A silicate green luminescent phosphor suitable for near-ultraviolet-blue light excitation, a preparation method thereof, and a white light LED device

Abstract

The present invention relates to the field of luminescent materials, and provides a silicate green luminescent phosphor suitable for near-ultraviolet-blue light excitation, a preparation method thereof, and a white light LED device. The general chemical formula of the phosphor is Na 1‑x Y 1‑y M y SiO4:xEu 2+ (0﹤x≦0.05; M=Sc, 0≦y≦0.2; M=In, 0≦y≦0.20; M=Ga, 0≦y≦0.15), the phosphor has strong absorption in the 350~450nm band, can be effectively excited by near-ultraviolet-blue light, and emits green light with a main wavelength of 507~512nm. The phosphor has a low synthesis temperature, simple process, low cost, and is environmentally friendly, making it suitable for industrial expansion production. The green luminescent phosphor provided by the present invention is similar to CaAlSiN3:Eu 2+ Mixed with red phosphor, it can produce a warm white LED device with high color rendering index and low color temperature when driven by blue LED chip; 4+ By mixing red phosphor and driving a blue LED chip, a wide color gamut standard white light LED device can be obtained.

Description

Technical Field

[0001] The present invention belongs to the technical field of luminescent materials, and in particular relates to a silicate green luminescent phosphor suitable for near-ultraviolet-blue light excitation, a preparation method thereof, and a white light LED device. Background Art

[0002] White light emitting diode (LED) is a semiconductor light emitting device, which is a type of solid-state light source. Due to its advantages such as small size, low energy consumption, long life, high luminous efficiency and low environmental pollution, it has been successfully applied in solid-state lighting, backlight display and other fields. White light LED has become the fourth generation of all-solid-state green lighting source after incandescent lamps and fluorescent lamps in the lighting industry and has been widely used. Currently, the main commercial white light LED is composed of InGaN blue light chip and yellow Y3Al5O 12 :Ce 3+ (YAG:Ce 3+ ) phosphors, but due to the lack of red light in the emission spectrum, white light LEDs have a low color rendering index (CRI < 75) and a high color temperature (CCT > 6000K), which greatly limits their further application.

[0003] To solve this problem, people use near-ultraviolet / ultraviolet LED chips and red, green, and blue primary color phosphors to build white light LEDs. However, high color rendering requires that the phosphor emission spectrum contain three broad emission bands of green, yellow, and red. Currently, researchers are committed to developing high-efficiency green light phosphors. Currently, the main commercial green phosphors are β-Sialon:Eu 2+ (540nm), (Ba,Sr)2SiO4:Eu 2+ However, the harsh synthesis conditions of these phosphors (the synthesis temperature must reach above 1900°C) make them expensive, limiting their widespread application in white light LEDs. Summary of the Invention

[0004] In order to solve the problems existing in the prior art, the purpose of the present invention is to provide a silicate green luminescent phosphor suitable for near-ultraviolet-blue light excitation, a preparation method thereof, and a white light LED device. The phosphor has strong absorption in the near-ultraviolet-blue light region and can meet the green emission requirements of near-ultraviolet-blue light excitation. At the same time, the synthesis process is simple and the temperature is low.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A silicate green luminescent phosphor suitable for near-ultraviolet-blue light excitation, the green luminescent phosphor having the following general chemical formula:

[0007] Na 1-x Y 1-y M y SiO4:xEu 2+

[0008] Wherein, M is Sc, In or Ga; x is Eu 2+ Replace Na + The molar ratio of x is in the range of 0﹤x≦0.05; y is M 3+ Replace Y 3+ The molar ratio of

[0009] When M adopts Sc, 0≦y≦0.2;

[0010] When M is In, 0≦y≦0.20;

[0011] When M is Ga, 0≦y≦0.15.

[0012] The method for preparing the silicate green luminescent phosphor suitable for near-ultraviolet-blue light excitation of the present invention comprises the following steps:

[0013] Mixing raw material powders of silicate green luminescent phosphor suitable for near-ultraviolet-blue light excitation to obtain a raw material mixture;

[0014] The raw material mixture is pre-calcined at 600-800° C. for 4-6 hours, cooled to room temperature after the pre-calcination, ground into powder and mixed to obtain an intermediate;

[0015] Pressing the intermediate into a sheet-shaped body;

[0016] The sheet-like molded body is subjected to a primary calcination under a reducing atmosphere; after the primary calcination, the sheet-like molded body is naturally cooled and ground into powder; the ground powder is then pressed into a sheet-like molded body, and the sheet-like molded body is subjected to a secondary calcination under a reducing atmosphere; after the secondary calcination, the sheet-like molded body is naturally cooled and ground into powder to obtain the silicate green luminescent phosphor suitable for near-ultraviolet-blue light excitation;

[0017] The calcination conditions of the primary calcination and the secondary calcination are the same, the calcination temperature is 1250-1400° C., and the calcination time is 4-8 hours.

