Observation of a rich diversity of exciton-polaritons in Ag-CNTs bilayers

ORAL

Abstract

We demonstrate strong coupling between s- and p-polarized polaritons and the S22 transition in (6,5) carbon nanotubes (CNTs) as well as p-polarized polaritons and the S11 transition, in Ag-CNT thin film bilayers. Employing angle-resolved photoreflectance in the Kretschmann-Raether (K-R) configuration, we first show strong coupling between the p-polarized surface plasmon mode and the ground state S11 exciton. We find Rabi splitting of ~100 meV which is ~8% of the S11 exciton energy (1.24 eV), approaching the ultrastrong coupling limit. By varying the thickness of the CNT layer, we are able to observe higher energy polariton modes in both polarizations that couple to the S22 transition.  

We describe the experimental apparatus, sample optimization, and prospects for pushing the coupling strength higher.  

Finally, we optimize the system for strong coupling in water and discuss progress towards controlling electrochemical redox reactions with strong coupling-modified CNT working electrodes. 

*This work was authored [in part] by the National Renewable Energy Laboratory, operated by Alliance for Sustainable Energy, LLC, for the U.S. Department of Energy (DOE) under Contract No. DE-AC36-08GO28308. This work was supported in part by the U.S. Department of Energy, Office of Science, Office of Workforce Development for Teachers and Scientists (WDTS) under the Science Undergraduate Laboratory Internship (SULI) program. The views expressed in the article do not necessarily represent the views of the DOE or the U.S. Government. The U.S. Government retains and the publisher, by accepting the article for publication, acknowledges that the U.S. Government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this work, or allow others to do so, for U.S. Government purposes.

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Presenters

  • James C Howard

    • National Renewable Energy Lab

Authors

  • James C Howard

    • National Renewable Energy Lab

  • Bryon W Larson

    • National Renewable Energy Lab

  • Mark D Steger

    • National Renewable Energy Laboratory

  • Jeffrey L Blackburn

    • National Renewable Energy Lab

  • Andrew J Ferguson

    • National Renewable Energy Lab

  • Aaron H Rose

    • National Renewable Energy Laboratory