Field Electron Emission

We made an attempt to form a high quality epitaxial zinc oxide, diamond-like-carbon and graphene oxide composite thin-film on device
substrate p-Si(1 0 0) using third-harmonic (Nd:YAG Ultraviolet) laser at single footstep. Pulsed laser deposition (PLD) technique using 366 nm
(energy
150 mJ), vacuum 106 mbar has been used to grow these films in reactive gas oxygen with argon (O2|Ar) ambiance. Synthesized thin-
films were investigated systematically by fingerprint technique of confocal micro-Raman and field emission studies. As synthesized pure ZnO, nanocomposite thin films like DLC/ZnO and GO/ZnO shows the enhanced field emission (F-E) performances in this present study.

The electronic structure of the surface layer of artifi cial carbon-based materials operated as fi eld emission cathodes was studied using x-ray photoelectron spectroscopy. Samples B-1300, B-1500, and B-1900 were investigated. An analysis of the spectra showed an alteration of the hybridization of atoms in the original material, which suggested the formation of diamond-like inclusions on the sample surface.

Here we report on a straightforward and rapid means of enhancing the field electron emission performance of nascent vertically aligned multi-walled carbon nanotubes by introducing a polar zwitterionic conjugated polyelectrolyte adlayer at the vacuum–emitter interface.

Optical-field driven electron tunneling in nanojunctions has made demonstrable progress toward the development of ultrafast charge transport devices at subfemtosecond time scales, and have evidenced great potential as a springboard technology for the next generation of on-chip "lightwave electronics." Here, the empirical findings on photocurrent the high nonlinearity in metal-insulator-metal (MIM) nanojunctions driven by ultrafast optical pulses in the strong optical-field regime are reported. In the present MIM device, a 14th power-law scaling is identified, never achieved before in any known solid-state device. This work lays important technological foundations for the development of a new generation of ultracompact and ultrafast electronics devices that operate with suboptical-cycle response times.

Articles you may be interested in Effect of oxygen plasma on field emission characteristics of single-wall carbon nanotubes grown by plasma enhanced chemical vapour deposition system J. Appl. Phys. 115, 084308 (2014); 10.1063/1.4866995 Effects of carbon nanotube diameters of the screen printed cathode on the field emission characteristics J. Vac. Sci. Technol. B 28, C2C41 (2010); 10.1116/1.3289316 Carbon nanotube tip melting with vacuum breakdown in cold cathode Direct growth of single-walled carbon nanotubes on conducting ZnO films and its field emission properties The field emission (FE) properties of carbon nanotube (CNT)-based cathodes have been investigated on nanostructured surfaces grown by plasma enhanced chemical vapor deposition. The FE angular properties and temporal stability of the emergent electron beam have been determined using a dedicated apparatus for cathodes of various architectures and geometries, characterized by scanning electron microscopy and I–V measurements. The angular electron beam divergence and time instability at the extraction stage, which are crucial parameters in order to obtain high brilliance of FE-based-cathode electron sources, have been measured for electrons emitted by several regular architectures of vertically aligned arrays and critically compared to conventional disordered cathodes. The measured divergences strongly depend on the grid mesh. For regular arrays of individual CNT, divergences from 2 to 5 have been obtained; in this specific case, measurements together with ray-tracing simulations suggest that the maximum emission angle is of the order of 630 about the tube main axis. Larger divergences have been measured for electron beams emitted from honeycomb-structured cathodes (6) and significantly broader angle distributions (10) from disordered CNT surfaces. Emission current instabilities of the order of 1% for temporal stability studies conducted across a medium time scale (hours) have been noted for all cathodes consisting of a high number (10 4 and larger) of aligned CNTs, with the degree of stability being largely independent of the architecture. Published by AIP Publishing. [http://dx.doi.org/10.1063/1.4965860]

This paper reports on a simple approach for fabricating modest aspect ratio field emission arrays (FEAs) directly from bulk molybdenum substrates via the use of fluorine inductive-coupled-plasma (ICP) etching. Compared to traditional Spindt array fabrication, through our outlined fabrication process all thin film interfaces have been eliminated reducing tip delamination during operation. The as-fabricated devices exhibited low turn-on electric fields (I = 100nA) of 1.21 V/μm. Arrays of more than 10 6 tips, with controlled inter-tip-pitches of 10 μm, have produced maximum currents of up to 140 μA (5.48 V/μm). Spatially uniform emission, that can be white light optically modulated, has been observed making our Mo-FEAs promising for use in long-term, high beam current continuous emission applications.

