WO2014069831A1 - Organic light emitting diode and manufacturing method therefor - Google Patents

Abstract

The present invention relates to an organic light emitting diode and a manufacturing method therefor, and the organic light emitting diode comprises: a lower electrode formed on a light-transmitting substrate; an organic thin film layer which is formed on the lower electrode and includes a light-emitting layer; a light-transmitting upper electrode formed on the organic thin film layer; a functional layer which is formed on the upper electrode and enables mutual reinforcement and interference for the transmitted lights; and a reflective layer formed on the functional layer.

Description

Organic electroluminescent device and manufacturing method thereof

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electroluminescent device, and more particularly, to an organic electroluminescent device having high chromaticity and high luminance characteristics by improving the efficiency of light emitted from the organic light emitting layer by using light reinforcement and interference.

Organic light emitting diodes are self-luminous devices that have a wide viewing angle, excellent contrast, fast response time, excellent luminance, driving voltage and response speed, and multi-coloring. .

A general organic EL device includes an organic light emitting layer for emitting light and a first electrode and a second electrode which face each other with the organic light emitting layer interposed therebetween.

The organic electroluminescent device is divided into a bottom emission type and a top emission type according to a direction in which light generated from the organic emission layer is emitted. The bottom emission type emits light toward the formed substrate, and a reflective electrode is formed on the organic emission layer. A transparent electrode is formed below the organic emission layer. Here, when the organic electroluminescent device adopts an active matrix method, the portion where the thin film transistor is formed may not transmit light, thereby reducing the area where light can be emitted. In contrast, in the front emission type, since a transparent electrode is formed on the organic light emitting layer and a reflective electrode is formed on the organic light emitting layer, light is emitted in a direction opposite to the substrate side, thereby increasing the area through which light is transmitted, thereby improving luminance. have.

The organic light emitting device of the bottom emission method may have a structure in which a positive electrode (anode) is formed on an upper surface of the substrate, and a hole transport layer, an emission layer, an electron transport layer, and a negative electrode (cathode) are sequentially formed on the anode. Here, the hole transport layer, the light emitting layer and the electron transport layer are organic thin films made of an organic compound.

Since the cathode is made of a metal layer having a property of a reflective layer, light emitted from the light emitting layer may be reflected to the anode layer to increase luminous efficiency.

The driving principle of the organic EL device having the structure as described above is as follows. When a voltage is applied between the anode and the cathode, holes injected from the anode move to the light emitting layer via the hole transport layer, and electrons injected from the cathode move to the light emitting layer via the electron transport layer. Carriers such as holes and electrons recombine in the emission layer to generate excitons. The excitons change from excited state to ground state and light is generated.

At this time, the generated light goes straight in the positive electrode direction and the negative electrode direction and various directions, and the light that goes straight toward the positive electrode passes through the glass and exits the air layer, and the light that goes straight to the negative electrode is reflected by the metal layer, which is the negative electrode, to be directed back to the positive electrode.

As a related art, in Patent Publication No. 10-2006-0095489, a light emitting layer is provided between a first electrode and a second electrode, and a reflective layer for reflecting light emitted from the light emitting layer and exiting from the second electrode side is provided with a first A technique related to an organic electroluminescent element provided on the electrode side is disclosed, and in Japanese Patent Laid-Open No. 2001/0101640, a translucent electrode and a reflective electrode are made using interference generated by multiple reflection of light between the transmissive electrode and the reflective electrode. The technique which raises luminous efficiency by setting the film thickness in between so that a target wavelength may resonate is described.

1 illustrates an organic electroluminescent device manufactured by the prior art. This will be described in detail with respect to the prior art.

In order to manufacture the organic EL device, first, the transparent conductive film 20 (ITO) is coated on the soda-lime or alkali-free glass substrate 10, and then the photoresist (PR) is applied to the surface by using a spin coater, and then UV The exposure is performed to produce the desired pattern shape. After that, the device is loaded into a vacuum evaporator to deposit a hole injection layer 30 (HIL), a hole transport layer 40 (HTL), a light emitting layer 50 (EML), an electron transport layer 60 (ETL), and a negative electrode 70 (metal electrode). .

