High-performance, thin-film thermoelectric generator with self-healing ability for body-heat harvesting

Flexible thermoelectric generators (TEGs) are attractive for their ability to power wearable electronics utilizing the temperature difference between the human body and the environment. Here, we present a self-healing flexible TEG assembled with high-performance Ag₂Se films. A room temperature power factor (PF) as high as 20.8 μW cm⁻¹ K⁻² is obtained via isoelectronic copper doping. The relative resistance change of the film is less than 5% of the initial value after 1,000 bending cycles, and the resistance of the Ag₂Se film recovers to its initial value within a few hours of the bending test. The 6-leg flexible TEG demonstrates a maximum power density of 80 W m⁻² at a temperature difference of 50 K. An output voltage of 1.5–2.8 mV can be achieved on the arm in different motion states. These results demonstrate the promising application of Ag₂Se-based flexible TEGs for wearable electronics.