KR20070113301A - Fluorescent substance and electron beam excited light emitting element - Google Patents

Abstract

A fluorescent substance and an electron beam excited light emitting element. The fluorescent substance comprises a compound represented by the formula (I) below and, as an activator, at least one element selected from the group consisting of Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Mn: M1O.mM2O.nM3 O2 (I) wherein M1 represents at least two elements selected from the group consisting of Ca, Sr and Ba, or Sr alone or Ba alone; M2 represents at least one element selected from the group consisting of Mg and Zn; M3 represents a least one element selected from the group consisting of Si, Ge and Zr; and m satisfies the requirement: 0.8<=m<=1.2; and n satisfies the requirement: 1.6<=n<=2.4. The electron beam excited light emitting element comprises the fluorescent substance.

Description

Phosphor and electron beam excited light emitting element {FLUORESCENT SUBSTANCE AND ELECTRON BEAM EXCITED LIGHT EMITTING ELEMENT}

The present invention relates to a phosphor and an electron beam excited light emitting element.

In recent years, field emission displays (FEDs) and surface electric field displays (SEDs) have been attracting attention as light emitting devices and have been developed. These light emitting elements consist of a phosphor and an electron beam excitation source which excites and emits light. As phosphors that emit light under electron beam irradiation, for example CaMgSi ₂ O ₆ : Eu is known (Extended Abstract of the Fifth International Conference on the Science and Technology of Display Phosphors. 1999, p.317-p.320).

However, from the viewpoint of improving the performance of the light emitting device, a phosphor of high brightness has been required.

Disclosure of the Invention

An object of the present invention is to provide a phosphor exhibiting high luminance under electron beam irradiation and an electron beam excited light emitting element using the same.

MEANS TO SOLVE THE PROBLEM As a result of earnestly researching about fluorescent substance, this inventor came to complete this invention.

That is, the present invention is a compound represented by the formula (I) and Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Mn as a activator Provided is a phosphor containing at least one selected from the group consisting of.

M ¹ OmM ² O nM ³ O ₂ (I)

(M ¹ Is at least two selected from the group consisting of Ca, Sr and Ba, Sr alone or Ba alone,

M ² Is at least one selected from the group consisting of Mg and Zn,

M ³ Silver is at least one selected from the group consisting of Si, Ge and Zr,

m is 0.8 or more and 1.2 or less,

n is 1.6 or more and 2.4 or less.]

Moreover, this invention provides the electron beam excitation light emitting element containing said fluorescent substance and an electron emission part.

Implement the invention  Form for

Phosphor

The phosphor of the present invention contains a compound represented by the formula (I) and an activator.

In formula (I), M ¹ is a divalent metal element such as calcium (Ca), strontium (Sr) or barium (Ba), and any one of Sr and Ba; A combination of Ca and Sr, a combination of Ca and Ba, and a combination of Sr and Ba; It is a combination of Ca, Sr, and Ba.

M ² is a divalent metal element such as magnesium (Mg) or zinc (Zn), and any one of Mg and Zn; It is a combination of Mg and Zn, Preferably it is Mg or the combination of Mg and Zn, More preferably, it is Mg.

M ³ is a tetravalent metal element such as silicon (Si), germanium (Ge), zirconium (Zr), and any one of Si, Ge, and Zr; A combination of Si and Ge, a combination of Si and Zr, and a combination of Ge and Zr; It is a combination of Si, Ge, Zr, Preferably it is Si, the combination of Si and Ge, the combination of Si and Zr, or the combination of Si, Ge, Zr, More preferably, it is Si.

In formula (I), m is 0.8 or more and 1.2 or less, and n is 1.6 or more and 2.4 or less.

The activator is cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), tulium (Tm), ytterbium (Yb), manganese (Mn), and preferably Eu. The activator may be any of these alone or in combination.

The phosphor may further contain other metal elements such as monovalent metal elements and trivalent metal elements. Other metal elements include, for example, lithium (Li), sodium (Na), potassium (K), rubidium (Rb), iron (Fe), indium (In), lanthanum (La), lutetium (Lu), bismuth (Bi), antimony (Sb). These may be individual or a combination.

It is preferable that a fluorescent substance is a compound represented by Formula (II).

