1
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Zhang Z, Xu C, Sun Q, Zhu Y, Yan W, Cai G, Li Y, Si W, Lu X, Xu W, Yang Y, Lin Y. Delocalizing Excitation for Highly-Active Organic Photovoltaic Catalysts. Angew Chem Int Ed Engl 2024; 63:e202402343. [PMID: 38639055 DOI: 10.1002/anie.202402343] [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: 02/01/2024] [Revised: 03/29/2024] [Accepted: 04/19/2024] [Indexed: 04/20/2024]
Abstract
Localized excitation in traditional organic photocatalysts typically prevents the generation and extraction of photo-induced free charge carriers, limiting their activity enhancement under illumination. Here, we enhance delocalized photoexcitation of small molecular photovoltaic catalysts by weakening their electron-phonon coupling via rational fluoro-substitution. The optimized 2FBP-4F catalyst we develop here exhibits a minimized Huang-Rhys factor of 0.35 in solution, high dielectric constant and strong crystallization in the solid state. As a result, the energy barrier for exciton dissociation is decreased, and more importantly, polarons are unusually observed in 2FBP-4F nanoparticles (NPs). With the increased hole transfer efficiency and prolonged charge carrier lifetime highly related to enhanced exciton delocalization, the PM6 : 2FBP-4F heterojunction NPs at varied concentration exhibit much higher optimized photocatalytic activity (207.6-561.8 mmol h-1 g-1) for hydrogen evolution than the control PM6 : BP-4F and PM6 : 2FBP-6F NPs, as well as other reported photocatalysts under simulated solar light (AM 1.5G, 100 mW cm-2).
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Affiliation(s)
- Zhenzhen Zhang
- 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 of Sciences, Beijing, 100049, China
| | - Chaoying Xu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Qianlu Sun
- Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, China
| | - Yufan Zhu
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Wenlong Yan
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Guilong Cai
- Department of Physics, The Chinese University of Hong Kong, New Territories, Hong Kong, 999077, China
| | - Yawen Li
- 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 of Sciences, Beijing, 100049, China
| | - Wenqin Si
- 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 of Sciences, Beijing, 100049, China
| | - Xinhui Lu
- Department of Physics, The Chinese University of Hong Kong, New Territories, Hong Kong, 999077, China
| | - Weigao Xu
- Key Laboratory of Mesoscopic Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, China
| | - Ye Yang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Yuze Lin
- 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 of Sciences, Beijing, 100049, China
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2
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Cheng C, Yu J, Xu D, Wang L, Liang G, Zhang L, Jaroniec M. In-situ formatting donor-acceptor polymer with giant dipole moment and ultrafast exciton separation. Nat Commun 2024; 15:1313. [PMID: 38350993 PMCID: PMC10864376 DOI: 10.1038/s41467-024-45604-5] [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: 09/22/2023] [Accepted: 01/30/2024] [Indexed: 02/15/2024] Open
Abstract
Donor-acceptor semiconducting polymers present countless opportunities for application in photocatalysis. Previous studies have showcased their advantages through direct bottom-up methods. Unfortunately, these approaches often involve harsh reaction conditions, overlooking the impact of uncontrolled polymerization degrees on photocatalysis. Besides, the mechanism behind the separation of electron-hole pairs (excitons) in donor-acceptor polymers remains elusive. This study presents a post-synthetic method involving the light-induced transformation of the building blocks of hyper-cross-linked polymers from donor-carbon-donor to donor-carbon-acceptor states, resulting in a polymer with a substantial intramolecular dipole moment. Thus, excitons are efficiently separated in the transformed polymer. The utility of this strategy is exemplified by the enhanced photocatalytic hydrogen peroxide synthesis. Encouragingly, our observations reveal the formation of intramolecular charge transfer states using time-resolved techniques, confirming transient exciton behavior involving separation and relaxation. This light-induced method not only guides the development of highly efficient donor-acceptor polymer photocatalysts but also applies to various fields, including organic solar cells, light-emitting diodes, and sensors.
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Affiliation(s)
- Chang Cheng
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 430070, Wuhan, P. R. China
| | - Jiaguo Yu
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 430070, Wuhan, P. R. China.
- Laboratory of Solar Fuel, Faculty of Materials Science and Chemistry, China University of Geosciences, 388 Lumo Road, Wuhan, 430074, P. R. China.
| | - Difa Xu
- Hunan Key Laboratory of Applied Environmental Photocatalysis, Changsha University, 98 Hongshan Road, Changsha, 410022, P.R. China
| | - Lei Wang
- Hubei Key Laboratory of Low Dimensional Optoelectronic Material and Devices, Hubei University of Arts and Science, Xiangyang, 441053, P. R. China
| | - Guijie Liang
- Hubei Key Laboratory of Low Dimensional Optoelectronic Material and Devices, Hubei University of Arts and Science, Xiangyang, 441053, P. R. China
| | - Liuyang Zhang
- Laboratory of Solar Fuel, Faculty of Materials Science and Chemistry, China University of Geosciences, 388 Lumo Road, Wuhan, 430074, P. R. China.
| | - Mietek Jaroniec
- Department of Chemistry and Biochemistry, Kent State University, Kent, OH, 44242, USA.
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3
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Zheng Y, Venkatesh R, Callaway CP, Viersen C, Fagbohungbe KH, Liu AL, Risko C, Reichmanis E, Silva-Acuña C. Chain Conformation and Exciton Delocalization in a Push-Pull Conjugated Polymer. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2023; 35:10258-10267. [PMID: 38107193 PMCID: PMC10720347 DOI: 10.1021/acs.chemmater.3c02665] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 10/24/2023] [Indexed: 12/19/2023]
Abstract
Linear and nonlinear optical line shapes reveal details of excitonic structure in polymer semiconductors. We implement absorption, photoluminescence, and transient absorption spectroscopies in DPP-DTT, an electron push-pull copolymer, to explore the relationship between their spectral line shapes and chain conformation, deduced from resonance Raman spectroscopy and from ab initio calculations. The viscosity of precursor polymer solutions before film casting displays a transition that suggests gel formation above a critical concentration. Upon crossing this viscosity deflection concentration, the line shape analysis of the absorption spectra within a photophysical aggregate model reveals a gradual increase in interchain excitonic coupling. We also observe a red-shifted and line-narrowed steady-state photoluminescence spectrum along with increasing resonance Raman intensity in the stretching and torsional modes of the dithienothiophene unit, which suggests a longer exciton coherence length along the polymer-chain backbone. Furthermore, we observe a change of line shape in the photoinduced absorption component of the transient absorption spectrum. The derivative-like line shape may originate from two possibilities: a new excited-state absorption or Stark effect, both of which are consistent with the emergence of a high-energy shoulder as seen in both photoluminescence and absorption spectra. Therefore, we conclude that the exciton is more dispersed along the polymer chain backbone with increasing concentrations, leading to the hypothesis that polymer chain order is enhanced when the push-pull polymers are processed at higher concentrations. Thus, tuning the microscopic chain conformation by concentration would be another factor of interest when considering the polymer assembly pathways for pursuing large-area and high-performance organic optoelectronic devices.
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Affiliation(s)
- Yulong Zheng
- School
of Chemistry and Biochemistry, Georgia Institute
of Technology, 901 Atlantic Drive, Atlanta, Georgia 30332, United States
| | - Rahul Venkatesh
- School
of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332, United States
| | - Connor P. Callaway
- Department
of Chemistry and Center for Applied Energy Research, University of Kentucky, Lexington, Kentucky 40506, United States
| | - Campbell Viersen
- School
of Chemistry and Biochemistry, Georgia Institute
of Technology, 901 Atlantic Drive, Atlanta, Georgia 30332, United States
| | - Kehinde H. Fagbohungbe
- Department
of Chemistry and Center for Applied Energy Research, University of Kentucky, Lexington, Kentucky 40506, United States
| | - Aaron L. Liu
- School
of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332, United States
| | - Chad Risko
- Department
of Chemistry and Center for Applied Energy Research, University of Kentucky, Lexington, Kentucky 40506, United States
| | - Elsa Reichmanis
- Department
of Chemical & Biomolecular Engineering, Lehigh University, 124 East Morton Street, Bethlehem, Pennsylvania 18015, United States
| | - Carlos Silva-Acuña
- School
of Chemistry and Biochemistry, Georgia Institute
of Technology, 901 Atlantic Drive, Atlanta, Georgia 30332, United States
- School
of Physics, Georgia Institute of Technology, 837 State Street, Atlanta, Georgia 30332, United States
- School
of Materials Science and Engineering, Georgia
Institute of Technology, North Avenue, Atlanta, Georgia 30332, United States
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4
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Li Q, Wang R, Yu T, Wang X, Zhang ZG, Zhang Y, Xiao M, Zhang C. Long-Range Charge Separation Enabled by Intramoiety Delocalized Excitations in Copolymer Donors in Organic Photovoltaic Blends. J Phys Chem Lett 2023; 14:7498-7506. [PMID: 37581453 DOI: 10.1021/acs.jpclett.3c01861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/16/2023]
Abstract
For over two decades, most high-performance organic photovoltaics (OPVs) have been made with donor:acceptor bulk heterojunctions with domain sizes limited by exciton diffusion, where charge separation mostly takes place through the dissociation of the interfacial charge-transfer (xCT) excitons. Recently, nonfullerene acceptor (NFA)-based OPVs have shown excellent compatibility to device structures with large domains in active layers. However, it remains elusive how the excitations that are distant from the interfaces are converted into free charges. Here, we report the identification of a new charge separation channel in model copolymer/NFA blends mediated by intra-moiety delocalized excitations in both planar heterojunctions and donor-enriched bulk heterojunctions. The delocalized excitations induced by interchromophore electronic interactions in copolymer donors mediate the long-range charge separation and dissociate into free charges without forming the bound xCT states first, releasing the constraints associated with the short exciton diffusion length in organic materials. The long-range charge separation mechanism uncovered in this work, in cooperation with the short-range xCT-mediated pathway, holds the potential to further optimize OPVs with diverse device structures.
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Affiliation(s)
- Qian Li
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Rui Wang
- College of Physics, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, China
- Key Laboratory of Aerospace Information Materials and Physics (NUAA), MIIT, Nanjing 211106, China
| | - Tao Yu
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Xiaoyong Wang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing 210093, 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
| | - Yuan Zhang
- School of Chemistry, Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing 100191, 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
| | - 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 226001, China
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5
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Li Q, Wang R, Zhang C. The Dynamics of Delocalized Excitations in Organic Solar Cells with Nonfullerene Acceptors. J Phys Chem Lett 2023; 14:3031-3038. [PMID: 36946622 DOI: 10.1021/acs.jpclett.2c03911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Recently, the performance of organic solar cells has been markedly improved benefiting from the development of nonfullerene acceptors (NFAs) with acceptor-donor-acceptor structures. Arising from the intermolecular electronic interactions between the electron donating and accepting units, intramoiety and interfacial delocalized excitations make a substantial contribution to the photocurrent generation. In this Perspective, we discuss recent studies on the excited-state dynamics responsible for the working mechanism in NFA-based organic solar cells and emphasize the dynamics of delocalized excitations in charge generation and recombination processes. The intramoiety delocalized excitations in NFAs enable charge separation without forming interfacial charge-transfer excitons first, allowing efficient photocharge generation in planar heterojunctions with reduced interfacial energy loss. We suggest a few research directions in elucidating the performance-limited processes toward the further optimization of NFA-based devices.
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Affiliation(s)
- Qian Li
- 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
| | - Chunfeng Zhang
- National Laboratory of Solid-State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing 210093, China
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6
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Hsieh CM, Hsiao HC, Yamada Y, Wu WR, Jeng US, Su CJ, Lin YS, Murata M, Chang YJ, Chuang SC. Promoting the Efficiency and Stability of Nonfullerene Organic Photovoltaics by Incorporating Open-Cage [60]Fullerenes in the Nonfullerene Nanocrystallites. ACS APPLIED MATERIALS & INTERFACES 2022; 14:39109-39119. [PMID: 35976775 DOI: 10.1021/acsami.2c06354] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The device efficiency of PM6:Y6-based nonfullerene organic solar cells is fast advanced recently. To maintain organic solar cells (OSCs) with high power conversion efficiency over 16% in long-term operation, however, remains a challenge. Here, a novel non-volatile additive, an open-cage [60]fullerene (8OC60Me), is incorporated into PM6:Y6-based OSCs for high-performance with high durability. With optimized addition of 1.0 wt % 8OC60Me, the PCE value of PM6:Y6/8OC60Me OSCs can be promoted to 16.5% from 15.0%. Most strikingly, such a high PCE performance can maintain nearly 100% for over 500 h at room temperature; at an elevated operation temperature of 80 °C, the PCE can be stabilized above 15.0% after 45 h of operation. Grazing incidence small- and wide- angle X-ray scattering studies reveal improved orientation and crystallinity of Y6 in a fractal-like network structure of PM6 in PM6:Y6/8OC60Me films under in situ annealing, parallel to the enhanced electron mobility. Analysis of charge distributions lines up possible van der Waals interaction between the thienyl/carbonyl moiety of 8OC60Me and difluorophenyl-based FIC-end groups of Y6. This result is of great contrast to those devices with the best-selling PC61BM as the additives─8OC60Me might be of interest to be incorporated into future Y6-based OSCs for concomitantly improved PCE and excellent stability.
