Blue-green fluorescent powder as well as preparation method and application thereof

Abstract

The invention relates to the technical field of preparation of blue-green fluorescent powder, in particular to blue-green fluorescent powder as well as a preparation method and application thereof. The general chemical formula of the blue-green fluorescent powder is (Lu2-a-bR1 + aCeb) (L4-xMx) SiO12, wherein R is at least one of Ca < 2 + > and Sr < 2 + >; l is at least one of Al < 3 + >, Ga < 3 + > and In < 3 + >; m is at least one of Sb < 3 + >, Ga < 3 + > and In < 3 + >; a, b and x are all stoichiometric numbers of elements, a is greater than or equal to 0.01 b and less than or equal to 0.5 b, b is greater than or equal to 0.0001 and less than or equal to 0.3, and x is greater than or equal to 0.01 and less than or The fluorescent powder has the advantages that the fluorescent powder is simple in preparation method and free of pollution, has the characteristics of high efficiency, broadband blue-green emission and the like, and has relatively high efficiency when being applied to a white-light illumination LED (Light Emitting Diode); the blue-green fluorescent powder can be mixed with commercial red fluorescent powder for use, and a white light source with adjustable color temperature and high color rendering can be packaged.

Description

Technical Field

[0001] The present invention relates to the technical field of the preparation of blue-green phosphors, and particularly relates to a blue-green phosphor, a preparation method thereof, and an application thereof. Background Art

[0002] Phosphor-converted white light-emitting diode technology is widely used in our lives due to its many advantages such as high efficiency, environmental protection, low energy consumption, and long service life. However, traditional white LEDs based on blue chips and Y 3 Al 5 O 12 : Ce 3+ (YAG: Ce 3+ ) have a low color rendering index due to the lack of cyan components, and a series of problems such as spectral missing and blue light hazards are caused by the cyan depression. At the same time, the existing cyan phosphor BaSi 2 O 2 N 2 : Eu 2+ As a kind of oxynitride, its preparation method is more complex than that of oxides, and its structure is not stable enough. Based on this, developing new oxide blue-green phosphors to achieve full-spectrum lighting has become a new trend in the development of "healthy green lighting". Full-spectrum lighting has many advantages such as good spectral continuity, being similar to the solar spectrum, no obvious peaks and valleys in the spectral distribution, and a high color rendering index. Full-spectrum LEDs have wide applications in the fields of operating rooms, museums, plant supplementary lighting, photographic stage lighting, and health lighting.

[0003] There are various ways to achieve full-spectrum LEDs, mainly using a multi-LED chip structure or a single-chip LED coated with phosphors. The former has a complex control circuit, high manufacturing cost, and different performances and light decays between different chips, resulting in unstable white light color temperature and poor application performance. The latter mostly uses near-ultraviolet chips or blue chips coated with three or more different emission-band phosphors to achieve the purpose of full spectrum. Existing luminescent materials generally have the problem of low luminous efficiency, and problems such as color drift caused by reabsorption between different phosphors and inconsistent light decay of phosphors seriously hinder the development of full-spectrum lighting LEDs and limit their application in the market. Therefore, in practical applications, developing a highly efficient full-spectrum lighting source that uses two phosphors for encapsulation, can achieve different color temperatures while having a high color rendering index, and has a simple structure is of great significance and market prospects. Summary of the Invention

[0004] In order to solve the above problems, the present invention provides a blue-green phosphor, a preparation method thereof, and an application thereof.

[0005] The first object of the present invention is to provide a blue-green phosphor, the blue-green phosphor having a garnet structure and a chemical general formula of: (Lu 2-a-b R 1+a Ce b )(L 4-x M x )SiO 12 ; wherein, R is at least one of Ca 2+ , Sr 2+ ; L is at least one of Al 3+ , Ga 3+ , In 3+ ; M is at least one of Sb 3+ , Ga 3+ , In 3+ ; a, b, and x are all stoichiometric numbers of elements, 0.01b ≤ a ≤ 0.5b, 0.0001 ≤ b ≤ 0.3, 0.01 ≤ x ≤ 3.99.

[0006] Preferably, R is Sr 2+ , L is Al 3+ , and M is Ga 3+ .

[0007] Preferably, x = 1.5.

[0008] Preferably, x = 2.

[0009] Preferably, x = 2.5.

[0010] Preferably, x = 3.

[0011] Preferably, a = 0.01; b = 0.17.

