Electronic Raman scattering from intersubband transitions in GaN/AlGaN quantum wells

We present a Raman scattering study of two GaN/AlxGa 1-xN multiple quantum well (MQW) structures with x = 0.3 and x = 0.4 and well widths of 6 nm and 4 nm respectively, they were nominally undoped but are expected to contain a low-density, n-type, carrier population due to the residual donors in the barriers. Polarization dependent Raman scattering was performed at room temperature, strong scattering due to in-tersubband transitions (ISBT's) in the GaN quantum wells was observed from both the e 1-e2 and e1-e3 transitions for both samples. The first sample has an e1-e2 transition at 300 meV and e1-e3 at 480 meV whilst the second sample has an e1-e2 transition at 360 meV and e1-e 3 at 580 meV. The full width half maximum of the Raman peaks is lower than that reported in infra-red absorption for similar, heavily doped, MQW structures. © 2003 WILEY-VCH Verlag GmbH & Co. KGaA.