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Low-threshold field emission is the intrinsic property for nanocarbon materials. Emission characteristics of planar field cathodes with carbon nanotubes (CNT) deposited from solution to Si, Al, Pd substrates were studied. The field emission threshold value for horizontally aligned CNT was found as low as 4 V/μm. However, the field enhancement in these samples is negligible (<10). We propose to...
In this work we present the development of a Carbon Nanotubes based multifinger microtriodes. Such device represents a viable and optimized alternative to the standard Spindt-type microtriode. The main improvement of the multifinger geometry consists on the possibility to reduce the cathode-grid capacitance by reducing the overlap between the two electrodes using a parallel patterning of the metallic...
Carbon nanotubes (CNTs) have attracted considerable attention due to their unique structure, remarkable properties, and their potential for a variety of applications, since their discovery by Iijima in 1991.The nanotube's high field enhancement, high aspect ratios, small tip radii of curvature and high current density make it a nearly ideal electron source for field emission. This paper discusses...
Study has been carried out into the key technological issues related to the fabrication of 4.3-inch CNT field emission flat panel light source. Controlled growth and post treatments are found to be effective approaches for achieving uniform luminescence of the light source.
In this work, we report results showing a correlation between the curvature of PDMS-supported CNT-tip arrays and their emission properties. CNTs were produced by using a hot-filament chemical-vapor-deposition (HFCVD) setup. VA-CNTs were synthesized using 28-Torr mixtures of methane (20 SCCM) and hydrogen (30 SCCM) as feedstock. Temperatures of filaments and substrates were 2050 and 750 degC, respectively...
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...
The combination of high frequency, high power, high efficiency capabilities is a feature of vacuum tube technology. For most of applications, large bandwidths are required, and therefore the modulation method should also allow large bandwidth operation. Optically modulated cold cathodes, avoiding the use of resonant cavities, should satisfy this requirement. This is the reason why we have developed...
We demonstrate a novel MEMS technique for fabrication of a well-aligned individual carbon nanotube field emission gun for high-resolution electron beam applications.
The process of formation of cold cathodes on the basis of carbon nanotubes synthesized in porous anodic alumina has been developed. Integral and local field emission (FE) measurements of produced cathodes have been performed. Main FE parameters: onset field, field enhancement factor and current capability of certain emitters have been measured.
A design study of a 0.1-THz coupled-cavity backward-wave oscillator (CCBWO) is presented using a finite element method and a particle-in-cell simulation. In experiments, the Si-based technology of 2-step deep reactive ion etching (DRIE) and eutectic bonding shows a good potential for the microfabrication of the interaction circuit. A miniaturized field emission cathode using carbon nanotubes grown...
We demonstrate a fully integrated, on-chip, vacuum microtriode capable of handling voltages up to 800 V. The ability to operate at such high voltages is achieved by the addition of a 10 mum-thick silicon dioxide layer to the device. The device is fabricated using MEMS fabrication principles and utilizes carbon nanotubes as field emitters. A dc amplification factor of 600 was obtained. To the best...
A new field emission pressure sensor based on carbon nanotubes (CNTs) emitting array is described in this paper. The pressure sensor is based on the principle that the field emission current is correlated with the electrical field intensity, i.e. the variable anode-emitter distance caused by pressure changes when the applied voltage is fixed. The sensor consists of two main parts, silicon etched membrane...
Carbon Nanotube (CNT) is an excellent field emission source, and is widely explored in applications like sensors, AFM probes, cathodes for Carbon Nanotube Field Emission Display (CNT-FED), and cathodes for microwave device. The requirements on field emission characteristics for these applications vary, but it is often necessary to attach CNT onto a metal electrode surface. When CNT is grown directly...
This paper presents micro-patterned carbon nanotube field emission arrays cathodes with an emitting unit area only 1mum in diameter. The fabrication process began with the deposition of a buffer layer of titanium-nitride on the silicon n type(100) substrate. Then a photo-resist overlay was patterned by conventional lithography technique to form 1mum circular aperture arrays, followed by depositing...
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