JP5523676B2 - Phosphor and light emitting device using the same - Google Patents

Description

  The present invention relates to a phosphor and a light emitting device using the same, and more particularly to an oxynitride phosphor containing oxygen and nitrogen and emitting green light and a light emitting device using the same.

  Light emission that can emit light of various wavelengths by the principle of color mixing of light by combining the light source light emitted from the light emitting element and the wavelength conversion member that can be excited by this and emit light of a hue different from the light source light Equipment has been developed. For example, when primary light from a short wavelength region corresponding to visible light is emitted from ultraviolet light from a light emitting element, and the red, blue, and green light emitting phosphors are excited by the wavelength conversion member by the emitted light, the light 3 The primary colors of red, blue and green are additively mixed to obtain white light. In particular, green phosphors have a high contribution to white color because of their large contribution to white, and various phosphors have been studied so far.

An LED-based lighting unit that emits white light, wherein the LED emits primary UV radiation or blue light is disclosed. The illumination unit includes a phosphor that emits green light. The phosphor is subjected to partial conversion of primary radiation, and mixed light is obtained from the illumination unit. In this lighting unit, Eu-activated calcium-magnesium-chlorosilicate (Ca ₈ Mg (SiO ₄ ) ₄ Cl ₂ ) is used as a green-emitting phosphor (for example, Patent Document 1 and Patent Document 1). 2).

  Moreover, the phosphor of the oxynitride glass represented by Ca-Al-Si-ON: Eu is also known (for example, refer patent document 3 and patent document 4). Since these oxynitride glasses are amorphous having no crystallinity, they are difficult to handle and have low luminance. These phosphors have an emission peak at 580 to 700 nm.

Furthermore, an oxynitride phosphor represented by MSi ₂ O ₂ N ₂ : Eu (M is Ca, Sr, Ba) is also known (see, for example, Patent Document 5).

  In particular, when a light emitting element in the short wavelength region from near ultraviolet to visible light is used as the excitation light source, the primary light from the light emitting element itself is in a wavelength range where the visibility is low, so the color mixture of the emitted light as the entire light emitting device Does not contribute much to the ingredients. That is, even if a slight deviation occurs in the emission spectrum of the element due to manufacturing variations, the primary light has an advantage that it hardly affects the color of the emitted light of the light emitting device. That is, the colors of the plurality of light emitting devices can be made substantially uniform. This is an advantage that can be particularly enjoyed in a device configuration in which a large number of light emitting devices are arranged and used. This is because the hues of the light emitting devices constituting the point light source can be made substantially uniform, so that the color unevenness of the entire light in the final device configuration can be reduced. Therefore, there is a demand for a phosphor that is excited by wavelength light in the short wavelength region from near ultraviolet to visible light and has excellent emission characteristics.

  On the other hand, the above light emitting device is used as a light source for backlights such as a liquid crystal display (LCD), a color cathode ray tube (CRT), a projection tube (PRT), a field emission display (FED), and a fluorescent display tube (VFD), When a color filter is combined, the transmission wavelength of the light emitted from the light emitting device is selected depending on the characteristics of the color filter. That is, it is preferable from the viewpoint of efficiency in transmitted light that the peak wavelength in the emitted light on the light emitting device side and the wavelength on which the transmission on the filter side is permitted to coincide with each other.

However, the characteristics desired for the filter vary depending on the final use form of the device, that is, the transmission wavelength range to be dealt with varies. Therefore, the wavelength of the component light constituting the light emitted from the light emitting device has various requirements depending on the change of the filter, and phosphors capable of emitting light in a wavelength region that satisfies this demand are actively developed.
Special Table 2003-535477 Special table 2003-535478 gazette JP 2001-214162 A JP 2002-76434 A International Publication WO2004-030109 Pamphlet

  Under such circumstances, the present inventors have found a new phosphor as a result of intensive studies. That is, a main object of the present invention is to provide a phosphor having a specific peak wavelength and a light emitting device using the phosphor capable of emitting a green component capable of forming white light with reduced color unevenness among a plurality of light emitting devices. There is.

The present invention is a phosphor containing at least silicon, oxygen and nitrogen, activated by europium, capable of absorbing ultraviolet light or blue light and emitting green light, and has a general formula of Ba ₂ Si ₂ O ₃ N ₂ : relates to a phosphor represented by Eu .

The phosphor according to the embodiment is a phosphor that contains at least silicon, oxygen, and nitrogen, is activated by europium, can absorb ultraviolet light or blue light, and can emit green light. _{L x Si y O a N (} 2/3) x + (4/3) y- (2/3) a: shown by Eu, L represents at least one element selected from the group consisting of Mg, Ca, Sr, Ba, And x, y, and a relate to a phosphor that satisfies 1.5 ≦ x ≦ 2.5, 3.3 ≦ y ≦ 4.5, and 6.6 ≦ a ≦ 10.

The phosphor according to the embodiment is a phosphor that contains at least silicon, oxygen, and nitrogen, is activated by europium, can absorb ultraviolet light or blue light, and can emit green light. L _x Si _y M _z O _a N _b : Eu, L is at least one selected from the group consisting of Mg, Ca, Sr and Ba, and M is a group consisting of B, Al, Ga and In X, y, z, a, and b are 1.5 ≦ x ≦ 2.5, 0.5 ≦ y <1.5, 0 <z ≦ 2.5, and 2. The present invention relates to a phosphor that satisfies 0 ≦ a ≦ 6.0 and b = (2/3) x + (4/3) y + z− (2/3) a.

  L preferably includes at least Ba. Thereby, a high-luminance green-emitting phosphor can be provided.

The phosphor preferably has a general formula represented by Ba ₂ Si ₂ O ₃ N ₂ : Eu. Thereby, when excited with light of around 400 nm, light can be emitted with high brightness.

As the phosphor according to the embodiment, a phosphor represented by the general formula Ba ₂ Si ₄ O _8.2 N _1.2 : Eu is preferable. Thereby, when excited with light near 460 nm, light can be emitted with high brightness.

The phosphor according to the embodiment preferably has a general formula represented by Ba ₂ SiAl ₂ O ₄ N ₂ : Eu. As a result, when excited with light near 400 nm or 460 nm, light can be emitted with high brightness.

The present invention includes an excitation light source that emits excitation light, absorbs a part of light from the excitation light source, a light emitting device comprising said phosphor emitting fluorescent light.

  The phosphor of the present invention is a green light-emitting phosphor mainly containing alkaline earth metal, silicon, oxygen, and nitrogen. By specifying the element composition ratio within a predetermined range, the phosphor emits light. The light emission characteristics such as the amount of light flux transmitted through the filter and the luminance can be improved by substantially matching the wavelength and the characteristics of the filter that can be combined therewith.

  In addition, the phosphor of the present invention is excited from near-ultraviolet light having low visibility to wavelength light in the short wavelength region of visible light. Therefore, in the light emitting device of the present invention composed of the excitation light source in the above wavelength range and the phosphor, the contribution of the excitation light source is greatly reduced in the hue of the entire mixed color light, and is affected by the wavelength shift of the excitation light source. Can be a difficult structure. That is, it is possible to emit a green component capable of forming white light with reduced color unevenness between a plurality of light emitting devices. As a result, the colors of the plurality of light emitting devices can be substantially unified, leading to an improvement in yield.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiment described below exemplifies a phosphor and a light emitting device using the phosphor for embodying the technical idea of the present invention, and the present invention uses the phosphor and the same. The light emitting device is not specified as follows. In addition, the member shown by the claim is not what specifies the member of embodiment. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the constituent members described in the embodiments are not intended to limit the scope of the present invention only to the description unless otherwise specified. It is just an example. Note that the size, positional relationship, and the like of the members shown in each drawing may be exaggerated for clarity of explanation. Furthermore, in the following description, the same name and symbol indicate the same or the same members, and detailed description thereof will be omitted as appropriate. Furthermore, each element constituting the present invention may be configured such that a plurality of elements are constituted by the same member and the plurality of elements are shared by one member, and conversely, the function of one member is constituted by a plurality of members. It can also be realized by sharing. In addition, the contents described in some examples and embodiments may be used in other examples and embodiments.

