Brändler, LisaLisaBrändlerNiklaus, LukasLukasNiklausSchott, MarcoMarcoSchottLöbmann, PeerPeerLöbmann2023-04-122023-04-122023https://publica.fraunhofer.de/handle/publica/43965810.1002/admt.202201903UV irradiation is used to precharge sputtered tungsten trioxide (WO3) on polyethylene terephthalate enhancing the photochromic response with organic solvents. A comparison between the optical and electrochemical properties of photochemically and electrochemically charged WO3 results in a correlation of the transmittance to the respective charge density. This allows for a precise control of the charge density in the precharging process monitored by UV-Vis spectroscopy. A proof-of-concept flexible electrochromic device combining precharged WO3 (charge density: 20 mC cm-2) and Prussian blue (15 mC cm-2) exhibits a superior change in the visible light transmittance (τv) from 8% (dark) to 79% (bleached) and a coloration efficiency of 139 cm2 C-1 at 716 nm.enelectrochromic devicesphotochromismprechargingPrussian bluetungsten trioxideDDC::500 Naturwissenschaften und Mathematik::530 PhysikDDC::500 Naturwissenschaften und Mathematik::540 ChemieDDC::500 Naturwissenschaften und Mathematik::500 Naturwissenschaftenjournal article