| Title: | 
        
            | Efficiency potential of solar cells based on compensated multicrystalline silicon material | 
        
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            | Published by: | Publication date: | 
        
            | ECN
                Solar Energy | 6-9-2010 | 
        
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            | ECN report number: | Document type: | 
        
            | ECN-M--10-014 | Conference Paper | 
        
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            | Number of pages: | Full text: | 
        
            | 5 | Download PDF | 
    
    
        Presented at: 25th European Photovoltaic Solar Energy Conference and Exhibition - 5th World Conference on Photovoltaic Energy Conversion, Valencia, Spain, 6-10 september 2010.
        
        
    
    
        Abstract:
        The purpose of the present work is evaluation of the impact of Cr-contamination on solar cell properties of compensated multicrystalline silicon (mc-Si) ingots. Cr is an effective recombination centre of practical relevance. Studying its effects in compensated material allows monitoring the dependence of solar cell characteristics on resistivity. Therefore, two compensated materials were investigated: with and without addition of 20 ppm wt Cr to the high-purity Si feedstock. Lifetime measurements on as-cut wafers showed more than one order of magnitude decrease in case of Cr-containing samples. Solar cell manufacturing was accomplished for p-type wafers utilizing two different emitter sheet resistances and a conventional industrial screen-print process. It was found that gettering and hydrogenation involved in cell processing significantly improved material properties in the presence of Cr. As a result cell performance was comparable to the compensated reference. Efficiencies of p-type cells in the range of 15.7% were achieved for this heavily Cr-contaminated, compensated mc-silicon of a resistivity of 4 Ohm.cm.
    
    
        
        
    
    
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