Sie befinden Sich nicht im Netzwerk der Universität Paderborn. Der Zugriff auf elektronische Ressourcen ist gegebenenfalls nur via VPN oder Shibboleth (DFN-AAI) möglich. mehr Informationen...
Ultrahigh zT from strong electron–phonon interactions and a low-dimensional Fermi surface
Ist Teil von
Energy & environmental science, 2024-03, Vol.17 (5), p.1904-1915
Ort / Verlag
Cambridge: Royal Society of Chemistry
Erscheinungsjahr
2024
Quelle
Alma/SFX Local Collection
Beschreibungen/Notizen
The outstanding thermoelectric performance of GeTe has attracted significant attention in the research community in recent years. However, many of the underlying physical mechanisms that contribute to GeTe's exceptionally high figure of merit (
zT
) remain not fully understood. In this study, an Sb–Bi codoped GeTe single crystal (Ge
0.86
Sb
0.08
Bi
0.06
)Te with an ultrahigh
zT
of 2.7 at 700 K and a record high device
zT
of 1.41 in the temperature range of 300–773 K was synthesized and investigated. The ultrahigh
zT
is attributed to the extremely low lattice thermal conductivity induced by strong electron–phonon (EP) interactions as revealed by the experimentally observed Kohn anomaly, through inelastic neutron scattering (INS) measurements. First-principles calculations further demonstrate that the remarkable EP interaction arises from the Fermi surface nesting featured in a one-dimensional (double-walled) topology. Our finding unravels the ultrahigh-
zT
mechanism in GeTe-based materials, serving as an inspiring guide toward high thermoelectric performance.