KR101558556B1 - Phosphor, light emitting device, display apparatus and illumination apparatus - Google Patents

Abstract

The present invention includes an oxynitride having _a ? -Type Si ₃ N ₄ crystal structure and represented by a composition formula Si _{6 - z} Al _z O _z N _{8 -z} : Eu _a , M _b , wherein M is Sr (B) is in the range of 100 to 10000 ppm, the Al composition ratio (z) satisfies 0.1 < z < 1, To emit light having a peak wavelength in the range of 500 to 550 nm.

Description

TECHNICAL FIELD [0001] The present invention relates to a phosphor, a light emitting device, a display device,

The present invention relates to a phosphor, and particularly relates to a? -Sialon phosphor having high luminescence characteristics and excellent thermal and chemical stability, and a light emitting device, a planar light source device, a display device, and a lighting device using the same.

In general, a wavelength conversion phosphor material is used as a material for converting specific wavelength light of various light sources into desired wavelength light. In particular, light emitting diodes among various light sources can be advantageously applied as an LCD backlight, an automobile lighting, and a home lighting device due to low power driving and excellent light efficiency, and thus the fluorescent material has recently attracted attention as a core technology for manufacturing a white light LED.

The white light emitting device is usually manufactured by applying a yellow phosphor to a blue LED. More specifically, a yellow phosphor of YAG (Y ₃ Al ₅ O ₁₂ ): Ce is applied to a light emitting surface of a blue LED having a GaN / InGaN active layer to convert a part of blue light into yellow, Blue light is combined to provide white light.

A conventional white light emitting device composed of the above-described YAG: Ce phosphor (or TAG-based fluorescent material) -blu LED has a drawback that it has low color rendering. That is, since the wavelength of the white light obtained by using the yellow phosphor is only distributed in blue and yellow, the color rendering property is low, and there is a limit to realizing the desired natural white light.

Meanwhile, since the conventional wavelength-converting phosphor material is limited to the color of a specific light source and the color of a specific output light, and the color distribution that can be implemented is very limited, the color of light emitted from various light sources and / There is a limit to be applied.

In order to solve such a problem, the present applicant recently proposed a color rendering index (CRI) through a mixture of three specific blue, green and red phosphors in Korean Patent Application No. 2004-0076300 (filed on September 23, 2004) ), And further realized a wide color distribution. In order to realize an excellent light-emitting device through combination of such red, green and blue phosphors, each of the phosphors is required to have a high conversion efficiency.

In addition, the conventional silicate fluorescent substance is unstable to heat and has a drawback that it is vulnerable to a high output LED chip.

In order to improve this, a β-sialon phosphor has been studied for a long time since it was first proposed as a new fluorescent material called β-sialon (Japanese Laid-open Patent Application No. 60-206889 (published on October 18, 1985)).

In Japanese Patent Registration No. 3921545 (published on Mar. 3, 2007, patent owner: NATIONAL INSTITUTE FOR MATERIALS SCIENCE), β-sialon is proposed as a green light-emitting phosphor. However, since the luminance is very low and the wavelength and the color coordinate satisfy the desired white light, the characteristics are poor and it is difficult to put into practice.

On the other hand, a method of modifying the basic crystal structure of a? -Sialon phosphor to find new properties has also been reported. In the paper, Fluorescence of Eu + in SiAlONs (2005 Journal of the Ceramic Society of Japan, RJ Xie et al.) Proposes Sr sialon substituted with strontium (Sr) in place of Si or Al in the crystal structure. However, since Sr is substituted with a crystal structure, phase stabilization is somewhat lowered, and excellent thermal stability can not be expected.

In addition, although Korean Patent Laid-Open No. 2009-0028724 also proposes? -Sialon (SiAlON) as a green phosphor, there is a problem that dispersion of color coordinates depending on the product is large because the particle size is very large and the sedimentation speed is fast. In addition, there is a disadvantage that a high sintering temperature (2000 캜 or higher) and a long sintering time are required in comparison with sintering conditions (about 1600 캜, about 3 hours) of conventional silicate phosphors in the manufacturing process. These problems have made it difficult to add Group 1 and Group 2 elements as activators.

One of the objects of the present invention is to provide a phosphor and a manufacturing method for green light which is excellent in reproducibility and heat stability and can be used for a high output LED chip, .

Another object of the present invention is to provide a white light emitting device, a surface light source device, a lighting device, and a display device using the phosphor.

In order to realize the above-described technical problem, one aspect of the present invention,

type Si ₃ N ₄ crystal structure, and an oxynitride expressed by the composition formula Si _{6 - z} Al _z O _z N _{8 -z} : Eu _a , M _b , wherein M is selected from Sr and Ba (B) is in the range of 0.1 to 10 mol%, the Al composition ratio (z) satisfies 0.1 < z < 1, To emit light having a peak wavelength in the range of 500 to 550 nm.

The excitation source may have a peak wavelength in the range of 300 nm to 480 nm. In addition, the peak wavelength of the light emitted from the phosphor by the excitation irradiation may be 540 nm or less.

When the light emitted from the phosphor by the excitation light irradiation is represented by (x, y) values in CIE 1931 chromaticity coordinates, x and y can satisfy x? 0.336 and y? 0.637, respectively.

The change amount of y in the chromaticity coordinates of CIE 1931 of the light emitted from the phosphor may be -0.0065 or less. Here, the y change amount is y1 in the CIE 1931 chromaticity coordinates measured in the light emitted from the blue light emitting diode to which the phosphor is applied at 3.3 V and 120 mA, and the drive condition is 85 And y2 of the CIE 1931 chromaticity coordinates measured in the light emitted after continuous operation for 24 hours is defined as y2-y1.

In one example, M may be strontium (Sr). In this case, the amount of Sr added (a) may range from 0.5 to 3 mol%. Preferably, the Sr addition amount (a) may range from 1 to 1.5 mol%.

The Al composition ratio z may be in the range of 0.1 to 0.3. The Eu addition amount (b) may range from 0.9 to 3 mol%.

In another example, the M may include both barium (Ba) and strontium (Sr).

The particle size of the phosphor may have a D50 value in the range of 14.5 to 18.5 mu m.

In a specific example, the phosphor may further contain at least one element selected from the group consisting of Li, Na, K, Mg and Ca as an activator.

Here, the amount of Eu added (a) and the amount of M added (b) may be limited in ppm units. That is, the Eu addition amount (a) can be expressed in the range of 100 to 5000 ppm, and the M addition amount (b) can be expressed in the range of 100 to 10000 ppm, respectively.

According to another aspect of the present invention, there is provided a barium titanate zeolite having a _? -Type Si ₃ N ₄ crystal structure and having a composition formula Si _{6 - z} Al _z O _z N _{8 -z} : Eu _a , M _b wherein M is at least one selected from Sr and Ba, , The amount of Eu added is in the range of 0.1 to 5 mol%, the amount of M added is in the range of 0.1 to 10 mol%, and the Al composition ratio (z) satisfies 0.1 <z <1) Comprising the steps of: (a) measuring raw materials including Si-containing oxides or nitrides, Al-containing oxides or nitrides, Eu-containing compounds and M-containing compounds, and (b) mixing the raw materials except for the M- And a step of mixing the M-containing compound with the result of the first calcination of the pulverized product to prepare a second mixture, wherein the first calcination result is obtained by firstly calcining the first mixture and pulverizing the first calcination result, ; And secondary firing the secondary mixture and crushing the secondary firing result Step; provides the phosphor production process comprising a.

The first firing is performed at a temperature range of 1850 to 2300 ° C, and the second firing may be performed at a temperature lower than the first firing temperature. The primary and secondary firing may be performed in a nitrogen gas atmosphere.

The step of preparing the secondary mixture may include adding a compound containing at least one element selected from the group consisting of Li, Na, K, Mg and Ca as an activator together with the M-containing compound.

According to another aspect of the present invention, there is provided a light emitting device comprising: an LED chip emitting excitation light; a green phosphor disposed around the LED chip to wavelength-convert at least a part of the excitation light and including the? Sialon phosphor described above; And at least one light emitting element emitting light of a wavelength different from that of the green phosphor and provided by at least one of an additional LED chip and another kind of phosphor.

Here, the LED chip may be an LED chip emitting ultraviolet light or an LED chip emitting visible light having a peak wavelength larger than 470 nm.

Alternatively, the LED chip may be a blue LED chip having a peak wavelength in the range of 430 to 470 nm.

In this case, the at least one light emitting element may include a red phosphor. The emission wavelength peak of the red phosphor may be 600 to 660 nm, and the emission wavelength peak of the green phosphor may be 500 to 550 nm. Also, the blue LED chip has a half width of 10 to 30 nm, the green phosphor has a half width of 30 to 100 nm, and the red phosphor has a half width of 50 to 150 nm.

