Modulating MAPbI3 perovskite solar cells by amide molecules: Crystallographic regulation and surface passivation

A controllable crystallization is of practical importance to produce high-quality perovskite thin films with reduced structural defects. Lewis bases as electron-pair donor chemicals can strongly coordinate to lead ions and have been extensively employed to manipulate the growth of perovskite crystals. In this work, we demonstrate a series of Lewis-base amides, for morphological regulation of methylammonium lead triiodide (MAPbI 3 ) thin films. The screened acetamide was demonstrated to decently improve the grain size, along with a spatial distribution at grain boundaries (GBs). The mesostructured solar cells of acetamide-modified absorbers yielded an optimized power conversion efficiency (PCE) of 20.04% with a mitigated open-circuit voltage ( V OC ) deficit of 0.39 V. This work provides a facile and cost-effective strategy toward controllable fabrication of high-performance MAPbI 3 solar cells.