CN110862822A

CN110862822A - Molybdate-based red fluorescent powder and preparation method and application thereof

Info

Publication number: CN110862822A
Application number: CN201911238552.5A
Authority: CN
Inventors: 邱克辉; 周鹏; 乐露
Original assignee: Chengdu Univeristy of Technology
Current assignee: Chengdu Univeristy of Technology
Priority date: 2019-12-06
Filing date: 2019-12-06
Publication date: 2020-03-06

Abstract

The invention relates to molybdate-based red fluorescent powder and a preparation method and application thereof, belonging to the technical field of rare earth functional materials. The invention relates to a rare earth luminescent material with luminescent property, which has the chemical formula as follows: LiLa (MoO)₄)₂:xSm³⁺,yAg⁺(ii) a Wherein x is more than or equal to 1% and less than or equal to 9%, and y is more than or equal to 0.5% and less than or equal to 6%. The molybdate-based red fluorescent powder prepared by the invention has excellent luminescence property, and Sm is used³⁺、Ag⁺The two ions are doped together, so that the product becomes red fluorescent powder for a white light LED, and the luminous performance is obviously enhanced.

Description

Molybdate-based red fluorescent powder and preparation method and application thereof

Technical Field

The invention relates to molybdate-based red fluorescent powder and a preparation method and application thereof, belonging to the technical field of rare earth functional materials.

Background

The rare earth luminescent material generally uses a host compound as a matrix, and rare earth ions used as luminescent centers are doped in a small amount as an activator. Some other impurity ions or rare earth ions can serve as a sensitizer and transfer absorbed energy to an activator, so that the luminescent performance is improved. Most of the rare earth ion 4f shell layers are in an unfilled state, and 4f electrons of the rare earth ion are transited in a configuration or between the configurations after being excited by ultraviolet light and near ultraviolet light so as to release light with different colors. In addition, the rare earth ions are various, and other novel luminescent materials can be synthesized by different rare earth ion combinations. The compound is used as a main body, and a small amount of rare earth doped rare earth luminescent material can be used as fluorescent powder for an LED, and has excellent thermal stability, chemical stability and high temperature resistance.

Since the 21 st century, energy shortage and environmental protection have become outstanding problems in human society, and researchers are continuously searching and exploring new energy and changing the energy structure to find a new renewable energy source in order to meet the real demand for energy, and the related field involves the development of new energy-saving materials and equipment. White light LEDs are currently used in a wide variety of applications, including lighting, displays, storage devices, and medical devices, as a green, environmentally friendly illumination source. The white light LED has the advantages of long service life, low energy consumption, no pollution, high reliability and the like. At present, there are two main approaches to realize white light: (1) the yellow light emitted by the yellow fluorescent powder (YAG: Ce) coated on the blue light chip is compounded with the blue light emitted by the chip to form white light. (2) The three independent primary color fluorescent powders emit red, green and blue light under the irradiation of the ultraviolet chip to form white light. However, the two methods generally have the defects of insufficient intensity in a red light region and excessive blue light. Since the high-quality red phosphor can effectively solve the above problems, it is necessary to develop a novel red phosphor.

Rare earth ion doped dimolybdate (ALn (MoO)₄)₂) The red phosphor is of great interest because of its good physicochemical stability, optical properties, and ferroelectric properties. Rare earth doped LiLa (MoO)₄)₂Is a high-quality fluorescent powder, has strong absorption in a near ultraviolet region, and contains MoO in a matrix₄ ^2-The group has a stronger charge migration zone in an ultraviolet light region, and absorbed energy can be effectively transferred to a rare earth luminescence center, so that the rare earth activated ultraviolet excited fluorescent material becomes an ideal rare earth activated ultraviolet excited fluorescent material. In addition, the research adopts a citric acid solution combustion method, and compared with the traditional high-temperature solid phase method, the process has the advantages of simplicity and convenience in operation, simple process flow, low cost and the like.

At present, related researches on rare earth luminescent materials of rare earth ion doped dimolybdate have been carried out, and related patents also appear on the aspect of luminescence of molybdate.

