What is Thermoelectric Cooling?

French watchmaker, Jean Charles Athanase Peltier, discovered thermoelectric cooling effect,also known as Peltier cooling effect, in 1834. Peltier discovered that the passage of a current through a junction formed by two dissimilar conductors caused a temperature change. However, Peltier failed to understand this physics phenomenon, and his explanation was that the weak current doesn’t obey Ohm’s law. Peltier effect was made clear in 1838 by Emil Lenz, a member of the St. Petersburg Academy. Lenz demonstrated that water could be frozen when placed on a bismuth-antimony junction by passage of an electric current through the junction. He also observed that if the current was reversed the ice could be melted.

In 1909 and 1911 another scientist Altenkirch derived the basic theory of thermoelectrics. His work pointed out that thermoelectric cooling materials needed to have high Seebeck coefficients,good electrical conductivity to minimize Joule heating, and low thermal conductivity to reduce heat transfer from junctions to junctions. Shortly after the development of practical semiconductors in 1950’s, bismuth telluride began to be the primary material used in the thermoelectric cooling.