Site construction of Eu2+ and sensitized luminescence of Eu3+ in LaF3:Eu nanophosphor

LaF₃:Eu nanophosphors were prepared by a traditional hydrothermal method with citric acid as a reducing agent. X-ray diffraction, scanning electronic microscopy, and luminescence spectroscopy were used to study the nanophosphors. The formation of three different luminescence centers of Eu²⁺ and two different luminescence centers of Eu³⁺ is attributed to the existence of abundant surface defects in this nanophosphor. Eu³⁺ is effectively excited by energy transfer from Eu²⁺ to Eu³⁺. The excitation wavelength of Eu³⁺ covers a broad spectral range from 250 to 480 nm. The nanophosphor shows a tunable luminescence color varying from blue to white and then to red, which is explained from three aspects of Eu concentration, energy transfer, and concentration quenching. Utilizing the surface defect of nanoparticles to control the reduction of Eu³⁺ is considered a promising strategy for exploring Eu²⁺ and Eu³⁺ codoped phosphor suitable for the lighting and display application.     

Photoluminescence characteristics and mechanism of SrAl2O4 co-doped with Eu3+ and Cu2+

SrAl₂O₄ co-doped with Cu²⁺ and Eu³⁺ was prepared at high temperature in a weakly oxidizing atmosphere by solid states reaction. X-ray diffraction (XRD) pattern of the sample shows that the doped sample exhibits SrAl₂O₄ crystalline phase. No characteristic peaks of dopant have been observed in XRD pattern of doped sample. The excitation and emission spectra of CuEu:SrAl₂O₄, Eu:SrAl₂O₄, Cu:SrAl₂O₄ samples consist of many sharp peaks. The excitation and emission spectra of the SrAl₂O₄ sample co-doped with Cu²⁺ and Eu³⁺ are significantly different from those of Eu:SrAl₂O₄ and Cu:SrAl₂O₄ samples. The novel photoluminescence (PL) characteristic of the co-doped sample is attributed to the composite luminescence of Cu²⁺ and Eu³⁺ ions in SrAl₂O₄ matrix.     

Improving white light emission and quantum yield of Ce@Eu co-doped silicate glass by reducing Eu3+ to Eu2+ with Si3N4

Rare-earth-doped transparent glass shows great potential in white light-emitting diodes (wLEDs) application due to its excellent optical and luminous properties. Currently reported commercial wLEDs have a drawback in red emission missing, which leads to a relatively low color rendering index (CRI) and a relatively high correlated color temperature (CCT). In this work, Ce@Eu Sr–Si–O glass is fabricated using a high-temperature quenching method. The white light is available when the ratio of Ce³⁺/Eu³⁺ equals 1, and the emitting color can be adjusted from blue to red by controlling the ratio of Ce³⁺/Eu³⁺. To further optimize the white light, Eu³⁺ ions can be reduced to Eu²⁺ according to the reaction of 6Eu³⁺ + 2N³⁻ → 6Eu²⁺ + N₂↑ by introducing Si₃N₄. As a result, the standard white light emission can be achieved in the Ce@Eu silicate glass contributed by the blue light from Ce³⁺, red light from Eu³⁺, and yellow–green light from Eu²⁺ (two elements, three emission). This glass shows excellent luminous properties, such as a color coordinate is (0.3651, 0.3269) in CIE 1931 color coordinate diagram, a CRI is over 70, a high quantum yield of 36.02%, and a CCT of 4117 K.     

Color-tunable properties of Eu3+- and Dy3+-codoped Y2O3 phosphor particles

Rare-earth phosphors are commonly used in display panels, security printing, and fluorescent lamps, and have potential applications in lasers and bioimaging. In the present study, Eu³⁺- and Dy³⁺-codoped uniform-shaped Y₂O₃ submicron particles were prepared using the urea homogeneous precipitation method. The structure and morphology of the resulting particles were characterized by X-ray diffraction, field emission scanning electron microscope, and field emission transmission electron microscope, whereas their optical properties were monitored by photoluminescence spectroscopy. The room-temperature luminescence color emission of the synthesized particles can be tuned from red to yellow by switching the excitation wavelength from 254 to 350 nm. The luminescence intensities of red and yellow emissions could be altered by varying the dopant concentration. Strong quenching was observed at high Eu³⁺ and Dy³⁺ concentrations in the Y₂O₃ host lattice.     

