1 research outputs found
Solvent-Free Processable and Photo-Patternable Hybrid Gate Dielectric for Flexible Top-Gate Organic Field-Effect Transistors
We
report a novel solvent-free and direct photopatternable polyÂ[(mercaptopropyl)Âmethyl-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<sup>–2</sup> @ 2 MV cm<sup>–1</sup>). 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<sup>–2</sup>, 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