The effect of the front contact sheet resistance on solar cell performance

The transparent top contact layer of a solar cell is a distributed resistance that cannot be easily represented mathematically. We have used a finite element model to calculate the current distribution in this transparent layer. The calculation gives the voltage drop along the layer as well as the resulting reduction in the current generated in the active layer of the solar cell. IV curves generated by the model are used to investigate various methods of experimentally determining series resistance. It is found that the suns- V oc method is the most accurate. A fit of the finite element model to experimental IV data from an organic solar cell is used as an example of obtaining solar cell model parameters.