JP4962452B2 - Surface light emitting device and light emitting panel - Google Patents

Description

  The present invention relates to a large-sized light emitting panel formed by joining a surface light emitting element and a plurality of surface light emitting elements.

  In recent years, there has been an increasing demand for large-sized light-emitting panels for lighting or displays. The development of large-sized light-emitting elements has had difficult problems such as an increase in manufacturing and device costs and difficulty in suppressing in-plane luminance unevenness in a large area.

  On the other hand, studies have been made to construct a large light emitting panel by joining small light emitting panels together. However, since a joint between small-sized light-emitting panels exists as a non-light-emitting portion, it has been conventionally studied to make the joint inconspicuous because the visibility is poor.

  An element structure in which the sealing helicopter part of each light-emitting element to be joined has a roundness toward the outside at the end of the light-emitting layer, and light is emitted in an oblique direction from the sealing helicopter part to the joint part. Has been reported (for example, see Patent Document 1). Moreover, the structure which installs a color conversion filter in the light-projection surface side which bonded the side surfaces of several light emitting elements has been reported (for example, refer patent document 2). Furthermore, a configuration has been reported in which a plurality of light-emitting panels using thin-film bonding plates for side sealing are joined to reduce the distance between the individual light-emitting panels (see, for example, Patent Document 3). There has also been reported a display configuration in which a plurality of panels in the vicinity of the joint are connected as small-sized and high-luminance light emission (for example, see Patent Document 4).

However, in all of these conventional technologies, the seam remains as a non-light-emitting portion. In particular, when using an organic electroluminescence element that has been developed in recent years, each element is sufficiently sealed. It is necessary to secure a sufficient space for sealing between the light emitting surfaces of adjacent elements, and the method of arranging the elements in the in-plane direction still has a limit in improving the visibility. .
JP 2001-57288 A JP 2006-164618 A JP 2007-200267 A JP 2007-304584 A

  An object of the present invention has been made in view of the above circumstances, a large-sized light-emitting panel formed by joining a plurality of surface light-emitting elements with high visibility and reduced in-plane luminance unevenness, and the light-emitting panel Another object of the present invention is to provide a surface light emitting device used for the above.

  The above object of the present invention can be achieved by the following configuration.

  1. A surface light emitting device having a light emitting layer between at least a first electrode and a second electrode, wherein the first electrode is a light transmissive electrode, and the second electrode is in a direction perpendicular to the light emitting surface of the surface light emitting device. A surface light emitting device comprising: a light-transmitting central portion and a light-transmitting peripheral portion in a light-emitting region viewed from above.

  2. 2. The surface light emitting device according to 1 above, wherein the surface light emitting device is an organic electroluminescence device.

  3. A light emitting panel, wherein a plurality of the surface light emitting elements according to 1 or 2 are arranged so that a part of the light emitting regions of the surface light emitting elements as seen from the direction perpendicular to the light emitting surface overlap each other.

  4). 4. The light emitting panel as described in 3 above, wherein a part of the light emitting region of one surface light emitting element and the peripheral portion of the second electrode of the other surface light emitting element are arranged to overlap each other.

  According to the present invention, a large-sized light-emitting panel formed by joining a plurality of surface light-emitting elements with high visibility and reduced in-plane luminance unevenness and a surface light-emitting element used in the light-emitting panel can be provided. .

  The surface light emitting device of the present invention is a surface light emitting device having a light emitting layer at least between a first electrode and a second electrode, wherein the first electrode is a light transmissive electrode and the second electrode is a surface light emitting device. In the light emitting region as viewed from the direction perpendicular to the light emitting surface of the element, the electrode is composed of a light-impermeable central part and a light-transmissive peripheral part.

  The light-emitting panel of the present invention is a large-sized light-emitting panel formed by joining a plurality of the surface light-emitting elements. A plurality of light emitting regions of the surface light emitting element viewed from the direction perpendicular to the light emitting surface are arranged so as to overlap each other. The surface light-emitting elements are arranged so that the first electrode side of one surface light-emitting element and the second electrode side of the other surface light-emitting element are opposed to each other, and one of the light emitting regions of one surface light-emitting element is arranged. And the peripheral part of the second electrode of the other surface light emitting element are arranged so as to overlap each other, and by making the overlapping region light transmissive, the junction part itself of the surface light emitting elements can emit light. it can. In this light-transmitting region, ITO, zinc oxide, tin oxide, and other various transparent conductive material thin films can be used. In order to lower the resistance, it can be laminated with a thin film of silver, alkali metal, alkaline earth metal, or a compound thereof. It can be formed by any method such as sputtering, vapor deposition, or wet method.

  With this panel structure, the non-light-emitting area of the light-emitting panel connection part is reduced or the non-light-emitting area of the connection part does not exist. be able to. In addition, in-plane luminance unevenness of the light-emitting panel can be reduced.

  Further, unlike the case where the surface light emitting elements are arranged in the same plane, it is not necessary to reduce the non-light emitting area of the connecting portion by forcibly narrowing the interval between the light emitting areas. It can be sufficiently secured, and can be preferably applied to the case of using an organic electroluminescence element in which prevention of intrusion of oxygen and moisture from the outside of the element is particularly important.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The embodiments of the present invention are not limited to these.

  FIG. 1 is a cross-sectional view of a surface light emitting device of the present invention.

  On the substrate 1, a first electrode 2, a functional layer 3 including a light emitting layer, and a second electrode 4 are sequentially stacked. Furthermore, although omitted in the drawing, sealing, a protective film, an auxiliary electrode, and the like may be provided as necessary, and electrodes other than the first electrode 2 and the second electrode 4 may be laminated. Further, the arrangement of the first electrode 2 and the second electrode 4 may be reversed.

  In addition to the light emitting layer, the functional layer 3 including the light emitting layer includes a charge injection layer, a charge transport layer, an insulating layer, a carrier block layer, an intermediate layer, a light adjustment layer, a protective film, a barrier layer, and a mixed layer thereof. It can be provided arbitrarily.

  In the present invention, the first electrode 2 is a light-transmitting electrode, and the second electrode 4 has a light-impermeable central portion and a light-transmitting peripheral portion in the light emitting region viewed from the direction perpendicular to the light emitting surface. It is the electrode comprised by these.

  FIG. 2 is a view of the second electrode 4 in the light emitting region of the surface light emitting element of the present invention as seen from the direction perpendicular to the light emitting surface. The second electrode 4 is composed of a light-impermeable central portion 5 and a light-transmissive peripheral portion 6. In the present invention, the central portion is a light emitting region viewed from the direction perpendicular to the light exit surface. It is an area including the center of gravity in the plane.

  In the present invention, “light impermeability” means that the visible light transmittance is less than 10%, preferably less than 7%, and more preferably less than 5%. In the present invention, light transmittance means that the visible light transmittance is 10% or more and 100% or less, preferably 30% or more and 100% or less, and more preferably 50% or more and 100% or less. .

  In the present invention, the area of the light-impermeable region of the second electrode is preferably 25% or more and less than 95%, more preferably 50% or more and less than 90% of the area of the light emitting region. The area of the light transmissive region is preferably 5% or more and less than 75% of the area of the light emitting region, and more preferably 10% or more and less than 50%.

  Examples of other shapes of the second electrode according to the present invention are shown in FIG. 3 to FIG. 6, and as illustrated in FIG. 2 or FIG. 3, the entire periphery is configured to be light transmissive. Is preferred.

  Examples of the shape of the surface light emitting device of the present invention are shown in FIGS. The surface light emitting device of the present invention can take various polygons, rectangles, circles, or various complicated shapes.

  FIGS. 8 to 10 show examples of a light-emitting panel configured by arranging a plurality of the surface light-emitting elements of the present invention so that a part of the light-emitting regions of the surface light-emitting elements viewed from the light emitting surface vertical direction overlap each other. . 8 (a), 9 (a), and 10 (a) are side views of each light emitting panel, and FIGS. 8 (b), 9 (b), and 10 (b) are each light emitting panel. It is the figure which looked at from the light emission surface perpendicular | vertical direction.

  In the present invention, it is preferable that the first electrode side of one surface light emitting element and the second electrode side of the other surface light emitting element are arranged so as to be opposed to each other. It is preferable that a part of the light emitting region and the peripheral part of the second electrode of another surface light emitting element are arranged so as to overlap each other. The area of the overlapping portions is preferably 30% or more and 100% or less, more preferably 50% or more and 100% or less, of the area of the light-transmitting peripheral portion of the second electrode.

