JP2015142056A - semiconductor light-emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor light-emitting device which can output mixed color light showing a high luminous efficiency while having color rendering properties.SOLUTION: A semiconductor light-emitting device including a light-emitting element radiating blue light, a first phosphor emitting fluorescent light having an emission peak in a range of 610-650 nm by being excited with blue light radiated from the light-emitting element, and a second phosphor emitting fluorescent light from green to yellowish green by being excited with blue light radiated from the light-emitting element, has an emission peak in a wavelength regio of 580-620 nm, and when the maximum emission intensity is 100%, the emission peak wavelength is λ, and the emission wavelength becoming 30% of the maximum emission intensity in a wavelength region larger than 620 nm is λ, the λ(p-p) obtained by subtracting the λfrom the λsatisfies following relationship. λ(p-p)=λ-λ<85nm.

Description

  The present invention relates to a semiconductor light emitting device in which a light emitting element and a phosphor are combined.

  Light emission that can emit light of various hues based on the principle of color mixing of light by combining a light source and a phosphor that can be excited by light from this light source and emit light of a hue different from the hue of the light source Equipment has been developed. For example, primary light from a short wavelength region corresponding to visible light is emitted from the light emitting element from ultraviolet light, and the phosphor is excited by the emitted light. As a result, at least a part of the primary light is wavelength-converted, and desired light such as red, blue, and green can be obtained. In addition, white color mixed light can be emitted by the color mixture of these lights.

  Using this principle, an LED lamp using a light emitting diode (hereinafter referred to as “LED”) as a light source is used as a signal light, a mobile phone, various types of lighting, an in-vehicle display, or various types of display devices. It is used in many fields. In particular, semiconductor light-emitting devices (hereinafter also simply referred to as “light-emitting devices”) formed by combining LEDs and phosphors are actively applied to backlights of liquid crystal displays, small strobes, etc. It is out. In recent years, attempts have been made to use it in lighting devices, and it is expected to be a light source that can replace fluorescent lamps with reduced environmental load by taking advantage of low power consumption, long life, and mercury-free.

  As a configuration of a light emitting device using an LED, a configuration in which a blue LED and a yellow phosphor are combined can be given (for example, see Japanese Patent No. 3503139 (Patent Document 1)). This light-emitting device can obtain white mixed light by mixing blue light from the LED and yellow light obtained by converting a part of the blue light emitted from the LED with a yellow phosphor. It is something that can be done. Therefore, the phosphor used in this light emitting device is required to have a characteristic of being efficiently excited by blue light having a wavelength of 420 nm to 470 nm emitted from the LED and emitting yellow light.

  In this specification, the relationship between color names and chromaticity coordinates, the relationship between the wavelength range of light and the color name of monochromatic light, and the like are in accordance with JIS Z8110. Specifically, 380 nm to 455 nm is blue purple, 455 nm to 485 nm is blue, 485 nm to 495 nm is blue green, 495 nm to 548 nm is green, 548 nm to 573 nm is yellow green, 573 nm to 584 nm is yellow, 584 nm to 610 nm is yellow red , 610 nm to 780 nm is red.

As yellow phosphors, cerium activated yttrium, aluminum and garnet phosphors are known. Further, a phosphor is known in which a part of Y of this yellow phosphor is substituted with Lu, Tb, Gd or the like, or a part of Al is substituted with Ga or the like. Such cerium-activated yttrium / aluminum / garnet phosphors can be expressed as (Y, Lu, Tb, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce, and can be widely used by adjusting the composition. It is possible to adjust the emission wavelength.

  When a general light-emitting device combining such a yellow phosphor and a blue LED is used for an illumination device, the luminous flux and the color rendering properties are important. For example, when a blue LED and a YAG phosphor are combined, since they are a mixed color of blue and yellow, the green component and the red component are insufficient and the color rendering property tends to be low. For this reason, it is necessary to improve color rendering in order to emit a warm bulb color having a higher color temperature. Therefore, in order to emit light in a warm light bulb color and improve color rendering, light emission is a combination of two or more of a blue LED, a phosphor emitting from green to yellow-green, and a phosphor emitting from orange to red. Equipment has been developed.

  Examples of such green, yellow-green, and red phosphors include silicate phosphors, phosphate phosphors, aluminate phosphors, borate phosphors, sulfide phosphors, and oxysulfide phosphors. Etc. are known. Further, in place of these phosphors, as phosphors with little decrease in luminance even at high energy excitation, for example, sialon phosphors, oxynitride phosphors, nitride phosphors, etc., inorganic containing nitrogen in the crystal structure Phosphors based on crystals have been proposed.

As a typical red phosphor used in a light emitting device, a nitride phosphor (hereinafter referred to as “CASN phosphor”) in which Eu ²⁺ is activated using CaAlSiN ₃ as a base crystal is known. (For example, refer to Japanese Patent No. 3837588 (Patent Document 2).) This phosphor has an emission peak wavelength in the vicinity of 650 nm. By combining this phosphor with a phosphor that emits light from green to yellow-green, a light emitting device with high color rendering properties can be obtained.

Furthermore, a phosphor whose composition formula is represented by (Sr, Ca) AlSiN ₃ : Eu in which a part of Ca in CaAlSiN ₃ : Eu is substituted with Sr (hereinafter referred to as “SCASN phosphor”) is known. The shorter the wavelength, the shorter the wavelength (see, for example, JP-A-2006-8721 (Patent Document 3)). The SCASN phosphor has a peak wavelength of 610 to 650 nm and emits light shorter than the CASN phosphor. By using such a red phosphor with a short wavelength, it is possible to make the light emitting device brighter due to the effect of visibility while adding a reddish component. For this reason, the SCASN phosphor can be said to be a very promising red phosphor.

Here, the SCASN phosphor is manufactured by a manufacturing process generally described below. First, raw material powders of calcium nitride (Ca ₃ N ₂ ), strontium nitride (Sr ₃ N ₂ ), silicon nitride (Si ₃ N ₄ ), aluminum nitride (AlN), and europium nitride (EuN) are used as Ca: Sr: Al: Si: Mix in a glove box in a nitrogen atmosphere such that Eu = 0.1984: 0.7936: 1: 1: 0.008. Then, after naturally dropping into a boron nitride crucible through a 500 μm sieve and filling it, it is set in an electric furnace of a graphite resistance heating system and is held in a 1 MPa nitrogen gas at a temperature of 1800 ° C. for 2 hours by a gas pressure sintering method. Bake. In this way, the SCASN phosphor is manufactured.

