Cyan fluorescent material for purple light excited sunlight-like LED (light-emitting diode) as well as preparation method and application of cyan fluorescent material

Abstract

The invention relates to a purple-light-excited blue-light fluorescent material for a sunlight-like LED (light-emitting diode) as well as a preparation method and application of the blue-light fluorescent material. The chemical expression of the fluorescent material is Ca2LuZr2Al1. 5Ga1. 5O12: xCe < 3 + >, wherein x is more than or equal to 0.02 and less than or equal to 0.07. The blue light fluorescent material for the purple light excitation type sunlight LED is a brand new and unreported purple light excitation Ce < 3 + > doped oxide blue light emission fluorescent material, the fluorescent powder has a wide excitation band, the effective absorption range covers 300-450 nm, the fluorescent powder can be excited by purple light, and blue light with the central wavelength being 485 nm is emitted. The fluorescent powder has the advantage of stable physical and chemical properties, can be prepared by adopting a conventional solid-phase reaction method, has the characteristics of simple preparation process and facilitation of industrial production, and can be used as a good candidate material for wide application of a next-generation full-spectrum illumination white light LED (light-emitting diode). The fluorescent powder can be completely and well matched with the existing purple light chip, meets the commercial market requirements, and is suitable for application of white light LEDs, sunlight-like LEDs, full-spectrum LEDs and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of fluorescent material preparation, and in particular relates to a cyan fluorescent material excited by purple light and a preparation method and application thereof. Background Art

[0002] White light-emitting diodes (W-LEDs) have attracted extensive attention in the fields of scientific research and application due to their advantages such as low power consumption, high stability and excellent luminous efficiency. The current mainstream preparation method is to combine blue LED chips with yellow phosphor Y3Al5O 12 :Ce 3+ (YAG:Ce 3+ ) combination. However, the W-LED prepared by this method has a 3+ The lack of green and red components in phosphors results in a low color rendering index (CRI) (<80) and a high color temperature (>4500K), which limits their application in high color rendering lighting. In addition, unconverted blue light may be harmful to human health, which is known as "blue light hazard."

[0003] A more promising alternative is to combine near-ultraviolet (N-UV) chips with commercial blue, green, and red phosphors to achieve white light illumination. Among the many N-UV chips, purple chips with an emission wavelength of about 400nm show higher efficiency, with a quantum yield of about 70%, especially LED chips with an emission wavelength in the range of 410-420nm have been shown to have the highest efficiency. Therefore, white light W-LEDs prepared using purple chips combined with three-primary color phosphors are considered to be ideal W-LED devices. However, W-LEDs prepared by this method usually have a cyan emission gap (470-510nm), which poses an obstacle to the realization of a new generation of full-spectrum W-LED applications.

[0004] Some cyan phosphors have been reported, such as NaMgBO3:Ce 3+ Cyan phosphor, 325nm excited K 1.8 R 1.2 GdSi2O7:Ce 3+ Cyan phosphor, Ba2CaB2Si4O excited at 350nm 14 :Ce 3+ Cyan phosphor, and KBaScSi2O7:Ce excited at 370nm 3+ Cyan phosphors. Although these phosphors can emit cyan light, their excitation wavelengths do not fully match the requirements of efficient full-spectrum W-LEDs, which limits their performance to a certain extent. Therefore, the development of phosphors that can efficiently emit cyan light under violet light excitation is of great significance to the realization of full-spectrum W-LEDs. Summary of the invention

[0005] The purpose of the present invention is to provide a cyan fluorescent material for violet light-excited solar LEDs and a preparation method and application thereof. The cyan fluorescent material for violet light-excited solar LEDs provided by the present invention is a new type of violet light-excited Ce 3+ The doped oxide-based 485nm cyan-emitting phosphor can meet the urgent needs of current white light LEDs, sunlight-like LEDs, full-spectrum LEDs, and healthy lighting LED light sources.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] The present invention first provides a new type of cyan fluorescent material for violet light-excited solar LED (cyan fluorescent material excited by violet light), the chemical expression of which is Ca2LuZr2Al 1.5 Ga 1.5 O 12 :xCe 3+ Among them, 0.02≤x≤0.07.