  FIGS. 11 and 12 show another example of a light-emitting panel configured by arranging a plurality of light-emitting regions of a surface light-emitting element viewed from the light emitting surface vertical direction so that they overlap each other. Both are views of the light emitting panel as seen from the direction perpendicular to the light exit surface.

  The light-emitting panel of the present invention can also be configured using a plurality of surface light-emitting elements having different shapes and sizes, and three or more surface light-emitting elements are provided in a part where the light-emitting regions partially overlap each other. May overlap.

  In a light-emitting panel configured by arranging a plurality of light-emitting regions of a surface light-emitting element viewed from the light emitting surface vertical direction so as to overlap each other, the first electrode side of one surface light-emitting element and the other The second electrode side of the surface light emitting element is disposed so as to be opposed to each other, and a part of the light emitting region of one surface light emitting element and the peripheral part of the second electrode of the other surface light emitting element are: FIG. 13 shows an example of an enlarged view of the light emitting panels arranged to overlap each other as seen from the side surface direction with respect to the light emitting surface vertical direction.

  Each of the surface light emitting element 11 and the surface light emitting element 12 is configured by sequentially laminating a first electrode 2, a functional layer 3 including a light emitting layer 10 therein, and a second electrode 4 on a substrate 1. The first electrode 2 is a light transmissive electrode, and the second electrode 4 is composed of a light opaque central portion 5 and a light transmissive peripheral portion 6. The laminate formed on these substrates is covered with a sealing cover 7, and a water capturing agent 8 is provided in the sealing cover 7 and filled with nitrogen gas 9. The light emitting region is the light emitting layer 10 sandwiched between the first electrode 2 and the second electrode 4.

  The surface light emitting element 11 and the surface light emitting element 12 are partially overlapped with each other when viewed from the direction perpendicular to the light emitting surface. The surface light emitting element 11 and the surface light emitting element 12 have the first electrode 2 side. The two electrodes 4 are overlapped so as to face each other. Further, a part of the light emitting region of the surface light emitting element 11 and the light-transmitting peripheral portion 6 in the second electrode 4 of the surface light emitting element 12 are arranged so as to overlap each other.

  The surface light emitting device according to the present invention is preferably an electroluminescence device, and more preferably an organic electroluminescence device (hereinafter also referred to as an organic EL device).

  Hereinafter, although the preferable aspect in the case of comprising the surface emitting element in connection with this invention with an organic EL element is demonstrated, this invention is not limited to this.

Preferred specific examples of the layer structure of the organic EL element are shown below.
(I) Anode / light emitting layer / electron transport layer / cathode (ii) Anode / hole transport layer / light emitting layer / electron transport layer / cathode (iii) Anode / hole transport layer / light emitting layer / hole blocking layer / electron Transport layer / cathode (iv) anode / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer / cathode (v) anode / anode buffer layer / hole transport layer / light emitting layer / hole Blocking layer / electron transport layer / cathode buffer layer / cathode Here, the light emitting layer preferably contains at least two kinds of light emitting materials having different emission colors, and a single layer or a light emitting layer comprising a plurality of light emitting layers A unit may be formed. The hole transport layer also includes a hole injection layer and an electron blocking layer.

<Light emitting layer>
The light emitting layer according to the present invention is a layer that emits light by recombination of electrons and holes injected from the electrode, the electron transport layer, or the hole transport layer, and the light emitting portion is in the layer of the light emitting layer. May be the interface between the light emitting layer and the adjacent layer.

  The light emitting layer according to the present invention is not particularly limited in its configuration as long as the contained light emitting material satisfies the above requirements.

  Moreover, there may be a plurality of layers having the same emission spectrum and emission maximum wavelength.

  It is preferable to have a non-light emitting intermediate layer between each light emitting layer.

  In the present invention, the total thickness of the light emitting layers is preferably in the range of 1 nm to 100 nm, and more preferably 30 nm or less because a lower driving voltage can be obtained. In addition, the sum total of the film thickness of the light emitting layer said by this invention is a film thickness also including this intermediate | middle layer, when a nonluminous intermediate | middle layer exists between light emitting layers.

  The thickness of each light emitting layer is preferably adjusted to a range of 1 nm to 50 nm, more preferably adjusted to a range of 1 nm to 20 nm. There is no particular limitation on the relationship between the film thicknesses of the blue, green and red light emitting layers.

  For the production of the light emitting layer, a light emitting material or a host compound, which will be described later, is formed by forming a film by a known thinning method such as a vacuum deposition method, a spin coating method, a casting method, an LB method, an ink jet method, or the like. it can.

  In the present invention, a plurality of light emitting materials may be mixed in each light emitting layer, and a phosphorescent light emitting material and a fluorescent light emitting material may be mixed and used in the same light emitting layer.

  In the present invention, the structure of the light-emitting layer preferably contains a host compound and a light-emitting material (also referred to as a light-emitting dopant compound) and emits light from the light-emitting material.

  In the present invention, the host compound contained in the light emitting layer of the organic EL device is preferably a compound having a phosphorescence quantum yield of phosphorescence emission at room temperature (25 ° C.) of less than 0.1. More preferably, the phosphorescence quantum yield is less than 0.01. Moreover, it is preferable that the volume ratio in the layer is 50% or more among the compounds contained in a light emitting layer.

  As the host compound, known host compounds may be used alone or in combination of two or more. By using a plurality of types of host compounds, it is possible to adjust the movement of charges, and the organic EL element can be made highly efficient. Moreover, it becomes possible to mix different light emission by using multiple types of luminescent material mentioned later, and can thereby obtain arbitrary luminescent colors.

  The host compound used in the present invention may be a conventionally known low molecular compound or a high molecular compound having a repeating unit, and a low molecular compound having a polymerizable group such as a vinyl group or an epoxy group (evaporation polymerizable light emitting host). )But it is good.

  As the known host compound, a compound that has a hole transporting ability and an electron transporting ability, prevents the emission of light from being increased in wavelength, and has a high Tg (glass transition temperature) is preferable. Here, the glass transition point (Tg) is a value obtained by a method based on JIS-K-7121 using DSC (Differential Scanning Colorimetry).

  Specific examples of known host compounds include compounds described in the following documents. For example, Japanese Patent Application Laid-Open Nos. 2001-257076, 2002-308855, 2001-313179, 2002-319491, 2001-357777, 2002-334786, 2002-8860 Gazette, 2002-334787 gazette, 2002-15871 gazette, 2002-334788 gazette, 2002-43056 gazette, 2002-334789 gazette, 2002-75645 gazette, 2002-338579 gazette. No. 2002-105445, No. 2002-343568, No. 2002-141173, No. 2002-352957, No. 2002-203683, No. 2002-363227, No. 2002-231453. No. 2003-3165, No. 2002-234888, No. 2003-27048, No. 2002-255934, No. 2002-286061, No. 2002-280183, No. 2002-299060. 2002-302516, 2002-305083, 2002-305084, 2002-308837, and the like.

  Next, the light emitting material will be described.

  As the light-emitting material according to the present invention, a fluorescent compound or a phosphorescent material (also referred to as a phosphorescent compound or a phosphorescent compound) is used.

  In the present invention, a phosphorescent material is a compound in which light emission from an excited triplet is observed. Specifically, it is a compound that emits phosphorescence at room temperature (25 ° C.), and the phosphorescence quantum yield is 0 at 25 ° C. A preferred phosphorescence quantum yield is 0.1 or more, although it is defined as 0.01 or more compounds.

  The phosphorescent quantum yield can be measured by the method described in Spectroscopic II, page 398 (1992 edition, Maruzen) of Experimental Chemistry Course 4 of the 4th edition. The phosphorescence quantum yield in a solution can be measured using various solvents. However, when a phosphorescent material is used in the present invention, the phosphorescence quantum yield (0.01 or more) is achieved in any solvent. Just do it.

  There are two types of light emission of the phosphorescent material. In principle, the carrier recombination occurs on the host compound to which the carrier is transported to generate an excited state of the host compound, and this energy is transferred to the phosphorescent material. Energy transfer type to obtain light emission from the phosphorescent light emitting material, and another one is that the phosphorescent light emitting material becomes a carrier trap, and recombination of carriers occurs on the phosphorescent light emitting material, and light emission from the phosphorescent light emitting material is obtained. Although it is a trap type, in any case, the excited state energy of the phosphorescent material is required to be lower than the excited state energy of the host compound.

