CN116825932B - LED device - Google Patents

Abstract

The invention relates to an LED device, comprising an LED chip and a phosphor composition, wherein the phosphor composition comprises the following components in percentage by mass: 3-30% of blue-green phosphor; 35-70% of green phosphor; 10-50% of white phosphor; and 3-15% of red phosphor. The LED chip comprises a first chip unit and a second chip unit, wherein the peak emission wavelength range of the first chip unit is 447.5nm-455nm, and the peak emission wavelength range of the second chip unit is 395nm-410nm. The phosphor composition of the invention can provide a high color rendering index and a full-spectrum luminous effect, and has a high color rendering index under the excitation of a dual-band chip composed of a blue light LED and a purple light LED, thereby meeting the use requirements with relatively high requirements on light color parameters.

Description

LED device

Technical Field

The invention relates to the technical field of fluorescent powder materials, and in particular to an LED device.

Background Art

As a new generation of green lighting source, LED (Light-Emitting Diode) has the advantages of high luminous efficiency, energy saving and environmental protection, long life and non-toxic and environmental protection, and is widely used in lighting and backlight display. With the improvement of living standards, people have higher and higher requirements for the light quality of LED light sources, especially for special application scenarios such as art and photography that require high color reproduction, and put forward higher requirements for the high color rendering index and full spectrum of the light source.

Currently, there is a dual-band chip in the prior art that is a combination of a blue LED and a purple LED. The color rendering index after being excited by the device using the current phosphor matching scheme does not reach the optimal level, and cannot meet the use requirements of special fields that have relatively high requirements on light color parameters.

Summary of the invention

The embodiment of the present invention provides an LED device that can provide a high color rendering index and a full-spectrum luminous effect. The above technical solution is as follows:

An LED device comprises an LED chip and a phosphor composition;

The phosphor composition comprises the following components in percentage by mass: 3-30% cyan phosphor; 35-70% green phosphor; 10-50% white phosphor; 3-15% red phosphor;

The LED chip comprises a first chip unit and a second chip unit, the peak wavelength range of the light emission of the first chip unit is 447.5nm-455nm, and the peak wavelength range of the light emission of the second chip unit is 395nm-410nm;

Among them, the peak emission wavelength range of the blue-green phosphor is 480nm-500nm; the peak emission wavelength range of the green phosphor is 520nm-540nm; the peak emission wavelength range of the white phosphor is 440nm-460nm; and the peak emission wavelength range of the red phosphor is 650nm-670nm.

Preferably, the white phosphor comprises at least one of the substances shown in Chemical Formula I,

X ¹ _2-x (PO ₄ ) ₃ Cl:xEu ²⁺ Chemical formula I

In the chemical formula I, the ^X1 is selected from at least one of Ba and Sr, and the value range of x is 0.001≤x≤0.5.

Preferably, the value range of x in the chemical formula I is 0.01≤x≤0.025.

Preferably, the green phosphor comprises at least one of the substances shown in Chemical Formula II,

X ² _3-y Al ₅ O ₁₂ :y Ce ³⁺ , chemical formula II

In the chemical formula II, the ^X2 is selected from at least one of Y, Lu, and Ga, and the value range of y is 0.001≤y≤0.5.

Preferably, the ratio between x in the chemical formula I and y in the chemical formula II is 1:(1.8-2.2).

Preferably, the blue-green phosphor comprises at least one of the substances shown in Chemical Formula III,

X ³ _1-z Si ₂ O ₂ N ₂ :zEu ²⁺ , chemical formula III

In the chemical formula III, ^X3 is selected from at least one of Ba, Ca, and Sr, and the value range of z is 0.001≤z≤0.5.

Preferably, the red phosphor comprises at least one of the substances shown in Chemical Formula IV,

X ⁴ _1-m AlSiN ₃ :mEu ²⁺ Chemical formula IV

In the chemical formula IV, ^X4 is at least one of Sr and Ca, and the value range of m is 0.001≤m≤0.5.

Preferably, the peak wavelength range of the light emission of the first chip unit is 447.5nm-452.5nm, and the peak wavelength range of the light emission of the second chip unit is 400nm-410nm.

Preferably, the LED device further comprises an LED encapsulating adhesive, and the mixing mass ratio of the phosphor composition to the LED encapsulating adhesive is 1:(1.1-2.5).

