Strain-enhanced electron mobility and mobility anisotropy in a two-dimensional vanadium diselenide monolayer

This paper investigates the impacts of compressive and tensile uniaxial strains on the lattice and electronic properties of the two-dimensional (2H-phase) vanadium diselenide ( VS e 2 ) monolayer, which hitherto has not yet been synthesized, by using first-principles density functional theory and deformation potential theory. Under equilibrium, it is found that the mobility in the “zigzag” direction ( μ zig ≈ 307 c m 2 / V s ) is about 3.20 times larger than the mobility in the “armchair” direction ( μ arm ≈ 96 c m 2 / V s ). It is revealed that by applying 1%, 2%, and 3% compressive uniaxial strains along the “zigzag” direction, μ zig can be enhanced by 2.20, 5.25, and 10.55 times, respectively. The strain dependence of the bandgap, effective mass, elastic modulus, and deformation potential constant are analyzed quantitatively, in order to better understand the underlying mechanism. The strain-enhanced electron mobility and mobility anisotropy properties of the emerging two-dimensional VS e 2 monolayer might be useful to implement novel devices and sensors.