|
Gallium Antimonide
Gallium antimonide (GaSb) is a semiconducting compound of gallium and antimony of the III-V family. It has a lattice constant of about 0.61 nm. It has a band gap of 0.67 eV. History The intermetallic compound GaSb was first prepared in 1926 by Victor Goldschmidt, who directly combined the elements under an inert gas atmosphere and reported on GaSb's lattice constant, which has since been revised. Goldschmidt also synthesized gallium phosphide and gallium arsenide. The Ga-Sb phase equilibria was investigated in 1955 by Koster and by Greenfield.Greenfield, I. G.; Smith, R. L., ''Trans. AIME'' 203, 351 (1955). Applications GaSb can be used for Infrared detectors, infrared LEDs and lasers and transistors, and thermophotovoltaic systems. See also * Aluminium antimonide * Indium antimonide * Gallium arsenide References External links properties listed at NSM Ioffe Institute. National Compound Semiconductor Roadmapat the Office of Naval Research The Office of Naval Research (ONR ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphalerite
Sphalerite (sometimes spelled sphaelerite) is a sulfide mineral with the chemical formula . It is the most important ore of zinc. Sphalerite is found in a variety of deposit types, but it is primarily in Sedimentary exhalative deposits, sedimentary exhalative, Carbonate-hosted lead-zinc ore deposits, Mississippi-Valley type, and Volcanogenic massive sulfide ore deposit, volcanogenic massive sulfide deposits. It is found in association with galena, chalcopyrite, pyrite (and other sulfide mineral, sulfides), calcite, dolomite (mineral), dolomite, quartz, rhodochrosite, and fluorite. German geologist Ernst Friedrich Glocker discovered sphalerite in 1847, naming it based on the Greek word ''sphaleros'', meaning "deceiving", due to the difficulty of identifying the mineral. In addition to zinc, sphalerite is an ore of cadmium, gallium, germanium, and indium. Miners have been known to refer to sphalerite as ''zinc blende'', ''black-jack'', and ''ruby blende''. Marmatite is an opaque ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infrared Detector
An infrared detector is a detector that reacts to infrared (IR) radiation. The two main types of detectors are thermal and photonic (photodetectors). The thermal effects of the incident IR radiation can be followed through many temperature dependent phenomena. Bolometers and microbolometers are based on changes in resistance. Thermocouples and thermopiles use the thermoelectric effect. Golay cells follow thermal expansion. In IR spectrometers the pyroelectric detectors are the most widespread. The response time and sensitivity of photonic detectors can be much higher, but usually these have to be cooled to cut thermal noise. The materials in these are semiconductors with narrow band gaps. Incident IR photons can cause electronic excitations. In photoconductive detectors, the resistivity of the detector element is monitored. Photovoltaic detectors contain a p-n junction on which photoelectric current appears upon illumination. An infrared detector is hybridized by connecting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antimonides
Antimonides (sometimes called stibnides) are Chemical compound, compounds of antimony with more electropositive elements. The antimonide ion is Sb3−. Reduction of antimony by alkali metals or by other methods leads to alkali metal antimonides of various types. Known antimonides include isolated Sb3− ions (in Li3Sb, Na3Sb), dumbbells Sb24− in Cs4Sb2, discrete antimony chains, for example, Sb68− in SrSb3, infinite spirals (Sb−)n (in NaSb, RbSb), planar four-membered rings Sb42−, Sb73− cages in Cs3Sb, and net shaped anions Sb32− in BaSb3. Some antimonides are semiconductors, e.g. those of the boron group such as indium antimonide. Many antimonides are flammable or decomposed by oxygen when heated since the antimonide ion is a reducing agent. References See also * Antimonide mineral Anions Antimonides {{inorganic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gallium Compounds
Gallium compounds compounds containing the element gallium. These compounds are found primarily in the +3 oxidation state. The +1 oxidation state is also found in some compounds, although it is less common than it is for gallium's heavier congeners indium and thallium. For example, the very stable GaCl2 contains both gallium(I) and gallium(III) and can be formulated as GaIGaIIICl4; in contrast, the monochloride is unstable above 0 °C, disproportionating into elemental gallium and gallium(III) chloride. Compounds containing Ga–Ga bonds are true gallium(II) compounds, such as GaS (which can be formulated as Ga24+(S2−)2) and the dioxan complex Ga2Cl4(C4H8O2)2.Greenwood and Earnshaw, p. 240 Aqueous chemistry Strong acids dissolve gallium, forming gallium(III) salts such as (gallium nitrate). Aqueous solutions of gallium(III) salts contain the hydrated gallium ion, . Gallium(III) hydroxide, , may be precipitated from gallium(III) solutions by adding ammonia. Dehydrating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
III-V Semiconductors
Semiconductor materials are nominally small band gap insulators. The defining property of a semiconductor material is that it can be compromised by doping it with impurities that alter its electronic properties in a controllable way. Because of their application in the computer and photovoltaic industry—in devices such as transistors, lasers, and solar cells—the search for new semiconductor materials and the improvement of existing materials is an important field of study in materials science. Most commonly used semiconductor materials are crystalline inorganic solids. These materials are classified according to the periodic table groups of their constituent atoms. Different semiconductor materials differ in their properties. Thus, in comparison with silicon, compound semiconductors have both advantages and disadvantages. For example, gallium arsenide (GaAs) has six times higher electron mobility than silicon, which allows faster operation; wider band gap, which allo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Office Of Naval Research
