Adjustable bandgap of a type-II AsP/SnS ₂ van der Waals heterostructure using strain: outstanding electronic, optical, and photocatalytic properties

In recent years, vertically stacked van der Waals heterostructures have attracted significant attention due to their highly tunable electronic properties and exceptional optical performance. Within the framework of density functional theory, we conducted a systematic investigation of the structural, electronic, and optical properties of a vertically stacked AsP/SnS₂ heterostructure. Our calculations reveal that the AsP/SnS₂ heterobilayer possesses an indirect bandgap of 1.24 eV, as determined by HSE06, and features a type-II band alignment that promotes the spatial separation of photogenerated charge carriers. Furthermore, the electronic structure of the AsP/SnS₂ heterostructure is found to be highly sensitive to external strain, offering avenues for band engineering. Notably, the heterostructure exhibits markedly enhanced optical absorption in the visible range compared to its constituent monolayers. These results provide the potential of the AsP/SnS₂ heterostructure as a promising candidate for high-performance visible-light-responsive photocatalysis and photoelectronic devices.