Composition and properties tailoring in Mg2+ codoped non-stoichiometric LuAG:Ce,Mg scintillation ceramics

A comprehensive study of the optical, radioluminescence and scintillation properties of both the Lu³⁺ rich and Lu³⁺ deficient non-stoichiometric Lu_3+xAG:Ce,Mg (Lu_3+xAl₅O₁₂:Ce,Mg, x = −4, −1, +1 and +4 at.%) ceramics are performed, completed further by the microstructure and defects characterization. Small deviation from the stoichiometric composition as well as Mg²⁺ codoping plays a crucial role in ceramic transparency, radioluminescence intensity and the timing characteristics of scintillation response. The Lu_Al antisite defects could be suppressed efficiently by controlling Lu³⁺ content below stoichiometry of LuAG host. MgO (Mg²⁺ ions) as effective sintering aids, can improve both the optical quality and scintillation performance (light yield, scintillation decay times and the ratio of fast decay components). We generally discuss the composition dependence of defects and properties tailoring. We also performed the systematic comparative study with the stoichiometric LuAG:Ce,Mg ceramic and the commercial BGO and LuAG:Ce single crystals.     

Fabrication and Scintillation Performance of Nonstoichiometric LuAG:Ce Ceramics

Nonstoichiometric LuAG:Ce Ceramics ([Lu_(1–x)Ce_x]₃Al₅O₁₂, x = 0.005) with different excess of Lu³⁺ were designed on the basis of Lu₂O₃‐Al₂O₃ phase diagram and fabricated by a solid‐state reaction method. Without using any traditional sintering aids, pure phase and good optical performance were obtained in such a Lu‐rich LuAG:Ce ceramics. In addition, scintillation efficiency and light yield of 1% excess of Lu³⁺ ceramic sample were found 16 times and 1.82 times higher than that of commercial Bi₄Ge₃O₁₂ (BGO) single crystals, respectively. Such values are comparable or even better than those in most of LuAG:Ce single crystals. However, antisite defects were also induced by excess of Lu doping, whose luminescence was found at 350–410 nm in Lu‐rich LuAG:Ce ceramics. The relationship of excess content of Lu and the microstructure, optical quality, and scintillation performance were clarified and discussed. Furthermore, by utilizing X‐ray absorption near edge spectroscopy technique, the charge state stability of cerium in Lu‐rich LuAG:Ce ceramics was examined. It appears that the excess of isovalence Lu³⁺ doping has a negligible effect on the cerium valence instability and creation of stable Ce⁴⁺ center.     

Production of nanopowder and bulk aluminate ceramic scintillators

The developed nanotechnology makes it possible to prepare lots of standard powders of Aluminates such as lutetium and yttrium orthorombic LuAlO₃, YAlO₃ (LuAP, YAP – perovskite), aluminum garnets Lu₃Al₅O₁₂, Y₃Al₅O₁₂ (LuAG, YAG) with cubic structure and aluminates with monoclinic structure Lu₄Al₂O₉, Y₄Al₂O_9, (LuAM, YAM). Powders of scintillation materials are prepared by sol-gel method, co-precipitation method and a combination of sol-gel method with combustion reactions. Crystallization process of LuAG phase starts at 900 °C. At lower temperatures, during the pyrolysis of the gel, amorphous powders have been produced. After pyrolysis of the gels without additives of aminoacetic acid a mixture of LuAG+Lu₂O₃ has been formed instead of LuAP. New phase of LuAP in a cubic form is detected. Diffraction peak profile analyzes and scanning electron microscope (SEM) investigations are performed to approximately establish grain size of the obtained powder. Thermogravimetry analysis (TGA) was carried out for detection of thermal effects in the range up to sintering temperature. Perovskite phases of aluminates have been synthesized via pyrolysis (at <900 °C) of the gel. Prepared nanopowders of aluminates are sintered using spark plasma processing. The best density of YAG has been detected at the following conditions of SPS process: 1650 °C/3 min/40 MPa.     

