A2 - Controlled formation of molecular stacks
Principle Investigator: Prof. Sigurd Höger
This project will investigate the process of polycyclic/heterocyclic aromatic hydrocarbon (PAHs) aggregation. Our approach relies on the synthesis of PAH-substituted polygonal arylene-alkynylene macrocycles that self-assemble into periodic patterns at the solid/liquid interface on primary templates like HOPG or graphene/Cu(111) in a predictable manner. This will enable us to study the impact of disorder as a function of the stack thickness, since a single defect (e.g. misplaced molecules within a molecular stack), leads to a charge carrier scattering site. STM/STS/cAFM measurements will give insights into how these systems form, how defects on the substrate influence nucleation and growth, and how defects in the organic layer can be addressed.
This will be a combined synthetic (organic synthesis, Sigurd Höger) and analytic (STM, Stefan-S. Jester) project.
 T. J. Keller, J. Bahr, K. Gratzfeld, N. Schönfelder, M. A. Majewski, M. Stępień, S. Höger, S.-S. Jester, Beilstein J. Org. Chem. 15, 1848 (2019).
 M. Hündgen, K. A. Weis, S. Höger, S.-S. Jester, Chem. Commun. 54, 10558 (2018).
 P. Wilhelm, J. Vogelsang, G. Poluektov, N. Schönfelder, T. J. Keller, S.-S. Jester, S. Höger, J. M. Lupton, Angew. Chem. Int. Ed. 56, 1234 (2017).
 R. May, S.-S. Jester, S. Höger, J. Am. Chem. Soc. 136, 16732 (2014).