KR20080007977A - A phosphor and a plasma display panel employing a phosphor layer comprising the same - Google Patents

Abstract

A blue phosphor, and a plasma display panel(PDP) containing a phosphor layer comprising the phosphor are provided to improve heat resistance, durability, lifetime characteristics, brightness characteristics and color purity. A blue phosphor comprises a phosphor represented by (Ba_(1-x-y)) Sr_y Mg_p Al_q O_r:Eu_x and a CMS-based phosphor, wherein 0.001<=x<=0.1; 0.021<=y<=0.3; and p=1, q=10 and r=17 or p=1, q=14 and r=23. Preferably the mixing ratio of the two phosphors is 1:1 by weight; and the CMS-based phosphor is at least one selected from the group consisting of CaMgSi2O6:Eu, Ca3MgSi2O6:Eu and Ca2MgSiO4:Eu.

Description

A phosphor and a plasma display panel employing a phosphor layer comprising the same

1 is an exploded perspective view of a plasma display panel according to an embodiment of the present invention.

2 is a schematic partial cross-sectional view of a plasma display panel according to another embodiment of the present invention.

3 is a schematic partial cross-sectional view of a plasma display panel according to another embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

100: plasma display panel 111: first substrate

112: sustain electrode pair 113: common sustain electrode (X electrode)

114: scanning sustain electrode (Y electrode) 115: first dielectric layer

116: protective layer 121: second substrate

122: address electrode 125: second dielectric layer

126: phosphor 130: partition wall

140: discharge cell

The present invention relates to a plasma display panel including a phosphor and a phosphor layer including the same, and more particularly, to a plasma display panel including a phosphor having excellent heat resistance, durability, lifetime characteristics, luminance characteristics, and color purity, and a phosphor layer including the same. It is about.

Phosphor is a material that emits light by energy stimulation, and is generally used in light sources such as mercury fluorescent lamps and mercury free fluorescent lamps, and various devices such as electron emitting devices and plasma display panels. It is expected to be used for this purpose.

Such phosphors should be selected to be able to absorb and excite excitation light generated in the wavelength range generated from the device, and should preferably have properties such as current saturation characteristics, deterioration characteristics, luminescence characteristics, color purity, and the like suitable for each application.

In the case of a plasma display panel, phosphors are excited by excitation light in a vacuum ultraviolet (VUV) wavelength band of 147 nm to 200 nm. As a blue phosphor among phosphors for a plasma display panel, for example, US Pat. No. 6,667,574 discloses a BAM (Ba _1-x MgAl ₁₀ O ₁₇ : Eu _x, 0.03 ≦ _x ≦ 0.25) phosphor.

However, since the initial luminance of the phosphor is improved as the substitution amount of Eu ²⁺ in the conventional blue phosphor is increased, the deterioration tendency of the phosphor is more severe, and thus the heat resistance of the phosphor tends to be improved as the substitution amount of Eu ²⁺ is decreased. .

As such, the heat resistance, durability, lifetime characteristics, luminance, and color purity of the conventional blue phosphors are in a trade-off relationship. Therefore, it is urgent to develop blue phosphors in which all of them are improved at the same time.

An object of the present invention is to provide a plasma display panel including a phosphor having excellent heat resistance, durability, lifespan characteristics, luminance characteristics and color purity, and a fluorescent layer including the same, in order to solve the problems as described above.

In order to achieve the above object, the present invention provides a blue phosphor including a phosphor having the formula (1) and a phosphor of the CMS series.

<Formula 1>

Ba _1-xy Sr _y Mg _p Al _q O _r : Eu _x ,

In Formula 1,

 0.001 ≦ x ≦ 0.1 and 0.021 ≦ y ≦ 0.3; p = 1, q = 10, r = 17, or p = 1, q = 14, r = 23.

On the other hand, the phosphor having Formula 1 may have a formula Ba _0.65 Sr _0.25 MgAl ₁₀ O ₁₇ : Eu _0.1 , Ba _0.69 Sr _0.21 MgAl ₁₀ O ₁₇ : Eu _0.1, Ba _0.6 Sr _0.3 MgAl ₁₀ O ₁₇ : Eu _0.1 .

In addition, the CMS-based phosphor may be at least one selected from the group consisting of CaMgSi ₂ O ₆ : Eu, Ca ₃ MgSi ₂ O ₈ : Eu and Ca ₂ MgSiO ₄ : Eu, and the phosphor having Formula 1 The weight ratio of the CMS-based phosphor may be 1: 1.

