Novel high-thermal-stability plant illumination luminescent material

Abstract

The invention relates to a novel luminescent material with high thermal stability for plant illumination, the chemical general formula of the luminescent material is CaLuGaO4: 0.01 Bi < 3 + >, yEu < 3 + >, and y = 0.01-0.15; the material generates blue-red dual emission under 365 nm effective excitation, the blue-red dual emission is 400-550 nm blue-light broadband emission and 600-700 nm red-light narrow-band emission respectively, the material also has high thermal stability, the emission intensity of the material at the working temperature of 423 K can keep 81.7% of the initial value at the room temperature of 298 K, the blue-red dual emission of the CaLuGaO4: 0.01 Bi < 3 + >, yEu < 3 + > (y = 0.01-0.15) luminescent material is high in absorption spectrum matching degree with chlorophyll a and chlorophyll b, and the luminescent material can be widely applied to the field of luminescent materials. The device can be applied to plant illumination.

Description

Technical Field

[0001] The invention relates to the technical field of inorganic luminescent materials, in particular to a luminescent material for plant lighting with high thermal stability. Background Art

[0002] With the continuous development of science and technology, there is an increasing demand for high-performance luminescent materials. Because phosphors have the characteristics of easy spectrum change, long life, and high energy efficiency, they have important application significance in daily lighting and agricultural supplementary lighting. During the growth process, plants carry out photosynthesis through pigments. Plant pigments are mainly composed of chlorophyll a, chlorophyll b, phytochrome PR and phytochrome PFR. The absorption of these plant pigments is located in three spectral regions: the light absorption of chlorophyll a and b is located near 400-500nm blue-cyan, and the phytochrome PR has significant absorption of 600-700nm red light, which promotes the growth and phototropism of plant stems. Phytochrome PFR is particularly sensitive to far-red light (700-750nm), which controls the germination and flowering time of plants. Therefore, it is very important to have fluorescent materials suitable for ultraviolet light excitation and emit blue and red.

[0003] Energy transfer (ET) from sensitizer to activated ions is considered to be the most effective method to achieve blue-red dual emission. 3+ The excitation wavelength of the ion is in the ultraviolet and near-ultraviolet region, which can avoid visible light reabsorption and is an excellent sensitizer and activator in phosphors. 3+ Ions can emit red (or orange-red) light between 550 and 750 nm. By using a suitable matrix, Bi 3+ -Eu 3+ The emission spectrum of the co-doped luminescent material is matched with the absorption curve of the photosensitive pigment. 3+ -Eu 3+ The co-doped luminescent materials have low thermal stability and the excitation wavelength is close to the far ultraviolet region, which increases the cost of plant lighting. Summary of the invention

[0004] The technical problem to be solved by the present invention is to propose a Bi 3+ -Eu 3+ Co-doped gallate-based luminescent material and its preparation method, the luminescent material has good thermal stability, when heated to 150 degrees, its luminous intensity is 81% of that at room temperature, and can be efficiently excited by commercial 365nm LED chips, greatly reducing the cost of plant lighting. 3+ The doping concentration can adjust the color and brightness of the light emitted by the luminescent material to meet the needs of plant lighting.

[0005] The present invention adopts the following scheme to solve the above problems:

[0006] A novel high thermal stability plant lighting luminescent material, wherein the chemical formula of the high thermal stability plant lighting luminescent material is CaLuGaO4:0.01Bi 3+ ,yEu 3+ , where y = 0.01 to 0.15;

[0007] The preparation method of the novel high thermal stability plant lighting luminescent material, wherein the main phase of the novel high thermal stability plant lighting luminescent material is an olivine structure with a Pnma space group; under 365nm excitation, by changing Eu 3+ The doping concentration can change the emission color

[0008] The method for preparing the phosphor comprises the following steps:

[0009] (1) Weighing: Weigh the raw materials containing Ca, Lu, Ga, O, Bi, and Eu elements according to their chemical composition, and the stoichiometric ratio is 1:1:1:4:0.01:y, where y = 0.01 to 0.15;

[0010] (2) Grinding: Grind for 30 minutes to mix evenly and place in a reaction container;

[0011] (3) Sintering: Sintering is carried out in an air atmosphere, then cooled to room temperature and ground to obtain the target product, plant lighting luminescent material.

