Cationic substitution enhanced double perovskite near-infrared luminescent material and preparation method and application thereof

Abstract

The invention relates to a cation-substituted enhanced double-perovskite near-infrared luminescent material and a preparation method and application thereof, and belongs to the technical field of luminescent materials. The chemical composition general formula of the material is Ba2-x / yMx / ySc0. 98SbO6: 0.02 Fe < 3 + >, and when M is Mg < 2 + >, x is greater than or equal to 0 and less than or equal to 2; when M = Zn < 2 + >, 0 < = y < = 2. The material takes Fe < 3 + > as an active ion, and can generate 700-1100 nm broadband near-infrared emission under excitation of 340-365 nm ultraviolet light, and the main peak is about 840 nm. By introducing Zn < 2 + > or Mg < 2 + > to partially replace Ba < 2 + >, the local lattice environment of Fe < 3 + > can be regulated and controlled, so that the near-infrared luminous intensity of the material is improved by 5 times at most. The near-infrared luminescent material provided by the invention is simple in preparation process, single in phase and high in synthesis efficiency, and has excellent luminous intensity and thermal stability. A near-infrared LED device constructed on the basis of the material and a commercial ultraviolet LED chip shows relatively high luminous efficiency, and has potential application value in multiple fields such as night vision illumination, infrared sensing and optical communication.

Description

Technical Field

[0001] This invention belongs to the field of inorganic luminescent materials technology, and particularly relates to a cation-substituted enhanced double perovskite near-infrared luminescent material, its preparation method, and its application. Background Technology

[0002] Near-infrared light, with its unique advantages such as strong penetration, minimal damage to biological tissues, and resistance to interference from ambient light, has shown broad application prospects in various fields including night vision lighting, infrared sensing, optical communication, biomedical imaging, and food detection. With the rapid development of these fields, the demand for high-performance near-infrared luminescent materials is becoming increasingly urgent, especially those that are compatible with commercial ultraviolet / blue LED chips, exhibit high luminous intensity, excellent thermal stability, and simple fabrication processes. These materials have become one of the current research hotspots in the field of luminescent materials.

[0003] Currently reported near-infrared luminescent materials mainly include rare-earth ion / transition metal ion activated near-infrared luminescent materials and quantum dot-based near-infrared luminescent materials. Among them, rare-earth ions (such as Nd) are particularly active. 3+ Er 3+ Yb 3+ While near-infrared luminescent materials activated by rare earth elements (such as Fe) exhibit precise emission peak positions, they suffer from drawbacks such as scarce and expensive rare earth element resources and narrow emission spectral bandwidth, making them unsuitable for certain applications requiring broadband near-infrared light (e.g., infrared sensing, optical communication). Quantum dot-based near-infrared luminescent materials, on the other hand, face challenges such as poor chemical stability, high toxicity, and difficulty in large-scale preparation, limiting their widespread application in practical devices. Transition metal ions (such as Fe) 3+ Cr 3+ Ni 2+ Near-infrared luminescent materials activated by Fe (etc.) are gradually becoming an ideal alternative to rare-earth-based near-infrared luminescent materials due to their abundant resources, low cost, and ability to achieve broadband near-infrared emission. 3+ 3d ions 5 Electronic configurations can be generated in a crystal field 4 T 1g ( 4 G)→ 6 A 1g ( 6 The S-transition enables broadband near-infrared emission in the 700–1100 nm range, which is highly compatible with the application requirements of night vision lighting, infrared sensing, and other fields. Therefore, the development of Fe 3+ Activated near-infrared luminescent materials have significant practical value.

[0004] The choice of matrix material affects Fe 3+The luminescent properties of activated near-infrared luminescent materials are crucial. Double perovskite structures are widely used as matrices for luminescent materials due to their high structural rigidity, tunable crystal structure, and good chemical stability. However, existing Fe double perovskite matrix-based Fe... 3+ Activated near-infrared luminescent materials generally suffer from low luminescence intensity, making it difficult to meet the luminous efficiency requirements of practical devices. This is mainly due to Fe... 3+ The local lattice environment of ions in the matrix is ​​not ideal, resulting in a low probability of luminescence transitions. In addition, some materials also suffer from defects such as complex preparation processes, impure phases, and poor thermal stability, which further limit their industrial applications.