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Affiliation(s)
- Cheng-Ming Hsieh
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, 30010 Hsinchu, Taiwan
| | - Huan-Chang Hsiao
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, 30010 Hsinchu, Taiwan
| | - Yuto Yamada
- Department of Applied Chemistry, Osaka Institute of Technology, Osaka 535-8585, Japan
| | - Wei-Ru Wu
- National Synchrotron Radiation Research Center, Hsinchu Science Park, Hsinchu 30076, Taiwan
| | - U-Ser Jeng
- National Synchrotron Radiation Research Center, Hsinchu Science Park, Hsinchu 30076, Taiwan
- Department of Chemical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Chun-Jen Su
- Department of Chemical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Ying-Sheng Lin
- Department of Chemistry, Tunghai University, Taichung City 40704, Taiwan
| | - Michihisa Murata
- Department of Applied Chemistry, Osaka Institute of Technology, Osaka 535-8585, Japan
| | - Yuan Jay Chang
- Department of Chemistry, Tunghai University, Taichung City 40704, Taiwan
| | - Shih-Ching Chuang
- Department of Applied Chemistry, National Yang Ming Chiao Tung University, 30010 Hsinchu, Taiwan
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7
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Polak DW, do Casal MT, Toldo JM, Hu X, Amoruso G, Pomeranc O, Heeney M, Barbatti M, Ashfold MNR, Oliver TAA. Probing the electronic structure and photophysics of thiophene-diketopyrrolopyrrole derivatives in solution. Phys Chem Chem Phys 2022; 24:20138-20151. [PMID: 35993400 PMCID: PMC9429679 DOI: 10.1039/d2cp03238d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 08/15/2022] [Indexed: 11/21/2022]
Abstract
Diketopyrrolopyrroles are a popular class of electron-withdrawing unit in optoelectronic materials. When combined with electron donating side-chain functional groups such as thiophenes, they form a very broad class of donor-acceptor molecules: thiophene-diketopyrrolopyrroles (TDPPs). Despite their widescale use in biosensors and photovoltaic materials, studies have yet to establish the important link between the electronic structure of the specific TDPP and the critical optical properties. To bridge this gap, ultrafast transient absorption with 22 fs time resolution has been used to explore the photophysics of three prototypical TDPP molecules: a monomer, dimer and polymer in solution. Interpretation of experimental data was assisted by a recent high-level theoretical study, and additional density functional theory calculations. These studies show that the photophysics of these molecular prototypes under visible photoexcitation are determined by just two excited electronic states, having very different electronic characters (one is optically bright, the other dark), their relative energetic ordering and the timescales for internal conversion from one to the other and/or to the ground state. The underlying difference in electronic structure alters the branching between these excited states and their associated dynamics. In turn, these factors dictate the fluorescence quantum yields, which are shown to vary by ∼1-2 orders of magnitude across the TDPP prototypes investigated here. The fast non-radiative transfer of molecules from the bright to dark states is mediated by conical intersections. Remarkably, wavepacket signals in the measured transient absorption data carry signatures of the nuclear motions that enable mixing of the electronic-nuclear wavefunction and facilitate non-adiabatic coupling between the bright and dark states.
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Affiliation(s)
- Daniel W Polak
- School of Chemistry, Cantock's Close, University of Bristol, Bristol, BS8 1TS, UK.
| | | | | | - Xiantao Hu
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, White City Campus, London, W12 0BZ, UK
| | - Giordano Amoruso
- School of Chemistry, Cantock's Close, University of Bristol, Bristol, BS8 1TS, UK.
| | - Olivia Pomeranc
- School of Chemistry, Cantock's Close, University of Bristol, Bristol, BS8 1TS, UK.
| | - Martin Heeney
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, White City Campus, London, W12 0BZ, UK
| | - Mario Barbatti
- Aix Marseille Université, CNRS, ICR, Marseille, France
- Institut Universitaire de France, 75231, Paris, France
| | - Michael N R Ashfold
- School of Chemistry, Cantock's Close, University of Bristol, Bristol, BS8 1TS, UK.
| | - Thomas A A Oliver
- School of Chemistry, Cantock's Close, University of Bristol, Bristol, BS8 1TS, UK.
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8
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Zhao N, Zhang R, Zou X, Su X, Dang F, Wen G, Zhang W, Zheng K, Chen H, Wu K. Photoinduced Polaron Formation in a Polymerized Electron-Acceptor Semiconductor. J Phys Chem Lett 2022; 13:5143-5150. [PMID: 35658092 DOI: 10.1021/acs.jpclett.2c01015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Polymerized small molecular acceptor (PSMA) based all-polymer solar cells (all-PSC) have achieved power conversion efficiencies (PCE) over 16%, and the PSMA is considered to hold great promise for further improving the performance of all-PSC. Yet, in comparison with that of the polymer donor, the photophysics of a polymerized acceptor remains poorly understood. Herein, the excited state dynamics in a polymerized acceptor PZT810 was comprehensively investigated under various pump intensities and photon energies. The excess excitation energy was found to play a key role in excitons dissociation into free polarons for neat PSMA films, while free polarons cannot be generated from the polaron pairs in neat acceptor films. This work reveals an in-depth understanding of relaxation dynamics for PSMAs and that the underlying photophysical origin of PSMA can be mediated by excitation energies and intensities. These results would benefit the realization of the working mechanism for all-PSC and the designing of new PSMAs.
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Affiliation(s)
- Ningjiu Zhao
- Songshan Lake Materials Laboratory, Dongguan, 523808, China
| | - Rui Zhang
- Department of Physics, Chemsitry and Biology (IFM), Linköping University, Linköping, SE-58183, Sweden
| | - Xianshao Zou
- Division of Chemical Physics, Lund University, Lund, 22100, Sweden
| | - Xiaojun Su
- Department of Basic Courses, Guangzhou Maritime University, Guangzhou, 510725, China
| | - Fan Dang
- Songshan Lake Materials Laboratory, Dongguan, 523808, China
| | - Guanzhao Wen
- School of Physics and Materials Science, Guangzhou University, Guangzhou, 510006, China
| | - Wei Zhang
- School of Physics and Materials Science, Guangzhou University, Guangzhou, 510006, China
- Research Center for Advanced Information Materials (CAIM), Huangpu Research and Graduate School of Guangzhou University, Guangzhou, 510006, China
- Guangzhou University-Linköping University Research Center on Urban Sustainable Development, Guangzhou University, Guangzhou, 510006, China
| | - Kaibo Zheng
- Division of Chemical Physics, Lund University, Lund, 22100, Sweden
| | - Hailong Chen
- Songshan Lake Materials Laboratory, Dongguan, 523808, China
| | - Kehui Wu
- Songshan Lake Materials Laboratory, Dongguan, 523808, China
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9
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Lan ZA, Chi X, Wu M, Zhang X, Chen X, Zhang G, Wang X. Molecular Design of Covalent Triazine Frameworks with Anisotropic Charge Migration for Photocatalytic Hydrogen Production. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2200129. [PMID: 35261149 DOI: 10.1002/smll.202200129] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Revised: 02/16/2022] [Indexed: 06/14/2023]
Abstract
Covalent triazine frameworks (CTFs) represent promising polymeric photocatalysts for photocatalytic hydrogen production with visible light. However, the separation and transfer of charges in CTFs are isotropic because of the uniform distribution of donor-acceptor motifs in the skeleton. Herein, to achieve the anisotropic charge carrier separation and migration, thiophene (Th) or benzothiadiazole (BT) unit is selected as the dopant to modify the molecular structure of CTF-based photocatalysts. Both theoretical and experimental studies reveal that the incorporation of Th or BT units induces the anisotropic charge carrier separation and migration at the interface of CTFs. The optimized polymer manifests a much enhanced photocatalytic activity for photocatalytic hydrogen production with visible light, and thus this study provides a useful tool to design conjugated polymer photocatalysts at the molecular level for solar energy conversion.
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Affiliation(s)
- Zhi-An Lan
- State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, Fujian, 350116, China
- College of Chemical Engineering, Fuzhou University, Fuzhou, Fujian, 350116, China
| | - Xu Chi
- State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, Fujian, 350116, China
| | - Meng Wu
- State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, Fujian, 350116, China
| | - Xirui Zhang
- State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, Fujian, 350116, China
| | - Xiong Chen
- State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, Fujian, 350116, China
| | - Guigang Zhang
- State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, Fujian, 350116, China
| | - Xinchen Wang
- State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, Fujian, 350116, China
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10
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Azzouzi M, Gallop NP, Eisner F, Yan J, Zheng X, Cha H, He Q, Fei Z, Heeney M, Bakulin AA, Nelson J. Reconciling models of interfacial state kinetics and device performance in organic solar cells: impact of the energy offsets on the power conversion efficiency. ENERGY & ENVIRONMENTAL SCIENCE 2022; 15:1256-1270. [PMID: 35419090 PMCID: PMC8924960 DOI: 10.1039/d1ee02788c] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 01/04/2022] [Indexed: 06/14/2023]
Abstract
Achieving the simultaneous increases in the open circuit voltage (V oc), short circuit current (J sc) and fill factor (FF) necessary to further increase the power conversion efficiency (PCE) of organic photovoltaics (OPV) requires a unified understanding of how molecular and device parameters affect all three characteristics. In this contribution, we introduce a framework that for the first time combines different models that have been used separately to describe the different steps of the charge generation and collection processes in OPV devices: a semi-classical rate model for charge recombination processes in OPV devices, zero-dimensional kinetic models for the photogeneration process and exciton dissociation and one-dimensional semiconductor device models. Using this unified multi-scale model in conjunction with experimental techniques (time-resolved absorption spectroscopy, steady-state and transient optoelectronic measurements) that probe the various steps involved in charge generation we can shed light on how the energy offsets in a series of polymer: non-fullerene devices affect the charge carrier generation, collection, and recombination properties of the devices. We find that changing the energy levels of the donor significantly affects not only the transition rates between local-exciton (LE) and charge-transfer (CT) states, but also significantly changes the transition rates between CT and charge-separated (CS) states, challenging the commonly accepted picture of charge generation and recombination. These results show that in order to obtain an accurate picture of charge generation in OPV devices, a variety of different experimental techniques under different conditions in conjunction with a comprehensive model of processes occurring at different time-scales are required.
