JP6340911B2 - Organic electroluminescent device and method for producing organic electroluminescent device - Google Patents

Description

  The present invention relates to an organic electroluminescent device and a method for manufacturing the organic electroluminescent device, and more particularly to an organic electroluminescent device having a patterned light emitting region and a method for manufacturing the same.

An organic electroluminescence element (so-called organic EL element) using electroluminescence (hereinafter referred to as EL) of an organic material has a structure in which a light emitting functional layer composed of an organic material is sandwiched between two electrodes. The emitted light generated in the light emitting functional layer passes through the electrode and is extracted outside. For this reason, at least one of the two electrodes is configured as a transparent electrode. The transparent electrode is generally configured using an oxide semiconductor material such as indium tin oxide (SnO ₂ -In ₂ O ₃ : Indium Tin Oxide: ITO).

  The organic electroluminescence device as described above has a light emitting region patterned in various forms. For example, a configuration in which a light emitting functional layer is damaged by partial irradiation of energy rays to form a non-irradiation region is known. It has been. As a method for producing an organic electroluminescent element having such a configuration, for example, a method of forming a light emitting functional layer on a glass substrate with ITO, forming a counter electrode on top of this, and irradiating ultraviolet rays from the glass substrate side is available. It has been proposed (see Patent Document 1 below). Further, a method has been proposed in which an organic material band is formed on a transparent substrate via a first electrode, a second electrode is formed, a protective film is formed, and then ultraviolet rays or electron beams are irradiated (the following patents) Reference 2).

Japanese Patent No. 2793373 JP 2005-183045 A

  However, among the manufacturing methods described above, the method using an electron beam as an energy beam for patterning requires that the atmosphere irradiated with the electron beam be in a vacuum state, which increases the manufacturing cost.

  On the other hand, a method using ultraviolet rays as an energy beam for patterning can be processed in the atmosphere. However, ultraviolet rays are highly absorbed by metals. Therefore, when a metal transparent electrode is used as the transparent electrode on the light extraction side, the absorption of ultraviolet rays in the metal transparent electrode is large, and the patterning described above is performed by ultraviolet irradiation from the transparent substrate side on which the metal transparent electrode is formed. In order to carry out, the irradiation time of ultraviolet rays becomes long. As a result, not only the production efficiency is lowered, but also the transparent substrate made of a resin material is discolored so that the color purity of the extracted light is lowered, or the ultraviolet irradiation pattern is visually recognized when the light is not emitted. Occur.

  Accordingly, an object of the present invention is to provide an organic electroluminescent element in which a light emitting region is efficiently formed without changing the color of a transparent substrate in a configuration using a metal transparent electrode on the light extraction side, and a method for manufacturing the same. To do.

  An organic electroluminescent element of the present invention for achieving such an object has a transparent substrate, a metal transparent electrode provided on one main surface side of the transparent substrate, and a plurality of layers including a light emitting layer, A light emitting functional layer provided on one main surface side of the transparent substrate via the metal transparent electrode, and a counter electrode provided on one main surface side of the transparent substrate via the light emitting functional layer, Any one layer constituting the light emitting functional layer is an ultraviolet absorbing layer satisfying (k / n) × Z ≧ 5 when the absorption coefficient k, the refractive index n, and the film thickness Z are set, and the alteration due to ultraviolet irradiation And a non-light emitting region is patterned corresponding to the altered portion.

  The method for producing an organic electroluminescent element of the present invention is the above-described method for producing an organic electroluminescent element, and in the step of forming the light emitting functional layer, any one of the light emitting functional layers is made to have an absorption coefficient k. In the step of forming an ultraviolet absorbing layer satisfying (k / n) × Z ≧ 5 when the refractive index is n and the film thickness is Z, and the non-light-emitting region is patterned, the metal transparent An altered portion is formed in the ultraviolet absorbing layer by irradiating ultraviolet rays through the electrode.

  In the organic electroluminescence device having such a configuration, since any one of the layers constituting the light emitting functional layer is an ultraviolet absorbing layer, the altered portion formed in the ultraviolet absorbing layer is concentrated in the light emitting functional layer. It is formed by absorption. For this reason, even if it is a case where an ultraviolet-ray is irradiated through a metal transparent electrode with high absorption of an ultraviolet-ray, efficient formation of an altered part is performed.

  As described above, according to the organic electroluminescent element and the method for manufacturing the same of the present invention, even if the ultraviolet ray is irradiated through the metal transparent electrode having high ultraviolet absorption, the altered portion is efficiently formed. Therefore, it is possible to efficiently pattern the light emitting region without changing the color of the transparent substrate in the organic electroluminescent element using the metal transparent electrode.

It is a cross-sectional schematic diagram which shows the structure of the organic electroluminescent element of embodiment. It is a schematic plan view which shows the structure of the organic electroluminescent element of embodiment. It is sectional process drawing (the 1) which shows the manufacturing method of the organic electroluminescent element of embodiment. It is sectional process drawing (the 2) which shows the manufacturing method of the organic electroluminescent element of embodiment.

  Hereinafter, embodiments of the present invention will be described in detail in the order of an organic electroluminescent element and a method for producing an organic electroluminescent element based on the drawings.

≪Organic electroluminescent element≫
FIG. 1 is a schematic cross-sectional view showing the configuration of the organic electroluminescent element 1 of the embodiment. FIG. 2 is a schematic plan view showing the configuration of the organic electroluminescent element 1 of the embodiment, and is a view of FIG. 1 viewed from the light extraction surface 10a side.

  The organic electroluminescent element 1 shown in these drawings is provided on one main surface of a transparent substrate 11, and a metal transparent electrode 13, a light emitting functional layer 15, and a counter electrode 17 are laminated in order from the transparent substrate 11 side. ing. The light emitting functional layer 15 includes a plurality of layers including at least the light emitting layer 15c. In such an organic electroluminescent element 1, a portion where the light emitting functional layer 15 is sandwiched between the metal transparent electrode 13 and the counter electrode 17 is an element region a in the organic electroluminescent element 1, and is patterned in the element region a. A light emitting area A is provided.

  In particular, in the organic electroluminescent element 1 of the present embodiment, one of the light emitting functional layers 15 is configured as the ultraviolet absorbing layer 21. The ultraviolet absorbing layer 21 has an altered portion b due to irradiation of ultraviolet rays, and a region corresponding to the altered portion b in the organic electroluminescent element 1 is patterned as a non-emitting region B.

  The organic electroluminescent element 1 as described above is configured as a bottom emission type in which the emitted light h is extracted with at least the other main surface of the transparent substrate 11 as the light extraction surface 10a. Although not shown here, the organic electroluminescent element 1 is sealed with a sealing material from the counter electrode 17 side, and the light emitting functional layer 15 and the sealing material are sandwiched between the transparent substrate 11. A protective member may be provided.

  Hereinafter, the detail of each component which comprises this organic electroluminescent element 1 is demonstrated.

<Transparent substrate 11>
Examples of the transparent substrate 11 include glass, quartz, and resin substrates, but are not limited thereto. A particularly preferable transparent substrate 11 is a resin substrate capable of giving flexibility to an organic electroluminescent element formed using the same.

  The resin substrate may be composed of (1) a resin base material as a support and one or more (2) barrier layers having a refractive index in the range of 1.4 to 1.7. preferable. Hereinafter, details of (1) the resin base material and (2) the barrier layer will be described.

