Maximizing thermoelectric performance of AgPb SbTe+2 by optimizing spark plasma sintering temperature

Effect of the Processing Route on the Thermoelectric Performance of Nanostructured CuPb18SbTe20

“…Both the slow cooled (SS) and the flash sintered samples demonstrated an ultra-low latt  0.58 W/mK at 700 K, which is comparable with literature values of LAST alloys prepared by different techniques 50,52,62. The low latt values of AgPb18SbTe20 in the literature were widely reported to be due to the effect of phonon scattering.…”

“…Both the SS and flash-sintered samples demonstrated an ultralow κ latt ∼ 0.58 W/m•K at 700 K, which is comparable with literature values of LAST alloys prepared by different techniques. 50,52,62 The low κ latt values of AgPb 18 SbTe 20 in the literature were widely reported to be due to the effect of phonon scattering. The scattering defects have been hypothesized to be the presence of either strain fields or endotaxially embedded nanodots (rich in Ag and Sb) in the PbTe matrix.…”

“…5 Several strategies, some of them mentioned earlier, have successfully been employed on the binary PbTe compound to maximize its performance. Most notably, Kanatzidis' group 48 made a breakthrough in 2004, when a material of composition AgPb18SbTe20, abbreviated as LAST (Lead-Antimony-Silver-Tellurium), reportedly exhibited a high zT  2.2 at 800 K. Independent studies based on different synthesis routes of this LAST alloy have reported consistently high zT in the range of 1.3 -1.5 at around 700 K. [49][50][51][52] Various explanations for the very high zT of LAST alloys have been proposed: (i) the presence of coherent, endotaxially embedded nanoscopic inhomogeneity or nanodots (rich in Ag and Sb) in the PbTe matrix and/or modulated nanostructures and atomic ordering; 48,53-57 and (ii) to the presence of resonance states in the electronic band structure of bulk PbTe when Ag and Sb partially substitute for Pb and/or sizable band-gap widening caused by nanodopant induced lattice strains. [58][59][60] Building on the work by Kanatzidis et al, 48 several papers have been published on replacing one or more of the elements in LAST alloys in an attempt to improve zT, such as substituting K for Ag to make n-type K1-xPbm+Sb1+Tem+2 (zT  1.6 at 750 K), 15 Na for Ag to make p-type Na1-xPbmSbyTem+2 (zT  1.7 at 650 K), 11 La for Sb to make n-type AgnPb1-xLaxTe (zT  1.2 at 720 K) 61 , Bi for Sb to make n-type AgPbmBiTem+2 (zT  0.5 at 650 K), 62 and Cl codoped with Se for Te to make n-type AgPbmSbSe(m+2)-xClx (zT  1.3 at 873 K).…”

“…Several strategies, some of them mentioned earlier, have successfully been employed on the binary PbTe compound to maximize its performance. Most notably, Kanatzidis’ group made a breakthrough in 2004 when a material of composition AgPb 18 SbTe 20 , abbreviated as LAST ( L ead– A ntimony– S ilver– T ellurium), reportedly exhibited a high zT ∼ 2.2 at 800 K. Independent studies based on different synthesis routes of this LAST alloy have reported consistently high zT in the range of 1.3–1.5 at around 700 K. − Various explanations for the very high zT of LAST alloys have been proposed: (i) the presence of coherent, endotaxially embedded nanoscopic inhomogeneity or nanodots (rich in Ag and Sb) in the PbTe matrix and/or modulated nanostructures and atomic ordering; ,− (ii) the presence of resonance states in the electronic band structure of bulk PbTe when Ag and Sb partially substitute for Pb and/or sizable band gap widening caused by nanodopant-induced lattice strains. − …”

Preparation and thermoelectric properties of Cu1.8S/CuSbS2 composites

“…For nondegenerate semiconductor, L was calculated to be 1.485 × 10 -8 W•Ω•K -2 based on the assumption of r = −1/2 for acoustic phonon scattering according to Eq (10). where k B is the Boltzmann constant, e is the electron charge, and r is the scattering factor[23,24].…”