A method for preparing and applying highly efficient divalent manganese-based metal halide materials with tunable luminescence and emission wavelengths.
The preparation of divalent manganese-based metal halide phosphors by mechanochemical method solves the problems of harsh preparation conditions and unstable fluorescence performance in the existing technology, and realizes the application of divalent manganese-based metal halide materials with high efficiency luminescence and tunable emission wavelength for high-efficiency wide color gamut white LED devices.
Patent Information
- Application Number
- CN202211611538.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-12-14
- Publication Date
- 2025-10-28
- Estimated Expiration
- 2042-12-14
AI Technical Summary
Existing divalent manganese-based metal halide materials face challenges in commercialization, including demanding preparation conditions and unstable fluorescence performance. In particular, the preparation of high-performance single crystals is difficult, and the fluorescence performance of polycrystalline powders is poor, leading to unstable color rendering performance of LED devices.
A mechanochemical method was adopted, using tetramethylammonium halide and manganese halide as raw materials, to prepare [(CH3)4N]yMnXy+2 manganese-based metal halide phosphors by ball milling and washing. High-speed collision energy was used to crush the particles and the raw material ratio was changed to tune the emission wavelength, thus preparing highly efficient green and red light-emitting materials.
The fabrication of highly efficient luminescent materials has been achieved, with tunable emission wavelengths. When applied to white LED devices, the efficiency reaches 60.10–98.06 lm/W, and the color gamut covers 98–102% of the NTSC standard, exhibiting wide color gamut and high-efficiency display performance.
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Figure CN116178172B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of luminescent materials technology, and more particularly to a method for preparing divalent manganese-based metal halide materials and their application in the fields of lighting and display. Background Art
[0002] With the rapid development of information technology, wide color gamut display devices are attracting increasing attention. Currently, commercial liquid crystal display devices combine blue light chips with narrow-band emitting β-Si... 6–z Al z O z N 8–z Eu 2+ Green phosphor and K2SiF6:Mn 4+ Red phosphors can achieve over 90% color coverage of the National Television System Committee (NTSC) standard, resulting in lifelike displays. However, traditional narrow-band green phosphors suffer from drawbacks such as the use of large amounts of rare earth elements and demanding fabrication processes. In recent years, research has focused on developing novel rare-earth-free, low-cost, and high-performance phosphors, such as lead-based metal halide perovskite materials and cadmium-based quantum dots. Lead halide perovskite materials, in particular, possess excellent optoelectronic properties, including near-uniform photoluminescence quantum efficiency (PLQY), narrow emission peak linewidth, broad excitation band, and tunable emission wavelength, making them a promising next-generation optoelectronic material. However, the instability and toxicity of lead halide perovskite materials significantly hinder their commercial application.
[0003] Divalent manganese-based metal halides are ideal alternatives to lead halide perovskite materials due to their wide availability, low cost, and environmental friendliness. Because of their unique dd transitions, the emission wavelength can be tunable by changing the crystal field strength. When Mn... 2+ When Mn forms a tetracoordinate with halogens, it exhibits narrow-band green light emission due to its low crystal field strength; 2+ When Mn forms a five-coordinate system with halogens, the crystal field intensity increases, resulting in yellow light emission; 2+When forming a six-coordinate structure with halogens, it exhibits higher crystal field intensity and red light emission. The tunable emission wavelength gives divalent manganese-based metal halides different application scenarios. Among them, tetra-coordinated manganese-based metal halides have narrow-band green light emission and high photoluminescence quantum efficiency, and the white light devices constructed have a wide color gamut, thus showing broad application prospects in backlight displays. However, the commercialization of divalent manganese-based metal halides still faces two major challenges: (1) High-performance manganese-based metal halide single crystals still face harsh preparation conditions, involving the use of large amounts of organic solvents or concentrated acids, while polycrystalline manganese-based metal halide powders have poor fluorescence performance; (2) The stability of different types of red / green emitters varies greatly, resulting in unstable color performance of LED devices. Therefore, developing simple, green, and large-scale methods to synthesize efficient divalent manganese-based metal halide phosphors with tunable emission wavelengths, and constructing efficient and wide-gamut white LED devices, remains an urgent problem to be solved. Summary of the Invention
[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing highly efficient luminescent and wavelength-tunable divalent manganese-based metal halide materials, using tetramethylammonium halide and manganese halide as raw materials, and preparing [(CH3)4N] via a mechanochemical method. y MnX y+2 Manganese-based metal halide phosphors. Another object of the present invention is to provide applications of the above-mentioned divalent manganese-based metal halide materials.
