A high-efficiency nitrogen oxide deep red fluorescent material excited by purple light, and a preparation method and application thereof

Abstract

This invention relates to a high-efficiency deep red fluorescent material of oxynitride excited by violet light, its preparation method, and its applications. The chemical formula of the high-efficiency deep red fluorescent material of oxynitride is Ca. 12‑x Al9Si 11 Lu3O 28 N 16 : x Eu 2+ , where 0.02≤ x ≤0.06. Compared with the prior art, the present invention provides a co-doped violet light-excited high-efficiency deep red fluorescent powder with a wide excitation band, which can generate deep red emission with a center wavelength in the range of 600-800 nm under violet light excitation. The material achieves an extremely high level of quantum efficiency and also exhibits excellent thermal stability. The dual advantages of these two key properties significantly enhance the application value of the material.

Description

Technical Field

[0001] This invention belongs to the field of fluorescent materials technology, and in particular relates to a high-efficiency deep red fluorescent material of oxynitride excited by violet light, its preparation method and application. Background Technology

[0002] Currently used lighting fixtures such as incandescent lamps and fluorescent lamps have obvious defects, while white LEDs have the advantages of small size, fast response, long life, low energy consumption, and environmental protection, and have become the mainstream lighting method.

[0003] In the spectral engineering of white LEDs, CaAlSiN3:Eu 2+ It is the core material that determines the "deep red dimension": it is efficiently excited under blue light (440-470 nm), its emission peak can be finely adjusted in the 630-670 nm range with the crystal field, and it has a wide bandwidth, which can continuously fill the energy gap of 600-700 nm, thus advancing white light from "able to light" to the color quality stage of "able to reproduce". In synergy with YAG:Ce in blue light chip architecture, it significantly improves the overall CRI and greatly increases R9 (deep red color rendering index), meeting the needs of blood / skin color sensitive scenarios such as museums and medical settings; in the ultraviolet chip route, it can achieve full-spectrum white light with a programmable color temperature of 2700-6500 K when combined with green and blue phosphors; in medical surgical lighting, it enhances the reproduction and contrast of hemoglobin-related bands with a stable "deep red anchor point", significantly improving tissue resolution and bleeding visualization, and its excellent thermochemical stability reduces color drift under long-term illumination, balancing high color rendering and clinical reliability. In summary, CaAlSiN3:Eu 2+ "Deep red gain + stability endorsement" constitutes a key element in contemporary high-quality white LED formulations.

[0004] As inorganic solids exhibiting characteristics of both oxides and nitrides, oxynitrides introduce an adjustable O / N ratio into the same [Si / Al(O,N)4] tetrahedral framework, achieving a trade-off and coupling of "strong crystal field and high stability" at the crystal chemistry level. Compared to pure oxides, the enhanced local crystal field allows for the activation of divalent and trivalent rare-earth elements (such as Eu) to activate their respective centers. 2+ Ce 3+This approach achieves higher emission efficiency and less thermal quenching. Compared to pure nitrides, partial oxidation significantly improves hydrolysis resistance and process accessibility, while lowering the synthesis temperature (typical solid-state or carbothermal reduction ammoniation can be achieved at around 1400℃, and can also be supplemented with reaction atmosphere control, SPS, etc.). Representative systems include beta-SiAlON and LaSi3N5O, which exhibit broadband absorption in the 380-420 nm region, making them suitable for near-ultraviolet / blue LEDs and providing spectral and thermal margins for high-power LED lighting. Through lattice composition and defect engineering, emission can be extended from green-yellow to orange-red, catering to the needs of various scenarios such as high color rendering white light, wide color gamut display, plant lighting, and in-situ optical sensing. Overall, nitrides, with their programmable anion and cation frameworks, provide a new generation of luminescent matrix platform that is "spectrally designable, process-accessible, and environmentally sustainable."

