Copper-based organic-inorganic hybrid photoluminescent material and its preparation method and application

Abstract

The present invention relates to a copper-based organic-inorganic hybrid photoluminescent material and its preparation method and application. The chemical formula of the luminescent material is as follows: (C4H 10 NO)4Cu2Br y I 6‑y nH2O, C4H 10 NO is a morpholinium ion, y=0-6, n=0-1. 10 NO)4Cu2I6·H2O crystal luminescent material has unique yellow-green and red dual-color tunable luminescence characteristics; the quantum yield of yellow-green light is high, reaching 128.70%, and the quantum yield of pure red light emission can reach 75.76%. It is environmentally friendly and highly stable.

Description

Technical Field

[0001] The present invention belongs to the field of photoluminescent materials and optoelectronic technology, and in particular relates to a copper-based organic-inorganic hybrid photoluminescent material and a preparation method and application thereof. Background Art

[0002] With the advent of the information society, information security, as a crucial component of safeguarding political, military, scientific, economic, and cultural security, has become a focus of international attention. As core technologies for ensuring information security, information encryption and anti-counterfeiting are attracting increasing research interest. A range of related technologies, including watermarking, laser holography, shape coding, and photoluminescence, have been developed. Photoluminescence information encryption and anti-counterfeiting, in particular, has become a leading option due to its advantages of low cost, ease of operation, fast response, and strong concealment. Inorganic photoluminescent materials often contain rare earth ions, while organic photoluminescent materials suffer from poor stability. Rare earth ion-doped luminescent materials are also commonly used, but their high price and processing costs limit their application. Organic-inorganic hybrid metal halides, with their diverse advantages, low cost, and tunable emission color, are of great significance in establishing high-level information security and encryption. At the same time, low-dimensional metal halides with high photoluminescence properties still have room for improvement in terms of low toxicity and environmental friendliness.

[0003] Among existing photoluminescent materials, copper-containing metal halides have become an important class of photoluminescent materials due to their low cost, low toxicity, abundant reserves, and excellent optical properties. Numerous patent documents have been published regarding this type of luminescent material. For example, CN113801144A discloses an X-ray-excited luminescent material and its preparation method. The material comprises a complex composed of cuprous iodide or cuprous bromide as a core and 3-picoline and triphenylphosphine as ligands. The complexes, namely, CuI(Pph3)2(3-pc) (blue luminescence with a wavelength range of 400-650 nm, a peak at 467 nm, and a quantum efficiency of 93.21%) and CuBr(Pph3)2(3-pc) (blue luminescence with a wavelength range of 400-650 nm, a peak at 500 nm, and a quantum efficiency of 88.99%), which emit strong fluorescence under X-ray or ultraviolet excitation. CN113292580A discloses the preparation and application of high-quantum-yield copper bromide hybrid crystals that emit blue light. The synthesized copper bromide hybrid crystal (BZ-TED) CuBr2(TPP)2H2O exhibits a half-width (FWHM) of approximately 75 nm, a peak emission wavelength of 430 nm, and a quantum yield of 81%. It can be used to prepare solid-state light-emitting devices. CN112898321A discloses a luminescent copper-based organic-inorganic hybrid material, its preparation method, and its application. The chemical formula is Cu2Br4L2, where L represents 1-(2-chloroethyl)-1,4-diazacyclo[2.2.2]-octane or 1-(2-bromoethyl)-1,4-diazacyclo[2.2.2]-octane. This material emits green light with a quantum yield of 11.5%. However, most copper-containing luminescent materials, such as copper-containing metal halides, currently have limited luminescence in the pure red wavelength range, and their emission colors are relatively monochromatic, with few examples demonstrating tunable multicolor luminescence. In addition, under normal circumstances, the value of photoluminescence quantum yield (PLQY) is always less than 1.However, there are reports of PLQY greater than 1 in quantum dots and nanocrystal materials (see: [1] Arthur J. Nozik, Multiple exciton generation in semiconductor quantum dots, Chemical Physics Letters, 2018, 18, 3792-3799; [2] Tyler J. Milstein, Daniel M. Kroupa, Daniel R. Gamelin, Picosecond quantum cutting generates photoluminescence quantum yields over 100% in ytterbium-doped CsPbCl3 nanocrystals, Nano Letters, 2018, 18, 3792-3799; [3] Martinez, Marissa Sally, Multiple exciton generation for solar watersplitting and ligand exchange properties on Pbs quantum dots, University of Colorado at Boulder ProQuest Dissertations Publishing, 2021; [4] Aaron G. Midgett, Joseph M. Luther, J. T. Stewart, Daniel H. Smith, Lázaro A. Padilha, Victor I. Klimov, Arthur J. Nozik, Matthew C. Beard, Size and composition dependent multiple exciton generation efficiency in PbS, PbSe, and PbS. x Se 1–xalloyed quantum dots, Nano Letters, 2013, 13, 3078-3085), which is attributed to the existence of multi-exciton generation (MEG) in the luminescence process. Multi-exciton generation (MEG) refers to the simultaneous generation of two or more excitons for each high-energy photon absorbed in a semiconductor. When these excitons recombine, energy is released in the form of photons, resulting in the number of emitted photons being greater than the number of absorbed photons, that is, the PLQY being greater than 1. There are only two reports of PLQY greater than 1 in bulk materials, one of which is Mn 2+ Doped phenylammonium cadmium chloride (see: A. Jana, C. W. Myung, V. G. Seee and K. S. Kim, Upconversion and multiexciton generation inorganic Mn(II) complex boost the quantum yield to>100%, Mater. Chem. Front., 2022, 6, 3102-3114.), another example is [Me3NPh]2MnBr4 (see: S. Wang, S. Feng, R. Li, J. Jin, J. Wu, W. Zheng, Z. Xia, X. Chen, Q. Ling and Z. Lin, Multiexciton generation from a 2D organic-inorganic hybrid perovskite with nearly 200% quantum yield of red phosphorescence, Adv. Mater., 2023, 35, 2211992.). For these two cases, the PLQY greater than 1 is also attributed to multiexciton generation (Multiexciton Generation MEG). For copper-containing luminescent materials, materials with photoluminescence quantum yields close to 100%, especially greater than 100%, have not yet been reported. Summary of the Invention

