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Indium Selenide
Indium(III) selenide is a compound of indium and selenium. It has potential for use in photovoltaic devices and it has been the subject of extensive research. The two most common phases, α and β, have a layered structure, while γ is a "defect wurtzite structure." In all, there are five known forms (α, β, γ, δ, κ). The α- β phase transition is accompanied by a change in electrical conductivity. The band-gap of γ-In2Se3 is approximately 1.9 eV. The crystalline form of a sample can depend on the method of production, for example thin films of pure γ-In2Se3 have been produced from trimethylindium, InMe3, and hydrogen selenide, H2Se, using MOCVD techniques. Indium selenide has been shown to have excellent electronic properties in its two-dimensional (few-layer) form. Because of its air sensitivity, several processes have been developed to encapsulate the material for the integration in electronic devices. See also *Gallium(III) selenide *Indium chalcogenides *Nanoparticle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indium
Indium is a chemical element with the symbol In and atomic number 49. Indium is the softest metal that is not an alkali metal. It is a silvery-white metal that resembles tin in appearance. It is a post-transition metal that makes up 0.21 parts per million of the Earth's crust. Indium has a melting point higher than sodium and gallium, but lower than lithium and tin. Chemically, indium is similar to gallium and thallium, and it is largely intermediate between the two in terms of its properties. Indium was discovered in 1863 by Ferdinand Reich and Hieronymous Theodor Richter by spectroscopic methods. They named it for the indigo blue line in its spectrum. Indium was isolated the next year. Indium is a minor component in zinc sulfide ores and is produced as a byproduct of zinc refinement. It is most notably used in the semiconductor industry, in low-melting-point metal alloys such as solders, in soft-metal high-vacuum seals, and in the production of transparent conductive coati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selenium
Selenium is a chemical element with the symbol Se and atomic number 34. It is a nonmetal (more rarely considered a metalloid) with properties that are intermediate between the elements above and below in the periodic table, sulfur and tellurium, and also has similarities to arsenic. It seldom occurs in its elemental state or as pure ore compounds in the Earth's crust. Selenium – from Greek ( 'Moon') – was discovered in 1817 by , who noted the similarity of the new element to the previously discovered tellurium (named for the Earth). Selenium is found in metal sulfide ores, where it partially replaces the sulfur. Commercially, selenium is produced as a byproduct in the refining of these ores, most often during production. Minerals that are pure selenide or selenate compounds are known but rare. The chief commercial uses for selenium today are glassmaking and pigments. Selenium is a semiconductor and is used in photocells. Applications in electronics, once important, have been ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wurtzite (crystal Structure)
In crystallography, the hexagonal crystal family is one of the six crystal families, which includes two crystal systems (hexagonal and trigonal) and two lattice systems (hexagonal and rhombohedral). While commonly confused, the trigonal crystal system and the rhombohedral lattice system are not equivalent (see section crystal systems below). In particular, there are crystals that have trigonal symmetry but belong to the hexagonal lattice (such as α-quartz). The hexagonal crystal family consists of the 12 point groups such that at least one of their space groups has the hexagonal lattice as underlying lattice, and is the union of the hexagonal crystal system and the trigonal crystal system. There are 52 space groups associated with it, which are exactly those whose Bravais lattice is either hexagonal or rhombohedral. __TOC__ Lattice systems The hexagonal crystal family consists of two lattice systems: hexagonal and rhombohedral. Each lattice system consists of one Bravais la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Applied Physics Letters
''Applied Physics Letters'' is a weekly peer-reviewed scientific journal that is published by the American Institute of Physics. Its focus is rapid publication and dissemination of new experimental and theoretical papers regarding applications of physics in all disciplines of science, engineering, and modern technology. Additionally, there is an emphasis on fundamental and new developments which lay the groundwork for fields that are rapidly evolving.Home page Applied Physics Letters. American Institute of Physics. 2016.Overview Applied Physics Letters. American Institute of Physics. 2016. The journal was established in 1962. The |
Trimethylindium
Trimethylindium, often abbreviated to TMI or TMIn, is the organoindium compound with the formula In(CH3)3. It is a colorless, pyrophoric solid. Unlike trimethylaluminium, but akin to trimethylgallium, TMI is monomeric. Preparation TMI is prepared by the reaction of indium trichloride with methyl lithium. : InCl3 + 3LiMe → Me3In.OEt2 + 3LiCl Properties Compared to trimethylaluminium and trimethylgallium, InMe3 is a weaker Lewis acid. It forms adducts with secondary amines and phosphines. A complex with the heterocyclic triazine ligand (PriNCH2)3 forms a complex with 6-coordinate In, where the C-In-C angles are 114°-117° with three long bonds to the tridentate ligand with N-In-N angles of 48.6° and long In-N bonds of 278 pm. Structure In the gaseous state InMe3 is monomeric, with a trigonal planar structure, and in benzene solution it is tetrameric.''CVD of compound semiconductors, Precursor Synthesis, Development and Applications'', Anthony C. Jones, Paul O'Brien, John Wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Selenide
Hydrogen selenide is an inorganic compound with the formula H2Se. This hydrogen chalcogenide is the simplest and most commonly encountered hydride of selenium. H2Se is a colorless, flammable gas under standard conditions. It is the most toxic selenium compoundhttp://www.epa.gov/ttnatw01/hlthef/selenium.html, US Environmental Protection Agency, Air Toxins website with an exposure limit of 0.05 ppm over an 8-hour period.https://www.cdc.gov/niosh/idlh/7783075.html, Documentation of Immediately Dangerous to Life or Health Concentrations: Hydrogen Selenide, The National Institute for Occupational Safety and Healthhttps://www.cdc.gov/niosh/docs/81-123/pdfs/0336.pdf Occupational Health Guideline for Hydrogen Selenide, The National Institute for Occupational Safety and Health, 1978 Even at extremely low concentrations, this compound has a very irritating smell resembling that of decayed horseradish or 'leaking gas', but smells of rotten eggs at higher concentrations. Structure and propert ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MOCVD
