A full-spectrum solid-phase fluorescent material, its synthesis method and its application in light-emitting diodes

Abstract

The present invention belongs to the field of advanced material technology, and relates to luminescent materials, and specifically to a full-spectrum solid-phase fluorescent material, a synthesis method thereof, and its application in light-emitting diodes. Urea, boric acid, and phloroglucinol are mixed evenly, and then heated to 200-250°C for solid-phase reaction to obtain a solid-phase fluorescent material; wherein, the heating method is hot zone heating. The solid-phase fluorescent material provided by the present invention can achieve precise control of the fluorescence emission wavelength only by adjusting the ratio of reactants, and the prepared solid-phase fluorescent material has a long life and good stability, and can be used in the preparation of light-emitting diodes. The preparation method is fast and simple, and the reactants are cheap and easily available.

Description

Technical Field

[0001] The present invention belongs to the technical field of advanced materials and relates to luminescent materials, in particular to a full-spectrum solid-phase fluorescent material, a synthesis method thereof and an application thereof in light-emitting diodes. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to those skilled in the art.

[0003] Currently, solid fluorescent materials based on carbon dots have attracted much attention in the fields of light-emitting diodes, fingerprint recognition, biomedicine, etc. However, in solid-state films or powders, carbon dots often suffer from severe aggregation-induced quenching due to excessive fluorescence resonance energy transfer or direct π-π interactions, which limits the application of carbon dots in the solid-state field. In addition, in most cases, solid-state carbon dots exhibit single emission, but the field of luminescent display and lighting requires multi-color fluorescent materials as color converters. At the same time, most of the current syntheses of colorful solid-state carbon dots are obtained with the help of external matrices. It is rare to achieve precisely tuned full-color solid-state luminescence of carbon dots without any external matrix.

[0004] The inventors understand that some researchers have produced full-color solid-state fluorescent carbon dots using urea and phloroglucinol as raw reactants and water as solvent via a single-step microwave pyrolysis. However, further research has revealed that achieving a certain degree of fluorescence color adjustment requires simultaneous adjustment of the reactant ratio and microwave reaction power. This process also requires complex post-processing, resulting in complex preparation conditions and a long production time, making it difficult for industrialization. Summary of the Invention

[0005] In order to address the deficiencies of the prior art, the present invention aims to provide a full-spectrum solid-phase fluorescent material, a synthesis method thereof, and its application in light-emitting diodes. The solid-phase fluorescent material provided by the present invention can achieve precise control of the fluorescence emission wavelength simply by adjusting the ratio of reactants, and the prepared solid-phase fluorescent material has a long life and good stability, and can be used in the preparation of light-emitting diodes. The preparation method is fast and simple, and the reactants are cheap and readily available.

[0006] In order to achieve the above object, the technical solution of the present invention is:

[0007] In a first aspect, a method for synthesizing a full-spectrum solid-phase fluorescent material is provided, wherein urea, boric acid and phloroglucinol are uniformly mixed, and then heated to 200-250° C. for solid-phase reaction; wherein the heating method is hot zone heating.

[0008] The term "hot zone heating" as used herein refers to a method in which a heating medium is first heated and then heat is collected by the heating medium in the reaction system, such as water bath heating (where the heating medium is water), oil bath heating (where the heating medium is oil), or air bath heating (where the heating medium is air). A person skilled in the art can select an appropriate hot zone heating method based on the target heating temperature, such as air bath heating in a laboratory, heating jacket heating, or oven heating.

[0009] Building on the prior art described in the background, the present invention unexpectedly discovered that full-color solid-state fluorescent carbon dots can be produced by switching from microwave heating to thermal zone heating (particularly air bath heating such as oven heating). Adjusting the fluorescence color requires only adjusting the reactant ratio. However, the change in heating method reduced both fluorescence intensity and luminous efficiency, limiting its practical applications.

