@article{df08d6bcc8c4431a8ce25306fe97c3cd,
title = "Effects of nanometer-scale photonic crystal structures on the light extraction from GaN light-emitting diodes",
abstract = "This paper reports on the effect of nanometer-scale photonic crystal structures on the enhancement of the light extraction in GaN light-emitting diodes. Photonic crystals with hole or pillar-patterned structures with lattice constants of 460, 600, 750, and 920 nm are fabricated on indium-doped tin oxide (ITO) electrodes and/or p-GaN layers using laser holography and reactive ion etching. It is found that the light extraction efficiency depends strongly on the distance between the photonic crystal and the active layer, as well as the lattice constant for both structures. Photonic crystal light-emitting diodes (LEDs) with a lattice constant of 750 nm and hole depths of 260 nm in the ITO layer show an increase in light extraction of up to 32%, compared to conventional LEDs, without degradation in the electrical properties while a maximum enhancement of 26% is obtained from the device with a lattice constant of 460 nm and pillar heights of 60 nm on the p-GaN layer. The dependence of the extraction efficiency on the lattice constant is also calculated using a 3-D finite-difference time-domain method and compared with experimental results.",
keywords = "Gallium nitride, light extraction efficiency, light-emitting diode, photonic crystals",
author = "Shin, {Young Chul} and Kim, {Dong Ho} and Chae, {Dong Ju} and Yang, {Ji Won} and Shim, {Jae In} and Park, {Joong Mok} and Ho, {Kai Ming} and Kristen Constant and Ryu, {Han Youl} and Kim, {Tae Geun}",
note = "Funding Information: Manuscript received December 17, 2009; revised March 15, 2010 and April 9, 2010; accepted April 26, 2010. Date of current version July 23, 2010. This work was supported by the National Research Foundation, Korea Government, under Grants KRF-2008-D00074, F01-2007-000-11760-0, and K20901000002-09E0100-00210, in part by the Industrial Technology Project, Ministry of Knowledge Economy, Korea, under Grant 10 031 811, and Seoul R&BD Program, under Grant WR080951. Y. C. Shin, D. H. Kim, D. J. Chae, J. W. Yang, and J. I. Shim are with the School of Electrical Engineering, Korea University, Seoul 136-075, Korea. J. M. Park is with the Ames Laboratory and Department of Physics, Iowa State University, Ames, IA 50011 USA. K.-M. Ho is with the Department of Physics and Astronomy, Iowa State University, Ames, IA 50011 USA. K. Constant is with the Department of Materials Science and Engineering, Iowa State University, Ames, IA 50011 USA. H. Y. Ryu is with the Department of Physics, Inha University, Incheon 402-751, Korea. T. G. Kim is with the Department of Electronic Engineering, Korea University, Seoul 136-075, Korea (e-mail: tgkim1@korea.ac.kr). Color versions of one or more of the figures in this paper are available online at http://ieeexplore.ieee.org. Digital Object Identifier 10.1109/JQE.2010.2049827",
year = "2010",
doi = "10.1109/JQE.2010.2049827",
language = "English",
volume = "46",
pages = "1375--1380",
journal = "IEEE Journal of Quantum Electronics",
issn = "0018-9197",
publisher = "Institute of Electrical and Electronics Engineers Inc.",
number = "9",
}