Near-ultraviolet Excitation Research Articles

Insight into a Eu2+-activated zirconium-silicate yellow phosphor for multifunctional applications

To better meet the needs of modern science and technology for new inorganic functional materials, the exploration of new Eu2+-doped phosphors is of great significance. In this work, a zirconium-silicate yellow phosphor, K2ZrSiO5:Eu2+, was explored through theoretical calculations and systematic experiments for use in multifunctional applications. The crystal structure, electronic structure, photoluminescence (PL) and cathodoluminescence (CL) properties of K2ZrSiO5:Eu2+ were investigated in detail. As a result, owing to the open framework and the lattice with the covalent connection, K2ZrSiO5:Eu2+ phosphor exhibits strong yellow light emission under the near-ultraviolet and electron beam excitation. However, the K2ZrSiO5:Eu2+ phosphor suffers a poor thermal stability. Furthermore, the K2ZrSiO5:Eu2+ phosphor exhibits good anti-saturation and anti-aging characteristics under the electron beam excitation. The results indicate that the development of K2ZrSiO5:Eu2+ phosphor can provide a new insight into discovering multifunctional materials.

Emissions of Er3+ and Yb3+ co-doped SrZrO3 nanocrystals under near-infrared and near-ultraviolet excitations

In this study, the upconversion (UC) emissions of Er3+ and Yb3+ co-doped SrZrO3 nanocrystals (NCs) were investigated in terms of the thermal annealing temperature and concentration of Er3+ ions and compared with the emissions under a near-ultraviolet (near-UV) excitation. The NCs were synthesized by the combustion method, and the as-synthesized NCs were post-annealed at high temperatures. The X-ray diffraction patterns revealed that the grain sizes and crystallinity degrees of the samples increased with increasing annealing temperatures. The photoluminescence spectra of our samples exhibited strong green and very weak red emissions with the near-UV excitation, originating from the f-f transitions in the Er3+ ions. Interestingly, under near-infrared (near-IR) excitation, we identified sizable visible emissions at 525, 547, and 660 nm in our NCs, which indicated that the UC process successfully occurred in our NCs. These UC emissions were maximized in the NCs with an Er3+ concentration of 0.02 and thermal annealing at 1000 °C. We found that the intensity ratios of red to green emissions increased with increasing annealing temperatures. We discussed the differences in the emissions between near-UV and near-IR excitations.

Synthesis and Luminescence Properties of SrGd2O4:Eu3+ Red Phosphors

As one of the important raw materials for LED products, phosphors play an important role. At present, the spectrum of LED phosphors lacks red light, resulting in poor quality of white LED products and a low color rendering index (Ra <80), which affects lighting effects. To solve this problem, we synthesized the SrGd2O4:Eu3+ red phosphor by a high-temperature solid-phase method. The structure and luminescence properties of SrGd2O4:Eu3+ red phosphors were studied by means of X-ray diffraction (XRD) measurements of their emission and excitation spectra, and their spectra were analyzed. We also studied the Eu3+ doping concentration with the best luminous efficiency and the color coordinate of the SrGd2O4:Eu3+ phosphor. The experimental results show that SrGd2O4:Eu3+ is a new red phosphor material that can be used for near-ultraviolet or blue-light excitation and has good practicability.

Promising green Sr5B3O9F: Ce3+/ Tb3+/Na+ phosphors for NUV-executable LED applications

Abstract Green phosphors such as Sr5-3(x+y)/2CexTbyB3O9F (x = 0.1, y = 0.4) and Sr5-x-y-zCexTbyNazB3O9F (x = 0.1, y = 0.4, z = 0.1, 0.4, 0.5) were prepared via solid-state reactions. The X-ray diffraction patterns of the obtained phosphors were examined to properly index their peak positions. Enhanced photoluminescence (PL) excitation and emission spectra were observed when Na+ and Ce3+ were co-doped into the Sr5B3O9F:Tb3+ phosphors. An intense green light due to the prepared phosphors was observed in the emission spectra upon near-ultraviolet (NUV) excitation. Scanning electron microscopy (SEM) images of the luminescent particles were obtained and the green emission light of a Sr4Ce0.1Tb0.4Na0.5B3O9F phosphor was compared to that of commercially available green phosphate and silicate phosphors. The thermal quenching of such phosphor occurred at 298–448 K. In addition, the internal quantum efficiency, color rendering index, correlated color temperature, and Commission Internationale de l’Eclairage coordinates were characterized for the Sr4Ce0.1Tb0.4Na0.5B3O9F phosphor using a 365 nm LED chip.

