Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1787710 | Current Applied Physics | 2011 | 5 Pages |
Abstract
Non-polar a-plane GaN layers were grown on planar and hemispherical micro- and nano-patterned r-sapphire substrates (PSS) by metal organic chemical vapor deposition (MOCVD). Double Crystal X-ray Rocking Curve (DCXRC) and Transmission Electron Microscopy (TEM) analyses showed that the crystal quality of a-GaN grown on the micro-PSS was the best among three kinds of r-sapphire substrates, which was attributed to defect reduction through lateral overgrowth on the hemispherical patterns. The intensity of the near band-edge emission (NBE) at 3.4eV from a-GaN on the micro-PSS was increased by about 30 times compared with that of the conventional a-plane GaN on planar r-sapphire, while the yellow emission spectrum at 2.2eV was the lowest among the three samples. Comparison of the micro-photoluminescence mapping image and the cross-section TEM also showed high and low defect regions on the planar section and hemisphere, respectively.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
Geunho Yoo, Hyunsung Park, Donghun Lee, Hyoungjin Lim, Seunga Lee, Bohyun Kong, Hyungkoun Cho, Hyoungwon Park, Heon Lee, Okhyun Nam,