Anisotropic Properties of GaN Studied by Raman Scattering
The phonon anisotropy property of the GaN wurtzite crystal is studied using angular dependent Raman spectroscopy both theoretically and experimentally. The polarized Raman scattering spectra were recorded from cross-sections of c-axis oriented GaN films as a function of the angle between the incident laser polarization direction and the film normal direction in three different configurations. The Raman intensity of A1(TO) showed a sinusoidal dependence on the rotating angle, as also did the E1(TO) mode, while the E2 mode has a quite different behavior. The theoretical fit takes into account the susceptibility contribution and the phase differential of different vibrating elements.
Robert P. Devaty, David J. Larkin and Stephen E. Saddow
H.C. Lin et al., "Anisotropic Properties of GaN Studied by Raman Scattering", Materials Science Forum, Vols. 527-529, pp. 1517-1520, 2006