JP2006019251A - Lighting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lighting system capable of suppressing variations in brightness in a light-emitting region when the lighting system is formed to have a large area. <P>SOLUTION: One embodiment of the present invention is a light-emitting device comprising a first electrode, a second electrode, a layer containing a light-emitting substance formed between the first electrode and the second electrode, an insulating layer formed in a grid form and containing a fluorescent agent, and wiring formed over the insulating layer. The insulating layer and the wiring are covered with the first electrode so that the first electrode and the wiring are in contact with each other. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a lighting device using a light emitting element.

  The light-emitting element is a self-luminous element and has been attempted to be used as a lighting device. The light emitting element is a surface light emitter, and an illumination device closer to natural light can be obtained by using it as illumination.

  The light-emitting element includes a layer containing a light-emitting substance from which luminescence can be obtained by applying an electric field, an anode, and a cathode. Light emission can be obtained by combining holes injected from the anode and electrons injected from the cathode in the electroluminescent layer. The luminescence obtained from the electroluminescent layer includes light emission (fluorescence) when returning from the singlet excited state to the ground state and light emission (phosphorescence) when returning from the triplet excited state to the ground state.

  In a light emitting device using such a light emitting element, an electrode in a direction in which light is emitted needs to be transparent. However, many transparent conductive films generally used as transparent electrodes have a relatively high resistivity, and a voltage drop occurs at a portion away from the current supply terminal. In particular, the illumination device often emits light with the same luminance on the entire surface, and this luminance variation (non-uniformity) becomes more conspicuous.

However, when the area of the illuminating device is increased, the luminance is reduced in a portion where current is difficult to flow. That is, the luminance varies within the light emitting region of the lighting device. In general, an ITO electrode used as an anode has a higher electric resistance than a metal such as Al used for a cathode. For this reason, a voltage drop occurs at a portion away from the current supply terminal, and the luminance is lowered. In order to solve this problem, a structure in which an auxiliary electrode having an electric resistance lower than that of the anode is provided in at least a part of the anode has been reported (see Patent Document 1).
JP 2004-134282 A

  In Patent Document 1, auxiliary electrodes are provided on the long side or the short side of the light emitting element. However, when the area of the lighting device is increased, luminance decreases in a portion away from the auxiliary electrode (for example, the central portion of the lighting device). Will happen. However, if the auxiliary electrode is provided on the entire surface of the anode in the structure of Patent Document 1, light emitted from the light emitting layer cannot be emitted to the outside, and therefore the auxiliary electrode can be provided only in part.

  In addition, since the illuminating device often emits light with the same luminance on the entire surface, the variation in luminance becomes more conspicuous.

  In view of the above problems, the present invention provides an illumination device that can suppress variation in luminance within a light emitting region (that is, good uniformity in luminance) when the illumination device is increased in area. Is an issue.

  In the lighting device of the present invention, a layer containing a light-emitting substance is formed between the first electrode and the second electrode, and an opening formed in the second electrode and the layer containing the light-emitting substance is provided. And a third electrode connected to the first electrode.

  That is, a layer containing a light-emitting substance and a second electrode are provided between the first electrode and the auxiliary electrode, and the auxiliary electrode is opposite to the first electrode with the second electrode interposed therebetween. The first electrode and the auxiliary electrode are electrically connected through an opening formed in the second electrode and the layer containing a light-emitting substance. Note that the first electrode and the second electrode, and the second electrode and the auxiliary electrode need to be electrically insulated.

  More specifically, a layer containing a light emitting substance in which a first opening is formed on a first electrode made of a transparent conductive film, and a second electrode in which a second opening is formed, The first opening and the second opening are arranged so as to overlap with each other, provided on the second electrode, and the first opening, the second opening, and the second opening An insulating layer that covers the side wall and has a third opening that exposes the first electrode, is provided on the insulating layer, and is in contact with the first electrode through the first to third openings. And a third electrode.

  In the above structure, a plurality of openings are provided in the light emitting region of the lighting device.

  In the above structure, light emitted from the layer containing a light-emitting substance is emitted from the first electrode side. That is, the first electrode has translucency and is formed of a transparent conductive film. Specifically, indium tin oxide (hereinafter referred to as ITO), indium tin oxide containing silicon, indium oxide containing 2 to 20% zinc oxide (ZnO), or the like can be given.

  Note that it is preferable to use a material having a low resistivity as the auxiliary electrode. By using a material having a low resistivity, the voltage drop of the first electrode can be reduced.

  In the above structure, the layer containing a light-emitting substance may have a structure in which a plurality of layers containing a light-emitting substance are stacked.

  In the above configuration, since light emission is not blocked by the auxiliary electrode, there is no loss of light emission except at the connection portion between the auxiliary electrode and the first electrode. Therefore, the material, film thickness, and formation location of the auxiliary electrode can be freely set.

  Further, if the area of the connection portion between the auxiliary electrode and the first electrode is made sufficiently small, the presence of the auxiliary electrode can be almost ignored even when viewed from the light emission surface. Therefore, a plurality of openings can be provided in the light emitting region of the lighting device.

  According to one aspect of the present invention, a first electrode, a second electrode, a layer containing a light-emitting substance provided between the first electrode and the second electrode, a lattice shape over a substrate, A light-emitting device having an insulating layer containing a fluorescent substance and a wiring provided on the insulating layer. Here, the insulating layer and the wiring are covered with the first electrode so that the first electrode and the wiring are in contact with each other.

  By using the present invention, a lighting device with reduced variation in luminance can be obtained. Further, since the auxiliary electrode is not arranged in the light emission direction, the loss of light by the auxiliary electrode is small, and the material, film thickness, and formation location of the auxiliary electrode can be freely set.

  Embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it is easily understood by those skilled in the art that modes and details can be variously changed without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the description of the embodiments below.

(Embodiment 1)
The structure of the lighting device of the present invention will be described with reference to FIG. The illumination device shown in FIG. 1 is a bottom emission type illumination device that emits light from the substrate side. 1B is a top view of the light-emitting region of the lighting device of the present invention, and FIG. 1A is a cross-sectional view in the vicinity of the opening of the light-emitting region (AA ′ in FIG. 1B).

