KR20170054801A - Phosphor emitting yellow light and light emitting device using the same - Google Patents

Abstract

The present invention relates to a fluorescent body and, more specifically, to a yellow light emitting fluorescent body and a light emitting device using the same. The yellow light emitting fluorescent body comprises: a first fluorescent body including at least one of Lu3Al5O12:Ce and SrSi2O2N2; and a second fluorescent body which is mixed with the first fluorescent body to become a mixture, includes Ba2Si5N8, is excited by a near ultraviolet ray or blue light, and, subsequently, emits light having a center wave located in a band of 550-590 nm. The mixture of the first fluorescent body and the second fluorescent body is excited by the near ultraviolet ray or the blue light and can emit yellow light.

Description

[0001] The present invention relates to a yellow light-emitting phosphor and a light-emitting device using the same,

More particularly, the present invention relates to a yellow light-emitting phosphor and a light-emitting device using the same.

BACKGROUND ART [0002] Light emitting diodes (LEDs) are one of the next-generation light emitting device candidates that can replace fluorescent light, which is one of the most typical conventional lighting.

LEDs have less power consumption than conventional light sources, and unlike fluorescent lamps, they do not contain mercury and can be said to be environmentally friendly. In addition, it has a longer life span and faster response time than conventional light sources.

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

White LEDs are currently being fabricated with a blue emitting LED and a phosphor that converts the emission wavelength of the light emitted from the LED. As the use range of such a white LED becomes larger, a more efficient LED is required. For this purpose, improvement of the luminous efficiency of the phosphor is required. In addition, there is a growing demand for more reliable LEDs.

As a phosphor used for the LED, a YAG phosphor (Yttrium Aluminum Garnet) fluorescent material (Y ₃ Al ₅ O ₁₂ : Ce) represented by US Patent No. 5,999,095, which is an oxide fluorescent substance, is typically known as a yellow fluorescent material. When the thermal stability is low and the temperature is high, problems such as a decrease in luminance and a change in color coordinates may occur.

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

Accordingly, it is required to develop a phosphor with high efficiency and high reliability that can produce white light together with an LED.

Furthermore, as the blue emission LED becomes higher in output, the wavelength can be shifted to the short wavelength side. Accordingly, development of a yellow emission phosphor having a high excitation efficiency even in a short wavelength is required.

Accordingly, a light emitting device with high efficiency and high output using such a high-efficiency yellow light-emitting fluorescent substance is required.

An object of the present invention is to provide a yellow light emitting phosphor having high efficiency and high luminance in a phosphor and a light emitting device using the same.

According to a first aspect of the present invention, there is provided a yellow light-emitting phosphor comprising: a first phosphor containing at least one of Lu ₃ Al ₅ O ₁₂ : Ce and SrSi ₂ O ₂ N ₂ ; And a second phosphor which is mixed with the first phosphor to form a mixture and emits light containing Ba ₂ Si ₅ N ₈ and excited by near ultraviolet light or blue light and having a center wavelength in the range of 550 to 590 nm, And the mixture of the first phosphor and the second phosphor may be excited by the near ultraviolet light or the blue light to emit yellow light.

Here, as the second phosphor, Eu substituted with Ba may be used as an activator.

At this time, Eu may be substituted with Ba in an amount of 0.05 to 0.2 mol.

Here, the excitation spectrum of the mixture of the first and second phosphors may have a higher excitation ratio than the YAG (Yttrium Aluminum Garnet) phosphor in the wavelength band of 360 to 460 nm.

At this time, the excitation spectrum of the mixture of the first phosphor and the second phosphor may have an excitation ratio of 50% or more with respect to the peak at a wavelength of 410 nm.

Here, the second phosphor may have an amount of 40 to 60 w% based on 100 wt% of the sum of the first phosphor and the second phosphor.

On the other hand, it may further include a third phosphor in a red wavelength band.

