KR20070111525A - Display apparatus and green phosphor - Google Patents

Abstract

A display apparatus having at least a phosphor layer, characterized in that the phosphor layer contains a green phosphor of beta-alumina structure represented by the general formula: A(Zn1-x-yMgxMny)Al10O17 wherein A is an element selected from among Ca, Ba and Sr; x is a number satisfying the relationship 0.01<=x<=0.3; and y is a number satisfying the relationship 0.02<=x<=0.14.

Description

DISPLAY APPARATUS AND GREEN PHOSPHOR}

The present invention relates to a display device and a green phosphor. More particularly, the present invention relates to a display device such as a plasma display panel (PDP) having a phosphor layer including a green phosphor, and a green phosphor capable of converting irradiated light into light having a lower energy (longer wavelength) than that. .

Phosphors are widely used in various fields. For example, it is used as fluorescent substance for lighting apparatuses, such as a fluorescent lamp, fluorescent substance for display apparatuses, such as a PDP, and fluorescent substance for X-ray imaging tubes. For example, in a color display device, red, blue, and green tricolor phosphors are generally used, and white is obtained by combining fluorescence from these tricolor phosphors. In particular, since the green phosphor is an important phosphor for determining the luminance of white, it is desired to provide a green phosphor that emits high-fluorescence fluorescence with high luminance.

As a conventional green phosphor, (Ba, Mn) Al ₁₂ O ₁₉ , (Y, Tb) BO ₃ , Zn ₂ SiO ₄ : Mn are well known. Further, a blue phosphor albeit, BaMgAl ₁₀ O _17: Eu ^{+ 2} is also known a phosphor represented by (substituting a part of Mg to Ca, Cu, Zn, Pb, Cd, Mg, Sn) (Japanese Patent Laid-Open No. 2002- 173677).

<Start of invention>

Problems to be Solved by the Invention

Among the green phosphors, (Ba, Mn) Al ₁₂ O ₁₉ had high color purity, but had a problem of low luminance. On the other hand, although (Y, Tb) BO ₃ is high brightness, there was a problem of low color purity.

Zn ₂ SiO ₄ : Mn has a better balance of color purity and luminance than the green phosphor, and is often used in display devices such as PDPs.

However, the color purity and luminance of Zn ₂ SiO ₄ : Mn are also insufficient, and further improvement in color purity and luminance has been desired.

Means for solving the problem

In this manner, according to the present invention, there is provided a display device having at least a phosphor layer, wherein the phosphor layer comprises a green phosphor having a beta alumina structure represented by the following formula (1).

A (Zn _{1 -x- y} Mg _x Mn _y ) Al ₁₀ O ₁₇

Here, A represents an element selected from Ca, Ba and Sr, x represents a number satisfying 0.01 ≦ x ≦ 0.3, and y represents a number satisfying 0.02 ≦ x ≦ 0.14.

In addition, according to the present invention, there is provided a green phosphor, represented by the formula (1), characterized in that the β-alumina structure.

<Formula 1>

A (Zn _{1 -x- y} Mg _x Mn _y ) Al ₁₀ O ₁₇

Here, A represents an element selected from Ca, Ba and Sr, x represents a number satisfying 0.01 ≦ x ≦ 0.3, and y represents a number satisfying 0.02 ≦ x ≦ 0.14.

Effect of the Invention

According to the present invention, it is possible to provide a display device including a green phosphor having excellent characteristics such as color purity, brightness, and lifetime, in particular, color purity.

1 is a schematic diagram of β-alumina structure.

2 is a schematic perspective view of the PDP.

FIG. 3 is a graph showing the Mg substitution amount dependency of the amount of emitted light of the phosphor of Example 1. FIG.

4 is a graph showing the relationship between the lighting time and the peak intensity in Example 3. FIG.

