ABSTRACT
Thermoelectricity (TE) is the solid-state conversion of a temperature gradient (ΔT) into an electrical voltage (V), or vice versa. It comprises three distinct phenomena or effects: the Seebeck, Peltier, and Thomson effects (Figures 32.1 through 32.3). The Seebeck effect is the observation of a temperature difference (ΔT) that is converted into voltage (V) and was first discovered by Thomas Seebeck in 1821. He observed that applying a temperature difference to a closed loop containing a junction of two dissimilar metals resulted in the deflection of a compass. Complementary to the Seebeck effect is the Peltier effect, where the flow of a current across a junction results in the generation or removal of heat. Finally, the Thomson effect is the observation of a temperature gradient across a current-carrying conductor that results in the heating or cooling of the conductor. The latter arises because the Seebeck effect is temperature dependent. Hence, in a thermoelectric material subjected to a temperature gradient, a gradient in the Seebeck coefficient also arises. This, in turn, gives rise to a continuous version of the Peltier effect [1]. The Seebeck effect. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315374185/8faf731e-af5e-49b4-bdb4-ffad9288d681/content/fig32_1.tif"/> The Peltier effect. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315374185/8faf731e-af5e-49b4-bdb4-ffad9288d681/content/fig32_2.tif"/> The Thomson effect. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315374185/8faf731e-af5e-49b4-bdb4-ffad9288d681/content/fig32_3.tif"/>
