Enhanced output power of GaN-based LEDs with embedded AlGaN pyramidal shells

Shang Ju Tu, Jinn-Kong Sheu, Ming Lun Lee, Chih Ciao Yang, Kuo Hua Chang, Yu Hsiang Yeh, Feng Wen Huang, Wei-Chi Lai

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

In this article, the characteristics of GaN-based LEDs grown on Ar-implanted GaN templates to form inverted Al 0.27 Ga 0.83 N pyramidal shells beneath an active layer were investigated. GaN-based epitaxial layers grown on the selective Ar-implanted regions had lower growth rates compared with those grown on the implantation-free regions. This resulted in selective growth, and formation of V-shaped concaves in the epitaxial layers. Accordingly, the inverted Al 0.27 Ga 0.83 N pyramidal shells were formed after the Al 0.27 Ga 0.83 N and GaN layers were subsequently grown on the V-shaped concaves. The experimental results indicate that the light-output power of LEDs with inverted AlGaN pyramidal shells was higher than those of conventional LEDs. With a 20 mA current injection, the output power was enhanced by 10% when the LEDs were embedded with inverted Al 0.27 Ga 0.83 N pyramidal shells. The enhancement in output power was primarily due to the light scattering at the Al 0.27 Ga 0.83 N/GaN interface, which leads to a higher escape probability for the photons, that is, light-extraction efficiency. Based on the ray tracing simulation, the output power of LEDs grown on Ar-implanted GaN templates can be enhanced by over 20% compared with the LEDs without the embedded AlGaN pyramidal shells, if the AlGaN layers were replaced by Al 0.5 Ga 0.5 N layers.

Original languageEnglish
Pages (from-to)12719-12726
Number of pages8
JournalOptics Express
Volume19
Issue number13
DOIs
Publication statusPublished - 2011 Jun 20

Fingerprint

light emitting diodes
output
templates
ray tracing
escape
implantation
light scattering
injection
augmentation
photons
simulation

All Science Journal Classification (ASJC) codes

  • Atomic and Molecular Physics, and Optics

Cite this

Tu, Shang Ju ; Sheu, Jinn-Kong ; Lee, Ming Lun ; Yang, Chih Ciao ; Chang, Kuo Hua ; Yeh, Yu Hsiang ; Huang, Feng Wen ; Lai, Wei-Chi. / Enhanced output power of GaN-based LEDs with embedded AlGaN pyramidal shells. In: Optics Express. 2011 ; Vol. 19, No. 13. pp. 12719-12726.
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abstract = "In this article, the characteristics of GaN-based LEDs grown on Ar-implanted GaN templates to form inverted Al 0.27 Ga 0.83 N pyramidal shells beneath an active layer were investigated. GaN-based epitaxial layers grown on the selective Ar-implanted regions had lower growth rates compared with those grown on the implantation-free regions. This resulted in selective growth, and formation of V-shaped concaves in the epitaxial layers. Accordingly, the inverted Al 0.27 Ga 0.83 N pyramidal shells were formed after the Al 0.27 Ga 0.83 N and GaN layers were subsequently grown on the V-shaped concaves. The experimental results indicate that the light-output power of LEDs with inverted AlGaN pyramidal shells was higher than those of conventional LEDs. With a 20 mA current injection, the output power was enhanced by 10{\%} when the LEDs were embedded with inverted Al 0.27 Ga 0.83 N pyramidal shells. The enhancement in output power was primarily due to the light scattering at the Al 0.27 Ga 0.83 N/GaN interface, which leads to a higher escape probability for the photons, that is, light-extraction efficiency. Based on the ray tracing simulation, the output power of LEDs grown on Ar-implanted GaN templates can be enhanced by over 20{\%} compared with the LEDs without the embedded AlGaN pyramidal shells, if the AlGaN layers were replaced by Al 0.5 Ga 0.5 N layers.",
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Tu, SJ, Sheu, J-K, Lee, ML, Yang, CC, Chang, KH, Yeh, YH, Huang, FW & Lai, W-C 2011, 'Enhanced output power of GaN-based LEDs with embedded AlGaN pyramidal shells', Optics Express, vol. 19, no. 13, pp. 12719-12726. https://doi.org/10.1364/OE.19.012719

Enhanced output power of GaN-based LEDs with embedded AlGaN pyramidal shells. / Tu, Shang Ju; Sheu, Jinn-Kong; Lee, Ming Lun; Yang, Chih Ciao; Chang, Kuo Hua; Yeh, Yu Hsiang; Huang, Feng Wen; Lai, Wei-Chi.

In: Optics Express, Vol. 19, No. 13, 20.06.2011, p. 12719-12726.

Research output: Contribution to journalArticle

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AU - Tu, Shang Ju

AU - Sheu, Jinn-Kong

AU - Lee, Ming Lun

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AU - Lai, Wei-Chi

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