1
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Boehm BJ, McNeill CR, Huang DM. Competing single-chain folding and multi-chain aggregation pathways control solution-phase aggregate morphology of organic semiconducting polymers. NANOSCALE 2022; 14:18070-18086. [PMID: 36448546 DOI: 10.1039/d2nr04750k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Understanding the solution-phase behaviour of organic semiconducting polymers is important for systematically improving the performance of devices based on solution-processed thin films of these molecules. Conventional polymer theory predicts that polymer conformations become more compact as solvent quality decreases, but recent experiments have shown the high-performance organic-semiconducting polymer P(NDI2OD-T2) to form extended rod-like aggregates much larger than a single chain in poor solvents, with the formation of these extended aggregates correlated with enhanced electron mobility in films deposited from these solutions. We explain the unexpected formation of extended aggregates using a novel coarse-grained simulation model of P(NDI2OD-T2) that we have developed to study the effect of solvent quality on its solution-phase behaviour. In poor solvents, we find that aggregation through only a few monomers gives effectively inseparable chains, leading to the formation of extended structures of partially overlapping chains via non-equilibrium assembly. This behaviour requires that multi-chain aggregation occurs faster than chain folding, which we show is the case for the chain lengths and concentrations shown experimentally to form rod-like aggregates. This kinetically controlled process introduces a dependence of aggregate structure on concentration, chain length, and chain flexibility, which we show is able to reconcile experimental findings and is generalisable to the solution-phase assembly of other semiflexible polymers.
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Affiliation(s)
- Belinda J Boehm
- Department of Chemistry, School of Physical Sciences, The University of Adelaide, SA 5005, Australia.
| | - Christopher R McNeill
- Department of Materials Science and Engineering, Monash University, Clayton, VIC 3800, Australia
| | - David M Huang
- Department of Chemistry, School of Physical Sciences, The University of Adelaide, SA 5005, Australia.
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2
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Cui Y, Xu Y, Yao H, Bi P, Hong L, Zhang J, Zu Y, Zhang T, Qin J, Ren J, Chen Z, He C, Hao X, Wei Z, Hou J. Single-Junction Organic Photovoltaic Cell with 19% Efficiency. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2102420. [PMID: 34464466 DOI: 10.1002/adma.202102420] [Citation(s) in RCA: 371] [Impact Index Per Article: 123.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 05/24/2021] [Indexed: 05/27/2023]
Abstract
Improving power conversion efficiency (PCE) is important for broadening the applications of organic photovoltaic (OPV) cells. Here, a maximum PCE of 19.0% (certified value of 18.7%) is achieved in single-junction OPV cells by combining material design with a ternary blending strategy. An active layer comprising a new wide-bandgap polymer donor named PBQx-TF and a new low-bandgap non-fullerene acceptor (NFA) named eC9-2Cl is rationally designed. With optimized light utilization, the resulting binary cell exhibits a good PCE of 17.7%. An NFA F-BTA3 is then added to the active layer as a third component to simultaneously improve the photovoltaic parameters. The improved light unitization, cascaded energy level alignment, and enhanced intermolecular packing result in open-circuit voltage of 0.879 V, short-circuit current density of 26.7 mA cm-2 , and fill factor of 0.809. This study demonstrates that further improvement of PCEs of high-performance OPV cells requires fine tuning of the electronic structures and morphologies of the active layers.
