Interface roughness, carrier localization, and wave function overlap in c-Plane (In,Ga)N/GaN quantum wells: interplay of well width, alloy microstructure, structural inhomogeneities, and Coulomb effects
| dc.contributor.author | Tanner, Daniel S. P. | |
| dc.contributor.author | McMahon, Joshua M. | |
| dc.contributor.author | Schulz, Stefan | |
| dc.contributor.funder | Science Foundation Ireland | en |
| dc.date.accessioned | 2019-02-27T12:35:20Z | |
| dc.date.available | 2019-02-27T12:35:20Z | |
| dc.date.issued | 2018-09-14 | |
| dc.date.updated | 2019-02-27T12:20:11Z | |
| dc.description.abstract | In this work, we present a detailed analysis of the interplay of Coulomb effects and different mechanisms that can lead to carrier-localization effects in c-plane (In,Ga)N/GaN quantum wells. As mechanisms for carrier localization, we consider here effects introduced by random alloy fluctuations as well as structural inhomogeneities such as well-width fluctuations. Special attention is paid to the impact of the well width on the results. All calculations have been carried out in the framework of atomistic tight-binding theory. Our theoretical investigations show that independent of the well widths studied here, carrier-localization effects due to built-in fields, well-width fluctuations, and random-alloy fluctuations dominate over Coulomb effects in terms of charge-density redistributions. However, the situation is less clear cut when the well-width fluctuations are absent. For a large well width (approximately >2.5nm), charge-density redistributions are possible, but the electronic and optical properties are basically dominated by the out-of-plane carrier separation originating from the electrostatic built-in field. The situation changes for lower well widths (<2.5nm), where the Coulomb effect can lead to significant charge-density redistributions and, thus, might compensate for a large fraction of the spatial in-plane wave-function separation observed in a single-particle picture. Given that this in-plane separation has been regarded as one of the main drivers behind the green gap problem, our calculations indicate that radiative recombination rates might significantly benefit from a reduced quantum-well-barrier-interface roughness. | en |
| dc.description.status | Peer reviewed | en |
| dc.description.version | Published Version | en |
| dc.format.mimetype | application/pdf | en |
| dc.identifier.articleid | 034027 | |
| dc.identifier.citation | Tanner, D. S. P., McMahon, J. M. and Schulz, S. (2018) 'Interface roughness, carrier localization, and wave function overlap in c-Plane (In,Ga)N/GaN quantum wells: interplay of well width, alloy microstructure, structural inhomogeneities, and Coulomb effects', Physical Review Applied, 10(3), 034027 (19pp). doi:10.1103/PhysRevApplied.10.034027 | en |
| dc.identifier.doi | 10.1103/PhysRevApplied.10.034027 | |
| dc.identifier.endpage | 19 | en |
| dc.identifier.issn | 2331-7019 | |
| dc.identifier.issued | 3 | en |
| dc.identifier.journaltitle | Physical Review Applied | en |
| dc.identifier.startpage | 1 | en |
| dc.identifier.uri | https://hdl.handle.net/10468/7550 | |
| dc.identifier.volume | 10 | en |
| dc.language.iso | en | en |
| dc.publisher | American Physical Society | en |
| dc.relation.project | info:eu-repo/grantAgreement/SFI/SFI Starting Investigator Research Grant (SIRG)/13/SIRG/2210/IE/Shaping the electronic and optical properties of non- and semi-polar nitride-based semiconductor nanostructures/ | en |
| dc.relation.uri | https://link.aps.org/doi/10.1103/PhysRevApplied.10.034027 | |
| dc.rights | © 2018, American Physical Society. All rights reserved. | en |
| dc.subject | Coulomb effects | en |
| dc.subject | Carrier-localization effects | en |
| dc.subject | c-plane (In,Ga)N/GaN quantum wells | en |
| dc.subject | Reduced quantum-well-barrier-interface roughness | en |
| dc.title | Interface roughness, carrier localization, and wave function overlap in c-Plane (In,Ga)N/GaN quantum wells: interplay of well width, alloy microstructure, structural inhomogeneities, and Coulomb effects | en |
| dc.type | Article (peer-reviewed) | en |