[0004] To address the problems and shortcomings of existing technologies, particularly the scarcity of luminescent materials in the pure red wavelength range, the relatively single-color emission of existing copper-containing luminescent materials, the lack of tunable multicolor emission, and the lack of copper-containing luminescent materials with photoluminescence quantum yields approaching 100%, or particularly exceeding 100%, the present invention provides copper-based organic-inorganic hybrid photoluminescent materials, their preparation methods, and applications. The copper-based organic-inorganic hybrid luminescent materials provided by the present invention have high luminous efficiency, are tunable in both yellow-green and pure red light, and have a yellow-green quantum yield exceeding 100%.

[0005] Terminology Notes:

[0006] Photoluminescence quantum yield (PLQY): The PLQY of a compound or substance is defined as the ratio of the number of photons emitted to the number of photons absorbed. PLQY is an important indicator of a substance's ability to emit fluorescence. A higher PLQY value indicates a stronger fluorescence.

[0007] The technical solutions of the present invention are as follows:

[0008] Copper-based organic-inorganic hybrid photoluminescent material, the chemical formula of the luminescent material is as follows:

[0009] (C4H 10 NO)4Cu2Br y I 6-y nH2O, C4H 10 NO is a morpholinium ion, y=0-6, n=0-1.

[0010] According to the present invention, preferably, the luminescent material has at least one of the following chemical compositions:

[0011] (C4H 10 NO)4Cu2Br6、(C4H 10 NO)4Cu2I6·H2O.

[0012] According to the present invention, preferably, when the chemical formula of the luminescent material is (C4H 10 NO)4Cu2Br6, the chemical composition is C 16 H 40 Br6Cu2N4O4, relative molecular mass is 958.05, space group is P1, unit cell parameters are α=105.765(2)°, β=104.696(2)°, γ=101.258(2)°.

[0013] According to the present invention, preferably, when the chemical formula of the luminescent material is (C4H 10NO)4Cu2I6·H2O, the chemical composition is C 16 H 42 Cu2I6N4O5, relative molecular mass is 1259.01, space group is C2 / c, unit cell parameters are α=90°, β=98.518(2)°, γ=90°.

[0014] According to the present invention, preferably, when the chemical formula of the luminescent material is (C4H 10 NO)4Cu2Br6, under 313nm ultraviolet light irradiation, it exhibits yellow-green luminescence with a luminescence peak of 537nm, a luminescence range of 400-751nm, an excitation range corresponding to the peak of 225-385nm, a luminescence lifetime of 106.9μs, and a quantum yield of 96.16%.

[0015] According to the present invention, preferably, when the chemical formula of the luminescent material is (C4H 10 NO)4Cu2I6·H2O, under 317nm ultraviolet light irradiation, exhibits yellow-green luminescence with a peak of 547nm, a luminescence range of 410-800nm, and an excitation range corresponding to the peak of 265-372nm. The luminescence lifetime of the yellow-green light is 183.5μs, and the quantum yield is 128.70%;

[0016] Preferably, under irradiation of 380nm ultraviolet light, it exhibits pure red light with a peak value of 679nm, a light emission range of 485-840nm, an excitation range corresponding to the peak value of 340-525nm, a light emission lifetime of red light of 1.2μs, and a quantum yield of 75.76%.

[0017] According to the present invention, a method for preparing the above-mentioned copper-based organic-inorganic hybrid luminescent material is also provided, comprising the following steps:

[0018] Dissolve cuprous halide, hydrohalic acid, hypophosphorous acid and morpholine in an organic solvent, stir evenly, and then evaporate the solvent to crystallize to obtain the product.

[0019] According to the present invention, preferably, the cuprous halide is cuprous bromide and / or cuprous iodide;

[0020] Preferably, the hydrohalic acid is hydrobromic acid and / or hydroiodic acid.

[0021] According to the present invention, preferably, the molar ratio of morpholine to cuprous halide is (3.0-1.5):1; the molar ratio of cuprous halide to hydrohalic acid is 1:(1.0-4.0).

[0022] According to the present invention, the purpose of adding hypophosphorous acid is to prevent oxidation, that is, to act as a strong reducing agent to avoid the oxidation of cuprous ions (Cu+ ) is oxidized to copper ions (Cu 2+ ), to avoid oxidation of halogen ions to halogen elements; preferably, the molar ratio of hypophosphorous acid to cuprous halide is (1.0-3.0):1.

