text:
Photoelectric effect
From Wikipedia, the free encyclopedia
Jump to: navigation, search
Light–matter interaction
Low-energy phenomena:
Photoelectric effect
Mid-energy phenomena:
Thomson scattering
Compton scattering
High-energy phenomena:
Pair production
v
t
e
The photoelectric effect is the emission of electrons or other free carriers when light is shone onto a material. Electrons emitted in this manner can be called photo electrons. The phenomenon is commonly studied in electronic physics, as well as in fields of chemistry, such as quantum chemistry or electrochemistry.
According to classical electromagnetic theory, this effect can be attributed to the transfer of energy from the light to an electron. From this perspective, an alteration in the intensity of light would induce changes in the kinetic energy of the electrons emitted from the metal. Furthermore, according to this theory, a sufficiently dim light would be expected to show a time lag between the initial shining of its light and the subsequent emission of an electron. However, the experimental results did not correlate with either of the two predictions made by classical theory.
Instead, electrons are dislodged only by the impingement of photons when those photons reach or exceed a threshold frequency (energy). Below that threshold, no electrons are emitted from the material regardless of the light intensity or the length of time of exposure to the light (rarely, an electron will escape by absorbing two or more quanta. However, this is extremely rare because by the time it absorbs enough quanta to escape, the electron will probably have emitted the rest of the quanta.). To make sense of the fact that light can eject electrons even if its intensity is low, Albert Einstein proposed that a beam of light is not a wave propagating through space, but rather a collection of discrete wave packets (photons), each with energy hν. This shed light on Max Planck's previous discovery of the Planck relation (E = hν) linking energy (E) and frequency (ν) as arising from quantization of energy. The factor h is known as the Planck constant.[1][2]
In 1887, Heinrich Hertz[2][3] discovered that electrodes illuminated with ultraviolet light create electric sparks more easily. In 1900, while studying black-body radiation, the German physicist Max Planck suggested that the energy carried by electromagnetic waves could only be released in "packets" of energy. In 1905, Albert Einstein published a paper advancing the hypothesis that light energy is carried in discrete quantized packets to explain experimental data from the photoelectric effect. This model contributed to the development of quantum mechanics. In 1914, Robert Millikan's experiment supported Einstein's model of the photoelectric effect. Einstein was awarded the Nobel Prize in 1921 for "his discovery of the law of the photoelectric effect",[4] and Millikan was awarded the Nobel Prize in 1923 for "his work on the elementary charge of electricity and on the photoelectric effect".[5]
The photoelectric effect requires photons with energies approaching zero (in the case of negative electron affinity) to over 1 MeV for core electrons in elements with a high atomic number. Emission of conduction electrons from typical metals usually requires a few electron-volts, corresponding to short-wavelength visible or ultraviolet light. Study of the photoelectric effect led to important steps in understanding the quantum nature of light and electrons and influenced the formation of the concept of wave–particle duality.[1] Other phenomena where light affects the movement of electric charges include the photoconductive effect (also known as photoconductivity or photoresistivity), the photovoltaic effect, and the photoelectrochemical effect.
Photoemission can occur from any material, but it is most easily observable from metals or other conductors because the process produces a charge imbalance, and if this charge imbalance is not neutralized by current flow (enabled by conductivity), the potential barrier to emission increases until the emission current ceases. It is also usual to have the emitting surface in a vacuum, since gases impede the flow of photoelectrons and make them difficult to observe. Additionally, the energy barrier to photoemission is usually increased by thin oxide layers on metal surfaces if the metal has been exposed to oxygen, so most practical experiments and devices based on the photoelectric effect use clean metal surfaces in a vacuum.
When the photoelectron is emitted into a solid rather than into a vacuum, the term internal photoemission is often used, and emission into a vacuum distinguished as external photoemission.
Schematic of experimental apparatus to demonstrate the photoelectric effect. The filter passes light of certain wavelengths from the lamp at left. The light strikes the curved electrode, and electrons are emitted. The adjustable voltage can be increased until the current stops flowing. This "stopping voltage" is a function only of the electrode material and the frequency of the incident light, and is not affected by the intensity of the light.
Contents
[hide]
1 Emission mechanism
1.1 Experimental observations of photoelectric emission
1.2 Mathematical description
1.3 Stopping potential
1.4 Three-step model
2 History
2.1 19th century
2.2 20th century
3 Uses and effects
3.1 Photomultipliers
3.2 Image sensors
3.3 Gold-leaf electroscope
3.4 Photoelectron spectroscopy
3.5 Spacecraft
3.6 Moon dust
3.7 Night vision devices
4 Cross section
5 See also
6 References
7 External links
Emission mechanism[edit]
The photons of a light beam have a characteristic energy proportional to the frequency of the light. In the photoemission process, if an electron within some material absorbs the energy of one photon and acquires more energy than the work function (the electron binding energy) of the material, it is ejected. If the photon energy is too low, the electron is unable to escape the material. Since an increase in the intensity of low-frequency light will only increase the number of low-energy photons sent over a given interval of time, this change in intensity will not create any single photon with enough energy to dislodge an electron. Thus, the energy of the emitted electrons does not depend on the intensity of the incoming light, but only on the energy (equivalently frequency) of the individual photons. It is an interaction between the incident photon and the outermost electrons.
Electrons can absorb energy from photons when irradiated, but they usually follow an "all or nothing" principle. All of the energy from one photon must be absorbed and used to liberate one electron from atomic binding, or else the energy is re-emitted. If the photon energy is absorbed, some of the energy liberates the electron from the atom, and the rest contributes to the electron's kinetic energy as a free particle.[6][7][8]
Experimental observations of photoelectric emission[edit]
The theory of the photoelectric effect must explain the experimental observations of the emission of electrons from an illuminated metal surface.
For a given metal, there exists a certain minimum frequency of incident radiation below which no photoelectrons are emitted. This frequency is called the threshold frequency. Increasing the frequency of the incident beam, keeping the number of incident photons fixed (this would result in a proportionate increase in energy) increases the maximum kinetic energy of the photoelectrons emitted. Thus the stopping voltage increases. The number of electrons also changes because the probability that each photon results in an emitted electron is a function of photon energy. If the intensity of the incident radiation of a given frequency is increased, there is no effect on the kinetic energy of each photoelectron.
Above the threshold frequency, the maximum kinetic energy of the emitted photoelectron depends on the frequency of the incident light, but is independent of the intensity of the incident light so long as the latter is not too high.[9]
For a given metal and frequency of incident radiation, the rate at which photoelectrons are ejected is directly proportional to the intensity of the incident light. An increase in the intensity of the incident beam (keeping the frequency fixed) increases the magnitude of the photoelectric current, although the stopping voltage remains the same.
The time lag between the incidence of radiation and the emission of a photoelectron is very small, less than 10−9 second.
The direction of distribution of emitted electrons peaks in the direction of polarization (the direction of the electric field) of the incident light, if it is linearly polarized.[10]
Mathematical description[edit]
In 1905, Einstein proposed an explanation of the photoelectric effect using a concept first put forward by Max Planck that light waves consist of tiny bundles or packets of energy known as photons or quanta.
