LAUSR

Abstract In this paper, the Co doped TiO2 film with satisfactory electrochromic performances was prepared by a sol-gel method. To study the Co-doped influence on the TiO2 film for the electrochromic performances, we respectively regulated the Co ion content to 0, 0.4, 0.8 and 1.2 at%. Due to the Co ions doped into the TiO2 film, the synthesized film led to the generation of the oxygen vacancies. From the results, when the optimal Co ion content is 0.8 at%, the improved switching time (the bleached time of 2.9 s and the colored time of 5.1 s) and the improved coloration efficiency (18.89 cm2/C) compared to the other samples are obtained. These results can be due to the enhanced Li+ diffusion coefficient and electric conductivity, which result in the increase of the electrochromic reaction activity and the reduction of the optical band gap in colored state to improve the transmittance modulation. Thus, the new film can be a competitive electrochromic material to enhance the performances of the electrochromic device.