Optical and electronic properties of dichalcogenides WX2 (X=S, Se, and Te) monolayers under biaxial strain

Abstract The effects of biaxial strain on the electronic structures and optical properties of the two-dimensional WX 2 (X = S, Se, and Te) monolayers are investigated by first-principle calculations. The WX 2 monolayers are direct band gap semiconductors. Spin-orbit coupling has a significant effect on the electronic structures for WX 2 monolayers. The band gap, direct-indirect band gap transition, semiconductor to metal transition, dielectric constant, as well as absorption edge can be appropriately adjusted by the biaxial strain means. The superior ability of the WX 2 monolayers to modulate the electronic and optical properties provides an opportunity for the application of optoelectronic devices.