KR20060108632A - Light-emitting device - Google Patents

Abstract

Disclosed is a light-emitting device (1) comprising a light-emitting layer (2) containing a phosphor and at least two electrodes (6, 7). The light-emitting device (1) also comprises at least two electrically insulating layers (2, 9) having different dielectric constants, and one of the electrically insulating layers (2, 9) is the light-emitting layer (2). Either one of the electrodes (6, 7) is formed in contact with one of the insulating layers. Consequently, a light-emitting device which is capable of emitting a light by utilizing surface discharge can be produced at low cost. The light-emitting device has a good luminous efficiency, and the power consumption can be low when a large-screen display is produced using this light-emitting device.

Description

Light-Emitting Element {LIGHT-EMITTING DEVICE}

The present invention relates to a light emitting device. In particular, it is related with the light emitting element which comprises the unit pixel of the large screen display of simple structure, easy manufacture, and low power consumption.

In recent years, liquid crystal displays and plasma displays have been widely used as large-sized flat displays, but developments in pursuit of higher quality and higher efficiency displays have been conducted. Candidates for such a display include an electro luminescence display (ELD) or a field emission display (FED). Non-patent document 1 describes an ELD as follows substantially. The former is based on a structure in which an electric field is applied to a phosphor, which is a light emitting layer, through an insulating layer, and a dispersion type and a thin film type are known. The dispersion type has a structure in which ZnS particles to which impurity Cu and the like are added are dispersed in an organic binder, an insulating layer is formed thereon, and sandwiched by upper and lower electrodes. The impurity forms a pn junction in the phosphor particles, and when an electric field is applied, electrons emitted by the high electric field generated on the junction surface are accelerated, and then recombine with holes to emit light. The latter has a structure in which a thin film of phosphor such as Mn dope ZnS, which is a light emitting layer, arranges electrodes through an insulator layer. The presence of the insulator layer makes it possible to apply a high electric field to the light emitting layer, and the emitted electrons accelerated in the electric field excite the emission center and emit light. On the other hand, FED has a structure which consists of an electron emitting element and the fluorescent substance which opposed this in the vacuum container, and accelerates the electron emitted in the vacuum from the electron emitting element, and irradiates a fluorescent substance layer to light-emit.

In any device, since electron emission is an opportunity for light emission, a technique for emitting electrons with low voltage and high efficiency is important. As such a technique, attention has been paid to electron emission by polarization reversal of a steel dielectric. For example, in the following non-patent document 2, as shown in FIG. 20, the PZT ceramic 31 which has the planar electrode 32 provided in one side and the lattice-shaped electrode 33 provided in the other side is vacuum-contained. It is proposed that electrons are emitted by opposing the platinum electrode 34 through the grid electrode 35 and applying a pulse voltage between the electrodes in 36. 37 is an exhaust port. According to the proposal, the pressure in the vessel is 1.33 Pa (10 ⁻² Torr), and it is described as not discharging at atmospheric pressure.

Although electrons emitted by polarization reversal of a steel dielectric are accelerated in a vacuum container to emit a phosphor layer or a display using the light emission is described in Patent Document 1 and Patent Document 2 below, however, the basic configuration is non-patent. Instead of the platinum electrode of Document 2, a phosphor layer is made to emit light by the structure used as an electrode which has a phosphor layer.

On the other hand, the light emitting element which used the emission electron by polarization reversal of a steel dielectric in non-vacuum is disclosed as the electroluminescent surface light source element by following patent document 3, for example. As shown in FIG. 21, the element includes a lower electrode 42, a steel dielectric thin film 41, an upper electrode 43, a carrier multiplication layer 48, and a light emitting layer on the substrate 45. 44, and the transparent electrode 46 is formed in order, and the upper electrode has an opening 47. By inverting the applied voltage pulse between the lower electrode and the upper electrode, electrons are emitted from the upper electrode opening to the carrier multiplication layer and accelerated by a positive voltage applied to the transparent electrode to reach the light emitting layer while multiplying the electrons. It emits light. It is described that the carrier multiplication layer is composed of a semiconductor having a relatively low dielectric constant and a band gap that does not absorb the emission wavelength emitted from the light emitting layer. This element can be thought of as a kind of ELD. Further, Patent Document 4 discloses a structure in which one insulator is made of a steel dielectric thin film in a configuration in which a light emitting layer made of a phosphor formed by sputtering is sandwiched with an insulating layer at the front and back to apply a pulsed electric field.

Patent Document 1: Japanese Patent Application Laid-Open No. 07-64490

Patent Document 2: US Patent No. 5453661

Patent Document 3: Japanese Patent Application Laid-Open No. 06-283269

Patent Document 4: Japanese Patent Application Laid-Open No. 08-083686

[Non-Patent Document 1] 松本 正 一, Electronic Display, Omsa, July 7, 1995, p113-125.

[Non-Patent Document 2] Other than Jun-ichi Asano, 'Field-Exited'

ElectronEmissionfromFerroelectricCeramic in Vacuum’Japanese Journa1 of Applied PhysicsVol.31Partlp.3098-3101, Sep / 1992

In the above prior art, requiring a vacuum state has a problem that the structure is complicated and the screen is very difficult to display. For example, field emission displays (FEDs) can expect high luminous efficiency, but require a vacuum vessel that maintains a high degree of vacuum for emitting electron beams. For this reason, the structure of a display becomes complicated and it is thought that implementation of a large screen structure is difficult. There is no product yet for FED.

In addition, there is a plasma display that does not require a vacuum container. The plasma display converts the discharge energy into ultraviolet light energy once, and the ultraviolet light emits light by exciting the light emitter. In the process of exciting a fluorescent substance, this ultraviolet light has a lot of absorption by members other than fluorescent substance, Therefore, it is difficult to raise luminous efficiency, and there exists a problem that power consumption at the time of a large screen display is large.

Similarly, there are ELs in displays that do not require a vacuum container. Inorganic ELs have problems in luminous efficiency, color reproducibility, etc., and organic EL uses a thin film forming process used for manufacturing a liquid crystal display. There is a problem that becomes. In addition, large screens are difficult, and it is not yet known to be commercialized.

The light emitting element of the present invention is a light emitting element comprising a phosphor and a light emitting element comprising at least two electrodes, the light emitting element comprising at least two kinds of electrical insulator layers having different dielectric constants, One is the said light emitting layer, The electrode of any one of the said two electrodes is formed in contact with any of the said insulator layers, It is characterized by the above-mentioned.

According to the light emission principle of the present invention, dielectric breakdown occurs between at least two electrodes to generate primary electrons (e-), and the primary electrons (e-) collide with the phosphor particles of the light emitting layer to form a creepage surface. ) And many secondary electrons (e-) generate | occur | produce, and, as a result, the electrons or ultraviolet rays which generate | occur | produce in the avalanche collide with the emission center of a fluorescent substance, and fluorescent substance particles are excited and emit light.

1 is a cross-sectional view of a light emitting device according to Embodiment 1 of the present invention;

2 is a view for explaining a manufacturing step of the light emitting device according to the first embodiment of the present invention;

3 is a view for explaining a manufacturing step of the light emitting device according to the first embodiment of the present invention;

4 is a view for explaining a manufacturing step of the light emitting device according to Embodiment 1 of the present invention;

5 is a view for explaining a manufacturing step of the light emitting device according to the first embodiment of the present invention;

6 is an enlarged schematic view of a cross section of the porous light emitting layer according to the first embodiment of the present invention;

7 is a sectional view of a light emitting device according to Embodiment 2 of the present invention;

8 is a sectional view of a light emitting device according to Embodiment 3 of the present invention;

9 is a sectional view of a light emitting element according to Embodiment 4 of the present invention;

10 is a view for explaining a manufacturing step of the light emitting device according to the fourth embodiment of the present invention;

11 is a view for explaining a manufacturing step of the light emitting device according to the fourth embodiment of the present invention;

12 is a view for explaining a manufacturing step of the light emitting device according to the fourth embodiment of the present invention;

13 is a view for explaining a manufacturing step of the light emitting device according to the fourth embodiment of the present invention;

14 is a schematic diagram showing an enlarged cross section of the porous light emitting layer according to the fifth embodiment of the present invention;

15 is a schematic diagram showing an enlarged cross section of the porous light emitting layer according to the fifth embodiment of the present invention;

16 is an exploded perspective view of a light emitting element according to Embodiment 6 of the present invention;

17 is an explanatory diagram showing an operation function of light emission in Embodiment 1 of the present invention;

18 is a sectional view of a light emitting element according to Embodiment 7 of the present invention;

19 is a sectional view of a light emitting element according to Embodiment 8 of the present invention;

20 is a sectional view of a light emitting device of a conventional example in Non-Patent Document 2;

21 is a sectional view of a light emitting element of a conventional example in Patent Document 3;

Fig. 22 is a sectional view of a light emitting device according to Embodiment 9 of the present invention;

23 is a sectional view of a light emitting element according to Embodiment 10 of the present invention;

24 is a sectional view of a light emitting element according to Embodiment 11 of the present invention;

25 is a sectional view of a light emitting device according to a twelfth embodiment of the present invention;

Fig. 26 is a sectional view of a light emitting element in accordance with Embodiment l3 of the present invention;

27 is a sectional view of a light emitting element according to Embodiment 14 of the present invention;

28 is a sectional view of a light emitting device according to Embodiment 15 of the present invention;

29 is a sectional view of a light emitting device according to Embodiment 16 of the present invention;

30A-F are cross-sectional views illustrating a method of manufacturing the light emitting device shown in FIG. 29;

31 is a sectional view of a light emitting element according to Embodiment 17 of the present invention;

32A-G are cross-sectional views illustrating a method of manufacturing the light emitting device shown in FIG. 31;

33 is a sectional view of a light emitting element according to Embodiment 18 of the present invention;

34A-C are cross-sectional views illustrating a method of manufacturing the light emitting device shown in FIG. 33;

35 is a sectional view of a light emitting element in a nineteenth embodiment of the present invention;

36A to 36D illustrate a process stage for explaining the manufacturing method of the light emitting device shown in FIG. 35;

37A-C are cross-sectional views illustrating a method for manufacturing an electron emitter in accordance with a twentieth embodiment of the present invention;

38 is a cross-sectional view of a porous light emitting body constituting a light emitting element according to Embodiment 21 of the present invention;

39 is a cross sectional view of a porous light-emitting body that constitutes a light-emitting element in Embodiment 21 of the present invention;

40 is a cross sectional view of a porous light-emitting body that constitutes a light-emitting element in Embodiment 21 of the present invention;

Fig. 41 is a schematic diagram of a cross section of a porous light emitting body constituting the light emitting element according to Embodiment 21 of the present invention.

FIG. 42 is a schematic view of a cross section of a porous light emitting body constituting a light emitting element according to Embodiment 21 of the present invention; FIG.

Fig. 43 is an exploded perspective view of an essential part of the field emission display in the twenty-second embodiment of the present invention;

44 is a cross sectional view of a light emitting element alignment in Embodiment 22 of the present invention;

45A-C are sectional views of the light emitting element alignment in Embodiment 23 of the present invention.

The light emitting device of the present invention includes at least a first electrode, a dielectric layer, a porous light emitting layer, and a second electrode on the back side, and forms a gap between the porous light emitting layer and the electrode. Accordingly, when an alternating electric field is applied between the first electrode and the second electrode, insulation breakdown of the gas occurs in the gap, thereby facilitating the generation of primary electrons. By these primary electrons, creepage discharge occurs in the porous light emitting layer between electrodes, and secondary electrons or ultraviolet rays are emitted. The emitted secondary electrons or ultraviolet rays emit light by exciting the emission center of the porous light emitting layer.

Although the said gap can be arbitrarily made, it is preferable to set in the range of 1 micrometer or more and 300 micrometers or less. If it is less than 1 micrometer, it will become difficult to control a clearance, and when it exceeds 300 micrometers, it will become difficult to produce insulation breakdown. In general, the dielectric breakdown of air in the atmosphere is 3 kV / mm, and it is necessary to apply an electric field of 300 V or more (with a gap of 100 µm). Decompression will cause dielectric breakdown below 300V, while applying high voltage will damage various parts of the cell structure. Therefore, the range of the above intervals is preferable to apply a voltage such that damage does not occur. As for the said space | gap, 10 micrometers or more and 100 micrometers or less are more preferable.

The light emitting device of the present invention is light emission by creeping discharge in the porous light emitting layer, and since the formation of the porous light emitting layer does not require a thin film forming process, a vacuum system, a carrier multiplication layer, etc., the structure is simple and the manufacturing is easy. In addition, the luminous efficiency is good, and the power consumption at the time of producing a large display is relatively small. In addition, the light emitting device of the present invention may form a discharge separating means between the porous light emitting layers, thereby avoiding cross talk during light emission. Here, crosstalk refers to a phenomenon in which light emission between certain pixels and adjacent pixels affects each other, thereby decreasing luminous efficiency.

It is preferable that especially the discharge separation means of this invention forms and forms a partition and / or space. The partition wall separating the porous light emitting layer is preferably an electrical insulator having a thickness of 80 to 300 µm.

When using as a partition, it is preferable to form with an inorganic material. As the inorganic material, glass, ceramics, dielectrics or the like can be used. Dielectrics include Y ₂ O ₃ , Li ₂ O, MgO, CaO, BaO, SrO, Al ₂ O ₃ , SiO ₂ , MgTiO ₃ , CaTiO ₃ , BaTiO ₃ , SrTiO ₃ , ZrO ₂ , TiO ₂ , B ₂ O ₃ , PbTiO ₃ , PbZrO ₃ , PbZrTiO ₃ (PZT), and the like.

When making it a space | gap as said discharge separation means, it is preferable to make space | gap distance into 80-300 micrometers.

The gap between the porous light emitting layer and the second electrode may be divided in the thickness direction by a rib. This is because the generation of electrons due to dielectric breakdown is likely to occur on the wall surface of the rib. The preferred material of the rib can be selected from the same material as that of the partition wall. The surface of the ribs and partitions is preferably as smooth as possible. If it is a smooth surface, the generated electrons will be easy to hop through a rib, and the luminous efficiency of a porous light emitting layer can be improved.

It is preferable that the atmosphere in the said light emitting element is at least 1 chosen from air | atmosphere, oxygen, nitrogen, and a noble gas.

It is preferable that the atmosphere of the said light emitting element contains at least 1 selected from the said gas decompressed.

It is preferable that the said porous light emitting layer emits red (R), green (G), or blue (B) at least.

It is preferable that the said porous light emitting layer is formed from the fluorescent substance particle which has an insulating layer on the surface.

It is preferable that the said porous light emitting layer is formed from fluorescent substance particle | grains and insulating fiber.

It is preferable that the said porous light emitting layer is formed from fluorescent substance particle | grains and insulating fiber which have an insulating layer on the surface.

The apparent porosity of the porous light emitting layer is preferably in the range of 10% or more and less than 100%. In order to hop electrons in the porous light emitting layer (a collection of phosphor particles and gaps), it is required that the voids between the individual phosphor particles are shorter than the average free stroke of the electrons, and the hopping of the electrons is not inhibited within this range.

Preferably, the first or second electrode is an address electrode or a display electrode.

It is preferable that the said 2nd electrode is a transparent electrode, and is arrange | positioned at the observation surface side.

The light emitting device of the present invention is a light emitting device comprising a dielectric layer, a porous light emitting layer, a pair of electrodes, and another electrode, wherein the porous light emitting layer comprises inorganic phosphor particles, and the pair of electrodes comprises an electric field on at least part of the dielectric layer. Is arranged to be applied, and the other electrode is arranged such that an electric field is applied to at least a portion of the porous light emitting layer between the other electrode and at least one of the pair of electrodes. That is, for example, it is a multi-terminal light emitting element such as a three-terminal light emitting element. With the above configuration, when an electric field for polarization inversion is applied between a pair of electrodes, firstly, primary electrons are emitted by polarization inversion from the dielectric layer. Thereafter, an alternating electric field is applied between the other electrode and at least one of the pair of electrodes, so that the emitted primary electrons are continually surface discharged in the porous light emitting layer to generate secondary electrons. Finally, a large amount of secondary electrons excite the emission center to emit light of the porous light emitting layer.

The pair of electrodes may be disposed in the dielectric layer. One of the pair of electrodes may be disposed at the boundary between the dielectric layer and the porous light emitting layer, and the other may be disposed at the dielectric layer. In addition, the electrode of that excepting the above may be arrange | positioned to a porous light-emitting body layer. The pair of electrodes may be formed along the boundary between the dielectric layer and the porous light emitting layer. The pair of electrodes may be formed at the boundary between the dielectric layer and the porous light emitting layer. In addition, one of the pair of electrodes may be formed at the boundary between the dielectric layer and the porous light emitting layer, and the other electrode may be formed in the dielectric layer.

The porous light emitting layer may be composed of continuous fine pores leading to the surface of the porous light emitting layer, a gas filled in the fine pores, and phosphor particles. The gas filled in the micropores may be at least one selected from at least one of atmospheric air, oxygen, nitrogen, and an inert gas and a reduced pressure gas.

The dielectric layer may be composed of a sintered body of a dielectric. The dielectric layer may be composed of dielectric particles and a binder. The dielectric layer may be formed of a thin film. In addition, the porous light emitting layer may be formed of phosphor particles and an insulating layer on the surface of the phosphor particles. In addition, the porous light emitting layer may be made of phosphor particles and insulating fibers. The porous light emitting layer may be made of light emitting particles, an insulating layer on the surface of the phosphor particles, and insulating fibers.

By application of an electric field for polarization reversal to the pair of electrodes, primary electrons are emitted from the dielectric layer, and the emitted primary electrons are cyclically discharged in the porous light emitting layer to generate secondary electrons. It is preferable that a large amount of secondary electrons generated by discharge impinge on the phosphor particles and the porous light emitting layer emits light. The light emission may be performed in at least one gas atmosphere selected from the atmosphere, oxygen, nitrogen and inert gas atmospheres, and a reduced pressure gas. It is also preferable to apply an alternating electric field between another electrode and at least one of the pair of electrodes after applying an electric field in which polarization is reversed between the pair of electrodes.

The light emitting device of the present invention is a light emitting device including a porous light emitter, and is made of a porous light emitter including insulating phosphor particles, and is configured to charge-transfer by applying a predetermined electric field to the porous light emitter.

In addition, the light emitting device of the present invention is a light emitting device comprising an electron emitter, a porous light emitter and a pair of electrodes, wherein the porous light emitter comprises inorganic phosphor particles, and the porous light emitter is irradiated by electrons generated from the electron emitter. It is disposed adjacent to the electron emitter, and the pair of electrodes is configured so that an electric field is applied to at least part of the porous light emitter.

In this manner, the electrons are emitted by the electron emitters, and alternating electric fields are applied between the pair of electrodes, whereby the emitted electrons generate creeping discharges in the porous light emitting layer. As a result, the emitted light is excited by the emitted electrons to emit the porous light emitter. Also, a direct current electric field may be used instead of the alternating electric field described above.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described, referring drawings.

(Embodiment 1)

A description will be given with reference to FIGS. 1 to 6. In this example, a plurality of porous light emitting layers are formed in which a dielectric layer and a first electrode are formed on one side of the porous light emitting layer, respectively, and a second electrode is arranged on the other side of the porous light emitting layer, on which the first electrode is not formed. And discharging separation means between the plurality of porous light emitting layers. In particular, some of the porous light emitting layers are formed by sharing a dielectric layer, and the discharge separating means is a light emitting element formed of partition walls.

1 is a cross-sectional view of a light emitting element in the present embodiment, and FIGS. 2 to 6 are views for explaining a manufacturing process of the light emitting element in the present embodiment. In these figures, 1 is a light emitting element, 2 is a porous light emitting layer, 3 is a phosphor particle, 4 is an insulating layer, 5 is a substrate, 6 is a first electrode (back electrode), 7 is a second electrode (observation surface electrode), 8 is a translucent substrate, 9 is a gap (gas layer), 10 is a dielectric layer, and 11 is a partition wall.

As shown in FIG. 2, Ag paste is etched to a thickness of 30 μm on one surface of the sintered body of the dielectric 10 having a thickness of 0.3 to 1.0 mm, and the first electrode 6 is formed in a predetermined shape. Next, as shown in FIG. 3, the dielectric layer in which the electrode shown in FIG. 2 was formed was adhere | attached on the board | substrate 5 made of glass or ceramic.

Although BaTiO ₃ was used as the dielectric in this embodiment, the same effects can be obtained by using dielectrics such as SrTiO ₃ , CaTiO ₃ , MgTiO ₃ , PZT (PbZrTiO ₃ ), and PbTiO ₃ . In addition, the same effect can be obtained by using a dielectric such as Al ₂ O ₃ , MgO, ZrO ₂ , but the luminescence is weaker than that of the dielectric having a high relative dielectric constant. This can be improved by making the thickness of the dielectric layer thin.

In the dielectric layer, it is also possible to form the dielectric layer in a molecular deposition method such as sputtering, CVD, vapor deposition, or a thin film forming process such as sol / gel. When a sintered compact is used as the dielectric layer, it can be used as the substrate 5. The thickness of the dielectric layer changes extremely when a sintered body is used or when it is formed by a thick film process. In practice, however, the dose component is needed and adjusted in relation to the permittivity.

Next, as shown in FIG. 4, on the dielectric layer 10, several porous light emitting layers 2 are formed by screen printing in a predetermined shape.

As shown in FIG. 6, the porous light emitting layer 2 prepares the fluorescent substance particle 3 which coat | covered the surface with the insulating layer 4 which consists of metal oxides, such as MgO, in the following way.

As the phosphor particles 3, inorganic compounds such as BaMgAl ₁₀ O ₁₇ : Eu ²⁺ (blue), ZnSiO ₄ : Mn ²⁺ (green), YBO ₃ : Eu ³⁺ (red) having an average particle diameter of 2-3 μm It is possible to use. The method of forming the insulating layer 4 which consists of MgO on the surface is common to any fluorescent substance, Specifically, fluorescent substance 3 is added to Mg precursor complex solution, and it stirs for a long time. Then, the phosphor particles were extracted, dried, and then thermally treated at 400 to 600 ° C. in the air to form a coating layer having a uniform MgO, that is, an insulating layer 4 on the surface of the phosphor particles 3.

In the present embodiment, a paste obtained by kneading 45 mass% of terpineol (α-Terpineol) and 5 mass% of ethyl cellulose with respect to 50 mass% of the phosphor particles having the insulating layer 4 is prepared for each phosphor, Using this, as shown in FIG. 4, the screen printing to a predetermined shape and then drying were repeatedly performed many times, and it adjusted so that the thickness of the printed porous light emitting layer might be 80-100 micrometers.

