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A simple and cheap way to fabricate large area ZnO nanoemitter cold cathode was introduced. The properties of the cold cathode were characterized. The potential application of the cold cathode in flat panel light source was also discussed.
In this work a complete design of an electron gun with a cold cathode is described. The electron gun has been designed in order to be used in THz vacuum amplifiers or oscillators. The electron gun delivers a circular electron beam with a radius of 25 μm and current of about 1.4 mA. The electron gun operates at beam voltage of 10 kV and perveance of 0,0014 μP.
Carbon nanotube (CNT) is a type of ideal cathode materials for field emission (FE) devices. Its outstanding field emission properties can be attributed to high field enhancement on the tip due to its large aspect ratio. Early works reported that the field enhancement of CNTs in an array is strongly suppressed due to the screening effect. Further study confirmed that to avoid the screening effect,...
Summary form only given. We present the development of a plasma-enhanced chemical vapor deposition (PECVD) system for deposition of multi-walled, vertically aligned Carbon Nano-Tubes (CNT) as cathode field emitter sites in a large (1000 x 1000), 1 cm2 area array. The CNT deposition is compatible with the use of Si wafers containing the individual emitter site ballasts in the form of Si n-type JFETs...
We introduce a novel geometry carbon nanotube field emitter array capable of achieving high current densities. Arrays of patterned vertically aligned CNT bundles, with an open center similar to the structure of a donut, was grown directly on bulk metallic substrates. This new carbon nanotube structure, with larger edge area for enhanced edge effect, reached current densities as high as 60 mA/cm2 at...
We have studied two different kinds of electron tubes using a cold field emission cathode as the electron source. This cathode is an array of vertically aligned multiwall carbon nanotubes. The first device is a triode. With this device, we demonstrated the modulation at 32 GHZ of a 1.4 A/cm2 peak current density with a 82% modulation ratio. The second device is a traveling wave tube. For this device,...
We present a fabrication technique for the integration of a gate electrode with an array of carbon nanotube (CNT) emitters. These gated cathode structures have high emission current density and may be utilized in X-ray tubes, traveling wave tubes, and ion propulsion systems. The CNT emitters are grown directly on polished bulk metal substrates and are comprised of CNT bundles that are vertically aligned...
A complete microwave characterization of the small-signal properties in terms of S-parameters behaviors of a flip-chip triode geometry device has been studied with CST simulator. The simulation results of a single triode and 10times10 triode array have been proposed.
In this paper, we present an empirical study of dynamic behavior of an electron source system which incorporates an individual CNT. We propose a representative circuit model that is simple yet particularly valuable for emission current control for each CNT emitter in an array to facilitate high throughput maskless lithography.
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