JP2006179436A - Light emitting element and display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting element and a display device that do not require a thin-film forming process, a vacuum system or a carrier multiplying layer, provide satisfactory light-emitting efficiency, and involve relatively low power consumption when used for producing a large-screen display. <P>SOLUTION: The light emitting element (1) includes a gas layer (100), a dielectric layer (10), a porous emitter layer (2), a pair of electrodes made up of an A electrode (6) and a B electrode (7), and a C electrode (17). The porous emitter layer (2) is disposed in contact with the dielectric layer (10), the gas layer (100) is disposed in contact with the porous emitter layer (2), the pair of electrodes made up of the A electrode (6) and the B electrode (7) are disposed such that an electric field is applied to at least part of the dielectric layer (10), and the C electrode (17) is disposed in contact with the dielectric layer (10) so that an electric field is applied to the dielectric layer (10). When a voltage between the A electrode (6) and the B electrode (7) reaches the breakdown voltage for the gas, primary electrons are generated and injected to the emitter layer, and this causes creeping discharge (electron avalanche) resulting in light emission. At this time, the intensity of light emission of the emitter layer is adjusted by applying a voltage to the C electrode. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a light emitting element and a light emitting element array. In particular, the present invention relates to a light-emitting element and a display device that are made of a porous light-emitting layer, have a simple configuration, are easy to manufacture, have low power consumption, and are suitable for large-sized displays.

  In recent years, liquid crystal displays and plasma displays have been widely used as large flat displays, but developments are being pursued in pursuit of displays with higher image quality and higher efficiency. Examples of such display candidates include an electroluminescence display (ELD) and a field emission display (FED). Non-Patent Document 1 describes ELD in general as follows. It is based on a structure in which an electric field is applied to a phosphor as a light emitting layer through an insulating layer, and an organic dispersion type and a thin film type are known. The organic dispersion type has a structure in which ZnS particles to which impurities such as Cu are added are dispersed in an organic material, an insulating layer is formed thereon, and sandwiched between upper and lower electrodes. The impurities form a pn junction in the phosphor particles, and when an electric field is applied, electrons emitted by a high electric field generated at the junction surface are accelerated, and then recombined with holes to emit light. The thin film type has a structure in which a phosphor thin film such as Mn-doped ZnS, which is a light-emitting layer, has electrodes arranged via an insulator layer. The presence of the insulator layer makes it possible to apply a high electric field to the light emitting layer, and emitted electrons accelerated by the electric field excite the light emission center to emit light.

  On the other hand, the FED has a structure comprising an electron-emitting device and a phosphor facing the electron-emitting device in a vacuum container, and accelerates electrons emitted into the vacuum by the electron-emitting device to irradiate the phosphor layer to emit light. It is.

In any device, electron emission is a trigger for light emission, so a technique for emitting electrons with low voltage and high efficiency is important. As such a technique, attention is focused on electron emission by polarization inversion of a dielectric. For example, in Non-Patent Document 2 below, as shown in FIG. 22, a PZT ceramic 31 having a planar electrode 32 installed on one surface and a grid electrode 33 installed on the other surface is contained in a vacuum vessel 36. It has been proposed that electrons are emitted by facing the platinum electrode 34 via the grid electrode 35 and applying a pulse voltage between the electrodes. Reference numeral 37 denotes an exhaust port. According to the proposal, the pressure in the container is 1.33 Pa (10 ⁻² Torr), and it is described that no discharge occurs at atmospheric pressure.

  A display using the light emission by accelerating the electrons emitted by the polarization reversal of the dielectric in the vacuum container and causing the phosphor layer to emit light, is also described in the following Patent Document 1 and Patent Document 2. However, instead of the platinum electrode disclosed in Non-Patent Document 2, the basic configuration is such that the phosphor layer emits light by a configuration having a phosphor layer.

  On the other hand, a light-emitting element using electrons emitted by polarization inversion of a ferroelectric substance in a non-vacuum is disclosed as an electroluminescent surface light source element in Patent Document 3 below, for example. As shown in FIG. 23, this element is formed on a substrate 45 in the order of a lower electrode 42, a ferroelectric thin film 41, an upper electrode 43, a carrier multiplication layer 48, a light emitting layer 44, and a transparent electrode 46. The upper electrode has an opening 47. By reversing 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 further accelerated by the positive voltage applied to the transparent electrode, while multiplying the electrons. It reaches the light emitting layer and emits light. It is described that the carrier multiplication layer is composed of a semiconductor having a relatively low relative dielectric constant and a band gap that does not absorb the emission wavelength emitted from the light emitting layer. This element can be considered as a kind of ELD. Further, Patent Document 4 discloses a configuration in which one of the insulators is made of a ferroelectric thin film in a configuration in which a light emitting layer made of a phosphor formed by sputtering is sandwiched between front and back insulating layers and a pulse electric field is applied. Has been.

Further, Patent Document 5 below discloses a color display device having a phosphor layer, and an X electrode 52 and a dielectric layer 53 are disposed on a glass substrate 51 as shown in a partially enlarged view of FIG. In addition, a Y electrode 55 is disposed on another glass substrate 56, and a phosphor layer 54 is entirely formed on the Y electrode 55, and then is covered with a dielectric layer 53 and in contact with the gas discharge space 59. It is what was made to face.
JP 05-216530 A US Pat. No. 5,453,661 Japanese Patent Laid-Open No. 06-283269 Japanese Patent Laid-Open No. 08-083686 JP 48-45169 A Edited by Shoichi Matsumoto, “Electronic Display”, Ohmsha, July 7, 1995, p. 113-125 Junichi Asano et al., 'Field-Exited Electron Emission from Ferroelectric Ceramic in Vacuum' Japanese Journal of Applied Physics Vol.31 Part 1 p.3098-3101, Sep / 1992

  The above-described prior art requiring a vacuum has a problem that the structure is complicated and expensive. For example, a plasma display can constitute a large panel, but it requires a vacuum vessel and a discharge space, so that the structure is complicated and expensive. In addition, it is difficult to increase the light emission efficiency of plasma displays because the discharge energy is once converted into ultraviolet energy, and the ultraviolet rays emit light by exciting the emission center of the phosphor. There is a problem of becoming larger. Moreover, since the thing using thin film EL uses a thin film formation process, there exists a problem that an installation becomes large-scale. Furthermore, it is difficult to produce a large-screen display, and a commercial product is not known.

  The present invention provides a light-emitting element and a display device that are made of a light-emitting body composed of a porous light-emitting body layer and can be easily manufactured. In addition, a light-emitting element and a display device that have high luminous efficiency, low power consumption, and are suitable for a large display by using a porous luminous body layer are provided. Furthermore, the light-emitting element of the present invention provides a light-emitting element and a display device with good light emission efficiency by applying an electric field to gas and irradiating the porous light-emitting layer with primary electrons generated by dielectric breakdown of the gas layer.

  The light emitting device of the present invention is a light emitting device including a gas layer, a dielectric layer, a porous light emitting layer, a pair of electrodes consisting of an A electrode and a B electrode, and a C electrode, wherein the porous light emitting layer is the dielectric layer. The gas layer is disposed in contact with the porous luminous body layer, and the pair of electrodes including the A electrode and the B electrode applies an electric field to at least a part of the dielectric layer. The C electrode is disposed in contact with the dielectric layer so that an electric field is applied to the dielectric layer.

  The display device of the present invention includes the light-emitting element, and a plurality of the light-emitting elements are arranged as light-emitting cells of one color or a plurality of colors, and a porous phosphor layer or a color filter layer having a color corresponding to each light-emitting cell. Is provided, and the porous phosphor layer includes a display panel that emits light on the surface.

  The light-emitting element of the present invention comprises a light-emitting body composed of a porous light-emitting body layer, and can provide a light-emitting element and a display device that can be easily manufactured. In addition, by using the porous light emitting layer, it is possible to provide a light emitting element and a display device that have high luminous efficiency, low power consumption, and suitable for a large display. Furthermore, the light-emitting element of the present invention can provide a light-emitting element and a display device with good light emission efficiency by applying an electric field to gas and irradiating the porous light-emitting layer with primary electrons generated by dielectric breakdown of the gas layer.

  In addition, a thin film formation process is not used for manufacturing a light emitting element as in the prior art, and since a vacuum system and a carrier multiplication layer are not required, the structure is simple, and manufacturing and processing are easy.

  In the light emitting device of the present invention, a voltage is applied between the A electrode and the B electrode. When the breakdown voltage of the gas is reached by the increase of the applied voltage, primary electrons and ultraviolet rays are generated in the gas layer. The electrons generated at this time are pulled in the direction of the porous light emitter layer due to the influence of the dielectric layer, and the electrons are injected into the porous light emitter layer. Therefore, creeping discharge (electron avalanche) occurs in the light emitting layer having a porous structure, and electron multiplication occurs. As a result, the luminescent center of the phosphor particles in the porous luminescent layer is excited to emit light. In addition, the light emission centers of the phosphor particles in the porous light emitting layer are excited by the ultraviolet rays generated in the gas layer to emit light.

  At that time, by applying a voltage to the C electrode provided in contact with the dielectric layer, the light emission level of the light emitting layer can be adjusted. That is, if 0 bias or + bias is applied to the C electrode, the density of electrons pulled in the direction of the porous light emitter layer is increased, and as a result, the degree of light emission is enhanced. Conversely, if a -bias is applied, the density of electrons pulled in the direction of the porous light emitter layer is lowered, and as a result, the degree of light emission is suppressed. As described above, in the present invention, by arranging the C electrode in contact with the dielectric, it is possible to adjust the light emission intensity of the porous light emitting layer and to display the gradation of the light emission luminance.

  Furthermore, the light-emitting element of the present invention can provide a light-emitting element array having a light-emitting efficiency and a light-emitting element that consumes relatively little power when a large display is used.

  The light emitting device of the present invention is a light emitting device including a gas layer, a dielectric layer, a porous light emitting layer, a pair of electrodes composed of an A electrode and a B electrode, and a C electrode, wherein the porous light emitting layer is the dielectric. The gas layer is disposed in contact with the porous light emitter layer gas layer, and the pair of electrodes including the A electrode and the B electrode are alternately disposed on at least a part of the dielectric layer. The C electrode is disposed in contact with the dielectric layer so that an electric field is applied to the dielectric layer.

