A type of multiphase Eu 2+ Blue-cyan phosphors doped with charge compensators and their preparation methods

Abstract

The application discloses a kind of by multi-phase Eu 2+ And charge compensation agent doped blue cyan fluorescent powder and its preparation method, belong to fluorescent powder technical field, by multi-phase Eu 2+ And charge compensation agent doped blue cyan fluorescent powder molar ratio general formula is: KAlSi3O8:3mol%Eu 2+ :Xmol%M + , and 1.0≤x≤11.0, wherein M + It is selected from Li + , Na + , Rb + , Cs + Four charge compensation ions, and the ionic radius of M + With K + There is controllable difference.Benefiting from the unique structural design, the prepared fluorescent powder can emit adjustable strong blue cyan light under near ultraviolet-blue light excitation, and the luminescence thermal quenching performance, quantum efficiency and spectral stability are all significantly improved.The fluorescent powder is applied to white light LED device packaging, and the efficient and wide-spectrum blue cyan emission and cyan spectral component can be used.Only by matching with a blue light chip and a single yellow / red fluorescent powder, high-quality full-spectrum white light with high color rendering index can be realized under the conditions of simplifying packaging process and reducing cost, and the fluorescent powder shows important application prospects in the fields of healthy lighting, high-end display and precise spectral design.

Description

Technical Field

[0001] This invention belongs to the field of phosphor technology, specifically relating to multiphase Eu... 2+ Blue-cyan phosphors doped with charge compensators and their preparation methods. Background Technology

[0002] White LEDs, as the fourth generation of lighting sources, have become the preferred solution for modern lighting technology due to their high efficiency and low cost. However, the commonly used scheme of combining near-ultraviolet chips with three-color phosphors to obtain white LEDs has the following problems: 1) Multicolor phosphors may cause reabsorption, which refers to spectral overlap; for example, the excitation spectrum of red phosphor (i.e., the spectral range that can be absorbed and converted into light emission) may overlap with the emission spectrum of green phosphor (i.e., the spectral range emitted by green phosphor after excitation); 2) The blank space in the cyan emission region (480-500nm) has a significant impact on the color rendering index (an important parameter of WLED device performance). To fill this blank space, adding cyan phosphor will increase the difficulty of WLED device packaging.

[0003] Excellent broadband cyan phosphors can effectively fill the gaps in cyan emission while avoiding reabsorption phenomena in multicolor phosphors and simplifying LED device packaging processes. However, due to the inherent crystal field environment characteristics of the matrix material, researchers usually have to adopt the following two strategies to prepare cyan phosphors with excellent performance: one is to regulate the crystal field structure through complex cation substitution, and the other is to rely on the synergistic effect of co-doping with multiple activator ions. Although these methods can achieve cyan emission to a certain extent, they generally have the following prominent problems: 1) The preparation process is cumbersome and complex, involving multiple doping steps or precise component control; 2) The chemical stability of the material system is easily affected by doping.

[0004] Leucite (KAlSi2O6), due to its highly symmetrical tetragonal crystal structure, exhibits unique application potential in the field of luminescent materials. This is also reflected in its use as a matrix for synthesizing high-performance cyan phosphors (the matrix is ​​the main material of the phosphor). However, its traditional solid-state synthesis method usually requires calcination at a high temperature of 1400℃ and a holding time of up to 480 minutes. This harsh synthesis condition brings the following problems: 1) The long-term high-temperature treatment significantly increases energy consumption, which is not conducive to the economics of large-scale production; 2) The material performance is limited: high temperature can easily lead to component volatilization (such as the loss of potassium) or lattice defects, affecting the purity and luminous efficiency of the final phosphor.

[0005] In conclusion, developing broadband cyan phosphors that combine excellent performance, simple manufacturing process, and low cost is of great significance for promoting the development of the lighting field. Summary of the Invention

[0006] The purpose of this invention is to provide a highly efficient Eu²⁺ method for precisely controlling the potassium feldspar to leucite phase transition process based on charge compensators. + This invention relates to doped blue-cyan phosphors and their preparation methods, aiming to address the problems existing in the prior art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A type of multiphase Eu 2+ and charge-compensating agent-doped blue-cyan phosphors, multiphase Eu 2+ The general formula for the molar ratio of charge compensator-doped blue-cyan phosphor is: KAlSi3O8:3mol%Eu 2+ xmol%M + M + For Li + Na + 、Rb + Cs + Any four charge-compensating ions, and M + The ionic radius and K + There are controllable differences, and 1.0≤x≤11.0.

