Regensburg 2010 – scientific programme
Parts | Days | Selection | Search | Downloads | Help
CPP: Fachverband Chemische Physik und Polymerphysik
CPP 39: Glasses and Glass Transition II (jointly with DY and DF)
CPP 39.11: Talk
Thursday, March 25, 2010, 12:15–12:30, H38
Raman spectroscopy on barium halide nanoparticles in fluorozirconate-based glasses — •Charlotte Pfau1, Paul-Tiberiu Miclea2,3, and Stefan Schweizer1,2 — 1Centre for Innovation Competence SiLi-nano®, Martin Luther University of Halle-Wittenberg, Karl-Freiherr-von-Fritsch-Str. 3, 06120 Halle (Saale) — 2Fraunhofer Center for Silicon Photovoltaics, Walter-Hülse-Str. 1, 06120 Halle (Saale) — 3Institute of Physics, Martin Luther University of Halle-Wittenberg, Heinrich-Damerow-Str. 4, 06120 Halle (Saale)
Rare-earth(RE) doped fluorozirconate-based glasses show enhanced fluorescence properties when they are additionally doped with Cl or Br ions, which initiate the growth of BaCl2 or BaBr2 nanocrystals, respectively, upon thermal processing. The REs are incorporated into the nanocrystals during the annealing procedure enabling a strong fluorescence upon excitation. A critical parameter for the fluorescence efficiency is the non-radiative decay process from the excited to the ground state. Non-radiative decay processes are determined by the phonon energies of the host system. Low phonon energy systems such as BaCl2 or BaBr2 are desirable hosts for fluorescent ions. The size and structural phase of the nanocrystals depend significantly on the heating conditions; consequently, a series of chlorine- or bromine-doped fluorozirconate-based glasses were analyzed to determine their phonon energy spectra by Raman spectroscopy. For comparison, the phonon spectra of bulk BaCl2, and BaBr2 were investigated.