JP2008034302A - Light-emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve green afterglow characteristics in a light-emitting device such as a PDP or the like constituted by using a phosphor, and improve moving picture display performance. <P>SOLUTION: Eu<SP>2+</SP>is used as a green phosphor in the light-emitting center, while a high brightness Eu activated silicate based green phosphor (Ca<SB>1-x</SB>M1<SB>x</SB>)<SB>2-e</SB>MgSi<SB>2</SB>O<SB>7</SB>:Eu<SB>e</SB>in which green afterglow is improved is used to constitute the light-emitting device such as the PDP or the like and the display device. In the formula, M1 is an element of one kind or more selected from a group consisting of Sr and Ba, while x to express composition ratio of the component M1, and e to express the composition ratio of Eu are respectively 0.01≤x≤0.5, and 0.001≤e≤0.2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a light-emitting device, and more particularly to a light-emitting device such as a plasma display panel configured using a phosphor that emits light by being excited by ultraviolet rays, particularly ultraviolet rays in the vacuum ultraviolet region, particularly a Eu (europium) -activated silicate green phosphor. Is.

  In recent years, there has been an increasing demand for a display device typified by a television or a personal computer monitor that is thin and does not require a large installation space. As a device that can be made thin, a plasma display device (PDP (Plasma Display Panel) device), a field emission display (FED) device, and a backlight and a thin liquid crystal panel are combined to form a display device. Liquid crystal display (LCD) devices and the like have been actively developed.

Among them, the PDP device is a display device using a plasma display panel (PDP) as a light emitting device. The plasma display panel (PDP) uses an ultraviolet ray (in the wavelength range of 146 nm and 172 nm when xenon is used as a rare gas) generated in a negative glow region in a minute discharge space containing a rare gas as its excitation source. Luminescence in the visible region is obtained by exciting the phosphor in the phosphor layer disposed in the discharge space and urging the phosphor to emit light. In the PDP device, the amount and color of light emission are controlled and used for display. Therefore, the phosphor is a very important main component for constituting the PDP device. References relating to this type of material and technology include, for example, Japanese Patent Application Laid-Open No. 2004-176010 (Patent Document 1) and “Phosphor Handbook” edited by the Society of Phosphors, 1987, III, Chapter 7, pages 330-335 (Om Corp. Non-patent document 1) ”.
JP 2004-176010 A “Phosphor Handbook” edited by Phosphors Society of Japan Ohmsha 1987 Chapter III Chapter 7 330-335

  In recent years, PDP devices have been recognized for their high performance, and their use as large-sized flat panel displays and thin TVs are rapidly expanding, replacing monitors and televisions (TVs) that use cathode ray tubes. As a result, further improvement in performance has been demanded. Specifically, high brightness to satisfy the display function as a TV, high luminous efficiency to achieve high brightness, and improvement of video characteristics for viewers to enjoy video content such as movies comfortably Is required.

  As the performance of a PDP device is improved, the improvement of its characteristics plays a major role in improving the performance of the design and structure of the device and the members constituting them, particularly the phosphors used. Accordingly, phosphors are required to have improved luminous efficiency and improved response characteristics in light emission.

Conventionally, phosphors of each color of red (R), green (G), and blue (B) are used as phosphors of the surface discharge type color display AC-PDP device. An activated silicate phosphor Zn ₂ SiO ₄ : Mn ²⁺ is used. This Mn-activated silicate phosphor Zn ₂ SiO ₄ : Mn ²⁺ is characterized by excellent luminance and luminous efficiency, but has a problem that afterglow characteristics are inferior to phosphors of other colors. This has recently been pointed out as a problem.

  That the afterglow characteristics are not good means that the afterglow time is long, which means that the previous image and its color remain on the display screen even though the display is switched. . Therefore, when the use of TV is brought into range and the improvement of moving image performance is strongly demanded, such a problem of afterglow that deteriorates the display quality may be a great concern.

  At the same time, in the technical field of PDP devices, in parallel with the study on improving the performance of phosphor materials, the plasma display panel (PDP) structure aimed at improving the light emission efficiency of PDP devices as a high-performance TV device is improved. Consideration is ongoing.

As one of the methods, studies are actively made to increase the composition ratio of Xe gas in the discharge gas containing Ne as a main component and to actively use the generated Xe ₂ molecular beam. Although it is a technology trend of “high xenon concentration” in so-called PDP panels, it is usually considered to achieve higher light emission efficiency of such PDP panels in a composition ratio region higher than the xenon gas composition ratio (about 4%) in the discharge gas. Has been made.

  As a result of this technological development, PDP devices that have become more efficient can be used more and more as flat TV devices that replace TV devices using CRTs instead of simple thin display devices. . The demand for improved image quality, especially video performance, has become increasingly high, and attention has been paid to the afterglow characteristics of phosphors that have not been viewed as problematic in the past. There is a strong demand for improved optical performance.

As a result, in the technological trend of “high xenon concentration” in PDP panels and the trend of TV application expansion of PDP devices, Mn (manganese) activated zinc silicate phosphor Zn ₂ SiO ₄ : Mn ²⁺ with inferior afterglow characteristics As a result, there is a strong demand for a new green phosphor with a short afterglow that can replace a part of the Mn-activated zinc silicate phosphor Zn ₂ SiO ₄ : Mn ^2+. ing.

