Regensburg 2013 – wissenschaftliches Programm

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DS: Fachverband Dünne Schichten

DS 12: Poster Session II: Functionalized semiconductor nanowires (jointly with HL); Resistive switching (jointly with DF, KR, HL); Thermoelectric materials

DS 12.16: Poster

Montag, 11. März 2013, 17:00–20:00, Poster B1

Thermoelectric Transport Properties of GeTe Rich GeTe-Sb₂Te₃ Thin Films — •Felix R. L. Lange¹, Ernst-Roland Sittner¹, Karl Simon Siegert¹, Peter Jost¹, and Matthias Wuttig^1,2 — ¹I. Physikalisches Institut (IA), RWTH Aachen University, 52056 Aachen, Germany — ²JARA - Fundamentals of Future Information Technology, RWTH Aachen University, Germany

Phase change materials (PCM) are a class of alloys that can be reversibly and rapidly switched between the amorphous and the crystalline state. Since these two states differ significantly in their physical properties such as reflectivity and resistivity they are well suited for future nonvolatile data storage applications. Some PCM along the pseudo-binary line between GeTe and Sb₂Te₃ exhibit a rather unusual combination of physical properties which render these alloys a potential p-type thermoelectric. These alloys allow access to a meta-stable cubic phase where one lattice site is randomly occupied by Ge, Sb and a certain amount of structural vacancies. Only recently Siegrist et al. identified disorder in these alloys as the cause of a metal to insulator transition. The degree of disorder can be affected by two independent parameters: stoichiometry and annealing conditions. Since disorder affects both, electrical and vibrational degrees of freedom, this opens up a pathway to tailor electrical and thermal transport properties independently. Using this concept we report enhanced thermoelectric efficiencies for GeTe rich GeTe-Sb₂Te₃ thin films prepared under different annealing conditions [1]. [1] E. R. Sittner et al., Phys Status Solidi A, DOI 10.1002/pssa.201228397 (2012)