Deterministic\nAssembly of Single-Emitter Plasmonic\nAntenna for Ultrahigh Photoluminescence Enhancement

Single-emitter nanoantennas play a crucial role in the\nfabrication\nof nanosensors and integrated sources. Since the coupling of single\nemitter to nanoantennas is largely based on stochastic methods, low\nqualified rate still hinders a massive deployment. Here, we proposed\na deterministic, optical-force-driven method to achieve gap-plasmonic\nphotoluminescence enhancement. Two deterministic steps are carried\nout in sequence: a composite nanoemitter is first synthesized by linking\nquantum dots to a silica-rapped gold nanoparticle, followed by an\noptical delivery of the nanoparticle into a nanoaperture in a gold\nfilm. We reason that the nanoparticle-in-nanoaperture (NPiNA) structure\nefficiently couples out-of-plane excitation light into a gap-plasmon\nvia a transverse electromagnetic mode (TEM)-like transmission mode.\nAn <i>in situ</i> photoluminescence measurement demonstrates\na 3× brightness as compared to the nanoparticle-on-mirror (NPoM).\nThis approach paves the way toward deterministic positioning of individual\nnanoparticles for a wide range of applications on nanophotonics structures\non-a-chip.