[0008] A type of multiphase Eu 2+ A method for preparing blue-cyan phosphor doped with charge compensator includes the following steps: Step 1: Material preparation; including natural potassium feldspar, lithium carbonate powder, sodium carbonate powder, rubidium carbonate powder, europium oxide powder, and cesium chloride powder. Step 2: Set the gradient stoichiometric molar ratio as: KAlSi3O8: 3mol%Eu 2+ xmol%M + And 1≤ x ≤11.0; Calculate the amount of material according to the stoichiometric molar ratio, and weigh the natural potassium feldspar, lithium carbonate powder, sodium carbonate powder, rubidium carbonate powder, europium trioxide powder and cesium chloride powder in equal proportions using an electronic balance. The mass of KAlSi3O8 weighed is always 2783.483 mg, and the mass of Eu2O3 weighed is always 3 mol%Eu2O3=52.7895 mg. Weigh Li2CO3, Na2CO3, Rb2CO3 and CsCl according to batch. Step 3: Place the weighed raw materials into an agate mortar and grind them thoroughly for 20 minutes; Step 4: Transfer the ground raw materials sequentially into the alumina crucible; Step 5: Place the crucible in the box furnace and provide a reducing atmosphere for sintering the sample in a carbon powder environment, and sinter at the set temperature; Step 6: After the sintered sample has cooled to room temperature, remove it and grind it into powder for 20 minutes.

[0009] A type of multiphase Eu 2+ The application of blue-cyan phosphors doped with charge compensation agents in LED light-emitting devices.

[0010] An LED light-emitting device includes a blue-cyan phosphor, a near-ultraviolet chip, and a red phosphor, wherein the blue-cyan phosphor comprises multiphase Eu... 2+ And blue-cyan phosphors doped with charge compensators.

[0011] Compared with the prior art, the beneficial effects of the present invention are: 1. A blue-cyan phosphor with ultrawide bandwidth, KAlSi3O8:3mol%Eu, was prepared. 2+ xmol%M + M + Li + Na + 、Rb + Cs + With a 365 nm near-ultraviolet chip and commercial red phosphor (Sr,Ca)AlSiN3:Eu 2+ By combining these methods to obtain white LED devices, the previous process of combining red, green, and blue phosphors to obtain white light has been simplified, and the reabsorption effect has been reduced. 2. By precisely adjusting M + (M + Li + Na + 、Rb + Cs + By adjusting the doping concentration, a continuously tunable emission spectrum from blue (406 nm) to cyan (480 nm) can be achieved, effectively filling the emission gap of traditional fluorescent materials in the cyan band of 480-500 nm. This controllable emission modulation not only optimizes the spectral continuity of white LEDs and significantly improves the color rendering index (Ra=95.5), but also provides a key cyan emission component (Peak emission=480 nm) for full-spectrum lighting. 3. Utilizing the inherent properties of potassium feldspar, by incorporating Eu... 2+ This process transforms some potassium feldspar (KAlSi3O8) into leucite (KAlSi2O6). Through the sintering process of natural potassium feldspar, a multiphase material in which potassium feldspar and leucite coexist can be finally prepared, which combines the advantages of both and reduces production costs. Attached Figure Description

[0012] The accompanying drawings described below are merely some embodiments. Those skilled in the art can obtain other drawings based on these drawings without any inventive effort. In the drawings: Figure 1 KAlSi3O8: x mol%Li + KAlSi3O8: y mol%Na + KAlSi3O8: m mol%Rb + XRD pattern; Figure 2 KAlSi3O8:3mol%Eu 2+ : x mol%Li + XRD pattern, KAlSi3O8:3mol%Eu 2+ : x mol%Li + Emission spectrum, KAlSi3O8:3mol%Eu 2+ : x mol%Li + Normalized emission spectrum, KAlSi3O8:3mol%Eu 2+ : x mol%Li + Excitation spectrum; Figure 3 KAlSi3O8:3mol%Eu 2+ : y mol%Na + XRD pattern, KAlSi3O8:3mol%Eu 2+ : y mol%Na + Emission spectrum, KAlSi3O8:3mol%Eu 2+ : y mol%Na + Normalized emission spectrum, KAlSi3O8:3mol%Eu 2+ : y mol%Na + Excitation spectrum; Figure 4 For low concentration KAlSi3O8: 3mol%Eu 2+ : y mol%Na + XRD pattern, low concentration KAlSi3O8: 3mol%Eu 2+ : y mol%Na +Emission spectrum, low concentration KAlSi3O8: 3mol%Eu 2+ : y mol%Na + Normalized emission spectrum, low concentration KAlSi3O8: 3mol%Eu 2+ : y mol%Na + Excitation spectrum; Figure 5 KAlSi3O8:3mol%Eu 2+ : m mol%Rb + XRD pattern, KAlSi3O8:3mol%Eu 2+ : m mol%Rb + Emission spectrum, KAlSi3O8:3mol%Eu 2+ : m mol%Rb + Normalized emission spectrum, KAlSi3O8:3mol%Eu 2+ : m mol%Rb + Excitation spectrum; Figure 6 KAlSi3O8:3mol%Eu 2+ : n mol%Cs + XRD pattern, KAlSi3O8:3mol%Eu 2+ : n mol%Cs + Emission spectrum, KAlSi3O8:3mol%Eu 2+ : n mol%Cs + Normalized emission spectrum, KAlSi3O8:3mol%Eu 2+ : n mol%Cs + Excitation spectrum; Figure 7 Crystal structure diagrams of KAlSi3O8 and KAlSi2O6; Figure 8 KAlSi3O8:3mol%Eu 2+ 1 mol% Na + Packaging spectrum. Detailed Implementation

[0013] The following embodiments are further illustrations of the present invention, but not limitations thereof. Experimental methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions in the art or as recommended by the manufacturer; the raw materials and reagents used, unless otherwise specified, are considered to be commercially available through conventional markets. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention are within the scope of protection claimed by the present invention.

