White light emitting phosphor and preparation method and application thereof

Abstract

The present application relates to a kind of white light emitting fluorescent powder and its preparation method and application.The chemical composition formula of the white light emitting fluorescent powder is:Rb 2.99 Y 1‑y (PO4)2:0.01Eu 2+ ,yLa 3+ Wherein 0.003 ≤y ≤ 0.08.The white light emitting fluorescent powder is single matrix fluorescent powder system, the luminous color is in white light area and realizes controllable adjustment, has high internal quantum efficiency and high luminous intensity, good thermal stability, can effectively inhibit the drift of white light color coordinate and related color temperature, and it can be synthesized under the condition of mild reaction condition, low production cost, safe.

Description

Technical Field

[0001] This invention relates to the field of lighting, and more specifically, to a white luminescent phosphor, its preparation method, and its application. Background Technology

[0002] With the rapid development of high-quality solid-state lighting technology, white light-emitting diodes (WLEDs) have become an important light source in the current lighting field due to their advantages such as high energy efficiency, long lifespan, and environmental friendliness. Among them, white LED technology based on near-ultraviolet (n-UV) chip-excited phosphors can achieve a wide spectral coverage and a high color rendering index, showing significant application potential in health lighting and high-end lighting. In existing n-UV-excited white LED technologies, red, green, and blue phosphors are generally mixed to form white light output. However, this approach suffers from problems such as difficulty in adjusting the phosphor mixing ratio, inconsistent luminous decay among phosphors, spectral overlap, and reabsorption, resulting in energy loss and increasing the complexity of the packaging process, thus limiting its further application in high-reliability and high-consistency lighting fields. To address these issues, single-matrix white light-emitting phosphors have gradually attracted attention in recent years. These phosphors typically achieve coordinated emission or ultra-wideband emission from multiple luminescent centers within the same crystal structure, ensuring that white light output originates from a unified luminescent system. This inherently avoids the aging inconsistencies and reabsorption problems present in multi-phosphor systems, and offers advantages such as simple structure, high color stability, user-friendly encapsulation process, and excellent long-term reliability.

[0003] For example, Ming Zhao et al. (DOI: 10.1002 / adfm.202412480) in Eu 2+ In a multi-site Rb3Y(PO4)2-based phosphor system, a "carbon-hydrogen co-reduction" strategy is employed to promote Eu... 2+ By occupying the Y sites (excluding Rb sites), the light color can be gradually adjusted from blue-violet to white to yellow. However, this method requires a synthesis temperature as high as 1300℃, demanding sophisticated equipment and consuming significant energy. Furthermore, the calcination process necessitates the use of expensive graphite crucibles and is conducted under a hydrogen atmosphere with a volume fraction as high as 20%, making the synthesis conditions harsh and posing certain safety risks. Therefore, providing phosphors with tunable luminescence and white light emission from a single matrix while reducing synthesis temperature and energy consumption, lowering experimental equipment costs, and improving experimental safety is a pressing technical challenge. Summary of the Invention

[0004] The primary objective of this invention is to overcome the problems of high equipment requirements, high energy consumption, and harsh synthesis conditions required for the preparation of single-matrix white luminescent phosphors, and to provide a white luminescent phosphor. This white luminescent phosphor material is a single-matrix phosphor system, its emission color is within the white light region and can be controllably adjusted, it possesses high internal quantum efficiency and high luminous intensity, good thermal stability, can effectively suppress the drift of white light color coordinates and correlated color temperature, and can be synthesized under mild reaction conditions, low production costs, and safety.

[0005] A further objective of this invention is to provide a method for preparing white luminescent phosphor.

[0006] Another object of the present invention is to provide an application of the above-mentioned white luminescent phosphor in the field of lighting.

[0007] The above-mentioned objective of the present invention is achieved through the following technical solution:

[0008] A white luminescent phosphor, wherein the chemical formula of the white luminescent phosphor is: Rb 2.99 Y 1-y (PO4)2:0.01Eu 2+ yLa 3+ , where 0.003 ≤ y ≤ 0.08.

