Staggered top-gate PDIF-CN2 N-type thin film transistors on flexible plastic substrates

In this work, staggered top-gate n-type organic thin film transistors (OTFTs) with evaporated PDIF-CN2 semi-conducting layers, spin-coated Cytop (TM) dielectric barriers and channel lengths ranging from 100 to 2 mu m were fabricated on polyethylene-naphtalate (PEN) substrates. Hexamethyldisilazane (HMDS) treatment of the PEN surface was successfully tested as an effective strategy to achieve flexible devices with improved electrical response. Following this approach, maximum field-effect mobility (mu(FE)) values exceeding 0.4 cm(2)/V.s were observed in air. Moreover, the self-encapsulating features of the investigated top-gate configuration, employing the highly hydrophobic Cytop (TM) dielectric films, allowed getting considerable performances in terms of un-sensitivity to hysteresis and bias stress phenomena.