Electronic Structure and Thermoelectric Transport Properties of Iridium-Doped TiGePt Half-Heusler Alloys: A DFT and BoltzTraP Study
Year: 2026
Type: article
Abstract: ABSTRACT This work examines the electronic structure and thermoelectric transport characteristics of the half-Heusler alloy TiGePt with different amounts of Iridium (Ir) doping, utilising Density Functional Theory (DFT). The pure TiGePt alloy is classified as a semiconductor with an estimated band gap of 0.899 eV; however, the incorporation of Iridium, which has an extra valence electron, results in a transition to a metallic state. An examination of the band structure and density of states indicates that Ir doping efficiently elevates the Fermi level into the conduction band, leading to a substantial enhancement in the density of states at the Fermi level. Transport simulations conducted using BoltzTraP indicate that the pure alloy has a high Seebeck coefficient of around ±1.5 mV/K, however it experiences minimal electrical conductivity within the band gap. In contrast, the 25% Ir-doped system, examined using thermoelectric transport property plots, exhibits stabilised plateaus in electrical and thermal conductivity. The results indicate that Ir doping is an effective method for adjusting the chemical potential of TiGePt, converting it from a fundamental semiconductor into a high-conductivity alloy tailored for thermoelectric applications. Key words: Thermoelectric, electronic structure, Seebeck coefficient, electrical conductivity, thermal conductivity.
Institution: Niger Delta University
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W7160243460