Near-ultraviolet and blue light high-efficiency excited red phosphor, preparation method and application thereof

Abstract

This invention discloses a red phosphor that can be efficiently excited by near-ultraviolet and blue light, its preparation method, and its applications, relating to the field of inorganic solid-state luminescent materials technology. The chemical formula of the red phosphor is Ca. 14‑x K x Ga 9.8‑x Ti x Zn6O 35 0.2Mn 4+ Where 0 < x ≤ 1, and 0.2 is Mn 4+ The molar amount of doping. This invention utilizes K... + -Ti 4+ Ca in ion-pair co-substituted matrix 2+ -Ga 3+ The site significantly improves the excitation efficiency of phosphors in the near-ultraviolet and blue light regions. The external quantum efficiency is ≥54% under 370nm near-ultraviolet light excitation and ≥43% under 460nm blue light excitation. The luminescence intensity remains above 88% of the room temperature at 150℃, and the water-thermal stability is excellent. Furthermore, the red phosphor can be used for plant lighting and facility agriculture, and has important application value in the field of plant supplemental lighting.

Description

Technical Field

[0001] This invention relates to the field of inorganic solid-state luminescent materials technology, and more particularly to a red phosphor that is efficiently excited by near-ultraviolet and blue light, its preparation method, and its application. Background Technology

[0002] With the rapid development of facility agriculture, artificial lighting and supplemental lighting technologies have become core technical means to overcome the limitations of natural light and improve crop yield and quality. The red light band (600-700nm) is a key spectral region for plant photosynthesis, root and stem development, flowering, and fruiting, and can significantly improve the net photosynthetic rate of plants, promoting increased crop yield and quality. Therefore, developing highly efficient red light-emitting materials adapted to plant growth is a key research focus in precision agriculture supplemental lighting technology.

[0003] Mn 4+ Activated oxide phosphors are considered ideal red light supplementary materials for plants because their emission spectrum is concentrated in the 650-800nm ​​deep red light region, which highly matches the absorption spectrum of plant chlorophyll and phytochromes. They also possess advantages such as high stability and tunable spectra. However, existing Mn... 4+ The activation of phosphors has significant technical defects: Mn 4+ The dd transition is a parity-forbidden transition, resulting in low excitation efficiency in the near-ultraviolet and blue light regions. Effective excitation is often limited to the shorter-wavelength ultraviolet region. This limitation makes traditional Mn... 4+ Phosphors cannot be effectively adapted to commercial near-ultraviolet (e.g., 370nm) and blue light (e.g., 460nm) LED chips; at the same time, the near-ultraviolet and blue light bands, which account for a large proportion of sunlight, cannot be effectively utilized by light conversion films, which seriously restricts their large-scale application in plant supplemental lighting LEDs and agricultural light conversion films.

[0004] Current technologies include schemes that employ ion substitution strategies to improve the excitation performance of phosphors, such as in Ca... 14 Zn6Ga 10 O 35 :Sb in Mn matrix 3+ Doping improves thermal quenching performance, but simultaneously improving the excitation efficiency in both near-ultraviolet and blue light bands remains a technical challenge that urgently needs to be addressed in this field. Summary of the Invention

[0005] The purpose of this invention is to provide a red phosphor that is efficiently excited by near-ultraviolet and blue light, as well as its preparation method and applications, to solve the current problems of Mn 4+ The problem of low excitation efficiency of activated phosphors in the near-ultraviolet and blue light regions.

[0006] To achieve the above objectives, this invention provides a red phosphor that is efficiently excited by near-ultraviolet and blue light, with the chemical formula: Ca14-x K x Ga 9.8-x Ti x Zn6O 35 0.2Mn 4+ ; Where 0 < x ≤ 1, and 0.2 is Mn 4+ The molar amount of doping.

[0007] Preferably, the value of x is in the range of 0.2 ≤ x ≤ 1.

[0008] Preferably, x is 0.2.

[0009] Preferably, the emission spectrum of the near-ultraviolet and blue light-efficiently excited red phosphor covers the wavelength range of 650 nm to 800 nm.

[0010] Preferably, the external quantum efficiency of the red phosphor, which is highly excited by near-ultraviolet and blue light, is ≥54% under 370nm near-ultraviolet light excitation and ≥43% under 460nm blue light excitation, is determined by the integrating sphere method at room temperature.

