Paldi Robynne L, Sun Xing, Wang Xuejing, Zhang Xinghang, Wang Haiyan
School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907, United States.
School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States.
ACS Omega. 2020 Jan 28;5(5):2234-2241. doi: 10.1021/acsomega.9b03356. eCollection 2020 Feb 11.
Hyperbolic metamaterials demonstrate exotic optical properties that are poised to find applications in subdiffraction imaging and hyperlenses. Key challenges remain for practical applications, such as high energy losses and lack of hyperbolic properties in shorter wavelengths. In this work, a new oxide-metal (ZnO-Au) hybrid-material system in the vertically aligned nanocomposite thin-film form has been demonstrated with very promising in-plane two-phase ordering using a one-step growth method. Au nanopillars grow epitaxially in the ZnO matrix, and the pillar morphology, orientation, and quasi-hexagonal in-plane ordering are found to be effectively tuned by the growth parameters. Strong surface plasmon resonance has been observed in the hybrid system in the UV-vis range, and highly anisotropic dielectric properties have resulted with much broader and tunable hyperbolic wavelength regimes. The observed strain-driven two-phase in-plane ordering and its novel tunable hyperbolic metamaterial properties all demonstrate strong potential for future oxide-metal hybrid-material design toward future integrated hybrid photonics.
双曲线超材料展现出奇异的光学特性，有望在亚衍射成像和超透镜中得到应用。然而，实际应用仍面临一些关键挑战，比如高能量损耗以及在较短波长下缺乏双曲线特性。在这项工作中，一种垂直排列的纳米复合薄膜形式的新型氧化物-金属（ZnO-Au）混合材料体系已被证实，通过一步生长法实现了非常有前景的面内两相有序排列。金纳米柱在ZnO基质中外延生长，并且发现柱的形态、取向和准六边形面内有序排列可通过生长参数有效调节。在该混合体系的紫外-可见范围内观察到了强烈的表面等离子体共振，并且产生了高度各向异性的介电特性，具有更宽且可调谐的双曲线波长范围。所观察到的应变驱动的面内两相有序排列及其新颖的可调谐双曲线超材料特性，都展示了未来氧化物-金属混合材料设计在未来集成混合光子学方面的强大潜力。
