Cadmium telluride (CdTe) is one of the important partners used in heterojunction solar cells and various other optoelectronic devices. Screen coating technique was employed to deposit CdTe thin films, on glass substrates at room temperature. The as-deposited films were gray in color and having thickness of 2 nm. Optical, structural, morphological and electrical properties of CdTe sintered films are reported in this paper. XRD analysis discovered that the as-prepared films were polycrystalline with a hexagonal crystal structure having preferred reflection (003), with a grain size of 47.54 nm. The abundance of Cd and Te elements in as-deposited films was ensured using the EDX technique. The FESEM micrograph showed uniform deposition of the material over entire glass substrate and film consists of interconnected grains of nanometer size. Compositional analysis showed that the nanocrystalline CdTe thick film becomes cadmium deficient and tellurium richer. The optical reflectance shows that the films have a direct band gap of 1.51 eV. The room temperature resistivity of the synthesized nanocrystalline CdTe thin films measured by two probe method was found to 5.68 x 105 Ω.cm. The activation energy (Eg) values at low and high-temperature regions were found to be 0.31 eV and 0.93 eV respectively. The as-prepared film possesses the p-type conductivity.
Keywords: Cadmium Telluride; Screen-Printing; Spectral Studies