Enhanced Thermoelectric Power and Electronic Correlations in RuSe$_2$

TL;DR

This study investigates how iridium doping affects the electronic structure and thermoelectric properties of RuSe₂, revealing enhanced thermoelectric performance and the role of electronic correlations, with a focus on transport behavior and phase crossover.

Contribution

It provides new insights into the impact of Ir substitution on RuSe₂'s electronic and thermoelectric properties, highlighting the importance of electronic correlations in thermoelectric enhancement.

Findings

Ir doping suppresses resistivity and Seebeck coefficient.

Ru₀.₈Ir₀.₂Se₂ exhibits a semiconductor-metal crossover at 30 K.

Magnetic field restores semiconducting behavior.

Abstract

We report the electronic structure, electric and thermal transport properties of Ru$_{1-x}$Ir$_{x}$Se$_2$ ($x \leq 0.2$). RuSe$_2$ is a semiconductor that crystallizes in a cubic pyrite unit cell. The Seebeck coefficient of RuSe$_2$ exceeds -200 $\mu$V/K around 730 K. Ir substitution results in the suppression of the resistivity and the Seebeck coefficient, suggesting the removal of the peaks in density of states near the Fermi level. Ru$_{0.8}$Ir$_{0.2}$Se$_{2}$ shows a semiconductor-metal crossover at about 30 K. The magnetic field restores the semiconducting behavior. Our results indicate the importance of the electronic correlations in enhanced thermoelectricity of RuSb$_{2}$.