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Affiliation(s)
- Mohammed Azzouzi
- Department of Physics and Centre for Plastic Electronics, Imperial College London London SW7 2AZ UK
| | - Nathaniel P Gallop
- Department of Chemistry and Centre for Processable Electronics, Imperial College London London W12 0BZ UK
| | - Flurin Eisner
- Department of Physics and Centre for Plastic Electronics, Imperial College London London SW7 2AZ UK
| | - Jun Yan
- Department of Physics and Centre for Plastic Electronics, Imperial College London London SW7 2AZ UK
| | - Xijia Zheng
- Department of Chemistry and Centre for Processable Electronics, Imperial College London London W12 0BZ UK
| | - Hyojung Cha
- Department of Chemistry and Centre for Processable Electronics, Imperial College London London W12 0BZ UK
- Department of Hydrogen & Renewable Energy, Kyungpook National University Daegu 41566 Republic of Korea
| | - Qiao He
- Department of Chemistry and Centre for Processable Electronics, Imperial College London London W12 0BZ UK
| | - Zhuping Fei
- Department of Chemistry and Centre for Processable Electronics, Imperial College London London W12 0BZ UK
- Institute of Molecular Plus, Tianjin Key Laboratory of Molecular Optoelectronic Science, Tianjin University Tianjin 300072 P. R. China
| | - Martin Heeney
- Department of Chemistry and Centre for Processable Electronics, Imperial College London London W12 0BZ UK
| | - Artem A Bakulin
- Department of Chemistry and Centre for Processable Electronics, Imperial College London London W12 0BZ UK
| | - Jenny Nelson
- Department of Physics and Centre for Plastic Electronics, Imperial College London London SW7 2AZ UK
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11
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Nho HW, Park WW, Lee B, Kim S, Yang C, Kwon OH. Intrachain photophysics of a donor-acceptor copolymer. Phys Chem Chem Phys 2021; 24:1982-1992. [PMID: 34897314 DOI: 10.1039/d1cp04093f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
By taking advantage of bulk-heterojunction structures formed by blending conjugated donor polymers and non-fullerene acceptors, organic photovoltaic devices have recently attained promising power conversion efficiencies of above 18%. For optimizing organic photovoltaic devices, it is essential to understand the elementary processes that constitute light harvesters. Utilising femtosecond-resolved spectroscopic techniques that can access the timescales of locally excited (LE) state and charge-transfer (CT)/-separated (CS) states, herein we explored their photophysics in single chains of the top-notch performance donor-acceptor polymer, PM6, which has been widely used as a donor in state-of-the-art non-fullerene organic photovoltaic devices, in a single LE state per chain regime. Our observations revealed the ultrafast formation of a CT state and its equilibrium with the parent LE state. From the chain-length dependence of their lifetimes, the equilibrated states were found to idle until they reach a chain folding. At the chain folding, the CT state transforms into an interchain CT state that bifurcates into forming a CS state or annihilation within a picosecond. The observation of prevalent nonexponential behaviour in the relaxation of the transient species is attributed to the wide chain-length distribution that determines the emergence of the chain foldings in a single chain, thus, the lifetime of a LE and equilibrated CT states. Our findings indicate that the abundance of chain folding, where the generation of the "reactive" CS state is initiated from the interchain CT state, is essential for maximising charge carriers in organic photovoltaic devices based on PM6.
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Affiliation(s)
- Hak-Won Nho
- Department of Chemistry, College of Natural Sciences, Ulsan National Institute of Science and Technology (UNIST), Room 415, Advanced Material Research Building (103), 50 UNIST-gil, Eonyang-eup, Ulju-gun, Ulsan 44919, Republic of Korea. .,Center for Soft and Living Matter, Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
| | - Won-Woo Park
- Department of Chemistry, College of Natural Sciences, Ulsan National Institute of Science and Technology (UNIST), Room 415, Advanced Material Research Building (103), 50 UNIST-gil, Eonyang-eup, Ulju-gun, Ulsan 44919, Republic of Korea.
| | - Byongkyu Lee
- Department of Energy Engineering, School of Energy and Chemical Engineering, Perovtronics Research Center, Low Dimensional Carbon Materials Center, Ulsan National Institute of Science and Technology (UNIST), Room 701-4, 2nd Engineering Building (104), 50 UNIST-gil, Eonyang-eup, Ulju-gun, Ulsan 44919, Republic of Korea.
| | - Seoyoung Kim
- Department of Energy Engineering, School of Energy and Chemical Engineering, Perovtronics Research Center, Low Dimensional Carbon Materials Center, Ulsan National Institute of Science and Technology (UNIST), Room 701-4, 2nd Engineering Building (104), 50 UNIST-gil, Eonyang-eup, Ulju-gun, Ulsan 44919, Republic of Korea.
| | - Changduk Yang
- Department of Energy Engineering, School of Energy and Chemical Engineering, Perovtronics Research Center, Low Dimensional Carbon Materials Center, Ulsan National Institute of Science and Technology (UNIST), Room 701-4, 2nd Engineering Building (104), 50 UNIST-gil, Eonyang-eup, Ulju-gun, Ulsan 44919, Republic of Korea.
| | - Oh-Hoon Kwon
- Department of Chemistry, College of Natural Sciences, Ulsan National Institute of Science and Technology (UNIST), Room 415, Advanced Material Research Building (103), 50 UNIST-gil, Eonyang-eup, Ulju-gun, Ulsan 44919, Republic of Korea. .,Center for Soft and Living Matter, Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
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12
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Wang GD, Liu ZX, Qiu BB, Zhang ZG, Wang R, Wang XY, Ma J, Li YF, Xiao M, Zhang CF. Ultrafast electron transfer in all-small-molecule photovoltaic blends promoted by intermolecular interactions in cyanided donors. CHINESE J CHEM PHYS 2021. [DOI: 10.1063/1674-0068/cjcp2109179] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Guo-dong Wang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Zhi-xing Liu
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Bei-bei Qiu
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Zhi-guo Zhang
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- State key Laboratory of Chemical Resource Engineering, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Rui Wang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Xiao-yong Wang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Jing Ma
- Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Yong-fang Li
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, 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, USA
| | - Chun-feng Zhang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing 210093, China
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13
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Liu Y, Li B, Xiang Z. Pathways towards Boosting Solar-Driven Hydrogen Evolution of Conjugated Polymers. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2007576. [PMID: 34160904 DOI: 10.1002/smll.202007576] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 01/16/2021] [Indexed: 06/13/2023]
Abstract
Photocatalytic H2 evolution under solar illumination has been considered to be a promising technology for green energy resources. Developing highly efficient photocatalysts for photocatalytic water splitting is long-term desired but still challenging. Conjugated polymers (CPs) have attracted ongoing attention and have been considered to be promising alternatives for solar-driven H2 production due to the excellent merits of the large π-conjugated system, versatile structures, tunable photoelectric properties, and well-defined chemical composites. The excellent merits have offered numerous methods for boosting photocatalytic hydrogen evolution (PHE) of initial CP-based photocatalysts, whose apparent quantum yield is dramatically increased from <1 to >20% in recent five years. According to the photocatalytic mechanism, this review herein systematically summarizes three major strategies for boosting photocatalytic H2 production of CPs: 1) enhancing visible light absorption, 2) suppressing recombination of electron-hole pairs, and 3) boosting surface catalytic reaction, mainly involving eleven methods, that is, copolymerization, modifying cross-linker, constructing a donor-acceptor structure, functionalization, fabricating organic heterojunction, loading cocatalyst, and surface modification. Finally, the perspectives towards the future development of PHE are proposed.
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Affiliation(s)
- Yaoyao Liu
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
| | - Bingjie Li
- The First Affiliated Hospital Zhengzhou University, 1 Jianshe Street, Zhengzhou, Henan, 450052, P. R. China
| | - Zhonghua Xiang
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
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14
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Kim W, Tahara S, Kuramochi H, Takeuchi S, Kim T, Tahara T, Kim D. Mode‐Specific Vibrational Analysis of Exciton Delocalization and Structural Dynamics in Conjugated Oligomers. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202102168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Woojae Kim
- Department of Chemistry, Spectroscopy Laboratory for Functional, π-Electronic Systems Yonsei University Seoul 03722 Korea
- Current address: Department of Chemistry and Chemical Biology Cornell University Ithaca NY 14853 USA
| | - Shinya Tahara
- Molecular Spectroscopy Laboratory RIKEN 2-1 Hirosawa Wako 351-0198 Japan
- Current address: Graduate School of Pharmaceutical Sciences Tohoku University 6-3 Aramaki-aza-Aoba, Aoba-ku Sendai 980-8578 Japan
| | - Hikaru Kuramochi
- Molecular Spectroscopy Laboratory RIKEN 2-1 Hirosawa Wako 351-0198 Japan
- Ultrafast Spectroscopy Research Team RIKEN Center for Advanced Photonics (RAP) 2-1 Hirosawa Wako 351-0198 Japan
- JST PRESTO 4-1-8 Honcho Kawaguchi 332-0012 Japan
- Current address: Research Center of Integrative Molecular Systems (CIMoS) Institute for Molecular Science 38 Nishigo-Naka, Myodaji Okazaki 444-8585 Japan
| | - Satoshi Takeuchi
- Molecular Spectroscopy Laboratory RIKEN 2-1 Hirosawa Wako 351-0198 Japan
- Ultrafast Spectroscopy Research Team RIKEN Center for Advanced Photonics (RAP) 2-1 Hirosawa Wako 351-0198 Japan
- Current address: Graduate School of Material Science University of Hyogo 3-2-1 Koto Kamigori Ako 678-1297 Japan
| | - Taeyeon Kim
- Department of Chemistry, Spectroscopy Laboratory for Functional, π-Electronic Systems Yonsei University Seoul 03722 Korea
- Current address: Department of Chemistry and Institute for Sustainability and Energy at Northwestern Northwestern University Evanston IL 60208-3113 USA
| | - Tahei Tahara
- Molecular Spectroscopy Laboratory RIKEN 2-1 Hirosawa Wako 351-0198 Japan
- Ultrafast Spectroscopy Research Team RIKEN Center for Advanced Photonics (RAP) 2-1 Hirosawa Wako 351-0198 Japan
| | - Dongho Kim
- Department of Chemistry, Spectroscopy Laboratory for Functional, π-Electronic Systems Yonsei University Seoul 03722 Korea
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15
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Wang K, Chen H, Li S, Zhang J, Zou Y, Yang Y. Interplay between Intrachain and Interchain Excited States in Donor-Acceptor Copolymers. J Phys Chem B 2021; 125:7470-7476. [PMID: 34219460 DOI: 10.1021/acs.jpcb.1c03989] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Recently, rapid progress in the power conversion efficiency for organic solar cells (OSCs) is achieved due to the phenomenal development of the nonfullerene electron acceptors. In addition to the pairing electron donors, conjugated donor-acceptor copolymers are another key player in the high-efficiency OSCs. Here, the temporal evolution of excited states in a typical copolymer, PM6, was traced by transient absorption spectroscopy. The spectroscopic result implies the formation of two kinetically correlated intrachain species, polaron excitons and intrachain polaron pairs. In the presence of the interchain interaction, these intrachain species quickly convert into interchain polaron pairs on a time scale of few picoseconds. Our findings reveal that the electron transfer mechanisms in PM6-based OSCs substantially depend on the PM6 environment in the bulk heterojunction blends.
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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
| | - Honggang Chen
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China
| | - Shuangyuan Li
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Jinzhong Zhang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, 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
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16
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Kim W, Tahara S, Kuramochi H, Takeuchi S, Kim T, Tahara T, Kim D. Mode-Specific Vibrational Analysis of Exciton Delocalization and Structural Dynamics in Conjugated Oligomers. Angew Chem Int Ed Engl 2021; 60:16999-17008. [PMID: 33730430 DOI: 10.1002/anie.202102168] [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: 02/10/2021] [Indexed: 11/09/2022]
Abstract
Exciton delocalization in organic semiconducting polymers, affected by structures at a molecular level, plays a crucial role in modulating relaxation pathways, such as charge generation and singlet fission, which can boost device efficiency. However, the structural diversity of polymers and broad signals from typical electronic spectroscopy have their limits when it comes to revealing the interplay between local structures and exciton delocalization. To tackle these problems, we apply femtosecond stimulated Raman spectroscopy in archetypical conjugated oligothiophenes with different chain lengths. We observed Raman frequency dispersions of symmetric bond stretching modes and mode-specific kinetics in the S1 Raman spectra, which underpins the subtle and complex interplay between exciton delocalization and bond length alternation along the conjugation coordinate. Our results provide a more general picture of exciton delocalization in the context of molecular structures for conjugated materials.