Diagram of the maximum kinetic energy as a function of the frequency of light on zinc
The maximum kinetic energy K max {\displaystyle K_{\max }} of an ejected electron is given by
K max = h f − φ , {\displaystyle K_{\max }=h\,f-\varphi ,}
where h {\displaystyle h} is the Planck constant and f {\displaystyle f} is the frequency of the incident photon. The term φ {\displaystyle \varphi } is the work function (sometimes denoted W {\displaystyle W} , or ϕ {\displaystyle \phi } [11]), which gives the minimum energy required to remove a delocalised electron from the surface of the metal. The work function satisfies
φ = h f 0 , {\displaystyle \varphi =h\,f_{0},}
where f 0 {\displaystyle f_{0}} is the threshold frequency for the metal. The maximum kinetic energy of an ejected electron is then
K max = h ( f − f 0 ) . {\displaystyle K_{\max }=h\left(f-f_{0}\right).}
Kinetic energy is positive, so we must have f > f 0 {\displaystyle f>f_{0}} for the photoelectric effect to occur.[12]
Stopping potential[edit]
The relation between current and applied voltage illustrates the nature of the photoelectric effect. For discussion, a light source illuminates a plate P, and another plate electrode Q collects any emitted electrons. We vary the potential between P and Q and measure the current flowing in the external circuit between the two plates.
Work function and cut off frequency
If the frequency and the intensity of the incident radiation are fixed, the photoelectric current increases gradually with an increase in the positive potential on the collector electrode until all the photoelectrons emitted are collected. The photoelectric current attains a saturation value and does not increase further for any increase in the positive potential. The saturation current increases with the increase of the light intensity. It also increases with greater frequencies due to a greater probability of electron emission when collisions happen with higher energy photons.
If we apply a negative potential to the collector plate Q with respect to the plate P and gradually increase it, the photoelectric current decreases, becoming zero at a certain negative potential. The negative potential on the collector at which the photoelectric current becomes zero is called the stopping potential or cut off potential[13]
i. For a given frequency of incident radiation, the stopping potential is independent of its intensity.
ii. For a given frequency of incident radiation, the stopping potential is determined by the maximum kinetic energy K max {\displaystyle K_{\max }} of the photoelectrons that are emitted. If qe is the charge on the electron and V 0 {\displaystyle V_{0}} is the stopping potential, then the work done by the retarding potential in stopping the electron is q e V 0 {\displaystyle q_{e}V_{0}} , so we have
q e V 0 = K max . {\displaystyle q_{e}V_{0}=K_{\max }.}
Recalling
K max = h ( f − f 0 ) , {\displaystyle K_{\max }=h\left(f-f_{0}\right),}
we see that the stopping voltage varies linearly with frequency of light, but depends on the type of material. For any particular material, there is a threshold frequency that must be exceeded, independent of light intensity, to observe any electron emission.
Three-step model[edit]
In the X-ray regime, the photoelectric effect in crystalline material is often decomposed into three steps:[14]:50–51
Inner photoelectric effect (see photodiode below[clarification needed]). The hole left behind can give rise to Auger effect, which is visible even when the electron does not leave the material. In molecular solids phonons are excited in this step and may be visible as lines in the final electron energy. The inner photoeffect has to be dipole allowed.[clarification needed] The transition rules for atoms translate via the tight-binding model onto the crystal.[clarification needed] They are similar in geometry to plasma oscillations in that they have to be transversal.
Ballistic transport[clarification needed] of half of the electrons to the surface. Some electrons are scattered.
Electrons escape from the material at the surface.
In the three-step model, an electron can take multiple paths through these three steps. All paths can interfere in the sense of the path integral formulation. For surface states and molecules the three-step model does still make some sense as even most atoms have multiple electrons which can scatter the one electron leaving.[citation needed]
History[edit]
When a surface is exposed to electromagnetic radiation above a certain threshold frequency (typically visible light for alkali metals, near ultraviolet for other metals, and extreme ultraviolet for non-metals), the radiation is absorbed and electrons are emitted. Light, and especially ultra-violet light, discharges negatively electrified bodies with the production of rays of the same nature as cathode rays.[15] Under certain circumstances it can directly ionize gases.[15] The first of these phenomena was discovered by Hertz and Hallwachs in 1887.[15] The second was announced first by Philipp Lenard in 1900.[15]
The ultra-violet light to produce these effects may be obtained from an arc lamp, or by burning magnesium, or by sparking with an induction coil between zinc or cadmium terminals, the light from which is very rich in ultra-violet rays. Sunlight is not rich in ultra-violet rays, as these have been absorbed by the atmosphere, and it does not produce nearly so large an effect as the arc-light. Many substances besides metals discharge negative electricity under the action of ultraviolet light: lists of these substances will be found in papers by G. C. Schmidt[16] and O. Knoblauch.[17]
19th century[edit]
In 1839, Alexandre Edmond Becquerel discovered the photovoltaic effect while studying the effect of light on electrolytic cells.[18] Though not equivalent to the photoelectric effect, his work on photovoltaics was instrumental in showing a strong relationship between light and electronic properties of materials. In 1873, Willoughby Smith discovered photoconductivity in selenium while testing the metal for its high resistance properties in conjunction with his work involving submarine telegraph cables.[19]
Johann Elster (1854–1920) and Hans Geitel (1855–1923), students in Heidelberg, developed the first practical photoelectric cells that could be used to measure the intensity of light.[20][21]:458 Elster and Geitel had investigated with great success the effects produced by light on electrified bodies.[22]
In 1887, Heinrich Hertz observed the photoelectric effect and the production and reception of electromagnetic waves.[15] He published these observations in the journal Annalen der Physik. His receiver consisted of a coil with a spark gap, where a spark would be seen upon detection of electromagnetic waves. He placed the apparatus in a darkened box to see the spark better. However, he noticed that the maximum spark length was reduced when in the box. A glass panel placed between the source of electromagnetic waves and the receiver absorbed ultraviolet radiation that assisted the electrons in jumping across the gap. When removed, the spark length would increase. He observed no decrease in spark length when he replaced glass with quartz, as quartz does not absorb UV radiation. Hertz concluded his months of investigation and reported the results obtained. He did not further pursue investigation of this effect.
The discovery by Hertz[23] in 1887 that the incidence of ultra-violet light on a spark gap facilitated the passage of the spark, led immediately to a series of investigations by Hallwachs,[24] Hoor,[25] Righi[26] and Stoletow[27][28][29][30][31][32][33] on the effect of light, and especially of ultra-violet light, on charged bodies. It was proved by these investigations that a newly cleaned surface of zinc, if charged with negative electricity, rapidly loses this charge however small it may be when ultra-violet light falls upon the surface; while if the surface is uncharged to begin with, it acquires a positive charge when exposed to the light, the negative electrification going out into the gas by which the metal is surrounded; this positive electrification can be much increased by directing a strong airblast against the surface. If however the zinc surface is positively electrified it suffers no loss of charge when exposed to the light: this result has been questioned, but a very careful examination of the phenomenon by Elster and Geitel[34] has shown that the loss observed under certain circumstances is due to the discharge by the light reflected from the zinc surface of negative electrification on neighbouring conductors induced by the positive charge, the negative electricity under the influence of the electric field moving up to the positively electrified surface.[35]