[0014] A type of multiphase Eu 2+ and charge-compensating agent-doped blue-cyan phosphors, multiphase Eu 2+ The general formula for the molar ratio of charge compensator-doped blue-cyan phosphor is: KAlSi3O8:3mol%Eu 2+ xmol%M + M + For Li + Na + 、Rb + Cs + Any one of four charge-compensating ions, and the M + The ionic radius and K + There are controllable differences, and 1.0≤x≤11.0.

[0015] A type of multiphase Eu 2+ A method for preparing blue-cyan phosphor doped with charge compensator includes the following steps: Step 1: Material preparation; including natural potassium feldspar, europium trioxide powder, lithium carbonate powder, sodium carbonate powder, rubidium carbonate powder, and cesium chloride powder. The natural potassium feldspar powder is selected from the Altay region of Xinjiang, with a purity of 95%, and the remaining 5% consists of silicon dioxide and calcium carbonate; the europium trioxide powder, used as an activator, is produced by Shanghai Aladdin Biochemical Technology Co., Ltd., with a purity of 99.99%; the lithium carbonate powder, sodium carbonate powder, rubidium carbonate powder, and cesium chloride powder, used as charge compensators, are also produced by Shanghai Aladdin Biochemical Technology Co., Ltd., with a purity of 99.99%. Step Two: Determine the raw materials required for preparation based on the elemental composition of the target phosphor. Prepare the matrix: natural potassium feldspar powder, europium trioxide powder, lithium carbonate powder, sodium carbonate powder, rubidium carbonate powder, and cesium chloride powder. Calculate the amount of raw materials according to the stoichiometric molar ratio. Weigh the equal proportions of natural potassium feldspar (KAlSi3O8), europium trioxide (Eu2O3), lithium carbonate (Li2CO3), sodium carbonate (Na2CO3), rubidium carbonate (Rb2CO3), and cesium chloride (CsCl) using an electronic balance. The stoichiometric molar ratio is KAlSi3O8:3 mol%Eu 2+ xmol%M + M+ Li + Na + 、Rb + Cs + 1.0≤x≤11.0, the mass of KAlSi3O8 weighed is always 2783.483mg, the mass of 3 mol%Eu2O3 weighed is always 52.7895mg, and the mass of Li2CO3, Na2CO3, Rb2CO3 and CsCl are weighed according to batch; Step 3: Place the weighed raw materials into an agate mortar and grind them thoroughly for 20 minutes; Step 4: Transfer the ground raw materials sequentially into the alumina crucible; Step 5: Place the crucible in the box furnace and provide a reducing atmosphere for sintering the sample in a carbon powder environment, and sinter at the set temperature; In the reducing atmosphere, the reducing substance is carbon powder; the box furnace is set as follows: heating rate of 5℃ / min, holding at 1200℃ for 3h; Carbon powder is used as a reducing agent to reduce Eu. 3+ For Eu 2+ ; Step 6: After the sintered sample has cooled to room temperature, remove it and grind it into powder for 20 minutes.

[0016] Raw material properties: Potassium feldspar (KAlSi3O8) is the matrix of phosphors, and this matrix is ​​the main material of phosphors; Europium trioxide (Eu2O3) is an activator for phosphors. Activators are ions incorporated into matrix materials that can absorb energy and convert it into characteristic light emission. Charge compensators: lithium carbonate (Li2CO3), sodium carbonate (Na2CO3), rubidium carbonate (Rb2CO3), cesium chloride (CsCl); charge compensators precisely regulate the lattice phase transition structure and synergistically enhance luminescence performance.

[0017] Agate mortar and pestle, a grinding tool to avoid contamination of raw materials; Alumina crucible, a high-temperature resistant container for the high-temperature solid-phase reaction stage; A box furnace is a calcination instrument that provides a reducing atmosphere during the high-temperature solid-phase reaction stage.

[0018] By multiphase Eu 2+ Application of charge-compensating agent-doped blue-cyan phosphors in LED light-emitting devices; An LED light-emitting device includes a blue-cyan phosphor, a 365 nm near-ultraviolet chip, and a red phosphor. The blue-cyan phosphor comprises a multiphase Eu... 2+ And a blue-cyan phosphor doped with charge compensator, the red phosphor being a commercially available red phosphor (Sr,Ca)AlSiN3:Eu2+ .

[0019] Example 1: Under the same conditions, the mass of KAlSi3O8 is 2783.483 mg, the mass of Eu2O3 is 3 mol% Eu2O3 = 52.7895 mg, and the mass of Li2CO3 is 1 mol% Li2CO3 = 3.66945 mg. The percentages of the compounds are molar percentages. Example 2: Under the same conditions, the mass of KAlSi3O8 is 2783.483 mg, the mass of Eu2O3 is 3 mol% Eu2O3 = 52.7895 mg, and the mass of Li2CO3 is 3 mol% Li2CO3 = 11.0835 mg. The percentages of the compounds are molar percentages.

