1
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Li S, Nishikubo R, Saeki A. Combined Charge Extraction by Linearly Increasing Voltage and Time-Resolved Microwave Conductivity to Reveal the Dynamic Charge Carrier Mobilities in Thin-Film Organic Solar Cells. ACS OMEGA 2024; 9:26951-26962. [PMID: 38947799 PMCID: PMC11209900 DOI: 10.1021/acsomega.3c09977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 05/22/2024] [Accepted: 06/05/2024] [Indexed: 07/02/2024]
Abstract
This article reports a purely experiment-based method to evaluate the time-dependent charge carrier mobilities in thin-film organic solar cells (OSCs) using simultaneous charge extraction by linearly increasing the voltage (CELIV) and time-resolved microwave conductivity (TRMC) measurements. This method enables the separate measurement of electron mobility (μe) and hole mobility (μh) in a metal-insulator-semiconductor (MIS) device. A slope-injection-restoration voltage profile for MIS-CELIV is also proposed to accurately determine the charge densities. The dynamic behavior of μe and μh is examined in five bulk heterojunction (BHJ) OSCs of polymer:fullerene (P3HT:PCBM and PffBT4T:PCBM) and polymer:nonfullerene acceptor (PM6:ITIC, PM6:IT4F, and PM6:Y6). While the former exhibits fast decays of μh and μe, the latter, in particular, PM6:IT4F and PM6:Y6, exhibits slow decays. Notably, the high-performing PM6:Y6 demonstrates both a balanced mobility (μe/μh) of 1.0-1.1 within 30 μs and relatively large CELIV-TRMC mobility values among the five BHJs. The results exhibit reasonable consistency with a high fill factor. The proposed new CELIV-TRMC technique offers a path toward a comprehensive understanding of dynamic mobility and its correlation with the OSC performance.
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Affiliation(s)
- Shaoxian Li
- Department
of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Ryosuke Nishikubo
- Department
of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
- Innovative
Catalysis Science Division (ICS), Institute for Open and Transdisciplinary
Research Initiatives (OTRI), Osaka University, 1-1 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
- Innovative
Catalysis Science Division (ICS), Institute for Open and Transdisciplinary
Research Initiatives (OTRI), Osaka University, 1-1 Yamadaoka, Suita, Osaka 565-0871, Japan
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2
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Franco LR, Marchiori C, Araujo CM. Unveiling the impact of exchange-correlation functionals on the description of key electronic properties of non-fullerene acceptors in organic photovoltaics. J Chem Phys 2023; 159:204110. [PMID: 38018752 DOI: 10.1063/5.0163180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 10/30/2023] [Indexed: 11/30/2023] Open
Abstract
Non-fullerene electron acceptors have emerged as promising alternatives to traditional electron-acceptors in the active layers of organic photovoltaics. This is due to their tunable energy levels, optical response in the visible light spectrum, high electron mobility, and photochemical stability. In this study, the electronic properties of two representative non-fullerene acceptors, ITIC and Y5, have been calculated within the framework of density functional theory using a range of hybrid and non-hybrid density functionals. Screened range-separated hybrid (SRSH) approaches were also tested. The results are analyzed in light of the previously reported experimental outcomes. Specifically, we have calculated the oxidation and reduction potentials, fundamental and optical gaps, the highest occupied molecular orbital and lowest unoccupied molecular orbital energies, and exciton binding energies. Additionally, we have investigated the effects of the medium dielectric constant on these properties employing a universal implicit solvent model. It was found that hybrid functionals generally perform poorly in predicting oxidation potentials, while non-hybrid functionals tend to overestimate reduction potentials. The inclusion of a large Hartree-Fock contribution to the global or long range was identified as the source of inaccuracy for many hybrid functionals in predicting both redox potentials and the fundamental and optical gaps. Corroborating with the available literature, ∼50% of all tested functionals predicted very small exciton binding energies, within the range of ±0.1 eV, that become even smaller by increasing the dielectric constant of the material. Finally, the OHSE2PBE and tHCTHhyb functionals and the optimal tuning SRSH approach emerged as the best-performing methods, with good accuracy in the description of the electronic properties of interest.