(1) Resin substrate As the resin substrate, a conventionally known resin film substrate can be used without particular limitation. The resin base material preferably used in the present invention preferably has gas barrier properties such as moisture resistance and gas permeation resistance required for the organic electroluminescent element 1. In addition, a material having translucency with respect to visible light is used for the resin base material. In this case, the light transmittance is preferably 70% or more, more preferably 75% or more, and further preferably 80% or more.

  The resin base material preferably has flexibility. The term “flexibility” as used herein refers to a base material that is wound around a φ (diameter) 50 mm roll and does not crack before and after winding with a constant tension, and more preferably a base that can be wound around a φ30 mm roll. Say the material.

  In the present invention, the resin base material is a conventionally known base material, for example, an acrylic resin such as acrylic ester, methacrylic ester, polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene naphthalate. Phthalate (PEN), polycarbonate (PC), polyarylate, polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PP), polystyrene (PS), nylon (Ny), aromatic polyamide, polyether ether ketone, polysulfone , Polyether sulfonate, polyimide, polyetherimide, polyolefin, epoxy resin, and other resin films, and cycloolefin-based and cellulose ester-based films can also be used. In addition, a heat-resistant transparent film (product name Sila-DEC, manufactured by Chisso Corporation) having silsesquioxane having an organic-inorganic hybrid structure as a basic skeleton, and a resin film formed by laminating two or more layers of the resin material, etc. Can be mentioned.

  From the viewpoint of cost and availability, PET, PEN, PC, acrylic resin and the like are preferably used.

  Among these, a biaxially stretched polyethylene terephthalate film and a biaxially stretched polyethylene naphthalate film are preferable from the viewpoints of transparency, heat resistance, ease of handling, strength, and cost.

  Furthermore, in order to suppress the shrinkage at the time of thermal expansion to the maximum, a low heat recovery processed product subjected to a treatment such as thermal annealing is most preferable.

  10-500 micrometers is preferable, as for the thickness of a resin base material, More preferably, it is 20-250 micrometers, More preferably, it is 30-150 micrometers. When the thickness of the resin base material is in the range of 10 to 500 μm, a stable gas barrier property can be obtained, and it is suitable for conveyance in a roll-to-roll system.

(2) Barrier layer <2.1> Properties and formation method As the barrier layer, a known material can be used without any particular limitation, and a coating made of an inorganic or organic material or a hybrid coating combining these coatings may be used. . The barrier layer has a water vapor permeability (25 ± 0.5 ° C., relative humidity 90 ± 2% RH) measured by a method according to JIS-K-7129-1992, 0.01 g / (m ² · 24 hours. ) The following barrier films are preferable, and the oxygen permeability measured by a method according to JIS-K-7126-1987 is 1 × 10 ⁻³ ml / (m ² · 24 hours · atm) or less. More preferably, the film has a water barrier permeability of 1 × 10 ⁻⁵ g / (m ² · 24 hours) or less.

  As a material for forming such a barrier layer, any material may be used as long as it 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. Furthermore, in order to improve the weakness of the barrier layer, an organic layer made of an organic material may be laminated on these inorganic layers as a stress relaxation layer. Although there is no restriction | limiting in particular about the lamination order of an inorganic layer and an organic layer, The structure which laminates | stacks both alternately several times is preferable.

  The method for forming the barrier layer 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, or the like can be used, but an atmospheric pressure plasma polymerization method described in JP-A-2004-68143 is particularly preferable.

<2.2> Formation Method Using Inorganic Precursor Compound Further, as a barrier layer, a coating liquid containing at least one layer of an inorganic precursor compound is applied on a resin substrate to form a coating film, and then the coating is performed. A method may be used in which an inorganic layer is formed by subjecting the film to a modification treatment with an excimer lamp or the like.

  As a coating method, a conventionally known wet coating method can be applied. For example, a roller coating method, a flow coating method, an ink jet method, a spray coating method, a printing method, a dip coating method, a casting film forming method, a bar coating method. Method, gravure printing method and the like.

  The thickness of the coating film can be appropriately set according to the purpose. For example, the thickness of the coating film is preferably in the range of 0.001 to 10 μm, more preferably in the range of 0.01 to 10 μm, and most preferably 0.03 to 1 μm after drying. It is preferable to set so as to be within the range of.

  The inorganic precursor compound used in the present invention is not particularly limited as long as it is a compound capable of forming a metal oxide, a metal nitride, or a metal oxynitride by irradiation with vacuum ultraviolet rays (excimer light) under a specific atmosphere. In the present invention, as a compound suitable for forming the barrier layer, a compound that can be modified at a relatively low temperature as described in JP-A-8-112879 is preferable.

  Specifically, polysiloxane (including polysilsesquioxane) having Si—O—Si bond, polysilazane having Si—N—Si bond, both Si—O—Si bond and Si—N—Si bond And polysiloxazan containing These can be used in combination of two or more. Moreover, it can be used even if different compounds are sequentially laminated or simultaneously laminated.

<Metal transparent electrode 13>
The metal transparent electrode 13 is provided as an anode or a cathode for the light emitting functional layer 15. The term “transparent” in the metal transparent electrode 13 means that the light transmittance at a wavelength of 550 nm is 50% or more. The main component in the metal transparent electrode 13 means that the content in the metal transparent electrode 13 is 98% by mass or more.

  The metal contained in the metal transparent electrode 13 is not particularly limited as long as it is a highly conductive metal, and examples thereof include silver, copper, gold, platinum group, titanium, and chromium. The metal transparent electrode 13 may contain only one kind of these metals or two or more kinds. From the viewpoint of high conductivity, the metal transparent electrode 13 is preferably composed of silver as a main component and is composed of silver or an alloy having silver as a main component.

  Examples of the alloy mainly composed of silver (Ag) constituting the metal transparent electrode 13 include silver magnesium (AgMg), silver copper (AgCu), silver palladium (AgPd), silver palladium copper (AgPdCu), silver indium ( AgIn) and the like.

  The metal transparent electrode 13 as described above may have a configuration in which silver or an alloy layer mainly composed of silver is divided into a plurality of layers as necessary.

  Further, the metal transparent electrode 13 preferably has a thickness in the range of 5 to 20 nm. When the film thickness is less than 20 nm, the absorption component or reflection component of the layer is small, and the transmittance of the metal transparent electrode 13 is increased. Moreover, when the film thickness is thicker than 5 nm, the conductivity of the layer can be sufficiently ensured.

  As a method for forming the metal transparent electrode 13 as described above, a method using a wet process such as a coating method, an ink jet method, a coating method, a dip method, a vapor deposition method (resistance heating, EB method, etc.), a sputtering method, a CVD method, or the like. And a method using a dry process such as a method. Among these, the vapor deposition method is preferably applied.

  In addition, the metal transparent electrode 13 is characterized in that it is sufficiently conductive even when there is no high-temperature annealing treatment after the metal transparent electrode 13 is formed by forming a film on the underlayer. In addition, high temperature annealing treatment or the like after film formation may be performed.

  The metal transparent electrode 13 thus provided as an ultrathin film is provided with an auxiliary electrode at a position that does not hinder the extraction of the emitted light h from the transparent substrate 11 for the purpose of reducing the resistance. It may be connected. The material for forming such an auxiliary electrode is preferably a metal having low resistance such as gold, platinum, silver, copper, or aluminum.

  Further, the metal transparent electrode 13 may be provided with an extraction electrode for connection to an external power source. The material of the extraction electrode is not particularly limited, and a known electrode material can be suitably used. For example, a metal film such as a MAM electrode (Mo / Al · Nd alloy / Mo) having a three-layer structure is used. Can do.

