1942results about "Silicon" patented technology

A process for depositing polycrystalline silicon on substrates, including foreign substrates, occurs in a chamber at about atmospheric pressure, wherein a temperature gradient is formed, and both the atmospheric pressure and the temperature gradient are maintained throughout the process. Formation of a vapor barrier within the chamber that precludes exit of the constituent chemicals, which include silicon, iodine, silicon diiodide, and silicon tetraiodide. The deposition occurs beneath the vapor barrier. One embodiment of the process also includes the use of a blanketing gas that precludes the entrance of oxygen or other impurities. The process is capable of repetition without the need to reset the deposition zone conditions.

A silicon production reactor comprising a reaction vessel and heating means, said reaction vessel comprising a vertically extending wall and a space surrounded by the wall, said heating means being capable of heating at least a part, including lower end portion, of the wall's surface facing the space to a temperature of not lower than the melting point of silicon, said silicon production reactor being adapted to flow raw gas for silicon deposition from an upper part of the space of the reaction vessel toward a lower part thereof, characterized in that the space of the reaction vessel is of slit form in cross-sectional view. This silicon production reactor is capable of attaining improvement with respect to problems encountered at apparatus scaleup, such as decrease of reactivity of raw gas and generation of by-products, thereby accomplishing a striking enhancement of production efficiency.

System and methods for processing an amorphous silicon thin film sample into a single or polycrystalline silicon thin film are disclosed. The system includes an excimer laser for generating a plurality of excimer laser pulses of a predetermined fluence, an energy density modulator for controllably modulating fluence of the excimer laser pulses, a beam homoginizer for homoginizing modulated laser pulses in a predetermined plane, a mask for masking portions of the homoginized modulated laser pulses into patterned beamlets, a sample stage for receivingthe patterned beamlets to effect melting of portions of any amorphous silicon thin film sample placed thereon corresponding to the beamlets, translating means for controllably translating a relative position of the sample stage with respect to a position of the mask and a computer for controlling the controllable fluence modulation of the excimer laser pulses and the controllable relative positions of the sample stage and mask, and for coordinating excimer pulse generation and fluence modulation with the relative positions of the sample stage and mask, to thereby process amorphous silicon thin film sample into a single or polycrystalline silicon thin film by sequential translation of the sample stage relative to the mask and irradiation of the sample by patterned beamlets of varying fluence at corresponding sequential locations thereon.

A radiation-heated fluidized-bed reactor and a process for producing high-purity polycrystalline silicon by using this reactor are provided. In this reactor, a heater device (14) is a radiation source for thermal radiation which is arranged outside the inner reactor tube and as a cylinder around the heater zone, without being in direct contact with the inner reactor tube. The inner reactor tube is designed in such a manner that it uses thermal radiation to heat the silicon particles in the heating zone to a temperature which is such that the reaction temperature is established in the reaction zone.

A porous silicon based material comprising porous crystalline elemental silicon formed by reducing silicon dioxide with a reducing metal in a heating process followed by acid etching is used to construct negative electrode used in lithium ion batteries. Gradual temperature heating ramp(s) with optional temperature steps can be used to perform the heating process. The porous silicon formed has a high surface area from about 10 m²/g to about 200 m²/g and is substantially free of carbon. The negative electrode formed can have a discharge specific capacity of at least 1800 mAh/g at rate of C/3 discharged from 1.5V to 0.005V against lithium with in some embodiments loading levels ranging from about 1.4 mg/cm² to about 3.5 mg/cm². In some embodiments, the porous silicon can be coated with a carbon coating or blended with carbon nanofibers or other conductive carbon material.

