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Li J, Ji Q, Wang R, Zhang ZG, Wang X, Xiao M, Lu YQ, Zhang C. Charge Generation Dynamics in Organic Photovoltaic Blends under One-Sun-Equivalent Illumination Detected by Highly Sensitive Terahertz Spectroscopy. J Am Chem Soc 2024. [PMID: 38980945 DOI: 10.1021/jacs.4c05786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/11/2024]
Abstract
Organic photovoltaic (OPV) devices attain high performance with nonfullerene acceptors by utilizing the synergistic dual channels of charge generation that originate from excitations in both the donor and acceptor materials. However, the specific intermediate states that facilitate both channels are subject to debate. To address this issue, we employ time-resolved terahertz spectroscopy with improved sensitivity (ΔE/E < 10-6), enabling direct probing of charge generation dynamics in a prototypical PM6:Y6 bulk heterojunction system under one-sun-equivalent excitation density. Charge generation arising from donor excitations is characterized with a rise time of ∼9 ps, while that from acceptor excitations shows a rise time of ∼18 ps. Temperature-dependent measurements further reveal notably distinct activation energies for these two charge generation pathways. Additionally, the two channels of charge generation can be substantially manipulated by altering the ratio of bulk to interfaces. These findings strongly suggest the presence of two distinct intermediate states: interfacial and intramoiety excitations. These states are crucial in mediating the transfer of electrons and holes, driving charge generation within OPV devices.
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Affiliation(s)
- Jiacong Li
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Qing Ji
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Rui Wang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing 210093, China
- College of Physics, Nanjing University of Aeronautics and Astronautics, and Key Laboratory of Aerospace Information Materials and Physics (NUAA), MIIT, Nanjing 211106, China
- Institute of Materials Engineering, Nanjing University, Nantong, Jiangsu 226019, China
| | - Zhi-Guo Zhang
- State Key Laboratory of Organic/Inorganic Composites, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Xiaoyong Wang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Min Xiao
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing 210093, China
- Department of Physics, University of Arkansas, Fayetteville, Arkansas 72701, United States
| | - Yan-Qing Lu
- National Laboratory of Solid State Microstructures, Key Laboratory of Intelligent Optical Sensing and Manipulation, College of Engineering and Applied Sciences, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210023, China
| | - Chunfeng Zhang
- National Laboratory of Solid State Microstructures, School of Physics, and Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing 210093, China
- Institute of Materials Engineering, Nanjing University, Nantong, Jiangsu 226019, China
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2
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Banappanavar G, Saxena R, Bässler H, Köhler A, Kabra D. Impact of Photoluminescence Imaging Methodology on Transport Parameters in Semiconductors. J Phys Chem Lett 2024; 15:3109-3117. [PMID: 38470078 DOI: 10.1021/acs.jpclett.4c00169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
Triplet-triplet annihilation-induced delayed emission provides a pathway for investigating triplets via emission spectroscopy. This bimolecular annihilation depends directly on the transport properties of triplet excitons in disordered organic semiconductors. Photoluminescence (PL) imaging is a direct method for studying exciton and charge-carrier diffusivity. However, most of these studies neglect dispersive transport. Early time scale measurements using this technique can lead to an overestimation of the diffusion coefficient (DT) or diffusion length (Ld). In this study, we investigated the time-dependent triplet DT using PL imaging. We observed an overestimation of Ld in classical delayed PL imaging, often 1 order of magnitude higher than the actual Ld value. We compared various thicknesses of polymeric thin films to study the dispersive nature of triplet excitons. Transient analysis of delayed PL imaging and steady state imaging reveals the importance of considering the time-dependent nature of DT for the triplet excitons in disordered electronic materials.
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Affiliation(s)
- Gangadhar Banappanavar
- Department of Physics, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Rishabh Saxena
- Soft Matter Optoelectronics and Bavarian Polymer Institute (BPS), University of Bayreuth, Universitätsstrasse 30, 95440 Bayreuth, Germany
| | - Heinz Bässler
- Bayreuth Institute of Macromolecular Research (BIMF), University of Bayreuth, Universitätsstrasse 30, 95440 Bayreuth, Germany
| | - Anna Köhler
- Soft Matter Optoelectronics and Bavarian Polymer Institute (BPS), University of Bayreuth, Universitätsstrasse 30, 95440 Bayreuth, Germany
- Bayreuth Institute of Macromolecular Research (BIMF), University of Bayreuth, Universitätsstrasse 30, 95440 Bayreuth, Germany
| | - Dinesh Kabra
- Department of Physics, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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3
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Chen J, Lou YH, Wang ZK. Characterizing Spatial and Energetic Distributions of Trap States Toward Highly Efficient Perovskite Photovoltaics. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2305064. [PMID: 37635401 DOI: 10.1002/smll.202305064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/15/2023] [Indexed: 08/29/2023]
Abstract
Due to their greater opt electric performance, perovskite photovoltaics (PVs) present huge potential to be commercialized. Perovskite PV's high theoretical efficiency expands the available development area. The passivation of defects in perovskite films is crucial for approaching the theoretical limit. In addition to creating efficient passivation techniques, it is essential to direct the passivation approach by getting precise and real-time information on the trap states through measurements. Therefore, it is necessary to establish quantitative characterization methods for the trap states in energy and 3D spaces. The authors cover the characterization of the spatial and energy distributions of trap states in this article with an eye toward high-efficiency perovskite photovoltaics. After going over the strategies that have been created for characterizing and evaluating trap states, the authors will concentrate on how to direct the creative development of characterization techniques for trap states assessment and highlight the opportunities and challenges of future development. The 3D space and energy distribution mappings of trap states are anticipated to be realized. The review will give key guiding importance for further approaching the theoretical efficiency of perovskite photovoltaics, offering some future research direction and technological assistance for the development of appropriate targeted passivation technologies.