(M ¹ _{1 - a} Eu _a ) M ² M ³ ₂ O ₆ (II)

Equation (Ⅱ) of, M ^1, M ² and M ³ are, respectively, of the formula (I) M ^1, M ² and M ³ And a is greater than 0, preferably 0.003 or more, and less than 0.3, preferably 0.2 or less.

Furthermore, it is preferable that a fluorescent substance is a compound represented by Formula (III).

Ca _{1 -b- c} Sr _b Eu _c MgSi ₂ O ₆ (III)

b is more than 0.7, preferably 0.75 or more, more preferably 0.8 or more, less than 1, preferably 0.98 or less, c is more than 0, preferably 0.003 or more, less than 0.3, preferably 0.2 It is as follows. In addition, the sum of b and c exceeds 0.7 and is one or less.

In addition, it is preferable that the phosphor has a crystal structure of the same type as the diopside {tupitite}. The phosphor satisfies the above composition and is excited under electron beam irradiation to emit visible light. Phosphors, such _{as, Sr 0 .98 Eu 0 .02 MgSi} 2 O 6, Sr 0 .72 Eu 0 .28 MgSi 2 O 6, Ba 0.98 Eu 0.02 MgSi 2 O 6, Ba 0 .72 Eu 0 .28 _{MgSi 2 O 6, .2 Ca 0} .26 Sr 0 .72 Eu 0 .02 MgSi 2 O 6, Ca 0 .08 Sr 0 .72 Eu 0 is a compound represented by the MgSi ₂ O _6. The electron beam that is the excitation source of the phosphor is, for example, a low speed electron beam (acceleration voltage: about 0.001 kV to about 10 kV), a high speed electron beam (acceleration voltage: about 20 kV to about 30 kV), and preferably a low speed electron beam. Therefore, the phosphor is used for electron beam excitation light emitting devices such as FED and SED whose excitation source is a low speed electron beam, and CRT and VFD which are high speed electron beams, preferably FED and SED.

What is necessary is just to manufacture the fluorescent substance of this invention by baking the mixture of the compound represented by Formula (I) and the metal compound used as a fluorescent substance containing the said activator by baking, For example, the metal compound is weighed. By doing so, a mixture satisfying the molar ratio of the metal elements in the phosphor may be obtained, and then the mixture may be calcined.

Metal compounds are calcium, strontium, barium, magnesium, zinc, silicon, germanium, zirconium, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, tulium, ytterbium, manganese For example, an oxide or hydroxide, carbonate, nitrate, halide, oxalate which decomposes or becomes an oxide at high temperature may be sufficient. Instead of adding a halide as a flux as described later, a metal halide, more preferably a metal fluoride and a metal chloride may be used as the metal compound.

Phosphor comprising a compound represented by _{Sr 0 .98 Eu 0 .02 MgSi 2} O 6 _{is, SrCO 3, Eu 2 O 3} , MgO, and weighing the SiO ₂ Sr: Eu: Mg: Si molar ratio of 0.98: 0.02: 1: 2 and the mixture obtained, is obtained by sintering the mixture, Ba Eu _{0 .98 0 .02} MgSi ₂ O ₆ The phosphor composed of the compound represented by the above weighs BaCO ₃ , Eu ₂ O ₉ , MgO, SiO ₂ to obtain a mixture having a molar ratio of Ba: Eu: Mg: Si of 0.98: 0.02: 1: 2, and calcining the mixture. It is obtained by, besides _{Ca 0 .26 Sr 0 .72 Eu 0} .02 MgSi phosphor comprising a compound represented by the ₂ O ₆ is, CaCO _3, SrCO _3, Eu ₂ O _3, MgO, SiO ₂ were weighed to Ca It is obtained by obtaining the mixture whose molar ratio of: Sr: Eu: Mg: Si is 0.26: 0.72: 0.02: 1: 1 and baking the mixture.

Mixing may be performed using apparatuses, such as a ball mill, a V-type mixer, and a stirrer, for example. When the mixture of metal compounds contains hydroxides, carbonates, nitrates, halides, and oxalates of metals that are decomposed or oxidized at high temperatures to become oxides, the mixture may be prebaked before firing. Preliminary baking may be performed at the temperature of about 400 degreeC or more and less than about 1000 degreeC, and you may grind | mix the prebaked mixture.

Baking may be performed under the following conditions, for example.

