Metal-organic hybrid structures offer unique possibilities for application in already existing devices, such as photo-detectors or organic light-emitting diodes (OLEDs), as well as in novel photonic architectures. Furthermore, the coupling between the electronic excitations of a molecular thin film and the local plasmonic resonances of a metallic nanopattern in close proximity can tune the optical properties of the organic layer or even generate new plasmon-polaritonic states, also called plexcitons. Their coupling strength relates to the inner product of the transition dipole moment of the excitonic state and the electrical field of the localized surface plasmon. Consequently, even a spatially dependent coupling can occur, in case, the transition dipole moments are aligned anisotropically and can constitute the platform for novel photonic devices with topological characteristics.
Implementing the concept of coupled metal-organic hybrid structures we demonstrated a strong enhancement in light out-coupling of an organic thin film deposited on top of a hexagonal silver nanopattern . For this purpose, we utilized the Shadow Nanosphere Lithography (SNL), a versatile and low-cost-large-area technique to manufacture long ranged ordered nanoarrays of metals, organics or hybrid-compounds. Varying the materials constituting the nanoarray, their angle of deposition during growth or post-thermally treating the latter, the resulting optical characteristics, including the energetic positions of the plasmon-polaritonic states or their coupling, can be tuned over a wide range. This allows not only for a comprehensive study of the underlying interaction mechanisms but also for an implementation in various device structures to improve their performance or multi-functionality.
If you are interested in a specific topic of our research or are looking for a bachelor or master thesis in this field feel free to contact Maximilian Rödel or for general questions Prof. Jens Pflaum.
 Hybrid metal-organic nanocavity arrays for efficient light out-coupling
Kolb V, and Pflaum J (2017). Opt. Express, 25, 6678-6689. [DOI]