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Affiliation(s)
- Jing Chen
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, 215123, China
| | - Yan-Hui Lou
- College of Energy, Soochow Institute for Energy and Materials Innovations, Soochow University, Suzhou, 215006, China
| | - Zhao-Kui Wang
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, 215123, China
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4
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Lukin L. Efficiency of exciton dissociation at the interface between a conjugated polymer and an electron acceptor with consideration for a two-dimensional arrangement of interfacial dipoles. Chem Phys 2021. [DOI: 10.1016/j.chemphys.2021.111327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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5
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Dynamic behavior of photogenerated charge carriers in diketopyrrolopyrrole-linked tetrabenzoporphyrin-based bulk heterojunction thin films probed with time-resolved terahertz spectroscopy. J Photochem Photobiol A Chem 2020. [DOI: 10.1016/j.jphotochem.2020.112693] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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6
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Vibronic coherence contributes to photocurrent generation in organic semiconductor heterojunction diodes. Nat Commun 2020; 11:617. [PMID: 32001688 PMCID: PMC6992633 DOI: 10.1038/s41467-020-14476-w] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 01/09/2020] [Indexed: 11/24/2022] Open
Abstract
Charge separation dynamics after the absorption of a photon is a fundamental process relevant both for photosynthetic reaction centers and artificial solar conversion devices. It has been proposed that quantum coherence plays a role in the formation of charge carriers in organic photovoltaics, but experimental proofs have been lacking. Here we report experimental evidence of coherence in the charge separation process in organic donor/acceptor heterojunctions, in the form of low frequency oscillatory signature in the kinetics of the transient absorption and nonlinear two-dimensional photocurrent spectroscopy. The coherence plays a decisive role in the initial ~200 femtoseconds as we observe distinct experimental signatures of coherent photocurrent generation. This coherent process breaks the energy barrier limitation for charge formation, thus competing with excitation energy transfer. The physics may inspire the design of new photovoltaic materials with high device performance, which explore the quantum effects in the next-generation optoelectronic applications. Although coherent vibrational motion in donor-acceptor blends may contribute to photogeneration generation in organic solar cells (OSCs), proof of a direct correlation is still lacking. Here, the authors report the role of vibrational coherence on photocurrent generation in ternary OSC blends.
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7
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Melianas A, Kemerink M. Photogenerated Charge Transport in Organic Electronic Materials: Experiments Confirmed by Simulations. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1806004. [PMID: 30719756 DOI: 10.1002/adma.201806004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Revised: 10/29/2018] [Indexed: 06/09/2023]
Abstract
The performance of organic optoelectronic devices, such as organic photovoltaic (OPV) cells, is to a large extent dictated by their ability to transport the photogenerated charge, with relevant processes spanning a wide temporal (fs-µs) and spatial (1-100 nm) range. However, time-resolved techniques can access only a limited temporal window, and often contradict steady-state measurements. Here, commonly employed steady-state and time-resolved techniques are unified over an exceptionally wide temporal range (fs-µs) in a consistent physical picture. Experimental evidence confirmed by numerical simulations shows that, although various techniques probe different time scales, they are mutually consistent as they probe the same physical mechanisms governing charge motion in disordered media-carrier hopping and thermalization in a disorder-broadened density of states (DOS). The generality of this framework is highlighted by time-resolved experimental data obtained on polymer:fullerene, polymer:polymer, and small-molecule blends with varying morphology, including recent experiments revealing that low donor content OPV devices operate by long-range hole tunneling between non-nearest-neighbor molecules. The importance of nonequilibrium processes in organic electronic materials is reviewed, with a particular focus on experimental data and understanding charge transport physics in terms of material DOS.
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Affiliation(s)
- Armantas Melianas
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Martijn Kemerink
- Complex Materials and Devices, Department of Physics, Chemistry and Biology, Linköping University, 58183, Linköping, Sweden
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8
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Inganäs O. Organic Photovoltaics over Three Decades. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1800388. [PMID: 29938847 DOI: 10.1002/adma.201800388] [Citation(s) in RCA: 235] [Impact Index Per Article: 39.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 03/20/2018] [Indexed: 05/20/2023]
Abstract
The development of organic semiconductors for photovoltaic devices, over the last three decades, has led to unexpected performance for an alternative choice of materials to convert sunlight to electricity. New materials and developed concepts have improved the photovoltage in organic photovoltaic devices, where records are now found above 13% power conversion efficiency in sunlight. The author has stayed with the topic of organic materials for energy conversion and energy storage during these three decades, and makes use of the Hall of Fame now built by Advanced Materials, to present his view of the path travelled over this time, including motivations, personalities, and ambitions.
