CN106635016A - Phosphor, preparation method thereof and light-emitting device - Google Patents

Abstract

The invention belongs to the field of fluorescent powder, and in particular relates to a fluorescent powder. The chemical formula of the fluorescent powder is (A _1-a-b Gd _a Q _b ) ₃ M ₅ D ₁₂ , wherein A is one or both of Lu and La. Q is a group composed of one or more of Ce, Nd, Sm, Pr, Dy, Ho, Er or Tm; M is any one of B, Al, Ga or In D is a group consisting of any one or more of O, N, S, C1 or F; and 0.4≤a≤0.53, 0.005≤b≤0.469; The fluorescent powder is a crystalline phase crystal. The phosphor powder of the present invention has a large emission peak with a full width at half maximum, and has sufficient luminous intensity in a region longer than the wavelength of yellow light (that is, about 600nm to 690nm), so when added to a blue LED, it can emit warm white light . The fluorescent powder of the present invention has high external quantum efficiency, high internal quantum efficiency, high luminous efficiency and high absorption rate, and can be widely used in light emitting devices, display devices or lighting devices.

Description

A kind of fluorescent powder and its preparation method and light-emitting device

technical field

The invention belongs to the field of fluorescent powder, and in particular relates to a fluorescent powder composed of a complex doped with rare earth elements and a preparation method thereof, and a light-emitting device, a display device, and a lighting device using the fluorescent powder.

Background technique

White light-emitting diodes (Light-emitting diodes, LEDs) have become the next generation of lighting due to their features of energy saving, environmental protection and long life. Specific methods for obtaining white light from LEDs include: (1) combining and mixing three kinds of LEDs that emit red light, green light, and blue light respectively; (2) combining LEDs that emit ultraviolet light with those excited by ultraviolet light Combination of three fluorescent powders emitting red light, green light, and blue light fluorescence respectively, and mixing the three colors of fluorescence emitted by these fluorescent powders, and (3) combining blue LEDs that emit blue light with blue light as excitation light Phosphors emitting yellow fluorescence having a complementary color to blue light are combined, and the light of the blue LED and the yellow light emitted by the phosphor are mixed.

The method of using multiple LEDs to obtain a specific color light requires a circuit that properly adjusts the current of a single LED to achieve the purpose of balancing different colors. In contrast, the advantage of combining LEDs and phosphors to obtain specific color light is that such circuits are not required and the cost of LEDs is reduced. Therefore, many documents have made various specific proposals for phosphors with LEDs as light sources.

Currently commercialized white LEDs mainly use blue LEDs to excite YAG: Ce ³⁺ yellow phosphors, and the blue light emitted by the blue LEDs is mixed with the yellow light emitted by the phosphors to form white light. However, the red light component in the emission spectrum of YAG:Ce ³⁺ phosphor is insufficient, which makes it impossible to obtain low correlated color temperature (CCT<4500K) and high color rendering index (color rendering index) with a single YAG:Ce ³⁺ phosphor , CRI>80) of warm white light, so limit its application in indoor general lighting.

Generally speaking, in order to solve the above problem, it is necessary to add appropriate red light phosphors to the components to supplement the red light components, so as to prepare warm white LEDs with low color temperature and high color rendering index. However, currently commercialized red phosphors with better performance still have limitations such as wide emission bandwidth and high pressure for preparation, resulting in low lumen efficiency and high price.

Therefore, it is expected to develop a phosphor that contains more red light components than YAG:Ce ³⁺ phosphor, and has a wider emission spectrum at half maximum width, so that it can be used without the use of red phosphors. Next, combine with blue LED to prepare warm white LED with high color rendering index.

Contents of the invention

The purpose of the patent of the present invention is to solve the above problems and provide a phosphor powder composed of a compound doped with rare earth elements, a preparation method, a phosphor powder-containing composition, a light-emitting device using the phosphor powder, a display device, and a lighting device .

