CN104212455B - A kind of Ce3+The garnet structure fluorescent material activated and its preparation method - Google Patents

Abstract

The present invention discloses a kind of Ce³⁺The garnet structure fluorescent material activated, chemical expression is: Mg_2-aA_aY_2-x-bB_bM₂N₂O₁₂:xCe³⁺In formula: A is one or more the combination in Ba, Sr, Ca, B is one or more the combination in Gd, La, Sc, M is the combination of one or both arbitrary proportions in Al, Ga, N is the combination of one or both arbitrary proportions in Si, Ge, x, a, b are respective molar fraction, their span is: 0.01≤x≤0.12,0≤a≤0.2,0≤b≤0.2. Fluorescent material provided by the invention wavelength be 460nm blue-light excited under, it is possible to sending wavelength region is 500 to the orange light of 750nm, it is possible to be applied in white light LEDs.

Description

A kind of Ce3+ activated garnet structure phosphor and preparation method thereof

technical field

The invention belongs to the technical field of luminescent materials, and in particular relates to a fluorescent powder used in semiconductor lighting, in particular to a fluorescent powder which can be effectively excited by a blue LED chip to emit orange-yellow light and a preparation method thereof.

Background technique

Among the manufacturing methods of white light LEDs, the method of coating yellow phosphor powder on blue InGaN chips has received the most attention because of its simplicity, low cost, and high efficiency of the obtained LED devices. Among the yellow phosphors used, Ce ³⁺ ion activated yttrium aluminum garnet (Y ₃ A1 ₅ O ₁₂ :Ce ³⁺ , referred to as YAG:Ce ³⁺ ) can efficiently absorb blue light and convert it into yellow light , thus becoming the most important commercial yellow phosphor. The efficiency of the white LED made of InGaN chip compounded with YAG:Ce ³⁺ phosphor can exceed 80lm/W, which is almost comparable to that of fluorescent lamps. However, due to the excessive green component and too little red component in the emission spectrum of the YAG:Ce ³⁺ phosphor, after compounding with the blue LED chip, it can only produce white light with a relative color temperature (CCT) higher than 4500K. Due to the cold tone and poor color rendering of this kind of white light, it can only be used for outdoor lighting sources such as street lamps and headlights, and is not suitable for indoor lighting sources, which seriously restricts the development of white LEDs. In order to manufacture warm white LEDs with a CCT of 2500-3200K, it is necessary to mix (Sr,Ca)S:Eu ²⁺ , (Ba,Sr,Ca) ₂ Si ₅ N ₈ into YAG:Ce ³⁺ yellow phosphor :Eu ²⁺ , CaAlSiN ₃ :Eu ²⁺ and other sulfide and nitride matrix red phosphors that can be excited by blue light. Although this method can make up for the deficiency of YAG:Ce ³⁺ phosphor to a certain extent, it also brings new problems: firstly, sulfide and nitride have their own shortcomings, such as the poor chemical stability of the former, And it is harmful to the environment, and the preparation conditions of the latter are very harsh and the cost is very high; secondly, due to the reabsorption of emission energy between different phosphors, the luminescent color is unstable. Therefore, the development of new yellow phosphors for LEDs has become a hot topic.

In the design and selection process of new yellow phosphors, the garnet structure matrix that can generate a strong crystal field has been paid attention to. In 2006, Setlur et al. reported the luminescent properties of phosphors Lu ₂ CaMg ₂ Si ₃ O ₁₂ :Ce ³⁺ whose main phase activated by Ce ³⁺ was garnet structure. The luminescent properties of Lu ₂ CaMg ₂ Si ₃ O ₁₂ :Ce ³⁺ phosphors indicate that garnet-structured silicate is an excellent matrix for potential yellow light materials. So far, there are few silicates with garnet structure that have been reported by the solid-state reaction method. In addition to Ce ³⁺ activated Lu ₂ CaMg ₂ Si ₃ O ₁₂ , only Ce ³⁺ activated Ca ₃ Sc ₂ Si ₃ O ₁₂ . The main emission peak of Lu ₂ CaMg ₂ Si ₃ O ₁₂ :Ce ³⁺ phosphor is at 605nm. The quantum efficiency is 60%. Lu ₂ CaMg ₂ Si ₃ O ₁₂ :Ce ³⁺ is packaged with the blue LED chip, and the obtained white light has a color temperature of 3500K, but its color rendering is relatively low, only 76, which easily leads to color distortion. However, the main peak of Ca ₃ Sc ₂ Si ₃ O ₁₂ :Ce ³⁺ phosphor is at 505nm, which emits green light and cannot be directly combined with a blue light chip to emit white light. It needs to be combined with a red light phosphor to obtain white light.

