Selenium ruby

Selenium photovoltaic cell, 22 100, 103 Selenium pink glass, 22 97 Selenium rectifiers, 22 99-100 Selenium ruby glass, 22 96-97 Selenium sulfide... 

Signal traffic lights make use of red-coloured glasses (selenium ruby), green (Cu + -I- Cr " ), yellow (amber) and blue (Cu " + Co ). 

In a CdS-doped glass, adding more Se can result in Selenium Ruby. The details of all these colorings will depend on just what glass batch is used and the firing conditions. 

Cadmium Selenide. This compound, or the polyselenide, is responsible for the colour in selenium ruby glass. With some CdS in solid solution it forms the basis of Cd-Se red ceramic (especially vitreous enamel) colours the firing temperature must not exceed about 850°C. The presence of up to 3% V2O5 is claimed to stabilize the colour, blackening in the presence of a glaze or flux containing Pb is caused by the formation of PbSe. Cadmium Silicate. CdSi03, sp. gr. 4.9 m.p. 1240°C. 

Selenium is used in Xerography for reproducing and copying documents, letters, etc. It is used by the glass industry to decolorize glass and to make ruby-colored glasses and enamels. It is also used as a photographic toner, and as an additive to stainless steel. 

The photosensitive nature of selenium makes it useful in devices that respond to the intensity of light, such as photocells, light meters for cameras, xerography, and electric eyes. Selenium also has the ability to produce electricity directly from sunlight, making it ideal for use in solar cells. Selenium possesses semiconductor properties that make it useful in the electronics industry, where it is a component in some types of solid-state electronics and rectifiers. It is also used in the production of ruby-red glass and enamels and as an additive to improve the quality of steel and copper. Additionally, it is a catalyst (to speed up chemical reactions) in the manufacture of rubber. 

Sulfur-selenium phases can be prepared by cooling molten mixtures of the elements either slowly or by quenching followed by extraction with carbon disulfide, carbon tetrachloride or benzene. The crystals are obtained upon evaporation or cooling of the resulting solutions. Their colour deepens from yellow to ruby red with increasing selenium content In the older literature there has been some confusion whether to consider these phases as mixed crystals of discrete Sg and SCg molecules or as binary compounds containing SeS bonds. 

Phosphorus Triselenide or Phosphorous Selenide, P2Se3.— This compound may be obtained by heating together phosphorus and selenium in the requisite atomic proportions. The reaction is accompanied by a great evolution of heat. The product is a ruby-red solid, which is combustible on heating. It is insoluble in carbon disulphide. With metal selenides it forms double selenides of the typeP2Se3.2MSe.2... 

Selenium is also used to impart a ruby-red color to glass, and to neutralize the green color in glass which is due to the presence of iron. 

Selenium. Compounds of Se are used for decolourising glass in the tank-melting process under other conditions this element will produce red coloured glass (see RUBY glass), pottery, or vitreous enamel. 

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