[0011] Preferably, the luminescence intensity of the red phosphor excited by near-ultraviolet and blue light remains at more than 88% of the luminescence intensity at room temperature under 150°C conditions.

[0012] This invention provides a method for preparing a red phosphor that is efficiently excited by near-ultraviolet and blue light, comprising the following steps: S1. Weigh out the calcium source, potassium source, gallium source, titanium source, zinc source, and manganese source according to the stoichiometric ratio; each of the calcium source, potassium source, gallium source, titanium source, zinc source, and manganese source is independently selected from oxides or carbonates; S2. Place the weighed calcium source, potassium source, gallium source, titanium source, zinc source and manganese source in a mortar, add the dispersion medium, and grind until they are evenly mixed to obtain a mixture. S3. Place the mixture in a crucible and sinter it in air at a constant temperature of 1100℃~1400℃ for 2h~6h to obtain the sintered product. S4. Cool the sintered product to room temperature, grind and pulverize it to obtain red phosphor.

[0013] Preferably, the dispersion medium is anhydrous ethanol; the amount of anhydrous ethanol added is based on the amount of calcium source, potassium source, gallium source, titanium source, zinc source and manganese source after complete impregnation and weighing.

[0014] Preferably, in S3, the temperature is increased to the sintering temperature at a heating rate of 2℃ / min to 5℃ / min.

[0015] This invention also provides the application of red phosphors that are highly efficient at being excited by near-ultraviolet and blue light, using the aforementioned red phosphors that are highly efficient at being excited by near-ultraviolet and blue light to prepare plant lighting devices for plant growth; the plant lighting devices include: pc-LED lighting devices and light-converting films; The pc-LED lighting device is encapsulated from phosphor and blue light chip; The light-converting film is prepared by combining phosphor with a polymer resin substrate; the polymer resin is one of polypropylene, epoxy resin and polydimethylsiloxane.

[0016] The present invention prepares red phosphors by high-temperature solid-state air sintering. The raw materials are inexpensive and readily available, free of precious metals and toxic or harmful substances. The preparation process is simple, reproducible, and suitable for industrial mass production.

[0017] In summary, the near-ultraviolet and blue light-efficiently excitable red phosphor, its preparation method, and its applications provided by this invention offer the following advantages compared to traditional technologies: (1) This invention uses K + -Ti 4+ After ion-pair co-substitution modification, the excitation efficiency of the red phosphor in the near-ultraviolet and blue light regions was significantly optimized; the external quantum efficiency under 370nm near-ultraviolet excitation increased from 35.8% to 54.6%, and the external quantum efficiency under 460nm blue light excitation increased from 25.0% to 43.9%, effectively solving the problem of traditional Mn 4+ Technical challenges of weak excitation of phosphors under near-ultraviolet and blue light; (2) The red phosphor prepared by the present invention can maintain 88.12% of the luminescence intensity at room temperature under a high temperature environment of 150℃. It has a weak thermal quenching effect and can be adapted to complex working conditions such as long-term operation of LED devices and high-temperature planting in greenhouses. (3) The phosphor provided by the present invention can still maintain 99.8% of the initial intensity after being treated in an environment of 85℃-85% relative humidity for 1000h, and has good water-thermal stability, making it suitable for high humidity agricultural greenhouse environments; (4) The blue and deep red light emitted by the PC-LED device prepared based on red phosphor can cover the absorption spectrum of chlorophyll and photosensitive pigments, which can effectively supplement the red and blue light components required for plant photosynthesis, thereby promoting plant growth; the light conversion film can effectively absorb the near-ultraviolet and blue light in the sunlight, which are more abundant, and convert them into red light required for plant growth and less abundant in the sunlight, thus optimizing the light quality ratio in the field.

