Different Concentrations Of Dy3 Research Articles

Synthesis and properties research of Dy3+-Eu3+ co-doped BBiBaZ luminescent glass for white LED applications

A series of BBiBaZ luminescent glasses with different concentrations of Dy3+ doping and Dy3+-Eu3+ co-doping was planned by the high-temperature melt method. Their structure, chemical stability, glowing properties, energy transfer, and temperature-dependent emission spectra were also investigated. Under various monitor wavelengths, the visible emitted spectrum of the Dy3+-Eu3+ co-doping luminescent glass was obtained. The presence of Dy3+→Eu3+ energy transfer in the glass was demonstrated by emission spectra and fluorescence decay curve analyses. At the excitation of 384 nm, better white color emitting was noticed in BBiBaZ glass doped with Dy2O3 doping concentration of 0.75 mol% and doped with 0.4 mol% Eu2O3 with a CIE of (0.3306, 0.342), and the glass has an ΔE of 0.221 eV, which suggests that the synthesis glass has the prospective to be applied in white light solid-state lighting. In addition, the Dy3+-Eu3+ co-doped BBiBaZ glass could achieve tunable emission moving from cooling white to heating white to an orange-red light under 390 nm excitation. The adjustable range of the glass’s CCT values has been expanded, allowing for arbitrary tuning between approximately 2004–6380 K, which adapts to different application fields.

Effect of dopant concentration on photoluminescence properties of Dy3+ doped Gd2O3 nanophosphors under different excitation wavelengths

In this work, the role of dopant Dy3+ concentration and excitation wavelength on luminescence properties of Dy3+ doped Gd2O3 nanophosphors prepared by chemical precipitation method were studied. The phosphors were characterized by X-ray diffraction (XRD), Energy dispersive analysis of X-ray (EDAX) and photoluminescence spectroscopy. The crystallite sizes of the phosphors were found to be in the range of 11–17 nm. The profile of the emission spectra for the phosphors was independent of dopant concentration as well as excitation wavelengths. The photoluminescence emission peaks were observed at 486 nm and 574 nm corresponding to 4F9/2-6H15/2 and 4F9/2-6H13/2 transitions respectively. The optimum concentration of Dy3+ for maximum emission intensity was found to be 2 at.% of Dy3+ which was independent of excitation wavelength. The emission intensity of all prepared phosphors under 234 nm excitation wavelength was found to be stronger than that of 278 nm. This showed the energy transfer due to host absorption was more efficient. The color emission of different concentration of Dy3+ doped Gd2O3 nanophosphors under different excitation wavelengths were studied from calculated CIE coordinates and was found to be shifted towards the blue region with the increase of dopant concentration.

Investigation on luminescence properties and XANES of dysprosium ion doped borophosphate glasses

In this research, melt quenching was used to prepare Dy3+ ion doped alkaline borophosphate glasses. According to the XANES measurement, Dy ions in glass show +3 oxidation state, identical to the standard Dy2O3 powder. Glasses were measured for density (ρ), molar volume (Vm), and refractive index (n). The absorption peaks, which are assigned to transitions from the ground state 6H15/2 to higher energy levels of Dy3+ ion in glass matrix. Four prominent emission bands were observed in luminescence spectra, which correspond to the 4F9/2→6HJ (J = 15/2, 13/2, 11/2, 9/2) transitions. The Judd-Ofelt (J-O) intensity parameters follow the trend as Ω2>Ω6>Ω4 of the PBLAGdDy1.0. For the stimulated emission cross-section and branching ratio (>0.5), 4F9/2 → 6H13/2 transition was found to be higher than other transitions. Because the decay curves of glasses with different concentrations of Dy3+ ion were found to be non-exponential, these glasses were calculated using the Inokuti-Hirayama (I-H) model. The obtained photoluminescence and decay times spectra primarily showed energy transfer effects from Gd3+ to Dy3+ ions and the calculated values of energy transfer efficiency (η) found that the values increased, which confirms energy transfer from Gd3+ to Dy3+ ions. From this study, the current glasses could be useful in the applications of solid-state lasers, LEDs, and scintillation materials.