[0010] In order to solve the problems of fluorescence intensity and reduced fluorescence luminescence efficiency, the present invention unexpectedly discovered in further research that adding boric acid to the reactants on the basis of changing the heating method can not only ensure the acquisition of full-spectrum solid-phase fluorescent materials, but also significantly improve their fluorescence intensity and fluorescence luminescence efficiency.

[0011] Generally speaking, the reaction time of microwave heating is generally lower than that of other heating methods. However, the present invention unexpectedly found in the experiment that the reaction time of the synthesis method provided by the present invention by changing the heating method is as low as 6 minutes, that is, the reaction time is shorter and the safety factor is higher.

[0012] On the other hand, a full-spectrum carbon dot fluorescent material is obtained by the above synthesis method.

[0013] In a third aspect, an application of the above-mentioned full-spectrum carbon dot fluorescent material in a light-emitting diode.

[0014] The beneficial effects of the present invention are:

[0015] (1) The present invention utilizes urea, boric acid, and phloroglucinol in a one-step pyrolysis process to obtain a precisely tuned, full-color solid fluorescent material. The preparation process is rapid, solvent-free, energy-efficient, and minimally polluting, resolving the long reaction times and complex preparation conditions typically associated with preparing full-color solid-phase fluorescent materials. The one-step pyrolysis method for synthesizing solid-phase fluorescent materials is simple to operate, low-cost, highly practical, and requires no solvent, eliminating reliance on reaction solvents and making it suitable for mass production and industrial promotion.

[0016] (2) The present invention can obtain solid-phase fluorescent materials with different fluorescent colors by changing the ratio of urea, boric acid and phloroglucinol, and thus can be applied to the preparation of light-emitting diode devices with different colors.

[0017] (3) Experiments show that the maximum emission wavelength of the full-spectrum solid-phase fluorescent material prepared by the present invention can be finely adjusted in the range of 410-620 nm with an amplitude of 10 nm. It covers a wider spectral wavelength range and has more flexible wavelength tunability, which is more conducive to broadening the chromaticity of the light-emitting diode device prepared with it. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0019] Figure 1 This is a normalized fluorescence spectrum of the fluorescent carbon nanomaterial prepared in Examples 1-22 of the present invention;

[0020] Figure 2 This is a fluorescence spectrum of the solid fluorescent material prepared in Example 4 of the present invention, and the inset is an optical photograph of the solid fluorescent material under a 365nm ultraviolet lamp;

[0021] Figure 3 This is a fluorescence spectrum of the solid fluorescent material prepared in Example 8 of the present invention, and the inset is an optical photograph of the solid fluorescent material under a 365nm ultraviolet lamp;

[0022] Figure 4 This is a fluorescence spectrum of the solid fluorescent material prepared in Example 12 of the present invention, and the inset is an optical photograph of the solid fluorescent material under a 365nm ultraviolet lamp;

[0023] Figure 5 This is a fluorescence spectrum of the solid fluorescent material prepared in Example 16 of the present invention, and the inset is an optical photograph of the solid fluorescent material under a 365nm ultraviolet lamp;

[0024] Figure 6 This is a fluorescence spectrum of the solid fluorescent material prepared in Example 19 of the present invention, and the inset is an optical photograph of the solid fluorescent material under a 365nm ultraviolet lamp;

[0025] Figure 7 This is a fluorescence spectrum of the solid fluorescent material prepared in Example 22 of the present invention, and the inset is an optical photograph of the solid fluorescent material under a 365nm ultraviolet lamp;

[0026] Figure 8 The UV-visible absorption spectra of the solid fluorescent materials prepared in Examples 4, 8, 12, 16, 19, and 22 of the present invention are shown;

[0027] Figure 9 X-ray powder diffraction patterns of the solid fluorescent materials prepared in Examples 4, 8, 12, 16, 19, and 22 of the present invention;

[0028] Figure 10 The luminescence results of the LED device prepared in Example 23 of the present invention are shown in Figures a and b, respectively.

[0029] Figure 11 The luminescence results of the LED device prepared in Example 24 of the present invention are shown in Figures a and b, respectively.

