Cr < 3 + >-doped strontium feldspar red fluorescent powder and preparation method thereof
By doping Cr3+ ions into strontium feldspar, SrAl2-xSi2O8:xCr3+ red phosphor was prepared, which solved the problem of limited rare earth resources, realized narrow-band red light emission, and enhanced the application value of the phosphor.
Patent Information
- Application Number
- CN202510981210.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-16
- Publication Date
- 2025-11-04
AI Technical Summary
Existing technologies for rare earth ion-doped strontium feldspar phosphors suffer from problems such as limited rare earth resources and high prices, and have failed to achieve narrowband red light emission.
By using Cr3+ ion-doped strontium feldspar, chromium ions are doped into strontium feldspar to form chromium octahedral sites, which generate narrow-band red light emission, a red phosphor with the chemical formula SrAl2-xSi2O8:xCr3+ is prepared.
It achieves narrowband red light emission and provides sharp red phosphor materials, offering high-quality materials for applications in LED light sources, spectral analysis, laser fabrication, and biomedicine.
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Figure CN120888299A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of luminescent materials and preparation methods thereof, and particularly relates to a Cr 3+ doped strontium feldspar red fluorescent powder and a preparation method thereof. BACKGROUND
[0002] Strontium feldspar (SrAl2Si2O8) is an important aluminosilicate material, which has a wide range of applications in the aerospace industry, electronic industry, environmental protection and other fields due to its unique physical and chemical properties (low density, small thermal expansion coefficient, good high-temperature stability, excellent dielectric performance and excellent chemical stability).
[0003] Currently, there are some research reports on the preparation of fluorescent powder materials by doping rare earth ions in strontium feldspar. For example, Ma et al. prepared SrAl2Si2O8:Ce 3+ / Tb 3+ fluorescent powder, which realized the luminescence adjustment of the fluorescent powder from blue light to green light by changing the doping ratio of Ce 3+ and Tb 3+ , the energy transfer efficiency reached 82.91%, the quantum efficiency was 67.37%, and good thermal stability was exhibited. Xue et al. prepared Eu 2+ / Eu 3+ activated SrAl2Si2O8 fluorescent powder, and the photoluminescence intensity was enhanced with the increase of Eu 2+ / Eu 3+ doping content. Yang et al. prepared a series of rare earth ion doped SrAl2Si2O8 fluorescent powder, and it was found that the best doping concentration of Dy³⁺ was 0.8%, the best CIE coordinate was (0.275, 0.308); the best doping concentration of Tb³⁺ was 9%, the best CIE coordinate of Sm 3+ was (0.316, 0.386), and the energy transfer efficiency of Sm 3+ fluorescent powder was 85.4%, indicating that the rare earth ion doped SrAl2Si2O8 fluorescent powder can be used for white light LEDs. However, the rare earth has the problems of limited source and high price. Transition metals are relatively abundant in the earth's crust and have low cost. Therefore, it is of important research value and application prospect to study transition metal ion doped fluorescent powder. SUMMARY
[0004] To solve or partially solve the problems in the related art, the application provides a Cr 3+ doped strontium feldspar red fluorescent powder and a preparation method thereof.
[0005] The application provides a Cr 3+ doped strontium feldspar red fluorescent powder, which has a chemical formula of SrAl 2-xSi2O8: xCr 3+ wherein x = 0.005-0.06; narrow-band red light emission with a half-peak width of 3.04 nm and a peak value of 694 nm is achieved under light excitation at 415 nm.
[0006] A Cr 3+ The preparation method of the doped strontium feldspar red fluorescent powder comprises the following steps: S1, irradiating SrAl 2-x Si2O8: xCr 3+ The stoichiometric ratio of each element in the mixture is determined, and the aluminum-containing compound, the strontium-containing compound, the silicon-containing compound and the chromium-containing compound are weighed and mixed uniformly to form a mixture; S2, the mixture obtained in step S1 is calcined, and after cooling to room temperature, the mixture is uniformly ground to obtain Cr 3+ The doped strontium feldspar red fluorescent powder.
[0007] Preferably, the aluminum-containing compound is one of aluminum oxide, aluminum hydroxide, aluminum sulfate, aluminum nitrate and aluminum chloride; the strontium-containing compound is one of strontium carbonate, strontium oxide, strontium sulfate, strontium nitrate, strontium silicate and strontium chloride; the silicon-containing compound is one of silicon dioxide, silicic acid and orthosilicic acid; and the chromium-containing compound is one of chromium oxide, chromium carbonate, chromium hydroxide, chromium sulfate, chromium nitrate and chromium chloride.
[0008] Preferably, the calcination temperature is 1200-1400 DEG C, and the time is 1-5 hours.
[0009] The principle of the present application is: The present application discloses a preparation method of a doped strontium feldspar red fluorescent powder.