In addition, as shown in Fig. 4, the light emission in the porous light emitting layer is a predetermined pattern (for example, a predetermined pattern (for example) in order to obtain light emission of red (R), green (G) and blue (B). For example, it is common to form a porous light emitting layer which is printed in a stripe shape and arranged regularly, and a desired light emitting color can be obtained by forming a light emitting layer from which white light emission is obtained, and then separating colors with a color filter. No problem

As described above, the substrate 5 on which the porous light emitting layer is printed is finally heat treated at 400 to 600 ° C. for 2 to 5 hours in an N ₂ atmosphere, thereby collecting the porous light emitting layer 2 having a thickness of about 50 to 80 μm. Formed.

In addition, although the said paste was performed by adding the organic binder and the organic solvent to fluorescent substance particle, the same effect can be acquired even if the paste which added the colloidal silica aqueous solution to fluorescent substance particle is used.

FIG. 6 is a schematic diagram in which the cross section of the porous light emitting layer 2 in the present embodiment is enlarged. As a result of the heat treatment of the phosphor particles 3 uniformly coated with the insulating layer 4 made of MgO, the respective particles are subjected to heat treatment. Shows a state in which the porous light emitting layers are formed in contact with each other.

In the present embodiment, since the heat treatment temperature is set relatively low, the porosity of the porous light emitting layer is increased, and the apparent porosity is in the range of 10% or more and less than 100%. If the porosity is so large that 100% of the pores are in a large state, the luminous efficiency is lowered or air discharge is generated inside the porous light emitting layer, which is not preferable. On the contrary, when the porosity is less than 10%, the generation of creeping discharges is inhibited (the creeping discharge occurs at the interface between the gas (pore in this case) and the insulator solid (phosphor particle). On the contrary, when the apparent porosity becomes larger than the average free stroke of electrons as described above, the surface discharge becomes less likely to occur, and the apparent porosity is less than 10% to less than 100%. It is assumed that the phosphor particles are close to the state of point contact such that they are three-dimensionally adjacent.

Next, in the aggregate composed of the porous light emitting layer 2, the operation of screen-printing and drying the glass paste at the boundary of the porous light emitting layer is repeated a plurality of times. After that, heat treatment at 600 DEG C is performed as shown in FIG. The partition 11 of 80-300 micrometers is formed. In the present embodiment, the partition wall 11 is formed after the porous light emitting layer is formed, but the partition wall may be formed first. In addition, the partition 11 can also be formed using glass paste or resin containing ceramic particles. Specifically, in the former, 50 mass% of α-terpineol is added to 50 mass% of mixed particles of ceramic and glass (1: 1 in weight ratio), and screen-kneading paste kneaded in a predetermined pattern is then repeated to dry. By adjusting the printed thickness to be about 100 to 350 µm and heat-treating at 400 to 600 ° C. for 2 to 5 hours in an N ₂ atmosphere, the partition 11 having a thickness of about 80 to 300 µm can be formed. Can be. In the latter, a partition is formed using a thermosetting resin, and epoxy resins, phenol resins, and cyanate resins can be used as the main ones, and one of them can be carried out by screen printing the pores of the porous light emitting layer.

As described above, the porous light emitting layer assembly is formed of a light transmissive substrate 8 such as a glass plate formed in advance so that the second electrode 7 made of ITO (indium-tin oxide alloy) is positioned to face the porous light emitting layer after forming the partition 11. When covering the whole, the light emitting element 1 in this embodiment as shown in FIG. 1 is obtained. At this time, the light-transmissive substrate 8 is attached onto the partition 11 using colloidal silica, water glass, resin, or the like so that a minute gap is formed between the porous light emitting layer 2 and the second electrode 7. The width in the vertical direction of the gap 9 between the porous light emitting layer 2 and the second electrode 7 is preferably in the range of 30 to 250 µm, particularly preferably in the range of 40 to 220 µm. When it exceeds the said range, it is necessary to apply a high voltage to generation | occurrence | production of the primary electron by the dielectric breakdown of gas, and it is unpreferable for the reason of economical efficiency and reliability. Although the interval is narrower than the above range, it is preferable that the interval is such that the porous light emitting layer does not come into contact with the second electrode in order to emit the porous light emitting layer uniformly and seamlessly.

In addition, it is also possible to use the translucent board | substrate with which copper wiring was given as a substitute of the translucent board | substrate 8 which consists of ITO as a 2nd electrode. The copper wiring is formed in a fine mesh shape, and the aperture ratio (ratio of the entire portion where no wiring has been performed) is 90%, and the transmission of light is almost inferior to that of a translucent substrate having an ITO film. In addition, copper is suitable because it is very low in resistance compared with ITO because it greatly contributes to the improvement of luminous efficiency. In addition to the copper, gold, silver, platinum, and aluminum can be used as the metal for fine wiring. In the case of copper and aluminum, however, oxidation may occur, and therefore oxidation treatment is required.

As described above, in this embodiment, a dielectric layer and a first electrode are formed on one surface of the porous light emitting layer, respectively, and a second electrode is disposed on the other surface of the dielectric layer and the first electrode of the porous light emitting layer. A light emitting device comprising a plurality of porous light emitting layers and comprising a discharge separating means between the plurality of porous light emitting layers, and particularly, partition walls are formed as discharge separating means between the plurality of porous light emitting layers, and some of the plurality of porous light emitting layers are formed. A light emitting device can be fabricated in which the dielectric layer is formed in some of the plurality of porous light emitting layers so that the porous light emitting layers of the same share a dielectric layer.

In the present embodiment, the surface of the phosphor particles 3 is covered with an insulating layer 4 made of MgO. Thereby, MgO has a high resistivity (10 ⁹ ohm * cm or more) and can generate creeping discharge efficiently. If the resistivity of the insulating layer is low, creeping discharges are less likely to occur and are sometimes shorted, which is not preferable. For this reason, it is preferable to coat | cover with insulating metal oxide with high resistivity. Of course, when the resistivity of the phosphor particles to be used is high, creeping discharge is easily generated even without coating with an insulating metal oxide. As the insulating layer, at least one selected from Y ₂ O ₃ , Li ₂ O, CaO, BaO, SrO, A1 ₂ O ₃ , SiO ₂ , and ZrO ₂ can be used as the insulating layer. The standard production free energy ΔG _f0 of these oxides is very small (eg below -100 kcal / mo1 at room temperature) and is a stable material. Moreover, since these insulating layers have high resistivity and are easy to generate discharge and are difficult to reduce, they are also excellent as a protective film for suppressing reduction of phosphor particles and further ultraviolet degradation in discharge, and as a result, durability of the phosphor is high and suitable.

The insulating layer can be formed by a chemical adsorption method, a CVD method, a sputtering method, a vapor deposition method, a laser method, a shear stress method, or the like in addition to the sol-gel method described above. It is preferable that the insulating layer is homogeneous and uniform and not peeled off. When forming the insulating layer, it is important to immerse the particles of the phosphor in a weak acid solution such as acetic acid, oxalic acid, citric acid, and to clean impurities adhering to the surface.

In addition, it is preferable that the particles of the phosphor are pretreated for about 1 to 5 hours at 200 to 500 ° C. in a nitrogen atmosphere before the insulating layer is formed. This is because ordinary phosphor particles contain a large amount of adsorbed water or crystal water, and forming an insulating layer in such a state undesirably affects lifetime characteristics such as lowering of luminance and shift of emission spectrum. When the particle | grains of fluorescent substance are wash | cleaned with a weakly acidic solution, after wash | cleaning well, said pretreatment is performed.

In the heat treatment step of forming the porous light emitting layer, attention is given to the heat treatment temperature and the atmosphere. In the present embodiment, heat treatment was performed at a temperature range of 450 to 1200 ° C. in a nitrogen atmosphere, so that the valence of the rare earth atoms doped in the phosphor was not changed. However, when treating at a temperature higher than this temperature range, care should be taken because the valence of the rare earth atoms may change or a solid solution composed of the insulating layer and the phosphor may occur.

In addition, attention must be paid to the increase in the heat treatment temperature as well as the apparent porosity of the porous light emitting layer. Judging from these, the optimum heat treatment temperature is preferably in the range of 450 to 1200 ° C. As for the heat treatment atmosphere, a nitrogen atmosphere is preferable in order not to affect the valence of the rare earth atoms doped in the phosphor particles as described above.

Although the thickness of the insulating layer was about 0.1-2.0 micrometers in this embodiment, it determines in consideration of generating the average particle diameter of a fluorescent substance particle | grain, and surface discharge efficiently. If the average particle diameter of the phosphor is in a sub-micron order, it is better to coat relatively thinly. When the insulating layer becomes thick, shift of the emission spectrum, deterioration in luminance, etc. occur, which is not preferable. On the contrary, when the insulating layer becomes thin, it is assumed that creeping discharge is less likely to occur. Therefore, the relationship between the average particle diameter of the phosphor particles and the thickness of the insulating layer is preferably in the range of 1/10 to 1/500 for the former 1.

Next, the light emitting action of the light emitting element 1 will be described with reference to FIGS. 1 and 17.

As shown in FIG. 1, in order to drive the light emitting element 1, an alternating electric field is applied between the first electrode 6 and the second electrode 7. The dielectric layer 10, the porous light emitting layer 2, and the gap (gas layer) 9 are present in series in the thickness direction between the electrodes 6 and 7. The applied electric field is thus concentrated in the gap 9 in proportion to the reciprocal of each capacitance. Therefore, dielectric breakdown of the gas occurs in the gap 9, and the primary electrons (e-) 24 shown in FIG. 17 are generated. The primary electrons (e-) collide with the phosphor particles (3) and the insulating layer (4) of the porous light emitting layer (2), resulting in creeping discharge, and further, a large number of secondary electrons (e-) 25 are generated. As a result, the generated electrons or ultraviolet rays collide with the emission center of the phosphor, and the phosphor particles 3 are excited to emit light. In addition, the inversion of the polarization is repeated in the dielectric layer by application of an alternating electric field. As a result, electrons are generated and charge is injected into the porous light emitting layer, whereby creeping discharge occurs. Creeping discharge is continuously generated while an electric field is applied, and at this time, the generated electrons or ultraviolet rays collide with the emission center of the phosphor, and the phosphor particles 3 are excited to emit light.

In addition, by changing the waveform of the alternating electric field to be applied from a sine wave or a sawtooth wave to a rectangular wave and raising the frequency from several hundred Hz to several thousand Hz, the emission of primary electrons, secondary electrons, and ultraviolet rays is extremely intense, resulting in improved luminance. do. In addition, a burst wave is generated as the voltage of the alternating electric field increases. The generation frequency of the burst wave is generated just before the peak in the sine wave and at the peak in the sawtooth wave or the rectangular wave, and the emission luminance is improved by raising the voltage of the burst wave. Once the creeping discharge is started, ultraviolet rays and visible light are also generated, so it is necessary to suppress deterioration of the phosphor particles 3 due to these light rays, and it is preferable to reduce the voltage after the start of light emission.

In the present embodiment, the phosphor particles 3 are emitted by applying an electric field (frequency: 1 kHz) of about 0.72 to 1.5 kV / mm in the thickness direction of the porous light emitting layer, and then alternately about 0.5 to 1.0 kV / mm. By applying an electric field (frequency: 1 kHz), creeping discharge was continued, and light emission of the fluorescent substance particles 3 was continued. If the applied electric field is large, the generation of electrons or ultraviolet rays is accelerated, but if the electric field is small, these generations are insufficient.

In addition, the current value at the time of discharge is 0.1 mA or less, and when light emission starts, light emission continues even if it reduces about 50 to 80% at the time of voltage application, and high luminance, high contrast, high recognition, It was confirmed that it was high reliability light emission.

In this embodiment, although driving was performed in air | atmosphere, it confirmed that light emission was carried out similarly even if it carried out in oxygen, nitrogen, an inert gas, or gas under reduced pressure.

According to the light emitting device of the present embodiment, since the light emission is caused by the surface discharge in the porous light emitting layer, the structure does not require a thin film forming process and does not require a vacuum system or a carrier multiplication layer in the production of the light emitting device as in the prior art. Simple and easy to manufacture and process. In addition, it is possible to provide a light emitting element having good luminous efficiency and relatively small power consumption when a large display is used. In this embodiment, a partition wall is provided as a discharge separating means at the boundary of the porous light emitting layer, so that crosstalk during light emission can be avoided by a relatively simple method.

(Embodiment 2)

It demonstrates, referring FIG. In this example, a dielectric layer and a first electrode are formed on one surface of the porous light emitting layer, respectively, and a plurality of the porous light emitting layers in which the second electrode is disposed on the other surface where the dielectric layer and the first electrode of the porous light emitting layer are not formed. A light emitting element comprising an aggregate, comprising a discharge separating means between the plurality of porous light emitting layers, and wherein the discharge separating means is a partition wall. 7 is a cross-sectional view of a light emitting device according to the present embodiment, in which 1 is a light emitting device, 2 is a porous light emitting layer, 3 is a phosphor particle, 4 is an insulating layer, 5 is a substrate, and 6 is a first electrode (back electrode). 7 is a second electrode (observation surface side electrode), 8 is a translucent substrate, 9 is a gap (gas layer), 10 is a dielectric layer and 11 is a partition wall.

In the first embodiment, as shown in FIG. 1, the dielectric layer 10 and the first electrode 6 formed under the porous light emitting layer are shared by a plurality of porous light emitting layers. It is also possible to form each of the plurality of porous light emitting layers individually. The light emitting element of this embodiment is comprised in this way, and the structure of the cross section is shown in FIG.

The light emitting element in the present embodiment can be produced by the same production method as in the first embodiment. In fact, in accordance with the portion where the porous light emitting layer is formed and arranged in a predetermined pattern shape, first, the Ag paste is etched to form the first electrode 6, and a dielectric layer is formed thereon by a thick film process or the like, and then the porous light emitting layer is screened. What is necessary is just to form by printing. After this, if the partitions are formed in the same manner as in the first embodiment, and finally the translucent substrate 8 having the second electrode is disposed, the light emitting element of the present embodiment shown in FIG. 7 can be manufactured.

Next, the light emission effect of this light emitting element 1 is demonstrated with reference to FIG. As shown in FIG. 7, in order to drive the light emitting element 1, an alternating electric field is applied between the first electrode 6 and the second electrode 7. The application of an alternating electric field causes insulation breakdown of the gas in the gap 9, and electrons are generated accordingly, and charge is injected into the porous light emitting layer, resulting in creeping discharge. Creeping discharges continue to occur while an electric field is applied, and at this time, the generated electrons or ultraviolet rays collide with the emission center of the phosphor, and the phosphor particles 3 are excited to emit light.

In addition, by changing the waveform of the alternating current electric field to be applied from a sine wave or a sawtooth wave to a rectangular wave and raising the frequency from several hundred Hz to several thousand Hz, the emission of electrons and ultraviolet rays due to creeping discharge is extremely intense, and the luminescence brightness is improved. In addition, burst waves are generated as the voltage of the AC field is raised. The generation frequency of the burst wave occurred immediately before the peak in the sine wave and at the peak in the sawtooth wave or the rectangular wave, and the emission luminance was improved at the same time as the burst wave voltage was increased. Once the creeping discharge is started, ultraviolet rays and visible light are also generated, so it is necessary to suppress deterioration of the phosphor particles 3 due to these light rays, and it is preferable to reduce the voltage after the start of light emission.

In the present embodiment, the surface of the porous light emitting layer is applied with an electric field of about 0.72 to 1.5 kV mm to emit the phosphor particles 3, and then an alternating electric field of about 0.5 to 1.0 kV / mm is applied to the creepage surface. Discharge was continued, and light emission of the fluorescent substance particle 3 was continued. If the electric field to be applied is large, the generation of electrons or ultraviolet rays is promoted, but if it is small, these generations are insufficient.

In addition, the current value at the time of discharge is 0.1 mA or less, and when light emission starts, light emission will continue even if voltage is reduced about 50 to 80% at the time of application, and high luminance, high contrast, and high recognizability in all three colors of light emission , It was confirmed that the light emission was high reliability.

In the present embodiment, the driving was performed in the air, but it was confirmed that the light emission was similarly performed even in the oxygen, nitrogen, and inert gas or under reduced pressure.

According to the light emitting device of the present embodiment, since the light emission is caused by the surface discharge in the porous light emitting layer, the structure does not require a thin film forming process and does not require a vacuum system or a carrier multiplication layer in the production of the light emitting device as in the prior art. Simple and easy to manufacture and process. In addition, it is possible to provide a light emitting element having good luminous efficiency and relatively low power consumption in a large display. In this embodiment, the partition wall is provided as a discharge separating means at the boundary of the porous light emitting layer, so that colossal torque during light emission can be avoided by a relatively simple method.

(Embodiment 3)

Referring to FIG. 8, a plurality of the porous layers having a dielectric layer and a first electrode formed on one surface of the porous light emitting layer, respectively, and a second electrode disposed on the other surface where the dielectric layer and the first electrode of the porous light emitting layer are not formed. The light emitting element which consists of an aggregate of a light emitting layer, is provided with discharge separation means between the said several porous light emitting layers, and a discharge separation means is a partition with electroconductivity is demonstrated.

Fig. 8 is a cross-sectional view of the light emitting element according to the present embodiment, in which 1 is a light emitting element, 2 is a porous light emitting layer, 3 is a phosphor particle, 4 is an insulating layer, 5 is a substrate, and 6 is a first electrode (back electrode). ), 7 is a second electrode (observation surface side electrode), 8 is a translucent substrate, 9 is a gap (gas layer), 10 is a dielectric layer and 11 is a partition wall.

As described above, in the present embodiment, as the discharge separating means, the conductive partition wall 11 effective for the electrostatic shielding and the extension of the creepage discharge is used. Such conductive partitions can be formed by deposits or deposits of various metals. As an example, the method to form using electroless nickel plating is demonstrated.

The manufacturing method of a specific light emitting element is performed as follows. First, a resist film is formed by screen printing on a portion other than the portion that forms the partition wall on the surface of the ceramic substrate 5. After this, the substrate 5 is immersed in a solution consisting of tin chloride and palladium chloride. Such a treatment is called a catering / sensitizing treatment, and can be easily performed with a commercially available treatment agent including a post-treatment treatment.

When the resist film is peeled off after the treatment, fine particles of palladium adhere to only the portion forming the partition wall. The ceramic substrate 5 thus treated is immersed in a solution (pH 4 to 6) containing nickel sulfate and sodium hypophosphite as a main component, and the metal nickel is deposited to a thickness of 80 to 300 mu m at a temperature of about 90 deg. The partition 11 of a predetermined shape can be formed on the surface of the substrate 5. As described above, the ceramic substrate 5 having the conductive partition wall 11 formed thereon can be obtained.

After this, the Ag electrode is etched on the substrate 5 to form the first electrode 6. At this time, the first electrode 6 is formed with a small gap so as not to contact the conductive partition 11. After the first electrode 6 is formed, the dielectric layer 10 is formed on the first electrode 6 by a thick film process or the like. Subsequently, the paste containing the phosphor particles 3 whose surface is uniformly covered with the insulating layer 4 is screen printed and baked to form the porous light emitting layer 2 in a predetermined pattern shape. Finally, when the whole porous light emitting layer assembly is covered with the glass transparent substrate 8 having the ITO film as the second electrode 7 on the surface, the light emitting element 1 as shown in FIG. 8 can be obtained. At this time, a fine gap is formed so that the second electrode made of ITO does not come into contact with the conductive partition wall, and the application of voltage is not prevented in driving the light emitting element.

As described above, in the present embodiment, a dielectric layer and a first electrode are formed on one surface of the porous light emitting layer, respectively, and a second electrode is disposed on the other surface of the dielectric layer and the first electrode of the porous light emitting layer. The light emitting device is composed of a plurality of porous light emitting layers, and is provided with a discharge separating means between the plurality of porous light emitting layers, and the discharge separating means is a partition having conductive conductivity.

Next, the light emission effect of this light emitting element 1 is demonstrated with reference to FIG. In order to drive the light emitting element 1 of FIG. 8, an alternating electric field is applied between the first electrode 6 and the second electrode 7. Insulation breakdown of the gas occurs in the gap 9 by the application of an alternating current, electrons are generated accordingly, and charge is injected into the porous light emitting layer, resulting in creeping discharge. Creeping discharges continue to occur while an electric field is applied, and at this time, the generated electrons or ultraviolet rays collide with the emission center of the phosphor, and the phosphor particles 3 are excited to emit light.

In addition, by changing the waveform of the alternating current electric field to be applied from a sine wave or a sawtooth wave to a rectangular wave and raising the frequency from several hundred Hz to several thousand Hz, the emission of electrons or ultraviolet rays due to creeping discharge is extremely intense, and the luminescence brightness is improved. In addition, a burst wave is generated by raising the voltage value of the AC electric field. The generation frequency of the burst wave is generated just before the peak in the sine wave and at the peak in the sawtooth wave or the rectangular wave, and the emission luminance is improved by raising the voltage of the burst wave. Once the creeping discharge is started, ultraviolet rays and visible light are also generated, so it is necessary to suppress deterioration of the phosphor particles 3 due to these light rays, and it is preferable to reduce the voltage after the start of light emission.

In particular, when conductive partitions are formed as in the present embodiment, creeping discharges are likely to occur, which can contribute to a reduction in driving voltage. That is, the fluorescent material particles 3 are lighted by applying an electric field of about 0.58 to 1.2 kV / mm to the thickness of the porous light emitting layer, and then creeping discharge is continued by applying an alternating electric field of about 0.4 to 0.8 kV / mm. Light emission of the phosphor particles 3 was continued. If the electric field to be applied is large, the generation of electrons or ultraviolet rays is promoted, but if it is small, these generations are insufficient.

In addition, the current value at the time of discharge is 0.1 mA or less, and when light emission starts, light emission continues even if it reduces about 50 to 80% at the time of voltage application, and high luminance, high contrast, high recognition, It was confirmed that it was high reliability light emission.

According to the light emitting device of the present embodiment, since the light emission is caused by the surface discharge in the porous light emitting layer, the structure does not require a thin film forming process and does not require a vacuum system or a carrier multiplication layer in the production of the light emitting device as in the prior art. Simple and easy to manufacture and process. In addition, it is possible to provide a light emitting element having good luminous efficiency and relatively small power consumption when a large display is used. In this embodiment, a partition wall is provided as a discharge separating means at the boundary of the porous light emitting layer, so that crosstalk during light emission can be avoided by a relatively simple method.

(Embodiment 4)

9 to 13, a dielectric layer and a first electrode are formed on one surface of the porous light emitting layer, respectively, and a plurality of second electrodes are disposed on the other surface where the dielectric layer and the first electrode of the porous light emitting layer are not formed. With respect to a light emitting element comprising an assembly of two porous light emitting layers, comprising a discharge separating means between the plurality of porous light emitting layers, in particular, a plurality of porous light emitting layers are arranged so as to share a second electrode, and the discharge separating means is spaced. A phosphorescent light emitting element is demonstrated.

