Y, Qin S, Zhu Q, Kong X, Ma Q, Li X, Meng L, Yi Y, Zheng J, Li Y. Direct Observation of Increased Free Carrier Generation Owing to Reduced Exciton Binding Energies in Polymerized Small-Molecule Acceptors. J Phys Chem Lett 2022; 13:8816-8824. [PMID: 36107413 DOI: 10.1021/acs.jpclett.2c02337] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Energy loss caused by exciton binding energy (Eb) has become a key factor that restricts further advancement of organic solar cells (OSCs). Herein, we used transient mid-IR spectroscopy to study direct photogeneration of free charge carriers in small-molecule acceptors (SMAs) Y6 and IDIC as well as polymerized SMAs (PSMAs) PYFT and PZ1. We found that free carrier concentration is higher in PSMAs than in their corresponding SMAs, indicating reduced exciton Eb, which is then confirmed by ultraviolet photoelectron spectroscopy, low-energy inverse photoemission spectroscopy, and film absorption spectra measurements. The measured Eb values of PYFT and PZ1 are 0.24 and 0.37 eV, respectively, smaller than those of Y6 (0.32 eV) and IDIC (0.47 eV). This work not only provides a method to directly monitor the photogenerated free carriers in OSC materials but also demonstrates that polymerization is an effective strategy to reduce the Eb, which is crucial to decrease the energy losses in high-performance OSCs.
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Affiliation(s)
- Jinyuan Zhang
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Jianxin Guan
- College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Yaogang Zhang
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- School of Chemical Science, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shucheng Qin
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- School of Chemical Science, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qingye Zhu
- College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Xiaolei Kong
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- School of Chemical Science, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qing Ma
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- School of Chemical Science, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaojun Li
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Lei Meng
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- School of Chemical Science, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yuanping Yi
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- School of Chemical Science, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Junrong Zheng
- College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Yongfang Li
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- School of Chemical Science, University of Chinese Academy of Sciences, Beijing 100049, China
- Laboratory of Advanced Optoelectronic Materials, Suzhou Key Laboratory of Novel Semiconductor Materials and Devices, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, Jiangsu, China
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21
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Over 18% binary organic solar cells enabled by isomerization of non-fullerene acceptors with alkylthiophene side chains. Sci China Chem 2022. [DOI: 10.1007/s11426-022-1290-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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22
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Zhang G, Lin FR, Qi F, Heumüller T, Distler A, Egelhaaf HJ, Li N, Chow PCY, Brabec CJ, Jen AKY, Yip HL. Renewed Prospects for Organic Photovoltaics. Chem Rev 2022; 122:14180-14274. [PMID: 35929847 DOI: 10.1021/acs.chemrev.1c00955] [Citation(s) in RCA: 149] [Impact Index Per Article: 74.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Organic photovoltaics (OPVs) have progressed steadily through three stages of photoactive materials development: (i) use of poly(3-hexylthiophene) and fullerene-based acceptors (FAs) for optimizing bulk heterojunctions; (ii) development of new donors to better match with FAs; (iii) development of non-fullerene acceptors (NFAs). The development and application of NFAs with an A-D-A configuration (where A = acceptor and D = donor) has enabled devices to have efficient charge generation and small energy losses (Eloss < 0.6 eV), resulting in substantially higher power conversion efficiencies (PCEs) than FA-based devices. The discovery of Y6-type acceptors (Y6 = 2,2'-((2Z,2'Z)-((12,13-bis(2-ethylhexyl)-3,9-diundecyl-12,13-dihydro-[1,2,5]-thiadiazolo[3,4-e]-thieno[2″,3″:4',5']thieno-[2',3':4,5]pyrrolo-[3,2-g]thieno-[2',3':4,5]thieno-[3,2-b]indole-2,10-diyl)bis(methanylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile) with an A-DA' D-A configuration has further propelled the PCEs to go beyond 15% due to smaller Eloss values (∼0.5 eV) and higher external quantum efficiencies. Subsequently, the PCEs of Y6-series single-junction devices have increased to >19% and may soon approach 20%. This review provides an update of recent progress of OPV in the following aspects: developments of novel NFAs and donors, understanding of the structure-property relationships and underlying mechanisms of state-of-the-art OPVs, and tasks underpinning the commercialization of OPVs, such as device stability, module development, potential applications, and high-throughput manufacturing. Finally, an outlook and prospects section summarizes the remaining challenges for the further development of OPV technology.
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Affiliation(s)
- Guichuan Zhang
- State Key Laboratory of Luminescent Materials and Devices, Institute of Polymer Optoelectronic Materials and Devices, School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China.,School of Semiconductor Science and Technology, South China Normal University, Foshan 528225, China
| | - Francis R Lin
- Department of Materials Science and Engineering, City University of Hong Kong, Kowloon 999077, Hong Kong, China.,Department of Chemistry, City University of Hong Kong, Kowloon 999077, Hong Kong, China
| | - Feng Qi
- Department of Materials Science and Engineering, City University of Hong Kong, Kowloon 999077, Hong Kong, China.,Department of Chemistry, City University of Hong Kong, Kowloon 999077, Hong Kong, China
| | - Thomas Heumüller
- Institute of Materials for Electronics and Energy Technology (i-MEET), Department of Materials Science and Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, Martensstrasse 7, 91058 Erlangen, Germany.,Helmholtz Institute Erlangen-Nürnberg (HI ERN), Immerwahrstrasse 2, 91058 Erlangen, Germany
| | - Andreas Distler
- Institute of Materials for Electronics and Energy Technology (i-MEET), Department of Materials Science and Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, Martensstrasse 7, 91058 Erlangen, Germany
| | - Hans-Joachim Egelhaaf
- Institute of Materials for Electronics and Energy Technology (i-MEET), Department of Materials Science and Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, Martensstrasse 7, 91058 Erlangen, Germany.,Helmholtz Institute Erlangen-Nürnberg (HI ERN), Immerwahrstrasse 2, 91058 Erlangen, Germany
| | - Ning Li
- State Key Laboratory of Luminescent Materials and Devices, Institute of Polymer Optoelectronic Materials and Devices, School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China
| | - Philip C Y Chow
- Department of Mechanical Engineering, The University of Hong Kong, Pokfulam 999077, Hong Kong, China
| | - Christoph J Brabec
- Institute of Materials for Electronics and Energy Technology (i-MEET), Department of Materials Science and Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, Martensstrasse 7, 91058 Erlangen, Germany.,Helmholtz Institute Erlangen-Nürnberg (HI ERN), Immerwahrstrasse 2, 91058 Erlangen, Germany
| | - Alex K-Y Jen
- Department of Materials Science and Engineering, City University of Hong Kong, Kowloon 999077, Hong Kong, China.,Department of Chemistry, City University of Hong Kong, Kowloon 999077, Hong Kong, China.,School of Energy and Environment, City University of Hong Kong, Kowloon 999077, Hong Kong, China.,Hong Kong Institute for Clean Energy, City University of Hong Kong, Kowloon 999077, Hong Kong, China
| | - Hin-Lap Yip
- State Key Laboratory of Luminescent Materials and Devices, Institute of Polymer Optoelectronic Materials and Devices, School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China.,Department of Materials Science and Engineering, City University of Hong Kong, Kowloon 999077, Hong Kong, China.,School of Energy and Environment, City University of Hong Kong, Kowloon 999077, Hong Kong, China.,Hong Kong Institute for Clean Energy, City University of Hong Kong, Kowloon 999077, Hong Kong, China
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23
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Guo Y, Han G, Yi Y. The Intrinsic Role of the Fusion Mode and Electron-Deficient Core in Fused-Ring Electron Acceptors for Organic Photovoltaics. Angew Chem Int Ed Engl 2022; 61:e202205975. [PMID: 35604363 DOI: 10.1002/anie.202205975] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Indexed: 11/08/2022]
Abstract
The A-DA'D-A fused-ring electron acceptors with an angular fusion mode and electron-deficient core has significantly boosted organic photovoltaic efficiency. Here, the intrinsic role of the peculiar structure is revealed by comparing representative A-DA'D-A acceptor Y6 with its A-D-A counterparts having different fusion modes. Owing to the more delocalized HOMO and deeper LUMO level, Y6 exhibits stronger and red-shifted absorption relative to the linear and angular fused A-D-A acceptors, respectively. Moreover, the change from linear to angular fusion substantially reduces the electron-vibration couplings, which is responsible for the faster exciton diffusion, exciton dissociation, and electron transport for Y6 than the linear fused A-D-A acceptor. Notably, the electron-vibration coupling for exciton dissociation is further decreased by introducing the electron-deficient core, thus contributing to the efficient charge generation under low driving forces in the Y6-based devices.