[0012] The second object of the present invention is to provide a method for preparing a blue-green phosphor, specifically including the following steps: S1. According to the stoichiometric ratio of each element in the chemical general formula (Lu 2-a-b R 1+a Ce b )(L 4-x M x )SiO 12 , weigh Lu 2 O 3 , SrCO 3 , Ga 2 O 3 , Al 2 O 3 , SiO 2 , and CeO 2 , and grind and mix them evenly; S2. Place the mixture under a reducing atmosphere and calcine it at 1250 - 1450 °C for 8 - 14 h to obtain a sintered body; the reducing atmosphere is a nitrogen-hydrogen mixture with a hydrogen content of 10%. S3. Cool and discharge the material. Then, grind the mixture sufficiently and mix it evenly. Place it under a reducing atmosphere and calcine it at 1220 - 1420 °C for 4 - 7 h to obtain a sintered body. S4. Cool the sintered body, and then crush, wash, filter, and dry it to obtain the blue-green phosphor.

[0013] The third object of the present invention is to provide an application of the blue-green phosphor in the preparation of white light LED lighting sources.

[0014] Preferably, the preparation method of the white light LED lighting source specifically includes the following steps: Weigh the blue-green phosphor, red phosphor, and glue, and mix them to obtain a phosphor-containing slurry; uniformly coat the mixed slurry on the LED chip or on the housing with an embedded LED chip, and cure it to obtain the white light LED lighting source. The mass of the blue-green phosphor accounts for 20 - 98% of the total mass of the mixture of the blue-green phosphor and the red phosphor. The wavelength band of the red phosphor is the red light band of 630 - 650 nm. The material of the glue is epoxy resin or silica gel, which is divided into A and B components. Mix the A and B components to obtain the glue for encapsulation.

[0015] Compared with the prior art, the present invention can achieve the following beneficial effects: The preparation method of the blue-green phosphor of the present invention is simple, pollution-free, and has stable chemical properties. It has characteristics such as high efficiency and broadband blue-green emission, and has high efficiency when applied to the preparation of white light LED light sources. At the same time, the present invention can, according to different application scenarios, only by mixing two phosphors, achieve high color rendering index white light sources at different color temperatures, and can effectively fill the blue-green gap in the spectrum, providing a very valuable broadband emission blue-green phosphor luminescent material. Description of the Drawings

[0016] Figure 1 is the XRD diffraction pattern of the blue-green phosphor provided in Example 1 of the present invention.

[0017] Figure 2 is the excitation spectrum and emission spectrum of the blue-green phosphor provided in Example 1 of the present invention.

[0018] Figure 3 is the excitation spectrum and emission spectrum of the blue-green phosphor provided in Examples 1 - 6 of the present invention; in the figure, A is the excitation spectrum and B is the emission spectrum.

[0019] Figure 4 is the X-ray diffraction pattern of the blue-green phosphor provided in Embodiments 1, 4, and 6 of the present invention.

[0020] Figure 5 is a comparison chart of the emission spectral intensities of the blue-green phosphors provided in Embodiment 4 and Embodiments 7-11 of the present invention.

[0021] Figure 6 is the electroluminescence spectrum diagram of the white LED lighting source provided in the embodiments of the present invention. Detailed Embodiments

[0022] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the same modules are denoted by the same reference numerals. In the case of the same reference numerals, their names and functions are also the same. Therefore, their detailed descriptions will not be repeated.

[0023] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation to the present invention.

[0024] The present invention provides a blue-green phosphor, which has a garnet structure and a chemical general formula of: (Lu 2-a-b R 1+a Ce b )(L 4-x M x )SiO 12 ; wherein, R is at least one of Ca 2+ , Sr 2+ ; L is at least one of Al 3+ , Ga 3+ , In 3+ ; M is at least one of Sb 3+ , Ga 3+ , In 3+ ; a, b, and x are all stoichiometric numbers of elements, 0.01b ≤ a ≤ 0.5b, 0.0001 ≤ b ≤ 0.3, 0.01 ≤ x ≤ 3.99.

[0025] In a specific embodiment, R is Sr 2+ , L is Al 3+ , and M is Ga 3+ .

[0026] In a specific embodiment, a is 0.01 or 0.001; b is 0.01, 0.09, 0.13, 0.17, 0.21 or 0.25; x is 0.5, 1, 1.5, 2, 2.5 or 3.

