Polarization anisotropy of the photoluminescence of M-plane (In,Ga)N/GaN multiple quantum wells

We investigate the polarization anisotropy of the photoluminescence of an M-plane (1 (1) over bar 00) In0.1Ga0.9N/GaN multiple quantum well grown on gamma-LiAlO2 (100) by molecular-beam epitaxy. In contrast to C-plane (0001) structures, a strong in-plane optical anisotropy with an energy-dependent polarization degree of up to 96% is observed for this M-plane sample. An apparent spectral shift of the emission with polarization angle is attributed to the impact of exciton localization on the polarization degree. The presence of localized states manifests itself further in the anomalous temperature dependence of the photoluminescence linewidth. (C) 2003 American Institute of Physics.