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Affiliation(s)
- Yuan Guo
- Faculty of Light Industry, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353, China.,Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Guangchao Han
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Yuanping Yi
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.,University of Chinese Academy Sciences, Beijing, 100049, China
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24
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Pavliuk MV, Lorenzi M, Morado DR, Gedda L, Wrede S, Mejias SH, Liu A, Senger M, Glover S, Edwards K, Berggren G, Tian H. Polymer Dots as Photoactive Membrane Vesicles for [FeFe]-Hydrogenase Self-Assembly and Solar-Driven Hydrogen Evolution. J Am Chem Soc 2022; 144:13600-13611. [PMID: 35863067 PMCID: PMC9354254 DOI: 10.1021/jacs.2c03882] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
A semiartificial photosynthesis approach that utilizes enzymes for solar fuel production relies on efficient photosensitizers that should match the enzyme activity and enable long-term stability. Polymer dots (Pdots) are biocompatible photosensitizers that are stable at pH 7 and have a readily modifiable surface morphology. Therefore, Pdots can be considered potential photosensitizers to drive such enzyme-based systems for solar fuel formation. This work introduces and unveils in detail the interaction within the biohybrid assembly composed of binary Pdots and the HydA1 [FeFe]-hydrogenase from Chlamydomonas reinhardtii. The direct attachment of hydrogenase on the surface of toroid-shaped Pdots was confirmed by agarose gel electrophoresis, cryogenic transmission electron microscopy (Cryo-TEM), and cryogenic electron tomography (Cryo-ET). Ultrafast transient spectroscopic techniques were used to characterize photoinduced excitation and dissociation into charges within Pdots. The study reveals that implementation of a donor-acceptor architecture for heterojunction Pdots leads to efficient subpicosecond charge separation and thus enhances hydrogen evolution (88 460 μmolH2·gH2ase-1·h-1). Adsorption of [FeFe]-hydrogenase onto Pdots resulted in a stable biohybrid assembly, where hydrogen production persisted for days, reaching a TON of 37 500 ± 1290 in the presence of a redox mediator. This work represents an example of a homogeneous biohybrid system combining polymer nanoparticles and an enzyme. Detailed spectroscopic studies provide a mechanistic understanding of light harvesting, charge separation, and transport studied, which is essential for building semiartificial photosynthetic systems with efficiencies beyond natural and artificial systems.
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Affiliation(s)
- Mariia V Pavliuk
- Department of Chemistry─Ångström Laboratory, Physical Chemistry, Uppsala University, 751 20 Uppsala, Sweden
| | - Marco Lorenzi
- Department of Chemistry─Ångström Laboratory, Molecular Biomimetics, Uppsala University, 751 20 Uppsala, Sweden
| | - Dustin R Morado
- Department of Biochemistry and Biophysics, Science for Life Laboratory, Stockholm University, 171 65 Solna, Sweden
| | - Lars Gedda
- Department of Chemistry─Ångström Laboratory, Physical Chemistry, Uppsala University, 751 20 Uppsala, Sweden
| | - Sina Wrede
- Department of Chemistry─Ångström Laboratory, Physical Chemistry, Uppsala University, 751 20 Uppsala, Sweden
| | - Sara H Mejias
- Department of Chemistry─Ångström Laboratory, Physical Chemistry, Uppsala University, 751 20 Uppsala, Sweden
| | - Aijie Liu
- Department of Chemistry─Ångström Laboratory, Physical Chemistry, Uppsala University, 751 20 Uppsala, Sweden
| | - Moritz Senger
- Department of Chemistry─Ångström Laboratory, Physical Chemistry, Uppsala University, 751 20 Uppsala, Sweden
| | - Starla Glover
- Department of Chemistry─Ångström Laboratory, Physical Chemistry, Uppsala University, 751 20 Uppsala, Sweden
| | - Katarina Edwards
- Department of Chemistry─Ångström Laboratory, Physical Chemistry, Uppsala University, 751 20 Uppsala, Sweden
| | - Gustav Berggren
- Department of Chemistry─Ångström Laboratory, Molecular Biomimetics, Uppsala University, 751 20 Uppsala, Sweden
| | - Haining Tian
- Department of Chemistry─Ångström Laboratory, Physical Chemistry, Uppsala University, 751 20 Uppsala, Sweden
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25
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Guo Y, Han G, Yi Y. The Intrinsic Role of the Fusion Mode and Electron‐Deficient Core in Fused‐Ring Electron Acceptors for Organic Photovoltaics. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202205975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Yuan Guo
- Faculty of Light Industry Qilu University of Technology (Shandong Academy of Sciences) Jinan 250353 China
- Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Organic Solids Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China
| | - Guangchao Han
- Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Organic Solids Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China
| | - Yuanping Yi
- Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Organic Solids Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China
- University of Chinese Academy Sciences Beijing 100049 China
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26
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Shivhare R, Moore GJ, Hofacker A, Hutsch S, Zhong Y, Hambsch M, Erdmann T, Kiriy A, Mannsfeld SCB, Ortmann F, Banerji N. Short Excited-State Lifetimes Mediate Charge-Recombination Losses in Organic Solar Cell Blends with Low Charge-Transfer Driving Force. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2101784. [PMID: 34396598 DOI: 10.1002/adma.202101784] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 06/18/2021] [Indexed: 06/13/2023]
Abstract
A blend of a low-optical-gap diketopyrrolopyrrole polymer and a fullerene derivative, with near-zero driving force for electron transfer, is investigated. Using femtosecond transient absorption and electroabsorption spectroscopy, the charge transfer (CT) and recombination dynamics as well as the early-time transport are quantified. Electron transfer is ultrafast, consistent with a Marcus-Levich-Jortner description. However, significant charge recombination and unusually short excited (S1 ) and CT state lifetimes (≈14 ps) are observed. At low S1 -CT offset, a short S1 lifetime mediates charge recombination because: i) back-transfer from the CT to the S1 state followed by S1 recombination occurs and ii) additional S1 -CT hybridization decreases the CT lifetime. Both effects are confirmed by density functional theory calculations. In addition, relatively slow (tens of picoseconds) dissociation of charges from the CT state is observed, due to low local charge mobility. Simulations using a four-state kinetic model entailing the effects of energetic disorder reveal that the free charge yield can be increased from the observed 12% to 60% by increasing the S1 and CT lifetimes to 150 ps. Alternatively, decreasing the interfacial CT state disorder while increasing bulk disorder of free charges enhances the yield to 65% in spite of the short lifetimes.
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Affiliation(s)
- Rishi Shivhare
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, Bern, CH-3012, Switzerland
| | - Gareth John Moore
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, Bern, CH-3012, Switzerland
| | - Andreas Hofacker
- Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Institute for Applied Physics, Technical University of Dresden, Nöthnitzerstrasse 61, D-01187, Dresden, Germany
| | - Sebastian Hutsch
- Department of Chemistry, Technical University of Munich, Lichtenbergstrasse 4, D-85748, Garching b. München, Germany
- Center for Advancing Electronics Dresden, Technical University of Dresden, Helmholtzstrasse 18, D-01069, Dresden, Germany
| | - Yufei Zhong
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, Bern, CH-3012, Switzerland
| | - Mike Hambsch
- Center for Advancing Electronics Dresden, Technical University of Dresden, Helmholtzstrasse 18, D-01069, Dresden, Germany
| | - Tim Erdmann
- IBM Almaden Research Center, 650 Harry Road, San Jose, CA, 95120, USA
| | - Anton Kiriy
- Leibniz Institute of Polymer Research Dresden, Hohestrasse 6, D-01069, Dresden, Germany
| | - Stefan C B Mannsfeld
- Center for Advancing Electronics Dresden, Technical University of Dresden, Helmholtzstrasse 18, D-01069, Dresden, Germany
| | - Frank Ortmann
- Department of Chemistry, Technical University of Munich, Lichtenbergstrasse 4, D-85748, Garching b. München, Germany
- Center for Advancing Electronics Dresden, Technical University of Dresden, Helmholtzstrasse 18, D-01069, Dresden, Germany
| | - Natalie Banerji
- Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, Bern, CH-3012, Switzerland
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27
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Asymmetric electron acceptor enables highly luminescent organic solar cells with certified efficiency over 18. Nat Commun 2022; 13:2598. [PMID: 35545620 PMCID: PMC9095617 DOI: 10.1038/s41467-022-30225-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 04/21/2022] [Indexed: 11/09/2022] Open
Abstract
Enhancing the luminescence property without sacrificing the charge collection is one key to high-performance organic solar cells (OSCs), while limited by the severe non-radiative charge recombination. Here, we demonstrate efficient OSCs with high luminescence via the design and synthesis of an asymmetric non-fullerene acceptor, BO-5Cl. Blending BO-5Cl with the PM6 donor leads to a record-high electroluminescence external quantum efficiency of 0.1%, which results in a low non-radiative voltage loss of 0.178 eV and a power conversion efficiency (PCE) over 15%. Importantly, incorporating BO-5Cl as the third component into a widely-studied donor:acceptor (D:A) blend, PM6:BO-4Cl, allows device displaying a high certified PCE of 18.2%. Our joint experimental and theoretical studies unveil that more diverse D:A interfacial conformations formed by asymmetric acceptor induce optimized blend interfacial energetics, which contributes to the improved device performance via balancing charge generation and recombination. High-performance organic solar cells call for novel designs of acceptor molecules. Here, He et al. design and synthesize a non-fullerene acceptor with an asymmetric structure for diverse donor:acceptor interfacial conformations and report a certificated power conversion efficiency of 18.2%.
