Green fluorescent material excited by purple light as well as preparation method and application of green fluorescent material

Abstract

The invention relates to a green fluorescent material excited by purple light as well as a preparation method and application of the green fluorescent material. The chemical expression of the fluorescent material is CaSrLu (3.5-x) La0. 5O8: xCe < 3 + >, wherein x is more than or equal to 0.001 and less than or equal to 0.1. The fluorescent powder is wide-excitation green fluorescent powder and has the advantage of stable physicochemical properties, and meanwhile, the preparation process is simple, high temperature and high pressure are not needed, and industrial production is facilitated. The fluorescent powder disclosed by the invention can be completely well matched with an existing purple light chip, is excellent in light emitting performance, and has huge development potential in healthy lighting fields such as purple light excitation white light LEDs, purple light excitation type sunlight LEDs and purple light excitation full-spectrum LEDs.

Description

Technical Field

[0001] The invention belongs to the technical field of fluorescent material preparation, and in particular relates to a green fluorescent material excited by violet light, and a preparation method and application thereof. Background Art

[0002] LED is known as the fourth generation of green and environmentally friendly lighting sources. It has the advantages of energy saving, environmental protection, long life and small size. It is widely used in entertainment venues, exhibitions, exhibition halls and other places. Due to the development potential of white light LED, all countries have invested a lot of scientific research efforts to focus on the development of white light LED. At present, there are two main methods to achieve white light LED. One is to combine multi-color chips to achieve white light effect, but this method has complex circuits, high costs, and it is difficult to achieve continuous and uniform spectrum. The other is to achieve white light LED by adding multi-color phosphors to the chip. One is to add yellow phosphors to the blue light chip, but the spectrum of this method has obvious gullies, and the purple and red light spectra are missing, resulting in insufficient color rendering, unable to achieve full-spectrum lighting, and blue light hazards, which will cause irreversible damage to the human eye. Another way is to add red, green and blue multi-color phosphors to the purple light chip to achieve high color rendering, high light efficiency and adjustable color temperature of sunlight-like healthy lighting LED. As the core component of the fluorescent conversion type sunlight-like LED, the performance of phosphor directly determines the performance of the device such as luminous efficiency, color temperature, color rendering index and life.

[0003] Therefore, developing highly responsive phosphor materials for ultraviolet chips is very important for achieving healthy sunlight-like lighting. Currently, commercially available green phosphors include Ba2SiO4:Eu 2+ and β-SiAlON:Eu 2+ .Ba2SiO5:Eu 2+ There is a disadvantage of poor thermal stability, β-SiAlON:Eu 2+ The synthesis requires high temperature and high pressure conditions, and the synthesis cost is high. In addition, the optimal excitation of these two phosphors is in the ultraviolet light region, which is mismatched with the purple light chip. Therefore, the development of new green phosphors that are compatible with the purple light chip has important practical significance. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and to provide a violet light excited green light fluorescent material and a preparation method and application thereof.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] The present invention first provides a new type of green light fluorescent material excited by purple light. The chemical expression of the fluorescent material is CaSrLu 3.5-x La 0.5 O8:xCe 3+, where 0.001≤x≤0.1.

[0007] Further, x=0.005, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06 or 0.07.

[0008] Furthermore, when x>0.1, the doping concentration is too high, which is not conducive to luminescence.

[0009] In one embodiment of the present invention, the violet light-excited green fluorescent material can emit green light with a spectral range of 440 to 700 nm and a central wavelength of 528 nm under violet light excitation, which is broadband emission and can effectively absorb light in the wavelength range of 270 to 480 nm.

[0010] Preferably, the chemical expression of the fluorescent material is CaSrLu 3.5-x La 0.5 O8:xCe 3+ , 0.005≤x≤0.07.

[0011] More preferably, the chemical expression of the fluorescent material is CaSrLu 3.495 La 0.5 O8: 0.005Ce 3+ ,CaSrLu 3.49 La 0.5 O8:0.01Ce 3+ ,CaSrLu 3.48 La 0.5 O8: 0.02Ce 3+ ,CaSrLu 3.47 La 0.5 O8: 0.03Ce 3+ ,CaSrLu 3.46 La 0.5 O8: 0.04Ce 3+ ,CaSrLu 3.45 La 0.5 O8: 0.05Ce 3+ ,CaSrLu 3.44 La 0.5 O8: 0.06Ce 3+ ,CaSrLu 3.43 La 0.5 O8: 0.07Ce 3+ .

