Double-perovskite near-infrared luminescent material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of luminescent materials, and discloses a double-perovskite near-infrared luminescent material and a preparation method and application thereof. The chemical formula of the double-perovskite near-infrared luminescent material is represented as A1 + x / 2M < 1-x > / 2Mg < 1-x > FexTeO6, wherein A is selected from K or / and Na; m is selected from La or / and Gd; 0.0001 < = x < = 0.1. The excitation spectrum of the double-perovskite near-infrared light-emitting material covers the wave band of 300-400 nm, the emission spectrum of the double-perovskite near-infrared light-emitting material covers 850-920 nm, and the double-perovskite near-infrared light-emitting material has high internal quantum efficiency and can meet the development requirements of wide-spectrum near-infrared LED devices.

Description

Technical Field

[0001] The present invention belongs to the technical field of luminescent materials, and more specifically, relates to a double perovskite near-infrared luminescent material, a preparation method thereof, and an application thereof. Background Art

[0002] Near-infrared light has been widely used in multiple fields such as food quality analysis, night vision monitoring, and biomedicine. Traditional infrared light sources have the characteristics of large volume and low efficiency, and they can no longer meet people's needs for miniaturized and portable NIR light sources. The phosphor-converted near-infrared light-emitting diode (pc-NIR-LED) can achieve miniaturization and wide-spectrum emission by designing and optimizing the structure and performance of NIR phosphors, better meeting the requirements of portable NIR detection. Moreover, it also has unique advantages such as adjustable spectrum, high efficiency, low cost, and low energy consumption. Therefore, studying how to improve the design and preparation process of phosphors to enhance their luminous efficiency and spectral width plays a crucial role in promoting the practical application of near-infrared light.

[0003] The double perovskite structure has been attracting research attention in recent years. Compared with perovskite, it can provide more lattice sites to substitute various elements, especially the lattice frameworks formed by high-valence ions such as Nb 5+ , Sb 5+ , Te 6+ and W 6+ . Among the phosphors activated by many different ions, Fe 3+ ions are low-cost, non-toxic, and have the characteristic of strong near-infrared light emission. They are more meaningful for research compared to the materials doped with toxic Cr 3+ ions. Currently, there have been reports on Fe 3+ -doped double perovskite near-infrared materials, which can emit excellent near-infrared light. For example, the team of Teng Bing from Qingdao University developed the CaLaMgSbO 6 :Fe 3+ material (Adv. Opt. Mater. 2024, 12, 2302383). The emission peak wavelength of this material is 995 nm, and the internal quantum efficiency is 54.05%; the team of Li Ling from Hubei University developed the Ca 2 LuSbO 6 :Fe 3+ material (J. Am. Ceram. Soc. 2024, 107, 2371 - 2383). The emission peak wavelength of this material is 927 nm, and the internal quantum efficiency is 69%. These all have certain commercialization potential. However, the AA'BB'O of their double perovskite 6In [the materials], B' all selects the toxic Sb element, and their internal quantum efficiencies are all relatively low, which greatly limits the practical applications of such materials. Therefore, it is of great significance to find environmentally friendly elements to replace them and further improve the internal quantum efficiency. Summary of the Invention

[0004] In order to solve the above-mentioned deficiencies and drawbacks of the prior art, the object of the present invention is to provide a double perovskite near-infrared luminescent material. The excitation spectrum of this near-infrared luminescent material covers the 300-400 nm band, the emission spectrum covers 850-920 nm, and the luminescence efficiency and internal quantum efficiency are high (more than 70%), which can meet the requirements for the development of wide-spectrum near-infrared LED devices.

[0005] Another object of the present invention is to provide a preparation method for the above-mentioned double perovskite near-infrared luminescent material. This method is simple and easy to operate, easy to mass-produce, and pollution-free.

[0006] Another object of the present invention is to provide the application of the above-mentioned double perovskite near-infrared luminescent material.

[0007] The object of the present invention is achieved by the following technical solutions:

[0008] The chemical formula of a double perovskite near-infrared luminescent material is A 1+x / 2 M 1-x / 2 Mg 1-x Fe x TeO 6 ; where A is selected from K or / and Na; M is selected from La or / and Gd; 0.0001 ≤ x ≤ 0.1.