[0023] According to the present invention, preferably, the organic solvent is at least one organic solvent selected from the group consisting of ketones, alcohols, esters, ethers, hydrocarbons, and nitrile solvents; further preferably, acetone, ethanol, ethyl acetate, diethyl ether, cyclohexane, and / or acetonitrile.

[0024] According to the present invention, preferably, in order to accelerate the reaction, heating or not heating can be selected according to the melting and boiling points of the solvent, and the heating temperature is preferably 25-80°C.

[0025] According to the present invention, preferably, the stirring speed may be 200-2000 rpm, and the stirring time is 0.2-12 hours;

[0026] Preferably, the time for volatilizing the solvent is 3-60 days.

[0027] According to the present invention, a method for preparing a copper-based organic-inorganic hybrid photoluminescent material, in a preferred embodiment, comprises the following steps:

[0028] Dissolve cuprous bromide, hydrobromic acid, hypophosphorous acid and morpholine in acetone solvent and stir to obtain a clear solution. Place the clear solution in a fume hood and allow to stand at room temperature until (C4H 10 NO)4Cu2Br6 crystals are precipitated to obtain.

[0029] According to the present invention, another preferred embodiment of the method for preparing a copper-based organic-inorganic hybrid photoluminescent material comprises the following steps:

[0030] Dissolve cuprous iodide, hydroiodic acid, hypophosphorous acid and morpholine in acetone solution, heat and stir to obtain a clear solution, and place the clear solution in a fume hood at room temperature until (C4H 10 NO)4Cu2I6·H2O crystals are precipitated to obtain.

[0031] According to the present invention, there is also provided the use of the copper-based organic-inorganic hybrid luminescent material as a rare earth-free luminescent material, preferably in an LED.

[0032] According to the present invention, there is also provided an LED lamp comprising the copper-based organic-inorganic hybrid luminescent material.

[0033] According to the present invention, a preferred embodiment of the method for preparing the LED lamp includes the following steps:

[0034] Select (C4H 10 NO)4Cu2Br6 or (C4H10 NO)4Cu2I6·H2O single crystal is embedded in a UV 255nm pump LED chip to make an LED lamp.

[0035] According to the present invention, preferably, based on (C4H 10 The luminescence peak of the LED lamp prepared by NO)4Cu2Br6 is at 562nm;

[0036] Preferably, based on (C4H 10 The luminescence peaks of the LED lamps prepared by NO)4Cu2I6·H2O are at 544nm and 680nm respectively.

[0037] According to the present invention, further provided is the application of the above copper-based organic-inorganic hybrid photoluminescent material in the field of information encryption:

[0038] Preferably, (C4H 10 NO)4Cu2Br6 or / and (C4H 10 NO)4Cu2I6·H2O is ground into powder and used for information encryption based on Morse code.

[0039] Preferably, (C4H 10 NO)4Cu2Br6 or / and (C4H 10 NO)4Cu2I6·H2O are dissolved in organic solvents to form thin films, which are used for information encryption based on Morse code. Preferably, the organic solvent is at least one of ketones, alcohols, esters, ethers, hydrocarbons, and nitriles; more preferably, acetone, ethanol, ethyl acetate, diethyl ether, cyclohexane, and / or acetonitrile.

[0040] The beneficial effects of the present invention are as follows:

[0041] 1. (C4H 10 NO)4Cu2I6·H2O crystal luminescent material has unique yellow-green and red dual-color tunable luminescence characteristics; the quantum yield of yellow-green light is high, reaching 128.70%, and the quantum yield of pure red light emission can reach 75.76%. It is environmentally friendly and highly stable.

[0042] 2. (C4H 10 NO)4Cu2Br6 crystal luminescent material has a high quantum yield of up to 96.16%; it is environmentally friendly and highly stable.

[0043] 3. The present invention is based on (C4H 10 NO)4Cu2Br6 crystals and / or (C4H 10 The LED device prepared by NO)4Cu2I6·H2O crystal shows the same luminescence peak position at different voltages, indicating good luminescence stability.

[0044] 4. The preparation method of the copper-based organic-inorganic hybrid luminescent material of the present invention is simple to operate, easy to mass produce, and low in cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 is obtained in Example 1 of the present invention (C4H 10 NO)4Cu2Br6 crystal photos, as well as photos under UV light at 254nm and 365nm.

[0046] Figure 2 is obtained in Example 2 of the present invention (C4H 10 NO)4Cu2I6·H2O crystal photos, as well as photos under ultraviolet light at 254nm and 365nm.

[0047] Figure 3 In Test Example 1 of the present invention (C4H 10 NO)4Cu2Br6 crystal structure (a) structural unit, (b) structural stacking diagram, (c) comparison of polycrystalline powder X-ray diffraction pattern and single crystal X-ray diffraction data simulation diagram.

[0048] Figure 4 In Test Example 2 of the present invention (C4H 10 NO)4Cu2I6·H2O crystal structure (a) Structural unit, (b) Structural stacking diagram, (c) Comparison of polycrystalline powder X-ray diffraction pattern and single crystal X-ray diffraction data simulation diagram.

[0049] Figure 5 The UV absorption spectra of the copper halide crystal powder in Experimental Example 3 of the present invention are shown; substrate: barium sulfate. (a) and (b) represent (C4H 10 NO)4Cu2Br6 and (C4H 10 NO)4Cu2I6·H2O.