[0030] Figure 12 The luminescence results of the LED device prepared in Example 25 of the present invention are shown in Figures a and b, respectively.

[0031] Figure 13 These are the luminescence results of the LED device prepared in Example 26 of the present invention, where a is the luminescence diagram of the LED device and b is the chromaticity diagram;

[0032] Figure 14 The luminescence results of the LED device prepared in Example 27 of the present invention are shown in Figures a and b, respectively.

[0033] Figure 15 The luminescence results of the LED device prepared in Example 28 of the present invention are shown in Figures a and b, respectively.

[0034] Figure 16 These are the fluorescence emission spectra of the solid fluorescent materials prepared in Comparative Example 1 and Example 8 of the present invention. DETAILED DESCRIPTION

[0035] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0036] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0037] As introduced in the background technology, the technical solution for preparing full-color solid-state fluorescent carbon dots using urea and phloroglucinol as raw material reactants in the prior art has problems such as complex preparation conditions and long preparation time. The present invention proposes a full-spectrum solid-phase fluorescent material, a synthesis method thereof, and its application in light-emitting diodes.

[0038] A typical embodiment of the present invention provides a method for synthesizing a full-spectrum solid-phase fluorescent material, which comprises uniformly mixing urea, boric acid, and phloroglucinol, and then heating the mixture to 200-250°C for solid-phase reaction; wherein the heating method is thermal zone heating.

[0039] Experiments show that the solid fluorescent material prepared by the present invention emits different fluorescent colors when excited by a 365nm ultraviolet lamp.

[0040] The solid phase reaction of the present invention refers to a reaction in which a solid phase raw material is treated without adding a solvent.

[0041] In some embodiments, the thermal zone heating is air bath heating.

[0042] In some embodiments, the heat zone heating is oven heating. In experimental operation, oven heating can heat the reaction system more uniformly.

[0043] The solid phase reaction time is not less than 6 minutes. In some embodiments, the solid phase reaction time is 10 to 12 minutes.

[0044] In some embodiments, the molar ratio of boric acid, urea, and phloroglucinol is 1:1.8-2.2:0.001-10, preferably 1:1.8-2.2:0.01-8.5.

[0045] In some embodiments, the method for uniformly mixing urea, boric acid, and phloroglucinol is grinding. Grinding can better mix the three raw materials without introducing a solvent, thereby improving the efficiency of the solid phase reaction.

[0046] Another embodiment of the present invention provides a full-spectrum carbon dot fluorescent material obtained by the above-mentioned synthesis method.

[0047] A third embodiment of the present invention provides an application of the above-mentioned full-spectrum carbon dot fluorescent material in a light-emitting diode.

[0048] In some embodiments, the light emitting diode is an LED lamp.

[0049] Specifically, the LED lamp includes a UV chip and the solid fluorescent material, wherein the solid fluorescent material is encapsulated on the UV chip. More specifically, the method may be: uniformly mixing the solid fluorescent material with encapsulation glue, coating the mixed material on the UV chip, and curing the mixture.

[0050] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments and comparative examples.

[0051] Example 1

[0052] Weigh 0.4 g of urea, 0.2 g of boric acid, and 0.004 g of phloroglucinol, place them in a mortar, grind and mix thoroughly, transfer them to a 50 mL beaker, and place them in a 240°C oven for solid-phase reaction. After 10 minutes, a solid-phase fluorescent material with an emission wavelength of 410 nm can be obtained.

[0053] Example 2

[0054] Weigh 0.4 g of urea, 0.2 g of boric acid, and 0.0025 g of phloroglucinol, place them in a mortar, grind and mix thoroughly, transfer them to a 50 mL beaker, and place them in a 240°C oven for solid-phase reaction. After 10 minutes, a solid-phase fluorescent material with an emission wavelength of 420 nm can be obtained.

