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Proceedings Paper

Extracting and directing light out of organic light emitting diodes (Presentation Recording)
Author(s): Uli Lemmer; Amos Egel; Matthias Hecht; Jan B. Preinfalk; Guillaume Gomard

Paper Abstract

Light extraction from organic light emitting diodes (OLEDs) is attracting considerable interest as being crucial for enhancing the energy efficiency in lighting applications. Light extraction can be realized by lithographically defined internal diffraction gratings or stochastic scattering centers. The former approach needs in addition an external optical layer for scrambling the angularly dependent emission spectra in order to avoid color shifts [1]. Micro lens arrays cannot only be used for fulfilling this task but they can also be used for enhancing the luminosity into a specific direction. We demonstrate recent advances towards high efficiency OLEDs with high directionality. In addition to the relevant technologies we have also developed a comprehensive simulation software for the quantitative description of the light propagation inside the devices. Here, a particular challenging task is the description of multiple and coherent optical scattering. We have recently developed a software for the exact simulation based on a scattering matrix formalism [2]. [1] T. Bocksrocker, J. B. Preinfalk, J. Asche-Tauscher, A. Pargner, C. Eschenbaum, F. Maier-Flaig and U. Lemmer, White organic light emitting diodes with enhanced internal and external outcoupling for ultra-efficient light extraction and Lambertian emission Opt. Expr. 20, A932 (2012). [2] A. Egel, U. Lemmer, Dipole emission in stratified media with multiple spherical scatterers: Enhanced outcoupling from OLEDs, Journal of Quantitative Spectroscopy and Radiative Transfer 148, 165 (2014).

Paper Details

Date Published: 5 October 2015
PDF: 1 pages
Proc. SPIE 9566, Organic Light Emitting Materials and Devices XIX, 95661D (5 October 2015); doi: 10.1117/12.2188526
Show Author Affiliations
Uli Lemmer, Karlsruher Institut für Technologie (Germany)
Amos Egel, Karlsruher Institut für Technologie (Germany)
Matthias Hecht, Karlsruher Institut für Technologie (Germany)
Jan B. Preinfalk, Karlsruher Institut für Technologie (Germany)
Guillaume Gomard, Karlsruher Institut für Technologie (Germany)

Published in SPIE Proceedings Vol. 9566:
Organic Light Emitting Materials and Devices XIX
Franky So; Chihaya Adachi; Jang-Joo Kim, Editor(s)

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