One object of the present invention is to provide a fluorescent powder, the chemical formula of which is (A _1-ab Gd _a Q _b ) ₃ M ₅ D ₁₂ , wherein

A is a group consisting of one or two of Lu or La;

Q is a group consisting of one or more of Ce, Nd, Sm, Pr, Dy, Ho, Er or Tm;

M is a group consisting of one or more of B, Al, Ga or In;

D is a group consisting of one or more of O, N, S, Cl or F;

And 0.4≤a≤0.53, 0.005≤b≤0.469;

The fluorescent powder is a crystalline phase crystal.

Preferably, said Q is a group consisting of one or more of Ce, Pr, or Sm.

Preferably, the D is one or two of O or N.

For example: (Lu _1-ab Gd _a Ce _b ) ₃ Al ₅ O ₁₂ , (La _1-ab Gd _a Ce _b ) ₃ Al ₅ O ₁₂ , (Lu _k La _1-ab Gd _a Ce _b ) ₃ Al ₅ O ₁₂ , wherein the ranges of a and b are as above, 0≤k≤0.6.

Preferably, the Q is a group composed of Ce and Pr, and the ratio of Ce to Pr is p:q; the chemical formula of the phosphor is (A _1-apq Gd _a Ce _p Pr _q ) ₃ M ₅ D ₁₂ , 0.4≤a≤0.53, 0.005≤p≤0.07, 0.001≤q≤0.02.

For example: (Lu _1-ab Gd _a Ce _p Pr _q ) ₃ Al ₅ O ₁₂ , (La _1-ab Gd _a Ce _p Pr _q ) ₃ Al ₅ O ₁₂ , (Lu _k La _1-ab Gd _a Ce _p Pr _q ) ₃ Al ₅ O ₁₂ , wherein the ranges of a, p, and q are as above, and 0≤k≤0.6.

Further, when the phosphor is excited by light with a wavelength of 430-460nm, its chromaticity coordinates x and y of the standard chromaticity system (CIE) are 0.420≤x≤0.600, 0.400≤y≤0.570, respectively .

Specifically, when the phosphor is excited by light with a wavelength of 430-460 nm, the wavelength of the emission peak is above 480 nm. Also, the full width at half maximum of the emission peak of the phosphor is 100 nm or more.

The phosphor powder of the present invention has a large emission peak with a full width at half maximum, and has sufficient luminous intensity in a region longer than the wavelength of yellow light (that is, about 600nm to 690nm), so when added to a blue LED, it can emit warm white light .

Another object of the present invention is to provide a method for manufacturing phosphor, comprising:

The raw material is sintered in a nitrogen-hydrogen mixed atmosphere to obtain a crystalline phosphor with the chemical formula (A _1-ab Gd _a Q _b ) ₃ M ₅ D ₁₂ ; the raw material contains a metal compound, and the The metal compound comprises at least one metal compound selected from Lu or La; the metal compound comprises at least one metal compound selected from Ce, Nd, Sm, Pr, Dy, Ho, Er or Tm; the metal compound comprises at least one One is selected from B, Al, Ga or In metal compounds.

Further, the raw materials are formed by mixing phosphor precursors, and the phosphor precursors are pulverized into particles with a particle size of 0.1 μm-30 μm by a dry pulverizer.

Specifically, the metal compound of the raw material may include: metal oxide, metal nitrate compound, metal carbonate compound, metal phosphate compound, metal acetate compound, metal oxalate compound, metal fluoride, Or one or a combination of metal chlorides.

In the present invention, specific examples of the Ce source include CeO ₂ , Ce ₂ (SO ₄ ) ₃ , Ce ₂ (C ₂ O ₄ ) ₃ , Ce ₂ (CO _{3 ) trihydrate, CeCl 3 , CeF 3 , Ce} (NO ₃ ) ₃ hydrate, CeN, Ce(OH) ₄ , etc. Among them, CeO ₂ and CeN are preferred.

Specific examples of the La source include, for example, lanthanum nitride, lanthanum oxide, lanthanum nitrate, lanthanum hydroxide, lanthanum oxalate, and lanthanum carbonate, among which lanthanum oxide is preferred.

Specific examples of the Gd source include gadolinium nitride, gadolinium oxide, gadolinium nitrate, gadolinium hydroxide, gadolinium oxalate, and gadolinium carbonate.

Specific examples of the Lu source include, for example, lutetium nitride, lutetium oxide, lutetium nitrate, lutetium oxalate, etc., and lutetium carbonate.