[0012] Furthermore, the excitation spectrum range of the green fluorescent material excited by the violet light covers 270 to 480 nm.

[0013] Furthermore, the emission spectrum of the green fluorescent material excited by violet light covers a range of 440 to 700 nm.

[0014] In one embodiment of the present invention, the green fluorescent material excited by violet light is a powdery material.

[0015] Furthermore, the excitation spectrum range of the green fluorescent material excited by violet light covers 270 to 480 nm, preferably 355 to 450 nm.

[0016] Furthermore, the emission spectrum of the green fluorescent material excited by violet light covers a range of 440 to 700 nm.

[0017] Furthermore, the green fluorescent material excited by violet light can achieve strong green light emission with the emission center located at 528 nm under the excitation of ultraviolet or violet light of 270 to 480 nm.

[0018] Furthermore, the violet light-excited green light fluorescent material is an oxide-based phosphor, which has outstanding advantages such as stable physical and chemical properties, simple preparation, low cost, and broad application prospects. Its emission wavelength includes 440 to 700 nm, which matches a variety of violet light and ultraviolet light excitation chips. The optimal excitation wavelength is at 420 nm, which can match commercial violet light chips.

[0019] The present invention further provides a method for preparing the green fluorescent material excited by violet light, comprising the following steps:

[0020] (1) weighing raw material powders of a cerium source compound, a calcium source compound, a strontium source compound, a lutetium source compound, and a lanthanum source compound according to the stoichiometric ratio of the chemical formula, grinding the raw material powders to uniformly mix them, and obtaining a mixture as the ground raw material;

[0021] (2) placing the ground raw material powder into an alumina crucible, and then calcining the alumina crucible containing the raw material in an air atmosphere, and then naturally cooling it to room temperature to obtain a precursor;

[0022] (3) The mixed product (precursor) obtained after calcination in step (2) is fully ground again, and then placed in a reducing atmosphere of hydrogen and nitrogen mixture for sintering (reduction sintering), and then cooled to room temperature to finally obtain a green fluorescent material excited by violet light.

[0023] In one embodiment of the present invention, in step (1), the calcium source compound is CaCO3, the strontium source compound is SrCO3, the lutetium source compound is Lu2O3, the lanthanum source compound is La2O3, and the cerium source compound is CeO2.

[0024] In one embodiment of the present invention, in step (1), the grinding time of the raw material powder is 5 to 120 minutes.

[0025] Furthermore, in step (2), the calcination temperature is 200 to 1000° C., and the calcination time is 5 to 24 hours.

[0026] In some embodiments of the present invention, the sintering temperature in the air atmosphere in step (2) is 500-800° C., and the sintering time is 5-20 h.

[0027] Furthermore, in step (3), during reduction sintering, the reducing atmosphere is selected from CO gas or a mixed gas of H2 and N2 or a mixed gas of CO, H2 and N2.

[0028] Furthermore, in step (3), the reduction sintering temperature is 800-1600° C., and the reduction sintering time is 7-20 h.

[0029] Furthermore, in step (3), the grinding time for performing sufficient grinding again (secondary grinding) is 5 to 120 minutes.

[0030] In some embodiments of the present invention, the reduction sintering temperature in step (3) is 1100-1600° C., and the sintering time is 8-15 hours.

[0031] In some embodiments of the present invention, during the reduction sintering in step (3), the reducing atmosphere is a hydrogen-nitrogen mixed atmosphere of 5% H2-95% N2.

[0032] In one embodiment of the present invention, in step (3), the reduction sintering is high-temperature sintering, and the method of high-temperature sintering is: placing the precursor obtained in step (2) in a crucible, and placing the crucible in a vacuum tube furnace, evacuating the crucible, and sintering at 1000-1600°C for 0.5-15h, maintaining a reducing atmosphere during sintering, to obtain the green fluorescent material excited by purple light.

