The effect of precursor aging on optical and electrochromic properties of WO3 thin films for making smart windows

This paper proposes a suitable method for increasing effective surface area of electrodeposited WO3 thin films. This is done because effective surface area improves optical and electrochromic properties in smart windows. Therefore، we investigated precursor aging atperoxytungstate precursor (0، 24، 48 and 72 h). Experiments showed by increasing aging time of the precursor solution، larger aggregates were formed. Their morphology، optical and cyclic voltammogram characterization showed that increasing aging time improves optical and electrochromic properties of WO3 thin films in 1M LiClO4-PC electrolyte. The WO3 films with aging time of 72 h exhibited a noticeable EC performance with variation of transmittance up to 72% at 633nm. The result indicated that using two electrochromic materials with complementary properties could improve the function of the device.