Hyperbolic Nanoparticles on Substrate with Separate Optical Scattering and Absorption Resonances: A Dual Function Platform for SERS and Thermoplasmonics

Abstract

Tuning optical properties of plasmonic nanostructures, including their absorption, scattering, and local‐field distribution is of great interest for various applications that rely on optical energy regulated by plasmonic effects. Conventional plasmonic nanostructures enhance light scattering and absorption simultaneously, leading to compromise for either surface‐enhanced spectroscopy or thermoplasmonic applications. In this paper, a dual functional platform based on a hyperbolic meta particles (HMP) substrate that exhibits separate and tuneable wavelengths of absorption and scattering resonances for both thermoplasmonics and surface enhanced Raman spectroscopy (SERS), is demonstrated. Significantly, either light‐to‐heat conversion efficiency at the absorption resonance band or SERS performance at the scattering resonance band of the HMP substrate is improved in comparison to those of plasmonic gold nanoparticles. Taking advantage of the flexible control of the separate scattering and absorption channels, the influence of the absorption resonance band position on the SERS signal is also investigated. The platform shows unique potential for in vitro biosensing in thermal modulation and in situ monitoring.

Strain‐Driven Thermal and Optical Instability in Silver/Amorphous‐Silicon Hyperbolic Metamaterials

“…[56] An interesting approach to overcome this limitation is to use natural hyperbolic materials, which derive their optical anisotropy from their crystal structure. [8,57] Other approaches to limit elastic strain driven degradation include geometrical designs beyond multilayers limiting the contact area with the surface [18,58,59] or substrate engineering aiming to reduce the CTE mismatch between the HMM and the substrate. [60]…”

“…[11] Multilayers are the most common realization of HMMs. [12] Of special interest is the interaction of temperature with multilayer HMMs, either in wavelength-switchable temperature-actuated hyperlenses [13] and super absorbers [14] or in applications with high operating temperatures such as thermophotovoltaics, [15,16] hyperthermia therapy, [17,18] or radiative cooling. [19][20][21] However, one of the key challenges for all of these proposed applications is thermal stability.…”

Graphene-Covered Silver Nanoisland Array Coupling with Hyperbolic Metamaterials for SERS Sensing

“…Lai et al used the absorption modifiability of an HMM to adjust its absorption peak to the infrared region to achieve a more significant SERS effect . Zhao et al separated the absorption and scattering bands of this structure by designing an HMM antenna element to generate a SERS signal with a higher signal-to-noise ratio . In our previous study, we demonstrated that Ag NPs coupled with HMM as an external coupling structure could significantly increase the electric field strength between nanoparticles .…”

“…25 Zhao et al separated the absorption and scattering bands of this structure by designing an HMM antenna element to generate a SERS signal with a higher signal-to-noise ratio. 26 In our previous study, we demonstrated that Ag NPs coupled with HMM as an external coupling structure could significantly increase the electric field strength between nanoparticles. 27 Obviously, the study on HMM-based SERS substrates has become popular, and designing an efficient layer of external coupling structure can effectively improve its performance.…”

Unveiling Long-Lived Hot-Electron Dynamics via Hyperbolic Meta-antennas

“…As the NIR wavelength region provides the maximum penetration of light through biological tissues, PM-PL in the NIR region is crucial to developing antiphotobleached fluorescent probes for imaging. At the same time, HMA also induces strong confinement of the electric field in the absorption band and increases the absorption efficiency to enhance the photothermal therapeutic capabilities. , …”