White light emitting material and preparation method and application thereof

Abstract

The invention discloses a white light-emitting material and a preparation method and application thereof, and relates to the technical field of light-emitting materials, the chemical formula of the white light-emitting material is Pb1-xClI: xM, 0 lt; x is greater than or equal to 0.2, and M is Cu, Zn or Fe. In the invention, the white light luminescent material Pb1-xClI: xM is PbICl doped with metal ions (Cu < 2 + >, Zn < 2 + > or Fe < 2 + >), the metal ions replace Pb ions and are doped into the PbICl, so that the PbICl generates white light broadband emission of self-trapping excitons, and the central peak position of the fluorescence emission peak of the self-trapping excitons is 650-700nm. The Pb1-xClI: xM provided by the invention can realize efficient white light emission, blue light pollution can be reduced to the greatest extent by constructing a light-emitting device by using the white light-emitting material, a self-absorption effect is avoided, meanwhile, the problem of secondary energy loss in a traditional LED light excitation process can be solved, and the structure of the device can be simplified.

Description

Technical Field

[0001] The present invention relates to the technical field of luminescent materials, and particularly to a white light emitting material, a preparation method thereof and an application thereof. Background Art

[0002] Currently, commercially available white light emitting diodes (LEDs) mainly use blue LEDs as excitation light sources to excite phosphors to generate complementary colors, thereby achieving mixed light emission and forming white light. However, on the one hand, using blue LEDs as excitation light sources results in a very high proportion of blue light in the generated white light spectrum, which in turn causes serious blue light pollution problems. On the other hand, the above method involves two energy conversion processes of light excitation and light conversion, resulting in a low efficiency of white light emission and causing a large amount of energy waste. Therefore, designing healthy and efficient white light emitting materials and light emitting devices has important scientific research and commercial value for the development of a new generation of environmentally optimized high-quality white light devices.

[0003] In recent years, single-component white light emitting materials have received extensive attention and have very important application potential in the field of high-efficiency LED lighting devices. Among these materials, self-trapped exciton emission materials induced by exciton-phonon coupling are considered to be ideal candidates for the next generation of healthy and high-quality materials. The broad spectral emission characteristics of self-trapped excitons can effectively cover the entire visible light spectrum band to achieve full-spectrum lighting. Using self-trapped state materials as a single light emitting layer to construct a light emitting device can minimize blue light pollution (without a blue light excitation source) from the source, avoid self-absorption effects, and at the same time overcome the problem of secondary energy loss in the traditional LED light excitation process and simplify the device structure.

[0004] Therefore, developing single-component white light emitting materials is of great significance. Summary of the Invention

[0005] Based on the above deficiencies of the prior art, the object of the present invention is to provide a white light emitting material, a preparation method thereof and an application thereof, aiming to construct a light emitting device with this white light emitting material to reduce blue light pollution from the source.

[0006] The technical solution of the present invention is as follows:

[0007] In the first aspect of the present invention, a white light emitting material is provided, wherein the chemical formula of the white light emitting material is Pb 1-x ClI:xM, where 0 < x ≤ 0.2 and M is Cu, Zn or Fe.

[0008] In the second aspect of the present invention, a preparation method of the white light emitting material as described above in the present invention is provided, which includes the following steps:

[0009] Providing a supersaturated lead iodide solution, an MCl2 solution and a lead chloride solution; M is Cu, Zn or Fe;

[0010] Heat the MCl2 solution and the lead chloride solution to 60-100°C respectively;

[0011] Heat the supersaturated lead iodide solution to 60-90°C;

[0012] According to the stoichiometric ratio of each element in the chemical formula of the white light luminescent material, an MCl2 solution at a temperature of 60-100° C. and a lead chloride solution at a temperature of 60-100° C. are added dropwise to a supersaturated lead iodide solution at a temperature of 60-90° C., and stirred at a temperature of 60-90° C. for a preset time to obtain a suspension;

[0013] After the suspension is cooled to 40° C. or below, the supernatant is taken to obtain the white light luminescent material.

[0014] Optionally, after the suspension is cooled to 40° C. or below, taking the supernatant to obtain the white light luminescent material specifically comprises:

[0015] After the suspension is cooled to 40°C or below, take the supernatant;

[0016] The supernatant is placed on the surface of a substrate and dried to obtain the white light emitting material on the surface of the substrate.

