CN113136204A - Eu (Eu)2+-Mn2+Co-doped fluorescent powder and preparation method and application thereof - Google Patents

Abstract

The invention provides Eu²⁺‑Mn²⁺Co-doped fluorescent powder and preparation method and application thereof, wherein the chemical general formula of the fluorescent powder is A_aM_11‑zO_17+b:yEu²⁺,zMn²⁺Wherein A is any one or combination of more of Li, Na, K and Rb, M is any one or combination of two of Al and Ga, and y is more than or equal to 0.01 and less than or equal to 0.3, and 0<z is less than or equal to 1, a is less than or equal to 2 and b is less than or equal to 1 and more than or equal to 0. The fluorescent powder in the invention is Eu²⁺、Mn²⁺Co-doped series phosphor using Eu²⁺As sensitizer to promote Mn²⁺Thereby realizing efficient and thermally stable Mn²⁺The fluorescent powder has the characteristics of a broadband excitation spectrum and a narrow-band emission spectrum in a near ultraviolet region, can be used for preparing an excellent fluorescence conversion type white light LED device, has a simple preparation method, and is easy to realizeAnd (4) industrial production.

Description

Eu (Eu)2+-Mn2+Co-doped fluorescent powder and preparation method and application thereof

Technical Field

The invention belongs to the technical field of fluorescent powder, and particularly relates to Eu²⁺-Mn²⁺Codoped fluorescent powder and a preparation method and application thereof.

Background

Light Emitting Diodes (LEDs) have become the first choice for a new generation of illumination sources and Liquid Crystal Display (LCD) backlights because of their many advantages. When the LED is used for an LCD backlight source, the light efficiency of a green light LED is far lower than that of a blue light LED and a red light LED, and under the condition that the light efficiency of a green light chip is difficult to improve, in order to improve the overall light efficiency and increase the color gamut of the LCD backlight source, efficient narrow-band green light fluorescent powder is developed and combined with a proper chip to replace an inefficient green light chip, so that the optimal choice for improving the performance of the LCD backlight source is provided.

Activated ion Eu²⁺、Ce³⁺With Mn²⁺Has very important function on the spectral regulation of the fluorescent powder. Although Eu is²⁺Activated nitrogen (oxide) green phosphors have high stability and high quantum efficiency, but often have emission half-widths greater than 50nm, and the color gamut of the corresponding devices is less than 90% of the international television standards committee (NTSC) standard. Found in Liwanyuan et al, Si_{6- z}Al_zO_zN_8-z:Eu²⁺(γ-SiAlON:Eu²⁺) The emission half-width of (a) decreases with decreasing z (46.9 nm for z 0.1), and the color gamut of the corresponding LED device is 95.4% of the NTSC standard. Recently, summer et al discovered UCr for narrow-band green emission₄C₄Type phosphor RbLi (Li)₃SiO₄)₂:Eu²⁺Peak (P) and half-peak width (W) of 530 and 42nm, respectively, UCr₄C₄A type narrow-band green light fluorescent powder,such as RbNa (Li)₃SiO₄)₂:Eu²⁺(P523/W41nm) and NaK₇[Li₃SiO₄]₈:Eu²⁺(P515/W49nm), and Eu is used therefor^{2 +}Narrower green emission is more difficult to achieve with the activating ions. With Eu²⁺In contrast, Ce³⁺Narrow-band emission is more difficult to achieve due to the splitting of the ground state 4f level, whose emission spectrum comes from the superposition of two emission bands. Therefore, the development of narrow-band green phosphors based on other active ions is urgently needed.

The study shows that when Mn is used²⁺Can emit green light when being positioned at the central cation lattice site of which the coordination polyhedron is a tetrahedron, and can provide specific Eu²⁺Narrower emission bands, e.g. Na₂ZnSiO₄:Mn²⁺(P515/W30nm)、ZnB₂O₄:Mn²⁺(P541/W41nm)、NaAl₁₁O₁₇:Mn²⁺(P508/W35nm)、Cs₃MnBr₅:Mn²⁺(P520/W42nm)、Sr₂MgAl₂₂O₃₆:Mn²⁺(P518/W26nm) and MgAl₂O₄:Mn²⁺(P520-530/W31-40 nm). Using Mn²⁺The color gamut of the display LED device made of the activated narrow-band green-light fluorescent powder as a green light component can reach more than 110% of the NTSC standard theoretically, but the d-d transition is forbidden, the transition probability is small, and Mn is difficult to pass through²⁺The single doping of (2) results in narrow-band green emission with high luminous efficiency.

