Preparation and Characterization of Screen-Printed Cu2S/PEDOT:PSS Hybrid Films for Flexible Thermoelectric Power Generator
Junmei Zhao, Xiaolong Zhao, Rui Guo, Yaxin Zhao, Chenyu Yang, Liping Zhang, Dan Liu, Yifeng Ren
Abstract
In recent years, flexible thermoelectric generators(f-TEG), which can generate electricity by environmental temperature difference and have low cost, have been widely concerned in self-powered energy devices for underground pipe network monitoring. This paper studied the Cu2S films by screen-printing. The effects of different proportions of p-type Cu2S/poly 3,4-ethylene dioxythiophene-polystyrene sulfonate (PEDOT:PSS) mixture on the thermoelectric properties of films were studied. The interfacial effect of the two materials, forming a superconducting layer on the surface of Cu2S, leads to the enhancement of film conductivity with the increase of PEDOT:PSS. In addition, the Seebeck coefficient decreases with the increase of PEDOT:PSS due to the excessive bandgap difference between the two materials. When the content ratio of Cu2S and PEDOT:PSS was 1:1.2, the prepared film had the optimal thermoelectric performance, with a maximum power factor (PF) of 20.60 μW·m−1·K−1. The conductivity reached 75% of the initial value after 1500 bending tests. In addition, a fully printed Te-free f-TEG with a fan-shaped structure by Cu2S and Ag2Se was constructed. When the temperature difference (ΔT) was 35 K, the output voltage of the f-TEG was 33.50 mV, and the maximum power was 163.20 nW. Thus, it is envisaged that large thermoelectric output can be obtained by building a multi-layer stacking f-TEG for continuous self-powered monitoring.