JP5706736B2 - Organic electroluminescence device, organic electroluminescence unit and lighting apparatus - Google Patents

Description

  The present invention relates to an organic electroluminescent element, an organic electroluminescent unit using the same, and a lighting fixture.

  Conventionally, various types of organic electroluminescent elements (hereinafter, appropriately referred to as organic electroluminescent elements or organic EL elements) have been proposed.

  For example, as shown in FIG. 14, the organic EL element A described in Patent Document 1 includes an organic light emitting layer 52 provided between a first electrode 50 and a second electrode 51 on a substrate 49. The light emitting area 53 corresponding to 52 includes a first area 53a and a second area 53b.

JP 2006-253302 A

  However, the organic EL element A described in Patent Document 1 includes a plurality of terminal portions 50a and 50b of the first electrode 50 and terminal portions 51a and 51b of the second electrode 51 concentrated on one side of the substrate 12. When the organic EL elements A were juxtaposed, there was a problem that the connection between the organic EL elements A was difficult. Further, since the cathode film bonding area to the terminal portions 51a and 51b of the second electrode 51 (minus electrode) is small, if a high current is applied for high-luminance lighting like illumination, electromigration is likely to occur, and conduction reliability There was a problem that the property was easily lowered.

  The present invention has been made in view of the above points, and an object of the present invention is to provide an organic electroluminescence element and an organic electroluminescence unit and a lighting fixture that can be easily connected and can improve conduction reliability. is there.

  In the organic electroluminescent device according to the present invention, the first electrode and the second electrode are formed on the surface of the substrate, the organic layer is formed on the surface of the first electrode, the surface of the organic layer and the second electrode An organic electroluminescent element having a cathode layer formed over a surface thereof, wherein the second electrode is formed along one side of the surface of the substrate, and the first electrode is formed on a side other than the one side of the surface of the substrate. It is characterized by being formed along.

  The organic electroluminescent element has a dimension between one side opposite to the second electrode side of the cathode layer and one side opposite to the second electrode side of the substrate, d1, The dimension between one side on the second electrode side and one side on the second electrode side of the substrate is d3, one side in a direction perpendicular to the one side on the second electrode side of the cathode layer, and the first side of the substrate When the dimension between one side on the two-electrode side and one side in a direction perpendicular to the two electrodes is d2, it is preferably formed so as to satisfy the relationship of d1 + d3 = 2 × d2.

  In the organic electroluminescent element, it is preferable that a third electrode having a lower volume resistance than the first electrode is provided on the first electrode.

  In the organic electroluminescent element, it is preferable that the third electrode is formed up to one side of the first electrode facing the second electrode.

  The organic electroluminescent element is preferably formed by aligning the end face of the first electrode and the end face of the substrate.

  The organic electroluminescent unit according to the present invention is an organic electroluminescent unit in which two or more organic electroluminescent elements are electrically connected, and the adjacent organic electroluminescent element is connected to an end on the second electrode side. The first electrodes are electrically connected to each other at end portions in the orthogonal direction.

  The lighting fixture according to the present invention is a lighting fixture in which two or more of the organic electroluminescence units are electrically connected, and the adjacent organic electroluminescence unit includes a second electrode of one of the organic electroluminescence units. The other organic electroluminescence unit is electrically connected to the first electrode on the opposite side to the second electrode side.

  The lighting fixture is a conductive material that electrically connects the second electrode of one of the organic electroluminescent units and the first electrode on the side opposite to the second electrode of the other organic electroluminescent unit. Is preferably light-reflective.

  The organic electroluminescent element and the organic electroluminescent unit of the present invention are easy to connect and can improve conduction reliability.

  The lighting fixture of this invention can improve conduction | electrical_connection reliability.

An example of embodiment of the organic electroluminescent element of this invention is shown, (a) is a top view, (b) is XX 'sectional drawing of (a). The board | substrate same as the above, a 1st electrode, and a 2nd electrode are shown, (a) is a top view, (b) is XX 'sectional drawing of (a). The board | substrate same as the above, a 1st electrode, a 2nd electrode, and an organic layer are shown, (a) is a top view, (b) is XX 'sectional drawing of (a). An example of other embodiment of the organic electroluminescent element of this invention is shown, (a) is a top view, (b) is XX 'sectional drawing of (a), (c) is Y-- of (a). It is Y 'sectional drawing. An example of other embodiment of the organic electroluminescent element of this invention is shown, (a) is a top view, (b) is XX 'sectional drawing of (a), (c) is Y-- of (a). It is Y 'sectional drawing. The board | substrate same as the above, a 1st electrode, a 2nd electrode, and a 3rd electrode are shown, (a) is a top view, (b) is XX 'sectional drawing of (a). It is a top view which shows an example of other embodiment of the organic electroluminescent element of this invention. A part of the above is shown, and (a) to (c) are plan views. An example of other embodiment of the organic electroluminescent element of this invention is shown, (a) And (b) is sectional drawing. A part of the above is shown, and (a) and (b) are sectional views. It is a top view which shows an example of embodiment of the organic electroluminescent unit of this invention. It is a top view which shows an example of embodiment of the lighting fixture of this invention. It is sectional drawing which shows a part same as the above. It is a top view which shows a prior art example.