The emission wavelength peak of the green phosphor is 535 to 545 nm, and the half width of the emission wavelength may be 60 to 80 nm.

In the CIE 1941 color coordinate system, the color coordinates of light emitted from the red phosphor are in the range of 0.55? X? 0.65 and 0.25? Y? 0.35, and the color coordinates of light emitted from the blue LED chip are 0.1? X? 0.2, 0.02? Y? Lt; / RTI &gt;

In a specific example, the red phosphor is a nitride-based phosphor of M1AlSiN _x : Re (1? _X? 5), a sulfide phosphor of M1D: Re and a silicate-based phosphor of (Sr, L) ₂ SiO _{4 - x} N _y : Eu Wherein M is at least one element selected from among Ba, Sr, Ca, and Mg, D is at least one element selected from the group consisting of S, Se, and Te (where 0 <x < L is at least one element selected from the group consisting of Ba, Ca and Mg or at least one second group element selected from the group consisting of Li, Na, K, Rb and Cs. And Re may be at least one selected from Y, La, Ce, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, F, Cl,

The at least one light emitting element may further include a yellow to yellowish color phosphor. In this case, the yellow to yellowish color phosphors may be a garnet system, a sulfide system, or an? -SiAlON: Re phosphor of a silicate-based phosphor, YAG and TAG.

Meanwhile, the at least one light emitting element may be a red LED chip.

In one example, the LED chip may have a structure in which the first and second electrodes are arranged so as to face the same surface. In another example, the LED chip may have a structure in which the first and second electrodes are arranged so as to face each other, which are opposite to each other.

In yet another example, the LED chip has first and second main surfaces opposed to each other, each of the first and second conductivity type semiconductor layers providing the first and second major surfaces, and an active layer formed therebetween A semiconductor light emitting device comprising: a semiconductor laminate; a contact hole connected to one region of the first conductivity type semiconductor layer from the second main surface through the active layer; and a contact hole formed on a second main surface of the semiconductor laminate, A first electrode connected to the one region through the contact hole, and a second electrode formed on the second main surface of the semiconductor stack and connected to the second conductive semiconductor layer.

In this case, any one of the first and second electrodes may have a structure that is drawn out laterally of the semiconductor stacked body.

And a package body having a groove portion on which the LED chip is mounted.

And a resin packing portion for sealing the LED chip, wherein at least one of the plurality of phosphors may be dispersed in the resin package portion. Alternatively, the plurality of phosphors may form a plurality of different phosphor-containing resin layers, respectively, and the plurality of phosphor-containing resin layers may have a laminated structure.

The color rendering index (CRI) of the white light emitted from the white light emitting device may be 70 or more.

The present invention also provides a surface light source device, a display device, and a lighting device using the above-mentioned phosphor as a wavelength conversion material.

(for example, about 20%) than conventional? -sialon (SiAlON) phosphors by adding a predetermined amount of Sr to an empty sphere of a host matrix which is a? -sialon (SiAlON) crystal , It is possible to provide a green phosphor having a shorter wavelength.

These green phosphors can contribute to providing a clear white color by providing a color characteristic that can satisfy the green region of standard RGB (sRGB) in the CIE 1931 color coordinate system. Further, the doping of Sr contributes to the stabilization of? -Sialon, thereby improving the reliability characteristics, and in particular, it is possible to greatly reduce the change of the y color coordinate which influences the efficiency change with time, There is a big improvement effect.

Further, the? -Sialon phosphors proposed in the present invention can be used together with other phosphors such as blue and red phosphors to provide a light emitting device capable of expressing a wide color and having excellent reproducibility. Further, when realized with a white light emitting device, it is possible to provide excellent white light with greatly improved color rendering index.

The oxynitride phosphor according to the present invention can be advantageously applied to a white light emitting device, a planar light source device, a display device, and a lighting device according to various forms as a wavelength conversion material.

1 is a schematic view illustrating a crystal structure of a? -Sialon phosphor according to the present invention.
2 is an XRD graph of? -Sialon phosphors according to Example 1 and Comparative Example 1. Fig.
FIGS. 3 and 4 are photographs and photographs of the β-sialon phosphors according to Example 1 and Comparative Example 1, respectively, by using TOF-SIMS.
5 is a graph showing the luminance improvement effect of the? -Sialon phosphors according to Examples 1 to 4.
6 is a CIE 1931 color coordinate system for explaining the color coordinates and the time-lapse characteristics of light emitted from the phosphor.
7 is a graph showing the short-wavelength effect of the? -Sialon phosphors according to Examples 1 to 4.
8 is a graph showing the effect of improving the time-lapse characteristics (decrease in y color coordinate change) of the? -Sialon phosphors according to Examples 1 to 4.
9 is a graph showing the emission spectra of? -Sialon phosphors according to Comparative Examples 1 to 4.
10 is a graph showing the emission spectra of? -Sialon phosphors according to Examples 1, 6 and 7. FIG.
11 is a graph showing the emission spectra of? -Sialon phosphors according to Examples 8 to 13 and Comparative Examples 5 and 6. FIG.
12 is a graph showing intensity integral values and peak intensities of? -Sialon phosphors according to Examples 8 to 13 and Comparative Examples 5 and 6. FIG.
13 is a graph showing excitation spectra of? -Sialon phosphors according to Examples 8 to 13 and Comparative Examples 5 and 6. FIG.
14 is a graph showing emission spectra of? -Sialon phosphors according to Examples 14 to 23. FIG.
15 is a graph showing intensity integral values and peak intensities of? -Sialon phosphors according to Examples 14 to 23;
16 is a graph showing excitation spectra of? -Sialon phosphors according to Examples 14 to 23;
17 is a graph showing the peak intensity and the half-value width of? -Sialon phosphors according to Examples 14 to 23;
18 is a graph showing preferable particle size conditions of the? -Sialon phosphors according to the present invention.
19 is a schematic diagram showing a white light emitting device according to an embodiment of the present invention.
20 is a schematic view showing a white light emitting device according to another embodiment of the present invention.
21 is a schematic view showing a white light emitting device according to still another embodiment of the present invention.
22 is a spectrum of a green phosphor used in the present invention.
23A and 23B are spectra for the red phosphors employed in the present invention.
24A and 24B are spectra for yellow or yellowish-white phosphors employed in the present invention.
25 is a side sectional view schematically showing an LED light source module according to an embodiment of the present invention.
26 is a side cross-sectional view schematically showing an LED light source module according to another embodiment of the present invention.
27 is a side cross-sectional view showing an example of a light emitting device employable in a white light emitting device according to the present invention.
28 is a side cross-sectional view showing another example of a light emitting device that can be employed in the white light emitting device according to the present invention.
29 and 30 are a plan view and a side sectional view showing an example of a light emitting device which can be employed in the white light emitting device according to the present invention, respectively.
31 is a side cross-sectional view showing another example of a light emitting device that can be employed in the white light emitting device according to the present invention.
32A and 32B are schematic diagrams showing a backlight unit according to various embodiments of the present invention.
33 is a cross-sectional view showing a direct-type backlight unit according to an embodiment of the present invention.
34A and 34B are cross-sectional views showing an edge type backlight unit according to another embodiment of the present invention.
35 is an exploded perspective view showing a display device according to an embodiment of the present invention.

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

The phosphor according to one aspect of the present invention comprises an oxynitride having a? -Type Si ₃ N ₄ crystal structure and expressed by _a composition formula Si _{6 - z} Al _z O _z N _{8 -z} : Eu _a , M _b , The composition formula satisfies the following conditions.

1) M is at least one selected from Sr and Ba;

2) Eu added amount (a) ranges from 0.1 to 5 mol%;

3) The amount of M added (b) is in the range of 0.1 to 5 mol%; And

4) Al composition ratio (z) is 0.1 <z <1.

The phosphor according to the present invention can be excited by the wavelength up to the blue region over the ultraviolet region to provide green light emission. That is, the green phosphor is a phosphor that emits light having a peak wavelength in the range of 500 to 550 nm by irradiating an excitation source having a peak wavelength in the range of 300 nm to 480 nm. Particularly, in the case of the excitation light in the ultraviolet band, higher conversion efficiency can be expected.

As described above, the phosphor according to the present invention is characterized in that any one of Sr and Ba, or Sr and Ba is added to the host matrix Si _{6 - z} Al _z O _z N _{8 - z} having a β type Si ₃ N ₄ crystal structure, Based sialon-based phosphor.

As shown in FIG. 1, Sr (or Ba) added together with Eu is a form in which an element constituting the host matrix (for example, Si or Al) is not substituted and added as a dopant to an empty sphere . That is, in the present invention, the addition of Sr or Ba does not modify the host matrix (see FIG. 2).

