Epitaxial growth of non-polar m-plane ZnO thin films by pulsed laser deposition

Non-polar ZnO thin films were deposited on m-plane sapphire substrates by pulsed laser deposition at various temperatures from 300 to 700 degrees C. The effects of growth temperature on surface morphology, structural, electrical, and optical properties of the films were investigated. All the films exhibited unique m-plane orientation indicated by X-ray diffraction and transmission electron microscopy. Based on the scanning electron microscopy and atomic force microscopy, the obtained films had smooth and highly anisotropic surface, and the root mean square roughness was less than 10 nm above 500 degrees C. The maximum electron mobility was similar to 18 cm(2)/V s, with resistivity of similar to 0.26 Omega cm for the film grown at 700 degrees C. Room temperature photoluminescence of the m-plane films was also investigated. (R) 2012 Elsevier Ltd. All rights reserved.