However, it has been found that this synthesis method can only obtain a phosphor having a low emission intensity of about 80% compared to the CASN phosphor. This is because the CASN phosphor is stable under such a synthesis condition, whereas the SCASN phosphor cannot exist stably and gradually decomposes into another compound (Sr ₂ SiN ₅ , AlN, etc.). This is because a pure SCASN phosphor was obtained. For this reason, a method for further improving the characteristics has been studied.

For this reason, there has been proposed a method in which calcium, strontium, silicon, aluminum, europium metal is alloyed without using calcium nitride, silicon nitride, aluminum nitride, etc., and the powder obtained by pulverizing the alloy is nitrided (for example, Japanese Patent Laid-Open No. 2006-2006). 307182 (Patent Document 4) or H. Watanabe, et al. "Synthetic Method and Luminescence Properties of Sr _x Ca _1-x AlSiN ₃ : Eu ²⁺ Mixed Nitride Phosphors" Journal of The Electrochemical Society, 155 (3) F31-F36 (2008) (see Non-Patent Document 1).

  Further, in order to obtain a light emitting device having high color rendering properties and high luminous efficiency, a combination of a green phosphor and a red phosphor has been studied (for example, JP 2008-244468 (Patent Document 5) or International Publication WO 2011). / 105157 (see Patent Document 6).

Japanese Patent No. 3503139 Japanese Patent No. 3837588 JP 2006-8721 A JP 2006-307182 A JP 2008-244468 A International Publication WO2011 / 105157

H. Watanabe, et al. "Synthetic Method and Luminescence Properties of SrxCa1-xAlSiN3: Eu2 + Mixed Nitride Phosphors" Journal of The Electrochemical Society, 155 (3) F31-F36 (2008)

  However, as described above, conventionally, the emission wavelength of the red phosphor and the excitation intensity of the specific wavelength and the emission wavelength of the green phosphor to be combined are specified, or the emission wavelength, the half width and the absorption of the specific wavelength of the red phosphor. The ratio and the half width of the green phosphor are specified, and in terms of practicality, the color rendering properties and the luminous efficiency are still insufficient.

  The present invention has been made in view of such problems. That is, an object of the present invention is to provide a semiconductor light emitting device capable of outputting white mixed color light that exhibits high luminous efficiency while having color rendering properties.

  The present invention includes a light emitting element, a first phosphor that emits fluorescence having a light emission peak in a range of 610 to 650 nm when excited by light from the light emitting element, and 500 to 600 excited by light from the light emitting element. A second phosphor that emits fluorescence having an emission peak in a range of 560 nm, and emits semiconductor light that emits mixed light of light from the light emitting element and fluorescence from the first and second phosphors The emission spectrum of the mixed color light has an emission peak in a wavelength region of 580 nm or more and 620 nm or less, and the emission intensity of the mixed color light is 30 of the emission intensity at the peak in a wavelength region of more than 620 nm. %, And the difference between the emission peak wavelength at the peak is smaller than 85 nm.

  The semiconductor light-emitting device of the present invention can realize both high color rendering properties and light flux while reducing long wave components with low visibility, by using the SCASN phosphor having the emission spectrum as a unique profile.

FIG. 1 is a cross-sectional view showing a light emitting device according to this embodiment. FIG. 2 is a graph showing emission spectra of the phosphors of Examples 1 to 3 and Comparative Example 1. FIG. 3 is a graph showing emission spectra of the phosphors of Examples 4 to 6. FIG. 4 is a graph showing the reflection spectra of Examples 1 to 3 and Comparative Example 1. FIG. 5 is a graph showing the reflection spectra of the phosphors of Examples 4 to 6. FIG. 6 is a graph showing emission spectra of the phosphors of Reference Examples 1 and 2. FIG. 7 is a graph showing normalized emission spectra in the light emitting devices of Example 11 and Comparative Example 11. FIG. 8 is a graph showing normalized emission spectra in the light emitting devices of Example 12 and Comparative Example 12. FIG. 9 is a graph showing normalized emission spectra in the light emitting devices of Example 13 and Comparative Example 13. FIG. 10 is a graph showing normalized emission spectra in the light emitting devices of Example 14 and Comparative Example 14. FIG. 11 is a graph showing normalized emission spectra in the light emitting devices of Example 15 and Comparative Example 15. 12 is a graph showing normalized emission spectra in the light emitting devices of Example 16 and Comparative Example 16. FIG. FIG. 13 is a graph showing normalized emission spectra in the light emitting devices of Example 17 and Comparative Example 17. FIG. 14 is a graph showing normalized emission spectra in the light-emitting devices of Example 18 and Comparative Example 18. FIG. 15 is a graph showing normalized emission spectra in the light emitting devices of Example 19 and Comparative Example 19. FIG. 16 is a graph showing normalized emission spectra in the light emitting devices of Example 20 and Reference Example 20. FIG. 17 is a graph showing a normalized emission spectrum in the light emitting devices of Examples 21 to 22. FIG. 18 is a graph showing normalized emission spectra in the light emitting devices of Examples 23 to 25.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiment described below exemplifies a semiconductor light emitting device for embodying the technical idea of the present invention, and the present invention does not specify the semiconductor light emitting device as follows. In addition, the member shown by a claim is not limited to the member of embodiment. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in the embodiments are not intended to limit the scope of the present invention unless otherwise specified, and are merely explanations. It is just an example.

  As a result of further earnest research, the present inventors have optimized the emission spectrum shape of the light emitting device, particularly the intensity of the light emitting component in the long wavelength region and the intensity of the light emitting component at 550 nm. In addition, the present invention has been completed by controlling the emission spectrum shape of the SCASN phosphor, which is a red phosphor used in the light emitting device, in particular, the emission peak wavelength, half-value width, or reflectance.

  That is, the present invention includes a light emitting element, a first phosphor that emits fluorescence having a light emission peak in a range of 610 to 650 nm when excited by light from the light emitting element, and 500 excited by light from the light emitting element. And a second phosphor that emits fluorescence having an emission peak in the range of ˜560 nm, and emits mixed color light of light from the light emitting element and fluorescence from the first and second phosphors. It is. The emission spectrum of the mixed color light has an emission peak in a wavelength region of 580 nm or more and 620 nm or less, and when the emission intensity is 100%, the emission intensity is 580 nm in the emission peak wavelength and a wavelength region greater than 620 nm. The difference from the emission wavelength which is 30% of the emission intensity at the emission peak in the wavelength region of 620 nm or less is smaller than 85 nm.

More specifically, the present invention relates to the emission spectrum of the mixed color light of the light from the light emitting element and the fluorescence from the first and second phosphors, and the emission peak existing in the wavelength region of 580 nm to 620 nm. Let the emission intensity be 100%, and the emission peak wavelength at that time be λ _p . Furthermore, the emission wavelength emission intensity becomes 30% of the emission intensity as a lambda _p30% in 620nm greater than the wavelength range, a difference obtained by subtracting the lambda _p from lambda _p30%, the herein lambda (p _30% - p). At this time, the present invention satisfies the following relational expression.

