Low-temperature-processed inorganic perovskite solar cells via solvent engineering with enhanced mass transport

All-inorganic perovskite materials (e.g. CsPbI2Br) have been demonstrated to be a promising candidate as the light absorber for solar cells because of their remarkable thermal stability. Herein, we develop a simple low-temperature solution process to carefully control the perovskite crystallization kinetics with enhanced mass transport during film deposition. It resulted in high-quality inorganic CsPbI2Br perovskite films to achieve a stabilized power conversion efficiency of 14.31% in the resultant planar heterojunction solar cell. Importantly, the as-prepared devices showed excellent thermal stability and light stability, wherein the devices maintained 83.58% of their original efficiency after 85 °C heat treatment for 500 h, and 90.33% of their initial efficiency with continuous light soaking for 500 h, respectively. Therefore, a universally feasible strategy is suggested to fabricate high-quality inorganic perovskite thin films for higher performance optoelectronic devices.