In that case, the new green phosphor is efficient by the Xe ₂ molecular beam that becomes the main phosphor excitation light source when the PDP panel is made high in xenon concentration, that is, the ultraviolet light having a wavelength of 172 nm, in addition to the ultraviolet light having a wavelength of 146 nm generated by the discharge. The phosphor needs to be well excited and emit light.

  The objective of this invention is providing the light-emitting device provided with the green fluorescent substance excellent in the afterglow characteristic.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  Of the inventions disclosed in the present application, the outline of typical ones will be briefly described as follows.

The present invention is a light-emitting device configured using a discharge gas that generates ultraviolet light by discharge and a phosphor film containing a phosphor that is excited by the ultraviolet light from the discharge gas and emits light.
The discharge gas is a gas comprising Xe gas in an amount such that the composition ratio is 6% or more, preferably 10% or more,
The phosphor is an Eu activated silicate green phosphor represented by the formula (I),

In the formula (I), M1 is one or more elements selected from the group consisting of Sr and Ba, and x indicating the composition ratio of the component M1 and e indicating the composition ratio of Eu are each 0 <x <1, 0.001 ≦ e ≦ 0.2,
A plasma display panel structure is provided.

  Among the inventions disclosed in the present application, effects obtained by typical ones will be briefly described as follows.

The light-emitting device according to the present invention is a new type having a short afterglow in the form of use in which the Mn-activated zinc silicate phosphor Zn ₂ SiO ₄ : Mn ²⁺ inferior in afterglow characteristics is substituted or partially mixed with it. Since the Eu activated silicate green phosphor, which is a green phosphor, is used, excellent afterglow characteristics can be achieved.

  Further, the light emitting device according to the present invention has a good light emission efficiency even under the light excitation condition with the wavelength of 172 nm, which plays a main role as the excitation source in the “high xenon concentration” PDP in addition to the ultraviolet excitation condition with the wavelength of 146 nm. Since the Eu activated silicate green phosphor is used, excellent light emission characteristics can be obtained.

  Moreover, since the display device according to the present invention uses an Eu-activated silicate green phosphor having excellent afterglow characteristics, the light-emitting device that constitutes the display device can realize excellent moving image display.

A conventional green phosphor for PDP is a Mn-activated zinc silicate phosphor Zn ₂ SiO ₄ : Mn ²⁺ , and afterglow characteristics are inferior to phosphors of other colors, and the phosphor emission intensity is reduced to 1/10. The afterglow time defined as the time to decrease is as long as about 10 ms. Therefore, when a PDP device using Mn-activated zinc silicate phosphor Zn ₂ SiO ₄ : Mn ²⁺ increases the efficiency of the discharge gas by increasing the xenon concentration, the TV application mainly for moving image display comes into range. This raises concerns about the afterglow characteristics.

As a result, the moving image display performance of the display device using the light emitting device using the Mn-activated zinc silicate phosphor Zn ₂ SiO ₄ : Mn ²⁺ may not be sufficient.

On the other hand, for other color phosphors, for example, a normal blue phosphor has a short afterglow time of about 1 ms, a short afterglow, and a green Mn-activated zinc silicate phosphor Zn ₂ SiO ₄ : Mn ²⁺ The problem of afterglow similar to phosphors has not been pointed out.

Such a difference in afterglow due to the phosphor is attributed to its composition, particularly the emission center. That is, in the Mn-activated zinc silicate phosphor Zn ₂ SiO ₄ : Mn ²⁺ , the emission center is Mn ²⁺ , and the afterglow time is long and the afterglow characteristic is inferior as a characteristic of the emission center Mn ²⁺ .

On the other hand, in an Eu-activated aluminate phosphor that is a general PDP blue phosphor, for example, BaMgAl ₁₀ O ₁₇ : Eu ²⁺ (hereinafter referred to as BAM), the emission center is Eu ²⁺ , and this light emission As a characteristic of the center Eu ^2+, the afterglow time is short, and there is no particular problem with the afterglow characteristics.

Therefore, it can be understood that the afterglow problem can be reduced if the green phosphor can be improved by changing the emission center from Mn ²⁺ to another element. Specifically, it can be seen that the problem of afterglow can be reduced if Eu ²⁺ can be used as the emission center as in the case of the blue phosphor.

However, there are very few specific examples of a phosphor that emits green light when excited by vacuum ultraviolet rays for PDP with Eu ²⁺ as the emission center. For example, the Eu-activated silicate phosphor Ca ₂ MgSi ₂ O ₇ : Eu ²⁺ is known, but the emission color by ultraviolet excitation is close to yellow rather than green, and there is a problem for PDP in terms of color. is there. That is, it is not possible to construct a beautiful color PDP device.

Therefore, the present inventor refocused on Eu-activated silicate phosphor Ca ₂ MgSi ₂ O ₇ : Eu ²⁺ and tried to improve the composition and synthesize a phosphor material having a new composition.

  As a result, the present inventor has realized a silicate green phosphor capable of obtaining a high luminance under a light excitation condition of a wavelength of 172 nm, and using the silicate green phosphor, a high luminance light emitting device, and thus a display device capable of high luminance display. It was realized.

  The newly realized Eu-activated silicate green phosphor is an Eu-activated silicate green phosphor represented by the following formula (I).