M, which is at least one selected from Sr and Ba, is added to contribute to phase stabilization of the? -Sialon phosphor to improve reliability, improve light emission efficiency, and shorten wavelength.

The addition amount (b) of M may range from 0.1 to 5 mol%. When the Sr content is less than 0.1 mol%, the efficiency improvement effect and short wavelength effect are not sufficient. When the Sr content exceeds 5 mol%, the efficiency is lowered rather than the Sr-free phosphor. Preferably, the Sr addition amount (a) may range from 0.5 to 3 mol%. More preferably, the Sr addition amount (a) may be in the range of 1 to 1.5 mol%. In particular, since the luminance is improved to a level of 20% or more as compared with the case where M is not added, high conversion efficiency can be improved.

The phosphor according to the above composition formula can exhibit a tendency that the peak wavelength of light emitted from the phosphor by excitation irradiation is relatively short wavelengths of 540 nm or less. Therefore, it is possible to satisfy a relatively high level of the green wavelength characteristic required by the standard RGB. That is, when the light emitted from the phosphor by the excitation light source is represented by (x, y) values in CIE 1931 chromaticity coordinates, x and y can satisfy x? 0.336 and y? 0.637, Can be beneficially used.

As described above, since the M dopant employed in the present invention is added to the pores, it is possible to further stabilize the? -Sialon phosphor to thereby reduce the efficiency change over time. In general, the change in efficiency with time depends on the y color coordinate.

The y value of the CIE 1931 chromaticity coordinates measured in the light emitted when the phosphor is applied to the blue light emitting diode according to one measuring method and the driving starts at 3.3 V and 120 mA is defined as y1, Is defined as y2-y1 when the y value of the CIE 1931 chromaticity coordinates measured in the emitted light after continuous operation at 85 DEG C for 24 hours is y2. In this case, the amount of change in y in CIE 1931 chromaticity coordinates of the light emitted from the phosphor may be -0.0065 or less.

According to another aspect of the present invention, there is provided a method of manufacturing a phosphor as described above.

First, raw materials including Si-containing oxides or nitrides, Al-containing oxides or nitrides, Eu-containing compounds and M-containing compounds are measured to satisfy the desired stoichiometry required in the above composition formula.

Next, the raw materials except for the M-containing compound are mixed to prepare a primary mixture. Next, the primary mixture is firstly calcined, the primary calcination result is crushed / milled, and the crushed primary calcination result is mixed with the M-containing compound to prepare a secondary mixture. Next, the above-mentioned? -Sialon phosphors can be obtained by secondary firing the secondary mixture and pulverizing the secondary firing result. In addition, the obtained phosphor can be subjected to pickling treatment to enhance crystallization.

In the present invention, Sr can be added to the host matrix of? -Sialon using secondary firing treatment. In addition, this step can be smoothly carried out by performing second firing at a temperature lower than the first firing.

Particularly, since the second firing temperature is lower than the first firing temperature (1850 to 2300 ° C), the second firing is performed by mixing the compound containing the desired Group 1 and Group 2 elements with the first firing result, Additional Group 1 and Group 2 elements may be added as additional activators. This additional activator addition can contribute significantly to short wavelengths. These Group 1 and Group 2 elements may be at least one element selected from the group consisting of Li, Na, K, Mg, and Ca.

Hereinafter, each step example of the phosphor manufacturing method will be described in more detail.

Mixing of raw materials can be done by either dry or wet methods.

First, according to the wet mixing method, a ball and a solvent that help the mixing process and the pulverization of the raw material and the raw material are inserted and mixed. At this time, the balls may be made of silicon oxide (Si ₃ N ₄ ) or zirconia (ZrO ₂ ) material, or balls generally used in raw material mixing. The solvent may be any of alcohols such as DI water and ethanol, or organic solvents such as n-hexane. That is, the raw material, the solvent and the ball are inserted, the container is sealed, and the raw material can be homogeneously mixed for about 1 to about 24 hours by using a device such as a miller. After the mixing process is completed, the mixed raw material and the balls may be separated, and most of the solvent may be dried in a drying oven for about 1 to 48 hours. The dried powder can be uniformly classified into a desired micrometer size condition using a metal or polymer sieve.

On the other hand, according to the dry mixing method, the raw materials are homogeneously mixed using a milling machine by inserting raw materials into a container without using a solvent. The mixing time is about 1 to 24 hours, and the mixing time can be shortened by inserting the balls together with the raw material, thereby facilitating the mixing. Such a dry mixing method has an advantage in that the drying time of the solvent is not required compared with the wet method, thereby reducing the entire process time. Once the mixing of the raw materials is completed, the powder having been subjected to the mixing process as in the wet mixing can be uniformly classified into a desired micrometer size condition using a metal or polymer sieve. The grain size conditions of such a phosphor will be described later with reference to Fig.

In the firing process, the classified mixed powder can be filled in a boron nitride (BN) crucible and the firing process can be carried out. At this time, the firing process is performed using a heating furnace at a desired firing temperature (for example, 1850 to 2300 ° C, 1000 to 1800 ° C) for 1 to 24 hours. The atmosphere during the firing process may be a mixed nitrogen gas containing 100% of nitrogen (N ₂ ) or 1 to 10% of hydrogen. The synthesized phosphor powders are homogeneously pulverized using a pulverizer or a pulverizer, and then the post heat treatment process is repeated one to three times to improve the brightness of the phosphor.

Hereinafter, the present invention will be described in detail with reference to various examples.

( Example  One)

Raw material materials Si ₃ N ₄ , AlN, Al ₂ O ₃ , Eu ₂ O ₃ , and SrCO ₃ were weighed in stoichiometric ratios satisfying the composition ratios shown in Table 1 below to prepare raw material groups according to Example 1. In the raw material group, the remaining raw materials except SrCO ₃ are mixed with an ethanol solvent using a ball mill.

* The raw material mixture is volatilized with an ethanol solvent using a drier and filled with a dried primary raw material mixture in a boron nitride (BN) crucible. The primary raw material mixture is inserted into a boron nitride crucible filled with the heating, and the primary firing for 10 hours in the gas phase of the N ₂ atmosphere at 2050 ℃.

After grinding the result of the first firing, the weighed SrCO ₃ is added and the mixture is mixed with a miller. Subsequently, the secondary mixture was further fired at 1750 ° C to prepare a phosphor according to the composition ratio of Example 1. The produced phosphor was pulverized and subjected to a predetermined post heat treatment and a pickling process to obtain a final Si _{5 .8} Al _{0 .2} O _{0 .2} N _{7 .8} : Eu _{0 .0152} , Sr _{0 .01} β-sialon phosphors Respectively.

( Comparative Example  One)

The phosphor was pulverized in the same manner as in Example 1 and subjected to a post-heat treatment and a pickling process to obtain Si _{5 8} Al _{0 .2} O _{0 .2} N _{7 .8} : Eu _{0 .0152} was prepared.

First, the? -Sialon phosphors according to Example 1 and Comparative Example 1 were subjected to XRD analysis. The results are shown in the XRD graph of FIG.

As shown in Fig. 1, it can be confirmed that? -Sialon phosphors containing Sr (Example 1) and? -Sialon phosphors containing no Sr (Comparative Example 1) have the same crystal peaks. That is, the? -Sialon phosphors according to Example 1 and Comparative Example 1 all have the same? -Type Si ₃ N ₄ crystal structure.

As described above, it can be confirmed that Sr added in Example 1 did not affect the crystal structure.

Further, in order to confirm that Sr was added to Example 1, TOF-SIMS measurement for detecting the Sr concentration was performed.

In the graph of FIG. 3B (Comparative Example 1), Sr detection was not confirmed, but referring to FIG. 3A (Example 1), it was confirmed that Sr was doped (see the fourth chart). This can similarly be confirmed in FIGS. 4A and 4B which are qualitatively evaluated. That is, in FIG. 4B (Comparative Example 1), there is no Sr, whereas in FIG. 4A (Example 1), Sr exists.

According to the present measurement and detection results, it can be confirmed that Sr is not substituted with constituent elements in Example 1, but is doped into vacancies while maintaining the crystal structure.

division Al (z) Eu (a) Sr (b) Comparative Example 1 0.2 0.0152 none Example 1 0.2 0.0152 1 mol% Example 2 0.2 0.0152 1.5 mol% Example 3 0.2 0.0152 2 mol% Example 4 0.2 0.0152 3 mol% Example 5 0.2 0.0152 4 mol%

( Example  2 to 5)

Examples 2 to 5 were carried out in the same manner as in Example 1 except that Sr was added in an amount of 1.5 mol%, 2 mol%, 3 mol% and 4 mol%, respectively, so as to satisfy the composition ratio shown in Table 1 Alon phosphors were prepared.

