Effect of PbI2 passivation to grain boundary of perovskite film with cation and anion co-mixing on performance of photovoltaic devices

Abstract

Perovskite components have tremendous influence on the film quality and device performance. There are obvious impurity defects, holes, etc. in the films of conventional perovskite solar cells (PSCs). In this work, the perovskite component was tuned to [HC(NH2)2]0.3(CH3NH3)0.7PbI2.4Cl0.3Br0.3 (FA0.3MA0.7PbI2.4Cl0.3Br0.3) via cation and anion co-mixing, it was observed that the residual PbI2 at perovskite film had a good passivation effect on the grain boundaries and further ameliorated the quality of the film. The photoelectric conversion efficiency (PCE) of low-cost carbon electrode-based photovoltaic devices we prepared increased from 8.58% to 12.40%. Our work will also be more beneficial to the commercialization of PSCs and the preparation of other optoelectronic devices.