Ultralow contact resistance in organic transistors via orbital hybridization.

Zeng, Junpeng; He, Daowei; Qiao, Jingsi; Li, Yating; Sun, Li; Li, Weisheng; Xie, Jiacheng; Gao, Si et al. · Nat Commun · 2023

basic_science · Level V

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Abstract

Organic field-effect transistors (OFETs) are of interest in unconventional form of electronics. However, high-performance OFETs are currently contact-limited, which represent a major challenge toward operation in the gigahertz regime. Here, we realize ultralow total contact resistance (R<sub>c</sub>) down to 14.0 Ω ∙ cm in C<sub>10</sub>-DNTT OFETs by using transferred platinum (Pt) as contact. We observe evidence of Pt-catalyzed dehydrogenation of side alkyl chains which effectively reduces the metal-semiconductor van der Waals gap and promotes orbital hybridization. We report the ultrahigh performance OFETs, including hole mobility of 18 cm<sup>2</sup> V<sup>-1</sup> s<sup>-1</sup>, saturation current of 28.8 μA/μm, subthreshold swing of 60 mV/dec, and intrinsic cutoff frequency of 0.36 GHz. We further develop resist-free transfer and patterning strategies to fabricate large-area OFET arrays, showing 100% yield and excellent variability in the transistor metrics. As alkyl chains widely exist in conjugated molecules and polymers, our strategy can potentially enhance the performance of a broad range of organic optoelectronic devices.