Specifically, the following configuration is included.
(i) A light emitting device including a gas layer, a dielectric layer, a porous light emitting layer, a pair of electrodes consisting of an A electrode and a B electrode, and a C electrode, wherein the porous layer is in contact with the dielectric layer between partition walls. A phosphor layer, and the gas layer is disposed in contact with the porous phosphor layer gas layer, a translucent substrate is disposed on the partition wall, and the pair of electrodes includes at least the dielectric layer. The C electrode is provided in contact with the dielectric layer so that an electric field is applied to the dielectric layer.
(ii) A light emitting device including a gas layer, a dielectric layer, a porous light emitter layer, a pair of electrodes consisting of an A electrode and a B electrode, and a C electrode, wherein the dielectric is provided with a concave portion and a convex portion, The porous light emitter layer is disposed in contact with the dielectric layer in the concave portion of the body, and the gas layer is disposed in contact with the gas layer of the porous light emitter layer, on the convex portion of the dielectric. A translucent substrate, and the pair of electrodes are disposed in contact with the translucent substrate or the convex portion of the dielectric so that an alternating electric field is applied to at least a part of the dielectric layer, The C electrode is provided in contact with the dielectric layer so that an electric field is applied to the dielectric layer.
(iii) A light emitting device including a gas layer, a dielectric layer, a porous light emitter layer, a pair of electrodes composed of an A electrode and a B electrode, and a C electrode, wherein the pair of electrodes is at least part of the dielectric layer Are arranged in contact with the dielectric layer so that an alternating electric field is applied thereto, and the gas layer is arranged in contact with the porous light emitter layer gas layer, and at least a part of the gas layer is connected to the A electrode. Located on a straight line connecting the B electrodes, the porous light emitter is disposed in contact with the dielectric layer, and the C electrode is in contact with the dielectric layer so that an electric field is applied to the dielectric layer. Provide.
(iv) A light emitting device including a gas layer, a dielectric layer, a porous luminescent layer, a pair of electrodes consisting of an A electrode and a B electrode, and a C electrode, wherein the porous layer is in contact with the dielectric layer between partition walls. A phosphor layer, and the gas layer is disposed in contact with the porous phosphor layer gas layer, a translucent substrate is disposed on the partition wall, and the pair of electrodes includes at least the dielectric layer. The C electrode is embedded in the dielectric layer so that an electric field is applied to the dielectric layer.

  By configuring as described above, when an alternating voltage is applied between the A electrode and the B electrode and the breakdown voltage of the gas is reached by the increase of the applied voltage, primary electrons and ultraviolet rays are generated in the gas layer. The electrons generated at this time are pulled in the direction of the porous light emitter layer due to the influence of the dielectric layer, and the electrons are injected into the porous light emitter layer. Therefore, creeping discharge (electron avalanche) occurs in the light emitting layer having a porous structure, and electron multiplication occurs. As a result, the luminescent center of the phosphor particles in the porous luminescent layer is excited and the porous luminescent layer emits light uniformly and evenly. In addition, the light emission centers of the phosphor particles in the porous light emitting layer are excited by the ultraviolet rays generated in the gas layer to emit light. At that time, by applying a voltage to the C electrode provided in contact with the dielectric layer, the light emission level of the light emitting layer can be adjusted. That is, if 0 bias or + bias is applied to the C electrode, the density of electrons pulled in the direction of the porous light emitter layer is increased, and as a result, the degree of light emission is enhanced. On the contrary, if a bias is applied, the density of electrons pulled in the direction of the porous light emitter layer is lowered, and as a result, the degree of light emission is suppressed. As described above, in the present invention, by arranging the C electrode in contact with the dielectric, the light emission intensity of the porous light emitter layer can be adjusted, and the gradation of the light emission luminance can be displayed.

  As described above, the light emitting device of the present invention is a light emitting device including a gas layer, a dielectric layer, a porous light emitter layer, a pair of electrodes composed of an A electrode and a B electrode, and a C electrode, and the porous light emitter. The layer is disposed in contact with the dielectric layer, the gas layer is disposed in contact with the porous light emitter layer gas layer, and the pair of electrodes including the A electrode and the B electrode is formed of the dielectric layer. It is arranged so that an alternating electric field is applied to at least a part, and the C electrode is provided in contact with the dielectric layer so that an electric field is applied to the dielectric layer.

  The gap between the gas layers can be arbitrary, but is preferably provided in the range of 1 μm to 300 μm. If it is less than 1 μm, it tends to be difficult to control the gap, and if it exceeds 300 μm, it tends to be difficult to cause dielectric breakdown. In general, 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). When the pressure is reduced, dielectric breakdown occurs at 300 V or lower, but when a high voltage is applied, damage is caused to various parts of the cell structure. Therefore, the range of the interval is preferable in order to apply a voltage that does not cause damage. The interval is more preferably 10 μm or more and 100 μm or less.

  The formation of the porous phosphor layer of the present invention does not require a thin film formation process, a vacuum system, a carrier multiplication layer, etc., and the structure of the light emitting device itself constructed using it is relatively simple. It has the feature that it is easy to manufacture. In addition, the light emitting device of the present invention causes dielectric breakdown in the gas layer, and as a result, the emitted primary electrons and ultraviolet rays are injected into the light emitting layer having a porous structure, and the primary electrons cause creeping discharge in the light emitting layer. It is characterized in that it is generated to excite the emission center of the phosphor particles, and further emits light by ultraviolet excitation. Therefore, the light emitting device of the present invention has good luminous efficiency, and consumes relatively little power when a display is manufactured. It will be small. Furthermore, the light-emitting element of the present invention can easily avoid crosstalk during light emission by providing a partition as a means for separating the light emission color between adjacent porous light-emitting layers.

  Here, crosstalk refers to a phenomenon in which the light emission between pixels adjacent to a certain pixel influences each other to lower the light emission efficiency.

  The discharge separation means of the present invention is particularly preferably configured by providing partition walls and / or spaces. The partition wall separating the porous light emitting layer is preferably an electrical insulator having a thickness of 80 to 300 μm.

When the partition wall is used, it is preferably formed of an inorganic material. As the inorganic material, glass, ceramic, dielectric 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), etc.

  In the present invention, by applying an alternating electric field between a pair of electrodes, the emitted electrons generate a creeping discharge in an avalanche in the porous luminescent layer. As a result, the luminescent center is excited by the emitted electrons to cause the porous luminescent material to emit light. A DC electric field may be used instead of the alternating electric field.

  Next, in the display device of the present invention, for example, white light may be emitted from all pixels using the light emitting element, and color display may be performed for each pixel using a color filter layer. A plurality of B light emitting cells may be arranged and displayed in color.

  Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1)
FIG. 1 is a cross-sectional view of a light-emitting element in this embodiment mode, and FIGS. 2 to 6 are views for explaining a manufacturing process of the light-emitting element in this embodiment mode. In these figures, 100 is a gas layer, 1 is a light emitting element, 2 is a porous light emitter layer, 3 is a phosphor particle, 4 is an insulating layer, 5 is a substrate, 6 is an A electrode, 7 is a B electrode, and 8 is a transparent material. An optical substrate, 10 is a dielectric layer, 11 is a partition, and 17 is a C electrode. FIG. 7 is an enlarged schematic view of the cross section of the porous light emitting layer in the present embodiment, and FIG. 8 is a cross sectional view of another light emitting element in the present embodiment. Further, FIG. 9 is a diagram showing an example of a voltage applied to the C electrode in the present embodiment, and FIGS. 10 and 11 are generated by applying an alternating voltage between the A electrode and the B electrode in the present embodiment. It is a schematic diagram showing how primary electrons are accelerated when a positive voltage and a negative voltage are respectively applied to a C electrode.

As shown in FIG. 2, Ag paste was baked to a thickness of about 300 μm and a thickness of about 30 μm on one surface of a ceramic substrate 5 having a thickness of about 1 mm to form a C electrode 17 on the surface of the substrate 5. . Next, the dielectric layer 10 was formed on the C electrode 17 as shown in FIG. Specifically, a slurry obtained by kneading α-terpineol 40 wt% and ethyl cellulose 5 wt% in a powder obtained by mixing 15 wt% of glass powder with 40 wt% of BaTiO ₃ powder is screen-printed in a predetermined shape. Then, the film was dried and heat-treated at 400 to 600 ° C. in the atmosphere to form the dielectric layer 10 having a thickness of about 200 μm. The relative dielectric constant ε at this time was 50 to 100.

In this embodiment, a BaTiO ₃ system is used as the dielectric, but the same effect can be obtained by using a dielectric such as SrTiO ₃ , CaTiO ₃ , MgTiO ₃ , PZT (PbZrO ₃ ), or PbTiO _3. can get. The same effect can be obtained by using Al ₂ O ₃ -based, MgO-based, ZrO ₂ -based dielectrics, but the luminous intensity is weaker than that of the dielectric having a large relative dielectric constant ε. However, this can be improved by reducing the thickness of the dielectric layer. Further, the dielectric layer can be formed by a thin film forming process such as sputtering, CVD, vapor deposition, sol / gel or the like.

  Of course, the ceramic substrate 5 and the dielectric layer 10 may be used as a sintered body of the same dielectric, and if the sintered body of the dielectric layer is directly baked with the C electrode 17, the substrate is particularly used. 5 may not be used. The dielectric constant was larger when a dielectric sintered body was used.

The BaTiO ₃ powder used was mixed with various additives so that the relative dielectric constant ε when it was made into a sintered body was 2000. The thickness of the dielectric layer differs considerably when a sintered body is used or when it is formed by a thick film process. Therefore, the thickness of the dielectric layer is actually adjusted in consideration of the capacitance component and the relative dielectric constant.

Next, a glass paste was screen printed or transferred to both ends of the dielectric layer 10 and repeatedly dried several times before being sintered at 600 ° C. Thereby, as shown in FIG. 4, the partition wall 11 having a thickness of about 100 to 500 μm was formed. The partition wall 11 can also be formed using a glass paste containing ceramic particles made of a dielectric. Specifically, a paste obtained by adding 50 wt% of α-terpineol to 50 wt% of mixed particles of BaTiO ₃ and glass (3: 1 by weight) and kneading is screen printed in a predetermined pattern and then dried. By repeatedly adjusting the printed thickness to be about 120 to 600 μm and heat-treating at 400 to 600 ° C. for 2 to 5 hours in the N ₂ atmosphere, the partition wall 11 having the above thickness was formed. . If a thin film forming technique is used, it is possible to form a considerably thin partition wall 11 corresponding to the thickness of the porous light emitter layer 2. In FIG. 1, the width of the partition walls is about 50 μm, the height is about 150 μm, and the distance between the partition walls is about 250 μm.

