Printed Multicolor High-Contrast Electrochromic Devices.
In this study, electrochemical responses of inkjet-printed multicolored electrochromic devices (ECD) were studied to evaluate the feasibility of presenting multiple colors in one ECD. Metallo-supramolecular polymers (MEPE) solutions with two primary colors were inkjet-printed on flexible electrodes. By digitally controlling print dosages of each species, the colors of the printed EC thin film patterns can be adjusted directly without premixing 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 ECD. After applying a dc voltage, the printed ECDs exhibited great contrast with a transmittance change (ΔT) of 40.1% and a high coloration efficiency of 445 cm(2) C(-1) within a short darkening time of 2 s. The flexible ECDs also showed the same darkening time of 2 s and still had a high ΔT of 30.1% under bending condition. This study demonstrated the feasibility to fabricate display devices with different color setups by an all-solution process and can be further extended to other types of displays.
Bo-Han
BH
Chen
Sheng-Yuan
SY
Kao
National Institute of Advanced Industrial Science and Technology (AIST) , Anagahora 2266-98, Shimoshidami, Moriyama-ku, Nagoya 463-8560, Japan.
Chih-Wei
CW
Hu
National Institute for Materials Science , 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
Masayoshi
M
Higuchi
Kuo-Chuan
KC
Ho
Ying-Chih
YC
Liao
electrochromic devices; flexible electronics; inkjet printing; metallo-supramolecular; multicolor patterning