(Embodiment 1)
The phosphor according to Embodiment 1 is an oxynitride phosphor containing at least oxygen, nitrogen, and silicon, and has europium as the emission center. This phosphor absorbs wavelengths in the near-ultraviolet or visible light short wavelength region and emits green light, and specifically has a light emission peak in a wavelength range of 495 nm to 540 nm.

The general formulas (I), (II), and (III) of the phosphor according to Embodiment 1 are shown.
L _x Si _y O _a N _{((2/3) x + (4/3) y- (2/3) a)} : Eu (I)
In the phosphor (I), L is a Group II element that is at least one selected from the group consisting of Mg, Ca, Sr, and Ba. O is an oxygen element, N is a nitrogen element, and Eu is a europium element. Further, 1.5 ≦ x ≦ 2.5, 1.5 ≦ y ≦ 2.5, and 1.5 ≦ a ≦ 4.5 are satisfied.
L _x Si _y O _a N _{((2/3) x + (4/3) y- (2/3) a)} : Eu (II)
In the phosphor (II), L is a Group II element that is at least one selected from the group consisting of Mg, Ca, Sr, and Ba. O is an oxygen element, N is a nitrogen element, and Eu is a europium element. Further, 1.5 ≦ x ≦ 2.5, 3.3 ≦ y ≦ 4.5, and 6.6 ≦ a ≦ 10 are satisfied.
L _x Si _y M _z O _a N _b : Eu (III)
In the phosphor of the general formula (III), L is a Group II element that is at least one selected from the group consisting of Mg, Ca, Sr, and Ba. Si is a silicon element. M is a Group III element that is at least one selected from the group consisting of B, Al, Ga, and In. O is an oxygen element, N is a nitrogen element, and Eu is a europium element. Also, 1.5 ≦ x ≦ 2.5, 0.5 ≦ y <1.5, 0 <z ≦ 2.5, 2.0 ≦ a ≦ 6.0, b = (2/3) x + (4 / 3) y + z- (2/3) a is satisfied.

By specifying x, y, z, a, and b in the above ranges in the composition ratios of the phosphors of the general formulas (I), (II), and (III), a phosphor exhibiting high luminance is obtained. Specific phosphors of the general formula (I) satisfying this range include Ba ₂ Si ₂ O ₃ N ₂ : Eu and Ba ₂ Si ₂ O ₄ N _(4/3) : Eu. Further, the phosphor of the general formula (II) can be configured with a composition ratio of Ba ₂ Si ₄ O _8.2 N _1.2 : Eu. Further, the phosphor of the general formula (III) can be configured with a composition ratio of Ba ₂ SiAl ₂ O ₄ N ₂ : Eu. In particular, higher brightness is exhibited by adjusting the composition to substantially satisfy Ba ₂ SiAl ₂ O ₄ N ₂ : Eu. However, the composition ratio of the phosphor is not particularly limited as long as it satisfies the above range, and the individual values of x, y, z, a, and b are not limited thereto. Further, the oxynitride phosphor of the first embodiment can adjust the color tone and luminance by changing the elemental composition ratio of O and N. Furthermore, the emission spectrum and intensity can be finely adjusted by changing the molar ratio of the cation to the anion in (L + Si + M) / (O + N). Although this adjustment method is not particularly limited, it can be achieved, for example, by performing a treatment such as a vacuum and desorbing N and O. Therefore, the peak wavelength can be intentionally displaced by adjusting the composition ratio. Further, the composition of the oxynitride phosphor may contain at least one element selected from the group consisting of Li, Na, K, Rb, Cs, Mn, Re, Cu, Ag, and Au. Good. Further, other elements may be mixed to such an extent that the characteristics of the phosphor are not impaired.

  Further, as described above, L, which is a composition element of the phosphor, is a Group II element that is at least one selected from the group consisting of Mg, Ca, Sr, and Ba. Ba is preferable, and a part of Ba may be substituted with Mg, Ca, or Sr. That is, as the element L, a single group II element or two or more kinds of elements can be adopted, and these elements can be combined in various combinations with a desired blending ratio. Specifically, in addition to simple substances such as Ca, Ba and Sr, the combination of Ca and Sr, Ca and Ba, Sr and Ba, Ca and Mg, etc. can be changed in various ways, thereby adjusting the peak wavelength of the phosphor appropriately it can.

  Similarly, M, which is a composition element of the phosphor, is a Group III element that is at least one selected from the group consisting of B, Al, Ga, and In. Al is preferable, and a part of this Al may be substituted with another group III element. That is, similarly to the element L, the element M can be a group III element alone or two or more elements, and by combining a plurality of elements with a desired blending ratio, the peak wavelength displacement in the phosphor can be reduced. Can be controlled.

  Further, in the phosphor in the first embodiment, Eu, which is a rare earth, becomes the emission center. However, the present invention is not limited to Eu, and a part thereof can be replaced with another rare earth metal or alkaline earth metal to be co-activated with Eu.

  In addition, the phosphor may contain various additive elements as flux and, if necessary, boron. Thereby, it becomes possible to promote solid-phase reaction and form particles of uniform size.

  The phosphor according to the embodiment of the present invention can absorb near ultraviolet light or blue light and emit green light. In this specification, blue light from the near ultraviolet region refers to a region of 250 to 470 nm, although not particularly limited. In particular, the range of 290 nm to 460 nm is preferable. In this specification, “green light” is a range including not only those having an emission peak wavelength in the range of 495 nm to 548 nm but also those having an emission peak wavelength in the blue green of 485 nm to 495 nm.

  Moreover, it is preferable that most of the phosphors have crystals. For example, since the glass body (amorphous) has a loose structure, there is a possibility that the component ratio in the phosphor is not constant and chromaticity unevenness occurs. Therefore, in order to avoid this, it is necessary to control the reaction conditions in the production process to be strictly uniform. On the other hand, since the phosphor according to the first embodiment can be a powder or a particle having a crystal instead of a glass body, it is easy to manufacture and process. Further, this phosphor can be uniformly dissolved in an organic medium, and adjustment of a light emitting plastic or a polymer thin film material can be easily achieved. Specifically, in the phosphor according to Embodiment 1, at least 50 wt% or more, more preferably 80 wt% or more has crystals. This indicates the proportion of the crystalline phase having luminescent properties, and if it has a crystalline phase of 50% by weight or more, light emission that can withstand practical use can be obtained. Therefore, the more crystal phases, the better. Thereby, the light emission luminance can be increased and the workability is improved.

(Particle size)
In consideration of mounting in a light emitting device, the particle size of the phosphor is preferably in the range of 1 μm to 30 μm, more preferably 2 μm to 20 μm. Moreover, it is preferable that the phosphor having this average particle diameter value is contained frequently. Furthermore, the particle size distribution is preferably distributed in a narrow range. By using a phosphor having a large particle size and having small particle size and particle size distribution variations and optically excellent characteristics, color unevenness is further suppressed and a light emitting device having a good color tone can be obtained. Therefore, a phosphor having a particle size in the above range has high light absorption and conversion efficiency. On the other hand, a phosphor having a particle size smaller than 2 μm tends to form an aggregate.

The particle size is F.D. S. S. S. The average particle diameter obtained by the air permeation method in No (Fisher Sub Sieve Sizer's No). Specifically, in an environment with an air temperature of 25 ° C. and a humidity of 70%, a sample of 1 cm ³ is weighed, packed in a special tubular container, and then dried with a constant pressure, and the specific surface area is read from the differential pressure and averaged. It is a value converted into a particle size.

(Production method)
Below, the manufacturing method of the fluorescent substance concerning Embodiment 1 is explained. The phosphor of the first embodiment is prepared by using, as a raw material, elemental elements, oxides, carbonates, nitrides, or the like contained in the composition thereof, and weighing each raw material to have a predetermined composition ratio.