[0027] The preparation method of the above blue-green phosphor is characterized in that it specifically comprises the following steps: S1. According to the stoichiometric ratios of the respective elements in the chemical general formula (Lu 2-a-b R 1+a Ce b )(L 4-x M x )SiO 12 , weigh out Lu 2 O 3 , SrCO 3 , Ga 2 O 3 , Al 2 O 3 , SiO 2 and CeO 2 , and grind and mix them thoroughly and evenly; S2. Place the mixture in a reducing atmosphere and calcine it at 1250-1450 °C for 8-14 h; the reducing atmosphere is a nitrogen-hydrogen mixture with a hydrogen content of 10%; S3. Cool and discharge the material, grind and mix the mixture thoroughly and evenly again, place it in a reducing atmosphere, and calcine it at 1220-1420 °C for 4-7 h to obtain a sintered body; S4. Cool the sintered body, and crush, wash, filter and dry it to obtain the blue-green phosphor.

[0028] Specifically, a mortar, a ball mill or other grinding equipment is used for grinding; Specifically, the calcination temperature in step S2 is 1430 °C and the calcination time is 10 h; the calcination temperature in step S3 is 1400 °C and the calcination time is 3 h; Specifically, the drying method is drying by baking.

[0029] The present invention also provides a preparation method of a white LED lighting source, which specifically comprises the following steps: weigh out the blue-green phosphor, the red phosphor and the glue, mix them to obtain a phosphor-containing slurry; uniformly coat the mixed slurry on the LED chip or on the housing with the built-in LED chip, and cure it to obtain the white LED lighting source.

[0030] Specifically, the LED chip is a blue LED chip; the emission range of the blue LED chip is 420-460 nm; Specifically, the material of the glue is epoxy resin or silica gel, which is divided into A and B glues, and the A and B glues are mixed and used as the glue for encapsulation; Specifically, the curing method is room temperature curing, high temperature curing or light curing; Specifically, the wavelength of the red phosphor is the red light band of 630-650 nm; Specifically, the mass of the blue-green phosphor accounts for 20-98% of the total mass of the phosphor (the mass of the mixture of the blue-green phosphor and the red phosphor), preferably 60-98%; it can be adjusted according to application requirements. By adjusting the ratio of the blue-green phosphor to the red phosphor, a high color rendering index white light source with different color temperatures can be achieved.

[0031] The present invention uses divalent R ions with an additional component of a to compensate for the remaining tetravalent Ce ions in the material, which is beneficial to suppressing the generation of defects in the material and obtaining efficient luminescence. The prepared blue-green phosphor can be mixed with commercial red phosphor to encapsulate a white light LED with adjustable color temperature and high color rendering, which has a broad application market.

[0032] Using Lu 2 O 3 、SrCO 3 , Ga 2 O 3 、Al 2 O 3 、SiO 2 and CeO 2 The cyan luminescent material of each embodiment of the present invention is prepared as a raw material. This material is used to solve the problem of "blue-green depression" in white light LEDs and only two phosphors are needed to realize a high color rendering index white light LED without obvious spectral loss. The principle is that this material has a small Stokes shift and a wide blue light excitation band. At the same time, not all cyan phosphors and cyan phosphors similar to or derived from this component can realize the combination of two phosphors to realize the preparation of white light LEDs with high color rendering index and tunable color temperature, such as the traditional cyan phosphor BaSi 2 O 2 N 2 : Eu 2+ Green phosphor and red phosphor need to be coated on the blue LED to realize the preparation of white LED. Based on the above discussion, the present invention provides the following embodiments.

[0033] Example 1 This embodiment provides a method for preparing a blue-green phosphor, which specifically includes the following steps: S1. According to the chemical formula Lu 1.989 Sr 1.001 Ce 0.01 Al 3.5 Ga 0.5 SiO 12For the stoichiometric ratios of the various elements in, weigh out Lu 2 O 3 、SrCO 3 、Ga 2 O 3 、Al 2 O 3 、SiO 2 and CeO 2 , grind thoroughly and mix evenly; S2. Place the mixture in a high-purity alumina crucible, introduce a nitrogen-hydrogen mixture with a hydrogen content of 10%, and calcine at 1430 °C (holding temperature) for 10 h; S3. Cool, discharge, then grind thoroughly and mix evenly again, introduce a nitrogen-hydrogen mixture with a hydrogen content of 10%, and calcine at 1400 °C (holding temperature) for 3 h; S4. Cool and discharge again, grind, and then wash, filter, and dry to obtain a blue-green phosphor for lighting with blue-green band emission characteristics.