9 is a cross-sectional view of a light emitting element in the present embodiment, and FIGS. 10 to 13 are views for explaining a manufacturing step of the light emitting element in the present embodiment. In these figures, 1 is a light emitting element, 2 is a porous light emitting layer, 3 is phosphor particles, 4 is an insulating layer, 5 is a substrate, 6 is a first electrode (back electrode), 7 is a second electrode (observation electrode), 8 9 is a light-transmissive substrate, 9 is a gap (gas layer), 10 is a dielectric layer, 12 is a gap separating the porous light emitting layer, and 15 is a side wall. As shown in FIG. 10, Ag paste is etched on one surface of the glass or ceramic substrate 5, and the 1st electrode 6 is formed in predetermined shape. Next, as shown in FIG. 11, the dielectric layer 10 is formed on the first electrode 6 by a thick film process or the like.

Next, the porous light emitting layer 2 is formed on the dielectric layer 10 in a predetermined shape. At this time, the fluorescent substance particle 3 which covered the surface with the insulating layer 4 which consists of metal oxides, such as MgO, was used similarly to Embodiment 1. Such as Eu ³⁺ (red): the phosphor particles (3), an average particle diameter of ^{_{2~3㎛ BaMgAl 10 O 17: Eu 2}} + ( blue), Zn ₂ SiO _4: Mn ²⁺ (green), YBO ₃ It is possible to use an inorganic compound.

In the present embodiment, a paste obtained by kneading 45 mass% of α-terpineol and 5 mass% of ethyl cellulose with respect to 50 mass% of the phosphor particles having the insulating layer 4 is prepared for each phosphor, and the dielectric layer is prepared. The operation of screen printing on (10) and then drying was repeated a plurality of times to adjust the thickness of the printed portion to be 80 to 100 µm.

As described above, the substrate 5 on which the porous light emitting layer is printed is heat-treated at 400 to 600 ° C. for 2 to 5 hours in an N ₂ atmosphere, so that it is about 50 to 80 μm on the substrate as shown in FIG. 12. The aggregate of the porous light emitting layer 2 of thickness was formed.

Next, this embodiment makes the voids 12 at about 80 to 300 µm without leaving a partition at the boundary of the aggregate composed of the porous light emitting layer 2, and functions these voids as a substitute for the partition walls. There is a characteristic of. In the present embodiment, the side wall 15 is formed so as to surround the entire aggregate made of the porous light-emitting layer 2, and thus the translucent substrate 8 is described later as the side wall surrounding the periphery of the aggregate. Support. Formation of the side wall 15 is performed by screen-printing and drying a glass paste many times, and baking it at 600 degreeC after this, and forming the side wall 15 of about 80-300 micrometers as shown in FIG. do.

In addition, the side wall 15 can also be formed using glass paste or resin containing ceramic particles. Specifically, in the former, 50 mass% of α-terpineol was added to 50 mass% of mixed particles of ceramic and glass (1: 1 by weight), followed by screen printing of the kneaded paste, followed by drying. by adjusting the thickness to be about 100~350㎛, and heat treatment in a N ₂ atmosphere over, in 2-5 hours at 400~600 ℃, it is possible to form the side wall 15 in the thickness of about 80~300㎛. In the latter case, the partition wall is formed using a thermosetting resin, and epoxy resins, phenol resins, and cyanate resins can be used as the main ones, and one of them can be selected and printed to surround the entire porous light emitting layer assembly. .

After the side wall 15 is formed as described above, a light transmissive substrate 8 such as a glass plate on which the second electrode 7 made of ITO (indium-tin oxide alloy) is formed is attached to the side wall 15 to form a porous light emitting layer. If the whole of an aggregate is covered, the light emitting element 1 in this embodiment shown in FIG. 9 can be obtained. At this time, as shown in the drawing, the second electrode 7 is formed to face the porous light emitting layer in a stripe shape, for example, and is shared by a plurality of porous light emitting layers. In addition, a minute gap is formed between the porous light emitting layer 2 and the second electrode 7, and the interval between the two is preferably in the range of 30 to 250 µm, particularly preferably in the range of 40 to 220 µm.

In addition, it is also possible to use the board | substrate with which the fine wiring of the mesh shape which consists of copper, gold, silver, platinum, aluminum, etc. was used as a substitute of the translucent board | substrate 8 which consists of ITO as a 2nd electrode.

As described above, a plurality of the porous light emitting layers each having a dielectric layer and a first electrode formed on one surface of the porous light emitting layer, and a second electrode disposed on the other surface where the dielectric layer and the first electrode of the porous light emitting layer are not formed. A light emitting device comprising an aggregate of a plurality of porous light emitting layers, the light emitting device comprising discharge separation means, in particular arranged so that the second electrode is shared by the plurality of porous light emitting layers, and the discharge separation means having a void. Can be.

Next, the light emission effect of this light emitting element 1 is demonstrated with reference to FIG. As shown in FIG. 9, in order to drive the light emitting element 1, an alternating electric field is applied between the first electrode 6 and the second electrode 7. The application of an alternating electric field causes dielectric breakdown of the gas in the gap 9, thereby generating electrons and injecting charge into the porous light emitting layer, resulting in creeping discharge. Creeping discharges continue to occur while an electric field is applied, and at this time, the generated electrons or ultraviolet rays collide with the emission center of the phosphor, and the phosphor particles 3 are excited to emit light.

Furthermore, by changing the waveform of the alternating current electric field to be applied from a sine wave or a sawtooth wave to a rectangular wave, and raising the frequency from several hundred Hz to several thousand Hz, the emission of electrons or ultraviolet rays due to creeping discharge is extremely intense, and the luminescence brightness is improved. In addition, a burst wave is generated as the voltage value of the AC electric field is raised. The generation frequency of the burst wave is generated just before the peak in the sine wave and at the peak in the sawtooth wave or the rectangular wave, and the emission luminance is improved by raising the voltage of the burst wave. Once the creeping discharge is started, ultraviolet rays and visible rays are also generated, so it is necessary to suppress deterioration of the phosphor particles 3 due to these rays, and it is preferable to reduce the voltage after the start of light emission.

In the present embodiment, the phosphor particles 3 are emitted by applying an electric field of about 0.85 to 1.8 kV / mm to the thickness of the porous light emitting layer, and then by applying an alternating electric field of about 0.6 to 1.2 kV / mm, Creeping discharge was continued, and light emission of the fluorescent substance particle 3 was continued. If the electric field to be applied is large, the generation of electrons or ultraviolet rays is promoted, but if it is small, these generations are insufficient.

In addition, the current value at the time of discharge is 0.1 mA or less, and when light emission starts, light emission will continue even if voltage is reduced about 50 to 80% at the time of application, and high luminance, high contrast, and high recognizability in all three colors of light emission , It was confirmed that the light emission was high reliability.

Although driving was performed in air | atmosphere in this embodiment, it confirmed that light emission was carried out similarly even if it carried out in oxygen, nitrogen, an inert gas, or gas under reduced pressure.

According to the light emitting device of the present embodiment, since the light emission is caused by the surface discharge in the porous light emitting layer, the structure does not require a thin film forming process and does not require a vacuum system or a carrier multiplication layer in the production of the light emitting device as in the prior art. Simple and easy to manufacture and process. In addition, it is possible to provide a light emitting element having good luminous efficiency and relatively small power consumption when a large display is used. In this embodiment, by providing a space at the boundary of the porous light emitting layer as discharge separation means, crosstalk during light emission can be avoided by a relatively simple method.

(Embodiment 5)

14 and 15, a dielectric layer and a first electrode are formed on one surface of the porous light emitting layer, respectively, and a second electrode is disposed on the other surface of the dielectric layer and the first electrode of the porous light emitting layer. A light emitting element composed of a plurality of porous light emitting layers and provided with a discharge separating means between the plurality of porous light emitting layers, particularly a porous light emitting layer.

14 and 15 are schematic diagrams in which a cross section of the porous light emitting layer in the present embodiment is enlarged. In these figures, 2 is a porous light emitting layer, 3 is a phosphor particle, 4 is an insulating layer, and 18 is an insulating fiber.

In this embodiment, the porous light emitting layer 2 which consists of fluorescent substance particle | grains and insulating fibers 18, such as ceramic and glass, was formed regardless of the presence or absence of the insulating layer on the surface of fluorescent substance particles.

As an example of insulating fibers _{(18), SiO 2 -Al 2} O 3 -CaO using the fibers of the system, and its diameter is 0.1~5㎛, length, and that the size of the range of preferably 0.5~20㎛ fiber Is used in a proportion of 2 parts by weight of phosphor particles and 1 part by weight of fiber, and the porosity is relatively large. As a result, creeping discharge is easily generated inside the porous light emitting layer. In this embodiment, when forming a porous light emitting layer, the paste which knead | mixed 45 mass% of (alpha)-terpineol and 5 mass% of ethyl cellulose with respect to 50 mass% of mixtures of fluorescent substance particle | grains and insulating fiber is prepared, In the same manner as in Embodiment 1, the paste was screen printed in a pattern to form a porous light emitting layer. 14 and 15 show schematic enlarged views of the cross section of the porous light emitting layer containing the insulating fiber 18 thus obtained. FIG. 15 is a porous light emitting layer 2 made of phosphor particles 3 and insulating fibers 18, and FIG. 14 is a porous light emitting layer made of phosphor particles 3 and insulating fibers whose surface is covered with an insulating layer 4. In addition, the formation of the first electrode, the dielectric layer, the second electrode and the partition wall was carried out in the same manner as in the first embodiment, whereby a light emitting device similar to the first embodiment was finally produced (not shown).

The reason why the fiber of the SiO ₂ -Al ₂ O ₃ -CaO system was selected as the insulating fiber is that it is thermally and chemically stable and has a resistivity of 10 ⁹ Ω · cm or more and a large appearance of 10% or more and less than 100% in the porous light emitting layer. This is because the porosity can be easily obtained, and discharge easily occurs on the surface of the fiber, and as a result, creeping discharge can be generated in the entire porous light emitting layer. In addition to the above insulating fibers, almost the same results can be obtained by using insulating fibers containing SiC, ZnO, TiO ₂ , MgO, BN, Si ₃ N ₄ systems.

Next, the light emitting action of this light emitting element is the same as that of the first embodiment. In order to drive the light emitting element, an alternating electric field is applied between the first electrode and the second electrode. Insulation breakdown of the gas occurs in the gap 9 by the application of an alternating current electric field, electrons are generated accordingly, and electric charge is injected into the porous light emitting layer, resulting in creeping discharge. Creeping discharges continue to occur while an electric field is applied, and at this time, the generated electrons or ultraviolet rays collide with the emission center of the phosphor, and the phosphor particles 3 are excited to emit light.

In the present embodiment, the phosphor particles 3 are emitted by applying an electric field of about 0.65 to 1.4 kV / mm to the thickness of the porous light emitting layer, and then by applying an alternating electric field of about 0.45 to 0.90 kV / mm, Creeping discharge was continued, and light emission of the fluorescent substance particle 3 was continued. If the electric field to be applied is large, the generation of electrons or ultraviolet rays is promoted, but if it is small, these generations are insufficient.

In addition, the current value at the time of discharge is 0.1 mA or less, and when light emission starts, light emission continues even if it reduces about 50 to 80% at the time of voltage application, and high luminance, high contrast, high recognition, It was confirmed that it was high reliability light emission.

Although driving was performed in air | atmosphere in this embodiment, it confirmed that light emission was carried out similarly even if it carried out in oxygen, nitrogen, an inert gas, or gas under reduced pressure.

According to the light emitting element of this embodiment, since it is light emission by the surface discharge in a porous light emitting layer, it does not use a thin film formation process and does not require a vacuum system or a carrier multiplication layer in manufacture of a light emitting element like a conventional structure. Is simple, and manufacture and processing are also easy. In addition, it is possible to provide a light emitting element having good luminous efficiency and relatively small power consumption when a large display is used. In this embodiment, a partition wall is provided as a discharge separating means at the boundary of the porous light emitting layer, so that crosstalk during light emission can be avoided by a relatively simple method.

(Embodiment 6)

Referring to FIG. 16, a plurality of porous light emitting layers in which a dielectric layer and an address electrode are formed on one surface of the porous light emitting layer, respectively, and a data electrode is disposed on the other surface where the dielectric layer and the address electrode of the porous light emitting layer are not formed. The operation of the light emitting device comprising a discharge separation means between the plurality of porous light emitting layers is described.

Fig. 16 is an exploded perspective view of the light emitting element according to the present embodiment and shows a light emitting element in the case where the discharge separating means is a void for clarity. In the drawings, 1 is a light emitting element, 2 is a porous light emitting layer, 5 is a substrate, 8 is a light transmissive substrate, 10 is a dielectric layer, 12 is a void, 21 is an address electrode, and 22 is a display electrode.

As shown in Fig. 16, in the light emitting element 1 of the present embodiment, an address electrode 21 is formed on a substrate 5, and a plurality of porous light emitting layers 2 having a dielectric layer 10 thereon are formed. Arranged regularly, the alignment of the porous light emitting layer which emits three colors of R, G, and B is formed. Sidewalls are usually formed (not shown) so that voids 12 exist between the porous light emitting layers and surround the entire alignment of the porous light emitting layer 2. In the light transmissive substrate 8, the display electrode 22 is formed to face the porous light emitting layer 2 so as to intersect the address electrode 21, and finally, the light transmissive substrate 8 is disposed on the alignment of the porous light emitting layer. The light emitting element 1 as shown in FIG. 16 is comprised. The address electrode and the display electrode in the present embodiment may be respectively corresponded to the first electrode and the second electrode in the above-described Embodiments 1 to 5, but may be provided separately in some cases.

As described above, a dielectric layer and an address electrode are respectively formed on one surface of the porous light emitting layer, and the dielectric layer and a plurality of the porous light emitting layers are arranged on the other surface where the address electrode is not formed. The light emitting element which provided the discharge separation means between the said several porous light emitting layers, and especially the light emitting element whose discharge separation means is a space | gap was obtained.

In the light emitting element 1 according to the present embodiment configured as described above, a two-dimensional image can be displayed on the porous light emitting layer. That is, in the light emitting element 1 of the present embodiment, so-called simple matrix driving is possible, pulse signals are sequentially transferred to the X electrode, and ON / OFF information is put into the Y electrode in accordance with the timing so that the address electrode and the display electrode cross each other. One line is displayed by making the pixel of the part to emit light according to ON / OFF. By sequentially changing the scanning pulses, a two-dimensional image can be displayed. In addition, active driving is also possible by providing transistors in one pixel of a matrix arranged and turning ON / OFF each pixel. In the present embodiment, since the voids 12 are formed in the porous light emitting layer, there is little crosstalk of light emission. However, as described above in Embodiment 1, when partition walls are formed between unit light emitting elements, crosstalk of light emission is achieved. Can be almost completely avoided.

(Embodiment 7)

18 is a cross section of the display device of the present embodiment. This embodiment was the same as that of Embodiment 1 shown in FIG. 1 except that the ribs 23a and 23b were provided between the partitions 11. Horizontal thickness of partition wall 11: 150 μm, height 270 μm, thickness of ribs 23a, 23b: 50 μm, height 250 μm, width of one pixel is 100 μm, thickness of porous light emitting layer is 230 μm, gap (base layer) gap 9 is 20㎛, thickness of the dielectric layer 10 made of BaTiO ₃ had a distance of 500㎛ 250㎛, the first electrode 6 and the second electrode (7).

In this embodiment, the phosphor particles 3 are made to emit light by applying an electric field (frequency: 1 kHz) of about 0.72 to 1.5 kV / mm in the thickness direction of the porous light emitting layer, and thereafter an alternating electric field of about 0.4 kV / mm ( By applying a frequency of 1 kHz), surface discharge was continued, and light emission of the phosphor particles 3 was continued. If the applied electric field is large, the generation of electrons or ultraviolet rays is promoted, but if the electric field is small, these generations are insufficient.

In addition, the current value at the time of discharge is 0.1 mA or less, and when light emission starts, light emission continues even if it reduces about 50 to 80% at the time of voltage application, and high luminance, high contrast, high recognition, It was confirmed that it was high reliability light emission.

In this embodiment, although driving was performed in air | atmosphere, it confirmed that light emission was carried out similarly even if it carried out in oxygen, nitrogen, an inert gas, or gas under reduced pressure.

(Embodiment 8)

19 is a cross section of the display device of the present embodiment. This embodiment was the same as that of Embodiment 1 shown in FIG. 1 except that the partition 11 was formed by cutting the dielectric layer 10 made of BaTiO ₃ . Horizontal thickness of partition 11: 150 μm, height 270 μm, width of one pixel is 250 μm, thickness of porous light emitting layer is 230 μm, gap 9 is 20 μm, and thickness of dielectric layer consists of BaTiO ₃ 520 micrometers and the 1st and 2nd electrode distance were 500 micrometers.

In the present embodiment, the phosphor particles 3 are emitted by applying an electric field (frequency: 1 kHz) of about 0.72 to 1.5 kV / mm in the thickness direction of the porous light emitting layer, after which an alternating electric field of about 0.4 kV / mm ( By applying a frequency of 1 kHz), surface discharge was continued, and light emission of the phosphor particles 3 was continued. If the electric field to be applied is large, the generation of electrons or ultraviolet rays is promoted, but if it is small, these generations are insufficient.

In addition, the current value at the time of discharge is 0.1 mA or less, and when light emission starts, light emission continues even if it reduces about 50 to 80% at the time of voltage application, and high luminance, high contrast, high recognition, It was confirmed that it was high reliability light emission.

In this embodiment, although driving was performed in air | atmosphere, it confirmed that light emission was carried out similarly even if it carried out in oxygen, nitrogen, an inert gas, or gas under reduced pressure.

(Comparative Example 1)

As a comparative example 1, the silicon oil impregnation used for the dielectric breakdown test of a laminated chip capacitor was implemented. In other words, when the dielectric breakdown voltage is measured in the multilayer chip capacitor, creepage discharge occurs frequently and thus the actual dielectric breakdown voltage cannot be measured. Thus, the actual breakdown voltage value was obtained in the state where the creeping discharge was not caused by impregnating silicon oil into the minute hole of the device. Using this method, the gas in the micropores of the porous light emitting layer 2 of the light emitting element 1 in Fig. 1 was replaced with silicone oil. After immersion for several minutes, the silicone oil on the surface of the light emitting element was wiped off, and an alternating electric field similar to that of the first embodiment was applied.

First, it was confirmed that when the applied voltage was raised, a burst wave was generated and primary electrons were emitted from the gap. However, in the porous light emitting layer 2, no creeping discharge was generated at all, or even when the creeping discharge occurred, the light emission could not be confirmed because it was generated in the polar surface portion instead of the inside of the light emitting layer 2. In addition, if the applied voltage is continuously raised, the porous light emitting layer 2 instantaneously breaks down, and cracks are generated in the light emitting element 1 and are destroyed.

Of course, when the light emitting element 1 which immersed the silicone oil was wash | cleaned with organic solvents, such as acetone, and it filled with a micropore part again with gas, it confirmed that light emission was easily carried out and it recovered. Of course, light was emitted even when the minute holes were round holes.

In addition, when the microporous portion was impregnated with a conductive solution, for example, an acetic acid aqueous solution, a short circuit occurred and no light was emitted.

From the above, the biggest feature of the light emitting element in the configuration of the present invention is that the light emitting layer 2 has micropores continuous on the surface, and gas is filled or vacuumed in the micropores. When electrons emitted from the outside enter the inside of the light emitting layer 4, the electrons are accelerated by repeatedly creeping discharge along the minute hole. The accelerated electrons collide with the emission center of the phosphor particles and emit excitation light. In the state where the microporous portion is filled with the silicone oil or the conductive solution, electrons are difficult to move or short circuit occurs, so that no creeping discharge occurs and consequently no light emission.

In this embodiment, although the size of a micropore is several hundred micrometers or less, when it becomes a several mm or more, care | attention is needed because an air discharge may be reached and an element may be destroyed. Empirically, the phosphor particles 3 are packing in point contact. Ideally, a porous having an apparent porosity of 10% or more and less than 100% is preferable.

The reason for forming the insulating layer 4 as in the above embodiment is that

a. In order to raise the surface resistance of the fluorescent substance particle 3 so that surface discharge is easy to generate | occur | produce,

b. In order to protect the phosphor particles from dielectric breakdown and ultraviolet rays,

c. This is to release more electrons by the secondary electron emission action such as MgO and consequently to make creeping discharge more likely to occur.

In addition, although the thickness of the porous light-emitting body layer 2 is not specifically limited, it confirmed that light emission in the range of 10 micrometers-3 mm. Of course, if a short circuit does not occur, it will light from a few micrometers.

(Embodiment 9)

In Embodiment 9, the case where the 1st electrode 6 and the 2nd electrode 7 are formed along the dielectric layer 10 and the porous light-emitting body layer 2 is demonstrated, referring FIG. 22 is a cross-sectional view of the light emitting element 1 in the present embodiment. 6 is a first electrode, 7 is a second electrode, 3 is phosphor particles, 4 is an electrical insulator layer, 2 is a porous light emitting layer, and 10 is a dielectric layer. As shown in Fig. 6, the porous light-emitting layer 2 is composed of the phosphor particles 3 as a main component, and the one in which the surface of the phosphor particles 3 is covered with the insulator layer 4 is used.

The phosphor particles 3 have three kinds of BaMgAl ₁₀ O ₁₇ : Eu ²⁺ (blue), Zn ₂ SiO ₄ : Mn ²⁺ (green), and YBO ₃ : Eu ³⁺ (red) having an average particle diameter of 2 to 3 µm. In order to obtain desired light emission of the inorganic compound of, it is possible to use each alone or a mixture of these.

In the present embodiment, the blue phosphor particles 3 were used to form the insulating layer 4 of the insulating inorganic material made of MgO on the surface thereof. Phosphor particles were added to the Mg precursor complex solution, stirred, extracted and dried, and then thermally treated at 400 to 600 ° C. in air to form a coating layer having a uniform MgO shown in FIG. 6 on the surface of the phosphor.

First, the manufacturing method of FIG. 22 of the light emitting element of this embodiment is demonstrated. 50 mass% of phosphor particle powder (3) coated with the insulating layer (4) and 50 mass% of an aqueous colloidal silica solution are mixed and slurried. Next, a dielectric layer 10 having a diameter of 15 mm and a thickness of 1 mm (the plate-shaped sintered body mainly composed of BaTiO ₃ having a second electrode 7 formed thereon) was etched with an Ag electrode paste having a thickness of about 50 μm. The slurry was applied to the other side of the first electrode 6) and dried in 100 to 150 ° C. for 10 to 30 minutes in a dryer, so that the porous light-emitting layer 2 having a thickness of about 100 μm in the dielectric layer 10. ) Was laminated. In addition, a transparent substrate (glass plate) 8 coated with a transparent second electrode (indium-tin oxide alloy (ITO), thickness: about 0.1 μm) 7 was laminated on the top surface of the porous light emitting layer 2. Thereby, the light emitting element 1 in which the pair of electrodes 6 and 7 were sandwiched between the dielectric layer 10 and the porous light emitting layer 2 was obtained.

