State‐of‐the‐Art Neutral Tint Multichromophoric Polymers for High‐Contrast See‐Through Electrochromic Devices

Abstract

Two new multichromophoric electrochromic polymers featuring a conjugated EDOT/ProDOT copolymer backbone (PXDOT) and a reversible Weitz-type redox active small molecule electrochrome (WTE) tethered to the conjugated chain are reported here. The careful design of the WTEs provides a highly reversible redox behavior with a colorless red switching that complements the colorless blue switching of the conjugated backbone. Subtractive color mixing successfully provides high performing solution processable polymeric layers with colorless neutral tint switchable limiting states for application in see-through electrochromic devices. Design, synthesis, comprehensive chemical and spectroelectrochemical characterization as well as the preparation of a proof-of-concept device are discussed.

New Roll‐to‐Roll Processable PEDOT‐Based Polymer with Colorless Bleached State for Flexible Electrochromic Devices

“…Funct. [11,24] The ISP-manufactured PEDOT-EthC6 film is significantly thicker than the electrochemically polymerized PEDOT-EthC6 thin films, which leads to a higher CR. 2020, 30,1906254 polymerization section, shown in Figure 4C.…”

“…[3,[8][9][10][11] Conjugated EC polymers (ECPs), such as poly(3,4-ethylene dioxythiophene) (PEDOT), are generally compatible with high-throughput processes, e.g., roll-to-roll (R2R) deposition. [14,24] The residual coloration only becomes acceptable in the case of very thin films, but this comes at the expense of sufficient darkening in the colored state. [12][13][14][15][16][17] Furthermore, ECPs feature a wide range of vivid colors, response times in the range of seconds, and light transmittance change over 60%.…”

“…These outstanding EC properties result from an extended conjugated π-electron system. [18,24] To date, the best EC material in terms of synthetic simplicity, color neutrality in the bleached state, light transmittance change, and compatibility with high-throughput deposition techniques remains a poly(3,4-propylene dioxythiophene) (ProDOT) derivative. Therefore, most ECPs are tunable by tailoring the structure through synthetic modification, which provides the opportunity to diversify and control the redox behavior or the processing of the ECPs.…”

Low‐Bandgap Polymers for High‐Performance Photodiodes with Maximal EQE near 1200 nm and Broad Spectral Response from 300 to 1700 nm

“…Donor–acceptor (D–A) conjugated polymers with various chemical structures have drawn keen attractions for applications in solar cells, thin field‐effect transistors, light‐emitting diodes, electrochromic devices, and optical sensors . Polymer photodiodes can meet the demands of low cost, simple structures, solution fabrication, tunability of structures and properties, light weight, abundant material selectivity, mechanical flexibility, and room temperature operation, which are usually difficult for inorganic semiconductor photodiodes to match .…”

Visible and near-infrared electrochromic thiophene–diketopyrrolopyrrole polymers

“…[3][4][5][6] To date, blue-, green-, magenta-, redcolored and black EC polymers have been reported. [7][8][9][10] In addition, conjugated polymers that are able to switch reversibly between colored and transparent states in both visible and nearinfrared (NIR) regions by electrochemical means are reported.…”