Electrochromic performance and potential stability of sputtered V2O5 film for a complementary inorganic all-solid-state electrochromic device

Vanadium Pentoxide (V₂O₅) has good ion storage capacity and weak anodic electrochromism. Since the V₂O₅ and Tungsten Trioxide (WO₃) films were used as the auxiliary and major color-changing layers, respectively, then they were combined with heat-cured gel (LiClO₄ + PC) + PMMA electrolyte as an complementary all-solid-state electrochromic device (ECD). Also, the V₂O₅ films were prepared at different oxygen flows and annealing temperatures. These results exhibited that oxygen flow of 4 sccm and annealing temperature of 400 °C can enable the optimal optical contrast (ΔT) to reach 38.7%@550 nm. The response time of the coloring(tc) and the bleaching(tb) were 5 and 4 s, respectively. Raman spectrum showed the stable phase of V⁵⁺ and specific element ratio of 2.52 and X-ray photoelectron spectroscopy (XPS) had the red shift phenomenon. However, the performance of ITO/V₂O₅/gel-electrolyte/WO₃/ITO device, the best working voltage was measured as ±2.5 V, the optical contrast was ΔT = 42% and the response time of tc and tb were 6.5 and 5.5 s, respectively. These results demonstrate that ECD has the advantages of fast response time and low voltage stable startup.