Luminescence and Energy Transfer Properties of Color-Tunable Dy3+, Eu3+ co-Activated NaGdSiO4 Phosphor for WLED with Great Thermo-Stability.

A series of NaGd1-x-ySiO4: y Dy3+-x Eu3+ phosphors were synthesized by a high-temperature solid-phase method. The optimal doping ion concentration of Dy3+ ions for this phosphor was determined to be 1 % from the emission spectra. The energy transfer between Dy3+ and Eu3+ ions at 351 nm was investigated by photoluminescence spectra and fluorescence decay curves. At the excitation wavelengths of 275 nm, 351 nm, 366 nm, and 394 nm, a change from yellow to white to red light can be realized by adjusting the doping concentration of Eu/Dy ions. Particularly, by testing the temperature-dependent fluorescence spectrum of the phosphor, it can be found that the luminous intensity of the phosphor is as high as 96 % when 394 nm excitation is employed at 413 K. It was the maximum at this temperature comparing with other phosphors as far as we know. The color coordinate values show that the NaGd1-x-ySiO4:×Dy3+-y Eu3+ phosphors are very close to the white light color coordinates (x=0.33, y=0.33) under 351 nm excitation. Meanwhile, the correlated color temperature is between 5062-7104 K. These results indicate that this phosphor is a promising candidate for high-quality WLED.

Optimizing the White Light Emission of Pr3+ Activated SrCeO3 Perovskite by Controlling the Excitation Wavelength for High CRI wLED Applications.

The current research illustrates excitation energy-triggered photoluminescent characteristics of Pr3+ions in SrCeO3 providing a practical approach for developing high CRI wLED and its applications. SrCeO3: xPr3+ (x = 0, 0.005, 0.01, 0.02, 0.03 wt) perovskites synthesized by fuel excess gel combustion method generate high CRI (~98) for wLED applications. Crystalline phosphors with orthorhombic structures having space group Pnma were confirmed by XRD. The unit cell volume expansion occurred with an increase in Pr3+ concentration was verified through the Rietveld refinement technique. Surface morphology, particle distribution, and size were observed via FE-SEM imaging, and detected a well-defined regular distorted spherical structure with average grain size 0.826 µm for Pr3+ doped SrCeO3. Elemental mapping and EDS analysis identified the uniform distribution and elemental purity of SrCeO3: 0.01 Pr3+. Further, the molecular vibrations and modes were analyzed from the Raman spectrum. Moreover, the average particle size assessed via TEM analysis was found to be ~83.2 nm, consistent with XRD analysis. UV-visible absorption spectra for optical energy-band gap analysis showed a decrease in band gap energy with an increase in Pr3+ concentration, realizing an effective energy transfer from Ce4+ to Pr3+. PL measurements showed a huge variety of emission transitions, corresponding to excitations 290 nm, 321 nm, 373 nm, and 449 nm. The critical dopant concentration instigated by concentration quenching was 1 wt% Pr3+, ascribed to dipole-dipole interaction. The fluorescence lifetime of the optimal sample was 4.835 µs. Commission International de I'Eclairage (CIE) diagram exposes the white light emanation of SrCeO3: Pr3+. Among which white light with high CRI (~98) and comparably low CCT (~6311 K) was obtained for SrCeO3: 0.01 Pr3+ at 373 nm excitation. The obtained results recommend that SrCeO3: Pr3+ perovskite as an efficient white phosphor for fabricating high-performance wLEDs.

Novel White Phosphor Bi3+ co-doped SrCeO3: 2 wt% Sm3+ Synthesized via Fuel Excess Gel Combustion Synthesis for wLED Applications.