[0009] La 3+ It belongs to the category of inert rare-earth modulating ions, and its introduction into phosphors is solely as a modulating ion. The inventors of this invention discovered that in Rb... 2.99 Y 1-y (PO4)2:0.01Eu 2+ Introducing a specific amount of La 3+ This helps to change the local structural environment of the matrix lattice, La 3+ Replace the smaller radius Y³ + Upon entering the crystal lattice, it causes the corresponding coordination polyhedron to expand, thereby making Eu² + The occupancy ratio of different lattice sites varies in the same matrix, and Eu² + The change in the intensity of the crystal field ultimately manifests as multiple emission peaks emitting light collaboratively without introducing additional luminescent centers, thereby achieving controllable adjustment of the emitted color within the white light region.

[0010] In addition, La with a larger radius 3+ The introduction of ions promotes overall expansion of the unit cell, which is beneficial for the divalent Eu luminescent center to enter the lattice and exist stably; on the other hand, an appropriate amount of inert La ions... 3+ The introduction of [the substance] effectively increases the Eu–Eu spacing and reduces the concentration quenching effect, thereby improving the internal quantum efficiency and luminescence intensity of the white luminescent phosphor.

[0011] If other inert rare earth modulating ions are introduced (e.g., Sc), 3+ and Lu 3+ If the phosphor is not properly luminescent, it cannot achieve white emission, and the internal quantum efficiency and luminescence intensity cannot be effectively improved.

[0012] Furthermore, the white luminescent phosphor of this invention exhibits good thermal stability and high integrated luminescence intensity in the range of 300-400 K. Moreover, this white luminescent phosphor is a single-matrix phosphor system with a simple structure. When used for packaging white light devices, it avoids the proportion control and reabsorption problems caused by mixing multi-color phosphors, resulting in consistent thermal quenching and aging behavior. This is beneficial for improving device consistency and reliability, as well as effectively suppressing the drift of white light color coordinates and correlated color temperature.

[0013] In addition, due to La 3+ With the introduction of this invention, the white luminescent phosphor material of the present invention can be synthesized at a lower temperature (e.g., 950~1050℃), a lower hydrogen concentration (e.g., 3%~8% H2), and in a conventional reaction apparatus (e.g., corundum crucible), resulting in low energy consumption, mild reaction conditions, low production costs, and a safe preparation process.

[0014] The white luminescent phosphor material of the present invention is a single-matrix phosphor system, the luminescent color is within the white light region and can be controllably adjusted, it has high internal quantum efficiency and high luminescence intensity, good thermal stability, can effectively suppress the drift of white light color coordinates and correlated color temperature, and it can be synthesized under mild reaction conditions, low production cost and safe conditions.

[0015] Preferably, 0.003 ≤ y ≤ 0.02.

[0016] When the γ is adjusted within this range, white phosphors can achieve low color temperature and high color rendering, exhibiting warm white light characteristics, thus not only meeting the requirements of white light illumination but also the requirements of healthy lighting.

[0017] Preferably, 0.007 ≤ y ≤ 0.08.

[0018] More preferably, 0.01 ≤ y ≤ 0.08.

[0019] More preferably, 0.02 ≤ y ≤ 0.08.

[0020] More preferably, 0.04 ≤ y ≤ 0.08.

[0021] Within the above range, the internal quantum efficiency and luminescence intensity of white phosphors are both higher when γ is regulated.

[0022] The preparation method of the above-mentioned white luminescent phosphor includes the following steps: S1. Mix europium source, rubidium source, yttrium source, phosphorus source and lanthanum source in proportion, add grinding aid and grind; S2. The mixture is calcined in a reducing atmosphere to obtain the white luminescent phosphor.

[0023] Preferably, in step S1, the europium source is Eu2O3.

[0024] Preferably, in step S1, the rubidium source is Rb₂CO. 3。

[0025] Preferably, in step S1, the yttrium source is Y2O3.

[0026] Preferably, in step S1, the phosphorus source is at least one of NH4H2PO4 or (NH4)2HPO4.

[0027] Preferably, in step S1, the lanthanum source is La2O3.