Temperature: about 1000 ° C. or higher, preferably about 1100 ° C. or higher, about 1500 ° C. or lower, preferably about 1200 ° C. or lower,

Holding time: 0.3 hours or more, 100 hours or less

Atmosphere: Reducible gases, such as nitrogen containing 0.1-10 volume% of hydrogen, and argon containing 0.1-10 volume% of hydrogen.

In this manufacturing method, you may add carbon to the mixture of a metal compound before baking. By adding carbon, firing is further performed in a strong reducing atmosphere. Further, before firing, the flux may be added to the mixture of the metal compounds. By adding the flux, a highly crystalline phosphor or a phosphor having a large average particle diameter can be obtained. The flux is, for example, LiF, NaF, KF, LiCl, NaCl, KCl, Li ₂ CO ₃ , Na ₂ CO ₃ , K ₂ CO ₃ , NaHCO ₃ , NH ₄ Cl, NH ₄ I. Although baking may be normally performed once, you may carry out twice or more.

The phosphor may be pulverized, washed or classified. What is necessary is just to perform grinding | pulverization and classification by the apparatus which can adjust the particle size of fluorescent substance, For example, grinding | pulverization may be performed by a ball mill and a jet mill, and classification may be performed by a sieve and a cyclone.

Electron beam excitation light emitting device

The electron beam-excited light emitting device of the present invention contains the above-mentioned phosphor, and usually includes a phosphor and an electron emitting portion. The electron emission unit emits an electron beam that excites the phosphor to emit light, and is, for example, an electron gun and a planar electron emission source (emitter).

The electron beam excited light emitting element is, for example, FED, SED, CRT, VFD, preferably FED, SED.

What is necessary is just to manufacture FED by the method containing process (i)-(i), for example as described in Unexamined-Japanese-Patent No. 2002-138279.

(i) a process of preparing each liquid by dispersing the phosphor in a solvent (for example, an aqueous polyvinyl alcohol solution) for the blue phosphor, the green phosphor, and the red phosphor;

(Ii) process of apply | coating and drying each liquid on a glass substrate, forming a phosphor layer, respectively, and manufacturing a faceplate,

(Iii) a step of assembling a face plate and a rear plate having a plurality of electron emission portions through a support frame;

(Iv) vacuum-sealing the gap between the face plate and the rear plate.

A blue fluorescent substance is a fluorescent substance containing the compound represented by Formula (I) and the said activator, and you may combine another blue fluorescent substance as needed. Other blue phosphors are, for example, zinc sulfide phosphors (ZnS: Ag, Cu, Au, Al). The green phosphor is, for example, zinc sulfide phosphor (ZnS: Cu, Au, Al), and the red phosphor is, for example, yttrium oxide phosphor (Y ₂ O ₃ : Eu), yttrium sulfide phosphor (Y ₂ O ₂ S: Eu).

What is necessary is just to manufacture SED similarly to FED, for example, the method disclosed by Paragraph No. 0182-0189 of Unexamined-Japanese-Patent No. 2002-83537 (on the rear plate, in which the some surface conduction type electron emission element was formed, The substrate is fixed, a face plate composed of a glass substrate, a phosphor layer formed on the inner surface thereof, and a metal back is disposed through a support frame, and flit glass is applied to these joints and fired in the air. After the coating, the air gap is evacuated and sealed. In the case of displaying the monochrome, a phosphor containing the compound represented by the formula (I) and the activator is used, and in the case of color display, a black stripe is formed and the phosphor is contained in the gap. Phosphors of each color are applied to form a phosphor layer, and a black stripe or a black matrix is obtained.

In addition, CRT and VFD may be manufactured by a well-known manufacturing method using said fluorescent substance.

Although an Example demonstrates this invention in more detail, this invention is not limited to these Examples.

The luminance was accelerated by an acceleration voltage of 10 kV, and the fluorescent substance was measured by irradiating an electron beam having a cross-sectional area of 1 μA / cm 2. Chromaticity x and chromaticity y were calculated according to the XYZ color system of the CIE color system defined by CIE (Commission Internationale de l'Eclairage).

