Improvement in the extraction efficiency of AlGaInP and GaN thin film LEDs via surface roughening

Y. J. Lee, H. C. Kuo, T. C. Lu, H. W. Huang, S. C. Wang, C. F. Lin

    Research output: Contribution to journalConference articlepeer-review


    In the first part of this paper, we present a LED structure adopting double diffused-surfaces on-top transmitted diffuse surface and another diffuse omnidirectional reflector surface on the bottom of LED chip. According to this design, guided light scattered by bottom diffuse omnidirectional reflectors can be again scattered toward to angles inside the escape cone by top diffuse transmittance surfaces. High light external efficiency (∼ 40%) was achieved on this novel structure. This high efficiency could be attributed to the strong scattering efficiency of using double diffuse surfaces, further reducing trapping of light within LED chips. In the second part, we present n-side-up AlGaInP-based LEDs with a triangle-like surface morphology using the adhesive layer bonding technique, followed by wet etching to roughen the surface. The novel AlGaInP LED design could not only reduce internal reflection between rear mirror systems and the semiconductor/air interface, but also to effectively scatter light outside LED devices. copyright The Electrochemical Society.

    Original languageEnglish
    Pages (from-to)199-211
    Number of pages13
    JournalECS Transactions
    Issue number5
    Publication statusPublished - 2006 Dec 1
    EventState-of-the-Art Program on Compound Semiconductors 45 (SOTAPOCS 45) -and- Wide Bandgap Semiconductor Materials and Devices 7 - 210th Electrochemical Society Meeting - Cancun, Mexico
    Duration: 2006 Oct 292006 Nov 3

    ASJC Scopus subject areas

    • Engineering(all)

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