Structural and optical properties of nearly stress-free m-plane ZnO film on (100) γ-LiAlO2 with a GaN buffer layer by metal-organic chemical vapor deposition

(1 0 (1) over bar 0) m-plane ZnO film was epitaxially deposited on (1 0 0) gamma-LiAlO2 by metal-organic chemical vapor deposition at 600 degrees C with a GaN buffer layer. The epitaxial relationships between ZnO and GaN, GaN and (1 0 0) gamma-LiAlO2 were determined by X-ray diffraction Phi-scans. There exhibits very small decrease for the E-2 mode shift (0.3 cm (1)) of ZnO in the Raman spectrum, which indicates the epitaxial ZnO film was under a slight tensile stress (5.77 x 10(7) Pa). Unlike the highly strained a-plane ZnO, temperature dependent photoluminescence spectra show that the free A exiton emission was observed with the temperature <= 138 K. (C) 2009 Elsevier B. V. All rights reserved.