Contents of the invention

In view of the above-mentioned problems existing in the prior art, the object of the present invention is to provide a novel emission wavelength with respect to YAG:Ce ³⁺ obvious red-shift, white light LED with low preparation temperature garnet structure phosphor powder activated by cerium ions and its preparation method.

The technical scheme adopted in the present invention is:

A Ce ³⁺ activated garnet structure phosphor, characterized in that the chemical expression of the phosphor is:

Mg _2-a A _a Y _2-xb B _b M ₂ N ₂ O ₁₂ :xCe ³⁺

In the formula: A is a combination of one or more of Ba, Sr, and Ca, B is a combination of one or more of Gd, La, and Sc, and M is one or a combination of Al and Ga. A combination of any proportion, N is one of Si and Ge or a combination of two in any proportion, x, a, b are their respective mole fractions, and their value ranges are: 0.01≤x≤0.12, 0≤a ≤0.2, 0≤b≤0.2.

Further, it is preferable that 0.03≦x≦0.09.

In the phosphor powder provided by the present invention, each of a and b can be 0, that is, no element A or element B is doped. When a and b are 0 at the same time, it means that A and B are not doped in the phosphor at the same time.

Furthermore, A is preferably Ba, Sr or a mixture of Ba, Sr, and Ca substances in a ratio of 1:0.5 to 1.5:0.5 to 1.5.

B is preferably La or Gd.

M is preferably Al, Ga or a combination in which the amount ratio of Al and Ga is 1:0.1-10.

N is preferably Si, Ge or a combination in which the amount ratio of Si and Ge is 1:0.1-10.

Further, it is preferable that the most basic structural formula of the phosphor powder in the present invention is Mg ₂ Y _2-x M ₂ N ₂ O ₁₂ : xCe ³⁺ , doping A and B ions and changing the composition of M and N can adjust the performance of the phosphor powder .

The present invention also provides a method for preparing the fluorescent powder, which can be prepared by a high-temperature solid-phase method. The method is as follows: according to the chemical expression of the fluorescent powder: Mg _2-a A _a Y _2-xb B _b M ₂ N ₂ O ₁₂ :xCe ³⁺ , where: A is one or a combination of two or more of Ba, Sr, and Ca, B is one or a combination of two or more of Gd, La, and Sc, and M is Al, One of Ga or a combination of two in any proportion, N is one of Si and Ge or a combination of two in any proportion, x, a, b are their respective mole fractions, and their value range is: 0.01≤ x≤0.12, 0≤a≤0.2, 0≤b≤0.2;

Using compounds containing each element in the chemical expression as raw materials, weigh the corresponding raw materials according to the molar ratio of each element in the above chemical expression, directly grind and mix the precursor with solid powder, and put the precursor into In a reducing atmosphere, heat up to 900°C to 1350°C for 1 to 5 times (preferably 1 to 2 times) to obtain the final calcined product; the heating rate is usually 5°C/min to 20°C/min. The primary calcination time is 5 to 24 hours, and the grinding process is carried out after cooling to room temperature between every two calcinations, and the final calcination is carried out under a reducing atmosphere, which is a nitrogen gas mixture containing 5-10v% hydrogen or containing 5-10v% carbon monoxide mixed with nitrogen gas, the final roasted product is crushed, ground, particle size classified, washed to remove impurities, and dried to obtain the Ce ³⁺ activated garnet structure phosphor.

The grinding of the present invention can be carried out in an agate mortar or a ball mill.

The particle size classification method is one or more of sedimentation method, sieving method or air flow method.

The final roasted product is crushed, ground, and particle size classified, which means that the particle size of the sintered body is ground by ball milling after manual crushing, and classified by sedimentation method, sieving method or air flow method, and the particle size is 3 to 10. Micron solid powder.

The washing to remove impurities and drying is to wash with water and methanol in sequence, filter to separate the solid phase, and dry at 100°C to 115°C.

The raw material of the phosphor is a compound containing each element in the chemical expression, and the compound containing the element can be selected as the raw material according to the various elements contained in the chemical expression. Specifically, the raw materials of the phosphor powder include compounds containing Mg, Y, M, N, and Ce respectively, and when the phosphor powder is doped with A or B, the raw materials also include compounds containing A or B respectively.

