Direct comparison of recombination dynamics in cubic and hexagonal GaN/AlN quantum dots

J. Simon, N. T. Pelekanos, C. Adelmann, E. Martinez-Guerrero, R. André, B. Daudin, Le Si Dang, and H. Mariette
Phys. Rev. B 68, 035312 – Published 14 July 2003
PDFExport Citation

Abstract

We report on time-integrated and -resolved photoluminescence (PL) data on self-assembled GaN quantum dots (QD’s) embedded in AlN, in both cubic [zinc-blende (ZB)] and hexagonal [wurtzite (Wz)] crystallographic phases. The comparison of the optical properties of ZB and Wz nitride QD’s allows us to distinguish pure dimensionality effects from the influence of the large polarization-induced electric fields present in the Wz nanostructures. Specifically, the PL energy of the ZB QD’s is always higher than the bulk cubic GaN band-gap energy, in contrast to the Wz QD’s where a 7-MV/cm polarization field gives rise to below-gap PL emission for sufficiently large QD’s. As a further consequence of the internal field, the low-temperature PL decay times of the Wz QD’s are significantly longer than the ZB ones, and increase strongly with the QD height in contrast to the ZB ones, which exhibit only a small size dependence. For both types of QD’s, the PL intensity is found to be weakly dependent on temperature, underscoring the strong zero-dimensional exciton localization in the GaN/AlN system. In spite of the strong localization, however, we show that the nonradiative channels cannot be neglected and have a significant contribution in the PL decay time for both ZB and Wz QD’s.

  • Received 9 July 2002

DOI:https://doi.org/10.1103/PhysRevB.68.035312

©2003 American Physical Society

Authors & Affiliations

J. Simon1,2, N. T. Pelekanos2, C. Adelmann1, E. Martinez-Guerrero1, R. André1, B. Daudin1, Le Si Dang1, and H. Mariette1

  • 1CEA-CNRS Joint Group Nanophysique et Semiconducteurs, Département de Recherche Fondamentale sur la Matière Condensée, CEA Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 9, FranceLaboratoire Spectrométrie Physique (CNRS UMR5588), Université J. Fourier, Grenoble I, BP 87, 38402 Saint Martin d’Hères Cedex, France
  • 2Microelectronics Research Group, FORTH/IESL, P.O. Box 1527, 71110 Heraklion, Greece

References (Subscription Required)

Click to Expand
Issue

Vol. 68, Iss. 3 — 15 July 2003

Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review B

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×