Fabrication of self-supporting antireflection-structured film by UV–NIL

• The self-supporting anti-reflection structure film fabrication method by UV–NIL was established.
• The release force from AR mold and the adhesive force between two substrates, i.e. PP film and resin were measured.
• The adhesive force was larger than the release force, preventing the adhesion of UV curable resin on the mold.
• We fabricated self-support film with less than 0.3% of reflectivity at the visible light wavelength without degradation.

Ultraviolet nanoimprint lithography (UV–NIL) is a powerful tool for the fabrication of films with antireflection (AR) structures (AR films), which are widely used in flat panel displays, mobile phone displays, solar cell surfaces, optical lenses, and so on. To fabricate the AR films, fabricated AR structures are replicated onto a UV photocurable polymer (resin) on top of a transparent poly (ethylene terepthalate) (PET) film. However, the interface between the AR structured polymer and the PET film causes high interface reflection. Therefore, a self-supporting AR polymer film that can eliminate interface reflection is required. In our previous research, polyvinyl alcohol (PVA) film was used as the intermediate film to obtain a self-supporting polymer film, but the durability of this self-supporting film was very low. In this study, instead of PVA film, we used polypropylene (PP) film as the intermediate film, which gives more stability to the self-supporting AR polymer film. The release and adhesive force of the self-supporting film were also evaluated. The fabricated self-supporting AR structure film exhibited 0.2–0.3% reflectivity in the spectrum range 430–950 nm.

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