Seebeck coefficient

Thermoelectric effect
Principles Thermoelectric effect Seebeck effect Peltier effect Thomson effect Seebeck coefficient Ettingshausen effect Nernst effect
Applications Thermoelectric materials Thermocouple Thermopile Thermoelectric cooling Thermoelectric generator Radioisotope thermoelectric generator Automotive thermoelectric generator
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The Seebeck coefficient (also known as thermopower,^[1] thermoelectric power, and thermoelectric sensitivity) of a material is a measure of the magnitude of an induced thermoelectric voltage in response to a temperature difference across that material, as induced by the Seebeck effect.^[2] The SI unit of the Seebeck coefficient is volts per kelvin (V/K),^[2] although it is more often given in microvolts per kelvin (μV/K).

The use of materials with a high Seebeck coefficient^[3] is one of many important factors for the efficient behaviour of thermoelectric generators and thermoelectric coolers. More information about high-performance thermoelectric materials can be found in the Thermoelectric materials article. In thermocouples the Seebeck effect is used to measure temperatures, and for accuracy it is desirable to use materials with a Seebeck coefficient that is stable over time.

Physically, the magnitude and sign of the Seebeck coefficient can be approximately understood as being given by the entropy per unit charge carried by electrical currents in the material. It may be positive or negative. In conductors that can be understood in terms of independently moving, nearly-free charge carriers, the Seebeck coefficient is negative for negatively charged carriers (such as electrons), and positive for positively charged carriers (such as electron holes).