We demonstrate that a hybrid c-Si/Au nanocavity can serve as a multifunctional sensing platform for nanoscale (about 100 nm) thermometry with high accuracy (>0.4 K) and fast response (<0.1 second), controlled local optical heating up to 1200 K and also provide Raman scattering enhancement (>10^4 fold). The system has been tested in the experiment on thermally induced unfolding of BSA molecules, plased inside the hybrid nanocavity. Moreover, numerical modeling reveal, that two possible operation modes of the system: with and without considerable optical heating at the nanometer scale, while other functionalities (nanothermometry, RS enhancement, and tracing the events) are preserved. These regimes make the hybrid nanocavity more versatile sensing system than fully plasmonic counterparts. The simplicity and multifunctionality of the hybrid nanocavity make it a promising platform for photochemistry and photophysics applications.
It is shown experimentally that the irradiation of thin Al and Au films of thickness 50 to 100 nm on a silicate glass surface by electrons results in effects that differ principally depending on the electron energy. For energies of 5 to 15 keV, the irradiation leads to an increase in the film thickness throughout the irradiated zone and a decrease in the thickness in the surrounding area. For an energy of 25 keV, the irradiation leads to dissolving the Au film in glass in the irradiated zone. The mechanisms of the observed effects are discussed.
Domino modes are highly-confined collectivemodes that were first predicted for a periodic arrangement of metallic
parallelepipeds in far-infrared region. The main feature of domino modes is the advantageous distribution of the
local electric field, which is concentrated between metallic elements (hot spots), while its penetration depth in
metal is much smaller than the skin-depth. Therefore, arrays of non-resonant plasmonic nanoantennas exhibiting
domino modes can be employed as broadband light trapping coatings for thin-film solar cells. However, until
now in the excitation of such modes was demonstrated only in numerical simulations. Here, we for the first
time demonstrate experimentally the excitation of optical domino modes in arrays of non-resonant plasmonic
nanoantennas. We characterize the nanoantenna arrays produced by means of electron beam lithography both
experimentally using an aperture-type near-field scanning optical microscope and numerically. The proof of
domino modes concept for plasmonic arrays of nanoantennas in the visible spectral region opens new pathways
for development of low-absorptive structures for effective focusing of light at the nanoscale.