JP5392637B2 - Luminescent display device - Google Patents

Description

  The present invention relates to a light-emitting display device including a pair of substrates each having an electrode formed on each surface facing each other and a light-emitting layer sandwiched between the pair of substrates. The present invention relates to a liquid light-emitting element, a light-emitting display device, and a method for manufacturing a light-emitting display device that can prevent a decrease in the brightness. The present invention also relates to a light emitter formed into a lump shape.

  In recent years, development of light-emitting display devices such as organic EL has been rapidly progressing. Since the light emitting element used in the organic EL light emitting display device is a self light emitting element, it can be made thinner and lighter than a liquid crystal light receiving element that requires a backlight. In addition, since the organic EL light-emitting element is a self-light-emitting element, it is more visible than a liquid crystal light-receiving element. For this reason, the organic EL light-emitting display device has features such as excellent visibility, high-speed display properties, low-voltage drivability, and thinning.

  2. Description of the Related Art An organic EL light emitting display device generally includes a pair of substrates each having an electrode formed on each surface facing each other, and a light emitting layer sandwiched between the pair of substrates. It contains a luminescent material. Among these, the light emitting layer has a thickness of several hundred nm. For this reason, the distance between each electrode which opposes is short, and each electrode is easy to mutually contact. Further, a direct current voltage is applied to the light emitting layer of the organic EL light emitting display device. For this reason, impurities are likely to be accumulated at the interface between the electrodes constituting the organic EL light emitting display device. This shortens the operating life of the light emitting layer used in the organic EL light emitting display device.

In order to solve such a problem, a light emitting display device using a light emitting layer made of a liquid utilizing an electrochemical reaction has been developed (for example, see Patent Documents 1 to 3 and Non-Patent Documents 1 and 2). Among these, in the light emitting display devices in Patent Documents 1 and 2 and Non-Patent Documents 1 and 2, the distance between the pair of electrodes is both several μm or more. For this reason, each electrode does not contact each other. In addition, since an AC voltage is applied to the light-emitting layers of the light-emitting display devices in Patent Documents 1 to 3 and Non-Patent Document 1, the problem of shortening the operating life of the light-emitting layers is solved.
JP 2007-139899 A JP 2006-301302 A JP 2005-302332 A `` Toshiba review vol.60, No.9, P33 (2005) '' "Journal of the Electrochemical Society, Vol.152 (8) pA1677 (2005)"

  As shown in FIG. 5, the light-emitting display device 21 in Patent Documents 1 to 2 and Non-Patent Documents 1 and 2 is sandwiched between a pair of substrates 23 having electrodes 24 formed on opposite surfaces and a pair of substrates 23. And a light emitting layer 25 in which a light emitting substance 28 is dissolved in an electrolyte composed of an organic solvent 26 and a supporting salt 27. Thus, since the flammable organic solvent 26 is used as the light emitting layer 25, there is a problem in safety in handling.

  Moreover, since the organic solvent 26 has volatility, it volatilizes relatively easily. For this reason, there is also a problem that the concentration in the light emitting layer 25 changes, the light emitting layer 25 is deteriorated, and the light emitting characteristics of the light emitting layer 25 are lowered.

  Furthermore, as described above, in the light emitting layer 25 using the organic solvent 26, it is necessary to dissolve the supporting salt 27 in the organic solvent 26 in order to cause the light emitting layer 25 to emit light sufficiently. For this reason, when using the organic solvent 26 as the light emitting layer 25, the kind of material which comprises the light emitting layer 25 increases.

  The present invention has been made in consideration of such points, and is a light-emitting display device that does not use an organic solvent, is excellent in safety, and can prevent deterioration in light-emitting characteristics. An object of the present invention is to provide a liquid light-emitting element, a light-emitting display device, a method for manufacturing a light-emitting display device, and a light-emitting body that can reduce the types of constituent materials.

  The present invention includes a pair of substrates each having electrodes formed on opposite surfaces, and a light emitting layer sandwiched between the pair of substrates. The light emitting layer includes an ionic liquid and the ionic liquid in the ionic liquid. A light-emitting display device including a dissolved light-emitting substance.

  The present invention is a light-emitting display device characterized in that the ionic liquid becomes liquid at room temperature.

  The present invention includes a pair of substrates each having electrodes formed on opposite surfaces, and a light emitting layer sandwiched between the pair of substrates. The light emitting layer includes an ionic liquid and the ionic liquid in the ionic liquid. A light-emitting display device comprising a dissolved light-emitting substance and a gelling material that gels an ionic liquid.

  The present invention is the light-emitting display device, wherein the gelling material is composed of silica nano-sized fine particles or titanium oxide nano-sized fine particles.

  The present invention is a light emitting display device in which the light emitting layer emits light by applying an alternating voltage.

  The present invention is the light-emitting display device in which the ionic liquid includes any one of aliphatic, imidazolium, and pyridium materials.

  The present invention is a light-emitting display device in which the light-emitting substance includes any one of a ruthenium compound / complex, PVB (polyvinyl butyral), DPA (9,10-diphenylanthracene), and perylene.