[0050] Figure 6 In Test Example 4 of the present invention (C4H 10 (a) Fluorescence spectrum, (b) fluorescence lifetime diagram and (c) quantum yield diagram of NO)4Cu2Br6 crystal.

[0051] Figure 7 In Test Example 5 of the present invention (C4H 10 (a) Fluorescence spectrum, (b) fluorescence lifetime diagram, and (c) quantum yield diagram of yellow-green light emission from NO)4Cu2I6·H2O crystal.

[0052] Figure 8 In Test Example 6 of the present invention (C4H 10(a) Fluorescence spectrum, (b) fluorescence lifetime diagram, and (c) quantum yield diagram of pure red luminescence of NO)4Cu2I6·H2O crystal.

[0053] Figure 9 It is based on (C4H in Example 6 of the present invention 10 (a) Photograph, (b) photoluminescence spectrum and (c) CIE color diagram of LED prepared from NO)4Cu2Br6 crystal.

[0054] Figure 10 It is based on (C4H in Example 7 of the present invention 10 (a) Photograph, (b) photoluminescence spectrum, and (c) CIE color diagram of LED fabricated from NO)4Cu2I6·H2O crystal.

[0055] Figure 11 This is the model representing 26 letters designed based on Morse code in Example 8 of the present invention (a), and the white letters need to be filled (C4H 10 NO)4Cu2Br6, brown needs to be filled (C4H 10 NO)4Cu2I6·H2O; the designed model simulates the filling of (C4H 10 NO)4Cu2Br6 or (C4H 10 Figure 3. Simulated luminescence of the NO)4Cu2I6·H2O sample under UV light (b) 254nm (the information transmitted is 13 letters, which are "BCFHJLPQVWXYZ") and (c) 365nm (the information transmitted is 13 letters, which are "DRUSOENKATIMG").

[0056] Figure 12 In Experimental Example 7 of the present invention, (a) is a design model based on Morse code that needs to transmit information, and white needs to be filled (C4H 10 NO)4Cu2Br6, brown needs to be filled (C4H 10 NO)4Cu2I6·H2O; the designed model simulates the filling of (C4H 10 NO)4Cu2Br6 or (C4H 10 NO)4Cu2I6·H2O sample under UV light (b) 254nm (transmitted information is "QF") and (c) 365nm (transmitted information is "NU"); (d) Model representing "QFNU" designed based on Morse code; (e) Model representing "QFNU" filled with (C4H 10 NO)4Cu2Br6 and (C4H 10 NO)4Cu2I6·H2O powder after filling (C4H 10NO)4Cu2Br6 and (C4H 10 Actual photos of NO)4Cu2I6·H2O powder after irradiation with ultraviolet lamp (f) wavelength 254nm (the information transmitted is "QF") and (g) wavelength 365nm (the information transmitted is "NU"). DETAILED DESCRIPTION

[0057] Copper-based organic-inorganic hybrid luminescent material, the chemical composition of the luminescent material is as follows:

[0058] (C4H 10 NO)4Cu2Br y I 6-y nH2O, C4H 10 NO is a morpholinium ion, X is a halogen, y=0-6, and n=0-1.

[0059] In one or more preferred embodiments, the luminescent material has at least one of the following chemical formulas:

[0060] (C4H 10 NO)4Cu2Br6、(C4H 10 NO)4Cu2I6·H2O.

[0061] When the chemical formula of the luminescent material is (C4H 10 NO)4Cu2Br6, the chemical composition is C 16 H 40 Br6Cu2N4O4, relative molecular mass is 958.05, space group is P1, unit cell parameters are α=105.765(2)°, β=104.696(2)°, γ=101.258(2)°;

[0062] Preferably, (C4H 10 The crystallographic parameters of NO)4Cu2Br6 are shown in Table 1:

[0063] Table 1. (C4H 10 NO)4Cu2Br6 crystallographic parameters

[0064]

[0065]

[0066] When the chemical formula of the luminescent material is (C4H 10 NO)4Cu2I6·H2O, the chemical composition is C 16 H 42 Cu2I6N4O5, relative molecular mass is 1259.01, space group is C2 / c, unit cell parameters are α=90°, β=98.518(2)°, γ=90°;

[0067] Preferably, (C4H 10 The crystallographic parameters of NO)4Cu2I6·H2O are shown in Table 2:

[0068] Table 2. (C4H 10 NO)4Cu2I6·H2O crystallographic parameters

[0069]

[0070] In one or more preferred embodiments, when the chemical composition of the luminescent material is (C4H 10 NO)4Cu2Br6, under 313nm ultraviolet light irradiation, it exhibits yellow-green luminescence with a luminescence peak of 537nm, a luminescence range of 400-751nm, an excitation range of 225-385nm, a luminescence lifetime of 106.9μs, and a quantum yield of 96.16%.

[0071] In one or more preferred embodiments, when the chemical composition of the luminescent material is (C4H 10 NO)4Cu2I6·H2O, under 317nm ultraviolet light irradiation, exhibits yellow-green luminescence with a luminescence peak of 547nm, a luminescence range of 410-800nm, and an excitation range corresponding to the luminescence peak of 265-372nm. The fluorescence lifetime of the yellow-green light is 183.5μs, and the quantum yield is 128.70%;

[0072] Preferably, under irradiation of 380nm ultraviolet light, it exhibits pure red light with a peak value of 679nm, a light emission range of 485-840nm, an excitation range corresponding to the light emission peak of 340-525nm, a fluorescence lifetime of red light of 1.2μs, and a quantum yield of 75.76%.

