IEEE Photonics Journal (Jan 2014)

Study of GaN LED ITO Nano-Gratings With Standing Wave Analysis

  • Gabriel Halpin,
  • Travis Robinson,
  • Xiaomin Jin,
  • Xiang-Ning Kang,
  • Guo-Ying Zhang

DOI
https://doi.org/10.1109/JPHOT.2014.2323296
Journal volume & issue
Vol. 6, no. 3
pp. 1 – 10

Abstract

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This study reveals the effect of nanoscale ITO transmission gratings on light emission from the top, sides, and bottom of a GaN light-emitting diode (LED), based on the substrate standing wave analysis. First, we show that sapphire substrate thickness affects the standing wave pattern in the LED and find the best- and worst-case sapphire thicknesses. Second, we find that adding nanoscale ITO transmission gratings can improve light extraction by 222% or 253%, depending on the reference chosen. Third, we observe that maximizing top light emission with the nano-grating can significantly reduce bottom and side light emissions. Finally, we study grating performance over different wavelengths and generate the LED spectrum.

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