[0009] The preparation method of the above-mentioned double perovskite near-infrared luminescent material includes the following specific steps:

[0010] S1. Mix and grind the A compound, M compound, Mg compound, Te compound, and Fe compound evenly to obtain a mixture;

[0011] S2. Sinter the mixture at 900-1100 °C, and crush and grind the product to obtain the double perovskite near-infrared luminescent material.

[0012] Preferably, in step S1, the A compound is one or more of sodium bicarbonate, sodium carbonate, sodium hydroxide, potassium carbonate, or potassium hydroxide.

[0013] Preferably, in step S1, the M compound is lanthanum oxide or gadolinium oxide; the Te compound is tellurium trioxide; the Fe compound is iron(III) oxide.

[0014] Preferably, in step S1, the Mg compound is one or more of magnesium carbonate, basic magnesium carbonate, magnesium oxide, magnesium hydroxide, or magnesium nitrate.

[0015] Preferably, the sintering time in step S2 is 4 to 16 h.

[0016] Application of the double perovskite near-infrared luminescent material in a light conversion device.

[0017] Preferably, the light conversion device is a near-infrared LED device.

[0018] The present invention dissolves the optically active element Fe 3+ in the A 1 with a double perovskite structure of space group P12 1+x / 2 M 1-x / 2 Mg 1-x TeO 6 (A = K or / and Na; M = La or / and Gd) crystal phase to obtain a brand-new material system with high luminous efficiency, whose excitation spectrum covers the 300 - 400 nm band and the emission peak wavelength is located at 850 - 920 nm. It belongs to a new combination compound and has potential application value.

[0019] The present invention includes Fe 3+ individually doped A 1+x / 2 M 1-x / 2 Mg 1-x TeO 6 (A = K or / and Na; M = La or / and Gd) near-infrared luminescent material, and on this basis, new-component near-infrared luminescent materials are formed by changing the K / Na components and the La / Gd ratio. This material uses a double perovskite with a P12 1 / m1 space group as the matrix. Compared with other perovskite materials, the materials under this space group have a higher distortion degree, can effectively break the forbidden nature of the 3d-3d transition of trivalent iron ions, and achieve high-efficiency luminescence. In the double perovskite structure AA'BB'O 6 , when B' selects Te compared with Sb, it is non-toxic and has a stronger crystal field effect, and the excitation and emission wavelengths may shift to the short-wave direction (blue shift), thereby achieving a higher internal quantum efficiency. In the present invention, A and A' can utilize the ionic radius difference to construct crystal fields with different intensities to achieve the regulation of the peak wavelength, and the precise regulation of the emission peak position can be achieved by adjusting the ratio between K, Na, La, and Gd.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The double perovskite near-infrared luminescent material of the present invention emits near-infrared light with high efficiency under the excitation of 340 nm ultraviolet light, covering 850 - 920 nm, and can be used as a broadband phosphor for near-infrared LEDs for fluorescence conversion.

[0022] 2. The double perovskite near-infrared luminescent material of the present invention has a high internal quantum efficiency (above 70%), which can improve the energy efficiency of light conversion and the performance of luminescent components.

[0023] 3. The double perovskite structure near-infrared luminescent material of the present invention has a low synthesis temperature, a simple preparation process, does not require special reaction equipment, and is convenient for industrial production. Description of the Drawings

[0024] Figure 1 For K in Example 1 1.01 La 0.99 Mg 0.98 Fe 0.02 TeO 6 X-ray powder diffraction pattern.

[0025] Figure 2 For K in Example 1 1.01 La 0.99 Mg 0.98 Fe 0.02 TeO 6 Excitation spectrum.

[0026] Figure 3 For K in Example 1 1.01 La 0.99 Mg 0.98 Fe 0.02 TeO 6 Emission spectrum.

[0027] Figure 4 For Na in Example 2 1.005 La 0.995 Mg 0.99 Fe 0.01 TeO 6 Emission spectrum.