[0005] However, existing oxynitride luminescent substrates still face several bottlenecks in violet light chip applications, such as insufficient matching between excitation efficiency and chip wavelength, and limitations in luminescent performance due to trade-offs between bandwidth and color gamut. Therefore, to meet the urgent needs of violet-excited white LEDs, violet-excited solar-like LEDs, and violet-excited full-spectrum LEDs, new deep red phosphors with wide excitation bands still need to be developed. Summary of the Invention

[0006] The purpose of this invention is to overcome the defects of the prior art by providing a high-efficiency deep red fluorescent material of nitride excited by violet light, its preparation method and application. The prepared deep red fluorescent material has a wide excitation band and can emit red light with a center wavelength between 600-800 nm under violet light excitation.

[0007] The objective of this invention can be achieved through the following technical solutions: One of the technical solutions of this invention is to provide a high-efficiency deep red oxynitride fluorescent material excited by violet light, wherein the chemical formula of the high-efficiency deep red oxynitride fluorescent material is Ca. 12-x Al9Si 11 Lu3O 28 N 16 : x Eu 2+ , 0.02≤ x ≤0.06.

[0008] In some specific embodiments, the x The molar ratio of Ca, Lu and Eu is 11.98:3:0.02.

[0009] In some specific embodiments, the excitation spectrum of the deep red fluorescent material covers the range of 200-600 nm.

[0010] In some specific embodiments, the optimal excitation wavelength of the deep red fluorescent material is 451 nm.

[0011] In some specific embodiments, the emission spectrum wavelength range of the deep red fluorescent material covers 600-800 nm.

[0012] In some specific embodiments, the optimal central emission wavelength of the deep red fluorescent material is located at 675 nm.

[0013] In this invention, the deep red fluorescent material has a broad excitation spectral band.

[0014] The second technical solution of the present invention is to provide a method for preparing a high-efficiency deep red oxynitride fluorescent material excited by violet light as described in one of the above technical solutions, comprising the following steps: S1. Weighing: Weigh the calcium source compound, aluminum source compound, silicon source compound, lutetium source compound, and europium source compound according to the stoichiometric ratio to obtain the raw material powders; S2. Grinding to mix the raw material powders evenly to obtain a mixture; S3. Under inert protective gas and slightly positive pressure conditions, the mixture is sintered at high temperature and cooled to obtain a high-efficiency deep red fluorescent material of oxynitride.

[0015] In some specific embodiments, in step S1, the calcium source compound is a nitrogen-containing calcium source compound, the lutetium source compound is an oxygen-containing lutetium source compound, the aluminum source compound is composed of a nitrogen-containing aluminum source compound and an oxygen-containing aluminum source compound, the silicon source compound is composed of a nitrogen-containing silicon source compound and an oxygen-containing silicon source compound, and the europium source compound is composed of a nitrogen-containing europium source compound and an oxygen-containing europium source compound.

[0016] In some specific embodiments, in step S1, the calcium source compound is Ca3N2; The aluminum source compounds are AlN and Al2O3; The silicon source compounds are Si3N4 and SiO2; The lutetium source compound is Lu2O3; The europium source compounds are EuN and Eu2O3.

[0017] In some specific methods, step S1 involves weighing each raw material in a closed space to prevent the raw materials from coming into contact with air and causing oxidation.

[0018] In some specific methods, the grinding time for step S2 is 5-120 min.

[0019] In some specific methods, the S3 step involves high-temperature sintering at a temperature of 1000-1900℃ for 2-24 hours.

[0020] In some specific methods, in step S3, the high-temperature sintering temperature is 1200-1700℃, and the high-temperature sintering time is 5-12 h.

[0021] In some specific methods, in step S3, the inert protective gas is N2.

[0022] In some specific methods, in step S3, the inert protective gas is high-purity 99.999% N2.

[0023] In some specific methods, the pressure under the slightly positive pressure condition in step S3 is 0.25~0.35MPa.

[0024] In some specific methods, the pressure under the micro-positive pressure condition in step S3 is 0.3 MPa.

[0025] In this invention, a vacuum is drawn before the inert protective gas is introduced, and the system pressure is maintained at 0.25~0.35MPa, i.e., slightly positive pressure, during high-temperature sintering. The phosphor (fluorescent material) is brought to its optimal state according to the chemical formula of the fluorescent material, using slightly positive pressure.