[0012] The above-mentioned novel method for preparing the high thermal stability plant lighting luminescent material is formed by mixing a Ca-containing compound, a Lu-containing compound, a Ga-containing compound, a Bi-containing compound and a Eu-containing compound and then sintering them.

[0013] In the method for producing the novel high thermal stability plant lighting luminescent material, the Ca-containing compound is a mixture of one or more of Ca oxides, carbonates, oxalates, acetates, nitrates, and hydroxides.

[0014] In the method for preparing the above-mentioned novel high thermal stability plant lighting luminescent material, the Lu-containing compound is a mixture of one or more of Lu oxides, carbonates, oxalates, acetates, nitrates, and hydroxides.

[0015] In the method for producing the above-mentioned novel high thermal stability plant lighting luminescent material, the Ga-containing compound is a mixture of one or more of Ga oxides, carbonates, oxalates, acetates, nitrates, and hydroxides.

[0016] In the method for preparing the above-mentioned novel high thermal stability plant lighting luminescent material, the Bi-containing compound is a mixture of one or more of Bi oxides, carbonates, oxalates, acetates, nitrates, and hydroxides.

[0017] In the method for producing the above-mentioned novel high thermal stability plant lighting luminescent material, the Eu-containing compound is a mixture of one or more of Eu's oxides, carbonates, oxalates, acetates, nitrates, and hydroxides.

[0018] The method for producing the above-mentioned new type of high thermal stability plant lighting luminescent material has a temperature of 1300 degrees and a sintering time of about 6 hours.

[0019] The advantages of this technology are:

[0020] 1. The present invention Bi 3+ ,Eu 3+ The co-doped high thermal stability plant lighting luminescent material is prepared by a high-temperature solid-phase method. The preparation process is simple, the equipment requirements are low, and the synthesis process has no specific pressure or atmosphere requirements. The preparation process is simple, the energy consumption is low, and it can be effectively excited by a commercial 365nm ultraviolet chip, thereby reducing lighting costs.

[0021] 2. The high thermal stability plant lighting luminescent material of the present invention has high phase purity, does not change in structure when placed in the air, and has good stability.

[0022] 3. Bi of the present invention 3+ and Eu 3+ Co-doped high thermal stability plant lighting luminescent material, using relatively low-priced Bi 3+ and Eu 3+ The compounds are used as the source of activators, which are environmentally friendly and reduce the cost of plant lighting lamps. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The high thermal stability plant lighting luminescent material CaLuGaO4:0.01Bi prepared in Example 1-6 3+ ,yEu 3 + , y=0.01, 0.02, 0.06, 0.08, 0.12, 0.15; and X-ray diffraction (XRD) pattern of CaLuGaO4 card;

[0024] Figure 2 The high thermal stability plant lighting luminescent material CaLuGaO4:0.01Bi prepared in Example 1-6 3+ ,yEu 3+ , emission spectra of y = 0.01, 0.02, 0.06, 0.08, 0.12, 0.15;

[0025] Figure 3 The high thermal stability plant lighting luminescent material CaLuGaO4:0.01Bi prepared in Example 1-6 3+ ,yEu 3+ , chromaticity coordinate diagram of y=0.01, 0.02, 0.06, 0.08, 0.12, 0.15;

[0026] Figure 4 The high thermal stability plant lighting luminescent material CaLuGaO4:0.01Bi prepared in Experimental Example 3 3+ , 0.06Eu 3+ Emission spectra at different temperatures;

[0027] Figure 5 The high thermal stability plant lighting luminescent material CaLuGaO4:0.01Bi prepared in Experimental Example 3 3+ , 0.06Eu 3+ Temperature dependence diagram of ;