[0033] In one embodiment of the present invention, in step (2), during high temperature sintering, the system pressure is maintained at 1 standard atmosphere.

[0034] The green fluorescent material excited by violet light obtained by the preparation method of the present invention is a powdery material.

[0035] The present invention further provides an application of the green fluorescent material excited by violet light. The green fluorescent material excited by violet light can be mixed with red and blue multicolor fluorescent powders to prepare a white light LED light source.

[0036] The present invention further provides an LED light source, which contains the green fluorescent material excited by the violet light. The LED light source can be applied to healthy lighting fields such as violet light-excited white light LED, violet light-excited sunlight-like LED, and violet light-excited full-spectrum LED, and has great development potential.

[0037] Compared with the prior art, the present invention provides a new, unreported, green fluorescent material excited by violet light and its preparation method and application, which is a wide-excitation green fluorescent powder. The innovation of the present invention is:

[0038] (1) The phosphor of the present invention has a wide excitation band and can effectively absorb excitation light in the range of 270 to 480 nm. It can be excited by ultraviolet light, purple light, and blue light to achieve bright and dazzling green light emission. The emission center is at 528 nm, which has not been reported before.

[0039] (2) Compared with the prior art, the phosphor of the present invention is a broad excitation green phosphor with the advantage of stable physical and chemical properties. At the same time, the preparation process of the present invention is simple and does not require high temperature and high pressure, which is conducive to industrial production.

[0040] (3) The phosphor of the present invention has an emission wavelength of 440 to 700 nm and can effectively absorb light in the wavelength range of 270 to 480 nm. It can be well matched with existing ultraviolet light chips and has excellent luminous performance, meeting the needs of the commercial market. It has great development potential in the field of healthy lighting such as ultraviolet-excited white light LEDs, ultraviolet-excited solar-like LEDs, and ultraviolet-excited full-spectrum LEDs. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a photoexcitation-emission spectrum diagram of the green phosphor excited by violet light of Examples 1-3 of the present invention.

[0042] Figure 2 It is the XRD diffraction pattern of the green phosphor excited by violet light prepared in Example 1-3 of the present invention. DETAILED DESCRIPTION

[0043] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0044] Features such as component models, material names, connection structures, control methods, algorithms, etc. that are not clearly stated in this technical solution shall be deemed as common technical features disclosed in the prior art.

[0045] Embodiment 1:

[0046] This embodiment provides a green light phosphor excited by violet light, the chemical formula of which is CaSrLu 3.495 La 0.5 O8:0.005Ce 3+ , the preparation method comprises the following steps:

[0047] 1. Select CaCO3, SrCO3, Lu2O3, La2O3, and CeO2 as starting materials, Ca∶Sr∶Lu∶La∶Ce=1∶1∶3.495∶0.5∶0.005 (molar ratio), corresponding to x=0.005, weigh five raw materials respectively, and control the total mass of the raw material mixture to be 10g of mixed raw material.

[0048] 2. The raw material mixture is placed in an agate mortar and ground for 20 to 50 minutes. After the materials are evenly mixed, the mixture is loaded into an alumina crucible. The alumina crucible containing the raw materials is first placed in an air atmosphere and calcined at 500°C for 5 hours, and then naturally cooled to room temperature; the obtained mixed product is then fully ground again. After grinding evenly, it is placed in a reducing atmosphere of hydrogen and nitrogen mixture and calcined at 1100°C for 0.5 hours, and then cooled to room temperature to obtain the target product CaSrLu 3.495 La 0.5 O8: 0.005Ce 3+ .

[0049] 3. Use fluorescence spectrometer (HITACHI F-7000) to test the spectral properties of the phosphor in the system, such as Figure 1 As shown. The results show that the phosphor of this system has a wide excitation band, covering the ultraviolet and purple regions, with a peak at 420nm, indicating that it can be effectively excited by ultraviolet and purple chips and matches well with a variety of commercial chips. Under the excitation of a 420nm purple light source, the phosphor emits bright green light, and the emission spectrum consists of a wide emission band (440-700nm) with a peak at 528nm.

