A sodium-rich titanium-based garnet red light fluorescent powder and a preparation method thereof

Abstract

The present invention discloses a red light NaGd2Ga2InTi2O 3+ :Sm 3+ phosphor and its preparation method. A red light NaGd2Ga2InTi2O 12 :Sm 3+ phosphor, whose chemical composition expression formula is: NaGd 2(1‑x) Ga2InTi2O 12 :2xSm 3+ , where: 0 < x ≤ 0.10. The present invention provides a red light NaGd2Ga2InTi2O 12 :Sm 3+ phosphor and its preparation method. This red light NaGd2Ga2InTi2O 12 :Sm 3+ phosphor can be efficiently excited by 400 - 410 nm near-ultraviolet light and 455 - 475 nm blue light, emits red light with the strongest main peak at 616 nm, and at the same time is accompanied by multi-peak narrow-band luminescence in the orange to deep red light region of 565 - 660 nm. The color coordinates are located at (0.59, 0.41), and the fluorescence lifetime is on the order of 1 millisecond.

Description

Technical Field

[0001] This invention relates to the field of luminescent materials technology, and more particularly to a red-emitting NaGd2Ga2InTi2O 12 :Sm 3+ Phosphors and their preparation methods. Background Technology

[0002] As living standards improve, people's demands for the quality of indoor light sources are also increasing. However, currently, blue GaN chips excite yellow YAG:Ce light... 3+ The white light source designed with garnet phosphor has a low color rendering index, indicating a weak ability to render the true colors of illuminated objects. This is rooted in insufficient spectral coverage of the red light region in the white light source. The simplest way to improve this problem is to supplement the red light component of the spectrum. Therefore, the development of novel red phosphors has been a key focus of research in this field. Rare earth ions, particularly Sm... 3+ It is a common activator for inorganic red phosphors, and in inorganic compound systems composed of many different elements, it can obtain efficient narrow-band emission in the spectral region from orange to red. However, to obtain high-quality red light that is beneficial for improving the color rendering index, Sm 3+ The position and proportion of the main emission peak exhibited in the matrix compound are quite important. Optimal Sm 3+ The red peak should ideally be concentrated within the wavelength range of 600-630 nm. If the wavelength is shorter than 600 nm, the emitted color will be orange and will not adequately compensate for the lack of red light in the spectrum. If the wavelength is greater than 630 nm, although the emitted color will be red, it will be too far from the visually perceptible high-sensitivity center region, resulting in a decrease in perceptible luminous intensity and a compromise in lumen efficiency. In existing technologies, Sm... 3+ There are many reports on garnet-based phosphors as activators, including Y3Al5O 12 :Sm 3+ Y3Ga5O 12 :Sm 3+ etc., but in these Sm 3+ In activated garnet-based phosphors, 4 G 5 / 2 - 6 H 7 / 2 The optimal red peak corresponding to the transition has a low proportion, and its excitation intensity in the blue light region is also weak. From a spectral performance perspective, it is difficult to fully compensate for the red light in practical applications and improve the color rendering ability of the corresponding light-emitting devices. In addition, the samarium garnet-based phosphors that have been reported so far also face many problems that are not conducive to practical industrial applications, such as high synthesis temperature (>1400℃), high requirements for production equipment, and high cost of raw materials of the elements involved, resulting in poor economic benefits. Summary of the Invention

[0003] The present invention provides a red light NaGd2Ga2InTi2O 12 :Sm 3+ phosphor and a preparation method thereof. The red light NaGd2Ga2InTi2O 12 :Sm 3+ phosphor can be efficiently excited by near-ultraviolet light of 400 - 410 nm and blue light of 455 - 475 nm, emits red light with the strongest main peak at 616 nm, and simultaneously has multi-peak narrow-band luminescence in the orange to deep red light region of 565 - 660 nm. The color coordinates are located at (0.59, 0.41), and the fluorescence lifetime is on the order of 1 millisecond.

[0004] The object of the present invention is to propose a red light NaGd2Ga2InTi2O 12 :Sm 3+ phosphor, the chemical composition expression formula of which is: NaGd 2(1-x) Ga2InTi2O 12 :2xSm 3+ , where: 0 < x ≤ 0.10.

