Efficiency droop in light‐emitting diodes: Challenges and countermeasures
TLDR
In this article, the authors present a theoretical model for the carrier leakage caused by the asymmetry of the pn junction, specifically the disparity between electron and hole concentrations and mobilities.Abstract:
Efficiency droop, i.e. the loss of efficiency at high operating current, afflicts nitride-based light-emitting diodes (LEDs). The droop phenomenon is currently the subject of intense research, as it retards the advancement of solid-state lighting which is just starting to supplant fluorescent as well as incandescent lighting. Although the technical community does not yet have consented to a single cause of droop, this article provides a summary of the present state of droop research, reviews currently discussed droop mechanisms, and presents a recently developed theoretical model for the efficiency droop. In the theoretical model, carrier leakage out of the active region caused by the asymmetry of the pn junction, specifically the disparity between electron and hole concentrations and mobilities, is discussed in detail. The model is in agreement with the droop's key behaviors not only for GaInN LEDs but also for AlGaInP LEDs.read more
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References
More filters
Journal ArticleDOI
Solid-State Light Sources Getting Smart
E. Fred Schubert,Jong Kyu Kim +1 more
TL;DR: The high efficiency of solid-state sources already provides energy savings and environmental benefits in a number of applications, but these sources also offer controllability of their spectral power distribution, spatial distribution, color temperature, temporal modulation, and polarization properties.
Journal ArticleDOI
Status and Future of High-Power Light-Emitting Diodes for Solid-State Lighting
Michael R. Krames,O.B. Shchekin,Regina B. Mueller-Mach,Gerd O. Mueller,Ling Zhou,Gerard Harbers,M. G. Craford +6 more
TL;DR: In this paper, the status and future outlook of III-V compound semiconductor visible-spectrum light-emitting diodes (LEDs) are presented and light extraction techniques are reviewed.
Journal ArticleDOI
Light-emitting diodes
TL;DR: Bergh and P.J.Dean as discussed by the authors proposed a light-emitting diode (LEDD) for light-aware Diodes, which was shown to have promising performance.
Journal ArticleDOI
Origin of efficiency droop in GaN-based light-emitting diodes
Min-Ho Kim,Martin F. Schubert,Qi Dai,Jong Kyu Kim,E. Fred Schubert,Joachim Piprek,Yongjo Park +6 more
TL;DR: In this paper, the efficiency droop in GaInN∕GaN multiple-quantum well (MQW) light-emitting diodes was investigated and it was shown that the droop is not related to MQW efficiency but rather to the recombination of carriers outside the MqW region.