Eu3+‐Activated Borogermanate Scintillating Glass with a High Gd2O3 Content

Eu³⁺‐activated borogermanate scintillating glasses with compositions of 25B₂O₃–40GeO₂–25Gd₂O₃–(10?x)La₂O₃–xEu₂O₃ were prepared by melt‐quenching method. Their optical properties were studied by transmittance, photoluminescence, Fourier transform infrared (FTIR), Raman and X‐ray excited luminescence (XEL) spectra in detail. The results suggest that the role of Gd₂O₃ is of significance for designing dense glass. Furthermore, energy‐transfer efficiency from Gd³⁺ to Eu³⁺ ions can be near 100% when the content of Eu₂O₃ exceeds x = 4, the corresponding critical distance for Gd³⁺–Eu³⁺ ion pairs is estimated to be 4.57 Å. The strongest emission intensities of Eu³⁺ ions under both 276 and 394 nm excitation are simultaneously at the content of 8 mol% Eu₂O₃. The degree of Eu–O covalency and the local environment of Eu³⁺ ions are evaluated by the value of Ω_t parameters from Judd–Ofelt analysis. The calculated results imply that the covalency of Eu–O bond increases with the increasing concentration of Eu³⁺ ions in the investigated borogermanate glass. As a potential scintillating application, the strongest XEL intensity under X‐ray excitation is found to be in the case of 6 mol% Eu₂O₃, which is slightly different from the photoluminescence results. The possible reason may be attributed to the discrepancy of the excitation mechanism between the ultraviolet and X‐ray energy.     

Combustion Synthesis of Ca2Si5N8: Eu2+ Phosphors and their Luminescent properties

A combustion synthesis method has been developed for synthesis of Eu²⁺‐doped Ca₂Si₅N₈ phosphor and its photoluminescence properties were investigated. Ca, Si, and Eu₂O₃ powders were used as the Ca, Si, and Eu sources. NaN₃ and NH₄Cl were found necessary to be added for the formation of the product phase and addition of Si₃N₄ was found to enhance the product yield. These powders were mixed and pressed into a compact, which was then wrapped up with an igniting agent (Mg + Fe₃O₄). The reactant compact was ignited by electrical heating under a N₂ pressure of 0.7 MPa. Effects of these experimental parameters on the product yield were investigated and a reaction mechanism was proposed. The synthesized Ca₂Si₅N₈: Eu²⁺ phosphor absorbs light in the region of 300–520 nm and shows a broad band emission in the region of 500–670 nm due to the 4f⁶5d¹ → 4f⁷ transition of Eu²⁺. Eu₂O₃ was found partially unreacted and a certain amount of oxygen is believed to be incorporated into the lattice of the product phase. The peak emission intensity (~93% of a commercially available phosphor, YAG:Ce³⁺v) and the peak emission wavelength (571–581 nm) were found to be lower and shorter, respectively, than that reported in the literature. These are considered to be mainly due to oxygen incorporation, which not only reduces nephelauxetic effect and crystal field splitting but also causes a lowering of internal quantum efficiency.     

Effects of Eu content on the luminescent properties of Y2O3:Eu3+ aerogels and Y(OH)3/Y2O3:Eu3+@SiO2 glassy aerogels

This article describes the morphological, structural, and luminescent properties of Y₂O₃:Eu³⁺ aerogels and Y(OH)₃/Y₂O₃:Eu³⁺@SiO₂ glassy aerogels synthesized by the sol-gel method with Eu concentrations from 2.5 mol% to 30 mol%. XRD measurements indicated that both the aerogels and glassy aerogels had a monoclinic phase, but the crystallinity in the glassy aerogels was lower due to the presence of SiO₂. SEM images reveal that a three-dimensional porous network was formed in the aerogels due to the interconnection of coalesced Y₂O₃:Eu³⁺ nanoparticles. The 3D porous network was also observed in the glassy aerogels, coated with a silica shell. In both the aerogels and glassy aerogels, the size of the agglomerates decreased as the europium concentration increased. This, in turn, increased the average size of the macropores that formed their 3D network. Furthermore, the luminescent properties of the aerogels and glassy aerogels were studied under UV excitation, and it was observed that their red emission intensity increased continuously as the Eu³⁺ concentration increased. The luminescence of the aerogels was on average 50% higher than that of the glassy aerogels. Hence, our results indicate that porous and luminescent aerogels with and without silica are adequate for applications in sensing and catalysis.     

