Giant longitudinal and transverse magnetothermoelectric effects in a van del Waals semimetal TaCo 2 Te 2

• Published in: Energy & environmental science 2024-10, Vol.17 (19), p.7129-7134
• Main Authors: Gui, Zhigang, Yang, Ye, Wen, Xikai, Zhang, Yuqing, Li, Yikang, Li, Yanjun, Liu, Qingyuan, Wang, Mingjie, Ying, Jianjun, Chen, Xianhui
• Format: Article
• Language: English
• ISSN: 1754-5692; 1754-5706
• DOI: 10.1039/D4EE01857E

Nowadays, thermoelectric (TE) cooling technologies are hindered by the paucity of efficient low-temperature TE materials, which are critical to both cryogenic research and practical applications. Herein, we present the discovery of a flexible van der Waals semimetal TaCo 2 Te 2 , which exhibits exceptional TE performance in both the longitudinal and transverse directions. The transverse power factor reaches an unsaturated ultrahigh value, 25 680 μW m −1 K −2 , under 13.5 T at 20 K, surpassing the performance of most transverse TE materials. Two longitudinal power factor peaks are observed, dominated by different carriers, with the highest recorded values of 11 600 μW m −1 K −2 at 20 K in the electron-dominant region and 2200 μW m −1 K −2 at 120 K in the hole-dominant region without magnetic field. This outstanding TE performance can be attributed to high mobility and the phonon drag effect, underscoring TaCo 2 Te 2 as a promising material candidate for low-temperature solid-state cooling applications within TE technology.