Subsequently, when the electric current is applied to the transparent electrode and the metal electrode by applying a DC power source or a voltage of several tens of volts, the organic EL device emits light, and the light irradiated toward the negative electrode is reflected through the reflector to reflect the glass substrate. Is investigated.

At this time, the reflected light may show interference effect with light that is irradiated from the light emitting layer and directed toward the positive electrode, but the existing organic EL device structure has a problem that a high color coordinate cannot be obtained due to the low constructive interference effect due to the limitation of the structure. In order to obtain high color coordinates of the organic electroluminescent device, a material having a low color coordinate may be used, or an appropriate color coordinate may be obtained by adjusting the thickness of the device, but it has a problem of reducing driving voltage, efficiency, and lifetime.

The present invention is to solve the above-described problems, to improve the efficiency of the light emitted from the organic light emitting layer and to provide an organic electroluminescent device having a high color.

The present invention is a lower electrode formed on a light-transmissive substrate; An organic thin film layer formed on the lower electrode and including a light emitting layer; A transparent upper electrode formed on the organic thin film layer; A functional layer formed on the upper electrode and mutually reinforcing and interfering transmitted light; And an reflective layer formed on the functional layer.

In one embodiment, the organic electroluminescent device may be provided with an auxiliary electrode on the edge of the lower electrode.

In one embodiment, the lower electrode is a conductive transparent electrode, it may have a thickness of 1 nm to 1000 nm.

In one embodiment, the upper electrode has a transmittance of 10% or more and a resistance value may range from 0.1 mΩ to 500 Ω.

In one embodiment, the upper electrode has a thickness in the range of 1 nm to 1000 nm, the upper electrode material is copper, chromium, molybdenum, nickel, aluminum, magnesium, silver, gold, platinum, indium tin oxide (ITO) , Indium zinc oxide (IZO), zinc oxide (ZnO), ZnO / Ga ₂ O ₃ , ZnO / Al ₂ O ₃ , sodium, sodium-potassium alloy, cesium, lithium, magnesium-silver alloy, aluminum oxide, aluminum-lithium The electrode materials composed of alloys, indium, rare earth metals, mixtures of these metals and organic luminescent media materials, and mixtures of these metals and electron injection layer materials may be used alone or in combination of two or more thereof. have.

In one embodiment, the functional layer may have a refractive index of 0.1 to 10 and a thickness of 1 nm to 1000 nm.

In one embodiment, the functional layer is an inorganic material of a metal oxide or metal nitride; It may be any one or combination thereof; a conductive organic material, a polymer compound, a mixture of a conductive organic compound and a polymer compound, a hole injection material, a hole transport material, an electron transport material, a host material, a material for the dopant;

In one embodiment, by adjusting the thickness of the functional layer or the transparent upper electrode, the mutual reinforcement and interference of the light emitted from the organic EL device can be adjusted.

In one embodiment, the reflective layer may have a reflectance of 20% or more.

In one embodiment, the reflective layer is used alone or two or more of these materials including any one or more selected from aluminum, magnesium, silver, gold, platinum, chromium, cobalt, tungsten, calcium, lithium, sodium. Composed of components, the thickness may range from 1 nm to 5000 nm.

In one embodiment, the organic thin film layer, at least one of a functional layer having a hole injection layer, a hole transport layer, an electron blocking layer, a hole injection function and a hole transport function at the same time, a light emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer It may include. In this case, the present invention includes at least one of a hole injection layer, a hole transport layer, an electron blocking layer, a function layer having a hole injection function and a hole transport function included in the organic thin film layer, a light emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer. One or more thicknesses can be varied to control the mutual reinforcement and interference of light.

In an embodiment, the light emitting layer may emit light by a combination of a host and a dopant.

In one embodiment, the reflective layer or functional layer may be connected to the light transmissive upper electrode by ohmic contact to lower the resistance of the light transmissive upper electrode.

As an embodiment, a capping layer may be further provided between the lower electrode layer and the substrate layer or by preventing total reflection of light on the outer surface of the substrate layer to increase the luminous efficiency of the organic light emitting material.

