Review on thermoelectric properties of transition metal dichalcogenides

TL;DR

This review summarizes experimental research on the thermoelectric properties of transition metal dichalcogenides (TMDs), highlighting their potential advantages and the need for further investigation to assess their viability in thermoelectric applications.

Contribution

The paper compiles and analyzes existing experimental data on TMDs' thermoelectric properties and simulates a TMD-based thermoelectric device for practical use.

Findings

TMDs exhibit promising thermoelectric properties with tunable band structures.

Simulation shows potential for TMDs in micron-sized cryocoolers and power generators.

Experimental data indicates diverse thermoelectric performance depending on composition and doping.

Abstract

Transition metal dichalcogenides (TMDs) are considered an advantageous alternative to their celebrated two-dimensional (2D) van der Waals akin compound, graphene, for a number of applications, especially those requiring a gapped and possibly tunable band structure. Thermoelectricity is one of the application fields where TMDs could indeed outperform graphene, thanks to their lower thermal conductivity, large effective masses, valley degeneracy, varied and tunable transport properties, as well as sensitivity of their band structures and phonon spectra to confinement. Yet, despite promising theoretical predictions, thermoelectric properties of TMDs have not been extensively investigated so far and a clear assessment of TMDs as viable thermoelectric materials, based on experimental results, is still missing. In this paper, we review the experimental findings of literature on thermoelectric properties of TMDs, to sort out the countless combinations of chemical compositions, doping, off-stoichiometry and sample forms which could potentially result in optimized and possibly competitive thermoelectric properties. Based on the experimental data of literature, we simulate the performance of an all-TMD thermoelectric device for practical application as a micron sized cryocooler or power generator.