CN106244144A - A kind of purple LED blue colour fluorescent powder and preparation method thereof and the lighting source being made from - Google Patents

Abstract

The invention relates to a blue fluorescent powder for purple LEDs, a preparation method thereof and an illumination light source made from the same. The blue fluorescent powder of the present invention has a chemical structural formula: M _10-y (P _1-3b/5 N _b O ₄ ) ₆ X ₂ :yEu ²⁺ , wherein M is selected from Ca, Sr, Ba and Mg One or two, X is one or both of F and Cl, y represents the molar coefficient, and 0<y<1, b is the number of atoms replaced by N, and 0<b<5/3. The fluorescent powder prepared by using reducing hydrogen atmosphere and ammonium chloride atmosphere has strong absorption at 250nm-420nm, its emission spectrum is in the range of 430nm-550nm, and has the characteristics of good crystallinity and high luminous intensity. High color rendering white LED light sources can be prepared by using the luminescent material of the present invention in combination with ultraviolet or near-ultraviolet LEDs and other luminescent materials such as green fluorescent powder and red fluorescent powder.

Description

A kind of blue fluorescent powder for violet light LED and its preparation method and the photoluminescent powder made from it Mingyuan

technical field

The invention relates to a blue fluorescent powder for ultraviolet or near-ultraviolet LEDs, and provides a preparation method of the fluorescent material, which belongs to the field of fluorescent powder materials.

Background technique

At present, the main method of realizing white LED is to excite YAG yellow phosphor powder with blue LED chip. This method has the advantages of simple process and low cost, but the white LED produced by it has unbalanced emission wavelength and high peak intensity of blue light. The problem that can easily cause sleep disturbance is the "blue light problem". On the other hand, white LEDs composed of blue LEDs and phosphors do not contain violet light, so there will be differences in color compared with sunlight. Although red phosphors can be added to improve its color rendering index, the color rendering index is very low. It is difficult to achieve more than 95.

The method of preparing white light LEDs with three primary color phosphors excited by purple light chips has received extensive attention and research in recent years, because the color of this type of white light LEDs is only determined by phosphors, and it has stable color, high color rendering index, and color reproduction. good points. It can output all light in the visible light wavelength range, and can realize ideal white light close to sunlight, and the Ra can reach more than 95. In addition, purple LEDs are not prone to the problem of reduced light efficiency, and the density of the driving current can be increased by 5-10 times.

In the white light LED excited by the purple light chip, the blue light is realized by exciting the blue phosphor powder through the ultraviolet or near ultraviolet LED chip, and the peak intensity of the blue light can be controlled within a certain intensity range. However, the commercial tricolor blue phosphor BaMgAl ₁₀ O ₁₇ :Eu ^{2 +} (BAM) has a high synthesis temperature (1600-1800°C), low chemical stability and high light attenuation under near-ultraviolet light excitation, and The absorption of BAM powder at 400nm is very weak, and it cannot be well matched with InGaN chips (350-410nm), which limits the application in violet LEDs, and the luminous efficiency of ultraviolet-excited white LEDs is still comparable to that of rare earth three-color fluorescent lamps. There is a large gap, mainly due to the lack of blue below 450nm and green around 500nm.

Contents of the invention

The object of the present invention is to provide a method for synthesizing europium-activated blue fluorescent powder in a dual atmosphere in which hydrogen and ammonium chloride atmospheres work together, so that the synthesized fluorescent powder has higher luminous intensity and better powder uniformity, and is compatible with ultraviolet or ultraviolet light. The near-ultraviolet chip is more matched, so as to achieve the purpose of high color rendering white LED application. The blue fluorescent powder prepared by the invention has strong absorption at 250nm-420nm, which can better match with InGaN chips, and its emission spectrum is in the range of 430nm-550nm, which can just make up for the missing parts of blue light and green light.

