Electrochromism in Nanoporous Tungsten Trioxide Films Prepared through Anodization and Thermal Oxidation

Abstract

Nanoporous WO₃ films were prepared via anodization and thermal oxidation from a sputtered dense W film on FTO glass at different anodization times producing WO₃ films with different porosities. Moreover, an oxidation time of 1 h at 450 °C modified the crystallinity and optical transmittance in the nanoporous WO₃ films. The crystallinity of the nanoporous WO₃ films decreased as anodization time increased. The films’ electrochromic properties also improved considerably. Results showed that an anodization time of 12 min is optimal to synthesize nanoporous WO₃ films with the best electrochromic properties and highest optical modulation.

Keywords:

• sputtering
• anodization
• nanoporous
• electrochromic
• WO₃ films

Acknowledgments

The authors would like to thank the Division of Physics, Faculty of Science and Technology, Rajamangala University of Technology Thanyaburi and the National Electronics and Computer Technology Center (NECTEC) for providing the experimental facilities.

Additional information

Funding

This study was supported by the Thammasat University Research Fund, Contract No. TUFT 032/2563.