KR102100193B1 - Light emitting device - Google Patents

Abstract

The present invention relates to a light emitting device, and more particularly, to a light emitting device including a light emitting diode. The present invention, a light emitting device; A first phosphor that is excited by light emitted from the light emitting element and emits light having a central wavelength located in a band of 510 to 550 nm; A second phosphor that is excited by light emitted from the light emitting element and emits light having a central wavelength located in a band of 560 to 600 nm; And a third phosphor that is excited by light emitted from the light emitting element and emits light having a central wavelength located in a band of 610 to 630 nm, and a light absorption at a wavelength of 550 nm of 50% or less.

Description

Light emitting device {Light emitting device}

The present invention relates to a light emitting device, and more particularly, to a light emitting device including a light emitting diode.

Light emitting diodes (LEDs) are one of the candidates for the next generation of light emitting devices that can replace fluorescent lamps, which are the most representative of conventional lighting.

LEDs have less power consumption than conventional light sources, and unlike fluorescent lamps, they do not contain mercury, so they can be said to be environmentally friendly. In addition, it has the advantage of long life and fast response speed compared to conventional light sources.

Such an LED can be used with a phosphor that absorbs light emitted from the LED and emits light of various colors. Such phosphors can usually emit yellow, green and red light.

The white LED is currently manufactured with a blue light emitting LED and a phosphor that converts light emission wavelengths. As the use range of the white LED is increased, more efficient LEDs are required, and for this, improvement in luminous efficiency of the phosphor is required. In addition, according to this, there is an increasing demand for more reliable LEDs.

As the phosphor used for the LED, the YAG (Yttrium Aluminum Garnet) phosphor represented by U.S. Patent Registration No. 5998925, which is an oxide phosphor as a yellow phosphor, is known, but these YAG phosphors have poor thermal stability and deteriorate luminance and change color coordinates at high temperatures. Can cause problems. In addition, the emission color tone is limited, so the color reproduction range is narrow, and the phosphor absorbs a part of the blue LED light.

In addition, oxide phosphors and silicate-based phosphors are known as yellow to green-based phosphors, but these may have a negative effect on the reliability of the LED package because they have relatively low thermal stability and poor moisture resistance.

Accordingly, there is a need to develop a fluorescent material having high efficiency and reliability that can produce white light together with LEDs.

Moreover, as the blue light emitting LED becomes higher in power, the wavelength may move toward the shorter wavelength, and accordingly, the development of a yellow light emitting phosphor having high excitation efficiency even in the shorter wavelength is required.

In addition, it is required to develop a phosphor having excellent color rendering properties when used with LEDs to produce white light.

The present invention provides a light emitting device including a yellow light emitting phosphor having high efficiency, high brightness and high color rendering properties in a light emitting device.

As a first aspect for achieving the above technical problem, the present invention, a light emitting device; A first phosphor that is excited by light emitted from the light emitting element and emits light having a central wavelength located in a band of 510 to 550 nm; A second phosphor that is excited by light emitted from the light emitting element and emits light having a central wavelength located in a band of 560 to 600 nm; And a third phosphor that is excited by light emitted from the light emitting element and emits light having a central wavelength located in a band of 610 to 630 nm, and a light absorption at a wavelength of 550 nm of 50% or less.

Here, the second phosphor, at least one of α-type SiAlON (Li-α-SiAlON: Eu) having Li as a metal component and α-type SiAlON (Ca-α-SiAlON: Eu) having Ca as a metal component It can contain.

Here, the second phosphor is represented by Formula 1 below,

<Formula 1>

The m and n may satisfy at least one condition of 0 ≤ m ≤ 2 and 0 ≤ n ≤ 1.

Here, the first phosphor, BaYSi ₄ N ₇ : Eu, Ba ₃ Si ₆ O ₁₂ N ₂ : Eu, CaSi ₂ O ₂ N ₂ : Eu, SrYSi ₄ N ₇ : Eu, α type having Ca as a metal component SiAlON (Ca-α-SiAlON: Yb), LuAG, SrSi ₂ O ₂ N ₂ : Eu, and β-type SiAlON: Eu.

Here, when the sum of the first phosphor, the second phosphor, and the third phosphor is 100 wt%, the first phosphor may have a content of 62 to 75.8 wt%.

Here, the second phosphor, when the sum of the first phosphor, the second phosphor and the third phosphor is 100 wt%, may have a content of 20 to 35 wt%.

Here, the third phosphor, when the sum of the first phosphor, the second phosphor and the third phosphor is 100 wt%, may have a content of 3 to 4.2 wt%.

Here, the ratio of the third phosphor to the second phosphor may be 8.6 to 21.0%.

Here, the third phosphor, CaAlSiN ₃ : Eu, (Sr, Ca) AlSiN ₃ : Eu, Sr ₂ Si ₅ N ₈ : Eu, K ₂ SiF ₆ : Mn, La ₃ Si ₆ N ₁₁ : Ce, SrAlSiN ₃ : Eu, SrCN ₂ : Eu, Ca ₂ Si ₅ N ₈ : Eu, Ba ₂ Si ₅ N ₈ : Eu, SrAlSi ₄ N ₇ : Eu and (Sr, Ba) SiN ₂ : Eu have.

