Electronic Performance and Schottky Contact of 2D GeH/InSe and GeH/In2Se3 Heterostructures: Strain Engineering and Electric Field Tunability

Recent exciting developments in synthesis and properties study of the germanane (GeH) mono-layer have inspired us to investigate the structural and electronic properties of the van der Waals heterostructures (HTS) of GeH/InSe and GeH/In2Se3 through a first-principles methodology. In this study, structural and electronic properties of the HTS are examined thoroughly. GeH/InSe and GeH/In2Se3 are determined as n-type Schottky with a Schottky barrier height (SBH) of 0.40 eV and n-type ohmic, respectively. GeH/InSe turns out as a semiconductor with a direct bandgap of 0.62 eV, while GeH/In2Se3 is seen to be a metal. The results show that changing of the bandgap and SBH in very small values. For GeH/In2Se3 the effects are even less substantial, as the metallic or n-type nature of the material does not change. The biaxial strain and electric field have more tangible effects on the characteristics of the HTS. A mixture of compressive and tensile strain is seen to have the capability of changing GeH/InSe into a metal and at the same time transform it to an n-type/p-type ohmic or p-type Schottky contact. The results given here can guide future research in the field of HTS and especially GeH-based devices.