More specifically, the compound containing Mg, Ca, Sr or Ba is the corresponding oxide, carbonate, hydroxide or nitrate containing Mg, Ca, Sr or Ba; the compound containing Al is aluminum oxide, In aluminum hydroxide or aluminum nitrate; the compound containing Y or Ce is the corresponding oxide or nitrate containing Y or Ce; the compound containing Si is silicon dioxide or sodium silicate; the compound containing Ge, Gd, Ga or Sc The compounds are respective oxides containing Ge, Gd, Ga or Sc; the compounds containing La are lanthanum oxide, lanthanum nitrate, lanthanum hydroxide or lanthanum carbonate.

The Ce ³⁺ activated garnet structure fluorescent powder provided by the invention is a fluorescent powder that emits orange-yellow light when excited by blue light.

The Ce ³⁺ activated garnet structure phosphor powder of the present invention can be applied in white light LEDs.

Specifically, the application method is that Ce ³⁺ activated garnet structure phosphor powder is packaged with a blue LED diode chip to prepare a white LED.

Compared with the prior art, the beneficial effects of the present invention are as follows:

1) The present invention adopts the above-mentioned technical scheme, and the garnet structure phosphor obtained by adding Ce ³⁺ as an activator is a new type of material suitable for the application of white LEDs excited by blue LED chips, and its sintering temperature is higher than that of synthetic YAG:Ce (T=1400～1600℃) low, energy saving.

2) The fluorescent powder of the present invention can absorb blue light from 450nm to 500nm, so it can be effectively excited by InGaN blue light with a wavelength of 450nm to 470nm, and the emission spectrum ranges from 500nm to 750nm. More specifically, under the excitation of blue light with a wavelength of 460nm in the present invention, the emission wavelength range of the garnet structure phosphor is 500 to 750nm, and its main peak is around 601nm, which is about 60nm red shifted compared with YAG:Ce ³⁺ . The GaN-based blue LED basic light source with a wavelength of 460nm to 470nm is used to excite, thereby being excited to emit orange light, and the remaining blue light and orange light can be mixed to produce white light. Compared with YAG:Ce ³⁺ , the color rendering index of the present invention is higher High, lower color temperature.

Description of drawings

Fig. 1 is the excitation spectrum and emission spectrum diagram of the Ce ^{3+ -doped} garnet structure phosphor prepared in Example 1 of the present invention.

In the figure: the solid line is the excitation spectrum, and the dotted line is the emission spectrum.

Fig. 2 is an X-ray diffraction spectrum of the Ce ^{3+ -doped} garnet structure phosphor prepared in Example 1 of the present invention.

detailed description

The solutions of the present invention will be further described below with specific examples, but the protection scope of the present invention is not limited thereto.

Example 1:

Preparation of Mg ₂ Y _1.97 Al ₂ Si ₂ O ₁₂ :0.03Ce ³⁺ phosphor.

The preparation method is as follows:

Weigh respectively 0.4030 gram of magnesium oxide (MgO), 1.1121 gram of diyttrium trioxide (Y ₂ O ₃ ), 0.6008 gram of silicon dioxide (SiO ₂ ), 0.0258 gram of cerium oxide (CeO ₂ ), 0.5098 gram of aluminum oxide ( Al ₂ O ₃ ), the purity of the above raw materials is above 99%. Grind the above raw material mixture in an agate mortar evenly, put it into a corundum crucible, use nitrogen mixture containing 5v% hydrogen as reducing atmosphere, heat up at 10°C/min, bake at 900°C for 8 hours, and cool naturally After reaching room temperature, the pre-fired sample was taken out and ground again, then raised to the required temperature (1350°C) at a rate of 10°C/min, kept at a constant temperature for 8 hours, and cooled to room temperature. After the obtained sintered product is crushed, it is finely ground with a ball mill and sieved to obtain a solid powder with a particle size of 3 to 10 microns. After washing with deionized water (30ml) and methanol (20ml) successively, the fluorescent powder is separated by filtration. The fluorescent powder product can be obtained by drying in an oven at ℃ for 8 hours. The emission wavelength of the fluorescent powder is between 500nm and 750nm under the excitation of 460nm blue light, and the main emission wavelength is 599nm. The color coordinates are (x=0.500, y=0.485).

