Quantum effects in the plasmon response of bimetallic core shell nanostructures

We report a quantum mechanical study of the plasmonic response of bimetallic spherical core/shell nanoparticles. The systems comprise up to 104 electrons and their optical response is addressed with Time Dependent Density Functional Theory calculations. These quantum results are compared with classical electromagnetic calculations for core/shell systems formed by Al/Na, Al/Au and Ag/Na, as representative examples of bimetallic systems. We show that for shell widths in the nanometer range, the system cannot be described as a simple stack of two metals. The finite size effect and the transition layer formed between the core and the shell strongly modify the optical properties of the compound nanoparticle. In particular this configuration leads to a frequency shift of the plasmon resonance with shell character and an increased plasmon decay into electron hole pairs which eventually quenches this resonance for very thin shells. This effect is difficult to capture with a classical theory even upon adjustment of the parameters of a combination of metallic dielectric functions. c (c) 2016 Optical Society of America OCIS codes: (240.6680) Surface plasmons; (250.5403) Plasmonics. References and links 1. J. Lee, P. Hernandez, J. Lee, A. O. Govorov, N. A. Kotov, "Exciton plasmon interactions in molecular spring assemblies of nanowires and wavelength based protein detection,"  6, 291 295 (2007) 2. M. E. Stewart, C. R. Anderton, L. B. Thompson, J. Maria, Stephen K. Gray, J. A. Rogers, and R. G. Nuzzo, "Nanostructured plasmonic sensors,"  (2008) 3. H. Xu, E. Bjeneld, M. Kall, L. Borjesson, "Spectroscopy of single hemoglobin molecules by surface enhanced Raman scattering,"  (1999) 4. C. E. Talley, J. B. Jackson, C. Oubre, N. K. Grady, C. W. Hollars, S. M. Lane, T. R. Huser, P. Nordlander, N. J. Halas, "Surface enhanced Raman scattering from individual Au nanoparticles and nanoparticle dimer substrates,"  (2005) 5. J. Theiss, P. Pavaskar, P. M. Echternach, R. E. Muller, S. B. Cronin, "Plasmonic nanoparticle arrays with nanometer separation for high performance SERS substrates,"  (2010) 6. J. Langer, S. M. Novikov, L. M. Liz Marzan, "Sensing using plasmonic nanostructures and nanoparticles," Nanotechnology 26, 322001 (2015) 7. T. H. Taminiau, F. D. Stefani, F. B. Segerink, N. F. van Hulst, "Optical antennas direct single molecule emission,"  (2008) 8. C. Belacel, B. Habert, F. Bigourdan, F. Marquier, J. P. Hugonin, S. Michaelis de Vasconcellos, X. Lafosse, L. Coolen, C. Schwob, C. Javaux, B. Dubertret, Controlling spontaneous emission with plasmonic optical patch antennas," A. Maitre,  1516 1521 (2013) 9. L. Novotny, N. van Hulst, "Antennas for light,"  (2011) 10. C. D. Lindstrom, X. Y. Zhu, "Photoinduced Electron Transfer at Molecule Metal Interfaces,"  (2006) 11. C. Frischkorn, M. Wolf, "Femtochemistry at Metal Surfaces: Nonadiabatic Reaction Dynamics,"  (2006) 12. S. Linic, U. Aslam, C. Boerigter, M. Morabito, "Photochemical transformations on plasmonic metal nanoparticles,"  14, 567 576 (2015) Vol. 24, No. 21 17 Oct 2016 OPTICS EXPRESS 23941  2016; revised 18 Sep 2016; accepted 22 Sep 2016;  Oct 2016 13. A. Stolz, J. Berthelot, M M Mennemanteuil, G. Colas des Francs, L. Markey, V. Meunier, A. Bouhelier, "Nonlinear Photon Assisted Tunneling Transport in Optical Gap Antennas,"  2330 2338 (2014) 14. J. Berthelot, G. Bachelier, M. Song, P. Rai, G. Colas des Francs, A Dereux, and A Bouhelier, "Silencing and enhancement of second harmonic generation in optical gap antennas," Opt. Express 20, 10498 (2012) 15. T. Hanke, G. Krauss, D. Trautlein, B. Wild, R. Bratschitsch, and A. Leitenstorfer, "Efficient Nonlinear Light Emission of Single Gold Optical Antennas Driven by Few Cycle Near Infrared Pulses,"  (2009) 16. S. Paloma, M. Danckwerts, and L. Novotny, "Nonlinear plasmonics with gold nanoparticle antennas,"  