JP4991027B2 - Oxynitride phosphor and light emitting device using the same - Google Patents

Description

The present invention relates to a phosphor that emits light by being excited by electromagnetic waves such as light, electron beams, and X-rays, heat, and the like. And it is related with the fluorescent substance used for this light-emitting device. In particular, the present invention relates to white and multicolor light emitting devices using semiconductor light emitting elements.

A light-emitting device using a light-emitting element emits light with a small color, high power efficiency, and vivid colors. Also,
Since the light-emitting element is a semiconductor element, there is no fear of a broken ball. Further, it has excellent initial driving characteristics and is strong against vibration and repeated on / off lighting. Because of such excellent characteristics, light-emitting devices using semiconductor light-emitting elements such as LEDs (Light Emitting Diodes) and LDs (Laser Diodes) are used as various light sources.

  A part or all of the light of the light emitting element is converted in wavelength by a phosphor, and the emission color different from the light of the light emitting element is emitted by mixing and emitting the wavelength converted light and the light of the light emitting element that is not wavelength converted. Light emitting devices that emit light have been developed.

  Among these light emitting devices, a light emitting device that emits white light (hereinafter referred to as “white light emitting device”) is required in a wide range of fields such as lighting such as a fluorescent lamp, in-vehicle lighting, display, and backlight for liquid crystal. Yes. Further, there is a demand for light-emitting devices having a pastel color or the like by combining a semiconductor light-emitting element and a phosphor.

  The emission color of a light emitting device using a white semiconductor light emitting element is obtained by the principle of light color mixing. The blue light emitted from the light emitting element enters the phosphor layer, and after being repeatedly absorbed and scattered several times in the layer, is emitted to the outside. On the other hand, the blue light absorbed by the phosphor serves as an excitation light source and emits yellow fluorescence. This yellow light and blue light are mixed and appear as white to the human eye.

For example, a light emitting element that emits blue light (hereinafter referred to as “blue light emitting element”) is used as the light emitting element, and a phosphor is thinly coded on the surface of the blue light emitting element. The light emitting element is a blue light emitting element using an InGaN-based material. As the phosphor, a YAG phosphor represented by a composition formula of (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce is used.

  In recent years, a white light emitting device using a light emitting element in a short wavelength region of visible light and combining a phosphor emitting blue light and a YAG phosphor emitting yellow light has been reported. In this case, the YAG phosphor that emits yellow light is hardly excited by light in the short wavelength region of visible light and does not emit light. For this reason, the blue phosphor is excited by the light emitting element to emit blue light. Next, the YAG phosphor is excited by the blue light and emits yellow light. As a result, white light is emitted by mixing the blue light of the blue phosphor and the yellow-green to yellow light of the YAG phosphor.

  Various phosphors have been developed for use in the light emitting device.

  For example, oxide phosphors using rare earth elements as the emission center have been widely known and some of them have been put into practical use. However, nitride phosphors and oxynitride phosphors have not been studied much, and only a few research reports have been made compared to oxide phosphors. For example, there is an oxynitride glass phosphor represented by Si—O—N, Mg—Si—O—N, Ca—Al—Si—O—N, or the like (see Patent Document 1). Further, there is an oxynitride glass phosphor represented by Ca—Al—Si—O—N activated with Eu (see Patent Document 2).

JP 2001-214162 A JP 2002-76434 A

However, conventional phosphors have low emission luminance and are insufficient for use in light emitting devices. In a light-emitting device that uses a light-emitting element in the ultraviolet region as an excitation light source, it is a two-stage excitation in which a blue phosphor is excited by the light-emitting element and a YAG phosphor is excited by the excitation light. Hard to get. Therefore, there is a demand for a phosphor that is directly wavelength-converted by light in the short wavelength region of visible light and emits blue-green to yellow.

  In addition, a white light emitting device using a light emitting element in a short wavelength region of visible light and a phosphor is not manufactured with an appropriate phosphor, and a light emitting device that can withstand practical use is not commercially available. For this reason, a phosphor that efficiently emits light in the short wavelength region of visible light is required.

  In addition, a white light emitting device including a blue light emitting element and a YAG phosphor emits white light in a mixed color of blue light near 460 nm and yellow-green light near 565 nm. The emission intensity is insufficient.

  Furthermore, the oxynitride phosphors and the like disclosed in Patent Documents 1 and 2 have low emission luminance and are insufficient for use in a light emitting device. Moreover, since the phosphor of oxynitride glass is a glass body, it is generally difficult to process.

  Accordingly, an object of the present invention is to provide a light-emitting device using a phosphor having a luminescent color from blue-green to green that is excited and excited by an excitation light source in the ultraviolet to visible light region. It is another object of the present invention to provide a light emitting device with high luminous efficiency and excellent reproducibility.

In order to solve the above-described problems, the present invention uses at least one rare earth element that essentially requires Eu as an activator R, and essentially contains Ba selected from the group consisting of Ca, Sr, Ba, and Zn. A Group II element that is at least one or more, and a Group IV element that is at least one selected from the group consisting of C, Si, Ge, Sn, Ti, Zr, and Hf and that is essentially one or more Si. An oxynitride phosphor containing at least Ba in a molar ratio with respect to the Group II element, the Group II element: Ba = 1: 0.76 to 1: 1; The R relates to an oxynitride phosphor having a molar ratio of the Group II element: R = 1: 0.005 to 1: 0.15 with respect to the Group II element. Thereby, a phosphor with high luminance can be provided. Further, it is possible to provide a phosphor that absorbs part of light from an excitation light source having an emission wavelength in the short wavelength region from ultraviolet to visible light, is wavelength-converted, and has an emission color from blue-green to green. .

  When the oxynitride phosphor containing the above element is irradiated with light from an excitation light source having an emission wavelength in the short wavelength region from ultraviolet to visible light, the oxynitride phosphor is excited, and the light from the excitation light source Absorb some. The oxynitride phosphor in which a part of the light from the excitation light source is absorbed performs wavelength conversion. The wavelength-converted light has an emission peak wavelength from blue green to green. Accordingly, a light emitting device that emits light in a predetermined color can be provided. The oxynitride phosphor absorbs part of the light from the light emitting element and has an emission spectrum having an emission peak wavelength in the blue-green to green-based region. In addition, the oxynitride phosphor has high light emission efficiency, and can emit light from the light emitting element very efficiently.

  The oxynitride phosphor includes O and N in the composition, and the weight ratio of O to N is 1 to 0, and N is 0.2 to 2.1. The present invention relates to a nitride phosphor. Thereby, it is possible to provide a phosphor that is excited by light from the excitation light source and has a light emission color from green to yellow.

The oxynitride _{phosphor, L X M Y O Z N} ((2/3) X + (4/3) Y- (2/3) Z): R, _{or, L X M Y Q T O} Z N _{((2/3) X + (4/3) Y + T- (2/3) Z)} : R (L is at least one or more of Ba which is essential from the group consisting of Ca, Sr, Ba, Zn. It is a certain group II element, and M is a group IV element which is at least one or more elements including Si selected from the group consisting of C, Si, Ge, Sn, Ti, Zr, and Hf. And at least one group III element selected from the group consisting of B, Al, Ga and In, O is an oxygen element, N is a nitrogen element, R must contain Eu. And at least one rare earth element, 0.5 <X <1.5, 1.5 <Y <2.5, 0 <T <. .5,1.5 <represented by the general formula Z <2.5.). The oxynitride phosphor is excited by excitation light in a short wavelength region from ultraviolet to visible light, and has an emission peak wavelength from green to yellow. Further, the oxynitride phosphor has equal or higher stability than the YAG phosphor. Furthermore, since the oxynitride phosphor is not a glass body (amorphous) and the light emitting part is a crystalline powder or granule, it is easy to manufacture and process. By setting the X, Y, and Z within the above ranges, it is possible to provide a phosphor with good luminous efficiency. That is, within the above range, a crystal layer having substantially light emitting properties is formed. On the other hand, when it is out of the above range, the light emission efficiency is lowered.

The _{composition, L X M Y O Z N} ((2/3) X + (4/3) Y- (2/3) Z-α): R, _{or, L X M Y Q T O} Z N (( _{2/3) X + (4/3) Y + T− (2/3) Z−α)} : R (0 ≦ α <1). This is because the oxynitride phosphor may be deficient in nitrogen. However, the closer α is to 0, the better the crystallinity and the higher the emission luminance.
The present invention relates to an oxynitride phosphor represented by the following general formula.
L _X M _Y O _Z N _{((2/3) X + (4/3) Y- (2/3) Z)} : R
(L is a Group II element that is at least one or more elements that require Ba selected from the group consisting of Ca, Sr, Ba, and Zn. M is C, Si, Ge, Sn, Ti, Zr, It is at least one or more group IV elements essential for Si selected from the group consisting of Hf, O is an oxygen element, N is a nitrogen element, R is at least Eu. One or more rare earth elements, 0.5 <X <1.5, 1.5 <Y <2.5, 1.5 <Z <2.5, where X = 1, Y = 2 and Z = 2 are excluded.)

  X, Y, and Z are preferably X = 1, Y = 2, and Z = 2. This is because at the time of the composition, crystallinity is improved and luminous efficiency is increased.

  70% or more of R is preferably Eu. The rare earth element R is preferably Eu since it has high luminous efficiency. This is because high luminous efficiency can be obtained by using the Eu amount within this range.

  The oxynitride phosphor is excited by light from an excitation light source having an emission peak wavelength at 360 to 480 nm and has an emission peak wavelength longer than the emission peak wavelength. About the body. This is because a phosphor with high luminous efficiency can be provided by using an excitation light source in this range. As the excitation light source, one having an emission peak wavelength at 240 to 480 nm can be used. Among these, it is preferable to use an excitation light source having an emission peak wavelength at 360 to 470 nm. In particular, it is preferable to use an excitation light source having a wavelength of 380 to 420 nm or 450 to 470 nm used in semiconductor light emitting devices.

  The oxynitride phosphor has an emission peak wavelength in a blue-green to green region. A YAG phosphor having an emission peak wavelength from yellow green to yellow emits little light even when emitted using excitation light near 400 nm. However, the oxynitride phosphor according to the present invention excites the region. High light emission efficiency is exhibited by light. In addition, when blue light is used as the excitation light source, high luminous efficiency is exhibited.

  Here, the relationship between the wavelength range of light and the color name of monochromatic light conforms to JIS Z8110. Specifically, 380 to 455 nm is blue-violet, 455 to 485 nm is blue, 485 to 495 nm is blue green, 495 to 548 nm is green, 548 to 573 nm is yellow green, 573 to 584 nm is yellow, and 584 to 610 nm is yellow red. 610-780 nm is red.

  The oxynitride phosphor is related to an oxynitride phosphor characterized in that 50% by weight or more has a crystal structure. The oxynitride phosphor has a crystal structure of at least 50% by weight or more, preferably 80% by weight or more. This indicates the ratio of the crystal phase having luminescence, and if it has 50% by weight or more of the crystal phase, light emission that can withstand practical use can be obtained. The more crystal layers, the better. Thereby, the light emission luminance can be increased, and the manufacture and processing of the oxynitride phosphor can be facilitated.

  The oxynitride phosphor has an excitation spectrum having higher intensity near 460 nm than near 350 nm. Accordingly, the use of an excitation light source near 460 nm shows higher luminous efficiency than near 350 nm.

  The present invention relates to a nitride of L (L is at least one group II element essentially containing Ba selected from the group consisting of Ca, Sr, Ba, and Zn) and a nitride of M. (M is a Group IV element that is at least one or more elements that require Si selected from the group consisting of C, Si, Ge, Sn, Ti, Zr, and Hf), and an oxide of M, A first step of mixing an oxide of R (R is at least one rare earth element that essentially includes Eu), and a second step of firing the mixture obtained by the first step A process for producing an oxynitride phosphor, wherein R is a molar ratio with respect to L, L: R = 1: 0.005 to 1: 0.15 The present invention relates to a method for producing an oxynitride phosphor. Thereby, the fluorescent substance which is easy to manufacture and process can be provided. In addition, an extremely stable phosphor can be provided. Furthermore, a phosphor with higher luminous efficiency can be provided by controlling the blending amount of R. Here, the matrix of the oxynitride phosphor may contain Li, Na, K, Rb, Cs, Mn, Re, Cu, Ag, Au, or the like. This is because these Li, Na, K, and the like can sometimes improve the light emission characteristics, for example, by increasing the particle diameter or increasing the light emission luminance. On the other hand, these Li, Na, K, etc. may be contained in the raw material composition. This is because Li, Na, K, and the like are scattered during the firing step in the production process of the oxynitride phosphor, and are hardly contained in the composition. However, Li, Na, K and the like are preferably 1000 ppm or less with respect to the weight of the oxynitride phosphor. More preferably, it is 100 ppm or less. This is because high luminous efficiency can be maintained within this range. Further, other elements may be included so as not to impair the characteristics.