  The present invention includes a pair of electrodes and a light emitting layer sandwiched between the pair of electrodes, and the light emitting layer includes an ionic liquid and a luminescent material dissolved in the ionic liquid. The liquid light emitting device.

  The present invention includes a step of preparing a pair of substrates each having an electrode formed on one surface thereof, a step of arranging the pair of substrates so that the surfaces on which the electrodes are formed face each other, and a luminescent material in an ionic liquid. A method for manufacturing a light emitting display device, comprising: a step of dissolving; and a step of injecting an ionic liquid in which a light emitting substance is dissolved between a pair of substrates to form a light emitting layer.

  The present invention includes a step of preparing a pair of substrates each having an electrode formed on one surface, a step of dissolving a luminescent material in an ionic liquid, and a luminescent material on the surface of the one substrate on which the electrode is formed. A step of forming a light-emitting layer by applying an ionic liquid in which an electrode is dissolved, and a step of disposing the other substrate on the light-emitting layer so that the surface on which the electrodes are formed faces the light-emitting layer side. A method of manufacturing a light emitting display device characterized by the above.

  The present invention includes a step of preparing a pair of substrates each having an electrode formed on one surface thereof, a step of arranging the pair of substrates so that the surfaces on which the electrodes are formed face each other, and a luminescent material in an ionic liquid. A step of dissolving, a step of adding a gelling material that gels the ionic liquid to the ionic liquid in which the luminescent material is dissolved, and the luminescent material is dissolved and the gelling material is added between a pair of substrates. And a step of forming a light emitting layer by injecting an ionic liquid.

  The present invention provides a step of preparing a pair of substrates each having an electrode formed on one surface, a step of dissolving a luminescent substance in an ionic liquid, and a gel containing the ionic liquid in an ionic liquid in which the luminescent substance is dissolved. A light emitting layer is formed by applying an ionic liquid in which a light emitting substance is dissolved and a gelling material is added to the surface of the substrate on which the electrode is formed, and adding a gelling material to be formed A method for manufacturing a light-emitting display device, comprising: a step; and a step of disposing the other substrate on the light-emitting layer so that a surface on which an electrode is formed faces the light-emitting layer.

  The present invention is a luminous body comprising an ionic liquid, a luminescent substance dissolved in the ionic liquid, and a gelling material that gels the ionic liquid, and is formed into a lump shape.

  The present invention is characterized by comprising: a support base having one electrode formed on the surface; a light emitter placed on the surface of the support base; and the other electrode in contact with the light emitter. The light emitting display device.

  In the present invention, the step of preparing a support base having one electrode formed on the surface, the step of dissolving the luminescent material in the ionic liquid, and the ionic liquid gelled into the ionic liquid in which the luminescent material is dissolved A step of adding a gelling material, a step of obtaining an illuminant by forming an ionic liquid to which the gelling material has been added into a lump, a step of placing the illuminant on the surface of a support substrate, And a step of bringing the other electrode into contact with the light-emitting display device.

  According to the present invention, since the light emitting layer is composed of an ionic liquid and a light emitting substance dissolved in the ionic liquid, the light emitting layer is formed without using a flammable organic solvent. Since the ionic liquid of the light emitting layer is flame retardant, it is relatively safe in handling compared to the case where a flammable organic solvent is used. In addition, the organic solvent is volatile because it is volatile, but according to the present invention, the ionic liquid in the light emitting layer is non-volatile because it is non-volatile. For this reason, it can prevent that a light emitting layer deteriorates and can maintain the stable performance, without the light emission characteristic of a light emitting layer falling. Further, when an organic solvent is used when forming the light emitting layer, it is necessary to dissolve the supporting salt in the organic solvent. However, according to the present invention, since the light emitting layer contains the ionic liquid, Furthermore, it is not necessary to dissolve the supporting salt. For this reason, the kind of material which comprises a light emitting layer can be decreased.

  Further, according to the present invention, since the light emitting layer is made of an ionic liquid, a light emitting substance dissolved in the ionic liquid, and a gelling material that gels the ionic liquid, The liquid can be gelled. For this reason, it is possible to prevent leakage of the ionic liquid in which the luminescent material is dissolved, and to maintain stable performance over a long period of time without deteriorating the luminescent properties of the luminescent layer.

  Furthermore, according to the present invention, since the luminescent material has an ionic liquid, a luminescent material dissolved in the ionic liquid, and a gelling material that gels the ionic liquid, the luminescent material is dissolved. The ionic liquid can be gelled and formed into a lump. For this reason, without sealing the ionic liquid in which the luminescent material is dissolved, it is possible to maintain the shape that is exposed to the outside and formed into a lump shape.

DESCRIPTION OF EXEMPLARY EMBODIMENTS First Embodiment Hereinafter, an embodiment of the invention will be described with reference to the drawings. Here, FIG. 1 to FIG. 3 are views showing a first embodiment of a light emitting display device according to the present invention. Among these, FIG. 1 is a diagram showing a cross-sectional structure of the light emitting display device according to the first embodiment of the present invention, and FIG. 2 shows a method for manufacturing the light emitting display device according to the first embodiment of the present invention. FIG. FIG. 3A is a diagram showing a state where no voltage is applied in the light emitting display device according to the first embodiment of the present invention, and FIG. 3B is a diagram illustrating the first embodiment of the present invention. In the light-emitting display device according to the embodiment, the light-emitting layer to which a voltage is applied emits light.

