Quantitative local current-voltage analysis with different spatially-resolved camera based techniques of silicon solar cells with cracks

The ongoing trend to decrease the wafer thickness in the fabrication of silicon solar cells increases the number of possible cracks. Therefore, an in-depth understanding of the influence of cracks on solar cells is necessary. In this work, we investigate silicon solar cells with cracks by employing three camera-based spatially-resolved techniques and use the data to quantitatively calculate local-current voltage parameters. Cracks mainly influence the recombination current density of a silicon solar cell. This fact is clearly shown by drastically increased recombination in the space charge region. This recombination reduces parameters like fill factor, open circuit voltage and the cell efficiency. The comparison of the solar cell data before and after the formation of cracks shows a 0.2 % absolute efficiency loss in the global current-voltage parameters and up to 1 % absolute efficiency loss in the local current-voltage analysis at the crack positions.