High thermoelectric performance of flexible Ag/Ag2Se composite film on nylon for low-grade energy harvesting

In this work, Ag/Ag2Se composite films with excellent thermoelectric (TE) properties and flexibility are prepared based on a simple one-pot method. By adjusting the nominal ratios of Ag/Se, an optimal Ag/Ag2Se composite film shows a large power factor of ∼2275 μW m−1 K−2 at 300 K. Such an outstanding TE performance of the composite film is due to the unique microstructure and the synergistic effect between the Ag and Ag2Se. Meanwhile, the composite film also shows outstanding flexibility (∼91.8% of the initial electrical conductivity is maintained, and the S is unchanged after 1500 bending cycles with a bending radius of 4 mm). Furthermore, a 4-leg flexible TE generator assembled with the optimal film produces a voltage of 14.06 mV and 4.96 μW at a temperature difference of 30.4 K. This work provides a new inspiration for the preparation of flexible Ag2Se-based films with excellent TE performance near room temperature.