Nitride fluorescent material and light-emitting device for semiconductor light-emitting

Abstract

The present invention discloses a nitride fluorescent material and a light-emitting device for semiconductor light-emitting. The nitride fluorescent material comprises a general chemical formula A a K b Si c D d B x N y :zR compound; A includes: one or two of La, Y, Lu, Gd, and must contain La; D includes: at least one of Ge, Sn, Ti, and must contain Ge or Ti; R includes: one or two of Ce, Eu, Tb and Dy, and must contain Ce; the nitride fluorescent material has La3Si6N 11 The same crystal structure; wherein, 2.5≤a≤3.2, 0≤b≤0.5, 5.8≤c≤6.2, 0≤d≤0.5, 0≤x≤0.5, 10.5≤y≤11.5, 0.005≤z≤0.4, and b and d are both 0 or both not 0, b+d+x>0.

Description

Technical Field

[0001] The present invention relates to the technical field of luminescent materials, and in particular to a nitride fluorescent material and a light-emitting device for semiconductor light-emitting. Background Art

[0002] High-power light emitting diodes (LEDs) have excellent characteristics such as small size, long life, high electro-optical conversion efficiency, fast response speed, energy saving, and environmental protection. They are widely used in commercial lighting, street lights, car lights, searchlights and other fields. However, when high-power LEDs and high-energy-density excitation light sources are used to excite fluorescent materials, the fluorescent materials will heat up sharply. Currently, the traditional commercial Y3Al5O 12 :Ce 3+ High-power devices made of (YAG) aluminate yellow powder generally suffer from severe color point drift, rapid lifetime degradation, and even irreversible performance degradation. In particular, when the temperature of the high-power chip reaches or exceeds 300°C, its external quantum efficiency will rapidly decay by more than 50%.

[0003] In order to obtain a high-power, high-energy-density excited light-emitting device, on the one hand, it is necessary to strengthen the heat dissipation method of the device, and on the other hand, it is necessary to seek a phosphor with higher thermal stability. The prior art has disclosed a new type of nitride phosphor Ce x M III 3-x M IV y X -III z (JP2008088362A, JP2010070773A); This nitride fluorescent material can be excited by light of about 300 to 530 nm to produce yellow light, and its thermal stability is higher than that of conventional YAG phosphors.

[0004] La3Si6N 11 :Ce 3+ Phosphors, due to their high thermal stability, offer significant advantages in high-power LED applications. However, due to their relatively demanding preparation conditions and the need to further improve their thermal stability and external quantum efficiency, they have not yet been widely adopted in high-power LEDs. Therefore, the present invention aims to develop a nitride phosphor material with a simple preparation method, high thermal stability, and high external quantum efficiency. Summary of the Invention

[0005] The purpose of the embodiment of the present invention is to provide a nitride fluorescent material and a light-emitting device for semiconductor light-emitting, through the K + ions and D 4+ ions replace the A with small ionic radius 3+ and Si 4+ ions, which causes the lattice to expand, weakens the electron cloud expansion effect, weakens the activator ion energy level splitting, realizes the spectrum blue shift, enhances the emission peak intensity, and increases the stability; makes the nitride fluorescent material have the comprehensive performance of excellent luminous efficiency, excellent packaging performance, and good reliability, and the light-emitting device made thereof has better reliability and higher light efficiency under high-power excitation; through the doping of K and D elements, or through the introduction of B, as well as through the joint introduction of K, D and B elements, the luminous intensity and thermal stability are improved, which is suitable for high-power LED devices.

[0006] In order to solve the above technical problems, the first aspect of the embodiment of the present invention provides a nitride fluorescent material for semiconductor light emitting, wherein the nitride fluorescent material comprises a general chemical formula A a K b Si c D d B x N y :zR compound;

[0007] A includes: one or two of La, Y, Lu, and Gd, and must contain La;

[0008] D includes: at least one of Ge, Sn, and Ti, and must contain Ge or Ti;

[0009] R includes: one or two of Ce, Eu, Tb and Dy, and must contain Ce;

[0010] The nitride fluorescent material has La3Si6N 11 Same crystal structure;

[0011] Among them, 2.5≤a≤3.2, 0≤b≤0.5, 5.8≤c≤6.2, 0≤d≤0.5, 0≤x≤0.5, 10.5≤y≤11.5, 0.005≤z≤0.4, and b and d are both 0 or not 0 at the same time, b+d+x>0.

[0012] Furthermore, b=0, d=0, 0.001≤x≤0.2.

[0013] Furthermore, 0.001≤b≤0.2, 0.001≤d≤0.2, x=0.

[0014] Furthermore, b / d≤1.5.