[0050] Embodiment 2:

[0051] This embodiment provides a green light phosphor excited by violet light, the chemical formula of which is CaSrLu 3.49 La 0.5 O8:0.01Ce 3+ , the preparation method comprises the following steps:

[0052] 1. Select CaCO3, SrCO3, Lu2O3, La2O3, and CeO2 as starting materials, Ca∶Sr∶Lu∶La∶Ce=1∶1∶3.49∶0.5∶0.01 (molar ratio), corresponding to x=0.01, weigh five raw materials respectively, and control the total mass of the raw material mixture to be 10g of mixed raw material.

[0053] 2. The raw material mixture is placed in an agate mortar and ground for 20 to 50 minutes. After the materials are evenly mixed, the mixture is loaded into an alumina crucible. The alumina crucible containing the raw materials is first placed in an air atmosphere and calcined at 550°C for 6 hours, and then naturally cooled to room temperature; the obtained mixed product is then fully ground again. After grinding evenly, it is placed in a hydrogen and nitrogen mixed reducing atmosphere and calcined at 1150°C for 3.5 hours, and then cooled to room temperature to obtain the target product CaSrLu 3.49 La 0.5 O8:0.01Ce 3+ .

[0054] 3. Use fluorescence spectrometer (HITACHI F-7000) to test the spectral properties of the phosphor in the system, such as Figure 1 As shown. The results show that the phosphor of this system has a wide excitation band, covering the ultraviolet and purple regions, with a peak at 420nm and a high spectral peak, indicating that it can be effectively excited by ultraviolet and purple chips and matches well with a variety of commercial chips. Under the excitation of a 420nm purple light source, the phosphor emits bright green light, and the emission spectrum consists of a wide emission band (440-700nm) with a peak at 528nm.

[0055] Embodiment 3:

[0056] This embodiment provides a green light phosphor excited by violet light, the chemical formula of which is CaSrLu 3.48 La 0.5 O8: 0.02Ce 3+ , the preparation method comprises the following steps:

[0057] 1. Select CaCO3, SrCO3, Lu2O3, La2O3, and CeO2 as starting materials, Ca∶Sr∶Lu∶La∶Ce=1∶1∶3.48∶0.5∶0.02 (molar ratio), corresponding to x=0.02, weigh the five raw materials separately, and control the total mass of the raw material mixture to be 10g of mixed raw material.

[0058] 2. The raw material mixture is placed in an agate mortar and ground for 20 to 50 minutes. After the materials are evenly mixed, the mixture is loaded into an alumina crucible. The alumina crucible containing the raw materials is first placed in an air atmosphere and calcined at 600°C for 7 hours, and then naturally cooled to room temperature; the obtained mixed product is then fully ground again, and then placed in a hydrogen and nitrogen mixed reducing atmosphere for calcination at 1200°C for 7 hours, and then cooled to room temperature to obtain the target product CaSrLu 3.48 La 0.5 O8: 0.02Ce 3+ .

[0059] 3. Use fluorescence spectrometer (HITACHI F-7000) to test the spectral properties of the phosphor in the system, such as Figure 1 As shown. The results show that the phosphor of this system has a wide excitation band, covering the ultraviolet and purple regions, with a peak at 420nm and a high spectral peak, indicating that it can be effectively excited by ultraviolet and purple chips and matches well with a variety of commercial chips. Under the excitation of a 420nm purple light source, the phosphor emits bright green light, and the emission spectrum consists of a wide emission band (440-700nm) with a peak at 528nm.

[0060] Embodiment 4:

[0061] This embodiment provides a green light phosphor excited by violet light, the chemical formula of which is CaSrLu 3.47 La 0.5 O8: 0.03Ce 3+ , the preparation method comprises the following steps:

[0062] 1. Select CaCO3, SrCO3, Lu2O3, La2O3, and CeO2 as starting raw materials, Ca∶Sr∶Lu∶La∶Ce=1∶1∶3.47∶1∶0.03 (molar ratio), corresponding to x=0.03, weigh five raw materials respectively, and control the total mass of the raw material mixture to be 10g of mixed raw material.