Preferably, the color rendering index of the LED device is Ra≥98, and R1-R15≥93.

Preferably, the color temperature range of the LED device is 2500K-6000K.

The phosphor composition and LED device provided by the embodiments of the present invention have a wider range of luminous colors and can achieve a full-spectrum luminous effect after being excited by a dual-band chip composed of a blue light LED and a purple light LED by improving the relationship between the component substances and the component contents in the phosphor composition; in terms of color rendering index, they have a higher color rendering index and better color rendering performance, providing a more realistic and accurate color display; and they achieve a high color rendering index and a full-spectrum high-quality luminous effect while maintaining a high photoelectric conversion efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

FIG1 is a schematic structural diagram of an LED device provided in an exemplary embodiment of the present invention;

FIG2 is a light emission spectrum diagram of the LED device of Example 1 of the present invention;

FIG3 is a light emission spectrum diagram of the LED device according to Example 2 of the present invention;

FIG. 4 is a diagram showing the light emission spectrum of the LED device according to Example 3 of the present invention.

DETAILED DESCRIPTION

In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments. 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.

In the present invention, the content range, color temperature range, wavelength range and the like of the phosphor are expressed as a-b, which means that the content, color temperature or wavelength of the phosphor can be any value between a and b, including a and b.

Color Rendering Index (CRI), Correlated Color Temperature (CCT) and Chromaticity Coordinates are three important parameters that describe the color properties of light sources.

The color rendering index is an indicator that measures the ability of a light source to restore the color of an object. It is evaluated based on the difference in the color of the object under the standard light source and the light source to be tested. The color rendering index ranges from 0 to 100, and the higher the value, the more accurately the light source can restore the true color of the object.

Color temperature is a physical quantity used to describe the color appearance of a light source. It is based on the properties of a thermal radiating black body and is expressed in absolute temperature (Kelvin, K). The higher the color temperature, the closer the color of the light source is to blue (cold tones); the lower the color temperature, the closer the color of the light source is to red (warm tones). For example, the color temperature of daylight is usually between 5500K-6500K, and the color temperature of warm white is usually between 2700K-3500K.

Chromaticity coordinates are used to describe the position of the color of a light source in a chromaticity diagram. Usually based on the CIE 1931 chromaticity diagram, the (x, y) coordinates are used to determine the position in the CIE 1931 chromaticity diagram to represent the color of the light source.

LED devices play an important role in the field of modern lighting and display. In recent years, with the rapid development of science and technology, the demand for the light color quality and spectral range of LED devices has become increasingly higher. However, under the current technical conditions, the luminous effect of the phosphor combination solution after being excited by the dual-band chip of the combination of blue light LED and purple light LED is difficult to reach the optimal level, and it is even more unable to meet the requirements of high color rendering index and full spectrum in special fields.

To this end, an embodiment of the present invention provides an LED device, the LED device includes an LED chip and a phosphor composition, the phosphor composition includes the following components in mass percentage: 3-30% of blue-green phosphor; 35-70% of green phosphor; 10-50% of white phosphor; 3-15% of red phosphor;

The LED chip comprises a first chip unit and a second chip unit, the peak wavelength range of the light emission of the first chip unit is 447.5nm-455nm, and the peak wavelength range of the light emission of the second chip unit is 395nm-410nm;

Among them, the peak emission wavelength range of the blue-green phosphor is 480nm-500nm; the peak emission wavelength range of the green phosphor is 520nm-540nm; the peak emission wavelength range of the white phosphor is 440nm-460nm; and the peak emission wavelength range of the red phosphor is 650nm-670nm.

The above-mentioned blue-green phosphor, white phosphor, green phosphor and red phosphor are named mainly according to the color of the light emitted by the phosphor after being excited. The specific color depends on the material composition and structure of the phosphor, the type of doped activator, etc. For example, "blue-green phosphor" refers to a phosphor that emits blue-green light, and its peak emission wavelength is usually in the range of 480-500nm. Among them, white phosphor does not mean that the phosphor itself emits white light, but that it can emit multiple wavelengths of light under the action of an excitation light source, and after mixing, it produces a composite light close to white light. In the above-mentioned phosphor combination, the peak emission wavelength of the white phosphor is in the range of 440-460nm (blue light region), which only means that its luminous intensity in this band is the highest.

