Abstract: The present invention is for the recovery of maximum silicon value of kerf silicon waste, produced during the manufacture of silicon wafers by wire saw, diamond saw and chemical mechanical polishing, as high purity metallurgical silicon. This recovery is achieved by a process scheme that effects an initial removal of minor extrinsic metallic impurities but not the major silicon compound impurities, and followed, preferentially, by a direct metallurgical process to form elemental silicon. The recovered silicon is for use as feedstock for polysilicon manufacturing, as high purity polysilicon for PV application, and in metallurgical alloy manufacture.

Abstract: The present invention is directed towards an integrated and economic process for making mono-crystalline silicon for photovoltaic applications. It utilizes high purity, low dopant metallurgically produced silicon, in particular, silicon recovered from silicon manufacturing processes, such as kerf silicon processed through a metallurgical furnace process. Liquid silicon from the metallurgical process is cast into specific forms and utilized for float zone purification and crystallization to make mono-crystalline silicon ingots and wafers for photovoltaic cell fabrication.

Abstract: This application describes a bulk and thin film chemical vapor deposition (CVD) process using lasers to heat a silicon substrate to the required deposition temperature. It is primarily applicable to production of polysilicon by the decomposition of halosilanes in a chemical reactor. It is also suitable for other materials that use a CVD process to deposit material on a heated silicon substrate.

Abstract: The present invention relates to a direct method to convert fine and ultra fine silicon powder from polysilicon manufacturing sources such as fluid bed and free space reactors into densified granular forms. This conversion process is effected by the use of lasers of selective wavelengths from solid state diode or optically-pumped YAG sources to locally heat, melt and densify a controlled quantity of silicon powder, and comprises the steps of distributing dry silicon powder on an inert substrate, subjecting the silicon charge to a focused laser beam to realize melted and densified granular forms, and discharging the product. When adapted to high purity silicon powder, the end use for the densified silicon granular forms is primarily as feedstock for silicon-based semiconductor and photovoltaic manufacturing industries. The process, suitably modified, is adaptable to form other silicon body shapes and components.

Abstract: The present invention relates to a direct method to convert fine and ultra fine silicon powder from polysilicon manufacturing sources such as fluid bed and free space reactors into densified granular forms. This conversion process is effected by the use of lasers of selective wavelengths from solid state diode or optically-pumped YAG sources to locally heat, melt and densify a controlled quantity of silicon powder, and comprises the steps of distributing dry silicon powder on an inert substrate, subjecting the silicon charge to a focused laser beam to realize melted and densified granular forms, and discharging the product. When adapted to high purity silicon powder, the end use for the densified silicon granular forms is primarily as feedstock for silicon-based semiconductor and photovoltaic manufacturing industries. The process, suitably modified, is adaptable to form other silicon body shapes and components.

Abstract: A process for the recovery of silicon includes providing silicon-containing solids recovered from a silicon manufacturing process, said recovered silicon-containing solids being substantially free of semiconductor dopants; converting the recovered silicon-containing solids into gaseous silicon forms; subjecting to purification by minimal distillation; collecting the gaseous silicon forms as a condensed liquid of silicon-containing compounds; and utilizing the silicon-containing compounds for silicon deposition.

Abstract: A process for the recovery of silicon includes providing silicon-containing solids recovered from a silicon manufacturing process, said recovered silicon-containing solids being substantially free of semiconductor dopants; converting the recovered silicon-containing solids into gaseous silicon forms; subjecting to purification by minimal distillation; collecting the gaseous silicon forms as a condensed liquid of silicon-containing compounds; and utilizing the silicon-containing compounds for silicon deposition.

Abstract: The present invention is for the recovery of maximum silicon value of kerf silicon waste, produced during the manufacture of silicon wafers by wire saw, diamond saw and chemical mechanical polishing, as high purity metallurgical silicon. This recovery is achieved by a process scheme that effects an initial removal of minor extrinsic metallic impurities but not the major silicon compound impurities, and followed, preferentially, by a direct metallurgical process to form elemental silicon. The recovered silicon is for use as feedstock for polysilicon manufacturing, as high purity polysilicon for PV application, and in metallurgical alloy manufacture.

Abstract: A process for the recovery of silicon includes providing silicon-containing solids recovered from a silicon manufacturing process, said recovered silicon-containing solids being substantially free of semiconductor dopants; converting the recovered silicon-containing solids into gaseous silicon forms; subjecting to purification by minimal distillation; collecting the gaseous silicon forms as a condensed liquid of silicon-containing compounds; and utilizing the silicon-containing compounds for silicon deposition.

Abstract: A process for the recovery of silicon includes providing silicon-containing solids recovered from a silicon manufacturing process, said recovered silicon-containing solids being substantially free of semiconductor dopants; converting the recovered silicon-containing solids into gaseous silicon forms; subjecting to purification by minimal distillation; collecting the gaseous silicon forms as a condensed liquid of silicon-containing compounds; and utilizing the silicon-containing compounds for silicon deposition.

Abstract: A process for the recovery of silicon includes providing silicon-containing solids recovered from a silicon manufacturing process, said recovered silicon-containing solids being substantially free of semiconductor dopants; converting the recovered silicon-containing solids into gaseous silicon forms; subjecting to purification by minimal distillation; collecting the gaseous silicon forms as a condensed liquid of silicon-containing compounds; and utilizing the silicon-containing compounds for silicon deposition.

Abstract: This invention describes methods of compacting and densifying high purity silicon powder to defined geometric forms and shapes. High purity silicon powder is first mixed with binder from a select group of binders and pressed into desired shapes in a mechanical equipment. The binder is removed either in a separate step or combined with a subsequent sintering operation. The binders and process conditions are chosen to make negligible change to the purity of the silicon in the end product. When high purity silicon powder is utilized in the process, the end use for the densified silicon compacts is primarily as feedstock for silicon-based photovoltaic manufacturing industries.