λ (p _30% -p) = λ _p30% -λ _p <85nm

Note that the short wavelength region from near ultraviolet to visible light in this specification refers to a region near 240 nm to 500 nm. As the excitation light source, one having an emission peak wavelength at 240 nm to 480 nm can be used. Among these, it is preferable to use an excitation light source having an emission peak wavelength at 360 nm to 470 nm. In particular, it is preferable to use an excitation light source having a wavelength of 380 nm to 420 nm or 450 nm to 470 nm used in a semiconductor light emitting device. By using a semiconductor light emitting element as an excitation light source, it is possible to obtain a stable light emitting device that is highly efficient, has high output linearity with respect to input, and is resistant to mechanical shock.
(Phosphor)

The phosphor according to the embodiment of the present invention is activated by europium and emits red light by absorbing near ultraviolet light or blue light. This phosphor is represented by the general formula (Sr, Ca) AlSiN ₃ : Eu. In addition, the phosphor may contain various additive elements as flux and, if necessary, boron. Thereby, it becomes possible to promote solid-phase reaction and form particles of uniform size.

  In addition, the phosphor according to the embodiment of the present invention absorbs light in the short wavelength side region from ultraviolet to visible light, and has the emission peak wavelength of the phosphor on the longer wavelength side than the emission peak wavelength of excitation light. . The light in the short wavelength region of visible light is mainly in the blue light region. Specifically, it is excited by light from an excitation light source having an emission peak wavelength at 250 nm to 500 nm, and emits fluorescence having a peak wavelength in a wavelength range of 600 to 650 nm. This is because a phosphor with high luminous efficiency can be provided by using an excitation light source in such a range. In particular, an excitation light source having a main emission peak wavelength at 250 nm to 420 nm or 420 nm to 500 nm is preferably used, and an excitation light source having an emission peak wavelength at 420 to 480 nm is more preferably used.

  Moreover, it is preferable that at least a part of the nitride phosphor has a crystal. For example, since the structure of a glass body (amorphous) is loose, unless the reaction conditions in the production process can be controlled so as to be strictly uniform, the component ratio in the phosphor is not constant, and chromaticity unevenness occurs. Arise. On the other hand, the phosphor according to the present embodiment is easy to manufacture and process because it has crystallinity instead of a glass body. Further, since this phosphor can be uniformly dissolved in an organic medium, it is easy to adjust the light emitting plastic and the polymer thin film material. Specifically, in the phosphor according to the present embodiment, at least 50% by weight or more, more preferably 80% by weight or more has crystals. This indicates the proportion of the crystalline phase having luminescent properties, and if it has a crystalline phase of 50% by weight or more, light emission that can withstand practical use can be obtained. Therefore, the more crystal phases, the better. As a result, the emission luminance can be increased and processing can be facilitated.

In the phosphor according to the embodiment of the present invention, europium Eu, which is a rare earth, becomes the emission center. However, it is not limited to only europium, and a part of which is partially activated with other rare earth metals or alkaline earth metals and co-activated with Eu can be used. Eu ^2+, which is a divalent rare earth ion, exists stably if an appropriate matrix is selected, and has the effect of emitting light.
(Phosphor raw material)

  Next, a method for manufacturing a nitride phosphor will be described. The phosphor according to the present invention is manufactured by mixing various phosphor raw materials in a wet type and a dry type. As the phosphor material, Sr, Ca, Si, Al, Eu, and if necessary, an additive element is used alone, or each compound is used. Each raw material will be described below.

  Sr in the phosphor composition may be substituted alone or a part of Sr may be substituted with Ca, Mg, Ba or the like. Similarly to Sr, Ca of the phosphor composition can be substituted alone or a part of Ca with Sr, Mg, Ba, or the like. Thereby, the peak of the emission wavelength of the nitride phosphor can be adjusted.

  As Ca of the phosphor composition, it is preferable to use a simple substance, but compounds such as an imide compound and an amide compound can also be used. The raw material Ca may contain Li, Na, K, B, Al, or the like. The raw material is preferably purified. Thereby, since a purification process is not required, the manufacturing process of the phosphor can be simplified, and an inexpensive nitride phosphor can be provided. The raw material Ca is pulverized in a glove box in an argon atmosphere. As a guide for Ca grinding, the average particle size is preferably in the range of about 0.1 μm or more and 15 μm or less from the viewpoint of reactivity with other raw materials, particle size control during and after firing, etc., It is not limited to this range. The purity of Ca is preferably 2N or higher, but is not limited thereto.

  Si having a phosphor composition is also preferably used alone, but a part of it can be substituted with group IV elements such as Ge, Sn, Ti, Zr, and Hf. However, using only Si, the nitride phosphor is inexpensive and has good crystallinity.

Al having a phosphor composition is also preferably used alone, but a part of it can be substituted with Group III elements Ga, In, V, Cr, and Co. However, it is possible to obtain a nitride phosphor that is inexpensive and has good crystallinity by using only Al. However, Al nitride or Al oxide may be used. It is better to use purified materials, but commercially available products may be used. Specifically, aluminum nitride AlN can be used as the Al nitride, and aluminum oxide Al ₂ O ₃ can be used as the Al oxide.

Eu of the activator is preferably used alone, but a part of Eu is Sc, Y, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu. May be substituted. By substituting a part of Eu with another element, the other element acts as a co-activation. By co-activation, the color tone can be changed, and the light emission characteristics can be adjusted. When using a mixture in which Eu is essential, the blending ratio can be changed as desired. Europium mainly has bivalent and trivalent energy levels, but nitride phosphors use Eu ²⁺ as an activator for the base material, eg, Ca.

Further, a Eu compound may be used as a raw material. In this case, it is better to use a purified raw material, but a commercially available product may be used. Specifically, europium oxide Eu ₂ O ₃ , metal europium, europium nitride, and the like can be used as Eu compounds. The raw material Eu may be an imide compound or an amide compound. Europium oxide preferably has a high purity, and commercially available products can also be used. The phosphor according to the embodiment of the present invention uses divalent Eu as the center of light emission, but divalent Eu is easily oxidized and is generally commercially available with a composition of trivalent Eu ₂ O ₃ .

  Furthermore, the element to be added as necessary is usually added as an oxide or an oxide hydroxide, but is not limited to this, and may be a metal, nitride, imide, amide, or other inorganic salt, Moreover, the state previously contained in the other raw material may be sufficient.

