A violet high-response green fluorescent material, a preparation method and application thereof

Abstract

The present application relates to a kind of purple light high response green fluorescent material, the chemical expression of the fluorescent material is Lu2SiO5:xEu 2+ Wherein 0.01≤x≤0.05.Compared with prior art, the present application is a kind of wide excitation green fluorescent powder, it is a kind of new fluorescent material, has the advantage of physical and chemical properties stable, meanwhile, the fluorescent powder can be prepared by conventional solid phase reaction method.The present application fluorescent powder can be well matched with existing purple light chip, under the excitation of 400nm, keep about 75% of the best emission intensity, luminous performance is excellent, has the great development potential of being applied to the health lighting field such as purple light excitation white light LED, purple light excitation sunlight LED, purple light excitation full spectrum LED.

Description

Technical Field

[0001] This invention relates to the field of fluorescent material preparation technology, and in particular to a violet-light-responsive green fluorescent material, its preparation method, and its application. Background Technology

[0002] White light-emitting diodes (WLEDs), as the fourth generation of lighting sources, have received considerable attention in recent years due to their advantages such as high efficiency, long lifespan, and energy saving. Currently, commercially available WLEDs utilize a blue GaN chip combined with a yellow phosphor, YAG:Ce. 3+ Combined. However, due to YAG:Ce 3+ Phosphors lack green and red light components and have a low color rendering index (CRI < 80) and high color temperature (> 4500K), which limits their application in WLEDs. Furthermore, blue light chips suffer from incomplete conversion, which is harmful to human health and is therefore known as "blue light hazard." With the improvement of people's living standards, the demand for high-quality, comfortable, and healthy lighting is increasing. A high-quality full-spectrum WLED that simulates the solar spectrum has been proposed to meet the demand for solar-like healthy lighting. This solar-like full-spectrum WLED mainly achieves high color rendering, high luminous efficiency, and adjustable color temperature by combining a violet chip with red, green, and blue phosphors to provide solar-like healthy lighting. Green phosphor is an important component of the three-color phosphor, and the design and synthesis of green phosphors with strong absorption in the violet region plays an important role in healthy lighting. Summary of the Invention

[0003] The purpose of this invention is to provide a violet-light-responsive green-light fluorescent material, its preparation method, and its application.

[0004] The objective of this invention can be achieved through the following technical solution: a violet-light-responsive green fluorescent material, the chemical formula of which is Lu2SiO5:xEu 2+ , where 0.01≤x≤0.05.

[0005] In this invention, Lu2SiO5 is the matrix material, and Eu... 2+ This indicates partial substitution of Eu ions with Lu ions in the matrix material, where x represents the Eu dopant ion. 2+ The molar content.

[0006] Preferably, x = 0.01, 0.02, 0.03, 0.04 or 0.05.

[0007] Preferably, the violet-light-responsive green-light-fluorescent material is a powder material.

[0008] Preferably, the excitation spectrum of the violet-light high-response green fluorescent material covers the range of 200–470 nm.

[0009] More preferably, the excitation spectrum of the violet-light high-response green fluorescent material covers the range of 220–450 nm.

[0010] Preferably, the emission spectrum of the violet-light high-response green fluorescent material covers the range of 450–650 nm.

[0011] More preferably, the emission spectrum of the violet-light high-response green fluorescent material covers the range of 450–600 nm.

[0012] Preferably, the violet-light-responsive green fluorescent material maintains its optimal emission intensity of 75% under 400nm violet light excitation.

[0013] Preferably, the ultraviolet-light-responsive green fluorescent material can achieve strong green light emission with an emission center located at 504nm under ultraviolet, violet, and blue light excitation at 200-450nm.

[0014] A method for preparing the above-mentioned violet-light-responsive green-light-fluorescent material includes the following steps:

[0015] (1) Weigh europium source compound, lutetium source compound and silicon source compound raw material powders according to the stoichiometric ratio, grind them to make the raw material powders evenly mixed to obtain a mixture;

[0016] (2) The mixture obtained in step (1) is sintered at high temperature in air and cooled to obtain a white powder;

[0017] (3) Grind the white powder obtained in step (2) evenly, and then sinter it at high temperature by Al reduction method. After cooling, the high-response green fluorescent material is obtained.

[0018] Preferably, in step (1), europium source compound, lutetium source compound, silicon source compound and sodium source compound raw material powders are weighed and ground to mix the raw material powders evenly to obtain a mixture.

[0019] More preferably, the sodium source compound is Na2CO3, used as a flux.

[0020] Preferably, in step (1), the fluorescent material is prepared according to the chemical formula (Lu2SiO5:xEu). 2+ Based on the preparation of each raw material (where 0.01≤x≤0.05), 10-30wt% Na2CO3 is added as a flux to lower the reaction temperature.