Regarding a specific phosphor material, Si of the phosphor composition is preferably an oxide or a nitride compound, but an imide compound or an amide compound can also be used. For _{example, SiO 2, Si 3 N 4} , Si (NH 2) 2, etc. Mg ₂ Si and the like. On the other hand, it is possible to obtain a phosphor with good crystallinity at low cost by using only Si. The purity of the raw material Si is preferably 2N or higher, but may contain different elements such as Li, Na, K, B, and Cu. Furthermore, a part of Si can be replaced with Al, Ga, In, Tl, Ge, Sn, Ti, Zr, and Hf.

  Further, the alkaline earth metals Mg, Ca, Sr, and Ba constituting the element L of the phosphor composition are preferably used alone, but metal, oxide, imide, amide, nitride, carbonate, phosphorus Compounds such as various salts such as acid salts and silicates can be used.

In addition, group III elements B, Al, Ga, and In, which are elements M of the phosphor composition, are used alone, and similarly to element L, compounds such as metals, oxides, imides, amides, nitrides, and various salts are used. be able to. Examples include 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. Moreover, you may use what mixed the element of L, Si, and M of a main component previously.

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

Further, Eu as the activator is preferably used alone, but halogen salts, oxides, carbonates, phosphates, silicates and the like can be used. Further, a part of Eu may be replaced by Sc, Y, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, or the like. Moreover, when using the mixture which requires Eu, a compounding ratio can be changed as desired. Thus, by replacing a part of Eu with another element, the other element acts as a co-activation. As a result, the color tone can be changed, and the light emission characteristics can be adjusted. Europium mainly has bivalent and trivalent energy levels, but the phosphor of Embodiment 1 uses Eu ²⁺ as an activator.

Further, a Eu compound may be used as a raw material. In this case, it is better to use a purified raw material, but a commercially available product may be used. Specifically, europium oxide Eu ₂ O ₃ , metal europium, europium nitride, and the like can be used as Eu compounds. The raw material Eu may be an imide compound or an amide compound. Europium oxide preferably has a high purity, and commercially available products can also be used.

  Furthermore, elements to be added as necessary are usually added as oxides or hydroxides, but are not limited thereto, and may be metals, nitrides, imides, amides, or other inorganic salts, , It may be contained in other raw materials in advance. Each raw material has an average particle size of about 0.1 μm or more and 15 μm or less, more preferably about 0.1 μm to 10 μm. It is preferable from the viewpoint of diameter control and the like, and when the particle diameter is not less than the above range, it can be achieved by pulverizing in a glove box in an argon atmosphere or a nitrogen atmosphere.

  The raw material is preferably purified. This is because no purification process is required, and the phosphor manufacturing process can be simplified and an inexpensive phosphor can be provided.

  Among the raw materials described above, a predetermined amount of L nitride, Si nitride or Si oxide, M nitride or M oxide as a base material, and Eu oxide as an activator are measured. That is, these raw materials are weighed and mixed until they are uniform so that the composition ratios of the general formulas (I), (II), and (III) are obtained. Alternatively, an additive material such as a flux is appropriately added to these raw materials, and mixed by a wet or dry method using a mixer.

  The mixer can be pulverized using a pulverizer such as a vibration mill, a roll mill, a jet mill, or the like, in addition to a ball mill that is usually used industrially, to increase the specific surface area. Moreover, in order to keep the specific surface area of the powder within a certain range, classification is performed using a wet type separator such as a sedimentation tank, a hydrocyclone, and a centrifugal separator, and a dry classifier such as a cyclone and an air separator. You can also

The mixed raw materials are packed in a crucible made of a material such as SiC, quartz, alumina (Al ₂ O ₃ ), boron nitride (BN), and fired in a reducing atmosphere such as a nitrogen atmosphere or a nitrogen-hydrogen atmosphere. Other firing atmospheres may be an inert gas atmosphere such as an argon atmosphere or an ammonia atmosphere. 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 is preferably 1000 ° C. to 1600 ° C., and is performed for about 1 hour to 20 hours.

  The fired product is pulverized, dispersed, filtered, etc. to obtain the desired phosphor powder. Solid-liquid separation can be performed by industrially used methods such as filtration, suction filtration, pressure filtration, centrifugation, and decantation. Drying can be achieved by industrially used apparatuses and methods such as a vacuum dryer, a hot air heating dryer, a conical dryer, and a rotary evaporator.

  As an example of the phosphor of the first embodiment, an example of a method for producing each of the oxynitride phosphors of the general formulas (I), (II), and (III) will be described below. Moreover, the fluorescent substance which changed the composition ratio variously was mentioned as an Example. However, the following examples illustrate phosphors for embodying the technical idea of the present invention and their manufacturing methods, and the present invention does not specify the phosphors and their manufacturing methods as follows. .

(Examples 1 to 13)
The phosphors of Examples 1 to 13 are phosphors of the above general formula (I), and L _x Si _y O _a N _{((2/3) x + (4/3) y- (2/3) a)} : Represented by Eu and composed of a composition ratio satisfying 1.5 ≦ x ≦ 2.5, 1.5 ≦ y ≦ 2.5, and 1.5 ≦ a ≦ 4.5.

  FIG. 1 shows excitation spectra of the phosphors according to Examples 1 to 5 and Comparative Example 1. In FIG. 1, the excitation spectra of Examples 1 to 3 are close to each other, and the excitation spectra of Examples 1 to 3 are shown in FIGS. FIG. 5 shows the reflection spectra of the phosphors according to Examples 1 to 5. Similarly, the excitation spectra of Examples 1 to 5 are shown in FIGS. FIG. 11 shows emission spectra when the phosphors according to Examples 1 to 5 and Comparative Example 1 are excited at 400 nm, and the spectra of Examples 1, 2, and 5 are shown in FIGS. 12 to 14, respectively. FIG. 15 shows emission spectra when the phosphors according to Examples 1 to 5 and Comparative Example 1 are excited at 460 nm. FIG. 16 shows a 5000 × magnified photograph of the phosphor according to Example 3.

As an example, the Ba ₂ Si ₂ O ₃ N ₂ : Eu oxynitride phosphor according to Example 3 is manufactured as follows. Specifically, powders of barium carbonate (BaCO ₃ ), silicon nitride (Si ₃ N ₄ ), silicon dioxide (SiO ₂ ), and europium oxide (Eu ₂ O ₃ ) are used as raw materials, and their mixing ratio (molar ratio) is Each raw material was weighed so that BaCO ₃ : Si ₃ N ₄ : SiO ₂ : Eu ₂ O ₃ = 1.95: 0.5: 0.5: 0.025. Specifically, the phosphor material of Example 3 was weighed to the mass shown below. However, the purity of each phosphor material is assumed to be 100%.
BaCO ₃ ... 38.05g
Si ₃ N ₄ ... 7.12 g
SiO ₂ ···· 3.05g
Eu ₂ O ₃ ... 1.79 g

  The weighed raw materials are thoroughly mixed in a dry manner by a ball mill, and the mixture is put into a crucible and fired. Firing was performed in a nitrogen / hydrogen reducing atmosphere at 1400 ° C. for 5 hours. Thereby, the concentration of Eu as an activator is about 5%, the molar ratio of barium to silicon is substantially 1: 1, and the molar ratio of nitrogen to oxygen is substantially 1: 1.5. A phosphor having the above was obtained. Chemical formula 1 shows an example of the reaction formula in the production of the phosphor of Example 3.

  However, the above chemical formula is a representative composition estimated from the blending ratio, and in the actual product, part of the elements may be removed and the composition ratio may change somewhat. Therefore, it has sufficient characteristics to withstand practical use in the vicinity of the composition ratio. Moreover, the composition of the target phosphor can be changed by changing the blending ratio of each raw material.

  Table 1 shows the light emission characteristics when the phosphors of Examples 1 to 5 and Comparative Example 1 were excited at 400 nm. Table 2 shows the light emission characteristics when the phosphors of Examples 1 to 5 and Comparative Example 1 were excited at 460 nm. In Examples 1, 2, 4, and 5, the same raw materials as those in Example 3 were weighed so that the molar ratio of oxygen and nitrogen shown in the table was obtained, and the above production method was used.