[0026] This invention proposes a novel deep-red emitting oxynitride matrix fluorescent material Ca for violet light chips. 12- x Al9Si 11 Lu3O 28 N 16 : x Eu 2+ (Eu) 2+ (Activation), its luminescence mechanism originates from Eu 2+ The 4f↔5d energy level transition is extremely sensitive to the crystal field, therefore the emission peak position and bandwidth can be programmably controlled through matrix composition and structural design. This invention utilizes different amounts of Lu doping... 3+ Ions, altered Eu 2+ The crystal field environment in which the ions are located regulates Eu. 2+ The local coordination environment of Eu gives the material environmental adaptability, that is, it maintains stability under high temperature and humidity, and also affects the local coordination environment of Eu. 2+ The emission characteristics enable redshift.

[0027] This invention is based on the precise design of the types, valence states, and lattice sites of doped ions, achieving multi-dimensional optimization of the electronic structure of materials, as well as optimization of emission and laser spectral wavelength ranges, and possessing the advantage of stable physicochemical properties.

[0028] The high-efficiency oxynitride deep red fluorescent material excited by violet light of the present invention exhibits an ultra-wide excitation band, effectively absorbing and covering approximately 200-600 nm, with a preferred excitation wavelength of 451 nm, achieving efficient excitation and output of deep red light in the near-ultraviolet / violet region.

[0029] In terms of the manufacturing process, this invention adopts a sintering window that combines micro-positive pressure and high temperature to ensure high crystal quality of the material. It also introduces heterovalent / equivalent cation site engineering to improve crystal field strength and radiation probability, significantly enhancing spectral intensity and stability. This provides a novel deep red "anchor" phosphor solution for high color rendering, high reliability white LEDs and related optoelectronic applications.

[0030] The deep red fluorescent material of this invention can be prepared by solid-state reaction method, which has the characteristics of simple preparation process and is conducive to industrial production. It can also be well matched with existing violet light chips, meet the needs of commercial market, and can be used as a good candidate material for the wide application of violet light excited white LED, violet light excited solar LED, and violet light excited full-spectrum LED.

[0031] The third technical solution of the present invention is to provide an application of the purple light-excited oxynitride deep red fluorescent material as described in the second technical solution above in the preparation of purple light-excited LEDs.

[0032] In some specific embodiments, the violet-excited LED includes a violet-excited white LED, a violet-excited sunlight LED, and a violet-excited full-spectrum LED.

[0033] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention provides a co-doped, high-efficiency violet-excited deep red phosphor with a broad excitation band and an effective absorption range covering 200-600 nm. The resulting phosphor emits deep red light with a center wavelength of 600-800 nm under 400 nm violet light excitation, with an optimal emission spectrum of 675 nm, and exhibits extremely high quantum efficiency. This invention achieves improvements in key indicators such as spectral position, quantum efficiency, and environmental compatibility.

[0034] 2. This invention provides a solution using Lu 3+ and Eu 2+ The novel structure of the doped deep red fluorescent powder achieves a redshift in emission and has the advantage of stable physicochemical properties.

[0035] 3. This invention provides a high-efficiency deep red phosphor with a wide excitation band, which is prepared by solid-state reaction method. It has the characteristics of simple preparation process and is conducive to industrial production. It can meet the urgent needs of violet light-excited white LEDs, violet light-excited solar LEDs, and violet light-excited full-spectrum LEDs. It can be used as a good candidate material for the widespread application of white LEDs and has broad application prospects. Attached Figure Description

[0036] Figure 1 The photoexcitation emission spectrum of the deep red phosphor in Comparative Example 1 of this invention is shown.

[0037] Figure 2 This is a quantum efficiency diagram of the deep red phosphor in Comparative Example 1 of the present invention.

[0038] Figure 3 This is a thermal stability diagram of the deep red phosphor in Comparative Example 1 of the present invention.

[0039] Figure 4 This is the photoexcitation emission spectrum of the deep red phosphor in Example 1 of the present invention.

[0040] Figure 5 This is a quantum efficiency diagram of the deep red phosphor in Example 1 of the present invention.

