UV, Blue, Green, Yellow, Red, and Small: Newest Developments on Eu2+-Doped Nanophosphors

Novel multi-functional europium-doped gadolinium oxide nanoparticle aerosols facilitate the study of deposition in the developing rat lung

Ambient ultrafine particulate matter (UPM), less than 100 nm in size, has been linked to the development and exacerbation of pulmonary diseases. Age differences in susceptibility to UPM may be due to a difference in delivered dose as well as age-dependent differences in lung biology and clearance. In this study, we developed and characterized aerosol exposures to novel metal oxide nanoparticles containing lanthanides to study particle deposition in the developing postnatal rat lung. Neonatal, juvenile and adult rats (1, 3 and 12 weeks old) were nose only exposed to 380 μg m(-3) of ∼30 nm europium doped gadolinium oxide nanoparticles (Gd2O3:Eu(3+)) for 1 h. The deposited dose in the nose, extrapulmonary airways and lungs was determined using inductively-coupled plasma mass spectroscopy. The dose of deposited particles was significantly greater in the juvenile rats at 2.22 ng per g body weight compared to 1.47 ng per g and 0.097 ng per g for the adult and neonate rats, respectively. Toxicity was investigated in bronchoalveolar lavage fluid (BALF) by quantifying recovered cell types, and measuring lactate dehydrogenase activity and total protein. The toxicity data suggests that the lanthanide particles were not acutely toxic or inflammatory with no increase in neutrophils or lactate dehydrogenase activity at any age. Juvenile and adult rats had the same mass of deposited NPs per gram of lung tissue, while neonatal rats had significantly less NPs deposited per gram of lung tissue. The current study demonstrates the utility of novel lanthanide-based nanoparticles to study inhaled particle deposition in vivo and has important implications for nanoparticles delivery to the developing lung either as therapies or as a portion of particulate matter air pollution.

Synthesis and Luminescence Properties of Novel Ce(3+)- and Eu(2+)-Doped Lanthanum Bromothiosilicate La3Br(SiS4)2 Phosphors for White LEDs

Novel Ce(3+)- and Eu(2+)-doped lanthanum bromothiosilicate La3Br(SiS4)2:Ce(3+)and La3Br(SiS4)2:Eu(2+) phosphors were prepared by solid-state reaction in an evacuated and sealed quartz glass ampule. The La3Br(SiS4)2:Ce(3+) phosphor generates a cyan emission upon excitation at 375 nm, whereas the La3Br(SiS4)2:Eu(2+) phosphor could be excited with extremely broad range from UV to blue region (300 to 600 nm) and generates a reddish-orange broadband emission centered at 640 nm. In addition, thermal luminescence properties of La3Br(SiS4)2:Ce(3+)and La3Br(SiS4)2:Eu(2+) phosphors from 20 to 200 °C were investigated. The combination of a 450 nm blue InGaN-based LED chip with the red-emitting La3Br(SiS4)2:Eu(2+) phosphor, and green-emitting BOSE:Eu(2+) commercial phosphor produced a warm-white light with the CRI value of ∼95 and the CCT of 5,120 K. Overall, these results show that the prepared phosphors may have potential applications in pc-WLED.

Controllable Eu valence for photoluminescence tuning in apatite-typed phosphors by the cation cosubstitution effect

A schematic presentation for the valence transition from 3+ to 2+ of Eu in Ca_2(1+x)La_8(1−x)(SiO₄)_6−x(PO₄)_xO₂:Eu (0 ≤ x ≤ 6) based on the XANES spectroscopy analysis.

Development of a new in situ analysis technique applying luminescence of local coordination sensors: principle and application for monitoring metal-ligand exchange processes

In situluminescence analysis of coordination sensors (ILACS) allows studying metal-ligand exchange processes in a fast, sensitive and broadly available fashion.

Near-white emission observed in Dy doped AlN

Dy doped AlN phosphors were prepared by a simple solid state route, exhibiting excellent photoluminescence.

Controlled synthesis of CaTiO3:Ln3+ nanocrystals for luminescence and photocatalytic hydrogen production

Bifunctional CaTiO₃:Ln³⁺ nanocrystals not only can show very stable luminescence properties and a much higher quenching concentration due to the scheelite related structure of CaTiO₃, but also can exhibit a higher activity for hydrogen production.

Small-size and monodispersed red-emitting Pr3+ doped barium molybdate nanocrystals with ultrahigh color purity

Small-size and monodispersed BaMoO₄:Pr³⁺ nanocrystals (NCs) have been prepared by a simple and efficient liquid–solid–solution method. These NCs exhibit narrow-linewidth emission (only ∼4 nm) with high spectral purity in red.

Photoluminescence properties of Yb2+ ions doped in the perovskites CsCaX3 and CsSrX3 (X = Cl, Br, and I) – a comparative study

Photoluminescence spectra of Yb²⁺ ions doped into CsCaX₃ and CsSrX₃ (X = Cl, Br, and I) depict a manifold of transitions in high resolution, which allows a detailed understanding of the optical properties of divalent lanthanide ions in perovskite host lattices.

S. Eu2+ luminescence in Ca3Si2O7 and spectral widening and tuning of Eu2+ emission color (orangish-red to green) by crystal chemical substitution

The newly synthesized solid solution is capable converting the near UV or blue ray in to orangish-yellow to green.

Long persistent phosphors—from fundamentals to applications

We present multidisciplinary research on synthetic methods, afterglow mechanisms, characterization techniques, material kinds, and applications of long persistent phosphors.

Structural evolution induced preferential occupancy of designated cation sites by Eu2+ in M5(Si3O9)2 (M = Sr, Ba, Y, Mn) phosphors

A schematic presentation for the unexpected blue-shifted luminescence of Eu²⁺ in M₅(Si₃O₉)₂ (M = Sr, Ba, Y, Eu, Mn) based on the preferential occupancy at the designated cation sites.