[0055] Example 3

[0056] Weigh 0.4 g of urea, 0.2 g of boric acid, and 0.005 g of phloroglucinol, place them in a mortar, grind and mix thoroughly, transfer them to a 50 mL beaker, and place them in a 240°C oven for solid-phase reaction. After 10 minutes, a solid-phase fluorescent material with an emission wavelength of 430 nm can be obtained.

[0057] Example 4

[0058] Weigh 0.4 g of urea, 0.2 g of boric acid, and 0.0084 g of phloroglucinol, place them in a mortar, grind and mix thoroughly, transfer them to a 50 mL beaker, and place them in a 240°C oven for solid-phase reaction. After 10 minutes, a solid-phase fluorescent material with an emission wavelength of 440 nm can be obtained.

[0059] Example 5

[0060] Weigh 0.4 g of urea, 0.2 g of boric acid, and 0.0126 g of phloroglucinol, place them in a mortar, grind and mix thoroughly, transfer them to a 50 mL beaker, and place them in a 240°C oven for solid-phase reaction. After 10 minutes, a solid-phase fluorescent material with an emission wavelength of 450 nm can be obtained.

[0061] Example 6

[0062] Weigh 0.4 g of urea, 0.2 g of boric acid, and 0.0294 g of phloroglucinol, place them in a mortar, grind and mix thoroughly, transfer them to a 50 mL beaker, and place them in a 240°C oven for solid-phase reaction. After 10 minutes, a 460 nm solid-phase fluorescent material can be obtained.

[0063] Example 7

[0064] Weigh 0.4 g of urea, 0.2 g of boric acid, and 0.042 g of phloroglucinol, place them in a mortar, grind and mix thoroughly, transfer them to a 50 mL beaker, and place them in a 240°C oven for solid-phase reaction. After 10 minutes, a 470 nm solid-phase fluorescent material can be obtained.

[0065] Example 8

[0066] Weigh 0.4 g of urea, 0.2 g of boric acid, and 0.05 g of phloroglucinol, place them in a mortar, grind and mix thoroughly, transfer them to a 50 mL beaker, and place them in a 240°C oven for solid-phase reaction. After 10 minutes, a 480 nm solid-phase fluorescent material can be obtained.

[0067] Example 9

[0068] Weigh 0.4 g of urea, 0.2 g of boric acid, and 0.063 g of phloroglucinol, place them in a mortar, grind and mix thoroughly, transfer them to a 50 mL beaker, and place them in a 240°C oven for solid-phase reaction. After 10 minutes, a 490 nm solid-phase fluorescent material can be obtained.

[0069] Example 10

[0070] Weigh 0.4 g of urea, 0.2 g of boric acid, and 0.084 g of phloroglucinol, place them in a mortar, grind and mix thoroughly, transfer them to a 50 mL beaker, and place them in a 240°C oven for solid-phase reaction. After 10 minutes, a 500 nm solid-phase fluorescent material can be obtained.

[0071] Example 11

[0072] Weigh 0.4 g of urea, 0.2 g of boric acid, and 0.1 g of phloroglucinol, place them in a mortar, grind and mix thoroughly, transfer them to a 50 mL beaker, and place them in a 240 °C oven for solid-phase reaction. After 10 minutes, a 510 nm solid-phase fluorescent material can be obtained.

[0073] Example 12

[0074] Weigh 0.4 g of urea, 0.2 g of boric acid, and 0.126 g of phloroglucinol, place them in a mortar, grind and mix thoroughly, transfer them to a 50 mL beaker, and place them in a 240°C oven for solid-phase reaction. After 10 minutes, a 520 nm solid-phase fluorescent material can be obtained.

[0075] Example 13

[0076] Weigh 0.4 g of urea, 0.2 g of boric acid, and 0.168 g of phloroglucinol, place them in a mortar, grind and mix thoroughly, transfer them to a 50 mL beaker, and place them in a 240°C oven for solid-phase reaction. After 10 minutes, a 530 nm solid-phase fluorescent material can be obtained.

