Ce 3+ Activated CaYAlO4 orange light laser ceramic, method of preparation and use

Abstract

The application belongs to the technical field of solid-state luminescent materials and laser lighting, and relates to a Ce 3+ activated CaYAlO4 orange laser ceramic, a preparation method and application. The material takes CaYAlO4 as a matrix, takes Ce 3+ as an activator, replaces Al in an AlO6 framework with Sc 3+ , activates hidden Y-site Ce 3+ orange emission centers, and further introduces Si to adjust the rigidity of the Al-site framework and inhibit structural distortion and thermal quenching caused by Sc substitution. The chemical general formula of the material can be represented as CaYAl 1‑x‑ y Sc x Si y O4:zCe 3+ . The material has a broadband excitation in the range of 400-550 nm, emits 580-600 nm orange light under 460 nm blue light excitation, and has an emission decay lifetime of about 23 ns at 600 nm. The laser ceramic of the application can be assembled with a 450 nm blue laser to form a high-brightness orange laser lighting device, and is suitable for high-power laser lighting, long-distance night indication and high-penetration lighting.

Description

Technical Field

[0001] This invention belongs to the field of solid-state luminescent materials and laser illumination technology in physics, specifically relating to a method for controlling Ce through Sc. 3+ CaYAlO4-based orange-emitting oxide fluorescent ceramics with Si as a vacancy and improved lattice rigidity, their preparation method, and their application in blue laser lighting devices. Background Technology

[0002] Laser diodes can operate at power densities far exceeding those of ordinary LEDs, offering advantages such as high brightness, good directionality, and strong collimation. They have important applications in automotive headlights, airport lighting, projection displays, search and rescue lighting, and other high-power lighting systems. These applications require light-emitting conversion materials to possess characteristics such as high thermal conductivity, chemical stability, resistance to light saturation, and ease of ceramization. Summary of the Invention

[0003] To address the shortcomings or deficiencies of existing technologies, this invention provides a Ce 3+ Activated CaYAlO4 orange laser ceramic.

[0004] Therefore, the laser ceramic provided by this invention uses CaYAlO4 as the matrix and Ce as the substrate. 3+ It is a luminescence activator and contains substances for regulating Ce. 3+ The Sc element serves as a placeholder; the Sc element partially replaces the Al sites in the AlO6 framework of CaYAlO4, making Ce... 3+ The space is shifted from Ca to Y, thus generating Ce at position Y. 3+ Orange light emission center. The general chemical formula of the fluorescent ceramic is CaYAl. 1-x Sc x O4:zCe 3+ Where x is the doping concentration of Sc, and z is the doping concentration of Ce. 3+ The doping concentration is 0.02≤x≤0.30, 0.001≤z≤0.10; preferably 0.05≤x≤0.20.

[0005] In a further embodiment, the laser ceramic also contains Si; its general chemical formula is CaYAl. 1-x-y Sc x Si y O4:zCe 3+ Where y is the doping concentration of Si, 0.02≤x≤0.30, 0.01≤y≤0.15, 0.001≤z≤0.10; preferably x=0.20, y=0.05~0.10.

[0006] Furthermore, the Y-position Ce 3+ The luminescence decay lifetime of the orange light emission center is 20–30 ns.

[0007] The present invention also provides a method for preparing the above-mentioned laser ceramic, the method comprising the following steps:

[0008] Step 1: Weigh the raw materials containing Ca, Y, Al, Ce and Sc according to the molar amounts of each element in the target chemical formula, add anhydrous ethanol or deionized water and mix and grind; wherein the raw materials containing Ca are selected from CaCO3 or CaO, the raw materials containing Y are selected from Y2O3 or Y(NO3)3, the raw materials containing Al are selected from Al2O3, Al(OH)3 or AlF3, the raw materials containing Ce are selected from CeO2 or Ce(NO3)3, and the raw materials containing Sc are selected from Sc2O3; Step 2: Dry the mixture at 80–120 °C; then pre-calcine it at 1000–1550 °C for 2–10 hours to obtain fluorescent powder; Step 3: Grind the powder into a fine powder, sieve it, press it into tablets or isostatically press it into shape, and sinter it at 1400-1700 ℃ for 1-10 hours to obtain dense fluorescent ceramics; finally, cut, grind and polish it to obtain laser ceramic sheets that can be used for laser lighting.

[0009] In a further embodiment, in step 1, raw materials containing Ca, Y, Al, Ce, and Sc are weighed according to the molar amounts of each element in the target chemical formula, and then mixed and ground with anhydrous ethanol or deionized water; the raw material containing Si is selected from SiO2.

