Enhanced thermoelectric performance of n-type (PbSe)n(Sb2Te3) pseudo-binary via Zn filling and Ag2Se compositing

Lead selenide (PbSe) is considered to be decent candidate replacing lead telluride (PbTe) as intermediate temperature (600-900 K) thermoelectric application due to its lower intrinsic lattice thermal conductivity, higher thermal stability, and larger abundance of Se than Te. To improve the thermoelectric performance of n-type PbSe, we constructed an n-type PbSe-Sb2Se3 pseudo-binary via alloying Sb2Se3 into PbSe matrix to obtain a reduced lattice thermal conductivity at a broad temperature range. Next, we introduced extra Zn into matrix to optimize the electron concentration. Last, we further added excess Ag2Se to modulate the lattice thermal conductivity at temperature < 523 K. Eventually, we obtained an ultralow lattice thermal conductivity of similar to 0.40 W m-1 K-1 and a large peak ZT of similar to 1.36 at 773 K in the composition of (PbSe)(40)(Sb2Se3)Zn-0.1(Ag2Se)(0.75); meanwhile, the average ZT between 323 and 773 K is as high as similar to 0.78, revealing a significant improvement over pristine PbSe.(c) 2022 Elsevier B.V. All rights reserved.