The excitation spectrum and the emission spectrum spectrogram of the garnet structure phosphor powder ^doped with Ce that the present embodiment makes are as shown in accompanying drawing 1, and wherein solid line part is excitation spectrum spectrogram (λem=599nm), and dotted line part is emission Spectrogram (λex=460nm).

It can be seen from FIG. 1 that the emission wavelength of the phosphor is between 500nm and 750nm under the excitation of 460nm blue light, and the main emission wavelengths are respectively 599nm. The measured color coordinates are (x=0.500, y=0.485). The phosphor can be excited by blue light from 400nm to 500nm, and is a new type of phosphor suitable for white LED applications excited by blue LED chips.

Fig. 2 is the X-ray diffraction spectrogram of the ^Ce3+-doped phosphor with garnet structure prepared in Example 1. It can be seen from Fig. 2 that the phosphor obtained has a garnet structure. Example 2:

Preparation of Mg _1.8 Ba _0.2 Y _1.97 Al ₂ Si ₂ O ₁₂ :0.03Ce ³⁺ phosphor.

The preparation method is as follows:

Weigh 0.3627 grams of magnesium oxide (MgO), 0.1974 grams of barium carbonate (BaCO ₃ ), 1.1121 grams of diyttrium trioxide (Y ₂ O ₃ ), 0.6008 grams of silicon dioxide (SiO ₂ ), 0.0258 grams of cerium oxide (CeO ₂ ), 0.5098 grams of aluminum trioxide (Al ₂ O ₃ ), and the purity of the above raw materials is above 99%. Grind the above raw material mixture evenly in an agate mortar to obtain a precursor, place the obtained precursor in a corundum crucible, use a 5v% hydrogen-nitrogen mixture as a reducing atmosphere, and heat it in a muffle furnace at 10°C/min The speed was raised to 900°C, and the temperature was kept constant for 8 hours. Take out the pre-fired sample and grind it again, then raise it to the required temperature (1340°C) at a speed of 10°C/min, keep the temperature constant for 12 hours, and cool to room temperature. The solid powder with a particle size of 3-10 microns was obtained by the method, washed with deionized water (30ml) and methanol (20ml) in sequence, filtered to separate the phosphor, and dried in an oven at 110°C for 12 hours to obtain the phosphor product. Under the excitation of 460nm blue light, the phosphor powder has a main emission peak at 601nm and an emission wavelength between 500nm and 750nm. The color coordinates are (x=0.523, y=0.468). The phosphor can be excited by blue light from 400nm to 500nm, and is a new type of phosphor suitable for white LED applications excited by blue LED chips. The X-ray diffraction spectrum of the fluorescent powder is similar to that shown in Figure 2, which is a garnet structure. Example 3:

Preparation of Mg _1.85 Sr _0.05 Ca _0.05 Ba _0.05 Y _1.94 Al ₂ Si ₂ O ₁₂ :0.06Ce ³⁺ phosphor.

The preparation method is as follows:

Weigh 0.3728 grams of magnesium oxide (MgO), 0.0494 grams of barium carbonate (BaCO ₃ ), 0.0369 grams of strontium carbonate (SrCO ₃ ), 0.0250 grams of calcium carbonate (CaCO ₃ ), 3.7152 grams of yttrium nitrate hexahydrate (Y(NO ₃ ) 3.6H ₂ O), 0.6008 grams of silicon dioxide (SiO ₂ ), 0.0516 grams of cerium oxide (CeO _{2 )} , 0.3900 grams of aluminum hydroxide (Al(OH) ₃ ), the purity of the above raw materials is above 99%. Grind the above-mentioned raw material mixture in an agate mortar evenly, put it into a corundum crucible, use a nitrogen mixture containing 5v% hydrogen as a reducing atmosphere, and raise the temperature to 900°C at a rate of 10°C/min, and then keep the temperature for 8 hours , cooled to room temperature. Take out the pre-fired sample and grind it again, then raise it to the required temperature (1350°C) at a speed of 5°C/min, keep the temperature constant for 8 hours, and cool to room temperature. The solid powder with a particle size of 3-10 microns was obtained by the method, washed with deionized water (30ml) and methanol (20ml) in sequence, filtered to separate the phosphor, and dried in an oven at 110°C for 10 hours to obtain the phosphor product. The emission wavelength of the fluorescent powder is between 500nm and 750nm under the excitation of 460nm blue light, and the main emission wavelength is 602nm. The color coordinates are (x=0.519, y=0.472). The phosphor can be excited by blue light from 400nm to 500nm, and is a new type of phosphor suitable for white LED applications excited by blue LED chips. The X-ray diffraction spectrum of the fluorescent powder is similar to that shown in Figure 2, which is a garnet structure.