Insight into a concentration-sensitive red-emitting phosphor Li2Ca4Si4O13:Eu3+ for multifunctional applications: Crystal structure,electronic structure and luminescent properties

Lithium-containing silicate compounds have attracted so much attention in recent years for applications in energy storage and illumination source due to their rigid structure and good electrical conductivity. In this study, a Eu³⁺ doped lithium-containing silicate red phosphor, Li₂Ca₄Si₄O₁₃:Eu³⁺, was explored by using structural computational simulations and systematic experiments for multifunctional applications. As a result, due to the quite non-central symmetry of the Ca²⁺ sites (C₁ symmetry), the strong 4f-4f excitations in near ultraviolet region were observed. Under near ultraviolet and cathode ray light excitation, Li₂Ca₄Si₄O₁₃:Eu³⁺ phosphor has an efficient red emission with good thermal stability and ageing resistance. Furthermore, Li₂Ca₄Si₄O₁₃:Eu³⁺ phosphor exhibits a concentration-sensitive behavior induced by the change of site symmetry. The results show that it is feasible to develop near-ultraviolet and cathode ray light excited red phosphors in lithium-containing silicate compounds.     

Phase formation and spectral evolution of (Sr,Ba)2Si(O,N)4:Eu2+ phosphors

Sr_2‐xBa_xSi(O,N)₄:Eu²⁺ (SB_xSON:Eu²⁺) oxynitridosilicate phosphors were prepared via incorporation of N^3?, Eu²⁺, and Ba²⁺ ions into Sr₂SiO₄ (SSO) lattices. X‐ray diffraction patterns of the prepared powders revealed that SB_xSON:Eu²⁺ was a solid‐solution form of SSO. An increase in x values caused a phase transition and an expansion of the unit cell. The photoluminescence excitation (PLE) spectra of SB_xSON:Eu²⁺ were broad, covering the ultraviolet range to the visible range. Corresponding PL emission spectra strongly depended on the excitation wavelengths and consisted of two emission bands, one in the green‐blue region (A‐band) and the other in the red region (B‐band), which were assigned to Eu(I) and Eu(II), respectively. The B‐band resulted from a dramatic red‐shift of the green emission band assigned to Eu(II) of SSO:Eu²⁺, revealing that the nitridation process preferentially affected the Eu(II) sites. This behavior was explained by crystal field splitting, the fluorescence decay time, and thermal quenching. The Ba²⁺ substitution caused evolution of the PL spectra, and its effects on the spectra were discussed under consideration of ionic size and covalence.     

Unusual concentration induced antithermal quenching of the Eu2+ emission at 490 nm in Sr4Al14O25:Eu2+ for near ultraviolet excited white LEDs

Thermal quenching of phosphor is an important challenge for its practical application in phosphor-converted white light-emitting diodes (pc-WLEDs) and it usually becomes aggravated with the increase of activator concentration. Conversely, this work finds the thermal quenching of Eu²⁺ emission at 490 nm in Sr₄Al₁₄O₂₅:Eu²⁺ does not follow this in the temperature range of 300 to 480 K, and the rate of it is even slowed down as the concentration of Eu²⁺ increases. However, at the same time, the experiment on three heating-cooling cycles of Sr₄Al₁₄O₂₅:Eu²⁺ reveals that the thermal degradation of Eu²⁺ emission becomes improved. Once Eu²⁺ ions are doped into Sr₄Al₁₄O₂₅, they will prefer substituting for the 10- and 7-coordinated strontium sites Sr1 and Sr2, respectively. The emission centers Eu1 and Eu2, therefore, appear. The abnormal phenomenon is perhaps partly due to the enhanced energy transfer from the emission center Eu1 at 407 nm to the one Eu2 at 490 nm. It is also found interesting that the introduction of AlN can enhance the emission of Sr₄Al₁₄O₂₅:Eu²⁺ without leading to the deterioration of thermal degradation. In the end, a prototype of pc-WLED was fabricated with Sr₄Al₁₄O₂₅:Eu²⁺ to demonstrate the application of white lighting. This work is not only beneficial to the understanding of the relationship between concentration and thermal quenching, but also conducive to the design of the heavily doped phosphor for WLEDs with better resistance to thermal quenching.     