According to a second aspect of the present invention, there is provided a light emitting device comprising: a light emitting element; A first phosphor that is excited by light emitted from the light emitting device to emit green light; And a second phosphor that emits light having a center wavelength in a range of 550 to 590 nm by being excited by the light emitted from the light emitting device, the _second phosphor being mixed with the first phosphor and comprising Ba ₂ Si ₅ N ₈ , And the mixture of the first phosphor and the second phosphor is excited by the near ultraviolet light or the blue light to emit yellow light.

Here, the first phosphor may include at least one of Lu ₃ Al ₅ O ₁₂ : Ce and SrSi ₂ O ₂ N ₂ .

Here, as the second phosphor, Eu substituted with Ba may be used as an activator.

At this time, Eu may be substituted with Ba in an amount of 0.05 to 0.2 mol.

Here, the second phosphor may have an amount of 40 to 60 wt% based on 100 wt% of the sum of the first phosphor and the second phosphor.

On the other hand, it may further include a third phosphor in a red wavelength band.

The present invention has the following effects.

First, the yellow light-emitting phosphor of the present invention can improve the luminosity characteristic and the luminance. At the same time, the color rendering index is improved and a phosphor of high efficiency can be provided.

In addition, the excitation ratio of the yellow light-emitting fluorescent substance of the present invention can be enhanced by the excitation light of 450 nm or less, and thus the luminescence characteristics can be further improved as the light emitting device becomes higher output.

On the other hand, the yellow light emitting phosphor of the present invention has excellent thermal stability at a high temperature and can stably maintain brightness even when driving a high output light source.

By using the yellow light-emitting phosphor and the light-emitting element, a highly efficient light-emitting device can be realized.

Fig. 1 is a graph showing the visual acuity of a person.
2 is a graph showing the excitation spectrum of the yellow light-emitting fluorescent substance of the present invention.
3 is a graph showing the emission spectrum of the yellow light-emitting fluorescent substance of the present invention.
4 is a graph showing the emission spectrum of a white light emitting device package using the yellow light emitting phosphor of the present invention.
5 is a cross-sectional view showing an example of a light emitting device package using the yellow light emitting phosphor of the present invention.
6 is a cross-sectional view showing another example of the light emitting device package using the yellow light emitting phosphor of the present invention.
FIG. 7 is a partially enlarged view of FIG. 5 to explain the process of realizing white light using the yellow light-emitting fluorescent material of the present invention.

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

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. Rather, the intention is not to limit the invention to the particular forms disclosed, but rather, the invention includes all modifications, equivalents and substitutions that are consistent with the spirit of the invention as defined by the claims.

It will be appreciated that when an element such as a layer, region or substrate is referred to as being present on another element "on," it may be directly on the other element or there may be an intermediate element in between .

Although the terms first, second, etc. may be used to describe various elements, components, regions, layers and / or regions, such elements, components, regions, layers and / And should not be limited by these terms.

First, the yellow light-emitting fluorescent substance according to the present invention will be described.

According to the present invention, it is possible to realize a yellow light-emitting phosphor capable of emitting yellow light having high luminance by mixing green and amber (hereinafter referred to as amber) phosphors having excellent excitation efficiency by near ultraviolet and blue excitation sources.

In order to achieve the above object, the present invention provides a phosphor comprising at least one of Lu ₃ Al ₅ O ₁₂ : Ce (LuAG) and SrSi ₂ O ₂ N ₂ , which is a green phosphor having excellent luminous efficiency by near ultraviolet and blue excitation light, The first phosphor can be used.

The first phosphor can be excited by the near ultraviolet light and the blue excitation light to emit light in the green wavelength band. The first phosphor may have a center wavelength in a range of 530 to 550 nm.

Here, LuAG is known as the formula Lu ₃ Al ₅ O ₁₂ : Ce. In addition, at least one of LSN (La ₃ Si ₆ N ₁₁ : Ce), SrSi ₂ O ₂ N ₂ : Eu and BaSi ₂ O ₂ N ₂ phosphor may be used.