With regard to the Hertz effect, the researches from the start showed a great complexity of the phenomenon of photoelectric fatigue — that is, the progressive diminution of the effect observed upon fresh metallic surfaces. According to an important research by Wilhelm Hallwachs, ozone played an important part in the phenomenon.[36] However, other elements enter such as oxidation, the humidity, the mode of polish of the surface, etc. It was at the time not even sure that the fatigue is absent in a vacuum.
In the period from February 1888 and until 1891, a detailed analysis of photoeffect was performed by Aleksandr Stoletov with results published in 6 works;[37][38][39][40][41][42] four of them in Comptes Rendus, one review in Physikalische Revue (translated from Russian), and the last work in Journal de Physique. First, in these works Stoletov invented a new experimental setup which was more suitable for a quantitative analysis of photoeffect. Using this setup, he discovered the direct proportionality between the intensity of light and the induced photo electric current (the first law of photoeffect or Stoletov's law). One of his other findings resulted from measurements of the dependence of the intensity of the electric photo current on the gas pressure, where he found the existence of an optimal gas pressure Pm corresponding to a maximum photocurrent; this property was used for a creation of solar cells.[citation needed]
In 1899, J. J. Thomson investigated ultraviolet light in Crookes tubes.[43] Thomson deduced that the ejected particles were the same as those previously found in the cathode ray, later called electrons, which he called "corpuscles". In the research, Thomson enclosed a metal plate (a cathode) in a vacuum tube, and exposed it to high frequency radiation.[44] It was thought that the oscillating electromagnetic fields caused the atoms' field to resonate and, after reaching a certain amplitude, caused a subatomic "corpuscle" to be emitted, and current to be detected. The amount of this current varied with the intensity and colour of the radiation. Larger radiation intensity or frequency would produce more current.[citation needed]
20th century[edit]
The discovery of the ionization of gases by ultra-violet light was made by Philipp Lenard in 1900. As the effect was produced across several centimeters of air and made very great positive and small negative ions, it was natural to interpret the phenomenon, as did J. J. Thomson, as a Hertz effect upon the solid or liquid particles present in the gas.[15]
In 1902, Lenard observed that the energy of individual emitted electrons increased with the frequency (which is related to the color) of the light.[6]
This appeared to be at odds with Maxwell's wave theory of light, which predicted that the electron energy would be proportional to the intensity of the radiation.
Lenard observed the variation in electron energy with light frequency using a powerful electric arc lamp which enabled him to investigate large changes in intensity, and that had sufficient power to enable him to investigate the variation of potential with light frequency. His experiment directly measured potentials, not electron kinetic energy: he found the electron energy by relating it to the maximum stopping potential (voltage) in a phototube. He found that the calculated maximum electron kinetic energy is determined by the frequency of the light. For example, an increase in frequency results in an increase in the maximum kinetic energy calculated for an electron upon liberation – ultraviolet radiation would require a higher applied stopping potential to stop current in a phototube than blue light. However Lenard's results were qualitative rather than quantitative because of the difficulty in performing the experiments: the experiments needed to be done on freshly cut metal so that the pure metal was observed, but it oxidised in a matter of minutes even in the partial vacuums he used. The current emitted by the surface was determined by the light's intensity, or brightness: doubling the intensity of the light doubled the number of electrons emitted from the surface.
The researches of Langevin and those of Eugene Bloch[45] have shown that the greater part of the Lenard effect is certainly due to this 'Hertz effect'. The Lenard effect upon the gas[clarification needed] itself nevertheless does exist. Refound by J. J. Thomson[46] and then more decisively by Frederic Palmer, Jr.,[47][48] it was studied and showed very different characteristics than those at first attributed to it by Lenard.[15]
In 1905, Albert Einstein solved this apparent paradox by describing light as composed of discrete quanta, now called photons, rather than continuous waves. Based upon Max Planck's theory of black-body radiation, Einstein theorized that the energy in each quantum of light was equal to the frequency multiplied by a constant, later called Planck's constant. A photon above a threshold frequency has the required energy to eject a single electron, creating the observed effect. This discovery led to the quantum revolution in physics and earned Einstein the Nobel Prize in Physics in 1921.[49] By wave-particle duality the effect can be analyzed purely in terms of waves though not as conveniently.[50]
Albert Einstein's mathematical description of how the photoelectric effect was caused by absorption of quanta of light was in one of his 1905 papers, named "On a Heuristic Viewpoint Concerning the Production and Transformation of Light". This paper proposed the simple description of "light quanta", or photons, and showed how they explained such phenomena as the photoelectric effect. His simple explanation in terms of absorption of discrete quanta of light explained the features of the phenomenon and the characteristic frequency.
The idea of light quanta began with Max Planck's published law of black-body radiation ("On the Law of Distribution of Energy in the Normal Spectrum"[51]) by assuming that Hertzian oscillators could only exist at energies E proportional to the frequency f of the oscillator by E = hf, where h is Planck's constant. By assuming that light actually consisted of discrete energy packets, Einstein wrote an equation for the photoelectric effect that agreed with experimental results. It explained why the energy of photoelectrons was dependent only on the frequency of the incident light and not on its intensity: a low-intensity, high-frequency source could supply a few high energy photons, whereas a high-intensity, low-frequency source would supply no photons of sufficient individual energy to dislodge any electrons. This was an enormous theoretical leap, but the concept was strongly resisted at first because it contradicted the wave theory of light that followed naturally from James Clerk Maxwell's equations for electromagnetic behavior, and more generally, the assumption of infinite divisibility of energy in physical systems. Even after experiments showed that Einstein's equations for the photoelectric effect were accurate, resistance to the idea of photons continued, since it appeared to contradict Maxwell's equations, which were well understood and verified.
Einstein's work predicted that the energy of individual ejected electrons increases linearly with the frequency of the light. Perhaps surprisingly, the precise relationship had not at that time been tested. By 1905 it was known that the energy of photoelectrons increases with increasing frequency of incident light and is independent of the intensity of the light. However, the manner of the increase was not experimentally determined until 1914 when Robert Andrews Millikan showed that Einstein's prediction was correct.[7]
The photoelectric effect helped to propel the then-emerging concept of wave–particle duality in the nature of light. Light simultaneously possesses the characteristics of both waves and particles, each being manifested according to the circumstances. The effect was impossible to understand in terms of the classical wave description of light,[52][53][54] as the energy of the emitted electrons did not depend on the intensity of the incident radiation. Classical theory predicted that the electrons would 'gather up' energy over a period of time, and then be emitted.[53][55]
Uses and effects[edit]
Photomultipliers[edit]
Main article: Photomultiplier
These are extremely light-sensitive vacuum tubes with a photocathode coated onto part (an end or side) of the inside of the envelope. The photocathode contains combinations of materials such as caesium, rubidium and antimony specially selected to provide a low work function, so when illuminated even by very low levels of light, the photocathode readily releases electrons. By means of a series of electrodes (dynodes) at ever-higher potentials, these electrons are accelerated and substantially increased in number through secondary emission to provide a readily detectable output current. Photomultipliers are still commonly used wherever low levels of light must be detected.[56]
Image sensors[edit]