The application number is ' 201910516339.X ', the name of the invention is ' high-temperature luminous enhanced rare earthA lutetium earth base molybdate material and a preparation method thereof, which discloses a material with the chemical formula as follows: lu (Lu)_2-xEu_x(MoO₄)₃The fluorescent powder is prepared by a solid-phase method. The invention aims to prepare the lutetium-based molybdate red fluorescent powder which can be excited by ultraviolet light, near ultraviolet light and blue light, and the phenomenon that the material has enhanced luminescence along with the rise of temperature is observed, so that the material has good thermal stability and embodies excellent luminescence performance. However, no corresponding report is made on the luminescence property of the lithium lanthanum molybdate.

The application number is '201711431781. X', the invention name is 'double-doped molybdate luminescent material with red light emitting and a preparation method and application thereof', and the invention discloses a luminescent material with the chemical formula as follows: li₂Eu_4#x(MoO₄)₇:xBi³⁺Wherein, 0<x is less than or equal to 0.4 and is a rare earth luminescent material with red light. The fluorescent powder has stable performance, high luminous intensity and high color purity. The double-doped molybdate luminescent material obtained in the patent can be used for red fluorescent powder for white light LEDs excited by ultraviolet and blue light chips. But for the metal ion Ag⁺And rare earth ion Sm³⁺The co-doped lanthanum lithium molybdate rare earth luminescent material with luminescent property has not been reported correspondingly.

The application number is '201810859162.9', the invention name is 'scheelite type molybdate red fluorescent powder for white light LED and a preparation method thereof', and a chemical formula is disclosed as follows: BaBi_2(1#x)Eu_2x(MoO₄)₄Has a red-emitting rare earth luminescent material. The fluorescent powder is of a monoclinic phase scheelite structure, has low symmetry, and thus has high luminous intensity. Characterized in that the synthesis temperature is as low as 750 ℃, the cost is low, and the method is very beneficial to industrial production. The chromaticity coordinates are very close to the standard red chromaticity coordinates (0.67,0.33) with a color purity as high as 98%. However, the rare earth luminescent material with luminescent property of the lithium lanthanum molybdate obtained by adopting a citric acid solution combustion method under the condition of keeping the synthesis temperature at 700 ℃ for 1h is not reported correspondingly.

Disclosure of Invention

The first technical problem to be solved by the invention is to provide a luminescent material with better luminescent propertyA rare earth luminescent material. Sm is adopted in the invention³⁺Doping with LiLa (MoO)₄)₂Partially substituted La³⁺，Ag⁺Doping with LiLa (MoO)₄)₂Partially substituted Li⁺The molybdate-based red rare earth fluorescent powder with excellent luminescence property is obtained in the mode.

The rare earth luminescent material with luminescent property has the chemical formula: LiLa (MoO)₄)₂:xSm³⁺,yAg⁺(ii) a Wherein x is more than or equal to 1% and less than or equal to 9%, and y is more than or equal to 0.5% and less than or equal to 6%.

Preferably: x is 1-7%, y is 0.5-6%; more preferably: x is 1-7%, and y is 0.5-4%.

More preferably: x is 3-7%, and y is 0.5-2%.

After the test, the rare earth luminescent material with the best luminescent property is obtained by the following steps: LiLa (MoO)₄)₂:xSm³⁺,yAg⁺(ii) a Wherein, x is 5%, and y is 1%.

The second technical problem to be solved by the invention is to provide a preparation method of a rare earth luminescent material with luminescent property, which is a citric acid solution combustion method.

The preparation method of the rare earth luminescent material with luminescent property comprises the following steps: the method comprises the following steps:

a. preparing raw materials: by LiLa (MoO)₄)₂:xSm³⁺,yAg⁺Taking Li as the stoichiometric ratio of each element₂CO₃(99.0％),La₂O₃(99.9％),AgNO₃(99.0％),(NH₄)₆Mo₇O₂₄·4H₂O(99.0％),C₆H₈O₇(99.8％),Sm₂O₃(99.99%); wherein x is more than or equal to 1% and less than or equal to 9%, and y is more than or equal to 0.5% and less than or equal to 6%. (ii) a

