Dysprosium-doped barium borate yellow fluorescent powder as well as preparation method and application thereof
By preparing dysprosium-doped barium borate yellow phosphor Ba3-xB2O6:xDy3+, and combining it with nitride red phosphor and ultraviolet LED chips, the problem of insufficient cyan region of existing yellow phosphors under blue light excitation was solved, achieving a warm white LED effect with high color temperature and high color rendering index.
Patent Information
- Application Number
- CN202510870735.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-26
- Publication Date
- 2025-10-31
AI Technical Summary
Existing commercial yellow phosphors lack a cyan region when excited by blue light, which limits their application in high-quality lighting and poses a blue light hazard.
A dysprosium-doped barium borate yellow phosphor, Ba3-xB2O6:xDy3+, was prepared using a high-temperature solid-state method. Combined with nitride red phosphor and ultraviolet LED chips, a warm white LED with high color temperature and high color rendering index was fabricated.
It overcomes the problem of insufficient cyan region in commercial yellow phosphors under blue light excitation, reduces blue light hazards, and achieves efficient warm white LED luminescence.
Smart Images
Figure CN120865902A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of luminescent materials technology, specifically relating to a dysprosium-doped barium borate yellow phosphor, its preparation method, and its application. Background Technology
[0002] In recent years, various types of yellow phosphors have been reported, with oxynitrides, silicates, and aluminates being widely studied matrices and attracting increasing attention. However, the preparation and application of borate phosphors are still rarely reported. Among them, phosphors based on borate matrices are considered one of the ideal candidates for phosphor matrices due to their unique crystal structure and excellent physicochemical properties. Borates possess rigid lattices, low vibrational energy, and good thermal stability, which can effectively reduce non-radiative transitions and improve the luminescence efficiency of rare-earth ions, attracting the attention of many researchers.
[0003] Light-emitting diodes (LEDs) are hailed as the fourth generation of green and environmentally friendly lighting sources, boasting advantages such as energy saving, environmental friendliness, long lifespan, and low heat generation. They have garnered widespread attention and are increasingly used in practical applications. Currently, one common method for achieving white LEDs in commercial applications is to mix yellow phosphors and blue chips to achieve white light emission. However, these commercially available yellow phosphors lack the cyan region under blue excitation, limiting their application in high-quality lighting. Furthermore, this method carries the risk of blue light pollution. Therefore, designing and developing novel, highly efficient yellow phosphors is crucial. Summary of the Invention
[0004] To address or partially address the problems existing in related technologies, this invention provides a dysprosium-doped barium borate yellow phosphor, its preparation method, and its application.
[0005] This invention provides a dysprosium-doped barium borate yellow phosphor, with the chemical formula Ba. (3-x) B2O6:xDy 3+ , of which 0.01 <x<0.1。
[0006] A method for preparing a dysprosium-doped barium borate yellow phosphor includes the following steps: S1. Take photos (3-x) B2O6:xDy 3+ The stoichiometric ratio of each element in the mixture was determined by weighing out the barium source powder, boron source powder, and dysprosium source powder, grinding and mixing them evenly to form a mixture. S2. The mixture prepared in step S1 is pre-sintered, then cooled to room temperature and ground and mixed evenly. S3. The grinding product obtained in step S2 is calcined. After the calcined product is cooled to room temperature, it is ground evenly to obtain dysprosium-doped barium borate yellow phosphor.
[0007] Preferably, the barium source is at least one selected from barium carbonate, barium hydroxide, barium chloride, barium nitrate, barium sulfate, and barium phosphate; the boron source is boric acid, boron trioxide, or elemental boron; and the dysprosium source is at least one selected from dysprosium oxide, dysprosium nitrate, and dysprosium carbonate.
[0008] Preferably, the pre-sintering temperature is 300-700℃ and the pre-sintering time is 2-8 h.
[0009] Preferably, the sintering temperature is 800-1200℃ and the calcination time is 2-10 h.
[0010] This invention also claims protection for the application of the dysprosium-doped barium borate yellow phosphor in warm white LED lighting, specifically including: Dysprosium-doped barium borate yellow phosphor was mixed with commercially available CaAlSiN3:Eu 2+ (Main peak 630nm, Intematix Co., Ltd.) are mixed evenly at a mass ratio of 10:1, coated onto LED chips with UV-curable adhesive, and after curing, phosphor-converted light-emitting diode devices are obtained.