Tunable luminescence and morphological evolution of facile synthesized zinc borate/carbon dots composites for NUV-WLEDs

Abstract A series of zinc borate/carbon dots composites (ZBH/yNCDs) were successfully synthesized under hydrothermal conditions. The influences of yellow N-doped carbon dots (yNCDs) content on the structure, morphologies and luminescence properties of the zinc borate (4ZnO·B2O3·H2O, ZBH) were investigated. With increasing yNCDs content, ZBH in the ZBH/yNCDs composites gradually lost water and eventually became ZB/yNCDs (4ZnO·B2O3, ZB) composites. Meanwhile, the tunable luminescence of ZBH/yNCDs composites and the morphological evolution from rod-like to block to sphere-like were achieved by varying the yNCDs content in the zinc borate matrix. The results revealed that the ZBH/yNCDs composite with sphere-like morphology has the strongest white light emission at 395 nm excitation wavelength. Therefore, the ZBH/yNCDs composites may be used as phosphors in the near-ultraviolet (NUV) excitation white-light illumination field. The discovery of this work may also provide new inspirations for solving the self-quenching effect of carbon dots in the solid-state display applications.

Eu3+-activated Ca3Mo0.2W0.8O6 red-emitting phosphors: A near-ultraviolet and blue light excitable platform for solid-state lighting and thermometer

Eu3+-activated Ca3Mo0.2W0.8O6 phosphors, which presented bright red emissions mainly from the 5D0 → 7F2 transition of Eu3+ ions upon the near-ultraviolet and blue light excitation, were successfully prepared by a traditional high-temperature technology. The crystal structure, phase constitution, morphology, electronic structure, photoluminescent behaviors, decay time, internal quantum efficiency and thermal stability of the resultant phosphors were investigated in detail. Under the excitation of 365, 393 and 465 nm, the optimal doping concentration was 9 mol% and the electrical multipolar interaction contributed to the non-radiative energy transfer between Eu3+ ions in Ca3Mo0.2W0.8O6 host lattices. Additionally, through using the prepared compounds, commercial blue/green-emitting phosphors and light-emitting diodes (LEDs), the fabricated white-LEDs emitted warm white light with excellent performance, such as good CIE coordinates, high color rending index and low correlated color temperature, when driven by 30 mA of injection current. Ultimately, according to the response of the decay time to the temperature, the thermometric performances of the resultant phosphors in the temperature range of 298–573 K were studied. The maximum sensor sensitivity of the studied phosphors reached up to 1.16% K−1 at 523 K. These achievements revealed that Eu3+-activated Ca3Mo0.2W0.8O6 phosphors were promising candidates for solid-state lighting and thermometer.

Effect of fluxes on luminescence properties of color-tunable Ba1.3Ca0.7SiO4:Eu2+, Mn2+ Phosphor for Near-Ultraviolet White-LEDs

Eu2+/Mn2+-codoped Ba1.3Ca0.7SiO4 (BCS), a promising single-phase and white-light-emitting phosphor, is prepared by the solid-state reaction at a calcination temperature of 1000 °C for 2 h by adding SrCl2, CaCl2, KCl, NaCl, NH4Cl, Li2CO3, BaF2, CaF2, and BaCl2 as fluxes. The samples are characterized by X-ray diffraction and photoluminescence spectroscopy. The emission wavelength and color-rendering index (CRI) can be tuned by adjusting the amount of the BaCl2 flux and are influenced by the different flux types. NH4Cl exhibits the best fluxing effect for the Mn2+ ion doping probably because the formed eutectic mixtures of BaCl2–CaCl2 during the reaction process promote the reaction. The phosphors produced by adding a SrCl2 flux exhibit the highest CRI of 87.2 with Commision International de I’Eclairage (CIE) chromaticity coordinates of (0.347, 0.343) in the white region under near-ultraviolet light excitation.

