“Black” Titania Coatings Composed of Sol-Gel Imprinted Mie Resonators Arrays
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- 作者：Thomas Bottein ; Thomas Wood ; Thomas David ; Jean Benoî ; t Claude ; Luc Favre ; Isabelle Berbé ; zier ; Antoine Ronda ; Marco Abbarchi and David Grosso
- 刊名：Advanced Functional Materials
- 出版年：2017
- 出版时间：January 12, 2017
- 年：2017
- 卷：27
- 期：2
- 全文大小：2137K
- ISSN：1616-3028
文摘
Optical technologies and devices rely on the controlled manipulation of light propagation through a medium. This is generally governed by the inherent effective refractive index of the material as well as by its structure and dimensionality. Although a precise control over light propagation with sub-wavelength size objects is a crucial issue for a plethora of applications, the widely used fabrication methods remain cumbersome and expensive. Here, a sol–gel dip-coating method combined with nanoimprinting lithography on arbitrary glass and silicon substrates is implemented for the fabrication of TiO2-based dielectric Mie resonators. The technique allows obtaining sub-micrometric pillars featuring unprecedented vertical aspect ratios (>1) with relatively high fidelity and precision. Spectroscopic characterization at visible and near-infrared frequencies demonstrate that the resonant properties of these dielectric pillar arrays allow for a drastic reduction of light transmission (cutting more than 50% on glass) and reduced reflection (reflecting less than 3% on glass and 16% on bulk silicon), accounting for an efficient light trapping. These results provide a guideline for the fabrication of Mie resonators using a fast, versatile, low-cost, low-temperature technique for efficient light manipulation at the nanoscale.