[0005] In order to improve Fe 3+ To activate the luminescence properties of double perovskite-based near-infrared luminescent materials, researchers have attempted various modification strategies, such as doping ion modulation and fabrication process optimization, but the results have been less than ideal. Among these, cation substitution, as an effective means of lattice environment modulation, has been proven to significantly affect the luminescence properties of the activating ions. However, current research on using Mg... 2+ Zn 2+ Divalent ions partially replace Ba at the A-site in the double perovskite matrix 2+ Ions, through the regulation of Fe 3+ Further research is needed on how the local lattice environment of ions can enhance near-infrared luminescence intensity.

[0006] Therefore, regarding the existing Fe 3+ Addressing the technical shortcomings of low luminescence intensity and complex fabrication processes in activated near-infrared luminescent materials, developing a dual perovskite-based near-infrared luminescent material with high luminescence intensity, excellent thermal stability, and simple fabrication process through a cation substitution strategy to regulate the lattice environment is of great significance for promoting the development of near-infrared LED devices and expanding their applications in related fields. This is also a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0007] This invention aims to solve the problems of the prior art mentioned above. It proposes a method for preparing a chemically stable, high-luminescence-intensity, and excellent-thermal-stability dual-perovskite-based broadband near-infrared luminescent material via cation substitution, along with its preparation method and applications. The technical solution of this invention is as follows:

[0008] A dual perovskite-based near-infrared luminescent material with the general chemical formula Ba 2-x / y M x / y Sc 0.98 SbO6:0.02Fe 3+ Where M = Mg 2+ When 0 ≤ x ≤ 2; when M = Zn 2+When y ≤ 2, 0 ≤ y ≤ 2.

[0009] This invention employs a cationic substitution strategy to achieve the desired effect with Mg. 2+ Or Zn 2+ Ba ion substitution at site A 2+ , change Fe 3+ The degree of atomic disorder and lattice distortion around the ion breaks the dd transition forbidden, thereby increasing the Fe... 3+ Luminous efficiency.

[0010] The Fe provided by this invention 3+ The activated broadband near-infrared luminescent material has an absorption range of 250 nm-450 nm, making it a perfect match for commercial ultraviolet LED chips. Its emission range is 700-1100 nm, exhibiting excellent luminescent performance.

[0011] Based on the cation substitution strategy, for Ba 2-x / y M x / y Sc 0.98 SbO6: 0.02Fe 3+ When M = Mg 2+ When x = 0, 0 ≤ x ≤ 2; preferably, 0 ≤ x ≤ 1; more preferably, x is 0.8. When x = 0.8, the luminous intensity of the material increases by a maximum of 5 times, exhibiting excellent luminous efficiency.

[0012] Based on the cation substitution strategy, for Ba 2-x / y M x / y Sc 0.98 SbO6: 0.02Fe 3+ When M = Zn 2+ When y = 0.5, 0 ≤ y ≤ 2, preferably 0 ≤ y ≤ 1, and even more preferably y = 0.5. At y = 0.5, the luminous intensity of the material increases by a maximum of 5.2 times, and it exhibits excellent thermal stability (58.6%@423 K). LED devices fabricated from this material also possess excellent luminous efficiency.

[0013] Furthermore, the present invention provides a method for preparing the above-mentioned broadband near-infrared luminescent material, comprising the following steps:

[0014] Preferably, the chemical formula is: Ba2Sc 0.98 Fe 0.02 SbO6, Ba 1.7 Mg 0.3 Sc 0.98 Fe 0.02 SbO6, Ba 1.5 Mg 0.5 Sc 0.98 Fe0.02 SbO6, Ba 1.2 Mg 0.8 Sc 0.98 Fe 0.02 SbO6, Ba 1.0 Mg 1.0 Sc 0.98 Fe 0.02 SbO6, Ba 1.7 Zn 0.3 Sc 0.98 Fe 0.02 SbO6, Ba 1.5 Zn 0.5 Sc 0.98 Fe 0.02 SbO6, Ba 1.2 Zn 0.8 Sc 0.98 Fe 0.02 SbO6, Ba 1.0 Zn 1.0 Sc 0.98 Fe 0.02 SbO6.

