High-Pressure Routes in the Thermoelectricity or How One Can Improve a Performance of Thermoelectrics

High pressure has a strong impact oil materials. In regards to thermoelectrics, pressure is able to significantly improve their thermoelectric (TE) performance (i.e., power factor and figure of merit), and for this reason, pressure is a powerful tool for energy conversion technologies. This paper reviews studies on thermoelectric properties of relevant materials (PbTe, PbSe, Bi2Te3, Sb2Te3, and others) under pressure. It is figured out that enhanced thermoelectric properties of lead telluride and bismuth telluride appear beyond a range of energy gaps proposed for a "conventional" thermoelectricity in narrow-gap semiconductors. Ail example given for SmTe hints that pressure effects oil the thermoelectric performance may be tremendous. This review also attends studies on high-pressure thermoelectric properties in the presence of a nonzero magnetic field. Influence of magnetic-field-related effects, such as magnetoresistance, magnetothermopower (Nernst-Ettingshausen effects), and Maggi-Reghi-Leduc effect is analyzed on examples of PbTe, PbSe, and Te. Problems related to both in situ measurements of transport properties under pressure, and practical realization of high-pressure (magneto-)thermoelectric devices are discussed. In summary, this review reports the-state-of-the-art of pressure influence on thermoelectric materials and shows alternative poorly explored routes in the thermoelectricity.