JSTS:Journal of Semiconductor Technology and Science

The Institute of Electronics and Information Engineers (대한전자공학회)
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Effects of Current Spreading in GaN-based Light-emitting Diodes Using ITO Spreading Pad

  • Kim, Jang Hyun (Inter-University Semiconductor Research Center and Department of Electrical Engineering and Computer Science, Seoul National University) ;
  • Kim, Garam (Inter-University Semiconductor Research Center and Department of Electrical Engineering and Computer Science, Seoul National University) ;
  • Park, Euyhwan (Inter-University Semiconductor Research Center and Department of Electrical Engineering and Computer Science, Seoul National University) ;
  • Kang, Dong Hoon (Samsung Electronics Co. Ltd.) ;
  • Park, Byung-Gook (Inter-University Semiconductor Research Center and Department of Electrical Engineering and Computer Science, Seoul National University)
  • Received : 2014.07.17
  • Accepted : 2014.12.29
  • Published : 2015.02.28
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Abstract

In conventional LEDs, a mesa-structure is usually used and it causes the current to be overcrowded in a specific region. We propose a novel structure of GaN-based LED to overcome this problem. In order to distribute the current in an active region, a spreading pad is inserted at the p-type region in the GaN based LED device. The inserted spreading pad helps the current flow because it is more conductive than the p-type GaN layer. By performing electrical and optical simulations, the effects of the spreading pad insertion are confirmed. The results of electrical simulation show that the current spreads more uniformly and more radiative recombination is produced as well. Moreover, from the optical simulation, it is revealed that the ITO is less absorptive material than p-GaN if the condition of specific wavelength sources is satisfied. Considering all of the results, we can conclude that the luminescent power is enhanced by the spreading pad.

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References

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