1.3. Parameters of a solar cell
Double diode model is used to define the parameters of the solar cell. The double diode model has the limitations that it gives erroneous results when applied to high efficiency solar cells. In actual devices the recombination becomes a complex function of carrier concentration, resulting in ideality factor and the saturation current varying with voltage. Still, for the sake of simplicity we have used the double diode mode to define the parameters. The equivalent circuit of solar cell is shown in Fig. 1[6] and parameters of a solar cell are shown in Fig. 2[7].