含反位缺陷碳化硅纳米管的电子结构和光学性质

Electronic Structure and Optical Properties of SiC Nanotubes with Antisite Defects

基于第一性原理计算,对含有SiC反位缺陷或CSi反位缺陷碳化硅纳米管的电子结构和光学性质进行了研究。SiC缺陷在纳米管的表面形成了凸起,CSi缺陷在纳米管的表面形成了凹陷;这两种缺陷都导致在纳米管的导带底附近形成了缺陷能级,使得纳米管表现出n型电导;导带顶到杂质能级间的跃迁使得纳米管的光学带隙呈现了减小的趋势。这些结果对碳化硅纳米管电子器件和光学器件的研究都有较重要的参考价值。

Based on first-principles investigation,electronic structure and optical properties of a singlewalled (9,0) SiC nanotube (SiCNT) with a Si C antiste defect or a CSi antisite defect are investigated. A Si C defect leads to the formation of a bump in the surface of the nanotube. Nevertheless,a CSi defect forms a depression. Both Si C defect and CSi defect induce a defect level near the bottom of the conduction band,which results in an n-type conductivity for the SiCNT. Electron transitions between the top of the valence band and the defect level narrows the optical band gap of the nanotube. These results are meaningful for investigations on SiCNT electronic devices and optical devices.