The J-V curve of a solar cell under one sun illumination (AM 1.5G, 100 mW/cm^2) can be used to evaluate the power conversion efficiency (PCE). The measurement is to apply the voltage while measuring the current with a load resistor. Voc and Jsc represent the open-circuit voltage and short-circuit current density, respectively. The lower series resistance (Rs) and higher shunt resistance (Rsh) results in the higher fill factor (FF). The PCE can be obtained when the Voc, Jsc and FF are obtained from the J-V curve.