Photoluminescence, trap states and thermoluminescence decay process study of Ca2MgSi2O7: Eu2+, Dy3+ phosphor (original) (raw)
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Luminescence : the journal of biological and chemical luminescence, 2015
A europium (Eu)-doped di-calcium magnesium di-silicate phosphor, Ca2 MgSi2 O7 :Eu(2+) , was prepared using a solid-state reaction method. The phase structure, particle size, surface morphology, elemental analysis, different stretching mode and luminescence properties were analyzed by X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM) with energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared (FTIR) spectroscopy, photoluminescence (PL) and mechanoluminescence (ML). The phase structure of Ca2 MgSi2 O7 :Eu(2+) was an akermanite-type structure, which belongs to the tetragonal crystallography with space group P4̅21 m; this structure is a member of the melilite group and forms a layered compound. The surface of the prepared phosphor was not found to be uniform and particle distribution was in the nanometer range. EDX and FTIR confirm the components of Eu(2+) -doped Ca2 MgSi2 O7 phosphor. Under UV excitation...
Research on Chemical Intermediates, 2014
Sr 2 MgSi 2 O 7 :Eu 2? , Dy 3? and Ca 2 MgSi 2 O 7 :Eu 2? , Dy 3? phosphors were synthesized by the high-temperature solid-state reaction method. The phase structure of the prepared phosphors was of akermanite type, which belongs to the tetragonal crystallography. The EDX and FTIR spectra confirm the presence of elements in prepared phosphors. Sr 2 MgSi 2 O 7 :Eu 2? , Dy 3? and Ca 2 MgSi 2 O 7 :Eu 2? , Dy 3? phosphors would emit blue and green light; the main emission peaks that appeared at 465 and 535 nm belong to the broad emission band ascribed to the 4f 6 5d 1 ? 4f 7 transition. Decay graph indicates that both the phosphors have fast decay and slow decay. Investigation into afterglow property showed that the Sr 2-MgSi 2 O 7 :Eu 2? , Dy 3? phosphor held better afterglow property than Ca 2 MgSi 2 O 7 :-Eu 2? , Dy 3? phosphors. ML measurements showed a linear increase in the ML intensity with the impact velocity of the moving piston.
Synthesis and luminescence properties of Ca3Ga2Si3O12:RE3+ (RE = Eu/Tb) powder phosphors
Luminescence, 2011
Rare earth ions (Eu 3+ or Tb 3+)-activated Ca 3 Ga 2 Si 3 O 12 (CaGaSi) phosphors were synthesized by using a sol-gel method. Photoluminescence spectra of Eu 3+ : CaGaSi phosphors exhibited five emission bands at 578, 592, 612, 652 and 701 nm, which were assigned to the transitions (5 D 0 → 7 F 0 , 7 F 1, 7 F 2 , 7 F 3 and 7 F 4), respectively, with an excitation wavelength of λ exci = 392 nm. Among these, the transition 5 D 0 → 7 F 2 (612 nm) displayed bright red emission. In the case of Tb 3+ : CaGaSi phosphors, four emission bands were observed at 488 (5 D 4 → 7 F 6), 543 (5 D 4 → 7 F 5), 584 (5 D 4 → 7 F 4) and 614 nm (5 D 4 → 7 F 3) from the measurement of PL spectra with λ exci = 376 nm. Among these, the transition 5 D 4 → 7 F 5 at 543 nm displayed bright green emission. The structure and morphology of the phosphors were studied from the measurements of X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDAX) results.
Synthesis Photoluminescence study of Ca2MgSi 2 O7 : Ce
This paper reports the photoluminescence properties of Ca2MgSi 2 O 7 phosphor with different concentrations of trivalent cerium Ce, dyposium Dy and divalent Eu as dopant. The phosphor is synthesized using the solid state reaction. Photoluminescence studies is done on the prepared phosphor. For crystal structure and surface morphology SEM micrographs of Ca2MgSi 2 O 7 : Ce, Dy , Eu phosphor were also studied. From SEM confirms the formation of micro phosphor in the range around 100 μm-500μm
Journal of Radiation Research and Applied Sciences, 2015
Europium doped di-strontium magnesium di-silicate phosphor namely (Sr 2 MgSi 2 O 7 :Eu 3þ) was prepared by the traditional high temperature solid state reaction method. The phase structure of sintered phosphor was akermanite type structure which belongs to the tetragonal crystallography with space group P42 1 m, this structure is a member of the melilite group and forms a layered compound. The EDX and FTIR spectra confirm the present elements in Sr 2 MgSi 2 O 7 :Eu 3þ phosphor. Photoluminescence measurements showed that the phosphor exhibited strong emission peak with good intensity, corresponding to 5 D 0 / 7 F 2 (613 nm) red emission and weak 5 D 0 / 7 F 1 (590 nm) orange emission. The excitation spectra monitored at 613 nm show broad band from 220 to 300 nm ascribed to OeEu charge-transfer band (CTB) centered at about 269 nm, and the other peaks in the range of 300e400 nm originated from fef transitions of Eu 3+ ions. The strongest band at 395 nm can be assigned to 7 F 0 / 5 L 6 transition of Eu 3þ ions due to the typical fef transitions within Eu 3þ of 4f 6 configuration.