Specific examples of the Al source include AlN, Al ₂ O ₃ , Al, aluminum hydroxide, aluminum nitrate, and the like.

The weight average median diameter (D50) of each phosphor precursor is preferably not less than 0.5 μm and not more than 20 μm. Therefore, depending on the type of phosphor precursor, it may be pulverized in advance with a dry pulverizer such as a jet pulverizer. Thereby, uniform dispersion can be achieved in the mixture of each phosphor precursor, and the surface area of the phosphor precursor can be increased, so the solid-phase reactivity of the mixture can be improved, and the generation of impurity phase can be suppressed. In particular, when the phosphor precursor is a nitride, it is preferable to use a nitride having a smaller particle size than other phosphor precursors in view of reactivity.

Another object of the present invention is to provide a light-emitting device, including: a first luminous body, the light emitted by the first luminous body is blue light or UV; and a second luminous body, located on the first luminous body As soon as it comes out on the glossy surface. Wherein, the first phosphor contains at least one phosphor mentioned above.

Specifically, the first illuminant is an LED chip, a semiconductor laser diode, an organic electroluminescent element or an inorganic electroluminescent element.

Further, the luminous color rendering coefficient Ra of the first luminous body is greater than 80.

Preferably, in the light-emitting device, the second luminous body further includes a second phosphor, and the second phosphor includes at least one phosphor having a emission peak wavelength different from that of the first phosphor.

Specifically, if red phosphor is used as the second phosphor, the color rendering coefficient Ra of the emitted light can be greater than 90.

Specifically, if the second phosphor uses red phosphor and green phosphor, the color rendering coefficient Ra of the luminescence can be greater than 95.

To further illustrate the phosphor of the present invention, for example, the chemical formula (A _1-ab Gd _a R _b ) ₃ M ₅ D ₁₂ of the phosphor, when M is Al, wherein all or part of Al can be replaced by B . When raw materials are added to the BN container and sintered to produce the phosphor powder of the present invention, B can be mixed into the obtained phosphor powder, so that the above-mentioned phosphor powder in which Al is substituted with B can be produced.

The fluorescent powder of the present invention can emit yellow to orange light. When excited by light with a wavelength of 430-460nm, the chromaticity coordinates x and y of its standard chromaticity system (CIE) are usually: (0.420, 0.400), (0.420, 0.570), (0.600, 0.570) and ( 0.600, 0.400) in the area surrounded by coordinates. Preferably, the coordinates in the area surrounded by (0.440, 0.430), (0.440, 0.530), (0.580, 0.530) and (0.580, 0.430). Therefore, in the chromaticity coordinates of the fluorescence of the phosphor powder of the present invention, the chromaticity coordinate x is usually above 0.420, preferably above 0.440, and usually below 0.600, preferably below 0.580. On the other hand, the chromaticity coordinate y is usually 0.400 or more, preferably 0.430 or more, and usually 0.570 or less, preferably 0.530 or less.

The fluorescence spectrum (light emission spectrum) emitted by the phosphor powder of the present invention is not particularly limited, but as the purposes of yellow to orange phosphors, when excited by light with a wavelength of 430 to 460 nm, the emission peak wavelength of the light emission spectrum can be 480nm or more, preferably 560nm or more, more preferably 565nm or more, more preferably 570nm or more and may be in the range of 680nm or less, preferably 650nm or less, more preferably 625nm or less.

In the present invention, the external quantum efficiency of the phosphor can be above 30%, preferably above 35%, more preferably above 40%. In order to design a light-emitting element with high luminous intensity, the higher the external quantum efficiency, the better. In addition, the internal quantum efficiency of the phosphor powder of the present invention can be above 35%, preferably above 40%, more preferably above 45%. Here, the internal quantum efficiency refers to the ratio of the number of photons emitted by the phosphor to the number of photons of excitation light absorbed by the phosphor. When the internal quantum efficiency is low, the luminous efficiency is low. In addition, the higher the absorption efficiency of the phosphor of the present invention, the better. Its value may be 70% or more, preferably 75% or more, more preferably 80% or more. The external quantum efficiency is obtained from the product of the internal quantum efficiency and the absorption efficiency. In order to have a high external quantum efficiency, a high absorption efficiency is preferable.