As Comparative Example 1, BaSi ₂ O ₂ N ₂ : Eu is used. The phosphors of the above general formulas (I), (II) and (III) have a composition different from that of the phosphor of Comparative Example 1. Further, the phosphors of Examples 1 to 5 have higher emission luminance when excited at 400 nm than the phosphor of Comparative Example 1.

  In Examples 3 and 6 to 13, the Eu concentration of the activator contained in the phosphor was changed. Table 3 shows the light emission characteristics when the phosphors of Examples 3 and 6 to 13 were excited at 400 nm. Table 4 shows the emission characteristics when the phosphors of Examples 3 and 6 to 13 were excited at 460 nm. Specifically, Examples 3 and 6 to 13 have the same composition ratio, and the molar ratio of nitrogen and oxygen is 1: 1.5. In Example 3, the Eu concentration was set to 5%, and this was used as a reference. In the phosphors of Examples 6 to 13, the Eu concentration was increased by 2% from the reference.

(Examples 14 to 26)
The phosphors of Examples 14 to 26 are phosphors of the above general formula (II), and L _x Si _y O _a N _{((2/3) x + (4/3) y- (2/3) a)} : Represented by Eu and composed of a composition ratio satisfying 1.5 ≦ x ≦ 2.5, 3.3 ≦ y ≦ 4.5, and 6.6 ≦ a ≦ 10.

  FIG. 17 shows excitation spectra of the phosphors according to Examples 14 to 18. FIG. 18 shows the reflection spectra of the phosphors according to Examples 14 to 18. FIG. 19 shows an emission spectrum when the phosphors according to Examples 14 to 18 are excited at 400 nm. FIG. 20 shows an emission spectrum when the phosphors according to Examples 14 to 18 are excited at 460 nm.

As an example, the Ba ₂ Si ₄ O _8.2 N _1.2 : Eu oxynitride phosphor according to Example 16 is manufactured as follows. Powders of barium carbonate (BaCO ₃ ), silicon nitride (Si ₃ N ₄ ), silicon dioxide (SiO ₂ ), and europium oxide (Eu ₂ O ₃ ) are used as raw materials, and their mixing ratio (molar ratio) is BaCO ₃ : Si. Each raw material was weighed so that ₃ N ₄ : SiO ₂ : Eu ₂ O ₃ = 1.86: 0.3: 3.1: 0.07. Specifically, the phosphor materials of Example 16 were weighed to the following mass. However, the purity of each phosphor material is assumed to be 100%.
BaCO ₃ ... 29.60g
Si ₃ N ₄ ··· 3.39g
SiO ₂ ... 15.02g
Eu ₂ O ₃ ... 1.99 g

  By subjecting the weighed raw materials to the same production method as in Example 16, the molar ratio of barium to silicon is substantially 1: 2, and the molar ratio of nitrogen to oxygen is substantially 1.2: 8.2. A phosphor having the following composition was obtained. Chemical formula 2 shows an example of the reaction formula in the production of the phosphor of Example 16.

  However, the above chemical formula is a representative composition estimated from the blending ratio, and in the actual product, part of the elements may be removed and the composition ratio may change somewhat. Therefore, it has sufficient characteristics to withstand practical use in the vicinity of the composition ratio. Moreover, the composition of the target phosphor can be changed by changing the blending ratio of each raw material.

  Table 5 shows the light emission characteristics when the phosphors of Examples 14 to 18 were excited at 400 nm. Table 6 shows the light emission characteristics when the phosphors of Examples 14 to 18 were excited at 460 nm. In Examples 14 to 18, the same raw materials as those in Example 3 were weighed so that the molar ratio of oxygen to nitrogen shown in the table was obtained, and the above production method was used.

  In Examples 16 and 19 to 21, the alkaline earth metal element, which is a composition element of the phosphor, was replaced with another alkaline earth metal element. Table 7 shows the light emission characteristics when the phosphors of Examples 16 and 19 to 21 were excited at 400 nm. Table 8 shows the light emission characteristics when the phosphors of Examples 16 and 19 to 21 were excited at 460 nm. Specifically, the Eu concentration as the activator is set to 7%, and the molar ratio of Ba and Sr (Ba / Sr) or Ba and Ca (Ba / Ca) is set to a predetermined ratio based on the phosphor of Example 16. Then, a part of Ba was replaced with Sr or Ca.

  In Examples 22 to 26, the molar ratio of Ba and Si was kept constant, and the molar ratio of oxygen and nitrogen was changed. Table 9 shows the light emission characteristics when the phosphors of Examples 22 to 26 were excited at 400 nm. Table 10 shows the light emission characteristics when the phosphors of Examples 22 to 26 were excited at 460 nm. Specifically, the molar ratio of Ba and Si is substantially fixed at 2: 3.3, and the molar ratio of oxygen and nitrogen is blended so as to be a predetermined composition ratio.

(Examples 27 to 39)
The phosphors of Examples 27 to 39 are phosphors of the above general formula (III), represented by L _x Si _y M _z O _a N _b : Eu, and 1.5 ≦ x ≦ 2.5, 0. 5 ≦ y <1.5, 0 <z ≦ 2.5, 2.0 ≦ a ≦ 6.0, b = (2/3) x + (4/3) y + z− (2/3) a Composed of ratios.

  FIG. 21 shows excitation spectra of the phosphors according to Examples 27 to 31. In FIG. 21, the spectra of Examples 27 to 30 are close to each other, and the spectra of Examples 27 to 30 are shown in FIGS. FIG. 26 shows the reflection spectra of the phosphors according to Examples 27 to 31. FIG. 27 shows an emission spectrum when the phosphors according to Examples 27 to 31 are excited at 400 nm. Furthermore, FIG. 28 shows an emission spectrum when the phosphors according to Examples 27 to 31 are excited at 460 nm. FIG. 29 shows a 5000 × magnified photograph of the phosphor according to Example 29.

As an example, the Ba ₂ SiAl ₂ O ₄ N ₂ : Eu oxynitride phosphor according to Example 29 is manufactured as follows. Powders of barium carbonate (BaCO ₃ ), silicon nitride (Si ₃ N ₄ ), silicon dioxide (SiO ₂ ), aluminum nitride (AlN), and europium oxide (Eu ₂ O ₃ ) are used as raw materials, and their mixing ratio (molar ratio) ) Was weighed so that BaCO ₃ : SiO ₂ : AlN: Eu ₂ O ₃ = 1.95: 1: 2: 0.025. Specifically, the phosphor material of Example 29 was weighed to the following mass. However, the purity of each phosphor material is assumed to be 100%.
BaCO ₃ ··· 7.01 g
SiO ₂ ... 1.12 g
AlN ... 1.53g
Eu ₂ O ₃ ... 0.33 g

  The weighed raw materials are thoroughly mixed in a dry manner by a ball mill, and the mixture is put into a crucible and fired. Firing was performed in a nitrogen / hydrogen reducing atmosphere at 1300 ° C. for 5 hours. Thereby, the concentration of Eu as an activator is about 5%, the molar ratio of barium, silicon and aluminum is substantially 2: 1: 2, and the molar ratio of nitrogen and oxygen is substantially 1: 2. A phosphor having the composition was obtained. Chemical formula 3 shows an example of the reaction formula in the production of the phosphor of Example 29.

  However, the above chemical formula is a representative composition estimated from the blending ratio, and in the actual product, part of the elements may be removed and the composition ratio may change somewhat. Therefore, it has sufficient characteristics to withstand practical use in the vicinity of the composition ratio. Moreover, the composition of the target phosphor can be changed by changing the blending ratio of each raw material.

  Table 11 shows the light emission characteristics when the phosphors of Examples 27 to 31 were excited at 400 nm. Table 12 shows the light emission characteristics when the phosphors of Examples 27 to 31 were excited at 460 nm. In Examples 27, 28, 30, and 31, the same raw materials as those in Example 29 were weighed so that the molar ratios of oxygen and nitrogen shown in the table were obtained, and produced by the above production method.

