Phonon-plasmon interaction in GaN films studied by Raman scattering

Abstract

GaN films of different buffer thicknesses (from 0 to 600 Angstrom) were grown on (0001) sapphire using MOCVD. The epitaxial films show autodoping with carrier concentration ranging from 8 x 10(16) to 5 x 10(17) cm(-3) as determined by Hall measurements. The Raman scattering reveals that the A(1)(LO) mode shifts from 733 to 740 cm(-1) as a result of the phonon-plasmon interaction.