Supramolecular Order of Solution-Processed Perylenediimide Thin Films: High-Performance Small-Channel n-Type Organic Transistors

N,N′‐1H,1H‐perfluorobutyl dicyanoperylenecarboxydiimide (PDIF‐CN2), a soluble and air stable n‐type molecule, undergoes significant reorganization upon thermal annealing after solution deposition on several substrates with different surface energies. Interestingly, this system exhibits an exceptional edge‐on orientation regardless of the substrate chemistry. This preferential orientation is rationalized in terms of strong intermolecular interactions between the PDIF‐CN2 molecules. The presence of a pronounced π–π stacking is confirmed by combining near‐edge X‐ray absorption fine structure spectroscopy (NEXAFS), dynamic scanning force microscopy (SFM) and surface energy measurements. The remarkable charge carrier mobility measured in field‐effect transistors, using both bottom‐ and top‐contact (bottom‐gate) configurations, underlines the importance of strong intermolecular interactions for the realization of high performing devices. The exceptional supramolecular order of solution‐processed perylenediimide thin films is demonstrated. Investigation of their self‐assembly on different surfaces upon annealing reveals long‐range molecular packing and orientation comparable to those of highly oriented vapor‐deposited small molecules. By studying charge transport and injection properties of the resulting field‐effect transistors, fundamental correlations between molecular orientation and device performance are highlighted.