In one embodiment, the organic electroluminescent device includes a blue light emitting material, a green light emitting material or a red light emitting material emitting light in the wavelength range of 380 nm to 800 nm, the blue light emitting material, green light emitting material or red light emitting material It may be a fluorescent material or a phosphorescent material.

In another aspect, the present invention comprises the steps of forming a lower electrode on the transparent substrate; Forming an organic thin film layer including a light emitting layer on the lower electrode; Forming a translucent upper electrode on the organic thin film layer; Forming a functional layer that mutually reinforces and interferes with light transmitted on the upper electrode; And it provides a method of manufacturing an organic electroluminescent device comprising the step of forming a reflective layer on the functional layer.

The present invention is formed by adjusting the thickness of the functional layer or the transparent upper electrode, it is possible to control the mutual reinforcement and interference of light emitted in the organic EL device.

The organic thin film layer may include at least one of a hole injection layer, a hole transport layer, an electron blocking layer, a layer having a hole injection function and a hole transport function, a light emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer. It may include.

In this case, the lower electrode, the organic thin film layer, the hole injection layer, the hole transport layer, the electron blocking layer, a functional layer having a hole injection function and a hole transport function at the same time, a light emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer, light transmittance At least one layer selected from the upper electrode, the functional layer, and the reflective layer may be formed by a deposition process or a solution process.

In addition, the present invention is to mutually reinforce the light by changing the thickness of at least one of the hole injection layer, the hole transport layer, the hole injection function and the hole injection function, the light emitting layer, the hole blocking layer, the electron transport layer, and the electron injection layer at the same time Interference can be adjusted.

In one embodiment, the functional layer may be formed by a deposition process or a solution process.

In the present invention, a transparent upper electrode is additionally provided as an upper electrode on the organic thin film layer including the light emitting layer, and a functional layer is formed thereon. It can have the characteristics of longevity and high efficiency.

In addition, the device structure of the present invention has a structure that is easy to manufacture a large area of the device is simple manufacturing process, has excellent process yield, has the advantage of making a device having a high color reproducibility.

1 is a view showing the structure of an organic EL device according to the prior art.

2 is a diagram illustrating an example of light emission of an organic EL device according to an embodiment of the present invention.

3 is a diagram illustrating the structure of an organic EL device according to an embodiment of the present invention.

4 is a diagram illustrating a simulation of the EL spectrum according to the thickness change of the functional layer of the organic electroluminescent device according to the present invention.

5 is a diagram showing the intensity of the spectrum due to the thickness change of the functional layer and the HTL layer as an embodiment of the present invention.

FIG. 6 is a diagram illustrating a result of normalizing light emission characteristics of the device of FIG. 5.

7 is a diagram showing the life characteristics of the organic light emitting device manufactured by the present invention.

Hereinafter, an organic light emitting diode display according to an exemplary embodiment of the present invention will be described with reference to the accompanying drawings.

2 is a diagram illustrating an example of light emission of an organic EL device according to an embodiment of the present invention. As shown in FIG. 2, the organic light emitting diode display according to the exemplary embodiment of the present invention includes a lower electrode 20 formed on the light transmissive substrate 10; An organic thin film layer 30 to 60 formed on the lower electrode 20 and including a light emitting layer; A translucent upper electrode 71 formed on the organic thin film layer; A functional layer 80 formed on the upper electrode 71 to mutually reinforce and interfere with transmitted light; And a reflective layer 90 formed on the functional layer.

The substrate 10 is a light transmissive and electrically insulating substrate including glass, a polymer, or the like, and is preferably excellent in mechanical strength or dimensional stability.

Such substrates include substrates composed of inorganic materials, such as glass plates, metal plates, ceramic plates, and the like, and preferred inorganic materials include glass substrates, silicon oxides, aluminum oxides, titanium oxides, yttrium oxides, germanium oxides, and zinc oxides. , Magnesium oxide, calcium oxide, strontium oxide, barium oxide, lead oxide, sodium oxide, zirconium oxide, lithium oxide, boron oxide, silicon nitride, soda lime glass, barium strontium-containing glass, lead glass, aluminosilicate glass, borosilicate Glass and barium borosilicate glass.

