The relationship between silicon metal, monocrystalline silicon and polysilicon
The raw materials of smelting metallic silicon are mainly silica, carbonaceous reductant. Produce silicon metal choose the carbonaceous reducing principle is: high fixed carbon, low ash, chemical activity.
Usually low ash petroleum coke or bitumen Jiaozuo reductant. However, due to both coke resistivity response capability, and thus must be equipped with low ash resistivity and reaction ability of charcoal instead of part of petroleum coke. For the charge sintering, should fit into the part of low ash bituminous coal. It must be pointed out, too much or all with charcoal, will not only increase the cost of the product, but also make the furnace conditions disorders, as a result of the material surface sintering difference caused thorn fire collapsed material is difficult to form a high-temperature reaction zone, easy open into the silicon carbide hearth layer, the iron difficulties. Semiconductor silicon is used for fabricating a semiconductor device of high purity silicon metal. Flue byproducts produced in the smelting of silicon metal, silicon powder, silica fume, is widely used in building concrete industry and refractory industry.
Monocrystalline silicon which does not contain the silicon crystal of the large angle grain boundary or a twin boundary. Single crystals of silicon. A lattice structure having a substantially complete crystal. With different nature in different directions, it is a good semi-conductive material. The purity requirements of 99.9999%, and even more than 99.9999999%. For the manufacture of semiconductor devices, solar batteries, etc.. Drawn from high purity polysilicon monocrystalline furnace. Monocrystalline silicon is the raw material for manufacturing a semiconductor silicon device, the system for power rectifiers, power transistors, diodes, and switching device. In the development of energy resources is a promising material. The silicon single crystal manufacturing method is typically the first polysilicon or amorphous silicon, monocrystalline silicon rod is grown from the melt and then with the Czochralski method or the floating zone melting method.
As the surveys by metal powder supplier, Monocrystalline silicon having the physical properties of the metal, have a weak conductive, its conductivity increases with the temperature increasing, have semiconductive significant. Ultrapure single crystal silicon is intrinsic semiconductor. b A family incorporated in ultrapure monocrystalline Trace elements such as boron can be increased to the extent of conductive and forming a p-type silicon semiconductor; d A family such as the incorporation of trace amounts of elements, such as phosphorus or arsenic may also improve the conductivity level, formation of n-type silicon semiconductor. The silicon single crystal manufacturing method is typically the first polysilicon or amorphous silicon, monocrystalline silicon rod is grown from the melt and then with the Czochralski method or the floating zone melting method. Monocrystalline silicon is mainly used for the production of semiconductor elements.
Polysilicon is not the same by a large number of crystallographic direction of silicon single crystal composed of silicon crystal. Polysilicon, is a form of elemental silicon. Solidification of the molten elemental silicon under subcooled conditions, silicon atoms are arranged in diamond lattice patterns in many nuclei, such as these nuclei grow into crystal plane orientation of different grains, these grains combine to crystallize into polysilicon. Use value: it can be seen from the development process of the international solar cell development trend for monocrystalline silicon, polycrystalline silicon, ribbon silicon, and thin-film materials (including microcrystalline silicon thin-film compound base film and dye film).
Polysilicon can be used for the raw materials of pulling single crystal silicon, differences between single crystal silicon and polycrystalline silicon and monocrystalline silicon mainly in physical properties. For example, in anisotropy of mechanical properties, optical properties and thermal properties, it is far less the monocrystalline obvious; polysilicon crystal conductive monocrystalline also far less significant in electrical properties, and even almost no conductivity. Polysilicon is the direct production of silicon feedstock, is the foundation of contemporary artificial intelligence, automatic control, information processing, and photoelectric conversion semiconductor devices, electronic information material. Be referred to as "the cornerstone of Microelectronics Building.
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