Here, the mixture of the first fluorescent substance, the second fluorescent substance, and the third fluorescent substance may have a half width of the emission spectrum of a wavelength band of 480 nm to 780 nm of 120 nm or more.

As a second aspect for achieving the above technical problem, the present invention, a light emitting device; A first phosphor that is excited by light emitted from the light emitting element and emits light having a central wavelength located in a band of 510 to 550 nm; A second phosphor that is excited by light emitted from the light emitting element and emits light having a central wavelength located in a band of 560 to 600 nm; And a third phosphor that is excited by light emitted from the light emitting device and emits light having a central wavelength located in a band of 610 to 630 nm, and the mixture of the first to third phosphors is emitted from the light emitting device. It is excited by light to emit light of a spectrum in which a central wavelength is located in a wavelength band of 480 to 780 nm, and a half width of the spectrum may be 120 nm or more.

Here, the third phosphor may be designed to minimize absorption of light by the excitation light.

Here, the third phosphor, the light absorption at a wavelength of 550 nm may be 50% or less.

Here, when the sum of the first phosphor, the second phosphor, and the third phosphor is 100 wt%, the first phosphor may have a content of 62 to 75.8 wt%.

Here, the second phosphor, when the sum of the first phosphor, the second phosphor and the third phosphor is 100 wt%, may have a content of 20 to 35 wt%.

Here, the third phosphor, when the sum of the first phosphor, the second phosphor and the third phosphor is 100 wt%, may have a content of 3 to 4.2 wt%.

As a third aspect for achieving the above technical problem, the present invention, a light emitting device; A first phosphor that is excited by light emitted from the light emitting element and emits light having a central wavelength located in a band of 510 to 550 nm; A second phosphor that is excited by light emitted from the light emitting element and emits light having a central wavelength located in a band of 560 to 600 nm; And a third phosphor that is excited by light emitted from the light emitting element and emits light having a central wavelength located in a band of 610 to 630 nm, and the weight ratio of the first phosphor, the second phosphor, and the third phosphor is When the sum of the first phosphor, the second phosphor and the third phosphor is 100 wt%, it may be 62 to 75.8 wt%, 20 to 35 wt%, and 3 to 4.2 wt%, respectively.

Here, the third phosphor, the light absorption at a wavelength of 550 nm may be 50% or less.

Here, the mixture of the first fluorescent substance, the second fluorescent substance, and the third fluorescent substance may have a half width of the emission spectrum of a wavelength band of 480 nm to 780 nm of 120 nm or more.

According to the present invention has the following effects.

First, through the present invention, a light emitting device including a yellow light emitting phosphor having excellent light emitting properties can be provided, and such a yellow light emitting phosphor can minimize a decrease in luminous flux (luminance) and improve color rendering index (CRI).

In addition, the color rendering index can be improved by the continuous spectrum design of the present invention, and by providing an optimal mixing ratio of phosphors for this purpose, it is possible to express the color of a wide gamut in a display through the implementation of a light emitting device having a wide spectrum. .

1 is a graph showing human visual characteristics.
2 is a graph showing a light emission spectrum in an example in which a white light emitting device package is implemented using a yellow light emitting phosphor.
3 to 5 are graphs showing excitation and emission spectra of a red phosphor.
6 is a graph showing a light emission spectrum when a white light emitting device package is implemented using the yellow light emitting phosphor of the present invention.
7 is a cross-sectional view showing an example of a light emitting device package in which the yellow light emitting phosphor of the present invention is used.
8 is a cross-sectional view showing another example of a light emitting device package in which the yellow light emitting phosphor of the present invention is used.
9 is a partially enlarged view of FIG. 7 for explaining a process in which white light is implemented using the yellow light-emitting phosphor of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

While the invention allows for various modifications and variations, specific embodiments thereof are illustrated and illustrated in the drawings, which will be described in detail below. However, it is not intended to limit the invention to the specific forms disclosed, but rather the invention includes all modifications, equivalents, and substitutes consistent with the spirit of the invention as defined by the claims.

When an element, such as a layer, region, or substrate, is referred to as being “on” another component, it will be understood that it may be present directly on the other element or intermediate elements may be present therebetween. .

Although the terms first, second, etc. can be used to describe various elements, components, regions, layers and / or regions, these elements, components, regions, layers and / or regions It will be understood that it should not be limited by these terms.

According to the present invention, green, amber (Amber; hereinafter referred to as amber) and red phosphors having excellent excitation efficiency by near ultraviolet and blue excitation sources can be mixed to realize yellow light having excellent luminance and high color rendering.

These yellow light-emitting phosphors, a first phosphor that emits light located in a band with a central wavelength of 510 to 550 nm (green phosphor), and a second phosphor that emits light having a center wavelength in a band of 560 to 600 nm (amber) Phosphor) and a third phosphor (red phosphor) that emits light positioned at a center wavelength of 610 to 630 nm.

