Periodic array of polyelectrolyte-gated organic transistors from electrospun poly(3-hexylthiophene) nanofibers.

High-performance organic field-effect transistors (OFETs) based on polyelectrolyte gate dielectric and electrospun poly(3-hexylthiophene) (P3HT) nanofibers were fabricated on a flexible polymer substrate. The use of UV-crosslinked hydrogel including ionic liquids for the insulating layer enabled fast and large-area fabrication of transistor arrays. The P3HT nanofibers were directly deposited on the methacrylated polymer substrate. During UV irradiation through a patterned mask, the methacrylate groups formed covalent bonds with the patterned polyelectrolyte dielectric layer, which provides mechanical stability to the devices. The OFETs operate at voltages of less than 2 V. The average field-effect mobility and on/off ratio were approximately 2 cm(2)/(Vs) and 10(5), respectively.

Large-area fabrication of patterned ZnO-nanowire arrays using light stamping lithography.

We demonstrate selective adsorption and alignment of ZnO nanowires on patterned poly(dimethylsiloxane) (PDMS) thin layers with (aminopropyl)siloxane self-assembled monolayers (SAMs). Light stamping lithography (LSL) was used to prepare patterned PDMS thin layers as neutral passivation regions on Si substrates. (3-Aminopropyl)triethoxysilane-based SAMs were selectively formed only on regions exposing the silanol groups of the Si substrates. The patterned positively charged amino groups define and direct the selective adsorption of ZnO nanowires with negative surface charges in the protic solvent. This procedure can be adopted in automated printing machines that generate patterned ZnO-nanowire arrays on large-area substrates. To demonstrate its usefulness, the LSL method was applied to prepare ZnO-nanowire transistor arrays on 4-in. Si wafers.