| 초록 |
Sequential doping and dedoping increased the conductivity and optimized the oxidation level of transparent and flexible poly(3,4-ethylenedioxythiophene):poly(4-styrene sulfonic acid) (PEDOT:PSS) films, resulting in an improvement in the thermoelectric figure of merit ZT. During the chemical dedoping process, σ of the films continuously decreased from 1647 to 783 S/cm due to a decrease in the carrier concentration, whereas the Seebeck coefficient (S) steeply increased from 28 to 49.3 µV/K at the optimum oxidation level. A power factor of 318.4 µW/mK2 (σ = 1310 S/cm, S = 49.3 µV/K), the highest among all existing thermoelectric electrodes, was achieved while maintaining polymer film flexibility and transparency (88.3 % of optical transmittance). In addition, the thermal conductivity (k) of the PEDOT:PSS films decreased from 0.38 to 0.30 W/mK upon removal of the PSS. At the lowest k value, a high ZT value of 0.31 was achieved at room temperature. |