[0077] Example 14

[0078] Weigh 0.4 g of urea, 0.2 g of boric acid, and 0.252 g of phloroglucinol, place them in a mortar, grind and mix thoroughly, transfer them to a 50 mL beaker, and place them in a 240°C oven for solid-phase reaction. After 10 minutes, a 540 nm solid-phase fluorescent material can be obtained.

[0079] Example 15

[0080] Weigh 0.4 g of urea, 0.2 g of boric acid, and 0.378 g of phloroglucinol, place them in a mortar, grind and mix thoroughly, transfer them to a 50 mL beaker, and place them in a 240°C oven for solid-phase reaction. After 10 minutes, a 550 nm solid-phase fluorescent material can be obtained.

[0081] Example 16

[0082] Weigh 0.4 g of urea, 0.2 g of boric acid, and 0.63 g of phloroglucinol, place them in a mortar, grind and mix thoroughly, transfer them to a 50 mL beaker, and place them in a 240°C oven for solid-phase reaction. After 10 minutes, a 560 nm solid-phase fluorescent material can be obtained.

[0083] Example 17

[0084] Weigh 0.4 g of urea, 0.2 g of boric acid, and 0.714 g of phloroglucinol, place them in a mortar, grind and mix thoroughly, transfer them to a 50 mL beaker, and place them in a 240°C oven for solid-phase reaction. After 10 minutes, a 570 nm solid-phase fluorescent material can be obtained.

[0085] Example 18

[0086] Weigh 0.4 g of urea, 0.2 g of boric acid, and 0.84 g of phloroglucinol, place them in a mortar, grind and mix thoroughly, transfer them to a 50 mL beaker, and place them in a 240°C oven for solid-phase reaction. After 10 minutes, a 580 nm solid-phase fluorescent material can be obtained.

[0087] Example 19

[0088] Weigh 0.4 g of urea, 0.2 g of boric acid, and 1.01 g of phloroglucinol, place them in a mortar, grind and mix thoroughly, transfer them to a 50 mL beaker, and place them in a 240°C oven for solid-phase reaction. After 10 minutes, a 590 nm solid-phase fluorescent material can be obtained.

[0089] Example 20

[0090] Weigh 0.4 g of urea, 0.2 g of boric acid, and 1.26 g of phloroglucinol, place them in a mortar, grind and mix thoroughly, transfer them to a 50 mL beaker, and place them in a 240°C oven for solid-phase reaction. After 10 minutes, a 600 nm solid-phase fluorescent material can be obtained.

[0091] Example 21

[0092] Weigh 0.4 g of urea, 0.2 g of boric acid, and 1.5 g of phloroglucinol, place them in a mortar, grind and mix thoroughly, transfer them to a 50 mL beaker, and place them in a 240°C oven for solid-phase reaction. After 10 minutes, a 610 nm solid-phase fluorescent material can be obtained.

[0093] Example 22

[0094] Weigh 0.4 g of urea, 0.2 g of boric acid, and 3.42 g of phloroglucinol, place them in a mortar, grind and mix thoroughly, transfer them to a 50 mL beaker, and place them in a 240°C oven for solid-phase reaction. After 10 minutes, a 620 nm solid-phase fluorescent material can be obtained.

[0095] Example 23

[0096] An LED device was prepared using the materials obtained in Example 4. A UV LED chip with an emission wavelength of 365 nm was selected as the light pump. A certain amount of solid fluorescent material was uniformly mixed with a 1:4 mass ratio of organic silica gel and curing agent. An appropriate amount of the mixture was then dropwise added to the UV chip and dried at 100°C for 1 hour. The LED device was then prepared.

[0097] Example 24

[0098] An LED device was prepared using the materials obtained in Example 8. A UV LED chip with an emission wavelength of 365 nm was selected as the light pump. A certain amount of solid fluorescent material was uniformly mixed with a 1:4 mass ratio of organic silica gel and curing agent. An appropriate amount of the mixture was then dropwise added to the UV chip and dried at 100°C for 1 hour. The LED device was then prepared.

