A calcium indium phosphate fluorescent matrix material and its preparation method and application

Abstract

The present invention belongs to the field of rare earth luminescent materials, and specifically discloses a calcium indium phosphate matrix material for phosphor, the chemical formula of which is Ca 3.6 In 3.6 (PO4)6. Furthermore, a method for preparing the calcium indium phosphate matrix material and its use in preparing fluorescent materials are also provided. This invention provides a novel calcium indium phosphate compound that can be used as a matrix material for phosphors. When doped with rare earth ions, it exhibits luminescent properties with high thermal stability.

Description

Technical field:

[0001] The present invention relates to the field of rare earth luminescent materials, in particular to a phosphate matrix material for rare earth phosphor and a preparation method thereof. Background technology:

[0002] Luminescent materials are materials that can absorb various forms of energy in response to external factors (such as charged particles, electrical energy, chemical energy, and electromagnetic waves). These materials transfer and convert the absorbed and stored energy into nonequilibrium light radiation. Luminescent materials can be applied in numerous fields, such as energy-saving lighting, anti-counterfeiting detection, information display, modern agriculture, national defense and military industry, security monitoring, optical temperature measurement, and assisted crop growth. Phosphors are generally made by doping a matrix material with activator ions, and sometimes sensitizers are used to enhance the luminescence efficiency. These phosphors exhibit extrinsic luminescence. A very small number of phosphors emit light on their own, without the need for doping, and thus exhibit intrinsic luminescence. The matrix is ​​an essential component of phosphors, acting as a carrier for the activator and a key factor directly influencing their luminescence properties. Since 1938, phosphate materials have garnered considerable research interest. Phosphate-based fluorescent materials not only have strong absorption of vacuum ultraviolet light, but can also transfer the absorbed energy to activator ions such as rare earths, thereby improving the chemical properties of rare earth ions. At the same time, the phosphate matrix has numerous crystal structures and abundant cationic sites, which can provide diverse crystal fields and coordination environments for the incorporated rare earth ions. Therefore, when the activator ions in the phosphate matrix are excited, the phosphate phosphor can exhibit rich and excellent luminescence properties, and has considerable application prospects in the fields of lighting and display. From the development of the first generation of phosphors to the present, many researchers have conducted a lot of research on phosphor matrices and prepared a series of rare earth phosphate phosphors that can be used in different fields, such as Na3Sc2(PO4)3:Ce 3+ ,Tb 3+ 、(Ca,Mg)2P2O7:Eu 2+ 、α-Ca(PO3)2:Eu 2+ / Mn 2+ 、Ca9Y(PO4)7:Eu 3+ At present, the most widely studied and applied phosphate luminescent materials are orthophosphate (PO4). n and pyrophosphate (P2O7) nThe phosphate matrix itself is non-luminescent, but it matches the charge transfer between rare earth ions and coordinated oxygen, effectively transferring energy to the luminescent center, resulting in strong absorption in the vacuum ultraviolet and near-ultraviolet regions, which is radiated as light. The fluorescent matrix material is one of the main factors affecting the performance of phosphors. Recently, the main approaches to exploring new fluorescent materials have been doping and modification of previously reported compounds or studying a series of isostructural compounds of more mature matrices, while the exploration of new matrix materials is relatively rare. From the discovery of a new compound to the synthesis of a pure sample as possible, its composition ratio, temperature, and other factors require extensive experimental exploration. Furthermore, not all compounds are suitable as phosphor matrix materials. Phosphor matrix materials are required to have good thermal and chemical stability, absorption in the ultraviolet region, and high transmittance in the visible region. Therefore, those skilled in the art generally believe that the process of exploring new matrix materials is difficult and challenging. Summary of the invention:

[0003] The purpose of the present invention is to provide a novel calcium indium phosphate fluorescent matrix material.

[0004] Another object of the present invention is to provide a simple process for preparing the above calcium indium phosphate fluorescent material.

[0005] The third object of the present invention is to provide a method for using the calcium indium phosphate fluorescent matrix material in preparing fluorescent materials.