[0015] Furthermore, 0.001≤b≤0.1, 0.001≤d≤0.1, 0.001≤x≤0.1.

[0016] Furthermore, 0.001≤2b+x≤0.25.

[0017] Furthermore, (b+d) / x≥1.

[0018] Correspondingly, a second aspect of an embodiment of the present invention provides a light-emitting device including a phosphor and an excitation light source, wherein the phosphor includes the above-mentioned nitride light-emitting material.

[0019] The above technical solutions of the embodiments of the present invention have the following beneficial technical effects:

[0020] 1. Through the large ionic radius of K + ions and D 4+ ions replace the A with small ionic radius 3+ and Si 4+ Ions cause the lattice to expand, weaken the electron cloud expansion effect, weaken the activator ion energy level splitting, achieve spectral blue shift, enhance the emission peak intensity, and increase stability;

[0021] 2. By doping with K and D elements, or by introducing B, or by introducing K, D and B elements together, the luminous intensity and thermal stability are improved, which is suitable for high-power LED devices.

[0022] 3. The low melting point of K compounds can reduce the synthesis temperature of nitride fluorescent materials, which is conducive to the incorporation of K and D elements. In addition, the introduction of B element can improve the grain morphology, resulting in complete grains with uniform distribution, excellent crystallinity, and a single grain size of approximately 20μm. This significantly reduces defects, thereby reducing the thermal quenching of the fluorescent material, improving its stability, and increasing the emission peak intensity. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 1 is the XRD spectrum of Examples 1, 10, 26 and Comparative Example 1 of the nitride fluorescent material provided in the embodiments of the present invention;

[0024] Figure 2a is a scanning electron microscope image of the nitride fluorescent material of Comparative Example 1 of the present invention;

[0025] Figure 2b is a scanning electron microscope image of the nitride fluorescent material of Example 1 of the present invention;

[0026] Figure 2c is a scanning electron microscope image of the nitride fluorescent material of Example 10 of the present invention;

[0027] Figure 2d is a scanning electron microscope image of the nitride fluorescent material of Example 26 of the present invention;

[0028] Figure 3 This is a comparison chart of the thermal stability of nitride fluorescent material Example 26 and Comparative Example 1 provided in an embodiment of the present invention;

[0029] Figure 4It is a schematic diagram of the luminous intensity and emission wavelength range of the nitride fluorescent material embodiment 26 and comparative example 1 provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0030] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present invention.

[0031] Conventional commercial YAG aluminate yellow powders suffer from severe color shift, dramatic lifetime degradation, and even irreversible performance degradation under high-power excitation. New nitride phosphors offer greater thermal stability than conventional YAG phosphors, making them suitable for high-power, high-energy-density light-emitting devices. However, their brightness and packaging efficiency are currently lower than those of YAG, and their stability under high-power excitation still needs to be improved.

[0032] In order to improve the luminous brightness, packaging light efficiency and thermal stability of the new nitride fluorescent material, overcome its shortcomings in thermal stability, and make it more suitable for applications under high-power excitation light, the first aspect of the embodiment of the present invention provides a nitride fluorescent material for semiconductor light emitting, the nitride fluorescent material includes a chemical formula A a K b Si c D d B x N y :zR compound; A includes: one or two of La, Y, Lu, Gd, and must contain La; D includes: at least one of Ge, Sn, Ti, and must contain Ge or Ti; R includes: one or two of Ce, Eu, Tb and Dy, and must contain Ce; the nitride fluorescent material has La3Si6N 11 The same crystal structure; wherein, 2.5≤a≤3.2, 0≤b≤0.5, 5.8≤c≤6.2, 0≤d≤0.5, 0≤x≤0.5, 10.5≤y≤11.5, 0.005≤z≤0.4, and b and d are both 0 or both not 0, b+d+x>0.

[0033] Specifically, the nitride fluorescent material of the present invention is La3Si6N 11 The structure has a space group of P4bm. Both metal cations and silicon ions have two lattice sites. The crystal structure consists of a three-dimensional network formed by SiN4 tetrahedrons. La is mainly distributed in the gaps of the network structure. La1 and La2 form La in the rings composed of Si4N4 and Si8N8 units respectively. 2a and La4c The two ligands have a very good rigid and stable structure.

