JP2001335777A - Vacuum ultraviolet ray-excited fluorophor and light emitting device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the emission efficiency of green light emission by vacuum ultraviolet rays using that of not higher than 200 nm wave length as an excitation source. SOLUTION: This vacuum ultraviolet rays-excited fluorophor has a composition substantially represented by L1-xTbxAl3(BO3)4 (wherein L is at least an element selected from the group consisting of Y and Gd, and 0.1<x<=0.7), or L1-x-yTbxCeyAl3(BO3)4 (wherein 0.1<x<=0.7, and 0.00001<=y<=0.01). The vacuum ultraviolet rays-excited fluorophor is used for a light emission device using vacuum ultraviolet rays such as of a gas discharge lamp and a PDP as an excitation source. This light emission device has a light emission layer 5 containing a vacuum ultraviolet fluorophor which emits a green light and a means irradiating the vacuum ultraviolet rays to the light emission layer 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum-ultraviolet-excited phosphor emitting green light and a light-emitting device using the same.

[0002]

2. Description of the Related Art In recent years, a light emitting device using vacuum ultraviolet rays of a short wavelength (for example, a wavelength of 200 nm or less) emitted by rare gas discharge as an excitation source of a phosphor has been developed. In such a light emitting device, a phosphor that emits light using vacuum ultraviolet light as an excitation source, that is, a vacuum ultraviolet light excited phosphor is used.

Light emitting devices using vacuum ultraviolet light as an excitation source are used, for example, in display devices. A plasma display panel (PDP) is known as such a display device. With the advent of the multimedia era, a display device that is a core device of a digital network is required to have a large screen, to be thin, and to be capable of digital display. PDP has such characteristics. That is, PDPs are attracting attention as digital display devices capable of projecting various kinds of information with high precision and high definition, and capable of increasing the screen size and thinning.

Light emitting devices using vacuum ultraviolet light as an excitation source include not only display devices such as PDPs but also xenon (X
Noble gas discharge lamps utilizing discharge light emission by a rare gas such as e) are known. Rare gas discharge lamps are used in place of conventional mercury (Hg) discharge lamps, such as backlights for in-vehicle liquid crystal displays, and in applications requiring safety and the like. Since noble gas discharge lamps do not use harmful mercury, they are also attracting attention as discharge lamps having excellent environmental safety.

What is common to the vacuum ultraviolet excitation type light emitting devices described above is that instead of the conventional ultraviolet rays (wavelength: 254 nm) from an electron beam or mercury, the excitation source of the phosphor is replaced with a conventional one.
In other words, vacuum ultraviolet rays having a wavelength of 147 nm or 172 nm emitted by rare gas discharge are used. There are few studies to emit phosphors in the vacuum ultraviolet region.Therefore, in the vacuum ultraviolet excitation type light-emitting device, a device that has comparatively excellent emission characteristics with vacuum ultraviolet light is empirically selected from among conventionally known phosphors. Used.

For example, in order to realize full-color display on a PDP, phosphors that emit red, green, and blue light are required. Therefore, in the conventional full-color PDP,
(Y, Gd) BO ₃ : Eu phosphor as a red light-emitting phosphor, Zn ₂ SiO ₄ : Mn phosphor as a green light-emitting phosphor,
BaMgAl ₁₀ O ₁₇ : Eu phosphor or the like is used as a blue light emitting phosphor. As a rare gas discharge lamp, a mixture of the above-described phosphors of each color emission is generally used.

As a green light emitting phosphor for excitation of vacuum ultraviolet light
Is (Ba, Sr) Al₁₂O ₁₉: Mn or (Ba,
Sr) MgAl₁₄O_{twenty three}: Manganese-activated alka such as Mn
Lithium aluminate phosphors and the like are known. JP10
No. -1666 discloses a green light emitting phosphor for vacuum ultraviolet excitation
As (Ba, Sr) MgAl_TenO₁₇: Mn and (B
a, Sr) O.6Al_TwoO_ThreeAnd solid solution at a predetermined ratio
A manganese activated aluminate phosphor is described.

Further, Japanese Patent Application Laid-Open No. Hei 7-3261 discloses a (R _{1 -x} , Tb _x ) ₂ O ₃ .bB ₂ O as a green light-emitting phosphor for exciting vacuum ultraviolet rays having a wavelength of 147 nm by rare gas discharge. ₃ describes a terbium-activated rare earth borate phosphor represented by (R is at least one element selected from Y, La and Gd, 0.06 ≦ x ≦ 0.12, 0 ≦ b / a ≦ 1.3). JP
The 11-71581 _{discloses, (Y 1-xy, Gd} x, Tb y) 2 O 3
・ B ₂ O ₃ (0.08 ≦ x ≦ 0.8, 0.05 ≦ y ≦ 0.25, 0.13 ≦ x
+ Y ≦ 1.0), which describes a terbium-activated rare earth borate phosphor. Each of these rare earth borate phosphors has a cubic crystal structure.

