Suppressed Carrier Recombination and Boosted Open-Circuit Voltage of Indoor Organic Photovoltaic Device with Fullerene Acceptor

Indoor organic photovoltaic provides a promising energy for the off-grid self-power supply technology of the Internet of Things industry. In this work, the indoor organic photovoltaic devices were prepared with wide bandgap polymer PM6 as donor and fullerene derivatives PC 71 BM as acceptor. The photovoltaic performances, the carrier recombination characteristics, and the molecular packing of the PM6:PC 71 BM device were studied in detail as compared with the photovoltaic device with non-fullerene acceptor Y6. The matched spectral response range with indoor lighting source and rational energy level alignment of PC 71 BM suppresses carrier recombination under slim light illumination, improving the open-circuit voltage and fill factor of the prepared fullerene device, and an enhanced power conversion efficiency (PCE) of 18.7% is achieved under white LED illumination with intensity of 1000 Lux, while the PCE of the photovoltaic device with Y6 acceptor is only 14.7%. The superior photovoltaic performance of PM6:PC 71 BM organic photovoltaic device indicates that fullerene acceptors are effective materials choice for preparing high-performance organic photovoltaic devices under slim light illumination, and fullerene derivatives would play an important role in the preparation of high-efficiency indoor photovoltaic devices for Internet of Things utilization.