  It is preferable that a nitride of R is used instead of the oxide of R or together with the oxide of R. Thereby, an oxynitride phosphor with high emission luminance can be provided.

  In the first step, it is preferable to further mix Q (Q is at least one group III element selected from the group consisting of B, Al, Ga, and In). This is because the particle size can be increased and the emission luminance can be improved.

The L nitride, the M nitride, and the M oxide are 0.5 <L nitride <1.5, 0.25 <M nitride <1.75, 2.25 <M. The present invention relates to a method for producing an oxynitride phosphor represented by a molar ratio of oxide <3.75. _{Thus, L X M Y O Z N} ((2/3) X + (4/3) Y- (2/3) Z): R, _{or, L X M Y Q T O} Z N ((2/3 _{) X + (4/3) Y + T- (2/3) Z)} : An oxynitride phosphor having a composition of R can be provided.

  It is preferable that at least part of the L nitride is substituted with at least one of an R oxide and an R nitride. Thereby, an oxynitride phosphor having high luminous efficiency can be provided.

  The present invention relates to an oxynitride phosphor produced by the above-described method for producing an oxynitride phosphor.

The present invention relates to an excitation light source having an emission wavelength in a short wavelength region from ultraviolet to visible light, and at least a part of the light from the excitation light source is absorbed, wavelength conversion is performed, and an emission color different from the emission color of the excitation light source And a phosphor having an emission peak wavelength in a blue-green to green-based region, wherein the phosphor contains an oxynitride phosphor that essentially includes Ba. The present invention relates to a light emitting device. The present invention also provides an excitation light source having an emission wavelength of 240 nm to 480 nm, which is a short wavelength region from ultraviolet to visible light, absorbs at least part of the light from the excitation light source, performs wavelength conversion, and converts the excitation light source. A phosphor having an emission color different from the emission color of the phosphor, wherein the phosphor has the general formula Ba _X Si _Y O _Z N _{((2/3) X + (4/3) Y− ( 2/3) Z)} : Eu (0.5 <X <1.5, 1.5 <Y <2.5, 0 <T <0.5, 1.5 <Z <2.5.) The Eu is mainly composed of oxynitride phosphors with a molar ratio of Ba: Eu = 1: 0.005 to 1: 0.20 and lanthanoid elements with respect to the Ba. a rare earth aluminate phosphors _{activated, M 2 Si 5 N 8:} Eu (M is, Sr, Ca, Ba, Mg , Z At least one group selected from.) And, are contained, a light emitting device, wherein the color rendering index (Ra) is 80 or more. As a result, a light emitting device with high luminous efficiency and excellent color rendering can be provided. In addition, a part of the light from the excitation light source having an emission wavelength in the short wavelength region from ultraviolet to visible light and a part of the light from the oxynitride phosphor having an emission peak wavelength in the blue to green region Thus, it is possible to provide a light emitting device that has mixed color light and has an emission color in a blue-violet to green region.

  Here, the short wavelength region from ultraviolet to visible light is not particularly limited, but refers to a region of 240 to 480 nm.

  The excitation light source is preferably a light emitting element. 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. Further, it has excellent initial driving characteristics and is strong against vibration and repeated on / off lighting. Therefore, a light-emitting device that combines a light-emitting element and an oxynitride phosphor is preferable.

  The light emitting layer of the light emitting element preferably includes a nitride semiconductor containing In. Thereby, the light emitting element emits light having an emission peak wavelength in the vicinity of 360 to 410 nm, and the oxynitride phosphor is excited by the light from the light emitting element, and exhibits a predetermined emission color. This is because the oxynitride phosphor emits strong light in the vicinity of 360 to 410 nm, and thus a light emitting element in the wavelength region is required. In addition, since the emission spectrum width can be narrowed, the oxynitride phosphor can be excited efficiently, and the emission spectrum that does not substantially affect the color tone change from the light emitting device. Can be released.

  The oxynitride phosphor is preferably the above-described oxynitride phosphor.

  The phosphor includes a second phosphor used together with the oxynitride phosphor, and the second phosphor includes light from the excitation light source and light from the oxynitride phosphor. The present invention relates to a light emitting device characterized in that at least a part of is converted into a wavelength and has an emission peak wavelength in a visible light region. Thus, a light emitting device having a light emission color in the visible light region can be provided by mixing the light from the excitation light source, the light of the oxynitride phosphor, and the light of the second phosphor. The light emitting device can emit a desired light emission color in a wavelength range from the emission color of the excitation light source to the emission color of the oxynitride phosphor or the emission color of the second phosphor.

  The second phosphor relates to a light emitting device having at least one emission peak wavelength from a blue region to a green, yellow, and red region. This is because the light emitting device can exhibit a desired emission color. In particular, combining the three primary colors of blue-green to green of the oxynitride phosphor excited by an excitation light source having an emission peak wavelength in the short wavelength region from ultraviolet to visible light, and blue and red of the second phosphor. This is because various emission colors can be realized. A blue-violet to blue-based light from the blue light-emitting element, a blue-green to green-based light emitted from the oxynitride phosphor wavelength-converted by the light from the light-emitting element, By mixing the yellowish green to red light of the phosphor, it is possible to provide a light emitting device having various emission colors. However, the light emitting device may be a combination of two kinds of colors such as green and red and green and yellow.

  The second phosphors are alkaline earth halogen apatite phosphors, alkaline earth metal borate phosphors, alkaline earths mainly activated by lanthanoids such as Eu and transition metal elements such as Mn. Mainly activated by lanthanoid elements such as metal aluminate phosphors, alkaline earth silicates, alkaline earth sulfides, alkaline earth thiogallate, alkaline earth silicon nitride, germanate, or Ce It is preferably at least one selected from a rare earth aluminate, a rare earth silicate, or an organic or organic complex mainly activated by a lanthanoid element such as Eu. This is because it is possible to provide a light emitting device having high light emission efficiency such as light emission luminance and quantum efficiency. In addition, a light-emitting device with favorable color rendering properties can be provided. However, the second phosphor is not limited to the above, and phosphors that emit light in various colors can be used.

  The light emitting device emits a mixture of at least two of the light from the excitation light source, the light from the oxynitride phosphor, and the light from the second phosphor. It is preferred that Thereby, the emission color of the light emitting device can be adjusted, and a desired emission color can be emitted. In particular, when a light emitting element that emits light in the ultraviolet region is used, the human eye can hardly see the emission color in the ultraviolet region. Therefore, the color of light emitted by mixing the light from the oxynitride phosphor and the light from the second phosphor is shown. Since the luminescent color is determined only by the phosphor, the luminescent color can be easily adjusted. Here, although expressed as the second phosphor, the second phosphor is not limited to one type, and several types of phosphors may be included. This is because by including several kinds of phosphors, more delicate chromaticity adjustment is possible. In particular, when a light-emitting element in the ultraviolet region is used, light from the light-emitting element is less likely to be perceived by the human eye, so that there is little chromaticity shift due to manufacturing variations.

  The light emitting device may have an intermediate emission color from an emission peak wavelength of the excitation light source to an emission peak wavelength of the oxynitride phosphor or an emission peak wavelength of the second phosphor. The emission spectrum of the excitation light source is on the shorter wavelength side than the oxynitride phosphor or the second phosphor, and has high energy. The emission color from this high energy region to the low energy region of the oxynitride phosphor and the second phosphor can be emitted. In particular, the emission color from the emission peak wavelength of the light emitting element to the first emission peak wavelength of the oxynitride phosphor or the second emission peak wavelength of the second phosphor is shown. For example, when the emission peak wavelength of the light emitting element is in the blue region, the emission peak wavelength of the excited first phosphor is green, and the emission peak wavelength of the excited second phosphor is red, three It is possible to show a white emission color by mixing colors. As a different example, the emission peak wavelength of the light emitting element is in the ultraviolet region, the emission peak wavelength of the excited first phosphor is green, and the emission peak wavelength of the excited second phosphor is yellow and red. In some cases, it is possible to show slightly yellowish white and multicolored emission colors. By changing the blending amount of the oxynitride phosphor and the second phosphor, light emission from a color close to the emission color of the oxynitride phosphor to a color close to the emission color of the second phosphor Can show the color. Further, when the second phosphor has two or more emission peak wavelengths, the emission peak wavelength of the excitation light source, the emission peak wavelength of the oxynitride phosphor, and two or more of the second phosphor have It is a light-emitting device which shows the luminescent color between the light emission peak wavelengths. The second phosphor can be used not only in one type but also in combination of two or more types. In addition to light emitting devices that emit white light, there is also a need for light emitting devices that emit light in various colors such as pastel colors. A light-emitting device having a desired color can be provided by variously combining a green-based oxynitride phosphor, a red-based phosphor, and a blue-based phosphor. Light emitting devices with different colors are not only a method of changing the type of phosphor, but also a method of changing the blending ratio of the phosphors to be combined, a method of changing the coating method of applying the phosphor to the excitation light source, There is a method to adjust the lighting time of.

  The intermediate emission color preferably emits white light. In particular, white light emission near the locus of blackbody radiation is preferable. This is because it can be used for various purposes such as illumination, a liquid crystal backlight, and a display.

  The light-emitting device is preferably a light-emitting device having an emission spectrum having at least one emission peak wavelength at 360 to 485 nm, 485 to 548 nm, and 548 to 730 nm. By combining blue light, green light, red light, and the like, which are the three primary colors, a light emitting device that emits light in a desired color can be provided. In addition, color rendering can be improved by combining several phosphors. This is because even if the light emission is the same white, there is a yellowish white and a bluish white.

  The light emitting device is preferably a light emitting device having an emission spectrum having an emission peak wavelength of 1 or more at 360 to 485 nm and 485 to 584 nm. For example, by combining a blue light emitting element and a YAG phosphor, a light emitting device that emits white light can be obtained, but light in the vicinity of 500 nm is insufficient. Therefore, a light emitting device having excellent color rendering can be provided by further containing an oxynitride phosphor that emits light in the vicinity of 500 nm.

  The light emitting device preferably has an average color rendering index (Ra) of 80 or more. As a result, a light emitting device having excellent color rendering can be provided. In particular, a light-emitting device with improved special color rendering (R9) can be provided.

  As described above, the oxynitride phosphor according to the present invention provides a phosphor with very good luminous efficiency that is excited by light in the short wavelength region from ultraviolet to visible light and emits light from blue-green to green-based region. be able to. Further, it is possible to provide a crystalline oxynitride phosphor that is easy to manufacture and process. In addition, an oxynitride phosphor excellent in stability and reproducibility can be provided. In addition, a novel method for producing an oxynitride phosphor can be provided. Furthermore, it has a technical significance that a light emitting device having a desired emission color can be provided by combining a light emitting element, an oxynitride phosphor, and a second phosphor.

  From the above, the present invention absorbs light from an excitation light source having an emission wavelength in the short wavelength region from ultraviolet to visible light, performs wavelength conversion, and has an emission color different from the emission color from the excitation light source. The present invention relates to a nitride phosphor. The oxynitride phosphor has an emission peak wavelength in the blue-green to green-based region, and has extremely high emission efficiency. The oxynitride phosphor is extremely excellent in temperature characteristics. In particular, when the activator R is in a molar ratio with respect to the Group II element and the Group II element: R = 1: 0.005 to 1: 0.15, the highest luminous efficiency is exhibited.

  In addition, the present invention can provide a method for producing an oxynitride phosphor that is simple and excellent in reproducibility.

  The present invention also relates to a light emitting device having the oxynitride phosphor and a light emitting element. Accordingly, the light emitting device can provide a light emitting device that emits light from bright blue to green. In addition, a light-emitting device in which the oxynitride phosphor and the second phosphor, blue, green, and red three-wavelength phosphors are combined can be manufactured. Thus, the light emitting device can provide a light emitting device that emits white light and has excellent color rendering. Furthermore, it is possible to manufacture a light emitting device in which the oxynitride phosphor, the YAG phosphor that is the second phosphor, and the blue light emitting element are combined. Accordingly, it is possible to provide a light-emitting device that has excellent color rendering properties that emit white light and has extremely high light emission efficiency. As for the color rendering properties, special color rendering index (R9) showing red is improved. Therefore, the present invention has a very important technical significance that the light emitting device as described above can be provided.

Hereinafter, a light-emitting device according to the present invention, an oxynitride phosphor used in the light-emitting device, and a manufacturing method thereof will be described using embodiments and examples. However, the present invention is not limited to this embodiment and example.

