Thin silicon String Ribbon for high efficiency polycrystalline solar cells

Author

Wallace, R.L. ; Hanoka, J.I. ; Narasimha, S. ; Kamra, S. ; Rohatgi, A.

Author_Institution

Evergreen Solar Inc., Waltham, MA, USA

fYear

1997

fDate

29 Sep-3 Oct 1997

Firstpage

99

Lastpage

102

Abstract

Silicon ribbon of 100 μm thickness has been grown using the String Ribbon crystal growth method. Flat, low stress material has been grown using both a tunable active afterheater and a simplified passive afterheater. The material is polycrystalline, with grain size as large as 2 cm across. Research sized cells (1 cm²) of over 15% efficiency have been made on this material. Effects of forming gas anneal, Al back contact thickness and BSF, and PECVD SiN/MgF₂ vs. ZnS/MgF₂ were studied as a function of efficiency. The internal quantum efficiency (IQE) of the cells shows an unusually high sensitivity to light bias. Further optimization is expected to lead to 16% cells in the near future

Keywords

annealing; crystal growth from melt; elemental semiconductors; plasma CVD coatings; semiconductor growth; silicon; solar cells; 100 mum; 15 percent; 2 cm; Al; Al back contact thickness; PECVD SiN/MgF₂; PECVD ZnS/MgF₂; Si; Si solar cells; SiN-MgF₂; String Ribbon crystal growth method; ZnS-MgF₂; forming gas anneal; grain size; high efficiency polycrystalline solar cells; internal quantum efficiency; light bias sensitivity; passive afterheater; thin silicon String Ribbon; tunable active afterheater; Annealing; Artificial intelligence; Coatings; Crystalline materials; Grain size; Photovoltaic cells; Production; Robustness; Silicon compounds; Thermal stresses;

fLanguage

English

Publisher

ieee

Conference_Titel

Photovoltaic Specialists Conference, 1997., Conference Record of the Twenty-Sixth IEEE

Conference_Location

Anaheim, CA

ISSN

0160-8371

Print_ISBN

0-7803-3767-0

Type

conf

DOI

10.1109/PVSC.1997.653934

Filename

653934