Preparation of CdTe Nuclear Detector Material in Thin Film Form using Thermal Evaporation Method

A study is initiated about cadmium telluride (CdTe) materials deposition and characterization for radiation detector application. The CdTe thin film was grown on glass substrate using thermal evaporation technique in vacuum to avoid the inclusion of impurities in the films. Three different samples were prepared where film thickness were 500, 600 and 700 nm measured by insitu quartz crystal thickness monitoring device during deposition process. The structural studies of the films were carried out using (X-ray diffraction) XRD analytical study and optical measurements were performed in the UV-VIS-NIR region using a spectrophotometer. The films grown at room temperature are polycrystalline as found by X-ray diffraction peaks. The optical transmission spectra of CdTe films showed a high transmission of about 85% to 90% in the visible region with a sharp fall near the fundamental absorption at 880 nm wavelength for the 500 and 600 nm films, and fundamental absorption at 1270 nm wavelength for 700 nm film.