  First, the light-emitting display device 1 according to the present invention will be described with reference to FIG. Here, the light emitting display device 1 emits light when a voltage is applied, and is used as various displays.

  First, the light emitting display device 1 will be described with reference to FIG. The light emitting display device 1 includes a pair of substrates 3 on which electrodes 4 are formed on the surfaces facing each other, and a light emitting layer 5 sandwiched between the pair of substrates 3. Among these, the light emitting layer 5 includes an ionic liquid 6 and a luminescent material 7 dissolved in the ionic liquid 6. In addition, a pair of spacers 9 and 10 are provided between the pair of substrates 3 so as to surround the light emitting layer 5 and maintain a constant distance (gap) between the pair of electrodes 4. The distance between the pair of electrodes 4 may be 1 μm or more and 100 μm or less, and is particularly preferably set in the range of 5 μm to 30 μm. Further, out of the spacers 9 and 10 provided between the pair of substrates 3, one spacer 9 is formed with an injection hole 11 for injecting an ionic liquid 6 in which the luminescent material 7 is dissolved. The injection hole 11 is provided with a sealing material 12 that seals the injection hole 11 after the ionic liquid 6 in which the luminescent material 7 is dissolved is injected.

  Further, the liquid light-emitting element 2 of the light-emitting display device 1 is configured by the pair of electrodes 4 and the light-emitting layer 5 sandwiched between the pair of electrodes 4.

  As shown in FIG. 1, an AC power supply 13 that applies a voltage to the light emitting layer 5 is connected to each electrode 4 formed on the substrate 3.

  By the way, the ionic liquid 6 is also called a molten salt, and consists only of ions that maintain a liquid state at room temperature. Unlike the liquid electrolyte in which the supporting salt is dissolved in the organic solvent, the ionic liquid 6 has characteristics such as flame retardancy and non-volatility. In the light emitting layer 5 formed by dissolving the light emitting substance 7 in the ionic liquid 6, when the inside of the light emitting layer 5 is caused to undergo an electrochemical reaction, the voltage applied to the light emitting layer 5 can be kept low, and the oxidation / reduction can be performed at high speed. The reaction can take place.

  The material used as the ionic liquid 6 is preferably a highly polar material in order to dissolve various kinds of light-emitting substances 7 at a high concentration. For example, aliphatic, imidazolium, and pyridium materials can be used. . Of these, the 1-allyl-3-alkylimidazolium system can be particularly preferably used.

The material used as the light-emitting substance 7 is not particularly limited as long as it is an electrochemiluminescent material. For example, PVB (polyvinyl butyral), DPA (9,10-diphenylanthracene), perylene, RuCl ₆ , RuPF ₆ , Ru ( Ru (ruthenium) compounds and complexes such as bpy ₃ ) Cl ₂ and Ru (d ₈ -bpy ₃ ) PF ₆ can be preferably used. Moreover, there is no restriction | limiting in particular about the density | concentration of the luminescent substance 7, Although 10 wt% or less is desirable, Especially it can use suitably between 1 wt% and 5 wt%.

  The material used for the substrate 3 is not particularly limited as long as it is a transparent material for extracting light emitted from the light emitting substance 7 to the outside. For example, glass or a film can be used.

  The material used as the electrode 4 provided on the opposing surface of each substrate 3 is not particularly limited as long as it is a transparent material. For example, ITO (Indium Tin Oxide) or the like can be suitably used.

  Next, a method for manufacturing the light-emitting display device in this embodiment will be described.

  First, a pair of board | substrates 3 with which the electrode 4 was formed in each one surface are prepared. In this case, first, a pair of substrates 3 having a desired size and thickness is prepared, and electrodes 4 are formed on one surface of each substrate 3. Next, a pair of board | substrates 3 are arrange | positioned so that the surface in which the electrode 4 was formed opposes. Next, the pair of substrates 3 are bonded together via spacers 9 and 10. Thereby, empty cells 8 defined by the pair of substrates 3 and the spacers 9 and 10 provided between the pair of substrates 3 are formed.

  Next, the luminescent material 7 is dissolved in the ionic liquid 6. In this case, the luminescent material 7 is mixed with the ionic liquid 6 so as to have a desired concentration, and stirred at a predetermined temperature for a predetermined time. As a result, the luminescent material 7 is sufficiently dissolved in the ionic liquid 6.