[0005] The objective of this invention is achieved through the following technical solution:
[0006] This invention provides a method for preparing a highly efficient divalent manganese-based metal halide material with tunable light emission and emission wavelengths, comprising the following steps:
[0007] (1) Add tetramethylammonium halide and manganese halide into a ball mill jar according to a molar ratio of tetramethylammonium:manganese = 0.4 to 3:1, and ball mill on a vibrating ball mill for 2 to 180 minutes according to a ball:material ratio of 5 to 25:1 to obtain the ball milled product;
[0008] (2) The ball-milled product is washed with an organic solvent, and the precipitate is collected by filtration or centrifugation and then dried at 40–70°C for 15–60 min to obtain [(CH3)4N]. y MnX y+2 Manganese-based metal halide phosphors, wherein (CH3)4N + It is a tetramethylammonium cation, X is Cl, Br or I, and y = 1 or 2.
[0009] Further, the tetramethylammonium halide of the present invention is one or a combination of tetramethylammonium chloride, tetramethylammonium bromide, or tetramethylammonium iodide, and the manganese halide is one or a combination of manganese chloride, manganese chloride tetrahydrate, manganese bromide, manganese bromide tetrahydrate, and manganese iodide. The organic solvent is one or a combination of anhydrous ethanol, isopropanol, and n-hexane, and its amount is such that the mass ratio of ball-milled product to organic solvent is 1:10-50.
[0010] In the above scheme, the [(CH3)4N] described in this invention y MnX y+2 The emission wavelength of manganese-based metal halide phosphors is tunable in the range of 514–628 nm. Among them, [(CH3)4N]2MnX4 manganese-based metal halide phosphor is a green emitting material with an emission wavelength tunable in the range of 514–534 nm; [(CH3)4N]MnX3 manganese-based metal halide phosphor is a red emitting material with an emission wavelength tunable in the range of 619–628 nm.
[0011] Another objective of this invention is achieved through the following technical solution:
[0012] The product prepared using the above-described method for producing highly efficient and tunable-emission divalent manganese-based metal halide materials is applied to white LED devices. The material obtained by mixing the [(CH3)4N]MnX3 manganese-based metal halide phosphor with [(CH3)4N]2MnX4 manganese-based metal halide phosphor is mixed with silicone, then coated onto an LED chip. After curing, a white light-emitting diode device with a device efficiency of 60.10–98.06 lm / W and a color gamut coverage of 98–102% of the NTSC (National Television System Committee) standard (CIE1931) is obtained. Preferably, the material is mixed at a mass ratio of [(CH3)4N]MnX3 manganese-based metal halide phosphor : [(CH3)4N]2MnX4 manganese-based metal halide phosphor = 0.4–4 : 1.
[0013] The present invention has the following beneficial effects:
[0014] (1) This invention utilizes the energy of high-speed collisions during ball milling. Tetramethylammonium halide and manganese halide particles are pulverized into small pieces while undergoing continuous mechanical interactions (including transient impacts and shearing), resulting in a high density of reaction sites on the surface. These exposed active sites are beneficial for triggering and accelerating chemical reactions, thereby synthesizing manganese-based metal halide phosphors. Furthermore, by changing the raw material ratio, the emission wavelength of the manganese-based metal halide phosphor can be tuned between 514 and 628 nm. The green light emission originates from the island-like [MnX4] tetrahedrons of [(CH3)4N]2MnX4. The PLQY of the [(CH3)4N]2MnX4 phosphor can reach 21-98%, with a peak position of 514-534 nm and an emission peak linewidth of 44-50 nm. The red light emission originates from the chain-like [MnX6] octahedrons of [(CH3)4N]MnX3. The PLQY of the [(CH3)4N]MnX3 phosphor can reach 40-51%, with a peak position of 619-628 nm and an emission peak linewidth of 75-80 nm.