Enhanced the luminescent performance of CsPbI3 quantum dot-embedded borosilicate glass by controlling crystallization using Dy3+ ions as nucleating agent for remote color-tunable LEDs

Different concentrations of Dy3+ and perovskite quantum dots (PQDs) were simultaneously embedded in the B-Si-Zn glasses by melt-quenching and heat-treatment subsequently. A battery of experimental results including TEM, distribution of different elements, and photoluminescence prove that partial Dy ions are successfully doped into CsPbI3 and played different roles depending on the doping concentration. When the Dy3+ concentration is circa 0.1mol%, Dy3+ as a nucleation agent reduces the energy required for the precipitation and growth of perovskite quantum dots, obtaining outstanding quantum efficiency of 31.82%. The excess Dy3+ supplement will prevent the mobility of PQDs elements. Based on the as-made glass sample, the remote fluorescent films have been successfully prepared. A kind of prototype lighting device was assembled, which demonstrated a high color rendering index of 96.5 under the current of 20 mA. Interestingly, by adjusting the concentration of Dy3+, color regulation can be achieved from orange-red light to yellow-white light.

Structure and luminescence properties of Dy3+ doped quaternary tungstate Li3Ba2Gd3(WO4)8 for application in wLEDs.

Quaternary tungstates with the composition Li3Ba2Gd3(WO4)8 doped with different concentrations of Dy3+ (from 0.5 to 10 at%) were prepared by the solid-state reaction method at 900 °C. Their structural, spectroscopic and optical properties were studied systematically in this work. X-ray diffraction analysis confirmed the crystallization of Li3Ba2Gd3(WO4)8 to have a monoclinic structure (sp. gr. C2/c); the lattice constants for 1 at% doping concentration of Dy3+ are a = 5.2126(2) Å, b = 12.7382(1) Å, c = 19.1884(3) Å, Vcalc = 1273,40(4) Å3 and β = a × c = 91.890(9)°. The first principles calculations for the undoped crystal revealed a direct bandgap of 2.45 eV, which is very close to the experimental one. The identified broad, and strong excitation peak at 450 nm indicates that Li3Ba2Gd3(WO4)8:Dy3+ phosphors are suitable to be pumped by a blue laser diode (LD). Under excitation at 445 nm, the phosphor showed a stronger luminescence peak at 575 nm which corresponds to the Dy3+:4F9/2 → 6H13/2 transition, and three weaker emissions peaks at 477, 661, and 750 nm. Meanwhile, the effect of different Dy3+ contents on the luminescence properties was investigated. The optimum concentration to minimize the quenching effect was 4 at% and the critical distance is 31.209 Å. The phosphor emitted strong greenish-yellow light situated at (0.425, 0.472) in CIE coordinates with a color temperature of 3652 K. All the measured luminescence lifetime curves exhibited a single-exponential nature. Excellent thermal stability was found for this tungstate phosphor (the activation energy is 0.352 ± 0.01 eV). The measured absolute photoluminescence quantum yield was around 10.5%. The results presented in this work show that Li3Ba2Gd3(WO4)8:Dy3+ phosphors with strong yellow emission are promising candidates for white-light emitting LED (wLED) applications.

Investigation of Thermoluminescence (TL) and Optically Stimulated Luminescence (OSL) Properties of Dy3+ Doped CaB4O7 Nanoparticles.

CaB4O7 nanoparticles doped with different concentrations of Dy3+ were prepared by using solution combustion method. The recorded Thermoluminescence (TL) and Optically stimulated luminescence (OSL) of CaB4O7:Dy samples for different concentrations of Dy3+ irradiated with 6Gy of X-Ray shows concentration quenching effect above 0.05 at.wt% of Dy3+ concentrations. The TL and OSL kinetic parameters of glow curves were evaluated using "tgcd" and conventional fitting methods. The TL glow curve of the CTB:(0.05%)Dy have five individual glow peaks with maximum peak temperatures at 410, 470, 525, 563 and 593K. TL Dose response of the X-Ray irradiated CTB:(0.05%)Dy is also found to be linear in the range of 1Gy to 50Gy. The OSL glow curves of the CTB:Dy nanoparticles follow non-first order kinetics and can be fitted with the sum of three first order decay curves. Fading characteristics of the TL and OSL signals are studied for 40days and found to be very stable.

