Growth And Properties Of The Transparent ZnS Thin Film Material

In this paper,Zn/S/Zn(ZSZ)three-layer films were deposited by the sputtering and thermal evaporation.Then ZnS thin films were prepared by annealing the ZSZ films in Ar gas(pressure = 1 atm).The properties of the films were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),UV-VIS spectrophotometer.The effects of annealing and deposition time on the structural and optical properties of the ZnS thin films were studied.ZSZ films,after annealing in Ar gas,were converted to hexagonal ZnS thin films with a(111)-plane preferred orientation.Besides,these ZnS thin films exhibited the average transparency as high as ~80% in the visible region,with a good crystallinity,homogeneous distribution and high compactness in the film.An increase of annealing temperature can improve the crystallinity of ZnS thin films.And the optimum anneal temperature and time for the ZSZ films are 400 and ? 1h,respectively.It was found that S/Zn atomic ratios in ZSZ films can influence their optical properties.The excess sulfur or zinc in the ZSZ films led to their low optical transmittance.ZSZ films deposited under the optimum deposition time,after annealing at 400 for 1h?,were transformed into ZnS thin films,with an appropriate S/Zn atomic ratio and a good optical properties.Furthermore,the ZnS thin films had a band gap of 3.62 eV.