Synthesis, structure and luminescence of a high-purity and thermal-stable Sr9LiMg(PO4)7: Eu3+ red phosphor

Eu3+-activated Sr9LiMg(PO4)7 phosphors, which presented bright red emissions mainly from the 5D0→7F2 transition of Eu3+ ions upon the near-ultraviolet excitation, were successfully synthesized in ambient atmosphere. The crystal structure, phase constitution, photoluminescent behaviors, decay time, internal quantum efficiency and thermal stability of the resultant phosphors were investigated in detail. Eu3+ ions are found to tend to occupy multiple Sr2+ sites, which are 7, 8 and 10-coordinated. The optimal doping concentration is 7 mol% and the electrical multipolar interaction contributed to the non-radiative energy transfer between Eu3+ ions in Sr9LiMg(PO4)7 host lattices. Temperature-dependent PL spectra indicated Sr9LiMg(PO4)7: Eu3+ possess excellent emission and color stability at elevated temperature. Fabricated single-chromatic LED prototype emit bright red light under 20 mA bias current, which demonstrates that Sr9LiMg(PO4)7: Eu3+ phosphor is of great potential as converted phosphor in NUV LED application.

Efficient blue-white color luminescence with near-ultraviolet excitation in Dy3+/Tm3+:Na3Gd(PO4)2 nanophosphor for white LEDs

The Dy3+, Tm3+ ions activated, and Dy3+/Tm3+ ions co-activated Na3Gd(PO4)2 phosphors were synthesized by the citrate-gel based combustion technique. The structural properties of as-synthesized phosphors were studied through X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). The influence of Tm3+ concentration on the fluorescence properties of Na3Gd(PO4)2:Dy3+/Tm3+ phosphors were systematically investigated under near-UV light irradiation of 359 and 352 nm. The energy transfer efficiency (ηET) of as-prepared phosphors increases gradually from 17 to 42%, and the critical distance (Rc) between Dy3+ and Tm3+ ions is calculated to be 4.76 Å. For better understanding the energy transfer mechanism (ET:Dy3+ →Tm3+), the decay curves were utilized on the basis of Dexter's energy transfer formula and Reisfeld's approximation. More importantly, the obtained CIE color coordinates of Na3Gd(PO4)2:Dy3+/Tm3+ phosphors located at blue-white region under near-UV light irradiation. The results demonstrate the promising application of Na3Gd(PO4)2:Dy3+/Tm3+ phosphor for near-UV white LEDs.

Photoluminescence properties, Judd-Ofelt analysis, and optical temperature sensing of Eu3+-doped Ca3La7(SiO4)5(PO4)O2 luminescent materials.

A series of Eu3+-doped Ca3La7(SiO4)5(PO4)O2 (CLSPO) multifunctional phosphors were synthesized by a high-temperature solid-state reaction method. The crystal structure of the CLSPO host was explored using Rietveld refinement. The photoluminescence properties of CLSPO: Eu3+ phosphors were investigated systematically. Upon 392nm near-ultraviolet light excitation, the phosphor exhibited strong characteristic emissions of Eu3+ ions with a dominant red emission peak around 613nm, indicating its potential use in solid-state lighting. Calculations of Ω2 and Ω4 Judde-Ofelt intensity parameters provided insight into the structure-luminescence correlation in the CLSPO: Eu3+ system. By exploring the temperature sensitivity of photoluminescence intensity, the application potential of the sample to optical thermometry was studied.

Intense green‐, red‐emitting Tb3+, Tb3+/Bi3+‐doped and Sm3+, Sm3+/La3+‐doped Ca2Al2SiO7 phosphors

This paper focuses on an optical study of a Tb3+ /Bi3+ -doped and Sm3+ /La3+ - doped Ca2 Al2 SiO7 phosphor synthesized using combustion methods. Here, Ca2 Al2 SiO7 :Sm3+ showed a red emission band under visible light excitation but, when it co-doped with La3+ ions, the emission intensity was further enhanced. Ca2 Al2 SiO7 :Tb3+ shows the characteristic green emission band under near-ultraviolet light excitation wavelengths, co-doping with Bi3+ ions produced enhanced photoluminescence intensity with better colour tunable properties. The phosphor exhibited better phase purity and crystallinity, confirmed by X-ray diffraction. Binding energies of Ca(2p), Al(2p), Si(2p), O(1s) were studied using X-ray photoelectron spectroscopy. The reported phosphor may be a promising visible light excited red phosphor for light-emitting diodes and energy conversion devices.