In an embodiment of the present invention, the LED chip includes a first chip unit and a second chip unit, the peak wavelength range of the first chip unit is 447.5nm-455nm, and the peak wavelength range of the second chip unit is 395nm-410nm. That is, the LED device uses a dual-band LED chip composed of a blue light LED and a purple light LED as an excitation light source. Using this dual-band LED chip as an excitation light source can more fully excite the phosphor to emit a full spectrum of light, thereby improving the luminous effect. In an embodiment of the present invention, through the mutual synergy between the blue-green phosphor, the green phosphor, the white phosphor and the red phosphor, the widest possible spectrum can be obtained from the dual-band excitation of blue light and purple light, increasing the richness of color rendering and the flexibility of color temperature control, thereby achieving white light that is closer to natural light.

In some specific embodiments, in order to ensure that the phosphor composition achieves the best luminous effect, the LED chip can select a blue light LED chip with a peak luminous wavelength range of 447.5nm-452.5nm and a purple light LED chip with a peak luminous wavelength range of 400nm-410nm.

In some specific embodiments, the white phosphor is a divalent europium-doped alkaline earth metal chlorophosphate, including at least one of the substances shown in Chemical Formula I,

X ¹ _2-x (PO ₄ ) ₃ Cl:xEu ²⁺ Chemical formula I

In the chemical formula I, the X ¹ is selected from at least one of Ba and Sr, and the value range of x is 0.001≤x≤0.5. For example, when the value of x is 0.05, the white phosphor can be (Ba, Sr) _1.95 (PO ₄ ) ₃ Cl:xEu ²⁺ . In the embodiment of the present invention, (Ba, Sr) _1.95 means that the positions of Ba and Sr in the chemical structure are interchangeable and can exist in any proportion, as long as the total molar ratio is equal to 1.95 (2-x). The subsequent similar chemical formulas are the same and will not be repeated.

In some specific embodiments, the value range of x in the chemical formula I is 0.01≤x≤0.025.

Specifically, the rare earth ion doping concentration has an important influence on the luminescence performance of the phosphor. An appropriate ion doping concentration can improve the quantum efficiency of the phosphor, that is, the luminescence efficiency. However, too high an ion doping concentration may cause concentration quenching of the phosphor, causing the luminescence efficiency to decrease. Therefore, the rare earth ion doping concentration needs to be controlled and selected to achieve the best luminescence performance.

In some specific embodiments, the green phosphor is a trivalent cerium-doped garnet compound, including at least one of the substances shown in Chemical Formula II,

X ² _3-y Al ₅ O ₁₂ :y Ce ³⁺ , chemical formula II

In the chemical formula II, the ^X2 is selected from at least one of Y, Lu, and Ga, and the value range of y is 0.001≤y≤0.5.

In some specific embodiments, the ratio between x in the chemical formula I and y in the chemical formula II is 1:(1.8-2.2).

At this ratio, the white phosphor and the green phosphor can work better together, and by precisely controlling the ratio of rare earth ion doping concentrations in different phosphors, the luminous efficiency and color rendering of the phosphor composition are optimized.

In some specific embodiments, the blue-green phosphor is a divalent europium-doped alkaline earth metal silicon oxynitride, including at least one of the substances shown in Chemical Formula III,

X ³ _1-z Si ₂ O ₂ N ₂ :zEu ²⁺ , chemical formula III

In the chemical formula III, ^X3 is selected from at least one of Ba, Ca, and Sr, and the value range of z is 0.001≤z≤0.5.

In some specific embodiments, the red phosphor is divalent europium-doped alkaline earth metal silicon aluminum nitride including at least one of the substances shown in Chemical Formula IV,

X ⁴ _1-m AlSiN ₃ :mEu ²⁺ Chemical formula IV

In the chemical formula IV, ^X4 is at least one of Sr and Ca, and the value range of m is 0.001≤m≤0.5.

In some specific embodiments, the phosphor composition includes the following components in percentage by mass:

(Ba,Sr) _2-x (PO ₄ ) ₃ Cl:xEu ²⁺ 10-50%; (Y, Lu, Ga) _3-y Al ₅ O ₁₂ : yCe ³⁺ 35-70%;

(Ba,Ca,Sr) _1-z Si ₂ O ₂ N ₂ :zEu ²⁺ 3-30%; (Sr,Ca) _1-m AlSiN ₃ :mEu ²⁺ 3-15%.