[0006] A calcium indium phosphate fluorescent matrix material, the chemical formula of which is Ca 3.6 In 3.6 (PO4)6.

[0007] The present invention has found that Ca 3.6 In 3.6 (PO4)6 is a brand-new compound with a brand-new crystal structure. This brand-new compound is beneficial for obtaining fluorescent materials with excellent luminescence properties and thermal stability as a matrix material for rare earth phosphors. In addition, since the matrix has two unique cation vacancy configurations, it has good universality, more suitable excitation conditions and a large modification space as a fluorescent matrix material for the preparation of phosphors, and has good industrial application prospects.

[0008] The study found that the calcium indium phosphate fluorescent matrix material crystal belongs to the triclinic system. The space group and unit cell parameters are α=110.9440°, β=101.3650°, γ=108.2350°, Z=1.

[0009] The unit cell of the calcium indium phosphate fluorescent matrix material has a total of 19 crystallographic positions: Ca occupies 2 2i positions (one of which has a 20% cation vacancy), In occupies 2 2i positions (one of which has a 20% cation vacancy), P occupies 3 2i positions, and O occupies 12 2i positions.

[0010] The present invention also provides a method for preparing the calcium indium phosphate fluorescent matrix material, comprising mixing a calcium source, an indium source, and a phosphate source according to the stoichiometric ratio to obtain a mixture, and subjecting the mixture to multi-stage sintering (N-stage sintering) to obtain the fluorescent matrix material.

[0011] In the multi-stage sintering process, the sintering temperature of the first stage is 600-700°C, and the sintering temperature of other stages (excluding the first stage, i.e., the second to Nth stages) is 1100-1200°C.

[0012] The method of the present invention mixes a calcium source, an indium source, and a phosphate source according to the stoichiometric ratio of the chemical formula Ca, In, and P, and innovatively performs multi-stage sintering within the temperature range, thereby obtaining a calcium indium phosphate fluorescent matrix material with good crystallization performance and less impurities.

[0013] The calcium source is calcium oxide or a calcium salt that can be converted into calcium oxide; preferably at least one of CaO, calcium nitrate, calcium carbonate, calcium sulfate, and organic acid calcium (such as calcium acetate).

[0014] The indium source is indium oxide or indium salt that can be converted into indium oxide; preferably at least one of In2O3, indium nitrate, indium carbonate, indium hydroxide, and organic acid indium (such as indium carboxylate).

[0015] The phosphate source is at least one of phosphoric acid, diammonium hydrogen phosphate, and ammonium dihydrogen phosphate.

[0016] The preparation method of the present invention preferably adopts a wet chemistry-solid phase synthesis method.

[0017] Preferably, a wet chemical method is used for mixing, wherein the steps are: mixing a calcium source, an indium source, and a phosphate source in a stoichiometric ratio, dissolving them with acid, adding a water-soluble binder, and then evaporating the solvent in the system to obtain the mixture.

[0018] The acid solution is an aqueous solution of acid that can dissolve the raw materials (calcium source, indium source, phosphate source); preferably, it is a nitric acid solution.

[0019] The water-soluble binder is at least one of starch, dextrin, polyvinyl alcohol, and carboxymethyl cellulose.

[0020] The amount of water-soluble binder used is 2 to 3 times the weight of the calcium source.

[0021] Research conducted by the present invention has found that using a multi-stage sintering process within the temperature range can improve the crystallization properties of the resulting material and reduce impurities. In the present invention, the number of stages N in the multi-stage sintering process is greater than or equal to 2, preferably 2 to 3. For example, the multi-stage sintering process includes a first stage sintering, a second stage sintering, ..., and an Nth stage sintering.

[0022] Preferably, the first stage sintering time is 10 to 12 hours, and the other stage sintering time (second to N stage sintering) is 20 to 24 hours.

[0023] Preferably, the heating rate in each stage is 3-5°C / min.

[0024] After each stage of sintering is carried out at the sintering temperature for the time specified, the material is then cooled to room temperature in the furnace, ground, and then heated to the sintering temperature for the next stage of heat preservation sintering; after the final stage of sintering, the material is cooled and ground to obtain the phosphate fluorescent matrix material for calcium indium rare earth phosphor.

