Phosphate red fluorescent powder as well as preparation method and application thereof

Abstract

The invention discloses phosphate red fluorescent powder as well as a preparation method and application thereof. The chemical composition of the phosphate red fluorescent powder is Na < 1-x > Mg < y > P < 1-y > O < 4 >: xEu < 2 + >, wherein M is selected from at least one of Si, Ge, Sn, Ti, Zr and Hf; x is the molar coefficient of Eu < 2 + >, and x is more than or equal to 0.001 and less than Y is the molar coefficient of M, and y is more than or equal to 0.001 and less than or equal to 0.3. The phosphate red fluorescent powder disclosed by the invention can be effectively excited by ultraviolet light or blue light with the wave band of 300-500nm, and red fluorescence with the maximum wavelength at 620nm is emitted.

Description

Technical Field

[0001] The invention relates to a phosphate red fluorescent powder and a preparation method and application thereof. Background Art

[0002] With the continuous development of society, energy crisis and environmental pollution are becoming increasingly serious. Countries around the world are accelerating the development of low-carbon economy and actively advocating energy conservation and emission reduction. In the field of lighting, white light LED (light-emitting diode), as the fourth generation of solid-state lighting technology, has become the mainstream development direction of the market due to its advantages of high luminous efficiency, long service life, energy saving and environmental protection, safety and reliability.

[0003] At present, the main solutions for achieving white light LED lighting include the following: (1) Blue light LED chips excite yellow phosphors. The white light obtained in this way has high luminous efficiency, but the color rendering index is low. (2) Red, green and blue LED chips are integrated and packaged. The white light color rendering index achieved in this way is high, but the overall circuit design is relatively complex and the cost is high. (3) Ultraviolet / purple light chips excite red, green and blue phosphors. The white light obtained by this method has a high color rendering index and the lamp cost is also low. It is a very ideal lighting solution. Among them, red phosphor, as a key light conversion material, can effectively improve the color rendering index of white light LED lamps and optimize the spectral color temperature. Therefore, the development of red phosphor materials excited by ultraviolet / blue light is of great significance for improving the lighting quality of commercial white light LEDs and creating a healthy and comfortable lighting environment.

[0004] At present, the red phosphors used in commercial white light LEDs are mainly nitride phosphors, which have high luminous efficiency and good stability, but the synthesis conditions are relatively harsh and the production cost is also high. On the other hand, the excitation spectrum of nitride red phosphors is wide, and the overlapping area with the emission spectrum of green or yellow phosphors is relatively high. If they are packaged together into white light LED lamps, there will be a significant reabsorption effect between different phosphors, resulting in a decrease in the light efficiency of the lamps. In contrast, the phosphate red phosphor system not only has excellent luminescent properties and good chemical stability, but also has a simple synthesis process and low production cost. Based on a reasonable component design strategy, further regulating and optimizing the luminous efficiency and luminescent characteristics of phosphate red phosphors will effectively promote their application in the field of LED lighting.

[0005] CN107312542A discloses a europium-doped red phosphor based on phosphate, and its chemical composition is: the chemical formula is Ca3Gd 1-x Na(PO4)3F:xEu, where 0.1≤x≤0.8. This red phosphor contains F, which has a great impact on the environment.

[0006] CN115322780A discloses a red phosphor, whose general chemical formula is NaMg1-x Zn x PO4:0.03Eu 2+ ; Wherein, 0<x≤0.12. The red phosphor mainly emits orange-red light. Wherein, Eu 2+ To Na + Unequal substitution will lead to charge imbalance in the system and produce more oxygen vacancy defects inside the crystal, which will quench the fluorescence. The luminescence properties of this phosphate red phosphor need to be further improved.

[0007] CN1544575A discloses a phosphate red phosphor for light emitting diodes having the following chemical formula: AB 1-x PO4:xEu 3+ or A 1+y B 1-x-y PO4:xEu 3+ , where A is Li + , Na + and K + One or more of; B is Mg 2+ , Ca 2 + , Sr. 2+ and Ba 2+ One or more of the above, and 0<x≤1, 0≤y<1. The red phosphor has a narrow-band emission. If it is applied to white light LED lighting, the improvement of the color rendering index of the lamp is very limited. Summary of the invention

[0008] In view of this, one object of the present invention is to provide a phosphate red phosphor, which can emit red fluorescence with a maximum wavelength of 620nm under the excitation of ultraviolet light or blue light. Another object of the present invention is to provide a method for preparing the above-mentioned phosphate red phosphor. Another object of the present invention is to provide the use of the above-mentioned phosphate red phosphor. Another object of the present invention is to provide a white light LED light source assembly. Another object of the present invention is to provide a white light LED device.

