Printable Organic-Inorganic Nanoscale Multilayer Gate Dielectrics for Thin-Film Transistors Enabled by a Polymeric Organic Interlayer

Here, a new approach to the layer-by-layer solution-processed fabrication of organic/inorganic hybrid self-assembled nanodielectrics (SANDs) is reported and it is demonstrated that these ultrathin gate dielectric films can be printed. The organic SAND component, named P-PAE, consists of polarizable π-electron phosphonic acid-based units bound to a polymeric backbone. Thus, the new polymeric SAND (PSAND) can be fabricated either by spin-coating or blade-coating in air, by alternating P-PAE, a capping reagent layer, and an ultrathin ZrOx layer. The new PSANDs thickness vary from 6 to 15 nm depending on the number of organic-ZrOx bilayers, exhibit tunable film thickness, well-defined nanostructures, large electrical capacitance (up to 558 nF cm⁻²), and good insulating properties (leakage current densities as low as 10⁻⁶ A cm⁻²). Organic thin-film transistors that are fabricated with representative p-/n-type organic molecular/polymeric semiconducting materials, function well at low voltages (<3.0 V). Furthermore, flexible TFTs fabricated with PSAND exhibit excellent mechanical flexibility and good stress stability, offering a promising route to low operating voltage flexible electronics. Finally, printable PSANDs are also demonstrated and afford TFTs with electrical properties comparable to those achieved with the spin-coated PSAND-based devices.