OSA's Digital Library

Energy Express

Energy Express

  • Editor: Bernard Kippelen
  • Vol. 18, Iss. S3 — Sep. 13, 2010
  • pp: A403–A410

MgO nano-pyramids structure for enhancement of light extraction efficiency in vertical light-emitting diodes

Jun Ho Son, Hak Ki Yu, and Jong-Lam Lee  »View Author Affiliations

Optics Express, Vol. 18, Issue S3, pp. A403-A410 (2010)

View Full Text Article

Enhanced HTML    Acrobat PDF (1261 KB)

Browse Journals / Lookup Meetings

Browse by Journal and Year


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools



We demonstrate novel method for improving light extraction efficiency for n-side-up vertical InGaN/GaN light-emitting diodes (V-LEDs) using MgO nano-pyramids and ZnO refractive-index modulation layer. The MgO nano-pyramids structure is successfully fabricated on n-GaN/ZnO surface using electron-beam evaporation. The light output power of n-GaN/ZnO/MgO V-LEDs is enhanced by 49% compare to that of n-GaN V-LEDs. The angular-dependent far-field emission shows the significant increase of side emission for the n-GaN/ZnO/MgO V-LEDs due to the increase of critical angle for total internal reflection as well as the roughened surface by MgO pyramids structure. These experimental results indicate the critical role of surface texturing in improving the light extraction efficiency of the V-LEDs for solid-state lighting.

© 2010 OSA

OCIS Codes
(230.0230) Optical devices : Optical devices
(230.3670) Optical devices : Light-emitting diodes

ToC Category:
Light-Emitting Diodes

Original Manuscript: June 16, 2010
Revised Manuscript: August 12, 2010
Manuscript Accepted: August 12, 2010
Published: August 19, 2010

Jun Ho Son, Hak Ki Yu, and Jong-Lam Lee, "MgO nano-pyramids structure for enhancement of light extraction efficiency in vertical light-emitting diodes," Opt. Express 18, A403-A410 (2010)