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Affiliation(s)
- Yong Cui
- State Key Laboratory of Polymer Physics and Chemistry, Beijing National Laboratory for Molecular Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences, Beijing, 100190, China
| | - Ye Xu
- State Key Laboratory of Polymer Physics and Chemistry, Beijing National Laboratory for Molecular Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences, Beijing, 100190, China
- School of Chemistry and Chemical Engineering, University of Chinses Academy of Sciences, Beijing, 100049, China
| | - Huifeng Yao
- State Key Laboratory of Polymer Physics and Chemistry, Beijing National Laboratory for Molecular Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences, Beijing, 100190, China
| | - Pengqing Bi
- State Key Laboratory of Polymer Physics and Chemistry, Beijing National Laboratory for Molecular Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences, Beijing, 100190, China
| | - Ling Hong
- State Key Laboratory of Polymer Physics and Chemistry, Beijing National Laboratory for Molecular Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences, Beijing, 100190, China
- School of Chemistry and Chemical Engineering, University of Chinses Academy of Sciences, Beijing, 100049, China
| | - Jianqi Zhang
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Yunfei Zu
- State Key Laboratory of Polymer Physics and Chemistry, Beijing National Laboratory for Molecular Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences, Beijing, 100190, China
- School of Chemistry and Chemical Engineering, University of Chinses Academy of Sciences, Beijing, 100049, China
| | - Tao Zhang
- State Key Laboratory of Polymer Physics and Chemistry, Beijing National Laboratory for Molecular Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences, Beijing, 100190, China
| | - Jinzhao Qin
- State Key Laboratory of Polymer Physics and Chemistry, Beijing National Laboratory for Molecular Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences, Beijing, 100190, China
- School of Chemistry and Chemical Engineering, University of Chinses Academy of Sciences, Beijing, 100049, China
| | - Junzhen Ren
- State Key Laboratory of Polymer Physics and Chemistry, Beijing National Laboratory for Molecular Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences, Beijing, 100190, China
| | - Zhihao Chen
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong, 250100, P. R. China
| | - Chang He
- State Key Laboratory of Polymer Physics and Chemistry, Beijing National Laboratory for Molecular Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences, Beijing, 100190, China
| | - Xiaotao Hao
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong, 250100, P. R. China
| | - Zhixiang Wei
- School of Chemistry and Chemical Engineering, University of Chinses Academy of Sciences, Beijing, 100049, China
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Jianhui Hou
- State Key Laboratory of Polymer Physics and Chemistry, Beijing National Laboratory for Molecular Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences, Beijing, 100190, China
- School of Chemistry and Chemical Engineering, University of Chinses Academy of Sciences, Beijing, 100049, China
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3
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Yang C, Zhang S, Ren J, Bi P, Yuan X, Hou J. Fluorination strategy enables greatly improved performance for organic solar cells based on polythiophene derivatives. CHINESE CHEM LETT 2021. [DOI: 10.1016/j.cclet.2021.03.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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4
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Zhao T, Wang H, Pu M, Lai H, Chen H, Zhu Y, Zheng N, He F. Tuning the Molecular Weight of
Chlorine‐Substituted
Polymer Donors for Small Energy Loss
†. CHINESE J CHEM 2021. [DOI: 10.1002/cjoc.202000735] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Tingxing Zhao
- Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology Shenzhen Guangdong 518055 China
| | - Huan Wang
- Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology Shenzhen Guangdong 518055 China
| | - Mingrui Pu
- Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology Shenzhen Guangdong 518055 China
| | - Hanjian Lai
- Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology Shenzhen Guangdong 518055 China
| | - Hui Chen
- Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology Shenzhen Guangdong 518055 China
- Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology Shenzhen Guangdong 518055 China
| | - Yulin Zhu
- Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology Shenzhen Guangdong 518055 China
| | - Nan Zheng
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China, University of Technology Guangzhou, Guangdong 510640, China Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology Shenzhen Guangdong 518055 China