  In Examples 29 and 32 to 39, the Eu concentration of the activator contained in the phosphor was changed. Table 13 shows the emission characteristics when the phosphors of Examples 29 and 32 to 39 were excited at 400 nm. Table 14 shows the light emission characteristics when the phosphors of Examples 29 and 32 to 39 were excited at 460 nm. Specifically, Examples 29 and 32 to 39 have the same composition ratio, and the molar ratio of oxygen to nitrogen is 2.0. In Example 32, the Eu concentration was 3%, and in each of the phosphors of Examples 29 and 33 to 39, the Eu concentration was increased by 2% compared to Example 32.

  The phosphor of the example has a light emission peak wavelength at 480 to 550 nm in both excitation light sources of 400 nm and 460 nm. In particular, the phosphors of Examples 1 to 13 and Examples 27 to 39 corresponding to the general formula (I) and the general formula (III) have a peak wavelength at 495 to 530 nm. In general, the ideal peak value in the green component of the three-wavelength spectrum constituting white is 525 to 540 nm, and the peak wavelength of the phosphors of the examples is slightly shorter than this wavelength range. However, it is also possible to adjust to a desired peak wavelength position by changing the ratio of contained elements.

  With the phosphor of the embodiment having this specific emission wavelength region, the compatibility with a filter having characteristics in this region is enhanced, and the light emission characteristics such as the light flux amount and the luminance in the transmitted light of the filter can be improved.

  In addition, the phosphor of the general formula (II) having the same composition element as that of the general formula (I) has a peak wavelength in the range of 525 nm to 545 nm, which is substantially equivalent to the above-described general ideal green component. It is consistent and preferred. In particular, the emission wavelength can be shifted to the longer wavelength side by replacing a part of the alkaline earth metal element with another alkaline earth metal element. As a result, it is possible to appropriately adjust to a desired peak wavelength, and it is possible to cope with a wide range of wavelength ranges of various filters.

  Further, the phosphors of the examples show high emission luminance not only for 460 nm but also for 400 nm excitation light. That is, by mounting the above phosphor together with a light emitting element having an excitation light source of 400 nm, the phosphor can emit light more efficiently. In addition, since the excitation light source is in a wavelength range with low visibility, the color of the excitation light source is difficult to mix with the hue of the phosphor. Therefore, in a plurality of light emitting devices, the occurrence of color unevenness between the devices due to the shift of the peak wavelength of the excitation light source can be reduced, and the emitted colors of the devices can be made substantially uniform. An example of a light emitting device on which the phosphor of Embodiment 1 is mounted will be shown below.

(Light emitting device)
Examples of the light emitting device include a lighting device such as a fluorescent lamp, a display device such as a display and a radar, and a liquid crystal backlight. In the following embodiments, a light-emitting device including a light-emitting element that emits light in the short wavelength region from near ultraviolet to visible as an excitation light source will be described as an example. The light emitting element is small in size, has high power efficiency, and emits bright colors. In addition, since the light emitting element is a semiconductor element, there is no fear of a broken ball. In addition, it has excellent initial drivability and is strong against vibration and repeated on / off lighting. In addition, a light-emitting device in which a light-emitting element and a phosphor having excellent light-emitting characteristics are combined is preferable.

  The excitation light source preferably has a main emission peak in the ultraviolet region having low visibility characteristics. The relationship between the human eye feeling and the light wavelength is based on the visibility characteristic, and the visibility of the light at 555 nm is the highest, and the visibility decreases toward the short wavelength and the long wavelength. For example, light in the ultraviolet region used as an excitation light source belongs to a portion having low visibility, and the light emission color of the light emitting device is substantially determined by the light emission color of the fluorescent material used. Further, even when a color shift of a light emitting element due to a change in input current or the like occurs, a color shift of a fluorescent material that emits light in the visible light region can be suppressed to be extremely small. As a result, a light emitting device with little color tone change is provided. Can do. This is because the ultraviolet region generally has a wavelength shorter than 380 nm or 400 nm, but light having a wavelength of 420 nm or less is hardly visible in terms of visual sensitivity, so that the color tone is not greatly affected. Moreover, it is because the short wavelength light has higher energy than the long wavelength light.

  In the following embodiments, an excitation light source having a main emission peak in a region on the short wavelength side of visible light can also be used. In a light emitting device that covers an excitation light source with a coating member containing a fluorescent material, light emitted from the excitation light source is transmitted without being absorbed by the fluorescent material, and the transmitted light is emitted from the coating member to the outside. When light on the short wavelength side of visible light is used as the excitation light source, the light emitted to the outside can be used effectively. Therefore, loss of light emitted from the light emitting device can be reduced, and a highly efficient light emitting device can be provided. From this, this embodiment can also use an excitation light source having a main emission peak from 420 nm to 495 nm. In this case, blue light can be emitted. Further, since light having a relatively short wavelength is not used, a light-emitting device that is less harmful to the human body can be provided.

  However, as the excitation light source, in addition to the semiconductor light emitting element, an excitation light source having an emission peak wavelength in a short wavelength region from ultraviolet to visible light, such as a mercury lamp used in an existing fluorescent lamp, can be used as appropriate. The light emitting element in this specification includes not only an element that emits visible light but also an element that emits near ultraviolet light, far ultraviolet light, or the like. Further, the “main surface” refers to a surface on the light emitting surface side from which the light of the semiconductor light emitting element is extracted with respect to the surface of each component of the light emitting device such as a package and a lead electrode.

  By the way, there are various types of light emitting devices equipped with light emitting elements, such as a shell type and a surface mount type. In general, the bullet shape refers to a shape in which the shape of the resin constituting the outer surface is formed into a bullet shape. The surface-mounting type refers to one formed by filling a light-emitting element and a resin in a concave storage portion. Examples of various light emitting devices are given below.

  30 shows the light emitting device 60 according to Embodiment 1, wherein FIG. 30A is a perspective view of the light emitting device 60, and FIG. 30B is the light emitting device 60 taken along line XXXB-XXXB ′ of FIG. FIG. The light emitting device 60 is a side view type light emitting device which is a kind of surface mount type. The side view type is a light emitting device that emits light from the side surface adjacent to the mounting surface of the light emitting device, and can be made thinner.

  Specifically, the light-emitting device 60 of FIG. 30 includes a recess 14 and the light-emitting element 2 housed in the recess, and the recess 14 is filled with a resin containing the phosphor 3. The recess 14 is a part of the package 17, that is, the package 17 includes the recess 14 and a support body 16 connected to the recess 14. As shown in FIG. 30 (b), positive and negative lead electrodes 15 are interposed between the recess 14 and the support 16, thereby constituting a mounting surface of the light emitting element 2 in the recess 14. Further, the lead electrode 15 is exposed on the outer surface side of the package 17 and is provided along this outer shape. The light emitting element 2 is mounted on and electrically connected to the lead electrode 15 in the recess 14, and can emit light by receiving power supply from the outside via the lead electrode 15. FIG. 30A shows a general state in which the light emitting device 60 is mounted, that is, a wide surface orthogonal to the surface on which the light emitting element 2 is mounted is mounted as the bottom surface. With the above structure, the light emitting device 60 can emit light from a direction substantially parallel to the mounting surface of the light emitting element, that is, a side surface adjacent to the mounting surface of the light emitting device.

  Hereinafter, the light emitting device 60 will be described in detail. The package 17 is integrally molded so that one end of both the positive and negative lead electrodes 15 is inserted into the package 17. That is, the package 17 has a recess 14 capable of accommodating the light emitting element 2 on the main surface side, and one end of the positive lead electrode 15 and one end of the negative lead electrode 15 are formed on the bottom surface of the recess 14. The parts are separated from each other so that their main surfaces are exposed. An insulating molding material is filled between the positive and negative lead electrodes 15. In the present invention, the shape of the light emitting surface formed on the main surface side of the light emitting device is not limited to a rectangular shape, and may be an elliptical shape. By adopting various shapes, it is possible to make the light emitting surface as large as possible while maintaining the mechanical strength of the package side wall portion forming the recess 14 and to make the light emitting device capable of irradiating a wide range even if it is thinned. Can do.

