Multiscale simulations of the electronic structure of III-nitride quantum wells with varied indium content: Connecting atomistic and continuum-based models
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Date
2021-02-18
Authors
Chaudhuri, Debapriya
O'Donovan, Michael
Streckenbach, T.
Marquardt, O.
Farrell, P.
Patra, Saroj K.
Koprucki, T.
Schulz, Stefan
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Publisher
American Institute of Physics
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Abstract
Carrier localization effects in III-N heterostructures are often studied in the frame of modified continuum-based models utilizing a single-band effective mass approximation. However, there exists no comparison between the results of a modified continuum model and atomistic calculations on the same underlying disordered energy landscape. We present a theoretical framework that establishes a connection between atomistic tight-binding theory and continuum-based electronic structure models, here a single-band effective mass approximation, and provide such a comparison for the electronic structure of (In,Ga)N quantum wells. In our approach, in principle, the effective masses are the only adjustable parameters since the confinement energy landscape is directly obtained from tight-binding theory. We find that the electronic structure calculated within effective mass approximation and the tight-binding model differ noticeably. However, at least in terms of energy eigenvalues, an improved agreement between the two methods can be achieved by adjusting the band offsets in the continuum model, enabling, therefore, a recipe for constructing a modified continuum model that gives a reasonable approximation of the tight-binding energies. Carrier localization characteristics for energetically low lying, strongly localized states differ, however, significantly from those obtained using the tight-binding model. For energetically higher lying, more delocalized states, good agreement may be achieved. Therefore, the atomistically motivated continuum-based single-band effective mass model established provides a good, computationally efficient alternative to fully atomistic investigations, at least at when targeting questions related to higher temperatures and carrier densities in (In,Ga)N systems.
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Keywords
III-N heterostructures , (In,Ga)N
Citation
Chaudhuri, D., O'Donovan, M., Streckenbach, T., Marquardt, O., Farrell, P., Patra, S. K., Koprucki, T. and Schulz, S. (2021) 'Multiscale simulations of the electronic structure of III-nitride quantum wells with varied indium content: Connecting atomistic and continuum-based models', Journal of Applied Physics, 129, 073104 (17). doi: 10.1063/5.0031514
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© 2021, 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(s) and AIP Publishing. This article appeared as: Chaudhuri, D., O'Donovan, M., Streckenbach, T., Marquardt, O., Farrell, P., Patra, S. K., Koprucki, T. and Schulz, S. (2021) 'Multiscale simulations of the electronic structure of III-nitride quantum wells with varied indium content: Connecting atomistic and continuum-based models', Journal of Applied Physics, 129, 073104 (17), doi: 10.1063/5.0031514, and may be found at https://doi.org/10.1063/5.0031514