A new concept of charging supercapacitors based on the photovoltaic effect†
Abstract
A significant enhancement in the areal capacitance of a Co(OH)2 supercapacitor charged and discharged under light illumination is clearly observed, with the capacitance about two-fold higher than that operated under dark conditions. This is because Co(OH)2 has an energy band gap of 2.85 eV and can absorb blue light and generate photoelectrons via the photovoltaic effect, leading to high current density.