SA and SB are the Seebeck-coefficients, which are depending on material and temperature. T1 and T2 represent the different temperatures. If the temperature difference is very small and the Seebeck-coefficients stay constant, U=(SB-SA)*(T2-T1) will be assumed. …
Is the Seebeck coefficient constant?
What is the coefficient of Seebeck effect?
The Seebeck coefficient (also known as thermopower, 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.
Does the Seebeck coefficient vary with temperature?
We find that the Seebeck coefficient has an ambipolar behavior, namely, at relatively low-temperature range, negative S nonmonotonically changes with increasing T, and at very high T, the sign of S changes, shown in Figure 4a.
What is Seebeck coefficient formula?
thermoelectric generators generated voltage (V) is the Seebeck voltage and is related to the difference in temperature (ΔT) between the heated junction and the open junction by a proportionality factor (α) called the Seebeck coefficient, or V = αΔT.
What does a high Seebeck coefficient mean?
The figure of merit is proportional to the ratio of electric and thermal conductivity and proportional to the square of the Seebeck coefficient S. So higher S, so higher Z. Therefore, if you want to reach a high conversion of thermal into electrical energy, a high Seebeck coefficient is important.
Why does Seebeck coefficient increase with temperature?
assuming the semiconductor is n type, the temperature rise lower the Fermi Level. As consequence the seebeck increases. Nevertheless if you increase the temperature further, the Fermi Level will be in the middle of the band gap and in this case you will get electrons and holes contributing to the Transport properties.
Why does Seebeck coefficient decrease with carrier concentration?
The electrical conductivity is proportional to carrier density and mobility (=n.q.u, where n is carrier density n-p), so that the S will decrease with increase of charge carrier concentration. Since the Seebeck is inversely proportional to the carrier density. n increases, Seebeck decreases as you said.
What does a negative Seebeck coefficient mean?
electrons The Seebeck coefficient may have different signs for different materials, negative for negatively charged carriers (electrons) and positive for positively charged carriers (electron holes).
What is the Seebeck coefficient of bismuth telluride?
The Seebeck coefficient is −170 μV/K for the n-type material and 160 μV/K for the p-type material.