  The phosphorescent light-emitting material can be appropriately selected from known materials used for the light-emitting layer of the organic EL element, and is preferably a complex compound containing a group 8-10 metal in the periodic table of elements. More preferably, an iridium compound, an osmium compound, a platinum compound (platinum complex compound), or a rare earth complex, and most preferably an iridium compound.

  Specific examples of the compound used as the phosphorescent material are shown below, but the present invention is not limited to these. These compounds are described, for example, in Inorg. Chem. 40, 1704-1711, etc.

  A fluorescent substance can also be used for the organic EL element according to the present invention. Typical examples of fluorescent emitters (fluorescent dopants) include coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squalium dyes, oxobenzanthracene dyes, fluorescein dyes, rhodamine dyes, and pyrylium dyes. Examples thereof include dyes, perylene dyes, stilbene dyes, polythiophene dyes, and rare earth complex phosphors.

  Conventionally known dopants can also be used in the present invention. For example, International Publication No. 00/70655 pamphlet, JP-A Nos. 2002-280178, 2001-181616, 2002-280179, 2001 181617, 2002-280180, 2001-247859, 2002-299060, 2001-313178, 2002-302671, 2001-345183, 2002. No. 324679, International Publication No. 02/15645, JP 2002-332291 A, 2002-50484, 2002-332292, 2002-83684, JP 2002-540572, JP 2 No. 02-117978, No. 2002-338588, No. 2002-170684, No. 2002-352960, Pamphlet of International Publication No. 01/93642, JP 2002-50483, No. 2002-1000047. No. 2002-173684, No. 2002-359082, No. 2002-17584, No. 2002-363552, No. 2002-184582, No. 2003-7469, No. 2002-525808. JP-A 2003-7471, JP-T 2002-525833, JP-A 2003-31366, JP-A 2002-226495, JP-A 2002-234894, JP-A 2002-2335076, JP-A 2002-24175 Gazette, 2001-319779, 2001-319780, 2002-62824, 2002-1000047, 2002-203679, 2002-343572, 2002-203678. A gazette etc. are mentioned.

  In the present invention, at least one light emitting layer may contain two or more kinds of light emitting materials, and the concentration ratio of the light emitting materials in the light emitting layer may vary in the thickness direction of the light emitting layer.

《Middle layer》
In the present invention, a case where a non-light emitting intermediate layer (also referred to as an undoped region) is provided between the light emitting layers will be described.

  The non-light emitting intermediate layer is a layer provided between the light emitting layers in the case of having a plurality of light emitting layers.

  The film thickness of the non-light emitting intermediate layer is preferably in the range of 1 nm to 20 nm, and further in the range of 3 nm to 10 nm suppresses interaction such as energy transfer between adjacent light emitting layers, and the device This is preferable because a large load is not applied to the current-voltage characteristics.

  The material used for the non-light emitting intermediate layer may be the same as or different from the host compound of the light emitting layer, but may be the same as the host material of at least one of the adjacent light emitting layers. preferable.

  The non-light-emitting intermediate layer may contain a non-light-emitting layer, a compound common to each light-emitting layer (for example, a host compound), and each common host material (where a common host material is used) In the case where the physicochemical characteristics such as phosphorescence emission energy and glass transition point are the same, or the molecular structure of the host compound is the same, etc.) The barrier is reduced, and the effect of easily maintaining the injection balance of holes and electrons even when the voltage (current) is changed can be obtained. Furthermore, by using a host material having the same physical characteristics or the same molecular structure as that of the host compound contained in each light emitting layer in the undoped light emitting layer, device fabrication, which is a major problem in conventional organic EL device fabrication, is achieved. Complexity can also be eliminated.

  When the organic EL device is used in the present invention, since the host material is responsible for carrier transport, a material having carrier transport capability is preferable. Carrier mobility is used as a physical property representing carrier transport ability, but the carrier mobility of an organic material generally depends on the electric field strength. Since a material having a high electric field strength dependency easily breaks the balance between injection and transport of holes and electrons, it is preferable to use a material having a low electric field strength dependency of mobility for the intermediate layer material and the host material.

  On the other hand, in order to optimally adjust the injection balance of holes and electrons, it is also preferable that the non-light emitting intermediate layer functions as a blocking layer described later, that is, a hole blocking layer and an electron blocking layer. It is done.

<< Injection layer: electron injection layer, hole injection layer >>
The injection layer is provided as necessary, and there are an electron injection layer and a hole injection layer, and as described above, it exists between the anode and the light emitting layer or the hole transport layer and between the cathode and the light emitting layer or the electron transport layer. May be.

  An injection layer is a layer provided between an electrode and an organic layer in order to reduce drive voltage and improve light emission luminance. “Organic EL element and its forefront of industrialization (issued by NTT Corporation on November 30, 1998) 2), Chapter 2, “Electrode Materials” (pages 123 to 166) in detail, and includes a hole injection layer (anode buffer layer) and an electron injection layer (cathode buffer layer).

  The details of the anode buffer layer (hole injection layer) are described in JP-A-9-45479, JP-A-9-260062, JP-A-8-288069 and the like. As a specific example, copper phthalocyanine is used. Examples thereof include a phthalocyanine buffer layer represented by an oxide, an oxide buffer layer represented by vanadium oxide, an amorphous carbon buffer layer, and a polymer buffer layer using a conductive polymer such as polyaniline (emeraldine) or polythiophene.

  The details of the cathode buffer layer (electron injection layer) are described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like. Specifically, strontium, aluminum, etc. Metal buffer layer typified by lithium, alkali metal compound buffer layer typified by lithium fluoride, alkaline earth metal compound buffer layer typified by magnesium fluoride, oxide buffer layer typified by aluminum oxide, etc. . The buffer layer (injection layer) is preferably a very thin film, and the film thickness is preferably in the range of 0.1 nm to 5 μm, depending on the material.

<Blocking layer: hole blocking layer, electron blocking layer>
The blocking layer is provided as necessary in addition to the basic constituent layer of the organic compound thin film as described above. For example, it is described in JP-A Nos. 11-204258, 11-204359, and “Organic EL elements and their forefront of industrialization” (issued by NTT, Inc. on November 30, 1998). There is a hole blocking (hole blocking) layer.

  The hole blocking layer has a function of an electron transport layer in a broad sense, and is made of a hole blocking material that has a function of transporting electrons and has a remarkably small ability to transport holes. The probability of recombination of electrons and holes can be improved by blocking. Moreover, the structure of the electron carrying layer mentioned later can be used as a hole-blocking layer concerning this invention as needed. The hole blocking layer is preferably provided adjacent to the light emitting layer.

  On the other hand, the electron blocking layer has a function of a hole transport layer in a broad sense, and is made of a material that has a function of transporting holes and has an extremely small ability to transport electrons, and transports electrons while transporting holes. By blocking, the recombination probability of electrons and holes can be improved. Moreover, the structure of the positive hole transport layer mentioned later can be used as an electron blocking layer as needed. The film thickness of the hole blocking layer and the electron transport layer according to the present invention is preferably 3 nm or more and 100 nm or less, and more preferably 5 nm or more and 30 nm or less.

《Hole transport layer》
The hole transport layer is made of a hole transport material having a function of transporting holes, and in a broad sense, a hole injection layer and an electron blocking layer are also included in the hole transport layer. The hole transport layer can be provided as a single layer or a plurality of layers.

  The hole transport material has any one of hole injection or transport and electron barrier properties, and may be either organic or inorganic. For example, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, Examples thereof include stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymer oligomers, particularly thiophene oligomers.

  The above-mentioned materials can be used as the hole transport material, but it is preferable to use a porphyrin compound, an aromatic tertiary amine compound and a styrylamine compound, particularly an aromatic tertiary amine compound.