Next, the porous light emitting layer 2 was formed on the dielectric layer 10 in a predetermined pattern by screen printing as follows. First, phosphor particles 3 whose surfaces were coated with an insulating layer 4 made of a metal oxide such as MgO were prepared. The phosphor particles 3 are inorganic 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. It is possible to use compounds. The method of forming the insulating layer 4 made of MgO on the surface is the same for all phosphor particles. Specifically, the phosphor particles 3 are added to the Mg precursor complex solution and stirred for a long time, and then the phosphors are used. The particles were taken out and dried, and then heat-treated at 400 to 600 ° C. in the atmosphere, whereby a uniform coating layer of MgO, that is, the insulating layer 4 was formed on the surface of the phosphor particles 3.

  In the present embodiment, paste in which α-terpineol 45 wt% and ethyl cellulose 5 wt% are kneaded with 50 wt% phosphor particles having the insulating layer 4 is prepared for each phosphor. By repeating the operation of screen printing and drying a plurality of times, the printed porous light-emitting layer 2 was formed as shown in FIG. The thickness was adjusted to about 120 μm and the width was about 200 μm.

  In addition, the porous luminous body layer was produced so that light emission in any one of red (R), green (G), and blue (B) could be obtained. In an actual display device or the like, a porous light emitting layer was regularly printed in a predetermined pattern (for example, a stripe shape) for each emission color, thereby forming regularly arranged porous light emitting layers. It is also possible to form a light emitting layer capable of obtaining white light emission, and then perform color separation with a color filter to obtain a desired light emission color.

As described above, the substrate 5 on which the porous luminous body layer 2 is printed is finally heat-treated at 400 to 600 ° C. for 2 to 5 hours in an N ₂ atmosphere, so that a porous light emission having a thickness of 100 μm is obtained. Body layer 2 was formed. In addition, although the thickness of a porous light-emitting body layer can be used over the range of 40-280 micrometers, the range of 50-120 micrometers is especially suitable.

  The paste was prepared by adding an organic bander or an organic solvent to the phosphor particles, but similar results were obtained using a paste obtained by adding an aqueous colloidal silica solution to the phosphor particles.

  Next, as shown in FIG. 6, a light-transmitting substrate 8 such as a glass plate in which a pair of electrodes such as Ag and Pt made of an A electrode 6 and a B electrode 7 having a thickness of about 30 μm is formed on the partition wall 11. As a result, the light emitting device of this embodiment as shown in FIG. 1 was obtained.

  In the present embodiment, the partition walls are provided after the porous light emitter is formed as described above. However, the order in which the partition walls are formed may be changed. For example, in the light emitting device 1 shown in FIG. 8, the partition wall 11 is formed first, and then the C electrode 17, the dielectric layer 10, and the porous light emitting layer 2 are formed in this order. As described above, the partition wall 11 can be formed in the middle of the above process.

  Further, in the light emitting element in this embodiment mode shown in FIG. 1, the A electrode 6 and the B electrode 7 which are a pair of electrodes are provided on the partition wall 11 so as to be sandwiched between the partition wall and the light transmitting substrate. FIG. 7 is an enlarged schematic view of the cross section of the porous luminous body layer 2 in the present embodiment. 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 mutually bonded. It shows a state in which a porous luminescent layer is formed in a point contact state. In the present embodiment, when primary electrons are injected into the phosphor layer having the porous structure shown in FIG. 7, creeping discharge is generated in the porous phosphor layer, and electron multiplication and ultraviolet rays are generated. As a result, the emission center of the phosphor particles is excited and the entire porous light emitting layer emits light efficiently. When the light emitting layer is formed in a dense state, light emission occurs only on the surface of the layer, and the whole light is not emitted, resulting in a decrease in efficiency.

  As described above, since light emission is based on electron irradiation in this embodiment, there are advantages in that light emission efficiency is excellent, that high luminance can be achieved, and that the driving voltage of the light emitting element can be reduced. .

  In this embodiment, since the heat treatment temperature is set to be relatively low when manufacturing the light emitting element, the porosity of the porous light emitting layer is increased, and the density is in the range of 10 to 90% of the theoretical density. It is in. When the porosity is increased and the density is smaller than the above range in terms of the theoretical density, gas emission occurs in the luminous body layer with the luminous efficiency. As a result, the luminous efficiency decreases, which is not preferable. On the contrary, when the porosity is 10% or less, that is, when the density is greater than 90% in theoretical density, the occurrence of creeping discharge inside the light emitting layer is inhibited. As a result, also in this case, the light emission efficiency is lowered. Incidentally, when the density is in the range of 10 to 90% of the theoretical density, as shown in FIG. 7, it is estimated that the phosphor particles are close to a state where they are in point contact with each other so as to be adjacent three-dimensionally.

In the present embodiment, the phosphor particles 3 whose surface is covered with the insulating layer 4 made of MgO are used, but this has a high MgO resistivity (10 ⁹ Ω · cm or more) and creeping discharge. It is because it can generate | occur | produce efficiently. When the resistivity of the insulating layer is low, creeping discharge is difficult to occur, and sometimes a part of the phosphor may be reduced or short-circuited, which is not preferable. For these reasons, it is desirable to coat the phosphor particles with an electrically insulating metal oxide having a high resistivity.

Of course, when the resistivity of the phosphor particles to be used is high, creeping discharge is easily generated without coating with an insulating metal oxide. BaMgAl ₁₀ O ₁₇ : Eu ²⁺ (blue), Zn ₂ SiO ₄ : Mn ²⁺ (green), YBO ₃ : Eu ³⁺ (red) mainly used in the PDP (plasma display panel) used in this example. With such phosphors, creeping discharge was easily generated without coating with an insulating metal oxide. However, the coating with the insulating metal oxide can suppress the deterioration of the luminous efficiency due to the reduction of the phosphor and the short circuit.

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 in addition to the above MgO. The standard free energy of formation ΔG _f ⁰ of these oxides is very small (for example, −100 kcal / mol or less at room temperature) and is a stable substance. In addition, since these insulating layers have high resistivity and are difficult to reduce, they are excellent as protective films that suppress reduction and deterioration of phosphor particles due to electrons, resulting in high durability of the phosphor. Convenient.

  In addition to the sol / gel method described above, the insulating layer can be formed 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. It is desirable that the insulating layer is homogeneous and uniform and does not peel off. When forming the insulating layer, the phosphor particles are immersed in a weak acid solution such as acetic acid, oxalic acid or citric acid, and impurities adhering to the surface. Is preferably washed.

  Furthermore, it is desirable to pre-process phosphor particles in a nitrogen atmosphere at 200 to 500 ° C. for about 1 to 5 hours before forming the insulating layer. Ordinary phosphor particles may contain a large amount of adsorbed water or crystal water, and if an insulating layer is formed in such a state, it may adversely affect the life characteristics such as brightness reduction and emission spectrum shift. Because it becomes. When the phosphor particles are washed with a weakly acidic solution, the above pretreatment is performed after thoroughly washing with water.

  Moreover, what should be noted in the heat treatment step for forming the porous light-emitting layer is the heat treatment temperature and atmosphere. In this embodiment, since the heat treatment was performed in a temperature range of 450 to 1200 ° C. in a nitrogen atmosphere, there was no change in the valence of rare earth atoms doped in the phosphor. However, when processing at a temperature higher than the above temperature range, care must be taken because the valence of rare earth atoms may change and a solid solution composed of an insulating layer and a phosphor may be generated. Furthermore, it is necessary to pay attention to the fact that the density of the porous light-emitting layer increases as the heat treatment temperature rises. Judging from these facts, the heat treatment temperature is preferably in the range of 450 to 1200 ° C. As for the heat treatment atmosphere, a nitrogen atmosphere is preferable so as not to affect the valence of rare earth atoms doped in the phosphor particles.

  The thickness of the insulating layer is set to about 0.1 to 2.0 μm in the present embodiment, but this is determined in consideration of the average particle diameter of the phosphor particles and efficient generation of creeping discharge. When the average particle size of the phosphor is on the order of submicron, it is better to coat relatively thinly. A thick insulating layer is not preferable because it causes a shift in emission spectrum, a decrease in luminance, and the like. Conversely, it is presumed that creeping discharge is slightly less likely to occur when the insulating layer becomes thinner. 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 of the latter with respect to the former.

  Further, noble metals such as Ag and Pt are used for the A electrode 6 and the B electrode 7 because the metal oxidizes violently during light emission. Accordingly, for example, if an MgO coat used in PDP is used, a base metal such as Cu or Ni can be used.

  Next, the light emitting action of the light emitting element 1 will be described with reference to FIG. In order to drive the light emitting element 1 in the atmosphere, an alternating electric field is applied between the A electrode 6 and the B electrode 7 of FIG. By applying the electric field, the inversion of polarization is repeated in the dielectric layer.

  When the breakdown voltage of the gas is reached due to the voltage rise, breakdown occurs in the gas layer 100, and primary electrons and ultraviolet rays are generated. Then, primary electrons are injected into the porous light emitting layer provided in contact with the dielectric layer disposed between the A electrode and the B electrode. In the luminescent layer having a porous structure, creeping discharge (electron avalanche) occurs due to the influence of the injected primary electrons, leading to electron multiplication. As a result, the luminescent center of the phosphor particles in the porous luminescent layer is excited to emit light. At that time, the light emission intensity of the light emitting layer can be adjusted by applying a voltage to the C electrode provided in contact with the dielectric layer. That is, if a positive voltage is applied to the C electrode, the degree of light emission becomes stronger. Conversely, if a negative voltage is applied, the degree of light emission is suppressed, and if the negative voltage is further increased, light emission eventually stops. As described above, in the present embodiment, the degree of light emission of the porous light-emitting layer can be adjusted by disposing the C electrode in contact with the dielectric.

  By changing the waveform of the alternating electric field applied to the pair of electrodes A and B from a sine wave or sawtooth wave to a rectangular wave, and by increasing the frequency from several tens of Hz to several thousand Hz, The emission becomes very intense and the emission brightness is improved. A burst wave is generated as the voltage of the AC electric field increases. The generation frequency of the burst wave was generated just before the peak for the sine wave and at the peak for the sawtooth wave and the rectangular wave, and the emission luminance was improved as the burst wave voltage was increased. When creeping discharge is started in the porous light emitting layer, ultraviolet rays and visible light are also generated. Therefore, it is necessary to suppress the deterioration of the phosphor particles 3 by these light rays, and it is preferable to reduce the voltage after the light emission is started.

  In the present embodiment, by applying an electric field of 0.70 kV between the pair of electrodes AB of the light emitting element 1 in the atmosphere to cause the phosphor particles 3 to emit light, and then applying an alternating electric field of 0.50 kV, The creeping discharge was continued and the emission of the phosphor particles 3 was continued. When the applied electric field is increased, the generation of electrons is promoted. However, when the applied electric field is small, the generation is insufficient.

