Fluctuation-dissipation in thermoelectric sensors

Thermoelectric materials exhibit correlated transport of charge and heat. The Johnson-Nyquist noise formula 4 k B T R for the spectral density of voltage fluctuations accounts for fluctuations associated solely with Ohmic dissipation. Applying the fluctuation-dissipation theorem, we generalize the J...

Full description

Saved in:
Bibliographic Details
Published in:Europhysics letters 2023-01, Vol.141 (2), p.26002
Main Authors: Tran, N. A. M., Dutt, A. S., Pulumati, N. B., Reith, H., Hu, A., Dumont, A., Nielsch, K., Tremblay, A.-M. S., Schierning, G., Reulet, B., Szkopek, T.
Format: Article
Language:English
Subjects:
Charge materials
Density
Electric potential
Figure of merit
Measuring instruments
Noise measurement
Ohmic dissipation
Theorems
Thermoelectric materials
Voltage
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Thermoelectric materials exhibit correlated transport of charge and heat. The Johnson-Nyquist noise formula 4 k B T R for the spectral density of voltage fluctuations accounts for fluctuations associated solely with Ohmic dissipation. Applying the fluctuation-dissipation theorem, we generalize the Johnson-Nyquist formula for thermoelectrics, finding an enhanced voltage fluctuation spectral density 4 k B T R (1 +  Z D T ) at frequencies below a thermal cut-off frequency f T , where Z D T is the dimensionless thermoelectric device figure of merit. The origin of the enhancement in voltage noise is thermoelectric coupling of temperature fluctuations. We use a wideband , integrated thermoelectric micro-device to experimentally confirm our findings. Measuring the Z D T enhanced voltage noise, we experimentally resolve temperature fluctuations with a root mean square amplitude of at a mean temperature of 295 K. We find that thermoelectric devices can be used for thermometry with sufficient resolution to measure the fundamental temperature fluctuations described by the fluctuation-dissipation theorem.
ISSN:0295-5075
1286-4854
DOI:10.1209/0295-5075/acb009