Photonic crystal structure effect on the enhancement in the external quantum efficiency of a red LED

Author

Kim, Taesung ; Leisher, Paul O. ; Danner, Aaron J. ; Wirth, Ralph ; Streubel, Klaus ; Choquette, Kent D.

Author_Institution

Univ. of Illinois Urbana-Champaign, Urbana, IL

Volume

18

Issue

17

fYear

2006

Firstpage

1876

Lastpage

1878

Abstract

The enhancement in external quantum efficiency of a red light-emitting diode (LED) from photonic crystal (PhC) hole patterns was investigated. A red LED was chosen because its epitaxial layers are relatively free from defects as compared to GaN-based LEDs. The peak emission wavelength was 642 nm, and a triangular-lattice PhC was designed with a hole diameter to lattice distance ratio of 0.5. The lattice distance to wavelength ratio (a/lambda) was varied from 0.2 to 4.6 in order to evaluate the enhancement in the external quantum efficiency. An improvement in efficiency greater than 75% was obtained for a/lambda between 0.6 and 2.0. This improvement of the optical characteristics occurred with unchanged electrical properties

Keywords

light emitting diodes; optical design techniques; photonic crystals; external quantum efficiency; lattice distance ratio; photonic crystal; red LED; Epitaxial layers; Flat panel displays; LED lamps; Lattices; Light emitting diodes; Manufacturing; Photonic crystals; Rough surfaces; Surface morphology; Surface roughness; Light-emitting diode (LED); photonic crystal (PhC);

fLanguage

English

Journal_Title

Photonics Technology Letters, IEEE

Publisher

ieee

ISSN

1041-1135

Type

jour

DOI

10.1109/LPT.2006.881235

Filename

1677643