In addition, the phosphor may include a second phosphor having a new composition having an excellent luminosity characteristic and having an optimal emission wavelength capable of emitting yellow light of high luminance mixed with the first phosphor. Such a second phosphor can be excited by the near ultraviolet light and the blue excitation light to emit light in the amber wavelength band.

Such a mixture of the first phosphor and the second phosphor can be excited by near ultraviolet light or blue light to emit yellow light of high luminance. Further, the excitation ratio is excellent in such near ultraviolet light or blue light, and high-efficiency phosphor characteristics can be exhibited. In addition, it has excellent thermal stability and can stably maintain the emission luminance in a high temperature environment due to heat generated from a high output light source.

The second phosphor may use Ba ₂ Si ₅ N ₈ and the Ba ₂ Si ₅ N ₈ phosphor may be excited by near ultraviolet light or blue light to emit light having a center wavelength in the range of 550 to 590 nm .

As described above, when Ba ₂ Si ₅ N ₈ having a peak wavelength of 550 to 590 nm is used, the luminous efficiency can be improved by about 25% with respect to light emission having the same peak intensity. And more preferably, the center wavelength is made to emit light located in the 578 to 588 nm band, the luminosity characteristic can be further improved.

1 is a photonic curve showing a person's visual sense characteristic.

As shown, the value of a human's relative intensity has a maximum value at a wavelength of about 555 nm. That is, for light of the same intensity, one perceives light in the 555 nm wavelength band as the strongest.

Therefore, compared to a green phosphor such as? -Type SiAlON having a center wavelength of about 600 nm, Ba ₂ Si ₅ N ₈ having a central wavelength of 550 to 590 nm used in the present invention can be more excellent have.

That is, since a person can perceive a light with the same intensity more brightly, the adjustment of the light emission wavelength can act as an effect of increasing brightness.

Ba ₂ Si ₅ N ₈ , which can be used as the second phosphor of the present invention, has an improved luminous efficiency of about 25% as compared with other phosphors such as Ca- alpha -SiAlON for the emission of the same peak intensity (At CIE 1924 photopic value, 0.6949 at emission wavelength 595 nm and 0.87 at emission wavelength 580 nm).

In addition, as described above, since the phosphor has excellent thermal stability at a high temperature (100 ° C or higher) as compared with a silicate phosphor excellent in emission luminance of the same wavelength band, it can stably maintain luminance even in heat generated when a high output light source is driven have.

Table 1 below shows the relative brightness of each phosphor relative to room temperature versus temperature.

As shown in Table 1, it can be seen that the brightness of Ba ₂ Si ₅ N ₈ does not substantially decrease as the temperature rises to 100 ° C and 150 ° C. On the other hand, the brightness of Ca-α-SiAlON and silicate phosphors decreases rapidly as the temperature rises.

As described above, in the present invention, the first phosphor, which is a green light-emitting phosphor, and the second phosphor, which is an amber color light-emitting phosphor, are mixed to realize yellow light excellent in luminance and thermal stability.

Meanwhile, the Ba ₂ Si ₅ N ₈ phosphor that can be used as the second phosphor of the present invention can use europium (Eu) as an activator.

Ba ₂ Si ₅ N ₈ can control the substitution amount of Ba element equivalent to (2+) Eu in order to realize luminescence in the wavelength band around 580 nm. That is, the emission wavelength can be controlled by adjusting the substitution amount of Eu element.

Table 2 below shows the substitution amount of Eu in the Ba ₂ Si ₅ N ₈ phosphor and the corresponding emission wavelength.

As shown in Table 2, Eu may be substituted with Ba in an amount of 0.05 to 0.2 mol in the Ba ₂ Si ₅ N ₈ phosphor. That is, it may be substituted with Ba in an amount of 5 to 20 mol%.