The? -Sialon phosphors according to Examples 1 to 5 and? -Sialon phosphors according to Comparative Example 1 were measured for luminance along with the color coordinates and the emission spectrum (peak wavelength and half value width) in the excitation light source at 460 nm .

division
Color coordinates Peak wavelength
(Nm) Half full width
Luminance
(%) x y Comparative Example 1 0.3385 0.6352 540.6 51.0 100 Example 1 0.3344 0.6372 540.0 52.5 121.6 Example 2 0.3324 0.6398 539.5 52.0 123.5 Example 3 0.3273 0.6398 539.0 52.2 119.6

The luminance measurement results are shown in the graph of FIG. 5 together with Table 2 together with the luminance of Examples 1 to 5, with Comparative Example 1 in which Sr is not added as a reference (100). As shown in FIG. 5, it can be seen that the? -Sialon phosphors according to Examples 1 to 3 are improved in relative luminance to 20% or more than the? -Sialon phosphors of Comparative Example 1 in which Sr is not added. On the other hand, it was confirmed that the luminance increase was slightly reduced to 111.2% and 105% when the addition amount of Sr was 3 mol% and 4 mol% (Examples 4 and 5), respectively.

Therefore, in terms of the improvement of the luminance, that is, the efficiency, the addition amount of Sr can be set to 0.1 to 5 mol%, preferably 0.5 to 3 mol%, and more preferably, as shown in Examples 1 to 3, 1 to 1.5 mol%.

On the other hand, the color coordinates of the? -Sialon phosphors according to Examples 1 to 5 show distinct characteristics as compared with Comparative Example 1. That is, as shown in Table 2, the x value of the color coordinates of Examples 1 to 5 is lower than the x value of the? -Sialon phosphor of Comparative Example 1 (short wavelength) and the y value tends to be higher. In this connection, it was confirmed that in the case of the peak wavelength, all of Examples 1 to 5 were short-wavelengthed to 540 nm or less. Particularly, this tendency can be increased as the amount of Sr added increases as shown in Fig.

The color coordinates shown in Examples 1 to 5 provide the advantage of satisfying a high level of green light emission condition of sRGB. That is, in the CIE 1931 color coordinate system of FIG. 6, the green emission coordinates are generally as low as x and higher as y. The emission color coordinates of the? -Sialon phosphors according to Examples 1 and 2 were found to be advantageous as compared with Comparative Example 1 in that x was 0.336 or less and y was 0.637 or more.

Further, the? -Sialon phosphors according to Examples 1 to 5 can increase the phase stabilization by adding Sr, so that the change in conversion efficiency with the passage of time can be greatly reduced. In particular, such an efficiency change can be determined by a change in y color coordinate. Fig. 8 is a graph showing the y change amount in Examples 1 to 3 together with Comparative Example 1 as an effect of improving the aging characteristics.

In this experiment, the phosphor is applied to a blue light emitting diode (LED) having a wavelength of 460 nm and the driving voltage is set to 3.3 V and 120 mA. In this experiment, the CIE 1931 chromaticity coordinates y2 is defined as y2-y1 when y value is y1 and the y value of the CIE 1931 chromaticity coordinates measured in the light emitted after the drive condition is maintained for 24 hours at 85 DEG C is y2.

As a result, in the case of Comparative Example 1, it was as high as -0.0071, but in Examples 1 to 3 according to the present invention, the change amount of y in CIE 1931 chromaticity coordinates of the light emitted from the phosphor may be -0.0065 or less . The aging characteristics were also confirmed to be stabilized with higher Sr addition.

The following Comparative Examples 2 to 5 and Examples 6 and 7 were carried out in order to confirm the presence or absence of the effect when a composition other than Sr was added.

( Comparative Example  2 to 4)

In Comparative Examples 2 to 4, the same conditions and processes as in Example 1 were used, except that CaCO ₃ was used as a Ca-containing compound in place of SrCO ₃ , so that the composition ratios of Comparative Examples 2 to 4 in Table 3 were satisfied A? -Sialon phosphor to which 0.5 mol% of Ca, 1.0 mol% and 1.5 mol% of Ca were added was prepared.

( Comparative Example  5)

In Comparative Example 5, except that MgCO ₃ was used as the Ba-containing compound instead of SrCO ₃ , 1.0 mol of Mg was added to satisfy the composition ratio of Comparative Example 5 shown in Table 3 under the same conditions and process as those of Example 1 % Was added to prepare a? -Sialon phosphor.

( Example  6)

In this example, Sr and Ba were added to satisfy the composition ratio of Example 6 of Table 3 under the same conditions and processes as Example 1, except that BaCO ₃ , which is a Ba-containing compound, was used in addition to SrCO ₃ . To prepare a? -Sialon phosphor added in an amount of 0.5 mol%.

( Example  7)

In the present example, Ba and Ba were adjusted to satisfy the composition ratios of Example 7 of Table 3 by the same conditions and processes as Example 1, except that BaCO ₃ , which is a Ba-containing compound, was used in place of SrCO ₃ . mol% of? -sialon phosphors were prepared.

division Al (z) Eu (a) Additional dopant Kinds Addition amount (mol%) Comparative Example 1 0.2 0.0152 none none Comparative Example 2 0.2 0.0152 Ca 0.5 Comparative Example 3 0.2 0.0152 Ca 1.0 Comparative Example 4 0.2 0.0152 Ca 1.5 Comparative Example 5 0.2 0.0152 Mg 1.0 Example 6 0.2 0.0152 Sr, Ba 0.5, 0.5 Example 7 0.2 0.0152 Ba 1.0

The? -Sialon phosphors according to Examples 6 and 7 and the? -Sialon phosphors according to Comparative Examples 2 to 5 were evaluated for their chromaticity coordinates and luminance along with emission spectra (peak wavelength and half value width) in an excitation light source of 460 nm And the results are shown in Table 4. [Table 4]

division
Color coordinates Peak wavelength
(Nm) Half full width
Luminance
(%) x y Comparative Example 1 0.3385 0.6352 540.6 51.0 100 Comparative Example 2 0.3457 0.6272 541.5 55.4 75 Comparative Example 3 0.369 0.6052 541.5 61 54 Comparative Example 4 0.4132 0.5644 542.6 89 44 Comparative Example 5 0.3375 0.6356 540 52.7 90 Example 6 0.3328 0.6378 540 51.5 113.4 Example 7 0.3334 0.6375 540 51.5 116.3

First, in the case of Comparative Examples 2 to 5 in which Ca and Mg were added instead of Sr, the luminance of Comparative Example 1 was lowered to the standard (100) (see FIG. 9). Also, in the CIE 1913 color coordinates, the x value was rather large (long wavelength) and the y value was low, indicating an unfavorable trend.

However, the luminance was improved by 13.4% and 16.3%, similarly to the case of adding only Sr, which is the? -Sialon phosphor according to Examples 6 to 7 (refer to FIG. 10). In the CIE 1913 color coordinates, similarly to the foregoing embodiment, the x value was lowered (shorter wavelength) and the y value was higher.

In this way, it is not suitable to be used as an activator substituting for Sr in the case of Ca and Mg in terms of brightness and color coordinate, while a similar effect can be expected when Ba is used together with Sr or Ba is added instead of Sr Respectively.

The following Examples 8 to 13 and Comparative Examples 5 and 6 were conducted to confirm the conditions of the Al composition ratio (z).

( Example  8 to 13)

In the present embodiment, and were weighed so that the 0.1, 0.2, 0.3, 0.4, 0.5 and 1.0 (Examples 8 to 13 respectively) Al composition ratio (z) of AlN and Al ₂ O ₃ in the final phosphor, the primary raw material mixture The β-sialon phosphors were prepared under the same conditions and in the same manner as in Example 1, except that they were mixed together.

( Comparative Example  5 and 6)

In this comparative example, except that AlN and Al ₂ O ₃ were weighed so that the Al composition ratios (z) in the final phosphors were 1.5 and 2.0 (Examples 5 and 6, respectively) and mixed together in the primary raw material mixture 1, the? -Sialon phosphors were prepared under the same conditions and in the same manner as in Example 1.

When the? -Sialon phosphors according to Examples 8 to 13 and the? -Sialon phosphors according to Comparative Examples 5 and 6 were excited by a light source of 460 nm, the luminescence spectra were measured and shown in FIG. 11, and FIG. 12 And the intensity integral value and the peak intensity for the Examples and Comparative Examples.