[0009]

In the above-mentioned PDP and rare gas discharge lamp, in order to realize a high-luminance light emitting device, it is necessary to increase the luminous efficiency in each of red, green and blue. That is, it is indispensable to emit light with high efficiency when the phosphors emitting red, green, and blue light are excited by vacuum ultraviolet rays having a wavelength of 147 nm or 172 nm.
Among them, in order to improve the white luminance, it is important to increase the luminous efficiency of the green light-emitting phosphor having particularly high visibility by vacuum ultraviolet excitation.

However, the conventional green light-emitting phosphor for exciting vacuum ultraviolet rays does not provide sufficient luminous efficiency.
There is a strong demand for further improving the luminous efficiency of the green light emitting phosphor. The above-described manganese-activated aluminate phosphor and terbium-activated rare earth borate phosphor aim at increasing the luminance of a green light-emitting phosphor by vacuum ultraviolet rays, but do not necessarily provide sufficient luminous efficiency. . In order to achieve high luminance of the light emitting device, a green light emitting phosphor that further enhances the luminous efficiency when excited by vacuum ultraviolet light is required.

In the rare gas discharge lamp, since phosphors of three colors are mixed and used, luminous efficiency (luminance) by excitation with vacuum ultraviolet rays is more important than chromaticity as green luminescence. For this reason, it is desired that the green light-emitting phosphor used in the rare gas discharge lamp has a higher luminous efficiency particularly when excited by vacuum ultraviolet light.

The present invention has been made to address such a problem, and has a vacuum ultraviolet-excited phosphor that further improves the luminous efficiency of green light when excited by vacuum ultraviolet having a wavelength of 200 nm or less. It is an object of the present invention to provide a light-emitting device that achieves high luminance by using such a green-light-emitting vacuum ultraviolet-excited phosphor.

[0013]

Means for Solving the Problems The present inventors have studied various phosphors in order to achieve the above-mentioned object, and as a result, a rare earth / aluminum borate was used as a phosphor matrix, and terbium was added thereto. The active phosphor efficiently absorbs vacuum ultraviolet rays, and can contain Tb, which is a luminescence center, in a relatively high concentration, and based on these, excellent green light emission efficiency (luminance) can be obtained. I found it.
Further, they have found that the luminous efficiency (luminance) is further improved by adding a small amount of Ce to the terbium-activated rare earth / aluminum borate phosphor.

The present invention has been made based on such findings, and the first VUV-excited phosphor of the present invention emits green light when excited by VUV. A vacuum ultraviolet-excited phosphor having a phosphor represented by the general formula: L _1-x Tb _x Al ₃ (BO ₃ ) ₄ (wherein L represents at least one element selected from Y and Gd) , X is a number satisfying 0.1 <x ≦ 0.7)
Is characterized by having a composition substantially represented by

The second VUV-excited phosphor of the present invention comprises:
As described in claim 2, a general formula: L _1-xy Tb _x Ce _y Al ₃ (BO ₃ ) ₄ (wherein L represents at least one element selected from Y and Gd, and x and y Is 0.1 <x ≦ 0.7, 0.00001 ≦
y is a number satisfying y ≦ 0.01).

In the first and second VUV-excited phosphors of the present invention, the value of x indicating the content of Tb is preferably set to be 3 or 4.
As described above, it is more preferable that the range of 0.2 ≦ x ≦ 0.6 is satisfied. The L element may be any one of Y and Gd, or a mixture thereof. In particular,
As described in claim 4, 50 atomic% or more of the L element is G.
It is preferably d. The VUV-excited phosphor of the present invention is suitable as a green-emitting phosphor for a rare gas discharge lamp.

According to a ninth aspect of the present invention, there is provided a light emitting device comprising the above-described vacuum ultraviolet ray excited phosphor of the present invention. As a specific embodiment of the light emitting device of the present invention, a green light-emitting vacuum ultraviolet ray excited phosphor of the present invention, a light emitting layer containing a mixture of a blue light emitting phosphor and a red light emitting phosphor, and a vacuum ultraviolet light is applied to the light emitting layer. And a irradiating means. In another specific embodiment, the light-emitting device includes a light-emitting layer including the green light-emitting vacuum-ultraviolet-excited phosphor, the blue light-emitting phosphor, and the red light-emitting phosphor of the present invention, and a unit that irradiates the light-emitting layer with vacuum ultraviolet light. Plasma display panel (PDP).

[0018]

Embodiments of the present invention will be described below.

The VUV-excited phosphor of the present invention is a phosphor which emits green light when irradiated with VUV, and has a general formula: L ₁ -xTb _x Al ₃ (BO ₃ ) ₄ (1) (Where L represents at least one element selected from Y and Gd, and x is a number satisfying 0.1 <x ≦ 0.7)
Has a composition substantially represented by

The vacuum ultraviolet light to be used in the present invention is, for example, ultraviolet light having a short wavelength of 200 nm or less.
Such vacuum ultraviolet rays are Xe gas, Xe-Ne gas, Xe gas.
It is emitted by discharge using a rare gas such as e-He gas. Practically, vacuum ultraviolet light having a wavelength of 147 nm or 172 nm is used.