Disclosed are a carbon nanotube-coated silicon/metal composite particle, a preparation method thereof, an anode for a secondary battery comprising the carbon nanotube-coated silicon/metal composite particle, and a secondary battery comprising the anode, wherein the carbon nanotube-coated silicon/metal composite particle characterized in comprising: a composite particle of silicon and metal; and a carbon nanotube coated on the surface of the composite particle of silicon and metal, wherein the carbon nanotube-coated silicon/metal composite particle may be prepared by preparing composite particle of silicon and metal, followed by treating the composite particles of silicon and metal with heat under a mixed gas atmosphere of an inert gas and a hydrocarbon gas.

Composite compounds of tin and lithium, silicon and lithium, or tin, silicon, and lithium having tin and silicon nano-dispersed in a lithium-containing matrix may be used as electrode materials and particularly anode materials for use with rechargeable batteries. Methods of making the composite compounds include the oxidation of alloys, the reaction of stabilized lithium metal powder with tin and silicon oxides, and the reaction of inorganic salts of lithium with tin and silicon containing compounds.

A metallic silicon powder is prepared by effecting chemical reduction on silica stone, metallurgical refinement, and metallurgical and/or chemical purification to reduce the content of impurities. The powder is best suited as a negative electrode material for non-aqueous electrolyte secondary cells, affording better cycle performance.

A silicon casting apparatus for producing polycrystal silicon ingot by heating a silicon melt (8) held in a mold (4) from above by a heater (3) and cooling it from below while changing the heat exchange area of a heat exchange region (HE), defined between a pedestal (5) having the mold (4) placed thereon and a bottom cooling member (6), in such a manner as to keep pace with the rise of the solid-liquid interface of the silicon melt (8), thereby causing unidirectional solidification upward along the mold (4); and a method of producing polycrystal silicon ingot using such apparatus. According to this production method, the temperature gradient given to the silicon melt (8) can be maintained at constant by adjusting the heat exchange area, so that polycrystal silicon ingot having good characteristics can be produced with good reproducibility.

A method of creating thin wafers of single crystal silicon wherein an ingot of single-crystal silicon with a (111) axis is flattened and polished at one end normal to the axis, and a notch with a vertex in the (111) plane is produced on a side or edge of the ingot, such that the distance between this vertex and said end is the desired thickness of a wafer to be cleaved from the ingot and such this vertex is in the desired plane of cleavage. Light of a wavelength able to penetrate into the silicon crystal without significant absorption, when the intensity of the beam is low, but is efficiently absorbed and converted to heat when the intensity of the beam is high, is focused to an elongated volume with an axis of elongation in the desired cleavage plane, parallel to and a short distance from said notch edge. Heating and the resulting transient local expansion of the silicon in this illuminated volume causes tensile stress at the vertex of said notch, substantially normal to the desired cleavage plane, thereby causing fracture of the crystal in the chosen cleavage plane. Movement of the illuminated volume relative to the ingot allows the fracture to propagate across the desired cleavage plane, thereby completely severing the wafer from the rest of the ingot.

Silicon based anode active materials are described for use in lithium ion batteries. The silicon based materials are generally composites of nanoscale elemental silicon with stabilizing components that can comprise, for example, silicon oxide-carbon matrix material, inert metal coatings or combinations thereof. High surface area morphology can further contribute to the material stability when cycled in a lithium based battery. In general, the material synthesis involves a significant solution based processing step that can be designed to yield desired material properties as well as providing convenient and scalable processing.

Gas distribution units of fluidized bed reactors are configured to direct thermally decomposable compounds to the center portion of the reactor and away from the reactor wall to prevent deposition of material on the reactor wall and process for producing polycrystalline silicon product in a reactor that reduce the amount of silicon which deposits on the reactor wall.

Silicon nanosponge particles prepared from a metallurgical grade silicon powder having an initial particle size ranging from about 1 micron to about 4 microns is presented. Each silicon nanosponge particle has a structure comprising a plurality of nanocrystals with pores disposed between the nanocrystals and throughout the entire nanosponge particle.

