Transition metal oxide films: Technology and “Smart Windows” electrochromic device performance

► We optimize electrochromic cell, working and counter electrodes, polymeric electrolyte. ► We study optical behavior of WO3-MoO3 and MoO3-Cr2O3, and their vibrational properties. ► Electrochromic properties WO3-MoO3 are excellent, MoO3-Cr2O3 film is optically passive. ► An electrochromic device was constructed with a polymeric electrolyte.