JP2008088316A - PHOSPHOR MAINLY COMPOSED OF Ta OXIDE AND ITS MANUFACTURING METHOD - Google Patents
PHOSPHOR MAINLY COMPOSED OF Ta OXIDE AND ITS MANUFACTURING METHOD Download PDFInfo
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- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 title claims abstract description 76
- 238000004519 manufacturing process Methods 0.000 title claims description 10
- 239000000203 mixture Substances 0.000 claims abstract description 16
- 229910052719 titanium Inorganic materials 0.000 claims abstract description 8
- 238000002844 melting Methods 0.000 claims abstract description 7
- 230000008018 melting Effects 0.000 claims abstract description 7
- 238000005286 illumination Methods 0.000 claims abstract description 6
- 230000005284 excitation Effects 0.000 claims description 33
- 238000010438 heat treatment Methods 0.000 claims description 24
- 238000005245 sintering Methods 0.000 claims description 19
- 229910052688 Gadolinium Inorganic materials 0.000 claims description 8
- 229910052771 Terbium Inorganic materials 0.000 claims description 7
- 229910052693 Europium Inorganic materials 0.000 claims description 6
- -1 composed of Ta oxide Chemical compound 0.000 claims description 6
- 229910052761 rare earth metal Inorganic materials 0.000 claims description 6
- 229910052718 tin Inorganic materials 0.000 claims description 6
- 229910052749 magnesium Inorganic materials 0.000 claims description 5
- 150000003839 salts Chemical class 0.000 claims description 5
- RPACBEVZENYWOL-XFULWGLBSA-M sodium;(2r)-2-[6-(4-chlorophenoxy)hexyl]oxirane-2-carboxylate Chemical compound [Na+].C=1C=C(Cl)C=CC=1OCCCCCC[C@]1(C(=O)[O-])CO1 RPACBEVZENYWOL-XFULWGLBSA-M 0.000 claims description 5
- 239000000126 substance Substances 0.000 claims description 5
- 229910052692 Dysprosium Inorganic materials 0.000 claims description 4
- 229910052782 aluminium Inorganic materials 0.000 claims description 4
- 238000000034 method Methods 0.000 claims description 4
- 229910052684 Cerium Inorganic materials 0.000 claims description 3
- 229910052691 Erbium Inorganic materials 0.000 claims description 2
- 229910052689 Holmium Inorganic materials 0.000 claims description 2
- 229910052779 Neodymium Inorganic materials 0.000 claims description 2
- 229910052772 Samarium Inorganic materials 0.000 claims description 2
- 229910052715 tantalum Inorganic materials 0.000 claims description 2
- 229910052725 zinc Inorganic materials 0.000 abstract description 8
- 238000009877 rendering Methods 0.000 abstract description 4
- 238000010348 incorporation Methods 0.000 abstract 1
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 9
- 239000000463 material Substances 0.000 description 5
- 235000002639 sodium chloride Nutrition 0.000 description 5
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 4
- 230000008859 change Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 238000002441 X-ray diffraction Methods 0.000 description 3
- 230000006872 improvement Effects 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 239000007832 Na2SO4 Substances 0.000 description 2
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 2
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 description 2
- 229910010413 TiO 2 Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 229910052791 calcium Inorganic materials 0.000 description 2
- 239000011575 calcium Substances 0.000 description 2
- 239000003086 colorant Substances 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000000295 emission spectrum Methods 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 239000004973 liquid crystal related substance Substances 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 229910000029 sodium carbonate Inorganic materials 0.000 description 2
- 239000011780 sodium chloride Substances 0.000 description 2
- 229910052938 sodium sulfate Inorganic materials 0.000 description 2
- 235000011152 sodium sulphate Nutrition 0.000 description 2
- 229910052582 BN Inorganic materials 0.000 description 1
- PZNSFCLAULLKQX-UHFFFAOYSA-N Boron nitride Chemical compound N#B PZNSFCLAULLKQX-UHFFFAOYSA-N 0.000 description 1
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- KKCBUQHMOMHUOY-UHFFFAOYSA-N Na2O Inorganic materials [O-2].[Na+].[Na+] KKCBUQHMOMHUOY-UHFFFAOYSA-N 0.000 description 1
- 229910052581 Si3N4 Inorganic materials 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 239000012752 auxiliary agent Substances 0.000 description 1
- PSBUJOCDKOWAGJ-UHFFFAOYSA-N azanylidyneeuropium Chemical compound [Eu]#N PSBUJOCDKOWAGJ-UHFFFAOYSA-N 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- PMHQVHHXPFUNSP-UHFFFAOYSA-M copper(1+);methylsulfanylmethane;bromide Chemical compound Br[Cu].CSC PMHQVHHXPFUNSP-UHFFFAOYSA-M 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- OGPBJKLSAFTDLK-UHFFFAOYSA-N europium atom Chemical compound [Eu] OGPBJKLSAFTDLK-UHFFFAOYSA-N 0.000 description 1
- RSEIMSPAXMNYFJ-UHFFFAOYSA-N europium(III) oxide Inorganic materials O=[Eu]O[Eu]=O RSEIMSPAXMNYFJ-UHFFFAOYSA-N 0.000 description 1
- 150000004673 fluoride salts Chemical class 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 239000002223 garnet Substances 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 238000004020 luminiscence type Methods 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- 239000008188 pellet Substances 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 150000002910 rare earth metals Chemical class 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 1
- 235000017550 sodium carbonate Nutrition 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 238000012916 structural analysis Methods 0.000 description 1
- PBCFLUZVCVVTBY-UHFFFAOYSA-N tantalum pentoxide Inorganic materials O=[Ta](=O)O[Ta](=O)=O PBCFLUZVCVVTBY-UHFFFAOYSA-N 0.000 description 1
- 229910052727 yttrium Inorganic materials 0.000 description 1
- VWQVUPCCIRVNHF-UHFFFAOYSA-N yttrium atom Chemical compound [Y] VWQVUPCCIRVNHF-UHFFFAOYSA-N 0.000 description 1
Classifications
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
- H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
- H01L2224/42—Wire connectors; Manufacturing methods related thereto
- H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
- H01L2224/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
- H01L2224/4805—Shape
- H01L2224/4809—Loop shape
- H01L2224/48091—Arched
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
- H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
- H01L2224/42—Wire connectors; Manufacturing methods related thereto
- H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
- H01L2224/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
- H01L2224/481—Disposition
- H01L2224/48151—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive
- H01L2224/48221—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked
- H01L2224/48245—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being metallic
- H01L2224/48247—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being metallic connecting the wire to a bond pad of the item
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
- H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
- H01L2224/42—Wire connectors; Manufacturing methods related thereto
- H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
- H01L2224/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
- H01L2224/481—Disposition
- H01L2224/48151—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive
- H01L2224/48221—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked
- H01L2224/48245—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being metallic
- H01L2224/48257—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being metallic connecting the wire to a die pad of the item
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Abstract
Description
本発明はTa酸化物を主体とする蛍光体に関し、特に、Ta酸化物に主たる発光元素としてEuを含有させ、それにより青色光でも励起可能とした赤色蛍光体に関する。 The present invention relates to a phosphor mainly composed of Ta oxide, and more particularly, to a red phosphor that contains Eu as a main light emitting element in Ta oxide, and can be excited even by blue light.