Disclosure of Invention

Single Mn doping due to 3d-3d transition of steric inhibition²⁺The narrow-band green light emitting fluorescent powder has low luminous efficiency, so that the application of the fluorescent powder as a green light component in an LED backlight source is prevented, and therefore, the invention provides the Eu for solving the problem²⁺-Mn²⁺Co-doped fluorescent powder and preparation method and application thereof, wherein the fluorescent powder utilizes Eu²⁺As sensitizer to promote Mn²⁺Thereby realizing efficient and thermally stable Mn²⁺Narrow-band green emission is activated.

In order to solve the technical problems, the technical scheme provided by the invention is as follows:

eu (Eu)²⁺-Mn²⁺Co-doped fluorescent powder with a chemical general formula A_aM_11-zO_17+b:yEu²⁺,zMn²⁺Wherein A is any one or combination of more of Li, Na, K and Rb, M is any one or combination of two of Al and Ga, and y is more than or equal to 0.01 and less than or equal to 0.3, and 0<z is less than or equal to 1, a is less than or equal to 2 and b is less than or equal to 1 and more than or equal to 0. The value of b is used to maintain compound electroneutrality.

The fluorescent powder consists of a substrate A_aM_11-zO_17+bAnd a luminescence center Eu²⁺With Mn²⁺Two parts, wherein Eu²⁺As a sensitizer to transfer the excited state energy to Mn²⁺Any matrix with Eu in proper concentration²⁺And Mn²⁺Combining to obtain the Eu^{2 +}-Mn²⁺And co-doping the fluorescent powder. For example, the chemical formula of the phosphor can be specifically (Na)_1-xK_x)_aAl_11-zO_17+b:yEu²⁺,zMn²⁺Wherein x is more than or equal to 0 and less than or equal to 1, and the fluorescent powder matrix is obtained by solid solution of full Na poly-aluminate and full K poly-aluminate according to any proportion.

4f-5d transition, Eu, allowed based on space balance²⁺The excited and emitted fluorescent powder has the characteristics of large intensity, adjustable wavelength range and the like, so that the activated fluorescent powder can be used as a sensitizer to improve Mn²⁺The luminous efficiency of the fluorescent powder is activated. When Mn is present²⁺When emitting narrow-band green light, it has a wide excitation band around 450nm, corresponding to Mn²⁺Is/are as follows⁶A₁(6S) to⁴T₂(4G) Is detected. Depending on the energy transfer conditions, efficient Eu is to be achieved²⁺To Mn²⁺Energy transfer of, the selection of Eu being required²⁺The emission band of (a) is located at a phosphor near 450 nm. Thus highly efficient, thermally stable Eu²⁺Is Mn which realizes high efficiency and thermal stability²⁺The emission of narrow-band green light is guaranteed.

The invention selects A_aM_11-zO_17+bProviding a lattice site A (A is one or combination of alkali metal elements Li, Na, K and Rb) with a proper coordination environment for the substrate of the fluorescent powder to ensure that Eu is²⁺The blue light with peak value near 450nm can be emitted when occupying the lattice position, and the structure contains MO₄Lattice sites available for Mn²⁺Occupying to realize narrow-band green light emission and utilizing Mn²⁺Excitation band in blue region and Eu²⁺The emission bands of (2) are highly overlapped to realize high-efficiency Mn²⁺Narrow-band green emission. In the general formula of the phosphor, the value range of a is used for ensuring the formation of P6₃The value of y is taken for both ensuring the target phase and efficient blue emission (high Eu) of the target phase of the/mmc space group²⁺Doping concentration can cause phase change and reduction of luminous intensity), and the value range of z is based on Mn²⁺Too high a doping concentration may result in the setting for concentration quenching.

