KR101059119B1 - White light emitting diode having high color rendering properties - Google Patents

Abstract

PURPOSE: White light emitting diodes are provided to exhibit a high color rendering property with a high color rendering index as well as a correlated color temperature by further including the phosphor of a specific composition to a yellow phosphor. CONSTITUTION: White light emitting diodes comprise a blue excitation light source and a phosphor. The phosphor includes a phosphor having a light emitting wavelength of 550~600 nm, an oxynitride-based phosphor represented by chemical formula 1: BaSi2O2N2 : xEu^(2+), and a phosphor having a light emitting wavelength of 600~650 nm. The phosphor is one or more selected from Sr_(3-x)SiO_5 : yEu^(2+)(0 < x <=1, 0 < y <=1), SiAlON : Eu^(2+), and chemical formula 2: yCe^(3+).

Description

WHITE LIGHT EMITTING DIODE HAVING HIGH COLOR RENDERING PROPERTIES}

The present invention relates to a white light emitting diode, and more particularly to a white light emitting diode including a specific phosphor to implement a high color rendering white light.

Light emitting diodes (LEDs) are high-efficiency and eco-friendly light sources, and are attracting attention in various fields. Light emitting diodes (LEDs) are used in many fields, for example, in displays (display devices), optical communications, automobiles, and general lighting. In particular, the demand for white light emitting diodes that implement white light is increasing.

There are three methods for manufacturing a white light emitting diode. First, red, blue, and green LED chips are mounted in one package and white chips are controlled by controlling each chip. (Prior Art 1) Second, red, blue, and green LEDs are used in an ultraviolet (UV) LED chip. (2nd conventional technology) Third, a method of implementing white light by applying a phosphor having yellow light emitting property to a blue light emitting diode chip (3rd conventional technology).

Among them, the first conventional technology, that is, the method using the red, blue, and green LED chips, respectively, has an uneven operating voltage, and the output of each chip varies according to the ambient temperature, so that the color coordinates change. As a result, it is difficult to uniformly mix the respective colors, making it difficult to obtain pure white light. In addition, a separate operation circuit is required in consideration of the electrical characteristics of each chip or light emitting diode, and since it must be controlled, it is not only complicated in the manufacturing process or operation method, but also inefficient in terms of power consumption to realize high brightness white light. It was.

Therefore, generally, the second method (second conventional technology) and the third method (third conventional technology) are preferred. Specifically, most white light emitting diode manufacturers prefer to apply a mixture of red, blue, and green phosphors in a proportion to a UV light emitting diode chip, or to apply a yellow phosphor to a blue light emitting diode chip. have. This method is simpler and more economical than the method using the red, blue and green LED chips, respectively. In addition, since variable mixed color is possible using light emitted from the phosphor, it is easy to match color coordinates, and various colors may be realized.

In particular, the method of applying a yellow phosphor to a blue light emitting diode chip (the third conventional technology) has a simpler manufacturing process than the method of using three phosphors, namely, the second conventional technology, and the color coordinates. There is an advantage that it is easy to adjust. And luminous efficiency (lm / W) is high. In this case, the yellow phosphor is a phosphor showing an emission peak in the region of about 550 nm to 600 nm, which is mainly used as an oxide-based yttrium aluminum garnet (hereinafter referred to as 'YAG'). Represented by the chemical formula (composition formula) of Ce ^{3 +:} the YAG-base phosphor is Y ₃ Al ₅ O _12, and active agent (activator), usually by Y ₃ Al ₅ O _12, including the rare earth elements Ce (three Solarium) as a matrix do. The YAG-based phosphor is excited by a blue light emitting diode chip (excitation light source), thereby realizing high brightness white light through combination with blue (combination of blue and yellow) emitted from the blue light emitting diode chip. White light emitting diodes using such YAG-based phosphors are also presented in various prior patent documents.

For example, Korean Patent No. 10-0456430 discloses a method for producing a YAG-based phosphor, and Korean Patent Nos. 10-0628884 and 10-0448416 disclose gallium nitride that emits blue light at a 460 nm region. a technique for implementing white light is given by the: (Ce ^{3 +} YAG) phosphor diode chip (GaN LED chip) with, YAG-based light emission to yellow.