Next, the light emitting action of the light emitting element 1 will be described with reference to FIGS. 22 and 17. As shown in FIG. 22, in order to drive the light emitting element 1, an alternating electric field is applied between the first electrode 6 and the second electrode 7. By application of the voltage, primary electrons (e-) 24 are emitted by polarization reversal in the dielectric layer 10. At this time, ultraviolet rays or visible light are generated. The primary electrons (e-) collide with the phosphor particles (3) and the insulating layer (4) of the porous light emitting layer (2), resulting in surface discharge, and a large number of secondary electrons (e-) 25 are generated. As a result, the generated electrons or ultraviolet rays collide with the emission center of the phosphor, and the phosphor particles 3 are excited to emit light. In addition, polarization inversion is repeated in the dielectric layer by application of an alternating electric field. As a result, electrons are generated and charge is injected into the porous light emitting layer, resulting in creeping discharge. Creeping discharges continue to occur while an electric field is applied, and at this time, the generated electrons or ultraviolet rays collide with the emission center of the phosphor, and the phosphor particles 3 are excited to emit light.

In addition, by changing the waveform of the alternating current electric field to be applied from a sine wave or a sawtooth wave to a rectangular wave and raising the frequency from several hundred Hz to several thousand Hz, the emission of electrons and ultraviolet rays due to creeping discharge is extremely intense, and the luminescence brightness is improved. In addition, a burst wave is generated as the voltage of the alternating electric field increases. The generation frequency of the burst wave is generated just before the peak in the sine wave and at the peak in the sawtooth wave or the rectangular wave, and the emission luminance is improved by raising the voltage of the burst wave. Once the creeping discharge is started, ultraviolet rays and visible light are also generated, so it is necessary to suppress deterioration of the phosphor particles 3 due to these light rays, and it is preferable to reduce the voltage after the start of light emission.

In the present embodiment, when a voltage of about 0.5 to 1.0 kV / mm is applied to the thickness of the dielectric layer 10 using an alternating current power source, the primary electron emission (e-) 24 due to polarization inversion and the two due to creepage discharges are applied. The secondary electrons (e-) 25 were generated, and then light emission was started. In addition, the electric current value at the time of discharge was 0.1 mA or less. Moreover, when light emission started, light emission continued even if voltage was reduced to 50 to 80% at the time of application, and it was confirmed that it was light emission of high brightness, high contrast, high recognition, and high reliability. Moreover, it became possible to manufacture the light emitting device which has the light emission efficiency of about 2-5 lm / w.

In addition, although driving was performed in air | atmosphere in this embodiment, it confirmed that light emission was carried out similarly even if it carried out in oxygen, nitrogen, an inert gas, or in reduced pressure gas.

Although the light emitting element 1 in this embodiment is a structure which is structurally close to inorganic EL (ELD), a structure and a mechanism are completely different. First, as described in the Background Art regarding the constitution, the phosphor used for the inorganic EL is a light emitting body composed of a semiconductor represented by ZnS: Mn ²⁺ , GaP: N, etc. The phosphor particles in the present embodiment (9) Either an insulator or a semiconductor may be sufficient. That is, even when using the fluorescent substance particle | grains of an extremely low resistance value, since it is uniformly coat | covered with the insulating layer 4 which is an insulating inorganic substance, creeping discharge can continue to emit light without shorting. Regarding the phosphor layer, the thickness of the submicron-several micrometer in the inorganic EL is a porous body of several micrometers to several hundred micrometers in the ninth embodiment. In the ninth embodiment, the light emitting layer is porous.

About a porous form, it is packing of the grade which the fluorescent substance particle contacted from the result observed with SEM (scanning electron microscope).

In addition, as the phosphor particles, an ultraviolet light-emitting powder used in a current plasma display (PDP) was used, but ZnS: Ag (blue), ZnS: Cu, Au, Al (green), used as a cathode ray tube (CRT), The same luminescence was also observed in Y ₂ O ₃ : Eu (red). In the fluorescent substance for CRT, creeping discharge is unlikely to occur because of low resistance, but when coated with the insulating layer 4, creeping discharge is likely to occur, and light emission becomes easy.

In addition, the present invention is a light emitting device in which creeping discharge occurs in a rush to reach the light emission starting from the electrons emitted by polarization inversion of the dielectric. Therefore, when a system having a new function of colliding electrons in addition to polarization inversion is added to the porous light emitting layer 2, it is expected to emit light easily.

In addition, in producing the slurry of the fluorescent substance particle 3 in this embodiment, the colloidal silica aqueous solution was used, but it confirmed that the same result was obtained even if it used the organic solvent. Screen printing is performed on the surface of the dielectric layer 10 using the slurry which knead | mixed 45 mass% of (alpha)-terpineol and 5 mass% of ethyl cellulose with respect to 50 mass% of fluorescent substance particles, and 400-600 degreeC in air | atmosphere By heat-processing for 60 minutes, the porous light emitting layer 23 of several micrometers-several tens of micrometers in thickness can be produced. In this case, if the heat treatment temperature is increased too much, the phosphor is easily deteriorated, so temperature management and heat treatment atmosphere management become important. Moreover, even if the inorganic fiber 18 is contained in this organic slurry, the same result is obtained.

Further, in the present embodiment was used as the dielectric BaTiO _{3, SrTiO 3, CaTiO 3, MgTiO} 3, PZT (PbZrTiO 3), it was confirmed that the same effect is also obtained by using a dielectric such as PbTiO _3. Moreover, a sintered compact may be used for a dielectric layer, and the dielectric layer obtained by thin film formation processes, such as sputter | spatter, CVD, vapor deposition, and a sol gel, may be used.

In this embodiment, although a sintered compact was used as the dielectric layer, light emission is possible even if a constitution comprising a powder of the dielectric and a binder is employed. That is, applying a metal on the Al substrate, α- terpineol kneaded to come to 40% by mass, 5% by mass ethyl cellulose to a powder mixture of glass powder, 15 mass% relative to BaTiO ₃ powder, 40% by weight slurry, and dried It is also possible to use the dielectric layer comprised from dielectric particle and binder by heat-processing at 400-600 degreeC in air | atmosphere afterwards.

In addition, although blue fluorescent substance particle was used in this Embodiment, it turns out that the same effect is used even if it uses red or green. In addition, blue, red and green mixed particles have the same effect.

According to the light emitting element of this embodiment, since it is light emission by creeping discharge, since a thin film formation process is not used for conventional phosphor layer formation and a vacuum system or a carrier multiplication layer are not needed, a structure is simple and a process figure It is easy.

In addition, although ITO was used for the electrode 7, it is also possible to use the translucent board | substrate with which copper wiring was given as a substitute for ITO. The copper wiring is formed in a fine mesh shape, the opening ratio (ratio of the entire portion where no wiring has been performed) is 90%, and the transmission of light is almost inferior to that of a translucent substrate having an ITO film. In addition, copper is suitable because it has a very low resistance and greatly contributes to the improvement of luminous efficiency compared with ITO. In addition to the copper, gold, silver, platinum, and aluminum can be used as the metal for fine wiring.

(Embodiment 10)

Next, the tenth embodiment will be described with reference to FIG. 23 for the production method and the light emission effect. The description of the same code | symbol as FIG. 22 may be abbreviate | omitted. The Ag paste of mesh shape (about 5-10 mesh) was printed and etched on the other surface of the dielectric 10 in which the 1st electrode 6 used by FIG. 22 was formed, and the 2nd electrode 7 was formed. . Thereafter, a slurry of the phosphor particle powder 3 and the colloidal silica solution is applied to the upper surface of the second electrode 7 and dried for 10 to 30 minutes at 100 to 150 ° C. in the dielectric layer 10. The porous light emitting layer 2 having a thickness of about 100 μm was laminated on the surface of the substrate. As a result, the second electrode 7 was formed between the dielectric layer 10 and the porous light emitting layer 2, and the first electrode 6 was obtained with the light emitting element 1 formed outside the dielectric layer 10. . In the light emitting method as in the case of FIG. 22, an alternating electric field is applied between the first electrode 6 and the second electrode 7. By the application of voltage, primary electrons (e-) 24 are emitted by polarization reversal in dielectric layer 10. Ultraviolet rays or visible light are generated at this time. The primary electrons (e-) collide with the phosphor particles (3) and the insulating layer (4) of the porous light emitting layer (2), resulting in surface discharge, and a large number of secondary electrons (e-) 25 are generated. As a result, the generated electrons or ultraviolet rays collide with the emission center of the phosphor, and the phosphor particles 3 are excited to emit light. In addition, the inversion of the polarization is repeated in the dielectric layer by the application of an alternating electric field. As a result, electrons are generated and charge is injected into the porous light emitting layer, whereby creeping discharge occurs. Creeping discharges continue to occur while an electric field is applied, and at this time, the generated electrons or ultraviolet rays collide with the emission center of the phosphor, and the phosphor particles 3 are excited to emit light.

Of course, as in Fig. 22, by changing the waveform of the alternating electric field to be applied from a sine wave or a sawtooth wave to a rectangular wave, or raising the frequency from tens of Hz to several thousand Hz, electron emission and creepage discharge during polarization inversion become more intense, thereby improving luminescence brightness. . In addition, a burst wave is generated by raising the voltage value of the alternating electric field. The burst wave occurs at the time of polarization inversion of the dielectric layer 10. The generated frequency is generated just before the peak in the sine wave and at the peak in the sawtooth wave or the rectangular wave, and the emission luminance is improved by raising the peak voltage of the burst wave.

Once the creeping discharge starts, as described above, the discharge is repeated in series and constantly generates ultraviolet rays and visible light. Therefore, deterioration of the phosphor particles 2 due to the light rays needs to be suppressed. It is preferable to reduce.

In the case of FIG. 23, when a voltage of about 0.7 to 1.2 kV / mm is applied to the thickness of the dielectric layer 10, the primary electron emission (e-) 24 and the surface discharge shown in FIG. Secondary electrons (e-) 25 were generated, and then light emission was started.

Differences in the light emission of Figs. 22 and 23 are likely to occur violently in the former in the porous light emitting layer 2, but in the latter, the occurrence of the surface discharge is slightly weakened and the luminance is slightly weakened.

Further, the reason why the second electrode 7 has a mesh shape in FIG. 23 is that the primary electrons (e-) 24 shown in FIG. 17 generated by polarization inversion are easily released into the porous light emitting layer 2. This is because if the electrode 7 having a uniform thickness is formed, the primary electrons (e-) 24 shown in Fig. 17 are less likely to be emitted to the porous light emitting layer 2.

In addition, in the case of FIG. 23, although the coating of MgO etc. was not previously performed as the insulating layer 4, the colloidal silica used as a binder functioned as the insulating layer 4. As shown in FIG.

(Embodiment 11)

Next, the case where the pair of electrodes 6 and 7 are both formed at the boundary between the dielectric layer 10 and the porous light emitting layer 2 will be described with reference to FIG. 24. 24 is a sectional view of the light emitting element 1 according to the eleventh embodiment. 6 is a first electrode, 7 is a second electrode, 3 is phosphor particles, 2 is a porous light emitting layer, and 10 is a dielectric layer. The porous light emitting layer 2 is composed of phosphor particles 3 and ceramic fibers 18 as main components. The phosphor particles 3 have three kinds of inorganic materials: BaMgAl ₁₀ O ₁₇ : Eu ²⁺ (blue), ZnSiO ₄ : Mn ²⁺ (green), and YBO ₃ : Eu ³⁺ (red) having an average particle diameter of 2-3 μm. In order to obtain desired luminescence of a compound, individual or a mixture of these is used.

Next, the manufacturing method and the light emitting action of FIG. 24 will be described. First, Ag paste is applied and etched on one surface of the dielectric sintered body 10 used in FIG. 22 to form a pair of electrodes 6 and 7. Next, a slurry obtained by kneading 45 mass% of the phosphor particles, 10 mass% of the inorganic fiber powder, 40 mass% of the α-terpineol, and 5 mass% of the ethyl cellulose was applied, dried, and then thermally treated at 400 to 600 ° C. in the air. The porous light emitting layer 2 having a thickness of about 50 μm is laminated on the dielectric layer 10. Thereby, the pair of electrodes 6 and 7 obtains the light emitting element 1 formed at the boundary between the dielectric layer 10 and the porous light emitting layer 2.

In the light emitting method, as in the case of FIG. 22, an alternating electric field is applied between the first electrode 6 and the second electrode 7. By the application of voltage, primary electrons (e-) 24 are emitted by polarization reversal in dielectric layer 10. At this time, ultraviolet rays or visible light are generated. The primary electrons (e-) collide with the phosphor particles (3) and the ceramic fibers (18) of the porous light emitting layer (2), resulting in surface discharge, and a large number of secondary electrons (e-) 25 are generated. As a result, the generated electrons or ultraviolet rays collide with the emission center of the phosphor, and the phosphor particles 3 are excited to emit light. In addition, the inversion of the polarization is repeated in the dielectric layer by the application of an alternating electric field. Further, electrons are generated accordingly, and charge is injected into the porous light emitting layer, resulting in creeping discharge. Creeping discharge is generated continuously while an electric field is applied. At this time, the generated electrons or ultraviolet rays collide with the emission center of the phosphor, and the phosphor particles 3 are excited to emit light.

Of course, by changing the waveform of the alternating electric field to be applied from a sine wave or a sawtooth wave to a rectangular wave, or raising the frequency from tens of Hz to several thousand Hz, electron emission and creepage discharge during polarization inversion are violently enhanced, thereby improving luminescence brightness. In addition, a burst wave is generated by raising the voltage value of the alternating electric field. The burst wave occurs at the polarization inversion of the dielectric layer 10. The generated frequency is generated immediately before the peak in the sine wave and at the peak in the sawtooth or rectangular wave, and the emission luminance is improved by raising the peak voltage of the burst wave.

Once the creeping discharge starts, as described above, the discharge is repeated in series and generates ultraviolet rays and visible light constantly. Therefore, it is necessary to suppress deterioration of the phosphor particles 3 due to light rays, It is desirable to reduce.

In this embodiment, when a voltage of about 0.7 to 1.2 kV / mm is applied to the thickness of the dielectric using an AC power supply, electron emission and creeping discharge due to polarization inversion occur, and then light emission is started. In addition, FIG. 24 also shows that a pair of electrodes are all formed in the boundary of a dielectric layer and a porous light-emitting layer.

(Embodiment 12)

25, the pair of electrodes 6 and 7 in this invention are arrange | positioned on the upper surface of a dielectric layer, and the porous light-emitting body layer 2 is laminated | stacked through this pair of electrodes, The case where the other electrode 70 is arrange | positioned on the upper surface of this porous light emitting layer 2 is demonstrated.

25 is a cross-sectional view of the light emitting element 1 according to the present embodiment. 6 and 7 are a pair of electrodes, 6 is a first electrode, 7 is a second electrode, 3 is a phosphor particle, 4 is an electrical insulator layer, 2 is a porous light emitting layer, 10 is a dielectric layer, and 70 is a third electrode. As shown in Fig. 6, the porous light-emitting layer is composed of the phosphor particles 3 or the main component thereof. In this embodiment, the surface of the phosphor particles 3 is covered with the insulator layer 4 is used. .

The phosphor particles 3 have three kinds of inorganic materials: BaMgAl ₁₀ O ₁₇ : Eu ²⁺ (blue), ZnSiO ₄ : Mn ²⁺ (green), and YBO ₃ : Eu ³⁺ (red) having an average particle diameter of 2-3 μm. In order to obtain desired luminescence of a compound, individual or a mixture of these is used.

In the present embodiment, the blue phosphor particles 3 were used to form an insulator layer 4 made of an insulating inorganic substance made of MgO on the surface thereof. The phosphor particles 11 were added to the Mg precursor complex solution, stirred for a long time, extracted and dried, and then thermally treated at 400 to 600 ° C. in the air, thereby forming a uniform coating layer of the MgO, that is, the insulator layer 4. It formed in the surface of the particle | grains (3).

First, the manufacturing method of the light emitting element in this Embodiment 12 shown in FIG. 25 is demonstrated. 50 mass% of the fluorescent substance particles 3 with which the insulator layer 4 was coated, and 50 mass% of aqueous colloidal silica solution are mixed and slurryed. Next, a dielectric layer 10 having a diameter of 15 mm and a thickness of 1 mm having a first electrode 6 and a second electrode 7 formed thereon (a plate-shaped sintered body composed mainly of BaTiO ₃ as an Ag electrode paste on its upper surface). Is applied to the first electrode 6 and the second electrode 7 by etching a thickness of 30 μm through a pair of electrodes, that is, the first electrode 6 and the second electrode 7. Then, the porous light-emitting layer 2 having a thickness of about 100 μm was laminated on the dielectric layer 10 by drying at a temperature of 100 to 150 ° C. for 10 to 30 minutes with a drier. A glass (not shown) coated with a transparent electrode (indium-tin oxide alloy (ITO), thickness of 0.1 μm) 70 was laminated on the upper surface of the porous light emitting layer 2. As a result, a pair of electrodes 6 and 7 are formed at the boundary between the dielectric layer 10 and the porous light emitting layer 2, and the third electrode 70 is formed on the upper surface of the porous light emitting body. Element 1 was obtained. Under the present circumstances, you may use the inorganic fiber board which carried phosphor particle powder as a porous light emitting layer.

Next, the light emission effect of this light emitting element 1 is demonstrated. An alternating electric field is applied between the first electrode 6 and the second electrode 7. By the application of the voltage, the primary electrons (e-) 24 shown in FIG. 17 are emitted by polarization inversion in the dielectric layer 10. At this time, ultraviolet rays or visible light are generated. Then, by applying an alternating electric field between another electrode, that is, the electrode 70 and at least one of the pair of electrodes, the primary electrons (e-) 24 shown in FIG. 17 are phosphors of the porous light emitting layer 2. It collides with the particle | grains 3 and the insulating layer 4, and it is surface discharge, and many secondary electrons (e-) 25 shown in FIG. 17 generate | occur | produce. As a result, the generated electrons or ultraviolet rays collide with the emission center of the phosphor, and the phosphor particles 3 are excited to emit light. In addition, the inversion of polarization is repeated in the dielectric layer by application of an alternating electric field. As a result, electrons are generated and charge is injected into the porous light emitting layer, resulting in creeping discharge. Creeping discharges continue to occur while an electric field is applied, and at this time, the generated electrons or ultraviolet rays collide with the emission center of the phosphor, and the phosphor particles 3 are excited to emit light.

At this time, by changing the waveform of the alternating electric field to be applied from a sine wave or a sawtooth wave to a rectangle, and raising the frequency from several hundred Hz to several thousand Hz, electron emission and creepage discharge at the time of polarization inversion are generated more intensively, and the luminescence brightness is improved. .

In addition, a burst wave is generated by raising the voltage value of the alternating electric field. The burst wave is generated at the polarization inversion of the dielectric layer 10. The generated frequency is generated immediately before the peak in the sine wave and at the peak in the sawtooth wave or the rectangular wave, and the emission luminance is improved by raising the voltage of the burst wave. Once the creeping discharge is started, as described above, the discharge is repeated in series and generates ultraviolet rays and visible light constantly. Therefore, it is necessary to suppress the deterioration of the phosphor particles 3 due to the light rays. It is preferable to reduce this.

In this embodiment, in polarization inversion, an electric field of about 0.65 to 1.3 kV / mm is applied to the thickness of the dielectric layer 10. Thereafter, by applying an alternating electric field of about 0.5 to 1.0 kV / mm to the thickness of the light emitting element 1 using an AC power source, primary electron emission and creeping discharge occurred, and then light emission was started. The larger the electric field applied during polarization reversal promotes the generation of electrons, but when too small, the emission of electrons is insufficient.

In addition, the electric current value at the time of discharge was 0.1 mA or less. Moreover, when light emission started, light emission continued even if voltage was reduced to 50 to 80% at the time of application, and it was confirmed that it was light emission of high brightness, high contrast, high recognition, and high reliability. In blue conversion, it became possible to manufacture the light emitting device which has the luminous efficiency of 2-5lm / W.

In Embodiment 12, although driving was performed in air | atmosphere, it confirmed that light emission was carried out similarly even if it implemented in oxygen, nitrogen, an inert gas, or in reduced pressure gas.

The light emitting element 1 according to the twelfth embodiment has a structure close to the inorganic EL (ELD), but the structure and mechanism are completely different. First, regarding the structure, as described in the background art, the phosphor used for the inorganic EL is a light emitting body consisting of a semiconductor represented by ZnS: Mn ²⁺ , GaP: N, etc., but the phosphor particles in the first embodiment May be either an insulator or a semiconductor. That is, even when using phosphor particles of a semiconductor having extremely low resistance value, as described above, the phosphor particles 3 are uniformly covered with the insulator layer 4 which is an insulating inorganic material, and thus continue with creeping discharge without short circuit. Can be made to emit light. In the inorganic EL, the phosphor layer has a thickness of submicron to several micrometers, whereas in the present embodiment, it is a porous body of several micrometers to several hundred micrometers. In the present embodiment, the light emitting layer is porous.

About a porous form, it is packing of the grade which the fluorescent substance particle contacted from the result observed with SEM (scanning electron microscope).

In addition, as the phosphor particles, an ultraviolet light-emitting powder used in a current plasma display (PDP) was used, but ZnS: Ag (blue), ZnS: Cu, Au, Al (green), used as a cathode ray tube (CRT), The same luminescence was also observed in Y ₂ O ₃ : Eu (red). In the phosphor for CRT, since the resistance value is low, creeping discharge is hardly generated. Therefore, it is preferable that the surface of the phosphor is coated with the insulating layer 4 to facilitate the generation of creeping discharge and to emit light.

The present invention is a light emitting device that generates a large amount of secondary electrons and reaches luminescence by sequentially creeping discharge from the primary electrons emitted by polarization inversion of the dielectric. Therefore, when a system having a new function of colliding electrons in addition to polarization inversion is added to the porous light emitting layer 2, it is expected to emit light easily.

In addition, in producing the slurry of the fluorescent substance particle 3 in this embodiment, although the colloidal silica solution aqueous solution was used, it confirmed that the same result was obtained even if it used the organic solvent. Screen printing is carried out on the surface of the dielectric layer 10 using a slurry obtained by kneading 45 mass% of α-terepineol and 5 mass% of ethyl cellulose with respect to 50 mass% of phosphor particles, and 400 to 600 캜 and 10 to 10 in the air. By heat-processing for 60 minutes, the porous light emitting layer 23 of several micrometers-tens of micrometers thickness can be manufactured. In this case, if the heat treatment temperature is increased too much, the phosphor is easily deteriorated, so temperature management and heat treatment atmosphere management become important. In addition, the same result is obtained even if inorganic fiber 18 is contained in this organic system slurry.