[0028] Preferably, in step S1, the molar ratio of europium in the europium source, rubidium in the rubidium source, yttrium in the yttrium source, phosphorus in the phosphorus source, and lanthanum in the lanthanum source is 0.01:2.99:(0.920~0.997):2:(0.003~0.08).

[0029] More preferably, the molar ratio of europium in the europium source, rubidium in the rubidium source, yttrium in the yttrium source, phosphorus in the phosphorus source, and lanthanum in the lanthanum source is 0.01:2.99:(0.980~0.997):2:(0.003~0.02), which meets the requirements for healthy lighting.

[0030] More preferably, the molar ratio of europium in the europium source, rubidium in the rubidium source, yttrium in the yttrium source, phosphorus in the phosphorus source, and lanthanum in the lanthanum source is 0.01:2.99:(0.920~0.993):2:(0.007~0.08).

[0031] Specifically, in step S1, the phosphorus source is NH4H2PO, and the mass ratio of the europium source, rubidium source, yttrium source, phosphorus source, and lanthanum source is 0.0058:1.1394:(0.3428~0.3715):0.7592:(0.0016~0.0430).

[0032] Preferably, the grinding aid in step S2 is at least one of anhydrous ethanol or acetone.

[0033] More preferably, the grinding aid in step S2 is anhydrous ethanol.

[0034] Preferably, the calcination temperature in step S2 is 950~1050 ℃.

[0035] More preferably, the calcination temperature in step S2 is 1000°C.

[0036] Preferably, the calcination time in step S2 is 11-13 h.

[0037] More preferably, the calcination time in step S2 is 10 hours.

[0038] Preferably, the reducing atmosphere in step S2 is a mixture of hydrogen and nitrogen, wherein the volume ratio of hydrogen to nitrogen is (3~8):(97~92).

[0039] More preferably, the reducing atmosphere in step S2 is a mixture of hydrogen and nitrogen, wherein the volume ratio of hydrogen to nitrogen is 5:95.

[0040] Preferably, the crucible material in step S2 is a corundum crucible.

[0041] This invention particularly protects the application of the above-mentioned white luminescent phosphor in the field of lighting.

[0042] Preferably, the illumination is white light illumination.

[0043] More preferably, the white light illumination is healthy lighting.

[0044] Preferably, the white luminescent phosphor is used in LEDs.

[0045] More preferably, the LED is a white light-emitting diode device based on a semiconductor chip.

[0046] Compared with the prior art, the beneficial effects of the present invention are: The white luminescent phosphor material of this invention is a single-matrix phosphor system, the luminescent color is within the white light region and can be controllably adjusted, it has high internal quantum efficiency and high luminescence intensity, good thermal stability, can effectively suppress the drift of white light color coordinates and correlated color temperature, and it can be synthesized under mild reaction conditions, low production cost and safe conditions. Attached Figure Description

[0047] Figure 1 The X-ray diffraction patterns are of the phosphors prepared in Examples 1-6 and Comparative Examples 1-5.

[0048] Figure 2 The room temperature excitation spectra (monitoring wavelength 560 nm) and emission spectra (excitation wavelength 325 nm) of the phosphors prepared in Examples 1-6 and Comparative Example 1 are shown.

[0049] Figure 3The normalized emission spectra of the white luminescent phosphors prepared in Examples 1-6 under 325 nm light excitation are shown.

[0050] Figure 4 The images show the emission spectra of the phosphors prepared in Example 1 and Comparative Examples 1-5 under 325 nm light excitation, with the inset showing the emission integral intensity.

[0051] Figure 5 The excitation / emission spectrum of the white luminescent phosphor in Example 1 (the inset is a picture of the actual object) and its color coordinates / color temperature / display index are shown.

[0052] Figure 6 This is a normalized curve of the integral luminescence intensity of the white phosphor in Example 1 as a function of temperature in the range of 300~450K. Detailed Implementation

[0053] To more clearly and completely describe the technical solution of the present invention, the present invention is further described in detail below through specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention. Various modifications can be made within the scope of the claims of the present invention. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in this technical field. Unless otherwise specified, the reagents and materials used in the present invention are all commercially available.

