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Low gap Amorphous (Si,Ge) Solar Cells

Published online by Cambridge University Press:  17 March 2011

Vikram L. Dalal
Affiliation:
Iowa State University, Dept. of Electrical and Computer Engineering, Ames, Iowa 50011
Zhiyang Zhou
Affiliation:
Iowa State University, Dept. of Electrical and Computer Engineering, Ames, Iowa 50011
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Abstract

We report on the growth and fabrication of low-gap a-(Si,Ge) solar cells, including cells made from a-Ge:H. The cells were deposited from silane and germane, or germane alone, using a high dilution of hydrogen in a remote ECR plasma reactor. We have been able to achieve a Tauc gap of as low as 1.15 eV with good device properties. The fill factors were in the 50%-60% range, and the Urbach energies measured in devices were in the range of 45 meV. The devices were of the p/i/n type with light entering the p layer. The devices were fabricated on stainless steel substrates. We also report on experiments to improve graded gap solar cells in a- (Si,Ge) using a novel combination of ppm-boron dopant and bandgap grading. It is shown that this grading significantly improves the device performance, both voltage and fill factor.

Type
Research Article
Copyright
Copyright © Materials Research Society 1999

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References

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