Video camera tubes in the early days of television used the photoelectric effect, for example, Philo Farnsworth's "Image dissector" used a screen charged by the photoelectric effect to transform an optical image into a scanned electronic signal.[57]
Gold-leaf electroscope[edit]
The gold leaf electroscope
Gold-leaf electroscopes are designed to detect static electricity. Charge placed on the metal cap spreads to the stem and the gold leaf of the electroscope. Because they then have the same charge, the stem and leaf repel each other. This will cause the leaf to bend away from the stem.
The electroscope is an important tool in illustrating the photoelectric effect. For example, if the electroscope is negatively charged throughout, there is an excess of electrons and the leaf is separated from the stem. If high-frequency light shines on the cap, the electroscope discharges and the leaf will fall limp. This is because the frequency of the light shining on the cap is above the cap's threshold frequency. The photons in the light have enough energy to liberate electrons from the cap, reducing its negative charge. This will discharge a negatively charged electroscope and further charge a positive electroscope. However, if the electromagnetic radiation hitting the metal cap does not have a high enough frequency (its frequency is below the threshold value for the cap), then the leaf will never discharge, no matter how long one shines the low-frequency light at the cap.[58]:389–390
Photoelectron spectroscopy[edit]
Since the energy of the photoelectrons emitted is exactly the energy of the incident photon minus the material's work function or binding energy, the work function of a sample can be determined by bombarding it with a monochromatic X-ray source or UV source, and measuring the kinetic energy distribution of the electrons emitted.[14]:14–20
Photoelectron spectroscopy is usually done in a high-vacuum environment, since the electrons would be scattered by gas molecules if they were present. However, some companies are now selling products that allow photoemission in air. The light source can be a laser, a discharge tube, or a synchrotron radiation source.[59]
The concentric hemispherical analyser (CHA) is a typical electron energy analyzer, and uses an electric field to change the directions of incident electrons, depending on their kinetic energies. For every element and core (atomic orbital) there will be a different binding energy. The many electrons created from each of these combinations will show up as spikes in the analyzer output, and these can be used to determine the elemental composition of the sample.
Spacecraft[edit]
The photoelectric effect will cause spacecraft exposed to sunlight to develop a positive charge. This can be a major problem, as other parts of the spacecraft are in shadow which will result in the spacecraft developing a negative charge from nearby plasmas. The imbalance can discharge through delicate electrical components. The static charge created by the photoelectric effect is self-limiting, because a higher charged object doesn't give up its electrons as easily as a lower charged object does.[60][61]
Moon dust[edit]
Light from the sun hitting lunar dust causes it to become charged through the photoelectric effect. The charged dust then repels itself and lifts off the surface of the Moon by electrostatic levitation.[62][63] This manifests itself almost like an "atmosphere of dust", visible as a thin haze and blurring of distant features, and visible as a dim glow after the sun has set. This was first photographed by the Surveyor program probes in the 1960s. It is thought that the smallest particles are repelled kilometers from the surface, and that the particles move in "fountains" as they charge and discharge.
Night vision devices[edit]
Photons hitting a thin film of alkali metal or semiconductor material such as gallium arsenide in an image intensifier tube cause the ejection of photoelectrons due to the photoelectric effect. These are accelerated by an electrostatic field where they strike a phosphor coated screen, converting the electrons back into photons. Intensification of the signal is achieved either through acceleration of the electrons or by increasing the number of electrons through secondary emissions, such as with a micro-channel plate. Sometimes a combination of both methods is used. Additional kinetic energy is required to move an electron out of the conduction band and into the vacuum level. This is known as the electron affinity of the photocathode and is another barrier to photoemission other than the forbidden band, explained by the band gap model. Some materials such as Gallium Arsenide have an effective electron affinity that is below the level of the conduction band. In these materials, electrons that move to the conduction band are all of sufficient energy to be emitted from the material and as such, the film that absorbs photons can be quite thick. These materials are known as negative electron affinity materials.
Cross section[edit]
The photoelectric effect is one interaction mechanism between photons and atoms. It is one of 12 theoretically possible interactions.[64]
At the high photon energies comparable to the electron rest energy of 6986818712184856999♠511 keV, Compton scattering, another process, may take place. Above twice this (6987163742436971400♠1.022 MeV) pair production may take place.[65] Compton scattering and pair production are examples of two other competing mechanisms.
Indeed, even if the photoelectric effect is the favoured reaction for a particular single-photon bound-electron interaction, the result is also subject to statistical processes and is not guaranteed, albeit the photon has certainly disappeared and a bound electron has been excited (usually K or L shell electrons at gamma ray energies). The probability of the photoelectric effect occurring is measured by the cross section of interaction, σ. This has been found to be a function of the atomic number of the target atom and photon energy. A crude approximation, for photon energies above the highest atomic binding energy, is given by:[66]
σ = c o n s t a n t ⋅ Z n E 3 {\displaystyle \sigma =\mathrm {constant} \cdot {\frac {Z^{n}}{E^{3}}}}
Here Z is atomic number and n is a number which varies between 4 and 5. (At lower photon energies a characteristic structure with edges appears, K edge, L edges, M edges, etc.) The obvious interpretation follows that the photoelectric effect rapidly decreases in significance, in the gamma ray region of the spectrum, with increasing photon energy, and that photoelectric effect increases steeply with atomic number. The corollary is that high-Z materials make good gamma-ray shields, which is the principal reason that lead (Z = 82) is a preferred and ubiquitous gamma radiation shield.[67]
See also[edit]
Renewable energy portal
Anomalous photovoltaic effect
Dember effect
Photo–Dember effect
Photomagnetic effect
Photochemistry
Timeline of mechanics and physics
References[edit]
^ Jump up to: a b Serway, R. A. (1990). Physics for Scientists & Engineers (3rd ed.). Saunders. p. 1150. ISBN 0-03-030258-7.
^ Jump up to: a b Sears, F. W.; Zemansky, M. W.; Young, H. D. (1983). University Physics (6th ed.). Addison-Wesley. pp. 843–844. ISBN 0-201-07195-9.
Jump up ^ Hertz, H. (1887). "Ueber den Einfluss des ultravioletten Lichtes auf die electrische Entladung" [On an effect of ultra-violet light upon the electrical discharge]. Annalen der Physik. 267 (8): S. 983–1000. Bibcode:1887AnP...267..983H. doi:10.1002/andp.18872670827.
Jump up ^ "The Nobel Prize in Physics 1921". Nobel Foundation. Retrieved 2013-03-16.
Jump up ^ "The Nobel Prize in Physics 1923". Nobel Foundation. Retrieved 2015-03-29.
^ Jump up to: a b Lenard, P. (1902). "Ueber die lichtelektrische Wirkung". Annalen der Physik. 313 (5): 149–198. Bibcode:1902AnP...313..149L. doi:10.1002/andp.19023130510.
^ Jump up to: a b Millikan, R. (1914). "A Direct Determination of "h."". Physical Review. 4 (1): 73–75. Bibcode:1914PhRv....4R..73M. doi:10.1103/PhysRev.4.73.2.
Jump up ^ Millikan, R. (1916). "A Direct Photoelectric Determination of Planck's "h"" (PDF). Physical Review. 7 (3): 355–388. Bibcode:1916PhRv....7..355M. doi:10.1103/PhysRev.7.355.
Jump up ^ Zhang, Q. (1996). "Intensity dependence of the photoelectric effect induced by a circularly polarized laser beam". Physics Letters A. 216 (1–5): 125. Bibcode:1996PhLA..216..125Z. doi:10.1016/0375-9601(96)00259-9.
Jump up ^ Bubb, F. (1924). "Direction of Ejection of Photo-Electrons by Polarized X-rays". Physical Review. 23 (2): 137–143. Bibcode:1924PhRv...23..137B. doi:10.1103/PhysRev.23.137.
Jump up ^ Mee, C.; Crundell, M.; Arnold, B.; Brown, W. (2011). International A/AS Level Physics. Hodder Education. p. 241. ISBN 978-0-340-94564-3.
Jump up ^ Fromhold, A. T. (1991). Quantum Mechanics for Applied Physics and Engineering. Courier Dover Publications. pp. 5–6. ISBN 978-0-486-66741-6.
Jump up ^ Gautreau, R.; Savin, W. (1999). Schaum's Outline of Modern Physics (2nd ed.). McGraw-Hill. pp. 60–61. ISBN 0-07-024830-3.