[0018] Preferably, during the primary calcination and the secondary calcination, the material is placed in a crucible and carried out in a tubular furnace protected by a reducing atmosphere. The crucible can be a corundum crucible or a graphite crucible, preferably a graphite crucible, which can provide stronger reducing ability.

[0019] Preferably, the raw materials of the silicate green luminescent phosphor suitable for near-ultraviolet-blue light excitation are compounds containing Na, YM, Si, O and Eu elements.

[0020] Preferably, the compound comprises metal oxides or carbonates, and the silicon-containing compound is silicon dioxide.

[0021] Preferably, the pressure used when pressing into a sheet-shaped molded body is 13 to 18 MPa.

[0022] Preferably, the reducing atmosphere is a mixed gas of 5% to 10% H2 and 95% to 90% N2 by volume.

[0023] The present invention also provides a white light LED device, comprising a packaging substrate, a blue light LED chip, and a phosphor that can effectively absorb the light emitted by the blue light LED and release green and red light. The device is characterized in that the green light phosphor adopts the silicate green light-emitting phosphor suitable for near-ultraviolet-blue light excitation as described in claim 1.

[0024] Preferably, the chemical formula of the green phosphor is Na 0.98 Y 0.8 Sc 0.2 SiO4:0.02Eu 2+ The chemical formula of red phosphor is CaAlSiN3:Eu 2+ At this time, the white light LED device is a warm white light LED light-emitting device.

[0025] Preferably, the chemical formula of the green phosphor is Na 0.98 Y 0.8 Sc 0.2 SiO4:0.02Eu 2+ The chemical formula of red phosphor is K2SiF6:Mn 4+ At this time, the white light LED device is a standard white light LED lighting device.

[0026] Preferably, the blue light LED chip adopts a GaN semiconductor chip with an emission wavelength of 450nm.

[0027] The present invention has the following beneficial effects:

[0028] The luminescent matrix of the silicate green luminescent phosphor suitable for near ultraviolet-blue light excitation of the present invention adopts a silicate system. The matrix of the silicate system has the advantages of excellent physical and chemical properties, good thermal stability, relatively simple synthesis method and cheap and easy-to-obtain raw materials. The present invention adopts Eu 2+ ions act as activation centers, Eu 2+ The crystal field has a great influence on the 5d excited state energy level of the ion due to its exposed outer layer. 2+When in a strong crystal field environment, the splitting of the 5d orbital increases, the 5d energy level widens, and the luminescent material can be controllably adjusted from the blue light to the red light region. After testing, the silicate green luminescent phosphor suitable for near-ultraviolet-blue light excitation has a wide excitation spectrum range, strong absorption in the range of 260 to 470 nm, and the strongest absorption peak is at 350 to 420 nm, and can be effectively excited by near-ultraviolet-blue light; the green luminescent phosphor prepared by the present invention emits high-intensity green light under the excitation of near-ultraviolet-blue light, with an emission spectrum range of 440 to 630 nm and a main emission wavelength at 507 to 512 nm, and is suitable for near-ultraviolet-blue light conversion into green light phosphor;

[0029] In the preparation method of the present invention, the heat treatment process of pre-sintering and double calcining is determined according to the raw material composition, and the temperature is moderate, which can effectively save energy, is simple in process, environmentally friendly, has high product phase purity, and is easy to industrialize. The phosphor material selected in the present invention cannot be used to synthesize green phosphor under the condition of using only a reducing atmosphere.

[0030] Furthermore, the graphite crucible + reducing atmosphere reduction process provided by the present invention enables the phosphor to emit strong green light under the excitation of a near-ultraviolet-blue light chip; the Sc / Ga / In doped modification process provided by the present invention can prepare a silicate green luminescent phosphor suitable for near-ultraviolet-blue light excitation even in the presence of only a reducing atmosphere; the Sc / Ga / In doped modification process provided by the present invention and the graphite crucible + reducing atmosphere reduction process can further enhance the green light emission of the phosphor under the excitation of a near-ultraviolet-blue light chip.

[0031] The warm white LED device of the present invention uses the green luminescent phosphor provided by the present invention, which can be effectively excited by the blue light LED, so that the warm white LED device provided by the present invention can obtain a series of high-efficiency warm white light emissions under different driving currents.