  Representative examples of aromatic tertiary amine compounds and styrylamine compounds include N, N, N ', N'-tetraphenyl-4,4'-diaminophenyl; N, N'-diphenyl-N, N'- Bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine (TPD); 2,2-bis (4-di-p-tolylaminophenyl) propane; 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane; N, N, N ′, N′-tetra-p-tolyl-4,4′-diaminobiphenyl; 1,1-bis (4-di-p-tolyl) Aminophenyl) -4-phenylcyclohexane; bis (4-dimethylamino-2-methylphenyl) phenylmethane; bis (4-di-p-tolylaminophenyl) phenylmethane; N, N'-diphenyl-N, N ' − (4-methoxyphenyl) -4,4'-diaminobiphenyl; N, N, N ', N'-tetraphenyl-4,4'-diaminodiphenyl ether; 4,4'-bis (diphenylamino) quadriphenyl; N, N, N-tri (p-tolyl) amine; 4- (di-p-tolylamino) -4 '-[4- (di-p-tolylamino) styryl] stilbene; 4-N, N-diphenylamino- (2-diphenylvinyl) benzene; 3-methoxy-4'-N, N-diphenylaminostilbenzene; N-phenylcarbazole, as well as two of those described in US Pat. No. 5,061,569 Having a condensed aromatic ring in the molecule, for example, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-308 4,4 ', 4 "-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine in which three triphenylamine units described in Japanese Patent No. 88 are linked in a starburst type ( MTDATA) and the like.

  Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used. In addition, inorganic compounds such as p-type-Si and p-type-SiC can also be used as the hole injection material and the hole transport material.

  JP-A-11-251067, J. Org. Huang et. al. A so-called p-type hole transport material described in a book (Applied Physics Letters, 80 (2002), p. 139) can also be used. In the present invention, it is preferable to use these materials because a light-emitting element with higher efficiency can be obtained.

  The hole transport layer can be formed by thinning the hole transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. it can. Although there is no restriction | limiting in particular about the film thickness of a positive hole transport layer, Usually, 5 nm or more and about 5 micrometers or less, Preferably they are 5 nm or more and 200 nm or less. The hole transport layer may have a single layer structure composed of one or more of the above materials.

  Alternatively, a hole transport layer having a high p property doped with impurities can be used. Examples thereof include JP-A-4-297076, JP-A-2000-196140, 2001-102175, J.A. Appl. Phys. 95, 5773 (2004), and the like.

  In the present invention, it is preferable to use a hole transport layer having such a high p property because a device with lower power consumption can be produced.

《Electron transport layer》
The electron transport layer is made of a material having a function of transporting electrons, and in a broad sense, an electron injection layer and a hole blocking layer are also included in the electron transport layer. The electron transport layer can be provided as a single layer or a plurality of layers.

  Conventionally, in the case of a single electron transport layer and a plurality of layers, an electron transport material (also serving as a hole blocking material) used for an electron transport layer adjacent to the light emitting layer on the cathode side is injected from the cathode. As long as it has a function of transferring electrons to the light-emitting layer, any material can be selected and used from among conventionally known compounds. For example, nitro-substituted fluorene derivatives, diphenylquinone derivatives Thiopyrandioxide derivatives, carbodiimides, fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, oxadiazole derivatives and the like. Furthermore, in the above oxadiazole derivative, a thiadiazole derivative in which the oxygen atom of the oxadiazole ring is substituted with a sulfur atom, and a quinoxaline derivative having a quinoxaline ring known as an electron withdrawing group can also be used as an electron transport material. Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used.

In addition, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (Alq ₃ ), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-quinolinol) Aluminum, tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), etc., and the central metals of these metal complexes are In, Mg Metal complexes replaced with Cu, Ca, Sn, Ga, or Pb can also be used as electron transport materials. In addition, metal-free or metal phthalocyanine, or those having terminal ends substituted with an alkyl group or a sulfonic acid group can be preferably used as the electron transporting material. Further, the distyrylpyrazine derivatives exemplified as the material of the light emitting layer can also be used as the electron transport material, and inorganic semiconductors such as n-type-Si and n-type-SiC can be used as well as the hole injection layer and the hole transport layer. It can be used as an electron transport material.

  The electron transport layer can be formed by thinning the electron transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. Although there is no restriction | limiting in particular about the film thickness of an electron carrying layer, Usually, 5 nm or more and about 5 micrometers or less are preferable, Preferably they are 5 nm or more and 200 nm or less. The electron transport layer may have a single layer structure composed of one or more of the above materials.

  Further, an electron transport layer having a high n property doped with impurities can also be used. Examples thereof include JP-A-4-297076, JP-A-10-270172, JP-A-2000-196140, 2001-102175, J.A. Appl. Phys. 95, 5773 (2004), and the like.

  In the present invention, it is preferable to use an electron transport layer having such a high n property because an element with lower power consumption can be manufactured.

《Support substrate》
There are no particular limitations on the type of glass, plastic, etc., as a support substrate (hereinafter also referred to as a substrate, substrate, substrate, support, etc.) for organic EL elements. Also good. When extracting light from the support substrate side, the support substrate is preferably transparent. Examples of the transparent support substrate preferably used include glass, quartz, and a transparent resin film. A particularly preferable support substrate is a resin film capable of giving flexibility to the organic EL element.

  Examples of the resin film include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene, polypropylene, cellophane, cellulose diacetate, cellulose triacetate, cellulose acetate butyrate, cellulose acetate propionate (CAP), Cellulose esters such as cellulose acetate phthalate and cellulose nitrate or derivatives thereof, polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether ketone, polyimide, polyether Sulfone (PES), polyphenylene sulfide, polysulfones, polyether Examples include cycloolefin resins such as luimide, polyether ketone imide, polyamide, fluororesin, nylon, polymethyl methacrylate, acrylic or polyarylate, Arton (trade name, manufactured by JSR) or Apel (trade name, manufactured by Mitsui Chemicals). It is done.

On the surface of the resin film, an inorganic film, an organic film, or a hybrid film of both may be formed. Water vapor permeability (40 ° C., 90%) measured by a method in accordance with JIS-K-7129-1992. (RH) is preferably a barrier film having a viscosity of 0.01 g / (m ² · day · atm) or less, and further, oxygen permeability (20 ° C., measured by a method according to JIS-K-7126-1992). 100% RH) is preferably a high-barrier film having 10 ⁻³ g / (m ² · day) or less and a water vapor permeability of 10 ⁻³ g / (m ² · day) or less. The oxygen permeability is more preferably 10 ⁻⁵ g / (m ² · day) or less.

  As a material for forming the barrier film, any material may be used as long as it has a function of suppressing entry of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like can be used. Further, in order to improve the brittleness of the film, it is more preferable to have a laminated structure of these inorganic layers and organic material layers. Although there is no restriction | limiting in particular about the lamination | stacking order of an inorganic layer and an organic layer, It is preferable to laminate | stack both alternately several times.

<Method for forming barrier film>
The method for forming the barrier film is not particularly limited. For example, the vacuum deposition method, sputtering method, reactive sputtering method, molecular beam epitaxy method, cluster ion beam method, ion plating method, plasma polymerization method, atmospheric pressure plasma weight A combination method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, and the like can be used, but an atmospheric pressure plasma polymerization method as described in JP-A-2004-68143 is particularly preferable.

  Examples of the opaque support substrate include metal plates / films such as aluminum and stainless steel, opaque resin substrates, ceramic substrates, and the like.

<Sealing>
Examples of the sealing means used for sealing the organic EL element include a method of bonding a sealing member, an electrode, and a support substrate with an adhesive.

  The sealing member may be disposed so as to cover the display area of the organic EL element, and may be concave or flat. Moreover, transparency and electrical insulation are not particularly limited.

  Specifically, a glass plate, a polymer plate, a film, a metal plate, a film, etc. are mentioned. Examples of the glass plate include soda-lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz. Examples of the polymer plate include polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, and polysulfone. Examples of the metal plate include those made of one or more metals or alloys selected from the group consisting of stainless steel, iron, copper, aluminum, magnesium, nickel, zinc, chromium, titanium, molybdenum, silicon, germanium, and tantalum.

In the present invention, a polymer film and a metal film can be preferably used because the element can be thinned. Furthermore, the polymer film preferably has an oxygen permeability of 10 ⁻³ g / (m ² · day) or less and a water vapor permeability of 10 ⁻³ g / (m ² · day) or less. The water vapor permeability and oxygen permeability are more preferably 10 ⁻⁵ g / (m ² · day) or less.