The blue fluorescent powder excited by the purple light LED provided by the invention has the following chemical structural formula:

M _10－y (P _1-3b/5 N _b O ₄ ) ₆ X ₂ :yEu ²⁺ , wherein M is one or two selected from Ca, Sr, Ba and Mg, X is F and Cl One or both, y represents the molar coefficient, and 0<y<1, b is the number of atoms replaced by N, and 0<b<5/3.

In a preferred embodiment of the present invention, M is preferably Sr or a combination of Sr and Ba elements, X is preferably Cl or F; y is preferably 0.01-0.6, b is preferably 0.2-1.2,

M is more preferably Sr; X is preferably Cl, y is more preferably 0.01-0.3, and b is more preferably 0.2-1.

Y is most preferably 0.1 to 0.2, and b is most preferably 0.4 to 0.8.

Further, the wavelength range of the ultraviolet or near ultraviolet light is 250nm-420nm, and the emission spectrum of the blue fluorescence is in the range of 430nm-550nm.

The present invention provides the preparation method of above-mentioned blue fluorescent powder for violet light LED, and this method comprises the following steps:

Step 1: Using compounds containing alkaline earth metal ions M ²⁺ , europium ions Eu ³⁺ , chloride ions Cl ^- and/or fluorine ions F ^- , phosphorus ions P ⁵⁺ , and nitrogen ions N ³⁺ as raw materials, according to blue The chemical structural formula M _10－y (P _1-3b/5 N _b O ₄ ) ₆ X ₂ : the stoichiometric number shown in yEu ²⁺ of the phosphor powder, weigh the raw materials respectively, and mix these raw materials with the flux evenly, and grind thoroughly in a mortar;

The second step: put the ground material in the first step into a crucible, and carry out calcination and synthesis under a hydrogen reducing atmosphere. The calcination temperature is 1200-1400° C., and the calcination time is 2-5 hours. After calcining, it is naturally cooled, pulverized, sieved, washed with water, washed with alcohol, sieved, and dried to obtain the blue fluorescent powder of the present invention.

The compound containing alkaline earth metal ion M ²⁺ is one of carbonate, nitrate or phosphate of alkaline earth metal; the compound containing europium ion Eu ³⁺ is europium oxide, europium nitrate or europium sulfate One; the compound containing chloride ion Cl ^- is alkaline earth metal chloride MCl ₂ ; the compound containing fluorine ion F ^- is alkaline earth metal fluoride MF ₂ ; the compound containing phosphorus ion P ⁵⁺ and nitrogen ion The N ^3- compound is one of ammonium dihydrogen phosphate or diammonium hydrogen phosphate.

Preferably: the compound containing alkaline earth metal ion M ²⁺ is carbonate of alkaline earth metal; the compound containing europium ion Eu ³⁺ is europium oxide; the compound containing chloride ion ^Cl- is chloride of alkaline earth metal MCl ₂ ^; the compound containing fluorine ion F- is alkaline earth metal fluoride MF ₂ ; the compound containing phosphorus ion P ⁵⁺ and nitrogen ion N ^3- is ammonium dihydrogen phosphate.

The hydrogen reducing atmosphere also includes an ammonium chloride atmosphere.

The ammonium chloride gas is provided by solid ammonium chloride, ammonium chloride is placed around the crucible and heated to volatilize the ammonium chloride to form ammonium chloride in gas phase.

In the second step, the hydrogen reducing atmosphere is provided by _H2 , and the concentration ratio is 2% to 4%; the amount of solid ammonium chloride is 10wt% to 15wt% of the total mass of the raw materials,

The concentration ratio of _H2 is preferably 4%, and the amount of solid ammonium chloride is 10% of the total mass of the raw materials.

In the first step, the flux is one or more of AlF ₃ , BaF ₂ , H ₃ BO ₃ ; the amount of the flux is 0.1wt%-1.0wt% of the total mass of the raw materials.

The fluxing agent is preferably BaF ₂ , and the amount of the fluxing agent is 0.6wt%-0.8wt% of the total mass of the raw materials.