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Affiliation(s)
- Leandro R Franco
- Department of Engineering and Physics, Karlstad University, 65188 Karlstad, Sweden
| | - Cleber Marchiori
- Department of Engineering and Physics, Karlstad University, 65188 Karlstad, Sweden
| | - C Moyses Araujo
- Department of Engineering and Physics, Karlstad University, 65188 Karlstad, Sweden
- Materials Theory Division, Department of Physics and Astronomy, Uppsala University, 75120 Uppsala, Sweden
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3
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Peng D, Zhang Z, Zhang J, Yang Y. Improving Photocatalytic Activity for Formaldehyde Degradation by Encapsulating C 60 Fullerenes into Graphite-like C 3N 4 through the Enhancement of Built-in Electric Fields. Molecules 2023; 28:5815. [PMID: 37570785 PMCID: PMC10420677 DOI: 10.3390/molecules28155815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 07/07/2023] [Accepted: 07/26/2023] [Indexed: 08/13/2023] Open
Abstract
The photocatalytic degradation of formaldehyde by graphite-like C3N4 is one of the most attractive and environmentally friendly strategies to address the significant threat to human health posed by indoor air pollutants. Despite its potential, this degradation process still faces issues with suboptimal efficiency, which may be attributed to the rapid recombination of photogenerated excitons and the broad band gap. As a proof of concept, a series of graphite-like C3N4@C60 composites combining graphite-like C3N4 and C60 was developed via an in situ generation strategy. The obtained graphite-like C3N4@C60 composites exhibited a remarkable increase in the photocatalytic degradation efficiency of formaldehyde, of up to 99%, under visible light irradiation, outperforming pure graphite-like C3N4 and C60. This may be due to the composites' enhanced built-in electric field. Additionally, the proposed composites maintained a formaldehyde removal efficiency of 84% even after six cycles, highlighting their potential for indoor air purification and paving the way for the development of efficient photocatalysts.
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Affiliation(s)
- Dongmei Peng
- College of Furniture and Art Design, Central South University of Forestry and Technology, Changsha 410000, China; (D.P.); (J.Z.); (Y.Y.)
- Green Furniture Engineering Technology Research Center, National Forestry & Grassland Administration, Changsha 410004, China
- Green Home Engineering Technology Research Center, Changsha 410004, China
| | - Zhongfeng Zhang
- College of Furniture and Art Design, Central South University of Forestry and Technology, Changsha 410000, China; (D.P.); (J.Z.); (Y.Y.)
- Green Furniture Engineering Technology Research Center, National Forestry & Grassland Administration, Changsha 410004, China
- Green Home Engineering Technology Research Center, Changsha 410004, China
| | - Jijuan Zhang
- College of Furniture and Art Design, Central South University of Forestry and Technology, Changsha 410000, China; (D.P.); (J.Z.); (Y.Y.)
- Green Furniture Engineering Technology Research Center, National Forestry & Grassland Administration, Changsha 410004, China
- Green Home Engineering Technology Research Center, Changsha 410004, China
| | - Yang Yang
- College of Furniture and Art Design, Central South University of Forestry and Technology, Changsha 410000, China; (D.P.); (J.Z.); (Y.Y.)
- Green Furniture Engineering Technology Research Center, National Forestry & Grassland Administration, Changsha 410004, China
- Green Home Engineering Technology Research Center, Changsha 410004, China
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4
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Ji Y, Mu X, Yin H, Cui B, Hao X, Gao K. Revealing the Role of Donor/Acceptor Interfaces in Nonfullerene-Acceptor Based Organic Solar Cells: Charge Separation versus Recombination. J Phys Chem Lett 2023; 14:3811-3817. [PMID: 37057899 DOI: 10.1021/acs.jpclett.3c00282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Organic solar cells (OSCs) based on nonfullerene-acceptors (NFAs) have achieved rapid development, while the role of donor/acceptor (D/A) interfaces in NFA based heterosystems has not been fully addressed. Here, we clarify that the photoinduced spontaneous charge separation efficiency in typical NFA heterosystems can reach up to 67%, and the charge separation efficiency contributed by the D/A interface is only 25%. The more important role of D/A interfaces is reducing the charge recombination rate, especially optimizing the competition between radiative and nonradiative charge recombination, thus reducing the nonradiative voltage loss. Systematical simulations demonstrate that there exists an optimal interfacial distance for a fixed energy offset, at which the D/A interface can reduce the nonradiative voltage loss by a maximum value of 0.12 V. Hence, we propose that optimizing the interfacial distance combined with the actual interfacial energy offset of a given heterosystem is important to develop its best photovoltaic performance.