  In FIG. 1, a substrate having a light-transmitting property is used as the substrate 101. Specifically, a light-transmitting material such as glass, plastic, polyester, or acrylic resin can be used. The substrate 101 may have flexibility.

  A transparent conductive film is formed over the substrate 101 as the first electrode 102. Examples of the transparent conductive film include indium tin oxide (hereinafter referred to as ITO), indium tin oxide containing silicon, indium oxide containing 2 to 20% zinc oxide (ZnO), and the like.

A layer 103 containing a light-emitting substance is formed over the first electrode 102. A known material can be used for the layer 103 containing a light-emitting substance, and either a low molecular material or a high molecular material can be used. Note that the material for forming a layer containing a light-emitting substance includes not only an organic compound material but also a structure including an inorganic compound in part. The layer containing a light-emitting substance is configured by appropriately combining a hole injection layer, a hole transport layer, a hole blocking layer (hole blocking layer), a light emitting layer, an electron transport layer, an electron injection layer, and the like. You may comprise by a layer and it is good also as a structure which laminated | stacked the several layer. FIG. 11 illustrates an example of a structure in which a layer containing a light-emitting substance includes a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, and an electron injection layer. In FIG. 11, a first electrode (anode) 1101, a layer 1102 containing a light emitting substance, and a second electrode (cathode) 1103 are formed over a substrate 1100. A layer 1111, a hole transport layer 1112, a light emitting layer 1113, an electron transport layer 1114, and an electron injection layer 1115 are provided. Note that in the lighting device of the present invention, the layer containing a light-emitting substance is not limited to the structure shown in FIG. Specific materials used for the hole injection layer, the hole transport layer, the light emitting layer, the electron transport layer, and the electron injection layer are shown below.

As the hole-injecting material for forming the hole-injecting layer, a porphyrin-based compound is effective as long as it is an organic compound, and phthalocyanine (hereinafter referred to as H ₂ -Pc), copper phthalocyanine (hereinafter referred to as Cu-Pc). Or the like can be used. In addition, there is a material in which a conductive polymer compound is chemically doped, and polyethylenedioxythiophene (hereinafter referred to as PEDOT) doped with polystyrene sulfonic acid (hereinafter referred to as PSS) can also be used. Further, a benzoxazole derivative and any one or a plurality of materials of TCQn, FeCl ₃ , C ₆₀ or F ₄ TCNQ may be included.

  As the hole transporting material for forming the hole transport layer, an aromatic amine compound (that is, a compound having a benzene ring-nitrogen bond) is preferable. Examples of widely used materials include N, N′-bis (3-methylphenyl) -N, N′-diphenyl- [1,1′-biphenyl] -4,4′-diamine (hereinafter referred to as TPD). 4,4′-bis [N- (1-naphthyl) -N-phenyl-amino] -biphenyl (hereinafter referred to as α-NPD) or 4,4′-4 ′, 4 ′ '-Tris (N-carbazolyl) -triphenylamine (hereinafter referred to as TCTA), 4,4', 4 ''-tris (N, N-diphenyl-amino) -triphenylamine (hereinafter referred to as TDATA) , 4,4 ′, 4 ″ -tris [N- (3-methylphenyl) -N-phenyl-amino] -triphenylamine (hereinafter referred to as MTDATA) and the like. .

Specific examples of the light-emitting material for forming the light-emitting layer include tris (8-quinolinolato) aluminum (hereinafter referred to as Alq ₃ ), tris (4-methyl-8-quinolinolato) aluminum (hereinafter referred to as Almq _3). ), Bis (10-hydroxybenzo [h] -quinolinato) beryllium (hereinafter referred to as BeBq ₂ ), bis (2-methyl-8-quinolinolato) -4-phenylphenolato-aluminum (hereinafter referred to as BAlq). ), Bis [2- (2-hydroxyphenyl) -benzoxazolate] zinc (hereinafter referred to as Zn (BOX) ₂ ), bis [2- (2-hydroxyphenyl) -benzothiazolate] zinc (hereinafter referred to as Zn ( In addition to metal complexes such as BTZ) ₂ , various fluorescent dyes are effective.

When a light emitting layer is formed in combination with a guest material, quinacridone, diethylquinacridone (hereinafter referred to as DEQD), dimethylquinacridone (hereinafter referred to as DMQD), rubrene, perylene, coumarin, coumarin 545T (hereinafter referred to as C545T). DPT, Co-6, PMDFB, BTX, ABTX, DCM, DCJT, tris (2-phenylpyridine) iridium (hereinafter referred to as Ir (ppy) ₃ ), 2, 3, 7, 8, A triplet light-emitting material (phosphorescent material) such as 12,13,17,18-octaethyl-21H, 23H-porphyrin-platinum (hereinafter referred to as PtOEP) can be used as a guest material.

Examples of the electron transporting material that can be used for the electron transporting layer include Alq ₃ , Almq ₃ , bis (2-methyl-8-quinolinolato) -4-phenylphenolato-aluminum (abbreviation: BAlq), and Gaq. ₃ , metal complexes such as bis (2-methyl-8-quinolinolato) -4-phenylphenolato-gallium (abbreviation: BGaq), BeBq ₂ , Zn (BOX) ₂ , Zn (BTZ) ₂ , 2- ( 4-biphenylyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole (abbreviation: PBD) and 1,3-bis [5- (p-tert-butylphenyl) -1 , 3,4-oxadiazol-2-yl] benzene (abbreviation: OXD-7), 3- (4-tert-butylphenyl) -4-phenyl-5- (4-biphenylyl) -1,2 4-triazole (abbreviation: TAZ), 3- (4-tert-butylphenyl) -4- (4-ethylphenyl) -5- (4-biphenylyl) -1,2,4-triazole (abbreviation: p-EtTAZ) ), Bathophenanthroline (abbreviation: BPhen), bathocuproin (abbreviation: BCP), and the like.