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Affiliation(s)
- Woojae Kim
- Department of Chemistry, Spectroscopy Laboratory for Functional, π-Electronic Systems, Yonsei University, Seoul, 03722, Korea.,Current address: Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, 14853, USA
| | - Shinya Tahara
- Molecular Spectroscopy Laboratory, RIKEN, 2-1 Hirosawa, Wako, 351-0198, Japan.,Current address: Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aramaki-aza-Aoba, Aoba-ku, Sendai, 980-8578, Japan
| | - Hikaru Kuramochi
- Molecular Spectroscopy Laboratory, RIKEN, 2-1 Hirosawa, Wako, 351-0198, Japan.,Ultrafast Spectroscopy Research Team, RIKEN Center for Advanced Photonics (RAP), 2-1 Hirosawa, Wako, 351-0198, Japan.,JST PRESTO, 4-1-8 Honcho, Kawaguchi, 332-0012, Japan.,Current address: Research Center of Integrative Molecular Systems (CIMoS), Institute for Molecular Science, 38 Nishigo-Naka, Myodaji, Okazaki, 444-8585, Japan
| | - Satoshi Takeuchi
- Molecular Spectroscopy Laboratory, RIKEN, 2-1 Hirosawa, Wako, 351-0198, Japan.,Ultrafast Spectroscopy Research Team, RIKEN Center for Advanced Photonics (RAP), 2-1 Hirosawa, Wako, 351-0198, Japan.,Current address: Graduate School of Material Science, University of Hyogo, 3-2-1 Koto, Kamigori, Ako, 678-1297, Japan
| | - Taeyeon Kim
- Department of Chemistry, Spectroscopy Laboratory for Functional, π-Electronic Systems, Yonsei University, Seoul, 03722, Korea.,Current address: Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, IL, 60208-3113, USA
| | - Tahei Tahara
- Molecular Spectroscopy Laboratory, RIKEN, 2-1 Hirosawa, Wako, 351-0198, Japan.,Ultrafast Spectroscopy Research Team, RIKEN Center for Advanced Photonics (RAP), 2-1 Hirosawa, Wako, 351-0198, Japan
| | - Dongho Kim
- Department of Chemistry, Spectroscopy Laboratory for Functional, π-Electronic Systems, Yonsei University, Seoul, 03722, Korea
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17
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Tegegne NA, Abdissa Z, Mammo W. Photophysical, Thermal and Structural Properties of Thiophene and Benzodithiophene-Based Copolymers Synthesized by Direct Arylation Polycondensation Method. Polymers (Basel) 2021; 13:1151. [PMID: 33916513 PMCID: PMC8038498 DOI: 10.3390/polym13071151] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 03/19/2021] [Accepted: 03/22/2021] [Indexed: 11/16/2022] Open
Abstract
Three low-band-gap copolymers based on isoindigo acceptor units were designed and successfully synthesized by direct arylation polycondensation method. Two of them were benzodithiophene (BDT)-isoindigo copolymers (PBDTI-OD and PBDTI-DT) with 2-octlydodecyl (OD) and 2-decyltetradecyl (DT) substituted isoindigo units, respectively. Thiophene donor and DT-substituted isoindigo acceptor units were copolymerized to synthesize PTI-DT. The copolymers have a broad absorption range that extends to over 760 nm with a band gap ≈1.5 eV. The photophysical property studies showed that the BDT-based copolymers have non-polar ground states. Their emission exhibited the population of the intramolecular charge transfer (ICT) state in polar solvents and tightly bound excitonic state in non-polar solvents due to self-aggregation. On the contrary, the emission from the thiophene-based copolymers was only from the tightly bound excitonic state. The thermal decomposition temperature of the copolymers was above 380 °C. The X-ray diffraction pattern of the three copolymers showed a halo due to π-π stacking. A second, sharper peak was observed in the BDT-based copolymer with a longer side chain on the isoindigo unit (PBDTI-DT), and the thiophene-based copolymers with PTI-DT, exhibiting a better structural order.
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Affiliation(s)
| | - Zelalem Abdissa
- Department of Chemistry, Addis Ababa University, Addis Ababa P.O. Box 1176, Ethiopia; (Z.A.); (W.M.)
| | - Wendimagegn Mammo
- Department of Chemistry, Addis Ababa University, Addis Ababa P.O. Box 1176, Ethiopia; (Z.A.); (W.M.)
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18
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Jiao Z, Jiang T, Zhou Z, Qin C, Long J, Liu Y, Jiang Y. Identification of a bridge-specific intramolecular exciton dissociation pathway in donor-π-acceptor alternating conjugated polymers. NANOSCALE RESEARCH LETTERS 2021; 16:51. [PMID: 33745078 PMCID: PMC7981365 DOI: 10.1186/s11671-021-03507-0] [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: 10/23/2020] [Accepted: 03/12/2021] [Indexed: 06/12/2023]
Abstract
Intramolecular exciton dissociation is critical for high efficient mobile charge carrier generations in organic solar cells. Yet despite much attention, the effects of π bridges on exciton dissociation dynamics in donor-π-acceptor (D-π-A) alternating conjugated polymers remain still unclear. Here, using a combination of femtosecond time-resolved transient absorption (TA) spectroscopy and steady-state spectroscopy, we track ultrafast intramolecular exciton relaxation dynamics in three D-π-A alternating conjugated polymers which were synthesized by Qin's group and named HSD-A, HSD-B, HSD-C. It is found that the addition of thiophene unit as π bridges will lead to the red shift of steady-state absorption spectrum. Importantly, we reveal the existence of a new intramolecular exciton dissociation pathway mediated by a bridge-specific charge transfer (CT') state with the TA fingerprint peak at 1200 nm in π-bridged HSD-B and HSD-C. This CT' state results in higher electron capture rates for HSD-B and HSD-C as compared to HSD-A. Depending on the proportion of CT' state and nongeminate recombination are important step for the understanding of high power conversion efficiencies in HSD-B than in HSD-C. We propose that this bridge-specific exciton dissociation pathway plays an important role in ultrafast intramolecular exciton dissociation of organic photovoltaic material D-π-A alternating conjugated polymers.
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Affiliation(s)
- Zhaoyong Jiao
- Henan Key Laboratory of Infrared Materials and Spectrum Measures and Applications, School of Physics, Henan Normal University, Xinxiang, 453007, People's Republic of China
| | - Tingting Jiang
- Henan Key Laboratory of Infrared Materials and Spectrum Measures and Applications, School of Physics, Henan Normal University, Xinxiang, 453007, People's Republic of China
| | - Zhongpo Zhou
- Henan Key Laboratory of Infrared Materials and Spectrum Measures and Applications, School of Physics, Henan Normal University, Xinxiang, 453007, People's Republic of China
| | - Chaochao Qin
- Henan Key Laboratory of Infrared Materials and Spectrum Measures and Applications, School of Physics, Henan Normal University, Xinxiang, 453007, People's Republic of China.
| | - Jinyou Long
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan, 430071, People's Republic of China.
| | - Yufang Liu
- Henan Key Laboratory of Infrared Materials and Spectrum Measures and Applications, School of Physics, Henan Normal University, Xinxiang, 453007, People's Republic of China
| | - Yuhai Jiang
- Henan Key Laboratory of Infrared Materials and Spectrum Measures and Applications, School of Physics, Henan Normal University, Xinxiang, 453007, People's Republic of China.
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201210, People's Republic of China.
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19
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Nakamura T. Excitation Energy Transfer Dynamics in a Low-Band-Gap Copolymer: Two-Dimensional Electronic Spectroscopy of PTB7 in Solution. Macromolecules 2020. [DOI: 10.1021/acs.macromol.0c01118] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Takumi Nakamura
- Analysis Technology Center, Research and Development Management Headquarters, FUJIFILM Corporation, 210 Nakanuma, Minamiashigara 251-0193, Japan
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20
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Keshtov ML, Kuklin SA, Dou C, Koukaras EN, Singhal R, Malhotra P, Sharma GD. Enhancement of photovoltaic efficiency through fine adjustment of indacene‐based non‐fullerene acceptor by minimal chlorination for polymer solar cells. NANO SELECT 2020. [DOI: 10.1002/nano.202000027] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Mukhamed L. Keshtov
- Institute of Organoelement Compounds of the Russian Academy of Sciences Moscow 119991 Russian Federation
| | - Sergei A. Kuklin
- Institute of Organoelement Compounds of the Russian Academy of Sciences Moscow 119991 Russian Federation
| | - Chuandong Dou
- Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 China
| | - Emmanuel N. Koukaras
- Laboratory of Quantum and Computational Chemistry Department of Chemistry Aristotle University of Thessaloniki Thessaloniki GR‐54124 Greece
| | - Rahul Singhal
- Department of Physics Malviya National Institute of Technology Jaipur Rajasthan 302017 India
| | - Prateek Malhotra
- Department of Physics The LNM Institute for Information Technology Jaipur Rajasthan 302017 India
| | - Ganesh D. Sharma
- Department of Physics The LNM Institute for Information Technology Jaipur Rajasthan 302017 India
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21
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Leonard AA, Mosquera MA, Jones LO, Cai Z, Fauvell TJ, Kirschner MS, Gosztola DJ, Schatz GC, Schaller RD, Yu L, Chen LX. Photophysical implications of ring fusion, linker length, and twisting angle in a series of perylenediimide-thienoacene dimers. Chem Sci 2020; 11:7133-7143. [PMID: 33209244 PMCID: PMC7654190 DOI: 10.1039/d0sc02862b] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 06/17/2020] [Indexed: 01/05/2023] Open
Abstract
Perylenediimide (PDI) derivatives have been widely studied as electron acceptor alternatives to fullerenes in organic photovoltaics (OPVs) because of their tunable absorption in the visible range, inexpensive synthesis, and photochemical stability. A common motif for improving device efficiency involves joining multiple PDIs together through electron-rich linkers to form a twisted acceptor-donor-acceptor molecule. Molecular features such as ring fusion are further employed to modify the structure locally and in films. These synthetic efforts have greatly enhanced OPV device efficiencies, however it remains unclear how the increasingly elaborate structural modifications affect the photophysical processes integral to efficient photon-to-charge conversion. Here we carry out a systematic study of a series of PDI dimers with thienoacene linkers in which the twist angle, linker length, and degree of ring fusion are varied to investigate the effects of these structural features on the molecular excited states and exciton recombination dynamics. Spectroscopic characterization of the dimers suggest that ring fusion causes greater coupling between the donor and acceptor components and greatly enhances the lifetime of a thienoacene to PDI charge transfer state. The lifetime of this CT state also correlates well with the linker-PDI dihedral angle, with smaller dihedral angle resulting in longer lifetime. DFT and two-photon absorption TDDFT calculations were developed in-house to model the ground state and excited transitions, providing theoretical insight into the reasons for the observed photophysical properties and identifying the charge transfer state in the excited state absorption spectra. These results highlight how the longevity of the excited state species, important for the efficient conversion of excitons to free carriers in OPV devices, can be chemically tuned by controlling ring fusion and by using steric effects to control the relative orientations of the molecular fragments. The results provide a successful rationalization of the behavior of solar cells involving these acceptor molecules.
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Affiliation(s)
- Ariel A Leonard
- Department of Chemistry , Northwestern University , 2145 Sheridan Road , Evanston , Illinois 60208 , USA .
| | - Martín A Mosquera
- Department of Chemistry , Northwestern University , 2145 Sheridan Road , Evanston , Illinois 60208 , USA .
| | - Leighton O Jones
- Department of Chemistry , Northwestern University , 2145 Sheridan Road , Evanston , Illinois 60208 , USA .
| | - Zhengxu Cai
- Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications , School of Materials Science & Engineering , Beijing Institute of Technology , Beijing 100081 , China
| | - Thomas J Fauvell
- Department of Chemistry , Northwestern University , 2145 Sheridan Road , Evanston , Illinois 60208 , USA .
| | - Matthew S Kirschner
- Department of Chemistry , Northwestern University , 2145 Sheridan Road , Evanston , Illinois 60208 , USA .
| | - David J Gosztola
- Center for Nanoscale Materials , Argonne National Laboratory , 9700 South Cass Avenue Lemont , Illinois 60439 , USA
| | - George C Schatz
- Department of Chemistry , Northwestern University , 2145 Sheridan Road , Evanston , Illinois 60208 , USA .
| | - Richard D Schaller
- Department of Chemistry , Northwestern University , 2145 Sheridan Road , Evanston , Illinois 60208 , USA .
- Center for Nanoscale Materials , Argonne National Laboratory , 9700 South Cass Avenue Lemont , Illinois 60439 , USA
| | - Luping Yu
- Department of Chemistry and James Frank Institute , The University of Chicago , 929 East 57th Street , Chicago , Illinois 60637 , USA
| | - Lin X Chen
- Department of Chemistry , Northwestern University , 2145 Sheridan Road , Evanston , Illinois 60208 , USA .
- Chemical Sciences and Engineering Division , Argonne National Laboratory , 9700 South Cass Avenue, Lemont , Illinois 60439 , USA .