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Affiliation(s)
- Olle Inganäs
- Biomolecular and Organic Electronics, Department of Physics, Chemistry and Biology (IFM), Linköping University, S-581 83, Linköping, Sweden
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9
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Ohta K, Tokonami S, Takahashi K, Tamura Y, Yamada H, Tominaga K. Probing Charge Carrier Dynamics in Porphyrin-Based Organic Semiconductor Thin Films by Time-Resolved THz Spectroscopy. J Phys Chem B 2017; 121:10157-10165. [DOI: 10.1021/acs.jpcb.7b07025] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kaoru Ohta
- Molecular
Photoscience Research Center, Kobe University, 1-1 Rokkodai-cho, Nada, Kobe 657-8501, Japan
- Graduate
School of Science, Kobe University, 1-1 Rokkodai-cho, Nada, Kobe 657-8501, Japan
| | - Shunrou Tokonami
- Graduate
School of Science, Kobe University, 1-1 Rokkodai-cho, Nada, Kobe 657-8501, Japan
| | - Kotaro Takahashi
- Graduate
School of Materials Science, Nara Institute of Science and Technology, 8916-5, Takayama-cho, Ikoma, Nara 630-0192, Japan
| | - Yuto Tamura
- Graduate
School of Materials Science, Nara Institute of Science and Technology, 8916-5, Takayama-cho, Ikoma, Nara 630-0192, Japan
| | - Hiroko Yamada
- Graduate
School of Materials Science, Nara Institute of Science and Technology, 8916-5, Takayama-cho, Ikoma, Nara 630-0192, Japan
| | - Keisuke Tominaga
- Molecular
Photoscience Research Center, Kobe University, 1-1 Rokkodai-cho, Nada, Kobe 657-8501, Japan
- Graduate
School of Science, Kobe University, 1-1 Rokkodai-cho, Nada, Kobe 657-8501, Japan
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10
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Ponseca CS, Chábera P, Uhlig J, Persson P, Sundström V. Ultrafast Electron Dynamics in Solar Energy Conversion. Chem Rev 2017; 117:10940-11024. [DOI: 10.1021/acs.chemrev.6b00807] [Citation(s) in RCA: 211] [Impact Index Per Article: 30.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Carlito S. Ponseca
- Division
of Chemical Physics, Chemical Center, and ‡Theoretical Chemistry Division,
Chemical Center, Lund University, Box 124, Lund SE-221 00, Sweden
| | - Pavel Chábera
- Division
of Chemical Physics, Chemical Center, and ‡Theoretical Chemistry Division,
Chemical Center, Lund University, Box 124, Lund SE-221 00, Sweden
| | - Jens Uhlig
- Division
of Chemical Physics, Chemical Center, and ‡Theoretical Chemistry Division,
Chemical Center, Lund University, Box 124, Lund SE-221 00, Sweden
| | - Petter Persson
- Division
of Chemical Physics, Chemical Center, and ‡Theoretical Chemistry Division,
Chemical Center, Lund University, Box 124, Lund SE-221 00, Sweden
| | - Villy Sundström
- Division
of Chemical Physics, Chemical Center, and ‡Theoretical Chemistry Division,
Chemical Center, Lund University, Box 124, Lund SE-221 00, Sweden
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11
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Kulshreshtha C, Son J, Pascher T, Kim JH, Joo T, Lee J, Jeong MS, Cho K. Excitation Intensity Dependent Carrier Dynamics of Chalcogen Heteroatoms in Medium-Bandgap Polymer Solar Cells. Sci Rep 2017; 7:836. [PMID: 28400589 PMCID: PMC5429773 DOI: 10.1038/s41598-017-00834-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 03/09/2017] [Indexed: 11/09/2022] Open
Abstract
The excitation intensity dependent carrier dynamics of blends with PC[70]BM of three new medium-band gap conjugated polymers with central chalcogen heteroatoms, PBDTfDTBX (X = O, T(Sulphur), Se) were studied. The PBDTfDTBX polymers (Poly[4,8-bis(5-(2-butyloctyl)thiophene-2-yl)benzo[1,2-b;4,5-b′]dithiophene-alt-4,7-bis(4-(2-ethylhexyl)-2-thienyl)-dithieno[3′,2′:3,4;2″,3″:5,6]benzo[1,2-c][1,2,5] furazan or thiadiazole or selenadiazole]) have symmetrical structures but exhibit different solar cell performances. In this study, we determined how the photogenerated charge carrrier dynamics of the PBDTfDTBX:PC[70]BM blends varies with the heteroatom by performing transient absorption measurements at various excitation intensities. It was found that the charge carrier dynamics of the PBDTfDTBX blends with X = T or Se heteroatoms are dependent on the excitation intensity whereas that of the PBDTfDTBO blend is independent of the intensity. The photogenerated charge carrier dynamics of the PBDTfDTBO:PCBM, PBDTfDTBT:PCBM, and PBDTfDTBSe:PCBM blends were all modeled globally and rates were estimated for different photophysical processes occurring on different time scales.