In the vacuum ultraviolet ray excited phosphor of the present invention,
The L element, aluminum (Al), boron (B) and oxygen (O) are elements that constitute a rare earth / aluminum borate (LAl ₃ (BO ₃ ) ₄ ) serving as a phosphor matrix. Among these, the L element may be either Y or Gd alone, or may be a mixture thereof. In order to further improve the luminous efficiency of the VUV-excited phosphor, it is preferable that at least a part of the L element is Gd.

The VUV-excited phosphor containing Gd as at least a part of the L element has the general _{formula: (Gd 1-a, Y} a) 1-x Tb x Al 3 (BO 3) 4 ... (2) ( Formula Wherein a and x are numbers satisfying 0 ≦ a <1, 0.1 <x ≦ 0.7). (2) The value of a in the equation is 0
It is more preferable to set the range of ≦ a ≦ 0.5. That is, it is more preferable that 50 atomic% or more of the L element is Gd. Gd desirably accounts for 70 atomic% or more of the L element.

The VUV-excited phosphor of the present invention uses a rare earth / aluminum borate (LAl ₃ (BO ₃ ) ₄ ) having a rhombohedral crystal structure as a phosphor matrix and an appropriate amount of terbium (Tb). Is contained. Part of the L element is replaced by Tb that becomes the emission center. According to such a vacuum ultraviolet ray excited phosphor, it is possible to obtain high-luminance green light emission when irradiated with vacuum ultraviolet light.

That is, in the phosphor excited by the vacuum ultraviolet ray, the compound (silicate, aluminate, borate, etc.) as the phosphor matrix absorbs the vacuum ultraviolet ray, and the luminescent center is absorbed by the vacuum ultraviolet ray absorbed by the phosphor matrix. (Mn or Tb) emits green light. In such a light emission mechanism, conventional Mn-activated silicate phosphor, Mn-activated aluminate phosphor, and Tb-activated rare earth borate phosphor are:
Irradiated vacuum ultraviolet rays are not used efficiently because the absorption efficiency of vacuum ultraviolet rays by the phosphor matrix is insufficient.

For example, a Tb-activated rare earth borate phosphor such as a (Y, Gd) BO ₃ : Tb phosphor uses a cubic rare earth borate as a phosphor matrix. Such a phosphor matrix has insufficient absorption efficiency of vacuum ultraviolet rays, and cannot sufficiently increase the content of Tb functioning as a luminescence center. For this reason, the Tb-activated rare earth borate phosphor cannot sufficiently enhance the luminous efficiency of green light emission when irradiated with vacuum ultraviolet rays.

On the other hand, Tb-activated rare earth / aluminum borate (L _1-x Al ₃ (BO ₃ ) ₄ : Tb)
_x ) Phosphors have a rhombohedral crystal structure as a rare earth / aluminum borate as a phosphor matrix, and have excellent absorption efficiency of vacuum ultraviolet rays. Out. Further, the rare earth / aluminum borate can set the replacement amount of L element by Tb high. Based on these, according to the VUV-excited phosphor of the present invention, it is possible to improve the luminous efficiency of green light emission (light emission based on Tb) as compared with a conventional green light-emitting phosphor.

In the vacuum ultraviolet ray excited phosphor of the present invention,
The content of Tb that becomes the emission center exceeds 0.1 as the value of x
0.7 or less. When the value of x is 0.1 or less, the luminous efficiency of green light emission decreases. On the other hand, when the value of x exceeds 0.7, it becomes difficult to maintain the crystal structure of the phosphor matrix, and the luminous efficiency of green light emission also decreases. In other words, if the value of x exceeds 0.1 and is 0.7 or less,
It becomes possible to obtain high-luminance green light emission when excited by vacuum ultraviolet light.

In particular, in order to increase the luminance of green light emission when excited by vacuum ultraviolet rays, the value of x indicating the Tb content is 0.2
It is preferable to set the range of ≦ x ≦ 0.6. According to the VUV-excited phosphor using a rare earth / aluminum borate as a phosphor matrix, Tb can be replaced with up to about 60% of the L element while maintaining a good crystal structure of the phosphor matrix. Further, by replacing 20% or more of the L element with Tb, high-luminance green light emission can be obtained. More preferably, the content of Tb is in the range of 0.2 ≦ x ≦ 0.5.

Further, the VUV-excited phosphor of the present invention is a conventional VUV-excited phosphor which emits green light and is Zn.
_It also has the advantage that the afterglow time is shorter than that of a ₂ SiO ₄ : Mn phosphor or the like. The afterglow time is a time from when the irradiation of the vacuum ultraviolet light is cut off to when the light emission attenuates. Specifically, after blocking the vacuum ultraviolet light, the luminance is reduced to 1/10
It shall indicate the time until: By shortening the afterglow time of the VUV-excited phosphor, for example, in a display device, it is possible to improve moving image characteristics.