In addition, oxygen may be contained in the composition of the nitride-based phosphor according to the embodiment of the present invention. It is considered that oxygen is introduced from various oxides as raw materials, the raw materials are oxidized during firing, or adheres to and mixes with the phosphor after generation. In general, by controlling the molar ratio of oxygen in the composition, it is possible to change the crystal structure of the phosphor and shift the emission peak wavelength of the phosphor. However, from the viewpoint of luminous efficiency, it is preferable that the concentration of oxygen contained in the phosphor is small, and it is preferable that the oxygen concentration be 5 w% or less with respect to the mass of the product phase.
(flux)

  For example, a flux such as boron can be added to the phosphor according to the embodiment of the present invention. In general, many nitride phosphors have a high melting point, and it is difficult for a liquid phase to occur when a solid phase reaction is performed, and the reaction does not proceed smoothly. However, in the case of containing boron, the liquid phase formation temperature is lowered and the liquid phase is likely to be generated, so that the reaction is promoted, and further, the individual phase reaction proceeds more uniformly, and the light emission characteristics are excellent. It is considered that a phosphor can be obtained. The molar concentration of boron added to the nitride phosphor is 0.5 mol or less, preferably 0.3 mol or less. Furthermore, it is set to 0.001 mol or more. More preferably, the molar concentration of boron is 0.001 or more and 0.2 or less. This is because if the concentration is within this range, the above-described effects can be obtained, and the sintering does not become intense, and the light emission characteristics are not deteriorated in the crushing step. Since a boron compound is a substance having a high thermal conductivity, it is presumed that, when added to the raw material, the temperature distribution of the raw material during firing becomes uniform, promotes the individual phase reaction, and improves the light emission characteristics. As a method of addition, a method of adding and mixing together at the time of mixing raw materials can be adopted.

Boron, boride, boron nitride, boron oxide, borate, etc. can be used as the boron material of the phosphor. Specific examples of boron added to the phosphor material include B, BN, H ₃ BO ₃ , B ₂ O ₃ , BCl ₃ , SiB ₆ , and CaB ₆ . A predetermined amount of these boron compounds is weighed and added to the raw material.
(Phosphor production method)

Next, as an example of the phosphor according to the present invention, the general formula _{Sr t Ca v Eu w Al x} Si y N z (0.8 <t <1.0,0 <v <0.19,0.005 <W ≦ 0.03, t + v + w <1, 0.90 ≦ x ≦ 1.1, 0.90 ≦ y ≦ 1.1, 2.5 ≦ z ≦ 3.5) Among these, a method for producing a nitride phosphor whose composition is represented by Sr _0.85 Ca _0.135 Eu _0.015 AlSiN ₃ will be described. However, the method for producing a nitride phosphor and its composition are not limited to this production method and composition.

  First, the raw material Ca is pulverized. Next, the raw material Ca is nitrided in a nitrogen atmosphere. That is, a nitride of Ca can be obtained by nitriding raw material Ca at 600 ° C. to 900 ° C. for about 5 hours in a nitrogen atmosphere. The Ca nitride is preferably of high purity. This reaction formula is shown in Chemical Formula 1.

  Further, the Ca nitride is pulverized in a glove box in an argon atmosphere or a nitrogen atmosphere.

The raw material Sr is also nitrided in a nitrogen atmosphere in the same manner as Ca. Nitriding is performed at 600 ° C. to 900 ° C., and this reaction formula is shown in Chemical Formula 2.

On the other hand, the raw material Si is pulverized. The raw material Si is preferably a simple substance, but a nitride compound, an imide compound, an amide compound, or the like can also be used. For example, Si ₃ N ₄ , Si (NH ₂ ) ₂ , Mg ₂ Si, etc. The purity of the raw material Si is preferably 3N or higher, but may contain different elements such as Li, Na, K, B, Al and Cu. Si is also pulverized in a glove box in an argon atmosphere or a nitrogen atmosphere in the same manner as the raw material Ca. The average particle size of the Si compound is preferably in the range of about 0.1 μm to 15 μm from the viewpoint of reactivity with other raw materials, particle size control during and after baking, but is not limited thereto.

  Next, the raw material Si is nitrided in a nitrogen atmosphere. Specifically, silicon nitride is obtained by nitriding silicon Si at 800 ° C. to 2000 ° C. for about 5 hours in a nitrogen atmosphere. The silicon nitride used in the present invention is preferably highly pure. This reaction formula is shown in the following [Chemical Formula 3].

  Similarly, Si nitride is pulverized to 0.1 μm to 10 μm in a glove box in a nitrogen atmosphere.

On the other hand, AlN is synthesized by Al nitridation or the like. The AlN which is the nitride of Al and the Eu compound Eu ₂ O ₃ are pulverized. The average particle size after pulverization is preferably about 0.1 μm to 15 μm, more preferably about 0.1 μm to 10 μm, the reactivity with other raw materials, the particle size during and after firing. Although it is preferable from the viewpoint of control and the like, it is not limited to this. However, commercially available AlN powder can also be used. Thereby, a process can be simplified.

  After the above pulverization, for example, Sr nitride such that Sr: Ca: Eu: Al: Si = 0.85: 0.135: 0.015: 1.0: 1.0 is obtained. Ca nitride, Si nitride, Al nitride, Eu oxide, and, if necessary, a compound of an additive element are weighed and mixed. The composition ratio of the target phosphor is not limited to the above composition ratio. This mixing can also be performed dry.

The above mixture is fired in a nitrogen atmosphere. For the firing, a gas pressure electric furnace can be used. Firing can be performed in the range of 1200 ° C. to 2200 ° C., but a firing temperature of 1500 ° C. to 2100 ° C. is preferable. Firing can also be performed using two-stage firing (multi-stage firing) in which first-stage firing is performed at 800 ° C. to 1400 ° C. and second-stage firing is performed by gradually heating at 1500 ° C. to 2100 ° C. The phosphor material is preferably fired using a carbon material such as graphite, a crucible made of boron nitride (BN), or a boat. In addition to the above, a crucible such as alumina (Al ₂ O ₃ ) or Mo material can be used, but BN is preferred.

  The reducing atmosphere can be an atmosphere containing at least one of nitrogen, hydrogen, argon, carbon dioxide, carbon monoxide, and ammonia. However, firing can be performed in a reducing atmosphere other than these.

A phosphor represented by Sr _0.85 Ca _0.135 Eu _0.015 AlSiN ₃ can be obtained by firing. An example of the reaction formula of the nitride phosphor by this firing is shown in Chemical Formula 4.

  However, this composition is a representative composition estimated from the blending ratio. Moreover, the composition of the target phosphor can be changed by changing the blending ratio of each raw material.