[0020] Example 3: Under the same conditions, the mass of KAlSi3O8 is 2783.483 mg, the mass of Eu2O3 is 3 mol% Eu2O3 = 52.7895 mg, and the mass of Li2CO3 is 5 mol% Li2CO3 = 18.4725 mg. The percentages of the compounds are molar percentages. Example 4: Under the same conditions, the mass of KAlSi3O8 is 2783.483 mg, the mass of Eu2O3 is 3 mol% Eu2O3 = 52.7895 mg, and the mass of Li2CO3 is 7 mol% Li2CO3 = 25.8615 mg. The percentages of the compounds are molar percentages.

[0021] Example 5: Under the same conditions, the mass of KAlSi3O8 is 2783.483 mg, the mass of Eu2O3 is 3 mol% Eu2O3 = 52.7895 mg, and the mass of Li2CO3 is 9 mol% Li2CO3 = 33.2505 mg. The percentages of the compounds are molar percentages.

[0022] Example 6: Under the same conditions, the mass of KAlSi3O8 is 2783.483 mg, the mass of Eu2O3 is 3 mol% Eu2O3 = 52.7895 mg, and the mass of Li2CO3 is 11 mol% Li2CO3 = 40.6395 mg. The percentages of the compounds are molar percentages.

[0023] Example 7: Under the same conditions, the mass of KAlSi3O8 is 2783.483 mg, the mass of Eu2O3 is 3 mol% Eu2O3 = 52.7895 mg, and the mass of Na2CO3 is 1 mol% Na2CO3 = 5.2995 mg. The percentages of the compounds are molar percentages.

[0024] Example 8: Under the same conditions, the mass of KAlSi3O8 is 2783.483 mg, the mass of Eu2O3 is 3 mol% Eu2O3 = 52.7895 mg, and the mass of Na2CO3 is 3 mol% Na2CO3 = 15.8985 mg. The percentages of the compounds are molar percentages.

[0025] Example 9: Under the same conditions, the mass of KAlSi3O8 is 2783.483 mg, the mass of Eu2O3 is 3 mol% Eu2O3 = 52.7895 mg, and the mass of Na2CO3 is 5 mol% Na2CO3 = 26.4975 mg. The percentages of the compounds are molar percentages.

[0026] Example 10: Under the same conditions, the mass of KAlSi3O8 is 2783.483 mg, the mass of Eu2O3 is 3 mol% Eu2O3 = 52.7895 mg, and the mass of Na2CO3 is 7 mol% Na2CO3 = 37.0965 mg. The percentages of the compounds are molar percentages.

[0027] Example 11: Under the same conditions, the mass of KAlSi3O8 is 2783.483 mg, the mass of Eu2O3 is 3 mol% Eu2O3 = 52.7895 mg, and the mass of Na2CO3 is 9 mol% Na2CO3 = 47.6955 mg. The percentages of the compounds are molar percentages.

[0028] Example 12: Under the same conditions, the mass of KAlSi3O8 is 2783.483 mg, the mass of Eu2O3 is 3 mol% Eu2O3 = 52.7895 mg, and the mass of Na2CO3 is 11 mol% Na2CO3 = 58.2945 mg. The percentages of the compounds are molar percentages.

[0029] Example 13: Under the same conditions, the mass of KAlSi3O8 is 2783.483 mg, the mass of Eu2O3 is 3 mol% Eu2O3 = 52.7895 mg, and the mass of Na2CO3 is 0.5 mol% Na2CO3 = 2.64975 mg. The percentages of the compounds are molar percentages.

[0030] Example 14: Under the same conditions, the mass of KAlSi3O8 is 2783.483 mg, the mass of Eu2O3 is 3 mol% Eu2O3 = 52.7895 mg, and the mass of Na2CO3 is 1 mol% Na2CO3 = 5.2995 mg. The percentages of the compounds are molar percentages.

[0031] Example 15: Under the same conditions, the mass of KAlSi3O8 is 2783.483 mg, the mass of Eu2O3 is 3 mol% Eu2O3 = 52.7895 mg, and the mass of Na2CO3 is 1.5 mol% Na2CO3 = 7.94925 mg. The percentages of the compounds are molar percentages.

[0032] Example 16: Under the same conditions, the mass of KAlSi3O8 is 2783.483 mg, the mass of Eu2O3 is 3 mol% Eu2O3 = 52.7895 mg, and the mass of Na2CO3 is 2 mol% Na2CO3 = 10.599 mg. The percentages of the compounds are molar percentages.

[0033] Example 17: Under the same conditions, the mass of KAlSi3O8 is 2783.483 mg, the mass of Eu2O3 is 3 mol% Eu2O3 = 52.7895 mg, and the mass of Na2CO3 is 2.5 mol% Na2CO3 = 13.24875 mg. The percentages of the compounds are molar percentages.

