Eu-doped fluorescent powder, preparation method thereof and luminescence performance regulation method

Abstract

The application provides a Eu-doped fluorescent powder and a preparation method and a luminescent performance regulating method thereof. n O m :0.03Eu 2+ , M=Mg or Ca, 0.9<=n<=1.3, 3.75<=m<=4.75. The application realizes the regulation of the luminescent performance of the fluorescent powder by changing the relative content of phosphorus in the composition of the fluorescent powder by changing the amount of ammonium dihydrogen phosphate, realizes the regulation of the luminescent performance of the fluorescent powder by replacing calcium carbonate with a magnesium source or replacing the magnesium source with calcium carbonate, realizes the regulation of the luminescent performance of the fluorescent powder by changing the cooling mode after high-temperature calcination, realizes the regulation of the luminescent performance of the fluorescent powder by changing the high-temperature calcination temperature, and realizes the regulation of the luminescent performance of the fluorescent powder by changing the type of the magnesium source.

Description

Technical Field

[0001] The present invention relates to the technical field of phosphors, and in particular to a Eu-doped phosphor and a preparation method and a luminescence performance control method thereof. Background Art

[0002] Light-emitting diodes (LEDs) are a commonly used light-emitting device that is widely used in lighting, display, plant lighting, medical and other fields. LED light-emitting devices are mainly prepared by combining semiconductor chips and phosphors. As the light conversion material of LED devices, the luminescence performance of phosphors directly affects the luminescence performance of LED devices. The luminescence performance of phosphors is related to the number of emission bands, the position of emission bands, the width of emission bands, the relative intensity ratio of each emission band, etc. Different application fields have different requirements for the luminescence performance of phosphors. Therefore, it is very important to adjust the emission spectrum of phosphors. At present, the regulation of phosphor luminescence performance is mainly achieved by changing the composition of the phosphor matrix, the concentration and type of doped luminescent ions, and further research is needed on the strategy of regulating phosphor luminescence performance.

[0003] Chinese patent document CN101942301A discloses a phosphate red phosphor for light-emitting diodes and its preparation method, which has the following chemical formula: AB 1-x PO4:xEu 3+ or A 1+y B 1-x-y PO4:xEu 3+ , where element A is Li + , Na + and K + One or more alkali metal ions; element B is Mg 2+ , Ca 2+ , Sr 2+ and Ba 2+ One or more alkaline earth metal ions, and 0 <x≦1,0≦y<1。该发明荧光粉发光效率高,稳定性好,达到增强荧光粉发光强度的目的。该发明公开的荧光粉发光中心为Eu 3+ , and does not involve the regulation of the luminescence properties of phosphors. Summary of the Invention

[0004] In response to the shortcomings of the prior art, the present invention provides a Eu-doped phosphor, a preparation method thereof, and a method for regulating luminescence performance. The present invention regulates the luminescence performance of the phosphor by changing the relative content of phosphorus in the phosphor composition by varying the amount of ammonium dihydrogen phosphate used; regulates the luminescence performance of the phosphor by replacing calcium carbonate with a magnesium source or vice versa; regulates the luminescence performance of the phosphor by changing the cooling method after high-temperature calcination; regulates the luminescence performance of the phosphor by varying the high-temperature calcination temperature; and regulates the luminescence performance of the phosphor by varying the type of magnesium source.

[0005] The present invention is achieved through the following technical solutions:

[0006] An Eu-doped phosphor having the following molar composition: NaMP n O m :0.03Eu 2+ , M=Mg or Ca, 0.9≤n≤1.3, 3.75≤m≤4.75.

[0007] The preparation method of the Eu-doped phosphor comprises the following steps:

[0008] The raw materials of sodium carbonate, calcium carbonate or magnesium source, ammonium dihydrogen phosphate and europium oxide are ground and mixed uniformly, and pre-fired in air atmosphere; after pre-fired, they are ground, calcined at high temperature in reducing atmosphere, cooled, and ground again to obtain Eu-doped phosphor.

[0009] According to the present invention, preferably, the magnesium source is basic magnesium carbonate or magnesium oxide.

[0010] According to the present invention, preferably, the pre-firing temperature is 350-450° C., the pre-firing time is 3-5 h, and the heating rate is 4-6° C. / min.

