DFT study on the controllable electronic and optical properties of GaSb/InAs heterostructure

Abstract

By stacking layers with layers, heterojunction provides a new approach to improve the electronic and optical properties of two-dimensional materials. In this work, by means of density functional theory (DFT), the structural configurations, electronic and optical properties of two-dimensional GaSb/InAs vertical heterostructure (HTS) were systematically studied. The results show that the stability of ABII-stacking with the interlayer spacing of 2.5 A (h2.5-ABII model) is better than other heterogeneous models, and charge transfer occurs between GaSb and InAs slabs. The band structure of GaSb/InAs HTS is sensitive to the changes of stacking configuration, interlayer spacing, and external strain, as well as electric field. Under in-plane strains, the band gap of GaSb/InAs HTS undergoes direct–indirect transition, which has not been observed under the conditions of electric field. Moreover, the ultraviolet absorption capacity of GaSb/InAs HTS was significantly enhanced compared with that of free-standing monolayers. Overall, the controllable electronic structure and optical properties illustrate that GaSb/InAs HTS can be a good candidate for optoelectronic devices.