Influence of wafer quality on cell performance

This presentation will show how an improved understanding of multicrystalline wafer quality can explain the variations in cell performance across multicrystalline silicon blocks. Using infrared scanning a silicon block was sorted out with precipitates in the middle of the block. Photoluminescence combined with defect etching revealed needle-like precipitates along the grain boundaries. The precipitations lead to reduced shunt resistance. In the middle of the block numerous crystallographic defects were identified that lower the current collection and the final cell efficiency.