[0015] The preparation of the aforementioned near-infrared luminescent materials mainly employs a high-temperature solid-state method, including the following steps:

[0016] (1) According to the general formula Ba 2-x / y M x / y Sc 0.98 SbO6: 0.02Fe 3+ The raw materials are accurately weighed according to the stoichiometric ratio, when M = Mg. 2+ When 0 ≤ x ≤ 2; when M = Zn 2+ When y ≤ 2, 0 ≤ y ≤ 2;

[0017] (2) Add the raw materials from step (1) to ethanol and grind and mix them to obtain a raw material mixture;

[0018] (3) The raw material mixture from step (2) is calcined at high temperature in air atmosphere and then ground to obtain a double perovskite-based near-infrared luminescent material.

[0019] Furthermore, the raw materials for step (1) are as follows:

[0020] The barium source used is one or more of barium oxide, barium carbonate, or barium nitrate;

[0021] The zinc source used is one or more of zinc oxide, zinc carbonate, or zinc nitrate;

[0022] The magnesium source used is one or more of magnesium oxide, magnesium carbonate, or magnesium nitrate;

[0023] The antimony source used is one or more of antimony oxide and antimony chloride;

[0024] The iron source used is one or more of ferric oxide and ferric chloride.

[0025] Furthermore, the raw material mixing method in step (2) is grinding, the grinding time is 20-55 minutes, and 10-20 ml of ethanol needs to be added during the grinding process.

[0026] Furthermore, the calcination in step (3) involves placing the raw material mixture in an alumina crucible and using a tube furnace or box furnace. The calcination temperature is 1300-1500 ℃, the heating rate is 1-10 ℃ / min, and the holding time is 5-10 hours. The atmosphere is an air atmosphere.

[0027] Furthermore, step (3) grinding involves grinding the sintered body in a mortar for 5-25 minutes to obtain a double perovskite-based near-infrared luminescent material.

[0028] A near-infrared LED light-emitting device includes an ultraviolet chip and a near-infrared light-emitting material for LED packaging; the near-infrared light-emitting material is any of the broadband near-infrared light-emitting materials described in the above description.

[0029] The advantages and beneficial effects of this invention are as follows:

[0030] (1) Excellent and tunable luminescent performance (corresponding to claims 1-3): Under 340-365 nm ultraviolet light excitation, the material can generate broadband near-infrared emission covering 700-1100 nm, perfectly matching commonly used ultraviolet LED chips. This is achieved by introducing Zn... 2+ or Mg 3+ The cation substitution strategy of partially substituting Ba²⁺ can effectively regulate the activation ion Fe. 3+ The local crystal field environment was created, thereby increasing the near-infrared luminescence intensity to more than 5 times that of the unsubstituted sample, thus achieving effective control over the luminescence properties of the material.

[0031] (2) Good thermal stability (corresponding to claims 1-3): The material is based on a structurally stable double perovskite matrix, and the obtained product has a single phase and high crystallinity. The integrated luminescence intensity of the material at 423 K still remains at 50% of that at room temperature, proving that it has excellent thermal stability. The excellent thermal stability of the material enables it to maintain good luminous efficiency in the device's operating temperature range, ensuring reliability and service life in practical applications.

[0032] (3) Environmentally friendly and low-cost (corresponding to claims 1-3): using abundant and inexpensive Fe 3+As a luminescent center, it replaces some precious metals or rare earth ions, significantly reducing raw material costs while improving performance, and conforms to the concept of green and environmentally friendly material development.

[0033] (4) Simple preparation process and high synthesis efficiency (corresponding to claims 4-8): The preparation method of this material (usually high temperature solid-state method) is simple, has low equipment requirements, and is easy to scale up. The synthesis process is efficient and can directly obtain a pure final product, avoiding complex post-processing procedures, which helps to reduce production costs and ensure product consistency.

[0034] (5) High luminous efficacy and great application potential (corresponding to claim 9): The near-infrared LED device constructed using this material and commercial ultraviolet LED chips exhibits high luminous efficacy. This device can provide a compact, efficient and low-cost near-infrared light source solution for fields such as night vision lighting, biosensing, infrared monitoring and optical communication. Attached Figure Description

[0035] Figure 1 These are X-ray powder diffraction patterns of the double perovskite-based near-infrared luminescent materials prepared according to preferred embodiments 1-8 and comparative example 1 of this invention;

[0036] Figure 2 The excitation and emission spectra of the double perovskite-based near-infrared luminescent material prepared in Comparative Example 1 are shown.

[0037] Figure 3 The excitation spectra of the double perovskite-based near-infrared luminescent materials prepared in Comparative Example 1 and Examples 1-4 are shown.

