Stark effect in ensembles of polar (0001) Al{sub 0.5}Ga{sub 0.5}N/GaN quantum dots and comparison with semipolar (11−22) ones
Journal Article
·
· Journal of Applied Physics
- Centre de Recherche sur l'Hétéro-Epitaxie et ses Applications, CNRS, Rue Bernard Grégory, 06560 Valbonne (France)
- Laboratoire de Physique de la Matière Condensée, Faculté des Sciences de Tunis, 2092 El Manar (Tunisia)
- Department of Physics and KI for the NanoCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 305-701 (Korea, Republic of)
This work presents a continuous-wave photoluminescence study of Al{sub 0.5}Ga{sub 0.5}N/GaN quantum dots grown by ammonia-assisted molecular beam epitaxy on sapphire, either on the wurtzite polar (0001) or the semipolar (11−22) plane. Due to interface polarization discontinuities, the polar dots are strongly red-shifted by the Stark effect and emit in the visible range. Carrier injection screening of the polarization charges has been studied. A model relying on average dot heights and dot height variances, as measured by transmission electron microscopy, is proposed. It can account for the injection dependent luminescence energies and efficiencies. The electric field discontinuity deduced from the fittings is in good agreement with theoretical expectations for our barrier composition. On the contrary, semipolar quantum dot ensembles always emit above the gap of GaN strained to Al{sub 0.5}Ga{sub 0.5}N. Their luminescence linewidth is significantly lower than that of polar ones, and their energy does not shift with injection. Our study then confirms the expected strong decrease of the Stark effect for (11−22) grown (Al,Ga)N/GaN heterostructures.
- OSTI ID:
- 22308496
- Journal Information:
- Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 3 Vol. 116; ISSN JAPIAU; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
Similar Records
Built-in electric field and radiative efficiency of polar (0001) and semipolar (11–22) Al{sub 0.5}Ga{sub 0.5}N/GaN quantum dots
(11-22) semipolar InGaN emitters from green to amber on overgrown GaN on micro-rod templates
Estimation of the internal electric field inside (11-22) semipolar GaN/Al{sub 0.5}Ga{sub 0.5}N nanostructures and the radiative efficiency at low temperature
Journal Article
·
Tue Dec 03 23:00:00 EST 2013
· AIP Conference Proceedings
·
OSTI ID:22261947
(11-22) semipolar InGaN emitters from green to amber on overgrown GaN on micro-rod templates
Journal Article
·
Sun Dec 27 23:00:00 EST 2015
· Applied Physics Letters
·
OSTI ID:22486294
Estimation of the internal electric field inside (11-22) semipolar GaN/Al{sub 0.5}Ga{sub 0.5}N nanostructures and the radiative efficiency at low temperature
Journal Article
·
Wed May 21 00:00:00 EDT 2014
· Journal of Applied Physics
·
OSTI ID:22275513