Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.v.

Universitat Konstanz

Elkem Solar as

Eisenmann Anlagenbau Gmbh & Co Kg

Rec Solar Norway as

Bernd Raabe

Ragnar Tronstad

Erik Enebakk

Giso Hahn

Eric Enebakk

Kristian Peter

Helge Haverkamp

Amir Dastgheib-Shirazi

Felix Book

Werner Mai

Marco Ebbinghaus

Hans Kaspar Von Kaphengst

The present invention relates to multicrystalline p-type silicon wafers with high lifetime. The silicon wafers contain 0.2-2.8 ppma boron and 0.06-2.8 ppma phosphorous and/or arsenic and have been subjected to phosphorous diffusion and phosphorous gettering at a temperature of above 925&#xb0; C. The invention further relates to a method for production of such multicrystalline silicon wafers and to solar cells comprising such silicon wafers.

Solar cells

A method is presented for producing a silicon solar cell with a back-etched emitter preferably with a selective emitter and a corresponding solar cell. According to one aspect, the method comprises the following method steps: producing a two-dimensionally extending emitter at an emitter surface of a solar cell substrate; applying an etching barrier onto first partial zones of the emitter surface; etching the emitter surface in second partial zones of the emitter surface not covered by the etching barrier; removing the etching barrier; and producing metal contacts at the first partial zones. During the method, especially during the etching of the emitter surface in the second partial zones, a porous silicon layer is advantageously produced, which is then oxidized. This oxidized porous silicon layer can subsequently be etched away together with any phosphorus glass that may be present. The method makes use of conventional screen-printing and etching technologies and is thus compatible with current industrial production plants.

Method for producing a silicon solar cell with a back-etched emitter as well as a corresponding solar cell

Growing community of inventors

Constance, Germany

Bernd Raabe