  The light emitting device according to the present invention is a light emitting device having at least a light emitting element and a first phosphor and / or a second phosphor that converts the wavelength of at least part of light from the light emitting element. An example of a specific light-emitting device will be described with reference to FIG. FIG. 1 is a diagram showing a light emitting device according to the present invention. Here, JIS Z8110 is taken into consideration for the relationship between color names and chromaticity coordinates.

(Excitation light source)
As the excitation light source, one having an emission peak wavelength from the ultraviolet to the short wavelength side of visible light is used. Any excitation light source having an emission peak wavelength in this range is not particularly limited. Examples of the excitation light source include a lamp and a semiconductor light emitting element, and it is preferable to use a semiconductor light emitting element.

(Light emitting device)
The light emitting device according to the first embodiment includes a semiconductor layer 2 stacked on the top of a sapphire substrate 1, and a lead frame 13 conductively connected by a conductive wire 14 extending from positive and negative electrodes 3 formed on the semiconductor layer 2. The phosphor 11 and the coating member 12 provided in the cup of the lead frame 13a so as to cover the outer periphery of the light emitting element 10 composed of the sapphire substrate 1 and the semiconductor layer 2, the phosphor 11 and the lead And a mold member 15 that covers the outer peripheral surface of the frame 13.

  A semiconductor layer 2 is formed on the sapphire substrate 1, and positive and negative electrodes 3 are formed on the same plane side of the semiconductor layer 2. The semiconductor layer 2 is provided with a light emitting layer (not shown), and an emission peak wavelength output from the light emitting layer has an emission spectrum in the vicinity of 500 nm or less in the ultraviolet to blue region.

  The light-emitting element 10 is set on a die bonder, face-up to a lead frame 13a provided with a cup, and die-bonded (adhered). After die bonding, the lead frame 13 is transferred to a wire bonder, the negative electrode 3 of the light emitting element is wire bonded to the lead frame 13a provided with a cup with a gold wire, and the positive electrode 3 is wire bonded to the other lead frame 13b. .

  Next, it transfers to a molding apparatus and inject | pours the fluorescent substance 11 and the coating member 12 in the cup of the lead frame 13 with the dispenser of a molding apparatus. The phosphor 11 and the coating member 12 are uniformly mixed in advance at a desired ratio.

  After the phosphor 11 is injected, the lead frame 13 is immersed in a mold mold in which a mold member 15 has been injected in advance, and then the mold is removed to cure the resin, and a bullet-type light emitting device as shown in FIG. To do.

(Light emitting device)
A specific configuration of the light emitting device of the second embodiment different from the light emitting device of the first embodiment will be described in detail. FIG. 2 is a diagram showing a light emitting device according to the present invention. The light-emitting device of Embodiment 2 forms a surface-mount type light-emitting device. As the light-emitting element 101, an ultraviolet-excited nitride semiconductor light-emitting element can be used. The light-emitting element 101 can also be a blue-light-excited nitride semiconductor light-emitting element. Here, the light emitting element 101 excited by ultraviolet light will be described as an example. The light emitting element 101 uses a nitride semiconductor light emitting element having an InGaN semiconductor with an emission peak wavelength of about 370 nm as a light emitting layer. As a more specific LED element structure, an n-type GaN layer that is an undoped nitride semiconductor on a sapphire substrate, a GaN layer that forms an n-type contact layer by forming an Si-doped n-type electrode, and an undoped nitride semiconductor A single quantum well structure includes an n-type GaN layer, an n-type AlGaN layer that is a nitride semiconductor, and then an InGaN layer that constitutes a light-emitting layer. On the light emitting layer, an AlGaN layer as a p-type cladding layer doped with Mg and a GaN layer as a p-type contact layer doped with Mg are sequentially laminated. (Note that a GaN layer is formed on the sapphire substrate at a low temperature to serve as a buffer layer. In addition, the p-type semiconductor is annealed at 400 ° C. or higher after film formation). Etching exposes the surface of each pn contact layer on the same side as the nitride semiconductor on the sapphire substrate. An n-electrode is formed in a strip shape on the exposed n-type contact layer, and a translucent p-electrode made of a metal thin film is formed on almost the entire surface of the p-type contact layer that remains without being cut. A pedestal electrode is formed on the p-electrode in parallel with the n-electrode using a sputtering method.

  Next, a Kovar package 105 having a concave portion at the center and a base portion into which Kovar lead electrodes 102 are inserted and fixed in an airtight manner on both sides of the concave portion is used. A Ni / Ag layer is provided on the surface of the package 105 and the lead electrode 102. The light emitting element 101 described above is die-bonded with an Ag—Sn alloy in the recess of the package 105. With this configuration, all components of the light-emitting device can be made of an inorganic material, and the reliability of the light-emitting device can be dramatically improved even if the light emitted from the light-emitting element 101 is in the ultraviolet region or the short wavelength region of visible light. A light emitting device with high brightness is obtained.

Next, each electrode of the die-bonded light emitting element 101 and each lead electrode 102 exposed from the bottom of the package recess are electrically connected by an Ag wire 104. After sufficiently removing moisture in the recess of the package, sealing is performed with a Kovar lid 106 having a glass window 107 at the center, and seam welding is performed. In the glass window portion, CaSi ₂ O ₂ N ₂ : Eu, (Y _0.8 Gd _0.2 ) ₃ Al ₅ O ₁₂ : Ce, etc. with respect to a slurry composed of 90 wt% nitrocellulose and 10 wt% γ-alumina in advance. The color conversion member is configured by containing the phosphor 108 and applying it to the back surface of the translucent window 107 of the lid 106 and heating and curing at 220 ° C. for 30 minutes. When the light-emitting device thus formed emits light, a light-emitting diode capable of emitting white light with high luminance can be obtained. As a result, it is possible to obtain a light emitting device that is extremely easy to adjust the chromaticity and has excellent mass productivity and reliability. Hereafter, each structure of this invention is explained in full detail.

  Hereinafter, constituent members of the light emitting device according to the present invention will be described in detail.

(Phosphor 11, 108)
The phosphors 11 and 108 include oxynitride phosphors. In addition, the phosphors 11 and 108 may be a combination of an oxynitride phosphor and a second phosphor. The oxynitride phosphor according to the present invention uses at least one rare earth element essential for Eu as an activator, and requires Ba selected from the group consisting of Ca, Sr, Ba, and Zn. At least one or more Group II elements and at least one or more Group IV elements essentially comprising Si selected from the group consisting of C, Si, Ge, Sn, Ti, Zr, and Hf. contains. Although the combination of these elements is arbitrary, it is preferable to use the following composition. The oxynitride _{phosphor, L X M Y O Z N} ((2/3) X + (4/3) Y- (2/3) Z): R, _{or, L X M Y Q T O} Z N _{((2/3) X + (4/3) Y + T- (2/3) Z)} : R (L is at least one or more of Ba which is essential from the group consisting of Ca, Sr, Ba, Zn. It is a certain group II element, and M is a group IV element which is at least one or more elements including Si selected from the group consisting of C, Si, Ge, Sn, Ti, Zr, and Hf. And at least one group III element selected from the group consisting of B, Al, Ga and In, O is an oxygen element, N is a nitrogen element, R must contain Eu. At least one rare earth element, 0.5 <X <1.5, 1.5 <Y <2.5, 0 <T <0. 5,1.5 <represented by the general formula Z <2.5.). Said X, said Y, and said Z show a high brightness | luminance in this range. Among them, in the general formula, X, Y, and Z are 0.8 <X <1.2, 1.8 <Y <2.2, 0 <T <0.5, 1.7 <Z <2. .2 is particularly preferable, and an oxynitride phosphor in which X, Y, and Z are represented by X = 1, Y = 2, and Z = 2 exhibits particularly high luminance. However, it is not limited to the said range, Arbitrary things can also be used. Specifically, BaSi _1.8 Ge _0.2 O ₂ N ₂ : Eu, BaSi _1.9 Ge _0.1 O ₂ N ₂ : Eu, BaSi _1.8 C _0.2 O ₂ N ₂ : Eu, BaSi _1.9 C _0.1 O ₂ N ₂ : Eu, BaSi _1.8 Ti _0.2 O ₂ N ₂ : Eu, BaSi _1.9 Ti _0.1 O ₂ N ₂ : Eu, BaSi _1.8 Sn _{0 .2} O ₂ N ₂ : Eu, BaSi _1.9 Sn _0.1 O ₂ N ₂ : Eu, Ba _0.9 Ca _0.1 Si ₂ O ₂ N ₂ : Eu, Ba _0.9 Sr _0.1 Si ₂ O ₂ N ₂ : Eu, Ba _0.9 Zn _0.1 Si ₂ O ₂ N ₂ : Eu, Ba _0.9 Ca _0.1 Si _1.8 Ge _0.2 O ₂ N ₂ : Eu, Ba _{0 .9} Sr _0.1 Si _1.8 Ge _0.2 O ₂ N ₂ : Eu, etc. A phosphor can be used. Moreover, as shown here, this oxynitride phosphor can adjust a color tone and a brightness | luminance by changing the ratio of O and N. FIG. It is also possible to finely adjust the emission spectrum and intensity by changing the molar ratio of cation to anion represented by (L + M) / (O + N). This is possible by, for example, performing a process such as a vacuum to desorb N and O, but is not limited to this method. The composition of the oxynitride phosphor may contain at least one of Li, Na, K, Rb, Cs, Mn, Re, Cu, Ag, and Au. This is because the luminous efficiency such as luminance and quantum efficiency can be adjusted by adding them. Further, other elements may be included so as not to impair the characteristics. However, the present invention is not limited to this embodiment and examples.

  L is a Group II element that is at least one or more of Ba, which is essentially selected from the group consisting of Ca, Sr, Ba, and Zn. That is, Ba may be used alone, but various combinations such as Ba and Ca, Ba and Sr, and Ba and Ca and Sr can be changed. The mixture ratio of these Group II elements can be changed as desired.

  M is a Group IV element that is at least one or more elements including Si selected from the group consisting of C, Si, Ge, Sn, Ti, and Hf. As M, Si may be used alone, but various combinations such as Si and Ge and Si and C can be changed. This is because it is possible to provide an inexpensive phosphor with good crystallinity by using Si.

  R is a rare earth element which is at least one or more essential elements of Eu. Specifically, the rare earth elements are La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lr. Among these rare earth elements, Eu may be used alone, but one containing Eu and at least one element selected from rare earth elements can also be used. This is because elements other than Eu act as a co-activator. R preferably contains 70% or more of Eu. In particular, R is a Group II element: R = 1: 0.005 to 1: 0.15 in a molar ratio with respect to the Group II element.

Europium Eu, which is a rare earth element, is used for the emission center. In the present invention, description will be made using only Eu. However, the present invention is not limited to this, and a material co-activated with Eu can also be used. Europium mainly has bivalent and trivalent energy levels. The phosphor of the present invention uses Eu ²⁺ as an activator with respect to the base alkaline earth metal silicon nitride. Eu ²⁺ is easily oxidized and is generally commercially available with a trivalent Eu ₂ O ₃ composition.

  As the base material, each of the main components L and M can also be used. For these main components L and M, metals, oxides, imides, amides, nitrides and various salts can be used. In addition, the main components L and M may be mixed and used in advance.

Q is a Group III element that is at least one selected from the group consisting of B, Al, Ga, and In. As Q, metals, oxides, imides, amides, nitrides, various salts, and the like can be used. For example, B ₂ O ₆ , H ₃ BO ₃ , Al ₂ O ₃ , Al (NO ₃ ) ₃ .9H ₂ O, AlN, GaCl ₃ , InCl _{3 and the} like.

L nitride, M nitride, and M oxide are mixed as a base material. In the base material, Eu oxide is mixed as an activator. Weigh these in the desired amount and mix until uniform. In particular, the base material L nitride, M nitride, and M oxide are 0.5 <L nitride <1.5, 0.25 <M nitride <1.75,2. It is preferred that the oxides are mixed in a molar ratio of 25 <M oxide <3.75. These base _{materials, L X M Y O Z N} ((2/3) X + Y- (2/3) Z-α): R or _{L X M Y Q T O Z} N ((2/3) X + Y + T- _{(2/3) Z-α)} : A predetermined amount is weighed and mixed so that the composition ratio of R is obtained.

(Method for producing oxynitride phosphor)
Next, oxynitride phosphor according to the present invention, BaSi ₂ O ₂ N _2: While explaining the manufacturing method of Eu, but is not limited to this manufacturing method. FIG. 3 is a process diagram showing a method for producing an oxynitride phosphor.

  First, Ba nitride, Si nitride, Si oxide, and Eu oxide are mixed so as to obtain a predetermined blending ratio.