[0011] The technical solution provided by this invention has the following beneficial effects: This invention uses Ba3B2O6 as a matrix and successfully prepares a series of Dy at different concentrations via a high-temperature solid-state method. 3+ Doped yellow phosphor Ba3B2O6:xDy 3+ x = 0.01–0.10. The prepared Dy 3+ The doped yellow phosphor is combined with nitride red phosphor (CaAlSiN3:Eu) 2+ A warm white LED with high color temperature and high color rendering index was prepared using ultraviolet LED chips (365-375nm) and a main peak of 630nm. This can overcome the shortcomings of commercial yellow phosphors, such as the lack of cyan region under blue excitation and the hazard of blue light. Attached Figure Description
[0012] Figure 1 This is a flowchart illustrating the preparation process of the dysprosium-doped barium borate yellow phosphor of this invention.
[0013] Figure 2 The images show the XRD patterns of the materials prepared in Examples 1-5 and Comparative Example 1.
[0014] Figure 3 The images show the excitation and emission spectra of the materials prepared in Examples 1-5, where a is the excitation spectrum and b is the emission spectrum.
[0015] Figure 4The images show the SEM image and particle size distribution of the yellow phosphor in Example 1. Image a is the SEM image, and image b is the particle size distribution.
[0016] Figure 5 This is a CIE coordinate diagram of the yellow phosphor in Examples 1-5.
[0017] Figure 6 The image shows a physical picture and an electroluminescence characteristic diagram of the yellow phosphor encapsulated into an LED in Example 1.
[0018] Figure 7 The images show the excitation and emission spectra of the materials prepared in Examples 3 and Comparative Examples 2-4. a is the excitation spectrum, b is the emission spectrum, c is the CIE coordinate of the phosphor prepared with the magnesium borate matrix in Comparative Example 3, and c is the CIE coordinate of the phosphor prepared with the strontium borate matrix in Comparative Example 4. Detailed Implementation
[0019] Example 1 like Figure 1 A method for preparing a dysprosium-doped barium borate yellow phosphor includes the following steps: S1, according to the chemical formula Ba 3-x B2O6: xDy 3+ The stoichiometric ratio of each element is taken as x=0.04. Barium carbonate powder, boric acid powder and dysprosium trioxide powder are weighed separately, ground and mixed evenly to form a mixture.
[0020] S2. Pre-sinter the mixture prepared in step S1.
[0021] The pre-sintering temperature is 600℃ and the pre-sintering time is 5 h.
[0022] S3. Cool the sintered product obtained in step S2 to room temperature and grind and mix it evenly.
[0023] S4. Calcine the grinding product obtained in step S3.
[0024] The calcination temperature was 950℃ and the calcination time was 5 h.
[0025] S5. After cooling the calcined product obtained in step S4 to room temperature, grind it evenly to obtain a dysprosium-doped yellow phosphor luminescent material with barium borate as the matrix.
[0026] Example 2 The difference between this embodiment of the preparation method of dysprosium-doped barium borate yellow phosphor and Embodiment 1 is that in step S1, x = 0.01.
[0027] Example 3 The difference between this embodiment of the preparation method of dysprosium-doped barium borate yellow phosphor and Embodiment 1 is that in step S1, x = 0.02.
[0028] Example 4 The difference between this embodiment of the preparation method of dysprosium-doped barium borate yellow phosphor and Embodiment 1 is that in step S1, x = 0.07.
[0029] Example 5 The difference between this embodiment of the preparation method of dysprosium-doped barium borate yellow phosphor and Embodiment 1 is that in step S1, x = 0.10.
[0030] Comparative Example 1 The difference between this comparative example and Example 1 is that in step S1, x=0.
[0031] Figure 2 The X-ray diffraction (XRD) patterns of the dysprosium-doped barium borate yellow phosphor and barium borate matrix prepared in Examples 1-5 and Comparative Example 1 are compared with the XRD patterns of the barium borate matrix calculated by the crystal structure visualization software VESTA. It can be seen from the figure that the peak shapes of the pure matrix prepared in Comparative Example 1 and the doped phosphor samples prepared in Examples 1-5 are completely consistent with the calculated peak shapes, and there are no impurity phases.
[0032] Figure 3 a is the excitation spectrum of the dysprosium-doped barium borate yellow phosphor samples in Examples 1-5 at an emission wavelength of 570 nm. Figure 3 b is the emission spectrum of the dysprosium-doped barium borate yellow phosphor samples from Examples 1-5 under monitoring at an excitation wavelength of 350 nm. Figure 3 As can be seen in b, the emission spectra of the dysprosium-doped barium borate yellow phosphor samples in Examples 1-5 show a distinct cyan emission region in the 485-500nm range.
[0033] Figure 4 a is a SEM image of the dysprosium-doped barium borate yellow phosphor sample from Example 1. Figure 4 b is the particle size statistical distribution map corresponding to this SEM image. From Figure 4 As can be seen, the phosphor particles exhibit an irregular polyhedral morphology and a rough surface. Figure 4 b is a histogram of particle size distribution obtained by randomly analyzing the size of 100 particles. The particle diameter is mainly concentrated in the range of 5–17 μm, and the average particle size is 11.22 ± 4.80 μm.
