Light Extraction Enhancement of GaN-Based Light-Emitting Diodes Using Crown-Shaped Patterned Sapphire Substrates

Author

Chiu, Ching-Hsueh ; Hsu, Lung-Hsing ; Lee, Chia-Yu ; Lin, Chien-Chung ; Lin, Bo-Wen ; Tu, Shang-Ju ; Chen, Yan-Hao ; Liu, Che-Yu ; Hsu, Wen-Ching ; Lan, Yu-Pin ; Sheu, Jinn-Kong ; Lu, Tien-Chang ; Chi, Gou-Chung ; Kuo, Hao-Chung ; Wang, Shing-Chung ; Chan

Author_Institution

Dept. of Photonics, Nat. Chiao Tung Univ., Hsinchu, Taiwan

Volume

24

Issue

14

fYear

2012

fDate

7/15/2012 12:00:00 AM

Firstpage

1212

Lastpage

1214

Abstract

In this letter, we report the high performance GaN-based light-emitting diodes (LEDs) with embedded air void array grown by metal-organic chemical vapor deposition. The donut-shaped air void was formed at the interface between crown-shaped patterned sapphire substrates (CPSS) and the GaN epilayer by conventional photolithography. The transmission electron microscopy images demonstrate that the threading dislocations were significantly suppressed by epitaxial lateral overgrowth (ELOG). The Monte Carlo ray-tracing simulation reveals that the light extraction of the air-voids embedded LED was dramatically increased due to a strong light reflection and redirection by the air voids.

Keywords

III-V semiconductors; MOCVD; Monte Carlo methods; dislocations; gallium compounds; light emitting diodes; photolithography; ray tracing; sapphire; semiconductor epitaxial layers; transmission electron microscopy; wide band gap semiconductors; Al₂O₃; GaN; GaN epilayer; GaN-based light-emitting diodes; Monte Carlo ray-tracing; crown-shaped patterned sapphire substrates; donut-shaped air void; embedded air void array; epitaxial lateral overgrowth; light extraction enhancement; metal-organic chemical vapor deposition; photolithography; threading dislocations; transmission electron microscopy images; Epitaxial growth; Gallium nitride; Light emitting diodes; Optical variables control; Photonics; Substrates; Temperature measurement; Epitaxial lateral overgrowth; light-emitting diodes; metal–organic chemical vapor deposition;

fLanguage

English

Journal_Title

Photonics Technology Letters, IEEE

Publisher

ieee

ISSN

1041-1135

Type

jour

DOI

10.1109/LPT.2012.2195779

Filename

6188511