[0005] Another object of the present invention is to propose a preparation method of the above-mentioned red light NaGd2Ga2InTi2O 12 :Sm 3+ phosphor, including the following steps: Weigh raw materials containing sodium, gadolinium, gallium, indium, titanium and samarium elements according to the chemical composition. Among them, the molar ratio of each element is Na:Gd:Ga:In:Ti:Sm = 1:2 - 2x:2:1:2:2x, where: 0 < x ≤ 0.10. During the synthesis process, 10% of Ga2O3 and 10% of In2O3 need to be added additionally to compensate for the loss of Ga and In during the high-temperature reaction process. Grind them充分混合均匀并放入反应容器中,在常压空气气氛中进行烧结,后冷却至室温,将产物研磨即得所述的红光NaGd2Ga2InTi2O 12 :Sm 3+ phosphor.

[0006] The red light NaGd2Ga2InTi2O 12 :Sm 3+ phosphor proposed by the present invention充分利用了Sm 3+ 在含钠富钛石榴石基质中强烈的 4 G 5 / 2 - 6 H 7 / 2 跃迁获取高品质红光。本发明提出的红光NaGd2Ga2InTi2O 12 :Sm 3 +The phosphor, using a novel garnet matrix constructed from sodium, titanium, gallium, and indium, exhibits a significantly lower reaction temperature for solid-phase synthesis compared to traditional garnet isomorphic systems constructed from aluminum, silicon, and alkaline earth metals. The synthesis process does not require specific pressure or atmosphere. Compared to traditional germanium-containing garnet isomorphic systems, it demonstrates greater economic efficiency in terms of reactant raw material costs.

[0007] Preferably, the sodium-containing raw material is selected from one or more of sodium carbonate, sodium bicarbonate, and sodium oxalate.

[0008] Preferably, the raw material containing gadolinium is selected from one or more of gadolinium oxide, gadolinium oxalate, gadolinium carbonate, and gadolinium nitrate.

[0009] Preferably, the gallium-containing raw material is selected from gallium oxide.

[0010] Preferably, the indium-containing raw material is selected from indium oxide.

[0011] Preferably, the raw material containing titanium is selected from titanium oxide.

[0012] The samarium-containing raw materials are selected from one or more of samarium oxide, samarium oxalate, samarium carbonate, and samarium nitrate.

[0013] Preferably, the sintering procedure is as follows: the temperature is increased from room temperature to 1100-1300℃ at a rate of 5℃ / min, and then held at a constant temperature for 3-5 hours after the temperature increase is completed.

[0014] This invention also protects the above-mentioned near-infrared NaGd2Ga2InTi2O 12 :Sm 3+ Applications of phosphors in light-emitting devices. The near-infrared phosphor proposed in this invention has a wide effective excitation range and a wide emission coverage range, and can be applied in fields such as health lighting, plant lighting, temperature detection, and infrared recognition.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] (1) The red light NaGd2Ga2InTi2O proposed in this invention 12 :Sm 3+ Phosphors can be sintered in one step at temperatures as low as 1100℃, requiring only 3-5 hours to form a phase. They exhibit excellent crystallinity, high luminescence brightness, and short fluorescence lifetime, making them suitable as red light materials for excitation by ultraviolet, near-ultraviolet, and blue LED chips.

[0017] (2) The red light NaGd2Ga2InTi2O proposed in this invention 12 :Sm 3+Phosphors have advantages such as a wide excitation range, excellent red light peak position, inexpensive raw materials, simple manufacturing process, short synthesis time, low energy consumption, and easy industrialization.

[0018] (3) The red light NaGd2Ga2InTi2O proposed in this invention 12 :Sm 3+ The phosphor glows red in NaGd2Ga2InTi2O 12 :Sm 3+ The phosphor can be efficiently excited by 400-410nm near-ultraviolet light and 455-475nm blue light, emitting the strongest red light with a main peak at 616nm, accompanied by multi-peak narrowband emission in the 565-660nm orange to deep red light region. The color coordinates are located at (0.59, 0.41), and the fluorescence lifetime is on the order of 1 millisecond. It can be used in many fields such as full-spectrum health lighting, fluorescent temperature measurement, and fluorescent anti-counterfeiting. Attached Figure Description

[0019] Figure 1 The red-light NaGd2Ga2InTi2O prepared in Example 1 12 :Sm 3+ X-ray powder diffraction pattern;

[0020] Figure 2 The red-light NaGd2Ga2InTi2O prepared in Example 1 12 :Sm 3+ The fluorescence emission spectrum of phosphors;

[0021] Figure 3 The red-light NaGd2Ga2InTi2O prepared in Example 1 12 :Sm 3+ The fluorescence excitation spectrum of the phosphor;

[0022] Figure 4 The red-light NaGd2Ga2InTi2O prepared in Example 1 12 :Sm 3+ Chromaticity coordinates of phosphor.