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Zeiske S, Sandberg OJ, Kurpiers J, Shoaee S, Meredith P, Armin A. Probing Charge Generation Efficiency in Thin-Film Solar Cells by Integral-Mode Transient Charge Extraction. ACS PHOTONICS 2022; 9:1188-1195. [PMID: 35571262 PMCID: PMC9097587 DOI: 10.1021/acsphotonics.1c01532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Indexed: 06/15/2023]
Abstract
The photogeneration of free charges in light-harvesting devices is a multistep process, which can be challenging to probe due to the complexity of contributing energetic states and the competitive character of different driving mechanisms. In this contribution, we advance a technique, integral-mode transient charge extraction (ITCE), to probe these processes in thin-film solar cells. ITCE combines capacitance measurements with the integral-mode time-of-flight method in the low intensity regime of sandwich-type thin-film devices and allows for the sensitive determination of photogenerated charge-carrier densities. We verify the theoretical framework of our method by drift-diffusion simulations and demonstrate the applicability of ITCE to organic and perovskite semiconductor-based thin-film solar cells. Furthermore, we examine the field dependence of charge generation efficiency and find our ITCE results to be in excellent agreement with those obtained via time-delayed collection field measurements conducted on the same devices.
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Affiliation(s)
- Stefan Zeiske
- Sustainable
Advanced Materials (Sêr-SAM), Department of Physics, Swansea University, Singleton Park, Swansea SA2 8PP, Wales, United Kingdom
| | - Oskar J. Sandberg
- Sustainable
Advanced Materials (Sêr-SAM), Department of Physics, Swansea University, Singleton Park, Swansea SA2 8PP, Wales, United Kingdom
| | - Jona Kurpiers
- Disordered Semiconductor Optoelectronics,
Institute
of Physics and Astronomy, University Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam-Golm, Germany
| | - Safa Shoaee
- Disordered Semiconductor Optoelectronics,
Institute
of Physics and Astronomy, University Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam-Golm, Germany
| | - Paul Meredith
- Sustainable
Advanced Materials (Sêr-SAM), Department of Physics, Swansea University, Singleton Park, Swansea SA2 8PP, Wales, United Kingdom
| | - Ardalan Armin
- Sustainable
Advanced Materials (Sêr-SAM), Department of Physics, Swansea University, Singleton Park, Swansea SA2 8PP, Wales, United Kingdom
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29
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Jacoutot P, Scaccabarozzi AD, Zhang T, Qiao Z, Aniés F, Neophytou M, Bristow H, Kumar R, Moser M, Nega AD, Schiza A, Dimitrakopoulou-Strauss A, Gregoriou VG, Anthopoulos TD, Heeney M, McCulloch I, Bakulin AA, Chochos CL, Gasparini N. Infrared Organic Photodetectors Employing Ultralow Bandgap Polymer and Non-Fullerene Acceptors for Biometric Monitoring. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2200580. [PMID: 35246948 DOI: 10.1002/smll.202200580] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 02/14/2022] [Indexed: 06/14/2023]
Abstract
Recent efforts in the field of organic photodetectors (OPD) have been focused on extending broadband detection into the near-infrared (NIR) region. Here, two blends of an ultralow bandgap push-pull polymer TQ-T combined with state-of-the-art non-fullerene acceptors, IEICO-4F and Y6, are compared to obtain OPDs for sensing in the NIR beyond 1100 nm, which is the cut off for benchmark Si photodiodes. It is observed that the TQ-T:IEICO-4F device has a superior IR responsivity (0.03 AW-1 at 1200 nm and -2 V bias) and can detect infrared light up to 1800 nm, while the TQ-T:Y6 blend shows a lower responsivity of 0.01 AW-1 . Device physics analyses are tied with spectroscopic and morphological studies to link the superior performance of TQ-T:IEICO-4F OPD to its faster charge separation as well as more favorable donor-acceptor domains mixing. In the polymer blend with Y6, the formation of large agglomerates that exceed the exciton diffusion length, which leads to high charge recombination, is observed. An application of these devices as biometric sensors for real-time heart rate monitoring via photoplethysmography, utilizing infrared light, is demonstrated.
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Affiliation(s)
- Polina Jacoutot
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, London, W12 0BZ, UK
| | - Alberto D Scaccabarozzi
- King Abdullah University of Science and Technology (KAUST), KAUST Solar Center (KSC), Thuwal, 23955, Saudi Arabia
| | - Tianyi Zhang
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, London, W12 0BZ, UK
| | - Zhuoran Qiao
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, London, W12 0BZ, UK
| | - Filip Aniés
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, London, W12 0BZ, UK
| | - Marios Neophytou
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, OX1 3TA, UK
| | - Helen Bristow
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, OX1 3TA, UK
| | - Rhea Kumar
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, London, W12 0BZ, UK
| | - Maximilian Moser
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, OX1 3TA, UK
| | - Alkmini D Nega
- Clinical Cooperation Unit Nuclear Medicine, German Cancer Research Center, 69120, Heidelberg, Germany
| | - Andriana Schiza
- Institute of Chemical Biology, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, Athens, 11635, Greece
| | | | - Vasilis G Gregoriou
- Advent Technologies SA, Stadiou Street, Platani, Rio, Patras, 26504, Greece
- National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, Athens, 11635, Greece
| | - Thomas D Anthopoulos
- King Abdullah University of Science and Technology (KAUST), KAUST Solar Center (KSC), Thuwal, 23955, Saudi Arabia
| | - Martin Heeney
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, London, W12 0BZ, UK
| | - Iain McCulloch
- King Abdullah University of Science and Technology (KAUST), KAUST Solar Center (KSC), Thuwal, 23955, Saudi Arabia
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, OX1 3TA, UK
| | - Artem A Bakulin
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, London, W12 0BZ, UK
| | - Christos L Chochos
- Institute of Chemical Biology, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, Athens, 11635, Greece
- Advent Technologies SA, Stadiou Street, Platani, Rio, Patras, 26504, Greece
| | - Nicola Gasparini
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, London, W12 0BZ, UK
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30
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Han G, Yi Y. Molecular Insight into Efficient Charge Generation in Low-Driving-Force Nonfullerene Organic Solar Cells. Acc Chem Res 2022; 55:869-877. [PMID: 35230078 DOI: 10.1021/acs.accounts.1c00742] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
ConspectusFor organic solar cells (OSCs), charge generation at the donor/acceptor interfaces is regarded as a two-step process: driven by the interfacial energy offsets, the excitons produced by light absorption are first dissociated into the charge-transfer (CT) states, and then the CT states are further separated into free charge carriers of holes and electrons by overcoming their Coulomb attraction. Meanwhile, the CT states can recombine through radiative and nonradiative decay. Owing to the emergence of narrow-band-gap A-D-A small-molecule acceptors, nonfullerene (NF) OSCs have developed rapidly in recent years and the power conversion efficiencies (PCEs) surpass 18% now. The great achievement can be attributed to the high-yield charge generation under low exciton dissociation (ED) driving forces, which ensures both high photocurrent and small voltage loss. However, it is traditionally believed that a considerable driving force (e.g., at least 0.3 eV in fullerene-based OSCs) is essential to provide excess energy for the CT states to achieve efficient charge separation (CS). Therefore, a fundamental question open to the community is how the excitons split into free charge carriers so efficiently under low driving forces in the state-of-the-art NF OSCs.In this Account, we summarize our recent theoretical advances on the charge generation mechanisms in the low-driving-force NF OSCs. First, the A-D-A acceptors are found to dock with the D-A copolymer or A-D-A small-molecule donors mainly via local π-π interaction between their electron-withdrawing units, and such interfacial geometries can provide sufficient electronic couplings, thus ensuring fast ED. Second, the polarization energies of holes and electrons are enhanced during CS, which is beneficial to reduce the CS energy barrier and even leads to barrierless CS in the OSCs based on fluorinated A-D-A acceptors. Moreover, the exciton binding energies (Eb) are substantially decreased by the strong polarization of charge carriers for the A-D-A acceptors; especially for the Y6 system with three-dimensional molecular packing structures, the remarkable small Eb can enable direct photogeneration of free charge carriers. Accordingly, the excess energy becomes unnecessary for CS in the state-of-the-art NF OSCs. Third, to simultaneously decrease the driving force and suppress charge recombination via the triplet channel, it is imperative to reduce the singlet-triplet energy difference (ΔEST) of the narrow-band-gap A-D-A acceptors. Importantly, the intermolecular end-group π-π stacking is demonstrated to effectively decrease the ΔEST while keeping strong light absorption. Finally, hybridization of the CT states with local excitation can be induced by small interfacial energy offset. Such hybridization will result in direct population of thermalized CT states upon light absorption and a significant increase of luminescence quantum efficiency, which is beneficial to concurrently promote CS and reduce nonradiative voltage loss. We hope this Account contributes to the molecular understanding of the mechanisms of efficient charge generation with low driving forces and would be helpful for further improving the performance of organic photovoltaics in the future.
