Enhancing Recoverable Bendability in High-Performance Ag₂Se-Based Thermoelectrics through Plastic Processing

Urgent demand for a sustainable power supply for wearables promotes great efforts on the development of flexible thermoelectric devices. The elastic bendability allows the reservation of initial power and flexibility in inorganic thermoelectric films. The elasticity is related to the thickness engineeringly and the elastic strain scientifically, therefore guiding this work to focus on developing elastic thermoelectric generators using high-performing orthorhombic Ag2Se1–xSx films that thinned the bulks through multipass hot-rolling at ∼393 K. Such a plastic deformation enables a creation of dense dislocations and a refinement of grain and, thereby, a dramatic increase in the elastic strain, impressively securing a full recoverability in transport properties for the obtained films even after 100,000 times bending within a radius down to ∼3 mm. The resultant achievement of extraordinary specific power density of ∼5 μW/cm-K2 in a six-leg flexible device robustly demonstrates these alloys as a potentially sustainable power source for wearable electronics.