The matrix lattice of the fluorescent powder is hexagonal phase, and the space group is P6₃/mmc。

When z is more than or equal to 0.14, the fluorescent powder emits green fluorescence mainly with an emission band of 480-550nm under the excitation of ultraviolet light with the wavelength of 250-420nm, the emission band is a green emission band with the peak value positioned at 505-515nm, and the emission half-peak width is 20-30 nm;

when the z is more than 0 and less than 0.14, the fluorescent powder emits 400-550nm blue-green fluorescence under the excitation of ultraviolet light with the wavelength of 250-420nm, and comprises two emission bands, wherein one emission band is a blue light emission band with the peak value at 440-480nm and the half-peak width is 50-75nm, the other emission band is a green light emission band with the peak value at 505-515nm and the emission half-peak width is 20-30 nm.

As a general technical concept, the invention also provides Eu²⁺-Mn²⁺The preparation method of the co-doped fluorescent powder comprises the following steps:

(1) according to the general formula A_aM_11-zO_17+b:yEu²⁺,zMn²⁺Respectively weighing a compound containing A, a compound containing M, a compound containing europium, a compound containing manganese and a fluxing agent accounting for 3-7% of the total mass of the raw materials;

(2) grinding and uniformly mixing the raw materials weighed in the step (1) to obtain a mixture; heating the mixture to 1100-1600 ℃ in a reducing atmosphere, roasting for 3-5h, and coolingCooling to room temperature, and grinding to obtain the Eu²⁺-Mn²⁺And co-doping the fluorescent powder.

Preferably, in the step (1), the compound containing a is any one or a combination of several of carbonate, bicarbonate and oxalate of a, for example, when a is Na, the compound containing a may be specifically Na₂CO₃(with or without water of crystallization) NaHCO₃、Na₂C₂O₄When A is K, the compound containing A can be K₂CO₃(with or without crystal water), KHCO₃、K₂C₂O₄Any one or a combination of several of them;

the M-containing compound is any one or combination of hydroxides and oxides of M, for example, when M is Al, the M-containing compound can be specifically Al (OH)₃、Al₂O₃Either one or a combination of both;

the europium-containing compound is Eu₂O₃、EuCl₃、Eu(NO₃)₃Any one or a combination of several of them;

the manganese-containing compound is MnCO₃、MnO₂Either one or a combination of both;

the fluxing agent is H₃BO₃、CaF₂、SrF₂、BaF₂、(NH₄)₂CO₃Any one or a combination of several of them.

Preferably, in the step (2), the temperature is raised to 1100-1600 ℃ at an average temperature rise rate of 4-6.5 ℃/min.

Preferably, in the step (2), the reducing atmosphere is H₂And N₂The mixed gas of (1), said H₂And N₂In a volume ratio of 5:95 to 10: 90.

As a general technical concept, the invention also provides the Eu²⁺-Mn²⁺Co-doped fluorescent powder and Eu prepared by using preparation method²⁺-Mn²⁺Co-doped fluorescent powder for manufacturing white lightIn an LED device.

Preferably, the specific applications include: when z is more than or equal to 0.14, adding the Eu²⁺-Mn²⁺Mixing the codoped fluorescent powder with blue fluorescent powder and red fluorescent powder, and packaging the mixture on a near ultraviolet LED chip to manufacture a white light LED device;

when 0 is present<z<0.14 hr, adding the Eu²⁺-Mn²⁺And mixing the co-doped fluorescent powder and the red fluorescent powder, and packaging the mixture on a near ultraviolet LED chip to manufacture a white light LED device.

Compared with the prior art, the invention has the beneficial effects that:

1. the fluorescent powder in the invention is Eu²⁺、Mn²⁺The co-doped series fluorescent powder has the characteristics of a broadband excitation spectrum and a narrow-band emission spectrum in a near ultraviolet region, and a main excitation band is positioned at 250-420nm and comes from Eu²⁺Characteristic 4f-5d transition. When z is more than or equal to 0.14, the fluorescent powder emits green fluorescence mainly with an emission band of 480-550nm under the excitation of ultraviolet light with the wavelength of 250-420nm, and the emission band is a green emission band (Mn) with the peak value positioned at 505-515nm²⁺Emission of (c); when 0 is present<z<0.14, the phosphor powder emits 400-550nm blue-green fluorescence under the excitation of 250-420nm wavelength ultraviolet light, and comprises two emission bands, wherein one emission band is a blue light emission band (Eu) with a peak at 440-480nm²⁺Emission) of (1), and the other emission band is a green emission band (Mn) having a peak at 505-515nm²⁺Transmission of (c). The emission half-peak width of the green light emission band in the fluorescent powder is 20-30nm, and the intensity of the blue light emission band is dependent on Mn²⁺Gradually decreases and eventually disappears.