11 and 12, in the case of Examples 8 to 13 in which the Al composition ratio (z) is 1 or less, the normalization strength is as high as about 0.8 or more, while the Al composition ratios (z) are 1.5 and 2.0, And 6 were somewhat lowered in luminance.

As a result, the Al composition ratio (z) is set to 0.01 to 1.0. Preferably, the Al composition ratio (z) is 0.1 to 0.3, and the highest peak is obtained at 0.23.

13 shows excitation spectra of? -Sialon phosphors according to Examples 8 to 13 and Comparative Examples 5 and 6 described above. As shown in FIG. 13, higher conversion efficiency can be expected in the ultraviolet band rather than the blue band (430 to 470 nm). Therefore, the present phosphor can also be usefully used in an apparatus using ultraviolet rays as an excitation light source.

Hereinbelow, Examples 14 to 23 were carried out in order to confirm the condition of the Eu addition amount (mol%).

( Example  14 to 23)

Eu ₂ O _{3 was added} to the final phosphor in such a manner that the Eu molar ratio (a) was 0.65, 0.98, 1.30, 1.52, 1.73, 1.95, 2.17, 2.38, 2.60 and 3.90 mol% (Examples 14 to 23, respectively) A? -Sialon phosphor was prepared in the same condition and in the same manner as in Example 1, except that the raw materials were weighed and mixed together in the primary raw material mixture.

14 shows the results of measurement of the luminescence spectrum when the? -Sialon phosphor according to Examples 14 to 23 was excited by a light source of 460 nm, FIG. 15 shows the intensity integral values for the respective Examples and Comparative Examples, It represents strength. The amount of Eu added (a) is set to 0.1 to 5 mol%. Considering the half-value width (see Fig. 17) along with the luminance, the Eu addition amount (a) is preferably in the range of 0.9 to 3 mol%.

16 shows excitation spectra of? -Sialon phosphors according to Examples 8 to 13 and Comparative Examples 5 and 6 described above. As shown in Fig. 13, high conversion efficiency can be expected in the ultraviolet band (especially 355 nm) rather than the blue band and near ultraviolet ray (especially 406 nm). Therefore, this phosphor can be effectively used in an illumination or display device employing ultraviolet rays as an excitation light source.

As described above, the? -Sialon phosphors proposed in the present invention can be advantageously applied to light emitting devices and various illumination and display devices. In such an application form, the phosphor may be used in combination with a transparent resin such as a silicone resin. When mixed with a transparent resin, the phosphor powder causes precipitation. For example, there is a problem that uneven distribution of the phosphor occurs due to sedimentation in the state of being accommodated in the syringe before being applied to the package or before curing after the application of the package, and the distribution of color coordinates increases depending on the package.

In order to reduce such color scattering, the degree of precipitation must be kept constant, and the phosphor powder is preferably uniform. It can be appropriately controlled through particle size among several factors.

The? -Sialon phosphors according to various embodiments of the present invention can also appropriately control the particle size distribution through a pulverization and classification process. The particle size distribution of the preferable? -Sialon phosphor shown in FIG. 17 is shown in a graph. A preferred particle size condition is a D50 value in the range of 14.5 to 18.5 mu m, more preferably in the range of 14 to 18 mu m. In addition, D10 may range from 8 to 11 [mu] m, and D90 may be from 23 to 25 [mu] m.

Hereinafter, various embodiments including a phosphor according to the present invention will be described with reference to the accompanying drawings.

19 is a schematic diagram showing a white light emitting device according to an embodiment of the present invention.

As shown in FIG. 19, the white light emitting device 10 according to the present embodiment includes a blue LED chip 15 and a resin packing portion 19 having a lens shape convex upward and packing the same.

The resin packing portion 19 adopted in the present embodiment is illustrated in a form having a hemispherical lens shape so as to secure a wide directivity. The blue LED chip 15 may be directly mounted on a separate circuit board. The resin packing portion 19 may be made of the silicone resin, the epoxy resin, or a combination thereof. The green fluorescent material 12 and the red fluorescent material 14 are dispersed in the resin packaging portion 19.

The green phosphor 12 that can be employed in the present embodiment may be an oxynitride phosphor represented by a composition formula of M _x A _y O _x N _{(4/3) y} , or an oxynitride phosphor represented by M _a A _b O _c N _{((2/3) a + (4/3) b- (2/3) c)} can be used. M is at least one kind of group II element selected from the group consisting of Be, Mg, Ca, Sr and Zn, and A is at least one element selected from the group consisting of C, Si, Ge, Sn, Ti, Zr and Hf It is a group IV element.

On the other hand, the red phosphor 14 that can be employed in the present embodiment is a nitride phosphor which is M1AlSiN _x : Re (1? _X? 5), an M1D: Re chalcogenide-based phosphor and (Sr, L) ₂ SiO _4-x N _y: Eu and the silicate-based phosphor (where, 0 <x <4, y = 2x / 3) of the selected at least one,

M is at least one element selected from among Ba, Sr, Ca and Mg; D is at least one element selected from S, Se and Te; L is at least one element selected from the group consisting of Ba, Ca and Mg; At least one element selected from the group consisting of Li, Na, K, Rb, and Cs; D is at least one selected from S, Se, and Te; Re is at least one element selected from the group consisting of Y, La At least one selected from Ce, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, F, Cl,

As described above, the present invention can provide a white light having a high color rendering index of 70 or more by providing a combination of a specific green phosphor and a specific red phosphor in consideration of a full width, a peak wavelength and / or a conversion efficiency. In addition, since light of a plurality of wavelength bands is obtained through a plurality of phosphors, color reproducibility can be improved.

In the case of the silicate-based phosphor of (Sr, L) ₂ SiO _{4 - x} N _y : Eu among the red phosphors, the x range may preferably be 0.15? X? 3. In the composition formula, a part of Si may be substituted with another element. For example, it may be substituted with at least one element selected from the group consisting of B, Al, Ga and In. Alternatively, at least one element selected from the group consisting of Ti, Zr, Gf, Sn and Pb .

The dominant wavelength of the blue LED chip may range from 430 to 470 nm. In this case, the emission wavelength peak of the green phosphor 12 is in the range of 500 to 550 nm in order to secure a broad spectrum in the visible light band and to improve the color rendering index, and the emission wavelength peak of the red phosphor 14 is And may range from 600 to 660 nm.

Preferably, the blue LED chip has a half width of 10 to 50 nm, the green phosphor has a half width of 30 to 200 nm, and the red phosphor has a half width of 50 to 250 nm.

In another embodiment of the present invention, in addition to the above-described red phosphor 12 and green phosphor 14, a yellow to yellowish color phosphor may be further included. In this case, a further improved color rendering index can be secured. This embodiment is shown in Fig.

20, the white light emitting device 20 according to the present embodiment includes a package main body 21 having a reflective cup formed at the center thereof, a blue LED chip 25 mounted on the bottom of the reflective cup, Includes a transparent resin packing portion 29 for sealing the blue LED chip 25.

The resin packaging portion 29 may be formed using, for example, silicone resin, epoxy resin, or a combination thereof. In the present embodiment, the resin packaging section 29 additionally includes the yellow phosphor or the yellow phosphor 26 in addition to the green phosphor 22 and the red phosphor 24 described in FIG.

In other words, in addition to the above-described? -Sialon phosphors, the green phosphor 22 may further include M _x A _y O _x N _{(4/3) y} oxynitride phosphors or M _a A _b O _c N _{((2/3) a + 4/3) b- (2/3) c)} oxynitride phosphors. The red phosphor 24 may be at least one selected from the group consisting of a nitride-based fluorescent material M1AlSiN _x : Re (1? _X? 5) and a chalcogen compound fluorescent material M1D: Re.

In addition, the third phosphor 26 is further included in this embodiment. The third fluorescent material may be a yellow to yellow fluorescent material capable of emitting light in a wavelength band located between the green and red wavelength bands. The yellow to yellowish color phosphors may be silicate-based phosphors, and the yellowish color phosphors may be phosphors of? -SiAlON: Re-based or YAG, TAG garnet.

In the above-described embodiment, the two or more kinds of phosphor powders are mixed and dispersed in a single resin packing area, but other structures may be modified in various ways. More specifically, the two or three kinds of phosphors described above may be provided in different layer structures. In one example, the green phosphor, the red phosphor and the yellow or yellowish color phosphor may be provided as a phosphor film of a multilayer structure by dispersing the phosphor powder at a high pressure.

Alternatively, as shown in FIG. 21, it may be implemented with a plurality of phosphor-containing resin layer structures.

21, the white light emitting device 30 according to the present embodiment includes a package body 31 having a reflective cup formed at the center thereof, and a blue LED 35 And a transparent resin packing portion 39 for sealing the blue LED 35 in the reflective cup.

