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

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7 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

All Science Journal Classification (ASJC) codes

  • Atomic and Molecular Physics, and Optics

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  • Cite this

    Tu, S. J., Sheu, J-K., Lee, M. L., Yang, C. C., Chang, K. H., Yeh, Y. H., Huang, F. W., & Lai, W-C. (2011). Enhanced output power of GaN-based LEDs with embedded AlGaN pyramidal shells. Optics Express, 19(13), 12719-12726. https://doi.org/10.1364/OE.19.012719