[0010] The technical solution provided by this invention has the following beneficial effects: The chromium-doped strontium feldspar red phosphor prepared by this invention can emit narrow-band red light or near-infrared light, providing a relatively ideal material for preparing sharp narrow-band emission red phosphors and phosphor-converted LED (pc-LED) light sources. At the same time, it can promote the application of phosphors and their LEDs in fields such as spectral analysis, laser preparation, and biomedicine, especially playing an important role in precisely targeting melanin particles in the skin. Attached Figure Description
[0011] Figure 1 The images show the XRD patterns of the materials prepared in Examples 1-5 and Comparative Example 1.
[0012] Figure 2 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.
[0013] Figure 3 The image shows a scanning electron microscope (SEM) image of the phosphor prepared in Example 1.
[0014] Figure 4 The images show the XRD patterns of the phosphors prepared in Examples 1, 6, and 7.
[0015] Figure 5 Digital photographs of LEDs converted by the phosphors prepared in Examples 1, 6 and 7: (a) is a physical image of the packaged pc-LED device; (b) is a photograph of the pc-LED emitting red light after being lit; and (c) is a photograph of the emission spectrum at different current levels. Detailed Implementation
[0016] Example 1 A method for preparing a chromium-doped strontium feldspar phosphor, specifically including the following steps: (1) According to SrAl 1.98 Si2O8: 0.02Cr 3+ Stoichiometric ratio: Weigh out strontium carbonate (SrCO3, analytical grade), aluminum oxide (Al2O3, analytical grade), silicon dioxide (SiO2, analytical grade) and chromium oxide (Cr2O3, analytical grade), mix them evenly, and grind them thoroughly in an agate mortar to obtain a mixture.
[0017] (2) Place the ground mixture powder in a corundum crucible and calcine it in air at 1300°C for 3 hours. Then, let it cool naturally to room temperature to obtain a sintered body. (3) The obtained sintered body is ground evenly to obtain SrAl. 1.98 Si2O8: 0.02Cr 3+ Red fluorescent powder.
[0018] Example 2 A method for preparing a chromium-doped strontium feldspar phosphor, specifically including the following steps: (1) According to SrAl 1.96 Si2O8: 0.04Cr 3+ Stoichiometric ratio: Weigh out strontium carbonate (SrCO3, analytical grade), aluminum oxide (Al2O3, analytical grade), silicon dioxide (SiO2, analytical grade) and chromium oxide (Cr2O3, analytical grade), mix them evenly, and grind them thoroughly in an agate mortar to obtain a mixture.
[0019] (2) Place the ground mixture powder in a corundum crucible and calcine it in air at 1300°C for 3 hours. Then, let it cool naturally to room temperature to obtain a sintered body. (3) The obtained sintered body is ground evenly to obtain SrAl. 1.96 Si2O8: 0.04Cr 3+ Red fluorescent powder.
[0020] Example 3 A method for preparing a chromium-doped strontium feldspar phosphor, specifically including the following steps: (1) According to SrAl 1.94 Si2O8: 0.06Cr 3+ Stoichiometric ratio: Weigh out strontium carbonate (SrCO3, analytical grade), aluminum oxide (Al2O3, analytical grade), silicon dioxide (SiO2, analytical grade) and chromium oxide (Cr2O3, analytical grade), mix them evenly, and grind them thoroughly in an agate mortar to obtain a mixture.
[0021] (2) Place the ground mixture powder in a corundum crucible and calcine it in air at 1300°C for 3 hours. Then, let it cool naturally to room temperature to obtain a sintered body. (3) The obtained sintered body is ground evenly to obtain SrAl. 1.94 Si2O8: 0.06Cr 3+ Red fluorescent powder.
[0022] Example 4 A method for preparing a chromium-doped strontium feldspar phosphor, specifically including the following steps: (1) According to SrAl 1.99 Si2O8: 0.01Cr 3+ Stoichiometric ratio: Weigh out strontium carbonate (SrCO3, analytical grade), aluminum oxide (Al2O3, analytical grade), silicon dioxide (SiO2, analytical grade) and chromium oxide (Cr2O3, analytical grade), mix them evenly, and grind them thoroughly in an agate mortar to obtain a mixture.
[0023] (2) Place the ground mixture powder in a corundum crucible and calcine it in air at 1300°C for 3 hours. Then, let it cool naturally to room temperature to obtain a sintered body. (3) The obtained sintered body is ground evenly to obtain SrAl. 1.99 Si2O8: 0.01Cr 3+ Red fluorescent powder.
[0024] Example 5 A method for preparing a chromium-doped strontium feldspar phosphor, specifically including the following steps: (1) According to SrAl 1.995 Si2O8: 0.005Cr 3+ Stoichiometric ratio: Weigh out strontium carbonate (SrCO3, analytical grade), aluminum oxide (Al2O3, analytical grade), silicon dioxide (SiO2, analytical grade) and chromium oxide (Cr2O3, analytical grade), mix them evenly, and grind them thoroughly in an agate mortar to obtain a mixture.
[0025] (2) Place the ground mixture powder in a corundum crucible and calcine it in air at 1300°C for 3 hours. Then, let it cool naturally to room temperature to obtain a sintered body. (3) The obtained sintered body is ground evenly to obtain SrAl. 1.995 Si2O8: 0.005Cr 3+ Red fluorescent powder.
