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The series of Mn2+ single doped fluoride-based K3Ca2(SO4)3F phosphor was prepared by the conventional high temperature solid-state reaction method. The formation of phase purity and morphology was ...

Near-UV (NUV)-excitable blue-light-emitting Eu2+ ions-doped Ca-chabazite Ca1.9Al3.8Si8.2O24 phosphor was synthesized by facile urea-assisted combustion synthesis method. Prepared materials were characterized by X-ray diffraction (XRD) study, scanning Electron Microscopy (SEM), and photoluminescence (PL) spectroscopy. The Eu2+-doped Ca1.9Al3.8Si8.2O24 calcium aluminosilicate phosphor exhibited intense and broad emission in the blue region. CIE chromaticity coordinates were plotted and obtained values were compared with standard NTSC coordinates. Electron vibration interaction (EVI) parameters such as Huang Rhy’s factor (S) and effective phonon energy (ħω) were calculated to determine the strength of electron–phonon coupling. The prepared mineral-based blue-emitting Near-UV-excitable phosphor may prove to be a potential candidate as a blue component for the white light emitting diode (wLED).

A trivalent Dy3+ -activated K3 Ca2 (SO4 )3 F fluoride-based phosphor was synthesized using a solid-state reaction method and characterized for its thermoluminescence (TL) application. The crystal structure and surface morphology of the as-synthesized material was analyzed using X-ray diffraction and scanning electron microscopy. A series of the K3 Ca2 (SO4 )3 F:Dy3+ phosphor was irradiated using γ-rays from a 60 Co source and TL glow curves were recorded using a Nucleonix 1009I TL reader. The glow curve of the prepared phosphor showed a prominent single peak at 278°C. TL characteristics were maximum intensity at 1 mol% of Dy3+ ion with a single TL glow peak. The TL glow curve revealed linearity with increase in exposure dose range from 0.1 kGy to 3.0 kGy. Theoretical analysis of the TL glow curve of the γ-ray-irradiated sample was carried out using a computerized glow curve deconvolution method and trapping parameters such as activation energy and frequency factor were calculated using the initial rise method and Ilich's method. The synthesized Dy3+ -doped K3 Ca2 (SO4 )3 phosphor revealed excellent TL properties and was found to be a potential candidate for dosimetric applications.

We report here, the Ca9La(PO4)5(SiO4)F2:1 mol%Eu3+ phosphor via doping of chloride, molybdate, vanadate, sulfate, and tungstate ions that were synthesized by high-temperature solid-state reaction method. The phase formation was confirmed by X-ray diffraction (XRD) measurements. Morphological studies were performed using scanning electron microscopy. Photoluminescence and thermoluminescence properties of the synthesized phosphors were systematically studied. The PL excitation spectra of host material show peaks at 395 nm and 466 nm corresponding to 7F0 → 5L6 and 7F0 → 5D2 transitions of Eu3+, respectively. Further photoluminescence properties also studied after doping of molybdate, vanadate, sulfate, and tungstate ions in host material. When excited at 395 nm and 466 nm, PL emission spectra show emission band at around 595 nm and 616 nm, which attributes to 5D0 → 7F1 and 5D0 → 7F2 transitions, respectively. Further TL glow curves of all the synthesized phosphors were studied when exposed to γ-rays.

The fluoroapatite Ca9La(PO4)5(SiO4)FCl:1 mol% Eu3+ phosphor was synthesized by conventional solid state reaction. In the present work keeping concentration of F1Cl1 constant and (PO4)3− of the material was replace by (MoO4)3−. The phase purity and surface morphology was evaluated through X-ray diffraction and scanning electron microscope technique. The emission and excitation spectra were investigated using photoluminescence spectroscopy. The excitation and emission spectra indicate that prepared phosphor effectively excited by 278 nm, exhibits emission peak at 595 nm and 616 nm corresponds to yellow and red colour attributes to 5D0→7F1 and 5D0→7F2 transitions respectively. The above result reveals prepared phosphor is excellent red phosphor in white light emitting diode application.