In addition, preferred organic materials constituting the substrate include polycarbonate resins, acrylic resins, vinyl chloride resins, polyethylene terephthalate resins, polyimide resins, polyester resins, epoxy resins, phenol resins, silicone resins, fluorine resins, and polyvinyl alcohols. Resins, polyvinylpyrrolidone resins, polyurethane resins, epoxy resins, cyanate resins, melamine resins, malee resins, vinyl acetate resins, polyacetal resins, cellulose resins and the like.

In addition, in order to prevent the ingress of moisture into the organic electroluminescent display, it is preferable to form more inorganic films, apply fluorine resin, moisture-proof treatment or hydrophobic treatment on the substrate made of the material. It is desirable to reduce the moisture content and gas permeability coefficient of the substrate to prevent moisture from invading the light emitting medium.

Hereinafter, referring to the upper electrode and the lower electrode, the lower electrode 20 is a translucent electrode, and in the case of the bottom emission, the anode is a hole injection electrode, and the upper electrode 71 is an electron injection electrode. (cathode). However, embodiments of the present invention are not necessarily limited thereto, and the lower electrode 20 may be a cathode and the upper electrode 71 may be an anode according to a driving method of the organic EL device.

When the lower electrode 20 is an anode, the preferred anode layer is a metal, alloy, electrically conductive compound or mixture thereof having a high work function (eg, 4.0 eV or more). Specifically, electrode materials such as indium tin oxide (ITO), indium zinc oxide (IZO), indium copper (CuIn), tin oxide (SnO ₂ ), zinc oxide (ZnO), gold, platinum, palladium, or the like are used alone or in combination thereof. It is preferable to use combining 2 or more types of electrode materials. By using such an electrode material, methods such as vacuum deposition, sputtering, ion plating, electron beam deposition, chemical vapor deposition (CVD), metal oxide chemical vapor deposition (MOCVD), plasma CVD and the like that can be deposited in a dry state Through this, an anode layer having a uniform thickness may be formed.

The film thickness of the anode layer is not particularly limited, but is preferably 1 nm to 1000 nm.

The lower electrode 20 may be formed of a single layer such as transparent and highly conductive indium tin oxide (ITO), indium zinc oxide (IZO) tin oxide (SnO ₂ ), zinc oxide (ZnO), or the like. It may comprise a multilayer of a light-transmitting conductive material.

Holes and electrons are injected into the light emitting layer from the lower electrode 20 and the upper electrode 71, respectively. When exciton in which holes and electrons are injected into the light emitting layer falls from the excited state to the ground state of the organic light emitting layer, Light emission is achieved.

In addition, in the present invention, an auxiliary electrode 25 made of a metal component such as Cr, Mo, Al, Ag, or an alloy thereof may be formed on the edge of the lower electrode.

The auxiliary electrode 25 is inserted into the edge of the lower electrode by using a metal component having a low resistance value, thereby lowering the sheet resistance value of the positive electrode ITO, thereby ensuring uniformity of luminance even if the ITO area is increased. .

The auxiliary electrode formed on the lower electrode 20 may be formed by a process such as sputtering, thermal deposition, E-Beam thermal deposition, ion beam sputtering, or the like.

In addition, the present invention can form an insulating film 27 on the lower electrode and the auxiliary electrode. As the constituent material of the insulating film 27, a polymer material or an inorganic material such as an inorganic oxide may be used.

As said polymer material, acrylic resin, polycarbonate resin, polyimide resin, fluorinated polyimide resin, benzoguanamine resin, melamine resin, cyclic polyolefin, novolak resin, vinyl cinnamic acid, cyclized rubber, polyvinyl chloride resin, polystyrene , Phenol resins, alkyd resins, epoxy resins, polyurethane resins, polyester resins, maleic acid resins, polyamide resins, and the like.

