One-dimensional exciton luminescence induced by extended defects in nonpolar GaN/(Al,Ga)N quantum wells. Auteur(s): Dussaigne Amélie, Corfdir Pierre, Levrat Jacques, Zhu T, Martin Denis, Lefebvre P., Ganière Jean-Daniel, Deveaud-Plédran Benoit, Grandjean Nicolas, Arroyo Y., Stadelmann P. (Article) Publié: Semiconductor Science And Technology, vol. 26 p.025012 (2010) Texte intégral en Openaccess : Ref HAL: hal-01260924_v1 DOI: 10.1088/0268-1242/26/2/025012 WoS: 000285621400014 Exporter : BibTex | endNote 15 Citations Résumé: 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. |