  Hereinafter, modes for carrying out the present invention will be described.

  An example of the organic EL element A is shown in FIGS. The organic EL element A includes a substrate 1, a first electrode 2, a second electrode 3, an organic layer 4, and a cathode layer 5.

  The substrate 1 has a light-transmitting translucency, for example, a soda-lime glass or a non-alkali glass transparent glass plate, or a plastic made from polyester, polyolefin, polyamide, epoxy resin, or fluorine resin. It is formed using at least one selected from a film or a plastic plate. The substrate 1 is formed in a rectangular shape such as a square or a rectangle in plan view. Although the thickness of the board | substrate 1 is not specifically limited, For example, it can be referred to as 0.1 mm-2.0 mm.

The first electrode 2 has a light-transmitting property, and functions as an electrode (anode) for injecting holes into the organic layer 4. The first electrode 2 is, for example, metal such as gold, CuI, ITO (indium - tin _oxide), SnO 2, ZnO, IZO (indium - zinc oxide) and, PEDOT, polyaniline conductive polymer, any It is formed using at least one selected from a conductive polymer doped with an acceptor, a carbon nanotube conductive light-transmitting material, and the like. The first electrode 2 can be laminated by, for example, vacuum deposition, sputtering, coating, or the like. Although the thickness of the 1st electrode 2 is not specifically limited, For example, it can be referred to as 10 nm-300 nm.

The second electrode 3 is an electrode (cathode) for injecting electrons into the organic layer 4 through the cathode layer 5. As the second electrode 3, for example, may be used the same material as the first electrode 2, ITO (indium - tin _oxide), SnO 2, ZnO, IZO (indium - zinc oxide) and, PEDOT, a conductive polyaniline Conductive polymer, conductive polymer doped with an arbitrary acceptor, conductive light-transmitting material of carbon nanotube, and the like. Alternatively, a metal such as aluminum, silver, gold, copper, chromium, molybdenum, aluminum, palladium, tin, lead, or magnesium, or an alloy containing at least one of these metals may be used. Furthermore, not only a single layer structure but also a multilayer structure may be employed. For example, a three-layer structure of MoNb layer / AlNd layer / MoNb layer may be employed. In this three-layer structure, the lower MoNb layer is preferably provided as an adhesion layer with the base, and the upper MoNb layer is preferably provided as a protective layer for the AlNd layer. The second electrode 3 can be laminated and formed by, for example, a vacuum deposition method, a sputtering method, a coating method, or the like. Although the thickness of the 2nd electrode 3 is not specifically limited, For example, it can be set as 100 nm-1000 nm.

  The organic layer 4 has, for example, a stacked structure of a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer.

  The hole injection layer is formed of, for example, a conductive polymer such as PEDOT / PSS or polyaniline; a conductive polymer doped with any acceptor; carbon nanotubes, CuPc (copper phthalocyanine), MTDATA [4,4 ′, 4 ″ − Examples include materials having both conductivity and light transmission properties such as Tris (3-methyl-phenylphenylamino) tri-phenylamine], TiOPC (titanyl phthalocyanine), amorphous carbon, etc. The hole injection layer is formed of a conductive polymer. In this case, for example, after the conductive polymer is processed into an ink form, the hole injection layer is formed by forming a film by a technique such as a coating method or a printing method. When formed from an inorganic material, the hole injection layer is formed by, for example, a vacuum deposition method.

  The hole transport layer is, for example, polyaniline, 4,4′-bis [N- (naphthyl) -N-phenyl-amino] biphenyl (α-NPD), N, N′-bis (3-methylphenyl)-(1 , 1′-biphenyl) -4,4′-diamine (TPD), 2-TNATA, 4,4 ′, 4 ″ -tris (N- (3-methylphenyl) N-phenylamino) triphenylamine (MTDATA) 4,4′-N, N′-dicarbazole biphenyl (CBP), spiro-NPD, spiro-TPD, spiro-TAD, TNB and the like, and triarylamine compounds, amine compounds containing carbazole groups , Amine compounds including fluorene derivatives, starburst amines (m-MTDATA), 1-TMATA, 2-TNATA, p- MTDATA, although such TFATA the like, is not limited to, any of the hole transporting materials commonly known can be used. Hole transport layer may be formed by a suitable method such as evaporation method.

