電致變色元件（Electrochromic Device，ECD）是利用對電致變色材料施加偏壓，改變材料本身的氧化還原狀態，使其達到可重複循環的染色/褪色反應。其應用範圍廣泛，目前主要商品為節約能源的變色型節能窗（smart window）。 本實驗以五氧化二鉭（Ta2O5）作為電致變色層，用溶膠凝膠(sol-gel)法製作透明、高穿透率的五氧化二鉭液體，利用旋轉塗佈法（spin-coating）製成五氧化二鉭薄膜，可大幅降低電致變色元件的生產成本，初步完成的全固態電致變色元件可重複循環達60次以上，最大對比度可達20％，而染色/褪色的響應，可在數秒內達成。 We successfully sol-gel synthesize electrochromic tantalum pentoxide (Ta2O5) coatings on indium tin oxide glass (ITO) at room temperatures. Compare to other tantala-based materials reported in the literature, our device is all-solid-state, with higher extinction, low-cost and a longer life-time. Ta2O5 is transparent over a wide range of wavelength. The coloration and bleaching states can be reversibly obtained for more than 60 cycles with an applied voltage as low as 3V. The achieved extinction is estimated to be over 20%. The coloring/bleaching response time is found in several seconds.
