Self-powered PEDOT: PSS/CSWCNT/Mxenes thermoelectric films and wearable electronics devices

In this work, Ti3C2-Cl is introduced into poly(3,4-ethylenedioxythiophene): poly(4-styrenesulfonic acid) / single-walled carbon nanotubes (PEDOT: PSS/SWCNT, noted as PPSC) films to prepare ternary thermoelectric films of PEDOT: PSS/SWCNT/Ti3C2-Cl (PPSCT). The microscopic morphology, structures, and thermoelectric properties of PPSC and PPSCT films show that the introduction of Ti3C2-Cl results in a tendency of decreasing electrical as well as thermal conductivity, and the Seebeck coefficient is increased. When the content of Ti3C2-Cl reaches 8 wt%, the conductivity, Seebeck coefficient, and thermal conductivity of the PPSCT films reach the optimum values of 1683 S/cm, 21.69 μV/K, and 14.97 W/mK, respectively, and the power factor (PF) and thermoelectric figure of merit (ZT) are 79.23 μW/mK2 and 1.58 × 10-3. The UPS and Hall effect results reveal that the improvement of the Seebeck effect of PPSCT mainly results from the ternary interfacial energy barrier as well as the change of carrier concentration. In addition, the wearable electronics devices demonstrate an output voltage of 4.5 mV and an output power of 54.36 nW under a 50 K temperature difference. The device displays a good monitoring sensitivity by reaching an output voltage of 0.6 mV at a 7 K temperature difference between the skin and the environment.