Experimental and theoretical studies on NIR luminescence of titanate-germanate glasses doped with Pr3+ and Tm3+ ions

Near-infrared (NIR) luminescence of Pr³⁺ and Tm³⁺ ions in titanate-germanate glasses has been studied for laser and fiber amplifier applications. The effect of the molar ratio GeO₂:TiO₂ (from 5:1 to 1:5) on spectroscopic properties of glass systems was studied by absorption, luminescence measurements, and theoretical calculations using the Judd–Ofelt theory. It was found that independent of the TiO₂ concentration, intense NIR emissions at 1.5 and 1.8 μm were observed for glasses doped with Pr³⁺ and Tm³⁺ ions, respectively. Moreover, several spectroscopic and NIR laser parameters for Pr³⁺ and Tm³⁺ ions, such as emission bandwidth, stimulated emission cross-section, quantum efficiency, gain bandwidth, and figure of merit, were determined. The results were discussed in detail and compared to the different laser glasses. Systematic investigations indicate that Pr³⁺-doped system with GeO₂:TiO₂ = 2:1 and Tm³⁺-doped glass with GeO₂:TiO₂ = 1:2 present profit laser parameters and could be successfully applied to NIR lasers and broadband optical amplifiers.     

Two micrometer fluorescence emission and energy transfer in Yb3+/Ho3+ co-doped lead silicate glass

Enhanced 2.0 μm and visible up-conversion emissions from Ho³⁺ via Yb³⁺ sensitization in lead silicate glasses have been obtained under the excitation of 980-nm laser diode. The possible energy transfer mechanism has been analyzed based on the photoemission spectroscopy and lifetime measurement. The lifetime of Ho³⁺: ⁵I₇ laser upper level has also been measured. Based on the absorption spectra, Judd–Ofelt parameters, spontaneous emission probability, the absorption, emission cross sections, and gain coefficients have been calculated and analyzed. The results indicate that the Yb³⁺/Ho³⁺ co-doped lead silicate glass has potential application in mid-infrared wavelengths.     

Dazzling cool white light emission from Ce3+/Sm3+ activated LBZ glasses for W-LED applications

We synthesized a batch of co-doped (Ce³⁺+Sm³⁺): LBZ glass specimens by melt quenching process and their structural and radiation properties were studied by employing XRD, FE-SEM, optical absorption, photoluminescence and lifetime measurements. UV–Vis–NIR absorption studies of the co-doped (Ce³⁺+Sm³⁺): LBZ glassy matrix displays pertinent bands of both Ce³⁺ and Sm³⁺ ions. Individually doped Sm³⁺: LBZ glass exhibit bright orange emission at 603?nm (⁴G_5/2 → ⁶H_7/2) under the excitation of 403?nm. Nevertheless, the luminescence intensities pertaining to Sm³⁺ were extraordinarily increased by co-doping with Ce³⁺ ions to Sm³⁺: LBZ glassy matrices because of energy transfer from Ce³⁺ to Sm³⁺. The fluorescence spectra of co-doped (Ce³⁺+Sm³⁺): LBZ exhibits characteristic emission bands of Ce³⁺ (441?nm, blue) and Sm³⁺ (603?nm, reddish orange) under the excitation of 362?nm. Decay curves of Ce³⁺ and Sm³⁺ ions in co-doped glass has been fitted to double exponential nature. The decreasing lifetime of donor ion and rising lifetime of acceptor ion in double doped glass could support the energy transfer from Ce³⁺ to Sm³⁺ ions in the host matrix. The CIE coordinates and CCT values were calculated for all the obtained co-doped glassy samples from their luminescence spectra. By adding Ce³⁺ ions to individually doped Sm³⁺: LBZ glass matrix, the emitting color changes from reddish orange to white light which resembles the energy transfer from Ce³⁺ to Sm³⁺ ions. These studies, perhaps implied that attained co-doped (Ce³⁺+Sm³⁺): LBZ glassy samples are potential materials for white lighting appliances.     

