Investigation on optoelectronic performances of Al, N codoped ZnO: First-principles method

To analyze the electronic structure and optical properties of (Al, N) codoped ZnO, We investigated the parameters such as band structure, density of states (DOS), charge population, dielectric constant, absorption and reflection spectra of pure ZnO, N-doped, Al–N codoped and Al–2N codoped ZnO by using first-principles based on density functional theory (DFT). The results demonstrated that the cases of N doping and Al–2N codoping performance p-type, and Al–2N codoping can obtain a high optical quality and more stable p-type ZnO. Compared with other conditions, the real and imaginary part of dielectric function of Al–2N codoped ZnO have a significant increase and move to the lower energy direction; in the ultraviolet and visible region, the absorption spectrum increases greatly, and the red shift can be observed; in the infrared region, the reflectivity spectrum of Al–2N codoped ZnO is about 4 times that of pure ZnO or Al–N codoped ZnO. The results may supply a certain theoretical reference for study of ZnO-based transparent conductive thin films.