A photoelectrophyscial capacitor with direct solar energy harvesting and storage capability

Solar energy harvesting and storage are important topics of renewable energy. Current solid-state photovoltaic cells and conventional photoelectrochemical cells cannot harvest and directly store the converted energy within one single structure. We report on a photocapacitor that can convert and store solar energy based on a bio-inspired mechanism. The photocapacitor converts the solar energy through photovoltaic effect, and stores the converted energy by maintaining the concentration difference across a membrane upon light irradiation. Results have shown that the device can be charged photovoltaically and hold the voltage of 0.47V with a capacity of 40.63 mC/cm² for more than 24 hours.