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# 25th International Vacuum Nanoelectronics Conference

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Displaying Results 1 - 25 of 167
• ### Field emission current noise analysis of carbon based materials

Publication Year: 2012, Page(s):1 - 2
Cited by:  Papers (1)
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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 no... View full abstract»

• ### Electron emission from LiTaO3 crystal excited by Nd:YLF laser light and its X-ray source application

Publication Year: 2012, Page(s):1 - 2
Cited by:  Papers (1)
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Electron emission current from LiTaO3 excited by Nd:YLF laser light and X-ray from a counter electrode were measured. X-ray was observed to keep the constant intensity by shortening a time interval between irradiation. Dependence of the electron emission pattern and the spot size on the distance between the crystal and the screen was measured. The electron beam was found to be focused a... View full abstract»

• ### Photo-modulated field emission of carbon nanotubes cold cathodes

Publication Year: 2012, Page(s):1 - 4
Cited by:  Papers (1)
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In this article, we present our work on vertically aligned multi-walled carbon nanotube arrays for field emission cathodes and photocathodes. Carbon nanotubes cathodes deliver current densities up to 0.5A/cm2. To optically modulate the emission, silicon photodiodes have been integrated under the carbon nanotubes, allowing a laser-controlled emission. An ON/OFF ratio up to 23 has been ac... View full abstract»

• ### ZnO nanowires lateral field emission devices: Control on nanowire orientation and electron emission performance

Publication Year: 2012, Page(s):1 - 2
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ZnO nanowires (NWs) lateral field emission devices were fabricated. The NW-clusters were controlled to locally grow on the edges of the electrodes with different spread-angles. Devices with NWs in 0°~57° tilt-angles possess better field emission property. Typically, the device can operate at a bias of 477 V (anode-cathode gap: 50 μm) with emission current of 9.3 μA (cur... View full abstract»

• ### Influence of beam uniformity on the transverse emittance of gated field emitter arrays

Publication Year: 2012, Page(s):1 - 2
Cited by:  Papers (2)
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Transverse emittance of field emission beam generated from single-gate FEAs are experimentally studied. Although as fabricated FEAs exhibit highly granular beam, by applying the Ne-gas conditioning method, uniform FEA beam was realized and its emittance was measured and compared with the previously measured emittance values for granular beams. View full abstract»

• ### Carrier multiplication in a photodetector driven by diamond cold cathode

Publication Year: 2012, Page(s):1 - 2
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In this study, key conditions of a carrier multiplication in amorphous selenium (a-Se) films were discussed in order to increase a sensitivity of vacuum tube photodetectors. The structural and electronic properties were analyzed for a-Se films with different structure and composition. This study will open up the possibility of developing new photodetectors, such as low-dose x-ray diagnosis systems... View full abstract»

• ### Field-emission X-ray sources with an anisotropic focusing lens for isotropic X-ray focal spots

Publication Year: 2012, Page(s):1 - 2
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Hermetic-sealed field-emission X-ray sources with an anode voltage and current of 70 kV and 0.5 mA have been developed using an anisotropic focusing electron lens structure for an isotropic focal spot. The anisotropic focusing of an electron beam was achieved using an electrostatic electron lens with anisotropic aperture geometry integrated in a gate (or grid) electrode. The anisotropic geometry h... View full abstract»

• ### Near Field-Emission SEM: Primary electron beam generation and comparison with STM

Publication Year: 2012, Page(s):1 - 2
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In Near Field-Emission Scanning Electron Microscopy the source of the primary beam is only few tens nm away from the target. We report the progress in primary beam generation and compare the performance of the instrument in field emission mode with respect to the well-established Scanning Tunneling Microscopy (STM). View full abstract»

• ### CNT photocathodes based on GaAs high-frequency photoswitches

Publication Year: 2012, Page(s):1 - 2
Cited by:  Papers (1)
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A high-frequency photocathode based on carbon nanotube (CNT) blocks on semiisolating GaAs or low-temperature grown GaAs was fabricated and used for electron emission in a diode configuration. The CNT blocks can achieve high currents and current densities of I=0.5 mA and J=28 mA/cm2 at E=2.1 V/μm, respectively. The photomodulation was achieved with a GaAs photoswitch electrically ... View full abstract»

• ### The electron optics properties of micro-column with field emitter

Publication Year: 2012, Page(s):1 - 2
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We successfully demonstrated the electron optics properties of newly designed micro-column in this report. The micro-column consisted of an electron gun and objective lens. The electron gun was structured with FEA and condenser lens. The each structure was optimized in order to perform each abilities and not to disturb other's function. It was confirmed that the diameter of focused beam was around... View full abstract»

• ### Study of the working performance of WO2 nanowire arrays in gated field emission display devices

Publication Year: 2012, Page(s):1 - 2
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Tungsten oxide nanowires are integrated into gated wing-type field emission display (FED) devices, which are synthesized at low temperature of 550 °C by catalyzed-growth CVD way. The emission behaviors of the device are testified by transparent anode way to investigate their future application. These WO2 FED devices are found to have a turn-on field of 5.76 V/μm and their ... View full abstract»

• ### Extremely low threshold of field emission from graphene nanoclusters

Publication Year: 2012, Page(s):1 - 2
Cited by:  Papers (1)
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Carbon nano-cluster cathodes exhibit a low threshold electron emission, which is 2-3 orders lower than on metals and semiconductors. We confirm the effect by direct experiments with graphene structures. We are suggesting the model based on interference electrons wave function in 2D-space charge region of carbon and Tamm's surface states of dangling bonds. This barrier is transparent for electrons ... View full abstract»