However, the YAG-based phosphor can realize high luminance white light by the blue excitation light source, but it is difficult to obtain excellent color rendering (color rendering index) because the light emission intensity of the red region is relatively weak due to the characteristics of the emission wavelength. In order for a white light emitting diode to be used as a general lighting, it has a high luminous efficiency (lm / W) compared to a general lighting such as a fluorescent lamp, and has a high correlated color temperature (CCT) and color rendering index (CRI). It is required to have

In general, the correlated color temperature (CCT) and color rendering index (CRI) are used as performance indicators for evaluating the characteristics of white light. The higher the correlation color temperature (CCT), the more dazzling and blue the white light becomes. The higher the color rendering index (CRI), the more white light close to sunlight (natural light) is achieved. In particular, the color rendering index (CRI) is used as an important indicator for evaluating the performance of white light. The color rendering index (CRI) represents the degree to which the color of the object is different when irradiated with sunlight and when irradiated with artificial light sources (lights, etc.), which is defined as 100 when the object is irradiated with sunlight. do. That is, the color rendering index (CRI) is an index indicating how close the object's color is to sunlight when irradiated with sunlight under an artificial light source, and is represented by a value between 0 and 100. Currently, the color rendering index (CRI) of incandescent lamps on the market is about 80 or more, and the color rendering index (CRI) of fluorescent lamps is about 75 or more.

However, the color rendering index (CRI) of the conventional white light emitting diode is about 70 to 75, which is lower than that of general lighting. In addition, conventional white light emitting diodes are sensitive to color temperature and are not suitable for light sources such as general lighting or LCD color background. As described above, the conventional white light emitting diode using the YAG-based phosphor has a low correlation color temperature (CCT) and color rendering index (CRI).

Accordingly, an object of the present invention is to provide a high color rendering white light emitting diode having a high color rendering index (CRI) as well as a correlated color temperature (CCT) by further including a phosphor having a specific composition in the yellow phosphor.

More specifically, an object of the present invention is to provide a high color rendering white light emitting diode having a correlation color temperature (CCT) of 6,000 K or more, a color rendering index (CRI) of 80 or more, preferably a color rendering index (CRI) of 90 or more.

The present invention to achieve the above object,

Including blue excitation light sources and phosphors,

The phosphor is,

Phosphor (a) having a light emission wavelength of 550 to 600 nm; And

Provided is a white light emitting diode comprising the oxynitride-based phosphor represented by Formula 1 below.

[Formula 1]

BaSi ₂ O ₂ N ₂ : xEu ^{2 +}

(In Formula 1 above, x is 0 <x ≦ 1.0.)

The phosphor further includes a phosphor (c) having a light emission wavelength of 600 to 650 nm and / or a phosphor (d) having a light emission wavelength of 500 to 550 nm.

According to the present invention, including a phosphor having a light emission peak of 550 to 600 nm and an oxynitride-based phosphor having a specific composition represented by Formula 1, it has a high color rendering index (CRI) of 80 or more as well as a correlated color temperature (CCT). In particular, when the emission peak further includes a phosphor having a 600 ~ 650nm, the red region is complemented to have a high color rendering index (CRI) of 90 or more.

1 to 3 are graphs showing the results of measuring Luminescence Intensity of a white light emitting diode according to an exemplary embodiment of the present invention.

Hereinafter, the present invention will be described in detail.

The white light emitting diode according to the present invention includes a blue excitation light source and a phosphor as a wavelength conversion material. The phosphor is excited by a blue excitation light source and emits light. The white light emitting diode according to the present invention implements white light by combining a blue color emitted from a blue excitation light source and a color emitted from a phosphor. And, as described below, not only has a high correlation color temperature (CCT), but also high color rendering index (CRI) of 80 or more, preferably high color rendering index (CRI) of 90 or more.

The blue excitation light source is not limited as long as it is a light source that emits (emits) blue light. The blue excitation light source may be selected from, for example, a blue light emitting diode chip, a blue organic light emitting diode chip, an blue laser diode chip, and a light source emitting other blue light. have. For example, the blue excitation light source may use a gallium nitride diode chip (GaN LED chip) emitting blue light. In this case, the emission wavelength of the blue excitation light source may have a main peak in the 350 nm to 480 nm region, preferably in the 400 nm to 480 nm region.