[0041] Figure 6 This is a thermal stability diagram of the deep red phosphor in Example 1 of the present invention. Detailed Implementation

[0042] 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.

[0043] Unless otherwise specified in this technical solution, the component model, material name, connection structure, control method, algorithm, and other features are considered to be common technical features disclosed in the prior art.

[0044] 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.

[0045] Example 1 This embodiment provides a deep red fluorescent powder material excited by violet light, whose chemical formula is Ca. 12- x Al9Si 11 Lu3O 28 N 16 : x Eu 2+ ,inx = 0.02, and its preparation method is as follows: (1) Weigh Ca3N2, AlN, and Al2O according to the stoichiometric ratio. 3、 Si3N4, SiO2, Lu2O3, EuN, Eu2O3. 20g of raw material powder, with the following mass ratio: Ca3N2, AlN, Al2O3. 3、 Si3N4, SiO2, Lu2O3, EuN, Eu2O3= 7.6432:1.5875:3.9492:3.0186:4.6544:7.7064:0.0214:0.0227.

[0046] (2) The above raw material mixture was placed in an agate mortar in a glove box and ground for 60 minutes. After the material was mixed evenly, the mixture was loaded into a molybdenum crucible and calcined at 1200°C for 5 h in a nitrogen atmosphere. The calcination process was carried out under a slightly positive pressure (0.3 MPa). Then it was cooled to room temperature to obtain the target product.

[0047] The spectral properties of the phosphor in this system were tested using a fluorescence spectrometer, such as... Figure 4 As shown in the figure. The results indicate that the phosphor in this system exhibits a broad excitation band with a peak at approximately 451 nm, and its relative absorption intensity exceeds 95% under 400 nm excitation, demonstrating good spectral matching with commercially available violet light chips. Under 400 nm violet light excitation, the phosphor emits bright deep red light, with an emission spectral peak at 675 nm.

[0048] The quantum efficiency of this system under violet light excitation was measured using an absolute quantum efficiency testing system (AQS-1000, EVERFINE). Figure 5 As shown. The results indicate that Lu 3+ The deep red phosphor material of oxynitride prepared by the ion-doping strategy combines novel violet light excitation characteristics with extremely high quantum efficiency (internal quantum efficiency of 86.97% and external quantum efficiency of 79.22%), effectively overcoming the bottlenecks of traditional deep red phosphor materials in excitation compatibility and luminescence performance. The external quantum efficiency is higher than that of Hilde CaAlSiN3:Eu 2+ The percentage of commercial powder increased from 59.41% to 79.22%, representing a significant performance breakthrough.

[0049] The thermal stability of this system under 400 nm violet light excitation was tested using fluorescence spectroscopy, such as... Figure 6 As shown. The results indicate that Lu 3+ The violet-excited oxynitride deep red fluorescent material prepared by ion doping retains 88.65% of its initial weight at 120℃, demonstrating outstanding thermal stability and providing a reliable guarantee for its application at high temperatures.

[0050] Example 2 This embodiment provides a deep red fluorescent powder material excited by violet light, whose chemical formula is Ca. 12- x Al9Si 11 Lu3O 28 N 16 : x Eu 2+ ,in x = 0.04, and its preparation method is as follows: (1) Weigh Ca3N2, AlN, and Al2O according to the stoichiometric ratio. 3、 20g of raw material powders containing Si3N4, SiO2, Lu2O3, EuN, and Eu2O3, in the following mass ratio: Ca3N2, AlN, Al2O3. 3、 Si3N4, SiO2, Lu2O3, EuN, Eu2O3= 7.6185:1.5850:3.9430:3.0138:4.6471:7.6943:0.0427:0.0453.

[0051] (2) The above raw material mixture was placed in an agate mortar in a glove box and ground for 60 minutes. After the material was mixed evenly, the mixture was loaded into a molybdenum crucible and calcined at 1200°C for 5 h in a nitrogen atmosphere. The calcination process was carried out under a slightly positive pressure (0.3 MPa). Then it was cooled to room temperature to obtain the target product.