  Moreover, it is preferable that the metal transparent electrode 13 is provided on the transparent substrate 11 through the base layer which abbreviate | omitted illustration here. In this case, for example, a layer formed using a compound containing nitrogen atoms is used as the underlayer.

  The foundation layer is a layer provided on the transparent substrate 11 side of the metal transparent electrode 13. The material constituting the underlayer is not particularly limited as long as it can suppress the aggregation of silver when forming the metal transparent electrode 13 made of, for example, silver or an alloy containing silver as a main component. Examples thereof include nitrogen-containing compounds containing nitrogen atoms.

  When the underlayer is made of a low refractive index material (refractive index less than 1.7), the upper limit of the film thickness needs to be less than 50 nm, preferably less than 30 nm, and preferably less than 10 nm. More preferably, it is particularly preferably less than 5 nm. By making the film thickness less than 50 nm, optical loss can be minimized. On the other hand, the lower limit of the film thickness is required to be 0.05 nm or more, preferably 0.1 nm or more, and particularly preferably 0.3 nm or more. By setting the film thickness to 0.05 nm or more, the underlayer can be uniformly formed, and the effect (inhibition of silver aggregation) can be made uniform.

  When the underlayer is made of a high refractive index material (refractive index of 1.7 or more), the upper limit of the film thickness is not particularly limited, and the lower limit of the film thickness is the same as that of the low refractive index material. .

  However, if the base layer is used as a simple base layer, it is sufficient that the base layer is formed with a required film thickness that allows uniform film formation.

  The compound containing a nitrogen atom constituting the underlayer is not particularly limited as long as it is a compound containing a nitrogen atom in the molecule, but is preferably a compound having a heterocycle having a nitrogen atom as a heteroatom. Examples of the heterocycle having a nitrogen atom as a hetero atom include aziridine, azirine, azetidine, azeto, azolidine, azole, azinane, pyridine, azepan, azepine, imidazole, pyrazole, oxazole, thiazole, imidazoline, pyrazine, morpholine, thiazine, indole, Examples include isoindole, benzimidazole, purine, quinoline, isoquinoline, quinoxaline, cinnoline, pteridine, acridine, carbazole, benzo-C-cinnoline, porphyrin, chlorin, choline and the like.

  As a method for forming the underlayer, a method using a wet process such as a coating method, an ink jet method, a dip method, a method using a dry process such as a vapor deposition method (resistance heating, EB method, etc.), a sputtering method, a CVD method, etc. Is mentioned. Among these, the vapor deposition method is preferably applied.

<Light emitting functional layer 15>
The light emitting functional layer 15 is a layer including a light emitting layer made of at least an organic material. Thus, the overall layer structure of the light emitting functional layer 15 is not limited and may be a general layer structure. An example of the light emitting functional layer 15 is shown below, but the present invention is not limited thereto.

(I) Hole injection transport layer / light emitting layer / electron injection transport layer (ii) Hole injection transport layer / first light emitting layer / second light emitting layer / electron injection transport layer (iii) Hole injection transport layer / first Light emitting layer / intermediate layer / second light emitting layer / electron injecting and transporting layer (iv) Hole injecting and transporting layer / light emitting layer / hole blocking layer / electron injecting and transporting layer (v) Hole injecting and transporting layer / electron blocking layer / light emission Layer / hole blocking layer / electron injection transport layer (vi) hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer (vii) hole injection layer / hole transport layer / light emitting layer / Hole blocking layer / electron transport layer / electron injection layer (viii) Hole injection layer / hole transport layer / electron blocking layer / light emitting layer / hole blocking layer / electron transport layer / electron injection layer

  In the configurations of (ii) and (iii) above, the first light emitting layer and the second light emitting layer may be each color light emitting layer that generates emitted light in each wavelength region. In the configuration (iii), the intermediate layer disposed between the first light emitting layer and the second light emitting layer may be non-light emitting, and may function as a hole blocking layer and an electron blocking layer. good.

  In FIG. 1, the light-emitting functional layer 15 is formed of [hole injection layer 15 a / hole transport layer 15 b / light-emitting layer 15 c / electron transport layer 15 d / in order from the electrode side used as the anode among the metal transparent electrode 13 and the counter electrode 17. The electron injection layer 15e] is illustrated as a stacked structure. Details of each layer will be described below.

(1) Light emitting layer 15c
The light emitting layer 15c used in the present invention preferably contains a phosphorescent light emitting compound as a light emitting material. Note that a fluorescent material may be used as the light emitting material, or a phosphorescent light emitting compound and a fluorescent material may be used in combination.

  The light emitting layer 15c is a layer that emits light by recombination of electrons injected from the cathode side and holes injected from the anode side. Even if the light emitting portion is within the layer of the light emitting layer 15c, the light emitting layer. It may be an interface between 15c and an adjacent layer.

  Such a light emitting layer 15c is not particularly limited in its configuration as long as the contained light emitting material satisfies the light emission requirements. There may be a plurality of layers having the same emission spectrum and emission maximum wavelength. In this case, it is preferable to have a non-light emitting intermediate layer (not shown) between the light emitting layers 15c.

  The total thickness of the light emitting layer 15c is preferably in the range of 1 to 100 nm, and more preferably in the range of 1 to 40 nm because a lower driving voltage can be obtained.

  In addition, the sum total of the film thickness of the light emitting layer 15c is a film thickness also including the said intermediate | middle layer, when a nonluminous intermediate | middle layer exists between the light emitting layers 15c. However, in the case of a so-called tandem type device in which a plurality of light emitting layer units are stacked via an intermediate connector portion, the light emitting layer 15c here refers to a light emitting layer portion in each light emitting unit.

  In the case of the light emitting layer 15c having a configuration in which a plurality of layers are stacked, the thickness of each light emitting layer is preferably adjusted within a range of 1 to 50 nm, and more preferably adjusted within a range of 1 to 20 nm. preferable. When the plurality of stacked light emitting layers correspond to blue, green, and red light emitting colors, there is no particular limitation on the relationship between the film thicknesses of the blue, green, and red light emitting layers.

  The light emitting layer 15c as described above is formed by forming a known light emitting material or host compound by a known thin film forming method such as a vacuum deposition method, a spin coating method, a casting method, an LB method, or an ink jet method. be able to.

  The light emitting layer 15c may be a mixture of a plurality of light emitting materials.

  As a structure of the light emitting layer 15c, it is preferable to contain a host compound (also referred to as a light emitting host) and a light emitting material (also referred to as a light emitting dopant), and to emit light from the light emitting material.

  Examples of the light-emitting dopant applicable to the present invention include International Publication No. WO 2005/076380, International Publication No. 2010/032663, International Publication No. 2008/140115, International Publication No. 2007/052431, International Publication No. 2011. No. 134013, International Publication No. 2011/157339, International Publication No. 2010/086089, International Publication No. 2009/113646, International Publication No. 2012/020327, International Publication No. 2011/051404, International Publication No. 2011/004639. No., WO 2011/073149, JP 2012-069737, JP 2009-114086, JP 2003-81988, JP 2002-302671, JP 2002-363552, etc. Compounds described in It can be mentioned.

