Polarization switching phenomena in semipolar InxGa1-xN/GaN quantum well active layers

Abstract

We report the observation of optical polarization switching in InxGa1−xN/GaN quantum well active layers, using semipolar {11[overline 2]2} planes. When the In composition is less than ~30%, the emissions related to the top and second valence bands are polarized along the [1[overline 1]00] and perpendicular [[overline 1][overline 1]23] directions, respectively, similar to earlier studies. On the contrary, as the In composition increases above 30%, the polarizations switch, indicating a crossover between the two valence bands. Because the polarization degree is less sensitive to the well width, the observed polarization switch is ascribed to the InN deformation potentials.