In order to achieve the above object, the present invention provides a plasma display panel having a phosphor layer including the phosphor.

The plasma display panel may include: a first substrate and a second substrate spaced apart from each other, and partition walls partitioning a space between the first substrate and the second substrate into a plurality of discharge cells; A plurality of electrodes arranged around the discharge cells to cause discharge; And a red phosphor layer, a green phosphor layer, and a blue phosphor layer applied to bottom surfaces of the discharge cells and side surfaces of the partition walls.

In addition, the present invention is a plasma display, characterized in that the blue phosphor layer coated on the side wall of the discharge cell is coated with a CMS-based phosphor layer outside the Ba _1-xy Sr _y Mg _p Al _q O _r : Eu _x phosphor layer. Provide a panel.

In addition, the present invention provides a plasma display panel having a thickness of 1 to 40 μm of a CMS-based blue phosphor layer applied to the Ba _1-xy Sr _y Mg _p Al _q O _r : Eu _x phosphor layer.

In addition, the present invention provides a plasma display panel, wherein the blue phosphor layer coated on the side wall of the discharge cell is a single layer of the CMS-based blue phosphor layer, and the CMS-based blue phosphor layer coated on the side wall of the discharge cell. The thickness of may be 1 to 50㎛.

Hereinafter, the present invention will be described in detail.

The phosphor according to the present invention is a blue phosphor including a phosphor having the following Chemical Formula 1 and a phosphor of CMS series.

<Formula 1>

Ba _1-xy Sr _y Mg _p Al _q O _r : Eu _x

In the formula (1), x representing the molar ratio of Eu as the activator is 0.001 ≦ x ≦ 0.1.

If x is less than 0.001, there may be a problem that the phosphor brightness is lowered and the efficiency is lowered. If x is greater than 0.1, there may be a problem of deterioration during panel formation.

In the formula (1), y representing the molar ratio of Sr is 0.021 ≦ y ≦ 0.3. If y is less than 0.21, Sr may not be properly substituted at the Ba site, and thus the luminance may be low. If y is greater than 0.3, the luminance may be high, but the color purity may be too low to be used as a display phosphor. Because there is.

Meanwhile, in Formula 1, p = 1, q = 10, and r = 17. Or p = 1, q = 14, r = 23, but is not limited thereto.

Typically, the phosphor layer forming step including the phosphor includes applying a composition for forming a phosphor on the substrate on which the phosphor layer is to be formed, and then heat-treating it at a temperature of about 500 ° C. In addition, after the phosphor layer is formed in this manner, the front substrate and the back substrate are adhered to each other, which involves a heat treatment at a temperature of about 400 ° C. In particular, phosphors using Eu ²⁺ as an activator are worsened due to oxidation of the activator during the heat treatment process as described above. In addition, the phosphor may be deteriorated by ultraviolet rays having a specific wavelength (for example, 147 nm and 172 nm) generated during discharge of the plasma display panel having the phosphor layer, and the emission intensity is decreased by continuous light emission. Can be.

However, the phosphor having the formula (1) facilitates energy transfer in the phosphor matrix by increasing the Sr substitution of a portion of the Ba—O site, thereby increasing energy efficiency. In addition, the phosphor deterioration phenomenon which may be caused by the determination of the Ba-O site can be prevented due to the substitution of Sr. Therefore, the above-mentioned phosphor degradation and light emission intensity fall phenomenon can be prevented.

Table 1 below shows the y color coordinates, relative luminance, and efficiency of the phosphor having the general formula (1) according to the change in the Sr content. Ba _1-xy Sr _y MgAl ₁₀ O ₁₇ : Eu _x (x = 0.1) phosphor was used, and color purity and relative luminance were measured using a CA-100 ⁺ luminance meter. The efficiency was calculated from the y value of the color purity relative to the relative luminance value.

Sr molar ratio (y) Relative luminance (cd / m ² ) CIEy Efficiency (L / CIEy) 0 100 0.060 1667 0.15 109 0.065 1677 0.21 113 0.068 1662 0.25 120 0.071 1690 0.3 124 0.074 1676 0.35 125 0.076 1645

As shown in Table 1, in the case of the SrBAM phosphor substituted with about 20% to 30% of Sr, the emission luminance is increased by about 20% compared to the existing phosphor, but as a result of the color coordinate variation, the y coordinate is increased to emit light blue. do. In order to compensate for this, the present invention uses a blue phosphor containing a CMS-based phosphor having a deep blue color with a y color coordinate value of about 0.037 in the phosphor having Formula 1, and simultaneously improves luminance and color purity. To provide.

