title: Solvent-Free Processable and Photo-Patternable Hybrid Gate Dielectric for Flexible Top-Gate Organic Field-Effect Transistors.
abstract: We report a novel solvent-free and direct photopatternable poly[(mercaptopropyl)methyl-siloxane] (PMMS) hybrid dielectric for flexible top-gate organic field-effect transistors (OFETs) utilizing a photoactivated thiol-ene reaction under UV irradiation of 254 nm to induce cross-linking, even in air and at low temperatures. In particular, a solvent-free PMMS-f dielectric film, for which an optimal cross-linking density is shown by a well-organized molar ratio between thiol and vinyl in the thiol-ene reaction, exhibited a high dielectric constant (5.4 @ 100 Hz) and a low leakage current (<1 nA mm-2@ 2 MV cm-1). The excellent dielectric characteristics of the solvent-free PMMS-hybrid dielectrics, along with their other unique characteristics of a direct photopatternability for which UV-nanoimprint lithography is used and a high surface energy of 45.6 mJ m-2, allowed the successful application of the dielectrics to flexible solvent-free top-gate OFETs with a high reliability against the radius of curvature (9.5, 7.0, and 5.5 mm) and repetitive bending cycles at the radius of curvature of 5.5 mm. This will eventually enable the proposed dielectric design to be used in a variety of applications such as flexible displays and soft organic sensors including chemical and tactile capability.
authors.affiliation: Department of Organic Materials and Fiber Engineering, Soongsil University , 369 Sangdo-Ro, Dongjak-Gu, Seoul 06978, Korea.|Department of Information Communication, Materials, and Chemistry Convergence Technology (BK-21 plus), Soongsil University , 369 Sangdo-Ro, Dongjak-Gu, Seoul 06978, Korea.
authors.forename: Jun Seon
authors.initials: JS
authors.lastname: Kwon
authors.affiliation: Department of Organic Materials and Fiber Engineering, Soongsil University , 369 Sangdo-Ro, Dongjak-Gu, Seoul 06978, Korea.|Department of Information Communication, Materials, and Chemistry Convergence Technology (BK-21 plus), Soongsil University , 369 Sangdo-Ro, Dongjak-Gu, Seoul 06978, Korea.
authors.forename: Han Wool
authors.initials: HW
authors.lastname: Park
authors.affiliation: Department of Organic Materials and Fiber Engineering, Soongsil University , 369 Sangdo-Ro, Dongjak-Gu, Seoul 06978, Korea.|Department of Information Communication, Materials, and Chemistry Convergence Technology (BK-21 plus), Soongsil University , 369 Sangdo-Ro, Dongjak-Gu, Seoul 06978, Korea.
authors.forename: Do Hwan
authors.identifier: http://orcid.org/0000-0003-3003-8125
authors.initials: DH
authors.lastname: Kim
authors.affiliation: Department of Organic Materials and Fiber Engineering, Soongsil University , 369 Sangdo-Ro, Dongjak-Gu, Seoul 06978, Korea.|Department of Information Communication, Materials, and Chemistry Convergence Technology (BK-21 plus), Soongsil University , 369 Sangdo-Ro, Dongjak-Gu, Seoul 06978, Korea.
authors.forename: Young-Je
authors.initials: YJ
authors.lastname: Kwark
keywords: flexible top-gate OFETs; hybrid dielectrics; photopatternable; polysiloxane; solvent-free process