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 a 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.

The present invention relates to an orthogonal-phase compound and its nonlinear optical (NLO) crystal of BaGa.sub.7Se.sub.7, its producing method and uses thereof. Polycrystalline orthogonal-phase BaGa.sub.4Se.sub.7 was prepared by a high-temperature solid-phase reaction in a sealed silica tube. Large size single crystals of orthogonal-phase BaGa.sub.4Se.sub.7 could be prepared by the flux method or Bridgman method. BaGa.sub.4Se.sub.7 crystallizes in the point group mm2. Orthogonal-phase BaGa.sub.4Se.sub.7 has a powder second harmonic generation (SHG) efficiency of about 5 times that of AgGaS.sub.2 and is phase-matchable. The orthogonal-phase BaGa.sub.4Se.sub.7 is non-hygroscopic and has good mechanical properties, which makes it easy to cut, polish, and coat by normal processing. The orthogonal-phase BaGa.sub.4Se.sub.7 crystal has never been cracked during cutting and polishing. The orthogonal-phase compound and NLO crystal of BaGa.sub.4Se.sub.7 can be used as NLO devices.

A stirring apparatus of an ingot casting furnace includes a rotating shaft and at least one fin. The fin is provided onto the rotating shaft, and has a first edge, a second edge of unequal length provided correspondingly, and a third edge connecting the first and the second edges. The rotating shaft can be driven to rotate, which consequently drives the at least one fin to stir materials in a crucible. The length of the first edge is different from that of the second edge in order for the materials in the crucible can be mixed with dopants more uniformly during the stirring process to produce ingots of stable quality.

A method of growing a zirconia single crystal includes preparing a mixture of ZrO.sub.2 and Y.sub.2O.sub.3 for growing the zirconia single crystal, charging the raw material and a melting seed in a skull crucible for growing the zirconia single crystal using a high-frequency induction heating device, supplying power to the high-frequency induction heating device to melt the raw material, maintaining an output power of the high-frequency induction heating device to soak the melted raw material, first-elevating an induction coil of the high-frequency induction heating device to produce a seed, second-elevating the induction coil of the high-frequency induction heating device to grow a single crystal, cutting off power to the high-frequency induction heating device when completing growth of the zirconia single crystal, and cooling the zirconia single crystal. The method has excellent physical properties free from low-temperature degradation and thus enables precise machining.

A pressure differential can be applied across a mold sheet and a semiconductor (e.g. silicon) wafer (e.g. for solar cell) is formed thereon. Relaxation of the pressure differential can allow release of the wafer. The mold sheet may be cooler than the melt. Heat is extracted through the thickness of the forming wafer. The temperature of the solidifying body is substantially uniform across its width, resulting in low stresses and dislocation density and higher crystallographic quality. The mold sheet can allow flow of gas through it. The melt can be introduced to the sheet by: full area contact with the top of a melt; traversing a partial area contact of melt with the mold sheet, whether horizontal or vertical, or in between; and by dipping the mold into a melt. The grain size can be controlled by many means.

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.

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.

A crystal growth device and method with temperature gradient control, which relate to the field of semiconductor, optical crystals and metal crystal preparation. The crystal growth device comprises a crucible and a matching assembly, a melt temperature gradient control mechanism, and a crystal temperature gradient control mechanism, wherein the melt temperature gradient control mechanism is arranged inside the crucible, and comprises a lifting rod and a heating plate; and the crystal temperature gradient control mechanism comprises a constant-temperature water cooler and a cold water circulation pipeline. The growth method comprises: during crystal growth, gradually increasing water supply flow of the constant-temperature water cooler up to 30 L/min; and lifting the melt temperature gradient control mechanism at a lifting speed of 2-5 mm/h. A movable heating device is provided in a melt, such that the temperature gradient in the melt can be improved by precisely controlling the position and temperature of the heating device. The precise flow of cooling water at a substantially constant temperature is introduced into a crucible rod to control the temperature gradient of a seed crystal, so as to achieve crystal growth with high quality and high yield.