[0008] Preferably, x=0.02, 0.03, 0.04, 0.05, 0.06, 0.07.

[0009] More preferably, x=0.04.

[0010] Furthermore, the cyan fluorescent material excited by violet light is a new type of violet light excited Ce 3+ Doped oxide cyan emitting phosphors.

[0011] In one embodiment of the present invention, the cyan fluorescent material for violet light-excited solar LED is a powdery material.

[0012] Furthermore, the violet light-excited solar LED uses a cyan fluorescent material with an excitation spectrum range of 300 to 450 nm.

[0013] Furthermore, the emission spectrum range of the cyan fluorescent material used in the violet light-excited solar LED covers 400 to 700 nm.

[0014] Furthermore, the effective absorption range of the cyan fluorescent material used in the violet light-excited solar LED covers 300 to 450 nm, and can be excited by ultraviolet and violet light, with the best excitation being at 410 nm.

[0015] Furthermore, the central emission wavelength is located at 484 nm, at which x=0.04. Compared with the intensities at x=0.02, 0.03, 0.05, 0.06, and 0.07, the intensity at x=0.04 is stronger.

[0016] The cyan fluorescent material for violet light-excited solar LED provided by the present invention is a brand-new, unreported violet light-excited Ce 3+ The doped oxide cyan light emitting fluorescent material has a wide excitation band, an effective absorption range covering 300-450nm, and an optimal excitation wavelength of 410nm, which can be well matched with the purple light chip. The phosphor can be prepared by a conventional solid phase reaction method, has the characteristics of simple preparation process and is conducive to industrial production, and can be used as a good candidate material for the wide application of full-spectrum white light LEDs. The phosphor can be well matched with the existing purple light chip, meet the needs of the commercial market, and is suitable for the application of white light LEDs, sunlight-like LEDs, full-spectrum LEDs, etc.

[0017] The present invention further provides a method for preparing the cyan fluorescent material for the violet light excited solar LED, comprising the following steps:

[0018] (1) weighing raw material powders of a calcium source compound, a lutetium source compound, a zirconium source compound, an aluminum source compound, a gallium source compound, and a cerium source compound according to a chemical expression and mixing them uniformly to obtain a mixed material;

[0019] (2) grinding and mixing the mixed material obtained in step (1) to obtain a ground raw material powder;

[0020] (3) Sintering the ground raw material powder obtained in step (2), and then cooling it to room temperature to finally obtain the cyan fluorescent material for the violet light-excited solar LED.

[0021] In one embodiment of the present invention, in step (1), according to the chemical formula of the fluorescent material Ca2LuZr2Al 1.5 Ga 1.5 O 12 :xCe 3+ , where 0.02≤x≤0.07.

[0022] In one embodiment of the present invention, in step (1), the calcium source compound is CaCO3, the lutetium source compound is Lu2O3, the zirconium source compound is ZrO2, the aluminum source compound is Al2O3, the gallium source compound is Ga2O3, and the cerium source compound is CeO2.

[0023] In one embodiment of the present invention, in step (2), the grinding time of the mixture is 5 to 120 minutes.

[0024] In one embodiment of the present invention, in step (3), the sintering is high-temperature sintering, and the conditions for the high-temperature sintering are: sintering in a reducing atmosphere, a sintering temperature of 1000-1600° C., and a sintering time of 2-12 hours.

[0025] In one embodiment of the present invention, in step (3), during high temperature sintering, the reducing atmosphere is selected from a mixed gas of H2 and N2.

[0026] In one embodiment of the present invention, in step (3), during high temperature sintering, the reducing atmosphere is selected from a mixed gas of 5% by volume H2 and 95% by volume N2.

[0027] In one embodiment of the present invention, in step (3), during high temperature sintering, the sintering temperature is more preferably 1400-1500°C.

[0028] In one embodiment of the present invention, in step (3), during high temperature sintering, the sintering time is more preferably 4 hours.

