CdCl(2)-treated CdTe thin films deposited by the close spaced sublimation technique

Cadmium telluride thin films were prepared by the close spaced sublimation (CSS) technique, using CdTe powder as evaporant and were submitted to a chemical treatment at 25A degrees C in a saturated CdCl(2) solution (2.08 g/100 mL methanol), followed by heat treatment under vacuum similar to 10(-3) mbar at 400A degrees C for 30 min. The effect of chemical and thermal treatments on the crystallographic, morphological, optical, and electrical properties were studied through XRD, scanning electron microscope (SEM), spectrophotometry, and dc electrical resistivity measurements, respectively. The studies revealed that the CdTe grows in face centered cubic phase and that post-deposition treatment affects the morphology as well as the crystallographic properties. The effect on the morphology is stronger. Increase of the grain size was observed in the samples treated thermally. The electrical resistivity drops by a factor of 20 in CdCl(2)-immersed and heated samples.