<Brief description of symbols for the main parts of the drawings>

11, 21: substrate

17, 27: dielectric layer

18: protective layer

28: phosphor layer

29: bulkhead

30: space

41: transparent electrode

42: bus electrode

100: PDP

A: address electrode

Best Mode for Carrying Out the Invention

First, the display device of the present invention is a display device having at least a phosphor layer, and the phosphor layer includes a green phosphor having a beta alumina structure represented by the following formula (1). In addition, x and y mean molar ratio (atomic ratio).

<Formula 1>

A (Zn _{1 -x- y} Mg _x Mn _y ) Al ₁₀ O ₁₇

Here, A represents an element selected from Ca, Ba and Sr, x represents a number satisfying 0.01 ≦ x ≦ 0.3, and y represents a number satisfying 0.02 ≦ x ≦ 0.14.

In the above formula, A may be any one of Ca, Ba, or Sr, and may include two or both of these elements. Specifically, a combination of Ca / Ba, Ca / Sr, Ba / Sr, and Ca / Ba / Sr is mentioned.

When x is smaller than 0.01 or larger than 0.3, it is not preferable because the improvement in luminance is insufficient. More preferable x is 0.05-0.2.

When y is smaller than 0.02 or larger than 0.14, the improvement in luminance is insufficient, which is not preferable. More preferred y is in the range of 0.03 to 0.10.

Subsequently, the green phosphor in which A includes both Ba and Sr may be represented by the following Chemical Formula 2.

(Ba _{1 - z} Sr _z ) (Zn _{1 -x- y} Mg _x Mn _y ) Al ₁₀ O ₁₇

Where x and y are the same as above and z represents a number satisfying 0 <z <1.

In the case of the green phosphor including both Ba and Sr, when x is in the range of 0.01 to 0.07 and z is in the range of 0.001 to 0.999, a green phosphor having high luminance and color purity is obtained.

Also, the green phosphor may be a mixed crystal of another base material, such as AZnAl ₁₀ a O ₁₇ as base material and, although the Mn and Mg as the emission center, CaAl ₁₂ O on a base material _19, SrAl ₁₂ O ₁₉ to the appropriate ratio.

The green phosphor was found to have a large number of green phosphors showing high brightness and high color purity when the base material had the β-alumina structure shown in FIG. 1.

The wavelength of light irradiated to extract green fluorescence from the green phosphor is not particularly limited, but in the case of a display device such as a plasma display panel (PDP), the wavelength of a vacuum ultraviolet region (for example, 147 nm or 172 nm) Is preferable.

Moreover, you may mix the following other green fluorescent substance with the said green fluorescent substance.

(1) A green phosphor having a magnetoplumbite-type crystal structure containing at least Mn, La, and Tb.

(2) A green fluorescent substance having a magnetoplumbite-type crystal structure containing at least Tb and La and not containing Ce.

(3) A green phosphor having a magnetoplumbite-type crystal structure containing at least Mn, La, and Zn.

These other green phosphors often have higher luminance than the green phosphors, and by mixing with the green phosphors, both color purity and luminance can be further improved.

As a specific example of another green phosphor,

LaMgAl ₁₁ O ₁₉ : Mn, Tb, La _x Al _y O _z (x: y: z = 0.5 to 1.2: 11 to 12:18 to 19.5) and the like (1)

(2) LaMgAl ₁₁ O ₁₉ : Tb, LaMgAl ₁₁ O ₁₉ : Mn, Tb and the like

_{(- x Tb x La 1)} y (Mg 1 -a- b Mn a Zn b) Al z O 1 .5 (z + y) +1 ( _{wherein, 0≤ (3) LaMgAl 11 O} 19, for x≤0.5, 0.8≤y≤1.2, 0 <a + b≤1, 8≤z≤30), etc.

Can be mentioned.

The green phosphor can be formed by a known method. For example, a compound containing A, Zn, Mn, and Al is weighed to a desired molar ratio. These compounds are calcined. Subsequently, by pulverizing and classifying the sintered compact of the obtained green fluorescent substance, the green fluorescent substance of a predetermined particle diameter can be obtained.