[0025] The room temperature is, for example, 15 to 35°C.

[0026] The present invention discloses a preferred method for preparing a calcium indium phosphate fluorescent matrix material. Appropriate amounts of CaCO₃, In₂O₃, and NH₄H₂PO₄ are weighed into a beaker at a Ca:In:P molar ratio of 3.6:3.6:6. A strong acid (such as nitric acid) is added, and the raw materials are dissolved by heating and stirring. After the solution becomes clear, a polyvinyl alcohol aqueous solution (wherein the amount of PEG is 2-3 times that of the CaCO₃) is added. The mixture is heated and stirred until completely evaporated to dryness, and the dried material is ground uniformly. A first stage sintering is performed at 600-700°C, followed by cooling to room temperature and grinding. A second stage sintering is performed at 1100-1200°C, followed by cooling and grinding to obtain the final product. High-purity samples can be obtained within this sintering temperature range and time. XRD data for different temperatures are shown in the accompanying figures.

[0027] The heating rate of the first stage sintering step is preferably 3-5°C / min; the temperature of the first stage sintering step is preferably 600-650°C; the holding time of the first stage sintering step is preferably 10-12h;

[0028] The heating rate of the second stage sintering step is preferably 3-5°C / min; the temperature of the second stage sintering step is preferably 1150-1200°C; and the holding time of the second stage sintering step is preferably 20-24h.

[0029] The preferred preparation method uses a wet chemical-solid phase synthesis process to obtain high-purity Ca 3.6 In3.6 (PO4)6 phosphor uses phosphate matrix material.

[0030] The X-ray powder diffraction data of the matrix material of the present invention were compared with the International Center for Diffraction Data (ICDD) Powder Diffraction Database (PDF-4+2011) and the Inorganic Crystal Structure Database (ICSD) using MDIjade 6.0 software, indicating that the material belongs to the triclinic system. Space group. The inventors used Fullprof software and Rietveld full-spectrum fitting methods to analyze and refine the crystal structure, and determined that the matrix structure of the present invention has a total of 19 crystallographic occupancy sites: Ca occupies two 2i positions (one of which has a 20% cation vacancy), In occupies two 2i positions (one of which has a 20% cation vacancy), P occupies three 2i positions, and O occupies 12 2i positions. This confirms that the matrix material of the present invention is a novel compound with an unreported crystal structure and related properties.

[0031] The present invention also provides an application of the calcium indium phosphate fluorescent matrix material as a matrix material for preparing a fluorescent material.

[0032] The matrix material is used to prepare a fluorescent material by doping Ca and / or In in the calcium indium phosphate fluorescent matrix material with fluorescent ions.

[0033] The fluorescent ions can be any existing ions that can excite fluorescence.

[0034] The present invention also provides a fluorescent material derived from the calcium indium phosphate fluorescent matrix material of the present invention, the chemical formula of which is Ca 3.6 (In 1-x M x ) 3.6 (PO4)6; M is at least one element selected from Ce, Dy, Eu, Tb, Tm, Mn, Cr, and Bi; and x is 0.01 to 0.05. The present invention has discovered that by doping M, for example, by doping Eu, a red LED light component can be obtained.

[0035] The preparation method of the fluorescent material is similar to the preparation method of the calcium indium phosphate fluorescent matrix material. For example, the fluorescent material is prepared according to the stoichiometric ratio of the chemical elements and then subjected to the multi-stage sintering to obtain the fluorescent material.