[0034] In the nitride luminescent material of the present invention, luminescent materials with different structures can be obtained by linking elements A, R, K, D and B with Si-N tetrahedron in a corner-corner or edge-edge manner. 11 The same crystal structure is achieved without introducing other impurities. In the nitride luminescent material of the present invention, the element A is selected as one or two of the trivalent rare earth elements La, Y, Lu, and Gd, and when La is required, R is selected as one or two of Ce, Eu, Tb, and Dy, and when Ce is required, it is possible to ensure the strict growth of the luminescent material lattice and obtain a high-stability luminescent material. However, the amount of the above elements introduced should be appropriate. When a≤2.5, the difference in the element ratio during the roasting process causes the inability to generate a pure phase, thereby causing the performance of the luminescent material to deteriorate. When a>3.2, the excess raw material residue also affects the generation of the pure phase of the luminescent material, and the temperature characteristics of the luminescent material will also deteriorate. Preferably, 2.5≤a≤3.2 can control the impurity phase to be as small as possible or no impurity phase, making the crystal structure of the nitride luminescent material purer, thereby giving the luminescent material better luminescence performance.

[0035] When c < 5.8 or c > 6.2, the structural instability caused by the difference in element ratio increases the probability of crystal structure distortion, making it difficult to obtain an ideal luminescent material. When 5.8 ≤ c ≤ 6.2, the luminescent material synthesized by the selected elements can be compared with La3Si6N 11 When z < 10.5 or z > 11.5, the structural instability caused by the difference in element ratio increases the probability of crystal structure distortion, making it difficult to obtain an ideal luminescent material. When 10.5 < z < 11.5, the luminescent material synthesized by the selected elements can be compared with La3Si6N 11 Moreover, for the nitride fluorescent material of the present invention, when 0≤b≤0.5, 0≤d≤0.5, 0≤x≤0.5 are satisfied, the desired La3Si6N 11 Crystal structure.

[0036] In the aforementioned nitride luminescent materials of the present invention, R ions serve as activator ions. After multiple experiments, it was found that the optimal activator concentration range is 0.005 ≤ z ≤ 0.4. When the z content exceeds 0.4, on the one hand, upon entering the lattice, the mismatch in ionic radius leads to increased structural instability and even the formation of impurities. On the other hand, too many R ions can cause concentration quenching due to the small inter-ionic spacing, resulting in a decrease in luminescence brightness as z increases.

[0037] Through a large number of experimental studies, it was found that the simple doping of D element has no effect on enhancing the luminous brightness. Only by co-doping K and D can the emission peak be significantly enhanced. + ions and D 4+ ions replace the A with small ionic radius 3+ and Si 4+ ions, causing the lattice to expand, weakening the electron cloud expansion effect, weakening the activator ion energy level splitting, achieving spectral blue shift, enhancing the emission peak intensity, and enhancing thermal stability at the same time; when simply doping D element, it is difficult to achieve effective substitution of D element for Si element, and K element needs to be doped at the same time. This is because the melting point of K compound is low, which can reduce the synthesis temperature of nitride fluorescent material, which is conducive to the simultaneous entry of K and D elements; In addition, the introduction of B element can improve the grain morphology, and can obtain complete grains with uniform distribution, excellent crystallinity, and a single grain size of about 20 μm, which significantly reduces defects, thereby reducing the thermal quenching of the fluorescent material, improving its stability, and enhancing the emission peak intensity. In summary, the nitride fluorescent material of the present invention has the comprehensive performance of excellent luminous efficiency, excellent packaging performance, and good reliability. The light-emitting device prepared has better reliability and higher light efficiency under high-power excitation.

[0038] Preferably, D is Ge, because compared with Ti and Sn, the melting point of Ge compounds is relatively low, and it is easy to react with other raw materials, which is conducive to the entry of Ge. Therefore, when D is Ge, it has better luminous intensity.

[0039] Preferably, R is Ce element. When all luminescence centers are Ce elements, the luminescence intensity and thermal stability are better.

[0040] In the first specific implementation of the embodiment of the present invention, b=0, d=0, 0.001≤x≤0.2. As a preferred implementation, b=0, d=0, 0.001≤x≤0.2. The introduction of an appropriate amount of B element can improve the grain morphology, making the nitride fluorescent material grains uniform and excellent in crystallinity. A single complete grain can be about 20μm. The excellent morphology can significantly reduce defects, thereby reducing the thermal quenching of the fluorescent material, improving its stability, and enhancing the emission peak intensity. If B 3+ When the element exceeds 0.2, because B 3+ Ions occupy Si 4+ , excess B 3+ The introduction of B will aggravate the charge imbalance, while the introduction of excessive B will produce impurities, which will ultimately affect the luminescence performance of nitride fluorescent materials. Therefore, when the B element satisfies 0.001≤x≤0.2, it has better luminescence intensity and thermal stability.