[0018] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0019] Figure 1This is a flowchart of the preparation method of the red phosphor that is efficiently excited by near-ultraviolet and blue light in this invention; Figure 2 The X-ray diffraction patterns of the red phosphors prepared in Examples 1-5 and Comparative Example 1 of this invention are shown below. Figure 3 This is a scanning electron microscope image of the red phosphor prepared in Example 1 of the present invention after ball milling; Figure 4 The excitation spectra of the red phosphors prepared in Examples 1-5 and Comparative Example 1 of this invention are compared. Figure 5 The emission spectra of the red phosphors prepared in Examples 1-5 and Comparative Example 1 of this invention are compared. Figure 6 The fluorescence quantum efficiency diagrams of the red phosphors prepared in Example 1 and Comparative Example 1 of the present invention under excitation at wavelengths of 370 nm and 460 nm are shown. Figure 6 (a) in the figure is the fluorescence quantum efficiency diagram of the red phosphor prepared in Example 1 under excitation at a wavelength of 370 nm; Figure 6 (b) in the figure is the fluorescence quantum efficiency diagram of the red phosphor prepared in Example 1 under excitation at a wavelength of 460 nm; Figure 6 (c) in the figure is the fluorescence quantum efficiency diagram of the red phosphor prepared in Comparative Example 1 under excitation at a wavelength of 370 nm; Figure 6 (d) in the figure is the fluorescence quantum efficiency diagram of the red phosphor prepared in Comparative Example 1 under excitation at a wavelength of 460 nm; Figure 7 This is a graph showing the water-thermal stability test results of the red phosphor prepared in Example 1 of the present invention; Figure 8 The graph shows the integral intensity curves of the luminescence thermal stability of the red phosphors prepared in Example 1 and Comparative Example 1 of this invention. Figure 9 This is a comparison diagram of the electroluminescence spectrum and the plant pigment absorption spectrum of the pc-LED device prepared based on the red phosphor in Example 1 of the present invention; Figure 10 This is a comparison diagram of the light conversion film prepared based on the red phosphor in Example 1 of the present invention and the solar spectrum. Detailed Implementation

[0020] The technical method of the present invention will be further described below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specifically stated, the relative arrangement of steps, numerical expressions, and values ​​in these embodiments do not limit the scope of this application.

[0021] The following description of at least one exemplary embodiment is merely illustrative and is not intended to limit the scope of this application or its application or use.

[0022] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0023] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0024] The chemical formula of the red phosphor that is efficiently excited by near-ultraviolet and blue light provided by this invention is: Ca 14-x K x Ga 9.8-x Ti x Zn6O 35 0.2Mn 4+ ; Where 0 < x ≤ 1, and 0.2 is Mn 4+ The molar amount of doping.

[0025] The technical principles involved in the near-ultraviolet and blue light highly efficient excitation red phosphor provided by this invention are as follows: 1. Through Ti 4+ Replace Ga 3+ The resulting lattice contraction effect, and K + For Ca 2+ The non-equivalent substitution generates a suitable amount of oxygen vacancies, which together induce overall lattice contraction, effectively shortening the Mn crystal. 4+ Ion spacing, enhancing Mn 4+ The inter-electron cloud expansion effect reduces the Racah parameter B, leading to 4 The T1 energy level decreases, inducing... 4 A2→ 4 T1 UV excitation peak redshift.

[0026] Simultaneously enhances Mn 4+ Inter-cross relaxation effect, activating Mn 4+ ( 4 T1)+Mn 4+ ( 4 A2)→Mn 4+ ( 4 T2)+Mn 4+ ( 4 T2) Energy relaxation channels significantly enhance 4 A2→ 4 T2 blue light excitation intensity.

[0027] 2. K-Ti co-doping shortens the Mn-O bond length and strengthens the Mn-O bond, thereby improving the rigidity of the crystal structure. At the same time, it increases the electronic thermal quenching barrier, suppresses high-temperature non-radiative transitions, and improves the high-temperature luminescence stability of the phosphor.

[0028] This invention provides a method for preparing a red phosphor that can be efficiently excited by near-ultraviolet and blue light, such as... Figure 1 As shown, it includes the following steps: S1. Weigh out the calcium source, potassium source, gallium source, titanium source, zinc source, and manganese source according to the stoichiometric ratio. Each of the calcium source, potassium source, gallium source, titanium source, zinc source, and manganese source is independently selected from oxides or carbonates.

[0029] S2. Place the weighed calcium source, potassium source, gallium source, titanium source, zinc source and manganese source in a mortar, add the dispersion medium, and grind until they are evenly mixed to obtain a mixture.

[0030] S3. Place the mixture in a crucible and sinter it in air at a constant temperature of 1100℃~1400℃ for 2h~6h to obtain the sintered product.

[0031] S4. Cool the sintered product to room temperature, grind and pulverize it to obtain red phosphor.

