Back to results
US 7,922,989 B2Granted
Method for making silicon for solar cells and other applications
OwnerSteven C. Amendolainventor
Life of this patent
Estimating the term…
Abstract
A method for preparation of high purity silicon suitable for photovoltaic cells using reduction of silica, which is pre-purified in an aqueous solution, in presence of a reducing agent, preferably carbonaceous agent, where the pre-purified silica has a low amount of boron suitable for photovoltaic cells is described.
Claims24
A method of producing silicon having high purity suitable for photovoltaic cells, the method comprising
- (a) obtaining an aqueous alkali metal silicate solution from a silicon containing material;
- (b) filtering the aqueous alkali metal silicate solution to remove solid impurities, said solid impurities comprising a compound containing phosphorous;
- (c) treating the aqueous alkali metal silicate solution with a boron specific chelating resin, wherein the boron specific chelating resin is an ion exchange resin having a functional group of N-methylglucamine;
- (d) converting the aqueous alkali metal silicate solution to purified silica, wherein the purified silica has a low amount of boron and phosphorous suitable for photovoltaic cells;
- and
- (e) reducing the purified silica with a carbonaceous agent,
- wherein steps (b) and (c) are both performed in a basic condition.
4 more elements
Dependencies are inferred from the claim text.