Establishing the carrier scattering phase diagram for ZrNiSn-based half-Heusler thermoelectric materials

Abstract

Chemical doping is one of the most important strategies for tuning electrical properties of semiconductors, particularly thermoelectric materials. Generally, the main role of chemical doping lies in optimizing the carrier concentration, but there can potentially be other important effects. Here, we show that chemical doping plays multiple roles for both electron and phonon transport properties in half-Heusler thermoelectric materials. With ZrNiSn-based half-Heusler materials as an example, we use high-quality single and polycrystalline crystals, various probes, including electrical transport measurements, inelastic neutron scattering measurement, and first-principles calculations, to investigate the underlying electron-phonon interaction. We find that chemical doping brings strong screening effects to ionized impurities, grain boundary, and polar optical phonon scattering, but has negligible influence on lattice thermal conductivity. Furthermore, it is possible to establish a carrier scattering phase diagram, which can be used to select reasonable strategies for optimization of the thermoelectric performance.

arXiv comment21 pages, 5 figures

References in corpus (9)

• Thermal Properties of Isotopically Engineered Graphene
• Giant Anharmonic Phonon Scattering in PbTe
• Covalent bonding and the nature of band gaps in some half-Heusler compounds
• Liquid-like thermal conduction in a crystalline solid
• Glass-like phonon scattering from a spontaneous nanostructure in AgSbTe2
• Breakdown of optical phonons' splitting in two-dimensional materials
• Phonon self-energy and origin of anomalous neutron scattering spectra in SnTe and PbTe thermoelectrics
• Microscopic mechanism of low thermal conductivity in lead-telluride
• Characterization of rattling in relation to thermal conductivity: ordered half-Heusler semiconductors

Cited by in corpus (10)

• Ultrasensitive barocaloric material for room-temperature solid-state refrigeration
• ElecTra Code: Full-Band Electronic Transport Properties of Materials
• Electron-phonon interaction and longitudinal-transverse phonon splitting in doped semiconductors
• Electron-phonon interaction and phonons in 2d doped semiconductors
• First-principles analysis of intravalley and intervalley electron-phonon scattering in thermoelectric materials
• Pisarenko's Formula for the Thermopower
• The stable behavior of low thermal conductivity in 1T-sandwich structure with different components
• Neutron scattering studies of complex lattice dynamics in energy materials
• On electrical transport and thermoelectric performance in half-Heusler phase ScNiSb
• Dopant-modulated lattice softening drives drastic thermal conductivity reduction in β-FeSi2 thermoelectrics