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Review
. 2021 Apr 13;22(1):280-284.
doi: 10.1080/14686996.2021.1903816.

Improving the thermoelectric figure of merit

H Julian Goldsmid  1
Affiliations
Review

Improving the thermoelectric figure of merit

H Julian Goldsmid. Sci Technol Adv Mater. .

Abstract

The efficiency of a thermoelectric generator and the coefficient of performance (COP) of a thermoelectric heat pump are related to the hot and cold junction temperatures and a quantity known as the figure of merit, zT. During the second half of the twentieth century the figure of merit has gradually improved. This has come about through the selection of semiconducting materials with improved electronic properties and a small lattice thermal conductivity. Further advancements have been achieved by enhancing the scattering of phonons. There is also the possibility of improving the so-called power factor, that is the part of the figure of merit that contains the Seebeck coefficient and the electrical conductivity. However, it appears that it will be increasingly difficult to make further advances because of the manner in which these quantities vary with the Fermi energy. It is shown that this may set a practical limit on zT. Nevertheless, it may be possible to reach an efficiency or COP of about 40% of that of an ideal thermodynamic machine.

Keywords: 206 Energy conversion / transport / storage / recovery; 210 Thermoelectronics / Thermal transport / insulators; 50 Energy Materials; Thermoelectric energy convertor; figure of merit; thermoelectric materials.

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Conflict of interest statement

No potential conflict of interest was reported by the author.

Figures

None
Graphical abstract
Figure 1.
Figure 1.
Plot of zT against the materials parameter β
See this image and copyright information in PMC

References

    1. Ioffe AF. Semiconductor thermoelements and thermoelectric cooling. London (UK): Infosearch; 1957.
    1. Goldsmid HJ, Douglas RW.. The use of semiconductors in thermoelectric refrigeration. Br J Appl Phys. 1954;5:386.
    1. Ioffe AV, Ioffe AF. Some relationships about the value of the thermal conductivity of semiconductors. Dokl Akad Nauk SSSR. 1954;97:821.
    1. Keyes RW. High-temperature thermal conductivity of insulating crystals: relationship to the melting point. Phys Rev. 1959;115:564–567.
    1. Slack GA. CRC handbook of thermoelectrics. Rowe DM, editors. Boca Raton (FL): CRC Press; 1994. p. 407.