Abstract: An electrically conductive GaAs crystal has an atomic concentration of Si more than 1×1017 cm?3, wherein density of precipitates having sizes of at least 30 nm contained in the crystal is at most 400 cm?2. In this case, it is preferable that the conductive GaAs crystal has a dislocation density of at most 2×10?2 cm2 or at least 1×10?3 cm2.

Abstract: A system for simultaneously manufacturing more than one single crystal of a semiconductor material by physical vapor transport (PVT) includes a plurality of reactors and a common vacuum channel connecting at least a pair of reactors of the plurality of reactors. Each reactor has an inner chamber adapted to accommodate a PVT growth structure for growth of a single semiconductor crystal. The common vacuum channel is connectable to a vacuum pump system for creating and/or controlling a common gas phase condition in the inner chambers of the pair of reactors.

Abstract: The present invention discloses a method for preparing large-area transition metal dichalcogenide (TMDC) single-crystal films and the products obtained therefrom. The method comprises the steps of: (1) providing a single-crystal C-plane sapphire with surface steps along <1010> directions; and (2) taking the sapphire in step (1) as the substrate, generating unidirectionally arranged TMDC domains on the sapphire surface based on a vapor deposition method and keeping the domains continuously grow and merge into a large-area single-crystal film. The lateral size of the TMDC single-crystal films prepared by the method can reach inch level or above, and is limited only by the size of the substrate.

Abstract: Provided is a method for producing a single crystal, wherein compositional variations and defects in the single crystal can be prevented and a single crystal having uniform characteristics in the growth direction can be produced at high yield. In this method for producing a single crystal, a PbTiO3-containing single crystal is produced by the vertical Bridgman technique, wherein the thickness of a melt layer containing the melt in a crucible is at least 30 mm.

Abstract: Fabrication of doped AlN crystals and/or AlGaN epitaxial layers with high conductivity and mobility is accomplished by, for example, forming mixed crystals including a plurality of impurity species and electrically activating at least a portion of the crystal.

Abstract: A system for removing powder from an additively manufactured article includes a powder removal mechanism. The powder removal mechanism can include a build plate holder configured to hold a build plate at a distal end thereof. The powder removal mechanism can also include a first actuator that is configured to angle the build plate holder relative to gravity and a second actuator that is configured to rotate the build plate holder about a central axis of the build plate holder.

Abstract: A multi-junction solar cell having a first subcell made of an InGaAs compound. The first subcell has a first lattice constant and A second subcell has a second lattice constant. The first lattice constant is at least 0.008 ? greater than the second lattice constant. A metamorphic buffer is formed between the first subcell and the second subcell and has a sequence of at least three layers and a lattice constant increases from layer to layer in the sequence in the direction toward the first subcell. The lattice constants of the layers of the buffer are greater than the second lattice constant, and a layer of the metamorphic buffer has a third lattice constant that is greater than the first lattice constant. A number N of compensation layers for compensating the residual stress of the metamorphic buffer is formed between the metamorphic buffer and the first subcell.

Abstract: Fabrication of doped AlN crystals and/or AlGaN epitaxial layers with high conductivity and mobility is accomplished by, for example, forming mixed crystals including a plurality of impurity species and electrically activating at least a portion of the crystal.

Abstract: A piezoelectric thin film comprises aluminum nitride containing a monad and at least one type among a tetrad and a pentad. The piezoelectric thin film having a large electromechanical coupling factor and a small stiffness.

Abstract: In various embodiments, growth of large, high-quality single crystals of aluminum nitride is enabled via a two-stage process utilizing two different crystalline seeds.

Abstract: A crystal growth furnace comprising a crucible containing at least feedstock material and a liquid-cooled heat exchanger that is vertically movable beneath the crucible to extract heat from it to promote the growth of a crystalline ingot is disclosed. The liquid-cooled heat exchanger comprises a heat extraction bulb made of high thermal conductivity material that is vertically movable into thermal communication with the crucible to extract heat from the crucible using a liquid coolant. A liquid-cooled heat exchanger enclosed in a sealed tubular outer jacket is also disclosed as is a method for producing a crystalline ingot using a vertically movable liquid-cooled heat exchanger.

Abstract: In the present invention the torch movement period is 20-40 seconds, with the torch movement period being the time required to move plasma torches (which heat the surface of molten metal in the casting mold) one time. The average heat input amount at multiple sites, which are obtained by dividing the initial solidification portion (which is where the molten metal makes contact with the casting mold and first solidifies) into multiple sites in the circumferential direction of the casting mold, is 1.0-2.0 MW/m2. The molten metal advection time, which is the time required for electromagnetically stirred molten metal to travel the length of the torch heating region of the surface of the molten metal in the lengthwise direction of the casting mold, is 3.5 seconds or less.