Efficient green-emitting Ca2GdZr2Al3O12:Ce3+,Tb3+ phosphors for near-UV-pumped high-CRI warm-white LEDs

In this work, we reported novel efficient Ce3+/Tb3+ co-doped Ca2GdZr2Al3O12 (CGZA) green-emitting phosphors by traditional solid state method. The phase purity, crystal structure, morphology, photoluminescence properties, internal quantum efficiencies (IQEs), and thermal stability of the samples were systematically investigated. The obtained results revealed that there was an obvious spectral overlap between the emission spectrum of Ce3+ singly doped CGZA phosphors and excitation spectrum of Tb3+ singly doped CGZA phosphors, and efficient energy transfer from Ce3+ to Tb3+ ions existed in Ce3+ and Tb3+ co-doped CGZA phosphors. The Ce3+→Tb3+ energy transfer mechanism was ascribed to the dipole-dipole interaction. The CGZA:Ce3+,Tb3+ phosphors exhibited a broad excitation spectrum in the wavelength range of 370–470 nm with a maximum at 408 nm corresponding to the spin-allowed 4f-5d transition of Ce3+ ions. Upon near-ultraviolet (near-UV) excitation at 408 nm, the composition-optimized CGZA:0.02Ce3+,0.8 Tb3+ sample showed intense sharp narrow-line emissions at 485, 543, 591, 629, 643, 663, and 679 nm due to the 5D4→7FJ (J = 6–0) transitions of Tb3+ ions, along with a good IQE of 51%. Lastly, a white light-emitting diode (LED) device was fabricated by using as-prepared CGZA:0.02Ce3+,0.8Tb3+ green phosphors, commercial BaMgAl10O17:Eu2+ blue phosphors, and CaAlSiN3:Eu2+ red phosphors, and under 300 mA driven current it gave bright warm-white light with a low correlated color temperature of 3969 K and a high color rendering index (Ra = 91.2). Our work provides a new perspective for the design and fabrication of efficient color conversion materials toward near-UV LED-based warm-white LEDs.

Tunable dual‐mode emission with excellent thermal stability in Ca4ZrGe3O12:Eu phosphors prepared in air for NUV‐LEDs

AbstractNovel dual valence Eu‐doped Ca4ZrGe3O12 (CZGO) phosphors were successfully fabricated in air atmosphere through a solid‐state route. Their crystal structure, photoluminescence properties as well as thermal quenching performance were investigated systematically. The spectra show that part of Eu3+ were reduced to Eu2+ and the mechanism is interpreted by the charge compensation. By altering Eu concentration, multi‐color luminescence covering from blue to red is realized when irradiated by 370 nm light, which perfectly matches with the near ultraviolet (NUV) light‐emitting diode (LED) chips. More importantly, under NUV excitation, luminescent intensities are almost unchanged even up to 423 K. And chromaticity exhibits only a tiny shift with growing temperature. Such suitable luminescent spectra and superior thermal stability indicate that CZGO:Eu phosphors are promising candidates for blue‐red components in NUV pumped W‐LEDs. Finally, the fabricated W‐LED based on the combination of CZGO:Eu phosphors, Ba2SiO4:Eu2+ and a 365 nm NUV‐LED chip gives a high color rendering index, a low correlated color temperature and suitable CIE chromaticity coordinates.

Energy transfer and tunable luminescent properties in Eu2+/Tb3+/Eu3+ co-doped oxyfluoride aluminosilicate glass

A series of Eu2+/Tb3+/Eu3+ co-doped oxyfluoride aluminosilicate glass samples were synthesized by using the melt-quenching method in air atmosphere. Transmission spectra, excitation and emission spectra, decay curves and temperature-dependent emission spectra were utilized to investigate their luminescent properties systematically. Under near-ultraviolet excitation, adjustable white light emission is generated as a result of efficient energy transfer from Eu2+ to Tb3+ and from Tb3+ to Eu3+. Furthermore, the Eu2+/Tb3+/Eu3+ co-doped glass presents good thermal stability. At 423 K, the emission intensity of the optimal G-5Tb4Eu glass remains about 86% of its initial intensity at 298 K. These excellent properties indicate that Eu2+/Tb3+/Eu3+ co-doped oxyfluoride aluminosilicate glass may provide a new platform for designing and fabricating W-LEDs devices in the future.