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22
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Wang R, Zhang C, Li Q, Zhang Z, Wang X, Xiao M. Charge Separation from an Intra-Moiety Intermediate State in the High-Performance PM6:Y6 Organic Photovoltaic Blend. J Am Chem Soc 2020; 142:12751-12759. [DOI: 10.1021/jacs.0c04890] [Citation(s) in RCA: 122] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Rui Wang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Chunfeng Zhang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Qian Li
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Zhiguo Zhang
- College of Materials 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
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23
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Abstract
AbstractPhotoinduced charge generation forms the physical basis for energy conversion in organic photovoltaic (OPV) technology. The fundamental initial steps involved are absorption of light by organic semiconductors (generally π-conjugated polymers) to generate photoexcited states (Frenkel excitons) followed by charge transfer and charge separation processes in presence of suitable acceptor. The absorbed photon energy must be utilized completely for achieving maximum device efficiency. However progressive relaxation losses of instantaneously generated high-energy or hot-excited states form major bottleneck for maximum derivable voltage. This efficiency limiting factor has been challenged recently by the role of hot-carriers in efficient generation of charges. Therefore tailoring the dissociation of hot-exciton to be temporally faster than all relaxation processes could minimize the energy loss pathways. Implementation of this concept of hot-carrier photovoltaics demands critical understanding of molecular parameters that circumvent all energy relaxation processes and favor hot-carrier generation. In my dissertation work, I have examined the fate of photo-generated excitons in the context of polymer backbone and morphology, and therefore obtain a fundamental structure-function correlation in organic semiconductors.
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Affiliation(s)
- Palas Roy
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai-400005, India
- School of Chemistry, University of East Anglia, Norwich NR4 7TJ, UK
| | - Jyotishman Dasgupta
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai-400005, India
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24
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Effects of Intra- and Interchain Interactions on Exciton Dynamics of PTB7 Revealed by Model Oligomers. Molecules 2020; 25:molecules25102441. [PMID: 32456192 PMCID: PMC7287679 DOI: 10.3390/molecules25102441] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 05/16/2020] [Accepted: 05/22/2020] [Indexed: 11/28/2022] Open
Abstract
Recent studies have shown that molecular aggregation structures in precursor solutions of organic photovoltaic (OPV) polymers have substantial influence on polymer film morphology, exciton and charge carrier transport dynamics, and hence, the resultant device performance. To distinguish photophysical impacts due to increasing π-conjugation from chain lengthening and π–π stacking from single/multi chain aggregation in solution and film, we used oligomers of a well-studied charge transfer polymer PTB7 with different lengths as models to reveal intrinsic photophysical properties of a conjugated segment in the absence of inter-segment aggregation. In comparison with previously studied photophysical properties in polymeric PTB7, we found that oligomer dynamics are dominated by a process of planarization of the conjugated backbone into a quinoidal structure that resembles the self-folded polymer and that, when its emission is isolated, this quinoidal excited state resembling the planar polymer chain exhibits substantial charge transfer character via solvent-dependent emission shifts. Furthermore, the oligomers distinctly lack the long-lived charge separated species characteristic of PTB7, suggesting that the progression from charge transfer character in isolated chains to exciton splitting in neat polymer solution is modulated by the interchain interactions enabled by self-folding.
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25
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Chen Z, Chen X, Qiu B, Zhou G, Jia Z, Tao W, Li Y, Yang YM, Zhu H. Ultrafast Hole Transfer and Carrier Transport Controlled by Nanoscale-Phase Morphology in Nonfullerene Organic Solar Cells. J Phys Chem Lett 2020; 11:3226-3233. [PMID: 32259443 DOI: 10.1021/acs.jpclett.0c00919] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Nonfullerene acceptors (NFAs) have attracted great attention in high-efficiency organic solar cells (OSCs). While the effect of molecular properties including structures and energetics on charge transfer has been extensively investigated, the effect of macroscopic-phase properties is yet to be revealed. Here we have performed a correlation study of the nanoscale-phase morphology on the photoexcited hole transfer (HT) process and photovoltaic performance by combining ultrafast spectroscopy with high temporal resolution and photo-induced force microscopy (PiFM) with high spatial and chemical resolution. In PM6/IT-4F, we observe biphasic HT behavior with a minor ultrafast (<100 fs) interfacial process and a major diffusion-mediated HT process until ∼100 ps, which depends strongly on phase segregation. Because of the interplay between charge transfer and transport, a compromised domain size of 20-30 nm for NFAs shows the best performance. This study highlights the critical role of phase morphology in high-efficiency OSCs.
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Affiliation(s)
| | | | - Beibei Qiu
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, 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
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26
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Aslan E, Karaman M, Yanalak G, Bilgili H, Can M, Ozel F, Patir IH. Synthesis of novel tetrazine based D-π-A organic dyes for photoelectrochemical and photocatalytic hydrogen evolution. J Photochem Photobiol A Chem 2020. [DOI: 10.1016/j.jphotochem.2019.112301] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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27
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Gallastegui A, Spada RM, Cagnetta G, Ponzio RA, Martínez SR, Previtali CM, Gómez ML, Palacios RE, Chesta CA. Conjugated Polymer Nanoparticles as Unique Coinitiator-Free, Water-Soluble, Visible-Light Photoinitiators of Vinyl Polymerization. Macromol Rapid Commun 2020; 41:e1900601. [PMID: 32053268 DOI: 10.1002/marc.201900601] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 01/09/2020] [Indexed: 12/13/2022]
Abstract
The use of conjugated polymer nanoparticles (CP NPs) of poly(9,9-dioctylfluorene-alt-benzothiadiazole) and poly(9,9-di-n-octylfluorenyl-2,7-diyl) as efficient photoinitiator systems (PIS) of vinyl polymerization in water is reported herein. CP NPs are biocompatible, excitable with blue commercial LEDs and, unlike visible light Type II PIS, do not need co-initiators to trigger a monomer chain reaction. CP NPs photoinitiate polymerization of a variety of acrylic monomers with initiation rates comparable to those observed for well-known Type II PIS. Given the extraordinarily large molar absorption coefficients of CP NPs (≈108 m-1 cm-1 ) very low particle concentration is required for effective polymerization. Additionally, CP NPs behave as conventional macrophotoinitiators significantly reducing contamination risks due to leaching of low molecular weight byproducts. These combined features make CP NPs PIS suitable to synthesize polymeric materials for many healthcare and biomedical applications including drug delivery, tissue engineering, prosthetic implants, and food/medicine packaging. These CP NPs PIS are also used to synthesize nano-hydrogels with a relatively narrow and controlled size distribution in the absence of surfactants. It is proposed that polymerization is initiated at the CP NPs surface by photogenerated free polarons, in close analogy to the mechanism previously described for PIS based on inorganic semiconductor NPs.
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Affiliation(s)
- Antonela Gallastegui
- Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados (IITEMA), Universidad Nacional de Río Cuarto (UNRC) and Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Campus Universitario, 5800, Río Cuarto, Argentina
| | - Ramiro M Spada
- Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados (IITEMA), Universidad Nacional de Río Cuarto (UNRC) and Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Campus Universitario, 5800, Río Cuarto, Argentina
| | - Gonzalo Cagnetta
- Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados (IITEMA), Universidad Nacional de Río Cuarto (UNRC) and Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Campus Universitario, 5800, Río Cuarto, Argentina
| | - Rodrigo A Ponzio
- Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados (IITEMA), Universidad Nacional de Río Cuarto (UNRC) and Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Campus Universitario, 5800, Río Cuarto, Argentina
| | - Sol R Martínez
- Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados (IITEMA), Universidad Nacional de Río Cuarto (UNRC) and Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Campus Universitario, 5800, Río Cuarto, Argentina
| | - Carlos M Previtali
- Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados (IITEMA), Universidad Nacional de Río Cuarto (UNRC) and Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Campus Universitario, 5800, Río Cuarto, Argentina
| | - María Lorena Gómez
- Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados (IITEMA), Universidad Nacional de Río Cuarto (UNRC) and Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Campus Universitario, 5800, Río Cuarto, Argentina
| | - Rodrigo E Palacios
- Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados (IITEMA), Universidad Nacional de Río Cuarto (UNRC) and Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Campus Universitario, 5800, Río Cuarto, Argentina
| | - Carlos A Chesta
- Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados (IITEMA), Universidad Nacional de Río Cuarto (UNRC) and Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Campus Universitario, 5800, Río Cuarto, Argentina
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28
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Keshtov ML, Kuklin SA, Konstantinov IO, Khokhlov AR, Xie Z, Dou C, Koukaras EN, Suthar R, Sharma GD. Synthesis and Photovoltaic Properties of New Conjugated D‐A Polymers Based on the Same Fluoro‐Benzothiadiazole Acceptor Unit and Different Donor Units. ChemistrySelect 2020. [DOI: 10.1002/slct.201904353] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Mukhaned L Keshtov
- Institute of Organoelement Compounds of the Russian Academy of Sciences Vavilova St., 28 119991 Moscow Russian Federation
| | - Serge. A. Kuklin
- Institute of Organoelement Compounds of the Russian Academy of Sciences Vavilova St., 28 119991 Moscow Russian Federation
| | - Igor O. Konstantinov
- Institute of Organoelement Compounds of the Russian Academy of Sciences Vavilova St., 28 119991 Moscow Russian Federation
| | - Alexei R. Khokhlov
- Department of Physics of Polymers and Crystals, Faculty of Physics M.V. Lomonosov Moscow State University Leninskie Gory 1 119991 Moscow Russia
| | - Zhiyuan Xie
- Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 China
| | - Chuandong Dou
- Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 China
| | - Emmanuel N. Koukaras
- Laboratory of Quantum and Computational Chemistry, Department of Chemistry Aristotle University of Thessaloniki, GR- 54124 Thessaloniki Greece
| | - Rakesh Suthar
- Department of Physics The LNM Institute for Information Technology, Jamdoli, Jaipur 302031, India
| | - Ganesh D. Sharma
- Department of Physics The LNM Institute for Information Technology, Jamdoli, Jaipur 302031, India
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29
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Kim HS, Song CE, Ha JW, Lee S, Rasool S, Lee HK, Shin WS, Hwang DH. Synthesis of ITIC Derivatives with Extended π-Conjugation as Non-Fullerene Acceptors for Organic Solar Cells. ACS APPLIED MATERIALS & INTERFACES 2019; 11:47121-47130. [PMID: 31755688 DOI: 10.1021/acsami.9b15247] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The realization of printed organic solar cells (OSCs) as a commercial technology is dependent on the development of high-performance photovoltaic materials suitable for large-scale device manufacture. In this study, the design, synthesis, and characterization of a series of A-D-A'-D-A-type molecular acceptors based on indacenodithienothiophene (IDTT) and thiophene-flanked 2,1,3-benzothiadiazole (DTBT) are reported. The synthesized molecular acceptors showed broader absorption ranges and narrower band gap energies than those of well-known 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)-based molecular acceptors. Furthermore, the synthesized acceptors could tune the frontier molecular orbital energy levels, dipole moments, and their crystallinities by introducing fluorine (F) atoms and cyano (CN) groups on DTBT as a core A' unit. The cyano-substituted DTBT-based molecular acceptor (CNDTBT-IDTT-FINCN) showed a strong molar absorptivity and dipole moment, high hole/electron charge mobilities, and a favorable face-on orientation using films blended with 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). An inverted organic photovoltaic (OPV) device using CNDTBT-IDTT-FINCN exhibits a power conversion efficiency (PCE) of 9.13% when using PBDB-T as a donor material in small cells (0.12 cm2). Sub-module devices with an active area of 55.45 cm2 are fabricated using bar-coating and exhibit PCEs of up to 7.50%. This demonstration of a high-efficiency large-area device makes CNDTBT-IDTT-FINCN a suitable and promising candidate for printed OPV devices.
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Affiliation(s)
- Hee Su Kim
- Department of Chemistry and Chemistry Institute for Functional Materials , Pusan National University , Busan 46241 , Republic of Korea
| | - Chang Eun Song
- Energy Materials Research Center , Korea Research Institute of Chemical Technology (KRICT) , Daejeon 34114 , Republic of Korea
| | - Jong-Woon Ha
- Department of Chemistry and Chemistry Institute for Functional Materials , Pusan National University , Busan 46241 , Republic of Korea
| | - Suha Lee
- Department of Chemistry and Chemistry Institute for Functional Materials , Pusan National University , Busan 46241 , Republic of Korea
| | - Shafket Rasool
- Energy Materials Research Center , Korea Research Institute of Chemical Technology (KRICT) , Daejeon 34114 , Republic of Korea
| | - Hang Ken Lee
- Energy Materials Research Center , Korea Research Institute of Chemical Technology (KRICT) , Daejeon 34114 , Republic of Korea
| | - Won Suk Shin
- Energy Materials Research Center , Korea Research Institute of Chemical Technology (KRICT) , Daejeon 34114 , Republic of Korea
| | - Do-Hoon Hwang
- Department of Chemistry and Chemistry Institute for Functional Materials , Pusan National University , Busan 46241 , Republic of Korea
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30
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Zhao Y, Zhao S, Wang L, Zhou Z, Liu J, Min T, Peng B, Hu Z, Jin S, Liu M. Sunlight Control of Interfacial Magnetism for Solar Driven Spintronic Applications. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2019; 6:1901994. [PMID: 31871867 PMCID: PMC6918118 DOI: 10.1002/advs.201901994] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 09/11/2019] [Indexed: 06/10/2023]
Abstract
The inexorable trend of next generation spintronics is to develop smaller, lighter, faster, and more energy efficient devices. Ultimately, spintronics driven by free energy, for example, solar power, is imperative. Here, a prototype photovoltaic spintronic device with an optical-magneto-electric tricoupled photovoltaic/magnetic thin film heterojunction, where magnetism can be manipulated directly by sunlight via interfacial effect, is proposed. The magnetic anisotropy is reduced evidenced by the out-of-plane ferromagnetic resonance (FMR) field change of 640.26 Oe under 150 mW cm-2 illumination via in situ electron spin resonance (ESR) method. The transient absorption analysis and the first-principles calculation reveal that the photovoltaic electrons doping in the cobalt film alter the band filling of this ferromagnetic film. The findings provide a new path of electron doping control magnetism and demonstrate an optical-magnetic dual controllable logical switch with limited energy supply, which may further transform the landscape of spintronics research.
