Berlin 2012 – scientific programme

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DS: Fachverband Dünne Schichten

DS 33: Thermoelectric materials II: Reduced dimensionality (Focused session – Organizers: Meyer, Heiliger)

DS 33.3: Talk

Thursday, March 29, 2012, 12:00–12:15, H 2032

Nano-sized semiconductor pillars for thermoelectric applications — •Thorben Bartsch, Matthias Schmidt, Christian Heyn, and Wolfgang Hansen — Institut für Angewandte Physik, Jungiusstr. 11, D-20355 Hamburg,Germany

Nanostructures are an attempt to enlarge the efficiency of thermoelectric devices by drastic reduction of the thermal conductivity and enhancement of the electrical properties [1]. We fabricate novel, epitaxially grown air-gap heterostructures that contain a nanometer sized air gap stabilized by epitaxial semiconductor pillars with length of only few nanometers. Caused by the small dimension and the low density of the pillars, the thermal conductance is several orders of magnitude smaller than in comparable bulk structures. The measured conductance can be described with a simple model of ballistic phonon transport through the pillars [2]. Here, first experimental results will be discussed that probe the thermoelectric properties of the semiconductor nanopillars in the air-gap heterostructures.

[1] K. Nielsch et al. Adv. Energy Mater. 1, 713 (2011)

[2] Th. Bartsch et al. submitted , published on arXive:http://arxiv.org/abs/1111.1164