Origin of efficiency droop in GaN-based light-emitting diodes

By Min-ho Kim, M. Schubert, Q. Dai, Jong Kyu Kim, E. Fred Schubert, J. Piprek, Yongjo Park. 2007

1,285 citations recorded by the source corpus.

The efficiency droop in GaInN∕GaN multiple-quantum well (MQW) light-emitting diodes is investigated. Measurements show that the efficiency droop, occurring under high injection conditions, is unrelated to junction temperature. Furthermore, the photoluminescence output as a function of excitation power shows no droop, indicating that the droop is not related to MQW efficiency but rather to the recombination of carriers outside the MQW region. Simulations show that polarization fields in the MQW and electron blocking layer enable the escape of electrons from the MQW region and thus are the physical origin of the droop. It is shown that through the use of proper quaternary AlGaInN compositions, polarization effects are reduced, thereby minimizing droop and improving efficiency.

Subfields: Atomic and Molecular Physics, and Optics, Condensed Matter Physics, Electrical and Electronic Engineering

View Paper: https://www.semanticscholar.org/paper/fb7aa40c0882a56ae79e532a1b86e53d80294761

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In Atomic and Molecular Physics, and Optics

In Condensed Matter Physics

In Electrical and Electronic Engineering

Citations in the corpus

Asymmetry of carrier transport leading to efficiency droop in GaInN based light-emitting diodes (2011, background): “Several mechanisms have been proposed to explain efficiency droop, including electron leakage due to polarization mismatch [1], poor hole injection [2], delocalization of carriers [3], and Auger recombination [4].”
LEDs for Solid-State Lighting: Performance Challenges and Recent Advances (2009, background): “measurements [59], [63], with opposing conclusions, and consensus on the carrier densities achieved in these measurements is needed.”
III-Nitride Photonics (2010, background): “Several factors have been suggested as potential reasons affecting the efficiencydroop in LEDs, however two leading theories have arisen, namely 1) carrier leakage process [27]– [30] or/and 2) Auger process in InGaN active region [34], [35].”
History of Gallium–Nitride-Based Light-Emitting Diodes for Illumination (2013, background): “As a result, high carrier densities are present in the active region, which exacerbate the effects of Auger recombination [68], [69] and, potentially, carrier oveflow leakage [70], [71], resulting in strong efficiency droop.”
Ultraviolet Detectors Based on Wide Bandgap Semiconductor Nanowire: A Review (2018, background): “GaN is the most popular semiconductor in the III-nitride material family [17,107,108].”
Semipolar $({\hbox{20}}\bar{{\hbox{2}}}\bar{{\hbox{1}}})$ InGaN/GaN Light-Emitting Diodes for High-Efficiency Solid-State Lighting (2013, background): “Several mechanisms have been proposed as the origin of efficiency droop, including Auger recombination [2]–[4], electron leakage [5], [6], and carrier delocalization to defects [7].”
Nonpolar and Semipolar III-Nitride Light-Emitting Diodes: Achievements and Challenges (2010, background): “Piezoelectric polarization and carrier overflow have been nominated as the causes [109]– [111].”