Pressure-induced insulator-to-metal transitions for enhancing thermoelectric power factor in bismuth telluride-based alloys.

Title Pressure-induced insulator-to-metal transitions for enhancing thermoelectric power factor in bismuth telluride-based alloys.
Authors A. Gaul; Q. Peng; D.J. Singh; G. Ramanath; T. Borca-Tasciuc
Journal Phys Chem Chem Phys
DOI 10.1039/c7cp01371j
Abstract

First-principles calculations revealing insulator-to-metal transitions in Bi2Te3 and Bi2Te2Se, at 9 GPa and 12.5 GPa, respectively, match with prior experiments. Our electronic band structure calculations and accompanying Boltzmann transport calculations of thermoelectric properties for Bi2-xSbxTe2-ySey alloys explain and predict large power factor changes induced by pressure. Complex band degeneracy changes preceding insulator-to-metal transitions significantly alter the density of states near the Fermi level, and foster the disentangling of the unfavorable coupling between Seebeck coefficient and electrical conductivity. Our findings on pressure-induced changes in thermoelectric power factor provide insights for designing V2VI3-based high-performance thermoelectric materials through strategies such as alloying, high-pressure processing, and strain engineering.

Citation A. Gaul; Q. Peng; D.J. Singh; G. Ramanath; T. Borca-Tasciuc.Pressure-induced insulator-to-metal transitions for enhancing thermoelectric power factor in bismuth telluride-based alloys.. Phys Chem Chem Phys. 2017;19(20):1278412793. doi:10.1039/c7cp01371j

Related Elements

Bismuth

See more Bismuth products. Bismuth (atomic symbol: Bi, atomic number: 83) is a Block P, Group 15, Period 6 element with an atomic radius of 208.98040. The number of electrons in each of Bismuth's shells is 2, 8, 18, 32, 18, 5 and its electron configuration is [Xe] 4f14 5d10 6s2 6p3. Bismuth Bohr ModelThe bismuth atom has a radius of 156 pm and a Van der Waals radius of 207 pm. In its elemental form, bismuth is a silvery white brittle metal. Bismuth is the most diamagnetic of all metals and, with the exception of mercury, its thermal conductivity is lower than any other metal. Elemental BismuthBismuth has a high electrical resistance, and has the highest Hall Effect of any metal (i.e., greatest increase in electrical resistance when placed in a magnetic field). Bismuth is found in bismuthinite and bismite. It is also produced as a byproduct of lead, copper, tin, molybdenum and tungsten extraction. Bismuth was first discovered by Early Man. The name Bismuth originates from the German word 'wissmuth,' meaning white mass.

Tellurium

See more Tellurium products. Tellurium (atomic symbol: Te, atomic number: 52) is a Block P, Group 16, Period 5 element with an atomic radius of 127.60. Tellurium Bohr ModelThe number of electrons in each of tellurium's shells is 2, 8, 18, 18, 6 and its electron configuration is [Kr] 4d10 5s2 5p4. Tellurium was discovered by Franz Muller von Reichenstein in 1782 and first isolated by Martin Heinrich Klaproth in 1798. In its elemental form, tellurium has a silvery lustrous gray appearance. The tellurium atom has a radius of 140 pm and a Van der Waals radius of 206 pm. Elemental TelluriumTellurium is most commonly sourced from the anode sludges produced as a byproduct of copper refining. The name Tellurium originates from the Greek word Tellus, meaning Earth.

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