Large thermoelectric power factors and impact of texturing on the thermal conductivity in polycrystalline SnSe
POPURI, Srinivasa Rao
Institute of Chemical Sciences and Centre for Advanced Energy Storage and Recovery
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Institute of Chemical Sciences and Centre for Advanced Energy Storage and Recovery
POPURI, Srinivasa Rao
Institute of Chemical Sciences and Centre for Advanced Energy Storage and Recovery
Institute of Chemical Sciences and Centre for Advanced Energy Storage and Recovery
BOS, Jan-Willem G.
Institute of Chemical Sciences and Centre for Advanced Energy Storage and Recovery
< Réduire
Institute of Chemical Sciences and Centre for Advanced Energy Storage and Recovery
Langue
en
Article de revue
Ce document a été publié dans
Journal of Materials Chemistry C. 2016, vol. 4, n° 8, p. 1685-1691
Royal Society of Chemistry
Résumé en anglais
Single crystals of SnSe have been reported to have very high thermoelectric efficiencies with a maximum figure merit zT = 2.5. This outstanding performance is due to ultralow thermal conductivities. We report on the synthesis ...Lire la suite >
Single crystals of SnSe have been reported to have very high thermoelectric efficiencies with a maximum figure merit zT = 2.5. This outstanding performance is due to ultralow thermal conductivities. We report on the synthesis of highly textured polycrystalline SnSe ingots with large single-crystal magnitude power factors, S2/ρ = 0.2–0.4 mW m−1 K−2 between 300–600 K, increasing to 0.9 mW m−1 K−2 at 800 K, and bulk thermal conductivity values κ300K = 1.5 W m−1 K−1. However, small SnSe ingots, which were measured in their entirety, were found to have a substantially reduced κ300K = 0.6 W m−1 K−1. Microscopy and diffraction revealed two distinct types of texturing within the hot-pressed ingots. In the interior, large coherent domains of SnSe platelets with a ∼45° orientation with respect to the pressing direction are found, while the platelets are preferentially oriented at 90° to the pressing direction at the top and bottom of the ingots. Fitting the κ(T) data suggests an increase in defect scattering for the smaller ingots, which is in keeping with the presence of regions of structural disorder due to the change in texturing. Combining the measured S2/ρ with the bulk ingot κ values yields zT = 1.1 at 873 K.< Réduire
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