[0028] Figure 5 For Na in Example 3 1.005 Gd 0.995 Mg 0.99 Fe 0.01 TeO 6 Emission spectrum. Detailed Embodiments

[0029] The following further illustrates the content of the present invention with specific examples, but should not be construed as a limitation of the present invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in the technical field.

[0030] Example 1

[0031] Weigh 0.505 mol of K, all of which are of analytical purity 2 CO 3 , 0.495 mol of La 2 O 3 , 0.98 mol of MgO, 1 mol of TeO 2 and 0.01 mol of Fe 2 O 3 . After mixing them and grinding them thoroughly, load them into an alumina crucible, sinter at 900 °C and keep warm for 8 h. After cooling to room temperature, crush, grind, wash and dry the product to obtain the near-infrared luminescent material of K 1.01 La 0.99 Mg 0.98 Fe 0.02 TeO 6 .

[0032] Figure 1 is the X-ray powder diffraction pattern of K 1.01 La 0.99 Mg 0.98 Fe 0.02 TeO 6 in Example 1. As can be seen from Figure 1 , by comparing the X-ray powder diffraction pattern with the standard card of KLaMgTeO 6 , it shows that K 1.01 La 0.99 Mg 0.98 Fe 0.02 TeO 6 has been successfully prepared. Figure 2 is the excitation spectrum of K 1.01 La 0.99 Mg 0.98 Fe 0.02 TeO 6 in Example 1. As can be seen from Figure 2 , its optimal excitation spectrum is 340 nm. Figure 3 is the emission spectrum of K 1.01 La 0.99 Mg 0.98 Fe 0.02 TeO 6 in this example. As can be seen from Figure 3 , the peak value of the emission peak of K 1.01 La 0.99 Mg 0.98 Fe 0.02 TeO 6 is 856 nm. Under the excitation of 340 nm ultraviolet light, its internal quantum efficiency is 70%, as shown in Table 1.

[0033] Example 2

[0034] Weigh 0.5025 mol of Na, all of which is of analytical purity 2 CO 3 , 0.4975 mol of La 2 O 3 , 0.99 mol of MgO, 1 mol of TeO 2 and 0.005 mol of Fe 2 O 3 . After mixing them and grinding them evenly, put them into an alumina crucible, sinter at 900 °C and keep warm for 8 h. After cooling to room temperature, crush, grind, wash and dry the product to obtain the near-infrared luminescent material of Na 1.005 La 0.995 Mg 0.99 Fe 0.01 TeO 6 .

[0035] Figure 4 Figure 1.005 shows the emission spectrum of Na 0.995 La 0.99 Mg 0.01 Fe 6 TeO Figure 4 in this example. As can be seen from 1.005 Figure 0.995 , the peak value of the emission peak of Na 0.99 La 0.01 Mg 6 Fe

[0036] Example 3

[0037] Weigh 0.5025 mol of Na, all of which is of analytical purity 2 CO 3 , 0.4975 mol of Gd 2 O 3 , 0.99 mol of MgO, 1 mol of TeO 2 and 0.005 mol of Fe 2 O 3 . After mixing them and grinding them evenly, put them into an alumina crucible, sinter at 1100 °C and keep warm for 8 h. After cooling to room temperature, crush, grind, wash and dry the product to obtain the near-infrared luminescent material of Na 1.005 Gd 0.995 Mg 0.99 Fe 0.01 TeO 6 .

[0038] Figure 5 Figure 1.005 shows the emission spectrum of Na 0.995 Gd0.99 Fe 0.01 TeO 6 The emission spectrum of. As Figure 5 can be seen, Na 1.005 Gd 0.995 Mg 0.99 Fe 0.01 TeO 6 has an emission peak at 914 nm and an internal quantum efficiency of 76%, as shown in Table 1.

[0039] Example 4

[0040] Weigh 0.505 mol of Na 2 CO 3 , 0.495 mol of La 2 O 3 , 0.98 mol of MgO, 1 mol of TeO 2 and 0.01 mol of Fe 2 O 3 . Mix them well by grinding, put them into an alumina crucible, sinter at 900 °C and hold for 8 h. After cooling to room temperature, crush, grind, wash and dry the product to obtain the near-infrared luminescent material of Na 1.01 La 0.99 Mg 0.98 Fe 0.02 TeO 6 . Its emission peak is at 883 nm and the internal quantum efficiency is 93%, as shown in Table 1.