最近、発光強度の高い白色LEDが製品化され始めており、照明やバックライト等の用途において広く使われるようになっている。白色LEDは、水銀フリー、低消費電力、直流駆動のため輝度調節が比較的容易、といった多くのメリットを備えているため、その需要は高まる一方である。 Recently, white LEDs with high emission intensity have been commercialized, and are widely used in applications such as lighting and backlighting. The demand for white LEDs is increasing because they have many advantages such as mercury-free, low power consumption, and relatively easy brightness control due to direct current drive.
現在、白色LEDの白色光は青色LEDと黄色蛍光体（YAG：イットリウム・アルミニウム・ガーネット）との組合せにより実現されているため、光が青白いという特徴を持つ。一般に店舗やリビングルームでは、演色性の高い照明や暖かみを感じさせる照明が求められるため、このような環境における白色LEDの使用は不適当であった。 Currently, white light from white LEDs is realized by a combination of blue LEDs and yellow phosphors (YAG: yttrium, aluminum, and garnet). In general, in stores and living rooms, lighting with high color rendering properties and lighting that makes you feel warm are required, so the use of white LEDs in such an environment is inappropriate.
青白い光の演色性を高めるためには赤み成分を付加する必要があるため、白色LEDに添加するための適切な赤色蛍光体が求められている。しかし、現在赤色蛍光体として使用されているものは、発光効率が低い、時間経過により劣化しやすい、可視光励起できない等の問題があった。 In order to enhance the color rendering properties of pale light, it is necessary to add a red component, and therefore, an appropriate red phosphor to be added to a white LED is required. However, those currently used as red phosphors have problems such as low luminous efficiency, easy deterioration with time, and inability to excite visible light.
非特許文献１には、以上のような問題を解決することを目的とした赤色蛍光体が開示されている。これによると、窒化ケイ素、窒化アルミニウム、窒化カルシウム、窒化ユーロピウム粉末を、水分と空気を遮断したグローブボックス内で混合し、その後窒化ホウ素製のるつぼに入れて窒素中、10気圧、1800℃で反応させることにより、ユーロピウムが固溶したカルシウム・アルミニウム・シリコン三窒化物（CaAlSiN3）赤色蛍光体粉末が得られる。この方法によって得られる赤色蛍光体は、450〜490nmの青色LED光源を励起光として使用できるとされている。また、-240℃〜100℃の温度範囲で劣化しないとも報告されている。 Non-Patent Document 1 discloses a red phosphor intended to solve the above problems. According to this, silicon nitride, aluminum nitride, calcium nitride, and europium nitride powder are mixed in a glove box where moisture and air are blocked, and then placed in a boron nitride crucible and reacted in nitrogen at 10 atm and 1800 ° C. By doing so, calcium / aluminum / silicon trinitride (CaAlSiN 3 ) red phosphor powder in which europium is dissolved is obtained. The red phosphor obtained by this method is said to be able to use a blue LED light source of 450 to 490 nm as excitation light. It is also reported that it does not deteriorate in the temperature range of -240 ° C to 100 ° C.
しかし、非特許文献１に記載されている赤色蛍光体は高圧の窒素雰囲気下で製造する必要があるため、製造設備やコストの面で改善が望まれる。そこで、本願発明者らは、特に白色LEDに好適に適用できる赤色蛍光体を得るべく鋭意研究を行った結果、Ta2O5等のTa酸化物を主体とし、そこにEuを含有させた新規な赤色蛍光体を得ることに成功した。 However, since the red phosphor described in Non-Patent Document 1 needs to be manufactured in a high-pressure nitrogen atmosphere, improvement is desired in terms of manufacturing equipment and cost. Therefore, the inventors of the present invention have conducted intensive research to obtain a red phosphor that can be suitably applied particularly to white LEDs, and as a result, a novel oxide mainly composed of Ta oxide such as Ta 2 O 5 and containing Eu. We succeeded in obtaining a new red phosphor.
以上のようにして成された本発明に係る赤色蛍光体は、Ta:Euの原子数比が0.99:0.01〜0.60:0.40であるEuを含有することを特徴とする、Ta酸化物を主体とする赤色蛍光体である。 The red phosphor according to the present invention formed as described above mainly contains Ta oxide, characterized in that it contains Eu with an atomic ratio of Ta: Eu of 0.99: 0.01 to 0.60: 0.40. Red phosphor.
このTa:Euの原子数比は、好適には0.95:0.05〜0.70:0.30とするとよい。 The Ta: Eu atomic ratio is preferably 0.95: 0.05 to 0.70: 0.30.
本発明に係る赤色蛍光体は更に、Ta:Eu:Znの原子数比が0.985:0.01:0.005〜0.45:0.40:0.15であるZnを含有するものであってもよい。 The red phosphor according to the present invention may further contain Zn having a Ta: Eu: Zn atomic ratio of 0.985: 0.01: 0.005 to 0.45: 0.40: 0.15.
更に、Mg、Gd、Sn、Ti、Tbのいずれか1つ又は複数を含有するものであってもよい。 Furthermore, it may contain one or more of Mg, Gd, Sn, Ti, and Tb.
更には、本発明に係る赤色蛍光体はTa及びAl酸化物を主体とするものであってもよく、その場合、Euは(Ta・Al):Euの原子数比が0.99:0.01〜0.60:0.40であるようにする。また、Ta酸化物にはLa等の酸化物が含まれていてもよい。 Furthermore, the red phosphor according to the present invention may be mainly composed of Ta and Al oxides. In this case, Eu has a (Ta · Al): Eu atomic ratio of 0.99: 0.01 to 0.60: Make sure it is 0.40. Further, the Ta oxide may contain an oxide such as La.
