Thin films of topological nodal line semimetals as a candidate for efficient thermoelectric converters

Thermoelectric materials have attracted significant interest owing to their wide range of applications, such as power generators and refrigerators. Along with the evaluation of Bi2Te3 and its alloys, the search for materials that show good thermoelectric performance has risen considerably. The efficiency of thermoelectric conversion is quantified by the figure of merit, ZT, and ZT greater than unity has been considered as a target. For a large ZT, acquiring a large Seebeck coefficient and a reduction of phonon thermal conductivity are significant given its definition. In this work, we propose that a thin film of topological nodal line semimetals can be a new and promising thermoelectric material. We also discuss the correlation effect and spin current induced by the temperature gradient. The obtained results give various insights into the quest for the best thermoelectric materials.