In addition, it can be seen that 0.05 mol is substituted for Ba (Ba 1.95, Eu 0.05) Si ₅ N ₈ to emit light of 580 nm wavelength.

On the other hand, as described above, Eu may be substituted with Ba in an amount of 0.05 to 0.2 mol in order to improve the luminosity characteristic.

Further, by adjusting the emission wavelength and mixing ratio of each of the first phosphor and the second phosphor, the emission luminance can be improved. In addition, the color rendering index (CRI) indicating the color rendering property of the light source can be improved together.

The color rendering index (CRI) is an index for indicating the color rendering property of a light source, and is a numerical value indicating the degree to which the color perception of the object under the sample light source matches the color perception of the same object under the reference light prescribed.

Table 3 shows that the luminance and CRI of light can be improved by mixing the first phosphor and the second phosphor as the amber color light emitting phosphor.

That is, in contrast to the implementation of a yellow light-emitting phosphor using a conventional yellow phosphor (yellow phosphor, commonly used YAG phosphor) and Ca-? -SiAlON, the first phosphor of the present invention (When having a wavelength of 580 nm) and a second phosphor (having a peak wavelength of 580 nm), the light emission luminance and the CRI can be improved as compared with the conventional yellow phosphor.

2 is a graph showing the excitation spectrum of the yellow light-emitting fluorescent substance of the present invention. This spectrum shows the wavelength band in which the yellow light-emitting fluorescent substance of the present invention is excited and the degree of excitation at the wavelength.

As shown in FIG. 2, the yellow light-emitting fluorescent substance of the present invention is superior in the degree of excitation at a shorter wavelength as compared with the conventional yellow light-emitting fluorescent substance (Yellow, for example, YAG fluorescent substance) indicated by a dotted line.

For example, if the excitation wavelength is 410 nm, the degree of excitation can be seen to be about half (about half or more) compared with the peak intensity near 470 nm.

That is, the excitation spectrum of the yellow light-emitting phosphor of the present invention may have an excitation ratio of 50% or more with respect to the peak at a wavelength of 410 nm.

Further, it can be seen that the degree of excitation does not decrease even at a shorter wavelength than 410 nm. That is, it can be seen that the excitation ratio is similar to 410 nm even at the wavelength of 400 nm.

That is, the excitation spectrum of the yellow light-emitting fluorescent substance of the present invention can have a higher excitation ratio than the YAG fluorescent substance in the wavelength band of 450 nm or less.

The near ultraviolet or blue light that excites the phosphor exhibits excellent excitation light toward shorter wavelengths. Thus, it can be seen that the present invention having excellent excitation in a short wavelength band is relatively excellent in characteristics as a phosphor.

This is because a near-ultraviolet or blue light acting as an excitation light tends to have an excellent intensity of light emission and a luminescent quality as it goes to a short wavelength, and a light emitting device (for example, LED) emitting such near- The center wavelength shifts to 450 nm or less.

For example, it can be seen that the yellow light emitting phosphor indicated by the dotted line has a remarkably reduced excitation degree toward a shorter wavelength, and the light conversion efficiency is lowered as the light emitting device which emits the excitation light becomes higher output.

However, it can be seen that the luminescent characteristics of the yellow light-emitting fluorescent material of the present invention can be further improved as the light-emitting element which emits the excitation light becomes higher in output.

<Examples>

Table 4 below shows the results of the experiment using a Lu ₃ Al ₅ O ₁₂ : Ce (LuAG) phosphor emitting light of 535 nm green wavelength (peak wavelength) band as the first phosphor, CRI and emission luminance when a yellow light emitting phosphor is realized by mixing a Ba ₂ Si ₅ N ₈ phosphor that emits light of an amber color wavelength (peak wavelength) band.

In this example, the results of measuring the color coordinates, CRI and emission luminance of each case while controlling the content of the first and second phosphors to 0 to 100 wt% are shown in Table 4. That is, the cases where the first phosphor is 0 wt% and the second phosphor is 100 wt% are sequentially shown from when the first phosphor is 100 wt% and the second phosphor is 0 wt%. Here, the content (%) represents the weight% (wt%).

