Dresden 2014 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 49: Energy materials: Thermoelectrics

HL 49.8: Vortrag

Dienstag, 1. April 2014, 15:45–16:00, POT 051

Thermoelectric power factor of ternary single-crystalline Sb₂Te₃- and Bi₂Te₃-based nanowires — •Svenja Bäßler¹, Tim Böhnert¹, Johannes Gooth¹, Christian Schumacher¹, Eckhard Pippel², and Kornelius Nielsch¹ — ¹Institute of Applied Physics, Universität Hamburg, Jungiusstrasse 11, 20355 Hamburg, Germany — ²Max Planck Institute of Microstructure Physics, Weinberg 2, 06120 Halle, Germany

Nanowires of bismuth antimony telluride and bismuth telluride selenide (Bi₁₅Sb₂₉Te₅₆ and Bi₃₈Te₅₅Se₇) are grown by template-based pulsed electrodeposition. The composition and the crystallinity of the nanowires are determined by high resolution transmission electron microscopy. The thermoelectric properties (Seebeck coefficient and electrical conductivity) of single p- and n-type nanowires with a diameter of 80 nm and 200 nm, respectively, are determined as a function of temperature before and during heating in helium atmosphere up to 300 K along the growth direction of the nanowires. After additional annealing in Te atmosphere at 525 K, significantly enhanced transport properties are observed. Bulk-like power-factors are achieved. In Bi₃₈Te₅₅Se₇ nanowires the Seebeck coefficients increase up to -115 µV K⁻¹ and the thermoelectric power factors up to 2820 µW K⁻² m⁻¹ at room temperature. In Bi₁₅Sb₂₉Te₅₆ nanowires Seebeck coefficients of up to +156 µV K⁻¹ and power factors of up to 1750 µW K⁻² m⁻¹ are obtained at room temperature.

Reference:

S. Bäßler et al. Nanotechnology 24 (2013) 495402