scholarly journals Electron Field Emission from Undoped and Doped DLC Films

1999 ◽  
Vol 558 ◽  
Author(s):  
V.G. Litovchenko ◽  
A.A. Evtukh ◽  
N.I. Klyui ◽  
YU.M. Litvin ◽  
S.Yu. Kudzinovsky ◽  
...  
Keyword(s):  
Nitrogen Content ◽  
Field Emission ◽  
Threshold Voltage ◽  
Field Enhancement ◽  
Electron Field Emission ◽  
Emission Area ◽  
Current Voltage ◽  
Wide Range ◽  
Electron Field ◽  
Effective Emission Area

ABSTRACTElectron field emission and electrical conductivity of undoped and nitrogen doped DLC films have been investigated. The films were grown by the PE CVD method from CH4:H2 and CH4:H2:N2 gas mixtures, respectively. By varying nitrogen content in the gas mixture over the range 0 to 45%, corresponding concentrations of 0 to 8 % (atomic) could be achieved in the films. Three different gas pressures were used in the deposition chamber: 0.2, 0.6 and 0.8 Torr. Emission current measurements were performed at approximately 10−6 Torr using the diode method with emitter-anode spacing set at 20 gm. The current - voltage characteristics of the Si field electron emission arrays covered with DLC films show that threshold voltage (Vth) varies in a complex manner with nitrogen content. As a function of nitrogen content, Vth initially increases rapidly, then decreases and finally increases again for the highest concentration. Corresponding Fowler-Nordheim (F-N) plots follow F-N tunneling over a wide range. The F-N plots were used for determination of the work function, threshold voltage, field enhancement factor and effective emission area. For a qualitative explanation of experimental results, we treat the DLC film as a diamond-like (sp3 bonded) matrix with graphite-like inclusions.

Effect of Diameter on Electron Field Emission of Carbon Nanotube Bundles

2005 ◽  
Vol 901 ◽  
Author(s):  
Devon McClain ◽  
Mason DeRoss ◽  
Noel Tavan ◽  
Jun Jiao ◽  
Coralee M McCarter ◽  
...  
Keyword(s):  
Field Emission ◽  
Sol Gel ◽  
Field Enhancement ◽  
Chemical Vapor ◽  
Electron Field Emission ◽  
Nanotube Bundles ◽  
Turn On ◽  
Electron Field ◽  
Aggregate Structures ◽  
Field Emission Performance

AbstractArrays of multi-walled carbon nanotunbe (CNT) bundles were fabricated on silicon [100] substrate with iron-nitrate sol-gel catalyst patterned via standard photolithographic techniques. Nanotube bundles with diameters ranging from 400µm to 15µm were grown in a chemical vapor deposition reactor and electrically characterized using a scanning-anode probe apparatus. Results showed a relatively low number of graphitic layers in individual nanotubes and a definite increase in field emission performance with decreasing bundle diameter. A 400µm wide matt of CNTs yielded a turn-on field of 6.7 V/µm and field enhancement of 602 while 15µm bundles performed significantly better with turn-on fields of 1.6 V/µm and field enhancement factors of 2425. The overall trend strongly suggests that the field emission character of CNT based aggregate structures such as those presented here is proportional to their aspect ratio.

Origins of field enhancement in electron field emission from ion beam synthesized SiC layers

2002 ◽  
Vol 81 (21) ◽  
pp. 3942-3944 ◽  
Author(s):  
W. M. Tsang ◽  
S. P. Wong ◽  
J. K. N. Lindner
Keyword(s):  
Field Emission ◽  
Ion Beam ◽  
Field Enhancement ◽  
Electron Field Emission ◽  
Electron Field

Electron Field Emission from GaN Nanotip Pyramids

2003 ◽  
Vol 798 ◽  
Author(s):  
Hock M. Ng ◽  
Jonathan Shaw ◽  
Aref Chowdhury ◽  
Nils G. Weimann
Keyword(s):  
Field Emission ◽  
Enhancement Factor ◽  
Molecular Beam ◽  
Field Enhancement ◽  
Electron Field Emission ◽  
Polar Regions ◽  
Turn On ◽  
Electron Field ◽  
Selective Chemical ◽  
20 Nm

ABSTRACTElectron field emission was measured from GaN nanotip pyramids formed by polarity-selective chemical etching in KOH solution. The GaN samples were grown by plasma-assisted molecular beam epitaxy and consisted of regions of Ga- and N-polar GaN grown at the same time. The pyramids were formed only in the N-polar regions and have extremely sharp tips with diameters estimated to be less than 20 nm. Field emission measurements showed a characteristic Fowler-Nordheim behavior. The average turn-on field was 1.6 V/μm with a corresponding normalized field enhancement factor of about 1500.

Field Emission from Carbon Systems

2000 ◽  
Vol 621 ◽  
Author(s):  
John Robertson
Keyword(s):  
Carbon Nanotubes ◽  
Grain Boundary ◽  
Field Emission ◽  
Electron Affinity ◽  
Field Enhancement ◽  
Diamond Like Carbon ◽  
Electron Field Emission ◽  
Nanostructured Carbon ◽  
Boundary States ◽  
Electron Field

ABSTRACTElectron field emission from diamond, diamond-like carbon, carbon nanotubes and nanostructured carbon is compared. It is found that in all practical cases that emission occurs from regions of positive electron affinity with a barrier of ∼5 eV and with considerable field enhancement. The field enhancement in nanotubes arises from their geometry. In diamond, the field enhancement occurs by depletion of grain boundary states. In diamond-like carbon we propose that it occurs by the presence of sp2-rich channels formed by the soft conditioning process.