[0032] Specifically, the embodiments provided by the present invention are as follows: Example 1 A red phosphor that is efficiently excited by near-ultraviolet and blue light, with the chemical formula Ca 13.8 K 0.2 Ga 9.6 Ti 0.2 Zn6O 35 0.2Mn 4+ The preparation method includes the following steps: S1, according to the chemical formula Ca 13.8 K 0.2 Ga 9.6 Ti 0.2 Zn6O 35 0.2Mn 4+ The stoichiometric ratios of Ca, K, Ga, Ti, Zn, and Mn were determined by weighing 0.6298g CaCO3 (analytical grade), 0.0063g K2CO3 (analytical grade), 0.4081g Ga2O3 (analytical grade), 0.0073g TiO2 (analytical grade), 0.2227g ZnO (analytical grade), and 0.0079g MnO2 (analytical grade) as raw materials.

[0033] S2. Place all raw materials in an agate mortar, add anhydrous ethanol to completely soak the raw materials, and then grind thoroughly for 25 minutes until the raw materials are completely mixed and homogeneous to obtain a mixture.

[0034] S3. The mixture is loaded into an alumina crucible and placed in a box furnace. The temperature is increased to 1250℃ at a rate of 5℃ / min under air atmosphere, and sintered at this temperature for 4 hours. After sintering, the mixture is allowed to cool naturally to room temperature in the furnace. The sintered product is then removed and thoroughly ground to obtain the red phosphor Ca. 13.8 K 0.2 Ga 9.6 Ti 0.2 Zn6O 35 0.2Mn 4+ .

[0035] Example 2 A red phosphor that is efficiently excited by near-ultraviolet and blue light, with the chemical formula Ca 13.6 K 0.4 Ga 9.4 Ti 0.4 Zn6O 35 0.2Mn 4+ The preparation method includes the following steps: S1, according to the chemical formula Ca 13.6 K 0.4 Ga 9.4 Ti 0.4 Zn6O 35 0.2Mn 4+ Based on the stoichiometric ratio of Ca, K, Ga, Ti, Zn, and Mn, 0.6207g CaCO3 (analytical grade), 0.0126g K2CO3 (analytical grade), 0.3996g Ga2O3 (analytical grade), 0.0146g TiO2 (analytical grade), 0.2227g ZnO (analytical grade), and 0.0079g MnO2 (analytical grade) were weighed as raw materials.

[0036] S2. Place all raw materials in an agate mortar, add anhydrous ethanol to completely soak the raw materials, and then grind thoroughly for 25 minutes until the raw materials are completely mixed and homogeneous to obtain a mixture.

[0037] S3. The mixture is loaded into an alumina crucible and placed in a box furnace. The temperature is increased to 1250℃ at a rate of 5℃ / min under air atmosphere, and sintered at this temperature for 4 hours. After sintering, the mixture is allowed to cool naturally to room temperature in the furnace. The sintered product is then removed and thoroughly ground to obtain the red phosphor Ca. 13.6 K 0.4 Ga 9.4 Ti 0.4 Zn6O 35 0.2Mn 4+ .

[0038] Example 3 A red phosphor that is efficiently excited by near-ultraviolet and blue light, with the chemical formula Ca 13.4 K0.6 Ga 9.2 Ti 0.6 Zn6O 35 0.2Mn 4+ The preparation method includes the following steps: S1, according to the chemical formula Ca 13.4 K 0.6 Ga 9.2 Ti 0.6 Zn6O 35 0.2Mn 4+ The stoichiometric ratios of Ca, K, Ga, Ti, Zn, and Mn were determined by weighing 0.6116g CaCO3 (analytical grade), 0.0189g K2CO3 (analytical grade), 0.3911g Ga2O3 (analytical grade), 0.0219g TiO2 (analytical grade), 0.2227g ZnO (analytical grade), and 0.0079g MnO2 (analytical grade) as raw materials.

[0039] S2. Place all raw materials in an agate mortar, add anhydrous ethanol to completely soak the raw materials, and then grind thoroughly for 25 minutes until the raw materials are completely mixed and homogeneous to obtain a mixture.

[0040] S3. The mixture is loaded into an alumina crucible and placed in a box furnace. The temperature is increased to 1250℃ at a rate of 5℃ / min under air atmosphere, and sintered at this temperature for 4 hours. After sintering, the mixture is allowed to cool naturally to room temperature in the furnace. The sintered product is then removed and thoroughly ground to obtain the red phosphor Ca. 13.4 K 0.6 Ga 9.2 Ti 0.6 Zn6O 35 0.2Mn 4+ .