Example 4:

Preparation of Mg ₂ Y _1.97 Ga ₂ Si ₂ O ₁₂ :0.03Ce ³⁺ phosphor.

The preparation method is as follows:

Weigh respectively 0.4030 gram of magnesium oxide (MgO), 1.8863 gram of yttrium nitrate hexahydrate (Y(NO ₃ ) ₃ 6H ₂ O), 0.6008 gram of silicon dioxide (SiO ₂ ), 0.0651 gram of cerium nitrate hexahydrate (Ce(NO ₃ ) 3.6H ₂ O), 0.9372 grams of gallium oxide (Ga ₂ O _{3 )} , the purity of the above raw materials is above 99%. Grind the above-mentioned raw material mixture in an agate mortar evenly, put it into a corundum crucible, use a nitrogen gas mixture containing 5v% carbon monoxide as a reducing atmosphere, heat up at a rate of 10°C/min, bake at 900°C for 8 hours, and cool to At room temperature, take out the pre-fired sample and grind it again, then raise it to the required temperature (1250°C) at a rate of 10°C/min, keep the temperature for 8h, cool to room temperature, grind it again, and then increase it at a rate of 10°C/min to The desired temperature (1300°C) was kept constant for 10 hours. After the obtained sintered product is crushed, it is finely ground with a ball mill and sieved to obtain a solid powder with a particle size of 3 to 10 microns. It is washed twice with deionized water (30ml) and methanol (20ml) in turn, and finally filtered to separate the fluorescent powder. powder, and dried in an oven at 110°C for 15 hours to obtain a phosphor product. The fluorescent powder emits light with a wavelength between 500nm and 750nm, the main emission wavelength is 610nm, and the color coordinates are (x=0.519, y=0.471). The phosphor can be excited by blue light from 400nm to 500nm, and is a new type of phosphor suitable for white LED applications excited by blue LED chips. The X-ray diffraction spectrum of the fluorescent powder is similar to that shown in Figure 2, which is a garnet structure.

Example 5:

Preparation of Mg ₂ Y _1.91 Al ₂ Ge ₂ O ₁₂ :0.09Ce ³⁺ phosphor.

The preparation method is as follows:

Weigh respectively 0.4030 gram of magnesium oxide (MgO), 1.0782 gram of diyttrium trioxide (Y ₂ O ₃ ), 0.0774 gram of cerium oxide (CeO ₂ ), 0.5098 gram of aluminum trioxide (Al ₂ O ₃ ), 1.0464 gram of germanium oxide ( GeO ₂ ), the purity of the above raw materials is above 99%. Grind the above raw material mixture evenly in an agate mortar, put it into a corundum crucible, use a nitrogen mixture containing 5v% hydrogen as a reducing atmosphere, heat up at a rate of 10°C/min, bake at 900°C for 8 hours, and cool to room temperature . Take out the pre-fired sample and grind it again, then raise it to the required temperature (1300°C) at a speed of 10°C/min, keep the temperature constant for 15 hours, and cool to room temperature. A solid powder fluorescent powder with a particle size of 3-10 microns is obtained. The emission wavelength of the fluorescent powder is between 500nm and 750nm, the main emission wavelength is 608nm, and the color coordinates are (x=0.509, y=0.481). The phosphor can be excited by blue light from 400nm to 500nm, and is a new type of phosphor suitable for white LED applications excited by blue LED chips. The X-ray diffraction spectrum of the fluorescent powder is similar to that shown in Figure 2, which is a garnet structure.

Embodiment 6:

Preparation of Mg ₂ Y _1.88 La _0.05 Al ₂ Si ₂ O ₁₂ :0.07Ce ³⁺ phosphor.