^ Jump up to: a b Hüfner, S. (2003). Photoelectron Spectroscopy: Principles and Applications. Springer. ISBN 3-540-41802-4.
^ Jump up to: a b c d e f g Report of the Board of Regents By Smithsonian Institution. Board of Regents, United States National Museum, Smithsonian Institution. p. 239.
Jump up ^ Schmidt, G. C. (1898) Wied. Ann. Uiv. p. 708.
Jump up ^ Knoblauch, O. (1899). Zeitschrift für Physikalische Chemie. xxix. p. 527.
Jump up ^ Vesselinka Petrova-Koch; Rudolf Hezel; Adolf Goetzberger (2009). High-Efficient Low-Cost Photovoltaics: Recent Developments. Springer. pp. 1–. ISBN 978-3-540-79358-8.
Jump up ^ Smith, W. (1873). "Effect of Light on Selenium during the passage of an Electric Current". Nature. 7 (173): 303. Bibcode:1873Natur...7R.303.. doi:10.1038/007303e0.
Jump up ^ Asimov, A. (1964) Asimov's Biographical Encyclopedia of Science and Technology, Doubleday, ISBN 0-385-04693-6.
Jump up ^ Robert Bud; Deborah Jean Warner (1998). Instruments of Science: An Historical Encyclopedia. Science Museum, London, and National Museum of American History, Smithsonian Institution. ISBN 978-0-8153-1561-2.
Jump up ^ Elster and Geitel arrange the metals in the following order with respect to their power of discharging negative electricity: rubidium, potassium, alloy of potassium and sodium, sodium, lithium, magnesium, thallium and zinc. For copper, platinum, lead, iron, cadmium, carbon, and mercury the effects with ordinary light are too small to be measurable. The order of the metals for this effect is the same as in Volta's series for contact-electricity, the most electropositive metals giving the largest photo-electric effect.
Jump up ^ Hertz, Wied. Ann. xxxi. p. 983, 1887.
Jump up ^ Hallwachs, Wied. Ann. xxxiii. p. 301, 1888.
Jump up ^ Hoor, Repertorium des Physik, xxv. p. 91, 1889.
Jump up ^ Bighi, C. R. cvi. p. 1349; cvii. p. 559, 1888
Jump up ^ Stoletow. C. R. cvi. pp. 1149, 1593; cvii. p. 91; cviii. p. 1241; Physikalische Revue, Bd. i., 1892.
Jump up ^ Stoletow, A. (1888). "Sur une sorte de courants electriques provoques par les rayons ultraviolets". Comptes Rendus. CVI: 1149. (Reprinted in Stoletow, M.A. (1888). "On a kind of electric current produced by ultra-violet rays". Philosophical Magazine Series 5. 26 (160): 317. doi:10.1080/14786448808628270. ; abstract in Beibl. Ann. d. Phys. 12, 605, 1888).
Jump up ^ Stoletow, A. (1888). "Sur les courants actino-electriqies au travers deTair". Comptes Rendus. CVI: 1593. (Abstract in Beibl. Ann. d. Phys. 12, 723, 1888).
Jump up ^ Stoletow, A. (1888). "Suite des recherches actino-electriques". Comptes Rendus. CVII: 91. (Abstract in Beibl. Ann. d. Phys. 12, 723, 1888).
Jump up ^ Stoletow, A. (1889). "Sur les phénomènes actino-électriques". Comptes Rendus. CVIII: 1241.
Jump up ^ Stoletow, A. (1889). "Актино-электрические исследовaния". Journal of the Russian Physico-chemical Society (in Russian). 21: 159.
Jump up ^ Stoletow, A. (1890). "Sur les courants actino-électriques dans l'air raréfié". Journal de Physique. 9: 468. doi:10.1051/jphystap:018900090046800.
Jump up ^ Elster and Geitel, Wied. Ann. xxxviii. pp. 40, 497, 1889; xli. p. 161, 1890; xlii. p. 564, 1891; xliii. p. 225, 1892; lii. p. 433, 1894 ; lv. p. 684, 1895.
Jump up ^ Thomson, J. J. (2005). Conduction of Electricity Through Gases. Watchmaker Publishing. ISBN 978-1-929148-49-3. Retrieved 9 July 2011.
Jump up ^ Hallwachs, W. (1907). "Über die lichtelektrische Ermüdung". Annalen der Physik. 328 (8): 459–516. Bibcode:1907AnP...328..459H. doi:10.1002/andp.19073280807.
Jump up ^ Stoletow, A. (1888). "Sur une sorte de courants electriques provoques par les rayons ultraviolets". Comptes Rendus. CVI: 1149. (Reprinted in Stoletow, M.A. (1888). "On a kind of electric current produced by ultra-violet rays". Philosophical Magazine Series 5. 26 (160): 317. doi:10.1080/14786448808628270. ; abstract in Beibl. Ann. d. Phys. 12, 605, 1888).
Jump up ^ Stoletow, A. (1888). "Sur les courants actino-electriques au travers deTair". Comptes Rendus. CVI: 1593. (Abstract in Beibl. Ann. d. Phys. 12, 723, 1888).
Jump up ^ Stoletow, A. (1888). "Suite des recherches actino-électriques". Comptes Rendus. CVII: 91. (Abstract in Beibl. Ann. d. Phys. 12, 723, 1888).
Jump up ^ Stoletow, A. (1889). "Sur les phénomènes actino-électriques". Comptes Rendus. CVIII: 1241.
Jump up ^ Stoletow, A. (1889). "Актино-электрические исследовaния". Journal of the Russian Physico-chemical Society (in Russian). 21: 159.
Jump up ^ Stoletow, A. (1890). "Sur les courants actino-électriques dans l'air raréfié". Journal de Physique. 9: 468. doi:10.1051/jphystap:018900090046800.
Jump up ^ The International Year Book. (1900). New York: Dodd, Mead & Company. p. 659.
Jump up ^ Buchwald, Jed; Warwick, Andrew, eds. (2004). Histories of the Electron: The Birth of Microphysics (PDF) (illustrated, reprint ed.). MIT Press. pp. 21–23. ISBN 978-0-262-52424-7.
Jump up ^ Bloch, E. (1908). "L'ionisation de l'air par la lumière ultra-violette". Le Radium. 5 (8): 240. doi:10.1051/radium:0190800508024001.
Jump up ^ Thomson, J. J. (1907). "On the Ionisation of Gases by Ultra-Violet Light and on the evidence as to the Structure of Light afforded by its Electrical Effects". Proc. Cambr. Phil. Soc. 14: 417.
Jump up ^ Palmer, Frederic (1908). "Ionisation of Air by Ultra-violet Light". Nature. 77 (2008): 582–582. Bibcode:1908Natur..77..582P. doi:10.1038/077582b0.
Jump up ^ Palmer, Frederic (1911). "Volume Ionization Produced by Light of Extremely Short Wave-Length". Physical Review. Series I. 32: 1–22. Bibcode:1911PhRvI..32....1P. doi:10.1103/PhysRevSeriesI.32.1.
Jump up ^ "The Nobel Prize in Physics 1921". Nobel Foundation. Retrieved 2008-10-09.
Jump up ^ Lamb, Willis E.; Scully, Marlan O. (1968). "Photoelectric effect without photons, discussing classical field falling on quantized atomic electron" (PDF).
Jump up ^ Planck, Max (1901). "Ueber das Gesetz der Energieverteilung im Normalspectrum (On the Law of Distribution of Energy in the Normal Spectrum)". Annalen der Physik. 4 (3): 553. Bibcode:1901AnP...309..553P. doi:10.1002/andp.19013090310.
Jump up ^ Resnick, Robert (1972) Basic Concepts in Relativity and Early Quantum Theory, Wiley, p. 137, ISBN 0-471-71702-9.
^ Jump up to: a b Knight, Randall D. (2004) Physics for Scientists and Engineers With Modern Physics: A Strategic Approach, Pearson-Addison-Wesley, p. 1224, ISBN 0-8053-8685-8.
Jump up ^ Penrose, Roger (2005) The Road to Reality: A Complete Guide to the Laws of the Universe, Knopf, p. 502, ISBN 0-679-45443-8
Jump up ^ Resnick, Robert (1972) Basic Concepts in Relativity and Early Quantum Theory, Wiley, p. 138, ISBN 0-471-71702-9.
Jump up ^ Timothy, J. Gethyn (2010) in Huber, Martin C.E. (ed.) Observing Photons in Space, ISSI Scientific Report 009, ESA Communications, pp. 365–408, ISBN 978-92-9221-938-3
Jump up ^ Burns, R. W. (1998) Television: An International History of the Formative Years, IET, p. 358, ISBN 0-85296-914-7.
Jump up ^ Tsokos, K. A. (2010). Cambridge Physics for the IB Diploma (revised ed.). Cambridge University Press. ISBN 978-0-521-13821-5.
Jump up ^ Weaver, J. H.; Margaritondo, G. (1979). "Solid-State Photoelectron Spectroscopy with Synchrotron Radiation". Science. 206 (4415): 151–156. Bibcode:1979Sci...206..151W. PMID 17801770. doi:10.1126/science.206.4415.151.
Jump up ^ Lai, Shu T. (2011). Fundamentals of Spacecraft Charging: Spacecraft Interactions with Space Plasmas (illustrated ed.). Princeton University Press. pp. 1–6. ISBN 978-0-691-12947-1.
Jump up ^ "Spacecraft charging". Arizona State University.
Jump up ^ Bell, Trudy E., "Moon fountains", NASA.gov, 2005-03-30.
Jump up ^ Dust gets a charge in a vacuum. spacedaily.com, July 14, 2000.
Jump up ^ Evans, R. D. (1955). The Atomic Nucleus. Malabar, Fla.: Krieger. p. 673. ISBN 0-89874-414-8.
Jump up ^ Evans, R. D. (1955). The Atomic Nucleus. Malabar, Fla.: Krieger. p. 712. ISBN 0-89874-414-8.
Jump up ^ Davisson, C. M. (1965). Interaction of gamma-radiation with matter. pp. 37–78. Bibcode:1965abgs.conf...37D.
Jump up ^ Knoll, Glenn F. (1999). Radiation Detection and Measurement. New York: Wiley. p. 49. ISBN 0-471-49545-X.
External links[edit]
Wikimedia Commons has media related to Photoelectric effect.
AstronomyCast "http://www.astronomycast.com/2014/02/ep-335-photoelectric-effect/". AstronomyCast.
Nave, R., "Wave-Particle Duality". HyperPhysics.
"Photoelectric effect". Physics 2000. University of Colorado, Boulder, Colorado.
ACEPT W3 Group, "The Photoelectric Effect". Department of Physics and Astronomy, Arizona State University, Tempe, AZ.
Haberkern, Thomas, and N Deepak "Grains of Mystique: Quantum Physics for the Layman". Einstein Demystifies Photoelectric Effect, Chapter 3.
Department of Physics, "The Photoelectric effect". Physics 320 Laboratory, Davidson College, Davidson.
Fowler, Michael, "The Photoelectric Effect". Physics 252, University of Virginia.
Go to "Concerning an Heuristic Point of View Toward the Emission and Transformation of Light" to read an English translation of Einstein's 1905 paper. (Retrieved: 2014 Apr 11)
