High-performance electrochromic WO3 film driven by controllable crystalline structure and its all-solid-state device

In this paper, a WO3 film was prepared with a controllable crystalline structure by adjusting the power in a magnetron sputtering deposition process. This allowed the WO3 film combine the advantages of excellent cyclic stability imparted by highly ordered structure WO3, and fast response and satisfactory coloration efficiency imparted by highly disordered structure WO3. The adjusted WO3 sputtered film displayed superior electrochromic properties comprising high transmittance modulation (74.4% at 550 nm), large coloration efficiency (41.5 cm2·C-1), fast switching speed in addition to excellent cycle stability (93.5% transmittance modulation retention over 1000 cycles). More importantly, an all-solid-state electrochromic device (ECD) founded on this WO3 film exhibited excellent electrochromic performance due to enhanced electrochromic properties of WO3 layer. This work demonstrates a novel way for improving the performances of electrochromic (EC) films and devices.