[0032] The standard white light LED device of the present invention uses the green luminescent phosphor provided by the present invention, which can be effectively excited by the blue light LED, so that the standard white light LED device provided by the present invention can obtain a series of high-efficiency white light emissions under different driving currents. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 The X-ray diffraction pattern of the phosphor prepared in Example 1 of the present invention;

[0034] Figure 2 The phosphor prepared in Example 1 of the present invention excites (λ em =507nm) and emission (λ ex =383nm) spectrum;

[0035] Figure 3 This is the X-ray diffraction pattern of the phosphor prepared in Example 2 of the present invention;

[0036] Figure 4 The phosphor prepared in Example 2 of the present invention excites (λ em =512nm) and emission (λ ex =383nm) spectrum;

[0037] Figure 5 This is the electroluminescence spectrum of the warm white LED light-emitting device produced in Example 2;

[0038] Figure 6 This is the electroluminescence spectrum of the standard white light LED light-emitting device produced in Example 2;

[0039] Figure 7 The emission (λ ex =383nm) spectral intensity comparison chart;

[0040] Figure 8 This is the X-ray diffraction pattern of the phosphor prepared in Example 4 of the present invention;

[0041] Figure 9 This is the X-ray diffraction pattern of the phosphor prepared in Example 5 of the present invention;

[0042] Figure 10 The phosphor prepared in Example 5 of the present invention excites (λ em =509nm) and emission (λ ex =383nm) spectrum;

[0043] Figure 11 The emission (λ ex =383nm) spectral intensity comparison chart;

[0044] Figure 12 This is the X-ray diffraction pattern of the phosphor prepared in Example 7 of the present invention;

[0045] Figure 13 This is the X-ray diffraction pattern of the phosphor prepared in Example 8 of the present invention;

[0046] Figure 14 The phosphor prepared in Example 8 of the present invention excites (λ em =512nm) and emission (λ ex =383nm) spectrum.

[0047] Figure 15 The emission (λ ex=383nm) spectral intensity comparison chart;

[0048] Figure 16 This is the X-ray diffraction pattern of the phosphor prepared in Example 10 of the present invention;

[0049] Figure 17 These are the X-ray diffraction patterns of the phosphors of Example 1, Example 2, Example 5, and Example 8. DETAILED DESCRIPTION

[0050] The present invention will be described in detail below with reference to the embodiments and drawings, which are only for explanation of the present invention, and the feasible implementation modes of the present invention are not limited thereto.

[0051] The chemical formula of the silicate green luminescent phosphor suitable for near-ultraviolet-blue light excitation of the present invention is as follows:

[0052] Na 1-x Y 1-y M y SiO4:xEu 2+ , where M is Sc, In or Ga; x is Eu 2+ Replace Na + The molar ratio of x is in the range of 0﹤x≦0.05; y is Sc 3+ 、In 3+ or Ga 3+ Replace Y 3+ The molar ratio of y is as follows: (M=Sc, 0≦y≦0.2; M=In, 0≦y≦0.20; M=Ga, 0≦y≦0.15).

[0053] The method for preparing the silicate green luminescent phosphor suitable for near-ultraviolet-blue light excitation of the present invention specifically comprises the following steps:

[0054] Step (1): Accurately weigh the general formula Na according to the stoichiometric ratio 1-x Y 1-y M y SiO4:xEu 2+ Compounds containing elements such as Na, Y (Sc / Ga / In), Si, O, and Eu are used as raw materials, and the raw materials are ground and mixed uniformly to obtain a raw material mixture; wherein the compounds are metal oxides or carbonates, and the silicon-containing compound is silicon dioxide;

[0055] Step (2): The raw material mixture obtained in step (1) is placed in a corundum crucible, placed in a box furnace and pre-calcined at 600-800° C. for 4-6 hours, then cooled to room temperature and ground and mixed to obtain an intermediate;

[0056] Step (3): Grinding the intermediate obtained in step (2) into powder and pressing it into discs under a press at a pressure of 13 to 18 MPa; then placing the obtained discs in a crucible, calcining them at 1250 to 1400° C. for 4 to 8 hours in a tubular furnace protected by a reducing atmosphere, then naturally cooling and grinding them into powder; then calcining them again under the same conditions, naturally cooling and grinding them into powder; wherein the reducing atmosphere is a mixed gas of 5% to 10% H2 and 95% to 90% N2 by volume;

[0057] The present invention discloses a silicate green phosphor suitable for near-ultraviolet-blue light excitation, which is applied to a warm white LED device. The warm white LED device includes a blue LED chip and red and green phosphor layers disposed on the blue chip. The green phosphor is the silicate green phosphor suitable for near-ultraviolet-blue light excitation described above.

[0058] In the above solution of the present invention, the blue LED chip adopts a GaN semiconductor chip with an emission wavelength of 450nm; the green phosphor is typically non-limiting. 0.98 Y 0.8 Sc 0.2 SiO4:0.02Eu 2+ The red phosphor is CaAlSiN3:Eu 2 + .

[0059] The silicate green phosphor suitable for near-ultraviolet-blue light excitation of the present invention is applied to a standard white light LED device, which includes a blue LED chip and red and green phosphor layers disposed on the blue chip. The green phosphor is the silicate green phosphor suitable for near-ultraviolet-blue light excitation described above.

