CN107814484B

CN107814484B - Europium ion self-reduction-capability-containing luminescent transparent glass and preparation method thereof

Info

Publication number: CN107814484B
Application number: CN201711138104.9A
Authority: CN
Inventors: 赖杨丽; 孙利利; 余丽萍; 王官华
Original assignee: Hunan Normal University
Current assignee: Hunan Normal University
Priority date: 2017-11-16
Filing date: 2017-11-16
Publication date: 2020-03-31
Anticipated expiration: 2037-11-16
Also published as: CN107814484A

Abstract

Luminescent glass containing europium ion self-reduction capability and a preparation method thereof, belonging to the technical field of rare earth luminescent materials. The method adopts BaZnSiO₄The glass matrix is used for reducing trivalent europium by a high-temperature melting method in an air atmosphere and comprises the following raw materials in parts by weight: BaCO₃57.92 parts, ZnO 23.91 parts, SiO₂17.65 parts, Eu₂O₃0.52-2.6 parts of melting agent, 10-15 parts of crystal nucleus agent and 1.18 parts of glass clarifying agent. Compared with other reduction methods, the method does not need special protective atmosphere, has low equipment requirement, simple operation and obvious reduction effect, reduces the investment of raw materials and equipment, and is green and environment-friendly. The Eu appears in the prepared luminescent glass under the excitation of 285nm-350nm ultraviolet light³⁺Characteristic emission wavelength (612 nm) and Eu²⁺Characteristic emission band (380 nm-470 nm) and the longer the excitation wavelength, the Eu³⁺The weaker the emitted light intensity is, the Eu²⁺The stronger the emission light intensity is, the better the relative reduction effect is, the CIE coordinates are displayed, the emission light of the product obtained by excitation of different excitation wavelengths can be regulated from magenta to blue, the product stability is good, and the product can be used as a luminescent material.

Description

Europium ion self-reduction-capability-containing luminescent transparent glass and preparation method thereof

Technical Field

The invention relates to europium ion self-reducing luminous transparent glass and a preparation method thereof, belonging to the field of rare earth luminescent materials.

Background

So far, white light emitting diodes (i.e., LEDs) are increasingly widely used in life, and have the advantages of high brightness, less energy consumption, compact structure, high sensitivity, environmental protection, etc. compared with conventional incandescent lamps and fluorescent lamps.

The current commercial white light LED is formed by combining a blue light LED chip and yellow fluorescent powder. There is also a method of uniformly mixing blue, green and red phosphors excited by ultraviolet light to emit three primary colors in a certain ratio to mix light and output white light, in which Eu is used as a phosphor material²⁺The ion-doped fluorescent powder is an important blue fluorescent material. Existing phosphor coatingThe LED-coated chip has the technical defects of poor color rendering property, complex packaging process, easy aging of epoxy resin for packaging and the like, and compared with glass, the glass has good chemical stability, the rare earth doped luminescent glass is used for replacing fluorescent powder, so that the light decay phenomenon of the fluorescent powder can be greatly reduced, and the light efficiency and the service life of the white LED are improved.

Disclosure of Invention

Based on this, the present invention needs to provide a rare earth phosphor using Eu to solve the technical deficiencies of the above rare earth phosphors²⁺The ion-doped glass replaces blue fluorescent powder to manufacture the packaging shell of the white light LED, so that the packaging shell can absorb ultraviolet rays, avoid ultraviolet pollution and convert the ultraviolet rays into useful visible light.

The invention provides a technical scheme for solving the technical problem that luminescent transparent glass containing europium ion self-reduction capability and a preparation method thereof comprise the following steps:

1) weighing the following raw materials in parts by weight:

BaCO₃57.92 parts, ZnO 23.91 parts, SiO₂17.65 parts, Eu₂O₃0.52-2.6 parts of glass fluxing agent, 10-15 parts of glass fluxing agent, 0.68-4.08 parts of crystal nucleus agent and 1.18 parts of glass clarifying agent.

The glass fluxing agent is preferably boric acid; the crystal nucleus agent is preferably phosphate or fluoride, and more preferably ammonium dihydrogen phosphate; the glass fining agent is preferably a sulfate salt, more preferably sodium sulfate.

Grinding the weighed raw materials in an agate mortar at room temperature for 30min, and uniformly mixing to obtain a glass precursor for later use.