  In the formula (I), M1 is one or more elements selected from the group consisting of Sr and Ba, and x indicating the composition ratio of the component M1 and e indicating the composition ratio of Eu are each 0 <x < 1, 0.001 ≦ e ≦ 0.2.

The inventor of the present invention is based on Eu-activated silicate phosphor Ca ₂ MgSi ₂ O ₇ : Eu ²⁺ , and substitutes a part of Ca element which is a matrix skeleton component of at least one of Sr and Ba. Succeeded in shifting the emission spectrum by vacuum ultraviolet excitation, which is the main phosphor emission characteristic, to the lower wavelength side, and as a result, the emission color when excited by vacuum ultraviolet is green and the color purity is higher. I found out that I can. In the following, the examination and consideration will be described in more detail.

The inventor is an example of a novel Eu-activated silicate green phosphor constituting the present invention (Ca _0.9 Ba _0.1 ) _1.98 MgSi ₂ O ₇ : Eu _0.02 and (Ca _{0. 9} Sr _0.1 ) _1.98 MgSi ₂ O ₇ : Eu _0.02 was newly synthesized, and compared with the conventional Eu-activated silicate phosphor Ca ₂ MgSi ₂ O ₇ : Eu ^2+. Thus, the emission spectrum was measured using a vacuum ultraviolet excimer lamp having a central emission wavelength of 172 nm as a light source according to a conventional method.

FIG. 1 shows a novel Eu-activated silicate green phosphor [(Ca _0.9 Ba _0.1 ) _1.98 MgSi ₂ O ₇ : Eu _0.02 and (Ca _0.9 Sr _{0. 1} ) _1.98 MgSi ₂ O ₇ : Eu _0.02 ] and a conventional phosphor example Ca _1.98 MgSi ₂ O ₇ : Eu _0.02 are emission spectra under a wavelength 172 nm vacuum ultraviolet excitation condition.

By examining the results, as shown in FIGS. 1 and 2, the novel Eu-activated silicic acid of the present embodiment is compared with the emission spectrum of the obtained conventional phosphor Ca _1.98 MgSi ₂ O ₇ : Eu _0.02. It can be seen that all the salt-based green phosphors have the entire emission spectrum shifted to the lower wavelength side.

As a result, as shown in FIG. 2, the chromaticity point in the CIE chromaticity coordinates representing the emission color of the phosphor has an x value and a y value of the conventional phosphor Ca _1.98 MgSi ₂ O ₇ : Eu _{0, respectively.} in _.02 (x, y) = a whereas a _{(0.635,0.585), (Ca 0.9 Ba} 0.1) 1.98 MgSi 2 O 7: Eu 0.02 of x, y The chromaticity value is (x, y) = (0.344, 0.579), and the x, y chromaticity value of (Ca _0.9 Sr _0.1 ) _1.98 MgSi ₂ O ₇ : Eu _0.02 (X, y) = (0.330, 0.593), and it was confirmed that the novel Eu-activated silicate green phosphor of the present embodiment was highly colored as green.

The emission peak intensity of the new Eu-activated silicate-based green phosphor (Ca _0.9 Sr _0.1 ) _1.98 MgSi ₂ O ₇ : Eu _0.02 is the same as that of the conventional phosphor Ca _1.98 MgSi ₂ O. ₇ : It was larger than that of Eu _0.02 , and it was also found that the luminous efficiency was improved.

  Therefore, it was found that the novel Eu-activated silicate green phosphor in which a part of Ca was substituted with Sr or Ba is a more preferable phosphor as a green phosphor for PDP.

  Then, when the emission spectrum was measured in the same manner using a vacuum ultraviolet excimer lamp having a central emission wavelength of 146 nm as a light source, the new Eu-activated silicate green phosphor of this embodiment also has a low emission spectrum as a whole. It turned out that it shifted to the side (refer FIG. 2).

  At this time, the amount of shift of the emission spectrum to the lower wavelength side varies depending on the wavelength of vacuum ultraviolet light that excites the phosphor, and the case where excitation is performed with vacuum ultraviolet light having a wavelength of 172 nm rather than vacuum ultraviolet light having a wavelength of 146 nm. It was also found that the shift amount toward the low wavelength side was large.

Specifically, the peak wavelength of light emission of the conventional Eu-activated silicate phosphor Ca _1.98 MgSi ₂ O ₇ : Eu _{0.02 at} a wavelength of 146 nm under vacuum ultraviolet excitation is 536 nm, and the novel Eu-activated silicate green The phosphor (Ca _0.9 Sr _0.1 ) _1.98 MgSi ₂ O ₇ : Eu _0.02 has a wavelength of 532 nm and is shifted to the 4 nm low wave side. On the other hand, the peak wavelength of emission of the conventional Eu-activated silicate phosphor Ca _1.98 MgSi ₂ O ₇ : Eu _0.02 at a wavelength of 172 nm under vacuum ultraviolet excitation is 536 nm, and the new Eu-activated silicate green phosphor (Ca _0.9 Sr _0.1 ) _1.98 MgSi ₂ O ₇ : Eu _{0.02 under} the same conditions, the emission peak wavelength is 528 nm, which is larger and is found to be shifted to the 8 nm low wave side. It was.

