photoelectric cell

n. An optoelectronic device that generates an electrical output in response to incident electromagnetic radiation, such as visible light. Also called photocell, photovoltaic cell.

photoelectric cell

n (Electronics) another name for photocell

pho•to•cell

(ˈfoʊ toʊˌsɛl)

n. a solid-state electronic device that converts light into electrical energy by producing a voltage or that uses light to regulate the flow of current: used in automatic control systems for doors, burglar alarms, lighting, etc. [1890–95]

Thesaurus

Noun

photoelectric cell - a transducer used to detect and measure light and other radiationselectric eye, magic eye, photocell, photoconductive celldetector, sensing element, sensor - any device that receives a signal or stimulus (as heat or pressure or light or motion etc.) and responds to it in a distinctive mannerphotocathode - a cathode that emits electrons when illuminatedselenium cell - a photoelectric cell that uses a strip of seleniumtransducer - an electrical device that converts one form of energy into another

Translations

cellula fotoelettricafotocellula

photoelectric cell

photocell,

device whose electrical characteristics (e.g., current, voltage, or resistance) vary when light is incident upon it. The most common type consists of two electrodes separated by a light-sensitive semiconductorsemiconductor,
solid material whose electrical conductivity at room temperature is between that of a conductor and that of an insulator (see conduction; insulation). At high temperatures its conductivity approaches that of a metal, and at low temperatures it acts as an insulator.
..... Click the link for more information. material. A battery or other voltage source connected to the electrodes sets up a current even in the absence of light; when light strikes the semiconductor section of the photocell, the current in the circuit increases by an amount proportional to the intensity of the light. In the phototube, an older type of photocell, two electrodes are enclosed in a glass tube—an anode and a light-sensitive cathode, i.e., a metal that emits electrons in accordance with the photoelectric effectphotoelectric effect,
emission of electrons by substances, especially metals, when light falls on their surfaces. The effect was discovered by H. R. Hertz in 1887. The failure of the classical theory of electromagnetic radiation to explain it helped lead to the development of
..... Click the link for more information. . Although the phototube itself is now obsolete, the principle survives in the photomultiplier tube, which can be used to detect and amplify faint amounts of light. In this tube, electrons ejected from a photosensitive cathode by light are attracted toward and strike a positive electrode, liberating showers of secondary electrons; these are drawn to a more positive electrode, producing yet more secondary electrons—and so on, through several stages, until a large pulse of current is produced. Besides its use in measuring light intensity, a photomultiplier can be built into a television camera tube, making it sensitive enough to pick up the visual image of a star too faint to be seen by the human eye. The photovoltaic type of photoelectric cell, when exposed to light, can generate and support an electric current without being attached to any external voltage source. Such a cell usually consists of a semiconductor with two zones composed of dissimilar materials. When light shines on the semiconductor, a voltage is set up across the junction between the two zones. A phototransistor, which is a type of photovoltaic cell, can generate a small current that acts like the input current in a conventional transistortransistor,
three-terminal, solid-state electronic device used for amplification and switching. It is the solid-state analog to the triode electron tube; the transistor has replaced the electron tube for virtually all common applications.
..... Click the link for more information. and controls a larger current in the output circuit. Photovoltaic cells are also used to make solar batteries (see solar cellsolar cell,
semiconductor devised to convert light to electric current. It is a specially constructed diode, usually made of forms of crystalline silicon or of thin films (as of copper indium gallium selenide or amorphous silicon).
..... Click the link for more information. ). Since the current from a photocell can easily be used to operate switches or relays, it is often used in light-actuated counters, automatic door openers, and intrusion alarms. Photocells in such devices are popularly known as electric eyes.