Controlling the Spatial and Momentum Distributions of Plasmonic Carriers: Volume vs Surface Effects
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Spatial and momentum distributions of excited charge carriers in nanoplasmonic systems depend sensitively on optical excitation parameters and nanoscale geometry, which therefore control the efficiency and functionality of plasmon-enhanced catalysts, photovoltaics, and nanocathodes. Growing appreciation over the past decade for the different roles of volume- vs surface-mediated excitation in such systems has underscored the need for explicit separation and quantification of these pathways. Toward these ends, we utilize angle-resolved photoelectron velocity map imaging to distinguish these processes in gold nanorods of different aspect ratios down to the spherical limit. Despite coupling to the longitudinal surface plasmon, we find that resonantly excited nanorods always exhibit transverse (sideways) multiphoton photoemission distributions due to photoexcitation within volume field enhancement regions rather than at the tip hot spots. This behavior is accurately reproduced via ballistic Monte Carlo modeling, establishing that volume-excited electrons primarily escape through the nanorod sides. Furthermore, we demonstrate optical control over the photoelectron angular distributions via a screening-induced transition from volume (transverse/side) to surface (longitudinal/tip) photoemission with red detuning of the excitation laser. Frequency-dependent cross sections are separately quantified for these mechanisms by comparison with theoretical calculations, combining volume and surface velocity-resolved photoemission modeling. Based on these results, we identify nanomaterial-specific contributions to the photoemission cross sections and offer general nanoplasmonic design principles for controlling photoexcitation/emission distributions via geometry- and frequency-dependent tuning of the volume vs surface fields.
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Spatial symmetries in plasmonic hot spot regions influence vector momentum distributions of photoexcited carriers, enabling optical generation and active control of directional transient currents down to the nanoscale.
“Corresponding spatial symmetries in these hot spot regions influence the vector momentum distributions of photoexcited carriers187,189,190, leading to new capabilities for optically generating and actively controlling directional transient currents down to the nanoscale.”
From Ultrafast terahertz emission from emerging symmetry-broken materials (2023) · cites this paper as [190]
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Ultrafast terahertz emission from emerging symmetry-broken materials
Pettine, J., Padmanabhan, P., Sirica, N., Prasankumar, R. P., Taylor, A. J., & Chen, H.-T. (2023) · Light: Science & Applications · doi:10.1038/s41377-023-01163-w · Cited by 81 · see citing works
Self-citation
- Authors
- Pettine, J., Meyer, S. M., Medeghini, F., Murphy, C. J., & Nesbitt, D. J.
- Affiliations
- National Institute of Standards and Technology (US)
- University of Illinois Urbana-Champaign (US)
- Corresponding author
- Murphy, Catherine J.
- Nesbitt, David J.
- Venue
- ACS Nano
- Publisher
- American Chemical Society (ACS)
- Published
- 2021-01-11
- Volume
- 15
- Issue
- 1
- Pages
- 1566-1578
- ISSN
- 1936-0851 (ISSN-L)
- 1936-086X
- OpenAlex
- W3043512533
- Cited by
- 24
- References
- 83
- Citations by year
- 2026: 3 · 2025: 2 · 2024: 5 · 2023: 5 · 2022: 5 · 2021: 3 · 2020: 1
- FWCI
- 1.44
- Type
- journal article
- Language
- en
- Open access
- green
- arxiv.org
- Licence
- Locations
- ACS Nano (publishedVersion)
- PubMed (publishedVersion)
- arXiv (Cornell University) (submittedVersion)
- arXiv (Cornell University)
- Funders
- Air Force Office of Scientific Research (FA9550-15-1-0090)
- Topics
- Physical Sciences › Engineering › Biomedical Engineering › Plasmonic and Surface Plasmon Research
- Physical Sciences › Materials Science › Electronic, Optical and Magnetic Materials › Gold and Silver Nanoparticles Synthesis and Applications
- Physical Sciences › Physics and Astronomy › Atomic and Molecular Physics, and Optics › Laser-Matter Interactions and Applications
- Keywords
- nanoplasmonics, gold nanorods, photoelectron velocity-map imaging, photoemission cross section, nanorod aspect ratio
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