[0054] Example 1 This embodiment provides a white luminescent phosphor with the chemical formula Rb. 2.99 Y 1-y (PO4)2:0.01Eu 2+ yLa 3+ , where y = 0.007; its preparation method includes the following steps: S1. La is co-doped at a ratio of y=0.007. 3+ Weigh out each raw material, and the molar ratio of the corresponding elements is Rb:Y:P:Eu:La=2.99:0.993:2:0.01:0.007. The weighing amounts of each raw material are shown in Table 1. Grind the raw materials accurately weighed according to Table 1 in an agate mortar with anhydrous ethanol until homogeneous to obtain a mixture.

[0055] Table 1. Raw material composition of phosphor in Example 1

[0056] S2. Transfer the above uniformly mixed mixture into a corundum crucible and place it in a tube furnace at 5% H₂. 2-The sample was heated from 30 °C to 1000 °C in a reducing atmosphere of 95% N2 mixed gas for 194 minutes, held at that temperature for 10 h, and then naturally cooled to room temperature. After the sample was removed, it was thoroughly ground into powder to obtain white luminescent phosphor.

[0057] Example 2 This embodiment is a second embodiment of a white luminescent phosphor of the present invention, which differs from Embodiment 1 in that: y=0.003.

[0058] The preparation method of the white luminescent phosphor in this embodiment differs from that in Example 1 in that the amount of raw materials weighed is shown in Table 2. Table 2. Raw material composition of phosphor in Example 2

[0059] Example 3 This embodiment is the third embodiment of a white luminescent phosphor of the present invention. The difference from embodiment 1 is that y=0.01.

[0060] The preparation method of the white luminescent phosphor in this embodiment differs from that in Example 1 in that the amount of raw materials weighed is shown in Table 3. Table 3. Raw material composition of phosphor in Example 3

[0061] Example 4 This embodiment is the fourth embodiment of a white luminescent phosphor of the present invention, which differs from Embodiment 1 in that: y=0.02.

[0062] The preparation method of the white luminescent phosphor in this embodiment differs from that in Example 1 in that the amount of raw materials weighed is shown in Table 4. Table 4. Raw material composition of phosphor in Example 4

[0063] Example 5 This embodiment is the fifth embodiment of a white luminescent phosphor of the present invention. The difference from embodiment 1 is that y=0.04.

[0064] The preparation method of the white luminescent phosphor in this embodiment differs from that in Example 1 in that the amount of raw materials weighed is shown in Table 5. Table 5. Raw material composition of phosphor in Example 5

[0065] Example 6 This embodiment is the sixth embodiment of a white luminescent phosphor of the present invention. The difference from embodiment 1 is that y=0.08.

[0066] The preparation method of the white luminescent phosphor in this embodiment differs from that in Example 1 in that the amount of raw materials weighed is shown in Table 6. Table 6. Raw material composition of phosphor in Example 6

[0067] Example 7 This embodiment is the seventh embodiment of a white luminescent phosphor of the present invention, and its chemical composition is the same as that of Embodiment 1.

[0068] The preparation method of the white luminescent phosphor in this embodiment differs from that in Example 1 in that: in step S2, the volume ratio of hydrogen to nitrogen in the mixed gas is 3%H. 2- 97% N2, the insulation temperature is 950℃.

[0069] Comparative Example 1 This comparative example provides a phosphor that differs from Example 1 in that y=0.

[0070] The preparation method of the phosphor in this comparative example differs from that in Example 1 in that the amount of raw materials weighed is shown in Table 7. Table 7 Raw material composition of phosphor in Comparative Example 1

[0071] Comparative Example 2 This comparative example provides a phosphor that differs from Example 1 in that its chemical formula is Rb. 2.99 Y 1-y (PO4)2:0.01Eu 2+ ySc 3+ , where y=0.007.

[0072] The preparation method of the phosphor in this comparative example differs from that in Example 1 in that some of the raw materials and their weighing amounts are shown in Table 8: Table 8. Raw material composition of phosphor in Comparative Example 2

[0073] Comparative Example 3 This comparative example provides a phosphor that differs from Example 1 in that its chemical formula is Rb. 2.99 Y 1-y (PO4)2:0.01Eu 2+ yLu 3+ , where y=0.007.