本発明に係る赤色蛍光体を製造する方法は各種あるが、例えば次のような方法を用いることができる。
すなわち、Ta酸化物とEu酸化物を、Ta:Euの原子数比が0.99:0.01〜0.60:0.40となるように混合し、
該混合物を1200℃以上、Ta酸化物の溶融温度以下の温度で加熱・焼結する。
There are various methods for producing the red phosphor according to the present invention. For example, the following method can be used.
That is, Ta oxide and Eu oxide are mixed so that the Ta: Eu atomic ratio is 0.99: 0.01 to 0.60: 0.40,
The mixture is heated and sintered at a temperature of 1200 ° C. or higher and lower than the melting temperature of Ta oxide.
ここで、上記Ta酸化物として例えばTa2O5を、Eu酸化物として例えばEu2O3を用いることができる。この場合、加熱温度の最高値は、Ta2O5の溶融温度である1785℃となる。 Here, for example, Ta 2 O 5 can be used as the Ta oxide, and Eu 2 O 3 can be used as the Eu oxide. In this case, the maximum heating temperature is 1785 ° C., which is the melting temperature of Ta 2 O 5 .
上記のZnを含有する赤色蛍光体を製造する場合、上記混合物に更にZn酸化物を、Ta:Eu:Znの原子数比が0.985:0.01:0.005〜0.45:0.40:0.15となるように加える。加熱温度範囲は同じでよい。 When the above red phosphor containing Zn is produced, a Zn oxide is further added to the above mixture so that the atomic ratio of Ta: Eu: Zn is 0.985: 0.01: 0.005 to 0.45: 0.40: 0.15. The heating temperature range may be the same.
上記の、更にMg、Gd、Sn、Ti、Tbのいずれか1つ又は複数を含有するEu-Ta酸化物蛍光体の場合、Ta酸化物とEu酸化物を混合する際に、或いはそれらを混合した後、それらMg等の元素の酸化物又はそれら酸化物の混合物を加え、その後は上記同様に加熱・焼結することにより、蛍光体を得ることができる。なお、これらMg等の元素の酸化物又はそれら酸化物の混合物の混合量は、目的に応じて適宜選択される。 In the case of the Eu-Ta oxide phosphor further containing any one or more of Mg, Gd, Sn, Ti, and Tb, when mixing Ta oxide and Eu oxide, or mixing them Then, the phosphors can be obtained by adding oxides of elements such as Mg or a mixture of these oxides, and then heating and sintering in the same manner as described above. In addition, the mixing amount of these oxides of Mg or the like or a mixture of these oxides is appropriately selected according to the purpose.
上記酸化物混合体には、焼結助剤を添加してもよい。焼結助剤を加えることにより、加熱・焼結温度を下げることができ、本発明に係る蛍光体の製造工程を簡略化し、コストを下げることができる。焼結助剤としては、Na塩（例えば、Na2SO4、Na2C03、NaCl、Na2O等）やK塩（例えば、KCl等）を用いることができる。その含有量は30〜60重量%とすることが望ましい。これよりも少ないと十分な焼結補助作用が得られず、この範囲を超えると発光体自体の発光効率が低下するおそれがある。 A sintering aid may be added to the oxide mixture. By adding a sintering aid, the heating / sintering temperature can be lowered, the production process of the phosphor according to the present invention can be simplified, and the cost can be reduced. As a sintering aid, Na salt (for example, Na2SO4, Na2C03, NaCl, Na2O, etc.) or K salt (for example, KCl, etc.) can be used. The content is desirably 30 to 60% by weight. If it is less than this, a sufficient sintering assisting action cannot be obtained, and if it exceeds this range, the luminous efficiency of the phosphor itself may be lowered.
本発明に係る赤色蛍光体は、Ta酸化物を主体とし、Euを含有するものであるが、このうち主としてEuが発光源として作用し、赤色蛍光を発する。明確な構造は未だ解明されていないが、後述するＸ線回折の結果から判断すると、恐らくTa酸化物がホストの役割を担い、発光源となるEuを囲うカゴ状の構造を有するものと想定される。 The red phosphor according to the present invention is mainly composed of Ta oxide and contains Eu. Among them, Eu mainly functions as a light emission source and emits red fluorescence. Although a clear structure has not yet been elucidated, judging from the results of X-ray diffraction described later, it is assumed that Ta oxide probably plays a host role and has a cage-like structure that surrounds Eu as a light emission source. The
従って、発光源としてEuと同様の化学的性質を有する希土類元素を用いても、本発明は同様に成立し得る。すなわち、Ta酸化物によるカゴ構造中に発光源としての希土類元素を含有する、Ta酸化物を主体とする蛍光体も本発明の範疇に入るものである。ここにおける希土類元素には、例えば、Er, Dy, Sm, Tb, Ce, Gd, Nd, Dy, Ho等を挙げることができる。 Therefore, even when a rare earth element having the same chemical properties as Eu is used as the light emitting source, the present invention can be similarly realized. That is, a phosphor mainly composed of Ta oxide, which contains a rare earth element as a light emitting source in the cage structure of Ta oxide, also falls within the scope of the present invention. Examples of the rare earth element include Er, Dy, Sm, Tb, Ce, Gd, Nd, Dy, and Ho.
本発明に係る蛍光体のうち特にEuを発光源とする赤色蛍光体は、後述するように高い発光効率及び高い発光安定性を備えているほか、青色波長に励起波長域を有しているため、可視光励起により強い赤色発光を行うことができる。現在、白色LEDは青色発光LEDと黄色蛍光体の組み合わせにより構成されているが、前記の通り発光色がやや青白いという特徴があり、暖色系が求められる用途には不適であるとされていたが、本発明に係る赤色蛍光体をそこに適度の量加えることにより、演色性に優れた白色光を得ることができるようになる。これは、LEDの照明光源としての使用に大きな道を開くものとなる。 Among the phosphors according to the present invention, a red phosphor having Eu as a light source, in particular, has high emission efficiency and high emission stability as will be described later, and also has an excitation wavelength region in the blue wavelength. Intense red light emission can be performed by visible light excitation. Currently, white LEDs are composed of a combination of blue light-emitting LEDs and yellow phosphors, but as described above, the emission color is slightly pale, and it was considered unsuitable for applications that require warm colors. By adding an appropriate amount of the red phosphor according to the present invention, white light excellent in color rendering can be obtained. This opens up a huge path for the use of LEDs as illumination sources.