[0026] Example 6 The difference between this embodiment of the method for preparing chromium-doped strontium feldspar phosphor and that of Embodiment 1 is that in step (2), the calcination temperature is 1200℃ and the time is 1h.
[0027] Example 7 The difference between this embodiment of the method for preparing chromium-doped strontium feldspar phosphor and that of Embodiment 1 is that in step (2), the calcination temperature is 1400℃ and the time is 5h.
[0028] Comparative Example 1 The difference between this comparative example of a strontium feldspar phosphor preparation method and Example 1 is that chromium doping is not performed in step (1).
[0029] Comparative Example 2 The difference between this comparative example of a method for preparing strontium feldspar phosphor and Example 1 is that in step (1), x = 0.1.
[0030] like Figure 1 As shown, the XRD patterns of the chromium-doped red phosphors prepared in Examples 1-5 and the pure strontium feldspar prepared in Comparative Example 1 are not significantly different from those of the standard strontium feldspar, indicating that the prepared strontium feldspar matrix has good crystallinity.
[0031] like Figure 2 As shown, the excitation wavelength Ex = 415 nm and the emission wavelength Em = 694 nm. From Figure 2 As can be seen from Examples 1-5, the phosphors prepared in Examples 1-5 can achieve very narrow and sharp red emission at 694 nm under near-ultraviolet light excitation with an excitation wavelength of 415 nm. However, in Comparative Example 1, strontium feldspar, as the pure matrix, does not emit light, indicating that only by doping with trace amounts of chromium ions can very narrow and sharp red emission at 694 nm be achieved. In Comparative Example 2, due to excessive chromium ion doping, the prepared material has weak luminescence intensity, almost to the point of not emitting light.
[0032] like Figure 3 As shown, the phosphor prepared in Example 1 has a micron-scale sheet-like structure with a relatively uniform size distribution.
[0033] like Figure 4 As shown, different calcination temperatures have a significant impact on the formation of strontium feldspar crystal structures. At lower temperatures, a single-phase structure cannot be formed, compromising the stability and luminescence properties of the matrix. For example, samples calcined at 1200℃ exhibit obvious impurity peaks, indicating that a single-phase structure has not been formed, thus failing to guarantee matrix stability and luminescence properties. Samples calcined at higher temperatures form a single-phase structure consistent with the standard card, making them suitable as a phosphor luminescent matrix. For instance, samples calcined at 1300℃ and 1400℃ form single-phase structures consistent with the standard card.
[0034] The SrAl obtained in Example 1 1.98 Si2O8: 0.02Cr 3+ Red phosphor and UV-curable adhesive (Lantian 9300) were mixed uniformly at a 1:1 mass ratio and coated onto a 400-415 nm LED chip (1W, Sanan Optoelectronics), then cured and encapsulated to form a pc-LED device. The electroluminescence (EL) characteristics and current-dependent emission spectrum of this pc-LED were tested using an OHSP-350M LED fast scanning spectrophotometer (Hangzhou Huapu Optoelectronics Technology Co., Ltd.). Figure 5 As shown, the packaged pc-LED device exhibits excellent red light emission performance after being lit.
[0035] 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 type of Cr 3+ The doped strontium feldspar red phosphor is characterized by: The chemical formula is SrAl 2-x Si2O8:xCr 3+ , where x=0.005-0.06; under 415 nm light excitation, narrowband red light emission with a half width at half maximum (FWHM) of 3.04 nm and an emission peak of 694 nm is achieved.
2. The Cr as described in claim 1 3+ A method for preparing doped strontium feldspar red phosphor, characterized in that: Includes the following steps: S1, SrAl 2-x Si2O8:xCr 3+ The stoichiometric ratio of each element in the mixture was determined by weighing out aluminum-containing compounds, strontium-containing compounds, silicon-containing compounds, and chromium-containing compounds, grinding and mixing them evenly to form a mixture. S2. Calcine the mixture obtained in step S1, cool it to room temperature, and then grind it evenly to obtain Cr. 3+ Doped with strontium feldspar red fluorescent powder.
3. The Cr according to claim 2 3+ A method for preparing doped strontium feldspar red phosphor, characterized in that: The aluminum-containing compound is one of aluminum oxide, aluminum hydroxide, aluminum sulfate, aluminum nitrate, and aluminum chloride; the strontium-containing compound is one of strontium carbonate, strontium oxide, strontium sulfate, strontium nitrate, strontium silicate, and strontium chloride; the silicon-containing compound is one of silicon dioxide, silicic acid, and orthosilicic acid; and the chromium-containing compound is one of chromium oxide, chromium carbonate, chromium hydroxide, chromium sulfate, chromium nitrate, and chromium chloride.
4. The Cr according to claim 2 3+ A method for preparing doped strontium feldspar red phosphor, characterized in that: The calcination temperature is 1200-1400℃, and the time is 1-5 hours.