[0015] (2) When the green light emitting material [(CH3)4N]2MnX4 phosphor and the red light emitting material [(CH3)4N]MnX3 phosphor of the present invention are applied to white LEDs, the efficiency of the resulting device can reach 60.10 to 98.06 lm / W, and the color gamut covers 98 to 102% of the NTSC standard, which belongs to the high-efficiency wide color gamut display.
[0016] (3) The preparation method of the present invention is simple, green, low cost, good repeatability and short production cycle, which is conducive to realizing large-scale industrial production. Attached Figure Description
[0017] The present invention will now be described in further detail with reference to the embodiments and accompanying drawings:
[0018] Figure 1 This is the emission spectrum of the manganese-based metal halide material prepared in Example 1 of this invention;
[0019] Figure 2 This is the XRD pattern of the manganese-based metal halide material prepared in Example 1 of this invention;
[0020] Figure 3 This is the crystal structure of the manganese-based metal halide material prepared in Example 2 of the present invention;
[0021] Figure 4 This is the crystal structure of the manganese-based metal halide material prepared in Example 4 of the present invention;
[0022] Figure 5 The manganese-based metal halide material prepared in Example 7 of this invention is applied to the electroluminescence spectrum, color coordinates, and color gamut of white LED devices. Detailed Implementation
[0023] Example 1:
[0024] This embodiment describes a method for preparing a highly efficient luminescent and wavelength-tunable divalent manganese-based metal halide material, the steps of which are as follows:
[0025] (1) Tetramethylammonium chloride and manganese chloride tetrahydrate were added to a ball mill jar according to a molar ratio of tetramethylammonium:manganese = 0.4 to 2.75:1. The mixture was then ball-milled for 120 minutes at a speed of 1200 rpm / min on a vibrating ball mill according to a ball ratio (zirconia ball or agate ball):material = 10:1 to obtain the ball-milled product.
[0026] (2) Anhydrous ethanol was added to the above ball-milled product for washing, with a mass ratio of ball-milled product to anhydrous ethanol of 1:10. After centrifugation at 1000 rpm for 5 min, the precipitate was collected and dried in a vacuum drying oven at 40°C for 30 min to obtain the product shown in Table 1. Figure 1 Manganese-based metal chloride phosphors with different emission wavelengths are shown.
[0027] Table 1. Raw material ratios and phosphor emission wavelengths in Example 1
[0028]
[0029] like Figure 1 As shown, the [(CH3)4N] prepared in this embodiment y MnCl y+2 The emission wavelength of the phosphors is tunable in the range of 514–628 nm. Among them, [(CH3)4N]2MnCl4 phosphor is a green emitting material with an emission wavelength tunable in the range of 514–523 nm; [(CH3)4N]MnCl3 phosphor is a red emitting material with an emission wavelength tunable in the range of 619–628 nm.
[0030] like Figure 2 As shown, the [(CH3)4N] prepared in this embodiment y MnCl y+2 The phosphor synthesized by the following methods is as follows: when the molar ratio of tetramethylammonium to manganese is 0.4–0.8:1, the phosphor is [(CH3)4N]MnCl3 phase; when the molar ratio of tetramethylammonium to manganese is 1.0–1.5:1, the phosphor synthesized by the following methods is [(CH3)4N]MnCl3 phase (emission wavelength 619–522 nm) and [(CH3)4N]2MnCl4 phase (emission wavelength 514–520 nm); when the molar ratio of tetramethylammonium to manganese is 1.75–2.75:1, the phosphor synthesized by the following method is [(CH3)4N]2MnCl4 phase.
[0031] Example 2:
[0032] This embodiment describes a method for preparing a highly efficient luminescent and wavelength-tunable divalent manganese-based metal halide material, the steps of which are as follows:
[0033] (1) Tetramethylammonium chloride and manganese chloride tetrahydrate were added to a ball mill jar according to a molar ratio of tetramethylammonium:manganese = 0.8:1. The mixture was then ball-milled for 30 minutes at a speed of 1200 rpm / min on a vibrating ball mill according to a ball (zirconia ball or agate ball):material = 10:1 to obtain the ball milling product.