Abstract: Systems and methods for perovskite single crystal growth include using a low temperature solution process that employs a temperature gradient in a perovskite solution in a container, also including at least one small perovskite single crystal, and a substrate in the solution upon which substrate a perovskite crystal nucleates and grows, in part due to the temperature gradient in the solution and in part due to a temperature gradient in the substrate. For example, a top portion of the substrate external to the solution may be cooled.

Abstract: Provided is a vitreous silica crucible, which is resistant to deformation and corrosion even when heated at high temperature for a long time. There is provided a vitreous silica crucible of the present invention including a substantially cylindrical straight body portion, a curved bottom portion, and a corner portion smoothly connecting the straight body portion and the bottom portion, wherein a wall of the vitreous silica crucible includes, from an inner surface side, a transparent layer and a bubble-containing layer, and a ratio of a thickness of the bubble-containing layer with respect to a thickness of the transparent layer at an intermediate position between an upper end and a lower end of the straight body portion is 0.7 to 1.4.

Abstract: Apparatus and method for a crucible-less production of silicon ingots, wherein a support with a seed layer and a liquid layer is gradually lowered in a temperature field with a vertical gradient to solidify the liquid layer in a controlled way.

Abstract: Method for producing a silicon ingot, comprising the following steps: providing a container to receive a silicon melt, providing a temperature control device to control the temperature of the silicon melt in the container, arranging raw material in the container comprising silicon and at least one nucleation agent to assist a heterogeneous nucleation in the silicon melt, and control of the temperature in the container for the directed solidification of the silicon melt, the nucleation agent comprising nanoscale particles.

Abstract: A directional solidification furnace includes a crucible for holding molten silicon and a lid covering the crucible and forming an enclosure over the molten silicon. The crucible also includes an inlet in the lid for introducing inert gas above the molten silicon to inhibit contamination of the molten silicon.

Abstract: Systems and methods for crystal growth are provided. One method includes producing a lateral thermal profile in a furnace having a crucible therein containing a material for growing a crystal. The lateral thermal profile has three zones, wherein the first and third zones have temperatures above and below a melting point of the material, respectively, and the second zone has a plurality of temperatures with at least one temperature equal to the melting point of the material. The method further includes combining the lateral thermal profile with a vertical thermal gradient produced in the furnace, wherein the vertical thermal gradient causes a point in a bottom of the crucible located in the third zone to be the coldest point in the crucible. The method also includes transferring heat from the first and second zones to the third zone to produce a leading edge of the interface.

Abstract: A device for the production of silicon blocks comprises a vessel for receiving a silicon melt, the vessel comprising a vessel wall comprising at least one side wall and a bottom as well as an inside and an outside and a central longitudinal axis, and means for creating a temperature field on the inside of the bottom, the temperature field having a temperature gradient at the bottom of the vessel which is perpendicular to the central longitudinal axis at least in some regions when the silicon melt cools down for crystallization.

Abstract: In a crystalline silicon formation apparatus, a quick cooling method is applied to the bottom of a crucible to control a growth orientation of a polycrystalline silicon grain, such that the crystal grain forms twin boundary, and the twin boundary is a symmetric grain boundary, and the crystal grain is solidified and grown upward in unidirection to form a complete polycrystalline silicon, such that defects or impurities will not form in the polycrystalline silicon easily.

Abstract: A method of growing a single crystal material using a device that includes a conical plug. The conical plug includes a first portion defining a first conical hole about an axis, the first conical hole having a first angle, and includes a second portion contiguous with the first portion and defining a second conical hole about the axis, the second conical hole having a second angle having the same sign as the first angle and being greater than the first angle. The device includes an upper tube comprising the conical plug fused therein and a seeding well plug. The device includes a lower tube including the seeding well plug fused therein. A single crystal KPb2Cl5 material is grown from the oriented single crystal KPb2Cl5 seed through the first conical hole and then the second conical hole and then with continuing growth in the upper tube.

Abstract: A crystalline silicon ingot is produced using a directional solidification process. In particular, a crucible is loaded with silicon feedstock above a seed layer of uniform crystalline orientation. The silicon feedstock and an upper part of the seed layer are melted forming molten material in the crucible. This molten material is then solidified, during which process a crystalline structure based on that of the seed layer is formed in a silicon ingot. The seed layer is arranged such that a {110} crystallographic plane is normal to the direction of solidification and also so that a peripheral surface of the seed layer predominantly also lies in a {110} crystallographic plane. It is found that this arrangement offers a substantial improvement in the proportion of mono-crystalline silicon formed in the ingot as compared to alternative crystallographic orientations.