Reference Example  One

Calcium Carbonate (CaCO ₃ , manufactured by Ube Materials Co., Ltd., product name: ultra-high purity calcium carbonate CS · 3N-A), Europium oxide (Eu ₂ O ₃ , manufactured by Shin-Etsu Chemical Co., Ltd.), magnesium carbonate (MgO content: 42.0%, prepared by Kyowa chemical industry Co., Ltd., trade name: High purity magnesium carbonate), silica (SiO _2, manufactured by Nippon Oh Co., Ltd., trade name be in the: were weighed, mixed AEROSIL200), Ca: Eu: Mg: the molar ratio of Si 0.992: 0.008: 1: 2 mixture obtained, the mixture was 2 vol% H ₂ containing N ₂ It baked at 1220 degreeC under atmosphere. The firing is conducted three times in total, formula _{Ca 0 .992 Eu 0 .008 MgSi 2} O 6 to obtain a fluorescent material (1) containing a compound represented by.

The phosphor 1 emitted blue light under electron beam irradiation. Table 1 shows the measurement results of luminance, chromaticity x and chromaticity y. In the present example, the luminance of the phosphor 1 was set to 100. Moreover, when the crystal structure was examined by the X-ray diffraction apparatus, the fluorescent substance 1 had the same crystal structure as the diopside.

Example  One

Strontium Carbonate (SrCO ₃ , manufactured by Sakai Chemical Co., Ltd., trade name: High Purity Strontium Carbonate SW-K), Europium Oxide (Eu ₂ O ₃ , Shin-Etsu Chemical Co., Ltd.), Magnesium Carbonate (Mg0 Content: 42.0%, Kyowa Chemical Industries, Ltd.) Co., Ltd., product name: high-purity magnesium carbonate) and silicon dioxide (SiO ₂ , manufactured by Nippon Aerosil Co., Ltd., product name: AEROSIL200) were weighed and mixed to obtain a molar ratio of Sr: Eu: Mg: Si of 0.98: 0.02: 1: 2 A phosphorus mixture was obtained. The mixture to 2 volume% H ₂ N ₂ It baked at 1150 degreeC in atmosphere, for 2 hours. The firing is carried out in total 3 times formula _{Sr 0 .98 Eu 0 .02 MgSi 2} O 6 to phosphor (2) was obtained consisting of compounds represented by.

The phosphor 2 emitted blue light under electron beam irradiation. Table 1 shows the measurement results of luminance, chromaticity x and chromaticity y. Phosphor 2 had the same crystal structure as diopside.

Phosphor Composition and Luminescence Characteristics Furtherance Luminance Chromaticity x y Reference Example 1 Phosphor 1 _{Ca 0 .992 Eu 0 .008 MgSi 2} O 6 100 0.155 0.045 Example 1 Phosphor 2 _{Sr 0 .98 Eu 0 .02 MgSi 2} O 6 112 0.158 0.035

The phosphor of the present invention is excited under electron beam irradiation to emit high luminance light. The phosphor is preferably used for electron beam excited light emitting devices such as FED and SED.

Claims (9)

The compound represented by formula (I) and selected from the group consisting of Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Mn as activators; Phosphor containing at least one. M ¹ OmM ² OnM ³ O ₂ (I) (M ¹ Is at least two selected from the group consisting of Ca, Sr and Ba, Sr alone or Ba alone, M ² Is at least one selected from the group consisting of Mg and Zn, M ³ Silver is at least one selected from the group consisting of Si, Ge and Zr, 0.8 ≤ m ≤ 1.2, 1.6 ≤ n ≤ 2.4] The method of claim 1, Phosphor containing the compound represented by Formula (II). (M ¹ _1-a Eu _a ) M ² M ³ ₂ O ₆ (II) (M ¹ Is at least two selected from the group consisting of Ca, Sr and Ba, Sr alone or Ba alone, M ² Is at least one selected from the group consisting of Mg and Zn, M ³ At least one selected from the group consisting of Si, Ge and Zr. 0 <a <0.3 The method of claim 1, Phosphor containing the compound represented by Formula (III). Ca _{1 -b- c} Sr _b Eu _c MgSi ₂ O ₆ (III) (0.7 <b <1, 0 <c <0.3 0.7 <b + c ≤ 1] The method of claim 1, The phosphor has the same crystal structure as the diopside. The electron beam excitation light emitting element containing the fluorescent substance in any one of Claims 1-4. The method of claim 5, Further, an electron beam excited light emitting device comprising an electron emitting portion. The method of claim 5, Electron beam excitation light emitting device selected from FED, SED, CRT, VFD. The method of claim 7, wherein An electron beam excited light emitting element selected from FED and SED. Use as an electron beam excitation light emitting element of the fluorescent substance in any one of Claims 1-4.