Dysprosium-activated garnet-based white light fluorescent powder and preparation method thereof

Abstract

This invention relates to the field of luminescent materials and discloses a dysprosium-activated garnet-based white phosphor, comprising Na, Dy, RE, Ga, In, and Ge, wherein the molar ratio of the metal elements is Na:Dy:RE:Ga:In:Ge = 1:2x:2 - 2x:2:1:2, where 0.01 ≤ x < 0.10, and x is the doping amount of dysprosium at the inert rare earth sites. The invention also discloses the dysprosium-activated garnet-based white phosphor and its preparation method, including: a. reduced solid-state synthesis reaction temperature: novel matrix... a. The solid-state synthesis reaction temperature is significantly reduced to the range of 1200-1250℃, and phase formation is achieved in just 3 hours with excellent crystallinity, thus reducing energy consumption and preparation costs; b. No co-solvent required: The preparation process of phosphors does not require the use of co-solvents, reducing environmental impact; c. One-step sintering synthesis: The preparation process is simplified to one-step sintering, improving preparation efficiency and the feasibility of the production process; d. No specific pressure and atmosphere requirements: The preparation process does not require specific pressure and atmosphere requirements, reducing the limitations and complexity of process conditions.

Description

Technical Field

[0001] This invention relates to the field of luminescent materials, specifically to a dysprosium-activated garnet-based white phosphor and its preparation method. Background Technology

[0002] Today, warm white WLED devices have wide applications in the lighting field. As a highly efficient, environmentally friendly, and energy-saving lighting technology, warm white WLED devices are widely used in home lighting, commercial lighting, and automotive lighting. However, existing warm white WLED devices still face certain challenges in terms of optical performance and luminous stability, such as low luminous efficiency and uneven color temperature. Therefore, finding a new phosphor material that can provide efficient and uniform warm white light emission is of great significance for improving the performance of warm white WLED devices.

[0003] Sodium yttrium / sodium gadolinium gallium indium germanium garnet (NaRE2Ga2InGe2O) 12 (RE = Y, Gd) is a novel matrix material that exhibits excellent optical properties and chemical stability. This is achieved by doping with rare earth ions Dy... 3+ Highly efficient warm white light emission can be achieved by incorporating sodium yttrium / sodium gadolinium gallium indium germanium garnet matrix. 3+ Doped sodium yttrium / sodium gadolinium gallium indium germanium garnet matrix dysprosium activated garnet-based white phosphors have excellent luminous efficiency and luminous stability, and therefore have great application potential in warm white WLED devices.

[0004] However, currently, there is a lack of information regarding Dy for use in warm white WLED devices. 3+ Research on doped sodium yttrium / sodium gadolinium gallium indium germanium garnet matrix dysprosium-activated garnet-based white phosphors is still relatively limited. Therefore, developing a high-performance and efficient Dysprosium-activated white phosphor is crucial. 3+ The development of doped sodium yttrium / sodium gadolinium gallium indium germanium garnet matrix dysprosium activated garnet-based white phosphors and their preparation methods are of great significance for promoting the development of warm white light WLED device technology.

[0005] Based on the aforementioned technical background, this patent aims to address the shortcomings of existing phosphors used in warm white WLED devices and provides a method for preparing such phosphors. By providing a phosphor with high luminous efficiency and uniform warm white light emission characteristics... 3+ The discovery of doped sodium yttrium / sodium gadolinium gallium indium germanium garnet matrix dysprosium activated garnet-based white phosphors and their preparation methods is expected to promote the further development and application of warm white WLED devices. Summary of the Invention

[0006] (a) Technical problems to be solved

[0007] To address the shortcomings of existing technologies, this invention provides a dysprosium-activated garnet-based white phosphor and its preparation method. This phosphor can be excited by 300-320 nm ultraviolet light and 360-410 nm near-ultraviolet light, emitting a yellow light with a strongest main peak at 583 nm, accompanied by multi-peak narrow-band luminescence of blue-green and red light at 460-500 nm and 660-680 nm. Furthermore, this phosphor can be sintered in one step at temperatures as low as 1200℃, requiring only 3 hours to form the phase. The short synthesis time and low energy consumption solve the problems of insufficient spectral coverage, high synthesis temperature, and high energy consumption in stable single-matrix dysprosium-activated garnet-based white phosphors.