[0036] Beneficial effects of the present invention

[0037] The present invention successfully prepares for the first time a novel phosphate compound that can serve as a phosphor matrix material. The compound contains indium, which has properties and ionic size similar to those of rare earth, transition metal, or bismuth elements, and a similar coordination with oxygen. The rare earth, transition metal, or bismuth element serves as the phosphor matrix material. This calcium indium phosphate matrix material prepared by the present invention has not been reported in the prior art. The process of the present invention has the advantages of a relatively simple preparation process. The calcium indium phosphate fluorescent matrix described in the present invention facilitates the mass production of fluorescent materials with high thermal stability. Description of the drawings:

[0038] Figure 1 The XRD patterns of Example 1 and Comparative Examples 1-3 are compared;

[0039] Figure 1 The unmarked diffraction peaks correspond to the Ca 3.6 In 3.6 (PO4)6 diffraction peak. As can be seen from the figure, the XRD patterns of the samples prepared in Example 1 and Comparative Examples 1-3 all contain Ca 3.6 In 3.6 (PO4)6 diffraction peak, but the products prepared in Comparative Examples 1 to 3 are two-phase / three-phase mixed phases, and only the product prepared in Example 1 is the Ca 3.6 In 3.6 The pure phase sample of (PO4)6 phosphor matrix material fully proves that the ingredient ratio has a significant impact on the synthetic purity of the sample.

[0040] Figure 2 The CaO-InO 1.5 -PO 2.5 Partial phase diagram of the ternary system; the component of Example 1 is recorded as 1, and the components of Comparative Examples 1-3 are recorded as 2, 3, and 4.

[0041] The phase diagram is based on the XRD phase analysis results of Example 1 and Comparative Examples 1-3, and is drawn in the composition triangle according to the phase law. 3.6 In 3.6 The component point of the (PO4)6 ternary compound and the two-phase and three-phase regions corresponding to this component in Comparative Examples 1 to 3.

[0042] Figure 3 The XRD patterns of the three samples of Example 1, Example 2 and Example 3 are compared;

[0043] All the diffraction peaks in the XRD pattern of Example 1 belong to Ca 3.6 In 3.6 (PO4)6. By Figure 3It can be seen that the diffraction peaks of the samples prepared in Example 2 and Example 3 are consistent with the positions of the diffraction peaks of Example 1 and no new peaks appear. Comparison of the diffraction patterns of Example 1, Example 2 and Example 3 proves that Ca 3.6 In 3.6 (PO4)6 can synthesize a high-purity phase with good crystallinity within the final calcination temperature range of 1100-1200℃, and the crystallinity of the sample improves with increasing temperature.

[0044] Figure 4 Example 1 at room temperature 400-2000cm -1 Infrared spectra in wavenumber range;

[0045] Depend on Figure 4 It can be seen that the area between 500 and 700 cm -1 The absorption peak is due to the asymmetric bending vibration of OPO, 700~1800cm -1 It is caused by the symmetric and asymmetric stretching of OPO. According to the infrared spectrum analysis results, Ca 3.6 In 3.6 (PO4)6 contains isolated [PO4] 3- group.

[0046] Figure 5 The XRD patterns of the four samples of Example 1 and Examples 4 to 6 are compared;

[0047] The products obtained in Examples 4 to 6 are single-phase, and all diffraction peaks in their XRD patterns belong to Ca 3.6 In 3.6 (PO4)6. By Figure 5 It can be seen that the diffraction peaks of the products obtained in Example 4, Example 5, and Example 6 are consistent with the position of the diffraction peaks of Example 1, and no new miscellaneous peaks appear.

[0048] Figure 6 The Ca obtained in Examples 4 to 6 3.6 (In 1-x Eu x ) 3.6 Excitation spectrum of (PO4)6 phosphor;

[0049] Depend on Figure 6 It can be seen that by fixing the emission wavelength at 613nm, the excitation spectra of the phosphors prepared in Examples 4 to 6 are measured. From the figure, it can be seen that within the range of 200 to 550nm, excitation peaks appear at 200-280nm, 318nm, 360nm, 380nm, 392nm, and 463nm. Among them, the highest excitation peak intensity is located in the range of 200-280nm, followed by the excitation peak at 392nm. 3.6 (In1-x Eu x ) 3.6 The intensity of the excitation spectrum of (PO4)6 phosphor increases with the 3+ The intensity of the excitation peak in Example 6 is significantly higher than that in Examples 4 and 5.