[0063] 2. The raw material mixture was placed in an agate mortar and ground for 20 to 50 mm. After the materials were evenly mixed, the mixture was loaded into an alumina crucible. The alumina crucible containing the raw materials was first placed in an air atmosphere and calcined at 650 ° C for 8 hours, and then naturally cooled to room temperature; the obtained mixed product was then fully ground again, and then placed in a hydrogen and nitrogen mixed reducing atmosphere for calcination at 1250 ° C for 10 hours, and then cooled to room temperature to obtain the target product CaSrLu 3.47 La 0.5 O8: 0.03Ce 3+ The fluorescence spectrum properties of the green fluorescent material are similar to those in Example 1.

[0064] Embodiment 5:

[0065] This embodiment provides a green light phosphor excited by violet light, the chemical formula of which is CaSrLu 3.4 6La 0.5 O8: 0.04Ce 3+ , the preparation method comprises the following steps:

[0066] 1. Select CaCO3, SrCO3, Lu2O3, La2O3, and CeO2 as starting materials, Ca∶Sr∶Lu∶La∶Ce=1∶1∶3.46∶1∶0.04 (molar ratio), corresponding to x=0.04, weigh the five raw materials separately, and control the total mass of the raw material mixture to be 10g of mixed raw material.

[0067] 2. The raw material mixture was placed in an agate mortar and ground for 20 to 50 minutes. After the materials were evenly mixed, the mixture was loaded into an alumina crucible. The alumina crucible containing the raw materials was first placed in an air atmosphere and calcined at 700°C for 9 hours, and then naturally cooled to room temperature; the obtained mixed product was then fully ground again and placed in a hydrogen-nitrogen mixed reducing atmosphere for calcination at 1300°C for 11 hours, and then cooled to room temperature to obtain the target product CaSrLu 3.46 La 0.5 O8: 0.04Ce 3+ The fluorescence spectrum properties of the green fluorescent material are similar to those in Example 1.

[0068] Embodiment 6:

[0069] This embodiment provides a green light phosphor excited by violet light, the chemical formula of which is CaSrLu 3.45 La 0.5 O8: 0.05Ce 3+ , the preparation method comprises the following steps:

[0070] 1. Select CaCO3, SrCO3, Lu2O3, La2O3, and CeO2 as starting materials, Ca∶Sr∶Lu∶La∶Ce=1∶1∶3.45∶0.5∶0.05 (molar ratio), corresponding to x=0.05, weigh the five raw materials separately, and control the total mass of the raw material mixture to be 10g of mixed raw material.

[0071] 2. The raw material mixture is placed in an agate mortar and ground for 20 to 50 minutes. After the materials are evenly mixed, the mixture is loaded into an alumina crucible. The alumina crucible containing the raw materials is first placed in an air atmosphere and calcined at 750°C for 10 hours, and then naturally cooled to room temperature; the obtained mixed product is then fully ground again, and then placed in a hydrogen and nitrogen mixed reducing atmosphere for calcination at 1350°C for 12 hours, and then cooled to room temperature to obtain the target product CaSrLu 3.45 La 0.5 O8: 0.05Ce 3+ The fluorescence spectrum properties of the green fluorescent material are similar to those in Example 1.

[0072] Embodiment 7:

[0073] This embodiment provides a green light phosphor excited by violet light, the chemical formula of which is CaSrLu 3.44 La 0.5 O8: 0.06Ce 3+ , the preparation method comprises the following steps:

[0074] 1. Select CaCO3, SrCO3, Lu2O3, La2O3, and CeO2 as starting materials, Ca∶Sr∶Lu∶La∶Ce=1∶1∶3.44∶0.5∶0.06 (molar ratio), corresponding to x=0.06, weigh the five raw materials separately, and control the total mass of the raw material mixture to be 10g of mixed raw material.

[0075] 2. The raw material mixture is placed in an agate mortar and ground for 20 to 50 minutes. After the materials are evenly mixed, the mixture is loaded into an alumina crucible. The alumina crucible containing the raw materials is first placed in an air atmosphere and calcined at 800°C for 11 hours, and then naturally cooled to room temperature; the obtained mixed product is then fully ground again, and then placed in a hydrogen and nitrogen mixed reducing atmosphere for calcination at 1500°C for 13 hours, and then cooled to room temperature to obtain the target product CaSrLu 3.44 La 0.5 O8: 0.06Ce 3+ The fluorescence spectrum properties of the green fluorescent material are similar to those in Example 1.