| | - Feng He
- Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology Shenzhen Guangdong 518055 China
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China, University of Technology Guangzhou, Guangdong 510640, China Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology Shenzhen Guangdong 518055 China
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5
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Wang T, Brédas JL. Organic Photovoltaics: Understanding the Preaggregation of Polymer Donors in Solution and Its Morphological Impact. J Am Chem Soc 2021; 143:1822-1835. [DOI: 10.1021/jacs.0c09542] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Tonghui Wang
- Department of Chemistry and Biochemistry, The University of Arizona, Tucson, Arizona 85721-0088, United States
| | - Jean-Luc Brédas
- Department of Chemistry and Biochemistry, The University of Arizona, Tucson, Arizona 85721-0088, United States
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6
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Ashokan A, Wang T, Coropceanu V, Brédas J. Bulk Heterojunction Solar Cells: Insight into Ternary Blends from a Characterization of the Intermolecular Packing and Electronic Properties in the Corresponding Binary Blends. ADVANCED THEORY AND SIMULATIONS 2020. [DOI: 10.1002/adts.202000049] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Ajith Ashokan
- School of Chemistry and Biochemistry & Center for Organic Photonics and Electronics (COPE)Georgia Institute of Technology Atlanta GA 30332‐0400 USA
| | - Tonghui Wang
- School of Chemistry and Biochemistry & Center for Organic Photonics and Electronics (COPE)Georgia Institute of Technology Atlanta GA 30332‐0400 USA
- Department of Chemistry and BiochemistryThe University of Arizona Tucson AZ 85721‐0088 USA
| | - Veaceslav Coropceanu
- School of Chemistry and Biochemistry & Center for Organic Photonics and Electronics (COPE)Georgia Institute of Technology Atlanta GA 30332‐0400 USA
- Department of Chemistry and BiochemistryThe University of Arizona Tucson AZ 85721‐0088 USA
| | - Jean‐Luc Brédas
- School of Chemistry and Biochemistry & Center for Organic Photonics and Electronics (COPE)Georgia Institute of Technology Atlanta GA 30332‐0400 USA
- Department of Chemistry and BiochemistryThe University of Arizona Tucson AZ 85721‐0088 USA
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7
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Zhang T, An C, Ma K, Xian K, Xue C, Zhang S, Xu B, Hou J. Increased conjugated backbone twisting to improve carbonylated-functionalized polymer photovoltaic performance. Org Chem Front 2020. [DOI: 10.1039/c9qo01251f] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two conjugated polymers containing different linkers were synthesized to study their photovoltaic performances.
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Affiliation(s)
- Tao Zhang
- Beijing National Laboratory for Molecular Sciences
- State Key Laboratory of Polymer Physics and Chemistry
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
| | - Cunbin An
- Beijing National Laboratory for Molecular Sciences
- State Key Laboratory of Polymer Physics and Chemistry
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
| | - Kangqiao Ma
- Beijing National Laboratory for Molecular Sciences
- State Key Laboratory of Polymer Physics and Chemistry
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
| | - Kaihu Xian
- Beijing National Laboratory for Molecular Sciences
- State Key Laboratory of Polymer Physics and Chemistry
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
| | - Changguo Xue
- School of Material Science and Engineering
- Anhui University of Science and Technology
- Huainan 232001
- China
| | - Shaoqing Zhang
- Beijing National Laboratory for Molecular Sciences
- State Key Laboratory of Polymer Physics and Chemistry
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
| | - Bowei Xu
- Beijing National Laboratory for Molecular Sciences
- State Key Laboratory of Polymer Physics and Chemistry
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
| | - Jianhui Hou
- Beijing National Laboratory for Molecular Sciences
- State Key Laboratory of Polymer Physics and Chemistry
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
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8
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Xue C, Tang Y, Liu S, Feng H, Li S, Xia D. Achieving efficient polymer solar cells based on benzodithiophene–thiazole-containing wide band gap polymer donors by changing the linkage patterns of two thiazoles. NEW J CHEM 2020. [DOI: 10.1039/d0nj02483j] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two conjugated polymers with different combinations of two thiazoles were synthesized to study their photovoltaic performances.
