A first-principles study of the structural, electronic, and optical properties of NaF and CsPbX3 heterojunctions under strain

Abstract

This paper investigates the interface interaction of NaF with perovskite and its effects on the structural, electronic, and optical properties under strain. CsPbX₃ perovskite has gained significant attention for its outstanding optoelectronic performance in light-emitting devices, while NaF, as a passivation layer, is considered a promising candidate material because of its insulating properties. The calculation results show that a NaF/CsPbX₃ heterojunction forms a stable structure due to the attraction between Na⁺ and X⁻. Electronic structure analysis reveals the formation of a type-I band alignment that favors charge separation and carrier dynamics at the interface. The partial density of states indicates that [PbX₃]⁻ and Na⁺ are the main contributors. The optical property calculation results of the heterojunction indicate that the interface interaction with NaF causes a red shift and enhances the optical properties of the perovskite material. Research indicates that the interface interaction of NaF can provide theoretical support for the study of high-performance NaF/CsPbX₃ heterojunction sensors.