Investigations of the multi-pulsed emission characteristics of velvet

Study on the Electron Emission Properties of ZnO Nanorod Arrays on Different Substrates

“…8 The light emissions were considered as the emission from the plasma formed on the array surface. [8][9][10][11][12] The CCD images show the spatial distribution of emission sites and plasmas, moreover, there are no local enhancements of the plasma on the ZnO-NA surface. Whether the emission currents are high or low, the emission sites on the ZnO-NA surface are always distributed uniformly.…”

“…There is a great difference between the first pulse and the second pulse in the current intensity, this difference between emission currents attributes to the formation and expansion of the surface plasma. [8][9][10][11] During the second pulse, the highest emission currents of ZnO-NAs on silicon and stainless steel are 1582 and 2234 A respectively. Under the same pulse electric field, the emission current of ZnO-NAs on the stainless steel is much higher than that of the ZnO-NAs on the silicon.…”

“…The emission uniformity of ZnO-NAs is better than that of these traditional dielectric cathode materials such as velvets and carbon fibers. [9][10][11][12] The plasma forms on the cathode surface and would expand toward the anode due to the plasma density and temperature gradients. The expansion velocity of the plasma can be calculated by the experimental data.…”

“…The measurements under the DC electric field were carried out in a diode configuration, where base pressure was maintained at 1 × 10 −5 Pa. The anode-cathode gap d ak was 200 m and the voltage ranged from 1 to 1100 V. The high-voltage pulse emission experiment was performed in a diode powered by a pulse forming network generator at background pressure of 5×10 −4 Pa. 9 The generator outputted double-pulse with ∼100 ns duration, and the interval between two pulses was ∼400 ns. The anode-cathode gap d ak was 98 mm.…”

“…It is well known that plasma-flashover cathodes can generate intense current electron beams under pulse electric field, and which have been used extensively in high power microwave devices. [9][10][11][12] ZnO-NAs have great potential for * Author to whom correspondence should be addressed. the application in the plasma-flashover cathodes due to their excellent field emission properties.…”