Metalorganic vapour-phase epitaxy (MOVPE), also known as organometallic vapour-phase epitaxy (OMVPE) or metalorganic chemical vapour deposition (MOCVD), is a chemical vapour deposition method used to produce single- or polycrystalline thin films. It is a process for growing crystalline layers to create complex semiconductor multilayer structures. In contrast to molecular-beam epitaxy (MBE), the growth of crystals is by chemical reaction and not physical deposition. This takes place not in vacuum, but from the gas phase at moderate pressures (10 to 760 Torr). As such, this technique is preferred for the formation of devices incorporating thermodynamically metastable alloys, and it has become a major process in the manufacture of optoelectronics, such as Light-emitting diodes. It was invented in 1968 at North American Aviation (later Rockwell International) Science Center by Harold M. Manasevit. Basic principles In MOCVD ultrapure precursor gases are injected into a reactor, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gallium(III) Selenide
Gallium(III) selenide ( Ga2 Se3) is a chemical compound. It has a defect sphalerite (cubic form of ZnS) structure. It is a p-type semiconductor Temperature dependence of electrical conductivity and Hall effect of Ga2Se3 single crystal, A. E. Belal, Dr. H. A. El-shaikh, I. A. Ashraf Crystal Research and Technology,30, 1 , 135 - 139 It can be formed by union of the elements. It hydrolyses slowly in water and quickly in mineral acids to form toxic hydrogen selenide Hydrogen selenide is an inorganic compound with the formula H2Se. This hydrogen chalcogenide is the simplest and most commonly encountered hydride of selenium. H2Se is a colorless, flammable gas under standard conditions. It is the most toxic sel ... gas. The reducing capabilities of the selenide ion make it vulnerable to oxidizing agents. It is advised therefore that it not come into contact with bases. References Selenides Gallium compounds Semiconductor materials {{inorganic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indium Chalcogenides
The indium chalcogenides include all compounds of indium with the chalcogen elements, oxygen, sulfur, selenium and tellurium. (Polonium is excluded as little is known about its compounds with indium). The best-characterised compounds are the In(III) and In(II) chalcogenides e.g. the sulfides In2S3 and InS. This group of compounds has attracted a lot of research attention because they include semiconductors, photovoltaics and phase-change materials. In many applications indium chalcogenides are used as the basis of ternary and quaternary compounds such as indium tin oxide, ITO and copper indium gallium selenide, CIGS. Some compounds that were reported and have found their way into text books have not been substantiated by later researchers. The list of compounds below shows compounds that have been reported, and those compounds that have not had their structure determined, or whose existence has not been confirmed by the latest structural investigations, are in italics. There a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nanoparticle
A nanoparticle or ultrafine particle is usually defined as a particle of matter that is between 1 and 100 nanometres (nm) in diameter. The term is sometimes used for larger particles, up to 500 nm, or fibers and tubes that are less than 100 nm in only two directions. At the lowest range, metal particles smaller than 1 nm are usually called atom clusters instead. Nanoparticles are usually distinguished from microparticles (1-1000 µm), "fine particles" (sized between 100 and 2500 nm), and "coarse particles" (ranging from 2500 to 10,000 nm), because their smaller size drives very different physical or chemical properties, like colloidal properties and ultrafast optical effects or electric properties. Being more subject to the brownian motion, they usually do not sediment, like colloidal particles that conversely are usually understood to range from 1 to 1000 nm. Being much smaller than the wavelengths of visible light (400-700 nm), nano ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indium Compounds
Indium is a chemical element with the symbol In and atomic number 49. Indium is the softest metal that is not an alkali metal. It is a silvery-white metal that resembles tin in appearance. It is a post-transition metal that makes up 0.21 parts per million of the Earth's crust. Indium has a melting point higher than sodium and gallium, but lower than lithium and tin. Chemically, indium is similar to gallium and thallium, and it is largely intermediate between the two in terms of its properties. Indium was discovered in 1863 by Ferdinand Reich and Hieronymous Theodor Richter by spectroscopic methods. They named it for the indigo blue line in its spectrum. Indium was isolated the next year. Indium is a minor component in zinc sulfide ores and is produced as a byproduct of zinc refinement. It is most notably used in the semiconductor industry, in low-melting-point metal alloys such as solders, in soft-metal high-vacuum seals, and in the production of transparent conductive coatings ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selenides
A selenide is a chemical compound containing a selenium anion with oxidation number of −2 (Se2−), much as sulfur does in a sulfide. The chemistry of the selenides and sulfides is similar. Similar to sulfide, in aqueous solution, the selenide ion, Se2−, is prevalent only in very basic conditions. In neutral conditions, hydrogen selenide ion, HSe−, is most common. In acid conditions, hydrogen selenide, H2Se, is formed. Some selenides are reactive to oxidation by air. Owing to the greater reducing power of selenide, metal selenides are more easily decomposed to the elements than are sulfides (tellurides are even more labile). Selenides of electropositive metals: such as aluminium selenide readily hydrolyse, even in moist air, evolving toxic hydrogen selenide gas. Pure selenide minerals are rare, instead selenium tends to partially substitute for sulfide in many sulfide minerals. The degree of substitution is only of commercial interest for copper sulfide ores, in which case ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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