[0010] The laser ceramic material of the present invention modulates the lattice structure and Ce by replacing Al sites in the AlO6 framework with Sc. 3+ Placeholder preference, activate the hidden Y position Ce 3+ The orange light emission center, with a lifetime of less than 100 ns, is highly advantageous for laser illumination applications. The Sc preferentially replaces the Al sites in the AlO6 octahedral framework of CaYAlO4, forming ScO6 structural units. Because Sc... 3+ Ionic radius greater than Al 3+ Sc substitution causes lattice expansion, which in turn causes Ce to expand. 3+ The occupancy is shifted from the traditional Ca position to the Y position. The Y position Ce... 3+ The center emits orange light at 580–600 nm when excited by blue light near 460 nm, with a decay lifetime of about 23 ns.

[0011] In a further scheme, the rigidity of the Al site framework is further adjusted by Si, thermal quenching is suppressed, structural distortion caused by Sc substitution is reduced, and the external quantum efficiency and high-temperature luminescence retention rate of orange light are improved. The external quantum efficiency of the ceramic can be improved to about 31% by Sc / Si synergistic regulation, and the luminescence intensity retention rate at 150 °C can be improved to about 53%.

[0012] Ce 3+ 5d -4 f Transitions are permitted transitions, typically possessing radiative lifetimes on the order of nanoseconds, suitable for operation at high photon fluxes. However, Ce... 3+ 4 free ions f -5 d The transition energy is relatively high; to achieve orange light emission of approximately 600 nm in oxides, significant crystal field splitting and centroid displacement are required. Existing typical Ce... 3+ Activated oxide ceramics such as YAG:Ce 3+ It mainly emits yellow light, with the peak position usually around 550 nm, making it difficult to obtain true orange light.

[0013] The CaYAlO4 structure contains separate Ca and Y layers. (Traditional CaYAlO4:Ce) 3+ Materials typically exhibit Ca sites and Ce sites. 3+ The center causes 430 nm blue light emission, while the Y-position Ce 3+ The center failed to be effectively activated due to its high formation energy and low occupancy rate.

[0014] Compared with existing technologies, this invention utilizes Sc-induced site regulation to activate hidden Y-site Ce in mature CYA matrix. 3+ Orange Light Center, realizing Ce 3+ Orange light emission at longer wavelengths (580–600 nm) in oxide ceramics; the material obtained in this invention belongs to Ce. 3+ The activated 600 nm oxide orange-emitting ceramic material maintains a decay lifetime of less than 100 nanoseconds, which can alleviate luminescence saturation under strong laser excitation. Furthermore, Si further improves lattice rigidity and thermal stability, enhancing external quantum efficiency and high-temperature luminescence retention.

[0015] Orange laser illumination exhibits superior penetration and visual recognition in complex environments such as fog, rain, and smoke, making it suitable for long-distance nighttime indication and high-penetration lighting. Existing orange laser oxide conversion materials largely rely on Eu. 3+ Eu 2+ or Mn 4+ Activated ions, with their long excited-state lifetimes, are prone to excited-state accumulation, absorption, and optical saturation under strong laser excitation, limiting stable output in high-power laser illumination. The material of this invention can be fabricated as a highly dense fluorescent ceramic and can be combined with a blue laser to form a highly directional and bright orange laser illumination device. Specifically, the laser ceramic of this invention can be assembled with a 450 nm blue laser to form a high-brightness orange laser illumination device. Attached Figure Description

[0016] Figure 1The XRD patterns of the materials prepared in the embodiments of the present invention are as follows: CaYAlO4:1.0%Ce (Example 1) 3+ XRD patterns of the CaYAlO4 samples in Example 3 (1.0% Ce, 10% Sc), Example 5 (1.0% Ce, 20% Sc), and Example 7 (1.0% Ce, 20% Sc, 10% Si).

[0017] Figure 2 For Example 1, CaYAlO4: 1.0%Ce 3+ Excitation / emission spectra of CaYAlO4:1.0%Ce,20%Sc in Example 5.

[0018] Figure 3 The emission lifetime decay curves of the CaYAlO4 samples in Example 2 (1.0%Ce, 5%Sc), Example 3 (1.0%Ce, 10%Sc), and Example 5 (1.0%Ce, 20%Sc) at 600 nm are approximately 23 ns.

