Large Thermoelectric Power Factor in Whisker Crystals of Solid Solutions of the One-Dimensional Tellurides Ta4SiTe4 and Nb4SiTe4

TL;DR

This paper reports the synthesis and characterization of whisker crystals of Ta4SiTe4-Nb4SiTe4 solid solutions, demonstrating high thermoelectric power factors and promising low-temperature thermoelectric performance.

Contribution

It introduces new solid solutions of one-dimensional tellurides with enhanced thermoelectric properties and explores doping effects to optimize performance.

Findings

Power factors exceeding 40 μW cm⁻¹ K⁻² in doped samples

High thermoelectric performance below room temperature

Solid solutions show promising thermoelectric potential

Abstract

One-dimensional tellurides Ta4SiTe4 and Nb4SiTe4 were found to show high thermoelectric performance below room temperature. This study reported the synthesis and thermoelectric properties of whisker crystals of Ta4SiTe4-Nb4SiTe4 solid solutions and Mo- or Ti-doped (Ta0.5Nb0.5)4SiTe4. Thermoelectric power of the solid solutions systematically increased with increasing Ta content, while their electrical resistivity was unexpectedly small. Mo- and Ti-doped (Ta0.5Nb0.5)4SiTe4 showed n- and p-type thermoelectric properties with large power factors exceeding 40 microW cm-1 K-2, respectively. The fact that not only Ta4SiTe4 and Nb4SiTe4 but also their solid solutions showed high performance indicated that this system is a promising candidate for thermoelectric applications at low temperatures.