Enhanced performance of SnSe/PEDOT: PSS composite films by MWCNTs for flexible thermoelectric power generator

Flexible multiwall carbon nanotubes (MWCNTs)− 10 wt% tin selenide (SnSe)/poly (3,4- ethylene dioxythiophene): poly (styrene sulfonate) (PEDOT: PSS)/5 vol% dimethyl sulfoxide (DMSO) (MSPPD) composite films were fabricated by vacuum filtration method, and their thermoelectric properties were investigated. When the electrical conductivity (σ) and Seebeck coefficient (S) of these composite films with different contents of MWCNTs were measured at different temperatures, σ had an increasing tendency with the increase of MWCNTs content while S would decrease gradually. MWCNTs would improve carrier concentration (n) and mobility (μ) of SnSe/PEDOT: PSS film simultaneously because of MWCNTs with high electrical conductivity and carrier mobility. The maximum power factor PF of 59.35 μWm⁻¹K⁻² had been obtained for MSPPD10 composite film at 393 K. The MSPPD10 composite film exhibited ex-cellent flexibility, σ decreased only to 86% of its initial stage after bending 1000 cycles using a rod with a radius of 4 mm. A flexible thermoelectric (TE) generator consisting of 5 legs MSPPD10 could generate an open-circuit voltage of 3.73 mV and maximum output power of 14.74 nW when the temperature gradient was 39 K. This research shows that MWCNTs have great potential to enhance the thermoelectric performance of flexible SnSe/PEDOT: PSS composite films for wearable devices.