Targeted Therapy for Interfacial Engineering Toward Stable and Efficient Perovskite Solar Cells
Shuhui Wang1, Haiyang Chen1, Jiandong Zhang2, Guiying Xu1, Weijie Chen1, Rongming Xue1, Moyao Zhang1, Yaowen Li*,1（李耀文）, and Yongfang Li*,1,3（李永舫）
1Laboratory of Advanced Optoelectronic Materials College of Chemistry Chemical Engineering and Materials Science Soochow University Suzhou 215123, China
2College of Chemistry Chemical Engineering and Materials Science Soochow University Suzhou 215123, China
3Beijing National Laboratory for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing 100190, China
Adv. Mater. 2019, 31, 1903691
The poor long‐term stability of organic–inorganic hybrid halide perovskite solar cells (pero‐SCs) remains a big challenge for their commercialization. Although strategies such as encapsulation, doping, and passivation have been reported, there remains a lack of understanding of the water resistance and thermal stability of pero‐SCs. A fullerene derivative, [6,6]‐phenyl‐C61‐butyric acid‐N,N‐dimethyl‐3‐(2‐thienyl)propanam ester (PCBB‐S‐N) containing a functional sulfur atom and C60, is synthesized and employed as electron transporting layer (ETL)/intermediary layer to targetedly heal the multitype defects in pero‐SCs or assist the growth of ETL, such as [6,6]‐phenyl‐C61‐butyric acid methyl ester (PCBM), in planar p‐i‐n pero‐SCs. The repaired pero‐SCs can not only dramatically improve their power conversion efficiencies, but also address stability issues under moisture and high temperature. The corresponding mechanism of PCBB‐S‐N with targeted therapy effect in a device is systematically investigated by both experiments and theoretical calculation. This work demonstrates that the proposed fullerene derivative with finely tuned chemical structure can be a promising ETL candidate or intermediary to approach stable and efficient planar p‐i‐n pero‐SCs.