The analysis results of the above emission spectrum are summarized as a table as shown in FIG. FIG. 2 is a table summarizing data obtained by analyzing emission characteristics and emission spectra of a novel Eu-activated silicate green phosphor constituting the present invention and a conventional phosphor example Ca _1.98 MgSi ₂ O ₇ : Eu _0.02. It is.

At this time, the emission peak wavelength of Mn-activated zinc silicate phosphor Zn ₂ SiO ₄ : Mn ²⁺ evaluated by the same method is 528 nm, and the new Eu-activated silicate green phosphor of the present embodiment is equivalent. It turns out that the level is achieved.

  As a result, the new Eu-activated silicate green phosphor according to the present invention has a lower emission spectrum than the conventional phosphor when excited with vacuum ultraviolet light having a wavelength of 172 nm, compared to a wavelength of 146 nm. It has been found that shifts and thus higher color purity can be achieved.

Above the results are silicate phosphor Eu-activated _{Ca 2} MgSi 2 O _7: the ^{Eu 2+} based, a part of Ca element as its host lattice component, of the ionic radius larger Sr and Ba than Ca The present inventor considers replacing at least one of the above. In other words, a situation occurs in which a part of the host crystal has ions larger than the desired size at the position where it should originally exist in the host crystal. Distortion occurs. Then, a new strain in the host crystal affects Eu ²⁺ that is the emission center, and as a result, affects the emission characteristics of the phosphor, and (Ca _0.9 Sr _0.1 ) _1.98 MgSi ₂ O ₇ : Improvement of luminous efficiency at Eu _0.02 or (Ca _0.9 Ba _0.1 ) _1.98 MgSi ₂ O ₇ : Eu _0.02 and (Ca _0.9 Sr _0.1 ) _1.98 MgSi ₂ The present inventor considers that the entire emission spectrum at O ₇ : Eu _0.02 is shifted to the lower wavelength side.

  The inventor believes that the amount of new strain generated in the phosphor host crystal is appropriate, resulting in improved luminous efficiency or better green light emission.

Therefore, in the Eu-activated silicate phosphor Ca ₂ MgSi ₂ O ₇ : Eu ²⁺ , as a method of shifting the emission spectrum particularly by the vacuum ultraviolet excitation to the lower wavelength side, the Ca element which is the matrix skeleton component of Sr and Ba A method of substituting at least one of these is preferred.

In addition, as described above, the method of substituting at least one of Sr and Ba for the Ca element is intended to generate an appropriate strain in the host crystal, and only a part of the Ca element is Sr. And at least one of Ba is preferably substituted. When the amount of substitution with at least one of Sr and Ba for the Ca element is excessively large, there is a concern that the effect of the generated strain becomes dilute. For example, when it is assumed that the Ca element is substituted with Sr, when the Sr element substitution amount exceeds half of the original Ca composition amount and the composition ratio of the Sr component in the obtained phosphor becomes larger than the Ca component, the phosphor May no longer lose the properties of Ca ₂ MgSi ₂ O ₇ : Eu ²⁺ .

Therefore, in order to maintain the characteristics of Ca ₂ MgSi ₂ O ₇ : Eu ²⁺ and achieve better green light emission, the substitution amount of at least one of Sr and Ba follows the notation of the above formula (I). And x ≦ 0.5, which is expressed as a composition ratio of the component M1 and is less than half.

  In addition, regarding the lower limit of the substitution amount of at least one of Sr and Ba with respect to the Ca component, for the purpose of unintentional Ca composition, that is, when the Ca component is contained in the phosphor as an impurity, and for the purpose of improving the light emission performance It prescribes | regulates so that the containing of Ca component may be clearly distinguished.

  Therefore, in the novel Eu-activated silicate green phosphor constituting the present invention, for example, when a high-purity synthetic raw material having a purity of 99.9% or more is used, target composition elements such as Sr and Ba can be contained as impurities. The amount is considered to be on the order of several ppm to several tens of ppm at most (several mg to several tens of mg in 1000 g), and substantially even when synthesizing a small amount of phosphor at a so-called laboratory level of about 10 g. Considering that the lower limit of the amount that can be controlled is about 0.1 mg (10 ppm), and that the molecular weight of the Mg compound and the corresponding Sr or Ba compound corresponding to the Mg compound is at most twice as large. Therefore, the lower limit of the Ca component content is set again.

  That is, in the new Eu-activated silicate green phosphor constituting the present invention, it is assumed that the content of the Sr or Ba component is about 100 ppm or more, and the phosphor according to the above formula (I) is used. Using x indicating the composition ratio of at least one of the components Sr and Ba, the lower limit of x can be set to x = 0.0001.

  And in order to realize a clear distinction, considering that it is clearly distinguished from the case where it is contained unintentionally, and considering that it can be excluded even when a phosphor material with lower purity is used. The lower limit of the content of at least one of Sr and Ba is about 10 times the above value, and according to the notation of the above formula (I), x indicating the composition ratio of at least one of Sr and Ba is The lower limit of x is preferably set to x = 0.001.

  Furthermore, considering the amount that can be contained unintentionally when using a lower purity phosphor material, in order to achieve a clear distinction, the lower limit of the content of at least one of Sr and Ba is set to The lower limit of x is preferably x = 0.01 using x indicating the composition ratio of at least one of Sr and Ba according to the notation of the above formula (I).

