Poyiatzis, N., Bai, J., Smith, R.M. orcid.org/0000-0002-7718-7796 et al. (3 more authors) (2020) Optical polarization properties of (11–22) semi-polar InGaN LEDs with a wide spectral range. Scientific Reports, 10 (1). 7191.
Abstract
Electroluminescence polarization measurements have been performed on a series of semi-polar InGaN light emitting diodes (LEDs) grown on semi-polar (11–22) templates with a high crystal quality. The emission wavelengths of these LEDs cover a wide spectral region from 443 to 555 nm. A systematic study has been carried out in order to investigate the influence of both indium content and injection current on polarization properties, where a clear polarization switching at approximately 470 nm has been observed. The shortest wavelength LED (443 nm) exhibits a positive 0.15 polarization degree, while the longest wavelength LED (555 nm) shows a negative −0.33 polarization degree. All the longer wavelength LEDs with an emission wavelength above 470 nm exhibit negative polarization degrees, and they further demonstrate that the dependence of polarization degree on injection current enhances with increasing emission wavelength. Moreover, the absolute value of the polarization degree decreases with increasing injection current. In contrast, the polarization degree of the 443 nm blue LED remains constant with changing injection current. This discrepancy can be attributed to a significant difference in the density of states (DOS) of the valence subbands.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2020 The Authors. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Electronic and Electrical Engineering (Sheffield) |
Funding Information: | Funder Grant number SEREN PHOTONICS LTD None ENGINEERING AND PHYSICAL SCIENCE RESEARCH COUNCIL EP/M015181/1 ENGINEERING AND PHYSICAL SCIENCE RESEARCH COUNCIL EP/P006361/1 ENGINEERING AND PHYSICAL SCIENCE RESEARCH COUNCIL EP/P006973/1 |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 05 May 2020 08:43 |
Last Modified: | 05 May 2020 09:55 |
Status: | Published |
Publisher: | Island Press |
Refereed: | Yes |
Identification Number: | 10.1038/s41598-020-64196-w |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:160209 |