The preparation method is as follows:

Weigh respectively 0.4030 gram of magnesium oxide (MgO), 3.6003 gram of yttrium nitrate hexahydrate (Y(NO ₃ ) ₃ 6H ₂ O), 0.6008 gram of silicon dioxide (SiO ₂ ), 0.0602 gram of cerium oxide (CeO ₂ ), 0.5098 gram of aluminum trioxide (Al ₂ O ₃ ), and 0.0407 gram of dilanthanum trioxide (La ₂ O ₃ ), the purity of the above raw materials is above 99%. Grind the above-mentioned raw material mixture in an agate mortar evenly, put it into a corundum crucible, use a nitrogen mixture containing 5v% hydrogen as a reducing atmosphere, heat up at a rate of 10°C/min, bake at 900°C for 8 hours, and cool to At room temperature, the pre-fired sample was taken out and ground again, and then raised to the required temperature (1350°C) at a rate of 10°C/min, kept at a constant temperature for 8h, and cooled to room temperature. After the obtained sintered product is crushed, it is finely ground with a ball mill and sieved to obtain a solid powder with a particle size of 3 to 10 microns. It is washed twice with deionized water (30ml) and methanol (20ml) in turn, and finally filtered to separate the fluorescent powder. powder, and dried in an oven at 100°C for 20 hours to obtain the phosphor product. The emission wavelength of the fluorescent powder is between 500nm and 750nm under the excitation of 460nm blue light, the main emission wavelength is 601nm, and the color coordinates are (x=0.508, y=0.482). The phosphor can be excited by blue light from 400nm to 500nm, and is a new type of phosphor suitable for white LED applications excited by blue LED chips. The X-ray diffraction spectrum of the fluorescent powder is similar to that shown in Figure 2, which is a garnet structure.

Example 7

Preparation of Mg ₂ Y _1.87 La _0.1 Al ₂ Si _1.8 Ge ₀ . ₂ O ₁₂ :0.03Ce ³⁺ phosphor.

The preparation method is as follows:

Weigh respectively 0.4030 gram of magnesia (MgO), 1.7906 gram of diyttrium trioxide (Y ₂ O ₃ ), 0.5407 gram of silicon dioxide (SiO ₂ ), 0.0258 gram of cerium oxide (CeO ₂ ), 0.5098 gram of aluminum trioxide (Al ₂ O ₃ ), 0.0814 grams of lanthanum trioxide (La ₂ O ₃ ), and 0.1046 grams of germanium oxide (GeO ₂ ), all of which have a purity of more than 99%. Grind the above raw material mixture evenly in an agate mortar, put it into a corundum crucible, use a nitrogen mixture containing 5v% carbon monoxide as a reducing atmosphere, heat up at a rate of 5°C/min, bake at 900°C for 8 hours, and cool to room temperature , take out the pre-fired sample and grind it again, then raise it to the required temperature (1320°C) at a rate of 5°C/min, keep the temperature constant for 15h, and cool to room temperature. Get the sintered product and grind it to raise the temperature again, and roast it twice according to the above-mentioned roasting conditions. The obtained sintered product is ground with a ball mill after crushing, and the solid powder with a particle size of 3 to 10 microns is obtained by the sedimentation method, and deionized water (30ml) and Methanol (20ml) was washed twice each, and finally the fluorescent powder was separated by filtration, and dried in an oven at 110° C. for 20 hours to obtain the fluorescent powder product. The emission wavelength of the fluorescent powder is between 500nm and 750nm under the excitation of 460nm blue light, and the main emission wavelength is 604nm, covering the entire range of visible light. The color coordinates are (x=0.508, y=0.482). The phosphor can be excited by blue light from 400nm to 500nm, and is a new type of phosphor suitable for white LED applications excited by blue LED chips. The X-ray diffraction spectrum of the fluorescent powder is similar to that shown in Figure 2, which is a garnet structure.

Embodiment 8:

Preparation of Mg ₂ Y _1.90 Gd _0.05 Al ₂ Si ₂ O ₁₂ :0.05Ce ³⁺ phosphor.

The preparation method is as follows:

Weigh respectively 0.4030 gram of magnesia (MgO), 1.0726 gram of diyttrium trioxide (Y ₂ O ₃ ), 0.6008 gram of silicon dioxide (SiO ₂ ), 0.0430 gram of cerium oxide (CeO ₂ ), 0.5098 gram of aluminum trioxide (Al ₂ O ₃ ), 0.0453 g of gadolinium trioxide (Gd ₂ O ₃ ), the purity of the above raw materials is above 99%. Grind the above-mentioned raw material mixture in an agate mortar evenly, put it into a corundum crucible, use a nitrogen gas mixture containing 5v% carbon monoxide as a reducing atmosphere, heat up at a rate of 10°C/min, bake at 900°C for 8 hours, and cool to At room temperature, the pre-fired sample was taken out and ground again, then raised to the required temperature (1350°C) at a rate of 5°C/min, kept at a constant temperature for 8 hours, and cooled to room temperature. After the sintered product is crushed, it is finely ground with a ball mill, and the solid powder with a particle size of 3 to 10 microns is obtained by the sedimentation method. It is washed twice with deionized water (30ml) and methanol (20ml) in turn, and finally filtered to separate the phosphor. , drying in an oven at 110°C for 20 hours to obtain the phosphor product. The emission wavelength of the fluorescent powder is between 500nm and 750nm under the excitation of 460nm blue light, and the main emission wavelength is 592nm, covering the entire range of visible light. The color coordinates are (x=0.481, y=0.496). The phosphor can be excited by blue light from 400nm to 500nm, and is a new type of phosphor suitable for white LED applications excited by blue LED chips. The X-ray diffraction spectrum of the fluorescent powder is similar to that shown in Figure 2, which is a garnet structure.

