Stability of the CsPbI3 perovskite: from fundamentals to improvements

Abstract

Over the past few years, we have witnessed the occurrence and progress of the CsPbI₃ semiconductor material as a superstar in photovoltaic fields. By the virtue of its excellent photoelectric properties and solution processability, the all-inorganic CsPbI₃ solar cell has the possibility of production at the industrial level, taking into account the low production cost and high photoelectric conversion efficiency. The stability issues are considered as the main obstacles for its further development. In this review, we distinguish four different phase structures from the bond lengths, bond angles and symmetries, and put forward the techniques to identify the different phase structures based on various characterization methods. Subsequently, the stability of the CsPbI₃ film is assessed based its intrinsic characters, including thermodynamics, structure and material bonding type, and the external stimulation involving heat, light and moisture where the detailed chemical reaction procedures for the film degeneration are expressed. On this basis, some physical mechanisms to enhance the CsPbI₃ stability are proposed and related strategies are designed to delay the phase conversion processing by variance of its own structure (strain, surface energy and dimensionality) or intercepting the outsider interference. Finally, some noteworthy research studies are prospected.