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Blue light emitting diode exceeding 100% quantum efficiency
Author(s) -
Piprek Joachim
Publication year - 2014
Publication title -
physica status solidi (rrl) – rapid research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.786
H-Index - 68
eISSN - 1862-6270
pISSN - 1862-6254
DOI - 10.1002/pssr.201409027
Subject(s) - light emitting diode , quantum well , optoelectronics , diode , tunnel junction , photon , quantum efficiency , band diagram , quantum , physics , materials science , electron , power (physics) , optics , band gap , quantum tunnelling , quantum mechanics , laser
InGaN/GaN light‐emitting diodes (LEDs) are known to exhibit a strongly non‐uniform vertical carrier distribution within the multi‐quantum well (MQW) active region. We propose to eliminate “dark” quantum wells by insertion of multiple tunnel junctions into the MQW which allow for the repeated use of electrons and holes for photon generation. In good agreement with available measurements, we demonstrate by self‐consistent numerical simulation that such tunnel junction LED design promises quantum efficiencies as high as 250% as well as a strongly enhanced output power at high input power, compared to conventional LED concepts.Energy band diagram and photon emission rate for the proposed LED with four sets of two quantum wells separated by three tunnel junctions. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)