http://www.chemistryexplained.com/Ru-Sp/Solar-Cells.html
Photo-electric transducers: http://sensorse.com/page4en.html
Applets
"Photoelectric Effect". The Physics Education Technology (PhET) project. (Java)
Fendt, Walter, "The Photoelectric Effect". (Java)
"Applet: Photo Effect". Open Source Distributed Learning Content Management and Assessment System. (Java)
[show]
v
t
e
Photovoltaics
Concepts
Technology
Photovoltaics
Photoelectric effect
Solar insolation
Solar constant
Solar cell efficiency
Quantum efficiency
Nominal power (Watt-peak)
Thin-film solar cell
Multi-junction solar cell
Third-generation photovoltaic cell
Solar cell research
Thermophotovoltaic
Thermodynamic efficiency limit
Sun-free photovoltaics
Polarizing organic photovoltaics
Materials
List of semiconductor materials
Crystalline silicon (c-Si)
Polycrystalline silicon (multi-Si)
Monocrystalline silicon (mono-Si)
Cadmium telluride
Copper indium gallium selenide
Amorphous silicon (a-Si)
History
Growth of photovoltaics
Timeline of solar cells
Photovoltaic system
Solar cells
Polymer solar cell
Nanocrystal solar cell
Organic solar cell
Quantum dot solar cell
Hybrid solar cell
Plasmonic solar cell
Carbon nanotubes in photovoltaics
Dye-sensitized solar cell
Cadmium telluride photovoltaics
Copper indium gallium selenide solar cells
Printed solar panel
Perovskite solar cell
System components
Solar panel
Balance of system
Solar charge controller
Solar inverter
Solar micro-inverter
Solar cable
Photovoltaic mounting system
Maximum power point tracker
Solar tracker
Solar shingles
Solar mirror
System concepts
Perturb and observe method
Incremental conductance method
Constant voltage method
Fill factor
Concentrated photovoltaics
Photovoltaic thermal hybrid solar collector
Space-based solar power
Applications
Appliances
Solar-powered refrigerator
Solar air conditioning
Solar lamp
Solar charger
Solar backpack
Solar tree
Solar-powered pump
Solar-powered watch
Solar Tuki
Photovoltaic keyboard
Solar road stud
Solar cell phone charger
Solar notebook
Solar-powered calculator
Solar-powered fountain
Solar-powered radio
Solar-powered flashlight
Solar-powered fan
Solar street light
Solar traffic light
Land transport
Solar vehicle
Solar car
Solar roadway
Solar golf cart
The Quiet Achiever
Sunmobile
Air transport
Electric aircraft
Mauro Solar Riser
Solar panels on spacecraft
Solar-Powered Aircraft Developments Solar One
Gossamer Penguin
Qinetiq Zephyr
Solar Challenger
Water transport
Solar boat
Solar vehicle racing
Solar car racing
List of solar car teams
Solar challenges
World Solar Challenge
American Solar Challenge
Formula Sun Grand Prix
Solar Cup
Frisian Solar Challenge
Solar Splash
South African Solar Challenge
Tour de Sol
Hunt-Winston School Solar Car Challenge
Victorian Model Solar Vehicle Challenge
Generation systems
PV power station
Grid-connected photovoltaic power system
List of photovoltaic power stations
Individual projects
Alamosa photovoltaic power plant
Beneixama photovoltaic power plant
Blythe Photovoltaic Power Plant
Copper Mountain Solar Facility
Darro Solar Park
Erlasee Solar Park
Golmud Solar Park
Gottelborn Solar Park
Guadarranque solar power plant
Köthen Solar Park
Moura Photovoltaic Power Station
Olmedilla Photovoltaic Park
Pocking Solar Park
Puertollano Photovoltaic Park
Topaz Solar Farm
Wyandot Solar Facility
Building-mounted
Rooftop photovoltaic power station
Building-integrated photovoltaics
Solar Ark
Strasskirchen Solar Park
By country
Australia
Belgium
Bulgaria
Canada
Chile
China
Czech Republic
France
Germany
Greece
India
Italy
Japan
Netherlands
Romania
South Africa
Spain
Switzerland
Thailand
United Kingdom
USA
PV companies
By country
List of countries by photovoltaics production
Individual producers
First Solar
Hanwha Q CELLS
JA Solar
Motech Solar
REC
Sharp
Solar Frontier
Solyndra
Sungen Solar
Sunpower
Suntech
Trina Solar
Yingli Solar
Category
Commons
[show]
v
t
e
Energy
Fundamental concepts
Energetics
Energy
Units
Energy system
Energy transformation
Mass
Mass–energy equivalence
Power
Thermodynamics
Laws of thermodynamics
Exergy
Forms
Kinetic
Potential
Mechanical
Electric
Magnetic
Gravitational
Chemical
Ionization
Nuclear
Chromodynamic
Elastic
Mechanical wave
Sound wave
Radiant
Rest
Thermal
Energy carriers
Enthalpy
Fuel
fossil fuel
Heat
Work
Electricity
Battery
Capacitor
Primary energy
Fossil fuel
Coal
Petroleum
Natural gas
Gravitational energy
Nuclear fuel
Natural uranium
Radiant energy
Solar
Wind
Bioenergy
Hydropower
Marine energy
Geothermal
Energy system
components
Energy engineering
Oil refinery
Fossil-fuel power station
Cogeneration
Integrated gasification combined cycle
Nuclear power
Nuclear power plant
Radioisotope thermoelectric generator
Solar power
Photovoltaic system
Concentrated solar power
Solar thermal energy
Solar power tower
Solar furnace
Wind power
Wind farm
High-altitude wind power
Hydropower
Hydroelectricity
Wave farm
Tidal power
Biomass
Geothermal power
Use and
supply
Energy consumption
World energy consumption
Energy security
Energy conservation
Efficient energy use
Transport
Agriculture
Renewable energy
Sustainable energy
Energy policy
Energy development
Worldwide energy supply
South America
USA
Mexico
Canada
Europe
Asia
Africa
Australia
Misc.
Jevons's paradox
Carbon footprint
[show]
v
t
e
Albert Einstein
Physics
Special relativity
General relativity
Mass–energy equivalence (E=mc2)
Brownian motion
Photoelectric effect
Einstein coefficients
Einstein solid
Equivalence principle
Einstein field equations
Einstein radius
Einstein relation (kinetic theory)
Cosmological constant
Bose–Einstein condensate
Bose–Einstein statistics
Bose–Einstein correlations
Einstein–Cartan theory
Einstein–Infeld–Hoffmann equations
Einstein–de Haas effect
EPR paradox
Bohr–Einstein debates
Teleparallelism
Unsuccessful investigations
Works
Annus Mirabilis papers (1905)
"Investigations on the Theory of Brownian Movement" (1905)
Relativity: The Special and the General Theory (1916)
The World as I See It (1934)
"Why Socialism?" (1949)
Russell–Einstein Manifesto (1955)
Family
Pauline Koch (mother)
Hermann Einstein (father)
Maja Einstein (sister)
Mileva Marić (first wife)
Elsa Einstein (second wife)
Lieserl Einstein (daughter)
Hans Albert Einstein (son)
Eduard Einstein (son)
Bernhard Caesar Einstein (grandson)
Evelyn Einstein (granddaughter)
Thomas Martin Einstein (great-grandson)
Einstein Prizes
Albert Einstein Award
Albert Einstein Medal
Albert Einstein Peace Prize
Albert Einstein World Award of Science
Einstein Prize (APS)
Einstein Prize for Laser Science
Related
Political views
Religious views
Albert Einstein House
Einstein refrigerator
Brain
In popular culture
Einsteinium
Awards and honors
List of things named after Albert Einstein
Einstein Papers Project
Die Grundlagen der Einsteinschen Relativitäts-Theorie (1922 documentary)
The Einstein Theory of Relativity (1923 documentary)
Relics: Einstein's Brain
Genius (2017 series)
Authority control
GND: 4174487-1
NDL: 00566101
Retrieved from "https://en.wikipedia.org/w/index.php?title=Photoelectric_effect&oldid=802537241"
Categories:
Quantum mechanics
Electrical phenomena
Albert Einstein
Energy conversion
Photovoltaics
Photochemistry
Electrochemistry
Hidden categories:
CS1 Russian-language sources (ru)
Wikipedia articles needing clarification from June 2014
All articles with unsourced statements
Articles with unsourced statements from October 2009
Wikipedia articles with GND identifiers
Navigation menu
Personal tools
Not logged in
Talk
Contributions
Create account
Log in
Namespaces
Article
Talk
Variants
Views
Read
Edit
View history
More
Search
Navigation
Main page
Contents
Featured content
Current events
Random article
Donate to Wikipedia
Wikipedia store
Interaction
Help
About Wikipedia
Community portal
Recent changes
Contact page
Tools
What links here
Related changes
Upload file
Special pages
Permanent link
Page information
Wikidata item
Cite this page
Print/export
Create a book
Download as PDF
Printable version
In other projects
Wikimedia Commons
Wikiquote
Languages
العربية
অসমীয়া
Azərbaycanca
বাংলা
Беларуская
Български
Bosanski
Català
Čeština
Cymraeg
Dansk
Deutsch
Eesti
Ελληνικά
Español
Esperanto
Euskara
فارسی
Français
Gaeilge
Galego
한국어
Հայերեն
हिन्दी
Hrvatski
Bahasa Indonesia
Italiano
עברית
ಕನ್ನಡ
ქართული
Қазақша
لۊری شومالی
Latviešu
Lëtzebuergesch
Lietuvių
Magyar
Македонски
മലയാളം
मराठी
Nederlands
日本語
Norsk
Norsk nynorsk
ଓଡ଼ିଆ
ਪੰਜਾਬੀ
پنجابی
Piemontèis
Polski
Português
Română
Русский
Shqip
Simple English
Slovenčina
Slovenščina
کوردی
Српски / srpski
Srpskohrvatski / српскохрватски
Basa Sunda
Suomi
Svenska
Tagalog
தமிழ்
ไทย
Türkçe
Türkmençe
Українська
اردو
Tiếng Việt
中文
Edit links
This page was last edited on 26 September 2017, at 20:01.
Text is available under the Creative Commons Attribution-ShareAlike License; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization.
Privacy policy
About Wikipedia
Disclaimers
Contact Wikipedia
Developers
Cookie statement
Mobile view

