Near field characterization of plasmonic nanostructures with electron energy loss spectroscopy

Electron energy loss spectroscopy (EELS) in combination with scanning transmission electron microscopy (STEM) was used to characterize the near field distribution of plasmonic nanostructures. The results were compared to optical experiments as well as numerical simulations. This work focuses on the near field properties of split-ring resonators (SRRs), which are one of the most prominent examples of metamaterials. The main results of this thesis are: (i) Proof of Babinet's principle in the near-infrared and visible regime, (ii) visualization of bright and dark modes in coupled nanoparticles, and (iii) a three dimensional analysis of the plasmonic near field of an individual SRR

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Quantum-Spillover-Enhanced Surface-Plasmonic Absorption at the Interface of Silver and High-Index Dielectrics

We demonstrate an unexpectedly strong surface-plasmonic absorption at the interface of silver and high-index dielectrics based on electron and photon spectroscopy. The measured bandwidth and intensity of absorption deviate significantly from the classical theory. Our density-functional calculation well predicts the occurrence of this phenomenon. It reveals that due to the low metal-to-dielectric work function at such interfaces, conduction electrons can display a drastic quantum spillover, causing the interfacial electron-hole pair production to dominate the decay of surface plasmons. This finding can be of fundamental importance in understanding and designing quantum nanoplasmonic devices that utilize noble metals and high-index dielectrics.National Science Foundation (U.S.) (Award CMMI-1120724)United States. Air Force Office of Scientific Research. Multidisciplinary University Research Initiative (Grant FA9550-12-1-0488

Das Umweltbewußtsein der 16-jährigen: Erkenntnisse und Konsequenzen für die Umwelterziehung in der Schule

Braun A. Das Umweltbewußtsein der 16-jährigen: Erkenntnisse und Konsequenzen für die Umwelterziehung in der Schule. In: von Cube F, ed. Umweltpädagogik: Ansätze, Analysen, Ausblicke. Heidelberg: Schindele; 1988: 133-146