[0052] The spectral properties of the phosphor in this system were tested using a fluorescence spectrometer. The results showed that the phosphor exhibited a broad excitation band with a peak at approximately 449 nm, and its relative absorption intensity under 400 nm excitation exceeded 95%, demonstrating good spectral matching with commercially available violet light chips. Under 400 nm violet light excitation, the phosphor emitted bright deep red light, with an emission spectral peak at 675 nm.

[0053] Example 3 This embodiment provides a deep red fluorescent powder material excited by violet light, whose chemical formula is Ca. 12- x Al9Si 11 Lu3O 28 N 16 : x Eu 2+ ,in x = 0.06, and its preparation method is as follows: (1) Weigh Ca3N2, AlN, and Al2O according to the stoichiometric ratio. 3、20g of raw material powders containing Si3N4, SiO2, Lu2O3, EuN, and Eu2O3, in the following mass ratio: Ca3N2, AlN, Al2O3. 3、 Si3N4, SiO2, Lu2O3, EuN, Eu2O3= 7.5938:1.5826:3.9368:3.0091:4.6398:7.6823:0.0640:0.0679.

[0054] (2) The above raw material mixture was placed in an agate mortar in a glove box and ground for 60 minutes. After the material was mixed evenly, the mixture was loaded into a molybdenum crucible and calcined at 1200 °C for 5 h in a nitrogen atmosphere. The calcination process was carried out under a slight positive pressure (0.3 MPa). Then it was cooled to room temperature to obtain the target product.

[0055] The spectral properties of the phosphor in this system were tested using a fluorescence spectrometer. The results showed that the phosphor exhibited a broad excitation band with a peak at approximately 451 nm, and its relative absorption intensity under 400 nm excitation exceeded 95%, demonstrating good spectral matching with commercially available violet light chips. Under 400 nm violet light excitation, the phosphor emitted bright deep red light, with an emission spectral peak at 675 nm.

[0056] Example 4 This embodiment provides a deep red fluorescent powder material excited by violet light, whose chemical formula is Ca. 12- x Al9Si 11 Lu3O 28 N 16 : x Eu 2+ ,in x = 0.02, and its preparation method is as follows: (1) Weigh Ca3N2, AlN, and Al2O according to the stoichiometric ratio. 3、 Si3N4, SiO2, Lu2O3, EuN, Eu2O3. 20g of raw material powder, with the following mass ratio: Ca3N2, AlN, Al2O3. 3、 Si3N4, SiO2, Lu2O3, EuN, Eu2O3= 7.6432:1.5875:3.9492:3.0186:4.6544:7.7064:0.0214:0.0227.

[0057] (2) The above raw material mixture was placed in an agate mortar in a glove box and ground for 60 minutes. After the material was mixed evenly, the mixture was loaded into a molybdenum crucible and calcined at 1500°C for 8 hours in a nitrogen atmosphere. The calcination process was carried out under a slightly positive pressure (0.3 MPa). Then it was cooled to room temperature to obtain the target product.

[0058] The results showed that the luminescence properties of the phosphor in Example 4 were similar to those in Example 1, with only a decrease in spectral intensity.

[0059] Example 5 This embodiment provides a deep red fluorescent powder material excited by violet light, whose chemical formula is Ca. 12- x Al9Si 11 Lu3O 28 N 16 : x Eu 2+ ,in x = 0.02, and its preparation method is as follows: (1) Weigh Ca3N2, AlN, and Al2O according to the stoichiometric ratio. 3、 Si3N4, SiO2, Lu2O3, EuN, Eu2O3. 20g of raw material powder, with the following mass ratio: Ca3N2, AlN, Al2O3. 3、 Si3N4, SiO2, Lu2O3, EuN, Eu2O3= 7.6432:1.5875:3.9492:3.0186:4.6544:7.7064:0.0214:0.0227.

[0060] (2) The above raw material mixture was placed in an agate mortar in a glove box and ground for 60 minutes. After the material was mixed evenly, the mixture was loaded into a molybdenum crucible and calcined at 1700°C for 12 h in a nitrogen atmosphere. The calcination process was carried out under a slightly positive pressure (0.3 MPa). Then it was cooled to room temperature to obtain the target product.

