Scattering of Current Carriers and Transport Phenomena in Lead Chalcogenides II. Experiment

Ravich, Yu. I.; Efimova, B. A.; Tamarchenko, V.I.

doi:10.1002/pssb.2220430202

Cited by 134 publications

(91 citation statements)

References 7 publications

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“…The matching between the L-pockets' Luttinger volumes and Hall numbers implies that PbTe, up to a carrier concentration of p H = (9.4 ± 0.6) × 10 19 cm −3 , is single band, that is, all the carriers contributing to conduction belong to the L band. This result implies that the band offset between the L and Σ valence band maxima is underestimated in our DFT calculations, as well as all previously published band-structure calculations 8,13,33,34,[42][43][44][45][46] , which predict the appearance of the Σ band at a hole concentration of the order of p ≈ 1 × 10 19 cm −3 . The evolution of the three high symmetry L-pocket cross-sectional areas, in frequency units (f min , f max and f [100] ), with Hall number is plotted in figure 13.…”

Section: A Fermi Surface Topologysupporting

confidence: 83%

Fermi surface evolution of Na-doped PbTe studied through density functional theory calculations and Shubnikov–de Haas measurements

et al. 2016

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We present a combined experimental and theoretical study of the evolution of the low-temperature Fermi surface of lead telluride, PbTe, when holes are introduced through sodium substitution on the lead site. Our Shubnikov-de-Haas measurements for samples with carrier concentrations up to 9.4 × 10 19 cm −3 (0.62 Na atomic %) show the qualitative features of the Fermi surface evolution (topology and effective mass) predicted by our density functional (DFT) calculations within the generalized gradient approximation (GGA): we obtain perfect ellipsoidal L-pockets at low and intermediate carrier concentrations, evolution away from ideal ellipsoidicity for the highest doping studied, and cyclotron effective masses increasing monotonically with doping level, implying deviations from perfect parabolicity throughout the whole band. Our measurements show, however, that standard DFT calculations underestimate the energy difference between the L-point and Σ-line valence band maxima, since our data are consistent with occupation of a single Fermi surface pocket over the entire doping range studied, whereas the calculations predict an occupation of the Σ-pockets at higher doping. Our results for low and intermediate compositions are consistent with a non-parabolic Kane-model dispersion, in which the L-pockets are ellipsoids of fixed anisotropy throughout the band, but the effective masses depend strongly on Fermi energy.

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Section: A Fermi Surface Topologysupporting

confidence: 83%

Fermi surface evolution of Na-doped PbTe studied through density functional theory calculations and Shubnikov–de Haas measurements

et al. 2016

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“…Figure 4.2 shows the calculated room temperature Seebeck coefficient as a function of the doping n and fixed nanoinclusion volume fraction x=5%. We note the excellent agreement between the experimentally measured S (filled circles) [53,54] and that calculated numerically (solid line) for bulk PbTe. In addition, one can see that for any nanoinclusion radius, the Seebeck coefficient is always increased compared to that of the inclusion-free system.…”

Section: Enhancement Of the Seebeck Coefficient And Power Factorsupporting

confidence: 62%

Compositional ordering and stability in nanostructured, bulk thermoelectric alloys.

Hekmaty¹,

Faleev²,

Medlin³

et al. 2009

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Thermoelectric materials have many applications in the conversion of thermal energy to electrical power and in solid-state cooling. One route to improving thermoelectric energy conversion efficiency in bulk material is to embed nanoscale inclusions. This report summarize key results from a recently completed LDRD project exploring the science underpinning the formation and stability of nanostructures in bulk thermoelectric and the quantitative relationships between such structures and thermoelectric properties. 4 ACKNOWLEDGMENTS

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“…changes and approaches À 1 as concentrations increase, again in good agreement with theory and experimental data for the effective mass. At high-temperature, strong electronic-scattering mechanisms, non-parabolicity of the bands and/or scattering from high-frequency vibrations of the lattice (optical phonons) possibly have a role to rapidly decrease the values of exponents at high temperature 37,38 .…”

Section: Resultsmentioning

confidence: 99%

Contrasting role of antimony and bismuth dopants on the thermoelectric performance of lead selenide

et al. 2014

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Increasing the conversion efficiency of thermoelectric materials is a key scientific driver behind a worldwide effort to enable heat to electricity power generation at competitive cost. Here we report an increased performance for antimony-doped lead selenide with a thermoelectric figure of merit of B1.5 at 800 K. This is in sharp contrast to bismuth doped lead selenide, which reaches a figure of merit of o1. Substituting antimony or bismuth for lead achieves maximum power factors between B23-27 mWcm À 1 K À 2 at temperatures above 400 K. The addition of small amounts (B0.25 mol%) of antimony generates extensive nanoscale precipitates, whereas comparable amounts of bismuth results in very few or no precipitates. The antimony-rich precipitates are endotaxial in lead selenide, and appear remarkably effective in reducing the lattice thermal conductivity. The corresponding bismuth-containing samples exhibit smaller reduction in lattice thermal conductivity.

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Scattering of Current Carriers and Transport Phenomena in Lead Chalcogenides II. Experiment

Cited by 134 publications

References 7 publications

Fermi surface evolution of Na-doped PbTe studied through density functional theory calculations and Shubnikov–de Haas measurements

Fermi surface evolution of Na-doped PbTe studied through density functional theory calculations and Shubnikov–de Haas measurements

Compositional ordering and stability in nanostructured, bulk thermoelectric alloys.

Contrasting role of antimony and bismuth dopants on the thermoelectric performance of lead selenide

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