  In the light emitting device 60 of the first embodiment, the positive and negative lead electrodes 15 are inserted so that the other end protrudes from the side surface of the package. The protruding portion of the lead electrode 15 is bent toward the back surface facing the main surface of the package 17 or toward the mounting surface side perpendicular to the main surface. In addition, the shape of the inner wall surface that forms the recess 14 is not particularly limited, but when the light emitting element 4 is placed, it is preferable to have a tapered shape in which the inner diameter gradually increases toward the opening. Thereby, the light emitted from the end face of the light emitting element 2 can be efficiently extracted in the direction of the emission observation surface. Further, in order to enhance the reflection of light, it is preferable to have a light reflecting function such as applying metal plating such as silver on the inner wall surface of the recess.

  In the light emitting device 60 of the first embodiment, the light emitting element 4 is placed in the concave portion 14 of the package 1 configured as described above, and a light-transmitting resin is filled so as to cover the light emitting element 4 in the concave portion. Then, the sealing member 18 is formed. This translucent resin contains a phosphor 3 that is a wavelength conversion member. As the translucent resin, a silicone resin composition is preferably used, but an insulating resin composition having translucency such as an epoxy resin composition and an acrylic resin composition can also be used.

(Light emitting element)
The light-emitting element can emit light from the ultraviolet region to the visible light region. In particular, a light emitting element having an emission peak wavelength of 240 nm to 480 nm, more preferably 290 nm to 460 nm, and more preferably 350 nm to 460 nm is used, and a light emitting layer capable of emitting light having an emission wavelength capable of efficiently exciting a fluorescent substance is provided. It is preferable. This is because a phosphor with high luminous efficiency can be provided by using an excitation light source in this range. Further, by using a semiconductor light emitting element as an excitation light source, a stable light emitting device with high efficiency, high output linearity with respect to input, and strong against mechanical shock can be obtained. The light in the short wavelength region of visible light is mainly in the blue light region. Hereinafter, a nitride semiconductor light emitting device will be described as an example of the light emitting device, but the present invention is not limited to this.

  Specifically, the light emitting element is preferably a nitride semiconductor element containing In or Ga. This is because the phosphor strongly emits light in the vicinity of 495 nm to 540 nm, and thus a light emitting element in the wavelength region is required. The light emitting element emits light having an emission peak wavelength in the short wavelength region from near ultraviolet to visible light, and at least one or more phosphors are excited by the light from the light emitting element to exhibit a predetermined emission color. Further, since the light emitting element can narrow the emission spectrum width, the phosphor can efficiently excite the phosphor, and the light emission device does not substantially affect the color change from the light emitting device. Can also be released.

In the light emitting element 2 according to the first embodiment, an LED chip which is an example of a nitride semiconductor element is employed. In addition, although a well-known thing can be utilized suitably for the light emitting element 2, when setting it as the light-emitting device provided with the fluorescent substance, the semiconductor light-emitting element which can light-emit the light which excites the fluorescent substance is preferable. Examples of such a semiconductor light emitting device include various semiconductors such as ZnSe and GaN. Nitride semiconductors capable of emitting short wavelengths capable of efficiently exciting fluorescent materials (In _x Al _y Ga _1-xy N, 0 ≦ X, 0 ≦ Y, X + Y ≦ 1) are preferable. Various emission wavelengths can be selected depending on the material of the semiconductor layer and the degree of mixed crystal. The light emitting element 2 used in the present embodiment has positive and negative electrodes formed on the same surface side, but the positive and negative electrodes may be formed on the corresponding surfaces. Good. Further, the positive and negative electrodes do not necessarily have to be formed one by one, and two or more each may be formed.

  Thus, by using the light emitted from the light emitting element as an excitation light source, an efficient light emitting device with low power consumption compared to a conventional mercury lamp can be realized. The light emitting device according to Embodiment 1 can use the phosphors of the above-described examples.

(Phosphor)
As the phosphor 3 in the first embodiment, the oxynitride phosphor described above is used. The phosphor 3 is preferably mixed in the resin at a substantially uniform ratio. Thereby, light without color unevenness is obtained. The brightness and wavelength of the light emitted from the light emitting device 60 are determined by the particle size of the phosphor 3 sealed in the light emitting device 60, the uniformity after coating, the thickness of the resin containing the phosphor, and the like. to be influenced. Specifically, if the amount and size of the phosphor excited before the light emitted from the light emitting element 2 is emitted to the outside of the light emitting device 60 at a site in the light emitting device 60 is unevenly distributed, Color unevenness occurs. Further, in the phosphor powder, light emission is considered to occur mainly on the particle surface. Therefore, if the average particle size is generally small, a surface area per unit weight of the powder can be secured and a reduction in luminance can be avoided. Further, the small-sized phosphor can diffuse and reflect light to prevent uneven color of the emitted color. On the other hand, the large particle size phosphor improves the light conversion efficiency. Therefore, light can be extracted efficiently by controlling the amount and particle size of the phosphor.

  Further, it is more preferable that the phosphor disposed in the light emitting device 60 is resistant to heat generated from the light source and weather resistant that is not affected by the use environment. This is because the fluorescence intensity generally decreases as the temperature of the medium increases. This is because as the temperature rises, intermolecular collision increases and potential energy loss is caused by non-radiative transition deactivation.

  However, the phosphor 3 can be blended so as to be partially distributed in the resin. As an example, by placing the light-emitting element 2 close to the light-emitting element 2, the light from the light-emitting element 2 can be wavelength-converted efficiently, and a light-emitting device with excellent light-emitting efficiency can be obtained.

  Further, two or more kinds of phosphors may be contained in the sealing member 18. Thereby, the wavelength of the main light source output from the light emitting layer can be converted by the first phosphor, and light that has been wavelength-converted by the second phosphor can be obtained. By adjusting the combination of the plurality of phosphors, the main light source, the light wavelength-converted by the first phosphor, the light wavelength-converted by the second phosphor, and the main light source directly the second fluorescence Various colors can be expressed by combining light that has been wavelength-converted by the body.

In the case of the light emitting device 60 according to the first embodiment, by combining the excitation light from the LED chip, the phosphor capable of emitting green excited by the LED chip, and the phosphor capable of emitting blue or red, White light having excellent light emission characteristics can be emitted. Examples of phosphors capable of emitting red light include (Ca _1-x Sr _x ) AlB _y SiN _{3 + y} : Eu (0 ≦ x ≦ 1.0, 0 ≦ y ≦ 0.5) or (Ca _1-z Sr _z ) ₂ Si ₅ N ₈ : Eu (0 ≦ z ≦ 1.0). By using these phosphors in combination, the half-value width of each component light corresponding to the three primary colors can be narrowed, that is, white light composed of sharp three wavelengths can be obtained. As a result, the overlap between the wavelengths is reduced, and the emission peak of each component light and the transmittance peak of the color filter can be substantially matched. Therefore, white light containing component light corresponding to the effective wavelength region is realized with high efficiency, and as a result, loss of the amount of light flux after passing through the filter can be reduced, so that the emission light with improved overall output and Become. In addition, the phosphor described above is excellent in stability at high temperature and high humidity, and thus can be a light-emitting device rich in weather resistance.

In addition, as an example of the phosphor, when the light from the light-emitting element is high-energy short-wavelength visible light, it is activated with a perylene derivative, ZnCdS: Cu, YAG: Ce, Eu, and / or Cr, which is an organic fluorescent material. Inorganic fluorescent materials such as nitrogen-containing CaO—Al ₂ O ₃ —SiO ₂ can be appropriately employed. Similarly, in addition to nitrogen-containing CaO—Al ₂ O ₃ —SiO ₂ activated with YAG: Ce, Eu and / or Cr, for example, described in JP-A-2005-19646, JP-A-2005-8844, etc. Any of the known fluorescent materials can be used. Alkaline earth, thiogallate, thiosilicate, zinc sulfide, and oxysulfide sulfide phosphors can also be selected as appropriate. For example, the alkaline earth phosphor includes MS: Re (M is one or more selected from the group consisting of Mg, Ca, Sr, and Ba, and Re is one or more selected from Eu and Ce). As the thiogallate phosphor, MN ₂ S ₄ : Re (M is one or more selected from Mg, Ca, Sr and Ba, N is one or more selected from Al, Ga, In and Y, and Re is Eu. M ₂ LS ₄ : Re (M is one or more selected from Mg, Ca, Ba, Sr, Ba, L is Si, and the like) One or more selected from Ge and Sn, Re is one or more selected from Eu and Ce), etc., and zinc sulfide phosphors are ZnS: K (K is one or more selected from Ag, Cu and Al) ) there is such, as the oxysulfide phosphor Ln ₂ O ₂ : Re (Ln is Y, La, 1 or more selected from Gd, Re is Eu, 1 or more selected from Ce), and the like.