Micromechanical properties of Dy3+ ion-doped (LuxY1-x)3Al5O12 (x = 0, 1/3, 1/2) single crystals by indentation and scratch tests

Three kinds of Dy³⁺ ion-doped (Lu_xY_1-x)₃Al₅O₁₂ (x = 0, 1/3, 1/2) single crystals fabricated by the Czochralski method with 4 at.% Dy³⁺ ion doping were investigated by indentation and scratch techniques under Vickers, Knoop, Berkovich, and spherical indenters to understand the influence of Lu ion on micromechanical properties and fracture behavior of Y₃Al₅O₁₂ (i.e. YAG for x = 0) single crystals. The largest (or smallest) values of hardness, elastic modulus, and fracture toughness were found for x = 1/3 (or 1/2). The indentation size effect was explained by four different models with the Hays-Kendall approach being the most suitable one to determine the true hardness. Fracture toughness values of YAG crystals obtained by the Vickers hardness method agreed with those obtained by scratching with a spherical indenter based on linear elastic fracture mechanics.     

Sr3Lu (VO4)3: Eu3+ red-emitting phosphors for warm white LEDs

A series of novel red emission phosphors Sr₃Lu_1-x(VO₄)₃:xEu³⁺(x = 0.007, 0.009, 0.02, 0.04, 0.06) were synthesized successfully by traditional high-temperature solid-state reaction. The results of X-ray diffraction (XRD) reveal the doped Eu³⁺ ions have replaced the lattice sites of Lu³⁺ ions. The diffuse reflectance spectra illustrate the energy gap of Sr₃Lu(VO₄)₃ host is 3.61 eV. The room-temperature steady-state fluorescence spectra show that these phosphors can be effectively pumped by the charge-transfer band (CTB) of the host in near ultraviolet (NUV) spectral region and then produce strong and pure red emission at 615 nm originated from ⁵D₀ → ⁷F₂ electric dipole transition of Eu³⁺. The Commission Internationale de L’Eclairage (CIE) coordinates of Sr₃Lu_0.96(VO₄)₃:0.04Eu³⁺ are (x = 0.65, y = 0.35), which are very close to the red standard of National Television Standards Committee NTSC (0.67, 0.33). The fabricated warm white-light-emitting diodes (LED) demonstrate high color-rendering index Ra as 93. The results imply the red-emitting Sr₃Lu(VO₄)₃:Eu³⁺ phosphors could be potentially utilized in the fields of solid-state lighting.     

Dy3+/Ce3+ Codoped YAG Transparent Ceramics for Single‐Composition Tunable White‐Light Phosphor

Superior optical, thermal, and mechanical properties of transparent ceramics are very important in the applications of solid lasers, solid‐state lighting, and transparent armors. Herein, a series of (Dy_0.03Ce_xY_0.97?x)₃Al₅O₁₂ transparent ceramics were fabricated using vacuum reactive sintering method. Importantly, these Dy³⁺/Ce³⁺ codoped yttrium aluminum garnet (YAG) transparent ceramics served as single‐composition tunable white‐light phosphors for UV‐LEDs is developed for the first time. By combining with commercially available UV‐LEDs directly, the optimal chromaticity coordinates and correlated color temperature (CCT) are (x = 0.33, y = 0.35) and 5609 K, respectively. Notably, the codoping of Ce³⁺ enhances the luminescent intensity of Dy³⁺ ions while excited at 327 nm. The emission color of YAG transparent ceramics can be tuned from white to yellow through energy transfer between Dy³⁺ and Ce³⁺. These new phosphors, possessing of pure CIE chromaticity and environmentally friendly nature, are promising for applications in white UV‐LEDs.     

Polycrystalline Ho: LuAG laser ceramics: Fabrication,microstructure, and optical characterization

Ho:Lu₃Al₅O₁₂(LuAG) transparent ceramics are potential 2 μm eye‐safe laser materials. Polycrystalline 0.8 at.% Ho:LuAG ceramics with high optical quality were successfully fabricated by solid‐state reactive sintering of high‐purity oxide powders. The microstructure, the optical transmission, the spectrum characteristic, and the laser performance were investigated in this paper. The average grain size of Ho:LuAG ceramics vacuum sintered at 1830°C for 30 hour is about 14 μm. The in‐line transmittance of the sample is measured to be 81.7% and 82.0% at 1000 and 2250 nm, respectively. The absorption and the emission cross sections are calculated to be 0.88 × 10^?20 cm² at 1906 nm and 1.26 × 10^?20 cm² at 2094 nm. Using a thulium‐doped yttrium‐lithium‐fluoride (Tm:YLF) laser with the central wavelength of 1907.5 nm as the pump source, 2.67 W continuous wave (CW) laser operation at 2100.74 nm was obtained with a slope efficiency of 26.5%. The beam quality factor M² was calculated to be 1.1, which indicated nearly diffraction‐limited beam propagation and the laser was the fundamental TEM₀₀ Gaussian mode.     