According to the present invention, the above phosphor is (a) a phosphor having a light emission wavelength of 550 to 600 nm (hereinafter abbreviated as "phosphor (a)"); And (b) an oxynitride-based phosphor represented by Formula 1 below (hereinafter, abbreviated as "phosphor (b)").

[Formula 1]

BaSi ₂ O ₂ N ₂ : xEu ^{2 +}

(In Formula 1 above, x is 0 <x ≦ 1.0.)

The phosphor (a) has a light emission wavelength of 550 to 600 nm, which is not limited as long as it shows a main peak in the wavelength range. Specifically, the phosphor (a) may be excited by a blue excitation light source in the wavelength region and emit light in yellow, yellow, or orange color. The phosphor (a) is preferably emitted in the region of 550 to 580 nm and may emit yellow or yellow light. As the phosphor (a), for example, one or more selected from silicates and oxides can be used. For example, the phosphor (a) is a silicate phosphor emitting yellow light, and Sr _{3 - x} SiO ₅ ^{: YEu 2 + (0 <x} ≤1, 0 <y ≤1) or SiAlON: Eu ^{2 +} can be used with such composition. According to a preferred embodiment, the phosphor (a) may use an oxide-based phosphor represented by the following formula (2). The phosphor of Formula 2 emits yellow or yellow light, which is excellent in luminous efficiency and thus may be usefully used as the phosphor (a) of the present invention.

[Formula 2]

Y ₃ A ₅ O ₁₂ : yCe ^{3 +}

(In Formula 2, A is one or more selected from Al, Ga, and Ge, and y is an integer or prime number greater than zero.)

In this case, in Formula 2, the parent Y ₃ A ₅ O ₁₂ is Y ₃ Al ₅ O ₁₂ (A = Al, YAG), Y ₃ Ga ₅ O ₁₂ (A = Ga), Y ₃ Ge ₅ O ₁₂ (A = Ge), or Y ₃ (Al, Ga) ₅ O ₁₂ (A = a mixture of Al and Ga, that is, a portion of Al is replaced with Ga). The composition ratio x (atomic fraction) of the activator (rare earth element) Ce to the parent Y ₃ A ₅ O ₁₂ is not limited as long as it is an integer or prime number larger than 0, but preferably 0.001 ≦ y ≦ 1.0.

On the other hand, the phosphor (b), that is, the oxynitride-based phosphor represented by the formula (1) improves the correlated color temperature (CCT) and color rendering index (CRI). The phosphor (b) emits blue-green light, which preferably has a light emission wavelength of 480 nm to 520 nm. That is, the phosphor (b) emits cyan by showing a main peak in the wavelength region. More preferably, the phosphor (b) has a light emission wavelength of 490 to 500 nm, most preferably 495 ± 3 nm.

The phosphor (b) of Chemical Formula 1 has a composition ratio of 1: 2: 2: 2 in the composition ratio of each element constituting the parent BaSi ₂ O ₂ N ₂ . That is, it has a composition ratio of Ba: Si: O: N = 1: 1: 2: 2. In the phosphor (b) of Chemical Formula 1, the composition ratio x of europium (Eu), which is an activator to the parent BaSi ₂ O ₂ N ₂ , is an integer or a minor number, and the composition ratio x of Eu is preferably 0.001 ≦ x ≦ 0.4. Do. The composition ratio x of Eu is more preferably 0.01 ≦ x ≦ 0.2. As the composition ratio x of Eu is a preferable range, as described above, when 0.001 ≦ x ≦ 0.4 (more preferably, 0.01 ≦ x ≦ 0.2), for example, luminescence intensity may be improved. Phosphor (b) of Formula 1 is excited by the blue-green wavelength by the blue excitation light source to complement the blue-green color of the light emitting diode to improve the correlation color temperature (CCT), in particular the color rendering index (CRI).

