中文摘要：

运用第一性原理研究了闭口硼氮纳米管（BNNT）顶层掺碳体系（C@BNNT）的电子场发射性能.结果表明：随外电场增强,C@BNNT电子结构变化显著,态密度（DOS）向低能方向移动;碳原子的局域态密度（LDOS）在费米能级附近明显增大;赝能隙、最高占据分子轨道（HOMO）/最低未占据分子轨道（LUMO）能隙减小;体系电荷移向帽端.DOS,HOMO/LUMO及Mulliken电荷分析一致表明,与BNNT相比,C@BNNT电子场发射性能显著改善,且C@BNmoreNT性能更优.

英文摘要：

The electron field emission properties of C-doped capped single-walled BNNT（C@BNNT）are investigated by first-principles study.The results show that with the increase of the applied electric field,the electronic structure of C@BNNT changes significantly,the density of states（DOS）shifts towards the low energy position,the local density of states（LDOS）at the Fermi level increases dramatically,the energy gap between the lowest unoccupied molecular orbital（LUMO）and the highest occupied molecular orbital （HOMO） decreases drastically and the electrons congregate to the capped side. The investigations of DOS, HOMO/LUMO and Mulliken population analysis indicate that, compared with pristine BNNT, the field emission properties of C@ BNNT, especially of C@ BNmcreNT, are greatly improved.