Promotionsvortrag Physik: Spatially controlled functionalization of graphene and twisted bilayer graphene

Ankündigung des Promotionsvortrags von Herrn Tobias Dierke:

„Spatially controlled functionalization of graphene and twisted bilayer graphene “

Graphene is a single layer of carbon atoms arranged in a hexagonal lattice, known for its excep-tional electrical, mechanical, and thermal properties. Its high conductivity, strength, and flexibility make it a promising material for many applications. However, pristine graphene is chemically inert and lacks a band gap, limiting its use in certain devices. Applying a chemical functionalization—modifying its surface with chemical groups or molecules—enables tuning of its chemical, electrical and optical properties, opening up new possibilities in sensors, catalysis, and nanoelectronics.

In this talk, I present two functionalized graphene systems. First, I discuss a covalent functionali-zation of graphene deposited on hexagonal boron nitride and show that we can spatially control the degree of functionalization by patterning the underlying substrate. Further, I present twisted bilayer graphene (tBLG), focusing on the distinct features that emerge in the Raman spectra as signature of the twist angle, as well as variations in twist angle that are observed within a tBLG flake. Finally, I discuss examples of tBLG that have been non-covalently functionalized. The mol-ecule adsorption on the graphene surface appears to favor specific sites within the moiré lattice formed by the twisted layers. By combining Raman spectroscopy mapping with density functional theory simulations, I demonstrate that the moiré lattice of tBLG can serve as an effective template for non-covalent functionalization.

(Vortrag auf Englisch)

Dem Vortrag schließt sich eine Diskussion von 15 Minuten an. Vortrag und Diskussion sind öffentlich. Diesen Verfahrensteilen folgt ein nicht öffentliches Rigorosum von 45 Minuten.