In some specific embodiments, the phosphor composition includes the following components in percentage by mass:

(Ba,Sr) _2-x (PO ₄ ) ₃ Cl:xEu ²⁺ 20-50%; (Y, Lu, Ga) _3-y Al ₅ O ₁₂ : yCe ³⁺ 35-50%;

(Ba,Ca,Sr) _1-z Si ₂ O ₂ N ₂ :zEu ²⁺ 3-20%; (Sr,Ca) _1-m AlSiN ₃ :mEu ²⁺ 5-10%.

In an embodiment of the present invention, europium-doped alkaline earth metal silicon oxynitride, cerium-doped garnet compound, europium-doped alkaline earth metal chlorophosphate and alkaline earth metal silicon aluminum nitride are used as phosphors. These compounds have good chemical stability and physical stability, and can effectively improve the thermal stability and light stability of the phosphors and extend their service life. Europium-doped alkaline earth metal chlorophosphate has high luminous efficiency. Its own luminous wavelength is located at 440-460nm, located in the blue region of the visible spectrum, can effectively convert the blue light emitted by the LED chip, and increase the width of the overall spectrum, which helps to achieve efficient, full-spectrum luminous effects. Structurally, europium-doped alkaline earth metal chlorophosphate phosphors and cerium-doped garnet compounds have good spectral matching, and they can form a synergistic effect to improve the uniformity and continuity of the overall spectrum during spectral superposition and light energy conversion. The embodiment of the present invention improves the relationship between the component substances and the component contents in the phosphor composition, and realizes a full-spectrum luminescence effect after being excited by a dual-band chip composed of a blue light LED and a purple light LED. At the same time, it can also achieve a high color rendering index of Ra≥98, R1-R15≥93, and a high R12 index, thereby meeting the high demands in special fields.

Next, please refer to FIG. 1, which is an LED device provided by an exemplary embodiment of the present invention. As shown in FIG. 1, the LED device includes a phosphor mixture 1, a bracket 2, an LED chip 3, and a bonding gold wire 4. The LED chip 3 is composed of two electroluminescent semiconductor material chips, which emit blue light and purple light respectively; the LED chip 3 is fixed on the bracket 2 and connected to the circuit board through the bonding gold wire 4. The LED chip 3 is a dual-band LED chip composed of a blue light LED and a purple light LED. When the LED chip is powered on, it will emit blue light and purple light at the same time. The combination of these two lights excites the phosphor mixture to emit light, thereby forming the required mixed light.

In some specific embodiments, the phosphor mixture 1 is a mixture of phosphor and LED packaging glue, wherein the phosphor is any phosphor composition provided in the above-mentioned embodiments of the present invention; the LED packaging glue can be organic silicone for LED packaging, which mainly functions to protect the LED chip, and also undertakes the tasks of dispersing the phosphor and transmitting light.

In some specific embodiments, when the proportion of LED encapsulation glue is increased, the relative concentration of phosphor will decrease, which will cause the light intensity emitted by the phosphor to decrease, thereby increasing the color temperature of the LED light source, that is, it tends to be cold. On the contrary, if the proportion of encapsulation glue is reduced, the concentration of phosphor will be relatively increased, which will increase the light intensity emitted by the phosphor and reduce the color temperature of the LED light source, that is, it tends to be warm. Therefore, in addition to adjusting the formula of the phosphor composition, adjusting the mixing ratio of the phosphor composition and the LED encapsulation glue can also achieve the regulation of the color temperature of the LED light source. The mixing mass ratio relationship between the phosphor composition and the LED encapsulation glue described in the embodiment of the present invention is 1: (1.1-2.5). The LED device adopts the above-mentioned phosphor composition to meet the diverse color temperature requirements, and the color temperature range can reach 2500K-6000K, which helps to achieve a wider range of application scenarios.

The LED device adopts the above-mentioned phosphor composition. Under the excitation of the above-mentioned dual-band LED chip composed of a blue light LED and a purple light LED, it can effectively improve the color rendering performance and the breadth of the spectrum coverage. The light emission covers the full spectrum range, the color rendering index Ra≥98, R1-R15≥93, and has a higher R12 index. It can achieve excellent light-emitting performance and stability, and meet diverse lighting and display needs.

