Abstract
The photoemission enhancement with local surface plasmon resonance (LSPR) was studied by two-photon photoemission (2PPE) spectroscopy for size-selected silver (Ag) and gold (Au) metal nanoparticles (NPs) deposited on a hydrogen-terminated Si(111)-(1 × 1) [H-Si(111)] surface. At 0.0015 monolayer equivalents (MLE) of Ag NPs, the photoemission enhancement was observed at a photon energy of 3.10 eV, which corresponds to the peak energy for the LSPR of isolated Ag NPs. A surface with around 0.005 MLE LSPR of size-selected Ag NPs exhibited three- and four-photon photoemission processes, implying monodispersed Ag NPs on H-Si(111). This enhancement could not be observed for Au NP deposition, even at 1.0 MLE in the photon energy range of 2.90-3.23 eV. Taking into account the polarization and photoemission-angle dependences, the photoemission enhancement could be accounted for by a mechanism involving the near-fields induced by the LSPR of Ag NPs. This mechanism is consistent with an analysis based on the effect of the interparticle distance between Ag NPs on the near-field intensity and polarization.
| Original language | English |
|---|---|
| Pages (from-to) | 16270-16277 |
| Number of pages | 8 |
| Journal | Journal of Physical Chemistry C |
| Volume | 114 |
| Issue number | 39 |
| DOIs | |
| Publication status | Published - 2010 Oct 7 |
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Energy(all)
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films