[0034] (2) Anhydrous ethanol was added to the ball milling product for washing. The mass ratio of ball milling product to anhydrous ethanol was 1:20. After centrifugation at 1000 rpm for 5 min, the precipitate was collected and dried in a vacuum drying oven at 50°C for 20 min to obtain red light emitting [(CH3)4N]MnCl3 manganese-based metal chloride phosphor with an emission wavelength of 628 nm and a photoluminescence efficiency of 51%.
[0035] Figure 3 In the crystal structure shown, Mn atoms form [MnX6] with surrounding halogen atoms. 4- Octahedrons (light-emitting centers) are linked in a coplanar manner, wherein the chain-like octahedrons are [(CH3)4N]. + Separate.
[0036] Example 3:
[0037] This embodiment describes a method for preparing a highly efficient luminescent and wavelength-tunable divalent manganese-based metal halide material, the steps of which are as follows:
[0038] (1) Tetramethylammonium chloride and manganese chloride were added to a ball mill jar according to a molar ratio of tetramethylammonium:manganese = 0.8:1. The mixture was then ball-milled for 120 min at a speed of 1200 rpm / min according to a ball (zirconia ball or agate ball):material = 15:1 to obtain the ball-milled product.
[0039] (2) Anhydrous ethanol was added to the ball milling product for washing. The mass ratio of ball milling product to anhydrous ethanol was 1:20. After centrifugation at 1000 rpm for 5 min, the precipitate was collected and dried in a vacuum drying oven at 60°C for 20 min to obtain red light emitting [(CH3)4N]MnCl3 manganese-based metal chloride phosphor with an emission wavelength of 625 nm.
[0040] Example 4:
[0041] This embodiment describes a method for preparing a highly efficient luminescent and wavelength-tunable divalent manganese-based metal halide material, the steps of which are as follows:
[0042] (1) Tetramethylammonium bromide and manganese bromide tetrahydrate were added to a ball mill jar according to a molar ratio of tetramethylammonium:manganese = 2.25:1. The mixture was then ball-milled for 150 min at a speed of 1200 rpm / min according to a ball (zirconia ball or agate ball):material = 20:1 to obtain the ball-milled product.
[0043] (2) Anhydrous ethanol was added to the ball milling product for washing. The mass ratio of ball milling product to anhydrous ethanol was 1:30. After centrifugation at 1000 rpm for 5 min, the precipitate was collected and dried in a vacuum drying oven at 60°C for 10 min to obtain green light emitting [(CH3)4N]2MnBr4 manganese-based metal bromide phosphor with an emission wavelength of 521 nm and a photoluminescence efficiency of 98%.
[0044] Figure 4 In the crystal structure shown, Mn atoms form [MnX4] with surrounding halogen atoms. 2- The tetrahedron (luminescent center) is isolated, and the tetrahedron is surrounded by [(CH3)4N]. + Separate.
[0045] Example 5:
[0046] This embodiment describes a method for preparing a highly efficient luminescent and wavelength-tunable divalent manganese-based metal halide material, the steps of which are as follows:
[0047] (1) Tetramethylammonium iodide and manganese bromide tetrahydrate were added to a ball mill jar according to a molar ratio of tetramethylammonium:manganese = 2:1. The mixture was then ball-milled for 150 min at a speed of 1200 rpm / min according to a ball (zirconia ball or agate ball):material = 20:1 to obtain the ball milling product.
[0048] (2) Isopropanol was added to the ball milling product for washing. The mass ratio of ball milling product to isopropanol was 1:30. After centrifugation at 1000 rpm for 5 min, the precipitate was collected and dried in a vacuum drying oven at 40°C for 30 min to obtain green light emitting [(CH3)4N]2MnBr2I2 manganese-based metal bromide iodide phosphor with an emission wavelength of 534 nm.
[0049] Example 6:
[0050] This embodiment describes a method for preparing a highly efficient luminescent and wavelength-tunable divalent manganese-based metal halide material, the steps of which are as follows:
[0051] (1) Tetramethylammonium bromide and manganese bromide were added to a ball mill jar according to a molar ratio of tetramethylammonium:manganese = 2.5:1. The mixture was then ball-milled for 150 min at a speed of 1200 rpm / min according to a ball (zirconia ball or agate ball):material = 10:1 to obtain the ball-milled product.
