Influence of nanoinclusions on scattering of holes and phonons and transport coefficients in Bi{sub x}Sb{sub 1-x}Te{sub 3} bulk nanostructures
- GIREDMET Ltd., B. Tolmachevskii per. 5, Moscow 119017 (Russian Federation)
One of the possible ways to increase the thermoelectric figure of merit is the use of bulk nanostructured materials fabricated by melt spinning with subsequent hot pressing or spark plasma sintering. Among a variety of nanostructure types these materials contain regions of initial solid solution with nanometer sized inclusions of different compositions. In the present work the scattering of holes and phonons on nanoinclusions in such p-Bi{sub x}Sb{sub 1-x}Te{sub 3} based materials is considered. The change of transport coefficients due to this scattering mechanism is theoretically estimated. The estimations showed that the reduction of lattice thermal conductivity (about 12-13%) for nanoinclusions of Bi{sub 2}Te{sub 3}-Sb{sub 2}Te{sub 3} solid solution with different compositions is much greater than the change in power factor. Therefore the corresponding increase of the thermoelectric figure of merit for this case is determined mainly by phonon scattering. Also it is shown that the results of estimations depend on phonon spectrum approximation, e.g. in the case of sine-shaped instead of linear phonon spectrum the estimations give two times higher thermal conductivity reduction. - Graphical abstract: Relative phonon thermal conductivity {kappa}{sub ph} change (black line) due to nanoinclusion scattering versus nanoinclusion radius a, and relative thermoelectric power factor change (red line) due to nanoinclusion scattering versus chemical potential {mu} at nanoinclusion size a=1.5 nm and U{sub 0}=-0.146 eV. Highlights: Black-Right-Pointing-Pointer p-Bi{sub x}Sb{sub 1-x}Te{sub 3} solid solutions with nanosized inclusions were considered. Black-Right-Pointing-Pointer Selective hole scattering can increase power factor at high carrier concentrations. Black-Right-Pointing-Pointer Lattice thermal conductivity estimations depend on phonon spectrum approximation. Black-Right-Pointing-Pointer Phonon scattering can reduce lattice thermal conductivity by about 12-13%. Black-Right-Pointing-Pointer The latter factor mainly determines the increase of thermoelectric efficiency.
- OSTI ID:
- 22149811
- Journal Information:
- Journal of Solid State Chemistry, Vol. 193; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
- Country of Publication:
- United States
- Language:
- English
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