Direction dependent thermoelectric properties of layered compound In2Te5 single crystal

TL;DR

This study investigates the anisotropic thermoelectric properties of In2Te5 single crystals, revealing significant directional differences in thermal conductivity and Seebeck coefficient, leading to a higher figure of merit along the c-axis.

Contribution

It provides detailed measurements of directional thermoelectric properties of In2Te5 single crystals, highlighting the anisotropy and its impact on thermoelectric efficiency.

Findings

Thermal conductivity along the c-axis is half of that perpendicular.

Seebeck coefficient is higher along the c-axis.

Figure of merit ZT is four times larger along the c-axis.

Abstract

We analyze the anisotropic electrical and thermal transport measurements in single crystals of In2Te5 belonging to monoclinic space group C12 c1 with the temperature gradient applied parallel and perpendicular to the crystallographic c-axis of the crystals. The thermal conductivity along the c-axis thermal conductivity parallel was found to smaller by a factor of 2 compared to the thermal conductivity along the direction perpendicular to the c-axis over the entire temperature range. In contrast, the Seebeck coefficient along the c-axis parallel was found to be higher than its value along the direction perpendicular to the c-axis. At room temperature, the figure of merit ZT parallel is found to be 4 times larger as compared to the figure of merit ZT perpendicular.