[0034] Perform XRD analysis on the blue-green phosphor obtained in Example 1. The XRD diffraction pattern is as shown in Figure 1 ; It can be seen from the curve in Figure 1 that the phosphor prepared in Example 1 and the X-ray diffraction spectrum (XRD) of the Lu 3 Al 5 O 12 standard card comparison shows that this phosphor is a garnet structure.

[0035] Analyze the excitation spectrum and emission spectrum of the blue-green phosphor obtained in Example 1. The results are as shown in Figure 2 . The figure shows the 5d- 3+ of Ce in the phosphor, 2 F 5 / 2 , 5d- 2 F 7 / 2 emission spectrum (broadband emission), the excitation wavelength is 447 nm; the emission wavelength is 502 nm; It can be seen from Figure 2 that this phosphor contains two effective excitation bands, namely 324~380 nm and 380~491 nm respectively, and can be excited by a 420~460 nm LED chip. The emission peak of this phosphor is located near 500 nm, showing broadband emission.

[0036] Example 2 This example provides a method for preparing a blue-green phosphor. Among them, in step S1, according to the chemical formula Lu 1.989 Sr 1.001 Ce 0.01 Al 3 GaSiO 12The stoichiometric ratios of the various elements in, weigh out Lu 2 O 3 、SrCO 3 、Ga 2 O 3 、Al 2 O 3 、SiO 2 and CeO 2 ; The preparation process is the same as that in Example 1.

[0037] Example 3 This example provides a method for preparing a blue-green phosphor. Among them, in step S1, according to the chemical formula Lu 1.989 Sr 1.001 Ce 0.01 Al 2.5 Ga 1.5 SiO 12 The stoichiometric ratios of the various elements in, weigh out Lu 2 O 3 、SrCO 3 、Ga 2 O 3 、Al 2 O 3 、SiO 2 and CeO 2 ; The preparation process is the same as that in Example 1.

[0038] Example 4 This example provides a method for preparing a blue-green phosphor. Among them, in step S1, according to the chemical formula Lu 1.989 Sr 1.001 Ce 0.01 Al 2 Ga 2 SiO 12 The stoichiometric ratios of the various elements in, weigh out Lu 2 O 3 、SrCO 3 、Ga 2 O 3 、Al 2 O 3 、SiO 2 and CeO 2 ; The preparation process is the same as that in Example 1.

[0039] Example 5 This example provides a method for preparing a blue-green phosphor. Among them, in step S1, according to the chemical formula Lu 1.989 Sr 1.001 Ce 0.01 Al 1.5 Ga 2.5 SiO 12The stoichiometric ratios of the elements in 2 O 3 、SrCO 3 、Ga 2 O 3 、Al 2 O 3 、SiO 2 and CeO 2 ; The preparation process is the same as that in Example 1.

[0040] Example 6 This example provides a method for preparing a blue-green phosphor. Among them, in step S1, according to the chemical formula Lu 1.989 Sr 1.001 Ce 0.01 AlGa 3 SiO 12 The stoichiometric ratios of the elements in, weigh out Lu 2 O 3 、SrCO 3 、Ga 2 O 3 、Al 2 O 3 、SiO 2 and CeO 2 ; The preparation process is the same as that in Example 1.

[0041] The general chemical formula of the phosphors in Examples 1 to 6 is: Lu 2-a-b R 1+a Ce b L 4-x M x SiO 12 ; The raw material composition of the phosphor: Lu 2 O 3 、RCO 3 、CeO 2 、L 2 O 3 、M 2 O 3 and SiO 2 , and the molar ratio is (2 - a - b): (1 + a): b: (4 - x): x: 1, R = Sr, L = Al, M = Ga; Their raw material components and ratios, excitation wavelength, and emission wavelength are different. For details, see Table 1.

[0042] Table 1 Comparison of phosphor raw material ratios, excitation wavelengths, and emission wavelengths

[0043] The excitation spectra and emission spectra of the phosphors in Examples 1 to 6 shift as Figure 3As shown. At the same time, the XRD diffraction patterns of the phosphors prepared in Examples 1, 4, and 6 are as Figure 4 shown, indicating that a pure garnet crystal phase is synthesized without generating impurity phases, and the diffraction peaks shifting towards the small-angle direction indicates that an effective cation substitution process has been achieved.

[0044] Example 7 This example provides a method for preparing a blue-green phosphor. Among them, in step S1, according to the stoichiometric ratios of the various elements in the chemical formula Lu 1.9 Sr 1.01 Ce 0.09 Al 2 Ga 2 SiO 12 weigh out Lu 2 O 3 、SrCO 3 、Ga 2 O 3 、Al 2 O 3 、SiO 2 and CeO 2 ; The preparation process is the same as that in Example 4.