Near white light emission of Ce3+‐, Ho3+‐, and Sm3+‐doped oxyfluoride silicate glasses

The Ce³⁺‐, Ho³⁺‐, and Sm³⁺‐ single and co‐doped oxyfluoride silicate glasses for light emitting diodes are studied. These glasses were prepared by melt quenching method and their optical and structural properties were investigated by absorption spectra, photoluminescence spectra, Commission International de I'Eclairage chromaticity coordinates, X‐ray diffraction, and Fourier transform infrared spectra. It is found that the introduction of Al₂O₃ in glass composition can improve the emissions of Ho³⁺ and Sm³⁺. While the presence of B₂O₃ has the adverse effect and can suppress the emissions of Ho³⁺ and Sm³⁺. With substituting Na₂O for CaO in the glass compositions, CaF₂ crystals can be formed during the melt quenching process. We find the formation of CaF₂ crystals can change the emission behavior of Ho³⁺ and Sm³⁺ ions. White light emissions can be achieved in the glasses and the luminescence colors can be tuned by varying the concentrations of the doped rare‐earth ions and the composition of glass matrix. The Ce³⁺‐, Ho³⁺‐, and Sm³⁺‐doped oxyfluoride silicate glasses presented here demonstrate promising applications in the fields of light emitting diodes.     

Trap level analysis of Ce3+ and Sm3+ in Li6Y(BO3)3

The polycrystalline compounds of Li₆Y(BO₃)₃: Ce³⁺ and Sm³⁺ co-doped polycrystalline samples were prepared by using standard solid state reaction method. The energy levels of the doped lanthanide ions (Ce³⁺ and Sm³⁺) in the borate host materials were investigated by Thermoluminescence (TL) glow peak analysis. The co-doped samples, exhibits the TL peak at higher temperature region around 511?K whereas the Ce³⁺ individually doped sample has peak around 433?K. The X-ray excited emission spectra were carried out for all the prepared samples and found the characteristic emission bands. The trap depths (E) were calculated by using several standard methods, namely peak shape method or chen's (PS), variable heating rate (VHR), initial rise (IR) and computerized glow curve deconvolution (CGCD). The mean activation energy of the co-doped samples found to be 1.21 (0.07±) eV and the frequency factor around 1.38?×?10¹¹ Sec^?1. The calculated trap depths and the predicted energy level values were compared and found in good agreement. This primarily results suggest that the energy level scheme can help in the development of new TL materials suitable in dosimetry.     

Photoluminescence of Tb3+/Sm3+ ions co-activated in SrO - Na2O - WO3 - tellurite glasses for multicolor laser applications

A novel series of Tb³⁺, Sm³⁺ single doped and Tb³⁺/Sm³⁺ co-incorporated tungsten tellurite glasses were synthesized by melt quenching technique and corresponding structural as well as luminescence features of the prepared glasses have been reported here. Spectral overlapping between the luminescence spectra of Tb³⁺ ions and the excitation spectra of Sm³⁺ ions manifests that the energy transfer process takes place from Tb³⁺ ions to Sm³⁺ ions. By using the dual excitations at 377 and 484 nm, the titled co-doped glasses emit green light of wavelength 542 nm along with reddish – orange colour light at 599 nm. In addition to this, there is no possibility of reverse energy transfer which is validated with the help of excitation at 403 nm (Sm³⁺ ions) as major evidence. The lifetimes of all co-doped glasses decline with increasing Tb³⁺ doping level in the ligand matrices, indicating the energy migration process takes place from Tb³⁺→ Sm³⁺. The chromaticity coordinates of all synthesized co-doped glasses lie in yellowish-orange region of CIE1931 diagram and it shifts to deep yellow region when Tb³⁺ ion concentration varies. Our findings propose that the titled glasses can be used as visible laser materials for multicolor laser applications.     

Er3+/Yb3+ co-doped bioactive glasses with up-conversion luminescence prepared by containerless processing

Er³⁺/Yb³⁺ co-doped bioactive glasses were prepared via containerless processing in an aerodynamic levitation furnace. The as-prepared glasses were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) equipped with energy dispersive X-Ray spectroscopy (EDX). The up-conversion luminescence of as-prepared glasses was measured using an Omni- 3007 spectrometer. Furthermore, the in vitro bioactivity was evaluated by soaking the materials in simulated body fluid, and the biocompatibility was evaluated in MC3T3-E1 cell culture.The results show that containerless processing is a unique method to prepare homogeneous rare earth doped bioactive glasses. The obtained Er³⁺/Yb³⁺ co-doped glasses show green and red up-conversion luminescence at the excitation of 980 nm laser. The XRD analysis confirmed that calcium silicate powders, as starting materials, were completely transformed from the original multi-crystalline phase (CS-P) into the amorphous-glassy phase (CS-G, EYS, LCS) via containerless processing. The SEM observation combined with EDX and FTIR analyses showed that the as-prepared glasses were bioactive. The cell proliferation assay also revealed that the as-prepared glasses were biocompatible and nontoxic to MC3T3-E1 cells. This study suggests that the luminescent bioactive glasses prepared by containerless processing could be used for studying biodegradation of bone implantation materials.     