More specifically, according to one embodiment of the present invention, the CMS-based phosphor is selected from the group consisting of CaMgSi ₂ O ₆ : Eu, Ca ₃ MgSi ₂ O ₈ : Eu and Ca ₂ MgSiO ₄ : Eu.

In addition, the phosphor having Formula 1 and the CMS-based phosphor may be mixed in a weight ratio of 1: 1.

Table 2 below shows a mixture of Ba _1-xy Sr _y MgAl ₁₀ O ₁₇ : Eu _x (x = 0.1) phosphor and CaMgSi ₂ O ₆ : Eu, which is a CMS-based phosphor, in a weight ratio of 1: 1 in the phosphor having Chemical Formula 1 In one blue phosphor, relative luminance, y-color coordinates, and efficiency with respect to changes in the content of Sr are shown. More specifically, 6 parts by weight of ethyl cellulose, which is a binder, is mixed with 100 parts by weight of a mixed solvent of butylcarbitol acetate and terpineol in a weight ratio of 5: 5 to prepare a binder solution, and 100 parts by weight of the binder solution. The present invention relates to a blue phosphor obtained by mixing 20 parts by weight of a phosphor having Formula 1 and 20 parts by weight of a CMS-based phosphor.

Sr molar ratio (y) Relative luminance (cd / m ² ) CIEy Efficiency (L / CIEy) 0.21 100 0.054 1852 0.25 105 0.056 1875 0.3 110 0.058 1897

As shown in Table 2, a blue phosphor including a Ba _1-xy Sr _y MgAl ₁₀ O ₁₇ : Eu _x (x = 0.1) phosphor and a CaMgSi ₂ O ₆ : Eu CMS-based phosphor according to an embodiment of the present invention It can be seen that the value of the y color coordinate is improved when compared to the y color coordinate of the Ba _1-xy Sr _y MgAl ₁₀ O ₁₇ : Eu _x (x = 0.1) phosphor shown in Table 1 above.

Accordingly, the blue phosphor according to the present invention can be used in a plasma display panel. The present invention provides a plasma display panel including a phosphor layer including the phosphor having Formula 1 and a CMS-based phosphor.

Referring to FIG. 1, a plasma display panel 100 according to an embodiment of the present invention is illustrated.

The plasma display panel 100 according to the exemplary embodiment of the present invention includes a first substrate 111 and a second substrate 121, sustain electrode pairs 112, a first dielectric layer 115, a protective layer 116, The address electrodes 122, the second dielectric layer 125, the partition walls 130, the phosphor layer 126, and a discharge gas (not shown) may be provided.

The plasma display panel 100 includes a first substrate 111 and a second substrate 121 spaced apart from each other and disposed to face each other. The first substrate 111 and the second substrate 121 are generally made of a material having excellent light transmittance mainly composed of glass, but may be colored in order to reduce reflection brightness and improve clear room contrast.

In the present embodiment, since the first substrate 111 is transparent, visible light generated by the discharge passes through the first substrate 111, but the present invention is not limited thereto. That is, while the first substrate of the present invention is opaque, the second substrate may be configured to be transparent, and the first substrate and the second substrate may be configured to be transparent at the same time. In addition, the first substrate and the second substrate of the present invention may be made of a semi-transparent material, it may be configured by embedding a color filter, electromagnetic shielding filter and the like on the surface or inside thereof.

On the first substrate 111, the X electrode 113 and the Y electrode 114 correspond to the sustain electrode pairs 112 in the discharge cell 140, form a discharge gap, and generate a plasma discharge. Each of the X electrode 113 and the Y electrode 114 is a bus electrode 113a or 114a made of a metal material having excellent electrical conductivity which is formed in one direction on the first substrate 111 and the bus electrode 113a. It includes a transparent electrode 113b (114b) such as indium tin oxide (ITO) formed in a structure covering the (114a).

In the present embodiment, a surface discharge type of a typical three electrode is disclosed, but the present invention is not limited thereto. That is, the present invention can also be applied to an opposite discharge structure in which sustain electrode pairs are spaced apart from each other and are surrounded by a dielectric.