In the light-emitting device of the present invention, the first luminous body can be used as a luminous body that excites the second luminous body described later.

Here, the emission wavelength of the first luminous body is not particularly limited as long as it overlaps with the absorption wavelength of the second luminous body described later, and luminous bodies in a wide emission wavelength region can be used. It is preferable to use an illuminant having an emission wavelength from the ultraviolet region to the blue region, more preferably to use an illuminant having an emission wavelength from the near-ultraviolet region to the blue region. As the specific value of the emission peak wavelength of the first luminous body, considering the color purity of the light-emitting device, it is preferably a luminous body with a peak emission wavelength of 430nm-480nm.

The compound of the first luminous body is preferably a GaN-based LED or LD using a GaN-based compound semiconductor. The reason is that GaN-based LEDs or LDs have higher luminous power and external quantum efficiency than SiC-based LEDs that emit light in this region, and can obtain very bright light emission with very low electric power through the above-mentioned compounds. . Among GaN-based LEDs or LDs, GaN-based LEDs or LDs having _Alx , _Gay , N light emitting layers, GaN light emitting layers, or _Inx , _Gay , N light emitting layers are preferred. Wherein, the value of x'+y' may range from 0.8 to 1.2. In GaN-based LEDs, elements such as Zn and Si can be doped in these light-emitting layers to adjust light-emitting characteristics.

Wherein, the LED is preferably a sandwich heterogeneous structure formed of a light emitting layer, a p layer, an n layer, electrodes and a substrate. In addition, only one first luminous body may be used, or two or more of the above-mentioned luminous bodies may be used in any combination and ratio.

The second luminous body in the light-emitting device of the present invention is a luminous body capable of emitting visible light under irradiation with light from the above-mentioned first luminous body. The second luminous body contains the above-mentioned fluorescent powder provided by the present invention as the first fluorescent powder, and may further include the second fluorescent powder described later, such as orange to red fluorescent powder, green fluorescent powder, blue fluorescent powder, etc. Phosphor, yellow phosphor, etc. In addition, for example, the second illuminant can be formed by dispersing the first and second phosphors in the encapsulation material.

For the above-mentioned second luminous body, except for the phosphor powder of the present invention, its composition is not particularly limited. Examples include incorporating a crystalline matrix into the compound, such as metal oxides such as Y ₂ O ₃ , YVO ₄ , Zn ₂ SiO ₄ , Y ₃ Al ₅ O ₁₂ , Sr ₂ SiO ₄ , Sr ₂ Si ₅ N ₈ and other metal nitrides, Ca ₅ (PO ₄ ) ₃ Cl phosphate, and ZnS, SrS, CaS sulfide, Y ₂ O ₂ S, La ₂ O ₂ S oxysulfide, etc., and add rare earth metals, For example, ions of Ce, Pr, Nd, Pm, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, etc., and or a metal, such as Ag, Cu, Au, Al, Mn, Sb, etc. Phosphors are formed as activating elements or co-activating elements.

Beneficial effects of the present invention:

(1) The fluorescent powder of the present invention is composed of a rare earth element doped compound, and the chemical formula of the fluorescent powder is (A _{1-a- b} Gd _a Q _b ) ₃ M ₅ D ₁₂ ; the fluorescent powder of the present invention has a large half High and wide emission peaks, and sufficient luminous intensity in a region longer than the wavelength of yellow light (ie, about 600nm to 690nm), when added to a blue LED, it can emit warm white light.

(2) The external quantum efficiency of the fluorescent powder of the present invention can be more than 30%, and can be used for light-emitting elements with high luminous intensity; the internal quantum efficiency of the fluorescent powder of the present invention can be more than 35%, and the luminous efficiency is high; the fluorescent powder of the present invention The absorption rate is more than 70%, and the absorption rate is high.

(3) In the preparation method of the phosphor powder of the present invention, the phosphor precursor is pulverized into particles with a particle size of 0.1 μm-30 μm through a dry pulverizer, so as to improve the solid-phase reactivity of the mixture and suppress the generation of impurity phases.

