Indium-based hybrid metal halide crystal and its preparation method and application

Abstract

The present application discloses an indium-based hybrid metal halide crystal and its preparation method and application, belonging to the field of fluorescent materials. The chemical formula of the indium-based hybrid metal halide crystal is [Ammim][InCl4L]; wherein Ammim is an organic cation, InCl4L is a halide anion, and L is an organic ligand; the organic cation is 1-allyl-2,3-dimethylimidazolium ion; and the organic ligand is 4,4'-dimethyl-2,2'-bipyridine. The indium-based hybrid metal halide crystal of the present application is a zero-dimensional hybrid metal halide that can convert ultraviolet light into high-intensity visible light. The preparation process is simple, the raw materials are environmentally friendly and inexpensive and readily available, the resulting product is high in purity, has excellent fluorescent properties, good stability, and is extremely easy to process, making it an excellent choice as a single-component white light emitting material.

Description

Technical Field

[0001] The present application relates to an indium-based hybrid metal halide crystal and a preparation method and application thereof, belonging to the field of fluorescent materials. Background Art

[0002] Semiconductor lighting, referring to solid-state lighting using semiconductor light-emitting diodes (LEDs) as light sources, is an emerging technology. Its numerous advantages over traditional electric lighting, such as energy saving, environmental friendliness, long lifespan, compact size, fast response, and impact resistance, have attracted numerous renowned companies, both domestically and internationally, to invest heavily in research and product development. Nichia Corporation of Japan pioneered the development of high-brightness blue LEDs based on GaN, enabling LED manufacturers to produce all three primary colors (red, green, and blue), thus enabling the production of 16.7 million colors. Philips of the Netherlands has also made significant efforts in the application of LEDs in the home. Other companies include Osram-Photonics of Germany and Hewlett-Packard of the United States.

[0003] Among various LED products, white light LEDs are considered the next generation of light sources due to their high efficiency, brightness, and even potential to simulate natural sunlight. Three main methods for manufacturing white light LEDs exist. The first involves combining red, green, and blue chips and simultaneously stimulating them to produce white electroluminescence. The second involves using a blue chip to excite a yellow phosphor, achieving white light emission. The third involves using a UV chip to simultaneously excite red, green, and blue phosphors, producing white light with a high color rendering ratio across the entire visible light range. However, these methods have drawbacks. For example, white light LEDs constructed from chip combinations are costly and pose significant heat dissipation challenges. White light LEDs produced using blue chips stimulating yellow phosphors have low color rendering indexes. White light LEDs made using commonly used three-color phosphors experience energy transfer and different decay rates between the phosphors, which results in shifts in the emission spectrum during illumination, leading to low luminous efficiency. Therefore, the development of single-component white light luminescent materials is of great practical significance for the fabrication of new white light LEDs.

[0004] Inorganic-organic hybrid metal halides are considered promising candidates for single-component white-light emitting materials due to their tunable band gaps, broad emission, high absorption coefficients, and high quantum yields. Modifying the anionic moiety with ligands is an effective means of manipulating the luminescence properties of inorganic-organic hybrid metal halides. However, the development of ligand-modified ionic inorganic-organic hybrid metal halides as single-component white-light emitting materials has yet to be reported. Summary of the Invention

[0005] According to one aspect of the present application, an indium-based hybrid metal halide crystal is provided, which is a new single-component white light emitting material with photoluminescence properties, overcoming the problems in the three main white light LED manufacturing methods in the aforementioned prior art.

[0006] This application adopts the following technical solutions:

[0007] An indium-based hybrid metal halide crystal, wherein the chemical formula of the indium-based hybrid metal halide crystal is [Ammim][InCl4L];

[0008] Among them, Ammim is an organic cation, InCl4L is a halide anion, and L is an organic ligand;

[0009] The organic cation is 1-allyl-2,3-dimethylimidazolium ion;

[0010] The organic ligand is 4,4'-dimethyl-2,2'-bipyridine.

[0011] Optionally, the structural formula of the 4,4'-dimethyl-2,2'-bipyridine is:

[0012]

[0013] Optionally, in the halide anion, In 3+ With 4 Cl - And the N coordination on the two organic ligands forms an octahedral configuration.

[0014] Preferably, the indium-based hybrid metal halide crystal has a zero-dimensional structure.

[0015] Optionally, the zero-dimensional structure is formed by forming an octahedral configuration in the halide anion and then being separated by organic cations.

[0016] Optionally, the indium-based hybrid metal halide crystal is an ionic inorganic-organic hybrid metal halide.

[0017] Optionally, the indium-based hybrid metal halide crystal belongs to the monoclinic system and has a space group of P21 / c.

[0018] Optionally, the unit cell parameters of the indium-based hybrid metal halide crystal are β=109.006(2)°, Z=4.

[0019] Optionally, the indium-based hybrid metal halide crystal exhibits white light emission under light excitation with a wavelength of 375 nm.

