Manganese-activated antimonic acid-based fluorescent powder as well as preparation method and application thereof

Abstract

The invention provides manganese-activated antimonic acid-based fluorescent powder as well as a preparation method and application thereof, and relates to the technical field of luminescent materials. The chemical formula of the antimonic acid-based fluorescent powder provided by the invention is (La1-xYx) 3Li5Sb2-yO12: yMn, x is more than 0 and less than or equal to 0.3, and y is more than or equal to 0.001 and less than or equal to 0.01. The luminous efficiency and thermal stability of the fluorescent powder can be improved by equivalently replacing La < 3 + > with Y < 3 + >, and red fluorescence with the wave band of 650-770 nm can be emitted under excitation of near ultraviolet light and blue light.

Description

Technical Field

[0001] The present invention relates to the technical field of luminescent materials, and in particular to a manganese-activated antimonate-based fluorescent powder and a preparation method and application thereof. Background Art

[0002] The use of red or far-infrared emitting phosphors for plant growth has become a research hotspot. 4+ The emission band of activated phosphor is 600-750nm, which matches the spectral range required for plant growth; its excitation band is under blue light excitation (430-490nm), which matches the emission band of blue light LED chips and has attracted much attention [ECS Journal of Solid State Science and Technology 9(1)(2020)016001)]. Manganese-activated garnet phosphor is a hot phosphor system for plant growth due to its high efficiency, good physical and chemical stability, and no pollutants in the preparation process [Journal of Luminescence 136(2013)17-25,ECS Meeting Abstracts MA2021-01(7)(2021)457].

[0003] Among the manganese-activated garnet-type luminescent materials, manganese-activated antimonate-based phosphor La3Li5Sb 1.998 O 12 :0.002Mn, its efficiency is high, about 86.64% of the standard BaSO4, quantum efficiency ~12%; excellent spectral thermal stability, T = 423K luminous intensity is 77.49% of T = 273K, thermal quenching temperature T 0.5 About 500K [Journal of the Less Common Metals 167 (1991) 381-385, Journal of Solid State Chemistry 180 (6) (2008) 1832-1839, Optical Materials 148 (2024) 114937]. Further improving its luminescence efficiency and optimizing its thermal stability are the interests of scholars. The use of partial cation substitution can improve the lattice order, increase the matrix crystal rigidity, and thus improve its luminescence efficiency and spectral thermal stability. [Ceramics International 49 (2023) 19412-19421, journal of alloys and compounds 934 (2023) 167927]. The use of divalent alkaline earth metal ions for partial non-equivalent substitution of La 3+ , such as using Ca 2+ Partially replace La3+ Synthesized Li6CaLa2Sb2O 12 :Mn phosphor, with a quantum efficiency of 13.53% and a thermal quenching temperature of T 0.5 is 410K[Journal of Luminescence 221(2020)117031]; Sr 2+ Partially replace La 3+ Synthesized Li6SrLa2Sb2O 12 :Mn 4+ The internal quantum efficiency of the phosphor is 18.24%, and the thermal quenching temperature T 0.5 is 370K [Materials Research Bulletin 133(2021)111040]. Its efficiency has been improved, but its thermal stability has been reduced.

[0004] Therefore, it is urgent to provide a solution to improve the above problems. Summary of the invention

[0005] The object of the present invention is to provide a manganese activated antimonate based phosphor and a preparation method and application thereof, by 3+ Equivalent replacement of La 3+ The luminous efficiency and thermal stability of the phosphor can be improved. The phosphor can emit red fluorescence in the wavelength range of 650nm-770nm under the excitation of near-ultraviolet light and blue light.

[0006] In the first aspect, the present invention provides a manganese-activated antimonate-based phosphor, the chemical formula of which is (La 1-x Y x )3Li5Sb 2-y O 12 :yMn, and 0<x≤0.3, 0.001≤y≤0.01.

[0007] Optionally, the luminescent band of the fluorescent powder under near-ultraviolet light or blue light excitation is 650nm-770nm.

[0008] In a second aspect, the present invention provides a method for preparing a manganese-activated antimonate-based phosphor, comprising: mixing a lanthanum compound, a yttrium compound, a lithium compound, an antimony compound, and a manganese compound in a metal element molar ratio of 3(1-x):3x:5:2-y:y, and ball-milling the mixture, and then calcining the mixture at 1000°C-1200°C to obtain a manganese-activated antimonate-based phosphor; wherein 0<x≤0.3, 0.001≤y≤0.01.

[0009] Optionally, calcining is performed at 1000° C.-1200° C. for 3 h-5 h.

[0010] Optionally, the sintering is performed in an oxygen-containing atmosphere at 1000° C.-1200° C.

[0011] Optionally, after calcination, cooling is performed to obtain manganese-activated antimonate-based phosphor.