(4) In the light-emitting device of the present invention, the first luminous body is used as a luminous body that excites the second luminous body described later, thereby emitting warm white light.

(5) The phosphor powder of the present invention can be used in light-emitting devices, display devices or lighting devices, and provides more red light components, and has a wider emission spectrum at half maximum width, so that it can be used without using red light phosphor powder Under certain conditions, it can be combined with blue LEDs to prepare warm white LEDs with high color rendering index, so it can improve the problem of low lumen efficiency caused by the use of red phosphors and help reduce costs.

detailed description

The following specific examples are used to further illustrate the method described in the present invention, but it does not mean that the present invention is limited to these examples.

Example 1

Preparation of fluorescent powder: After mixing compounds containing lutetium oxide (Lu ₂ O ₃ ), gadolinium oxide (Gd ₂ O ₃ ), aluminum oxide (Al ₂ O ₃ ) and cerium oxide (CeO ₂ ) in a predetermined ratio ( The mixing time is about 0.5 hours to 24 hours), filled into the crucible for high-temperature sintering reaction, the sintering temperature is between 1400-1700 °C, under the nitrogen-hydrogen mixture, sintering for 0.5-24 hours, after the sintering is completed, it is lowered to room temperature and taken out , and then ground in a ball mill, and the particle size was sorted by a centrifugal atomizer to obtain (Lu _0.38 Gd _0.53 Ce _0.09 ) ₃ Al ₅ O ₁₂ powder.

Example 2

Preparation of fluorescent powder: will contain lutetium oxide (Lu ₂ O ₃ ), gadolinium oxide (Gd ₂ O ₃ ), aluminum oxide (Al ₂ O ₃ ), cerium oxide (CeO ₂ ), and praseodymium oxide (Pr ₂ O ₃ ) and Or praseodymium fluoride and other compounds are uniformly mixed according to a predetermined ratio (mixing time is about 0.5 hours to 24 hours), filled into a crucible for high-temperature sintering reaction, the sintering temperature is between 1400-1700 ° C, in nitrogen-hydrogen mixed gas sintering for 0.5 to 24 hours, after the sintering was completed and cooled down to room temperature, it was taken out, then ground in a ball mill, and the particle size was sorted by a centrifugal atomizer to obtain (Lu _0.38 Gd _0.53 Ce _0.07 Pr _0.02 ) ₃ Al ₅ O ₁₂ powder.

Example 3

Phosphor powder prepared in Test Example 1:

The (Lu _0.38 Gd _0.53 Ce _0.09 ) ₃ Al ₅ O ₁₂ powder with a D50 particle size of 14 μm was measured by a fluorescence spectrometer. Let the light from the excitation light source pass through a grating monochromator with a focal length of 10 cm, and then irradiate the phosphor with excitation light with a wavelength of 460 nm. The light generated by the phosphor powder under the irradiation of excitation light passes through a grating monochromator with a focal length of 25cm to measure the luminous intensity of each wavelength in the wavelength range of 450nm to 700nm, and the peak λp=585nm in the fluorescence emission spectrum.

The full width at half maximum of the emission peak was calculated from the emission spectrum obtained by the method described above.

For the measurement of the chromaticity coordinates of the x, y colorimetric system (CIE 1931 colorimetric system), from the data of the wavelength range of 450nm to 700nm of the emission spectrum obtained by the above method, the method based on JIS Z8724 is used to calculate Chromaticity coordinates x and y in the XYZ chromaticity system specified in JISZ8701. The chromaticity coordinates (x, y)=(0.510, 0.482) are obtained.

Example 4

Phosphor powder prepared in Test Example 2:

The (Lu _0.38 Gd _0.53 Ce _0.07 Pr _0.02 ) ₃ Al ₅ O ₁₂ powder with a D50 particle size of 14 μm was measured by a fluorescence spectrometer, and the rest of the conditions were the same as in Test Example 1. In the fluorescence emission spectrum, the peak λp1=585nm, λp2=610nm, λp3=640nm.

The full width at half maximum of the emission peak was calculated from the emission spectrum obtained by the method described above.