[0041] In the second embodiment of the present invention, 0.001≤b≤0.2, 0.001≤d≤0.2, x=0. As a preferred embodiment, 0.001≤b≤0.2, 0.001≤d≤0.2, x=0. That is, by using an appropriate amount of K + ions and D 4+ ions replace the A with small ionic radius 3+ and Si 4+ ions, causing the lattice to expand, weakening the electron cloud expansion effect, weakening the activator ion energy level splitting, achieving spectral blue shift, enhancing the emission peak intensity, and enhancing thermal stability; at the same time, the melting point of K compounds is low, which can reduce the synthesis temperature of nitride fluorescent materials, facilitate the entry of K and D elements, and improve the crystallinity of grains. When b>0.2 or d>0.2, due to K + ions and D 4+ The ionic radius is larger than that of the A 3+ and Si 4+ The incorporation of excessive ions with large ions radius can easily cause lattice distortion, ultimately affecting the luminescence properties of nitride fluorescent materials. Therefore, when 0.001≤b≤0.2 and 0.001≤d≤0.2 are satisfied, the luminescence intensity and stability are better.

[0042] Furthermore, b / d≤1.5. As a further preferred embodiment, b / d≤1.5, that is, the content of K element is less than or equal to 1.5 times the content of Ge element. The melting point of K compound is low, which can reduce the synthesis temperature of nitride fluorescent material, facilitate the entry of K and D elements, and improve the crystallinity of grains. When K and Ge elements with large ion radius are introduced into the nitride material of the present invention at the same time, the luminous intensity and thermal stability are improved. However, excessive introduction of K element to replace A 3+ Therefore, when the K element content and the Ge element content satisfy b / d≤1.5, the luminous intensity and thermal stability are better.

[0043] In the second embodiment of the present invention, 0.001≤b≤0.1, 0.001≤d≤0.1, 0.001≤x≤0.1. As a preferred embodiment, 0.001≤b≤0.1, 0.001≤d≤0.1, 0.001≤x≤0.1. + ions and D 4+ ions replace the A with small ionic radius 3+ and Si 4+ions, the lattice will expand significantly, the average bond length will increase, the covalent coordination of the luminescent center ions will weaken, and the electron cloud expansion effect will weaken, thereby causing the spectrum to blue shift. When the excitation light source excites the nitride fluorescent material provided by the present invention, the emission peak intensity will increase. On the other hand, after the lattice expands and the average bond length increases, the activator ion R 3+ The 5d energy level splits, which eventually leads to a blue shift in the spectrum. When the excitation light source excites the nitride fluorescent material provided by the present invention, the emission peak intensity is enhanced. The blue shift of the emission peak also means that the Stokes shift becomes smaller, and the radiationless relaxation phenomenon of the activator ion is weakened, thereby reducing the thermal quenching of the fluorescent material and improving its stability. In addition, by using an appropriate amount of small ion radius B 3+ Ion replacement of large ionic radius Si 4+ ions, K can be appropriately adjusted + ions and D 4+ The lattice distortion caused by the introduction of ions enhances the emission peak intensity. At the same time, the introduction of an appropriate amount of element B improves the grain morphology, resulting in uniform grains and excellent crystallinity in the nitride fluorescent material. A single complete grain can be approximately 20 μm in size. This excellent morphology significantly reduces defects, thereby reducing thermal quenching of the fluorescent material, improving its stability and enhancing the emission peak intensity. In other words, the simultaneous introduction of appropriate amounts of elements K, D, and B can simultaneously change the spectral peak position, luminescence intensity, thermal stability, and grain morphology, and achieves a more optimal luminescence effect when the conditions 0.001≤b≤0.1, 0.001≤d≤0.1, and 0.001≤x≤0.1 are met.

[0044] Furthermore, 0.001≤2b+x≤0.25. As a further preferred embodiment, 0.001≤2b+x≤0.25. K + Replace A 3+ , will produce a 2-fold charge imbalance, B 3+ Replace Si 4+ , will produce a charge imbalance of 1 times, so when K + Replace A 3+ and B 3+ Replace Si 4+ When 2b+x is greater than 0.25, the excess K and B elements will cause an extreme charge imbalance, seriously affecting the luminous efficiency. Therefore, the luminous efficiency is better within the range of 0.001≤2b+x≤0.25.

[0045] Furthermore, (b+d) / x≥1. As a further preferred embodiment, (b+d) / x≥1. That is, the total content of K element and D element is greater than the content of B element, because the ionic radius of K element is greater than the ionic radius of A, the ionic radius of D element is greater than the ionic radius of Si element, and the radius of B element is less than the radius of Si element. When the total content of K element and D element with large ionic radius is lower than the amount of B element with small ionic radius, the lattice expansion effect weakens and even evolves into lattice contraction, and the spectrum blue shift effect weakens, which ultimately affects the emission peak intensity. Therefore, when (b+d) / x≥1, the total content of K element and D element with large ionic radius is greater than the content of B element with small ionic radius, which has better luminous efficiency and thermal stability.

