Tunable Optoelectronic Properties of A Type-II Violet Phosphorus/MoS₂ Heterojunction: First-Principles Calculation

Photodetectors based on heterostructures have garnered significant research interest due to their superior self-powering and responsiveness capabilities. In this work, the optoelectronic properties of a violet phosphorus (VP)/MoS2 heterojunction are investigated through first-principles calculations. The results reveal that the VP/MoS2 heterojunction possesses an indirect bandgap with 1.086eV and a type-II band alignment. The interface potential drop <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\boldsymbol{(E_{p})}$</tex> of the VP/MoS<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> heterojunction is 5.49 eV by studying the interfacial interaction, suggesting the formation of a large in-built electric field and an excellent self-powering capability. The absorption coefficient of VP/MoS2 heterojunction are significantly higher in the UV and visible regions. Under biaxial strain, the VP/MoS2 heterostructure can undergo transformations from a semiconductor to a metal, from an indirect to a direct bandgap, and from a type-II to a type-I energy band structure. Moreover, the light trapping ability in the near-infrared region is significantly enhanced. These findings underscore the broader potential application of VP/MoS2 heterostructures in high-performance optoelectronic devices.