[0017] Optionally, the concentration of the MCl2 solution is 0-0.04 mmol / mL, and the concentration of the MCl2 solution is not 0 mmol / mL; the concentration of the lead chloride solution is 0.006-0.02 mmol / mL.

[0018] Optionally, the method for preparing the supersaturated lead iodide solution comprises the following steps:

[0019] Lead iodide powder was dispersed in water at a ratio of 0.2 mmol:50 mL to form a supersaturated lead iodide solution.

[0020] Optionally, under stirring conditions, the MCl2 solution and the lead chloride solution are heated to 60-100°C, respectively, and stirred at 60-100°C for 0.5-1.5h.

[0021] Optionally, the preset time is 20min-2h.

[0022] The third aspect of the present invention provides a use of the white light luminescent material as described above in the present invention and / or the white light luminescent material prepared by the preparation method as described above in the present invention in a light emitting device.

[0023] Optionally, the light emitting device is an LED.

[0024] A fourth aspect of the present invention provides a light-emitting device, wherein the light-emitting device comprises the white-light luminescent material of the present invention as described above and / or the white-light luminescent material prepared by the preparation method of the present invention as described above.

[0025] Beneficial effect: In the present invention, the white light luminescent material Pb 1-x ClI: xM is a metal ion (Cu 2+ 、Zn 2+ or Fe 2+ ) doped PbICl, metal ions replace Pb ions and are doped into PbICl, so that PbICl produces white light broadband emission of self-trapped excitons, and the central peak position of the fluorescence emission peak of the self-trapped excitons is 650-700nm. The Pb provided by the present invention 1-x ClI:xM can achieve efficient white light emission. Constructing light-emitting devices with this white light-emitting material can minimize blue light pollution and avoid self-absorption effects. At the same time, it can overcome the problem of secondary energy loss in the traditional LED light excitation process and simplify the device structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 These are optical microscope images of PbICl prepared at different temperatures in Comparative Example 1, where (a) is 60°C, (b) is 80°C, and (c) is 100°C.

[0027] Figure 2 This is the Raman spectrum of PbICl prepared at 80°C in Comparative Example 1.

[0028] Figure 3 is the Pb in Example 1 0.98 Scanning electron microscope and energy spectrum test results of ICl: 0.02Cu, where (a) is the scanning electron microscope image, (b) is the Pb element distribution map, (c) is the Cu element distribution map, (d) is the Cl element distribution map, (e) is the I element distribution map, and (f) is the total element distribution spectrum map.

[0029] Figure 4 (a) is the room temperature fluorescence luminescence spectrum of PbICl prepared at 90°C in Comparative Example 1; (b) is the room temperature fluorescence luminescence spectrum of PbICl prepared at 90°C in Example 2 0.99 ICl: Room temperature fluorescence luminescence spectrum of 0.01Cu; (c) is the Pb in Example 3 0.95 ICl: Room temperature fluorescence luminescence spectrum of 0.05Cu; (d) is the Pb in Example 4 0.85 Room temperature fluorescence spectrum of ICl:0.15Cu.

[0030] Figure 5 (a) is Pb in Example 10.98 Room-temperature fluorescence emission spectra of ICl: 0.02Cu; (b) is Pb in Example 5 0.98 Room-temperature fluorescence emission spectra of ICl: 0.02Fe; (c) is Pb in Example 6 0.98 Room-temperature fluorescence emission spectra of ICl: 0.02Zn

[0031] Figure 6 is Pb in Example 3 0.95 Fluorescence spectra of ICl: 0.05Cu at different temperatures Specific embodiments

[0032] The present invention provides a white light-emitting material, its preparation method and application. To make the purpose, technical solution and effect of the present invention clearer and more definite, the present invention is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention

[0033] Unless otherwise defined, all technical terms and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the description of the present invention in this specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention

[0034] An embodiment of the present invention provides a white light-emitting material, wherein the chemical formula of the white light-emitting material is Pb 1- x ClI: xM, where 0 < x ≤ 0.2, and M is Cu, Zn or Fe (where the ratio of 1 - x to x is the molar ratio or atomic number ratio of Pb to M, and the molar ratio of Pb, Cl, I and M is (1 - x):1:1:x)

