At what energy is Seebeck coefficient calculated?

In summary, the Seebeck coefficient can vary with energy and temperature, and is not always reported at the Fermi level and room temperature. Differences in doping concentrations can also affect the reported values.
  • #1
dyelb7
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Seebeck coefficient changes with energy and temperature. I recently thought that when Seebeck coefficients are reported, the energy corresponds to Fermi energy and temperature to room temperature, but this paper got me thinking.

Fig.4 tells us that the Seebeck coefficient at Fermi level is positive. However, Mg2Si is an n-type semiconductor with negative Seebeck coefficient (as Fig.5 confirms). I always thought Seebeck coefficient is calculated at Fermi level, but the two figures suggest otherwise. Would someone please explain where I am mistaken?
 
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  • #2
The Seebeck coefficient can indeed change with energy and temperature. It is typically reported at the Fermi level and room temperature, but this is not always the case. For example, in Fig.4 of the paper you referenced, the Seebeck coefficient is reported at a temperature of 500K. As for the discrepancy between Fig.4 and Fig.5, it is likely due to differences in the doping concentrations of the samples used in the measurements. In the case of Fig.4, the sample was heavily doped with Mg, which produces a higher Seebeck coefficient than a sample with a lighter doping concentration.
 

What is the Seebeck coefficient?

The Seebeck coefficient is a measure of the magnitude of the thermoelectric effect, which is the generation of an electric potential in a material when there is a temperature gradient present. It is a fundamental property of a material that determines its ability to convert heat energy into electricity.

How is the Seebeck coefficient calculated?

The Seebeck coefficient is typically calculated by measuring the open-circuit voltage across a temperature gradient in a material. This is done by connecting two different points on the material to a voltmeter and heating one point while keeping the other at a constant temperature. The ratio of the voltage to the temperature difference between the two points is the Seebeck coefficient.

At what energy is Seebeck coefficient calculated?

The Seebeck coefficient is typically calculated at a specific temperature, usually between room temperature and the melting point of the material. This temperature is often referred to as the reference temperature and is used to compare the Seebeck coefficients of different materials.

What factors can affect the Seebeck coefficient?

The Seebeck coefficient can be affected by a number of factors, including the temperature, the composition and microstructure of the material, and the presence of impurities or defects. Additionally, the Seebeck coefficient can vary depending on the direction of the temperature gradient and the direction of the electric field.

Why is the Seebeck coefficient important?

The Seebeck coefficient is an important property in the field of thermoelectric materials and devices. It is used to characterize a material's ability to convert heat energy into electricity, which has potential applications in energy harvesting and waste heat recovery. Additionally, the Seebeck coefficient can provide insight into the electronic and thermal transport properties of a material.

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