[0045] Example 8 This example provides a method for preparing a blue-green phosphor. Among them, in step S1, according to the stoichiometric ratios of the various elements in the chemical formula Lu 1.86 Sr 1.01 Ce 0.13 Al 2 Ga 2 SiO 12 weigh out Lu 2 O 3 、SrCO 3 、Ga 2 O 3 、Al 2 O 3 、SiO 2 and CeO 2 ; The preparation process is the same as that in Example 4.

[0046] Example 9 This example provides a method for preparing a blue-green phosphor. Among them, in step S1, according to the stoichiometric ratios of the various elements in the chemical formula Lu 1.82 Sr 1.01 Ce 0.17 Al 2 Ga 2 SiO 12 weigh out Lu 2 O 3 、SrCO 3 、Ga 2O 3 、Al 2 O 3 、SiO 2 and CeO 2 ; The preparation process is the same as Example 4.

[0047] Example 10 This embodiment provides a method for preparing a blue-green phosphor, wherein in step S1, according to the chemical formula Lu 1.78 Sr 1.01 Ce 0.21 Al 2 Ga 2 SiO 12 The stoichiometric ratio of each element in Lu 2 O 3 、SrCO 3 , Ga 2 O 3 、Al 2 O 3 、SiO 2 and CeO 2 ; The preparation process is the same as Example 4.

[0048] Embodiment 11 This embodiment provides a method for preparing a blue-green phosphor, wherein in step S1, according to the chemical formula Lu 1.74 Sr 1.01 Ce 0.25 Al 2 Ga 2 SiO 12 The stoichiometric ratio of each element in Lu 2 O 3 、SrCO 3 , Ga 2 O 3 、Al 2 O 3 、SiO 2 and CeO 2 ; The preparation process is the same as Example 4.

[0049] The general chemical formula of the phosphor in Examples 7 to 11 is: Lu 2-a-b R 1+a Ce b L 4-x M x SiO 12 ; Phosphor raw material composition: Lu 2 O 3 , RCO 3 、CeO 2 , L 2 O 3 、M2 O 3 and SiO 2 with a molar ratio of (2 - a - b):(1 + a):b:(4 - x):x:1, where R = Sr, L = Al, M = Ga; compared with Comparative Example 4, their raw material components and ratios, emission wavelengths, and emission intensities are different. For details, see Table 2. It can be seen from the table that the emission intensity of the blue - green phosphor prepared in Example 9 is the largest.

[0050] Table 2 Comparison of phosphor raw material ratios, emission wavelengths, and emission intensities

[0051] Comparison of the emission spectral intensities of the blue - green phosphors in Example 4 and Examples 7 - 11 is as Figure 5 shown.

[0052] Example 12 This example provides a preparation method for a white - light LED lighting source, which specifically includes the following steps: Weigh the blue - green phosphor in Example 9, a commercial red phosphor with a wavelength of 630 nm (with a mass ratio of the two of 40:1), and glue, and mix them to obtain a phosphor - containing slurry (the mass fraction of the phosphor is 67%); uniformly coat the mixed slurry on a 440 - nm blue - light LED chip, and after curing, obtain a white - light source with a color temperature of 3500 K and a high color rendering index (Ra = 93.6). This white - light source has excellent luminous efficiency, and its lumen efficiency is 117.5 lm / W.

[0053] Example 13 This example provides a preparation method for a white - light LED lighting source, which specifically includes the following steps: Weigh the blue - green phosphor in Example 9, a commercial red phosphor with a wavelength of 630 nm (with a mass ratio of the two of 45:1), and glue, and mix them to obtain a phosphor - containing slurry (the mass fraction of the phosphor is 62%); uniformly coat the mixed slurry on a 440 - nm blue - light LED chip, and after curing, obtain a white - light source with a color temperature of 4035 K and a high color rendering index (Ra = 95.6). This white - light source has excellent luminous efficiency, and its lumen efficiency is 127.3 lm / W.

[0054] Example 14 This embodiment provides a method for preparing a white light LED illumination source, which specifically includes the following steps: Weigh the blue-green phosphor in Example 9, the commercial red phosphor with a wavelength of 645 nm (with a mass ratio of 80:1 between the two), and glue, and after mixing, obtain a phosphor-containing slurry (the mass fraction of the phosphor is 40%); uniformly coat the mixed slurry on a 450-nm blue LED chip, and after curing, obtain a white light source with a color temperature of 4712 K and a high color rendering index (Ra = 91.2). This white light source has excellent luminous efficiency, and its lumen efficiency is 113.7 lm / W.

