Enhanced thermoelectric performance of MXene/GeTe through a facile freeze-drying method

As a great promising lead-free mid-temperature thermoelectric material, Germanium telluride (GeTe) has attracted recently a great deal of attention. However, the high carrier concentration caused by Ge vacancies and thermal conductivity have been a bottleneck of its widespread use in thermoelectrics. The in-corporation of nano-second phase has been considered a promising method to address the above issues. However, how to choose a suitable nano-second phase and achieve uniform dispersion in the matrix is still difficult. In this work, uniform dispersion of 2D material MXene in the GeTe was realized by a simple freeze-drying method, successfully tuning the electron and thermal transport properties of GeTe-based alloys synchronously. The results revealed that the carrier concentration of GeTe-based composite gradually de-creased from-1021 to-1020 cm-3 with the participation of MXene. The lowest thermal conductivity can reach 2.19 W m-1 K-1 for GeTe composites with 1.5 vol% MXene at 700 K, which is-25.8% lower than that of pristine GeTe. Benefiting from the reduced carrier concentration and thermal conductivity, a maximum ZT value of 1.13 at 700 K is achieved for the composites with 1.5 vol% MXene, showing a 20.2% improvement compared with that of pristine GeTe (-0.94). These results point out the potential value of MXene in en-hancing the performance of GeTe-based thermoelectric materials.(c) 2023 Elsevier B.V. All rights reserved.

Automated summary

Germanium telluride (GeTe) has recently gained a lot of attention as a promising lead-free mid-temperature thermoelectric material. However, high carrier concentration and thermal conductivity have hindered its widespread use. This study successfully achieved the uniform dispersion of 2D material MXene in GeTe, leading to improved electron and thermal transport properties. The incorporation of MXene resulted in decreased carrier concentration and thermal conductivity, leading to significant enhancement in the performance of GeTe-based thermoelectric materials.