Resonant surface-enhanced Raman scattering by optical phonons in a monolayer of CdSe nanocrystals on Au nanocluster arrays

Alexander G. Milekhin, Larisa L. Sveshnikova, Tatyana A. Duda, Ekaterina E. Rodyakina, Volodymyr M. Dzhagan, Evgeniya Sheremet, Ovidiu D. Gordan, Cameliu Himcinschi, Alexander V. Latyshev, Dietrich R.T. Zahn

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

Here we present the results on an investigation of resonant Stokes and anti- Stokes surface-enhanced Raman scattering (SERS) by optical phonons in colloidal CdSe nanocrystals (NCs) homogeneously deposited on arrays of Au nanoclusters using the Langmuir-Blodgett technology. The thickness of deposited NCs, determined by transmission and scanning electron microscopy, amounts to approximately 1 monolayer. Special attention is paid to the determination of the localized surface plasmon resonance (LSPR) energy in the arrays of Au nanoclusters as a function of the nanocluster size by means of micro-ellipsometry. SERS by optical phonons in CdSe NCs shows a significant enhancement factor with a maximal value of 2 × 103 which depends resonantly on the Au nanocluster size and thus on the LSPR energy. The deposition of CdSe NCs on the arrays of Au nanocluster dimers enabled us to study the polarization dependence of SERS. It was found that a maximal SERS signal is observed for the light polarization along the dimer axis. Finally, SERS by optical phonons was observed for CdSe NCs deposited on the structures with a single Au dimer. A difference of the LO phonon energy is observed for CdSe NCs on different single dimers. This effect is explained as the confinement-induced shift which depends on the CdSe nanocrystal size and indicates quasi-single NC Raman spectra being obtained.

Original languageEnglish
Pages (from-to)410-417
Number of pages8
JournalApplied Surface Science
Volume370
DOIs
Publication statusPublished - 1 May 2016
Externally publishedYes

Keywords

  • Au dimers
  • Au nanoclusters
  • Cadmium selenide
  • Localized surface plasmon
  • Nanocrystals
  • Phonons
  • Surface-enhanced Raman scattering

ASJC Scopus subject areas

  • Surfaces, Coatings and Films

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  • Cite this

    Milekhin, A. G., Sveshnikova, L. L., Duda, T. A., Rodyakina, E. E., Dzhagan, V. M., Sheremet, E., Gordan, O. D., Himcinschi, C., Latyshev, A. V., & Zahn, D. R. T. (2016). Resonant surface-enhanced Raman scattering by optical phonons in a monolayer of CdSe nanocrystals on Au nanocluster arrays. Applied Surface Science, 370, 410-417. https://doi.org/10.1016/j.apsusc.2016.02.185