In the presence of both series and shunt resistances, the IV curve of the solar cell is given by;
and the circuit diagram of the solar cell is given as;
Parasitic series and shunt resistances in a solar cell circuit.
To combine the effect of both series and shunt resistances, the expression for FFsh, derived above, can be used, with FF0 replaced by FFs [1]. The overall equation then becomes;
where FFs is given by;
and by combining the above equations, the net equation for FF becomes;
Ideal Cell: Voc = 0.623 Isc = 35 mA/cm2 FF = 0.83
Real Cell: Voc = 0.612 Isc = 34.6 mA/cm2 FF = 0.67
The following calculator determines the effect of Rs and Rsh on the cell fill factor using the same variable definitions as above.
- 1. , Solar Cells - Operating Principles, Technology and System Application. Kensington, Australia: University of NSW, 1992.