Characterization and modeling of back-contact back-junction silicon solar cells

The presented paper develops a model to simulate the J-V characteristic of an industrially structurized back-contact back-junction silicon solar cell to determine the influences of the main loss mechanisms on the cell parameters. In particular, the model contains an analysis to determine the detrimental effect of the electrical shading losses on the short circuit current density. The theoretical calculations show a good agreement with the measurement results of back-contact back-junction solar cells fabricated at Fraunhofer ISE. Furthermore the developed model was used to perform optimizations of the cell geometry. The modeling results show that the optimum base resistivity, base width and pitch is a balance between series resistance losses and electrical shading losses.