Solvothermal synthesis of columnar Gd2O2S:Eu3+ and a comparative study with columnar Gd2O3:Eu3+

Columnar Gd₂O₂S:Eu³⁺ nanophosphors have been synthesized through solvothermal reaction and subsequent calcination process. The structure, morphology, and luminescence properties of samples were investigated via X-ray diffraction (XRD), Fourier transform infra-red (FT-IR) spectra, UV-vis absorption spectra, field emission scanning electron microscope (FE-SEM), and photoluminescence (PL) spectra. The Judd-Ofelt (J-O) parameters of Gd₂O₂S:Eu³⁺ nanophosphors with different doping concentration were calculated by emission spectra to understand the symmetry, coordination environment, and luminescence behavior of Eu³⁺ ions in Gd₂O₂S matrix. In addition, the luminescence properties of columnar Gd₂O₂S:Eu³⁺ and Gd₂O₃:Eu³⁺ were compared in detail. The comparison results show that there are subtle differences in luminescence intensity, main peak position, luminescence color, and fluorescence lifetime between them, which are closely related to their different substrate's structure, including the band-gap energy, crystallinity, and symmetry, etc.     

Self-reduction of Eu3+ to Eu2+ in europium-doped Li2B4O7 glass prepared in air

Motivated by the detection of neutrons, europium-doped Li₂B₄O₇ glasses enriched with both lithium and boron elements with high cross-section capture were developed. A highly effective method of realizing the self-reduction of Eu³⁺ to Eu²⁺ ions in europium-doped Li₂B₄O₇ glasses prepared by high temperature melt-quenching technology in air was revealed. The self-reduction of Eu³⁺ to Eu²⁺ ions can be easily achieved by the partial replacement of B₂O₃ with BN within 2 mol% concentration. And the effect of partially replacing B₂O₃ with BN on the optical properties of europium-doped Li₂B₄O₇ glass are systematically studied by transmittance, photoluminescence, and radioluminescence spectra, together with the luminescence decay curves.     

Photoluminescence properties of Eu3+-doped stalk-like Al2O3 via a hydrothermal route followed by heat treatment

ABSTRACT

Uniform Al₂O₃:Eu³⁺ samples were successfully fabricated via a hydrothermal method and subsequent thermal decomposition of Eu³⁺-doped precursors. The sample characterisations were carried out by means of X-ray diffraction (XRD), scanning electron microscope (SEM) and photoluminescence spectra. XRD results revealed Eu³⁺-doped samples were a pure γ-Al₂O₃ phase after being calcined at 1173?K. SEM results showed that these Eu³⁺-doped Al₂O₃ samples were stalk-like, with an average length of 1.5?μm. Upon excitation at 394?nm, the orange–red emission bands, having wavelengths longer than 580?nm, were to be from ⁵D₀→⁷F_J (J?=?1, 2) transitions. The asymmetry ratio of (⁵D₀→⁷F₂)/(⁵D₀→⁷F₁) intensity is about 0.54, 2.76, 3.29, 2.86, 3.36, 3.13 for Eu³⁺ concentrations of 0.1, 0.4, 0.7, 1.0, 1.5 and 2.0?mol-%, respectively. The optimal doping concentration of Eu³⁺ ions in Al₂O₃ is 1.5?mol-%. According to Dexter's theory, the critical distance between Eu³⁺ ions for energy transfer was determined to be 14?Å.     

Difference in the Nature of Eu3+ Environment in Eu3+‐Doped BaTiO3 and BaSnO3

BaTiO₃ and BaSnO₃ samples doped with Eu³⁺ ions were prepared using glycine‐nitrate gel combustion method. Relative intensities and line shapes of magnetic dipole allowed ⁵D₀ → ⁷F₁ and electric dipole allowed ⁵D₀ → ⁷F₂ transitions of Eu³⁺ from the hosts, BaTiO₃ and BaSnO₃, are significantly different. Based on detailed structural investigations, it is confirmed that synthesizedBaTiO₃ sample is tetragonal with no center of symmetry around Ba²⁺ ions. Unlike this BaSnO₃ is cubic with centrosymmetric Ba²⁺ site. From X‐ray diffraction and experimentally obtained Judd–Ofelt parameters (Ω₂ and Ω₄ values), it is confirmed that in BaTiO₃ there is a decrease in the average Ba–O and Ba–Ba distances compared with that in BaSnO₃. This leads to higher Eu–O bond polarizability and adds to the distortion in its environment around Eu³⁺ in BaTiO₃:Eu compared with BaSnO₃:Eu. This is responsible for the observed difference in the luminescence properties.     