また、本発明に係る蛍光体は、その製造が非常に容易であるという特長を持つ。すなわち、製造時の加熱は常圧・空気中で行うことができるため、上記非特許文献１に記載のもののような特別な装置を必要としない。そして、原料の酸化物も一般的に容易に入手することができる。従って、低コストで製造することができる。また、その加熱温度も比較的低い温度を用いることができる。 Further, the phosphor according to the present invention has a feature that it is very easy to manufacture. That is, since the heating at the time of manufacture can be performed in normal pressure and air, a special apparatus like the thing of the said nonpatent literature 1 is not required. In general, the raw material oxide can also be easily obtained. Therefore, it can be manufactured at low cost. Also, the heating temperature can be a relatively low temperature.
Euを発光源とする赤色蛍光体を白色LED製造の際に使用することにより、従来は青白く無機質な印象を与えていた白色LEDの発色を、赤みを帯びた暖かく感じられる発色とすることができるようになる。本発明に係る蛍光体を用いた発光装置の一例として、砲弾型LED発光装置を図１５に示す。砲弾型LED発光装置１０は、発光光束に指向性を与えるためのプラスチック製砲弾型レンズ１１の中にLED１２を埋設したもので、本願発明に係る蛍光体１３は、発光源であるLED１２の上に塗布して使用することができる。 By using a red phosphor with Eu as the light source when manufacturing white LEDs, the color development of white LEDs, which used to give a white and inorganic impression in the past, can be made reddish and warm. It becomes like this. As an example of a light emitting device using the phosphor according to the present invention, a bullet type LED light emitting device is shown in FIG. The bullet-type LED light-emitting device 10 has an LED 12 embedded in a plastic bullet-type lens 11 for giving directivity to a luminous flux, and the phosphor 13 according to the present invention is placed on the LED 12 that is a light source. It can be applied and used.
本発明に係る蛍光体はその他に、単独に各色の発光源として、又はその他の発光源と組み合わせることにより各種色を実現する光源の構成要素として用いることができるのはもちろん、液晶パネル（LCD）のバックライト等の各種発光装置に好適に用いることができる。 In addition, the phosphor according to the present invention can be used alone as a light source for each color, or as a component of a light source that realizes various colors by combining with other light sources, as well as a liquid crystal panel (LCD). It can be suitably used for various light emitting devices such as backlights.
本発明に係る赤色蛍光体は、青色域の可視光の他、紫外線によっても励起して赤色蛍光を発する。従って、紫外線により励起して発光する照明装置や表示装置の蛍光体としても使用することができる。 The red phosphor according to the present invention emits red fluorescence when excited by ultraviolet rays in addition to visible light in the blue range. Therefore, it can be used as a phosphor for a lighting device or a display device that emits light when excited by ultraviolet rays.
本発明に係る蛍光体の基本的な構成は、Ta酸化物とEu等の希土類発光元素が原子レベルで混合した構成にある。発光源としてEuを用いる場合、その原料物質としてはフッ化物塩、炭酸塩、酸化物等が挙げられるが、なかでも酸化物が好ましい。この場合、最も典型的には出発物質としてTa2O5とEu2O3を用いることができる。 The basic structure of the phosphor according to the present invention is a structure in which Ta oxide and rare earth light emitting elements such as Eu are mixed at the atomic level. When Eu is used as the light emitting source, examples of the raw material include fluoride salts, carbonates, oxides, etc. Among them, oxides are preferable. In this case, Ta 2 O 5 and Eu 2 O 3 can be most typically used as starting materials.
これらの酸化物は通常、粉末で得られるが、両者を単純に混合し、それを加熱することにより、両酸化物の構造が変化し、Euを発光源とする赤色蛍光体が形成される。なお、混合物にはTa2O5及びEu以外の成分が含まれていてもよい。 These oxides are usually obtained in powder form, but when both are simply mixed and heated, the structure of both oxides changes, and a red phosphor having Eu as the light emission source is formed. The mixture may contain components other than Ta 2 O 5 and Eu.
加熱温度は1200℃以上とする。この温度未満では、前記のようなTa酸化物ホストとEu発光源のカゴ状構造が良好に形成されず、十分な発光強度が得られないおそれがある。発光強度は加熱処理の温度が高くなるにつれて増加する傾向にある（詳細は後述）。従って、加熱温度はTa酸化物の融点まで上げることができる。なお、Ta酸化物の融点を超えて加熱すると、カゴ状構造が形成されなくなる。 The heating temperature is 1200 ° C or higher. Below this temperature, the cage structure of the Ta oxide host and the Eu light-emitting source as described above is not formed well, and sufficient light emission intensity may not be obtained. The emission intensity tends to increase as the temperature of the heat treatment increases (details will be described later). Therefore, the heating temperature can be raised to the melting point of Ta oxide. Note that when heating is performed exceeding the melting point of Ta oxide, a cage structure is not formed.
Ta:Euの原子数比に関しては、例えば酸化物としてTa2O5とEu2O3を用いた場合、両者の混合割合を、Ta:Euの原子数比が0.99:0.01〜0.60:0.40の範囲内となるようにする。 Regarding the atomic ratio of Ta: Eu, for example, when Ta 2 O 5 and Eu 2 O 3 are used as oxides, the mixing ratio of the two is such that the atomic ratio of Ta: Eu is 0.99: 0.01 to 0.60: 0.40. Try to be within range.
Ta2O5及びEu2O3に更に別の元素を添加することにより、発光特性を向上させることもできる。例えば、ZnOやZnS、Al2O3を所定量添加し、多元元素化することによって発光色及び励起波長の制御が可能となる。更には、Mg、Gd、Sn、Ti、Tbのいずれか1つ又は複数を加えることによっても、発光色及び励起波長の微調整が可能である。 Luminescent characteristics can be improved by adding another element to Ta 2 O 5 and Eu 2 O 3 . For example, the emission color and the excitation wavelength can be controlled by adding a predetermined amount of ZnO, ZnS, or Al 2 O 3 to form a multielement. Further, the emission color and the excitation wavelength can be finely adjusted by adding one or more of Mg, Gd, Sn, Ti, and Tb.