[0020] Optionally, the emission peak-to-peak value range of the white light is 470-480 nm, and the wavelength range of the emission peak half-peak value of the white light is 400-800 nm.

[0021] Optionally, the indium-based hybrid metal halide crystal can convert ultraviolet light into visible light through its photoluminescence property.

[0022] Optionally, the indium-based hybrid metal halide crystal is used as a single-component white light phosphor, and its color rendering index is ≥93.2.

[0023] According to another aspect of the present application, a method for preparing the above-mentioned indium-based hybrid metal halide crystal is provided, characterized in that it comprises the following steps:

[0024] A mixture containing 1-allyl-2,3-dimethylimidazolium chloride, InCl3, 4,4'-dimethyl-2,2'-bipyridine and a non-aqueous solvent is heated in a sealed container for reaction to obtain the indium-based hybrid metal halide crystal.

[0025] Optionally, the conditions for the heating reaction include: a reaction temperature of 120 to 160° C., and a reaction time of 2 to 6 days.

[0026] Optionally, the temperature of the heating reaction is selected from any value among 120°C, 130°C, 140°C, 150°C, 160°C, or any range therebetween.

[0027] Optionally, the heating reaction time is selected from any value among 2 days, 3 days, 4 days, 5 days, 6 days, or any range between them.

[0028] Optionally, the molar ratio of 1-allyl-2,3-dimethylimidazolium chloride, InCl3, and 4,4'-dimethyl-2,2'-bipyridine in the mixture is 1:(0.8-1.2):(0.8-1.2).

[0029] Optionally, the molar ratio of 1-allyl-2,3-dimethylimidazolium chloride, InCl3, and 4,4'-dimethyl-2,2'-bipyridine in the mixture is 1:1:1.

[0030] Optionally, the solid-liquid ratio of 1-allyl-2,3-dimethylimidazolium chloride to the non-aqueous solvent is 1 mmol:2-6 mL;

[0031] Optionally, the non-aqueous solvent is selected from acetonitrile.

[0032] Optionally, after the heating reaction, the method further comprises cooling to room temperature and washing with acetonitrile to remove impurities.

[0033] Optionally, the raw materials used to prepare the mixture include 1-allyl-2,3-dimethylimidazolium chloride, InCl3·4H2O and 4,4'-dimethyl-2,2'-bipyridine, all of which are solid.

[0034] Optionally, among the raw materials used to prepare the mixture, InCl 3 ·4H 2 O and 4,4'-dimethyl-2,2'-bipyridine are powders.

[0035] According to another aspect of the present application, a fluorescent material is further provided, which includes at least one of the indium-based hybrid metal halide crystals described in any one of the above items or the indium-based hybrid metal halide crystals prepared according to the above preparation method.

[0036] According to another aspect of the present application, a fluorescent lamp is provided, wherein the fluorescent material includes at least one of the indium-based hybrid metal halide crystals described above or the indium-based hybrid metal halide crystals prepared according to the above preparation method.

[0037] The fluorescent material includes at least one of the indium-based hybrid metal halide crystals described above or the indium-based hybrid metal halide crystals prepared according to the above preparation method.

[0038] The beneficial effects of this application include:

[0039] The indium-based hybrid metal halide crystals provided herein are a novel zero-dimensional indium-based hybrid metal halide fluorescent material, capable of converting ultraviolet light into high-intensity visible light and acting as a single-component white-light luminescent material. The indium-based hybrid metal halide crystals provided herein have a simple preparation process, using environmentally friendly, inexpensive, and readily available raw materials. The resulting product is high in purity, exhibits excellent fluorescence properties, is stable, and is easily processed, making it an excellent choice for single-component white-light luminescent materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 Schematic diagram of the crystal structure of the indium-based hybrid metal halide crystal sample in Example 1 of the present application.

[0041] Figure 2 These are the excitation and emission spectra of the indium-based hybrid metal halide crystal sample in Test Example 2 of this application.

[0042] Figure 3 In the test example 3 of this application, the indium-based hybrid metal halide crystal sample is coated on the InGaN ultraviolet chip (λ em =380nm).

[0043] Figure 4 This is a photo of the WLED device prepared in Test Example 3 of this application. DETAILED DESCRIPTION

[0044] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0045] Unless otherwise specified, the raw materials in the examples of this application were purchased through commercial channels.

[0046] Unless otherwise specified, conventional methods were used for testing, and instrument settings were those recommended by the manufacturer.

[0047] Example 1

[0048] 1 mmol InCl3·4H2O powder, 1 mmol 4,4'-dimethyl-2,2'-bipyridine powder, and 1 mmol 1-allyl-2,3-dimethylimidazolium chloride solid were mixed with 4 mL CH3CN, placed in a polytetrafluoroethylene liner, sealed in a corresponding stainless steel reactor, and placed in an oven and heated to 140°C. After 4 days, the reaction mixture was removed, cooled, and washed three times with CH3CN at room temperature. The reaction mixture was dried to obtain an indium-based hybrid metal halide crystal sample with the chemical formula [Ammim][InCl4L].