[0073] The method for preparing the copper-based organic-inorganic hybrid photoluminescent material of the present invention comprises the following steps:

[0074] Dissolve cuprous halide, hydrohalic acid, hypophosphorous acid and morpholine in an organic solvent, stir evenly, and then evaporate the solvent to crystallize to obtain the product.

[0075] In one or more preferred embodiments, the cuprous halide is cuprous bromide and / or cuprous iodide;

[0076] Preferably, the hydrohalic acid is hydrobromic acid and / or hydroiodic acid.

[0077] In one or more preferred embodiments, the molar ratio of morpholine to cuprous halide is (3.0-1.5):1, for example: 2.5:1, 2:1, 1.8:1; the molar ratio of cuprous halide to hydrohalic acid is 1:(1.0-4.0), for example: 1:2, 1:2.5, 1:3.0, 1:3.5.

[0078] According to the present invention, the purpose of adding hypophosphorous acid is to prevent oxidation, that is, to act as a strong reducing agent to avoid the oxidation of cuprous ions (Cu + ) is oxidized to copper ions (Cu 2+ ) to prevent the oxidation of halogen ions to halogen elements.

[0079] In one or more preferred embodiments, the molar ratio of hypophosphorous acid to cuprous halide is (1.0-3.0):1.

[0080] In one or more preferred embodiments, the organic solvent is at least one organic solvent selected from the group consisting of ketones, alcohols, esters, ethers, hydrocarbons, and nitrile solvents; preferably, acetone, ethanol, ethyl acetate, diethyl ether, cyclohexane, and / or acetonitrile.

[0081] In one or more preferred embodiments, to accelerate the reaction, heating or not can be selected according to the melting and boiling points of the solvent, and the heating temperature is preferably 25-80°C, for example: 30°C, 40°C, 50°C, 60°C, 70°C.

[0082] In one or more preferred embodiments, the stirring speed may be 200-2000 rpm, the stirring time may be 0.2-12 hours, and the time for volatilizing the solvent may be 3-60 days.

[0083] According to the present invention, a method for preparing a copper-based organic-inorganic hybrid luminescent material, in a preferred embodiment, comprises the following steps:

[0084] Dissolve cuprous bromide, hydrobromic acid, hypophosphorous acid and morpholine in acetone solvent and stir to obtain a clear solution. Place the clear solution in a fume hood and allow to stand at room temperature until (C4H 10 NO)4Cu2Br6 crystals are precipitated to obtain.

[0085] According to the present invention, another preferred embodiment of the method for preparing a copper-based organic-inorganic hybrid luminescent material comprises the following steps:

[0086] Dissolve cuprous iodide, hydroiodic acid, hypophosphorous acid and morpholine in acetone solution, heat and stir to obtain a clear solution, and place the clear solution in a fume hood at room temperature until (C4H 10 NO)4Cu2I6·H2O crystals are precipitated to obtain.

[0087] According to the present invention, the application of the copper-based organic-inorganic hybrid luminescent material as a rare earth-free luminescent material is preferably used in LEDs and information encryption.

[0088] According to the present invention, there is also provided an LED lamp comprising the copper-based organic-inorganic hybrid photoluminescent material.

[0089] In one or more preferred embodiments, the method for preparing the LED lamp comprises the following steps:

[0090] Select (C4H 10 NO)4Cu2Br6 or (C4H 10 NO)4Cu2I6·H2O single crystal is embedded in a UV 255nm pump LED chip to make an LED lamp.

[0091] In one or more preferred embodiments, based on (C4H 10 NO)4Cu2Br6 prepared LED lamp has a luminous peak at 562nm, based on (C4H 10 The luminescence peaks of the LED lamp prepared by NO)4Cu2I6·H2O are at 544nm and 680nm respectively.

[0092] According to the present invention, in one or more preferred embodiments, there is also provided an application of a copper-based organic-inorganic hybrid luminescent material in the field of information encryption;

[0093] Preferably, (C4H 10 NO)4Cu2Br6 or / and (C4H 10 NO)4Cu2I6·H2O is ground into powder and used for information encryption based on Morse code.

[0094] Preferably, (C4H 10 NO)4Cu2Br6 or / and (C4H 10 NO)4Cu2I6·H2O are dissolved in organic solvents and spin-coated into thin films for information encryption based on Morse code. Preferably, the organic solvent is at least one of ketones, alcohols, esters, ethers, hydrocarbons, and nitriles; more preferably, acetone, ethanol, ethyl acetate, diethyl ether, cyclohexane, and / or acetonitrile.

[0095] The above contents of the present invention are further described in detail below through specific embodiments, test examples and accompanying drawings, but this should not be understood as limiting the present invention to the following embodiments and test examples. All technologies implemented based on the contents of the present invention should be regarded as within the scope of the present invention.

[0096] Experimental procedures in the following Examples and Test Examples, where specific conditions are not specified, were generally performed under conventional conditions or those recommended by the manufacturer. Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those familiar to those skilled in the art. Furthermore, any methods and materials similar or equivalent to those described herein can be applied to the methods of the present invention. The preferred embodiments and materials described herein are for illustrative purposes only.

