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INAS World Championships
Indium arsenide, InAs, or indium monoarsenide, is a narrow-bandgap semiconductor composed of indium and arsenic. It has the appearance of grey cubic crystals with a melting point of 942 °C. Indium arsenide is similar in properties to gallium arsenide and is a direct bandgap material, with a bandgap of 0.35 eV at room temperature. Indium arsenide is used for construction of infrared detectors, for the wavelength range of 1–3.8 µm. The detectors are usually photovoltaic photodiodes. Cryogenically cooled detectors have lower noise, but InAs detectors can be used in higher-power applications at room temperature as well. Indium arsenide is also used for making of diode lasers. InAs is well known for its high electron mobility and narrow energy bandgap. It is widely used as terahertz radiation source as it is a strong photo-Dember emitter. The optoelectronic properties and phonon vibrations are slightly changed under the effect of temperature over the range form 0 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zincblende (crystal Structure)
In crystallography, the cubic (or isometric) crystal system is a crystal system where the Crystal_structure#Unit_cell, unit cell is in the shape of a cube. This is one of the most common and simplest shapes found in crystals and minerals. There are three main varieties of these crystals: *Primitive cubic (abbreviated ''cP'' and alternatively called simple cubic) *Body-centered cubic (abbreviated ''cI'' or bcc) *Face-centered cubic (abbreviated ''cF'' or fcc, and alternatively called Close-packing_of_equal_spheres, ''cubic close-packed'' or ccp) Each is subdivided into other variants listed below. Although the ''unit cells'' in these crystals are conventionally taken to be cubes, the primitive_cell, primitive unit cells often are not. Bravais lattices The three Bravais lattices in the cubic crystal system are: The primitive cubic lattice (cP) consists of one Lattice_(group), lattice point on each corner of the cube; this means each simple cubic unit cell has in total one latt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photodiode
A photodiode is a light-sensitive semiconductor diode. It produces current when it absorbs photons. The package of a photodiode allows light (or infrared or ultraviolet radiation, or X-rays) to reach the sensitive part of the device. The package may include lenses or optical filters. Devices designed for use specially as a photodiode use a PIN junction rather than a p–n junction, to increase the speed of response. Photodiodes usually have a slower response time as their surface area increases. A photodiode is designed to operate in reverse bias. A solar cell used to generate electric solar power is a large area photodiode. Photodiodes are used in scientific and industrial instruments to measure light intensity, either for its own sake or as a measure of some other property (density of smoke, for example). A photodiode can be used as the receiver of data encoded on an infrared beam, as in household remote controls. Photodiodes can be used to form an optocoupler, allowing tra ... [...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] |
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] |
Lattice Constant
A lattice constant or lattice parameter is one of the physical dimensions and angles that determine the geometry of the unit cells in a crystal lattice, and is proportional to the distance between atoms in the crystal. A simple cubic crystal has only one lattice constant, the distance between atoms, but in general lattices in three dimensions have six lattice constants: the lengths ''a'', ''b'', and ''c'' of the three cell edges meeting at a vertex, and the angles ''α'', ''β'', and ''γ'' between those edges. The crystal lattice parameters ''a'', ''b'', and ''c'' have the dimension of length. The three numbers represent the size of the unit cell, that is, the distance from a given atom to an identical atom in the same position and orientation in a neighboring cell (except for very simple crystal structures, this will not necessarily be disance to the nearest neighbor). Their SI unit is the meter, and they are traditionally specified in angstroms (Å); an angstrom being 0.1 nanome ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Dot
Quantum dots (QDs) are semiconductor particles a few nanometres in size, having light, optical and electronics, electronic properties that differ from those of larger particles as a result of quantum mechanics. They are a central topic in nanotechnology. When the quantum dots are illuminated by UV light, an electron in the quantum dot can be excited to a state of higher energy. In the case of a semiconductor, semiconducting quantum dot, this process corresponds to the transition of an electron from the valence band to the conductance band. The excited electron can drop back into the valence band releasing its energy as light. This light emission (photoluminescence) is illustrated in the figure on the right. The color of that light depends on the energy difference between the conductance band and the valence band, or the transition between discrete energy states when band structure is no longer a good definition in QDs. In the language of materials science, nanoscale semiconductor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Band Gap
In solid-state physics, a band gap, also called an energy gap, is an energy range in a solid where no electronic states can exist. In graphs of the electronic band structure of solids, the band gap generally refers to the energy difference (in electron volts) between the top of the valence band and the bottom of the conduction band in insulators and semiconductors. It is the energy required to promote a valence electron bound to an atom to become a conduction electron, which is free to move within the crystal lattice and serve as a charge carrier to conduct electric current. It is closely related to the HOMO/LUMO gap in chemistry. If the valence band is completely full and the conduction band is completely empty, then electrons cannot move within the solid because there are no available states. If the electrons are not free to move within the crystal lattice, then there is no generated current due to no net charge carrier mobility. However, if some electrons transfer from th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indium Gallium Arsenide
Indium gallium arsenide (InGaAs) (alternatively gallium indium arsenide, GaInAs) is a ternary alloy (chemical compound) of indium arsenide (InAs) and gallium arsenide (GaAs). Indium and gallium are ( group III) elements of the periodic table while arsenic is a (group V) element. Alloys made of these chemical groups are referred to as "III-V" compounds. InGaAs has properties intermediate between those of GaAs and InAs. InGaAs is a room-temperature semiconductor with applications in electronics and photonics. The principal importance of GaInAs is its application as a high-speed, high sensitivity photodetector of choice for optical fiber telecommunications. Nomenclature Indium gallium arsenide (InGaAs) and gallium-indium arsenide (GaInAs) are used interchangeably. According to IUPAC standards the preferred nomenclature for the alloy is GaxIn1-xAs where the group-III elements appear in order of increasing atomic number, as in the related alloy system AlxGa1-xAs. By far, the m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ternary Compound
In inorganic chemistry and materials chemistry, a ternary compound or ternary phase is a chemical compound containing three different elements. While some ternary compounds are molecular, ''e.g.'' chloroform (), more typically ternary phases refer to extended solids. Famous example are the perovskites. Binary phases, with only two elements, have lower degrees of complexity than ternary phases. With four elements, quaternary phases are more complex. The number of isomers of a ternary compound provide a distinction between inorganic and organic chemistry: "In inorganic chemistry one or, at most, only a few compounds composed of any two or three elements were known, whereas in organic chemistry the situation was very different." Ternary crystalline compounds An example is sodium phosphate, . The sodium ion has a charge of 1+ and the phosphate ion has a charge of 3–. Therefore, three sodium ions are needed to balance the charge of one phosphate ion. Another example of a ter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indium Phosphide
Indium phosphide (InP) is a binary semiconductor composed of indium and phosphorus. It has a face-centered cubic ("zincblende") crystal structure, identical to that of GaAs and most of the III-V semiconductors. Manufacturing Indium phosphide can be prepared from the reaction of white phosphorus and indium iodide at 400 °C., also by direct combination of the purified elements at high temperature and pressure, or by thermal decomposition of a mixture of a trialkyl indium compound and phosphine. Uses InP is used in high-power and high-frequency electronics because of its superior electron velocity with respect to the more common semiconductors silicon and gallium arsenide. It was used with indium gallium arsenide to make a record breaking pseudomorphic heterojunction bipolar transistor that could operate at 604 GHz. It also has a direct bandgap, making it useful for optoelectronics devices like laser diodes. The company Infinera uses indium phosphide as its major techn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