After the flux and the raw materials are uniformly mixed in a mortar, they are sieved through a 200-mesh sieve, and the sieved mixture is subjected to the second step of synthesis and calcination.

The application of the above-mentioned blue phosphor is to apply the blue phosphor to lighting displays and photoluminescent devices using ultraviolet or near-ultraviolet light as an excitation source for chromaticity adjustment.

The effect of ammonium chloride atmosphere among the present invention is:

1. A chlorine substitution reaction occurs to provide part of the Cl in the M _10-y (P _1-3b/5 N _b O ₄ ) ₆ X ₂ :yEu ²⁺ blue phosphor;

2. Working together with MCl ₂ or MF ₂ in the mixed raw material, first of all, the ammonium chloride atmosphere will generate a large amount of gas and form a large number of pores during the reaction process, which will make the agglomerated material looser and even dispersible into smaller aggregates; then MCl ₂ or MF ₂ plays a role of fusion between these loose small aggregates, and crystallizes a more complete single crystal grain, making the crystal grains smaller and more uniform.

3. A large number of pores formed in the process of 2, on the one hand, allow hydrogen to enter more easily to ensure the adequacy of reduction; on the other hand, can effectively reduce the reaction temperature of the system.

The advantages of the present invention are:

1. The blue phosphor powder of the present invention has a very broad excitation peak, has strong absorption at 250nm-420nm, and can have a good match with ultraviolet or near-ultraviolet LED chips;

2. The emission spectrum of the phosphor powder involved in the present invention is within the range of 430nm to 550nm. Its chromaticity is pure, its crystallinity is high, its luminous efficiency is remarkable, and it has high commercial application value. After packaging and evaluation, its color rendering index can reach 96, And the stability after encapsulation is also good;

3. The blue fluorescent powder of the present invention has good crystallization properties, high color rendering, and uniform particle size;

4. The present invention adopts clean hydrogen reducing atmosphere and ammonium chloride atmosphere to work together to produce blue fluorescent powder. The use of clean hydrogen as the reducing atmosphere will not cause serious pollution to the environment during the reaction process; the use of ammonium chloride atmosphere can reduce the reaction temperature of the system during the sintering process, save energy, and have less impact on the environment. On the one hand, the use of ammonium chloride atmosphere can improve the crystallization performance of the crystal, reduce the particle size of the powder particles, ensure the uniformity of the powder particles, and increase the luminous intensity of the powder.

5. The preparation method of the blue fluorescent powder of the present invention has the advantages of easy-to-obtain raw materials and abundant sources, low price, simple process, low calcination temperature, easy operation, low equipment requirements, energy saving, low cost and no waste water in the production process Exhaust gas emission, environmental friendliness and other advantages.

Description of drawings

Fig. 1 is a graph comparing the excitation and emission spectra of the blue phosphor prepared in Example 1 and the blue phosphor prepared in Example 2 (without adding ammonium chloride atmosphere under the same conditions).

Fig. 2 is a graph comparing the excitation and emission spectra of the blue phosphor prepared in Example 3 and the blue phosphor prepared in Example 4 (without adding ammonium chloride atmosphere under the same conditions).

FIG. 3 is the position of the blue phosphor prepared in Example 1 in CIE-1931 coordinates.

FIG. 4 is a scanning electron micrograph of the blue phosphor prepared in Example 1. FIG.

Fig. 5 is a comparison result of 3200K packaged ultraviolet chip + blue powder packaged in Example 1 and the packaged blue light chip with the same color temperature.

Fig. 6 is a comparison result of the 5600K packaged ultraviolet chip + the blue powder packaged in Example 2 and the packaged blue light chip with the same color temperature.

detailed description

The blue phosphor powder prepared by the present invention and the preparation method thereof will be further described in detail below in conjunction with the examples.

The blue phosphor powder excited by ultraviolet or near ultraviolet LED provided by the present invention has the following chemical structural formula:

M _10－y (P _1-3b/5 N _b O ₄ ) ₆ X ₂ :yEu ²⁺ , wherein M is one or two selected from Ca, Sr, Ba and Mg, X is F and Cl One or both, y represents the molar coefficient, and 0<y<1, b is the number of atoms replaced by N, and 0<b<5/3.