[0029] In one embodiment of the present invention, in step (3), during high-temperature sintering, the system pressure is maintained at 0 MPa (the reading displayed on the pressure gauge in the absence of any external pressure is actually equivalent to one atmosphere of pressure under standard atmospheric pressure).

[0030] In one embodiment of the present invention, in step (3), the high temperature sintering method is: the ground raw material powder obtained in step (2) is loaded into an alumina crucible, and then the alumina crucible containing the raw material is placed in a reducing atmosphere for sintering.

[0031] In one embodiment of the present invention, in step (3), cooling refers to cooling to room temperature.

[0032] The cyan fluorescent material for violet light-excited solar LED obtained by the preparation method of the present invention is a powdery material.

[0033] The present invention further provides an application of the cyan fluorescent material for violet light-excited solar LEDs, wherein the cyan fluorescent material for violet light-excited solar LEDs is used to prepare full-spectrum WLEDs.

[0034] In the phosphor system, garnet structure compound is an important oxide matrix material for LED phosphors, and its general formula is A3B2C3O 12 , where A, B and C can be replaced by a variety of cations. Due to its good stability and excellent physical and chemical properties, excellent luminescence properties can be achieved through chemical ion substitution and host cation regulation, so the garnet structure system is a very potential phosphor material.

[0035] As we all know, rare earth Ce 3+ Ions have typical spin-allowed and parity-allowed Transition, is an excellent activator for LED phosphors. By doping Ce in a suitable matrix material 3+ Ion, Ce 3+ The parity of the ions allows The transition makes the phosphor have strong absorption in the near-ultraviolet region, and Ce 3+ The parity of the ions allows The transition makes the phosphor have a wider emission band in the near-ultraviolet region. 3+ Ionic The transition is easily affected by the crystal field environment. 3+ Doped phosphors show significant differences in luminescence properties. Therefore, in order to achieve the desired Ce 3+ For ion emission, it is very important to choose a suitable host material. Garnet compounds are important oxide matrix materials for LED phosphors. Based on the above theory, the present invention will select Ce 3+ As the luminescent center of the phosphor, a phosphor Ca2LuZr2Al was synthesized that can be excited by purple light and has strong cyan emission. 1.5 Ga 1.5 O 12 :xCe 3+ The cyan fluorescent material for violet light-excited solar LED provided by the present invention is a brand-new, unreported violet light-excited Ce 3+ The doped oxide cyan light emitting fluorescent material has the following innovations:

[0036] (1) The phosphor of the present invention has a wide excitation band, and the effective absorption range covers 300-450nm, and can be excited by violet light. The obtained phosphor can emit cyan light with a central wavelength of 485nm under the excitation of 410nm violet light.

[0037] (2) The phosphor of the present invention is Ce 3+ Doped garnet structure cyan emitting phosphor, by Ce 3+ Ion doping in the garnet structure yields cyan emission.

[0038] (3) The phosphor of the present invention is prepared by a conventional solid-phase reaction method, has the characteristics of simple preparation process and is conducive to industrial production, and can be used as a good candidate material for the wide application of white light full-spectrum LEDs, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 The photoexcitation-emission spectra of the cyan phosphor excited by violet light prepared in Examples 1-6 of the present invention are as follows, wherein (a) is an excitation spectrum and (b) is an emission spectrum. DETAILED DESCRIPTION

[0040] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0041] The present invention relates to a cyan fluorescent material for violet light-excited solar LEDs and a preparation method and application thereof. The chemical expression of the fluorescent material is Ca2LuZr2Al 1.5 Ga 1.5 O 12 :xCe 3+ Wherein 0.02≤x≤0.07. The cyan fluorescent material for violet light-excited solar LED provided by the present invention is a brand-new and unreported violet light-excited Ce 3+ The doped oxide cyan light emitting fluorescent material has a wide excitation band, an effective absorption range covering 300-450nm, can be excited by violet light, and emits cyan light with a central wavelength of 485nm, and has the advantage of stable physical and chemical properties. At the same time, the phosphor can be prepared by conventional solid phase reaction method, has the characteristics of simple preparation process and conducive to industrial production, and can be used as a good candidate material for the wide application of next-generation full-spectrum lighting white light LED. The phosphor can be well matched with the existing violet light chip, meet the needs of the commercial market, and is suitable for the application of white light LED, sunlight-like LED, full-spectrum LED, etc.

