Physical properties of CdSexTe1-x thin films prepared by electrodeposition

Abstract

The cadmium chalcogenides CdSe_xTe_1-x (0≤x ≤1 ) thin films have been electrodeposited onto ITO coated glass substrates from an acid sulphate solution at 90 °C. The structure, the composition and the morphology have been studied as a function of the x coefficient by XRD, EDAX, optical absorbance and AFM techniques. All deposits have a cubic structure with a preferred orientation along the (111) direction. The composition in the films is found to vary linearly with the composition in the solution. The increase of the amount of tellurium in the CdSe_xTe_1-x films decreases the band gap down to 1.35 eV and increases the lattice constant. The photoelectrochemical studies in a polysulfide electrolyte show that CdSe_xTe_1-x thin films behave as n-type semiconductors.