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Affiliation(s)
- Changguo Xue
- School of Material Science and Engineering
- Anhui University of Science and Technology
- Anhui
- China
| | - Yu Tang
- School of Material Science and Engineering
- Anhui University of Science and Technology
- Anhui
- China
| | - Shihui Liu
- MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage
- School of Chemistry and Chemical Engineering
- Harbin Institute of Technology
- Harbin 150001
- China
| | - He Feng
- School of Material Science and Engineering
- Anhui University of Science and Technology
- Anhui
- China
| | - Shiqin Li
- School of Material Science and Engineering
- Anhui University of Science and Technology
- Anhui
- China
| | - Debin Xia
- MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage
- School of Chemistry and Chemical Engineering
- Harbin Institute of Technology
- Harbin 150001
- China
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9
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Sun L, Xu X, Song S, Zhang Y, Miao C, Liu X, Xing G, Zhang S. Medium‐Bandgap Conjugated Polymer Donors for Organic Photovoltaics. Macromol Rapid Commun 2019; 40:e1900074. [DOI: 10.1002/marc.201900074] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 04/30/2019] [Indexed: 11/09/2022]
Affiliation(s)
- Liya Sun
- L. Sun, X. Xu, S. Song, Y. Zhang, Dr. C. Miao, Prof. X. Liu, Prof. S. ZhangKey Laboratory of Flexible Electronics & Institute of Advanced MaterialsJiangsu National Synergetic Innovation Center for Advanced MaterialsNanjing Tech University (Nanjing Tech) 30 South Puzhu Road Nanjing 211816 P. R. China
| | - Xiangfei Xu
- L. Sun, X. Xu, S. Song, Y. Zhang, Dr. C. Miao, Prof. X. Liu, Prof. S. ZhangKey Laboratory of Flexible Electronics & Institute of Advanced MaterialsJiangsu National Synergetic Innovation Center for Advanced MaterialsNanjing Tech University (Nanjing Tech) 30 South Puzhu Road Nanjing 211816 P. R. China
| | - Shan Song
- L. Sun, X. Xu, S. Song, Y. Zhang, Dr. C. Miao, Prof. X. Liu, Prof. S. ZhangKey Laboratory of Flexible Electronics & Institute of Advanced MaterialsJiangsu National Synergetic Innovation Center for Advanced MaterialsNanjing Tech University (Nanjing Tech) 30 South Puzhu Road Nanjing 211816 P. R. China
| | - Yangqian Zhang
- L. Sun, X. Xu, S. Song, Y. Zhang, Dr. C. Miao, Prof. X. Liu, Prof. S. ZhangKey Laboratory of Flexible Electronics & Institute of Advanced MaterialsJiangsu National Synergetic Innovation Center for Advanced MaterialsNanjing Tech University (Nanjing Tech) 30 South Puzhu Road Nanjing 211816 P. R. China
| | - Chunyang Miao
- L. Sun, X. Xu, S. Song, Y. Zhang, Dr. C. Miao, Prof. X. Liu, Prof. S. ZhangKey Laboratory of Flexible Electronics & Institute of Advanced MaterialsJiangsu National Synergetic Innovation Center for Advanced MaterialsNanjing Tech University (Nanjing Tech) 30 South Puzhu Road Nanjing 211816 P. R. China
| | - Xiang Liu
- L. Sun, X. Xu, S. Song, Y. Zhang, Dr. C. Miao, Prof. X. Liu, Prof. S. ZhangKey Laboratory of Flexible Electronics & Institute of Advanced MaterialsJiangsu National Synergetic Innovation Center for Advanced MaterialsNanjing Tech University (Nanjing Tech) 30 South Puzhu Road Nanjing 211816 P. R. China
| | - Guichuan Xing
- Institute of Applied Physics and Materials EngineeringUniversity of Macau Macao SAR 999078 China
| | - Shiming Zhang
- L. Sun, X. Xu, S. Song, Y. Zhang, Dr. C. Miao, Prof. X. Liu, Prof. S. ZhangKey Laboratory of Flexible Electronics & Institute of Advanced MaterialsJiangsu National Synergetic Innovation Center for Advanced MaterialsNanjing Tech University (Nanjing Tech) 30 South Puzhu Road Nanjing 211816 P. R. China
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10
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Zhang S, Qin Y, Zhu J, Hou J. Over 14% Efficiency in Polymer Solar Cells Enabled by a Chlorinated Polymer Donor. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1800868. [PMID: 29602243 DOI: 10.1002/adma.201800868] [Citation(s) in RCA: 352] [Impact Index Per Article: 58.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 02/27/2018] [Indexed: 05/25/2023]
Abstract
Fluorine-contained polymers, which have been widely used in highly efficient polymer solar cells (PSCs), are rather costly due to their complicated synthesis and low yields in the preparation of components. Here, the feasibility of replacing the critical fluorine substituents in high-performance photovoltaic polymer donors with chlorine is demonstrated, and two polymeric donors, PBDB-T-2F and PBDB-T-2Cl, are synthesized and compared in parallel. The synthesis of PBDB-T-2Cl is much simpler than that of PBDB-T-2F. The two polymers have very similar optoelectronic and morphological properties, except the chlorinated polymer possess lower molecular energy levels than the fluorinated one. As a result, the PBDB-T-2Cl-based PSCs exhibit higher open circuit voltage (Voc ) than the PBDB-T-2F-based devices, leading to an outstanding power conversion efficiency of over 14%. This work establishes a more economical design paradigm of replacing fluorine with chlorine for preparing highly efficient polymer donors.
