Moiré Lattice of Twisted Bilayer Graphene as Template for Non-Covalent Functionalization

Recently, a team from the Chair of Experimental Physics, together with colleagues from the Department of Chemistry, developed a novel method to achieve spatially controlled non-covalent functionalization of twisted bilayer graphene (tBLG) by using its moiré lattice as a template for the functionalization. tBLG is non-covalently functionalized with a molecule known as HATCN (1,4,5,8,9,11-hexaazatriphenylenehexacarbonitrile). Spatial variations in the degree of functionalization depending on the twist angle of tBLG were identified by Raman measurements. Areas with smaller twist angles exhibit higher HATCN adsorption than areas with larger twist angles.

The study suggests that HATCN molecules preferentially adsorb on regions of tBLG with local AB-stacking order, avoiding AA-stacked areas, and form an overall ABA-stacking configuration. This insight is further validated through density functional theory (DFT) calculations.

This work highlights the importance of the moiré lattice in influencing the functionalization of tBLG and potentially other 2D materials. It offers a new pathway for precise nanoscale material engineering, where by controlling the twist angle one can design materials with locally varying chemical or physical properties.

For more information, see the publication in Angewandte Chemie:

T. Dierke, S. Wolff, R. Gillen, J. Eisenkolb, T. Nagel, S. Maier, M. Kivala, F. Hauke, A. Hirsch, and J. Maultzsch.

Angewandte Chemie International Edition 64.2 (2025). e202414593.