  Examples of the host compound include JP-A Nos. 2001-257076, 2002-308855, 2001-313179, 2002-319491, 2001-357777, and 2002-334786. Gazette, 2002-8860, 2002-334787, 2002-15871, 2002-334788, 2002-43056, 2002-334789, 2002-75645 2002-338579, 2002-105445, 2002-343568, 2002-141173, 2002-352957, 2002-203683, 2002-363227 2002-231453, 2003-3165, 2002-234888, 2003-27048, 2002-255934, 2002-260861, 2002-280183, 2002-299060, 2002-302516, 2002-305083, 2002-305084, 2002-308837, US 2003/0175553, US 2006 No. 0280965, U.S. Patent Publication No. 2005/0112407, U.S. Patent Publication No. 2009/0017330, U.S. Patent Publication No. 2009/0030202, U.S. Patent Publication No. 2005/238919, International Publication No. 2001/039234, International Publication No. 2009/021126, International Publication No. 2008/056746, International Publication No. 2004/093207, International Publication No. 2005/089025, International Publication No. 2007/063796, International Publication No. 2007/063754, International Publication No. 2004/107822, International Publication No. 2005/030900, International Publication No. 2006/114966, International Publication No. 2009/086028, International Publication No. 2009/003898, International Publication No. 2012 No. 023947, JP 2008-074939 A, JP 2007-254297 A, EP 2034538, and the like.

(2) Hole injection layer 15a and electron injection layer 15e
The injection layer is a layer provided between the electrode and the light emitting layer 15c in order to lower the driving voltage and improve the light emission luminance. “The organic EL element and its forefront of industrialization (November 30, 1998, NT. The details are described in Chapter 2, “Electrode Materials” (pages 123 to 166) of the second edition of “S. Co., Ltd.”, and there are a hole injection layer 15a and an electron injection layer 15e.

  An injection | pouring layer is a structure layer which can be provided as needed. The hole injection layer 15a may be present between the anode and the light emitting layer 15c or the hole transport layer 15b, and the electron injection layer 15e may be present between the cathode and the light emitting layer 15c or the electron transport layer 15d.

  The details of the hole injection layer 15e are described in JP-A-9-45479, JP-A-9-260062, JP-A-8-288069, and the like. Specific examples thereof include phthalocyanine represented by copper phthalocyanine. Examples thereof include a layer, an oxide layer typified by vanadium oxide, an amorphous carbon layer, and a polymer layer using a conductive polymer such as polyaniline (emeraldine) or polythiophene. Moreover, it is also preferable to use the material described in Japanese translations of PCT publication No. 2003-519432 gazette.

  Details of the electron injection layer 15e are described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like, and specifically, strontium, aluminum, and the like are representative. Examples thereof include a metal layer, an alkali metal halide layer typified by potassium fluoride, an alkaline earth metal compound layer typified by magnesium fluoride, and an oxide layer typified by molybdenum oxide. In the present invention, the electron injection layer 15e is desirably a very thin film, and the film thickness is preferably in the range of 1 nm to 10 μm although it depends on the material.

(3) Hole transport layer 15b
The hole transport layer 15b is made of a hole transport material having a function of transporting holes, and in a broad sense, the hole injection layer 15a and the electron blocking layer are also included in the hole transport layer 15b. The hole transport layer 15b can be provided as a single layer or a plurality of layers.

  The hole transport material has any of the characteristics 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.

  As the hole transport material, those described above can be used, and it is further 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, for example, N, N, N ′, N′-tetraphenyl-4,4′-diaminophenyl; N, N′-diphenyl-N, N '-Bis (3-methylphenyl)-[1,1'-biphenyl] -4,4'-diamine (abbreviation: 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-tolylaminophenyl) -4-phenylcyclohexane; bis (4-dimethylamino-2-methylphenyl) phenylmethane; bis (4-di-p-tolylaminophenyl) phenylmethane; N, N'-dipheni -N, N'-di (4-methoxyphenyl) -4,4'-diaminobiphenyl; N, N, N ', N'-tetraphenyl-4,4'-diaminodiphenyl ether; 4,4'-bis ( N, N, N-tri (p-tolyl) amine; 4- (di-p-tolylamino) -4 ′-[4- (di-p-tolylamino) styryl] stilbene; N, N-diphenylamino- (2-diphenylvinyl) benzene; 3-methoxy-4′-N, N-diphenylaminostilbenzene; N-phenylcarbazole, and further in US Pat. No. 5,061,569 Those having two fused aromatic rings described in the molecule, for example, 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (abbreviation: NPD) 4,4 ′, 4 ″ -tris [N- (3-methylphenyl) -N-phenylamino, wherein three triphenylamine units described in JP-A-4-308688 are linked in a starburst type ] Triphenylamine (abbreviation: 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. , Applied Physics Letters, 80 (2002), p. A so-called p-type hole transport material as described in 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 15b is 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 inkjet method, or an LB method. be able to. Although there is no restriction | limiting in particular about the film thickness of the positive hole transport layer 15b, Usually, 5 nm-about 5 micrometers, Preferably it is 5-200 nm. The hole transport layer 15b may have a single layer structure composed of one or more of the above materials.

  In addition, the transport property can be increased by doping impurities into the material of the hole transport layer 15b. Examples thereof include JP-A-4-297076, JP-A-2000-196140, 2001-102175, J.A. Appl. Phys. 95, 5773 (2004), and the like.

(4) Electron transport layer 15d
The electron transport layer 15d is made of a material having a function of transporting electrons. In a broad sense, the electron injection layer 15e and a hole blocking layer (not shown) are also included in the electron transport layer 15d. The electron transport layer 15d can be provided as a single layer structure or a stacked structure of a plurality of layers.

  In the electron transport layer 15d having a single layer structure and the electron transport layer 15d having a multilayer structure, an electron transport material (also serving as a hole blocking material) constituting a layer portion adjacent to the light emitting layer 15c was injected from the cathode. What is necessary is just to have the function to transmit an electron to the light emitting layer 15c. As such a material, any one of conventionally known compounds can be selected and used. Examples include nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimides, fluorenylidenemethane derivatives, anthraquinodimethane, anthrone derivatives, and oxadiazole derivatives. Further, 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 are also used as the material for the electron transport layer 15d. Can do. 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 (abbreviation: Alq3), 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 (abbreviation: Znq), and the central metals of these metal complexes A metal complex replaced with In, Mg, Cu, Ca, Sn, Ga, or Pb can also be used as the material of the electron transport layer 15d.

  In addition, metal-free or metal phthalocyanine, or those having terminal ends substituted with alkyl groups or sulfonic acid groups can be preferably used as the material for the electron transport layer 15d. Further, a distyrylpyrazine derivative exemplified also as a material of the light emitting layer 15c can be used as a material of the electron transport layer 15d. Similarly to the hole injection layer 15a and the hole transport layer 15b, n-type -Si, n An inorganic semiconductor such as type-SiC can also be used as the material of the electron transport layer 15d.

  The electron transport layer 15d can be formed by thinning the above material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an inkjet method, or an LB method. Although there is no restriction | limiting in particular about the film thickness of 15 d of electron carrying layers, Usually, 5 nm-about 5 micrometers, Preferably it is 5-200 nm. The electron transport layer 15d may have a single layer structure composed of one or more of the above materials.

  In addition, the electron transport layer 15d can be doped with an impurity to increase transportability. 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. Further, the electron transport layer 15d preferably contains potassium, a potassium compound, or the like. As the potassium compound, for example, potassium fluoride can be used. Thus, when the n property of the electron transport layer 15d is increased, an element with lower power consumption can be manufactured.

  Further, as the material (electron transporting compound) of the electron transport layer 15d, the same material as that constituting the above-described underlayer may be used. The same applies to the electron transport layer 15d that also serves as the electron injection layer 15e, and the same material as that for the above-described underlayer may be used.

