Microstructure, Surface Morphology And Optical Properties Of Cu-doped ZnO Thin Films Prepared By Magnetron Co-sputtering

Nitrogen doped ZnO films were prepared by magnetron sputtering. We studied the influence of nitrog en partial pressure and oxygen partial pressure on the microstructure, morphology and optical properties of the thin films by the method of scanning electronic microscopy, X-ray diffraction, ultra-violet-visible absorption. Undoped ZnO thin films were also fabricated as control.Single phase(002)-oriented hexagonal wurtzite structure was obtained in ZnO:N films. The results show that N-doping can change the lattice constant and stress, and different doping defect influences the behavior of stress. A red-shift of absorption edge and band gap na rrowing phenomena was observed with N-doping, and Eg value decreases with N-content increasing. Increasing oxygen partial pressure reduces the density of nitrogen substitute No and oxygen vacancies Vo, which results in the structural and optical property modification of ZnO:N films. Ionic No is an important effective factor narrowing Eg. Lower pressure can improve the No formation and Eg reduction.