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Affiliation(s)
- Chandramouli Kulshreshtha
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - Jiwon Son
- Department of Chemistry, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - Torbjörn Pascher
- Chemical Physics, Kemicentrum, Lund University, SE-22100, Lund, Sweden
| | - Ji-Hee Kim
- Department of Energy Science, Sungkyunkwan University, Suwon, Korea
| | - Taiha Joo
- Department of Chemistry, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - Jaewon Lee
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - Mun Seok Jeong
- Department of Energy Science, Sungkyunkwan University, Suwon, Korea
| | - Kilwon Cho
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, 37673, Korea.
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12
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Abstract
Organic (opto)electronic materials have received considerable attention due to their applications in thin-film-transistors, light-emitting diodes, solar cells, sensors, photorefractive devices, and many others. The technological promises include low cost of these materials and the possibility of their room-temperature deposition from solution on large-area and/or flexible substrates. The article reviews the current understanding of the physical mechanisms that determine the (opto)electronic properties of high-performance organic materials. The focus of the review is on photoinduced processes and on electronic properties important for optoelectronic applications relying on charge carrier photogeneration. Additionally, it highlights the capabilities of various experimental techniques for characterization of these materials, summarizes top-of-the-line device performance, and outlines recent trends in the further development of the field. The properties of materials based both on small molecules and on conjugated polymers are considered, and their applications in organic solar cells, photodetectors, and photorefractive devices are discussed.
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Affiliation(s)
- Oksana Ostroverkhova
- Department of Physics, Oregon State University , Corvallis, Oregon 97331, United States
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13
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Kurpiers J, Neher D. Dispersive Non-Geminate Recombination in an Amorphous Polymer:Fullerene Blend. Sci Rep 2016; 6:26832. [PMID: 27225584 PMCID: PMC4881019 DOI: 10.1038/srep26832] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 05/10/2016] [Indexed: 11/16/2022] Open
Abstract
Recombination of free charge is a key process limiting the performance of solar cells. For low mobility materials, such as organic semiconductors, the kinetics of non-geminate recombination (NGR) is strongly linked to the motion of charges. As these materials possess significant disorder, thermalization of photogenerated carriers in the inhomogeneously broadened density of state distribution is an unavoidable process. Despite its general importance, knowledge about the kinetics of NGR in complete organic solar cells is rather limited. We employ time delayed collection field (TDCF) experiments to study the recombination of photogenerated charge in the high-performance polymer:fullerene blend PCDTBT:PCBM. NGR in the bulk of this amorphous blend is shown to be highly dispersive, with a continuous reduction of the recombination coefficient throughout the entire time scale, until all charge carriers have either been extracted or recombined. Rapid, contact-mediated recombination is identified as an additional loss channel, which, if not properly taken into account, would erroneously suggest a pronounced field dependence of charge generation. These findings are in stark contrast to the results of TDCF experiments on photovoltaic devices made from ordered blends, such as P3HT:PCBM, where non-dispersive recombination was proven to dominate the charge carrier dynamics under application relevant conditions.
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Affiliation(s)
- Jona Kurpiers
- Institute of Physics and Astronomy, Soft Matter Physics, University of Potsdam, D-14476 Potsdam, Germany
| | - Dieter Neher
- Institute of Physics and Astronomy, Soft Matter Physics, University of Potsdam, D-14476 Potsdam, Germany
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14
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Corani A, Li MH, Shen PS, Chen P, Guo TF, El Nahhas A, Zheng K, Yartsev A, Sundström V, Ponseca CS. Ultrafast Dynamics of Hole Injection and Recombination in Organometal Halide Perovskite Using Nickel Oxide as p-Type Contact Electrode. J Phys Chem Lett 2016; 7:1096-101. [PMID: 26942559 DOI: 10.1021/acs.jpclett.6b00238] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
There is a mounting effort to use nickel oxide (NiO) as p-type selective electrode for organometal halide perovskite-based solar cells. Recently, an overall power conversion efficiency using this hole acceptor has reached 18%. However, ultrafast spectroscopic investigations on the mechanism of charge injection as well as recombination dynamics have yet to be studied and understood. Using time-resolved terahertz spectroscopy, we show that hole transfer is complete on the subpicosecond time scale, driven by the favorable band alignment between the valence bands of perovskite and NiO nanoparticles (NiO(np)). Recombination time between holes injected into NiO(np) and mobile electrons in the perovskite material is shown to be hundreds of picoseconds to a few nanoseconds. Because of the low conductivity of NiO(np), holes are pinned at the interface, and it is electrons that determine the recombination rate. This recombination competes with charge collection and therefore must be minimized. Doping NiO to promote higher mobility of holes is desirable in order to prevent back recombination.