[0060] In the above solution of the present invention, the blue LED chip adopts a GaN semiconductor chip with an emission wavelength of 450nm; the green phosphor is typically non-limiting. 0.98 Y 0.8 Sc 0.2 SiO4:0.02Eu 2+ The red phosphor is K2SiF6:Mn 4+ .

[0061] Example 1

[0062] The preparation method of the silicate green luminescent phosphor suitable for near-ultraviolet-blue light excitation in this embodiment includes the following steps:

[0063] According to the chemical formula Na 0.98 YSiO4:0.02Eu 2+The chemical stoichiometric ratio of each element in the composition was accurately weighed: 9.8mmol NaHCO3, 5mmol Y2O3, 10mmol SiO2, and 0.1mmol Eu2O3. After grinding and mixing, the mixture was placed in a corundum crucible and pre-fired in a box furnace. After heating to 600°C and holding for 4 hours, the mixture was naturally cooled to room temperature and discharged. After being ground into powder, the mixture was pressed into discs on a tablet press (the pressure was set to 15 MPa). The sheet-like formed body was placed in a graphite crucible and placed in a high-temperature tube furnace with a 10% H2-90% N2 (volume ratio) mixed atmosphere. The mixture was heated to 1300°C and calcined for 7 hours. After naturally cooling to room temperature, the mixture was discharged, pressed into tablets again, and calcined again under the same calcination conditions. After cooling, the mixture was ground into powder to obtain a phosphor sample with high phase purity.

[0064] Figure 1 This is the X-ray diffraction pattern of the above phosphor. No obvious impurity diffraction peaks were observed, indicating that the phase purity of the phosphor is relatively high. Figure 2 is the excitation of the above phosphor (λ em =507nm) and emission (λ ex =383nm) spectrum, from Figure 2 As can be seen from the graph, the excitation spectrum of the phosphor prepared in this example ranges from 260 to 470 nm, with the strongest absorption peak at 383 nm, indicating that it can be effectively excited by near-ultraviolet light. The emission spectrum wavelength ranges from 440 to 630 nm, with the dominant emission wavelength at 507 nm, indicating that this phosphor is suitable for near-ultraviolet-blue light excitation-conversion into green phosphor.

[0065] Example 2

[0066] According to the chemical formula Na 0.98 Y 0.8 Sc 0.2 SiO4:0.02Eu 2+ The chemical stoichiometric ratio of each element in the composition is accurately weighed: 9.8mmol NaHCO3, 4mmol Y2O3, 1mmol Sc2O3, 10mmol SiO2, and 0.1mmol Eu2O3. After grinding and mixing, the mixture is placed in a corundum crucible and pre-fired in a box furnace. The mixture is heated to 700°C and held for 6 hours. After cooling naturally to room temperature, the mixture is discharged. After being ground into powder, the mixture is pressed into discs on a tablet press (the pressure is set to 18 MPa). The sheet-like formed body is placed in a graphite crucible and placed in a high-temperature tube furnace with a mixed atmosphere of 10% H2-90% N2 (volume ratio). The temperature is raised to 1400°C and calcined for 6 hours. After cooling naturally to room temperature, the mixture is discharged, pressed into tablets again, and calcined again under the same calcination conditions. After cooling to room temperature, the mixture is ground into powder to obtain a phosphor sample with high phase purity.

[0067] Figure 3The X-ray diffraction pattern of the above phosphor shows no obvious impurity diffraction peaks, indicating that the phosphor has a high phase purity. Figure 4 As shown, the excitation spectrum of the phosphor sample of this embodiment ranges from 260 to 470 nm, with the strongest absorption peak at 383 nm, indicating that it can be effectively excited by near-ultraviolet light. The emission spectrum ranges from 440 to 630 nm, with the dominant emission wavelength at 512 nm, indicating that this phosphor is suitable for near-ultraviolet-blue light excitation-conversion into green phosphor.

[0068] This embodiment provides a warm white LED device. The warm white LED light emitting device includes a package substrate, a blue LED chip, and a phosphor that can effectively absorb the blue LED light and release green and red light. The green phosphor is the green phosphor described in Example 2, and its chemical composition is Na 0.98 Y 0.8 Sc 0.2 SiO4:0.02Eu 2+ ; Red phosphor is CaAlSiN3:Eu 2 + The blue light chip is a GaN semiconductor chip with a peak emission wavelength of 450nm. The two phosphors are evenly dispersed in silica gel, coated or dispensed onto the chip, and the circuit is soldered to obtain the warm white LED light-emitting device of the present invention.

