ZnO films on Al2O3 substrate were grown by using a pulsed laser deposition method. Through photoluminescence (PL) and X-ray diffraction (XRD) measurements, the optimum growth conditions for the ZnO growth were calculated. The results of the XRD measurement indicate that ZnO film was strongly oriented to the c-axis of hexagonal structure and epitaxially crystallized under constraints created by the substrate. The full-width half-maximum for a theta curve of the (0002) peak was 0.201 degrees. Also, from the PL measurement, the grown ZnO film was observed to be a free exciton, which indicates a high quality of epilayer. The Hall mobility and carrier density of the ZnO film at 293 K were estimated to be 299 cm(2)/V see and 8.27 x 10(16) cm(-3), respectively. The absorption spectra revealed that the temperature dependence of the optical band gap on the ZnO films was E-g(T) = 3.4393 eV - (5.30 x 10(-4) eV/KT2 /(367 + T). (c) 2005 Elsevier B.V. All rights reserved.