Thermoelectric coolers (also known as thermoelectric device or thermoelectric module) are semiconductor modules which use the Peltier Effect to create a heat flux between the junctions of two different types of materials. Named after French physicist Athanase Peltier, the Effect shows that a temperature differential is created when DC current is applied across two dissimilar materials. (It is one of the three thermoelectric effects; the others are the Seebeck Effect and Thomson Effect)
A typical thermoelectric cooler is manufactured using two thin ceramic wafers with a series of N and P doped bismuth-telluride semiconductor material sandwiched between them. The ceramic material adds rigidity and the necessary electrical insulation. The N type material has excess electrons, while the P type material has a deficit of electrons. One N and one P make up a couple, as shown in Figure 1.
When a DC current is applied to the circuit, the thermoelectric device can work as a cooler or heater depending on the currents direction. A thermoelectric cooler (TEC), or solid state heat pump transfers heat from one side of the device to the other side against the temperature gradient. Many products use thermoelectric coolers, including small refrigeration systems, CCD cameras, laser diodes and portable picnic coolers. They are also used in the thermal management of microprocessors, memory modules and other electronic devices.
ATS’s white paper covers much more on this topic, and you can get your own copy for free, by clicking to, “Using Thermoelectric Coolers in Electronics Cooling“.