Tunable type-I band alignment and electronic structure of GaSe/MoSi2N4 van der Waals heterostructure

In this study, we have conducted an investigation on the structural characteristics and electronic properties of van der Waals heterostructures (vdWHs) composed of Gallium selenide (GaSe) and MoSi2N4. The analysis was carried out using first-principles methods. The findings indicate that the heterostructure exhibits stability at standard room temperature and possesses characteristics of an indirect bandgap semiconductor. Interestingly, we observed that the band edges of the heterostructure of monolayer GaSe and MoSi2N4 were able to form a type-I band alignment. Therefore, in the field of optoelectronic devices, GaSe/MoSi2N4 vdWHs can be widely used in light-emitting devices such as diodes. In addition, through the application of an external electric field and in-plane strain, the band edges of GaSe/MoSi2N4 vdWHs can be separated from the GaSe and MoSi2N4 layers, forming a transition from the type-I to type-II band alignment, which is very favorable for realizing effective electron-hole separation. Therefore, GaSe/MoSi2N4 vdWHs have great potential as an adjustable material in optoelectronic applications.