Strain and electric field tuning of semi-metallic character WCrCO <sub>2</sub> MXenes with dual narrow band gap
A. Bafekry, Berna Akgenç, Mitra Ghergherehchi, F. M. Peeters
Abstract
Abstract Motivated by the recent successful synthesis of double-M carbides, we investigate structural and electronic properties of WCrC and WCrCO 2 monolayers and the effects of biaxial and out-of-plane strain and electric field using density functional theory. WCrC and WCrCO 2 monolayers are found to be dynamically stable. WCrC is metallic and WCrCO 2 display semi-metallic character with narrow band gap, which can be controlled by strain engineering and electric field. WCrCO 2 monolayer exhibits a dual band gap which is preserved in the presence of an electric field. The band gap of WCrCO 2 monolayer increases under uniaxial strain while it becomes metallic under tensile strain, resulting in an exotic 2D double semi-metallic behavior. Our results demonstrate that WCrCO 2 is a new platform for the study of novel physical properties in two-dimensional Dirac materials and which may provide new opportunities to realize high-speed low-dissipation devices.