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Affiliation(s)
- Guangchao Han
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Yuanping Yi
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- School of Chemical Sciences, University of Chinese Academy Sciences, Beijing 100049, China
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31
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Souza JPA, Benatto L, Candiotto G, Roman LS, Koehler M. Binding Energy of Triplet Excitons in Nonfullerene Acceptors: The Effects of Fluorination and Chlorination. J Phys Chem A 2022; 126:1393-1402. [PMID: 35192353 DOI: 10.1021/acs.jpca.1c10607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
One strategy to improve the photovoltaic properties of nonfullerene acceptors (NFAs), employed in state-of-art organic solar cells, is the rational fluorination or chlorination of these molecules. Although this modification improves important acceptor properties, little is known about the effects on the triplet states. Here, we combine the polarizable continuum model with an optimally tuned range-separated hybrid functional to investigate this issue. We find that fluorination or chlorination of NFAs decreases the degree of the highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) overlap along these molecules. Consequently, the energy gap between T1 and S1 states, ΔEST = ES1 - ET1, also decreases. This effect reduces the binding energy of triplet excitons, which favors their dissociation into free charges. Furthermore, the reduction of ΔEST can contribute to mitigating the losses produced by the nonradiative deactivation of the T1 excitons. Interestingly, although Cl has a lower electronegativity than F, chlorination is more effective to reduce ΔEST. Since the chlorination of NFAs is easier than fluorination, Cl substitution can be a useful approach to enhance solar energy harvesting using triplet excitons.
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Affiliation(s)
- J P A Souza
- Department of Physics, Federal University of Paraná, 81531-980 Curitiba, PR, Brazil
| | - L Benatto
- Department of Physics, Federal University of Paraná, 81531-980 Curitiba, PR, Brazil
| | - G Candiotto
- Institute of Chemistry, Federal University of Rio de Janeiro, 21941-909 Rio de Janeiro, RJ, Brazil
| | - L S Roman
- Department of Physics, Federal University of Paraná, 81531-980 Curitiba, PR, Brazil
| | - M Koehler
- Department of Physics, Federal University of Paraná, 81531-980 Curitiba, PR, Brazil
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32
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Zhong W, Zhang M, Freychet G, Su GM, Ying L, Huang F, Cao Y, Zhang Y, Wang C, Liu F. Decoupling Complex Multi-Length-Scale Morphology in Non-Fullerene Photovoltaics with Nitrogen K-Edge Resonant Soft X-ray Scattering. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2107316. [PMID: 34750871 DOI: 10.1002/adma.202107316] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 10/29/2021] [Indexed: 06/13/2023]
Abstract
Complex morphology in organic photovoltaics (OPVs) and other functional soft materials commonly dictates performance. Such complexity in OPVs originates from the mesoscale kinetically trapped non-equilibrium state, which governs device charge generation and transport. Resonant soft X-ray scattering (RSoXS) has been revolutionary in the exploration of OPV morphology in the past decade due to its chemical and orientation sensitivity. However, for non-fullerene OPVs, RSoXS analysis near the carbon K-edge is challenging, due to the chemical similarity of the materials used in active layers. An innovative approach is provided by nitrogen K-edge RSoXS (NK-RSoXS), utilizing the spatial and orientational contrasts from the cyano groups in the acceptor materials, which allows for determination of phase separation. NK-RSoXS clearly visualizes the combined feature sizes in PM6:Y6 blends from crystallization and liquid-liquid demixing, while PM6:Y6:Y6-BO ternary blends with reduced phase-separation size and enhanced material crystallization can lead to current amplification in devices. Nitrogen is common in organic semiconductors and other soft materials, and the strong and directional N 1s → π* resonances make NK-RSoXS a powerful tool to uncover the mesoscale complexity and open opportunities to understand heterogeneous systems.
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Affiliation(s)
- Wenkai Zhong
- Frontiers Science Center for Transformative Molecules, Center of Hydrogen Science, and School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Ming Zhang
- Frontiers Science Center for Transformative Molecules, Center of Hydrogen Science, and School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | | | - Gregory M Su
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Lei Ying
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, China
| | - Fei Huang
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, China
| | - Yong Cao
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, China
| | - Yongming Zhang
- Frontiers Science Center for Transformative Molecules, Center of Hydrogen Science, and School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Cheng Wang
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Feng Liu
- Frontiers Science Center for Transformative Molecules, Center of Hydrogen Science, and School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
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33
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Wang Y, Kublitski J, Xing S, Dollinger F, Spoltore D, Benduhn J, Leo K. Narrowband organic photodetectors - towards miniaturized, spectroscopic sensing. MATERIALS HORIZONS 2022; 9:220-251. [PMID: 34704585 DOI: 10.1039/d1mh01215k] [Citation(s) in RCA: 41] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Omnipresent quality monitoring in food products, blood-oxygen measurement in lightweight conformal wrist bands, or data-driven automated industrial production: Innovation in many fields is being empowered by sensor technology. Specifically, organic photodetectors (OPDs) promise great advances due to their beneficial properties and low-cost production. Recent research has led to rapid improvement in all performance parameters of OPDs, which are now on-par or better than their inorganic counterparts, such as silicon or indium gallium arsenide photodetectors, in several aspects. In particular, it is possible to directly design OPDs for specific wavelengths. This makes expensive and bulky optical filters obsolete and allows for miniature detector devices. In this review, recent progress of such narrowband OPDs is systematically summarized covering all aspects from narrow-photo-absorbing materials to device architecture engineering. The recent challenges for narrowband OPDs, like achieving high responsivity, low dark current, high response speed, and good dynamic range are carefully addressed. Finally, application demonstrations covering broadband and narrowband OPDs are discussed. Importantly, several exciting research perspectives, which will stimulate further research on organic-semiconductor-based photodetectors, are pointed out at the very end of this review.
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Affiliation(s)
- Yazhong Wang
- Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Institute for Applied Physics, Technische Universität Dresden, Nöthnitzer Str. 61, 01187 Dresden, Germany.
| | - Jonas Kublitski
- Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Institute for Applied Physics, Technische Universität Dresden, Nöthnitzer Str. 61, 01187 Dresden, Germany.
| | - Shen Xing
- Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Institute for Applied Physics, Technische Universität Dresden, Nöthnitzer Str. 61, 01187 Dresden, Germany.
| | - Felix Dollinger
- Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Institute for Applied Physics, Technische Universität Dresden, Nöthnitzer Str. 61, 01187 Dresden, Germany.
| | - Donato Spoltore
- Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Institute for Applied Physics, Technische Universität Dresden, Nöthnitzer Str. 61, 01187 Dresden, Germany.
| | - Johannes Benduhn
- Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Institute for Applied Physics, Technische Universität Dresden, Nöthnitzer Str. 61, 01187 Dresden, Germany.
| | - Karl Leo
- Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Institute for Applied Physics, Technische Universität Dresden, Nöthnitzer Str. 61, 01187 Dresden, Germany.
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34
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Carr JM, Allen TG, Larson BW, Davydenko IG, Dasari RR, Barlow S, Marder SR, Reid OG, Rumbles G. Short and long-range electron transfer compete to determine free-charge yield in organic semiconductors. MATERIALS HORIZONS 2022; 9:312-324. [PMID: 34787147 DOI: 10.1039/d1mh01331a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Understanding how Frenkel excitons efficiently split to form free-charges in low-dielectric constant organic semiconductors has proven challenging, with many different models proposed in recent years to explain this phenomenon. Here, we present evidence that a simple model invoking a modest amount of charge delocalization, a sum over the available microstates, and the Marcus rate constant for electron transfer can explain many seemingly contradictory phenomena reported in the literature. We use an electron-accepting fullerene host matrix dilutely sensitized with a series of electron donor molecules to test this hypothesis. The donor series enables us to tune the driving force for photoinduced electron transfer over a range of 0.7 eV, mapping out normal, optimal, and inverted regimes for free-charge generation efficiency, as measured by time-resolved microwave conductivity. However, the photoluminescence of the donor is rapidly quenched as the driving force increases, with no evidence for inverted behavior, nor the linear relationship between photoluminescence quenching and charge-generation efficiency one would expect in the absence of additional competing loss pathways. This behavior is self-consistently explained by competitive formation of bound charge-transfer states and long-range or delocalized free-charge states, where both rate constants are described by the Marcus rate equation. Moreover, the model predicts a suppression of the inverted regime for high-concentration blends and efficient ultrafast free-charge generation, providing a mechanistic explanation for why Marcus-inverted-behavior is rarely observed in device studies.