[0021] More preferably, 20 wt% Na2CO3 is added as a flux.

[0022] Preferably, the europium source compound in step (1) is Eu2O3, the lutetium source compound is Lu2O3, and the silicon source compound is SiO2.

[0023] Preferably, the grinding time in step (1) is 5 to 120 minutes.

[0024] Preferably, the conditions for high-temperature sintering in step (2) are: sintering at 600-1400℃ for 1-10 hours.

[0025] Preferably, after high-temperature air sintering in step (2), the powder is further ground for 5 to 120 minutes to obtain a white powder.

[0026] Preferably, the cooling in step (2) refers to cooling to room temperature.

[0027] Preferably, the conditions for high-temperature sintering in step (3) are as follows: the ground white powder is mixed with aluminum powder and sintered at 500-1300°C for 0.5-15 hours under vacuum.

[0028] More preferably, during the high-temperature sintering in step (3), the system pressure is maintained at 0 MPa.

[0029] More preferably, the mass ratio of the white powder to the aluminum powder is (0.25-0.35):1.

[0030] More preferably, the mass ratio of the white powder to the aluminum powder is 0.3:1.

[0031] More preferably, the ground white powder is mixed with aluminum powder and then sintered in a tube furnace.

[0032] More preferably, the ground white powder is mixed with aluminum powder and placed in a crucible. The crucible is then placed in a vacuum tube furnace, evacuated, and sintered at 750–1300°C for 1–8 hours.

[0033] An application of the above-mentioned violet-light-responsive green fluorescent material is to use the violet-light-responsive green fluorescent material in healthy lighting.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. The phosphor of this invention is synthesized for the first time using a high-temperature solid-state method with Al reduction, and has a wide excitation band, which can effectively cover the absorption range of 200-450 nm, with the emission center located at 504 nm;

[0036] 2. The phosphor of this invention is Eu. 2+ Doped oxide-based green light-emitting phosphors have the advantage of stable physicochemical properties. They are synthesized using a solid-state method, and their preparation process is simple and conducive to industrial production.

[0037] 3. The phosphor of this invention is a broad-excitation green phosphor, a novel type of Eu-doped phosphor. 2+ Fluorescent materials have the advantage of stable physicochemical properties. At the same time, this phosphor can be prepared by conventional solid-phase reaction method. Using Na2CO3 as a flux can reduce the reaction temperature and avoid affecting its luminescence intensity. It has the characteristics of simple preparation process and is conducive to industrial production.

[0038] 4. The phosphor of this invention can be well matched with various existing ultraviolet and violet light chips. It maintains about 75% of the optimal emission intensity when excited at 400nm, exhibiting excellent luminescence performance, meeting the needs of the commercial market, and is suitable for applications of healthy lighting LEDs such as violet light-excited white LEDs, violet light-excited solar-like LEDs, and violet light-excited full-spectrum LEDs. Attached Figure Description

[0039] Figure 1 The photoexcitation-emission spectra of a high-response green phosphor for healthy lighting according to Embodiments 1-3 of the present invention are shown. Detailed Implementation

[0040] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0041] Unless otherwise specified, the reagents, methods, instruments, and equipment used in this invention are conventional in the art. Unless otherwise specified, the reagents and materials used in the following examples are all commercially available.

[0042] Example 1

[0043] This embodiment provides a method for preparing a violet-light-responsive green phosphor for healthy lighting, the steps of which are as follows:

[0044] 1. Weigh 1g of Lu2O3, Eu2O3 and SiO2 raw material powder according to the stoichiometric ratio (the mass ratio of each raw material is Lu2O3:SiO2:Eu2O3=0.8621:0.1302:0.0078), and add an additional 20wt% of Na2CO3.

[0045] 2. Place the above raw material mixture in an agate mortar and grind for 30 to 60 minutes. After the material is evenly mixed, load the mixture into an alumina crucible and calcine it in air at 1200°C for 8 hours. Then cool it to room temperature and grind it again for 30 to 60 minutes. Place it in an Al reducing atmosphere and calcine it at 1000°C for 6 hours. Cool it to room temperature to obtain the target product.

[0046] 3. Use a fluorescence spectrometer (HITACHI F-7500) to test the spectral properties of the phosphor in this system, such as... Figure 1 As shown in the figure. The results indicate that the phosphor in this system has a broad excitation band with a peak value near 370 nm and a high spectral peak value, which can be well matched with commercial ultraviolet light chips. Under excitation by a 370 nm ultraviolet light source, the phosphor emits bright green light, and the emission spectrum consists of a broad emission band (450–650 nm) with a peak value at 504 nm.

[0047] The ultraviolet-excited Eu obtained in this embodiment 2+ The general formula for doped green light emitting phosphors is Lu2SiO5:xEu. 2+ x is 0.01.