[0074] The preparation method of the phosphor in this comparative example differs from that in Example 1 in that some of the raw materials and their weighing amounts are shown in Table 9: Table 9. Raw material composition of phosphor in Comparative Example 3

[0075] Comparative Example 4 This comparative example provides a phosphor that differs from Example 1 in that it uses only 0.008% Eu as the luminescent center, following the formulation in the literature (DOI: 10.1002 / adfm.202412480), without deducting the corresponding proportion of Rb raw material, and without introducing additional inert rare earth ions. The chemical composition of this phosphor is Rb3Y(PO4)2:0.08Eu. 2+ .

[0076] The preparation method of the phosphor in this comparative example differs from that in Example 1 in that some of the raw materials and their weighing amounts are shown in Table 10: Table 10 Raw material composition of phosphor in Comparative Example 4

[0077] Comparative Example 5 This comparative example provides a phosphor that differs from Example 1 in that y = 0.2.

[0078] The preparation method of the phosphor in this comparative example differs from that in Example 1 in that the amount of raw materials weighed is shown in Table 11: Table 11 Raw material composition of phosphor in Comparative Example 5

[0079] Performance testing 1. Luminous properties Table 12. Color coordinates, correlated color temperature, color rendering index, and emission color of the phosphors in Examples 1-6 and Comparative Examples 1-5.

[0080] Table 13. Integrated intensity, internal quantum efficiency, and peak position of the emission bands of the phosphors prepared in Examples 1-6 and Comparative Examples 1-5 under 325 nm photoexcitation.

[0081] Examples 1-6 and Comparative Examples 1-5 were characterized by X-ray diffraction (XRD), and the results are as follows: Figure 1 As shown. From Figure 1 The XRD patterns show that, compared with the standard card ICSD#47361 (Rb3Y(PO4)2), the XRD diffraction peaks of the phosphors in each example and comparative example are basically consistent with the standard card, and no obvious impurity phase diffraction peaks were observed, indicating that structurally stable single-phase phosphor samples were successfully prepared within the stated composition range.

[0082] The photoluminescence properties of the phosphors from Examples 1-6 and Comparative Examples 1-5 were tested, and the results are as follows: Figures 2-3 As shown in Tables 12 and 13. Figure 2 The room temperature excitation spectra (monitoring wavelength 560 nm) and emission spectra (excitation wavelength 325 nm) of the phosphors prepared in Examples 1-6 and Comparative Example 1 are shown. Figure 3 Table 12 shows the normalized emission spectra of the white luminescent phosphors prepared in Examples 1-6 under 325 nm light excitation. Table 13 shows the color coordinates, correlated color temperature, color rendering index, and emission color of the phosphors in Examples 1-6 and Comparative Examples 1-5 under 325 nm light excitation. Table 14 shows the integrated intensity, internal quantum efficiency, and peak position of the emission bands of the phosphors prepared in Examples 1-6 and Comparative Examples 1-5 under 325 nm light excitation. Figures 2-3 And Tables 12-13, under near-ultraviolet light excitation at 325 nm, compared with Eu²-doped only + Compared to Comparative Example 1, with La 3+ With the gradual increase of co-doping concentration, the emission peak intensities at approximately 425 nm and 710 nm in each embodiment showed a regular decrease, while the peak position of the emission peak in the middle position continuously blue-shifted from 582 nm to 555 nm. Therefore, this invention achieves controllable adjustment of the color temperature from 4678 K to 4026 K and the emission color from "cool white light → warm white light" and stable white light output without introducing additional luminescent centers and under mild reduction synthesis conditions. The aforementioned changes in luminescence behavior mainly originate from La³⁺. + Co-doping with Eu² + Effective regulation of the occupancy ratio of different cation sites in the matrix. With the development of La 3+ With increasing content, La³⁺, with its larger ionic radius, + Replace the smaller radius Y³ + Upon entering the crystal lattice, it causes an overall expansion of the unit cell volume, resulting in the Eu peak corresponding to the emission peak at the intermediate position being affected. 2+ The corresponding expansion of the occupied polyhedron makes the Eu² + The crystal field strength weakens, thus causing Eu² + The 5d level splitting is reduced, ultimately resulting in a blue shift of the emission peak. Therefore, compared with Comparative Examples 1-4, all embodiments achieved white emission, demonstrating high application value.

