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.

A method and apparatus for measuring a melt back of a seed in a boule are provided. The method includes lifting a boule once it has been produced using an actuating device onto a support table to automatically manipulate the boule from a furnace to the support table. The melt back of the seed is then automatically measured using a vision system that is installed on an imaging device disposed below the boule.

The invention discloses a device and a method for continuous VGF crystal growth through reverse injection synthesis, relating to a device for preparing a semiconductor crystal and growing a single crystal, in particular to a method and a device for continuously growing the crystal in situ by using a VGF method and reverse injection synthesis. The device includes a furnace body, a crucible, a heat preservation system, a heating system, a temperature control system and an gas pressure regulation system, wherein the crucible is arranged in the furnace body, has a synthesis unit at its upper part, and has a crystal growth unit and a seed crystal unit at its lower part, and the synthesis unit is communicated with the crystal growth unit through capillary pores. Red phosphorus and boron oxide are put into the growth unit, indium and boron oxide are put into the synthesis unit, solid seed crystals are put into the seed crystal unit, and temperature and pressure are controlled to accomplish material synthesis and in-situ crystal growth. According to the invention, the capillary pores are used, the temperature and the pressure are controlled, the phosphorus bubbles rise to the indium melt in the material synthesis stage, rendering a full fusion of the two substances, and after the phosphorus gasification, the indium-phosphorus melt drops into the growth unit to finish the in-situ growth of the crystal.

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.

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.

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 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.

A method and apparatus for measuring a melt back of a seed in a boule are provided. The method includes lifting a boule once it has been produced using an actuating device onto a support table to automatically manipulate the boule from a furnace to the support table. The melt back of the seed is then automatically measured using a vision system that is installed on an imaging device disposed below the boule.

The apparatus for producing a gallium oxide crystal relating to the invention contains a vertical Bridgman furnace containing: a base body; a cylindrical furnace body having heat resistance disposed above the base body; a lid member occluding the furnace body; a heater disposed inside the furnace body; a crucible shaft provided vertically movably through the base body; and a crucible disposed on the crucible shaft, heated with the heater, the crucible is a crucible containing a Pt-based alloy, the furnace body has an inner wall that is formed as a heat-resistant wall containing plural ring shaped heat-resistant members each having a prescribed height accumulated on each other, and the ring shaped heat-resistant members each contain plural divided pieces that are joined to each other to the ring shape.

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.