Two-dimensional type-II XSi2P4/MoTe2 (X = Mo, W) van der Waals heterostructures with tunable electronic and optical properties

Recently, the synthesized two-dimensional (2D) MoSi2P4 monolayer with excellent environmental stability and suitable bandgap has attracted considerable attention. Here, we systematically investigated the structural, electronic and optical properties of the XSi2P4/MoTe2 (X = Mo, W) van der Waals heterostructures (vdWHs) based on first-principles calculations. Our results demonstrate that the type-II MoSi2P4/MoTe2 (WSi2P4/MoTe2) possesses a direct bandgap of 0.258 eV (0.363 eV) at the PBE level. The biaxial strain and external electric field can effectively modulate the band alignment of the heterostructures from type-II to type-I and achieve a semiconductor-metal transition. Additionally, WSi2P4/MoTe2 exhibits superior optical adsorption compared to their individual components in the visible-light region. The adsorption coefficient of MoSi2P4/MoTe2 reached up to 10(6) cm(-1) in the ultraviolet region. The work provides a valuable theoretical guidance for the design of optoelectronic devices based on XSi2P4/MoTe2 vdWHs and indicates that the XSi2P4/MoTe2 vdWHs show promising application in the nanoelectronic and optoelectronic fields.

Automated summary

This study systematically investigated the structural, electronic, and optical properties of XSi2P4/MoTe2 van der Waals heterostructures based on first-principles calculations. The results demonstrate that XSi2P4/MoTe2 possess suitable bandgap and semiconductor-metal transition characteristics, with excellent optical absorption performance in the visible and ultraviolet regions.