TY  - JOUR
AU  - Claudio, Tania
AU  - Stein, Niklas
AU  - Stroppa, Daniel G.
AU  - Klobes, Benedikt
AU  - Koza, Michael Marek
AU  - Kudejova, Petra
AU  - Petermann, Nils
AU  - Wiggers, Hartmut
AU  - Schierning, Gabi
AU  - Hermann, Raphael
TI  - Nanocrystalline silicon: lattice dynamics and enhanced thermoelectric properties
JO  - Physical chemistry, chemical physics
VL  - 16
IS  - 47
SN  - 1463-9084
CY  - Cambridge
PB  - RSC Publ.
M1  - FZJ-2014-05328
SP  - 25701 - 25709
PY  - 2014
AB  - 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.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000345208200005
C6  - pmid:24848359
DO  - DOI:10.1039/c3cp53749h
UR  - https://juser.fz-juelich.de/record/171763
ER  -