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Affiliation(s)
- Yiwen Ji
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
| | - Xinyu Mu
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
| | - Hang Yin
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
| | - Bin Cui
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
| | - Xiaotao Hao
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
| | - Kun Gao
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
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5
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Unraveling complex performance-limiting factors of brominated ITIC derivative: PM6 organic solar cells by using time-resolved measurements. Polym J 2022. [DOI: 10.1038/s41428-022-00704-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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6
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Chen B, Miao W, Zhou A, Wang Q, Guo P, Xia Y. Synthesis and Characterization of Dialkylthio Side Chains Modified Benzo[1,2‐b:4,5‐b’]dithiophene‐Based Conjugated Polymer for Organic Solar Cells. ChemistrySelect 2022. [DOI: 10.1002/slct.202202325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Bin Chen
- Gansu Province Organic Semiconductor Materials and Applied Technology Research Center School of Material Science and Engineering Lanzhou Jiaotong University Lanzhou 730070 PR China
- College of Petroleum and Chemical Engineering Jilin Institute of Chemical Technology Jilin 432000 P. R. China
- Key Lab of Opt-Electronic Technology and Intelligent Control of Ministry of Education Lanzhou Jiaotong University Lanzhou 730070 PR China
| | - Wentao Miao
- Gansu Province Organic Semiconductor Materials and Applied Technology Research Center School of Material Science and Engineering Lanzhou Jiaotong University Lanzhou 730070 PR China
| | - Anqi Zhou
- Gansu Province Organic Semiconductor Materials and Applied Technology Research Center School of Material Science and Engineering Lanzhou Jiaotong University Lanzhou 730070 PR China
| | - Qian Wang
- Gansu Province Organic Semiconductor Materials and Applied Technology Research Center School of Material Science and Engineering Lanzhou Jiaotong University Lanzhou 730070 PR China
| | - Pengzhi Guo
- Gansu Province Organic Semiconductor Materials and Applied Technology Research Center School of Material Science and Engineering Lanzhou Jiaotong University Lanzhou 730070 PR China
- Gansu Province Organic Semiconductor Materials and Applied Technology Research Centre Lanzhou Jiaotong University Lanzhou 730070 PR China
| | - Yangjun Xia
- Gansu Province Organic Semiconductor Materials and Applied Technology Research Center School of Material Science and Engineering Lanzhou Jiaotong University Lanzhou 730070 PR China
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7
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Deng J, Huang B, Li W, Zhang L, Jeong SY, Huang S, Zhang S, Wu F, Xu X, Zou G, Woo HY, Chen Y, Chen L. Ferroelectric Polymer Drives Performance Enhancement of Non-fullerene Organic Solar Cells. Angew Chem Int Ed Engl 2022; 61:e202202177. [PMID: 35383399 DOI: 10.1002/anie.202202177] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Indexed: 12/19/2022]
Abstract
Enhancing the built-in electric field to promote charge dynamitic process is of great significance to boost the performance of the non-fullerene organic solar cells (OSCs), which has rarely been concerned. In this work, we introduced a cheap ferroelectric polymer as an additive into the active layers of non-fullerene OSCs to improve the device performance. An additional and permanent electrical field was produced by the polarization of the ferroelectric dipoles, which can substantially enhance the built-in electric field. The promoted exciton separation, significantly accelerated charge transport, reduced the charge recombination, as well as the optimized film morphology were observed in the device, leading to a significantly improved performance of the PVDF-modified OSCs with various active layers, such as PM6 : Y6, PM6 : BTP-eC9, PM6 : IT-4F and PTB7-Th : Y6. Especially, a record efficiency of 17.72 % for PM6 : Y6-based OSC and an outstanding efficiency of 18.17 % for PM6 : BTP-eC9-based OSC were achieved.