[0038] Figure 4 The emission spectra of the double perovskite-based near-infrared luminescent materials prepared in Comparative Example 1 and Examples 1-4 are shown.

[0039] Figure 5 The excitation spectra of the double perovskite-based near-infrared luminescent materials prepared in Comparative Example 1 and Examples 5-8 are shown.

[0040] Figure 6 The emission spectra of the double perovskite-based near-infrared luminescent materials prepared in Comparative Example 1 and Examples 5-8 are shown.

[0041] Figure 7 This is the curve showing the relationship between the emission integral intensity and temperature of the double perovskite-based near-infrared luminescent material prepared in Example 6;

[0042] Figure 8 This is the electroluminescence spectrum of a near-infrared LED light-emitting device prepared by coating the double perovskite-based near-infrared luminescent material prepared in Example 6 onto a 365 nm ultraviolet LED chip. Detailed Implementation

[0043] The technical solutions of the present invention will be clearly and thoroughly described below with reference to the accompanying drawings. The described embodiments are merely some embodiments of the present invention.

[0044] The technical solution of the present invention to solve the above-mentioned technical problems is:

[0045] Comparative Example 1

[0046] This embodiment provides Ba2Sc 0.98 Fe 0.02 Preparation method of SbO6 (i.e., x = 0, y = 0).

[0047] To prepare 2 mmol of the target product, 0.7894 g of BaCO3, 0.3193 g of Sc2O3, 0.0032 g of Fe2O3, and 0.3235 g of Sb2O5 were weighed according to stoichiometric ratios, with a total mass of 1.4354 g for the mixed compound. The mixture was then ground in an agate mortar for 30 minutes until homogeneous. The resulting mixture was transferred to an alumina crucible and heated to 1400°C in an air atmosphere in a box furnace. After maintaining this temperature at 1400°C for 5 hours, the mixture was allowed to cool naturally to room temperature. The naturally cooled sample was then ground uniformly in an agate mortar to obtain the product with the chemical formula Ba2Sc. 0.98 Fe 0.02 Broadband near-infrared luminescent material of SbO6.

[0048] Example 1

[0049] This embodiment provides Ba 1.7 Mg 0.3 Sc 0.98 Fe 0.02 Preparation method of SbO6 (i.e., x = 0.3, y = 0).

[0050] To prepare 2 mmol of the target product, 0.6710 g of BaCO3, 0.0242 g of MgO, 0.3193 g of Sc2O3, 0.0032 g of Fe2O3, and 0.3235 g of Sb2O5 were weighed according to stoichiometric ratios, with a total mass of 1.3412 g for the mixed compound. The mixture was then ground in an agate mortar for 30 minutes until homogeneous. The resulting mixture was transferred to an alumina crucible and heated to 1400°C in an air atmosphere in a box furnace. After maintaining this temperature at 1400°C for 5 hours, the mixture was allowed to cool naturally to room temperature. The naturally cooled sample was then ground uniformly in an agate mortar to obtain the product with the chemical formula BaCO3. 1.7 Mg 0.3 Sc 0.98 Fe 0.02 Broadband near-infrared luminescent material of SbO6.

[0051] Example 2

[0052] This embodiment provides Ba 1.5 Mg 0.5 Sc 0.98 Fe 0.02 Preparation method of SbO6 (i.e., x = 0.5, y = 0).

[0053] To prepare 2 mmol of the target product, 0.5920 g of BaCO3, 0.0403 g of MgO, 0.3193 g of Sc2O3, 0.0032 g of Fe2O3, and 0.3235 g of Sb2O5 were weighed according to stoichiometric ratios, with a total mass of 1.2783 g for the mixed compound. The mixture was placed in an agate mortar and ground for 30 minutes until homogeneous. The resulting mixture was transferred to an alumina crucible and heated to 1400°C in an air atmosphere in a box furnace. After maintaining this temperature at 1400°C for 5 hours, the mixture was allowed to cool naturally to room temperature. The naturally cooled sample was then ground evenly in an agate mortar to obtain the product with the chemical formula BaCO3. 1.5 Mg 0.5 Sc 0.98 Fe 0.02 Broadband near-infrared luminescent material of SbO6.

[0054] Example 3

[0055] This embodiment provides Ba 1.2 Mg 0.8 Sc 0.98 Fe 0.02 Preparation method of SbO6 (i.e., x = 0.8, y = 0).

