ABOUT
Selenium is a chemical element with symbol Se and atomic number 34.
PROPERTIES
Exists in two forms: a silvery metal or a powder.
Red selenium is an amorphous, glass-like solid, whereas grey selenium is a soft, bluish-grey metal.
Grey selenium is a semi-conductor. Its electrical conductivity increases on exposure to light, reverting to its normal value in darkness.
APPLICATIONS
Together with cadmium and sulphur, selenium is a component of pigments used in plastic colouring.
In pigments used in Paint, enamels, ink and rubber
Zinc selenide is also used in windows for infrared optical devices.
Selenium can be found in new CIGS photovoltaic technologies (cadmium indium gallium selenide)
Solid state memory in electronic applications.
Selenium is an essential micronutrient for animal
It is also used to make photographic toner, photo cells, electric eyes and light meters for cameras.
Selenium is used with bismuth in brasses and as an additive to stainless steel. When selenium is added to iron and copper based metals it improves their machinability.
Red Pigments
Light-sensitive materials, glass colorants/decolorants, pigments, CIGS solar cells, X-ray detector
It is therefore useful in photocells, solar cells and photocopiers. It can also convert AC
SUBSTITUTES
Silicon is the major substitute for selenium in low- and medium-voltage rectifiers. Organic pigments
have been developed as substitutes for cadmium sulfoselenide pigments. Other substitutes include cerium oxide as
either a colorant or decolorant in glass; tellurium in pigments and rubber; bismuth, lead, and tellurium in freemachining
alloys; and bismuth and tellurium in lead-free brasses. Sulfur dioxide can be used as a replacement for
selenium dioxide in the production of electrolytic manganese metal, but it is not as energy efficient.
The selenium-tellurium photoreceptors used in some plain paper copiers and laser printers have been replaced by
organic photoreceptors in newer machines. Amorphous silicon and cadmium telluride are the two principal
competitors with CIGS in thin-film photovoltaic solar cells