  Thereafter, an ionic liquid 6 in which the luminescent material 7 is dissolved is injected between the pair of substrates 3. In this case, first, as shown in FIG. 2, a pair of substrates 3 bonded together via spacers 9 and 10 and having empty cells 8 formed therein are placed in an injection tank 16. Next, the inside of the empty cell 8 formed between the pair of substrates 3 together with the inside of the injection tank 16 is evacuated. Next, the ionic liquid 6 in which the luminescent material 7 is dissolved is dropped into the injection hole 11 of the spacer 9. Thereafter, the injection tank is decompressed. As a result, the ionic liquid 6 in which the luminescent material 7 is dissolved is vacuum-injected into the empty cell 8. During this time, the ionic liquid 6 in which the luminescent material 7 is dissolved has non-volatility, so that the ionic liquid 6 is not vaporized when vacuum injection is performed. For this reason, it can prevent that the light emitting layer 5 which consists of the ionic liquid 6 and the luminescent substance 7 deteriorates, and the light emission characteristic of the light emitting layer 5 falls. After the inside of the empty cell 8 is evacuated, the injection hole 11 of the spacer 9 is immersed in the ionic liquid 6 in which the luminescent material 7 is dissolved, and the ionic liquid in which the luminescent material 7 is dissolved in the empty cell 8. 6 may be injected by capillary action.

  Thereafter, the pair of substrates 3 bonded to each other via the spacers 9 and 10 are drawn out from the injection tank 16, and the injection holes 11 of the spacer 9 are sealed using the sealing material 12. In this way, the light emitting layer 5 is formed from the ionic liquid 6 and the light emitting substance 7 between the pair of substrates 3, and the light emitting display device 1 is obtained.

  Next, a usage pattern of the light emitting display device having such a configuration will be described.

  In the light emitting display device 1 according to the present embodiment, when the light emitting layer 5 is caused to emit light, an AC voltage is first applied to the light emitting layer 5 from the AC power supply 13 via the pair of electrodes 4. In this case, an electrochemical reduction reaction occurs in the vicinity of the electrode 4 serving as a cathode, and radical anions 14 are generated from the ionic liquid 6 and the luminescent material 7. On the other hand, an electrochemical oxidation reaction occurs in the vicinity of the electrode 4 serving as an anode, and radical cations 15 are generated from the ionic liquid 6 and the luminescent material 7.

  During this time, since an AC voltage is applied to each electrode 4, the reduction reaction and the oxidation reaction are alternately repeated in each electrode 4. That is, the radical anion 14 generated by the reduction reaction in the vicinity of one electrode 4 moves toward the opposite electrode 4. Next, the polarity of each electrode 4 is reversed, and radical cations 15 are generated in the vicinity of one electrode 4 by an oxidation reaction. During this time, the radical anion 14 that has moved from the vicinity of one electrode 4 toward the other electrode 4 returns to the one electrode 4. As a result, the radical anion 14 and the radical cation 15 collide. Next, a neutral molecule in a ground state and a neutral molecule in an excited state are generated from the colliding radical anion 14 and radical cation 15. Thereafter, the neutral molecule in the excited state is deactivated, and light is emitted from the neutral molecule. In this manner, the light emitting layer 5 emits light as shown in FIG. 3B from a state where no voltage is applied as shown in FIG. In FIG. 3B, the light emitting layer 5 emits light when a voltage of 30 Hz and ± 6 V is applied.

  Here, the light emission mechanism by which the light emitting layer 5 emits light can be described with reference to FIG. 8 showing the relationship between the voltage and the luminance when the thickness of the light emitting layer 5 is used as a parameter. That is, as shown in FIG. 8, even when the thickness of the light emitting layer 5 is changed to 2 μm, 25 μm, and 50 μm, the luminance does not change greatly. Accordingly, it can be seen that the radical anion 14 and the radical cation 15 collide with each other in the vicinity of each electrode 4 without moving between the electrodes 4 and the light emitting layer 5 emits light.

  As described above, according to the present embodiment, the light emitting layer 5 is composed of the ionic liquid 6 and the luminescent material 7 dissolved in the ionic liquid 6, and thus emits light without using a flammable organic solvent. Layer 5 is formed. Compared with the case where a flammable organic solvent is used, according to the present embodiment, the ionic liquid 6 included in the light emitting layer 5 is flame retardant, and is relatively safe in handling. In addition, the organic solvent is volatile because it is volatile, but according to the present embodiment, the ionic liquid 6 included in the light emitting layer 5 may be vaporized because it is nonvolatile. Absent. For this reason, it can prevent that the light emitting layer 5 deteriorates, and can maintain the stable performance, without the light emission characteristic of the light emitting layer 5 falling. Moreover, according to this Embodiment, when forming the light emitting layer 5, the ionic liquid 6 can be vacuum-injected. For this reason, the time for forming the light emitting layer 5 can be shortened as compared with the case of using a volatile organic solvent that is difficult to be injected by vacuum. Further, according to the present embodiment, since the ionic liquid 6 is used when forming the light emitting layer 5, it is not necessary to dissolve the supporting salt in the ionic liquid 6. For this reason, the kind of material which comprises the light emitting layer 5 can be decreased.

Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIG. Here, FIG. 4 is a schematic view showing a method for manufacturing the light emitting display device 1 according to the second embodiment of the present invention.