[0034] Example 18: Under the same conditions, the mass of KAlSi3O8 is 2783.483 mg, the mass of Eu2O3 is 3 mol% Eu2O3 = 52.7895 mg, and the mass of Na2CO3 is 3 mol% Na2CO3 = 15.8985 mg. The percentages of the compounds are molar percentages.

[0035] Example 19: Under the same conditions, the mass of KAlSi3O8 is 2783.483 mg, the mass of Eu2O3 is 3 mol% Eu2O3 = 52.7895 mg, and the mass of Rb2CO3 is 1 mol% Rb2CO3 = 11.5395 mg. The percentages of the compounds are molar percentages.

[0036] Example 20: Under the same conditions, the mass of KAlSi3O8 is 2783.483 mg, the mass of Eu2O3 is 3 mol% Eu2O3 = 52.7895 mg, and the mass of Rb2CO3 is 3 mol% Rb2CO3 = 34.6185 mg. The percentages of the compounds are molar percentages.

[0037] Example 21: Under the same conditions, the mass of KAlSi3O8 is 2783.483 mg, the mass of Eu2O3 is 3 mol% Eu2O3 = 52.7895 mg, and the mass of Rb2CO3 is 5 mol% Rb2CO3 = 57.6975 mg. The percentages of the compounds are molar percentages.

[0038] Example 22: Under the same conditions, the mass of KAlSi3O8 is 2783.483 mg, the mass of Eu2O3 is 3 mol% Eu2O3 = 52.7895 mg, and the mass of Rb2CO3 is 7 mol% Rb2CO3 = 80.7765 mg. The percentages of the compounds are molar percentages.

[0039] Example 23: Under the same conditions, the mass of KAlSi3O8 is 2783.483 mg, the mass of Eu2O3 is 3 mol% Eu2O3 = 52.7895 mg, and the mass of Rb2CO3 is 9 mol% Rb2CO3 = 103.8555 mg. The percentages of the compounds are molar percentages.

[0040] Example 24: Under the same conditions, the mass of KAlSi3O8 is 2783.483 mg, the mass of Eu2O3 is 3 mol% Eu2O3 = 52.7895 mg, and the mass of Rb2CO3 is 11 mol% Rb2CO3 = 126.9345 mg. The percentages of the compounds are molar percentages.

[0041] Example 25: Under the same conditions, the mass of KAlSi3O8 is 2783.483 mg, the mass of Eu2O3 is 3 mol% Eu2O3 = 52.7895 mg, and the mass of CsCl is 1 mol% CsCl = 16.836 mg. The percentages of the compounds are molar percentages.

[0042] Example 26: Under the same conditions, the mass of KAlSi3O8 is 2783.483 mg, the mass of Eu2O3 is 3 mol% Eu2O3 = 52.7895 mg, and the mass of CsCl is 3 mol% CsCl = 50.508 mg. The percentages of the compounds are molar percentages.

[0043] Example 27: Under the same conditions, the mass of KAlSi3O8 is 2783.483 mg, the mass of Eu2O3 is 3 mol% Eu2O3 = 52.7895 mg, and the mass of CsCl is 5 mol% CsCl = 84.18 mg. The percentages of the compounds are molar percentages.

[0044] Example 28: Under the same conditions, the mass of KAlSi3O8 is 2783.483 mg, the mass of Eu2O3 is 3 mol% Eu2O3 = 52.7895 mg, and the mass of CsCl is 7 mol% CsCl = 117.852 mg. The percentages of the compounds are molar percentages.

[0045] Example 29: Under the same conditions, the mass of KAlSi3O8 is 2783.483 mg, the mass of Eu2O3 is 3 mol% Eu2O3 = 52.7895 mg, and the mass of CsCl is 9 mol% CsCl = 151.524 mg. The percentages of the compounds are molar percentages.

[0046] Example 30: Under the same conditions, the mass of KAlSi3O8 is 2783.483 mg, the mass of Eu2O3 is 3 mol% Eu2O3 = 52.7895 mg, and the mass of CsCl is 11 mol% CsCl = 185.196 mg. The percentages of the compounds are molar percentages.

[0047] Based on the phosphor doping concentration gradient, the KAlSi3O8:3 mol%Eu ratio in the technical solution is... 2+ xmol%M+ (M + Li + Na + 、Rb + Cs + For x ≤ 11.0, the photoluminescence properties of the phosphors are compared as shown in Tables 1, 2, 3, 4, and 5:

[0048] Table 1

[0049] Table 2

[0050] Table 3

[0051] Table 4

[0052] Table 5 As shown in Tables 1, 2, 3, 4, and 5, the KAlSi3O8 prepared using the technical solution has a 3 mol%Eu content of 3 mol%Eu. 2+ xmol%M + (M + Li + Na + 、Rb + Cs + When x ≤ 11.0, the phosphor exhibits significant changes in photoluminescence properties, specifically: 1) a significant red shift in the emission peak, with the peak wavelength changing from the initial 456 nm to 544 nm (cyan band); 2) a marked broadening of the half-width at half-maximum (FWHM), increasing from the initial 172 nm to 193 nm, resulting in a change in the KAlSi3O8:3mol%Eu 2+ 11 mol%Rb + The spectrum of phosphors covers the blue, cyan, and green light bands.