[0041] Example 4 A red phosphor that is efficiently excited by near-ultraviolet and blue light, with the chemical formula Ca 13.2 K 0.8 Ga9Ti 0.8 Zn6O 35 0.2Mn 4+ The preparation method includes the following steps: S1, according to the chemical formula Ca 13.2 K 0.8 Ga9Ti 0.8 Zn6O 35 0.2Mn 4+The stoichiometric ratios of Ca, K, Ga, Ti, Zn, and Mn were determined by weighing 0.6025g CaCO3 (analytical grade), 0.0252g K2CO3 (analytical grade), 0.3826g Ga2O3 (analytical grade), 0.0291g TiO2 (analytical grade), 0.2227g ZnO (analytical grade), and 0.0079g MnO2 (analytical grade) as raw materials.

[0042] S2. Place all raw materials in an agate mortar, add anhydrous ethanol to completely soak the raw materials, and then grind thoroughly for 25 minutes until the raw materials are completely mixed and homogeneous to obtain a mixture.

[0043] S3. The mixture is loaded into an alumina crucible and placed in a box furnace. The temperature is increased to 1250℃ at a rate of 5℃ / min under air atmosphere, and sintered at this temperature for 4 hours. After sintering, the mixture is allowed to cool naturally to room temperature in the furnace. The sintered product is then removed and thoroughly ground to obtain the red phosphor Ca. 13.2 K 0.8 Ga9Ti 0.8 Zn6O 35 0.2Mn 4+ .

[0044] Example 5 A red phosphor that is efficiently excited by near-ultraviolet and blue light, with the chemical formula Ca 13 KGa 8.8 TiZn6O 35 0.2Mn 4+ The preparation method includes the following steps: S1, according to the chemical formula Ca 13 KGa 8.8 TiZn6O 35 0.2Mn 4+ The stoichiometric ratios of Ca, K, Ga, Ti, Zn, and Mn were determined by weighing 0.5933g CaCO3 (analytical grade), 0.0315g K2CO3 (analytical grade), 0.3741g Ga2O3 (analytical grade), 0.0364g TiO2 (analytical grade), 0.2227g ZnO (analytical grade), and 0.0079g MnO2 (analytical grade) as raw materials.

[0045] S2. Place all raw materials in an agate mortar, add anhydrous ethanol to completely soak the raw materials, and then grind thoroughly for 25 minutes until the raw materials are completely mixed and homogeneous to obtain a mixture.

[0046] S3. The mixture is loaded into an alumina crucible and placed in a box furnace. The temperature is increased to 1250℃ at a rate of 5℃ / min under air atmosphere, and sintered at this temperature for 4 hours. After sintering, the mixture is allowed to cool naturally to room temperature in the furnace. The sintered product is then removed and thoroughly ground to obtain the red phosphor Ca. 13 KGa 8.8 TiZn6O 35 0.2Mn 4+ .

[0047] Comparative Example 1 A red phosphor with the chemical formula Ca 14 Ga 9.8 Zn6O 35 0.2Mn 4+ The preparation method includes the following steps: S1, according to the chemical formula Ca 14 Ga 9.8 Zn6O 35 0.2Mn 4+ The stoichiometric ratio of Ca, Ga, Zn and Mn elements was determined by weighing 0.6390g CaCO3 (analytical grade), 0.4166g Ga2O3 (analytical grade), 0.2227g ZnO (analytical grade) and 0.0079g MnO2 (analytical grade) as raw materials.

[0048] S2. Place all raw materials in an agate mortar, add anhydrous ethanol to completely soak the raw materials, and then grind thoroughly for 25 minutes until the raw materials are completely mixed and homogeneous to obtain a mixture.

[0049] S3. The mixture is loaded into an alumina crucible and placed in a box furnace. The temperature is increased to 1250℃ at a rate of 5℃ / min under air atmosphere, and sintered at this temperature for 4 hours. After sintering, the mixture is allowed to cool naturally to room temperature in the furnace. The sintered product is then removed and thoroughly ground to obtain the red phosphor Ca. 14 Ga 9.8 Zn6O 35 0.2Mn 4+ .

[0050] Performance testing X-ray diffraction (XRD) analysis Figure 2 The XRD diffraction patterns are shown for the red phosphors prepared in Examples 1-5 and Comparative Example 1. Figure 2 It can be seen that the diffraction peaks of the red phosphors prepared in Examples 1-5 and Comparative Example 1 correspond one-to-one with the peak positions of the standard card (PDF#97-024-5649), and no other impurity peaks were observed, indicating that each red phosphor sample is a single phase. + -Ti 4+Co-substitution without the introduction of heterogeneous phases.