b. Taking (NH) obtained in step a₄)₆Mo₇O₂₄·4H₂Adding distilled water to O to prepare (NH)₄)₆Mo₇O₂₄Solution for later use; taking Sm obtained in the step a₂O₃、La₂O₃、Li₂CO₃Adding dilute nitric acid to prepare Sm (NO)₃)₃、La(NO₃)₃、LiNO₃Solution for later use; the AgNO obtained in the step a₃Adding into distilled water to prepare AgNO₃Solution for later use;

c. the AgNO prepared in the step b₃Adding the solution into prepared Sm (NO)₃)₃、La(NO₃)₃、LiNO₃Heating the solution to 70-90 ℃, and uniformly mixing until the solution is clear;

d. adding citric acid into the nitrate solution prepared in the step c, heating to 70-90 ℃, and uniformly mixing until the solution is clear; wherein the citric acid is mixed with LiLa (MoO)₄)₂The molar ratio of the medium metal cations is 1.5: 1;

e. the (NH) prepared in the step b₄)₆Mo₇O₂₄Adding the solution into the clear solution prepared in the step d, and heating and reacting at 60-80 ℃ for 0.5-1.5 h to obtain a light yellow transparent gelatinous precursor;

f. and e, roasting the precursor prepared in the step e at 500-800 ℃ for 0.5-3 h to obtain the product.

Preferably, in step c: heating to 70 ℃.

Preferably, in step e: the heating temperature is 70 ℃, and the reaction time is 1 h.

Preferably, in step f: the calcining temperature is 700 ℃, and the calcining time is 1 h.

The invention has the beneficial effects that:

1. the invention creatively uses Sm³⁺、Ag⁺Two metal ions are co-doped to successfully react with LiLa (MoO)₄)₂The La position and the Li position in the matrix are partially substituted, and no mixed phase is generated;

2. sm is³⁺、Ag⁺The co-doping of two metal ions improves the doping with LiLa (MoO)₄)₂Luminous intensity of rare earth phosphor of substrate, pair Sm³⁺、Ag⁺The occupation, the luminescence mechanism and the concentration quenching of two metal ions in a matrix are researched in detail;

3. the rare earth luminescent material with the luminescent property releases orange red light under the excitation of near ultraviolet light, so that the fluorescent powder becomes red fluorescent powder for a white light LED;

4. the citric acid solution combustion method is adopted, so that the synthesis temperature is low, the preparation process is simple and convenient, the energy consumption is low, and the synthesis cost is low;

5. the product of the invention has the advantages of no toxicity, no pollution and high physical and chemical stability, releases stronger orange red light under the excitation of near ultraviolet light, and realizes that the LED device still has the luminous capability in severe environment. The ion doping LiLa (MoO) is greatly widened₄)₂The application field of the multifunctional material.

Drawings

FIG. 1 shows LiLa (MoO)₄)₂:xSm³⁺,yAg⁺XRD pattern of (a).

FIG. 2 shows LiLa (MoO)₄)₂SEM image of (d).

FIG. 3 shows LiLa (MoO)₄)₂:xSm³⁺Excitation and emission spectra of the phosphors (x ═ 1%, 5%).

FIG. 4 shows LiLa (MoO)₄)₂:xSm³⁺(x ═ 1% to 9%) of the emission spectrum.

FIG. 5 shows LiLa (MoO)₄)₂:0.05Sm³⁺,yAg⁺(y 0%, 1%) excitation spectrum of the phosphor.

FIG. 6 shows LiLa (MoO)₄)₂:0.05Sm³⁺,yAg⁺(y ═ 0.5% to 6%) emission spectrum of the phosphor.

FIG. 7 shows LiLa (MoO)₄)₂:0.05Sm³⁺,yAg⁺(y 0%, 1%) of the phosphor.

FIG. 8 shows LiLa (MoO)₄)₂:0.05Sm³⁺,yAg⁺(y ═ 0.5% -6%) color coordinate plot of phosphor.

Detailed Description

The first technical problem to be solved by the invention is to provide a rare earth luminescent material with better luminescent property. Sm is adopted in the invention³⁺Doping with LiLa (MoO₄)₂Partially substituted La³⁺，Ag⁺Doping with LiLa (MoO)₄)₂Partially substituted Li⁺The molybdate-based red rare earth fluorescent powder with excellent luminescence property is obtained in the mode.

