OPTO-ELECTRICAL PROPERTIES OF In DOPED CdS THIN FILMS BY CO-SPUTTERING TECHNIQUE

Indium (In) doped CdS thin films has been prepared by co-sputtering of CdS and In target on glass substrates at 300 degrees C for a window layer of solar cells. UV-Vis, and Hall Effect measurements were performed to characterize the growth and doping impact of In in the CdS thin films. The experimental results show that the carrier concentration and Hall mobility increased with increasing In concentration at certain limits and then decreased with a further increase of In concentration, while the resistivity changed reversely. The optical band gap increased with increasing of In as well as electron concentration due to the increase of the Fermi level in the conduction band. The band gap was also decreased after a certain limit of In concentration. The highest carrier concentration and optical band gap was observed for the film of In RF power 0.5 watt/cm(2).