[0056] To prepare 2 mmol of the target product, 0.4736 g of BaCO3, 0.0645 g of MgO, 0.3193 g of Sc2O3, 0.0032 g of Fe2O3, and 0.3235 g of Sb2O5 were weighed according to stoichiometric ratios, with a total mass of 1.1841 g for the mixed compound. The mixture was then ground in an agate mortar for 30 minutes until homogeneous. The resulting mixture was transferred to an alumina crucible and heated to 1400°C in an air atmosphere in a box furnace. After maintaining this temperature at 1400°C for 5 hours, the mixture was allowed to cool naturally to room temperature. The naturally cooled sample was then ground uniformly in an agate mortar to obtain the product with the chemical formula BaCO3. 1.2 Mg 0.8 Sc 0.98 Fe 0.02 Broadband near-infrared luminescent material of SbO6.

[0057] Example 4

[0058] This embodiment provides Ba 1.0 Mg 1.0 Sc 0.98 Fe 0.02 Preparation method of SbO6 (i.e., x = 1.0, y = 0).

[0059] To prepare 2 mmol of the target product, 0.3947 g of BaCO3, 0.0806 g of MgO, 0.3193 g of Sc2O3, 0.0032 g of Fe2O3, and 0.3235 g of Sb2O5 were weighed according to stoichiometric ratios, with a total mass of 1.1213 g for the mixed compound. The mixture was then ground in an agate mortar for 30 minutes until homogeneous. The resulting mixture was transferred to an alumina crucible and heated to 1400°C in an air atmosphere in a box furnace. After maintaining this temperature at 1400°C for 5 hours, the mixture was allowed to cool naturally to room temperature. The naturally cooled sample was then ground uniformly in an agate mortar to obtain the product with the chemical formula BaCO3. 1.0 Mg 1.0 Sc 0.98 Fe 0.02 Broadband near-infrared luminescent material of SbO6.

[0060] Example 5

[0061] This embodiment provides Ba 1.7 Zn 0.3 Sc 0.98 Fe 0.02 Preparation method of SbO6 (i.e., x = 0, y = 0.3).

[0062] To prepare 2 mmol of the target product, 0.6710 g of BaCO3, 0.0488 g of ZnO, 0.3193 g of Sc2O3, 0.0032 g of Fe2O3, and 0.3235 g of Sb2O5 were weighed according to stoichiometric ratios, with a total mass of 1.3658 g for the mixed compound. The mixture was placed in an agate mortar and ground for 30 minutes until homogeneous. The resulting mixture was transferred to an alumina crucible and heated to 1400°C in an air atmosphere in a box furnace. After maintaining this temperature at 1400°C for 5 hours, the mixture was allowed to cool naturally to room temperature. The naturally cooled sample was then ground evenly in an agate mortar to obtain the product with the chemical formula BaCO3. 1.7 Zn 0.3 Sc 0.98 Fe 0.02 Broadband near-infrared luminescent material of SbO6.

[0063] Example 6

[0064] This embodiment provides Ba 1.5 Zn 0.5 Sc0.98 Fe 0.02 Preparation method of SbO6 (i.e., x = 0, y = 0.5).

[0065] To prepare 2 mmol of the target product, 0.5920 g of BaCO3, 0.0814 g of ZnO, 0.3193 g of Sc2O3, 0.0032 g of Fe2O3, and 0.3235 g of Sb2O5 were weighed according to stoichiometric ratios, with a total mass of 1.3194 g for the mixed compound. The mixture was then ground in an agate mortar for 30 minutes until homogeneous. The resulting mixture was transferred to an alumina crucible and heated to 1400°C in an air atmosphere in a box furnace. After maintaining this temperature at 1400°C for 5 hours, the mixture was allowed to cool naturally to room temperature. The naturally cooled sample was then ground uniformly in an agate mortar to obtain the product with the chemical formula BaCO3. 1.5 Zn 0.5 Sc 0.98 Fe 0.02 Broadband near-infrared luminescent material of SbO6.

[0066] Example 7

[0067] This embodiment provides Ba 1.2 Zn 0.8 Sc 0.98 Fe 0.02 Preparation method of SbO6 (i.e., x = 0, y = 0.8).

