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Author Davies, M. J. ♦ Hammersley, S. ♦ Dawson, P. ♦ Massabuau, F. C. -P. ♦ Oliver, R. A. ♦ Kappers, M. J. ♦ Humphreys, C. J.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS ♦ DOPED MATERIALS ♦ ELECTRIC FIELDS ♦ EXCITATION ♦ GALLIUM NITRIDES ♦ OPTICAL PROPERTIES ♦ PHOTOLUMINESCENCE ♦ QUANTUM EFFICIENCY ♦ QUANTUM WELLS ♦ RECOMBINATION ♦ SPECTRA ♦ SPECTROSCOPY ♦ STARK EFFECT ♦ TEMPERATURE RANGE 0273-0400 K
Abstract In this paper, we report on a detailed spectroscopic study of the optical properties of InGaN/GaN multiple quantum well structures, both with and without a Si-doped InGaN prelayer. In photoluminescence and photoluminescence excitation spectroscopy, a 2nd emission band, occurring at a higher energy, was identified in the spectrum of the multiple quantum well structure containing the InGaN prelayer, originating from the first quantum well in the stack. Band structure calculations revealed that a reduction in the resultant electric field occurred in the quantum well immediately adjacent to the InGaN prelayer, therefore leading to a reduction in the strength of the quantum confined Stark effect in this quantum well. The partial suppression of the quantum confined Stark effect in this quantum well led to a modified (higher) emission energy and increased radiative recombination rate. Therefore, we ascribed the origin of the high energy emission band to recombination from the 1st quantum well in the structure. Study of the temperature dependent recombination dynamics of both samples showed that the decay time measured across the spectrum was strongly influenced by the 1st quantum well in the stack (in the sample containing the prelayer) leading to a shorter average room temperature lifetime in this sample. The room temperature internal quantum efficiency of the prelayer containing sample was found to be higher than the reference sample (36% compared to 25%) which was thus attributed to the faster radiative recombination rate of the 1st quantum well providing a recombination pathway that is more competitive with non-radiative recombination processes.
ISSN 00218979
Educational Use Research
Learning Resource Type Article
Publisher Date 2016-02-07
Publisher Place United States
Journal Journal of Applied Physics
Volume Number 119
Issue Number 5


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