[0028] Figure 6 The CaLuGaO4:0.01Bi prepared in Example 3 3+ , 0.06Eu 3+ Comparison of blue-red dual-emission materials and chlorophyll a, b absorption spectra;

[0029] Figure 7 The high thermal stability plant lighting luminescent material CaLuGaO4:0.01Bi prepared in Example 3 3+ , 0.06Eu 3+ The actual picture and chromaticity coordinates of the 365nm LED chip after packaging DETAILED DESCRIPTION

[0030] The following is a detailed description of an embodiment of the present invention. This embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation method and specific operation process are given, but the protection scope of the present invention is not limited to the following embodiment.

[0031] Select CaCO3, Lu2O3, Ga2O3, Bi2O3, and Eu2O3 as starting compound raw materials, and weigh the four compound raw materials according to the molar ratio of each element to prepare the corresponding materials;

[0032] Example 1

[0033] The high thermal stability plant lighting luminescent material of this embodiment 1 is composed of Bi 3+ and Eu 3+ Co-doped gallate, chemical formula: CaLuGaO4:0.01Bi 3+, 0.01Eu 3+ , the preparation method is as follows:

[0034] High-purity CaCO3 (analytical grade), Lu2O3 (purity 99.99%), Ga2O3 (purity 99.99%), Bi2O3 (purity 99.99%), and Eu2O3 (purity 99.99%) are used as starting raw materials, with a molar ratio of Ca:Lu:Ga:Bi:Eu=1:1:1:0.01:0.01; the mass of each oxide or carbonate is accurately weighed, and the weighed raw materials are mixed and ground in an agate mortar for 0.5 h to obtain a mixture; the crucible containing the mixture is placed in a high-temperature muffle furnace, sintered at 1300°C for 6 h, and after cooling to room temperature with the furnace, ground to obtain a luminescent material for plant lighting with high thermal stability.

[0035] Example 2

[0036] The high thermal stability plant lighting luminescent material of this embodiment 2 is composed of Bi 3+ and Eu 3+ Co-doped gallate, chemical formula: CaLuGaO4:0.01Bi 3+ , 0.02Eu 3+ , the preparation method is as follows:

[0037] High-purity CaCO3 (analytical grade), Lu2O3 (purity 99.99%), Ga2O3 (purity 99.99%), Bi2O3 (purity 99.99%), and Eu2O3 (purity 99.99%) are used as starting raw materials, with a molar ratio of Ca:Lu:Ga:Bi:Eu=1:1:1:0.01:0.02; the mass of each oxide or carbonate is accurately weighed, and the weighed raw materials are mixed and ground in an agate mortar for 0.5 h to obtain a mixture; the crucible containing the mixture is placed in a high-temperature muffle furnace, sintered at 1300°C for 6 h, and after cooling to room temperature with the furnace, ground to obtain a luminescent material for plant lighting with high thermal stability.

[0038] Example 3

[0039] The high thermal stability plant lighting luminescent material of this embodiment 3 is composed of Bi 3+ and Eu 3+ Co-doped gallate, chemical formula: CaLuGaO4:0.01Bi 3+ , 0.06Eu 3+ , the preparation method is as follows:

[0040] High-purity CaCO3 (analytical grade), Lu2O3 (purity 99.99%), Ga2O3 (purity 99.99%), Bi2O3 (purity 99.99%), and Eu2O3 (purity 99.99%) are used as starting raw materials, with a molar ratio of Ca:Lu:Ga:Bi:Eu=1:1:1:0.01:0.06; the mass of each oxide or carbonate is accurately weighed, and the weighed raw materials are mixed and ground in an agate mortar for 0.5 h to obtain a mixture; the crucible containing the mixture is placed in a high-temperature muffle furnace, sintered at 1300°C for 6 h, and after cooling to room temperature with the furnace, ground to obtain a luminescent material for plant lighting with high thermal stability.