[0035] In an embodiment of the present invention, the white light-emitting material Pb 1-x ClI: xM is PbICl doped with metal ions (Cu 2+ , Zn 2+ or Fe 2+ ). The metal ions (Cu 2+ , Zn 2+ or Fe 2+ ) replace lead ions (Pb 2+ ) and are doped into PbICl, so that PbICl produces a white light broadband emission of self-trapped excitons, and the central peak position of the fluorescence emission peak of the self-trapped excitons is 650 - 700 nm. The Pb provided by the present invention 1-xClI:xM can achieve efficient white light emission. Constructing light-emitting devices with this white light-emitting material can minimize blue light pollution and avoid self-absorption effects. At the same time, it can overcome the problem of secondary energy loss in the traditional LED light excitation process and simplify the device structure.

[0036] An embodiment of the present invention provides a method for preparing the white light luminescent material as described above, which comprises the following steps:

[0037] S1, providing a supersaturated lead iodide solution, an MCl2 solution and a lead chloride solution; M is Cu, Zn or Fe;

[0038] S2, heating the MCl2 solution and the lead chloride solution to 60-100°C (for example, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C or 100°C, etc.); heating the supersaturated lead iodide solution to 60-90°C (for example, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C or 90°C, etc.);

[0039] S3, according to the stoichiometric ratio of each element in the chemical formula of the white light luminescent material, an MCl2 solution at a temperature of 60-100°C and a lead chloride solution at a temperature of 60-100°C are added dropwise to a supersaturated lead iodide solution at a temperature of 60-90°C, and stirred at a temperature of 60-90°C (for example, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C or 90°C, etc.) for a preset time to obtain a suspension;

[0040] S4. After the suspension is cooled to 40° C. or below, the supernatant is taken to obtain the white light luminescent material.

[0041] The present invention adopts a solvothermal method to prepare metal ion-doped PbICl, wherein metal ions replace Pb ions and are doped into PbICl, so that PbICl generates white light broadband emission of self-trapped excitons, and the central peak position of the fluorescence emission peak of the self-trapped excitons is 660nm. 1-x ClI:xM can achieve efficient white light emission. Using this white light luminescent material to construct a light emitting device can minimize blue light pollution and avoid self-absorption effects. At the same time, it can overcome the problem of secondary energy loss in the traditional LED light excitation process and simplify the device structure. The preparation method provided by the present invention is simple to make, the raw material cost used is low, and the repeatability is strong.

[0042] In this embodiment, the purpose of heating each solution before mixing is to ensure that when different solutions are mixed, the solution temperature does not change significantly (because local temperature changes will affect the reaction rate).

[0043] In step S1, in some embodiments, the method for preparing the supersaturated lead iodide solution comprises the following steps:

[0044] Lead iodide powder was dispersed in water at a ratio of 0.2 mmol:50 mL to form a supersaturated lead iodide solution.

[0045] In some embodiments, the concentration of the MCl2 solution is 0-0.04mmol / mL (for example, it can be 0.01mmol / mL, 0.02mmol / mL, 0.03mmol / mL or 0.04mmol / mL, etc.), and the concentration of the MCl2 solution is not 0mmol / mL; the concentration of the lead chloride solution is 0.006-0.02mmol / mL (for example, it can be 0.006mmol / mL, 0.01mmol / mL, 0.015mmol / mL or 0.02mmol / mL, etc.).

[0046] In step S2, in some embodiments, under stirring conditions, the MCl2 solution and the lead chloride solution are heated to 60-100°C, respectively, and stirred at 60-100°C for 0.5-1.5h, for example, 0.5h, 1h or 1.5h.

[0047] In step S3, in some embodiments, the preset time is 20 minutes to 2 hours (for example, it can be 20 minutes, 1 hour, 1.5 hours or 2 hours, etc.).

[0048] In step S4, in some embodiments, after the suspension is cooled to 40° C. or below, the supernatant is taken to obtain the white light luminescent material, which specifically includes:

[0049] S41, after the suspension is cooled to 40°C or below, take the supernatant;

[0050] S42, placing the supernatant on the surface of a substrate, and after drying, obtaining the white light luminescent material on the surface of the substrate.

