Study of optical and structural properties of InN nano-dots grown at various temperature by metal organic chemical vapor deposition

• Main Authors: Shi-Kai Tai, 戴士凱
• Other Authors: Wei-Kuo Chen
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/47351112911719360998

碩士 === 國立交通大學 === 電子物理系所 === 95 === Photoluminescence（PL）and atomic force microscopy（AFM）measurements were used to investigate the optical properties and morphology of InN nanodots prepared by flow-rate modulation epitaxy at 550∼725 oC. In droplets were observed for samples grown at temperatures <575oC, as confirmed by both AFM and X-ray diffraction measurements, which can be attributable to the poor cracking efficiency of ammonia at this temperature range. Nevertheless, as the growth temperature is higher than 675oC, rapid declination in growth efficiency. It suggests that desorption of In adatom occurs at such a growth region instead. Concerning the optical properties, it is found that once the In droplets are formed, the optical properties of InN dots deteriorate significantly. As for droplet-free samples grown at temperatures �d600 oC, good luminescence properties are obtained. The corresponding PL peak energy is nearly independent（∼0.76 eV）of growth temperature, accompanied by a slight linewidth variation from 71 to 74 meV as the temperature varies from to . Furthermore, we also conducted temperature-dependent PL measurement. A clear redshift of 14∼20 meV were found in InN nanodot samples prepared at 675∼725 oC, suggesting good quality of our high-temperature InN samples.