High-Efficiency Organic Solar Cells Enabled by Chalcogen Containing Branched Chain Engineering: Balancing Short-Circuit Current and Open-Circuit Voltage,Enhancing Fill Factor |
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| Authors: | Jiefeng Hai Yuanxia Song Ling Li Xin Liu Xiaoyu Shi Zhuoyue Huang Guangming Qian Zhenhuan Lu Jiangsheng Yu Huawei Hu Shangshang Chen |
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| Affiliation: | 1. Guangxi Colleges and Universities Key Laboratory of surface and interface electrochemistry, Guangxi Key Laboratory of Electrochemical and Magneto-chemical Functional Materials, School of Chemistry and Bioengineering, Guilin University of Technology, Guilin, 541004 P. R. China;2. School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing, 210094 P. R. China;3. State Key Laboratory of Coordination Chemistry, MOE Key Laboratory of High Performance Polymer Materials & Technology, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023 P. R. China;4. State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai, 201620 P. R. China |
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| Abstract: | The elaborate balance between the open-circuit voltage (VOC) and the short-circuit current density (JSC) is critical to ensure efficient organic solar cells (OSCs). Herein, the chalcogen containing branched chain engineering is employed to address this dilemma. Three novel nonfullerene acceptors (NFAs), named BTP-2O , BTP-O-S , and BTP-2S , featuring different peripheral chalcogen containing branched chains are synthesized. Compared with symmetric BTP-2O and BTP-2S grafting two alkoxy or alkylthio branched chains, the asymmetric BTP-O-S grafting one alkoxy and one alkylthio branched chains shows mediate absorption range, applicable miscibility, and favorable crystallinity. Benefiting from the enhanced π–π stacking and charge transport, an optimal power conversion efficiency (PCE) of 17.3% is obtained for the PM6: BTP-O-S -based devices, with a good balance between VOC (0.912 V) and JSC (24.5 mA cm?2), and a high fill factor (FF) of 0.775, which is much higher than those of BTP-2O (16.1%) and BTP-2S -based (16.4%) devices. Such a result represents one of the highest efficiencies among the binary OSCs with VOC surpassing 0.9 V. Moreover, the BTP-O-S -based devices fabricated by using green solvent yield a satisfactory PCE of 17.1%. This work highlights the synergistic effect of alkoxy and alkylthio branched chains for high-performance OSCs by alleviating voltage loss and enhancing FF. |
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| Keywords: | chalcogen containing branched chains charge transports fill factor nonfullerene acceptors organic solar cells |
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