  Moreover, about the composition ratio of Eu which is the activator in the novel Eu activated silicate green phosphor according to the present invention, the lower limit is the amount that can sufficiently exert the effect as the emission center, and the decrease in luminous efficiency due to concentration quenching. The upper limit was the amount that could avoid this. That is, regarding the Eu composition ratio, e indicating the composition ratio of Eu is preferably 0.001 ≦ e ≦ 0.2 in accordance with the notation of the above formula (I).

  Regarding the relationship between the composition of the discharge gas in the plasma display panel and the intensity of the ultraviolet rays generated by the discharge, the greater the composition ratio of the contained Xe (xenon) component, the greater the intensity of the vacuum ultraviolet rays emitted by the discharge. It has been found that the proportion of constituents in vacuum ultraviolet light changes.

Specifically, the intensity ratio (I ₁₇₂ / I ₁₄₆ ) of the ultraviolet ray component with a wavelength of 146 nm and the ultraviolet ray component with a wavelength of 172 nm (Xe ₂ molecular beam) contained in the generated vacuum ultraviolet ray changes due to the change in the composition ratio of Xe in the discharge gas. That is, it is known that the intensity ratio (I ₁₇₂ / I ₁₄₆ ) increases as the Xe composition ratio increases.

FIG. 3 is a graph showing the relationship between the Xe composition ratio (%) in the discharge gas and the intensity ratio (I ₁₇₂ / I ₁₄₆ ) in the AC type PDP.

As a result of the study, in the AC type PDP, when the Xe composition ratio is 4%, I ₁₇₂ / I ₁₄₆ (4%) = 1.2, and in the normal specification PDP where the Xe composition ratio is 1 to 4%, it is generated by discharge It is known that the intensity ratio of the ultraviolet component having a wavelength of 146 nm and the ultraviolet component having a wavelength of 172 nm contained in the vacuum ultraviolet ray is equal to or slightly lower than the intensity of the 172 nm component. As a result of further investigation, when the Xe composition ratio is 6%, the intensity of the vacuum ultraviolet rays generated by the discharge increases and I ₁₇₂ / I ₁₄₆ (6%) = 1.9, and the Xe composition ratio increases significantly to 1.9. The intensity of the vacuum ultraviolet rays generated increases as I ₁₇₂ / I ₁₄₆ (10%) = 3.1, and when the Xe composition ratio is 12%, the intensity of the vacuum ultraviolet rays generated by the discharge increases and I ₁₇₂ / I. ₁₄₆ (12%) = 3.8 was found to be significantly large.

  Therefore, the Xenon-compatible PDP having a larger Xe composition ratio in the discharge gas than the normal-specification PDP, for example, 6% Xe composition ratio, emits light with better characteristics with respect to 172 nm vacuum ultraviolet rays. The use of a phosphor is preferable, and when the composition ratio exceeds 6% and the Xe composition ratio is higher than 10%, the demand for the phosphor becomes greater.

Therefore, when the Eu-activated silicate green phosphor represented by the above formula (I) is used in a plasma display panel using a discharge gas containing an Xe composition, the phosphor is favorable by excitation of light having a wavelength of 172 nm. Since the emission characteristics can be obtained, the generated Xe ₂ molecular beam can be used effectively, and a high-performance PDP device can be provided.

Furthermore, the Eu-activated silicate green phosphor of the above formula (I) has, for example, a Xe composition ratio of 6% or more, more preferably a strong 172 nm ultraviolet component intensity ratio to a 146 nm component (Xe ₂ molecular beam is positive) It is well adapted to the technology of so-called “PDP for high xenon concentration”, which uses discharge gas containing Xe gas in an amount that makes Xe composition ratio 10% or more. A higher performance light emitting device can be configured in a PDP using the discharged gas.

  Based on the above, the PDP according to the embodiment of the present invention using the Eu activated silicate green phosphor represented by the above formula (I) can be configured as follows.

  FIG. 4 is an exploded perspective view showing a main part of the structure of the PDP according to the present embodiment. 5, 6 and 7 are cross-sectional views of the main part showing the structure of the PDP according to the present embodiment.

  A PDP 100 according to an embodiment of the present invention has a structure to cope with so-called counter discharge, a pair of substrates 1 and 6 that are spaced apart from each other, and a pair of substrates that are provided on the substrate 6. When the substrates 1 and 6 are stacked, the partition wall 7 that keeps the distance between the substrate 1 and the substrate 6 and the space formed between the pair of substrates 1 and 6 are sealed and generate ultraviolet rays by discharge. Discharge gas (not shown) and electrodes 2 and 9 disposed on opposing surfaces of the pair of substrates 1 and 6 are provided. 5 shows one section along the direction in which the electrode 2 extends, FIG. 6 shows another section along the direction in which the electrode 2 extends, and FIG. A cross section along the extending direction of the electrode 9 is shown.

  Then, the Eu activated silicate green phosphor represented by the above formula (I) constitutes the phosphor layer 10 on one of the pair of substrates 6 and the surface of the partition wall 7. Then, the Eu activated silicate green phosphor represented by the above formula (I) constituting the phosphor layer 10 is excited by vacuum ultraviolet rays having a wavelength of 146 nm and 172 nm generated from the discharge gas by discharge, and emits visible light. It is characterized by being comprised.