[0009] The present invention adopts the following technical solutions to achieve the above-mentioned purpose.

[0010] On the one hand, the present invention provides a phosphate red phosphor, the chemical composition of which is Na 1-x MgM y P 1-y O4:xEu 2+ ; Wherein, M is selected from at least one of Si, Ge, Sn, Ti, Zr, Hf; x is Eu 2+ The molar coefficient of M is 0.001≤x≤0.3; y is the molar coefficient of M, 0.001≤y≤0.3.

[0011] According to the phosphate red phosphor of the present invention, preferably, M is selected from at least one of Si, Ge, Ti, Zr and Hf.

[0012] According to the phosphate red phosphor of the present invention, preferably, 0.005≤x≤0.2, 0.005≤y≤0.2.

[0013] On the other hand, the present invention also provides a method for preparing the above-mentioned phosphate red phosphor, comprising the following steps:

[0014] 1) providing raw materials according to the chemical composition of the phosphate red phosphor and preparing raw material powders, and mixing the raw material powders to obtain mixed powders;

[0015] 2) pre-sintering the mixed powder in a reducing atmosphere at 300-600° C. to obtain a pre-sintered powder material;

[0016] 3) Sintering the pre-sintered powder material obtained in step 2) in a reducing atmosphere at 900-1300° C. to obtain a phosphate red phosphor.

[0017] According to the preparation method of the present invention, preferably, the raw materials include sodium oxide or an inorganic salt of sodium, magnesium oxide or an inorganic salt of magnesium, oxide or an inorganic salt of M, oxide or phosphate of phosphorus, and europium oxide or an inorganic salt of europium.

[0018] According to the preparation method of the present invention, preferably, the inorganic salt of sodium is sodium carbonate, the inorganic salt of magnesium is magnesium carbonate, and the inorganic salt of europium is europium carbonate.

[0019] According to the preparation method of the present invention, preferably, the phosphate is ammonium phosphate.

[0020] On the other hand, the present invention also provides the use of the above-mentioned phosphate red phosphor in white light LEDs, wherein the phosphate red phosphor exhibits broadband red light emission under the excitation of ultraviolet light or blue light, and the emission wavelength range is 500 to 850 nm.

[0021] On the other hand, the present invention further provides a white light LED light source assembly, comprising the above-mentioned phosphate red phosphor, yellow phosphor and an ultraviolet or blue light LED chip.

[0022] In yet another aspect, the present invention further provides a white light LED device, comprising the above-mentioned white light LED light source assembly.

[0023] The phosphate red phosphor of the present invention can be effectively excited by ultraviolet light or blue light in the wavelength range of 300-500nm, and emits red fluorescence with a maximum wavelength of 620nm. The phosphate red phosphor of the present invention can be used together with yellow phosphor to produce high-quality white light. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The XRD diagrams of the phosphate red phosphors of Examples 1 to 4 and Comparative Example 1;

[0025] Figure 2 The excitation spectrum and emission spectrum of the phosphate red phosphor of Example 1 and Comparative Example 1 are shown; wherein (a) is the excitation spectrum and (b) is the emission spectrum;

[0026] Figure 3 The excitation spectrum and emission spectrum of the phosphate red phosphor of Example 2 and Comparative Example 1 are shown; wherein (a) is the excitation spectrum and (b) is the emission spectrum;

[0027] Figure 4 The excitation spectrum and emission spectrum of the phosphate red phosphor of Example 3 and Comparative Example 1 are shown; wherein (a) is the excitation spectrum and (b) is the emission spectrum;

[0028] Figure 5 The excitation spectrum and emission spectrum of the phosphate red phosphor of Example 4 and Comparative Example 1 are shown; wherein (a) is the excitation spectrum, and (b) is the emission spectrum.

