First-principles investigation on the field emission properties of B-doped carbon nanotubes

We have performed first-principles density-functional theoretical calculations to investigate the field emission properties of pristine and B-doped capped (5,5) single-walled carbon nanotubes. It is found that the work function of B-doped carbon nanotube increases drastically compared to that of pristine carbon nanotube, which means that the doping of boron atom leads to the impediment of the field emission properties for carbon nanotube. Due to the doping of boron atom, the lowest unoccupied molecular orbital decreases significantly, and the Fermi level shifts to the valence band. Consequently, the Fermi level is lowered, which will heighten the potential barrier of the electron emission for the carbon nanotube tip and impede the field emission. Furthermore, the tunneling probability of B-doped carbon nanotube also decreases significantly compared to that of pristine carbon nanotube, implying the impeditive effect of boron atom on the field emission properties of carbon nanotubes.