Blueshift of the surface plasmon resonance in silver nanoparticles studied with EELS

Nanophotonics

article

Søren Raza¹  Nicolas Stenger¹  Shima Kadkhodazadeh²  Søren V. Fischer⁵  Natalie Kostesha⁵  Antti-Pekka Jauho⁴  Andrew Burrows²  Martijn Wubs¹  N. Asger Mortensen¹ 

[1] Department of Photonics Engineering, Technical University of Denmark;Center for Electron Nanoscopy, Technical University of Denmark;Both authors contributed equally.;Center for Nanostructured Graphene (CNG), Technical University of Denmark;Department of Micro and Nanotechnology, Technical University of Denmark

关键词: Electron energy loss spectroscopy;    nonlocal response;    plasmonics;   

DOI  :  10.1515/nanoph-2012-0032

学科分类：社会科学、人文和艺术（综合）

来源: De Gruyter

【 摘 要 】

We study the surface plasmon (SP) resonance energy of isolated spherical Ag nanoparticles dispersed on a silicon nitride substrate in the diameter range 3.5–26 nm with monochromated electron energy-loss spectroscopy. A significant blueshift of the SP resonance energy of 0.5 eV is measured when the particle size decreases from 26 down to 3.5 nm. We interpret the observed blueshift using three models for a metallic sphere embedded in homogeneous background material: a classical Drude model with a homogeneous electron density profile in the metal, a semiclassical model corrected for an inhomogeneous electron density associated with quantum confinement, and a semiclassical nonlocal hydrodynamic description of the electron density. We find that the latter two models provide a qualitative explanation for the observed blueshift, but the theoretical predictions show smaller blueshifts than observed experimentally.

【 授权许可】

CC BY