[0061] The results showed that the luminescence properties of the phosphor in Example 5 were similar to those in Example 1, with only a decrease in spectral intensity.

[0062] Example 6 This embodiment provides a deep red fluorescent powder material excited by violet light, whose chemical formula is Ca. 12- x Al9Si 11 Lu3O 28 N 16 : x Eu 2+ ,in x = 0.04, and its preparation method is as follows: (1) Weigh Ca3N2, AlN, and Al2O according to the stoichiometric ratio. 3、 20g of raw material powders containing Si3N4, SiO2, Lu2O3, EuN, and Eu2O3, in the following mass ratio: Ca3N2, AlN, Al2O3. 3、 Si3N4, SiO2, Lu2O3, EuN, Eu2O3= 7.6185:1.5850:3.9430:3.0138:4.6471:7.6943:0.0427:0.0453.

[0063] (2) The above raw material mixture was placed in an agate mortar in a glove box and ground for 60 minutes. After the material was mixed evenly, the mixture was loaded into a molybdenum crucible and calcined at 1500°C for 8 hours in a nitrogen atmosphere. The calcination process was carried out under a slightly positive pressure (0.3 MPa). Then it was cooled to room temperature to obtain the target product.

[0064] The results showed that the luminescence properties of the phosphor in Example 6 were similar to those in Example 2, except that the spectral intensity was reduced.

[0065] Example 7 This embodiment provides a deep red fluorescent powder material excited by violet light, whose chemical formula is Ca. 12- x Al9Si 11 Lu3O 28 N 16 : x Eu 2+ ,in x = 0.04, and its preparation method is as follows: (1) Weigh Ca3N2, AlN, and Al2O according to the stoichiometric ratio. 3、 20g of raw material powders containing Si3N4, SiO2, Lu2O3, EuN, and Eu2O3, in the following mass ratio: Ca3N2, AlN, Al2O3. 3、 Si3N4, SiO2, Lu2O3, EuN, Eu2O3= 7.6185:1.5850:3.9430:3.0138:4.6471:7.6943:0.0427:0.0453.

[0066] (2) The above raw material mixture was placed in an agate mortar in a glove box and ground for 60 minutes. After the material was mixed evenly, the mixture was loaded into a molybdenum crucible and calcined at 1700°C for 12 h in a nitrogen atmosphere. The calcination process was carried out under a slightly positive pressure (0.3 MPa). Then it was cooled to room temperature to obtain the target product.

[0067] The results showed that the luminescence properties of the phosphor in Example 7 were similar to those in Example 2, with only a decrease in spectral intensity.

[0068] Example 8 This embodiment provides a deep red fluorescent powder material excited by violet light, whose chemical formula is Ca. 12- x Al9Si 11 Lu3O 28 N 16 : x Eu 2+ Where x = 0.06, the specific preparation method is as follows: (1) Weigh Ca3N2, AlN, and Al2O according to the stoichiometric ratio. 3、 20g of raw material powders containing Si3N4, SiO2, Lu2O3, EuN, and Eu2O3, in the following mass ratio: Ca3N2, AlN, Al2O3. 3、 Si3N4, SiO2, Lu2O3, EuN, Eu2O3= 7.5938:1.5826:3.9368:3.0091:4.6398:7.6823:0.0640:0.0679.

[0069] (2) The above raw material mixture was placed in an agate mortar in a glove box and ground for 60 minutes. After the material was mixed evenly, the mixture was loaded into a molybdenum crucible and calcined at 1500 °C for 8 h in a nitrogen atmosphere. The calcination process was carried out under a slight positive pressure (0.3 MPa). Then it was cooled to room temperature to obtain the target product.

[0070] The results showed that the luminescence properties of the phosphor in Example 8 were similar to those in Example 3, except that the spectral intensity was reduced.