Preparation of Dy3+/Tm3+ Co-doped Phosphate Glasses by Melt Method and its Luminescence Properties

In this paper, P2O5 matrix materials were used to prepare Dy3+/Tm3+ phosphate glasses with different concentrations by high temperature melt method. The emission spectrum of Dy3+/Tm3+co-doped glass samples were measured under 350nm excitation. High-efficiency green and blue down-conversion emissions were already observed. Based on the intensity of the emission peaks of samples doped with different concentrations of Dy3+/Tm3+, It can be assumed that an energy transfer process is occurring between Dy3+/Tm3+, i.e. the energy transfer process between the two kinds of ions is Dy3+ to Tm3+ and Tm3+to Dy3+, respectively. Finally, the energy transfer between Dy3+/Tm3+ was further illustrated by testing the fluorescence decay lifetime of the samples. It was found that the increased probability of cross relaxation of ions in glasses doped with 0.8mol% Dy3+/0.2mol% Tm3+ caused the fluorescence quenching of Dy3+ ions, and a fluorescence color shift from blue to white was observed in the range of 0.2-0.7mol% Dy3+. CIE coordinates of the 0.2mol% Tm3+/0.7mol% Dy3+ co-doped phosphate glasses sample are (0.33, 0.32), which is extremely approximate to the standards of equivalent energy white light for illumination (0.33,0.33). The results indicate that Dy3+/Tm3+ has a significant contribution in the down-conversion mechanism.

Color-tunable luminescence, energy transfer behavior and I–V characteristics of Dy3+,Eu3+ co-doped La(PO4) phosphors for WLEDs and solar applications

We synthesize different concentrations of Dy3+,Eu3+ doped and co-doped La(PO4) phosphors via the solid-state synthesis and test their photoluminescence and I–V characteristics for WLEDs and solar panels.

Synthesis and optical properties of novel apatite-type NaCa3Bi(PO4)3F:Dy3+ yellow-emitting fluorophosphate phosphors for white LEDs

In this study, novel yellow-emitting fluorophosphate NaCa3Bi(PO4)3F phosphors doped with different concentrations of Dy3+ ions were first obtained via high-temperature solid-state reaction. The crystal structure, phase purity, particle morphology, photoluminescence (PL) properties, thermal stability, and luminescence decay curves of the resulting phosphors were then characterized in detail. Under the excitation of 349 nm, the three dominant peaks of the NaCa3Bi(PO4)3F:Dy3+ are centered at 480 nm (4F9/2-6H15/2), 577 nm (4F9/2-6H13/2), and 662 nm (4F9/2-6H11/2). The optimal doping concentration of Dy3+ ions in the NaCa3Bi(PO4)3F:xDy3+ phosphors is x = 5 mol%. The phosphors show excellent thermal stability with high activation energy (Ea = 0.32 eV). Eventually, the synthesized white light-emitting diode (w-LED) demonstrates the Commission International de L'Eclairage (CIE) chromaticity coordinates of (0.341, 0.334), a good correlated color temperature (CCT) of 5083 K, and a high color rendering index (Ra) of 92. Revealing its potential as yellow-emitting phosphors, the feasibility of the fabricated apatite-type NaCa3Bi(PO4)3F:Dy3+ fluorophosphate phosphors was confirmed for w-LEDs.

Cool white light emission from Dy3+-doped SiO2 – Bi2O3 – Ga2O3 – B2O3 -GeO2- TeO2 glasses: Structural and spectroscopic properties

The authors aim to study multi former oxide glasses doped with different concentrations of Dy3+ (0.00, 0.5, 1.0, 1.5, and 2 mol%) for white light-emitting application. All samples characterized by XRD, FTIR, and optical properties (absorption, excitation, and emission). The optical band gap calculated by a differential method. FTIR spectra confirm the network composed of GaO4, GeO4, TeO4, and BO4 tetrahedra, BO3 triangles, B-O-B linkages, and SiO4 tetrahedra with one NBO. In addition to the TeO3, BiO3, TeO6, and BiO6 vibration groups.Oscillator strengths and Judd–Ofelt parameters (Ω2, Ω4, Ω6) calculated and found that the glass samples had a variable trend from Ω2 > Ω4 > Ω6 to Ω2 > Ω6 > Ω4, at a Dy2O3 content >1 mol%. Furthermore, radiative emission transition probability (AR), branching ratio (βR), and radiative lifetime (τR) estimated for Dy3+ ion in various excited states using J–O parameters. Upon 454 nm excitation, 4F9/2 → 6H15/2 [483 nm (blue)], 4F9/2 → 6H13/2 [575 nm (yellow)], and 4F9/2 → 6H11/2 [680 nm (red)] emission. Among them, it noticed that the transition 4F9/2 → 6H13/2 shows the highest intensity.The CIE chromaticity coordinates, correlated color temperature (CCT), and color purity (CP) indicate a generally neutral white light emission from all samples, which meant their suitability for optical applications. Determination of the white light coordinated from the CIE program, which verifies the values of samples are close to the pure white light. And sample containing 2 mol% Dy3+ close to the standard CIE D65 glow.