[0029] Figure 6 The electroluminescence spectra of the LED devices packaged with the phosphor of Experimental Example 1 are shown in FIG. 1 ; wherein (a) is the electroluminescence spectrum and color rendering index of the LED device packaged with a single YAG:Ce yellow phosphor, and (b) is the electroluminescence spectrum and color rendering index of the white light LED device packaged with the phosphate red phosphor prepared in Example 1 and the commercial YAG:Ce yellow phosphor. DETAILED DESCRIPTION

[0030] The present invention is further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto.

[0031] <Phosphate red phosphor>

[0032] The excitation spectrum of the phosphate red phosphor of the present invention is in the range of 300 to 500 nm. Under the excitation of ultraviolet or blue light, it can emit red fluorescence with a maximum wavelength at 620 nm, and has good compatibility with ultraviolet or blue light LED chips. The excitation spectrum of the phosphate red phosphor of the present invention has a low overlap with the emission spectrum of the yellow phosphor. When it is used simultaneously with the yellow phosphor, the reabsorption effect between the different phosphors is small. By mixing the above two phosphors, an ideal white light can be obtained under the excitation of an ultraviolet or blue light LED chip.

[0033] The phosphate red phosphor of the present invention has a chemical composition of Na 1-x MgMy P 1-y O4:xEu 2+ ; Wherein, M is selected from at least one of Si (silicon), Ge (germanium), Sn (tin), Ti (titanium), Zr (zirconium), Hf (hafnium); x is Eu 2+ (divalent europium ion), 1-x is the molar coefficient of Na (sodium), 0.001≤x≤0.3; y is the molar coefficient of M, 1-y is the molar coefficient of P (phosphorus), 0.001≤y≤0.3.

[0034] According to one embodiment of the present invention, M can be selected from at least one of Si, Ge, Sn, Ti, Zr, and Hf; preferably at least one of Si, Ge, Ti, Zr, and Hf; more preferably at least one of Si, Ge, Zr, and Hf.

[0035] According to one embodiment of the present invention, x may be 0.001≤x≤0.3, preferably 0.005≤x≤0.2, and more preferably 0.005≤x≤0.1. y may be 0.001≤x≤0.3, preferably 0.005≤x≤0.2, and more preferably 0.005≤x≤0.1.

[0036] The present invention controls the element ratio within the above range, which is beneficial to the preparation of phosphor powder. 4+ P 5+ Non-equivalent substitutions were made to maintain the conservation of overall charge, repairing the Eu 2+ Replace Na + The oxygen vacancy defects generated after the phosphor is removed greatly improve the luminescence intensity of the phosphor, which can ensure that the phosphor presents broadband red light emission under the excitation of ultraviolet light or blue light. It is beneficial to produce high-quality white light when the phosphate red phosphor is used together with the yellow phosphor.

[0037] <Preparation method>

[0038] The preparation method of the above phosphate red phosphor includes a mixing step, a pre-sintering step and a sintering step, which will be described in detail below.

[0039] Mixing steps

[0040] According to the chemical composition of the phosphate red phosphor, raw materials are provided and made into raw material powders, and the raw material powders are mixed to obtain mixed powders.

[0041] According to one embodiment of the present invention, the raw materials may include sodium oxide or an inorganic salt of sodium, magnesium oxide or an inorganic salt of magnesium, oxide or an inorganic salt of M, oxide or phosphate of phosphorus, and europium oxide or an inorganic salt of europium.

[0042] Preferably, the inorganic salt of sodium is sodium carbonate. The inorganic salt of magnesium is magnesium carbonate. The inorganic salt of europium is europium carbonate. The phosphate is ammonium phosphate.

[0043] More preferably, the raw materials include sodium carbonate, magnesium oxide or magnesium carbonate, oxide of M, ammonium dihydrogen phosphate or diammonium hydrogen phosphate, and europium oxide.

[0044] The raw materials used in the present invention can be commercially available products or prepared by existing preparation methods, and are not particularly limited here. The purity of the raw materials of the present invention is at least industrial purity (99.9wt%).

[0045] Pre-sintering step

[0046] The mixed powder is pre-sintered in a reducing atmosphere to obtain a pre-sintered powder material.

