Interlayer twist angle-dependent electronic structure and optical properties of InSe/WTe2 van der Waals heterostructure

Abstract

In this paper, we have studied the interlayer twist angle-dependent electronic structure and optical properties of InSe/WTe2 van der Waals (vdW) heterostructure by density functional theory (DFT)-PBE calculations. The variation of electronic band structure and optical spectra of InSe/WTe2 vdW heterostructure at various interlayer twist angles i.e. 0°, 13.90°, 19.11°, and 30° have been studied in detail. It is observed that InSe/WTe2 heterostructure has an indirect bandgap of 0.22 eV with type-II band alignment at a 0° angle. The band alignment transitions remain type II under all twist angles. However, the bandgap type changes from indirect to direct bandgap for different twisted angles. Among all the twisted angles, 30° has the smallest no of atoms and lattice mismatch with the highest absorption in the visible region for various optoelectronic applications.