Electrochromic thin film of Prussian blue nanoparticles fabricated using wet process

Electrochromic thin films of Prussian blue nanoparticles were developed using wet processing. The resultant alkyl-ligand covered nanoparticles disperse well in organic solvents. Consequently, various conventional coating and printing methods can be used in high-quality micro-fabrication to prepare electronic devices. We examined electrochromic properties of the thin film fabricated using spin-coating method. Electrochromism of the thin film on an indium tin oxide (ITO) electrode was observed. The color changes from blue to colorlessness reversibly at potentials between +0.6 to -0.4 V. Furthermore, various patterns were printed on ITO substrates using photolithography, indicating potential application of this approach to information displays and smart windows.