Hereinafter, the first phosphor will be described as a green phosphor, the second phosphor as an amber phosphor, and the third phosphor as a red phosphor.

The green phosphor, the amber phosphor, and the red phosphor may include the following materials.

That is, the green phosphor, BaYSi ₄ N ₇ : Eu, Ba ₃ Si ₆ O ₁₂ N ₂ : Eu, CaSi ₂ O ₂ N ₂ : Eu, SrYSi ₄ N ₇ : Eu, α having alpha as a metal component (alpha) Type SiAlON (Ca-α-SiAlON: Yb), LuAG, SrSi ₂ O ₂ N ₂ : Eu and β (beta) type SiAlON: Eu.

The green phosphor may emit light in which the above-mentioned center wavelength is located in a band of 510 to 550 nm.

Here, LuAG is known as a chemical formula of Lu ₃ Al ₅ O ₁₂ : Ce, and β-type SiAlON can be expressed as a chemical formula in which Eu is added to the basic structural formula of Si _{6 -} zAl _z O _z N _8-z .

The amber phosphor may include at least one of α-type SiAlON (Li-α-SiAlON: Eu) having Li as a metal component and α-type SiAlON (Ca-α-SiAlON: Eu) having Ca as a metal component. .

Such an amber phosphor can emit light having the center wavelength mentioned above in the 560 to 600 nm band.

The red phosphor is CaAlSiN ₃ : Eu, (Sr, Ca) AlSiN ₃ : Eu (SCASN), Sr ₂ Si ₅ N ₈ : Eu, K ₂ SiF ₆ : Mn, La ₃ Si ₆ N ₁₁ : Ce, SrAlSiN ₃ : Eu, SrCN ₂ : Eu, Ca ₂ Si ₅ N ₈ : Eu, Ba ₂ Si ₅ N ₈ : Eu, SrAlSi ₄ N ₇ : Eu and (Sr, Ba) SiN ₂ : Eu .

Such a red phosphor may emit light having a central wavelength located in a band of 610 to 630 nm.

The green phosphor, the amber phosphor and the red phosphor mainly exemplify nitride phosphors or oxynitride phosphors, but it is needless to say that other phosphors may also be used.

Here, the amber phosphor is represented by Formula 1 below, and m and n may satisfy at least one condition of 0 ≤ m ≤ 2 and 0 ≤ n ≤ 1.

<Formula 1>

On the other hand, the red phosphor may have a light absorption rate of 50% or less at a wavelength of 550 nm. That is, the ratio excited by light having a wavelength of 550 nm may be 50% or less. This will be described later in detail.

The yellow light-emitting phosphor implemented by mixing the green phosphor, the amber phosphor, and the red phosphor having such characteristics may have a half width of the emission spectrum in a wavelength band of 480 nm to 780 nm of 120 nm or more. This may mean that the color rendering property of light is greatly increased.

Here, the green phosphor, when the sum of the green phosphor, the amber phosphor and the red phosphor is 100 wt% (weight ratio), may have a content of 62 to 75.8 wt%.

Here, the amber phosphor, when the sum of the green phosphor, the amber phosphor and the red phosphor is 100 wt%, may have a content of 20 to 35 wt%.

Here, the red phosphor, when the sum of the green phosphor, the amber phosphor and the red phosphor is 100 wt%, may have a content of 3 to 4.2 wt%.

Meanwhile, the ratio of the red phosphor to the amber phosphor may be 8.6 to 21.0%.

The mixture of the green phosphor, the amber phosphor and the red phosphor can be excited by near ultraviolet or blue light to emit yellow light of high luminance. In addition, the yellow light is mixed with the blue light, which is the excitation light, to emit white light having high luminance and high color rendering. The excitation rate is excellent in such near ultraviolet or blue light, and thus it is possible to exhibit high-efficiency phosphor characteristics.

The α-type SiAlON having Ca as a metal component has a light emission center wavelength of about 600 nm, but as described above, when Li-α-SiAlON with a center wavelength of 550 to 590 nm is used, the light emission with the same peak intensity is observed. The properties can be as high as 25%. More preferably, when the light having the center wavelength in the 578 to 588 nm band is allowed to emit light, the viewing characteristics can be further improved. In addition, color mixing may be further improved while increasing luminance by mixing a red phosphor having an adjusted amount of absorption in a band of 550 to 560 nm. However, as mentioned above, in some cases, the characteristics of the present invention can be achieved even in the case of a phosphor emitting light having a central wavelength located in the 560 to 600 nm band.

1 is a graph (Photonic curve) showing the characteristics of the human visual (視 感).

As shown, the value of human visibility has a maximum at approximately 555 nm wavelength. That is, for light of the same intensity, a person perceives light in the wavelength band of 555 nm as the strongest.

Therefore, compared to α-type SiAlON, which usually has a center wavelength of light emission of about 600 nm, Li-α-SiAlON having a center wavelength of 550 to 590 nm, which is used in the present invention, may be superior in luminous properties.