[0011] According to the present invention, preferably, the high-temperature calcination temperature is 1000-1300° C., the holding time is 3-5 hours, and the heating rate is 4-6° C. / min.

[0012] According to the present invention, preferably, the cooling method is quenching or furnace cooling; the quenching cooling method is as follows: when the furnace temperature naturally drops to 850-900°C, the calcined sample is taken out and cooled at room temperature until it cools to room temperature; the furnace cooling method is as follows: naturally cool to room temperature in the furnace.

[0013] According to the present invention, preferably, the high-temperature calcination method is as follows: the powder obtained by pre-burning and grinding is placed in a small crucible, and the small crucible is placed in a large crucible, carbon powder is placed between the large crucible and the small crucible, and the mouth of the large crucible is covered with a lid to form a relatively closed space; then the large crucible is placed in a muffle furnace for high-temperature calcination. During the high-temperature solid-phase reaction of the sample after pre-burning and grinding, the carbon powder and the residual oxygen in the large crucible generate carbon monoxide, forming a reducing atmosphere, and the sample after pre-burning and grinding is sintered under this reducing atmosphere. Since the mouth of the large crucible is covered with a lid, the outside air cannot enter the large crucible, so that the carbon powder and the residual oxygen in the large crucible can generate more carbon monoxide, and the generated carbon monoxide can also be prevented from overflowing, so that the material can be sintered under a reducing atmosphere.

[0014] According to the present invention, preferably, the luminescence performance of the phosphor is regulated by changing the relative content of phosphor in the phosphor composition by changing the amount of ammonium dihydrogen phosphate; the luminescence performance of the phosphor is regulated by replacing calcium carbonate with a magnesium source or vice versa; the luminescence performance of the phosphor is regulated by changing the cooling method after high-temperature calcination; the luminescence performance of the phosphor is regulated by changing the high-temperature calcination temperature; and the luminescence performance of the phosphor is regulated by changing the type of magnesium source.

[0015] The method for regulating the luminescence performance of the Eu-doped phosphor comprises the following steps:

[0016] (1) Grind and mix the raw materials of sodium carbonate, calcium carbonate or magnesium source, ammonium dihydrogen phosphate, and europium oxide, and pre-sinter them at 4-6°C / min to 350-450°C in an air atmosphere for 3-5 hours; grind the powder obtained after pre-sintering, put the powder into a small crucible, put the small crucible into a large crucible, place carbon powder between the large crucible and the small crucible, cover the mouth of the large crucible with a lid to form a relatively closed space, and then place the large crucible in a muffle furnace and heat it to 1000-1300°C at 4-6°C / min for high-temperature calcination in a reducing atmosphere for 3-5 hours, cool, and grind again to obtain Eu-doped phosphor;

[0017] Wherein, the magnesium source is basic magnesium carbonate or magnesium oxide;

[0018] (2) By changing the amount of ammonium dihydrogen phosphate, the relative content of phosphor in the composition of the phosphor is changed, thereby achieving the regulation of the luminescence performance of the phosphor; by replacing calcium carbonate with a magnesium source or replacing the magnesium source with calcium carbonate, the luminescence performance of the phosphor is regulated; by changing the cooling method after high-temperature calcination, the luminescence performance of the phosphor is regulated; by changing the high-temperature calcination temperature, the luminescence performance of the phosphor is regulated; by changing the type of magnesium source, the luminescence performance of the phosphor is regulated.

[0019] According to the present invention, preferably, the cooling method is quenching or furnace cooling; the quenching cooling method is as follows: when the furnace temperature naturally drops to 850-900°C, the calcined sample is taken out and cooled at room temperature until it cools to room temperature; the furnace cooling method is as follows: naturally cool to room temperature in the furnace.

[0020] The technical features and beneficial effects of the present invention are as follows:

[0021] 1. The present invention provides a method of using NaMP n O m (M=Mg or Ca, 0.9≤n≤1.3, 3.75≤m≤4.75) as the matrix, Eu 2+ The phosphate phosphor with the luminescence center is NaMP n O m :0.03Eu 2+ This type of phosphor produces broadband luminescence when excited by near-ultraviolet light.