A resin layer containing different phosphors is provided on the resin packaging portion 39. That is, the wavelength conversion portion 32 is formed by the first resin layer 32 containing the green phosphor, the second resin layer 34 containing the red phosphor, and the third resin layer 36 containing the yellow or yellowish- Lt; / RTI &gt;

The phosphor used in this embodiment may employ the same or similar phosphor as the phosphor shown and described in Fig.

The white light obtained through the combination of the phosphors proposed in the present invention can obtain a high color rendering index. That is, when a yellow phosphor is bonded to a blue LED chip, yellow light converted with blue wavelength light can be obtained. It is difficult to secure a color rendering index close to that of natural light since there is almost no wavelength light in the green and red bands in the entire visible light spectrum. In particular, since the converted yellow light has a narrow half width to obtain a high conversion efficiency, the color rendering index will be further lowered in this case. In addition, since the characteristics of white light expressed by a single degree of yellow conversion are easily changed, it is difficult to ensure excellent color reproducibility.

On the other hand, in the case of combining the blue LED chip, the green phosphor (G) and the red phosphor (R), the spectrum in the visible light band can be obtained because the light is emitted in the green and red bands as compared with the conventional example. The color rendering index can be greatly improved. In addition, the color rendering index can be further improved by further including a yellow or yellowish-color phosphor capable of providing an intermediate wavelength band between the green and red bands.

FIG. 22 shows an example of the emission spectrum for the green phosphor employed in the present invention. As shown in FIG. 22, it can be confirmed that the green phosphor obtained from the oxynitride phosphor according to the present invention has an emission spectrum with a peak wavelength of about 540 nm and a half width of 76.7 nm.

23A and 23B show emission spectra of red phosphors employed in the present invention.

Referring to Figure 23a, MAlSiN _x: the nitride-base phosphor Re (1≤x≤5) (where, M is at least one element selected from Be, Ba, Sr, Ca, Mg, Re is Y, La, At least one element selected from Ce, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, F, Cl, Br and I). The converted red light has a peak wavelength of about 640 nm and a half width of about 85 nm.

Referring to FIG. 23B, a chalcogen compound phosphor of MD: Eu, Re wherein M is at least one element selected from among Be, Ba, Sr, Ca and Mg and D is at least selected from among S, Re is at least one element selected from among Y, La, Ce, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, F, Cl, Is shown in FIG. The converted red light has a peak wavelength of about 655 nm and a half width of about 55 nm.

24A and 24B show spectra for a yellow or yellowish-red fluorescent material which can be selectively employed in the present invention.

Referring to FIG. 24A, a spectrum of a silicate-based phosphor is shown. The converted yellow light has a peak wavelength of about 555 nm and a half width of about 90 nm.

Referring to FIG. 24B, a spectrum of a phosphor of? -SiAlON: Re, where Re is Y, La, Ce, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Cl, Br and I, and Re is in the range of 1 ppm to 50000 ppm). The converted yellow light has a peak wavelength of about 580 nm and a half width of about 88 nm.

As described above, in the present invention, in consideration of the half-width, the peak wavelength, and / or the conversion efficiency, a specific combination of the green phosphor and the specific red phosphor or a combination of the yellow phosphor and the yellow- White light can be provided. The color coordinates of the red light in the light are in the range of 0.55? X? 0.65 and 0.25? Y? 0.35 in the x, y coordinates on the basis of the CIE 1941 color coordinate system. ? 0.4 and 0.5? Y? 0.7, and the chromaticity coordinates of the blue light are in the range where the x and y coordinates are in the range of 0.1? X? 0.2 and 0.02? Y?

When the main wavelength of the blue LED chip is in the range of 430 to 470 nm, the emission wavelength peak of the green phosphor is in the range of 500 to 550 nm, and the emission wavelength peak of the red phosphor is in the range of 600 to 660 nm. The emission wavelength peak of the yellow to yellowish color phosphor may range from 550 to 600 nm.

When the blue LED chip has a half width of 10 to 50 nm, the green phosphor has a half width of 30 to 200 nm, preferably 60 to 80 nm, and the red phosphor may have a half width of 50 to 250 nm. The yellow to yellow light phosphors may have a half width of 20 to 100 nm.

Through the selection and combination of the respective phosphors having such a condition, it is possible to secure a broad spectrum in the visible light band and to provide excellent white light having a higher color rendering index in the present invention.

The present invention can provide a white light source module which can be advantageously used as a light source of an LCD backlight unit. That is, the white light source module according to the present invention can be combined with various optical members (diffusion plate, light guide plate, reflector plate, prism sheet, etc.) as a light source of the LCD backlight unit to constitute a backlight assembly. 25 and 26 illustrate such a white light source module.

25, the light source module 50 for an LCD backlight includes an arrangement of a circuit board 51 and a plurality of white LED devices 10 mounted thereon. A conductive pattern (not shown) to be connected to the LED device 10 may be formed on the upper surface of the circuit board 51.

Each white LED device 10 can be understood as a white LED device shown and described in Fig. That is, the blue LED 15 is directly mounted on the circuit board 51 by a COB (Chip On Board) method. Each of the white LED devices 10 has a hemispherical resin packing portion 19 having no reflective wall and a lens function so that each white LED device 20 can exhibit a wide directivity angle have. The wide orientation angle of each white light source may contribute to reducing the size (thickness or width) of the LCD display.

Referring to Fig. 26, the light source module 60 for an LCD backlight includes an arrangement of a circuit board 61 and a plurality of white LED devices 20 mounted thereon. 20, the white LED device 20 includes a blue LED chip 25 mounted in a reflective cup of a package body 21 and a resin package 29 for encapsulating the blue LED chip 25, 29, the yellow or yellowish color phosphor 26 is dispersed and contained together with the green and red phosphors 22, 24.

The present invention can be implemented in various types of white light emitting devices using the above-described green phosphor as a wavelength change material. Hereinafter, a light emitting device employable in a white light emitting device according to the present invention will be described with reference to the accompanying drawings.

First, the semiconductor laminated structure of the light emitting device 100 shown in FIG. 27 may have the following structure. Al alloy substrate 101 and a protective layer 120 formed on the upper and lower surfaces of the Si-Al alloy substrate 101, a protective layer 120 formed on the protective layer 120, A reflective metal layer 103, a p-type semiconductor layer 104, an active layer 105, and an n-type semiconductor layer 106 are sequentially laminated on the substrate 100. [ The p-type and n-type semiconductor layers 104 and 106 and the active layer 106 are made of a GaN-based semiconductor, that is, Al _x Ga _y In _(1-xy) N (0? x? 1, 0? y? + y? 1) semiconductor material or the like, and forms a light emitting structure.

On the n-type semiconductor layer 106, an n-side electrode 107 is formed. The reflective metal layer 103 interposed between the junction metal layer 102 and the p-type semiconductor layer 104 further reflects upward the light incident from the semiconductor layer, thereby further increasing the brightness of the light emitting element. The reflective metal layer 103 may be made of a high reflectivity metal such as Au, Ag, Al, Rh, and a metal selected from the group consisting of two or more of these alloys. However, the reflective metal layer 103 may not be formed if necessary.

The bonding metal layer 102 serves to bond the Si-Al alloy substrate 101 to the light emitting structure, and Au or the like can be used. Although the light emitting device 100 of the present invention includes the junction metal layer 102 here, the Si-Al alloy substrate 101 may be directly bonded to the p-type semiconductor layer 104 without the junction metal layer 102 have. Therefore, the light-emitting device 100 of the present invention uses the Si-Al alloy substrate 101 as a conductive substrate.

Such Si-Al alloys are advantageous in terms of thermal expansion coefficient, thermal conductivity, mechanical workability, and price in Si-Al alloys. That is, the thermal expansion coefficient of the Si-Al alloy substrate 101 is similar to the thermal expansion coefficient of the sapphire substrate. Therefore, when the light emitting device 100 is manufactured by using the Si-Al alloy substrate 101, the warping of the substrate, which has occurred in the process of bonding the conductive substrate made of the conventional Si and the process of separating the sapphire substrate by laser irradiation And the occurrence of cracks in the light emitting structure are greatly reduced, so that a high-quality light emitting device 100 with few defects can be obtained.

In addition, the thermal conductivity of the Si-Al alloy substrate 101 is about 120 to 180 W / m 占 로서, which is excellent in heat radiation characteristics. In addition, since the Si-Al alloy substrate 101 can be easily manufactured by melting Si and AL at a high pressure, the Si-Al alloy substrate 101 can be easily manufactured, Can be easily obtained at low cost.

