| Title: | 
        
            | N-type solar grade silicon for efficient p+n solar cells: overview and main results of the EC NESSI project | 
        
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            | Author(s): | 
        
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                Geerligs, L.J.; Tool, C.J.J. ; Kinderman, R. ; Röver, I. ; Wambach, K. ; Kopecek, R. ; Buck, T. ; Libal, J. ; Petres, R. ; Fath, P. ; Sánchez-Friera, P. ; Alonso, J. ; Acciarri, M. ; Binetti, S. ; Pizzini, S. | 
        
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            | Published by: | Publication date: | 
        
            | ECN
                Solar Energy | 11-9-2006 | 
        
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            | ECN report number: | Document type: | 
        
            | ECN-RX--06-021 | Conference Paper | 
        
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            | Number of pages: | Full text: | 
        
            | 4 | Download PDF | 
    
    
        Presented at: 21st European Photovoltaic Solar Energy Conference and Exhibition, Dresden, Germany, 4-8 september 2006.
        
        
    
    
        Abstract:
        An integrated R&D effort was performed, aimed at the industrial use of highly n-doped waste silicon, and at processing of this silicon to n-doped ingots, solar cells, and modules. An evaporation process was successfully applied to reduce the phosphorous concentration in the waste Si. Additional experimental n-type ingots were produced by blending (highly doped with undoped) silicon. Industrial p+nn+ cell processes were developed with a front boron emitter and, alternatively, a rear aluminium emitter. A high and homogeneous carrier lifetime was observed in the n-type mc-Si which makes the material suitable even for a rear emitter process. Solar cell efficiencies of 14.7% (front emitter) and 14.4% (rear emitter) were obtained on mc-Si; while more than 16% efficiency was demonstrated on monocrystalline wafers. Cell interconnection by conductive adhesive was developed and performs well.
    
    
        
        
    
    
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