Eu (II)-doped double perovskite red fluorescent powder as well as preparation method and application thereof

Abstract

The invention relates to Eu (II) doped double perovskite red fluorescent powder as well as a preparation method and application thereof, and belongs to the technical field of inorganic luminescent materials. According to the red fluorescent powder capable of being excited by the blue light, disclosed by the invention, high-performance red light emission is realized by doping Eu < 2 + > with an oxide Sr2B1-xB 'O6 (wherein B is lutetium (Lu), B' is tantalum (Ta) or niobium (Nb), and x is greater than or equal to 0.01 and less than or equal to 0.10 as a matrix). The novel red fluorescent powder can be applied to white light LED illumination. When the fluorescent powder is used in combination with green light or yellow light fluorescent powder in the prior art, efficient white light is expected to be realized under the excitation of blue light, so that the color rendering performance of a white light LED is absolutely improved.

Description

Technical Field

[0001] The invention belongs to the technical field of inorganic luminescent materials and relates to Eu(II)-doped double perovskite red phosphor and a preparation method and application thereof. Background Art

[0002] Due to the continuous improvement of light-emitting diodes (LEDs), especially InGaN chips in the 450-460nm band have become the most efficient chips, so the development of phosphors that can be excited by blue light is an effective way to achieve high-performance devices. In particular, rare earth-doped luminescent materials have become a hot topic in the research field. White light LEDs (WLEDs) are known as the fourth generation of green lighting sources due to their wide application potential in the field of solid-state lighting. At present, industrialized light-conversion white light LEDs usually use blue light InGaN chips to excite YAG:Ce 3+ Yellow phosphor. Although this method is simple in principle and has high luminous efficiency, it has been applied in many fields. However, the lack of red light emission spectrum leads to a low color rendering index, which usually makes WLEDs have a low color rendering index (R a <80) and high correlated color temperature (CCT>4500K), which is limited in some fields with high requirements for color temperature and color rendering, such as artistic lighting and medical lighting. In order to meet the requirements of high-quality lighting, WLEDs must have a high color rendering index (Ra>80), high lumen efficiency (>90lm / W) and low correlated color temperature (2700~4500K).

[0003] There are two main ways to make white light LEDs: one is to combine blue light LED chips with red / green phosphors, and the other is to combine blue light LED chips with yellow phosphors. When considering aspects such as device cost, ease of implementation, and light color quality, people usually choose these two methods to achieve white light LED luminescence. At present, existing white light LEDs use red light phosphor systems, including sulfide systems, silicon-based nitride (oxygen) systems, and red light phosphors such as silicates, borates, phosphates, and tantalates. However, the stability and resistance to ultraviolet radiation of the sulfide system are poor, which makes the service life of white light LEDs short. At the same time, this type of phosphor is sensitive to humidity and has poor stability. The preparation process of silicon-based nitride (oxygen) phosphors requires harsh conditions such as high temperature and high pressure, which increases costs and safety hazards. The red light phosphors of silicate, borate, phosphate, and tantalate systems perform better in terms of chemical stability and thermal stability, but the color rendering index of the packaged finished products is generally low. In addition, currently commercial red phosphors, such as Mn 4+ Fluoride-doped red phosphor has the advantages of narrow emission spectrum and high color purity, but a large amount of corrosive hydrofluoric acid is required during the synthesis process and it has poor stability in high humidity environments.

[0004] In summary, in the field of solid-state lighting, manufacturing high-quality WLED (R a The current solution for the white light LED (CCT>80, CCT<4500K) relies on red emitting phosphors. Therefore, the present invention aims to provide a new type of red phosphor that can be excited by blue light and has high efficiency to fill the vacancy of the red light band in white light LEDs, extend the service life of white light LEDs, and improve their color rendering performance.