  For processing the sealing member into a concave shape, sandblasting, chemical etching, or the like is used. Specific examples of the adhesive include photocuring and thermosetting adhesives having reactive vinyl groups such as acrylic acid oligomers and methacrylic acid oligomers, and moisture curing adhesives such as 2-cyanoacrylates. be able to. Moreover, heat | fever and chemical curing types (two-component mixing), such as an epoxy type, can be mentioned. Moreover, hot-melt type polyamide, polyester, and polyolefin can be mentioned. Moreover, a cationic curing type ultraviolet curing epoxy resin adhesive can be mentioned.

  In addition, since an organic EL element may deteriorate by heat processing, what can be adhesive-hardened from room temperature to 80 degreeC is preferable. A desiccant may be dispersed in the adhesive. Application | coating of the adhesive agent to a sealing part may use commercially available dispenser, and may print it like screen printing.

  In addition, it is also preferable to coat the electrode and the organic layer on the outside of the electrode facing the support substrate with the organic layer interposed therebetween, and form an inorganic or organic layer in contact with the support substrate to form a sealing film. it can. In this case, the material for forming the film may be any material that has a function of suppressing intrusion of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like may be used. it can. Further, in order to improve the brittleness of the film, it is preferable to have a laminated structure of these inorganic layers and layers made of organic materials. The method for forming these films is not particularly limited. For example, vacuum deposition, sputtering, reactive sputtering, molecular beam epitaxy, cluster ion beam method, ion plating method, plasma polymerization method, atmospheric pressure A plasma polymerization method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used.

  In the gap between the sealing member and the display area of the organic EL element, it is preferable to inject an inert gas such as nitrogen or argon, or an inert liquid such as fluorinated hydrocarbon or silicon oil in the gas phase and the liquid phase. . A vacuum can also be used. Moreover, a hygroscopic compound can also be enclosed inside.

  Examples of the hygroscopic compound include metal oxides (for example, sodium oxide, potassium oxide, calcium oxide, barium oxide, magnesium oxide, aluminum oxide) and sulfates (for example, sodium sulfate, calcium sulfate, magnesium sulfate, cobalt sulfate). Etc.), metal halides (eg calcium chloride, magnesium chloride, cesium fluoride, tantalum fluoride, cerium bromide, magnesium bromide, barium iodide, magnesium iodide etc.), perchloric acids (eg perchloric acid) Barium, magnesium perchlorate, and the like), and anhydrous salts are preferably used in sulfates, metal halides, and perchloric acids.

《Protective film, protective plate》
In order to increase the mechanical strength of the element, a protective film or a protective plate may be provided on the outer side of the sealing film on the side facing the support substrate with the organic layer interposed therebetween or on the sealing film. In particular, when the sealing is performed by the sealing film, the mechanical strength is not necessarily high, and thus it is preferable to provide such a protective film and a protective plate. As a material that can be used for this, the same glass plate, polymer plate / film, metal plate / film, etc. used for the sealing can be used, but the polymer film is light and thin. Is preferably used.

"electrode"
The surface light emitting device according to the present invention has at least a first electrode and a second electrode. When an organic EL element is used, one is usually composed of an anode and the other is a cathode. The preferred anode and cathode configurations are described below.

"anode"
As the anode in the organic EL element, an electrode material made of a metal, an alloy, an electrically conductive compound, or a mixture thereof having a high work function (4 eV or more) is preferably used. Specific examples of such electrode substances include metals such as Au, and conductive light-transmitting materials such as CuI, indium tin oxide (ITO), SnO ₂ , and ZnO. Alternatively, a material such as IDIXO (In ₂ O ₃ —ZnO) that can form an amorphous light-transmitting conductive film may be used. For the anode, these electrode materials may be formed into a thin film by a method such as vapor deposition or sputtering, and a pattern having a desired shape may be formed by a photolithography method, or when the pattern accuracy is not required (about 100 μm or more) ), A pattern may be formed through a mask having a desired shape when the electrode material is deposited or sputtered. Or when using the substance which can be apply | coated like an organic electroconductivity compound, wet film forming methods, such as a printing system and a coating system, can also be used. The sheet resistance as the anode is preferably several hundred Ω / □ or less. Further, although the film thickness depends on the material, it is usually selected in the range of 10 nm to 1000 nm, preferably 10 nm to 200 nm.

"cathode"
On the other hand, as the cathode, a material having a low work function (4 eV or less) metal (referred to as an electron injecting metal), an alloy, an electrically conductive compound, and a mixture thereof as an electrode material is used. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al ₂ O ₃ ) Mixtures, indium, lithium / aluminum mixtures, rare earth metals and the like.

Among these, from the point of durability against electron injection and oxidation, etc., a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function than this, for example, a magnesium / silver mixture, Magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / aluminum oxide (Al ₂ O ₃ ) mixtures, lithium / aluminum mixtures, aluminum and the like are preferred. The cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering. The sheet resistance as the cathode is preferably several hundred Ω / □ or less, and the film thickness is usually selected in the range of 10 nm to 5 μm, preferably 50 nm to 200 nm.

  In order to transmit the emitted light, either the anode or the cathode of the organic EL element is configured to be light transmissive.

  In the surface light emitting device of the present invention, when an organic EL device is used, the first electrode and the second electrode can be arbitrarily arranged with the light emitting layer interposed therebetween.

  In the present invention, the light-impermeable region may be light-absorbing or light-reflective, but is preferably light-reflective. In the case of light absorption, graphite or the like can be preferably used, and in the case of light reflection, aluminum and aluminum compounds, silver and silver compounds, or the like can be preferably used.

  In the present invention, for example, after the conductive material is formed thinly at a thickness of 1 nm to 20 nm on the cathode, the conductive light-transmitting material mentioned in the description of the anode is formed thereon, thereby injecting electrons. It is possible to produce a cathode having both optical properties and light transmittance.

  The second electrode according to the present invention may be formed by laminating a light-impermeable film at a location corresponding to the central portion of the light-emitting region on the light-transmitting film, forming a light-impermeable film at the central portion of the light-emitting region, A structure in which a light transmissive film is provided around the periphery may also be used. In the case where a conductive light-transmitting film is used, an insulating light-impermeable film can be stacked.

<< Method for producing organic EL element >>
As an example of a method for producing an organic EL element, a method for producing an organic EL element comprising an anode / hole injection layer / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode will be described.

  First, a desired electrode material, for example, a thin film made of an anode material is formed on a suitable support substrate by a method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably 10 nm or more and 200 nm or less, and an anode is manufactured. To do. Next, an organic compound thin film of a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, and an electron transport layer, which are organic EL element materials, is formed thereon.

As a method for thinning the organic compound thin film, there are a vapor deposition method and a wet process (spin coating method, casting method, ink jet method, printing method) as described above, but it is easy to obtain a uniform film and a pinhole. From the point of being difficult to form, a vacuum deposition method, a spin coating method, an ink jet method, and a printing method are particularly preferable. Further, a different film forming method may be applied for each layer. When a vapor deposition method is employed for film formation, the vapor deposition conditions vary depending on the type of compound used, but generally a boat heating temperature of 50 to 450 ° C., a vacuum degree of 10 ^{−6 to} 10 ⁻² Pa and a vapor deposition rate of 0. It is desirable to select appropriately within the range of 01 nm / second to 50 nm / second, substrate temperature −50 ° C. to 300 ° C., film thickness 0.1 nm to 5 μm, preferably 5 nm to 200 nm.

  After these layers are formed, a thin film made of a cathode material is formed thereon by a method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably 50 nm or more and 200 nm or less. By providing, a desired organic EL element can be obtained. The organic EL element is preferably produced from the hole injection layer to the cathode consistently by a single evacuation, but may be taken out halfway and subjected to different film forming methods. At that time, it is necessary to consider that the work is performed in a dry inert gas atmosphere.

  In addition, it is also possible to reverse the production order and produce the cathode, the electron injection layer, the electron transport layer, the light emitting layer, the hole transport layer, the hole injection layer, and the anode in this order. When a DC voltage is applied to the multicolor liquid crystal display device thus obtained, light emission can be observed by applying a voltage of about 2 V or more and 40 V or less with the positive polarity of the anode and the negative polarity of the cathode. An alternating voltage may be applied. The alternating current waveform to be applied may be arbitrary.

