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http://dx.doi.org/10.6117/kmeps.2015.22.4.071

Study on the Electrode Design for an Advanced Structure of Vertical LED  

Park, Jun-Beom (Optoelectronics Convergence Research Center, Chonnam National University)
Park, Hyung-Jo (Optoelectronics Convergence Research Center, Chonnam National University)
Jeong, Tak (New Light Source Center, Korea Photonics Technology Institute)
Kang, Sung-Ju (Applied Chemical Engineering, Chonnam National University)
Ha, Jun-Seok (Optoelectronics Convergence Research Center, Chonnam National University)
Leem, See-Jong (Department of Energy and Electrical Engineering, Korea Polytechnic University)
Publication Information
Journal of the Microelectronics and Packaging Society / v.22, no.4, 2015 , pp. 71-76 More about this Journal
Abstract
Recently, light emitting diodes (LEDs) have been studied to improve their efficiencies for the uses in various fields. Particularly in the aspect of chip structure, via hole type vertical LED chip is developed for improvement of light output power, and heat dissipations. However, current vertical type LEDs have still drawback, which is current concentration around the n-contact holes. In this research, to solve this phenomenon, we introduced isolation layer under n-contact electrodes. With this sub-electrode, even though the active area was decreased by about 2.7% compared with conventional via-hole type vertical LED, we could decrease the forward voltage by 0.2 V and wall-plug efficiency was improved approximately 4.2%. This is owing to uniform current flow through the area of n-contact.
Keywords
Light Emitting Diode; Via-hole; Current density; Wall plug efficiency;
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Times Cited By KSCI : 2  (Citation Analysis)
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1 M. F. Schubert, J. Xu, and J. K. Kim, "Polarization-matched GaInN/AlGaInN multi-quantum-well light-emitting diodes with reduced efficiency droop", Appl. Phys. Lett., 93, 041102 (2008).   DOI
2 S. Narukawa, "Ultra-High Efficiency White Light Emitting Diodes", Japanese Journal of Applied Physics, 45(41), L1084 (2006).   DOI
3 S. Narukawa, "Improvement of luminous efficiency in white light emitting diodes by reducing a forward-bias voltage", Japanese Journal of Applied Physics, 46(40), L963 (2007).   DOI
4 J. Xu and M. F. Schubert, "Reduction in efficiency droop, forward voltage, ideality factor, and wavelength shift in polarization- matched GaInN/GaInN multi-quantum-well lightemitting diodes", Appl. Phys. Lett., 94(1), 011113 (2009).   DOI
5 S. Nakamura and G. Fasol, "The Blue Laser Diodes; GaN based Light Emitter and Laser", Springer, Berlin (1997).
6 A. Mills, "Strategies in Light 2006: record LED sales but price erosion", III-Vs Review, 19(3), 35 (2006).   DOI
7 S. J. Lee, J. S. Lee, and Y. J. Kim, "Synthesis and optical properties of M-Si(Al)-O-N(M:Sr,Ca) phosphors for white light emitting diodes", J. Microelectron. Packag. Soc., 19(2), 41 (2012).   DOI
8 S. Noda and M. Fujita, "Light-emitting diodes: Photonic crystal efficiency boost", Nat. Photonics 3, 129 (2009).   DOI
9 J. J. Wierer, Jr., A. David, and M. M. Megens, "III-nitride photonic-crystal light-emitting diodes with high extraction efficiency", Nat. Photonics, 3, 163 (2009).   DOI
10 S. Pimputkar, J. S. Speck, S. P. DenBaars, and S. Nakamura, "Prospects for LED lighting", Nat. Photonics, 3, 180 (2009).   DOI
11 H. S. Kim, K. K. Kim, K. K. Choi, H. K. Kim, and J. O. Song, "Design of high-efficiency GaN-based light emitting diodes with vertical injection geometry", Appl. Phys. Lett., 91, 023510 (2007).   DOI
12 H. W. Jang, J. H. Lee, and J. L. Lee, "Characterization of band bendings on Ga-face and N-face GaN films grown by metalorganic chemical-vapor deposition", Appl. Phys. Lett., 80(21), 3955 (2002).   DOI
13 H. S. Kim, J. H. Ryou, Russell D. Dupuis, S. N. Lee, Y. J. Park, J. W. Jeon, and T. Y Seong, "Electrical characteristics of contacts to thin film N-polar n-type GaN", Appl. Phys. Lett., 93, 192106 (2008).   DOI
14 K. S. Lee, E. J. Kang, and S. J. Park, "Improved light-output and electrical performance of InGaN-based light-emitting diode by microroughening of the p-GaN surface", Journal of Applied Physics, 93(11), 9383 (2003).   DOI
15 T. Jang, S. N. Lee, O. H. Nam, and Y. Park, "Investigation of Pd/Ti/Al and Ti/Al ohmic contact materials on GaN-face and N-face surfaces of n-type GaN", Appl. Phys. Lett., 88, 193505 (2006).   DOI
16 J. B. Park, "Study on the electrode design for new structure of vertical LED using via-hole n-contact", Chonnam National University, (2014).
17 H. K. Rho and H. S. Ha, "The effects of size and array of N-GaN contacts on operation voltage of padless vertical light eitting diode", J. Microelectron. Packag. Soc., 21(1), 19 (2014).   DOI
18 M. H. Kim, M. F. Schubert, Q. Dai, and J. K. Kim, "Origin of efficiency droop in GaN-based light-emitting diodes", Appl. Phys. Lett., 91, 183507 (2007).   DOI