[0050] Figure 7 The Ca obtained in Examples 4 to 6 3.6 (In 1-x Eu x ) 3.6 Emission spectrum of (PO4)6 phosphor;

[0051] according to Figure 7 The characteristic excitation peaks of Examples 4 to 6 were measured under the excitation wavelength of 392 nm to measure the emission spectra of the phosphor samples of Examples 4 to 6. Figure 7 It can be seen that in the range of 575-725 nm, emission peaks appear at 590 nm, 613 nm, 654 nm, and 702 nm, among which the emission peak at 613 nm occupies a dominant position. 5 D0- 7 F2 emission is dominant. The emission peak intensities of Examples 4 to 6 vary with the 3+ The doping concentration increases; among them, the intensity of the emission peak of the phosphor of Example 6 is significantly stronger than that of the phosphors of Examples 4 and 5.

[0052] Figure 8 Example 6 at different temperatures 5 D0- 7 A graph showing the relationship between F2 emission intensity and temperature;

[0053] Depend on Figure 8 It can be seen that Example 6 exhibits weak thermal quenching. When the temperature reaches 150°C, the emission intensity remains at 89.7% of that at room temperature. When the temperature reaches 250°C, the emission intensity remains at 69.9% of that at room temperature. 3+ ,Tb 3+ 、Ba3In(PO4)3:Eu 3+ 、Sr3In(PO4)3:Eu 3+ Compared with other phosphors, Ca 3.6 (In 1-x Eu x ) 3.6 (PO4)6 has better thermal stability.

[0054] Figure 9 is the CIE diagram of Example 6;

[0055] The chromaticity coordinates of the phosphor of Example 6 were analyzed using CIE colorimetric software, and the chromaticity coordinates of Example 6 were determined to be (0.6486, 0.3511), which is located in the red light region.

[0056] Commercial WLEDs are made of blue GaN chips covered with Y3Al5O 12 :Ce 3+ The red component in the phosphor is one of the key factors in optimizing LEDs, so many researchers have invested a lot of energy in red phosphors. Figures 7-9 It can be seen that Ca 3.6 (In 1-x Eu x ) 3.6 (PO4)6 phosphor can be excited by ultraviolet and near-ultraviolet light, with the optimal excitation wavelength between 350-410nm. It has good luminescent color and can maintain stable red light emission at high temperature. It has potential application prospects in WLED.

[0057] Figure 10 The XRD patterns of the four samples of Example 1 and Examples 7 to 9 are compared;

[0058] The product obtained in Example 1 is a single phase, and all the diffraction peaks in its XRD spectrum belong to Ca 3.6 In 3.6 (PO4)6. By Figure 10 It can be seen that the diffraction peaks of the products obtained in Examples 7 to 9 are consistent with the positions of the diffraction peaks of Example 1, and no new miscellaneous peaks appear.

[0059] Figure 11 Ca obtained in Examples 7 to 9 3.6 (In 1-x Dy x ) 3.6 Excitation spectrum of (PO4)6 phosphor;

[0060] By fixing the characteristic emission wavelength of Dy at 577 nm, the excitation spectra of the phosphors prepared in Examples 7 to 9 were measured. It can be seen from the figure that an excitation peak appears in the range of 250 to 500 nm. The narrow peak between 250 and 500 nm is Dy 3+ ion ff transition characteristic excitation peak; the excitation peak intensity of Examples 7 to 9 increases with the 3+ The doping concentration first increases and then decreases, wherein the intensity of the excitation spectrum of the phosphor prepared in Example 8 is significantly higher than those of the phosphors prepared in Examples 7 and 9.

