Interface Engineering in Polymer Thermoelectric Composites: Harnessing Energy-Filtering Effects to Overcome the Seebeck-Conductivity Trade-off

Abstract

Thermoelectric (TE) materials enable direct heat-to-electricity conversion, offering sustainable energy solutions. While significant progress has been made in organic and composite TE systems, the strategic enhancement of Seebeck coefficient through energy filtering (EF)critical for overcoming Seebeck-conductivity trade-off -lacks comprehensive review. This article provides a systematic review of EF engineering in polymer-based TE composites. We first outline the fundamental principles of thermoelectricity and EF effects, emphasizing their role in decoupling TE parameters through selective carrier scattering at engineered interfaces.The review then analyzes four key material categories: (1) Ionic organic films, where Soret effect-driven ion accumulation creates interfacial energy barriers; (2) Organic-inorganic composites featuring quantum dots, nanowires, and 2D materials that optimize energydependent carrier transport; (3) MXene-based hybrids leveraging tunable work functions for interfacial band alignment; and (4) Aerogel composites utilizing 3D porous networks for simultaneous phonon scattering and charge filtering. Finally, we provide an outlook on the prospects and challenges of polymer and composite TE materials via EF. This review bridges fundamental charge transport physics with practical material design, offering a guideline for next-generation polymer-based TE materials optimized through EF effects.