[0005] In recent years, domestic and foreign research on Eu 2+ Experimental and theoretical research on red light-activated materials has made progress. In the early stage, it was mainly focused on sulfides, such as CaS:Eu 2+ and SrS:Eu 2+ , both emit red light under blue light (430-500nm) excitation, and sulfides have become the focus of research due to their rich crystal structure and regulation potential. For example, Professor Guo Chongfeng of Northwestern University used a high-temperature solid-phase reaction method to improve CaS:Eu in a CO reduction atmosphere. 2+ The luminous efficiency of LED devices is low in color temperature and high in color rendering. In 2000, Ba2Si5N8:Eu was developed by Professor W.Schnick of Germany. 2+ Red phosphors have opened the door to the exploration of nitride phosphors. As research deepens, nitride red phosphors gradually emerge. In 2006, Professor HTHintzen of the Netherlands and others prepared M2Si5N8:Eu with a main emission peak at 645nm. 2+ (M=Ca, Sr, Ba) red phosphor can be effectively excited by near-ultraviolet light to blue light, and this wavelength range can fully match the output wavelength of blue light LED chips. At the same time, Professor Xie Rongjun of Xiamen University prepared a highly efficient Sr2Si5N8:Eu by replacing the synthetic raw materials. 2+ Red phosphor. With M2Si5N8:Eu 2+ The successful application of phosphors, H.Yamamoto and other research teams have made a key breakthrough and successfully prepared CaAlSiN3:Eu with high thermal quenching resistance and high efficiency. 2+ Red phosphor. Therefore, the current CaAlSiN3:Eu 2+ and M2Si5N8:Eu 2+ Red phosphor has become the main choice for white light LEDs. In 2014, German Professor Pust and others reported a new narrow-band red phosphor SrLiAl3N4:Eu 2+ and Ca[LiAl3N4]:Eu 2+ , exhibits narrow-band red light emission characteristics under blue light excitation, improving the color rendering of LED devices. The above research has played a key role in improving the efficiency and color quality of LEDs. Nitride red phosphors are superior to sulfide red phosphors in terms of physical and chemical stability. However, the preparation of Eu2+ The requirements for doping nitride red light materials are quite challenging, and the available material systems are relatively limited. In addition, the excitation spectrum of nitrides overlaps seriously with the emission spectrum of YAG:Ce, and the reabsorption effect reduces the lumen efficiency of white light LED devices. 2+ -N 3- and Eu 2+ -S 2- Covalent bond, weak Eu in oxide 2 + -O 2- Covalent bonds will cause a smaller displacement of the center of mass, which can effectively avoid the spectral reabsorption effect. In addition, oxide phosphors have the advantages of adjustable structure, low preparation cost and chemical stability. 2+ Activated oxide red light materials have become a new target for scientific researchers.

[0006] In the early days, Sato et al. 2+ Doping into Ca2SiO4 can achieve red light emission at 650nm. In recent years, Professor Xia Zhiguo of South China University of Technology has reported a series of (K / Rb)3(Y / Lu)Si2O7:Eu 2+ Oxide-based red-near infrared phosphors represented by. Among them, combined with Rb3LuSi2O7:Eu 2+ The white light LED produced has a color rendering index of R a Up to 93, color temperature T c As low as 4013K. Recently, Hu Tao and others from Wuyi University developed a new multifunctional oxide CaLuGaO4:Eu 2+ Red phosphor, combined with the material to make the device has a low color temperature (3917K), high color rendering index (R a =92.2) and excellent luminous efficacy (110lm / W). The above-mentioned materials are crucial to improving the lighting quality of LEDs, but their external quantum efficiency and luminescence stability are far from commercial standards. The structure of Sr2LuTaO6 was reported in a paper (10.1016 / j.ceramint.2019.05.053). The researchers in this paper conducted a detailed study of the matrix structure, which laid the foundation for the development of luminescent materials. It has been reported that trivalent rare earth ion doping Sr2LuTaO6 can achieve luminescence, such as Sm 3+ (https: / / doi.org / 10.1016 / j.jlumin.2021.117901; https: / / doi.org / 10.1007 / s10854-019-01260-w). The present invention is based on the research of such literature.

