Printed Multi-Color High-Contrast Flexible Electrochromic Devices

In this thesis, multi-colored electrochromic (EC) thin film devices were prepared by a direct-writing method. Metallo-supramolecular polymers (MEPE) solutions with two primary colors were inkjet-printed digitally on flexible electrodes. Uniform EC thin films are fabricated via inkjet printing. Further, by digitally controlling print dosages of each species, colors of the printed EC thin film patterns can be adjusted directly without pre-mixing or synthesizing new materials. The printed EC thin films were then laminated with a solid transparent thin film electrolyte and a transparent conductive thin film to form an electrochromic device (ECD). After applying a DC voltage, the printed ECDs exhibited a great contrast with a transmittance change (ΔT) of 40.1% and a high coloration efficiency of 445 cm2C-1 at 580 nm within a short darkening time of 2 s. The flexible ECDs can also be made base on ITO-PEN and showed same darkening time of 2 s and still have a high ΔT of 30.1% under bending condition. In summary, this study demonstrated the feasibility to fabricate display devices with different color set up by all-solution process, and can be further extended to other types of displays.