[0042] Features such as component models, material names, connection structures, control methods, algorithms, etc. that are not clearly stated in this technical solution shall be deemed as common technical features disclosed in the prior art.

[0043] In the following examples, raw materials or processing techniques, unless otherwise specified, are conventional commercially available raw materials or conventional processing techniques in the art.

[0044] Embodiment 1:

[0045] This embodiment provides a method for preparing a cyan phosphor excited by violet light, the steps of which are as follows:

[0046] 1. Weigh 1 g of raw material powders of CaCO3, Lu2O3, ZrO2, Al2O3, Ga2O3, and CeO2 according to the stoichiometric ratio to obtain a raw material mixture.

[0047] 2. Grind the above raw material mixture in an agate mortar for 30 to 60 minutes. After the materials are evenly mixed, load the mixture into an alumina crucible and place it in a reducing atmosphere of a hydrogen and nitrogen mixture (a mixed gas of 5% by volume H2 and 95% by volume N2) for calcination at 1500°C for 4 hours, then cool to room temperature to obtain the target product.

[0048] 3. Use a fluorescence spectrometer to test the spectral properties of the phosphor in the system, such as Figure 1 As shown. The results show that the phosphor of this system has a wide excitation band with a peak near 410nm and a high spectral peak, which can match well with the commercial ultraviolet light chip. Under the excitation of a 410nm violet light source, the phosphor emits bright cyan light, and the emission spectrum consists of a wide emission band (450-700nm) with a peak at 477nm.

[0049] The ultraviolet excited Ce obtained in this example 3+ The general formula of doped cyan emitting phosphor is Ca2LuZr2Al 1.5 Ga 1.5 O 12 :xCe 3+ , where x=0.02.

[0050] Embodiment 2:

[0051] This embodiment provides a method for preparing a cyan phosphor excited by violet light, the steps of which are as follows:

[0052] 1. Weigh 1 g of raw material powders of CaCO3, Lu2O3, ZrO2, Al2O3, Ga2O3, and CeO2 according to the stoichiometric ratio to obtain a raw material mixture.

[0053] 2. Grind the above raw material mixture in an agate mortar for 30 to 60 minutes. After the materials are evenly mixed, load the mixture into an alumina crucible and place it in a reducing atmosphere of a hydrogen and nitrogen mixture (a mixed gas of 5% by volume H2 and 95% by volume N2) for calcination at 1600°C for 5 hours, then cool to room temperature to obtain the target product.

[0054] 3. Use a fluorescence spectrometer to test the spectral properties of the phosphor in the system, such as Figure 1 As shown. The results show that the phosphor of this system has a wide excitation band with a peak value near 410nm and a high spectral peak, which can match well with the commercial ultraviolet light chip. Under the excitation of a 410nm violet light source, the phosphor emits bright cyan light, and the emission spectrum consists of a wide emission band (450-700nm) with a peak value at 483nm.

[0055] The ultraviolet excited Ce obtained in this example 3+ The general formula of doped cyan emitting phosphor is Ca2LuZr2Al 1.5 Ga 1.5 O 12 :xCe 3+ , where x = 0.03.

[0056] Embodiment 3:

[0057] This embodiment provides a method for preparing a cyan phosphor excited by violet light, the steps of which are as follows:

[0058] 1. Weigh 1 g of raw material powders of CaCO3, Lu2O3, ZrO2, Al2O3, Ga2O3, and CeO2 according to the stoichiometric ratio to obtain a raw material mixture.

[0059] 2. Grind the above raw material mixture in an agate mortar for 30 to 60 minutes. After the materials are evenly mixed, load the mixture into an alumina crucible and place it in a reducing atmosphere of a hydrogen and nitrogen mixture (a mixed gas of 5% by volume H2 and 95% by volume N2) for calcination at 1400°C for 8 hours, then cool to room temperature to obtain the target product.