[0047] According to one embodiment of the present invention, the reducing atmosphere of the present invention refers to a reducing atmosphere formed by introducing a mixed gas of hydrogen and a protective gas. The protective gas can be selected from at least one of nitrogen and an inert gas; preferably at least one of nitrogen, helium, neon, and argon; more preferably at least one of nitrogen, helium, and argon. The volume ratio of hydrogen to protective gas can be 2 to 10:90 to 98; preferably 3 to 9:91 to 97; more preferably 5 to 8:92 to 95.

[0048] According to one embodiment of the present invention, the temperature is raised from room temperature (same as 25°C) to the pre-sintering temperature at a heating rate of 2-15°C / min, preferably 3-12°C / min, and more preferably 5-10°C / min. The pre-sintering temperature may be 300-600°C; preferably 300-550°C; more preferably 350-550°C. The pre-sintering time may be 3-6h; preferably 3.5-5.5h; more preferably 4-5h.

[0049] Reasonable pre-sintering conditions are conducive to the complete decomposition of the easily decomposable salts in the raw materials.

[0050] Sintering steps

[0051] The pre-sintered phosphate red phosphor is sintered in a reducing atmosphere to obtain the phosphate red phosphor.

[0052] According to one embodiment of the present invention, the reducing atmosphere of the present invention refers to an atmosphere formed by introducing a mixed gas of hydrogen and a protective gas. The protective gas may be selected from at least one of nitrogen and an inert gas; preferably selected from at least one of nitrogen, helium, neon, and argon; more preferably selected from at least one of nitrogen, helium, and argon. The volume ratio of hydrogen to protective gas may be 2 to 10:90 to 98; preferably 3 to 9:91 to 97; more preferably 5 to 8:92 to 95.

[0053] According to one embodiment of the present invention, the temperature is raised from the pre-sintering temperature to the sintering temperature at a heating rate of 2 to 15°C / min, preferably 3 to 12°C / min, and more preferably 5 to 10°C / min. The sintering temperature may be 900 to 1300°C, preferably 950 to 1250°C, and more preferably 950 to 1200°C. The sintering time may be 2 to 6 hours, preferably 2.5 to 5.5 hours, and more preferably 3 to 5 hours.

[0054] In the present invention, both pre-sintering and sintering can be performed in any high temperature resistant equipment known in the art, and are not particularly limited herein. For example, they can be performed in a high temperature reduction sintering furnace.

[0055] In the present invention, the obtained phosphate red phosphor is cooled after sintering. The cooling can be achieved by any cooling method known in the art, which is not particularly limited here. For example, it can be natural cooling or air cooling.

[0056] According to one embodiment of the present invention, the prepared phosphate red phosphor can be ground and sieved, and the average particle size D of the phosphate red phosphor particles after grinding and sieving is 50 It may be 20 to 100 μm, preferably 30 to 80 μm, and more preferably 40 to 60 μm.

[0057] In the present invention, grinding can be achieved by any grinding method known in the art, and is not particularly limited here. For example, it can be performed using an agate mortar or a ball mill. Screening can be performed by any screening method known in the art, and is not particularly limited here. For example, it can be performed using an ultra-fine mesh screen or a vibrating screen.

[0058] Reasonable sintering conditions combined with the composition of phosphor raw materials are conducive to promoting the growth of phosphor crystals and making its structure more complete, thereby improving the luminous efficiency and thermal stability of the phosphor, and ensuring that the phosphor can emit bright red light under ultraviolet or blue light excitation.

[0059] The preparation method of the present invention adopts M 4+ P 5+ Non-equivalent substitution can effectively repair Eu 2+ Replace Na + The charge imbalance problem generated maintains the balance of the overall charge and eliminates the oxygen vacancy defects inside the crystal, thereby significantly improving the luminescence characteristics of the phosphate red phosphor. The prepared phosphate red phosphor has a simple synthesis process and excellent luminescence performance. The preparation process of the present invention is simple and suitable for application in the field of white light LED lighting.

[0060] <Purpose>

[0061] The present invention also provides the use of the phosphate red fluorescent powder in white light LEDs.

[0062] According to one embodiment of the present invention, the phosphate red phosphor exhibits broadband red light emission under the excitation of ultraviolet light or blue light, and the excitation wavelength range may be 300 to 500 nm; preferably 325 to 475 nm; more preferably 350 to 450 nm.

