Flexible electrochromic tungsten/titanium mixed oxide films synthesized onto flexible polyethylene terephthalate/indium tin oxide substrates via low temperature plasma polymerization

Abstract

An investigation has been taken on enhancing lithium electrochromic performances of mixed organotungsten oxide (WO_yC_z)/organotitanium oxide (TiO_yC_z) films, co-synthesized onto 60 Ω/square flexible polyethylene terephthalate (PET)/indium tin oxide (ITO) substrates by a low temperature plasma polymerization method at various mixed concentrations of precursors tungsten hexacarbonyl W(CO)₆ and titanium n-butoxide Ti(C₄H₉O)₄. The plasma polymerized-organo‑tungsten‑titanium oxides (WTi_xO_yC_z) films possess notable electrochromic performances while switch tested by a potential sweep from −1 V to 1 V at a scan rate of 50 mV/s and from 1 V to −1 V at a scan rate of −50 mV/s for 200 cycles of reversible Li⁺ ion intercalation and de-intercalation in a 1 M LiClO₄-PC electrolyte, still after bended 360^o around a 2.5 cm diameter rod for 1000 cycles. Optical modulation (ΔT) of 74.8% for WO_yC_z films at a wavelength of 850 nm is appreciably progressed of up to 82.7% for WTi_xO_yC_z films as co-deposited by a low temperature plasma polymerization method.