Characterization of CdTe films with in situ CdCl2 treatment grown by a simple vapor phase deposition technique

A unique vapor phase deposition (VPD) technique was designed and built to achieve in situ CdCl2 treatment of CdTe film. The substrate temperature was 400 degrees C, and the temperature of CdTe mixture with CdCl2 source was 500 degrees C. The structural and morphological properties of CdTe have been studied as a function of wt.% CdCl2 concentration by using X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM) and atomic force microscopy (AFM). XRD measurements show that the presence of CdCl2 vapor induces (1 1 1)-oriented growth in the CdTe film. SEM measurements have shown enhance growth of grains, in the presence of CdCl2. From AFM the roughness of the films showed a heavy dependence on CdCl2 concentration. In the presence of 4% CdCl2 concentration, the CdTe films roughness has a root mean square (rms) value of about 275 A. This value is about 831 angstrom for the non-treated CdTe films. (c) 2009 Elsevier B.V. All rights reserved.