Physical, structural and optical characterization of Dy3+ doped ZnF2-WO2-B2O3-TeO2 glasses for opto-communication applications

Abstract A series of ZnF2-WO2-B2O3-TeO2 (ZWFBT) glasses doped with different concentration of Dy3+ ions were prepared by using the melt quench method. The non-crystalline behavior of as-quenched ZWFBTDy glasses was approved by XRD spectra. The presence of different functional groups were identified by monitoring FT-IR spectra of ZWFBTDy glasses. The Differential Scanning Calorimetry (DSC) was used to estimate glass transition temperature (Tg) and thermal stability (ΔT) of an un-doped glass along with doped glasses. Physical parameters were estimated for Dy3+ doped ZWFBT glasses by using the formula available in the literature. The energy band gaps of as-quenched ZWFBTDy glasses were estimated by using three different theoretical models such as Mott and Davis relation, Hydrogenic Excitonic Model (HEM), and Urbach analysis. The optical absorption spectra were used to estimate the bonding parameters (δ) for elucidating the kind of bonding amide Dy3+ ions and its nearby ligands in the as-quenched glasses. The obtained experimental data from optical absorption spectra were compared with theoretical data calculated in the ambit of the Judd-Ofelt (J-O) theory. The J-O intensity parameters were estimated and a similar trend was observed ( Ω 2 > Ω 6 > Ω 4 ) for the as-prepared ZWFBTDy glasses. The results obtained using J-O intensity parameters are found consistent with the bonding parameters. The radiative parameters such as branching ratio, radiative transition, radiative lifetime, total radiative transition, absorption, and emission cross-sections were evaluated and discussed. The gain coefficient was evaluated for the NIR transitions of as-quenched ZWFBTDy glasses. The obtained results suggested that the as-prepared ZWFBTDy glasses were auspicious candidates for laser emission and optical communication applications.

Facile synthesis and thermoluminescence properties of nano bio-ceramic \u03b2-Ca2P2O7:Dy phosphor irradiated with 75\xa0meV C6+ ion beam

Dy3+ doped β-Ca2P2O7 phosphor has been synthesized using wet chemical method. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis confirmed the formation of β-Ca2P2O7:Dy nano-phosphors. However, photoluminescence (PL) study was carried out to confirm the presence of dopant ion in the host matrix of β-Ca2P2O7:Dy material. Thermoluminescence (TL) glow curves of β-Ca2P2O7 were recorded for different concentrations of Dy3+ after exposure to various fluences of C6+ ion beam (75 meV). TL sensitivity of β-Ca2P2O7:Dy3+ (0.1 mol%) phosphor was 3.79 times more than commercially available CaSO4:Dy3+. TRIM code based on the Monte Carlo simulation was used to calculate the absorbed doses, ion range and main energy loss. Glow curve de-convolution (GCD) method was used to determine the number of TL peaks and their trapping parameters. The wide linear response of β-Ca2P2O7 nanoparticles along with high stability of TL glow curve makes this nanomaterial a good candidate for C6+ ion beam dosimetry.

LUMINESCENCE BEHAVIOUR OF DY3+ ION DOPED MAGNESIUM SULFOBORATE PHOSPHOR FOR WHITE LIGHT EMITTING DIODES

Several studies showed the interesting properties of trivalent lanthanide ions when doped in various types of phosphor. Magnesium sulfoborate phosphor doped with different concentrations of Dy3+ were synthesized using solid-state reaction method at 850 °C for 4 hours. The samples were characterized by X-ray Diffraction (XRD). The excitation and luminescence properties of MgO-SO4-B2O3:Dy3+ were determined. The emission spectrum of Dy3+ ion doped MgO-SO4-B2O3 phosphor exhibit three bands at 480 nm, 573 nm and 660 nm with excitation of 386 nm due to 4F9/2 →6H15/2, 6H13/2 and 6H11/2 of Dy3+ transitions, respectively. The excitation spectrum of Dy3+ ion doped MgO-SO4-B2O3 phosphor display several bands at 347 nm, 362 nm, 386 nm, 426 nm, 449 nm and 469 nm with emission of 573 nm, which is in agreement with the ultraviolet LED (349.9–410 nm) and blue LED (450–470 nm). An intense in the emission peak at 573 nm in the yellow region was observed with the 0.5 Dy2O3. The luminescence properties of phosphor show that MgO-SO4-B2O3:Dy3+ phosphor could be potentially used as white LEDs.
 Dalhatu, A. S. | Department of Physics, Bauchi State University Nigeria, 65 Gadau, Bauchi, Nigeria

