Facile self-supporting and flexible Cu2S/PEDOT:PSS composite thermoelectric film with high thermoelectric properties for body energy harvesting

Abstract

The self-supporting and flexible Cu2S/poly(3,4-ethylene dioxythiophene):-poly(styrene sulfonate) (PEDOT:PSS) composite thermoelectric films were prepared by vacuum filtration method. The effects of Cu2S content and the pressure of cold-pressing on the thermoelectric properties of composite films were studied. The electrical conductivities of Cu2S/PEDOT:PSS composite films would decrease with the increase of Cu2S content and temperature, while the Seebeck coefficients had an inverse tendency. At the same time, the electrical conductivities and Seebeck coefficients of the Cu2S/PEDOT:PSS composite films will decrease and increases with the increase of temperature, respectively. The maximum power factor (PF) of composite films was 56.15 μWm-1K−2 when Cu2S content was 10 wt% at 393 K. After cold-pressing at 2 MPa or 4 MPa, the PF of 10 wt% composite film was enhanced by two times. The resistance of the cold-pressed composite film would rise only 10 % after bending 1000 cycles under a bending radius of 4 mm, showing good flexibility. The open-circuit voltage and maximum output power were 2.3 mV and 23.06 nW for the TE generator fabricated by four strips of cold-pressed 10 wt% composite film at the temperature difference of 30 K, respectively, which has a good potential to power the low-power consumption wearable electronic devices.