碳纳米锥电子场发射的第一性原理研究

First-principles study on field emission properties of carbon nanocone

运用第一性原理研究了不同锥角和结构的碳纳米锥(CNC)电子场发射性能.结果表明:随外电场(Eadd)增强,CNC电子结构变化显著,费米能级(Ef)处态密度(DOS)明显增大;赝能隙减小;体系电荷移向尖端.DOS,HOMO/LUMO及Mulliken电荷分析表明:CNC的电子场发射性能除依赖于尖端结构外,很大程度上还取决于锥角大小,特别顶层6个原子的CNC3和CNC4场发射性能更优.

The first-principles calculation was performed to study the electron field emission properties of carbon nanocones （CNC） with different cone angles and geometrical structures. The results show that with the increase of the applied electric field （E_add）, the electronic structure of CNC changes significantly, the density of states （DOS） shifts towards to low energy position. Especially, DOS at E_f increases and the pseudogap decreases respectively, and a majority of electrons congregate at the close end. The investigation of DOS, HOMO/LUMO and Mulliken population analysis indicates that CNC3 and CNC4 are very suited for electron field emission.