Abstract: A discharge chamber for an arc discharge metal halide lamp having light permeable walls bounding a discharge region in which ionizable materials are provided with at least one electrode accommodation opening therein extending along a selected path between that discharge region and a region outside those walls. An electrode arrangement extends through the electrode accommodation opening having therein a thin electrical conductor positioned at least in part therein with a major surface that has surface curvature in at least some of those portions thereof positioned in said electrode accommodation opening to be in one of many alternative configurations. A sealing frit of mixed metal oxides is positioned about at least a portion of the thin electrical conductor within the electrode accommodation opening both at the major surface thereof and on an opposite side thereof.

Abstract: A discharge chamber for an arc discharge metal halide lamp having light permeable walls bounding a discharge region in which ionizable materials are provided with at least one electrode accommodation opening therein extending along a selected path between that discharge region and a region outside those walls. An electrode arrangement extends through the electrode accommodation opening having therein a thin electrical conductor positioned at least in part therein with a major surface that has surface curvature in at least some of those portions thereof positioned in said electrode accommodation opening to be in one of many alternative configurations. A sealing frit of mixed metal oxides is positioned about at least a portion of the thin electrical conductor within the electrode accommodation opening both at the major surface thereof and on an opposite side thereof.

Abstract: A high pressure discharge lamp formed of a polycrystalline alumina ceramic arc tube which includes a discharge zone and end tubes on each side to seal the tube, the discharge zone containing light emitting metal halides and mercury and a starting gas of argon or xenon. The end tubes have longitudinally extending openings therein. The end tubes have proximal ends adjacent the arc tube and distal ends furthermost removed from the arc tube. An electrical feed through is disposed in each of the end tubes which includes a thin metal foil section disposed between two electrically conductive lead in wire wires. One of the lead in wire wires has an electrode disposed thereon. A sealing compound seals the electrical feed through to the alumina of the end tubes at the outer ends thereof.

Abstract: An electrodeless fluorescent lamp comprises a closed-loop (“tokamak”) envelope, two ferrite cores, and an induction coil that is disposed on the envelope walls inside the closed-loop formed by the envelope. The envelope comprises two straight tubes of the same diameter. All coils' turns have essential the same length and are parallel to each other and to the closed-loop axis. Each ferrite core encircles a segment of each the coil's turn and one connecting tube. The lamp can be operated at driving frequencies of 100-600 kHz and lamp powers of 50-250 W. The ferrite core power losses were 6-8 W when the lamp was operated at a frequency of 200-300 kHz and lamp power of 140-150 W. The lamp light output was 12,500 lumen and luminous efficacy was 87 LPW.

Abstract: An electrodeless fluorescent lamp comprises a closed-loop (“tokamak”) envelope, two ferrite cores, and an induction coil that is disposed on the envelope walls inside the closed-loop formed by the envelope. The envelope comprises two straight tubes of the same diameter. All coils' turns have essential the same length and are parallel to each other and to the closed-loop axis. Each ferrite core encircles a segment of each the coil's turn and one connecting tube. The lamp can be operated at driving frequencies of 100-600 kHz and lamp powers of 50-250 W. The ferrite core power losses were 6-8 W when the lamp was operated at a frequency of 200-300 kHz and lamp power of 140-150 W. The lamp light output was 12,500 lumen and luminous efficacy was 87 LPW.

Abstract: A high pressure discharge lamp formed of a polycrystalline alumina ceramic arc tube which includes a discharge zone and end tubes on each side to seal the tube, the discharge zone containing light emitting metal halides and mercury and a starting gas of argon or xenon. The end tubes have longitudinally extending openings therein. The end tubes have proximal ends adjacent the arc tube and distal ends furthermost removed from the arc tube. An electrical feed through is disposed in each of the end tubes which includes a thin metal foil section disposed between two electrically conductive lead in wire wires. One of the lead in wire wires has an electrode disposed thereon. A sealing compound seals the electrical feed through to the alumina of the end tubes at the outer ends thereof.

Abstract: A fluorescent lamp having an adjustable color temperature comprising at least two elongated fluorescent discharge tubes (10 & 20), one tube (10) having a larger diameter than the other (20). The tubes (10 & 20) are assembled into a single unit. A groove (12) is disposed within the larger tube (10) and runs parallel to the longitudinal axis. The smaller diameter tube (20) is snugly nested within the groove (12) and in intimate contact with the larger diameter tube (10). The larger diameter tube has a phosphor coating producing one color temperature and the smaller diameter tube produces a different color temperature. Preferably, the larger tube has a phosphor coating that emits a low color temperature of 3000.degree. K. or below and the smaller tube's phosphor coating emits a high color temperature of greater than 10,000.degree. K. A controller divides the power to the two tubes such that a variable color temperature is produced at nearly constant total power.

Abstract: An electrodeless fluorescent lamp and fixture is disclosed which operates at radio frequencies and contains a bifilar coil to reduce RF voltage between the plasma and the coil and a metallic cylinder (10) to remove heat from a said bifilar coil. The bifilar coil consists of two windings. The primary (induction) winding (6) is used to generate RF electrical azimuthal field in the bulb volume needed to maintain the inductively-coupled RF plasma. The second (bifilar) winding (18) has essentially the same number of turns and is wound on the inductive winding (6), but in the direction opposite to that of the primary (inductive) winding. The RF current flowing in the inductive winding (6) induces an RF voltage of the opposite polarity in the bifilar winding (18), so two adjacent turns of both windings have equal (or nearly equal) but of opposite sign RF potentials with respect to the plasma.