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Hot Carrier Dynamics in Photoexcited Gold Nanostructures: Role of Interband Excitations and Evidence for Ballistic Transport

Tagliabue, Giulia and Jermyn, Adam S. and Sundararaman, Ravishankar and Welch, Alex J. and DuChene, Joseph S. and Davoyan, Artur R. and Narang, Prineha and Atwater, Harry A. (2017) Hot Carrier Dynamics in Photoexcited Gold Nanostructures: Role of Interband Excitations and Evidence for Ballistic Transport. . (Submitted) http://resolver.caltech.edu/CaltechAUTHORS:20171023-104952776

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Abstract

Harnessing short-lived photoexcited electron-hole pairs in metal nanostructures has the potential to define a new phase of optoelectronics, enabling control of athermal mechanisms for light harvesting, photodetection and photocatalysis. To date, however, the spatiotemporal dynamics and transport of these photoexcited carriers have been only qualitatively characterized. Plasmon excitation has been widely viewed as an efficient mechanism for generating non-thermal hot carriers. Despite numerous experiments, conclusive evidence elucidating and quantifying the full dynamics of hot carrier generation, transport, and injection has not been reported. Here, we combine experimental measurements with coupled first-principles electronic structure theory and Boltzmann transport calculations to provide unprecedented insight into the internal quantum efficiency, and hence internal physics, of hot carriers in photoexcited gold (Au)-gallium nitride (GaN) nanostructures. Our results indicate that photoexcited electrons generated in 20 nm-thick Au nanostructures impinge ballistically on the Au-GaN interface. This discovery suggests that the energy of hot carriers could be harnessed from metal nanostructures without substantial losses via thermalization. Measurements and calculations also reveal the important role of metal band structure in hot carrier generation at energies above the interband threshold of the plasmonic nanoantenna. Taken together, our results advance the understanding of excited carrier dynamics in realistically-scaled metallic nanostructures and lay the foundations for the design of new optoelectronic devices that operate in the ballistic regime.


Item Type:Report or Paper (Discussion Paper)
Related URLs:
URLURL TypeDescription
https://arxiv.org/abs/1708.02187arXivDiscussion Paper
ORCID:
AuthorORCID
Sundararaman, Ravishankar0000-0002-0625-4592
Narang, Prineha0000-0003-3956-4594
Atwater, Harry A.0000-0001-9435-0201
Additional Information:This material is based upon work performed by the Joint Center for Artificial Photosynthesis, a DOE Energy Innovation Hub, supported through the Office of Science of the U.S. Department of Energy under Award No. DE-SC0004993. R.S., A.S.J., and P.N. acknowledge support from NG NEXT at Northrop Grumman Corporation. Calculations in this work used the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. A.D. and H.A.A. acknowledge support from the Air Force Office of Scientific Research under grant FA9550-16-1-0019. G.T. acknowledges support from the Swiss National Science Foundation through the Early Postdoc Mobility Fellowship, grant n. P2EZP2_159101. P.N. acknowledges support from the Harvard University Center for the Environment (HUCE). A.S.J. thanks the UK Marshall Commission and the US Goldwater Scholarship for financial support. AJW acknowledges support from the National Science Foundation (NSF) under Award No. 2016217021.
Group:JCAP, Resnick Sustainability Institute, Kavli Nanoscience Institute
Funders:
Funding AgencyGrant Number
Department of Energy (DOE)DE-SC0004993
Northrop Grumman CorporationUNSPECIFIED
Department of Energy (DOE)DE-AC02-05CH11231
Air Force Office of Scientific Research (AFOSR)FA9550-16-1-0019
Swiss National Science Foundation (SNSF)P2EZP2_159101
Harvard UniversityUNSPECIFIED
Marshall CommissionUNSPECIFIED
Barry M. Goldwater ScholarshipUNSPECIFIED
NSF2016217021
Record Number:CaltechAUTHORS:20171023-104952776
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20171023-104952776
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:82579
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:24 Oct 2017 19:19
Last Modified:15 Nov 2017 00:00

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