Germanium-enriched silicon material for making solar cells

US7887633B2 · kind B2 · utility

Assignee

• Calisolar, Inc. · US

Inventors

• Fritz Kirscht · Berlin, DE
• Vera Abrosimova · Berlin, DE
• Matthias Heuer · Berlin, DE
• Anis Jouini · Chambéry, FR
• Dieter Linke · Berlin, DE
• Martin Kaes · Berlin, DE
• Jean Patrice Rakotoniaina · Halle (Saale), DE
• Kamel Ounadjela · Belmont, US

Key dates

• Filing date: Jun 16, 2008
• Grant date: Feb 15, 2011
• Expiry date: Oct 26, 2028

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T117/1068
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

Techniques for the formation of silicon ingots and crystals using silicon feedstock of various grades are described. Common feature is adding a predetermined amount of germanium to the melt and performing a crystallization to incorporate germanium into the silicon lattice of respective crystalline silicon materials. Such incorporated germanium results in improvements of respective silicon material characteristics, mainly increased material strength. This leads to positive effects at applying such materials in solar cell manufacturing and at making modules from those solar cells. A silicon material with a germanium concentration in the range (50-200) ppmw demonstrates an increased material strength, where best practical ranges depend on the material quality generated.