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Affiliation(s)
- Joshua M Carr
- University of Colorado Boulder, Materials Science & Engineering Program, Boulder, CO, 80303, USA
| | - Taylor G Allen
- National Renewable Energy Laboratory, Chemistry and Nanoscience Center, Golden, CO, 80401, USA.
| | - Bryon W Larson
- National Renewable Energy Laboratory, Chemistry and Nanoscience Center, Golden, CO, 80401, USA.
| | - Iryna G Davydenko
- Georgia Institute of Technology, School of Chemistry and Biochemistry, Atlanta, GA, 30332, USA
| | - Raghunath R Dasari
- Georgia Institute of Technology, School of Chemistry and Biochemistry, Atlanta, GA, 30332, USA
| | - Stephen Barlow
- National Renewable Energy Laboratory, Chemistry and Nanoscience Center, Golden, CO, 80401, USA.
- Georgia Institute of Technology, School of Chemistry and Biochemistry, Atlanta, GA, 30332, USA
- University of Colorado Boulder, Renewable and Sustainable Energy Institute, Boulder, CO, 80303, USA
| | - Seth R Marder
- National Renewable Energy Laboratory, Chemistry and Nanoscience Center, Golden, CO, 80401, USA.
- Georgia Institute of Technology, School of Chemistry and Biochemistry, Atlanta, GA, 30332, USA
- University of Colorado Boulder, Renewable and Sustainable Energy Institute, Boulder, CO, 80303, USA
- University of Colorado Boulder, Department of Chemistry, Boulder, CO, 80303, USA
- University of Colorado Boulder, Department of Chemical and Biological Engineering, Boulder, CO, 80303, USA
| | - Obadiah G Reid
- National Renewable Energy Laboratory, Chemistry and Nanoscience Center, Golden, CO, 80401, USA.
- University of Colorado Boulder, Renewable and Sustainable Energy Institute, Boulder, CO, 80303, USA
| | - Garry Rumbles
- National Renewable Energy Laboratory, Chemistry and Nanoscience Center, Golden, CO, 80401, USA.
- University of Colorado Boulder, Renewable and Sustainable Energy Institute, Boulder, CO, 80303, USA
- University of Colorado Boulder, Department of Chemistry, Boulder, CO, 80303, USA
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35
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Wan P, Chen X, Liu Q, Mahadevan S, Guo M, Qiu J, Sun X, Tsang SW, Zhang M, Li Y, Chen S. Direct Observation of the Charge Transfer States from a Non-Fullerene Organic Solar Cell with a Small Driving Force. J Phys Chem Lett 2021; 12:10595-10602. [PMID: 34695357 DOI: 10.1021/acs.jpclett.1c03365] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
For organic solar cells (OSCs), the charge generation mechanism and the recombination loss are heavily linked with charge transfer states (CTS). Measuring the energy of CTS (ECT) by the most widely used technique, however, has become challenging for the non-fullerene-based OSCs with a small driving force, resulting in difficulty in the understanding of OSC physics. Herein, we present a study of the PM6:Y6 bulk heterojunction. It is demonstrated that electro-absorption can not only reveal the dipolar nature of Y6 but also resolve the morphology-dependent absorption signal of CTS in the sub-bandgap region. The device with the optimum blending weight ratio shows an ECT of 1.27 eV, which is confirmed by independent measurements. Because of the charge transfer characteristics of Y6, the charge generation at PM6:Y6 interfaces occurs efficiently under a small but non-negligible driving force of 0.14 eV, and the total recombination loss is as low as 0.43 eV.
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Affiliation(s)
- Peng Wan
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren'ai Road, Suzhou 215123, PR China
| | - Xingtong Chen
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren'ai Road, Suzhou 215123, PR China
| | - Qi Liu
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, Laboratory of Advanced Optoelectronic Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren'ai Road, Suzhou 215123, PR China
| | - Sudhi Mahadevan
- Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong SAR 999077, China
| | - Mingxuan Guo
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren'ai Road, Suzhou 215123, PR China
| | - Jinjing Qiu
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, Laboratory of Advanced Optoelectronic Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren'ai Road, Suzhou 215123, PR China
| | - Xiaojuan Sun
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren'ai Road, Suzhou 215123, PR China
| | - Sai-Wing Tsang
- Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong SAR 999077, China
| | - Maojie Zhang
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, Laboratory of Advanced Optoelectronic Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren'ai Road, Suzhou 215123, PR China
| | - Yongfang Li
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, Laboratory of Advanced Optoelectronic Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren'ai Road, Suzhou 215123, PR China
| | - Song Chen
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren'ai Road, Suzhou 215123, PR China
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36
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Dai T, Lei P, Zhang B, Zhou J, Tang A, Geng Y, Zeng Q, Zhou E. Tricyclic or Pentacyclic D Units: Design of D-π-A-Type Copolymers for High VOC Organic Photovoltaic Cells. ACS APPLIED MATERIALS & INTERFACES 2021; 13:30756-30765. [PMID: 34180228 DOI: 10.1021/acsami.1c08487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Although there are several electron-donating (D) units, only the classic benzo[1,2-b:4,5-b']dithiophenes (BDT) unit was utilized to develop D-π-A-type copolymers for high-voltage organic photovoltaic (OPV) cells. Hence, in this work, we chose two tricyclic D units, BDT and benzo[1,2-b:4,5-b']difurans (BDF), together with one pentacyclic ring, dithieno[2,3-d;2',3'-d']benzo[1,2-b;4,5-b']dithiophenes (DTBDT), to comprehensively study the effect of different D units on the optoelectronic properties and photovoltaic performance. By copolymerized with the benzo[1,2,3]triazole (BTA) electron-accepting unit, the final copolymers J52-Cl, F11, and PE52 were combined with a nonfullerene acceptor (NFA) F-BTA3 according to the "Same-A-Strategy." As we preconceived, all the three single-junction OPV cells can obtain high open-circuit voltage (VOC) over 1.10 V. Although the tricyclic D unit of BDF exhibits a slightly lower VOC of 1.12 V because of its mildly larger energy loss of 0.698 eV, its higher carrier mobilities and exciton dissociation efficiency strikingly boost the short-circuit current (JSC) and fill factor, which contribute to a comparable PCE of 10.04% with J52-Cl (10.10%). However, the DTBDT-based polymer PE52 shows the worst performance with a PCE of 6.78% and a VOC of 1.14 V, owing to the higher bimolecular recombination and disordered molecular stacking. Our results indicate that tricyclic D units should be a better choice for constructing D-π-A-type polymers for high-voltage photovoltaic materials than the pentacyclic analogues.
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Affiliation(s)
- Tingting Dai
- CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Peng Lei
- CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Bao Zhang
- CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China
- Henan Institute of Advanced Technology, Zhengzhou University, Zhengzhou 450003, China
| | - Jialing Zhou
- CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ailing Tang
- CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China
| | - Yanfang Geng
- CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China
| | - Qingdao Zeng
- CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China
| | - Erjun Zhou
- CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
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37
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Bolzonello L, Bernal-Texca F, Gerling LG, Ockova J, Collini E, Martorell J, van Hulst NF. Photocurrent-Detected 2D Electronic Spectroscopy Reveals Ultrafast Hole Transfer in Operating PM6/Y6 Organic Solar Cells. J Phys Chem Lett 2021; 12:3983-3988. [PMID: 33877838 PMCID: PMC8154857 DOI: 10.1021/acs.jpclett.1c00822] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Accepted: 04/14/2021] [Indexed: 05/05/2023]
Abstract
The performance of nonfullerene-acceptor-(NFA)-based organic solar cells is rapidly approaching the efficiency of inorganic cells. The chemical versatility of NFAs extends the light-harvesting range to the infrared, while preserving a considerably high open-circuit-voltage, crucial to achieve power-conversion efficiencies >17%. Such low voltage losses in the charge separation process have been attributed to a low-driving-force and efficient exciton dissociation. Here, we address the nature of the subpicosecond dynamics of electron/hole transfer in PM6/Y6 solar cells. While previous reports focused on active layers only, we developed a photocurrent-detected two-dimensional spectroscopy to follow the charge transfer in fully operating devices. Our measurements reveal an efficient hole-transfer from the Y6-acceptor to the PM6-donor on the subpicosecond time scale. On the contrary, at the same time scale, no electron-transfer is seen from the donor to the acceptor. These findings, putting ultrafast spectroscopy in action on operating optoelectronic devices, provide insight for further enhancing NFA solar cell performance.
