Hybrid cube-in-cup nanoantenna: towards ordered photonics

Abstract

The most significant goal of nanophotonics is the development of high-speed quantum emitting devices operating at ambient temperature. In this regard, plasmonic nanoparticles-on-mirror are potential candidates for designing high-speed photon sources. We introduce a novel hybrid nanoantenna (HNA) with CdSe/CdS colloidal quantum dots (QDs) based on a silver nanocube in a metal cup that presents a nanoparticle-in-cavity coupled with an emitters system. We use focused ion beam nanolithography to fabricate an ordered array of cups, which were then filled with colloidal nanoparticles using the most simple drop-casting and spin coating methods. The spectral and time-resolved studies of the samples with one or more nanocubes in the cup reveal a significant change in the radiation characteristics of QDs inside the nanoantenna. The Purcell effect causes an increase in the fluorescence decay rate (≥30) and an increase in the fluorescence intensity (≥3) of emitters in the HNA. Using the finite element method simulations, we have discovered that the proximity of the cups wall affects the oscillation modes of the gap plasmon, which, in turn, leads to changes in the electric field enhancement inside the nanoantenna gap. Additionally, substantial variations in the behavior of the gap plasmons at different polarizations of the exciting radiation have been revealed. The proposed nanoantenna can be useful in the development of plasmonic sensors, display pixels, and single-photon sources.

Effectively enhancing silicon-vacancy emission in a hybrid diamond-in-pit microstructure

“…In order to produce arrays of cylindrical pits, a Si/SiO 2 wafer with a deposited thin gold layer (∼500 nm) was used. A focused gallium ion beam etched the gold surface according to a special procedure [27]. As a result, a square array of cylindrical gold pits was obtained.…”

“…For the EF estimation, we added an edge curvature radii equal to 50 nm and sidewalls beveled at 10 • for the nanopit to better simulate the experimental conditions. For emission power, QE, and collection efficiency (CE) estimation, we use approaches described in [25][26][27].…”

Surface-enhanced photoluminescence and Raman spectroscopy of single molecule confined in coupled Au bowtie nanoantenna

“…Nanoantenna structures supporting LSPR offer a way to break the optical diffraction limit by concentrating light into subwavelengths [6][7][8][9]. The distribution of the electric field depends on the configuration of plasmonic nanoantenna, which typically exhibits strong enhancement and localization on the surface of the antenna, especially at the smaller tips and gaps of dimers or polymers [10][11][12][13][14][15]. In recent years, the enhanced electric filed due to plasmon coupling effect can improve molecular absorption and has been applied to many optical and sensing fields, including surface-enhanced Raman scattering (SERS), surfaced-enhanced fluorescence (SEF) and single molecule detection technology [16][17][18].…”