Adhesion layer engineering for zero reflection optical metasurfaces

Gold-based zero-reflection metasurfaces hold great promise for advanced optical applications. However, their practical implementation is limited by the need for adhesion layers, which typically introduce significant optical losses. Here, we present a systematic investigation of adhesion layer materials and identify aluminum as an optimal solution that preserves optical performance while ensuring mechanical stability. We show that ultrathin aluminum layers, together with their native oxide, maintain resonance quality and near-field enhancement comparable to adhesion-free structures. Its advanced optical properties are further demonstrated through the detection of protein monolayers, with the metasurfaces maintaining structural integrity under harsh conditions. Additionally, we investigate the influence of the percolation threshold and native oxide formation on Al, ITO and Ti adhesion layers, elucidating their impact on the metasurface’s optical response. These findings establish adhesion layer engineering as a critical design parameter for metasurface optimization and offer a practical route toward robust, high-performance integration of zero-reflection metasurfaces into real-world devices. Gold-based zero-reflection metasurfaces are promising for optical applications but face challenges due to adhesion layer-induced optical losses. Here, the authors identify aluminum as an optimal adhesion layer, preserving optical performance and mechanical stability, and demonstrate its efficacy in protein detection, highlighting a path for integrating metasurfaces into practical devices.