For the measurement of the chromaticity coordinates of the x, y colorimetric system (CIE 1931 colorimetric system), from the data of the wavelength range of 450nm to 700nm of the emission spectrum obtained by the above method, the method based on JIS Z8724 is used to calculate Chromaticity coordinates x and y in the XYZ chromaticity system specified in JISZ8701. The obtained chromaticity coordinates are (x, y)=(0.501, 0.488).

As with the foregoing embodiments, it should be understood that the purpose thereof is to illustrate the present invention, not to limit it. Furthermore, based on the aforementioned results, the present invention provides a phosphor powder composed of a complex doped with rare earth elements and a manufacturing method, thereby solving the problems of the prior art.

Example 5

A fluorescent powder, the chemical formula of which is (A _1-ab Gd _a Q _b ) ₃ M ₅ D ₁₂ , wherein A is a group consisting of one or two of Lu or La; Q is Ce, A group consisting of one or more of Nd, Sm, Pr, Dy, Ho, Er or Tm;

M is a group consisting of one or more of B, Al, Ga or In;

D is a group consisting of one or more of O, N, S, Cl or F;

And 0.4≤a≤0.53, 0.005≤b≤0.469; the fluorescent powder is a crystalline phase crystal.

Preferably, said Q is a group consisting of one or more of Ce, Pr, or Sm.

Preferably, the D is one or two of O or N.

Further, when the phosphor is excited by light with a wavelength of 430-460nm, its chromaticity coordinates x and y of the standard chromaticity system (CIE) are 0.420≤x≤0.600, 0.400≤y≤0.570, respectively .

Specifically, when the phosphor is excited by light with a wavelength of 430-460 nm, the wavelength of the emission peak is above 480 nm. In addition, the FWHM of the emission peak of the phosphor is 100 nm or more, and in the present invention, the FWHM of the emission peak of the phosphor is 130 nm or more.

The phosphor powder of the present invention has a large emission peak with a full width at half maximum, and has sufficient luminous intensity in a region longer than the wavelength of yellow light (that is, about 600nm to 690nm), so when added to a blue LED, it can emit warm white light .

In this embodiment, the chemical formula of the phosphor can be (Lu _1-ab Gd _a Ce _b ) ₃ Al ₅ O ₁₂ , (La _1-ab Gd _a Ce _b ) ₃ Al ₅ O ₁₂ , (Lu _k La _1-ab Gd _a Ce _b ) ₃ Al ₅ O ₁₂ , wherein, 0.4≤a≤0.53, 0.005≤b≤0.469; 0≤k≤0.6. Specifically, in this embodiment, the chemical formula of the fluorescent powder is (Lu _0.38 Gd _0.53 Ce _0.09 ) ₃ Al ₅ O ₁₂ .

Example 6

A fluorescent powder, the chemical formula of which is (A _1-ab Gd _a Q _b ) ₃ M ₅ D ₁₂ , wherein A is a group consisting of one or two of Lu or La; Q is Ce, A group consisting of one or more of Nd, Sm, Pr, Dy, Ho, Er or Tm; M is a group consisting of one or more of B, Al, Ga or In;

D is a group consisting of one or more of O, N, S, Cl or F;

And 0.4≤a≤0.53, 0.005≤b≤0.469; the fluorescent powder is a crystalline phase crystal.

Preferably, the D is one or two of O or N.

Preferably, the Q is a group composed of Ce and Pr, and the ratio of Ce to Pr is p:q; the chemical formula of the phosphor is (A _1-apq Gd _a Ce _p Pr _q ) ₃ M ₅ D ₁₂ , 0.4≤a≤0.53, 0.005≤p≤0.07, 0.001≤q≤0.02.

The chemical formula of the phosphor can be (Lu _1-ab Gd _a Ce _p Pr _q ) ₃ Al ₅ O ₁₂ , (La _1-ab Gd _a Ce _p Pr _q ) ₃ Al ₅ O ₁₂ , (Lu _k La _1-ab Gd _a Ce _p Pr _q ) ₃ Al ₅ O ₁₂ , wherein, 0.4≤a≤0.53, 0.005≤p≤0.07, 0.001≤q≤0.02, 0≤k≤0.6. Specifically, the chemical formula of the phosphor in this embodiment is (Lu _0.38 Gd _0.53 Ce _0.07 Pr _0.02 ) ₃ Al ₅ O ₁₂ .