That is, since the light of the same intensity can be detected brighter, the adjustment of the emission wavelength may act as an effect of increasing luminance.

Li-α-SiAlON, which can be used as the amber phosphor of the present invention, can improve luminous properties by about 25% compared to Ca-α-SiAlON for emission of the same peak intensity.

In the present invention, in order to realize light emission having a center wavelength of 550 to 590 nm, the substitution amount of Li may be controlled and the amount of oxygen (Oxygen) may be adjusted during SiAlON synthesis.

Table 1 shows the emission wavelength (peak wavelength) and emission luminance of the phosphor obtained by adjusting the oxygen content (n; value in Formula 1) when implementing the amber phosphor.

In order to emit light, m and n in Formula 1 may satisfy at least one condition of 0 ≤ m ≤ 2 and 0 ≤ n ≤ 1. In addition, in Formula 1, x represents the content of the active agent (Eu), and is usually substituted within 10% of the metal ions (lithium (Li) and aluminum (Al)). That is, x may have a value between 0.01 and 0.1.

As shown in Table 1, it can be seen that the emission wavelength may be changed according to the content of oxygen (Oxygen) of the amber phosphor. That is, when the content (n) of oxygen (n) is 0, it can be seen that it has an emission wavelength of 588 nm and the emission luminance at this time has 95%. When the oxygen content (n) is 1, the emission wavelength It can be seen that silver can be lowered to 578 nm.

In addition, when the content (n) of oxygen (Oxygen) is changed between 1 ≤ n ≤ 2 in order to improve the luminous efficiency through additional visibility characteristics, it is possible to change the emission wavelength to 560 nm. As such, as the oxygen content is adjusted, it may be easy to shift the emission wavelength to a short wavelength, especially by increasing the oxygen content.

In Table 1, it can be seen that the emission luminance is highest when the oxygen content (n) is 0.1 and the emission wavelength is 583 nm.

As described above, in the present invention, yellow light having excellent luminance can be realized by mixing the first phosphor that is a green light-emitting phosphor and the second phosphor that is an amber color light-emitting phosphor.

In addition, the emission luminance can be improved by adjusting the emission wavelength and mixing ratio of the green phosphor and the amber phosphor, respectively. Along with this, a color rendering index (CRI) indicating color rendering properties of the light source may be improved together.

The color rendering index (CRI) is an index for the purpose of indicating the color rendering property of a light source, and is a measure of the degree to which the color perception of an object coincides with the color perception of the same object under a defined reference light.

Table 2 shows that the brightness and CRI can be improved by mixing the green phosphor and the amber phosphor.

That is, in contrast to the conventional yellow phosphor (Yellow phosphor; represents a commonly used YAG (Yttrium Aluminum Garnet) phosphor) and Ca-α-SiAlON using a yellow light-emitting phosphor, the green of the present invention ( It can be seen that the luminescence brightness and CRI can be improved compared to a conventional yellow phosphor by using a Green) phosphor (when having a peak wavelength of 535 nm) and an Amber phosphor (when having a peak wavelength of 583 nm).

2 is a graph showing an emission spectrum as an example in the case of implementing a white light emitting device package using a yellow light emitting phosphor.

As shown in FIG. 2, it can be seen that blue excitation light and a yellow light-emitting phosphor excited by the blue light are mixed to emit yellow light to emit white light of excellent quality.

That is, the example of the yellow light emitting phosphor (Green + 583 nm Amber) shows improved light characteristics compared to the conventional yellow light emitting phosphor (Yellow) and other examples (Green + 600 nm Amber).

As described above, the intensity and visibility of light in the yellow emission band are excellent, so that high-quality white light can be produced together with near-ultraviolet or blue light-emitting elements.

As described above, the light emitting device package that embodies yellow light emission by using a combination of a green phosphor and an amber phosphor has a strong peak intensity around a wavelength of 555 nm with excellent visibility.

However, as shown in FIG. 2, when looking at the spectrum of the light emitting device package, the half width of the wavelength in the 500 to 600 nm band may not be sufficiently wide from a high quality lighting point of view.

Therefore, it may be necessary to implement a uniform peak intensity in the visible light wavelength range (380 nm to 780 nm band) in order to realize high-quality color expression in illumination. Through this, the color rendering property represented by the color rendering index (CRI) of light can be improved to a level close to that of sunlight.

In addition, through the implementation of the light-emitting device package having such a wide spectrum, it is possible to express the color of a wide gamut in a display using the same.

As mentioned above, this color rendering index (CRI) is an index aimed at indicating the color rendering of a light source, the degree to which the color perception of an object under the sample light source matches the color perception of the same object under a defined reference light. Is a numerical value.

The color rendering index in lighting is a measure of how much the visual environment for recognizing color resembles the environment under sunlight. Specifically, the degree to which the reflected color of an object in the test light source matches the reflected color in the reference light Digitized to indicate the quality of lighting.

