Low temperature synthesis and luminescence properties of re-dispersible Eu3+ doped LaPO4 nanorods by ethylene glycol route

Preparation and its luminescent properties of AlPO4:Eu3+ phosphor for w-LED applications

“…In all the samples the asymmetric ratio values are found to be less than unity indicating the occupation of more Eu 3+ ions at inversion symmetry site. Similar observation was reported on Eu 3+ doped LnPO 4 (Ln = Y, La, Gd) materials irrespective of crystal structure (tetragonal, hexagonal and monoclinic phases) [18,19]. According to the relationship of the group theory and Eu 3+ emission spectrum, if the Eu 3+ ions occupy the C i , C 2h or D 2h symmetry site, the emission of 5 D 0 → 7 F 1 will present three sharp lines; If the Eu 3+ ions occupy the C 4h , D 4h , D 3d , S 6 , C 6h or D 6h symmetry site, the emission of 5 D 0 → 7 F 1 will present two sharp lines; If the Eu 3+ ions occupy the T h or O h symmetry site, the emission of 5 D 0 → 7 F 1 will present one sharp line.…”

“…The symmetry around the Eu 3+ ions in the AlPO 4 environment also can be understood using a ratio of intensities (A 21 ) of electric dipole transition to magnetic dipole transition (called asymmetric ratio A 21 ) which is defined as [18]:…”

Ionic Liquid‐based Synthesis—A Low‐Temperature Route to Nanophosphates

“…For all as-prepared nanophosphate materials LnPO 4 :Eu(5 %), the decay times under the 270 nm excitation monitored at the most-intense transition were determined ( 3+ doped YPO 4 depending on the synthesis method (solid state, co-precipation, or sol-gel) and grain size, decay times of 2.7-3.4 ms were obtained. [20] For the nanoscale GdPO 4 :Eu varying decay times of 1-7 ms have been reported, [21] while for LaPO 4 nanowires and nanorods values between 1.70-2.40 ms [22] and 3.96-1.98 ms [23] , respectively, have been obtained (as a function of active ion concentration). The calculated quantum yields were 34 % for YPO 4 :Eu, 47 % for LaPO 4 :Eu, and 57 % for GdPO 4 :Eu.…”

Observation of intermediate bands in Eu3+ doped YPO4 host: Li+ ion effect and blue to pink light emitter

“…When we see site symmetry of Eu 3+ in YPO 4 , it should be D 2d which has asymmetric environment with two different Eu-O bond lengths. 22,23,44 In such view, the electric dipole transition should be more than the magnetic dipole transition (i. e., A 21 ≥ 1.0). Variation in intensities of these two dipole transitions at different excitation wavelengths was not discussed in the previous studies to the best of authors' knowledge.…”