Thermal carrier emission and nonradiative recombinations in nonpolar (Al,Ga)N/GaN quantum wells grown on bulk GaN

Journal Article · Wed Feb 01 04:00:00 EST 2012 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3681816· OSTI ID:22038852

Corfdir, P; Dussaigne, A; Giraud, E; Ganiere, J -D; Grandjean, N; Deveaud-Pledran, B ^[1]; Teisseyre, H ^[2]; Suski, T; Grzegory, I ^[3]; Lefebvre, P ^[4]

---

1. Institute of Condensed Matter Physics, Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland)
2. Institute of Physics, Polish Academy of Sciences, 02-668 Warsaw (Poland)
3. Institute of High Pressure Physics, Polish Academy of Sciences, 01-142 Warsaw (Poland)
4. Laboratoire Charles Coulomb - UMR5221 - CNRS - Universite Montpellier 2, 34095 Montpellier (France)

We investigate, via time-resolved photoluminescence, the temperature-dependence of charge carrier recombination mechanisms in nonpolar (Al,Ga)N/GaN single quantum wells (QWs) grown via molecular beam epitaxy on the a-facet of bulk GaN crystals. We study the influence of both QW width and barrier Al content on the dynamics of excitons in the 10-320 K range. We first show that the effective lifetime of QW excitons {tau} increases with temperature, which is evidence that nonradiative mechanisms do not play any significant role in the low-temperature range. The temperature range for increasing {tau} depends on the QW width and Al content in the (Al,Ga)N barriers. For higher temperatures, we observe a reduction in the QW emission lifetime combined with an increase in the decay time for excitons in the barriers, until both exciton populations get fully thermalized. Based on analysis of the ratio between barrier and QW emission intensities, we demonstrate that the main mechanism limiting the radiative efficiency in our set of samples is related to nonradiative recombination in the (Al,Ga)N barriers of charge carriers that have been thermally emitted from the QWs.

• OSTI ID: 22038852
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 3 Vol. 111; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM COMPOUNDS
CHARGE CARRIERS
CRYSTALS
EXCITONS
GALLIUM NITRIDES
HOLES
LAYERS
LIFETIME
MOLECULAR BEAM EPITAXY
PHOTOLUMINESCENCE
QUANTUM WELLS
RECOMBINATION
SEMICONDUCTOR MATERIALS
TEMPERATURE DEPENDENCE
THERMOELECTRICITY
TIME RESOLUTION