Interface-controlled Band Alignments in Janus Ga2STe/MoSi2N4 Vdwhs

The band alignment based on two-dimensional (2D) van der Waals heterostructures (vdWHs) plays an important role in electronic and optoelectronic characteristics. Inspired by the advantages of MoSi2N4 and Janus Ga2STe, we construct the S and Te interface-based Ga2TeS (Ga2STe)/MoSi2N4 vdWHs to explore the interface-controlled band alignment transition, considering the effects of electric field, interlayer distance and biaxial strain. The results show that the Ga2TeS/MoSi2N4 and Ga2STe/MoSi2N4 vdWHs exhibit the direct band structures with the staggered and straddling band alignment, respectively. Enhancing interlayer coupling can switch type-I and type-II band alignment for the S- and Te-sides vdWHs. In particular, the external electric field and biaxial strain can induce the band alignment transfer between type-I, type-II, and type-III in the two vdWHs. These results indicate the interface-controlled Janus Ga2TeS/MoSi2N4 vdWHs can provide more possible electronic and optoelectronic applications.