[0022] 2. The present invention can adjust the luminescence performance of the phosphor by changing the relative content of phosphor in the phosphor composition.

[0023] 3. After a large number of experiments, it was unexpectedly discovered that the luminescence properties of phosphors can be controlled by changing the cooling method after high-temperature calcination of phosphors.

[0024] 4. The present invention can adjust the luminescence performance of the phosphor by changing the high-temperature calcination temperature of the phosphor.

[0025] 5. After a large number of experiments, it was unexpectedly discovered that the luminescence properties of phosphors can be regulated by changing the type of magnesium source in the phosphor preparation process.

[0026] 6. The present invention achieves regulation of the luminescence performance of the phosphor by replacing calcium carbonate with a magnesium source or replacing a magnesium source with calcium carbonate.

[0027] 7. The method for controlling the luminescence properties of the phosphors of the present invention enables the phosphors of the present invention to meet the varying requirements for luminescence properties in different application fields, thus possessing broad application prospects. Such phosphors are suitable for use in LED light-emitting devices and are of great significance in lighting, plant supplementary lighting, and displays.

[0028] 8. The phosphor luminescence performance control method of the present invention is specific to the phosphor composition of the present invention. If the phosphor matrix changes, the control method of the present invention will not be applicable. In the control method of the present invention, the furnace temperature is lowered to 850-900°C during the quench cooling method. This temperature is particularly important; if the temperature is lowered to a lower temperature (e.g., 400 / 500°C) and the sample is then taken out for quench cooling, the control effect will be poor. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1is the emission spectrum of the phosphor prepared in Example 1-3 under excitation of light at a wavelength of 370 nm;

[0030] Figure 2 is the X-ray diffraction (XRD) pattern of the phosphor prepared in Example 1;

[0031] Figure 3 is the X-ray diffraction (XRD) pattern of the phosphor prepared in Example 2;

[0032] Figure 4 is the X-ray diffraction (XRD) pattern of the phosphor prepared in Example 3;

[0033] Figure 5 is the emission spectrum of the phosphor prepared in Examples 1 and 4 under excitation of light at a wavelength of 370 nm;

[0034] Figure 6 is the X-ray diffraction (XRD) pattern of the phosphor prepared in Examples 1 and 4;

[0035] Figure 7 is the emission spectrum of the phosphor prepared in Examples 1 and 5 under excitation of light at a wavelength of 370 nm;

[0036] Figure 8 is the emission spectrum of the phosphor prepared in Examples 1 and 6 under excitation of light at a wavelength of 370 nm;

[0037] Figure 9 is the emission spectrum of the phosphor prepared in Examples 1 and 7 under excitation of light at a wavelength of 370 nm. DETAILED DESCRIPTION

[0038] The present application is further described in conjunction with the accompanying drawings and specific examples, which are intended to illustrate but not limit the scope of the present application. The raw materials used in the examples are all conventional and commercially available; the methods, if not otherwise specified, are all prior art.

[0039] Example 1:

[0040] A Eu 2+ doped phosphor with a molar composition of NaMgPO4: 0.03Eu 2+ was prepared by a high-temperature solid-phase method, and the main steps are as follows:

[0041] (1) According to the composition of the above phosphor, accurately weigh sodium carbonate (Na2CO3) 1.5141 g, basic magnesium carbonate [(MgCO3)4·Mg(OH)2·5H2O] 2.7751 g, ammonium dihydrogen phosphate (NH4H2PO4) 3.2863 g, and europium oxide (Eu2O3) 0.1508 g;

[0042] (2) Clean the agate mortar with clean water and rinse it with alcohol. Place the agate mortar in an oven to dry, then place the raw materials weighed above into the agate mortar one by one and grind them thoroughly for 20 minutes to mix them evenly, and then place them in a crucible;

[0043] (3) Place the crucible containing the sample in a muffle furnace, heat it to 400°C at a rate of 5°C / min in an air atmosphere, and keep it at that temperature for 4 hours to complete pre-sintering;

[0044] (4) After the pre-fired sample is naturally cooled to room temperature in the furnace, take out the sample and grind it again. The resulting powder is placed in a small crucible, and then the small crucible is placed in a large crucible. Carbon powder is placed between the large and small crucibles. The mouth of the large crucible is covered with a lid to form a relatively closed space. The large crucible is then placed in a muffle furnace and heated to 1100°C at a heating rate of 5°C / min and kept warm for 4 hours.