2. The invention can obtain the fluorescent powder with high efficiency and thermal stability by adjusting the values of y, z, a and the like. The internal quantum efficiency of the fluorescent powder can be up to 90 percent, the external quantum efficiency can be up to nearly 70 percent, when the temperature reaches 150 ℃, the luminous intensity is still higher than the room temperature value, the zero thermal quenching phenomenon appears, and the luminous intensity is still higher than 90 percent of the room temperature value at 150 ℃ after three times of heating-cooling circulation. Using Eu²⁺-Mn²⁺Energy transfer is realized from Mn²⁺The narrow-band green light emission intensity (or quantum efficiency) and thermal stability are improved. The invention isThe doped system has high efficiency and high thermal stability, and the narrow-band green light emission enables the fluorescent powder to be used for manufacturing an LED backlight source with wide color gamut.

3. Preparation of Eu according to the invention²⁺、Mn²⁺When co-doping series fluorescent powder, the used raw materials are cheap and easy to obtain, the preparation of the product can be finished by one-time roasting, the method is simple, the industrial production is easy to realize, and the prepared product has uniform granularity and stable structure. The added fluxing agent can promote ion diffusion, improve the reaction rate, and reduce the reaction temperature and energy consumption.

4. Eu in the invention²⁺、Mn²⁺The co-doped series fluorescent powder is mixed with other fluorescent powder and can be used for preparing an excellent wide-color-gamut fluorescence conversion type white light LED device.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is an XRD pattern of the phosphor in example 1 of the present invention;

FIG. 2 shows the excitation spectrum and emission spectrum of the phosphor of example 1 of the present invention;

FIG. 3 is a thermal stability analysis chart of the phosphor in example 1 of the present invention;

FIG. 4 is a graph showing three-cycle thermal stability analysis of the phosphor of example 1 of the present invention;

FIG. 5 is a graph showing the results of quantum efficiency tests of the phosphor of example 1 of the present invention;

FIG. 6 is an XRD pattern of the phosphor in example 2 of the present invention;

FIG. 7 shows the excitation spectrum and emission spectrum of the phosphor in example 2 of the present invention;

FIG. 8 is a thermal stability analysis chart of the phosphor in example 2 of the present invention;

FIG. 9 is a graph of the quantum efficiency of the phosphor of example 2 of the present invention;

FIG. 10 is a color gamut diagram and an electroluminescence spectrum of a white LED device prepared in example 6 of the present invention;

fig. 11 is an electroluminescence spectrum of a white LED device prepared in example 7 of the present invention.

Detailed Description

In order to facilitate understanding of the invention, the invention will be described more fully and in detail with reference to the accompanying drawings and preferred embodiments, but the scope of the invention is not limited to the specific embodiments below.

Unless otherwise defined, all terms of art used hereinafter have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention.

Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment and the like used in the present invention are commercially available or can be prepared by existing methods.

Example 1: preparation of Na_1.6Al_10.7O_17.35:0.2Eu²⁺,0.3Mn²⁺

The preparation method specifically comprises the following steps:

(1) weighing Na according to the stoichiometric ratio of the elements₂CO₃(A.R.)、Al(OH)₃(A.R.)、Eu₂O₃(99.99%) with MnCO₃(A.R.), and further weighing H accounting for 5w percent of the total mass of the raw materials₃BO₃As a flux.

(2) Grinding and uniformly mixing the raw materials weighed in the step (1) for 25 minutes to obtain a mixture; the mixture was charged into a crucible, the crucible was pushed into a tube-type high-temperature furnace, and a mixed gas of nitrogen and hydrogen (95% N) was introduced₂+5％H₂Volume percent), temperature programming, heating to 1300 ℃ at an average heating rate of 5 ℃/min, roasting for 4 hours at 1300 ℃, stopping heating, continuing introducing nitrogen gas for cooling to room temperature, taking out, and slightly grinding to obtain the target fluorescent powder Na_1.6Al_10.7O_17.35:0.2Eu²⁺,0.3Mn²⁺。

The phase composition of the phosphor is shown in FIG. 1, and XRD diffraction peak value and space group are P6₃NaAl of/mmc₁₁O₁₇The standard card PDF #79-2288 completely corresponds to the standard card PDF #79-2288, which indicates that the space group P6 can be prepared under the condition₃A pure phase of the target product per mm.

