Theory of field evaporation and field emission from carbon nanotubes

Abstract

Field evaporation from carbon nanotubes has been investigated by the partitioned real-space density functional method. Field emission from graphitic ribbons (GR) has been investigated by the time-dependent density functional method. The activation energy for field evaporation highly depends on field strength and tip structures, and remarkably decreases by the adsorbed hydrogen (H). Field emission properties and currents drastically change by hydrogen termination on the GR edge. An important finding is that the emission current is higher from a clean zigzag GR (large work function) than from a H-terminated one (small work function).