In addition, when the insulating film is made of an inorganic oxide, preferred inorganic oxides are silicon oxide (SiO ₂ or SiOx), aluminum oxide (A1 ₂ O ₃ , AlON or AlOx) titanium oxide (TiO ₂ ), yttrium oxide (Y ₂ O _3). Or YOx), germanium oxide (GeO ₂ or GeOx), zinc oxide (ZnO), magnesium oxide (MgO or MgOx), calcium oxide (CaO), boric acid (B ₂ O ₃ ), strontium oxide (SrO), barium oxide ( BaO), lead oxide (PbO), zirconia (ZrO ₂ ), sodium oxide (Na ₂ O), lithium oxide (Li ₂ O), potassium oxide (K ₂ O), and the like. In particular, when heat resistance is required, the constituent materials of the insulating film are preferably acrylic resins, polyimide resins, fluorinated polyimides, cyclic polyolefins, epoxy resins, and inorganic oxides.

Moreover, it is preferable that these interlayer insulation films are processed into a desired pattern by the photolithographic method by introducing a photosensitive group, or formed into a desired pattern by the printing method.

The thickness of the insulating film 27 depends on the process conditions or the requirements of the device, but is preferably 10 nm to 1 mm, preferably 100 nm to 100 μm, more preferably 100 nm to 10 μm.

In the present invention, the organic thin film layers 30 to 60 are provided on the lower electrode 20. As used herein, the term "organic thin film layer" refers to a single and / or a plurality of layers interposed between the first electrode and the second electrode of the organic EL device, wherein the organic thin film layer includes a light emitting layer, and the light emitting layer is formed of a host. An organic light emitting material comprising a dopant may be included.

In the present invention, the organic thin film layers 30 to 60 including the light emitting layer may have a hole injection layer 30, a hole transport layer 40, a hole injection function, and a hole transport function at the same time (hereinafter, “H-functional layer (H−). functional layer), a buffer layer, an electron blocking layer, a light emitting layer 50, a hole blocking layer, an electron transporting layer 60, an electron injection layer and a layer simultaneously having an electron transporting function and an electron injection function (hereinafter referred to as "E- At least one of a functional layer ”.

Although the thickness of each layer in the said organic thin film layer is not specifically limited, For example, 5 nm-5 micrometers are preferable. This is because the emission luminance or durability may be lowered when the thickness of each layer is less than 5 nm, and the applied voltage may increase when the thickness is more than 5 μm. Thus, the thickness of each layer is more preferably 10 nm to 3 μm, most preferably 20 nm to 1 μm.

Meanwhile, in the present invention, the hole injection layer 30, the hole transport layer 40, a layer having a hole injection function and a hole transport function at the same time, a buffer layer, an electron blocking layer, a light emitting layer 50, a hole blocking layer, an electron transport layer 60 ), One or more layers selected from the electron injection layer and the layer having the electron transport function and the electron injection function at the same time may be formed by a single molecule deposition method or a solution process.

Here, the deposition method refers to a method of forming a thin film by evaporating a material used as a material for forming each layer by heating or the like in a vacuum or low pressure state, and the solution process forms the respective layers. A method of forming a thin film by mixing a material used as a material for the solvent with a solvent and inkjet printing, roll-to-roll coating, screen printing, spray coating, dip coating, spin coating and the like.

In addition, the organic light emitting device in the present invention is a flat panel display device; Flexible display devices; Monochrome or white flat lighting devices; And a solid or white flexible lighting device; can be used in any one device selected from.

The hole injection layer HIL may be formed on the lower electrode by using various methods such as vacuum deposition, spin coating, casting, and LB.

In the case of forming the hole injection layer by vacuum deposition, the deposition conditions vary depending on the compound used as the material of the hole injection layer, the structure and thermal properties of the hole injection layer, and the like. It may be selected from the range of about 500 ° C., a degree of vacuum of about 10 ⁻⁸ to about 10 ⁻³ torr, and a deposition rate of about 0.01 to about 100 μs / sec, but is not limited thereto.

In the case of forming the hole injection layer by spin coating, the coating conditions vary depending on the compound used as the material of the hole injection layer, the structure and the thermal characteristics of the desired hole injection layer, but are about 100 rpm to about 10000 rpm. The coating rate of, the heat treatment temperature for removing the solvent after coating may be selected from a temperature range of about 50 ℃ to 300 ℃, but is not limited thereto.