In addition, although BaTiO ₃ was used as the dielectric in the present embodiment, it was confirmed that similar effects were obtained even when dielectrics such as SrTiO ₃ , CaTiO ₃ , MgTiO ₃ , PZT (PbZrTiO ₃ ), and PbTiO ₃ were used. Moreover, a sintered compact may be used for a dielectric layer, and the dielectric layer obtained by thin film formation processes, such as sputter | spatter, CVD, vapor deposition, and a sol gel, may be used.

In this embodiment, although a sintered compact was used as the dielectric layer, light emission is possible even if a constitution comprising a powder of the dielectric and a binder is employed. That is, on the Al metal substrate, a slurry in which 40 mass% of α-terpineol and 5 mass% of ethyl cellulose was kneaded was applied to a powder mixed with 15 mass% of glass powder with respect to 40 mass% of BaTiO ₃ powder, It is also possible to use the dielectric layer which consists of a dielectric particle and a binder by heat-processing at 400-600 degreeC in air after drying.

In addition, although blue phosphor particle was used in this embodiment, it turns out that the same effect is used even if it uses red or green. In addition, blue, red, and green mixed particles have the same effect. According to the light emitting element of this embodiment, since it is light emission by surface discharge, since a thin film formation process is not used for conventional phosphor layer formation and a vacuum system or a carrier multiplication layer are not needed, a structure is simple and it is easy to process. Do.

Although ITO was used for the electrode 70, it is also possible to use the translucent board | substrate with which copper wiring was given as a substitute for ITO. The copper wiring is formed in a fine mesh shape, the aperture ratio (ratio relative to the entire portion where no wiring has been performed) is 90%, and the light transmission is almost inferior to that of the translucent substrate having the ITO film. In addition, copper is suitable because it has a very low resistance and greatly contributes to the improvement of luminous efficiency compared with ITO. In addition to the copper, gold, silver, platinum, and aluminum can be used as the metal for fine wiring.

(Embodiment 13)

Next, with reference to FIG. 26, a manufacturing method and a light emitting operation will be described with reference to FIG. In the present embodiment, the first electrode 6 is formed on the lower surface and the second electrode 7 is formed on the upper surface with the dielectric layer 10 interposed therebetween. The description of the same code | symbol as FIG. 1 may be abbreviate | omitted. Embodiment 12 by printing and etching Ag paste on the front surface of the 2nd electrode 7 and the lower surface in the center of the upper surface using the same dielectric 10 as used in Embodiment 12, It was formed in the same manner as each. Thereafter, the slurry containing the phosphor particles 3 used in Embodiment 12 is applied to the surface of the second electrode 7 and dried in a dryer at a temperature of 100 to 150 ° C. for 10 to 30 minutes to form the dielectric layer 10. ), A porous light emitting layer 2 having a thickness of about 100 mu m was laminated. Thereafter, a glass plate (not shown) coated with a transparent electrode 70 (indium-tin oxide alloy (ITO), thickness 0.1 μm) was laminated on the top surface of the porous light emitting layer 2 in the same manner as in the twelfth embodiment. . As a result, a pair of electrodes 6 and 7 are formed on both sides of the dielectric layer 10, and the porous light emitting layer 2 is laminated on the upper surface of the dielectric 10 via the second electrode 7, and also porous. The light emitting element 1 having the cross-sectional structure as shown in FIG. 26 in which the third electrode 70 is formed on the upper surface of the light emitting body was obtained.

In order to drive the light emitting element 1, an alternating electric field is applied between the first electrode 6 and the second electrode 7. By the application of voltage, primary electrons (e-) 24 are emitted by polarization reversal in dielectric layer 10. At this time, ultraviolet rays or visible rays are generated. Subsequently, by applying an alternating electric field between the third electrode 70 and at least one of the pair of electrodes, the primary electrons e- are discharged from the phosphor particles 3 and the insulating layer 4 of the porous light emitting layer 2. And surface discharge, and many secondary electrons (e-) 25 are generated. As a result, the generated electrons or ultraviolet rays collide with the emission center of the phosphor, and the phosphor particles 3 are excited to emit light. In addition, the inversion of polarization is repeated in the dielectric layer by application of an alternating electric field. As a result, electrons are generated and charge is injected into the porous light emitting layer, whereby creeping discharge occurs. Creeping discharges continue to occur while an electric field is applied, and at this time, the generated electrons or ultraviolet rays collide with the emission center of the phosphor, and the phosphor particles 3 are excited to emit light.

In the thirteenth embodiment, as described above, in the same manner as in the twelveth embodiment, the polarization inversion is performed by changing the waveform of the alternating electric field to be applied from a sine wave or a sawtooth wave to a square wave or raising the frequency from several hundred Hz to several thousand Hz. Electron emission and surface discharge generate | occur | produce more violently, and light emission brightness improves. In addition, a burst wave is generated by raising the voltage value of the alternating electric field. The burst wave occurs at the time of polarization inversion of the dielectric layer 10. The generated frequency is generated just before the peak in the sine wave and at the peak in the sawtooth wave or the rectangular wave, and the emission luminance is improved by raising the peak voltage of the burst wave.

Once the creeping discharge is started, the discharge is repeated in a chain and continuously generates ultraviolet rays and visible light. Therefore, it is necessary to suppress the deterioration of the phosphor particles 3 due to the light rays, and to reduce the voltage after the start of light emission. desirable.

In the thirteenth embodiment, the primary electrons are emitted by polarization inversion by applying a voltage of about 0.84 to 1.4 kV / mm to the first electrode 6 and the second electrode 7 with respect to the thickness of the dielectric layer 10. After this is done, an alternating electric field of about 0.7 to 1.2 kV / mm is applied to either the first electrode 6 or the second electrode 7 and the electrode 70 with respect to the thickness of the light emitting element 1. Creeping discharge generated a large amount of secondary electrons, and then light emission was started.

In addition, the current value at the time of discharge is 0.1 mA or less, and when light emission starts, light emission continues even if voltage is reduced to 50 to 80% at the time of application, and it is light emission of high brightness, high contrast, high recognition, and high reliability. Confirmed. In blue conversion, it became possible to manufacture the light emitting device which has the luminous efficiency of 2-5lm / W.

In the light emitting element of the thirteenth embodiment, as shown in FIG. 26, the second electrode 7 formed on the upper surface of the dielectric layer 10 is partially formed rather than formed on the entire surface. This is to prevent primary electrons emitted by polarization reversal from being shielded by the electrode itself and to introduce them into the porous light-emitting layer 2 efficiently. Instead of forming the electrode partially as described above, it may be a mesh-shaped electrode, and may be a shape in which electrons generated by polarization reversal are smoothly emitted to the porous light emitting layer 2.

In addition, in FIG. 26, when an alternating voltage is applied, when a voltage is applied between the first electrode 6 and the third electrode 70, and when the second electrode 7 and the third electrode 70 are used. The luminance hardly changed when a voltage was applied in between.

(Embodiment 14)

Next, with reference to FIG. 27, Embodiment 14, that is, a pair of electrodes 6 and 7 is arrange | positioned at the lower surface of the dielectric layer 10, and the porous light emitting layer 2 is laminated | stacked on the upper surface, and this porous light emitting layer The case where the 3rd electrode 70 is arrange | positioned at the upper surface of (2) is demonstrated.

In the present embodiment, similarly to the twelfth embodiment described above, one in which the surface of the phosphor particles is covered with the insulating layer 4 is used. That is, the phosphor particles formed a coating layer having a uniform MgO on the surface thereof.

The manufacturing method of the light emitting element in this embodiment is demonstrated, referring FIG. 50 mass% of the fluorescent substance particles 11 uniformly coat | covered with the insulator layer 4, and 50 mass% of colloidal silica aqueous solution are mixed, and it slurrys. Next, a dielectric layer 10 having a diameter of 15 mm and a thickness of 1 mm in which the first electrode 6 and the second electrode 7 are formed (a plate-shaped sintered body mainly composed of BaTiO ₃ is formed. The slurry was applied to the upper surface of the first electrode 6 and the second electrode 7 by etching to a thickness of 30 μm, and dried at a temperature of 100 to 150 ° C. for 10 to 30 minutes using a dryer. In this way, the porous light emitting layer 2 having a thickness of about 100 μm was laminated on the dielectric layer 10. Thereafter, a glass (not shown) coated with a transparent electrode (indium-tin oxide alloy (ITO), thickness 0.1 μm) 70 was laminated on the upper surface of the porous light emitting layer 2. As a result, a pair of electrodes 6 and 7 are formed on the lower surface of the dielectric layer 10, the porous light emitting layer 2 is laminated on the upper surface of the dielectric layer 10, and the upper surface of the porous light emitting layer 2 The light emitting element 1 shown in FIG. 27 in which the three electrodes 70 were formed was obtained.

Next, the light emission effect of this light emitting element 1 is demonstrated. An alternating electric field is applied between the first electrode 6 and the second electrode 7. By application of voltage, primary electrons (e-) 24 are emitted by polarization reversal in dielectric layer 10. At this time, ultraviolet rays or visible light are generated. Thereafter, an alternating electric field is applied between the third electrode 70 and at least one of the pair of electrodes 6 and 7 so that the primary electrons e- are formed from the phosphor particles 3 of the porous light emitting layer 2 or the like. It collides with the insulating layer 4, it is creeping discharge, and many secondary electrons (e-) 25 generate | occur | produce. As a result, the generated electrons or ultraviolet rays collide with the emission center of the phosphor, and the phosphor particles 3 are excited to emit light. In addition, the inversion of polarization is repeated in the conductor layer by applying an alternating electric field. As a result, electrons are generated, and charge is injected into the porous light emitting layer, resulting in creeping discharge. Creeping discharges continue to occur while an electric field is applied, and at this time, the generated electrons or ultraviolet rays collide with the emission center of the phosphor, and the phosphor particles 3 are excited to emit light.

At this time, by changing the waveform of the alternating electric field to be applied from a sine wave or a sawtooth wave to a rectangular wave, or raising the frequency from tens of Hz to several thousand Hz, electron emission and creepage discharge during polarization reversal occurred more intensely, and the emission luminance was improved. .

In addition, a burst wave is generated by raising the voltage value of the alternating electric field. The burst wave is generated at the polarization inversion of the dielectric layer 10. The generated frequency is generated immediately before the peak in the sine wave and at the peak in the sawtooth wave or the rectangular wave, and the emission luminance is improved by raising the voltage of the burst wave.

Once the creeping discharge is started, as described above, the discharge is repeated in series and constantly generates ultraviolet rays and visible light. Therefore, it is necessary to suppress the deterioration of the phosphor particles 3 due to the light rays. It is preferable to reduce.

In Embodiment 14, in polarization inversion, an electric field of about 0.4 to 0.8 kV / mm is applied to the thickness of the dielectric layer 10, and then about 0.5 to the thickness of the light emitting element 1 using an AC power source. By applying an alternating electric field of ˜1.0 kV / mm, primary electron emission and creepage discharge occurred, and then light emission was started. In addition, the larger the electric field applied in polarization reversal promotes the generation of electrons, but when too small, the emission of electrons becomes insufficient. In addition, the electric current value at the time of discharge was 0.lmA or less. Moreover, when light emission started, light emission continued even if voltage was reduced to 50 to 80% at the time of application, and it was confirmed that it was light emission of high brightness, high contrast, high recognition, and high reliability. In blue conversion, it became possible to manufacture the light emitting device which has the luminous efficiency of 2-5lm / W.

(Embodiment 15)

A fifteenth embodiment of the present invention will be described with reference to FIG. In the present embodiment, the first electrode 6 is disposed on the lower surface of the dielectric layer 10, and the porous light emitting layer 2 is stacked on the upper surface of the dielectric layer 10, and the upper surface of the porous light emitting layer 2 is provided. The second electrode 7 and the third electrode 70 are arranged.

In the fifteenth embodiment, similarly to the twelfth embodiment described above, a surface of the phosphor particles covered with the insulating layer 4 was used. That is, a coating layer having a uniform MgO was formed on the surface of the blue phosphor particles in the same manner as in Embodiment 12.

About the manufacturing method of the light emitting element of this Embodiment 15, first, 50 mass% of fluorescent substance particles 3 uniformly coat | covered with the above-mentioned insulating layer 4, and 50 mass% of colloidal silica aqueous solution are mixed, and a slurry is produced. . Next, the first electrode 6 was formed with a dielectric layer 10 having a diameter of 15 mm and a thickness of 1 mm (a plate-shaped sintered body composed mainly of BaTiO _{3. The} Ag electrode paste was etched on the bottom surface thereof with a thickness of 30 μm. The slurry is applied to the upper surface of the first electrode 6) and dried for 100 to 150 ° C. for 10 to 30 minutes in a dryer, so that the porous light emitting layer 2 has a thickness of about 100 μm on the dielectric layer 10. ) Was laminated. Further, the Ag electrode paste is etched to have a thickness of 30 μm on the upper surface of the porous light emitting layer 2, and the second electrode 7 is formed on a part of the surface of the porous light emitting layer 2, and then a transparent electrode (indium) A glass plate (not shown) to which a tin oxide alloy (ITO), thickness 0.1 m) 70 was partially applied was laminated. As a result, the first electrode 7 of the pair of electrodes is formed on the lower surface of the dielectric layer 10, the porous light emitting layer 2 is laminated on the upper surface of the dielectric layer 10, and the second electrode 7 is disposed on the upper surface of the dielectric layer 10. And the 3rd electrode 70 were formed and the light emitting element 1 which has the cross-sectional structure of FIG. 28 was obtained.

Next, the light emission effect of this light emitting element 1 is demonstrated. An alternating electric field is applied between the first electrode 6 and the second electrode 7. By the application of voltage, primary electrons (e-) 24 are emitted by polarization reversal in dielectric layer 10. At this time, ultraviolet rays or visible light are generated. Thereafter, by applying an alternating electric field between another electrode, that is, the electrode 70 and at least one of the pair of electrodes, the primary electrons e- are transferred to the phosphor particles 3 and the insulating layer of the porous light emitting layer 2 ( It collides with 4), and it is surface discharge, and many secondary electrons (e-) 25 generate | occur | produce again. As a result, the generated electrons or ultraviolet rays collide with the emission center of the phosphor, and the phosphor particles 3 are excited to emit light. In addition, the inversion of the polarization is repeated in the dielectric layer by applying an alternating electric field. Further, electrons are generated accordingly, and charge is injected into the porous light emitting layer, resulting in creeping discharge. Creeping discharges continue to occur while an electric field is applied, and at this time, the generated electrons or ultraviolet rays collide with the emission center of the phosphor, and the phosphor particles 3 are excited to emit light.

At this time, by changing the waveform of the alternating electric field to be applied from a sine wave or a sawtooth wave to a rectangular wave, or raising the frequency from tens of Hz to several thousand Hz, electron emission and creepage discharge during polarization reversal become more intense, thereby improving luminescence brightness.

In addition, a burst wave is generated by raising the voltage value of the alternating electric field. The burst wave is generated at the polarization inversion of the dielectric layer 10. The generated frequency is generated immediately before the peak in the sine wave and at the peak in the sawtooth wave or the rectangular wave, and the emission luminance is improved by raising the voltage of the burst wave. Once the creeping discharge is started, as described above, the discharge is repeated in series and constantly generates ultraviolet rays and visible light. Therefore, it is necessary to suppress deterioration of the phosphor particles 3 due to light rays, It is preferable to reduce this.

In this embodiment, in polarization inversion, an electric field of about 0.5 to 1.0 kV / mm is applied to the thickness of the dielectric layer 10, and then about 0.5 to the thickness of the light emitting element 1 using an AC power source. By applying an alternating electric field of ˜1.0 kV / mm, primary electron emission and creeping discharge generated a large amount of secondary electrons, and then light emission was started. In addition, in the polarization reversal, if the applied electric field is too small to promote the generation of electrons, the emission of electrons becomes insufficient.

In addition, the electric current value at the time of discharge was 0.1 mA or less. Moreover, when light emission started, light emission continued even if voltage was reduced to 50 to 80% at the time of application, and it was confirmed that it was light emission of high brightness, high contrast, high recognition, and high reliability. In blue conversion, it became possible to manufacture the light emitting device which has the luminous efficiency of 2-5lm / W.

(Embodiment 16)

A light emitting element including an electron emitter, a porous light emitter and a pair of electrodes in this embodiment will be described with reference to FIGS. 29 and 30. In the light emitting device of the present embodiment, the porous light emitter includes inorganic phosphor particles, and the porous light emitter is disposed adjacent to the electron emitter such that the porous light emitter is irradiated by electrons generated from the electron emitter, and a pair of electrodes of the porous light emitter The electric field is provided at least in part. In particular, the electron emitter comprises a cathode electrode, a gate electrode, and a Spindt Type emitter interposed between the two electrodes, and by applying a gate voltage between the cathode electrode and the gate electrode, A light emitting device that emits electrons emitted from a spin type emitter to a porous light emitter to emit light of the porous light emitter will be described.

Fig. 29 is a cross-sectional view of the light emitting device according to the present embodiment, in which 1 is a light emitting device having an overall thickness of about 2 mm, 2 is a porous light emitting layer having a thickness of about 30 μm, and 3 is a phosphor having an average particle diameter of 2 μm. Particles, 4 is an insulating layer having a surface thickness of phosphor particles of 0.5 μm, 100 is a triangular spine-type emitter having a bottom surface of 1 μm, and a height of 1 μm, 6 is a first electrode having a thickness of 200 nm, and 7 is a thickness. Is a second electrode having a thickness of 200 nm, 111 is an anode electrode having a thickness of 150 nm, 112 is a cathode electrode having a thickness of 150 nm, 113 is a gate electrode having a thickness of 200 nm, 116 is an insulating layer having a thickness of 1 μm, A substrate having a thickness of 1.1 mm and 119 are electron emitters having a thickness of 1.1 mm.

First, the manufacturing method of the light emitting element in this embodiment is demonstrated, referring drawings. 30A to 30F illustrate a method of manufacturing the light emitting device illustrated in FIG. 29. As illustrated in FIG. 30A, Au is deposited on the surface of the glass substrate 117 to form the cathode electrode 112. . Instead of Au, Ag, Al, or Ni may be deposited on the cathode electrode 112. The substrate 117 may be ceramic in addition to glass.

Next, in order to form the insulating layer 116 as shown in FIG. 30B, the glass paste is printed on the cathode electrode 112 by screen printing, dried, and baked at 580 ° C. The insulating layer 116 is formed by coating SiO ₂ on the cathode by sputtering instead of screen printing the glass paste, and then developing and etching by UV exposure using a photoresist and a photo mask. It is also possible to use a so-called photolithography technique for selectively forming the insulating layer 116 of SiO ₂ .

Next, as shown in FIG. 30C, after the sputtering film formation, a gate electrode 113 made of A1 is formed on the insulating layer 116 using the technique of photolithography. It is also possible to use Ni for the gate electrode metal instead of Al.

Thereafter, as shown in FIG. 30E, a spin type emitter is formed in a recess between the gate electrodes 113 by a two-step deposition method. Specifically, the substrate shown in FIG. 30C is inclined at an angle of about 20 °, set in a vapor deposition apparatus, and Al ₂ O ₃ as a sacrificial material is deposited while rotating the substrate. As a result, Al ₂ O ₃ is deposited to cover the gate electrode 113, as shown in FIG. 30D, so that an Al ₂ O ₃ layer 118 having a thickness of 200 mm is formed, and deposited on the cathode electrode 112 ( 23) Not. Subsequently, when Mo is deposited as an emitter, vapor deposition is carried out so as to self-align with the concave portions between the gate electrodes 113, and a spin type emitter having a triangular shape of Mo is formed. After that, the sacrificial layer or Mo on the gate electrode 113 is lifted off, and the Mo emitter is oxidized at the time of deposition, so that it is fired at a temperature of 550 ° C., and finally, as shown in FIG. 30E, Mo The glass substrate in which the spin type emitter 100 was formed in the recess between the gate electrodes 113 is obtained. Moreover, as an emitter material, metals, such as Nb, Zr, Ni, and molybdenum steel, can also be used other than Mo, and these emitters can be manufactured according to the method which produced the above-mentioned Mo emitter.

The porous light-emitting body 2 in the present embodiment is composed of the phosphor particles 3 or the main component thereof. In the present embodiment, the surface of the phosphor particles 3 is covered with the insulating layer 4. Used one.

The phosphor particles 3 are, for example, BaMgAl ₁₀ O ₁₇ : Eu ²⁺ (blue), Zn ₂ SiO ₄ : Mn ²⁺ (green), YBO ₃ : Eu ³⁺ (red) having an average particle diameter of 2-3 μm. In order to obtain desired luminescence of the three kinds of inorganic compounds), it is possible to use each alone or a mixture thereof.

In the present embodiment, the blue phosphor particles 3 are used, and an insulating layer 4 of an insulating inorganic material made of MgO is formed on the surface thereof. Specifically, the phosphor particles 3 are added to the Mg precursor complex solution, stirred for a long time, extracted, dried, and then thermally treated at 400 to 600 ° C. in the air, whereby a coating layer having a uniform MgO, that is, an insulating layer 4 Was formed on the surface of the phosphor particles (3). 50 mass% of the fluorescent substance particles 3 coated with the insulator layer 4 mentioned above, and 50 mass% of aqueous colloidal silica solution are mixed and slurried.

Next, a ceramic plate made of inorganic fibers (a ceramic fiber plate having a thickness of about 1 mm and a porosity of about 45% in an Al ₂ O ₃ -CaO-SiO ₂ system) was immersed in the slurry and subjected to a temperature of 100 to 150 캜. By drying for 30 minutes, the powder of fluorescent substance particles is supported on a ceramic plate. Thereafter, Ag electrode paste was etched to a thickness of 30 μm on both surfaces thereof to form a first electrode 6 and a second electrode 7. The ceramic fiber board thus obtained is attached to the electron emitter 119 using colloidal silica, water glass or epoxy resin as shown in FIG. 30F. Next, a glass (not shown) coated with a transparent anode electrode (indium-tin oxide alloy (ITO), thickness 15 µm) 111 is laminated on the upper surface of the porous light-emitting body 2, as shown in FIG. 29. Similarly, the porous light emitting body 2 is formed on the electron emitter 119, and the light emitting element 1 in which an electrode is arranged at a predetermined position is obtained. In addition, since the resistance value of the transparent electrode ITO used as the anode electrode 111 is high, the 1st electrode 6 and the 2nd electrode 7 with respect to the electrode of the light emitting element 1 are inserted as an auxiliary electrode. For this reason, it is also possible to make the anode electrode 111 and the 2nd electrode 7 common, or to make the gate electrode 113 and the 1st electrode 6 common.

In addition, in order to prevent the trajectory of the electrons emitted from the emitter from being greatly pushed, Ag paste may be screen printed on the gate electrode to provide a focusing electrode.

Next, the light emission effect of the light emitting element 1 in this embodiment is demonstrated.

