MXene-assisted Bi2Te3 pellet-based thermoelectric generator

Abstract

A thermoelectric generator (TEG) was fabricated using n-type and p-type Bi2Te3 pellets mounted on a polyamide/Kapton substrate through low-temperature soldering. Ti3C2Tx MXene was synthesized via selective etching and delamination of the corresponding MAX phase, followed by structural and morphological characterization to confirm the successful formation of layered conductive nanosheets. A physically attached Ti3C2Tx MXene backing layer was introduced to investigate its influence on thermoelectric output performance under externally applied thermal gradients. The fabricated devices exhibited an approximately linear increase in output voltage with increasing temperature difference (ΔT). At a ΔT of 76 °C, the original TEG generated an open-circuit voltage of 19.6 mV, whereas the MXene-assisted configuration achieved 22.3 mV, corresponding to an enhancement of approximately 13.8%. Load-dependent measurements further revealed an increase in maximum output power from 94.08 nW to 124.32 nW under matched load resistance conditions, representing an improvement of approximately 32%. The MXene-assisted TEG also exhibited an increased normalized areal power density compared with the pristine device, further demonstrating the beneficial effect of the MXene interfacial layer. The enhanced thermoelectric performance is attributed to the high electrical conductivity and layered morphology of Ti3C2Tx MXene, which contribute to improved thermal distribution and interfacial heat management within the TEG architecture. These findings demonstrate the potential of MXene-assisted thermoelectric systems for energy harvesting applications.