The present invention relates to an apparatus and method for purifying materials using a rapid directional solidification. Devices and methods shown provide control over a temperature gradient and cooling rate during directional solidification, which results in a material of higher purity. The apparatus and methods of the present invention can be used to make silicon material for use in solar applications such as solar cells.

A method and apparatus for growing truly bulk In.sub.2O.sub.3 single crystals from the melt, as well as melt-grown bulk In.sub.2O.sub.3 single crystals are disclosed. The growth method comprises a controlled decomposition of initially non-conducting In.sub.2O.sub.3 starting material (23) during heating-up of a noble metal crucible (4) containing the In.sub.2O.sub.3 starting material (23) and thus increasing electrical conductivity of the In.sub.2O.sub.3 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 In.sub.2O.sub.3. Such coupling leads to an electromagnetic levitation of at least a portion (23.1) of the liquid In.sub.2O.sub.3 starting material with a neck (26) formation acting as crystallization seed. During cooling down of the noble metal crucible (4) with the liquid In.sub.2O.sub.3 starting material at least one bulk In.sub.2O.sub.3 single crystal (28.1, 28.2) is formed. We named this novel crystal growth method the Levitation-Assisted Self-Seeding Crystal Growth Method. The apparatus for growing bulk In.sub.2O.sub.3 single crystals from the melt comprises an inductively heated thermal system with a noble metal crucible (4) and evacuation passages (22, 22.1) for gaseous decomposition products of In.sub.2O.sub.3, while keeping very low temperature gradients. Various configurations of the induction coil (6), the noble metal crucible (4) and a lid (12) covering the crucible can be utilized to obtain very low temperature gradients, sufficient evacuation passages and a high levitation force. The electrical properties of the melt grown In.sub.2O.sub.3 single crystals can be modified in a wide range by at least one heat treatment in suitable atmospheres and appropriate temperatures.

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 input 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. An aerosol of catalyst particles may be used to grow the nanowires.

A single-crystal production equipment includes a transparent quartz tube, in which a seed crystal is placed; a powder raw material supply apparatus, which is arranged above the transparent quartz tube and supplies a powder raw material onto the seed crystal placed in the transparent quartz tube; and an infrared ray irradiation apparatus, which is arranged outside the transparent quartz tube and applies an infrared ray to the upper surface of the seed crystal placed in the transparent quartz tube as well as the powder raw material supplied into the transparent quartz tube by the powder raw material supply apparatus. The infrared ray melts the upper surface of the seed crystal and the powder raw material and subsequently the resulting melt solidifies on the seed crystal to provide a single crystal.

An apparatus for forming a crystalline sheet. The apparatus may include a crystallizer comprising a first gas channel and a second gas channel, wherein the first gas channel and second gas channel extend through the crystallizer to a lower surface of the crystallizer between an upstream edge and a downstream edge. The first gas channel may be disposed closer to the downstream edge than the second gas channel. A first gas source may be coupled to the first gas channel, where the first gas source comprises helium or hydrogen, and a second gas source may be coupled to the second gas channel, where the second gas source does not contain hydrogen or helium.

The invention relates to a method for producing a component by means of layered construction, by combining a plurality of crystallites of a metallic material to form a single crystal. The single crystal is formed by thermomechanically activated successive anisotropic plastic deformation. The metallic material is heated during the construction of a new layer, with the result that the metallic material is melted in a linear region. The linear region is moved in order to construct the new layer.

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.

An investment casting apparatus includes a furnace having an opening, a mold support, and a multi-axis actuator connected with the mold support and configured to retract the mold support from the opening with multiple-axis motion. An investment casting method includes withdrawing, with multiple-axis motion, a mold through the opening of the furnace to solidify a molten metal- or metalloid-based material in the mold. The apparatus and method can be used to form a cast article that has a body formed of the metal- or metalloid-based material. The body has a multi-textured, single crystal microstructure.

Disclosed is a method for melting and solidification of a scintillating material in micromechanical structures, including controlling the melting and solidification of the scintillating material by individually controlled heat sources, a top heater and a bottom heater, placed above and below a process chamber, housing a sample with the micromechanical structures and the scintillating material. The heaters are controlled to set a vertical temperature gradient over the sample to control the melting and solidification of the scintillating material. During melting, the top heater is ramped up and stabilized at a temperature where no melting occurs and the bottom heater is ramped up and stabilized at a temperature where melting occurs during a period of time while the scintillating material melts and flows into the micromechanical structures. During solidification, the temperature of the bottom heater decreases to enable solidification to take place starting from the bottom of the micromechanical structures.

A crystalline silicon ingot and a method of fabricating the same are disclosed. The crystalline silicon ingot of the invention includes multiple silicon crystal grains growing in a vertical direction of the crystalline silicon ingot. The crystalline silicon ingot has a bottom with a silicon crystal grain having a first average crystal grain size of less than about 12 mm. The crystalline silicon ingot has an upper portion, which is about 250 mm away from said bottom, with a silicon crystal grain having a second average crystal grain size of greater than about 14 mm.