The Impact of Molecular p-Doping on Charge Transport in High-Mobility Small-Molecule/Polymer Blend Organic Transistors

Alexandra Paterson, Yen-Hung Lin, Alexander D. Mottram, Zhuping Fei, Muhammad Rizwan Niazi, Ahmad R. Kirmani, Aram Amassian, Olga Solomeshch, Nir Tessler, Martin Heeney, Thomas D. Anthopoulos

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49 Scopus citations


Molecular doping is a powerful tool with the potential to resolve many of the issues currently preventing organic thin-film transistor (OTFT) commercialization. However, the addition of dopant molecules into organic semiconductors often disrupts the host lattice, introducing defects and harming electrical transport. New dopant-based systems that overcome practical utilization issues, while still reaping the electrical performance benefits, would therefore be extremely valuable. Here, the impact of p-doping on the charge transport in blends consisting of the small-molecule 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT), the polymer indacenodithiophene-benzothiadiazole (C16IDT-BT), and the molecular dopant C60F48 is investigated. Electrical field-effect measurements indicate that p-doping not only enhances the average saturation mobility from 1.4 to 7.8 cm2 V−1 s−1 over 50 devices (maximum values from around 4 to 13 cm2 V−1 s−1), but also improves bias–stress stability, contact resistance, threshold voltage, and the overall device-to-device performance variation. Importantly, materials characterization using X-ray diffraction, X-ray photoemission spectroscopy, and ultraviolet photoemission spectroscopy, combined with charge transport modeling, reveal that effective doping is achieved without perturbing the microstructure of the polycrystalline semiconductor film. This work highlights the remarkable potential of ternary organic blends as a simple platform for OTFTs to achieve all the benefits of doping, with none of the drawbacks.
Original languageEnglish (US)
Pages (from-to)1700464
JournalAdvanced Electronic Materials
Issue number10
StatePublished - Dec 27 2017

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