Regensburg 2022 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 35: Nanomaterials: Structure & Properties
MM 35.3: Vortrag
Donnerstag, 8. September 2022, 16:15–16:30, H46
Tuning the Electronic Properties of Mesocrystals — •Stefan Manuel Schupp1, Christian Jenewein2, Bing Ni2, Lukas Schmidt-Mende1, and Helmut Cölfen2 — 1Unitversity of Konstanz, Department of Physics, Universitätsstraße 10, 78462 Konstanz, Germany — 2Unitversity of Konstanz, Department of Chemistry, Universitätsstraße 10, 78462 Konstanz, Germany
Colloidal crystals consisting of periodically aligned nanocrystalline building blocks, so-called mesocrystals, are promising candidates for nanostructured metamaterials. The high degree of order of the nanoparticles in the crystal results in a well-defined facet-to-facet distance which is determined by the used capping agents. In this work, we were able to grow micrometer-sized platinum nanocube-based mesocrystals with various capping agents and perform electrical measurements on individual crystals with a nanoprobing system. The extracted resistances increase with larger interparticle distances which can be attributed to the predominantly thermally activated tunneling mechanism in these superstructures. However, an additional annealing step leads to a decrease in resistance by seven orders of magnitude due to formed mineral bridges. After this treatment, the electronic properties are mainly determined by the nanomaterial itself. Finally, we were able to transfer these findings onto multi component superstructures consisting of platinum and iron oxide nanocubes. In these binary mesocrystals the ratio of the nanoparticle types can be varied to tune the electrical conductivity even further while simultaneously allowing to combine properties of both nanomaterials.