Where results make sense

About us   |   Why use us?   |   Reviews   |   PR   |   Contact us

Energy Photovoltaics, Inc. - Company Among other positive attributes, amorphous silicon modules generate more electricity per unit of installed capacity than do crystalline silicon modules, leading to lower electricity generating costs and superior economics for many applications. EPV currently offers amorphous silicon thin film modules of several varieties based upon proprietary manufacturing technology with specially designed equipment for the production of high quality, low cost, modules. Amorphous silicon PV offers the best approach currently known to meet the growing demand for clean, renewable and affordable energy on a global basis. www.epv.net /static.asp?Page=2   (386 words)

Silicon - LoveToKnow 1911 Silicon hydride, SiH4, is obtained in an impure condition, as a spontaneously inflammable gas, by decomposing magnesium silicide with hydrochloric acid, or by the direct union of silicon and hydrogen in the electric arc. Silicon nitrogen hydride, SiNH, is a white powder formed with silicon amide when ammonia gas (diluted with hydrogen) is brought into contact with the vapour of silicon chloroform at -10° C. Trianilino silicon hydride, SiH (NHC 6 H 5) 3, is obtained by the action of aniline on a benzene solution of silicon chloroform. From the alloy containing 25% of silicon, the excess of magnesium is removed by a mixture of ethyl iodide and ether and a residue consisting of slate-blue octahedral crystals of magnesium silicide is left. www.1911encyclopedia.org /Silicon   (2378 words)

Amorphous silicon - Wikipedia, the free encyclopedia Amorphous silicon (a-Si) is the non-crystalline allotropic form of silicon. Silicon is a four-fold coordinated atom that is normally tetrahedrally bonded to four neighboring silicon atoms. Stanford R. Ovshinsky holds a number of patents in the area of amorphous semiconductor materials, semiconductors, and solar electricity generation via amorphous silicon solar cells, which are much cheaper to produce than solar cells made of crystalline silicon. en.wikipedia.org /wiki/Amorphous_silicon   (269 words)

Amorphous solid - Wikipedia, the free encyclopedia For instance, common window glass is an amorphous ceramic, many polymers (such as polystyrene) are amorphous, and even foods such as cotton candy are amorphous solids. Some amorphous metallic alloys can be prepared under special processing conditions (such as rapid solidification, thin-film deposition, or ion implantation), but the term "metallic glass" refers only to rapidly solidified materials. Amorphous solids produced by other routes, such as ion implantation and thin-film deposition are, technically speaking, not glasses. en.wikipedia.org /wiki/Amorphous_solid   (1135 words)

Amorphous silicon Silicon is normally tetrahedrally bonded to four neighboring silicon atoms. Amorphous silicon is used as the active layer in thin-film transistors (TFTs) which are most widely used in large-area electronics applications, mainly for liquid-crystal displays (LCDs). Amorphous silicon is receiving much more attention at the present time because of the potential for roll-to-roll processing, whereby circuits are literally printed onto long sheets of plastic or metal foils. www.ebroadcast.com.au /lookup/encyclopedia/am/Amorphous_silicon.html   (320 words)

Photovoltaic Materials - Amorphous Silicon Because amorphous silicon does not have the structural uniformity of crystalline or even polycrystalline silicon, the small deviations result in defects such as dangling bonds, where atoms are missing a neighbour to which they can bond. But if amorphous silicon is deposited in such a way that it contains a small amount of hydrogen (through a process called "hydrogenation"), then the hydrogen atoms combine chemically with many of the dangling bonds, essentially removing them and thereby permitting electrons to move through the amorphous silicon. Because of amorphous silicon's unique properties, the cells are designed to have an ultrathin (0.008-micron) p-type top layer; a thicker (0.5- to 1-micron) intrinsic (middle) layer; and a very thin (0.02-micron) n-type bottom layer. www.azom.com /details.asp?ArticleID=1168   (472 words)