In order to drive the light emitting element 1, a DC field of 800 V and 80 V is first applied between the anode electrode 111 and the cathode electrode 112 of FIG. 29 and between the gate electrode 113 and the cathode electrode 112, respectively. By applying, primary electrons are emitted from the spin type emitter 100 in the direction of the arrow in the figure. The larger the applied electric field promotes the generation of electrons, but when too small, the emission of electrons becomes insufficient.

As described above, primary electrons are emitted and an alternating electric field is applied between the first electrode 6 and the second electrode 7. Primary electrons emitted by the movement of electric charges are multiplied in a rush, and creeping discharges are generated inside the porous light-emitting body 2. Creeping discharges are continuously generated in series, charge transfer occurs around the phosphor particles, and accelerated electrons collide with the emission center, and the porous light emitter 2 is excited to emit light. At this time, ultraviolet rays and visible rays are also generated, and excitation light is emitted also by ultraviolet rays.

In addition, by changing the waveform of the alternating electric field to be applied from a sine wave or a sawtooth wave to a rectangular wave and raising the frequency from several hundred Hz to several thousand Hz, the intensity is generated more intensely than electron emission and creeping discharge, and as a result, the emission luminance is improved. .

Once the creeping discharge is started, the discharge is repeated in a chain, and continuously generates ultraviolet rays and visible light. Therefore, it is necessary to suppress deterioration of the phosphor particles 3 due to the light rays, and to reduce the voltage after the start of light emission. desirable.

Specifically, by applying an alternating electric field of about 0.5 to 1.0 kV / mm to the thickness of the porous light-emitting body 1 using an alternating current power source, creeping discharge occurred with the transfer of charge, and light emission was subsequently started. In addition, the larger the electric field applied at this time promotes the generation of electrons, but when too small, the emission of electrons becomes insufficient.

In addition, the current value at the time of discharge is 0.1 mA or less, and when light emission starts, light emission continues even if voltage is reduced to 50 to 80% at the time of application, and it is light emission of high brightness, high contrast, high recognition, and high reliability. Confirmed. In this manner, a light emitting device having a light emission efficiency of 2.0 lm / W, a luminance of 200 cd / m 2, and a control of 500: 1 in blue conversion could be produced.

In this embodiment, although driving was performed in air | atmosphere, it confirmed that light emission was carried out similarly even if it implemented in oxygen, nitrogen, an inert gas, or in reduced pressure gas.

The light emitting element 1 according to the present embodiment has a structure close to the inorganic EL (ELD) in structure, but the structure and mechanism are completely different. First, regarding the structure, as described in the background art, the phosphor used for the inorganic EL is a light emitting body consisting of a semiconductor represented by ZnS: Mn ²⁺ , GaP: N, and the like. The phosphor particles in the embodiment are insulators. Or any of semiconductors may be sufficient, but insulating fluorescent substance particle is preferable. That is, even when using fluorescent particles of a semiconductor having extremely low resistance value, as described above, the fluorescent particles can be uniformly covered with an insulating inorganic layer of insulating inorganic material so that light can be continuously emitted by creeping discharge without short circuit. . In the inorganic EL, the phosphor layer has a thickness of submicron to several micrometers, whereas in the present embodiment, it is a porous body of several micrometers to several hundred micrometers. In addition, the characteristic in this embodiment is that a light-emitting body is porous.

About a porous form, it is packing of the grade which the fluorescent substance particle contacted by the result of observing with SEM (scanning electron microscope).

In addition, as the phosphor particles, an ultraviolet light-emitting powder used in a current plasma display (PDP) was used, but ZnS: Ag (blue), ZnS: Cu, Au, Al (green), used as a cathode ray tube (CRT), The same luminescence was also confirmed in Y ₂ O ₃ : Eu (red).

The present invention is a light emitting device in which creeping discharge occurs in a rush to reach luminescence based on electrons emitted from the electron emitter 119, and a novel electron emitter for irradiating electrons is provided in the porous light emitter 2 of the present invention. It is estimated that it can be easily emitted in combination with.

In addition, in producing the slurry of the fluorescent substance particle 3 in this embodiment, the colloidal silica aqueous solution was used, but it confirmed that the same result was obtained even if it used the organic solvent. You may prepare the slurry which knead | mixed 45 mass% of (alpha)-terpineol and 5 mass% of ethyl cellulose with respect to 50 mass% of fluorescent substance particles, immerse it in the ceramic fiber board mentioned above, and degrease by heat processing.

In addition, although blue fluorescent substance particle was used in this embodiment, it turned out that the same result is obtained even if it uses red or green. Moreover, the same result was obtained also in blue, red, and green mixed particle. In addition, in this embodiment, although the alternating electric field was applied between the 1st electrode 6 and the 2nd electrode 7, even if it is a direct current electric field, it does not interfere.

According to the light emitting device of the present embodiment, since the light emission is caused by the surface discharge, the thin film formation process is hardly used for forming the phosphor layer as in the prior art, and since the vacuum system or the carrier multiplication layer are not required, the structure is simple and the processing degree It is easy.

(Embodiment 17)

A light emitting element including an electron emitter, a porous light emitter and a pair of electrodes in this embodiment will be described with reference to FIGS. 31 and 32A-G. In the light emitting device of the present embodiment, the porous light emitter includes inorganic phosphor particles, and the porous light emitter is disposed adjacent to the electron emitter such that the porous light emitter is irradiated by electrons generated from the electron emitter, and the pair of electrodes is disposed at least of the porous light emitter. It is provided so that an electric field is applied to a part. In particular, the electron emitter includes a cathode, a gate electrode, and a carbon nanotube interposed between the two electrodes, and the carbon is applied by applying a gate voltage between the cathode and the gate electrode. The light emitting device for emitting the porous light emitter by irradiating the porous light emitter with electrons emitted from the nanotube will be described.

31 is a cross-sectional view of a light emitting device according to the present embodiment, in which 1 is a light emitting element, 2 is a porous light emitter, 3 is a phosphor particle, 4 is an insulating layer, 6 is a first electrode, 7 is a second electrode, and 111 is a light emitting element. An anode electrode, 112 is a cathode electrode, 113 is a gate electrode, 116 is an insulating layer, 117 is a substrate and 127 is carbon nanotubes.

First, the manufacturing method of the light emitting element in this embodiment is demonstrated, referring drawings. 32A-G are views for explaining the manufacturing method of the light emitting device shown in FIG. 31. As shown in FIG. 32A, the cathode electrode 112 is formed by depositing Au on the surface of the glass substrate 117. The method is carried out in the same manner as in the sixteenth embodiment already described. In addition, a ceramic may be sufficient as the board | substrate in this embodiment other than glass. Next, as shown in FIG. 32B, the insulating layer 116 is formed on the cathode electrode 112, and as shown in FIG. 32C, the gate electrode 113 made of Al on the insulating layer 116. As shown in FIG. The method for forming the film was also performed in the same manner as in the sixteenth embodiment already described.

Subsequently, as shown in FIG. 32D, a paste obtained by kneading 45 mass% of α-terpineol and 5 mass% of ethyl cellulose with respect to 50 mass% of carbon nanotubes is recessed between the gate electrodes 113. FIG. Drop it in your wealth. After drying, heat treatment is performed at 400 ° C. in an N ₂ atmosphere to deposit carbon nanotubes in the recesses as shown in FIG. 32E. After this, when the adhesive film is bonded to the surface of the carbon nanotubes and then peeled off, the alignment of the carbon nanotubes is carried out, and the vertically oriented carbon nanotubes which are in a preferred form as an electron emitter as shown in Fig. 32F. Is formed.

It is also possible to pattern the carbon nanotubes by coating the photosensitive carbon nanotube paste on the substrate on which the above-described gate electrode is formed, and exposing and developing using a photomask. It is also possible to use laser irradiation as a process for the vertical orientation of carbon nanotubes. Specifically, after the carbon nanotube film is formed using the paste containing the carbon nanotube, the carbon nanotube is formed on the surface of the film by burning out the organic resin contained in the carbon nanotube film by irradiating a laser. It is a method of exposing and napping.

Next, as in the above-described embodiment 16, the phosphor particle powder was placed on a ceramic plate made of inorganic fibers (a ceramic fiber plate having a thickness of about 1 mm and a porosity of about 45% in an Al ₂ O ₃ -CaO-SiO ₂ system). Was prepared, and Ag electrode paste was etched to a thickness of 30 mu m on both surfaces thereof to form a first electrode 6 and a second electrode 7. As shown in FIG. The ceramic fiber board thus obtained is attached to the electron emitter 119 using colloidal silica, water glass, or an epoxy resin as shown in FIG. 32G. After this, the electron emitter 119 is formed by laminating a glass (not shown) coated with a transparent anode electrode (indium-tin oxide alloy (ITO), thickness 15 μm) 111 on the upper surface of the porous light emitting body 2. The light emitting element 1 in this embodiment as shown in FIG. 31 in which the porous light-emitting body 2 is formed and the electrode is arranged at a predetermined position is obtained.

Next, the light emission effect of the light emitting element 1 is demonstrated. In order to drive the light emitting element 1, first, a direct current electric field of 750 and 80 V is applied between the anode electrode 111 and the cathode electrode 112 of FIG. 31 and between the gate electrode 113 and the cathode electrode 112, respectively. By applying, electrons are emitted from the carbon nanotubes in the direction of the arrow in the figure.

As described above, electrons are emitted and an alternating electric field is applied between the first electrode 6 and the second electrode 7. The electrons emitted in accordance with the movement of the charge multiply exponentially to generate creeping discharges inside the porous light-emitting body 2. Creeping discharges are continuously generated in series, charge transfer occurs around the phosphor particles, and accelerated electrons collide with the emission center, and the porous light emitter 2 is excited to emit light. At this time, ultraviolet rays and visible rays are also generated, and excitation light is emitted also by ultraviolet rays.

Further, by changing the waveform of the alternating electric field to be applied from a sine wave or a sawtooth wave to a rectangular wave, and raising the frequency from several hundred Hz to several thousand Hz, electron emission and creepage discharge occur more violently, and as a result, emission luminance is improved.

Once the creeping discharge is started, as described above, the discharge is repeated in series and generates ultraviolet rays and visible light constantly. Therefore, it is necessary to suppress the deterioration of the phosphor particles 3 due to the light rays. It is preferable to reduce this.

Specifically, by applying an alternating electric field of about 0.5 to 1.0 kV / mm to the thickness of the porous light-emitting body 1 using an alternating current power source, creeping discharge occurred with the transfer of charge, and light emission was subsequently started. In addition, the larger the electric field applied at this time promotes the generation of electrons, if too small, the emission of electrons is insufficient.

In addition, it was confirmed that the current value at the time of discharge was 0.1 mA or less, and light emission continued when the light emission started, even if the voltage was reduced to 50 to 80% at the time of application.

In this embodiment, although driving was performed in air | atmosphere, it confirmed that light emission was carried out similarly even if it implemented in oxygen, nitrogen, an inert gas, or in reduced pressure gas.

In addition, although blue fluorescent substance particle was used in this embodiment, it turned out that the same result is obtained even if it uses red or green. Moreover, the same result was obtained also in blue, red, and green mixed particle.

According to the light emitting device of the present embodiment, since the light emission is caused by the surface discharge, the thin film formation process is hardly used for forming the phosphor layer as in the prior art, and since the vacuum system or the carrier multiplication layer are not required, the structure is simple and the processing degree It is easy.

(Embodiment 18)

33 and 34A-C, a light emitting element including an electron emitter, a porous light emitter and a pair of electrodes in the present embodiment will be described. In the light emitting device of the present embodiment, the porous light emitter includes inorganic phosphor particles, and the porous light emitter is disposed adjacent to the electron emitter such that the porous light emitter is irradiated by electrons generated from the electron emitter, and a pair of electrodes is disposed in the porous light emitter. It is provided so that an electric field is applied to at least one part. In particular, the electron emitter is a surface conduction electron emitting device, which forms a fine gap in the metal oxide film, applies a voltage to an electrode provided in advance in the metal oxide film, applies an electric field to the gap, and generates electrons in the gap. The light emitting element made to irradiate is demonstrated.

33 is a cross-sectional view of the light emitting device according to the present embodiment, in which 1 is a light emitting element, 2 is a porous light emitter, 3 is a phosphor particle, 4 is an insulating layer, 6 is a first electrode, 7 is a second electrode, and 117 is a The substrate, 130 is a gap, 131 is a PdO ultrafine particle, and 132 is a Pt electrode.

First, the manufacturing method of the light emitting element in this embodiment is demonstrated, referring drawings. 34A-C are views for explaining the manufacturing method of the light emitting element in the present embodiment shown in FIG. As shown in FIG. 34A, the Pt electrode 132 is formed on the substrate in a state where a small gap is formed by patterning Pt paste on the surface of the ceramic substrate 17 by screen printing. Next, as shown in FIG. 34B, the Pt electrode 132 is covered with PdO ink by inkjet printing so as to be bridged and fired to form a PdO ultrafine particle film 131 on the Pt electrode 132. Subsequently, by performing electrical treatment, cracks are generated in the PdO ultrafine particle film 31 as shown in FIG. 34C to form a fine gap 30 of about 10 nm. In this way, since the electron emitter of the present embodiment is constituted, the number of processes is also relatively small without using a photolithography process, which is excellent in terms of economy and display enlargement.

Next, as in the above-described Embodiment 16, the phosphor particle powder was placed on a ceramic plate made of inorganic fibers (a ceramic fiber plate having a thickness of about 1 mm and a porosity of about 45% in an A1 ₂ O ₃ -CaO-SiO ₂ system). Was prepared, and Ag electrode paste was etched to a thickness of 30 탆 on both surfaces thereof to form a first electrode 6 and a second electrode 7, respectively. As shown in FIG. 33, the obtained ceramic fiber board is attached to the electron emitter 119 using colloidal silica, water glass, or an epoxy resin.

In this way, the porous light-emitting body 2 is disposed on the electron emitter 119, and the light-emitting element 1 according to the present embodiment as shown in FIG. 33 having an electrode at a predetermined position can be obtained. have.

Next, the light emission effect of this light emitting element 1 will be described. In order to drive the light emitting element 1, first, when a DC voltage of 12 to 16 V is applied between two pt electrodes 132 shown in FIG. 33, a tunnel effect passes through a 10 nm slit from one electrode. Electrons are emitted in the direction, and the porous light emitting body 2 is irradiated.

As described above, electrons are emitted and an alternating electric field is applied between the first electrode 6 and the second electrode 7. The electrons emitted in accordance with the movement of the charge multiply exponentially to generate creeping discharges inside the porous light-emitting body 2. Creeping discharges are continuously generated in series, charge transfer occurs around the phosphor particles, and accelerated electrons collide with the emission center, and the porous light emitter 2 is excited to emit light. At this time, ultraviolet rays and visible rays are also generated, and excitation light is emitted even by ultraviolet rays.

Further, by changing the waveform of the alternating electric field to be applied from a sine wave or a sawtooth wave to a rectangular wave, and raising the frequency from several hundred Hz to several thousand Hz, electron emission and creepage discharge occur more violently, and as a result, emission luminance is improved.

Once the creeping discharge is started, as described above, the discharge is repeated in series and generates ultraviolet rays and visible light constantly. Therefore, it is necessary to suppress the deterioration of the phosphor particles 3 due to the light rays. It is preferable to reduce this.

Specifically, by applying an alternating electric field of about 0.5 to 1.0 kV / mm to the thickness of the porous phosphor 2 using an alternating current power source, charge transfer and creeping discharge occurred, and light emission was subsequently started. In addition, the larger the electric field applied at this time promotes the generation of electrons, but when too small, the emission of electrons becomes insufficient.

In addition, it was confirmed that the current value at the time of discharge was 0.1 mA or less, and light emission continued when the light emission started, even if the voltage was reduced to 50 to 80% at the time of application.

In this embodiment, although driving was performed in air | atmosphere, it confirmed that light emission was carried out similarly even if it implemented in oxygen, nitrogen, an inert gas, or in reduced pressure gas.

In addition, as the phosphor particles, an ultraviolet light-emitting powder used in a current plasma display (PDP) was used, but ZnS: Ag (blue), ZnS: Cu, Au, Al (green), used as a cathode ray tube (CRT), The same luminescence was also confirmed in Y ₂ O ₃ : Eu (red).

The present invention is a light emitting device in which creeping discharge occurs in a rush to reach light emission starting from electrons emitted to the electron emitter 119, and a device having a novel function of irradiating electrons is added to the porous light emitting body 2. It is expected to emit light easily.

In the present embodiment, blue phosphor particles were used, but it was found that the same result can be obtained even when using red or green. Moreover, the same result was obtained also in blue, red, and green mixed particle.

According to the light emitting element of this embodiment, since it is light emission by creeping discharge, since the thin film formation process is hardly used for conventional phosphor layer formation and a vacuum system or a carrier multiplication layer are not needed, a structure is simple and it is easy to process. Do.

In addition, instead of using the electron emitter described in the present embodiment, it is also possible to emit electrons by sandwiching the insulating layer with two electrodes as a pseudo electron emitter and applying an electric field to both electrodes. Specifically, an Ir-Pt-Au alloy is used as the upper electrode, Al is used as the cathode, and Al ₂ O ₃ is used as the insulating layer. The insulating layer is sandwiched by two electrodes, and an electric field is applied between the electrodes. Since electrons are emitted, it is also possible to produce a light emitting element by having a structure which irradiates a porous light emitting body using such an electron emitting body.

(Embodiment 19)

35 and 36A-D, a light emitting element including an electron emitter, a porous light emitter and a pair of electrodes in the present embodiment will be described. In the light emitting device of the present embodiment, the porous light emitter includes inorganic phosphor particles, and the porous light emitter is disposed adjacent to the electron emitter such that the porous light emitter is irradiated by electrons generated from the electron emitter, and a pair of electrodes is disposed in the porous light emitter. The electric field is provided at least in part. In particular, the electron emitter includes an oxide film formed on a surface of a polysilicon thin film, silicon microcrystal, and silicon microcrystal, and emits a porous light emitter by irradiating a porous light emitter with electrons emitted by application of a voltage to the electron emitter. The device will be described.

Fig. 35 is a cross-sectional view of the light emitting device according to the present embodiment, in which 1 is a light emitting element, 2 is a porous light emitter, 3 is a phosphor particle, 4 is an insulating layer, 6 is a first electrode, 7 is a second electrode, and 112 is A cathode electrode, 119 is an electron emitter, 141 is a metal thin film electrode, 145 is polysilicon and 147 is silicon microcrystalline. FIG. 36A-D is a view for explaining the manufacturing method of the light emitting device shown in FIG. 35. As shown in FIG. 36A, by depositing Au on the surface of the glass substrate 143, a cathode is used by photolithography. The electrode 112 is patterned and formed. Subsequently, as shown in Fig. 36B, columnar polysilicon is formed by plasma CVD.

Next, as shown in FIG. 36C, the polysilicon 145 on the cathode electrode 112 is made porous to form nanosilicon microcrystalline 147. As shown in FIG. Specifically, the substrate is immersed in a mixed solution of fluoric acid and ethyl alcohol, the substrate is used as the positive electrode, and Pt as the opposite electrode is made the negative electrode, and a voltage is applied therebetween. Silicon microcrystals are formed.

Subsequently, the substrate 143 is washed and then immersed in a sulfuric acid solution. When the substrate is applied with a positive electrode and Pt as a negative electrode, the surfaces of the polysilicon 145 and the silicon microcrystal are oxidized together. Finally, as shown in FIG. 36D, the metal thin-film electrode 141, such as Au alloy and Ag alloy, is sputtered and provided, and the electron emission body 119 can be obtained by patterning by photo etching. As described above, the method for producing an electron emitter in the present embodiment is relatively low in number of steps, and can be produced using a wet process.

Next, as in the eleventh embodiment described above, the phosphor particle powder was placed on a ceramic plate made of inorganic fibers (a ceramic fiber plate having a thickness of about 1 mm and a porosity of about 45% in an A1 ₂ O ₃ -CaO-SiO ₂ system). Was prepared, and Ag electrode paste was etched to a thickness of 30 mu m on both surfaces thereof to form a first electrode 6 and a second electrode 7. As shown in FIG. The ceramic fiber board thus obtained is attached to the electron emitter 119 using colloidal silica, water glass or epoxy resin as shown in FIG.

In the above-described step, the light emitting element 1 of FIG. 35 in the present embodiment in which the porous defoamer 2 is disposed on the electron emitter 119 and the electrode is provided at a predetermined position is provided. You can get it.

Next, the light emission effect of this light emitting element 1 is demonstrated. In order to drive the light emitting element 1, first, a 15-20V DC electric field is applied between the metal thin film electrode 141 and the cathode electrode 112 of FIG. 35, whereby electrons tunnel the silicon microcrystals from the cathode electrode. Then, it is accelerated by the oxide film on the surface and is released into the porous light emitting body.

As described above, electrons are emitted and an alternating electric field is applied between the first electrode 6 and the second electrode 7. The electrons emitted in accordance with the movement of the charge multiply exponentially to generate creeping discharges inside the porous light-emitting body 2. Creeping discharges are continuously generated in a chain, charge transfer occurs around the phosphor particles, and accelerated electrons collide with the light emission center, and the porous light emitting body 2 is excited to emit light. Ultraviolet rays and visible light are also generated at this time, and excitation light is emitted even by ultraviolet rays.

Further, by changing the waveform of the alternating electric field to be applied from a sine wave or a sawtooth wave to a rectangular wave and raising the frequency from several hundred Hz to several thousand Hz, electron emission and creepage discharge occur more violently, and as a result, the emission luminance is improved.

Once the creeping discharge is started, as described above, the discharge is repeated in series and generates ultraviolet rays and visible light constantly. Therefore, it is necessary to suppress the deterioration of the phosphor particles 3 due to the light rays. It is preferable to reduce this.

In this embodiment, an alternating electric field of about 0.5 to 1.0 kV / mm is applied to the thickness of the porous light emitting body 2 using an alternating current power source, thereby causing charge transfer and creeping discharge, and then light emission is started. At this time, the larger the electric field to which a voltage is applied promotes the generation of electrons. If too small, the generation of electrons is insufficient.

In addition, it was confirmed that the current value at the time of discharge was 0.1 mA or less, and light emission continued when the light emission started, even if the voltage was reduced to 50 to 80% at the time of application.

In this embodiment, although driving was performed in air | atmosphere, it confirmed that light emission was carried out similarly even if it implemented in oxygen, nitrogen, an inert gas, or in reduced pressure gas.

In addition, although blue fluorescent substance particle was used in this embodiment, it turned out that the same result is obtained even if it uses red or green. Moreover, the same result was obtained also in blue, red, and green mixed particle.

According to the light emitting device of the present embodiment, since the light emission is caused by the surface discharge, the thin film formation process is hardly used for forming the phosphor layer as in the prior art, and since the vacuum system or the carrier multiplication layer are not required, the structure is simple and the processing degree It is easy.

(Embodiment 20)

With reference to FIG. 37A-C, the electron emission body which comprises a part of light emitting element in this embodiment is demonstrated. The electron emitter in the present embodiment uses a whisker emitter instead of the carbon nanotubes described above.

