Pang Shuting, Wang Zhiqiang, Yuan Xiyue, Pan Langheng, Deng Wanyuan, Tang Haoran, Wu Hongbin, Chen Shanshan, Duan Chunhui, Huang Fei, Cao Yong
Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China.
MOE Key Laboratory of Low-grade Energy Utilization Technologies and Systems, CQU-NUS Renewable Energy Materials & Devices Joint Laboratory, School of Energy & Power Engineering, Chongqing University, Chongqing, 400044, P. R. China.
Angew Chem Int Ed Engl. 2021 Apr 12;60(16):8813-8817. doi: 10.1002/anie.202016265. Epub 2021 Mar 8.
High-efficiency organic solar cells (OSCs) largely rely on polymer donors. Herein, we report a new building block BNT and a relevant polymer PBNT-BDD featuring B-N covalent bond for application in OSCs. The BNT unit is synthesized in only 3 steps, leading to the facile synthesis of PBNT-BDD. When blended with a nonfullerene acceptor Y6-BO, PBNT-BDD afforded a power conversion efficiency (PCE) of 16.1 % in an OSC, comparable to the benzo[1,2-b:4,5-b']dithiophene (BDT)-based counterpart. The nonradiative recombination energy loss of 0.19 eV was afforded by PBNT-BDD. PBNT-BDD also exhibited weak crystallinity and appropriate miscibility with Y6-BO, benefitting of morphological stability. The singlet-triplet gap (ΔE ) of PBNT-BDD is as low as 0.15 eV, which is much lower than those of common organic semiconductors (≥0.6 eV). As a result, the triplet state of PBNT-BDD is higher than the charge transfer (CT) state, which would suppress the recombination via triplet state effectively.
高效有机太阳能电池（OSC）在很大程度上依赖于聚合物供体。在此，我们报道了一种新型结构单元BNT以及一种具有B-N共价键的相关聚合物PBNT-BDD，用于有机太阳能电池。BNT单元仅通过3步合成，从而实现了PBNT-BDD的简便合成。当与非富勒烯受体Y6-BO共混时，PBNT-BDD在有机太阳能电池中实现了16.1%的功率转换效率（PCE），与基于苯并[1,2-b:4,5-b']二噻吩（BDT）的同类材料相当。PBNT-BDD的非辐射复合能量损失为0.19 eV。PBNT-BDD还表现出较弱的结晶度以及与Y6-BO的适当混溶性，有利于形态稳定性。PBNT-BDD的单重态-三重态能隙（ΔE）低至0.15 eV，远低于常见有机半导体的能隙（≥0.6 eV）。因此，PBNT-BDD的三重态高于电荷转移（CT）态，这将有效抑制通过三重态的复合。