[0046] In addition, the specific preparation process of the above-mentioned nitride luminescent material is as follows:

[0047] Step (1): According to chemical formula A a K b Si c D d B x N y :zR is used for ingredient preparation, and the simple substances, nitrides, oxides or alloys of elements A, K, D and R, B2O3 or H3BO3 and Si3N4 are selected, and the corresponding raw materials are weighed and uniformly mixed according to the molar ratio expressed in the above chemical formula.

[0048] Step (2): placing the mixture obtained in step (1) into a container and calcining it at a high temperature under nitrogen or other non-oxidizing atmosphere, with the maximum sintering temperature being 1500° C. to 2000° C. and the calcining time being 5 h to 40 h.

[0049] Step (3): crushing, washing, sieving and drying the calcined product in step (2) to obtain a nitride fluorescent material.

[0050] Specifically, the nitride fluorescent material of the present invention is further described below in combination with a comparative example and several embodiments:

[0051] The testing environment and methods are as follows: XRD: EDS (X-ray energy dispersive spectrometer), accelerating voltage 15kV, probe current 70μA; SEM: SU1510 scanning electron microscope; relative brightness and peak wavelength: spectrophotometer, excitation wavelength 460nm; variable temperature quantum efficiency: QE-2100 quantum efficiency meter; packaging performance: the prepared red and yellow-green phosphors were evenly mixed into the encapsulant, and the solid-liquid mixture was coated on the blue LED chip and then dried in a 100°C oven. Package performance tests, including luminous efficacy, luminous flux, and chromaticity coordinates, were conducted using a HAAS-2000 spectroradiometer.

[0052] Comparative Example 1

[0053] According to the molecular formula La 2.85 Si6N 11 :0.15Ce Weigh the corresponding mass of LaN, Si3N4, and CeO2 raw materials, mix them evenly in a glove box isolated from water and oxygen, and bake them in a nitrogen atmosphere at 1900℃ for 10h. After the insulation is completed, turn off the power and cool with the furnace. Take out the sintered sample to obtain an intermediate, and crush, grind, remove impurities, wash, sieve, and dry the intermediate to obtain the final sample. Use a spectrophotometer to measure its photochromic properties under 460nm excitation. Its peak wavelength is about 537nm, and the relative brightness is defined as 100%. Use a QE-2100 quantum efficiency tester to test its variable temperature external quantum efficiency, that is, raise the temperature from room temperature to 250℃, and test the external quantum efficiency at different temperatures. Compared with the external quantum efficiency at room temperature (QE L ) compared to the external quantum efficiency (QE H ) is the decrease in the light efficiency of the powder at high temperature, which is measured by (QE L -QE H ) / QE L The calculated value, defined as 100%, reflects the thermal stability of the powder.

[0054] Example 1

[0055] A nitride fluorescent material with the chemical formula La 2.85 Si 5.95 B 0.05 N 10.98 :0.15Ce. The corresponding masses of LaN, Si3N4, CeO2, and H3BO3 were weighed according to the molecular formula and mixed thoroughly in a water- and oxygen-isolated glove box. The mixture was then calcined at 1900°C in a nitrogen atmosphere for 10 hours. After the heat hold, the power was turned off and the furnace was allowed to cool. The calcined sample was removed to obtain an intermediate, which was then pulverized, ground, cleaned, washed, sieved, and dried to obtain the final sample. The luminescence properties of the resulting phosphor are shown in Table 1.

[0056] Examples 2-9

[0057] Referring to the preparation method of Example 1, according to the chemical formula composition of the target compound in each example, the compound was selected in appropriate amounts for mixing, grinding, and selecting appropriate roasting conditions to obtain the corresponding nitride fluorescent material. The luminescence characteristics of the obtained phosphor are shown in Table 1.

[0058] Example 10

[0059] A nitride fluorescent material with the chemical formula La 2.8 K 0.05 Si 5.95 Ge0.05 N 10.967 :0.15Ce. The corresponding masses of LaN, Si3N4, CeO2, K2CO3, and GeO2 were weighed according to the molecular formula and mixed thoroughly in a water- and oxygen-proof glove box. The mixture was then calcined at 1900°C in a nitrogen atmosphere for 10 hours. After the heat hold, the power was turned off and the furnace was allowed to cool. The calcined sample was removed to obtain an intermediate, which was then pulverized, ground, cleaned, washed, sieved, and dried to obtain the final sample. The luminescence properties of the resulting phosphor are shown in Table 1.

[0060] Examples 11-25

[0061] Referring to the preparation method of Example 10, according to the chemical formula composition of the target compound in each example, the compound was selected in appropriate amounts for mixing, grinding, and selecting appropriate roasting conditions to obtain the corresponding nitride fluorescent material. The luminescence characteristics of the obtained phosphor are shown in Table 1.