Luminescence properties and energy transfer of GdAl3(BO3)4:Ce3+, Tb3+ phosphor

Ce³⁺ and Tb³⁺ singly doped and co-doped GdAl₃(BO₃)₄ phosphors were synthesized by solid state reaction. The crystal structure, the luminescent properties, the lifetimes and the temperature-dependent luminescence characteristic of the phosphors were investigated. Through an effective energy transfer, the emission spectra of GdAl₃(BO₃)₄:Ce³⁺, Tb³⁺ phosphor contains both a broad band in the range of 330–400 nm originated from Ce³⁺ ions and a series of sharp peaks at 484, 541, 583, and 623 nm due to Tb³⁺ ions. The energy transfer from Ce³⁺ to Tb³⁺ in GdAl₃(BO₃)₄ host is demonstrated to be phonon assisted nonradiative energy transfer via a dipole–dipole interaction.     

Ce3+‐ and Dy3+‐Doped Oxyfluoride Borosilicate Glasses with Near White Luminescence

A series of Ce³⁺/Dy³⁺‐doped oxyfluoride borosilicate glasses prepared by melt‐quenching method are investigated for light‐emitting diodes applications. These glasses are studied via X‐ray diffraction (XRD), optical absorption, photoluminescence (PL), color coordinate, and Fourier transform infrared (FT‐IR) spectra. We find that the absorption and emission bands of Ce³⁺ ions move to the longer wavelengths with increasing Ce³⁺ concentrations and decreasing B₂O₃ and Al₂O₃ contents in the glass compositions. We also discover the emission behavior of Ce³⁺ ions is dependent on the excitation wavelengths. The glass structure variations with changing glass compositions are examined using the FT‐IR spectra. The influence of glass network structure on the luminescence of Ce³⁺/Dy³⁺ codoped glasses is studied. Furthermore, the near‐ideal white light emission (color coordinate x = 0.32, y = 0.32) from the Ce³⁺/Dy³⁺ codoped glasses excited at 350 nm UV light is realized.     

Photoluminescence and energy transfer of Lu3Al5O12:Ce3+, Pr3+ phosphors

Ce³⁺ and Pr³⁺ co?doped Lu₃Al₅O₁₂ phosphors were synthesized by the sol–gel process, and their crystal structure, photoluminescence (PL) properties, and energy transfer (ET) from the Ce³⁺ to Pr³⁺ were studied. The Lu_2.94?yAl₅O₁₂:0.06Ce³⁺, yPr³⁺ phosphors (0.002 ≤ y ≤ 0.008) showed the green?yellow emission from the ²D_3/2 → ²F_{5/2, 7/2} transition of Ce³⁺ and the red emission at 610 and 637 nm, which were caused by the ¹D₂→³H₄ and ³P₀→³H₅ transitions of Pr³⁺, respectively. The optimal concentration of Pr³⁺ for efficient ET was found to be x = 0.006. The electric quadrupole?quadrupole interaction was responsible for the concentration quenching in the Lu_2.94?yAl₅O₁₂:0.06Ce³⁺, yPr³⁺ phosphors, based on Dexter's theory. The incorporation of Pr³⁺ for Lu³⁺ enhanced the red PL intensity in the Lu_2.94Al₅O₁₂:0.06Ce³⁺ phosphor.     

Laser excitation-activated self-propagating sintering of NaYbF4:Pr3+/Gd3+ white light microcrystal phosphors

