ZnO films on transferable and low thermal resistance graphite substrate grown by ultrasonic spray pyrolysis

ZnO thin films were deposited on graphite substrates by ultrasonic spray pyrolysis method with Zn(CH3COO)2·2H2O aqueous solution as precursor. The crystalline structure, morphology, and optical properties of the as-grown ZnO films were investigated systematically as a function of deposition temperature and growth time. Near-band edge ultraviolet (UV) emission was observed in room temperature photoluminescence spectra for the optimized samples, yet the usually observed defect related deep level emissions were nearly undetectable, indicating that high optical quality ZnO thin films could be achieved via this ultrasonic spray pyrolysis method. Considering the features of transferable and low thermal resistance of the graphite substrates, the achievement will be of special interest for the development of high-power semiconductor devices with sufficient power durability.