[0053] Figure 1 (KAlSi3O8: x mol%Li + KAlSi3O8: y mol%Na + KAlSi3O8: m mol%Rb + The XRD pattern of the sample is used as a key control experiment in this invention to illustrate the effect of using only a charge compensator (without introducing Eu²⁺). + The effect of different types of potassium feldspar on the crystal structure of the matrix was investigated. This was achieved through a systematic comparison of different types of potassium feldspar (Li).+ Na + 、Rb + From the XRD patterns of M and different concentrations of charge compensator doped with XRD, it can be clearly observed that: as M... + With increasing ion doping concentration, the characteristic diffraction peaks of potassium feldspar (KAlSi3O8) gradually weakened, accompanied by the appearance and enhancement of characteristic peaks of leucite (KAlSi2O6). This indicates that the introduction of the charge compensator itself can induce a structural phase transition from potassium feldspar to leucite, providing a basis for further understanding Eu²⁺. + With M + The "two-phase coexistence" mechanism in co-doped systems provides an initial reference for structural evolution.

[0054] See Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 It can be seen that the multiphase Eu obtained in this invention 2+ By doping with blue-cyan phosphor, phosphor powder with good dispersibility, no agglomeration, and smooth particle surface was obtained. XRD results show that the synthesized phosphor sample exhibits good dispersibility and no agglomeration with the addition of Li. + Na + 、Rb + Cs + Increasing the concentration of the four charge compensators resulted in a phase transition, which altered the crystal structure. Part of the potassium feldspar (KAlSi3O8) transformed into leucite (KAlSi2O6), ultimately revealing that the sample contained 3 mol% Eu of KAlSi3O8. 2+ 11 mol% Li + KAlSi3O8: 3mol%Eu 2+ 11 mol% Na + KAlSi3O8: 3mol%Eu 2+ 11 mol%Rb + KAlSi3O8: 3 mol%Eu 2+ 11 mol%Cs + The sample was a multiphase material in which potassium feldspar and leucite coexisted. See Figure 2 , Figure 3 and Figure 4 It can be seen that with the addition of Li + Na + 、Rb + Cs + Increased charge compensator concentration: 1) Luminous intensity first increases and then decreases; 2) Red shift occurs, and the color changes from blue to bluish-cyan; 3) Full width at half maximum (FWHM) increases, from 172nm to 193nm. Secondly, KAlSi3O8: 3mol%Eu 2+ 1 mol% Na + The white LED device obtained by packaging commercial red powder has an excellent color rendering index (Ra=95.5) and color coordinates (0.2994, 0.314) that are very close to standard white light (0.3333, 0.3333).

[0055] Based on the packaging process of white LEDs, the KAlSi3O8:3mol%Eu ratio in the technical solution is used... 2+ 1 mol% Na + Table 6 compares the phosphors used for white LED packaging with those using cyan phosphors in recent years.

[0056] Table 6 As shown in Table 4, the mainstream cyan phosphors currently require multiple phosphors to be combined and packaged to achieve white LEDs. This not only increases the complexity of the process, but also affects the device performance due to the difficulty in controlling the ratio. In contrast, reducing the types of phosphors used in packaging can simplify the production process and effectively reduce costs.

[0057] Based on the performance parameters of white LEDs, the KAlSi3O8:3mol%Eu ratio in the technical solution will be used. 2+ 1 mol% Na + The performance parameters are compared with those of cyan phosphors in recent years, as shown in Table 7:

[0058] Table 7 As shown in Table 7, the KAlSi3O8 developed in this invention has a 3mol%Eu content of 3 mol%Eu. 2+ 1 mol% Na + The phosphor exhibits unique cyan emission characteristics, and its ultra-wide half-width at half-maximum (HWHM) allows it to cover a wider spectral range, thus enabling white light emission with only a single phosphor. LED devices encapsulated with this phosphor demonstrate excellent performance, with a color rendering index as high as 95.5 and color coordinates (0.2994, 0.314) close to the standard white light value. This superior performance stems from the excellent spectral continuity provided by its wide spectral characteristics, and the effective compensation of cyan emission for spectral gaps; the synergistic effect of these two factors achieves high-quality white light output.

[0059] Based on the phosphor preparation process, the KAlSi3O8:3mol%Eu ratio in the technical solution is... 2+ 1 mol% Na + The preparation process is compared with existing cyan phosphor preparation processes in recent years, as shown in Table 8:

[0060] Table 8 As shown in Table 8, compared with the complex formulations of existing technologies that require multiple raw materials, this invention innovatively selects natural potassium feldspar (KAlSi3O8), europium trioxide (Eu2O3), lithium carbonate (Li2CO3), sodium carbonate (Na2CO3), rubidium carbonate (Rb2CO3), and cesium chloride (CsCl) as co-doped raw material systems. This not only greatly simplifies the preparation process but also significantly reduces production costs by leveraging the resource advantages of natural potassium feldspar.

