Authors:	P. Vandersteegen, G. Schwartz, P. Bienstman, R. Baets
Title:	Luminous power efficiency optimization of a white organic light-emitting diode by tuning its spectrum and its extraction efficiency
Format:	International Journal
Publication date:	5/2008
Journal/Conference/Book:	Applied Optics
Volume(Issue):	47(3) p.1-9
DOI:	10.1364/ao.47.001947
Citations:	4 (Dimensions.ai - last update: 24/11/2024) 2 (OpenCitations - last update: 3/5/2024) Look up on Google Scholar
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Abstract

We show an increase of the luminous power efficiency of a white organic light-emitting diode (LED) with
three emitters by optimizing its spectrum and its extraction efficiency. To calculate this efficiency we use
a model with four parameters: the spectra, extraction efficiencies, internal quantum efficiencies of three
emitters, and the driving voltage. This luminous power efficiency increases by 30% by use of a spectrum
close to the spectrum of the MacAdam limit. This limit gives the highest luminous efficacy for a given
chromaticity. We also show that a white organic LED with an inefficient deep blue emitter can give
the same luminous power efficiency as a white organic LED with a more efficient light blue emitter,
because of their different fractions in the radiant flux. Tuning the extraction efficiency with a microcavity
to the spectrum also increases the luminous power efficiency by 10%.