Specific examples of the electron injecting material for forming the electron injection layer include alkali metal halides such as LiF and CsF, alkaline earth halides such as CaF ₂ , and alkali metal oxides such as Li ₂ O. Such an insulating ultra-thin film is often used. Alkali metal complexes such as lithium acetylacetonate (abbreviation: Li (acac)) and 8-quinolinolato-lithium (abbreviation: Liq) are also effective. Moreover, you may make it contain a benzoxazole derivative and any one or more materials of an alkali metal, an alkaline-earth metal, or a transition metal.

Note that the layer 103 containing a light-emitting substance may have a structure in which layers containing a plurality of light-emitting substances are stacked. FIG. 12 illustrates an example of a structure in which a plurality of layers containing a light-emitting substance are stacked. 12A and 12B, the substrate 1200 has a structure in which a first electrode 1201, a first layer 1202 containing a light-emitting substance, a charge generation layer 1203, a second layer 1204 containing a light-emitting substance, and a second electrode are stacked. is doing. The charge generation layer 1203 has a role of injecting carriers and needs to be a highly light-transmitting material. Note that FIG. 12 illustrates a structure in which two layers containing a light-emitting substance are stacked; however, the structure is not limited thereto, and a structure in which three or more layers containing a light-emitting substance are stacked may be used. In FIG. 12, the substrate-side electrode is the first electrode, but the substrate-side electrode may be the second electrode.

  With a structure in which layers containing a light-emitting substance are stacked, luminance is improved only by stacking even with the same current. In particular, a structure in which layers containing a light-emitting substance are stacked is suitable for lighting applications that require high luminance. In addition, in the case of a structure in which a plurality of layers containing light-emitting substances are stacked, a structure in which layers containing light-emitting substances made of the same material are stacked may be used, or layers containing light-emitting substances made of different materials It is good also as a structure which laminated | stacked.

For example, a layer containing a light-emitting substance formed using a material that emits red (R), green (G), and blue (B) light can be stacked to obtain white light emission as a whole. Such materials that emit red (R), green (G), and blue (B) light may be formed by an evaporation method using an evaporation mask, a droplet discharge method (also referred to as an inkjet method), or the like. . Specifically, CuPc or PEDOT can be used as the hole injection layer, α-NPD as the hole transport layer, BCP or Alq ₃ as the electron transport layer, and BCP: Li or CaF ₂ as the electron injection layer. In addition, for example, the light emitting layer has a dopant corresponding to each of the emission colors of R, G, and B (in the case of R, D
Alq ₃ doped with CM or the like, DMQD or the like in the case of G) may be used. In addition, when obtaining white light emission, it is good also as a structure which laminated | stacked the light emission material of not only the above-mentioned three colors light emitting material but laminated | stacked two colors. For example, white light emission can be obtained by stacking materials that emit blue and yellow light.

  Note that the structure of the layer containing a light-emitting substance is not limited to the above stacked structure. For example, the layer containing a light-emitting substance may be any of a single layer type, a stacked type, and a mixed type having no layer interface. Alternatively, a fluorescent material, a phosphorescent material, or a combination thereof can be used. For example, a phosphorescent material can be used as a material that emits red (R) light, and a fluorescent material can be used as a material that emits green (G) or blue (B) light. Furthermore, any of an organic material including a low molecular material, a high molecular material, and a medium molecular material, an inorganic material typified by molybdenum oxide having excellent electron injection properties, and a composite material of an organic material and an inorganic material may be used.

  The lighting device of the present invention is not limited to white, and may obtain light of a desired color. Further, a color filter, a color conversion layer, or a color filter and a color conversion layer may be provided separately.

A second electrode 104 is formed over the layer 103 containing a light-emitting substance. A known material can be used for the second electrode 104. When the second electrode 104 is a cathode, it is preferable to use a conductive material having a low work function. Specifically, alkaline metals such as Li and Cs, and alkaline earth metals such as Mg, Ca, and Sr are used. , And alloys containing these (Mg: Ag, Al: Li, etc.), and rare earth metals such as Yb and Er can also be used. Further, LiF, CsF, in the case of using an electron injecting layer such as CaF _2, Li ₂ O, may be used usual conductive thin film such as aluminum. In the case where the second electrode 104 is an anode, a conductive material having a high work function is preferably used. Specifically, in addition to a single layer film such as TiN, ZrN, Ti, W, Ni, Pt, Cr, etc., a laminate of a film made of titanium nitride and a film containing aluminum as a main component, a titanium nitride film and aluminum are mainly used. A three-layer structure of a component film and a titanium nitride film can be used. Or the method of laminating | stacking a transparent conductive film on reflective electrodes, such as Ti and Al, may be used.

  An insulating film 105 is formed so as to cover the second electrode 104 and the layer 103 containing a light-emitting substance. By this insulating film 105, the first electrode 102 and the second electrode 104, and the second electrode 104 and the auxiliary electrode 106 are electrically insulated from each other. Note that the insulating film 105 may have a function as a protective film that prevents permeation of a substance that causes deterioration of a layer containing a light-emitting substance such as moisture or oxygen.

  A part of the insulating film 105 has an opening 107, and the first electrode 102 and the auxiliary electrode 106 are electrically connected in the opening 107. As the auxiliary electrode 106, a material having a low resistivity is preferably used. Specifically, a material such as aluminum, copper, or silver can be used. The diameter of the opening is 10 to 500 μm, preferably 50 to 200 μm.

A plurality of openings 107 are provided in the light emitting region 108. The auxiliary electrode 106 is electrically connected to the first electrode 102 through the opening 107, so that the influence of a voltage drop due to the relatively high resistance of the transparent conductive film can be reduced. That is, the auxiliary electrode 106 is electrically connected to the first electrode 102 through the plurality of openings 107 provided in the light emitting region 108, thereby substantially reducing the resistance of the first electrode 102. ing. Thereby, it is possible to reduce a variation in luminance in which a portion away from the current supply terminal becomes dark. If the size of the opening is made sufficiently small, the presence of the auxiliary electrode can be almost ignored when the illumination device is viewed from the light emission direction, that is, from the translucent substrate side. Further, since the auxiliary electrode is not arranged in the light emission direction, the material, film thickness, and formation location of the auxiliary electrode can be freely set. Therefore, the auxiliary electrode can be selectively formed in a place where a voltage drop is likely to occur, or can be formed over the entire light emitting region of the lighting device.

