Wang Ruoxi,Sun Rongke,Ren Yanmei,Ma Yanqing,Ma Lei
There is still limited research on the influence of polymer content in inorganic/organic materials on thermoelectric properties. In this study, we systematically investigated the influence of the content of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) in the Ag 2 Se nanowires/PEDOT:PSS (Ag 2 Se NWs/PEDOT:PSS) composite films on the thermoelectric properties. When the content of PEDOT:PSS is 1.54 wt%, the composite film achieved the highest power factor (PF) of ~ 2074.0 µW m −1 K −2 at room temperature. The maximum output power ( P max ) of the single-leg thermoelectric device based on the composite film is approximately 49.42 nW, and the maximum power density (PD max ) is 4.28 W m −2 at a temperature difference of 25 K. Furthermore, the film exhibits superior flexibility with 94.3% of the original performance retention after 2000 bending cycles around a rod with a diameter of 5 mm. This work provides valuable guidance for the design and fabrication of high-performance flexible inorganic/organic composite thermoelectric materials.
Flexible thermoelectric materials and devices hold enormous potential for wearable electronics but are hindered by inadequate material properties and inefficient assembly techniques, leading to suboptimal performance. Herein, we developed a flexible thermoelectric film, comprising Ag 2 Se nanowires as the primary material, a nylon membrane as a flexible scaffold, and reduced graphene oxide as a conductive network, achieving a record-high room-temperature ZT of 1.28. Hot-pressed Ag 2 Se nanowires exhibited strong (013) orientation, enhancing carrier mobility and electrical conductivity. Dispersed reduced graphene oxide further boosts electrical conductivity and induces an energy-filtering effect, decoupling electrical conductivity and the Seebeck coefficient to achieve an impressive power factor of 37 μW cm −1 K −2 at 300 K. The high-intensity between Ag 2 Se and reduced graphene oxide interfaces enhance phonon scattering, effectively reducing thermal conductivity to below 0.9 W m −1 K −1 and enabling the high ZT value. The nylon membrane endowed the film with exceptional flexibility. A large-scale out-of-plane device with 100 pairs of thermoelectric legs, assembled from these films, delivers an ultrahigh normalized power density of >9.8 μW cm −2 K −2 , outperforming all reported Ag 2 Se-based flexible devices. When applied to the human body, the device generated sufficient power to operate a thermo-hygrometer and a wristwatch, demonstrating its practical potential for wearable electronics.