Type-II Band Alignment and Tunable Optical Absorption in MoSSe/InS van der Waals Heterostructure

Abstract

In this work, we study the electronic structure, the effective mass, and the optical properties of the MoSSe/InS van der Waals heterostructures (vdWHs) by first-principles calculations. The results indicate that the MoSSe/InS vdWH is an indirect band gap semiconductor and has type-Ⅱ band alignment in which the electrons and holes located at the InS and the MoSSe side, respectively. The band edge position, the band gap and the optical absorption of the MoSSe/InS vdWH can be tuned when biaxial strains are applied. In addition, compared with MoSSe and InS monolayers, the optical absorption of the MoSSe/InS vdWH is improved both in the visible and the ultraviolet regions. These findings indicate that the MoSSe/InS vdWHs have potential applications in optoelectronic devices.

Type-II 2D AgBr/SiH van der Waals heterostructures with tunable band edge positions and enhanced optical absorption coefficients for photocatalytic water splitting

“…In addition, applying strain on heterostructures has been a commonly used method for manipu-lating their optoelectronic characteristics. Prior studies have established that strain engineering can induce changes in the bandgap, [53][54][55] relocation of the band edge, 56 enhancement of the optical absorption coefficient, [57][58][59] and ad-justment of the band alignment of the hetero-structures. 60 To gain a complete understanding of the geometry, electronic and optical properties of AgBr/SiH vdW heterojunctions and how these properties are affected by strain, further research is needed as the current knowledge on this topic is limited.…”

“…In addition, applying strain on heterostructures has been a commonly used method for manipu-lating their optoelectronic characteristics. Prior studies have established that strain engineering can induce changes in the bandgap, 53–55 relocation of the band edge, 56 enhancement of the optical absorption coefficient, 57–59 and ad-justment of the band alignment of the hetero-structures. 60…”