Spectro-structural and microscopic studies on solution-grown CdS1-xTex thin films

Compositional, structural, microstructural and optical properties of thin films of CdS1-xTex (0# < x# < 1) prepared by the solution-growth technique are reported as a function of x. The film composition has been determined and compared with the bath composition. A non-linear relation has been found between them. The composites are crystalline in nature and pure CdS and CdTe existed in both hexagonal wurtzite and cubic zinc blende structures. Only wurtzite structure undergoes solid solution in the region 0# < x# < 0.1 and 0.9# < x# < 1. For 0.1 < x < 0.9 the films have been composed of the mixed phases of CdS and CdTe. The lattice parameters a and c vary with x following Vegard's law in the solid solution region. The surface topography showed polycrystalline texture with a rough surface and diffused grain structure. Optical studies revealed a high absorption coefficient (104-105cm-1) with direct type of transition.