Fig. 6: Flexibility of Te-doped Ag₂Se thin films and their device performance.

Measured ΔR/R₀ of the Ag₂Se thin films with 3.2 at.% Te (a) without and (b) with a vinyl-laurate-based coating at different bending radii and bending cycles. The inset in (b) shows a photo of the flexible thin film. c Measured contact resistivity ρ_c between coated Ag₂Se thin film with 3.2 at.% Te and different electrode materials. d Measured open-circuit voltages and output powers of the device as a function of loading current at different temperature differences (ΔTs). e Determined output power densities at different ΔTs. The inset shows the photo of a flexible device composed of one pair of coated Ag₂Se thin film with 3.2 at.% Te as an n-type leg and coated Sb₂Te₃ thin film as a p-type leg. f Voltage of wearing the as-fabricated device for sitting, walking, and running as a function of time.