The yellow phosphor to be compared is an example of a YAG fluorescent material. It can be seen that the YAG fluorescent material has CIE x and CIE y of 0.454 and 0.531, respectively, and a CRI of 36.5. At this time, the case where the light emission luminance of the YAG fluorescent material is set to 100 is shown.

As shown in Table 4, the yellow phosphor of the present invention has improved luminescence brightness in most cases compared to the conventional yellow phosphor. The luminescence brightness generally tends to increase as the content of the first phosphor increases.

Further, in the case of CRI, it can be seen that from the case where the first phosphor is 60 wt% and the second phosphor is 40 wt%, it is improved as compared with the conventional yellow phosphor. In the case of this CRI, the content of the second phosphor tends to increase as the content of the second phosphor increases.

Considering the results related to the CRI and the emission luminance, the ratio of the first phosphor and the second phosphor is changed from 60 wt% to 40 wt% (6: 4) to 40 wt% to 60 wt% (4: 6) It can be seen that the effect is the most excellent.

That is, the second phosphor may have an amount of 40 to 60 wt%, assuming that the sum of the first phosphor and the second phosphor is 100 wt%.

Among them, when the ratio of the first phosphor and the second phosphor is 50 wt% to 50 wt% (5: 5), the most excellent characteristic of the yellow light emitting phosphor is obtained when the CRI and the emission luminance are combined.

3 is a graph showing the emission spectrum of the yellow light-emitting fluorescent substance of the present invention.

The yellow light-emitting fluorescent substance of the present invention can realize yellow as a mixed light of amber light (chain _double- dashed line) caused by green light emission (one-dot chain line) attributed to Green phosphor and Ba ₂ Si ₅ N ₈ phosphor having 580 nm peak wavelength.

The spectrum of the yellow light of the present invention shown by the solid line in FIG. 3 is superior to that of the conventional yellow light (Yellow) by the yellow (YAG) phosphor indicated by the dotted line in the wavelength band and the emission intensity (luminance).

Also, referring to the spectrum of the wavelength band of about 500 nm to 570 nm, it can be seen that the CRI is greatly increased compared to the conventional yellow light (Yellow) by the YAG fluorescent substance. That is, it can be seen that the spectrum of this band has shifted to the longer wavelength side than the conventional yellow light (Yellow), and it can be seen that the CRI value is greatly improved by considering this in the color coordinates.

Furthermore, it can be clearly seen that the CRI is increased when considering the emission intensity at a level similar to that of the conventional yellow light (Yellow) (refer to FIG. 3, when the wavelength band is approximately 570 nm to 620 nm, It can be seen that the light emission intensity is higher than that of yellow light (Yellow), which contributes to improvement of luminance).

4 is a graph showing the emission spectrum when a white light emitting device (light emitting device package) is implemented using the blue light emitting element and the yellow light emitting phosphor of the present invention.

As shown in FIG. 4, it can be seen that yellow light emitted by the excitation of the yellow light emitting phosphor according to the present invention by the blue excitation light and the blue light is mixed with white light of good quality. It can be seen from the fact that the light of 580 nm wavelength band is greatly increased compared to other implementations.

That is, the white light generated by the yellow light-emitting phosphor of the present invention (Green + 580 nm Amber) exhibits improved light characteristics compared to the conventional yellow light-emitting phosphor (Yellow) and the comparative example described below (Green + 595 nm Amber) .

These are summarized in Table 5 below.

As can be seen from Table 5 above, when the relative luminous flux of the white light by the conventional yellow phosphor (yellow phosphor) is taken as 100%, the CRI at this time is about 64.8, The light increased to 112% and the CRI also increased to 68.3.

As described above, according to the present invention, the light intensity and the visibility (CRI) are excellent in the yellow emission band, and high-quality white light can be produced together with the near ultraviolet or blue light emitting device.

