Optimization of electrochromic performance of WO_3−x films grown by RF sputtering on gallium-doped zinc oxide

The present paper investigates the sputtered tungsten oxide thin films on gallium-doped zinc oxide-coated glass substrates concerning electrochromic behavior since the most promising candidate of smart glass in the future. Concordantly, each of the deposition parameters, including sputter power, total pressure, and O₂/Ar + O₂ gas ratio in the plasma, were examined in terms of electrochromic applications to enable to use of these values to be brought to large scale in commercial applications. As a result of comprehensive and systematic optimization studies, the optical modulation values were reached from 63.1 % to 70.8 % and the time needed for coloration and bleaching was observed as 7 and 5 s with final deposition values as 45 W power, 10 mTorr pressure, and 25 % O₂ ratio. Additionally, whilst durability is still a problem in electrochromic coatings, reasonable durability cycling was achieved after 900 switching without encapsulation.