(5) Blocking layer Examples of the blocking layer include a hole blocking layer and an electron blocking layer, and the light emitting functional layer 15 may be further provided in addition to the above functional layers. 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.

  In a broad sense, the hole blocking layer has the function of the electron transport layer 15d. The hole blocking layer is made of a hole blocking material that has a function of transporting electrons but has a very small ability to transport holes, and recombines electrons and holes by blocking holes while transporting electrons. Probability can be improved. Further, the configuration of the electron transport layer 15d can be used as a hole blocking layer as required. The hole blocking layer is preferably provided adjacent to the light emitting layer 15c.

  On the other hand, the electron blocking layer has the function of the hole transport layer 15b in a broad sense. The electron blocking layer is made of a material that has a function of transporting holes but has a very small ability to transport electrons, and improves the probability of recombination of electrons and holes by blocking electrons while transporting holes. be able to. Moreover, the structure of the said hole transport layer 15b can be used as an electron blocking layer as needed. In the present invention, the thickness of the hole blocking layer is preferably in the range of 3 to 100 nm, more preferably in the range of 5 to 30 nm.

<Ultraviolet absorbing layer 21>
The ultraviolet absorbing layer 21 is composed of any one of the layers constituting the light emitting functional layer 15. Here, the ultraviolet absorption layer 21 is a layer satisfying (k / n) × Z ≧ 5 when the absorption coefficient k, the refractive index n, and the film thickness Z are set. This value is a value that serves as an index of the degree of absorption of light having a wavelength λ with respect to a layer having a film thickness Z as follows.

  That is, the transmittance of light having a wavelength λ with respect to a layer having a film thickness Z is I1 when the incident light intensity is I0, the transmitted light intensity I1, the angular frequency ω of light, the absorption coefficient k, the refractive index n, and the light velocity c. / I0 = exp (−2ωk / c · Z) = exp (−4πk / λ / n · Z). Therefore, the larger the value of k / n · Z, the lower the transmittance of light (ultraviolet light) of wavelength λ in the layer with the film thickness Z (ultraviolet absorbing layer 21), and the absorptance increases.

  The ultraviolet absorbing layer 21 as described above is any one layer constituting the light emitting functional layer 15 and may be any layer as long as it can independently satisfy (k / n) × Z ≧ 5. Since such an ultraviolet absorbing layer 21 is a layer formed using a material having a high absorption coefficient k among the layers constituting the light emitting functional layer 15, it is not necessary to set the film thickness Z to a large value. It is preferable from the viewpoint of ensuring the thinning of the element and the light emission characteristics, and for example, the hole transport layer 15b is applied.

  Many of the compounds exemplified above as the hole transport material constituting the hole transport layer 15b have a larger absorption coefficient k than the compounds constituting the other layers. It is possible to constitute the ultraviolet absorption layer 21 with one layer.

<Denatured part b>
The altered portion b is a region provided in the ultraviolet absorbing layer 21 and is a region in which a part of the ultraviolet absorbing layer 21 has been altered by irradiation with ultraviolet rays. The altered portion b is provided corresponding to a region obtained by inverting the light emitting region A in the organic electroluminescent element 1.

  In the organic electroluminescent element 1, a non-light emitting region B is formed in a pattern corresponding to the altered portion b of the ultraviolet absorbing layer 21. This non-light emitting region B is a region obtained by inverting the light emitting region A.

<Counter electrode 17>
The counter electrode 17 is provided in a state in which the light emitting functional layer 15 is sandwiched between the metal transparent electrode 13, and is used as a cathode when the metal transparent electrode 13 is an anode, and when the metal transparent electrode 13 is a cathode. Is used as an anode. The counter electrode 17 is configured by using a conductive material appropriately selected in consideration of a work function among metals, alloys, organic or inorganic conductive compounds, and mixtures thereof. Specifically, gold, aluminum, silver, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, indium, lithium / aluminum mixture, rare earth metal, indium doped tin oxide ( ITO), ZnO, TiO ₂ , SnO _{2 and} other oxide semiconductors.

  If the organic electroluminescent element 1 is configured to extract the emitted light h only from the transparent substrate 11 side, a material having good reflection characteristics of the emitted light h is selected from the conductive materials described above, and the counter electrode is selected. 17 is preferably configured. On the other hand, if the organic electroluminescent element 1 is a double-sided light emitting type that also takes out the emitted light h from the counter electrode 17 side, a conductive material having good light transmission property is selected from the above-described conductive materials. What is necessary is just to comprise the electrode 17. FIG.

  The counter electrode 17 as described above is formed by depositing a selected conductive material by vapor deposition or sputtering.

<Encapsulant>
The sealing material not shown here covers the organic electroluminescent element 1 from the counter electrode 17 side, and may or may not have optical transparency. However, in the case where the organic electroluminescent element 1 extracts the emitted light h from the counter electrode 17 side, a transparent sealing material having light transmittance is used as the sealing material. Such a sealing material may be a plate-like (film-like) sealing member that is fixed to the transparent substrate 11 side by an adhesive, or may be a sealing film.

  The sealing material as described above is provided in a state in which the terminal portions of the metal transparent electrode 13 and the counter electrode 17 in the organic electroluminescent element 1 are exposed and at least the light emitting functional layer 15 is covered. Further, an electrode may be provided on the sealing material, and the terminal portions of the metal transparent electrode 13 and the counter electrode 17 of the organic electroluminescent element 1 may be electrically connected to this electrode.

  Examples of the material constituting the plate-like (film-like) sealing material include a glass plate, a polymer plate / film, and a metal plate / film. 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 particular, since the element can be thinned, a thin film-like polymer substrate or metal substrate can be preferably used as the sealing material.

Further, the polymer substrate in the form of a film has an oxygen permeability measured by a method according to JIS K 7126-1987 of 1 × 10 −3 ml / (m ² · 24 h · atm) or less, and conforms to JIS K 7129-1992. The water vapor permeability (25 ± 0.5 ° C., relative humidity (90 ± 2)% RH) measured by a compliant method is 1 × 10 ⁻³ g / (m ² · 24 h) or less. preferable.

  Further, the above substrate material may be processed into a concave plate shape and used as a sealing material. In this case, the substrate member described above is subjected to processing such as sandblasting and chemical etching to form a concave shape.

  Further, as an adhesive for fixing the plate-shaped sealing material to the transparent substrate 11 side, a sealing agent for sealing the organic electroluminescent element 1 sandwiched between the sealing material and the transparent substrate 11 is used. Used as Specifically, such adhesives include acrylic acid oligomers, photocuring and thermosetting adhesives having reactive vinyl groups of methacrylic acid oligomers, and moisture curable adhesives such as 2-cyanoacrylates. Mention may be made of adhesives.

  Moreover, as such an adhesive agent, the 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, the organic material which comprises the organic electroluminescent element 1 may deteriorate with heat processing. For this reason, an adhesive that can be adhesively cured from room temperature to 80 ° C. is preferable. A desiccant may be dispersed in the adhesive.

  Application | coating of the adhesive agent to the adhesion part of a sealing material and the transparent substrate 11 may use a commercially available dispenser, and may print like screen printing.

  In addition, when a gap is formed between the plate-shaped sealing material, the transparent substrate 11 and the adhesive, this gap may be an inert gas such as nitrogen or argon or fluorinated carbonization in the gas phase and the liquid phase. It is preferable to inject an inert liquid such as hydrogen or silicon oil. 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.

