Studying the driving force of photoelectrochemical reactions on semiconductor electrodes under strong coupling conditions

POSTER

Abstract



Strong exciton-polariton coupling hybridizes semiconductor and photon modes, splitting the energy levels of the system (Rabi splitting) and thus modifying the photonic, electronic, and chemical properties of the semiconductor. While there have been many demonstrations of using strong coupling to tune optical properties, there is very limited work showing tuning of chemical reactions in liquid electrolyte.

In this work we show progress towards moving strong coupling studies into an aqueous electrochemical environment. Our photoelectrode consists of a plasmonic thin film metal coated with a layer of semiconducting carbon nanotubes (CNTs). The plasmon is tuned to overlap with the ground state S11 exciton of the CNTs, leading to strong coupling. We measure charge transfer photocurrent as a function of potential for different redox species to test the hypothesis that the overpotential is reduced under strong coupling conditions.

As an open-polariton cavity system, our technique offers a way to study conventional photoelectrochemistry under strong coupling conditions, potentially opening the door to photonic control of chemical reactions.


*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.

Presenters

  • James C Howard

    • National Renewable Energy Lab

Authors

  • James C Howard

    • National Renewable Energy Lab

  • Mark D Steger

    • National Renewable Energy Laboratory

  • Bryon W Larson

    • National Renewable Energy Lab

  • Jeffrey L Blackburn

    • National Renewable Energy Lab
    • National Renewable Energy Laboratory

  • Andrew J Ferguson

    • National Renewable Energy Lab

  • Aaron H Rose

    • National Renewable Energy Laboratory