Strain forces tuned the electronic and optical properties in GaTe/MoS2 van der Waals heterostructures

Abstract

Two-dimensional (2D) van der Waals heterostructures (vdWHs) have attracted widespread attention in fundamental materials science and device physics. In this work, we report a novel GaTe/MoS₂ vdWH and theoretically investigate the electronic and optical properties based on first-principles calculations. GaTe/MoS₂ vdWH possesses an indirect band gap with type-II band alignment. Meanwhile, the interfacial charge transfer from MoS₂ to GaTe can effectively separate electrons and holes. Also, this vdWH shows improved visible-ultraviolet optical absorption properties compared with those of the isolated GaTe or MoS₂ monolayers. More remarkably, the biaxial strain can not only modulate the band gap but also enhance the optical performance in GaTe/MoS₂ vdWH. In particular, the tensile strain is more effective for improving the optical absorption in the visible light region. These findings indicate that GaTe/MoS₂ vdWH is a promising candidate for nanoelectronics and optoelectronic devices.