Enhancing spintronic and optoelectronic properties of 2D and quasi-2D CsPbBr3 perovskite via lithium doping

Abstract

Two-dimensional (2D) perovskites are emerging as promising candidates for applications in photovoltaics and scintillation due to their stability and exceptional optoelectronic properties. In this study, the impact of lithium (Li) doping on the electronic, optical, and spintronic properties of quasi-2D perovskite structures, including CsPbBr3 and (PEA)2Pb2CsBr7, was systematically investigated using density functional theory. Our results reveal that Li doping introduces significant changes in spin–orbit coupling-induced band splitting, charge distribution, and spin texture due to asymmetry. The magnitude of these alterations depends on the type of 2D structure and surface termination. Spin texture analysis revealed parallel alignment of spin vectors in the valence band maximum and conduction band minimum for all configurations, enabling spin-allowed transitions. This characteristic, along with the transition from direct to indirect band gaps, reduces charge carrier recombination rates and enhances the material's potential for scintillation applications. These findings underscore the critical role of Li doping in tuning the optoelectronic and spintronic properties of 2D and quasi-2D CsPbBr3 perovskites, paving the way for their use in radiation detection and energy conversion technologies.