  Other synthesis methods are also possible. Specifically, the metals of each element are weighed so as to have a predetermined composition ratio and then melted to synthesize an alloy. After the alloy is pulverized, the alloy can be nitrided in a gas pressure sintering furnace or HIP furnace in an N 2 gas atmosphere to synthesize a nitride having a target composition.

  The target nitride phosphor can be obtained by the above manufacturing method. Eu is a rare earth element, and includes a rare earth element such as La, Ce, Gd, Tb, Dy, Ho, Er, Tm, and Lu in place of Eu in addition to various rare earth elements. It is also possible to use a nitride phosphor. As described above, a good nitride phosphor can be obtained.

The emission characteristics data related to the nitride phosphor described above will be described later, but the phosphor according to the present embodiment can control the emission peak wavelength and the half-value width, particularly reduce the long wavelength component and reduce the half-value width. Was confirmed. Therefore, in the light emitting device using the nitride phosphor, the use of the nitride phosphor has a feature that the luminous flux can be increased without impairing the color rendering.
(Particle size)

  The particle size of the nitride phosphor is preferably in the range of 5 μm to 20 μm. A phosphor having a particle size range of 5 μm to 20 μm has high light absorption and conversion efficiency. As described above, the luminous efficiency of the light-emitting device is improved by including a phosphor having a large particle diameter having optically superior characteristics in the light-emitting device described later. Moreover, it is preferable that the phosphor having this average particle diameter is contained frequently. As described above, by using a phosphor having a small variation in particle size and particle size distribution, color unevenness is further suppressed, and a light emitting device having a good color tone can be obtained.

Here, the particle size is F.I. S. S. S. No. (Fisher Sub Sieve Sizer's No.) refers to the average particle size obtained by the air permeation method. Specifically, in an environment with an air temperature of 25 ° C. and a humidity of 70%, a sample of 1 cm ₃ is weighed and packed in a special tubular container, then a constant pressure of dry air is flowed, and the specific surface area is read from the differential pressure. It is a value converted into an average particle diameter. The average particle diameter of the phosphor used in the present embodiment is preferably in the range of 2 μm to 15 μm. Moreover, it is preferable that the phosphor having this average particle diameter value is contained frequently. Further, the particle size distribution is preferably distributed in a narrow range. As described above, by using a phosphor having a small variation in particle size and particle size distribution, color unevenness is further suppressed, and a light emitting device having a good color tone can be obtained.
(Light emitting device)

  Next, a light emitting device using the above nitride phosphor will be described. Examples of the light emitting device include a lighting device such as a fluorescent lamp, and a display device such as a display and a radar. A semiconductor light emitting device is used as the excitation light source of the nitride phosphor. Here, the light emitting element is used to include not only an element that emits visible light but also an element that emits near ultraviolet light, far ultraviolet light, or the like. In addition to the semiconductor light emitting element, an excitation light source having an emission peak wavelength in the short wavelength region from ultraviolet to visible light, such as a mercury lamp used in an existing fluorescent lamp, can be appropriately used as the excitation light source.

  Here, as an embodiment of the light-emitting device, a surface-mount type semiconductor light-emitting device including a light-emitting element that emits light in a short wavelength region from near ultraviolet to visible light is used as an excitation light source. The light emitting element is small in size, has high power efficiency, and emits bright colors. In addition, since the light emitting element is a semiconductor element, there is no fear of a broken ball. In addition, it has excellent initial drivability and is strong against vibration and repeated on / off lighting. Therefore, a light-emitting device that combines a light-emitting element and a nitride phosphor is preferable.

There are various types of light emitting devices equipped with such a light emitting element, such as a so-called bullet type and surface mount type. In this embodiment, a surface-mounted light-emitting device will be described with reference to FIG. This figure is a schematic diagram of the light emitting device 100 according to the present embodiment. The light emitting device 100 according to the present embodiment includes a package 40 having a recess, the light emitting element 10, and a sealing member 50 that covers the light emitting element 10. The light emitting element 10 is disposed in a recess formed in the package 40, and is electrically connected to a pair of positive and negative lead electrodes 20, 30 disposed in the package 40 by a conductive wire 60. The sealing member 50 is filled in the recess and is formed of a resin containing the phosphor 70. Further, a part of the pair of positive and negative lead electrodes 20, 30 is exposed on the outer surface of the package 40. The light emitting device 100 emits light upon receiving power supply from the outside via the lead electrodes 20 and 30. Below, the member which comprises the light-emitting device which concerns on this Embodiment is demonstrated.
(Light emitting element 10)

  The light emitting element 10 has a semiconductor layer formed by sequentially laminating an n-type layer, an active layer, and a p-type layer made of a nitride semiconductor on a sapphire substrate. An n-side pad electrode is formed on the n-type semiconductor exposed separately from each other, while a p-side pad electrode is formed on the p-side ohmic electrode.

  Specifically, as the light emitting element 10, a semiconductor light emitting element in which a semiconductor layer is epitaxially grown on a growth substrate can be suitably used. Examples of the growth substrate include sapphire, but are not limited thereto. For example, a known material such as spinel, SiC, GaN, GaAs or the like can be used. In addition, by using a conductive substrate such as SiC, GaN, or GaAs instead of an insulating substrate such as sapphire, the p-side electrode and the n-side electrode can be arranged on the upper and lower surfaces of the light-emitting element. .

For the light emitting element, various materials such as BN, SiC, ZnSe, GaN, InGaN, InAlGaN, AlGaN, BAlGaN, and BInAlGaN can be used. Similarly, these elements can contain Si, Zn, or the like as an impurity element to serve as a light emission center. As a material of the light emitting layer, a nitride semiconductor (for example, a nitride semiconductor containing Al or Ga, a nitride semiconductor containing In or Ga, In _X Al _Y Ga _1-XY N (0 ≦ X ≦ 1, 0 ≦ Y ≦ 1, X + Y ≦ 1), etc. The semiconductor structure is preferably a homostructure having a MIS junction, PIN junction, pn junction, etc., a heterostructure, or a double heterostructure. Various emission wavelengths can be selected depending on the material of the semiconductor layer and its mixed crystal ratio, and by making the semiconductor active layer into a single quantum well structure or a multiple quantum well structure formed in a thin film that produces quantum effects, In addition, the light emitting element can emit light from the ultraviolet region to the visible light region, particularly a light emitting element having an emission peak wavelength in the vicinity of 350 nm to 550 nm. It is preferable to have a light emitting layer that can emit light having an emission wavelength that can efficiently excite a fluorescent substance.Here, a nitride semiconductor light emitting element is described as an example of the light emitting element, but the present invention is not limited thereto. It is not a thing.

