Abstract
The structural and electrical properties of the magnetron sputtered CdTe thin films with subsequent CdCl2 solution treatment have been studied with a major focus on the influence of CdCl2 treatment to achieve high quality thin films. In this study, CdTe films with a thickness of 1.5 to 2 mu m have been grown using the magnetron sputtering technique on top of glass substrate at an optimized substrate temperature of 250 degrees C. Aqueous CdCl2 concentration varied from 0.3 mol to 1.2 mol with the annealing temperature from 360 degrees C to 450 degrees C. The surface roughness of the films increases with the increase of solution concentration, while it fluctuates with the increase of annealing temperature. The density of nucleation centers and the strain increases for the films treated at 360 degrees C with 0.3 M to 1.2 M while the grain growth of the films reduces. However, these strains are released at higher annealing temperatures, resulting in reduced dislocation densities, structural defects as well as increased crystalline property and grain size. The carrier concentration increases with the increase of treated CdCl2 concentration and subsequent annealing temperature. The highest carrier concentration of 1.05 x 10(14)/cm(3) was found for the CdTe thin films treated with 0.3 M CdCl2 solution followed by an annealing treatment at 420 degrees C for 20 min. (C) 2013 Elsevier B.V. All rights reserved.