[0052] (2) Isopropanol was added to the ball milling product for washing. The mass ratio of ball milling product to isopropanol was 1:20. After centrifugation at 1000 rpm for 5 min, the precipitate was collected and dried in a vacuum drying oven at 40°C for 30 min to obtain green light emitting [(CH3)4N]2MnBr4 manganese-based metal bromide phosphor with an emission wavelength of 520 nm.
[0053] Embodiment seven:
[0054] The [(CH3)4N]MnCl3 manganese-based metal chloride phosphor prepared in Example 2 of this invention was mixed with the [(CH3)4N]2MnBr4 manganese-based metal bromide phosphor prepared in Example 4 (at a mass ratio of phosphor from Example 2 to phosphor from Example 4 = 2:1). The resulting material was then mixed with silica gel (at a mass ratio of silica gel to material = 1:1) and coated onto a 460nm blue LED chip. After curing, a white LED device was obtained. Figure 5 As shown, the device has an efficiency of up to 98.06 lm / W, color coordinates of (0.3309, 0.3457), and a color gamut covering 100.3% of the NTSC standard. It is a high-efficiency wide color gamut display and can be used as a backlight display unit.
Claims
1. A method for preparing a highly efficient luminescent and wavelength-tunable divalent manganese-based metal halide material, characterized in that... Includes the following steps: (1) Add tetramethylammonium halide and manganese halide into a ball mill jar according to a molar ratio of tetramethylammonium:manganese = 0.4 to 3:1, and ball mill on a vibrating ball mill for 2 to 180 min according to a ball:material ratio of 5 to 25:1 to obtain the ball milled product; (2) The ball-milled product is washed with organic solvent at a mass ratio of 1:10-50, wherein the organic solvent is one or a combination of anhydrous ethanol, isopropanol, and n-hexane. After filtration or centrifugation to collect the precipitate, it is dried at 40-70°C for 15-60 min to obtain [(CH3)4N] with an emission wavelength tunable in the range of 514-628 nm. y MnX y+2 Manganese-based metal halide phosphors, wherein (CH3)4N + The phosphor is a tetramethylammonium cation, where X is Cl, Br, or I, and y = 1 or 2; [(CH3)4N]2MnX4 manganese-based metal halide phosphor is a green emitting material, with green light emission originating from the island-like [MnX4] tetrahedra of [(CH3)4N]2MnX4. The emission wavelength of [(CH3)4N]2MnX4 phosphor is tunable in the range of 514–534 nm, with a PLQY of 21–98% and an emission peak linewidth of 44–50 nm; [(CH3)4N]MnX3 manganese-based metal halide phosphor is a red emitting material, with red light emission originating from the chain-like [MnX6] octahedrons of [(CH3)4N]MnX3. The emission wavelength of [(CH3)4N]MnX3 phosphor is tunable in the range of 619–628 nm, with a PLQY of 40–51% and an emission peak linewidth of 75–80 nm.
2. The method for preparing the highly efficient luminescent and wavelength-tunable divalent manganese-based metal halide material according to claim 1, characterized in that: The tetramethylammonium halide is one or a combination of tetramethylammonium chloride, tetramethylammonium bromide, or tetramethylammonium iodide, and the manganese halide is one or a combination of manganese chloride, manganese chloride tetrahydrate, manganese bromide, manganese bromide tetrahydrate, and manganese iodide.
3. The method for preparing highly efficient luminescent and wavelength-tunable divalent manganese-based metal halide materials according to claim 1, characterized in that: The [(CH3)4N] y MnX y+2 Manganese-based metal halide phosphors are used in white light-emitting diode (LED) devices. The material obtained by mixing [(CH3)4N]MnX3 manganese-based metal halide phosphor and [(CH3)4N]2MnX4 manganese-based metal halide phosphor is mixed with silicone, then coated onto an LED chip. After curing, a white light-emitting diode device with a device efficiency of 60.10 to 98.06 lm / W and a color gamut covering 98 to 102% of the NTSC standard is obtained.
4. The method for preparing the highly efficient luminescent and wavelength-tunable divalent manganese-based metal halide material according to claim 3, characterized in that: The materials are mixed at a mass ratio of [(CH3)4N]MnX3 manganese-based metal halide phosphor : [(CH3)4N]2MnX4 manganese-based metal halide phosphor = 0.4 to 4:1.