A Self-Assembly Method for Tunable and Scalable Nano-Stamps: A Versatile Approach for Imprinting Nanostructures

In nanoimprint lithography (NIL), the imprinting stamp's fabrication is still a significant cost factor among the consumables. Bottom-up lithography approaches based on a phase-separation of polymer blends can provide a cost-effective route for fabricating these stamps. Today's polymers used to prepare phase-separated nanostructures (PSN), however, exhibit low glass transition temperatures. As a result, the PSN are prone to in-plane stamp distortions in the presence of high imprinting pressure and temperature, limiting their practical relevance for NIL. Here, the realization of mechanically and thermally stable PSN-based imprinting stamps for NIL systems via a phase-separation of a homopolymer/inorganic-organic hybrid polymer blend is reported. It is demonstrated that these imprinting stamps are easily tunable and scalable by adjusting the formulation of homopolymer/hybrid polymer mixture and deposition conditions. Feature sizes in PSN ranging from a few mu m down to 100 nm are achieved through an interplay of these factors. As demonstrations of the envisioned applications, the developed imprinting stamps are integrated into a roll-to-roll NIL system for patterning a polystyrene thin-film. Moreover, light management is demonstrated by nanopatterning of a perovskite semiconductor in plate-to-plate process. The nanopatterned perovskite film achieves an integrated absorption and a photoluminescence emission peak increase of 7%(rel) and 121%(rel), respectively.