[0068] To prepare 2 mmol of the target product, 0.4736 g of BaCO3, 0.1302 g of ZnO, 0.3193 g of Sc2O3, 0.0032 g of Fe2O3, and 0.3235 g of Sb2O5 were weighed according to stoichiometric ratios, with a total mass of 1.2498 g for the mixed compound. The mixture was placed in an agate mortar and ground for 30 minutes until homogeneous. The resulting mixture was transferred to an alumina crucible and heated to 1400°C in an air atmosphere in a box furnace. After maintaining this temperature at 1400°C for 5 hours, the mixture was allowed to cool naturally to room temperature. The naturally cooled sample was then ground evenly in an agate mortar to obtain the product with the chemical formula Ba. 1.2 Zn 0.8 Sc 0.98 Fe 0.02 Broadband near-infrared luminescent material of SbO6.

[0069] Example 8

[0070] This embodiment provides Ba 1.0 Zn 1.0 Sc 0.98 Fe 0.02Preparation method of SbO6 (i.e., x = 0, y = 1.0).

[0071] To prepare 2 mmol of the target product, 0.3947 g of BaCO3, 0.1628 g of ZnO, 0.3193 g of Sc2O3, 0.0032 g of Fe2O3, and 0.3235 g of Sb2O5 were weighed according to stoichiometric ratios, with a total mass of 1.2035 g for the mixed compound. The mixture was placed in an agate mortar and ground for 30 minutes until homogeneous. The resulting mixture was transferred to an alumina crucible and heated to 1400°C in an air atmosphere in a box furnace. After maintaining this temperature at 1400°C for 5 hours, the mixture was allowed to cool naturally to room temperature. The naturally cooled sample was then ground uniformly in an agate mortar to obtain the product with the chemical formula BaCO3. 1.0 Zn 1.0 Sc 0.98 Fe 0.02 Broadband near-infrared luminescent material of SbO6.

[0072] Figure 1 Fe prepared in Examples 1-8 and Comparative Example 1 are shown. 3+ X-ray powder diffraction patterns of activated double perovskite near-infrared luminescent materials were obtained. The diffraction peaks of all materials showed good agreement with the comparative double perovskite structure standard card, and no impurity phase peaks were observed, confirming the successful synthesis of the target material with a single phase and good crystallinity using the described preparation method.

[0073] Figure 2 The excitation and emission spectra of the sample in Comparative Example 1 are shown. This material exhibits a strong excitation peak near 345 nm; it also displays broadband near-infrared emission centered at ~840 nm in the 700–1100 nm range, attributed to Fe. 3+ of 4 T 1g ( 4 G)→ 6 A 1g ( 6 S) transition.

[0074] Figure 3 Comparative Example 1 and Examples 1-4 (Mg) 2+ The excitation spectrum (with changes in the amount of substitution x) was obtained. As x increased, the excitation peak red-shifted from the original 345 nm (Comparative Example 1) to 365 nm, which further optimized the matching degree between the material and the more mature 365 nm ultraviolet LED chip.

[0075] Figure 4 Comparative Example 1 and Examples 1-4 (Mg) 2+The emission spectrum of Mg (with variations in substitution amount x) was analyzed. Compared to Comparative Example 1 (x = 0), the near-infrared emission intensity of the material significantly increased with increasing x, reaching a maximum increase of 5-fold at x = 0.8, demonstrating that Mg... 2+ Introducing Fe that can be effectively controlled 3+ This local environment enhances the luminescence efficiency of Fe3+ ions.

[0076] Figure 5 and Figure 6 Comparative Example 1 and Examples 5-8 (Zn) are shown. 2+ The excitation and emission spectra of the substitution amount (y) change. Similarly, as y increases, the excitation peak also redshifts from 345 nm (Comparative Example 1) to 365 nm (Example 6), making it a better match for the more mature 365 nm ultraviolet chip. Figure 5 Furthermore, the near-infrared emission intensity was increased to a maximum of 5.2 times that of Comparative Example 1. Figure 6 This further verifies the universality and effectiveness of the cation substitution strategy in enhancing luminescence intensity.

[0077] Figure 7 The graph shows the relationship between the emission integral intensity and temperature for the sample in Example 6. When the temperature rises to 423 K, its emission integral intensity still maintains 58.6% of that at room temperature, demonstrating excellent thermal stability. This means that the material possesses reliable performance at the actual operating temperature of the device.

