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Nanocrystalline RuO2 doped SnO2 thin film has been synthesized by thermal evaporation on tungsten tip. The surface morphology of the as deposited thin film on tungsten tip has been characterized by SEM. The SEM studies reveal the complete required to draw an emission current of 1nA was observed to be 2 kV. An emission current density of the order of 8.9 A/cm2 has been obtained at an applied voltage...
Boron doped diamond films were synthesized using microwave plasma chemical vapor deposition (MPCVD) technique. The films were characterized using field emission scanning electron microscopy and Raman spectroscopy. The B2O3 concentration is varied from 1000 to 5000 ppm. With increase in B2O3 concentration particle size decreases, for 5000 ppm it is found to be 30 nm. The turn on field required to draw...
Field emission current noise analysis of carbon based materials such as multiwalled carbon nanotubes, undoped graphene, nitrogen doped graphene, boron doped graphene, and polyaniline nanotubes is carried out at base pressure of ∼1× 10−8 mbar. All the field emitters exhibited ‘step’ and ‘spike’ like fluctuations in the field emission current. The power spectra revealed that the noise is 1/fα type,...
Copper micro-cones are formed by using Ar ion beam bombardment of copper substrate using oxide masking. Threshold field of about 15.6 MV/m was obtained from samples prepared with 1hr bombardment. Maximum current density of 51 mA/cm2 was obtained under the electric field of 19.6 MV/m.
In this communication, synthesis of high quality and length controlled Te nanowire arrays directly grown on silicon substrate with and without the coating of seed layer by a facile hydrothermal method was reported. The most preferential orientation of tellurium NW's was found along [001] through micro structural investigation. Field emission properties of as grown and annealed under Ar: H2 reduction...
High quality sodium vanadate (P-Na0.33V2O5) nanowires were grown directly on conducting silicon substrates by a facile chemical solution deposition method without employing catalyst, surfactant or carrier gas. The β-Na0.33V2O5 nanowires have typical average diameter of about 120 nm and length over 7 μm. The growth mechanism for β-Na0.33V2O5 nanowires are also proposed in detail. The electrical conductivity...
Excellent electron-field emission properties of carbon nanotubes (CNTs) attract essential scientific and practical interests. The small gap between top of the emitter and the anode essentially increases the field enhancement factor. The screening effect reduces the field emission current of a CNT placed in an array of CNTs. We have derived explicit analytical expression of the field enhancement factor...
We have fabricated a test chip with various hexagonal arrays of B-doped Si tips (height ∼ 3 μm, apex radius < 30 nm, number 1–4447, resistivity 4 Ωcm, 100 orientation) in triangular arrangement (pitch 10 μm, density 1.16×106 cm−2) in order to systematically investigate the field emission current scaling with the number N of tips. Regulated voltage scans for 1 nA revealed rather efficient emission...
Vertically aligned graphene sheets were grown on carbon nanotubes by microwave-plasma enhanced chemical vapor deposition. Due to their high multistage enhancement and intrinsic low contact resistance, these graphene sheets resulted in good emission property. It was found that the turn-on field was 1.4V/μm, and the threshold-field corresponding to emission current density of 1mA/cm2 was about 2.9V/μm...
Early breast cancer detection is an emerging field of research as it can save the women infected by malignant tumors. Microwave imaging has recently been proposed for detecting small malignant breast tumors at early stages. Microwave imaging for medical application has been of interest for many years, recently it proposed for detecting small malignant breast tumors. Microwave images are maps of the...
The electron field emission properties from a photoelectrochemically etched AlGaN/GaN heterostructure grown by MOCVD was investigated. Reproducible peaks were obtained in the field emission characteristics. The origin of these peaks was explained by the proposed model of resonant tunneling of electrons. The widths of the wells and barriers have been estimated by simulating the spectra of the energy...
Well-aligned carbon nanotubes (CNTs) arrays were synthesized on series of fibers with different diameters to serve as field-emission cathode. Because the CNTs emitters reach out from the fiber curved surface, the distance between emitters varies with the diameter of the fiber. With the fiber diameter decreasing, the field emission enhancement of CNTs array increased because the screen effect decreased...
In this study, we fabricated carbon nanotube (CNT) cathode using a hybrid molding technology. A relationship between the field enhancement factor of CNT and field emission characteristics was investigated as a function of protrusion length of CNT emitter outside of the surface. The experimental results of this study were also compared with theoretical values for the CNT cathodes. The emission properties...
An electron beam with an energy as low as 5 eV and a current of 0.1 mA was produced by an electron source with a 10,000-tip silicon-based field emitter array (Si-FEA). In order to decelerate the electrons, we have designed an electrostatic lens system for the divergent beam extracted from the FEA. Spatial distribution of the electrons was investigated by a fluorescent screen with a multiple channel...
A field emitter (FE) capable of focusing an electron beam is an attractive device for application, such as ultrafine imaging devices, a scanning electron microscope and electron beam lithography. We have developed multi-gated field emitters such as a quadruple-gated FE with a three-stacked electrode lens and a quintuple-gated FE with a four-stacked electrode lens. Both the FEs can focus the electron...
Stable vacuum electronic devices have been fabricated by the Transfer Mold fabrication method to realize electric propulsion engines in harsh environments such as strong radical atmospheres in space for aerospace and environment-hard applications. The Transfer Mold field emitter arrays (FEAs) are extremely sharpened to 6.8 nm of tip radii and extremely uniform. The turn-on fields of low work function...
A tiny X-ray source for medical application is under development to realize localized irradiation of X-rays with reduction in radiation dose during inspection and operation. Pyroelectric effect in a single crystal was controlled by laser light, giving rise to high voltage generation and electron emission without additional power supplies. X-rays were generated in a counter electrode close to the crystal...
Fully-sealed 46-inch diagonal backlights using printed carbon nanotube field emitters have been developed. The impulse driving together with local dimming in the area as small as 1 cm2 lead to 4 ms moving picture response time with a frame rate 120 Hz and high contrast ratio over 1 000 000:1 in the LCD TV. The technical issues including device architecture and emitter performance are discussed here...
We present field emission properties of CNT line emitters fabricated by a unique method. Two dimensional electron beam sheet was achieved by the line emitters. The CNT line emitters exhibited high emission current density over 10.7 A/cm2 at the electric field of 2.8 V/μm and excellent emission stability during 24 hr. Moreover, emission pattern showed a very low spreading angle of emitted electrons...
Ultrananocrystalline diamond (UNCD) films developed and patented at Argonne National Laboratory (ANL) exhibit a unique combination of outstanding mechanical, tribological, electrical, thermal, biological and electron field emission properties, which already resulted in industrial components and devices currently commercialized by Advanced Diamond Technologies, a company co-founded by ANL scientists...
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