[0083] As shown in Table 12, the color rendering index R of the white luminescent phosphors in Examples 1-6 is... a The color rendering index (CRI) is 72.82~83.99, and the color temperature is 4026~4678 K, meeting the comprehensive requirements for white light illumination. Meanwhile, the CRIs of comparative examples 2~5 are... a With a range of 48.22 to 70.03 and a color temperature of 5770 to 20154 K, it is difficult to meet the application requirements of white light lighting.

[0084] As can be seen from Table 13, only Eu doping 2+ The comparative example 1 has an internal quantum efficiency of only 58.5%, compared to that of Eu-doped samples. 2+ Compared to Comparative Example 1, introducing an appropriate amount of La³ into the matrix + Subsequently, the emission integral intensity and internal quantum efficiency of the white luminescent phosphor in each embodiment both increased with La³ + The internal quantum efficiency of the phosphor increased significantly with increasing concentration. Examples 1-6 ranged from 67.4% to 93.1%, with Example 6 exhibiting the highest luminescence efficiency, significantly increasing from 58.5% in Comparative Example 1 to 93.1%. Furthermore, the phosphor in Example 1 also showed an internal quantum efficiency as high as 74.2%, demonstrating excellent luminescence performance. In contrast, the undoped La... 3+ The quantum efficiency of comparative examples 2-4 phosphors, which were co-doped with other inert rare-earth modulating ions, was only around 60%, significantly lower than the luminescence performance of the examples. By co-doping with La... 3+ The enhanced luminescence phenomenon may be attributed to the following synergistic effect: on the one hand, La³ + The introduction of this ion promotes the overall expansion of the unit cell, which is beneficial for the stable entry of the luminescent center Eu into the lattice; on the other hand, an appropriate amount of inert modulator ions La³⁺ + The introduction of La effectively increased the Eu–Eu spacing, reduced the concentration quenching effect, and thus further enhanced the luminescence intensity. It is worth noting that when La… 3+ When the concentration was increased to 0.2, the luminescence intensity of the phosphor in Comparative Example 5 decreased significantly, with a quantum efficiency of 78%. Furthermore, this high-La... 3+ The optimal peak position of the concentration comparison sample 5 is at 531 nm, with color coordinates of (0.3251, 0.4242), exhibiting green light emission, which is significantly deviated from the white light region, as shown in Table 12.

