Influences of annealing on the optoelectronic properties of ZnO films grown by plasma-enhanced MOCVD

ZnO thin films have been grown on C-plane sapphire substrates by plasma-enhanced metal-organic chemical vapour deposition. The samples are then annealed at a higher temperature. The resistivity, concentration of electron, mobility and optically pumped threshold of both as-grown and annealed films are investigated. Furthermore, their structural and optical properties are also examined with x-ray diffraction, emission spectra and optical transmission spectra. The results indicate that the quality of ZnO thin films can be improved by annealing