Sort:  Author  |  Year  |  Journal  |  Reset  


  1. S. Noda and M. Fujita, “Light-emitting diodes: Photonic crystal efficiency boost,” Nat. Photonics 3(3), 129–130 (2009). [CrossRef]
  2. S. Pimputkar, J. S. Speck, S. P. DenBaars, and S. Nakamura, “Prospects for LED lighting,” Nat. Photonics 3(4), 180–182 (2009). [CrossRef]
  3. A. Hangleiter, D. Fuhrmann, M. Grewe, F. Hitzel, G. Klewer, S. Lahmann, C. Netzel, N. Riedel, and U. Rossow, “Towards understanding the emission efficiency of nitride quantum wells,” Phys. Status Solidi A 201(12), 2808–2813 (2004). [CrossRef]
  4. D. Fuhrmann, C. Netzel, U. Rossow, A. Hangleiter, G. Ade, and P. Hinze, “Optimization scheme for the quantum efficiency of GaInN-based green-light-emitting diodes,” Appl. Phys. Lett. 88(7), 071105 (2006). [CrossRef]
  5. E. F. Schubert, in Light Emitting Diodes, 2nd ed.
  6. T. Fujii, Y. Gao, R. Sharma, E. L. Hu, S. P. DenBaars, and S. Nakamura, “Increase in the extraction efficiency of GaN-based light-emitting diodes via surface roughening,” Appl. Phys. Lett. 84(6), 855 (2004). [CrossRef]
  7. C. H. Kuo, H. C. Feng, C. W. Kuo, C. M. Chen, L. W. Wu, and G. C. Chi, “Nitride-based near-ultraviolet light emitting diodes with meshed p‐GaN,” Appl. Phys. Lett. 90(14), 142115 (2007). [CrossRef]
  8. J. J. Wierer, A. David, and M. Megens, “III-nitride photonic-crystal light-emitting diodes with high extraction efficiency,” Nat. Photonics 3(3), 163–169 (2009). [CrossRef]
  9. M.-K. Kwon, J.-Y. Kim, I.-K. Park, K. S. Kim, G.-Y. Jung, S.-J. Park, J. W. Kim, and Y. C. Kim, “Enhanced emission efficiency of GaN/InGaN multiple quantum well light-emitting diode with an embedded photonic crystal,” Appl. Phys. Lett. 92(25), 251110 (2008). [CrossRef]
  10. J. K. Kim, S. Chhajed, M. F. Schubert, E. F. Schubert, A. J. Fischer, M. H. Crawford, J. Cho, H. Kim, and C. Sone, “Light-Extraction Enhancement of GaInN Light-Emitting Diodes by Graded-Refractive-Index Indium Tin Oxide Anti-Reflection Contact,” Adv. Mater. 20(4), 801–804 (2008). [CrossRef]
  11. H. Jia, L. Guo, W. Wang, and H. Chen, “Recent Progress in GaN-Based Light-Emitting Diodes,” Adv. Mater. 21(45), 4641–4646 (2009). [CrossRef]
  12. W. K. Wang, S. H. Huang, K. S. Wen, D. S. Wuu, and R. H. Horng, “Fabrication and efficiency improvement of micropillar InGaN/Cu light-emitting diodes with vertical electrodes,” Appl. Phys. Lett. 88(18), 181113 (2006). [CrossRef]
  13. S.-H. Huang, R.-H. Horng, S.-L. Li, K.-W. Yen, D.-S. Wuu, C.-K. Lin, and H. Liu, “Thermally Stable Mirror Structures for Vertical-Conducting GaN/Mirror/Si Light-Emitting Diodes,” IEEE Photon. Technol. Lett. 19(23), 1913–1915 (2007). [CrossRef]
  14. X.-M. Zhang, M.-Y. Lu, Y. Zhang, L.-J. Chen, and Z. L. Wang, “Fabrication of a High-Brightness Blue-Light-Emitting Diode Using a ZnO-Nanowire Array Grown on p-GaN Thin Film,” Adv. Mater. 21(27), 2767–2770 (2009). [CrossRef]
  15. M.-C. Jeong, B.-Y. Oh, M.-H. Ham, S.-W. Lee, and J.-M. Myoung, “ZnO-nanowire-inserted GaN/ZnO heterojunction light-emitting diodes,” Small 3(4), 568–572 (2007). [CrossRef] [PubMed]
  16. J.-L. Lee, M. H. Weber, J. K. Kim, and K. G. Lynn, “Positron annihilation study of Pd contacts on impurity-doped GaN,” Appl. Phys. Lett. 78(26), 4142 (2001). [CrossRef]
  17. C. Noguera, “Polar oxide surfaces,” J. Phys. Condens. Matter 12(31), 201 (2000). [CrossRef]
  18. M. Kästner and B. Voigtlander, “Kinetically Self-Limiting Growth of Ge Islands on Si(001),” Phys. Rev. Lett. 82(13), 2745–2748 (1999). [CrossRef]
  19. J. Goniakowski, F. Finocchi, and C. Noguera, “Polarity of oxide surfaces and nanostructures,” Rep. Prog. Phys. 71(1), 016501 (2008). [CrossRef]
  20. D. Wolf, “Reconstruction of NaCl surfaces from a dipolar solution to the Madelung problem,” Phys. Rev. Lett. 68(22), 3315–3318 (1992). [CrossRef] [PubMed]
  21. V. E. Henrich, “Thermal faceting of (110) and (111) surfaces of MgO,” Surf. Sci. 57(1), 385–392 (1976). [CrossRef]
  22. X.-S. Fang, C.-H. Ye, L.-D. Zhang, J.-X. Zhang, J.-W. Zhao, and P. Yan, “Direct observation of the growth process of MgO nanoflowers by a simple chemical route,” Small 1(4), 422–428 (2005). [CrossRef]
  23. Y.-J. Lin, C.-L. Tsai, Y.-M. Lu, and C.-J. Liu, “Optical and electrical properties of undoped ZnO films,” J. Appl. Phys. 99(9), 093501 (2006). [CrossRef]

Cited By

Alert me when this paper is cited

OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.

« Previous Article  |  Next Article »

OSA is a member of CrossRef.

CrossCheck Deposited