Synergistic Carrier and Interface Engineering Enables High-Power Flexible Sb2Te3 Thermoelectric Devices

Abstract

Flexible thermoelectric devices show great potential for wearable electronics and low-grade heat recovery, yet they still face the challenge of simultaneously achieving high thermoelectric performance and high device-level output power due to the coupled limitations of carrier transport and interfacial energy losses. In this work, Bi doping is employed to regulate the carrier concentration and mobility of Sb2Te3 films, leading to a significantly enhanced power factor and a maximum room-temperature thermoelectric figure of merit of 0.61. To further reduce interfacial losses, electrode materials are systematically screened based on work-function matching, contact resistance, and thermal stability. Among the investigated electrodes, Ni exhibits the lowest contact resistance with Sb2Te3 films and maintains a stable interface after thermal treatment, effectively suppressing contact degradation. Benefiting from the synergistic optimization of the thermoelectric film and electrode interface, the optimized flexible thermoelectric device delivers a maximum output power of 18.3 μW and a power density of 10.4 mW cm–2 under a temperature difference of 60 K. This work establishes an effective pathway for bridging high-ZT thermoelectric films and high-power flexible devices through synergistic carrier and interface engineering, providing a promising strategy for wearable energy-harvesting applications.