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Affiliation(s)
- Shaoqing Zhang
- School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, 100083, P. R. China
- State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Yunpeng Qin
- School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, 100083, P. R. China
- State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Jie Zhu
- State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Jianhui Hou
- School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, 100083, P. R. China
- State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
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11
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Hu H, Chow PCY, Zhang G, Ma T, Liu J, Yang G, Yan H. Design of Donor Polymers with Strong Temperature-Dependent Aggregation Property for Efficient Organic Photovoltaics. Acc Chem Res 2017; 50:2519-2528. [PMID: 28915001 DOI: 10.1021/acs.accounts.7b00293] [Citation(s) in RCA: 183] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Bulk heterojunction (BHJ) organic solar cells (OSCs) have attracted intensive research attention over the past two decades owing to their unique advantages including mechanical flexibility, light weight, large area, and low-cost fabrications. To date, OSC devices have achieved power conversion efficiencies (PCEs) exceeding 12%. Much of the progress was enabled by the development of high-performance donor polymers with favorable morphological, electronic, and optical properties. A key problem in morphology control of OSCs is the trade-off between achieving small domain size and high polymer crystallinity, which is especially important for the realization of efficient thick-film devices with high fill factors. For example, the thickness of OSC blends containing state-of-the-art PTB7 family donor polymers are restricted to ∼100 nm due to their relatively low hole mobility and impure polymer domains. To further improve the device performance and promote commercialization of OSCs, there is a strong demand for the design of new donor polymers that can achieve an optimal blend morphology containing highly crystalline yet reasonably small domains. In this Account, we highlight recent progress on a new family of conjugated polymers with strong temperature-dependent aggregation (TDA) property. These polymers are mostly disaggregated and can be easily dissolved in solution at high temperatures, yet they can strongly aggregate when the solution is cooled to room temperature. This unique aggregation property allows us to control the disorder-order transition of the polymer during solution processing. By preheating the solution to high temperature (∼100 °C), the polymer chains are mostly disaggregated before spin coating; as the temperature of the solution drops during the spin coating process, the polymer can strongly aggregate and form crystalline domains yet that are not excessivelylarge. The overall blend morphology can be optimized by various processing conditions (e.g., temperature, spin-rates, concentration, etc.). This well-controlled and near-optimal BHJ morphology produced over a dozen cases of efficient OSCs with an active layer nearly 300 nm thick that can still achieve high FFs (70-77%) and efficiencies (10-11.7%). By studying the structure-property relationships of the donor polymers, we show that the second position branched alkyl chains and the fluorination on the polymer backbone are two key structural features that enable the strong TDA property. Our comparative studies also show that the TDA polymer family can be used to match with non-fullerene acceptors yielding OSCs with low voltage losses. The key difference between the empirical matching rules for fullerene and non-fullerene OSCs is that TDA polymers with slightly reduced crystallinity appear to match better with small molecular acceptors and yield higher OSC performances.
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Affiliation(s)
- Huawei Hu
- Department
of Chemistry, Energy Institute and Hong Kong Branch of Chinese National
Engineering Research Center for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Philip C. Y. Chow
- Department
of Chemistry, Energy Institute and Hong Kong Branch of Chinese National
Engineering Research Center for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Guangye Zhang
- Department
of Chemistry, Energy Institute and Hong Kong Branch of Chinese National
Engineering Research Center for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Tingxuan Ma
- Department
of Chemistry, Energy Institute and Hong Kong Branch of Chinese National
Engineering Research Center for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Jing Liu
- Department
of Chemistry, Energy Institute and Hong Kong Branch of Chinese National
Engineering Research Center for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Guofang Yang
- Department
of Chemistry, Energy Institute and Hong Kong Branch of Chinese National
Engineering Research Center for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - He Yan
- HKUST-Shenzhen Research Institute, No.
9 Yuexing first Road, Hi-tech Park, Nanshan, Shenzhen 518057, China
- Department
of Chemistry, Energy Institute and Hong Kong Branch of Chinese National
Engineering Research Center for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
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