Effect of passivation on the interface between perovskite and donoracceptor copolymer-based hole-transport layer in perovskite solar cells

Abstract

A donoracceptor copolymer, poly[(2,5-bis(2-hexyldecyloxy)phenylene)-alt-(5,6-difluoro-4,7-di(thiophen-2-yl)benzo[c][1,2,5]thiadiazole)] (PPDT2FBT), was used as a hole-transport layer (HTL) in mesoporous-type perovskite solar cells. To suppress carrier recombination, we introduced a passivation layer between the perovskiteHTL interface. As a result, the fill factor for the PPDT2FBT-based device was greatly improved to 0.81 and a power conversion efficiency of 18.4% was achieved.