[0045] (5) After the insulation is completed, when the temperature in the muffle furnace (natural cooling) drops to 870°C, turn off the power supply of the muffle furnace, open the muffle furnace door, use crucible tongs to take out the calcined large crucible and place it on refractory bricks at room temperature for quenching and cooling to room temperature;

[0046] (6) After cooling to room temperature, the small crucible is taken out and the sample in the small crucible is ground into powder to obtain phosphor powder.

[0047] Example 2:

[0048] A kind of Eu 2+ Doped phosphor, its molar composition is NaMgP 1.1 O 4.25 :0.03Eu 2+ , prepared by high temperature solid phase method, the main steps are as follows:

[0049] (1) According to the composition of the above phosphor, accurately weigh 1.5141g of sodium carbonate (Na2CO3), 2.7751g of basic magnesium carbonate [(MgCO3)4·Mg(OH)2·5H2O], 3.6149g of ammonium dihydrogen phosphate (NH4H2PO4), and 0.1508g of europium oxide (Eu2O3);

[0050] (2) Clean the agate mortar with clean water and rinse it with alcohol. Place the agate mortar in an oven to dry, then place the raw materials weighed above into the agate mortar one by one and grind them thoroughly for 20 minutes to mix them evenly, and then place them in a crucible;

[0051] (3) Place the crucible containing the sample in a muffle furnace, heat it to 400°C at a rate of 5°C / min in an air atmosphere, and keep it at that temperature for 4 hours to complete pre-sintering;

[0052] (4) After the pre-fired sample is naturally cooled to room temperature in the furnace, take out the sample and grind it again. The resulting powder is placed in a small crucible, and then the small crucible is placed in a large crucible. Carbon powder is placed between the large and small crucibles. The mouth of the large crucible is covered with a lid to form a relatively closed space. The large crucible is then placed in a muffle furnace and heated to 1100°C at a heating rate of 5°C / min and kept warm for 4 hours.

[0053] (5) After the insulation is completed, when the temperature in the muffle furnace (natural cooling) drops to 870°C, turn off the power supply of the muffle furnace, open the muffle furnace door, use crucible tongs to take out the calcined large crucible and place it on refractory bricks for quenching and cooling to room temperature;

[0054] (6) After cooling to room temperature, the small crucible is taken out and the sample in the small crucible is ground into powder to obtain phosphor powder.

[0055] Example 3:

[0056] A kind of Eu 2+ Doped phosphor, its molar composition is NaMgP 1.2 O 4.5 :0.03Eu 2+ , prepared by high temperature solid phase method, the main steps are as follows:

[0057] (1) According to the composition of the above phosphor, accurately weigh 1.5141g of sodium carbonate (Na2CO3), 2.7751g of basic magnesium carbonate [(MgCO3)4·Mg(OH)2·5H2O], 3.9435g of ammonium dihydrogen phosphate (NH4H2PO4), and 0.1508g of europium oxide (Eu2O3);

[0058] (2) Clean the agate mortar with clean water and rinse it with alcohol. Place the agate mortar in an oven to dry, then place the raw materials weighed above into the agate mortar one by one and grind them thoroughly for 20 minutes to mix them evenly, and then place them in a crucible;

[0059] (3) Place the crucible containing the sample in a muffle furnace, heat it to 400°C at a rate of 5°C / min in an air atmosphere, and keep it at that temperature for 4 hours to complete pre-sintering;

[0060] (4) After the pre-fired sample is naturally cooled to room temperature in the furnace, take out the sample and grind it again. The resulting powder is placed in a small crucible, and then the small crucible is placed in a large crucible. Carbon powder is placed between the large and small crucibles. The mouth of the large crucible is covered with a lid to form a relatively closed space. The large crucible is then placed in a muffle furnace and heated to 1100°C at a heating rate of 5°C / min and kept warm for 4 hours.