[0078] Figure 8 The electroluminescence spectrum of a near-infrared LED light-emitting device based on the material of Example 6 and packaged with a 365 nm ultraviolet LED chip is shown. The figure reveals that the emission peak of this material is significantly larger than that of the 365 nm chip, making the 365 nm chip peak invisible. Furthermore, as the driving current gradually increases, the device consistently outputs stable near-infrared light with gradually increasing luminous intensity, demonstrating that this near-infrared LED device has high light conversion efficiency and promising prospects for practical applications.

[0079] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0080] The above embodiments should be understood as illustrative only and not as limiting the scope of protection of the present invention. After reading the description of the present invention, those skilled in the art can make various alterations or modifications to the present invention, and these equivalent changes and modifications also fall within the scope defined by the claims of the present invention.

Claims

1. A cation-substituted enhanced double perovskite near-infrared luminescent material, its preparation method, and its application, characterized in that, The general chemical formula is Ba 2-x / y M x / y Sc 0.98 SbO6: 0.02Fe 3+ Where M = Mg 2+ When 0 ≤ x ≤ 2; when M = Zn 2+ When y ≤ 2, 0 ≤ y ≤ 2.

2. The luminescent material according to claim 1, characterized in that, The condition is 0 ≤ x ≤ 1, 0 ≤ y ≤ 1.

3. The luminescent material according to claim 2, characterized in that, x = 0.8, y = 0.

5.

4. The near-infrared luminescent material according to claim 1, characterized in that, The chemical formula is: Ba2Sc 0.98 Fe 0.02 SbO6, Ba 1.7 Mg 0.3 Sc 0.98 Fe 0.02 SbO6, Ba 1.5 Mg 0.5 Sc 0.98 Fe 0.02 SbO6, Ba 1.2 Mg 0.8 Sc 0.98 Fe 0.02 SbO6, Ba 1.0 Mg 1.0 Sc 0.98 Fe 0.02 SbO6, Ba 1.7 Zn 0.3 Sc 0.98 Fe 0.02 SbO6, Ba 1.5 Zn 0.5 Sc 0.98 Fe 0.02 SbO6, Ba 1.2 Zn 0.8 Sc 0.98 Fe 0.02 SbO6, Ba 1.0 Zn 1.0 Sc 0.98 Fe 0.02 SbO6.

5. A method for preparing the near-infrared luminescent material according to any one of claims 1-4, characterized in that, Includes the following steps: (1) According to the general formula Ba 2-x / y M x / y Sc 0.98 SbO6: 0.02Fe 3+ The raw materials are accurately weighed according to the stoichiometric ratio, when M = Mg. 2+ When 0 ≤ x ≤ 2; when M = Zn 2+ When y ≤ 2, 0 ≤ y ≤ 2; (2) Add the raw materials from step (1) to ethanol and grind and mix them to obtain a raw material mixture; (3) The raw material mixture from step (2) is calcined at high temperature in an air atmosphere or an argon atmosphere, and then ground to obtain a double perovskite-based near-infrared luminescent material.

6. The method for preparing the dual perovskite-based near-infrared luminescent material according to claim 5, characterized in that, The raw materials for step (1) are as follows: The barium source used is one or more of barium oxide, barium carbonate, or barium nitrate; The zinc source used is one or more of zinc oxide, zinc carbonate, or zinc nitrate; The magnesium source used is one or more of magnesium oxide, magnesium carbonate, or magnesium nitrate; The antimony source used is one or more of antimony oxide and antimony chloride; The iron source used is one or more of ferric oxide and ferric chloride.

7. The preparation method according to claim 5, characterized in that, The raw material mixing method in step (2) is grinding, the grinding time is 20-55 minutes, and 10-20 ml of ethanol needs to be added during the grinding process.

8. The preparation method according to claim 5, characterized in that, The calcination in step (3) involves placing the raw material mixture in an alumina crucible and using a tube furnace or box furnace. The calcination temperature is 1300-1500 ℃, the heating rate is 1-10℃ / min, and the holding time is 5-10 hours. The atmosphere is an air atmosphere or a nitrogen atmosphere.

9. The preparation method according to claim 5, characterized in that, The grinding step (3) involves grinding the sintered body in a mortar for 5-25 minutes to obtain a double perovskite-based near-infrared luminescent material.

10. A near-infrared LED light-emitting device, characterized in that, It includes an ultraviolet chip and a near-infrared luminescent material for LED packaging; the near-infrared luminescent material is the broadband near-infrared luminescent material according to any one of claims 1 to 4.

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