FoXy Development of Solar-Grade Silicon Feedstock ... - ISC Konstanz

M. Di Sabatino, E. J. Øvrelid, R. Kopecek, S. Binetti, V.D. Mihailetchi, L.Geerligs, A. N. WærnesFigure 7: Internal quantum efficiency of the n-type solar cellsmeasured for different passivation methods for boron emitter.Table 2 summarizes the best efficiencies of selected solar cellsproduced within the FoXy project. Note that no solar cellswere manufactured from ingots FS1 and F3 (Table 1).REFERENCES[1] E. J. Øvrelid, A. N. Wærnes, S. Santen, O. Raaness, E.Olsen, L.J. Geerligs, Proceedings of Silicon for the chemicalindustry, Trondheim, Norway, (July, 2006) 223-234.[2] H. Nordmark, M. Di Sabatino, M. Acciarri, J. Libal, S.Binetti, E.J. Øvrelid, J.C. Walmsley, R. Holmestad,Proceeding of 34 th IEEE conference (San Diego, USA, May2008).[3] S. Binetti, J. Libal, M. Acciarri, M. Di Sabatino, H.Nordmark, E.J. Øvrelid, J.C. Walmsley, R. Holmestad,Material Science and Engineering B, in press (2009).[4] J. Libal, S. Novaglia, M. Acciarri, S. Binetti, R. Petres, J.Aramughan, R. Kopecek, A. Prokopenko, J. Appl Physics,104 (2008).[5] V.D. Mihailetchi, Y. Komatsu, L.J. Geerligs, Appl. Phys.Letters, 92 (2008).Table 2. Best solar cell efficiencies achieved within the FoXyproject.Ingot Crys. Type Size Best Eff. Ref.[mm 2 ] [%]FP1 p 156x156 16.5 ISCFP2 p (ref) 156x156 16.8 ISCFP6 Cz n 125x125 17.5 ECNFP7n (ref) 125x125 17.7 ECNFS9 p 125x125 15.8 ISCFS10 mc p 125x125 15.6 ISCFS11 p (ref) 125x125 15.7 ISCF1 p 156x156 15.0 ISCF2 mc p 156x156 14.5 ISCNote that the efficiency difference of about 1% absolutebetween p- and n-type Cz-Si cells is also due to anadvanced cell structure for n-type cells which wasdeveloped within the project leading to recordefficiencies for screen printed structures of 18.3% on n-type Cz-Si substrates [5].CONCLUSIONSThis work summarizes some of the major results achieved inthe European project FoXy.1. The results presented show that solar cells withgood efficiencies can be made with SoG silicon andblended feedstock. These achievements will securehigh volume production of SoG-Si for the PVindustry.2. Good efficiency solar cells can also be made fromrecycled off-cut materials with significant costreduction.3. It has been shown that wafers on a large-scaleindustrial production line 150x150mm 2 with > 16%cell efficiency with increased yield can bemanufactured.ACKNOWLEDGEMENTSThe authors thank the FoXy consortium and Mr. AndreasPiontek (EU officer) for interesting discussion. The work wasfinanced by the EU project FoXy (contract nr SES6-019811).4