values: mw-page-base noprint

values: mw-head-base noprint

attrs: id class style

values: firstHeading firstHeading en

values: siteSub noprint

values: jump-to-nav mw-jump

attrs: alt src width height srcset data-file-width data-file-height

values: float:right;clear:right;width:22.0em;margin:0 0 1.0em 1.0em;background:#f9f9f9;border:1px solid #aaa;padding:0.2em;border-spacing:0.4em 0;text-align:center;line-height:1.4em;font-size:88%

values:
/wiki/Planck%27s_relation
mw-redirect
Planck's relation

values: Edit section: Experimental observations of photoelectric emission

values: vertical-align: -0.671ex; width:5.297ex; height:2.509ex;

values: vertical-align: -0.838ex; width:16.47ex; height:2.676ex;

values: vertical-align: -0.338ex; width:1.349ex; height:2.176ex;

values: vertical-align: -0.671ex; width:1.289ex; height:2.509ex;

values: vertical-align: -0.838ex; width:1.531ex; height:2.176ex;

values: vertical-align: -0.338ex; width:2.446ex; height:2.176ex;

values: vertical-align: -0.671ex; width:1.396ex; height:2.509ex;

values: vertical-align: -0.838ex; width:9.245ex; height:2.676ex;

values: vertical-align: -0.671ex; width:2.211ex; height:2.509ex;

values: vertical-align: -0.838ex; width:19.368ex; height:2.843ex;

values: vertical-align: -0.671ex; width:6.609ex; height:2.509ex;

values:
/wiki/Negative_potential
mw-redirect
Negative potential

values: vertical-align: -0.671ex; width:2.427ex; height:2.509ex;

values: vertical-align: -0.671ex; width:4.481ex; height:2.509ex;

values: vertical-align: -0.671ex; width:13.544ex; height:2.509ex;

values: The text near this tag may need clarification or removal of jargon. (June 2014)

values:
noprint Inline-Template
margin-left:0.1em; white-space:nowrap;

values:
/wiki/Transition_rule
mw-redirect
Transition rule

values:
/wiki/Tight-binding_model
mw-redirect
Tight-binding model

values:
/wiki/Surface_state
mw-redirect
Surface state

values: Hüfner should likely go here, but I won't presume (October 2009)

values:
noprint Inline-Template Template-Fact
white-space:nowrap;

values:
/wiki/Alkali_metals
mw-redirect
Alkali metals

values:
/wiki/Cathode_rays
mw-redirect
Cathode rays

values:
/wiki/A._E._Becquerel
mw-redirect
A. E. Becquerel

values: Comptes rendus de l'Académie des sciences

values: This claim needs references to reliable sources. (October 2009)

values:
/wiki/Ultraviolet_light
mw-redirect
Ultraviolet light

values:
/wiki/Philipp_Eduard_Anton_von_Lenard
mw-redirect
Philipp Eduard Anton von Lenard

values:
/wiki/Wave_theory_of_light
mw-redirect
Wave theory of light

values:
/wiki/Ultraviolet_radiation
mw-redirect
Ultraviolet radiation

values:
/wiki/Lenard_effect
mw-redirect
Lenard effect

values:
/wiki/Planck%27s_constant
mw-redirect
Planck's constant

values: Edit section: Photoelectron spectroscopy

values:
/wiki/Photoelectron_spectroscopy
mw-redirect
Photoelectron spectroscopy

values:
/wiki/Electrostatic_field
mw-redirect
Electrostatic field

values:
/wiki/Micro-channel_plate
mw-redirect
Micro-channel plate

values: vertical-align: -2.171ex; width:18.671ex; height:5.676ex;

values: \sigma ={\mathrm  {constant}}\cdot {\frac  {Z^{n}}{E^{3}}}

values: display:table-cell;padding:0.2em 0.2em 0.2em 0.3em;vertical-align:middle

values: margin:0.5em 0 0.5em 1em;border:solid #aaa 1px

values: Timeline of atomic and subatomic physics

values:
nofollow
external text
//doi.org/10.1002%2Fandp.18872670827

values:
nofollow
external text
//doi.org/10.1002%2Fandp.19023130510

values:
nofollow
external text
//doi.org/10.1103%2FPhysRev.4.73.2

values:
nofollow
external text
//doi.org/10.1103%2FPhysRev.7.355

values:
/wiki/Physics_Letters_A
mw-redirect
Physics Letters A

values:
nofollow
external text
//doi.org/10.1103%2FPhysRev.23.137

values:
/wiki/Hodder_Education
mw-redirect
Hodder Education

values:
/wiki/Courier_Dover_Publications
mw-redirect
Courier Dover Publications

values:
/wiki/Springer_(publisher)
mw-redirect
Springer (publisher)

values:
nofollow
external text
//doi.org/10.1038%2F007303e0

values:
nofollow
external text
//doi.org/10.1002%2Fandp.19073280807

values:
nofollow
external text
//doi.org/10.1038%2F077582b0

values:
nofollow
external text
//doi.org/10.1103%2FPhysRevSeriesI.32.1

values:
nofollow
external text
//doi.org/10.1002%2Fandp.19013090310

values:
/wiki/PubMed_Identifier
mw-redirect
PubMed Identifier

values:
nofollow
external text
//www.ncbi.nlm.nih.gov/pubmed/17801770

values:
nofollow
external text
http://sitemaker.umich.edu/gknoll/home

values: -moz-column-width: 35em; -webkit-column-width: 35em; column-width: 35em; list-style-type: decimal;

