A type-II MoS2/GaN van der Waals heterostructure with tunable electronic and optical properties based on first principles

This paper presents a MoS2/GaN van der Waals heterostructure (vdWH), the geometric, electronic and optical properties of vdWH are methodically studied using the first-principles calculations. Ab initio molecular dynamics (AIMD), phonon spectrum and elastic constants indicated that A1 configuration is the most stable, with an interlayer distance of 3.01 & Aring;. Through the analysis of the electronic properties of the MoS2/GaN vdWH, it is suggested that the heterostructure exhibits a type-II band alignment, characterized by a direct band gap of 1.33 eV. Furthermore, the MoS2/GaN heterostructure exhibits excellent carrier mobility and anisotropy, which are favorable for photovoltaic and photocatalytic applications. In addition, biaxial strain can effectively tune the band gap and the type-II heterostructure alignment. The heterostructure exhibits both redshift and blueshift in the vertical direction, extending its light absorption range. The light absorption coefficients in the parallel direction are also improved. These results suggest that the MoS2/GaN vdWH offers a broad scope of potential applications in future photovoltaic and optoelectronic nanodevices.