Co-doping strategy is done if the emission from the activator is relatively low with existing excitation energy. Thus, to enrich the emission from an activator, the sensitizer like Bi3+ is co-doped onto the host and this intermediator transfers its emission energy to the activator. Prior to the study, no investigations had been conducted, marking the foundational exploration of the sensitizer effect within the rare earth-doped SrCeO3 matrix aimed at enhancing luminescence properties. The current study focuses on the innovation of single-phase robust white phosphors, SrCeO3: 2wt% Sm3+: xBi3+ (x = 0 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%) to coat near UV LED chips for high CRI wLED applications. The novel perovskites were synthesized using a low-temperature fuel excess gel combustion method, utilizing citric acid as the fuel and ammonium nitrate as an extra oxidizer. Upon co-doping SrCeO3: 2wt% Sm3+ with bismuth, the impact of changing sensitizer concentration on both the development of crystalline phases, morphology, elemental composition, band gap energy, and the luminescent properties of ceramic powders were explored through X-ray diffraction, FE-SEM, Energy dispersive spectra, UV-visible absorption spectra, and photoluminescence characterization methods. The experimental results revealed the orthorhombic single-phase formation of SrCeO3: 2wt% Sm3+: xBi3+perovskites yielding high crystallinity and luminescence maximum at critical sensitizer concentration 1 wt% Bi3+. Also, the bright white light emission of all the perovskites was confirmed using the CIE color diagram. Thus, nano-perovskite SrCe0.97Sm0.02O3: 1wt% Bi3+ acts as an inevitable direct phosphor coating the near UV chip in LEDs, which can be a great revolution in energy savings applications.

Synthesis and Characterizations of Novel bi-ligand TbEu(cpioa)phen Phosphors with High Quantum Efficiency for WLED Applications.

The hydrothermal method was employed to synthesize a novel bi-ligands LnMOF: Ln(cpioa)phen. The secondary ligand 1, 10-phen serves as a bridging agent to further facilitate energy transfer between Ln ions and the primary ligand H3cpioa. A comparison between Ln(cpioa) MOFs (Ln: Tb3+, Eu3+) and Ln(cpioa)phen MOFs (Ln: Tb3+, Eu3+) reveals that addition of the secondary ligand significantly improves the emission intensity by as high as almost 34 times. After detailed structural study, it is found that different Ln ions have the similar coordination in the Ln(cpioa)phen MOF. In addition, the chromaticity of Ln(cpioa)phen MOFs can be easily tuned by the amounts of doping Ln ions. La0.974Tb0.0255Eu0.0005(cpioa)phen MOF has a white emission with a CIE coordinate of (0.323, 0.343). Characterizations of corresponding LED devices show that device based on Ln(cpioa)phen MOF has better photoluminescence performances, which indicates that Ln(cpioa)phen MOF has great potential of for WLED applications.

Combustion Synthesis and Photoluminescence Properties of Novel Bi2Al4O9:Eu3+ Phosphor for n-UV w-LEDs.

The combustion procedure was used to synthesize Bi2Al4O9:Eu3+ phosphors. The XRD and photoluminescence properties are investigations. The XRD patterns consist of an orthorhombic crystal structure. At 395 nm, the maximum excitation intensity was obtained. Following 395 nm excitation, two different emission peaks at 593 and 615 nm were observed. Concentration quenching occurred at 0.5 mol % Eu3+ ions. The CIE coordinates for the Bi2Al4O9 phosphor with Eu3+ ion doped are 615 nm (x = 0.680, y = 0.319) falling in the red region. According to the photoluminescence results, Bi2Al4O9:Eu3+ phosphors might be useful in the fields of near UV-excited w-LEDs.

Studies on a novel SrZr2 CaLa2 O8 :Eu3+ phosphor for lighting applications emitting direct white light.

Direct white light emitting phosphors play a significant role in the display industry due to their ability to improve the quality, efficiency, and versatility of lighting sources used in most of the displays. The currently investigated phosphor SrZr2 CaLa2 O8 :Eu3+ was prepared by a conventional solid-state reaction method. It has been observed that the stoichiometric ratio of all precursors plays an important role in determining the characteristics of the final phosphor. From X-ray diffraction (XRD) analysis, the phosphor was observed to have a hexagonal phase and a crystal size of ~28 nm. Scanning electron microscopy (SEM) observations revealed a cluster of rod-like structures with an average diameter of ~0.2 µm. The excitation peak maximum observed at 280 nm is due to charge transfer between Eu3+ -O2- ions. The energy transitions 7 F0 → 5 L6 and 7 F0 → 5 D2 are responsible for the appearance of other excitation peaks at ultraviolet (UV) (395 nm), blue (~467 nm), green (~540 nm), orange (~590 nm), and red (~627 nm) attributed to 5 D0 → 7 FJ (J = 0-4) transitions of europium ion (Eu3+ ). The Commercial International de I'Eclairage (CIE) chromaticity coordinates were estimated to be (0.37, 0.0.33) and (0.67, 0.33) for the emissions corresponding to 395 and 590 nm, respectively. The characteristic emissions of Eu3+ ions allow this novel phosphor to be used to generate direct white light in light-emitting diodes (LEDs), which is otherwise difficult to achieve in single-component systems.