  4, 6, and 7 is a bus line 3 made of silver or Cu—Cr that is integrated with the electrode 2 to reduce the electrode resistance. The layers 4 and 8 are dielectric layers 4 and 8, and the layer 5 is a protective film 5 provided for electrode protection.

  Hereinafter, examples corresponding to the best mode for carrying out the present invention will be described.

  In order to produce a PDP which is an example according to the present invention, an Eu-activated silicate green phosphor, which is a main component of the present invention, was first synthesized.

The composition formula of the phosphor synthesized first is (Ca _0.9 Sr _0.1 ) _1.98 MgSi ₂ O ₇ : Eu _0.02 .

First, 1.784 g (17.82 mmol) of CaCO ₃ , 0.292 g (1.98 mmol) of SrCO ₃ , 0.962 g (10.00 mmol) of MgCO _3, and 1.322 g (22.22) of SiO ₂ were synthesized. 00 mmol), 0.0352 g (0.100 mmol) of Eu ₂ O ₃ and 0.0160 g (0.300 mmol) of NH ₄ Cl as a melting aid were weighed out and mixed well in an agate mortar.

  Thereafter, the obtained mixture was filled in a heat-resistant container and baked in the atmosphere at 600 ° C. for 2 hours, and then baked in a reducing atmosphere at 1200 ° C. for 3 hours. The obtained fired product was pulverized, washed with water and dried to obtain a silicate phosphor having the above composition.

Next, a phosphor (Ca _0.9 Ba _0.1 ) _1.98 MgSi ₂ O ₇ : Eu _0.02 was synthesized.

The synthesis was the same as described above, with 1.784 g (17.82 mmol) of CaCO ₃ , 0.391 g (1.98 mmol) of BaCO ₃ , 0.962 g (10.00 mmol) of MgCO ₃ , and 1 of SiO ₂ . 322 g (22.00 mmol), 0.0352 g (0.100 mmol) of Eu ₂ O ₃ and 0.0160 g (0.300 mmol) of NH ₄ Cl as a melting aid were each weighed in a mortar made of agate Mixed.

  Thereafter, the obtained mixture was filled in a heat-resistant container and baked in the atmosphere at 600 ° C. for 2 hours, and then baked in a reducing atmosphere at 1200 ° C. for 3 hours. The obtained fired product was pulverized, washed with water and dried to obtain a silicate phosphor having the above composition.

Next, a conventional phosphor Ca _1.98 MgSi ₂ O ₇ : Eu _0.02 was synthesized as a comparative example.

The synthesis is the same as above, 1.982 g (19.80 mmol) of CaCO ₃ , 0.962 g (10.00 mmol) of MgCO ₃ , 1.322 g (22.00 mmol) of SiO ₂ , Eu ₂ O ₃ 0.0352 g (0.100 mmol) and 0.014 g (0.300 mmol) of NH ₄ Cl as a melting aid were weighed out and mixed well in an agate mortar. Thereafter, the obtained mixture was filled in a heat-resistant container and baked in the atmosphere at 600 ° C. for 2 hours, and then baked in a reducing atmosphere at 1200 ° C. for 3 hours. The obtained fired product was pulverized, washed with water and dried to obtain a silicate phosphor having the above composition as a comparative example.

Next, a phosphor (Ca _0.9 Sr _0.1 ) _1.98 MgSi ₂ O ₇ : Eu _0.02 and a phosphor (using a vacuum ultraviolet excimer lamp having a central emission wavelength of 172 nm as a light source according to a conventional method The emission spectrum of Ca _0.9 Ba _0.1 ) _1.98 MgSi ₂ O ₇ : Eu _0.02 was measured. As a comparative example, the emission spectrum of the Ca _1.98 MgSi ₂ O ₇ : Eu _0.02 was also measured. The results are shown in FIG.

As described above, the phosphor (Ca _0.9 Sr _0.1 ) _1.98 MgSi ₂ O ₇ : Eu _0.02 and the phosphor (Ca _0.9 Ba _0.1 ) _{1.98 shown in FIG.} MgSi ₂ O _7: emission spectrum of _{Eu 0.02} is phosphor _Ca 1.98 MgSi ₂ O _7: comparison with the emission spectrum of _{Eu 0.02,} both the entire emission spectrum is shifted to a lower wavelength side I understood.

Similarly, a phosphor (Ca _0.9 Sr _0.1 ) _1.98 MgSi ₂ O ₇ : Eu _0.02 , phosphor (Ca ₀ ) according to a conventional method using a vacuum ultraviolet excimer lamp having a central emission wavelength of 146 nm as a light source. _.9 Ba _0.1 ) _1.98 MgSi ₂ O ₇ : Eu _0.02 and phosphor Ca _1.98 MgSi ₂ O ₇ : Eu _0.02 were measured for emission spectra.

The evaluation of light emission characteristics and the analysis results are summarized in the table shown in FIG. When the emission spectrum was measured using vacuum ultraviolet rays having emission wavelengths of 146 nm and 172 nm, the phosphor (Ca _0.9 Sr _0.1 ) _1.98 MgSi ₂ O ₇ : Eu _0.02 and the phosphor (Ca _0.9 Ba _0.1 ) _1.98 MgSi ₂ O ₇ : Eu _0.02 has a lower emission wavelength than the phosphor Ca _1.98 MgSi ₂ O ₇ : Eu _0.02 whose entire emission spectrum is a comparative example. I found out that it was shifting.