In a preferred embodiment of the present invention, M is preferably Sr or Ba element, more preferably Sr; X is preferably Cl; y represents the molar coefficient, preferably 0.01-0.3, more preferably 0.1-0.2, and b is N replacing P The number of atoms is preferably 0.2 to 1, more preferably 0.4 to 0.8.

The present invention provides the preparation method of above-mentioned blue fluorescent powder for violet light LED, and this method comprises the following steps:

Step 1: Weigh the raw materials MCO ₃ and dihydrogen phosphate respectively according to the stoichiometric numbers shown in the chemical structural formula M ₁₀ (P _1-3b/5 N _b O ₄ ) ₆ X ₂ :yEu ²⁺ of the blue phosphor Ammonium, MCl ₂ and Eu ₂ O ₃ , these raw materials are evenly mixed with flux, and put into a mortar and thoroughly ground;

The second step: put the above-mentioned ground materials into an aluminum crucible, and place a certain amount of ammonium chloride around the crucible, and heat it to volatilize the ammonium chloride to form ammonium chloride in a gas phase state. The calcination synthesis is carried out under the combined action of ammonium chloride atmosphere, the calcination temperature is 1200-1400 DEG C, and the calcination time is 2-5 hours. After calcining, it is naturally cooled, pulverized, sieved, washed with water, washed with alcohol, sieved, and dried to obtain the blue fluorescent powder of the present invention.

In the first step, the flux is one or more of AlF ₃ , BaF ₂ , H ₃ BO ₃ , and preferably BaF ₂ ; the amount of flux is 0.1wt of the total mass of the raw materials % to 1.0 wt%, and preferably 0.6 wt% to 0.8 wt%.

After the flux and the raw materials are uniformly mixed in a mortar, they are sieved through a 200-mesh sieve, and the sieved mixture is subjected to the second step of synthesis and calcination.

In the second step, the reducing atmosphere is provided by _H2 , and its concentration ratio is not more than 4%, which is 2% to 4%, preferably 4%; the ammonium chloride atmosphere is provided by ammonium chloride solid, and its dosage is It is 10wt%-15wt% of the total mass of the raw materials, preferably 10%.

Next, the present invention will be further described in more detail through examples, but the present invention is not limited to these examples.

Example 1

Weigh 45g ammonium dihydrogen phosphate, 2.3g europium oxide, 17g strontium chloride, 75g strontium carbonate according to the chemical structural formula of the blue phosphor, and weigh 0.6wt% flux BaF ₂ of the total mass of the raw materials to mix with the raw materials. Mixing the weighed raw material and flux in a mortar for grinding, after grinding for 30 minutes, sieving the ground material through a 200-mesh sieve to obtain the sieved material;

Put the above-mentioned sieved material into the crucible, then weigh 10wt% ammonium chloride of the total mass of the raw material and place it around the crucible, heat the ammonium chloride to volatilize and form ammonium chloride in the gas phase state, and mix the ammonium chloride with 4% hydrogen reducing atmosphere. The calcination synthesis is carried out under the combined action of ammonium chloride atmosphere, the calcination temperature is 1200°C, and the calcination time is 3h. Then cool down, pulverize, sieve, wash with water, wash with alcohol, sieve, and dry to obtain the required Sr _9.8 (P _0.76 N _0.4 O ₄ ) ₆ Cl ₂ :0.2Eu ²⁺ phosphor.

Figure 1 shows the comparison of the excitation and emission spectra of the blue phosphor powder prepared in this example and the blue phosphor powder prepared in Example 2 (without the addition of ammonium chloride atmosphere under the same conditions).

The position of the blue phosphor prepared by the method of this embodiment in the CIE-1931 coordinates is shown in FIG. 3 .

