Growth and in-plane optical anisotropy of crystalline quality enhanced non-polar m-plane ZnO(GaN) films on trenched (100) LiAlO2 substrates

Non-polar m-plane ZnO thin films have been deposited on trenched (named S-1) and untrenched (named S-2) (1 0 0) LiAlO2 substrates by metal-organic chemical vapor deposition. The full-width at half-maximum (FWHM) value of the X-ray diffraction rocking curve for S, is much smaller, compared with that for S-2. Seen from the frequency shift for the E-2(high) mode of ZnO in the Raman spectra, S-1 is under a smaller compressive stress than S-2. Besides, the photoluminescence spectra show that S-1 has a smaller FWHM value (129 meV) for the near band edge emission than S-2 does (137 meV). Polarized Raman spectra and polarized optical transmission spectra show that m-plane ZnO film exhibits optical anisotropy. (C) 2008 Elsevier B.V. All rights reserved.