Simultaneous Measurement of Photocurrent and Recombination Emission in Organic Solar Cell

In this study, we measured the recombination emission from the CT state under different applied voltage in the OSC device and a photocurrent density flowing on the circuit simultaneously. By the experiment, we extracted only the information of CT state emission at the interface and proposed `PL-V plot` that is the voltage dependence of PL intensity of the CT state. The PL-V plot includes the information only from the radiative recombination at donor/acceptor interface, and is complementary to the `J-V plot` that is the most important information for evaluating OSCs. The result demonstrated that the fill factor of PL-V plot is definitely higher than that of J-V plot because the PL-V plot observes the CT state recombination only at the D/A interface, predicting the ideal FF of the device.