  The second embodiment shown in FIG. 4 is different from the method for manufacturing a light emitting display device only in that an ionic liquid in which a light emitting substance is dissolved is applied on one substrate, and the other configuration is shown in FIG. To substantially the same as the embodiment of the present invention shown in FIG. In FIG. 4, the same parts as those of the first embodiment shown in FIGS. 1 to 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

  According to the method for manufacturing a light-emitting display device in the present embodiment, first, a pair of substrates 3 each having an electrode 4 formed on one surface is prepared. In this case, first, a pair of substrates 3 having a desired size and thickness is prepared, and electrodes 4 are formed on one surface of each substrate 3. Next, spacers 17 and 18 are attached on the surface of one substrate 3 on which the electrode 4 is formed so as to surround a light emitting layer 25 described later.

  Next, the luminescent material 7 is dissolved in the ionic liquid 6. In this case, the luminescent material 7 is mixed with the ionic liquid 6 so as to have a desired concentration, and stirred at a predetermined temperature for a predetermined time. As a result, the luminescent material 7 is sufficiently dissolved in the ionic liquid 6.

  Next, the ionic liquid 6 in which the luminescent substance 7 is dissolved is applied on the surface of the substrate 3 on which the electrode 4 is formed, that is, dropped, to form the luminescent layer 5.

  Thereafter, the other substrate 3 is disposed on the light emitting layer 5 so that the surface on which the electrode 4 is formed faces the light emitting layer 5 side. In this way, the pair of substrates 3 are bonded together so as to face each other via the spacers 17 and 18, and the light emitting layer 5 is formed from the ionic liquid 6 and the light emitting substance 7 between the pair of substrates 3. Device 1 is obtained.

  According to the present embodiment, the light emitting layer 5 is composed of the ionic liquid 6 and the light emitting substance 7 dissolved in the ionic liquid 6, so that the light emitting layer 5 can be formed without using a volatile organic solvent. It is formed. Since the organic solvent has volatility, it is easily vaporized, and it is difficult to apply the organic solvent on the surface on which the electrode 4 of the one substrate 3 is formed. Since the ionic liquid 6 included in the light emitting layer 5 is non-volatile, it can be applied on the surface of the substrate 3 on which the electrode 4 is formed. For this reason, the time for which the light emitting layer 5 is formed can be shortened.

Third Embodiment Next, a third embodiment of the present invention will be described with reference to FIG. Here, FIG. 6 is a diagram showing a cross-sectional configuration of the light-emitting display device according to the third embodiment of the present invention.

  In the third embodiment shown in FIG. 6, a gelling material that gels the ionic liquid is added to the ionic liquid in which the luminescent substance is dissolved, and other configurations are shown in FIGS. This is substantially the same as the first embodiment shown or the second embodiment shown in FIG. In FIG. 6, the same parts as those of the first embodiment shown in FIGS. 1 to 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 6, the light emitting layer 5 includes an ionic liquid 6, a light emitting substance 7 dissolved in the ionic liquid 6, and a gelling material 30 that gels the ionic liquid 6.

  In the present embodiment, after the luminescent substance 7 is dissolved in the ionic liquid 6, the gelling material 30 that gels the ionic liquid 6 is added to the ionic liquid 6 in which the luminescent substance 7 is dissolved, and mixed for a predetermined time. The Thereby, the ionic liquid 6 in which the luminescent substance 7 is dissolved can be gelled.

  Here, the gelation means a state in which the ionic liquid 6 has lost its fluidity, and it is preferable to use silica nano-sized fine particles or titanium oxide nano-sized fine particles as the gelled material.

  Further, the amount of the gelling material added is desirably 1 wt% to 15 wt%, and particularly preferably 3 wt% to 7 wt%.

  According to the present embodiment, by adding the gelling material 30 to the ionic liquid 6 in which the luminescent substance 7 is dissolved, the ionic liquid 6 in which the luminescent substance 7 is dissolved can be gelled. For this reason, it is possible to prevent the ionic liquid 6 in which the luminescent material 7 is dissolved from leaking from the empty cell 8, and to maintain stable performance over a long period of time without deteriorating the luminescent properties of the luminescent layer 5. it can.

  As already described with reference to FIG. 8, the radical anion 14 and the radical cation 15 collide with each other in the vicinity of each electrode 4 and emit light without moving between the electrodes 4. Thereby, also in the light emitting layer 5 made of the gelled ionic liquid 6 as in the present embodiment, the radical anion 14 and the radical cation 15 collide with each other in the vicinity of each electrode 4 to cause the light emitting layer 5 to emit light. be able to.

Fourth Embodiment Next, a fourth embodiment of the present invention will be described with reference to FIG. Here, FIG. 9 is a diagram showing a light-emitting display device including a light-emitting body according to the fourth embodiment of the present invention.

  In the fourth embodiment shown in FIG. 9, a gelling material that gels the ionic liquid is added to the ionic liquid in which the luminescent substance is dissolved, and the ionic liquid is molded into a lump. Other configurations are substantially the same as those of the third embodiment shown in FIG. In FIG. 9, the same parts as those of the third embodiment shown in FIG.