As the hole injection material, a well-known hole injection material can be used. For example, N, N'-diphenyl-N, N'-bis- [4- (phenyl-m- Tolyl-amino) -phenyl] -biphenyl-4,4′-diamine (N, N′-diphenyl-N, N′-bis- [4- (phenyl-m-tolyl-amino) -phenyl] -biphenyl- Phthalocyanine compounds such as 4,4´-diamine: DNTPD), copper phthalocyanine, m-MTDATA [4,4´, 4 ″ -tris (3-methylphenylphenylamino) triphenylamine], NPB (N, N´-di (1-naph) Tyl) -N, N´-diphenylbenzidine (N, N´-di (1-naphthyl) -N, N´-diphenylbenzidine), TDATA, 2-TNATA [4,4´, 4 ″ -tris (2 -naphthylphenyl-phenylamino) -triphenylamine], Pani / DBSA (Polyaniline / Dodecylbenzenesulfonic acid: polyaniline / dodecylbenzenesulfonic acid), PEDOT / PSS (Poly (3,4-ethylenedioxythiophene) / Poly (4-styrenesulfonate): poly (3, 4-ethylenedioxythiophene) / poly (4-styrenesulfonate)), Pani / CSA (Polyaniline / Camphor sulfonicacid: polyaniline / camphorsulfonic acid) or PANI / PSS (Polyaniline) / Poly (4-styrenesul fonate): polyaniline) / poly (4-styrenesulfonate)), and the like, but are not limited to:

The hole injection layer may have a thickness of about 1 nm to about 1000 nm, for example, about 100 kPa to about 1000 kPa. When the thickness of the hole injection layer satisfies the above range, a satisfactory hole injection characteristic may be obtained without a substantial increase in driving voltage.

Next, a hole transport layer (HTL) may be formed on the hole injection layer by using various methods such as vacuum deposition, spin coating, casting, and LB. In the case of forming the hole transport layer by vacuum deposition and spinning, the deposition conditions and coating conditions vary depending on the compound used, and in general, the hole transport layer may be selected from almost the same range of conditions as the formation of the hole injection layer.

As the hole transporting material, at least one of the styryl-based compound, the styryl-containing composition, and a known hole transporting material may be used. Known hole transport materials include, for example, N-phenylcarbazoles such as Compounds 101 to 104, carbazole derivatives such as polyvinylcarbazole, N, N'-bis (3-methylphenyl) -N, N '-Diphenyl- [1,1-biphenyl] -4,4'-diamine (TPD), TCTA (4,4', 4 "-tris (N-carbazolyl) triphenylamine (4,4 ', 4 "-tris (N-carbazolyl) triphenylamine)), NPB (N, N'-di (1-naphthyl) -N, N'-diphenylbenzidine (N, N'-di (1-naphthyl) -N , N'-diphenylbenzidine)), and diarylamine represented by the following Chemical Formula 105, but are not limited thereto.

[Compound 101] [Compound 102] [Compound 103]

[Compound 104] [Compound 105]

The hole transport layer may have a thickness of about 5 nm to about 200 nm, for example, about 10 nm to about 150 nm. When the thickness of the hole transport layer satisfies the above range, a satisfactory hole transport characteristic may be obtained without a substantial increase in driving voltage.

The H-functional layer (functional layer having a hole transport function at the same time) may include at least one of the hole injection layer material and the hole transport layer material as described above, the thickness of the H-functional layer is about 5 nm to about 1000 nm, for example, from about 10 nm to about 100 nm. When the thickness of the H-functional layer satisfies the above-described range, satisfactory hole injection and aqueous characteristics can be obtained without a substantial increase in driving voltage.

At least one of the hole injection layer, the hole transport layer, and the H-functional layer may have a conductivity of the film, in addition to a known hole injection material, a known hole transport material, and / or a material having a hole injection function and a hole transport function at the same time. The charge-generating material may be doped or additionally included in multiple layers to enhance the back and the like.