[0007] Currently, Eu can be excited by blue light. 2+The types of activated oxide red light materials are limited, and there is an urgent need to develop high-efficiency, high-thermal-stability oxide-based red light materials to meet the needs of high-quality lighting. Summary of the invention

[0008] In view of this, one of the objects of the present invention is to provide a Eu(II)-doped double perovskite red phosphor; a second object of the present invention is to provide a method for preparing a Eu(II)-doped double perovskite red phosphor; a third object of the present invention is to provide an application of the Eu(II)-doped double perovskite red phosphor as a red fluorescent material; a fourth object of the present invention is to provide a white light LED light-emitting device.

[0009] In order to achieve the above object, the present invention provides the following technical solutions:

[0010] 1. Eu(II)-doped double perovskite red phosphor, the double perovskite red phosphor is Eu(II) (Eu 2+ ) doped red phosphor, wherein the chemical composition of the red phosphor is Sr2B 1-x B'O6, wherein B is lutetium (Lu), B' is tantalum (Ta) or niobium (Nb), and the Sr2B 1-x B and doped Eu in B'O6 2+ The molar ratio is (1-x):x, where 0.01≤x≤0.10.

[0011] Preferably, the double perovskite red phosphor is Eu(II) (Eu 2+ ) is the luminous center.

[0012] 2. A method for preparing the above-mentioned Eu(II)-doped double perovskite red phosphor, the preparation method comprising the following steps:

[0013] (1) According to the general formula Sr2B 1-x B'O6:xEu 2+ Accurately weigh a strontium source, a B source, a B' source and a europium source as raw materials in a stoichiometric ratio, wherein 0.01≤x≤0.10, add a flux, and grind and mix them thoroughly to obtain a raw material mixture;

[0014] (2) placing the raw material mixture obtained in step (1) in a reducing atmosphere and calcining at 1100-1450° C. for 4-10 hours to obtain the product.

[0015] Preferably, in step (1), the strontium source is at least one of strontium carbonate or other compounds that can be converted into strontium oxide;

[0016] In step (1), the B source is at least one of lutetium trioxide or other compounds that can be converted into lutetium trioxide;

[0017] In step (1), the europium source is at least one of europium trioxide or other compounds that can be converted into europium trioxide.

[0018] Preferably, in step (1), the flux is at least one of boron trioxide or compounds that can be converted into boron trioxide, and the mass of the flux is 0.1% to 10% mmol of the total amount of the mixture, wherein the mixture is formed by mixing a strontium source, a B source, a B' source and a flux.

[0019] Preferably, in step (1), the B' source is a tantalum source or a niobium source;

[0020] The tantalum source is at least one of tantalum pentoxide or a compound that can be converted into tantalum pentoxide;

[0021] The niobium source is at least one of niobium pentoxide and a compound that can be converted into niobium pentoxide.

[0022] Preferably, the reducing atmosphere is a CO atmosphere.

[0023] 3. Application of the above Eu(II)-doped double perovskite red phosphor as a red fluorescent material.

[0024] 4. A white light LED light-emitting device, comprising an InGaN semiconductor chip, a green fluorescent material and the above-mentioned Eu(II)-doped double perovskite red fluorescent powder.

[0025] Preferably, the peak wavelength of the light emission of the InGaN semiconductor chip is 440-460 nm, and the chemical composition of the green phosphor is Ba2SiO4:Eu 2+ ;

[0026] The green fluorescent material in the white light LED light-emitting device and the Eu(II)-doped double perovskite red fluorescent powder are uniformly dispersed in UV quick-drying resin glue and covered on the surface of the InGaN semiconductor chip by coating or dispensing.

[0027] The beneficial effects of the present invention are as follows: the present invention discloses a Eu(II)-doped double perovskite red phosphor, which is mainly composed of Eu 2+ Doped red phosphor (chemical composition is Sr2B 1-x B'O6:xEu 2+ , where B is lutetium (Lu), B' is tantalum (Ta) or niobium (Nb), where Eu 2+ The doping amount is 0.01≤x≤0.10). The present invention dopes the red phosphor with Eu 2+ After that, a strange luminescence feature is produced, which is Eu with fd parity allowed transition.2+ Doping luminescent materials, because 5d electrons are easily affected by the environment, by designing the chemical composition, changing the preparation method and the luminescent center Eu 2+ The substitution of ortho-cations can promote the electron cloud expansion effect, crystal field and electron-phonon coupling on Eu 2+ :4f 6 5 1 The electronic configuration has a significant effect on Eu 2+ The emission of Eu has great tunability, achieving unique broadband red light emission. 2+ The luminescence performance of Eu 2+ In Sr2LuTaO6, a strong red light emission phenomenon will be generated, thus satisfying the red light band missing in current white light illumination. As a red fluorescent material, it has good application prospects in white light LED lighting devices.