  A light-emitting display device 45 shown in FIG. 9 has a substrate (support base material) 41 on which one electrode 42 is formed on the surface, is placed on the surface of the substrate 41, and is dissolved in the ionic liquid 6 and the ionic liquid 6. The light-emitting substance 7 and the gelling material 30 that gels the ionic liquid 6 are provided, and the light-emitting body 40 is formed into a lump shape.

  A wire (the other electrode) 43 is inserted into the light emitter 40 from above the light emitter 40. In this case, the light emitter 40 and the portion of the wire 43 inserted into the light emitter 40 are in contact. The wire 43 has a wire diameter of 1 mm, and the distance x between the tip of the wire 43 and the upper surface of the electrode 42 is 2 mm as shown in FIG. Further, an AC power supply 44 that applies an AC voltage to the light emitter 40 is connected between the electrode 42 and the wire 43.

  Moreover, as a material used for the board | substrate 41, glass or a film can be used, for example. In the case where light emitted from the light emitter 40 is taken out from above or from the side of the light emitter 40, the material used for the substrate 41 is not limited to a transparent material.

  As a material used for the electrode 42 and the wire 43 provided on the surface of the substrate 41, ITO can be used. However, when the light emitted from the light emitter 40 is taken out from above or from the side of the light emitter 40, the material used for the electrode 42 and the wire 43 is not limited to a transparent material. In this case, gold (Au), silver (Ag), aluminum (Al), tin (Sn), bismuth (Bi), or the like can be used as a material used for the electrode 42 and the wire 43, and indium which is a rare metal is used. The light emitter 40 can be made to emit light using a relatively inexpensive material without using ITO containing.

  When manufacturing the light emitting display device shown in FIG. 9, first, a substrate 41 having one electrode 42 formed on the surface is prepared.

  Next, a gelling material 30 for gelling the ionic liquid 6 is added to the ionic liquid 6 in which the luminescent substance 7 is dissolved and mixed for a predetermined time, and the ionic liquid 6 in which the luminescent substance 7 is dissolved is gelled. The Thereafter, the gelled ionic liquid 6 is formed into a lump shape. In this way, the light emitter 40 is obtained.

  Next, the light emitting body 40 formed in the lump shape is placed on the surface of the substrate 41. Next, the wire 43 is inserted into the light emitter 40 from the outside of the light emitter 40. In this way, the light emitting display device 45 shown in FIG. 9 is obtained.

  A method of causing the light emitting body 40 to emit light in the light emitting display device 45 thus obtained will be described. First, an AC voltage is applied from the AC power supply 44 to the light emitter 40 via the electrode 42 and the wire 43. In this case, for example, an electrochemical reduction reaction occurs in the vicinity of the electrode 42 serving as a cathode, and radical anions 14 are generated from the ionic liquid 6 and the luminescent material 7. On the other hand, an electrochemical oxidation reaction takes place in the vicinity of the portion of the wire 43 serving as the anode inserted into the light emitter 40, and radical cations 15 are generated from the ionic liquid 6 and the light emitting substance 7.

  While an AC voltage is applied to the light emitter 40, an AC voltage is applied to the electrode 42 and the wire 43, so that the reduction reaction and the oxidation reaction are alternately repeated in the electrode 42 and the wire 43. That is, for example, the radical anion 14 generated by the reduction reaction in the vicinity of the electrode 42 moves toward a portion of the wire 43 inserted into the light emitter 40. Next, the polarities of the electrode 42 and the wire 43 are reversed, and the radical cation 15 is generated near the electrode 42 by an oxidation reaction. During this time, the radical anion 14 that has moved from the vicinity of the electrode 42 toward the portion of the wire 43 inserted into the light emitter 40 returns to the electrode 42. As a result, the radical anion 14 and the radical cation 15 collide. Next, a neutral molecule in a ground state and a neutral molecule in an excited state are generated from the colliding radical anion 14 and radical cation 15. Thereafter, the neutral molecule in the excited state is deactivated, and light is emitted from the neutral molecule.

  In the same manner as the light emission mechanism in the vicinity of the electrode 42, the generated radical anion 14 and the radical cation 15 collide with each other in the vicinity of the portion of the wire 43 inserted into the light emitter 40, and excited molecules Is generated and emits light.

  Here, even when the light emitter 40 shown in FIG. 9 emits light, the radical anion 14 and the radical cation 15 collide near the electrode 42 and in the vicinity of the portion of the wire 43 inserted into the light emitter 40 to emit light. To do. For this reason, even when the distance x between the electrode 42 and the tip of the wire 43 is relatively long, the light emitter 40 can emit light.

  Thus, according to the present embodiment, the luminous body 40 has the ionic liquid 6, the luminescent substance 7 dissolved in the ionic liquid 6, and the gelling material 30 that gels the ionic liquid 6. Therefore, the ionic liquid 6 in which the luminescent substance 7 is dissolved can be gelled and formed into a lump shape. For this reason, without sealing the ionic liquid 6 in which the luminescent substance 7 is dissolved, it is possible to maintain the shape that is exposed to the outside and formed into a lump shape.