  An organic EL element emits light within a layer having a refractive index higher than that of air (refractive index: 1.6 to 2.1), and only 15% to 20% of light generated in the light emitting layer can be extracted. It is generally said that there is no. This is because light incident on the interface (interface between the transparent substrate and air) at an angle θ greater than the critical angle causes total reflection and cannot be extracted outside the device, or between the transparent electrode or light emitting layer and the transparent substrate. This is because the light undergoes total reflection between the light and the light, and the light is guided through the transparent electrode or the light emitting layer.

  As a method for improving the light extraction efficiency, for example, a method of forming irregularities on the surface of the transparent substrate to prevent total reflection at the interface between the transparent substrate and the air (for example, US Pat. No. 4,774,435). ), A method of improving the efficiency by giving the substrate a light condensing property (for example, JP-A-63-314795), a method of forming a reflective surface on the side surface of the element (for example, JP-A-1-220394) Gazette), a method of forming an antireflection film by introducing a flat layer having an intermediate refractive index between the substrate and the light emitter (for example, Japanese Patent Application Laid-Open No. 62-172691), and a substrate between the substrate and the light emitter. A method of introducing a flat layer having a lower refractive index than that (for example, Japanese Patent Application Laid-Open No. 2001-202827), a diffraction grating between any one of the substrate, the transparent electrode layer and the light emitting layer (including between the substrate and the outside). Method of forming There is 1-283751 JP), and the like.

  In the present invention, these methods can be used in combination, but either a method of introducing a flat layer having a lower refractive index than the substrate between the substrate and the light emitter, or any of the substrate, the transparent electrode layer, and the light emitting layer. A method of forming a diffraction grating between the layers (including between the substrate and the outside) can be suitably used. In the present invention, by combining these means, it is possible to obtain an element having higher luminance or durability.

  When a medium having a low refractive index is formed between the transparent electrode and the transparent substrate with a thickness longer than the wavelength of light, the light extracted from the transparent electrode has a higher extraction efficiency to the outside as the refractive index of the medium is lower.

  Examples of the low refractive index layer include aerogel, porous silica, magnesium fluoride, and a fluorine-based polymer. Since the refractive index of the transparent substrate is generally about 1.5 or more and 1.7 or less, the low refractive index layer preferably has a refractive index of about 1.5 or less. Furthermore, it is preferable that it is 1.35 or less.

  The thickness of the low refractive index medium is preferably at least twice the wavelength in the medium. This is because the effect of the low-refractive index layer is reduced when the thickness of the low-refractive index medium is about the wavelength of light and the electromagnetic wave exuded by evanescent enters the substrate.

  The method of introducing a diffraction grating into an interface or any medium that causes total reflection is characterized by a high effect of improving light extraction efficiency. This method uses the property that the diffraction grating can change the direction of light to a specific direction different from refraction by so-called Bragg diffraction, such as first-order diffraction and second-order diffraction. Among them, light that cannot be emitted due to total reflection between layers, etc. is diffracted by introducing a diffraction grating into any layer or medium (in a transparent substrate or transparent electrode), and the light is emitted outside. I want to take it out.

  It is desirable that the diffraction grating to be introduced has a two-dimensional periodic refractive index. This is because light emitted from the light-emitting layer is randomly generated in all directions, so in a general one-dimensional diffraction grating having a periodic refractive index distribution only in a certain direction, only light traveling in a specific direction is diffracted. The light extraction efficiency does not increase so much. However, by making the refractive index distribution a two-dimensional distribution, light traveling in all directions is diffracted, and light extraction efficiency is increased.

  The position where the diffraction grating is introduced may be in any one of the layers or in the medium (in the transparent substrate or the transparent electrode) as described above, but is preferably in the vicinity of the organic light emitting layer where light is generated.

  At this time, the period of the diffraction grating is preferably about 1/2 to 3 times the wavelength of light in the medium. The arrangement of the diffraction grating is preferably two-dimensionally repeated such as a square lattice, a triangular lattice, or a honeycomb lattice.

  The surface light emitting device of the present invention is processed to provide a structure on the microlens array, for example, on the light extraction side of the support substrate, or is combined with a so-called light collecting sheet, for example, in a specific direction, for example, the device light emitting surface. On the other hand, the brightness | luminance in a specific direction can be raised by condensing in a front direction.

  As an example of the microlens array, quadrangular pyramids having a side of 30 μm and an apex angle of 90 degrees are two-dimensionally arranged on the light extraction side of the substrate. One side is preferably 10 to 100 μm. If it becomes smaller than this, the effect of diffraction will generate | occur | produce and color, and if too large, thickness will become thick and is not preferable.

  As the condensing sheet, for example, a sheet that is put into practical use in an LED backlight of a liquid crystal display device can be used. As such a sheet, for example, a brightness enhancement film (BEF) manufactured by Sumitomo 3M Limited can be used. As the shape of the prism sheet, for example, the base material may be formed by forming a △ -shaped stripe having a vertex angle of 90 degrees and a pitch of 50 μm, or the vertex angle is rounded and the pitch is changed randomly. Other shapes may be used.

  Moreover, in order to control the light emission angle from a light emitting element, you may use together a light diffusing plate and a film with a condensing sheet. For example, a diffusion film (light-up) manufactured by Kimoto Co., Ltd. can be used.

  When the light emitting panel is configured by arranging a plurality of the surface light emitting elements of the present invention so that part of the light emitting region of the surface light emitting element viewed from the light emitting surface vertical direction overlaps each other, An adhesive and an adhesive can be used.

  The pressure-sensitive adhesive in the present invention is widely used in the industrial field, among pressure-sensitive adhesives, adhesives, or agents or materials used in designations such as pressure-sensitive adhesives, adhesives, etc. It means something that is not accompanied.

  Although the kind of adhesive and adhesive is not specifically limited, It is preferable to use the adhesive and adhesive excellent in light transmittance. As the adhesive, a curable adhesive that forms a high molecular weight body or a crosslinked structure by various chemical reactions after being applied and bonded is suitably used. Specific examples of pressure-sensitive adhesives and adhesives that can be used in the present invention include, for example, urethane-based, epoxy-based, aqueous polymer-isocyanate-based, acrylic-based curable adhesives and pressure-sensitive adhesives, and moisture-cured urethane adhesives. And anaerobic pressure-sensitive adhesives such as polyether methacrylate type, ester type methacrylate type and oxidized type polyether methacrylate, cyanoacrylate type instantaneous adhesive, acrylate and peroxide type two liquid type instantaneous adhesive, and the like.

  The method for forming the pressure-sensitive adhesive layer and the adhesive layer on the element laminate is not particularly limited, and a general method such as a gravure coater, a micro gravure coater, a comma coater, a bar coater, a spray coating, an ink jet method, or the like. Is mentioned.

  Further, in the light emitting panel of the present invention, a gap between the plurality of surface light emitting elements may be filled with an inorganic material such as glass or silica, a resin, a pressure sensitive adhesive, an adhesive, or the like. Transparent resins such as PET (polyethylene terephthalate), TAC (triacetyl cellulose), PC (polycarbonate), or PMMA (polymethyl methacrylate), and adhesives such as urethane, epoxy, aqueous polymer-isocyanate, and acrylic Agents, anaerobic pressure-sensitive adhesives such as polyether methacrylate type, ester type methacrylate type, oxidized type polyether methacrylate and the like, and urethane type, epoxy type, aqueous polymer-isocyanate type, acrylic type curable adhesives, etc. Furthermore, various UV curable resins, thermosetting resins, and the like can be used. Further, a light scattering material and a light reflecting material can be filled. Moreover, you may comprise a light emission panel on another support substrate.

<Application>
The surface light emitting device and the light emitting panel of the present invention can be used as a display device, a display, and various light emitting light sources. Examples of light sources include home lighting, interior lighting, clock and liquid crystal backlights, billboard advertisements, traffic lights, light sources for optical storage media, light sources for electrophotographic copying machines, light sources for optical communication processors, and light sources for optical sensors. Etc. Although it is not limited to this, it can be effectively used particularly as a backlight of a liquid crystal display device combined with a color filter and a light source for illumination.

  When used as a backlight of a display in combination with a color filter, it is preferably used in combination with a light collecting sheet in order to further increase the luminance.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

<< Fabrication of surface light emitting element >>
[Fabrication of Surface Light Emitting Element 101: Comparative Example]
After patterning a support substrate in which ITO (indium tin oxide) was deposited to a thickness of 120 nm on a glass substrate of 30 mm × 30 mm and a thickness of 0.7 mm as a first electrode (anode), this ITO transparent electrode The transparent support substrate attached with is ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and after UV ozone cleaning for 5 minutes, this transparent support substrate is connected to a commercially available vacuum deposition apparatus in a plasma processing chamber. Fixed to the substrate holder. In addition, each of the vapor deposition crucibles in the vacuum vapor deposition apparatus was filled with an optimum amount of the constituent material of each layer for device fabrication. The evaporation crucible used was made of a resistance heating material made of molybdenum or tungsten.