[0051] The present invention also provides an application of the white light luminescent material as described above in the present invention and / or the white light luminescent material prepared by the preparation method as described above in the present invention in a light emitting device. The white light luminescent material is used as a luminescent layer material in a light emitting device.

[0052] In some embodiments, the light emitting device is an LED.

[0053] An embodiment of the present invention further provides a light-emitting device, wherein the light-emitting device comprises the white light luminescent material described above in the embodiment of the present invention and / or the white light luminescent material prepared by the preparation method described above in the embodiment of the present invention.

[0054] An embodiment of the present invention further provides an LED, wherein the LED comprises the white light luminescent material described above in the embodiment of the present invention and / or the white light luminescent material prepared by the preparation method described above in the embodiment of the present invention.

[0055] The present invention will be further described below by means of specific examples.

[0056] Example 1

[0057] This embodiment provides a white light emitting material (Pb 0.98 ICl: 0.02Cu) preparation method, comprising the following steps:

[0058] (1) 0.2 mmol of lead iodide powder was dispersed in 50 mL of deionized water to form a supersaturated solution, i.e., solution a;

[0059] (2) Dissolve 0.1 mmol of CuCl2 powder in 10 mL of deionized water to obtain solution b;

[0060] (3) dissolving 0.1 mmol of lead chloride powder in 10 mL of deionized water to obtain solution c;

[0061] (4) placing solution b and solution c in an oil bath respectively, heating to 80° C. under stirring, and maintaining the temperature for 1 hour to obtain heated solution b and heated solution c;

[0062] (5) According to Pb 0.98 ICl: 0.02Cu stoichiometric ratio of each element, 20mL solution a was heated to 80°C, then 0.32mL heated solution b and 7.68mL heated solution c were slowly added dropwise to solution a, and the mixture was stirred and heated (80°C) continuously, and the heating was stopped after 1h to obtain suspension d;

[0063] (6) When the temperature of the suspension d is cooled to 40°C or below, take the upper clear liquid and drop it on the cleaned substrate, remove the excess deionized water, and obtain Pb on the substrate. 0.98 ICl: 0.02Cu.

[0064] Example 2

[0065] This embodiment provides a white light emitting material (Pb 0.99 The preparation method of ICl: 0.01Cu) is different from that of Example 1 only in that: in step (5), according to Pb 0.99ICl: 0.01Cu stoichiometric ratio of each element, 20mL solution a was heated to 90°C, and then 0.16mL heated solution b and 7.84mL heated solution c were slowly added dropwise to solution a, and the mixture was stirred and heated (90°C) continuously. After 1h, heating was stopped to obtain suspension d;

[0066] (6) When the temperature of the suspension d is cooled to 40°C or below, take the upper clear liquid and drop it on the cleaned substrate, remove the excess deionized water, and obtain Pb on the substrate. 0.99 ICl: 0.01Cu.

[0067] Example 3

[0068] This embodiment provides a white light emitting material (Pb 0.95 The preparation method of ICl: 0.05Cu) differs from that of Example 1 only in that:

[0069] In step (5), according to Pb 0.95 ICl: The stoichiometric ratio of each element in 0.05Cu, 20mL solution a is heated to 90°C, and then 0.8mL heated solution b and 7.2mL heated solution c are slowly added dropwise to solution a, and the mixture is continuously stirred and heated (90°C). After 1h, heating is stopped to obtain suspension d;

[0070] In step (6), when the temperature of the suspension d is cooled to 40°C or below, the upper clear liquid is taken and dropped onto the cleaned substrate, and the excess deionized water is removed to obtain Pb on the substrate. 0.95 ICl: 0.05Cu.

[0071] Example 4

[0072] This embodiment provides a white light emitting material (Pb 0.85 The preparation method of ICl:0.15Cu) differs from that of Example 1 only in that:

[0073] In step (5), according to Pb 0.85 ICl: 0.15 The stoichiometric ratio of each element in Cu, 20 mL of solution a was heated to 90 ° C, and then 2.4 mL of heated solution b and 5.6 mL of heated solution c were slowly added dropwise to solution a, and the mixture was stirred and heated (90 ° C) continuously. After 1 hour, the heating was stopped to obtain a suspension d;

[0074] In step (6), when the temperature of the suspension d is cooled to 40°C or below, the upper clear liquid is taken and dropped onto the cleaned substrate, and the excess deionized water is removed to obtain Pb on the substrate. 0.85 ICl: 0.15Cu.

