scholarly journals Model of Field Electron Emission from the Edge of Flat Graphene into Vacuum

2019 ◽  
Vol 10 (1) ◽  
pp. 61-68
Author(s):  
N. A. Poklonski ◽  
A. I. Siahlo ◽  
S. A. Vyrko ◽  
S. V. Ratkevich ◽  
A. T. Vlassov
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Graphene Sheet ◽  
Current Density ◽  
Electron Emission ◽  
Field Effect ◽  
Field Electron Emission ◽  
Graphene Plane ◽  
Field Electron ◽  
Electron Emitters

Graphene-based nanostructures are the promising materials for applications as electron emitters.The aim of the work is to study the field electron emission from the edge of a single graphene plane.In the semi-classical approximation, a model of field electron emission from the edge of a rectangular graphene sheet has been developed.The current density of field electron emission into vacuum from the edge of a flat graphene sheet was calculated depending on the magnitude of the pulling electric field strength.The analysis and comparison of limiting emission currents from graphene and from bulk systems have been carried out.The results of the work can be used in the development of graphene-based field effect cathodes.

scholarly journals Field Electron Emission Experiments with Cold-Sprayed Cu-SiC Composite Coatings

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 134
Author(s):  
Marcin Winnicki ◽  
Wojciech Łapa ◽  
Zbigniew Znamirowski
Keyword(s):  
Silicon Carbide ◽  
Electric Field ◽  
Composite Coating ◽  
Field Emission ◽  
Electron Emission ◽  
Steel Substrate ◽  
Composite Coatings ◽  
Field Electron Emission ◽  
Powder Morphology ◽  
Field Electron

Field electron emission of cold-sprayed copper-silicon carbide composite coating on a steel substrate was investigated. Two types of copper powders morphologies, namely dendritic and spherical, were mixed with crushed silicon carbide ceramic, and used as a feedstock. The powder mixtures were sprayed on the substrates and formed coatings with the designed surface topography—(i) flat and (ii) wavy. The microstructure of the coatings as well as the ceramic contents were analyzed. Initial tests proved that field emission from the Cu-SiC composite coatings was possible and depended mostly on the copper powder morphology. It was found out that the additional SiC layer deposited onto the composite coating significantly increased the number of electron emitters and thus improved the intensity of field emission. The Fowler–Nordheim model was used to find the threshold electric field, Eth, and coefficient of electric field amplification, β. These important properties of Cu/SiC + SiC coatings were found to be in the range of Eth = 20 to 24 V/µm and β = 340 to 410, respectively.

scholarly journals Анализ эмиссии электронов с одиночного кремниевого катода в квазивакуумную (воздушную) среду методом атомно-силовой микроскопии

2020 ◽  
Vol 90 (11) ◽  
pp. 1931
Author(s):  
И.Д. Евсиков ◽  
С.В. Митько ◽  
П.Ю. Глаголев ◽  
Н.А. Дюжев ◽  
Г.Д. Демин
Keyword(s):  
Electric Field ◽  
Electron Emission ◽  
Enhancement Factor ◽  
Strong Electric Field ◽  
Theoretical Estimate ◽  
Field Enhancement ◽  
Field Electron Emission ◽  
Field Enhancement Factor ◽  
Radius Of Curvature ◽  
Field Electron

Using atomic force microscopy (AFM), we experimentally examined the features of field-electron emission from a single point-type silicon cathode into a quasi-vacuum (air) medium. In the non-contact AFM operating mode, the current – voltage characteristics (CVCs) of a single cathode with a nanometer radius of curvature of the tip were measured at distances of 10 nm and 20 nm between the cathode tip and the top of the measuring probe. The electric field distribution was simulated both on the surface of the tip of a single cathode and on the surface of the tips of individual cathodes within the array, based on which a theoretical estimate of the field enhancement factor as a function of the cathode-probe distance was made. The field-enhancement factor calculated from the experimental CVCs in the Fowler-Nordheim coordinates is several orders of magnitude higher than its value obtained from theoretical calculations. Such a mismatch between the experimental data and the simulation results indicates the need to take into account additional quantum-size effects, which play an important role in the formation of the field-electron emission current in the nanoscale gap. In particular, deformation of the silicon emitter tip can occur at this scale due to the penetration of a strong electric field into its surface region, which, in turn, causes the distortion of the potential barrier at the interface with the quasi-vacuum medium.

scholarly journals Promising field electron emission performance of vertically aligned one dimensional (1D) brookite (β) TiO2nanorods

RSC Advances ◽  
2016 ◽  
Vol 6 (101) ◽  
pp. 98722-98729 ◽  
Author(s):  
Rupesh S. Devan ◽  
Yuan-Ron Ma ◽  
Mahendra A. More ◽  
Ruchita T. Khare ◽  
Vivek V. Antad ◽  
...  
Keyword(s):  
Current Density ◽  
Electron Emission ◽  
Field Electron Emission ◽  
One Dimensional ◽  
Emission Performance ◽  
Turn On ◽  
Emission Stability ◽  
Field Electron ◽  
Vertically Aligned ◽  
A Current

The vertically aligned and uniformly dispersed β-TiO2nanorods injected electrons direct toward emission sites, and prominently contributed to the low turn-on field of 3.9 V μm−1at a current density of 10 μA and also enhance the emission stability.

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