Generalization of the area method for the determination of the parameters of a non-ideal solar cell

The equation of the current-voltage characteristic of a non-ideal solar cell, with finite series and shunt resistances, was reduced to explicit form by means of a suitable rotation of coordinates. Thus the area under the characteristic curve could be calculated in analytical form for realistic models of the cell. Substituting in the new formula the area numerically computed from the experimentally measured curve, there appears the possibility of extending the so called area method to the determination of the quality factor and the series and shunt resistances of the cell