The light emitting layer may be formed from an organic material (host material) doped with a light emitting organic substance (dopant). As the host material, any of an electron transporting material, a hole transporting material, and a material having both electron transporting property and hole transporting property can be used. As the host material, an electron transporting material and a hole transporting material may be used in combination. Examples of the host material include Alq ₃ (tris (8-oxoquinoline) aluminum (III)), TBADN (2-tert-butyl-9,10-di (2-naphthyl) anthracene), ADN, BDAF, CBP, Examples include, but are not limited to, CzTT, TCTA, mCP, CDBP. As the dopant material, a fluorescent light-emitting dopant or a phosphorescent light-emitting dopant can be used as appropriate. Since the phosphorescent dopant emits light from the triplet state, it has a luminous efficiency approximately four times higher than that of the fluorescent dopant that emits light only from the singlet state, and ideally has an internal quantum efficiency of 100%. High efficiency light emission becomes possible. Examples of the fluorescent light-emitting dopant include TBP (1-tert-butyl-perylene), BCzVBi, perylene, C545T (coumarin C545T; 10-2- (benzothiazolyl) -2,3,6,7-tetrahydro-1,1. , 7,7-tetramethyl-1H, 5H, 11H- (1) benzopyrrolopyrano (6,7, -8-ij) quinolidin-11-one)), DMQA, coumarin6, rubrene and the like. Is not to be done. Examples of the phosphorescent dopant include Ir (ppy) ₃ (factory (2-phenylpyridine) iridium), Ir (ppy) ₂ (acac), Ir (mppy) ₃ , Btp ₂ Ir (acac) (bis- (3- (2- (2-pyridyl) benzothienyl) mono-acetylacetonate) iridium (III))), Bt ₂ Ir (acac), PtOEP, and the like, but are not limited thereto. In order to obtain white light emission, these dopants may be appropriately combined.

  Examples of the electron transport layer include Alq3, oxadiazole derivatives, starburst oxadiazoles, triazole derivatives, phenylquinoxaline derivatives, silole derivatives, and the like. Specific examples of the electron transporting material include fluorene, bathophenanthroline, bathocuproine, anthraquinodimethane, diphenoquinone, oxazole, oxadiazole, triazole, imidazole, anthraquinodimethane, 4,4′-N, N′-dicarbazole. Biphenyl (CBP) and the like, compounds thereof, metal complex compounds, nitrogen-containing five-membered ring derivatives and the like can be mentioned. Specific examples of the metal complex compound include tris (8-hydroxyquinolinato) aluminum, tri (2-methyl-8-hydroxyquinolinato) aluminum, tris (8-hydroxyquinolinato) gallium, bis ( 10-hydroxybenzo [h] quinolinato) beryllium, bis (10-hydroxybenzo [h] quinolinato) zinc, bis (2-methyl-8-quinolinato) (o-cresolate) gallium, bis (2-methyl-8-quinolinato) ) (1-naphtholato) aluminum, bis (2-methyl-8-quinolinato) -4-phenylphenolate, and the like, but are not limited thereto. As the nitrogen-containing five-membered ring derivative, oxazole, thiazole, oxadiazole, thiadiazole, triazole derivatives and the like are preferable. Specifically, 2,5-bis (1-phenyl) -1,3,4-oxazole, 2 , 5-bis (1-phenyl) -1,3,4-thiazole, 2,5-bis (1-phenyl) -1,3,4-oxadiazole, 2- (4′-tert-butylphenyl) -5- (4 "-biphenyl) 1,3,4-oxadiazole, 2,5-bis (1-naphthyl) -1,3,4-oxadiazole, 1,4-bis [2- (5 -Phenylthiadiazolyl)] benzene, 2,5-bis (1-naphthyl) -1,3,4-triazole, 3- (4-biphenylyl) -4-phenyl-5- (4-t-butylphenyl) ) -1,2,4-Triazo Although Le etc., without limitation. The electron transport layer may be formed by a suitable method such as evaporation method.

Examples of the electron injection layer include alkali metals, alkali metal halides, alkali metal oxides, alkali metal carbonates, alkaline earth metals, alloys containing these metals, and the like. Sodium, sodium-potassium alloy, lithium, lithium fluoride, Li ₂ O, Li ₂ CO ₃ , magnesium, MgO, magnesium-indium mixture, aluminum-lithium alloy, Al / LiF mixture, and the like. The electron injection layer can also be formed from an organic material layer doped with an alkali metal such as lithium, sodium, cesium, or calcium, or an alkaline earth metal. The organic layer 4 can be laminated by, for example, a vacuum deposition method or a coating method. Although the thickness of the organic layer 4 is not specifically limited, For example, it can be set as 100 nm-300 nm.

