Flexible Bi2Te3/PEDOT nanowire sandwich-like films towards high-performance wearable cross-plane thermoelectric generator and temperature sensor array

Abstract

It is of significance to develop high-performance organic/inorganic hybrid thermoelectric (TE) materials for flexible cross-plane TE devices. In this work, we synthesize a flexible and free-standing sandwich-like TE film by depositing Bi₂Te₃ nanocrystals into a conducting porous PEDOT nanowire scaffold. The mechanically robust Bi₂Te₃@PEDOT nanowire film exhibits a record Seebeck coefficient of 266.4 μV K⁻¹ with a corresponding power factor of 740.2 μW m⁻¹ K⁻² and a zT value of 0.27 at room temperature. Afterwards, we build new types of wearable cross-plane TE generator (TEG) and TE-powered temperature sensor array with a reduced number of electric leads in comparison to traditional designs. The TEG shows a maximum output power density of 3.48 μW cm⁻² at a temperature difference of 17.8 K (predicted output power density of 70.6 μW cm⁻² at ΔT = 80 K), outperforming most of the organic and organic/inorganic based ones. The conformal TE-powered temperature sensor array exhibits high and stable thermal sensitivity with a resolution of 0.05 K.