  The lighting device of the present invention is particularly preferably applied to a lighting device having a large area because variation in luminance due to a voltage drop caused by the relatively high resistance of the first electrode can be reduced.

(Embodiment 2)
The structure of the lighting device of the present invention will be described with reference to FIG. The lighting device shown in FIG. 5 is a top emission type lighting device that emits light from the side opposite to the substrate side. 5B is a top view of the light-emitting region of the lighting device, and FIG. 5A is a cross-sectional view in the vicinity of the opening of the light-emitting region (AA ′ in FIG. 5B).

  In FIG. 5, the substrate 501 is a thin substrate made of a flexible material. Specifically, a flexible substrate such as a plastic substrate, a polyester film, or an acrylic resin film can be used.

A second electrode 502 is formed over the substrate 501. A known material can be used for the second electrode 502. When the second electrode 502 is a cathode, it is preferable to use a conductive material having a low work function. Specifically, alkaline metals such as Li and Cs and alkaline earth metals such as Mg, Ca, and Sr are used. , And alloys containing these (Mg: Ag, Al: Li, etc.), and rare earth metals such as Yb and Er can also be used. Further, LiF, CsF, in the case of using an electron injecting layer such as CaF _2, Li ₂ O, may be used usual conductive thin film such as aluminum. In the case where the second electrode 502 is an anode, a conductive material having a high work function is preferably used. Specifically, in addition to a single layer film such as TiN, ZrN, Ti, W, Ni, Pt, Cr, etc., a laminate of a film mainly composed of titanium nitride and aluminum, and a titanium nitride film and aluminum are the main components. A three-layer structure of a film and a titanium nitride film can be used. Or the method of laminating | stacking a transparent conductive film on reflective electrodes, such as Ti and Al, may be used.

  A layer 503 containing a light-emitting substance is formed over the second electrode 502. A known material can be used for the layer 503 containing a light-emitting substance, and either a low molecular material or a high molecular material can be used. Note that the material for forming a layer containing a light-emitting substance includes not only an organic compound material but also a structure including an inorganic compound in part. The layer containing a light-emitting substance is configured by appropriately combining a hole injection layer, a hole transport layer, a hole blocking layer (hole blocking layer), a light emitting layer, an electron transport layer, an electron injection layer, and the like. You may comprise by a layer and it is good also as a structure which laminated | stacked several layers.

  Note that the layer 503 containing a light-emitting substance may have a structure in which layers containing a plurality of light-emitting substances are stacked. With the stacked structure, the luminance is improved by stacking even with the same current. In particular, a structure in which layers containing a light-emitting substance are stacked is suitable for lighting applications that require high luminance. In addition, in the case of a structure in which a plurality of layers containing light-emitting substances are stacked, a structure in which layers containing light-emitting substances made of the same material are stacked may be used, or layers containing light-emitting substances made of different materials It is good also as a structure which laminated | stacked.

  A transparent conductive film is formed as the first electrode 504 over the layer 503 containing a light-emitting substance. Examples of the transparent conductive film include indium tin oxide (hereinafter referred to as ITO), indium tin oxide containing silicon, indium oxide containing 2 to 20% zinc oxide (ZnO), and the like.

  The substrate 501, the second electrode 502, the light-emitting substance layer 503, and the first electrode 504 each include an opening 507, the vicinity of the opening of the first electrode 504 and the substrate 501, and the sidewall of the opening An insulating film 505 is formed so as to cover. By this insulating film 505, the first electrode 504 and the second electrode 502, and the second electrode 502 and the auxiliary electrode 506 are electrically insulated from each other. Note that this insulating film 505 may function as a protective film that prevents permeation of a substance that causes deterioration of a layer containing a light-emitting substance such as moisture or oxygen.

  The auxiliary electrode 506 is formed near the lower surface of the substrate, the opening, and the opening of the first electrode, and the first electrode and the auxiliary electrode are electrically connected in the vicinity of the opening. As the auxiliary electrode 506, a material having a low resistivity is preferably used. Specifically, a material such as aluminum, copper, or silver can be used. The diameter of the opening is 10 to 500 μm, preferably 50 to 200 μm.

A plurality of openings 507 are provided in the light emitting region 508. The auxiliary electrode 506 is electrically connected to the first electrode 504 through the opening 507, so that the influence of a voltage drop caused by the relatively high resistance of the transparent conductive film can be reduced. That is, the auxiliary electrode 506 is electrically connected to the first electrode 504 through the plurality of openings 507 provided in the light emitting region 508, thereby substantially reducing the resistance of the first electrode 504. ing. Thereby, it is possible to reduce a variation in luminance in which a portion away from the current supply terminal becomes dark. If the size of the opening is made sufficiently small, the presence of the auxiliary electrode can be almost ignored when the illumination device is viewed from the light emission direction, that is, from the translucent substrate side. Further, since the auxiliary electrode is not arranged in the light emission direction, the material, film thickness, and formation location of the auxiliary electrode can be freely set. Therefore, the auxiliary electrode can be selectively formed in a place where a voltage drop is likely to occur, or can be formed over the entire light emitting region of the lighting device.

  The lighting device of the present invention is particularly preferably applied to a lighting device having a large area because variation in luminance due to a voltage drop caused by the relatively high resistance of the first electrode can be reduced.

(Embodiment 3)
One embodiment of the lighting device of the present invention will be described with reference to FIGS. Note that FIG. 13A is a cross-sectional view taken along line AA ′ of the lighting device shown in the top view of FIG.

  13A and 13B, an insulating layer 11 is provided over the substrate 10. As shown in FIG. 13B, the insulating layer 11 is formed in a lattice shape over the substrate 10. The insulating layer 11 contains a fluorescent material. A wiring 13 is formed on the insulating layer 11.

  On the insulating layer 11 and the wiring 13, a first electrode 12 is provided so as to cover the insulating layer 11 and the wiring 13. A layer 14 containing a light emitting substance is provided on the first electrode 12. Further, a second electrode 15 is formed on the layer 14 containing a light emitting substance.