The cathode layer 5 is an electrode (cathode) for injecting electrons into the organic layer 4. The cathode layer 5 is preferably formed from a material such as a metal, an alloy, an electrically conductive compound, or a mixture thereof having a low work function, and is preferably formed from a material having a work function of 5 eV or less. Examples of such a material include Al, Ag, MgAg, and the like. It can also be formed from an Al / Al ₂ O ₃ mixture or the like. When organic electroluminescence light is transmitted through the cathode layer 5, the cathode layer 5 is composed of a plurality of layers, and a part of the layer is formed of a transparent conductive material typified by ITO, IZO or the like. Is also preferable. The cathode layer 5 can be formed using these materials by an appropriate method such as a vacuum evaporation method or a sputtering method. When organic electroluminescence light is transmitted through the cathode layer 5, the light transmittance of the cathode layer 5 is preferably 10% or less. However, when organic electroluminescence light is transmitted through the cathode layer 5, the light transmittance of the cathode layer 5 is preferably 70% or more. The thickness of the cathode layer 5 is appropriately set so that characteristics such as light transmittance and sheet resistance of the cathode layer 5 are in a desired level. Although the preferable thickness of the cathode layer 5 changes with materials which comprise the cathode layer 5, the thickness of the cathode layer 5 is 500 nm or less, Preferably it is good to set in the range of 20-300 nm.

  As shown in FIGS. 2A and 2B, the first electrode 2 is formed in a rectangular shape in plan view, and is laminated on the surface (upper surface) of the substrate 1. In plan view, one side 2a of the four sides 2a, 2b, 2c, and 2d of the first electrode 2 is formed along the entire length of one side 1a of the four sides 1a, 1b, 1c, and 1d of the surface of the substrate 1. ing. Further, in plan view, two sides 2 b and 2 c orthogonal to the one side 2 a of the first electrode 2 are formed along two sides 1 b and 1 c orthogonal to the side 1 a of the substrate 1, respectively. The two sides 2 b and 2 c of the first electrode 2 are formed shorter than the two sides 1 b and 1 c of the substrate 1. Further, in plan view, the remaining one side 2d of the first electrode 2 and the remaining one side 1d of the substrate 1 are arranged substantially parallel to each other with substantially the same dimensions, and are arranged with a predetermined gap therebetween. In this way, the three sides 2a, 2b, 2c of the first electrode 2 are formed along the three sides 1a, 1b, 1c of the surface of the substrate 1, respectively.

  The second electrode 3 is formed in an elongated rectangular shape in plan view and is laminated on the surface (upper surface) of the substrate 1. In plan view, one side 3d of the four sides 3a, 3b, 3c, and 3d of the second electrode 3 extends along the entire length of one side 1d of the four sides 1a, 1b, 1c, and 1d of the substrate 1. Are formed. The side 1d of the substrate 1 is a remaining side that does not follow the first electrode 2, and is a side that is substantially parallel to the side 1a along the first electrode 2. In addition, the side 3 a on the other long side of the second electrode 3 is disposed to face the side 2 d of the first electrode 2 with a gap 6 in plan view. The side 3 a of the second electrode 3 is disposed substantially parallel to the side 2 d of the first electrode 2. Further, in a plan view, the two short-side sides 3b and 3c of the second electrode 3 are formed along two sides 1b and 1c of the four sides 1a, 1b, 1c and 1d of the substrate 1, respectively. ing. The two sides 3b and 3c on the short side of the second electrode 3 are formed in portions where the first electrode 2 of the two sides 1b and 1c of the substrate 1 is not along. In this way, one side 3d of the second electrode 3 is formed along the remaining side 1d that is not along the first electrode 2 on the surface of the substrate 1.

  The ratio of each of the first electrode 2, the second electrode 3, and the gap 6 on the surface of the substrate 1 is not particularly limited, but it is preferable to make the first electrode 2 as large as possible in order to increase the light emitting area. Of the total area of the surface of the substrate 1, the proportion of the first electrode 2 can be 90 to 96%, the proportion of the second electrode 3 can be 2 to 5%, and the remainder can be the gap 6.

