Paldi Robynne L, Lu Juanjuan, Pachaury Yash, He Zihao, Bhatt Nirali A, Zhang Xinghang, El-Azab Anter, Siddiqui Aleem, Wang Haiyan
School of Materials Engineering, Purdue University, West Lafayette, IN 47907, USA.
School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN 47907, USA.
Molecules. 2022 Mar 9;27(6):1785. doi: 10.3390/molecules27061785.
Hyperbolic metamaterials are a class of materials exhibiting anisotropic dielectric function owing to the morphology of the nanostructures. In these structures, one direction behaves as a metal, and the orthogonal direction behaves as a dielectric material. Applications include subdiffraction imaging and hyperlenses. However, key limiting factors include energy losses of noble metals and challenging fabrication methods. In this work, self-assembled plasmonic metamaterials consisting of anisotropic nanoalloy pillars embedded into the ZnO matrix are developed using a seed-layer approach. Alloys of AuAl or AuCu are explored due to their lower losses and higher stability. Optical and microstructural properties were explored. The ZnO-AuCu system demonstrated excellent epitaxial quality and optical properties compared with the ZnO-AuAl system. Both nanocomposite systems demonstrate plasmonic resonance, hyperbolic dispersion, low losses, and epsilon-near-zero permittivity, making them promising candidates towards direct photonic integration.
双曲线超材料是一类由于纳米结构的形态而呈现各向异性介电函数的材料。在这些结构中，一个方向表现为金属，而正交方向表现为介电材料。其应用包括亚衍射成像和超透镜。然而，关键的限制因素包括贵金属的能量损失和具有挑战性的制造方法。在这项工作中，使用种子层方法开发了由嵌入ZnO基质中的各向异性纳米合金柱组成的自组装等离子体超材料。由于AuAl或AuCu合金具有较低的损耗和较高的稳定性，因此对其进行了探索。研究了光学和微观结构特性。与ZnO-AuAl系统相比，ZnO-AuCu系统表现出优异的外延质量和光学特性。两种纳米复合系统都表现出等离子体共振、双曲线色散、低损耗和近零介电常数，这使其成为直接光子集成的有前途的候选材料。