In particular, the light emitting device 100 of the present invention includes a protective layer 120 on the upper and lower surfaces of a Si-Al alloy substrate 101 to prevent chemical penetration during a cleaning process of the Si-Al alloy substrate 101 Respectively. Here, the protective layer 120 may be formed of a metal, a conductive dielectric, or the like. At this time, when the protective layer 120 is made of a metal, it may be made of at least two or more metals selected from the group consisting of Ni, Au, Cu, W, Cr, Mo, Pt, Ru, Rh, .

In this case, the protective layer 120 may be formed by an electroless plating method, metal deposition, sputtering, CVD or the like. At this time, the Si-Al alloy substrate 101 and the metal protective layer 120 A seed metal layer 110 serving as a seed in the plating process of the protective layer 120 may be further formed. The seed metal layer 110 may be made of Ti / Au or the like. When the protective layer 120 is formed of a conductive dielectric, the conductive dielectric may be made of ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), or CIO (Copper Indium Oxide). In this case, the protective layer 120 may be formed by vapor deposition, sputtering, or the like. The protective layer 120 is preferably formed to a thickness of not less than 0.01 μm and not more than 20 μm, and preferably not less than 1 μm and not more than 10 μm.

As described above, in the light emitting device employable in the white light emitting device of the present invention, a protective layer 120 such as Ni is additionally formed on the surface of the Si-Al alloy substrate 101, The Al metal of the Si-Al alloy substrate 101 is etched by a chemical such as HCl, HF, or KOH used in the process, or KOH used in a surface texturing process of the n-type semiconductor layer 106 There is an effect that it can be prevented.

Therefore, the light emitting device employable in the present invention can prevent the irregularities from being formed on the surface of the Si-Al alloy substrate 101, and cause the occurrence of defects such as peeling off of the light emitting structure bonded onto the Si-Al alloy substrate 101 Can be prevented.

When a metal such as Ni is used as the protective layer 120, the surface roughness of the Si-Al alloy substrate 101 is improved to firmly bond the Si-Al alloy substrate 101 to the light emitting structure There is an advantage to be able to. That is, conventionally, before the formation of the bonding metal layer 102, the Si-Al alloy substrate 101 is subjected to a cleaning process using chemicals such as acid for removing the natural oxide film, The surface of the Si-Al alloy substrate 101 is etched to form a surface irregularity with an average of 200 to 500 nm. However, as in the first embodiment of the present invention, a metal such as Ni is used as the protective layer 120 on the surface of the Si- The surface irregularities are reduced to 5 nm or less, and the surface roughness can be improved like a mirror surface.

As described above, since the surface roughness of the Si-Al alloy substrate 101 is improved, the bonding between the Si-Al alloy substrate and the light-emitting structure can be strengthened, and the bonding yield can be improved.

As another example of the light emitting device employable in the white light emitting device according to the present invention, the light emitting device shown in Fig. 28 can be provided.

28 is similar to the light emitting device shown in Fig. 27, but the protective layer 120 is not formed on the entire upper and lower surfaces of the Si-Al alloy substrate 101, but the Si-Al alloy substrate 101 And a conductive layer 122 is formed on the upper surface of the Si-Al alloy substrate 101 exposed by the protective layer 120 and the protective layer And the contact metal layer 123 is formed on the lower surface of the Si-Al alloy substrate 101. [

In particular, the protective layer 120 is preferably made of an insulating material, not a metal or a conductive dielectric. That is, in the light emitting device according to the second embodiment of the present invention, the protective layer 120 is formed of a Si-Al alloy substrate 101 on which the protective layer 120 is formed, instead of a metal or an insulating dielectric material, The protective layer 120 is formed to expose a part of the upper surface of the Si-Al alloy substrate 101 in order to energize the light emitting structure on the protective layer 120 and the light emitting structure on the protective layer 120, A conductive layer 122 is further formed on the upper surface of the Si-Al alloy substrate 101. Here, the conductive layer 122 may be formed of a metal or the like.

Meanwhile, the white light emitting device according to the present invention may employ a light emitting device in which the arrangement structure of the electrodes is changed to enable a high current operation, unlike the light emitting device of the above-described type. 29 and 30 are a plan view and a cross-sectional view showing a light emitting element as another example of the light emitting element that can be employed in the present invention. 30 is a cross-sectional view taken along line I-I 'of FIG.

29 and 30, the semiconductor light emitting device 200 includes a conductive substrate 210, a first electrode layer 220, an insulating layer 230, a second electrode layer 240, a second conductive semiconductor layer 250, an active layer 260, and a first conductive semiconductor layer 270. The respective layers are sequentially stacked.

The conductive substrate 210 may be made of a material capable of flowing electricity. For example, the conductive substrate 210 may be a metallic substrate including any one of Au, Ni, Cu, and W, or a semiconductor substrate including any one of Si, Ge, and GaAs. The first electrode layer 220 is electrically connected to the conductive substrate 210 and the active layer 260 to electrically connect the conductive substrate 210 And the active layer 260 and the contact resistance is minimized.

The first electrode layer 220 is stacked on the conductive substrate 210 and a part of the first electrode layer 220 is formed on the insulating layer 230 and the second electrode layer 240, The second conductivity type semiconductor layer 250 and the active layer 260 and extends through a contact hole 280 penetrating to a predetermined region of the first conductivity type semiconductor layer 270, The conductive substrate 210 and the first conductivity type semiconductor layer 270 are electrically connected to each other. That is, the first electrode layer 220 electrically connects the conductive substrate 210 and the first conductive type semiconductor layer 270, and electrically connects the conductive substrate 210 and the first conductive type semiconductor layer 270 through the contact hole 280, The first electrode layer 220 and the first conductivity type semiconductor layer 270 are in contact with each other through the contact hole 280. The first electrode layer 220 and the first conductivity type semiconductor layer 270 are in contact with each other.

The first electrode layer 220 may include an insulating layer 220 for electrically insulating the first electrode layer 220 from other layers except for the conductive substrate 210 and the first conductive semiconductor layer 270. [ Respectively. That is, the insulating layer 220 is formed between the first electrode layer 220 and the second electrode layer 240 as well as between the second electrode layer 240 exposed by the contact hole 280, And between the sides of the active layer 260 and the first electrode layer 220. The insulating layer 220 may be formed on a side surface of the first conductive semiconductor layer 280 through which the contact hole 280 penetrates.

The second electrode layer 240 is formed on the insulating layer 220. Of course, as described above, the second electrode layer 240 does not exist in certain regions through which the contact holes 280 pass. As shown in FIG. 30, the second electrode layer 240 may have at least one or more exposed regions, that is, a region where a part of the interfaces contacting the second conductive semiconductor layer 250 are exposed, that is, . And an electrode pad portion 247 for connecting an external power source to the second electrode layer 240 may be provided on the exposed region 245.

On the other hand, the second conductive semiconductor layer 250, the active layer 260, and the first conductive semiconductor layer 270, which will be described later, are not provided on the exposed region 245. 30, it is preferable that the exposed region 245 is formed at the edge of the semiconductor light emitting device 200 in order to maximize the light emitting area of the semiconductor light emitting device 200. The second electrode layer 240 may include one of Ag, Al, and Pt. The second electrode layer 240 may be electrically connected to the second conductive semiconductor layer 250 And has a function of minimizing the contact resistance of the second conductivity type semiconductor layer 250 and a function of reflecting light generated from the active layer 260 and directing the light toward the outside to increase the luminous efficiency Is preferably provided.

The second conductive semiconductor layer 250 may be disposed on the second electrode layer 240 and the active layer 260 may be disposed on the second conductive semiconductor layer 250, A layer 270 is provided on the active layer 260. At this time, the first conductive semiconductor layer 270 is an n-type nitride semiconductor and the second conductive semiconductor layer 250 is a p-type nitride semiconductor. The active layer 260 may be formed of different materials depending on the material of the first conductive semiconductor layer 270 and the second conductive semiconductor layer 250. That is, since the active layer 260 is a layer that emits energy by recombination of electrons / holes and emits light, the energy band gap of the first conductivity type semiconductor layer 270 and the second conductivity type semiconductor layer 250 It is preferable to form a material having a small energy band gap.

Meanwhile, unlike the light emitting device shown in FIG. 31, the first light emitting layer connected to the contact hole may be exposed to the outside.

31, the second conductivity type semiconductor layer 350, the active layer 360, and the first conductivity type semiconductor layer 360 are formed on the conductive substrate 310. In this case, the second electrode layer 340 may be disposed between the second conductive type semiconductor layer 350 and the conductive substrate 310. Unlike the previous embodiment, the second electrode layer 340 is not necessarily required.