[0051] Scanning electron microscopy analysis Figure 3 Scanning electron microscope (SEM) image of the red phosphor prepared in Example 1. According to... Figure 3 It can be seen that the red phosphor Ca 13.8 K 0.2 Ga 9.6 Ti 0.2 Zn6O 35 0.2Mn 4+ It has an irregular morphology and good dispersion, which is beneficial for the packaging of light-emitting diode (LED) devices and the preparation of light conversion films.

[0052] Excitation spectral analysis Figure 4 The excitation spectra of the red phosphors prepared in Examples 1-5 and Comparative Example 1 are shown. When testing the excitation spectra, the emission monitoring wavelength λ is... em Fixed at 713nm. According to Figure 4 It can be seen that as the K-Ti content increases, the red phosphors in Comparative Example 1 and Examples 1-5 correspond to... 4 A2→ 4 The ultraviolet excitation peak of the T1 transition undergoes a redshift, while the corresponding 4 A2→ 4 The peak position of the blue light excitation peak during the T2 transition remains unchanged. Furthermore, the corresponding... 4 A2→ 4 The UV excitation peak of the T1 transition first increases and then rapidly decreases with increasing K-Ti content, while 4 A2→ 4 The intensity of the blue light excitation peak of the T2 transition initially increases and then slowly decreases. (Comparative Example 1: Red phosphor Ca...) 14 Ga 9.8 Zn6O 35 0.2Mn 4+ The ultraviolet excitation intensity is significantly higher than the blue light excitation intensity. In Example 5, the red phosphor Ca... 13 KGa 8.8 TiZn6O 35 0.2Mn 4+ The ultraviolet excitation intensity is basically the same as the blue light excitation intensity. The red phosphor Ca in Example 1... 13.8 K 0.2 Ga 9.6 Ti 0.2 Zn6O 35 0.2Mn 4+ The intensity of both ultraviolet excitation and blue light excitation was the highest.

[0053] Emission spectroscopy analysis Emission spectroscopy test: at their respective optimal excitation wavelengths λ ex (Comparative Example 1 uses 335 nm, Examples 1-5 use 343 nm, 345 nm, 347 nm, 348 nm, and 349 nm respectively) Under excitation, the emission spectra of each red phosphor were measured, and the results are as follows: Figure 5 As shown. According to Figure 5 It can be seen that, under the optimal excitation wavelength, the emission spectra of the red phosphors prepared in Examples 1-5 cover the wavelength range of 650 nm to 800 nm. The emission intensity of the red phosphors prepared in Examples 1-5 and Comparative Example 1 first increases and then decreases, consistent with the trend of excitation intensity change, with the highest peak value of the emission spectrum all at 713 nm. Comparison shows that the red phosphor Ca in Example 1... 13.8 K 0.2 Ga 9.6 Ti 0.2 Zn6O 35 0.2Mn 4+ It has the strongest launch intensity.

[0054] Quantum efficiency test Figure 6 The graph shows the quantum efficiency test results of the red phosphors prepared in Example 1 and Comparative Example 1.

[0055] according to Figure 6 (a) Figure 6 (b) Figure 6 (c) and Figure 6 As can be seen from (d) in Example 1, under excitation at 370 nm and 460 nm, the red phosphor Ca in Example 1... 13.8 K 0.2 Ga 9.6 Ti 0.2 Zn6O 35 0.2Mn 4+ The external quantum efficiency (EQE) of the two phosphors were 54.6% and 43.9%, respectively. (Comparative Example 1: Red phosphor Ca...) 14 Ga 9.8 Zn6O 35 0.2Mn 4+ Their EQEs were 35.8% and 25.0%, respectively.

[0056] The red phosphor Ca in Example 1 13.8 K 0.2 Ga 9.6 Ti 0.2 Zn6O 35 0.2Mn4+ Even under blue light excitation, it still retains over 40% EQE, which is significant in Mn. 4+ Activated oxide-based phosphor materials are relatively rare and can be efficiently excited by blue light chips, enhancing their application capabilities in phosphor-converted light-emitting diodes (pc-LEDs). Meanwhile, due to the red phosphor Ca in Example 1... 13.8 K 0.2 Ga 9.6 Ti 0.2 Zn6O 35 0.2Mn 4+ It has almost the same strong absorption capacity in the near-ultraviolet and blue light regions, so it also has broad application prospects in the field of light conversion materials for plant growth.

