A novel approach to mass synthesis of raw CNTs for printed field emission cathodes by chemical vapour deposition

Using nickel foil as both substrate and catalyst, we report a simple, cheap and easily controllable thermal chemical vapor deposition (CVD) for mass synthesis of carbon nanotubes (CNTs). Grams of CNTs with high purity and good uniformity have been obtained on the nickel foil at 550 °C in a gas mixture of C2H2 and H2. The as-prepared CNTs were screen-printed on Ag electrodes patterned on glass to form field emission cathodes. The cathodes exhibit excellent field emission properties, with a turn-on field of 1.0 V/μm, the emission current density of 1 mA/cm2 at 2.5 V/μm, and uniform emission luminescence. This CVD method shows great promise in large-scale production of raw materials of CNTs for application of field emission display.