  Here, there is no particular limitation on the first electrode 12, but an electrode that can transmit visible light is preferable, and the same electrode as the first electrode 102 described in Embodiment 1 can be used. There is no particular limitation on the second electrode 15, and the same material as the second electrode 104 described in Embodiment 1 can be used. Further, there is no particular limitation on the layer 14 containing a light-emitting substance, and the same layer as the layer 103 containing a light-emitting substance described in Embodiment Mode 1 can be used.

  Moreover, although there is no limitation in particular about the wiring 13, it is preferable to consist of metals with small resistance values, such as aluminum and copper.

Further, the fluorescent substance contained in the insulating layer 11 is not particularly limited, and 9,10-diphenylanthracene, 9,10-di-2-naphthylanthracene, 9,10-bis (4-diphenylaminophenyl) anthracene, rubrene. In addition to polycyclic aromatic compounds such as 1,2,3,4,5-pentaphenylcyclopentadiene, p-sexiphenyl, perylene, 2,5,8,11-tetra-tert-butylperylene, Diphenyloxazole, 1,4-bis (5-phenyloxazol-2-yl) benzene, 1,4-bis (4-methyl-5-phenyloxazol-2-yl) benzene, 2- (1-naphthyl) -5 -Phenyloxazole, 2- (4-biphenylyl) -6-phenylbenzoxazole, 2,5-bis (5-tert-butyl) Benzoxazol-2-yl) thiophene, 2- (4-biphenylyl) -6-phenylbenzoxazole, 2- (4-biphenylyl) -5-phenyl-1,3,4-oxadiazole, 2- (4- tert-butylphenyl) -5- (4-biphenylyl) -1,3,4-oxadiazole, 2,4-diphenyl-1,3,4-oxadiazole, hetero-aromatic compounds such as lophine, coumarin 6 Coumarin 6H, Coumarin 7, Coumarin 30, Coumarin 102, Coumarin 120, Coumarin 151, Coumarin 152, Coumarin 153, Coumarin 314, Coumarin 334, Coumarin 337, Coumarin 343, Coumarin 480D, Coumarin 545T, etc. (Dicyanomethylene) -2-methyl-6- [2- (4-dimethylamino) Phenyl) ethenyl] -4H-pyran, 4- (dicyanomethylene) -2-methyl-6- [2- (julolidin-9-yl) ethenyl] -4H-pyran, 4- (dicyanomethylene) -2-methyl- 6- [2- (2,2,7,7-Tetramethyljulolidin-9-yl) ethenyl] -4H-pyran, 4- (dicyanomethylene) -2-tert-butyl-6- [2- (2 , 2,7,7-Tetramethyljulolidin-9-yl) ethenyl] -4H-pyran, 4- (dicyanomethylene) -2-isopropyl-6- [2- (2,2,7,7-tetramethyl) Pyran compounds such as julolidin-9-yl) ethenyl] -4H-pyran, 1,1,4,4-tetraphenyl-1,3-butadiene, 1,4-bis (2-methylstyryl) benzene, 4 , 4'-bis ( , 2-diphenylethenyl) styrene compounds such as biphenyl, rhodamine B, rhodamine 6G, rhodamine 575, fluorescein, can be used xanthene compounds such as Nile Red.

  Here, the surface height of the layer 14 containing the luminescent material (the surface of the substrate 10, that is, the length from the reference surface to the surface when the substrate surface is used as a reference surface) is lower than the surface height of the insulating layer 11. Is preferred. Accordingly, light emitted from the layer 14 containing a light-emitting substance can easily enter the insulating layer 11.

  Note that an insulating layer containing silicon nitride or silicon oxide may be provided between the first electrode 12 and the substrate 10. By providing such an insulating layer, moisture mixed through the substrate 10 can be prevented from entering the layer 14 containing a light-emitting substance.

  In the lighting device as described above, the wiring 13 is provided, whereby the voltage drop in the first electrode 12 is reduced.

  Further, in the lighting device having the above-described structure, the light-emitting substance excited by recombination of the holes injected from the first electrode 12 and the electrons injected from the second electrode 15 has a base. It emits light when returning to the state. Furthermore, in the lighting device of this embodiment, the light emitted in a direction parallel to the substrate surface enters the insulating layer 11 and the fluorescent material contained in the insulating layer 11 emits light.

  In this way, the fluorescent material contained in the insulating layer 11 emits light, whereby light can be obtained from the entire substrate surface of the substrate 10.

(Embodiment 4)
In this embodiment, a method for manufacturing the lighting device described in Embodiment 3 will be described with reference to FIGS. 14A to 14C and FIGS. 15A to 15C. 14A, 14B, and 14C are cross-sectional views taken along line AA ′ of the lighting device shown in the top views of FIGS. 15A, 15B, and 15C, respectively. is there.

  First, an insulating layer and a conductive layer are sequentially formed on the substrate 10 and then processed into a desired shape to form the insulating layer 11 and the wiring 13. The insulating layer 11 is not particularly limited, and may be an insulating layer containing a fluorescent material. Examples of such an insulating layer include siloxane, acrylic, polyimide, and the like. The wiring 13 is not particularly limited, but is preferably formed using a low resistance material such as aluminum or copper. Aluminum may contain nickel, silicon, or the like.

  Next, the first electrode 12 that covers the substrate 10, the insulating layer 11, and the wiring 13 is formed on the substrate 10, the insulating layer 11, and the wiring 13. There is no particular limitation on the first electrode 12, and the first electrode 12 is preferably formed using a material similar to that of the first electrode 102 described in Embodiment 1. Further, the method for forming the first electrode 12 is not particularly limited, and may be formed using a sputtering method or the like.

  In this embodiment, the insulating layer 11 and the wiring 13 are processed by etching continuously using the same resist mask. However, the present invention is not limited to this. For example, after forming the insulating layer 11 having a desired shape, a conductive layer covering the insulating layer 11 is formed, and the conductive layer is processed into a desired shape to form the wiring 13. It doesn't matter. Note that in this embodiment mode, the insulating layer 11 is formed in a lattice shape as shown in FIG.

