A Theoretical Investigation of the Structural and Electronic Properties of P/SnBr₂ Heterojunctions

Abstract

In this paper, the structural and electronic properties of P/SnBr2 heterojunctions were investigated using the first-principles calculation method based on the density functional theory (DFT). The band alignment of the P/SnBr2 heterojunction was type I. The bandgap value was 0.71 eV in the DFT calculation. Furthermore, the bandgap of the heterojunction could be efficiently tuned by controlling an electric field and biaxial strain. The bandgap changed linearly with the electric field in a certain range; when the electric field was greater than 0.8 V/Å, the heterojunction was metallic. The bandgap could also be tuned when a biaxial strain was applied. Under tensile or compressive stress, significant effects such as the band alignment shift from type I to type III, and the transition from indirect to direct bandgap occurred. In conclusion, these research findings provide theoretical guidance for designing new heterojunctions based on SnBr2.

Keywords

• two-dimensional heterostructure
• electric field
• biaxial strain
• bandgap
• density functional theory