Freestanding TiN‐Au Vertically Aligned Nanocomposite Thin Films for Flexible Plasmonic Hybrid Metasurfaces

Abstract Nanoscale metamaterials based on transition metal nitrides, e.g., TiN, TaN, and HfN, have recently attracted significant attention for photonic devices owing to their unique optical and plasmonic properties and high‐temperature stability. With the very recent demonstration of nitride‐metal vertically aligned nanocomposite (VAN) thin films, enormous potentials are presented in these complex hybrid metamaterials with well controlled light‐matter interactions. Most of the epitaxial VAN growth requires a lattice‐matched single‐crystalline oxide substrate and high deposition temperatures, which significantly limit the device integration potentials of VANs. In this work, a freestanding TiN‐Au VAN is synthesized on a water‐soluble Sr 3 Al 2 O 6 buffer layer. A very thin TiN buffer layer is incorporated to improve the overall VAN growth quality. The microstructure and optical properties of the VAN samples are compared before and after transfer to evaluate the transfer properties. The results suggest that minimal impacts on film morphology and properties are found in the transferred samples. This study demonstrates the potential to obtain high‐quality freestanding TiN‐Au VAN thin film for flexible and transferable hybrid metamaterials and metasurfaces for plasmonics and integrated photonic devices.