Anomalous ultrafast dynamics of hot plasmonic electrons in nanostructures with hot spots


The interaction of light and matter in metallic nanosystems is mediated by the collective oscillation of surface electrons, called plasmons1. After excitation, plasmons are absorbed by the metal electrons through inter- and intraband transitions, creating a highly non-thermal distribution of electrons2,3,4. The electron population then decays through electron–electron interactions, creating a hot electron distribution within a few hundred femtoseconds, followed by a further relaxation via electron–phonon scattering on the timescale of a few picoseconds5,6,7,8. In the spectral domain, hot plasmonic electrons induce changes to the plasmonic resonance of the nanostructure by modifying the dielectric constant of the metal5,9. Here, we report on the observation of anomalously strong changes to the ultrafast temporal and spectral responses of these excited hot plasmonic electrons in hybrid metal/oxide nanostructures as a result of varying the geometry and composition of the nanostructure and the excitation wavelength. In particular, we show a large ultrafast, pulsewidth-limited contribution to the excited electron decay signal in hybrid nanostructures containing hot spots. The intensity of this contribution correlates with the efficiency of the generation of highly excited surface electrons. Using theoretical models, we attribute this effect to the generation of hot plasmonic electrons from hot spots. We then develop general principles to enhance the generation of energetic electrons through specifically designed plasmonic nanostructures that could be used in applications where hot electron generation is beneficial, such as in solar photocatalysis, photodetectors and nonlinear devices10,11,12,13,14,15,16,17,18,19.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Schematic of the experimental configuration and spectral properties of the plasmonic nanodisks.
Figure 2: Pump–probe reflection data of gold nanodisks.
Figure 3: Pump–probe reflection data of gold nanodisks with a TiO2 spacer layer.
Figure 4: Electromagnetic field and energetic charge distribution calculations.


  1. 1

    Novotny, L. & van Hulst, N. F. Antennas for light. Nature Photon. 5, 83–90 (2011).

    CAS  Article  Google Scholar 

  2. 2

    Hartland, G. V. Optical studies of dynamics in noble metal nanostructures. Chem. Rev. 111, 3858–3887 (2011).

    CAS  Article  Google Scholar 

  3. 3

    Voisin, C., Fatti, N. D., Christofilos, D. & Vallee, F. Ultrafast electron dynamics and optical nonlinearities in metal nanoparticles. J. Phys. Chem. B 105, 2264–2280 (2001).

    CAS  Article  Google Scholar 

  4. 4

    Manjavacas, A., Liu, J. G., Kulkarni, V. & Nordlander, P. Plasmon-induced hot carriers in metallic nanoparticles. ACS Nano 8, 7630–7638 (2014).

    CAS  Article  Google Scholar 

  5. 5

    Baida, H. et al. Ultrafast nonlinear optical response of a single gold nanorod near its surface plasmon resonance. Phys. Rev. Lett. 107, 057402 (2011).

    CAS  Article  Google Scholar 

  6. 6

    Pelton, M., Liu, M., Park, S., Scherer, N. F. & Guyot-Sionnest, P. Ultrafast resonant optical scattering from single gold nanorods: large nonlinearities and plasmon saturation. Phys. Rev. B 73, 155419 (2006).

    Article  Google Scholar 

  7. 7

    Park, S., Pelton, M., Liu, M., Guyot-Sionnest, P. & Scherer, N. F. Ultrafast resonant dynamics of surface plasmons in gold nanorods. J. Phys. Chem. C 111, 116–123 (2007).

    CAS  Article  Google Scholar 

  8. 8

    Zavelani-Rossi, M. et al. Transient optical response of a single gold nanoantenna: the role of plasmon detuning. ACS Photon. 2, 521–529 (2015).

    CAS  Article  Google Scholar 

  9. 9

    Inouye, H., Tanaka, K., Tanahashi, I. & Hirao, K. Ultrafast dynamics of nonequilibrium electrons in a gold nanoparticle system. Phys. Rev. B 57, 11334 (1998).

    CAS  Article  Google Scholar 

  10. 10

    Knight, M. W., Sobhani, H., Nordlander, P. & Halas, N. J. Photodetection with active optical antennas. Science 332, 702–704 (2011).

    CAS  Article  Google Scholar 

  11. 11

    Dani, K. M. et al. Subpicosecond optical switching with a negative index metamaterial. Nano Lett. 9, 3565–3569 (2009).

    CAS  Article  Google Scholar 

  12. 12

    Chen, P.-Y. & Alù, A. Optical nanoantenna arrays loaded with nonlinear materials. Phys. Rev. B 82, 235405 (2010).

    Article  Google Scholar 

  13. 13

    Mukherjee, S. et al. Hot electrons do the impossible: plasmon-induced dissociation of H2 on Au. Nano Lett. 13, 240–247 (2013).

    CAS  Article  Google Scholar 

  14. 14

    Cushing, S. K. et al. Photocatalytic activity enhanced by plasmonic resonant energy transfer from metal to semiconductor. J. Am. Chem. Soc. 134, 15033–15041 (2012).

    CAS  Article  Google Scholar 

  15. 15

    Abb, M., Wang, Y., de Groot, C. H. & Muskens, O. L. Hotspot-mediated ultrafast nonlinear control of multifrequency plasmonic nanoantennas. Nature Commun. 5, 4869 (2014).