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Affiliation(s)
- Jiawei Deng
- School of Chemistry and Chemical Engineering/Institute of Polymers and Energy Chemistry (IPEC), Nanchang University, 999 Xuefu Avenue, Nanchang, 330031, China
| | - Bin Huang
- School of Metallurgical and Chemical Engineering, Jiangxi University of Science and Technology, 156 Ke Jia Road, Ganzhou, 341000, China
| | - Wenhao Li
- Department of Materials Science, Fudan University, Songhu Road, Shanghai, 200438, China
| | - Lifu Zhang
- School of Chemistry and Chemical Engineering/Institute of Polymers and Energy Chemistry (IPEC), Nanchang University, 999 Xuefu Avenue, Nanchang, 330031, China
| | - Sang Young Jeong
- Department of Chemistry College of Science, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea
| | - Shaorong Huang
- School of Chemistry and Chemical Engineering/Institute of Polymers and Energy Chemistry (IPEC), Nanchang University, 999 Xuefu Avenue, Nanchang, 330031, China
| | - Shijing Zhang
- School of Chemistry and Chemical Engineering/Institute of Polymers and Energy Chemistry (IPEC), Nanchang University, 999 Xuefu Avenue, Nanchang, 330031, China
| | - Feiyan Wu
- School of Chemistry and Chemical Engineering/Institute of Polymers and Energy Chemistry (IPEC), Nanchang University, 999 Xuefu Avenue, Nanchang, 330031, China
| | - Xiaoli Xu
- College of Energy, Soochow Institute for Energy and Materials InnovationS, and Key Laboratory of Advanced Carbon Materials and Wearable Energy Soochow University, Suzhou, 215006, China
| | - Guifu Zou
- College of Energy, Soochow Institute for Energy and Materials InnovationS, and Key Laboratory of Advanced Carbon Materials and Wearable Energy Soochow University, Suzhou, 215006, China
| | - Han Young Woo
- Department of Chemistry College of Science, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea
| | - Yiwang Chen
- School of Chemistry and Chemical Engineering/Institute of Polymers and Energy Chemistry (IPEC), Nanchang University, 999 Xuefu Avenue, Nanchang, 330031, China.,Institute of Advanced Scientific Research (iASR)/Key Laboratory of Functional Organic Small Molecules for Ministry of Education, Jiangxi Normal University, 99 Ziyang Avenue, Nanchang, 330022, China
| | - Lie Chen
- School of Chemistry and Chemical Engineering/Institute of Polymers and Energy Chemistry (IPEC), Nanchang University, 999 Xuefu Avenue, Nanchang, 330031, China
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8
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Rousseva S, Raul BAL, van Kooij FS, Kuevda AV, Birudula S, Hummelen JC, Pshenichnikov MS, Chiechi RC. Investigating the dielectric properties and exciton diffusion in C 70 derivatives. Phys Chem Chem Phys 2022; 24:13763-13772. [PMID: 35612289 DOI: 10.1039/d2cp00791f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In recent years, the dielectric constant (εr) of organic semiconductors (OSCs) has been of interest in the organic photovoltaic (OPV) community due to its potential influence on the exciton binding energy. Despite progress in the design of high εr OSCs and the accurate measurement of the εr, the effects of the synthetic strategies on specific (opto)electronic properties of the OSCs remain uncertain. In this contribution, the effects of εr on the optical properties of five new C70 derivatives and [70]PCBM are investigated. Together with [70]PCBM, the derivatives have a range of εr values that depend on the polarity and length of the side chains. The properties of the singlet excitons are investigated in detail with steady-state and time-resolved spectroscopy and the exciton diffusion length is measured. All six derivatives show similar photophysical properties in the neat films. However, large differences in the crystallinity of the fullerene films influence the exciton dynamics in blend films. This work shows that design principles for OSCs with a higher εr can have a very different influence on the performance of traditional BHJ devices and in neat films and it is important to consider the neat film properties when investigating the optoelectronic properties of new materials for OPV.
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Affiliation(s)
- Sylvia Rousseva
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.,Zernike Institute for Advanced Materials, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
| | - Benedito A L Raul
- Zernike Institute for Advanced Materials, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
| | - Felien S van Kooij
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.,Zernike Institute for Advanced Materials, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
| | - Alexey V Kuevda
- Zernike Institute for Advanced Materials, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
| | - Srikanth Birudula
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.,Zernike Institute for Advanced Materials, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
| | - Jan C Hummelen
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.,Zernike Institute for Advanced Materials, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
| | - Maxim S Pshenichnikov
- Zernike Institute for Advanced Materials, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
| | - Ryan C Chiechi
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.,Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, USA.