  The light emitting element is preferably a nitride semiconductor element containing In or Ga. This is because the nitride phosphor of the present embodiment emits strong light in the vicinity of 270 nm to 500 nm, and thus a light emitting element in this wavelength region is required. This light emitting element emits light having an emission peak wavelength in the short wavelength region from near ultraviolet to visible light, and at least one or more phosphors are excited by the light from the light emitting element, and exhibit a predetermined emission color. In addition, since the light emitting element can narrow the emission spectrum width, the nitride phosphor can be excited efficiently and the light emitting device does not substantially affect the color tone change. An emission spectrum can also be emitted.

By using the light emitted from the light emitting element as an excitation light source of the nitride phosphor described above, it is possible to realize an efficient light emitting device that consumes less power than a conventional mercury lamp.
(Phosphor 70)

  The phosphor 70 according to the present embodiment is blended so as to be partially unevenly distributed in the sealing member 50. At this time, the sealing member functions not only as a member for protecting the light emitting element and the phosphor from the external environment but also as a wavelength conversion member. By placing the light emitting element 10 close to the light emitting device 10 as described above, the wavelength of light from the light emitting element 10 can be efficiently converted, and a light emitting device having excellent light emission efficiency can be obtained. In addition, arrangement | positioning with the member containing a fluorescent substance and a light emitting element is not limited to the form which arranges them closely, and considers the influence of the heat | fever to a fluorescent substance and contains a light emitting element and fluorescent substance. It can also arrange | position with the space | interval with a wavelength conversion member. Further, by mixing the phosphor 70 in the sealing member 50 at a substantially uniform ratio, it is possible to obtain light without color unevenness.

  Moreover, the phosphor 70 may use two or more kinds of phosphors. For example, in the light emitting device 100 according to the present embodiment, the color rendering is achieved by using the light emitting element 10 emitting blue light, the phosphor according to the embodiment excited by the light emitting element 10 and the phosphor emitting red light together. White color mixed light excellent in properties can be obtained.

  In addition, a green phosphor or a blue phosphor can be combined with the nitride phosphor according to the present embodiment. Color reproducibility and color rendering can be further improved by further adding a phosphor that emits green light or a phosphor that emits blue light that has a slightly different emission peak wavelength from the nitride phosphor according to the present embodiment. it can. In addition, by adding a phosphor that absorbs ultraviolet light and emits blue light, it is possible to improve color reproducibility and color rendering by combining light emitting elements that emit ultraviolet light instead of light emitting elements that emit blue light. it can.

Examples of the phosphor emitting green light include (Y, Gd, Tb, Lu) ₃ (Al, Ga) ₅ O ₁₂ : Ce, (Ba, Sr, Ca) ₂ SiO ₄ : Eu, Si _6-z Al. _{z O z N 8-z:} Eu, (Ca, Sr) 8 MgSi 4 O 16 Cl 2: Eu, Ca 3 Sc 2 Si 3 O 12: Ce, CaSc 2 O 4: Ce, SrGaS 4: Eu or ( Silicate phosphor such as Ca, Sr, Ba) ₂ SiO ₄ : Eu, Ca ₃ Sc ₂ Si ₃ O ₁₂ : Ce, Chlorosilicate phosphor such as Ca ₈ MgSi ₄ O ₁₆ Cl _{2 -δ} : Eu, Mn (Ca, Sr, Ba) ₃ Si ₆ O ₉ N ₄ : Eu, (Ca, Sr, Ba) ₃ Si ₆ O ₁₂ N ₂ : Eu, (Ca, Sr, Ba) Si ₂ O ₂ N ₂ : Eu , CaSc ₂ O ₄ : Ce, Si _6-z Al _z O _z N _8-z : Oxynitride phosphors such as β-sialon of Eu, (Y, L u) ₃ (Al, Ga) ₅ O ₁₂ : Ce-activated aluminate phosphors such as Ce and Eu-activated sulfide phosphors such as SrGa ₂ S ₄ : Eu can be used.
(Sealing member 50)

The sealing member 50 is formed by being filled with a translucent resin or glass so as to cover the light emitting element 10 placed in the recess of the light emitting device 100. In view of ease of manufacture, the material of the sealing member is preferably a translucent resin. As the translucent resin, a silicone resin composition is preferably used, but an insulating resin composition such as an epoxy resin composition or an acrylic resin composition can also be used. Moreover, although the phosphor 70 is contained in the sealing member 50, other materials can be added as appropriate. For example, by including a light diffusing material, the directivity from the light emitting element can be relaxed and the viewing angle can be increased.
(Example of phosphor)

Hereinafter, as an example of the present invention, a result of manufacturing a nitride phosphor and a light emitting device using the same and measuring the light emission characteristics will be described.
(Comparative example 1, Examples 1-6)

First, the phosphors of Examples 1 to 6 and Comparative Example 1 represented by the general formula (Sr, Ca) AlSiN ₃ : Eu are weighed so that the constituent elements thereof are charged composition ratios shown in Table 2 below. It was manufactured by the above-described method for manufacturing a phosphor from each material.

Table 1 shows the emission characteristics and reflectance of the phosphors of Comparative Example 1 and Examples 1 to 6 obtained by the above method. In Table 1, ENG represents energy, and λ _p represents peak wavelength. Table 2 shows the target composition ratio of each element of the phosphor. 2 shows the normalized emission spectra of the phosphors of Examples 1 to 3 and Comparative Example 1, FIG. 3 shows the normalized emission spectra of the phosphors of Examples 4 to 6, and FIG. 3 shows the reflection spectrum of the phosphor of Comparative Example 1, and FIG. 5 shows the reflection spectra of the phosphors of Examples 4-6. As shown in Table 1, FIG. 2, and FIG. 3, the full width at half maximum of Comparative Example 1 is 85 nm or more, and the reflectance at 550 nm is as high as 30% or more. The emission wavelengths of these phosphors are 620 to 635 nm, and the luminance of the phosphors of the examples is higher and better than that of Comparative Example 1.

FIG. 6 shows emission spectra of Y ₃ (Ga, Al) ₅ O ₁₂ : Ce and Lu ₃ Al ₅ O ₁₂ : Ce, which are green-emitting phosphors combined with the SCASN phosphor. In this figure, Reference Example 1 is Y ₃ (Ga, Al) ₅ O ₁₂ : Ce, and Reference Example 2 is Lu ₃ Al ₅ O ₁₂ : Ce. It can be seen that the green light emission has a wide half-value width.

