A complementary electrochromic device with highly improved performance based on brick-like hydrated tungsten trioxide...

Area of Science:

• Materials Science
• Nanotechnology
• Electrochemistry

Background:

• Developing advanced materials for electrochromic devices is crucial for energy-efficient applications.
• Tungsten trioxide (WO3) based materials are promising candidates due to their tunable optical properties.

Purpose of the Study:

• To synthesize uniform and well-adhesive nanostructured hydrated tungsten trioxide (WO3·H2O) films.
• To investigate the influence of synthesis parameters on film morphology and properties.
• To evaluate the electrochromic performance of the synthesized films and a complementary device.

Main Methods:

• Facile and template-free crystal-seed-assisted hydrothermal synthesis.
• Characterization using X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and High-Resolution Transmission Electron Microscopy (HRTEM).
• Fabrication and testing of an electrochromic device incorporating WO3·H2O and Prussian blue.

Main Results:

• Orthorhombic structured WO3·H2O films composed of brick-like nanostructures were successfully grown on FTO substrates.
• The films demonstrated good cyclic stability, comparable switching speed, and a coloration efficiency of 30.1 cm2 C−1.
• The complementary electrochromic device showed significantly improved color contrast and response times (1.8 s coloration, 3.7 s bleaching) with a high coloration efficiency of 164.6 cm2 C−1.

Conclusions:

• The crystal-seed-assisted hydrothermal method is effective for producing high-quality nanostructured WO3·H2O films.
• The synthesized WO3·H2O films exhibit promising electrochromic properties suitable for device applications.
• The complementary device demonstrates enhanced performance, highlighting the potential of this material system.