Lead-free MnTe mid-temperature thermoelectric materials: facile synthesis, p-type doping and transport properties

Abstract

This work reveals the effectiveness of sodium doping in MnTe as a thermoelectric material fabricated by a facile method.

Substantial thermoelectric enhancement achieved by manipulating the band structure and dislocations in Ag and La co-doped SnTe

“…The thermal conductivity (κ) was determined by the expression κ = DC p , where D was the thermal diffusivity, C p was the specific heat indexed to the data from Ref. [40], and  was the density. The thermal diffusivity (D) was directly measured using the laser flash diffusivity method (Netzsch LFA-467 HT, Germany) at 300-873 K under an argon flow.…”

“…The electronic structures of pristine SnTe, Ag doped, Ag and La co-doped SnTe were simulated using the density functional theory (DFT) in the Vienna Ab initio Simulation Package (VASP) [41]. The projectoraugmented-wave (PAW) [40] and generalized gradient approximation (GGA) to exchange-correlation term with the Perdew, Burke, and Ernzerhof (PBE) were used in the computations [43]. The cut-off energy of plane-wave set was 400 eV.…”

Regulation of Ge vacancies through Sm doping resulting in superior thermoelectric performance in GeTe

“…12,13 However, the strong coupling of the TE parameters makes it difficult to enhance the ZT due to the opposite dependencies on the carrier concentration for S and σ , the proportional relationship between κ e and σ , and the fact that the introduced structure to scatter phonons may also deteriorate the electrical transport properties because of the severe scattering of carriers to decrease the carrier mobility. 14,15…”

Cubic AgMnSbTe3 Semiconductor with a High Thermoelectric Performance

“…29,30 MnTe is a p-type chalcogenide semiconductor with a direct band gap of 1.3 eV and indirect band gap of 0.8 eV at room temperature, which has attracted increasing attention among the thermoelectric community as a lead-free alternative. 31,32 However, the low electrical conductivity of pristine MnTe owing to its low carrier concentration (∼10 18 cm −3 ) and low hole mobility (∼6 cm 2 V −1 s −1 ) severely restricts its thermoelectric performance, with a ZT value of only ∼0.5 at 823 K. 33 Therefore, it is of interest to enhance its electrical conductivity through substitution of monovalent metals (e.g., Ag, 32 Cu, 34 Li, 35 Na 36 ) for Mn and incorporation of inclusions with high electrical conductivities (e.g., SnTe, 37 Ag 2 S, 38 graphene, 39 Sb 2 Te 3 ). 40 Generally, MnTe crystallizes in a hexagonal crystal structure with a space group of P6 3 /mmc (No.…”