  As shown in FIGS. 3A and 3B, the organic layer 4 is formed in a rectangular shape in plan view, and is electrically connected to the surface (upper surface) of the first electrode 2 and stacked. In plan view, one side 4a on the opposite side to the second electrode 3 side of the four sides 4a, 4b, 4c, and 4d of the organic layer 4 is one side 1a and the first electrode 2 on the opposite side to the second electrode 3 side of the substrate 1. It is formed substantially parallel to one side 2a opposite to the second electrode 3 side. In plan view, the sides 4 b and 4 c orthogonal to the side 4 a of the organic layer 4 are substantially the same as the sides 1 b and 1 c orthogonal to the side 1 a of the substrate 1 and the sides 2 b and 2 c of the first electrode 2, respectively. They are formed in parallel. Further, in plan view, one side 4 d of the organic layer 4 on the second electrode 3 side is formed substantially parallel to one side 1 d of the first electrode 2 on the second electrode 3 side. The end 7 on the side 4d side of the organic layer 4 enters the gap 6 and covers a part of the end face 8 on the gap 6 side of the first electrode 2. The organic layer 4 is formed smaller than the first electrode 2 in plan view. Therefore, the end portion of the surface (upper surface) of the first electrode 2 is not covered with the organic layer 4 and is exposed as the connection portion 9. The connecting portion 9 is formed in a U shape in plan view so as to extend along the sides 1a, 1b, and 1c.

  As shown in FIGS. 1A and 1B, the cathode layer 5 is formed in a rectangular shape in plan view, and is stacked over the surface (upper surface) of the organic layer 4 and the surface (upper surface) of the second electrode 3. The cathode layer 5 is electrically connected to the organic layer 4 and the second electrode 3. The area of the cathode layer 5 on the surface of the organic layer 4 is smaller than that of the surface of the organic layer 4. A part of the cathode layer 5 enters the gap 6 between the end 7 of the organic layer 4 and the second electrode 3. A portion corresponding to the cathode layer 5 on the surface of the organic layer 4 is formed as a light emitting area 10 (a portion surrounded by a thick dotted line in FIG. 1A). Then, by supplying power with the connecting portion 9 of the first electrode 2 as the anode terminal portion and the surface of the second electrode 3 as the cathode terminal portion, the organic layer 4 is energized and the portion corresponding to the light emitting area 10 emits light. Will do. This light emission is extracted from the organic EL element A through the first electrode 2 and the substrate 1.

  In the panel-shaped organic EL element A as described above, the connection portion 9 of the first electrode 2 that becomes a positive electrode and the second electrode 3 that becomes a negative electrode are formed along different sides of the substrate 1. As will be described later, when forming an organic electroluminescence unit (hereinafter, appropriately referred to as an organic EL unit) or a lighting fixture, when the plurality of organic EL elements A are juxtaposed, the connection between the organic EL elements A is easy. It can be done. Further, since the cathode film bonding area to the second electrode 3 can be made large, electromigration hardly occurs even when a high current is applied, and the conduction reliability is not easily lowered.

  In addition, in a panel-shaped organic EL element having a rectangular shape (including a square shape), power can be supplied from four sides. In this case, as the assignment of the first electrode 2 and the second electrode 3, a combination of the number of sides of the first electrode 2 / the number of sides of the second electrode 3 = 3/1 as in the organic EL element A can be considered. In addition, cases where the number of sides of the first electrode 2 / the number of sides of the second electrode 3 = 1/3 or 2/2 are also conceivable. Hereinafter, the effects of the invention will be shown by taking the first electrode 2 as ITO and the second electrode 3 as Al. However, the organic EL element A is not limited to these and is appropriately selected.

  First, the case where the number of sides of the first electrode 2 (ITO) / the number of sides of the second electrode 3 (Al) = 1/3 will be described. In general, the conductivity of ITO is lower than that of Al. In this case, since hole charges are supplied from only one side of the first electrode 2 into the light emitting area (light emitting surface) of the organic layer 4, it faces the one side of the first electrode 2 within the light emitting surface. A voltage drop occurs in the ITO surface before the hole charge reaches the side where the current is generated, and current unevenness tends to occur in the light emitting surface. As a result, unevenness in luminance and chromaticity within the light emitting surface occurs, and the light emission quality may be greatly impaired.

  Next, the case where the number of sides of the first electrode 2 (ITO) / the number of sides of the second electrode 3 (Al) = 2/2 will be described. As the assignment of the first electrode 2 and the second electrode 3 in this case, there can be considered a method in which two opposing sides are the same electrode and a method in which two adjacent sides are assigned to the same electrode.

