Effects of minority-carrier storage at the interface states on the fill factor of m.i.s. solar cells

Current-voltage characteristics obtained under dark and illuminated conditions have been examined for Al-p-Si MIS solar cells. The results obtained show that the voltage across the cells taken at the maximum-power point is typically 50 mV smaller when the cells are illuminated compared to the voltage at the same point in darkness. This is explained as an increase in the recombination current and as an increased concentration of minority carriers at the interface states of about 10 trillion/sq cm when going from dark to illuminated conditions. The result is that the fill factor obtained from the illuminated characteristic is about 9% smaller than if the fill factor is calculated from the dark characteristics.