Plasmonic Enhancement Mechanism of Template‐Based Synthesized Au@TiO₂ Nanodiscs

Abstract

The localized plasmon resonance enhancement mechanisms were investigated as a function to increase the shell thickness of the prepared hexagonal nanodiscs arrays of Au@TiO2 core‐shell. The bare Au hexagonal nanodiscs array exhibited multiple plasmon resonance modes in the ultraviolet (UV) to near‐infrared (NIR) region. Au@TiO2 nanodiscs configuration present three different enhancement mechanisms with increasing TiO2 shell thickness. First, a strengthened plasmon‐induced resonance energy transfer (PIRET) for higher plasmonic resonance mode in the UV region. Second, redshifted and broadened direct electron transfer (DET) processes for the plasmonic dipole resonance mode from the Vis to the NIR region. Third, an increased hybridization retardation effect for the higher plasmonic mode in the Vis region. By using a facile and cost‐effective technique (nonlithographic route) to fabricate highly ordered core‐shell nanodiscs arrays (Au@TiO2 hexagonal nanodiscs) on a large area of Si substrate (>cm2) via an ultrathin alumina membrane (UTAM), this technique provides a perfect shadow mask to fabricate Au nanodiscs arrays; furthermore, the shadow effect of UTAM pores offers enough space to cover Au nanodiscs by the TiO2. These plasmonic core‐shell nanodiscs reveal a highly promising pathway to discovering new enhancement phenomena that can be applied in diverse applications such as plasmon‐enhanced energy conversion, biosensing, and surface‐enhanced vibrational spectroscopy.

Influence of Graphene Sheets Accumulation on Optical Band Gap Enhanced Graphite Exfoliation

“…software for phase analysis, respectively [32][33][34]. Figure 4 demonstrates all the rGO samples with different accumulative layer thicknesses (8,16,24,32,40, and 80 nm) correspond to dried drop numbers of rGO solution (D1, D2, D3, D4, D5, and D10), respectively. The samples have the highest absorption at UV spectra due to the aromatic C-C bonds which is consistent with other reports [35][36][37].…”

“…these observations suggest the gradual restoration of the π→π conjugated structure within the graphene nanosheets [38]. Whereas graphene has been classified as a typical indirect semiconductor and based on the absorbance spectra of the rGO sample, an indirect transition model was utilized to evaluate the optical band gap (Eg) values of each prepared thickness (layers) [39,40], as shown in Figure 5.…”

Optical and Electrical Conductivity of SnO:Cu Nanoparticles

“…Figure (1-a) displays the X-ray diffraction of the pure and copper doped tin oxide at a different weight ratio (2,4,6,8) wt% and notes from the figure that all the membranes are poly-crystalline pattern. The prevailing reflection is the (110) plane at the angle 2θ = 29.96 o , with the number of secondary reflections in ( 101 As can be seen from figure (2-a) the crystallite size fluctuates between decreases and increases to 24.32 nm with the height weight ratio of Cu dopant.…”

“…The thin-film and nanotechnology are the most important techniques that contributed to the enhancement and development of semiconductor materials applications [1][2]. Even in the balance of micro composition [3] and transparent conductive oxides (Transparent conductors) [4] [5]. In addition, the oxide SnO 2 material has three advantages; a high conductivity, low resistivity, and high optical transmittance [6].…”

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This study included a different weight ratio of copper (2,4,6,8) wt% as a dopant, with tin oxide SnO 2 deposits on glass substrate by RF reactive magnetron sputter. The structural properties show polycrystalline pattern nature for all deposit samples with dominated reflection (110).

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