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9
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Deng J, Huang B, Li W, Zhang L, Jeong SY, Huang S, Zhang S, Wu F, Xu X, Zou G, Woo HY, Chen Y, Chen L. Ferroelectric Polymer Drives Performance Enhancement of Non‐fullerene Organic Solar Cells. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202202177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Jiawei Deng
- School of Chemistry and Chemical Engineering/Institute of Polymers and Energy Chemistry (IPEC) Nanchang University 999 Xuefu Avenue Nanchang 330031 China
| | - Bin Huang
- School of Metallurgical and Chemical Engineering Jiangxi University of Science and Technology 156 Ke Jia Road Ganzhou 341000 China
| | - Wenhao Li
- Department of Materials Science Fudan University Songhu Road Shanghai 200438 China
| | - Lifu Zhang
- School of Chemistry and Chemical Engineering/Institute of Polymers and Energy Chemistry (IPEC) Nanchang University 999 Xuefu Avenue Nanchang 330031 China
| | - Sang Young Jeong
- Department of Chemistry College of Science Korea University 145 Anam-ro Seongbuk-gu, Seoul 02841 Republic of Korea
| | - Shaorong Huang
- School of Chemistry and Chemical Engineering/Institute of Polymers and Energy Chemistry (IPEC) Nanchang University 999 Xuefu Avenue Nanchang 330031 China
| | - Shijing Zhang
- School of Chemistry and Chemical Engineering/Institute of Polymers and Energy Chemistry (IPEC) Nanchang University 999 Xuefu Avenue Nanchang 330031 China
| | - Feiyan Wu
- School of Chemistry and Chemical Engineering/Institute of Polymers and Energy Chemistry (IPEC) Nanchang University 999 Xuefu Avenue Nanchang 330031 China
| | - Xiaoli Xu
- College of Energy Soochow Institute for Energy and Materials InnovationS and Key Laboratory of Advanced Carbon Materials and Wearable Energy Soochow University Suzhou 215006 China
| | - Guifu Zou
- College of Energy Soochow Institute for Energy and Materials InnovationS and Key Laboratory of Advanced Carbon Materials and Wearable Energy Soochow University Suzhou 215006 China
| | - Han Young Woo
- Department of Chemistry College of Science Korea University 145 Anam-ro Seongbuk-gu, Seoul 02841 Republic of Korea
| | - Yiwang Chen
- School of Chemistry and Chemical Engineering/Institute of Polymers and Energy Chemistry (IPEC) Nanchang University 999 Xuefu Avenue Nanchang 330031 China
- Institute of Advanced Scientific Research (iASR)/Key Laboratory of Functional Organic Small Molecules for Ministry of Education Jiangxi Normal University 99 Ziyang Avenue Nanchang 330022 China
| | - Lie Chen
- School of Chemistry and Chemical Engineering/Institute of Polymers and Energy Chemistry (IPEC) Nanchang University 999 Xuefu Avenue Nanchang 330031 China
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10
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Yan Y, Zhang Y, Memon WA, Wang M, Zhang X, Wei Z. The role of entropy gains in the exciton separation in organic solar cells. Macromol Rapid Commun 2022; 43:e2100903. [PMID: 35338684 DOI: 10.1002/marc.202100903] [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: 12/21/2021] [Revised: 02/16/2022] [Indexed: 11/06/2022]
Abstract
In organic solar cell (OSC), the lower dielectric constant of organic semiconductor material induces a strong Coulomb attraction between electron-hole pairs, which leads to a low exciton separation efficiency, especially the charge transfer (CT) state. The CT state formed at the electron-donor (D) and electron-acceptor (A) interface is regarded as an unfavorable property of organic photovoltaic devices. Since the OSC works in a nonzero temperature condition, the entropy effect would be one of the main reasons to overcome the Coulomb energy barrier and must be taken into account. In this review, we review the present understanding of the entropy-driven charge separation and describe how factors such as the dimensionality of the organic semiconductor, energy disorder effect, the morphology of the active layer, and the nonequilibrium effect affect the entropy contribution in compensating the Coulomb dissociation barrier for CT exciton separation and charge generation process. We focus on the investigation of the entropy effect on exciton dissociation mechanism from both theoretical and experimental aspects, which provides pathways for understanding the underlying mechanisms of exciton separation and further enhancing the efficiency of OSCs. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Yangjun Yan
- School of Science, Beijing Jiaotong University, Beijing, 100044, China.,CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Yajie Zhang
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Waqar Ali Memon
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Mengni Wang
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Xinghua Zhang
- School of Science, Beijing Jiaotong University, Beijing, 100044, China
| | - Zhixiang Wei
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
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