[0063] According to one embodiment of the present invention, the phosphate red phosphor emits strong red fluorescence at an emission wavelength of 600-675 nm, preferably 600-655 nm, and more preferably 620-625 nm when excited by ultraviolet light or blue light.

[0064] The phosphate red phosphor and the yellow phosphor of the present invention are used simultaneously in a white light LED to obtain white light of higher quality.

[0065] <White LED light source components>

[0066] The present invention also provides a white light LED light source assembly, comprising the above-mentioned phosphate red phosphor, yellow phosphor and an ultraviolet or blue light LED chip.

[0067] According to another embodiment of the present invention, the yellow emitting phosphor may be a commercial yellow phosphor, preferably a YAG:Ce phosphor.

[0068] According to one embodiment of the present invention, the mass ratio of the phosphate red phosphor to the yellow phosphor may be 1:(0.5-5); preferably 1:(1-3); more preferably 1:(1-2).

[0069] The phosphate red phosphor of the present invention can be used together with the yellow phosphor to produce high-quality white light. The color rendering index Ra of the white light can be at least 59, preferably at least 59.2, and more preferably at least 59.5.

[0070] The phosphate red phosphor of the present invention can generate high-quality white light when used together with the yellow phosphor.

[0071] <White light LED devices>

[0072] The present invention also provides a white light LED device, comprising the above white light LED light source assembly.

[0073] <Test method>

[0074] XRD measurement: The test was carried out using an X'Pert PRO X-ray diffractometer produced by Panalytical.

[0075] Excitation spectrum and emission spectrum measurement: The test was carried out using FSL1000 fluorescence spectrometer produced by Edinburgh Instruments.

[0076] White light LED device spectrum measurement: The test is carried out using the Yuanfang HAAS-2000 high-precision rapid spectroradiometer.

[0077] <Ingredients>

[0078] The raw materials in the following examples are all commercially available products unless otherwise specified.

[0079] Comparative Example 1

[0080] Preparation of phosphate red phosphor:

[0081] According to Na 0.97 MgPO4:0.03Eu 2+ The chemical composition provides raw materials Na2CO3, MgO, NH4H2PO4 and Eu2O3, and the above raw materials are fully ground in a mortar for 30 minutes to make raw material powders, and the raw material powders are mixed to obtain mixed powders.

[0082] The mixed powder was placed in a crucible, and the crucible was placed in a high-temperature sintering furnace. A mixed gas with a volume ratio of hydrogen to nitrogen of 5:95 was introduced, and the temperature was raised from room temperature to 400°C at a heating rate of 5°C / min, and heat-treated at 400°C for 4 hours for pre-sintering. After the pre-sintering was completed, the temperature was further raised to 1100°C at a heating rate of 5°C / min, and sintered at 1100°C for 4 hours, and then naturally cooled to room temperature, and the sintered product was taken out and ground and sieved to obtain a phosphate red phosphor.

[0083] Take 10g of the phosphate red phosphor prepared in this comparative example and conduct corresponding tests:

[0084] XRD results are shown in Figure 1 .

[0085] The results of excitation and emission spectra are shown in Figures 2 to 5 .

[0086] Example 1

[0087] Preparation of phosphate red phosphor:

[0088] According to Na 0.97 MgSi 0.03 P 0.97 O4:0.03Eu 2+The chemical composition of the present invention is to provide raw materials of Na2CO3, MgO, SiO2, NH4H2PO4 and Eu2O3, and grind the raw materials in a mortar for 30 minutes to prepare raw material powders, and mix the raw material powders to obtain mixed powders. The remaining operations are the same as those in Comparative Example 1.

[0089] Take 10g of the phosphate red phosphor prepared in this example and perform the corresponding tests:

[0090] XRD results are shown in Figure 1 .

[0091] The results of excitation and emission spectra are shown in Figure 2 shown.