Luminescent characterization of CaMgSiO4:Dy3+phosphor for white light emitting diodes

Different concentration of Dy3+ doped calcium magnesium silicate (CMS) phosphors are synthesized via solid state synthesis (SSS) method at high temperature. The structural properties are analyzed by X-ray diffraction (XRD). The surface microstructures are confirmed by scanning electron microscopy (SEM)and energy dispersive X-ray (EDX) spectra. The vibrational properties of the synthesized phosphor are carried out using fourier transform infrared (FT-IR) spectra. The luminescence properties are explained in terms of photoluminescence (PL) and thermoluminescence (TL) characteristics. The PL spectra showed maximum emission intensity peaking at 484 and 578 nm, which are attributed to the 4F9/2 → 6H15/2 and4F9/2 → 6H13/2 transitions of Dy3+ ion respectively. The PL properties of the prepared phosphors are carried out at room temperature. The maximum PL intensity occurs at 0.5 mol% of doping concentrationof Dy3+ ions due to concentration quenching. The glow peak and TL parameters of the prepared phosphors are computed by means of peak shape method. The CIE color co-ordinates are originated (x= 0.3263, y= 0.3451) and correlated color temperature (CCT) are determined to be 5769 K. The results indicate that the prepared phosphor produces cool light in the white region.

Near-UV-excited Dy3+-doped calcium borophosphate (CBP) phosphors for white LED applications

Calcium borophosphate (CBP) phosphors doped with Dy3+ were synthesized by solid-state reaction method. These phosphors were characterized by photoluminescence spectra and decay curves in the visible region. These phosphors were excited at 350 nm, and emission spectra were studied. Decay curves were obtained for the transition, 4F9/2 → 6H13/2 of Dy3+, and lifetimes were measured for different concentrations of Dy3+ ions. CIE chromaticity coordinates were obtained for these Dy3+-doped CBP phosphors. Correlated color temperature was also calculated using the standard formula.

White Light Generation in Dy3+-Doped Sodium Lead Alumino Borosilicate Glasses for W-LED Applications

Excitation and emission spectra of sodium lead alumino borosilicate glass doped with different concentrations of Dy3+ have been reported. The concentration of Dy3+ were varied from 0.5 to 1.5 mol%. As a result of 385 nm excitation wavelength, the luminescence spectra showed three characteristic bands at 482 nm and 575 nm and 665 nm. These absorption bands were attributed to 4F9/2 → 6H15/2, 4F9/2 → 6H13/2 and 4F9/2 → 6H11/2 transitions respectively of Dy3+ ions. 4F9/2 → 6H15/2, 4F9/2 → 6H13/2 and 4F9/2 → 6H11/2 transitions respectively of Dy3+ ions. The yellow to blue intensity ratio increases (1.063 to 1.093) with increase in Dy3+ ion concentration. The decay rates exhibit single exponential for lower concentrations and turns into non exponential for higher concentrations. The non-exponential nature of the decay rates is well-fitted to the Inokuti-Hirayama model for S = 6, which indicates that the nature of the energy transfer between donor and acceptor ions is of dipole-dipole type. The lifetime for the 4F9/2 level of Dy3+ ion decreases (0.634 to 0.580 ms). The chromaticity coordinates have been calculated from the emission spectra and analyzed with Commission International de I’Eclairage diagram. The chromaticity coordinates visible in the white light region for all concentrations of Dy3+ ions in the present glasses. The correlated color temperature value varies from 5107 to 5362 K (closer to the day light value of 5500 K). These results indicate that Dy3+-doped sodium lead alumino borosilicate glasses can be development of white light emitting diodes and suitability for solid state lasers applications.