The rare earth luminescent material with luminescent property has the chemical formula: LiLa (MoO)₄)₂:xSm³⁺,yAg⁺(ii) a Wherein x is more than or equal to 1% and less than or equal to 9%, and y is more than or equal to 0.5% and less than or equal to 6%. The x and y of the invention are required to be within the above-mentioned limits, when x is more than or equal to 1% and less than or equal to 9%, the x is added with Sm³⁺The light emission intensity gradually increases with increasing doping concentration, and reaches a maximum when x is 5%. When x is>At 5%, the luminescence intensity decreases, due to the doping ion concentration being too high, the distance between adjacent luminescence centers being less than the critical quenching distance, the probability of cross relaxation increases such that the absorbed energy is consumed in the form of non-radiative transitions, resulting in a decrease in luminescence intensity. When Sm is³⁺,Ag⁺When co-doped, a small amount of Ag⁺Partially substituted Li⁺Sm to alter the symmetry of the crystal field around the luminescent center and reduce the symmetry of the lattice to affect the energy level transition³⁺The odd-even selection rule of the transition is released, so that the luminous intensity is enhanced. When y is>1% of Ag, the luminous intensity gradually decreases, and the concentration of Ag is high⁺The crystal defects increase and the luminous intensity is reduced.

The rare earth luminescent material LiLa (MoO) with luminescent property prepared by the invention₄)₂:xSm³⁺,yAg⁺On the one hand, the equivalent ion Sm³⁺Partially substitute La³⁺Under the excitation of near ultraviolet light, the energy absorbed by the matrix is transferred to a luminescence center, so that the material has good luminescence performance; on the other hand, Ag⁺Partial substitution of LiLa (MoO)₄)₂Li in (1)⁺The symmetry of the crystal field around the luminescence center is changed, the symmetry is reduced, and the luminescence performance is further improved.

In order to improve the luminescence properties of the product, it is preferred that: x is 1-7%, y is 0.5-6%; more preferably: x is 1-7%, and y is 0.5-4%. More preferably: x is 3-7%, and y is 0.5-2%.

After the experiment, when x is 5% and y is 1%, the luminescence performance of the product is optimal under the mixture ratio.

The second technical problem to be solved by the invention is to provide a preparation method of a molybdate-based luminescent material with luminescent property, wherein the method is a citric acid solution combustion method.

c. the AgNO prepared in the step b₃Adding the solution into prepared Sm (NO)₃)₃、La(NO₃)₃、LiNO₃And heating the solution to 70-90 ℃, and uniformly mixing until the solution is clear.

In the step b, the adopted nitric acid is dilute nitric acid, and the concentration is 5-40%; dissolving (NH)₄)₆Mo₇O₂₄·4H₂O、Sm₂O₃、La₂O₃And Li₂CO₃Proper amount of required distilled water and nitric acid;

preferably, AgNO is formulated₃In solution, AgNO₃The mass ratio of the water to the water is 0.0034-0.0408 g:5 mL; more preferably, AgNO₃The mass ratio of the (B) to the water is 0.0068g:5 mL;

preferably, Sm (NO) is formulated₃)₃When in solution, Sm₂O₃The mass of the diluted nitric acid is 0.0070-0.0628 g:1.5 mL; more preferably, Sm₂O₃The volume of the dilute nitric acid is 0.0349g and 1.5 mL;

to accelerate Sm₂O₃、AgNO₃The dissolution rate of (A) is such that Sm is dissolved in the solvent₂O₃Adding dilute nitric acid, and stirring in a 70 deg.C magnetic stirrer to obtain Sm (NO)₃)₃A solution; AgNO₃Adding distilled water, and stirring and mixing on a 70 ℃ magnetic stirrer to obtain AgNO₃And (3) solution.

Preferably, formulation (NH)₄)₆Mo₇O₂₄Solution, (NH)₄)₆Mo₇O₂₄The mass-to-volume ratio of the distilled water to the distilled water is 1-2 g:10 mL; more preferably, (NH)₄)₆Mo₇O₂₄The mass-to-volume ratio of the water to distilled water was 1.4124g:10 mL.

