Synthesis and characterization of BaAl2O4:Eu2+ co-doped with different rare earth ions

Sivaramaiah²,

et al. 2019

Bull Mater Sci

A BaAl 2 O 4 :Gd 3+ phosphor was successfully prepared using a combustion technique. An X-ray diffraction pattern was used to characterize the resultant phosphor, and the photoluminescence (PL) of the prepared BaAl 2 O 4 :Gd 3+ was studied. Under a 273-nm excitation, the main emission peak of the phosphor is located at 314 nm, and this is attributed to the 6 P 7/2 → 8 S 7/2 transition of Gd 3+. Electron paramagnetic resonance (EPR) spectrum appears to be U-shaped, and lines are evident at g eff ∼ 2.14, 4.56 and 6.75. The PL and EPR analyses indicate the presence of Gd as Gd 3+ in this sample.

Section: Introductionmentioning

confidence: 99%

Ultraviolet B emission from a $$\hbox {Gd}^{3+}$$ Gd 3 + -doped $$\hbox {BaAl}_{2}\hbox {O}_{4}$$

Sivaramaiah²,

et al. 2019

Bull Mater Sci

“…7 For existing two types of Ce 3+ ions in topic phosphors, the decay curves should be well fitted with a typical two exponential function53:…”

Section: Resultsmentioning

confidence: 99%

Blue-green tunable color of Ce3+/Tb3+ coactivated NaBa3La3Si6O20 phosphor via energy transfer

Zeng

Xia

2016

Sci Rep

A series of color tunable phosphors NaBa3La3Si6O20:Ce3+, Tb3+ were synthesized via the high-temperature solid-state method. NaBa3La3Si6O20 crystallizes in noncentrosymmetric space group Ama2 with the cell parameters of a = 14.9226(4) Å, b = 24.5215(5) Å and c = 5.6241(2) Å by the Rietveld refinement method. The Ce3+ ions doped NaBa3La3Si6O20 phosphors have a strong absorption band from 260 to 360 nm and show near ultraviolet emission light centered at 378 nm. The Ce3+ and Tb3+ ions coactivated phosphors exhibit color tunable emission light from deep blue to green by adjusting the concentration of the Tb3+ ions. An energy transfer of Ce3+ → Tb3+ investigated by the photoluminescence properties and lifetime decay, is demonstrated to be dipole–quadrupole interaction. These results indicate the NaBa3La3Si6O20:Ce3+, Tb3+ phosphors can be considered as potential candidates for blue-green components for white light emitting diodes.

“…35 The raw materials used for this method are the nitrates of strontium, aluminum, europium, and dysprosium and urea as a fuel. 36 In recent years, different synthesis techniques, such as the chemical precipitation, 37 the solvothermal method, 38 microwave processing, hydrothermal processing, 39 hydrothermal co-precipitation, 40 laser synthesis, 41 and microemulsion route 42 have been developed for the preparation of phosphors with different luminescence characteristics. This synthesis process makes use of the heat energy liberated from the reaction between the metal nitrates and urea at 500°C.…”

Section: The Combustion Methodsmentioning

confidence: 99%

Developments in Eu⁺²‐Doped Strontium Aluminate and Polymer/Strontium Aluminate Composite

et al. 2014

The discovery of rare earth based phosphors in 1960s started a new era of luminescence. In comparison with sulfide-based phosphors, strontium aluminates received worldwide acceptance because of their chemical stability and good luminescent properties. The SrAl x O y :Eu 2+ ,Dy 3+ phosphors excited by UV or visible light emit phosphorescence in the blue-green region after the excitation source has been removed, and the phosphorescence last for more than 15 h. The major disadvantage of SrAl x O y :Eu 2+ ,Dy 3+ phosphors is that they are prone to hydrolysis and their luminescent properties gradually deteriorate. The dispersion of these phosphors in a waterproof polymer matrix is an alternative method reported for retaining their luminescent properties. The review extensively deals with strontium aluminate based luminescent materials, the mechanism of luminescence, their synthesis techniques, and different mixing procedures to prepare polymer/strontium aluminate composites. Different methods to improve the dispersion of the strontium aluminate in the polymer matrix are also outlined. C