<Comparative Example>

Table 6 shows the emission spectrum of Lu ₃ Al ₅ O ₁₂ : Ce (LuAG) phosphors (hereinafter, referred to as "green phosphors") emitting light in the 535 nm green wavelength (peak wavelength) Alpha-SiAlON (hereinafter, referred to as an amber phosphor) that emits red light, and the emission luminance and CRI of the yellow light-emitting phosphor realized by mixing.

In this example, similarly to the case of Table 4, the results of measuring the chromaticity coordinates, CRI and emission luminance of each case while controlling the contents of the green phosphor and the amber phosphor to 0 to 100 wt% Lt; / RTI &gt; The yellow phosphor to be compared (Yellow phosphor) is an example of a YAG phosphor. Here, the content (%) represents the weight% (wt%).

As shown in Table 6, it can be seen that the yellow light-emitting fluorescent substance as a comparative example has a CRI characteristic relatively superior to that of the conventional yellow light-emitting fluorescent substance (YAG), but the light emission luminance is lowered. Further, it can be seen that the CRI is lowered in the section where the luminescence brightness is excellent.

&Lt; Light emitting device &

5 is a cross-sectional view showing an example of a light-emitting device using the yellow light-emitting fluorescent substance of the present invention. 5 illustrates an example of a lamp-type light emitting device package 100 according to an embodiment of the light emitting device of the present invention.

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 the light transmitting resin 150 is molded on the light emitting device 130. The light emitting device 130 may emit near ultraviolet light or blue light.

Further, a laser diode, a surface-emission 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. In the present invention, as a preferred application example, a nitride semiconductor light emitting diode is used. In FIG. 5, the light emitting device 130 is schematically represented, and both the horizontal and vertical nitride semiconductor light emitting diodes can be used.

7) may be dispersed in the light transmitting resin 150 and a covering member 160 may be provided on the light transmitting resin 150 to finish the external space of the entire device .

The phosphors 170 and 171 used herein may be configured such that other phosphors other than the yellow phosphor including the first phosphor 170 and the second phosphor 171 described above such as the red phosphor 172, . Two or more kinds of the dispersed phosphors 172 may be provided according to circumstances.

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

The light transmitting resin 150 may be entirely molded around the light emitting device 130, but may be partially molded at a light emitting portion as necessary.

That is, in the case of a high output light emitting device, uniform molding of the light emitting device 130 may result in uniform dispersion of the phosphors 170 and 171 dispersed in the light transmitting resin 150. In this case, it may be advantageous to partially mold the light emitting portion.

6 is a cross-sectional view showing another example of the light emitting device package using the yellow light emitting phosphor of the present invention. 6 shows the surface mount type light emitting device package 200. [

6, the surface mount type light emitting device package 200 according to an exemplary embodiment of the present invention includes lead frames 210 and 220 having positive and negative electrodes, and the lead frame 210 And 220, and generates light according to application of a voltage. The light emitting device 240 may use a light emitting diode or a laser diode.

Although FIG. 6 shows an example of the light emitting device 240 having a horizontal structure, it is needless to say that a vertical light emitting device can be used.

The light emitting device 240 is electrically connected to the lead frames 210 and 220 by a wire 250 and the light transmitting 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.

Further, the light-transmitting resin 260 may be formed by dispersing the fluorescent materials 270 and 271.

The phosphors 270 and 271 used herein may be mixed and dispersed in the first phosphor 270 and the second phosphor 271 described above, and other phosphors may be dispersed together. For example, red light-emitting phosphors 272 may be dispersed together. Two or more kinds of dispersed phosphors 272 may be provided according to circumstances.

As the light transmitting resin 260 used as a molding member, a light transmitting epoxy resin, a silicone resin, a polyimide resin, a urea resin, an acrylic resin, or the like can be used. Preferably, a light-transmitting epoxy resin or a light-transmitting silicone resin can be used.

