Efficiency of silicon solar cells containing chromium

Patent · 01 January 1982

OSTI ID:864107

Salama, Amal M ^[1]

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1. New Port Beach, CA

Efficiency of silicon solar cells containing about 10.sup.15 atoms/cm.sup.3 of chromium is improved about 26% by thermal annealing of the silicon wafer at a temperature of 200.degree. C. to form chromium precipitates having a diameter of less than 1 Angstrom. Further improvement in efficiency is achieved by scribing laser lines onto the back surface of the wafer at a spacing of at least 0.5 mm and at a depth of less than 13 micrometers to preferentially precipitate chromium near the back surface and away from the junction region of the device. This provides an economical way to improve the deleterious effects of chromium, one of the impurities present in metallurgical grade silicon material.

• Research Organization: California Institute of Technology
• Assignee: Frosch, Robert A. Administrator of National Aeronautics and Space (New Port Beach, CA);Salama, Amal M. (New Port Beach, CA)
• Patent Number(s): US 4311870
• OSTI ID: 864107
• Country of Publication: United States
• Language: English

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