Multi phonon resonant Raman scattering in GaN/AlxGa1-xN quantum wells

We report on Raman scattering experiments performed on GaN-AlGaN quantum we ll structures, using various ultraviolet excitations. Under near resonant c onditions we observe an important enhancement of the multi-LO phonon scatte ring in the wells or in the barriers. We find that the intensity of the pho non of the quantum wells increases with the barrier width. The latter obser vation may be attributed to effects related to the internal electrostatic f ield in the GaN wells.