Embodiment 9:

Preparation of Mg _1.8 Ba _0.2 Y _1.87 Gd _0.1 Al ₂ Si ₂ O ₁₂ :0.03Ce ³⁺ phosphor.

The preparation method is as follows:

Weigh respectively 0.3627 grams of magnesium oxide (MgO), 0.1974 grams of barium carbonate (BaCO3), 1.0557 grams of diyttrium trioxide (Y ₂ O ₃ ), 0.6008 grams of silicon dioxide (SiO ₂ ), 0.0258 grams of cerium oxide (CeO ₂ ) , 0.5098 grams of aluminum trioxide (Al ₂ O ₃ ), and 0.0906 grams of gadolinium trioxide (Gd ₂ O ₃ ), the purity of the above raw materials is above 99%. Grind the above raw material mixture evenly in an agate mortar, put it into a corundum crucible, use a nitrogen mixture containing 5v% hydrogen as a reducing atmosphere, heat up at a rate of 10°C/min, bake at 900°C for 8 hours, and cool to room temperature . Take out the pre-fired sample and grind it again, then raise it to the required temperature (1350°C) at a speed of 10°C/min, keep the temperature for 8 hours, grind the burnt sample again, and then raise it to the desired temperature at a speed of 10°C/min Required temperature (1350°C), constant temperature for 8 hours, cooling to room temperature, the obtained sintered product is crushed, finely ground with a ball mill, and sieved to obtain a solid powder phosphor with a particle size of 3-10 microns. The emission wavelength of the phosphor is between 500nm and 750nm, the main emission wavelength is 608nm, and the color coordinates are (x=0.481, y=0.496 color rendering index Ra=91. The phosphor can be excited by blue light from 400nm to 500nm, It is a new type of phosphor suitable for the application of white LEDs excited by blue LED chips. The X-ray diffraction spectrum of the phosphor is similar to that in Figure 2, which is a garnet structure.

Example 10:

Preparation of Mg _1.85 Sr _0.05 Ca _0.05 Ba _0.05 Y _1.77 Gd _0.2 Al ₂ Si ₂ O ₁₂ :0.03Ce ³⁺ phosphor powder.

The preparation method is as follows:

Weigh 0.3729 grams of magnesium oxide (MgO), 0.0494 grams of barium carbonate (BaCO3), 0.0369 grams of strontium carbonate ( _SrCO3 ), 0.0250 grams of calcium carbonate (CaCO3), 2.9914 grams of yttrium nitrate hexahydrate (Y( _{NO3 ) 3} 6H ₂ O), 0.6008 grams of silicon dioxide (SiO ₂ ), 0.0258 grams of cerium oxide (CeO ₂ ), 0.5098 grams of aluminum trioxide (Al ₂ O ₃ ), 0.1812 grams of gadolinium trioxide (Gd ₂ O ₃ ), The purity of the above raw materials is above 99%. Grind the above raw material mixture evenly in an agate mortar, put it into a corundum crucible, use a nitrogen mixture containing 5v% hydrogen as a reducing atmosphere, heat up at a rate of 10°C/min, bake at 900°C for 8 hours, and cool to room temperature . Take out the pre-fired sample and grind it again, then raise it to the required temperature (1340°C) at a speed of 5°C/min, keep the temperature constant for 10 hours, and cool to room temperature. A solid powder fluorescent powder with a particle size of 3-10 microns is obtained. The emission wavelength of the fluorescent powder is between 500nm and 750nm, the main emission wavelength is 608nm, and the color coordinates are (x=0.481, y=0.495). The phosphor can be excited by blue light from 400nm to 500nm, and is a new type of phosphor suitable for white LED applications excited by blue LED chips. The X-ray diffraction spectrum of the fluorescent powder is similar to that shown in Figure 2, which is a garnet structure.

