| Project No. | Project Name | Responsible |
|---|---|---|
| G7 | Spectroscopic characterization of nanostructures and relevant interfaces | Prof. Dr. Dietrich R. T. ZAHN |
Enhanced optical response via plasmonic effects of highly ordered metallic nanostructures
Based on our current work on metal deposition onto organic molecular layers where significant surface enhanced Raman scattering (SERS) intensities are detected for various metals (Ag, In, and even Mg) and from which detailed information regarding the intimate interface between metals and organic molecules can be obtained, it is planned to reverse the interface and explore the plasmonic effects induced by metal clusters in a systematic approach. For this purpose well ordered, two-dimensional arrays of metallic nanostructures will be produced by nanosphere lithography (in cooperation with G6 (Albrecht)) with size, shape, and distance between the individual being adjustable. In dependence of these parameters and of the metal employed the optical response (Raman scattering, absorption, and emission) will be investigated when organic molecules are deposited onto the metallic nanostructures. The results anticipated will provide a deeper understanding of metal/organic interfaces. Moreover, the results have relevance for hybrid organic/inorganic optoelectronic devices such as photovoltaic cells.
Controlled growth of organic nanostructures
It was observed in own previous work that organic molecules such as DiMe-PTCDI form very well ordered organic nanowires on sulphur passivated GaAs surfaces which e.g. leads to an extremely anisotropic optical response. In addition, the formation of phthalocyanine nanotubes on SiO2 surfaces functionalized by Au nanodots was demonstrated [G7-1]. This project thus aims at the further exploration of organic nanostructure formation on suitably functionalized surfaces of semiconductors or insulators. The combination of nanostructures with their unique properties with the chemical versatility and functionalities of ❏-conjugated molecules is promising and novel multifunctional nanomaterials can emerge with potential applications in nanoelectronics, sensing, light–energy conversion and photonics. The own work will concentrate on growth using organic molecular beam deposition under ultra-high vacuum conditions and on characterization using in situ optical spectroscopies (photoluminescence, Raman, ellipsometry) with emphasis on the strong anisotropic response while structural characterization will be performed in cooperation with other IRTG members.
| [G6-1] | E. Barrena et al., ChemPhysChem 2008, 9, 1114 |