Increasing the Conductivity of Cadmium Telluride Films

Abstract

The structural , optical and electrical properties of vacuum-evaporated CdTe thin films were investigated as a function of post-deposition annealing without and with CdCl2 treatment at 300˚C for 15min . X-Ray diffraction studies of the asdeposited films revealed polycrystalline in nature with cubic structure . The intensity of the (111) peak increased with the CdCl2 annealing treatment , and there is an increasing in the grain sizes after the CdCl2 annealing treatment with voids around the grain boundaries from the surface morphologies after the CdCl2 annealing treatment . The optical band gap values , Eg , were 1.56, 1.54 and 1.38 eV for film deposited at room temperature and after annealing without and with CdCl2 treatment at 300˚C for 15min respectively . Furthermore , the activation energy decreases after heat treatment without and with CdCl2 for CdTe thin films.

Keywords

• cadmium telluride
• cdcl
• optical
• xray diffraction
• thin films