11:30 AM - NM02.03.07
Tip Enhanced Photoluminescence Based on Gold Pyramid Tip—Towards Inducing and Probing Highly Polarized and Localized Excitonic Emission in Atomically Thin Semiconductors
Junze Zhou1,Fabrizio Riminucci1,Edward Barnard1,Sriram Sridhar1,Archana Raja1,Shaul Aloni1,Adam Schwartzberg1,Alexander Weber-Bargioni1,Stefano Cabrini1
Lawrence Berkeley National Laboratory1
Manipulation and Localization of excitons in 2-D semiconducting systems have far fetching impact on the ability to design novel optoelectronic devices, study fundamental phenomena such as excitons condensation, as well as to create next generation single photon emitters, key for quantum information transduction and quantum sensing [1, 2]. 2-D Transition metal dichalcogenides such as WSe2 are a fascinating material class due to their direct band gap, high emissivity and strong exciton binding energies. Various approaches to engineer the localization of excitons in these materials have been pursued, via strain, intrinsic and extrinsic defect creation and heterostructures. While fascinating in their own respect, these approaches are at least in the moment difficult to scale. Using nano optical elements, such as plasmonic nano antennas, to locally enhance the radiative recombination rate by over an order of magnitude is another approach that leads itself to be more scalable that we would like to pursue here. In this presentation, we will introduce a new type nano-cavity configuration which is based on the gold coated pyramid scanning probe and gold nanogrooves on the substrate. By using this near-field probe, we have managed to mapping the highly polarized and localized excitonic emission from the WSe2, which is deposited on the top on the Gold nanogroove substrate, with an optical resolution below 50 nm. Our work helps to reveal intrinsic physic of the strong exciton-plasmon coupling and may contribute to designing many smart optoelectronic devices.
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