[0019] Figure 4 Example 1: CaYAlO4: 1.0%Ce 3+ Examples of ceramic samples are shown: CaYAlO4 (1.0%Ce, 10%Sc) in Example 3, CaYAlO4 (1.0%Ce, 20%Sc) in Example 5, CaYAlO4 (1.0%Ce, 5%Sc, 5%Si) in Example 6, and CaYAlO4 (1.0%Ce, 5%Sc, 10%Si) in Example 7. The previous row shows the actual ceramic samples, and the next row shows the samples under 365nm and 460nm excitation.

[0020] Figure 5 The emission spectra of the CaYAlO4 samples (Example 3: 1.0%Ce, 10%Sc), (Example 5: 1.0%Ce, 20%Sc), (Example 6: 1.0%Ce, 20%Sc, 5%Si), and (Example 7: 1.0%Ce, 20%Sc, 10%Si) under 460 nm excitation are shown in (a). The external quantum efficiency (b) increased from 5% to 31%, and the temperature-dependent luminescence intensity (c) increased from 15% to 53%.

[0021] Figure 6 The emission spectra of the CaYAlO4:1.0%Ce,20%Sc,10%Si sample in Example 7 under different laser powers are shown.

[0022] Figure 7 The CaYAlO4:1.0%Ce,20%Sc,10%Si sample of Example 7 demonstrates its long-distance illumination effect at night using a blue laser lighting device. Specific implementation methods The present invention will be further described below with reference to the accompanying drawings and embodiments, but the scope of protection of the present invention is not limited to the following embodiments. Any equivalent substitutions or conventional adjustments made to the form of raw materials, sintering atmosphere, sintering method, sample thickness, device packaging method, etc., based on the technical concept of the present invention, shall fall within the scope of protection of the present invention.

[0023] The CaYAlO4-based orange-emitting oxide fluorescent ceramic of the present invention can be prepared by solid-state reaction combined with ceramic sintering. The general steps are as follows: weigh the raw materials containing Ca, Y, Al, Ce, Sc and optionally Si according to the target chemical formula, place them in an agate mortar, add anhydrous ethanol or deionized water and mix and grind for 20-120 minutes; dry the mixture at 80-120 °C; then pre-fire at 1000-1550 °C for 2-10 hours to obtain fluorescent powder; then grind the powder into fine powder, sieve it, press it into sheets or isostatically press it into shape, and sinter it at 1400-1700 °C for 1-10 hours to obtain dense fluorescent ceramic; finally, cut, grind and polish it to obtain fluorescent ceramic sheets that can be used for laser illumination.

[0024] Example 1: CaYAlO4:1.0%Ce 3+ Preparation of blue light emitting samples CaCO3, Y2O3, Al2O3, and CeO2 were weighed as raw materials according to a Ca:Y:Al:Ce molar ratio of 1:0.99:1:0.01. An appropriate amount of anhydrous ethanol was added, and the mixture was ground and mixed for 20 minutes. After drying at 80℃, the mixture was pre-calcined at 600℃ for 4 hours in a high-temperature furnace and then finely ground to obtain CaYAlO4:Ce. 3+ fluorescent powder, Figure 1 In this embodiment, CaYAlO4:1.0%Ce 3+ The XRD pattern of the powder was obtained; the powder was passed through a 200-mesh sieve, pressed into sheets under 6 tons of pressure, and sintered at 1500℃ for 6 hours to obtain ceramic samples. Figure 4 The density is 98 g / cm³. 3 .

[0025] The sample exhibited blue light emission centered at 430 nm under 400 nm excitation (as measured by an FLS1000 spectrometer). Figure 2 ), corresponding to the traditional Ca site Ce 3+ Center; Y position Ce in CYA 3+ The center has a low proportion of radiation and the orange light emission has not been effectively activated.

[0026] Example 2: CaYAlO4:1.0%Ce 3+ Preparation of 5%Sc orange light emitting sample Unlike Example 1, in this example, CaCO3, Y2O3, Al2O3, Sc2O3, and CeO2 were weighed as raw materials according to a Ca:Y:Al:Sc:Ce molar ratio of 1:0.99:0.95:0.05:0.01. An appropriate amount of anhydrous ethanol was added, and the mixture was ground and mixed. After drying, the mixture was pre-calcined in a high-temperature furnace and then finely ground to obtain CaYAlO4:1.0%Ce. 3+ 5%Sc fluorescent powder. The powder was pressed into sheets and sintered to obtain a ceramic sample with a density of 98 g / cm³. 3 .

