Hybrid Dielectric-Plasmonic Nanoantenna with Multiresonances for Subwavelength Photon Sources

Hybrid Dielectric-Plasmonic Nanoantenna with Multiresonances for Subwavelength Photon Sources

ACS Photonics

10.1021/acsphotonics.2c01332

http://dx.doi.org/10.1021/acsphotonics.2c01332

Pavel A. Dmitriev, Emmanuel Lassalle, Lu ding, Zhenying Pan, Darren C. J. Neo, Vytautas Valuckas, Ramón Paniagua-Domínguez, Joel K. W. Yang, Hilmi Volkan Demir, Arseniy I. Kuznetsov

Electrical and Electronic Engineering, Atomic and Molecular Physics, and Optics, Biotechnology, Electronic, Optical and Magnetic Materials

22 February 2023

Dmitriev, P. A., Lassalle, E., Ding, L., Pan, Z., Neo, D. C. J., Valuckas, V., Paniagua-Dominguez, R., Yang, J. K. W., Demir, H. V., & Kuznetsov, A. I. (2023). Hybrid Dielectric-Plasmonic Nanoantenna with Multiresonances for Subwavelength Photon Sources. ACS Photonics, 10(3), 582–594. https://doi.org/10.1021/acsphotonics.2c01332

The enhancement of the photoluminescence of quantum dots induced by an optical nanoantenna has been studied considerably, but there is still significant interest in optimizing and miniaturizing such structures, especially when accompanied by an experimental demonstration. Most of the realizations use plasmonic platforms, and some also use all-dielectric nanoantennas, but hybrid dielectric-plasmonic (subwavelength) nanostructures have been very little explored. In this paper, we propose and demonstrate single subwavelength hybrid dielectric-plasmonic optical nanoantennas coupled to localized quantum dot emitters that constitute efficient and bright unidirectional photon sources under optical pumping. To achieve this, we devised a silicon nanoring sitting on a gold mirror with a 10 nm gap in-between, where an assembly of colloidal quantum dots is embedded. Such a structure supports both (radiative) antenna mode and (nonradiative) gap mode resonances, which we exploit for the dual purpose of out-coupling the light emitted by the quantum dots into the far-field with out-of-plane directivity, and for enhancing the excitation of the dots by the optical pump. Moreover, almost independent control of the resonance spectral positions can be achieved by simple tuning of geometrical parameters such as the ring inner and outer diameters, allowing us to conveniently adjust these resonances with respect to the quantum dots emission and absorption wavelengths. Using the proposed architecture, we obtain experimentally average fluorescence enhancement factors up to 654× folds mainly due to high radiative efficiencies, and associated with a directional emission of the photoluminescence into a cone of ±17° in the direction normal to the sample plane. We believe the solution presented here to be viable and relevant for the next generation of light-emitting devices.

Publisher Copyright

This research / project is supported by the A*STAR SERC - Pharos program
Grant Reference no. : 1527300025

This research / project is supported by the A*STAR - MTC Programmatic
Grant Reference no. : M21J9b0085

This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Photonics, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see doi.org/10.1021/acsphotonics.2c01332

https://oar.a-star.edu.sg/communities-collections/articles/19685

2330-4022

Institute of Materials Research and Engineering