title: Solution-Processable BODIPY-Based Small Molecules for Semiconducting Microfibers in Organic Thin-Film Transistors.
abstract: Electron-deficient π-conjugated small molecules can function as electron-transporting semiconductors in various optoelectronic applications. Despite their unique structural, optical, and electronic properties, the development of BODIPY-based organic semiconductors has lagged behind that of other π-deficient units. Here, we report the design and synthesis of two novel solution-proccessable BODIPY-based small molecules (BDY-3T-BDY and BDY-4T-BDY) for organic thin-film transistors (OTFTs). The new semiconductors were fully characterized by (1)H/(13)C NMR, mass spectrometry, cyclic voltammetry, UV-vis spectroscopy, photoluminescence, differential scanning calorimetry, and thermogravimetric analysis. The single-crystal X-ray diffraction (XRD) characterization of a key intermediate reveals crucial structural properties. Solution-sheared top-contact/bottom-gate OTFTs exhibited electron mobilities up to 0.01 cm(2)/V·s and current on/off ratios of >10(8). Film microstructural and morphological characterizations indicate the formation of relatively long (∼0.1 mm) and micrometer-sized (1-2 μm) crystalline fibers for BDY-4T-BDY-based films along the shearing direction. Fiber-alignment-induced charge-transport anisotropy (μ∥/μ⊥ ≈ 10) was observed, and higher mobilities were achieved when the microfibers were aligned along the conduction channel, which allows for efficient long-range charge-transport between source and drain electrodes. These OTFT performances are the highest reported to date for a BODIPY-based molecular semiconductor, and demonstrate that BODIPY is a promising building block for enabling solution-processed, electron-transporting semiconductor films.
authors.affiliation: Department of Materials Science and Nanotechnology Engineering, Abdullah Gül University , Kayseri 38080, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Ozdemir
authors.affiliation: Department of Chemical and Biomolecular Engineering, Sogang University , Mapo-gu, Seoul 121-742, Korea.
authors.forename: Donghee
authors.initials: D
authors.lastname: Choi
authors.affiliation: Department of Chemical and Biomolecular Engineering, Sogang University , Mapo-gu, Seoul 121-742, Korea.
authors.forename: Guhyun
authors.initials: G
authors.lastname: Kwon
authors.affiliation: Department of Chemistry, Gebze Technical University , Gebze 41400, Turkey.
authors.forename: Yunus
authors.initials: Y
authors.lastname: Zorlu
authors.affiliation: Department of Chemistry, Gebze Technical University , Gebze 41400, Turkey.
authors.forename: Bunyemin
authors.initials: B
authors.lastname: Cosut
authors.affiliation: Department of Chemical and Biomolecular Engineering, Sogang University , Mapo-gu, Seoul 121-742, Korea.
authors.forename: Hyekyoung
authors.initials: H
authors.lastname: Kim
authors.affiliation: Polyera Corporation , 8045 Lamon Avenue, Skokie, Illinios 60077, United States.|Center of Excellence for Advanced Materials Research (CEAMR), King Abdulaziz University , Jeddah 21589, Saudi Arabia.
authors.forename: Antonio
authors.initials: A
authors.lastname: Facchetti
authors.affiliation: Department of Chemical and Biomolecular Engineering, Sogang University , Mapo-gu, Seoul 121-742, Korea.
authors.forename: Choongik
authors.initials: C
authors.lastname: Kim
authors.affiliation: Department of Materials Science and Nanotechnology Engineering, Abdullah Gül University , Kayseri 38080, Turkey.
authors.forename: Hakan
authors.initials: H
authors.lastname: Usta
keywords: BODIPY; n-channel semiconductor; organic thin-film transistor; small molecule-based microfiber