Theoretical design of Janus-In2STe/InSe lateral heterostructure: A DFT investigation

Abstract

Recent great advances in the study of heterostructure engineering have motivated us to study the Janus-In 2 STe/InSe lateral heterostructure (LHS). By using the density functional theory (DFT) calculation, the stability, electronic, and optical properties of Janus-In 2 STe/InSe LHS are systematically investigated. The calculated results indicate that the Janus-In 2 STe/InSe LHS is theoretical stable because of small lattice mismatch and low heats of formation . It is also found that the Janus-In 2 STe/InSe LHS always presents a direct band gap semiconducting character with type-I band alignment regardless of the heterostructure width. The band gaps reduce slowly with increasing component units of the heterostructure. Particularly, the significant charge transfer from Janus In 2 STe to InSe layer can be found, resulting in a reasonable and moderate work function of the LHS, whose value is between Janus-In 2 STe and InSe. In addition, the Janus-In 2 STe/InSe LHS also exhibit a high optical absorption coefficient (∼8 × 10 5 cm −1 ) from visible light zone to ultraviolet light zone. The present calculated results suggest that the Janus-In 2 STe/InSe LHS can be a good candidate material for optoelectronic devices . • The novel Janus-In 2 STe/InSe LHS connected by covalent bonds are designed. • The Janus-In 2 STe/InSe LHS is always a direct band gap semiconductor with type-I band alignment regardless of the heterostructure width. • The Janus-In 2 STe/InSe LHS exhibits a high optical absorption coefficient (∼8 × 10 5 cm −1 ) from visible light zone to ultraviolet light zone.