Title :
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
fDate :
29 Sep-3 Oct 1997
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;
Conference_Titel :
Photovoltaic Specialists Conference, 1997., Conference Record of the Twenty-Sixth IEEE
Conference_Location :
Anaheim, CA
Print_ISBN :
0-7803-3767-0
DOI :
10.1109/PVSC.1997.653934
