CeF3-based glass ceramic: a potential luminescent host for white-light-emitting diode.

Rare earth (RE) ion doped glass ceramics containing hexagonal CeF(3) nanocrystals with a mean size of 12 nm were fabricated. Using Eu(3+) as the structural probe, Stark splitting emissions and the low forced electric dipole D5(0)-->F7(2) transition of Eu(3+) revealed the partition of RE ions into low-phonon-energy CeF(3) nanocrystals. Efficient energy transfers from Ce(3+) to Tb(3+) or Dy(3+) were found, and the energy transfer efficiency was evaluated. Under ultraviolet excitation, intense white-light emission was observed in Dy(3+)-doped samples owing to Dy(3+) resided in CeF(3) crystalline environment, indicating their potential application in white-light-emitting diodes.

Enhanced photoluminescence of Eu(3+) induced by energy transfer from In(2)O(3) nano-crystals embedded in glassy matrix.

Eu(3+)-doped transparent glass ceramics containing In(2)O(3) nano-crystals were prepared by melt quenching and subsequent heating. X-ray diffraction analysis, transmission electron microscope observation, and photoluminescence excitation spectra demonstrated that In(2)O(3) nano-particles sized 3-6 nm homogenously distributed among the glass matrix. Under excitation of these nano-particles, Eu(3+) luminescence was found greatly enhanced due to the energy transfer from the oxygen-vacancy-related defects of In(2)O(3) to Eu(3+) ions. The Eu(3+) content dependent energy transfer efficiency was evaluated, and the value reached 67% for 1 mol% Eu(3+) doped glass ceramics. Low temperature emission spectra demonstrated that the Eu(3+) ions of the glass ceramic locate mainly in the glass matrix.

Near-infrared quantum cutting in transparent nanostructured glass ceramics.

Quantum cutting downconversion involving the emission of two near-infrared photons for each blue photon absorbed is realized in transparent glass ceramics with embedded Pr3+/Yb3+: beta-YF3 nanocrystals. On excitation of Pr3+ ions with a visible photon at 482 nm, Yb3+ ions emit two near-infrared photons at 976 nm through an efficient cooperative energy transfer from Pr3+ to Yb3+, with optimal quantum efficiency close to 200%. The development of the near-infrared quantum cutting transparent glass ceramic could open a route to enhance the energy efficiency of the silicon solar cell by converting one blue solar photon to two near-infrared ones.