The electronic structure of the surface layer of artifi  cial carbon-based materials operated as fi  eld emission cathodes
was studied using x-ray photoelectron spectroscopy. Samples B-1300, B-1500, and B-1900 were investigated. An
analysis of the spectra showed an alteration of the hybridization of atoms in the original material, which suggested
the formation of diamond-like inclusions on the sample surface.

Secondary carbon nanotubes (CNTs) were grown on primary ones by simply changing the methane concentration. No additional catalyst was used throughout the whole deposition process. The CNT growth was carried out using hot filament chemical vapor deposition in a gas mixture ...

In field electron emission (FE) studies, it is important to check and analyze the quality and validity of results experimentally obtained from samples, using suitably plotted current-voltage [I m (V m)] measurements. For the traditional plotting method, the Fowler-Nordheim (FN) plot, there exists a so-called "orthodoxy test" that can be applied to the FN plot, in order to check whether or not the FE device/system generating the results is "ideal". If it is not ideal, then emitter characterization parameters deduced from the FN plot are likely to be spurious. A new form of FE I m (V m) data plot, the so-called "Murphy-Good (MG) plot", has recently been introduced (R.G. Forbes, Roy. Soc. Open Sci. 6 (2019) 190912). This aims to improve the precision with which characterization-parameter values (particularly values of formal emission area) can be extracted from FE I m (V m) data. The present paper compares this new plotting form with the older FN and Milli...

Here, we investigate, through parametrically optimized macroscale simulations, the field electron emission from arrays of carbon nanotube (CNT)-coated Spindts towards the development of an emerging class of novel vacuum electron devices. The present study builds on empirical data gleaned from our recent experimental findings on the room temperature electron emission from large area CNT electron sources. We determine the field emission current of the present microstructures directly using particle in cell (PIC) software and present a new CNT cold cathode array variant which has been geometrically optimized to provide maximal emission current density, with current densities of up to 11.5 A/cm 2 at low operational electric fields of 5.0 V/µm.

—Suppression of the hysteretic electron emission in one-dimensional nanomaterial-based electron sources remains a critical barrier preventing their wide scale adoption in various vacuum electronics applications. Here, we report on the suppressed hysteretic performance, and its photo-dependence from conformal poly-vinylpyrrolidone encapsulated percolative Ag nanowire-based electron sources.

— Multi-beam modulation in a carbon nan-otube (CNT) cold cathode electron gun is herein investigated in order to develop miniaturized and fully integrated vacuum electron devices. By exposing the electron source to a millimeter-wave signal, the steady-state field emission current density is efficiently modulated by the incident high-frequency (HF) electric field. Our simulation results of this multibeam electron gun show that the field emission current density can be efficiently modulated by different incident frequency millimeter waves. We find that the modulation depth is increased by enhancing the HF input power and anode operation voltage. The modulation frequency and phase of each electron beam can be controlled using a single millimeter-wave source and by simply adjusting the lateral distance between adjacent CNT cold cathodes.

The relationship between the electron field emission properties and structure of ultra-nanocrystallinediamond (UNCD) films implanted by nitrogen ions or carbon ions was investigated. The electron field emission properties of nitrogen-implanted UNCD films and carbon-implanted UNCD films were pronouncedly
improved with respect to those of as-grown UNCD films, that is, the turn-on field decreased from 23.2 V/μm to 12.5 V/μm and the electron field emission current density increased from 10E−5 mA/cm2 to 1×10E−2 mA/cm2. The formation of a graphitic phase in the nitrogen-implanted UNCD films was demonstrated by Raman microscopy and cross-sectional high-resolution transmission electron microscopy. The possible mechanismis
presumed to be that the nitrogen ion irradiation induces the structure modification (converting sp3-bondedcarbons into sp2-bonded ones) in UNCD films.

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