Transferable, Polymer-Insulated Nanomesh Electrode for High-Current-Density Organic Nanowire Transistors and Gate-Tunable Light Emission

Harnessing the full potential of a gate-modulated planar junction to maximize its on-state current density presents fundamental challenges in nanotechnology, particularly for semiconducting nanowires due to their random orientations and partial coverage. Herein, we developed a straightforward method by combining dual self-alignment with nanosphere lithography to fabricate a nanomesh electrode conformally encapsulated by a polymeric insulator. This honeycomb-like nanostructured electrode is designed to form a vertically stacked electrode pair with the (semi)conducting materials precisely filling its pores. For a 200 μm × 200 μm transistor area, the channel width-to-length ratio is expected to approach 7.6 × 105, effectively achieving a patterning resolution of 100–200 nm without requiring expensive nanofabrication tools such as photolithography and electron-beam lithography. The resulting field-effect transistors using supramolecular poly(3-hexylthiophene) nanowires as the channel active layer exhibited a maximum on-state current density exceeding 2000 mA cm–2. Additionally, the integration of a light-emitting junction by vacuum-depositing tris(8-hydroxyquinolinato) aluminum atop results in gate-modulated uniform luminance up to 1000 cd m–2. This approach paves the way for highly integrated applications, such as micro-LED pixel driving, by maximizing the transistor current density based on a given metal–insulator-semiconductor junction.