Synthesis and photoluminescence properties of Eu2+/Eu3+ or Ce3+/Eu3+ co-doped Sr5(BO3)3F compounds

The synthesis and photo-luminescence properties of Eu²⁺/Eu³⁺ or Ce³⁺/Eu³⁺ co-doped Sr₅(BO₃)₃F compounds are reported. Using the Sr₅(BO₃)₃F as the host, through the solid state reaction under the reductive atmosphere, Eu²⁺/Eu³⁺ and Ce³⁺/Eu³⁺co-doped samples were prepared. These compounds exhibit good photo-luminescence properties. Under the excitation of 376 nm, an unusual red orange emission coming from the Eu²⁺ ions can be obtained in Eu ions doped Sr₅(BO₃)₃F, which exhibits a broadband emission in the range of 450–800 nm with the peak at around 600 nm. At the same time, the characteristic f-f excitation and emission of Eu³⁺ can improve and adjust the Eu²⁺ emission in Eu³⁺/Eu²⁺ codoped Sr₅(BO₃)₃F. In addition, the adjustable luminescence properties from blue to white of Sr₅(BO₃)₃F:Ce³⁺, Eu³⁺ are investigated. The energy transfer behavior from Ce³⁺ to Eu³⁺ was confirmed. In the spectra of the co-doped samples, we can hardly observe the characteristic peak of Eu²⁺, because Ce⁴⁺ can oxidize Eu²⁺ to Eu³⁺, and Ce⁴⁺ itself is reduced to Ce³⁺. The CIE coordinates from (0.2758, 0.2420) to (0.3857, 0.3015) show Sr₅(BO₃)₃F:3%Ce³⁺, x%Eu³⁺ (x = 1,3,5,7,9) are in the white light emission region. All results demonstrate that the Sr₅(BO₃)₃F:Eu³⁺/Eu²⁺ and Sr₅(BO₃)₃F:Ce³⁺/Eu³⁺ phosphors have good application prospects for LED plant growth and white LED, respectively. The bond energy method was used to explain the reason why the Eu²⁺/Eu³⁺ ion instead of only Eu²⁺ and Ce³⁺/Eu³⁺ instead of Ce³⁺/Eu³⁺/Eu²⁺ can exist in the host Sr₅(BO₃)₃F. The theoretical analysis agree well with the experimental result.     

Structure and Luminescence Properties of Eu<Superscript>3+</Superscript>-Doped Cubic Mesoporous Silica Thin Films

Eu³⁺ ions-doped cubic mesoporous silica thin films with a thickness of about 205 nm were prepared on silicon and glass substrates using triblock copolymer as a structure-directing agent using sol–gel spin-coating and calcination processes. X-ray diffraction and transmission electron microscopy analysis show that the mesoporous silica thin films have a highly ordered body-centered cubic mesoporous structure. High Eu³⁺ ion loading and high temperature calcination do not destroy the ordered cubic mesoporous structure of the mesoporous silica thin films. Photoluminescence spectra show two characteristic emission peaks corresponding to the transitions of ⁵D₀-⁷F₁ and ⁵D₀-⁷F₂ of Eu³⁺ ions located in low symmetry sites in mesoporous silica thin films. With the Eu/Si molar ratio increasing to 3.41%, the luminescence intensity of the Eu³⁺ ions-doped mesoporous silica thin films increases linearly with increasing Eu³⁺ concentration.     

A single-phase white-emitting La10(SiO4)6O3：Eu2+/Eu3+ phosphor for near-UV LED-based application

A novel single-phase white-emitting phosphor La₁₀(SiO₄)₆O₃ (LSO): xEu has been synthesized by high-temperature solid-state reaction. Its crystal structure, luminescence properties, fluorescence decay time and oxygen vacancies have been characterized by X-ray diffraction (XRD) and photoluminescence (PL) spectra. XRD result shows a typical oxyapatite structure with the space group of P6₃/m. Characteristic excitation and emission peaks of Eu²⁺ and Eu³⁺ were observed from PL studies. The optimum doping concentration of Eu was found to be 7.5 mol% (x = 0.075). In this work, the lifetimes of Eu³⁺ and Eu²⁺ were considerably longer than those from some references. Under the excitation of different near ultraviolet (n-UV) longer wavelengths (λex = 360, 370, and 380 nm), the white light emission can be realized with the CIE chromaticity coordinates (0.3907, 0.3595), (0.3472, 0.3282), and (0.3504, 0.3062) for the phosphor LSO: 0.075Eu. The chromaticity coordinates of the phosphor were all located in the white region. Therefore, it is suggested that the explored LSO: 0.075Eu phosphor can be a good candidate for white light-emitting diodes (W-LEDs) application.     

