Increase in the Shockley–Read–Hall recombination rate in InGaN/GaN QWs as the main mechanism of the efficiency droop in LEDs at high injection levels

It is shown that the efficiency droop observed as the current through a GaN-based light-emitting diode increases is due to a decrease in the Shockley–Read–Hall nonradiative lifetime. The lifetime decreases with increasing current because a steadily growing number of traps in the density-of-states ta...

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Bibliographic Details
Published in:Semiconductors (Woodbury, N.Y.) N.Y.), 2015-12, Vol.49 (12), p.1665-1670
Main Authors: Bochkareva, N. I., Rebane, Yu. T., Shreter, Yu. G.
Format: Article
Language:English
Subjects:
CAPACITANCE
CORRELATIONS
DENSITY OF STATES
DIFFUSION BARRIERS
ELECTRONS
FERMI LEVEL
GALLIUM NITRIDES
HALL EFFECT
INDIUM COMPOUNDS
LIFETIME
LIGHT EMITTING DIODES
Liquors
Magnetic Materials
Magnetism
MATERIALS SCIENCE
N-TYPE CONDUCTORS
NANOSCIENCE AND NANOTECHNOLOGY
Optoelectronics industry
Physics
Physics and Astronomy
Physics of Semiconductor Devices
QUANTUM WELLS
RECOMBINATION
TRAPS
TUNNEL EFFECT
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Summary:It is shown that the efficiency droop observed as the current through a GaN-based light-emitting diode increases is due to a decrease in the Shockley–Read–Hall nonradiative lifetime. The lifetime decreases with increasing current because a steadily growing number of traps in the density-of-states tails of InGaN/GaN quantum wells become nonradiative recombination centers upon the approach of quasi-Fermi levels to the band edges. This follows from the correlation between the efficiency droop and the appearance of negative differential capacitance, observed in the study. The correlation appears due to slow trap recharging via the trap-assisted tunneling of electrons through the n -type barrier of the quantum well and to the inductive nature of the diode-current variation with forward bias.
ISSN:1063-7826
1090-6479
DOI:10.1134/S1063782615120040