Reddish-orange light emission via combustion synthesized Ba3Y4O9: Sm3+ nanocrystalline phosphor upon near ultraviolet excitation

A highly efficient solution combustion technique involving simple procedure and less energy consumption was adopted to prepare a homogeneous crystalline Ba3Y4O9:Sm3+ down-conversion nanophosphor emitting bright reddish orange light. The structural features of the synthesized nanophosphors were characterized by powder X-ray diffraction (PXRD), scanning electron microscope (SEM), transmission electron microscope (TEM), high resolution transmission electron microscope (HRTEM), selected area energy diffraction (SAED) and energy-dispersive X-ray analysis (EDAX) techniques. Moreover, the photoluminescent features of the nanocrystalline phosphors were described by photoluminescence decay curves, excitation and emission spectra. Upon near-ultraviolet (NUV) excitation (410 nm), the emission spectra demonstrate the most prominent peak at 607 nm due to 4G5/2 → 6H7/2 transition. The optimum mol% of dopant (Sm3+) ion for doping in this particular host matrix was found to be 3; thus, a concentration quenching (CQ) phenomenon was observed beyond x = 0.03 in the synthesized Ba3Y4(1-x)O9: 4x Sm3+ nanophosphors. The most appropriate reason for CQ mechanism was reckoned to be radiative-reabsorption phenomenon and dipole-dipole (d-d) interactions. The CIE chromaticity coordinates for the optimum nanophosphor were found to lie in orange-red region that confirm its characteristic light emission. The results indicate the promising applications of the synthesized reddish-orange light emitting Ba3Y4O9: Sm3+ nanophosphor in white light emitting diodes (WLEDs).

Synthesis and photoluminescence properties of KZnPO4: Dy3+, Sm3+

A series of Dy3+/Sm3+ co-doped KZnPO4 phosphors were synthesized by the conventional solid-state reaction method. The crystal structure, luminescent characteristic and lifetime were studied by X-ray diffraction, photoluminescence properties and decay life. Dy3+/Sm3+ co-doped and Sm3+ doped KZnPO4 phosphors exhibited high crystallinity in structure from XRD results. Under the ultraviolet (UV) or near-ultraviolet (NUV) excitation, KZnPO4: Dy3+, Sm3+ phosphors emitted adjustable color coordinates light by changing the content of Sm3+ ions, which indicated the phosphors might be of potential application in display and lighting. The optimum Sm3+ concentration is 0.005. Furthermore, energy transfer from Dy3+ to Sm3+ was confirmed by the emission spectra and the decay time of co-doped phosphors.

Synthesis and luminescence properties of single-phase Ca2P2O7:Eu2+, Eu3+ phosphor with tunable red/blue emission

A series of Eu2+ and Eu3+ coexisting Ca2P2O7 phosphors with tunable red/blue (R/B) emission have been successfully synthesized by a two-step method. Phase composition, luminescence properties and surface states are investigated by the X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), photoluminescence (PL) emission spectra, fluorescence quantum efficiency, fluorescent lifetime and X-ray photoelectron spectroscopy (XPS). It can be concluded from XRD and FTIR results that pure Ca2P2O7 phase can be obtained at 900 °C and Ca3(PO4)2 impurity phase occurs at an increasing preparation temperature (1100 °C). The XRD results confirm that the Eu2+or Eu3+ doped samples all exhibit pure tetragonal Ca2P2O7 crystal with space group P41. Under excitation of 330 nm, Eu2+ singly-doped Ca2P2O7 phosphors showed a broad blue emission band at 422 nm, while the Eu3+ single-doped samples emitted a strong orange-red light with wavelength of 591, 597 and 618 nm excited by 395 nm. In particular, oxygen vacancies in pure Ca2P2O7 crystal are found due to the strong PL emission at 420 nm. Furthermore, Eu2+/Eu3+ co-doped Ca2P2O7 phosphors prepared by this two-step synthesis show the blue emission at 422 nm (Eu2+ ions) and the orange-red emission (Eu2+ ions) at 591 nm, 597 nm and 618 nm under near-ultraviolet (NUV) excitation of 380 nm. It was detected that the quantum efficiency of the Ca1.88P2O7:0.12Eu phosphor was 37.7%. The tunable R/B emission ratio from 0.13 to 1.56 can be achieved by controlling the recalcined temperature in the second step when excited by 380 nm. The XPS demonstrate the existence of Eu3+ ions on the surface of Eu2+/Eu3+ co-doped Ca2P2O7 phosphors. Under NUV excitation in the range from 350 to 400 nm, the optimum Commission International de I’Eclairage (CIE) coordinate of Ca2P2O7:0.12Eu2+/Eu3+ phosphors is (0.3648, 0.215), which can be potentially used as an emitting source to meet the needs of illumination devices.