Abstract: The present invention relates to a method for the preparation of solar grade silicon comprising crystallization of large high purity silicon crystals in a hyper eutectic binary or ternary alloy containing silicon, or a refined silicon melt, wherein small silicon crystals are added to the melt and the resulting large silicon crystals are separated from the melt. The separation may be performed by centrifugation or filtration.

Abstract: A crucible made of molybdenum or a molybdenum alloy having a molybdenum content of more than 95 at % for producing an oxide-ceramic single crystal. The inner side of the crucible is at least partially provided with a layer that contains at least one refractory metal and is formed with pores.

Abstract: A method and apparatus for growing truly bulk In2O3 single crystals from the melt, as well as melt-grown bulk In2O3 single crystals are disclosed. The growth method comprises a controlled decomposition of initially non-conducting In2O3 starting material (23) during heating-up of a noble metal crucible (4) containing the In2O3 starting material (23) and thus increasing electrical conductivity of the In2O3 starting material with rising temperature, which is sufficient to couple with an electromagnetic field of an induction coil (6) through the crucible wall (24) around melting point of In2O3. Such coupling leads to an electromagnetic levitation of at least a portion (23.1) of the liquid In2O3 starting material with a neck (26) formation acting as crystallization seed. During cooling down of the noble metal crucible (4) with the liquid In2O3 starting material at least one bulk In2O3 single crystal (28.1, 28.2) is formed.

Abstract: Provided are an apparatus and method of extracting a silicon ingot. The apparatus for extracting a silicon ingot includes a chamber in which a silicon source material introduced into a cold crucible is melted, a primary extraction apparatus vertically movably installed in the chamber and configured to solidify the molten silicon to extract the silicon ingot, a movable apparatus configured to horizontally move the primary extraction apparatus, and a secondary extraction apparatus vertically movably installed under the chamber and configured to extract the silicon ingot in a state in which the primary extraction apparatus is moved to one side. Therefore, as the height of the extraction apparatus is reduced, manufacturing cost of equipment can be reduced and installation space of the extraction apparatus can also be reduced.

Abstract: Provided is a process for producing colloidal crystals from which a large single crystal reduced in lattice defects and unevenness can be easily produced at low cost without fail. The process for colloidal crystal production comprises: preparing a colloidal polycrystal dispersion in which colloidal crystals precipitate at a given temperature (preparation step); introducing into a vessel The colloidal polycrystal dispersion in the state of containing fine colloidal polycrystals precipitated (introduction step); and melting the colloidal polycrystals and then recrystallizing the molten polycrystals (recrystallization step). The crystals thus obtained have fewer lattice defects and less unevenness than the original polycrystals.

Abstract: A polycrystalline silicon rod is formed of polycrystalline silicon deposited radially around a silicon core line and is characterized by, in a cross-section that is a perpendicular cut in respect to the axial direction of a cylindrical rod, a ratio of surface area covered by coarse crystal particles having a diameter of 50 ?m or greater is 20% or more of the crystal observed at the face, excluding the core line portion.

Abstract: Method for producing silicon-ingots (1) comprising the following steps: Providing a silicon melt (3), growing a block (2) of silicon from said silicon melt (3), said block (2) having a predetermined crystal orientation, cutting said block (2) along at least one cutting plane (16, 17, 18) into a number of silicon-ingots (1).

Abstract: A growth apparatus is used having a plurality of crucibles each for containing the solution, a heating element for heating the crucible, and a pressure vessel for containing at least the crucibles and the heating element and for filling an atmosphere comprising at least nitrogen gas. One seed crystal is put in each of the crucibles to grow the nitride single crystal on the seed crystal.

Abstract: A sapphire crystal growth apparatus is provided that includes a chamber, a hot zone and a muffle. More specifically, the hot zone is disposed within the chamber and includes at least one heating system, at least one heat removal system, and a crucible containing feedstock. Additionally, a muffle that surrounds at least two sides of the crucible is also provided to ensure uniform temperature distribution through the feedstock during crystal growth to allow the crystalline material to be grown with a square or rectangular shaped cross section.

Abstract: A method for recharging a crucible with polycrystalline silicon comprises adding flowable chips to a crucible used in a Czochralski-type process. Flowable chips are polycrystalline silicon particles made from polycrystalline silicon prepared by a chemical vapor deposition process, and flowable chips have a controlled particle size distribution, generally nonspherical morphology, low levels of bulk impurities, and low levels of surface impurities. Flowable chips can be added to the crucible using conventional feeder equipment, such as vibration feeder systems and canister feeder systems.