Luminescence Properties of Sr2MgSi2O7:Eu2+, Ce3+ Phosphor by Solid State Reaction Method
Physics Procedia, 2015
The Sr 2 MgSi 2 O 7 :Eu 2+ , Ce 3+ phosphor was prepared by solid state reaction method, boric acid (H 3 BO 3) was added as flux. The phase structure of Sr 2 MgSi 2 O 7 :Eu 2+ , Ce 3+ phosphor was akermanite type structure which belongs to the tetragonal crystallography with space group P4̅ 2 1 m, this structure is a member of the melilite group and forms layered compound. EDX and FTIR spectra confirm the present elements in Sr 2 MgSi 2 O 7 :Eu 2+ , Ce 3+ phosphor. Three peaks in excitation spectra were found at 253, 293, 325nm and corresponding emission peak was recorded at 465nm, belonging to the broad emission ascribed to the 4f 6 5d 1 →4f 7 transition of Eu 2+. The ML intensity of prepared phosphor was increasing linearly with increases of mechanical load.
Studies on thermoluminescence properties of alkaline earth silicate phosphors
Journal of Alloys and Compounds, 2018
In this paper we report the Thermoluminescence behaviour of Sr 3 MgSi 2 O 8 phosphor doped with Dy 3+ synthesized by solid state reaction process. The prepared phosphors were characterized by the X-ray powder diffraction (XRD) method. The Thermoluminescence (TL) behaviour is studied for the 254 nm ultra violet (UV) exposure. The TL glow curve has dual peaks at 70 0 C and 213 0 C. All the TL parameters such as UV exposure time, dopant concentration, heating rate etc were optimized. The maximum TL intensity was found for 30 minutes UV exposure, 2.0 mol% Dy 3+ Concentration and at 4 0 C s -1 heating rate. The Kinetic parameters namely, activation energy (E), order of kinetics (b) and frequency factor (s) of Sr 3 MgSi 2 O 8 :Dy 3+ sample have been determined using Chen's method for the deconvoluted glow curve.
Photoluminescence and thermoluminescence studies of Mg2SiO4:Eu3+ nano phosphor
Journal of Alloys and Compounds, 2011
Nanoparticles of Eu 3+ doped Mg 2 SiO 4 are prepared using low temperature solution combustion technique with metal nitrate as precursor and urea as fuel. The synthesized samples are calcined at 800 • C for 3 h. The Powder X-ray diffraction (PXRD) patterns of the sample reveled orthorhombic structure with ␣-phase. The crystallite size using Scherer's formula is found to be in the range 50-60 nm. The effect of Eu 3+ on the luminescence characteristics of Mg 2 SiO 4 is studied and the results are presented here. These phosphors exhibit bright red color upon excitation by 256 nm light and showed the characteristic emission of the Eu 3+ ions. The electronic transition corresponding to 5 D 0 → 7 F 2 of Eu 3+ ions (612 nm) is stronger than the magnetic dipole transition corresponding to 5 D 0 → 7 F 1 of Eu 3+ ions (590 nm). Thermoluminescence (TL) characteristics of ␥-rayed Mg 2 SiO 4 :Eu 3+ phosphors are studied. Two prominent and well-resolved TL glows with peaks at 202 • C and 345 • C besides a shoulder with peak at ∼240 • C are observed. The trapping parameters-activation energy (E), order of kinetics (b) and frequency factor (s) are calculated using glow curve shape method and the results obtained are discussed.
Luminescent properties of blue-emitting long afterglow phosphors Sr2−xCax MgSi2O7:Eu2+, Dy3+ (, 1)
Journal of Luminescence, 2006
The luminescence of two newly developed blue-emitting long afterglow phosphors, Sr 2Àx Ca x MgSi 2 O 7 :Eu 2+ , Dy 3+ (x ¼ 0, 1), has been studied. The emission under VUV-UV excitation from a synchrotron radiation source, along with the long afterglow spectra have been measured at different temperatures ranging from 7 to 300 K. While the emission spectra under 170 nm excitation exhibit both the 5d-4f transitions of Eu 2+ and 4f-4f transitions of Dy 3+ , only the blue band corresponding to the 5d-4f transitions of Eu 2+ is observed in the long afterglow spectra. Emission of Sr 2 MgSi 2 O 7 :Eu 2+ , Dy 3+ excited by an intense VUV laser source (157.6 nm) is also reported. The rich line structures in the laser-excited emission spectra partly result from 4f-4f transitions of Eu 3+ , indicating an efficient photon-induced process, which promotes Eu 2+ to Eu 3+. The thermoluminescence covering the temperature range from 50 to 450 K for both samples has been measured as well and the depth of the traps responsible for the long afterglow emission was estimated. The mechanism of the persistent luminescence and the origin of the traps are discussed in the light of these results.