  Next, the relationship between the voltage between the electrodes A and B, the voltage between the electrodes C and G (G is ground), and the emission intensity will be described. 9A shows the voltage between the electrodes A and B, FIG. 9B shows the voltage between the electrodes C and G, and FIG. 9C shows the emission intensity of the porous light emitting layer. That is, when a rectangular wave power of 100 V (1 kHz) is applied between the electrodes A and B and a rectangular wave power of 50 V (1 kHz) is applied between the electrodes CG, the voltage between the electrodes A and B is H. Light emission is ON when the voltage between the electrodes C-G is L, and when the voltage between the electrodes AB is L and the voltage between the electrodes C-G is H, and light emission is OFF in the other areas. became. This caused a light emission switch function.

  Next, when the voltage between the electrodes A and B and / or the voltage between the electrodes C and G was increased, the emission intensity was increased, and when the voltage was decreased, the emission intensity was decreased and the emission intensity could be adjusted. That is, when a rectangular wave power of 100 V (1 kHz) is applied between the electrodes A and B and a rectangular wave power of 25 V (1 kHz) is applied between the electrodes CG, the light emission intensity of the light emitting region is 10 Cd. When a rectangular wave power of 50 V (1 kHz) is applied between the electrodes CG while maintaining the voltage between the electrodes A and B, the emission intensity of the light emitting region is 25 Cd, and a rectangular voltage of 75 V (1 kHz) is obtained. When wave power was applied, the emission intensity of the light emitting region was 50 Cd, and when 100 V (1 kHz) rectangular wave power was applied, the light emission intensity of the light emitting region was 100 Cd. In this way, the light emission intensity of the porous light-emitting layer could be adjusted, and the gradation of the light emission luminance could be displayed.

  The reason for this will be described with reference to FIGS. FIG. 10 is a schematic diagram showing a state of primary electron emission when a positive voltage is applied to the C electrode 17, and FIG. 11 is a schematic diagram showing a state of primary electron emission when a negative voltage is applied to the C electrode. It is. Primary electrons are emitted between the pair of electrodes AB in a straight line or in a circular arc toward the counter electrode (not shown), but the situation is different when the third electrode C electrode is provided in contact with the dielectric. Come. That is, in a region where the voltage between the electrodes A and B is H and the voltage between the electrodes C and G is L, and a region where the voltage between the electrodes A and B is L and the voltage between the electrodes C and G is H, The primary electrons are emitted while being pulled in the direction of the C electrode as shown in FIG. 10, whereas the primary electrons are emitted away from the C electrode as shown in FIG. 11 in other regions. As a result, in the former case, electrons are efficiently injected into the porous light emitting layer, so that the degree of light emission is remarkably enhanced. On the other hand, in the latter case, injection of electrons into the light emitting layer is remarkably suppressed. Therefore, it becomes difficult to emit light.

In the present embodiment, the impedance relationship between the A, B, and C electrodes is as follows: the impedance between the A electrode and the B electrode is Z _AB , and the impedance between the A electrode and the C electrode is Z _AC and the C electrode. Assuming that the impedance between the B electrodes is Z _CA , it is preferable to set the relationship of these three so that Z _AB > Z _AC + Z _CB . In the present embodiment, as described above, the porous luminous body layer, The dimensions and arrangement of the dielectric layer, A, B, and C electrodes were adjusted, and primary electrons were efficiently emitted between the A and B electrodes.

  Next, the light-emitting element in this embodiment was driven in a rare gas having a negative pressure. Specifically, the light-emitting element 1 of FIG. 1 was inserted into a quartz tube, and a mixed gas of Ne and Xe was sealed in a slightly negative pressure state.

  In order to drive the light emitting element 1, an alternating electric field was applied between the A electrode 6 and the B electrode 7. In this case, the phosphor particles 3 are caused to emit light by applying an electric field of 0.30 kV, and then an alternating electric field of 0.20 kV is applied so that creeping discharge is continuously performed to emit light of the phosphor particles 3. Lasted. The light emission starting voltage could be reduced by using a negative pressure.

  At that time, when a rectangular wave voltage as shown in FIG. 9 is applied to the C electrode (counter electrode is grounded) as an example, a region where the voltage between the electrodes AB is H and the voltage between the electrodes CG is L, and In the region where the voltage between the electrodes A and B is L and the voltage between the electrodes C and G is H, a positive voltage of 0.15 kV is applied and the degree of light emission is remarkably enhanced. The light was suddenly suppressed and no light was emitted in a region where a negative voltage of -0.15 kV was applied.

  Next, the light-emitting element of this embodiment was actually driven in a pressurized rare gas. Specifically, the light-emitting element 1 of FIG. 1 was inserted into a quartz tube, and a mixed gas of Ne and Xe was sealed in a slightly pressurized state.

  In order to drive the light emitting element 1, an alternating electric field was applied between the A electrode 6 and the B electrode 7. In this case, the creeping discharge is continued by applying an electric field of 0.70 kV to cause the phosphor particles 3 to emit light, and then applying an alternating electric field of 0.50 kV in the same manner as driving in the atmosphere. This was done to keep the phosphor particles 3 from emitting light. As a result, it was found that the light emission efficiency was good because light emission with extremely high luminance was obtained compared to driving in the atmosphere.

  At this time, when a rectangular wave voltage as shown in FIG. 9 is applied to the C electrode (counter electrode is grounded) as an example, the emission level is remarkably enhanced in a region where a positive voltage of 0.30 kV is applied. In the region where the voltage suddenly changes from the positive voltage to the negative voltage, the degree of light emission was rapidly suppressed, and light emission was stopped between cds to which a negative voltage of −0.30 kV was applied.

  Further, in actually driving the other light emitting element of the present embodiment shown in FIG. 8 in the atmosphere, an alternating electric field of 0.80 kV is applied between the A electrode 6 and the B electrode 7 to thereby form the phosphor particles 3. By emitting light and then applying an alternating electric field of 0.50 kV, creeping discharge was continuously performed, and the light emission of the phosphor particles 3 was continued. As a result, it was found that light having extremely high luminance can be obtained in the same manner as the light emitting element in the present embodiment shown in FIG.

  At this time, when a rectangular wave voltage as shown in FIG. 9 is applied to the C electrode (counter electrode is grounded) as an example, the degree of light emission is remarkably enhanced in a region where a positive voltage of 0.40 kV is applied. In the region where the voltage suddenly changes from the positive voltage to the negative voltage, the degree of light emission was rapidly suppressed, and light emission was stopped between cds to which a negative voltage of −0.40 kV was applied.

  In addition, the current value during discharge between the pair of electrodes is 0.1 mA or less in any of the above cases, and when the light emission starts, the light emission continues even if the voltage is reduced to about 50 to 80% of the applied voltage. Thus, it was confirmed that the phosphor particles of any of the three colors emit light with high brightness, high contrast, high recognizability, and high reliability.

  As described above, in the present embodiment, it has been confirmed that the light emitting element is driven to emit light not only in the atmosphere but also in a rare gas or a decompressed gas.

  According to the light emitting element of the present embodiment, since the porous light emitting layer is formed by a thick film process or the like, there is no need to use a thin film forming process when manufacturing the light emitting element as in the prior art, and a vacuum system or carrier Since no multiplication layer is required, the structure is simple, and manufacturing and processing are easy.

  Primary electrons generated between the pair of electrodes are injected into the porous light emitting layer, and creeping discharge (electron avalanche) is generated in the light emitting layer. As a result, the entire light emitting layer having a porous structure emits light uniformly. Therefore, light emission with high luminance can be obtained.

  In addition, the light emission efficiency is very good in the light emission by the electrons compared with the light emission of the phosphor by the ultraviolet rays performed in the plasma display. Furthermore, a light-emitting element with relatively low power consumption when used in a large display can be provided. Note that by forming the partition wall, light emission crosstalk can be easily avoided.

  By disposing the C electrode in contact with the dielectric as in the present embodiment, the degree of light emission of the porous light emitting layer can be adjusted.

(Embodiment 2)
The light-emitting element of this embodiment will be described with reference to FIG. FIG. 12 is a cross-sectional view of the light-emitting element in this embodiment. In FIG. 12, 100 is a gas layer, 1 is a light emitting element, 2 is a porous light emitter layer, 6 is an A electrode, 7 is a B electrode, 8 is a translucent substrate, 10 is a dielectric layer, and 17 is a C electrode. .

First, as shown in FIG. 12, a dielectric layer 10 made of a BaTiO ₃ based sintered body having a relative dielectric constant ε: 2000 and a capacity-temperature characteristic B characteristic of about 400 μm was also prepared as a substrate. . A groove (concave portion) having a width of 250 μm and a depth of 150 μm was provided on one surface by cutting, and an Ag paste having a thickness of 30 μm was baked as a C electrode on the other surface.

In this embodiment, a BaTiO ₃ system is used as the dielectric, but the same effect can be obtained by using a dielectric such as SrTiO ₃ , CaTiO ₃ , MgTiO ₃ , PZT (PbZrO ₃ ), or PbTiO _3. can get. The same effect can be obtained even when a dielectric such as Al ₂ O ₃ , MgO, or ZrO ₂ is used.

A porous light emitting layer is applied to the recesses on the surface of the dielectric layer 10. For the production of the porous light emitting layer in the present embodiment, BaMgAl ₁₀ O ₁₇ : Eu ²⁺ (blue), Zn ₂ SiO ₄ : Mn ²⁺ (green), YBO ₃ having an average particle diameter of 2 to 3 μm: Phosphor particles made of an inorganic compound such as Eu ³⁺ (red) were used. The phosphor particles 3 and the colloidal silica aqueous solution were mixed, applied by spraying, and dried at 150 ° C. for 10 to 30 minutes with a dryer. This process was repeated a plurality of times, and the protruding portion was wiped off to form a porous luminescent layer 2 having a thickness of about 120 μm in the recess.

  When the density of the porous light emitting layer is 90% or more of the theoretical density, when electrons collide with the light emitting layer, light is emitted on the surface, but electrons are not injected into the light emitting layer. Since no light is emitted, the light emission efficiency is low. Therefore, the density of the porous illuminant in this embodiment is theoretically such that electrons generated by the creeping discharge are smoothly injected into the porous illuminant layer, and the creeping discharge also occurs inside the porous illuminant layer. It is desirable to have a porous structure less than 90% of the density. On the contrary, if the density of the porous illuminant becomes very small, that is, if the porosity becomes extremely large, the luminous efficiency will decrease, and the creeping discharge will not easily occur inside the porous illuminant layer, so the density will be theoretical. A range of 10 to 90% of the density is preferred. In particular, a range of 50 to 85% is preferable.

