Enhanced multiple exciton generation in PbS|CdS Janus nanocrystals

ORAL

Abstract

Creating multiple excitons from a single high-energy photon is a promising third generation solar energy conversion strategy. Multiple exciton generation (MEG) is particularly efficient in lead chalcogenide nanocrystals (NCs). A recent study showed that heterostructuring nanocrystals, e.g. by making core-shell NCs, can further enhance MEG.[1] However, in core-shell structures, either the photo-generated hole or the electron is difficult to extract.[2] Here, we show that MEG is as efficient in PbS|CdS Janus NCs as in core-shell ones; however, in Janus NCs both electrons and holes can be easily extracted. We also demonstrate that MEG is retained in conductive Janus-particle arrays, with power conversion efficiencies of nearly 3% in proof-of-principle solar cells. Using first-principles simulations we provide insights into the mechanism enhancing MEG in Janus NCs and we propose design rules for next generation nanostructured solar cells.
[1] C. M. Cirloganu et al., Nat. Commun. 5, 4148 (2014).
[2] F. Giberti, M. Vörös, and G. Galli, Nano Lett. 17, 2547 (2017).

*Work supported by Aneesur Rahman Fellowship (MV); CASP, an EFRC funded by the U.S. DOE BES; DOE No. DE-FG02-06ER46262; and MICCoM, as part of the Computational Materials Sciences Program funded by U.S. DOE BES.

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Presenters

  • Marton Voeroes

    • Materials Science Division, Argonne National Laboratory
    • University of Chicago; Argonne National Laboratory
    • MSD, Argonne National Laboratory

Authors

  • Marton Voeroes

    • Materials Science Division, Argonne National Laboratory
    • University of Chicago; Argonne National Laboratory
    • MSD, Argonne National Laboratory

  • Daniel Kroupa

    • Chemistry & Nanoscience Center, National Renewable Energy Laboratory, Golden, CO, United States and Department of Chemistry and Biochemistry, University of Colorado Boulder

  • Gregory Pach

    • Chemistry & Nanoscience Center, National Renewable Energy Laboratory, Golden, CO, United States and Department of Physics, Colorado School of Mines

  • Federico Giberti

    • Institute for Molecular Engineering, University of Chicago
    • Institute for Molecular Engineering, Univ of Chicago

  • Ryan Crisp

    • Chemistry & Nanoscience Center, National Renewable Energy Laboratory, Golden, CO, United States and Department of Physics, Colorado School of Mines

  • Boris Chernomordik

    • Chemistry & Nanoscience Center, National Renewable Energy Laboratory

  • Arthur Nozik

    • Chemistry & Nanoscience Center, National Renewable Energy Laboratory, Golden, CO, United States and Department of Chemistry and Biochemistry, University of Colorado Boulder

  • Justin Johnson

    • Chemistry & Nanoscience Center, National Renewable Energy Laboratory

  • Rohan Singh

    • Chemistry Division, Los Alamos National Laboratory

  • Victor Klimov

    • Chemistry Division, Los Alamos National Laboratory

  • Giulia Galli

    • Institute for Molecular Engineering, University of Chicago
    • Univ of Chicago
    • University of Chicago
    • Institute for Molecular Engineering, University of Chicago; Argonne National Laboratory
    • Institute for Molecular Engineering, University of Chicago, Chicago, IL, United States and Materials Science Division, Argonne National Laboratory
    • University of Chicago; Argonne National Laboratory
    • Institute for Molecular Engineering, Univ of Chicago

  • Matthew Beard

    • Chemistry & Nanoscience Center, National Renewable Energy Laboratory