Optimization of the Thermoelectric Properties of 2D-PEDOT Derivative Chains Using Electrochemical Control

Abstract

Conductive organic-based thermoelectric generators are very effective in collecting electricity from waste heat with lowtemperature gradients compared to ambient conditions. Although studies have been conducted to improve thermoelectric characteristics by doping conducting polymers, the thermoelectric performances achieved by accurately controlling the doping level of polymer chains are currently inadequate. Here, we report changes in thermoelectric performance of three-armed cross-linker introduced poly(3,4-ethylenedioxythiophene) (PEDOT) derivative two-dimensional (2D) chain using electrochemical oxidation level control. The charge carrier density of PEDOT derivative films increased with more positive potentials (from 0.7 × 10 20 to 4.24 × 10 21 ) and was precisely controlled by varying potentials. Thermoelectric properties such as electrical conductivity, carrier mobility, and Seebeck coefficients were also manipulated through the application of different potentials. The power factor of the PEDOT derivative 2D chain was improved to 72.6 μW m −1 K −2 at +0.6 V, which was much higher than that of a neutral state at −1.4 V (5.1 × 10 −2 μW m −1 K −2 ).

Electrochemically exfoliated covalent organic frameworks for improved photocatalytic hydrogen evolution

“…1,3,5-Tri(thiophen-2-yl)benzene (TTB), a dendritic rigid π-conjugated molecule, was usually used as a cross-linker to synthesize star-shaped conjugated polymers, which afford high electron and hole mobility. 20,21 With high structural symmetry, three-armed TTB has been gradually recognized as an appropriate building block for novel thiophene-COFs. 22 As shown in Fig.…”