Metal gate with CVD amorphous silicon layer for CMOS devices and method of making with a replacement gate process - ... By depositing amorphous silicon in the recess by chemical vapor deposition prior to the depositing of the metal in the recess on the amorphous silicon, the work function will be same as if the gate were made of polysilicon instead of metal. The presence of the amorphous silicon between the metal gate and the silicon substrate causes the work function to be substantially the same as the work function of a polysilicon gate on a silicon substrate. A thickness of the amorphous silicon layer 28 is between approximately 50 and approximately 500 Angstroms in certain preferred embodiments, and between approximately 50 and approximately 200 Angstroms in especially preferred embodiments. www.freepatentsonline.com /6528362.html   (2691 words)

CRCPress Periodic Table Online: Cadmium Silicon is present in the sun and stars and is a principal component of a class of meteorites known as “aerolites”. Silicon is prepared commercially by heating silica and carbon in an electric furnace, using carbon electrodes. Silicon is an important ingredient in steel; silicon carbide is one of the most important abrasives and has been used in lasers to produce coherent light of 4560 Å. chemnetbase.com /periodic_table/elements/silicon.htm   (622 words)

Technological breakthrough in silicon photonics Following a standard procedure in silicon technology, a thermally unstable silicon compound in the form of an ultra-thin layer (only two to five nanometers) is first deposited on a substrate. In a range of very few nanometers, the movement of electrons and electron vacancies in silicon is narrowly restricted, and so-called "quantum-confinement" effects appear which enlarge the band gap of silicon and shift the light emission into visible range. The luminescence of the silicon increases with the number of crystals, and the quantum efficiency of small crystals is higher than that of the larger; therefore, primarily very small crystals in high density are required for the highest possible luminenscence intensity. www.eurekalert.org /pub_releases/2003-08/m-tbi082703.php   (918 words)

Principal Metals-Silicon Silicon makes up 25.7% of the earth's crust, by weight, and is the second most abundant element, being exceeded only by oxygen. Silicon is not found free in nature, but occurs chiefly as the oxide and as silicates. Silicon is an important ingredient in steel; silicon carbide is one of the most important abrasives and has been used in lasers to produce coherent light of 4560 A. Silcones are important products of silicon. www.principalmetals.com /utilities/14.htm   (564 words)

Si - Silicon Silicon is present in the sun and stars and is a principal component of a class ofmeteorites known as aerolites. Silicon makes up 25.7% of the earth's crust, by weight, and is the second most abundantelement, being exceeded only by oxygen. Silicon is prepared commercially by heating silica and carbon in an electric furnace,using carbon electrodes. www.physlink.com /Reference/ChemicalElements/silicon.cfm   (249 words)

Amorphous Silicon Research Group   (Site not responding. Last check: 2007-09-21) Amorphous silicon is a glassy form of silicon, one of the most common elements in the Earth's crust. One possibility is that amorphous silicon, because of its special attributes of low-cost and ease of preparation, could become the mainstay of the solar cell industry. Amorphous silicon is one of the leading contenders for this role. wwwphys.murdoch.edu.au /research/photovoltaic   (384 words)

Hydrogenated amorphous silicon   (Site not responding. Last check: 2007-09-21) Amorphous silicon (a-Si) is the non-crystalline form of silicon.Silicon is normally tetrahedrally bonded to four neighboring silicon atoms.This is also the case in amorphous silicon, however, it does not form a continuous crystalline lattice as in crystalline silicon.Some atoms may actually have dangling bonds, which occur when it does not bond to four neighboring atoms. Amorphous silicon is used as the active layer in thin-film transistors (TFTs) which are most widely used in large-area electronics applications, mainlyfor liquid-crystal displays (LCDs). Amorphous silicon is receiving much moreattention at the present time because of the potential for roll-to-roll processing, whereby circuits are literally printed onto long sheets of plastic ormetal foils. www.therfcc.org /hydrogenated-amorphous-silicon-126261.html   (337 words)

Default Hydrogenated amorphous silicon cells are designed to have an ultra thin (0.008-micron) and highly doped p+ top layer; a thicker (0.5- to 1-micron) undoped intrinsic (middle) layer; and a very thin (0.02-micron) n+ bottom layer. Amorphous silicon has a band-gap energy of about 1.7 eV, which is greater than crystalline silicon's band-gap energy of 1.1 eV. After amorphous silicon modules are first exposed to light, their conversion efficiency decreases by 10% to 20%. www.sandia.gov /pv/docs/PVFSCThin-Film_Solar_Cells.htm   (2426 words)

