title: One-Step Interface Engineering for All-Inkjet-Printed, All-Organic Components in Transparent, Flexible Transistors and Inverters: Polymer Binding.
abstract: We report a one-step interface engineering methodology which can be used on both polymer electrodes and gate dielectric for all-inkjet-printed, flexible, transparent organic thin-film transistors (OTFTs) and inverters. Dimethylchlorosilane-terminated polystyrene (PS) was introduced as a surface modifier to cured poly(4-vinylphenol) dielectric and poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) electrodes without any pretreatment. On the untreated and PS interlayer-treated dielectric and electrode surfaces, 6,13-bis(triisopropylsilylethynyl)pentacene was printed to fabricate OTFTs and inverters. With the benefit of the PS interlayer, the electrical properties of the OTFTs on a flexible plastic substrate were significantly improved, as shown by a field-effect mobility (μFET) of 0.27 cm2V-1s-1and an on/off current ratio (Ion/Ioff) of greater than 106. In contrast, the untreated systems showed a low μFETof less than 0.02 cm2V-1s-1and Ion/Ioff∼ 104. Additionally, the all-inkjet-printed inverters based on the PS-modified surfaces exhibited a voltage gain of 7.17 V V-1. The all-organic-based TFTs and inverters, including deformable and transparent PEDOT:PSS electrodes with a sheet resistance of 160-250 Ω sq-1, exhibited a light transmittance of higher than 70% (at wavelength of 550 nm). Specifically, there was no significant degradation in the electrical performance of the interface engineering-assisted system after 1000 bending cycles at a radius of 5 mm.
authors.affiliation: Department of Electrical and Computer Engineering (ECE), Inter-university Semiconductor Research Center (ISRC), Seoul National University , Seoul 08826, Republic of Korea.
authors.forename: Jewook
authors.initials: J
authors.lastname: Ha
authors.affiliation: Department of Physics and Astronomy, Seoul National University , Seoul 08826, Republic of Korea.
authors.forename: Seungjun
authors.initials: S
authors.lastname: Chung
authors.affiliation: Department of Applied Organic Materials Engineering, Inha University , Incheon 22212, Republic of Korea.
authors.forename: Mingyuan
authors.initials: M
authors.lastname: Pei
authors.affiliation: Department of Chemical Engineering, Pohang University of Science and Technology , Pohang 37673, Republic of Korea.
authors.forename: Kilwon
authors.identifier: http://orcid.org/0000-0003-0321-3629
authors.initials: K
authors.lastname: Cho
authors.affiliation: Department of Applied Organic Materials Engineering, Inha University , Incheon 22212, Republic of Korea.
authors.forename: Hoichang
authors.identifier: http://orcid.org/0000-0003-0585-8527
authors.initials: H
authors.lastname: Yang
authors.affiliation: Department of Electrical and Computer Engineering (ECE), Inter-university Semiconductor Research Center (ISRC), Seoul National University , Seoul 08826, Republic of Korea.
authors.forename: Yongtaek
authors.initials: Y
authors.lastname: Hong
keywords: inkjet printing; interface engineering; organic thin-film transistors; polymer binding; polymer electrodes; transparent thin-film transistors