碳掺杂(9,0)型闭口硼氮纳米管场发射第一性原理研究

First-principles Study of Field Emission Properties for (9,0) BNNT Capped by C_(60) Semi-sphere and Doped with C Atom

本文运用第一性原理研究了(9,0)型闭口硼氮纳米管及其两种C掺杂体系的场发射性能。对三种纳米管体系的态密度、局域态密度、赝能隙、最高占据分子轨道/最低未占据分子轨道能隙和Mulliken电荷的分析结果表明,C替代顶层六元环中硼与氮原子的场发射性能分别最优和最差。由此可见,C掺杂改善硼氮纳米管场发射性能的关键在于被置换原子的种类。

The field emission properties of （9,0） BNNT capped by C60 semi-sphere and doped with C atom were investigated by the first-principles.The analytical results of the density of state and the locale density of state,the energy gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital,the pseudo gap as well as the Mulliken population indicate that the field emission properties of C-doped BNNT in which B or N is substituted by C respectively are the best and worst.Therefore,the enhancement of field emission properties of the doped BNNT above-mentioned depends mainly on the category of the substituted atoms.