[0099] Example 25

[0100] An LED device was prepared using the materials obtained in Example 12. A UV LED chip with an emission wavelength of 365 nm was selected as the light pump. A certain amount of solid fluorescent material was uniformly mixed with a 1:4 mass ratio of organic silica gel and curing agent. An appropriate amount of the mixture was then dropwise added to the UV chip and dried at 100°C for 1 hour. The LED device was then prepared.

[0101] Example 26

[0102] An LED device was prepared using the materials obtained in Example 16. A UV LED chip with an emission wavelength of 365 nm was selected as the light pump. A certain amount of solid fluorescent material was uniformly mixed with a 1:4 mass ratio of organic silica gel and curing agent. An appropriate amount of the mixture was then dropwise added to the UV chip and dried at 100°C for 1 hour. The LED device was then fabricated.

[0103] Example 27

[0104] An LED device was prepared using the materials obtained in Example 19. A UV LED chip with an emission wavelength of 365 nm was selected as the light pump. A certain amount of solid fluorescent material was uniformly mixed with a 1:4 mass ratio of organic silica gel and curing agent. An appropriate amount of the mixture was then dropwise added to the UV chip and dried at 100°C for 1 hour. The LED device was then fabricated.

[0105] Example 28

[0106] An LED device was prepared by mixing the materials obtained in Examples 12 and 22. A blue LED chip with an emission wavelength of 450 nm was selected as the light pump. A certain amount of solid fluorescent material was evenly mixed with a 1:4 mass ratio of organic silica gel and curing agent. An appropriate amount of the mixture was then dropwise added to the UV chip and dried at 100°C for 1 hour. The LED device was then prepared.

[0107] like Figure 1 Shown are normalized fluorescence spectra of the solid fluorescent materials prepared in Examples 1-22, and the spectral lines from left to right are the normalized fluorescence spectra of the solid fluorescent materials prepared in Examples 1-22, indicating that the preparation method can accurately tune the CDs wavelength.

[0108] like Figure 2 The figure shows the fluorescence spectrum of the solid fluorescent material prepared in Example 4. The optimal excitation wavelength is at 382 nm, and the maximum emission peak is at 420 nm. The inset shows that the solid fluorescent material prepared in Example 4 emits blue fluorescence under a 365 nm ultraviolet lamp.

[0109] like Figure 3 The figure shows the fluorescence spectrum of the solid fluorescent material prepared in Example 8. The optimal excitation wavelength is at 417 nm, and the maximum emission peak is at 480 nm. The inset shows that the solid fluorescent material prepared in Example 8 emits blue-green fluorescence under a 365 nm ultraviolet lamp.

[0110] like Figure 4 The figure shows the fluorescence spectrum of the solid fluorescent material prepared in Example 12. The optimal excitation wavelength is at 467 nm, and the maximum emission peak is at 520 nm. The inset shows that the solid fluorescent material prepared in Example 12 emits green fluorescence under a 365 nm ultraviolet lamp.

[0111] like Figure 5 The figure shows the fluorescence spectrum of the solid fluorescent material prepared in Example 16. The optimal excitation wavelength is at 469 nm, and the maximum emission peak is at 560 nm. The inset shows that the solid fluorescent material prepared in Example 16 emits yellow fluorescence under a 365 nm ultraviolet lamp.

[0112] like Figure 6The figure shows the fluorescence spectrum of the solid fluorescent material prepared in Example 19. The optimal excitation wavelength is at 469 nm, and the maximum emission peak is at 590 nm. The inset shows that the solid fluorescent material prepared in Example 19 emits orange fluorescence under a 365 nm ultraviolet lamp.

[0113] like Figure 7 Shown is the fluorescence spectrum of the solid fluorescent material prepared in Example 22. The optimal excitation wavelength is at 468 nm, and the maximum emission peak is at 620 nm. The inset shows that the solid fluorescent material prepared in Example 22 emits red fluorescence under a 365 nm ultraviolet lamp.

