The Preparation And Investigation Of Re-Doped CdS Thin Film

Pure,Dy-doped and La-doped CdS thin films were prepared by chemical bath deposition on glass substrates, and were annealed at T=300℃,350℃, t=40min in nitrogen. The characteristics of the samples were tested by X-ray diffraction instrument,the Scanning Electron Microscopy,ultraviolet-visible spectrophotometer and X-ray photoelectron spectrograph. According to the result of the test, the character of CdS thin film was studied when the condition of reactant concentration,deposition temperature and deposition time have been changed.The experimental results showed that the better CdS thin film were prepared when the deposition temperature was set in 70℃and the deposition time was set in 30min. In this case the CdS thin film was cubic structure and has preferred orientation of crystal plane [111]. In addition to this, there was more Cd phase in the CdS thin film.The influence of rare-earth doping on the exterior status,crystallography and optical characteristics of the CdS thin films was evident. The doping of Dy has not change the sample's crystal structure and preferred orientation, the thin film has cubic structure and preferred orientation of crystal plane [111]. After the doping of Dy, the exrernal status of the thin film get better, the grain size get more density and the thin film become more evenly. Dy-doping led the grain size and cell volume increased and the optical band gap decreased.At the same time, the doping of Dy restrained the combination of CdO and made the thin film approach standard chemical ratio. The doping of La made the same influence in exterior status and optical characteristics except crystallography. CdS thin film doping La appeared faint hexangular crystal structure. KEYWORDS:chemical bath deposition; rare-earth doping; CdS; thin film...