  The shift of the emission spectrum to the lower wavelength side varies depending on the wavelength of vacuum ultraviolet light that excites the phosphor sample, and the lower wavelength side when excited by vacuum ultraviolet light having a wavelength of 172 nm than vacuum ultraviolet light having a wavelength of 146 nm. I also found that the shift to

From the above, the phosphor (Ca _0.9 Sr _0.1 ) _1.98 MgSi ₂ O ₇ : Eu _0.02 and the phosphor (Ca _0.9 Ba _0.1 ) _1.98 MgSi ₂ O ₇ : Eu _{0 .02} is used in a PDP using a discharge gas containing a Xe composition, high light emission can be obtained by excitation of ultraviolet light with wavelengths of 146 nm and 172 nm, so that the Xe ₂ molecular beam by discharge can also be used with high efficiency. Thus, it has been found that a high-luminance PDP device is possible.

Furthermore, the phosphor (Ca _0.9 Sr _0.1 ) _1.98 MgSi ₂ O ₇ : Eu _0.02 and the phosphor (Ca _0.9 Ba _0.1 ) _1.98 MgSi ₂ O ₇ : Eu _{0. 02} is a so-called “use of a discharge gas containing Xe gas in an amount of, for example, a composition ratio of 6% or more, more preferably a composition ratio of 10% or more in which Xe ₂ molecular beams are actively used. It was found that a light-emitting device capable of emitting good green light can be constructed even in a PDP using a high xenonized discharge gas, which is well adapted to the “high xenon-compatible PDP” technology.

Next, the silicate phosphor (Ca _0.9 Sr _0.1 ) _1.98 MgSi ₂ O ₇ : Eu _0.02 is used as the green phosphor constituting the green phosphor layer, and is shown in FIG. A PDP 100 which is a light emitting device was manufactured.

  In the PDP 100 of the surface discharge type color PDP apparatus as in the present embodiment, for example, a negative voltage is applied to one of the pair of display electrodes (electrode 2) (generally referred to as a scan electrode) and the address electrode (electrode 9). A discharge is generated by applying a positive voltage (positive voltage compared to the voltage applied to the display electrode) to the other remaining display electrode (electrode 2). A wall charge is formed to assist in starting the discharge (referred to as writing). When an appropriate reverse voltage is applied between the pair of display electrodes in this state, a discharge is generated in the discharge space between the electrodes 2 via the dielectric layer 4 (and the protective film 5).

  When the voltage applied to the pair of display electrodes (electrode 2) is reversed after the discharge is completed, a new discharge is generated. By repeating this, a discharge is continuously generated (this is called a sustain discharge or a display discharge).

  In the PDP 100 according to this embodiment, an address electrode (electrode 9) made of silver or the like and a dielectric layer 4 made of a glass-based material are formed on a rear substrate (substrate 6). The partition wall 7 made of a glass-based material is printed on a thick film, and the partition 7 is formed by blast removal using a blast mask.

  Next, red, green and blue phosphor layers 10 are sequentially formed in stripes on the barrier ribs 7 so as to cover the groove surfaces between the corresponding barrier ribs 7.

  Here, each phosphor layer 10 corresponds to red, green and blue, and 40 parts by weight of red phosphor particles (60 parts by weight of vehicle) and 40 parts by weight of green phosphor particles (60 parts by weight of vehicle). And 35 parts by weight of the blue phosphor particles (65 parts by weight of the vehicle), mixed with the vehicle to form a phosphor paste, applied by screen printing, and then evaporated and evaporated of the volatile components in the phosphor paste. It is formed by burning off organic matter. The phosphor layer 10 used in this example is composed of each phosphor particle having a median particle diameter of about 3 μm.

As for the phosphor materials other than green, the red phosphor is a mixture of (Y, Gd) BO ₃ : Eu phosphor and Y ₂ O ₃ : Eu phosphor 1: 1, and the blue phosphor is BAM. It is a (BaMgAl ₁₀ O ₁₇ : Eu ²⁺ ) phosphor.

  Next, the front substrate (substrate 1) on which the display electrode (electrode 2), bus line 3, dielectric layer 4 and protective film 5 are formed and the rear substrate (substrate 6) are frit-sealed, and the inside of the panel is vacuumed After exhausting, discharge gas is injected and sealed. The discharge gas is a gas that includes xenon (Xe) gas in an amount that results in a composition ratio of 10%. The PDP 100 according to this embodiment has a size of 3 type and a pitch of one pixel of 1000 μm × 1000 μm.

  Next, a plasma display which is a display device configured to display an image using the PDP using the silicate phosphor according to the embodiment of the present invention in combination with a driving circuit for driving the PDP. A device was made.

  This plasma display device has high luminance, excellent display performance, and high luminance display. When the afterglow characteristics of green were evaluated, the afterglow time was as short as about 1 ms, which was equivalent to the characteristics of the blue phosphor (BAM) used in the same plasma display device.