Specifically, it is preferable to bake in a nitrogen atmosphere for 1 to 10 hours at baking temperature 1300-1700 degreeC. Further, a reaction accelerator comprising a halide such as _{AlF 2, MgF 2, LiF,} NaF in order to lower the sintering temperature may be used in a range which does not interfere with the effectiveness of the present invention.

In addition, other green phosphors can be formed in accordance with the green phosphors.

Examples of the display device of the present invention include a PDP, a CRT, a fluorescent display tube, an X-ray imaging tube, and the like. Hereinafter, the PDP of FIG. 2 will be described as an example of the display device of the present invention.

2 is a three-electrode AC type surface discharge PDP. In addition, this invention is not limited to this PDP, It can apply to any structure as long as it is a PDP containing a green fluorescent substance. For example, the present invention is not limited to the AC type, but may be used for the PDP of either the DC type or the reflective or transmissive type.

The PDP 100 of FIG. 2 is composed of a front substrate and a back substrate.

First, the front substrate generally includes a plurality of display electrodes formed on the substrate 11, a dielectric layer 17 formed to cover the display electrodes, and a protective layer 18 formed on the dielectric layer 17 and exposed to the discharge space. .

The board | substrate 11 is not specifically limited, A glass substrate, a quartz glass substrate, a silicon substrate, etc. are mentioned.

The display electrode is made of a transparent electrode 41 such as ITO. In addition, in order to lower the resistance of the display electrode, a bus electrode (for example, a three-layer structure of Cr / Cu / Cr) 42 may be formed on the transparent electrode 41.

The dielectric layer 17 is formed of a material commonly used for PDPs. Specifically, it can form by apply | coating the paste which consists of low melting glass and a binder on a board | substrate, and baking.

The protective layer 18 is provided to protect the dielectric layer 17 from damage caused by collision of ions generated by discharge during display. The protective layer 18 consists of MgO, CaO, SrO, BaO, etc., for example.

Subsequently, the back substrate is generally disposed on the dielectric layer 27 between a plurality of address electrodes A formed on the substrate 21 in a direction crossing the display electrodes, a dielectric layer 27 covering the address electrodes A, and adjacent address electrodes A. The phosphor layer 28 includes a plurality of stripe-shaped partition walls 29 and partition walls 29 formed between the partition walls 29.

As the substrate 21 and the dielectric layer 27, the same type as the substrate 11 and the dielectric layer 17 constituting the front substrate can be used.

The address electrode A consists of metal layers, such as Al, Cr, Cu, etc., and a 3-layered structure of Cr / Cu / Cr, for example.

The partition 29 can be formed by applying a paste made of low melting glass and a binder onto the dielectric layer 27 and drying it, and then cutting it by sandblasting. Moreover, when photosensitive resin is used for a binder, it can also form by baking, after exposing and developing using a mask of a predetermined shape.

In FIG. 2, the phosphor layer 28 is formed between the partition walls 29, but the green phosphor can be used as a raw material of the phosphor layer 28. The formation method of the phosphor layer 28 is not specifically limited, A well-known method is mentioned. For example, the phosphor layer 28 can be formed by apply | coating the paste which disperse | distributed fluorescent substance to the solution in which the binder melt | dissolved in the solvent between partition walls 29, and baking in air atmosphere.

Subsequently, the front substrate and the rear substrate are opposed to each other with the electrodes inward so that the display electrodes 41 and 42 and the address electrode A are perpendicular to each other, and the discharge gas is filled in the space 30 surrounded by the partition walls 29 to thereby provide a PDP. 100 can be formed.

In the PDP, a phosphor layer is formed on the barrier rib and the dielectric layer on the rear substrate side among the barrier rib, the dielectric layer and the protective film defining the discharge space, but the phosphor layer may also be formed on the protective film on the front substrate side by the same method. have.