以下、本願発明者らが行った各種の実験について説明する。まず、粉末のTa2O5とEu2O3を混合し、ペレット状にした後に加熱・焼結処理を行った。以下の実験における基本的な加熱処理条件は特に記載のない限り、次の通りとした：空気中、1気圧、1200℃、2時間。 Hereinafter, various experiments conducted by the inventors will be described. First, powdered Ta 2 O 5 and Eu 2 O 3 were mixed to form a pellet, and then heated and sintered. Unless otherwise stated, the basic heat treatment conditions in the following experiment were as follows: in air, 1 atm, 1200 ° C., 2 hours.
[励起光波長]
Eu添加Ta2O5の励起光波長と、発光強度との関係を調べた。このときのTa2O5とEu2O3の混合モル比は、Ta2O5:Eu2O3=0.92:0.08（原子数比では、Ta:Eu=0.92:0.08）である。図１ａに、発光波長と発光強度との関係を複数の異なる励起波長について表すグラフを示す。図１ａのグラフによれば、励起波長が470nm付近において、608〜615nmの波長範囲（特に611nm）での発光強度が特に強くなることがわかる。なお、611nmの発光ピークにおける半値幅は約3nmとなっており、本発明に係る蛍光体の発光の波長選択性が良好であることが示されている。
[Excitation light wavelength]
The relationship between the excitation light wavelength and emission intensity of Eu-added Ta 2 O 5 was investigated. The mixing molar ratio of Ta 2 O 5 and Eu 2 O 3 at this time is Ta 2 O 5 : Eu 2 O 3 = 0.92: 0.08 (at the atomic ratio, Ta: Eu = 0.92: 0.08). FIG. 1a shows a graph representing the relationship between emission wavelength and emission intensity for a plurality of different excitation wavelengths. According to the graph of FIG. 1a, it can be seen that the emission intensity in the wavelength range of 608 to 615 nm (especially 611 nm) becomes particularly strong when the excitation wavelength is around 470 nm. The half-value width at the emission peak at 611 nm is about 3 nm, which indicates that the wavelength selectivity of light emission of the phosphor according to the present invention is good.
そこで次に、同じ物質について、励起波長を200〜600nmの範囲で連続的に変化させたときに611nmにおける発光強度がどのように変化するかを調べた。その結果を図１ｂに示す。図１ｂには、Taに起因する発光波長である430nmにおける発光強度の結果も併記した。また、Euを添加しない、Ta2O5単独の同様の結果を図１ｃに示す。これらの図より、Eu添加Ta酸化物赤色蛍光体は、460〜480nm(青色域)及び520〜540nm(緑色域)の他、380〜420nm及び290〜340nmの近紫外域でも励起可能であることを示している。 Then, next, it was investigated how the emission intensity at 611 nm changes for the same substance when the excitation wavelength is continuously changed in the range of 200 to 600 nm. The result is shown in FIG. FIG. 1b also shows the result of the emission intensity at 430 nm, which is the emission wavelength caused by Ta. Moreover, the same result of Ta 2 O 5 alone without adding Eu is shown in FIG. From these figures, the Eu-doped Ta oxide red phosphor can be excited in the near ultraviolet region of 380 to 420 nm and 290 to 340 nm in addition to 460 to 480 nm (blue region) and 520 to 540 nm (green region). Is shown.
[Y2O3との比較]
現在、赤色蛍光体として精力的に研究開発が行われているのはEu添加Y2O3である。そこで、本願発明者らは本発明の赤色蛍光体であるEu添加Ta2O5と、Eu添加Y2O3との発光特性の比較を行った。図２に両者の発光強度の比較を表すグラフを示す。励起波長は共に325nmとし、Eu添加Ta2O5におけるTa2O5とEu2O3の比はTa2O5:Eu2O3=0.92:0.08である。Eu添加Ta2O5赤色蛍光体の発光強度(波長611nm)は、Eu添加Y2O3のそれの10倍程度もあることが確認された。
[Comparison with Y 2 O 3 ]
Currently, Eu-added Y 2 O 3 is actively researched and developed as a red phosphor. Therefore, the inventors of the present application compared the light emission characteristics of Eu-added Ta 2 O 5 and Eu-added Y 2 O 3 which are the red phosphors of the present invention. FIG. 2 shows a graph showing a comparison of the emission intensity of the two. Both excitation wavelengths are 325 nm, and the ratio of Ta 2 O 5 and Eu 2 O 3 in Eu-added Ta 2 O 5 is Ta 2 O 5 : Eu 2 O 3 = 0.92: 0.08. It was confirmed that the emission intensity (wavelength 611 nm) of the Eu-added Ta 2 O 5 red phosphor was about 10 times that of Eu-added Y 2 O 3 .
[減衰特性]
また、図３に、本発明に係る赤色蛍光体であるEu添加Ta2O5及びEu添加Y2O3の、一定強度の励起光を連続的に照射した場合の、時間経過による発光強度低下(Fatigue)特性の比較を示す。Ta2O5及びY2O3共に、Eu2O3の添加モル比は0.08である。図３のグラフから明らかなように、本発明のEu添加Ta2O5はEu添加Y2O3と比べて発光の減衰が少なく、安定であることがわかる。
[Attenuation characteristics]
Further, FIG. 3 shows a decrease in emission intensity over time when continuous irradiation of excitation light of a certain intensity of Eu-added Ta 2 O 5 and Eu-added Y 2 O 3 , which are red phosphors according to the present invention. (Fatigue) Comparison of properties. For both Ta 2 O 5 and Y 2 O 3 , the molar ratio of Eu 2 O 3 is 0.08. As is apparent from the graph of FIG. 3, it can be seen that the Eu-added Ta 2 O 5 of the present invention has a lower emission attenuation than the Eu-added Y 2 O 3 and is stable.
