High‐Rate Deposition of Electrochromic Organotungsten Oxide Thin Films for Flexible Electrochromic Devices by Atmospheric Pressure Plasma Jet: The Effect of Substrate Distance

High‐rate deposition of electrochromic organotungsten oxide (WO x C y ) films onto flexible PET (polyethylene terephthalate)/ITO (indium tin oxide) substrates by a tmospheric p ressure‐ p lasma e nhanced c hemical v apor d eposition (AP‐PECVD) with a tmospheric p ressure p lasma j et (APPJ) under various substrate distances is investigated. A precursor (tungsten carbonyl, W(CO) 6 , TC) vapor, carried by argon gas, is injected into air plasma torch for the synthesis of WO x C y films. Uniform light modulation up to 1 cm wide on PET/ITO/WO x C y is produced, while the moving PET/ITO substrate is exposed to a 0.3 cm diameter plasma torch at room temperature (≈23 °C) and atmospheric pressure. The porous APPJ‐synthesized WO x C y films result in fast responses using potential steps for coloration of 11.5 s at −1V and bleaching of 7.2 s at +1V, respectively. APPJ‐synthesized WO x C y films offer noteworthy electrochromic performance in light modulation with up to 73.0% of transmittance variation, optical density change of 0.72 and coloration efficiency of 67.7 cm 2 · C −1 at a wavelength of 800 nm. magnified image