The technical solution of the present invention will be described below in conjunction with specific embodiments. The raw materials used in the following embodiments are all from common commercially available products, and the devices or equipment used are all purchased from conventional market sales channels.

Example 1

Embodiment 1 provides an LED device, which is prepared by the following steps:

A dual-band LED chip composed of a blue LED with a peak wavelength range of 447.5nm-452.5nm and a purple LED with a peak wavelength range of 400nm-410nm is selected as an excitation light source; the LED chip is cured into the bracket cup with white glue, and the positive and negative electrodes of the LED chip are respectively connected to the positive and negative electrodes of the bracket cup through gold wire bonding; the phosphor composition and the LED packaging glue are mixed in a mass ratio of 1:2.44 to obtain a phosphor mixture, and the phosphor mixture is evenly filled in the bracket cup fixed with the LED chip, so as to obtain the LED device. Wherein, the phosphor composition includes the following components in mass percentage:

Ca _0.99 Si ₂ O ₂ N ₂ :0.01Eu ²⁺ (blue-green phosphor) 5%, with a peak emission wavelength of 493nm;

Lu _2.96 Al ₅ O ₁₂ :0.04Ce ³⁺ (green phosphor) 44%, its emission peak wavelength is 530nm;

(Ba,Sr) _1.98 (PO ₄ ) ₃ Cl:0.02Eu ²⁺ (white phosphor) 44%, its emission peak wavelength is 451nm;

(Sr,Ca) _0.98 AlSiN ₃ :0.02Eu ²⁺ (red phosphor) 7%, with a peak emission wavelength of 660nm.

Example 2

Example 2 provides an LED device, which differs from Example 1 in that the mixing mass ratio of the phosphor composition to the LED encapsulation adhesive in Example 2 is 1:1.7.

The phosphor composition in Example 2 includes the following components in percentage by mass:

Ca _0.99 Si ₂ O ₂ N ₂ :0.01Eu ²⁺ (blue-green phosphor) 18%, with a peak emission wavelength of 493nm;

Lu _2.96 Al ₅ O ₁₂ :0.04Ce ³⁺ (green phosphor) 47%, its emission peak wavelength is 530nm;

(Ba,Sr) _1.98 (PO ₄ ) ₃ Cl:0.02Eu ²⁺ (white phosphor) 26%, its emission peak wavelength is 451nm;

(Sr,Ca) _0.98 AlSiN ₃ :0.02Eu ²⁺ (red phosphor) 9%, with a peak emission wavelength of 660nm.

Example 3

Example 3 provides an LED device, which differs from Example 1 in that the mixing mass ratio of the phosphor composition to the LED encapsulation adhesive in Example 3 is 1:1.2.

The phosphor composition in Example 3 includes the following components in percentage by mass:

Ca _0.99 Si ₂ O ₂ N ₂ :0.01Eu ²⁺ (blue-green phosphor) 14%, with a peak emission wavelength of 493nm;

Lu _2.96 Al ₅ O ₁₂ :0.04Ce ³⁺ (green phosphor) 40%, its emission peak wavelength is 530nm;

(Ba,Sr) _1.98 (PO ₄ ) ₃ Cl:0.02Eu ²⁺ (white phosphor) 40%, its emission peak wavelength is 451nm;

(Sr,Ca) _0.98 AlSiN ₃ :0.02Eu ²⁺ (red phosphor) 6%, with a peak emission wavelength of 660nm.

Embodiment 4 provides an LED device, which differs from Embodiment 1 in that the doping concentration of the rare earth ions in each component of the phosphor composition is different; the phosphor composition in Embodiment 4 includes the following components in percentage by mass:

Ca _0.99 Si ₂ O ₂ N ₂ :0.01Eu ²⁺ (blue-green phosphor) 5%, with a peak emission wavelength of 493nm;

Lu _2.96 Al ₅ O ₁₂ :0.04Ce ³⁺ (green phosphor) 44%, its emission peak wavelength is 530nm;

(Ba,Sr) _1.99 (PO ₄ ) ₃ Cl:0.01Eu ²⁺ (white phosphor) 44%, its emission peak wavelength is 451nm;

(Sr,Ca) _0.98 AlSiN ₃ :0.02Eu ²⁺ (red phosphor) 7%, with a peak emission wavelength of 660nm.