The contact hole 380 having the contact region 390 in contact with the first conductivity type semiconductor layer 370 is connected to the first electrode layer 320 and the first electrode layer 320 is connected to the outside Exposed and has an electrical connection 345. An electrode pad portion 347 may be formed in the electrical connection portion 345. The first electrode layer 320 may be electrically isolated from the active layer 360, the second conductive semiconductor layer 350, the second electrode layer 340, and the conductive substrate 310 by the insulating layer 330.

The contact hole 380 is electrically separated from the conductive substrate 310 and is electrically connected to the first electrode layer 320 connected to the contact hole 380. In the present embodiment, ) Is exposed to the outside. Accordingly, the conductive substrate 310 is electrically connected to the second conductivity type semiconductor layer 340, and thus the polarity is different from that of the previous embodiment.

Therefore, such a light emitting device can maximize the light emitting area by partially forming the first electrode on the light emitting surface and placing the remaining part on the bottom of the active layer, and by arranging the electrodes arranged on the light emitting surface uniformly, Even if current is applied, the current can be uniformly distributed, and current concentration phenomenon can be mitigated in high current operation.

Thus, the light emitting device shown in Figs. 30 and 31 has the first and second conductive semiconductor layers having the first and second main surfaces opposed to each other and providing the first and second main surfaces, respectively, and the A contact hole connected to one region of the first conductivity type semiconductor layer through the active layer from the second main surface; and a contact hole formed on the second main surface of the semiconductor stacked body, A first electrode connected to one region of the conductive type semiconductor layer through the contact hole and a second electrode formed on the second main surface of the semiconductor stack and connected to the second conductive type semiconductor layer have. Here, a structure in which one of the first and second electrodes is drawn out in the lateral direction of the semiconductor stacked body may be employed.

32A and 32B are schematic views showing an example of a backlight unit according to various embodiments of the present invention.

Referring to FIG. 32A, an edge type backlight unit 1300 is shown as an example of a backlight unit to which the light emitting diode package according to the present invention can be applied as a light source.

The edge type backlight unit 1300 according to the present embodiment may include a light guide plate 1340 and an LED light source module 1310 provided on both sides of the light guide plate 1340.

The LED light source module 1310 may be provided on only one side of the light guide plate 1340 and the LED light source module 1310 may be provided on the other side of the light guide plate 1340. Alternatively, .

As shown in FIG. 32A, a reflection plate 1320 may be additionally provided under the light guide plate 1340. The LED light source module 1310 employed in the present embodiment includes a printed circuit board 1301 and a plurality of LED light sources 1305 mounted on the upper surface of the substrate 1301. The LED light source 1305 includes the above- A light emitting device package using a light emitting device is applied.

Referring to Fig. 32B, a direct-type backlight unit 1400 is shown as an example of another type of backlight unit.

The direct-type backlight unit 1400 according to the present embodiment may include a light diffusion plate 1440 and an LED light source module 1410 arranged on the lower surface of the light diffusion plate 1440.

The backlight unit 1400 illustrated in FIG. 32B may include a bottom case 1420 that can receive the light source module 1410 under the light diffusion plate 1440.

The LED light source module 1410 employed in the present embodiment includes a printed circuit board 1401 and a plurality of LED light sources 1405 mounted on the upper surface of the substrate 1401. The plurality of LED light sources 1405 may be a light emitting device package using the above-described phosphor as a wavelength conversion material.

In addition to the embodiments described above, the phosphors are not disposed directly in the package in which the LEDs are located, but may be disposed in other components of the backlight unit to convert light. Such an embodiment is shown in Figs. 33 to 34. Fig.

33, the direct-type backlight unit 1500 according to the present embodiment may include a phosphor film 1550 and an LED light source module 1510 arranged on the lower surface of the phosphor film 1550 .

The backlight unit 1500 illustrated in FIG. 33 may include a bottom case 1520 capable of receiving the light source module 1510. In the present embodiment, the phosphor film 1550 is disposed on the top surface of the bottom case 1520. [ At least a part of the light emitted from the light source module 1510 may be wavelength-converted by the phosphor film 1550. The phosphor film 1550 may be manufactured as a separate film, but may be provided in a form integrated with the light diffusion plate.

Here, the LED light source module 1510 may include a printed circuit board 1501 and a plurality of LED light sources 1505 mounted on the upper surface of the substrate 1501.

34A and 34B show an edge type backlight unit according to another embodiment of the present invention.

The edge type backlight unit 1600 shown in FIG. 34A may include a light guide plate 1640 and an LED light source 1605 provided on one side of the light guide plate 1640. The LED light source 1605 may be guided to the inside of the light guide plate 1640 by the reflective structure 1620. In this embodiment, the phosphor film 1650 may be positioned between the side of the light guide plate 1640 and the LED light source 1605. [

The edge type backlight unit 1700 shown in Figure 34B may include a light guide plate 1740 and an LED light source 1705 and a reflective structure 1720 provided on one side of the light guide plate 1740, . In the present embodiment, the phosphor film 1750 is illustrated as being applied to the light emitting surface of the light guide plate 1740.

As described above, the phosphor according to the present invention is not directly applied to an LED light source, but may be implemented in a form applied to another device such as a backlight unit.

35 is an exploded perspective view showing a display device according to an embodiment of the present invention.

The display device 2400 shown in Fig. 35 includes a backlight unit 2200 and an image display panel 2300 such as a liquid crystal panel. The backlight unit 2200 includes a light guide plate 224 and an LED light source module 2100 provided on at least one side of the light guide plate 2240.

The backlight unit 2200 may further include a bottom case 2210 and a reflection plate 2220 disposed under the light guide plate 2120. The reflection plate 2220 may be a reflective plate.

In addition, various kinds of optical sheets 2260 such as a diffusion sheet, a prism sheet, or a protective sheet may be disposed between the light guide plate 2240 and the liquid crystal panel 2300 according to various optical characteristics.

The LED light source module 2100 includes a printed circuit board 2110 provided on at least one side of the light guide plate 2240 and a light guide plate 2210 mounted on the printed circuit board 2110, And a plurality of LED light sources 2150. The plurality of LED light sources 2150 may be the light emitting device package described above. The plurality of LED light sources employed in the present embodiment may be a side view type light emitting device package in which the side surface adjacent to the light emitting surface is mounted.

As described above, the above-described phosphors can be applied to an LED light source module that is applied to packages of various mounting structures to provide various types of white light. The light emitting device package or the light source module including the light emitting device package described above may be applied to various types of display devices or lighting devices.

The present invention is not limited by the above-described embodiments and the accompanying drawings, but is intended to be limited only by the appended claims. It will be apparent to those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. something to do.

Claims (40)

a? -type Si ₃ N ₄ crystal structure, and an oxynitride represented by _a composition formula Si _{6 -z} Al _z O _z N _{8 -z} : Eu _a , M _b ,
(B) is in the range of 100 to 10000 ppm, and the Al composition ratio (z) is in the range of 0.1 < z < 1,
And irradiating an excitation circle to emit light having a peak wavelength in the range of 500 to 550 nm, wherein M is added as an additive to an empty sphere of a? Si ₃ N ₄ crystal structure as a dopant.
The method according to claim 1,
The excitation source has a peak wavelength in the range of 300 nm to 480 nm,
Wherein a peak wavelength of light emitted from the phosphor by the excitation irradiation is 540 nm or less.
delete The method according to claim 1,
(X, y) in CIE 1931 chromaticity coordinates, x and y satisfy x? 0.336 and y? 0.637, respectively, when light emitted from the phosphor by the excitation irradiation is represented by
The method according to claim 1,
A change amount of y in CIE 1931 chromaticity coordinates of light emitted from the phosphor is -0.0065 or less,
The y change amount is defined as y1 of the CIE 1931 chromaticity coordinates measured from the light initially emitted under the condition that the phosphor is applied to the blue light emitting diode and driven at 3.3 V and 120 mA, And y2 is the y value of the CIE 1931 chromaticity coordinates measured in the light emitted after the phosphor is continuously applied for 24 hours.
The method according to claim 1,
And M is strontium (Sr).
The method according to claim 1,
Wherein a particle size of the phosphor has a D50 value in a range of 14.5 to 18.5 mu m.
An LED chip emitting an excitation light;
A green phosphor disposed around the LED chip to wavelength convert at least a part of the excitation light and comprising the phosphor according to any one of claims 1, 2, and 4 to 7; And
And at least one light emitting element emitting light of a wavelength different from that of the LED chip and the green phosphor and provided by at least one of an additional LED chip and another kind of phosphor.
A display device using the phosphor according to any one of claims 1, 2, and 4 to 7 as a wavelength conversion material.
A lighting device using the phosphor according to any one of claims 1, 2, and 4 to 7 as a wavelength conversion material.
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