[0048] Example 2

[0049] This embodiment provides a method for preparing a violet-light-responsive green phosphor for healthy lighting, the steps of which are as follows:

[0050] 1. Weigh 1g of Lu2O3, Eu2O3 and SiO2 raw material powder according to the stoichiometric ratio (the mass ratio of each raw material is Lu2O3:SiO2:Eu2O3 = 0.8505:0.1338:0.0157), and add an additional 20wt% of Na2CO3.

[0051] 2. Place the above raw material mixture in an agate mortar and grind for 30 to 60 minutes. After the material is evenly mixed, load the mixture into an alumina crucible and calcine it in air at 1250°C for 8 hours. Then cool it to room temperature and grind it again for 30 to 60 minutes. Place it in an Al reducing atmosphere and calcine it at 1050°C for 6 hours. Cool it to room temperature to obtain the target product.

[0052] 3. Use a fluorescence spectrometer (HITACHI F-7500) to test the spectral properties of the phosphor in this system, such as... Figure 1 As shown in the figure. The results indicate that the phosphor in this system has a broad excitation band with a peak value near 370 nm and a high spectral peak value, which can be well matched with commercial ultraviolet light chips. Under excitation by a 370 nm ultraviolet light source, the phosphor emits bright green light, and the emission spectrum consists of a broad emission band (450–650 nm) with a peak value at 504 nm.

[0053] The ultraviolet-excited Eu obtained in this embodiment 2+ The general formula for doped green light emitting phosphors is Lu2SiO5:xEu. 2+ x is 0.02.

[0054] Example 3

[0055] This embodiment provides a method for preparing a violet-light-responsive green phosphor for healthy lighting, the steps of which are as follows:

[0056] 1. Weigh 1g of Lu2O3, Eu2O3 and SiO2 raw material powder according to the stoichiometric ratio (the mass ratio of each raw material is Lu2O3:SiO2:Eu2O3 = 0.8411:0.1351:0.0237), and add an additional 20wt% of Na2CO3.

[0057] 2. Place the above raw material mixture in an agate mortar and grind for 30 to 60 minutes. After the material is evenly mixed, load the mixture into an alumina crucible and calcine it in air at 1150°C for 6 hours. Then cool it to room temperature and grind it again for 30 to 60 minutes. Place it in an Al reducing atmosphere and calcine it at 1100°C for 4 hours. Cool it to room temperature to obtain the target product.

[0058] 3. Use a fluorescence spectrometer (HITACHI F-7500) to test the spectral properties of the phosphor in this system, such as... Figure 1 As shown in the figure. The results indicate that the phosphor in this system has a broad excitation band with a peak value near 370 nm and a high spectral peak value, which can be well matched with commercial ultraviolet light chips. Under excitation by a 370 nm ultraviolet light source, the phosphor emits bright green light, and the emission spectrum consists of a broad emission band (450–650 nm) with a peak value at 504 nm.

[0059] The ultraviolet-excited Eu obtained in this embodiment 2+ The general formula for doped green light emitting phosphors is Lu2SiO5:xEu. 2+ x is 0.03.

[0060] Example 4

[0061] This embodiment provides a method for preparing a violet-light-responsive green phosphor for healthy lighting, the steps of which are as follows:

[0062] 1. Weigh 1g of Lu2O3, Eu2O3 and SiO2 raw material powder according to the stoichiometric ratio (the mass ratio of each raw material is Lu2O3:SiO2:Eu2O3 = 0.8315:0.1365:0.0320), and add an additional 20wt% of Na2CO3.

[0063] 2. Place the above raw material mixture in an agate mortar and grind for 30 to 60 minutes. After the material is evenly mixed, load the mixture into an alumina crucible and calcine it in air at 1300°C for 8 hours. Then cool it to room temperature and grind it again for 30 to 60 minutes. Place it in an Al reducing atmosphere and calcine it at 1200°C for 4 hours. Cool it to room temperature to obtain the target product.

[0064] 3. Use a fluorescence spectrometer (HITACHI F-7500) to test the spectral properties of the phosphor in this system, such as... Figure 1 As shown in the figure. The results indicate that the phosphor in this system has a broad excitation band with a peak value near 370 nm and a high spectral peak value, which can be well matched with commercial ultraviolet light chips. Under excitation by a 370 nm ultraviolet light source, the phosphor emits bright green light, and the emission spectrum consists of a broad emission band (450–650 nm) with a peak value at 504 nm.

[0065] The ultraviolet-excited Eu obtained in this embodiment 2+ The general formula for doped green light emitting phosphors is Lu2SiO5:xEu. 2+ x is 0.04.

[0066] Example 5

[0067] This embodiment provides a method for preparing a violet-light-responsive green phosphor for healthy lighting, the steps of which are as follows:

[0068] 1. Weigh 1g of Lu2O3, Eu2O3 and SiO2 raw material powder according to the stoichiometric ratio (the mass ratio of each raw material is Lu2O3:SiO2:Eu2O3 = 0.8218:0.1379:0.0404), and add an additional 20wt% of Na2CO3.