In a manufacturing method of a conductive composite particle, a conductive composite particle is manufactured that is formed of an active material particle having a region capable of electrochemically inserting and desorbing lithium and a carbon layer joined to the particle surface. In the carbon layer, fine metal particles are dispersed. This method has the following three steps. In the first step, a polymer material containing the metal element composing the fine metal particles is prepared. In the second step, the active material particle surface is coated with the polymer material containing the metal element. In the third step, a carbon layer having a porous structure including a fibrous structure is formed as the surface layer section from the polymer material by a treatment where the active material particle coated with the polymer containing the metal element is heated in an inert atmosphere to carbonize the polymer material.

A process for preparing granular polysilicon using a fluidized bed reactor is disclosed. The upper and lower spaces of the bed are defined as a reaction zone and a heating zone, respectively, with the height of the reaction gas outlet being selected as the reference height. The invention maximizes the reactor productivity by sufficiently providing the heat required and stably maintaining the reaction temperature in the reaction zone, without impairing the mechanical stability of the fluidized bed reactor. This is achieved through electrical resistance heating in the heating zone where an internal heater is installed in a space in between the reaction gas supplying means and the inner wall of the reactor tube, thereby heating the fluidizing gas and the silicon particles in the heating zone. The heat generated in the heating zone is transferred to the reaction zone by supplying the fluidizing gas at such a rate that the silicon particles can be intermixed between the reaction zone and the heating zone in a continuous, fluidized state.

A metallic silicon-containing composite in which metallic silicon nuclei are coated with an inert material which does not contribute to adsorption and desorption of lithium ions is a useful negative electrode material for lithium ion secondary batteries. Using the composite as a negative electrode active material, a lithium ion secondary battery having a high capacity and excellent cycle performance can be fabricated.

The invention relates to the production of bulky monocrystalline metal or semi-metal bodies, in particular of a monocrystalline Si ingot, using the vertical gradient freeze (VGF) method by directional solidification of a melt in a melting crucible having a polygonal basic shape.

According to the invention, the entire bottom of the melting crucible is completely covered with a thin seed crystal plate made of the monocrystalline semi-metal or metal. Throughout the procedure, the bottom of the melting crucible is kept below the melting temperature of the semi-metal or metal in order to prevent melting of the seed crystal plate.

Monocrystalline ingots produced in this way are distinguished by a low average dislocation density of for example less than 10⁵ cm⁻², allowing the production of very efficient monocrystalline Si solar cells.

Method for producing highly purified silicon for use in solar cells by a single solidification purification, pouring silicon into a mold and gradually fractionally solidifying it while solidifying the liquid surface, followed by purifying the solidified silicon by zone melting or continuous casting using an electromagnetic mold, or by zone melting in combination with continuous casting, and optionally causing directional solidification to concentrate impurities, leaching and recycling.

Polysilicon is formed by pyrolytic decomposition of a silicon-bearing gas and deposition of silicon onto fluidized silicon particles. Multiple submerged spout fluidized bed reactors and reactors having secondary orifices are disclosed.

The invention belongs to the technical field of preparing the surface of a composite structure, and in particular relates to a method for preparing super-hydrophobic antireflective silicon surface with a micron and nanometer composite structure. The method comprises the following steps: cleaning a silicon chip; preparing a micron-level silicon island and a gridding structure on the surface of the silicon chip; carrying out catalytic etching taking silver or aurum nanoparticles as blockage; obtaining the surface of the micron and nanometer composite structure; and carrying out chemical modification of the surface of the composite structure. A static contact angle between the super-hydrophobic antireflective material surface prepared by the method and water is more than 150 degrees, and a static rolling angle of water is less than 3 degrees. The surface has superior antireflective performance, and in particular, the light reflectivity within the wavelength range between 800 and 1,100 nm is less than 3 percent. With application of the method, the super-hydrophobic antireflective silicon surface of the micron and nanometer composite structure can be produced on scale, can be widely applied to a solar cell, a microfluidic chip, a photoelectric device, and the like, and has good industrial application prospect.