Abstract: The present disclosure provides an apparatus for manufacturing a silicon substrate for solar cells using continuous casting, which can improve quality, productivity and energy conversion efficiency of the silicon substrate. The apparatus includes a crucible unit configured to receive raw silicon and having a discharge port, a heating unit provided to an outer wall and an external bottom surface of the crucible unit and heating the crucible unit to form molten silicon, a casting unit casting the molten silicon into a silicon substrate, a cooling unit rapidly cooling the silicon substrate, and a transfer unit disposed at one end of the cooling unit and transferring the silicon substrate. The casting unit includes a casting unit body having a casting space defined therein to be horizontally connected to the discharge port, and an assistant heating mechanism that preheats the casting unit body to control a solidification temperature of the silicon substrate.

Abstract: The present invention relates to a method for purifying silicon, comprising at least the following steps: c) providing a container (1) that comprises silicon (10) in molten state, the container (1) having a longitudinal axis (X) and the silicon (10) in molten state defining a free surface (11) on the side opposite the bottom (4) of the container (1); d) imposing on the silicon (10) in molten state conditions that are favourable for the solidification thereof, the mean temporal velocity for the duration of step b) of propagating the solidification front (13) of the silicon, measured along the longitudinal axis (X) of the container (1), being no lower than 5 ?m/s, preferably 10 ?m/s; said method being characterised in that at least one stirring system (30) imposes, during all or part of step b), a flow of silicon (10) in molten state with a Reynolds number comprised between 3 104 and 3 106, preferably between 105 and 106.

Abstract: The present invention relates to the purification of silicon. The present invention provides a method for purification of silicon. The method includes recrystallizing starting material-silicon from a molten solvent comprising aluminum to provide final recrystallized-silicon crystals. The method also includes washing the final recrystallized-silicon crystals with an aqueous acid solution to provide a final acid-washed-silicon. The method also includes directionally solidifying the final acid-washed-silicon to provide final directionally solidified-silicon crystals.

Abstract: A method of removing material from a sapphire article is described. In particular, the method comprises the step of providing an initial sapphire layer and reducing the thickness of the layer while not significantly increasing the surface roughness of the layer. Cover plates for electronic device and methods of preparing them are also disclosed, along with a method of analyzing a sapphire article produced by the present method.

Abstract: A method of removing material from a sapphire article is described. In particular, the method comprises the step of providing an initial sapphire layer and reducing the thickness of the layer while not significantly increasing the surface roughness of the layer, Cover plates for electronic device and methods of preparing them are also disclosed, along with a method of analyzing a sapphire article produced by the present method.

Abstract: An apparatus for growth of uniform multi-component single crystals is provided. The single crystal material has at least three elements and has a diameter of at least 50 mm, a dislocation density of less than 100 cm?2 and a radial compositional variation of less than 1%.

Abstract: A process and system may be employed to produce large, defect-free oxide crystals with high melting points which may utilize a water-cooled horizontal furnace with a hot zone design comprising multiple independently controllable heaters surrounded by a vapor shield and various layers of thermal insulation of varying thickness and composition. Raw materials such as sapphire crystals or alumina powder may be placed in a crucible or boat that may be positioned to ride on rollers. The crucible may be pulled (or pushed) through a furnace environment surrounded by a vapor shield and insulation at a controlled rate to melt and then crystallize the raw material into a sapphire crystal. The vacuum level may be controlled by a vacuum system attached to the furnace. Process parameters such as power, temperature, pulling speed (i.e.

Abstract: The present invention relates to a gas flow guiding device for use in a crystal-growing furnace. The gas flow guiding device has an insulation layer enclosing a crucible, a gas inlet mounted in the upper insulation layer, and a gas exit formed in the lateral insulation layer. A plurality of guide plates are radially arranged around the opening of the gas inlet, so that the free surface of the melt is blown by the guided gas flow in such a manner that the gas flow takes the impurity away from the free surface efficiently. As a result, the crystal ingot obtained by solidifying the melt will exhibit a reduced concentration of impurities and an improved crystal quality.

Abstract: When a group III nitride crystal is grown in a pressurized atmosphere of a nitrogen-containing gas from a melt 50 including at least a group III element, nitrogen and an alkali metal or an alkali earth metal, a melt-holding vessel 160 that holds the above-described melt 50 is swung about two axes different in direction from each other such as an X-axis and a Y-axis.

