The investigation of field emission properties of defective graphene-carbon nanotube composite

摘要

To improve the field emission properties of graphene-carbon nanotube composite, a defective model of graphene-carbon nanotube composite has been established in this study, for exploring the field emission properties of this composite, some efforts have been set on calculating binding energy, then energy level, local electron density distributions, Mulliken charge of the defective graphene-carbon nanotube composite have been analysed, work functions and ionisation potentials are calculated by first principles based on density functional theory (DFT) calculations. When the electric field is applied, the numerical value of band gap keeps in a limited scope, local electron density distribution also shows positive changes, Mulliken charge moves regularly and effectively, work functions and ionisation potentials descend significantly, all of these results we obtained show that the defective graphene-carbon nanotube composite can be used as a good candidate for field emission electron sources.