The synthesis temperature of the step f of the invention needs to be within the range of 500-800 ℃, and when the temperature is lower than 700 ℃, the energy obtained by the crystal grains is lower and the development is incomplete. Influence the luminescence property of the sample; when the temperature is over 700 ℃, the particles grow excessively and are sintered obviously, so that the luminous performance is influenced.

Preferably, in step c: heating to 70 ℃.

The product of the invention has the performance of red fluorescent powder, so the product can be used as illumination, displays, storage devices, medical appliances and the like. In addition, the product of the invention has the advantages of excellent physical and chemical stability, thermal stability and the like. The product of the invention is a nontoxic and pollution-free environment-friendly material, and can release strong orange red light under the excitation of near ultraviolet light, thereby realizing that the LED device still has the luminous capability in severe environment. The ion doping LiLa (MoO) is greatly widened₄)₂The application field of the multifunctional material.

The invention has the beneficial effects that:

5. the product of the invention has the advantages of no toxicity, no pollution, high physical and chemical stability and near ultraviolet excitationStronger orange and red light is released, so that the LED device still has the luminous capability in a severe environment. The ion doping LiLa (MoO) is greatly widened₄)₂The application field of the multifunctional material.

The fluorescence characteristic detection method of the rare earth luminescent material comprises the following steps:

1. taking the LiLa (MoO) with the luminescent property prepared by the invention₄)₂:xSm³⁺,yAg⁺And a proper amount of fluorescent powder is placed in a fluorescence spectrometer, and the excitation spectrum of the sample is measured at the monitoring wavelength of 648 nm. Measurement of Sm³⁺/Ag⁺Influence on the excitation spectrum of the sample under different doping concentrations. In order to eliminate the error of experimental instrument to the experimental result, the experiment adopts a constant temperature magnetic stirrer for stirring, and the temperature is 70 ℃. Samples with different doping concentrations are calcined in a muffle furnace at one time by using corundum crucibles with the same size. And (3) calcining at 700 ℃, keeping the temperature for 1h, and finally taking out and air-cooling to room temperature to obtain the fluorescent powder sample. Taking a proper amount of LiLa (MoO)₄)₂:xSm³⁺,yAg⁺The strongest absorption wavelength (403nm) was measured by the phosphor.

2. Taking the LiLa (MoO) with the luminescent property prepared by the invention₄)₂:xSm³⁺,yAg⁺And a proper amount of fluorescent powder is placed in a fluorescence spectrometer, and the emission spectrum of the sample is measured under the excitation wavelength of 403 nm. Measurement of Sm³⁺/Ag⁺Influence on the emission spectrum of the sample under different doping concentrations. In order to eliminate the error of experimental instrument to the experimental result, the experiment adopts a constant temperature magnetic stirrer for stirring, and the temperature is 70 ℃. Samples with different doping concentrations are calcined in a muffle furnace at one time by using corundum crucibles with the same size. And (3) calcining at 700 ℃, keeping the temperature for 1h, and finally taking out and air-cooling to room temperature to obtain the fluorescent powder sample. Taking a proper amount of LiLa (MoO)₄)₂:xSm³⁺,yAg⁺The strongest emission peak (648nm) was detected by the phosphor.

The following examples further describe embodiments of the present invention.

Example 1

Weighing 1.4124g (NH)₄)₆Mo₇O₂₄·4H₂O was made up by adding 10mL of distilled water (NH)₄)₆Mo₇O₂₄Heating and stirring the solution to 70 ℃ for later use; weighing Li₂CO₃，La₂O₃，Sm₂O₃Adding 1.5mL of 40% dilute nitric acid to prepare a nitrate solution, heating and stirring to 77 ℃ for later use; 2.304g of anhydrous citric acid is weighed and added into the stirred nitrate solution, and the mixture is continuously heated and stirred until the solution is clear; to be prepared of (NH)₄)₆Mo₇O₂₄Adding the solution into the prepared clear solution, heating and stirring at 70 ℃ for 1h to obtain a light yellow transparent gelatinous precursor; roasting the precursor in a muffle furnace at 700 ℃ for 1h to obtain LiLa_1-x(MoO₄)₂:xSm³⁺And (3) fluorescent powder.