According to the present invention, white light is realized by a combination of blue light emitted from the blue excitation light source and yellow (or yellow) light emitted from the phosphor (a), and the phosphor (b) having a specific composition represented by Chemical Formula 1 is Complementing cyan improves the correlated color temperature (CCT) and color rendering index (CRI). Specifically, in the conventional case using only the phosphor (a), when the correlation color temperature (CCT) is less than 6,000K (approximately 5,800K), in addition to the phosphor (b) represented by the formula (1) according to the present invention , At least 6,000K, preferably at least 7,000K, having a high correlation color temperature (CCT). Particularly, in the color rendering index (CRI), in the conventional case using only the phosphor (a), it is lower than general lighting (incandescent lamp, fluorescent lamp, etc.) as 75 or less, but according to the present invention, the phosphor (b) When further comprises, has a high color rendering index (CRI) of 80 or more as equivalent or more than the general lighting.

According to a preferred embodiment of the present invention, the phosphor further includes (c) a phosphor having a light emission wavelength of 600 to 650 nm (hereinafter abbreviated as "phosphor (c)"). That is, in the present invention, the phosphor further includes a phosphor (c) in addition to the above-described phosphor (a) and the phosphor (b).

The phosphor (c) has a light emission wavelength of 600 to 650 nm, which is not limited as long as it shows a main peak in the wavelength range. Specifically, the phosphor (c) may be excited by a blue excitation light source in the wavelength region and emit light in red. The phosphor (c) is not limited as long as it emits red light, and may be selected from, for example, a sulfide-based red phosphor. Specific example, phosphors (c), (Ca, Sr) S: the composition having a CaAlSiN sulphide based or Eu ^{2 +} _3: may be a red phosphor of the nitride-silicate having a composition of Eu ^{2 +.}

According to the present invention, when the phosphor (c), that is, the phosphor further includes a red phosphor having a light emission wavelength of 600 to 650 nm, the red region may be supplemented to achieve high color rendering of CRI 90 or higher. In addition, the luminescence intensity is improved, and it is possible to have a high correlation color temperature (CCT) of 7,000K or more.

In addition, according to another preferred embodiment of the present invention, the phosphor further includes (d) a phosphor having a light emission wavelength of 500 to 550 nm (hereinafter, abbreviated as "phosphor (d)"). That is, in the present invention, the phosphor further includes a phosphor (d) in addition to the above-described phosphor (a) and the phosphor (b). In another embodiment, the phosphor may include four phosphors, a phosphor (a), a phosphor (b), a phosphor (c), and a phosphor (d).

The phosphor d has a light emission wavelength of 500 to 550 nm, which is not limited as long as it exhibits a main peak in the wavelength range. Specifically, the phosphor d may be excited by a blue excitation light source in the wavelength region and emit light green. The phosphor d is not limited as long as it emits green light, and may be selected from, for example, a sulfide-based green phosphor. Specific example, phosphors (d), _{Sr 1-x Ga 2 S 4} : based or sulfide having a composition ^{yEu 2 + (0.001≤ x <1} , 0.001≤ y ≤1), SrSi 2 O 2 N 2: Eu 2 ^An oxynitride-based green phosphor having a composition of ⁺ can be used.

According to the present invention, when the phosphor (d) is further included, that is, when the emission wavelength further includes a green phosphor having a wavelength of 500 to 550 nm, color rendering higher than when using two kinds of the phosphor (a) and the phosphor (b) Has an index (CRI).

The white light emitting diode according to the present invention includes a blue excitation light source and the phosphor as described above, but may be manufactured in a conventional structure. The white light emitting diode according to the present invention includes, for example, a substrate, a blue excitation light source (eg, a blue light emitting diode chip such as a gallium nitride diode chip) disposed on the substrate, and a pair of blue excitation light sources. Electrodes (anode and cathode). The phosphor may be molded on a blue excitation light source. The molding may be molded by forming a light transmissive resin and a phosphor in a proper amount as usual.

The light transmissive resin is not particularly limited as long as it has light transmittance and adhesiveness. The light transmissive resin may be, for example, one or more polymers selected from epoxy resins, silicone resins, urethane resins, acrylic resins, and the like, but is not limited thereto. And these polymers have good transparency.

