The Effect of Reactive Electric Field-Assisted Sintering of MoS 2 /Bi 2 Te 3 Heterostructure on the Phase Integrity of Bi 2 Te 3 Matrix and the Thermoelectric Properties.

In this work, a series of Bi 2 Te 3 /X mol% MoS 2 (X = 0, 25, 50, 75) bulk nanocomposites were prepared by hydrothermal reaction followed by reactive spark plasma sintering (SPS). X-ray diffraction analysis (XRD) indicates that the native nanopowders, comprising of Bi 2 Te 3 /MoS 2 heterostructure, are highly reactive during the electric field-assisted sintering by SPS. The nano-sized MoS 2 particles react with the Bi 2 Te 3 plates matrix forming a mixed-anion compound, Bi 2 Te 2 S, at the interface between the nanoplates. The transport properties characterizations revealed a significant influence of the nanocomposite structure formation on the native electrical conductivity, Seebeck coefficient, and thermal conductivity of the initial Bi 2 Te 3 matrix. As a result, enhanced ZT values have been obtained in Bi 2 Te 3 /25 mol% MoS 2 over the temperature range of 300-475 K induced mainly by a significant increase in the electrical conductivity.