Tunable warm white light emission and energy transfer of Dy3+ co-doped Sr2 LaZrO5.5 :Eu3+ phosphors.

Eu3+ ,Dy3+ co-doped Sr2 LaZrO5.5 -based phosphors were prepared through a sol-gel method. Through characterization, it was found that the Sr2 LaZrO5.5 -based fluorescent powder co-doped with Eu3+ and Dy3+ had a cubic structure. At an excitation wavelength of 290 nm, the substrate Sr2 LaZrO5.5 exhibited strong blue emission at 468 nm, and the Sr2 LaZrO5.5 :18%Eu3+ phosphor exhibited a strong red emission peak at 612 nm. When the doping amount of Dy3+ was 5, 8, 12, 15, or 18%, the Sr2 LaZrO5.5 :18%Eu3+ phosphor changed from an orange-red light, to a warm white light, and to a cold white light. According to the emission spectra, the emission intensities of the substrates Sr2 LaZrO5.5 and Sr2 LaZrO5.5 :Eu3+ decreased with increasing Dy3+ concentration, confirming the energy transfer between the host Sr2 LaZrO5.5 -Eu3+ ,Dy3+ , and resulting in a lower CCT value, with significantly improved white light emission.

Rubidium ions doping to improve the photoluminescence properties of Mn doped CsPbCl3perovskite quantum dots.

All-inorganic cesium lead halide CsPbX3(X = Cl, Br, I) perovskite quantum dots (PQDs) have shown promising potential in current Mini/Micro-LED display applications due to their excellent photoluminescence performance. However, lead ions in PQDs are easily to leak owing to the unstable structure of PQDs, which hinders their commercial applications. Herein, we adopt Rb+ions co-doping strategy to regulate the doping characteristics of Mn2+ions in CsPbCl3PQDs. The synthesized CsPbCl3:(Rb+, Mn2+) PQDs possess enhanced photoluminescence quantum yield of 71.1% due to the reduction of intrinsic defect states and Mn-Mn or Mn-traps in co-doped PQDs. Moreover, the white light emission of CsPb(Cl/Br)3:(Rb+, Mn2+) PQDs is achieved by anion exchange reaction and the constructed WLED exhibits the CIE coordinate of (0.33, 0.29) and the correlated color temperature of 5497 K. Benefiting from the substitution strategy, these doped CsPbX3PQDs can be widely used as fluorescence conversion materials for the construction of Mini/Micro-LED.

Photoluminescence characteristics of novel Sm3+ ions-doped La1.4 Al22.6 O36 phosphor for n-UV w-LED.

The combustion procedure was used to synthesize La1.4 Al22.6 O36 :Sm3+ phosphors. The X-ray diffraction (XRD) patterns and morphological and photoluminescence properties were investigated. The XRD patterns consisted of a hexagonal crystal structure. At 405 nm, the maximum excitation intensity was obtained. Following 405 nm excitation, three different emission peaks at 573, 604, and 651 nm were seen. Concentration quenching occurred at 1.5 mol% Sm3+ ions. The Commission Internationale de l'éclairage coordinates for the La1.4 Al22.6 O36 phosphor with Sm3+ doping were 604 nm (x = 0.644, y = 0.355) falling in the red region. The findings implied that the prepared phosphor may be used to develop w-light-emitting diodes.

Thermally stable Sm3+ -doped alkali zinc alumino borosilicate (AZABS) glass for warm white light generation and w-LED applications.

Samarium ion (Sm3+ )-doped alkali zinc alumino borosilicate (AZABS) glass was synthesized via quick melt quench technique. Various spectroscopic studies like optical absorption, photoluminescence (PL) emission, PL excitation, temperature-dependent PL and PL decay kinetics were performed on the as prepared glass system. Under 402 nm excitation, three sharp bands at wavelengths 563, 599 and 645 nm corresponding to transitions 4 G5/2 → 6 H5/2 , 6 H7/2 and 6 H9/2 , respectively, can be seen in the PL emission spectra. The 0.25 mol% Sm3+ glass has the highest intensity for these emissions. The lanthanide interaction in the glass matrix is dipole-dipole in nature as was proven from Dexter's analysis. The direct bandgap of 0.25 mol% Sm3+ -doped AZABS glass was calculated to be 2.88 eV. The lifetimes of the as prepared glass range from 1.93 ms for the lowest concentration of Sm3+ to 0.75 ms for the highest. From temperature dependent PL studies, the activation energy for 0.25 mol% Sm3+ -doped AZABS glass was found to be 0.19 eV which shows high thermal stability of this glass. We propose to utilize these Sm3+ -doped AZABS glasses for white-light emitting diodes (w-LEDs) and solid-state lighting (SSL) applications.