[0041] Example 5

[0042] Weigh 0.5025 mol of K 2 CO 3 , 0.4975 mol of La 2 O 3 , 0.99 mol of MgO, 1 mol of TeO 2 and 0.005 mol of Fe 2 O 3 . Mix them well by grinding, put them into an alumina crucible, sinter at 900 °C and hold for 8 h. After cooling to room temperature, crush, grind, wash and dry the product to obtain the near-infrared luminescent material of K 1.005 La 0.995 Mg 0.99 Fe 0.01 TeO 6 . Its emission peak is at 856 nm and the internal quantum efficiency is 84%, as shown in Table 1.

[0043] Example 6

[0044] Weigh 0.25 mol of Na, all of which are of analytical purity 2 CO 3 , 0.2525 mol of K 2 CO 3 , 0.4975 mol of La 2 O 3 , 0.99 mol of MgO, 1 mol of TeO 2 and 0.005 mol of Fe 2 O 3 . Mix them and grind thoroughly. Then put them into an alumina crucible, sinter at 900 °C and keep warm for 8 h. After cooling to room temperature, crush, grind, wash and dry the product to obtain the near-infrared luminescent material of Na 0. 5 K 0.505 La 0.995 Mg 0.99 Fe 0.01 TeO 6 . Its peak emission wavelength is 868 nm and the internal quantum efficiency is 85%, as shown in Table 1

[0045] Example 7

[0046] Weigh 0.505 mol of Na, all of which are of analytical purity 2 CO 3 , 0.25 mol of La 2 O 3 , 0.245 mol of Gd 2 O 3 , 0.98 mol of MgO, 1 mol of TeO 2 and 0.01 mol of Fe 2 O 3 . Mix them and grind thoroughly. Then put them into an alumina crucible, sinter at 900 °C and keep warm for 8 h. After cooling to room temperature, crush, grind, wash and dry the product to obtain the near-infrared luminescent material of Na 1.01 La 0.5 Gd 0.49 Mg 0.98 Fe 0.02 TeO 6 . Its peak emission wavelength is 897 nm and the internal quantum efficiency is 70%, as shown in Table 1

[0047] Table 1 shows the emission peak positions and internal quantum efficiencies of the phosphors in Examples 1-5 under 340 nm excitation

[0048]

[0049]

[0050] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A double perovskite near-infrared luminescent material, characterized in that: The chemical formula of the double perovskite near-infrared luminescent material is A 1+x / 2 M 1-x / 2 Mg 1-x Fe x TeO6; wherein A is selected from K and / or Na; M is selected from La and / or Gd; 0.0001≤x≤0.

1.

2. The method for preparing a double perovskite near-infrared luminescent material according to claim 1, characterized in that: The specific steps include: S1. The A compound, the M compound, the Mg compound, the Te compound and the Fe compound are mixed and ground uniformly to obtain a mixture; S2. Sinter the mixture at 900-1100° C., and crush and grind the product to obtain a double perovskite near-infrared luminescent material.

3. The method for preparing the double perovskite near-infrared luminescent material according to claim 2, characterized in that: In step S1, the compound A is one or more of sodium bicarbonate, sodium carbonate, sodium hydroxide, potassium carbonate or potassium hydroxide.

4. The method for preparing the double perovskite near-infrared luminescent material according to claim 2, characterized in that: In step S1, the M compound is lanthanum oxide or gadolinium oxide; the Te compound is tellurium trioxide; and the Fe compound is ferric oxide.

5. The method for preparing the double perovskite near-infrared luminescent material according to claim 2, characterized in that: The Mg compound in step S1 is one or more of magnesium carbonate, basic magnesium carbonate, magnesium oxide, magnesium hydroxide or magnesium nitrate.

6. The method for preparing a double perovskite near-infrared luminescent material according to claim 2, characterized in that: The sintering time in step S2 is 4 to 16 hours.

7. Use of the double perovskite near-infrared luminescent material according to claim 1 in a photoconversion device.

8. The use according to claim 7, characterized in that: The light conversion device is a near-infrared LED device.

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