Liu Juncheng, Lu Hao, Liu Yahui, Zhang Jianqi, Li Cuihong, Xu Xinjun, Bo Zhishan
Key Laboratory of Energy Conversion and Storage Materials, College of Chemistry, Center for Advanced Quantum Studies, Department of Physics and Applied Optics, Beijing Area Major Laboratory, Beijing Normal University, Beijing 100875, P. R. China.
CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China.
ACS Appl Mater Interfaces. 2020 Mar 4;12(9):10746-10754. doi: 10.1021/acsami.9b22927. Epub 2020 Feb 24.
We designed and synthesized two non-fullerene acceptors (CDT-TFP and C8X-TFP), which comprise a central 4-cyclopenta[2,1-:3,4-']dithiophene (CDT) as the bridge and two thiophene-fused perylene diimide (TFP) units. The bulky side chains, such as the 4-hexylphenyl side chains, on the CDT bridge can effectively prevent the acceptor molecules from forming large aggregates, and the π-π stacking of the terminal planar TFP units can form effective electron transport pathways when blending with the donor polymers. These non-fullerene acceptors are used to fabricate organic solar cells (OSCs) by blending with the regioregular middle bandgap polymer reg-PThE. The as-cast devices based on reg-PThE:CDT-TFP show the best power conversion efficiency (PCE) of 8.36% with a of 1.10 V, of 12.43 mA cm, and an FF of 61.4%, whereas the analogue perylene diimide (PDI) dimers (CDT-PDI) that comprise two PDI units bridged with a CDT unit show only a 2.59% PCE with a of 0.92 V, of 6.82 mA cm, and an FF of 41.5%. Our results have demonstrated that the non-fullerene acceptors comprising planar PDI units can achieve excellent photovoltaic performance and provide meaningful guidelines for the design of PDI-based non-fullerene electron acceptors for efficient OSCs.
我们设计并合成了两种非富勒烯受体（CDT-TFP和C8X-TFP），它们包含一个中心的4-环戊并[2,1-:3,4-']二噻吩（CDT）作为桥连基团以及两个噻吩稠合的苝二酰亚胺（TFP）单元。CDT桥上的庞大侧链，如4-己基苯基侧链，能够有效防止受体分子形成大的聚集体，并且当与供体聚合物共混时，末端平面TFP单元的π-π堆积可以形成有效的电子传输途径。这些非富勒烯受体通过与区域规整的中带隙聚合物reg-PThE共混来制备有机太阳能电池（OSC）。基于reg-PThE:CDT-TFP的浇铸器件表现出最佳的功率转换效率（PCE）为8.36%，开路电压为1.10 V，短路电流密度为12.43 mA cm，填充因子为61.4%，而由一个CDT单元桥连两个PDI单元组成的类似苝二酰亚胺（PDI）二聚体（CDT-PDI）的PCE仅为2.59%，开路电压为0.92 V，短路电流密度为6.82 mA cm，填充因子为41.5%。我们的结果表明，包含平面PDI单元的非富勒烯受体可以实现优异的光伏性能，并为设计用于高效OSC的基于PDI的非富勒烯电子受体提供有意义的指导。