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Affiliation(s)
- Alice Corani
- Division of Chemical Physics, Lund University , Box 124, 221 00 Lund, Sweden
| | - Ming-Hsien Li
- Department of Photonics, National Cheng Kung University , Tainan, Taiwan 701
| | - Po-Shen Shen
- Department of Photonics, National Cheng Kung University , Tainan, Taiwan 701
| | - Peter Chen
- Department of Photonics, National Cheng Kung University , Tainan, Taiwan 701
- Research Center for Energy Technology and Strategy (RCETS), Tainan, Taiwan 701
- Advanced Optoelectronic Technology Center (AOTC), Tainan, Taiwan 701
| | - Tzung-Fang Guo
- Department of Photonics, National Cheng Kung University , Tainan, Taiwan 701
- Research Center for Energy Technology and Strategy (RCETS), Tainan, Taiwan 701
- Advanced Optoelectronic Technology Center (AOTC), Tainan, Taiwan 701
| | - Amal El Nahhas
- Division of Chemical Physics, Lund University , Box 124, 221 00 Lund, Sweden
| | - Kaibo Zheng
- Division of Chemical Physics, Lund University , Box 124, 221 00 Lund, Sweden
| | - Arkady Yartsev
- Division of Chemical Physics, Lund University , Box 124, 221 00 Lund, Sweden
| | - Villy Sundström
- Division of Chemical Physics, Lund University , Box 124, 221 00 Lund, Sweden
| | - Carlito S Ponseca
- Division of Chemical Physics, Lund University , Box 124, 221 00 Lund, Sweden
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15
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Ponseca CS, Sundström V. Revealing the ultrafast charge carrier dynamics in organo metal halide perovskite solar cell materials using time resolved THz spectroscopy. NANOSCALE 2016; 8:6249-6257. [PMID: 26763720 DOI: 10.1039/c5nr08622a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Ultrafast charge carrier dynamics in organo metal halide perovskite has been probed using time resolved terahertz (THz) spectroscopy (TRTS). Current literature on its early time characteristics is unanimous: sub-ps charge carrier generation, highly mobile charges and very slow recombination rationalizing the exceptionally high power conversion efficiency for a solution processed solar cell material. Electron injection from MAPbI3 to nanoparticles (NP) of TiO2 is found to be sub-ps while Al2O3 NPs do not alter charge dynamics. Charge transfer to organic electrodes, Spiro-OMeTAD and PCBM, is sub-ps and few hundreds of ps respectively, which is influenced by the alignment of energy bands. It is surmised that minimizing defects/trap states is key in optimizing charge carrier extraction from these materials.
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Affiliation(s)
- C S Ponseca
- Division of Chemical Physics, Lund University, Getingevagen 60, Lund, Sweden.
| | - V Sundström
- Division of Chemical Physics, Lund University, Getingevagen 60, Lund, Sweden.
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16
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Ponseca CS, Tian Y, Sundström V, Scheblykin IG. Excited state and charge-carrier dynamics in perovskite solar cell materials. NANOTECHNOLOGY 2016; 27:082001. [PMID: 26820442 DOI: 10.1088/0957-4484/27/8/082001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Organo-metal halide perovskites (OMHPs) have attracted enormous interest in recent years as materials for application in optoelectronics and solar energy conversion. These hybrid semiconductors seem to have the potential to challenge traditional silicon technology. In this review we will give an account of the recent development in the understanding of the fundamental light-induced processes in OMHPs from charge-photo generation, migration of charge carries through the materials and finally their recombination. Our and other literature reports on time-resolved conductivity, transient absorption and photoluminescence properties are used to paint a picture of how we currently see the fundamental excited state and charge-carrier dynamics. We will also show that there is still no fully coherent picture of the processes in OMHPs and we will indicate the problems to be solved by future research.
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17
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Cunningham PD, Lane PA, Melinger JS, Esenturk O, Heilweil EJ. Probing Charge Transfer and Hot Carrier Dynamics in Organic Solar Cells with Terahertz Spectroscopy. PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2016. [PMID: 28649166 DOI: 10.1117/12.2228379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Time-resolved terahertz spectroscopy (TRTS) was used to explore charge generation, transfer, and the role of hot carriers in organic solar cell materials. Two model molecular photovoltaic systems were investigated: with zinc phthalocyanine (ZnPc) or alpha-sexathiophene (α-6T) as the electron donors and buckminsterfullerene (C60) as the electron acceptor. TRTS provides charge carrier conductivity dynamics comprised of changes in both population and mobility. By using time-resolved optical spectroscopy in conjunction with TRTS, these two contributions can be disentangled. The sub-picosecond photo-induced conductivity decay dynamics of C60 were revealed to be caused by auto-ionization: the intrinsic process by which charge is generated in molecular solids. In donor-acceptor blends, the long-lived photo-induced conductivity is used for weight fraction optimization of the constituents. In nanoscale multilayer films, the photo-induced conductivity identifies optimal layer thicknesses. In films of ZnPc/C60, electron transfer from ZnPc yields hot charges that localize and become less mobile as they thermalize. Excitation of high-lying Franck Condon states in C60 followed by hole-transfer to ZnPc similarly produces hot charge carriers that self-localize; charge transfer clearly precedes carrier cooling. This picture is contrasted to charge transfer in α-6T/C60, where hole transfer takes place from a thermalized state and produces equilibrium carriers that do not show characteristic signs of cooling and self-localization. These results illustrate the value of terahertz spectroscopic methods for probing charge transfer reactions.
