Thermoelectric properties of flexible PEDOT:PSS-based films tuned by SnSe via the vacuum filtration method

Abstract

In this study, flexible thermoelectric tin selenide (SnSe)/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) composite films have been fabricated by the vacuum filtration method, and their thermoelectric properties were investigated. The electrical conductivities of the composite films have a tendency to decrease with an increase in the SnSe content, while their Seebeck coefficients have an inverse tendency. The electrical conductivities decrease gradually with an increase in temperature, while the Seebeck coefficients show a tendency to increase first and then decrease with the increase in temperature. The maximum power factor (PF = S²σ) of the composite film is obtained when the SnSe content is 10 wt%, which is 24.42 μW m⁻¹ K⁻² at 353 K. Besides, the 10 wt% SnSe/PEDOT:PSS film exhibited excellent stability with only a 9% increase in resistance after 1000 bends under a bending radius of 4 mm. When the temperature gradient is 50 K, a flexible thermoelectric generator fabricated by 3 legs of the 10 wt% SnSe/PEDOT:PSS film has an open-circuit voltage and maximum output electrical power of 3.2 mV and 13.73 nW, respectively, which demonstrates a great potential application to power wearable flexible electronic devices.