[0034] Figure 5This is a chromaticity coordinate diagram of the emission spectra of the dysprosium-doped barium borate yellow phosphor samples from Examples 1-5, corresponding to their respective CIE 1931 coordinates. The diagram shows that the chromaticity coordinates of the emission spectra of the samples from Examples 1-5 are all located in the yellow region of the CIE 1931 chromaticity diagram (where the x-axis represents the proportion of red in the color, and the y-axis represents the proportion of green). The inset is a magnified view of the chromaticity coordinates, with A, E, and E representing the chromaticity coordinate positions of Examples 1-5, more clearly showing the chromaticity coordinate distribution of samples with different concentrations in Examples 1-5. It is evident that all data points are concentrated in the yellow light region (x≈0.38–0.40, y≈0.40–0.42), indicating that the Ba3B2O6 matrix has good stability for the emission color of Dy³⁺. This characteristic is crucial for the color rendering performance of white LEDs, facilitating the control of the color temperature and color rendering index of white light.
[0035] Comparative Example 2 A method for preparing a dysprosium-doped calcium borate phosphor includes the following steps: S1, according to the chemical formula Ca 3-x B2O6: xDy 3+ The stoichiometric ratio of each element is taken as x=0.02. Calcium carbonate powder, boric acid powder and dysprosium trioxide powder are weighed out separately, ground and mixed evenly to form a mixture.
[0036] S2. Pre-sinter the mixture prepared in step S1.
[0037] The pre-sintering temperature is 600℃ and the pre-sintering time is 5 h.
[0038] S3. Cool the sintered product obtained in step S2 to room temperature and grind and mix it evenly.
[0039] S4. Calcine the grinding product obtained in step S3.
[0040] The calcination temperature was 950℃ and the calcination time was 5 h.
[0041] S5. After cooling the calcined product obtained in step S4 to room temperature, grind it evenly to obtain a dysprosium-doped phosphor luminescent material with calcium borate as the matrix.
[0042] Comparative Example 3 A method for preparing a dysprosium-doped magnesium borate phosphor includes the following steps: S1, according to the chemical formula Mg 3-x B2O6: xDy 3+ The stoichiometric ratio of each element is taken as x=0.02. Magnesium carbonate powder, boric acid powder and dysprosium trioxide powder are weighed separately, ground and mixed evenly to form a mixture.
[0043] S2. Pre-sinter the mixture prepared in step S1.
[0044] The pre-sintering temperature is 600℃ and the pre-sintering time is 5 h.
[0045] S3. Cool the sintered product obtained in step S2 to room temperature and grind and mix it evenly.
[0046] S4. Calcine the grinding product obtained in step S3.
[0047] The calcination temperature was 950℃ and the calcination time was 5 h.
[0048] S5. After cooling the calcined product obtained in step S4 to room temperature, grind it evenly to obtain a dysprosium-doped phosphor luminescent material with magnesium borate as the matrix.
[0049] Comparative Example 4 A method for preparing a dysprosium-doped strontium borate phosphor includes the following steps: S1, according to the chemical formula Sr 3-x B2O6: xDy 3+ The stoichiometric ratio of each element is taken as x=0.02. Strontium carbonate powder, boric acid powder and dysprosium trioxide powder are weighed separately, ground and mixed evenly to form a mixture.
[0050] S2. Pre-sinter the mixture prepared in step S1.
[0051] The pre-sintering temperature is 600℃ and the pre-sintering time is 5 h.
[0052] S3. Cool the sintered product obtained in step S2 to room temperature and grind and mix it evenly.
[0053] S4. Calcine the grinding product obtained in step S3.
[0054] The calcination temperature was 950℃ and the calcination time was 5 h.
[0055] S5. After cooling the calcined product obtained in step S4 to room temperature, grind it evenly to obtain a dysprosium-doped phosphor luminescent material with strontium borate as the matrix.
[0056] Comparative Example 5 A method for preparing dysprosium-doped barium borate phosphor includes the following steps: S1, according to the chemical formula Ba 3-x B2O6: xDy 3+ The stoichiometric ratio of each element is taken as x=0.04. Barium carbonate powder, boric acid powder and dysprosium trioxide powder are weighed separately, ground and mixed evenly to form a mixture.
[0057] S2. Calcine the mixture prepared in step S1.
[0058] The calcination temperature was 950℃ and the calcination time was 5 h.
[0059] S3. After cooling the calcined product obtained in step 2 to room temperature, grind it evenly to obtain a dysprosium-doped phosphor luminescent material with barium borate as the matrix.
[0060] Effect The materials prepared in Examples 1-5 and Comparative Examples 1-5 were applied to phosphor-converted warm white LEDs.