The characteristic excitation spectrum and the emission spectrum of the fluorescent powder are shown in figure 2, and the result shows that the fluorescent powder can emit narrow-band green light under the excitation of near ultraviolet light, which indicates that the prepared fluorescent powder has high-efficiency Eu²⁺→Mn²⁺Energy transfer of (2).

The emission spectrum and the relationship between the intensity and the temperature, i.e., the thermal stability result of the phosphor is shown in fig. 3, when the temperature reaches 150 ℃, the integrated luminous intensity is still higher than the room temperature value, and the zero quenching phenomenon occurs.

The intensity versus temperature relationship for three "heating-cooling" cycles of the phosphor is shown in fig. 4, with the luminous intensity at 150 ℃ being greater than 90% of the pre-cycle temperature value.

The quantum efficiency test spectrum of the phosphor is shown in fig. 5, in which the internal quantum efficiency is 74% and the external quantum efficiency is 51%.

Example 2: preparation K_1.6Al_10.86O_17.43:0.2Eu²⁺,0.14Mn²⁺

The preparation method specifically comprises the following steps:

(1) weighing K according to the stoichiometric ratio of elements₂CO₃(A.R.)、Al(OH)₃(A.R.)、Eu₂O₃(99.99%) with MnCO₃(A.R.), and further weighing H accounting for 5w percent of the total mass of the raw materials₃BO₃As a flux.

(2) Grinding and uniformly mixing the raw materials weighed in the step (1) for 20 minutes to obtain a mixture; the mixture was charged into a crucible, the crucible was pushed into a tube-type high-temperature furnace, and a mixed gas of nitrogen and hydrogen (95% N) was introduced₂+5％H₂Volume percent), temperature programming, heating to 1300 ℃ at an average heating rate of 5 ℃/minute, roasting at 1300 ℃ for 4 hours, stopping heating, and continuing to heatIntroducing nitrogen gas to cool to room temperature, taking out and slightly grinding to obtain the target fluorescent powder K_1.6Al_10.86O_17.43:0.2Eu²⁺,0.14Mn²⁺。

The phase composition of the phosphor is shown in FIG. 6, and XRD diffraction peak and space group are P6₃K of/mmc_1.44Al_10.88O_17.23The standard card PDF #84-0819 of (A) corresponds completely, indicating that the target pure phase is synthesized.

The characteristic excitation spectrum and emission spectrum of the phosphor are shown in FIG. 7, which can emit narrow-band green light under near ultraviolet excitation, thus demonstrating the successful realization of efficient Eu²⁺→Mn²⁺And (4) energy transfer is carried out to obtain the narrow-band green light emitting fluorescent powder under the excitation of near ultraviolet light.

The thermal stability results of the phosphors are shown in fig. 8, and when the temperature reaches 150 ℃, the integrated luminescence intensity is 97.6% of the room temperature value, and the zero quenching phenomenon also occurs below 150 ℃.

The quantum efficiency test spectrum of the phosphor is shown in FIG. 9, and the internal quantum efficiency is as high as 90.4% (far higher than that of singly doped Mn)²⁺41% of the total time), the external quantum efficiency is up to 69.5%.

Example 3: preparation K_1.6Al_10.98O_17.49:0.2Eu²⁺,0.02Mn²⁺

The preparation method specifically comprises the following steps:

(1) weighing K according to the stoichiometric ratio of elements₂CO₃(A.R.)、Al(OH)₃(A.R.)、Eu₂O₃(99.99%) with MnCO₃(A.R.), and further weighing H accounting for 5w percent of the total mass of the raw materials₃BO₃As a flux.

(2) Grinding and uniformly mixing the raw materials weighed in the step (1) for 20 minutes to obtain a mixture; the mixture was charged into a crucible, the crucible was pushed into a tube-type high-temperature furnace, and a mixed gas of nitrogen and hydrogen (95% N) was introduced₂+5％H₂% is volume percent), temperature programming, heating to 1400 ℃ at the average heating rate of 5 ℃/minute, roasting for 4 hours at 1400 ℃, then stopping heating, continuing introducing nitrogen gas to cool to room temperature, taking out and slightly grinding,obtaining the target phosphor K_1.6Al_10.98O_17.49:0.2Eu²⁺,0.02Mn²⁺。

Example 4: preparation K_1.0Na_0.6Al_10.7O_17.35:0.2Eu²⁺,0.3Mn²⁺

The preparation method specifically comprises the following steps:

(1) weighing K according to the stoichiometric ratio of elements₂CO₃(A.R.)、Na₂CO₃(A.R.)、Al(OH)₃(A.R.)、Eu₂O₃(99.99%) with MnCO₃(A.R.), and further weighing H accounting for 5w percent of the total mass of the raw materials₃BO₃As a flux.

