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Title: Effect of current waveform on the performance of phosphor converted nitride light emitting diodes

We investigate the influence of the current waveform on the efficiency and the emission spectra of white, high power InGaN light emitting diodes. We consider rectangular and trapezoidal current pulses, adjusted to provide the same number of charge carriers in the space charge region. Our measurements confirm the theoretical expectation that flattening of the pulse flank increases the power efficiency. This effect is stronger according to the current amplitude. The emission blue peak at trapezoidal pulses is slightly red-shifted compared to that one at rectangular pulses. This indicates a stronger effect of the quantum confined Stark effect for trapezoidal pulse driving.
Authors:
 [1] ;  [2]
  1. Zumtobel Lighting GmbH, Schweizerstr. 30, 6851 Dornbirn (Austria)
  2. Institut für Halbleiter- und Festkörperphysik, Johannes Kepler Universität, 4040 Linz (Austria)
Publication Date:
OSTI Identifier:
22275684
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 3; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CHARGE CARRIERS; COMPARATIVE EVALUATIONS; ELECTRIC CURRENTS; EMISSION SPECTRA; ENERGY EFFICIENCY; GALLIUM NITRIDES; INDIUM COMPOUNDS; LIGHT EMITTING DIODES; PERFORMANCE; PULSES; RED SHIFT; SPACE CHARGE; STARK EFFECT; WAVE FORMS