[0028] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0030] Figure 1 a is Sr2Lu in Example 1 0.99 TaO6:0.01Eu 2+ Phase diagram of red powdery phosphor, b is Sr2Lu 0.99 TaO6:0.01Eu 2+ Excitation and emission spectra of red phosphor;

[0031] Figure 2 a is Sr2Lu in Example 2 0.99 TaO6:0.01Eu 2+ Phase diagram of red phosphor, b is Sr2Lu in Example 2 0.99 TaO6:0.01Eu 2+ Excitation and emission spectra of red phosphor;

[0032] Figure 3 a is Sr2Lu in Example 3 0.98 TaO6:0.02Eu 2+ Phase diagram of red phosphor, b is Sr2Lu in Example 3 0.98TaO6:0.02Eu 2+ Excitation and emission spectra of red phosphor;

[0033] Figure 4 a is Sr2Lu in Example 4 0.95 NbO6:0.05Eu 2+ Phase diagram of red phosphor, b is Sr2Lu in Example 4 0.95 TaO6:0.05Eu 2+ Excitation and emission spectra of red phosphor;

[0034] Figure 5 The double perovskite red phosphor (Sr2Lu 0.99 TaO6:0.01Eu 2+ ) spectrum of the white light LED luminescent device prepared. DETAILED DESCRIPTION

[0035] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0036] Example 1

[0037] A Eu(II)-doped double perovskite red phosphor (Sr2Lu 0.99 TaO6:0.01Eu 2+ ), the specific preparation method is as follows:

[0038] Take 2mmol SrCO3, 0.5mmol Lu2O3, 0.5mmol Ta2O5, 0.01mmol Eu2O3 and 1%mmol B2O3, mix them thoroughly, place them in a high-temperature box furnace, heat them to 1400℃ in a CO atmosphere and sinter them for 6h. After cooling, take them out and grind them into powder to obtain Eu(II)-doped double perovskite red phosphor (Sr2Lu 0.99 TaO6:0.01Eu 2+ ).

[0039] The Eu(II)-doped double perovskite red phosphor (Sr2Lu 0.99 TaO6:0.01Eu 2+ ) completely corresponds to the standard card, and its phase diagram is as follows Figure 1 As shown in a, the excitation and emission spectra are Figure 1 As shown in b, by monitoring the sample at a wavelength of 620nm, a broadband excitation peak of 400 to 620nm can be obtained. By measuring the excitation spectrum of the sample at the optimal excitation wavelength of 450nm, it is clear that there is a broadband emission in the range of 560 to 800nm.

[0040] Example 2

[0041] A Eu(II)-doped double perovskite red phosphor (Sr2Lu 0.99 TaO6:0.01Eu 2+ ), the specific preparation method is as follows:

[0042] Take 2mmol SrCO3, 0.5mmol Lu2O3, 0.5mmol Ta2O5, 0.01mmol Eu2O3 and 2%mmol B2O3, mix them thoroughly, place them in a high-temperature box furnace, heat them to 1400℃ in a CO atmosphere and sinter them for 6h. After cooling, take them out and grind them into powder to obtain Eu(II)-doped double perovskite red phosphor (Sr2Lu 0.99 TaO6:0.01Eu 2+ ).

[0043] The Eu(II)-doped double perovskite red phosphor (Sr2Lu 0.99 TaO6:0.01Eu 2 + ) completely corresponds to the standard card, and its phase diagram is as follows Figure 2 As shown in a, the excitation and emission spectra are Figure 2 As shown in b, by monitoring the sample at a wavelength of 620nm, two broadband excitation peaks can be obtained. The excitation spectrum of the sample is measured at the optimal excitation wavelength of 450nm. Obviously, there is a broadband emission in the range of 560 to 800nm.