[0023] Figure 5 The red-light NaGd2Ga2InTi2O prepared in Example 1 12 :Sm 3+ Fluorescence decay curve of phosphor. Detailed Implementation

[0024] The following embodiments are further illustrations of the present invention, but not limitations thereof. Unless otherwise specified, the equipment and reagents used in the present invention are commercially available products conventional in this technical field.

[0025] Example 1

[0026] Weigh out 0.0265g of sodium carbonate (Na₂CO₃), 0.1722g of gadolinium oxide (Gd₂O₃), 0.1031g of gallium oxide (Ga₂O₃), 0.0763g of indium oxide (In₂O₃), 0.0799g of titanium oxide (TiO₂), and 0.0087g of samarium oxide (Sm₂O₃). Grind the above raw materials in an agate mortar until uniform. After grinding, 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 red-light NaGd₂Ga₂InTi₂O. 12 :Sm 3+ Fluorescent powder.

[0027] Example 2

[0028] Weigh out 0.0265g of sodium carbonate (Na₂CO₃), 0.1722g of gadolinium oxide (Gd₂O₃), 0.1031g of gallium oxide (Ga₂O₃), 0.0763g of indium oxide (In₂O₃), 0.0799g of titanium oxide (TiO₂), and 0.0087g of samarium oxide (Sm₂O₃). Grind the above raw materials in an agate mortar until uniform. After grinding, carry out a solid-state reaction. Under normal pressure and air atmosphere, heat to 1100℃ at a rate of 5℃ / min and hold at that temperature for 5 hours. After cooling, grind until uniform to obtain red-lustered NaGd₂Ga₂InTi₂O. 12 :Sm 3+ Fluorescent powder.

[0029] Example 3

[0030] Weigh out 0.0265g of sodium carbonate (Na₂CO₃), 0.1722g of gadolinium oxide (Gd₂O₃), 0.1031g of gallium oxide (Ga₂O₃), 0.0763g of indium oxide (In₂O₃), 0.0799g of titanium oxide (TiO₂), and 0.0087g of samarium oxide (Sm₂O₃). 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 1300℃ at a rate of 5℃ / min and hold at that temperature for 3 hours. After cooling, grind until uniform to obtain red-light NaGd₂Ga₂InTi₂O. 12 :Sm 3+ Fluorescent powder.

[0031] Example 4

[0032] Weigh out 0.0265g of sodium carbonate (Na₂CO₃), 0.1631g of gadolinium oxide (Gd₂O₃), 0.1031g of gallium oxide (Ga₂O₃), 0.0763g of indium oxide (In₂O₃), 0.0799g of titanium oxide (TiO₂), and 0.0173g of samarium oxide (Sm₂O₃). 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 1250℃ at a rate of 5℃ / min and hold at that temperature for 4 hours. After cooling, grind until uniform to obtain red-light NaGd₂Ga₂InTi₂O. 12 :Sm 3+ Fluorescent powder.

[0033] Example 5

[0034] Weigh out 0.0265g of sodium carbonate (Na₂CO₃), 0.1631g of gadolinium oxide (Gd₂O₃), 0.1031g of gallium oxide (Ga₂O₃), 0.0763g of indium oxide (In₂O₃), 0.0799g of titanium oxide (TiO₂), and 0.0173g of samarium oxide (Sm₂O₃). 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 1250℃ at a rate of 5℃ / min and hold at that temperature for 4 hours. After cooling, grind until uniform to obtain red-light NaGd₂Ga₂InTi₂O. 12 :Sm 3+ Fluorescent powder.

[0035] Example 6

[0036] Weigh out 0.0265g of sodium carbonate (Na₂CO₃), 0.1794g of gadolinium oxide (Gd₂O₃), 0.1031g of gallium oxide (Ga₂O₃), 0.0763g of indium oxide (In₂O₃), 0.0799g of titanium oxide (TiO₂), and 0.0017g of samarium oxide (Sm₂O₃). 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 1250℃ at a rate of 5℃ / min and hold at that temperature for 4 hours. After cooling, grind until uniform to obtain red-light NaGd₂Ga₂InTi₂O. 12 :Sm 3+ Fluorescent powder.