[0061] This invention discloses a KAlSi3O8: 3 mol%Eu 2+ xmol%M + And M + Li + Na + 、Rb + Cs + , 1.0≤ x ≤11.0, Multiphase Phosphor and its Preparation Method. This material uses natural potassium feldspar (KAlSi3O8, 95%), high-purity europium trioxide (Eu2O3, 99.99%), high-purity lithium carbonate (Li2CO3, 99.99%), high-purity sodium carbonate (Na2CO3, 99.99%), high-purity rubidium carbonate (Rb2CO3, 99.99%), and high-purity cesium chloride (CsCl, 99.99%) from the Altay region of Xinjiang as raw materials. The process involves Eu... 2+ And Li + Na + 、Rb + Cs + These charge-compensating agents induced a partial transformation of the potassium feldspar phase into leucite (KAlSi2O6), successfully constructing a potassium feldspar-leucite biphase coexistence system. This preparation process not only simplifies the traditional synthesis of the leucite phase but also fully leverages the cost advantages of natural minerals. The resulting biphase phosphor combines the excellent properties of both phases, exhibiting significantly improved luminescence performance. When applied to white LED packaging, it effectively supplements the cyan luminescent component, achieving high-quality white light output with a high color rendering index while simplifying the process.

[0062] Utilizing the inherent properties of potassium feldspar, by incorporating Eu... 2+ And Li + Na + 、Rb + Cs +These charge compensators cause some potassium feldspar (KAlSi3O8) to be converted into leucite (KAlSi2O6). Thus, through the sintering process of natural potassium feldspar, a multiphase material in which potassium feldspar and leucite coexist can be finally prepared.

[0063] This phosphor features a simple preparation process, enabling the synthesis of the leucite (KAlSi2O6) phase, which typically requires complex processes, using a simple method. Ultimately, it achieves a unique structure where potassium feldspar (KAlSi3O8) and leucite (KAlSi2O6) coexist in two phases.

[0064] This dual-phase composite structure combines the advantages of two crystalline phases, significantly improving the luminescence performance of the phosphor.

[0065] The white LED device based on this phosphor encapsulation not only simplifies the traditional encapsulation process, but also makes up for the lack of the key cyan light-emitting component, while achieving excellent performance with a high color rendering index.

[0066] Figure 7 This invention plays a crucial role in structural elucidation. It intuitively reveals the essential differences between the two phases in terms of atomic arrangement, coordination environment, and lattice symmetry, providing direct crystallographic evidence for understanding the core innovative mechanism of "doping-induced controllable phase transition".

[0067] From a materials design perspective, although potassium feldspar and leucite both belong to the silicate system, their silicon-oxygen framework connection methods, alkali metal ion occupancy, and crystal field strength are significantly different. Figure 7 The structural differences presented are precisely due to the introduction of Eu² in this invention. + and charge-compensating ions of different radii (Li + Na + 、Rb + Cs + This provides the structural basis for the gradual transformation from potassium feldspar to leucite. This phase transition process occurs within... Figures 2 to 6 The XRD spectrum systematically confirmed that as the doping concentration increased, the characteristic diffraction peaks of leucite gradually strengthened, indicating that the crystal lattice was reconstructed and eventually a stable composite structure with two phases coexisting was formed.

[0068] Figure 8 The value shown is KAlSi3O8:3mol%Eu² + 1 mol% Na +Emission spectra of a white LED device encapsulated with phosphor, a 365 nm near-ultraviolet chip, and commercial red phosphor. The figure clearly shows that this phosphor system exhibits significant and continuous broadband emission in the blue-cyan spectral region (approximately 480–500 nm), effectively filling the cyan band gap commonly found in traditional white LED spectra. This spectral characteristic not only enhances the overall spectral continuity and coverage but also significantly improves the device's color rendering performance.

[0069] from Figure 8 The text further elucidates two major advantages of this material in practical packaging applications: First, its strong emission in the blue-cyan band and efficient matching with near-ultraviolet excitation indicate that Eu² + The local crystal field environment in this dual-phase structure is effectively optimized, which is beneficial to improving the excitation efficiency and thermal stability of the phosphor. Secondly, the broadband emission characteristics enable it to achieve full-spectrum white light output when combined with a single red phosphor, avoiding the reabsorption effect and ratio control problem in multi-phosphor systems. This achieves synergistic optimization from both material design and device process perspectives.

[0070] therefore, Figure 8 This study not only visually demonstrates the spectral contribution of the phosphor in LED packaging, but also, from the perspective of material-device coupling, confirms the feasibility and advancement of using charge compensators to modulate phase structure and achieve a two-phase coexistence system in improving luminescent performance and simplifying packaging processes. This result provides important experimental evidence and design ideas for the future development of high-performance, low-cost broadband fluorescent materials.

[0071] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention.