[0061] Figure 12Ca obtained in Examples 7 to 9 3.6 (In 1-x Dy x ) 3.6 Emission spectrum of (PO4)6 phosphor;

[0062] according to Figure 12 The characteristic excitation peaks of Examples 7 to 9 are fixed at an excitation wavelength of 349 nm. The emission spectra of the phosphors prepared in Examples 7 to 9 are measured. As can be seen from the figure, emission peaks appear at 484 nm, 577 nm, and 660 nm in the range of 400 to 700 nm. The yellow light emission peak at 577 nm is the strongest peak. The peak intensity increases first and then decreases with the increase of doping concentration. 3+ When it occupies a position deviated from the symmetry center, the yellow emission peak dominates. 4 F 9 / 2 → 6 H 13 / 2 From the figure, we can see that the intensity of the yellow light emission peak at 577nm is higher than that of the blue light emission peak at 484nm, and the yellow light emission peak occupies a dominant position, indicating that in Ca 3.6 (In 1-x Dy x ) 3.6 Dy in (PO4)6 phosphor 3+ Occupies a position deviated from the symmetric center. 3+ The doping concentration first increases and then decreases, wherein the intensity of the emission spectrum of the phosphor prepared in Example 8 is significantly higher than those of the phosphors prepared in Examples 7 and 9.

[0063] Figure 13 Example 8 at different temperatures 4 F 9 / 2 → 6 H 13 / 2 Graph showing the relationship between emission intensity and temperature;

[0064] Depend on Figure 13 It can be seen that Example 8 exhibits an abnormal anti-quenching property, and the emission intensity first increases and then decreases with the increase of temperature. The luminescence intensity of Example 8 does not decay in the temperature range of 25 to 200°C. When the temperature reaches 150°C, the emission intensity remains at 106.2% of the room temperature; when the temperature reaches 200°C, the emission intensity can still remain at 100.3% of the room temperature. After that, the luminescence intensity begins to decrease with the increase of temperature. When the temperature reaches 300°C, the emission intensity still remains at 71.8% of the room temperature. 3.6 (In 1-x Dy x ) 3.6 (PO4)6 phosphor has excellent thermal stability at high temperatures.

[0065] Figure 14 is the CIE diagram of Example 8;

[0066] The chromaticity coordinates of the phosphor of Example 8 were analyzed using CIE colorimetric software, and the chromaticity coordinates of Example 8 were determined to be (0.3733, 0.4091), which is located in the yellow-white light region.

[0067] Depend on Figures 11-14 It can be seen that Dy 3+ Activated yellow-emitting Ca 3.6 (In 1-x Dy x ) 3.6 (PO4)6 phosphor is excited in the near-ultraviolet band and shows an abnormal anti-thermal quenching property at high temperature, which means that Ca 3.6 (In 1- x Dy x ) 3.6 (PO4)6 phosphor has good application potential in the WLED field.

[0068] Thermal stability of phosphors is an important factor in WLED applications. Since the probability of non-radiative transitions increases with increasing temperature, the luminous intensity of phosphors generally decreases with increasing operating temperature. In normal working environments, phosphors usually operate below 150°C, so phosphors need to maintain stable emission capabilities at high temperatures. Figures 5 to 14 It can be seen that Ca 3.6 In 3.6 (PO4)6 doped with Eu 3+ 、Dy 3+ Rare earth ions can be excited in the near-ultraviolet band and show excellent thermal stability at high temperatures, which means that the new compound Ca 3.6 In 3.6 (PO4)6 as a phosphor matrix material has significant advantages in WLED applications. Specific implementation method:

[0069] The following examples are intended to further illustrate the present invention, but are not intended to limit the present invention.

[0070] Example 1: Ca 3.6 In 3.6 Preparation of (PO4)6 phosphor matrix

[0071] Weigh CaCO3, In2O3, and NH4H2PO4 according to the stoichiometric ratio of elements (Ca, In, P ratio is 3.6:3.6:6), then add nitric acid to dissolve the raw materials. After the solution is clarified, add polyvinyl alcohol solution (wherein the polyvinyl alcohol is twice the weight of calcium oxide), heat and stir until completely evaporated, place the beaker in a drying oven to dry, and grind evenly; then perform two-stage sintering (the first stage sintering temperature is 600℃, keep warm for 12 hours, then cool to room temperature with the furnace, and grind for 10 minutes; the second stage sintering temperature is 1200℃, keep warm for 24 hours, then cool to room temperature with the furnace, the first step sintering heating rate is 3℃ / min, and the second step sintering heating rate is 5℃ / min). Take out the sintered sample and grind it to obtain Ca 3.6 In 3.6 (PO4)6 phosphor matrix. After structural refinement, its unit cell parameters are determined to be: α=110.9440°, β=101.3650°, γ=108.2350°, Z=1.