[0061] (5) After the insulation is completed, when the temperature in the muffle furnace (natural cooling) drops to 870°C, turn off the power supply of the muffle furnace, open the muffle furnace door, use crucible tongs to take out the calcined large crucible and place it on refractory bricks for quenching and cooling to room temperature;

[0062] (6) After cooling to room temperature, the small crucible is taken out and the sample in the small crucible is ground into powder to obtain phosphor powder.

[0063] The phosphors prepared in Examples 1-3 were excited with light of 370 nm wavelength, and the emission spectra were as follows: Figure 1 As shown. Figure 1 It can be seen that for the phosphors prepared in Example 1 and Example 2, the emission spectrum shows two emission bands, which are located in the blue light region and the red light region, respectively. As the phosphor content increases, the emission peak intensity in the red light region of the emission spectrum decreases, and the luminescence peak (620nm) of Example 2 is blue-shifted compared with the luminescence peak (625nm) of Example 1. In the blue light region, the luminescence peak (458nm) of Example 2 is red-shifted compared with the luminescence peak (445nm) of Example 1. For the phosphors prepared in Examples 1-3, the emission peak intensity in the blue light region is enhanced as the phosphor content increases. It can be seen that the luminescence properties of the phosphors change with the change of the phosphor content. Therefore, we can regulate the luminescence properties of the phosphors by adjusting the phosphor content in the phosphors.

[0064] The X-ray diffraction (XRD) patterns of the phosphors prepared in Examples 1-3 are as follows: Figure 2-4 The phosphor powder prepared in Example 1 contains NaMgPO4 (PDF#32-1119) and Na3PO4 (PDF#32-1142) crystals; the phosphor powder prepared in Example 2 contains three kinds of crystals, namely: Na2MgP2O7 (PDF#48-0574), P2O5 (PDF#23-1301) and Na2O2 (PDF#74-0111); the phosphor powder prepared in Example 3 contains three kinds of crystals, namely: Na 1.05 Mg 3.96 (PO4)3 (PDF#54-0072), Na2MgP2O7 (PDF#48-0574), and P2O5 (PDF#23-1301). The XRD patterns of Examples 1-3 show that by varying the relative phosphor content in the phosphor composition, the crystal type of the phosphor can be adjusted, thereby regulating the luminescence properties of the phosphor.

[0065] Example 4:

[0066] A kind of Eu 2+ Doped phosphor, its molar composition is NaMgPO4:0.03Eu 2+ , prepared by high temperature solid phase method, the main steps are as follows:

[0067] (1) According to the composition of the above fluorescent powder, accurately weigh sodium carbonate (Na2CO3) 1.5141 g, basic magnesium carbonate [(MgCO3)4·Mg(OH)2·5H2O] 2.7751 g, ammonium dihydrogen phosphate (NH4H2PO4) 3.2863 g, europium oxide (Eu2O3) 0.1508 g;

[0068] (2) Wash the agate mortar with clean water and rinse with alcohol. After drying the agate mortar in an oven, put the above-mentioned raw materials into the agate mortar one by one and grind for 20 min to make them mix uniformly and place them in a crucible;

[0069] (3) Put the crucible containing the sample into a muffle furnace and heat to 400℃ at a rate of 5℃ / min in air atmosphere, and keep the temperature for 4 h to complete the pre-burning;

[0070] (4) After the sample is naturally cooled to room temperature, take out the sample, grind it again, put the obtained powder into a small crucible, and then put the small crucible into a large crucible. Put carbon powder between the large crucible and the small crucible, cover the mouth of the large crucible with a lid to form a relatively closed space. Then put the large crucible into a muffle furnace and heat to 1100℃ at a rate of 5℃ / min, and keep the temperature for 4 h;

[0071] (5) After the heat preservation is completed, naturally cool the muffle furnace to room temperature, take out the small crucible, and grind the sample in the small crucible into powder to obtain the fluorescent powder.

[0072] The emission spectrum of the fluorescent powder prepared in Example 1 and Example 4 excited by 370 nm wavelength light is shown in Figure 5 . As can be seen from Figure 5 , the emission spectrum of the fluorescent powder prepared in Example 1 shows two emission peaks at 445 nm and 625 nm. The two emission peaks of the fluorescent powder are derived from the 4f 2+ →4f 7 5d 6 electron transition of Eu 1 . The emission spectrum of the fluorescent powder prepared in Example 4 only has one emission peak at 447 nm. Compared with Example 1 (quenching), the red light emission band disappears and the blue light emission intensity increases in Example 4 (furnace cooling).