  In addition, although the porous luminous body layer of this embodiment is spray-coated using colloidal silica, it is also possible to paste it with an organic solvent or the like and form the porous luminous body layer on the dielectric layer by screen printing. is there. Specifically, as in the first embodiment, a paste in which α-terpineol 45 wt% and ethyl cellulose 5 wt% are kneaded with 50 wt% phosphor particles having the insulating layer 4 is prepared for each phosphor. A porous light-emitting layer having a desired thickness is formed by repeatedly performing an operation of screen printing in a groove (concave portion) provided on the surface of the dielectric layer and then drying it a plurality of times and then performing heat treatment at 600 ° C. It is possible.

  After that, a translucent substrate 8 such as a glass plate on which a pair of electrodes such as Ag and Pt composed of an A electrode 6 and a B electrode 7 having a thickness of about 30 μm is formed is attached to the convex portion of the dielectric layer. Thus, the convex portion of the dielectric layer can function as a partition wall. Further, as in the first embodiment, when the A electrode and the B electrode are formed on the dielectric layer with the partition interposed, that is, the respective electrodes are formed on the dielectric layer with a different material interposed. In this embodiment, since the pair of electrodes are formed directly on the dielectric layer, which is a uniform material, primary electrons are efficiently generated by reversing the polarization of the dielectric layer. As a result, the luminous efficiency can be improved. In the above-described method for manufacturing a light emitting element, the A electrode and the B electrode are formed in contact with the convex portion of the dielectric layer. There is no problem. An example of the light emitting element thus formed is shown in FIG.

  Next, the light emitting action of the light emitting element 1 will be described with reference to FIG. In order to drive the light emitting element 1 in the atmosphere, an alternating electric field is applied between the A electrode 6 and the B electrode 7 of FIG. By applying the alternating electric field, the polarization inversion is repeated in the dielectric layer.

  When the breakdown voltage of the gas is reached due to the voltage rise, breakdown occurs in the gas layer 100, and primary electrons and ultraviolet rays are generated. Primary electrons are injected into the porous light emitting layer provided in contact with the dielectric layer disposed between the A electrode and the B electrode. In the light emitting layer having a porous structure, creeping discharge (electron avalanche) occurs due to the influence of the injected primary electrons, resulting in electron multiplication. As a result, the luminescent center of the phosphor particles in the porous luminescent layer is excited to emit light. At that time, by applying a voltage to the C electrode provided in contact with the dielectric layer, the light emission level of the light emitting layer can be adjusted. That is, if a positive voltage is applied to the C electrode, the degree of light emission becomes stronger. Conversely, if a negative voltage is applied, the degree of light emission is suppressed, and if the negative voltage is further increased, light emission eventually stops. As described above, in the present embodiment, the light emission intensity of the porous light emitter layer can be adjusted by disposing the C electrode in contact with the dielectric.

  In addition, as described above, in this embodiment, since the pair of electrodes are formed directly on the dielectric layer, primary electrons are efficiently generated by reversing the polarization of the dielectric layer, and as a result, the driving voltage is reduced. Can be reduced.

  Electrons are emitted by changing the waveform of the alternating electric field applied to the pair of electrodes consisting of the A and B electrodes from a sine wave or a sawtooth wave to a rectangular wave, and by increasing the frequency from several tens of Hz to several thousand Hz. Becomes very intense, and the luminance is improved. A burst wave is generated as the voltage of the AC electric field increases. The generation frequency of the burst wave was generated just before the peak for the sine wave and at the peak for the sawtooth wave and the rectangular wave, and the emission luminance improved as the burst wave voltage was increased. When creeping discharge is started in the porous light emitting layer, ultraviolet rays and visible light are also generated. Therefore, it is necessary to suppress the deterioration of the phosphor particles 3 by these light rays, and it is preferable to reduce the voltage after the light emission is started.

  In the present embodiment, an alternating electric field of 0.70 kV is applied to the pair of electrodes in the atmosphere to cause the phosphor particles 3 to emit light, and then an alternating electric field of 0.50 kV is applied to cause creeping discharge. The phosphor particles 3 were kept emitting light continuously. When the applied electric field is increased, the generation of electrons is promoted. However, when the applied electric field is small, the generation is insufficient.

  At that time, when a rectangular wave voltage as shown in FIG. 9 is applied to the C electrode (counter electrode is grounded) as an example, the light emission level is remarkably enhanced in a region where a positive voltage of 0.30 kV is applied. In the region where the voltage suddenly changed from a positive voltage to a negative voltage, the degree of light emission was rapidly suppressed, and no light was emitted between cds to which a negative voltage of −0.30 kV was applied.

In the present embodiment, the impedance relationship between the A, B, and C electrodes is as follows: the impedance between the A electrode and the B electrode is Z _AB , and the impedance between the A electrode and the C electrode is Z _AC and the C electrode. Assuming that the impedance between the B electrodes is Z _CA , it is preferable to set the relationship of these three so that Z _AB > Z _AC + Z _CB . In the present embodiment, as described above, the porous luminous body layer, The dimensions and arrangement of the dielectric layer, A, B, and C electrodes were adjusted.

  In addition, when actually driving other light emitting elements in the present embodiment shown in FIG. 13 in the atmosphere, an alternating electric field of 0.60 kV is applied between the A electrode 6 and the B electrode 7 so that the phosphor particles 3 are attached. By emitting light and then applying an alternating electric field of 0.40 kV, creeping discharge was continuously performed, and the light emission of the phosphor particles 3 was continued. As a result, it was found that light with extremely high luminance can be obtained in the same manner as the light emitting element of FIG.

  At this time, when a rectangular wave voltage as shown in FIG. 9 is applied to the C electrode (counter electrode is grounded) as an example, the emission level is remarkably enhanced in a region where a positive voltage of 0.30 kV is applied. In the region where the voltage suddenly changes from the positive voltage to the negative voltage, the degree of light emission was rapidly suppressed, and light emission was stopped between cds to which a negative voltage of −0.30 kV was applied.

  In addition, the current value during discharge between the pair of electrodes is 0.1 mA or less in any of the above cases, and when the light emission starts, the light emission continues even if the voltage is reduced to about 50 to 80% of the applied voltage. Thus, it was confirmed that the phosphor particles of any of the three colors emit light with high brightness, high contrast, high recognizability, and high reliability.

  As described above, in the present embodiment, it has been confirmed that the light emitting element is driven to emit light not only in the atmosphere but also in a rare gas or a decompressed gas.

  According to the light emitting element of the present embodiment, since the porous light emitting layer is formed by a thick film process or the like, there is no need to use a thin film forming process when manufacturing the light emitting element as in the prior art, and a vacuum system or carrier Since no multiplication layer is required, the structure is simple, and manufacturing and processing are easy.

  Primary electrons generated between the pair of electrodes are injected into the porous light-emitting layer, and creeping discharge (electron avalanche) is generated in the light-emitting layer. As a result, the entire light-emitting layer emits light, thereby obtaining high-luminance light emission. .

  In addition, the light emission efficiency is very good in the light emission by electrons compared with the light emission of the phosphor by the ultraviolet rays performed in the plasma display. Furthermore, a light-emitting element with relatively low power consumption when used in a large display can be provided. Note that by forming the partition wall, light emission crosstalk can be easily avoided.

  By disposing the C electrode in contact with the dielectric as in the present embodiment, the degree of light emission of the porous light emitting layer can be adjusted.

(Embodiment 3)
The light-emitting element of this embodiment will be described with reference to FIG. FIG. 14 is a cross-sectional view of the light-emitting element in this embodiment. In the figure, 100 is a gas layer, 1 is a light emitting element, 2 is a porous light emitter layer, 6 is an A electrode, 7 is a B electrode, 8 is a translucent substrate, 10 is a dielectric layer, and 17 is a C electrode.

In the third embodiment, the use of the BaTiO ₃ -based smooth dielectric layer 10 having a relative dielectric constant ε: 2000 and capacitance-temperature characteristics B characteristics in which no concave and convex portions are formed on the surface, and a thickness of about 120 μm. A light emitting device was produced in the same manner as in Embodiment 2 except that the porous light emitting layer 2 was provided and that a pair of electrodes were formed with an A electrode 6 and a B electrode 7 having a thickness of 150 μm on the dielectric layer.

  Next, the light emitting action of the light emitting element 1 will be described with reference to FIG. In order to drive the light emitting element 1 in the atmosphere, an alternating electric field is applied between the A electrode 6 and the B electrode 7 of FIG. By applying the alternating electric field, the polarization inversion is repeated in the dielectric layer.

  When the breakdown voltage of the gas is reached due to the voltage rise, breakdown occurs in the gas layer 100, and primary electrons and ultraviolet rays are generated. Primary electrons are injected into the porous light emitting layer provided in contact with the dielectric layer disposed between the A electrode and the B electrode. In the light emitting layer having a porous structure, creeping discharge (electron avalanche) occurs due to the influence of the injected primary electrons, resulting in electron multiplication. As a result, the luminescent center of the phosphor particles in the porous luminescent layer is excited to emit light. At that time, by applying a voltage to the C electrode provided in contact with the dielectric layer, the light emission level of the light emitting layer can be adjusted. That is, if a positive voltage is applied to the C electrode, the degree of light emission becomes stronger. Conversely, if a negative voltage is applied, the degree of light emission is suppressed, and if the negative voltage is further increased, light emission eventually stops. As described above, the present embodiment is characterized in that the degree of light emission of the porous light emitting layer is adjusted by disposing the C electrode in contact with the dielectric.

  In the present embodiment, the pair of electrodes are formed directly on the dielectric layer, and the electrodes themselves also serve as the partition walls. As shown in FIG. Is convenient. In the configuration having the positional relationship as described above, when an alternating voltage is applied between the A electrode and the B electrode, the generated primary electrons easily irradiate the porous luminous body layer as a result of the reversal of polarization in the dielectric layer. Thus, the driving voltage can be reduced. That is, in the present embodiment, at least a part of the porous luminous body layer exists at a position where the A electrode and the B electrode, which are a pair of electrodes, are connected by a straight line. Injection into the porous luminescent layer is performed efficiently.

