Giant enhancement of cryogenic thermopower by polar structural instability in the pressurized semimetal MoTe2

Abstract

We found that a high mobility semimetal 1T'-MoTe2 shows a significant pressure-dependent change in the cryogenic thermopower in the vicinity of the critical pressure, where the polar structural transition disappears. With the application of a high pressure of 0.75 GPa, while the resistivity becomes as low as 10 μΩcm, thermopower reached the maximum value of 60 μVK-1 at 25 K, leading to a giant thermoelectric power factor of 300 μWK-2cm-1. Based on semiquantitative analyses, the origin of this behavior is discussed in terms of inelastic electron-phonon scattering enhanced by the softening of zone center phonon modes associated with the polar structural instability.

13 pages, 4 figures Physical review B (accepted)

References in corpus (6)

• The structures and thermoelectric properties of the infinitely adaptive series (Bi2)m(Bi2Te3)n
• Large Seebeck Effect by Charge-Mobility Engineering
• Activation of new Raman modes by inversion symmetry breaking in type II Weyl semimetal candidate T'-MoTe2
• Critical enhancement of thermopower in a chemically tuned polar semimetal MoTe${}_2$
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• Electronic thermoelectric power factor and metal-insulator transition in FeSb2

Cited by in corpus (1)

• Superconducting pairing symmetry in MoTe${}_2$