After performing plasma treatment for 2 minutes at an oxygen pressure of 1 Pa and an electric power of 100 W (electrode area of about 450 cm ² ), the substrate was transferred to an organic layer deposition chamber without being exposed to the atmosphere, and an organic layer was formed.

First, after reducing the vacuum to 1 × 10 ⁻⁴ Pa, the deposition crucible containing m-MTDATA was energized and heated, and deposited on a transparent support substrate at a deposition rate of 0.1 nm / second. A hole injection layer was provided. Next, α-NPD was vapor-deposited in the same manner to provide a 30 nm hole transport layer.

  Next, each light emitting layer was sequentially provided in the following procedure.

  Compounds D-3 and H-1 were co-evaporated at a deposition rate of 0.1 nm / second so that D-3 would have a concentration of 9% by mass, and a blue phosphorescence emission having an emission maximum wavelength of 470 nm and a thickness of 20 nm. A layer was formed. Next, compounds D-1 and CBP were co-evaporated at a deposition rate of 0.1 nm / second so that D-1 would have a concentration of 5% by mass, and a green phosphorescent light emitting layer having an emission maximum wavelength of 518 nm and a thickness of 5 nm. Formed. Next, compounds D-2 and CBP were co-evaporated at a deposition rate of 0.1 nm / second so that D-2 had a concentration of 8% by mass, and a red phosphorescent emitting layer having an emission maximum wavelength of 622 nm and a thickness of 5 nm. Formed. Thereafter, Compound M-1 is vapor-deposited to a thickness of 10 nm to form a hole blocking layer, and CsF is co-deposited with Compound M-1 so that the film thickness ratio is 10%. A layer was formed. Furthermore, aluminum 110nm was vapor-deposited, the 2nd electrode (cathode) was formed, and the white organic EL element was produced.

  Next, the non-light-emitting surface of the organic EL element was covered with a glass case to obtain a surface light-emitting element 101.

  FIG. 14 is a cross-sectional view of the surface light emitting element 101, and the organic EL element is covered with a glass cover 103. The sealing operation with the glass cover was performed in a glove box (in an atmosphere of high-purity nitrogen gas having a purity of 99.999% or more) in a nitrogen atmosphere without bringing the organic EL element into contact with the atmosphere. In FIG. 14, 104 is a glass substrate, 105 is a second electrode, 106 is a functional layer including an organic EL light emitting layer, and 107 is a first electrode. The glass cover 103 is filled with nitrogen gas 108 and a water catching agent 109 is provided. The glass cover 103 is bonded to the glass substrate 104 using a UV curable resin 110. Although not shown in the drawing, wiring connection portions of the first electrode (anode) and the second electrode (cathode) for connecting a plurality of surface light emitting elements are provided in the UV curable resin 110 portion. In the surface light emitting element 101, the first electrode 107 is light transmissive, and the second electrode 105 is light reflective.

[Fabrication of Surface Light Emitting Element 102: Present Invention]
In the fabrication of the surface light emitting device 101, after forming an electron transport layer, a silver paste is deposited to 10 nm, then ITO is deposited to 100 nm, and the mask is replaced to resemble a light emitting region shape (square) and By depositing 100 nm of aluminum on a region corresponding to 85% of the light emitting region area so that the center of the light emitting region and the center of the light reflecting region overlap, the central portion of the light emitting region is light reflective and the periphery of the light emitting region A second electrode (cathode) having a light-transmitting part was formed to produce an organic EL element.

  Next, similarly to the surface light emitting device 101, the non-light emitting surface of the organic EL device was covered with a glass case to obtain a surface light emitting device 102.

[Fabrication of Surface Light Emitting Element 103: Present Invention]
In the fabrication of the surface light emitting device 101, after forming an electron transport layer, a silver paste was deposited to 10 nm, then ITO was deposited to 100 nm, and the mask was replaced, and the area of the circular and square light emitting region was 78. By depositing 100 nm of aluminum so that the center of the light-emitting region and the center of the light-reflecting region overlap each other in a region corresponding to 0.5%, the center of the light-emitting region is light-reflective and the light-emitting region periphery is light. A transparent second electrode (cathode) was formed to produce an organic EL element.

  Next, similarly to the surface light emitting device 101, the non-light emitting surface of this organic EL device was covered with a glass case to obtain a surface light emitting device 103.

  FIG. 15 shows a cross-sectional view of the surface light emitting elements 102 and 103. The organic EL element is covered with a glass cover 103. The sealing operation with the glass cover was performed in a glove box (in an atmosphere of high-purity nitrogen gas having a purity of 99.999% or more) in a nitrogen atmosphere without bringing the organic EL element into contact with the atmosphere. In FIG. 15, reference numeral 104 denotes a glass substrate, 105 denotes a second electrode, 106 denotes a functional layer including an organic EL light emitting layer, and 107 denotes a first electrode. The second electrode 105 is composed of a light-reflective central portion 111 and a light-transmissive peripheral portion 112. The glass cover 103 is filled with nitrogen gas 108 and a water catching agent 109 is provided. The glass cover 103 is bonded to the glass substrate 104 using a UV curable resin 110. Although not shown in the drawing, wiring connection portions of the first electrode (anode) and the second electrode (cathode) for connecting a plurality of surface light emitting elements are provided in the UV curable resin 110 portion. 16A is a view of the second electrode 105 of the surface light emitting element 102, and FIG. 16B is a view of the second electrode 105 of the surface light emitting element 103 as viewed from the direction perpendicular to the light emitting surface. The shapes of the central part 111 and the light-transmitting peripheral part 112 are respectively shown.

[Production of Light-Emitting Panel 1: Comparative Example]
Five surface light-emitting elements 101 are manufactured, and these are pasted on a common glass substrate 113 with a light-transmitting UV curable resin as shown in FIGS. 18A and 18B, so that the light-emitting panel 1 is manufactured. did. FIG. 17 is a simplified side view of the individual surface light emitting elements 101 constituting the light emitting panel. The surface light emitting elements are formed on the substrate 104. FIG. 17 shows only the glass cover 103, the second electrode 105, the functional layer 106 including the organic EL light emitting layer, and the first electrode 107.

  18A is a diagram illustrating the light-emitting panel 1 viewed from the direction perpendicular to the light emitting surface, and FIG. 18B is a side view of the light-emitting panel 1. In addition, although not shown in figure, each surface light emitting element was electrically connected in series and the space | interval of each surface light emitting element needed 5 mm in order to ensure the wiring between surface light emitting elements.

[Production of Light-Emitting Panel 2: Present Invention]
As shown in FIGS. 20A and 20B, five surface light emitting elements 102 are manufactured, and are pasted on a common glass substrate 113 with a light transmissive UV curable resin, thereby manufacturing the light emitting panel 2. did. FIG. 19 is a simplified side view of the individual surface light emitting elements 101 constituting the light emitting panel. The surface light emitting elements are formed on the substrate 104. FIG. 19 shows only the glass cover 103, the second electrode 105, the functional layer 106 including the organic EL light emitting layer, and the first electrode 107. The second electrode 105 is composed of a light-reflective central portion 111 and a light-transmissive peripheral portion 112. 20A is a diagram showing the light emitting panel 2 viewed from the direction perpendicular to the light emitting surface, and FIG. 20B is a side view of the light emitting panel 2. FIG. The connection portion of each surface light emitting element is a light transmitting peripheral portion 112 of the second electrode which is a part of the light emitting region of one surface light emitting element, and a second part which is a part of the light emitting region of the other surface light emitting element. The light transmitting peripheral portion 112 of the electrode is disposed so as to overlap each other. The space between the surface light emitting element and the common glass substrate 113 is filled with a light transmissive UV curable resin, and the surface light emitting elements are electrically connected in series.

