RT Journal Article
T1 Evidence of nanostructuring and reduced thermal conductivity in n-type Sb-alloyed SnSe thermoelectric polycrystals
A1 Gainza, Javier
A1 Serrano Sánchez, Federico
A1 Gharsallah, M.
A1 Carrascoso, Felix
A1 Bermudez, J.
A1 Dura, Oscar Juan
A1 Mompean, Federico
A1 Biskup Zaja, Nevenko
A1 Melendez, Juan José
A1 Martinez, José
A1 Alonso, José Antonio
A1 Nemes, Norbert Marcel
AB SnSe has been recently reported as an attractive thermoelectric material, with an extraordinarily high, positive, Seebeck coefficient. Here, we describe the synthesis, structural, microscopic, and thermoelectric characterization of Sn1–xSbxSe intermetallic alloys prepared by a straightforward arc-melting technique. Sb-doped tin selenide was synthesized as strongly nanostructured polycrystalline pellets. Neutron diffraction studies reveal that Sb is placed at the Sn sublattice in the crystal structure, showing concentrations as high as 30%, and generates a significant number of Sn vacancies, while the increase of the interlayer distances favors the nanostructuration. The material is nanostructured both out-of-plane in nanometer-scale layers and in-plane by ∼5 nm undulations of these layers. This nanostructuring, along with an increased amount of Sn vacancies, accounts for a reduction of the thermal conductivity, which is highly desirable for thermoelectric materials. The phonon mean free path is estimated to be on the order of 2 nm from low temperature, thermal conductivity, and specific heat, in accordance with the nanostructuration observed by high-resolution transmission electron microscopy. The thermal conductivity of SnSe is characterized by three independent techniques to assure a room temperature value of Sn0.8Sb0.2Se of κ ∼ 0.6 W/m K. The freshly prepared Sb-doped compounds exhibit an abrupt change in the type of charge carriers, leading to large, negative Seebeck coefficients, although the arc-melt synthesized pellets remain too resistive for thermoelectric applications. Cold-pressed pellets evolve to be p-type at room temperature, but reproducibly turn n-type around 500 K, with increased electrical conductivity and maximum observed figure of merit, ZT ∼ 0.3 at 908 K.
PB American Institute of Physics (AIP)
SN 0021-8979
YR 2019
FD 2019
LK https://hdl.handle.net/20.500.14352/91729
UL https://hdl.handle.net/20.500.14352/91729
LA eng
NO J. Gainza, F. Serrano-Sánchez, M. Gharsallah, F. Carrascoso, J. Bermúdez, O. J. Dura, F. J. Mompean, N. Biskup, J. J. Meléndez, J. L. Martínez, J. A. Alonso, N. M. Nemes; Evidence of nanostructuring and reduced thermal conductivity in n-type Sb-alloyed SnSe thermoelectric polycrystals. J. Appl. Phys. 28 July 2019; 126 (4): 045105. https://doi.org/10.1063/1.5108569
NO Ministerio de Ciencia, Innovación y Universidades (España)
NO Junta de Extremadura
DS Docta Complutense
RD 18 abr 2025