The charge-generating material may be, for example, a p-dopant. The p-dopant may be one of a quinone derivative, a metal oxide, and a cyano group-containing compound, but is not limited thereto. For example, non-limiting examples of the p-dopant include tetracyanoquinonedimethane (TCNQ) and 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinonedimethe. Quinone derivatives such as phosphorus (F4-CTNQ) and the like; Metal oxides such as tungsten oxide and molybdenum oxide; And cyano group-containing compounds such as Compound 200, and the like, but are not limited thereto.

<Compound 200> <F4-CTNQ>

When the hole injection layer, the hole transport layer or the H-functional layer further includes the charge-generating material, the charge-generating material is homogeneous in the hole injection layer, the hole transport layer or the H-functional layer. A variety of modifications are possible, such as dispersed or evenly distributed.

A buffer layer may be interposed between at least one of the hole injection layer, the hole transport layer, and the H-functional layer and the light emitting layer. The buffer layer may serve to compensate for an optical resonance distance according to the wavelength of light emitted from the light emitting layer and to confine electrons in the light emitting layer to increase efficiency. The buffer layer may comprise a known hole injection material, a hole transport material. Alternatively, the buffer layer may include the same material as one of the materials included in the hole injection layer, the hole transport layer, and the H-functional layer formed under the buffer layer.

Subsequently, the emission layer EML may be formed on the hole transport layer, the H-functional layer, or the buffer layer by using a method such as vacuum deposition, spin coating, cast, LB, or the like. When the light emitting layer is formed by a vacuum deposition method or a spin coating method, the deposition conditions vary depending on the compound used, and in general, may be selected from a range of conditions substantially the same as that of forming the hole injection layer.

The light emitting layer may include a dopant compound. Specific examples of the dopant material include pyrene compounds, arylamines, peryl compounds, pyrrole compounds, hydrazone compounds, carbazole compounds, stilbene compounds, starburst compounds, oxadiazole compounds, coumarine, etc. Although the present invention is not limited thereto.

The light emitting layer may further include a host in addition to the dopant compound.

As the host, Alq ₃ , CBP (4,4'-N, N'-dicarbazole-biphenyl), PVK (poly (n-vinylcarbazole)), 9,10-di (naphthalen-2-yl) Anthracene (ADN), TCTA, TPBI (1,3,5-tris (N-phenylbenzimidazol-2-yl) benzene (1,3,5-tris (N-phenylbenzimidazole-2-yl) benzene)), TBADN (3-tert-butyl-9,10-di (naphth-2-yl) anthracene), E3, DSA (distyrylarylene), dmCBP (see formula below), etc. may be used, but is not limited thereto. no.

PVK ADN

When the light emitting layer includes a host and a dopant, the content of the dopant may be generally selected from about 0.01 to about 15 parts by weight based on about 100 parts by weight of the host, but is not limited thereto.

In the present invention, the host used in the light emitting layer may be a compound represented by the following Chemical Formula 1A.

[Formula 1A]

In Chemical Formula 1A,

X ₁ to X ₁₀ are the same as or different from each other, and each independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, substituted or unsubstituted Substituted cycloalkyl group having 3 to 30 carbon atoms, substituted or unsubstituted cycloalkenyl group having 5 to 30 carbon atoms, substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, Substituted or unsubstituted alkyl thioxy group having 1 to 30 carbon atoms, substituted or unsubstituted arylthioxy group having 5 to 30 carbon atoms, substituted or unsubstituted alkylamine group having 1 to 30 carbon atoms, substituted or unsubstituted carbon atoms 5 to 30 An arylamine group having 30, a substituted or unsubstituted aryl group having 5 to 50 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 50 carbon atoms having O, N or S as a hetero atom, substituted Is an unsubstituted silicone, substituted or unsubstituted boron group, substituted or unsubstituted silane group, carbonyl group, phosphoryl group, amino group, nitrile group, hydroxy group, nitro group, halogen group, amide group and ester group And a condensed ring of aliphatic, aromatic, aliphatic or aromatic hetero with groups adjacent to each other.

In this case, the term "substituted or unsubstituted" is cyano group, halogen group, hydroxy group, nitro group, alkyl group, alkoxy group, alkylamino group, arylamino group, hetero arylamino group, alkylsilyl group, arylsilyl group, aryl jade It is meant to be substituted or unsubstituted with one or more substituents selected from the group consisting of a period, an aryl group, a heteroaryl group, germanium, phosphorus, boron, hydrogen and deuterium.