[0071] Example 9 This embodiment provides a deep red fluorescent powder material excited by violet light, whose chemical formula is Ca. 12- x Al9Si 11 Lu3O 28 N 16 : x Eu 2+ ,in x = 0.06, and its preparation method is as follows: (1) Weigh Ca3N2, AlN, and Al2O according to the stoichiometric ratio. 3、 20g of raw material powders containing Si3N4, SiO2, Lu2O3, EuN, and Eu2O3, in the following mass ratio: Ca3N2, AlN, Al2O3. 3、Si3N4, SiO2, Lu2O3, EuN, Eu2O3= 7.5938:1.5826:3.9368:3.0091:4.6398:7.6823:0.0640:0.0679.

[0072] (2) The above raw material mixture was placed in an agate mortar in a glove box and ground for 60 minutes. After the material was mixed evenly, the mixture was loaded into a molybdenum crucible and calcined at 1700 °C for 12 h in a nitrogen reducing atmosphere. The calcination process was carried out under a slight positive pressure (0.3 MPa). Then it was cooled to room temperature to obtain the target product.

[0073] The results showed that the luminescence properties of the phosphor in Example 9 were similar to those in Example 3, except that the spectral intensity was reduced.

[0074] Comparative Example 1 This comparative example provides a fluorescent powder material that does not introduce Lu. 3+ To satisfy the stoichiometric relationship between electroneutrality and structure, its chemical expression is Ca. 15 Al6Si 14 O 28 N 16 : x Eu 2+ ,in x = 0.02, and its preparation method is as follows: (1) Weigh Ca3N2, AlN, and Al2O according to the stoichiometric ratio. 3、 Si3N4, SiO2, EuN, Eu2O3. 20g of raw material powder, with the following mass ratio: Ca3N2, AlN, Al2O3. 3、 Si3N4, SiO2, EuN, Eu2O3=8.4398:1.4019:1.7437:4.2651:4.1102:0.0189:0.0200.

[0075] (2) The above raw material mixture was placed in an agate mortar in a glove box and ground for 60 minutes. After the material was mixed evenly, the mixture was loaded into a molybdenum crucible and calcined at 1200°C for 5 h in a nitrogen atmosphere. The calcination process was carried out under a slightly positive pressure (0.3 MPa). Then it was cooled to room temperature to obtain the target product.

[0076] like Figure 1 As shown, the obtained phosphor is a deep red phosphor excited at 451 nm, with its optimal emission peak at 648 nm. In contrast, the deep red phosphor of Example 1, when excited by violet light at 400 nm, has an emission spectrum peak at 675 nm, with the emission light redshifted to 670-700 nm.

[0077] like Figure 2 As shown, the deep red phosphor prepared in Comparative Example 1 has an internal quantum efficiency of 85.13% and an external quantum efficiency of 70.83%.

[0078] like Figure 3 As shown, the deep red phosphor prepared in Comparative Example 1 weighed 88.2% of its initial weight at 120°C.

[0079] As can be seen, compared with Comparative Example 1, Example 1 has advantages over Comparative Example 1 due to Lu 3+ The introduction of this technology alters the local environment of the phosphor's luminescence center, resulting in a redshift and improved efficiency. Simultaneously, the material's external quantum efficiency and thermal stability are also improved to some extent.

[0080] Comparative Example 2 The steps are basically the same as in Example 1, except that the calcination process in this comparative example is carried out under normal pressure, and the product cannot be obtained by sintering in the end.

[0081] The preparation parameters and test results of Examples 1-3 are summarized in Table 1.

[0082] Table 1 Summary of preparation parameters and test results for Examples 1-3 Combination Figure 2 , 3 As shown, the quantum efficiency and thermal stability of the deep red fluorescent powder prepared in Example 1 were tested under violet light excitation. Under 400 nm violet light excitation, the external quantum efficiency of the deep red fluorescent material reached 79.22%, which is far superior to that of commercial CaAlSiN3 powder materials. The thermal stability also reached 88.65% at 120℃, demonstrating a certain degree of thermal stability.