[0114] like Figure 8 Shown are the UV-visible absorption spectra of the solid fluorescent materials prepared in Examples 4, 8, 12, 16, 19, and 22, indicating that as the ratio of phloroglucinol to urea boric acid continues to increase, the absorption peak of the solid fluorescent material continues to red-shift.

[0115] like Figure 9 Shown are the X-ray powder diffraction patterns of the solid fluorescent materials prepared in Examples 4, 8, 12, 16, 19, and 22, indicating the presence of a peak at around 23°.

[0116] like Figure 10 a shows the LED device prepared in Example 23, Figure 10 b is the corresponding chromaticity diagram, coordinates (0.1614, 0.1223).

[0117] like Figure 11 a shows the LED device prepared in Example 24, Figure 11 b is the corresponding chromaticity diagram, coordinates (0.1735, 0.241).

[0118] like Figure 12 a shows the LED device prepared in Example 25, Figure 12 b is the corresponding chromaticity diagram, coordinates (0.2988, 0.6202).

[0119] like Figure 13 a shows the LED device prepared in Example 26, Figure 13 b is the corresponding chromaticity diagram, coordinates (0.4504, 0.4767).

[0120] like Figure 14 a shows the LED device prepared in Example 27, Figure 14 b is the corresponding chromaticity diagram, coordinates (0.5031, 0.4767).

[0121] like Figure 15 a shows the LED device prepared in Example 28, Figure 15b is the corresponding chromaticity diagram, coordinates (0.2768, 0.2936).

[0122] Comparative Example 1

[0123] Weigh 0.4 g of urea and 0.0084 g of phloroglucinol, place them in a mortar, grind and mix thoroughly, transfer them to a 50 mL beaker, and place them in a 240°C oven for solid-phase reaction. After 10 minutes, the solid-phase fluorescent material can be obtained.

[0124] The fluorescence emission spectrum of the comparative example 1 and the fluorescence emission spectrum of the embodiment 4 are stacked as shown in FIG. Figure 16 As shown, the black spectrum line is the fluorescence spectrum line of the material of Example 4, with an emission wavelength of 440nm, and the red spectrum line is the fluorescence spectrum line of the material of Comparative Example 1, with an emission wavelength of 455nm. By comparing the fluorescence intensities, it is found that the fluorescence intensity of Example 4 is stronger than that of Comparative Example 1. This proves that boric acid can significantly increase the fluorescence intensity of the material.

[0125] Comparative Example 2

[0126] Weigh 0.2 g of boric acid, 0.4 g of urea, and 0.0073 g of resorcinol in a molar ratio of 1:2:0.02. Place them in a mortar, grind and mix thoroughly, transfer them to a 50 mL beaker, and place them in a 240°C oven for solid-phase reaction. After 10 minutes, the solid-phase luminescent material can be obtained.

[0127] Comparative Example 3

[0128] Weigh 0.2 g of boric acid, 0.4 g of urea, and 0.0073 g of hydroquinone in a molar ratio of 1:2:0.02. Place them in a mortar, grind and mix thoroughly, transfer them to a 50 mL beaker, and place them in a 240°C oven for solid-phase reaction. After 10 minutes, the solid-phase luminescent material can be obtained.

[0129] Comparative Example 4

[0130] Weigh 0.2 g of boric acid, 0.4 g of urea, and 0.0073 g of catechol in a molar ratio of 1:2:0.02. Place them in a mortar, grind and mix thoroughly, transfer them to a 50 mL beaker, and place them in a 240°C oven for solid-phase reaction. After 10 minutes, the solid-phase luminescent material can be obtained.

[0131] Comparative Example 5

[0132] Weigh 0.2 g of boric acid, 0.64 g of guanidine hydrochloride, and 0.0084 g of phloroglucinol in a molar ratio of 1:2:0.02. Place them in a mortar, grind and mix thoroughly, transfer them to a 50 mL beaker, and place them in a 240°C oven for solid-phase reaction. After 10 minutes, the solid-phase luminescent material can be obtained.

