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Title: Enhanced thermoelectric figure of merit in strained Tl-doped Bi{sub 2}Se{sub 3}

We explain recent experimental findings on Tl-doped Bi{sub 2}Se{sub 3} by determining the electronic and transport properties by first-principles calculations and semi-classical Boltzmann theory. Though Tl-doping introduces a momentum-dependent spin-orbit splitting, the effective mass of the carriers is essentially not modified, while the band gap is reduced. Tl is found to be exceptional in this respect as other dopants modify the dispersion, which compromises thermoelectricity. Moreover, we demonstrate that only after Tl-doping strain becomes an efficient tool for enhancing the thermoelectric performance. A high figure of merit of 0.86 is obtained for strong p-doping (7 × 10{sup 20} cm{sup −3}, maximal power factor) at 500 K under 2% tensile strain.
Authors:
; ;  [1]
  1. PSE Division, KAUST, Thuwal 23955-6900 (Saudi Arabia)
Publication Date:
OSTI Identifier:
22311138
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 3; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; BISMUTH SELENIDES; BOLTZMANN EQUATION; CARRIERS; COMPUTERIZED SIMULATION; DISPERSIONS; DOPED MATERIALS; EFFECTIVE MASS; ELECTRIC CONDUCTIVITY; ORBITS; POWER FACTOR; SPIN; STRAINS; THALLIUM ADDITIONS; THERMOELECTRICITY