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Affiliation(s)
- Yifan Zhao
- Electronic Materials Research LaboratoryKey Laboratory of the Ministry of Education and International Center for Dielectric ResearchSchool of Electronic and Information Engineering and State Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
- International Joint Laboratory for Micro/Nano Manufacture and Measurement TechnologyXi'an Jiaotong UniversityXi'an710049China
| | - Shishun Zhao
- Electronic Materials Research LaboratoryKey Laboratory of the Ministry of Education and International Center for Dielectric ResearchSchool of Electronic and Information Engineering and State Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
| | - Lei Wang
- Center for Spintronics and Quantum SystemState Key Laboratory for Mechanical Behavior of MaterialsSchool of Materials Science and EngineeringXi'an Jiaotong UniversityXi'anShaanxi710049China
| | - Ziyao Zhou
- Electronic Materials Research LaboratoryKey Laboratory of the Ministry of Education and International Center for Dielectric ResearchSchool of Electronic and Information Engineering and State Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
| | - Junxue Liu
- State Key Laboratory of Molecular Reaction Dynamics and Collaborative Innovation Center of Chemistry for Energy Materials (iChEM)Dalian Institute of Chemical PhysicsChinese Academy of Sciences457 Zhongshan Rd.Dalian116023China
| | - Tai Min
- Center for Spintronics and Quantum SystemState Key Laboratory for Mechanical Behavior of MaterialsSchool of Materials Science and EngineeringXi'an Jiaotong UniversityXi'anShaanxi710049China
| | - Bin Peng
- Electronic Materials Research LaboratoryKey Laboratory of the Ministry of Education and International Center for Dielectric ResearchSchool of Electronic and Information Engineering and State Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
| | - Zhongqiang Hu
- Electronic Materials Research LaboratoryKey Laboratory of the Ministry of Education and International Center for Dielectric ResearchSchool of Electronic and Information Engineering and State Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
| | - Shengye Jin
- State Key Laboratory of Molecular Reaction Dynamics and Collaborative Innovation Center of Chemistry for Energy Materials (iChEM)Dalian Institute of Chemical PhysicsChinese Academy of Sciences457 Zhongshan Rd.Dalian116023China
| | - Ming Liu
- Electronic Materials Research LaboratoryKey Laboratory of the Ministry of Education and International Center for Dielectric ResearchSchool of Electronic and Information Engineering and State Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
- International Joint Laboratory for Micro/Nano Manufacture and Measurement TechnologyXi'an Jiaotong UniversityXi'an710049China
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31
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Sahu H, Ma H. Unraveling Correlations between Molecular Properties and Device Parameters of Organic Solar Cells Using Machine Learning. J Phys Chem Lett 2019; 10:7277-7284. [PMID: 31702163 DOI: 10.1021/acs.jpclett.9b02772] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Understanding the relationships between molecular properties and device parameters is highly desired not only to improve the overall performance of an organic solar cell but also to fulfill the requirements of a device for a particular application such as solar-to-fuel energy conversion (high open-circuit voltage (VOC)) or solar window applications (high short circuit current (JSC)). In this work, a series of machine learning models are built for three important device characteristics (VOC, JSC, and fill factor) using 13 crucial molecular properties as descriptors, resulting in an impressive predictive performance (r = 0.7). These models may play a vital role in designing promising organic materials for a specific photovoltaic application with high VOC/JSC. The importance of descriptors for each device parameter is unraveled, which may assist in tuning them and improve understanding of the energy conversion process.
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Affiliation(s)
- Harikrishna Sahu
- Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering , Nanjing University , Nanjing 210023 , China
| | - Haibo Ma
- Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering , Nanjing University , Nanjing 210023 , China
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32
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Qin R, Guo D, Ma H, Yang J, Jiang Y, Liu H, Liu Z, Song J, Qin C. Effect of Molecular Structures of Donor Monomers of Polymers on Photovoltaic Properties. ACS OMEGA 2019; 4:19177-19182. [PMID: 31763541 PMCID: PMC6868602 DOI: 10.1021/acsomega.9b02476] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Accepted: 10/22/2019] [Indexed: 05/04/2023]
Abstract
This work investigates the photovoltaic properties of polymers that include different carbazole blocks as electron donors (D) but the same benzothiadiazole derivative as the electron acceptor (A). Five D-A copolymers are studied with ultrafast intramolecular exciton splitting and recombination dynamics to acquire the single-molecule structure and their photovoltaic performance relationship. The photovoltaic parameters such as energy level, optical band gap, and light-harvesting ability are highly dependent on the molecular structure of the donor monomer (including their appended flexible alkyl chain). Branched or linear alkyl groups on the same D block obviously vary the polymer steady-state absorption spectra and film morphology. For organic solar cells, this work allows tuning and control of the ultrafast dynamics, implying photovoltaic material design in the future.
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Affiliation(s)
- Ruiping Qin
- Key
Laboratory of Photovoltaic Materials of Henan Province, School
of Material Science and Engineering, Key Laboratory of Photovoltaic
Materials of Henan Province, School of Physics, and School of Physics, Henan Normal University, Xinxiang 453007, China
- E-mail: (R.Q.)
| | - Deen Guo
- Key
Laboratory of Photovoltaic Materials of Henan Province, School
of Material Science and Engineering, Key Laboratory of Photovoltaic
Materials of Henan Province, School of Physics, and School of Physics, Henan Normal University, Xinxiang 453007, China
| | - Heng Ma
- Key
Laboratory of Photovoltaic Materials of Henan Province, School
of Material Science and Engineering, Key Laboratory of Photovoltaic
Materials of Henan Province, School of Physics, and School of Physics, Henan Normal University, Xinxiang 453007, China
| | - Jien Yang
- Key
Laboratory of Photovoltaic Materials of Henan Province, School
of Material Science and Engineering, Key Laboratory of Photovoltaic
Materials of Henan Province, School of Physics, and School of Physics, Henan Normal University, Xinxiang 453007, China
| | - Yurong Jiang
- Key
Laboratory of Photovoltaic Materials of Henan Province, School
of Material Science and Engineering, Key Laboratory of Photovoltaic
Materials of Henan Province, School of Physics, and School of Physics, Henan Normal University, Xinxiang 453007, China
| | - Hairui Liu
- Key
Laboratory of Photovoltaic Materials of Henan Province, School
of Material Science and Engineering, Key Laboratory of Photovoltaic
Materials of Henan Province, School of Physics, and School of Physics, Henan Normal University, Xinxiang 453007, China
| | - Zhiyong Liu
- Key
Laboratory of Photovoltaic Materials of Henan Province, School
of Material Science and Engineering, Key Laboratory of Photovoltaic
Materials of Henan Province, School of Physics, and School of Physics, Henan Normal University, Xinxiang 453007, China
| | - Jian Song
- Key
Laboratory of Photovoltaic Materials of Henan Province, School
of Material Science and Engineering, Key Laboratory of Photovoltaic
Materials of Henan Province, School of Physics, and School of Physics, Henan Normal University, Xinxiang 453007, China
| | - ChaoChao Qin
- Key
Laboratory of Photovoltaic Materials of Henan Province, School
of Material Science and Engineering, Key Laboratory of Photovoltaic
Materials of Henan Province, School of Physics, and School of Physics, Henan Normal University, Xinxiang 453007, China
- E-mail: (C.Q.)
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33
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Liu T, Foo Y, Zapien JA, Li M, Tsang SW. A generalized Stark effect electromodulation model for extracting excitonic properties in organic semiconductors. Nat Commun 2019; 10:5089. [PMID: 31704917 PMCID: PMC6841700 DOI: 10.1038/s41467-019-13081-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 10/15/2019] [Indexed: 11/30/2022] Open
Abstract
Electromodulation (EM) spectroscopy, a powerful technique to monitor the changes in polarizability p and dipole moment u of materials upon photo-excitation, can bring direct insight into the excitonic properties of materials. However, extracting Δp and Δu from the electromodulation spectrum relies on fitting with optical absorption of the materials where optical effect in different device geometries might introduce large variation in the extracted values. Here, we demonstrate a systematic electromodulation study with various fitting approaches in both commonly adopted reflection and transmission device architectures. Strikingly, we have found that the previously ascribed continuum state threshold from the deviation between the measured and fitting results is questionable. Such deviation is found to be caused by the overlooked optical interference and electrorefraction effect. A generalized electromodulation model is proposed to incorporate the two effects, and the extracted Δp and Δu have excellent consistency in both reflection and transmission modes in all organic film thicknesses. The development of a generalized electromodulation (EM) spectroscopy model that accurately extracts material parameters for organic electronics remains a challenge. Here, the authors report an EM model that enhances parameter extraction accuracy by accounting for optical interference effects.
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Affiliation(s)
- Taili Liu
- Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Ave, Kowloon Tong, Hong Kong SAR, P. R. China.,Center of Super-Diamond and Advanced Films (COSDAF), City University of Hong Kong, 83 Tat Chee Ave, Kowloon Tong, Hong Kong SAR, P. R. China.,City University of Hong Kong Shenzhen Research Institute, 8 Yuexing No.1 Ave, Nanshan District, Shenzhen, Guangdong, P. R. China
| | - Yishu Foo
- Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Ave, Kowloon Tong, Hong Kong SAR, P. R. China.,Center of Super-Diamond and Advanced Films (COSDAF), City University of Hong Kong, 83 Tat Chee Ave, Kowloon Tong, Hong Kong SAR, P. R. China
| | - Juan Antonio Zapien
- Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Ave, Kowloon Tong, Hong Kong SAR, P. R. China.,Center of Super-Diamond and Advanced Films (COSDAF), City University of Hong Kong, 83 Tat Chee Ave, Kowloon Tong, Hong Kong SAR, P. R. China
| | - Menglin Li
- Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Ave, Kowloon Tong, Hong Kong SAR, P. R. China.,Center of Super-Diamond and Advanced Films (COSDAF), City University of Hong Kong, 83 Tat Chee Ave, Kowloon Tong, Hong Kong SAR, P. R. China.,City University of Hong Kong Shenzhen Research Institute, 8 Yuexing No.1 Ave, Nanshan District, Shenzhen, Guangdong, P. R. China
| | - Sai-Wing Tsang
- Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Ave, Kowloon Tong, Hong Kong SAR, P. R. China. .,Center of Super-Diamond and Advanced Films (COSDAF), City University of Hong Kong, 83 Tat Chee Ave, Kowloon Tong, Hong Kong SAR, P. R. China. .,City University of Hong Kong Shenzhen Research Institute, 8 Yuexing No.1 Ave, Nanshan District, Shenzhen, Guangdong, P. R. China.
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Aoshima K, Nomura M, Saeki A. Regioregularity and Electron Deficiency Control of Unsymmetric Diketopyrrolopyrrole Copolymers for Organic Photovoltaics. ACS OMEGA 2019; 4:15645-15652. [PMID: 31572866 PMCID: PMC6761756 DOI: 10.1021/acsomega.9b02146] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 09/03/2019] [Indexed: 05/31/2023]
Abstract
Manipulating the electron deficiency and controlling the regioregularity of π-conjugated polymers are important for the fine-tuning of their electronic and electrochemical properties to make them suitable for an organic solar cell. Here, we report such a molecular design of unsymmetric diketopyrrolopyrrole (DPP) based copolymers with different aromatic side units of either thiophene (Th), pyridine (Py), or fluorobenzene (FBz). The unsymmetric electron acceptors of Th-DPP-Py and Th-DPP-FBz were polymerized with the electron donor of two-dimensional benzobisthiophene (BDT-Th), affording two regiorandom DPP copolymers. They exhibited contrasting molecular orbital levels and bulk heterojunction morphology in methanofullerene-blended films, leading to power conversion efficiencies of 3.75 and 0.18%, respectively. We further synthesized a regioregular DPP copolymer via sandwiching the centrosymmetric BDT-Th unit by two Th-DPP-Py units in an axisymmetric manner. The extensive characterization through morphology observation, X-ray diffraction, and space-charge-limited current mobilities highlight the case-dependent positive/negative effects of regioregularity and electron deficiency control.
