High intensity electron emission cathodes based on a well-aligned ZnO nanorod array were fabricated. An investigation of the properties of the plasma and the electron beams produced by ZnO nanorod array cathodes was presented. Intense current electron beams were obtained from the cathodes. At an electric field of 7–8V∕μm and pulse duration of ∼100ns, the highest emission current density reached 76–91A∕cm2. The production mechanism of the electron beams was the plasma-induced emission. The morphology and structure of the ZnO nanorod after the application of the accelerating pulses were characterized. The plasma expanded at a velocity of about 10.7cm∕μs during the pulse interval. Whether the emission currents are high or low, the plasma on the cathode surface were always distributed uniformly. The ZnO nanorod array cathodes are expected to be applied to high power vacuum electronic devices as electron beam sources.

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Articles you may be interested inHigh intensity, plasma-induced electron emission from large area carbon nanotube array cathodes Appl. Phys. Lett. 96, 073109 (2010); 10.1063/1.3313944Field emission properties of plasma treated multiwalled carbon nanotube cathode layers Relationship between field emission property and composition of carbon nanotube paste for large area cold cathode J.High intensity electron emission cathodes based on carbon nanotube films have been successfully fabricated. An investigation of the explosive field emission properties of the carbon nanotube cathode in a double-pulse mode was presented and a high emission current density of 309 A / cm 2 was obtained. The time-and-space resolution of the electron-beam flow from the cathode was investigated. The formation of the cathode plasma layer was proven and the plasma expanded at a velocity of ϳ7.8 cm/ s toward the anode. The formation of cathode plasma has no preferential position and the local enhancement of electron beams is random.

High intensity electron emission cathodes based on carbon nanotube films have been successfully fabricated. An investigation of the explosive field emission properties of the carbon nanotube cathode in a double-pulse mode was presented and a high emission current density of 245 A cm−2 was obtained. The formation of the cathode plasma layer was proved and the production process of the electron beams from the cathode was explained. The time and space resolution of the electron beams flow from the cathode was investigated. The plasma expanded at a velocity of ∼8.17 cm µs−1 towards the anode and influenced on the intensity and distribution of electron beams obviously. The formation of cathode plasma had no preferential position and the local enhancement of electron beams was random. This carbon nanotube cathode appears to be suitable for high-power microwave device applications.

The pursuit of electronic materials and devices with high dielectric breakdown strength (DBS), and the clarification of the dielectric breakdown mechanism are of great importance to scientific research and industry applications.