Improvement in the intense pulsed emission stability of grown CNT films via an electroless plated Ni layer

Carbon nanotube (CNT) films were grown on silicon wafers with and without a nickel layer (Si-CNT and Ni-CNT) via the pyrolysis of iron phthalocyanine. The nickel layer was prepared using the electroless plating method. To study the emission stability of Si-CNT and Ni-CNT cathodes during intense pulsed emission, emission characteristics were measured repeatedly with a diode structure using a Marx generator as a voltage source. For the peak values of the pulsed voltage, which were in the range between 1.62–1.66 MV (corresponding to electric field intensities between 11.57–11.85 V/μm), the first cycle emission current was 109.4 A for Si-CNT and 180.5 A for Ni-CNT. By comparing the normalized emission currents of the Si-CNT and Ni-CNT cathodes, the improvement in the emission stability can be easily quantified. The number of emission cycles necessary for the peak current to decay from 100% to 50% increased from ∼3 for Si-CNT to ∼11 for a Ni-CNT film.