Fabrication and characterization of Cd-enriched CdTe thin films by close spaced sublimation

Cd-enriched cadmium telluride (CdTe) polycrystalline films were grown on corning glass substrates by close spaced sublimation (CSS) technique. To our knowledge, Cd-enriched CdTe thin films by CSS have not been reported earlier. The structural investigations performed by means of X-ray diffraction (XRD) technique, scanning electron microscope (SEM), and energy dispersive X-ray spectroscopy (EDX) showed that the deposited films exhibit a polycrystalline structure with 〈111〉 as preferred orientation. The structural, optical, and electrical properties of these films were analyzed as a function of the Cd concentration. For the films having an excess of Cd, the electrical resistivity dropped several orders of magnitude. The deposited films also showed that the value of resistivity decreased with increasing temperature manifesting the semiconducting behavior of the films. The results showed that using this deposition technique, n-type Cd-enriched CdTe polycrystalline film could be produced.