Structural and optical properties of Cd and Mg doped zinc oxide thin films deposited by pulsed laser deposition

The 7 wt % Cd doped and 15 wt % Mg doped ZnO thin films were deposited on quartz substrate by pulse laser deposition system. The structural and optical properties of the prepared ZnO, Cd: ZnO and Mg: ZnO films were investigated by X-Ray diffraction (XRD), photoluminescence and UV-Vis spectroscopy techniques. XRD results indicate that the doped ZnO films maintain wurtzite crystal symmetry without any defects and are oriented along c-axis. Photoluminescence studies show a sharp band edge emission peak at 384 nm for pure ZnO film. This peak is blue shifted to 381 nm with Cd doping and red shifted to 395 nm with Mg doping. UV visible absorption studies reveals a decrease in band gap with Cd doping and an increase in band gap with Mg doping.