Structure and Thermoelectric Properties of Spark Plasma Sintered Ultrathin PbTe Nanowires

Abstract

Solution-synthesized thermoelectric nanostructured materials have the potential to have lower cost and higher performance than materials synthesized by solid-state methods. Herein we present the synthesis of ultrathin PbTe nanowires, which are compressed by spark plasma sintering at various temperatures in the range of 405-500 °C. The resulting discs possess grains with sizes of 5-30 μm as well as grains with sizes on the order of the original 12 nm diameter PbTe nanowires. This micro- and nanostructure leads to a significantly reduced thermal conductivity compared to bulk PbTe. Careful electron transport analysis shows suppressed electrical conductivity due to increased short-range and ionized defect scatterings, while the Seebeck coefficient remains comparable to the bulk value. The PbTe nanowire samples are found unintentionally p-type doped to hole concentrations of 2.16-2.59 × 10(18) cm(-3). The maximum figure of merit achieved in the unintentionally doped spark plasma sintered PbTe nanowires is 0.33 at 350 K, which is among the highest reported for unintentionally doped PbTe at low temperatures.

Capping nanoparticles with graphene quantum dots for enhanced thermoelectric performance

“…However, NPs generally suffer from alloying and fusing at elevated temperatures, which weakens these effects and leads to an irreversibly decreased Seebeck coefficient 45,46. By capping the PbTe NPs with GQDs, we demonstrate that thermally stable GQDs effectively lessen sintering of NPs in the composite.…”

A strategy to optimize the thermoelectric performance in a spark plasma sintering process

“…We therefore maintained a holding time of 5 min in this study. To examine whether the proposed strategy can be applied to other thermoelectric material systems, two reported (Bi,Sb) 2 Te 3 and PbTe material systems were examined accordingly2829 (see Supplementary, Fig. S1).…”

Nanowire Genome: A Magic Toolbox for 1D Nanostructures

“…By using hydrazine or ascorbic acid, a variety of 2G metal telluride NWs can be prepared through the chemical transformation of the 1G Te NWs. [102,146,147,[149][150][151][152][153][155][156][157][158][159][160] If the transformation achieves complete remission is fully completed, the pure phase of metal telluride NWs can be obtained. As shown in Figure 6b-f, uniform Bi 2 Te 3 , CdTe, Ag 2 Te, PbTe, and Cu 2 Te NWs with a diameter of sub-10 nm and a length of tens of micrometers can be synthesized.…”