[0027] Example 3: CaYAlO4:1.0%Ce 3+ Preparation of 10%Sc orange light emission samples Unlike Example 1, in this example, CaCO3, Y2O3, Al2O3, Sc2O3, and CeO2 were weighed as raw materials according to a Ca:Y:Al:Sc:Ce molar ratio of 1:0.99:0.90:0.10:0.01. An appropriate amount of anhydrous ethanol was added, and the mixture was ground and mixed. After drying, the mixture was pre-calcined in a high-temperature furnace and then finely ground to obtain CaYAlO4:1.0%Ce. 3+ 10%Sc fluorescent powder. The powder was pressed into sheets and sintered to obtain ceramic samples. Figure 4 ).

[0028] Example 4: CaYAlO4:1.0%Ce 3+ Preparation of 15%Sc orange light emitting sample Unlike Example 1, in this example, CaCO3, Y2O3, Al2O3, Sc2O3, and CeO2 were weighed as raw materials according to a Ca:Y:Al:Sc:Ce molar ratio of 1:0.99:0.85:0.15:0.01. An appropriate amount of anhydrous ethanol was added, and the mixture was ground and mixed. After drying, the mixture was pre-calcined in a high-temperature furnace and then finely ground to obtain CaYAlO4:1.0%Ce. 3+ 15%Sc fluorescent powder. The powder was pressed into sheets and sintered to obtain ceramic samples.

[0029] Example 5: CaYAlO4:1.0%Ce 3+ Preparation of 20%Sc orange light emission samples Unlike Example 1, in this example, CaCO3, Y2O3, Al2O3, Sc2O3, and CeO2 were weighed as raw materials according to a Ca:Y:Al:Sc:Ce molar ratio of 1:0.99:0.80:0.20:0.01. An appropriate amount of anhydrous ethanol was added, and the mixture was ground and mixed. After drying, the mixture was pre-calcined in a high-temperature furnace and then finely ground to obtain CaYAlO4:1.0%Ce. 3+ 20%Sc phosphor powder Figure 1In this embodiment, CaYAlO4:1.0%Ce 3+ XRD pattern of 20%Sc. The powder was pressed into sheets and sintered to obtain ceramic samples. Figure 4 ).

[0030] The sample exhibited orange emission centered at 600 nm under 460 nm excitation, corresponding to Ce at the Y-position. 3+ Light-emitting ( Figure 2 The 600 nm emission lifetime is 23 ns (obtained by measuring with an FLS1000 spectrometer and a nanolaser). Figure 3 ).

[0031] Example 6: CaYAlO4:1.0%Ce 3+ Preparation of orange light emitting samples with 20%Sc and 5%Si Unlike Example 1, in this example, CaCO3, Y2O3, Al2O3, Sc2O3, SiO2, and CeO2 were weighed as raw materials according to a Ca:Y:Al:Sc:Si:Ce molar ratio of 1:0.99:0.75:0.20:0.05:0.01. An appropriate amount of anhydrous ethanol was added, and the mixture was ground and mixed. After drying, the mixture was pre-calcined in a high-temperature furnace and then finely ground to obtain CaYAlO4:1.0%Ce. 3+ 10%Sc, 5%Si phosphor Figure 1 In this embodiment, CaYAlO4:1.0%Ce 3+ XRD analysis of 20% Sc and 5% Si. The powder was pressed into sheets and sintered to obtain ceramic samples. Figure 4 ).

[0032] Example 7: CaYAlO4:1.0%Ce 3+ Preparation of orange light emitting samples with 20% Sc and 10% Si Unlike Example 1, in this example, CaCO3, Y2O3, Al2O3, Sc2O3, SiO2, and CeO2 were weighed as raw materials according to a Ca:Y:Al:Sc:Si:Ce molar ratio of 1:0.99:0.70:0.20:0.10:0.01. An appropriate amount of anhydrous ethanol was added, and the mixture was ground and mixed. After drying, the mixture was pre-calcined in a high-temperature furnace and then finely ground to obtain CaYAlO4:1.0%Ce. 3+ 10%Sc, 10%Si phosphor Figure 1 In this embodiment, CaYAlO4:1.0%Ce 3+ XRD analysis of the powder (20% Sc, 10% Si) was performed. The powder was pressed into sheets and sintered to obtain ceramic samples. Figure 4 ).

[0033] The sample exhibited orange light emission centered at 580-600 nm under 460 nm excitation, and the orange light emission gradually increased with increasing Si content up to 0.100. Figure 5 a) Efficiency gradually increased from 5% to 31% (as measured by an FLS1000 spectrometer and integrating sphere). Figure 5 b) Stability from Example 4 CaYAlO4:1.0%Ce 3+ The percentage of 10%Sc increased from 15% to 55% (obtained by testing with an FLS1000 spectrometer and an Oxford cryostat variable-temperature system). Figure 5 c).

