Anomalous light trapping enhancement in a two-dimensional gold nanobowl array with an amorphous silicon coating

Abstract

A facile polymethyl methacrylate-assisted turnover-transfer approach is developed to fabricate uniform hexagonal gold nanobowl arrays. The bare array shows inferior light trapping ability compared to its inverted counterpart (a gold nanospherical shell array). Surprisingly, after being coated with a 60-nm thick amorphous silicon film, an anomalous light trapping enhancement is observed with a significantly enhanced average absorption (82%), while for the inverted nanostructure, the light trapping becomes greatly weakened with an average absorption of only 66%. Systematic experimental and theoretical results show that the main reason for the opposite light trapping behaviors lies in the top amorphous silicon coating, which plays an important role in mediating the excitation of surface plasmon polaritons and the electric field distributions in both nanostructures.

Self-organized and self-assembled TiO2 nanosheets and nanobowls on TiO2 nanocavities by electrochemical anodization and their properties

“…The diameter and thickness were about 76 nm and 74 nm, respectively; and the separation distance between nanobowls of around 30 nm. Likewise, our TiO 2 -nb had shorter dimensions (thickness and diameter) than another published in literature [9][10][11][12][13][14][15][16][17]. Additionally, in figures 2(b) and (d), it can be seen the top of the nanocavities (TiO 2 -nc) as some little black circles, like pores, between the spaces of the nanosheets and nanobowls.…”

“…In the same way, nanobowls are nanostructured materials that have a shape of bowl or cup whose outer diameter is about or smaller than 100 nanometers [10]. Because of their excellent physical, optical and chemical properties, nanobowls are used in the field of the nanophotonics and photoelectrochemistry, in applications such as sieves for selecting particles, as nanocontainers or as light trappings [11,12]. Typically, nanobowls are synthesized by a colloidal crystal template, a facile solid state dewetting, microwave heating, atomic layer deposition or template-sol-gel processes [10][11][12][13][14][15][16][17].…”

“…Because of their excellent physical, optical and chemical properties, nanobowls are used in the field of the nanophotonics and photoelectrochemistry, in applications such as sieves for selecting particles, as nanocontainers or as light trappings [11,12]. Typically, nanobowls are synthesized by a colloidal crystal template, a facile solid state dewetting, microwave heating, atomic layer deposition or template-sol-gel processes [10][11][12][13][14][15][16][17]. Nonetheless, nanobowls are usually fabricated in larger dimensions, closed to 500 nm of outer diameter, and having a high manufacturing cost [12][13][14][15][16][17].…”

3D Hierarchical Nanorod@Nanobowl Array Photoanode with a Tunable Light‐Trapping Cutoff and Bottom‐Selective Field Enhancement for Efficient Solar Water Splitting

“…The optical properties of the Fe 2 O 3 NB photoanode with diameter of 0.5, 0.8, and 1.0 µm were measured by UV–vis spectroscopy, and presented in the form of the efficiencies of light harvesting (LHE) in Figure b. The absorption of Fe 2 O 3 NB is much higher than that of the planar structure, and the absorption band edges is 600 nm (close to the planar one), 615 nm, and 630 nm, respectively (more detail in Figure S4, Supporting Information), which showed similar trend to simulated results and also was accorded with the previous nanobowl arrays structure made of other material such as Si and TiO 2 applied in the Structural Color . The absorption edge shift as the diameter increasing can be explained by light diffraction and refraction theories .…”

Nanoparticles/Parabolic Nanobowl Hybrid Structure as a Surface-Enhanced Raman Scattering Substrate: Insights Using the FDTD Method

“…When the excitation light frequency matches the resonant frequency of the NPs, the local surface plasmon resonance (LSPR) effect occurs, forming “hot spots” in local spaces . Many different nanostructures with “hot spots” have been prepared to tune the optical field, making the physical enhancement of SERS extremely large, such as nanocubes, self-assembled nanospheres, nanobowtie, nanobowls, etc. − …”