As a result, a conventional plasma display device using a conventional Mn-activated zinc silicate phosphor (Zn ₂ SiO ₄ : Mn ²⁺ ) had a problem. Occurrence of a phenomenon that remains on the display screen can be sufficiently suppressed, and an excellent moving image display can be realized.

In the PDP according to the present invention, a novel Eu-activated silicate green phosphor constituting the present invention is used, and an Mn-activated zinc silicate phosphor (Zn ₂ SiO ₄ : Mn ²⁺ ) having inferior afterglow characteristics is used. It is also possible to constitute a PDP having excellent afterglow characteristics in a form of use in which a part of the green phosphor is mixed and mixed.

In that case, the mixing ratio is (new Eu-activated silicate green phosphor) / (Zn ₂ SiO ₄ : Mn ²⁺ ) ≧ 1, that is, the new Eu-activated silicate green phosphor constituting the present invention is more than half. It is desirable to use at a mixing ratio. The afterglow time of Zn ₂ SiO ₄ : Mn ²⁺ is about 10 ms, and the new Eu-activated silicate green phosphor constituting the present invention is about 1 ms. Can be suppressed to about 5 ms or less, and the phenomenon that the green color remains on the display screen after the display switching described above can be reduced to the extent that the viewer does not care.

  Moreover, although the detailed examination result is not shown about red and blue fluorescent substance in a present Example, PDP can be similarly produced also with the fluorescent substance of each composition shown below.

In the red phosphor, one or more phosphors of (Y, Gd) BO ₃ : Eu, (Y, Gd) ₂ O ₃ : Eu, and (Y, Gd) (P, V) O ₄ : Eu are used. It is possible to include. In the blue phosphor, one or more selected from the group consisting of CaMgSi ₂ O ₆ : Eu, Ca ₃ MgSi ₂ O ₈ : Eu, Ba ₃ MgSi ₂ O ₈ : Eu, and Sr ₃ MgSi ₂ O ₈ : Eu. Of blue phosphors. Furthermore, combinations with phosphors not shown here are also applicable.

  The invention made by the present inventor has been specifically described based on the embodiments and examples. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. Needless to say.

  The light-emitting device of the present invention is capable of high-performance moving image display based on a phosphor material having high luminance and short afterglow, and is required to have high luminance by forming a larger light-emitting device. It can be applied to large-sized flat panel display devices for home use where characteristics are essential.

It is explanatory drawing which shows the emission spectrum in the wavelength 172nm vacuum ultraviolet-ray excitation condition in the novel Eu activation silicate type | system | group green fluorescent substance of the light-emitting device which is one embodiment of this invention, and the conventional fluorescent substance. It is the table | surface which put together the data which analyzed the emission characteristic and emission spectrum in the novel Eu activation silicate type | system | group green fluorescent substance of the light-emitting device which is one embodiment of this invention, and the conventional fluorescent substance. It is a graph which shows the relationship between Xe composition ratio (%) in discharge gas in an AC type PDP, and intensity ratio ( _I172 / _I146 ). It is a principal part disassembled perspective view which shows the structure of the plasma display panel which is the light-emitting device of one embodiment of this invention. It is principal part exploded sectional drawing which shows the structure of the plasma display panel which is the light-emitting device of one embodiment of this invention. It is principal part exploded sectional drawing which shows the structure of the plasma display panel which is the light-emitting device of one embodiment of this invention. It is principal part exploded sectional drawing which shows the structure of the plasma display panel which is the light-emitting device of one embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,6 Substrate 2,9 Electrode 3 Bus line 4,8 Dielectric layer 5 Protective film 7 Partition 10 Phosphor layer 100 PDP

Claims (4)

A light-emitting device configured using a discharge gas that generates ultraviolet light by discharge and a phosphor film containing a phosphor that emits light by being excited by ultraviolet light from the discharge gas,
The discharge gas is a gas that includes Xe gas in an amount such that the composition ratio is 6% or more,
The phosphor is an Eu activated silicate green phosphor represented by the formula (I),

In the formula (I), M1 is one or more elements selected from the group consisting of Sr and Ba, and x indicating the composition ratio of the component M1 and e indicating the composition ratio of Eu are each 0 <x <1, 0.001 ≦ e ≦ 0.2,
A light-emitting device comprising a plasma display panel structure. The light-emitting device according to claim 1.
The phosphor film includes a Zn ₂ SiO ₄ phosphor activated with Mn ²⁺ together with the Eu activated silicate green phosphor represented by the formula (I). In the light-emitting device as described in any one of Claims 1-2,
The light emitting device according to claim 1, wherein the discharge gas is a gas containing Xe gas in an amount such that the composition ratio is 10% or more. In the light-emitting device as described in any one of Claims 1-3,
A pair of substrates that are spaced apart from each other, a partition wall that is provided between the pair of substrates and maintains a distance between the pair of substrates, and is enclosed in a space formed between the pair of substrates, and ultraviolet rays are discharged by discharge. A discharge gas that generates a gas, and an electrode disposed on at least one of the opposing surfaces of the pair of substrates,
The Eu-activated silicate green phosphor represented by the formula (I) is contained, and constitutes a phosphor layer on at least one of the pair of substrates and at least one of the surfaces of the partition walls. And
A light-emitting device configured to emit light by exciting the Eu-activated silicate green phosphor by ultraviolet rays generated from the discharge gas by discharge.

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