Quasi‐2D Morphologies of a Non‐Fullerene Acceptor Y6 by Interfacial Assembly via Langmuir–Schaefer Technique
Abstract
Abstract Supramolecular organization governs the structure and optoelectronic properties of organic thin films. This study shows that films based on the non‐fullerene acceptor Y6 can be precisely structured via assembly at the air‐water interface. Theoretical cross‐sectional areas, Langmuir isotherms, and Brewster angle microscopy reveal that Y6, despite its complex structure, is sufficiently amphiphilic to form well‐defined 2D layers. Mechanical annealing through repeated compression‐expansion cycles systematically improves structural uniformity, as evidenced by narrower in situ detected fluorescence spectra, while simultaneously shifting the maximum of the compressional modulus toward denser packing. Compared to spin‐cast films, Langmuir–Schaefer (LS) layers exhibit a significantly reduced Stokes shift, suggesting less reorganization after photoexcitation and thus a higher supramolecular order. Organic thin‐film transistors (OTFTs) fabricated using the LS technique achieve mobilities comparable to those of spin‐cast films, despite being substantially thinner (≤ 3 nm, determined by atomic force microscopy), thus requiring considerably less material. Notably, Y6‐LS OTFTs outperform previously reported polymer‐based LS‐OTFTs by one order of magnitude in charge carrier mobility. This work highlights the potential of interfacial assembly for thin film fabrication and underscores the advantages of mechanical annealing and in situ spectroscopy to enhance the performance of organic optoelectronic devices.
Article Details
Authors (17)
Yisak Tsegazab Gerase
Institute of Physical Chemistry Friedrich Schiller University Jena Helmholtzweg 4 07743 Jena Germany
Anna Elmanova
Institute of Physical Chemistry Friedrich Schiller University Jena Helmholtzweg 4 07743 Jena Germany
Sarah Jasmin Finkelmeyer
Leibniz Institute of Photonic Technology (IPHT) Albert‐Einstein‐Str. 9 07745 Jena Germany
Andrea Dellith
Leibniz Institute of Photonic Technology (IPHT) Albert‐Einstein‐Str. 9 07745 Jena Germany
Jan Dellith
Leibniz Institute of Photonic Technology (IPHT) Albert‐Einstein‐Str. 9 07745 Jena Germany
Julien Guthmuller
Institute of Physics and Applied Computer Science, Faculty of Applied Physics and Mathematics Gdańsk University of Technology Narutowicza 11/12 Gdańsk 80233 Poland
Oleg Ryabchykov
Leibniz Institute of Photonic Technology (IPHT) Albert‐Einstein‐Str. 9 07745 Jena Germany
Thomas Bocklitz
Filippo Giovanni Fabozzi
Department of Chemistry & Center for the Science of Materials Berlin, Humboldt-Universität zu Berlin, Brook-Taylor-Strasse 2, Berlin 12489, Germany
Nikolai Severin
Department of Physics and Center for the Science of Materials Berlin Humboldt‐Universität zu Berlin 12489 Berlin Germany
Stefan Hecht
Department of Chemistry and Center for the Science of Materials Berlin, Humboldt-Universität zu Berlin, Berlin, Germany.
Lukas Renn
1st Institute of Physics, Faculty of Physics Georg‐August‐University Göttingen Friedrich‐Hund‐Platz 1 37077 Göttingen Germany
James Borchert
1st Institute of Physics, Faculty of Physics Georg‐August‐University Göttingen Friedrich‐Hund‐Platz 1 37077 Göttingen Germany
R. Thomas Weitz
Johannes Müller
Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung
Christoph T. Koch
Martin Presselt
Institute of Physical Chemistry Friedrich Schiller University Jena Helmholtzweg 4 07743 Jena Germany