[0072] Comparative Example 1: Preparation of a sample with a Ca:In:P stoichiometric ratio of 28.7:26.5:44.8

[0073] CaCO3, In2O3, and NH4H2PO4 were prepared according to the element ratio of Ca, In, and P of 30.2:25.1:44.7, and the remaining steps were the same as in Example 1.

[0074] Comparative Example 2: Preparation of a sample with a Ca:In:P stoichiometric ratio of 34.7:31.2:34.1

[0075] CaCO3, In2O3, and NH4H2PO4 are prepared according to the element ratio of Ca, In, and P of 34.7:31.2:34.1, and the remaining steps are the same as those in Example 1.

[0076] Comparative Example 3: Preparation of a sample with a Ca:In:P stoichiometric ratio of 33:22:44

[0077] CaCO3, In2O3, and NH4H2PO4 are prepared in an elemental ratio of Ca, In, and P of 33:22:44, and the remaining steps are the same as those in Example 1.

[0078] Example 2: Ca 3.6 In 3.6 Preparation of (PO4)6 phosphor matrix

[0079] CaCO3, In2O3, and NH4H2PO4 are prepared in a stoichiometric ratio of Ca, In, and P of 3.6:3.6:6. The sintering temperature in the second step is 1100°C, and the remaining steps are the same as in Example 1.

[0080] Example 3: Ca 3.6 In 3.6 Preparation of (PO4)6 phosphor matrix

[0081] CaCO3, In2O3, and NH4H2PO4 are prepared in a stoichiometric ratio of Ca, In, and P of 3.6:3.6:6. The sintering temperature in the second step is 1150°C, and the remaining steps are the same as in Example 1.

[0082] Example 4: Ca 3.6 (In 0.99 Eu 0.01 ) 3.6 Preparation of (PO4)6 phosphor

[0083] Weigh CaCO3, In2O3, Eu2O3, and NH4H2PO4 and mix them according to the stoichiometric ratio of the phosphor elements (Ca, In, Eu, and P element ratio of 3.6:3.564:0.036:6). The remaining steps are the same as in Example 1.

[0084] Example 5: Ca 3.6 (In 0.97 Eu 0.03 ) 3.6 Preparation of (PO4)6 phosphor

[0085] Weigh CaCO3, In2O3, Eu2O3, and NH4H2PO4 and mix them according to the stoichiometric ratio of the phosphor elements (Ca, In, Eu, and P element ratio of 3.6:3.492:0.108:6). The remaining steps are the same as in Example 1.

[0086] Example 6: Ca 3.6 (In 0.95 Eu 0.05 ) 3.6 Preparation of (PO4)6 phosphor

[0087] Weigh CaCO3, In2O3, Eu2O3, and NH4H2PO4 and mix them according to the stoichiometric ratio of the phosphor elements (Ca, In, Eu, and P element ratio of 3.6:3.420:0.180:6). The remaining steps are the same as in Example 1.

[0088] Example 7: Ca 3.6 (In 0.99 Dy 0.01 ) 3.6 Preparation of (PO4)6 phosphor

[0089] Weigh CaCO3, In2O3, Dy2O3, and NH4H2PO4 and mix them according to the stoichiometric ratio of the phosphor elements (Ca, In, Tb, and P element ratio of 3.6:3.564:0.036:6). The remaining steps are the same as in Example 1.

[0090] Example 8: Ca 3.6 (In 0.97 Dy 0.02 ) 3.6 Preparation of (PO4)6 phosphor

[0091] Weigh CaCO3, In2O3, Dy2O3, and NH4H2PO4 and mix them according to the stoichiometric ratio of the phosphor elements (Ca, In, Tb, P element ratio of 3.6:3.528:0.072:6). The remaining steps are the same as in Example 1.

