EFFECT OF INDIUM DOPING ON STRUCTURAL, OPTICAL AND ELECTRICAL PROPERTIES OF CADMIUM SULFIDE THIN FILMS

Indium doped CdS thin films, with different In/CdS ratios, were fabricated employing chemical bath deposition technique. The incorporation of indium was carried out in the first stages of the process. The effects of In-doping on structural, surface, optical and electrical properties were determined using X-Ray Diffraction (DRX), Scanning Electron Microscope (SEM), UV-VIS Spectroscopy and Hall Measurements respectively. XRD studies showed cubic structures for all samples and that In3+ ions where incorporated into the lattice substitutionally at low concentration, and interstitially at high concentration. SEM measurements revealed that films morphology was unaffected by indium doping. The transmittance of In doped films was above 70% for all samples and the calculated band gap was between 2.32 and 2.44 eV. The electrical properties show an increment in carrier concentration from 1.3 x 1015 cm-3 to 2 x 1016 cm-3 and decrease in the resistivity from 2.13 x 1016 Ω to 1.5 x 1015 Ω due to indium doping.