Overcoming the cyan gap for full-spectrum lighting using cation-substitution-induced rigid Ca2YZr2Al3O12:Ce3+

Mixing multicolor phosphors for simulating the full spectrum of sunlight illumination is a popular solution to obtain high-quality white light. However, there is still a need to overcome the cyan gap in the emission spectrum. In this work, a series of garnet Ca₂Y_0.94–xLu_xZr_2–yHf_yAl₃O₁₂:6%Ce³⁺ (abbreviated as CY_0.94–xLu_xZr_2–yHf_yA:Ce³⁺) cyan phosphors are designed and prepared by substituting Y³⁺ and Zr⁴⁺ in Ca₂YZr₂Al₃O₁₂:6%Ce³⁺ with Lu³⁺ and Hf⁴⁺ with smaller ionic radius and larger mass. Under 405 nm violet light excitation, the optimized Ca₂Y_0.88Lu_0.06Hf₂Al₃O₁₂:6%Ce³⁺ (CY_0.88Lu_0.06Hf₂A:Ce³⁺) shows a bright cyan emission band in the range of 430–750 nm with the peak at 477 nm. Importantly, the emission intensity and thermal stability properties of CY_0.88Lu_0.06Hf₂A:Ce³⁺ were significantly improved by 58% and 47% compared to those of pure Ca₂YZr₂Al₃O₁₂:Ce³⁺. Small and heavy cation substitution could induce highly stable rigid structure, thus enhancing emission intensity and stability. The color rendering index increases from 84.5 to 92.0 after supplementing CY_0.88Lu_0.06Hf₂A:Ce³⁺ phosphor in white light-emitting diode devices combining commercial red, green, and blue phosphors with a violet chip, indicating its practical application in full-spectrum lighting. The present study provides promising strategies for the design and development of efficient cyan materials for high-quality full visible spectrum light-emitting diode lighting.     

Microstructure and optical properties of Nd: YAG transparent ceramics with the addition of Lu3+ ions

The Nd:YAG transparent ceramics with addition of Lu³⁺ ions were fabricated by co-precipitation method and vacuum sintering. Pure YAG phases were obtained when Lu³⁺ ion content was kept under 4.5?at.-%. Lattice constant of polycrystalline ceramic with 0.8?at.-% Lu³⁺ calculated from XRD patterns was similar to that of YAG single crystal, and its fluorescent intensity arising from ⁴F3/2?→?⁴I9/2 transition of Nd³⁺ ions reached the maximum although the ceramic was opaque. The results indicated that Lu³⁺ ions under 1.5?at.-% relieved strains from lattice distortion and enhanced the fluorescent intensity.     

Fabrication and Characterization of Transparent (Y0.98−xTb0.02Eux)2O3 Ceramics with Color‐Tailorable Emission

Transparent (Y_0.98?xTb_0.02Eu_x)₂O₃ (x = 0–0.04) ceramics with color‐tailorable emission have been successfully fabricated by vacuum sintering at the relatively low temperature of 1700°C for 4 h. These ceramics have the in‐line transmittances of ~73%–76% at 613 nm, the wavelength of Eu³⁺ emission (the ⁵D₀→⁷F₂ transition). Thermodynamic calculation indicates that the Tb⁴⁺ ions in the starting oxide powder can essentially be reduced to Tb³⁺ under ~10^?3 Pa (the pressure for vacuum sintering) when the temperature is above ~394°C. The photoluminescence excitation (PLE) spectra of the transparent (Y_0.98?xTb_0.02Eu_x)₂O₃ ceramics exhibit one spin‐forbidden (high‐spin, HS) band at ~323 nm and two spin‐allowed (low‐spin, LS) bands at ~303 and 281 nm. Improved emissions were observed for both Eu³⁺ and Tb³⁺ by varying the excitation wavelength from 270 to 323 nm, without notably changing the color coordinates of the whole emission. The transparent (Y_0.98Tb_0.02)₂O₃ ceramic exhibits the typical green emission of Tb³⁺ at 544 nm (the ⁵D₄→⁷F₅ transition). With increasing Eu³⁺ incorporation, the emission color of the (Y_0.98?xTb_0.02Eu_x)₂O₃ ceramics can be precisely tailored from yellowish‐green to reddish‐orange via the effective energy transfer from Tb³⁺ to Eu³⁺ under the excitation with the peak wavelength of the HS band. At the maximum Eu³⁺ emission intensity (x = 0.02), the ceramic shows a high energy‐transfer efficiency of ~85.3%. The fluorescence lifetimes of both the 544 nm Tb³⁺ and 613 nm Eu³⁺ emissions were found to decrease with increasing Eu³⁺ concentration.     

