Luminescence Enhancement of Lu₃TaO₇:Eu³⁺@Lu₃TaO₇ Red‐Emitting Nanophosphors

Abstract

A series of red-emitting homogeneous Lu 3 TaO 7 :Eu 3+ @ Lu 3 TaO 7 (core-shell) nanoparticles have been successfully synthesised for applications in white-light-emitting diodes (WLEDs). The shell-core ratio (SR) was modulated by the amount of core and shell material which gives a depiction of the effect of SR on luminescence intensity. Powder X-ray diffraction data indicate that the core-shell structures of the nanoparticles are homogeneous in the Fm3m space group. X-ray photoelectron spectroscopy results provide evidence of the core-shell architecture with obvious decreasing amounts[a] States HRTEM images revealed that the external shape of Lu 3 TaO 7 :Eu 3+ @Lu 3 TaO 7 nanoparticles was irregular and the particles were agglomerated. They are uniform in mor-Eur. J. Inorg. Chem. 2015, 690-695

Refined structural studies on the fluorite-related polymorphs of sol–gel undoped and Eu3+-doped yttrium tantalates

“…Once the obtained Y 3 TaO 7 phase is correctly attributed, the broad emission bands can be assigned to Eu 3+ occupying a highly disorder symmetry site in this structure. The emission spectra resembled the emission spectra of Eu 3+ -doped Y 3 NbO 7 51,73 and Lu 3 TaO 7 , 34,74 crystallized as a cubic fluoriterelated structure (space group Fm3 ˉm). If Eu 3+ substitutes Y 3+ in a cubic fluorite-related or pyrochlore (space group Fd3 ˉm) structure (considering the pyrochlore nanodomains observed by Raman), the point group symmetry should be O h (Wyckoff position 4a and 16d for the cubic fluorite-related and pyrochlore structure, respectively).…”

Photoluminescence Enhancement of SiO2‐Coated LaPO4:Eu3+ Inverse Opals by Surface Plasmon Resonance of Ag Nanoparticles

“…For the removing of surface defects, one of the effective solutions is to coat a shell around the nanosized skeleton surface of inverse opal to form inverse opal with shell–core structures. Such a method has been proved to be useful for the PL enhancement of nanocrystal systems . In addition, surface plasmon resonance (SPR) of noble metal NPs is electromagnetic surface modes from collective electron oscillation, which could cause electric field strength enhancement around the NPs, resulting in the enhancement of excitation and emission efficiency of rare earth ions .…”

“…Such a method has been proved to be useful for the PL enhancement of nanocrystal systems. [11][12][13][14][15] In addition, surface plasmon resonance (SPR) of noble metal NPs is electromagnetic surface modes from collective electron oscillation, which could cause electric field strength enhancement around the NPs, resulting in the enhancement of excitation and emission efficiency of rare earth ions. [16][17][18][19][20] In this study, the Ag NPs infilling silica-coated LaPO 4 :Eu 3+ inverse opals were prepared by the sol-gel method, and the influence of the Ag NPs on the PL of silica-coated LaPO 4 :Eu 3+ inverse opals was investigated.…”

Photoluminescence properties of BaSiF6:Eu3+,Eu3+/K+and Eu3+/Tb3+co-doped phosphors

“…6 Recently, Adachi's group reported a series of Mn-activated XSiF 6 (X = NH 4 , K, Zn, Ba) as excellent red phosphors for application in WLED. [7][8][9][10][11][12][13][14][15] BaSiF 6 , with a hexagonal crystal structure, crystallizing in a trigonal symmetry with the space group of R% 3m has attracted significant interest. 8 Some other hexafluorosilicates such as ZnSiF 6 :Mn 4+ 9,10 and similar structure BaTiF 6 :Mn 4+ 11 have also been investigated.…”

“…We attributed the relatively high quenching concentration to the long atomic distance between activators which are occupied the Ba sites. To further enhance the photoluminescence (PL) intensities, we tried a coating process in previous work, 14 therefore, we added K + as a charge compensator this time and discussed the corresponding luminescence properties. These assemblies exhibit a needle-like appearance.…”