Improved coloration contrast and electrochromic efficiency of tungsten oxide films thanks to a surfactant-assisted ultrasonic spray pyrolysis process

Tungsten oxide films made by the surfactant-assisted ultrasonic spray pyrolysis show a high specific surface area, which results in one of the highest coloration contrast (83%) ever reported for tungsten oxide thin films. WO3 thin films also show excellent reversibility (94%), as well as good coloration efficiency (28 cm2/C).