Silicon is one of the most widely used elements, it is important to plant and animal life. Silica is found in plant ashes and in the human skeleton. Silicon is an important ingredient in steel. Silicon mixed with gallium, arsenic, boron, etc. is used to produce transistors, solar cells, rectifiers, and other important solid-state electronic devices. Silicones range from liquids to hard solids and have many useful properties, including use as adhesives, sealants, and insulators. Sand and clay, which have silicon in them, are used to make building materials. Silica is used to make glass, which has many useful mechanical, electrical, optical, and thermal properties.
Silicon makes up 25.7% of the earth's crust, by weight, making it the second most abundant element (exceeded by oxygen). Silicon is found in the sun and stars. Silicon is not found free in nature. It commonly occurs as the oxide and silicates, including sand, quartz, amethyst, agate, flint, jasper, opal, and citrine. Silicate minerals include granite, hornblende, feldspar, mica, clay, and asbestos. Silicon crystallizes in a diamond cubic crystal structure.
Metallurgical grade silicon crystal is produced by carbothermic reduction of quartz in melting plants in the metallurgical industry, the tops and bottoms contain small amounts of impurities and dislocations and are therefore cut off. This cut-off and polysilicon which is not pure enough for the electronic industry goes to the solar industry, and up to about 2002, this was enough to cover the material need for the solar cell industry. After 2002, however, the demand surpassed the supply. This has lead to a silicon shortage and a price increase. In the Siemens process, silgrain (>99.6 % purity) is used. Silgrain is then reacted with hydrochloric acid in the presence of a copper catalyst. The main product obtained is trichlorosilane (SiHCl3), which is
the century, the region of Northern California we call Silicon Valley, was known as the Valley of Heart's Delight. At that time it was better known for its apricots and walnuts than for its cutting-edge technology. The first time the term Silicon Valley was used, was in 1971 when a journalist wrote a couple of articles in Electronic News, a weekly electronic industry tabloid, about the semiconductor-industry around Palo Alto, California. Silicon Valley has since then transformed into a region filled…
GROUP WORK: Kerby, Ritesh, Prasangi, Rachel, Roland, Kat, Floran. #1. Allocation of funds according to the type of investment we plan which will total to $25K As a group, we have decided to allocate $25,000 investment funds in the below mentioned percentage output. High risk - We will invest in Stocks 52 % of our total Investment, which will be $13000 a. Exxon Mobil - 44% which is $5720 b. DaVita - 24% which is $3120 c. Qualcomm - 32% which is $4160 Medium /…
REACTION PAPER “PIRATES OF THE SILICON VALLEY” When announced that we're going to watch a movie about computer evolution, I was like "oh no! for sure this will serve as my sleeping pill for today". But as the story goes, it is very interesting, very inspiring that makes me want to know more about Bill Gates and Steve Jobs. The movie Pirates of Silicon Valley is a film based on the book "Fire in the Valley: The Making of the Personal Computer" by Paul Freiberger. The movie took off w/ Steve…
crystal silicon ingots are produced with a crystal pulling process called the CZ (Czochralski) method. Crushed high-purity polycrystalline silicon is doped with elements like boron or phosphorous and melted at 1400° in a quartz crucible surrounded by an inert gas atmosphere of highpurity argon. The melt is cooled to a precise temperature, then a "seed" of single crystal silicon is placed into the melt and slowly rotated as it is "pulled" out. Page 6 Ingot Characterization Single crystal silicon ingots…
Mono-crystalline cells are obtained from pseudo-square silicon wafers, substrates cut from boules grown by the Czochralski process, the float-zone method, ribbon growth, or other emerging methods. Multi-crystalline silicon solar cells are traditionally made from square silicon substrates cut from ingots cast in quartz crucibles Crystalline silicon cells are made from thin slices cut from a single crystal of silicon (mono-crystalline) or from a block of silicon crystals (polycrystalline). Now a days the CST…
and holes decrease, and the number of holes and electrons increase exponentially. Therefore their will be more for the current to flow through meaning it will have higher conductivity. Silicon is a semiconductor and its electron configuration is 1s2 2s2 2p6 3s2 3p2 , so in the outer most electron configuration silicon have 2 electrons filling the p band. And because it is a semiconductor it will have the properties, therefore as temperature increases the conductivity will too. [2 marks for each part]…
usually made of doped silicon or in some circumstances germanium. Pure silicon is referred to as almost an insulator, very little electricity will flow through it. This is why silicon is 'doped' to change its properties. To dope silicon you need to mix it with impurities, there are two types of this doping. The first type is the 'N-type'. In this type of doping arsenic or phosphorus is added to the silicon. These elements are used as they have five outer electrons. Silicon has four outer electrons…
Analogue location drives digital innovation: the importance of local connections Silicon Valley. This name conjures up brand associations like high tech, digital, Facebook, Google, venture capitalism, Stanford, Palo Alto, Cupertino, Infinite Loop, Linkedin, Cisco, cloud, Big Data, Xerox PARC. But think about the name in two parts. a. Silicon. The raw material for most commercial semiconductors, the backbone of the digital world. b. Valley. A physical description of a geological depression with…
Solar panel cells traditionally contained silicon crystals because when hit with light energy, the electrons would move around instead of just vibrating from side to side to create heat (3). Bonds between silicon atoms in a crystal are held together by electrons shared among all of the atoms in the crystal (3). A silicon crystal resembles the structure of a diamond crystal (5). Both create a network solid when bonded to themselves (silicon bonded to silicon or carbon bonded to carbon) (5). This means that the solid is hard…
Anthony Moore SGI versus Dell: Competition In Server and Cloud Computing I. The History, Development, and Growth Rackable Systems was founded in 1999 by Mark Barrenechea in Milpitas Silicon Valley, California, as a specialist server company. Rackable had achieved much success until late 2006 when much larger companies, such as IBM, HP and Dell, began a price competition, driving down cost and Rackable Systems profit margins as well. During the 2000’s Rackable changed business strategies…