[0097] The chemical reagents involved in the examples, acetone, morpholine, cuprous bromide, cuprous iodide, hypophosphorous acid, hydrobromic acid, hydroiodic acid and were purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. and used without further purification.

[0098] Example 1

[0099] Dissolve 0.003 mol of cuprous bromide, 0.0015 mol of hypophosphorous acid, 0.003 mol of hydrobromic acid and 0.006 mol of morpholine in 5 ml of acetone solvent in sequence, stir with a magnetic stirrer until they are completely dissolved at a stirring speed of 1200 rpm to obtain a clear solution, move the clear solution to a fume hood and slowly evaporate the solvent for about two weeks to obtain a colorless, transparent block (C4H 10 NO)4Cu2Br6 crystals.

[0100] Under natural light and ultraviolet light, (C4H 10 NO)4Cu2Br6 crystal photo Figure 1 As shown. It can be seen that

[0101] (C4H 10 NO)4Cu2Br6 crystals are colorless and transparent under natural light, emit strong yellow-green light under 254nm ultraviolet light, and still emit yellow-green light under 365nm ultraviolet light.

[0102] Example 2

[0103] 0.003 mol of cuprous iodide, 0.0015 mol of hypophosphorous acid, 0.003 mol of hydroiodic acid and 0.006 mol of morpholine were dissolved in 5 ml of acetone solvent in sequence and stirred with a magnetic stirrer at a speed of 1200 rpm until they were completely dissolved to obtain a clear solution. The clear solution was moved to a fume hood and the solvent was slowly evaporated for about two weeks to obtain a light brown blocky transparent (C4H 10 NO)4Cu2I6·H2O crystals.

[0104] Under natural light and ultraviolet light, (C4H 10 NO)4Cu2I6·H2O crystal photo Figure 2 As shown. It can be seen that

[0105] (C4H10 NO)4Cu2I6·H2O crystals appear light brown and transparent under natural light, emit strong yellow-green light under 254nm ultraviolet light, and emit strong red light under 365nm ultraviolet light.

[0106] Example 3

[0107] 0.0015 mol of cuprous bromide, 0.0015 mol of cuprous iodide, 0.0015 mol of hypophosphorous acid, 0.0015 mol of hydrobromic acid, 0.0015 mol of hydroiodic acid, and 0.006 mol of morpholine were dissolved in 5 ml of acetone solvent in sequence, and stirred with a magnetic stirrer until they were completely dissolved at a stirring speed of 1200 rpm to obtain a clear solution. The clear solution was moved to a fume hood and the solvent was slowly evaporated for about two weeks to obtain a copper-based organic-inorganic hybrid luminescent material with the chemical formula (C4H 10 NO)4Cu2Br y I 6-y X6·nH2O, y=0~6, n=0~1.

[0108] Example 4

[0109] Dissolve 0.002 mol of cuprous bromide, 0.0015 mol of hypophosphorous acid, 0.004 mol of hydrobromic acid and 0.006 mol of morpholine in 5 ml of acetone solvent in sequence, stir with a magnetic stirrer until they are completely dissolved at a stirring speed of 1200 rpm to obtain a clear solution, move the clear solution to a fume hood and slowly evaporate the solvent for about two weeks to obtain a colorless, transparent block (C4H 10 NO)4Cu2Br6 crystals.

[0110] Example 5

[0111] Dissolve 0.004 mol of cuprous iodide, 0.0015 mol of hypophosphorous acid, 0.016 mol of hydroiodic acid and 0.006 mol of morpholine in 5 ml of acetone solvent in sequence, stir with a magnetic stirrer until they are completely dissolved at a stirring speed of 1200 rpm to obtain a clear solution, move the clear solution to a fume hood and slowly evaporate the solvent for about two weeks to obtain a light brown blocky transparent (C4H 10 NO)4Cu2I6·H2O crystals.

[0112] Example 6

[0113] The selected size is approximately 2×2×1.5mm 3 (C4H 10 NO)4Cu2Br6, embedded in a UV-pumped LED chip with an emission wavelength of 260nm, to prepare a green-white emitting LED lamp, as shown in the photo. Figure 9 As shown in a.

[0114] The emission spectra of LEDs prepared with working voltages in the range of 5.0-5.8V were tested. Figure 9 As shown in b, the test found that the luminescence peaks under different voltages showed the same peak position of 562nm (luminescence spectrum range is 450-700nm), indicating that the luminescence peaks based on (C4H 10 The LED prepared by NO)4Cu2Br6 showed high luminous stability. The luminous intensity was 2990cd / m when driven by 5.8V working voltage. 2 , the corresponding CIE color coordinates are (0.40, 0.51), such as Figure 9 As shown in c.

[0115] Example 7

[0116] The selected size is approximately 2×2×1.5mm 3 Example 2 prepared (C4H 10 NO)4Cu2I6·H2O, embedded in a UV-pumped LED chip with an emission wavelength of 260nm, to prepare a green-white emitting LED lamp, as shown in the photo. Figure 10 As shown in a.

[0117] The emission spectra of LEDs prepared with working voltages in the range of 5.0-5.8V were tested. Figure 10 It is found that the luminescence peak at different voltages shows the same peak position of 544nm (luminescence spectrum range is 450-700nm), indicating that the luminescence peak of (C4H 10 The LED prepared by NO)4Cu2I6·H2O showed high luminous stability. The luminous intensity was 3175cd / m when driven by 5.8V voltage. 2 , the corresponding CIE color coordinates are (0.35, 0.53), such as Figure 10 As shown in c.