We demonstrate that self-propagating sintering reaction could be activated and dramatically enhanced by laser excitation of ion dopants in the solid-state reactants. Near-resonant laser absorption and subsequent nonradiative decays make the solid-state reactants be sintered efficiently while ionic excitations catalyze self-propagating solid-state reactions. As a prototype demo, we synthesized white light upconversion phosphors NaYbF₄:Pr³⁺/Gd³⁺. A continuous-wave laser at 980 nm was used to populate Yb³⁺ ions in YbF₃ to excited level, which react with NaF to preform NaYbF₄ nuclei. The preformed nuclei enhanced laser excitation and energy transfer to those ions that could not be directly excited by the pump laser and thus enabled self-propagating solid-state sintering synthesis of NaYbF₄ microcrystals at quite low laser powers. Laser excitation of Yb³⁺ ions could also benefit facile rare-earth ion doping through activated self-propagating reactions. Gd³⁺ and Pr³⁺ ions were doped in NaYbF₄ by simply adding Gd³⁺ and Pr³⁺ ionic oxides or fluorides in the raw materials. In addition, Gd³⁺ ions doping in F⁻ anions ambient could transform the NaYbF₄ microcrystal phase from cubic to hexagonal and tune upconversion photoluminescence. This synthetic method can be widely applied to synthesize many other solid-state compounds, perovskite solar cells, photocatalysts, solid oxide fuel cells, and so forth.     

Microstructure and optical properties of Pr3+-doped hafnium silicate films

In this study, we report on the evolution of the microstructure and photoluminescence properties of Pr³⁺-doped hafnium silicate thin films as a function of annealing temperature (T_A). The composition and microstructure of the films were characterized by means of Rutherford backscattering spectrometry, spectroscopic ellipsometry, Fourier transform infrared absorption, and X-ray diffraction, while the emission properties have been studied by means of photoluminescence (PL) and PL excitation (PLE) spectroscopies. It was observed that a post-annealing treatment favors the phase separation in hafnium silicate matrix being more evident at 950°C. The HfO₂ phase demonstrates a pronounced crystallization in tetragonal phase upon 950°C annealing. Pr³⁺ emission appeared at T_A = 950°C, and the highest efficiency of Pr³⁺ ion emission was detected upon a thermal treatment at 1,000°C. Analysis of the PLE spectra reveals an efficient energy transfer from matrix defects towards Pr³⁺ ions. It is considered that oxygen vacancies act as effective Pr³⁺ sensitizer. Finally, a PL study of undoped HfO₂ and HfSiO_x matrices is performed to evidence the energy transfer.     

Intense 2.7 µm emission of Er3+/Pr3+ doped Ga5Ge20Sb10S65 chalcogenide glass

There are numerous vital usages for mid-infrared (MIR) lasers in satellite communication, biomedicine, military, remote sensing, and environmental monitoring. In this work, a progression of Er³⁺ ions doped, Er³⁺/Pr³⁺ ions co-doped Ga₅Ge₂₀Sb₁₀S₆₅ glasses were prepared, and their physical performances and structural characteristics were examined. To understand the non-phonon-assisted energy transfer mechanism, we recorded the up-conversion and infrared fluorescence emission spectra by pumping with a commercial 980 nm LD. Then the 2.7 µm strong fluorescence signal intensity can be obtained when the doped concentration of Pr³⁺ is proper. After the doping of Pr³⁺, fluorescence lifetime results revealed that the lifetimes of the Er³⁺:⁴I_13/2 level fell dramatically from 7.33 to 1.90 ms, which experienced a much more significant decrease in lifetimes than the Er³⁺:⁴I_11/2 level. The MIR fluorescence performances were assessed by the determined J–O parameters and relative emission cross sections. Additionally, the generally huge emission cross sections and the small pump energy show that it is possible to obtain population inversion with relatively small pump energy; thus the Er³⁺/Pr³⁺ glasses have great potential to be 2.7 µm laser materials.     

Detailed optical analysis of Dy3+ and Pr3+ co-doped alumino-borate glasses for visible lighting applications

A new glass series with nominal molar composition of 60B₂O₃ + 30NaF + 10Al₂O₃ co-doped with Dy³⁺ and Pr³⁺, synthesized by melt quench was reported. The influence of Rare Earth (RE) ratio variation on prepared glasses was investigated by using Fourier Transform Infra-Red spectroscopy, UV–Vis–NIR absorption spectroscopy, Photoluminescence, Decay curves and Density measurements. Their X-Ray Diffraction and FTIR spectra revealed the glassy nature and confirmed that AlO₆, AlO₄, BO₃ and BO₄ units are the main structural units of that matrix. A non-linear variation following the same trend for tetragonal borate units (N₄), Band gap, non-linear optical properties, Density, Molar Volume etc. was observed. Different optical parameters were obtained by UV–Vis–NIR spectroscopy. The Bonding parameter obtained from Nephelauxetic study indicated ionic nature of Dy³⁺ and covalent nature of Pr³⁺ ions. Photoluminescence excitation and emission spectra were recorded under variety of excitation wavelengths and corresponding color parameters were calculated using 1931 CIE standards. A detailed yellow to blue ratio analysis was reported as a function of RE ion concentration and excitation wavelengths. Composition DPNAB(x = 0.7) displayed the best performance with CIE coordinates (0.33, 0.37). Existence of Energy transfer from Dy³⁺ and Pr³⁺ was evidenced by the spectral overlap diagram and lifetime values obtained from fitting of Decay curves. From the obtained results, prepared glasses can be suggested for solid-state lighting devices like WLEDs and display devices.     

