A fast-switching light-writable and electric-erasable negative photoelectrochromic cell based on Prussian blue films

► A photoelectrochromic cell was fabricated. ► The cell is composed of dye-sensitized TiO2 and Prussian blue electrodes. ► The cell can be bleached under illumination and re-colored by an external voltage. ► Adjustable grayscales and fast response are obtained.