Zhang Yizhi, Zhang Di, Liu Juncheng, Lu Ping, Deitz Julia, Shen Jianan, He Zihao, Zhang Xinghang, Wang Haiyan
School of Materials Engineering, Purdue University, West Lafayette, 47907, USA.
Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
Nanoscale. 2022 Aug 25;14(33):11979-11987. doi: 10.1039/d2nr03104c.
Oxide-metal-based hybrid materials have gained great research interest in recent years owing to their potential for multifunctionality, property coupling, and tunability. Specifically, oxide-metal hybrid materials in a vertically aligned nanocomposite (VAN) form could produce pronounced anisotropic physical properties, , hyperbolic optical properties. Herein, self-assembled HfO-Au nanocomposites with ultra-fine vertically aligned Au nanopillars (as fine as 3 nm in diameter) embedded in a HfO matrix were fabricated using a one-step self-assembly process. The film crystallinity and pillar uniformity can be obviously improved by adding an ultra-thin TiN-Au buffer layer during the growth. The HfO-Au hybrid VAN films show an obvious plasmonic resonance at 480 nm, which is much lower than the typical plasmonic resonance wavelength of Au nanostructures, and is attributed to the well-aligned ultra-fine Au nanopillars. Coupled with the broad hyperbolic dispersion ranging from 1050 nm to 1800 nm in wavelength, and unique dielectric HfO, this nanoscale hybrid plasmonic metamaterial presents strong potential for the design of future integrated optical and electronic switching devices.
近年来，基于氧化物-金属的混合材料因其多功能性、性能耦合和可调性潜力而受到了极大的研究关注。具体而言，垂直排列的纳米复合材料（VAN）形式的氧化物-金属混合材料可以产生显著的各向异性物理性质，即双曲线光学性质。在此，通过一步自组装工艺制备了自组装的HfO-Au纳米复合材料，其中直径仅为3 nm的超细垂直排列的Au纳米柱嵌入在HfO基质中。在生长过程中添加超薄的TiN-Au缓冲层可以明显提高薄膜的结晶度和柱体的均匀性。HfO-Au混合VAN薄膜在480 nm处表现出明显的等离子体共振，这远低于Au纳米结构的典型等离子体共振波长，这归因于排列良好的超细Au纳米柱。结合波长范围从1050 nm到1800 nm的宽双曲线色散以及独特的介电HfO，这种纳米级混合等离子体超材料在未来集成光学和电子开关器件的设计中具有强大的潜力。