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Affiliation(s)
- Luca Bolzonello
- ICFO
- Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona 08860, Spain
| | - Francisco Bernal-Texca
- ICFO
- Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona 08860, Spain
| | - Luis G. Gerling
- ICFO
- Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona 08860, Spain
| | - Jana Ockova
- ICFO
- Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona 08860, Spain
| | - Elisabetta Collini
- Dipartimento
di Scienze Chimiche, Università degli
Studi di Padova, Padova 35131, Italy
| | - Jordi Martorell
- ICFO
- Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona 08860, Spain
- Departament
de Física, Universitat Politècnica
de Catalunya, Terrassa 08222, Spain
| | - Niek F. van Hulst
- ICFO
- Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona 08860, Spain
- ICREA
- Institució Catalana de Recerca i Estudis Avançats, Barcelona 08010, Spain
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38
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Zhan J, Wang L, Zhang M, Zhu L, Hao T, Zhou G, Zhou Z, Chen J, Zhong W, Qiu C, Leng S, Zou Y, Shi Z, Zhu H, Feng W, Zhang M, Li Y, Zhang Y, Liu F. Manipulating Crystallization Kinetics of Conjugated Polymers in Nonfullerene Photovoltaic Blends toward Refined Morphologies and Higher Performances. Macromolecules 2021. [DOI: 10.1021/acs.macromol.0c02872] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Junzhe Zhan
- School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Lei Wang
- School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Ming Zhang
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, In-situ Center for Physical Science, and Center of Hydrogen Science Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Lei Zhu
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, In-situ Center for Physical Science, and Center of Hydrogen Science Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Tianyu Hao
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, In-situ Center for Physical Science, and Center of Hydrogen Science Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Guanqing Zhou
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, In-situ Center for Physical Science, and Center of Hydrogen Science Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Zichun Zhou
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, In-situ Center for Physical Science, and Center of Hydrogen Science Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Jiajun Chen
- School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Wenkai Zhong
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, In-situ Center for Physical Science, and Center of Hydrogen Science Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Chaoqun Qiu
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, In-situ Center for Physical Science, and Center of Hydrogen Science Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Shifeng Leng
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, In-situ Center for Physical Science, and Center of Hydrogen Science Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Yecheng Zou
- State Key Laboratory of Fluorinated Functional Membrane Materials and Dongyue Future Hydrogen Energy Materials Company, Zibo, Shandong 256401, P. R. China
| | - Zhiwen Shi
- School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Haiming Zhu
- Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang 310027, P. R. China
| | - Wei Feng
- State Key Laboratory of Fluorinated Functional Membrane Materials and Dongyue Future Hydrogen Energy Materials Company, Zibo, Shandong 256401, P. R. China
| | - Maojie Zhang
- Laboratory of Advanced Optoelectronic Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, Jiangsu 215123, P. R. China
| | - Yongfang Li
- Laboratory of Advanced Optoelectronic Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, Jiangsu 215123, P. R. China
| | - Yongming Zhang
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, In-situ Center for Physical Science, and Center of Hydrogen Science Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Feng Liu
- School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, In-situ Center for Physical Science, and Center of Hydrogen Science Shanghai Jiao Tong University, Shanghai 200240, P. R. China
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39
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Song Y, Liu X, Li Y, Nguyen HH, Duan R, Kubarych KJ, Forrest SR, Ogilvie JP. Mechanistic Study of Charge Separation in a Nonfullerene Organic Donor-Acceptor Blend Using Multispectral Multidimensional Spectroscopy. J Phys Chem Lett 2021; 12:3410-3416. [PMID: 33788566 DOI: 10.1021/acs.jpclett.1c00407] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Organic photovoltaics (OPVs) based on nonfullerene acceptors are now approaching commercially viable efficiencies. One key to their success is efficient charge separation with low potential loss at the donor-acceptor heterojunction. Due to the lack of spectroscopic probes, open questions remain about the mechanisms of charge separation. Here, we study charge separation of a model system composed of the donor, poly[(2,6-(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)-benzo[1,2-b:4,5-b']dithiophene))-alt-(5,5-(1',3'-di-2-thienyl-5',7'-bis(2-ethylhexyl)benzo[1',2'-c:4',5'-c']dithiophene-4,8-dione) (PBDB-T), and the nonfullerene acceptor, 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2',3'-d']-s-indaceno[1,2-b:5,6-b']dithiophene (ITIC), using multidimensional spectroscopy spanning the visible to the mid-infrared. We find that bound polaron pairs (BPPs) generated within ITIC domains play a dominant role in efficient hole transfer, transitioning to delocalized polarons within 100 fs. The weak electron-hole binding within the BPPs and the resulting polaron delocalization are key factors for efficient charge separation at nearly zero driving force. Our work provides useful insight into how to further improve the power conversion efficiency in OPVs.
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Affiliation(s)
- Yin Song
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Xiao Liu
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Yongxi Li
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Hoang Huy Nguyen
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Rong Duan
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Kevin J Kubarych
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Stephen R Forrest
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Material Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Jennifer P Ogilvie
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, United States
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40
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Oh CM, Lee J, Park SH, Hwang IW. Carrier losses in non-geminate charge-transferred states of nonfullerene acceptor-based organic solar cells. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2021; 250:119227. [PMID: 33248892 DOI: 10.1016/j.saa.2020.119227] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 11/03/2020] [Accepted: 11/10/2020] [Indexed: 06/12/2023]
Abstract
To understand the current limitations of nonfullerene-based organic solar cells (OSCs), the early-time dynamics of the carrier generation in the high performance bulk heterojunction (BHJ) blend of a semiconducting polymer, PBDB-T, and the low bandgap nonfullerene acceptor, ITIC-m, are investigated. After photoexcitation, photo-induced excitons are separated through the ultrafast (~200 fs) electron transfer process from PBDB-T to ITIC-m and through the fast (3-6 ps) hole transfer process from ITIC-m to PBDB-T. However, a part of the separated charges recombines in the non-geminate (long-range) charge-transferred (CT) states. The yield of mobile carriers is correspondingly decreased by recombination in the CT states. In our measurements, the carrier recombination loss in the CT state is decreased by optimizing the BHJ morphology, especially for showing better electron mobility using a processing additive (1,8-diiodooctane) during the fabrication of the composite film, as evidenced by the decreased CT band intensity at ~30 ps and the increased polaron band intensity, which eventually improve power conversion efficiencies (PCEs).
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Affiliation(s)
- Chang-Mok Oh
- Advanced Photonics Research Institute, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea
| | - Jihoon Lee
- Department of Physics, Pukyong National University, Busan 48513, Republic of Korea
| | - Sung Heum Park
- Department of Physics, Pukyong National University, Busan 48513, Republic of Korea
| | - In-Wook Hwang
- Advanced Photonics Research Institute, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea.
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41
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Adjusting the energy of interfacial states in organic photovoltaics for maximum efficiency. Nat Commun 2021; 12:1772. [PMID: 33741966 PMCID: PMC7979693 DOI: 10.1038/s41467-021-22032-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 02/22/2021] [Indexed: 11/09/2022] Open
Abstract
A critical bottleneck for improving the performance of organic solar cells (OSC) is minimising non-radiative losses in the interfacial charge-transfer (CT) state via the formation of hybrid energetic states. This requires small energetic offsets often detrimental for high external quantum efficiency (EQE). Here, we obtain OSC with both non-radiative voltage losses (0.24 V) and photocurrent losses (EQE > 80%) simultaneously minimised. The interfacial CT states separate into free carriers with ≈40-ps time constant. We combine device and spectroscopic data to model the thermodynamics of charge separation and extraction, revealing that the relatively high performance of the devices arises from an optimal adjustment of the CT state energy, which determines how the available overall driving force is efficiently used to maximize both exciton splitting and charge separation. The model proposed is universal for donor:acceptor (D:A) with low driving forces and predicts which D:A will benefit from a morphology optimization for highly efficient OSC.
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42
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van der Pol TP, Li J, van Gorkom BT, Colberts FJM, Wienk MM, Janssen RAJ. Analysis of the Performance of Narrow-Bandgap Organic Solar Cells Based on a Diketopyrrolopyrrole Polymer and a Nonfullerene Acceptor. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2021; 125:5505-5517. [PMID: 33828634 PMCID: PMC8016210 DOI: 10.1021/acs.jpcc.0c11377] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 02/11/2021] [Indexed: 06/12/2023]
Abstract
The combination of narrow-bandgap diketopyrrolopyrrole (DPP) polymers and nonfullerene acceptors (NFAs) seems well-matched for solar cells that exclusively absorb in the near infrared but they rarely provide high efficiency. One reason is that processing of the active layer is complicated by the fact that DPP-based polymers are generally only sufficiently soluble in chloroform (CF), while NFAs are preferably processed from halogenated aromatic solvents. By using a ternary solvent system consisting of CF, 1,8-diiodooctane (DIO), and chlorobenzene (CB), the short-circuit current density is increased by 50% in solar cells based on a DPP polymer (PDPP5T) and a NFA (IEICO-4F) compared to the use of CF with DIO only. However, the open-circuit voltage and fill factor are reduced. As a result, the efficiency improves from 3.4 to 4.8% only. The use of CB results in stronger aggregation of IEICO-4F as inferred from two-dimensional grazing-incidence wide-angle X-ray diffraction. Photo- and electroluminescence and mobility measurements indicate that the changes in performance can be ascribed to a more aggregated blend film in which charge generation is increased but nonradiative recombination is enhanced because of reduced hole mobility. Hence, while CB is essential to obtain well-ordered domains of IEICO-4F in blends with PDPP5T, the morphology and resulting hole mobility of PDPP5T domains remain suboptimal. The results identify the challenges in processing organic solar cells based on DPP polymers and NFAs as near-infrared absorbing photoactive layers.
