First-principles study on the origin of large thermopower in hole-doped LaRhO3 and CuRhO2

TL;DR

This study uses first-principles calculations to investigate the electronic origins of large thermopower in hole-doped LaRhO3 and CuRhO2, aligning well with experimental data and providing insights into their thermoelectric properties.

Contribution

The paper presents a detailed first-principles analysis of thermopower in doped oxides, combining band structure calculations with Boltzmann transport theory to explain experimental observations.

Findings

Seebeck coefficient remains nearly constant over a wide hole concentration in LaRhO3.

Calculated temperature dependence of thermopower in CuRhO2 matches experiments.

Identifies electronic structure features responsible for large thermopower in these materials.

Abstract

Based on first-principles calculations, we study the origin of the large thermopower in Ni-doped LaRhO3 and Mg-doped CuRhO2. We calculate the band structure and construct the maximally localized Wannier functions from which a tight binding Hamiltonian is obtained. The Seebeck coefficient is calculated within the Boltzmann's equation approach using this effective Hamiltonian. For LaRhO3, we find that the Seebeck coefficient remains nearly constant within a large hole concentration range, which is consistent with the experimental observation. For CuRhO2, the overall temperature dependence of the calculated Seebeck coefficient is in excellent agreement with the experiment. The origin of the large thermopower is discussed.