Controllable synthesis of bifunctional material Ca2Ti2O6:Eu3+ and its comparative study on luminescence and photocatalytic properties with CaTiO3:Eu3+

Pure pyrochlore Ca₂Ti₂O₆, perovskite CaTiO₃, and their mixed crystalline phases with different proportions were controllably synthesized via a solvothermal method, followed by a subsequent calcination process. RIR (reference intensity ratio) data of Ca₂Ti₂O₆ were first obtained by X-ray diffraction (XRD), which can be used to quantitatively analyze the phase composition. When Eu³⁺ is doped into these calcium titanium oxides, they can be used as luminescent and photocatalytic materials. The structure, luminescence, and photocatalytic properties of pure pyrochlore Ca₂Ti₂O₆:Eu³⁺ and perovskite CaTiO₃:Eu³⁺ were comparatively studied in detail. The relative intensities of the excitation peaks and the emission peaks in Ca₂Ti₂O₆:Eu³⁺ and CaTiO₃:Eu³⁺ are different, which is attributed to the different symmetries of Eu³⁺ inhabiting the two kinds of lattices. In addition, although the luminescence intensity of CaTiO₃:3%Eu³⁺ is higher than that of Ca₂Ti₂O₆:3%Eu³⁺ under excitation at 394 nm, the luminescence intensity of Ca₂Ti₂O₆:3%Eu³⁺ is superior to that of CaTiO₃:3%Eu³⁺ under excitation at 464 nm and 533 nm. Photocatalytic experiments show that Ca₂Ti₂O₆:3%Eu³⁺ has better photocatalytic performance than CaTiO₃:3%Eu³⁺, which is mainly due to its smaller crystallite size, higher specific surface area and pyrochlore structure. In addition, biphase (Ca₂Ti₂O₆–CaTiO₃):3%Eu³⁺ has the best photocatalytic activity compared with the single phase Ca₂Ti₂O₆:3%Eu³⁺ and CaTiO₃:3%Eu³⁺, owing to the presence of heterojunctions that significantly reduced the band gap. It is anticipated that the discovery of this bifunctional Ca₂Ti₂O₆:Eu³⁺ would expand the application of rare earth-doped calcium titanium oxide materials.     

Luminescence and structure of Eu2+-doped Ba2CaMg2Si6O17

Eu²⁺-activated Ba₂CaMg₂Si₆O₁₇ phosphors were synthesized by conventional solid-state reaction. The phase formation was confirmed by X-ray powder diffraction measurement. The photoluminescence excitation and emission spectra were investigated. The phosphor presents blue-emitting luminescence. The crystallographic sites of Eu²⁺ ions in Ba₂CaMg₂Si₆O₁₇ host were discussed on the base of luminescence properties and the crystal structure. The lightly Eu²⁺-doped sample shows one luminescence center for the Eu²⁺ ions on Ba²⁺ sites, while there are two luminescence centers for the Eu²⁺ ions on both the Ba and Ca sites in heavily Eu²⁺-doped sample. The dependence of luminescence intensity on temperatures and the activation energy (ΔE) for the thermal quenching were reported. The phosphor shows an excellent thermal stability on temperature quenching because of the special layered structure of Ba²⁺ ions in the interlayer between SiO₄ layers.     

Synthesis,Crystal Structure,and Luminescence Properties of Y4Si2O7N2: Eu2+ Oxynitride Phosphors

Y₄Si₂O₇N₂: Eu²⁺ phosphor has been prepared by a pretreatment method. Reduction in Eu³⁺ ions into Eu²⁺ by the use of hydrogen iodide (HI) is verified by X‐ray absorption near‐edge structure (XANES) and electrode potential analysis. Y₄Si₂O₇N₂: Eu²⁺ phosphor has a broad emission band in the range of 400–500 nm. Furthermore, the effect of Zr doping on the structure and luminescence properties of Y₄Si₂O₇N₂: Eu²⁺ phosphor is researched. It found that the Zr doping leads to an emission blueshift, and improves the luminescence intensity and thermal quenching behavior of Y₄Si₂O₇N₂: Eu²⁺ phosphors. Prospectively, the pretreatment approach could be extended to develop other Eu²⁺‐doped compounds.