[0008] This phosphor has high luminous efficiency and stability, and can meet the requirements of WLED devices and other fields for dysprosium-activated garnet-based white phosphors.

[0009] (II) Technical Solution

[0010] To achieve the above-mentioned objectives, the present invention provides the following technical solution: a dysprosium-activated garnet-based white light phosphor, comprising Na, Dy, RE, Ga, In, and Ge, wherein the molar ratio of the metal elements is Na:Dy:RE:Ga:In:Ge=1:2x:2-2x:2:1:2, where: 0.01≤x<0.10, and x is the doping amount of dysprosium in the inert rare earth lattice sites;

[0011] RE is selected from either Gd or Y.

[0012] A method for preparing a dysprosium-activated garnet-based white phosphor includes the following steps:

[0013] S1: Weigh out the raw materials containing Na, Dy, RE, Ga, In and Ge according to their chemical composition;

[0014] S2: During the experiment, an additional 10% Ga2O3 was added to compensate for the loss of Ga during the high-temperature reaction. The mixture was thoroughly ground to ensure uniform mixing and then placed into the reaction vessel.

[0015] S3: Sintering is carried out in an atmospheric pressure air atmosphere, followed by cooling to room temperature and grinding to obtain the target phosphor for warm white WLED devices.

[0016] Preferably, the S3 sintering procedure involves heating from room temperature to 1200–1250°C at a rate of 5°C / min, maintaining the temperature at this point for 3–4 hours.

[0017] Preferably, the raw material containing Na is selected from sodium bicarbonate.

[0018] Preferably, the raw material containing Dy is selected from dysprosium oxide.

[0019] Preferably, the Ga-containing raw material is selected from gallium oxide.

[0020] Preferably, the raw material containing In is selected from indium oxide.

[0021] Preferably, the raw material containing Ge is selected from germanium oxide.

[0022] Preferably, when RE is selected from Gd, the raw material containing rare earth metal elements is selected from gadolinium oxide;

[0023] When RE is selected from Y, the raw material containing rare earth metal elements is selected from yttrium oxide.

[0024] (III) Beneficial Effects

[0025] Compared with the prior art, the present invention provides a dysprosium-activated garnet-based white light phosphor and its preparation method, which has the following beneficial effects:

[0026] 1. The dysprosium-activated garnet-based white light phosphor and its preparation method, a. The solid-phase synthesis reaction temperature is reduced: the solid-phase synthesis reaction temperature of the novel matrix is ​​significantly reduced to the range of 1200-1250℃, and phase formation is only required in 3 hours. The crystallinity is intact, which reduces energy consumption and preparation cost;

[0027] b. No co-solvent required: The preparation process of phosphors does not require the use of co-solvents, reducing the impact on the environment;

[0028] c. One-step sintering: The preparation process is simplified to one-step sintering, which improves the preparation efficiency and the feasibility of the production process;

[0029] d. No specific pressure and atmosphere requirements: The preparation process does not require specific pressure and atmosphere requirements, which reduces the limitations and complexity of process conditions.

[0030] 2. The dysprosium-activated garnet-based white light phosphor and its preparation method. The phosphor of this invention utilizes Dysprosium... 3 In an eight-coordinate lattice environment within a garnet matrix, it exhibits multi-peak emission. Excited by 300-320 nm ultraviolet light and 360-410 nm near-ultraviolet light, it emits intense light with a dominant yellow peak at 583 nm, accompanied by multi-peak narrow-band emission of blue-green and red light at 460-500 nm and 660-680 nm. This gives the phosphor a broad excitation and emission coverage, making it suitable for various applications.