[0069] 2. Place the above raw material mixture in an agate mortar and grind for 30 to 60 minutes. After the material is evenly mixed, load the mixture into an alumina crucible and calcine it in air at 1200°C for 8 hours. Then cool it to room temperature and grind it again for 30 to 60 minutes. Place it in an Al reducing atmosphere and calcine it at 1100°C for 6 hours. Cool it to room temperature to obtain the target product.

[0070] 3. Use a fluorescence spectrometer (HITACHI F-7500) to test the spectral properties of the phosphor in this system, such as... Figure 1 As shown in the figure. The results indicate that the phosphor in this system has a broad excitation band with a peak value near 370 nm and a high spectral peak value, which can be well matched with commercial ultraviolet light chips. Under excitation by a 370 nm ultraviolet light source, the phosphor emits bright green light, and the emission spectrum consists of a broad emission band (450–650 nm) with a peak value at 504 nm.

[0071] The ultraviolet-excited Eu obtained in this embodiment 2+ The general formula for doped green light emitting phosphors is Lu2SiO5:xEu. 2+ x is 0.05.

[0072] The preparation of violet-light high-response green phosphors in the different embodiments provided above, and the specific raw material composition and process parameters are shown in Table 1.

[0073] Table 1. Preparation process parameters and performance test results of Examples 1-5

[0074] Example 1 2 3 4 5 <![CDATA[Lu2O3]]> 0.8621 0.8505 0.8411 0.8315 0.8218 <![CDATA[SiO2]]> 0.1302 0.1338 0.1351 0.1365 0.1379 <![CDATA[Eu2O3]]> 0.0078 0.0157 0.0237 0.0320 0.0404 <![CDATA[Na2CO3]]> 0.2 0.2 0.2 0.2 0.2 Sintering time (h) 8 8 6 8 8 Sintering temperature (°C) 1200 1250 1150 1300 1200 Restoration time (h) 6 6 4 4 6 Reduction temperature (°C) 1000 1050 1100 1200 1100 (Tsinghua) 400nm Excitation and Retention Strength 73％ 75％ 73.4％ 75.5％ 74％

[0075] The violet-light-responsive green fluorescent material provided by this invention is a novel Eu... 2+ The doped oxide-based 504nm blue light emitting fluorescent material has a wide excitation band and an effective absorption range covering 220-450nm. It can be excited by ultraviolet and violet light and has the advantage of stable physical and chemical properties. Under 400nm excitation, the luminescence intensity still remains above 75%. It can respond highly to violet light excitation chips and can meet the urgent needs of current white LEDs, solar-like LEDs, full-spectrum LEDs, and health lighting LED light sources.

[0076] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A violet-light-responsive green-light-fluorescent material, characterized in that, The chemical formula of the fluorescent material is Lu2SiO5:xEu 2+ wherein 0.01≤x≤0.05; The preparation method of the purple light high-response green light fluorescent material comprises the following steps: (1) According to the metering ratio, the europium source compound, the lutetium source compound and the silicon source compound are weighed and ground to mix the powders uniformly to obtain a mixture; (2) The mixture obtained in step (1) is high-temperature sintered in air, and the powder is obtained after cooling; (3) The powder obtained in step (2) is ground uniformly, and then high-temperature sintered by Al reduction method, and the purple light high-response green light fluorescent material is obtained after cooling; In step (1), 10-30wt% Na2CO3 is added as a fluxing agent on the basis of preparing each raw material according to the chemical formula of the fluorescent material to reduce the reaction temperature; The europium source compound in step (1) is Eu2O3, the lutetium source compound is Lu2O3, and the silicon source compound is SiO2; The high-temperature sintering condition in step (2) is sintering at 600-1400℃ for 1-10 hours; The high-temperature sintering condition in step (3) is mixing the ground powder with aluminum powder and sintering at 500-1300℃ for 0.5-15 hours under vacuum condition; The purple light high-response green light fluorescent material is used for health lighting. 2.The violet high-response green fluorescent material of claim 1, wherein, The x is 0.01, 0.02, 0.03, 0.04 or 0.

05. 3.The violet high-response green fluorescent material of claim 1, wherein, The purple light high-response green light fluorescent material is a powdery material. 4.The violet high-response green fluorescent material of claim 1, wherein, The excitation spectrum range of the purple light high-response green light fluorescent material covers 200-470nm, and the emission spectrum range covers 450-650nm. 5.The violet high-response green fluorescent material of claim 1, wherein, The emission intensity of the purple light high-response green light fluorescent material under 400nm purple light excitation maintains 75% of the optimal emission.

Images