[0041] Example 4

[0042] The high thermal stability plant lighting luminescent material of this embodiment 4 is composed of Bi 3+ and Eu 3+ Co-doped gallate, chemical formula: CaLuGaO4:0.01Bi 3+ , 0.08Eu 3+ The preparation method is as follows:

[0043] High-purity CaCO3 (analytical grade), Lu2O3 (purity 99.99%), Ga2O3 (purity 99.99%), Bi2O3 (purity 99.99%), and Eu2O3 (purity 99.99%) are used as starting raw materials, with a molar ratio of Ca:Lu:Ga:Bi:Eu=1:1:1:0.01:0.08; the mass of each oxide or carbonate is accurately weighed, and the weighed raw materials are mixed and ground in an agate mortar for 0.5 h to obtain a mixture; the crucible containing the mixture is placed in a high-temperature muffle furnace, sintered at 1300°C for 6 h, and after cooling to room temperature with the furnace, ground to obtain a luminescent material for plant lighting with high thermal stability.

[0044] Example 5

[0045] The high thermal stability plant lighting luminescent material of this embodiment 5 is composed of Bi 3+ and Eu 3+ Co-doped gallate, chemical formula: CaLuGaO4:0.01Bi 3+ , 0.12Eu 3+ , the preparation method is as follows:

[0046] High-purity CaCO3 (analytical grade), Lu2O3 (purity 99.99%), Ga2O3 (purity 99.99%), Bi2O3 (purity 99.99%), and Eu2O3 (purity 99.99%) are used as starting raw materials, with a molar ratio of Ca:Lu:Ga:Bi:Eu=1:1:1:0.01:0.12; the mass of each oxide or carbonate is accurately weighed, and the weighed raw materials are mixed and ground in an agate mortar for 0.5 h to obtain a mixture; the crucible containing the mixture is placed in a high-temperature muffle furnace, sintered at 1300°C for 6 h, and after cooling to room temperature with the furnace, ground to obtain a luminescent material for plant lighting with high thermal stability.

[0047] Example 6

[0048] The high thermal stability plant lighting luminescent material of this embodiment 6 is composed of Bi 3+ and Eu 3+ Co-doped gallate, chemical formula: CaLuGaO4:0.01Bi 3+ , 0.15Eu 3+ , the preparation method is as follows:

[0049] High-purity CaCO3 (analytical grade), Lu2O3 (purity 99.99%), Ga2O3 (purity 99.99%), Bi2O3 (purity 99.99%), and Eu2O3 (purity 99.99%) are used as starting raw materials, with a molar ratio of Ca:Lu:Ga:Bi:Eu=1:1:1:0.01:0.15; the mass of each oxide or carbonate is accurately weighed, and the weighed raw materials are mixed and ground in an agate mortar for 0.5 h to obtain a mixture; the crucible containing the mixture is placed in a high-temperature muffle furnace, sintered at 1300°C for 6 h, and after cooling to room temperature with the furnace, ground to obtain a luminescent material for plant lighting with high thermal stability.

[0050] like Figure 1 The high thermal stability plant lighting luminescent material CaLuGaO4:0.01Bi prepared in Example 1-6 is shown. 3 + ,yEu 3+ , X-ray diffraction (XRD) patterns of y=0.01, 0.02, 0.06, 0.08, 0.12, and 0.15. In Experimental Examples 1-6, changes in the y value do not affect the synthesis of the luminescent material for plant lighting, indicating that the prepared phosphor is pure and meets the requirements.

[0051] like Figure 2 The high thermal stability plant lighting luminescent material CaLuGaO4:0.01Bi prepared in Example 1-6 is shown. 3 + ,yEu 3+, the emission spectra of y=0.01, 0.02, 0.06, 0.08, 0.12, and 0.15. As the value of y increases, the blue emission intensity decreases, and the red emission intensity first increases and then decreases, reaching the maximum value when y=0.12.

