Core–shell nanowire architectures enable high-performance flexible thermoelectrics via energy filtering and phonon scattering

Achieving high performance in flexible thermoelectric materials remains challenging due to the intrinsically conflicting requirements among electrical conductivity, Seebeck coefficient, and thermal conductivity in conventional brittle inorganic thermoelectric materials. Here, we present a hierarchical triple-layer core–shell nanowire architecture based on Ag nanoparticle-decorated Ag 2 Te@Ag@PEDOT:PSS, designed to decouple electron and phonon transport via energy filtering and enhanced phonon scattering. The architecture integrates a conductive Ag 2 Te nanowire core, metallic Ag nanoparticle islands to facilitate carrier transport, and an external PEDOT:PSS shell that serves as an energy filter to suppress low-energy electrons. The hierarchical design achieves an ultralow room-temperature thermal conductivity of 0.407 W m -1 K -1 and a high power factor of 294.53 μW m -1 K −2 , resulting in a record-high ZT value of 0.22 at 300 K, outperforming comparable materials. The fabricated flexible thermoelectric generator (FTEG), when worn on the human body, produces an open-circuit voltage of 1.29 mV, under a temperature difference of 5.6 K between the skin and the environment confirming that the device itself cannot directly drive LEDs. After amplification by a low-power amplification circuit module, it is capable of powering four LEDs, demonstrating its promising potential for self-powered wearable electronics.