標題: | Catalyst-free GaN nanorods grown by metalorganic molecular beam epitaxy |
作者: | Kuo, SY Kei, CC Hsiao, CN Chao, CK Lai, FI Kuo, HC Hsieh, WF Wang, SC 光電工程學系 Department of Photonics |
關鍵字: | catalyst free;GaN nanorod;metalorganic molecular-beam epitaxy;nanotechnology |
公開日期: | 1-五月-2006 |
摘要: | High-density GaN nanorods with outstanding crystal quality were grown on c-sapphire substrates by radio-frequency plasma-assisted metalorganic molecular beam epitaxy under catalyst- and template-free growth condition. Morphological and structural characterization of the GaN nanorods was employed by X-ray diffraction, energy dispersive X-ray spectroscopy, scanning electron microscopy, and high-resolution transmission electron microscopy (HRTEM). These results indicate that the rod number density can reach 1 x 10(10) cm(-2) and the nanorods are well-aligned with preferentially oriented in the c-axis direction. Meanwhile, no metallic (Ga) droplet was observed at the end of the rods, which is the intrinsic feature of vapor-liquid-solid method. Nanorods with no traces of any extended defects, as confirmed by TEM, were obtained as well. In addition, optical investigation was carried out by temperature- and power-dependent micro-photoluminescence (mu-PL). The PL peak energies are red-shifted with increasing excitation power, which is attributed to many-body effects of free carriers under high excitation intensity. The growth mechanism is discussed on the basis of the experimental results. Catalyst-free GaN nanorods presented here might have a high potential for applications in nanoscale photonic devices. |
URI: | http://dx.doi.org/10.1109/TNANO.2006.874055 http://hdl.handle.net/11536/12281 |
ISSN: | 1536-125X |
DOI: | 10.1109/TNANO.2006.874055 |
期刊: | IEEE TRANSACTIONS ON NANOTECHNOLOGY |
Volume: | 5 |
Issue: | 3 |
起始頁: | 273 |
結束頁: | 277 |
顯示於類別: | 期刊論文 |