Further, Table 3 shows the results of evaluating the characteristics of Example 11 and Comparative Example 11 in which the phosphors of Example 1 and Comparative Example 1 and the phosphor of Reference Example 1 are combined to form a light emitting device. FIG. 7 shows normalized emission spectra of the light emitting devices of Example 11 and Comparative Example 11. Here, as an LED, an LED chip having a size of 500 μm × 290 μm and an emission peak wavelength of 455 nm was used, and a surface-mounted light-emitting device was prototyped in combination with a phosphor. x and y are chromaticities of the light emitting device, Ra is the average color rendering index, λ _p is the maximum emission peak wavelength of the light emitting device, λ _p30% is a wavelength that is _30% of the maximum peak intensity in a wavelength region greater than 620 nm, λ _p30% 1-? _p is the wavelength minus the emission peak wavelength from the wavelength at which 30% of the maximum peak intensity, the intensity ratio of I _{550 nm} is 550 nm, represents respectively.

As shown in Table 3, the color temperature of the light emitting device is about 2700 K, and the color rendering property Ra> 80 is high. In particular, the Ra of Comparative Example 11 and Example 11 is substantially the same, but the luminous flux of Example 11 when the luminous flux of Comparative Example 11 is 100% is 106.4%, which is even higher. In addition, in Example 11, λ _p is 608.2 nm, λ _p30% −λ _p is 85 nm or less, and it can be seen that the wavelength at which the intensity is 30% is close to the peak wavelength. That is, the long wavelength component with low visibility is decreased, and the luminous flux of the embodiment is increased by this influence. Here, the position where the emission peak intensity is 30% is a position away from the emission peak wavelength to some extent. By setting the wavelength here as the evaluation position, it is easy to evaluate that the half width of the emission spectrum is narrow. .

Further, I _{550 nm} is as low as 59% or less, and not only the long wavelength component but also the spectral shape of the light emitting device near 550 nm is changed as shown in FIG. Although the spectral shape of the LED changes due to the reflectance of the phosphor at 550 nm and the half width, even if the long wavelength decreases due to this spectral change, the luminous flux can be increased without lowering Ra.

（比較例１２、実施例１２）

(Comparative Example 12, Example 12)

  Similarly, Comparative Example 12 and Example 12 produced as light emitting devices are light emitting devices having a color temperature of about 2800K. The configuration of the light emitting device is the same as that of Comparative Example 11 and Example 11 except for the blending ratio of the phosphors. Table 4 shows the characteristics of the light emitting devices of Example 12 and Comparative Example 12, and FIG. 8 shows the normalized emission spectra of the light emitting devices of Example 12 and Comparative Example 12, respectively.

As shown in these figures, Example 12 has about 5% higher luminous flux than Comparative Example 12. At this time, λ _{p in} Example 12 is 608 nm, and λ _p30% −λ _p is 85 nm or less, and there are few long wave components. In addition, I _{550 nm} is 59% or less at about 2800 K. Compared with Comparative Example 12, Ra is equal to or higher, and the luminous flux is higher in the example. Thus, high color rendering properties and high luminous flux were obtained.

（比較例１３、１４、実施例１３、１４）

(Comparative Examples 13 and 14, Examples 13 and 14)

  Similarly, Comparative Example 13 and Example 13 prepared as light emitting devices are light emitting devices in which the color temperature is about 2900K, and Comparative Example 14 and Example 14 are about 3000K. The configuration of the light emitting device is the same as that of Comparative Example 11 and Example 11 except for the blending ratio of the phosphors. Table 5 shows the characteristics of the light emitting devices of Example 13 and Comparative Example 13, Table 6 shows the properties of the light emitting devices of Example 14 and Comparative Example 14, and FIG. 9 shows the normalized light emitting devices of Example 13 and Comparative Example 13. FIG. 10 shows emission spectra of the light emitting devices of Example 14 and Comparative Example 14, respectively.

As shown in these figures, Examples 13 and 14 have about 4% higher luminous flux than Comparative Examples 13 and 14. At this time, λ _{p in} Examples 13 and 14 is 608.0 nm and 605.9 nm, and λ _p30% −λ _p is 85 nm or less, and there are few long wave components. In addition, I _{550 nm} is 64% or less, and Ra is equal to or higher than that of the comparative example, whereas the luminous flux is higher in the example. Each has high color rendering properties and high luminous flux.

（比較例１５、実施例１５）

(Comparative Example 15, Example 15)

  Similarly, Comparative Example 15 and Example 15 created as light emitting devices are light emitting devices having a color temperature of about 3200K. The configuration of the light emitting device is the same as that of Comparative Example 11 and Example 11 except for the blending ratio of the phosphors. Table 7 shows the characteristics of the light emitting devices of Example 15 and Comparative Example 15, and FIG. 11 shows the normalized emission spectra of the light emitting devices of Example 15 and Comparative Example 15.

As shown in these figures, Example 15 has about 4% higher luminous flux than Comparative Example 15. At this time, λ _{p in} Example 15 is 601.5 nm, λ _p30% −λ _p is 85 nm or less, and there are few long wave components. In addition, I _{550 nm} is 70% or less, and in comparison with the comparative example, Ra is equal to or higher, and the luminous flux is higher in the example. High color rendering and high luminous flux.

（比較例１６、１７、実施例１６、１７）

(Comparative Examples 16 and 17, Examples 16 and 17)

  Similarly, Comparative Example 16 and Example 16 produced as light emitting devices are light emitting devices in which the color temperature is about 3400K, and Comparative Example 17 and Example 17 are about 3500K. The configuration of the light emitting device is the same as that of Comparative Example 11 and Example 11 except for the blending ratio of the phosphors. Table 8 shows the characteristics of the light emitting devices of Example 16 and Comparative Example 16, Table 9 shows the characteristics of the light emitting devices of Example 17 and Comparative Example 17, and FIG. 12 shows the normalized light emitting devices of Example 16 and Comparative Example 16. FIG. 13 shows emission spectra of the light emitting devices of Example 17 and Comparative Example 17, respectively.

As shown in these figures, Examples 16 and 17 have about 4% higher luminous flux than Comparative Examples 16 and 17. At this time, λ _{p in} Examples 16 and 17 is 601.5.0 nm and 596.5 nm, respectively, and λ _p30% −λ _p is 85 nm or less, and there are few long wave components. In addition, I _{550 nm} is 76.5% or less, and compared to the comparative example, Ra is equal to or higher, but the luminous flux is higher in the example. Each has high color rendering properties and high luminous flux.

（比較例１８、１９、実施例１８、１９）

(Comparative Examples 18 and 19, Examples 18 and 19)

  Similarly, Comparative Examples 18 and 18 produced as light emitting devices are light emitting devices having a color temperature of about 3700K, and Comparative Examples 19 and 19 are about 3800K. The configuration of the light emitting device is the same as that of Comparative Example 11 and Example 11 except for the blending ratio of the phosphors. Table 10 shows the characteristics of the light emitting devices of Example 18 and Comparative Example 18, Table 11 shows the characteristics of the light emitting devices of Example 19 and Comparative Example 19, and FIG. 14 shows the normalized light emitting devices of Example 18 and Comparative Example 18. FIG. 15 shows emission spectra of the light emitting devices of Example 19 and Comparative Example 19, respectively.

