Preparation and characterization of the Ag2Se flexible films tuned by PVP for wearable thermoelectric generator

In recent years, the demand for wearable devices has promoted the research of flexible thermoelectric generators. Herein, this work reports a facile method to prepare the flexible Ag 2 Se/polyvinyl pyrrolidone (PVP) composite films. The Ag 2 Se nanorods are synthesized by the template method and then mixed with PVP solution to form the composite film optimized by the content of Ag 2 Se. The maximum power factor of the film is 16.18 µW m −1  K −2 at 320 K, and the thermoelectric generator (TEG) has an output voltage and power of 5.49 mV and 55.57 nW at a temperature difference of 40 K, respectively. Moreover, the Ag 2 Se/PVP film has good flexibility and can withstand multiple bending, the electrical conductivity reaching 89.8% and 76 % at 500 and 1000, respectively. PVP has an excellent protective capabilities effect so that the TE performance can remain stable in 40 days, and then the electrical conductivity only drops to 89 % of the initial value at 50 days. This work provides an effective method for preparing wearable thermoelectric devices, which can be extended to other composite materials.