Novel high color purity phosphors Sr9Mg1.5(PO4)7: Sm3+, R+(R = Li, Na, K): Crystal structure, luminescence and thermal quenching property investigation

A series of novel orange-red phosphors Sr9Mg1.5(PO4)7: xSm3+ were synthesized by high temperature sintering method. Rietveld refinement, X-ray diffraction patterns, photoluminescence spectra, decay times and luminescence spectra showing thermal quenching were measured and investigated in detail. The mechanism of interaction for energy transfer, CIE chromaticity coordinates and color purity of the phosphors were studied and discussed, too. According to the Rietveld refinement, the coordination numbers of Sr2+ were reconfirmed based on the refined structure for the first time. Moreover, it was found that under near-ultraviolet excitation, Sr9Mg1.5(PO4)7: xSm3+ exhibited an intense orange-red emission centering at 598 nm and 650 nm which can be assigned to 4G5/2 to 6H7/2 and 6H9/2 energy level transitions of Sm3+, respectively. The CIE chromaticity coordinates of Sr9Mg1.5(PO4)7: 0.2Sm3+ was (0.6066, 0.3923) with outstanding color purity of 98.8%. The sample also exhibited good thermal quenching properties with the remained 70% emission intensity at 150 °C compared with that at ambient temperature. Furthermore, in order to further improve the luminescent intensity and the thermal stability, Li+, Na+ and K+ were incorporated into Sr9Mg1.5(PO4)7:0.2Sm3+ as the compensator charges. Among all the samples with compensator charges, Sr9Mg1.5(PO4)7:0.2Sm3+, 0.2Na+ presented the highest emission intensity and best temperature quenching properties because of the similar radius of Na+ and Sr2+. The improved and linear thermal stability and strong luminescence intensity suggested that Sr9Mg1.5(PO4)7:0.2Sm3+, 0.2Na+ has a potential use in solid-state lighting.

Luminescence enhancement for Y2Mo4O15:Pr3+ red-emitting phosphors by Tb3+ co-doping

A series of Y2Mo4O15:Pr3+, Tb3+ red-emitting phosphors is synthesized via a solid-state reaction. The X-ray diffraction results indicate that the patterns of Y2Mo4O15:Pr3+, Tb3+ samples match well with the standard Y2Mo4O15 monoclinic structure. Under blue excitation at 453 nm, the Y2Mo4O15:Pr3+ phosphors show a red emission peaked at 614 nm, corresponding to the characteristic 1D2 → 3H4 electronic transition of Pr3+. Under near-ultraviolet excitation at 375 nm, the Y2Mo4O15:Tb3+ phosphor results in a double emission at 552 nm and 490 nm, which corresponding to the 5D4 → 7F5 and 5D4 → 7F6 electronic transitions of Tb3+. Furthermore, the luminescence properties of Y2Mo4O15:Pr3+ phosphor, especially luminescence intensity, was observably improved by the Tb3+ co-doping, which due to the emission peak of Tb3+ matches well with the excitation peak of Pr3+ at 490 nm and the resulted energy transfer between Tb3+ and Pr3+. The chromaticity coordinates of Y2Mo4O15:Pr3+, Tb3+ phosphors are all located in the red region. The results indicate that the prepared Y2Mo4O15:Pr3+, Tb3+ red phosphors are suitable for the applications of blue-excited warm white light-emitting diodes.

Study on Na3Lu1-xEux(PO4)2 phosphor: High efficient Na3Eu(PO4)2 red emitting phosphor with excellent thermal stability

High efficient Na3(Lu1-xEux)(PO4)2 orthophosphates phosphors were synthesized by conventional solid state reaction method. The obtained phosphors crystallized in the orthorhombic system with the space group Pca21. Since the crystal structure of the phosphor is composed of isolated PO4 tetrahedra, the average distance between rare earth ions was distant. As the concentration of Eu3+ activator ion reaches to 100%, reduced Judd-Ofelt parameter ratio of Ω2/Ω4 implies the improvement of the symmetry environment around Eu3+ ion and from the prolonged lifetime of 5D0→7F2 transition we inferred no-concentration quenching in this phosphor. Furthermore, due to the better crystallinity of Na3Eu(PO4)2 phosphor compared to the mixed crystals Na3(Lu1-xEux)(PO4)2, the internal quantum efficiency of the Na3Eu(PO4)2 phosphor reaches the high value up to 99% under near-ultraviolet (393 nm) excitation. Temperature dependent emission spectra revealed that Na3Eu(PO4)2 phosphor possesses stable emission of 80% at 423 K compared to room temperature. Due to high quantum efficiency and excellent thermal stability, Na3Eu(PO4)2 has potential application as reddish-orange phosphors.