Effect of Ba Nonstoichiometry in Bax(Zr0.8Y0.2)O3−δ on Population of 5‐Coordinated Y

The local environments of Y in the Y‐substituted BaZrO₃ of the starting compositions of Ba_x(Zr_0.8Y_0.2)O_3?δ (x = 0.97, 1.0, 1.03, and 1.06) were analyzed by ⁸⁹Y magic angle spinning NMR spectroscopy. The result showed a strong population dependence of 5‐coordinated Y³⁺ ions mostly at the B site on the Ba contents. The enhancement of Ba contents by 9 at% (from 0.97 to 1.06 in the starting Ba contents) in a nominal composition increased the amount of 5‐coordinated Y³⁺ ions from 35% ± 7% to 49% ± 5%, suggesting the importance of maximizing the Ba contents to populate more oxygen vacancies which is related to the concentration of protons incorporated during the hydration process. The wide variation in the lattice parameter of yttrium‐substituted BaZrO₃ perovskite materials in previous reports was reinterpreted with the variation in the Ba contents resulting from the evaporation of BaO during the sintering processes. Y³⁺ ions were confirmed to replace mainly the Zr⁴⁺ ions, as expected, and a tendency of oxygen vacancy clustering near the Y³⁺ ions was discussed.     

Electrical properties of Y/Mg modified NiO simple oxides for negative temperature coefficient thermistors

The semiconductors based on simple oxide have unique features with controllable electrical property by element doping. Y³⁺ doped NiO (Ni_1−xY_xO, x ≤ 0.01) and Mg²⁺ substituted Ni_0.995Y_0.005O (Ni_0.995−yY_0.005Mg_yO, y ≤ 0.5) powders were synthesized by a wet chemical method. The related ceramics were obtained by conventional ceramic processing. Phase component, microstructure, electrical property and temperature sensitivity of the prepared ceramics were investigated. All ceramics have a rock-salt type crystalline structure. The room-temperature resistivity of the ceramics can be widely adjusted from 254 to 12 322 Ω·cm by changing the concentrations of Y³⁺ and Mg²⁺ ions. The samples show typical characteristics of negative temperature coefficient of resistivity and have high temperature sensitivity with material constants higher than 4745 K. The analysis of impedance spectra indicates that the electrical properties resulted from both grain effect and grain boundary effect. Both band conduction and small polaron hopping were proposed as possible conduction mechanisms in the studied ceramics.     

Effects of Sintering Aids on the Transparency and Conversion Efficiency of Cr4+ Ions in Cr: YAG Transparent Ceramics

Tetravalent chromium‐doped Y₃Al₅O₁₂ ceramics were fabricated by solid‐state reactive sintering method using high‐purity Y₂O₃, α‐ Al₂O₃, and Cr₂O₃ powders as the starting materials. CaO and MgO were co‐doped as the sintering aids. The effects of TEOS and divalent dopants (CaO and MgO) on the optical qualities, the conversion efficiency of Cr⁴⁺ ions, and the microstructure evolutions of 0.1 at.% Cr⁴⁺: YAG ceramics were investigated. Fully dense, dark brown colored Cr⁴⁺: YAG ceramics with an average grain size of 3.1 μm were achieved. The in‐line transmittance of the as‐prepared ceramic at 2000 nm was 85.3% (4 mm thick), and the absorption coefficient at 1030 nm (the characteristic absorption peak of Cr⁴⁺ ions) was as high as 3.7 cm^?1, which was higher than that of corresponding single crystals fabricated by Czochralski method.     

Mixed precipitants derived nanocrystalline powders and RE doped LuAG transparent ceramics

Lu₃Al₅O₁₂ (LuAG) nanocrystalline powders were synthesized by using ammonium hydroxide (NH₄OH, AH) and ammonium hydrogen carbonate (NH₄HCO₃, AHC) as mixed precipitant. In the absence of sintering aids such as TEOS, MgO or ZrO₂, the obtained LuAG powders showed good sinterability in H₂ atmosphere (PLSH) at low temperature. The in-line transmittance of LuAG ceramic reached 81% in the whole visible light band from 400 nm to 800 nm. The average grain size of obtained transparent ceramics was ranged in 1–6 μm at different sintering temperatures by PLSH. Various kinds of rare earth ions, such as Nd, Yb, Ce, Pr, and Tm doped RE:LuAG transparent ceramics could be prepared by PLSH technology without sintering aids and HIP post-treatment. Through PLSH technology, RE:LuAG transparent ceramics show high optical quality and large aperture size.     