  In the former case, two adjacent sides become ITO and Al, and local concentration is likely to occur as a current distribution, and as a result, the uniformity of luminance and chromaticity within the light emitting surface may be impaired. A case will be described in which a plurality of panel-shaped organic EL elements are juxtaposed and connected as if they were one large panel (referred to as an instrument) by connecting the organic EL elements. Power supply from four sides (ITO side 2 sides, Al side 2 sides) to the appliances in order to equalize the light emission brightness and emission chromaticity not only for each light emitting panel but also between the panels. Is necessary, and the cost may increase.

  In the latter case, as in the former case, not only local concentration of the current occurs in the portion where the two adjacent sides are in the relationship between ITO and Al, but also a voltage drop in the ITO in the light emitting surface occurs, and in the light emitting surface. Causes uneven current. As a result, unevenness in luminance and chromaticity within the light emitting surface occurs, and the light emission quality may be greatly impaired. In addition, when it is considered to join the power supply member to one side of each electrode 2, 3, in order to ensure a certain width, the first electrode 2, the organic layer 4, the second electrode 3, and the cathode layer 5 Four alignments need to be considered. Considering the inevitably occurring variation in the manufacturing process, it is necessary to provide a certain margin for the overlap between the layers, and as a result, there is a possibility that the effective light emitting area may be reduced.

  On the other hand, in the organic EL element A, the number of sides of the first electrode 2 (ITO) / the number of sides of the second electrode 3 (Al) = 3/1. Since the uniformity of the brightness and chromaticity within the surface of the panel-shaped organic EL element A is less likely to occur, high-quality light emission can be easily obtained. In addition, since the alignment of the organic layer 4, the second electrode 3, and the cathode layer 5 may be taken into consideration, it is possible to increase the effective light emitting area. In addition, the appliance form can be manufactured at low cost because it requires only two-sided feeding while ensuring uniformity between panels.

  4A to 4C show other embodiments of the organic EL element A. FIG. In this organic EL element A, the dimension between the one side 5a of the cathode layer 5 opposite to the second electrode 3 side and the one side 1a of the substrate 1 opposite to the second electrode 3 side is d1, the first electrode 2 The dimension between the side 2d on the second electrode 3 side and the side 1d on the second electrode 3 side of the substrate 1 is d3, the side 5b in the direction perpendicular to the side 5d on the second electrode 3 side of the cathode layer 5, When the dimension between 5c and one side 1b and 1c in the direction orthogonal to one side 1d on the second electrode 3 side of the substrate 1 is d2, it is formed so as to satisfy the relationship d1 + d3 = 2 × d2. . Other configurations are the same as those shown in FIG.

  In this embodiment, when a plurality of panel-shaped organic EL elements A are juxtaposed, the intervals between the organic EL elements A are substantially uniform, so that the appearance is good and the appearance is excellent. In addition, since the parts for joining the organic EL elements A can be shared, the workability is excellent and the cost increase can be suppressed. Further, since the plurality of organic EL elements A are arranged at substantially equal intervals, light can be irradiated with substantially no deviation.

  5A to 5C show other embodiments of the organic EL element A. FIG. In the organic EL element A, a third electrode 14 having a volume resistance lower than that of the first electrode 2 is provided on the surface (upper surface) of the connection portion 9 of the first electrode 2. Other configurations are the same as those shown in FIG. The third electrode 14 is preferably made of a metal such as aluminum, silver, gold, copper, chromium, molybdenum, aluminum, palladium, tin, lead, or magnesium, or an alloy containing at least one of these metals. Moreover, not only a single layer structure but a multilayer structure may be adopted. For example, a three-layer structure of MoNb layer / AlNd layer / MoNb layer can be employed. In this three-layer structure, the lower MoNb layer is preferably provided as an adhesion layer with the base, and the upper MoNb layer is preferably provided as a protective layer for the AlNd layer. Moreover, you may form with the material similar to the said 2nd electrode 3, such as aluminum. The third electrode 14 can be laminated and formed by, for example, a vacuum deposition method, a sputtering method, coating, or the like. Although the thickness of the 3rd electrode 14 is not specifically limited, For example, it can be set as 0.1-1 micrometer. After the first electrode 2 and the second electrode 3 are formed on the substrate 1 as shown in FIGS. 2 (a) and 2 (b), the third electrode 14 is connected to the connecting portion 9 as shown in FIGS. 6 (a) and 6 (b). It is provided over substantially the entire surface, and is formed in a substantially U shape in plan view.

  In this embodiment, by forming the third electrode 14 having a low resistance on the first electrode 2 having a high resistance, the voltage loss at the first electrode 2 can be suppressed and the light emitting area (light emitting surface) 10 can be suppressed. It is easy to make the light emission uniform.