[0085] The luminescence performance of Example 1 and Comparative Examples 1-5 was further tested. Figure 4 The images show the emission spectra of the phosphors prepared in Example 1 and Comparative Examples 1-5 under 325 nm light excitation, with the inset showing the emission integral intensity. Figure 5 The excitation / emission spectrum (inset is a photograph of the actual product) of the white luminescent phosphor in Example 1 is shown, along with its color coordinates / color temperature / color index. Because La... 3+ Co-doping promotes Eu² + In the matrix, different lattice sites exhibit a preferential occupancy tendency. Each embodiment, through the synergistic effect of multi-lattice site occupancy emission at a single luminescent center, achieves white light emission with high application value. Therefore, compared to Eu²⁺-doped light... + Compared to Comparative Example 1, which emitted purplish-red light, all embodiments achieved white light emission, demonstrating higher application value. Figures 4-5It can be seen that the color coordinates of the white luminescent phosphor in Example 1 are (0.3749, 0.3699), which are close to the ideal white light coordinates (0.333, 0.333). Its correlated color temperature (CCT) is 4104 K (<4500 K), exhibiting warm white light characteristics, and the color rendering index (R) is [missing information]. a Reaching 81.28 (>75), it not only meets the requirements for white light illumination but also the comprehensive requirements for low color temperature and high color rendering index for healthy lighting. Similarly, Examples 2-4 also simultaneously meet the requirements for both white light illumination and healthy lighting. (The text then abruptly shifts to a seemingly unrelated topic about co-doped rare earth element La³⁺.) + Compared to Example 1, co-doped Sc³ + Comparative Example 2 and co-doped Lu³ + The emission spectrum peak shape and intensity of Comparative Example 3 are similar to those of Eu²⁺-doped samples. + The comparison example is basically the same, with the emitted light still being purplish-red and weak in intensity, limiting its application value; meanwhile, Sc³ + and Lu³ + The high price further highlights the choice of La³ + The phosphor demonstrates cost advantages and practical prospects for regulating ions. Comparative Example 4 is a phosphor prepared under mild reduction conditions with a lower synthesis temperature and lower hydrogen gas integral, according to the formulation of the white light sample reported in the literature (DOI: 10.1002 / adfm.202412480). It is based on the same formulation as the examples. Figure 4 As can be seen, the emission spectrum peak shape and emission color of Comparative Example 4 are still similar to those of Comparative Example 1, exhibiting weak violet-red light and failing to achieve white light emission. Further analysis reveals that the white light sample in the literature needs to be synthesized at a high temperature of up to 1300℃, and the calcination process needs to be completed in a hydrogen atmosphere with a volume fraction of 20% using an expensive graphite crucible. The synthesis conditions are harsh, energy consumption is high, and there are certain safety hazards.

[0086] The properties of the white luminescent phosphor in Example 7 are similar to those in Example 1.

[0087] 2. Thermal stability performance Figure 6 This is the normalized result of the integral intensity of the emission spectrum of the white phosphor in Example 1 as a function of temperature within the temperature range of 300~450 K. Luminescent thermal stability is an important indicator for evaluating the performance of phosphors in practical applications of white LEDs. For example... Figure 6 As shown, although the integrated luminescence intensity of the white phosphor gradually decreases with increasing temperature, it can still maintain 80.7% of that at 300 K (25℃) at 400 K (125℃), indicating that the white phosphor has excellent thermal stability and can meet the operating temperature requirements of white LED devices.

[0088] The above performance test parameters indicate that this single-matrix white luminescent phosphor can be used to prepare high-performance white LEDs that meet the requirements of white light illumination, and has good application prospects.

[0089] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A white luminescent phosphor, characterized in that, The chemical formula of the white luminescent phosphor is: Rb 2.99 Y 1-y (PO4)2:0.01Eu 2+ yLa 3+ , where 0.003 ≤ y ≤ 0.

08.

2. The white luminescent phosphor according to claim 1, characterized in that, 0.003 ≤y ≤ 0.02。 3. The white luminescent phosphor according to claim 1, characterized in that, 0.007 ≤y ≤ 0.08。 4. A method for preparing the white luminescent phosphor according to any one of claims 1 to 3, characterized in that, Includes the following steps: S1. Mix europium source, rubidium source, yttrium source, phosphorus source and lanthanum source in a certain proportion, add grinding aid and grind to obtain a mixture; S2. The mixture is calcined in a reducing atmosphere to obtain the white luminescent phosphor.

5. The preparation method according to claim 4, characterized in that, The molar ratio of europium in the europium source, rubidium in the rubidium source, yttrium in the yttrium source, phosphorus in the phosphorus source, and lanthanum in the lanthanum source in step S1 is 0.01:2.99:(0.92~0.997):2:(0.003~0.08).

6. The preparation method according to claim 4, characterized in that, The calcination temperature in step S2 is 950~1050℃.

7. The preparation method according to claim 4, characterized in that, The calcination time in step S2 is 11-13 hours.

8. The preparation method according to claim 4, characterized in that, The reducing atmosphere in step S2 is a mixture of hydrogen and nitrogen, with a volume ratio of (3~8):(97~92).

9. The preparation method according to claim 4, characterized in that, The calcination in step S2 is carried out in a crucible made of corundum.

10. The application of the white luminescent phosphor according to claims 1 to 3 in the field of lighting.

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