[0031] 3. The dysprosium-activated garnet-based white phosphor and its preparation method: The dysprosium-activated garnet-based white phosphor obtained by this invention exhibits remarkable advantages. Its wide effective excitation range and emission coverage, as well as its characteristics of being in the (0.404, 0.403) color coordinate range and 3600K-4000K color temperature range, endow this phosphor with potential application value in warm white WLED devices. Attached Figure Description

[0032] Figure 1 The Dy prepared in Example 3 3+ X-ray powder diffraction pattern of doped sodium yttrium gallium indium germanium garnet-based dysprosium activated garnet-based white phosphor;

[0033] Figure 2 The Dy prepared in Example 3 3+ Fluorescence emission spectrum of doped sodium yttrium gallium indium germanium garnet-based dysprosium activated garnet-based white phosphor;

[0034] Figure 3 The Dy prepared in Example 3 3+ Fluorescence excitation spectrum of doped sodium yttrium gallium indium germanium garnet-based dysprosium activated garnet-based white phosphor;

[0035] Figure 4 The Dy prepared in Example 3 3+ Color coordinate diagram of doped sodium yttrium gallium indium germanium garnet-based dysprosium activated garnet-based white phosphor. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Combination Figures 1-4 A dysprosium-activated garnet-based white light phosphor and its preparation method are described in the following examples:

[0038] Example 1:

[0039] Weigh out 0.0840 g of sodium bicarbonate (NaHCO3), 0.3589 g of gadolinium oxide (Gd2O3), 0.0037 g of dysprosium oxide (Dy2O3), 0.2093 g of germanium oxide (GeO2), 0.2062 g of gallium oxide (Ga2O3), and 0.1388 g of indium oxide (In2O3). Grind the above raw materials in an agate mortar until uniform. Then, carry out a solid-state reaction. Under normal pressure and air atmosphere, heat to 1200℃ at a rate of 5℃ / min and hold at that temperature for 3 hours. After cooling, grind until uniform to obtain dysprosium-activated garnet-based white phosphor.

[0040] Example 2:

[0041] Weigh out 0.0840 g of sodium bicarbonate (NaHCO3), 0.2236 g of yttrium oxide (Y2O3), 0.0037 g of dysprosium oxide (Dy2O3), 0.2093 g of germanium oxide (GeO2), 0.2062 g of gallium oxide (Ga2O3), and 0.1388 g of indium oxide (In2O3). Grind the above raw materials in an agate mortar until uniform. Then, carry out a solid-state reaction. Under normal pressure and air atmosphere, heat to 1200℃ at a rate of 5℃ / min and hold at that temperature for 3 hours. After cooling, grind until uniform to obtain dysprosium-activated garnet-based white phosphor.

[0042] Example 3:

[0043] Weigh out 0.0840 g of sodium bicarbonate (NaHCO3), 0.3516 g of gadolinium oxide (Gd2O3), 0.0112 g of dysprosium oxide (Dy2O3), 0.2093 g of germanium oxide (GeO2), 0.2062 g of gallium oxide (Ga2O3), and 0.1388 g of indium oxide (In2O3). Grind the above raw materials in an agate mortar until uniform. Then, carry out a solid-state reaction. Under normal pressure and air atmosphere, heat to 1200℃ at a rate of 5℃ / min and hold at that temperature for 4 hours. After cooling, grind until uniform to obtain dysprosium-activated garnet-based white phosphor.

[0044] Example 4:

[0045] Weigh out 0.0840 g of sodium bicarbonate (NaHCO3), 0.2190 g of yttrium oxide (Y2O3), 0.0112 g of dysprosium oxide (Dy2O3), 0.2093 g of germanium oxide (GeO2), 0.2062 g of gallium oxide (Ga2O3), and 0.1388 g of indium oxide (In2O3). Grind the above raw materials in an agate mortar until uniform. Then, carry out a solid-state reaction. Under normal pressure and air atmosphere, heat to 1200℃ at a rate of 5℃ / min and hold at that temperature for 4 hours. After cooling, grind until uniform to obtain dysprosium-activated garnet-based white phosphor.