The scanning electron microscope image of the blue phosphor prepared by the method of this embodiment is shown in FIG. 4 .

The blue phosphor prepared by the method of this embodiment and the ultraviolet chip and the green and red phosphor packaged at 3200K are compared with the blue chip packaged color temperature of 3200K as shown in Figure 5. The color rendering index can reach 97, while After the color temperature blue light chip is packaged, its color rendering index is only 87.

Example 2

Weigh 45g ammonium dihydrogen phosphate, 2.3g europium oxide, 17g strontium chloride, 75g strontium carbonate according to the chemical structural formula of the blue phosphor, and weigh 0.6wt% flux BaF ₂ of the total mass of the raw materials to mix with the raw materials. Mixing the weighed raw material and flux in a mortar for grinding, after grinding for 30 minutes, sieving the ground material through a 200-mesh sieve to obtain the sieved material;

Put the above-mentioned sun-dried materials into a crucible, and perform calcination under a 4% hydrogen reducing atmosphere, the calcination temperature is 1200°C, and the calcination time is 3h. After cooling, crushing, sieving, washing with water, washing with alcohol, sieving, and drying, the required Sr _9.8 (P _0.76 N _0.4 O ₄ ) ₆ Cl ₂ :0.2Eu ²⁺ phosphor is obtained.

Example 3

According to the chemical structural formula of the blue fluorescent powder, weigh 42g ammonium dihydrogen phosphate, 2.2g europium oxide, 17g strontium chloride, 54g strontium carbonate, and 22g barium carbonate, and weigh 0.8wt% of the total mass of raw materials as flux HBO ₃ Mix with stock. Mixing the weighed raw material and flux in a mortar for grinding, after grinding for 30 minutes, sieving the ground material through a 200-mesh sieve to obtain the sieved material;

Put the above-mentioned sieved material into the crucible, then weigh 10wt% ammonium chloride of the total mass of the raw material and place it around the crucible, heat the ammonium chloride to volatilize and form ammonium chloride in the gas phase state, and mix the ammonium chloride with 4% hydrogen reducing atmosphere. The calcination synthesis is carried out under the combined action of ammonium chloride atmosphere, the calcination temperature is 1300°C, and the calcination time is 5h. Then cool down, pulverize, sieve, wash with water, wash with alcohol, sieve, and dry to obtain the required Sr _7.9 Ba _1.9 (P _0.64 N _0.6 O ₄ ) ₃ Cl ₆ :0.2Eu ²⁺ phosphor.

The comparison diagram of the excitation and emission spectra of the blue phosphor prepared in this example and the blue phosphor prepared in Example 4 (without adding ammonium chloride atmosphere) is shown in FIG. 2 .

The blue phosphor prepared by the method of this embodiment, the ultraviolet chip and the green and red phosphor packaged at 5600K are compared with the blue chip packaged color temperature of 5600K as shown in Figure 6. The color rendering index can reach 96, while the same After the color temperature blue light chip is packaged, its color rendering index is only 86.

Example 4

According to the chemical structural formula of the blue fluorescent powder, weigh 42g ammonium dihydrogen phosphate, 2.2g europium oxide, 17g strontium chloride, 54g strontium carbonate, and 22g barium carbonate, and weigh 0.8wt% of the total mass of raw materials as flux HBO ₃ Mix with stock. Mixing the weighed raw material and flux in a mortar for grinding, after grinding for 30 minutes, sieving the ground material through a 200-mesh sieve to obtain the sieved material;

The above sun-dried materials were put into a crucible, and calcined in a reducing atmosphere of 4% hydrogen, the calcining temperature was 1300° C., and the calcining time was 5 hours. Then cool down, pulverize, sieve, wash with water, wash with alcohol, sieve, and dry to obtain the required Sr _7.9 Ba _1.9 (P _0.64 N _0.6 O ₄ ) ₆ Cl ₂ :0.2Eu ²⁺ phosphor.

