Produced is a large single crystal with no crystal grain boundary, which is a high-quality single crystal that has a uniform composition in both the vertical and horizontal directions at an optimum dopant concentration. Provided is a single-crystal production equipment which includes, at least: a raw material supply apparatus which supplies a granular raw material to a melting apparatus positioned therebelow; the melting apparatus heats and melts the granular raw material to generate a raw material melt and supplies the raw material melt into a single-crystal production crucible positioned therebelow; and a crystallization apparatus which includes the single-crystal production crucible in which a seed single crystal is placed on the bottom, and a first infrared ray irradiation equipment which irradiates an infrared ray to the upper surface of the seed single crystal in the single-crystal production crucible, and the single-crystal production equipment is configured such that the raw material melt is dropped into a melt formed by irradiating the upper surface of the seed single crystal with the infrared ray, and a single crystal is allowed to precipitate out of the thus formed mixed melt.

In a gallium arsenide crystal body, an etching pit density of the gallium arsenide crystal body is more than or equal to 10 cm.sup.2 and less than or equal to 10000 cm.sup.2, and an oxygen concentration of the gallium arsenide crystal body is less than 7.010.sup.15 atoms.Math.cm.sup.3. In a gallium arsenide crystal substrate, an etching pit density of the gallium arsenide crystal substrate is more than or equal to 10 cm.sup.2 and less than or equal to 10000 cm.sup.2, and an oxygen concentration of the gallium arsenide crystal substrate is less than 7.010.sup.15 atoms.Math.cm.sup.3.

A crucible for manufacturing semiconductor crystals may be disposed adjacent to a heating element. The crucible may include a first seed crystal site and a second seed crystal site at opposed ends of the crucible. A compartment may be defined between an outer wall and an inner wall of the crucible, where the inner wall is formed with a porous graphite membrane. Source powder loaded into the compartment may then be heated by the heating element to sublimate and diffuse from the compartment and through the inner wall to provide crystal growth of a first seed crystal at the first seed crystal site and of a second seed crystal at the second seed crystal site.

Certain electronic applications, such as OLED display back panels, require small islands of high-quality semiconductor material distributed over a large area. This area can exceed the areas of crystalline semiconductor wafers that can be fabricated using the traditional boule-based techniques. This specification provides a method of fabricating a crystalline island of an island material, the method comprising depositing particles of the island material abutting a substrate, heating the substrate and the particles of the island material to melt and fuse the particles to form a molten globule, and cooling the substrate and the molten globule to crystallize the molten globule, thereby securing the crystalline island of the island material to the substrate. The method can also be used to fabricate arrays of crystalline islands, distributed over a large area, potentially exceeding the areas of crystalline semiconductor wafers that can be fabricated using boule-based techniques.

The present invention discloses a directional solidification method for a superalloy single crystal blade based on solid-liquid interface steady control. The method establishes effective criteria for withdrawal speed adjustment, i.e. the related position between a macro solid-liquid interface and a thermal baffle, the range between the dendrite tips at the solid-liquid interface, and the difference between the advance speed of the macro solid-liquid interface and the withdrawal speed. With these criteria, the advance of the solid-liquid interface during directional solidification is simulated and a withdrawal speed curve v(t) for the solid-liquid interface steady advancement was obtained. And then, the single crystal blade was prepared.

A casting method includes forming a seed. The seed has a first end and a second end and an inner diameter (ID) surface and an outer diameter (OD) surface. The seed second end is placed in contact or spaced facing relation with a chill plate. The first end is contacted with molten material. The molten material is cooled and solidified so that a crystalline structure of the seed propagates into the solidifying material. At least a portion of the seed contacted with the molten material has a solidus higher than a solidus of at least an initial pour portion of the molten material.

Provided is a device for manufacturing monocrystalline silicon and a cooling method thereof. The device includes a crystal puller and a cooling apparatus. A heating apparatus and a first thermal insulation structure are arranged in the crystal puller. The first thermal insulation structure is located above the heating apparatus. The cooling apparatus includes a jacking mechanism and a cooling pipe. The cooling pipe is capable of moving into or out of the crystal puller. When the cooling pipe enters the crystal puller, the cooling pipe is connected to the first thermal insulation structure, and the cooling pipe lifts the first thermal insulation structure through the jacking mechanism to increase a distance between the first thermal insulation structure and the heating apparatus, and a cooling medium is output to the cooling pipe to cool the crystal puller. The cooling medium may be liquid or gas.

GaAs IR window slabs having largest dimensions that are greater than 8 inches, and preferably greater than 12 inches, are grown using the Horizontal Gradient Freeze (HGF) method. Heat extraction is simplified by using a shallow horizontal boat that is only slightly deeper than the desired window thickness, thereby enabling growth of large slabs while also minimizing material waste and fabrication cost as compared to slicing and shaping thick plates from large, melt-grown boules. Single crystal seeds can be used to optimize the final orientation of the slabs and minimize secondary nucleation, thereby maximizing yield. A conductive doped GaAs layer can be applied to the IR window slab to provide EMI shielding. The temperature gradient during HGF can be between 1? C./cm and 3? C./cm, and the directional solidification can be at a rate of between 0.25 mm/h and 2.5 mm/h.

A casting system for forming a directionally-solidified casting component is provided. The casting system defines an axial direction, a radial direction, and a circumferential direction. The casting system includes a chamber and a baffle plate disposed within the chamber. The chamber and the baffle plate collectively define a heating zone and a cooling zone. The heating zone and the cooling zone are separated by the baffle plate. The casting system further includes a shaft and a cooling plate disposed on the shaft. The cooling plate is movable between the heating zone and the cooling zone. A mold shell is disposed on the cooling plate. The casting system further includes a cooling system for directing a coolant fluid towards the mold shell.

A compound of cesium fluorooxoborate, a nonlinear optical crystal of cesium fluorooxoborate, and a method of preparation and use thereof. The compound has a chemical formula of CsB.sub.4O.sub.6F and a molecular weight of 291.15. It has a crystal structure, which is prepared by a solid-state synthesis method or a vacuum encapsulation method. The crystal has a chemical formula of CsB.sub.4O.sub.6F and a molecular weight of 291.15. It belongs to an orthorhombic crystal system, with a space group of Pna2.sub.1, crystal cell parameters of a=7.9241 , b=11.3996 , c=6.6638 , and ===90, and a unit cell volume of 601.95 .sup.3. A melt method, high temperature solution method, vacuum encapsulation method, hydrothermal method or room temperature solution method is used to grow the crystal of CsB.sub.4O.sub.6F.