Large-area all-dielectric metasurface fabricated by an anodized aluminum oxide template

Transmissive metasurfaces formed by high-index dielectric materials have received great attention due to its potential in holograms, deflectors, beam converters, and flat lenses. However, a key challenge of all-dielectric metasurfaces is the limited scale and high cost in fabrication, such as electron beam lithography (EBL) and focused ion beam (FIB) lithography. In this paper, for the first time to our knowledge, an anodized aluminum oxide (AAO) template is combined with titanium dioxide (TiO₂) metasurface fabrication with advantages of large area (>2cm²) and low cost. Using the ordered anodized aluminum oxide (AAO) as an evaporation mask, a TiO₂ nanocylinder array is deposited through the AAO mask onto the SiO₂ substrate. Electric and magnetic dipole resonances of TiO₂ metasurface appear in the visible spectrum. Furthermore, we demonstrate the interaction of the CsPbBr_1.5I_1.5 quantum dot (QD) emission with magnetic dipole (MD) resonance of TiO₂ metasurface. Our results reveal that the metasurface exhibits remarkable photoluminescence (PL) enhancement of 25%. Up to now, a TiO₂ metasurface with 2.25-cm²-large area using AAO template method has never been attempted. Different from the metasurfaces fabricated by FIB and EBL, our method offers great ease for large-area metasurface fabrication, which is convenient for metasurface researchers and avoids costly facilities.