In order to improve the color rendering properties than in the case of implementing the yellow phosphor through the mixing of the green phosphor and the amber phosphor described above, the peak intensity evenly distributed in the visible light wavelength range (380 nm to 780 nm) may be distributed by changing the emission spectrum to a wider form. Can be implemented.

In order to improve the spectrum in this form, a mixed phosphor may be realized by adding a long-wavelength red phosphor to a green phosphor and an amber phosphor. Through this, the spectrum at a long wavelength of 580 nm or more can be increased, and even peak intensity can be realized.

In addition, the content of the green phosphor may be increased in order to adjust the color balance for the mixing of the red phosphor. That is, since the spectrum of the long wavelength (above 550 nm) may increase based on 550 nm according to the mixing of the red phosphor as above, the content of the short wavelength (below 550 nm) green phosphor may be increased for color balance.

Meanwhile, as illustrated in FIG. 3, the red phosphor may emit light by absorbing (exciting) light emission of the green phosphor and amber phosphor in addition to the blue excitation light, and yellow light, which is a mixed light of these light emission.

In FIG. 3, the dotted line on the left represents the excitation spectrum, that is, the spectrum of light absorbed by the red phosphor, and the solid line on the right represents the emission spectrum.

Accordingly, by controlling the excitation spectrum of the red phosphor, it is possible to minimize absorption of light other than blue excitation light by the red phosphor. Through this, it is possible to prevent the luminous efficiency of the yellow phosphor from decreasing, and as a result, the luminous efficiency can be increased while improving color rendering.

To this end, the absorption intensity (Intensity) at a wavelength of 550 nm of the red phosphor may be adjusted to be 50% or less. That is, it is possible to minimize the absorption of luminescence of the green, amber and yellow phosphors by adjusting the point at which 50% of the absorption spectral intensity of the red phosphor is 550 nm or less.

The detailed design of the red phosphor is as follows.

As mentioned above, when a red phosphor is mixed to improve luminescence properties such as improving color rendering properties, as shown in FIG. 4, the emission wavelength band by phosphors other than excitation light (eg, green 530 nm and yellow light (560 nm), so that the luminance of light can be reduced.

In order to minimize this phenomenon, the excitation spectrum of the red phosphor is moved to a short wavelength so that the absorption amount of light is 50% below the 550 nm band, so that the absorption of light other than the excitation light can be minimized.

4 shows an example of an excitation spectrum according to each red emission wavelength. In addition, Fig. 5 shows an example of a spectrum of red phosphors having different peak wavelengths.

In this example, it can be seen that the red phosphor having a peak wavelength of 610 nm has an absorption rate of 50% or less at a wavelength of 550 nm. Exactly, it can be seen that the absorption rate becomes 50% at a wavelength of 547 nm. In addition, a red phosphor having a 630 nm peak wavelength has an absorption rate of 50% at a wavelength of 564 nm, a red phosphor having a 650 nm peak wavelength has an absorption rate of 50% at a wavelength of 585 nm, and a red phosphor having a 660 nm peak wavelength It can be seen that the absorption rate is 50% at a wavelength of 600 nm.

Through this design, it can be seen that the absorption by light other than the excitation light can be minimized by using a red phosphor having a peak wavelength of 610 nm with an absorption rate of 50% or less at a wavelength of 550 nm. However, in some cases, a red phosphor having peak wavelengths of 630 nm, 650 nm, and 660 nm may be used in the above example.

As described above, the absorption rate of the red phosphor can be adjusted, and the phosphor according to the peak wavelength of the adjusted red phosphor can be selected to improve color rendering and increase luminous efficiency.

<Example>

Table 3 shows the CRI and the relative luminous flux according to the content ratio of the phosphor.

Table 3 implements a yellow phosphor by mixing a green phosphor, an Amber phosphor having a peak wavelength of 580 nm and a red phosphor having a peak wavelength of 610 nm, and shows CRI and relative light flux according to the content of these phosphors.

Here, an example using LuAG as a green phosphor, Li-α-SiAlON as an amber phosphor, and SCASN ((Sr, Ca) AlSiN ₃ : Eu) with an excitation wavelength adjusted as a red phosphor is shown.

When using such a material, it can be seen that, as in Condition 3, the optimal CRI and luminous efficiency (relative luminous flux) are shown when the ratio of the red phosphor to the amber phosphor is 12.7%. Here, the luminous efficiency is a relative value, and represents the relative value when the condition 3 is set to 100%.

In addition, the weight ratio of the green phosphor, amber phosphor, and red phosphor at this time is 67.7 wt%, 28.66 wt%, and 3.64 wt%, respectively. At this time, these weight ratios are 67.7 wt%, 28.7 wt%, and 3.6 wt%, respectively, when rounded off to the second decimal place, and CRI and relative light speed by these values may have sufficiently meaningful values. For example, this rounded value can be within the error range for the optimal weight ratio in terms of CRI and relative luminous flux.