Opt. 11, 114030 (2009) 17. W. Cai, A. P. Vasudev, M. L. Brongersma, "Electrically Controlled Nonlinear Generation of Light with Plasmonics," Science 333, 1720 (2011) 18. A. Bouhelier M. Beversluis, A. Hartschuh, L. Novotny, "Near field second harmonic generation induced by local field enhancement,"  (2003) 19. Kauranen M. Zayats A.V. "Nonlinear plasmonics,"  (2012) 20. R. Alvarez Puebla, L. M. Liz Marzan, F. J. Garcia de Abajo, "Light Concentration at the Nanometer Scale,"  2428 2434 (2010) 21. J. A. Schuller, E. S. Barnard, W. Cai, Y. C. Jun, J. S. White, M. L. Brongersma, "Plasmonics for extreme light concentration and manipulation,"  9, 193 204 (2010) 22. N. J. Halas, S. Lal, W. S. Chang, S. Link, P. Nordlander, "Plasmons in Strongly Coupled Metallic Nanostructures,"  (2011) 23. A. Kuzyk, R. Schreiber, Z. Fan, G. Pardatscher, E. M. Roller, A. Hogele, F. C. Simmel, A. O. Govorov, T. Liedl, "DNA based self assembly of chiral plasmonic nanostructures with tailored optical response,"  (2012) 24. M. B. Cortie, A. M. McDonagh, "Synthesis and optical properties of hybrid and alloy plasmonic Nanoparticles,"  (2011) 25. M. Mayer, L. Scarabelli, K. March, T. Altantzis, M. Tebbe, M. Kociak, S. Bals, F. J. Garcia de Abajo, A. Fery, L. M. Liz Marzan, "Controlled living nanowire growth: precise control over the morphology and optical properties of AgAuAg bimetallic nanowires,"  5437 (2015) 26. B. Goris, G. Guzzinati, C. Fernandez Lopez,  Bals, G. Van Tendeloo, "Plasmon mapping in Au@Ag nanocube assemblies,"  (2014) 27. A. K. Samal, L. Polavarapu, S. Rodal Cedeira, L. M. Liz Marzan, Size tunable Au@Ag core shell nanoparticles: synthesis and surface enhanced raman scattering properties," Langmuir 29, 15076 15082 (2013) 28. L. Chuntonov, M. Bar Sadan, L. Houben, G. Haran, "Correlating electron tomography and plasmon spectroscopy of single noble metal core shell nanoparticles,"  (2012) 29. S. Xing, Y. Feng, Y. Y. Tay, T. Chen, J. Xu, M. Pan, J. He, H. H. Hng, Q. Yan, H. Chen, "Reducing the symmetry of bimetallic Au@Ag nanoparticles by exploiting eccentric polymer shells,"  9539 (2010) 30. R. G. Freeman, M. B. Hommer, K. C. Grabar, M. A. Jackson, M. J. Natan, "Ag Clad Au nanoparticles: novel aggregation, optical, and surface enhanced Raman scattering properties,"  (1996) 31. S. Li, Y. Zhao, Y. Jiang, Y. Zhang, "Preparation and properties of noble metal core/shell nanostructures prepared by excimer laser ablation in liquid solutions," J. Laser Appl. 26, 022001 (2014) 32. R. H. Morris, L. F. Collins, "Optical properties of multilayer colloids,"  (1964) 33. Binary clusters: homogeneous alloys and nucleus shell structures,"  (1993) 34. S. Link, S. L. Wang, and M. A. El Sayed, "Alloy formation of gold silver nanoparticles and the dependence of the plasmon absorption on their composition,"  3533 (1999) 35. M. Moskovits, I. Srnova Sloufova, B. Vlckova, "Bimetallic Ag Au nanoparticles: Extracting meaningful optical constants from the surface plasmon extinction spectrum,"  10446 (2002) 36. P. Mulvaney, M. Giersig, A. Henglein, "Electrochemistry of multilayer colloids: preparation and absorption spectrum of gold coated silver particles,"  (1993) 37. W. Benten, N. Nilius, N. Ernst, H. J. Freund, "Photoemission spectroscopy of single oxide supported Ag Au clusters,"  (2005) 38. A. L. Aden and M. J. Kerker, "Scattering of electromagnetic waves from two concentric spheres,"  (1951) 39. J. Sinzig, M. Quinten, "Scattering and absorption by spherical multilayer particles,"  (1994) 40. H. Xu, "Multilayered metal core shell nanostructures for inducing a large and tunable local optical field,"  (2005) 41. C. E. Roman Velazquez, C. Noguez, "Designing the plasmonic response of shell nanoparticles: spectral representation,"  (2011) 42. M. Arnold, M. Blaber, and M. Ford, "Local plasmon resonances of metal in metal core shells," Optics Express 22, 3186 3198 (2014) Vol. 24, No. 21 17 Oct 2016 OPTICS EXPRESS 23942