The J–V equation of a solar cell is implicit and requires iterative calculation to determine the fill factor and the maximum power point. Here an explicit model for J–V characteristic is proposed which is applicable to a large variety of solar cell. This model allows an easy estimation of fill factor from four simple measurements of the bias points corresponding toVoc, Jsc, and any two voltage values lying between 0 and Voc, where Voc is the open circuit voltage and Jsc is the short circuit current density.
