Hawly, T. / Johnson, M. / Zhao, B. / Wu, M. / Späth, A. / Streller, F. / Jäkel, H.N. / Halik, M. / Spiecker, E. / Watts, B. / Nefedov, A. / Fink, R. H. (2022)

ACS Appl. Electron. Mater., 2022, 4, 12, 5914–5921, doi.org/10.1021/acsaelm.2c01095

Abstract

Two-dimensionally (2D) extended thin films of p-type organic semiconductor C13-BTBT (BTBT = [1]benzothieno[3,2-b]-[1]benzothiophene) were fabricated via self-controlled growth at the liquid–liquid interface. Depicting a compound class originally developed for further functionalization and subsequent realization of self-assembled monolayers (SAMs), the potent BTBT core unit commonly excels in high-quality structure formation as well as charge-transport characteristics. Utilizing a manifold spectromicroscopic toolbox, we observe extraordinarily crystalline C13-BTBT films with an upright standing configuration of the backbone unit accounting for superior intermolecular orbital overlap. The well-defined morphology and internal structure of the film are being underpinned by charge-transport parameters that are in the range of comparable organic electronic devices based on bisubstituted BTBT films from the same processing technique. The inherently favorable membrane-like bilayer molecular arrangement is confirmed by unambiguous representation of the unit cell as derived from electron tomography.

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