Atomistic analysis of radiative recombination rate, Stokes shift, and density of states in c-plane InGaN/GaN quantum wells
McMahon, Joshua M.; Tanner, Daniel S. P.; Kioupakis, Emmanouil; Schulz, Stefan
Date:
2020-05-07
Copyright:
© 2020, the Authors. Published under license by AIP Publishing. This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared as: McMahon, J. M., Tanner, D. S. P., Kioupakis, E. and Schulz, S. (2020) 'Atomistic analysis of radiative recombination rate, Stokes shift, and density of states in c-plane InGaN/GaN quantum wells', Applied Physics Letters, 116(18), 181104 (5pp), doi: 10.1063/5.0006128, and may be found at https://doi.org/10.1063/5.0006128
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Access to this article is restricted until 12 months after publication by request of the publisher.
Restriction lift date:
2021-05-07
Citation:
McMahon, J. M., Tanner, D. S. P., Kioupakis, E. and Schulz, S. (2020) 'Atomistic analysis of radiative recombination rate, Stokes shift, and density of states in c-plane InGaN/GaN quantum wells', Applied Physics Letters, 116(18), 181104 (5pp). doi: 10.1063/5.0006128
Abstract:
Recent experimental studies have revealed an unusual temperature dependence of the radiative recombination rate in polar InGaN/GaN quantum wells. We show, by direct atomistic evaluation of the radiative recombination rate, that the experimentally observed trend of an increasing rate with increasing temperature results from the population of energetically higher lying electron and hole states with dipole matrix elements larger than those of the band edge states relevant to low temperature studies. Given that the overall evolution of this recombination rate is tightly linked to the energetic distribution of localized states, we investigate the hole density of states and absorption spectra. Based on the calculated absorption spectra, Stokes shift energies are extracted for InGaN quantum wells with In contents ranging from 5% to 25%. Here, good agreement with experimental literature results is found. We provide also hole tail state characteristic energies as a function of the In content, a quantity that indicates the localization character of the ensemble of hole states and which serves often as a key component in modified continuum-based models to capture carrier localization effects in transport or optical gain calculations.
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