Perpendicular crossing chains enable high mobility in a noncrystalline conjugated polymer.

Coker, Jack F; Moro, Stefania; Gertsen, Anders S; Shi, Xingyuan; Pearce, Drew; van der Schelling, Martin P; Xu, Yucheng; Zhang, Weimin et al. · Proc Natl Acad Sci U S A · 2024

basic_science · Level V

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Abstract

The nature of interchain π-system contacts, and their relationship to hole transport, are elucidated for the high-mobility, noncrystalline conjugated polymer C16-IDTBT by the application of scanning tunneling microscopy, molecular dynamics, and quantum chemical calculations. The microstructure is shown to favor an unusual packing motif in which paired chains cross-over one another at near-perpendicular angles. By linking to mesoscale microstructural features, revealed by coarse-grained molecular dynamics and previous studies, and performing simulations of charge transport, it is demonstrated that the high mobility of C16-IDTBT can be explained by the promotion of a highly interconnected transport network, stemming from the adoption of perpendicular contacts at the nanoscale, in combination with fast intrachain transport.