However, other cases may also be implemented as phosphors, and may have CRI and luminous efficiency values that may have meaning. That is, as shown in Table 3, when the weight ratio of the green phosphor is 62 to 75.8 wt%, the amber phosphor is 20 to 35 wt%, and the red phosphor is 3 to 4.2 wt% have.

In addition, when the ratio of the red phosphor to the amber phosphor is 8.6 to 21.0%, when applied to a light emitting device package, CRI or luminous efficiency may be considered as a meaningful value that can be relatively increased.

Table 4 shows the CRI and the relative luminous flux comparing different phosphors from those having the optimal CRI and luminous efficiency (relative luminous flux) ratio in Table 3.

The comparative yellow phosphor (Yellow) shows an example of the YAG phosphor shown in Condition 1, and it can be seen that the YAG phosphor has a CRI of 67 and a relative luminous flux of 103%.

In addition, when using the green phosphor shown in Condition 2 and the amber phosphor having a peak wavelength of 600 nm, it can be seen that the CRI increases to 74 but the relative luminous flux decreases.

On the other hand, when using the green phosphor and the amber phosphor having a peak wavelength of 580 nm, it can be seen that the CIR is increased to 71 compared to the YAG phosphor under condition 1, and the relative luminous flux is also increased to 103%.

As a comparative example, when using the green phosphor shown in Condition 4, an amber phosphor having a 580 nm peak wavelength and a red phosphor having a 630 nm peak wavelength, the CRI rises to 74, but the relative luminous flux is reduced to 100%. have.

However, in the case of using the green phosphor according to the present embodiment shown in Condition 5, the amber phosphor having a 580 nm peak wavelength and the red phosphor having a 610 nm peak wavelength, the CIR rises to 74, and the relative luminous flux is 103% and the YAG phosphor It can be seen that it is not smaller than that. Here, the relative luminous flux of condition 5 was expressed by matching 103% in the same manner as the YAG phosphor, except that it shows the same condition as condition 3 in table 3.

6 is a graph showing a light emission spectrum when a white light emitting device package is implemented using the yellow light emitting phosphor of the present invention.

As shown in FIG. 6, it can be seen that the blue light near the wavelength of 430 nm and the yellow light-emitting phosphor according to the present invention are excited by the blue light to mix and emit yellow light to emit white light of excellent quality. .

That is, the yellow light-emitting phosphor of the present invention (Green + Amber + Red) shows improved light characteristics compared to the comparative example (Green + Amber).

As described above, it can be seen that the intensity and visibility of light are not deteriorated compared to the comparative example, and high-quality white light can be produced together with near-ultraviolet or blue light-emitting devices.

In the case of this comparative example, as shown in FIG. 2, it already shows improved properties compared to a conventional yellow phosphor such as YAG.

By the way, as shown, the spectrum of the yellow light-emitting phosphor of the present invention can be seen that a relatively even peak intensity is distributed in the visible light wavelength range (380 nm to 780 nm), and thus, the emission spectrum is a wider form It can be seen that the color rendering properties are improved by changing to.

As described above, it can be seen that it is excited by near ultraviolet or blue light to emit light of a broad spectrum located in a wavelength band of 480 to 780 nm, and the half width of the spectrum is 120 nm, which is wider than that of the comparative example of 118 nm. It can be seen that it has the above value. Specifically, in this example, it can be seen that the half-width of the emission spectrum of the yellow phosphor according to the present invention has 131 nm.

As described above, the present invention can provide a yellow light-emitting phosphor having excellent light-emitting properties, and it can be seen that such a yellow light-emitting phosphor minimizes a decrease in luminous flux (luminance) and improves a color rendering index (CRI). .

In addition, it can be used in the design of a luminous body having a high color rendering property of CRI 80 or higher in this way, and it is expected that the color rendering property (CRI) can be improved to a level close to sunlight.

In addition, the color rendering index can be improved by the continuous spectrum design of the present invention, and by providing the optimal mixing ratio of phosphors for this purpose, a wide-spectrum luminous body (for example, a light emitting device package) has a wide color gamut in a display. Can express the color of.

<Light emitting device package>

7 is a cross-sectional view showing an example of a light emitting device package in which the yellow light emitting phosphor of the present invention is used. 7 shows an example of a lamp-type light emitting device package 100 according to an embodiment of the present invention. The light emitting device package may form a light emitting device.

The lamp-type white light emitting device package 100 includes a pair of lead frames 110 and 120 and a light emitting device 130 that generates light according to application of a voltage.

The light emitting device 130 is electrically connected to the lead frames 110 and 120 by a wire 140, and a light transmissive resin 150 is molded on the light emitting device 130. The light emitting device 130 may emit near ultraviolet light or blue light.

In addition, a laser diode, a surface emitting laser diode, an inorganic electroluminescent element, an organic electroluminescent element, or the like may be used as a light emitting element having a main emission peak in the same wavelength region instead of the near ultraviolet light emitting element. The present invention shows an example in which a nitride semiconductor light emitting diode is used as a preferred application example. In FIG. 7, the light emitting device 130 is schematically expressed, and both horizontal or vertical nitride semiconductor light emitting diodes may be used.