  Ba nitride, Si nitride, Si oxide, and Eu oxide are prepared in advance. It is better to use purified materials, but commercially available materials may be used. Specifically, an oxynitride phosphor is manufactured by the following method.

Ba nitride Ba ₃ N ₂ is used as a raw material. The raw material is preferably Ba alone, but compounds such as imide compounds, amide compounds and BaO can also be used. The raw material Ba may contain B, Ga, or the like.

Ba nitride Ba ₃ N ₂ is pulverized (P1). Ba nitride is pulverized in a glove box in an argon atmosphere or a nitrogen atmosphere.

Si nitride Si ₃ N ₄ is used as a raw material. The raw material is preferably a simple substance of Si, 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, Ca ₂ Si, SiC, or the like. The purity of the raw material Si is preferably 3N or higher, but may contain B, Ga and the like.

Si nitride Si ₃ N ₄ is pulverized (P2). Si nitride is pulverized in a glove box in an argon atmosphere or a nitrogen atmosphere.

Si oxide SiO ₂ is used as a raw material. Here, a commercially available product is used (Silicon Dioxide 99.9%, 190-09072 manufactured by Wako Pure Chemical Industries).

The Si oxide SiO ₂ is pulverized (P3).

Eu oxide Eu ₂ O ₂ is used as a raw material. As a raw material, it is preferable to use a simple substance of Eu, but a nitride compound, an imide compound, an amide compound, or the like can also be used. In particular, it is preferable to use europium nitride in addition to europium oxide. This is because oxygen or nitrogen is contained in the product.

Eu oxide Eu ₂ O ₂ is pulverized (P4).

The raw material Ba nitride Ba ₃ N ₂ , Si nitride Si ₃ N ₄ , Si oxide SiO ₂ , Eu oxide Eu ₂ O ₂ are weighed and mixed (P5). A predetermined molar amount of the raw materials is weighed so as to have a predetermined blending ratio.

  Next, a mixture of Ba nitride, Si nitride, Si oxide, and Eu oxide is fired (P6). The mixture is put into a crucible and fired.

By mixing and firing, an oxynitride phosphor represented by BaSi ₂ O ₂ N ₂ : Eu can be obtained (P7). The reaction formula of the basic constituent elements by this firing is shown in chemical formula 1.

  However, this composition is a representative composition estimated from the blending ratio, and has sufficient characteristics to withstand practical use in the vicinity of the ratio. Moreover, the composition of the target phosphor can be changed by changing the blending ratio of each raw material.

For firing, a tubular furnace, a small furnace, a high-frequency furnace, a metal furnace, or the like can be used. The firing temperature is not particularly limited, but the firing is preferably performed in the range of 1200 to 1700 ° C, more preferably 1400 to 1700 ° C. The raw material of the phosphor 11 is preferably fired using a crucible or boat made of boron nitride (BN). Besides the crucible made of boron nitride, a crucible made of alumina (Al ₂ O ₃ ) can also be used.

  Moreover, it is preferable to perform baking in a reducing atmosphere. The reducing atmosphere is a nitrogen atmosphere, a nitrogen-hydrogen atmosphere, an ammonia atmosphere, an inert gas atmosphere such as argon, or the like.

  By using the above manufacturing method, it is possible to obtain a target oxynitride phosphor.

_{Incidentally, Ba X Si Y B T O} Z N ((2/3) X + Y + T- (2/3) Z-α): oxynitride phosphor represented by Eu is be prepared as follows it can.

In advance, Eu compound is dry-mixed with B compound H ₃ BO ₃ . Europium oxide is used as the Eu compound, but metal europium, europium nitride, and the like can be used as in the other constituent elements described above. In addition, an imide compound or an amide compound can also be used as the raw material Eu. Europium oxide is preferably highly purified, but commercially available products can also be used. The compound of B is dry mixed, but can also be wet mixed. Since some of these mixtures are easily oxidized, they are mixed in a glove box in an Ar atmosphere or a nitrogen atmosphere.

The production method of the oxynitride phosphor will be described by taking the compound H ₃ BO ₃ of B as an example. Component constituent elements other than B include Li, Na, K, etc., and these compounds, for example, LiOH. H ₂ O, Na ₂ CO ₃ , K ₂ CO ₃ , RbCl, CsCl, Mg (NO ₃ ) ₂ , CaCl ₂ .6H ₂ O, SrCl ₂ .6H ₂ O, BaCl ₂ .2H ₂ O, TiOSO ₄ .H ₂ O, ZrO (NO ₃ ) ₂ , HfCl ₄ , MnO ₂ , ReCl ₅ , Cu (CH ₃ COO) ₂ .H ₂ O, AgNO ₃ , HAuCl ₄ .4H ₂ O, Zn (NO ₃ ) ₂ .6H _{2 O,} it can be used _{GeO 2, Sn (CH 3 COO} ) 2 or the like.

  Grind the mixture of Eu and B. The average particle size of the mixture of Eu and B after pulverization is preferably about 0.1 μm to 15 μm.

After performing the above-mentioned pulverization, Ba nitride, Si nitride, Si oxide, and Eu oxide containing B are substantially the same as the manufacturing process of BaSi ₂ O ₂ N ₂ : Eu described above. Mix. After the mixing, firing is performed to obtain the target oxynitride phosphor.

(Second phosphor 11, 108)
The phosphors 11 and 108 include the second phosphor together with the oxynitride phosphor. Examples of the second phosphor include alkaline earth halogen apatite phosphors, alkaline earth metal borate phosphors, alkaline earths mainly activated by lanthanoid compounds such as Eu and transition metal elements such as Mn. Mainly activated by lanthanoid elements such as metal aluminate phosphors, alkaline earth silicates, alkaline earth sulfides, alkaline earth thiogallate, alkaline earth silicon nitride, germanate, or Ce It is preferably at least one selected from a rare earth aluminate, a rare earth silicate, or an organic or organic complex mainly activated by a lanthanoid element such as Eu. As specific examples, the following phosphors can be used, but are not limited thereto.

Alkaline earth halogen apatite phosphors mainly activated by lanthanoid compounds such as Eu and transition metal elements such as Mn include M ₅ (PO ₄ ) ₃ X: R (M is Sr, Ca, Ba). X is at least one selected from F, Cl, Br and I. R is any one of Eu, Mn, Eu and Mn. Etc.).

The alkaline earth metal borate phosphor has M ₂ B ₅ O ₉ X: R (M is at least one selected from Sr, Ca, Ba, Mg, Zn. X is F, Cl , Br, or I. R is Eu, Mn, or any one of Eu and Mn.).

Alkaline earth metal aluminate phosphors include SrAl ₂ O ₄ : R, Sr ₄ Al ₁₄ O ₂₅ : R, CaAl ₂ O ₄ : R, BaMg ₂ Al ₁₆ O ₂₇ : R, BaMg ₂ Al ₁₆ O ₁₂ : R, BaMgAl ₁₀ O ₁₇ : R (R is Eu, Mn, or any one of Eu and Mn).

Examples of the alkaline earth sulfide phosphor include La ₂ O ₂ S: Eu, Y ₂ O ₂ S: Eu, and Gd ₂ O ₂ S: Eu.

Examples of rare earth aluminate phosphors mainly activated with lanthanoid elements such as Ce include Y ₃ Al ₅ O ₁₂ : Ce, (Y _0.8 Gd _0.2 ) ₃ Al ₅ O ₁₂ : Ce, Y _{3 (Al 0.8 Ga 0.2) 5 O} 12: Ce, and the like (Y, Gd) 3 (Al , Ga) YAG -based phosphor represented by the composition formula of _{5 O 12.}

Other phosphors include ZnS: Eu, Zn ₂ GeO ₄ : Mn, MGa ₂ S ₄ : Eu (M is at least one selected from Sr, Ca, Ba, Mg, Zn. X is At least one selected from F, Cl, Br, and I). M ₂ Si ₅ N ₈ : Eu, MSi ₇ N ₁₀ : Eu, M _1.8 Si ₅ O _0.2 N ₈ : Eu, M _0.9 Si ₇ O _0.1 N ₁₀ : Eu (M is , Sr, Ca, Ba, Mg, and Zn.).

  The above-mentioned second phosphor may be one or more selected from Tb, Cu, Ag, Au, Cr, Nd, Dy, Co, Ni, and Ti instead of Eu or in addition to Eu as desired. Can also be included.

  Moreover, it is fluorescent substance other than the said fluorescent substance, Comprising: The fluorescent substance which has the same performance and effect can also be used.

  As these second phosphors, phosphors having emission spectra in yellow, red, green, and blue can be used by the excitation light of the light-emitting elements 10 and 101, and yellow, blue-green, which are intermediate colors thereof, can be used. A phosphor having an emission spectrum in orange or the like can also be used. By using these second phosphors in combination with the first phosphor, light emitting devices having various emission colors can be manufactured.

For example, CaSi ₂ O ₂ N ₂ : Eu or SrSi ₂ O ₂ N ₂ : Eu that emits light from green to yellow that is the first phosphor, and blue light that is the second phosphor (Sr, Ca ) ₅ (PO ₄ ) ₃ Cl: Eu, emitting light in red (Ca, Sr) ₂ Si ₅ N ₈ : Eu, and using phosphors 11 and 108, emitting light in white with good color rendering properties It is possible to provide a light emitting device. This uses the three primary colors of red, blue, and green, so the desired white light can be achieved simply by changing the blend ratio of the first phosphor and the second phosphor. Can do. In particular, when the oxynitride phosphor and the second phosphor are irradiated with light near 460 nm as the excitation light source, the oxynitride phosphor emits light near 500 nm. Thereby, a white light-emitting device excellent in color rendering can be provided.

  The particle diameter of the phosphors 11 and 108 is preferably in the range of 1 μm to 20 μm, more preferably 2 μm to 8 μm. Particularly, 5 μm to 8 μm is preferable. A phosphor having a particle size smaller than 2 μm tends to form an aggregate. On the other hand, a phosphor having a particle size range of 5 μm to 8 μm has high light absorptivity and conversion efficiency. In this manner, the mass productivity of the light-emitting device is improved by including a phosphor having a large particle diameter and having optically excellent characteristics.

Here, the particle size 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, and then a constant pressure of dry air is flowed to read the specific surface area from the differential pressure. It is a value converted into an average particle diameter. The average particle size of the phosphor used in the present invention is preferably in the range of 2 μm to 8 μm. Moreover, it is preferable that the phosphor having this average particle diameter value is contained frequently. In addition, it is preferable that the particle size distribution is distributed in a narrow range, and in particular, particles having a fine particle size of 2 μm or less are preferable. 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.

  The arrangement place of the phosphor 108 in the light emitting device 2 can be arranged at various places in the positional relationship with the light emitting element 101. For example, the phosphor 108 can be contained in the molding material that covers the light emitting element 101. Further, the light emitting element 101 and the phosphor 108 may be arranged with a gap therebetween, or the phosphor 108 may be directly placed on the light emitting element 101.

(Coating member 12, 109)
The phosphors 11 and 108 can be attached using various coating members (binders) such as a resin that is an organic material and glass that is an inorganic material. The coating members 12 and 109 may have a role as a binder for fixing the phosphors 11 and 108 to the light emitting elements 10 and 101, the window portion 107, and the like. When an organic material is used as the coating member (binder), a transparent resin having excellent weather resistance such as an epoxy resin, an acrylic resin, or silicone is preferably used as a specific material. In particular, it is preferable to use silicone because it is excellent in reliability and the dispersibility of the phosphors 11 and 108 can be improved.

In addition, it is preferable to use an inorganic material that is close to the thermal expansion coefficient of the window portion 107 as the coating members (binders) 12 and 109 because the phosphor 108 can be satisfactorily adhered to the window portion 107. As a specific method, a precipitation method, a sol-gel method, a spray method, or the like can be used. For example, the phosphors 11 and 108 are mixed with silanol (Si (OEt) ₃ OH) and ethanol to form a slurry. After the slurry is discharged from the nozzle, the slurry is heated at 300 ° C. for 3 hours. Can be made SiO ₂ and the phosphor can be fixed to a desired place.

  In addition, an inorganic binder can be used as the coating members (binders) 12 and 109. The binder is so-called low-melting glass, is a fine particle, has little absorption with respect to radiation in the ultraviolet to visible region, and is extremely stable in the coating members (binders) 12 and 109. Is preferred.

  In addition, when a phosphor having a large particle size is attached to the coating members (binders) 12 and 109, it can be obtained by a binder, for example, silica, alumina, or a precipitation method. It is preferable to use a fine-grained alkaline earth metal pyrophosphate or orthophosphate. These binders can be used alone or mixed with each other.