  In addition, the sealing member 18 can appropriately contain an additive member. For example, by including a light diffusing material, the directivity from the light emitting element can be relaxed and the viewing angle can be increased.

(Embodiment 2)
Further, as a light emitting device according to Embodiment 2 of the present invention, a surface mount type light emitting device 70 is shown in FIG. FIG. 31A is a plan view of the light emitting device 70, and FIG. 31B is a sectional view. As the light emitting element 71, a nitride semiconductor light emitting element excited by ultraviolet light can be used. The light emitting element 71 may be a blue excited nitride semiconductor light emitting element. Here, the light emitting element 71 excited by ultraviolet light will be described as an example. The light emitting element 71 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. The light-emitting element 71 includes a p-type semiconductor layer and an n-type semiconductor layer (not shown), and a conductive wire 74 connected to the lead electrode 72 in the p-type semiconductor layer and the n-type semiconductor layer. Is formed. An insulating sealing material 73 is formed so as to cover the outer periphery of the lead electrode 72 to prevent a short circuit. Above the light emitting element 71, a translucent window 77 extending from a Kovar lid 76 at the top of the package 75 is provided. A uniform mixture of the phosphor 3 and the coating member 79 is applied to almost the entire inner surface of the translucent window portion 77.

  Next, each electrode of the die-bonded light emitting element 71 and each lead electrode 72 exposed from the bottom surface of the package recess are electrically connected by a conductive wire 74 such as an Ag wire. After sufficiently removing moisture in the recess of the package, sealing is performed with a Kovar lid 76 having a glass window 77 at the center, and seam welding is performed. In the glass window portion, the chlorosilicate phosphor 3 as a wavelength conversion member is previously contained in a slurry composed of 90 wt% nitrocellulose and 10 wt% γ-alumina, and is applied to the rear surface of the transparent window portion 77 of the lid 76. And a color conversion member is comprised by heat-hardening for 30 minutes at 220 degreeC. The light output from the light emitting element 71 of the light emitting device 70 formed in this way excites the phosphor 3 and can be a light emitting device capable of emitting a desired color with high luminance. This makes it possible to obtain a light emitting device with extremely simple chromaticity adjustment and excellent mass productivity and reliability.

  In the second embodiment, the light in the ultraviolet region used as the excitation light source belongs to a portion having low visibility, and the light emission color of the light emitting device is substantially determined by the light emission color of the fluorescent material used. For example, light emission capable of emitting high-intensity white light by mounting the phosphor described in Embodiment 1 on the light-emitting element in Embodiment 2 and further mounting the phosphor capable of emitting blue and red light. Can with equipment. Further, in the light emitting device of Embodiment 2, even when a color shift of the light emitting element due to a change in input current or the like occurs, the color shift of the fluorescent material that emits light in the visible light region can be suppressed to a very small value. Thus, a light-emitting device with little change in color tone can be provided. Although the ultraviolet region generally has a wavelength shorter than 380 nm or 400 nm, light having a wavelength of 420 nm or less is hardly visible in terms of visibility, so that the color tone is not greatly affected.

(Embodiment 3)
FIG. 32A shows a perspective view of the light emitting device 40 according to Embodiment 3 of the present invention. FIG. 32B is a cross-sectional view taken along the line XXXIIB-XXXIIB ′ of the semiconductor light emitting device 40 shown in FIG. Hereinafter, an outline of the light emitting device 40 according to Embodiment 3 will be described with reference to FIGS. 32 (a) and 32 (b). The light emitting device 40 is configured such that a package 12 having a space that opens in a substantially concave shape toward the top is mounted on the lead frame 4. Further, a plurality of light emitting elements 2 are mounted on the exposed lead frame 4 in the space of the package 12. That is, the package 12 is a frame that surrounds the light emitting element 2. In addition, a protective element 13 such as a Zener diode, which is energized when a voltage higher than a specified voltage is applied, is also placed in the open space of the package 12. Further, the light emitting element 2 is electrically connected to the lead frame 4 via bonding wires 5 and bumps. In addition, the open space of the package 12 is filled with the sealing resin 6.

  The phosphor 3 contained in the package 12 is shown in FIG. 32B (the phosphor 3 in FIG. 32A is omitted). As this phosphor 3, the above-mentioned chlorosilicate phosphor can be used, and the phosphor content in the resin 6 is the same as in the first embodiment.

(Embodiment 4)
FIG. 33 shows a bullet-type light emitting device 1 according to the fourth embodiment. The light-emitting device 1 is in a concave cup 10 formed by a lead frame 4 made of a conductive member. The light-emitting device 2 is placed on the lead frame 4 and is emitted from the light-emitting element 2. A phosphor 3 that converts the wavelength of at least part of the light. The phosphor of the first embodiment can be mounted on the phosphor 3 as in the second embodiment. The light-emitting element 2 is a light-emitting element having an emission peak wavelength at about 360 nm to 460 nm. Positive and negative electrodes 9 formed on the light emitting element 2 are electrically connected to the lead frame 4 via conductive bonding wires 5. Further, the light emitting element 2, the lead frame 4, and the bonding wire 5 are covered with a shell-shaped mold 11 so that the lead frame electrode 4 a which is a part of the lead frame 4 protrudes. The mold 11 is filled with a light-transmitting resin 6, and the resin 6 contains a phosphor 3 that is a wavelength conversion member. As the resin 6, it is preferable to use a silicone resin composition such as a silicone resin having a siloxane bond in the molecule or a siloxane skeleton fluororesin. Thereby, it can be set as the sealing resin excellent in light resistance and heat resistance. On the other hand, a silicone resin generally has a high gas permeability due to a long bond distance between elements, and moisture in an environmental atmosphere is easily transmitted. Therefore, it tends to facilitate the elution of the phosphor components under high temperature and high humidity. However, since the phosphor of the present invention suppresses the elution of chlorine from the phosphor itself, the chlorine component that permeates the silicone resin can be significantly reduced even when combined with the silicone resin composition. That is, combining the phosphor of the present invention with a silicone resin is preferable because the advantages of the silicone resin can be enjoyed while avoiding the influence of chlorine on the member. Moreover, the resin 6 can also use the insulating resin composition which has translucency, such as an epoxy resin composition and an acrylic resin composition. By supplying electric power from an external power source to the lead frame electrode 4 a protruding from the resin 6, light is emitted from the light emitting layer 8 contained in the layer of the light emitting element 2. The emission peak wavelength output from the light emitting layer 8 has an emission spectrum near 495 nm or less in the ultraviolet to blue region. Part of the emitted light excites the phosphor 3, and light having a wavelength different from the wavelength of the main light source from the light emitting layer 8 is obtained.

(Embodiment 5)
Next, FIG. 34A shows a light-emitting device 20 according to Embodiment 5 of the present invention. In this light emitting device 20, the same members as those in the light emitting device 1 according to Embodiment 4 are denoted by the same reference numerals, and the description thereof is omitted. In the light emitting device 20, the resin 6 containing the phosphor 3 is filled only in the concave cup 10 molded by the lead frame 4. The phosphor 3 is not contained in the resin 6 filled inside the mold 11 and outside the cup 10. The resin containing phosphor 3 and the resin not containing are preferably the same, but they may be different. In the case of different types of resins, the softness can be changed using the difference in temperature required for each resin to cure.

