Enhanced thermoelectric performance of Na-doped PbTe synthesized under high pressure

Abstract

Despite an effective p-type dopant for PbTe, the low solubility of Na limits the fully optimization of thermoelectric properties of Na-doped PbTe. In this work, Na-doped PbTe was synthesized under high pressure. The formation of the desired rocksalt phase with substantially increased Na content leads to a high carrier concentration of 3.

High‐Pressure‐Sintering‐Induced Microstructural Engineering for an Ultimate Phonon Scattering of Thermoelectric Half‐Heusler Compounds

“…For example, Cai et al. reported a κ L reduction of ≈20% for Na‐doped PbTe with a much higher sintering pressure of 6 GPa at 1073 K. [ 49 ] In another example, a reduction of ≈30% was realized for the κ L values in thermoelectric BiCuSeO upon applying a 3 GPa pressure under 973 K. [ 50 ] We thus emphasize the importance of a combination of high sintering pressure and reduced sintering temperature to realize the drastic reduction of κ L . Furthermore, applying HP also reduces the κ values of some Sn‐based compounds including ZrNiSn and NbCoSn with a relatively smaller reduction rate of ≈40% at 300 K. However, the κ of TiNiSn are almost identical between the HP and HT compounds, suggesting that the microstructural features of TiNiSn are not sensitive to the sintering conditions applied herein.…”

Off-Centered Pb Interstitials in PbTe

“…[1,3,4] PbTe-based materials have high thermoelectric performance for middle temperatures applications up to the hot side temperature of 800 K. [5][6][7][8][9][10][11] With Na or Bi doping, suitable charge carriers are doped and the Fermi level is positioned near the optimal band edge positions, resulting in the optimization of the power factor. [12][13][14][15] Alloying or doping with extrinsic Ag, Sb, CdTe, MgTe, MnTe, SrTe, EuTe, or Ag2Te phases leads to low lattice thermal conductivity near ~1 W/m/K. [5,6,8,9,[16][17][18] As a result, many high ZT PbTe-based materials have been developed.…”

Practical High-Performance (Bi,Sb)2Te3-Based Thermoelectric Nanocomposites Fabricated by Nanoparticle Mixing and Scrap Recycling

“…Devices fabricated with thermoelectric materials have advantages of adjustable size, no moving parts, environmental friendliness, and high reliability. − Therefore, thermoelectric research is attracting more global attention. The performance of a thermoelectric material is characterized by a dimensionless figure of merit ZT (= S 2 T / ρκ ), where S is the Seebeck coefficient, T is the absolute temperature, ρ is the electrical resistivity, and κ is a comprehensive thermal conductivity that takes into account carrier thermal conductivity ( κ e ), lattice thermal conductivity ( κ lat ), and bipolar thermal conductivity (κ b ). − However, it is a challenging task to improve ZT due to the intercoupling of S , ρ , and κ (mainly κ e ). Nevertheless, great achievements have been made in pursuing high ZT by means of the phonon-glass-electron-crystal strategy, − nanostructure engineering, − electronic band engineering, − energy-filtering effect, − and defect engineering, − as well as seeking materials with intrinsically low thermal conductivity. − …”