[0037] Example 7

[0038] Weigh out 0.0420g of sodium bicarbonate (NaHCO3), 0.1794g of gadolinium oxide (Gd2O3), 0.1031g of gallium oxide (Ga2O3), 0.0763g of indium oxide (In2O3), 0.0799g of titanium oxide (TiO2), and 0.0017g of samarium oxide (Sm2O3). 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 1150℃ at a rate of 5℃ / min and hold at that temperature for 5 hours. After cooling, grind until uniform to obtain red-light NaGd2Ga2InTi2O3. 12 :Sm 3+ Fluorescent powder.

[0039] Example 8

[0040] Weigh out 0.0420g of sodium bicarbonate (NaHCO3), 0.1794g of gadolinium oxide (Gd2O3), 0.1031g of gallium oxide (Ga2O3), 0.0763g of indium oxide (In2O3), 0.0799g of titanium oxide (TiO2), and 0.0017g of samarium oxide (Sm2O3). 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 1300℃ at a rate of 5℃ / min and hold at that temperature for 3 hours. After cooling, grind until uniform to obtain red-lustered NaGd2Ga2InTi2O3. 12 :Sm 3+ Fluorescent powder.

[0041] The above are merely preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be considered as limitations on the present invention, and the scope of protection of the present invention should be determined by the scope defined in the claims. For those skilled in the art, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A red-light NaGd2Ga2InTi2O 12 :Sm 3+ The chemical composition of the phosphor is represented by: NaGd 2(1-x) Ga2InTi2O 12 :2xSm 3+ ,in: 0 < x ≤ 0.10。 2. The red-light NaGd2Ga2InTi2O as described in claim 1 12 :Sm 3+ A method for preparing phosphors, characterized in that, The process includes the following steps: Raw materials containing sodium, gadolinium, gallium, indium, titanium, and samarium are weighed according to their chemical composition. The molar ratio of each element is Na : Gd : Ga : In : Ti : Sm = 1 : 2-2x : 2 : 1 : 2 : 2x, where 0 < x ≤ 0.

10. During the synthesis process, 10% Ga2O3 and 10% In2O3 are added to compensate for the loss of Ga and In during the high-temperature reaction. The mixture is thoroughly ground to ensure uniform mixing and then placed in a reaction vessel for sintering in an atmospheric pressure air atmosphere. After cooling to room temperature, the product is ground to obtain the red-glossy NaGd2Ga2InTi2O. 12 :Sm 3+ Fluorescent powder.

3. The red-light NaGd2Ga2InTi2O according to claim 2 12 :Sm 3+ A method for preparing phosphors, characterized in that, The sodium-containing raw materials are selected from one or more of sodium carbonate, sodium bicarbonate, and sodium oxalate.

4. The red-light NaGd2Ga2InTi2O according to claim 2 12 :Sm 3+ A method for preparing phosphors, characterized in that, The raw materials containing gadolinium are selected from one or more of gadolinium oxide, gadolinium oxalate, gadolinium carbonate, and gadolinium nitrate.

5. The red-light NaGd2Ga2InTi2O according to claim 2 12 :Sm 3+ A method for preparing phosphors, characterized in that, The gallium-containing raw material is selected from gallium oxide.

6. The red-light NaGd2Ga2InTi2O according to claim 2 12 :Sm 3+ A method for preparing phosphors, characterized in that, The indium-containing raw material is selected from indium oxide.

7. The red-light NaGd2Ga2InTi2O according to claim 2 12 :Sm 3+ A method for preparing phosphors, characterized in that, The raw material containing titanium is selected from titanium oxide.

8. The red-light NaGd2Ga2InTi2O according to claim 2 12 :Sm 3+ A method for preparing phosphors, characterized in that, The samarium-containing raw materials are selected from one or more of samarium oxide, samarium oxalate, samarium carbonate, and samarium nitrate.

9. The red-light NaGd2Ga2InTi2O according to claim 2 12 :Sm 3+ A method for preparing phosphors, characterized in that, The specific sintering conditions are as follows: one-step sintering, temperature of 1100-1300 ℃, time of 3-5 h, and heating rate of 5 ℃ / min.

10. The red-light NaGd2Ga2InTi2O as described in claim 1 12 :Sm 3+ Applications of phosphors in light-emitting devices.

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