Hereinafter, the Example of this invention is described. In addition, this invention is not limited to a following example.

<Example 1>

An appropriate amount of ethanol was added to the following molar ratio of raw materials and mixed for 3 hours.

The mixture is baked for 4 hours at 1300 ℃ under nitrogen atmosphere, and by milling the obtained sintered body Ba (Zn _x Mg _{x 0 .97- 0 .03} Mn) Al ₁₀ O ₁₇ phosphor represented by (0≤x≤0.3) a To d were prepared. It was confirmed by X-ray diffraction that the obtained phosphor was a crystal having a beta alumina structure.

The light emission amounts of the phosphors a to d are measured, and the light emission amount is shown in FIG. 3 as a ratio when the light emission amount of (Zn, Mn) ₂ SiO ₄ is 1. In addition, the chromaticity coordinates (x, y) of each phosphor are shown in Table 2 together with the amount of emitted light.

It can be seen from FIG. 3 that a green phosphor having high luminance and high color purity is obtained when the amount of Mg added is in the range of 0.01 to 0.3.

<Example 2>

Phosphor e was prepared in the same manner as in Example 1 using the molar ratio raw material shown in Table 3.

It was 1.41 when the light emission amount of the fluorescent substance e was measured and converted as a ratio when the light emission amount of (Zn, Mn) ₂ SiO ₄ was 1. In addition, chromaticity coordinate x was 0.118 and chromaticity coordinate y was 0.748.

It can be seen that the phosphor e containing Sr can further increase the amount of emitted light.

<Example 3>

C phosphor using _{[(Ba 0 .7 Sr 0 .3} ) (Zn 0 .94 Mg 0 .03 Mn 0 .03) Al 10 O 17] , and BAM was prepared a PDP having the following configuration.

PDP consists of:

Display electrode Transparent electrode 280 µm wide, bus electrode 100 µm wide

100 µm discharge gap between display electrodes

30 μm thick dielectric layer

100 μm in height of bulkhead

Array pitch of bulkhead 360 ㎛

Ne-Xe (5%) discharge gas

Gas Pressure 500 Torr

The obtained PDP was turned on continuously for 500 hours as an accelerated life test, and the peak intensity was measured for every lighting time. The obtained peak intensity is shown in FIG. 4 as a relative peak intensity when the peak intensity at the start of lighting is set to 1. FIG.

It can be seen from FIG. 4 that phosphor c has a longer lifetime than BAM.

By using the fluorescent substance of the present invention excellent in characteristics such as color purity, luminance and lifespan, in particular, color purity, display characteristics of display devices such as PDP, CRT, fluorescent display tubes, and X-ray imaging tubes can be improved.

Claims (4)

A display device having at least a phosphor layer, wherein the phosphor layer comprises a green phosphor having a beta alumina structure represented by the following formula (1). <Formula 1> A (Zn _{1 -x- y} Mg _x Mn _y ) Al ₁₀ O ₁₇ (Where A represents an element selected from Ca, Ba and Sr, x represents a number satisfying 0.01 ≦ x ≦ 0.3, and y represents a number satisfying 0.02 ≦ x ≦ 0.14). The display device of claim 1, wherein the phosphor is represented by Formula 2 below. <Formula 2> (Ba _{1 - z} Sr _z ) (Zn _{1 -x- y} Mg _x Mn _y ) Al ₁₀ O ₁₇ (Where x and y are the same as above and z represents a number satisfying 0 <z <1). The display device of claim 1, wherein the phosphor emits green fluorescence by irradiation with vacuum ultraviolet rays. The green phosphor represented by the following Chemical Formula 1 and having a beta alumina structure. <Formula 1> A (Zn _{1 -x- y} Mg _x Mn _y ) Al ₁₀ O ₁₇ (Where A represents an element selected from Ca, Ba and Sr, x represents a number satisfying 0.01 ≦ x ≦ 0.3, and y represents a number satisfying 0.02 ≦ x ≦ 0.14).

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