Toward High-Performance Polymer Photovoltaic Devices for Low-Power Indoor Applications

This article describes the performance of organic photovoltaic (OPV) devices, incorporating three different polymer/fullerene derivative blends, under low-level lighting conditions. The devices exhibit much higher power conversion efficiencies (PCEs) under indoor lighting conditions than they do under sunlight. The best-performing device is capable of delivering a power output of 22.57 μW cm⁻², corresponding to a PCE of 13.76%, under illumination with indoor lighting conditions at 500 lux. Increasing the open-circuit voltage (V_oc) of the OPV devices is the most critical factor for achieving high device performance for low-power indoor applications. Therefore, the device power output will be maximized if we could obtain a larger energy difference between the highest occupied molecular orbital of the polymer donor and the lowest unoccupied molecular orbital of the electron acceptor, thereby ensuring a high value of V_oc.