Ab initio Study of Surface Passivation on the Physical Properties of (110) Silicon Nanowires

• Main Authors: Li-Ger Chen, 陳立格
• Other Authors: Guang-Yu Guo
• Format: Others
• Language: en_US
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/93540871981023105782

碩士 === 國立臺灣大學 === 物理研究所 === 95 === Silicon based technology is the fundament of electronic industry, such in transistors, solar cells and detectors. However, Silicon bulk is within a indirect band gap, so it is not good material for opticalelectronic device. Recent two years, development of nanotechnology have been demonstrated the silicon wires with nano-scale diameter, and many properties have been studied. Scientist have found the (110) direction silicon nanowires within a direct band gap, our researching fellow that. From 0.3 to 3.0nm,We have observed the variation of physical properties with different diameter and different surface passivation : H 、F、OH and CN. The total atom number is from 32 to 400 in an unit cell.Our research method is theoretical calculation based on density functional theory with local density approximation (LDA). We have found that the band gap indeed direct band gap in all our cases, and the gap remains 2.1eV with 3.0nm wire- the bulk band gap be 0.53eV. And values of the effective mass varied with different passivation are smaller than bulk. Our studies suggest F-passivated Si nanowires have the application potential of optoelectronics.