초록 |
The disorder of highly doped conjugated polymers is a crucial factor for charge transport as it impinges on a molecular geometry or electronic coupling which is relevant to orbital overlap. Thus, how the disorder affects the charge transport in doped polymer systems should be investigated in microscopic aspect for high thermoelectric (TE) performance. We evaluate the TE charge transport phenomena of the poly(3,4-ethylenedioxythiophene) (PEDOT) interacted with multi-cyano functionalized counter-ions using ion exchange method. The result shows distinctly different states in the aspects of molecular ordering, energetic disorder, and polaron behavior depending on their degree of the disorder. Consequently, the PEDOT film with the lowest degree of disorder exhibits a remarkable power factor of 630.6 μW·m−1·K−2 and figure-of-merit ZT of 0.21. This work provides a comprehensive understanding of counter-ion-induced disorder effect on charge transport in terms of optimizing TE performance. |