Tunable electronic and optical properties of MoTe₂/InSe heterostructure via external electric field and strain engineering

Abstract

Based on first-principles calculation under density functional theory (DFT), the geometry, electronic and optical properties of the MoTe2/InSe heterojunction have been investigated. The results reveal that the MoTe2/InSe heterojunction has a typical Type-Ⅱ band alignment and exhibits an indirect bandgap of 0.99 eV. In addition, the Z-scheme electron transport mechanism is capable of efficiently separating photogenerated carriers. The bandgap of the heterostructure changes regularly under applied electric field and exhibits a significant Giant Stark effect (GSE). Under an applied electric field of 0.5 V/Å, the band alignment of the heterojunction shifts from Type-Ⅱ to Type-I. The application of strain produced comparable changes in the heterojunction. More importantly, the transition from semiconductor to metal is completed in the heterostructure under the applied electric field and strain. Furthermore, the MoTe2/InSe heterojunction retains the optical properties of two monolayers and produces greater light absorption on this basis, especially for UV light. The above results offer a theoretical basis for the application of MoTe2/InSe heterostructure in the next generation of photodetectors.

Tunable electronic and optical properties of WSe2/Si2H heterojunction via electric field

“…As a typical member of TMDs, WSe 2 has received special attentions due to its wide light absorption range and strong light absorption efficiency, and dynamically tunable charge carriers by external electric fields [17]. Based on such properties, various field-effect diodes have been reported where the electronic and optoelectronic properties can be modulated by the gate voltage [18][19][20].…”

First-principles study of the electronic and optical properties of two-dimensional PtS2/GaS van der Waals heterostructure

“…VdW heterostructures are formed by stacking different 2D materials in the vertical direction via vdW forces and require less lattice matching. VdW heterostructures can maintain the advantages of individual monolayer materials while showing structural and electronic diversities with flat interfaces and no hanging bonds [30][31][32][33]. Compared with traditional materials, vdW heterostructures have broad application potential in the fields of optoelectronic devices, infrared detection, and energy conversion and storage [34][35][36][37].…”