Phosphors 170, 171, and 172 (see FIG. 9) may be dispersed in the light-transmitting resin 150, and an exterior material 160 that closes the external space of the entire device may be provided on the light-transmitting resin 150. You can.

The phosphors 170, 171, and 172 used herein each include a first phosphor (green phosphor; 170), a second phosphor (amber phosphor; 171), and a third phosphor (red phosphor; 172) described above, respectively. 130) to emit yellow light. If necessary, other phosphors may be further mixed and used. Two or more kinds of the phosphor may be provided.

The light-transmitting resin 150 used as a molding member may be a light-transmitting epoxy resin, silicone resin, polyimide resin, urea resin, acrylic resin, or the like. Preferably, a light transmissive epoxy resin or a light transmissive silicone resin may be used.

The light-transmitting resin 150 of this embodiment may also be molded entirely around the light-emitting element 130, but may be partially molded and provided on the light-emitting portion as needed.

That is, in the case of a high-power light-emitting element, when molding as a whole due to the enlargement of the light-emitting element 130, it may be disadvantageous for uniform dispersion of the phosphors 170, 171, and 172 dispersed in the light-transmitting resin 150. In this case, it may be advantageous to partially mold the light emitting site.

8 is a cross-sectional view showing another example of a light emitting device package in which the yellow light emitting phosphor of the present invention is used. 8 shows a surface mount type light emitting device package 200.

The surface-mounted light emitting device package 200 according to an embodiment of the present invention is provided with lead frames 210 and 220 of positive and negative electrodes, as shown in FIG. 8, and lead frames 210 of the positive and negative electrodes , 220, and a light emitting device 240 positioned on any one of the sides to generate light according to application of a voltage. The light emitting device 240 may use a light emitting diode or a laser diode.

8 shows an example of a light emitting device 240 having a horizontal structure, it goes without saying that a light emitting device having a vertical structure may be used.

The light emitting device 240 is electrically connected to the lead frames 210 and 220 by a wire 250, and a light transmissive resin 260 is molded on the light emitting device 240. The lead frames 210 and 220 may be fixed by the package body 230, and the package body 230 may provide a reflective cup shape.

In addition, phosphors 270, 271, and 272 may be dispersed in the light-transmitting resin 260.

The phosphors 270, 271, and 272 used herein may be used by mixing and dispersing the first phosphor 270, the second phosphor 271, and the third phosphor 273 described above, and other phosphors are dispersed together. It can be provided. Two or more kinds of the phosphor may be provided.

The light-transmitting resin 260 used as a molding member may be a light-transmitting epoxy resin, silicone resin, polyimide resin, urea resin, acrylic resin, or the like. Preferably, a light transmissive epoxy resin or a light transmissive silicone resin may be used.

The light-transmitting resin 260 may be molded entirely around the light-emitting element 240, but may be partially molded to the light-emitting portion as necessary.

Other parts not described may be the same as those described with reference to FIG. 7.

The light emitting device packages 100 and 200 according to the present invention described in detail above may be implemented as a white light emitting package.

FIG. 9 is a partially enlarged view of FIG. 7, and the process of implementing white light is as follows. This description can be applied to the case shown in FIG. 8 as it is.

Blue light in the wavelength region of 400 to 480 nm corresponding to near ultraviolet or blue light emitted from the light emitting device 130 passes through the phosphors 170, 171, and 172.

Here, some light excites the phosphors 170, 171, and 172 to generate light having a main peak in the emission wavelength center of 500 to 600 nm as shown in FIG. 6, and the rest of the light is transmitted as blue light. Order.

At this time, the light emitted from the light emitting element 130, as shown, excites each of the phosphors 170, 171, and 172, and light (a, b, c) is emitted from these phosphors and mixed to produce yellow light. The yellow light may be emitted and mixed with the blue light of the light emitting device 130 to emit white light.

As a result, white light having a broad wavelength spectrum of 400 to 700 nm is emitted. At this time, a wider spectrum is formed by the red phosphor 172, and thus high-quality light having excellent color rendering properties can be realized.

On the other hand, the embodiments of the present invention disclosed in the specification and drawings are merely presented as specific examples to aid understanding, and are not intended to limit the scope of the present invention. It is apparent to those skilled in the art to which the present invention pertains that other modified examples based on the technical idea of the present invention can be implemented in addition to the embodiments disclosed herein.