[0118] Example 8

[0119] The (C4H 10 NO)4Cu2Br6 or / and (C4H 10 NO)4Cu2I6·H2O is ground into powder or made into thin film, and (C4H 10 NO)4Cu2Br6 or / and (C4H 10 NO)4Cu2I6·H2O is filled in the corresponding position of the circle or rectangle based on the Morse code design model (a total of 26 rows), and the white filling (C4H 10 NO)4Cu2Br6, brown filling (C4H 10 NO)4Cu2I6·H2O, used for information encryption. Figure 11 a is designed based on Morse code and needs to be filled (C4H 10 NO)4Cu2Br6 or (C4H 10 NO)4Cu2I6·H2O represents a 26-letter model; Figure 11 b is the simulated luminescence of the designed model after filling the sample under the irradiation of ultraviolet lamp at 254nm. The information transmitted is 13 letters, which are "BCFHJLPQVWXYZ" in sequence; Figure 11 c is the simulated luminescence of the designed model after filling the sample under the irradiation of ultraviolet lamp at 365nm. The information conveyed is 13 letters, which are "DRUSOENKATIMG" in sequence.

[0120] The 26 letters can be combined arbitrarily to convey information. Depending on the content of the information to be conveyed, the 26 lines of graphics in the designed model can appear multiple times or not, or can appear in other orders.

[0121] Test Example 1

[0122] The size selected under the microscope is about 0.40×0.50×0.3mm 3 (C4H) of Example 1 10 NO)4Cu2Br6 crystal, single crystal X-ray diffraction test at 150K, according to the test results, the space group of the crystal is P1, and the unit cell parameters are α=105.765(2), β=104.696(2), γ=101.258(2), according to the CIF file obtained by analyzing the single crystal, the diamond plot is obtained as follows Figure 3 (a, b) shows the structure. 10 NO)4Cu2Br6 crystal polycrystalline powder test X-ray diffraction curve and simulated curve spectrum are compared to obtain Figure 3 c, it can be seen that the purity of the crystal is very high.

[0123] Test Example 2

[0124] The size selected under the microscope is about 0.40×0.50×0.3mm 3 (C4H) of Example 2 10 NO)4Cu2I6·H2O crystal, a single crystal X-ray diffraction test was performed at 273K. According to the test results, the space group of the crystal is C2 / c, and the unit cell parameters are α=90°,β=98.518(2)°,γ=90°,according to the CIF file obtained by analyzing the single crystal, the diamond plot is obtained as follows Figure 4 (a, b) shows the structure.10 NO)4Cu2I6·H2O crystal polycrystalline powder test X-ray diffraction curve and simulated curve spectrum are compared to obtain Figure 4 c, it can be seen that the purity of the crystal is very high.

[0125] Test Example 3

[0126] Weigh about 0.2 g of (C4H 10 The NO)4Cu2Br6 crystal powder sample is covered on the center of the barium sulfate substrate surface and the measured data are plotted as follows Figure 5 From the ultraviolet spectrum absorption diagram shown in a, it can be seen that its absorption peak is at 347nm and the fitting band gap is 2.54eV.

[0127] Weigh about 0.2 g of (C4H 10 The NO)4Cu2I6·H2O crystal powder sample was covered on the center of the barium sulfate substrate surface and the measured data were plotted as follows Figure 5 From the ultraviolet spectrum absorption diagram shown in b, it can be seen that it has double absorption peaks at 227nm and 358nm respectively, and the fitting band gap is 1.81eV.

[0128] Test Example 4

[0129] The (C4H 10 NO)4Cu2Br6 crystal photoluminescence spectrum, found (C4H 10 NO)4Cu2Br6 exhibits yellow-green luminescence with a peak value of 537nm (luminescence range of 400-751nm) under 313nm ultraviolet pumping, and the excitation range corresponding to the luminescence peak is 225-385nm. Figure 6 a; the luminescence lifetime is 106.9μs (as shown in Figure 6 b), the quantum yield is 96.16% (as shown in Figure 6 c).

[0130] Test Example 5

[0131] The (C4H 10 NO)4Cu2I6·H2O crystals, it was found that (C4H 10 NO)4Cu2I6·H2O exhibits yellow-green luminescence with a luminescence peak of 547nm (luminescence range of 410-800nm) under 317nm ultraviolet pumping, and the excitation range corresponding to the luminescence peak is 265-372nm. Figure 7 a; the yellow-green light lifetime is 183.5μs (as shown in Figure 7 b), the quantum yield is 128.70% (as shown in Figure 7 c).

[0132] Test Example 6

[0133] The (C4H 10 NO)4Cu2I6·H2O exhibits pure red luminescence with a luminescence peak of 679nm (luminescence range of 485-840nm) under 380nm ultraviolet pumping. The excitation range corresponding to the luminescence peak is 340-525nm. Figure 8 a; the lifetime of red light is 1.2μs (as shown in Figure 8 b), the quantum yield is 75.76% (as shown in Figure 8 c).

