CC BY
5ALT'22
LASER DIAGNOSTICS AND SPECTROSCOPY
LD-I-6
Photomodification of Silver Nanocubes for Patch Plasmonic Nanoantennas by Visible Laser Light
S.G. Lukishova
Rochester, NY, USA [email protected]
From all types of plasmonic nanoantennas, the highest Purcell factor with increasing emitter radiative decay rate was obtained with metal plasmonic patch (gap) nanoantennas (a dielectric nanogap with emitters between a metal nanopar-ticle of a given shape (cube, triangle, etc.) and a metal film [1]. Silver nanoparticles, for instance, nanocubes [2-7] or their arrays [6] are used in patch nanoantennas for emitter fluorescence enhancement in visible spectral range [2-6] as well as for increasing stability and brightness of organic light emitting devices (OLEDs) [7]. We observed spontaneous intensity spikes up to ~400-900 kcounts/s, as well as a step-wise several times, increase in photoluminescence from silver nanocubes. Cw, 532 or 633 nm laser excitation was used (~100 ^W incident power with a 1.30 numerical aperture, oil immersion objective). These spontaneous spikes may influence the purity of single-photon emission from single emitters and even prevent photon antibunching. We investigated 100-nm silver nanocubes from nanoComposix protected by a few nanometer layers of polyvinylpyrrolidone (PVP), typically used in patch nanoantennas. Such spontaneous appearance of bright photoluminescence can be a result of photomodification of nanocube surface with formation over time of bright, few nanometer silver nanoclusters [8-10] on an oxidized surface of nanocubes. Confocal fluorescence microscopy micrographs showed appearance in time bright features with single-molecule behavior (stripes and semicircles in raster scans). These effects should be considered working with silver plasmonic nanostructures, especially under cw laser irradiation, see also [11,12].
[1] S.G. Lukishova and L.J. Bissell, "Nanophotonic advances for room-temperature single-photon sources", pp.103-178, in Quantum Photonics: Pioneering Advances and Emerging Applications, R.W. Boyd, S.G. Lukishova, V.N. Zadkov (Eds.), Springer (2019).
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[6] A.V. Gritsienko et al., "Optical properties of new hybrid nanoantenna in submicron cavity", J. Physics: Conf. Series 2015, 012052 (2021).
[7] M.A. Fusella et al., "Plasmonic enhancement of stability and brightness in organic light-emitting devices", Nature 585, 37 (2020).
[8] LA. Peyser et al.,"Photoactivated fluorescence from individual silver nanoclusters", Science 291, 5501, 103 (2001).
[9] L.A. Peyser et al.,"Mechanism of Agn nanocluster photoproduction from silver oxide films", J. Phys. Chem. B 106, 7725-7728 (2002).
[10] C.D. Geddes et al., "Luminescent blinking from silver nanostructures", J. Phys. Chem. B 107, 9589 (2003).
[11] S.G. Lukishova, J. Brone, Z. Li, L. Young, "Photomodification of silver nanocubes for patch plasmonic nanoantennas by visible laser light", Book of Abstracts, the 51st Winter Colloquium on Physics of Quant. Electron., p. 154 (Snowbird, Utah, January 2022).
[12] S.G. Lukishova, J. Brone, D. Khan and Z. Li, "Ultrabright photoluminescence spikes and stepwise photoluminescence increase from colloidal silver nanoparticles for patch nanoantennas", J. Physics: Conf. Series. 2249, 012002 (2022).
