Field emission energy distributions from individual multiwalled carbon nanotubes

Fransen, M.; Rooy, T.L. van; Kruit, P.

doi:10.1016/s0169-4332(99)00056-2

Cited by 228 publications

(121 citation statements)

References 40 publications

Supporting

Mentioning

119

Contrasting

Order By: Relevance

“…They move to the left with increasing extraction bias as a result of field penetration, which lowers the potential energy at the apex of the nanotube as well as its mean value in the whole nanotube. Similar displacements have been observed experimentally with carbon emitters [3,21]. The peaks tend to the positions observed in distribution of incident states at z=O.…”

Section: Field Emission From An Open (55) Carbon Nanotubesupporting

confidence: 84%

“…Like other forms of nanostructured carbon, the nanotubes [1][2][3] show interesting fieldemission properties such as low extracting field, high current density, and seemingly long operating time. In general, the current-voltage characteristics of the nanotubes are found to follow a Fowler-Nordheim type tunneling law [4] with an emitter work function varying between 4 to 5 eV depending on the type of nanotubes.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Three-dimensional calculation of field emission from carbon nanotubes using a transfermatrix methodology

2001

View full text Add to dashboard Cite

We present simulations of field emission from carbon nanotubes, using a transfer-matrix methodology. By repeating periodically a basic unit of the nanotubes in the region preceding that containing the extraction field, specific band-structure effects are included in the distribution of incident states, i.e. those entering the field region. The structures considered are the metallic (5,5) and the semiconducting (10,0) single-wall carbon nanotubes. The total-energy distributions of incident states show the gap of the (10,0) and the expected flat region for the (5,5) nanotube. The field-emitted electron energy distributions contain peaks, which are sharper for the (10,0) structure. Except for peaks associated with van Hove singularities in the distribution of incident states or with the Fermi level in the case of a metallic structure, all peaks are shifted to lower energies by the electric field.

show abstract

Section: Field Emission From An Open (55) Carbon Nanotubesupporting

confidence: 84%

Section: Introductionmentioning

confidence: 99%

Three-dimensional calculation of field emission from carbon nanotubes using a transfermatrix methodology

2001

View full text Add to dashboard Cite

show abstract

“…Mostly this will lead to an underestimation of the brightness. The method used by Fransen et al 4 and de Jonge 5 offers the best chance of giving the real value of the geometrical source size and thus the brightness. For an emitter as analyzed by Hata et al 2 even the definition of brightness is a problem.…”

Section: ͑1͒mentioning

confidence: 99%

Source brightness and useful beam current of carbon nanotubes and other very small emitters

Kruit

Bezuijen

Barth

2006

Journal of Applied Physics

View full text Add to dashboard Cite

The potential application of carbon nanotubes as electron sources in electron microscopes is analyzed. The resolution and probe current that can be obtained from a carbon nanotube emitter in a low-voltage scanning electron microscope are calculated and compared to the state of the art using Schottky electron sources. Many analytical equations for probe-size versus probe-current relations in different parameter regimes are obtained. It is shown that for most carbon nanotube emitters, the gun lens aberrations are larger than the emitters' virtual source size and thus restrict the microscope's performance. The result is that the advantages of the higher brightness of nanotube emitters are limited unless the angular emission current is increased over present day values or the gun lens aberrations are decreased. For some nanotubes with a closed cap, it is known that the emitted electron beam is coherent over the full emission cone. We argue that for such emitters the parameter "brightness" becomes meaningless. The influence of phase variations in the electron wave front emitted from such a nanotube emitter on the focusing of the electron beam is analyzed.

show abstract

“…Relatively narrow energy electron emission peaks from carbon nanotubes have been reported which may be of use in a vacuum based device. 45 Since the DOS in the reservoirs fixes the number of electrons available for transport in a certain energy range in ballistic devices, the reduction of power in narrow transmission probability devices, with only modest gains in electronic efficiency, is expected to be undesirable in the presence of phonon heat leaks. It is likely that the best way to simultaneously achieve high electronic efficiency and high power in a ballistic device is to design the structure such that the transmission probability rises sharply from zero to one and remains close to unity beyond this.…”

Section: A Ballistic Devicesmentioning

confidence: 99%

Electronic efficiency in nanostructured thermionic and thermoelectric devices

et al. 2005

View full text Add to dashboard Cite

Advances in solid-state device design now allow the spectrum of transmitted electrons in thermionic and thermoelectric devices to be engineered in ways that were not previously possible. Here we show that the shape of the electron energy spectrum in these devices has a significant impact on their performance. We distinguish between traditional thermionic devices where electron momentum is filtered in the direction of transport only and a second type, in which the electron filtering occurs according to total electron momentum. Such "total momentum filtered" thermionic devices could potentially be implemented in, for example, quantum dot superlattices. It is shown that whilst total momentum filtered thermionic devices may achieve an efficiency equal to the Carnot value, traditional thermionic devices are limited to an efficiency below this. Our second main result is that the electronic efficiency of a device is not only improved by reducing the width of the transmission filter as has previously been shown, but also strongly depends on whether the transmission probability rises sharply from zero to full transmission. The benefit of increasing efficiency through a sharply rising transmission probability is that it can be achieved without sacrificing device power, in contrast to the use of a narrow transmission filter which can greatly reduce power. We show that devices that have a sharply rising transmission probability significantly outperform those that do not and that such transmission probabilities may be achieved with practical single and multibarrier devices. We discuss how the shape of the electron energy spectrum will also have an effect on the electronic efficiency of thermoelectric devices due to mathematical equivalences in the ballistic and diffusive formalisms. Finally, we present an experimental measure that might be used to provide an indication of the nature of the electron energy spectrum and the electronic efficiency of a ballistic device.

show abstract

Field emission energy distributions from individual multiwalled carbon nanotubes

Cited by 228 publications

References 40 publications

Three-dimensional calculation of field emission from carbon nanotubes using a transfermatrix methodology

Three-dimensional calculation of field emission from carbon nanotubes using a transfermatrix methodology

Source brightness and useful beam current of carbon nanotubes and other very small emitters

Electronic efficiency in nanostructured thermionic and thermoelectric devices

Contact Info

Product

Resources

About