(2) Grinding and uniformly mixing the raw materials weighed in the step (1) for 25 minutes to obtain a mixture; the mixture was charged into a crucible, the crucible was pushed into a tube-type high-temperature furnace, and a mixed gas of nitrogen and hydrogen (95% N) was introduced₂+5％H₂Volume percent), temperature programming, heating to 1350 ℃ at an average heating rate of 5 ℃/min, roasting for 4 hours at 1350 ℃, stopping heating, introducing nitrogen gas continuously to cool to room temperature, taking out, and slightly grinding to obtain the target fluorescent powder K_1.0Na_0.6Al_10.7O_17.35:0.2Eu²⁺,0.3Mn²⁺。

Example 5: preparation K_1.6Al_10.82O_17.41:0.2Eu²⁺,0.18Mn²⁺

The preparation method specifically comprises the following steps:

(1) weighing K according to the stoichiometric ratio of elements₂CO₃(A.R.)、Al(OH)₃(A.R.)、Eu₂O₃(99.99%) with MnCO₃(A.R.), and further weighing H accounting for 5w percent of the total mass of the raw materials₃BO₃As a flux.

(2) Grinding the raw materials weighed in the step (1) for 30 minutes and uniformly mixing to obtain a mixture; the mixture was charged into a crucible, the crucible was pushed into a tube-type high-temperature furnace, and a mixed gas of nitrogen and hydrogen (95% N) was introduced₂+5％H₂% by volume), temperature programming at 5 deg.CHeating to 1300 ℃ at the average heating rate per minute, roasting for 3.5 hours at 1300 ℃, stopping heating, introducing nitrogen gas continuously for cooling to room temperature, taking out, and slightly grinding to obtain the target fluorescent powder K_1.6Al_10.82O_17.41:0.2Eu²⁺,0.18Mn²⁺。

Example 6: preparation of Na_0.5Li_0.5Al_10.8O_17.1:0.2Eu²⁺,0.2Mn²⁺

The preparation method specifically comprises the following steps:

(1) weighing Na according to stoichiometric ratio₂CO₃(A.R.)、Li₂CO₃(A.R.)、Al(OH)₃(A.R.)、Eu₂O₃(99.99%) with MnCO₃(A.R.), and further weighing H accounting for 5w percent of the total mass of the raw materials₃BO₃As a flux.

(2) Grinding the raw materials weighed in the step (1) for 30 minutes and uniformly mixing to obtain a mixture; the mixture was charged into a crucible, the crucible was pushed into a tube-type high-temperature furnace, and a mixed gas of nitrogen and hydrogen (95% N) was introduced₂+5％H₂Volume percent), temperature programming, heating to 1300 ℃ at an average heating rate of 5 ℃/min, roasting for 4 hours at 1300 ℃, stopping heating, continuing introducing nitrogen gas for cooling to room temperature, taking out, and slightly grinding to obtain the target fluorescent powder Na_0.5Li_0.5Al_10.8O_17.1:0.2Eu²⁺,0.2Mn²⁺。

Example 7: preparation of Rb_1.2Al_10.7O_17.15:0.2Eu²⁺,0.3Mn²⁺

The preparation method specifically comprises the following steps:

(1) weighing Rb according to stoichiometric ratio₂CO₃(A.R.)、Al(OH)₃(A.R.)、Eu₂O₃(99.99%) with MnCO₃(A.R.), and further weighing H accounting for 5w percent of the total mass of the raw materials₃BO₃As a flux.

