Investigation On The Properties Of Re-Doped ZnSe Thin Film Prepared By Vacuum Evaporation

Dy-doped and Nd-doped ZnSe thin films were prepared by vacuum evaporation on glass substrates, and were annealed at T=350℃, t=20min in nitrogen. The characteristics of the samples were tested by X-ray diffraction instrument,X-ray photoelectron spectrograph,ultraviolet-visible spectrophotometer and AFM According to the result of the test, we analysed and optimized the preparation process of the ZnSe thin film. At the same time, the influences of the Dy-doping and Nd-doping on the ZnSe thin film was studied.The experimental results showed that the better ZnSe thin films were prepared when the mixture ratio of high pure Zn and Se was Zn:Se=0.9:1. When the samples were annealed at T>250℃, t=20min, we can obtain pure polycrystalline ZnSe thin films, and there was not Zn phase or Se phase in the ZnSe thin films.The influence of rare-earth doping on the crystallography and optical characteristics of the ZnSe thin films was evident. We found that Dy-doping did not change the sample's crystal structure and the type of conduction, and restrained the combination of ZnSe and the surface topography, minished the grain size and Internal stress, increased the lattice constant and the crystal cell volume, decreased the optical band gap slightly and improved the optical transmission. And Nd-doping had similar infections to ZnSe thin films. Nd-doping did not change the sample's crystal structure and the type of conduction, but restained the surface topography and the combination of ZnSe thin films, and led to the Internal stress decreased, increased the lattice constant and the crystal cell volume, improved the optical transmission clearly, but decreased the optical band gap.