High performance CNT point emitter with graphene interfacial layer

Carbon nanotubes (CNTs) have great potential in the development of high-power electron beam sources. However, for such a high-performance electronic device, the electric and thermal contact problem between the metal and CNTs must be improved. Here, we report graphene as an interfacial layer between the metal and CNTs to improve the interfacial contact. The interfacial graphene layer results in a dramatic decrease of the electrical contact resistance by an order of 2 and an increase of the interfacial thermal conductivity by 16%. Such a high improvement in the electrical and thermal interface leads to superior field emission performance with a very low turn-on field of 1.49 V μm⁻¹ at 10 μA cm⁻² and a threshold field of 2.00 V μm⁻¹ at 10 mA cm⁻², as well as the maximum current of 16 mA (current density of 2300 A cm⁻²). (paper)