Stress induced inhomogeneities in crystalline silicon solar cells

In this contribution we present a fully scalable, quasi-SPICE distributed modelling approach for a wholesome analysis of stress induced, as well as inherent inhomogeneities (material impurities, grain boundaries) in silicon solar cells and PV modules based on electroluminescence imaging. We describe the derivation of electrical models for different IEC TS 60904-13 recognised stress induced inhomogeneities, namely the active and the inactive cracks, dead cell areas, and contact finger interruptions, and highlight their effects on the current-voltage characteristic of the cell. We validate our model on a selection of experimental cases of sample silicon solar cells on the basis of a comparative study of current-voltage characteristics and electroluminescence images. We demonstrate the applicability of our model on a complexly damaged full-sized sample cell, showing excellent agreement with the measurements