A crack analysis model for silicon based solar cells

Cracks in silicon layers of PV cells are a major problem for the photovoltaic industry and have an impact on the reliability of the PV technology. Especially considering the desire of developing and producing thinner and larger modules, which makes the cells more vulnerable to cracking. In this work an analysis of the performance of a PV module under different load types has been done. The numerical evaluation of the stress fields is done using the finite element method. Critical regions containing micro cracks in silicon have been modelled using a special meshing technique. Finally, to answer the question if induced stresses on cracked cells lead to a complete separation of cell parts, the theory of linear elastic fracture mechanics is applied and the resulting stress intensity factors (SIF's) under different load conditions are calculated.