Cai, Y. orcid.org/0000-0002-2004-0881, Haggar, J.I.H., Zhu, C. et al. (3 more authors) (2021) Direct epitaxial approach to achieve a monolithic on-chip integration of a HEMT and a single micro-LED with a high-modulation bandwidth. ACS Applied Electronic Materials, 3 (1). pp. 445-450. ISSN 2637-6113
Abstract
Visible light communications (VLC) require III-nitride visible micro-light-emitting diodes (μLEDs) with a high-modulation bandwidth. Such μLEDs need to be driven at a high injection current density on a kA/cm2 scale, which is about 2 orders of magnitude higher than those for normal visible LED operation. μLEDs are traditionally fabricated by dry-etching techniques where dry-etching-induced damages are unavoidable, leading to both a substantial reduction in performance and a great challenge to viability at a high injection current density. Furthermore, conventional biasing (which is simply applied across a p–n junction) is good enough for normal LED operation but generates a great challenge for a single μLED, which needs to be modulated at a high injection current density and at a high frequency. In this work, we have proposed a concept for an epitaxial integration and then demonstrated a completely different method that allows us to achieve an epitaxial integration of a single μLED with a diameter of 20 μm and an AlGaN/GaN high-electron-mobility transistor (HEMT), where the emission from a single μLED is modulated by tuning the gate voltage of its HEMT. Furthermore, such a direct epitaxial approach has entirely eliminated any dry-etching-induced damages. As a result, we have demonstrated an epitaxial integration of monolithic on-chip μLED-HEMT with a record modulation bandwidth of 1.2 GHz on industry-compatible c-plane substrates.
Metadata
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Copyright, Publisher and Additional Information: | © 2021 The Authors. Published by American Chemical Society. This is an open access article published under a Creative Commons Attribution (CC-BY) License, which permits unrestricted use, distribution and reproduction in any medium, provided the author and source are cited. (http://pubs.acs.org/page/policy/authorchoice_ccby_termsofuse.html) | ||||||||||
Keywords: | MicroLEDs; modulation bandwidth; GaN; selective overgrowth; HEMTs; VLC | ||||||||||
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: | 11 Feb 2021 16:45 | ||||||||||
Last Modified: | 11 Feb 2021 20:02 | ||||||||||
Status: | Published online | ||||||||||
Publisher: | American Chemical Society (ACS) | ||||||||||
Refereed: | Yes | ||||||||||
Identification Number: | https://doi.org/10.1021/acsaelm.0c00985 |