[0092] Example 9: Ca 3.6 (In 0.95 Dy 0.05 ) 3.6 Preparation of (PO4)6 phosphor

[0093] CaCO3, In2O3, Dy2O3, and NH4H2PO4 were weighed and mixed according to the stoichiometric ratio of the phosphor elements (Ca, In, Tb, and P element ratio of 3.6:3.420:0.180:6). The remaining steps were the same as in Example 1.

Claims

1. A calcium indium phosphate fluorescent matrix material, characterized in that: Its chemical formula is Ca 3.6 In 3.6 (PO4)6; The calcium indium phosphate fluorescent matrix material belongs to the triclinic system and has a space group of (No.2), the unit cell parameters are a=6.4954(1) Å, b=9.2129(1) Å, c=9.2608(1) Å, α=110.9440(6) °, β=101.3650(8) °, γ=108.2350(8) °, V=460.80 Å 3 , Z=1; The calcium indium phosphate fluorescent matrix material has a total of 19 crystallographic positions, among which Ca occupies 2 2i positions, one of which has 20% cation vacancies, In occupies 2 2i positions, one of which has 20% cation vacancies, P occupies 3 2i positions, and O occupies 12 2i positions.

2. A method for preparing the calcium indium phosphate fluorescent matrix material according to claim 1, characterized in that: A calcium source, an indium source, and a phosphate source are mixed in a stoichiometric ratio according to the chemical formula to obtain a mixture, and the mixture is sintered in multiple stages to obtain a mixture; In the multi-stage sintering process, the sintering temperature of the first stage is 600~700℃, and the sintering temperature of other stages is 1100~1200℃.

3. The method for preparing the calcium indium phosphate fluorescent matrix material according to claim 2, wherein: The calcium source is calcium oxide or a calcium salt that can be converted into calcium oxide; The indium source is indium oxide or indium salt that can be converted into indium oxide; The phosphate source is at least one of phosphoric acid, diammonium hydrogen phosphate, and ammonium dihydrogen phosphate.

4. The method for preparing the calcium indium phosphate fluorescent matrix material according to claim 3, wherein: The calcium source is at least one of CaO, calcium nitrate, calcium carbonate, calcium sulfate, and organic acid calcium; The indium source is at least one of In2O3, indium nitrate, indium carbonate, indium hydroxide, and organic acid indium; The phosphate source is at least one of phosphoric acid, diammonium hydrogen phosphate, and ammonium dihydrogen phosphate.

5. The method for preparing the calcium indium phosphate fluorescent matrix material according to claim 2, wherein: The wet chemical method is used for mixing, and the steps are: mixing a calcium source, an indium source, and a phosphate source in a stoichiometric ratio, dissolving them with acid, adding a water-soluble binder, and then evaporating the solvent in the system to obtain the mixture.

6. The method for preparing the calcium indium phosphate fluorescent matrix material according to claim 5, wherein: The water-soluble binder is at least one of starch, dextrin, polyvinyl alcohol, and carboxymethyl cellulose; The amount of water-soluble binder used is 2 to 3 times the weight of the calcium source.

7. The method for preparing the calcium indium phosphate fluorescent matrix material according to claim 2, wherein: During the multi-stage sintering process, after each stage of sintering is completed, it is cooled and ground before proceeding to the next stage of sintering; the sintering time for the first stage is 10~12 h, and the sintering time for other stages is 20~24 h; the heating rate for each stage is 3~5 ℃ / min.

8. A use of the calcium indium phosphate fluorescent host material according to claim 1, or the calcium indium phosphate fluorescent host material prepared by the preparation method according to any one of claims 2 to 7, characterized in that: As a base material, used to prepare fluorescent materials.

9. The use according to claim 8, characterized in that The fluorescent material is prepared by doping Ca or In in the calcium indium phosphate fluorescent matrix material with fluorescent ions.

10. A fluorescent material, characterized in that: The chemical formula is Ca 3.6 (In 1-x M x ) 3.6 (PO4)6; M is an element selected from Dy and Eu; x is 0.01~0.

05.

11. The fluorescent material according to claim 10, wherein x is 0.05.

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