Effective calcination pretreatment of Lu2O3 powders for LuAG transparent ceramics

Lutetium aluminium garnet (LuAG) ceramics as host materials has been widely used in lighting, laser, displaying and scintillators after doping different rare earth ions. Right selection of raw powder and controlling its characteristics during the preparation can greatly improve the optical quality of transparent ceramics. In this paper, the influence of different pretreatment temperatures of commercial Lu₂O₃ powders in oxygen atmosphere on solid state sintering of LuAG ceramics was systematically investigated. The pretreatment gradually decreased the specific surface area of Lu₂O₃ powders and greatly removed the absorbed impurities, which seriously deteriorated the optical quality before. The mean particle size increased from 4.53 to 5.66 μm, and the in-line transmittance of samples (Thickness = 2 mm) at 1064 nm was 68.4% for the pretreated Lu₂O₃ powder at 1000 °C without any sintering additives. Further increase of pretreatment temperature would lead to the coarsening of Lu₂O₃ powders and the decrease of sintering activity, which finally resulted in a large number of micro pores in LuAG ceramics. These results revealed that the pretreatment of Lu₂O₃ powders has prodigious impact on the optical quality of LuAG transparent ceramics, and the adsorbed materials should be removed as much as possible for their applications in lasers or lighting.     

Dielectric and gyromagnetic structure modulations of Zn–Sn codoped yttrium–iron–garnet based on the density-generalized functional theory and P–V–L bond theory

Herein, the crystal structure, dielectric properties, and gyromagnetic characteristics of Zn–Sn codoped Y₃Zn_xSn_xFe_5−2xO₁₂ (x = 0.0–0.5) prepared using a conventional ceramic process were investigated. According to the first-principles’ calculations and complex crystal bonding theory, Zn²⁺–Sn⁴⁺ codoping can increase the relative dielectric constant (ε_r) by enhancing the average ionicity. The x-ray photoelectron spectroscopy (XPS) and Raman analysis results indicate that an appropriate amount of Zn²⁺–Sn⁴⁺ codoping can help improve the microscopic morphology, maintain the appropriate ratio of divalent iron ions, and reduce the microwave magnetic and electrical losses of YIG ferrites. The optimized microwave properties are as follows. Y₃Zn_0.3Sn_0.3Fe_4.4O₁₂ after sintering at 1400°C; ε_r = 15.6; dielectric loss, that is, tanδ_ε = 4.3 × 10⁻⁴; saturation magnetization, that is, 4πM_S = 2244 G; ferromagnetic resonance linewidth, that is, ΔH = 37 Oe. These properties can help improve the performance of high-frequency microwave components by enhancing the properties of ferrite.     

Lattice dynamics of yttria: A combined investigation from spectrum measurements and first-principle calculations

C-type Y₂O₃ ceramics (relative density ~94%) were prepared at 1500 °C for 2 hours with 1% wt. ZnO as sintering aid. The cell parameters of Y₂O₃ from Rietveld refinements are a = 10.6113(1) Å, V = 1194.8(1) ų. The vibrational modes / lattice dynamics of Y₂O₃ were investigated using vibrational spectra (Raman and infrared reflection spectra) and first-principle (DFT) calculations. Eight of the 22 predicted first-order Raman modes and 12 of 16 predicted IR modes are observed and reliably assigned. For the observed vibrational modes, an excellent linearity (f_exp = 1.023f_theo, R² = 0.9999) between frequency from calculations (f_theo) and that from measurements (f_exp) is observed. Accordingly, the corrected frequency (f_cor) of vibrational modes, phonon band structure, and density of phonon states (DOPS) of Y₂O₃ are presented, in which, the frequency of phonons of Y₂O₃ is ≤625.2 cm⁻¹ (wavelength ≥16.0 μm) with a gap of 30.6 cm⁻¹ from 486.0 to 516.6 cm⁻¹ (wavelength 20.6 - 19.4 μm) at room temperature. The modes with f_theo ≥292.5 cm⁻¹ (f_cor ≥299.2 cm⁻¹) are dominated by the vibrations of O²⁻ (light atom vibrations) and the vibrational modes with f_theo ≤239.0 cm⁻¹ (f_cor ≤244.5 cm⁻¹) are dominated by the vibrations of both Y³⁺ and O²⁻ (co-vibrations). The three modes T_u⁽⁷⁾ at 301.6 cm⁻¹, T_u⁽¹⁰⁾ at 333.7 cm⁻¹, and T_u⁽¹²⁾ at 369.7 cm⁻¹ of Y-O stretch vibrations dominate the phonon dielectric constant and dielectric loss of Y₂O₃ with more than 85% contributions.     

