Peltier

Peltier is a surname best known in science for Jean Charles Athanase Peltier (1785–1845), a French physicist who discovered the Peltier effect in 1834. The term also refers to devices and concepts based on that effect, widely used in thermoelectric cooling and heating.

The Peltier effect describes heat transfer at the junction of two dissimilar conductors when an electric current passes through the junction. Depending on the current direction, one junction absorbs heat while the other releases heat, enabling cooling on one side and heating on the other. The amount of heat transported per unit current is characterized by the Peltier coefficient. The effect is reversible: reversing the current reverses which junction heats or cools. It is one of the two main thermoelectric effects, the other being the Seebeck effect, which converts a temperature difference into electrical voltage.

Applications rely on thermoelectric modules, sometimes called Peltier coolers, which are solid-state heat pumps with no moving parts. These devices are used to cool or heat small-scale systems, stabilize temperatures in sensors and laser diodes, cool electronic components, and power portable coolers. Their efficiency is typically lower than that of conventional refrigeration methods and depends on material properties encoded in the dimensionless figure of merit ZT, where ZT = (S^2 σ T)/κ. Common thermoelectric materials include bismuth telluride alloys and related compounds.