(2) Grinding the raw materials weighed in the step (1) for 30 minutes and uniformly mixing to obtain a mixture; loading the mixture into a crucible, pushing the crucible into a tubeIn the high temperature furnace, a mixed gas of nitrogen and hydrogen (95% N) was introduced₂+5％H₂Volume percent), temperature programming, heating to 1300 ℃ at an average heating rate of 5 ℃/min, roasting for 4 hours at 1300 ℃, stopping heating, continuing introducing nitrogen gas for cooling to room temperature, taking out, and slightly grinding to obtain the target fluorescent powder Rb_1.2Al_10.7O_17.15:0.2Eu²⁺,0.3Mn²⁺。

Example 8: preparation of Na_1.2Al_6.7Ga₄O_17.15:0.2Eu²⁺,0.3Mn²⁺

The preparation method specifically comprises the following steps:

(1) weighing Na according to stoichiometric ratio₂CO₃(A.R.)、Al(OH)₃(A.R.)、Ga₂O₃(A.R.)、Eu₂O₃(99.99%) with MnCO₃(A.R.), and further weighing H accounting for 5w percent of the total mass of the raw materials₃BO₃As a flux.

(2) Grinding the raw materials weighed in the step (1) for 30 minutes and uniformly mixing to obtain a mixture; the mixture was charged into a crucible, the crucible was pushed into a tube-type high-temperature furnace, and a mixed gas of nitrogen and hydrogen (95% N) was introduced₂+5％H₂Volume percent), temperature programming, heating to 1300 ℃ at an average heating rate of 5 ℃/min, roasting for 4 hours at 1300 ℃, stopping heating, continuing introducing nitrogen gas for cooling to room temperature, taking out, and slightly grinding to obtain the target fluorescent powder Na_1.2Al_6.7Ga₄O_17.15:0.2Eu²⁺,0.3Mn²⁺。

Example 9:

the fluorescent powder K containing blue light and green light emission bands_1.6Al_10.98O_17.49:0.2Eu²⁺,0.02Mn²⁺With narrow-band red phosphor K₂SiF₆:Mn⁴⁺Mixing at a mass ratio of 10:1, mixing with silica gel for packaging at a powder-to-gel ratio of 2:5, dripping the obtained mixture around 365nm near-ultraviolet LED chip and covering the chip and wires, and curing at 120 deg.C in a vacuum drying oven to obtain white LEDThe electroluminescence spectrum of the light LED device and the white light LED device is shown in figure 10, and three emission bands of blue, green and red can be obviously observed. In the electroluminescence spectrum of the LED, the triangular regions surrounded by the color coordinates corresponding to the blue, green and red emission bands are shown in fig. 10, and the theoretical color gamut is 106.3% of the National Television Standards Committee (NTSC) standard.

Example 10:

green light phosphor K of the invention_1.6Al_10.82O_17.41:0.2Eu²⁺,0.18Mn²⁺Blue light fluorescent powder K_1.6Al₁₁O_17.5:0.2Eu²⁺And narrow-band red-light phosphor K₂SiF₆:Mn⁴⁺And mixing the materials according to the mass ratio of 2:5:1, uniformly mixing the materials with silica gel for packaging, wherein the powder-to-gel ratio is 2:5, dripping the obtained mixed material to the periphery of a 365nm near ultraviolet LED chip, covering the chip and a lead, and then placing the chip and the lead in a vacuum drying oven for curing at 120 ℃ to obtain the white light LED device. The electroluminescence spectrum of the white LED device is shown in fig. 11, and blue, green, and red emission bands from 3 kinds of phosphors can be observed.

With respect to the blue phosphors K of examples 6 and 7_1.6Al₁₁O_17.5:0.2Eu²⁺The preparation method comprises the following steps:

(1) weighing K according to the stoichiometric ratio of elements₂CO₃(A.R.)、Al(OH)₃(A.R.)、Eu₂O₃(99.99%) and further weighing H in an amount of 5 w% based on the total mass of the raw materials₃BO₃As a fluxing agent;

(2) grinding the raw materials for 30 minutes, and uniformly mixing to obtain a mixture; the mixture was charged into a crucible and pushed into a tube-type high-temperature furnace, and a mixed gas of nitrogen and hydrogen (95% N) was introduced₂+5％H₂Volume percent) is adopted, the temperature is controlled by program, the temperature is increased to 1400 ℃ at the average heating rate of 5 ℃/min, the mixture is roasted for 4 hours at 1400 ℃, the mixture is naturally cooled to the room temperature, and the mixture is taken out and slightly ground to obtain the blue-light fluorescent powder K_1.6Al₁₁O_17.5:0.20Eu²⁺。