  In addition, according to the present embodiment, the luminous body 40 formed in a lump shape is placed on the substrate 41 having the electrode 42 formed on the surface, and the wire 43 is inserted into the luminous body 40 from above the luminous body 40. Thus, the light emitter 40 can emit light by applying an alternating voltage to the light emitter 40 via the electrode 42 and the wire 43. In this case, since the light emitter 40 is exposed to the outside, the light emitted from the light emitter 40 can be easily and reliably extracted to the outside.

  In the present embodiment, an example is shown in which the wire 43 is inserted into the light emitter 40 from above the light emitter 40. However, the present invention is not limited to this, and the light emitter 40 can be made to emit light by being inserted into the light emitter 40 from the side of the light emitter 40. Further, the light emitter 40 can be caused to emit light by contacting the surface or side surface of the light emitter 40 without inserting the wire 43 into the light emitter 40. Further, the other electrode corresponding to one electrode 42 is not limited to the wire 43, and electrodes having various shapes can also be used.

Example 1
As an example of the present invention, the light-emitting display device 1 of FIG. 1 was manufactured by the following method.

  First, two glass plates 3 (size 10 mm × 10 mm) serving as a substrate provided with an electrode 4 made of ITO having a thickness of 150 nm in advance are prepared, and these glass plates 3 are washed with a neutral detergent, Furthermore, it was ultrasonically cleaned and then dried. Next, these two glass plates 3 are subjected to UV cleaning, and are bonded so as to face each other through 25 μm film spacers 9 and 10 so that the surfaces of the electrodes 4 face each other. Formed.

Next, to the N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium tetrafluoroborate which is the ionic liquid 6, Ru (bpy ₃ ) Cl ₂ as the luminescent material 7 is added to 2.5 wt%. % And mixed at 65 ° C. and 500 rpm for 3 hours to sufficiently dissolve Ru (bpy ₃ ) Cl ₂ as the luminescent material 7 to produce a luminescent solution.

  Next, a luminescent solution was injected into the empty cell 8 between the pair of glass plates 3 described above by capillary action, and a UV adhesive 12 serving as a sealing material was applied to the injection hole 11 to seal the injection hole 11. In this way, the light emitting layer 5 is formed from the light emitting solution between the pair of glass plates 3, and the light emitting display device 1 is obtained.

Thereafter, an AC voltage of 30 Hz and ± 6 V was applied to the light emitting layer 5 obtained in this example. As a result, red light emission having a luminance of 50 cd / m ² could be obtained.

Example 2
The light emitting display device 1 in this example is different only in that the size of the glass plate 3 is 500 mm × 500 mm and the point where the luminescent solution is vacuum-injected into the empty cell 8 between the pair of glass plates 3, Other configurations are substantially the same as those of the first embodiment. In addition, when the luminescent solution is vacuum-injected into the empty cell 8, the time can be shortened compared with the case where it is injected by capillary action.

An AC voltage of 30 Hz and ± 6 V was applied to the light emitting layer 5 obtained in this example. As a result, red light emission having a luminance of 50 cd / m ² was obtained. Further, the characteristics of the light emitting layer 5 were not deteriorated.

Example 3
The light emitting display device 1 in this example is different only in that the ionic liquid 6 is 1-allyl-3-butylimidazolium bis (trifluoromethanesulfonyl) imide (abbreviation: ABImTFSI). This is substantially the same as the second embodiment.

ABImTFSI is more polar than N, N-diethyl-N-methyl-N- (2-methoxyethyl) ammonium tetrafluoroborate. For this reason, 5 wt% of Ru (bpy ₃ ) Cl ₂ could be dissolved in the ionic liquid 6.

An AC voltage of 30 Hz and ± 6 V was applied to the light emitting layer 5 obtained in this example. As a result, red light emission having a luminance of 100 cd / m ² could be obtained.

Example 4
The light-emitting display device 1 in this example is different from the light-emitting material 7 only in that the light-emitting substance 7 is Ru (d ₈ -bpy ₃ ) PF _6, and other configurations are substantially the same as those in Example 3.

An AC voltage of 30 Hz and ± 6 V was applied to the light emitting layer 5 obtained in this example. As a result, red light emission having a luminance of 200 cd / m ² could be obtained.

Example 5
The light-emitting display device 1 in this example is different only in that the light-emitting substance 7 is DPA (9,10-diphenylanthracene), and other configurations are substantially the same as those in Example 4.

An AC voltage of 30 Hz and ± 10 V was applied to the light emitting layer 5 obtained in this example. As a result, green light emission having a luminance of 30 cd / m ² could be obtained.

Example 6
The light emitting display device 1 in this embodiment is different only in that the light emitting material 7 is perylene, and other configurations are substantially the same as those in the fifth embodiment.

An AC voltage of 30 Hz and ± 10 V was applied to the light emitting layer 5 obtained in this example. As a result, blue light emission having a luminance of ²⁰ cd / m ² could be obtained.