The Office of Naval Research (ONR) is an organization within the United States Department of the Navy responsible for the science and technology programs of the U.S. Navy and Marine Corps. Established by Congress in 1946, its mission is to plan, foster, and encourage scientific research to maintain future naval power and preserve national security. It carries this out through funding and collaboration with schools, universities, government laboratories, nonprofit organizations, and for-profit organizations, and overseeing the Naval Research Laboratory, the corporate research laboratory for the Navy and Marine Corps. NRL conducts a broad program of scientific research, technology and advanced development. ONR Headquarters is in the Ballston neighborhood of Arlington, Virginia. ONR Global has offices overseas in Santiago, Sao Paulo, London, Prague, Singapore, and Tokyo. Overview ONR was authorized by an Act of Congress, Public Law 588, and subsequently approved by President ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indium Antimonide
Indium antimonide (InSb) is a crystalline compound made from the elements indium (In) and antimony (Sb). It is a narrow- gap semiconductor material from the III- V group used in infrared detectors, including thermal imaging cameras, FLIR systems, infrared homing missile guidance systems, and in infrared astronomy. The indium antimonide detectors are sensitive between 1–5 μm wavelengths. Indium antimonide was a very common detector in the old, single-detector mechanically scanned thermal imaging systems. Another application is as a terahertz radiation source as it is a strong photo-Dember emitter. History The intermetallic compound was first reported by Liu and Peretti in 1951, who gave its homogeneity range, structure type, and lattice constant. Polycrystalline ingots of InSb were prepared by Heinrich Welker in 1952, although they were not very pure by today's semiconductor standards. Welker was interested in systematically studying the semiconducting properties of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aluminium Antimonide
Aluminium antimonide (AlSb) is a semiconductor of the group III-V family containing aluminium and antimony. The lattice constant is 0.61 nm. The indirect bandgap is approximately 1.6 electron volt, eV at 300 K, whereas the direct band gap is 2.22 eV. Its electron mobility is 200 cm²·V−1·s−1 and hole mobility 400 cm²·V−1·s−1 at 300 K. Its refractive index is 3.3 at a wavelength of 2 μm, and its dielectric constant is 10.9 at microwave frequencies.K Seeger and E Schonherr "Microwave dielectric constant of aluminium antimonide" Semicond. Sci. Technol. 6 (1991) 301 AlSb can be chemical reaction, reacted with other III-V materials to produce ternary materials including aluminium indium antimonide, AlInSb, AlGaSb and AlAsSb. Aluminum antimonide is rather flammable because of the reducing tendency of the antimonide (Sb3−) ion. It burns to produce aluminum oxide and antimony trioxide. See also * Gallium antimonide * Indium antimonide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermophotovoltaic
Thermophotovoltaic (TPV) energy conversion is a direct conversion process from heat to electricity via photons. A basic thermophotovoltaic system consists of a hot object emitting thermal radiation and a photovoltaic cell similar to a solar cell but tuned to the spectrum being admitted from the hot object. As TPV systems generally work at lower temperatures than solar cells, their efficiencies tend to be low. Offsetting this through the use of multi-junction cells based on non-silicon materials is common, but generally very expensive. This currently limits TPV to niche roles like spacecraft power and waste heat collection from larger systems like steam turbines. General concept PV Typical photovoltaics work by creating a p–n junction near the front surface of a thin semiconductor material. When photons above the bandgap energy of the material hit atoms within the bulk lower layer, below the junction, an electron is photoexcited and becomes free of its atom. The junction creates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transistors
upright=1.4, gate (G), body (B), source (S) and drain (D) terminals. The gate is separated from the body by an insulating layer (pink). A transistor is a semiconductor device used to Electronic amplifier, amplify or electronic switch, switch electrical signals and electrical power, power. The transistor is one of the basic building blocks of modern electronics. It is composed of semiconductor material, usually with at least three terminals for connection to an electronic circuit. A voltage or current applied to one pair of the transistor's terminals controls the current through another pair of terminals. Because the controlled (output) power can be higher than the controlling (input) power, a transistor can amplify a signal. Some transistors are packaged individually, but many more are found embedded in integrated circuits. Austro-Hungarian physicist Julius Edgar Lilienfeld proposed the concept of a field-effect transistor in 1926, but it was not possible to actually construc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semiconductor Laser
The laser diode chip removed and placed on the eye of a needle for scale A laser diode (LD, also injection laser diode or ILD, or diode laser) is a semiconductor device similar to a light-emitting diode in which a diode pumped directly with electrical current can create lasing conditions at the diode's junction. Driven by voltage, the doped p–n-transition allows for recombination of an electron with a hole. Due to the drop of the electron from a higher energy level to a lower one, radiation, in the form of an emitted photon is generated. This is spontaneous emission. Stimulated emission can be produced when the process is continued and further generates light with the same phase, coherence and wavelength. The choice of the semiconductor material determines the wavelength of the emitted beam, which in today's laser diodes range from infra-red to the UV spectrum. Laser diodes are the most common type of lasers produced, with a wide range of uses that include fiber optic comm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infrared
Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around 1 millimeter (300 GHz) to the nominal red edge of the visible spectrum, around 700 nanometers (430 THz). Longer IR wavelengths (30 μm-100 μm) are sometimes included as part of the terahertz radiation range. Almost all black-body radiation from objects near room temperature is at infrared wavelengths. As a form of electromagnetic radiation, IR propagates energy and momentum, exerts radiation pressure, and has properties corresponding to both those of a wave and of a particle, the photon. It was long known that fires emit invisible heat; in 1681 the pioneering experimenter Edme Mariotte showed that glass, though transparent to sunlight, obstructed radiant heat. In 1800 the astronomer Sir William Herschel discovered ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Transistors"){kind=spacer}