High Yield Growth of Various CdS Nano-Structures and Their Electron Field Emission Behavior

2006 ◽  
Vol 963 ◽  
Author(s):  
Juno Lawrance ◽  
Timothy Gutu ◽  
Devon McClain ◽  
Jianfeng Wu ◽  
Jun Jiao
Keyword(s):  
Field Emission ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
High Yield ◽  
Vapor Flow ◽  
Electron Field Emission ◽  
Nanoscale Device ◽  
Field Emission Properties ◽  
Wide Range ◽  
Electron Field

ABSTRACTNanostructures are considered the critical component in a wide range of potential nanoscale device applications. Yet a procedure to fabricate them with both controllable results and in bulk quantities must be developed in order to achieve their commercialization at reduced cost. In this report, we introduce an improved vapor-liquid-solid method that is capable of preparing high yield, high quality CdS nanowires and nanobelts in a turf-like configuration. To increase yield, we placed gold-coated substrates in a ceramic boat partially covered with a glass slide to form a gas trap. Only a small opening was provided to allow the CdS vapor to escape from the trap. This arrangement increases catalyst exposure to CdS vapor flow in comparison to conventional CVD methods. This allowed the CdS vapor to deposit densely over the substrate at a predetermined temperature range of 501°C-630°C inside the quartz tube. These conditions results in synthesis of various morphologies on both quartz and tungsten substrates including an intertwined-like structure not previously reported. Electron microscopy and microanalysis techniques were utilized in characterizing these morphologies, internal structures and elemental compositions. Electron field emission properties were investigated in an ultra high vacuum chamber set up with a base pressure of ∼1E-9 torr.

Improvement of Electron Field Emission from Carbon Nanotubes by Ba(NO3)2 Treatment

2018 ◽  
Vol 386 ◽  
pp. 116-121
Author(s):  
Evgeny Kitsyuk ◽  
Egor Lebedev ◽  
Andrey Nartov ◽  
Roman Ryazanov ◽  
Artemiy Shamanaev
Keyword(s):  
Carbon Nanotubes ◽  
Gas Phase ◽  
Field Emission ◽  
Threshold Voltage ◽  
Chemical Deposition ◽  
Thin Layers ◽  
Electron Field Emission ◽  
Electron Field ◽  
Cnt Arrays ◽  
Emission Threshold

The method of manufacturing BaO thin layers on carbon nanotubes (CNT) from Ba(NO3)2 aqueous solutions was demonstrated. Ordered carbon nanotubes arrays were synthesized by catalytic plasma-stimulated chemical deposition from the gas phase. The influence of the BaO content on the work function and, accordingly, carbon nanotubes emission properties were investigated. Significant field emission threshold voltage of CNT arrays treated by solutions with the lowest Ba(NO3)2 concentrations was demonstrated.

scholarly journals Десять способов определения площади полевой эмиссии

2019 ◽  
Vol 89 (10) ◽  
pp. 1615
Author(s):  
Е.О. Попов ◽  
А.Г. Колосько ◽  
М.А. Чумак ◽  
С.В. Филиппов
Keyword(s):  
Field Emission ◽  
Anomalous Behavior ◽  
Emission Data ◽  
Voltage Level ◽  
Emission Area ◽  
Current Voltage ◽  
Effective Emission Area ◽  
Current Voltage Characteristics ◽  
The Relationship

A variety of types for formal determination of one of the main parameters of field emission systems - the emission area was investigated. Using hemisphere on a cylindrical post model built using the COMSOL Multiphysics software package the relationship between known types of emission area estimation was shown. The corresponding values of emission currents were calculated. It was shown that the formal emission area (the ratio of the total current to the current density at the top) provides only ~ 75% of the emission current value. The effect of the anomalous behavior of the effective emission area (intercept of the trend line of current-voltage characteristics) is obtained when the voltage level changes in standard Fowler-Nordheim coordinates. A method for an experimental estimate of the field emission area using the modified Fowler-Nordheim coordinates ln (I/U^(2-η/6)) vs 1/U is proposed. The method is applied to the analysis of field emission data of a multi-tip nanocomposite emitter with carbon nanotubes.

Field Enhancement Mechanisms and Electron Field Emission Properties of Ion Beam Synthesized and Modified SiC/Si Heterostructures

2002 ◽  
Vol 742 ◽  
Author(s):  
W. M. Tsang ◽  
S. P. Wong ◽  
J. K. N. Lindner
Keyword(s):  
Field Emission ◽  
Ion Beam ◽  
Field Enhancement ◽  
Ion Source ◽  
High Dose ◽  
Electron Field Emission ◽  
Emission Properties ◽  
Field Emission Properties ◽  
Electron Field ◽  
Electron Field Emission Properties

ABSTRACTSiC/Si heterostructures were synthesized by high dose carbon implantation into silicon using a metal vapor vacuum arc ion source. Their electron field emission properties were studied and correlated with results from other characterization techniques including atomic force microscopy (AFM), conducting AFM, Fourier transform infrared absorption spectroscopy, x-ray diffraction and photoelectron spectroscopy. It is clearly demonstrated that there are two types of field enhancement mechanisms responsible for the improvement of the electron field emission properties of these ion beam synthesized SiC/Si heterostructures, namely, the surface morphology effect and the local electrical inhomogeneity effect. The dependence of the FE properties on the carbon implant dose and thermal annealing conditions could be understood in terms of these two field enhancement mechanisms. It is also demonstrated that improvement in the FE properties can be achieved by implanting tungsten ions into these SiC/Si heterostructures.

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