氮掺杂对单壁碳纳米管的非平衡电子输运特性的影响

Effects of Nitrogen Substitutional Doping on the Nonequilibrium Electronic Transportation of Single Wall Carbon Nanotubes

利用结合了非平衡格林函数的第一性原理的局域密度泛函理论,研究了氮原子取代掺杂单壁碳纳米管的输运特性.计算结果表明,不同构形和不同数目的氮原子掺杂对(8,0)单壁碳管的输运性能有复杂的影响.研究发现,氮原子的掺杂提高了半导体型碳管的输运性能,电流-电压曲线呈非线性变化.对于浓度相同的氮掺杂,原胞内最近邻氮原子间距极大地影响了碳管的输运性能.因此,基于掺杂管的分子器件的设计中很有必要考虑这些因素.

Using density functional theory and nonequilibrium Green＇s functions,the effects of nitrogen substitution doping on the transportation in pristine （8,0） zigzag carbon nanotubes was investigated. The results show that the configuration and the concentration of the doped atoms have complicated effects on the transportation properties of the single wall carbon tubes. The transportation properties are improved by the doping of nitrogen atoms. The current-voltage curves show nonlinear variation, and the currents of doped tubes are sensitive to the impurity atoms＇ distribution in the cells for same concentration. Hence,it is necessary to consider these factors when designing molecular devices based on nitrogen-doped nanotubes.