Microstructure characteristics of ZnO thin films prepared by sol-gel method

ZnO thin films were prepared by sol-gel method, and the influence of spin-coated layers and annealing temperature on the sample crystal structure, optical properties and surface morphology were studied. X-ray diffraction (XRD) results show that the sample with 10 coated layers after annealing at 600 has a largest grain size and best crystallinity. The UV-Vis transmittance spectra are found to be steeper after annealing and the optical band gap decreases as the annealing temperature increasing. Photoluminescence spectra of ZnO films reveal the peak can be decomposed into two fitting peaks near 388 nm and 394 nm, corresponding to an intrinsic emission and a defect emission respectively, and the intensity of this two peaks show opposite changes as annealing temperature increasing. It is found that the samples present more uniform and compact surface as the annealing tempeature increasing. ©, 2015, Chinese Ceramic Society. All right reserved.