[Euの添加量変化による発光強度の変化]
Ta2O5に対してEuの添加量を変化させ、各場合の発光強度を観察した。図４に、Ta2O5に対するEu2O3のモル比を0.0（すなわちTa2O5のみ）、0.01、0.04、0.08、0.15、0.30と変化させた場合の発光波長と発光強度の関係を表すグラフを示す。励起光波長は470nmである。図４のグラフが示す通り、Eu2O3を適切な割合で添加したとき、611nmにおいて鋭い赤色発光が見られることが確認された。また、Eu2O3を全く添加しない場合にはほとんど赤色発光が生じないこともわかった。
[Changes in emission intensity due to changes in the amount of Eu added]
The amount of Eu added to Ta 2 O 5 was changed, and the emission intensity in each case was observed. 4, the molar ratio of Eu 2 O 3 with respect to Ta 2 O 5 0.0 (i.e. Ta 2 O 5 only), the relationship of the emission wavelength and the emission intensity in the case of changing the 0.01,0.04,0.08,0.15,0.30 The graph to represent is shown. The excitation light wavelength is 470 nm. As shown in the graph of FIG. 4, when Eu 2 O 3 was added at an appropriate ratio, it was confirmed that sharp red emission was observed at 611 nm. It was also found that red light emission hardly occurred when no Eu 2 O 3 was added.
Ta2O5に対するEu2O3のモル比の範囲を更に拡大し、0〜0.90の範囲で変化させた場合の611nmにおける発光強度のグラフを図５に示す。図５のグラフに示されているように、原子数比0.005〜0.5において有意な赤色発光が生じ、0.08付近において発光強度が最大となる。Euの割合が大きくなると発光強度が低下する理由は、Ta2O5によるカゴ構造を取りにくくなるためと考えられる。
図２を用いて説明したように、Y2O3と比較するとEu添加Ta2O5赤色蛍光体の最大発光強度はY2O3のそれよりも10倍程度高い。逆に言うと、ピーク強度の数分の一であっても、Eu添加Ta2O5赤色蛍光体は従来の赤色発光体であるY2O3よりも発光強度が高い。従って、図５のグラフにおいて縦軸のピーク強度(約1800)の約1/3の強度(約500)の蛍光を発する範囲である、Euの原子数比0.01〜0.40の範囲において、本発明に係るEu添加Ta2O5赤色蛍光体は従来の赤色発光体であるY2O3よりも十分発光強度が高く、新規且つ高発光強度の赤色蛍光体として使用することができる。なお、図５のグラフによると、その原子数比を0.05〜0.30とすることにより発光強度を1000以上とすることができ、従来物質より数倍も発光強度が高い赤色発光体を得ることができることがわかる。
FIG. 5 shows a graph of the emission intensity at 611 nm when the range of the molar ratio of Eu 2 O 3 to Ta 2 O 5 is further expanded and changed in the range of 0 to 0.90. As shown in the graph of FIG. 5, significant red light emission occurs at an atomic ratio of 0.005 to 0.5, and the light emission intensity becomes maximum near 0.08. The reason why the emission intensity decreases as the Eu ratio increases is thought to be because it is difficult to obtain a cage structure due to Ta 2 O 5 .
As described with reference to FIG. 2, the maximum emission intensity of the Eu-added Ta 2 O 5 red phosphor is about 10 times higher than that of Y 2 O 3 compared to Y 2 O 3 . Conversely, even if it is a fraction of the peak intensity, the Eu-added Ta 2 O 5 red phosphor has higher emission intensity than Y 2 O 3 which is a conventional red light emitter. Therefore, in the graph of FIG. 5, the present invention is applied in the range of the atomic ratio of 0.01 to 0.40, which is the range in which the fluorescence intensity is about 1/3 of the peak intensity (about 1800) on the vertical axis (about 500). Such Eu-added Ta 2 O 5 red phosphor has a sufficiently higher emission intensity than Y 2 O 3 which is a conventional red light emitter, and can be used as a new red phosphor with a high light emission intensity. In addition, according to the graph of FIG. 5, by setting the atomic ratio to 0.05 to 0.30, the emission intensity can be made 1000 or more, and a red luminous body having emission intensity several times higher than that of conventional substances can be obtained. I understand.
[第３元素の効果]
Ta2O5、Euに加え、さらに下に挙げるような第３の元素を添加することで、本発明の発光特性がどのように変化するかを調べた。
Gd、Mn、Sn、Tb、Ce：発光効率において際立った向上効果は見られない。
Zn：発光特性が向上する。
TiO2：発光特性が向上する。
Al2O3：Al2O3はTa2O5と同様、前記のカゴ状構造の一部を構成する。
[Effect of third element]
In addition to Ta 2 O 5 and Eu, it was examined how the emission characteristics of the present invention were changed by adding a third element as listed below.
Gd, Mn, Sn, Tb, Ce: No significant improvement effect in luminous efficiency is observed.
Zn: Emission characteristics are improved.
TiO 2 : Emission characteristics are improved.
Al 2 O 3 : Al 2 O 3 constitutes a part of the cage structure similar to Ta 2 O 5 .
[Zn添加の効果]
図６に、Eu添加Ta2O5（Eu2O3添加量はモル比でTa2O5:Eu2O3=0.92:0.08）と、Zn及びEu添加Ta2O5（Ta2O5:Eu2O3:ZnO=0.84:0.08:0.08）との発光強度の比較を表すグラフを示す。なお、図６のグラフには、参考のために黄色蛍光体であるYAGの発光特性も重ねて表示した。図６のグラフには、Znを添加することにより発光強度が増加することが示されている。
[Effect of Zn addition]
FIG. 6 shows that Eu-added Ta 2 O 5 (Eu 2 O 3 is added in a molar ratio of Ta 2 O 5 : Eu 2 O 3 = 0.92: 0.08) and Zn and Eu-added Ta 2 O 5 (Ta 2 O 5 : Eu 2 O 3 : ZnO = 0.84: 0.08: 0.08) is a graph showing a comparison of light emission intensity. In the graph of FIG. 6, the emission characteristics of YAG, which is a yellow phosphor, are also displayed for reference. The graph of FIG. 6 shows that the emission intensity increases by adding Zn.