Sm₂O₃And La₂O₃The corresponding amount changes are shown in table 1.

TABLE 1

LiLa(MoO₄)₂:xSm³⁺	x＝1％	x＝3％	x＝5％	x＝7％	x＝9％
						Sm₂O₃(g)	0.0070	0.0209	0.0349	0.0488	0.0628
La₂O₃(g)	0.6451	0.6321	0.6190	0.6060	0.5930

Example 2

On the basis of example 1, Li was changed₂CO₃、AgNO₃In an amount to obtain LiLa (MoO)₄)₂:0.05Sm³⁺，yAg⁺And (3) fluorescent powder. The chemical formula of the obtained product is as follows: LiLa (MoO)₄)₂:0.05Sm³⁺，yAg⁺(y＝0.5％-6％)。AgNO₃And Li₂CO₃The corresponding amount changes are shown in table 2.

TABLE 2

Test example 1

1. Testing of LiLa (MoO)₄)₂:xSm³⁺,yAg⁺The XRD patterns and SEM patterns of fig. 1 and 2. From FIG. 1, it can be seen that: LiLa (MoO)₄)₂:Sm³⁺XRD results of (A) with standard LiLa (MoO)₄)₂The diffraction peaks of the results are consistent, the purity of the sample is high, and other impurity peaks do not appear. LiLa (MoO)₄)₂:Sm³⁺,Ag⁺With standard LiLa (MoO)₄)₂The diffraction peaks of the results are consistent, the purity of the sample is high, and other impurity peaks do not appear. FIG. 2 shows that the particle size and the distribution are uniform after the heat preservation at 700 ℃ for 1hThe sample of (1).

2. With the resulting sample LiLa (MoO)₄)₂:xSm³⁺The fluorescent powder is used as a test sample, and an excitation spectrum and an emission spectrum of the fluorescent powder are measured under the irradiation of near ultraviolet light with a monitoring wavelength of 648nm and an excitation wavelength of 403nm under the measurement of a fluorescence spectrophotometer. It is formed by singly doping Sm³⁺Excitation and emission spectra contrast plot (FIG. 3) at concentrations of 1% and 5%, respectively, and Sm mono-doping³⁺The emission spectrum of the phosphor at a concentration of (x ═ 1% to 9%) (fig. 4).

3. With the resulting sample LiLa (MoO)₄)₂:0.05Sm³⁺,yAg⁺(y is 0.5-6%) of the fluorescent powder is used as a test sample, and the excitation spectrum and the emission spectrum of the fluorescent powder are measured under the irradiation of near ultraviolet light with the monitoring wavelength of 648nm and the excitation wavelength of 403nm under the measurement of a fluorescence spectrophotometer. In which Ag is co-doped⁺Comparison of excitation spectra at concentrations of 0% and 1%, respectively (FIG. 5) and co-doped Ag⁺The emission spectrum of the phosphor at the concentration of (y ═ 0.5% to 6%) (fig. 6).

4. Testing of LiLa (MoO)₄)₂:0.05Sm³⁺,yAg⁺FIG. 7 shows the fluorescence lifetime spectrum of (A). As can be seen from fig. 7: LiLa (MoO) was measured under a test of a monitoring wavelength of 648nm and an excitation wavelength of 403nm₄)₂:0.05Sm³⁺,yAg⁺(y 0%, 1%) fluorescent lifetime of the phosphor, Ag⁺The fluorescence lifetimes before and after ion doping were 567. mu.s and 569. mu.s, respectively, and can be calculated from the following equation.

5. Testing of LiLa (MoO)₄)₂:0.05Sm³⁺,yAg⁺As shown in fig. 8. As can be seen from fig. 8: LiLa (MoO) was measured under a test of a monitoring wavelength of 648nm and an excitation wavelength of 403nm₄)₂:0.05Sm³⁺,yAg⁺(y ═ 0.5% to 6%) color coordinates of the phosphors. LiLa (MoO) is shown in Table 3 and FIG. 8₄)₂:0.05Sm³⁺，yAg⁺Color coordinates and chromaticity diagram of the phosphor. All samples emitted orange-red light.

