铜纳米线填充氮化硼纳米管结构和电子特性的第一性原理研究

First-principles study of the structural and electronic properties of copper nanowire encapsulated into boron nitride nanotube

基于密度泛函理论框架下的第一性原理计算方法,研究了不同线径锯齿型氮化硼纳米管包裹五边形Cu纳米线复合系统的结构和电子特性。复合系统的圆筒状结构在弛豫后保持不变。计算结果表明,管-线间距约为0.34nm的CuNW@(14,0)复合系统的结构最稳定,且在费米能级附近处的能带结构为内部Cu纳米线和外部BN纳米管能带的叠加,同时Cu纳米线填充前后的量子电导不变。电荷密度分析表明,CuNW@(14,0)复合系统中传导电子仅分布在内部Cu纳米线区域,外部氮化硼纳米管相当于绝缘电缆壳。因此,该类型的纳米线缆复合系统有望应用于要求稳定传输电荷的纳机电系统和超大规模集成电路中。

By using the first-principles calculations based on the density functional theory, the structural and electronic properties of pentagonal Cu nanowires encapsulated in a series of zigzag （n,0） BNNTs have been systematically investigated. The initial shapes （cylindrical CuNWs and BNNTs） are preserved without any visible changes for the CuNW@ （n,0） combined systems. The most stabile combined system is CuNW@ （14,0） with an optimal tube-wire distance of about 0.34 nm and a simple superposition of the band structures of it% components （CuNW and （14,0） BNNT） near the Fermi level. A quantum conductance of 4G0 is obtained for both CuNW in either free-standing state or filled into BNNT. The charge density analyses also show that the electron transport will occur only through the inner CuNW and the inert outer BNNT serves well as insu- lating cable sheath. So the CuNW@ （14,0） combined system is top-priority in the ultra-large- scale integration （UI.SI） circuits and micro-electromechanical systems （MEMS） devices that de- mand steady transport of electrons.