Mechanism of enhanced light output in InGaN-based microlight emitting diodes
Choi, H. W. and Jeon, C. W. and Dawson, M. D. and Edwards, P. R. and Martin, R. W. and Tripathy, S. (2003) Mechanism of enhanced light output in InGaN-based microlight emitting diodes. Journal of Applied Physics, 93 (10). pp. 5978-5982. ISSN 0021-8979 (https://doi.org/10.1063/1.1567803)
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Abstract
Micro-light emitting diode (LED) arrays with diameters of 4 to 20 mum have been fabricated and were found to be much more efficient light emitters compared to their broad-area counterparts, with up to five times enhancement in optical power densities. The possible mechanisms responsible for the improvement in performance were investigated. Strain relaxation in the microstructures as measured by Raman spectroscopy was not observed, arguing against theories of an increase in internal quantum efficiency due to a reduction of the piezoelectric field put forward by other groups. Optical microscope images show intense light emission at the periphery of the devices, as a result of light scattering off the etched sidewalls. This increases the extraction efficiency relative to broad area devices and boosts the forward optical output. In addition, spectra of the forward emitted light reveal the presence of resonant cavity modes [whispering gallery (WG) modes in particular] which appear to play a role in enhancing the optical output.
ORCID iDs
Choi, H. W., Jeon, C. W., Dawson, M. D. ORCID: https://orcid.org/0000-0002-6639-2989, Edwards, P. R. ORCID: https://orcid.org/0000-0001-7671-7698, Martin, R. W. ORCID: https://orcid.org/0000-0002-6119-764X and Tripathy, S.;-
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Item type: Article ID code: 5231 Dates: DateEvent9 May 2003Published21 February 2003AcceptedSubjects: Science > Physics > Optics. Light Department: Faculty of Science > Physics > Institute of Photonics
Faculty of Science > PhysicsDepositing user: Strathprints Administrator Date deposited: 24 Jan 2008 Last modified: 02 Oct 2024 00:18 URI: https://strathprints.strath.ac.uk/id/eprint/5231