Lattice evolution and microwave dielectric properties of La-doped yttrium aluminum garnet ceramics

In this study, Y_3−xLa_xAl₅O₁₂ (0 ≤ x ≤ 0.09) ceramics were synthesized, and the phase composition, lattice evolution, and microwave dielectric properties were investigated in detail. Scanning electron microscopy confirms that the addition of moderate amounts of La₂O₃ improves the grain development of YAG ceramics, but excessive doping destabilizes the crystal structure. Transmission electron microscopy characterization shows that the variation of the dielectric properties of the samples with x-value is related to the occurrence of benign dislocation structures caused by modifications in the type and content of the A-site rare-earth ions. The variations in relative density, dielectric constant, and quality factor remain basically coordinated. The optimum microwave dielectric properties of La³⁺ doped YAG samples are exhibited as ε_r = 10.61, Q × f = 187, 542 GHz, τ_f = −31.2 ppm/°C when La₂O₃ is doped at x = 0.015.     

The Molten Salt Synthesis of (Y1−xEux)4Al2O9 Solid Solution Powders and Their PL Properties

(Y_1?xEu_x)₄Al₂O₉ solid solution powders can be easily prepared by a simple and convenient method, which effectively combined a molten salt process with a chemical co‐precipitation technique. All the samples were characterized by XRD, SEM, and photoluminescence (PL) spectra techniques. The results show that the incorporation of NaCl salt can greatly promote the formation and crystallization of (Y_1?xEu_x)₄Al₂O₉ crystallites, and lower their synthesizing temperature, and that their particle size and morphology strongly rely on x value, which finally dominates their PL properties. The prominent emission intensity of ⁵D₀→⁷F₂ transition rather than ⁵D₀→⁷F₁ indicates doped Eu³⁺ cations occupy Y³⁺ position in monoclinic Y₄Al₂O₉, which is sensitive to Eu³⁺ local environment, and at x = 0.10, there exist a maximum PL intensity due to the concentration quenching effect.     

Al2O3–Ce:YAG composite phosphor ceramics for white laser lighting: Novel preparation and regulatable properties

In this work, a series of Al₂O₃–Ce:YAG phosphor powders were synthesized by regulating the excess Al³⁺ of (Y,Ce)₃Al₅O₁₂ via coprecipitation method for the first time, where Al³⁺, Ce³⁺, and Y³⁺ elements were uniformly distributed. With the increase of Al³⁺ content, the morphology of the powders changed from wormlike shapes to flaky shapes, and Y₃Al₅O₁₂ phases had a tendency to convert to YAlO₃ phases. The x wt.% Al₂O₃–(Y_0.999Ce_0.001)₃Al₅O₁₂ (x = 20, 30, 40, 50, 60, and 70) composite phosphor ceramics (CPCs) were obtained by vacuum sintering (1775°C × 10 h), where Al₂O₃ and Ce:YAG phases were also well-distributed. When the Al₂O₃ content was 30–40 wt.%, the average grain size of Al₂O₃ was close to that of Ce:YAG. A solid-state laser lighting device was constructed by a 450 nm laser source and CPCs in a reflection mode. By adjusting the laser power, the correlated color temperature (CCT) values of white laser diodes (LDs) were achieved close to the standard white light of 6500 K. Impressively, the white LDs equipped with the 40 wt.% Al₂O₃-containing CPCs showed the optimum CCT of 6498 K (color coordinates: 0.31 and 0.38), as well as a high luminous flux of 1169 lm and efficiency of 166 lm/W at the LD power of 7.05 W. This work has provided a potential idea to optimize the composition uniformity of Al₂O₃–Ce:YAG CPCs as also to explore their excellent performance in the application of white laser lighting.