Two-photon photoemission from metals induced by picosecond laser pulses

Bechtel, James H.; Smith, W. L.; Bloembergen, N.

doi:10.1103/physrevb.15.4557

Cited by 150 publications

(80 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…where c is the efficiency [49,50]. Photoemission is a low-probability process, typically yielding less than one electron per ten thousand incident photons [51].…”

Section: Photonics 6 Photoemission and Photonicsmentioning

confidence: 99%

“…In photoemission, an electron can be excited with a single UV or higher energy photon or with multiple (n) lower energy photons, where the number of photons satisfies the energy requirement n × (hc/λ) > W , and W is the photoemission threshold energy at the surface [49,50]. The quantum efficiency of photoemission with photons above the photoemission threshold is ∼ 10 −4 [51].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Aberration Corrected Photoemission Electron Microscopy with Photonics Applications

Fitzgerald¹

2000

View full text Add to dashboard Cite

Photoemission electron microscopy (PEEM) uses photoelectrons excited from material surfaces by incident photons to probe the interaction of light with surfaces with nanometer-scale resolution. The point resolution of PEEM images is strongly limited by spherical and chromatic aberration. Image aberrations primarily originate from the acceleration of photoelectrons and imaging with the objective lens and vary strongly in magnitude with specimen emission characteristics. Spherical and chromatic aberration can be corrected with an electrostatic mirror, and here I develop a triode mirror with hyperbolic geometry that has two adjacent, field-adjustable regions. I present analytic and numerical models of the mirror and show that the optical properties agree to within a few percent. When this mirror is coupled with an electron lens, it can provide a large dynamic range of correction and the coefficients of spherical and chromatic aberration can be varied independently. I report on efforts to realize a triode mirror corrector, including design, characterization, and alignment in our microscope at Portland State University (PSU). PEEM may be used to investigate optically active nanostructures, and we show that photoelectron emission yields can be identified with diffraction, surface plasmons, and dielectric waveguiding.Furthermore, we find that photoelectron micrographs of nanostructured metal and dielectric structures correlate with electromagnetic field calculations. We conclude that photoemission is highly spatially sensitive to the electromagnetic field intensity, allowing the direct visualization of the interaction of light with material surfaces at nanometer scales and over a wide range of incident light frequencies.ii

show abstract

“…where c is the efficiency [49,50]. Photoemission is a low-probability process, typically yielding less than one electron per ten thousand incident photons [51].…”

Section: Photonics 6 Photoemission and Photonicsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Aberration Corrected Photoemission Electron Microscopy with Photonics Applications

Fitzgerald¹

2000

View full text Add to dashboard Cite

show abstract

“…Some of the most celebrated ones include the Richardson-Laue-Dushman model of thermionic emission [37,38], the Fowler-Nordheim theory of field-emission [20] and subsequent developments [39], the Murphy-Good theory that includes the effects of both heat and field [40], and more advanced treatments including significant recent work by Forbes and colleagues [41][42][43][44][45][46][47][48][49][50][51]; the (generalized) Fowler-DuBridge model that describes the combined effects of heat and multiphoton photoemission [52][53][54], Spicer's three-step photoemission model [55,56], and Jensen's general formulation that covers thermal-, fieldand photoemission [57]; and models for the analysis of electron scattering in solids (needed in the context of secondary electron emission) such as those by Browning, Joy and colleagues [58,59].…”

Section: Sourcementioning

confidence: 99%

“…The combination of light and heat in inducing electron emission from materials has been of interest since the first half of the last century as exemplified by the Fowler-DuBridge theory [52][53][54]. Typically, a photoemission experiment can be augmented by adding a substrate heater to allow for the study of the effect of temperature on the photoemission current, as the light source itself may not be intense enough to lead to substantial temperature rise.…”

Section: Photoemission Thermionic Emission and Nonlinearmentioning

confidence: 99%

Carbon Nanotube Electron Sources: From Electron Beams to Energy Conversion and Optophononics