[0061] The specific steps are as follows: the materials prepared in Examples 1-5 and Comparative Examples 1-5 are respectively reacted with CaAlSiN3:Eu 2+ The mixture was thoroughly mixed at a mass ratio of 10:1 and coated onto an LED (1 W, Sanan Optoelectronics Co., Ltd.) chip using UV-curable adhesive (leaftop 9300). After curing, a phosphor-converted light-emitting diode (pc-LED) device was obtained, and the pc-LED was subsequently tested.
[0062] Figure 6 The dysprosium-doped barium borate yellow phosphor sample from Example 1 and the commercially available CaAlSiN3:Eu 2+ (Main peak 630nm, Intematix Co., Ltd.) was mixed uniformly at a mass ratio of 10:1 and coated onto an LED chip using UV-curable adhesive. After curing, a physical image of the phosphor-converted light-emitting diode device and electroluminescence spectra under different currents were obtained. It can be seen that the warm white light exhibits a broad-spectrum emission characteristic, with the weakest blue light near 410nm and a distinct cyan emission region in the 485-500nm range. Examples 2-5 also used commercially available CaAlSiN3:Eu 2+ It can achieve a warm white light broadband emission characteristic, and the blue light is weak near 410nm, while it has a distinct cyan emission region in the 485-500nm range.
[0063] Figure 7 a is the excitation spectrum of the samples from Example 3 and Comparative Examples 2-4 at an emission wavelength of 570 nm. Figure 7 b is the emission spectrum of the samples from Example 3 and Comparative Examples 2-4 under monitoring at an excitation wavelength of 350 nm. Figure 7 As can be seen in b, the barium borate emission spectrum prepared in Example 3 exhibits the strongest cyan emission in the 485-500 nm region. Figure 7As can be seen from the CD, the barium borate matrix has a significant advantage over the magnesium borate and strontium borate matrices, in which the emission of yellow phosphors was not achieved.
[0064] Comparative Examples 1-5 clearly do not possess the emission spectral characteristics and advantages of Examples 1-5. Comparative Example 1 is a pure calcium borate matrix, which lacks emission spectral characteristics. Comparative Examples 2-4 are phosphor materials prepared by doping different alkaline earth metal borates with dysprosium ions. Figure 7 As can be seen in examples a and b, the excitation spectra of dysprosium-doped calcium borate, dysprosium-doped magnesium borate, and dysprosium-doped strontium borate are relatively weak, with indistinct excitation peaks. Similarly, their emission spectra are also very weak, significantly less pronounced than those of the dysprosium-doped barium borate in Example 3. In the preparation of alkaline earth metal borates, pre-sintering is often necessary; otherwise, impurities such as calcium oxide or metaboric acid may appear as in Example 5, affecting the emission effect and luminescence characteristics, especially leading to low luminescence intensity or even no luminescence, and impacting the stability of the phosphor.
[0065] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.
Claims
1. A dysprosium-doped barium borate yellow phosphor, characterized in that: The chemical formula is Ba (3-x) B2O6:xDy 3+ , where x = 0.01 - 0.
1.
2. The method for preparing the dysprosium-doped barium borate yellow phosphor according to claim 1, characterized in that: Includes the following steps: S1. Take photos (3-x) B2O6:xDy 3+ The stoichiometric ratio of each element in the mixture was determined by weighing out the barium source powder, boron source powder, and dysprosium source powder, grinding and mixing them evenly to form a mixture. S2. The mixture prepared in step S1 is pre-sintered, then cooled to room temperature and ground and mixed evenly. S3. The grinding product obtained in step S2 is calcined. After the calcined product is cooled to room temperature, it is ground evenly to obtain dysprosium-doped barium borate yellow phosphor.
3. The method for preparing dysprosium-doped barium borate yellow phosphor according to claim 2, characterized in that: The barium source is at least one of barium carbonate, barium hydroxide, barium chloride, barium nitrate, barium sulfate, and barium phosphate; the boron source is boric acid, boron trioxide, or elemental boron; and the dysprosium source is at least one of dysprosium oxide, dysprosium nitrate, and dysprosium carbonate.
4. The method for preparing dysprosium-doped barium borate yellow phosphor according to claim 2, characterized in that: The pre-sintering temperature is 300-700℃, and the pre-sintering time is 2-8 h.
5. The method for preparing dysprosium-doped barium borate yellow phosphor according to claim 2, characterized in that: The sintering temperature is 800-1200℃, and the calcination time is 2-10 h.
6. The application of the dysprosium-doped barium borate yellow phosphor according to claim 1 in warm white LED lighting, characterized in that: Specifically, it includes: Dysprosium-doped barium borate yellow phosphor was combined with CaAlSiN3:Eu 2+ The mixture is thoroughly mixed and then coated onto the LED chip using UV-curable adhesive. After curing, a phosphor-converted light-emitting diode device is obtained.