The first dielectric layer 115 may be formed on the entire surface of the first substrate 111 while covering the X electrode 113 and the Y electrode 114 on the first substrate 111. The first dielectric 115 induces charge while preventing direct damage to adjacent X electrodes 113 and Y electrodes 114 by directly colliding with adjacent X electrodes 113 and Y electrodes 114 during discharge. And a dielectric material capable of accumulating wall charges. Examples of such dielectrics include PbO, B 2 O 3, and SiO 2.

In addition, a protective layer (not shown) may be formed on the first dielectric layer 115. The protective layer prevents the cations and the electrons from colliding with the first dielectric layer 115 during the discharge to damage the first dielectric layer 115, and discharges a lot of secondary electrons during the discharge to lower the discharge voltage. The protective layer may be formed by depositing magnesium oxide (MgO) on the first dielectric layer.

On the second substrate 121 facing the first substrate 11, the address electrodes 122 for generating an address discharge for facilitating sustain discharge between the X electrodes 113 and the Y electrodes 114 are arranged side by side. It is stretched out. In addition, a second dielectric layer 125 having the same function as the first dielectric layer 115 may be formed on the entire surface of the rear substrate 121 while covering the address electrodes 122.

A partition wall 130 is formed between the first substrate 110 and the second substrate 120 to define a plurality of discharge cells 140 and define a space in which the phosphor layer is disposed. Although the present embodiment has a closed waffle structure, the present invention is not limited thereto.

Phosphor layers 126 of red, green, and blue are formed on the bottom surface of the discharge cells 140 and the side surfaces of the partition wall 130, respectively. The phosphor layers 126 have a component that generates ultraviolet light by receiving ultraviolet rays, and the red phosphor layer includes phosphors such as Y (V, P) O 4: Eu, and the green phosphor layers include phosphors such as Zn 2 SiO 4: Mn. It includes, and the blue phosphor layer is composed of a blue phosphor including a phosphor having a chemical formula 1 and a CMS-based phosphor of the present invention.

The blue phosphor layer was prepared by mixing 6 parts by weight of ethyl cellulose, which is a binder, with respect to 100 parts by weight of a mixed solvent of butylcarbitol acetate and terpineol in a weight ratio of 5: 5, to prepare a binder solution, and based on 100 parts by weight of the binder solution. After preparing a phosphor paste by mixing 20 parts by weight of the phosphor having Formula 1 and 20 parts by weight of a CMS-based phosphor, the paste is formed on the bottom surface of the discharge cell partitioned by the partition wall and the side surfaces of the partition walls.

In addition, the discharge cells 140 are filled with a discharge gas in which xenon (Xe), neon (Ne), and the like are mixed. In the state where the discharge gas is filled as described above, the first and second substrates are sealed to each other by a sealing member such as frit glass formed at the edge of the substrate.

The driving method of the plasma display panel of the present invention having the above-described structure is as follows.

First, an address discharge occurs by applying an address voltage between the address electrodes 122 and the Y electrodes 114, and as a result of this address discharge, a discharge cell in which a sustain discharge is to be generated is selected. Thereafter, when a sustain voltage is applied between the X electrodes 113 and the Y electrodes 114 of the selected discharge cells, the cations accumulated on the Y electrodes 114 and the X electrodes 113 are stacked. The discharged electrons cause sustain discharge, and after that, voltage pulses applied to the X electrodes 113 and the Y electrodes 114 alternately generate continuous discharges. As the energy level of the mixed gas of Xe and Ne excited by this sustain discharge is lowered, vacuum ultraviolet (VUV) of 147 nm to 200 nm is emitted to excite the phosphor. At this time, visible light is emitted from the excited fluorescent light layer, and the emitted visible light constitutes an image.

Among the visible lights, the blue visible light emitted from the blue phosphor not only improves the luminance of light emitted from the conventional blue BAM phosphor, but also obtains y-coordinates to compensate for the increased luminance, thereby improving both luminance and color purity. To provide a panel.

Hereinafter, another embodiment of the present invention will be described with reference to FIGS. 2 and 3.

2 and 3 are schematic partial cross-sectional views of a plasma display panel according to other embodiments of the present invention.

Referring to FIG. 2, in the SrBAM phosphor having Formula 1, the phosphor layer 226a is formed on the bottom surface of the discharge cell, and the phosphor layer 226b is formed on the side surface of the partition wall 230 of the discharge cell. A CMS-based phosphor is formed on the SrBAM phosphor layer 226b formed on the side of the discharge cell to form a layer 226c.

The CMS-based phosphor has a low y-color coordinate value, and thus has a function of compensating for improved luminance as well as preventing deterioration by using the SrBAM phosphor in combination with an embodiment of the present invention.

