Enhanced luminescent performance with surface wrinkled Al-doped ZnO films

To improve the photoluminescence (PL) properties of ZnO films, researchers generally preferred cations doping such as Al, but the effects of Al doping on the increase in PL intensity of ZnO films were dissatisfactory usually when surface of films was smooth. In this work, a new and simple process was proposed for enhancing the PL intensity in the range of 375–600 nm of ZnO films. We prepared surface wrinkled Al-doped ZnO (AZO) films by sol–gel method with a quickly pre-annealing process. The wrinkle morphology was found to provide a larger absorption and luminescence area. Results showed that the wrinkle surface as compared with the smooth surface could raise the PL intensity of AZO films to 4 times, which made ZnO further close to the application for ultraviolet and visible luminescent devices.