  Here, a method for applying the binder will be described. In order to sufficiently enhance the binding effect, the binder is preferably wet pulverized in a vehicle to form a slurry and used as a binder slurry. The vehicle is a high viscosity solution obtained by dissolving a small amount of a binder in an organic solvent or deionized water. For example, an organic vehicle can be obtained by adding 1 wt% of nitrocellulose as a binder to butyl acetate as an organic solvent.

  The binder slurry thus obtained contains phosphors 11 and 108 to prepare a coating solution. The added amount of the slurry in the coating solution can be such that the total amount of the binder in the slurry is about 1 to 3% wt with respect to the amount of the phosphor in the coating solution. In order to suppress a decrease in the luminous flux maintenance factor, it is preferable that the amount of the binder added is small.

  The coating solution is applied to the back surface of the window portion 107. After that, hot air or hot air is blown to dry. Finally, baking is performed at a temperature of 400 ° C. to 700 ° C. to scatter the vehicle. As a result, the phosphor layer is adhered to the desired place with the binder.

(Light emitting element 10, 101)
In the present invention, the light-emitting elements 10 and 101 are preferably semiconductor light-emitting elements having a light-emitting layer capable of emitting a light emission wavelength capable of efficiently exciting the phosphor. Examples of the material of such a semiconductor light emitting device include various semiconductors such as BN, SiC, ZnSe, GaN, InGaN, InAlGaN, AlGaN, BAlGaN, and BInAlGaN. Similarly, these elements may contain Si, Zn, or the like as an impurity element to serve as a light emission center. In particular, a nitride semiconductor (for example, a nitride semiconductor containing Al or Ga, In or Ga, for example) is used as a light emitting layer material that can efficiently emit short wavelengths of visible light from the ultraviolet region that can excite the phosphors 11 and 108 efficiently. _{in X Al Y Ga 1-X} -Y N, 0 ≦ X, 0 ≦ Y as a nitride semiconductor containing, X + Y ≦ 1) can be mentioned as more preferable.

  As a semiconductor structure, a homostructure having a MIS junction, a PIN junction, a pn junction, or the like, a heterostructure, or a double hetero configuration is preferably exemplified. Various emission wavelengths can be selected depending on the semiconductor layer material and the mixed crystal ratio. Further, the output can be further improved by adopting a single quantum well structure or a multiple quantum well structure in which the semiconductor active layer is formed in a thin film that produces a quantum effect.

  When a nitride semiconductor is used for the light emitting elements 10 and 101, a material such as sapphire, spinel, SiC, Si, ZnO, GaAs, or GaN is preferably used for the semiconductor substrate. In order to form a nitride semiconductor with good crystallinity with high productivity, it is preferable to use a sapphire substrate. A nitride semiconductor can be formed on the sapphire substrate by HVPE method, MOCVD method or the like. A buffer layer made of GaN, AlN, GaAIN or the like is grown at a low temperature on the sapphire substrate to form a non-single crystal, and a nitride semiconductor having a pn junction is formed thereon.

As an example of a light emitting element capable of efficiently emitting light in an ultraviolet region having a pn junction using a nitride semiconductor, SiO ₂ is formed in a stripe shape on the buffer layer substantially perpendicular to the orientation flat surface of the sapphire substrate. GaN is grown on the stripes using EHV (Epitaxial Lateral Over Grows GaN) using the HVPE method. Subsequently, a first contact layer formed of n-type gallium nitride, a first cladding layer formed of n-type aluminum nitride / gallium, a well layer of indium nitride / aluminum / gallium, and aluminum nitride / gallium are formed by MOCVD. An active layer having a multiple quantum well structure in which a plurality of barrier layers are stacked, a second cladding layer formed of p-type aluminum nitride / gallium, and a second contact layer formed of p-type gallium nitride are sequentially stacked. Examples include a double hetero configuration. The active layer may be formed into a ridge stripe shape and sandwiched between guide layers, and a resonator end face may be provided to provide a semiconductor laser device usable in the present invention.

  Nitride semiconductors exhibit n-type conductivity without being doped with impurities. When forming a desired n-type nitride semiconductor, for example, to improve luminous efficiency, it is preferable to appropriately introduce Si, Ge, Se, Te, C, etc. as an n-type dopant. On the other hand, when forming a p-type nitride semiconductor, it is preferable to dope p-type dopants such as Zn, Mg, Be, Ca, Sr, and Ba. Since nitride semiconductors are not easily converted to p-type by simply doping with a p-type dopant, it is preferable to reduce resistance by heating in a furnace or plasma irradiation after introducing the p-type dopant. When a sapphire substrate is not used, the contact layer is exposed by etching from the p-type side to the surface of the first contact layer. A light emitting element made of a nitride semiconductor can be formed by cutting the semiconductor wafer into chips after forming electrodes on each contact layer.

  In order to form the light emitting device of the present invention with high productivity, it is preferable to form the phosphors 11 and 108 using a resin when the phosphors 11 and 108 are fixed to the light emitting elements 10 and 101. In this case, taking into consideration the emission wavelength from the phosphors 11 and 108 and the deterioration of the translucent resin, the light-emitting elements 10 and 101 have an emission spectrum in the ultraviolet region, and the emission peak wavelength is 360 nm or more and 420 nm or less. And those having a wavelength of 450 nm to 470 nm are preferable.

Here, in the semiconductor light emitting devices 10 and 101 used in the present invention, the sheet resistance of the n-type contact layer formed at an impurity concentration of 10 ¹⁷ to 10 ²⁰ / cm ³ and the sheet resistance of the translucent p electrode are It is preferable to adjust so that Rp ≧ Rn. The n-type contact layer is preferably formed to a film thickness of, for example, 3 to 10 μm, more preferably 4 to 6 μm, and the sheet resistance is estimated to be 10 to 15Ω / □, so that Rp at this time is the sheet resistance value. It is good to form in a thin film so that it may have the above sheet resistance values. The translucent p-electrode may be formed of a thin film having a thickness of 150 μm or less.

  Further, when the translucent p-electrode is formed of a multilayer film or alloy composed of one kind selected from the group of gold and platinum group elements and at least one other element, it is contained. When the sheet resistance of the translucent p-electrode is adjusted by the content of the gold or platinum group element, stability and reproducibility are improved. Since gold or a metal element has a high absorption coefficient in the wavelength region of the semiconductor light emitting device used in the present invention, the smaller the amount of gold or platinum group element contained in the translucent p-electrode, the better the transparency. In the conventional semiconductor light emitting device, the relationship of sheet resistance is Rp ≦ Rn. However, in the present invention, Rp ≧ Rn, and therefore the translucent p-electrode is formed in a thin film as compared with the conventional one. However, thinning can be easily performed by reducing the content of gold or platinum group elements.

  As described above, in the semiconductor light emitting devices 10 and 101 used in the present invention, the sheet resistance RnΩ / □ of the n-type contact layer and the sheet resistance RpΩ / □ of the translucent p electrode have a relationship of Rp ≧ Rn. Preferably. It is difficult to measure Rn after forming the semiconductor light emitting devices 10 and 101, and it is practically impossible to know the relationship between Rp and Rn. However, from the state of the light intensity distribution during light emission, what Rp and You can know if it is related to Rn.

  When the translucent p-electrode and the n-type contact layer have a relationship of Rp ≧ Rn, providing a p-side pedestal electrode in contact with the translucent p-electrode and having an extended conductive portion further improves external quantum efficiency. Can be achieved. There is no limitation on the shape and direction of the extended conductive portion, and when the extended conductive portion is on the satellite, it is preferable because the area for blocking light is reduced, but a mesh shape may be used. Further, the shape may be a curved shape, a lattice shape, a branch shape, or a hook shape in addition to the straight shape. At this time, since the light shielding effect increases in proportion to the total area of the p-side pedestal electrode, it is preferable to design the line width and length of the extended conductive portion so that the light shielding effect does not exceed the light emission enhancing effect.

(Light emitting element 10, 101)
As the light-emitting elements 10 and 101, a light-emitting element that emits blue light different from the above-described ultraviolet light-emitting element can be used. The light emitting elements 10 and 101 that emit blue light are preferably group III nitride compound light emitting elements. The light-emitting elements 10 and 101 include, for example, an n-type GaN layer in which Si is undoped, an n-type contact layer made of n-type GaN in which Si is doped, an undoped GaN layer, and multiple quanta on a sapphire substrate 1. Light emitting layer with a well structure (GaN well layer / InGaN well layer quantum well structure), p-clad layer made of p-type GaN made of Mg-doped p-type GaN, p-type made of p-type GaN doped with Mg It has a laminated structure in which contact layers are sequentially laminated, and electrodes are formed as follows. However, a light emitting element different from this configuration can also be used.

  The p ohmic electrode is formed on almost the entire surface of the p-type contact layer, and the p pad electrode is formed on a part of the p ohmic electrode.

  The n-electrode is formed in the exposed portion by removing the undoped GaN layer from the p-type contact layer by etching to expose a part of the n-type contact layer.

  In the present embodiment, the light emitting layer having a multiple quantum well structure is used. However, the present invention is not limited to this, and for example, a single quantum well structure using InGaN may be used. GaN doped with Zn may be used.

  The light emitting layers of the light emitting elements 10 and 101 can change the main light emission peak wavelength in the range of 420 nm to 490 nm by changing the In content. The emission peak wavelength is not limited to the above range, and those having an emission peak wavelength in the range of 360 to 550 nm can be used.

(Coating member 12, 109)
The coating member 12 (light transmissive material) is provided in the cup of the lead frame 13 and is used by mixing with the phosphor 11 that converts the light emission of the light emitting element 10. Specific materials for the coating member 12 include transparent resins, silica sol, glass, inorganic binders, and the like that are excellent in temperature characteristics and weather resistance, such as epoxy resins, urea resins, and silicone resins. Further, a diffusing agent, barium titanate, titanium oxide, aluminum oxide or the like may be contained together with the phosphor. Moreover, you may contain a light stabilizer and a coloring agent.

(Lead frame 13)
The lead frame 13 includes a mount lead 13a and an inner lead 13b.

  The mount lead 13a is for placing the light emitting element 10 thereon. The upper portion of the mount lead 13a has a cup shape, and the light emitting element 10 is die-bonded in the cup, and the outer peripheral surface of the light emitting element 10 is covered with the phosphor 11 and the coating member 12 inside the cup. . A plurality of light emitting elements 10 can be arranged in the cup, and the mount lead 13 a can be used as a common electrode of the light emitting elements 10. In this case, sufficient electrical conductivity and connectivity with the conductive wire 14 are required. Die bonding (adhesion) between the light emitting element 10 and the cup of the mount lead 13a can be performed with a thermosetting resin or the like. Examples of the thermosetting resin include an epoxy resin, an acrylic resin, and an imide resin. In addition, Ag-ace, carbon paste, metal bumps, or the like can be used for die-bonding and electrical connection with the mount lead 13a by the face-down light emitting element 10 or the like. An inorganic binder can also be used.

  The inner lead 13b is intended to be electrically connected to the conductive wire 14 extending from the electrode 3 of the light emitting element 10 disposed on the mount lead 13a. The inner lead 13b is preferably disposed at a position away from the mount lead 13a in order to avoid a short circuit due to electrical contact with the mount lead 13a. In the case where the plurality of light emitting elements 10 are provided on the mount lead 13a, it is necessary that the conductive wires be arranged so as not to contact each other. The inner lead 13b is preferably made of the same material as the mount lead 13a, and iron, copper, iron-containing copper, gold, platinum, silver, or the like can be used.

(Conductive wire)
The conductive wire 14 is for electrically connecting the electrode 3 of the light emitting element 10 and the lead frame 13. The conductive wire 14 preferably has good ohmic properties, mechanical connectivity, electrical conductivity, and thermal conductivity with the electrode 3. Specific materials for the conductive wire 14 are preferably metals such as gold, copper, platinum, and aluminum, and alloys thereof.

(Mold member)
The mold member 15 is provided to protect the light emitting element 10, the phosphor 11, the coating member 12, the lead frame 13, the conductive wire 14, and the like from the outside. In addition to the purpose of protection from the outside, the mold member 15 also has the purposes of widening the viewing angle, relaxing the directivity from the light emitting element 10, and converging and diffusing the emitted light. In order to achieve these objects, the mold member can have a desired shape. Further, the mold member 15 may have a structure in which a plurality of layers other than a convex lens shape and a concave lens shape are stacked. As a specific material of the mold member 15, a material excellent in translucency, weather resistance, and temperature characteristics such as epoxy resin, urea resin, silicone resin, silica sol, and glass can be used. The mold member 15 can contain a diffusing agent, a colorant, an ultraviolet absorber, and a phosphor. As the diffusing agent, barium titanate, titanium oxide, aluminum oxide or the like is preferable. In order to reduce the resilience of the material with the coating member 12, it is preferable to use the same material in consideration of the refractive index.