Abstract: A method for producing the growth of a semiconductor material, in particular of type II-VI, uses a melt of the semiconductor placed in a sealed bulb under vacuum or under controlled atmosphere, the bulb being subjected to a sufficient temperature gradient for first maintaining the melt in the liquid state, then causing its progressive crystallization from the surface towards the bottom. The method further comprises an element capable of floating on the surface of the melt, and equipped with a substantially central bore, intended for receiving a seed crystal for permitting the nucleation leading to the preparation of a seed crystal, and also supporting the seed crystal above the melt while maintaining it in contact with the melt in order to permit the continued crystallization from the seed crystal by lowering the temperature gradient.

Abstract: In one embodiment, a crystal includes at least one metal halide; and an activator dopant comprising ytterbium. In another general embodiment, a scintillator optic includes: at least one metal halide doped with a plurality of activators, the plurality of activators comprising: a first activator comprising europium, and a second activator comprising ytterbium. In yet another general embodiment, a method for manufacturing a crystal suitable for use in a scintillator includes mixing one or more salts with a source of at least one dopant activator comprising ytterbium; heating the mixture above a melting point of the salt(s); and cooling the heated mixture to a temperature below the melting point of the salts. Additional materials, systems, and methods are presented.

Abstract: Disclosed is a method for producing a compound semiconductor epitaxial substrate having a pn junction by selective growth which is characterized by using a base substrate having an average residual strain of not more than 1.0×10?5.

Abstract: A method for growing islands of semiconductor monocrystals from a solution on an amorphous substrate includes the procedures of depositing a semiconductor-metal mixture layer, applying lithography and etching for forming at least one platform, heating the at least one platform, and saturating the semiconductor-metal solution until a monocrystal of the semiconductor component is formed. The procedure of depositing a semiconductor-metal mixture layer, includes a semiconductor component and at least one other metal component, is performed on top of the amorphous substrate. The procedure of applying lithography and etching to the semiconductor-metal mixture layer and a portion of the amorphous substrate is performed for forming at least one platform, the at least one platform having a top view shape corresponding to crystal growth direction and habit respective of the semiconductor component.

Abstract: The invention relates to a device and a method for producing crystalline bodies by directional solidification. The device comprises a melting furnace (11) having a heating chamber (12) in which at least one supporting surface (13) for a crucible (8) and at least one gas purging device arranged above the supporting surface (13) and having a gas outlet facing the supporting surface (13) are defined. An embodiment of the device is characterized in that the gas outlet is defined by one or more openings in a lower plunger surface of a plunger-shaped element (2) which has a geometry adapted to the inner shape of the crucible (8), said shape allowing an at least partial insertion of the plunger-shaped body (2) into the crucible (8). The gas purging device and/or the supporting surface (13) comprise an adjusting mechanism or are designed to be adjustable in such a manner that they allow an adjustment of a perpendicular distance between the supporting surface (13) and the plunger-shaped body (2).

Abstract: A furnace for growing sapphire crystal in which the furnace comprises a furnace housing; a hot zone which comprises insulation and a heater which are both accommodated within the furnace housing; a crucible located within the hot zone and the crucible has an opening. Either a crucible lid covers the opening of the crucible, and the crucible lid has a first conduit which extends therefrom or a crucible enclosure surrounds at least a side wall and a top portion of the crucible and the crucible enclosure is impermeable to at least carbon preventing carbon contamination of a melt contained within the crucible.

Abstract: Bulk single crystal of aluminum nitride (AlN) having an areal planar defect density?100 cm?2. Methods for growing single crystal aluminum nitride include melting an aluminum foil to uniformly wet a foundation with a layer of aluminum, the foundation forming a portion of an AlN seed holder, for an AlN seed to be used for the AlN growth. The holder may consist essentially of a substantially impervious backing plate.

Abstract: A high temperature furnace comprising hot zone insulation having at least one shaped thermocouple assembly port to reduce temperature measurement variability is disclosed. The shaped thermocouple assembly port has an opening in the insulation facing the hot zone that is larger than the opening on the furnace shell side of the insulation. A method for producing a crystalline ingot in a high temperature furnace utilizing insulation having a shaped thermocouple assembly port is also disclosed.

Abstract: A process is disclosed for producing a doped gallium arsenide single crystal by melting a gallium arsenide starting material and subsequently solidifying the gallium arsenide melt, wherein the gallium arsenide melt contains an excess of gallium relative to the stoichiometric composition, and wherein it is provided for a boron concentration of at least 5×1017 cm?3 in the melt or in the obtained crystal. The thus obtained crystal is characterized by a unique combination of low dislocation density, high conductivity and yet excellent, very low optic absorption, particularly in the range of the near infrared.