  Next, a layer 14 containing a light-emitting substance is formed so as to cover the first electrode 12, the insulating layer 11, and the wiring 13. There is no particular limitation on the layer 14 containing a light-emitting substance, and a layer having a structure similar to that of the layer 103 containing a light-emitting substance described in Embodiment 1 may be formed by an evaporation method, an inkjet method, or the like.

  Next, the second electrode 15 is formed over the layer 14 containing a light-emitting substance. There is no particular limitation on the second electrode 15, and the second electrode 15 is preferably formed using a material similar to that of the second electrode 104 described in Embodiment 1. The method for forming the second electrode 15 is not particularly limited, and may be formed by using a sputtering method, a vapor deposition method, or the like.

  Note that the first electrode 12 and the second electrode 15 are preferably stacked so as not to contact each other. For example, in this embodiment, the first electrode 12 and the second electrode 15 are formed so that one edge of the first electrode 12 and the second electrode 15 is located inside the layer 14 containing a light-emitting substance. Contact with the second electrode 15 is prevented.

(Embodiment 5)
One embodiment of the lighting device of the present invention will be described with reference to FIGS. Note that FIG. 16A is a cross-sectional view taken along line AA ′ of the lighting device shown in the top view of FIG.

  In FIGS. 16A and 16B, a first electrode 31 is provided on a substrate 30. An insulating layer 32 having a recess is formed on the first electrode 31. As shown in FIG. 16B, the insulating layer 32 is formed in a lattice shape over the first electrode 31. The insulating layer 32 contains a fluorescent material. A wiring 33 is formed in the recess of the insulating layer 32. An opening is provided in the recess of the insulating layer 32, and the wiring 33 and the first electrode 31 are connected through the opening.

  The first electrode 31, the insulating layer 32, and the wiring 33 are covered with a layer 34 containing a light emitting substance. Further, a second electrode 35 is formed on the layer 34 containing a light emitting substance.

  Here, although there is no limitation in particular about the wiring 33, it is preferable to consist of metals with small resistance values, such as aluminum and copper.

  Note that the surface height of the layer 34 containing a light-emitting substance is preferably lower than the surface height of the insulating layer 32.

  Further, there is no particular limitation on the fluorescent material, and the fluorescent material described in Embodiment 3 can be used.

There is no particular limitation on the first electrode 31, but an electrode that can transmit visible light is preferable. The same electrode as the first electrode 102 described in Embodiment 1 can be used. There is no particular limitation on the second electrode 35, and the same material as the second electrode 104 described in Embodiment Mode 1 can be used. There is no particular limitation on the layer 34 containing a light-emitting substance, and the same layer as the layer 103 containing a light-emitting substance described in Embodiment Mode 1 can be used.

  In the lighting device as described above, the wiring 33 is provided, whereby the voltage drop in the first electrode 31 is reduced.

  In addition, in the lighting device having the above-described structure, the light-emitting substance excited by recombination of the holes injected from the first electrode 31 and the electrons injected from the second electrode 35 has a base. It emits light when returning to the state. Furthermore, in the lighting device of this embodiment, the light emitted in the direction parallel to the substrate surface enters the insulating layer 32 and the fluorescent material contained in the insulating layer 32 emits light.

  In this way, light emission can be obtained from the entire substrate surface of the substrate 30 when the fluorescent material contained in the insulating layer 32 emits light.

  In this embodiment, a method for manufacturing the lighting device of the present invention illustrated in FIG. 1 will be described with reference to FIGS.

  A transparent conductive film which is the first electrode 202 is formed over the light-transmitting substrate 201. In this embodiment, a glass substrate is used as the light-transmitting substrate 201 and ITO is formed as the first electrode 202.

  Next, a layer 203 containing a light-emitting substance is formed over the first electrode 202. A known material can be used for the layer 203 containing a light-emitting substance. Alternatively, a structure in which layers containing a plurality of light-emitting substances are stacked may be employed.

  A second electrode 204 is formed over the layer 203 containing the light-emitting substance (FIG. (A)). The second electrode 204 has an opening, and may be formed over the entire surface of the layer containing a light-emitting substance and then patterned by photolithography, or may be formed using a mask. In this embodiment, aluminum is used for the second electrode 204 and is formed over the entire surface of the layer 203 containing a light-emitting substance, and then patterned by a photolithography method. After that, using the patterned second electrode as a mask, an opening is formed in the layer containing a light-emitting substance (FIG. 2B).

  Next, an insulating film 205 is formed so as to cover the layer 203 containing a light-emitting substance and the second electrode 204 (FIG. 2C). The insulating film 205 also has an opening. After the film is formed over the entire surface, the insulating film 205 may be patterned by a photolithography method or may be formed using a mask. In this embodiment, silicon oxide is used for the insulating film 205.

  Next, the auxiliary electrode 206 is formed (FIG. 2D). The auxiliary electrode 206 preferably has a low resistance, and aluminum is used in this embodiment. The auxiliary electrode 206 is electrically connected to the first electrode 202 at the opening 207 and is insulated from the second electrode 204.

  As described above, the ITO that is the first electrode 202 is connected to the auxiliary electrode 206 and the opening 207, and thus the influence of the voltage drop caused by the relatively high resistance of the first electrode can be reduced. it can. Therefore, when applied to a lighting device having a large area, variation in luminance can be reduced. Further, if the opening 207 is sufficiently small, the presence of the auxiliary electrode can be almost ignored when the illumination device is viewed from the light emission direction, that is, the translucent substrate side.

  In this embodiment, the layer containing the light emitting material is formed over the entire surface and then patterned using aluminum as a mask. However, the layer containing the light emitting material may be formed using the mask so as to have an opening. .

  FIG. 3 illustrates a method in which the layer 303 containing a light-emitting substance and the second electrode 304 are each formed using a mask. That is, after the first electrode 302 is formed over the entire surface of the substrate 301, a layer 303 containing a light-emitting substance and a second electrode 304 are formed using a mask, respectively, and an insulating film 305, an auxiliary electrode 306, an opening portion are formed. 307 may be formed in the same manner as described above. At this time, the opening of the second electrode 304 is made larger than the layer 303 containing a light-emitting substance, whereby insulation between the first electrode and the second electrode can be further ensured.