[0034] Example 8: Laser Illumination Device Based on CYA Orange Ceramic The CaYAlO4:1.0%Ce obtained in Example 7 was used. 3+ A fluorescent ceramic converter (0.8 cm in diameter and 0.1 cm thick) of 20%Sc and 10%Si is fixedly mounted on a metal heat sink (such as an aluminum heat sink base) to achieve rapid heat conduction and dissipation during operation. Subsequently, this fluorescent ceramic converter is combined sequentially with a 450 nm blue laser (a 450 nm semiconductor laser can be used), a reflector, and a convex lens to form a laser illumination device.

[0035] A blue laser beam strikes a reflector, which then reflects the beam onto a ceramic converter plate. This prevents the laser from directly irradiating the ceramic and causing excessive heat. The ceramic plate converts some of the blue light into orange light, and the remaining blue and orange light are combined by a convex lens to form a directional output beam. The device's output spectrum simultaneously contains a blue emission peak at approximately 450 nm and a broadband orange emission peak at approximately 580 nm. Figure 6 This indicates that the ceramic converter can achieve efficient orange light conversion under blue light excitation. As the laser input power increases, the output light intensity of the device continuously increases. This laser illumination device can produce stable and high-brightness illumination light in nighttime environments. Figure 7 This demonstrates the great potential for high-power laser lighting applications.

[0036] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made by those skilled in the art to the Sc content, Si content, Ce content, sintering method, ceramic thickness, device optical path structure, or heat dissipation structure without departing from the spirit and principle of the present invention should be considered as equivalent substitutions and included within the protection scope of the present invention.

Claims

1. A Ce 3+ Activated CaYAlO4 orange laser ceramic, characterized by: The laser ceramic is based on CaYAlO4 and contains Ce. 3+ It is a luminescence activator and contains substances for regulating Ce. 3+ The Sc element serves as a placeholder; the Sc element partially replaces the Al sites in the AlO6 framework of CaYAlO4, making Ce... 3+ The space is shifted from Ca to Y, thus generating Ce at position Y. 3+ Orange Light Transmission Center.

2. A Ce 3+ Activated CaYAlO4 orange laser ceramic, characterized by: The general chemical formula of the laser ceramic is CaYAl. 1-x Sc x O4:zCe 3+ Where x is the doping concentration of Sc, and z is the doping concentration of Ce. 3+ The doping concentration is 0.02≤x≤0.30, 0.001≤z≤0.10; preferably 0.05≤x≤0.

20.

3. The laser ceramic according to claim 1 or 2, characterized in that: The laser ceramic also contains Si element; Its general chemical formula is CaYAl 1-x-y Sc x Si y O4:zCe 3+ Where y is the doping concentration of Si, 0.02≤x≤0.30, 0.01≤y≤0.15, 0.001≤z≤0.10; preferably x=0.20, y=0.05~0.

10.

4. The laser ceramic according to claim 1 or 2, characterized in that: The Y-position Ce 3+ The luminescence decay lifetime of the orange light emission center is 20–30 ns.

5. The method for preparing the laser ceramic according to claim 1 or 2, characterized in that, The method includes the following steps: Step 1: Weigh the raw materials containing Ca, Y, Al, Ce and Sc according to the molar amounts of each element in the target chemical formula, add anhydrous ethanol or deionized water and mix and grind; wherein the raw materials containing Ca are selected from CaCO3 or CaO, the raw materials containing Y are selected from Y2O3 or Y(NO3)3, the raw materials containing Al are selected from Al2O3, Al(OH)3 or AlF3, the raw materials containing Ce are selected from CeO2 or Ce(NO3)3, and the raw materials containing Sc are selected from Sc2O3; Step 2: Dry the mixture at 80–120 °C; then pre-calcine it at 1000–1550 °C for 2–10 hours to obtain fluorescent powder; Step 3: Grind the powder into a fine powder, sieve it, press it into tablets or isostatically press it into shape, and sinter it at 1400-1700 ℃ for 1-10 hours to obtain dense fluorescent ceramics; finally, cut, grind and polish it to obtain laser ceramic sheets that can be used for laser lighting.

6. The preparation method according to claim 5, characterized in that, In step 1, the raw materials containing Ca, Y, Al, Ce and Sc are weighed according to the molar amounts of each element in the target chemical formula, and mixed and ground with anhydrous ethanol or deionized water; the raw materials containing Si are selected from SiO2.

7. The application of the laser ceramic as described in claim 1 or 2 in the fabrication of laser light-emitting devices.

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