Extending the Color Retention of an Electrochromic Device by Immobilizing Color Switching and Ion-Storage Complementary Layers

Abstract

The thermal polymerization of a bis(triphenylamine)-bis(styrene) monomer on ITO coated glass gave an electroactive film that underwent two stepwise oxidations. The perceived color change of the film upon stepwise oxidation was colorless-to-yellow followed by yellow-to-blue. The anodic cyclic voltammogram of the monomer was consistent over multiple cycles. The immobilized film could be reversibly switched between its colorless and blue states with applied potential in both a half- and full-electrochromic functioning device. The devices could also reversibly switch their colors upwards of 6 h. The retention of the electrochemically induced blue color was contingent on the device architecture. Upwards of 80% of the color was maintained 30 min after the potential was turned off with the double-layer electrochromic device structure. This device was prepared from two electroactive layers: a bis(triphenylamine) and viologen-based polymers that were immobilized on the electrodes. In contrast, 50% of the color of the active electrochromic device that was prepared from a single electroactive layer bleached 7 min once the potential was no longer applied.

Electrochemistry and Electrochromic Performance of a Metallopolymer Formed by Electropolymerization of a Fe(II) Complex with a Triphenylamine‐Hydrazone Ligand

“…This means that to keep the colored state of the polymer voltage should be applied constantly. The color memory properties of materials can be improved by the change of the device architecture by addition of complementary ion storage layer, [56,57] ion exchange membrane [58] or the use of charge trapping nanomaterials inside the active EC layer [59] . The stability of polymer during multiple oxidation/reduction cycles was done by switching the potential between +1.5 V and −0.1 V with 30 s interval and the transmittance at 770 nm of the polymer was monitored as a function of time (Figure 8C).…”

Suitability of alkyne donor-π-donor-π-donor scaffolds for electrofluorochromic and electrochromic use

“…Their use in operating devices is further spurred on by their color switching between their neutral and oxidized states which produces distinctive color changes. [19][20][21][22] The optoelectronic properties of triphenylamines can be enhanced by conjugating them with various p-electron groups. This strategy has been adopted to prepare highly emissive derivatives.…”