Amorphous Silicon Arrays Find Use in NDE Enhanced X-Ray Imaging The word "amorphous" simply means that it's not crystalline, which makes it quite different from the types of silicon that you're used to hearing about. Amorphous silicon is a semiconductor, like crystalline silicon, but it is much less susceptible to degradation from exposure to radiation. The amorphous silicon serves as a platform for thin film transistors, which are the key components of each light-sensing pixel. www.spie.org /web/oer/february/feb99/fred.html   (2091 words)

silicon Silicon is an important ingredient in steel; silicon carbide is one of the most important abrasives and has been used in lasers to produce coherent light of 4560 A. Regular grade silicon (99.5%) costs about $140/kg. Unpleasant deposits of silicon dust in eyes, ears and nasal passages and injury to the skin and mucous membranes may be caused by the dust itself or by cleansing procedures used for its removal. When oxygen-containing silicon is annealed in the 450 deg C range, the -OSi= complexes become donors and contribute to electrical conductivity. www.speclab.com /elements/silicon.htm   (994 words)

Amorphous silicon solar cell - Patent 6307146 An amorphous silicon solar cell includes a substrate, a transparent electrode formed on this substrate, a power-generating film formed on this transparent electrode, and a back-side electrode formed on this power-generating film. In the amorphous silicon solar cell, the absorption coefficient to light of 500 to 700 nm having the greatest influence on the output current increases as the number of defects in the amorphous silicon film forming the i layer 6 decreases, i.e., as the number of unbonded hands of Si decreases. The plasma CVD apparatus with this construction is generally used by using a monosilane (SiH.sub.4) gas as a gas at a flow rate of 20 to 100 sccm, a pressure of 50 to 200 mTorr, an RF power of 5 to 60W, and a substrate temperature of 160 to 200.degree. www.freepatentsonline.com /6307146.html   (2138 words)

Amorphous Silicon-Based Solar Cells Come Into Their Own The 1970s energy crisis stirred interest in commercial solar power, and the discovery that amorphous silicon, laid down as a thin film using standard depositional techniques, could be used for solar cells, gave hope to the field. The original amorphous silicon solar cells had efficiencies of 1 to 2 percent, but in a short time, initial efficiencies reached 10 percent. Amorphous silicon-based solar cells are deposited on thin sheets of base material, usually glass but sometimes plastic or a metal. www.eurekalert.org /pub_releases/1997-04/PS-ASSC-030497.php   (674 words)

Amorphous solid Summary Stanford Ovshinsky pioneered the field of amorphous (disordered or structureless) materials that can be reversibly changed between amorphous and crystalline phases by an energy source, such as electricity or a laser beam. Amorphous solids are made of the same elements that produce crystalline solids, often mixed in the same ratios. Although few amorphous solids beside glasses occur naturally, an amorphous form of virtually any substance can be manufactured by sufficiently rapid quenching of the liquid phase or by depositing atoms from the vapor phase directly onto a cool substrate. www.bookrags.com /Amorphous_solid   (1920 words)

Glass - Wikipedia, the free encyclopedia The types and uses of glass for scientific and technical purposes are myriad, and range from applications involving the smallest of devices such as DNA microarrays to football field sized enormously powerful neodymium doped glass (as shown above) lasers used for laser fusion applications. Glass is generally treated as an amorphous solid rather than a liquid, though different views can be justified since characterizing glass as either 'solid' or 'liquid' is not an entirely straightforward matter [3]. In terms of molecular dynamics and thermodynamics it is possible to justify various different views that it is a highly viscous liquid, an amorphous solid, or simply that glass is another state of matter which is neither liquid nor solid. en.wikipedia.org /wiki/Glass   (4822 words)