[0060] 3. Use a fluorescence spectrometer to test the spectral properties of the phosphor in the system, such as Figure 1 As shown. The results show that the phosphor of this system has a wide excitation band with a peak near 410nm and a high spectral peak, which can match well with the commercial ultraviolet light chip. Under the excitation of a 410nm violet light source, the phosphor emits bright cyan light, and the emission spectrum consists of a wide emission band (450-700nm) with a peak at 484nm.

[0061] The ultraviolet excited Ce obtained in this example 3+ The general formula of doped cyan emitting phosphor is Ca2LuZr2Al 1.5 Ga 1.5 O 12 :xCe 3+ , where x=0.04.

[0062] Embodiment 4:

[0063] This embodiment provides a method for preparing a cyan phosphor excited by violet light, the steps of which are as follows:

[0064] 1. Weigh 1 g of raw material powders of CaCO3, Lu2O3, ZrO2, Al2O3, Ga2O3, and CeO2 according to the stoichiometric ratio to obtain a raw material mixture.

[0065] 2. Grind the above raw material mixture in an agate mortar for 30 to 60 minutes. After the materials are evenly mixed, load the mixture into an alumina crucible and place it in a reducing atmosphere of a hydrogen and nitrogen mixture (a mixed gas of 5% by volume H2 and 95% by volume N2) for calcination at 1450°C for 8 hours, then cool to room temperature to obtain the target product.

[0066] 3. Use a fluorescence spectrometer to test the spectral properties of the phosphor in the system, such as Figure 1As shown. The results show that the phosphor of this system has a wide excitation band with a peak near 410nm and a high spectral peak, which can match well with the commercial ultraviolet light chip. Under the excitation of a 410nm violet light source, the phosphor emits bright cyan light, and the emission spectrum consists of a wide emission band (450-700nm) with a peak at 485nm.

[0067] The ultraviolet excited Ce obtained in this example 3+ The general formula of doped cyan emitting phosphor is Ca2LuZr2Al 1.5 Ga 1.5 O 12 :xCe 3+ , where x=0.05.

[0068] Embodiment 5:

[0069] This embodiment provides a method for preparing a cyan phosphor excited by violet light, the steps of which are as follows:

[0070] 1. Weigh 1 g of raw material powders of CaCO3, Lu2O3, ZrO2, Al2O3, Ga2O3, and CeO2 according to the stoichiometric ratio to obtain a raw material mixture.

[0071] 2. Grind the above raw material mixture in an agate mortar for 30 to 60 minutes. After the materials are evenly mixed, load the mixture into an alumina crucible and place it in a reducing atmosphere of a hydrogen and nitrogen mixture (a mixed gas of 5% by volume H2 and 95% by volume N2) for calcination at 1300°C for 3 hours, then cool to room temperature to obtain the target product.

[0072] 3. Use a fluorescence spectrometer to test the spectral properties of the phosphor in the system, such as Figure 1 As shown. The results show that the phosphor of this system has a wide excitation band with a peak near 410nm and a high spectral peak, which can match well with the commercial ultraviolet light chip. Under the excitation of a 410nm violet light source, the phosphor emits bright cyan light, and the emission spectrum consists of a wide emission band (450-700nm) with a peak at 488nm.

[0073] The ultraviolet excited Ce obtained in this example 3+ The general formula of doped cyan emitting phosphor is Ca2LuZr2Al 1.5 Ga 1.5 O 12 :xCe 3+ , where x = 0.06.

[0074] Embodiment 6:

[0075] This embodiment provides a method for preparing a cyan phosphor excited by violet light, the steps of which are as follows:

[0076] 1. Weigh 1 g of raw material powders of CaCO3, Lu2O3, ZrO2, Al2O3, Ga2O3, and CeO2 according to the stoichiometric ratio to obtain a raw material mixture.

[0077] 2. Grind the above raw material mixture in an agate mortar for 30 to 60 minutes. After the materials are evenly mixed, load the mixture into an alumina crucible and place it in a reducing atmosphere of a hydrogen and nitrogen mixture (a mixed gas of 5% by volume H2 and 95% by volume N2) for calcination at 1350°C for 6 hours, then cool to room temperature to obtain the target product.