[0092] like Figure 1 As shown in the figure, the XRD diffraction peaks of the phosphate red phosphor prepared in Example 1 and the main diffraction peaks of the phosphate red phosphor prepared in Comparative Example 1 are basically consistent, indicating that the use of Si 4+ P 5+ Non-equivalent substitution does not cause changes in the main crystal structure. Figure 2 It can be seen that the excitation spectrum and emission spectrum of the phosphate red phosphor prepared in Example 1 are significantly improved compared with the phosphate red phosphor prepared in Comparative Example 1. 4+ P 5+ Unequal substitution can effectively repair Eu 2+ Replace Na + The charge imbalance problem generated thereby enhances the luminescent properties of the phosphate red phosphor. The excitation spectrum of the phosphate red phosphor prepared in Example 1 is in the range of 300 to 500 nm, preferably 350 to 450 nm, indicating that it can be effectively excited by ultraviolet light or blue light. The phosphate red phosphor can emit the strongest red light at an emission wavelength of 620 nm.

[0093] Example 2

[0094] Preparation of phosphate red phosphor:

[0095] According to Na 0.97 MgGe 0.03 P 0.97 O4:0.03Eu 2+ The chemical composition of the present invention is to provide raw materials Na2CO3, MgO, GeO2, NH4H2PO4 and Eu2O3, and grind the raw materials in a mortar for 30 minutes to prepare raw material powders, and mix the raw material powders to obtain mixed powders. The remaining operations are the same as those in Comparative Example 1.

[0096] Take 10g of the phosphate red phosphor prepared in this example and perform the corresponding tests:

[0097] XRD results are shown in Figure 1 .

[0098] The results of excitation and emission spectra are shown in Figure 3 shown.

[0099] like Figure 1 As shown, the XRD diffraction peaks of the phosphate red phosphor prepared in Example 2 are basically consistent with the main diffraction peaks of the phosphate red phosphor prepared in Comparative Example 1, indicating that the use of Ge 4+ P 5+ Non-equivalent substitution does not cause changes in the main crystal structure. Figure 3 It can be seen that the phosphate red phosphor prepared in Example 2 has significantly improved intensities of excitation spectrum and emission spectrum compared to the phosphate red phosphor prepared in Comparative Example 1, and the excitation spectrum range is 300-500nm, preferably 350-450nm, indicating that it can be effectively excited by ultraviolet light or blue light. The phosphate red phosphor can emit the strongest red light at an emission wavelength of 620nm.

[0100] Example 3

[0101] Preparation of phosphate red phosphor:

[0102] According to Na 0.97 MgZr 0.03 P 0.97 O4:0.03Eu 2+ The chemical composition of the present invention is to provide raw materials Na2CO3, MgO, ZrO2, NH4H2PO4 and Eu2O3, and grind the raw materials in a mortar for 30 minutes to prepare raw material powders, and mix the raw material powders to obtain mixed powders. The remaining operations are the same as those in Comparative Example 1.

[0103] Take 10g of the phosphate red phosphor prepared in this example and perform the corresponding tests:

[0104] XRD results are shown in Figure 1 .

[0105] The results of excitation and emission spectra are shown in Figure 4 shown.

[0106] like Figure 1 As shown in the figure, the XRD diffraction peaks of the phosphate red phosphor prepared in Example 3 are basically consistent with the main diffraction peaks of the phosphate red phosphor prepared in Comparative Example 1, indicating that the use of Zr 4+ P 5+ Non-equivalent substitution does not cause changes in the main crystal structure. Figure 4It can be seen that the phosphate red phosphor prepared in Example 3 has significantly improved intensities of excitation spectrum and emission spectrum compared to the phosphate red phosphor prepared in Comparative Example 1, and the excitation spectrum range is 300-500nm, preferably 350-450nm, indicating that it can be effectively excited by ultraviolet light or blue light. The phosphate red phosphor can emit the strongest red light at an emission wavelength of 620nm.

[0107] Example 4

[0108] Preparation of phosphate red phosphor:

[0109] According to Na 0.97 MgHf 0.03 P 0.97 O4:0.03Eu 2+ The chemical composition of the present invention is to provide raw materials Na2CO3, MgO, HfO2, NH4H2PO4 and Eu2O3, and grind the raw materials in a mortar for 30 minutes to prepare raw material powders, and mix the raw material powders to obtain mixed powders. The remaining operations are the same as those in Comparative Example 1.

[0110] Take 10g of the phosphate red phosphor prepared in this example and perform the corresponding tests:

[0111] XRD results are shown in Figure 1 .

[0112] The results of excitation and emission spectra are shown in Figure 5 shown.