In addition, the phosphor includes at least the phosphor (a) and the phosphor (b) as described above, and preferably further includes the phosphor (c) and / or the phosphor (d). These phosphors are used in the powder phase, although not particularly limited, the phosphors may have a size of several nanometers (nm) to several hundred micrometers (μm). The phosphor may preferably have a size of 1 to 30 μm. The phosphor is blended with an optically transparent resin in an appropriate amount and molded on a blue excitation light source, but is not particularly limited, but may be included in an amount of 0.1 to 30 wt%. That is, based on the total weight of the molding composition including the phosphor and the light transmitting resin, the phosphor may be included in an amount of 0.1 to 30% by weight. The phosphor may be included in an amount of 1.0 to 15% by weight, more preferably 2.0 to 10% by weight, based on the total weight of the molding composition.

In the present invention, two or more kinds of phosphors having different light emission wavelengths are used, including at least the phosphor (a) and the phosphor (b) as described above, wherein the phosphors preferably have an appropriate compounding ratio (weight ratio).

Specifically, according to the first embodiment of the present invention, when the phosphor includes a phosphor (a) having a light emission wavelength of 550 to 600 nm and an oxynitride-based phosphor represented by the formula (1), the phosphor (a ) And the phosphor (b) may be included in a weight ratio of 1.0 to 6.0: 1.0 to 2.5. That is, it is good to mix | blend in the weight ratio of fluorescent substance (a): fluorescent substance (b) = 1.0-6.0: 1.0-2.5. At this time, if the content (weight) of the phosphor (b) is too large for the phosphor (a) outside the above range, the brightness and efficiency (lm / W) of the white light may be lowered. And if the content (weight) of the phosphor (b) is too small, it may be difficult to implement a high correlation color temperature (CCT), in particular a high color rendering index (CRI) of 80 or more.

In addition, according to the second embodiment of the present invention, the phosphor may include a phosphor (a) having a light emission wavelength of 550 to 600 nm, an oxynitride-based phosphor represented by formula (1), and a phosphor having a light emission wavelength of 600 to 650 nm ( In the case of including c), the phosphor (a), the phosphor (b) and the phosphor (c) may be included in a weight ratio of 2.0 to 4.0: 1.5 to 2.0: 1.0 to 1.5. That is, it is good to mix | blend in the weight ratio of fluorescent substance (a): fluorescent substance (b): fluorescent substance (c) = 2.0-4.0: 1.5-2.0: 1.0-1.5. In this case, if the content (weight) of the phosphor (b) and the phosphor (c) is too large for the phosphor (a), the brightness and efficiency (lm / W) of the white light may be deteriorated. If the content of the phosphor (b) is too small outside the above range, the correlated color temperature (CCT) and the color rendering index (CRI) may be low, and if the content (weight) of the phosphor (c) is small, the effect of its inclusion, That is, it may be difficult to achieve a high color rendering index (CRI) of 90 or more.

In addition, according to the third embodiment of the present invention, the phosphor may include a phosphor having a light emission wavelength of 550 to 600 nm (a), an oxynitride-based phosphor represented by Formula 1, and a phosphor having a light emission wavelength of 500 to 550 nm ( In the case of d), the phosphor (a), the phosphor (b) and the phosphor (d) may be included in a weight ratio of 1.0 to 1.5: 1.0 to 2.0: 2.0 to 4.0. That is, it is good to mix | blend in the weight ratio of fluorescent substance (a): fluorescent substance (b): fluorescent substance (d) = 1.0-1.5: 1.0-2.0: 2.0-4.0. In this case, if the content (weight) of the phosphor (b) and the phosphor (d) is too large for the phosphor (a), the brightness and efficiency (lm / W) of the white light may be deteriorated. If the content of the phosphor (b) is too small outside the above range, the correlated color temperature (CCT) and the color rendering index (CRI) may be lowered, and if the content (weight) of the phosphor (d) is small, the effect of its inclusion, In other words, it may be difficult to improve the color rendering index (CRI).

Hereinafter, the Example of this invention is illustrated. The following examples are merely provided to aid the understanding of the present invention, whereby the technical scope of the present invention is not limited.