Example 5

Take by weighing 44g ammonium dihydrogen phosphate, 3.4g europium oxide, 16g barium chloride, 58g strontium carbonate, 14g barium carbonate, and 2.5g calcium carbonate according to the chemical structural formula of the blue fluorescent powder, and weigh 1.0wt% of the total mass of raw materials Flux BaF ₂ to mix with raw materials. Mixing the weighed raw material and flux in a mortar for grinding, after grinding for 30 minutes, sieving the ground material through a 200-mesh sieve to obtain the sieved material;

The above-mentioned sieved material is put into the crucible, and then the ammonium chloride with 11wt% of the total mass of the raw material is weighed and placed around the crucible, and the ammonium chloride is heated to volatilize to form ammonium chloride in the gas phase state. The calcination synthesis is carried out under the combined action of ammonium chloride atmosphere, the calcination temperature is 1250°C, and the calcination time is 3h. Then cool down, pulverize, sieve, wash with water, wash with alcohol, sieve, and dry to obtain the required Sr _8.2 Ba _1.1 Ca _0.4 (P _0.7 N _0.5 O ₄ ) ₆ Cl ₂ :0.3Eu ²⁺ phosphor.

Example 6

Take by weighing 43g ammonium dihydrogen phosphate, 3.3g europium oxide, 15g barium fluoride, 57g strontium carbonate, and 18g barium carbonate according to the chemical structural _formula of the blue fluorescent powder, and weigh 1.0wt% flux BaF of the total mass of raw materials Mix with stock. Mixing the weighed raw material and flux in a mortar for grinding, after grinding for 30 minutes, sieving the ground material through a 200-mesh sieve to obtain the sieved material;

The above-mentioned sieved material is put into the crucible, and then the ammonium chloride with 10wt% of the total mass of the raw material is weighed and placed around the crucible, and the ammonium chloride is heated to volatilize to form ammonium chloride in the gas phase state. The calcination synthesis is carried out under the combined action of ammonium chloride atmosphere, the calcination temperature is 1250°C, and the calcination time is 3h. Then cool down, pulverize, sieve, wash with water, wash with alcohol, sieve, and dry to obtain the required Sr _8.2 Ba _1.5 (P _0.82 N _0.3 O ₄ ) ₆ Cl ₂ :0.3Eu ²⁺ phosphor.

Example 7

According to the chemical structural formula of the blue fluorescent powder, weigh 44g ammonium dihydrogen phosphate, 3.3g europium oxide, 17g strontium chloride, 61g strontium carbonate, and 13g barium carbonate, and weigh 1.0wt% of the total mass of raw materials as a flux HBO ₃ Mix with stock. Mixing the weighed raw material and flux in a mortar for grinding, after grinding for 30 minutes, sieving the ground material through a 200-mesh sieve to obtain the sieved material;

The above-mentioned sieved material is put into the crucible, and then the ammonium chloride with 14wt% of the total mass of the raw material is weighed and placed around the crucible, and the ammonium chloride is heated to volatilize to form ammonium chloride in the gas phase state. In a 2% hydrogen reducing atmosphere and The calcination synthesis is carried out under the combined action of ammonium chloride atmosphere, the calcination temperature is 1300°C, and the calcination time is 5h. Then cool down, pulverize, sieve, wash with water, wash with alcohol, sieve, and dry to obtain the required Sr _8.5 Ba ₁ Ca _0.2 (P _0.7 N _0.5 O ₄ ) ₆ Cl ₂ :0.3Eu ²⁺ phosphor.

