Thermoelectric performance of PbSnTeSe high-entropy alloys

Abstract

In our study, we designed the PbSnTeSe high-entropy alloy (HEA) and investigated its microstructure and thermoelectric properties. It was found that the PbSnTeSe HEA has a simple face-centered cubic structure and possesses quite low lattice thermal conductivity at low temperatures, which could be ascribed to the strong phonon scattering due to its severe lattice-distortion. Minor additions of La not only enhanced both Seebeck coefficient and electrical conductivity at high temperatures, but also suppressed the bipolar effect to some degree. Our results indicate that the HEA concept could be applied for developing promising thermoelectric materials, which merits further investigation. IMPACT STATEMENTThe high-entropy alloy-design concept was employed to develop novel thermoelectric materials. Our findings indicate that this strategy effectively reduced the lattice thermal conductivity, which have important implications for the field. ARTICLE HISTORY

(Hf0.2Zr0.2Ta0.2Nb0.2Ti0.2)C high‐entropy ceramics with low thermal conductivity

“…The low thermal conductivity of (Hf 0.2 Zr 0.2 Ta 0.2 Nb 0.2 Ti 0.2 )C may be mainly attributed to its distorted anion sublattice, at which the phonons are scattered more significantly. The low thermal conductivity due to lattice distortion has also been observed in some other HEAs, such as PbSnTeSe and BiSbTe 1.5 Se 1.5 . However, there is a significant difference in HECs and HEAs.…”

Science and technology in high-entropy alloys

“…HEAs have a high degree of chaos in its atomic arrangement, resulting in the enhanced scattering of phonon and effectively reducing its lattice thermal conductivity. The PbSnTeSe [104] HEA was discovered, possessing a quite low lattice thermal conductivity of 0.6 W m −1 K −1 at room temperature. By minor additions of La to substitute Pb, the thermoelectric performance of PbSnTeSe could be further enhanced, as indicated in Fig.…”

Single-Phase Concentrated Solid-Solution Alloys: Bridging Intrinsic Transport Properties and Irradiation Resistance

“…Electrical and thermal conductivities of HEAs are further related to their thermoelectric properties, with the figure of merit (ZT) calculated from the Seebeck coefficient (S), electrical resistivity (ρ), and total thermal conductivity (κ) from the equation ZT = S 2 ρ −1 κ −1 T. For example, low lattice thermal conductivities above room temperature in BiSbTe 1.5 Se 1.5 (Fan et al, 2016) and PbSnTeSe (Fan et al, 2017), ∼0.47 and 0.6 Wm −1 K −1 , respectively, have been reported to contribute to their relatively high ZT values. Both studies have ascribed such low κ g values to the severe lattice distortion, while further evidences may be necessary to validate this proposed mechanism.…”