In general, the fluorescent material applied to the portion close to the discharge sustaining electrode is severely deteriorated by sputtering, and by applying a CMS series phosphor having excellent heat resistance against degradation to the side of the partition wall close to the discharge sustaining electrode, the degradation is prevented. can do.

Meanwhile, the thickness of the CMS-based phosphor layer 226c is preferably about 1 to 40 μm, and the thickness of all the side phosphor layers 226b and 226c does not exceed 50 μm. When the thickness of the CMS-based phosphor layer positioned on the surface layer of the side phosphor layer is less than 1 μm, the deterioration prevention effect is insignificant, and when it exceeds 40 μm, the luminance characteristic may be reduced. In the present invention, the thickness of the side phosphor layer is based on the thickness measured in the direction perpendicular to the side wall of the partition wall at the center of the partition wall height.

Referring to FIG. 3, in the SrBAM phosphor having Formula 1, a phosphor layer 326a is formed on a bottom surface of a discharge cell, and a CMS-based phosphor is formed on a side of the discharge cell by forming a single layer 326c.

On the other hand, the thickness of the CMS-based phosphor layer 326c is preferably about 1 to 50㎛. When the thickness of the CMS-based phosphor layer coated on the side is less than 1 μm, the deterioration prevention effect is insignificant. When the thickness of the CMS-based phosphor layer is greater than 50 μm, the luminance characteristics and the discharge space may be reduced.

Plasma display panel according to another embodiment of the present invention described above is the same as the configuration, operation and effect of the plasma display panel according to an embodiment of the present invention except for the above configuration, operation and effect, in the present description It will be omitted.

The phosphor according to the present invention has excellent heat resistance, luminance characteristics, lifespan characteristics, and color purity with respect to excitation light that can be generated in a plasma display panel. You can get it.

Although the present invention has been described with reference to the embodiments illustrated in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims (10)

Blue phosphor comprising a phosphor having the formula (1) and a phosphor of the CMS series. <Formula 1> Ba _1-xy Sr _y Mg _p Al _q O _r : Eu _x , In Formula 1,  0.001 ≦ x ≦ 0.1 and 0.021 ≦ y ≦ 0.3; p = 1, q = 10, r = 17, or p = 1, q = 14, r = 23. The method of claim 1, Phosphor having Formula 1 is blue blue, characterized in that the formula Ba _0.65 Sr _0.25 MgAl ₁₀ O ₁₇ : Eu _0.1 , Ba _0.69 Sr _0.21 MgAl ₁₀ O ₁₇ : Eu _0.1, Ba _0.6 Sr _0.3 MgAl ₁₀ O ₁₇ : Eu _0.1 Phosphor. The method of claim 1, The CMS-based phosphor is at least one selected from the group consisting of CaMgSi ₂ O ₆ : Eu, Ca ₃ MgSi ₂ O ₈ : Eu and Ca ₂ MgSiO ₄ : Eu. The method of claim 1, Blue phosphor, characterized in that the weight ratio of the phosphor having Formula 1 and the CMS-based phosphor is 1: 1. A plasma display panel comprising a phosphor layer comprising the phosphor of any one of claims 1 to 4. The method of claim 5, The plasma display panel, A first substrate and a second substrate spaced apart from each other to face each other; Barrier ribs that partition a space between the first substrate and the second substrate into a plurality of discharge cells; A plurality of electrodes arranged around the discharge cells to cause discharge; And A red phosphor layer, a green phosphor layer, and a blue phosphor layer applied to bottom surfaces of the discharge cells and side surfaces of the partition walls; Plasma display panel having a. The method of claim 6, The blue phosphor layer coated on the side wall of the discharge cell is a plasma display panel, characterized in that the CMS-based phosphor layer is applied to the outside of the Ba _1-xy Sr _y Mg _p Al _q O _r : Eu _x type phosphor layer. The method of claim 7, wherein The Ba _1-xy Sr _y Mg _p Al _q O _r : The thickness of the CMS-based blue phosphor layer applied to the outside of the Eu _x phosphor layer is 1 to 40㎛. The method of claim 6, The blue phosphor layer coated on the sidewall of the discharge cell is a plasma display panel which is a single layer of the CMS-based blue phosphor layer. The method of claim 9, The thickness of the CMS-based blue phosphor layer applied to the side wall of the discharge cell is 1 to 50㎛ plasma display panel.

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