[0073] The X-ray diffraction (XRD) patterns of the fluorescent powders prepared in Examples 1 and 4 are shown in Figure 6 . The fluorescent powders prepared in Examples 1 and 4 both contain NaMgPO4 (PDF #32-1119) and Na3PO4 (PDF #32-1142) crystals; the relative intensities of some diffraction peaks in the XRD patterns of Examples 1 and 4 are different (e.g. Figure 6 The diffraction pattern of Example 1 contains diffraction peaks at 22.4° and 28.8°, while the diffraction pattern of Example 4 has no distinct diffraction peaks at these two angles. The phosphors prepared in Examples 1 and 4 have different microstructures, resulting in different luminescence properties. By varying the cooling method, the crystal structure of the phosphor can be altered, thereby regulating its luminescence properties.

[0074] Example 5:

[0075] A kind of Eu 2+ Doped phosphor, its molar composition is NaMgPO4:0.03Eu 2+ , prepared by high temperature solid phase method, the main steps are as follows:

[0076] (1) According to the composition of the above phosphor, accurately weigh 1.7665g of sodium carbonate (Na2CO3), 1.3433g of magnesium oxide (MgO), 3.8340g of ammonium dihydrogen phosphate (NH4H2PO4), and 0.1760g of europium oxide (Eu2O3);

[0077] (2) Clean the agate mortar with clean water and rinse it with alcohol. Place the agate mortar in an oven to dry, then place the raw materials weighed above into the agate mortar one by one and grind them thoroughly for 20 minutes to mix them evenly, and then place them in a crucible;

[0078] (3) Place the crucible containing the sample in a muffle furnace, heat it to 400°C at a rate of 5°C / min in an air atmosphere, and keep it at that temperature for 4 hours to complete pre-sintering;

[0079] (4) After the pre-fired sample is naturally cooled to room temperature in the furnace, take out the sample and grind it again. The resulting powder is placed in a small crucible, and then the small crucible is placed in a large crucible. Carbon powder is placed between the large and small crucibles. The mouth of the large crucible is covered with a lid to form a relatively closed space. The large crucible is then placed in a muffle furnace and heated to 1100°C at a heating rate of 5°C / min and kept warm for 4 hours.

[0080] (5) After the insulation is completed, when the temperature in the muffle furnace (natural cooling) drops to 870°C, turn off the power supply of the muffle furnace, open the muffle furnace door, use crucible tongs to take out the calcined large crucible and place it on refractory bricks at room temperature for quenching and cooling to room temperature;

[0081] (6) After cooling to room temperature, the small crucible is taken out and the sample in the small crucible is ground into powder to obtain phosphor powder.

[0082] The emission spectra of the phosphors prepared in Example 1 and Example 5 under the excitation of light with a wavelength of 370 nm are shown in FIG. Figure 7As shown in the figure, the emission spectrum of the phosphor prepared in Example 1 shows two emission peaks, namely 445 and 625 nm; the emission spectrum of the phosphor prepared in Example 5 shows only one emission peak at 430 nm under 370 nm excitation. The raw material for introducing Mg in Example 1 is basic magnesium carbonate [(MgCO3)4·Mg(OH)2·5H2O], while the raw material for introducing Mg in Example 5 is magnesium oxide (MgO). It can be seen that when preparing phosphors, different raw materials for introducing Mg will also change the luminescence properties of the prepared phosphors.