Example 7

The phosphor powders prepared in Example 1 and Example 2 were respectively applied to light-emitting devices.

A lighting device comprising:

The first luminous body, the light emitted by the first luminous body is blue light or UV;

the second luminous body is arranged on one of the light emitting surfaces of the first luminous body;

Wherein, the second luminous body includes a first phosphor, and the first phosphor includes at least one phosphor with a chemical formula of (A _1-ab Gd _a Q _b ) ₃ M ₅ D ₁₂ .

Specifically, the first phosphor is the phosphor prepared in Example 1 and Example 2. The first luminous body is an LED chip, and its luminous color rendering coefficient Ra is greater than 80.

Specifically, the second luminous body is formed by dispersing the first fluorescent powder in the packaging material.

The second luminous body in the light-emitting device of the present invention is a luminous body capable of emitting visible light under irradiation with light from the above-mentioned first luminous body.

The above examples are only specific examples of the present invention, and obviously, the present invention is not limited to the above examples. All deformations that can be directly derived or associated by those skilled in the art from the content disclosed in the present invention shall belong to the protection scope of the present invention.

Claims (10)

1. A fluorescent powder, characterized in that the chemical formula of the fluorescent powder is (A _1-ab Gd _a Q _b ) ₃ M ₅ D ₁₂ , wherein A is a group consisting of one or two of Lu or La; Q is a group consisting of any one or more of Ce, Nd, Sm, Pr, Dy, Ho, Er or Tm; M is a group consisting of any one or more of B, Al, Ga or In; D is a group consisting of any one or more of O, N, S, Cl or F; And 0.4≤a≤0.53, 0.005≤b≤0.469; The fluorescent powder is a crystalline phase crystal. 2 . The phosphor according to claim 1 , wherein the Q is any one or more than one of Ce, Pr, or Sm. 3. The phosphor according to claim 1 or 2, wherein the D is any one of O or N or a group consisting of both. 4. The fluorescent powder according to claim 1, wherein the Q is a group composed of Ce and Pr, and the ratio of the number of elements between Ce and Pr is p:q; the chemical formula of the fluorescent powder is (A _1-apq Gd _a Ce _p Pr _q ) ₃ M ₅ D ₁₂ , 0.4≤a≤0.53, 0.005≤p≤0.07, 0.001≤q≤0.02. 5. a preparation method of the phosphor powder described in any one of claims 1-4, is characterized in that, raw material is sintered under nitrogen-hydrogen mixed atmosphere environment, to obtain chemical formula as (A _1-ab Gd _a Q _b ) Phosphor powder in the crystal phase of ₃ M ₅ D ₁₂ ; the raw material contains a metal compound, and the metal compound contains at least one metal compound selected from Lu or La; the metal compound contains at least one metal compound selected from Ce, Nd, Sm, Pr, Dy, Ho, Er or Tm metal compound; the metal compound contains at least one metal compound selected from B, Al, Ga or In. 6. The preparation method of phosphor powder according to claim 5, characterized in that, the raw material is formed by mixing phosphor precursors, and the phosphor precursors are pulverized into a particle size of 0.1 μm by a dry pulverizer -30 μm particles. 7. A lighting device, characterized in that it comprises: The first luminous body, the light emitted by the first luminous body is blue light or UV; the second luminous body is arranged on one of the light emitting surfaces of the first luminous body; Wherein, the second luminous body comprises a first phosphor, and the first phosphor comprises at least one phosphor according to any one of claims 1-4. 8. The light-emitting device according to claim 7, wherein the second luminous body further comprises a second phosphor, and the second phosphor comprises at least one emission peak wavelength similar to that of the first phosphor different phosphors. 9. The light emitting device according to claim 7 or 8, wherein the first luminous body is an LED chip, a semiconductor laser diode, an organic electroluminescent element or an inorganic electroluminescent element. 10. A phosphor applied to a light-emitting device, a display device or a lighting device, characterized in that it comprises the phosphor according to any one of claims 1-4.