First-principles calculations of electronic structure and optical properties of Be-doped ZnO monolayer

The effect of Be doping on the electronic structure and optical properties of ZnO monolayer has been studied by first-principles density functional theory. The calculated negative formation energy of Be-doped ZnO monolayer suggests Be doping is feasible. Moreover, it is found that Be doping results in increasing of band gap of ZnO monolayer. Compared with pristine ZnO monolayer, imaginary parts of dielectric function of Be-doped ZnO monolayer move toward higher energy and the blue-shift of optical absorption edge is observed. Such modulation of the band gaps and optical properties provides Be-doped ZnO monolayer with promising application in ultraviolet photoelectronic device.