  On the other hand, when the sealing film is used as the sealing material, the light emitting functional layer 15 in the organic electroluminescent element 1 is completely covered and the terminal portions of the metal transparent electrode 13 and the counter electrode 17 in the organic electroluminescent element 1 are exposed. Thus, a sealing film is provided on the transparent substrate 11.

  Such a sealing film is configured using an inorganic material or an organic material. In particular, it is made of a material having a function of suppressing intrusion of a substance that causes deterioration of the light emitting functional layer 15 in the organic electroluminescent element 1 such as moisture or oxygen. As such a material, for example, inorganic materials such as silicon oxide, silicon dioxide, and silicon nitride are used. Further, in order to improve the brittleness of the sealing film, a laminated structure may be formed using a film made of an organic material in addition to a film made of these inorganic materials.

  The method for forming these films is not particularly limited. For example, 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 A polymerization method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used.

<Others>
In addition to the above, the organic electroluminescent element 1 may be provided with a protective member with a sealing material interposed between the transparent substrate 11 and the organic electroluminescent element 1. This protective member is for mechanically protecting the organic electroluminescent element 1, and in particular, when the sealing material is a sealing film, mechanical protection for the organic electroluminescent element 1 is not sufficient. Therefore, it is preferable to provide such a protective member.

  A glass plate, a polymer plate, a thinner polymer film, a metal plate, a thinner metal film, a polymer material film or a metal material film is applied to the protective member as described above. Among these, it is particularly preferable to use a polymer film because it is light and thin.

  Moreover, the organic electroluminescent element 1 may be provided with a light extraction layer for efficiently extracting the emitted light h generated in the light emitting functional layer 15 in a necessary portion as necessary.

≪Method for manufacturing organic electroluminescent element≫
3 and 4 are cross-sectional process diagrams for explaining the method of manufacturing the organic electroluminescent element described above. Hereinafter, based on these drawings, the organic electroluminescence device 1 shown in FIG. 1 is taken as an example, and the method for producing the organic electroluminescence device of the present invention will be described.

<Lamination process>
First, as shown in FIG. 3, the metal transparent electrode 13, the light emitting functional layer 15, and the counter electrode 17 are formed in this order on the transparent substrate 11. However, before the formation of the metal transparent electrode 13, a base layer (not shown) may be formed as a pretreatment.

  In the formation of the underlayer, for example, the underlayer made of a nitrogen-containing compound containing nitrogen atoms is formed by a thin film forming method such as a vapor deposition method so as to have a layer thickness of 1 μm or less, preferably 10 to 100 nm. To do.

  Thereafter, the metal transparent electrode 13 made of silver or an alloy containing silver as a main component is formed on the underlayer by a thin film forming method such as a vapor deposition method, preferably within a thickness range of 5 to 20 nm. At this time, the metal transparent electrode 13 is formed in a shape in which the terminal portion is drawn on the periphery of the transparent substrate 11 by performing film formation using, for example, a mask as necessary.

  Next, the hole injection layer 15a, the hole transport layer 15b, the light emitting layer 15c, the electron transport layer 15d, and the electron injection layer 15e are laminated on the metal transparent electrode 13 in this order to form the light emitting functional layer 15. Form. At this time, the material and film thickness of each layer are set so that any one layer constituting the light emitting functional layer 15 becomes the ultraviolet absorbing layer 21.

  For example, in the illustrated example, the film thickness of the hole transport layer 15b is set so that (k / n) × Z ≧ 5 in consideration of the absorption coefficient k and the refractive index n of the hole transport material constituting the hole transport layer 15b. Z is set, and this hole transport layer 15 b is formed as the ultraviolet absorption layer 21. On the other hand, the thicknesses of the layers other than the hole transport layer 15b are set so that (k / n) × Z <5 in consideration of the absorption coefficient k and the refractive index n.

When a vapor deposition method is applied to the formation of each layer constituting these light emitting functional layers 15, the vapor deposition conditions vary depending on the type of compound used, etc., but the boat heating temperature is generally in the range of 50 to 450 ° C., the degree of vacuum In the range of 1 × 10 ⁻⁶ to 1 × 10 ⁻² Pa, the deposition rate in the range of 0.01 to 50 nm / second, the resin substrate temperature in the range of −50 to 300 ° C., and the layer thickness of 0. It is preferable that each condition is appropriately selected within the range of 1 to 5 μm. At this time, the layers constituting the light emitting functional layer 15 are formed in a shape exposing the terminal portion of the metal transparent electrode 13 by performing film formation using, for example, a mask as necessary.

  After the light emitting functional layer 15 is formed as described above, the counter electrode 17 is formed on the light emitting functional layer 15 by an appropriate thin film forming method such as vapor deposition or sputtering. In this case, for example, by forming a film using a mask as necessary, a shape in which a terminal portion is drawn to the periphery of the transparent substrate 11 while maintaining an insulating state between the light emitting functional layer 15 and the metal transparent electrode 13. A counter electrode 17 is formed on the substrate.

  Thus, the element region a in which the light emitting functional layer 15 is sandwiched between the metal transparent electrode 13 and the counter electrode 17 is formed, and the element structure 10 in which the terminals of the metal transparent electrode 13 and the counter electrode 17 are drawn from the element region a is formed. To do.

  In addition, formation of the base layer and the metal transparent electrode 13 to the counter electrode 17 described above may be performed by patterning each formed layer into a predetermined shape after forming each layer. Further, before and after the formation of the metal transparent electrode 13, the auxiliary electrode pattern may be formed as necessary.

  In addition, the above-described lamination process is preferably a procedure in which the underlayer and the metal transparent electrode 13 to the counter electrode 17 are consistently formed by a single evacuation. May be applied. At that time, it is necessary to consider that the work is performed in a dry inert gas atmosphere.

<Sealing process>
After the lamination step, sealing from the counter electrode 17 side is performed. Here, a sealing material is provided so as to cover the laminate of the metal transparent electrode 13 to the counter electrode 17 between the transparent substrate 11 and the terminal portions of the metal transparent electrode 13 and the counter electrode 17 exposed.

<Pattern formation process>
As shown in FIG. 4, the pattern formation process by ultraviolet irradiation is performed between the laminating process and the sealing process described above or after the sealing process. Here, the ultraviolet absorbing layer 21 provided in the light emitting functional layer 15 is partially altered by the irradiation of the ultraviolet ray UV from the transparent substrate 11 side of the element structure 10, and the altered portion b is formed in the ultraviolet absorbing layer 21, A region corresponding to the altered portion b is defined as a non-light emitting region B.

  The pattern forming step may be performed before the sealing step as long as it is after the laminating step. However, by performing the pattern forming step after the sealing step, ultraviolet irradiation in the atmosphere becomes possible. Therefore, it is preferable from the viewpoint of simplifying the process and reducing the manufacturing cost.

  In this pattern formation step, a light emitting region A is set in the element region a, and ultraviolet light UV is selectively irradiated to a region obtained by inverting the light emitting region A. At this time, as shown in the figure, ultraviolet rays UV are collectively irradiated through the light shielding mask 23 covering the light emitting region A, or spot-shaped ultraviolet rays UV are drawn and irradiated so as to fill the irradiation region.