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Affiliation(s)
| | - Paul A Lane
- U.S. Naval Research Laboratory, Washington, DC 20375, United States
| | | | - Okan Esenturk
- Chemistry Department, Middle East Technical University, Ankara, Turkey
| | - Edwin J Heilweil
- National Institute of Standards and Technology, Gaithersburg, MD 20899, United States
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Melianas A, Etzold F, Savenije TJ, Laquai F, Inganäs O, Kemerink M. Photo-generated carriers lose energy during extraction from polymer-fullerene solar cells. Nat Commun 2015; 6:8778. [PMID: 26537357 PMCID: PMC4659933 DOI: 10.1038/ncomms9778] [Citation(s) in RCA: 93] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 10/01/2015] [Indexed: 11/23/2022] Open
Abstract
In photovoltaic devices, the photo-generated charge carriers are typically assumed to be in thermal equilibrium with the lattice. In conventional materials, this assumption is experimentally justified as carrier thermalization completes before any significant carrier transport has occurred. Here, we demonstrate by unifying time-resolved optical and electrical experiments and Monte Carlo simulations over an exceptionally wide dynamic range that in the case of organic photovoltaic devices, this assumption is invalid. As the photo-generated carriers are transported to the electrodes, a substantial amount of their energy is lost by continuous thermalization in the disorder broadened density of states. Since thermalization occurs downward in energy, carrier motion is boosted by this process, leading to a time-dependent carrier mobility as confirmed by direct experiments. We identify the time and distance scales relevant for carrier extraction and show that the photo-generated carriers are extracted from the operating device before reaching thermal equilibrium.
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Affiliation(s)
- Armantas Melianas
- Biomolecular and Organic Electronics, Department of Physics, Chemistry and Biology, Linköping University, 58183 Linköping, Sweden
| | - Fabian Etzold
- Max Planck Research Group for Organic Optoelectronics, Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz 55128, Germany
| | - Tom J. Savenije
- Optoelectronic Materials Section, Department of Chemical Engineering, Delft University of Technology, 2628 BL Delft, The Netherlands
| | - Frédéric Laquai
- Max Planck Research Group for Organic Optoelectronics, Max Planck Institute for Polymer Research, Ackermannweg 10, Mainz 55128, Germany
- Physical Sciences and Engineering Division, Material Science and Engineering, Solar and Photovoltaics Engineering Research Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Olle Inganäs
- Biomolecular and Organic Electronics, Department of Physics, Chemistry and Biology, Linköping University, 58183 Linköping, Sweden
| | - Martijn Kemerink
- Complex Materials and Devices, Department of Physics, Chemistry and Biology, Linköping University, 58183 Linköping, Sweden
- Department of Applied Physics, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, The Netherlands
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Iron sensitizer converts light to electrons with 92% yield. Nat Chem 2015; 7:883-9. [DOI: 10.1038/nchem.2365] [Citation(s) in RCA: 172] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 09/02/2015] [Indexed: 12/25/2022]
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Lane PA, Cunningham PD, Melinger JS, Esenturk O, Heilweil EJ. Hot photocarrier dynamics in organic solar cells. Nat Commun 2015; 6:7558. [DOI: 10.1038/ncomms8558] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 05/19/2015] [Indexed: 11/09/2022] Open
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Bässler H, Köhler A. “Hot or cold”: how do charge transfer states at the donor–acceptor interface of an organic solar cell dissociate? Phys Chem Chem Phys 2015; 17:28451-62. [DOI: 10.1039/c5cp04110d] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
This perspective discusses concepts to understand efficient photogeneration of charges in organic semiconductors, with particular emphasis on the role of excess energy.
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Affiliation(s)
- Heinz Bässler
- Bayreuth Institute of Macromolecular Research
- Universität Bayreuth
- 95440 Bayreuth
- Germany
| | - Anna Köhler
- Bayreuth Institute of Macromolecular Research
- Universität Bayreuth
- 95440 Bayreuth
- Germany
- Experimentalphysik II (Organic Semiconductors)
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22
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Jin Z, Gehrig D, Dyer-Smith C, Heilweil EJ, Laquai F, Bonn M, Turchinovich D. Ultrafast Terahertz Photoconductivity of Photovoltaic Polymer-Fullerene Blends: A Comparative Study Correlated with Photovoltaic Device Performance. J Phys Chem Lett 2014; 5:3662-3668. [PMID: 26278734 DOI: 10.1021/jz501890n] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Ultrafast photoinduced carrier dynamics in prototypical low band gap polymer:fullerene photovoltaic blend films PTB7:PC70BM and P3HT:PC70BM is investigated using ultrafast terahertz (THz) spectroscopy. The subpicosecond and few-picosecond decays of THz-probed photoconductivities for both compounds are observed, attributed to the rapid formation of polaron pairs by exciton-exciton annihilation and subsequent polaron pair annihilation, respectively. The transient THz photoconductivity spectra of PTB7:PC70BM are well described by the Drude-Smith (DS) model, directly yielding the important charge transport parameters such as charge carrier density, momentum scattering time, and effective localization. By comparison with P3HT:PC70BM, we find that in PTB7:PC70BM the mobile charge carrier photoconductivity is significantly enhanced by a factor of 1.8 and prevails for longer times after charge formation, due to both improved mobile charge carrier yield and lower charge localization. In PTB7:PC70BM, a strong dependency of electron momentum scattering time on electron density was found, well parametrized by the empirical Caughey-Thomas model. The difference in ultrafast photoconductivities of both P3HT:PC70BM and PTB7:PC70BM is found to correlate very well with the performance of photovoltaic devices based on those materials.
