On the Performance Limiting Behavior of Defect Clusters in Commercial Silicon Solar Cells

We report the observation of defect clusters in high-quality, commercial silicon solar cell substrates. The nature of the defect clusters, their mechanism of formation, and precipitation of metallic impurites at the defect clusters are discussed. This defect configuration influences the device performance in a unique way -- by primarily degrading the voltage-related parameters. Network modelingis used to show that, in an N/P junction device, these regions act as shunts that dissipate power generated within the cell.