Example 11:

Preparation of Mg _1.85 Sr _0.05 Ca _0.05 Ba _0.05 Y _1.77 Gd _0.2 Al ₂ Ge ₂ O ₁₂ :0.03Ce ³⁺ phosphor powder.

The preparation method is as follows:

Weigh 0.3729 grams of magnesium oxide (MgO), 0.0494 grams of barium carbonate (BaCO ₃ ), 0.0369 grams of strontium carbonate (SrCO ₃ ), 0.0250 grams of calcium carbonate (CaCO ₃ ), 2.9914 grams of yttrium nitrate hexahydrate (Y(NO ₃ ) 3.6H ₂ O), 0.0258 grams of cerium oxide (CeO ₂ ), 0.5098 grams of aluminum trioxide (Al ₂ O ₃ ), 0.1812 grams of gadolinium trioxide (Gd ₂ O _{3 )} , 1.0464 grams of germanium oxide (GeO ₂ ), The purity of the above raw materials is above 99%. Grind the above raw material mixture evenly in an agate mortar, put it into a corundum crucible, use a nitrogen mixture containing 5v% hydrogen as a reducing atmosphere, heat up at a rate of 10°C/min, bake at 900°C for 8 hours, and cool to room temperature . Take out the pre-fired sample and grind it again, then raise it to the required temperature (1310°C) at a speed of 5°C/min, keep the temperature for 10 hours, and cool it to room temperature. A solid powder fluorescent powder with a particle size of 3-10 microns is obtained. The emission wavelength of the fluorescent powder is between 500nm and 750nm, the main emission wavelength is 608nm, and the color coordinates are (x=0.481, y=0.495). The phosphor can be excited by blue light from 400nm to 500nm, and is a new type of phosphor suitable for white LED applications excited by blue LED chips. The X-ray diffraction spectrum of the fluorescent powder is similar to that shown in Figure 2, which is a garnet structure.

Claims (5)

1. a Ce³⁺The garnet structure fluorescent material activated, it is characterised in that the chemical expression of described fluorescent material is:

Mg_2-aA_aY_2-x-bB_bM₂N₂O₁₂:xCe³⁺

In formula: A is one or more the combination in Ba, Sr, Ca, B is one or more the combination in Gd, La, Sc, M is the combination of one or both arbitrary proportions in Al, Ga, N is the combination of one or both arbitrary proportions in Si, Ge, x, a, b are respective molar fraction, their span is: 0.01≤x≤0.12,0≤a≤0.2,0≤b≤0.2.

2. fluorescent material as claimed in claim 1, it is characterised in that 0.03≤x≤0.09.

3. Ce as claimed in claim 1³⁺The preparation method of the garnet structure fluorescent material activated, it is characterised in that described method is: the chemical expression according to fluorescent material: Mg_2-aA_aY_2-x-bB_bM₂N₂O₁₂:xCe³⁺In formula: A is one or more the combination in Ba, Sr, Ca, B is one or more the combination in Gd, La, Sc, M is the combination of one or both arbitrary proportions in Al, Ga, N is the combination of one or both arbitrary proportions in Si, Ge, and x, a, b are respective molar fraction, and their span is: 0.01≤x≤0.12,0≤a≤0.2,0≤b≤0.2;

Taking respectively containing the compound of each element in chemical expression as raw material, corresponding described raw material is taken by the molar ratio of element each in above-mentioned chemical expression, directly it is ground to obtain presoma with pressed powder, presoma is placed in reducing atmosphere, it is warming up to 900 DEG C～1350 DEG C roasting temperatures 1～5 time, obtains final product of roasting; Each roasting time is 5～24 hours, between every twice roasting, cool to room temperature carries out milled processed, last roasting carries out under reducing atmosphere, described reducing atmosphere is the nitrogen mixture containing 5-10v% hydrogen or the nitrogen mixture containing 5-10v% carbon monoxide, final product of roasting is through broken, levigate, size grading, and namely obtains described Ce through washing impurity-removing, oven dry³⁺The garnet structure fluorescent material activated.

4. Ce as claimed in claim 1 or 2³⁺The application of the garnet structure fluorescent material activated in white light LEDs.

5. apply as claimed in claim 4, it is characterised in that the method for described application is, Ce³⁺The garnet structure fluorescent material activated and the encapsulation of blue-ray LED diode chip for backlight unit, for the preparation of white light LEDs.