  In the light emitting device 20, since the light emitting element 2 is placed at substantially the center of the bottom surface forming the opening in the cup 10, the light emitting element 2 is embedded in the resin 6 including the phosphor 3. In order for the light from the light emitting layer 8 to be wavelength-converted by the phosphor 3 without unevenness, the light from the light emitting element has only to pass through the phosphor-containing resin uniformly. That is, the phosphor-containing resin film through which light from the light emitting layer 8 passes may be made uniform. Therefore, the size of the cup 10 and the mounting position of the light emitting element 2 may be determined so that the distance from the periphery of the light emitting element 2 to the wall surface and upper part of the cup 10 is uniform. With this light emitting device 20, it becomes easy to uniformly adjust the film thickness of the resin 6 containing the phosphor 3.

  Further, similarly to the first embodiment, the phosphor 3 can be blended so as to be partially unevenly distributed in the resin. As an example, a light emitting device 50 shown in FIG. 34B is formed by forming a phosphor layer having a substantially uniform thickness in the vicinity of the periphery of the light emitting element 2. As a result, the amount of phosphor through which light emitted from the light emitting element 2 passes to the periphery is substantially constant, that is, since the same amount of phosphor is wavelength-converted, a light emitting device with reduced color unevenness can be obtained. Further, the type of phosphor 3 to be placed can be the same as in the second embodiment.

(Embodiment 6)
Furthermore, as a light-emitting device according to Embodiment 6 of the present invention, a cap-type light-emitting device 30 is shown in FIG. As the light emitting element 2, a light emitting element having an emission peak wavelength at about 400 nm is used. The light emitting device 30 is configured by covering a cap 31 made of a light transmissive resin in which the phosphor 3 is dispersed on the surface of the mold 11 of the light emitting device 20 of the second embodiment.

  The cap 31 has the phosphor 3a uniformly dispersed in the light transmissive resin 6a. The resin 6 a containing the phosphor 3 a is molded into a shape that fits into the shape of the outer surface of the mold 11 of the light emitting device 30. Alternatively, a manufacturing method is also possible in which a light-transmitting resin 6a containing a predetermined in-frame phosphor is put, and then the light emitting device 30 is pushed into the mold and molded. As a specific material of the resin 6a of the cap 31, a transparent resin, silica gel, glass, an inorganic binder, etc. excellent in temperature characteristics and weather resistance such as an epoxy resin, a urea resin, and a silicone resin are used. 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 phosphor 3a used for the cap 31 can be not only one type but also a mixture of a plurality of phosphors or a layered structure.

  In the light emitting device 30, the phosphor 3 a can be contained only in the resin 6 a in the cap 31, but in addition to this, the cup 6 may be filled with the resin 6 containing the phosphor 3. The types of the phosphors 3 and 3a may be the same or different, and each of the resins 6 and 6a may have a plurality of phosphors. As a result, various emission colors can be realized. An example is a light emitting device that emits white light. The light emitted from the light emitting element 2 excites the phosphor 3 and emits light from blue green to green and from yellow to red. A part of the light emitted from the phosphor 3 excites the phosphor 3a of the cap 31, and emits light from green to a yellow region. Due to the mixed color light of these phosphors, white light is emitted from the surface of the cap 31 to the outside. The various phosphors to be mounted are the same as in the first embodiment.

  The phosphor of the present invention and a light-emitting device using the phosphor are extremely excellent in light emission characteristics using a fluorescent display tube, display, PDP, CRT, FL, FED, projection tube, etc., particularly a blue light-emitting diode or an ultraviolet light-emitting diode as a light source. It can be suitably used for white illumination light sources, LED displays, backlight light sources, traffic lights, illumination switches, various sensors, various indicators, and the like.

The excitation spectrum of the fluorescent substance which concerns on Example 1 thru | or 5 and the comparative example 1 is shown. The excitation spectrum of the fluorescent substance concerning Example 1 is shown. The excitation spectrum of the fluorescent substance which concerns on Example 2 is shown. The excitation spectrum of the fluorescent substance which concerns on Example 3 is shown. The reflection spectrum of the fluorescent substance which concerns on Example 1 thru | or 5 is shown. The reflection spectrum of the fluorescent substance which concerns on Example 1 is shown. The reflection spectrum of the fluorescent substance which concerns on Example 2 is shown. The reflection spectrum of the fluorescent substance which concerns on Example 3 is shown. The reflection spectrum of the fluorescent substance which concerns on Example 4 is shown. The reflection spectrum of the fluorescent substance concerning Example 5 is shown. The emission spectrum at the time of exciting the fluorescent substance which concerns on Example 1 thru | or 5 and the comparative example 1 at 400 nm is shown. The emission spectrum at the time of exciting the fluorescent substance which concerns on Example 1 at 400 nm is shown. The emission spectrum at the time of exciting the fluorescent substance concerning Example 2 at 400 nm is shown. The emission spectrum at the time of exciting the fluorescent substance concerning Example 5 at 400 nm is shown. The emission spectrum at the time of exciting the fluorescent substance which concerns on Example 1 thru | or 5 and the comparative example 1 at 460 nm is shown. The 5000 times enlarged photograph of the fluorescent substance which concerns on Example 3 is shown. The excitation spectrum of the fluorescent substance which concerns on Example 14 thru | or 18 is shown. The reflection spectrum of the fluorescent substance which concerns on Example 14 thru | or 18 is shown. The emission spectrum at the time of exciting the fluorescent substance which concerns on Example 14 thru | or 18 at 400 nm is shown. The emission spectrum at the time of exciting the fluorescent substance which concerns on Example 14 thru | or 18 at 460 nm is shown. The excitation spectrum of the fluorescent substance which concerns on Examples 27 thru | or 31 is shown. The excitation spectrum of the fluorescent substance concerning Example 27 is shown. The excitation spectrum of the fluorescent substance concerning Example 28 is shown. The excitation spectrum of the fluorescent substance concerning Example 29 is shown. The excitation spectrum of the fluorescent substance concerning Example 30 is shown. The reflection spectrum of the fluorescent substance which concerns on Examples 27 thru | or 31 is shown. The emission spectrum at the time of exciting the phosphor which concerns on Examples 27 thru | or 31 at 400 nm is shown. The emission spectrum at the time of exciting the fluorescent substance which concerns on Example 27 thru | or 31 at 460 nm is shown. A 5000-times enlarged photograph of the phosphor according to Example 29 is shown. FIG. 30A is a perspective view and FIG. 30B is a cross-sectional view of the light-emitting device according to Embodiment 1. FIG. FIG. 31A is a plan view and FIG. 31B is a cross-sectional view of a light-emitting device according to Embodiment 2. FIG. FIG. 32A is a perspective view and FIG. 32B is a cross-sectional view of a light-emitting device according to Embodiment 3. 7 is a cross-sectional view of a light emitting device according to Embodiment 4. FIG. FIG. 34A is a cross-sectional view of the light-emitting device according to Embodiment 5, and FIG. 34B is another cross-sectional view according to Embodiment 5. FIG. 10 is a cross-sectional view of a light emitting device according to a sixth embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 20, 30, 40, 50, 60, 70 ... Light emitting device 2 ... Light emitting element 3 ... Phosphor 3a ... Small particle fluorescent substance 4 ... Lead frame 4a ... Lead frame electrode 5 ... Bonding wire 6 ... Resin 6a ... Resin 8 ... Light emitting layer 9 ... Electrode 10 ... Cup 11 ... Mold 12 ... Package 13 ... Protective element 14 ... Recess 15 ... Lead electrode 16 ... Support 17 ... Package 18 ... Sealing member 31 ... Cap 71 ... Light emitting element 72 ... Lead electrode 73 ... Insulating encapsulant 74 ... Conductive wire 75 ... Package 76 ... Kovar lid 77 ... Translucent window (glass window)
79 ... Coating member

Claims (2)

A phosphor containing at least silicon, oxygen, and nitrogen, activated by europium, capable of absorbing ultraviolet light or blue light and emitting green light;
A phosphor having a general formula represented by Ba ₂ Si ₂ O ₃ N ₂ : Eu . An excitation light source that emits excitation light;
A phosphor that absorbs part of the light from the excitation light source and emits fluorescence,
The phosphor according to claim 1 is used as the phosphor.