Printed Multicolor High-Contrast Electrochromic Devices

Abstract

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.

Interfacial redox centers as origin of color switching in organic electrochromic device

“…A 50 % transparency in the second cycle onwards has been considered as OFF state whereas ON state corresponds to 100 % transparency. Additionally, contrast between the ON and OFF states can be calculated by defining colour contrast ratio (CCR) using the following equation [35][36][37].…”

Inkjet Printing of Functional Materials for Optical and Photonic Applications

“…Besides the formation of bicolour images, digital control of the deposition of the two inks in dot arrays with different red and blue dot ratio allows us to create areas with various colours without the need of premixing or new material synthesis (Figure 20) [180]. More recently, the group of Reynolds at the Georgia Institute of Technology has developed Cyan/Magenta/Yellow to colourless electrochromic inks based on alkoxy-functionalized poly(3,4-propylenedioxythiophene)-based polymers.…”

Redox‐Active Peptide‐Functionalized Quinquethiophene‐Based Electrochromic π‐Gel

“…[39] Stupp et alr eporteds elf-assembly of quinquethiophenesf unctionalizedw ith b-sheet formingp eptide, which formed 1D nanostructure in aqueouss olution. [40] Successfula pplicationso fe lectrochromicd evices (ECD) [41][42][43][44] include smarts unglasses, [45][46] smart-window, [47][48][49] stretchablee lectronic skin, [50] ande lectrochromic displayd evices. [51] Among the varietieso fs mall molecular and polymerico rganic electrochromic materialsu sedi ne lectrochromic devices, oligothiophenesa sw ella s polythiophene derivatives area ni mportant classo fp-conjugated organic material.…”