High efficiency thermoelectric (TE) materials still require high thermopower for energy harvesting applications. A simple elemental metallic semiconductor, tellurium (Te), has been considered critical to realize highly efficient TE conversion due to having a large effective band valley degeneracy. This paper demonstrates a novel approach to directly probe the out-of-plane Seebeck coefficient for one-dimensional Te quantum wires (QWs) formed locally in the aluminum oxide layer by well-controlled electrical breakdown at 300 K. Surprisingly, the out-of-plane Seebeck coefficient for these Te QWs ≈ 0.8 mV/K at 300 K. This thermopower enhancement for Te QWs is due to Te intrinsic nested band structure and enhanced energy filtering at Te/AO interfaces. Theoretical calculations support the enhanced high Seebeck coefficient for elemental Te QWs in the oxide layer. The local-probed observation and detecting methodology used here offers a novel route to designing enhanced thermoelectric materials and devices in the future.
Bibliographical noteFunding Information:
This study was supported by the National Research Foundation of Korea (NRF), funded by the Korean Government (2019R1A2C1003366, 2020R1A2C1004979, and 2020R1A5A1016518). The authors thank Dr. T. Kikkawa for valuable discussions and technical assistance.
© 2021 American Chemical Society.
ASJC Scopus subject areas
- General Materials Science
- Physical and Theoretical Chemistry