100, 200: light emitting device package 110, 120, 210, 220: lead frame
130, 240: light-emitting element 140, 250: wire
150, 260: light-transmitting resin 160: exterior material
170, 171, 172, 270, 271, 272: phosphor
230: package body

Claims (19)

Light emitting element;
A first phosphor that is excited by light emitted from the light emitting element and emits light having a central wavelength located in a band of 510 to 550 nm;
It includes an α-type SiAlON (Li-α-SiAlON: Eu) having Li as a metal component, and is excited by light emitted from the light emitting device, so that an oxygen component emits light located at a center wavelength of 578 to 588 nm. A second phosphor having a; And
Characterized in that it comprises a third phosphor that is excited by the light emitted from the light emitting element and the central wavelength emits light located in the 610 to 630 nm band, and the light absorption at a wavelength of 550 nm is 50% or less. Light emitting device. delete The method of claim 1, wherein the second phosphor is represented by the following formula (1),
<Formula 1>

The x, m and n, 0.01 ≤ x ≤ 0.1, 0 ≤ m ≤ 2 and 0 ≤ n ≤ 1 satisfying at least one of the conditions of the light emitting device. According to claim 1, The first phosphor, BaYSi ₄ N ₇ : Eu, Ba ₃ Si ₆ O ₁₂ N ₂ : Eu, CaSi ₂ O ₂ N ₂ : Eu, SrYSi ₄ N ₇ : Eu, Ca metal component A light emitting device comprising at least one of α-type SiAlON (Ca-α-SiAlON: Yb), Lu ₃ Al ₅ O ₁₂ : Ce, and SrSi ₂ O ₂ N ₂ : Eu. The light emitting device according to claim 1, wherein the first phosphor has a content of 62 to 75.8 wt% when the sum of the first to third phosphors is 100 wt%. The light emitting device according to claim 1, wherein the second phosphor has a content of 20 to 35 wt% when the sum of the first to third phosphors is 100 wt%. The light emitting device according to claim 1, wherein the third phosphor has a content of 3 to 4.2 wt% when the sum of the first phosphor to the third phosphor is 100 wt%. The light emitting device according to claim 1, wherein a ratio of the third phosphor to the second phosphor is 8.6 to 21.0%. According to claim 1, The third phosphor, CaAlSiN ₃ : Eu, (Sr, Ca) AlSiN ₃ : Eu, Sr ₂ Si ₅ N ₈ : Eu, K ₂ SiF ₆ : Mn, La ₃ Si ₆ N ₁₁ : Ce, SrAlSiN ₃ : Eu, SrCN ₂ : Eu, Ca ₂ Si ₅ N ₈ : Eu, Ba ₂ Si ₅ N ₈ : Eu, SrAlSi ₄ N ₇ : Eu and (Sr, Ba) SiN ₂ : Eu A light emitting device comprising a. The light emitting device according to claim 1, wherein the mixture of the first phosphor, the second phosphor and the third phosphor has a half width of the emission spectrum in a wavelength band of 480 nm to 780 nm of 120 nm or more. Light emitting element;
A first phosphor that is excited by light emitted from the light emitting element and emits light having a central wavelength located in a band of 510 to 550 nm;
It includes an α-type SiAlON (Li-α-SiAlON: Eu) having Li as a metal component, and is excited by light emitted from the light emitting device, so that an oxygen component emits light located at a center wavelength of 578 to 588 nm. A second phosphor having a; And
It includes a third phosphor that is excited by the light emitted from the light emitting element and the central wavelength emits light located in the 610 to 630 nm band, and the light absorption at a wavelength of 550 nm is 50% or less,
The mixture of the first to third phosphors is excited by light emitted from the light emitting device to emit light of a spectrum in which a central wavelength is located in a wavelength band of 480 to 780 nm, and a half width of the spectrum is 120 nm or more Light emitting device to be made. 12. The light emitting device of claim 11, wherein the third phosphor is designed to minimize absorption of light by light emitted and excited from the light emitting element. delete The light emitting device according to claim 11, wherein the first phosphor has a content of 62 to 75.8 wt% when the sum of the first phosphor, the second phosphor and the third phosphor is 100 wt%. The light emitting device according to claim 11, wherein the second phosphor has a content of 20 to 35 wt% when the sum of the first phosphor, the second phosphor and the third phosphor is 100 wt%. The light emitting device according to claim 11, wherein the third phosphor has a content of 3 to 4.2 wt% when the sum of the first phosphor, the second phosphor and the third phosphor is 100 wt%. Light emitting element;
A first phosphor that is excited by light emitted from the light emitting element and emits light having a central wavelength located in a band of 510 to 550 nm;
It includes an α-type SiAlON (Li-α-SiAlON: Eu) having Li as a metal component, and is excited by light emitted from the light emitting device, so that an oxygen component emits light located at a center wavelength of 578 to 588 nm. A second phosphor having a; And
And a third phosphor that is excited by light emitted from the light emitting element and emits light having a central wavelength located in a band of 610 to 630 nm,
The weight ratio of the first phosphor, the second phosphor and the third phosphor is 62 to 75.8 wt%, 20 to 35 wt% and 3, respectively, when the sum of the first phosphor, the second phosphor and the third phosphor is 100 wt%, respectively. To 4.2 wt%. 18. The light emitting device according to claim 17, wherein the third phosphor has a light absorption rate of 50% or less at a wavelength of 550 nm. The light emitting device according to claim 17, wherein the mixture of the first phosphor, the second phosphor, and the third phosphor has a half width of the emission spectrum in a wavelength band of 480 nm to 780 nm of 120 nm or more.

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