[0134] Test Example 7

[0135] The (C4H 10 NO)4Cu2Br6 or / and (C4H 10 NO)4Cu2I6·H2O sample was ground into powder, and (C4H 10 NO)4Cu2Br6 or / and (C4H 10 NO)4Cu2I6·H2O is filled in the circular or rectangular position based on the Morse code design model, and the white filling (C4H 10 NO)4Cu2Br6, brown filling (C4H 10 NO)4Cu2I6·H2O, used for information encryption. Figure 12 a is a model of "QFNU" designed based on Morse code (white needs to be filled (C4H 10 NO)4Cu2Br6, brown needs to be filled (C4H 10 NO)4Cu2I6·H2O); Figure 12 b is the simulated luminescence of the designed model after filling the sample under the irradiation of ultraviolet lamp at 254nm, and the transmitted information is "QF"; Figure 12 c is the simulated luminescence of the designed model after filling the sample under the irradiation of ultraviolet lamp at 365nm, and the information transmitted is "NU". Figure 12 d is a model made based on the representative “QFNU” designed based on Morse code; Figure 12 e is a model filled with the design of "QFNU" based on Morse code (C4H 10 NO)4Cu2Br6 and (C4H 10 Actual photo after NO)4Cu2I6·H2O powder; Figure 12 f is the model filling (C4H 10 NO)4Cu2Br6 and (C4H 10A photo of NO)4Cu2I6·H2O powder irradiated with a 254nm UV lamp, showing the information "QF"; Figure 12 g is the model filling of QFNU based on Morse code design (C4H 10 NO)4Cu2Br6 and (C4H 10 A photo of NO)4Cu2I6·H2O powder illuminated by a 365nm UV lamp shows the message "NU." The combined illumination of 254nm and 365nm UV lamps shows the message "QFNU."

Claims

1. A copper-based organic-inorganic hybrid photoluminescent material, characterized in that: The chemical formula of the luminescent material is as follows: (C4H 10 NO)4Cu2Br y I 6-y nH2O, C4H 10 NO is the morpholinium ion, y=0~6, n=0~1.

2. The copper-based organic-inorganic hybrid photoluminescent material according to claim 1, characterized in that: The luminescent material has at least one of the following chemical compositions: (C4H 10 NO)4Cu2Br6、(C4H 10 NO)4Cu2I6·H2O。 3. The copper-based organic-inorganic hybrid photoluminescent material according to claim 2, characterized in that: When the chemical formula of the luminescent material is (C4H 10 NO)4Cu2Br6, the chemical composition is C 16 H 40 Br6Cu2N4O4, relative molecular mass is 958.05, space group is P 1, the unit cell parameters are a = 6.6738(10) Å, b = 11.0806(2) Å, c = 11.5671(2) Å, α =105.765(2) o , β =104.696(2) o , γ = 101.258(2) o ; When the chemical formula of the luminescent material is (C4H 10 NO)4Cu2I6·H2O, the chemical composition is C 16 H 42 Cu2I6N4O5, relative molecular mass is 1259.01, space group is C 2 / c , the unit cell parameters are a = 6.7981(4) Å, b = 22.9962(15) Å, c =21.3291(12) Å, α = 90 o , β =98.518(2) o , γ = 90 o .

4. The method for preparing the copper-based organic-inorganic hybrid photoluminescent material according to claim 1, comprising the following steps: Dissolve cuprous halide, hydrohalic acid, hypophosphorous acid and morpholine in an organic solvent, stir evenly, and then evaporate the solvent to crystallize to obtain the product.

5. The method for preparing the copper-based organic-inorganic hybrid photoluminescent material according to claim 4, characterized in that: The cuprous halide is cuprous bromide and / or cuprous iodide.

6. The method for preparing the copper-based organic-inorganic hybrid photoluminescent material according to claim 4, characterized in that: The hydrohalic acid is hydrobromic acid and / or hydroiodic acid.

7. The method for preparing the copper-based organic-inorganic hybrid photoluminescent material according to claim 4, characterized in that: The molar ratio of morpholine to cuprous halide is (3.0-1.5):1; the molar ratio of cuprous halide to hydrohalic acid is 1:(1.0-4.0).

8. The method for preparing the copper-based organic-inorganic hybrid photoluminescent material according to claim 4, characterized in that: The organic solvent is at least one organic solvent selected from the group consisting of ketones, alcohols, esters, ethers, hydrocarbons, and nitrile solvents.

9. The method for preparing the copper-based organic-inorganic hybrid photoluminescent material according to claim 4, characterized in that: The organic solvent is acetone, ethanol, ethyl acetate, ether, cyclohexane or / and acetonitrile.

10. Use of the copper-based organic-inorganic hybrid photoluminescent material according to claim 1 as a rare earth-free luminescent material.

11. An LED lamp comprising the copper-based organic-inorganic hybrid photoluminescent material according to claim 1.

12. Use of the copper-based organic-inorganic hybrid photoluminescent material according to claim 1 in the field of information encryption.

13. The use of the copper-based organic-inorganic hybrid photoluminescent material in the field of information encryption according to claim 12, characterized in that: (C4H 10 NO)4Cu2Br6 or / and (C4H 10 NO)4Cu2I6·H2O is ground into powder and used for information encryption based on Morse code; alternatively, (C4H 10 NO)4Cu2Br6 or / and (C4H 10 NO)4Cu2I6·H2O are dissolved in organic solvents to form thin films, which are used for information encryption based on Morse code. The organic solvent is at least one organic solvent selected from ketones, alcohols, esters, ethers, hydrocarbons, and nitrile solvents.

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