2) Putting the precursor in the step 1) into a corundum crucible, putting the precursor and the crucible into a silicon-molybdenum furnace, preserving heat for 2 hours at 1400 ℃, and melting and homogenizing the precursor into glass liquid. Taking out the molten glass, pouring the molten glass into a graphite mold for molding, moving the molded glass into a preheated resistance furnace, annealing the molded glass at the temperature of 600 ℃ for 30min, and naturally cooling the molded glass to room temperature to obtain the glass with the components of BaZnSiO₄:x(Eu³⁺+Eu²⁺):yB₂O₃:zP₂O₅:0.028Na₂SO₄Wherein x =0.01-0.05, y =0.55-0.83, and z = 0.01-0.06.

3) Cutting and polishing the glass sample obtained in the step 2), and testing the luminescence property of the glass sample.

The temperature schedule of the silicon-molybdenum furnace in the step 2) is as follows: from room temperature, the temperature is raised to 1000 ℃ at the speed of 10 ℃/min, then raised to 1400 ℃ at the speed of 5 ℃/min, and the temperature is kept for 2 hours. The temperature schedule in the resistance furnace is as follows: from room temperature, the temperature is raised to 600 ℃ at the speed of 5 ℃/min, and the temperature is kept for 0.5 hour.

In the step 3), for convenience of research, the glass sample is ground into powder and then the luminous performance of the glass sample is tested, and the test instrument is a fluorescence spectrophotometer (model: HITACHI F-4500, Japan).

Compared with the prior art, the invention has at least the following beneficial effects:

1) the europium-doped silicate transparent luminescent glass material is prepared in one step by adopting a high-temperature melting method, fluorescent powder and glass powder do not need to be mixed in advance, the glass melting temperature is reduced by adding boric acid, and sodium sulfate is added to serve as a glass clarifier and a defoaming agent, so that the rare earth luminescent glass which is simple in preparation process, low in melting point, uniform in texture and higher than 90% in visible light transmittance is obtained.

2) The fluorescent glass prepared by the invention does not need to provide a reducing atmosphere in the whole process and is prepared in a single substrate (BaZnSiO)₄) The self-reduction of trivalent europium ions can be realized, the reduction degree is high, and the luminescence property is excellent.

3) The fluorescent glass prepared by the invention can realize fine control of light emitted from magenta to blue under different excitation wavelengths.

Drawings

FIG. 1 shows a sample of BaZnSiO luminescent glass obtained in example 2 of the present invention₄:0.01(Eu³⁺+Eu²⁺):0.83B₂O₃:zP₂O₅:0.028Na₂SO₄And (z = 0.05).

FIG. 2 shows a sample of BaZnSiO luminescent glass obtained in example 2 of the present invention₄:0.01(Eu³⁺+Eu²⁺):0.83B₂O₃:zP₂O₅:0.028Na₂SO₄(z =0.05) optical transmittance spectrum (product thickness)2.58 mm).

FIG. 3 shows BaZnSiO as a luminescent glass sample obtained in example 1 of the present invention₄:0.01(Eu³⁺+Eu²⁺):0.55B₂O₃:0.05P₂O₅:0.028Na₂SO₄Excitation and emission spectrum of (Eu)³⁺Characteristic spectrum).

FIG. 4 shows BaZnSiO as a luminescent glass sample obtained in example 1 of the present invention₄:0.01(Eu³⁺+Eu²⁺):0.55B₂O₃:0.05P₂O₅:0.028Na₂SO₄Excitation and emission spectrum of (Eu)²⁺Characteristic spectrum).

FIG. 5 shows BaZnSiO as a luminescent glass sample obtained in example 2 of the present invention₄:0.01(Eu³⁺+Eu²⁺):0.83B₂O₃:zP₂O₅:0.028Na₂SO₄Emission spectra of the powder preparation (z =0.05) at different excitation wavelengths of 285-350 nm.

FIG. 6 shows BaZnSiO as a luminescent glass sample obtained in example 2 of the present invention₄:0.01(Eu³⁺+Eu²⁺):0.83B₂O₃:zP₂O₅:0.028Na₂SO₄XRD pattern of the powder article of (z = 0.05).

