Property Study Of Ⅱ-Ⅵ Selenium Compound Thin Films Prepared By Vacuum Evaporation

Beyond 3 10-3 Pa vacuum degree ,three typical â…¡-â…¥ selenium compound thin films, ZnSe, CdSe, (Zn, Cd) Se, have been obtained by vacuum evaporation technique on the substrate of glass.In order to improve the crystallinity,we annealed the films in different temperature and time.By the measurement and analysis with the aid of X-Ray diffraction(XRD) and spectral photometer the structure and optic-characteristics of the films,and the effects of different technological conditions,are studied respectively before and after heat treatment.The results show we can obtain three typical â…¡-â…¥ films which have stable property and better crystallinity.At a substrate of room temperature,ZnSe films appear grayish and reddish black with low transmission.After heat treatment,thin films have high transmission in â…¥sible and near infrared spectral range. The intensity gradually strengthen till the annealing temperature reach 500 C.The CdSe films are difficult to obtain,compared and selected by some different technical conditions evaporation current and annealing temperature are too high to be useful to formation of the compound.Annealed thin films prefer orientation along crystal plane [100], they show better transmission of above 70 % .As for ternary compounds, by different choice of the chemical composition of Zn, Cd and Se powder,we can obtain uiform (Zn,Cd)Se thin films in proper technical conditions.Near infrared transmission strengthen with the increment of Zn content,whereas it is reversed with that of Cd.When the content of Zn and Cd was respectively increased,the intensity strengthen,but the cubic phase of thin films is not changed.