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

The same elements as those described with reference to Fig.

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

FIG. 7 is a partially enlarged view of FIG. 5. Referring to FIG. 6 together, the process of realizing white light will be described below.

Blue light having a wavelength range of 400 to 480 nm corresponding to the near ultraviolet light or blue light emitted from the light emitting devices 130 and 220 passes through the phosphors 170, 171, 270 and 271. Here, some light excites the phosphors 170, 171, 270, and 271 to generate light having a main peak in the wavelength range of 500 to 600 nm as shown in FIG. 7, and the remaining light (a) It transmits blue light as it is.

As a result, white light having a spectrum of a wide wavelength of 400 to 700 nm is emitted.

The phosphors 170, 171, 270, and 271 may be formed by dispersing other phosphors in addition to the above-described oxynitride phosphors.

For example, the phosphors 170, 171, 270, and 271 may be used in combination with the phosphors (third phosphors) having emission peaks other than the yellow light-emitting phosphors described above.

It should be noted that the embodiments of the present invention disclosed in the present specification and drawings are only illustrative of specific examples for the purpose of understanding and are not intended to limit the scope of the present invention. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention are possible in addition to the embodiments disclosed herein.

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

Claims (13)

In the yellow light-emitting phosphor,
A first phosphor comprising at least one of Lu ₃ Al ₅ O ₁₂ : Ce and SrSi ₂ O ₂ N ₂ ; And
And a second phosphor which is mixed with the first phosphor to form a mixture and emits light including Ba ₂ Si ₅ N ₈ and excited by near ultraviolet light or blue light and having a center wavelength in the range of 550 to 590 nm Respectively,
Wherein the mixture of the first phosphor and the second phosphor is excited by the near ultraviolet light or the blue light to emit yellow light. The yellow light-emitting phosphor according to claim 1, wherein Eu substituted with Ba is used as an activator in the second phosphor. The yellow light emitting phosphor according to claim 2, wherein Eu is substituted with Ba in an amount of 0.05 to 0.2 mol. The yellow light emitting phosphor according to claim 1, wherein the excitation spectrum of the mixture of the first phosphor and the second phosphor has a higher excitation ratio than a YAG (Yttrium Aluminum Garnet) phosphor in a wavelength band of 360 to 460 nm. 5. The yellow light emitting phosphor according to claim 4, wherein the excitation spectrum of the mixture of the first phosphor and the second phosphor has an excitation ratio of 50% or more with respect to the peak at a wavelength of 410 nm. The yellow light-emitting phosphor according to claim 1, wherein the second phosphor has a content of 40 to 60 wt% based on 100 wt% of the sum of the first phosphor and the second phosphor. The yellow light-emitting phosphor according to claim 1, further comprising a third phosphor in a red wavelength band. In the light emitting device,
A light emitting element;
A first phosphor that is excited by light emitted from the light emitting device to emit green light; And
A second phosphor that emits light having a center wavelength in the range of 550 nm to 590 nm by being excited by the light emitted from the light emitting device, the _second phosphor including Ba ₂ Si ₅ N ₈ mixed with the first phosphor, And,
Wherein the mixture of the first phosphor and the second phosphor is excited by the near ultraviolet light or blue light to emit yellow light. The light emitting device according to claim 8, wherein the first phosphor comprises at least one of Lu ₃ Al ₅ O ₁₂ : Ce and SrSi ₂ O ₂ N ₂ . The light emitting device according to claim 8, wherein Eu substituted with Ba is used as an activator in the second phosphor. 11. The light emitting device according to claim 10, wherein Eu is substituted with Ba in an amount of 0.05 to 0.2 mol. 9. The light emitting device according to claim 8, wherein the second phosphor has an amount of 40 to 60 wt% based on 100 wt% of the sum of the first phosphor and the second phosphor. The light emitting device according to claim 8, further comprising a third phosphor in a red wavelength band.

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