values:
nofollow
http://www.faqs.org/docs/qp/
external text

values:
nofollow
external text
http://www.faqs.org/docs/qp/chap03.html

values:
nofollow
external free
http://sensorse.com/page4en.html

values:
row
navbox-group
width:11em;text-align: left;

values:
/wiki/Solar_insolation
mw-redirect
Solar insolation

values:
navbox-image
5
width:1px;padding:0px 0px 0px 2px

values:
/wiki/Polymer_solar_cell
mw-redirect
Polymer solar cell

values: Copper indium gallium selenide solar cells

values:
/wiki/Printed_solar_panel
mw-redirect
Printed solar panel

values:
/wiki/Solar_charge_controller
mw-redirect
Solar charge controller

values:
/wiki/Maximum_power_point_tracker
mw-redirect
Maximum power point tracker

values:
/wiki/Solar_shingles
mw-redirect
Solar shingles

values:
/wiki/Perturb_and_observe_method
mw-redirect
Perturb and observe method

values:
/wiki/Incremental_conductance_method
mw-redirect
Incremental conductance method

values:
/wiki/Constant_voltage_method
mw-redirect
Constant voltage method

values:
/wiki/Fill_factor_(solar_cell)
mw-redirect
Fill factor (solar cell)

values:
/wiki/Concentrated_photovoltaics
mw-redirect
Concentrated photovoltaics

values: Photovoltaic thermal hybrid solar collector

values:
/wiki/Solar_roadway
mw-redirect
Solar roadway

values: Solar-Powered Aircraft Developments Solar One

values:
/wiki/Gossamer_Penguin
mw-redirect
Gossamer Penguin

values:
/wiki/Solar_Challenger
mw-redirect
Solar Challenger

values:
/wiki/Solar_challenge_(disambiguation)
mw-redirect mw-disambig
Solar challenge (disambiguation)

values: Grid-connected photovoltaic power system

values:
/wiki/Gottelborn_Solar_Park
mw-redirect
Gottelborn Solar Park

values:
/wiki/Guadarranque_solar_power_plant
mw-redirect
Guadarranque solar power plant

values: List of countries by photovoltaics production

values:
/wiki/Hanwha_Q_CELLS
mw-redirect
Hanwha Q CELLS

values:
/wiki/Motech_Solar
mw-redirect
Motech Solar

values:
/wiki/Yingli_Solar
mw-redirect
Yingli Solar

attrs: alt src title width height srcset data-file-width data-file-height

values: nowraplinks hlist collapsible collapsed navbox-inner

values: navigation navbox Photovoltaics padding:3px

values:
/wiki/Electric_energy
mw-redirect
Electric energy

values:
/wiki/Chromodynamic_energy
mw-redirect
Chromodynamic energy

values:
/wiki/Rest_energy
mw-redirect
Rest energy

values:
/wiki/Wind_energy
mw-redirect
Wind energy

values:
/wiki/Fossil-fuel_power_station
mw-redirect
Fossil-fuel power station

values:
/wiki/Energy_in_Canada
mw-redirect
Energy in Canada

values:
/wiki/Jevons%27s_paradox
mw-redirect
Jevons's paradox

values: nowraplinks collapsible autocollapse navbox-inner

values: List of scientific publications by Albert Einstein

values: Über die von der molekularkinetischen Theorie der Wärme geforderte Bewegung von in ruhenden Flüssigkeiten suspendierten Teilchen

values: Relativity: The Special and the General Theory

values:
/wiki/Pauline_Koch
mw-redirect
Pauline Koch

values:
/wiki/Hermann_Einstein
mw-redirect
Hermann Einstein

values:
/wiki/Maja_Einstein
mw-redirect
Maja Einstein

values:
/wiki/Lieserl_Einstein
mw-redirect
Lieserl Einstein

values: Religious and philosophical views of Albert Einstein

values: List of things named after Albert Einstein

values: Die Grundlagen der Einsteinschen Relativitäts-Theorie

values:
nofollow
external text
http://d-nb.info/gnd/4174487-1

values: Category:CS1 Russian-language sources (ru)

values: Category:Wikipedia articles needing clarification from June 2014

values: Category:All articles with unsourced statements

values: Category:Articles with unsourced statements from October 2009

values: Category:Wikipedia articles with GND identifiers

values: Discussion about edits from this IP address [ctrl-alt-n]

values: A list of edits made from this IP address [ctrl-alt-y]

values: You are encouraged to create an account and log in; however, it is not mandatory

values: You're encouraged to log in; however, it's not mandatory. [ctrl-alt-o]

values:
/wiki/Photoelectric_effect
View the content page [ctrl-alt-c]
c

values: Discussion about the content page [ctrl-alt-t]

values: p-namespaces navigation vectorTabs p-namespaces-label

values:
p-variants
navigation
vectorMenu emptyPortlet
p-variants-label

values: Past revisions of this page [ctrl-alt-h]

values: p-views navigation vectorTabs p-views-label

values:
p-cactions
navigation
vectorMenu emptyPortlet
p-cactions-label

values:
mw-wiki-logo
/wiki/Main_Page
Visit the main page

values:
/wiki/Main_Page
Visit the main page [ctrl-alt-z]
z

values: Featured content – the best of Wikipedia

values: Find background information on current events

values:
/wiki/Special:Random
Load a random article [ctrl-alt-x]
x

values: portal navigation p-navigation p-navigation-label

values: Guidance on how to use and edit Wikipedia

values: About the project, what you can do, where to find things

values: A list of recent changes in the wiki [ctrl-alt-r]

values: portal navigation p-interaction p-interaction-label

values: List of all English Wikipedia pages containing links to this page [ctrl-alt-j]

values: Recent changes in pages linked from this page [ctrl-alt-k]

values:
/wiki/Wikipedia:File_Upload_Wizard
Upload files [ctrl-alt-u]
u

values: portal navigation p-wikibase-otherprojects p-wikibase-otherprojects-label

values:
uls-settings-trigger
Language settings
0
button
true

values: ظاهرة كهروضوئية – Arabic

values: আলোক বিদ্যুৎ পৰিঘটনা – Assamese

values: আলোক তড়িৎ ক্রিয়া – Bangla

values: Фотаэфект – Belarusian

values: Фотоелектричен ефект – Bulgarian

values:
https://et.wikipedia.org/wiki/Fotoefekt
Fotoefekt – Estonian
et
et
interlanguage-link-target

values: Φωτοηλεκτρικό φαινόμενο – Greek

values: اثر فوتوالکتریک – Persian

values: Ֆոտոէֆեկտ – Armenian

values: प्रकाश-विद्युत प्रभाव – Hindi

values: האפקט הפוטואלקטרי – Hebrew

values: ದ್ಯುತಿವಿದ್ಯುತ್ ಪರಿಣಾಮ – Kannada

values: ფოტოეფექტი – Georgian

values: Фотоэлектрлік құбылыстар – Kazakh

values: کارگرایی فوتوالکتریک – Northern Luri

values: Фотоелектричен ефект – Macedonian

values: പ്രകാശവൈദ്യുത പ്രഭാവം – Malayalam

values: प्रकाशीय विद्युत परिणाम – Marathi

values: Fotoelektrisk effekt – Norwegian Nynorsk

values: ଆଲୋକ-ବୈଦୁତିକ ପ୍ରଭାବ – Odia

values: ਫੋਟੋਇਲੈਕਟ੍ਰਿਕ ਪ੍ਰਭਾਵ – Punjabi

values: فوٹو الیکٹرک ایفیکٹ – Western Punjabi

values: Фотоэффект – Russian

values: دیاردەی کاریگەری کارۆڕووناکی – Central Kurdish

values: Фотоелектрични ефекат – Serbian

values: ஒளிமின் விளைவு – Tamil

values: ปรากฏการณ์โฟโตอิเล็กทริก – Thai

values: Фотоефект – Ukrainian

values: ضیا برقی اثر – Urdu

values: interlanguage-link interwiki-zh badge-Q17437798 badge-goodarticle

values: mediawiki ltr sitedir-ltr mw-hide-empty-elt ns-0 ns-subject page-Photoelectric_effect rootpage-Photoelectric_effect vector-nav-directionality skin-vector action-view