Citation
Dussaigne, A. and Corfdir, P. and Levrat, J. and Zhu, T. and Martin, D. and Lefebvre, P. and Ganiere, J.D. and Butte, R. and Deveaud-Pledran, B. and Grandjean, N. and Stadelmann, P.
(2011).
One dimensional exciton luminescence induced by extended defects in nonpolar (Al,Ga)N/GaN quantum wells.
"Semiconductor Science And Technology", v. 26
(n. 2);
pp..
ISSN 0268-1242.
https://doi.org/10.1088/0268-1242/26/2/025012.
Abstract
In this study, we present the optical properties of nonpolar GaN/(Al,Ga)N single quantum wells (QWs) grown on either a- or m-plane GaN templates for Al contents set below 15%. In order to reduce the density of extended defects, the templates have been processed using the epitaxial lateral overgrowth technique. As expected for polarization-free heterostructures, the larger the QW width for a given Al content, the narrower the QW emission line. In structures with an Al content set to 5 or 10%, we also observe emission from excitons bound to the intersection of I1-type basal plane stacking faults (BSFs) with the QW. Similarly to what is seen in bulk material, the temperature dependence of BSF-bound QW exciton luminescence reveals intra-BSF localization. A qualitative model evidences the large spatial extension of the wavefunction of these BSF-bound QW excitons, making them extremely sensitive to potential fluctuations located in and away from BSF. Finally, polarization-dependent measurements show a strong emission anisotropy for BSF-bound QW excitons, which is related to their one-dimensional character and that confirms that the intersection between a BSF and a GaN/(Al,Ga)N QW can be described as a quantum wire.
