COPPER PRECIPITATION EFFECTS IN SILICON USED IN SOLAR-CELLS

Microstructural evaluation tests (e.g. TEM, SEM) were performed on copper-doped p-type silicon single-crystal wafers before and after the solar cell fabrication. The copper concentration was 1015-1016 atoms/cm3. It was found that β-CuSi precipitates were formed during the growth process. No precipitates or other electrically active defects were detected in the solar cell junction depletion region. However, the copper precipitation in the bulk diminished the possibility of electrically active interstitial copper occurring in the lattice. These results explain the good electrical characteristics of the silicon solar cells under investigation. © 1979, The Electrochemical Society, Inc. All rights reserved.