Effective lifetimes exceeding 300 μs in gettered p-type epitaxial kerfless silicon for photovoltaics

• Main Authors: Powell, D. M. (Contributor), Hao, R. (Author), Ravi, T. S. (Author), Hofstetter, Jasmin (Contributor), Fenning, David P. (Contributor), Buonassisi, Tonio (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Mechanical Engineering (Contributor), Massachusetts Institute of Technology. Research Laboratory of Electronics (Contributor)
• Format: Article
• Language: English
• Published: American Institute of Physics (AIP), 2015-06-08T18:58:01Z.
• Subjects: Article
• Online Access: Get fulltext

We evaluate defect concentrations and investigate the lifetime potential of p-type single-crystal kerfless silicon produced via epitaxy for photovoltaics. In gettered material, low interstitial iron concentrations (as low as (3.2 ± 2.2) × 10[superscript 9] cm[superscript −3]) suggest that minority-carrier lifetime is not limited by dissolved iron. An increase in gettered lifetime from <20 to >300 μs is observed after increasing growth cleanliness. This improvement coincides with reductions in the concentration of Mo, V, Nb, and Cr impurities, but negligible change in the low area-fraction (<5%) of dislocated regions. Device simulations indicate that the high bulk lifetime of this material could support solar cell efficiencies >23%.
United States. Dept. of Energy (Contract DE-EE0005314)
National Science Foundation (U.S.) (United States. Dept. of Energy NSF CA EEC-1041895)
American Society for Engineering Education. National Defense Science and Engineering Graduate Fellowship
Alexander von Humboldt-Stiftung (Feodor Lynen Postdoctoral Fellowship)