[0083] In this invention, the chemical formula is Ca 12-x Al9Si 11 Lu3O 28 N 16 : x Eu 2+ In deep red fluorescent materials of oxynitrides, the requirement of 0.02 ≤ x ≤0.06, within a certain range, changes in composition do not significantly affect the excitation and emission wavelengths. If x is too low, Eu may be affected. 2+ Insufficient activation concentration leads to low luminescence efficiency; if x is too high, concentration quenching may cause fluorescence decay, meaning that at higher doping concentrations, Eu... 2+ They will quench each other's light emission, resulting in a decrease in emission intensity.

[0084] This invention modulates the local environment through the combination of different elements, enabling the material to maintain stability under high temperature and humidity, thus exhibiting environmental adaptability; by doping with Lu... 3+ It can effectively regulate Eu 2+ The emission wavelength can be adjusted to change the luminescence characteristics, thus enabling spectral modulation; high crystal quality and structural stability are ensured through high-temperature sintering and micro-positive pressure synthesis.

[0085] Based on this, the oxynitride deep red fluorescent material proposed in this invention has advantages over traditional nitride systems in terms of structural stability and environmental adaptability, as well as superior performance in terms of emission efficiency, thermal stability and spectral control capabilities.

[0086] 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 high-efficiency deep red fluorescent material of oxynitride excited by violet light, characterized in that, The chemical formula for the high-efficiency nitrogen oxide deep red fluorescent material is Ca. 12-x Al9Si 11 Lu3O 28 N 16 : x Eu 2+ , 0.02≤ x ≤0.

06.

2. The high-efficiency deep red oxynitride fluorescent material excited by violet light according to claim 1, characterized in that, The excitation spectrum of the high-efficiency oxynitride deep red fluorescent material covers the range of 200-600 nm.

3. The high-efficiency deep red oxynitride fluorescent material excited by violet light according to claim 2, characterized in that, The excitation wavelength of the high-efficiency oxynitride deep red fluorescent material is 451 nm.

4. The high-efficiency deep red oxynitride fluorescent material excited by violet light according to claim 1, characterized in that, The emission spectrum of the high-efficiency oxynitride deep red fluorescent material covers the wavelength range of 600-800 nm, with a central emission wavelength at 675 nm.

5. A method for preparing a high-efficiency deep red oxynitride fluorescent material excited by violet light as described in any one of claims 1-4, characterized in that, Includes the following steps: S1. Weigh the calcium source compound, aluminum source compound, silicon source compound, lutetium source compound, and europium source compound according to the stoichiometric ratio to obtain the raw material powders; S2. Grinding to mix the raw material powders evenly to obtain a mixture; S3. Under inert protective gas and slightly positive pressure conditions, the mixture is sintered at high temperature and cooled to obtain a high-efficiency deep red fluorescent material of oxynitride.

6. The method for preparing the violet-excited deep red fluorescent material of oxynitride according to claim 5, characterized in that, In step S1, the calcium source compound is a nitrogen-containing calcium source compound, the lutetium source compound is an oxygen-containing lutetium source compound, the aluminum source compound is composed of a nitrogen-containing aluminum source compound and an oxygen-containing aluminum source compound, the silicon source compound is composed of a nitrogen-containing silicon source compound and an oxygen-containing silicon source compound, and the europium source compound is composed of a nitrogen-containing europium source compound and an oxygen-containing europium source compound.

7. The method for preparing the violet-excited deep red fluorescent material of oxynitride according to claim 5, characterized in that, In step S1, the calcium source compound is Ca3N2; The aluminum source compounds are AlN and Al2O3; The silicon source compounds are Si3N4 and SiO2; The lutetium source compound is Lu2O3; The europium source compounds are EuN and Eu2O3.

8. The method for preparing the violet-excited deep red fluorescent material of oxynitride according to claim 5, characterized in that, In step S2, the grinding time is 5-120 min.

9. The method for preparing the violet-excited deep red fluorescent material of oxynitride according to claim 5, characterized in that, In step S3, the high-temperature sintering temperature is 1000-1900℃ and the time is 2-24 h. The inert protective gas is nitrogen; The pressure under slightly positive pressure conditions is 0.25~0.35MPa.

10. The application of a high-efficiency oxynitride deep red fluorescent material excited by violet light as described in any one of claims 1-4 in the preparation of violet-excited LEDs.

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