Influence of Heat Treatment on Crystal Structures and Luminescence Properties of ZnO Films Prepared by Sol-gel Method

ZnO films were prepared with sol-gel spin-coating method on Si(100) substrates.The crystal structures and luminescence properties of ZnO films were investigated by means of X-ray diffraction(XRD),photoluminescence(PL) and scan electron microscopy(SEM).The results showed that the thickness of ZnO films was about 220 nm with hexagonal wurtzite structures and the heat treatment temperature had great effect on c axis orientation.The PL spectra of the prepared ZnO films exhibited a strong UV emission that was not directly associated with the c axis orientation and a very weak visible luminescence band related to defects.