Flexible PEDOT:PSS thermoelectrics reinforced by HESO8@Sb2Te3 core–shell networks

Flexible polymer thermoelectrics were realized by dispersing core–shell HESO8@Sb 2 Te 3 particulates within a PEG-assisted PEDOT:PSS matrix. Leveraging the high-entropy spinel (HESO8) core for mass-fluctuation/point-defect phonon scattering, the composites suppress thermal conductivity (κ), while the Sb 2 Te 3 shell contributes to interfacial carrier-transport modulation and percolation-aided charge transport across the conducting network. Solution processing yielded self-supporting films with filler contents of 5–20 wt%. Among them, the 10 wt% specimen provided the most balanced response throughout 300–475 K, exhibiting a monotonic rise in Seebeck coefficient with temperature and a peak conductivity near 425 K. At ∼425 K, the film delivered ZT ≈ 0.50 with κ ≈ 0.21 W m −1 K −1 and PF ≈ 2.4 × 10 2 μW m −1 K −2 . The performance stems from the dual action of (i) κ reduction via the spinel core and abundant polymer–filler interfaces and (ii) PF enhancement associated with Sb 2 Te 3 -mediated interfacial carrier transport together with PEG-induced PEDOT-rich pathways. This spinel–telluride core–shell strategy offers a scalable route to low-κ, high-PF polymer thermoelectrics operating from room to mid-temperature.