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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 29: Organic Electronics and Photovoltaics III
CPP 29.4: Vortrag
Mittwoch, 19. März 2025, 15:45–16:00, H38
Predicting the molecular arrangement of organic optoelectronic materials — •Alexey Gudovannyy1, Julia M. Schäfer2, Olga Gerdes2, Dirk Hildebrandt2, Gunter Mattersteig2, Martin Pfeiffer2, and Frank Ortmann1 — 1Department of Chemistry, TUM School of Natural Sciences, Technical University of Munich, 85748 Garching, Germany — 2Heliatek GmbH, 01139 Dresden, Germany
The morphology of the most promising molecular semiconductor materials remains highly challenging to predict from scratch. If possible, it would still require a lot of computational time and sometimes experimental data. The main obstacle here is the exponential growth with the number of molecular degrees of freedom for bulky side groups, which forces one to search on extremely complex energy surfaces. However, organic semiconductors mostly exhibit a limited set of structural motifs, primarily herringbone and two-dimensional brickwork patterns. Constraining the search to such dimensionally reduced packing possibilities simplifies the process while preserving 3D structural features. Here, we present a cost-efficient workflow for predicting thermodynamically stable 2D arrangements of molecular periodic associates, where only the molecular structural formula is required. We theoretically and experimentally investigated a set of known and newly crystallized compounds of evaporable flexible molecules with interesting optoelectronic properties, predicted their packing in two-dimensional layers, and compared them with experimentally resolved crystal structures, obtaining a very good agreement in the packing.
Keywords: Organic semiconductors; Crystal structure prediction; Molecular crystals; Low-dimensional materials