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What is the use of selenium photocells?
Because of its photovoltaic and photoconductive properties, selenium is used in photocopying, photocells, light meters and solar cells. Its use as a photoconductor in plain-paper copiers once was a leading application but in the 1980s, the photoconductor application declined (although it was still a large end-use) as more and more copiers switched to the use of organic photoconductors. It was once widely used in selenium rectifiers.
What type of element is selenium?
Selenium exists in several allotropic forms. The most stable, crystalline hexagonal selenium, is metallic gray. Crystalline mono clinic selenium is a deep red color. Amorphous selenium is red in powder form and is black in vitreous form. Gray crystalline 'metallic' selenium conducts electricity better in the light than in the dark (photoconductive) and it can convert light directly into electricity (photovoltaic).
What does a photocell do?
Photocell consists of two special pieces of silicon joined together. Pure silicon is neaturally charged but if small amount of an impurity such as phosphurus is added, ther are more free electron which make this a better conductor than pure silicon. This is known as n-type(negative) silicon. If a diffrent impurity, such as boron, is added there is an absence of free elactron. The absence of an elactron is known as a hole and the silicon is knpwn as p-type silicon. When these two types of silicon are placed together it is called a p-n junction. An electric field is created between the two layers. Sunlight is made up of a tiny packets of energy called photons. When photons are absorbed the energy causes electron to become free. They move to the negetive layer and leave the junction to flow in an external curcuit.
What are photoconductive cells?
The photoconductive cell is a two terminal semiconductor device whose terminal reistance varies linearly with the intensity of incident light .
Mention the different types of photoelectric cells?
there are three types ,they are photoconductive cell ,photoemissive cell and photovoltiac cell
What has the author William George Williams written?
William George Williams has written: 'The hole mobility and photoconductive properties of rubrene'
What has the author Eugene Paul Steinmetz written?
Eugene Paul Steinmetz has written: 'The minority carrier lifetimes in germanium and silicon semiconductors by the methods of photoconductive-decay' -- subject(s): Semiconductors
What does a photoresistor do?
What does a photoresistor do ?Photoresistors (also often called phototransistorsor CdS photoconductive photocells; use 'photocell' for digikey) are simple resistors that altar resistancedepending on the amount of light place over them.
What are some selenium uses?
Some applications of selenium:- red glass fabrication- rubber vulcanization- manganese refinning by electrolysis- component of alloys- solar cells- photoconductive materials- inorganic dyes
What has the author J R Houck written?
J. R Houck has written: 'Long wavelength photoconductive detectors for airborne and orbital infrared astronomy' -- subject(s): Infrared astronomy, Photoconductivity
What are photo conductive polymers?
photoconductive polymers are materials that change their electrical conductivity when subject to light (infra red- visible - ultraviolet - gamma). They are mainly used in photocopiers and holography.
What is the definition of a photocell?
A solid-state device that converts light into electrical energy byproducing a voltage, as in a photovoltaic cell, or uses light toregulate the flow of current, as in a photoconductive cell: used inautomatic control systems for doors, lighting, etc. By smarty
What is the use of selenium photocells?
Because of its photovoltaic and photoconductive properties, selenium is used in photocopying, photocells, light meters and solar cells. Its use as a photoconductor in plain-paper copiers once was a leading application but in the 1980s, the photoconductor application declined (although it was still a large end-use) as more and more copiers switched to the use of organic photoconductors. It was once widely used in selenium rectifiers.
What type of technology is used for a Xerox machine?
Xerography, a form of photography using electrostatic toner transfer. A photoconductive drum is first electrostatically charged, then it is exposed to the light of the image which removes the electrostatic charge only in the illuminated areas, then the toner powder is applied to the drum and sticks to the areas that are still electrostatically charged, then the toner powder is transferred off the drum to a sheet of paper by another electrostatic charge. The paper carrying the toner powder then passes through an "oven" which melts the toner bonding it to the paper.
What type of element is selenium?
Selenium exists in several allotropic forms. The most stable, crystalline hexagonal selenium, is metallic gray. Crystalline mono clinic selenium is a deep red color. Amorphous selenium is red in powder form and is black in vitreous form. Gray crystalline 'metallic' selenium conducts electricity better in the light than in the dark (photoconductive) and it can convert light directly into electricity (photovoltaic).