37A-C are diagrams for explaining a method for manufacturing a hypolipidemic emitter according to the present embodiment, where 112 is a cathode electrode, 113 is a gate electrode, 116 is an insulating layer, 117 is a substrate, 155 is an organometallic complex gas, 157 is a whisker emitter. As shown in FIG. 37A, Au is deposited on the surface of the glass substrate 117 to form the cathode electrode 112, and the insulating layer 1 16 and the gate electrode 113 are placed on the insulating layer 116. The formation method is performed in the same manner as in the nineteenth embodiment described above. Next, as shown in FIG. 37B, a whisker emitter is formed by the CVD method. Specifically, a large amount of Al: Zn organometallic complex gas 155 is showered toward the cathode electrode. At this time, when the amount of gas exceeds a certain amount, the thermally oxidized Al: ZnO film grows in the vertical direction. Increasing the source gas also sharpens the tip of the film and sharpens the tip to a few nm level. For this reason, the Al: ZnO whisker is self-aligned with patterning and vertical alignment. By depositing, paying attention to the input amount of the source gas, the deposition temperature, and the deposition time, an electron emitter having an Al: ZnO whisker emitter 157 is obtained as shown in FIG. 37C.

Subsequently, phosphor particles were placed on a ceramic plate made of inorganic fibers (a ceramic fiber plate having a thickness of about 1 mm and having a porosity of about 45% in an A1 ₂ O ₃ -CaO-SiO ₂ system) in the same manner as in Embodiment 11 described above. A light emitting element (not shown) can be obtained by manufacturing the porous light-emitting body which carries the powder, and providing a predetermined electrode and laminating it on the above-mentioned electron emitter.

Next, the light emission effect of this light emitting element 1 is demonstrated. In order to drive the light emitting element, first, a direct current of 850 and 80 V is applied between the anode electrode and the cathode electrode, and between the gate electrode and the cathode electrode, thereby emitting electrons from the whisker emitter.

As described above, electrons are emitted and an alternating electric field is applied between the first electrode and the second electrode. The electrons emitted in accordance with the movement of the charge multiply exponentially to generate creeping discharges inside the porous light emitter. Creeping discharges are continuously generated in a chain, charge transfer occurs around the phosphor particles, and accelerated electrons collide with the emission center to excite and emit light. At this time, ultraviolet rays and visible rays are also generated, and excitation light is emitted also by ultraviolet rays.

Further, by changing the waveform of the alternating electric field to be applied from a sine wave or a sawtooth wave to a rectangular wave and raising the frequency from several hundred Hz to several thousand Hz, electron emission and creepage discharge occur more violently, and as a result, emission luminance is improved.

Once the creeping discharge is started, as described above, the discharge is repeated in series and generates ultraviolet rays and visible light constantly. Therefore, it is necessary to suppress the deterioration of the phosphor particles 3 due to the light rays. It is preferable to reduce this.

Specifically, by applying an alternating electric field of about 0.5 to 1.0 kV / mm to the thickness of the porous light emitting body by using an alternating current power source, charge transfer and creeping discharge occurred, and then light emission was started. In addition, the larger the electric field applied at this time promotes the generation of electrons, but when too small, the emission of electrons becomes insufficient. In addition, it was confirmed that the current value at the time of discharge was 0.1 mA or less, and light emission continued when the light emission started, even if the voltage was reduced to 50 to 80% at the time of application.

In this embodiment, although driving was performed in air | atmosphere, it confirmed that light emission was carried out similarly even if it implemented in oxygen, nitrogen, an inert gas, or in reduced pressure gas.

In addition, although blue fluorescent substance particle was used in this embodiment, it turned out that the same result is obtained even if it uses red or green. Moreover, the same result was obtained also in blue, red, and green mixed particle.

According to the light emitting element of this embodiment, since it is light emission by creeping discharge, since the thin film formation process is hardly used for conventional phosphor layer formation and a vacuum system or a carrier multiplication layer are not needed, a structure is simple and it is easy to process. Do.

In addition, in the above-mentioned electron emitter, it is also possible to use silicon carbide or a diamond thin film instead of the whisker emitter, and also in these materials, by applying a gate voltage between the cathode and the gate electrode, It is also possible to emit electrons and irradiate the porous light emitter.

(Embodiment 21)

In the present embodiment, with reference to FIGS. 38 to 40, in the light emitting device including the electron emitter, the porous light emitter and the pair of electrodes, a pair of electrodes provided for applying an electric field to the porous light emitter in particular will be described. do.

38 to 40 are cross-sectional views of the porous light-emitting body constituting a part of the light emitting element, 2 is a porous light emitter, 3 is a phosphor particle, 4 is an insulating layer, 6 is a first electrode, and 7 is a second electrode. As the porous light emitter shown in Fig. 38, similarly to the sixteenth embodiment described above, blue phosphor particles 3 were used, and an insulating layer 4 made of an insulating inorganic material made of MgO was used on the surface thereof. Specifically, the phosphor particles are added to the Mg precursor complex solution, stirred for a long time, extracted, dried, and thermally treated at 400 to 600 ° C. in the air, thereby providing a uniform coating layer of MgO, that is, an insulating layer on the surface of the phosphor particles. It is formed. 50 mass% of the fluorescent substance particles 3 coated with the insulator layer 4 mentioned above, and 50 mass% of aqueous colloidal silica solution are mixed and slurried.

Next, a ceramic plate made of inorganic fibers (a ceramic fiber plate having a thickness of about 1 mm and a porosity of about 45% in an Al ₂ O ₃ -CaO-SiO ₂ system) was immersed in the slurry and heated to a temperature of 120 to 150 ° C. By drying for 30 minutes, the phosphor particle powder is supported on a ceramic plate. After this, as shown in FIG. 38, the Ag electrode paste was etched to 30 micrometers in thickness on the upper surface, and the 1st electrode 6 and the 2nd electrode 7 were formed. The light emitting element (not shown) of this invention is obtained by attaching the ceramic fiber board obtained in this way to an electron emitting body using colloidal silica, water glass, or an epoxy resin.

In the first embodiment described above, as shown in FIG. 38, the first electrode 6 and the second electrode 7 are formed to face the upper surface and the lower surface of the porous light-emitting body. As described above, the upper and lower sides may be formed obliquely intersecting.

Next, as shown in FIG. 40, the case where both the 1st electrode 6 and the 2nd electrode 7 are embedded in the porous light-emitting body 2 is formed. The phosphor particles 3 coated with an insulating layer 4 made of MgO were mixed with 5% by mass of polyvinyl alcohol to prepare particles, and then molded into a plate shape at a pressure of about 50 MPa using a molding die. Next, heat treatment was performed at 450 to 1200 ° C. for 2 to 5 hours in a nitrogen atmosphere to produce a plate-like porous light-emitting body 2. When the apparent porosity of the porous light-emitting body is less than 10%, creeping discharges are generated only on the surface of the light-emitting body and the luminous efficiency is lowered. For this reason, the porous light-emitting body which has a porous structure whose external porosity is 10% or more is preferable. In addition, if the porosity of the light-emitting body is too large and the porosity is excessive, it is expected that the luminous efficiency is lowered or the surface discharge hardly occurs. Ideally, the apparent porosity is preferably 10% or more and less than 100%.

Ag electrode paste was etched to 30 micrometers in thickness on the surface of the plate-shaped porous light-emitting body 2 obtained as mentioned above, and the 1st electrode 6 and the 2nd electrode 7 were formed. After this, a slurry obtained by mixing 50% by mass of the phosphor particles 3 coated with the above-described insulating layer 4 and 50% by mass of a colloidal silica water solution was applied to the surface of the porous light-emitting body on which the electrode was formed. It dries for 10 to 30 minutes at the temperature of 120-150 degreeC. By doing in this way, the porous light-emitting body in which the 1st electrode 6 and the 2nd electrode 7 were embedded together can be obtained as shown in FIG.

In addition, the method of forming the insulating layer of MgO on the surface of fluorescent substance particle may be performed as follows. First, a solution composed of CH ₃ COOH (10 molar ratio), H ₂ O (50 molar ratio) and C ₂ H ₅ OH (50 molar ratio) was added to Mg (OC ₂ H ₅ ) ₂ powder (1 molar ratio), which is a metal alkoxide, at room temperature. The mixture is mixed well with stirring to prepare an almost transparent sol-gel solution. Phosphor particles (2 molar ratio) such as BaMgAl ₁₀ O ₁₇ : Eu ²⁺ (blue), Zn ₂ SiO ₄ : Mn ²⁺ (green), YBO ₃ : Eu ³⁺ (red) having an average particle diameter of 2 to 3 μm. Is added little by little while stirring in the above-mentioned sol-gel solution, and mixed. After continuing this operation for one day, the mixed solution was centrifuged, the powder was placed in a ceramic vat, and dried overnight at 150 ° C.

Next, by drying the powder after drying temporarily at 400-600 degreeC for 2 to 5 hours in air | atmosphere, the uniform insulating layer which consists of MgO was formed on the surface of fluorescent substance particle.

The thickness of the insulating layer was 0.1 to 2.0 µm as a result of observing the phosphor particles with a transmission electron microscope (TEM). As described above, the coating of the insulating layer may be performed by immersing the phosphor particles in a metal alkoxide solution, using a metal complex solution as described above, or by vapor deposition, sputtering, or CVD. .

In addition, the metal oxide used as an insulating layer is Y ₂ O ₃ , Li ₂ O, MgO, CaO, BaO, SrO, Al ₂ O ₃ , SiO ₂ , MgTiO ₃ , CaTiO ₃ , BaTiO ₃ , SrTiO ₃ , ZrO ₂ , TiO ₂ , B ₂ O _3, and the like are known, and it is preferable to form an insulating layer using at least one of these.

In particular, when the insulating layer is formed by the gas phase method, it is preferable to pretreat the phosphor particles in a nitrogen atmosphere at 200 to 500 ° C. for about 1 to 5 hours. Usually, the phosphor particles contain a large amount of adsorbed water or crystal water, and in this state, Formation of the insulating layer affects the life characteristics such as luminance deterioration and emission spectrum shift, which is undesirable.

In addition, the thickness of the insulating layer was about 0.1 to 2.0 µm, which is determined in consideration of the average particle diameter of the phosphor particles and the occurrence of creepage discharge, and when the average particle diameter is a sub-micron order, it is necessary to form a very thin coating layer. It is thought to be.

Increasing the thickness of the insulating layer is not preferable in terms of shift of the emission spectrum, decrease in luminance, and shielding of electrons. In addition, it is expected that as the insulating layer becomes thinner, the continuous generation of creepage discharges becomes slightly difficult. Therefore, the relationship between the average particle diameter of the phosphor particles and the thickness of the insulating layer is preferably in the range of 1/10 to 1/500 with respect to the former (1).

In addition, it is preferable that the phosphor particles are each coated with an insulating layer made of a metal oxide, but in reality, the phosphor particles of 2 and 3 are coated in an aggregated state. In this way, even when the phosphor particles are coated in a somewhat aggregated state, they hardly affect the appearance of light emission.

When the light emitting element of this invention was produced using the porous light emitting body obtained in this way, it was confirmed that the light emitting element of high brightness | luminance, high contrast, high recognition, and high reliability is obtained.

In addition, when manufacturing the fluorescent substance particle 3 which the surface was coat | covered with the insulating layer 4, in order to encourage generation | occurrence | production of creeping discharge, it is also possible to mix the insulating fiber 18 and to manufacture the porous light-emitting body 2. . Roneun insulating fibers 18 used at this time, the electrically insulating fibers, such as of SiO ₂ -Al ₂ O ₃ -CaO system is suitable. 41 is a schematic view of the cross section of the porous light-emitting body thus obtained. It is also possible to use a mixture of the phosphor particles 3 and the insulating fibers 18 as a simple method instead of heat treating the phosphor particles 3 coated with the insulating layer 4. FIG. 42 is a schematic view of a cross section of a porous light emitting body obtained from a mixture of phosphor particles 3 and insulating fibers 18. FIG.

(Embodiment 22)

The outline of the field emission display (FED) structure produced by combining the porous light-emitting body of the present invention described in the present embodiment and the electron-emitting body including the spin type emitter will be described with reference to the drawings.

FIG. 43 is an exploded perspective view of main parts of the field emission display in the present embodiment, and FIG. 44 is an alignment sectional view of the light emitting element using the spin type emitter in the present embodiment. In Fig. 43, 2 is a porous light emitter, 119 is an electron emitter, 170 is a field emission display, 171 is a gate line, 172 is a cathode line, 173 is an anode substrate, and 174 is a cathode substrate. In FIG. 44, 1 is a light emitting element, 2 is a porous light emitter, 3 is a phosphor particle, 4 is an insulating layer, 100 is a spin type emitter, 111 is an anode electrode, 112 is a cathode electrode, 113 is a gate electrode, and 116 is an insulator 117 is a substrate and 175 is a spacer.

As shown in FIG. 43, in the field emission display 170 of the present embodiment, an anode substrate 173 having a porous light emitter 2 on a cathode substrate 174 on which an electron emitter 119 is mounted. Are laminated so as to face each other. The cathode substrate 174 is provided with two layers of wirings, the gate line 171 and the cathode line 172 orthogonal to each other, and the electron emitter 119 is formed at the intersection thereof. By doing so, in the field emission display 170 of the present embodiment, two-dimensional images can be displayed on the fluorescent surface without deflecting the electron beam like CRT.

As described in the sixteenth embodiment, in the electron emitter 119 using the spin type emitter 100, the conical spin type emitter 100 and the extraction voltage of electrons formed to surround the same are applied. It is composed of a gate electrode 113 for.

When electrons are emitted from the emitter, a potential is applied to the gate and a negative potential to the emitter. Concentration of a strong electric field occurs at the tip of the conical emitter, from which electrons are emitted in the direction of the porous light-emitting body 2. In the Mo spin type emitter, electrons are emitted at a voltage of 15 to 80V. In addition, in an actual display panel, a plurality of emitters are formed in correspondence with one pixel, so that the operation state of the emitter can have high redundancy. By doing so, current fluctuations peculiar to this kind of element are also statistically averaged, so that stable pixel emission can be obtained. In addition, matrix driving is possible by so-called simple matrix driving, and one data line is simultaneously displayed by applying a negative data voltage to the emitter line 172 while applying a positive scan pulse to the gate line 171. Let's do it. By sequentially changing the scanning pulses, a two-dimensional image can be displayed. In addition, active driving is also possible by providing transistors in one of the pixels arranged in a matrix and turning each pixel ON and OFF.

As an example, a cross section of a light emitting element in which a plurality of spin type emitters 100 are formed and the porous light emitting bodies 2 are laminated so as to correspond to each emitter is shown in FIG. 44. At this time, in order to avoid crosstalk of light emission as shown, it is preferable to form the spacer 175 in the porous light-emitting body 2. In addition, in the field emission display according to the present embodiment, the use of the spin type emitter 100 as the electron emitter 119 has been described. However, the present invention is not limited thereto, and the present invention is not limited thereto. By combining with the porous light emitting material, it is possible to produce a field emission display.

(Embodiment 23)

45A-C are sectional views of the light emitting device according to the present embodiment, in which 1 is a light emitting device, 2 is a porous light emitting layer, 3 is a phosphor particle, 4 is an insulating layer, 5 is a substrate, and 6 is a first An electrode, 7 is a second electrode, 8 is a light transmissive substrate, 9 is a gas layer, 10 is a dielectric layer, and 11 is a partition wall.

The manufacturing method of the light emitting element of FIG. 45A is as follows. First, Ag paste is etched to a thickness of 30 µm on one surface of the sintered body of the dielectric 10 having a thickness of 0.3 to 1.0 mm to form a first electrode 6 having a predetermined shape. Next, the side on which the first electrode is formed is bonded to a glass or ceramic substrate 5. The dielectric can be used for use in any of those already described in Embodiment 1.

Next, in the same manner as in the first embodiment, the phosphor particles 3 coated with the surface of the insulating layer 4 made of metal oxide such as MgO are prepared. Examples of the phosphor particles 3 include BaMgAl ₁₀ O ₁₇ : Eu ²⁺ (blue), Zn ₂ SiO ₄ : Mn ²⁺ (green), YBO ₃ : Eu ³⁺ (red) and the like having an average particle diameter of 2 to 3 µm. It is possible to use an inorganic compound.

In the present embodiment, the phosphor particles 3 coated with the insulating layer 4 made of MgO are mixed with 5% by mass of polyvinyl alcohol to prepare powder, and then plated at a pressure of about 50 MPa using a molding die. Molded into shape. The molded article thus obtained was heat-treated at 450 to 1200 ° C. for 2 to 5 hours in a nitrogen atmosphere to prepare a plate-like porous light-emitting body 2.

When the apparent porosity of the porous light emitting body is less than 10%, when electrons collide with the porous light emitting layer, light is emitted from the surface of the porous light emitting layer, but electrons are not injected to the inside of the light emitting layer. . For this reason, it is preferable that the apparent porosity of the porous light-emitting body in the present embodiment has a porous structure of 10% or more so that electrons generated by the discharge can be smoothly injected into the porous light-emitting layer. In addition, when the apparent porosity of the porous light-emitting body becomes very large, light emission efficiency is lowered or creeping discharge is less likely to occur inside the porous light-emitting layer, so the apparent porosity is in the range of 10% or more and less than 100%. In particular, the range of 50 to less than 100% is preferable.

The plate-shaped porous light-emitting body 2 obtained as described above is attached to the dielectric layer 10 using a glass paste. At this time, the glass paste is screen printed at the positions of both ends of the porous light emitting layer, and the porous light emitting layer is adhered thereto. Subsequently, when the heat treatment is performed at 580 ° C., the porous light emitting layer can be adhered to the dielectric layer 10 with the gas layer interposed therebetween.

Next, when the second electrode 7 made of ITO (indium-tin oxide alloy) is covered with a light emitting substrate 8 such as a glass plate formed in advance so as to face the porous light emitting layer, the porous light emitting layer 8 is shown in Fig. 45A. The light emitting element 1 is obtained. At this time, the light-transmissive substrate 8 is heat-treated using glass paste, colloidal silica, water glass, resin, or the like so that a minute gap in which gas exists between the porous light emitting layer 2 and the second electrode 7 is formed. Attach by. Thereby, as shown in FIG. 45A, in the state in which a gas layer exists above and below a porous light-emitting body layer, the both ends of a porous light-emitting layer adhere | attach with the glass paste etc. which function as the partition 11. As shown in FIG.

The gas layer, which is interposed between the porous light emitting layer 2 and the dielectric layer 10, on the upper and lower sides of the porous light emitting layer which is the feature of the present embodiment, As for the thickness of the gas layer interposed between all, the range of 20-250 micrometers is suitable, and 30-220 micrometers is the most preferable range especially. If it is larger than the above range, it is necessary to apply a high voltage to the generation of the discharge, which is not preferable for economic reasons. In addition, the thickness of the base layer is not a problem in the above range, and there is no problem if the base layer is more than the average free stroke of the base. However, when the base layer is very thin, it becomes slightly difficult to control the thickness in the manufacturing process of the light emitting device.

In addition, the thickness of the gas layer which exists above and below the porous light-emitting body layer in this embodiment does not necessarily need to be the same. However, in the case where the gas layers are provided at two upper and lower positions of the light emitting layer, the thickness of each gas layer is preferably set to be slightly narrower as compared with the case where there is a gas layer at only one position of the light emitting layer as shown in FIG. Do. If the thickness of the base layer becomes large, it is necessary to apply a relatively high voltage in the discharge, which is not preferable in terms of economy.

As described above, the present embodiment is characterized in that a gas layer is formed above and below the porous light emitting layer. When an alternating electric field is applied to the first electrode and the second electrode, which are a pair of electrodes, discharge is performed simultaneously in the upper and lower gas layers. As a result, electrons are emitted from above and below the porous light emitting layer and efficiently injected into the light emitting layer. That is, when the alternating electric field to be applied is gradually increased and a voltage above the dielectric breakdown voltage is applied to the base layer, discharge occurs, and electrons multiply in the base layer, and electrons collide with the porous emitter so that the emission center of the porous emitter layer is electron. Is excited and emits light. In this way, the gas layer serves as an electron source, and the generated electrons are injected from above and below the porous light emitting layer, and pass through the inside of the layer while generating creeping discharge in the entire light emitting layer. Creeping discharge is generated continuously while an electric field is applied. At this time, the generated electrons collide with the emission center of the phosphor, and the phosphor particles 3 are excited to emit light. As a result of efficiently injecting electrons from above and below the porous light emitting layer, as described in Embodiment 1, compared with the case where electrons are injected from one side of the light emitting layer, the porous structure according to the present embodiment has a structure. In the light emitting layer, the entire layer emits light uniformly and efficiently, resulting in a very high luminance.

As described above, in the present embodiment, particularly in the light emitting element having a base layer and a porous light emitting layer in contact with the base layer and at least a pair of electrodes for applying an electric field to the base layer and the porous light emitting layer, particularly porous The pair of first electrodes in the pair of electrodes for applying the dielectric layer and the electric field are disposed on one side of the light emitting layer, and the pair of the dielectric layers and the first electrode of the porous light emitting layer are not disposed. The light emitting element in which the 2nd electrode in the electrode of this is arrange | positioned through the base layer can be manufactured.

In the present embodiment, as shown in FIG. 45B, the porous light emitting layer 2 is not formed between the porous light emitting layers 2 and 2 and the dielectric layer 10 without forming a gap formed of the base layer 9. And 2) and the gaps composed of the gas layers 9 and 9, respectively, may be formed between the electrodes 6 and 7.

In this way, the porous light emitting layers 2 and 2 can emit light by applying an electric field from the pair of electrodes 6 and 7 to the gas layers 9 and 9 and the porous light emitting layers 2 and 2 in contact therewith. have.

In this embodiment, what should be paid special attention in the heat processing process of forming a porous light-emitting body layer is heat processing temperature and atmosphere. In this embodiment, since heat treatment was performed at a temperature range of 450 to 1200 ° C. in a nitrogen atmosphere, there was no change in the valence of the rare earth atoms doped with the phosphor. However, when treating at a temperature higher than this temperature range, care should be taken because the valence of rare earth atoms may change or a solid solution composed of an insulating layer and a phosphor may be generated. As for the heat treatment atmosphere, a nitrogen atmosphere is preferable in order not to affect the valence of the rare earth atoms doped in the phosphor particles as described above.

Although the thickness of the insulating layer was about 0.1-2.0 micrometers in this embodiment, it determines in consideration of generating the average particle diameter of a fluorescent substance particle | grain, and surface discharge efficiently. In addition, when the average particle diameter of fluorescent substance becomes a submicron order, it is better to coat relatively thinly. If the insulating layer is thick, it is not preferable because the emission spectrum shifts, the luminance decreases, or the like. On the contrary, when the insulating layer is thin, it is assumed that the surface discharge is less likely to occur. Therefore, the relationship between the average particle diameter of the phosphor particles and the thickness of the insulating layer is preferably in the range of 1/10 to 1/500 for the former 1.

