High Performance Field Emitters

Collins, Clare M.; Parmee, Richard; Milne, W. I.; Cole, Matthew T.

doi:10.1002/advs.201500318

Cited by 45 publications

(29 citation statements)

References 164 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, in this case, the EF strength decreases at the nanotubes tips because their screening by neighboring closely located CNTs should be taken into account. In a number of researches, dependence of the CNT emission current on amplification factor of the EF strength at their tips β = E max /E 0 was studied [3][4][5][6]. However, the data of various authors on the quantitative dependences of the CNTs characteristics on their parameters do not always coincide [20].…”

Section: Calculation Of Degree Of the Ef Strength Amplification At Thmentioning

confidence: 99%

“…Another area of such problems' application is the emission devices using arrays of carbon nanotubes (CNTs) [3][4][5]. According to [6], the problem of determination of the EF strength amplification at the tips of the CNT array: β = E max /E 0 (where E max is maximum EF strength at the rods tips, and E 0 is the average applied EF strength), depending on their parameters, is not completely solved despite that it has been considered in many researches.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Modelling of Electric Field Strength Amplification at the Tips of Thin Conductive Rods Arrays

Rezinkina¹

2020

PIER M

View full text Add to dashboard Cite

Degree of the electric field (EF) amplification at the tips of thin and long conductive rods array has been calculated. It is shown that such amplification depends on the rods height (H) and radius (R), as well as on the distance between separate rods in the array. For simulation, an approach to numerical calculation of the EF near conductive rods with a large ratio of height to radius: H/R > 10 2-10 4 has been proposed. Rods with such parameters may represent carbon nanotubes, channels of breakdowns in insulation, lightning leader channels, lightning rods, etc. The proposed approach is based on the finite integration technique. It also uses the analytical law of decrease of the EF strength and potential of a conductive ellipsoid under potential in the directions perpendicular to the ellipsoid axis and above its tip. As a result, numerical calculations of the EF distribution in systems with such rods were carried out applying calculation grids with steps proportional to the rods length, not their diameters. It permits substantial decrease of the required computational resources such as memory and time.

show abstract

Section: Calculation Of Degree Of the Ef Strength Amplification At Thmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Modelling of Electric Field Strength Amplification at the Tips of Thin Conductive Rods Arrays

Rezinkina¹

2020

PIER M

View full text Add to dashboard Cite

show abstract

“…Field-emission (FE) cold cathodes are an outstanding candidate for the replacement of incumbent thermionic electron sources in THz VEDs. FE sources readily overcome many of the inherent limitations associated with traditional thermionic devices, including their slow temporal response and high temperature operation [11][12][13][14]. Meanwhile, the gap between the emitter and the HF system will be dramatically shortened in a cold cathode electron optical system, thereby relaxing design difficulties associated with the need for precise alignment of the beam.…”

Section: Introductionmentioning

confidence: 99%

Design and Simulation of a Multi-Sheet Beam Terahertz Radiation Source Based on Carbon-Nanotube Cold Cathode

Yuan

et al. 2019

Nanomaterials

Self Cite

View full text Add to dashboard Cite

Carbon nanotube (CNT) cold cathodes are proving to be compelling candidates for miniaturized terahertz (THz) vacuum electronic devices (VEDs) owning to their superior field-emission (FE) characteristics. Here, we report on the development of a multi-sheet beam CNT cold cathode electron optical system with concurrently high beam current and high current density. The microscopic FE characteristics of the CNT film emitter is captured through the development of an empirically derived macroscopic simulation model which is used to provide representative emission performance. Through parametrically optimized macroscale simulations, a five-sheet-beam triode electron gun has been designed, and has been shown to emit up to 95 mA at 3.2 kV. Through careful engineering of the electron gun geometric parameters, a low-voltage compact THz radiation source operating in high-order TM 5 , 1 mode is investigated to improve output power and suppress mode competition. Particle in cell (PIC) simulations show the average output power is 33 W at 0.1 THz, and the beam–wave interaction efficiency is approximately 10%.

show abstract

“…[14][15][16][17][18][19] As a static electron emission source, CNTs have been shown to outperform metal tips across almost all quantifiable metrics. [20] In this work, for the first time, we demonstrate an ultrafast carbon nanotube-based, subnanometer electron source. The extremely sharp tips, coupled to their structural stability allow for extremely high optical field localization, thereby enabling access to the field-driven photoemission regime at unprecedentedly short wavelengths as low as 410 nm, compared to 800-3000 nm as conventionally used for metallic tips.…”

mentioning

confidence: 95%

Carbon Nanotubes as an Ultrafast Emitter with a Narrow Energy Spread at Optical Frequency

Zhou

Zhai

et al. 2017

Advanced Materials

View full text Add to dashboard Cite

Ultrafast electron pulses, combined with laser-pump and electron-probe technologies, allow ultrafast dynamics to be characterized in materials. However, the pursuit of simultaneous ultimate spatial and temporal resolution of microscopy and spectroscopy is largely subdued by the low monochromaticity of the electron pulses and their poor phase synchronization to the optical excitation pulses. Field-driven photoemission from metal tips provides high light-phase synchronization, but suffers large electron energy spreads (3-100 eV) as driven by a long wavelength laser (>800 nm). Here, ultrafast electron emission from carbon nanotubes (≈1 nm radius) excited by a 410 nm femtosecond laser is realized in the field-driven regime. In addition, the emitted electrons have great monochromaticity with energy spread as low as 0.25 eV. This great performance benefits from the extraordinarily high field enhancement and great stability of carbon nanotubes, superior to metal tips. The new nanotube-based ultrafast electron source opens exciting prospects for extending current characterization to sub-femtosecond temporal resolution as well as sub-nanometer spatial resolution.

show abstract

High Performance Field Emitters

Cited by 45 publications

References 164 publications

Modelling of Electric Field Strength Amplification at the Tips of Thin Conductive Rods Arrays

Modelling of Electric Field Strength Amplification at the Tips of Thin Conductive Rods Arrays

Design and Simulation of a Multi-Sheet Beam Terahertz Radiation Source Based on Carbon-Nanotube Cold Cathode

Carbon Nanotubes as an Ultrafast Emitter with a Narrow Energy Spread at Optical Frequency

Contact Info

Product

Resources

About