  As the irradiation conditions of the ultraviolet rays UV, the irradiated portion of the ultraviolet absorbing layer 21 in the ultraviolet absorbing layer 21 becomes a deteriorated portion b that has been sufficiently altered, and the portion corresponding to the altered portion b in the element region a becomes the non-light emitting region B. It is assumed that the irradiation is performed with a dose sufficient for the portion to become the light emitting region A. As a specific example, the non-light-emitting region B is irradiated with an irradiation amount at which the luminance of the non-light-emitting region B is about 1/100 of the luminance of the light-emitting region A. Further, such irradiation with ultraviolet rays UV is performed within a range where the transparent substrate 11 is not discolored by the irradiation with ultraviolet rays UV.

  The ultraviolet irradiation conditions as described above are adjusted by the light amount and wavelength of the ultraviolet rays in consideration of the absorption rate of the ultraviolet rays UV in the ultraviolet absorbing layer 21.

  The ultraviolet ray UV irradiated in the pattern forming step refers to an electromagnetic wave having a wavelength longer than that of X-rays and shorter than the shortest wavelength of visible light. Specifically, the wavelength region is in the range of 1 to 400 nm. In the pattern forming step, visible light or infrared light may be included in addition to ultraviolet UV.

  There are no particular limitations on the means for generating and irradiating ultraviolet light UV as long as it is a method capable of generating light using a conventionally known irradiation apparatus or the like and irradiating a predetermined region.

  As a light source applicable to the present invention, a high pressure mercury lamp, a low pressure mercury lamp, a hydrogen (deuterium) lamp, a rare gas (xenon, argon, helium, neon, etc.) discharge lamp, a nitrogen laser, an excimer laser (XeCl, XeF, KrF, KrCl, etc.), hydrogen laser, halogen laser and the like.

  Through the pattern forming process as described above, as shown in FIGS. 1 and 2, the organic electroluminescent element 1 in which a desired light emitting region A is patterned can be manufactured.

  In driving the organic electroluminescent element 1 obtained in this way, the anode side (here, the metal transparent electrode 13) of the metal transparent electrode 13 and the counter electrode 17 has a positive polarity, and the cathode side (here, the counter electrode 17). When the electrode 17) is set to a negative polarity and a voltage of about 2 to 40 V is applied, light emission can be observed. Moreover, you may apply an alternating voltage. The alternating current waveform to be applied may be arbitrary.

  The bottom emission type organic electroluminescent elements of Sample 101 to Sample 110 were produced. First, a stacking process to a sealing process in manufacturing Samples 101 to 110 will be described. In Table 1 below, as physical properties of each layer constituting the light emitting functional layer, an absorption coefficient k, a refractive index n, a film thickness Z, a value calculated from this (k / n) × Z, and a transmittance T (% )showed that.

<Preparation of Sample 101>
(Preparation of resin base material)
A biaxially stretched polyethylene terephthalate film (PET film, thickness: 125 μm, width: 350 mm, Tg: 110 ° C.) was prepared as a resin substrate.

(Formation of barrier layer)
A transparent layer in which a barrier layer is formed on one main surface of the resin substrate in the same manner as the barrier film sample 1 described in Example 1 of JP2012-599A, and the barrier layer is provided on the resin substrate. A substrate was produced.

(Formation of underlayer)
The transparent substrate was transferred into a vacuum deposition apparatus, and the following nitrogen-containing compound N-1 was deposited on the barrier layer with a thickness of 25 nm to form a base layer.

(Formation of metal transparent electrode)
Subsequently, silver was vapor-deposited with the thickness of 10 nm through the mask, and the metal transparent electrode was formed. This metal transparent electrode was formed as the anode of the organic electroluminescent element.

(Formation of light emitting functional layer)
Next, in each of the vapor deposition crucibles equipped in the vacuum vapor deposition apparatus, the following compound L-1 as a hole injection material, the following compound M-1 as a hole transport material, and the following as a host compound of a green light emitting layer: Compound H-1 as the dopant for the green light emitting layer, the following compound GD-1, the following compound E-1 as the electron transporting material, lithium fluoride (LiF) as the electron injecting material, and the optimum amounts for forming each layer Filled. As the evaporation crucible, one made of a resistance heating material made of molybdenum or tungsten was used.

Subsequently, after reducing the pressure in the vacuum deposition apparatus to 4 × 10 ⁻⁴ Pa, the deposition crucible containing the compound L-1 was energized and heated to deposit the compound L-1 at a deposition rate of 0.1 nm / second. On a transparent metal electrode. Thus, a hole injection layer having an absorption coefficient k = 0.22, a refractive index n = 2.28, and a film thickness Z = 10 nm was provided.

  Subsequently, the said crucible for vapor deposition containing the compound M-1 was electrically supplied and heated, and the compound M-1 was vapor-deposited on the positive hole injection layer with the vapor deposition rate of 0.1 nm / sec. Thus, a hole transport layer having an absorption coefficient k = 0.40, a refractive index n = 2.00, and a film thickness Z = 10 nm was provided.

  Next, Compound GD-1 and Compound H-1 were co-deposited at a deposition rate of 0.1 nm / second so that Compound GD-1 had a concentration of 5%. Thus, a light emitting layer exhibiting green light emission having an absorption coefficient k = 0.125, a refractive index n = 1.79, and a film thickness Z = 30 nm was formed.

  Next, Compound E-1 was deposited on the light emitting layer at a deposition rate of 0.1 nm / second. Thus, an electron transport layer having an absorption coefficient k = 0.036, a refractive index n = 2.03, and a film thickness Z = 30 nm was formed.

  Further, the deposition crucible containing LiF was energized and heated to deposit LiF on the electron transport layer at a deposition rate of 0.05 nm / second. Thus, an electron injection layer having an absorption coefficient k = 0.00, a refractive index n = 1.40, and a film thickness Z = 1 nm was provided.

  As described above, a light emitting functional layer composed only of each layer of (k / n) × Z <5 was formed.

(Formation of counter electrode)
Thereafter, aluminum was deposited on the electron injection layer to form a counter electrode having a layer thickness of 110 nm as a cathode.

(Sealing process)
The surface of the transparent substrate up to the counter electrode was covered with an epoxy resin having a thickness of 300 μm to form a sealing material, and further covered with an aluminum foil having a thickness of 12 μm to form a protective film, and then the epoxy resin was cured. All the operations so far were 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 transparent substrate into contact with the air atmosphere. Thus, an element structure was formed.

<Preparation of Sample 102 to Sample 107>
In the formation of the element structure of the sample 101 described above, the hole transport material was changed to the following compound M-2. As a result, as shown in Table 1 below, the hole transport layers having the absorption coefficient k = 0.49, the refractive index n = 1.88, and the film thickness Z = 20 nm to 330 nm are converted into samples 102 to 107, respectively. Formed in each of the. Each of the formed hole transport layers becomes an ultraviolet absorption layer having physical properties (k / n) × Z ≧ 5. Except for this, Sample 102 to Sample 107 were prepared in the same procedure as Sample 101.

<Preparation of Sample 108>
In the preparation of the sample 101 described above, the hole injection layer serving as an ultraviolet absorption layer having a physical property value (k / n) × Z ≧ 5 was formed by changing the film thickness of the hole injection layer to Z = 55 nm. Except for this, the sample 108 was manufactured in the same procedure as the sample 101.

<Preparation of Sample 109>
In the preparation of the sample 101 described above, the light emitting layer serving as the ultraviolet absorption layer having the physical property value (k / n) × Z ≧ 5 was formed by changing the film thickness of the light emitting layer to Z = 75 nm. Except for this, the sample 109 was manufactured in the same procedure as the sample 101.