[Examples 1 to 13]

A blue gallium nitride diode (GaN LED) chip was attached to the center of the glass substrate with an adhesive, an electrode was connected, and a phosphor molding composition was molded on the blue GaN LED chip to prepare a white light emitting diode having a conventional structure. . In this case, the phosphor molding composition is used by appropriately mixing the silicone resin and the phosphor, the phosphor was composed of two or more mixed phosphors. Specifically, the phosphor is a yellow phosphor YAG: a composition having oxide YAG-base of Ce ^{3 +} (emission wavelength 550nm), SiAlON as a yellow phosphor: BaSi ₂ as a silicate-based (emission wavelength 580nm), cyan fluorescent substance having a composition of Eu ^{2 +} O ₂ N ₂ : Eu ^2: composition of Eu ^{2 +} having the oxynitride-based (emission wavelength 495nm), as the red phosphor _{CaAlSiN 3: SrSi 2 O 2 N} 2 silicate nitride-based (emission wavelength 620nm) having a composition of Eu ^{2 +,} as a green phosphor ^An oxynitride system having a composition of ⁺ (luminescence wavelength 535 nm) was used, but the type and compounding ratio (wt%) of the phosphors were varied according to the Examples (1 to 13) as shown in Table 1 below.

Comparative Example 1

In contrast to the above-described embodiment, to the yellow phosphor as a phosphor, as shown in Table 1: and are carried out except that, but only (YAG Ce ^{3 +,} emission wavelength 550nm), mixed with the yellow phosphor to 5.7% by weight A white light emitting diode was manufactured in the same manner as in Example.

Intensity was measured for the white light emitting diode specimens according to Examples 1 to 13 and Comparative Example 1 manufactured as described above, and the results are shown in FIGS. 1 to 3. In addition, the relative color temperature (CCT) and color rendering index (CRI) were measured for each specimen, and the results are shown together with the blending ratio in the following [Table 1].

<Luminous Characteristics According to Kinds and Mixing Ratio of Phosphor Phosphor>
Remarks silicon
(weight%) Type and compounding ratio of mixed phosphors (wt%) Luminous characteristics yellow
(550 nm) yellow
(580 nm) Turquoise
(495nm) Red
(620nm) green
(535 nm) CCT (K) CRI (Ra) Comparative Example 1 94.3 5.7 - - - - 5,852 73.4 Example 1 94.7 3.6 - 1.7 - - 6,410 80.1 Example 2 94.7 3.5 - 1.8 - - 6,193 80.4 Example 3 94.6 3.5 - 1.8 - - 6,235 80.1 Example 4 94.5 3.5 - 2.0 - - 7,437 81.2 Example 5 94.4 3.5 - 2.1 - - 6,788 80.8 Example 6 94.3 3.5 - 2.2 - - 6,471 80.6 Example 7 94.2 3.5 - 2.3 - - 6,230 80.5 Example 8 94.4 2.8 - 1.6 1.2 - 6,160 92.6 Example 9 94.3 2.8 - 1.7 1.2 - 7,221 94.0 Example 10 94.2 2.8 - 1.8 1.2 - 6,800 94.7 Example 11 94.6 - 1.2 1.4 - 2.8 6,458 84.1 Example 12 94.3 - 1.2 1.6 - 2.9 6,508 83.7 Example 13 94.1 - 1.2 1.7 - 3.0 6,558 83.8

First, as shown in the attached Figures 1 to 3, in the case of using two or more mixed phosphors including the turquoise phosphor according to the present invention (Examples 1 to 13), when using the yellow phosphor alone as in the prior (comparative It can be seen that the emission intensity (Intensity) is higher than Example 1). In addition, it can be seen that when further comprising a red phosphor (Examples 8 to 10), it shows a more improved emission intensity characteristics.

In addition, as shown in [Table 1], it can be seen that the correlation color temperature (CCT) and color rendering index (CRI) are improved when two or more kinds of mixed phosphors are used, including a cyan phosphor. Specifically, in the case of using the yellow phosphor alone as in the prior art (Comparative Example 1), the correlation color temperature (CCT) is less than 6,000K (5,852K), the color rendering index (CRI) is low as 73.4, but in accordance with the present invention is further added to the cyan phosphor In the case of including (Examples 1 to 13), the correlation color temperature (CCT) is 6,000K or more (as much as 7,000K or more), the color rendering index (CRI) can be seen that it is highly evaluated as 80 or more.