Example 8

Take by weighing 42g ammonium dihydrogen phosphate, 3.2g europium oxide, 16g strontium chloride, 45g strontium carbonate, and 30g barium carbonate according to the chemical structural formula of the blue fluorescent powder, and weigh 0.6wt% flux HBO ₃ and 0.4wt% flux AlF ₃ to mix with raw materials. Mixing the weighed raw material and flux in a mortar for grinding, after grinding for 30 minutes, sieving the ground material through a 200-mesh sieve to obtain the sieved material;

The above-mentioned sieved material is put into the crucible, and then the ammonium chloride with 12wt% of the total mass of the raw material is weighed and placed around the crucible, and the ammonium chloride is heated to volatilize to form ammonium chloride in the gas phase state. In a 3% hydrogen reducing atmosphere and The calcination synthesis is carried out under the combined action of ammonium chloride atmosphere, the calcination temperature is 1200°C, and the calcination time is 5h. Then cool down, pulverize, sieve, wash with water, wash with alcohol, sieve, and dry to obtain the desired Sr ₇ Ba _2.5 Ca _0.2 (P _0.52 N _0.8 O ₄ ) ₆ Cl ₂ :0.3Eu ²⁺ phosphor.

Example 9

According to the chemical structural formula of the blue fluorescent powder, weigh 42g ammonium dihydrogen phosphate, 2.1g europium oxide, 16g strontium fluoride, 14g barium chloride, 49g strontium carbonate, and 28g barium carbonate, and weigh 0.5wt% of the total mass of raw materials. Flux AlF ₃ to mix with raw materials. Mixing the weighed raw material and flux in a mortar for grinding, after grinding for 30 minutes, sieving the ground material through a 200-mesh sieve to obtain the sieved material;

The above-mentioned sieved material is put into the crucible, and then the ammonium chloride with 15wt% of the total mass of the raw material is weighed and placed around the crucible, and the ammonium chloride is heated to volatilize to form ammonium chloride in the gas phase state. The calcination synthesis is carried out under the combined action of ammonium chloride atmosphere, the calcination temperature is 1250°C, and the calcination time is 4h. Then cool down, pulverize, sieve, wash with water, wash with alcohol, sieve, and dry to obtain the required Sr _7.5 Ba _2.3 (P _0.4 NO ₄ ) ₆ F ₂ :0.2Eu ²⁺ phosphor.

Example 10

Take by weighing 42g ammonium dihydrogen phosphate, 6.5g europium oxide, 17g strontium fluoride, 55g strontium carbonate, and 17g barium carbonate according to the chemical structural formula of the blue fluorescent powder, and weigh 0.5wt% flux AlF of the total mass of raw materials ₃ and 0.5wt% flux BaF ₂ to mix with raw materials. Mixing the weighed raw material and flux in a mortar for grinding, after grinding for 30 minutes, sieving the ground material through a 200-mesh sieve to obtain the sieved material;

Put the above-mentioned sieved material into the crucible, then weigh 10wt% ammonium chloride of the total mass of the raw material and place it around the crucible, heat the ammonium chloride to volatilize and form ammonium chloride in the gas phase state, and mix the ammonium chloride with 4% hydrogen reducing atmosphere. The calcination synthesis is carried out under the combined action of ammonium chloride atmosphere, the calcination temperature is 1280°C, and the calcination time is 4h. Then cool down, pulverize, sieve, wash with water, wash with alcohol, sieve, and dry to obtain the required Sr ₈ Ba _1.4 (P _0.54 N _0.9 O ₄ ) ₆ F ₂ :0.6Eu ²⁺ phosphor.

Claims (16)

1. the blue colour fluorescent powder that purple LED excites, its chemical structural formula is as follows: M_10-y(P_1-3b/5N_bO₄)₆X₂:yEu²⁺,

Wherein M is one or both in Ca, Sr, Ba and Mg, and X is one or both in F and Cl, and y represents and mole is Number, and the atomic number that 0 ＜ y ＜ 1, b are N replacement P, and 0 ＜ b ＜ 5/3.

The blue colour fluorescent powder that purple LED the most according to claim 1 excites, wherein M is Sr or Sr Yu Ba element combinations, X is Cl or F；Y is 0.01～0.6, and b is 0.2～1.2,

The blue colour fluorescent powder that purple LED the most according to claim 2 excites, wherein M is Sr；X be Cl, y be 0.01～ 0.3, b is 0.2～1.