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Affiliation(s)
- Zuanming Jin
- †Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Dominik Gehrig
- †Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Clare Dyer-Smith
- †Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Edwin J Heilweil
- ‡NIST - National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
| | - Frédéric Laquai
- †Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Mischa Bonn
- †Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Dmitry Turchinovich
- †Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
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Pranculis V, Infahsaeng Y, Tang Z, Devižis A, Vithanage DA, Ponseca CS, Inganäs O, Yartsev AP, Gulbinas V, Sundström V. Charge carrier generation and transport in different stoichiometry APFO3:PC61BM solar cells. J Am Chem Soc 2014; 136:11331-8. [PMID: 25025885 DOI: 10.1021/ja503301m] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
In this paper we studied carrier drift dynamics in APFO3:PC61BM solar cells of varied stoichiometry (2:1, 1:1, and 1:4 APFO3:PC61BM) over a wide time range, from subpicoseconds to microseconds with a combination of ultrafast optical electric field probing and conventional transient integrated photocurrent techniques. Carrier drift and extraction dynamics are strongly stoichiometry dependent: the speed of electron or hole drift increases with higher concentration of PC61BM or polymer, respectively. The electron extraction from a sample with 80% PC61BM takes place during hundreds of picoseconds, but slows down to sub-microseconds in a sample with 33% PC61BM. The hole extraction is less stoichiometry dependent: it varies form sub-nanoseconds to tens of nanoseconds when the PC61BM concentration changes from 33% to 80%. The electron extraction rate correlates with the conversion efficiency of solar cells, leading to the conclusion that fast electron motion is essential for efficient charge carrier separation preventing their geminate recombination.
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Affiliation(s)
- Vytenis Pranculis
- Center for Physical Sciences and Technology , Savanoriu 231, LT-02300 Vilnius, Lithuania
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Amarasinghe Vithanage D, Devižis A, Abramavičius V, Infahsaeng Y, Abramavičius D, MacKenzie RCI, Keivanidis PE, Yartsev A, Hertel D, Nelson J, Sundström V, Gulbinas V. Visualizing charge separation in bulk heterojunction organic solar cells. Nat Commun 2014; 4:2334. [PMID: 23945881 DOI: 10.1038/ncomms3334] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Accepted: 07/22/2013] [Indexed: 11/09/2022] Open
Abstract
Solar cells based on conjugated polymer and fullerene blends have been developed as a low-cost alternative to silicon. For efficient solar cells, electron-hole pairs must separate into free mobile charges that can be extracted in high yield. We still lack good understanding of how, why and when carriers separate against the Coulomb attraction. Here we visualize the charge separation process in bulk heterojunction solar cells by directly measuring charge carrier drift in a polymer:fullerene blend with ultrafast time resolution. We show that initially only closely separated (<1 nm) charge pairs are created and they separate by several nanometres during the first several picoseconds. Charge pairs overcome Coulomb attraction and form free carriers on a subnanosecond time scale. Numerical simulations complementing the experimental data show that fast three-dimensional charge diffusion within an energetically disordered medium, increasing the entropy of the system, is sufficient to drive the charge separation process.
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25
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Ponseca CS, Savenije TJ, Abdellah M, Zheng K, Yartsev A, Pascher T, Harlang T, Chabera P, Pullerits T, Stepanov A, Wolf JP, Sundström V. Organometal Halide Perovskite Solar Cell Materials Rationalized: Ultrafast Charge Generation, High and Microsecond-Long Balanced Mobilities, and Slow Recombination. J Am Chem Soc 2014; 136:5189-92. [DOI: 10.1021/ja412583t] [Citation(s) in RCA: 977] [Impact Index Per Article: 97.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Carlito S. Ponseca
- Division
of Chemical Physics, Lund University, Box 124, 221 00 Lund, Sweden
| | - Tom J. Savenije
- Department
of Chemical Engineering, Delft University of Technology, 2628 BL Delft, The Netherlands
| | - Mohamed Abdellah
- Division
of Chemical Physics, Lund University, Box 124, 221 00 Lund, Sweden
- Department
of Chemistry, Qena Faculty of Science, South Valley University, Qena 83523, Egypt
| | - Kaibo Zheng
- Division
of Chemical Physics, Lund University, Box 124, 221 00 Lund, Sweden
| | - Arkady Yartsev
- Division
of Chemical Physics, Lund University, Box 124, 221 00 Lund, Sweden
| | - Tobjörn Pascher
- Division
of Chemical Physics, Lund University, Box 124, 221 00 Lund, Sweden
| | - Tobias Harlang
- Division
of Chemical Physics, Lund University, Box 124, 221 00 Lund, Sweden
| | - Pavel Chabera
- Division
of Chemical Physics, Lund University, Box 124, 221 00 Lund, Sweden
| | - Tonu Pullerits
- Division
of Chemical Physics, Lund University, Box 124, 221 00 Lund, Sweden
| | - Andrey Stepanov
- GAP-Biophotonics, University of Geneva, 1211 Geneva 4, Switzerland
| | - Jean-Pierre Wolf
- GAP-Biophotonics, University of Geneva, 1211 Geneva 4, Switzerland
| | - Villy Sundström
- Division
of Chemical Physics, Lund University, Box 124, 221 00 Lund, Sweden
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Burke TM, McGehee MD. How high local charge carrier mobility and an energy cascade in a three-phase bulk heterojunction enable >90% quantum efficiency. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2014; 26:1923-1928. [PMID: 24375640 DOI: 10.1002/adma.201304241] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Revised: 10/11/2013] [Indexed: 05/28/2023]
Abstract
Charge generation in champion organic solar cells is highly efficient in spite of low bulk charge-carrier mobilities and short geminate-pair lifetimes. In this work, kinetic Monte Carlo simulations are used to understand efficient charge generation in terms of experimentally measured high local charge-carrier mobilities and energy cascades due to molecular mixing.
