Designing a Soluble PEDOT Analogue without Surfactants or Dispersants

Abstract

Copolymerization of alkoxy-functionalized 3,4-propylenedioxythiophenes (ProDOTs) with unfunctionalized 3,4-ethylenedioxythiophenes (EDOTs) in varying ratios using direct arylation yields a series of solution processable polymers with highly tunable optical and electronic properties. Within this series, we have identified ProDOT−EDOT 2 , a copolymer containing 67% EDOT compositionally, that combines the low oxidation potential, the redox behavior, and the deep-blue neutral color that are characteristic of PEDOT with the high solubility, exceptional electrochromic contrast, and color neutrality in the oxidized state characteristic of alkoxy-functionalized PProDOTs.

Conductive, Solution‐Processed Dioxythiophene Copolymers for Thermoelectric and Transparent Electrode Applications

“…Energy Mater. [19,23,43,46,47] This difference between the color neutrality of oxidized PE 2 and PEDOT has been previously investigated [19] and can be quantitatively observed by comparing the colorimetry of doped PE 2 films, either with ( Figure 3b) or without ( Figure S4b, Supporting Information) an oxidized film of PProDOT, with the reported values for PEDOT:PSS. This switching is reversible, albeit somewhat slower compared to using an ITO electrode due to the lower conductivity of doped PE 2 ( Figure S7, Supporting Information).…”

“…We hypothesize that this is due to a) the removal of some side chain density from PProDOT to P 2 E; this is expected since branched alkyl chains add insulating material that may disrupt π-π stacking and limit charge transport between chains without providing increased long range order as some linear chains do, and b) the reduced ring size of EDOT which places the electron lone pair in a more ideal orientation for π-donation into the thiophene Adv. [18,19] The second lone pair of electrons on the oxygen atom engage in through-space noncovalent interactions [35] with the adjacent sulfur atoms leading to minimal twisting between rings. 2019, 9,1900395 ring relative to ProDOT.…”

“…Another manifestation of this was previously observed for PProDOT, with smoother spin and bladecoated films requiring a larger charge to switch and exhibiting a higher electrochromic contrast compared to rougher spray-coated films. Optical gaps and oxidation potentials [18,19] of the P x E y polymer series along with electrical conductivity values and Seebeck coefficients of polymer films after doping with Ni(tfd) 2 for 10 min. [39] Using blade coating as the optimized casting method for PE 2 , various dopants were then tested (via solution doping for the same time period) and the thermoelectric properties were compared, as shown in Figure 2.…”

“…[18,19] Additionally, the broad electroactive response of the high EDOT content polymers in the ProDOT x -EDOT y (P x E y ) series has led to them being effective as capacitive materials for charge storage applications. These materials have exceptional electrochromic properties with high contrast in the visible region and, upon reversible electrochemical doping, exhibit color-neutral oxidized states with rapid switching times.…”

A new high‐performance blue to transmissive electrochromic material and use of silver nanowire network electrodes as substrates

“…The solution processable material P1C showed almost 50% optical contrast (at 568 nm, Fig. ) which, to best of our knowledge, is the second highest reported for a solution processable blue to transmissive material, following the work by Reynolds group that was recently published while this manuscript was being prepared . There is one other report that shows 50% optical contrast for a blue material; however, this polymer shows a significant yellow color at the oxidized state due a remaining tail between 480 and 350 nm in the visible region .…”