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The photoelectric effect is the emission of electrons from a material caused by electromagnetic radiation such as ultraviolet light. Electrons emitted in this manner are called photoelectrons. The phenomenon is studied in condensed matter physics, solid state, and quantum chemistry to draw inferences about the properties of atoms, molecules and ...
Classical optics long preceded the discovery that light is quantized, when Albert Einstein famously explained the photoelectric effect in 1905. Optics tools include the refracting lens, the reflecting mirror, and various optical components and instruments developed throughout the 15th to 19th centuries.
The photoelectric effect was further evidence of this quantization as explained by Albert Einstein in a 1905 paper, a discovery for which he was to be awarded the Nobel Prize in 1921. Niels Bohr showed that the hypothesis of optical radiation being quantized corresponded to his theory of the quantized energy levels of atoms , and the spectrum ...
This formula defines the photoelectric effect. Not every photon which encounters an atom or ion will photoionize it. The probability of photoionization is related to the photoionization cross-section, which depends on the energy of the photon and the target being considered. For photon energies below the ionization threshold, the ...
Einstein's photon had an energy proportional to its frequency and also explained an unpublished law of Stokes and the photoelectric effect. [5] This published postulate was specifically cited by the Nobel Prize in Physics committee in their decision to award the prize for 1921 to Einstein.
Photoelectric effect Schematic illustration of the photoemission process. Using Einstein's method, the following equations are used: energy of photon = energy needed to remove an electron + kinetic energy of the emitted electron = + where h is the Planck constant;
A phototube or photoelectric cell is a type of gas-filled or vacuum tube that is sensitive to light. Such a tube is more correctly called a 'photoemissive cell' to distinguish it from photovoltaic or photoconductive cells. Phototubes were previously more widely used but are now replaced in many applications by solid state photodetectors.
Photocurrent is the electric current through a photosensitive device, such as a photodiode, as the result of exposure to radiant power.The photocurrent may occur as a result of the photoelectric, photoemissive, or photovoltaic effect.