Reducing defects: A review of preparation, doping and surface modification of nickel oxide

Abstract

Inverted perovskite solar cells (iPSCs) have attracted much attention due to their low hysteresis, low temperature fabrication procedure, and great potential for application in large area and flexible devices. As a star hole transport material, nickel oxide (NiO_X) have developed by leaps and bounds, and devices' efficiency has repeatedly amazed the world. In this paper, we focus on systematically elucidating the preparation process and defect mechanism of NiO_X, propose a series of general defect equations for different valence doping elements for the first time, and summarize the doping methods. As for surface modification, we take SAM material as a representative to explain how to make the NiO_X/SAM structure have better performance. More than that, we discuss the challenges faced in the commercialization of NiO_X-based devices and put forward feasible solutions, proposing prospects for the further development of NiO_X-based devices.