[0044] Example 3

[0045] A Eu(II)-doped double perovskite red phosphor (Sr2Lu 0.98 TaO6:0.02Eu 2+ ), the specific preparation method is as follows:

[0046] 2mmol SrCO3, 0.5mmol Lu2O3, 0.5mmol Ta2O5, 0.02mmol Eu2O3 and 2%mmol B2O3 were mixed thoroughly and placed in a high temperature box furnace. The mixture was heated to 1400℃ in a CO atmosphere and sintered for 6h. After cooling, the mixture was taken out and ground into powder to obtain Eu(II) doped double perovskite red phosphor (Sr2Lu 0.99 TaO6:0.01Eu 2+ ).

[0047] The Eu(II)-doped double perovskite red phosphor (Sr2Lu 0.99 TaO6:0.01Eu 2 + ) completely corresponds to the standard card, and its phase diagram is as follows Figure 3 As shown in a, the excitation and emission spectra are Figure 3 As shown in b, by monitoring the sample at a wavelength of 620nm, two broadband excitation peaks can be obtained. The excitation spectrum of the sample is measured at the optimal excitation wavelength of 450nm. Obviously, there is a broadband emission in the range of 560 to 800nm.

[0048] Example 4

[0049] A Eu(II)-doped double perovskite red phosphor (Sr2Lu 0.95 NbO6:0.05Eu 2+ ), the specific preparation method is as follows:

[0050] 2mmol SrCO3, 0.5mmol Lu2O3, 0.5mmol Nb2O5, 0.05mmol Eu2O3 and 1%mmol B2O3 were mixed thoroughly and placed in a high temperature box furnace. The mixture was heated to 1400℃ in a CO atmosphere and sintered for 6h. The mixture was then cooled and ground into powder to obtain Eu(II) doped double perovskite red phosphor (Sr2Lu 0.95 TaO6:0.05Eu 2+ ).

[0051] The material prepared in Example 4 above completely corresponds to the standard card, and its phase diagram is as follows: Figure 4 As shown in a, the excitation and emission spectra are Figure 4 As shown in b, by monitoring the sample at a wavelength of 620nm, two broadband excitation peaks can be obtained. The excitation spectrum of the sample is measured at the optimal excitation wavelength of 450nm. Obviously, there is a broadband emission in the range of 560 to 800nm.

[0052] Example 5

[0053] A white light LED luminescent device includes a packaging substrate, an InGaN semiconductor chip, a UV quick-drying resin adhesive, and two phosphors (a green phosphor with a chemical composition of Ba2SiO4:Eu 2+ , and the other is the Eu(II)-doped double perovskite red phosphor prepared in Example 1 as a red fluorescent material). The two phosphors in the white light LED light-emitting device can effectively absorb the blue light emitted by the InGaN semiconductor chip and release green and red light respectively. Among them, the red phosphor uses the fluorescent material synthesized in the above Example 1, and its chemical composition formula is Sr2Lu 0.99 TaO6:0.01Eu 2+ ; The green phosphor is Ba2SiO4:Eu 2+ The two fluorescent powders are evenly dispersed in UV quick-drying resin glue, and then covered on the LED chip by coating or dispensing. Finally, the circuit connection is completed to obtain the white light LED luminous device of the present invention.

[0054] The spectrum of the white light LED luminescent device prepared above is as follows Figure 5 As shown, warm white light emission is achieved. At 20mA current, its lumen color rendering index is 70.3, lumen efficiency is 65.3lm / W, and color temperature is 3500K.

[0055] Similarly, the Eu(II)-doped double perovskite red phosphor prepared in the above Examples 2 to 4 is substituted for the red fluorescent material in the above Example 5 to prepare different white light LED light-emitting devices. After testing, they can all achieve warm white light emission. At a current of 20mA, the lumen color rendering index is 77.1-79.1, the lumen efficiency is 13-16.38lm / W, and the color temperature is 3885-5010K.