Plasma processing in the fabrication of amorphous silicon thin-film-transistor arrays Since hydrogen preferentially etches the amorphous phase of the film [27], a higher fraction of crystalline phase was left in the high-power-deposited film. However, it is well known in the chlorine plasma etching of intrinsic silicon that the etching rate is drastically increased when a small amount of P dopant is added into the silicon [34]. Under the same halogen plasma condition, the metal etching rate is usually much lower than that of the silicon because the vapor pressure of a metal halide is lower than that of a corresponding silicon halide [41]. www.research.ibm.com /journal/rd/431/kuo.html   (6622 words)

PECVD Silicon Carbide Amorphous Silicon Carbide obtained by PECVD (a-SiC:H) Of the point of view of the obtaining technique, the main appeals of the a-SiC:H obtained by PECVD they are the low temperatures in that the material can be obtained. Those properties the most important and promising for our objective in the moment is the chemical and structural order of the material, since we are speaking about an amorphous league, in the ones which in general, the structural disorder is a serious obstacle to the obtaining of efficient electric doping. The amorphous silicon for example, became only useful as semiconductor after the discovery that atoms of hydrogen can saturate the incomplete connections in its structure, reducing like this the density of states located in the forbidden band. www.stormpages.com /aro/pagemestrado.htm   (2192 words)

Chp 5: Amorphous Silicon: The Dominant Active Matrix Technology As we indicated earlier, amorphous silicon thin-film transistors are the dominant active matrix technology, and most of the production investments have been made in amorphous silicon. Amorphous silicon is the current technology of choice for most Japanese companies because it has adequate performance as an active matrix for current TV and all current computer applications; it is produced using a low-temperature process; and it is produced using a relatively simple process requiring equipment of modest cost. One significant advance demonstrated by Hosiden is the amorphous silicon active matrix implementation of 10-inch diagonal full-color active matrix LCD using a halftone-gray scale method. www.wtec.org /loyola/dsply_jp/c5_s4.htm   (1036 words)

Nanocrystalline and amorphous silicon Intensive studies have established that these changes are due to creating of mid-gap defect states from silicon dangling bonds in the amorphous silicon films. Nanocrystalline silicon was simulated consisting of nanocrystallites embedded in an amorphous matrix. The presence of the nanocrystallite improves the ordering of the amorphous matrix which may account for the higher stability of nanocrystalline silicon towards light soaking. www.mrc.iastate.edu /research_programs/nas.htm   (538 words)

Amorphous silicon - Biocrawler   (Site not responding. Last check: 2007-09-21) This is also the case in amorphous silicon, however, it does not form a continuous crystalline lattice as in crystalline silicon. It is also considered a photovoltaic material, which can be 1/70th of the thickness of human hair. Crystalline silicon generally has better electrical properties than amorphous silicon, but in recent years researchers in the field have been able to close the gap somewhat. www.biocrawler.com /encyclopedia/Amorphous_silicon   (391 words)

[No title]   (Site not responding. Last check: 2007-09-21) Background Conventional hydrogenated amorphous silicon devices cannot detect high-energy particles, as the particle energies are too large and they travel through the amorphous silicon with very little loss in their energy. Increasing the thickness of the amorphous silicon layer is one possible solution, but these structures are not feasible due to the complicated fabrication and the extremely high voltages required for operation that exceed the breakdown voltages of the sensing devices. As amorphous silicon radiation sensors are most efficient in the visible light range, the down converting of the high-energy particles to within that range is extremely important for efficient operation. www.eecs.umich.edu /~jpotkay/docs/eecs512_final.doc   (7642 words)

types The most common multi-junction device is a multi-junction amorphous silicon, which has some of the best performance in all light conditions. The only disadvantage is that the power drops off more (compared to multi-junction amorphous silicon) in partially sunny conditions. Amorphous Silicon (especially multi-junction amorphous silicon) is better when you can’t count on 100% sunny applications, but a multi-junction solution like CIGS can create a more compact solution in full sun, due to its increased photovoltaic efficiencies. www.thesolarpowerstore.com /types.html   (588 words)

Try your search on: Qwika (all wikis)

About us   |   Why use us?   |   Reviews   |   Press   |   Contact us   Copyright © 2005-2007 www.factbites.com Usage implies agreement with terms.