Statistical analysis of local shunts and their relationship with minority-carrier lifetime in multi-crystalline silicon solar cells

Local shunts in multi-crystalline Si solar cells were investigated statistically using minutely meshed mesa diodes fabricated on commercially available cells. The dark reverse current density Jdr in each mesa varied in a wide range of 10−9–1 A/cm2, which showed that local shunts over n+–p junction distributed spatially. The histogram of Jdr was analyzed to clarify cell performances, and a critical value of Jdr was proposed to classify the cell efficiency. Minority-carrier lifetime estimated using transient behavior of switching current was also discussed relating with the material quality.