New alternating D–A1–D–A2 copolymer containing two electron‐deficient moieties based on benzothiadiazole and 9‐(2‐Octyldodecyl)‐8H‐pyrrolo[3,4‐b]bisthieno[2,3‐f:3',2'‐h]quinoxaline‐8,10(9H)‐dione for efficient polymer solar cells |
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| Authors: | M L Keshtov S A Kuklin D Y Godovsky A R Khokhlov R Kurchania F C Chen Emmanuel N Koukaras G D Sharma |
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| Institution: | 1. A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Moscow, Russia;2. Faculty of Physics, Lomonosov Moscow State University, Moscow, Russian Federation;3. Department of Physics, Maulana Azad National Institute of Technology (MANIT), Bhopal, Madhya Pradesh, India;4. Department of Photonics, National Chiao Tung University, 1001 University Road, Hsinchu, Taiwan;5. Institute of Chemical Engineering Sciences, Foundation for Research & Technology, Hellas, Patras, Greece;6. Molecular Engineering Laboratory, Department of Physics, University of Patras, Patras, GR, Greece;7. R&D Center for Engineering and Science, JEC Group of Colleges, Jaipur Engineering College, Jaipur, Rajasthan, India |
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| Abstract: | A novel D–A1–D–A2 copolymer denoted as P1 containing two electron withdrawing units based on benzothiadiazole (BT) and 9‐(2‐octyldodecyl)?8H‐pyrrolo3,4‐b] bisthieno2,3‐f:3′,2′‐h]quinoxaline‐8,10(9H)–dione (PTQD) units was synthesized and characterized. The resulting copolymer exhibits a broad‐absorption spectrum, relatively deep lying HOMO energy level (?5.44 eV) and narrow optical bandgap (1.50 eV). Bulk heterojunction (BHJ) polymer solar cells (PSCs) based on P1 as donor and PC71BM as acceptor with optimized donor to acceptor weight ratio of 1:2 and processed with DIO/CB solvent showed good photovoltaic performance with power conversion efficiency of 6.21% which is higher than that of the device processed without solvent additive (4.40%). The absorption and morphology investigations of the active layers indicated that structural and morphological changes were induced by the solvent additive. This higher power conversion efficiency could be mainly attributed to the absorption enhancement and improved charge transported in the active layer induced by the better nanoscale morphology of the active layer. This study demonstrated that a copolymer with two different acceptor moieties in the backbone may be promising candidate as donor copolymer for solution processed BHJ PSCs. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 155–168 |
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| Keywords: | bulk heterojunction charge transport copolymers based on strong and weak acceptors polymer solar cells solvent additives |
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