4. the blue colour fluorescent powder excited according to the purple LED described in Claims 2 or 3, wherein y is 0.1～0.2, b be 0.4～ 0.8。

The blue colour fluorescent powder that purple LED the most according to claim 1 excites, its medium ultraviolet or the wave-length coverage of black light For 250nm～420nm, the emission spectrum scope of described blue colour fluorescent powder is 430nm～550nm.

6., according to the preparation method of the arbitrary described purple LED blue colour fluorescent powder of claim 1-5, the method includes as follows Step:

The first step: to contain alkaline-earth metal ions M respectively²⁺, europium ion Eu³⁺, chloride ion Cl^-And/or fluorion F^-, phosphonium ion P^{5 +}, Nitrogen ion N³⁺Compound be raw material, according to the chemical structural formula M of blue colour fluorescent powder_10-y(P_1-3b/5N_bO₄)₆X₂:yEu²⁺Shown in Stoichiometric number, weigh raw material respectively, these raw materials are uniformly mixed with flux, and put in mortar and be fully ground；

Second step: by material ground for the first step, puts in crucible, carries out calcining synthesis, calcining under hydrogen reducing atmosphere Temperature is 1200～1400 DEG C, and calcination time is 2～5 hours.Through natural cooling after calcining, pulverizing, sieve, washing, alcohol is washed, and sieves Point, obtain the blue colour fluorescent powder of the present invention after drying.

Preparation method the most according to claim 6, described containing alkaline-earth metal ions M²⁺Compound be alkaline-earth metal One in carbonate, nitrate or phosphate；Described containing europium ion Eu³⁺Compound be europium oxide, europium nitrate or sulphuric acid One in europium；Described containing chloride ion Cl^-The chloride MCl that compound is alkaline-earth metal₂；Described containing fluorion F^-'s Compound is the fluoride MF of alkaline-earth metal₂；Described containing phosphonium ion P⁵⁺With Nitrogen ion N^3-Compound be ammonium dihydrogen phosphate or One in diammonium phosphate.

Preparation method the most according to claim 7, described containing alkaline-earth metal ions M²⁺Compound be alkaline-earth metal Carbonate；Described containing europium ion Eu³⁺Compound be europium oxide；Described containing chloride ion Cl^-Compound be alkaline-earth metal Chloride MCl₂；Described containing fluorion F^-The fluoride MF that compound is alkaline-earth metal₂；Described containing phosphonium ion P⁵⁺With Nitrogen ion N^3-Compound be ammonium dihydrogen phosphate.

Preparation method the most according to claim 6, also includes ammonium chloride atmosphere in described hydrogen reducing atmosphere.

Preparation method the most according to claim 9, described ammonium chloride atmosphere is provided by solid ammonium chloride, around crucible Place ammonium chloride, heat, make ammonium chloride volatilization form the ammonium chloride of gas phase state.

11. preparation methoies according to claim 10, described hydrogen reduction atmosphere is by H₂There is provided, concentration ratio be 2%～ 4%；Solid ammonium chloride consumption is 10wt%～15wt% of described raw material gross mass.

12. preparation methoies according to claim 11, H₂Concentration ratio is 4%, and solid ammonium chloride consumption is that described raw material is total Quality 10%.

13. preparation methoies according to claim 6, described flux is AlF₃, BaF₂, H₃BO₃In one or more；Help The consumption of flux is 0.1wt%～1.0wt% of described raw material gross mass.

14. preparation methoies according to claim 13, described flux is BaF₂, the consumption of flux is that described raw material is total 0.6wt%～0.8wt% of quality.

15. preparation methoies according to claim 6, described flux after mortar is mixed homogeneously, crosses 200 with described raw material Mesh sieve, the compound after sieving carries out the synthesis calcining of second step.

The application of the 16. arbitrary blue colour fluorescent powders of claim 1-5, for being applied to this blue colour fluorescent powder with ultraviolet or near ultraviolet Light is that the illumination of excitaton source shows and regulates for colourity in photo luminescent devices.