Observation of the enhancement of electric fields normal to the surface using mid-infrared slot antennas and an atomic layer deposition technique

Nishimura, Yuki; Kawano, Tomikazu; Kunichika, Y.; Kasahara, K.; Yaji, Toyonari; Ikeda, Naoki; Oosato, H.; Miyazaki, Hideki T.; Sugimoto, Yoshimasa

doi:10.1016/j.optcom.2015.03.063

Cited by 3 publications

(4 citation statements)

References 21 publications

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“…Additionally, phononic excitations of SiO 2 layers (see section ) were used to probe the vertical near-field distribution of electrical fields produced by nanoantennas . To demonstrate this, Nishimura et al fabricated slot antennas on thin SiO 2 films separated by Al 2 O 3 spacer layers with several thicknesses.…”

Section: Applications Of Resonant Seiramentioning

confidence: 99%

“…Additionally, phononic excitations of SiO 2 layers (see section 5) were used to probe the vertical near-field distribution of electrical fields produced by nanoantennas. 218 To demonstrate this, Nishimura et al fabricated slot antennas on thin SiO 2 films separated by Al 2 O 3 spacer layers with several thicknesses. As a result, the authors observed a decrease in SiO 2 -signal with increasing Al 2 O 3 layer thickness, because the near-field overlap of the antennas with the SiO 2 layer decreases.…”

Section: Assessing Plasmonic Near-fieldsmentioning

confidence: 99%

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Surface-Enhanced Infrared Spectroscopy Using Resonant Nanoantennas

et al. 2017

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Infrared spectroscopy is a powerful tool widely used in research and industry for a label-free and unambiguous identification of molecular species. Inconveniently, its application to spectroscopic analysis of minute amounts of materials, for example, in sensing applications, is hampered by the low infrared absorption cross-sections. Surface-enhanced infrared spectroscopy using resonant metal nanoantennas, or short "resonant SEIRA", overcomes this limitation. Resonantly excited, such metal nanostructures feature collective oscillations of electrons (plasmons), providing huge electromagnetic fields on the nanometer scale. Infrared vibrations of molecules located in these fields are enhanced by orders of magnitude enabling a spectroscopic characterization with unprecedented sensitivity. In this Review, we introduce the concept of resonant SEIRA and discuss the underlying physics, particularly, the resonant coupling between molecular and antenna excitations as well as the spatial extent of the enhancement and its scaling with frequency. On the basis of these fundamentals, different routes to maximize the SEIRA enhancement are reviewed including the choice of nanostructures geometries, arrangements, and materials. Furthermore, first applications such as the detection of proteins, the monitoring of dynamic processes, and hyperspectral infrared chemical imaging are discussed, demonstrating the sensitivity and broad applicability of resonant SEIRA.

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Section: Applications Of Resonant Seiramentioning

confidence: 99%

Section: Assessing Plasmonic Near-fieldsmentioning

confidence: 99%

Surface-Enhanced Infrared Spectroscopy Using Resonant Nanoantennas

et al. 2017

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“…Another technique is scanning near-field optical microscopy (SNOM), which can directly map the near-field intensity distribution around plasmonic nanoantennas in the MIR wavelength range. ,, However, SNOM is unable to accurately measure the electric field strength felt by the monolayer on NP surfaces because its spatial resolution is limited by the tip radius (a few nanometers) . In addition, the finite-difference time-domain (FDTD) simulation is an effective method for calculating the local field distribution, but its result needs to be verified by comparison with experiments . Moreover, the strength of molecular vibration in surface-enhanced infrared absorption spectroscopy (SEIRA) has been demonstrated to be a local probe for detecting the plasmon near-field intensity of substrates. , Nevertheless, it needs to subtract the contribution of the surface molecular number to SEIRA signals.…”

mentioning

confidence: 99%

“…22 In addition, the finite-difference time-domain (FDTD) simulation is an effective method for calculating the local field distribution, but its result needs to be verified by comparison with experiments. 28 Moreover, the strength of molecular vibration in surface-enhanced infrared absorption spectroscopy (SEIRA) has been demonstrated to be a local probe for detecting the plasmon near-field intensity of substrates. 18,22 Nevertheless, it needs to subtract the contribution of the surface molecular number to SEIRA signals.…”

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confidence: 99%

Probing the Local Near-Field Intensity of Plasmonic Nanoparticles in the Mid-infrared Spectral Region

Pei,

Zheng,

Tan

et al. 2024

J. Phys. Chem. Lett.

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The enhanced local field of gold nanoparticles (AuNPs) in mid-infrared spectral regions is essential for improving the detection sensitivity of vibrational spectroscopy and mediating photochemical reactions. However, it is still challenging to measure its intensity at subnanometer scales. Here, using the NO2 symmetric stretching mode (νNO2 ) of self-assembled 4-nitrothiophenol (4-NTP) monolayers on AuNPs as a model, we demonstrated that the percentage of excited νNO2 mode, determined by femtosecond time-resolved sum-frequency generation vibrational spectroscopy, allows us to directly detect the local field intensity of the AuNP surface in subnanometer ranges. The local-field intensity is tuned by AuNP diameters. An approximate 17-fold enhancement was observed for the local field on 80 nm AuNPs compared to the Au film. Additionally, the local field can regulate the anharmonicity of the νNO2 mode by synergistic effect with molecular orientation. This work offers a promising approach to probe the local field intensity distribution around plasmonic NP surfaces at subnanometer scales.

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