Optical Scattering of Liquid Gallium Nanoparticles Coupled to Thin Metal Films

Abstract

We investigate experimentally and numerically the scattering properties of liquid gallium nanoparticles coupled to a thin gold or silver film. The gallium nanoparticles are excited either directly by using inclined white light or indirectly by surface plasmon polaritons generated on the surface of the gold/silver film. In the former case, the scattering spectrum is always dominated by a scattering peak at ∼540 nm with a long-wavelength shoulder which is redshifted with increasing diameter of the gallium nanoparticle. Under the excitation of the surface plasmon polaritons, optical resonances with much narrower linewidths, which are dependent on the incidence angle of the white light, appear in the scattering spectra. In this case, the scattering spectrum depends weakly on the diameter of the gallium nanoparticle but the radiation pattern exhibits a strong dependence. In addition, a significant enhancement of electric field is expected in the gap region between the gallium nanoparticles and the gold film based on numerical simulation. As compared with the gallium nanoparticle coupled to the gold film which exhibit mainly yellow and orange colors, vivid scattering light spanning the visible light spectrum can be achieved in the gallium nanoparticles coupled to the silver film by simply varying the incidence angle. Gallium nanoparticles coupled to thin metal films may find potential applications in light–matter interaction and color display.

Gallium‐Based Liquid Metals: Optical Properties, Applications, and Challenges

“…Albella et al [57] explored the plasmonic behavior of Ga-based LMs NPs by examining their scattering and absorption properties on dielectric substrates and verified their dependence on size and shape. Lan et al [58] studied the scattering properties by changing the substrate. The Ga NPs were coupled to silver and gold metal films, demonstrating their potential applications in light-matter interactions and color displays.…”

“…Lan et al. [ 58 ] studied the scattering properties by changing the substrate. The Ga NPs were coupled to silver and gold metal films, demonstrating their potential applications in light–matter interactions and color displays.…”

Nano‐Biomedicine based on Liquid Metal Particles and Allied Materials

“…Unlike the plasmonic properties of gold and silver nanoparticles, which mostly expand the resonance range from the visible to IR areas, gallium nanoparticles are endowed with unique UV plasmonics. [ 102,103 ] Due to the surface plasmon resonances (SPR), they present absorption, spanning from the UV to visible regions. The gallium‐based plasmonics render them the potential to substitute these noble nanoparticles and to extend applications in UV plasmonic resonance, including the surface‐enhanced Raman spectroscopy, fluorescence spectroscopy and DNA detection.…”

Revealing the quadrupole radiation of liquid gallium nanospheres

“…4,10) Most recently, Ga nanoparticles (NPs) have attracted increasing research attention because of their strong surface plasmon resonances in the ultraviolet (UV) region, which is mainly due to the negative real part of the electric function and the low imaginary part of the dielectric function. [11][12][13][14][15][16][17][18] Novel applications such as all-optical phasechange memory and logic devices, 19) surface-enhanced Raman spectroscopies, 13,14) deep-subwavelength spectroscopic imaging, 12) environmental remediation, 20) and hot-electron intraband luminescence 21) have been achieved relying on the plasmonic resonances of Ga NPs. Compared with other candidates for plasmonic resonances in the UV spectral range, [22][23][24][25][26][27][28][29] such as silver, magnesium, and aluminum, Ga NPs are stable in the atmosphere owing to the existence of a thin native oxide shell (Ga 2 O 3 ).…”