  Hereinafter, the phosphor and the light emitting device according to the present invention will be described with reference to examples, but the present invention is not limited to these examples.

  The temperature characteristics are shown as relative luminance with the emission luminance at 25 ° C. being 100%. The particle size indicates the average particle size described above. S. S. S. No. (Fisher Sub Sieve Sizer's No.) Value by air permeation method.

  Examples of the present invention will be described in detail below.

(Phosphor)
FIG. 4 is a diagram showing an emission spectrum when the oxynitride phosphors of Examples 1 to 5 are excited at Ex = 400 nm. FIG. 5 is a diagram showing an emission spectrum when the oxynitride phosphors of Examples 1 to 5 are excited at Ex = 460 nm. FIG. 6 is a diagram showing excitation spectra of the oxynitride phosphors of Examples 1 to 5. FIG. 7 is a diagram showing the reflection spectra of the oxynitride phosphors of Examples 1 to 5. FIG. 8 is an SEM photograph taken of the oxynitride phosphor of Example 1. FIG. 8A shows a picture taken at 1000 times, and FIG. 8B shows a picture taken at 5000 times.

In Examples 1 to 5, a part of Ba is replaced with Eu, and the Eu concentration is changed. Example 1 is Ba _0.97 Eu _0.03 Si ₂ O ₂ N ₂ . Example 2 is Ba _0.95 Eu _0.05 Si ₂ O ₂ N ₂ . Example 3 is Ba _0.90 Eu _0.10 Si ₂ O ₂ N ₂ . Example 4 is Ba _0.85 Eu _0.15 Si ₂ O ₂ N ₂ . Example 5 is Ba _0.80 Eu _0.20 Si ₂ O ₂ N ₂ .

First, Ba ₃ N ₂ , Si ₃ N ₄ , SiO ₂ and Eu ₂ O ₃ were used as raw materials. The raw materials were each pulverized to 0.1 to 3.0 μm. After pulverization, Example 1 used the following quantities of raw materials so as to have the above composition. Here, the molar ratio of Eu to Ba is Ba: Eu = 0.97: 0.03.
Ba ₃ N ₂ : 5.60 g
Si ₃ N ₄ : 1.88 g
SiO ₂ : 2.31 g
Eu ₂ O ₃ : 0.21 g
After weighing the above quantity, Ba ₃ N ₂ , Si ₃ N ₄ , SiO ₂ , Eu ₂ O ₃ were mixed until uniform.

  The above compounds were mixed, put in a boron nitride crucible in an ammonia atmosphere, and baked at about 1500 ° C. for about 5 hours.

Thereby, the target oxynitride phosphor was obtained. The theoretical composition of the obtained oxynitride phosphor is BaSi ₂ O ₂ N ₂ : Eu.

  When the weight% of O and N of the oxynitride phosphor of Example 1 was measured, O was 12.1% by weight and N was 8.9% by weight in the total amount. The weight ratio of O and N is O: N = 1: 0.74.

  The oxynitride phosphor according to the example is fired in an ammonia atmosphere using a crucible made of boron nitride. It is not very preferable to use a metal crucible for the crucible. This is because when a metal crucible is used, it is considered that the crucible is eroded and the light emission characteristics are deteriorated. Therefore, it is preferable to use a ceramic crucible such as alumina.

In Example 2, the Eu compounding ratio was changed. This is an oxynitride phosphor in which a part of Ba is substituted with Eu. The finely crushed powder was weighed as follows. Here, the molar ratio of Eu to Ba is Ba: Eu = 0.95: 0.05.
Ba ₃ N ₂ : 5.48 g
Si ₃ N ₄ : 1.91 g
SiO ₂ : 2.28 g
Eu ₂ O ₃ : 0.35 g
Under the same conditions as in Example 1, the raw materials were mixed and fired.

In Example 3, the blending ratio of Eu was changed. This is an oxynitride phosphor in which a part of Ba is substituted with Eu. The finely crushed powder was weighed as follows. Here, the molar ratio of Eu to Ba is Ba: Eu = 0.90: 0.10.
Ba ₃ N ₂ : 5.18 g
Si ₃ N ₄ : 1.97 g
SiO ₂ : 2.18 g
Eu ₂ O ₃ : 0.69 g
Under the same conditions as in Example 1, the raw materials were mixed and fired.

In Example 4, the Eu compounding ratio was changed. This is an oxynitride phosphor in which a part of Ba is substituted with Eu. The finely crushed powder was weighed as follows. Here, the molar ratio of Eu to Ba is Ba: Eu = 0.85: 0.15.
Ba ₃ N ₂ : 4.87 g
Si ₃ N ₄ : 2.03 g
SiO ₂ : 2.09 g
Eu ₂ O ₃ : 1.03 g
Under the same conditions as in Example 1, the raw materials were mixed and fired.

In Example 5, the Eu compounding ratio was changed. This is an oxynitride phosphor in which a part of Ba is substituted with Eu. The finely crushed powder was weighed as follows. Here, the molar ratio of Eu to Ba is Ba: Eu = 0.80: 0.20.
Ba ₃ N ₂ : 4.57 g
Si ₃ N ₄ : 2.10 g
SiO ₂ : 1.99 g
Eu ₂ O ₃ : 1.37 g
Under the same conditions as in Example 1, the raw materials were mixed and fired.

  The fired products of Examples 1 to 5 are all crystalline powders or granules. The particle size was approximately 1-5 μm.

  Table 1 shows the light emission characteristics when the oxynitride phosphors of Examples 1 to 5 were excited at Ex = 400 nm.

  Excitation spectra of the oxynitride phosphors of Examples 1 to 5 were measured. As a result of the measurement, Examples 1 to 4 are excited more strongly at 370 nm to 470 nm than near 350 nm.

  The reflection spectra of the oxynitride phosphors of Examples 1 to 5 were measured. As a result of measurement, Examples 1 to 5 show a high absorption rate from 290 nm to 470 nm. Therefore, it is possible to efficiently absorb light from an excitation light source from 290 nm to 470 nm and perform wavelength conversion.

  As an excitation light source, light in the vicinity of Ex = 400 nm was irradiated to the oxynitride phosphors of Examples 1 to 5 to be excited. The oxynitride phosphor of Example 1 has an emission color in a green region having a color tone x = 0.106, a color tone y = 0.471, and an emission peak wavelength λp = 496 nm. Example 2 has a light emission color in a green region having a color tone x = 0.121, a color tone y = 0.481, and λp = 498 nm. Example 3 has a light emission color in a green region having a color tone x = 0.247, a color tone y = 0.477, and λp = 500 nm. All of the oxynitride phosphors of Examples 1 to 3 showed higher luminous efficiency than the conventional phosphors. In particular, the oxynitride phosphors of Examples 1 to 4 showed higher luminous efficiency than Example 5. In Examples 2 to 5, the light emission luminance and quantum efficiency of Example 1 are assumed to be 100%, and are expressed as relative values.

  Table 2 shows the temperature characteristics of the oxynitride phosphor of Example 1. The temperature characteristic is indicated by a relative luminance where the emission luminance at 25 ° C. is 100%. The excitation light source is light near Ex = 400 nm.

  From this result, when the oxynitride phosphor is heated to 100 ° C., it maintains a very high emission luminance of 88.8%, and even when heated to 200 ° C., it is as high as 64.7%. Emission brightness is maintained. Accordingly, the oxynitride phosphor exhibits extremely good temperature characteristics.

  When X-ray diffraction images of these oxynitride phosphors were measured, all showed sharp diffraction peaks, and it was revealed that the obtained phosphor was a crystalline compound having regularity.

<Light emitting device>
A light emitting device of Example 1 was manufactured using the oxynitride phosphor described above. A light emitting element having an emission spectrum of 400 nm is used as an excitation light source. The phosphors are BaSi ₂ O ₂ N ₂ : Eu, (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce, SrCaSi ₅ N ₈ : Eu, (Ca _0.93 , Eu _0.05 , Mn _0.02 ) ₁₀ (PO ₄ ) ₆ Cl ₂ is used. FIG. 1 shows a light emitting device according to the present invention. FIG. 9 is a plan view showing a light emitting device according to the present invention. FIG. 10 is a cross-sectional view showing AA ′ of the light emitting device according to the present invention. FIG. 11 is a diagram showing an emission spectrum (simulation) of the light emitting device of Example 1. FIG. 12 is a diagram illustrating chromaticity coordinates (simulation) of the light-emitting devices of Examples 1 to 3. In the light emitting device of Example 1, the color temperature is adjusted to 4000 to 5000K.

(Light emitting element)
The substrate 201 made of sapphire (C surface) is set in a MOVPE reaction vessel, and the temperature of the substrate 201 is raised to about 1050 ° C. while flowing hydrogen to clean the substrate 201.

In this embodiment, a sapphire substrate is used as the substrate 201. However, a different type substrate different from a nitride semiconductor, or a nitride semiconductor substrate such as AlN, AlGaN, or GaN may be used as the substrate 201. Examples of the dissimilar substrate include sapphire, spinel (insulating substrate such as MgAl ₂ O ₄ ), SiC (including 6H, 4H, 3C), ZnS having one of the C-plane, R-plane, and A-plane as the main surface. It is possible to grow a nitride semiconductor such as an oxide substrate lattice-matched with ZnO, GaAs, Si, and a nitride semiconductor, and a different substrate material from the nitride semiconductor can be used. In addition, the heterogeneous substrate may be off-angled, and in this case, if an off-angle substrate is used, the growth of the underlying layer 202 made of gallium nitride grows with good crystallinity. Furthermore, when a different type substrate is used, after growing a nitride semiconductor serving as the base layer 202 before forming the element structure on the different type substrate, the different type substrate is formed. The element structure may be formed as a single substrate of a nitride semiconductor by removing the substrate by a method such as polishing, or the heterogeneous substrate may be removed after the element structure is formed. Alternatively, a nitride semiconductor substrate may be used.

(Buffer layer)
Subsequently, the temperature of the substrate 201 is lowered to 510 ° C., hydrogen is used as the carrier gas, ammonia and TMG (trimethyl gallium) are used as the source gas, and a buffer layer (not shown) made of GaN is formed on the substrate 201 at about 100 Å. Grow with film thickness.

(Underlayer)
After growing the buffer layer, only TMG is stopped and the temperature of the substrate 201 is raised to 1050 ° C. When the temperature reaches 1050 ° C., TMG and ammonia gas are also used as source gases, and an undoped GaN layer is grown to a thickness of 2 μm.

(N-type layer)
Subsequently, at 1050 ° C., the n-type layer 203 made of GaN doped with 4.5 × 10 ¹⁸ / cm ^{3 of} Si is similarly used as the n-type layer, using TMG as the source gas, ammonia gas, and silane gas as the impurity gas. The n-side contact layer for forming the electrode 211a is grown to a thickness of 3 μm.

(Active layer)
A barrier layer made of Si-doped GaN is grown to a thickness of 50 angstroms, followed by a temperature of 800 ° C., and a well layer made of undoped In _0.1 Ga _0.7 N using TMG, TMI, and ammonia is 50 angstroms. Growing with a film thickness of Then, four layers of barrier layers and three layers of wells are alternately stacked in the order of barrier + well + barrier + well ... + barrier to grow an active layer 204 having a multi-quantum well structure with a total film thickness of 350 angstroms. Let

(P-side carrier confinement layer)
Next, TMG, TMA, ammonia, Cp ₂ Mg (cyclopentadienyl magnesium) is used, and a p-side carrier confinement layer made of Al _0.3 Ga _0.7 N doped with Mg 5 × 10 ¹⁹ / cm ³ 205 is grown with a film thickness of 100 Å.

(First p-type layer)
Subsequently, a first p-type layer 206 made of GaN doped with p-type impurities using TMG, ammonia, and Cp ₂ Mg is grown to a thickness of 0.1 μm.

(Second p-type layer)
As a second p-type layer, a p-side contact layer 208 that forms a p-side electrode 210 on the surface is formed. The p-side contact layer 208 is formed by growing p-type GaN doped with Mg at 1 × 10 ²⁰ / cm ³ on the current diffusion layer 207 to a thickness of 150 Å. Since the p-side contact layer 208 is a layer for forming the p-side electrode 210, it is desirable that the p-side contact layer 208 has a high carrier concentration of 1 × 10 ¹⁷ / cm ³ or more. If it is lower than 1 × 10 ¹⁷ / cm ^3, it tends to be difficult to obtain a preferable ohmic with the electrode. Furthermore, when the composition of the contact layer is GaN, a preferable ohmic with the electrode material is easily obtained.

