A study was made of the optical properties of non-polar GaN/(Al,Ga)N single quantum wells grown onto a- or m-plane GaN templates for Al contents below 15%. In order to reduce the density of extended defects, the templates were processed using the epitaxial lateral overgrowth technique. As expected for polarization-free heterostructures, the larger the quantum well width for a given Al content, the narrower the quantum well emission line. In structures with an Al content set to 5 or 10%, emission from excitons bound to the intersection of I1-type basal plane stacking faults with the quantum well was also observed. Similarly to what was seen in bulk material, the temperature dependence of basal plane stacking fault-bound quantum well exciton luminescence revealed intra-BSF localization. A qualitative model evidences the large spatial extension of the wave-function of these basal plane stacking fault-bound quantum well excitons, making them extremely sensitive to potential fluctuations located in and away from basal plane stacking faults. Finally, polarization-dependent measurements showed a strong emission anisotropy for basal plane stacking fault-bound quantum well excitons, which was related to their one-dimensional character and that confirmed that the intersection between a basal plane stacking fault and a GaN/(Al,Ga)N quantum well could be described as a quantum wire.

One-Dimensional Exciton Luminescence Induced by Extended Defects in Nonpolar GaN/(Al,Ga)N Quantum Wells. A.Dussaigne, P.Corfdir, J.Levrat, T.Zhu, D.Martin, P.Lefebvre, J.D.Ganière, R.Butté, B.Deveaud-Plédran, N.Grandjean, Y.Arroyo, P.Stadelmann: Semiconductor Science and Technology, 2011, 26[2], 025012