Berlin 2012 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 22: Functional Materials I
MM 22.3: Vortrag
Dienstag, 27. März 2012, 10:45–11:00, H 1029
First-principles study of native point defects in the thermoelectric material Bi2Te3 — •Adham Hashibon and Christian Elsässer — Fraunhofer-Institut für Werkstoffmechanik IWM, Wöhlerstraße 11, 79108 Freiburg, Germany
The thermoelectric properties of Bi2Te3, which is the currently preferred thermoelectric material for energy conversion applications at room temperature, are strongly affected by the nature and concentration of native point defects. However, knowledge of the formation energies of point defects and the manner by which they affect thermoelectric properties is still incomplete. We present a systematic study of formation energies and electronic densities of states for native point defects in Bi2Te3 [1] using first-principles calculations based on density functional theory. Formation energies are calculated assuming the dilute limit of defects by employing an ab-initio thermodynamics approach. Results for the formation energies of the most prominent native point defects, namely vacancies and anti-site defects on the Bi, Te1, and Te2 sub-lattices of the Bi2Te3 structure will be presented and their impact on the thermoelectric properties will be discussed.
[1] Adham Hashibon and Christian Elsässer, Phys. Rev. B 84, 144117 (2011)