Investigation of Pr3+ Near-Infrared Emission in Plasmonic and Dichroic Copper Nanocomposite Glasses

Melt-quenched Pr³⁺-doped phosphate glass containing Cu⁺ and Sn²⁺ as redox couple to induce Cu nanoparticle (NP) precipitation was subjected to heat treatment to develop nanocomposite glasses with plasmonic and dichroic character. The purpose was to examine the impact of Cu NPs producing dichroism on the near-infrared (NIR) emission from Pr³⁺. The parent and isothermally heat-treated glasses (520?°C: 20, 40, 60?min) were characterized by differential scanning calorimetry, Fourier transform-infrared spectroscopy, optical extinction, and photoluminescence spectroscopy with decay dynamics. From the samples, the heat-treated for 40 and 60?min showed broad plasmonic bands alongside dichroism wherein the glasses scatter red light but transmit blue. The Pr³⁺ NIR emission encompassing ¹D₂ → ³F₄, ³F₃,¹G₄ transitions was evaluated under 445 and 590?nm excitation. An increased emission was not exhibited, whereas a quenching effect became evident for samples heat-treated for 40 and 60?min. Different interactions involving Pr³⁺ ions and Cu NPs are discussed.

     

Effects of Gd3+ substitution on the structure,photoluminescence, scintillation,and thermometric features of Pr3+:Lu2Zr2O7 phosphors

In this study, it is shown how the photoluminescence, scintillation, and optical thermometric properties are managed via the introduction of Gd³⁺ ions into Pr³⁺:Lu₂Zr₂O₇. Raman spectra validate that partial replacement of Lu³⁺ with Gd³⁺ can promote the phase transition of Lu₂Zr₂O₇ host from the defective fluorite structure to the ordered pyrochlore one. Upon 289 nm excitation, all the samples emit the 483 (³P₀ → ³H₄), 581 (¹D₂ → ³H₄), 611 (³P₀ → ³H₆), 636 (³P₀ → ³F₂), and 714 nm (³P₀ → ³F₄) emissions from Pr³⁺ ions, which are enhanced with the addition of Gd³⁺ ions due to the modification of crystal structure. Dissimilarly, the X-ray excited luminescence spectra consist of a strong emission located at 314 nm from Gd³⁺ ions (⁶P_7/2 → ⁸S_7/2), together with the typical emissions from Pr³⁺ ions, which exhibit different dependences on the Gd³⁺ concentration. When the luminescence intensity ratio between the ³P₀ → ³H₆ (611 nm) and ¹D₂ → ³H₄ (581 nm) transitions is selected for temperature sensing, Pr³⁺:(Lu_0.75Gd_0.25)₂Zr₂O₇ shows the optimal relative sensing sensitivity of 0.78% K⁻¹ at 303 K, which is higher than that of the Gd³⁺-free sample. Therefore, the developed Pr³⁺:(Lu, Gd)₂Zr₂O₇ phosphors have the applicative potential for optical thermometry, X-ray detection, and photodynamic therapy.     

Visible emission and energy transfer in Tb3+/Dy3+ co-doped phosphate glasses

In this work, we systematically study the spectroscopic properties of Tb³⁺/Dy³⁺ co-doped phosphate glasses in the visible spectral region and explore the sensitization role of Dy³⁺ in the enhancement of visible fluorescence of Tb³⁺ ions. Judd-Ofelt parameters Ω₂ and Ω₄/Ω₆ of the phosphate glass as host for Tb³⁺ are calculated as 21.60 × 10^-20 cm² and 0.73, respectively, based on the measured spectral absorption. Multiple energy transfer (ET) routes from Dy³⁺ to Tb³⁺ and their efficiencies are characterized, and the enhanced fluorescence properties of Tb³⁺ are investigated, including the emission spectral strength and the spontaneous emission lifetime as functions of Dy³⁺ doping concentration. The efficient nonradiative ET processes between Dy³⁺ and Tb³⁺ allow a moderate concentration level of Tb³⁺ to achieve favorably stronger spectral absorption at blue and ultraviolet wavelengths. Tb³⁺/Dy³⁺ co-doped phosphate glass shows promising potential for phosphors and lasing operation at visible wavelengths.     

