Abstract
The influence of CdCl2 treatment on the properties of thermally evaporated CdTe thin film was investigated in this analysis to achieve high quality thin films. Thin films of CdTe were deposited on cleaned soda lime glass substrates at room temperature by thermal evaporation technique. Then the samples were treated by CdCl2 and subsequently annealed at annealing temperature of 400 degrees C for 15 minutes. The structural, optical and electrical properties of the grown samples were investigated through XRD, AFM, UV-Vis spectrometry and Hall-effect measurement analysis. The as-deposited films prepared at 25A were found in polycrystalline form, whereas the films prepared at deposition current of 28A and 30A exhibit cubic crystallinity with (111) preferential orientation around 2 theta=23.8 degrees. The crystallinity and the carrier concentration of the films were improved for all the CdCl2 treated films. The surface roughness of the films was also highly affected by the CdCl2 treatment as it was observed from AFM images. The bandgap has been found around 1.43 eV for the as-deposited films whereas the bandgap decreased to 1.4 eV after CdCl2 treatment. The values of mobility, resistivity and Hall coefficient were observed to decrease after the CdCl2 treatment.