[0062] Example 26

[0063] A nitride fluorescent material with the chemical formula La 2.8 K 0.05 Si 5.9 Ge 0.05 B 0.05 N 10.95 :0.15Ce. According to the molecular formula, the corresponding masses of LaN, Si3N4, CeO2, K2CO3, GeO2, and H3BO3 were weighed and mixed uniformly in a water- and oxygen-isolated glove box. The mixture was then calcined at 1900°C in a nitrogen atmosphere for 10 hours. After the heat hold, the power was turned off and the furnace was allowed to cool. The calcined sample was removed to obtain an intermediate, which was then pulverized, ground, cleaned, washed, sieved, and dried to obtain the final sample. The luminescence properties of the resulting phosphor are shown in Table 1.

[0064] Examples 27-42

[0065] Referring to the preparation method of Example 26, according to the chemical formula composition of the target compound in each example, the compound was selected in appropriate amounts for mixing, grinding, and selecting appropriate roasting conditions to obtain the corresponding nitride fluorescent material. The luminescence characteristics of the obtained phosphor are shown in Table 1.

[0066] Figure 1 The XRD patterns of the nitride fluorescent materials of Examples 1, 10, 26 and Comparative Example 1 according to the present invention are shown. Figure 1 It can be seen that the addition of elements such as K, Ge, and B does not cause phase change of the fluorescent material.

[0067] Figure 2a The scanning electron microscope images of the nitride fluorescent material embodiments 1, 10, 26 and comparative example 1 of the present invention are shown in FIG. Figure 2b It can be seen that after doping with K and Ge, the grain size becomes smaller and the aspect ratio becomes smaller, but the size is not uniform, and the size of a single grain is about 20-50μm; Figure 2c It can be seen that after doping with B element, the grain size becomes smaller and the grain uniformity is good. The size of a single grain is about 30μm. Figure 2d It can be seen that after doping with K, Ge and B elements, the morphology of single grains of the nitride fluorescent material has changed significantly, the crystallinity of the grains has improved, there are no obvious defects, and the grain size has become smaller and more uniform. The size of a single grain is about 20μm.

[0068] Figure 3 Comparison of thermal stability of nitride fluorescent material Example 26 and Comparative Example 1. Figure 3 It can be seen that after doping with K, Ge and B elements, the thermal stability of the nitride fluorescent material becomes better.

[0069] Figure 4 Schematic diagram of the luminous intensity and wavelength range of the emitted light of the nitride fluorescent material embodiment 26 and comparative example 1 of the present invention. Figure 4 It can be seen that the nitride fluorescent material of the present invention can emit yellow light with a wavelength of 500-780 nm and a peak wavelength of 525-545 nm. After being doped with K, Ge and B elements, the emission peak of the fluorescent material is blue-shifted and the emission intensity is increased.

[0070] Table 1

[0071]

[0072]

[0073] As can be seen from Table 1, the embodiments of the present invention use K + ions and D 4+ ions replace the A with small ionic radius 3+ and Si 4+ ions, achieving spectral blue shift, enhanced emission peak intensity, enhanced thermal stability, and reduced light efficiency attenuation. At the same time, the introduction of element B can improve the grain morphology and significantly reduce defects, thereby reducing the thermal quenching of the fluorescent material, improving its stability, and enhancing the emission peak intensity. The emission peak intensity can be increased by more than 20% (such as Examples 26, 28, 31, 33-41), and the light efficiency attenuation can be increased by about 50% (such as Examples 26, 28, 31, 33-35, 38-40). The excellent luminous intensity and thermal stability are suitable for use in high-power scenarios.

[0074] Correspondingly, a second aspect of an embodiment of the present invention provides a light-emitting device including a phosphor and an excitation light source, wherein the phosphor includes the above-mentioned nitride light-emitting material.

[0075] In the light-emitting device of the present invention, the fluorescent substance excited by the excitation light source is the unique nitride fluorescent material of the present invention. The nitride fluorescent material has high light efficiency and good thermal stability, thereby ultimately improving the light efficiency and stability of the light-emitting device.

[0076] Because the nitride phosphors of the present invention have high thermal stability, they can achieve both high luminous efficiency and high reliability. Consequently, the light-emitting devices or components incorporating them have high operating stability and a long service life, and are suitable for a variety of different needs, particularly high-power lighting and displays.

[0077] In a preferred embodiment, the light-emitting device further includes a radiation source, which includes one or more of an ultraviolet emission source, a near-ultraviolet emission source, and a blue light emission source. To further improve the luminous effect of the light-emitting device, the light-emitting device preferably also contains other phosphors, which include one or more of blue phosphors, cyan phosphors, yellow-green phosphors, red phosphors, and infrared phosphors. The use of the fluorescent material of the present invention in combination with the above-mentioned phosphors can enable the light-emitting device to emit white light with different color temperatures and rendering indices. These white light-emitting devices can be used in lighting or display fields.