Embodiment 5 provides an LED device, which differs from Embodiment 1 in that the doping concentration of the rare earth ions in each component of the phosphor composition is different; the phosphor composition in Embodiment 5 includes the following components in percentage by mass:

Ca _0.99 Si ₂ O ₂ N ₂ :0.01Eu ²⁺ (blue-green phosphor) 5%, with a peak emission wavelength of 493nm;

Lu _2.98 Al ₅ O ₁₂ :0.02Ce ³⁺ (green phosphor) 44%, its emission peak wavelength is 530nm;

(Ba,Sr) _1.99 (PO ₄ ) ₃ Cl:0.01Eu ²⁺ (white phosphor) 44%, its emission peak wavelength is 451nm;

(Sr,Ca) _0.98 AlSiN ₃ :0.02Eu ²⁺ (red phosphor) 7%, with a peak emission wavelength of 660nm.

Embodiment 6 provides an LED device, which is different from Embodiment 1 in that the material of the green phosphor in the phosphor composition is different; the phosphor composition in Embodiment 6 includes the following components in percentage by mass:

Ca _0.99 Si ₂ O ₂ N ₂ :0.01Eu ²⁺ (blue-green phosphor) 5%, with a peak emission wavelength of 493nm;

Sr _1.96 SiO ₄ :0.04Eu ³⁺ (green phosphor) 44%, its emission peak wavelength is 530nm;

(Ba,Sr) _1.98 (PO ₄ ) ₃ Cl:0.02Eu ²⁺ (white phosphor) 44%, its emission peak wavelength is 451nm;

(Sr,Ca) _0.98 AlSiN ₃ :0.02Eu ²⁺ (red phosphor) 7%, with a peak emission wavelength of 660nm.

Comparative Example 1

Comparative Example 1 provides an LED device, which is different from Example 1 in that the content of components of the phosphor composition is different (white phosphor is not included); the phosphor composition in Comparative Example 1 includes the following components in percentage by mass:

Ca _0.99 Si ₂ O ₂ N ₂ :0.01Eu ²⁺ (blue-green phosphor) 30%, with a peak emission wavelength of 493nm;

Lu _2.96 Al ₅ O ₁₂ :0.04Ce ³⁺ (green phosphor) 60%, its emission peak wavelength is 530nm;

(Sr,Ca) _0.98 AlSiN ₃ :0.02Eu ²⁺ (red phosphor) 10%, its emission peak wavelength is 660nm.

Experimental example

The luminous spectra of the LED devices of Examples 1-3 and Comparative Example 1 were tested using a HAAS 2000 photoelectric integrating sphere device from Yuanfang, and the results are shown in Figures 2-4. The light color parameters of the LED devices of Examples 1-6 and Comparative Example 1 were tested using a HAAS2000 photoelectric integrating sphere device from Yuanfang, and the results are shown in Table 1 below.

Table 1 Light color parameters of Examples 1-6 and Comparative Example 1

As shown in Figures 2-4 and Table 1, Examples 1-3 provide LED devices with color temperatures of 5000K, 4000K, 3000K, etc. respectively. The LED devices provided by the embodiments of the present invention can be configured with different color temperatures, and can all cover the visible spectrum, and have the advantages of high color rendering index and full spectrum. At the same time, in Figures 2-4, the luminous intensity of Examples 1-3 in the blue light region (wavelength of about 460nm) is relatively low, indicating that the LED devices provided by the present invention specifically reduce the proportion of blue light, which is beneficial to protecting the health of users.

Compared with Comparative Example 1, the phosphor compositions of Examples 1-3 contain white phosphors, while the phosphor compositions of Comparative Example 1 do not contain white phosphors. As shown in Table 1, the color rendering effect of the LED devices of Examples 1-3 is higher than that of Comparative Example 1, and the Ra of Examples 1-3 reaches above 98, and R1-R15 all reach above 93; especially at the same color temperature of about 5000K, the color rendering index of the LED device of Example 1 is significantly higher than that of Comparative Example 1. This shows that the introduction of the above-mentioned white phosphor into the phosphor composition can produce a synergistic effect with the above-mentioned blue-green phosphor, green phosphor and red phosphor, effectively improving the color rendering of the LED device, so that the LED device has an extremely high color rendering index and excellent color reproduction ability.