[Production of Light-Emitting Panel 3: Present Invention]
Five surface light emitting elements 103 were produced, and these were pasted on a common glass substrate 113 with a light transmissive UV curable resin as shown in FIGS. 21A to 21C to produce a light emitting panel 3. . 21A is a view showing the light-emitting panel 3 viewed from the direction perpendicular to the light emitting surface, and FIG. 21B is a cross-sectional view of the light-emitting panel 3 taken along the line AA ′ of FIG. 21A. FIG. In the A-A ′ portion, the connection portion of each surface light emitting element is a part of the light reflective central portion 111 of the second electrode of one surface light emitting element and the light of the second electrode of the other surface light emitting element. A part of the reflective central portion 111 is disposed so as to overlap each other. FIG. 21C is a cross-sectional view of the luminescent panel 3 taken along the line BB ′ of FIG. In the BB ′ portion, the connection portion of each surface light emitting element includes a part of the light transmissive peripheral portion 112 of the second electrode, which is a part of the light emitting region of one surface light emitting element, and the other surface light emission. A part of the light transmissive peripheral portion 112 of the second electrode, which is a part of the light emitting region of one surface light emitting element of the element, is disposed so as to overlap each other. The space between the surface light emitting element and the common glass substrate 113 is filled with a light transmissive UV curable resin, and the surface light emitting elements are electrically connected in series.

[Evaluation of light emitting panels 1 to 3]
The light emitting panels 1 to 3 were arranged side by side to emit light and compared visually.

  The light-emitting panel 1 is clearly inferior in visibility because the non-light-emitting area exists as a wide area between adjacent light-emitting areas. On the other hand, in the light emitting panel 3, the luminance reduction at the element connection portion was considerably improved. The light emitting panel 2 was most excellent in visibility, with almost no decrease in luminance at the element connection portion.

[Production of Light-Emitting Panel 4: Comparative Example]
Using 15 surface light-emitting elements 101, as shown in FIG. 22, light is transmissive on a common glass substrate 113 in a 3 × 5 matrix of 3 in the vertical direction and 5 in the horizontal direction. The light emitting panel 4 was prepared by pasting with a UV curable resin. Each of the surface light-emitting elements was electrically connected in series in the row direction, and then 15 surface light-emitting elements were connected in series by sequentially connecting them in the column direction. In order to secure wiring between the surface light emitting elements, the interval between the surface light emitting elements required 5 mm.

[Production of Light-Emitting Panel 5: Present Invention]
Using 15 surface light emitting elements 102, as shown in FIGS. 23 (a) to 23 (c), a common 3 × 5 matrix with 3 in the vertical direction and 5 in the horizontal direction in the plane is used. The light emitting panel 5 was produced by pasting the glass substrate 113 with a light transmissive UV curable resin. FIG. 23A is a diagram showing the light emitting panel 5 viewed from the direction perpendicular to the emission surface, and FIG. 23B is an AA ′ portion in the XX ′ direction of the light emitting panel 5 and CC. FIG. 23C is a cross-sectional view of the BB ′ portion in the XX ′ direction of the light emitting panel 5. 23D is a cross-sectional view of the DD ′ portion, the FF ′ portion, and the HH ′ portion in the YY ′ direction of the light emitting panel 5, and FIG. 23E is a light emitting panel. 5 is a cross-sectional view of the EE ′ portion and the GG ′ portion in the YY ′ direction of FIG. The connection part of each surface light emitting element is the light transmitting peripheral part of the second electrode which is a part of the light emitting region of one surface light emitting element, and the light of the second electrode which is a part of the light emitting region of the other surface light emitting element. The transparent peripheral portion is arranged so as to overlap each other. The gap between the surface light emitting element and the common glass substrate 113 is filled with a light transmissive UV curable resin, and each surface light emitting element is electrically connected in series like the light emitting panel 4.

[Evaluation of light-emitting panels 4 and 5]
The light emitting panels 4 and 5 were lit side by side and compared visually.

  The light-emitting panel 4 is clearly inferior in visibility because it is a non-light-emitting region between adjacent light-emitting regions, whereas the light-emitting panel 5 has almost no decrease in luminance at the element connection portion, and the visibility is low. It was excellent.

  As mentioned above, although embodiment of this invention was described, the example mentioned above does not limit this invention. Various modifications and other embodiments are possible in the art within the technical scope and the technical idea of the present invention.

It is sectional drawing of the surface light emitting element of this invention. It is the figure which looked at the 2nd electrode in the light emission area | region of the surface light emitting element of this invention from the light-projection surface perpendicular | vertical direction. It is a figure which shows the example of the other shape of the 2nd electrode which concerns on this invention. It is a figure which shows the example of the other shape of the 2nd electrode which concerns on this invention. It is a figure which shows the example of the other shape of the 2nd electrode which concerns on this invention. It is a figure which shows the example of the other shape of the 2nd electrode which concerns on this invention. It is a figure which shows the example of the shape of the surface emitting element of this invention. It is a figure which shows the example of the light emission panel comprised by arrange | positioning two or more so that a part of light emission area | region of the surface emitting element of the surface emitting element of this invention seen from the light emission surface perpendicular | vertical direction may mutually overlap. It is a figure which shows the example of the light emission panel comprised by arrange | positioning two or more so that a part of light emission area | region of the surface emitting element of the surface emitting element of this invention seen from the light emission surface perpendicular | vertical direction may mutually overlap. It is a figure which shows the example of the light emission panel comprised by arrange | positioning two or more so that a part of light emission area | region of the surface emitting element of the surface emitting element of this invention seen from the light emission surface perpendicular | vertical direction may mutually overlap. It is a figure which shows the other example of the light emission panel comprised by arrange | positioning two or more so that a part of light emission area | region of the surface emitting element of the surface emitting element of this invention seen from the light emission surface perpendicular | vertical direction may mutually overlap. . It is a figure which shows the other example of the light emission panel comprised by arrange | positioning two or more so that a part of light emission area | region of the surface emitting element of the surface emitting element of this invention seen from the light emission surface perpendicular | vertical direction may mutually overlap. . The first electrode side of one surface light emitting element and the second electrode side of another surface light emitting element are arranged so as to face each other, and a part of the light emitting region of one surface light emitting element and the other It is a figure which shows the example of the enlarged view which looked at the light emission panel by which the peripheral part of the 2nd electrode of this surface light emitting element has mutually overlapped and was seen from the side surface direction with respect to the light emission surface perpendicular | vertical direction. It is sectional drawing of the surface light emitting element of this invention. It is sectional drawing of each surface emitting element which comprises a light emission panel. It is the 2nd electrode of the light emission panel seen from the light emission surface perpendicular | vertical direction. It is a side view of each surface emitting element which comprises a light emission panel. It is the light emission panel seen from the light emission surface perpendicular | vertical direction, and a side view. It is a side view of each surface emitting element which comprises a light emission panel. It is the light emission panel seen from the light emission surface perpendicular | vertical direction, and a side view. It is the light emission panel and sectional drawing seen from the light emission surface perpendicular | vertical direction. It is the light emission panel seen from the light emission surface perpendicular | vertical direction. It is the light emission panel and sectional drawing seen from the light emission surface perpendicular | vertical direction.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Board | substrate 2,107 1st electrode 3 Functional layer containing a light emitting layer 4,105 2nd electrode 5 Light-opaque center part 6,112 Light-transmissive periphery part 7 Sealing cover 8,109 Water catching agent 9, 108 Nitrogen gas 10 Light emitting layer 11, 12, 101, 102 Surface light emitting element 103 Glass cover 104, 113 Glass substrate 106 Functional layer including organic EL light emitting layer 110 UV curable resin 111 Light reflecting central portion

Claims (4)

A surface light emitting device having a light emitting layer between at least a first electrode and a second electrode, wherein the first electrode is a light transmissive electrode, and the second electrode is in a direction perpendicular to the light emitting surface of the surface light emitting device. A surface light emitting device comprising: a light-transmitting central portion and a light-transmitting peripheral portion in a light-emitting region viewed from above. The surface light-emitting element according to claim 1, wherein the surface light-emitting element is an organic electroluminescence element. A plurality of the surface light emitting elements according to claim 1 or 2, wherein a plurality of light emitting regions of the surface light emitting elements as viewed from the direction perpendicular to the light emitting surface are arranged so as to overlap each other. . 4. The light emitting panel according to claim 3, wherein a part of a light emitting region of one surface light emitting element and a peripheral portion of a second electrode of another surface light emitting element are arranged to overlap each other.

Images