Siemens Aktiengesellschaft

Siemens Solar Gmbh

Siemens Solar Industries International

Friedrich-Wilhelm Schulze

Hubert Aulich

Karl-Heinz Eisenrith

Adolf Muenzer

Reinhart Schade

Hans-Peter Urbach

Gerhard Lehner

Benedikt Strake

Robert Wieting

A solar cell has electrical conductors applied on a pattern of electric contacts on a front surface and extending transversely relative thereto with a portion projecting beyond the edge of the solar cell. The formation of the electrical pattern includes at least two elongated portions interconnected by a return portion which extends beyond the one edge. This return portion provides a stiffening suitable for reliable interconnection to an additional solar cell to achieve a connection of two conductors in the projecting region.

Solar cell with a connecting structure

An inside lining for the reaction chamber of an electric low shaft furnace, particularly for producing high-purity silicon from silicon oxide by carbothermic reduction, is provided which has a melting crucible of dense graphite and a thermal insulation, whereby at least the floor of the reaction chamber has an inside lining of high-purity carbon. The inside lining is constructed from graphite, graphite grits or lampblack. The inside lining provides good thermal insulation and does not further contaminate the molten metal due to furnace materials. The inside lining prevents a loss of material in that seepage of molten metal into the insulation is prevented by a rapid dropoff of the temperature in the insulation below the melting point of the metal.

High-purity lining for an electric low shaft furnace

In a method for separating solid reaction products from silicon produced in an arc furnace, molten silicon produced in the arc furnace in a reduction of SiO.sub.2 and carbon is filtered through a heated layer composed of SiC/Si after a so-called holding phase at a temperature in a region above a melting point of the silicon. The layer is preferably fashioned as a bottom plate of a crucible. The melt has eliminated from it SiO.sub.2 and SiC particles contained therein. The method serves for the production of silicon for solar cells. Due to the separation of SiO.sub.2 and SiC out of the molten silicon, an efficiency of above 10% is achieved in the solar cells fabricated from this material.

Method for separating solid reaction products from silicon produced in

Highly purified starting materials for the production of silicon suitable for fabrication of solar cells are produced via the carbo-thermal reduction process. A carbon-containing material with impurities therein, either by itself or admixed with glass bodies, which are attained from a melt of quartz sand and glass-forming additives formed into a fiber form and pulverized, is converted into a granulate form with the aid of a bonding agent. The resultant granulates are contacted with a hot inorganic acid, such as 3N HCl at about 90.degree. C., to extract substantially all impurities from the granulates, which can be in pellet or tablet form. The resultant purified pellets are then directly charged into an electrical arc furnace to yield solar-quality silicon. With this process, highly purified SiO.sub.2 and highly purified carbon are produced in a simple and cheap manner. The impurity level for boron, phosphorus and transition metal in these starting materials is less than about 10 ppm.

Method for producing high purity Si for solar cells

Growing community of inventors

Eching, Germany

Friedrich-Wilhelm Schulze