[0046] Based on the above, the phosphor of the present invention utilizes Dy 3+ Multi-peak luminescence can occur in the eight-coordinate lattice environment of garnet. Besides the yellow luminescence of the main peak, Dy... 3+ Ions can also emit blue-green and red light through other electronic transition processes. These peaks are typically located between 460-500 nm and 660-680 nm. The phosphor proposed in this invention utilizes a novel garnet matrix constructed from sodium, yttrium / gadolinium, gallium, indium, and germanium. Compared to traditional garnet isomorphic systems constructed from aluminum, silicon, and alkaline earth metals, the solid-phase synthesis reaction temperature is significantly lower, and no co-solvent is required. It can be sintered in one step, and the reaction process has no specific pressure or atmosphere requirements.

[0047] This invention also protects the above-mentioned Dy 3+ Application of doped sodium yttrium / sodium gadolinium gallium indium germanium garnet-based dysprosium activated garnet-based white phosphor in light-emitting devices. The Dy... 3+ Doped sodium yttrium / sodium gadolinium gallium indium germanium garnet-based dysprosium activated garnet-based white phosphors have a wide effective excitation range and a wide emission coverage range, and can be used in warm white WLED devices for home lighting, commercial lighting and automotive lighting.

[0048] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A dysprosium-activated garnet-based white phosphor, characterized in that, The metals include Na, Dy, RE, Ga, In, and Ge, with the molar ratio of the metal elements being Na:Dy:RE:Ga:In:Ge = 1:

2. x :2-2 x :2:1:2, where: 0.01≤x<0.10, x This represents the doping amount of dysprosium at inert rare earth sites; RE is selected from either Gd or Y.

2. The method for preparing a dysprosium-activated garnet-based white light phosphor as described in claim 1, characterized in that, Includes the following steps: S1: Weigh out the raw materials containing Na, Dy, RE, Ga, In and Ge according to their chemical composition; S2: During the experiment, an additional 10% Ga2O3 was added to compensate for the loss of Ga during the high-temperature reaction. The mixture was thoroughly ground to ensure uniform mixing and then placed into the reaction vessel. S3: Sintering is carried out in an atmospheric pressure air atmosphere, followed by cooling to room temperature and grinding to obtain the target phosphor for warm white WLED devices.

3. The method for preparing a dysprosium-activated garnet-based white phosphor according to claim 2, characterized in that: The S3 sintering procedure is as follows: the temperature is increased from room temperature to 1200–1250℃ at a rate of 5℃ / min, and then held at a constant temperature for 3–4 hours after the temperature increase is completed.

4. The method for preparing a dysprosium-activated garnet-based white phosphor according to claim 2, characterized in that: The raw material containing Na is selected from sodium bicarbonate.

5. The method for preparing a dysprosium-activated garnet-based white phosphor according to claim 2, characterized in that: The raw materials containing Dy are selected from dysprosium oxide.

6. The method for preparing a dysprosium-activated garnet-based white phosphor according to claim 2, characterized in that: The raw materials containing Ga are selected from gallium oxide.

7. The method for preparing a dysprosium-activated garnet-based white phosphor according to claim 2, characterized in that: Raw materials containing In are selected from indium oxide.

8. The method for preparing a dysprosium-activated garnet-based white phosphor according to claim 2, characterized in that: The raw material containing Ge is selected from germanium oxide.

9. The method for preparing a dysprosium-activated garnet-based white phosphor according to claim 2, characterized in that: When RE is selected from Gd, the raw material containing rare earth metal elements is selected from gadolinium oxide; When RE is selected from Y, the raw material containing rare earth metal elements is selected from yttrium oxide.

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