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Embeded photonic crystal at the interface of p-GaN and Ag reflector to improve light extraction of GaN-based flip-chip light-emitting diode

Authors :
Enqing Guo
Yingdong Tian
Ping Ma
Jinmin Li
Junxi Wang
Yonghui Zhang
Zhen Aigong
Liang Shan
Guo Shikuan
Liu Boting
Source :
Applied Physics Letters. 105:251103
Publication Year :
2014
Publisher :
AIP Publishing, 2014.

Abstract

In this experiment, a flip-chip light-emitting diode with photonic crystal was fabricated at the interface of p-GaN and Ag reflector via nanospheres lithography technique. In this structure, photonic crystal could couple with the guide-light efficiently by reason of the little distance between photonic crystal and active region. The light output power of light emitting diode with embedded photonic crystal was 1.42 times larger than that of planar flip-chip light-emitting diode. Moreover, the embedded photonic crystal structure makes the far-field divergence angle decreased by 18° without spectra shift. The three-dimensional finite difference time domain simulation results show that photonic crystal could improve the light extraction, and enhance the light absorption caused by Ag reflector simultaneously, because of the roughed surface. The depth of photonic crystal is the key parameter affecting the light extraction and absorption. Light extraction efficiency increases with the depth photonic crystal structure rapidly, and reaches the maximum at the depth 80 nm, beyond which light extraction decrease drastically.

Details

ISSN :
10773118 and 00036951
Volume :
105
Database :
OpenAIRE
Journal :
Applied Physics Letters
Accession number :
edsair.doi...........f1b5b7248f67ce391f57bd53a3c13236