    CAS  Article  Google Scholar 

  16. 16

    Schumacher, T. et al. Nanoantenna-enhanced ultrafast nonlinear spectroscopy of a single gold nanoparticle. Nature Commun. 2, 333 (2011).

    Article  Google Scholar 

  17. 17

    Chen, K.-P., Drachev, V. P., Borneman, J. D., Kildishev, A. V. & Shalaev, V. M. Drude relaxation rate in grained gold nanoantennas. Nano Lett. 10, 916–922 (2010).

    CAS  Article  Google Scholar 

  18. 18

    Appavoo, K. et al. Ultrafast phase transition via catastrophic phonon collapse driven by plasmonic hot-electron injection. Nano Lett. 14, 1127–1133 (2014).

    CAS  Article  Google Scholar 

  19. 19

    Nishijima, Y. et al. Near-infrared plasmon-assisted water oxidation. J. Phys. Chem. Lett. 3, 1248–1252 (2012).

    CAS  Article  Google Scholar 

  20. 20

    Mühlschlegel, P., Eisler, H.-J., Martin, O. J. F., Hecht, B. & Pohl, D. W. Resonant optical antennas. Science 308, 1607–1609 (2005).

    Article  Google Scholar 

  21. 21

    Morton, S. M., Silverstein, D. W. & Jensen, L. Theoretical studies of plasmonics using electronic structure methods. Chem. Rev. 111, 3962–3994 (2011).

    CAS  Article  Google Scholar 

  22. 22

    Ciraci, C. et al. Probing the ultimate limits of plasmonic enhancement. Science 337, 1072–1074 (2012).

    CAS  Article  Google Scholar 

  23. 23

    Rose, A. et al. Control of radiative processes using tunable plasmonic nanopatch antennas. Nano Lett. 14, 4797–4802 (2014).

    CAS  Article  Google Scholar 

  24. 24

    Mertens, J. et al. Controlling sub-nm gaps in plasmonic dimers using graphene. Nano Lett. 13, 5033–5038 (2013).

    CAS  Article  Google Scholar 

  25. 25

    Zhang, H. & Govorov, A. O. Optical generation of hot plasmonic carriers in metal nanocrystals: the effects of shape and field enhancement. J. Phys. Chem. C 118, 7606–7614 (2014).

    CAS  Article  Google Scholar 

  26. 26

    Clavero, C. Plasmon-induced hot-electron generation at nanoparticle/metal-oxide interfaces for photovoltaic and photocatalytic devices. Nature Photon. 8, 95–103 (2014).

    CAS  Article  Google Scholar 

  27. 27

    Tian, Y. & Tatsuma, T. Mechanisms and applications of plasmon-induced charge separation at TiO2 films loaded with gold nanoparticles. J. Am. Chem. Soc. 127, 7632–7637 (2005).

    CAS  Article  Google Scholar 

  28. 28

    Furube, A., Du, L., Hara, K., Katoh, R. & Tachiya, M. Ultrafast plasmon-induced electron transfer from gold nanodots into TiO2 nanoparticles. J. Am. Chem. Soc. 129, 14852–14853 (2007).

    CAS  Article  Google Scholar 

  29. 29

    Govorov, A., Zhang, H., Demir, V. & Gunko, Y. K. Photogeneration of hot plasmonic electrons with metal nanocrystals: quantum description and potential applications. Nano Today 9, 85–101 (2014).

    CAS  Article  Google Scholar 

  30. 30

    Govorov, A. O. & Zhang, H. Kinetic density functional theory for plasmonic nanostructures: breaking of the plasmon peak in the quantum regime and generation of hot electrons. J. Phys. Chem. C 119, 6181–6194 (2015).

    CAS  Article  Google Scholar 

  31. 31

    Palik, E. D. Handbook of Optical Constants of Solids (Academic, 1985).

    Google Scholar 

Download references


This work was performed, in part, at the Center for Nanoscale Materials, a US Department of Energy, Office of Science, Office of Basic Energy Sciences User Facility under contract no. DE-AC02-06CH11357. Work by A.B.F.M. was supported by the Argonne–Northwestern Solar Energy Research (ANSER) Center, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science, Office of Basic Energy Sciences under award no. DE-SC0001059. A.O.G. and L.K.K. acknowledge support from the Volkswagen Foundation and the US Army Research Office (W911NF-12-1-0407). The authors thank L. Ocola and R. Divan for their invaluable help with fabrication instruments and processes.

Author information




H.H. and G.P.W. designed and carried out the experiments. L.K.K., L.V.B. and A.O.G. performed the theoretical modelling and analysis. H.H., A.B.F.M. and D.R. fabricated the samples. H.H., A.O.G. and G.P.W. interpreted the results and wrote the manuscript, with contributions from all the authors.

Corresponding authors

Correspondence to Hayk Harutyunyan or Alexander O. Govorov or Gary P. Wiederrecht.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary information

Supplementary Information (PDF 1824 kb)

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Harutyunyan, H., Martinson, A., Rosenmann, D. et al. Anomalous ultrafast dynamics of hot plasmonic electrons in nanostructures with hot spots. Nature Nanotech 10, 770–774 (2015).

Download citation

Further reading


Find nanotechnology articles, nanomaterial data and patents all in one place. Visit Nano by Nature Research