Transition metal dichalcogenides have emerged as promising materials for nanophotonic resonators because of their large refractive index, low absorption within a large portion of the visible spectrum, and compatibility with a wide range of substrates. Herein, we use these properties to fabricate WS2 double-pillar nanoantennas in a variety of geometries enabled by the anisotropy in the crystal structure. Using dark-field spectroscopy, we reveal multiple Mie resonances, to which we couple WSe2 monolayer photoluminescence and achieve Purcell enhancement and an increased fluorescence by factors up to 240 for dimer gaps of 150 nm. We introduce postfabrication atomic force microscope repositioning and rotation of dimer nanoantennas, achieving gaps as small as 10 ± 5 nm, which enables a host of potential applications, including strong Purcell enhancement of single-photon emitters and optical trapping, which we study in simulations. Our findings highlight the advantages of using transition metal dichalcogenides for nanophotonics by exploring applications enabled by their properties.
Bibliographical noteFunding Information:
P.G.Z., L.S., T.S.M., M.S., A.G., and A.I.T. gratefully acknowledge the financial support of the European Graphene Flagship Project under grant agreement 881603 and EPSRC grants EP/S030751/1, EP/V006975/1, and EP/P026850/1. L.S. and A.I.T. thank the European Union’s Horizon 2020 research and innovation programme under ITN Spin-NANO Marie Sklodowska-Curie grant agreement no. 676108. P.G.Z. and A.I.T. thank the European Union’s Horizon 2020 research and innovation programme under ITN 4PHOTON Marie Sklodowska-Curie grant agreement no. 721394. T.F.K. and D.C. acknowledges the support of the Engineering and Physical Sciences Research Council (grant number EP/P030017/1). Y.W. acknowledges a Research Fellowship (TOAST) awarded by the Royal Academy of Engineering. We also thank Cynthia Vidal for her contribution to the photoluminescence measurements of monolayer WSe on WS dimer nanoantennas. 2 2
© 2022 American Chemical Society.
- Mie resonators
- optical trapping
- photoluminescence enhancement
- Purcell enhancement
- transition metal dichalcogenides