Nojeh

2014

ISRN Nanomaterials

View full text Add to dashboard Cite

Carbon nanotubes have a host of properties that make them excellent candidates for electron emitters. A significant amount of research has been conducted on nanotube-based field-emitters over the past two decades, and they have been investigated for devices ranging from flat-panel displays to vacuum tubes and electron microscopes. Other electron emission mechanisms from carbon nanotubes, such as photoemission, secondary emission, and thermionic emission, have also been studied, although to a lesser degree than field-emission. This paper presents an overview of the topic, with emphasis on these less-explored mechanisms, although field-emission is also discussed. We will see that not only is electron emission from nanotubes promising for electronsource applications, but also its study could reveal unusual phenomena and open the door to new devices that are not directly related to electron beams.

show abstract

“…An electron emission should then be observed, even when the excitation photon energy is lower than the surface barrier potential f. A study of these electrons (overall yields, angular distribution, energy distribution) must yield information about the "heating" mechanisms. Up to now, most experiments of this kind have been carried out on metals (3)(4)(5)(6). We report here the preliminary results of such a study on crystalline silicon.…”

mentioning

confidence: 99%

Hot Electron Emission From Silicon Under Pulsed Laser Excitation

Bensoussan¹,

Moison²

1981

J. Phys. Colloques

View full text Add to dashboard Cite

Résumé : -Sous excitation modérée par un laser â impulsions, le silicium émet des électrons dans le vide à des énergies de photon bien en dessous du travail de sortie $. Deux processus distincts sont observés : 1) une photoémission à deux quanta à de faibles flux de photon et à de fortes énergies de photon (> $/2) et 2) une .thermoémission à de forts flux de photon ou à de faibles énergies de photon (< $/2). Alors que le premier effet donne des informations sur les propriétés de structures de bande électronique du silicium sous excitation, le second sonde les propriétés du plasma de porteurs photogé-nérés. La température de ce plasma est évaluée à (1800 ± 100) K pour une irradiance de (0.04 Jcm , 2ns).Abstract : -Under moderate pulsed laser excitation, silicon is shown to emit electrons in the vacuum at photon energies well below the work function $. Two distinct processes are observed, 1) a two-quantum photoemission at low photon fluxes and high photon energies (> $/2) arid, 2) a thermoemission at high photon fluxes or low photon energies (< §/2). While the first effect yields information about the electronic structure of silicon under irradiation, the second one probes the properties of the carrier plasma. The temperature of this plasma has been evaluated to (1800 + 100) K for (0.04 Jem , 2 ns) irradiances.1. Introduction -In the past few years, the behavior of semiconductors under intense pulsed laser excitation has attracted a great deal of attention, and several anomalous effects have been attributed to the high carrier densities involved (1). The interest for such topics has been renewed and focused by the controversy on pulsed laser annealing of silicon (2). It is usually agreed anyhow, that the formation of a hot electron-hole plasma precedes and initiates the observed effects. If thermalization of this plasma takes place, many electrons are likely to be driven high in the conduction band, and a number of them higher than the vacuum level. An electron emission should then be observed, even when the excitation photon energy is lower than the surface barrier potential f. A study of these electrons (overall yields, angular distribution, energy distribution) must yield information about the "heating" mechanisms. Up to now, most experiments of this kind have been carried out on metals (3-6). We report here the preliminary results of such a study on crystalline silicon.

show abstract

Two-photon photoemission from metals induced by picosecond laser pulses

Cited by 150 publications

References 23 publications

Aberration Corrected Photoemission Electron Microscopy with Photonics Applications

Aberration Corrected Photoemission Electron Microscopy with Photonics Applications

Carbon Nanotube Electron Sources: From Electron Beams to Energy Conversion and Optophononics

Hot Electron Emission From Silicon Under Pulsed Laser Excitation

Contact Info

Product

Resources

About