  In this embodiment, a manufacturing method different from that of Embodiment 1 of the lighting device of the present invention shown in FIG. 1 will be described with reference to FIGS.

  A transparent conductive film which is the first electrode 402 is formed over the light-transmitting substrate 401. In this embodiment, a glass substrate is used as the light-transmitting substrate 401 and ITO is formed as the first electrode 402.

  Next, a layer 403 containing a light-emitting substance and a second electrode 404 are sequentially formed (FIG. 4A). In this embodiment, aluminum is deposited as the second electrode 404.

Next, laser light is irradiated from the light-transmitting substrate 401 side to form openings (FIG. 4B). As the laser light, laser light having a wavelength that passes through the glass substrate and ITO and is absorbed by the layer 403 containing a light-emitting substance and the second electrode 404 is used. In this embodiment, laser light having a wavelength of 532 nm is used. Laser light with a wavelength of 532 nm is obtained by converting a fundamental wave (wavelength 1064 nm) such as a YAG laser or a YVO ₄ laser into a second harmonic by a nonlinear optical element. The layer containing the light-emitting substance that has absorbed the laser light and the second electrode are heated and sublimated to form an opening. After the opening is formed, the insulating film 405 and the auxiliary electrode 406 are formed in the same manner as in the first embodiment so that the first electrode 402 and the auxiliary electrode 406 are electrically connected to each other in the opening 407. . (FIG. 4C).

  In this embodiment, a method for manufacturing the lighting device of the present invention illustrated in FIG. 5 will be described with reference to FIGS.

  A second electrode 602, a layer 603 containing a light-emitting substance, and a first electrode 604 are formed over a thin substrate 601 made of a flexible material. In this embodiment, aluminum is formed as the second electrode 602 and ITO is formed as the first electrode 604 over the polyester film (FIG. 6A).

  Next, an opening is formed in the substrate 601, the second electrode 602, the layer 603 containing a light-emitting substance, and the first electrode 604 (FIG. 6B). Since the substrate 601 is formed of a flexible material, the opening can be easily provided by applying physical force.

  Next, a silicon oxide film is formed as the insulating film 605. The silicon oxide film is formed by a sputtering method or an evaporation method using a mask (FIG. 6C). By using a sputtering method or a vapor deposition method, a silicon oxide film is formed through the opening and around the surface opposite to the surface on which the film is to be formed. As a result, the insulation between the second electrode 602 and the auxiliary electrode 606 is more reliable.

  Next, the auxiliary electrode 606 is formed. First, silver is deposited on the first electrode 604 side by a printing method. At this time, silver is filled in the opening 607 by using a printing method (FIG. 7A). Next, silver is formed over the entire surface from the substrate 601 side (FIG. 7B). Thus, the first electrode 604 and the auxiliary electrode 606 are electrically connected. Thereby, the influence of the voltage drop resulting from the relatively high resistance of the first electrode can be reduced. Therefore, when applied to a lighting device having a large area, variation in luminance can be reduced.

  In the structure of this example, ITO as the first electrode and silver as the auxiliary electrode are connected in the light emission direction. However, if the opening 607 is sufficiently small, When the illumination device is viewed from the emission direction, that is, from the first electrode side, the presence of the auxiliary electrode can be almost ignored.

  In this embodiment, an example of the entire structure of the lighting device of the present invention will be described with reference to FIG.

  8A and 8B are a top view and a cross-sectional view of the lighting device of the present invention. The lighting device of the present invention includes a substrate 801, a first electrode 802, a layer 803 containing a light-emitting substance, a second electrode 804, and an insulating film 805. The auxiliary electrode 806 is provided, and the first electrode 802 and the auxiliary electrode 806 are electrically connected in the opening 807. A plurality of openings 807 are provided in the light emitting region. In addition, a second insulating film 808 is provided at an end portion of the light emitting region, and serves to prevent the first electrode 802 and the second electrode 804 from being short-circuited. The current supply terminals 809 are connected to the second electrode 804 and the auxiliary electrode 806, respectively. The light emitting region is sealed with a sealing material 810. In order to prevent deterioration of the layer containing a light-emitting substance, the sealing material is preferably a material that does not transmit moisture and oxygen as much as possible. Further, a filler 811 is filled in the inside surrounded by the sealing material. The inside surrounded by the sealing material may be filled with an inert gas (nitrogen, argon, or the like) or a material having the same quality as the sealing material instead of the filler.

  FIG. 8 illustrates the structure shown in Embodiment 1, but the structures shown in Embodiment 2 and Embodiment 3 can be similarly sealed and used as a lighting device.

  In this embodiment, an example of a device using the lighting device of the present invention will be described with reference to FIGS.

  FIG. 9 shows an example of a liquid crystal display device using the lighting device of the present invention as a backlight. The liquid crystal display device illustrated in FIG. 9 includes a housing 901, a liquid crystal layer 902, a backlight 903, and a housing 904, and the liquid crystal layer 902 is connected to a driver IC 905. The backlight 903 uses the lighting device of the present invention, and a current is supplied from a terminal 906.

  By using the lighting device of the present invention as a backlight of a liquid crystal display device, a backlight with little variation in luminance can be obtained, so that the quality as a display device is improved. In addition, since the backlight can have a large area, the liquid crystal display device can have a large area. Further, since the light emitting element is thin and has low power consumption, the display device can be thinned and the power consumption can be reduced.

  FIG. 10A illustrates an example in which the lighting device of the present invention is used for indoor lighting. The illuminating device of the present invention is a surface emitting illuminating device, and since there is little variation in luminance even when the area is increased, for example, the illuminating device of the present invention can be used on the entire ceiling surface. Further, the lighting device of the present invention can be used not only on the ceiling but also on walls, floors, pillars, and the like. Furthermore, since the lighting device of the present invention has flexibility, it can be installed on a curved surface. Further, it can be used not only indoors but also outdoors, and can be installed on a building wall or the like as an external light.

  FIG. 10B illustrates an example in which the lighting device of the present invention is used as lighting in a tunnel. Since the lighting device of the present invention has flexibility, it can be installed along the curved surface of the wall in the tunnel.