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Affiliation(s)
- Tom P.
A. van der Pol
- Molecular
Materials and Nanosystems & Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven 5600 MB, The Netherlands
| | - Junyu Li
- Molecular
Materials and Nanosystems & Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven 5600 MB, The Netherlands
| | - Bas T. van Gorkom
- Molecular
Materials and Nanosystems & Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven 5600 MB, The Netherlands
| | - Fallon J. M. Colberts
- Energy
Engineering, Zuyd University of Applied
Sciences, Nieuw Eyckholt
300, Heerlen 6419 DJ, The Netherlands
| | - Martijn M. Wienk
- Molecular
Materials and Nanosystems & Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven 5600 MB, The Netherlands
| | - René A. J. Janssen
- Molecular
Materials and Nanosystems & Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven 5600 MB, The Netherlands
- Dutch
Institute for Fundamental Energy Research, Eindhoven, 5612 AJ, The Netherlands
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43
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Karuthedath S, Gorenflot J, Firdaus Y, Chaturvedi N, De Castro CSP, Harrison GT, Khan JI, Markina A, Balawi AH, Peña TAD, Liu W, Liang RZ, Sharma A, Paleti SHK, Zhang W, Lin Y, Alarousu E, Lopatin S, Anjum DH, Beaujuge PM, De Wolf S, McCulloch I, Anthopoulos TD, Baran D, Andrienko D, Laquai F. Intrinsic efficiency limits in low-bandgap non-fullerene acceptor organic solar cells. NATURE MATERIALS 2021; 20:378-384. [PMID: 33106652 DOI: 10.1038/s41563-020-00835-x] [Citation(s) in RCA: 109] [Impact Index Per Article: 36.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Accepted: 09/17/2020] [Indexed: 05/20/2023]
Abstract
In bulk heterojunction (BHJ) organic solar cells (OSCs) both the electron affinity (EA) and ionization energy (IE) offsets at the donor-acceptor interface should equally control exciton dissociation. Here, we demonstrate that in low-bandgap non-fullerene acceptor (NFA) BHJs ultrafast donor-to-acceptor energy transfer precedes hole transfer from the acceptor to the donor and thus renders the EA offset virtually unimportant. Moreover, sizeable bulk IE offsets of about 0.5 eV are needed for efficient charge transfer and high internal quantum efficiencies, since energy level bending at the donor-NFA interface caused by the acceptors' quadrupole moments prevents efficient exciton-to-charge-transfer state conversion at low IE offsets. The same bending, however, is the origin of the barrier-less charge transfer state to free charge conversion. Our results provide a comprehensive picture of the photophysics of NFA-based blends, and show that sizeable bulk IE offsets are essential to design efficient BHJ OSCs based on low-bandgap NFAs.
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Affiliation(s)
- Safakath Karuthedath
- KAUST Solar Center, Physical Sciences and Engineering Division (PSE), Materials Science and Engineering Program (MSE), King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia
| | - Julien Gorenflot
- KAUST Solar Center, Physical Sciences and Engineering Division (PSE), Materials Science and Engineering Program (MSE), King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia
| | - Yuliar Firdaus
- KAUST Solar Center, Physical Sciences and Engineering Division (PSE), Materials Science and Engineering Program (MSE), King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia
| | - Neha Chaturvedi
- KAUST Solar Center, Physical Sciences and Engineering Division (PSE), Materials Science and Engineering Program (MSE), King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia
| | - Catherine S P De Castro
- KAUST Solar Center, Physical Sciences and Engineering Division (PSE), Materials Science and Engineering Program (MSE), King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia
| | - George T Harrison
- KAUST Solar Center, Physical Sciences and Engineering Division (PSE), Materials Science and Engineering Program (MSE), King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia
| | - Jafar I Khan
- KAUST Solar Center, Physical Sciences and Engineering Division (PSE), Materials Science and Engineering Program (MSE), King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia
| | | | - Ahmed H Balawi
- KAUST Solar Center, Physical Sciences and Engineering Division (PSE), Materials Science and Engineering Program (MSE), King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia
| | - Top Archie Dela Peña
- KAUST Solar Center, Physical Sciences and Engineering Division (PSE), Materials Science and Engineering Program (MSE), King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia
| | - Wenlan Liu
- Max Planck Institute for Polymer Research, Mainz, Germany
| | - Ru-Ze Liang
- KAUST Solar Center, Physical Sciences and Engineering Division (PSE), Materials Science and Engineering Program (MSE), King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia
| | - Anirudh Sharma
- KAUST Solar Center, Physical Sciences and Engineering Division (PSE), Materials Science and Engineering Program (MSE), King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia
| | - Sri H K Paleti
- KAUST Solar Center, Physical Sciences and Engineering Division (PSE), Materials Science and Engineering Program (MSE), King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia
| | - Weimin Zhang
- KAUST Solar Center, Physical Sciences and Engineering Division (PSE), Materials Science and Engineering Program (MSE), King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia
| | - Yuanbao Lin
- KAUST Solar Center, Physical Sciences and Engineering Division (PSE), Materials Science and Engineering Program (MSE), King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia
| | - Erkki Alarousu
- KAUST Solar Center, Physical Sciences and Engineering Division (PSE), Materials Science and Engineering Program (MSE), King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia
| | - Sergei Lopatin
- Imaging and Characterization Core Laboratory, King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia
| | - Dalaver H Anjum
- Imaging and Characterization Core Laboratory, King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia
| | - Pierre M Beaujuge
- KAUST Solar Center, Physical Sciences and Engineering Division (PSE), Materials Science and Engineering Program (MSE), King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia
| | - Stefaan De Wolf
- KAUST Solar Center, Physical Sciences and Engineering Division (PSE), Materials Science and Engineering Program (MSE), King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia
| | - Iain McCulloch
- KAUST Solar Center, Physical Sciences and Engineering Division (PSE), Materials Science and Engineering Program (MSE), King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia
- Department of Chemistry, University of Oxford, Oxford, UK
| | - Thomas D Anthopoulos
- KAUST Solar Center, Physical Sciences and Engineering Division (PSE), Materials Science and Engineering Program (MSE), King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia
| | - Derya Baran
- KAUST Solar Center, Physical Sciences and Engineering Division (PSE), Materials Science and Engineering Program (MSE), King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia
| | | | - Frédéric Laquai
- KAUST Solar Center, Physical Sciences and Engineering Division (PSE), Materials Science and Engineering Program (MSE), King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia.
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44
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Liu A, Gedda L, Axelsson M, Pavliuk M, Edwards K, Hammarström L, Tian H. Panchromatic Ternary Polymer Dots Involving Sub-Picosecond Energy and Charge Transfer for Efficient and Stable Photocatalytic Hydrogen Evolution. J Am Chem Soc 2021; 143:2875-2885. [PMID: 33541077 PMCID: PMC7917435 DOI: 10.1021/jacs.0c12654] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Indexed: 12/21/2022]
Abstract
Panchromatic ternary polymer dots (Pdots) consisting of two conjugated polymers (PFBT and PFODTBT) based on fluorene and benzothiadiazole groups, and one small molecular acceptor (ITIC) have been prepared and assessed for photocatalytic hydrogen production with the assistance of a Pt cocatalyst. Femtosecond transient absorption spectroscopic studies of the ternary Pdots have revealed both energy and charge transfer processes that occur on the time scale of sub-picosecond between the different components. They result in photogenerated electrons being located mainly at ITIC, which acts as both electron and energy acceptor. Results from cryo-transmission electron microscopy suggest that ITIC forms crystalline phases in the ternary Pdots, facilitating electron transfer from ITIC to the Pt cocatalyst and promoting the final photocatalytic reaction yield. Enhanced light absorption, efficient charge separation, and the ideal morphology of the ternary Pdots have rendered an external quantum efficiency up to 7% at 600 nm. Moreover, the system has shown a high stability over 120 h without obvious degradation of the photocatalysts.