FIG. 7 shows a sample of BaZnSiO luminescent glass obtained in example 2 of the present invention₄:0.01(Eu³⁺+Eu²⁺):0.83B₂O₃:zP₂O₅:0.028Na₂SO₄The CIE diagram of the powder preparation of (z =0, 0.05) at different excitation wavelengths of 285-340 nm.

Detailed Description

The present invention will be further explained with reference to the accompanying drawings and specific embodiments, which are to be construed as illustrative and not limiting the scope of the invention.

Example 1

1) Respectively weighing raw materials BaCO according to the molar ratio of 1:1:1:0.01: y:0.05:0.28 (wherein y =0, 0.28, 0.55 and 0.83)₃，ZnO，SiO₂，Eu₂O₃，H₃BO₃，NH₄H₂PO₄，Na₂SO₄Grinding the weighed raw materials in an agate mortar for 30min at room temperature, and uniformly mixing to obtain a glass precursor for later use.

2) Putting the precursor in the step 1) into a corundum crucible, putting the precursor and the crucible into a silicon-molybdenum furnace, preserving heat for 2 hours at 1400 ℃, and melting and homogenizing the precursor into glass liquid. And taking out the molten glass, pouring the molten glass into a graphite mold for molding, moving the molded glass into a preheated resistance furnace, annealing the molded glass for 30min at the temperature of 600 ℃, and naturally cooling the molded glass to room temperature along with the temperature of the furnace to obtain an initial sample.

3) Cutting and grinding a part of the initial sample obtained in the step 2), grinding a part of the initial sample into powder, and testing the luminous performance of the powder.

The sample without boric acid added in step 2) was not melted, while the samples with 0.28, 0.55, 0.83 mole percent boric acid added, respectively, were melted, but the sample with 0.28 boric acid added was not melted uniformly. Along with the increase of the addition amount of the boric acid, the melting effect is better and better, which shows that the addition of the boric acid can improve the melting condition of the sample, is beneficial to the melting of the sample, reduces the temperature for preparing the glass sample and saves energy.

Example 2

1) Respectively weighing raw materials BaCO according to the molar ratio of 1:1:1:0.01:0.83: z:0.28 (wherein z =0, 0.01, 0.02, 0.03, 0.04, 0.05 and 0.06)₃，ZnO，SiO₂，Eu₂O₃，H₃BO₃，NH₄H₂PO₄，Na₂SO₄Grinding the weighed raw materials in an agate mortar for 30min at room temperature, and uniformly mixing to obtain a glass precursor for later use.

The fluorescence property of the product is tested by adopting 340nm exciting light, and the test result shows that NH with different concentrations is added₄H₂PO₄The luminescence property of the product is different with NH₄H₂PO₄The trend that the luminous intensity of divalent europium increases and then decreases when the doping concentration is increased is in NH₄H₂PO₄When the doping amount is 0.05, the characteristic emission band intensity of divalent europium is the maximum, the reduction efficiency of trivalent europium ions is the maximum, and the blue luminous intensity is the strongest.

Referring to fig. 1 and 2, the prepared glass sample is natural and uniform in integral texture, transparent and clear, and from an optical transmittance spectrum, the transmittance of the glass sample to visible light is higher than 90%, and the passing rate to ultraviolet, especially near ultraviolet is low, so that the requirement of intercepting exciting light near ultraviolet in the initial design is basically met.

Referring to FIGS. 3 and 4, BaZnSiO is produced₄:0.01(Eu³⁺+Eu²⁺):0.55B₂O₃:0.05P₂O₅:0.028Na₂SO₄Through the test: eu exists at 612nm under the excitation of 285-350nm exciting light³⁺Characteristic peak with Eu at 390-470nm²⁺Characteristic of a band-shaped emission band, and Eu as the excitation wavelength increases³⁺The intensity of the emitted light gradually decreases, Eu²⁺Gradually increasing the luminous intensity of Eu³ ⁺The reduction ratio of (a) gradually increases.

Referring to FIG. 5, the product BaZnSiO₄:0.01(Eu³⁺+Eu²⁺):0.55B₂O₃:0.05P₂O₅:0.028Na₂SO₄The XRD pattern of the product has no obvious crystal peak, which indicates that the product is luminescent glass.