Example 7
The light-emitting display device 1 in this example is different only in that a gelling material (silica fine particles (Aerosil 200 manufactured by Nippon Aerosil Co., Ltd.)) 30 is added to the light-emitting solution, and other configurations are substantially the same as those in Example 3. It is.

In this example, a luminescent solution in which 2 wt% of Ru (bpy ₃ ) Cl ₂ as the luminescent material 7 was mixed with ABImTFSI as the ionic liquid 6 was produced. Further, silica fine particles were added to the luminescent solution and mixed for a predetermined time.

  An alternating voltage was applied to the light emitting layer 5 obtained in this example. At this time, a light emitting solution to which silica fine particles are not added and each light emitting solution to which 3 wt%, 4 wt%, 7 wt%, and 10 wt% silica fine particles are added are generated, and the light emitting layer 5 is formed on each light emitting solution. Then, an alternating voltage was applied to each light emitting layer 5. Thereby, the characteristic which shows the relationship between an alternating voltage and a brightness | luminance as shown in FIG. 7 was obtained by using the quantity of the silica fine particle added to a luminescent solution as a parameter.

  As shown in FIG. 7, it can be seen that the luminance of the luminescent layer 5 made of the luminescent solution with silica fine particles is improved compared to the luminescent layer 5 made of the luminescent solution with no silica fine particles added. . When silica fine particles are added in this manner, the multiple scattering effect due to the silica fine particles works, so that the luminance is improved.

Example 8
The light emitting display device 45 in this embodiment is different from the light emitting device of Example 7 only in that a voltage is applied to a light emitting body formed into a lump by gelling a light emitting solution.

In this example, first, a luminescent solution in which 2 wt% of Ru (bpy ₃ ) Cl ₂ as the luminescent material 7 was mixed with ABImTFSI as the ionic liquid 6 was produced. Next, silica fine particles were added to the luminescent solution and mixed for a predetermined time to gel the luminescent solution, and the light-emitting body 40 was formed by forming the gelated luminescent solution into a lump.

  Next, the light emitter 40 was placed on the surface of the substrate 41 on which the electrode 42 was formed, and the wire 43 was inserted into the light emitter 40 from above the light emitter 40. The wire 43 had a wire diameter of 1 mm, and the distance x (see FIG. 9) between the tip of the wire 43 and the upper surface of the electrode 42 was 2 mm.

  After that, an AC voltage of 60 Hz and ± 3 V was applied to the luminous body 40 obtained in this example through the electrode 42 and the wire 43. As a result, the light emitter 40 could emit light.

FIG. 1 is a diagram showing a cross-sectional structure of a light-emitting display device according to a first embodiment of the present invention. FIG. 2 is a schematic view showing a method for manufacturing the light-emitting display device according to the first embodiment of the present invention. FIG. 3A is a diagram showing a state where no voltage is applied in the light emitting display device according to the first embodiment of the present invention, and FIG. 3B is a diagram illustrating the first embodiment of the present invention. In the light emitting display device according to the embodiment, it is a diagram showing a state in which a light emitting layer to which a voltage is applied emits light. FIG. 4 is a schematic view showing a method for manufacturing the light emitting display device according to the second embodiment of the present invention. FIG. 5 shows a cross-sectional structure of a conventional light emitting display device. FIG. 6 is a diagram showing a cross-sectional structure of a light-emitting display device according to the third embodiment of the present invention. FIG. 7 is a diagram illustrating the relationship between voltage and luminance. FIG. 8 is a diagram illustrating a relationship between voltage and luminance when the thickness of the light emitting layer is used as a parameter. FIG. 9 is a diagram showing a light-emitting display device including a light-emitting body in the fourth embodiment of the present invention.

DESCRIPTION OF SYMBOLS 1 Light emitting display device 2 Liquid light emitting element 3 Substrate 4 Electrode 5 Light emitting layer 6 Ionic liquid 7 Luminescent substance 8 Luminescent liquid 9 Spacer 10 Spacer 11 Injection hole 12 Sealing material 13 AC power supply 14 Radical anion 15 Radical cation 21 Light emitting display device 23 Substrate 24 electrode 25 light emitting layer 26 organic solvent 27 support salt 28 light emitting material 30 gelling material 40 light emitter 41 substrate 42 electrode 43 wire 44 power supply 45 light emitting display device

Claims (4)

A pair of substrates each having electrodes formed on opposite surfaces;
A light emitting layer sandwiched between a pair of substrates,
Light emitting layer, possess an ionic liquid, and dissolved luminescent substance to the ionic liquid, a gelling material to gel the ionic liquid,
The light-emitting display device , wherein the gelling material is composed of silica nano-sized fine particles or titanium oxide nano-sized fine particles . The light emitting display device according to claim 1, wherein the light emitting layer emits light when an alternating voltage is applied thereto. Ionic liquids are aliphatic, imidazolium, light-emitting display device according to claim 1 or 2, characterized in that it comprises one of the materials of pyridium system. The luminescent material includes any one of a ruthenium compound / complex, PVB (polyvinyl butyral), DPA (9,10-diphenylanthracene), and perylene, according to any one of claims 1 to 3 . Luminescent display device.

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