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Affiliation(s)
- Kenta Aoshima
- Department
of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Mayuka Nomura
- Department
of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Akinori Saeki
- Department
of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
- Precursory
Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
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36
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Kim TW, Jun S, Ha Y, Yadav RK, Kumar A, Yoo CY, Oh I, Lim HK, Shin JW, Ryoo R, Kim H, Kim J, Baeg JO, Ihee H. Ultrafast charge transfer coupled with lattice phonons in two-dimensional covalent organic frameworks. Nat Commun 2019; 10:1873. [PMID: 31015440 PMCID: PMC6478948 DOI: 10.1038/s41467-019-09872-w] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 04/04/2019] [Indexed: 11/09/2022] Open
Abstract
Covalent organic frameworks (COFs) have emerged as a promising light-harvesting module for artificial photosynthesis and photovoltaics. For efficient generation of free charge carriers, the donor–acceptor (D-A) conjugation has been adopted for two-dimensional (2D) COFs recently. In the 2D D-A COFs, photoexcitation would generate a polaron pair, which is a precursor to free charge carriers and has lower binding energy than an exciton. Although the character of the primary excitation species is a key factor in determining optoelectronic properties of a material, excited-state dynamics leading to the creation of a polaron pair have not been investigated yet. Here, we investigate the dynamics of photogenerated charge carriers in 2D D-A COFs by combining femtosecond optical spectroscopy and non-adiabatic molecular dynamics simulation. From this investigation, we elucidate that the polaron pair is formed through ultrafast intra-layer hole transfer coupled with coherent vibrations of the 2D lattice, suggesting a mechanism of phonon-assisted charge transfer. The donor–acceptor (D-A) conjugation has been adopted for two-dimensional (2D) covalent organic frameworks (COFs) for efficient generation of free charge carriers. Here, the authors investigate the dynamics of photogenerated charge carriers in 2D D-A COFs by combining femtosecond optical spectroscopy and non-adiabatic molecular dynamics simulation.
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Affiliation(s)
- Tae Wu Kim
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.,KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.,Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon, 34141, Republic of Korea.,Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois, 60439, USA
| | - Sunhong Jun
- Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon, 34141, Republic of Korea.,Memory Business, Samsung Electronics, Gyeonggi-do, 18448, Republic of Korea
| | - Yoonhoo Ha
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Rajesh K Yadav
- Artificial Photosynthesis Research Group, Korea Research Institute of Chemical Technology (KRICT), Daejeon, 34114, Republic of Korea
| | - Abhishek Kumar
- Artificial Photosynthesis Research Group, Korea Research Institute of Chemical Technology (KRICT), Daejeon, 34114, Republic of Korea
| | - Chung-Yul Yoo
- Korea Institute of Energy Research (KIER), Daejeon, 34129, Republic of Korea
| | - Inhwan Oh
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.,KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.,Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon, 34141, Republic of Korea
| | - Hyung-Kyu Lim
- Department of Chemical Engineering, Kangwon National University, Gangwon-do, 24341, Republic of Korea
| | - Jae Won Shin
- Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon, 34141, Republic of Korea
| | - Ryong Ryoo
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.,Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon, 34141, Republic of Korea
| | - Hyungjun Kim
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.
| | - Jeongho Kim
- Department of Chemistry, Inha University, Incheon, 22212, Republic of Korea.
| | - Jin-Ook Baeg
- Artificial Photosynthesis Research Group, Korea Research Institute of Chemical Technology (KRICT), Daejeon, 34114, Republic of Korea.
| | - Hyotcherl Ihee
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea. .,KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea. .,Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon, 34141, Republic of Korea.
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37
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Patel J, Sharma A, Chauhan M, Aatif M, Vashistha N, Kumar M, Tripathi B, Chand S, Tiwari JP, Pandey MK. Understanding charge carrier dynamics in a P3HT:FLR blend. Phys Chem Chem Phys 2019; 21:2771-2782. [PMID: 30667010 DOI: 10.1039/c8cp05518a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In organic semiconductors, optical absorption is pivotal for the performance of optoelectronic devices. The absorption by the semiconductors generates excitons which dissociate into free charge carriers, resulting in energy conversion. Although high performance has been achieved in non-fullerene organic solar cells, their charge generation behavior is far from being well understood. Keeping this in view, we have employed optical spectroscopic tools to study the charge generation mechanism in FLR (1,6,7,10-tetramethylfluoranthene) as a non-fullerene electron acceptor blended with P3HT (poly(3-hexylthiophene)) as an electron donor in five different solvents. Through steady state UV-visible and photoluminescence spectroscopy, we provide a basic understanding of charge transport by enlightening the influence of solvents on the aggregation behavior and exciton bandwidth. Furthermore, for the first time, by employing ultrafast vis-NIR transient absorption spectroscopy, we address the ultrafast charge generation and charge separation mechanism with systematic variation in solvent polarity by incorporating the time evolution of the transient species under various pump-probe wavelengths in the range of 450 nm to 1600 nm. For the different excitation wavelengths, the lifetime kinetics have been depicted by their multiexponential fits. The results show a fast decay term at a lifetime of a few picoseconds (ps) (∼1 to 5 ps) and a slow decay term at a lifetime of ∼500 ps. The charge generation in the P3HT:FLR blend proceeds on a ps time scale, which implies good intermixing of the components. It is clearly established that the non-halogenated solvents influence this aggregation behavior and higher conjugation lengths with higher photoluminescence quenching contribute to the higher charge generation. The enhanced polaron population in P3HT with the addition of FLR illustrates the importance of this acceptor material in the blend because a good solvent-material combination is essential to enhance the charge generation. As such, this comprehensive study explicitly shows the role of FLR as an emerging efficient non-fullerene acceptor for further improving the performance of devices.
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Affiliation(s)
- Jessica Patel
- Department of Science, School of Technology, Pandit Deendayal Petroleum University, Gandhinagar 382007, India.
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38
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Ultrafast hole transfer mediated by polaron pairs in all-polymer photovoltaic blends. Nat Commun 2019; 10:398. [PMID: 30674887 PMCID: PMC6344565 DOI: 10.1038/s41467-019-08361-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Accepted: 01/08/2019] [Indexed: 11/24/2022] Open
Abstract
The charge separation yield at a bulk heterojunction sets the upper efficiency limit of an organic solar cell. Ultrafast charge transfer processes in polymer/fullerene blends have been intensively studied but much less is known about these processes in all-polymer systems. Here, we show that interfacial charge separation can occur through a polaron pair-derived hole transfer process in all-polymer photovoltaic blends, which is a fundamentally different mechanism compared to the exciton-dominated pathway in the polymer/fullerene blends. By utilizing ultrafast optical measurements, we have clearly identified an ultrafast hole transfer process with a lifetime of about 3 ps mediated by photo-excited polaron pairs which has a markedly high quantum efficiency of about 97%. Spectroscopic data show that excitons act as spectators during the efficient hole transfer process. Our findings suggest an alternative route to improve the efficiency of all-polymer solar devices by manipulating polaron pairs. All-polymer solar cells have shown high efficiencies but the ultrafast charge transfer processes are less known. Here Wang et al. show that polaron pairs play vital role facilitating the hole transfer, which is quite different from the exciton dominated pathway in polymer-fullerene blends.
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39
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Tegegne NA, Abdissa Z, Mammo W, Andersson MR, Schlettwein D, Schwoerer H. Ultrafast excited state dynamics of a bithiophene-isoindigo copolymer obtained by direct arylation polycondensation and its application in indium tin oxide-free solar cells. ACTA ACUST UNITED AC 2018. [DOI: 10.1002/polb.24743] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Newayemedhin A. Tegegne
- Physics Department, Laser Research Institute; Stellenbosch University; Stellenbosch South Africa
| | - Zelalem Abdissa
- Science Faculty, Department of Chemistry; Addis Ababa University; P.O. Box 33658, Addis Ababa Ethiopia
| | - Wendimagegn Mammo
- Science Faculty, Department of Chemistry; Addis Ababa University; P.O. Box 33658, Addis Ababa Ethiopia
| | - Mats R. Andersson
- Future Industries Institute, University of South Australia; Mawson Lakes Boulevard, Mawson Lakes South Australia 5095 Australia
| | - Derck Schlettwein
- Institute of Applied Physics, Justus-Liebig-University; Heinrich Buff Ring 16, 35392 Giessen Germany
| | - Heinrich Schwoerer
- Physics Department, Laser Research Institute; Stellenbosch University; Stellenbosch South Africa
- Max Planck Institute for the Structure and Dynamics of Matter; Luruper Chaussee 149, 22761 Hamburg Germany
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40
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Korovina NV, Joy J, Feng X, Feltenberger C, Krylov AI, Bradforth SE, Thompson ME. Linker-Dependent Singlet Fission in Tetracene Dimers. J Am Chem Soc 2018; 140:10179-10190. [PMID: 30016102 DOI: 10.1021/jacs.8b04401] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Separation of triplet excitons produced by singlet fission is crucial for efficient application of singlet fission materials. While earlier works explored the first step of singlet fission, the formation of the correlated triplet pair state, the focus of recent studies has been on understanding the second step of singlet fission, the formation of independent triplets from the correlated pair state. We present the synthesis and excited-state dynamics of meta- and para-bis(ethynyltetracenyl)benzene dimers that are analogues to the ortho-bis(ethynyltetracenyl)benzene dimer reported by our groups previously. A comparison of the excited-state properties of these dimers allows us to investigate the effects of electronic conjugation and coupling on singlet fission between the ethynyltetracene units within a dimer. In the para isomer, in which the two chromophores are conjugated, the singlet exciton yields the correlated triplet pair state, from which the triplet excitons can decouple via molecular rotations. In contrast, the meta isomer in which the two chromophores are cross-coupled predominantly relaxes via radiative decay. We also report the synthesis and excited-state dynamics of two para dimers with different bridging units joining the ethynyltetracenes. The rate of singlet fission is found to be faster in the dimer with the bridging unit that has orbitals closer in energy to that of the ethynyltetracene chromophores.
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Affiliation(s)
- Nadezhda V Korovina
- Department of Chemistry , University of Southern California , Los Angeles , California 90089 , United States
| | - Jimmy Joy
- Department of Chemistry , University of Southern California , Los Angeles , California 90089 , United States
| | - Xintian Feng
- Department of Chemistry , University of Southern California , Los Angeles , California 90089 , United States
| | - Cassidy Feltenberger
- Department of Chemistry , University of Southern California , Los Angeles , California 90089 , United States
| | - Anna I Krylov
- Department of Chemistry , University of Southern California , Los Angeles , California 90089 , United States
| | - Stephen E Bradforth
- Department of Chemistry , University of Southern California , Los Angeles , California 90089 , United States
| | - Mark E Thompson
- Department of Chemistry , University of Southern California , Los Angeles , California 90089 , United States
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41
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Gautam B, Klump E, Yi X, Constantinou I, Shewmon N, Salehi A, Lo CK, Zheng Z, Brédas JL, Gundogdu K, Reynolds JR, So F. Increased Exciton Delocalization of Polymer upon Blending with Fullerene. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1801392. [PMID: 29893011 DOI: 10.1002/adma.201801392] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 05/02/2018] [Indexed: 06/08/2023]
Abstract
Interfaces between donor and acceptor in a polymer solar cell play a crucial role in exciton dissociation and charge photogeneration. While the importance of charge transfer (CT) excitons for free carrier generation is intensively studied, the effect of blending on the nature of the polymer excitons in relation to the blend nanomorphology remains largely unexplored. In this work, electroabsorption (EA) spectroscopy is used to study the excited-state polarizability of polymer excitons in several polymer:fullerene blend systems, and it is found that excited-state polarizability of polymer excitons in the blends is a strong function of blend nanomorphology. The increase in excited-state polarizability with decreased domain size indicates that intermixing of states at the interface between the donor polymers and fullerene increases the exciton delocalization, resulting in an increase in exciton dissociation efficiency. This conclusion is further supported by transient absorption spectroscopy and time-resolved photoluminescence measurements, along with the results from time-dependent density functional theory calculations. These findings indicate that polymer excited-state polarizability is a key parameter for efficient free carrier generation and should be considered in the design and development of high-performance polymer solar cells.