[0057] Water-thermal stability test Figure 7 The image shows the water-thermal stability test results of the red phosphor prepared in Example 1. The specific conditions for the water-thermal stability test were as follows: the red phosphor prepared in Example 1 was subjected to water-thermal stability testing... 13.8 K 0.2 Ga 9.6 Ti 0.2 Zn6O 35 0.2Mn 4+ Place in an environment of 85℃-85% relative humidity (RH) for 1000 hours. According to... Figure 7 It can be seen that after 1000 hours, the red phosphor Ca prepared in Example 1... 13.8 K 0.2 Ga 9.6 Ti 0.2 Zn6O 35 0.2Mn 4+ The luminescence intensity can still maintain 99.8% of the initial intensity, indicating that it has excellent water-thermal stability.

[0058] Thermal stability test Figure 8 The graph shows the integral intensity curves of the luminescence thermal stability of the red phosphors prepared in Example 1 and Comparative Example 1. Figure 8 It can be seen that the red phosphor Ca prepared in Example 1 13.8 K 0.2 Ga 9.6 Ti 0.2 Zn6O 35 0.2Mn 4+ At 150℃, it can maintain 88.12% of the luminescence intensity at room temperature. (Comparative Example 1: Red phosphor Ca...) 14 Ga 9.8 Zn6O35 0.2Mn 4+ It can only maintain 83.96% of the temperature at room temperature, indicating that after K + -Ti 4+ After co-substitution, the thermal stability of the phosphor is significantly improved.

[0059] Application testing The red phosphor Ca from Example 1 13.8 K 0.2 Ga 9.6 Ti 0.2 Zn6O 35 0.2Mn 4+ Mix the ergo 8500 UV-curable adhesive evenly at a mass ratio of 3:1, inject it into the LED cavity containing the 460nm blue light chip until it is almost overflowing, and then complete the curing under UV light to complete the encapsulation of the plant LED light, thus obtaining the pc-LED.

[0060] Take the red phosphor Ca from Example 1 13.8 K 0.2 Ga 9.6 Ti 0.2 Zn6O 35 0.2Mn 4+ Mix 15g of polypropylene (PP) granules with 230g of polypropylene (PP) granules, put them into an internal mixer at 200℃ and 30rpm for melt blending. After the mixture is uniform, put the mixture into a 41cm×41cm template and press it into a film in a 190℃ tablet press. After cooling, take it out to obtain the light-converting film.

[0061] Figure 9 The electroluminescence spectrum of the pc-LED device prepared based on the red phosphor in Example 1 is compared with that of plant chlorophyll a, b, and photopigment (P). R and P FR A comparison chart of absorption spectra. Based on... Figure 9 It can be seen that the peak at 460nm in the electroluminescence spectrum originates from the blue light chip, while the peak at 650nm-800nm ​​originates from the red phosphor. The blue and deep red light emitted by this PC-LED device can cover the absorption spectrum of chlorophyll and phytochrome, indicating that it can effectively supplement the red and blue light components required for plant photosynthesis, thereby promoting plant growth.

[0062] Figure 10 This is a comparison diagram of the excitation and emission spectra of the light-converting film prepared based on the red phosphor in Example 1 with the solar spectrum. According to... Figure 10It is known that this light-converting film can effectively absorb the near-ultraviolet and blue light, which are abundant in sunlight, and convert them into red light, which is needed for plant growth and is present in less abundant sunlight. Therefore, the red phosphor Ca in Example 1... 13.8 K 0.2 Ga 9.6 Ti 0.2 Zn6O 35 0.2Mn 4+ It is very suitable as a light-converting material for light-converting films.