The VUV-excited phosphor of the present invention comprises a small amount of cerium (C) in addition to the activator terbium (Tb).
e) may be included as a coactivator. By activating Tb and Ce on rare earth aluminum borate,
The luminous efficiency of green light emission upon irradiation with vacuum ultraviolet rays can be further increased.

The vacuum ultraviolet ray excited phosphor using Ce as a co-activator is represented by the general formula: L _1-xy Tb _x Ce _y Al ₃ (BO ₃ ) ₄ (3) wherein x and y are 0.1 and 0.1, respectively. <X ≦ 0.7, 0.00001 ≦ y ≦ 0.0
A number that satisfies 1). Ce
Is 0.00001 to 0.0 as the value of y in the above equation (3).
It is preferred to be in the range of 1. If the value of y exceeds 0.01, the luminous efficiency may be reduced. The lower limit of y is not necessarily limited, but is preferably 0.00001 or more in order to effectively obtain the effect of adding Ce. The conditions other than Ce are as described above.

The VUV-excited phosphor of the present invention has a wavelength of 20
Vacuum ultraviolet light of 0 nm or less (for example, vacuum ultraviolet light of 147 nm wavelength)
Irradiates green light in which the value of x in the CIE chromaticity value (x, y) is in the range of 0.28 to 0.34 and the value of y is in the range of 0.57 to 0.60. More preferably, the CIE chromaticity value (x, y) of green emission is such that the value of x is in the range of 0.30 to 0.32 and the value of y is in the range of 0.58 to 0.60.

The VUV-excited phosphor of the present invention is useful for applications requiring high-luminance green light emission, although the emission chromaticity is slightly inferior to that of the conventional green-light-emitting VUV-excited phosphor. The vacuum ultraviolet ray excited phosphor of the present invention,
It is suitable for a green light emitting phosphor for a rare gas discharge lamp used in combination with a blue and red light emitting vacuum ultraviolet excited phosphor.

The VUV-excited phosphor of the present invention is manufactured, for example, as follows. First, Y, Gd, Tb,
Oxides of Al and B, or compounds such as hydroxides and carbonates that readily become oxides at high temperatures, and if necessary, compounds such as oxides, hydroxides and carbonates of Ce are used as raw materials. . Each of these raw material powders was described above
A predetermined amount is weighed so that the composition of the formula (1) or (3) is obtained,
These are thoroughly mixed with a flux such as barium fluoride, aluminum fluoride, and magnesium fluoride using a ball mill or the like.

Next, the above-mentioned raw material mixture is accommodated in a heat-resistant container such as an alumina crucible and fired in the atmosphere at a temperature of 950 to 1100 ° C. for 3 to 5 hours (primary firing). After the obtained fired product is pulverized and sieved, it is again stored in a heat-resistant container such as an alumina crucible, and a reduction aid such as graphite is placed thereon, and the lid is placed thereon. In this state, the forming gas (N ₂ +
H ₂ ) at a temperature of 950 to 1100 ° C in a reducing atmosphere.
Bake for 5 hours (secondary baking). Secondary firing is effective for improving luminance.

Thereafter, the obtained calcined product is dispersed, washed with water,
By performing various processes such as drying and sieving as required, the desired Tb-activated (or Tb and Ce-activated) rare earth / aluminum borate phosphor, that is, the green-emitting vacuum ultraviolet-excitation fluorescence of the present invention is emitted. The body is obtained.

The VUV-excited phosphor (green-emitting phosphor) of the present invention is used in a light-emitting device in which vacuum ultraviolet light having a wavelength of 147 nm or 172 nm is used as a phosphor excitation source. That is, the light emitting device of the present invention includes the vacuum-ultraviolet-excited phosphor of the present invention that emits green light. Specific examples of such a light emitting device include a rare gas discharge lamp such as a Xe discharge lamp and a plasma display panel (PDP).

FIG. 1 shows a configuration of a first embodiment in which the light emitting device of the present invention is applied to a rare gas discharge lamp. FIG. 1A shows a flat type rare gas discharge lamp 1.
1 (b) is a cross-sectional view taken along line XX 'of FIG. 1 (a).

The flat type rare gas discharge lamp 1 shown in FIG.
And an airtight container 4 constituted by the above. Phosphor layers 5, 5 are formed on the rear glass container 2 and the front glass plate 3, respectively, as light emitting layers.

The phosphor layer 5 contains the green-light-emitting vacuum-ultraviolet-excited phosphor according to the present invention. For example, the phosphor layer 5
Comprises a mixed phosphor obtained by mixing the green light emitting phosphor of the present invention with blue and red light emitting phosphors. In this case, various known vacuum ultraviolet ray excited phosphors are used as the phosphors for emitting blue and red light.