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Affiliation(s)
- Bhoj Gautam
- Department of Physics, North Carolina State University, Raleigh, NC, 27695, USA
| | - Erik Klump
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC, 27695, USA
| | - Xueping Yi
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC, 27695, USA
| | - Iordania Constantinou
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC, 27695, USA
| | - Nathan Shewmon
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC, 27695, USA
| | - Amin Salehi
- Department of Physics, North Carolina State University, Raleigh, NC, 27695, USA
| | - Chi Kin Lo
- School of Chemistry and Biochemistry, Center for Organic Photonics and Electronics, Georgia Tech Polymer Network, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Zilong Zheng
- School of Chemistry and Biochemistry, Center for Organic Photonics and Electronics, Georgia Tech Polymer Network, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Jean-Luc Brédas
- School of Chemistry and Biochemistry, Center for Organic Photonics and Electronics, Georgia Tech Polymer Network, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Kenan Gundogdu
- Department of Physics, North Carolina State University, Raleigh, NC, 27695, USA
| | - John R Reynolds
- School of Chemistry and Biochemistry, Center for Organic Photonics and Electronics, Georgia Tech Polymer Network, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Franky So
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC, 27695, USA
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42
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Benatto L, Marchiori CFN, da Luz MGE, Koehler M. Electronic and structural properties of fluorene–thiophene copolymers as function of the composition ratio between the moieties: a theoretical study. Phys Chem Chem Phys 2018; 20:20447-20458. [DOI: 10.1039/c8cp02622j] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Through theoretical analysis, we study relevant properties of some molecular structures formed by oligothiophenes (T) and dioctylfluorenes (F) units, like the exciton binding energy (Eb) and dipole moment, important for the efficiency of different kinds of optical and electronic devices.
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Affiliation(s)
- L. Benatto
- Departamento de Física
- Universidade Federal do Paraná
- Curitiba
- Brazil
| | - C. F. N. Marchiori
- Departamento de Física
- Universidade Federal do Paraná
- Curitiba
- Brazil
- Department of Physics and Astronomy
| | - M. G. E. da Luz
- Departamento de Física
- Universidade Federal do Paraná
- Curitiba
- Brazil
| | - M. Koehler
- Departamento de Física
- Universidade Federal do Paraná
- Curitiba
- Brazil
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43
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Roy P, Jha A, Yasarapudi VB, Ram T, Puttaraju B, Patil S, Dasgupta J. Ultrafast bridge planarization in donor-π-acceptor copolymers drives intramolecular charge transfer. Nat Commun 2017; 8:1716. [PMID: 29170455 PMCID: PMC5700982 DOI: 10.1038/s41467-017-01928-z] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2017] [Accepted: 10/24/2017] [Indexed: 11/09/2022] Open
Abstract
Donor-π-acceptor conjugated polymers form the material basis for high power conversion efficiencies in organic solar cells. Large dipole moment change upon photoexcitation via intramolecular charge transfer in donor-π-acceptor backbone is conjectured to facilitate efficient charge-carrier generation. However, the primary structural changes that drive ultrafast charge transfer step have remained elusive thereby limiting a rational structure-function correlation for such copolymers. Here we use structure-sensitive femtosecond stimulated Raman spectroscopy to demonstrate that π-bridge torsion forms the primary reaction coordinate for intramolecular charge transfer in donor-π-acceptor copolymers. Resonance-selective Raman snapshots of exciton relaxation reveal rich vibrational dynamics of the bridge modes associated with backbone planarization within 400 fs, leading to hot intramolecular charge transfer state formation while subsequent cooling dynamics of backbone-centric modes probe the charge transfer relaxation. Our work establishes a phenomenological gating role of bridge torsions in determining the fundamental timescale and energy of photogenerated carriers, and therefore opens up dynamics-based guidelines for fabricating energy-efficient organic photovoltaics.
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Affiliation(s)
- Palas Roy
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai, 400005, India
| | - Ajay Jha
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai, 400005, India
| | - Vineeth B Yasarapudi
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai, 400005, India
| | - Thulasi Ram
- Department of Nuclear and Atomic Physics, Tata Institute of Fundamental Research, Mumbai, 400005, India
| | - Boregowda Puttaraju
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, 560012, India
| | - Satish Patil
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, 560012, India
| | - Jyotishman Dasgupta
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai, 400005, India.
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44
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Penwell SB, Ginsberg LDS, Noriega R, Ginsberg NS. Resolving ultrafast exciton migration in organic solids at the nanoscale. NATURE MATERIALS 2017; 16:1136-1141. [PMID: 28920937 DOI: 10.1038/nmat4975] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2016] [Accepted: 07/25/2017] [Indexed: 05/16/2023]
Abstract
Effectiveness of molecular-based light harvesting relies on transport of excitons to charge-transfer sites. Measuring exciton migration, however, has been challenging because of the mismatch between nanoscale migration lengths and the diffraction limit. Instead of using bulk substrate quenching methods, here we define quenching boundaries all-optically with sub-diffraction resolution, thus characterizing spatiotemporal exciton migration on its native nanometre and picosecond scales. By transforming stimulated emission depletion microscopy into a time-resolved ultrafast approach, we measure a 16-nm migration length in poly(2,5-di(hexyloxy)cyanoterephthalylidene) conjugated polymer films. Combined with Monte Carlo exciton hopping simulations, we show that migration in these films is essentially diffusive because intrinsic chromophore energetic disorder is comparable to chromophore inhomogeneous broadening. Our approach will enable previously unattainable correlation of local material structure to exciton migration character, applicable not only to photovoltaic or display-destined organic semiconductors but also to explaining the quintessential exciton migration exhibited in photosynthesis.
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Affiliation(s)
- Samuel B Penwell
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Lucas D S Ginsberg
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Rodrigo Noriega
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Naomi S Ginsberg
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Kavli Energy NanoScience Institute, Berkeley, California 94720, USA
- Department of Physics, University of California, Berkeley, California 94720, USA
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45
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Busireddy MR, Chereddy NR, Shanigaram B, Kotamarthi B, Biswas S, Sharma GD, Vaidya JR. Dithieno[3,2-b:2',3'-d]pyrrole-benzo[c][1,2,5]thiadiazole conjugate small molecule donors: effect of fluorine content on their photovoltaic properties. Phys Chem Chem Phys 2017; 19:20513-20522. [PMID: 28730205 DOI: 10.1039/c7cp02729j] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two new small molecule donors, namely ICT4 and ICT6 with D1-A-D2-A-D1 architecture having 2,4-bis(2-ethylhexyl)-4H-dithieno[3,2-b:2',3'-d]pyrrole (EHDTP, D1) and 4,8-bis((2-ethylhexyl)oxy)benzo[1,2-b:4,5-b']dithiophene (OBDT, D2) as the terminal and central donor, and benzo[c][1,2,5]thiadiazole (BT for ICT4) and 5,6-difluorobenzo[c][1,2,5]thiadiazole (F2BT for ICT6) as the acceptor (A) moieties, are synthesized and their optical, electronic and photovoltaic properties are investigated. Both ICT4 and ICT6 have considerable solubility in various solvents and possess efficient light absorption ability [ε (×105 mol-1 cm-1) is 0.99 and 1.06, respectively for ICT4 and ICT6] and appropriate frontier molecular orbital energy offsets with [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM). Bulk heterojunction solar cells (BHJSCs) are fabricated using ICT4/ICT6 and PC71BM as donors and acceptors, respectively and BHJSCs with two-step annealed (thermal followed by solvent vapor annealing) active layers of ICT4 and ICT6 show overall power conversion efficiencies (PCEs) of 5.46% and 7.91%, respectively. The superior photovoltaic performance of the ICT6 based BHJSCs is due to the favourable morphology with a nanoscale interpenetrating network in the ICT6:PC71BM active layer induced by the fluorine atoms on the BT acceptor, which significantly enhances the dissociation of excitons, charge transport and the charge collection efficiency, and suppresses bimolecular recombination in the BHJ. The observed higher PCE of 7.91% indicates that ICT6 is one of the best BT based donor material for small molecular BHJSCs.
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Affiliation(s)
- Manohar Reddy Busireddy
- Crop Protection Chemicals Division, CSIR-Indian Institute of Chemical Technology, Hyderabad-500007, India.
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46
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Ide M, Saeki A. Fluorinated Benzothienoisoindigo Copolymers for Organic Solar Cells: A Comparative Study on Polymer Orientation and Device Performance. CHEM LETT 2017. [DOI: 10.1246/cl.170307] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Marina Ide
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871
| | - Akinori Saeki
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871
- PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012
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Wang T, Weerasinghe KC, Sun H, Li P, Liu D, Li W, Hu W, Zhou X, Wang L. Characterization of photo-induced electron and hole transfer in a porphyrin based ambipolar organic molecule with cascade energy levels. J Mol Struct 2017. [DOI: 10.1016/j.molstruc.2017.04.079] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Mosquera MA, Jackson NE, Fauvell TJ, Kelley MS, Chen LX, Schatz GC, Ratner MA. Exciton Absorption Spectra by Linear Response Methods: Application to Conjugated Polymers. J Am Chem Soc 2017; 139:3728-3735. [DOI: 10.1021/jacs.6b12405] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Martín A. Mosquera
- Department
of Chemistry and the Materials Research Center, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Nicholas E. Jackson
- Department
of Chemistry and the Materials Research Center, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
- Chemical
Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439, United States
| | - Thomas J. Fauvell
- Department
of Chemistry and the Materials Research Center, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Matthew S. Kelley
- Department
of Chemistry and the Materials Research Center, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Lin X. Chen
- Department
of Chemistry and the Materials Research Center, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
- Chemical
Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439, United States
| | - George C. Schatz
- Department
of Chemistry and the Materials Research Center, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Mark A. Ratner
- Department
of Chemistry and the Materials Research Center, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
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An investigation of the role the donor moiety plays in modulating the efficiency of ‘donor-π-acceptor-π-acceptor’ organic DSSCs. Tetrahedron 2017. [DOI: 10.1016/j.tet.2016.12.061] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Yang J, Zhang Z, Qin Y. A Molecular Tetrapod for Organic Photovoltaics. ACS APPLIED MATERIALS & INTERFACES 2016; 8:22392-22401. [PMID: 27514435 DOI: 10.1021/acsami.6b06365] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The synthesis and characterization of a molecular tetrapod, SFBTD, featuring a tetraphenylsilane center and four identical conjugated arms, which structurally resembles breakwaters in common wave-reducing shore constructions, are reported. Cyclic voltammetry reveals that SFBTD has a medium band gap of ca. 2.0 eV and a low-lying HOMO energy level at ca. -5.2 eV. Absorption spectroscopy, X-ray diffraction, and differential scanning calorimetry experiments reveal a low degree of crystallinity in this compound and slow crystallization kinetics. Bulk heterojunction organic photovoltaics (OPVs) employing SFBTD and fullerene derivatives exhibit power conversion efficiencies (PCEs) up to 1.05% and open-circuit voltage (VOC) values as high as 1.02 V. To the best of our knowledge, this is the highest PCE obtained for OPVs employing molecular tetrapods as donor materials. These devices are relatively thermally stable due to the known ability of breakwater tetrapods to interlock, preventing dislodging and sliding. The lack of favorable phase separations and low hole mobilities of the blend films are the major factors limiting the device performance. Ternary blend devices by the addition of three low band gap poly(thienylene vinylene) (PTV) derivatives were fabricated and tested. We found that the added PTVs acted to be either the major hole conductor or a competing hole conduction channel depending on the HOMO level positions relative to that of SFBTD. Some of the ternary OPV devices out-performed the corresponding binary counterparts employing SFBTD or PTVs alone, suggesting cooperative effects in the ternary systems.
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Affiliation(s)
- Jianzhong Yang
- Department of Chemistry & Chemical Biology, University of New Mexico , MSC03 2060, 1 UNM, Albuquerque, New Mexico 87131, United States
| | - Zhen Zhang
- Department of Chemistry & Chemical Biology, University of New Mexico , MSC03 2060, 1 UNM, Albuquerque, New Mexico 87131, United States
| | - Yang Qin
- Department of Chemistry & Chemical Biology, University of New Mexico , MSC03 2060, 1 UNM, Albuquerque, New Mexico 87131, United States
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