Abstract
Developing free-standing flexible thermoelectric films (FFTEFs) is substantial for improved highly efficient utilization of waste heat from irregular surfaces. However, current high-performance TE films are substrate-dependent with limited flexibility and high cost, while FFTEFs generally show inferior TE performance. Herein, free-standing Ag2Se/carbon flexible composite films were prepared by scalable screen-printing followed by facile annealing. A resulting best film presents a remarkable room-temperature power factor of 1761 μW m−1 K−2, mainly deriving from well-crystallized Ag2Se grains. Strong interfacial and defective phonon scattering resulted in a low thermal conductivity of 0.66 W m−1 K−1 at room temperature to achieve a zT value of 0.81. The film shows excellent flexibility (electrical conductivity reduction of less than 10 % after 3000 bending cycles at a 4 mm radius), mainly because the carbon content and Ag2Se grains grown along the (00 l) planes exhibit a gradient distribution along the out-of-the-plane direction. A four-leg TE device assembled with the film outputs a maximum power of 5.5 μW (corresponding power density of 22.9 W m−2) at a temperature difference of 31.4 K and possesses great flexibility. This work develops an effective strategy for fabricating high-performance free-standing flexible thermoelectric films.Details
| Publication | Nano Energy, Volume 138, id.110836 |
| Publication Date | June 2025 |
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| Bibcode | 2025NEne..13810836Z |
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