  Electrons are emitted by changing the waveform of the alternating electric field applied to the pair of electrodes consisting of the A and B electrodes from a sine wave or a sawtooth wave to a rectangular wave, and by increasing the frequency from several tens of Hz to several thousand Hz. Becomes very intense, and the luminance is improved. A burst wave is generated as the voltage of the AC electric field increases. The generation frequency of the burst wave was generated just before the peak for the sine wave and at the peak for the sawtooth wave and the rectangular wave, and the emission luminance improved as the burst wave voltage was increased. When creeping discharge is started in the porous light emitting layer, ultraviolet rays and visible light are also generated. Therefore, it is necessary to suppress the deterioration of the phosphor particles 3 by these light rays, and it is preferable to reduce the voltage after the light emission is started.

  In the light emitting device of the present embodiment, an electric field of 0.60 kV is applied to a pair of electrodes in the atmosphere to cause the phosphor particles 3 to emit light, and then an alternating electric field of 0.40 kV is applied to thereby cause creeping discharge. The phosphor particles 3 were kept emitting light continuously.

  At this time, when a rectangular wave voltage as shown in FIG. 9 is applied to the C electrode (counter electrode is grounded) as an example, the emission level is remarkably enhanced in a region where a positive voltage of 0.30 kV is applied. In the region where the voltage suddenly changes from the positive voltage to the negative voltage, the degree of light emission was rapidly suppressed, and light emission was stopped between cds to which a negative voltage of −0.30 kV was applied.

  The current value during discharge between the pair of electrodes A and B is 0.1 mA or less in any of the above cases, and when light emission starts, the voltage drops to about 50 to 80% of the applied voltage. Even if it was made to emit light, it was confirmed that the light emission of all three colors of phosphor particles was high brightness, high contrast, high recognizability, and high reliability.

  As described above, in the present embodiment, it has been confirmed that the light emitting element is driven to emit light not only in the atmosphere but also in a rare gas or a decompressed gas.

  According to the light emitting element of the present embodiment, since the porous light emitting layer is formed by a thick film process or the like, there is no need to use a thin film forming process when manufacturing the light emitting element as in the prior art, and a vacuum system or carrier Since no multiplication layer is required, the structure is simple, and manufacturing and processing are easy.

  Primary electrons generated between a pair of electrodes are injected into the porous luminescent layer, and creeping discharge (electron avalanche) occurs in the luminescent layer. As a result, the luminescent material has a porous structure as well as the surface of the luminescent layer. Since the entire layer emits light uniformly and uniformly, light emission with high luminance can be obtained.

  In addition, the light emission efficiency is very good in the light emission by electrons compared with the light emission of the phosphor by the ultraviolet rays performed in the plasma display. Furthermore, a light-emitting element with relatively low power consumption when used in a large display can be provided. Note that by forming the partition wall, light emission crosstalk can be easily avoided.

  By disposing the C electrode in contact with the dielectric as in the present embodiment, the degree of light emission of the porous light emitting layer can be adjusted.

(Embodiment 4)
The light-emitting element of this embodiment will be described with reference to FIG. FIG. 15 is a cross-sectional view of the light-emitting element in this embodiment. In the figure, 100 is a gas layer, 1 is a light emitting element, 2 is a porous light emitter layer, 5 is a substrate, 6 is an A electrode, 7 is a B electrode, 8 is a translucent substrate, 10 is a dielectric layer, and 11 is a partition wall. And 17 are C electrodes.

As shown in FIG. 15, the light-emitting element of this embodiment can be manufactured by a method almost similar to that of Embodiment 1. That is, instead of the ceramic substrate 5 in the first embodiment, a BaTiO ₃ dielectric layer 10 having a relative dielectric constant ε of 2000 μm and a capacity-temperature characteristic B characteristic is formed on a surface in advance at a predetermined location. A light emitting device was fabricated in the same manner as in Embodiment 1 except that the prepared substrate 5 was used. That is, a partition, a C electrode, a dielectric layer, and a porous light emitter layer were formed by using the above-described substrate by a thick film formation method, and a light emitting device of this embodiment as shown in FIG. 15 was manufactured.

  Next, the light emitting action of the light emitting element 1 will be described with reference to FIG. In order to drive the light emitting element 1 in the atmosphere, an alternating electric field is applied between the A electrode 6 and the B electrode 7 of FIG. By applying the alternating electric field, the polarization inversion is repeated in the dielectric layer.

  When the breakdown voltage of the gas is reached due to the voltage rise, breakdown occurs in the gas layer 100, and primary electrons and ultraviolet rays are generated. Primary electrons are injected into the porous light emitting layer provided in contact with the dielectric layer disposed between the A electrode and the B electrode. In the light emitting layer having a porous structure, creeping discharge (electron avalanche) occurs due to the influence of the injected primary electrons, resulting in electron multiplication. As a result, the luminescent center of the phosphor particles in the porous luminescent layer is excited to emit light. At that time, by applying a voltage to the C electrode provided in contact with the dielectric layer, the light emission level of the light emitting layer can be adjusted. That is, if a positive voltage is applied to the C electrode, the degree of light emission becomes stronger. Conversely, if a negative voltage is applied, the degree of light emission is suppressed, and if the negative voltage is further increased, light emission eventually stops. As described above, the present embodiment is characterized in that the degree of light emission of the porous light emitting layer is adjusted by disposing the C electrode in contact with the dielectric.

  Electrons are emitted by changing the waveform of the alternating electric field applied to the pair of electrodes consisting of the A and B electrodes from a sine wave or a sawtooth wave to a rectangular wave, and by increasing the frequency from several tens of Hz to several thousand Hz. Becomes very intense, and the luminance is improved. A burst wave is generated as the voltage of the AC electric field increases. The generation frequency of the burst wave was generated just before the peak for the sine wave and at the peak for the sawtooth wave and the rectangular wave, and the emission luminance improved as the burst wave voltage was increased. When creeping discharge is started in the porous light emitting layer, ultraviolet rays and visible light are also generated. Therefore, it is necessary to suppress the deterioration of the phosphor particles 3 by these light rays, and it is preferable to reduce the voltage after the light emission is started.

  In the present embodiment, a creeping discharge is continued by applying an electric field of 0.50 kV to the pair of electrodes in the atmosphere to cause the phosphor particles 3 to emit light, and then applying an alternating electric field of 0.40 kV. In this way, the phosphor particles 3 were kept emitting light. When the applied electric field is increased, the generation of electrons is promoted. However, when the applied electric field is small, the generation is insufficient.

  At this time, when a rectangular wave voltage as shown in FIG. 9 is applied to the C electrode (counter electrode is grounded) as an example, the emission level is remarkably enhanced in a region where a positive voltage of 0.30 kV is applied. In the region where the voltage suddenly changes from the positive voltage to the negative voltage, the degree of light emission was rapidly suppressed, and light emission was stopped between cds to which a negative voltage of −0.30 kV was applied.

In the present embodiment, the impedance relationship between the A, B, and C electrodes is as follows: the impedance between the A electrode and the B electrode is Z _AB , and the impedance between the A electrode and the C electrode is Z _AC and the C electrode. Assuming that the impedance between the B electrodes is Z _CA , it is preferable to set the relationship of these three so that Z _AB > Z _AC + Z _CB . In the present embodiment, as described above, the porous luminous body layer, The arrangement and dimensions of the dielectric layer, the A electrode, and the B electrode were adjusted.

  Further, in the present embodiment, as shown in FIG. 15, the C electrode is embedded in the dielectric layer, and the above-described impedance correlation can be adjusted by the position of the embedded. Further, it is convenient because the voltage applied to the C electrode can be adjusted.

  The current value during discharge between the pair of electrodes A and B is 0.1 mA or less in any of the above cases, and when light emission starts, the voltage drops to about 50 to 80% of the applied voltage. Even if it was made to emit light, it was confirmed that the light emission of all three colors of phosphor particles was high brightness, high contrast, high recognizability, and high reliability.

  As described above, in the present embodiment, it has been confirmed that the light emitting element is driven to emit light not only in the atmosphere but also in a rare gas or a decompressed gas.

  According to the light emitting element of the present embodiment, since the porous light emitting layer is formed by a thick film process or the like, there is no need to use a thin film forming process when manufacturing the light emitting element as in the prior art, and a vacuum system or carrier Since no multiplication layer is required, the structure is simple, and manufacturing and processing are easy.

  Primary electrons generated between the pair of electrodes are injected into the porous light-emitting layer, and creeping discharge (electron avalanche) is generated in the light-emitting layer. As a result, light is emitted, whereby high-luminance light emission is obtained.

  In addition, the light emission efficiency is very good in the light emission by electrons compared with the light emission of the phosphor by the ultraviolet rays performed in the plasma display. Furthermore, a light-emitting element with relatively low power consumption when used in a large display can be provided. Note that by forming the partition wall, light emission crosstalk can be easily avoided.

  By disposing the C electrode in contact with the dielectric as in the present embodiment, the degree of light emission of the porous light emitting layer can be adjusted.

(Embodiment 5)
In the light-emitting element of this embodiment, a porous light-emitting layer will be described in particular with reference to FIGS.

  16 and 17 are schematic views in which the cross section of the porous light emitting layer in the present embodiment is enlarged. In these figures, 2 is a porous luminescent layer, 3 is a phosphor particle, 4 is an insulating layer, and 18 is an insulating fiber. Insulating beads 400 may be present as shown in FIG.

In the present embodiment, the porous luminous body layer 2 composed of the phosphor particles and the insulating fibers 18 such as ceramics and glass beads or the insulating beads 400 is formed regardless of the presence or absence of the insulating layer on the surface of the phosphor particles. As an example of the insulating fiber 18, SiO ₂ —Al ₂ O ₃ —CaO based fiber is used, and the diameter is preferably 0.1 to 5 μm and the length is preferably 0.5 to 20 μm. By using a mixture of sized fibers in a ratio of 2 parts by weight of phosphor particles and 1 part by weight of fibers, the porosity becomes relatively large, and as a result, creeping discharge is generated evenly inside the porous phosphor layer. This is preferable. In this embodiment, when forming the porous luminous body layer, a paste is prepared by kneading α-terpineol 45 wt% and ethyl cellulose 5 wt% with respect to 50 wt% of the mixture of phosphor particles and insulating fibers. In the same manner as in Form 1, the paste was screen-printed to form a porous luminescent layer. 16 and 17 are enlarged schematic views showing the cross section of the porous light emitting layer containing the insulating fiber 18 obtained as described above. FIG. 16 shows a porous phosphor layer 2 composed of phosphor particles 3 whose surfaces are covered with an insulating layer 4 and insulating fibers 18, and FIG. 17 shows a porous phosphor layer 2 composed of phosphor particles 3 and insulating fibers. It is.