[0069] Table 1 shows the luminous efficacy data of the warm white LED packaged in this embodiment at different currents:

[0070] Table 1

[0071] Current (mA) Correlated color temperature (K) CIE-x CIE-y Color rendering index 20 3477 0.4157 0.4154 94.0 40 3498 0.4149 0.4160 94.4 60 3503 0.4150 0.4172 94.5 80 3510 0.4148 0.4178 94.6 100 3516 0.4148 0.4183 94.8 120 3519 0.4148 0.4188 94.9 140 3519 0.4149 0.4192 95.0 160 3519 0.4151 0.4195 95.2 180 3520 0.4150 0.4196 95.2 200 3515 0.4155 0.4201 95.3 220 3512 0.4156 0.4201 95.4 240 3506 0.4160 0.4202 95.4 260 3502 0.4163 0.4202 95.4 280 3493 0.4168 0.4204 95.3 300 3487 0.4171 0.4202 95.3

[0072] As can be seen from Table 1, the assembled LED device has stable color output and correlated color temperature under different driving currents, and can maintain a stable color rendering index.

[0073] The EL spectrum of the warm white LED device obtained in Example 2 is as follows: Figure 5 As shown, the red region has a stronger luminous intensity. Table 1 also shows the luminous efficacy data of the prepared LED at different currents. The prepared LED device exhibits a high color rendering index and a moderate color temperature, meeting people's demand for high-quality LEDs.

[0074] This embodiment provides a standard white light LED device. The standard white light LED light emitting device includes a package substrate, a blue light LED chip, and a phosphor that can effectively absorb the blue light LED light and release green and red light. The green light phosphor is the green light phosphor described in Example 2, and its chemical composition is Na 0.98 Y 0.8 Sc 0.2SiO4:0.02Eu 2+ ; Red phosphor is K2SiF6:Mn 4+ The blue light chip is a GaN semiconductor chip with a peak emission wavelength of 450nm. Two phosphors are evenly dispersed in silica gel, coated or dispensed onto the chip, and the circuit is soldered to produce the warm white LED light-emitting device of the present invention. This device can achieve a color gamut area of ​​94% of the NTSC standard.

[0075] Table 2 shows the luminous efficacy data of the standard white LED packaged in this embodiment at different currents:

[0076] Table 2

[0077] Current (mA) Correlated color temperature (K) CIE-x CIE-y Color rendering index 20 7026 0.3107 0.2937 36.6 40 6878 0.3118 0.2980 40.9 60 6973 0.3099 0.3012 45.3 80 6997 0.3091 0.3035 48.0 100 6985 0.3088 0.3056 49.8 120 6957 0.3089 0.3074 51.4

[0078] It can be seen from Table 2 that the assembled LED device has stable color output and correlated color temperature at different driving currents.

[0079] The EL spectrum of the standard white light LED device obtained in Example 2 is as follows: Figure 6 Table 2 also shows the luminous efficacy data of the prepared LED under different currents. The prepared LED device can meet people's needs for high-quality standard white light LEDs for display.

[0080] Example 3

[0081] According to the chemical formula Na 0.98 Y 0.8 Sc 0.2 SiO4:0.02Eu 2+ The chemical stoichiometric ratio of each element in the composition is accurately weighed: 9.8mmol NaHCO3, 4mmol Y2O3, 1mmol Sc2O3, 10mmol SiO2, and 0.1mmol Eu2O3. After grinding and mixing, the mixture is placed in a corundum crucible and pre-fired in a box furnace. The temperature is raised to 700°C and held for 5 hours. After cooling naturally to room temperature, the mixture is discharged. After being ground into powder, the mixture is pressed into discs on a tablet press (the pressure is set to 18 MPa). The sheet-like formed body is placed in the corundum crucible and placed in a high-temperature tube furnace with a mixed atmosphere of 10% H2-90% N2 (volume ratio). The temperature is raised to 1400°C and calcined for 4 hours. After cooling naturally to room temperature, the mixture is discharged, pressed into tablets again and calcined under the same calcination conditions. After cooling, the mixture is ground into powder to obtain a phosphor sample with high phase purity.

[0082] In Example 1, Example 2 and Example 3, the green phosphors were synthesized by using the following process methods: graphite crucible + reducing atmosphere reduction, graphite crucible + reducing atmosphere reduction + doping modification, and reducing atmosphere reduction + doping modification. ex=383nm) spectrum for comparison, such as Figure 7 As shown. Figure 7 It can be seen that the three process methods can make Eu 3+ Reduced to Eu 2+ , and the green phosphor obtained by the process of graphite crucible + reducing atmosphere reduction + doping modification has the highest luminous intensity.