TABLE 3

LiLa(MoO₄)₂:0.05Sm³⁺,yAg⁺	Ag⁺(mol％)	Abscissa of the circle	Ordinate of the curve
				1	0.005	0.6207	0.3966
2	0.01	0.6033	0.3960
				3	0.02	0.6051	0.3943
4	0.04	0.6057	0.3936
				5	0.06	0.6057	0.3937

From the above table the following conclusions can be drawn:

1. LiLa (MoO) synthesized by citric acid solution combustion method and kept at 700 ℃ for 1h₄)₂:Sm³⁺,Ag⁺And (4) red fluorescent powder. X-ray diffraction analysis shows that LiLa (MoO) with high purity and good crystallinity can be obtained under the condition of heat preservation at 700 ℃ for 1h₄)₂:Sm³⁺,Ag⁺And (3) sampling.

2. Change rare earth ion Sm³⁺And metal ion Ag⁺The doping concentration of the material shows that the sample can be effectively excited by near ultraviolet light, and the excitation spectrum is formed by 200-330 nm Mo⁶⁺–O^2-Charge transport zone and source Sm in the range of 330-550 nm³⁺And sharp excitation peaks generated by the f-f energy level transition. LiLa (MoO)₄)₂:Sm³⁺,Ag⁺The emission spectrum of (B) is Sm with the wavelength of 550-700 nm³ ⁺With the strongest emission peak near 648nm corresponding to Sm³⁺Is/are as follows⁴G_5/2→⁶H_9/2Electric dipole transition of (2). Ag⁺After entering into crystal lattice, the crystal field symmetry of the environment near the luminescence center is changed, when Ag⁺When the doping concentration reaches 1 mol%, LiLa (MoO)₄)₂:Sm³⁺,Ag⁺The luminous intensity of the fluorescent powder reaches the maximum value.

3.Ag⁺Codoping into LiLa (MoO)₄)₂:Sm³⁺The fluorescent powder has no great change to the fluorescent life and color coordinate, which shows that LiLa (MoO)₄)₂:Sm³⁺,Ag⁺The fluorescent powder has better color stability.

Claims

1. Rare earth with luminescent propertyA luminescent material having the formula: LiLa (MoO)₄)₂:xSm³⁺,yAg⁺(ii) a Wherein x is more than or equal to 1% and less than or equal to 9%, and y is more than or equal to 0.5% and less than or equal to 6%.

2. The rare earth luminescent material having a luminescent property as claimed in claim 1, characterized in that: x is more than or equal to 1 percent and less than or equal to 9 percent.

3. The rare earth luminescent material having a luminescent property as claimed in claim 2, characterized in that: y is more than or equal to 0.5 percent and less than or equal to 6 percent.

4. The rare earth luminescent material having a luminescent property as claimed in claim 1, characterized in that: x is more than or equal to 1 percent and less than or equal to 9 percent, and y is more than or equal to 0.5 percent and less than or equal to 6 percent.

5. The rare earth luminescent material having a luminescent property as claimed in claim 4, characterized in that: x is 5% and y is 1%.

6. The method for producing a rare earth luminescent material having a luminescent property as claimed in any one of claims 1 to 5, characterized in that: the method comprises the following steps:

f. and e, roasting the precursor prepared in the step e at 700 ℃ for 1h to obtain the product.

7. The method for preparing a rare earth luminescent material having a luminescent property according to claim 6, wherein in step c: heating to 70 deg.C; in the step e: the heating temperature is 70 ℃, and the reaction time is 1 h.

8. The method for producing a rare earth luminescent material having a luminescent property according to claim 6, wherein in step f: the calcining temperature is 700 ℃, and the calcining time is 1 h.

9. The use of the rare earth luminescent material having a luminescent property as claimed in any one of claims 1 to 5, wherein the rare earth luminescent material having a luminescent property is used in the field of LED lighting.

10. Use of a rare earth luminescent material having a luminescent property according to claim 9, characterized in that: the rare earth doped ion is Sm³⁺The metal cation is Ag⁺。