Series resistance is determined by contacts and bulk resistances
whereas shunt resistance by defects and traps in a solar cell.
From a graphical representation of IeV curves shown in Fig. 2,
a series resistance (RS) is a slope of the dark IeV curve in the first quadrant,
a shunt resistance (Rsh) is a slope at near-zero voltage,
the internal dynamic resistance (Rd) is a slope at of the IeV curve
(dark and illumination) at an operating point. In addition,
the external dynamic resistance is the ratio of the voltage and current at
terminals of a solar cell, and, therefore, is equal to series resistance
in series with the internal dynamic resistance [12].