A pair of electrodes 6 are formed on the front glass plate 3 so as to be located at both ends in the airtight container 4. The first electrode 6 a of the pair of electrodes 6 is formed on the phosphor layer 5 via the insulating layer 7. The second electrode 6b is formed directly on the phosphor layer 5. further,
The airtight container 4 is filled with a rare gas such as Xe gas, and is sealed airtight in this state.

In the flat type Xe discharge lamp 1, a rare gas discharge is generated by applying a voltage between the electrodes 6a and 6b at both ends. The phosphor layer 5 is excited by the vacuum ultraviolet rays generated by the rare gas discharge, and visible light (for example, white light) corresponding to the configuration of the phosphor layer 5 is obtained. Since the green-light-emitting VUV-excited phosphor of the present invention has excellent luminous efficiency, it is possible to increase the luminance of the Xe discharge lamp 1 using the same.

Although FIG. 1 shows a configuration example of a flat type Xe discharge lamp, a rare gas discharge lamp to which the light emitting device of the present invention is applied is not limited to this. The light emitting device of the present invention is naturally applicable to a Xe discharge lamp or the like in which a phosphor layer is formed on the inner wall surface of a normal glass tube (glass bulb).

FIG. 2 shows the configuration of a second embodiment in which the light emitting device of the present invention is applied to a PDP. PD shown in FIG.
In P11, a front substrate 12 and a rear substrate 13 made of a transparent substrate such as a glass substrate are arranged to face each other with a predetermined gap therebetween. The space between the substrates 12 and 13 is hermetically sealed by a sealing member (not shown), thereby forming a discharge space 14.

On the surface of the front substrate 12 on the side of the discharge space 14, a phosphor layer 15 is formed as a light emitting layer. The phosphor layer 15 includes a blue light emitting layer formed corresponding to the pixel,
It has a green light emitting layer and a red light emitting layer. Phosphor layer 1
Among the phosphors that emit light of each color constituting 5, the VUV-excited phosphor of the present invention is used for the green light-emitting phosphor.
Note that various known blue and red light-emitting vacuum ultraviolet-excited phosphors are used for the blue and red light-emitting phosphors.

A large number of striped positive and negative electrodes 16 and 17 are formed on the rear substrate 13. These electrodes 16 and 17 are arranged in a matrix. Further, each of the electrodes 16 and 17 is covered with a dielectric layer 18. A protective layer 19 is provided on the surface of the dielectric layer 18.

A rare gas containing a Xe gas or the like is sealed in the discharge space 14 as a discharge medium, and hermetically sealed in this state. As the discharge medium, for example, a mixed gas obtained by mixing He gas or Ne gas and several percent of Xe gas is used.

In such a PDP 11, a voltage is applied between the positive electrode 16 and the negative electrode 17 to generate a rare gas discharge. The phosphor layer 15 is excited by vacuum ultraviolet rays generated by the rare gas discharge, and visible light according to the configuration of the phosphor layer 15 is obtained. Since the phosphor layer 15 has a blue light emitting layer, a green light emitting layer, and a red light emitting layer for each pixel, a predetermined color image is displayed.

The phosphor of the present invention, which emits green light and emits a vacuum ultraviolet ray, is excellent in luminous efficiency, so that the brightness of the PDP 11 using the phosphor can be increased. Further, according to the PDP 11 using the vacuum-ultraviolet-excited phosphor emitting green light of the present invention, the voltage at the start of discharge can be reduced.

It should be noted that various known phosphors can be used for the blue and red light emitting vacuum ultraviolet excitation phosphors. For example, a BaMgAl ₁₀ O ₁₇ : Eu phosphor is used as a blue-light-emitting vacuum ultraviolet excitation phosphor. (Y, Gd)
A BO ₃ : Eu phosphor, a (Y, Gd) ₂ O ₃ : Eu phosphor, or the like is used. However, the phosphors emitting blue and red light in the light emitting device of the present invention are not limited to these, and various kinds of vacuum ultraviolet excited phosphors can be used depending on the intended use.

[0051]

Next, specific examples of the present invention and evaluation results thereof will be described.

Example 1 First, 0.7 mol of Gd ₂ O ₃ and Tb ₄ O ₇ were used as phosphor materials.
The 0.15 mol, was 3mol the Al ₂ O _3, and H ₃ BO ₃ and 8mol weighed. After sufficiently mixing these raw materials, the mixture was filled in an alumina crucible and fired in the atmosphere at 1000 ° C. for 4 hours (primary firing).

Next, the fired product was pulverized and sieved, filled again in an alumina crucible, and further covered with a graphite plate, and capped. In this state, 1000 ° C. in a mixed gas atmosphere of nitrogen and hydrogen (N ₂ 97%: H ₂ 3% (volume ratio))
For 4 hours (secondary firing). The obtained calcined product is sieved to obtain Td represented by Gd _0.7 Tb _0.3 Al ₃ (BO ₃ ) _4.
An activated gadolinium aluminum borate phosphor was obtained.
This phosphor was confirmed by X-ray diffraction to have a rhombohedral crystal structure.