[0083] Example 4

[0084] According to the chemical formula Na 0.98 Y 0.9 Sc 0.1 SiO4:0.02Eu 2+ The chemical stoichiometric ratios of the elements in the formula (a) were accurately weighed: 9.8 mmol NaHCO₃, 4.5 mmol Y₂O₃, 0.5 mmol Sc₂O₃, 10 mmol SiO₂, and 0.1 mmol Eu₂O₃. After grinding and mixing, the mixture was placed in a corundum crucible and pre-sintered in a box furnace. The mixture was heated to 700°C and held for 5 hours. After cooling naturally to room temperature, the mixture was discharged. After being ground into powder, the mixture was pressed into discs on a tablet press (at a pressure of 18 MPa). The sheet-like formed body was placed in a graphite crucible and placed in a high-temperature tube furnace with a 10% H₂-90% N₂ (volume ratio) mixed atmosphere. The mixture was heated to 1400°C and held for 4 hours. After cooling naturally to room temperature, the mixture was discharged, pressed into tablets again and calcined under the same calcination conditions. After cooling, the mixture was ground into powder to obtain a phosphor sample with high phase purity.

[0085] Figure 8 This is the X-ray diffraction pattern of the above phosphor. No obvious impurity diffraction peaks were observed, indicating that the phase purity of the phosphor is relatively high.

[0086] Example 5

[0087] According to the chemical formula Na 0.97 Y 0.8 In 0.2 SiO4:0.03Eu 2+The chemical stoichiometric ratios of the elements in the phosphor were accurately weighed: 4.85mmol NaCO, 4mmol YO, 1mmol InO, 10mmol SiO, and 0.15mmol EuO. The mixture was thoroughly ground and mixed, then loaded into a corundum crucible and pre-fired in a box furnace. The mixture was heated to 800°C and held for 4 hours. After cooling naturally to room temperature, the mixture was discharged. After being ground into a powder, the mixture was pressed into discs on a tablet press (at a pressure of 13 MPa). The sheet-like formed body was placed in a graphite crucible and placed in a high-temperature tube furnace with a mixed atmosphere of 5% H2-95% N2 (volume ratio). The temperature was raised to 1250°C and calcined for 4 hours. After cooling naturally to room temperature, the mixture was discharged, pressed into tablets again, and calcined again under the same calcination conditions. After cooling, the powder was ground into a powder to obtain a phosphor sample with high phase purity.

[0088] Figure 9 The X-ray diffraction pattern of the above phosphor shows no obvious impurity diffraction peaks, indicating that the phosphor has a high phase purity. Figure 10 As shown, the excitation spectrum of the phosphor sample of this embodiment has a wavelength range of 250-460 nm, with the strongest absorption peak at 383 nm, indicating that it can be effectively excited by near-ultraviolet light. The emission spectrum has a wavelength range of 450-600 nm, with the dominant emission wavelength at 509 nm, indicating that this phosphor is suitable for near-ultraviolet-blue light excitation conversion to green phosphor.

[0089] Example 6

[0090] According to the chemical formula Na 0.97 Y 0.8 In 0.2 SiO4:0.03Eu 2+ The chemical stoichiometric ratios of the elements in the formula (e) were accurately weighed: 4.85 mmol Na₂CO₃, 4 mmol Y₂O₃, 1 mmol In₂O₃, 10 mmol SiO₂, and 0.15 mmol Eu₂O₃. The mixture was thoroughly ground and mixed, then loaded into a corundum crucible and pre-fired in a box furnace. The mixture was heated to 800°C and held for 6 hours. After cooling naturally to room temperature, the mixture was discharged. After being ground into a powder, the mixture was pressed into discs using a tablet press (set to 13 MPa). The sheet-like formed body was placed in the corundum crucible and placed in a high-temperature tube furnace with a mixed atmosphere of 5% H₂-95% N₂ (volume ratio). The temperature was raised to 1250°C and calcined for 8 hours. After cooling naturally to room temperature, the mixture was discharged, pressed into tablets again, and calcined again under the same calcination conditions. After cooling, the powder was ground into a powder to obtain a phosphor sample with high phase purity.

[0091] In Example 1, Example 5 and Example 6, respectively, graphite crucible + reducing atmosphere reduction, graphite crucible + reducing atmosphere reduction + doping modification, and reducing atmosphere reduction + doping modification were used to synthesize green phosphors.ex =383nm) spectrum for comparison, such as Figure 11 As shown. Figure 11 It can be seen that the three process methods can make Eu 3+ Reduced to Eu 2+ , and the green phosphor obtained by the process of graphite crucible + reducing atmosphere reduction + doping modification has the highest luminous intensity.

[0092] Example 7

[0093] According to the chemical formula Na 0.98 Y 0.9 In 0.1 SiO4:0.02Eu 2+ The chemical stoichiometric ratios of the elements in the formula (e) were accurately weighed: 4.9 mmol Na₂CO₃, 4.5 mmol Y₂O₃, 0.5 mmol In₂O₃, 10 mmol SiO₂, and 0.1 mmol Eu₂O₃. The mixture was thoroughly ground and mixed, then loaded into a corundum crucible and pre-fired in a box furnace. The temperature was raised to 800°C and held for 4 hours. After cooling naturally to room temperature, the mixture was discharged. After being ground into powder, the mixture was pressed into discs using a tablet press (pressure set to 13 MPa). The sheet-like formed body was placed in a graphite crucible and placed in a high-temperature tube furnace with a mixed atmosphere of 5% H₂-95% N₂ (volume ratio). The temperature was raised to 1250°C and calcined for 4 hours. After cooling naturally to room temperature, the mixture was discharged, pressed into tablets again, and calcined again under the same calcination conditions. After cooling, the mixture was ground into powder to obtain a phosphor sample with high phase purity.

