TY - JOUR

T1 - Probing Bidirectional Plasmon-Plasmon Coupling-Induced Hot Charge Carriers in Dual Plasmonic Au/CuS Nanocrystals

AU - Bessel, Patrick

AU - Niebur, André

AU - Kranz, Daniel

AU - Lauth, Jannika

AU - Dorfs, Dirk

N1 - Funding Information: P.B. and A.N. contributed equally to this work. The authors would like to thank Armin Feldhoff for providing the XRD facility. P.B. is grateful for being funded by the Hannover School for Nanotechnology (HSN). D.D. thanks the Deutsche Forschungsgemeinschaft for the DFG Research Grant 1580/5‐1. D.D. and J.L. are thankful for funding by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany's Excellence Strategy within the Cluster of Excellence PhoenixD (EXC2122, Project ID 390833453) and access to the Ti:sapphire amplifier system (major equipment DFG, Project ID 231415720, Michael Oestreich, Jens Hübner). J.L. is grateful for funding through the Caroline Herschel program of Leibniz Universität Hannover. D.K. is grateful for funding by the Konrad‐Adenauer‐Stiftung (KAS). Open access funding enabled and organized by Projekt DEAL.

PY - 2023/3/22

Y1 - 2023/3/22

N2 - Heterostructured Au/CuS nanocrystals (NCs) exhibit localized surface plasmon resonance (LSPR) centered at two different wavelengths (551 and 1051 nm) with a slight broadening compared to respective homostructured Au and CuS NC spectra. By applying ultrafast transient absorption spectroscopy we show that a resonant excitation at the respective LSPR maxima of the heterostructured Au/CuS NCs leads to the characteristic hot charge carrier relaxation associated with both LSPRs in both cases. A comparison of the dual plasmonic heterostructure with a colloidal mixture of homostructured Au and CuS NCs shows that the coupled dual plasmonic interaction is only active in the heterostructured Au/CuS NCs. By investigating the charge carrier dynamics of the process, we find that the observed interaction is faster than phononic or thermal processes (< 100 fs). The relaxation of the generated hot charge carriers is faster for heterostructured nanocrystals and indicates that the interaction occurs as an energy transfer (we propose Landau damping or interaction via LSPR beat oscillations as possible mechanisms) or charge carrier transfer between both materials. Our results strengthen the understanding of multiplasmonic interactions in heterostructured Au/CuS NCs and will significantly advance applications where these interactions are essential, such as catalytic reactions.

AB - Heterostructured Au/CuS nanocrystals (NCs) exhibit localized surface plasmon resonance (LSPR) centered at two different wavelengths (551 and 1051 nm) with a slight broadening compared to respective homostructured Au and CuS NC spectra. By applying ultrafast transient absorption spectroscopy we show that a resonant excitation at the respective LSPR maxima of the heterostructured Au/CuS NCs leads to the characteristic hot charge carrier relaxation associated with both LSPRs in both cases. A comparison of the dual plasmonic heterostructure with a colloidal mixture of homostructured Au and CuS NCs shows that the coupled dual plasmonic interaction is only active in the heterostructured Au/CuS NCs. By investigating the charge carrier dynamics of the process, we find that the observed interaction is faster than phononic or thermal processes (< 100 fs). The relaxation of the generated hot charge carriers is faster for heterostructured nanocrystals and indicates that the interaction occurs as an energy transfer (we propose Landau damping or interaction via LSPR beat oscillations as possible mechanisms) or charge carrier transfer between both materials. Our results strengthen the understanding of multiplasmonic interactions in heterostructured Au/CuS NCs and will significantly advance applications where these interactions are essential, such as catalytic reactions.

KW - hot charge carrier relaxation

KW - localized surface plasmon resonance

KW - localized surface plasmon resonance (LSPR)

KW - transient absorption spectroscopy

KW - ultrafast dynamics

UR - http://www.scopus.com/inward/record.url?scp=85146317487&partnerID=8YFLogxK

U2 - 10.48550/arXiv.2210.11144

DO - 10.48550/arXiv.2210.11144

M3 - Article

AN - SCOPUS:85146317487

VL - 19

JO - SMALL

JF - SMALL

SN - 1613-6810

IS - 12

M1 - 2206379

ER -