The Tb-activated gadolinium aluminum borate phosphor thus obtained was irradiated with vacuum ultraviolet light having a wavelength of 147 nm, and the emission luminance and emission chromaticity at that time were examined.
The emission luminance is Zn ₂ SiO ₄ which is a conventional green light-emitting phosphor:
It was obtained as a relative value when the luminance of the Mn phosphor (Comparative Example 1) was set to 100. In addition, Zn ₂ SiO ₄ : Mn of Comparative Example 1
The phosphor has a hexagonal crystal structure.

As a result, the emission luminance of the Tb-activated gadolinium aluminum borate phosphor of Example 1 was 12
The emission chromaticity was (0.32, 0.59) in CIE chromaticity value (x, y). Thus, it can be seen that the phosphor of Example 1 has significantly improved luminance of green light emission by vacuum ultraviolet excitation as compared with the conventional phosphor (Comparative Example 1). In addition, after blocking the vacuum ultraviolet rays,
When the time required to reach 1/10 or less was measured as the afterglow time, the phosphor of Comparative Example 1 was 14 ms, whereas the phosphor of Example 1 showed a good value of 4 ms.

Next, gadolinium-activated Tb of Example 1 was used.
Aluminum borate phosphor and Zn ₂ Si of Comparative Example 1
Xe discharge lamps were constructed using the O ₄ : Mn phosphors, and the emission luminance and emission chromaticity when each Xe discharge lamp was turned on were measured. As a result, the emission luminance of the Xe discharge lamp using the phosphor of Example 1 was 118% when the emission luminance of the Xe discharge lamp using the phosphor of Comparative Example 1 was 100, and the emission chromaticity was Is (x, y) = (0.3
1, 0.59). It can be seen that the Xe discharge lamp according to Example 1 has significantly improved luminance compared to the Xe discharge lamp according to Comparative Example 1.

Further, the Tb-activated gadolinium aluminum borate phosphor of Example 1 and the Zn ₂ S of Comparative Example 1
Using the iO ₄ : Mn phosphor, each of the P shown in FIG.
The DP was constructed, and the luminance and chromaticity of green light emission when each PDP emitted light was measured. As a result, the light emission luminance of the PDP using the phosphor of Example 1 was 119% when the light emission luminance of the PDP using the phosphor of Comparative Example 1 was 100, and the light emission chromaticity was (x, y). ) = (0.31, 0.59).
It can be seen that the brightness of the PDP according to Example 1 is significantly improved as compared with the PDP according to Comparative Example 1.

Example 2 As a phosphor material, 0.8 mol of Gd ₂ O ₃ and 0.1 m of Tb ₄ O ₇ were used.
ol, ₃ mol of Al ₂ O ₃ and 8 mol of H ₃ BO ₃ were weighed.
After sufficiently mixing these raw materials, a treatment such as primary baking or secondary baking is performed under the same conditions as in Example 1 to obtain Gd _0.8 T
A Tb-activated gadolinium aluminum borate phosphor represented by b _0.2 Al ₃ (BO ₃ ) ₄ was obtained. This phosphor was confirmed by X-ray diffraction to have a rhombohedral crystal structure.

The Tb-activated gadolinium aluminum borate phosphor thus obtained was applied to vacuum ultraviolet rays (wavelength 147 nm).
m), the emission luminance, emission chromaticity, and afterglow time
The measurement was performed in the same manner as in Example 1. Further, the emission luminance and emission chromaticity of the Xe discharge lamp and the PDP manufactured using this phosphor were measured in the same manner as in Example 1. Table 1 shows the results.

[0060] As Example 3 phosphor materials, 0.35 mol of Gd ₂ O _3, a Y ₂ O ₃ 0.35 m
ol, 0.15 mol of Tb ₄ O ₇ , ₃ mol of Al ₂ O 3, and H ₃ B
8 mol of O ₃ was weighed. After mixing respective raw materials sufficiently, subjected to a treatment such as primary firing and secondary firing under the same conditions as in Example 1, represented by _{Y 0. 35 Gd 0.35 Tb 0.3 Al} 3 (BO 3) 4 Tb An activated gadolinium / yttrium / aluminum borate phosphor was obtained. This phosphor was confirmed by X-ray diffraction to have a rhombohedral crystal structure.

The Tb-activated gadolinium / yttrium / aluminum borate phosphor thus obtained is irradiated with vacuum ultraviolet rays (wavelength: 147 nm) to emit light with high luminance and chromaticity.
The afterglow time was measured in the same manner as in Example 1. further,
Xe discharge lamp and PD manufactured using this phosphor
The emission luminance and emission chromaticity of P were measured in the same manner as in Example 1. Table 1 shows the results.

