Heteroepitaxial growth of non-polar ZnO films on single crystal NdGaO3 (001) substrates by MOCVD

High-quality non-polar ZnO (11equation image0) films were epitaxially grown on single crystal NdGaO3 (NGO) (001) substrates. The non-polar ZnO (11equation image0) films were grown by metal organic chemical vapour deposition using Zn(C5H7O2)2 and O2 gas as starting materials. X-ray diffraction (XRD) peaks of ZnO (11equation image0) plane were observed in XRD patterns of 2?-? scans in all films. Rotation domains were not found in XRD f scan patterns of ZnO (11equation image0) films grown at a substrate temperature of 650 degrees C or less. XRD peaks of NGO (021) and ZnO (11equation image2) planes were observed at the same angle f in the XRD f scan patterns. The epitaxial relationship was ZnO (11equation image0)// NGO (001) and ZnO [0001] // NGO [010]. Lattice mismatch values along the ZnO [0001] direction and along the ZnO (1equation image00) direction were 5.36% and 3.70%, respectively. Growth rate was drastically decreased at the substrate temperature over 650 degrees C. Striped patterns along the ZnO [0001] direction were observed in atomic force microscopy images of ZnO (11equation image0) films grown at substrate temperatures of 600 and 650 degrees C. Emissions due to donor-bound excitions were observed in photoluminescence spectra of ZnO (11equation image0) films measured at 10 K. It is thought that NGO (001) substrates are useful for growth of high-quality non-polar ZnO (11equation image0) films. (C) 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)