Low thermal conductivity and improved figure of merit in fine-grained binary PbTe thermoelectric alloys
Низкая теплопроводность и повышённый показатель эффективности в мелкозернистых бинарных термоэлектрических сплавах PbTe
2008-12-10
SCID: 54.1/5sfhbnn3
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fine-grained PbTegrain boundary phonon scatteringhot pressinglow thermal conductivityreflux chemical synthesis
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Abstract (AI)
Fine-grained binary PbTe thermoelectric materials have been fabricated by a combination of a reflux chemical synthesis and hot pressing. The grain sizes of the hot pressed bulk samples varied from 200 to 400 nm, which significantly contributed to the thermal conductivity reduction due to the enhanced phonon scattering at grain boundaries. Low room temperature thermal conductivity of 0.75 W m−1 K−1 has been obtained after porosity correction for the sample with a grain size of ∼200 nm. The highest figure of merit ZT of the fine-grained binary PbTe bulk sample reaches 0.8 at 580 K although the composition was unoptimized. The value is comparable to that of the best PbTe alloys.
Key Findings
1
A low room-temperature thermal conductivity of 0.75 W m−1 K−1 (porosity-corrected) was achieved for the ~200 nm grain-size sample.
2
Fine-grained binary PbTe bulk samples with grain sizes 200–400 nm were fabricated via reflux chemical synthesis and hot pressing.
3
Grain sizes around 200 nm significantly reduced thermal conductivity through enhanced phonon scattering at grain boundaries.
4
The achieved ZT of 0.8 is comparable to that of the best PbTe alloys.
5
The fine-grained binary PbTe sample attained a maximum figure of merit ZT = 0.8 at 580 K despite unoptimized composition.
Research Object
Fine-grained binary PbTe bulk thermoelectric materials (hot-pressed, grain sizes ~200–400 nm)
Research Subject
Thermal conductivity reduction and resulting thermoelectric performance (figure of merit ZT), including phonon-boundary scattering effects and measured ZT up to 0.8 at 580 K
Publication Details
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2008-12-10
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