Large‐Scale Fabrication of Shaped High Index Dielectric Nanoparticles on a Substrate and in Solution

Abstract

enable realization of large-scale nanostructured HID materials with well-defined physical and optical properties. Electron beam lithography has been the method of choice for proof-of-concept metasurface applications, but simpler and cheaper fabrication methods are needed to upscale new ideas into commercial devices. Several such methodologies have indeed been proposed, each technique with its own advantages and drawbacks. [19] For example, dewetting [20] and laser ablation methods from bulk HID materials [6,21] can easily be upscaled, but they are difficult to control and result in a large degree of particle heterogeneity. Nanoimprint lithography [22] and laser assisted deposition [23] are more precise, but the first requires the use of expensive masks and the latter is not yet upscalable.

Possibility of negative refraction for visible light in disordered all-dielectric resonant high index metasurfaces

“…These metasurfaces are realized as regular lattices of the scattering elements with subwavelength sizes. Currently, the shape and size of the high index particles can be precisely controlled [8]. However, precious positioning of these elements is not an easy task.…”

Low‐Loss Hybrid High‐Index Dielectric Particles on a Mirror for Extreme Light Confinement

“…Samples were made by dispersing a solution containing nearly identical (<10% size dispersion) Si nanodisks (height 60 nm, diameter 160 nm) on an ultra‐flat Au film with root mean square roughness smaller than 3 Å over a 400 µm 2 region. The colloidal solution was made by a particle removal technique (see Figure c and method for details) developed in our lab, which enables the realization of complex‐shaped Si particles in solution . In brief, a large‐area surface composed of high‐quality poly‐Si nanodisks was fabricated on a fused silica substrate .…”

“…The colloidal solution was made by a particle removal technique (see Figure 1c and method for details) developed in our lab, which enables the realization of complex-shaped Si particles in solution. [40] In brief, a large-area surface composed of high-quality poly-Si nanodisks was fabricated on a fused silica substrate. [44] Afterward, the particles were released by selective substrate etching, dispersed in a water solution containing citrate buffer as a stabilizing agent and dried on the Au substrate.…”

“…Recently our group had developed a novel fabrication technique that is able to produce HID nanostructures with nearly any desired shape/size, while maintaining high‐quality crystalline quality of the material and therefore low absorptive losses in the red region of the visible spectrum. This fabrication technique is described in further detail in Section , “Fabrication.” Essentially, the method uses a high‐quality poly‐Si film, and the desired nanoparticles are etched from this film. The newly created Si nanoparticles are then removed from the substrate and dispersed into a colloidal solution.…”

“…This fabrication technique is described in further detail in Section 2, "Fabrication." [39,40] Essentially, the method uses a highquality poly-Si film, and the desired nanoparticles are etched from this film. The newly created Si nanoparticles are then removed from the substrate and dispersed into a colloidal solution.…”