[0133] Comparative Example 6

[0134] Weigh 0.2 g of boric acid, 0.45 g of methylamine hydrochloride, and 0.0084 g of phloroglucinol in a molar ratio of 1:2:0.02. Place them in a mortar, grind and mix thoroughly, transfer them to a 50 mL beaker, and place them in a 240°C oven for solid-phase reaction. After 10 minutes, a solid-phase luminescent material can be obtained.

[0135] Comparative Example 7

[0136] Weigh 0.2 g of boric acid, 0.54 g of ethylamine hydrochloride, and 0.0084 g of phloroglucinol in a molar ratio of 1:2:0.02. Place them in a mortar, grind and mix thoroughly, transfer them to a 50 mL beaker, and place them in a 240°C oven for solid-phase reaction. After 10 minutes, the solid-phase luminescent material can be obtained.

[0137] Comparative Example 8

[0138] Weigh 0.2 g of boric acid, 0.62 g of propylamine hydrochloride, and 0.0084 g of phloroglucinol in a molar ratio of 1:2:0.02. Place them in a mortar, grind and mix thoroughly, transfer them to a 50 mL beaker, and place them in a 240°C oven for solid-phase reaction. After 10 minutes, a solid-phase luminescent material can be obtained.

[0139] Comparative Example 9

[0140] Weigh 0.2 g of boric acid, 0.86 g of ethylenediamine hydrochloride, and 0.0084 g of phloroglucinol in a molar ratio of 1:2:0.02. Place them in a mortar, grind and mix thoroughly, transfer them to a 50 mL beaker, and place them in a 240°C oven for solid-phase reaction. After 10 minutes, a solid-phase luminescent material can be obtained.

[0141] As shown in Table 1, the present invention compares the fluorescence quantum yields of Example 1 and Comparative Examples 1-9, finding that solid-phase fluorescent materials synthesized with other phenolic and nitrogen-containing substances have low fluorescence luminescence efficiencies and cannot synthesize full-spectrum solid-state fluorescent materials. This demonstrates that phloroglucinol and urea cannot be replaced by other analogs.

[0142] Table 1 is a comparison of the fluorescent luminous efficiency of the solid fluorescent materials prepared in Example 4 of the present invention and Comparative Examples 1-9

[0143]

[0144] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A method for synthesizing a full-spectrum solid-phase fluorescent material, characterized in that: The urea, boric acid and phloroglucinol are uniformly mixed and then heated to 200-250° C. for solid phase reaction to obtain the product; wherein the heating method is hot zone heating; and the molar ratio of boric acid, urea and phloroglucinol is 1:1.8-2.2:0.001-10.

2. The method for synthesizing the full-spectrum solid-phase fluorescent material according to claim 1, wherein: The heat zone heating is air bath heating.

3. The method for synthesizing the full-spectrum solid-phase fluorescent material according to claim 1, wherein: The hot zone heating is oven heating.

4. The method for synthesizing the full-spectrum solid-phase fluorescent material according to claim 1, wherein: The solid phase reaction time is 10~12 min.

5. The method for synthesizing the full-spectrum solid-phase fluorescent material according to claim 1, wherein: The molar ratio of boric acid, urea and phloroglucinol is 1:1.8~2.2:0.01~8.

5.

6. The method for synthesizing the full-spectrum solid-phase fluorescent material according to claim 1, wherein: The method for uniformly mixing urea, boric acid and phloroglucinol is grinding.

7. A full-spectrum solid-phase fluorescent material, characterized in that: Obtained by the synthesis method according to any one of claims 1 to 6.

8. Use of the full-spectrum solid-phase fluorescent material according to claim 7 in a light-emitting diode.

9. The use according to claim 8, characterized in that: The light emitting diode is an LED lamp.

10. The use according to claim 9, characterized in that: The LED lamp comprises an ultraviolet light chip and the full-spectrum solid-phase fluorescent material, and the full-spectrum solid-phase fluorescent material is packaged on the ultraviolet light chip.

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