  After the reaction for forming the element structure is completed, the temperature is lowered to room temperature, and the wafer is annealed in a reaction vessel at 700 ° C. in a nitrogen atmosphere to further reduce the resistance of the p-type layer. The wafer on which the element structure is formed is taken out from the apparatus, and an electrode forming process described below is performed.

  After annealing, the wafer is taken out of the reaction vessel, a predetermined mask is formed on the surface of the uppermost p-side contact layer 208, and etching is performed from the p-side contact layer 208 side with an RIE (reactive ion etching) apparatus, and the n-side An electrode forming surface is formed by exposing the surface of the contact layer.

  As the p-side electrode 210, Ni and Au are sequentially stacked to form the p-side electrode 210 made of Ni / Au. The p-side electrode 210 is an ohmic electrode in ohmic contact with the second p-type layer and the p-side contact layer 208. At this time, in the formed electrode branch 210a, the stripe-shaped light emitting portion 209 has a width of about 5 μm, the stripe-shaped electrode branch 210a has a width of about 3 μm, and the stripe-shaped light emitting portions 209 and the electrode branches 210a are alternately formed. To do. Further, only a part of the p-side electrode 210 is formed in the region where the p-side pad electrode is formed, and is formed over the p-side pad electrode to be electrically connected. At this time, only a part of the p-side electrode 210 is formed in the region where the p-side pad electrode is formed, and the p-side pad electrode 210b is formed on the surface of the p-side contact layer 208, and a part of the p-side electrode 210 is formed. It is formed over the side electrode 210 and is electrically connected. At this time, the surface of the p-side contact layer 208 provided with the p-side pad electrode 210b is not in ohmic contact with the p-side electrode 210 and the p-side contact layer 208, and a Schottky barrier is formed between the two. From the portion where the p-side pad electrode 210b is formed, current does not flow directly into the device, but current is injected into the device through the electrically connected electrode branch 210a.

  Subsequently, the n-side electrode 211a is formed on the exposed surface 203a where the n-type layer 203 is exposed. The n-side electrode 211a is formed by stacking Ti and Al.

  Here, the n-side electrode 211a is an ohmic electrode in ohmic contact with the exposed surface 203a of the n-type layer 203. After the ohmic p-side electrode 210 and the n-side electrode 211a are formed, each electrode is subjected to ohmic contact by annealing through heat treatment. The p-side ohmic electrode obtained at this time becomes an opaque film that hardly transmits the light emitted from the active layer 204.

Subsequently, the entire surface excluding a part or all of the p-side electrode 210 and the n-side electrode 211a, that is, the entire surface of the device such as the exposed surface 203a of the n-type layer 203 and the side surface of the exposed surface 203a _An insulating film made of ₂ is formed. After the formation of the insulating film, bonding pad electrodes are respectively formed on the surfaces of the p-side electrode 210 and the n-side electrode 211a exposed from the insulating film, and are electrically connected to the respective ohmic electrodes. The p-side pad electrode 210b and the n-side pad electrode 211b are formed by stacking Ni, Ti, and Au on each ohmic electrode, respectively.

  Finally, the substrate 201 is divided to obtain a light-emitting element having a side length of 300 μm.

  The obtained light emitting device has an emission peak wavelength of about 400 nm.

(Phosphor)
The light emitting device of Example 1 includes BaSi ₂ O ₂ N ₂ : Eu of Example 1, (Ca _0.93 , Eu _0.05 , Mn _0.02 ) ₁₀ (PO ₄ ) ₆ Cl ₂ , ( Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce and SrCaSi ₅ N ₈ : Eu are used. This blending ratio can be changed as appropriate. These phosphors are irradiated using an excitation light source with Ex = 400 nm. These phosphors absorb light from the excitation light source, perform wavelength conversion, and have a predetermined emission wavelength. BaSi ₂ O ₂ N ₂ in Example 1: Eu has a peak emission wavelength in 470Nm～530nm. (Ca _0.93 , Eu _0.05 , Mn _0.02 ) ₁₀ (PO ₄ ) ₆ Cl ₂ has an emission peak wavelength at 440 to 500 nm. (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce has an emission peak wavelength at 500 to 650 nm. SrCaSi ₅ N ₈ : Eu has an emission peak wavelength at 580 nm to 730 nm.

(Characteristics of light-emitting device of Example 1)
Table 3 shows the characteristics and color rendering properties of the light emitting device of Example 1. However, the characteristics and color rendering properties of the light-emitting device of Example 1 are simulations. When actually manufactured, self-absorption occurs and wavelength shift is considered to occur. As a light emitting device of Comparative Example 1, using an excitation light source with Ex = 400 nm, (Ca _0.93 , Eu _0.05 , Mn _0.02 ) ₁₀ (PO ₄ ) ₆ Cl ₂ and (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce is used.

The phosphor excited by the light emitting element excited by 400 nm is BaSi ₂ O ₂ N ₂ : Eu of Example 1 from blue-green to green-based region (Ca _0.93 , Eu _0.05 , Mn _0.02 ). ₁₀ (PO ₄ ) ₆ Cl ₂ is from blue-violet to blue-based region, (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce is from green to yellow-red region, SrCaSi ₅ N ₈ : Eu is yellow Each has a peak emission wavelength from red to red. Due to the color mixture of the light of these phosphors, an emission color is shown in the white region. From this, the light-emitting device of Example 1 shows luminescent color in a white range. In addition, since an excitation light source near 400 nm having low visibility characteristics is used, the color tone can be easily changed by changing the blending ratio of the phosphors. In particular, in the white light emitting device shown in Comparative Example 1, the average color rendering index (Ra) was 76.0. However, in the white light emitting device according to Example 1, the average color rendering index (Ra) was 88. 1 and very good. The color rendering is improved from this. In addition, the special color rendering index (R1 to R15) has improved color rendering properties in almost all color charts. Further, the white light emitting device shown in Comparative Example 1 has a special color rendering index (R9) of −1.9, whereas the white light emitting device according to Example 1 has a special color rendering index (R9) of It was 96.1 and very good. This special color rendering index (R9) is a red color chart with relatively high saturation. Visibility efficiency is expressed as a relative value when the light emitting device of Comparative Example 1 is taken as 100%.

<Light emitting device>
The light emitting devices of Examples 2 and 3 relate to a white light emitting device using a light emitting element having an emission peak wavelength of 460 nm as an excitation light source. FIG. 1 is a diagram showing a light emitting device according to the present invention. FIG. 13 is a diagram showing an emission spectrum (simulation) of the light emitting devices of Examples 2 and 3.

(Light emitting element)
In the light emitting devices of Examples 2 and 3, an n-type and p-type GaN semiconductor layer 2 is formed on a sapphire substrate 1, and an electrode 3 is provided on the n-type and p-type semiconductor layer 2. 3 is conductively connected to the lead frame 13 by a conductive wire 14. The upper part of the light emitting element 10 is covered with the phosphor 11 and the coating member 12, and the outer periphery of the lead frame 13, the phosphor 11, the coating member 12, and the like is covered with the mold member 15. The semiconductor layer 2 is laminated on the sapphire substrate 1 in the order of n ⁺ GaN: Si, n-AlGaN: Si, n-GaN, GaInN QWs, p-GaN: Mg, p-AlGaN: Mg, p-GaN: Mg. ing. Part of the n ⁺ GaN: Si layer is etched to form an n-type electrode. A p-type electrode is formed on the p-GaN: Mg layer. The lead frame 13 uses iron-containing copper. A cup for mounting the light-emitting element 10 is provided on the upper portion of the mount lead 13a, and the light-emitting element 10 is die-bonded to the bottom surface of the substantially central portion of the cup. Gold is used for the conductive wire 14, and Ni plating is applied to the bump 4 for conductively connecting the electrode 3 and the conductive wire 14. The phosphor 11 is mixed with the phosphor of Example 49 and the YAG phosphor. As the coating member 12, a material obtained by mixing an epoxy resin, a diffusing agent, barium titanate, titanium oxide, and the phosphor 11 at a predetermined ratio is used. The mold member 15 uses an epoxy resin. This bullet-type light emitting device of Example 1 is a cylindrical shape in which the upper part of the mold member 15 having a radius of 2 to 4 mm and a height of about 7 to 10 mm is a hemisphere.

  When a current is passed through the light emitting devices of Examples 2 and 3, the blue light emitting element 10 having a light emission peak wavelength at approximately 460 nm emits light. The phosphor 11 covering the semiconductor layer 2 performs color tone conversion on the blue light. As a result, the light emitting devices of Examples 2 and 3 that emit white light can be provided.

(Phosphor)
The phosphor 11 used in the light emitting devices of Examples 2 and 3 according to the present invention is represented by the oxynitride phosphor of Example 1 and (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce. A phosphor 11 in which a YAG phosphor and a nitride phosphor represented by CaSrSi ₅ N ₈ : Eu are mixed is used. The phosphor 11 is mixed together with the coating member 12. This blending ratio can be changed as appropriate. These phosphors 11 are irradiated using an excitation light source of Ex = 460 nm. These phosphors 11 absorb light from the excitation light source, perform wavelength conversion, and have a predetermined emission wavelength. BaSi ₂ O ₂ N ₂ in Example 1: Eu has a peak emission wavelength in 470Nm～530nm. (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce has an emission peak wavelength at 500 to 650 nm. SrCaSi ₅ N ₈ : Eu has an emission peak wavelength at 580 nm to 730 nm.

  In the light emitting devices of Examples 2 and 3, part of the light from the light emitting element 10 is transmitted. Further, part of the light from the light emitting element 10 excites the phosphor 11 to perform wavelength conversion, and the phosphor 11 has a predetermined emission wavelength. A light emitting device that emits white light can be provided by mixing the blue light from the light emitting element 10 and the light from the phosphor 11.

(Characteristics of light-emitting devices of Examples 2 and 3)
Table 4 shows the characteristics and color rendering properties of the light emitting devices of Examples 2 and 3. However, the characteristics and color rendering properties of the light emitting devices of Examples 2 and 3 are simulations, and when actually manufactured, self-absorption occurs and wavelength shift seems to occur. As a light-emitting device of Comparative Example 2, (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce is used using an excitation light source of Ex = 460 nm. Examples 2 and 3 are emission spectra when the peak values are the same.

The phosphor excited by the light-emitting element excited at 460 nm is BaSi ₂ O ₂ N ₂ : Eu of Example 1 from blue-green to green-based region, and (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce. Has an emission peak wavelength from green to yellow-red region, and SrCaSi ₅ N ₈ : Eu has an emission peak wavelength from yellow-red to red region. Due to the color mixture of the light of these phosphors, an emission color is shown in the white region. Thus, the light-emitting devices of Examples 2 and 3 exhibit a luminescent color in the white range. Further, since visible light in the vicinity of 460 nm is used as the excitation light source and a phosphor that emits blue light is not used, loss of light emission efficiency due to wavelength conversion is small. Furthermore, the color tone can be easily changed by changing the blending ratio of the phosphors. In particular, in the white light emitting device shown in Comparative Example 2, the average color rendering index (Ra) was 76.0. However, in the white light emitting devices according to Examples 2 and 3, the average color rendering index (Ra) was It was very good with 84.5 and 83.1. The color rendering is improved from this. In addition, the special color rendering index (R1 to R15) has improved color rendering properties in almost all color charts. Furthermore, the white light emitting device shown in Comparative Example 2 has a special color rendering index (R9) of −1.9, whereas the white light emitting devices according to Examples 2 and 3 have a special color rendering index (R9). ) Was very good, 70.7 and 94.1. This special color rendering index (R9) is a red color chart with relatively high saturation. Visibility efficiency is expressed as a relative value when the light emitting device of the comparative example is 100%.

<Light emitting device>
The light-emitting device of Example 4 relates to a white light-emitting device using a light-emitting element having an emission peak wavelength of 457 nm as an excitation light source. FIG. 1 is a diagram showing a light emitting device according to the present invention. FIG. 14 is a diagram showing emission spectra of the light emitting devices of Example 4 and Example 5.

(Light emitting element)
When a current is passed through the light emitting device of Example 4, the blue light emitting element 10 having a light emission peak wavelength at approximately 457 nm emits light. The phosphor 11 covering the semiconductor layer 2 performs color tone conversion on the blue light. As a result, the light emitting device of Example 4 that emits white light can be provided.

