On the optical polarization properties of semipolar InGaN quantum wells

Polarized photoluminescence of strained quantum wells grown on c-plane, semipolar (10 (1) over bar2), (11 (2) over bar2), (10 (1) over bar1), (20 (2) over bar1) planes, and nonpolar GaN substrates was studied experimentally and in theory. The observed optical polarization switching between the substrate orientations (10 (1) over bar2) and (11 (2) over bar2) is in accordance with our general model of polarization switching, based on a (k) over right arrow . (p) over right arrow model of arbitrary substrate orientation. Spectrally resolved measurements of the polarization degree stemming from (10 (1) over bar2) samples show that the maximum of the polarization degree is red-shifted with respect to the maximum of the photoluminescence intensity. We ascribe this effect to an increased polarization of the transitions for higher indium content. (C) 2011 American Institute of Physics. [doi:10.1063/1.3618676]