THERMAL EFFECTS ON STRUCTURAL CHARACTERIZATION OF EVAPORATED CDTE-FILMS DURING AND AFTER DEPOSITION

CdTe films were thermally deposited onto amorphous substrates at diffe rent temperatures (25-250 degrees C). Post-annealing under vacuum at 3 00 degrees C for 2 h has been also carried out. Using X-ray diffractio n, the structural characteristics (preferential orientation, stoichiom etry, microstructural properties) have been studied. Due to the high d egree of preferred orientation, Voigt analysis of single reflection wa s used to determine the microstructural properties (crystallite size a nd microstrain). Raising the substrate temperature was observed to lea d to a decrease in both integrated intensity and degree of preferred o rientation as well as an increase in crystallite size and internal mic rostrain associated with improving the film stoichiometry. Post-anneal ing was found to increase the integrated intensity, the crystallite si ze and the degree of preferred orientation. On the other hand, it resu lted in a decrease of FWHM and microstrain. The relative change in suc h parameters decreases as the film thickness increased with a pronounc ed change in thinner films.