Berlin 2012 – wissenschaftliches Programm

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DS: Fachverband Dünne Schichten

DS 42: Thermoelectric materials IV: Glass, sintered materials (Focused session – Organizers: Meyer, Heiliger)

DS 42.1: Topical Talk

Freitag, 30. März 2012, 11:30–12:00, H 2032

Employing laterally nanostructured ZnO-based thin-films as model systems for studying interface effects in themoelectrics — •Peter J. Klar — I. Physikalisches Institut, Justus-Liebig-Universität Gießen, Germany

The morphology of the interface between two materials has a major impact on the transport properties across this interface. Interface properties at different length scales ranging from the atomic to the micrometer scale affect phonons and electrons differently. Controlling these effects allows one to tune and optimize the thermoelectric properties of materials. Laterally nanostructured thin-films offer the advantage that the interfaces between its constituents are easily accessible by local probes such as electron microscopy, micro-Raman and micro-photoluminescence spectroscopy as well as local transport measurements, which allows one to correlate the interface structure with global and local transport properties and thus to establish structure-property relationships. In particular, the controlled fabrication of interfaces of different morphology by self-aligned patterning combining lithographic steps, etching steps, and rf-sputtering will be introduced. Examples of the impact of the interface structure on the transport properties and the correlation between their global and local properties will be discussed for various series of laterally nanostructured ZnO thin-films. The results suggest that in many nanostructured thermoelectrics the impact of diffusion, band bending or percolation on thermoelectric properties is more significant than that of density of states changes and confinement anticipated at reduced dimensions.