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Silicon. face-centered diamond-cubic (cF8) Silicon is a chemical element; it has symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic luster, and is a tetravalent metalloid and semiconductor. It is a member of group 14 in the periodic table: carbon is above it; and germanium, tin, lead, and flerovium ...
A sponge-like porous form of silicon (p-Si) is typically prepared by the electrochemical etching of silicon wafers in a hydrofluoric acid solution. [152] Flakes of p-Si sometimes appear red; [153] it has a band gap of 1.97–2.1 eV. [154] The many tiny pores in porous silicon give it an enormous internal surface area, up to 1,000 m 2 /cm 3. [155]
As a metalloid the chemistry of silicon is largely covalent in nature, noting it can form alloys with metals such as iron and copper. The common oxide of silicon (SiO 2) is weakly acidic. Germanium. Germanium is a shiny, mostly unreactive grey-white solid with a density of 5.323 g/cm 3 (about two-thirds that of iron), and is hard (MH 6.0) and ...
In the context of the periodic table a nonmetal is a chemical element that mostly lacks distinctive metallic properties. They range from colorless gases like hydrogen to shiny crystals like iodine. Physically, they are usually lighter (less dense) than elements that form metals and are often poor conductors of heat and electricity.
Silicon compounds are compounds containing the element silicon (Si). As a carbon group element, silicon often forms compounds in the +4 oxidation state, though many unusual compounds have been discovered that differ from expectations based on its valence electrons, including the silicides and some silanes. Metal silicides, silicon halides, and ...
The conductivity of silicon is increased by adding a small amount (of the order of 1 in 10 8) of pentavalent (antimony, phosphorus, or arsenic) or trivalent (boron, gallium, indium) atoms. [3] This process is known as doping, and the resulting semiconductors are known as doped or extrinsic semiconductors. Apart from doping, the conductivity of ...
The bonding between adjacent atoms in a chain is covalent, but there is evidence of a weak metallic interaction between the neighbouring atoms of different chains. [387] Tellurium is a semiconductor with an electrical conductivity of around 1.0 S•cm −1 [ 388 ] and a band gap of 0.32 to 0.38 eV. [ 389 ]
The primary application of monocrystalline silicon is in the production of discrete components and integrated circuits.Ingots made by the Czochralski method are sliced into wafers about 0.75 mm thick and polished to obtain a regular, flat substrate, onto which microelectronic devices are built through various microfabrication processes, such as doping or ion implantation, etching, deposition ...