標題: Efficiency enhancement of UV/blue light emitting diodes via nanoscaled epitaxial lateral overgrowth of GaN on a SiO2 nanorod-array patterned sapphire substrate
作者: Chiu, C. H.
Li, Zhen-Yu
Chao, C. L.
Lo, M. H.
Kuo, H. C.
Yu, P. C.
Lu, T. C.
Wang, S. C.
Lau, K. M.
Cheng, S. J.
電子物理學系
光電工程學系
光電工程研究所
Department of Electrophysics
Department of Photonics
Institute of EO Enginerring
關鍵字: Metalorganic chemical vapor deposition;Nanoscaled epitaxial lateral overgrowth;GaN
公開日期: 15-十一月-2008
摘要: High-quality GaN layer was successfully grown on a SiO2 nanorod-array patterned sapphire substrate (NAPSS) using metal-organic chemical vapor deposition by a nanoscaled epitaxial lateral overgrowth (NELO) method. From tunneling electron microscope images, well coalescence and turned dislocations are parallel to the surface direction were clearly observed. The Raman shift measurement shows the residual stress in GaN was greatly reduced from 1.359 to 0.652 GPa when compared to a GaN on flat sapphire substrate. Also, a high-efficiency GaN-based light-emitting diodes (LEDs) were demonstrated on the NELO NAPSS GaN, the respective output power and external quantum efficiency of the NELO NAPSS LEDs were estimated to be 22 mW and 40.2% at an injection current of 20 mA, showing an enhancement factor of 52% over conventional LEDs. The significant improvement resulted from both the enhanced light extraction assisted by the NAPSS, and the reduced dislocation densities using the NELO method. (c) 2008 Published by Elsevier B.V.
URI: http://dx.doi.org/10.1016/j.jcrysgro.2008.06.051
http://hdl.handle.net/11536/149716
ISSN: 0022-0248
DOI: 10.1016/j.jcrysgro.2008.06.051
期刊: JOURNAL OF CRYSTAL GROWTH
Volume: 310
起始頁: 5170
結束頁: 5174
顯示於類別:期刊論文