[0078] Among them, other phosphors can be (Y, Gd, Lu, Tb)3(Al, Ga)50 12 :Ce, (Mg,Ca,Sr,Ba)2Si04:Eu, (Ca,Sr)3Si05:Eu, (La,Ca)3Si6N 11 :Ce,a-SiA1ON:Eu, β-SiAlON:Eu, Ca3Ca Sc204:Eu, BaAl80 13 :Eu, (Ca,Sr,Ba)Al204:Eu, (Sr,Ca,Ba)(Al,Ga,In)2S4:Eu, (Ca,Sr,Ba)3MgSi2O8:Eu / Mn, (Ca,Sr,Ba)2(Mg,Zn)Si2O7:Eu, Zn2SiO4:Mn, (Y,G d) BO3:Tb, ZnS:Cu,Cl / Al, ZnS:Ag,C1 / Al, (Sr,Ca)2Si5N8:Eu, (Li,Na,K)3ZrF7:Mn, (Li,Na,K)2(Ti,Zr)F6:Mn, (Ca,Sr,Ba)(Ti,Zr)F6:Mn,Ba 0.65 Zr 0.35 F 2.7 :Mn, (Sr,Ca)S:Eu, (Y,Gd)BO3:Eu, (Y,Gd)(V,P)O4:Eu, Y203:Eu, (Sr,Ca,Ba,Mg)5(PO4)3C1:Eu, (Ca,Sr,Ba)MgAl10 O 17 :Eu, (Ca, Sr, Ba)Si202N2:Eu, 3.5Mg0·0.5MgF2·GeO2:Mn or one or more thereof.

[0079] The light emitting device is described in detail below using a comparative example and several embodiments:

[0080] Comparative Application Example 1

[0081] A 460nm blue LED chip was used as the radiation source. 0.3g of the phosphor from Comparative Example 1, 0.005g of a nitride red phosphor with a peak wavelength of approximately 610nm, 0.3g of encapsulation glue A, and 3g of encapsulation glue B were mixed evenly and then coated on the 460nm LED chip. After curing, a white light-emitting device was obtained. The packaging properties of the lamp beads, such as color coordinates and luminous flux, were tested using a HAAS-2000 spectroradiometer from Hangzhou Yuanfang Company at a current of 60mA and a voltage of 3V. The color coordinates x and y were 0.3125, 0.3373, Ra was 71.6, the color temperature was 6460K, and the luminous flux at 60mA and 3V was defined as 100%. After 5 minutes of stable lighting at 1A and 3V, the lamp was tested for luminous flux and other performance using a Hangzhou Yuanfang HAAS-2000 spectroradiometer. Luminous flux at 1A and 3V was defined as 100%. See Table 2. Encapsulating glue A and encapsulating glue B can be conventionally used in the field.

[0082] Application Example 1

[0083] Using a 460nm blue LED chip as the radiation source, 0.3g of the phosphor of Example 26, 0.005g of a nitride red phosphor with a peak wavelength of about 610nm, 0.3g of encapsulation glue A, and 3g of encapsulation glue B were mixed evenly and coated on a 460nm LED chip. After curing, a white light emitting device was obtained. At a current of 60mA and a voltage of 3V, the HAAS-2000 spectroradiometer of Hangzhou Yuanfang Company was used to test the packaging performance of the lamp beads, such as the color coordinates and luminous flux. The color coordinates x were 0.3126, y was 0.3378, Ra was 71.8, and the color temperature was 6450K. After a current of 1A and a voltage of 3V were passed through and the lamp beads were stably lit for 5 minutes, the HAAS-2000 spectroradiometer of Hangzhou Yuanfang Company was used to test the luminous flux and other properties of the lamp beads after lighting for 5 minutes. See Table 2.

[0084] Application Examples 2 to 3

[0085] Referring to the packaging method of Application Example 1, LED devices were packaged according to respective mass ratio schemes. The packaging performances such as the scheme, color coordinates, and luminous flux can be seen in Table 2.

[0086] Table 2

[0087]

[0088] From the above, it can be seen that the LED lamp beads with similar coordinates are obtained by packaging the phosphor of the comparative example and the embodiment of the present invention with the blue light LED chip. Compared with the application comparative example, the lamp beads of each application embodiment of the present invention have increased luminous flux at 60mA, 3V and 1A, 3V, especially the luminous flux at 1A, 3V is significantly increased, that is, they are suitable for high-power lighting.

