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Title: Strong coupling of light with A and B excitons in GaN microcavities grown on silicon

Abstract

We present experimental results demonstrating strong-light matter coupling at low and room temperature in bulk GaN microcavities with epitaxial (Al,Ga)N Bragg mirrors grown on silicon (111). At low temperature, the strong coupling of both the A and B excitonic features of GaN with the cavity mode is clearly resolved in the microcavity. At room temperature a Rabi energy of 50 meV is observed and well reproduced using transfer-matrix reflectivity calculations describing the interaction of both the A and B excitonic states with the photonic mode.

Authors:
; ; ; ; ; ; ;  [1];  [2]
  1. CRHEA-CNRS, Rue Bernard Gregory, Parc Sophia Antipolis, Valbonne 06560 (France)
  2. (France)
Publication Date:
OSTI Identifier:
20787837
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. B, Condensed Matter and Materials Physics; Journal Volume: 73; Journal Issue: 3; Other Information: DOI: 10.1103/PhysRevB.73.033304; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALUMINIUM COMPOUNDS; COUPLING; EPITAXY; EXCITONS; GALLIUM NITRIDES; REFLECTIVITY; SEMICONDUCTOR MATERIALS; SILICON; TEMPERATURE DEPENDENCE; VISIBLE RADIATION

Citation Formats

Sellers, I. R., Semond, F., Leroux, M., Massies, J., Disseix, P., Henneghien, A-L., Leymarie, J., Vasson, A., and LASMEA, Universite Blaise Pascal, Clermont Ferrand II, Les Cezeaux, 63177 Aubiere Cedex. Strong coupling of light with A and B excitons in GaN microcavities grown on silicon. United States: N. p., 2006. Web. doi:10.1103/PHYSREVB.73.0.
Sellers, I. R., Semond, F., Leroux, M., Massies, J., Disseix, P., Henneghien, A-L., Leymarie, J., Vasson, A., & LASMEA, Universite Blaise Pascal, Clermont Ferrand II, Les Cezeaux, 63177 Aubiere Cedex. Strong coupling of light with A and B excitons in GaN microcavities grown on silicon. United States. doi:10.1103/PHYSREVB.73.0.
Sellers, I. R., Semond, F., Leroux, M., Massies, J., Disseix, P., Henneghien, A-L., Leymarie, J., Vasson, A., and LASMEA, Universite Blaise Pascal, Clermont Ferrand II, Les Cezeaux, 63177 Aubiere Cedex. 2006. "Strong coupling of light with A and B excitons in GaN microcavities grown on silicon". United States. doi:10.1103/PHYSREVB.73.0.
@article{osti_20787837,
title = {Strong coupling of light with A and B excitons in GaN microcavities grown on silicon},
author = {Sellers, I. R. and Semond, F. and Leroux, M. and Massies, J. and Disseix, P. and Henneghien, A-L. and Leymarie, J. and Vasson, A. and LASMEA, Universite Blaise Pascal, Clermont Ferrand II, Les Cezeaux, 63177 Aubiere Cedex},
abstractNote = {We present experimental results demonstrating strong-light matter coupling at low and room temperature in bulk GaN microcavities with epitaxial (Al,Ga)N Bragg mirrors grown on silicon (111). At low temperature, the strong coupling of both the A and B excitonic features of GaN with the cavity mode is clearly resolved in the microcavity. At room temperature a Rabi energy of 50 meV is observed and well reproduced using transfer-matrix reflectivity calculations describing the interaction of both the A and B excitonic states with the photonic mode.},
doi = {10.1103/PHYSREVB.73.0},
journal = {Physical Review. B, Condensed Matter and Materials Physics},
number = 3,
volume = 73,
place = {United States},
year = 2006,
month = 1
}
  • The reflectance spectra of simple design GaN-based microcavities have been studied in the 5 K-300 K range. The epitaxial structure consists of the silicon substrate and the stack of buffer layers as the back mirror, a GaN active layer, and a 100 A thick aluminium layer as the top mirror. Active layer thicknesses of {lambda}/2, {lambda}, or 3{lambda}/2 were investigated. The samples with GaN thicknesses {lambda}/2 and {lambda} display an anticrossing behavior between the cavity and exciton modes, with measured Rabi splittings of 47 and 60 meV, respectively, both at 5 K and room temperature.
  • Strong light-matter coupling is demonstrated at low temperature in an ultrathin GaN microcavity fabricated using two silica/zirconia Bragg mirrors, in addition to a three-period epitaxial (Al,Ga)N mirror serving as an etch stop and assuring good quality of the overgrown GaN. The {lambda}/2 cavity is grown by molecular beam epitaxy on a Si substrate. Analysis of angle-resolved data reveal key features of the strong coupling regime in both reflectivity and transmission spectra at 5 K: anticrossing with a normal mode splitting of 43{+-}2 meV and 56{+-}2 meV for reflectivity and transmission, respectively, and narrowing of the lower polariton linewidth near resonance.
  • Two routes for the fabrication of bulk GaN microcavities embedded between two dielectric mirrors are described, and the optical properties of the microcavities thus obtained are compared. In both cases, the GaN active layer is grown by molecular beam epitaxy on (111) Si, allowing use of selective etching to remove the substrate. In the first case, a three period Al{sub 0.2}Ga{sub 0.8}N/AlN Bragg mirror followed by a {lambda}/2 GaN cavity are grown directly on the Si. In the second case, a crack-free 2 {mu}m thick GaN layer is grown, and progressively thinned to a final thickness of {lambda}. Both devicesmore » work in the strong coupling regime at low temperature, as evidenced by angle-dependent reflectivity or transmission experiments. However, strong light-matter coupling in emission at room temperature is observed only for the second one. This is related to the poor optoelectronic quality of the active layer of the first device, due to its growth only 250 nm above the Si substrate and its related high defect density. The reflectivity spectra of the microcavities are well accounted for by using transfer matrix calculations.« less