Synthesis and characterisation of PbTe thermoelectric nanopowders via a gas induced reduction route

Abstract

PbTe nanopowders were synthesised by a gas induced reduction (GIR) method using Pb(NO 3 ) 2 and TeO 2 as raw materials and hydrazine as reductant at different temperatures. The nanopowders were characterised by X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM) equipped with energy dispersive X-ray spectroscopy. The morphology of the PbTe powders varied with synthesis temperatures. As the synthesis temperature increased, the powder shape gradually changed from spherical to rod-like, i.e. the morphology of the powder can be controlled by adjusting the synthesis temperature. The spherical PbTe particles with diameter of 100 nm were synthesised at 348 K for 24 h, while PbTe nanorods with 200-300 nm in diameter and about 2 mm in length were prepared at 423 K for 24 h. Based on the experimental results and analysis, the growth mechanism of the PbTe nanopowders was proposed. The powders after cold pressing exhibit very high Seebeck coefficient of y405 mV K 21 .

Low temperature formation of rectangular PbTe nanocrystals and their thermoelectric properties

“…19 Chen et al synthesized aggregated PbTe nanomaterials utilizing a gas-induced reduction process at 348 K for 24 hours. 20 Fardy et al prepared PbTe chalcogenide nanowires under an inert atmosphere at high temperature. 1 Papageorgiou et al prepared n-type PbTe NCs at 430 1C.…”