Mechanisms and applications of laser action on lead halide perovskites

Abstract

In recent years, lead-halide perovskites, one of the most competitive material types in the field of semiconductors, has attracted widespread attention because of its easy preparation, low cost, and high performance. Lead-halide perovskites are a type of material with an ABX3 structure, in which A is an organic or inorganic monovalent cation, B is a divalent cation, and X is a halogen ion. Among them, the B-site ion and X-site ion form an octahedron, with the B-site ion occupying the center and the X-site ion located at the apex of the octahedron. This type of octahedron can undergo lattice changes such as rotation or tilt through the replacement of different halogen anions, which affects the material band gap. The octahedron is located in the center of a cube, which is composed of A-site ions. These structures constitute the basic unit of the perovskite. Compared with the widely used II-VI or III-V semiconductor nanocrystalline materials, perovskite nanocrystals have great application potential owing to their superior optoelectronic performance. However, their stability problem restricts further development, making them unable to compete in commercial applications. Studies on the stability of perovskite materials began in 2009. It was discovered through experiments that perovskite materials would undergo irreversible degradation under the action of liquid polar solvents, which confirmed that humidity and air are important factors in perovskite degradation. With further research, the problem of illumination has also come to the surface. It was found through experiment that, when oxygen and humidity were excluded, the light condition could also have a certain negative impact on perovskite materials, and subsequently perform a certain repair effect. Research in this area can lay a foundation for the preparation of high-stability perovskite materials and devices, adjust the structure and performance of perovskite by lighting technology (especially laser irradiation), and expand its comprehensive application in the field of optoelectronics. This article focuses on the changes in perovskites under laser irradiation and the related applications. First, it reviews the unstable changes and micro-mechanisms that laser-irradiation induces in lead-halide perovskites, including accelerated degradation, repair of defects, segregation, phase transitions, and changes in the grain size. Second, based on these mechanisms, it explains how researchers have recently used laser-irradiation technology to control the performance of perovskite films and devices. In addition, it also introduces the application of the laser direct writing process in the fields of perovskite patterning and photoelectric detection. Finally, this paper summarizes the changes induced by the laser-irradiation illumination and applications of laser-irradiated lead-halide perovskites.