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Affiliation(s)
- Aijie Liu
- Department
of Chemistry-Ångström Lab., Uppsala University, Box 523, SE 751 20, Uppsala, Sweden
| | - Lars Gedda
- Department
of Chemistry-Ångström Lab., Uppsala University, Box 523, SE 751 20, Uppsala, Sweden
| | - Martin Axelsson
- Department
of Chemistry-Ångström Lab., Uppsala University, Box 523, SE 751 20, Uppsala, Sweden
| | - Mariia Pavliuk
- Department
of Chemistry-Ångström Lab., Uppsala University, Box 523, SE 751 20, Uppsala, Sweden
| | - Katarina Edwards
- Department
of Chemistry-Ångström Lab., Uppsala University, Box 523, SE 751 20, Uppsala, Sweden
| | - Leif Hammarström
- Department
of Chemistry-Ångström Lab., Uppsala University, Box 523, SE 751 20, Uppsala, Sweden
| | - Haining Tian
- Department
of Chemistry-Ångström Lab., Uppsala University, Box 523, SE 751 20, Uppsala, Sweden
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45
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Sun Y, Gao HH, Wu S, Meng L, Wan X, Li M, Ma Z, Guo Z, Li S, Zhang H, Li C, Chen Y. Improving current and mitigating energy loss in ternary organic photovoltaics enabled by two well-compatible small molecule acceptors. Sci China Chem 2021. [DOI: 10.1007/s11426-020-9921-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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46
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Jia Z, Chen Z, Chen X, Bai L, Zhu H, Yang YM. Understanding of the Nearly Linear Tunable Open-Circuit Voltages in Ternary Organic Solar Cells Based on Two Non-fullerene Acceptors. J Phys Chem Lett 2021; 12:151-156. [PMID: 33320004 DOI: 10.1021/acs.jpclett.0c03177] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Although the power conversion efficiencies (PCEs) of the state-of-the-art organic solar cells (OSCs) have exceeded 17%, the organic photovoltaic devices still suffer from considerable voltage losses compared with the inorganic or perovskite solar cells. Therefore, the optimization of open-circuit voltage (VOC) is of great significance for the improvement of the photovoltaic performance of OSCs. The origins of VOC have been well-established in the binary system; however, the understanding of VOC in non-fullerene acceptor (NFA)-based ternary OSCs is still lacking. Herein, we have developed a series of ternary organic photovoltaic devices, exhibiting nearly linear increased VOC as the increase of ITIC third content. We found that both the effective charge-transfer (CT) states and the nonradiative recombination losses of the bulk-heterojunction (BHJ) are altered in the ternary blends, and they collectively contribute to the tunable VOC. Our results provide a perspective for understanding the origin of VOC in NFA-based ternary OSCs.
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Affiliation(s)
- Ziyan Jia
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Zeng Chen
- Center for Chemistry of High-Performance & Novel Materials, Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Xu Chen
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Lizhong Bai
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Haiming Zhu
- Center for Chemistry of High-Performance & Novel Materials, Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Yang Michael Yang
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China
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47
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Bai Y, Xue LW, Wang HQ, Zhang ZG. Research Advances on Benzotriazole-based Organic Photovoltaic Materials. ACTA CHIMICA SINICA 2021. [DOI: 10.6023/a21050193] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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48
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Hinrichsen TF, Chan CCS, Ma C, Paleček D, Gillett A, Chen S, Zou X, Zhang G, Yip HL, Wong KS, Friend RH, Yan H, Rao A, Chow PCY. Long-lived and disorder-free charge transfer states enable endothermic charge separation in efficient non-fullerene organic solar cells. Nat Commun 2020; 11:5617. [PMID: 33154367 PMCID: PMC7645751 DOI: 10.1038/s41467-020-19332-5] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 09/28/2020] [Indexed: 11/17/2022] Open
Abstract
Organic solar cells based on non-fullerene acceptors can show high charge generation yields despite near-zero donor–acceptor energy offsets to drive charge separation and overcome the mutual Coulomb attraction between electron and hole. Here, we use time-resolved optical spectroscopy to show that free charges in these systems are generated by thermally activated dissociation of interfacial charge-transfer states that occurs over hundreds of picoseconds at room temperature, three orders of magnitude slower than comparable fullerene-based systems. Upon free electron–hole encounters at later times, both charge-transfer states and emissive excitons are regenerated, thus setting up an equilibrium between excitons, charge-transfer states and free charges. Our results suggest that the formation of long-lived and disorder-free charge-transfer states in these systems enables them to operate closely to quasi-thermodynamic conditions with no requirement for energy offsets to drive interfacial charge separation and achieve suppressed non-radiative recombination. Designing efficient organic solar cells is limited by the energy required to overcome the mutual Coulomb attraction between electron and hole. Here, the authors reveal long-lived and disorder-free charge-transfer states enable efficient endothermic charge separation in non-fullerene systems with marginal energy offset.
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Affiliation(s)
- Ture F Hinrichsen
- Cavendish Laboratory, University of Cambridge, Cambridge, CB3 0HE, UK
| | - Christopher C S Chan
- Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay,, Hong Kong, China
| | - Chao Ma
- Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay,, Hong Kong, China
| | - David Paleček
- Cavendish Laboratory, University of Cambridge, Cambridge, CB3 0HE, UK
| | - Alexander Gillett
- Cavendish Laboratory, University of Cambridge, Cambridge, CB3 0HE, UK
| | - Shangshang Chen
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay,, Hong Kong, China
| | - Xinhui Zou
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay,, Hong Kong, China
| | - Guichuan Zhang
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, China
| | - Hin-Lap Yip
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, China
| | - Kam Sing Wong
- Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay,, Hong Kong, China
| | - Richard H Friend
- Cavendish Laboratory, University of Cambridge, Cambridge, CB3 0HE, UK.
| | - He Yan
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay,, Hong Kong, China.
| | - Akshay Rao
- Cavendish Laboratory, University of Cambridge, Cambridge, CB3 0HE, UK.
| | - Philip C Y Chow
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay,, Hong Kong, China. .,Department of Mechanical Engineering, The University of Hong Kong, Pokfulam, Hong Kong, China.
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49
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An N, Cai Y, Wu H, Tang A, Zhang K, Hao X, Ma Z, Guo Q, Ryu HS, Woo HY, Sun Y, Zhou E. Solution-Processed Organic Solar Cells with High Open-Circuit Voltage of 1.3 V and Low Non-Radiative Voltage Loss of 0.16 V. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2002122. [PMID: 32844465 DOI: 10.1002/adma.202002122] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 07/16/2020] [Indexed: 06/11/2023]
Abstract
Compared with inorganic or perovskite solar cells, the relatively large non-radiative recombination voltage losses (ΔVnon-rad ) in organic solar cells (OSCs) limit the improvement of the open-circuit voltage (Voc ). Herein, OSCs are fabricated by adopting two pairs of D-π-A polymers (PBT1-C/PBT1-C-2Cl and PBDB-T/PBDB-T-2Cl) as electron donors and a wide-bandgap molecule BTA3 as the electron acceptor. In these blends, a charge-transfer state energy (ECT ) as high as 1.70-1.76 eV is achieved, leading to small energetic differences between the singlet excited states and charge-transfer states (ΔECT ≈ 0.1 eV). In addition, after introducing chlorine atoms into the π-bridge or the side chain of benzodithiophene (BDT) unit, electroluminescence external quantum efficiencies as high as 1.9 × 10-3 and 1.0 × 10-3 are realized in OSCs based on PBTI-C-2Cl and PBDB-T-2Cl, respectively. Their corresponding ΔVnon-rad are 0.16 and 0.17 V, which are lower than those of OSCs based on the analog polymers without a chlorine atom (0.21 and 0.24 V for PBT1-C and PBDB-T, respectively), resulting in high Voc of 1.3 V. The ΔVnon-rad of 0.16 V and Voc of 1.3 V achieved in PBT1-C-2Cl:BTA3 OSCs are thought to represent the best values for solution-processed OSCs reported in the literature so far.
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Affiliation(s)
- Ning An
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Yunhao Cai
- School of Chemistry, Beihang University, Beijing, 100191, China
| | - Hongbo Wu
- Center for Advanced Low-Dimension Materials, State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai, 201620, China
| | - Ailing Tang
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Kangning Zhang
- School of Physics State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, China
| | - Xiaotao Hao
- School of Physics State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, China
| | - Zaifei Ma
- Center for Advanced Low-Dimension Materials, State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai, 201620, China
| | - Qiang Guo
- Henan Institute of Advanced Technology, Zhengzhou University, Zhengzhou, 450003, China
| | - Hwa Sook Ryu
- Department of Chemistry, College of Scyience, Korea University, Seoul, 136-713, Republic of Korea
| | - Han Young Woo
- Department of Chemistry, College of Scyience, Korea University, Seoul, 136-713, Republic of Korea
| | - Yanming Sun
- School of Chemistry, Beihang University, Beijing, 100191, China
| | - Erjun Zhou
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
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50
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Xiang Q, Liu Y, Chen Y, Long J. A modulation method of endohedral fullerene material: Using the external electric field. Chem Phys Lett 2020. [DOI: 10.1016/j.cplett.2020.137849] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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