[0056] It can be seen that the Eu(II)-doped double perovskite red phosphor disclosed in the present invention is mainly composed of Eu 2+ Doped red phosphor (chemical composition is Sr2B 1-x B'O6:x, where B is lutetium (Lu), B' is tantalum (Ta) or niobium (Nb), where Eu 2+ The doping amount is 0.01≤x≤0.10). The present invention dopes the red phosphor with Eu 2+ After that, a strange luminescence feature is produced, which is Eu with fd parity allowed transition. 2+ Doping luminescent materials, because 5d electrons are easily affected by the environment, by designing the chemical composition, changing the preparation method and the luminescent center Eu 2+ The substitution of ortho-cations can promote the electron cloud expansion effect, crystal field and electron-phonon coupling on Eu 2+ :4f 6 51 The electronic configuration has a significant effect on Eu 2+ The emission of Eu has great tunability, achieving unique broadband red light emission. 2+ The luminescence performance of Eu 2+ In Sr2LuTaO6, a strong red light emission phenomenon will be generated, thus satisfying the red light band missing in current white light illumination. As a red fluorescent material, it has good application prospects in white light LED lighting devices.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. Eu(II)-doped double perovskite red phosphor, characterized in that: The double perovskite red phosphor is Eu(II) (Eu 2+ ) doped red phosphor, wherein the chemical composition of the red phosphor is Sr2B 1-x B'O6, wherein B is lutetium (Lu), B' is tantalum (Ta) or niobium (Nb), and the Sr2B 1-x B and doped Eu in B'O6 2+ The molar ratio is (1-x):x, where 0.01≤x≤0.

10.

2. The Eu(II)-doped double perovskite red phosphor according to claim 1, characterized in that: The double perovskite red phosphor is Eu(II) (Eu 2+ ) is the luminous center.

3. The method for preparing the Eu(II)-doped double perovskite red phosphor according to any one of claims 1 to 2, characterized in that: The preparation method comprises the following steps: (1) According to the general formula Sr2B 1-x B'O6:xEu 2+ Accurately weigh a strontium source, a B source, a B' source and a europium source as raw materials in a stoichiometric ratio, wherein 0.01≤x≤0.10, add a flux, and grind and mix them thoroughly to obtain a raw material mixture; (2) placing the raw material mixture obtained in step (1) in a reducing atmosphere and calcining at 1100-1450° C. for 4-10 hours to obtain the product.

4. The preparation method according to claim 3, characterized in that: In step (1), the strontium source is at least one of strontium carbonate or other compounds that can be converted into strontium oxide; In step (1), the B source is at least one of lutetium trioxide or other compounds that can be converted into lutetium trioxide; In step (1), the europium source is at least one of europium trioxide or other compounds that can be converted into europium trioxide.

5. The preparation method according to claim 3, characterized in that: In step (1), the flux is at least one of boron trioxide or compounds that can be converted into boron trioxide, and the mass of the flux is 0.1% to 10% mmol of the total amount of the mixture, wherein the mixture is formed by mixing a strontium source, a B source, a B' source and the flux.

6. The preparation method according to claim 3, characterized in that: In step (1), the B' source is a tantalum source or a niobium source; The tantalum source is at least one of tantalum pentoxide or a compound that can be converted into tantalum pentoxide; The niobium source is at least one of niobium pentoxide and a compound that can be converted into niobium pentoxide.

7. The preparation method according to claim 6, characterized in that: The reducing atmosphere is a CO atmosphere.

8. Use of the Eu(II)-doped double perovskite red phosphor according to any one of claims 1 to 2 as a red fluorescent material.

9. A white light LED lighting device, characterized in that: The white light LED light emitting device comprises an InGaN semiconductor chip, a green fluorescent material and the Eu(II)-doped double perovskite red fluorescent powder according to any one of claims 1 to 2.

10. The white light LED lighting device according to claim 9, characterized in that: The peak wavelength of the InGaN semiconductor chip is 440-460 nm, and the chemical composition of the green phosphor is Ba2SiO4:Eu 2+ ; The green fluorescent material in the white light LED light-emitting device and the Eu(II)-doped double perovskite red fluorescent powder as described in any one of claims 1 to 2 are uniformly dispersed in UV quick-drying resin glue and covered on the surface of the InGaN semiconductor chip by coating or dispensing.

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