図７ａに、Eu添加Ta2O5（Ta2O5:Eu2O3=0.92:0.08）にZnOを添加した場合の、Znの濃度（原子数比）と611nmにおける発光強度との関係を示すグラフを示す。これによれば、Eu添加Ta2O5にZnを僅かでも添加すると、発光特性が向上する効果が得られ、Znの原子数比が0.08である時に、最大の発光強度が得られることがわかる。従って、本発明の赤色蛍光体において有効な発光特性を生じさせるためには、先に述べたEuの添加割合と合わせると、Ta、Eu、Znの原子数比を(1-x-y):x:yと表した場合、x=0.01〜0.3、y=0.005〜0.15程度が好適であると言える。特に、x=0.07〜0.17、y=0.005〜0.05程度のとき、強い発光強度が得られる。
また、図７ｂに、Eu添加Ta2O5（Ta2O5:Eu2O3=0.92:0.08）に添加するZn化合物をZnO及びZnSとした場合の、励起波長が325nmである場合のZn濃度（原子数比）と611nm発光強度の関係を示す。更に、図７ｃに、励起波長が470nmである場合の611nm発光強度の関係を示す。図７ｃからわかるように、いずれの形にせよ、Znを添加することにより発光強度は大きく増加している。また、両グラフより、Znを添加する場合、ZnOの形よりはZnSの形で添加した方が高い発光強度が得られることがわかる。
Fig. 7a shows the relationship between the Zn concentration (atomic ratio) and the emission intensity at 611 nm when ZnO is added to Eu-added Ta 2 O 5 (Ta 2 O 5 : Eu 2 O 3 = 0.92: 0.08). The graph shown is shown. According to this, when Zn is added even slightly to Eu-added Ta 2 O 5 , the effect of improving the light emission characteristics can be obtained, and the maximum light emission intensity can be obtained when the atomic ratio of Zn is 0.08. . Therefore, in order to produce effective emission characteristics in the red phosphor of the present invention, when combined with the above-described addition ratio of Eu, the atomic ratio of Ta, Eu, Zn is (1-xy): x: When y is expressed, it can be said that x = 0.01 to 0.3 and y = 0.005 to 0.15 are preferable. In particular, when x = 0.07 to 0.17 and y = 0.005 to 0.05, strong emission intensity is obtained.
FIG. 7b shows Zn in the case where the excitation wavelength is 325 nm when the Zn compound added to Eu-added Ta 2 O 5 (Ta 2 O 5 : Eu 2 O 3 = 0.92: 0.08) is ZnO and ZnS. The relationship between concentration (atomic ratio) and 611 nm emission intensity is shown. Further, FIG. 7c shows the relationship of the 611 nm emission intensity when the excitation wavelength is 470 nm. As can be seen from FIG. 7c, in any form, the emission intensity is greatly increased by adding Zn. Further, both graphs show that when Zn is added, higher emission intensity is obtained when ZnS is added than with ZnO.
[熱処理温度による発光強度の変化]
熱処理温度によって、本発明の赤色蛍光体の発光特性がどのように変化するかを調べた。図８に、Zn及びEu添加Ta2O5（酸化物の混合モル比でTa2O5:Eu2O3:ZnO＝0.84：0.08：0.08）に対する熱処理温度を変化させた各場合の発光特性を表すグラフを示す。また、図９に、Zn及びEu添加Ta2O5の熱処理温度と発光強度（発光波長は611nm）の関係を表すグラフを示す。図８、図９のグラフにおいて示されている熱処理温度の最小値は1250℃であるが、本願発明者は、1200℃より低い熱処理温度では有意な赤色発光が生じないことを確認している。図８及び図９に示す実験結果から、熱処理温度が高くなるに伴い発光強度が増加し、1450℃でピークとなることがわかる。なお、熱処理温度はTa2O5の融点である1785℃以下とする必要がある。
[Change in emission intensity with heat treatment temperature]
It was examined how the light emission characteristics of the red phosphor of the present invention change depending on the heat treatment temperature. FIG. 8 shows light emission characteristics in each case where the heat treatment temperature was changed for Zn and Eu-added Ta 2 O 5 (the mixing molar ratio of oxide is Ta 2 O 5 : Eu 2 O 3 : ZnO = 0.84: 0.08: 0.08). The graph showing is shown. FIG. 9 is a graph showing the relationship between the heat treatment temperature and emission intensity (emission wavelength is 611 nm) of Zn and Eu-added Ta 2 O 5 . Although the minimum value of the heat treatment temperature shown in the graphs of FIGS. 8 and 9 is 1250 ° C., the present inventor has confirmed that no significant red light emission occurs at a heat treatment temperature lower than 1200 ° C. From the experimental results shown in FIG. 8 and FIG. 9, it can be seen that the emission intensity increases as the heat treatment temperature increases and peaks at 1450 ° C. The heat treatment temperature needs to be 1785 ° C. or lower which is the melting point of Ta 2 O 5 .
［紫外線による励起］
次に、紫外線により励起した場合の本発明の赤色蛍光体の発光特性を調べた。図１０にEu添加Ta2O5（Eu2O3のモル比＝0.08〜0.3）の、図１１にTi及びEu添加Ta2O5（Eu2O3の混合モル比＝0.08、TiO2の混合モル比＝0.01〜0.08）の、それぞれ励起波長325nmの紫外線により励起した場合の発光スペクトルを示す。図６と縦軸のスケールが異なるので直接比較することはできないが、紫外線励起でも611nmにおいて十分な発光が認められる。
[Excitation by ultraviolet rays]
Next, the light emission characteristics of the red phosphor of the present invention when excited by ultraviolet rays were examined. FIG. 10 shows Eu-added Ta 2 O 5 (Eu 2 O 3 molar ratio = 0.08 to 0.3), and FIG. 11 shows Ti and Eu-added Ta 2 O 5 (Eu 2 O 3 mixed molar ratio = 0.08, TiO 2 The emission spectrum when excited by ultraviolet rays having an excitation wavelength of 325 nm, each having a mixing molar ratio of 0.01 to 0.08) is shown. Since the scale of FIG. 6 is different from that of the vertical axis, a direct comparison cannot be made, but sufficient light emission is observed at 611 nm even with ultraviolet excitation.
［Eu添加(Ta・Al)酸化物］
ベース物質であるTa2O5に替え、Ta2O5とAl2O3の混合物をベース物質とした場合のEu添加赤色発光体の特性を調べた。図１２ａ〜図１２ｄは、Ta2O5とAl2O3の混合モル比を1:1、2:3、3:2、3:5と変化させた場合のEu添加赤色発光体の発光スペクトルを示す。いずれも、Eu2O3のモル比は0.08、熱処理温度は1200℃、励起波長は325nmである。全体的にTa2O5のみをベースとした場合よりも発光強度は低下しているが、592nmと618nmの２つの発光ピークが現れる。この混合色はほぼピンク色であり、この発光体はピンク色光源として用いることができる。
[Eu-added (Ta • Al) oxide]
Instead of Ta 2 O 5 as a base material, were characterized in Eu added red emitters in the case of a mixture of Ta 2 O 5 and Al 2 O 3 based material. FIGS. 12a to 12d show emission spectra of Eu-added red light emitters when the mixing molar ratio of Ta 2 O 5 and Al 2 O 3 is changed to 1: 1, 2: 3, 3: 2, and 3: 5. Indicates. In any case, the molar ratio of Eu 2 O 3 is 0.08, the heat treatment temperature is 1200 ° C., and the excitation wavelength is 325 nm. Overall, the emission intensity is lower than when only Ta 2 O 5 is used as a base, but two emission peaks of 592 nm and 618 nm appear. This mixed color is almost pink, and this illuminant can be used as a pink light source.
