Transient charge trapping in Eu3+-doped nanocomposites by ultrafast laser excitation

Huimin Liu, Sergie Lysenko, Jose Jimenez, Valentin Vikhnin

Research output: Contribution to journalArticle

Abstract

Eu3+ was incorporated as probe ions into nanocomposite glasses, such as metal silver doped phosphate glass and crystalline nanocomposites Sienriched SiO2 glass. Luminescence studies show that the doped europium ions are present as trivalent Eu3+, and are distributed in the matrix on the boundary surface of nanoparticles. The valence switching from Eu3+ to Eu2+ was observed in Si-SiO2 nanocomposites when ultrafast laser excitation was applied. In silver metal nanoparticles embedded alummophosphate glass, a time-resolved ultrafast degenerate-four-wave-mixing (DFWM) experiment shows enhanced third-order nonlinearity at zero-delay time, followed by a bell-like signal buildup. It is attributed to the creation of electronic polaron and vibronic Wannier-Mott exciton (WME). In europium codoped sample, however, the bell-like signal is depressed. All the above observations are interpreted as the result of a strong Coulomb interaction between conduction electrons produced inside the nanoparticles by laser excitation and Eu3+ ions residing near the boundary surface. The trivalent europium ions play the role as positive charges attracting electrons. This results in temporary formation of Eu2+, and blocks the resonant tunneling transition in the silver-glass system to avoid creating large radius polaron.

Original languageEnglish (US)
Pages (from-to)663-667
Number of pages5
JournalJournal of Rare Earths
Volume24
Issue number6
DOIs
StatePublished - Dec 2006
Externally publishedYes

Keywords

  • Europium
  • Excitation
  • Nanocomposite
  • Rare earths
  • Ultrafast

ASJC Scopus subject areas

  • Chemistry(all)
  • Geochemistry and Petrology

Fingerprint Dive into the research topics of 'Transient charge trapping in Eu<sup>3+</sup>-doped nanocomposites by ultrafast laser excitation'. Together they form a unique fingerprint.

  • Cite this