This title appears in the Scientific Report :
2014
Please use the identifier:
http://dx.doi.org/10.1039/c3cp53749h in citations.
Nanocrystalline silicon: lattice dynamics and enhanced thermoelectric properties
Nanocrystalline silicon: lattice dynamics and enhanced thermoelectric properties
Silicon has several advantages when compared to other thermoelectric materials, but until recently it was not used for thermoelectric applications due to its high thermal conductivity, 156 W K−1 m−1 at room temperature. Nanostructuration as means to decrease thermal transport through enhanced phonon...
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Personal Name(s): | Claudio, Tania |
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Stein, Niklas / Stroppa, Daniel G. / Klobes, Benedikt / Koza, Michael Marek / Kudejova, Petra / Petermann, Nils / Wiggers, Hartmut / Schierning, Gabi / Hermann, Raphael (Corresponding Author) | |
Contributing Institute: |
Streumethoden; JCNS-2 JARA-FIT; JARA-FIT Streumethoden; PGI-4 |
Published in: | Physical chemistry, chemical physics, 16 (2014) 47, S. 25701 - 25709 |
Imprint: |
Cambridge
RSC Publ.
2014
|
DOI: |
10.1039/c3cp53749h |
PubMed ID: |
24848359 |
Document Type: |
Journal Article |
Research Program: |
JCNS In-house Research with PNI Neutrons Exploratory materials and phenomena Spin-based and quantum information |
Publikationsportal JuSER |
Silicon has several advantages when compared to other thermoelectric materials, but until recently it was not used for thermoelectric applications due to its high thermal conductivity, 156 W K−1 m−1 at room temperature. Nanostructuration as means to decrease thermal transport through enhanced phonon scattering has been a subject of many studies. In this work we have evaluated the effects of nanostructuration on the lattice dynamics of bulk nanocrystalline doped silicon. The samples were prepared by gas phase synthesis, followed by current and pressure assisted sintering. The heat capacity, density of phonons states, and elastic constants were measured, which all reveal a significant, ≈25%, reduction in the speed of sound. The samples present a significantly decreased lattice thermal conductivity, ≈25 W K−1 m−1, which, combined with a very high carrier mobility, results in a dimensionless figure of merit with a competitive value that peaks at ZT ≈ 0.57 at 973 °C. Due to its easily scalable and extremely low-cost production process, nanocrystalline Si prepared by gas phase synthesis followed by sintering could become the material of choice for high temperature thermoelectric generators. |