(Phosphor)
The phosphor 11 used in the light emitting device of Example 4 according to the present invention includes the oxynitride phosphor of Example 1 and YAG fluorescence represented by (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce. And a phosphor 11 in which a nitride phosphor represented by CaSrSi ₅ N ₈ : Eu is mixed is used. The phosphor 11 is mixed together with the coating member 12. This blending ratio can be changed as appropriate. These phosphors 11 are irradiated with an excitation light source of Ex = 457 nm. These phosphors 11 absorb light from the excitation light source, perform wavelength conversion, and have a predetermined emission wavelength. BaSi ₂ O ₂ N ₂ in Example 1: Eu has a peak emission wavelength in 470Nm～530nm. (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce has an emission peak wavelength at 500 to 650 nm. SrCaSi ₅ N ₈ : Eu has an emission peak wavelength at 580 nm to 730 nm.

  In the light emitting device of Example 4, a part of the light of the light emitting element 10 is transmitted. Further, part of the light from the light emitting element 10 excites the phosphor 11 to perform wavelength conversion, and the phosphor 11 has a predetermined emission wavelength. A light emitting device that emits white light can be provided by mixing the blue light from the light emitting element 10 and the light from the phosphor 11.

(Characteristics of Light Emitting Device of Example 4)
Table 5 shows the characteristics and color rendering properties of the light-emitting device of Example 4.

As for the phosphor excited by the light emitting element excited at 457 nm, BaSi ₂ O ₂ N ₂ : Eu of Example 1 changed from blue-green to green-based region, and (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce Has an emission peak wavelength from green to yellow-red region, and SrCaSi ₅ N ₈ : Eu has an emission peak wavelength from yellow-red to red region. Due to the color mixture of the light of these phosphors, an emission color is shown in the white region. From this, the light-emitting device of Example 4 shows luminescent color in a white range. In addition, since visible light in the vicinity of 457 nm is used as the excitation light source and no phosphor that emits blue light is used, there is little loss of light emission efficiency due to wavelength conversion. Furthermore, the color tone can be easily changed by changing the blending ratio of the phosphors. The white light-emitting device of Example 4 exhibits extremely high light emission characteristics with a lamp efficiency of 25.0 lm / W. The white light emitting device according to Example 4 had an average color rendering index (Ra) of 92.7, which was extremely good. The color rendering is improved from this. In addition, the special color rendering index (R1 to R15) has improved color rendering properties in almost all color charts. Furthermore, the white light-emitting device according to Example 4 had an extremely good special color rendering index (R9) of 83.0.

  From the above, the white light-emitting device of Example 4 can provide a light-emitting device having excellent color rendering properties.

<Light emitting device>
The light-emitting device of Example 5 relates to a white light-emitting device using a light-emitting element having an emission peak wavelength of 463 nm as an excitation light source. FIG. 1 is a diagram showing a light emitting device according to the present invention. FIG. 14 is a diagram showing emission spectra of the light emitting devices of Example 4 and Example 5.

(Light emitting element)
When a current is passed through the light emitting device of Example 5, the blue light emitting element 10 having a light emission peak wavelength at approximately 463 nm emits light. The phosphor 11 covering the semiconductor layer 2 performs color tone conversion on the blue light. As a result, the light emitting device of Example 5 that emits white light can be provided.

(Phosphor)
The phosphor 11 used in the light emitting device of Example 5 according to the present invention includes the oxynitride phosphor of Example 1 and the YAG fluorescence represented by (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce. And a phosphor 11 in which a nitride phosphor represented by CaSrSi ₅ N ₈ : Eu is mixed is used. The phosphor 11 is mixed together with the coating member 12. This blending ratio can be changed as appropriate. These phosphors 11 are irradiated with an excitation light source of Ex = 463 nm. These phosphors 11 absorb light from the excitation light source, perform wavelength conversion, and have a predetermined emission wavelength. BaSi ₂ O ₂ N ₂ in Example 1: Eu has a peak emission wavelength in 470Nm～530nm. (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce has an emission peak wavelength at 500 to 650 nm. SrCaSi ₅ N ₈ : Eu has an emission peak wavelength at 580 nm to 730 nm.

  In the light emitting device of Example 5, a part of the light from the light emitting element 10 is transmitted. Further, part of the light from the light emitting element 10 excites the phosphor 11 to perform wavelength conversion, and the phosphor 11 has a predetermined emission wavelength. A light emitting device that emits white light can be provided by mixing the blue light from the light emitting element 10 and the light from the phosphor 11.

(Characteristics of Light Emitting Device of Example 5)
Table 6 shows the characteristics and color rendering properties of the light-emitting device of Example 5.

In the phosphor excited by the light emitting element excited at 463 nm, BaSi ₂ O ₂ N ₂ : Eu in Example 1 changed from blue-green to a green-based region, and (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce Has an emission peak wavelength from green to yellow-red region, and SrCaSi ₅ N ₈ : Eu has an emission peak wavelength from yellow-red to red region. Due to the color mixture of the light of these phosphors, an emission color is shown in the white region. From this, the light-emitting device of Example 5 shows luminescent color in a white range. Further, since visible light in the vicinity of 463 nm is used as the excitation light source and a phosphor that emits blue light is not used, there is little loss of light emission efficiency due to wavelength conversion. Furthermore, the color tone can be easily changed by changing the blending ratio of the phosphors. The white light emitting device of Example 5 has a high light emission characteristic with a lamp efficiency of 21.3 lm / W. The white light emitting device according to Example 5 had an average color rendering index (Ra) of 84.9, which was extremely good. The color rendering is improved from this. In addition, the special color rendering index (R1 to R15) has improved color rendering properties in almost all color charts. Furthermore, the white light-emitting device according to Example 5 had a special color rendering index (R9) of 91.0, which was extremely good.

  From the above, the white light-emitting device of Example 4 can provide a light-emitting device having excellent color rendering properties.

<Light emitting device>
FIG. 15 is a diagram illustrating a cap-type light-emitting device of Example 6.

  In the light-emitting device of Example 6, the same members as those in the light-emitting device of Example 1 are denoted by the same reference numerals, and description thereof is omitted. The light emitting element 10 uses a light emitting element having an emission peak wavelength at 400 nm.

  The light emitting device of Example 6 is configured by covering the surface of the mold member 15 of the light emitting device of Example 1 with a cap 16 made of a light transmissive resin in which a phosphor (not shown) is dispersed.

  A cup for mounting the light emitting element 10 is provided on the top of the mount lead 13a, and the light emitting element 10 is die-bonded to the bottom surface of the substantially central portion of the cup. In the light emitting device of Example 1, the phosphor 11 is provided so as to cover the light emitting element 10 on the upper part of the cup. However, the light emitting device of Example 6 may not be provided. This is because the phosphor 11 is not provided on the light emitting element 10 so that it is not directly affected by the heat generated from the light emitting element 10.

The cap 16 has the phosphor uniformly dispersed in the light transmissive resin. The light-transmitting resin containing this phosphor is molded into a shape that fits into the shape of the mold member 15 of the light-emitting device. Alternatively, a manufacturing method is also possible in which a light-transmitting resin containing a phosphor is placed in a predetermined mold and then the light emitting device is pushed into the mold and molded. Specific materials for the light transmissive resin of the cap 16 include transparent resins, silica sol, glass, inorganic binders, and the like that are excellent in temperature characteristics and weather resistance such as epoxy resins, urea resins, and silicone resins. In addition to the above, thermosetting resins such as melamine resins and phenol resins can be used. In addition, thermoplastic resins such as polyethylene, polypropylene, polyvinyl chloride, and polystyrene, thermoplastic rubbers such as styrene-butadiene block copolymer, segmented polyurethane, and the like can also be used. Further, a diffusing agent, barium titanate, titanium oxide, aluminum oxide or the like may be contained together with the phosphor. Moreover, you may contain a light stabilizer and a coloring agent. The phosphors used for the cap 16 are BaSi ₂ O ₂ N ₂ : Eu oxynitride phosphor, (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce phosphor, and Ba ₂ Si. A nitride phosphor of ₅ N ₈ : Eu and a phosphor of (Ca _0.95 , Eu _0.05 ) ₁₀ (PO ₄ ) ₆ Cl ₂ are used. The phosphor 11 used in the cup of the mount lead 13a is an oxynitride phosphor. However, since the phosphor is used for the cap 16, the oxynitride phosphor may be contained in the cap 16, and only the coating member 12 may be contained in the cup of the mount lead 13a.

  In the light emitting device configured as described above, part of the light emitted from the light emitting element 10 excites the oxynitride phosphor of the phosphor 11 and emits green light. Further, part of the light emitted from the light emitting element 10 or part of the light emitted from the oxynitride phosphor excites the phosphor of the cap 16 and emits light from blue and yellow to red. Thereby, the green light of the oxynitride phosphor and the blue, yellow, and red light of the phosphor of the cap 16 are mixed, and as a result, white light is emitted from the surface of the cap 16 to the outside. .

  The present invention is used for light-emitting devices such as general lighting such as fluorescent lamps, in-vehicle lighting, liquid crystal backlights, and displays.

It is a figure which shows the bullet-type light-emitting device based on this invention. (A) It is a top view which shows the surface mount type light-emitting device based on this invention. (B) It is sectional drawing of the surface mount type light-emitting device based on this invention. It is process drawing which shows the manufacturing method of an oxynitride fluorescent substance. It is a figure which shows the emission spectrum when the oxynitride fluorescent substance of Example 1 thru | or 5 is excited by Ex = 400nm. It is a figure which shows the emission spectrum when the oxynitride fluorescent substance of Example 1 thru | or 5 is excited by Ex = 460nm. It is a figure which shows the excitation spectrum of the oxynitride fluorescent substance of Examples 1 thru | or 5. It is a figure which shows the reflection spectrum of the oxynitride fluorescent substance of Examples 1-5. 2 is an SEM photograph obtained by photographing the oxynitride phosphor of Example 1. It is a top view which shows the light emitting element which concerns on this invention. It is sectional drawing which shows A-A 'of the light emitting element which concerns on this invention. 6 is a diagram showing an emission spectrum (simulation) of the light emitting device of Example 1. FIG. It is a figure which shows the chromaticity coordinate (simulation) of the light-emitting device of Example 1 thru | or 3. It is a figure which shows the emission spectrum (simulation) of the light-emitting device of Example 2 and 3. FIG. It is a figure which shows the emission spectrum of the light-emitting device of Example 4 and Example 5. FIG. 6 is a diagram showing a cap-type light emitting device of Example 6. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Semiconductor layer 3 Electrode 4 Bump 10 Light emitting element 11 Phosphor 12 Coating member 13 Lead frame 13a Mount lead 13b Inner lead 14 Conductive wire 15 Mold member 101 Light emitting element 102 Lead electrode 103 Insulating sealing material 104 Conductive wire 105 Package 106 Lid 107 Window 108 Phosphor 109 Coating member 201 Substrate 202 Underlayer 203 N-type layer 203a Exposed surface 204 Active layer 205 P-side carrier confinement layer 206 First p-type layer 207 Current diffusion layer 208 P-side contact layer 209 Light emission Part 210 p-side electrode 210a electrode branch 210b p-side pad electrode 211a n-side electrode 211b n-side pad electrode

Claims (5)

An excitation light source having an emission wavelength in the short wavelength region from ultraviolet to visible light;
A light-emitting device that absorbs at least part of light from the excitation light source, performs wavelength conversion, and a phosphor having an emission color different from the emission color of the excitation light source,
The phosphor has the general formula _{Ba X Si Y O Z N (} (2/3) X + (4/3) Y- (2/3) Z): Eu
(0.5 <X <1.5 , 1.5 <Y <2.5 , 1.5 <Z <2.5), and Eu is a molar ratio with respect to Ba. The Ba: the Eu = 1: 0.005 to 1: 0.20 oxynitride phosphor,
A rare earth aluminate phosphor mainly activated with a lanthanoid element,
M ₂ Si ₅ N ₈ : Eu (M is at least one selected from Sr, Ca, Ba, Mg, Zn), and
An average color rendering index (Ra) of 80 or more. The light emitting device according to claim 1, wherein the excitation light source is a light emitting element. The phosphor includes the oxynitride phosphor , a rare earth aluminate phosphor mainly activated by a lanthanoid element, and M ₂ Si ₅ N ₈ : Eu (M is Sr, Ca, Ba, Mg, At least one selected from Zn.) And a second phosphor.
The second phosphor converts at least a part of light from the excitation light source and light from the oxynitride phosphor, and has an emission peak wavelength in a visible light region. The light-emitting device according to claim 1 or 2 . The light emitting device according to claim 3 , wherein the second phosphor has at least one emission peak wavelength from a blue region to a green, yellow, and red region. The second phosphor has the general formula M ₅ (PO ₄ ) ₃ X: R (M is at least one selected from Sr, Ca, Ba, Mg, Zn. X is F, Cl, And at least one selected from Br and I. R is Eu, Mn, or any one of Eu and Mn.) And an alkaline earth halogen apatite phosphor represented by The light emitting device according to claim 4 .

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