[0075] Example 5

[0076] This embodiment provides a white light emitting material (Pb 0.98 The preparation method of ICl:0.02Fe) differs from that of Example 1 only in that:

[0077] In step (2), the CuCl2 is replaced by FeCl2;

[0078] In step (5), according to Pb 0.98 ICl: 0.02 Fe stoichiometric ratio of each element, 20 mL of solution a was heated to 80 ° C, and then 0.32 mL of heated solution b and 7.68 mL of heated solution c were slowly added dropwise to solution a, stirring and heating were continued, and heating was stopped after 1 hour to obtain suspension d;

[0079] In step (6), when the temperature of the suspension d is cooled to 40°C or below, the upper clear liquid is taken and dropped onto the cleaned substrate, and the excess deionized water is removed to obtain Pb on the substrate. 0.98 ICl:0.02Fe.

[0080] Example 6

[0081] This embodiment provides a white light emitting material (Pb 0.98 The preparation method of ICl: 0.02Zn) differs from that of Example 1 only in that:

[0082] In step (2), the CuCl2 is replaced by ZnCl2;

[0083] In step (5), according to Pb 0.98 The stoichiometric ratio of each element in ICl:0.02Zn, 20mL solution a is heated to 80°C, and then 0.32mL heated solution b and 7.68mL heated solution c are slowly added dropwise to solution a, stirring and heating are continued, and heating is stopped after 1 hour to obtain suspension d;

[0084] In step (6), when the temperature of the suspension d is cooled to 40°C or below, the upper clear liquid is taken and dropped onto the cleaned substrate, and the excess deionized water is removed to obtain Pb on the substrate. 0.98 ICl:0.02Zn.

[0085] Comparative Example 1

[0086] This embodiment provides a method for preparing PbIC1, comprising the following steps:

[0087] (1) 0.2 mmol of lead iodide powder was dispersed in 50 mL of deionized water to form a supersaturated solution, i.e., solution a;

[0088] (2) dissolving 0.1 mmol of lead chloride powder in 10 mL of deionized water to obtain solution c;

[0089] (4) placing solution c in an oil bath and heating to 80° C. under stirring, and maintaining the temperature for 1 h to obtain heated solution c;

[0090] (5) According to the stoichiometric ratio of each element in PbICl, 20 mL of solution a was heated to 80 °C, and then 10 mL of the heated solution c was slowly added dropwise to solution a, and the mixture was continuously stirred and heated (80 °C). After 1 h, the heating was stopped to obtain a suspension d.

[0091] (6) When the temperature of the suspension d is cooled to 40°C or below, the upper clear liquid is taken and dropped onto a clean substrate, and the excess deionized water is removed to obtain PbICl on the substrate.

[0092] At the same time, the temperature in step (5) was changed to 60° C. and 100° C., respectively, to obtain PbICl prepared at different temperatures.

[0093] test:

[0094] The optical microscope images of PbICl prepared at different temperatures in Comparative Example 1 are as follows: Figure 1 As shown, it has a nanowire-like morphology. The microscopic morphology of the white light luminescent materials in Examples 1 to 6 is similar to the morphology of PbICl in Comparative Example 1, both of which are nanowire-like morphologies.

[0095] The Raman spectrum of PbICl prepared at 80°C in Comparative Example 1 is as follows: Figure 2 As shown, it is confirmed to be PbICl. The white light emitting materials in Examples 1 to 6 have similar Raman spectra to that of PbICl in Comparative Example 1.

[0096] Pb in Example 1 0.98 The results of scanning electron microscope (SEM) and energy spectrum (EDS) test of ICl:0.02Cu are shown in the figure below. Figure 3 As shown, it can be explained that Cu is effectively doped.