• ### Electron field emission from cathodes with Si and SiGe nanoclusters

Publication Year: 2012, Page(s):1 - 2
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The peculiarities of electron field emission from Si cathodes with Si and SiGe nanoclusters have been investigated in details. To form Si nanoclusters on the flat surface or Si tips the LP CVD, IPS, or thermal evaporation methods were used for deposition of initial silicon enriched SiOx (x≤1.5) films in the thickness range 2-10 nm. In some cases the amorphous ultrathin Si film ha... View full abstract»

• ### Transparent brush-type carbon nanotube cathode

Publication Year: 2012, Page(s):1 - 4
Cited by:  Patents (1)
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Here we report brush-type carbon nanotubes (BCNT) film, which is combined with graphene and carbon nanotube (CNT) array, as cathode on transparent substrate. Prepared by pyrolysis, vertically aligned CNT (VACNT) arrays are covered by a few layer graphene sheets like thin blankets. There are both good electrical and mechanical connections between VACNT arrays and graphene sheets. Transparent field ... View full abstract»

• ### Investigation on the field emission behaviour of CNT-based emitter systems

Publication Year: 2012, Page(s):1 - 2
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We have investigated the probable origin of instable emission behaviour for various types of cold emitters based on CVD carbon layers, CNT and Al2O3/ITO glass. Of them, CNT-based cold emitters have been accepted to be most appropriate for the promising applications such as displays, flat lamps, signage boards and back-light unit (BLU) including local dimming function. Althoug... View full abstract»

• ### Development of planar X-ray source using gated CNT emitter

Publication Year: 2012, Page(s):1 - 2
Cited by:  Papers (1)
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A planar X-ray source using gated CNT (Carbon nanotube) emitters has been developed. Clear X-ray transmission images were taken with its applied X-ray source. In the diode structure measurement, the turn-on electric field of the CNT emitter was about 1.2 V/μm. In the triode structure measurement, characteristic X-ray peaks of Cu and the Bremsstrahlung were observed. The maximum energies of ... View full abstract»

• ### Improved field emission of CNTs on heated substrate for medical x-ray imaging application

Publication Year: 2012, Page(s):1 - 2
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For the next generation x-ray imaging system, small focal spot combined with fast switching electron emitter is desired to obtain high resolution images and minimize motion-induced blurring of images of moving organs such as the heart. Carbon nanotubes (CNTs) have the potential to be excellent emitters for novel x-ray imaging applications that overcome the limitations imposed by conventional therm... View full abstract»

• ### Field emission characteristics of graphene film on nickel substrate

Publication Year: 2012, Page(s):1 - 2
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Graphene film on nickel substrate is synthesized by using thermal chemical vapor deposition method. The field emission characteristics of the graphene film are measured. The turn-on field of 6.4 V/μm and the emission current as large as 1.5 mA is achieved. The current stability of graphene film is very good with fluctuation less than 2.4%. The emission site is found from the protrusion of t... View full abstract»

• ### CNT X-ray source array for detection and treatment of cancer

Publication Year: 2012, Page(s):1 - 2
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We recently developed a new spatially distributed x-ray source array technology utilizing the carbon nanotubes (CNTs) as the electron field emitters. The technology with flexible source configuration and digital control of radiation opens up new possibilities for designing x-ray tomography scanners with enhanced resolution and scanning speed, and for developing novel radiotherapy systems. Several ... View full abstract»

• ### Development of fully vacuum-sealed X-ray tubes with carbon nanotube field emitters

Publication Year: 2012, Page(s):1 - 2
Cited by:  Papers (2)
| | PDF (45 KB) | HTML

Summary form only given. We, for the first time, developed fully vacuum-sealed X-ray tubes with carbon nanotube field emitters. The specially designed brazing process has been adopted for the vacuum sealing of the X-ray tube. The fabricated two types of X-ray tubes showed a good operation with a high stability and long lifetime. View full abstract»

• ### Recent progress in reshaping the theory of orthodox field electron emission

Publication Year: 2012, Page(s):1 - 2
Cited by:  Papers (2)
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As part of a continuing attempt to build a more coherent scientific structure for the theory of field-assisted electron emission, and in particular for the interpretation of measured current-voltage data, this paper provides an overview of recent progress in what is proving to be a very messy and complicated task. View full abstract»

• ### Dynamic behaviour of multilayered graphene and metal-coated carbon nanotube field emitters

Publication Year: 2012, Page(s):1 - 2
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Field emission microscopy (FEM) and in-situ transmission microscopy (TEM) studies on electron emission from a piece of exfoliated multilayered graphene revealed that the structure of graphene edges changed from open before field emission (FE) measurement to closed after FE under high emission current over a few tens μA (107-108 A/cm2 in current density). Dyn... View full abstract»

• ### Carbon nanotubes grown in a field emission electron microscope

Publication Year: 2012, Page(s):1 - 2
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We have recently shown that individual single wall carbon nanotubes (CNTs) can be grown on metallic tips in a field emission microscope (FEM) on which carbon passivation layers and Ni catalysts have been pre-deposited in situ (see Fig. 1). This allows direct observation from the nucleation stage until the end of the growth [1]. In this talk I will review this unique synthesis method and our more r... View full abstract»

• ### Novel design considerations for high efficiency carbon nanotube field emitters

Publication Year: 2012, Page(s):1 - 2
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High-current field emitters with high operational stability are in demand for a number of applications, including electronic and important military use. In the present research, such a field emitter is designed through application of interface engineering and three-dimensional (3-D) design in a carbon nanotube (CNT) based field emitter. Field emission characterization of the emitter shows low turn... View full abstract»

• ### Ultrananocrystalline diamond (UNCD) films for field emission-based science and devices

Publication Year: 2012, Page(s):1 - 2
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Summary form only given. 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... View full abstract»