FIG. 25 is a cross-sectional view of a light-emitting element using the porous light-emitting layer 2 containing SiO ₂ glass beads 200 having a diameter of about 10 μm, and FIG. 26 is a partially enlarged cross-sectional view of the porous light-emitting layer 2. . FIG. 27 is a cross-sectional view in which a SiO ₂ —Al ₂ O ₃ —CaO-based fiber 300 is present in a porous luminous body layer.

  A light-emitting element similar to that of Embodiment 1 was manufactured using such a porous light-emitting layer.

The reason why SiO ₂ —Al ₂ O ₃ —CaO fibers or SiO ₂ beads are selected as the insulating fibers is that they are thermally and chemically stable and have a resistivity of 10 ⁹ Ω · cm or more, porous A large porosity of 10 to 90% is easily obtained in the phosphor layer, and discharge is likely to occur on the surface of the fiber, resulting in occurrence of creeping discharge in the entire porous phosphor layer. It is. In addition to the above, substantially the same result can be obtained by using insulating fibers or beads containing SiC, ZnO, TiO ₂ , MgO, BN, or Si ₃ N ₄ series.

  Next, the light emitting action of the light emitting element 1 will be described with reference to FIG. In order to drive the light emitting element 1 in the atmosphere, an alternating electric field is applied between the A electrode 6 and the B electrode 7 of FIG. By applying the alternating electric field, the polarization inversion is repeated in the dielectric layer.

  When the breakdown voltage of the gas is reached due to the voltage rise, breakdown occurs in the gas layer 100, and primary electrons and ultraviolet rays are generated. Primary electrons are injected into the porous light emitting layer provided in contact with the dielectric layer disposed between the A electrode and the B electrode. In the light emitting layer having a porous structure, creeping discharge (electron avalanche) occurs due to the influence of the injected primary electrons, resulting in electron multiplication. As a result, the luminescent center of the phosphor particles in the porous luminescent layer is excited to emit light. At that time, by applying a voltage to the C electrode provided in contact with the dielectric layer, the light emission level of the light emitting layer can be adjusted. That is, if a positive voltage is applied to the C electrode, the degree of light emission becomes stronger. Conversely, if a negative voltage is applied, the degree of light emission is suppressed, and if the negative voltage is further increased, light emission eventually stops. As described above, the present embodiment is characterized in that the degree of light emission of the porous light emitting layer is adjusted by disposing the C electrode in contact with the dielectric.

  Electrons are emitted by changing the waveform of the alternating electric field applied to the pair of electrodes consisting of the A and B electrodes from a sine wave or a sawtooth wave to a rectangular wave, and by increasing the frequency from several tens of Hz to several thousand Hz. Becomes very intense, and the luminance is improved. A burst wave is generated as the voltage of the AC electric field increases. The generation frequency of the burst wave was generated just before the peak for the sine wave and at the peak for the sawtooth wave and the rectangular wave, and the emission luminance improved as the burst wave voltage was increased. When creeping discharge is started in the porous light emitting layer, ultraviolet rays and visible light are also generated. Therefore, it is necessary to suppress the deterioration of the phosphor particles 3 by these light rays, and it is preferable to reduce the voltage after the light emission is started.

  In the present embodiment, in the atmosphere, an electric field of 0.50 kV is applied to the pair of electrodes in any light emitting element to cause the phosphor particles 3 to emit light, and then an alternating electric field of 0.40 kV is applied. As a result, the surface discharge was continued and the emission of the phosphor particles 3 was continued. When the applied electric field is increased, the generation of electrons is promoted. However, when the applied electric field is small, the generation is insufficient.

  At this time, when a rectangular wave voltage as shown in FIG. 9 is applied to the C electrode (counter electrode is grounded) as an example, the emission level is remarkably enhanced in a region where a positive voltage of 0.30 kV is applied. In the region where the voltage suddenly changes from the positive voltage to the negative voltage, the degree of light emission was rapidly suppressed, and light emission was stopped between cds to which a negative voltage of −0.30 kV was applied.

  In addition, the current value during discharge between the pair of electrodes is 0.1 mA or less in any of the above cases, and when the light emission starts, the light emission continues even if the voltage is reduced to about 50 to 80% of the applied voltage. Thus, it was confirmed that the phosphor particles of any of the three colors emit light with high brightness, high contrast, high recognizability, and high reliability.

  As described above, in the present embodiment, it has been confirmed that the light emitting element is driven to emit light not only in the atmosphere but also in a rare gas or a decompressed gas.

According to the light emitting element of the present embodiment, since the porous light emitting layer is formed by a thick film process or the like, there is no need to use a thin film forming process when manufacturing the light emitting element as in the prior art, and a vacuum system or carrier Since no multiplication layer is required, the structure is simple, and manufacturing and processing are easy.
Primary electrons generated between a pair of electrodes are injected into the porous luminescent layer, and creeping discharge (electron avalanche) occurs in the luminescent layer. As a result, the entire interior of the porous luminescent layer emits light. Luminous emission is obtained.

  In addition, the light emission efficiency is very good in the light emission by electrons compared with the light emission of the phosphor by the ultraviolet rays performed in the plasma display. Furthermore, a light-emitting element with relatively low power consumption when used in a large display can be provided. Note that by forming the partition wall, light emission crosstalk can be easily avoided.

  By disposing the C electrode in contact with the dielectric as in the present embodiment, the degree of light emission of the porous light emitting layer can be adjusted.

(Embodiment 6)
The display device of this embodiment and its operation will be described with reference to FIG. FIG. 19 is an exploded perspective view of the display device in this embodiment. In the figure, 2 is a porous luminescent layer, 5 is a substrate, 8 is a translucent substrate, 10 is a dielectric layer, 11 is a partition, 21 is an address electrode (C electrode), 22a is a display electrode (A electrode), Reference numeral 22b denotes a display electrode (B electrode) and 30 denotes a display device.

  Such an array of light-emitting elements in this embodiment can be manufactured by the method described in Embodiment 1. That is, the address electrode 21 is formed on the substrate 5, the dielectric layer 10 and the porous light emitting layer 2 are formed thereon in this order, and then the partition wall 11 is formed. Finally, the display electrodes 22a and 22b are formed. The formed translucent substrate 8 is attached to the partition wall 11. In this embodiment, the partition is provided after the porous light emitter is formed as described above, but the C electrode, the dielectric layer, and the porous light emitter layer are respectively formed after the partition is first formed. The barrier ribs may be formed in this order, and the partition walls may be formed at any time during the above process.

  As shown in FIG. 19, an outline of the resulting array of light-emitting elements is such that partition walls 11 having a height of about 130 μm and a width of about 50 μm are arranged in a stripe pattern on the substrate 5 with an interval of about 250 μm. Between the partition walls, a striped porous light-emitting layer 2 having a width of about 200 μm and a thickness of about 100 μm is disposed so that red (R) green (G) and blue (B) color can be obtained. A striped dielectric layer 10 having a thickness of about 200 μm is formed on the lower surface of the porous luminous body layer, and the C electrode described in the first embodiment is in contact with the lower surface of the dielectric layer. Address electrodes 21 corresponding to are formed in a stripe shape. The translucent substrate 8 is disposed on the array of light emitting elements configured as described above. As described in the first embodiment, the surface of the translucent substrate 8 facing the porous light emitting layer 2 is a display electrode 22a corresponding to a pair of electrodes composed of an A electrode and a B electrode made of striped ITO. , 22b are formed at an interval of about 100 μm so as to intersect the address electrode 21 described above.

  Note that the array of the light emitting elements 1 shown in FIG. 19 described above is one in which the porous light emitter layer 2 and the partition walls 11 are both arranged in a stripe shape, but as another light emitting element array of the present embodiment, it is porous. It is also possible to fabricate the phosphor layers 2 arranged in a lattice pattern by the same method as in the first embodiment. A plurality of porous phosphor layers 2 formed in contact with the dielectric layer 10 are latticed. A light-emitting element array arranged in a shape is shown in FIG. In such an array of light emitting elements, as shown in the figure, if a grid-like partition wall is formed using a thick film forming method so as to surround each light emitting element alone, crosstalk during light emission can be ensured. Can be avoided.

  Next, the light emitting action of the light emitting element array will be described with reference to FIGS. An alternating electric field is applied to the display electrodes in order to drive each array of light emitting elements in the atmosphere. By applying the alternating electric field, the polarization inversion is repeated in the dielectric layer.

  When the voltage gradually increases and reaches the dielectric breakdown voltage of the gas, primary electrons are generated. The porous phosphor layer is irradiated with the emitted electrons, and the electrons are injected into the phosphor layer. As a result, creeping discharge (electron avalanche) occurs in the phosphor layer having the porous structure of the present invention, resulting in electron multiplication, and the emission center of the phosphor particles constituting the porous phosphor layer is an electron. Excites and emits light. At that time, light emission of the light emitting layer can be turned ON / OFF by applying a voltage to the address electrode. That is, if a positive voltage is applied to the address electrode, light emission is turned on, and conversely, if a negative voltage is applied, light emission is turned off. As described above, in the present embodiment, the address electrode is arranged in contact with the dielectric layer, thereby turning on / off the light emission of the porous light emitter layer.

  In the present embodiment, in any light emitting element array, a 0.71 kV electric field is applied to the display electrode to cause the phosphor particles 3 to emit light, and then an alternating electric field of 0.50 kV is applied to thereby cause creeping discharge. To continue the light emission of the porous light emitter layer 2. When the applied electric field is increased, the generation of electrons is promoted. However, when the applied electric field is small, the generation is insufficient. Further, it was possible to stop the light emission by applying a voltage of −0.62 kV to the address electrode while the light emission was continued.

  As described above, the characteristics of the display device in this embodiment are almost the same as those of the single element in the first embodiment.

In the present embodiment, the impedance relationship between the A, B, and C electrodes is as follows: the impedance between the A electrode and the B electrode is Z _AB , and the impedance between the A electrode and the C electrode is Z _AC and the C electrode. When the impedance between the B electrodes is Z _CA , the relationship between these three is set as Z _AB > Z _AC + Z _CB , and this is preferable for driving the light emitting element.

  Further, in the above light emitting element array, the current value during discharge between the display electrodes is 0.1 mA or less in all cases, and when light emission starts, light emission occurs even when the voltage is reduced to about 50 to 80% of the applied voltage. As a result, it was confirmed that the light emission of all three colors of phosphor particles was high brightness, high contrast, high recognizability, and high reliability.

  In this embodiment mode, as in the case of the light emitting device of Embodiment Mode 1, it was confirmed that the light emitting device was driven to emit light not only in the atmosphere but also in a rare gas or a decompressed gas.