[0052] like Figure 3 The high thermal stability plant lighting luminescent material CaLuGaO4:0.01Bi prepared in Example 1-6 is shown. 3 + ,yEu 3+ , chromaticity coordinate diagram of y=0.01, 0.02, 0.06, 0.08, 0.12, and 0.15. As y increases, the emission color changes from blue to pink and finally to red.

[0053] like Figure 4 The high thermal stability plant lighting luminescent material CaLuGaO4:0.01Bi prepared in Example 3 is shown. 3+ , 0.06Eu 3+ Emission spectra at different temperatures. As the temperature increases, the luminescence intensity decreases slowly.

[0054] like Figure 5 The picture shows the high thermal stability plant lighting luminescent material CaLuGaO4:0.01Bi 3+ , 0.06Eu 3+ The temperature dependence diagram shows that the emission intensity at 423K remains at 81.7% of the initial value at room temperature 298K, which has high thermal stability.

[0055] like Figure 6 The CaLuGaO4:0.01Bi prepared in Example 3 is shown. 3+ , 0.06Eu 3+ Comparison chart of blue-red dual-emission material and chlorophyll a and b absorption spectra. The emission spectrum and the absorption spectrum of chlorophyll a and b are highly overlapped, which can be used in plant lighting to promote plant growth.

[0056] like Figure 7 The high thermal stability plant lighting luminescent material CaLuGaO4:0.01Bi prepared in Example 3 is shown. 3+ , 0.06Eu 3+ The chromaticity coordinates of the LED lamp after packaging with the 365nm LED chip are (0.4075, 0.271).

Claims

1. A new type of high thermal stability plant lighting luminescent material, characterized in that: The chemical composition of the phosphor is CaLuGaO4:0.01Bi 3+ ,yEu 3+ , wherein y=0.01-0.15; the phosphor can be effectively excited by a 365nm ultraviolet chip to produce blue and red dual emission.

2. The novel luminescent material for plant lighting with high thermal stability according to claim 1, characterized in that: The preparation method of the fluorescent powder comprises the following steps: (1) Weighing: Weigh the raw materials containing Ca, Lu, Ga, O, Bi, and Eu elements according to their chemical composition, and the stoichiometric ratio is 1:1:1:0.01:y, where y = 0.01 to 0.15; (2) Grinding: Grind for 30 minutes to mix evenly and place in a reaction container; (3) Sintering: Sintering is carried out in an air atmosphere, then cooled to room temperature, and ground to obtain the target product, which is a blue-red dual-emitting luminescent material.

3. According to claim 2, a novel high thermal stability plant lighting luminescent material is characterized in that: The plant lighting luminescent material is formed by mixing and sintering a compound containing Ca, a Lu compound, a Ga compound, a Bi compound and a compound containing Eu; The Ca-containing compound is a mixture of one or more of Ca oxides, carbonates, oxalates, acetates, nitrates and hydroxides. The Lu-containing compound is a mixture of one or more of Lu oxides, carbonates, oxalates, acetates, nitrates and hydroxides. The Ga-containing compound is a mixture of one or more of Ga oxides, carbonates, oxalates, acetates, nitrates and hydroxides. The Bi-containing compound is a mixture of one or more of Bi oxides, carbonates, oxalates, acetates, nitrates and hydroxides. The Eu-containing compound is a mixture of one or more of Eu oxides, carbonates, oxalates, acetates, nitrates and hydroxides.

4. According to claim 2, a novel luminescent material for plant lighting with high thermal stability, characterized in that: During the sintering process, the temperature is 1300 degrees, and then the temperature is kept constant for 6 hours.

5. According to claim 2, a novel luminescent material for plant lighting with high thermal stability, characterized in that: The luminescent material can be effectively excited by a 365nm LED chip to produce blue and red dual emission.

6. The novel luminescent material with high thermal stability for plant lighting according to claims 1-5 has great application prospects in the agricultural field.

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