［焼結助剤］
ベース物質を加熱・焼結する際に、焼結助剤を加えることにより焼結温度を下げることができる。その焼結助剤を添加することによる発光特性への影響を調べた。焼結前の混合物におけるベース物質及び焼結助剤の構成モル比を次に記載する。
Ta2O5: 0.1
Eu2O3: 0.08
K塩(KCl等): 0.053
Na塩(NaCl, Na2CO3, Na2SO4等): 0.767
（なお、焼結助剤であるK塩とNa塩のモル比合計は0.82となるが、重量比では60%以下となる）
上記混合物を800℃で2時間加熱したところ、十分な焼結が行われた。こうして作製した赤色発光体の発光特性を図１３に示す。なお、励起波長は325nmである。図１のグラフと比較すると611nmのピークにおける発光強度の絶対値はやや低下しているが、ピークの鋭さ（半値幅）はそのまま維持されており、赤色発光体の発光特性自体には大きな影響は与えないことがわかる。
[Sintering aid]
When heating and sintering the base material, the sintering temperature can be lowered by adding a sintering aid. The influence on the luminescence properties by adding the sintering aid was investigated. The constituent molar ratios of the base material and the sintering aid in the mixture before sintering are described below.
Ta2O5: 0.1
Eu2O3: 0.08
K salt (KCl etc.): 0.053
Na salt (NaCl, Na2CO3, Na2SO4 etc.): 0.767
(The total molar ratio of K salt and Na salt, which is a sintering aid, is 0.82, but 60% or less by weight)
When the above mixture was heated at 800 ° C. for 2 hours, sufficient sintering was performed. FIG. 13 shows the light emission characteristics of the red light-emitting body thus manufactured. The excitation wavelength is 325 nm. Compared with the graph of FIG. 1, the absolute value of the emission intensity at the peak of 611 nm is slightly reduced, but the sharpness (half-value width) of the peak is maintained as it is, and the emission characteristics of the red light emitter itself are not significantly affected. I understand that I don't give it.
以上、本発明に係る赤色蛍光体について説明を行ったが、上記は例に過ぎず、本発明の精神内で適宜に変更や改良を行っても構わないことは明らかである。 The red phosphor according to the present invention has been described above, but the above is only an example, and it is obvious that changes and improvements may be made as appropriate within the spirit of the present invention.
[構造解析]
図１４に、Ta2O5のみの場合と、それにEu2O3をモル比で0.01〜0.3添加して1200℃で加熱した場合のＸ線回折の結果を示す。これらを比較すると、いずれの場合においてもTa2O5の基本構造がほぼそのまま現れていることがわかる。このことから、Euは、Ta2O5で構成される基本構造の隙間に、イオンとして入り込んでいるのではないかと想定される。
[Structural analysis]
FIG. 14 shows the results of X-ray diffraction when only Ta 2 O 5 is used and when Eu 2 O 3 is added at a molar ratio of 0.01 to 0.3 and heated at 1200 ° C. Comparing these, it can be seen that the basic structure of Ta 2 O 5 appears almost as it is in any case. From this, it is assumed that Eu enters ions in the gap of the basic structure composed of Ta 2 O 5 .
本発明に係る赤色蛍光体は、赤色光源としてはもちろん、青色LED及び黄色蛍光体と組み合わせることにより白色LEDや任意色の光源を構成することができる。このような光源は、照明光源の他、液晶パネル（LCD）のバックライト等にも用いることができる。更に、本発明に係る赤色蛍光体は、紫外線によっても励起するため、紫外線励起照明装置や表示装置の蛍光体としても使用することができる。 The red phosphor according to the present invention can constitute a white LED or a light source of any color by combining with a blue LED and a yellow phosphor as well as a red light source. Such a light source can be used for a backlight of a liquid crystal panel (LCD) in addition to an illumination light source. Furthermore, since the red phosphor according to the present invention is also excited by ultraviolet rays, it can be used as a phosphor for ultraviolet excitation illumination devices and display devices.
Claims (19)
該混合物を1200℃以上、Ta酸化物の溶融温度以下で加熱する工程を有する
ことを特徴とする赤色蛍光体の製造方法。 Ta oxide and Eu oxide are mixed so that the atomic ratio of Ta: Eu is 0.99: 0.01 to 0.60: 0.40,
A method for producing a red phosphor, comprising a step of heating the mixture at a temperature of 1200 ° C. or more and a melting temperature of Ta oxide or less.
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| JP2006271465A JP2008088316A (en) | 2006-10-03 | 2006-10-03 | PHOSPHOR MAINLY COMPOSED OF Ta OXIDE AND ITS MANUFACTURING METHOD |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2009119841A1 (en) | 2008-03-28 | 2009-10-01 | 三菱化学株式会社 | Curable polysiloxane composition, and polysiloxane cured product, optical member, member for aerospace industry, semiconductor light emitting device, lighting system, and image display device using the curable polysiloxane composition |
| KR101072572B1 (en) | 2008-08-08 | 2011-10-11 | 강릉원주대학교산학협력단 | Red phosphor and its forming method for use in solid state lighting |
-
2006
- 2006-10-03 JP JP2006271465A patent/JP2008088316A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2009119841A1 (en) | 2008-03-28 | 2009-10-01 | 三菱化学株式会社 | Curable polysiloxane composition, and polysiloxane cured product, optical member, member for aerospace industry, semiconductor light emitting device, lighting system, and image display device using the curable polysiloxane composition |
| KR101072572B1 (en) | 2008-08-08 | 2011-10-11 | 강릉원주대학교산학협력단 | Red phosphor and its forming method for use in solid state lighting |
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