<Preparation of Sample 110>
In the preparation of the sample 101 described above, the electron transport material was changed to the following compound E-2. As a result, as shown in Table 1 below, an electron transport layer having an absorption coefficient k = 0.089, a refractive index n = 1.65, and a film thickness Z = 95 nm was formed. The formed electron transport layer is an ultraviolet absorption layer having physical properties (k / n) × Z ≧ 5. Except for this, the sample 110 was manufactured in the same procedure as the sample 101.

  In Table 1, the ultraviolet transmittance of each layer is also shown.

<Pattern formation process for sample 101 to sample 110>
With respect to each of the element structures of the samples 101 to 110 manufactured as described above, the surface opposite to the surface provided with the light emitting functional layer and the like in the transparent substrate, that is, the light extraction surface 10a side shown in FIG. Then, a mask using an ultraviolet absorption filter (manufactured by Isuzu Seiko Glass Co., Ltd.) was placed and adhered under reduced pressure. This ultraviolet absorption filter has a light transmittance of 50% or less for a wavelength component of 320 nm or less. Further, the mask using the ultraviolet absorption filter is provided with an opening corresponding to the light emitting region, and the ultraviolet ray UV is irradiated from the opening to the light extraction surface 10a.

Next, using a UV tester (Iwasaki Electric Co., Ltd., SUV-W151: 100 mW / cm ² ), ultraviolet light is irradiated from the light extraction surface 10 a side of the transparent substrate 11, and the ultraviolet irradiation part is set as a non-light emitting region B. Each organic electroluminescent element which formed a pattern by making other than that into the light emission area | region A was produced.

<(1) Evaluation of luminance ratio>
Each organic electroluminescent element that has been irradiated with ultraviolet rays UV for 5 hours in the pattern forming process as described above is driven at a constant current with a current at which the luminance of the light-emitting region A that is not irradiated with ultraviolet rays is 500 cd / cm ^2. The luminance of the irradiated part (non-light emitting area B) was measured. The measurement result of the luminance of the non-light emitting region B was calculated as a relative value with the luminance of the light emitting region A as 100, and is shown in Table 2 below.

<(2) Evaluation of irradiation time>
Following the above-described evaluation of the luminance ratio, the irradiation with the ultraviolet ray UV was further continued, and the irradiation time until the luminance of the non-light emitting region B became 1/100 of the luminance of the light emitting region A was examined.

<(3) Evaluation of chromaticity difference>
About each organic electroluminescent element which evaluated the irradiation time mentioned above, the chromaticity of the light emission area | region A and the non-light emission area | region B at the time of non-light emission was measured. An automatic colorimeter (Konica Minolta, CM-2600D) was used to measure each chromaticity. The measured results are shown in Table 2 below as chromaticity difference (Δb).

<(4) Evaluation of drive voltage>
About each organic electroluminescent element which evaluated irradiation time mentioned above, the drive voltage from which the brightness | luminance of the light emission area | region A was set to 1000 cd / cm < ² > was measured in -20 degreeC environment. The measurement results are shown in Table 2 below.

  In addition, the measurement of the brightness | luminance in the above evaluation was measured using the spectral radiance meter CS-2000 (made by Konica Minolta).

<Evaluation results>
As shown in Table 2 above, the organic electroluminescent elements of Samples 102 to 110, that is, any one of the layers constituting the light emitting functional layer is an ultraviolet absorbing layer having a physical property value (k / n) × Z ≧ 5. Compared with the organic electroluminescent element of the sample 101, the organic electroluminescent element having the configuration has (1) a small luminance ratio and (2) a short irradiation time. It was confirmed that the light-emitting area A and the non-light-emitting area B can be patterned. It was also confirmed that (3) the chromaticity difference (Δb) was small, and the discoloration due to the deterioration of the transparent substrate (resin base material) due to ultraviolet irradiation could be suppressed to a small level.

  In addition, as the value of physical property value (k / n) × Z was larger, (1) the luminance ratio was smaller, (2) the irradiation time was shorter, and (3) the chromaticity difference (Δb) tended to be smaller. It was confirmed that the larger the physical property value (k / n) × Z, the more efficiently the light emitting area A and the non-light emitting area B can be patterned. Further, when looking at the drive voltage (4), the organic electroluminescent elements of the present invention configuration of Samples 102 to 110 can be driven at a drive voltage of 5 V or less even in a low temperature environment where the drive voltage generally increases. confirmed. If the physical property value (k / n) × Z ≦ 85, the drive voltage can be suppressed to less than 4 V, and thus it can be said that the physical property value is preferably 5 ≦ (k / n) × Z ≦ 85.

  Further, as can be seen from the evaluation results of the samples 102 to 107, the physical property value (k / n) can be obtained by adjusting the film thickness Z by using a hole transport layer made of a material having a large absorption coefficient k as an ultraviolet absorption layer. ) × Z can be arbitrarily set within a wide range.

  DESCRIPTION OF SYMBOLS 1 ... Organic electroluminescent element, 11 ... Transparent substrate, 13 ... Metal transparent electrode, 15 ... Light emission functional layer, 15a ... Hole injection layer, 15b ... Hole transport layer (ultraviolet absorption layer), 15c ... Light emitting layer, 15d ... Electron transport layer, 15e ... Electron injection layer, 17 ... Counter electrode (light reflective electrode), 21 ... UV absorbing layer, 23 ... Mask, A ... Light emitting region, B ... Non-light emitting region, b ... Altered portion, uv ... Ultraviolet light

Claims (8)

A transparent substrate;
A metal transparent electrode provided on one main surface side of the transparent substrate;
A plurality of layers including a light emitting layer, and a light emitting functional layer provided on one main surface side of the transparent substrate via the metal transparent electrode;
A counter electrode provided on one main surface side of the transparent substrate through the light emitting functional layer,
The light emitting functional layer is an ultraviolet absorbing layer only one of a plurality of layers including the light emitting layer,
The ultraviolet absorbing layer, the absorption coefficient k, the refractive index n, and when the film thickness was set to Z [nm] a layer serving as a (k / n) × Z ≧ 5, irradiation only the ultraviolet absorbing layer of ultraviolet It has an altered part due to
An organic electroluminescence device in which a non-light emitting region is patterned corresponding to the altered portion. The organic electroluminescent element according to claim 1, wherein the metal transparent electrode contains silver as a main component. The organic electroluminescent element according to claim 1, wherein the counter electrode is a light reflective electrode. The organic electroluminescent element according to claim 1, wherein the transparent substrate is made of a resin material. The organic electroluminescent element according to claim 1, wherein the ultraviolet absorbing layer is a hole transport layer. The organic electroluminescence device according to claim 1, wherein (k / n) × Z ≦ 85. Laminating a metal transparent electrode, a light emitting functional layer having a plurality of layers including a light emitting layer, and a counter electrode in this order on a transparent substrate;
A step of patterning a non-light-emitting region in which the light-emitting functional layer is partially altered by irradiation with ultraviolet rays,
In the step of forming the light emitting functional layer, when only one layer constituting the light emitting functional layer has an absorption coefficient k, a refractive index n, and a film thickness Z [nm] , (k / n) × Z ≧ Formed as an ultraviolet absorbing layer to be 5,
In the step of patterning the non-light-emitting region, a method for producing an organic electroluminescence device, wherein an altered portion is formed only in the ultraviolet absorbing layer by irradiating ultraviolet rays from the transparent substrate side through the metal transparent electrode. The method of manufacturing an organic electroluminescent element according to claim 7, wherein the irradiation with ultraviolet light is performed through a mask that opens the non-light-emitting region.

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