Zinc Oxide

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  • Topic: Ultraviolet, Zinc oxide, Titanium dioxide
  • Pages : 2 (409 words )
  • Download(s) : 146
  • Published : October 21, 2006
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Zinc oxide in a mixture with a about 0.5% iron(III) oxide (Fe2O3) is called calamine and is used in calamine lotion. There are also two minerals, smithsonite and hemimorphite, which have been called calamine historically (see: calamine (mineral).

Zinc peroxide, ZnO2 .½ H2O, is a white to yellow powder that is used in antiseptic ointments.

Zinc white is used as a pigment in paints and is more opaque than lithopone, but less opaque than titanium dioxide. It is also used in coatings for paper. Chinese white is a special grade of zinc white used in artists' pigments. Because it reflects both UVA and UVB rays of ultraviolet light, zinc oxide can be used in ointments, creams, and lotions to protect against sunburn and other damage to the skin caused by ultraviolet light (see sunscreen).

Zinc oxide and stearic acid are important ingredients in the commercial manufacture of rubber goods. A proper mixture of these two compounds allows a quicker and more controllable rubber cure. Zinc oxide can also be used as a filler in some rubber mixtures.

Zinc oxide is a semiconductor with a direct band gap of 3.2 eV (387 nm, deep violet/borderline UV). A common application is in gas sensors. As of 2003, it has been utilized in recent research to build blue LEDs and transparent TFTs.

N-type doped films are often used in thin film technology, where zinc oxide serves as a TCO (transparent conducting oxide). N-type doping is possible by introduction of hydrogen or zinc interstitial defects. Oxygen vacancies are no longer considered to contribute to the n-type conductivity because these levels are too deep in the band gap. P-type doping is difficult and is currently an active area of research. Thin-film solar cells, LCD and flat panel displays are typical applications of this material. Zinc oxide is transparent and conductive, and can therefore be used as a transparent electrode. Indium tin oxide (ITO) is another transparent conducting oxide often used in microelectronics....
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