  FIG. 10C illustrates an example in which the lighting device of the present invention is used as interior lighting. Since the lighting device of the present invention is thin, flexible, and has surface emission, it can be processed into a free shape as shown in FIG.

  The lighting device of the present invention can also be used as lighting when taking a photograph. When taking a picture, it is possible to take a picture similar to the case where the subject is illuminated with natural light by illuminating the subject with light having a uniform luminance with a large area.

Sectional drawing and top view of the light emission area | region of the illuminating device of this invention. 4A and 4B illustrate a method for manufacturing a lighting device of the present invention. 4A and 4B illustrate a method for manufacturing a lighting device of the present invention. 4A and 4B illustrate a method for manufacturing a lighting device of the present invention. Sectional drawing and top view of the light emission area | region of the illuminating device of this invention. 4A and 4B illustrate a method for manufacturing a lighting device of the present invention. 4A and 4B illustrate a method for manufacturing a lighting device of the present invention. The top view and sectional drawing of the illuminating device of this invention. The figure which shows an example of the apparatus using the illuminating device of this invention. The figure which shows an example of the apparatus using the illuminating device of this invention. The figure which shows an example of the layer containing the luminescent substance of the illuminating device of this invention. The figure which shows an example of the layer containing the luminescent substance of the illuminating device of this invention. The figure explaining the aspect of the illuminating device of this invention. 4A and 4B illustrate a method for manufacturing a lighting device of the present invention. 4A and 4B illustrate a method for manufacturing a lighting device of the present invention. The figure explaining the aspect of the illuminating device of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Substrate 11 Insulating layer 12 1st electrode 13 Wiring 14 Layer 15 containing luminescent substance Second electrode 30 Substrate 31 First electrode 32 Insulating layer 33 Wiring 34 Layer 35 containing luminescent substance Second electrode 101 Substrate 102 First 1 electrode 103 layer 104 containing luminescent material second electrode 105 insulating film 106 auxiliary electrode 107 opening 108 light emitting region 201 substrate 202 first electrode 203 layer 204 containing luminescent material second electrode 205 insulating film 206 auxiliary electrode 207 Opening 301 Substrate 302 First electrode 303 Layer containing luminescent substance 304 Second electrode 305 Insulating film 306 Auxiliary electrode 307 Opening 401 Substrate 402 First electrode 403 Layer containing luminescent substance 404 Second electrode 405 Insulation Film 406 Auxiliary electrode 407 Opening 501 Substrate 502 First electrode 503 Layer 504 containing luminescent substance Second electrode 5 5 Insulating film 506 Auxiliary electrode 507 Opening portion 508 Light emitting region 601 Substrate 602 First electrode 603 Layer 604 containing luminescent material Second electrode 605 Insulating film 606 Auxiliary electrode 607 Opening portion 801 Substrate 802 First electrode 803 Including layer 804 Second electrode 805 Insulating film 806 Auxiliary electrode 807 Opening 808 Insulating film 809 Current supply terminal 810 Sealing material 811 Filler 901 Housing 902 Liquid crystal layer 903 Backlight 904 Housing 905 Driver IC
906 Terminal 1100 Substrate 1101 First electrode (anode)
1102 Layer 1103 containing luminescent substance Second electrode (cathode)
1111 Hole injection layer 1112 Hole transport layer 1113 Light emitting layer 1114 Electron transport layer 1115 Electron injection layer 1200 Substrate 1201 First electrode 1202 First layer 1203 containing a light emitting substance Charge generation layer 1204 Second layer containing a light emitting substance

Claims (14)

A layer containing a light-emitting substance is formed between the first electrode and the second electrode,
An illumination device, comprising: a third electrode connected to the first electrode through an opening formed in the second electrode and the layer containing the light-emitting substance. A layer containing a light-emitting substance is provided between the first electrode and the second electrode;
A third electrode that is insulated from the second electrode is provided on the second electrode side, and the third electrode is formed in the layer containing the light-emitting substance and the second electrode. The lighting device is connected to the first electrode through the opened opening. 3. The lighting device according to claim 1, wherein light emitted from the layer containing the light-emitting substance is emitted from the first electrode side. 4. The lighting device according to claim 1, wherein the first electrode is made of a transparent conductive film. 5. The lighting device according to claim 1, wherein a plurality of the openings are provided. A layer containing a light emitting material in which a first opening is formed on a first electrode made of a transparent conductive film, and a second electrode in which a second opening is formed include the first opening. And the second opening are arranged so as to overlap each other,
An insulating layer provided on the second electrode, covering the first opening, the second opening, and the side of the second opening, and having a third opening formed thereon;
A third electrode provided on the insulating layer and in contact with the first electrode through the first to third openings;
An illumination device comprising: 7. The lighting device according to claim 6, wherein light emitted from the layer including the luminescent material is emitted from the first electrode side. The lighting device according to claim 6, wherein a width of the first opening and a width of the second opening are the same. The lighting device according to claim 6, wherein widths of the first opening and the second opening are different. 10. The lighting device according to claim 6, wherein a plurality of the first to third openings are provided in the light emitting region. 11. The lighting device according to claim 1, wherein the layer containing a light-emitting substance has a structure in which a plurality of layers containing a light-emitting substance are stacked. A first electrode;
A second electrode;
A layer including a luminescent material provided between the first electrode and the second electrode;
An insulating layer formed in a lattice shape on the substrate and containing a fluorescent material;
Wiring provided on the insulating layer;
Have
The lighting device, wherein the insulating layer and the wiring are covered with a first electrode so that the first electrode and the wiring are in contact with each other.   13. The lighting device according to claim 12, wherein a distance from the substrate surface to the surface of the layer containing the luminescent material is lower than a distance from the substrate surface to the surface of the insulating layer. A first electrode;
A second electrode;
A layer including a luminescent material provided between the first electrode and the second electrode;
An insulating layer formed in a lattice shape and containing a fluorescent agent;
Wiring and
Have
The insulating layer has a recess and an opening provided in the recess,
The wiring is provided in a recess of the insulating layer;
The lighting device is connected to the first electrode through the opening.

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