Methods and wafers for low etch pit density, low slip line density, and low strain indium phosphide are disclosed and may include an indium phosphide single crystal wafer having a diameter of 4 inches or greater, having a measured etch pit density of less than 500 cm.sup.−2, and having fewer than 5 dislocations or slip lines as measured by x-ray diffraction imaging. The wafer may have a measured etch pit density of 200 cm.sup.−2 or less, or 100 cm.sup.−2 or less, or 10 cm.sup.−2 or less. The wafer may have a diameter of 6 inches or greater. An area of the wafer with a measured etch pit density of zero may at least 80% of the total area of the surface. An area of the wafer with a measured etch pit density of zero may be at least 90% of the total area of the surface.

A gas phase nanowire growth apparatus including a reaction chamber, a first input and a second input. The first input is located concentrically within the second input and the first and second input are configured such that a second fluid delivered from the second input provides a sheath between a first fluid delivered from the first input and a wall of the reaction chamber.

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).

A method of method of forming or repairing a superalloy article having a columnar or equiaxed or directionally solidified or amorphous or single crystal microstructure includes emitting a plurality of laser beams from selected fibers of a diode laser fiber array corresponding to a pattern of a layer of the article onto a powder bed of the superalloy to form a melt pool; and controlling a temperature gradient and a solidification velocity of the melt pool to form the columnar or single crystal microstructure.

Provided is a cadmium zinc telluride (CdZnTe) single crystal including a main surface that has a high mobility lifetime product (μτ product) in a wide range, wherein the main surface has an area of 100 mm.sup.2 or more and has 50% or more of regions where the μτ product is 1.0×10.sup.−3 cm.sup.2/V or more based on the entire main surface, and a method for effectively producing the same.

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 110.sup.7 -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 m or greater. Electronic devices may be formed on a first surface of the wafer. The wafer may have a carrier concentration of 1.110.sup.7 cm.sup.3 or less.

A gas phase nanowire growth apparatus including a reaction chamber, a first input and a second input. The first input is located concentrically within the second input and the first and second input are configured such that a second fluid delivered from the second input provides a sheath between a first fluid delivered from the first input and a wall of the reaction chamber.

Methods and wafers for vertical gradient freeze 8 inch gallium arsenide (GaAs) substrates. In disclosed examples, vertical gradient freeze systems for forming gallium arsenide (GaAs) substrates having silicon as a dopant, the system includes a crucible to contain a GaAs liquid melt and seed material during a formation process; one or more heating coils arranged in a plurality of heating zones; and a pedestal to move relative to the crucible, the system operable to control heating of the plurality of heating zones and movement of the pedestal to form a single crystal GaAs substrate.

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.