Next, the light emission effect of this light emitting element 1 is demonstrated.

As shown in the figure, in order to drive the light emitting element 1, an alternating electric field is applied between the first electrode 6 and the second electrode 7. When the alternating electric field to be applied is gradually increased and a voltage higher than the dielectric breakdown voltage is applied to the gas layer, discharge occurs, and electrons multiply in the gas layer, which impinges on the porous light emitter, and the emission center of the light emitting layer is excited in the electron. It emits light. As described above, the gas layer acts as an electron source, and the electrons generated in the present embodiment are injected from above and below the porous light emitting layer, so as to flood the inside of the light emitting layer while generating creeping discharges in the entire light emitting layer made of porous material. To pass. Creeping discharges continue to occur while an electric field is applied, at which time the generated electrons collide with the emission center of the phosphor, and the phosphor particles 3 are excited to emit light. As described above, in the present embodiment, as the electrons are injected from above and below the porous light emitting layer, the porous light emitting layer is compared with the case where only electrons are injected from one side of the light emitting layer as in the light emitting device described in the first embodiment. The whole layer emits light uniformly and efficiently efficiently, and the brightness becomes remarkably large.

In the present embodiment, since a porous light emitting body having an apparent porosity of 10% or more and less than 100% is used, the light emitting layer emits light on the surface of the ordinary light emitting layer having no porous structure, but hardly emits light inside the layer. In the light-emitting body layer made of porous in the present embodiment, light emission efficiency becomes very good because light is emitted not only on the surface of the layer but also inside the light-emitting layer. As described above, in the case of the porous layer, electrons generated by the discharge due to the porous structure are smoothly injected into the inside of the layer, and creeping discharge occurs in the entire layer to emit light, and as a result, light emission with high luminance can be obtained.

Moreover, it is preferable that the porous light emitting body used by this embodiment has a porous structure whose external porosity is 10% or more. In addition, when the apparent porosity of the light emitter becomes very large, the apparent apparent porosity is in the range of 10% to less than 100%, on the contrary, because the luminous efficiency is lowered or creeping discharge is less likely to occur inside the porous light emitting layer. In particular, less than 50-100% is the most preferable.

Further, by changing the waveform of the alternating current electric field to be applied from a sine wave or a sawtooth wave to a rectangular wave, and raising the frequency from tens of Hz to several thousand Hz, the emission of electrons due to the surface discharge becomes extremely intense, and the luminescence brightness is improved. In addition, a burst wave is generated as the voltage of the alternating electric field increases. The generation frequency of the burst wave is generated just before the peak in the sine wave and at the peak in the sawtooth wave or the rectangular wave, and the emission luminance is improved by raising the voltage of the burst wave. Once the creeping discharge is started, ultraviolet rays and visible light are also generated, so it is necessary to suppress deterioration of the phosphor particles 3 due to these light rays, and it is preferable to reduce the voltage after the start of light emission.

45A and 45B in the present embodiment, the phosphor particles 3 are made to emit light by applying an electric field of about 0.79 to 1.7 and 0.75 to 1.6 kV / mm, respectively, to the thickness of the porous light emitting layer, Thereafter, alternating electric fields of about 0.55 to 1.1 and 0.52 to 1.0 kV / mm were applied, so that creeping discharge was continued, and light emission of the phosphor particles 3 was continued. If the electric field to be applied is large, the generation of electrons is promoted, but if it is small, these generations are suppressed. When the gas present in the base layer is air, it is necessary to apply at least a voltage of about 0.3 kV / mm, which is the dielectric breakdown voltage.

In addition, the current value at the time of discharge is 0.1 mA or less, and when light emission starts, light emission will continue even if voltage is reduced to about 50 to 80% at the time of application, and high luminance, high contrast, also in light emission of all three fluorescent substance particles, It was confirmed that it was high recognition, high reliability light emission. In this embodiment, although driving was performed in air | atmosphere, it confirmed that light emission was carried out similarly even if it carried out in rare gas, gas which became the state of pressurized or underpressure.

According to the light emitting device of the present embodiment, since the porous light emitting layer is formed by a thick film process or the like, a vacuum system or a carrier multiplying layer are not required in the production of the light emitting device as in the prior art without using a thin film forming process. The structure is simple and manufacturing and processing are easy. In addition, since the electrons generated by the discharge collide with the light emitting layer on both sides of the porous light emitting layer, and the light emitting structure is porous, the collided electrons are smoothly injected while generating creeping discharge to the inside of the light emitting layer. It is possible to obtain. A light emitting body which is not porous in general emits light only on its surface, whereas the whole light emitting layer emits light as described above in the porous light emitting layer of the present embodiment, which is characterized by high luminance. In addition, the luminous efficiency is very good as compared with the light emission of the phosphor by ultraviolet rays performed in the plasma display. In addition, it is possible to provide a light emitting device having a relatively low power consumption when used in a large display. By providing partition walls as discharge separation means at both ends of the porous light emitting layer, it is possible to easily avoid crosstalk of light emission.

Next, FIG. 45C is the same except that the dielectric layer 10 interposed between the porous light emitting layer 2 and the first electrode 6 is not formed in the light emitting device of FIGS. 45A-B.

The manufacturing method of the light emitting element of FIG. 45C is as follows. First, Ag paste is etched to a thickness of 30 µm on one surface of a substrate 5 made of glass or ceramic, and the first electrode 6 is formed in a predetermined shape.

Next, in the same manner as in the first embodiment, the phosphor particles 3 coated with the surface of the insulating layer 4 made of metal oxide such as MgO are prepared. Examples of the phosphor particles 3 include BaMgAl ₁₀ O ₁₇ : Eu ²⁺ (blue), Zn ₂ SiO ₄ : Mn ²⁺ (green), YBO ₃ : Eu ³⁺ (red) and the like having an average particle diameter of 2 to 3 µm. It is possible to use an inorganic compound.

In the present embodiment, similarly to the third embodiment, after forming the particles by mixing the phosphor particles 3 coated with the insulating layer 4 made of MgO with 5% by mass of polyvinyl alcohol, the molding die is prepared. The plate was molded into a plate at a pressure of about 50 MPa. The molded article thus obtained was heat-treated at 450 to 1200 ° C. for 2 to 5 hours in a nitrogen atmosphere to produce a plate-like porous light-emitting body 2.

Both ends of the plate-shaped porous light-emitting body 2 obtained as described above are attached to the electrode side of the substrate 5 using a glass paste. Specifically, as shown in FIG. 45C, when the glass paste is screen printed, the porous light emitting layer is bonded, and the heat treatment is performed at 580 ° C., the porous light emitting layer 2 is finely interposed between the first electrode and the first electrode. It adheres in the state which formed the clearance gap which consists of a gas layer. The thickness of the base layer existing between the porous light emitting layer 2 and the first electrode 6 is preferably in the range of 20 to 250 µm, particularly preferably in the range of 30 to 220 µm. If it exceeds the said range, it is necessary to apply a high voltage to generation | occurrence | production of discharge, and it is unpreferable for the reason of economic efficiency. In addition, even if it is thin in the said range, a gas layer is good and it should just exceed the average free stroke of a gas.

Next, when the second electrode 7 made of ITO (indium-tin oxide alloy) is covered with a light-transmissive substrate 8 such as a glass plate formed in advance so as to face the porous light-emitting layer, the porous light-emitting layer is shown in Fig. 45C. The light emitting element 1 in the present embodiment can be obtained. At this time, the light-transmissive substrate 8 is attached by heat treatment using a colloidal silica, water glass, resin, or the like so that a minute gap formed of a gas layer is formed between the porous light emitting layer 2 and the second electrode 7. . The thickness of the gap between the porous light emitting layer 2 and the second electrode 7 is not necessarily the same as the thickness of the gap between the porous light emitting layer and the first electrode described above, but may be set to almost the same thickness.

As described above, the present embodiment is characterized in that a minute gap is formed between the first electrode and the second electrode provided on both surfaces of the porous light emitting layer, and thus, between the porous light emitting layer and the pair of electrodes. Is interposed with a gas layer composed of a rare gas, air, oxygen, nitrogen, or a mixture of these gases. When an alternating electric field is applied to a pair of electrodes of such a light emitting device, discharge occurs when a voltage equal to or higher than the dielectric breakdown voltage is applied to the base layer. At this time, electrons multiply in the base layer, and electrons collide with the porous light emitter to The emission center is excited with electrons to emit light. In this way, the gas layer acts as an electron source, and the generated electrons impinge on the light emitting layer, are injected into the inside of the layer, and pass through as they rush while generating creeping discharges throughout the light emitting layer. Creeping discharges are generated continuously while an electric field is applied, and the generated electrons collide with the emission center of the phosphor, and the phosphor particles 3 are excited to emit light. As described above, in the present embodiment, electrons are supplied from both sides of the porous light emitting layer and smoothly injected into the inside of the light emitting layer. As a result, electrons are injected from one side of the porous light emitting body as in the first embodiment. As for the light emitting layer, the whole layer emits light uniformly and efficiently, and the brightness of light emission becomes high.

In addition, in this embodiment, what covered the surface of the fluorescent substance particle 3 with the insulating layer 4 which consists of MgO was used, MgO has high resistivity (10 ⁹ ohm * cm or more), and creeping discharge is efficiently carried out. Because it can be generated. If the resistivity of the insulating layer is low, creeping discharges are less likely to occur, and there is a possibility of a short circuit, which is not preferable. For this reason, it is preferable to coat | cover with insulating metal oxide with high resistivity. Of course, when the resistivity of the phosphor particles used itself is high, creeping discharge occurs easily without covering with an insulating metal oxide. As the insulating layer, at least one selected from Y ₂ O ₃ , Li ₂ O, CaO, BaO, SrO, Al ₂ O ₃ , SiO ₂ , and ZrO ₂ can be used as the insulating layer. The standard production free energy ΔG _f ⁰ of these oxides is very small (eg, below -100 kca 1 / mo 1 at room temperature) and is a stable material. Moreover, since these insulating layers have high resistivity and are hard to be reduced, they are also excellent as a protective film for suppressing reduction or degradation of phosphor particles by electrons, and as a result, durability of the phosphor is also high, which is preferable.

In addition, the formation of the insulating layer may be performed by a physical adsorption method using a chemical adsorption method, a CVD method, a sputtering method, a vapor deposition method, a laser method, a shear stress method, or the like in addition to the sol-gel method described above. It is preferable that the insulating layer is homogeneous, uniform and not peeled off. When forming the insulating layer, it is important to immerse the particles of the phosphor in a weak acid solution such as acetic acid, oxalic acid, citric acid, and to clean the impurities adhering to the surface.

Moreover, it is preferable to pretreat the particle | grains of fluorescent substance in nitrogen atmosphere for 200 to 500 degreeC for 1 to 5 hours before forming an insulating layer. This is because ordinary phosphor particles contain a large amount of adsorbed water or crystal water, and forming an insulating layer in such a state undesirably affects lifetime characteristics such as luminance decrease and emission spectrum shift. When the particle | grains of fluorescent substance are wash | cleaned with a weakly acidic solution, after wash | cleaning well, said pretreatment is performed.

Next, the light emitting action of the light emitting element 1 will be described with reference to Fig. 45C. As shown in the figure, in order to drive the light emitting element 1, an alternating electric field is applied between the first electrode 6 and the second electrode 7. At this time, the light emitting element was inserted into the quartz tube and enclosed in a state where the mixed gas of Ne and Xe was slightly pressurized. When the alternating electric field to be applied is gradually increased and a voltage above the dielectric breakdown voltage is applied to the gas layer, discharge occurs, and electrons multiply in the gas layer, which impinges on the porous light emitter and excites the emission center of the porous light emitter layer to electrons. Light emission. In this way, the gas layer acts as an electron source, and the generated electrons are injected into the inside of the layer from both sides of the porous light emitting layer, and pass through the light emitting layer while causing creeping discharge in the entire porous light emitting layer. Creeping discharge is generated continuously while an electric field is applied. At this time, the generated electrons collide with the emission center of the phosphor, and the phosphor particles 3 are excited to emit light. In the present embodiment, as a result of electrons being injected from both the upper and lower portions of the porous light emitting layer, as described in the first embodiment, as compared with the case where electrons are injected from one side of the porous light emitting layer, the entire layer of the porous light emitting layer is tight. It emits light uniformly and efficiently, and the brightness becomes remarkably high.

In addition, in this embodiment, since a porous light emitting body having an apparent porosity of 10% or more and less than 100% is used, the light emitting material emits light on the surface of the ordinary phosphor layer, which is not a porous light emitting material, but is hardly emitted inside the layer. In the light emitting layer, not only the surface of the layer but also light is emitted inside the layer, so that the light emitting efficiency is very good. This is because in the case of the porous light emitting layer, electrons enter the inside of the layer by discharge, and as a result, creeping discharge occurs in the whole layer, and light emission with high luminance can be obtained.

Further, by changing the waveform of the alternating current electric field to be applied from a sine wave or a sawtooth wave to a rectangular wave and raising the frequency from several tens of Hz to several thousand Hz, the emission of electrons due to the surface discharge is extremely intense, and the luminescence brightness is improved. In addition, a burst wave is generated as the voltage of the alternating electric field rises. The frequency of the burst wave is generated just before the peak in the sine wave and at the peak in the sawtooth wave or the rectangular wave, and the emission luminance is improved by raising the voltage of the burst wave. Once creeping discharge is started, ultraviolet rays and visible rays are also generated, so it is necessary to suppress deterioration of the phosphor particles 3 due to these rays, and it is preferable to reduce the voltage after the start of emission.

In the present embodiment, the phosphor particles 3 are made to emit light by applying an electric field of about 0.57 to 1.2 kV / mm in the same manner as the light emitting device of Embodiment 2 to the thickness of the porous light emitting layer, and then about 0.39 to 0.78 By applying an alternating electric field of kV / mm, surface discharge was continued, and light emission of the fluorescent substance particle 3 was continued. In the same manner as in the second embodiment, the light emission was emitted even when the voltage was reduced to about 60 to 80% as compared with the case where no rare gas was enclosed. The reason for this is that by enclosing the rare gas, the discharge is more likely to be generated, and the pressurization can significantly increase the luminance.

In addition, the current value at the time of discharge is 0.1 mA or less, and when light emission starts, light emission will continue even if voltage is reduced about 50 to 80% at the time of application, and light emission of Embodiment 2 also in light emission of any three fluorescent substance particles Compared with the device, it was confirmed that the light emitted was high luminance, high contrast, high recognition, and high reliability.

In this connection, when the light emitting device having no dielectric layer in the present embodiment emits light in the air, it is about 0.89 to 1.9 kV / mm in driving compared with the case where the rare gas is sealed in the pressurized state. By applying an alternating electric field to emit the phosphor particles 3, and then applying an alternating electric field of about 0.62 to 1.3 kV / mm, it was necessary to continue the creeping discharge to sustain the emission of the phosphor particles 3. .

According to the light emitting device of the present embodiment, since the porous light emitting layer is formed by a thick film process or the like, a vacuum system or a carrier multiplication layer are not required in the production of the light emitting device as in the prior art without using a thin film forming process. Therefore, the structure is simple, and manufacturing and processing are easy. In addition, since light emission is caused by creeping discharge based on electrons injected into the porous light emitting layer, light emission with high luminance is obtained, and not only the surface thereof emits light as in a normal phosphor, but the entire porous light emitting layer emits light. It is characterized by In addition, the luminous efficiency is very good as compared with the light emission of the phosphor by ultraviolet rays performed in the plasma display. In addition, it is possible to provide a light emitting device having relatively low power consumption when used as a large display. By providing partition walls as discharge separation means at both ends of the porous light emitting layer, it is possible to easily avoid crosstalk of light emission.

Since the light emitting device according to the present invention emits light by surface discharge, it is easy to manufacture since it does not use a thin film forming process for forming the phosphor layer as in the prior art and also does not require a vacuum container or a carrier multiplication layer. From this, the light emitting element of the present invention is also useful as a light emitting body constituting a unit pixel of a large screen display. Moreover, it is useful also as a light emitting body applied to illumination, a light source, etc.

Claims (41)

As a light emitting element comprising a light emitting layer comprising a phosphor and at least two electrodes, The light emitting device includes at least two kinds of electrical insulator layers having different dielectric constants, One of the electrical insulator layers is the light emitting layer, Any one of the two electrodes is formed in contact with any one of the insulator layer. The light emitting device according to claim 1, wherein the at least two electrodes are formed at an interface of an electrical insulator having a different dielectric constant. The light emitting device of claim 1, wherein the other one of the insulator layers is a gas layer, a ferroelectric layer, or a dielectric layer having a dielectric constant of 100 or more. The method of claim 3, wherein the ferroelectric layer or dielectric layer is formed of at least one layer selected from a sintered body layer, a mixed layer of particles and a binder comprising a ferroelectric material or a dielectric material and a molecular deposition thin film comprising a ferroelectric material or a dielectric material Light emitting device. The light emitting device according to claim 3, wherein the ferroelectric further has a rear electrode. The light emitting device of claim 1, wherein the phosphor is a porous light emitter. The light emitting device of claim 6, wherein the porous light emitter includes at least one gas selected from air, nitrogen, and an inert gas. The light emitting element according to claim 6, wherein the porous light emitting layer is composed of continuous fine holes connected to the surface of the porous light emitting layer, a gas filled in the fine holes, and phosphor particles. The light emitting device according to claim 6, wherein the porous light emitting body is formed of light emitting particles or light emitting particles coated with an insulating layer. The light emitting device according to claim 6, wherein an apparent porosity of the porous light emitting body is in a range of 10% or more and less than 100%. The light emitting device of claim 6, wherein the porous light emitter is formed of at least one particle selected from particles of a light emitter and light emitter particles coated with an insulating layer, and insulating fibers. The light emitting element according to claim 1, wherein the light emitting element is pressurized, atmospheric or reduced pressure, and the whole is sealed. The light emitting element according to claim 1, wherein the light emitting element emits a surface discharge by applying a direct current or an alternating electric field to at least two electrodes to emit light. The light emitting element according to claim 3, wherein the base layer is provided in a thickness of 1 µm or more and 300 µm or less. The light emitting element according to claim 1, wherein the light emitting layer is further divided into pixels for each pixel by discharge separation means. The light emitting element according to claim 15, wherein the discharge separating means is formed by a partition wall. The light emitting element according to claim 15, wherein the partition wall is formed of an inorganic material. The light emitting element according to claim 15, wherein the discharge separating means is formed by a void. The light emitting device according to claim 3, wherein the base layer is divided in the thickness direction by ribs. The light emitting device according to claim 1, wherein the light emitting layer separately emits at least red (R), green (G), or blue (B). The light emitting device according to claim 1, wherein the at least two electrodes are provided with the at least one dielectric layer and the light emitting layer interposed therebetween, by applying an alternating electric field to generate surface discharge to the light emitting layer, thereby emitting the light emitting layer. The light emitting device according to claim 1, wherein the at least two electrodes are address electrodes or display electrodes. The light emitting element according to claim 1, wherein the at least one electrode is a transparent electrode and is disposed on the viewing surface side. The light emitting element according to claim 3, wherein the base layer is formed between at least one of the light emitting layer and the transparent electrode on the viewing side, and between the light emitting layer and the back electrode. The light emitting device according to claim 1, wherein the light emitting layer is a porous light emitting layer, and the porous light emitting layer is disposed in contact with a ferroelectric layer. The light emitting device according to claim 25, wherein at least one of the electrodes is disposed in the porous light emitting layer so that an alternating electric field applied to the at least two electrodes is also applied to a portion of the porous light emitting layer. The light emitting device according to claim 25, wherein the at least two electrodes are formed with a ferroelectric layer and a porous light emitting layer interposed therebetween. The light emitting device according to claim 25, wherein both of the at least two electrodes are formed in the ferroelectric layer. The light emitting device according to claim 25, wherein both of the at least two electrodes are formed at a boundary between the ferroelectric layer and the porous light emitting layer. The light emitting device according to claim 25, wherein one of the at least two electrodes is formed at a boundary between the ferroelectric layer and the porous light emitting layer, and the other electrode is formed in the ferroelectric layer. The method of claim 1, wherein one of the electrically insulating layer is a ferroelectric layer, The at least two electrodes include a pair of electrodes and another electrode, The pair of electrodes are arranged such that an electric field is applied to at least a portion of the ferroelectric layer, The said other electrode is a light emitting element arrange | positioned so that an electric field may be applied to at least one part of the said light-emitting layer which exists between at least one of the said pair of electrodes. The light emitting device of claim 1, wherein the light emitting device emits light by applying a charge or electric field to a light emitting layer. The light emitting element according to claim 1, further comprising an electron emitter toward the light emitting layer, wherein the light emitting layer is disposed adjacent to the electron emitter so as to be irradiated by electrons generated from the electron emitter. The method according to claim 33, wherein the electron emitter comprises a cathode electrode, a gate electrode, and a Spindt Type emitter interposed between the two electrodes, the gate voltage between the cathode electrode and the gate electrode The light emitting device which emits light by irradiating the light emitting layer with electrons emitted from the spin type emitter. 35. The light emitting device of claim 34, wherein said spin type emitter is conical. 35. The light emitting device of claim 34, wherein the spin type emitter is composed of at least one metal selected from molybdenum, niobium, zirconium, nickel, and molybdenum steels. The carbon nanotube of claim 33, wherein the electron emitter comprises a cathode electrode, a gate electrode, and a carbon nanotube interposed between the two electrodes, and the gate electrode is applied between the cathode electrode and the gate electrode. A light emitting device for emitting light by emitting electrons emitted from the tube to the light emitting layer. 34. The light emitter according to claim 33, wherein the electron emitter is a surface conduction electron emission device, and a gap is formed in a metal oxide film and an electric field is applied to an electrode provided in the metal oxide film to irradiate a porous light emitter with electrons generated from the gap. A light emitting device for emitting a layer. 34. The light emitting device according to claim 33, wherein the electron emitter is made of a silicon microcrystal having an oxide film sandwiched by polysilicon having an oxide film, and emits light by irradiating electrons generated by applying a voltage to the silicon microcrystal having the oxide film on a light emitting layer. Light emitting device. The method of claim 33, wherein the electron emitter includes a cathode electrode, a gate electrode and a whisker emitter interposed between the two electrodes, and by applying a gate voltage between the cathode electrode and the gate electrode, A light emitting device for emitting light by irradiating the light emitting layer with electrons emitted from the whisker emitter. 34. The method of claim 33, wherein the electron emitter comprises a cathode electrode, a gate electrode, and a silicon carbide or diamond thin film interposed between the two electrodes, and by applying a gate voltage between the cathode electrode and the gate electrode. And a light emitting device emitting light by irradiating electrons emitted from the electron emitter onto a light emitting layer.

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