[0094] Figure 12 This is the X-ray diffraction pattern of the above phosphor. No obvious impurity diffraction peaks were observed, indicating that the phase purity of the phosphor is relatively high.

[0095] Example 8

[0096] According to the chemical formula Na 0.95 Y 0.9 Ga 0.1 SiO4:0.05Eu 2+The chemical stoichiometric ratios of the elements in the formula (a) were accurately weighed: 9.5 mmol NaHCO₃, 4.5 mmol Y₂O₃, 0.5 mmol Ga₂O₃, 10 mmol SiO₂, and 0.25 mmol Eu₂O₃. The mixture was thoroughly ground and mixed, then loaded into a corundum crucible and pre-fired in a box furnace. The mixture was heated to 600°C and held for 4 hours. After cooling naturally to room temperature, the mixture was discharged. After being ground into a powder, the mixture was pressed into discs on a tablet press (at a pressure of 15 MPa). The sheet-like formed body was placed in a graphite crucible and placed in a high-temperature tube furnace with a 10% H₂-90% N₂ (volume ratio) mixed atmosphere. The temperature was raised to 1400°C and calcined for 6 hours. After cooling naturally to room temperature, the mixture was discharged, pressed into tablets again, and calcined again under the same calcination conditions. After cooling, the powder was ground into a powder to obtain a phosphor sample with high phase purity.

[0097] Figure 13 The X-ray diffraction pattern of the above phosphor shows no obvious impurity diffraction peaks, indicating that the phosphor has a high phase purity. Figure 14 As shown, the excitation spectrum of the phosphor sample of this embodiment has a wavelength range of 260-470 nm, with the strongest absorption peak at 383 nm, indicating that it can be effectively excited by near-ultraviolet light. The emission spectrum has a wavelength range of 450-630 nm, with the dominant emission wavelength at 512 nm, indicating that this phosphor is suitable for near-ultraviolet excitation conversion to blue phosphor.

[0098] Example 9

[0099] According to the chemical formula Na 0.95 Y 0.9 Ga 0.1 SiO4:0.05Eu 2+ The chemical stoichiometric ratios of the elements in the formula (a) were accurately weighed: 9.5 mmol NaHCO₃, 4.5 mmol Y₂O₃, 0.5 mmol Ga₂O₃, 10 mmol SiO₂, and 0.25 mmol Eu₂O₃. The mixture was thoroughly ground and mixed, then loaded into a corundum crucible and pre-fired in a box furnace. The mixture was heated to 600°C and held for 4 hours. After cooling naturally to room temperature, the mixture was discharged. After being ground into a powder, the mixture was pressed into discs on a tablet press (at a pressure of 15 MPa). The sheet-like formed body was placed in a graphite crucible and placed in a high-temperature tube furnace with a 10% H₂-90% N₂ (volume ratio) mixed atmosphere. The temperature was raised to 1400°C and calcined for 6 hours. After cooling naturally to room temperature, the mixture was discharged, pressed into tablets again, and calcined again under the same calcination conditions. After cooling, the powder was ground into a powder to obtain a phosphor sample with high phase purity.

[0100] In Example 1, Example 8 and Example 9, respectively, graphite crucible + reducing atmosphere reduction, graphite crucible + reducing atmosphere reduction + doping modification, and reducing atmosphere reduction + doping modification were used to synthesize green phosphors.ex =383nm) spectrum for comparison, such as Figure 15 As shown. Figure 15 It can be seen that the three process methods can make Eu 3+ Reduced to Eu 2+ , and the green phosphor obtained by the process of graphite crucible + reducing atmosphere reduction + doping modification has the highest luminous intensity.

[0101] Example 10

[0102] According to the chemical formula Na 0.96 Y 0.85 Ga 0.15 SiO4:0.04Eu 2+ The chemical stoichiometric ratios of the elements in the formula (a) were accurately weighed: 9.6 mmol NaHCO₃, 4.25 mmol Y₂O₃, 0.75 mmol Ga₂O₃, 10 mmol SiO₂, and 0.2 mmol Eu₂O₃. The mixture was thoroughly ground and mixed, then loaded into a corundum crucible and pre-fired in a box furnace. The mixture was heated to 600°C and held for 4 hours. After cooling naturally to room temperature, the mixture was discharged. After being ground into a powder, the mixture was pressed into discs on a tablet press (at a pressure of 15 MPa). The sheet-like formed body was placed in a graphite crucible and placed in a high-temperature tube furnace with a 10% H₂-90% N₂ (volume ratio) mixed atmosphere. The temperature was raised to 1400°C and calcined for 6 hours. After cooling naturally to room temperature, the mixture was discharged, pressed into tablets again, and calcined again under the same calcination conditions. After cooling, the powder was ground into a powder to obtain a phosphor sample with high phase purity.

