A method for growing beta phase of gallium oxide (β-Ga.sub.2O.sub.3) single crystals from the melt contained within a metal crucible surrounded by a thermal insulation and heated by a heater. A growth atmosphere provided into a growth furnace has a variable oxygen concentration or partial pressure in such a way that the oxygen concentration reaches a growth oxygen concentration value (C2, C2′, C2″) in the concentration range (SC) of 5-100 vol. % below the melting temperature (MT) of Ga.sub.2O.sub.3 or at the melting temperature (MT) or after complete melting of the Ga.sub.2O.sub.3 starting material adapted to minimize creation of metallic gallium amount and thus eutectic formation with the metal crucible. During the crystal growth step of the β-Ga.sub.2O.sub.3 single crystal from the melt at the growth temperature (GT) the growth oxygen concentration value (C2, C2′, C2″) is maintained within the oxygen concentration range (SC).

Methods and systems for low etch pit density 6 inch semi-insulating gallium arsenide wafers may include a semi-insulating gallium arsenide single crystal wafer having a diameter of 6 inches or greater without intentional dopants for reducing dislocation density, an etch pit density of less than 1000 cm.sup.−2, and a resistivity of 1×10.sup.7 Ω-cm or more. The wafer may have an optical absorption of less than 5 cm.sup.−1 less than 4 cm.sup.−1 or less than 3 cm.sup.−1 at 940 nm wavelength. The wafer may have a carrier mobility of 3000 cm.sup.2/V-sec or higher. The wafer may have a thickness of 500 μm or greater. Electronic devices may be formed on a first surface of the wafer. The wafer may have a carrier concentration of 1.1×10.sup.7 cm.sup.−3 or less.

A gallium oxide crystal manufacturing device includes a crucible to hold a gallium oxide source material therein, a crucible support that supports the crucible from below, a crucible support shaft that is connected to the crucible support from below and vertically movably supports the crucible and the crucible support, a tubular furnace core tube that surrounds the crucible, the crucible support and the crucible support shaft, a tubular furnace inner tube that surrounds the furnace core tube, and a resistive heating element including a heat-generating portion placed in a space between the furnace core tube and the furnace inner tube. Melting points of the furnace core tube and the furnace inner tube are not less than 1900° C. A thermal conductivity of a portion of the furnace core tube located directly next to the crucible in a radial direction thereof is higher than a thermal conductivity of the furnace inner tube.

The invention provides a growth method for preparing high-yield crystals, belongs to the technical field of single crystal growth. Auxiliary crucibles are arranged on a crucible according to different crystal types and according to the crystal orientation of crystal growth in the main crucible, the relationship between the crystal growth direction and twin crystal orientation. By controlling the angle between the auxiliary crucibles and the main crucible, the relative position between the auxiliary crucibles each other, the auxiliary crucibles realize correction on the crystal orientation of twins generated in the main crucible crystal growth process. The growth method for preparing the high-yield crystals provided by the invention has the following advantages: the crystal orientation change caused by twins is corrected through auxiliary crucibles additionally arranged on the main crucible, and the overall yield is improved for the growth process of the dislocation crystal with large probability; the crucible position can be customized according to the influence of twins on the crystal growth direction, suitable for various crystal preparation processes, improving the yield obviously, reducing the crystal processing difficulty, and improving the material utilization rate.

A poly-crystalline silicon ingot having a bottom and defining a vertical direction includes a plurality of silicon grains grown in the vertical direction, in which the plurality of the silicon grains have at least three crystal orientations; and a nucleation promotion layer comprising a plurality of chips and chunks of poly-crystalline silicon on the bottom, wherein the poly-crystalline silicon ingot has a defect density at a height ranging from about 150 mm to about 250 mm of the poly-crystalline silicon ingot that is less than 15%.

Methods and devices for detecting incident radiation are provided. The methods and devices use high quality single-crystals of photoactive semiconductor compounds in combination with metal anodes and metal cathodes that provide for enhanced photodetector performance.

The gallium arsenide single crystal substrate has a circular main surface, and when the diameter of the main surface of the gallium arsenide single crystal substrate is represented by D and the number of etch pits formed on the main surface by immersing the gallium arsenide single crystal substrate in molten potassium hydroxide at 500° C. for 10 minutes is counted, the number C.sub.1 of etch pits in a first circular region having a diameter of 0.2D around the center of the main surface is 0 or more and 10 or less.

The invention provides a growth method for preparing high-yield crystals, belongs to the technical field of single crystal growth. Auxiliary crucibles are arranged on a crucible according to different crystal types and according to the crystal orientation of crystal growth in the main crucible, the relationship between the crystal growth direction and twin crystal orientation. By controlling the angle between the auxiliary crucibles and the main crucible, the relative position between the auxiliary crucibles each other, the auxiliary crucibles realize correction on the crystal orientation of twins generated in the main crucible crystal growth process. The growth method for preparing the high-yield crystals provided by the invention has the following advantages; the crystal orientation change caused by twins is corrected through auxiliary crucibles additionally arranged on the main crucible, and the overall yield is improved for the growth process of the dislocation crystal with large probability; the crucible position can be customized according to the influence of twins on the crystal growth direction, suitable for various crystal preparation processes, improving the yield obviously, reducing the crystal processing difficulty, and improving the material utilization rate.

A single-crystal turbine blade and a method of making such single-crystal turbine blade are disclosed. During manufacturing, a secondary crystallographic orientation of the material of the single-crystal turbine blade is controlled based on a parameter of a root fillet between an airfoil of the single-crystal turbine blade and a platform of the single-crystal turbine blade. The parameter can be a location of peak stress in the root fillet expected during use of the turbine blade.

Methods and devices for detecting incident radiation are provided. The methods and devices use high quality single-crystals of photoactive semiconductor compounds in combination with metal anodes and metal cathodes that provide for enhanced photodetector performance.