Micro-Raman-scattering spectra of GaN films

The micro-Raman-scattering spectra were reported, which are at different points with different qualities of the GaN films grown on Al2O3 substrates by low pressure metallorganic chemical vapor deposition. The dependence of microstructure in the GaN film on the Raman scattering spectra was observed. It was confirmed that microstructure defects exist in the GaN film by X-ray diffraction analysis. According to the LO phonon-plasmon coupled theory and the results of Hall measurement, it was found that the slight shifting of A1(LO) mode comes from the inhomogeneity of strain, other than the LO phonon-plasmon interaction.EI06554-5582