Study On The Preparation,Microstructure,Surface Morphology,and Optical Properties Of Doped ZnO Thin Films

Undoped and Cu-doped ZnO(ZnO:Cu)thin films were prepared using magnetron co-sputtering.Effects of substrate temperature Ts on their structural,electrical and optical properties were comparatively investigated using X-ray diffraction,atom force microscopy,and ultraviolet visible spectrophotometer.ZnO: Cu thin films with different doping content were prepared and studied in order to investigate the effects of Cu-doping content.The results show that all the films exhibit a single phase(002)oriented hexagonal wurtzite structure,Higher Ts enhances the crystallinity and reduces the compressive stress of the films.Cu-doping and increasing Ts lead to rougher surface and larger granules,The resistivity of both the ZnO and ZnO:Cu films increases with Ts.Interestingly,optical band gap Eg of ZnO:Cu films increases significantly with Ts,while Eg of undoped film is not obviously influenced by Ts.Cu-doping content is an important factor affecting the physical properties of ZnO:Cu thin films.In our experiments,Cu-doping composition slightly decreases with Ts increasing.Cu-doping reduces the resistivity,leads to the red-shift of absorption edge,and narrows Eg of ZnO thin films.For copper and nitrogen doped thin films,found that nitrogen doping can also reduce the band width of film.The above results of explanation attribute to on the carrier concentration and the influence of band structure.In this paper,the research shows that copper and nitrogen doped ZnO thin film is a kind of effective way.that regulates the physical properties of ZnO thin films.