According to the light-emitting element array of the present embodiment, the porous light-emitting layer is formed by a thick film process or the like as in the first embodiment. Since no vacuum system or carrier multiplication layer is required, the structure is simple, and manufacturing and processing are easy.
Primary electrons generated between the pair of display electrodes are injected into the porous luminous body layer, and creeping discharge (electron avalanche) is generated in the light emitting layer. As a result, light is emitted, resulting in high luminance emission. It is done.

  In addition, the light emission efficiency is very good in the light emission by electrons compared with the light emission of the phosphor by the ultraviolet rays performed in the plasma display. Furthermore, a light-emitting element with relatively low power consumption when used in a large display can be provided.

  Further, in this embodiment mode, a partition wall can be easily formed, which is convenient for avoiding light emission crosstalk.

  A two-dimensional image can be displayed on the array of light emitting elements in this embodiment configured as described above. That is, the light-emitting element 1 of the present embodiment can perform so-called simple matrix driving, and sequentially sends pulse signals to the display electrodes, and puts ON / OFF information in the address electrodes in accordance with the timing, thereby causing the address electrodes and the display electrodes. One line is displayed by emitting light in accordance with ON / OFF of the pixels at the intersections. By sequentially switching the scanning pulse, a two-dimensional image can be displayed. Also, active driving is possible by placing a transistor in each of the pixels arranged in a matrix and turning on / off each pixel.

  In this embodiment, as shown in FIG. 19 and FIG. 20, a partition is provided between the porous light emitter layers to surely avoid crosstalk of light emission. In particular, the light emitting element array shown in FIG. In this case, since the respective light emitting elements are separated from each other, the crosstalk of light emission is almost eliminated without the need to install a partition wall.

  FIG. 21 is a block diagram of a display module using a display panel formed of an array of light emitting elements composed of a porous light emitting layer according to this embodiment. As shown in the figure, display information is first stored in the image memory 23, and then the information is received by the timing controller 25 according to an instruction from the display controller 24. Finally, the display information is displayed on the display panel 28 as an image by a driver IC including a timing controller, an X driver 26, and a Y driver 27. The display panel composed of the light emitting element composed of the porous light emitting layer in this embodiment has extremely good luminous efficiency and power consumption as compared with the phosphor emission by ultraviolet rays performed in the plasma display. Is relatively small.

  By disposing the C electrode in contact with the dielectric as in the present embodiment, the degree of light emission of the porous light emitting layer can be adjusted.

[Industrial applicability]
The present invention uses a porous light-emitting layer as a phosphor layer, and is useful as a light-emitting body in a light-emitting element because light emission can be obtained with a simple structure. Further, the present invention is light emission by creeping discharge by injection of electrons into the porous light-emitting layer, and it is useful as a light-emitting material for general displays because light emission with excellent light emission efficiency can be obtained. It does not use a thin film formation process to form a phosphor layer as in the past, and it has features that it is easy to process because it does not require a vacuum system or a carrier multiplication layer, and it also has low power consumption. It is also useful for manufacturing large displays. Furthermore, the present invention is a light-emitting element composed of a porous light-emitting body layer, and since it is relatively easy to install partition walls between the light-emitting elements, it is useful for avoiding light emission crosstalk.

Sectional drawing of the light emitting element in Embodiment 1 of this invention. 4A and 4B are diagrams for illustrating a manufacturing process of the light-emitting element in Embodiment 1 of the present invention. 4A and 4B are diagrams for illustrating a manufacturing process of the light-emitting element in Embodiment 1 of the present invention. 4A and 4B are diagrams for illustrating a manufacturing process of the light-emitting element in Embodiment 1 of the present invention. 4A and 4B are diagrams for illustrating a manufacturing process of the light-emitting element in Embodiment 1 of the present invention. 4A and 4B are diagrams for illustrating a manufacturing process of the light-emitting element in Embodiment 1 of the present invention. The schematic diagram which expanded the cross section of the porous light-emitting body layer in Embodiment 1 of this invention. Sectional drawing of the other light emitting element in Embodiment 1 of this invention. AC is a figure which shows the voltage and light emission intensity which are applied to the AB electrode and CG electrode in Embodiment 1 of this invention. The schematic diagram which shows the state from which the primary electron is discharge | released when positive voltage is applied to the C electrode in Embodiment 1 of this invention. The schematic diagram which shows the state from which a primary electron is discharge | released when a negative voltage is applied to the C electrode in Embodiment 1 of this invention. Sectional drawing of the light emitting element in Embodiment 2 of this invention. Sectional drawing of the other light emitting element in Embodiment 2 of this invention. Sectional drawing of the light emitting element in Embodiment 3 of this invention. Sectional drawing of the light emitting element in Embodiment 4 of this invention. The schematic diagram which expanded the cross section of the porous light-emitting body layer in Embodiment 5 of this invention. The schematic diagram which expanded the cross section of the porous light-emitting body layer in Embodiment 5 of this invention. The schematic diagram which expanded the cross section of the porous light-emitting body layer in Embodiment 5 of this invention. The disassembled perspective view of the light emitting element array in Embodiment 6 of this invention. The disassembled perspective view of the light emitting element array in Embodiment 6 of this invention. The block diagram of the display module using the display panel comprised by the array of the light emitting element which consists of a porous light-emitting body layer in Embodiment 6 of this invention. Sectional drawing of the light emitting element of the prior art example in nonpatent literature 2. Sectional drawing of the light emitting element of the prior art example in patent document 3. FIG. Sectional drawing of the light emitting element of the prior art example in patent document 5. FIG. 1 is a cross-sectional view of a light-emitting element according to an embodiment of the present invention. The partial expanded sectional view of a porous light-emitting body layer similarly. FIG. 3 is a cross-sectional view in which SiO ₂ —Al ₂ O ₃ —CaO-based fibers are present in a porous luminous body layer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light emitting element 2 Porous light emitter layer 3 Phosphor particle 4 Insulating layer 5 Substrate 6 A electrode 7 B electrode 8 Translucent substrate 10 Dielectric layer 11 Partition 17 C electrode 18 Insulating fiber 21 Address electrode 22a, 22b Display electrode 23 Image memory 24 Display controller 25 Timing controller 26 X driver 27 Y driver 28 Display panel 30 Light emitting element array 100 Gas layer 200 Glass bead 300 SiO ₂ —Al ₂ O ₃ —CaO fiber 400 Insulating bead

Claims (22)

A light emitting device comprising a gas layer, a dielectric layer, a porous light emitter layer, a pair of electrodes consisting of an A electrode and a B electrode, and a C electrode,
The porous phosphor layer is disposed in contact with the dielectric layer;
The gas layer is disposed in contact with the porous light emitter layer;
The pair of electrodes composed of the A electrode and the B electrode are arranged so that an electric field is applied to at least a part of the dielectric layer,
The light emitting device, wherein the C electrode is disposed in contact with the dielectric layer so that an electric field is applied to the dielectric layer.   2. The light emitting device according to claim 1, wherein creeping discharge is generated in the porous light emitting layer to emit light by exciting a light emission center of a phosphor particle constituting the porous light emitting layer.   The alternating voltage is applied to the pair of electrodes to cause dielectric breakdown in the gas layer to generate primary electrons and ultraviolet rays, to excite the porous luminescent layer and to emit light from the porous luminescent layer. 2. The light emitting device according to 1.   The light emitting device according to claim 1, wherein electrons due to creeping discharge are increased in the porous light emitting layer by the primary electrons. The relationship between the impedance Z _AB between the A electrode and the B electrode, the impedance Z _AC between the A electrode and the C electrode, and the impedance Z _CA between the C electrode and the B electrode at the time of light emission of the porous phosphor layer is as follows:
Z _AB > Z _AC + Z _CB
The light emitting device according to claim 1.   The light emitting element according to claim 1, wherein the gas layer between the A electrode and the B electrode as the pair of electrodes exists in a state of normal pressure, negative pressure, or pressurization.   The light emitting device according to claim 6, wherein the gas layer is made of a rare gas, air, oxygen, nitrogen, or a mixture thereof.   The light emitting device according to claim 1, wherein the porous light emitting layer is divided for each pixel, and a partition is provided between adjacent porous light emitting layers.   The light emitting device according to claim 1, wherein the porous light emitting layer emits at least red (R), green (G), or blue (B).   The light emitting device according to claim 1, wherein the porous light emitting layer is composed of continuous pores connected to the surface of the porous light emitting layer, a gas filled in the pores, and phosphor particles.   The light emitting device according to claim 1, wherein the porous light emitting layer is composed of particles in which the surface of phosphor particles is coated with an insulating layer and voids thereof.   The relationship between the average particle diameter of the phosphor particles and the thickness of the insulating layer formed on the surface of the phosphor particles is such that the latter is in the range of 1/10 to 1/500 with respect to the former 1. The light emitting element of description.   The light emitting device according to claim 1, wherein the porous light emitting layer includes continuous pores connected to the surface of the porous light emitting layer, a gas filled in the pores, phosphor particles, and insulating fibers.   The light emitting device according to claim 1, wherein the porous light emitting layer includes continuous pores connected to the surface of the porous light emitting layer, a gas filled in the pores, phosphor particles, and dielectric particles.   The said porous light-emitting body layer contains the continuous pore connected to the porous light-emitting body layer surface, the gas with which the pore was filled, fluorescent substance particle, dielectric material particle, and an insulating fiber. Light emitting element.   The light emitting device according to claim 1, wherein the density of the porous light emitting layer is in the range of 10 to 90% of the theoretical density.   The light emitting device according to claim 1, wherein the pair of electrodes including the A electrode and the B electrode is a display electrode, and the C electrode is an address electrode.   The light emitting device according to claim 1, wherein the gas layer has a range of 1 μm to 300 μm.   The light emitting device according to claim 1, wherein the porous light emitting layer has a thickness in a range of 40 to 280 μm.   The light emitting device according to claim 1, wherein the dielectric layer has a thickness in a range of 10 to 5000 µm.   The luminance adjustment is performed by applying an electric field to a pair of electrodes composed of the A electrode and the B electrode and applying an electric field to the C electrode to change the emission intensity of the porous phosphor layer. Light emitting element.   A light emitting device according to any one of claims 1 to 21, wherein a plurality of the light emitting devices are arranged as light emitting cells of one color or a plurality of colors, and a porous phosphor layer or color of a color corresponding to each light emitting cell. A display device comprising a display panel in which a filter layer is disposed and the porous phosphor layer emits light on a surface.

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