A method for the direct measurement of solar cell shunt resistance

A method is described for the direct measurement of the shunt resistance of a solar cell, in which a prior knowledge of the value of the other lumped circuit parameters is not required. The shunt resistance is determined from measurements of open-circuit voltage and short-circuit current at very low illumination conditions under which a linear relationship exists such that
V_{oc} = R_{sh} I_{sc}
. The shunt resistances of three different commercial cells ranging between 65 and 1170 Ω were measured successfully. The constraints of the method are also discussed.