Effect of sputtering parameters on photoluminescence properties of Al doped ZnO films deposited on Si substrates

Al-doped ZnO (ZnO:Al) films were deposited on glass and Si substrates using radio frequency reactive magnetron sputtering technique. Crystal structure, surface morphology and optical properties of ZnO:Al films on the different substrates were studied. Subsequently, effects of sputtering parameters, such as the substrate temperature, annealing temperature, sputtering power and ratio of oxygen to argon gas flow, on photoluminescence (PL) properties of ZnO:Al films on Si substrates were systematically investigated. The results indicated that high substrate temperature will create more defects resulting in the Auger effect and then the quenching of the light emission in ZnO films. However, annealing treatment and appropriate sputtering power can improve light emission efficiencies. ZnO:Al thin films grown on Si substrates are very important for improving the efficiencies of optoelectronic devices fabricated utilizing ZnO/Si heterostructures.