Examples 4 to 8 The mixing amounts of Gd ₂ O ₃ and Y ₂ O ₃ as the raw materials of the phosphor matrix and Tb ₄ O ₇ as the raw material of the luminescent center are shown in Table 1 for each phosphor composition. A Tb-activated rare earth / aluminum borate phosphor was prepared in the same manner as in Examples 1 to 3, except that the phosphor was changed as described above. X-ray diffraction confirmed that each of these phosphors had a rhombohedral crystal structure.

The Tb-activated rare earth / aluminum borate phosphor thus obtained was irradiated with vacuum ultraviolet rays (wavelength 147 nm), and the emission luminance, emission chromaticity, and afterglow time were the same as in Example 1. Measured. Further, the emission luminance and emission chromaticity of the Xe discharge lamp and the PDP manufactured using each of these phosphors were measured in the same manner as in Example 1. Table 1 shows the results.

Comparative Example 2 Except that the mixing amount of Y ₂ O _{3 as} the raw material of the phosphor matrix and Tb ₄ O ₇ as the raw material of the emission center was changed so as to obtain the phosphor composition shown in Table 1, the procedure was carried out. In the same manner as in Example 1, a Tb-activated rare earth / aluminum borate phosphor was produced. In addition,
This phosphor has a Tb content outside the range of the present invention. This phosphor has a rhombohedral crystal structure.

For the phosphor of Comparative Example 2, the emission luminance, emission chromaticity, and afterglow time when irradiated with vacuum ultraviolet rays were
The measurement was performed in the same manner as in Example 1. Further, the emission luminance and emission chromaticity of the Xe discharge lamp and the PDP manufactured using this phosphor were measured in the same manner as in Example 1. Table 1 shows the results.

Comparative Example 3 0.9 mol of Y ₂ O ₃ and 0.05 mol of Tb ₄ O ₇ were used as phosphor raw materials.
1 mol and 2 mol of H ₃ BO ₃ were weighed. After sufficiently mixing these raw materials, a treatment such as primary baking or secondary baking is performed under the same conditions as in Example 1 to obtain a Tb-activated yttrium borate phosphor represented by Y _0.9 Tb _0.1 BO _3. Was. This phosphor was confirmed by X-ray diffraction to have a cubic crystal structure.

For the phosphor of Comparative Example 3, the emission luminance, emission chromaticity, and afterglow time when irradiated with vacuum ultraviolet light were also
The measurement was performed in the same manner as in Example 1. Further, the emission luminance and emission chromaticity of the Xe discharge lamp and the PDP manufactured using this phosphor were measured in the same manner as in Example 1. Table 1 shows the results.

[0068]

[Table 1]

As is clear from Table 1, the Tb-activated rare earth / aluminum borate phosphor of the present invention has excellent luminous efficiency of green light emission when excited by vacuum ultraviolet rays. In particular, it can be seen that Gd is preferably used as at least a part of the rare earth element L, and that at least 50 atomic% of the L element is Gd from the viewpoint of luminance.

Example 9 As a phosphor material, 0.6999 mol of Gd ₂ O ₃ and 0.1% of CeO ₂ were used.
0001 mol, 0.15 mol of Tb ₄ O ₇ , ₃ mol of Al ₂ O ₃ and 8 mol of H ₃ BO ₃ were weighed. After sufficiently mixing these raw materials, a treatment such as primary baking or secondary baking is performed under the same conditions as in Example 1 to _obtain Gd _0.6999 Ce _0.0001 Tb _0.3 Al ₃ (B
A Tb and Ce activated gadolinium aluminum borate phosphor represented by O ₃ ) ₄ was obtained. This phosphor was confirmed by X-ray diffraction to have a rhombohedral crystal structure.

The Tb- and Ce-activated gadolinium-aluminum borate phosphor thus obtained was irradiated with vacuum ultraviolet rays to measure the emission luminance, emission chromaticity, and afterglow time in the same manner as in Example 1. . Further, the emission luminance and emission chromaticity of the Xe discharge lamp and the PDP manufactured using this phosphor were measured in the same manner as in Example 1. Table 2 shows the results.

Examples 10 to 18 The mixing amounts of Gd ₂ O ₃ and Y ₂ O ₃ as the raw materials of the phosphor matrix, Tb ₄ O _{7 as} the raw material of the emission center, and CeO ₂ as the raw material of the sensitizer were as follows. Tb and Ce-activated rare earth / aluminum borate phosphors were respectively produced in the same manner as in Example 9 except that the phosphor compositions were changed so as to have the phosphor compositions shown in Table 2. X-ray diffraction confirmed that each of these phosphors had a rhombohedral crystal structure.

The Tb and Ce activated rare earth / aluminum borate phosphor thus obtained was irradiated with vacuum ultraviolet rays to measure the emission luminance, emission chromaticity and afterglow time in the same manner as in Example 1. . Further, the emission luminance and emission chromaticity of the Xe discharge lamp and the PDP manufactured using each of these phosphors were measured in the same manner as in Example 1. Table 2 shows the results.