[0049] Test Example 1

[0050] The indium-based hybrid metal halide crystal sample obtained in Example 1 was tested by X-ray single crystal diffraction, and the sample structure was analyzed by Shelx 2018. The crystal structure of the sample was obtained by X-ray single crystal diffraction. The results showed that the sample 1# crystal belonged to the P21 / c space group, and its unit cell parameters were: β=109.006(2)°, Z=4. The structural diagram is as follows Figure 1 As shown, the large pure black ball represents In atom, the dark gray ball connected to it represents Cl atom, the gray-black balls on the six-membered ring and the five-membered ring represent N atoms, the gray-white balls represent C atoms, and the white balls represent H atoms.

[0051] Test Example 2

[0052] The excitation and emission spectra of the indium-based hybrid metal halide crystal sample obtained in Example 1 are as follows: Figure 2 As shown, it can be seen that the sample can emit 470nm white light under the excitation of 375nm ultraviolet light, and its solid-state quantum yield is measured to be 16.70% and the fluorescence lifetime is 3.037ns.

[0053] Test Example 3

[0054] The coating of the indium-based hybrid metal halide crystal sample obtained in Example 1 was placed on an InGaN ultraviolet chip (λem =380nm) and its emission spectrum is as follows Figure 3 As shown in the figure, under a current of 100mA, the WLED device prepared by the sample shows white light emission with color coordinates of (0.3269, 0.3461) and a color temperature of 5744K, and its color rendering index is measured to be 93.2. Figure 4 shown.

[0055] The above descriptions are merely a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application discloses the preferred embodiments as above, they are not intended to limit the present application. Any technical personnel familiar with the present profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. An indium-based hybrid metal halide crystal, characterized in that: The chemical formula of the indium-based hybrid metal halide crystal is [Ammim][InCl4L]; Among them, Ammim is an organic cation, InCl4L is a halide anion, and L is an organic ligand; The organic cation is 1-allyl-2,3-dimethylimidazolium ion; The organic ligand is 4,4'-dimethyl-2,2'-bipyridine; The indium-based hybrid metal halide crystal belongs to the monoclinic system and has a space group of P21 / c; The unit cell parameters of the indium-based hybrid metal halide crystal are β=109.006(2)°, Z=4.

2. The indium-based hybrid metal halide crystal according to claim 1, characterized in that: Among the halide anions, In 3+ With 4 Cl - And the N coordination on the two organic ligands forms an octahedral configuration.

3. The indium-based hybrid metal halide crystal according to claim 1, characterized in that: The indium-based hybrid metal halide crystal has a zero-dimensional structure.

4. The indium-based hybrid metal halide crystal according to claim 1, characterized in that: The indium-based hybrid metal halide crystal emits white light under the excitation of light with a wavelength of 375 nm.

5. The indium-based hybrid metal halide crystal according to claim 4, characterized in that: The emission peak value range of the white light is 470-480 nm.

6. The method for preparing the indium-based hybrid metal halide crystal according to any one of claims 1 to 5, characterized in that: The steps include: A mixture containing 1-allyl-2,3-dimethylimidazolium chloride, InCl3, 4,4'-dimethyl-2,2'-bipyridine, and a non-aqueous solvent is heated in a sealed container for reaction to obtain the indium-based hybrid metal halide crystal; The non-aqueous solvent is selected from acetonitrile.

7. The preparation method according to claim 6, characterized in that The conditions for the heating reaction include: a reaction temperature of 120 to 160° C. and a reaction time of 2 to 6 days.

8. The preparation method according to claim 6, characterized in that The molar ratio of 1-allyl-2,3-dimethylimidazolium chloride, InCl3, and 4,4'-dimethyl-2,2'-bipyridine in the mixture is 1:(0.8-1.2):(0.8-1.2); The solid-liquid ratio of 1-allyl-2,3-dimethylimidazolium chloride to the non-aqueous solvent is 1 mmol:2-6 mL.

9. A fluorescent material, characterized in that The fluorescent material comprises at least one of the indium-based hybrid metal halide crystals according to any one of claims 1 to 5 or the indium-based hybrid metal halide crystals prepared according to the preparation method according to any one of claims 6 to 8.

10. A fluorescent lamp, characterized in that: The fluorescent lamp comprises at least one of the indium-based hybrid metal halide crystal according to any one of claims 1 to 5 or the indium-based hybrid metal halide crystal prepared according to the preparation method according to any one of claims 6 to 8.

11. A light emitting diode, characterized in that: The light-emitting diode comprises at least one of the indium-based hybrid metal halide crystal according to any one of claims 1 to 5 or the indium-based hybrid metal halide crystal prepared by the preparation method according to any one of claims 6 to 8.

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