[0078] 3. Use a fluorescence spectrometer to test the spectral properties of the phosphor in the system, such as Figure 1 As shown. The results show that the phosphor of this system has a wide excitation band with a peak value near 410nm and a high spectral peak, which can match well with the commercial ultraviolet light chip. Under the excitation of a 410nm violet light source, the phosphor emits bright cyan light, and the emission spectrum consists of a wide emission band (450-700nm) with a peak value at 489nm.

[0079] The ultraviolet excited Ce obtained in this example 3+ The general formula of doped cyan emitting phosphor is Ca2LuZr2Al 1.5 Ga 1.5 O 12 :xCe 3+ , where x = 0.07.

[0080] The raw material ratios, reaction conditions, and related properties of the cyan phosphors excited by violet light in Examples 1 to 6 are shown in Table 1.

[0081] Table 1 shows the raw material ratios, reaction conditions, and related properties of the cyan phosphors excited by violet light in Examples 1 to 6.

[0082]

[0083]

[0084] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and 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 present invention should be within the scope of protection of the present invention.

Claims

1. A cyan fluorescent material for violet light-excited solar LED, characterized in that: The chemical formula of this fluorescent material is Ca2LuZr2Al 1.5 Ga 1.5 O 12 :xCe 3+ , where 0.02≤x≤0.

07.

2. The cyan fluorescent material for violet light-excited solar LED according to claim 1, characterized in that: x＝0.02、0.03、0.04、0.05、0.06、0.07。 3. The cyan fluorescent material for violet light-excited solar LED according to claim 1, characterized in that: The cyan fluorescent material for the violet light excited solar LED is a powdery material.

4. The cyan fluorescent material for violet light-excited solar LED according to claim 1, characterized in that: The excitation spectrum range of the cyan fluorescent material for the violet light-excited solar LED covers 300 to 450 nm, the emission spectrum range of the cyan fluorescent material for the violet light-excited solar LED covers 400 to 700 nm, and the central emission wavelength is located at 484 nm.

5. A method for preparing a cyan fluorescent material for a violet light-excited solar LED as claimed in any one of claims 1 to 4, characterized in that: The following steps are involved: (1) weighing raw material powders of a calcium source compound, a lutetium source compound, a zirconium source compound, an aluminum source compound, a gallium source compound, and a cerium source compound according to a stoichiometric ratio of a chemical expression to obtain a mixed material; (2) grinding and mixing the mixed material obtained in step (1) to obtain a ground raw material powder; (3) Sintering the ground raw material powder obtained in step (2), and then cooling it to room temperature to finally obtain the cyan fluorescent material excited by purple light.

6. The method for preparing a cyan fluorescent material for a violet light-excited solar LED according to claim 5, characterized in that: In step (1), the calcium source compound is a carbonate containing Ca, the lutetium source compound is an oxide containing Lu, the zirconium source compound is an oxide containing Zr, the aluminum source compound is an oxide containing Al, the gallium source compound is an oxide containing Ga, and the cerium source compound is an oxide containing Ce.

7. The method for preparing a cyan fluorescent material for a violet light-excited solar LED according to claim 5, characterized in that: In step (3), the sintering conditions are: sintering in a reducing atmosphere in one step, the sintering temperature is 1000-1600° C., and the sintering time is 2-12 hours.

8. The method for preparing a cyan fluorescent material for a violet light-excited solar LED according to claim 5, characterized in that: In step (3), during sintering, the reducing atmosphere is selected from a mixed gas of H2 and N2.

9. The method for preparing a cyan fluorescent material for a violet light-excited solar LED according to claim 5, characterized in that: In step (2), the grinding time of the mixture is 5 to 120 minutes.

10. An application of the cyan fluorescent material for violet light excited solar LED as claimed in any one of claims 1 to 4, characterized in that: The cyan fluorescent material for the violet light-excited sunlight-like LED is used to prepare white light LED, sunlight-like LED and full-spectrum LED.

Images