锥顶碳纳米管的结构稳定性与场致发射性能

运用密度泛函理论研究了锥顶碳纳米管的结构稳定性与电子场致发射性能.结果表明:在外电场作用下,该体系的结构稳定性明显优于碳纳米锥体、C₃₀半球封口的碳纳米管,且电子发射性能与锥角大小、锥顶构型密切相关,特别是锥角38.9°及棱脊型顶部的cone₁@(6,6)综合性能最优,用其作为场致发射源的阴极时可显著提高发射电流密度并延长器件的使用寿命.关键词：锥顶碳纳米管电子场致发射结构稳定性密度泛函理论

Structural stability and field emission propertiesof cone-capped carbon nanotubes

The structural stability and the electronic field emission properties of cone-capped carbon nanotubes have been deeply analyzed by the density functional theory. The results show that their structurs are much more stable than those of carbon nanocones and carbon nanotubes sealed with a C₃₀ hemisphere, and their electronic field emission properties are closely related to the configuration of cone apex and the magnitude of cone angle. Meanwhile, the combination property of cone₁@(6,6) with a ridge-shaped tip and 38.9° cone angle is optimal. When it is used as a field emission source the field emission current density and the lifetime of device will be remarkably increased.