Efficiency droop in 245–247 nm AlGaN light-emitting diodes with continuous wave 2 mW output power
- 8 February 2010
- journal article
- research article
- Published by AIP Publishing in Applied Physics Letters
- Vol. 96 (6), 061102
- https://doi.org/10.1063/1.3302466
Abstract
We report on 245–247 nm AlGaN-based deep ultraviolet (DUV) light-emitting diodes with continuous wave output power up to 2 mW. DUV diodes with peak emission wavelength of 245 and 247 nm exhibit turn-on voltage less than 10 V. At room temperature and cw operation the maximum external quantum efficiency was close to 0.18%, which is the highest value published to date for devices with peak emission wavelength shorter than 250 nm. A large external efficiency droop observed at current densities above is attributed to self-heating, carrier spillover from the QWs into the barrier layers or the p-type cladding layer, and/or Auger recombination. A semiempirical equation was proposed to describe the efficiency droop in DUV diodes at a high current injection.
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