Abstract: A method and system for reduction or mitigation of metal contamination of polycrystalline silicon are disclosed. Metal contamination of granulate polycrystalline silicon, from contact with a metal surface of components of the supporting transportation and auxiliary infrastructure of a fluidized bed reactor unit, is mitigated by use of a protective coating comprising a microcellular elastomeric polyurethane.

Abstract: Embodiments of a method for reducing iron silicide and/or iron phosphide fouling and/or corrosion in a hydrochlorosilane production plant are disclosed. Sufficient trichlorosilane is included in a silicon tetrachloride process stream to minimize hydrogen chloride formation, thereby inhibiting iron (II) chloride formation and reducing iron silicide and/or iron phosphide fouling, superheater corrosion, or a combination thereof.

Abstract: Fluidized bed reactor systems for producing high purity silicon-coated particles are disclosed. A vessel has an outer wall, an insulation layer inwardly of the outer wall, at least one heater positioned inwardly of the insulation layer, a removable concentric liner inwardly of the heater, a central inlet nozzle, a plurality of fluidization nozzles, at least one cooling gas nozzle, and at least one product outlet. The system may include a removable concentric sleeve inwardly of the liner. In particular systems the central inlet nozzle is configured to produce a primary gas vertical plume centrally in the reactor chamber to minimize silicon deposition on reactor surfaces.

Abstract: An improved process for producing a crystalline silicon ingot, a crystalline silicon wafer and a photovoltaic cell using the directional solidification process, and more particularly to loading and preparing a mold for the process of directional solidification. At least one rod polysilicon section and at least one chunk polysilicon, chip polysilicon or granular polysilicon is loaded into the mold, increasing packing density and thermal conductivity of the polysilicon contents while reducing contamination and resources expended to process a production cycle.

Abstract: Polysilicon dendrites are grown by depositing silicon on a polysilicon rod or other substrate. Surface temperature is increased to a temperature at which needle-like dendrites develop due to the deposition of silicon from silicon-containing molecules in the surrounding reactor atmosphere. Thereafter, the surface temperature is gradually reduced so that silicon that deposits on the needle-like dendrites causes the dendrites to grow and assume a generally flared shape.