High-performance inductive couplers based on novel Ce3+ and Co2+ ions co-doped Ni-Zn ferrites

High-performance inductive couplers require Ni-Zn ferrites of high saturation magnetization, Curie temperature, permeability and application frequency. However, for inductive couplers some of these properties run against each other in one ferrite. To balance these requirements, in this work, novel Ni-Zn ferrite ceramics co-doped by Ce³⁺ and Co²⁺ ions with chemical formula Ni_0.4Zn_0.5Co_0.1Ce_xFe_2-xO₄ (x = 0–0.06) were designed and fabricated by a molten salt method. For the acquired ferrites, both Ce³⁺ and Co²⁺ ions could come into the lattices. The initially doped Co²⁺ ions would cause a slightly decreased grain size and dramatically reduced the specimen densification, but the further added Ce³⁺ ions could effectively inhibit the density reduction, while the grain size continues to dwindle. The additional Ce³⁺ ions would generate a foreign CeO₂ phase in the acquired specimens. The sole doping of Co²⁺ ions would aggrandize the saturation magnetization of ferrites, but the introduction of Ce³⁺ ions would cause its decrease. However, with an appropriate doping level, the Ce³⁺ and Co²⁺ ions co-doped ferrites could preserve a relatively high saturation magnetization, while the Curie temperature and cut-off frequency of the ferrites are dramatically augmented, although the permeability would be somewhat reduced. The as-acquired ferrites were simulated to apply in inductive couplers, revealing that the devices manufactured by the Ni_0.4Zn_0.5Co_0.1Ce_xFe_2-xO₄ ferrites had significantly high maximum operating frequency, compared with that of the one manufactured by pure Ni_0.5Zn_0.5Fe₂O₄ ferrite.     

Gd3+ doping induced microstructural evolution and enhanced visible luminescence of Pr3+ activated calcium fluoride transparent ceramics

Transparent Pr³⁺ doped Ca_1-xGd_xF_2+x (x = 0, 0.01, 0.03, 0.06, 0.10, 0.15) polycrystalline ceramics with fine-grained microstructures were prepared by the hot-pressing method. The dependence of microstructure, optical transmittance, luminescence performances and mechanical properties on the Gd³⁺ concentrations for Pr³⁺:Ca_1-xGd_xF_2+x transparent ceramics were investigated. The Gd³⁺ ions show positive effects on the microhardness of Pr³⁺:Ca_1-xGd_xF_2+x transparent ceramics as a result of the decrease in the grain sizes. Excited by the Xenon lamp of 444 nm, typical visible emissions located at 484 nm, 598 nm and 642 nm were observed. Furthermore, the incorporation of Gd³⁺ ions can greatly enhance the photoluminescence performance owing to the improvement in the concentration quenching effect. The quenching concentration of Pr³⁺ ions in CaF₂ transparent ceramics increased to 1 at.% as a result of the positive effect of Gd³⁺ codoping. The energy transfer mechanism of Pr³⁺ in the Pr³⁺:Ca_1-xGd_xF_2+x transparent ceramics has been investigated and discussed.     

Effect of the Ce3+ concentration on laser-sintered YAG ceramics for white LEDs applications

This paper describes the laser sintering and luminescence properties of Y₃Al₅O₁₂ (YAG) phosphors doped with different concentrations of Ce³⁺ and synthesized using the polymeric precursor method. The ceramics were sintered by a new laser sintering technique in which a CO₂ laser is employed as the heating source. The resultant ceramics exhibited a homogeneous microstructure with narrow grain size distribution and high relative density. The introduction of Ce³⁺ ions led to luminescence quenching at a concentration above 0.5 mol% and a redshift of the emission spectrum band with increasing cerium concentration. The excitation spectrum showed two characteristic bands centered at 340 nm and 460 nm and a relative change in their intensity by change the Ce³⁺ concentration. The presence of a single valence (Ce³⁺) of cerium was determined by X-ray absorption near edge structure measurements.