Nanoscale Morphology of the PTCDI-C13/PMMA Interface: An Integrated Molecular Dynamics and Atomic Force Microscopy Approach

The morphology of molecular aggregates at interfaces impacts strongly on the functional properties of nanoscale systems for electronic and optoelectronic applications. The packing of organic materials on surfaces, in turn, depends on several factors, including the nature and structure of the substrate, the fabrication conditions, and processing. In this work, we perform an integrated computational/experimental study to unravel the details of the molecular aggregation morphology at the interface between two organic materials. Namely, we address the morphology of aggregates of N,N′-ditridecylperylene-3,4,9,10-tetracarboxylic diimide (PTCDI-C13), a prototypical n-type organic semiconductor at the interface with poly-methyl metacrylate (PMMA), an organic polymer commonly used as a dielectric layer in devices. The integration between molecular dynamics simulations and atomic force microscopy experiments elucidates the critical role of growth and post-processing conditions in the formation of the interface structure.