[0076] Embodiment 8:

[0077] This embodiment provides a green light phosphor excited by violet light, the chemical formula of which is CaSrLu 3.43 La 0.5 O8: 0.07Ce 3+ , the preparation method comprises the following steps:

[0078] 1. Select CaCO3, SrCO3, Lu2O3, La2O3, and CeO2 as starting materials, Ca∶Sr∶Lu∶La∶Ce=1∶1∶3.43∶0.5∶0.07 (molar ratio), corresponding to x=0.07, weigh five raw materials respectively, and control the total mass of the raw material mixture to be 10g of mixed raw material.

[0079] 2. The raw material mixture is placed in an agate mortar and ground for 20 to 50 minutes. After the materials are evenly mixed, the mixture is loaded into an alumina crucible. The alumina crucible containing the raw materials is first placed in an air atmosphere and calcined at 850°C for 12 hours, and then naturally cooled to room temperature; the obtained mixed product is then fully ground again, and then placed in a hydrogen and nitrogen mixed reducing atmosphere for calcination at 1600°C for 15 hours, and then cooled to room temperature to obtain the target product CaSrLu 3.43 La 0.5O8: 0.07Ce 3+ The fluorescence spectrum properties of the green fluorescent material are similar to those in Example 1.

[0080] like Figure 2 Shown is the XRD diffraction pattern of the violet light excited green phosphor prepared in Examples 1-3 of the present invention.

[0081] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A green fluorescent material excited by violet light, characterized in that: The chemical formula of this fluorescent material is CaSrLu 3.5- x La 0.5 O8:xCe 3+ , where 0.001≤x≤0.

1.

2. The green fluorescent material excited by violet light according to claim 1, characterized in that: x=0.005, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06 or 0.

07.

3. The green fluorescent material excited by violet light according to claim 1, characterized in that: The excitation spectrum of the green fluorescent material excited by violet light covers a range of 270 to 480 nm, and the emission spectrum covers a range of 440 to 700 nm; The optimal excitation position of the green fluorescent material excited by violet light is located at the violet light position of 420nm; The green fluorescent material excited by the violet light emits green light at 528 nm.

4. A method for preparing a green fluorescent material excited by violet light as claimed in any one of claims 1 to 3, characterized in that: The following steps are involved: (1) weighing a calcium source compound raw material powder, a strontium source compound raw material powder, a lutetium source compound raw material powder, a lanthanum source compound raw material powder, and a cerium source compound raw material powder according to a stoichiometric ratio of a chemical formula, mixing and grinding the raw material powders so that the raw material powders are uniformly mixed to obtain a ground raw material; (2) calcining the ground raw material obtained in step (1) and then cooling it to obtain a precursor; (3) Grinding the precursor obtained in step (2) for a second time to mix evenly, reducing and sintering, and cooling to obtain the purple light excited green fluorescent material.

5. The method for preparing a green fluorescent material excited by violet light according to claim 4, characterized in that: In step (1), the calcium source compound is CaCO3, the strontium source compound is SrCO3, the lutetium source compound is Lu2O3, the lanthanum source compound is La2O3, and the cerium source compound is CeO2.

6. The method for preparing a green fluorescent material excited by violet light according to claim 4, characterized in that: In step (1), the grinding time of the raw material powder is 5 to 120 minutes.

7. The method for preparing a green fluorescent material excited by violet light according to claim 4, characterized in that: The calcination in step (2) is calcination in an air atmosphere; The calcination temperature in step (2) is 200-1000° C., and the calcination time is 5-24 hours.

8. The method for preparing a green fluorescent material excited by violet light according to claim 4, characterized in that: In step (3), during reduction sintering, the reducing atmosphere is selected from CO gas or a mixed gas of H2 and N2 or a mixed gas of CO, H2 and N2; The reduction sintering temperature in step (3) is 800-1600° C., and the reduction sintering time is 7-20 hours.

9. An application of the green fluorescent material excited by violet light as claimed in any one of claims 1 to 3, characterized in that: The green fluorescent material excited by violet light is used to prepare an LED light source.

10. An LED light source, characterized in that: The LED light source comprises the green fluorescent material excited by violet light as described in any one of claims 1-3.

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