  FIG. 7 shows another embodiment of the organic EL element A. In this organic EL element A, when the third electrode 14 is formed in the connection portion 9 as in the above embodiment, the extension portion 15 is provided at the end of the third electrode 14 on the second electrode 3 side. There are other configurations similar to those shown in FIG. As shown in FIG. 8A, the elongated portion 15 is formed on the surface (upper surface) of the first electrode 2 and is formed along one side 2 d facing the second electrode 3. Although the magnitude | size of the expansion | extension part 15 is not specifically limited, For example, length can be 2-5 mm and width can be 0.3-3 mm. Further, the extending portions 15 can be provided at both ends of the connecting portion 9. As shown in FIG. 8B, the surface (upper surface) of the elongated portion 15 is covered with the organic layer 4, but the upper portion of the elongated portion 15 is not covered with the cathode layer 5 as shown in FIG. Can be. As a result, it becomes difficult for the elongated portion 15 and the cathode layer 5 to be energized, and the light emission in the light emitting area (light emitting surface) 10 can be easily made uniform.

  As shown in FIGS. 9A and 9B, in the organic EL element A described above, the end face 16 (end face of the connecting portion 9) 16 of the first electrode 2 and the end face 17 of the substrate 1 are aligned in a vertical line. It is preferable that they are aligned. Moreover, it is preferable that the end face 18 of the second electrode 3 and the end face 17 of the substrate 1 are aligned and aligned in a straight line in the vertical direction. Further, when the third electrode 14 is provided, as shown in FIG. 10A, the end face 20 of the third electrode 14, the end face 16 of the first electrode 2, and the end face 17 of the substrate 1 are aligned in the vertical direction. It is preferable that they are aligned and aligned.

  In the organic EL element A, light emitted from the organic layer 4 is not only emitted from the surface via the substrate 1 but also propagates through the substrate 1, the first electrode 2, and the third electrode 14. Therefore, when the end faces 17, 16, and 20 of the substrate 1, the first electrode 2, and the third electrode 14 are aligned, light is also emitted from these end faces 17, 19, and 20, and the panel-like organic EL The joint between the elements A becomes less conspicuous, and the appearance of the organic electroluminescence unit U and the lighting fixture S described later is improved. As shown in FIG. 10B, if the end face 17 of the substrate 1 is shifted from the end face 16 of the first electrode 2 or the end face 20 of the third electrode 14, the joint may be noticeable.

  FIG. 11 shows an example of an embodiment of the organic electroluminescence unit U. The organic electroluminescence unit U can be formed in a panel shape by electrically connecting two or more organic EL elements A. In this case, first, the plurality of organic EL elements A are arranged in a line. At this time, the second electrode 3 side of the arranged organic EL elements A is set to face in the same direction. Therefore, the adjacent organic EL elements A and A are arranged such that the end portions 12 in the direction orthogonal to the end portion 11 on the second electrode 3 side approach or are joined to each other. Next, the connection portions 9 and 9 of the adjacent end portions 12 and 12 of the adjacent organic EL elements A and A are electrically connected. In this case, the conductive material 13 can be stretched between the connecting portions 9 and 9 to be connected. The conductive material 13 can be provided over substantially the entire length of the connecting portion 9 in the longitudinal direction. The conductive material 13 preferably has light reflectivity, and for example, a lead frame made of a Cu-based alloy can be used.

  In the above organic electroluminescence unit U, by connecting between adjacent panel-like organic EL elements A and A, the electrode width (width of the connecting portion 9) of the connection portion between the organic EL elements A and A is organic EL. As a result, the light emission within the light emitting area (light emitting surface) 10 is more uniform than the element A alone. Further, even when power is supplied to the plurality of organic EL elements A, it is only necessary to supply power to the two sides of the organic electroluminescence unit U, and power can be supplied efficiently.

  FIG. 12 shows an example of an embodiment of the lighting fixture S. This lighting fixture S can be formed in a panel shape by electrically connecting a plurality of organic EL light emitting units U arranged side by side. Adjacent organic EL units U and U include a second electrode 3 of one organic EL unit U and a connection portion 9 of the first electrode 2 on the opposite side to the second electrode 3 side of the other organic EL unit U. Are electrically connected. In this case, first, a plurality of organic EL units U are arranged. At this time, the second electrode 3 side of the arranged organic EL elements A is set to face in the same direction. Therefore, the adjacent organic EL units U, U are arranged such that the end 21 on the second electrode 3 side and the end 22 on the opposite side of the second electrode 3 are close to each other or joined together. Next, the 2nd electrode 3 of the edge parts 21 and 22 which adjoined or joined adjacent organic EL units U and U and the connection part 9 of the 1st electrode 2 are electrically connected. In this case, the same conductive material 13 as described above can be stretched between the second electrode 3 and the connection portion 9 to be connected. The conductive material 13 can be provided over substantially the entire length of the second electrode 3 and the connection portion 9 in the longitudinal direction.

