Structural characterization of polycrystalline Cd-Te-In films

Polycrystalline Cd-Te-In films have been grown on glass substrates by close -spaced vapor transport combined with a free evaporation technique and the stoichiometric, structural and electrical properties were investigated as f unctions of In2Te3 concentration added in solid solution into the CdTe stru cture during In incorporation. Indium was introduced by evaporation during film preparation and the incorporation was controlled by the temperature of the In source. The composition of the films was investigated by Auger elec tron spectroscopy, showing that, when In concentration increases the Cd con centration decreases they have a similar value (approximate to 22 at. %) at about 750 degreesC In source temperature. The dark resistivity decreased m onotonically four orders of magnitude with the In2Te3 concentration and rea ched a minimum point. From the structural characterization employed it was shown that the In atoms are incorporated in two ways: (I) for as low-In con centration, the In atoms substitute the Cd atoms, decreasing the resistivit y; and (II) for high-In concentration, the In atoms form with the CdTe a so lid solution like (CdTe)(1-x)(In2Te3)(x). The x-ray spectra were calculated for In source temperatures of 550 and 750 degreesC using structure refinem ent by the Rietveld method and general structure analysis system software. A good agreement between experimental and calculated spectra was found for both temperatures. (C) 2001 American Vacuum Society.