[0083] Example 6:

[0084] A kind of Eu 2+ Doped phosphor, its molar composition is NaCaPO4:0.03Eu 2+ , prepared by high temperature solid phase method, the main steps are as follows:

[0085] (1) According to the composition of the above phosphor, accurately weigh 1.5141g of sodium carbonate (Na2CO3), 2.8597g of calcium carbonate (CaCO3), 3.2863g of ammonium dihydrogen phosphate (NH4H2PO4), and 0.1508g of europium oxide (Eu2O3);

[0086] (2) Clean the agate mortar with clean water and rinse it with alcohol. Place the agate mortar in an oven to dry, then place the raw materials weighed above into the agate mortar one by one and grind them thoroughly for 20 minutes to mix them evenly, and then place them in a crucible;

[0087] (3) Place the crucible containing the sample in a muffle furnace, heat it to 400°C at a rate of 5°C / min in an air atmosphere, and keep it at that temperature for 4 hours to complete pre-sintering;

[0088] (4) After the pre-fired sample is naturally cooled to room temperature in the furnace, take out the sample and grind it again. The resulting powder is placed in a small crucible, and then the small crucible is placed in a large crucible. Carbon powder is placed between the large and small crucibles. The mouth of the large crucible is covered with a lid to form a relatively closed space. The large crucible is then placed in a muffle furnace and heated to 1100°C at a heating rate of 5°C / min and kept warm for 4 hours.

[0089] (5) After the insulation is completed, when the temperature in the muffle furnace (natural cooling) drops to 870°C, turn off the power supply of the muffle furnace, open the muffle furnace door, use crucible tongs to take out the calcined large crucible and place it on refractory bricks at room temperature for quenching and cooling to room temperature;

[0090] (6) After cooling to room temperature, the small crucible is taken out and the sample in the small crucible is ground into powder to obtain phosphor powder.

[0091] The emission spectra of the phosphors prepared in Example 1 and Example 6 under the light excitation of 370nm wavelength are shown in the figure below: Figure 8 As shown in the figure, the emission spectrum of the phosphor prepared in Example 1 shows two emission peaks at 445 and 625 nm under the excitation of 370 nm wavelength; the emission spectrum of the phosphor prepared in Example 6 shows only one emission peak at 511 nm under the excitation of 370 nm wavelength. 2+ ) and Example 6 (NaCaPO4: 0.03Eu 2+ ) Compared with the above results, it can be seen that the luminescence properties of the phosphor can be regulated by replacing Mg in the phosphor matrix with Ca.

[0092] Example 7:

[0093] A kind of Eu 2+ Doped phosphor, its molar composition is NaMgPO4:0.03Eu 2+ , prepared by high temperature solid phase method, the main steps are as follows:

[0094] (1) According to the composition of the above phosphor, accurately weigh 1.5141g of sodium carbonate (Na2CO3), 2.7751g of basic magnesium carbonate [(MgCO3)4·Mg(OH)2·5H2O], 3.2863g of ammonium dihydrogen phosphate (NH4H2PO4), and 0.1508g of europium oxide (Eu2O3);

[0095] (2) Clean the agate mortar with clean water and rinse it with alcohol. Place the agate mortar in an oven to dry, then place the raw materials weighed above into the agate mortar one by one and grind them thoroughly for 20 minutes to mix them evenly, and then place them in a crucible;

[0096] (3) Place the crucible containing the sample in a muffle furnace, heat it to 400°C at a rate of 5°C / min in an air atmosphere, and keep it at that temperature for 4 hours to complete pre-sintering;

[0097] (4) After the pre-fired sample is naturally cooled to room temperature in the furnace, take out the sample and grind it again. The resulting powder is placed in a small crucible, and then the small crucible is placed in a large crucible. Carbon powder is placed between the large and small crucibles. The mouth of the large crucible is covered with a lid to form a relatively closed space. The large crucible is then placed in a muffle furnace and heated to 1000°C at a heating rate of 5°C / min and kept warm for 4 hours.

[0098] (5) After the insulation is completed, when the temperature in the muffle furnace (natural cooling) drops to 870°C, turn off the power supply of the muffle furnace, open the muffle furnace door, use crucible tongs to take out the calcined large crucible and place it on refractory bricks at room temperature for quenching and cooling to room temperature;

[0099] (6) After cooling to room temperature, the small crucible is taken out and the sample in the small crucible is ground into powder to obtain phosphor powder.

[0100] The emission spectra of the phosphors prepared in Example 1 and Example 7 under the excitation of light with a wavelength of 370 nm are shown in FIG. Figure 9 As shown in the figure, the emission spectra of the phosphors prepared in Example 1 and Example 7 show two emission peaks. As the calcination temperature decreases, the emission peak intensity in the blue region of the emission spectrum increases significantly. The blue and red emission bands in the phosphor emission spectrum are due to Eu 2+ When the temperature changes, the Eu on different sites in the prepared phosphor 2+ The change in the phosphor content causes a change in the emission spectrum. Therefore, when the phosphor's calcination temperature changes, its luminescence properties change. Therefore, we can control the phosphor's luminescence properties by adjusting the phosphor's calcination temperature.

