Spray coated ultrathin films from aqueous tungsten molybdenum oxide nanoparticle ink for high contrast electrochromic applications

Ultrathin tungsten molybdenum oxide nanoparticle films were fabricated from aqueous ink by a spray coating technique. With the in situ heating of the hot plate during the spray coating process, the detrimental effects of oxygen vacancies on electrochromic (EC) materials could be eliminated. The spray coated ultrathin films exhibit higher contrast than the drop casted films, which would provide a versatile and promising platform for energy-saving smart (ESS) windows, batteries, and other applications.