1. Enhanced light extraction in GaN-based light-emitting diodes by evanescent wave coupling effect
- Author
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X. L. Wang, Ahmed Mohammed Jahir, Yukiko Hayashi, Mitsuaki Shimizu, Keigo Takeguchi, Tokio Takahashi, Guo-Dong Hao, and Hiroyuki Kishi
- Subjects
Evanescent wave ,Materials science ,business.industry ,Extraction (chemistry) ,General Engineering ,Physics::Optics ,General Physics and Astronomy ,law.invention ,Wavelength ,Optics ,Coupling effect ,law ,Optoelectronics ,business ,Diode ,Light-emitting diode - Abstract
Subwavelength-sized truncated cones satisfying the requirement for evanescent wave coupling effect at the emission wavelength were fabricated on the p-side of a GaN-based blue light-emitting diode (LED). The light-extraction efficiency increased by a factor of approximately 2.2 relative to that of a reference LED with a flat light-extraction surface. This light-extraction enhancement ratio is much larger than that realized by using conventional light-extraction techniques. The evanescent wave coupling effect appearing on the surface of the truncated-cone structure is believed to be the mechanism responsible for the large enhancement of light extraction.
- Published
- 2014
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