Structural and optical properties of silver-doped zinc oxide sputtered films

Silver-doped ZnO (SZO) films were prepared by rf magnetron sputtering on glass substrates with specially designed ZnO target. For the doping source for target, we use AgNO3 powder with a various mixing ratio (0, 2, and 4 wt.%). We investigated a dependency of coating parameter, such as dopant content, in target and substrate temperature on structural and optical properties of the as-grown SZO films. The SZO films have a preferred orientation in the (002) direction. As amounts of the Ag dopant in the target were increased, the crystallinity as well as the transmittance and optical band gap were decreased while those properties were degenerated at 200 °C. And as the substrate temperature was increased, the crystallinity and the transmittance were increased. In details, changes of optical band gap for the SZO films were explained with the data obtained by XRD, XPS and using near-edge X-ray absorption fine structure (NEXAFS) spectroscopy.