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Affiliation(s)
- Timothy M Burke
- Stanford University, 476 Lomita Mall, Stanford, CA, 94305, USA
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27
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Andersson LM, Melianas A, Infahasaeng Y, Tang Z, Yartsev A, Inganäs O, Sundström V. Unified Study of Recombination in Polymer:Fullerene Solar Cells Using Transient Absorption and Charge-Extraction Measurements. J Phys Chem Lett 2013; 4:2069-2072. [PMID: 26283254 DOI: 10.1021/jz4009745] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Recombination in the well-performing bulk heterojunction solar cell blend between the conjugated polymer TQ-1 and the substituted fullerene PCBM has been investigated with pump-probe transient absorption and charge extraction of photogenerated carriers (photo-CELIV). Both methods are shown to generate identical and overlapping data under appropriate experimental conditions. The dominant type of recombination is bimolecular with a rate constant of 7 × 10(-12) cm(-3) s(-1). This recombination rate is shown to be fully consistent with solar cell performance. Deviations from an ideal bimolecular recombination process, in this material system only observable at high pump fluences, are explained with a time-dependent charge-carrier mobility, and the implications of such a behavior for device development are discussed.
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Affiliation(s)
- L Mattias Andersson
- †Chemical Physics, Lund University, P.O. Box 124, SE-22100 Lund, Sweden
- ‡Biomolecular and Organic Electronics, Department of Physics Chemistry and Biology (IFM), Linköping University, SE-58183 Linköping, Sweden
| | - Armantas Melianas
- ‡Biomolecular and Organic Electronics, Department of Physics Chemistry and Biology (IFM), Linköping University, SE-58183 Linköping, Sweden
| | | | - Zheng Tang
- ‡Biomolecular and Organic Electronics, Department of Physics Chemistry and Biology (IFM), Linköping University, SE-58183 Linköping, Sweden
| | - Arkady Yartsev
- †Chemical Physics, Lund University, P.O. Box 124, SE-22100 Lund, Sweden
| | - Olle Inganäs
- ‡Biomolecular and Organic Electronics, Department of Physics Chemistry and Biology (IFM), Linköping University, SE-58183 Linköping, Sweden
| | - Villy Sundström
- †Chemical Physics, Lund University, P.O. Box 124, SE-22100 Lund, Sweden
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Vukmirović N. A comparative study of electronic properties of disordered conjugated polymers. Phys Chem Chem Phys 2013; 15:3543-51. [DOI: 10.1039/c3cp43115k] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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29
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Ponseca CS, Němec H, Vukmirović N, Fusco S, Wang E, Andersson MR, Chabera P, Yartsev A, Sundström V. Electron and Hole Contributions to the Terahertz Photoconductivity of a Conjugated Polymer:Fullerene Blend Identified. J Phys Chem Lett 2012; 3:2442-2446. [PMID: 26292130 DOI: 10.1021/jz301013u] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Time-resolved terahertz spectroscopy was employed for the investigation of charge-transport dynamics in benzothiadiazolo-dithiophene polyfluorene ([2,7-(9,9-dioctyl-fluorene)-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)]) (APFO-3) polymers with various chain lengths and in its monomer form, all blended with an electron acceptor ([6,6]-phenyl-C61-butyric acid methyl ester, PCBM). Upon photoexcitation, charged polaron pairs are created, negative charges are transferred to fullerenes, while positive polarons remain on polymers/monomers. Vastly different hole mobility in polymer and monomer blends allows us to distinguish the hole and electron contributions to the carrier mobility.
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Affiliation(s)
- Carlito S Ponseca
- †Division of Chemical Physics, Lund University, Box 124, 221 00 Lund, Sweden
| | - Hynek Němec
- ‡Institute of Physics, Academy of Sciences of the Czech Republic, 182 21 Prague, Czech Republic
| | - Nenad Vukmirović
- §Scientific Computing Laboratory, Institute of Physics Belgrade, University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia
| | - Sandra Fusco
- ∥Department of Chemical and Biological Engineering, Chalmers University of Technology, 412 96 Göteborg, Sweden
| | - Ergang Wang
- ∥Department of Chemical and Biological Engineering, Chalmers University of Technology, 412 96 Göteborg, Sweden
| | - Mats R Andersson
- ∥Department of Chemical and Biological Engineering, Chalmers University of Technology, 412 96 Göteborg, Sweden
| | - Pavel Chabera
- †Division of Chemical Physics, Lund University, Box 124, 221 00 Lund, Sweden
| | - Arkady Yartsev
- †Division of Chemical Physics, Lund University, Box 124, 221 00 Lund, Sweden
| | - Villy Sundström
- †Division of Chemical Physics, Lund University, Box 124, 221 00 Lund, Sweden
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