Luminescent Properties and Charge Compensator Effects of SrMo0.5W0.5O4:Eu3+ for White Light LEDs.

The high-temperature solid-phase approach was used to synthesize Eu3+-doped SrMo0.5W0.5O4 phosphors, whose morphological structure and luminescence properties were then characterized by XRD, SEM, FT-IR, excitation spectra, emission spectra, and fluorescence decay curves. The results reveal that the best phosphor synthesis temperature was 900 °C and that the doping of Eu3+ and charge compensators (K+, Li+, Na+, NH4+) had no effect on the crystal phase change. SrMo0.5W0.5O4:Eu3+ has major excitation peaks at 273 nm, 397 nm, and 464 nm, and a main emission peak at 615 nm, making it a potential red fluorescent material to be used as a down converter in UV LEDs (273 nm and 397 nm) and blue light LEDs (464 nm) to achieve Red emission. The emission spectra of Sr1-yMo0.5W0.5O4:yEu3+(y = 0.005, 0.01, 0.02, 0.05, 0.07) excited at 273 were depicted, with the Eu3+ concentration increasing the luminescence intensity first increases and then decreases, the emission peak intensity of SrMo0.5W0.5O4:Eu3+ achieves its maximum when the doping concentration of Eu3+ is 1%, and the critical transfer distance is calculated as 25.57 Å. When various charge compensators such as K+, Li+, Na+, and NH4+ are added to SrMo0.5W0.5O4:Eu3+, the NH4+ shows the best effect with the optimal doping concentration of 3wt%. The SrMo0.5W0.5O4:Eu3+,NH4+ color coordinate is (0.656,0.343), which is close to that of the ideal red light (0.670,0.333).

Pseudo-2D Layered Organic-Inorganic Manganese Bromide with a Near-Unity Photoluminescence Quantum Yield for White Light-Emitting Diode and X-Ray Scintillator.

Eco-friendly lead-free organic-inorganic manganese halides (OIMHs) have attracted considerable attention in various optoelectronic applications because of their superior optical properties and flexible solution processibility. Herein, we report a novel pseudo-2D layered OIMH (MTP)2 MnBr4 (MTP: methyltriphenylphosphonium), which exhibits intense green emission under UV/blue or X-ray excitation, with a near-unity photoluminescence quantum yield, high resistance to thermal quenching (I150 °C =84.1 %) and good photochemical stability. These features enable (MTP)2 MnBr4 as an efficient green phosphor for blue-converted white light-emitting diodes, demonstrating a commercial-level luminous efficiency of 101 lm W-1 and a wide color gamut of 116 % NTSC. Moreover, these (MTP)2 MnBr4 crystals showcase outstanding X-ray scintillation properties, delivering a light yield of 67000 photon MeV-1 , a detection limit of 82.4 nGy s-1 , and a competitive spatial resolution of 6.2 lp mm-1 for X-ray imaging. This work presents a new avenue for the exploration of eco-friendly luminescent OIMHs towards multifunctional light-emitting applications.

Wet chemical synthesis of BiPO4 :Eu3+ phosphor for w-LED application.

The synthesis of BiPO4 :Eu3+ phosphors has been achieved via a wet chemical process. X-ray diffraction patterns show that the phase of the as-prepared samples matches very well with the standard BiPO4 structure. At 395 nm, the highest excitation intensity was observed. Following 395 nm excitation, two characteristic emission peaks at 592 nm and 616 nm were shown. At 0.5 mol% of Eu3+ ions, concentration quenching occurred. The particle size is within the micrometre range, according to the scanning electron microscope magnification. The chromaticity coordinates for wavelengths 592 nm and 616 nm are (x = 0.586, y = 0.412) and (x = 0.682, y = 0.317), respectively. The findings imply that the prepared phosphor may be used to create white light-emitting diodes.