[0055] Example 15 This embodiment provides a method for preparing a white light LED illumination source, which specifically includes the following steps: Weigh the blue-green phosphor in Example 9, the commercial red phosphor with a wavelength of 645 nm (with a mass ratio of 90:1 between the two), and glue, and after mixing, obtain a phosphor-containing slurry (the mass fraction of the phosphor is 40%); uniformly coat the mixed slurry on a 450-nm blue LED chip, and after curing, obtain a white light source with a color temperature of 6837 K and a high color rendering index (Ra = 92.0). This white light source has excellent luminous efficiency, and its lumen efficiency is 123.1 lm / W.

[0056] Figure 6 The electroluminescence spectra of the white light LED illumination sources encapsulated in Examples 12 to 15 are shown.

[0057] As can be seen from the above examples, the method for preparing the blue-green phosphor of the present invention is simple, pollution-free, and has stable chemical properties, and has high efficiency when applied to the preparation of white light illumination LED sources. At the same time, the present invention can realize high color rendering index white light sources at different color temperatures only by mixing two phosphors according to different application scenarios, and provides a very valuable broadband emission blue-green phosphor luminescent material.

[0058] It should be understood that the various forms of the processes shown above can be used, with steps reordered, added, or deleted. For example, the steps recited in the disclosure of the present invention can be executed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution disclosed in the present invention can be achieved, and this is not limited herein.

[0059] The above specific embodiments do not constitute a limitation on the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A blue-green phosphor, characterized in that: The blue-green phosphor has a garnet structure and a general chemical formula: (Lu 2-a-b R 1+a Ce b )(L 4-x M x )SiO 12 ; Where R is Ca 2+ , Sr 2+ At least one of; L is Al 3+ , Ga 3+ 、In 3+ At least one of; M is Sb 3+ , Ga 3+ 、In 3+ At least one of; a, b and x are all stoichiometric coefficients of the elements, 0.01b≤a≤0.5b, 0.0001≤b≤0.3, 0.01≤x≤3.

99.

2. The blue-green phosphor according to claim 1, characterized in that: The R is Sr 2+ , where L is Al 3+ , wherein M is Ga 3+ .

3. The blue-green phosphor according to claim 2, characterized in that: Said x=1.

5.

4. The blue-green phosphor according to claim 2, characterized in that: Said x=2.

5. The blue-green phosphor according to claim 2, characterized in that: Said x=2.

5.

6. The blue-green phosphor according to claim 2, characterized in that: Said x=3.

7. The blue-green phosphor according to claim 4, characterized in that: The a=0.01; the b=0.

17.

8. The method for preparing a blue-green phosphor according to any one of claims 1 to 7, characterized in that: The specific steps include: S1. According to the chemical formula (Lu 2-a-b R 1+a Ce b )(L 4-x M x )SiO 12 According to the stoichiometric ratio of each element, Lu2O3, SrCO3, Ga2O3, Al2O3, SiO2 and CeO2 are weighed, fully ground and mixed; S2. The mixture is placed in a reducing atmosphere and calcined at 1250~1450 ℃ for 8~14h to obtain a sintered body; the reducing atmosphere is a nitrogen-hydrogen mixture having a hydrogen content of 10%; S3. Cooling and discharging, the mixture was then fully ground and mixed, placed in a reducing atmosphere, and calcined at 1220~1420℃ for 4~7h to obtain a sintered body; S4. Cool the sintered body, and crush, wash, filter, and dry it to obtain a blue-green phosphor.

9. Use of the blue-green phosphor according to any one of claims 1 to 7 in preparing a white light LED lighting source.

10. The use of a blue-green phosphor according to claim 9 in preparing a white light LED lighting source, characterized in that: The method for preparing the white light LED lighting source specifically comprises the following steps: weighing blue-green fluorescent powder, red fluorescent powder and glue, and mixing them to obtain a slurry containing fluorescent powder; uniformly coating the mixed slurry on the LED chip or on the housing of the built-in LED chip, and curing it to obtain a white light LED lighting source; The mass of the blue-green phosphor accounts for 20-98% of the mass of the mixture of the blue-green phosphor and the red phosphor; The wavelength of the red phosphor is 630-650 nm. The glue is made of epoxy resin or silicone, and is divided into A glue and B glue. The A glue and B glue are mixed and used as glue for packaging.

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