[0063] In summary, the high-efficiency near-ultraviolet and blue-light-excited red phosphor provided by this invention can be used as a luminescent material for plant growth. This invention utilizes K... + -Ti 4+ Ion-pair co-substituted Ca 14 Ga 9.8 Zn6O 35 0.2Mn 4+ Ca in the matrix 2+ -Ga 3+ By utilizing lattice contraction and cross-relaxation enhancement mechanisms, the excitation efficiency of phosphors in the near-ultraviolet and blue light bands is simultaneously improved, effectively solving the problem of traditional Mn... 4+ This invention addresses the technical bottleneck of low excitation efficiency of activated phosphors in the near-ultraviolet and blue light regions. The newly developed red phosphor emits deep red light in the 650-800nm ​​range, which highly matches the absorption spectra of plant chlorophyll and phytochromes. Under excitation at 370nm and 460nm, its external quantum efficiency reaches 54.6% and 43.9%, respectively. At 150℃, its luminescence intensity retains 88.12% of its room temperature value, and after 1000 hours at 85℃-85% relative humidity, its luminescence intensity retains 99.8% of its initial value, demonstrating excellent overall performance. Furthermore, this invention employs a high-temperature solid-state air sintering method, utilizing inexpensive and readily available raw materials, employing a simple process suitable for mass production. Moreover, the PC-LED devices encapsulated with this red phosphor and the prepared light-converting film both exhibit excellent plant lighting and supplemental lighting effects, possessing significant application value and broad industrialization prospects in the fields of supplemental lighting and plant illumination devices for facility agriculture.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A red phosphor that is efficiently excited by near-ultraviolet and blue light, characterized in that, The chemical formula of the red phosphor that is efficiently excited by near-ultraviolet and blue light is: Ca 14-x K x Him 9.8-x You x Zn6O 35 :0.2Mn 4+ ; Where 0 < x ≤ 1, and 0.2 is Mn 4+ The molar amount of doping.

2. The red phosphor that is efficiently excited by near-ultraviolet and blue light according to claim 1, characterized in that, The value of x is in the range of 0.2 ≤ x ≤ 1.

3. The red phosphor that is efficiently excited by near-ultraviolet and blue light according to claim 2, characterized in that, The value of x is 0.

2.

4. The red phosphor that is efficiently excited by near-ultraviolet and blue light according to claim 1, characterized in that, The emission spectrum of the red phosphor, which is efficiently excited by near-ultraviolet and blue light, covers the wavelength range of 650 nm to 800 nm.

5. The red phosphor that is efficiently excited by near-ultraviolet and blue light according to claim 3, characterized in that, The external quantum efficiency of the red phosphor, which is highly excited by near-ultraviolet and blue light, is ≥54% under near-ultraviolet light excitation at 370nm and ≥43% under blue light excitation at 460nm, as determined by the integrating sphere method at room temperature.

6. The red phosphor that is efficiently excited by near-ultraviolet and blue light according to claim 3, characterized in that, The red phosphor, which is efficiently excited by near-ultraviolet and blue light, maintains more than 88% of its room temperature luminescence intensity at 150°C.

7. A method for preparing red phosphors that are efficiently excited by near-ultraviolet and blue light, characterized in that, The method for preparing the near-ultraviolet and blue light-efficiently excitable red phosphor as described in any one of claims 1 to 6 comprises the following steps: S1. Weigh out the calcium source, potassium source, gallium source, titanium source, zinc source, and manganese source according to the stoichiometric ratio; each of the calcium source, potassium source, gallium source, titanium source, zinc source, and manganese source is independently selected from oxides or carbonates; S2. Place the weighed calcium source, potassium source, gallium source, titanium source, zinc source and manganese source in a mortar, add the dispersion medium, and grind until they are evenly mixed to obtain a mixture. S3. Place the mixture in a crucible and sinter it in air at a constant temperature of 1100℃~1400℃ for 2h~6h to obtain the sintered product. S4. Cool the sintered product to room temperature, grind and pulverize it to obtain red phosphor.

8. The method for preparing red phosphor efficiently excited by near-ultraviolet and blue light according to claim 7, characterized in that, The dispersion medium is anhydrous ethanol; the amount of anhydrous ethanol added is based on the amount of calcium, potassium, gallium, titanium, zinc and manganese sources after complete impregnation and weighing.

9. The method for preparing red phosphor efficiently excited by near-ultraviolet and blue light according to claim 7, characterized in that, In S3, the temperature is increased to the sintering temperature at a heating rate of 2℃ / min to 5℃ / min.

10. The application of red phosphors that are efficiently excited by near-ultraviolet and blue light, characterized in that, The red phosphor that is efficiently excited by near-ultraviolet and blue light according to any one of claims 1 to 6 is used to prepare a plant lighting device for plant growth; the plant lighting device includes: a pc-LED lighting device and a light conversion film; The pc-LED lighting device is encapsulated from phosphor and blue light chip; The light-converting film is prepared by combining phosphor with a polymer resin substrate; the polymer resin is one of polypropylene, epoxy resin and polydimethylsiloxane.

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