Molecular coating unites photovoltaics, photodetection in one device

A research team from Korea University and Dongguk University has developed a novel molecular coating for organic solar cells that enables a single device to function simultaneously as a solar cell and a photodetector. This innovation overcomes the traditional conflict between the two technologies: solar cells require rapid charge movement for power generation, while photodetectors need to suppress charge movement to detect faint light signals. The breakthrough was achieved by applying a self-assembled monolayer of a simple molecule—benzene and phosphonic acid (BPA)—onto a transparent electrode (indium tin oxide, ITO). This molecular layer optimizes energy alignment at the interface, allowing efficient charge extraction for power generation and noise suppression for light detection. The BPA-coated device demonstrated a high indoor efficiency of 28.6% under typical indoor lighting conditions (1,000 lux LED at 2700K) and retained 87% of its performance after 1,000 hours of exposure. It offers a nearly ninefold improvement