Optical and electrical characterization studies of chemically synthesized antimony-cadmium selenide thin films

CdSe:Sb thin films with Sb3+ doping concentration varied from 0 to 5 mol% were obtained onto the amorphous glasses by a chemical bath deposition. The deposits were smooth, well adherent to the substrate support, uniform and diffusely reflecting with color changing from dark-orange red to yellowish-orange as doping concentration was increased from 0 to 5 mol%. The XRD studies revealed the polycrystalline nature of the samples. The optical gaps were determined and found to be decreased from 1.79 eV to 1.61 eV for the increase in Sb3+ doping concentration from 0 to 0.1 mol% and it further increased with the increase in doping concentration. The transitions in these films were of the band-to-band direct type. The electrical conductivity is found to be enhanced with Sb3+ doping concentration from 0 to 0.1 mol% and then decreased with further addition of antimony content in CdSe. The activation energies were calculated in both the conduction regions. The other material characteristics such as thermoelectric power, carrier concentration (n), mobility (mu), barrier height (Phi(B)) were studied as a function of working temperature and antimony doping concentration in CdSe.