Claims

1. A multiphase Eu 2+ And a blue-cyan phosphor doped with a charge compensator, characterized in that, Multiphase Eu 2+ The general formula for the molar ratio of charge compensator-doped blue-cyan phosphor is: KAlSi3O8:3mol%Eu 2+ xmol%M + M + For Li + Na + 、Rb + Cs + Any one of four charge-compensating ions, and the M + The ionic radius and K + There are controllable differences, and 1.0≤x≤11.

0.

2. The multiphase Eu according to claim 1 2+ And a blue-cyan phosphor doped with a charge compensator, characterized in that: The mass of KAlSi3O8 weighed is 2783.483 mg, and the mass of Eu2O3 weighed is: 3 mol%Eu2O3=52.7895 mg. The percentages of the compounds are molar percentages.

3. The multiphase Eu according to claim 2 2+ And a blue-cyan phosphor doped with a charge compensator, characterized in that: The mass of Li2CO3 weighed out in the following proportions: 1 mol% Li₂CO₃ = 3.66945 mg; 3 mol% Li₂CO₃ = 11.0835 mg; 5 mol% Li₂CO₃ = 18.4725 mg; 7 mol% Li₂CO₃ = 25.8615 mg; 9 mol% Li₂CO₃ = 33.2505 mg; 11 mol% Li₂CO₃ = 40.6395 mg, and the percentage of the compound is in molar percentage.

4. The multiphase Eu according to claim 2 2+ And a blue-cyan phosphor doped with a charge compensator, characterized in that: The mass of Na2CO3 weighed out in the following proportions: 1 mol% Na₂CO₃ = 5.2995 mg; 3 mol% Na₂CO₃ = 15.8985 mg; 5 mol% Na₂CO₃ = 26.4975 mg; 7mol% Na₂CO₃ = 37.0965 mg; 9 mol% Na₂CO₃ = 47.6955 mg; 11 mol% Na2CO3 = 58.2945 mg, and the percentage of compounds is in molar percentage.

5. The multiphase Eu according to claim 2 2+ And a blue-cyan phosphor doped with a charge compensator, characterized in that: The masses of Rb₂CO₃ weighed out in the following proportions: 1 mol% Rb₂CO₃ = 11.5395 mg; 3 mol% Rb₂CO₃ = 34.6185 mg; 5 mol% Rb₂CO₃ = 57.6975 mg; 7 mol% Rb₂CO₃ = 80.7765 mg; 9 mol% Rb₂CO₃ = 103.8555 mg; 11 mol% Rb2CO3 = 126.9345 mg, and the percentage of the compound is in molar percentage.

6. The multiphase Eu according to claim 2 2+ And a blue-cyan phosphor doped with a charge compensator, characterized in that: The masses of CsCl are weighed out in the following proportions: 1 mol% CsCl = 16.836 mg; 3 mol% CsCl = 50.508 mg; 5 mol% CsCl = 84.18 mg; 7 mol% CsCl = 117.852 mg; 9 mol% CsCl = 151.524 mg; 11 mol% CsCl = 185.196 mg, and the percentage of the compound is in molar percentage.

7. A multiphase Eu according to any one of claims 1-6 2+ The method for preparing blue-cyan phosphor doped with charge compensator is characterized in that, Includes the following steps: Step 1: Material preparation; including natural potassium feldspar, lithium carbonate powder, sodium carbonate powder, rubidium carbonate powder, europium oxide powder, and cesium chloride powder. Step 2: Set the gradient stoichiometric molar ratio as: KAlSi3O8: 3mol%Eu 2+ xmol%M + And 1≤ x ≤11.0; Calculate the amount of material according to the stoichiometric molar ratio, and weigh the natural potassium feldspar, lithium carbonate powder, sodium carbonate powder, rubidium carbonate powder, europium trioxide powder and cesium chloride powder in equal proportions using an electronic balance. The mass of KAlSi3O8 weighed is always 2783.483 mg, and the mass of Eu2O3 weighed is always 3 mol%Eu2O3=52.7895 mg. Weigh Li2CO3, Na2CO3, Rb2CO3 and CsCl according to batch. Step 3: Place the weighed raw materials into an agate mortar and grind them thoroughly for 20 minutes; Step 4: Transfer the ground raw materials sequentially into the alumina crucible; Step 5: Place the crucible in the box furnace and provide a reducing atmosphere for sintering the sample in a carbon powder environment, and sinter at the set temperature; Step 6: After the sintered sample has cooled to room temperature, remove it and grind it into powder for 20 minutes.

8. The multiphase Eu according to claim 7 2+ The method for preparing blue-cyan phosphor doped with charge compensator is characterized in that, In step five, the reducing agent in the reducing atmosphere is carbon powder; the box furnace is set to a heating rate of 5℃ / min and a holding time of 1200℃ for 3 hours.

9. The multiphase Eu as described in any one of claims 1-6 2+ The application of blue-cyan phosphors doped with charge compensation agents in LED light-emitting devices.

10. An LED light-emitting device, characterized in that, The device includes a blue-cyan phosphor, a near-ultraviolet chip, and a red phosphor, wherein the blue-cyan phosphor comprises the multiphase Eu phosphor as described in any one of claims 1-6. 2+ And blue-cyan phosphors doped with charge compensators.

Images