  In the above-described lighting fixture S, the electrode width between the organic EL units U and U (the width of the second electrode 3 and the connection portion 9) is compared with that of the organic EL unit U alone by connecting the organic EL units U and U. As a result, the uniformity of light emission in the light emitting area (light emitting surface) 10 is improved. Further, even when power is supplied to the plurality of organic EL units U, it is only necessary to supply power to the two sides of the luminaire S, and power can be supplied efficiently.

FIG. 13 shows a connection structure of adjacent organic EL elements A and A in the organic EL unit U and the lighting fixture S. The conductive material 13 can be formed by a connecting piece 23 and a support piece 24 in a substantially T-shaped cross section. The support piece 24 is disposed between the adjacent connecting portions 9 and 9 of the adjacent organic EL elements A and A, and the lower end of the support piece 24 is placed on the end portion of the surface (upper surface) of the substrate 1. . The connecting piece 23 is disposed between the surfaces (upper surfaces) of the adjacent connecting portions 9 and 9. The lower surface of the connecting piece 23 and the upper surface of the connection portion 9 are bonded with a conductive paste 25 and are electrically connected. As the conductive paste 25, a low-temperature curing Ag paste or the like can be used. An optical adjustment layer 26 is provided between the side surface of the support piece 24 and the end surface of the connection portion 9. The optical adjustment layer 26 can be formed by filling a resin in which fine particles such as TiO ₂ and SiO ₂ are dispersed. When the third electrode 14 is provided, the lower surface of the connecting piece 23 and the upper surface of the third electrode 14 are connected by the conductive paste 25.

  The light emitted from the organic layer 4 is not only radiated from the surface via the substrate 1 but also has many components propagating through the substrate 1, the first electrode 2, and the third electrode 14, so that this component is electrically conductive. By scattering and reflecting with the material 13 or the optical adjustment layer 26, the light flux increases or the joint between the organic EL elements A becomes inconspicuous.

A organic electroluminescent element U organic electroluminescent unit S lighting fixture 1 substrate 1a side 1b side 1c side 1d side 2 first electrode 2a side 2b side 2c side 2d side 3 second electrode 4 organic layer 5 cathode layer 12 end 13 conductive Material 14 Third electrode 16 End face 17 End face 21 End 22 End

Claims (6)

A first electrode and a second electrode are formed on the surface of a rectangular substrate in plan view, an organic layer is formed on the surface of the first electrode, and a cathode extends across the surface of the organic layer and the surface of the second electrode. An organic electroluminescent device having a layer formed thereon,
The first electrode is formed so as to be electrically connectable to the first electrode or the second electrode of another organic electroluminescence element adjacent in the vertical direction or the horizontal direction,
The second electrode is formed so as to be aligned with the end surface of the substrate along one side of the surface of the substrate, and the first electrode is aligned with the end surface of the substrate along three sides other than the one side of the surface of the substrate. Formed,
A dimension between one side of the cathode layer opposite to the second electrode side and one side of the substrate opposite to the second electrode side is d1, and one side of the first electrode on the second electrode side is , A dimension between one side of the substrate on the second electrode side is d3, one side of the cathode layer in a direction orthogonal to the one side on the second electrode side, and one side of the substrate on the second electrode side is orthogonal to An organic electroluminescent element formed so as to satisfy a relationship of d1 + d3 = 2 × d2, where d2 is a dimension between one side in the direction in which the light is emitted. The organic electroluminescence device according to claim 1, wherein a third electrode having a volume resistance lower than that of the first electrode is provided on the first electrode . The organic electroluminescence device according to claim 2 , wherein the third electrode is formed up to one side of the first electrode facing the second electrode . 4. An organic electroluminescent unit in which two or more organic electroluminescent elements according to claim 1 are electrically connected, wherein the adjacent organic electroluminescent element is an end on the second electrode side. An organic electroluminescence unit, wherein the first electrodes are electrically connected to each other at an end portion in a direction orthogonal to the portion . 5. A lighting fixture in which two or more organic electroluminescent units according to claim 4 are electrically connected, wherein the adjacent organic electroluminescent unit includes a second electrode of one of the organic electroluminescent units and the other of the organic electroluminescent units. The lighting apparatus, wherein the first electrode on the opposite side to the second electrode side of the organic electroluminescence unit is electrically connected . A member that electrically connects the second electrode of one of the organic electroluminescent units and the first electrode on the side opposite to the second electrode of the other organic electroluminescent unit has light reflectivity. The lighting fixture according to claim 5 .

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