Recent advances in process engineering and upcoming applications of metal-organic frameworks.

Progress in metal-organic frameworks (MOFs) has advanced from fundamental chemistry to engineering processes and applications, resulting in new industrial opportunities. The unique features of MOFs, such as their permanent porosity, high surface area, and structural flexibility, continue to draw industrial interest outside the traditional MOF field, both to solve existing challenges and to create new businesses. In this context, diverse research has been directed toward commercializing MOFs, but such studies have been performed according to a variety of individual goals. Therefore, there have been limited opportunities to share the challenges, goals, and findings with most of the MOF field. In this review, we examine the issues and demands for MOF commercialization and investigate recent advances in MOF process engineering and applications. Specifically, we discuss the criteria for MOF commercialization from the views of stability, producibility, regulations, and production cost. This review covers progress in the mass production and formation of MOFs along with future applications that are not currently well known but have high potential for new areas of MOF commercialization.

Suppressing ion migration of CsPbBrxI3-xnanocrystals by Nickel doping and the application in high-efficiency WLEDs.

All inorganic perovskite nanocrystals CsPbX3(X = Cl, Br, I) are the great potential candidates for the application of high-performance light emitting diodes (LED) due to their high Photoluminescence Quantum Yield (PLQY), high defect tolerance, narrow full-width half-maximum and tunable wavelength of 410-700 nm. However, the application of red-emitting (630-650 nm) CsPbBrxI3-xnanocrystals are perplexed by phase segregation due to the composition of mixed halides and the difference in halide ion mobility. Herein, we provide an effective strategy to suppressing the migration of Br/I ions through Ni2+doping via a facile Hot-Injection method and the PLQY was improved as well. DFT calculations show that the introduction of Ni2+causes a slight contraction of the host crystal structure, which improves the bond energy between Pb and halides and reduces the level of surface defects. Therefore, the phase stability is improved by Ni2+doping because the phase segregation caused by ion migration in the mixed phase is effectively inhibited. Meanwhile, the non-radiative recombination in the exciton transition process is reduced and the PLQY is improved. What's more, benefiting from the suppressed ion migration and enhanced PLQY, we combine the Ni2+-doped CsPbBrxI3-xnanocrystals with different Br/I ratios and YAG: Ce3+phosphors as color conversion layers to fabricate high efficiency WLED. When the ratio of Br/I is 9:11, WLED has a color coordinate of (0.3621, 0.3458), the color temperature of 4336 K and presents a high luminous efficiency of 113.20 lm W-1, color rendering index of 94.9 under the driving current of 20 mA and exhibits excellent stability, which shows great potential in the application of LED.

Tunable lanthanide/transition metal ion-doped novel phosphors for possible application in w-LEDs: a review.

Lanthanide-based phosphors have been extensively investigated for their possible applications in solid-state lighting technologies especially for white-light-emitting diodes. In this review article emphasis has been laid on discussing the recent developments of phosphors for warm white-light production based on various optical characteristics such as quantum efficiency, thermal stability, short emission decay time, long-term stability, facile synthesis, and low cost of production. We have tried to cover the essential and latest discoveries of the lanthanide/rare earth-doped phosphors after 2010. New generations of narrow-band phosphors have also been included. The optical and material properties of several novel phosphors and their luminescence characteristics have been thoroughly discussed.

Yellow Emission Obtained by Combination of Broadband Emission and Multi-Peak Emission in Garnet Structure Na2YMg2V3O12: Dy3+ Phosphor.

The fabrication and luminescent performance of novel phosphors Na2YMg2V3O12:Dy3+ were investigated by a conventional solid-state reaction method. Under near-UV light, the Na2YMg2V3O12 host self-activated and released a broad emission band (400-700 nm, with a peak at 524 nm) ascribable to charge transfer in the (VO4)3- groups. Meanwhile, the Na2YMg2V3O12:Dy3+ phosphors emitted bright yellow light within both the broad emission band of the (VO4)3- groups and the sharp peaks of the Dy3+ ions at 490, 582, and 663 nm at a quenching concentration of 0.03 mol. The emission of the as-prepared Na2YMg2V3O12:Dy3+ phosphors remained stable at high temperatures. The obtained phosphors, commercial Y2O3:Eu3+ red phosphors, and BaMgAl10O17:Eu2+ blue phosphors were packed into a white light-emitting diode (WLED) device with a near-UV chip. The designed WLED emitted bright white light with good chromaticity coordinates (0.331, 0.361), satisfactory color rendering index (80.2), and proper correlation to a color temperature (7364 K). These results indicate the potential utility of Na2YMg2V3O12:Dy3+ phosphor as a yellow-emitting phosphor in solid-state illumination.