The phosphor converted w-LEDs gaincrucial attention in solid state lighting (SSL) for generation of illumination owing to their numerous meritorious advantages such as superior life time, excellent efficiency, compactness, reliability and power saving consumption as well as environmental friendly. The quality of w-LEDs in lighting and display is influence by host phosphorand the choice of activator. So greatlyattemptwere dedicated to developed inventiveuni-nucleiluminescent phosphor materials compose of chromatic stability, optimum CRI and low correlated color temperature. This review elaborate theintroduction ofEu3+rare earth activated red emitting phosphor assigned to 5D0→7FJ (J= 1,2,3,4) energy levelsand its fundamental merit for w-LEDs. This article represent the analyseofcombination of different types of Eu3+ activated luminescent materials by traditional and novel methods and its impact on photoluminescence for SSL.

Inorganic phosphors based on RbBaScSi3O9 (RBS), a chemically and thermally stable host doped with Ce3+; Eu2+ and codoped with Ce3+/Eu2+ and Eu2+/Dy3+ ions have been developed by an ‘amorphous based metal complex method’ using a water soluble silicon compound. The phase purity of the phosphors has been verified by X-ray powder diffraction technique. RBS:Ce3+(4%) phosphor exhibits a broad excitation spectrum in UV spectral region and a broad emission band centred at ∼439 nm with a full-width at half-maximum of ∼85 nm under the UV excitation. RBS:Eu2+ phosphor showed intense cyan-green emission which has been found to increase by three times in Ce3+/Eu2+ co-doped phosphors owing to the energy transfer from Ce3+ to Eu2+ in RBS:Ce3+, Eu2+ phosphor. Moreover, by co-doping RBS with Eu2+ and Dy3+ ions, the cyan-green emission of Eu2+ has been found to enhance considerably; about 6.9 times higher as compared to the emission intensity of RBS:Eu2+ phosphor. This increase is attributed to the generation of large number of traps similar to the pre-existing traps as a result of the incorporation of Dy3+ ion in RBS host and the enhancement in PL has also been substantiated from the enhanced thermoluminescence intensity of RBS:Eu2+, Dy3+ phosphor with respect to RBS:Eu2+ phosphor. Although the afterglow duration of RBS:Eu2+ and RBS:Eu2+, Dy3+ phosphors are in the similar range, but the afterglow intensity of half maxima was found to be 1.63 times higher in RBS:Eu2+,Dy3+ as compared to RBS:Eu2+ which owes to the enhanced photoluminescence intensity of the former as compared to the latter. The short but intense afterglow of RBS:Eu2+,Dy3+ phosphor indicates its potential for making glow bullet for defense application. Furthermore, when compared with, the photoluminescence (PL) emission intensity of near UV- excitable RBS:Eu2+, Dy3+ phosphor has been found to be ∼2 times higher than the green emitting commercial phosphor from Intermix reflecting the potential of this phosphor for the fabrication of phosphor-converted LED.

La1-xPO4:xTb (x = 0.01 ≤ x ≤ 0.11) phosphors were synthesized using conventional co-precipitation method. The powder X-ray diffraction confirmed the pure phase formation of LaPO4 host material. Upon ultra-violet (UV) excitation and vacuum ultra-violet (VUV), the phosphor showed a dominant green emission band centered at 544 and 545 nm, respectively due to the 5D4→7F5 transition of Tb3+. The concentration quenching phenomena occurred when Tb3+ concentration was beyond 0.09 mol and this quenching mechanism could be explained by the dipole-dipole interaction. The optimal concentration was found to be 0.09 mol of Tb3+ ion. The CIE chromaticity coordinates of the optimized (La0.91PO4:0.09Tb) phosphor was determined to be (0.265, 0.567). All the analyzed results confirms that the La1-xPO4:xTb (x = 0.01 ≤ x ≤ 0.11) phosphors can find possible applications as promising green-emitting phosphor in near UV and VUV used in plasma display panels.