Electrochromic properties of bismuth oxide thin films prepared by reactive pulsed laser deposition

The electrochromic behaviors of the tetragonal Bi2O3 films deposited by pulsed laser deposition at 300 degrees C were investigated by potential step and cyclic voltammetry coupled with an in situ charge-coupled device (CCD) spectrophotometer. The time-resolved absorption spectrum determined by potential step method indicated that the coloration time for Bi2O3 film was estimated to be 30 s. In addition, the electrochromic properties determined by cyclic voltammetry showed that this film could exhibit a significantly reversible variation between transparent and dark brown more than 50 times on switching between 3.5 and 0.7 V. The color efficiency at 630 nm was estimated to be 15 cm(2).C-1.