In addition, when the red phosphor further includes as in Examples 8 to 10, or when the green phosphor is further included as in Examples 11 to 13, it has been found that it has an improved correlation color temperature (CCT) and color rendering index (CRI). Can be. In particular, in the case of further including a red phosphor as in Examples 8 to 10, the correlation color temperature (CCT) is not only high, but also a high color rendering index (CRI) of 90 or more (94 or more in Examples 9 and 10). It can be seen that.

As can be seen from the above examples, when the phosphor is mixed and further composed of a cyan oxynitride-based phosphor in a phosphor (yellow or yellow) having a light emission wavelength of 550 to 600 nm, a correlated color temperature (CCT) and a color rendering index (CRI) It can be seen that is improved. In addition, when the phosphor further includes a red phosphor having a light emission wavelength of 600 to 650 nm and / or a green phosphor having a light emission wavelength of 500 to 550 nm, the correlation color temperature (CCT) and color rendering index (CRI) are further improved, and the emission intensity is also increased. Able to know. In particular, when the emission wavelength further includes a red phosphor of 600 ~ 650nm, it can be seen that the color rendering index (CRI) is 90 or more to implement a high color rendering white light.

Claims (6)

delete delete delete delete In a white light emitting diode comprising a blue excitation light source and a phosphor,
The phosphor is,
Phosphor (a) having a light emission wavelength of 550 to 600 nm;
An oxynitride-based phosphor represented by Formula 1 below (b); And
It includes a phosphor (c) having a light emission wavelength of 600 ~ 650nm,
The phosphor (a) having a light emission wavelength of 550 to 600 nm may be represented by Sr _3-x SiO ₅ : yEu ²⁺ (0 <x ≦ 1, 0 <y ≦ 1), SiAlON: Eu ²⁺ , and Chemical Formula 2 At least one selected from the composition,
The phosphor (c) having a light emission wavelength of 600 to 650 nm is at least one red phosphor selected from the compositions of (Ca, Sr) S: Eu ²⁺ , and CaAlSiN ₃ : Eu ²⁺ ,
The phosphor may include a phosphor (a) having a light emission wavelength of 550 to 600 nm, an oxynitride-based phosphor (b) represented by Formula 1, and a phosphor (c) having a light emission wavelength of 600 to 650 nm of 2.0 to 4.0: 1.5. ˜2.0: White light emitting diode comprising a weight ratio of 1.0 to 1.5.

[Formula 1]
BaSi ₂ O ₂ N ₂ : xEu ²⁺
(In Formula 1 above, x is 0 <x ≦ 1.0.)

(2)
Y ₃ A ₅ O ₁₂ : yCe ³⁺
(In Formula 2, A is one or more selected from Al, Ga, and Ge, and y is an integer or prime number greater than zero.)
In a white light emitting diode comprising a blue excitation light source and a phosphor,
The phosphor is,
Phosphor (a) having a light emission wavelength of 550 to 600 nm;
An oxynitride-based phosphor represented by Formula 1 below (b); And
It includes a phosphor (d) having a light emission wavelength of 500 ~ 550nm,
The phosphor (a) having a light emission wavelength of 550 to 600 nm may be represented by Sr _3-x SiO ₅ : yEu ²⁺ (0 <x ≦ 1, 0 <y ≦ 1), SiAlON: Eu ²⁺ , and Chemical Formula 2 At least one selected from the composition,
The phosphor (d) having a light emission wavelength of 500 to 550 nm includes Sr _1-x Ga ₂ S ₄ : yEu ²⁺ (0.001 ≦ x <1, 0.001 ≦ y ≦ 1), and SrSi ₂ O ₂ N ₂ : Eu ²⁺ At least one green phosphor selected from the composition of
The phosphor includes phosphors (a) having a light emission wavelength of 550 to 600 nm, oxynitride-based phosphors (b) represented by Formula 1, and phosphors (d) having a light emission wavelength of 500 to 550 nm of 1.0 to 1.5: 1.0. ˜2.0: White light emitting diode comprising a weight ratio of 2.0 to 4.0.

[Formula 1]
BaSi ₂ O ₂ N ₂ : xEu ²⁺
(In Formula 1 above, x is 0 <x ≦ 1.0.)

(2)
Y ₃ A ₅ O ₁₂ : yCe ³⁺
(In Formula 2, A is one or more selected from Al, Ga, and Ge, and y is an integer or prime number greater than zero.)

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