[0103] Figure 16 This is the X-ray diffraction pattern of the above phosphor. No obvious impurity diffraction peaks were observed, indicating that the phase purity of the phosphor is relatively high.

[0104] Figure 17 The X-ray diffraction patterns of the phosphors of Example 1, Example 2, Example 5, and Example 8 show no obvious impurity diffraction peaks, indicating that the synthesized phosphors have a high phase purity.

[0105] The above embodiments are merely illustrative of the present invention and are not intended to limit the present invention. It is understood that those skilled in the art may make modifications and improvements based on the technical solution of the present invention, but the modifications and improvements made do not deviate from the essential scope of the embodiments of the present invention and are intended to fall within the scope of protection of the technical solution of the present invention.

Claims

1. A silicate green luminescent phosphor suitable for near-ultraviolet-blue light excitation, characterized in that: The green luminescent phosphor chemical formula is as follows: Than 1-x THE 1-y M y SiO4:xEu 2+ Wherein, M is Sc, In or Ga; x is Eu 2+ Replace Na + The molar ratio of x is in the range of 0﹤x≦0.05; y is M 3 + Replace Y 3+ The molar ratio of When M adopts Sc, 0<y≦0.2; When M uses In, 0<y≦0.20; When M is Ga, 0<y≦0.

15.

2. The method for preparing a silicate green luminescent phosphor suitable for near-ultraviolet-blue light excitation according to claim 1, characterized in that: The process includes the following: Mixing raw material powders of silicate green luminescent phosphor suitable for near-ultraviolet-blue light excitation to obtain a raw material mixture; The raw material mixture is pre-calcined at 600-800° C. for 4-6 hours, and after the pre-calcination, it is cooled to room temperature, ground into powder, and mixed to obtain an intermediate; Pressing the intermediate into a sheet-shaped body; The sheet-like molded body is subjected to a primary calcination under a reducing atmosphere; after the primary calcination, the sheet-like molded body is naturally cooled and ground into powder; the ground powder is then pressed into a sheet-like molded body, and the sheet-like molded body is subjected to a secondary calcination under a reducing atmosphere; after the secondary calcination, the sheet-like molded body is naturally cooled and ground into powder to obtain the silicate green luminescent phosphor suitable for near-ultraviolet-blue light excitation; The calcination conditions of the primary calcination and the secondary calcination are the same, the calcination temperature is 1250-1400° C., and the calcination time is 4-8 h.

3. The method for preparing a silicate green luminescent phosphor suitable for near-ultraviolet-blue light excitation according to claim 2, characterized in that: The raw materials of the silicate green luminescent phosphor suitable for near-ultraviolet-blue light excitation are compounds containing Na, Y, M, Si, O and Eu elements.

4. The method for preparing a silicate green luminescent phosphor suitable for near-ultraviolet-blue light excitation according to claim 3, characterized in that: The compound includes metal oxides or carbonates, and the silicon-containing compound is silicon dioxide.

5. The method for preparing a silicate green luminescent phosphor suitable for near-ultraviolet-blue light excitation according to claim 2, characterized in that: The pressure used when pressing into a sheet-shaped molded body is 13 to 18 MPa.

6. The method for preparing a silicate green luminescent phosphor suitable for near-ultraviolet-blue light excitation according to claim 2, characterized in that: The reducing atmosphere is a mixed gas of 5% to 10% H2 and 95% to 90% N2 by volume.

7. A white light LED device, characterized in that: It includes a packaging substrate, a blue light LED chip, and a phosphor that can effectively absorb the light emitted by the blue light LED and release green light and red light. It is characterized in that the green light phosphor adopts the silicate green light-emitting phosphor suitable for near-ultraviolet-blue light excitation as described in claim 1.

8. The white light LED device according to claim 7, characterized in that: The chemical formula of green luminescent phosphor is Na 0.98 Y 0.8 Sc 0.2 SiO4:0.02Eu 2+ The chemical formula of red phosphor is CaAlSiN3:Eu 2+ .

9. The white light LED device according to claim 7, characterized in that: The chemical formula of green luminescent phosphor is Na 0.98 Y 0.8 Sc 0.2 SiO4:0.02Eu 2+ The chemical formula of red phosphor is K2SiF6:Mn 4+ .

10. A white light LED device according to any one of claims 7 to 9, characterized in that: The blue light LED chip adopts a GaN semiconductor chip with an emission wavelength of 450 nm.

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