Improvement in the thermoelectric properties of pressure-tuned β-K2Bi8Se13

Abstract

The thermoelectric power, electrical conductivity, crystal structure, and Raman active phonon modes of the semiconductor β-K2Bi8Se13 have been studied under pressure. There is a large increase in the electrical conductivity in the pressure range 0–1 GPa and a sharp maximum in the magnitude of the thermoelectric power at ∼1.4 GPa. X-ray diffraction studies revealed no structural change upon compression. The Raman active vibrational modes did not shift substantially with pressure, suggesting that the pressure induced changes in the phonon thermal conductivity may not be large. The thermoelectric figure of merit, ZT, likely increases by a factor of at least 2 from its ambient pressure value of 0.23. This is the first n-doped material for which we have observed a peak in the thermoelectric power suggestive of an electronic topological transition upon compression.

High‐pressure thermopower of PbTe‐based compounds

“…To take into account the error introduced by the anvils, the sample was replaced by a piece of Pb with the value of thermopower close to zero (S = -1.27 µV/K) at room temperature [10]. Similar, but much more complicated techniques of thermoelectric measurements at high pressure P ≤ 12 GPa are developed now using natural diamond anvils [11].…”

Electrical Transport and Thermoelectric Properties of PbTe Prepared by HPHT

“…11,12) Meng et al reported that the thermoelectric power and the electrical conduction for several materials were largely enhanced under high pressure. 13) Unfortunately, these properties could not be kept at room temperature after the pressure has been released. With the temperature tuning, these improved properties by pressure might be quenched at room temperature.…”

Cascade of Magnetic-Field-Induced Lifshitz Transitions in the Ferromagnetic Kondo Lattice Material YbNi4P2

“…solid solutions [38,40], semiconductors [38,41], and high-temperature superconductors [42,43]. However, these materials need to be tuned to the LT by external pressure or doping.…”