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Proceedings Paper

Optimizing the external light extraction of nitride LEDs
Author(s): Emil Stefanov; Bryan S. Shelton; Hari S. Venugopalan; Tingting Zhang; Ivan Eliashevich
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Paper Abstract

In modern GaN-based light-emitting diodes (LEDs) structures, total internal reflection (TIR) limits light extraction, and consequently, overall efficiency of the light source. Proper chip and package material combinations as well as surface property modifications offer the opportunity to reduce the luminous flux lost due to TIR and absorption. Different sepa-ration techniques are taking influence on substrate surface properties and thus on light extraction improvement. Imple-menting all these factors in a flexible ray tracing model and applying effective mathematical optimization, helps to refine a chip design in a fast and accurate way to achieve a significant increase of the light extraction. Based on experimental data and ray trace modeling, the effects of chip size scaling, surface roughness and encapsulation on light extraction val-ues will be demonstrated.

Paper Details

Date Published: 26 November 2002
PDF: 12 pages
Proc. SPIE 4776, Solid State Lighting II, (26 November 2002); doi: 10.1117/12.457208
Show Author Affiliations
Emil Stefanov, GELcore (United States)
Bryan S. Shelton, GELcore (United States)
Hari S. Venugopalan, GELcore (United States)
Tingting Zhang, GELcore (United States)
Ivan Eliashevich, GELcore (United States)

Published in SPIE Proceedings Vol. 4776:
Solid State Lighting II
Ian T. Ferguson; Nadarajah Narendran; Steven P. DenBaars; Yoon-Soo Park, Editor(s)

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