As shown in these figures, Examples 18 and 19 have about 4% higher luminous flux than Comparative Examples 18 and 19. At this time, both λ _p of Examples 18 and 19 are 596.0 nm, λ _p30% −λ _p is 85 nm or less, and there are few long wave components. In addition, I _{550 nm} is 81.5% or less, and compared to the comparative example, Ra is equal or higher, but the luminous flux is higher in the example. Each has high color rendering properties and high luminous flux.

（参考例２０、実施例２０）

(Reference Example 20, Example 20)

Furthermore, Reference Example 20 and Example 20 were the same as Comparative Example 11 and Example 11 except that Lu ₃ Al ₅ O ₁₂ : Ce of Reference Example 2 was used as the green phosphor, and the color temperature was about 3000 K. The light emitting device was constructed. The emission characteristics are shown in Table 12, and the emission spectra of Example 20 and Reference Example 20 are shown in FIG. In Table 12, since a green phosphor having a short wavelength is used, Ra is as high as about 88. The maximum emission peak wavelength is about 610 nm, and λ _p30% −λ _p is 85 nm or less, and there are few long wave components. In addition, I _{550 nm} is 64% or less, and it can be seen that the luminous flux is 6% higher than that of Reference Example 20 even though Ra is 80 or more.

（実施例２１〜２５）

(Examples 21 to 25)

Examples 21 to 25 are light emitting devices manufactured with the same configuration as that of Example 11 except that the red phosphor used was changed to the phosphor of Examples 2 to 6. Table 13 shows the emission characteristics, FIG. 17 shows the emission spectra of Examples 21 to 22, and FIG. 18 shows the emission spectra of Examples 23 to 25, respectively. As shown in these figures, the maximum emission peak wavelength is about 600 nm, λ _p30% −λ _p is 85 nm or less, and there are few long wave components. In addition, _I550nm is 64% or less, and the light flux is 6 to 10% higher even though Ra is 80 or more.

  In all the examples, the blue intensity at 430 to 470 nm is less than 120%.

  As described above, according to the light emitting device according to the embodiment, it is possible to achieve both color rendering properties and light emission efficiency by optimizing the spectrum shape of the mixed color light. The light-emitting device preferably uses a SCASN phosphor as a red phosphor by combining a blue-emitting LED, a green phosphor, and a red phosphor. Further, by controlling the emission spectrum of the SCASN phosphor, it is possible to achieve both color rendering properties and efficiency.

  The semiconductor light emitting device of the present invention is a light source for illumination, LED display, backlight light source, traffic light, illumination switch, various sensors, various indicators, etc., which are particularly excellent in light emission characteristics using blue light emitting diodes or ultraviolet light emitting diodes as excitation light sources. Can be suitably used.

DESCRIPTION OF SYMBOLS 100 ... Light-emitting device, 10 ... Light emitting element, 70 ... Phosphor, 50 ... Sealing member, 60 ... Conductive wire, 40 ... Package, 20, 30 ... Lead electrode

Claims (11)

A light emitting element;
A first phosphor that emits fluorescence having an emission peak in a range of 610 to 650 nm when excited by light from the light emitting element;
A second phosphor that emits fluorescence having an emission peak in a range of 500 to 560 nm when excited by light from the light emitting element;
With
A semiconductor light emitting device that emits mixed light of light from the light emitting element and fluorescence from the first phosphor and the second phosphor,
The emission spectrum of the mixed color light has an emission peak in a wavelength region of 580 nm or more and 620 nm or less,
Semiconductor light emission characterized in that the difference between the emission wavelength at which the emission intensity of the mixed color light is 30% of the emission intensity at the peak and the emission peak wavelength at the peak is less than 85 nm in the wavelength region greater than 620 nm apparatus. The semiconductor light emitting device according to claim 1,
Formula of the first _{phosphor, Sr t Ca v Eu w Al} x Si y N z (0.8 <t <1.0,0 <v <0.19,0.005 <w ≦ 0. 03, t + v + w <1, 0.90 ≦ x ≦ 1.1, 0.90 ≦ y ≦ 1.1, 2.5 ≦ z ≦ 3.5). The semiconductor light emitting device according to claim 2,
A semiconductor light emitting device characterized in that a half width of an emission spectrum of the first phosphor is 85 nm or less and a reflectance at 550 nm is 30% or less. It is a semiconductor light-emitting device as described in any one of Claims 1-3,
A semiconductor light emitting device having a color temperature of 2500 K or more and less than 4000 K and an average color rendering index Ra of 80 or more. The semiconductor light-emitting device according to claim 1,
A semiconductor light emitting device having a color temperature of 2500 K or more and less than 2850 K, an emission intensity at the emission peak wavelength of 100%, and an emission intensity of 550 nm of 59% or less. The semiconductor light-emitting device according to claim 1,
A semiconductor light emitting device having a color temperature of 2850 K or more and less than 3050 K, an emission intensity at the emission peak wavelength of 100%, and an emission intensity at 550 nm of 64% or less. The semiconductor light-emitting device according to claim 1,
A semiconductor light emitting device having a color temperature of 3050K or more and less than 3250K, an emission intensity at the emission peak wavelength of 100%, and an emission intensity at 550 nm of 70% or less. The semiconductor light-emitting device according to claim 1,
A semiconductor light emitting device having a color temperature of 3250 K or more and less than 3550 K, an emission intensity at the emission peak wavelength of 100%, and an emission intensity at 550 nm of 76.5% or less. The semiconductor light-emitting device according to claim 1,
A semiconductor light emitting device having a color temperature of 3550 K or more and less than 4000 K, an emission intensity at the emission peak wavelength of 100%, and an emission intensity at 550 nm of 81.5% or less. A semiconductor light-emitting device according to claim 1,
The general formula of the second phosphor is Lu ₃ Al ₅ O ₁₂ : Ce, Y ₃ (Al, Ga) ₅ O ₁₂ : Ce, (Lu, Y, Gd, Tb) ₃ (Al, Ga) ₅ O ₁₂ : A semiconductor light emitting device represented by any one of Ce. It is a semiconductor light-emitting device as described in any one of Claims 1-10,
The light emission peak wavelength of light from the light emitting element is 430 to 470 nm, the light emission intensity at the light emission peak wavelength in the wavelength region of 580 nm or more and 620 nm or less is 100%, and the light emission intensity of the light from the light emitting element is less than 120%. A semiconductor light emitting device.

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