[0089] As can be seen from the above, compared with the comparative example, each embodiment of the present invention has a large ionic radius of K + ions and D 4+ ions replace the A with small ionic radius 3+ and Si 4+ ions, which causes the spectrum to blue shift, the emission peak intensity is enhanced, and the stability is improved. In addition, by using an appropriate amount of small ion radius B 3+ Ion replacement of large ionic radius Si 4+ ions, K can be appropriately adjusted + ions and D 4+ The lattice distortion caused by the introduction of ions enhances the emission peak intensity. Simultaneously, the introduction of an appropriate amount of element B improves the grain morphology, resulting in uniform grains and excellent crystallinity in the nitride phosphor material. A single, complete grain can be approximately 20μm in size. This excellent morphology significantly reduces defects, thereby reducing thermal quenching of the phosphor material, improving its stability and simultaneously enhancing the emission peak intensity. In other words, the simultaneous introduction of appropriate amounts of elements K, D, and B can simultaneously alter luminescence intensity, grain morphology, thermal stability, and packaging luminous efficiency.

[0090] The embodiment of the present invention is intended to protect a nitride fluorescent material and a light-emitting device for semiconductor light-emitting. The nitride fluorescent material includes a chemical formula A a K b Si c D d B x N y :zR compound; A includes: one or two of La, Y, Lu, Gd, and must contain La; D includes: at least one of Ge, Sn, Ti, and must contain Ge or Ti; R includes: one or two of Ce, Eu, Tb and Dy, and must contain Ce; the nitride fluorescent material has La3Si6N 11The same crystal structure; wherein, 2.5≤a≤3.2, 0≤b≤0.5, 5.8≤c≤6.2, 0≤d≤0.5, 0≤x≤0.5, 10.5≤y≤11.5, 0.005≤z≤0.4, and b and d are both 0 or both not 0, b+d+x>0.

[0091] The above technical solution has the following effects:

[0092] 1. Through the large ionic radius of K + ions and D 4+ ions replace the A with small ionic radius 3+ and Si 4+ Ions cause the lattice to expand, weaken the electron cloud expansion effect, weaken the activator ion energy level splitting, achieve spectral blue shift, enhance the emission peak intensity, and increase stability;

[0093] 2. By doping with K and D elements, or by introducing B, or by introducing K, D and B elements together, the luminous intensity and thermal stability are improved, which is suitable for high-power LED devices.

[0094] 3. The low melting point of K compounds can reduce the synthesis temperature of nitride fluorescent materials, which is conducive to the incorporation of K and D elements. In addition, the introduction of B element can improve the grain morphology, resulting in complete grains with uniform distribution, excellent crystallinity, and a single grain size of approximately 20μm. This significantly reduces defects, thereby reducing the thermal quenching of the fluorescent material, improving its stability, and increasing the emission peak intensity.

[0095] It should be understood that the above-described specific embodiments of the present invention are merely illustrative or illustrative of the principles of the present invention and do not constitute limitations of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention should be included within the scope of protection of the present invention. In addition, the appended claims are intended to cover all variations and modifications that fall within the scope and metes and bounds of the appended claims, or equivalents thereof.

Claims

1. A nitride fluorescent material for semiconductor light emission, characterized in that: The nitride fluorescent material includes a chemical formula A a K b Si c D d B x N y :zR compound; A includes: one or two of La, Y, Lu, and Gd, and must contain La; D includes: at least one of Ge, Sn, and Ti, and must contain Ge or Ti; R includes: one or two of Ce, Eu, Tb and Dy, and must contain Ce; The nitride fluorescent material has La3Si6N 11 Same crystal structure; Among them, 2.5≤a≤3.2,0 <b≤0.5,5.8≤c≤6.2,0<d≤0.5,0≤x≤0.5,10.5≤y≤11.5,0.005≤z≤0.4。 2. The nitride fluorescent material for semiconductor light emission according to claim 1, characterized in that: 0.001≤b≤0.2, 0.001≤d≤0.2, x=0.

3. The nitride fluorescent material for semiconductor light emission according to claim 2, characterized in that: b / d≤1.

5.

4. The nitride fluorescent material for semiconductor light emission according to claim 1, wherein 0.001≤b≤0.1, 0.001≤d≤0.1, 0.001≤x≤0.

1.

5. The nitride fluorescent material for semiconductor light emission according to claim 4, characterized in that: 0.001≤2b+x≤0.

25.

6. The nitride fluorescent material for semiconductor light emission according to claim 5, characterized in that: (b+d) / x≥1.

7. A light emitting device, characterized in that: It comprises a phosphor and an excitation light source, wherein the phosphor comprises the nitride luminescent material according to any one of claims 1-6.

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