[0012] Optionally, after calcination, the powder is ground to obtain a manganese-activated antimonate-based phosphor with a size of 1 μm to 5 μm.

[0013] In a third aspect, the present invention also provides an application of a manganese-activated antimonate-based phosphor. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A flow chart of a method for preparing a manganese-activated antimonate-based phosphor provided by the present invention;

[0015] Figure 2 Phase analysis diagram of manganese-activated antimonate-based phosphors prepared in Examples 1 to 5 and Comparative Example 1 of the present invention;

[0016] Figure 3 The fluorescence spectra of the manganese-activated antimonate-based phosphors prepared in Examples 1 to 5 and Comparative Example 1 of the present invention are shown;

[0017] Figure 4 The normalized luminescence intensity-absolute temperature curves of the manganese-activated antimonate-based phosphors prepared in Example 1, Example 4, and Comparative Example 1 of the present invention are shown. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be the common meanings understood by people with general skills in the field to which the present invention belongs.

[0019] The present invention provides a chemical formula represented by (La 1-x Y x )3Li5Sb 2-y O 12 :yMn manganese activated antimonate-based phosphor, and 0<x≤0.3, 0.001≤y≤0.01. 3+ Equivalent replacement of La 3+, which can improve the luminous efficiency and thermal stability of the phosphor. In addition, the luminous wavelength of the antimonate-based phosphor under the excitation of near-ultraviolet light (360nm-390nm) and blue light (430nm-490nm) is 650nm-770nm.

[0020] In fact, see Figure 1 The method for preparing the manganese-activated antimonate-based phosphor provided by the present invention comprises:

[0021] S1, mixing and ball-milling a lanthanum compound, a yttrium compound, a lithium compound, an antimony compound, and a manganese compound to obtain a mixed powder;

[0022] S2. calcining the mixed powder at 1000° C.-1200° C. to obtain manganese-activated antimonate-based phosphor.

[0023] Specifically, when the lanthanum compound, yttrium compound, lithium compound, antimony compound and manganese compound are mixed in step S1, the molar ratio of the metal elements is 3(1-x):3x:5:2-y:y, and 0<x≤0.3. In fact, some metal elements can be slightly excessive during the batching process to make up for the burn-off amount during the roasting process.

[0024] In some embodiments, the lanthanum compound used in step S1 includes lanthanum oxide (La2O3), the yttrium compound used includes yttrium trioxide (Y2O3), the lithium compound used includes lithium carbonate (Li2CO3), the antimony compound used includes antimony trioxide (Sb2O3), and the manganese compound used includes manganese carbonate (MnCO3).

[0025] In fact, when performing step S2, the mixed powder can be calcined in an oxygen-containing atmosphere at 1000°C-1200°C for 3h-5h, cooled to room temperature after calcination and ground and sieved to obtain a manganese-activated antimonate-based phosphor with a particle size of 1μm-5μm. Specifically, the oxygen-containing atmosphere can be an air atmosphere.

[0026] Example 1

[0027] This embodiment 1 provides a method for preparing a manganese-activated antimonate-based phosphor, comprising the following steps:

[0028] S1, based on the chemical formula (La 0.95 Y 0.05 )3Li5Sb 1.998 O 12 :0.002Mn: Lanthanum oxide, yttrium trioxide, lithium carbonate, antimony trioxide and manganese carbonate were mixed, and then ball-milled in a ball mill for 3 hours to obtain a mixed powder;

[0029] S2. The mixed powder is calcined at 1100° C. in an air atmosphere for 4 hours, cooled to room temperature, ground and sieved to obtain a manganese-activated antimonate-based phosphor.

[0030] Example 2

[0031] This embodiment 2 provides a method for preparing a manganese-activated antimonate-based phosphor. The difference from the embodiment 1 is that in step S1, based on (La 0.9 Y 0.1 )3Li5Sb 1.998 O 12 :0.002Mn for batching.

[0032] Example 3

[0033] This embodiment 3 provides a method for preparing a manganese-activated antimonate-based phosphor. The difference from the embodiment 1 is that in step S1, based on (La 0.85 Y 0.15 )3Li5Sb 1.998 O 12 :0.002Mn for batching.

[0034] Example 4

[0035] This embodiment 4 provides a method for preparing a manganese-activated antimonate-based phosphor. The difference from the embodiment 1 is that in step S1, based on (La 0.8 Y 0.2 )3Li5Sb 1.998 O 12 :0.002Mn for batching.

[0036] Example 5

[0037] Example 5 provides a method for preparing a manganese-activated antimonate-based phosphor, which is different from Example 1 in that in step S1, based on (La 0.75 Y 0.25 )3Li5Sb 1.998 O 12 :0.002Mn for batching.

[0038] Comparative Example 1

[0039] This comparative example 1 provides a method for preparing a manganese-activated antimonate-based phosphor. The difference from Example 1 is that in step S1, the phosphor is prepared based on La3Li5Sb 1.998 O 12 :0.002Mn for batching.