White Light Emitting MZr4(PO4)6:Dy3+ (M = Ca, Sr, Ba) Phosphors for WLEDs.

A series of MZr4(PO4)6:Dy3+ (M = Ca, Sr, Ba) phosphors were prepared by the solid state diffusion method. Confirmation of the phase formation and morphological studies were performed by X-ray powder diffraction (XRD) measurements and scanning electron microscopy, respectively. Photoluminescence (PL) properties of these phosphors were thoroughly analyzed and the characteristic emissions of Dy3+ ions were found to arise from them at an excitation wavelength of 351 nm. The PL emission spectra of the three phosphors were analyzed and compared. The CIE chromaticity coordinates assured that the phosphors produced cool white-light emission and hence, they are potential candidates for UV excited white-LEDs (WLEDs). Graphical Abstract ᅟ.

Luminescence and energy-transfer properties of color-tunable Ca2Mg0.25Al1.5Si1.25O7:Ce(3+)/Eu(2+)/Tb(3+) phosphors for ultraviolet light-emitting diodes.

A series of Ca2Mg0.25Al1.5Si1.25O7:Ce(3+)/Eu(2+)/Tb(3+) phosphors was been prepared via a conventional high temperature solid-state reaction and their luminescence properties were studied. The emission spectra of Ca2Mg0.25Al1.5Si1.25O7:Ce(3+),Eu(2+) and Ca2Mg0.25Al1.5Si1.25O7:Ce(3+),Tb(3+) phosphors show not only a band due to Ce(3+) ions (409 nm) but also as a band due to Eu(2+) (520 nm) and Tb(3+) (542 nm) ions. More importantly, the effective energy transfer from Ce(3+) to Eu(2+) and Tb(3+) ions was confirmed and investigated by emission/excitation spectra and luminescent decay behaviors. Furthermore, the energy level scheme and energy transfer mechanism were investigated and were demonstrated to be of resonant type via dipole-dipole (Ce(3+) to Eu(2+)) and dipole-quadrupole (Ce(3+) to Tb(3+)) reactions, respectively. Under excitation at 350 nm, the emitting color could be changed from blue to green by adjusting the relative doping concentration of Ce(3+) and Eu(2+) ions as well as Ce(3+) and Tb(3+) ions. The above results indicate that Ca2Mg0.25Al1.5Si1.25O7:Ce(3+),Eu(2+)/Tb(3+) are promising single-phase blue-to-green phosphors for application in phosphor conversion white-light-emitting diodes.

Spinel-Based ZnAl2O4: 0.5%Cr3+ Red Phosphor Ceramics for WLED.

To address the issue of the lack of red light in traditional Ce3+: YAG-encapsulated blue LED white light systems, we utilized spark plasma sintering (SPS) to prepare spinel-based Cr3+-doped red phosphor ceramics. Through phase and spectral analysis, the SPS-sintered ZnAl2O4: 0.5%Cr3+ phosphor ceramic exhibits good density, and Cr3+ is incorporated into [AlO6] octahedra as a red emitting center. We analyzed the reasons behind the narrow-band emission and millisecond-level lifetime of ZAO: 0.5%Cr3+, attributing it to the four-quadrupole interaction mechanism as determined through concentration quenching modeling. Additionally, we evaluated the thermal conductivity and thermal quenching performance of the ceramic. The weak electron-phonon coupling (EPC) effects and emission from antisite defects at 699 nm provide positive assistance in thermal quenching. At a high temperature of 150 °C, the thermal conductivity reaches up to 14 W·m-1·K-1, and the 687 nm PL intensity is maintained at around 70% of room temperature. Furthermore, the internal quantum efficiency (IQE) of ZAO: 0.5%Cr3+ phosphor ceramic can reach 78%. When encapsulated with Ce3+: YAG for a 450 nm blue LED, it compensates for the lack of red light, adjusts the color temperature, and improves the color rendering index (R9). This provides valuable insights for the study of white light emitting diodes (WLEDs).