Claims

1. A Eu-doped phosphor, characterized in that: Its molar composition is as follows: NaMP n O m :0.03Eu 2+ , M=Mg or Ca, 0.9≤n≤1.3, 3.75≤m≤4.75; The preparation method of the Eu-doped phosphor comprises the following steps: The raw materials of sodium carbonate, calcium carbonate or magnesium source, ammonium dihydrogen phosphate and europium oxide are ground and mixed uniformly, and pre-fired in air atmosphere; after pre-fired, ground, calcined at high temperature in a reducing atmosphere, cooled, and ground again to obtain Eu-doped phosphor; The magnesium source is basic magnesium carbonate or magnesium oxide; the pre-sintering temperature is 350-450°C, the pre-sintering time is 3-5 h, and the heating rate is 4-6°C / min; the high-temperature calcination temperature is 1000-1100°C, the holding time is 3-5 h, and the heating rate is 4-6°C / min; the cooling method is quenching or furnace cooling; the quenching cooling method is as follows: when the furnace temperature naturally drops to 850-900°C, the calcined sample is taken out and cooled at room temperature until it cools to room temperature; the furnace cooling method is as follows: naturally cool to room temperature in the furnace.

2. The Eu-doped phosphor according to claim 1, characterized in that: The high-temperature calcination method is as follows: the powder obtained by pre-calcining and grinding is placed in a small crucible, and then the small crucible is placed in a large crucible, carbon powder is placed between the large crucible and the small crucible, and the mouth of the large crucible is covered with a lid to form a relatively closed space; then the large crucible is placed in a muffle furnace for high-temperature calcination.

3. The Eu-doped phosphor according to claim 1, characterized in that: The luminescence performance of the phosphor can be regulated by changing the relative content of phosphor in the phosphor composition by changing the dosage of ammonium dihydrogen phosphate; the luminescence performance of the phosphor can be regulated by replacing calcium carbonate with a magnesium source or vice versa; the luminescence performance of the phosphor can be regulated by changing the cooling method after high-temperature calcination; the luminescence performance of the phosphor can be regulated by changing the high-temperature calcination temperature; and the luminescence performance of the phosphor can be regulated by changing the type of magnesium source.

4. The method for controlling the luminescence performance of the Eu-doped phosphor according to claim 1, comprising the steps of: (1) Grind and mix the raw materials of sodium carbonate, calcium carbonate or magnesium source, ammonium dihydrogen phosphate and europium oxide, and pre-sinter them at 4-6℃ / min to 350-450℃ in air atmosphere for 3-5 h; grind the powder after pre-sintering, put the obtained powder into a small crucible, and then put the small crucible into a large crucible, place carbon powder between the large crucible and the small crucible, cover the mouth of the large crucible with a lid to form a relatively closed space, and then place the large crucible in a muffle furnace and heat it to 1000-1100℃ at 4-6℃ / min for high temperature calcination in a reducing atmosphere for 3-5 h, cool it, and grind it again to obtain Eu-doped phosphor; the cooling method is quenching or furnace cooling; the quenching cooling method is as follows: when the furnace temperature naturally drops to 850~900℃, take out the calcined sample and cool it at room temperature until it cools to room temperature; the furnace cooling method is as follows: naturally cool it to room temperature in the furnace; in, The magnesium source is basic magnesium carbonate or magnesium oxide; (2) By changing the amount of ammonium dihydrogen phosphate, the relative content of phosphor in the composition of the phosphor is changed, and the luminescence performance of the phosphor is regulated. By replacing calcium carbonate with a magnesium source or vice versa, the luminescence performance of the phosphor is regulated. By changing the cooling method after high-temperature calcination, the luminescence performance of the phosphor is regulated. By changing the high-temperature calcination temperature, the luminescence performance of the phosphor is regulated. By changing the type of magnesium source, the luminescence performance of the phosphor is regulated.

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