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begins to contribute significant emission current. In this regime, the combined effects of field-enhanced thermionic and field emission can be modeled by the Murphy–Good equation for thermo-field (T-F) emission. At even higher fields, FN tunneling becomes the dominant electron emission mechanism, and
24:
267:
189:
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Thermionic emission can also be enhanced by interaction with other forms of excitation such as light. For example, excited Cs-vapours in thermionic converters form clusters of Cs-
361:. This equation is relatively accurate for electric field strengths lower than about 10 V m. For electric field strengths higher than 10 V m, so-called
399:
195:
88:
459:
601:
557:
Svensson, R.; Holmlid, L. (1992). "Very low work function surfaces from condensed excited states: Rydber matter of cesium".
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Electron emission that takes place in the field-and-temperature-regime where this modified equation applies is often called
58:
at the emitter surface. Without the field, the surface barrier seen by an escaping Fermi-level electron has height
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which yield a decrease of collector emitting work function from 1.5 eV to 1.0–0.7 eV. Due to long-lived nature of
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this low work function remains low which essentially increases the low-temperature converter’s efficiency.
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Mal'Shukov, A. G.; Chao, K. A. (2001). "Opto-Thermionic
Refrigeration in Semiconductor Heterostructures".
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523:
486:
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Murphy, E. L.; Good, G. H. (1956). "Thermionic
Emission, Field Emission, and the Transition Region".
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will be biased negative relative to its surroundings. This creates an electric field of magnitude
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equal to the local work-function. The electric field lowers the surface barrier by an amount Δ
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Kiziroglou, M. E.; Li, X.; Zhukov, A. A.; De Groot, P. A. J.; De Groot, C. H. (2008).
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262:{\displaystyle \Delta W={\sqrt {{q_{e}}^{3}F \over 4\pi \epsilon _{0}}},}
184:{\displaystyle J(F,T,W)=A_{\mathrm {G} }T^{2}e^{-(W-\Delta W) \over kT}}
400:"Thermionic field emission at electrodeposited Ni-Si Schottky barriers"
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multiplied by a material-specific correction factor
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46:. In electron emission devices, especially
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350:Schottky-emitter electron source of an
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368:"cold field electron emission (CFE)"
448:Handbook of Charged Particle Optics
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36:field enhanced thermionic emission
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343:which is typically of order 0.5.
284:is the temperature of the metal,
363:Fowler–Nordheim (FN) tunneling
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1:
577:10.1016/0039-6028(92)91335-9
536:10.1103/PhysRevLett.86.5570
82:). This gives the equation
52:thermionic electron emitter
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15:
429:10.1016/j.sse.2008.03.002
602:Condensed matter physics
499:10.1103/PhysRev.102.1464
40:condensed matter physics
16:Not to be confused with
515:Physical Review Letters
408:Solid-State Electronics
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563:. 269/270: 695–699.
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569:1992SurSc.269..695S
528:2001PhRvL..86.5570M
491:1956PhRv..102.1464M
444:"Schottky emission"
442:Orloff, J. (2008).
421:2008SSEle..52.1032K
352:Electron microscope
320:vacuum permittivity
68:Richardson equation
38:is a phenomenon in
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298:Boltzmann constant
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44:Walter H. Schottky
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522:(24): 5570–5573.
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359:Schottky emission
309:Elementary charge
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454:. pp. 5–6.
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596:Categories
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452:CRC Press
244:ϵ
240:π
200:Δ
161:Δ
158:−
149:−
544:11415303
370:regime.
565:Bibcode
524:Bibcode
487:Bibcode
417:Bibcode
318:is the
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272:where
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540:PMID
456:ISBN
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341:R
338:λ
334:0
331:A
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324:A
316:0
313:ε
305:e
302:q
294:k
286:W
282:T
274:J
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