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US 4,247,528 AGranted
Method for producing solar-cell-grade silicon
AssigneeDow Corning Corporation
InventorsVishu D. Dosaj, Lee P. Hunt
Life of this patent
Estimating the term…
Abstract
Silica is reduced in a direct arc reactor by activated carbon or carbon black having relatively low boron (B) and phosphorus (P) contents to produce silicon having similarly low B and P contents and suitable for use in photovoltaic cells for converting solar energy directly to electrical energy.
Claims7
In a method for producing silicon wherein silica is reduced in a high temperature furnace by a carbonaceous reducing agent mixed with the silica, the improvements comprising:
- employing silica having a boron content of no greater than 10 parts per million by weight and a phosphorous content no greater than 20 parts per million by weight,
- employing a carbonaceous reducing agent selected from the group consisting of activated carbon and carbon black and having a boron content no greater than 10 parts per million by weight and a phosphorous content no greater than 10 parts per million by weight, and
- the carbonaceous reducing element being in the form of pellets whereby a solar grade of silicon is produced.
Dependencies are inferred from the claim text.