Abstract: The present invention relates to a method for producing high purity silicon comprising providing molten silicon containing 1-10% by weight of calcium, casting the molten silicon, crushing the silicon and subjecting the crushed silicon to a first leaching step in an aqueous solution of HCl and/or HCl+FeCl3 and to a second leaching step in an aqueous solution of HF and HNO3. The leached silicon particles is thereafter subjected to heat treatment at a temperature of between 1250° C. and 1420° C. for a period of at least 20 minutes and the heat treated silicon is subjected to a third leaching step in an aqueous solution of HF and HNO3.

Abstract: The present invention relates to an apparatus for continuous treatment of two immiscible molten liquids having different densities. The apparatus comprises at least one open-ended helical reaction channel (3) arranged inside a substantially vertical housing (1), means for the continuous supply of the liquid with the higher density to the upper open end of said at least one reaction channel (3) and means for continuous supply of the liquid with the lower density to the lower open end of said at least one helical reaction channel (3), means for continuous removal of the liquid with the higher density at the lower open end of said helical reaction channel and means for removal of the liquid with the lower density from the upper open end of said helical reaction channel (3). The invention further relates to a method for continuous treatment of two immiscible molten liquids having different densities using the apparatus of the present invention.

Abstract: The present invention relates to multicrystalline p-type silicon wafers with high lifetime. The silicon wafers contain 0.2-2.8 ppma boron and 0.06-2.8 ppma phosphorous and/or arsenic and have been subjected to phosphorous diffusion and phosphorous gettering at a temperature of above 925° C. The invention further relates to a method for production of such multicrystalline silicon wafers and to solar cells comprising such silicon wafers.

Abstract: The method and apparatus includes a vessel having a bottom and sidewalls arranged to house the material in a molten state. A temperature controlled horizontally oriented, cooling plate is movable into and out of the top of the molten material. When the cooling plate is lowered into the top of the melt, an ingot of solid silicon is solidified downwards.

Abstract: The present invention relates to a method for production of calcium compounds having very low content of phosphorus and boron from an impure calcium chloride, solution containing phosphorus and boron, which method comprises the following steps: a) addition of a FeCl3-solution to the calcium chloride solution, b) adjusting the pH of the solution by addition of a base to between 3 and 9.5 for precipitation of iron hydroxide, iron phosphate and boron compounds, c) removal of the solid precipitate from the solution in step b) obtaining a purified calcium chloride solution, d) precipitation of a calcium compound from the solution from step c), and e) separation of the calcium compound from the solution in step d).

Abstract: A coating system for a mould for the directional solidification of silicon. The coating is applied as an aqueous slurry of silicon nitride particle, carbon black and microsilica.

Abstract: The present invention relates to an apparatus for continuous treatment of two immiscible molten liquids having different densities. The apparatus comprises at least one open-ended helical reaction channel (3) arranged inside a substantially vertical housing (1), means for the continuous supply of the liquid with the higher density to the upper open end of said at least one reaction channel (3) and means for continuous supply of the liquid with the lower density to the lower open end of said at least one helical reaction channel (3), means for continuous removal of the liquid with the higher density at the lower open end of said helical reaction channel and means for removal of the liquid with the lower density from the upper open end of said helical reaction channel (3). The invention further relates to a method for continuous treatment of two immiscible molten liquids having different densities using the apparatus of the present invention.

Abstract: The present invention relates to a method for producing high purity silicon comprising providing molten silicon containing 1-10% by weight of calcium, casting the molten silicon, crushing the silicon and subjecting the crushed silicon to a first leaching step in an aqueous solution of HCl and/or HCl+FeCl3 and to a second leaching step in an aqueous solution of HF and HNO3. The leached silicon particles is thereafter subjected to heat treatment at a temperature of between 1250° C. and 1420° C. for a period of at least 20 minutes and the heat treated silicon is subjected to a third leaching step in an aqueous solution of HF and HNO3.

Abstract: The present invention relates to a method for production of silane where particulate quartz in a fluidized bed is treated with a gas containing hydrogen at a temperature below 0° C., with the quartz in the fluidized bed subjected to an alternating electric field having a frequency equal to the intrinsic resonant frequency of at least a part of the quartz particles to create vibrational energy in the particles, thereby causing a chemical reaction between quartz and hydrogen to produce silane. The invention also relates to an apparatus for carrying out the method.

Abstract: The present invention relates to a method for production of calcium compounds having very low content of phosphorus and boron from an impure calcium chloride, solution containing phosphorus and boron, which method comprises the following steps: a) addition of a FeCl3-solution to the calcium chloride solution, b) adjusting the pH of the solution by addition of a base to between 3 and 9.5 for precipitation of iron hydroxide, iron phosphate and boron compounds, c) removal of the solid precipitate from the solution in step b) obtaining a purified calcium chloride solution, d) precipitation of a calcium compound from the solution from step c), and e) separation of the calcium compound from the solution in step d).

Abstract: The present invention relates to multicrystalline p-type silicon wafers with high lifetime. The silicon wafers contain 0.2-2.8 ppma boron and 0.06-2.8 ppma phosphorous and/or arsenic and have been subjected to phosphorous diffusion and phosphorous gettering at a temperature of above 925° C. The invention further relates to a method for production of such multicrystalline silicon wafers and to solar cells comprising such silicon wafers.

Abstract: A coating system for a mould for the directional solidification of silicon. The coating is applied as an aqueous slurry of silicon nitride particle, carbon black and microsilica.

Abstract: A method for the directional solidification of silicon or other materials. A cooled plate is lowered into a silicon melt and an ingot of solid silicon is solidified downwards.

Abstract: A method for the directional solidification of silicon or other materials.

Abstract: The present invention relates to a method for the production of directionally solidified Czochralski, float zone or multicrystalline silicon ingots or thin sheets or ribbon for making wafers for solar cells from silicon feedstock initially containing between 0.2 ppma and 10 ppma boron and between 0.1 ppma and 10 ppma phosphorous. If the boron content in the silicon feedstock is higher than the phosphorous content, the boron content in the molten silicon is kept higher than the phosphorous content during the directional solidification process by adding boron to the molten silicon in order to extend the part of the directionally solidified ingot or the thin sheet or ribbon solidifying as p-type material.