[0097] PbIC1 in Comparative Example 1 (prepared at 90°C in step (5)), Pb 0.99 ICl: 0.01Cu, Pb in Example 3 0.95 ICl: 0.05Cu, Pb in Example 4 0.85 The room temperature fluorescence spectrum of ICl:0.15Cu is shown in Figure 4As shown, the white light luminescence intensity of PbICl is very low, while the doping of copper ions can improve the luminescence intensity, and with the increase of the copper ion doping amount, the luminescence intensity first increases and then decreases.

[0098] Pb in Example 1 0.98 ICl: 0.02Cu, Pb in Example 5 0.98 ICl: 0.02Fe, Pb in Example 6 0.98 The room temperature fluorescence spectrum of ICl:0.02Zn is shown in the figure Figure 5 As shown. It can be seen that the doping of copper ions, iron ions and zinc ions can improve the white light luminescence intensity of PbICl.

[0099] Pb in Example 3 0.95 The fluorescence spectra of ICl:0.05Cu at different temperatures are shown in Figure 6 As shown, as the temperature increases, the luminous intensity decreases.

[0100] In summary, in the present invention, the white light luminescent material Pb 1-x ClI: xM is a metal ion (Cu 2+ 、Zn 2+ or Fe 2+ ) doped PbICl, metal ions replace Pb ions and are doped into PbICl, so that PbICl produces white light broadband emission of self-trapped excitons, and the central peak position of the fluorescence emission peak of the self-trapped excitons is 660nm. The Pb 1-x ClI:xM can achieve efficient white light emission. Constructing light-emitting devices with this white light-emitting material can minimize blue light pollution and avoid self-absorption effects. At the same time, it can overcome the problem of secondary energy loss in the traditional LED light excitation process and simplify the device structure.

[0101] It should be understood that the application of the present invention is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A white light luminescent material, characterized in that: The chemical formula of the white light emitting material is Pb 1-x ClI:xM, where 0 < x ≤ 0.2 and M is Cu, Zn or Fe.

2. A method for preparing the white light luminescent material according to claim 1, characterized in that: The steps include: Providing a supersaturated lead iodide solution, an MCl2 solution and a lead chloride solution; M is Cu, Zn or Fe; Heat the MCl2 solution and the lead chloride solution to 60-100°C respectively; Heat the supersaturated lead iodide solution to 60-90°C; According to the stoichiometric ratio of each element in the chemical formula of the white light luminescent material, an MCl2 solution at a temperature of 60-100° C. and a lead chloride solution at a temperature of 60-100° C. are added dropwise to a supersaturated lead iodide solution at a temperature of 60-90° C., and stirred at a temperature of 60-90° C. for a preset time to obtain a suspension; After the suspension is cooled to 40° C. or below, the supernatant is taken to obtain the white light luminescent material.

3. The preparation method according to claim 2, characterized in that: After the suspension is cooled to 40° C. or below, the supernatant is taken to obtain the white light luminescent material, which specifically includes: After the suspension is cooled to 40°C or below, take the supernatant; The supernatant is placed on the surface of a substrate and dried to obtain the white light emitting material on the surface of the substrate.

4. The preparation method according to claim 2, characterized in that: The concentration of the MCl2 solution is 0-0.04 mmol / mL, and the concentration of the MCl2 solution is not 0 mmol / mL; the concentration of the lead chloride solution is 0.006-0.02 mmol / mL.

5. The preparation method according to claim 2, characterized in that: The preparation method of the lead iodide supersaturated solution comprises the following steps: Lead iodide powder was dispersed in water at a ratio of 0.2 mmol:50 mL to form a supersaturated lead iodide solution.

6. The preparation method according to claim 2, characterized in that: Under stirring conditions, the MCl2 solution and the lead chloride solution are heated to 60-100°C respectively, and stirred at 60-100°C for 0.5-1.5h respectively.

7. The preparation method according to claim 2, characterized in that: The preset time is 20min-2h.

8. Use of the white light luminescent material according to claim 1 and / or the white light luminescent material prepared by the preparation method according to any one of claims 2 to 7 in a light emitting device.

9. The use according to claim 8, characterized in that: The light emitting device is a light emitting diode.

10. A light emitting device, characterized in that: The light-emitting device comprises the white light luminescent material according to claim 1 and / or the white light luminescent material prepared by the preparation method according to any one of claims 2-7.

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