Claims (10)

1. Eu (Eu)²⁺-Mn²⁺The codoped fluorescent powder is characterized in that the chemical general formula of the fluorescent powder is A_aM_11-zO_17+b:yEu^{2 +},zMn²⁺Wherein A is any one or combination of more of Li, Na, K and Rb, M is any one or combination of two of Al and Ga, and y is more than or equal to 0.01 and less than or equal to 0.3, and 0<z≤1，1≤a≤2，0≤b≤1。

2. Eu according to claim 1²⁺-Mn²⁺The codoped fluorescent powder is characterized in that the chemical general formula of the fluorescent powder is (Na)_1-xK_x)_aAl_11-zO_17+b:yEu²⁺,zMn²⁺Wherein x is more than or equal to 0 and less than or equal to 1.

3. Eu according to claim 1 or 2²⁺-Mn²⁺The codoped phosphor is characterized in that the matrix lattice of the phosphor is a hexagonal phase, and the space group is P6₃/mmc。

4. Eu according to claim 1 or 2²⁺-Mn²⁺The co-doped fluorescent powder is characterized in that when z is more than or equal to 0.14, the fluorescent powder emits green fluorescence mainly with an emission band of 480-550nm under the excitation of ultraviolet light with the wavelength of 250-420nm, the emission band is a green light emission band with the peak value positioned at 505-515nm, and the emission half-peak width is 20-30 nm;

when the z is more than 0 and less than 0.14, the fluorescent powder emits 400-550nm blue-green fluorescence under the excitation of ultraviolet light with the wavelength of 250-420nm, and comprises two emission bands, wherein one emission band is a blue light emission band with the peak value at 440-480nm and the half-peak width is 50-75nm, the other emission band is a green light emission band with the peak value at 505-515nm and the emission half-peak width is 20-30 nm.

5. Eu according to any one of claims 1 to 4²⁺-Mn²⁺Preparation method of co-doped fluorescent powderCharacterized by comprising the following steps:

(1) according to the general formula A_aM_11-zO_17+b:yEu²⁺,zMn²⁺Respectively weighing a compound containing A, a compound containing M, a compound containing europium, a compound containing manganese and a fluxing agent accounting for 3-7% of the total mass of the raw materials;

(2) grinding and uniformly mixing the raw materials weighed in the step (1) to obtain a mixture; heating the mixture to 1100-1600 ℃ in a reducing atmosphere, roasting for 3-5h, cooling to room temperature, and grinding to obtain the Eu²⁺-Mn²⁺And co-doping the fluorescent powder.

6. The method according to claim 5, wherein in the step (1), the A-containing compound is any one or a combination of carbonate, bicarbonate and oxalate of A, the M-containing compound is any one or a combination of hydroxide and oxide of M, and the europium-containing compound is Eu₂O₃、EuCl₃、Eu(NO₃)₃The manganese-containing compound is MnCO₃、MnO₂Any one or the combination of two, the fluxing agent is H₃BO₃、CaF₂、SrF₂、BaF₂、(NH₄)₂CO₃Any one or a combination of several of them.

7. The method as claimed in claim 5 or 6, wherein in the step (2), the temperature is raised to 1100-1600 ℃ at an average temperature raising rate of 4-6.5 ℃/min.

8. The production method according to claim 5 or 6, wherein in the step (2), the reducing atmosphere is H₂And N₂The mixed gas of (1), said H₂And N₂The volume ratio of (A) to (B) is 5:95-10: 90.

9. A process as claimed in any one of claims 1 to 4Eu (E)²⁺-Mn²⁺Codoped phosphor or Eu prepared by the preparation method of any one of claims 5 to 8²⁺-Mn²⁺The application of the co-doped fluorescent powder is characterized in that the fluorescent powder is applied to the manufacture of a white light LED device.

10. Use according to claim 9, wherein the Eu is used when z ≧ 0.14²⁺-Mn²⁺Mixing the codoped fluorescent powder with blue fluorescent powder and red fluorescent powder, and packaging the mixture on a near ultraviolet LED chip to manufacture a white light LED device;

when 0 is present<z<0.14 hr, adding the Eu²⁺-Mn²⁺And mixing the co-doped fluorescent powder and the red fluorescent powder, and packaging the mixture on a near ultraviolet LED chip to manufacture a white light LED device.

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