The difference between Example 1 and Example 6 is that the green phosphor used in Example 6 is trivalent europium-doped alkaline earth metal silicate. As shown in Table 1, the color rendering effect of the LED device of Example 1 is significantly higher than that of Example 6. The test results show that the white phosphor (europium-doped alkaline earth metal chlorophosphate phosphor) and the green phosphor (cerium-doped garnet compound) have good spectral matching, and under their synergistic effect, the luminous effect of the phosphor can be effectively improved, and the color rendering performance of the LED device can be enhanced.

The components and proportions of the phosphor compositions of Example 1, Example 4, and Example 5 are the same, and the color temperature of the LED devices is about 5000 K. Among them, the rare earth ion doping concentration ratio relationship between the phosphor components in Example 1 and Example 5 is x:y=1:2, which satisfies the rare earth ion doping concentration ratio relationship proposed by the present invention, that is, x:y=1:(1.8-2.2); while Example 4 does not satisfy this doping concentration ratio relationship.

As shown in Table 1, compared with Example 4, the color rendering effect of the LED device of Example 1 is higher than that of Example 4; compared with Example 5, the color rendering effect of the LED device of Example 4 is lower than that of Example 5; compared with Example 1 and Example 5, there is no significant difference in the color rendering effect of the LED devices of the two. The test results show that, under the condition of satisfying the ratio of the doping concentration of the rare earth ions proposed in the present invention, the phosphor composition comprising the white phosphor and the green phosphor proposed in the present invention can produce the best synergistic effect, so that the color rendering performance of the LED device reaches the best state.

The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the protection scope of the claims of the present invention.

Claims (7)

1. An LED device comprising an LED chip and a phosphor composition;

The fluorescent powder composition comprises the following components in percentage by mass: 5-20% of blue-green fluorescent powder; 40-50% of green fluorescent powder; 26-44% of white fluorescent powder; 5-10% of red fluorescent powder;

The LED chip comprises a first chip unit and a second chip unit, wherein the light-emitting peak wavelength range of the first chip unit is 447.5nm-455nm, and the light-emitting peak wavelength range of the second chip unit is 395nm-410nm;

wherein, the light-emitting peak wavelength range of the blue-green fluorescent powder is 480nm-500nm; the light-emitting peak wavelength range of the green fluorescent powder is 520nm-540nm; the light-emitting peak wavelength range of the white fluorescent powder is 440nm-460nm; the light-emitting peak wavelength range of the red fluorescent powder is 650nm-670nm;

the white fluorescent powder comprises at least one of substances shown in chemical formula I,

X ¹ _2-x(PO₄)₃Cl:xEu²⁺, a compound of formula I,

In the chemical formula I, X ¹ is at least one selected from Ba and Sr, and the value range of X is more than or equal to 0.001 and less than or equal to 0.5;

The green phosphor includes at least one of substances having a chemical formula II,

X ² _3-yAl₅O₁₂:yCe³⁺, a compound of the formula II,

In the chemical formula II, X ² is at least one of Y, lu and Ga, and the value range of Y is more than or equal to 0.001 and less than or equal to 0.5;

The ratio relation between x in the chemical formula I and y in the chemical formula II is 1 (1.8-2.2).

2. The LED device of claim 1, wherein x in formula I has a value in the range of 0.01 ∈x ∈0.025.

3. The LED device of claim 1, wherein the blue-green phosphor comprises at least one of the substances of formula III,

X ³ _1-zSi₂O₂N₂:zEu²⁺, a compound of the formula III,

In the chemical formula III, X ³ is at least one selected from Ba, ca and Sr, and z is more than or equal to 0.001 and less than or equal to 0.5.

4. The LED device of claim 1, wherein the red phosphor comprises at least one of the substances of formula IV,

X ⁴ _1-mAlSiN₃:mEu²⁺, formula IV,

In the chemical formula IV, X ⁴ is at least one of Sr and Ca, and the value range of m is more than or equal to 0.001 and less than or equal to 0.5.

5. The LED device of claim 1, wherein the first chip unit has a peak emission wavelength range of 447.5nm to 452.5nm and the second chip unit has a peak emission wavelength range of 400nm to 410nm.

6. The LED device of claim 1, further comprising an LED encapsulant, wherein the phosphor composition and the LED encapsulant are mixed in a mass ratio of 1 (1.1-2.5).

7. The LED device of claim 1, wherein the LED device has a color rendering index Ra of greater than or equal to 98 and R1-R15 of greater than or equal to 93.