[0113] like Figure 1 As shown in the figure, the XRD diffraction peaks of the phosphate red phosphor prepared in Example 4 are basically consistent with the main diffraction peaks of the phosphate red phosphor prepared in Comparative Example 1, indicating that the use of Hf 4+ P 5+ Non-equivalent substitution does not cause changes in the main crystal structure. Figure 5 It can be seen that the phosphate red phosphor prepared in Example 4 has significantly improved intensities of excitation spectrum and emission spectrum compared with the phosphate red phosphor prepared in Comparative Example 1, and the excitation spectrum range is 300-500nm, preferably 350-450nm, indicating that it can be effectively excited by ultraviolet light or blue light. The phosphate red phosphor can emit the strongest red light at an emission wavelength of 620nm.

[0114] Application Experiment Example 1

[0115] 0.25 g of the phosphate red phosphor prepared in Example 1 was mixed with 0.25 g of commercial YAG:Ce yellow phosphor, and 1 g of organic silica gel (m A胶 :mB胶 =1:4) to prepare a slurry, then apply the mixed slurry on commercial blue LED lamp beads, and finally place the applied lamp beads in a high-temperature oven to cure the organic silica gel to obtain a white light LED light source assembly. A white light LED device is prepared using the white light LED light source assembly.

[0116] The electroluminescence spectrum and color rendering index of the white light LED device were measured. The results are as follows: Figure 6 shown.

[0117] Compared with LED devices encapsulated with a single YAG:Ce yellow phosphor, the white light LED device encapsulated with the phosphate red phosphor of the present invention and the commercial YAG:Ce yellow phosphor has a higher color rendering index and better lighting quality. The experimental results show that the phosphate red phosphor of the present invention can improve the color rendering index of white light LED lamps and has a very ideal application prospect in the field of LED lighting.

[0118] The present invention is not limited to the above-mentioned embodiments. Without departing from the essential content of the present invention, any deformation, improvement and substitution that can be conceived by those skilled in the art shall fall within the scope of the present invention.

Claims

1. A phosphate red phosphor, characterized in that: Its chemical composition is Na 1-x MgM y P 1-y O4:xEu 2+ ; Wherein, M is selected from at least one of Si, Ge, Sn, Ti, Zr, Hf; x is Eu 2+ The molar coefficient of M is 0.001≤x≤0.3; y is the molar coefficient of M, 0.001≤y≤0.

3.

2. The phosphate red phosphor according to claim 1, characterized in that: M is selected from at least one of Si, Ge, Ti, Zr and Hf.

3. The phosphate red phosphor according to claim 1, characterized in that: 0.005≤x≤0.2, 0.005≤y≤0.

2.

4. A method for preparing the phosphate red phosphor according to any one of claims 1 to 3, comprising the following steps: 1) providing raw materials according to the chemical composition of the phosphate red phosphor and preparing raw material powders, and mixing the raw material powders to obtain mixed powders; 2) pre-sintering the mixed powder in a reducing atmosphere at 300-600° C. to obtain a pre-sintered powder material; 3) Sintering the pre-sintered powder material obtained in step 2) in a reducing atmosphere at 900-1300° C. to obtain a phosphate red phosphor.

5. The preparation method according to claim 4, characterized in that: The raw materials include sodium oxide or an inorganic salt of sodium, magnesium oxide or an inorganic salt of magnesium, oxide or an inorganic salt of M, oxide or phosphate of phosphorus, and europium oxide or an inorganic salt of europium.

6. The preparation method according to claim 5, characterized in that: The inorganic salt of sodium is sodium carbonate, the inorganic salt of magnesium is magnesium carbonate, and the inorganic salt of europium is europium carbonate.

7. The preparation method according to claim 4, characterized in that: The phosphate is ammonium phosphate.

8. Use of the phosphate red phosphor according to any one of claims 1 to 3 in a white light LED, characterized in that: The phosphate red phosphor exhibits broadband red light emission under the excitation of ultraviolet light or blue light, and the emission wavelength range is 500-850nm.

9. A white light LED light source assembly, characterized in that: The white light LED light source assembly comprises the phosphate red phosphor, yellow phosphor and an ultraviolet or blue light LED chip as described in any one of claims 1 to 3.

10. A white light LED device, characterized in that: The white light LED device comprises the white light LED light source assembly according to claim 9.

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