Comparative Example 4 The mixing amounts of Gd ₂ O _{3 as} the raw material of the phosphor matrix, Tb ₄ O _{7 as} the raw material of the luminescent center, and CeO ₂ as the raw material of the sensitizer were
Except for changing the phosphor composition shown in Table 2,
In the same manner as in Example 9, a rare earth / aluminum borate phosphor activated with Tb and Ce was produced. The phosphor is C
The e content is outside the scope of the present invention.

Also for the phosphor of Comparative Example 4, the emission luminance, emission chromaticity, and afterglow time when irradiated with vacuum ultraviolet light were as follows:
The measurement was performed in the same manner as in Example 1. Further, the emission luminance and emission chromaticity of the Xe discharge lamp and the PDP manufactured using this phosphor were measured in the same manner as in Example 1. Table 2 shows the results.

[0076]

[Table 2]

As is clear from Table 2, the Tb and Ce-activated rare earth / aluminum borate phosphors of the present invention have excellent luminous efficiency of green light emission when excited by vacuum ultraviolet rays.

[0078]

As described above, according to the VUV-excited luminescent phosphor of the present invention, the luminous efficiency of green emission can be increased when excited by VUV of 200 nm or less. Therefore, by using such a VUV-excited phosphor in a light-emitting device such as a rare gas discharge lamp or a PDP, it is possible to provide a light-emitting device having excellent emission luminance.

[Brief description of the drawings]

FIG. 1 is a diagram showing a structure of a first embodiment in which a light emitting device of the present invention is applied to a rare gas discharge lamp.

FIG. 2 is a diagram showing a main structure of a second embodiment in which the light emitting device of the present invention is applied to a plasma display panel (PDP).

[Explanation of symbols]

1 ... Rare gas discharge lamps 1,4 ... Airtight containers 4,5 ...
Phosphor layer, 6 ... a pair of electrodes, 11 ... PDP, 14 ...
... discharge space, 15 ... phosphor layer, 16, 17 ... electrodes

Claims (11)

[Claims] 1. A vacuum ultraviolet ray excited phosphor comprising a phosphor that emits green light when excited by vacuum ultraviolet ray, wherein the phosphor is represented by a general formula: L _{1 -x} Tb _x Al ₃ (BO ₃ ) ₄ (Where L represents at least one element selected from Y and Gd, and x is a number satisfying 0.1 <x ≦ 0.7)
A vacuum ultraviolet ray excited phosphor characterized by having a composition substantially represented by: 2. A vacuum ultraviolet ray excited phosphor comprising a phosphor that emits green light when excited by vacuum ultraviolet ray, wherein the phosphor is represented by a general formula: L _1-xy Tb _x Ce _y Al ₃ (BO _{3 4} (wherein L represents at least one element selected from Y and Gd, and x and y are 0.1 <x ≦ 0.7, 0.00001 ≦
V is a number that satisfies y ≦ 0.01). 3. The VUV-excited fluorescent material according to claim 1, wherein the value of x indicating the content of Tb is in the range of 0.2 ≦ x ≦ 0.6. body. 4. The vacuum ultraviolet ray excited phosphor according to claim 1, wherein 50 atomic% or more of the L element is Gd. 5. The VUV-excited phosphor according to claim 1, wherein the phosphor has a rhombohedral crystal structure. 6. The vacuum ultraviolet ray excited phosphor according to claim 1, wherein the phosphor has a CIE chromaticity value (x, ，) when irradiated with vacuum ultraviolet ray having a wavelength of 200 nm or less. x value in y) is 0.28-0.
A VUV-excited phosphor, which emits green light in a range of 34 and a y value in a range of 0.57 to 0.60. 7. The vacuum ultraviolet ray excited phosphor according to claim 1, wherein the phosphor is used as a green light emitting phosphor for a rare gas discharge lamp. 8. The vacuum ultraviolet ray excited phosphor according to claim 1, wherein the phosphor is used as a green light emitting phosphor for a plasma display panel. 9. A light-emitting device comprising the green-light-emitting vacuum-ultraviolet-excited phosphor according to any one of claims 1 to 6. 10. The light emitting device according to claim 9, wherein a light emitting layer containing a mixture of the green light emitting phosphor excited by vacuum ultraviolet light, a blue light emitting phosphor and a red light emitting phosphor, and the light emitting layer is irradiated with vacuum ultraviolet light. A light emitting device comprising: a rare gas discharge lamp comprising: 11. The light emitting device according to claim 9, wherein a light emitting layer including the green light emitting phosphor excited by a vacuum ultraviolet ray, a blue light emitting phosphor and a red light emitting phosphor, and a means for irradiating the light emitting layer with vacuum ultraviolet rays. A light emitting device characterized by being a plasma display panel comprising: