Martinez de Arriba, G., Feng, P., Xu, C. et al. (3 more authors) (2022) Simple approach to mitigate the emission wavelength instability of III-nitride μLED arrays. ACS Photonics, 9 (6). pp. 2073-2078.
Abstract
III-nitride semiconductors and their heterojunctions exhibit intrinsic polarization due to the asymmetry of their wurtzite structure, which determines all the fundamental properties of III-nitride optoelectronics. The intrinsic polarization-induced quantum-confined Stark effect leads to an emission wavelength shift with increasing injection current for III-nitride visible LEDs, forming an insurmountable barrier for the fabrication of a full color display. For instance, a yellow LED designed to produce yellow light emits green or blue light at an elevated current, while a green (blue) LED gives off blue (violet) light with increasing current. This color instability becomes a serious issue for a microdisplay such as the displays for augmented reality (AR)/virtual reality (VR) typically utilized at proximity to the eye, where human eyes are sensitive to a tiny change in light color. It is well-known that an optical mode wavelength for a microcavity is insensitive to injection current. In this work, we have demonstrated an approach to epitaxially integrating microLEDs (green microLEDs as an example, one of the key components for a full color microdisplay) and a microcavity. This allows the emission from the microLEDs to be coupled with the microcavity, leading to a negligible emission wavelength shift with increasing injection current. In contrast, identical microLEDs but without a microcavity show a large emission wavelength shift from 560 nm down to 510 nm, measured under identical conditions. This approach provides a simple solution to resolving the 30-year issue in the field of III-nitride optoelectronics.
Metadata
Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2022 The Authors. Article available under the CC BY license (https://creativecommons.org/licenses/by/4.0/). | ||||
Keywords: | micro-LEDs; InGaN; QCSE; microcavity; mode wavelength; distributed Bragg reflector | ||||
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: |
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Depositing User: | Symplectic Sheffield | ||||
Date Deposited: | 31 May 2022 10:47 | ||||
Last Modified: | 11 Nov 2022 14:31 | ||||
Status: | Published | ||||
Publisher: | American Chemical Society (ACS) | ||||
Refereed: | Yes | ||||
Identification Number: | https://doi.org/10.1021/acsphotonics.2c00221 |