Referring to FIG. 6, the product BaZnSiO₄:0.01(Eu³⁺+Eu²⁺):0.55B₂O₃:0.05P₂O₅:0.028Na₂SO₄CIE coordinates under the excitation light of 285nm, 290nm, 300nm, 310nm, 320nm, 330nm and 340nm are respectively as follows: (0.359,0.291), (0.339,0.284), (0.315,0.275), (0.2)89,0.261), (0.294,0.257), (0.274,0.248), (0.268,0.244) substantially enabling a controllable adjustment of the emitted light from the magenta to blue region.

Embodiment 3

1) Respectively weighing raw materials BaCO according to the molar ratio of 1:1:1: x:0.83:0.05:0.28 (wherein x =0.01, 0.02, 0.03, 0.04 and 0.05)₃，ZnO，SiO₂，Eu₂O₃，H₃BO₃，NH₄H₂PO₄，Na₂SO₄Grinding the weighed raw materials in an agate mortar for 30min at room temperature, and uniformly mixing to obtain a glass precursor for later use.

The product is excited by 285nm and 340nm exciting light respectively, and Eu is compared³⁺And Eu²⁺The characteristic of the emitted light, the added Eu can be obtained₂O₃The more the content of Eu is³⁺The stronger the emitted light intensity of, and Eu²⁺The weaker the emitted light intensity is, the quenching phenomenon probably caused by the overhigh concentration of the rare earth, and the optimal molar concentration of the europium trioxide is 1 percent.

Claims

1. The europium ion-containing self-reducing luminescent glass is characterized by adopting BaZnSiO₄The glass matrix is used for efficiently reducing trivalent europium by a high-temperature melting method in an air atmosphere and comprises the following raw materials in parts by weight: BaCO₃57.92 parts, ZnO 3.91 parts, SiO₂17.65 parts, Eu₂O₃x parts, y parts of a melting agent, z parts of a crystal nucleating agent and 1.18 parts of a glass refining agent, wherein x =0.52-2.6, y =10-15 and z =0.68-4.08, and the matrix is BaZnSiO₄GlassA matrix, the fusing agent is H₃BO₃The crystal nucleus agent is NH₄H₂PO₄Or CaF₂The glass clarifying agent is Na₂SO₄。

2. The europium ion-containing self-reducing luminescent glass of claim 1, which comprises the following raw materials in parts by weight: BaCO₃57.92 parts, ZnO 3.91 parts, SiO₂17.65 parts, Eu₂O₃x part, H₃BO₃15 parts of NH₄H₂PO₄3.4 parts of Na₂SO₄1.18 parts, wherein x = 0.52-2.6.

3. The europium ion-containing self-reducing luminescent glass of claim 1, which comprises the following raw materials in parts by weight: BaCO₃57.92 parts, ZnO 3.91 parts, SiO₂17.65 parts, Eu₂O₃0.52 part of H₃BO₃y parts, NH₄H₂PO₄3.4 parts of Na₂SO₄1.18 parts, wherein y = 10-15.

4. The europium ion-containing self-reducing luminescent glass of claim 1, which comprises the following raw materials in parts by weight: BaCO₃57.92 parts, ZnO 3.91 parts, SiO₂17.65 parts, Eu₂O₃0.52 part of H₃BO₃15 parts of NH₄H₂PO₄z part, Na₂SO₄1.18 parts, wherein z = 0.68-4.08.

5. The europium ion-containing self-reducing luminescent glass according to any one of claims 1 to 4, comprising the following steps:

(1) weighing raw materials in parts by weight, and grinding the raw materials in an agate mortar for 30 minutes to obtain a glass precursor;

(2) and (2) putting the precursor obtained in the step (1) into a corundum crucible, putting the precursor and the crucible into a silicon-molybdenum furnace for firing, melting and homogenizing the precursor into molten glass, taking out the molten glass, pouring the molten glass into a graphite mold for molding, then moving the molded glass into a preheated resistance furnace, preserving heat, naturally cooling to room temperature along with the temperature of the furnace, cutting and polishing to obtain the product.

6. The europium ion-containing self-reducing luminescent glass according to claim 5, wherein the firing process is carried out for 100min to 1000 ℃, 80min to 1400 ℃ and 2 h.

7. The europium ion-containing self-reducing luminescent glass of claim 5, wherein the atmosphere used in the Si-Mo furnace is air.

8. The europium ion-containing self-reducing luminescent glass of claim 5, wherein the resistance furnace is preheated for 120min to 600 ℃ and then is kept warm for 30 min.