Structural and Optical Properties of ZnO Epitaxial Films Grown on Al_2O_3 (1120) Substrates by Metalorganic Chemical Vapor Deposition

摘要

ZnO films of different thicknesses were grown on Al_2O_3 (1120) substrates by metalorganic chemical vapor deposition. Characterizations using X-ray diffraction and scanning electron microscopy demonstrated the transition from two-dimensional growth to three-dimensional growth with an increase in film thickness. Photoluminescence spectra revealed the thickness dependence of the exciton peak and a stimulated emission due to exciton-exciton scattering was observed.