A novel low-voltage ballistic-electron-emission source
0
Citation
5
Reference
10
Related Paper
Abstract:
A novel tunnel junction emitter based on ballistic electron transmission through ultra-thin metal foils is proposed as an electron source. From a simple planar tunneling model and Monte-Carlo simulations, we show that either a high-brightness monochromatic electron source can be obtained or a high-current source with energy spread comparable with a field emission source. Freestanding 5 nm thick Pt films were successfully fabricated for the construction of a tunnel junction electron source, in which a UHV-STM is used as a tip-emitter positioning device.Keywords:
Electron gun
Microfabricated field emitters have shown the potential for very high current densities (>100A∕cm2) and total emission currents (>1A). However, realizing this potential has been elusive, primarily because these cathodes exhibit insufficient emission uniformity over an emitter array. In this article we report the development of an in situ processing method based on emitter tip self-heating during operation that is shown to improve emission uniformity between emitter tips. Two tips differing in emission current by three orders of magnitude for a given voltage as fabricated are shown to be essentially identical in their emission characteristics after controlled pulsing to very high emission current. When the method was applied to a 50 000 tip array, it produced 300 mA of emission (40A∕cm2). The experimental arrangement prevented advancing to higher emission levels due to space charge limitations. It is expected that 1 A of emission at ∼100A∕cm2 is possible with appropriate modifications to the experimental apparatus.
Field emitter array
Field emission display
Cite
Citations (60)
Field emission and field desorption microscopies revealed that emitter shape formed at high current of field emission differed from one obtained by heating in a field at a positive tip voltage. The influence of space charge of emitted electrons on field emitter shape changes is considered.
Cite
Citations (0)
Field emission from ZrC films deposited on Si and Mo single emitters and field emitter arrays (FEAs) has been studied. For single emitters, the results show dramatic improvements in emitter performance by reducing work functions—on the order of 1 eV—and increasing stability. For FEAs, deposition of a ZrC film reduced the operating voltage 30%–50% at an emission current of 1.0 μA/tip and increased the emission stability.
Deposition
Cite
Citations (48)
Cite
Citations (0)
The manufacture method and development of the field emitter array (FEA) are presented in this paper.The possibility of the field emitter arrays as the electron sources in traveling wave tubes is discussed.The electron gun design with FEAs is also introduced.
Electron gun
Field emitter array
Traveling-wave tube
Cite
Citations (0)
We fabricated the point emitter using a tip-treated carbon nanotube (CNT) fiber. The CNT point emitter showed the high emission current and good emission stability. It is considered that the excellent field emission properties are attributed to a large field enhancement factor caused by a large aspect ratio of the sharp tip of the point emitter and the tight binding of CNTs.
Field emission display
Cite
Citations (0)
Recent progress on aberration correction optics and single atom spectroscopy techniques increase needs of higher brightness electron sources than conventional single crystalline tungsten emitters. For this purpose, we are trying to fabricate a self-aligned nano-structured electron emitter using a field emission induced growth (FEIG) method in a field emission microscope (FEM) apparatus. The growth process can be monitored by the FEM, so that it is possible to control the nano-emitter size. A fabricated nano-emitter was mounted on a commercially available field-emission scanning electron microscope (FE-SEM) and its practicality was investigated. As compared with a carbon nanotube (CNT) emitter, the nano-emitter achieves larger beam current (better image contrast) and shows higher vibration durability. Emission stability of the nano-emitter is also within practical level, so that it was demonstrated that the FEIG nano-emitter could be a leading candidate for substituting conventional field emitters. [DOI: 10.1380/ejssnt.2014.192]
Field emission microscopy
Field emitter array
Field emission display
Cite
Citations (1)
Abstract In this work, a novel nanogap with inclined protrusion cathode in palladium strip fabricated by hydrogen absorption under high pressure treatment is optimized for the surface conduction electron emitter. The results of our previous study had shown that the field emission property of the tested structure is superior to conventional one with a coplanar cathode. for a specified emitter material, the surface conduction electron‐emitters (SCE) are further investigated by varying the thickness, tilted angle and gap of palladium (Pd). An optimal field emission efficiency with 80° tilted angle, 120 nm gap and 10 nm thickness of Pd is found for certain designed field emission efficiency. We further find that varying the emitter material work function of the emitter material from 5.12 eV to 3.9 eV will further improve the field emission property due to the increase of the emitted current.
Cite
Citations (0)
In the present work, we report our finding of ultra-high emission current from a single CNT emitter. This work enhances the understanding of the field emission characteristics of CNT emitters and its potential application as ultra-bright electron source.
Cite
Citations (0)
This contribution is a result of higher emission current investigations with CNT field-emitter cathodes. The emitter resistor must be considered for emission current above 5 mA. Thin and long CNT field-emitters show emission current saturation. A simple R-limited emission model is presented.
Cold cathode
Saturation current
Saturation (graph theory)
Cite
Citations (2)