Micropatterned PEDOT with Enhanced Electrochromism and Electrochemical Tunable Diffraction

Abstract

Micro–nanofabrication of conductive polymers (CPs) with functional structures is in great demand in organic electronic devices, micro-optics, and flex sensors. Here, we report the fabrication of micropatterned poly­(3,4-ethylenedioxythiophene) (PEDOT) and its applications on flexible electrochromic devices and tunable diffractive optics. The localized electropolymerization of 3,4-ethylenedioxythiophene at the electrode/agarose gel stamping interface through an electrochemical wet stamping (E-WETS) technique is used to fabricate PEDOT with functional microstructures. PEDOT microdots, micro-rectangles, and interdigitated array microelectrodes are fabricated with submicron tolerance and ∼2 μm smallest feature size. Furthermore, the flexible PEDOT electrochromic devices consisting of the logo of Xiamen University are fabricated with a reversible switch of absorptivity. The improved optical and coloration–amperometric responses of electrochromism are demonstrated because of the enhanced charge transport rate of the micropatterned PEDOT. The electrochromism of the 2D PEDOT micropatterns is further used as a binary diffractive optical element to modulate the intensity and efficiency of diffracted 2D structural light because of the switchable absorptivity during doping and dedoping processes. When the potential is switched from 1 to −1 V to tune the absorptivity at ∼600 nm from low to high, the intensity of zero-order diffraction light spot decreases with the intensity of other order diffraction light spots increasing dramatically. The results demonstrate that E-WETS provides an alternative method for the fabrication of CPs with functional micro–nanostructures. The electrochemical tunable diffraction with high reversibility and fast response is of potential applications in micro-optics and flex sensors.

Micropatterned Poly(3,4-ethylenedioxythiophene) Thin Films with Improved Color-Switching Rates and Coloration Efficiency

“…Additionally, the mPEDOT thin films have higher CE than the PEDOT thin films. These results suggest that micropatterning of a PEDOT thin film could preserve its transmittance modulation ability and, at the same time, increase its coloring-switching rates and CE [ 19 , 26 ]. It is envisaged that such a strategy could serve as a promising method to improve the performance of electrochromic thin film electrodes.…”

“…Efforts have been attempted to improve the coloring-switching rate of PEDOT electrodes, such as structure modifications [ 12 , 13 , 14 ] or incorporating other species [ 15 , 16 , 17 ]. Micropatterned PEDOT electrodes have been sporadically studied for sensor applications or optical properties [ 18 , 19 ]. Various methods have been employed for the fabrication of conjugated polymers, such as electropolymerization [ 20 ], oxidative chemical vapor deposition [ 21 ], and vapor phase polymerization [ 22 ].…”

Pruney Finger-Inspired Switchable Surface with Water-Actuated Dynamic Textures

“…Textured surfaces are ubiquitous and closely related to some special physical properties. − Varied surface microstructures endow creatures with impressive and specific properties including adhesion, , wetting, − optical diffraction, , propulsion effects, − and so forth. Of particular interest are dynamic surfaces capable of switching between two or more distinct states.…”

Dynamic Spectral Modulation Enabled by Conductive Polymer-Integrated Plasmonic Nanodisk-Hole Arrays

“…Presently, the dynamic modulation of plasmonic devices is mainly realized by external stimuli, such as electric field, optical field, gas, pH changes, etc. These dynamically regulated approaches are mainly divided into two categories: one is to change the material properties of the metal nanostructures themselves, such as the reversible electrodeposition of metals and metal hydride; the other is to change the surrounding environment of metal nanostructures, such as liquid crystals and conductive polymers. − Among them, conductive polymers are prime candidates to regulate the plasmonic properties of metal nanostructures because of their outstanding advantages of nanometric-thickness film, millisecond-scale response time, broadband spectral response, excellent electrical switching stability, etc . Conductive polymers under different voltages are in diverse oxidation–reduction states, corresponding to different energy bandwidths and extinction coefficients (absorption).…”