[0040] Performance Characterization

[0041] The manganese activated antimonate-based phosphors prepared in Examples 1 to 5 and Comparative Example 1 were characterized and compared with La3Li5Sb2O 12 (PDF80-1251) Standard cards for comparison Figure 2 As shown. Figure 2 It can be seen that after Y is added in Examples 1 to 5, Y partially replaces La and enters the crystal lattice, and the physical phase of the phosphor is not changed.

[0042] The manganese activated antimonate-based phosphors prepared in Examples 1 to 5 and Comparative Example 1 were characterized by fluorescence spectra. Figure 3 As shown. Figure 3 It can be seen that the fluorescence spectra of Examples 1 to 5 doped with Y do not change significantly. em =717nm) in the range of 250nm-500nm, the strongest peak is 344nm (corresponding to 4 A 2g → 4 T 1g Transition), the second strongest peak is 482nm (corresponding to 4 A 2g → 4 T 2g Transition); 344nm or 482nm is the excitation wavelength, and the emission spectrum falls between 650nm and 770nm, with the strongest peak at 710nm (corresponding to 2 E g → 4 A 2g ). In addition, with the increase of Y doping amount, the intensity of the emission spectrum first increases (x=0-0.2) and then decreases (x=0.3), and is optimal at x=0.2 (Example 4).

[0043] The quantum efficiency of the manganese-activated antimonate-based phosphors prepared in Examples 1 to 5 and Comparative Example 1 was measured, and the room temperature (298K) quantum efficiency is shown in Table 1. Similarly, with the increase of the Y doping amount, the room temperature quantum efficiency first increases (x=0-0.2) and then decreases (x=0.3), and is optimal when x=0.2 (Example 4).

[0044] The manganese-activated antimonate-based phosphors prepared in Examples 1 to 5 and Comparative Example 1 were subjected to variable temperature spectrum measurement using a steady-state transient fluorescence spectrometer (the measurement temperature range was 298K to 500K, and 298K, 360.5K, 423K, and 485.5K could be selected). The luminescence intensity at each temperature was obtained and normalized to the relative luminescence intensity at room temperature. The normalized intensity-absolute temperature curves of the phosphors in Example 1, Example 4, and Comparative Example 1 were plotted as follows: Figure 4 As shown, the thermal quenching temperature T 0.5The thermal quenching temperature measurement results are shown in Table 1. From Table 1 and Figure 4 It can be seen that the spectral thermal stability of the fluorescent powder increases after adding Y, T 0.5 It increases from 500K in Comparative Example 1 to 520K in Examples 1-5.

[0045] Table 1 Room temperature quantum efficiency and thermal quenching temperature of manganese activated antimonate based phosphors

[0046] Excitation wavelength (nm) Emission wavelength (nm) Quantum efficiency (%) <![CDATA[T 0.5 (K)]]> Comparative Example 1 334 717 12.0 500 Example 1 335 717 12.9 520 Example 2 341 717 14.8 520 Example 3 341 717 16.8 520 Example 4 355 717 24.2 520 Example 5 337 717 17.1 520

[0047] Although the embodiments of the present invention are described in detail above, it is obvious to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations are within the scope and spirit of the present invention as described in the claims. Moreover, the present invention described herein may have other embodiments and may be implemented or realized in a variety of ways.

Claims

1. A manganese-activated antimonate-based phosphor, characterized in that: The chemical formula of the antimonate-based phosphor is (La 1- x Y x )3Li5Sb 2-y O 12 :yMn, and 0<x≤0.3, 0.001≤y≤0.

01.

2. The manganese-activated antimonate-based phosphor according to claim 1, characterized in that: The luminescence wavelength band of the antimonate-based fluorescent powder under near-ultraviolet light and blue light excitation is 650nm-770nm.

3. A method for preparing a manganese-activated antimonate-based phosphor, characterized in that: include: Lanthanum compound, yttrium compound, lithium compound, antimony compound and manganese compound are mixed and ball-milled at a metal element molar ratio of 3(1-x):3x:5:2-y:y, and then calcined at 1000°C-1200°C to obtain manganese-activated antimonate-based phosphor; wherein 0<x≤0.3, 0.001≤y≤0.

01.

4. The preparation method according to claim 3, characterized in that: Calcinate at 1000-1200°C for 3h-5h; and / or, calcine in an oxygen-containing atmosphere at 1000-1200°C; and / or, cool after calcination to obtain manganese-activated antimonate-based phosphor; and / or, grind after calcination to obtain manganese-activated antimonate-based phosphor of 1μm-5μm.

5. Use of the manganese-activated antimonate-based phosphor according to any one of claims 1 to 2 or the manganese-activated antimonate-based phosphor prepared by the preparation method according to any one of claims 3 to 4.

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