STRUCTURAL AND OPTICAL PROPERTIES OF UNDOPED AND Co DOPED ZnO NANOSTRUCTURED THIN FILMS

In this study ZnO:Co nano structured thin films doped with cobalt at different concentrations were deposited on glass substrates by the sol-gel dip coating method. Characterization techniques of XRD, SEM with EDAX, and UV-Visible spectra measurements were done to investigate the effects of the Co doping concentration on the optical and structural properties of the ZnO:Co nano structured thin films. The XRD patterns of all nano structured films show the crystalline behavior and are of a hexagonal wurtzite structure. Our results reveal that, with a high percent of cobalt, not only the degree of the crystalline behavior but also a broadening of the peak occurs. The compositional analysis was carried out by energy dispersive X-ray (EDX) measurement. The optical studies show that the band gap of ZnO:Co decreases the d electron of the Co atom and band carriers of the host material. This unique property of ZnCoO films can be used to fabricate transparent electrodes in flat panel displays and metal-insulator-semiconductor diodes.