High performance electrochromic devices based on WO3TiO2 nanoparticles synthesized by flame spray pyrolysis

We demonstrate high performance WO3TiO2 nanoparticles synthesized by flame spray pyrolysis for the applications in electrochromic devices (ECDs). It is shown that the post-annealing process significantly improves the crystallinity of WO3TiO2 nanoparticles. The WO3TiO2 nanoparticles exhibit a much higher transmittance compared to the conventional TiO2 nanoparticles. The optimized WO3TiO2 nanoparticles are successfully adopted to the electrochromic devices. The WO3TiO2-based ECDs show a higher transmittance than the TiO2-based ECDs due to the high transmittance of WO3TiO2. In addition, the electrochromic response of the WO3TiO2-based ECDs is much faster than that of the TiO2-based ECDs. The WO3TiO2-based ECDs show a much higher reflective property compared to the TiO2-based ECDs at the mirror state. These results indicate that the high performance WO3TiO2 nanoparticles synthesized by a simple one-step flame spray pyrolysis process can be a promising material for highly efficient ECDs.