Plasmonic nanostructures have been demonstrated as emergent photocatalysts because of their efficient photon absorption and their ability to produce hot carriers. However, the plasmon-generated hot carriers decay through ultrafast relaxation pathways, resulting in a short lifetime that impedes the exploitation of hot carriers for chemical reactions. Charge separation at the heterojunction of the hybrid nanostructures can counteract the ultrafast decay to extend the carrier lifetime. Here, we fabricate hybrid nanostructures composed of gold nanorods and a carbon thin film and demonstrate efficient charge transfer between these two materials. Using single-particle dark-field scattering spectroscopy, we observe a broadening of the longitudinal plasmon for gold nanorods on a carbon film compared to those on a glass substrate. We attribute this plasmon damping to the electron transfer from gold nanorods to the carbon film and exclude the contribution from plasmon-induced resonance energy transfer. The electron transfer efficiencies are calculated as 52.8 ± 4.8 and 57.4 ± 4.0% for carbon films with thicknesses of 10 and 25 nm, respectively. This work demonstrates efficient charge separation at the gold–carbon film interface, which can extend the lifetime of hot carriers to promote plasmonic photocatalysts.
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Electron Energy Loss Spectroscopy of Hot Electron Transport between Gold Nanoantennas and Molybdenum Disulfide by Plasmon Excitation
Hot electron transport from single gold nanoantennas to underlying monolayer molybdenum disulfide (MoS2) is examined using electron energy loss spectroscopy (EELS). EELS allows nanometer‐scale resolution and avoids confounding effects of optical excitation. Experimental EELS measures of plasmon bandwidth in the presence and absence of MoS2are compared with calculated bandwidth contributions from radiative, nonradiative, and interfacial damping. Transport of plasmon hot electrons from 80 nm gold nanospheres to underlying MoS2is estimated. A 6 ± 1% hot electron transport quantum efficiency is inferred from a measured 0.08 eV increase in plasmon damping in the presence of MoS2. Hot electron transport can contribute to reported enhancements in catalysis and photodetection of MoS2decorated with gold nanoantennas. Improved understanding of resonant electric interactions between noble metal nanoantennas and transition metal dichalcogenides can benefit emerging optoelectronics.
more » « less- NSF-PAR ID:
- 10235373
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Optical Materials
- Volume:
- 5
- Issue:
- 3
- ISSN:
- 2195-1071
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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