Thermoluminescence studies of Dy3+-doped calcium barium orthosilicate codoped with Li+ ion

Calcium barium orthosilicate (CaBaSiO4) phosphors having different concentrations of Dy3+ were prepared by solid-state reaction method, and phase structure of the sample was identified by X-ray diffraction (XRD) characterization. It is observed that the XRD pattern matched well with JCPDS file No. 48-0210. Thermoluminescence (TL) of the UV-irradiated (254 nm) samples was recorded using routine TL set-up Nucleonix TLD reader with constant heating rate 5 °C s−1. It is found that the sample containing 1 mol% of Dy3+ and exposed for 27 min gives optimum TL intensity at 130.14 °C and shows single TL glow peak. It order to examine the effect of charge compensator ion, Li+ ions are introduced and it is found the incorporation of charge compensator enhances the TL output. Samples having 1 mol% of Dy3+ and 6 mol% of Li+ exposed for 30 min to UV exposure show maximum intensity at 118 °C. It is also observed that temperature corresponding to TL peak varies with varying Li concentration (ranging from 105.76 to 123.88 °C). Samples having 1 mol% of Dy3+ and 6 mol% of Li+ exposed for 30 min to UV exposure were selected for further studies, such as activation energy, order of kinetics and frequency factor, and all these parameters were evaluated using peak shape method.

Structural characterization and effects of Dy concentration on luminescent properties of BaMgSiO4 phosphors

A series of barium magnesium silicate (BMS) - based phosphors doped with different concentrations of Dy3+ is synthesized by using conventional solid-state reaction technique (SSRT). The prepared phosphors are characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, fourier transform infrared (FTIR) spectra, photoluminescence (PL) and thermoluminescence (TL). X-ray diffraction analysis confirms the formation of BaMgSiO4 with hexagonal structure. The excitation spectrum signifies strong 4f–4f transition in the wavelength range from 300 nm to 400 nm. The emission spectra indicate the possibility of excitation of samples by UV light (384 nm) and show strong emission band centered at 577 nm. Analysis of the emission spectra with different Dy3+ concentrations leads to the conclusion that the optimum dopant concentration for prepared BMS phosphors is 0.01 of Dy3+. TL kinetic parameters of the prepared phosphors are estimated using peak shape method. The CIE chromatic coordinates indicate the suitability of BMS phosphor for solid state lighting.

Analysis of the physical, structural and optical characteristics of Dy3+-doped MgO–SrO–B2O3 glass systems

Numerous studies have shown the interesting properties of trivalent lanthanide ions when doped in different types of glasses. This article examines the physical, structural and optical properties of series of strontium magnesium borate glasses doped with dysprosium ion (Dy3+) and synthesized using the melt-quenching technique. Physical and optical properties such as density, molar volume, ion concentration, molar refractivity, polaron radius, reflection loss, inter-nuclear distance and molar polarizability for each concentration of the dopant were calculated and reported. The results revealed diverse variations in density with other measured parameters. The amorphous behaviour of the glass samples was confirmed by X-ray diffraction spectroscopy. FTIR spectra measurements revealed the presence of various functional groups and their associated assignments. Optical properties of the activated glass samples with different concentrations of Dy3+ were determined by measuring the absorption and luminescence spectra in the visible region. The UV–Vis–NIR spectrophotometer analysis indicated the presence of eight inhomogeneous transition bands in various positions and intensities with hypersensitive transition at 1260 nm (6H15/2 → 6F11/2). The experimental oscillator strength (fexp) for each calculated absorption band showed higher magnitudes at hypersensitive transition. The optical energy band gap in the current work showed a decrease in values with increasing ion concentrations. The luminescence spectra of the prepared glass phosphors showed three unique transitions at 4F9/2 → 6H15/2 (490 nm), 4F9/2 → 6H13/2 (585 nm) and 4F9/2 → 6H11/2 (689 nm).

Structural characterization and luminescence properties of Dy3+ doped Ca3MgSi2O8 phosphors

Different concentrations of Dy3+ doped Ca3MgSi2O8 phosphors were synthesis by solid state reaction method. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermoluminescence (TL) and photoluminescence (PL) were carried out. The absorption band located at 351 nm is a main excitation peak matching with the emission of near white light emitting diodes ultraviolet light (400–700 nm). The emission spectra consist mainly group of three emission bands, which are situated around 482 nm, 493 nm (both correspond to blue emission) and 574 nm (correspond to yellow emission). These bands can be assigned to the transitions 4F9/2 → 6H15/2 and 4F9/2 → 6H13/2, respectively. The concentration quenching effect for Dy3+ was found at the optimum doping concentration of 2.0 mol %. The thermoluminescence results show that the corresponding increase or decrease in afterglow is associated with trap density, but no change in trap depth. The underlying reason of photoluminescence and afterglow property is discussed. The prepared phosphor may be useful for eco-friendly lighting technology.