LAUSR

Abstract The effects of biaxial strain on the electronic structures and optical properties of the two-dimensional WX2 (X = S, Se, and Te) monolayers are investigated by first-principle calculations. The WX2 monolayers are direct band gap semiconductors. Spin-orbit coupling has a significant effect on the electronic structures for WX2 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 WX2 monolayers to modulate the electronic and optical properties provides an opportunity for the application of optoelectronic devices.