In the present invention, the anthracene derivative of Formula 1A may be a compound represented by Formula 1Aa.

Formula 1Aa]

In Formula 1Aa, Ar ₇ and Ar ₈ are the same as or different from each other, and are each independently a substituted or unsubstituted C ₅ -C ₆₀ aromatic linking group, or a substituted or unsubstituted C ₂ -C ₆₀ hetero. An aromatic linking group; R ₂₁ to R ₃₀ are the same as or different from each other, and each independently include the same substituent as defined in X ₁ to X ₁₀ ,

E and f are the same as or different from each other and are each independently an integer of 0 or 1 to 4, and in Formula 1Aa, two sites represented by * of the anthracene may be the same or different from each other, and each independently the P or It can be combined with the Q structure to form an anthracene-based derivative selected from Formulas 1Aa-1 to 1Aa-3.

[Formula 1Aa-1] [Formula 1Aa-2] [Formula 1Aa-3]

Here, the 'substituted' in the 'substituted or unsubstituted' is deuterium, cyano group, halogen group, hydroxy group, nitro group, alkyl group of 1 to 24 carbon atoms, halogenated alkyl group of 1 to 24 carbon atoms, of 1 to 24 carbon atoms Alkenyl group, C1-C24 alkynyl group, C1-C24 heteroalkyl group, C6-C24 aryl group, C6-C24 arylalkyl group, C2-C24 heteroaryl group, or C2-C24 hetero Arylalkyl group, alkoxy group having 1 to 24 carbon atoms, alkylamino group having 1 to 24 carbon atoms, arylamino group having 1 to 24 carbon atoms, heteroarylaryl group having 1 to 24 carbon atoms, alkylsilyl group having 1 to 24 carbon atoms, and 1 to 24 carbon atoms It means substituted with one or more substituents selected from the group consisting of an arylsilyl group, an aryloxy group having 1 to 24 carbon atoms.

In the present invention, the dopant may be a compound represented by the following [Formula 2] or [Formula 3].

[Formula 2] [Formula 3]

In [Formula 2] and [Formula 3],

A is an aromatic ring group having no heteroatom and is a substituted or unsubstituted aromatic ring group having 6 to 50 carbon atoms; Or an aromatic heterocyclic group having O, N or S as a hetero atom, a substituted or unsubstituted aromatic heterocyclic group having 2 to 50 carbon atoms, and when n is 2 or more, each of the amine groups bonded to A is the same as each other, or Can be different.

When A is an aromatic ring group having no heteroatom, A may be a compound represented by the following Formula A1 to Formula A10.

[Formula A1] [Formula A2] [Formula A3] [Formula A4] [Formula A5]

[Formula A6] [Formula A7] [Formula A8] [Formula A9] [Formula A10]

Here, Z ₁ and Z ₂ of [Formula A3] are each hydrogen, deuterium atom, substituted or unsubstituted C1-C60 alkyl group, substituted or unsubstituted C2-C60 alkenyl group, substituted or unsubstituted An alkynyl group having 2 to 60 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 60 carbon atoms, a substituted or unsubstituted alkylthio group having 1 to 60 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 60 carbon atoms , Substituted or unsubstituted aryl group having 6 to 60 carbon atoms, substituted or unsubstituted aryloxy group having 5 to 60 carbon atoms, substituted or unsubstituted arylthio group having 5 to 60 carbon atoms, substituted or unsubstituted carbon atoms 2 to A heteroaryl group of 60, a substituted or unsubstituted (alkyl) amino group having 1 to 60 carbon atoms, a di (substituted or unsubstituted alkyl group having 1 to 60 carbon atoms), or a (substituted or unsubstituted aryl having 6 to 60 carbon atoms Amino Groups, di (substituted or unsubstituted aryl having 6 to 60 carbon atoms) amino group, each of Z ₁ to Z ₂ is the same as or different from each other, and may form a condensed ring with a group adjacent to each other,

In Formula 2, X ₁ to X ₂ are the same as or different from each other, and each independently represent an unsubstituted or substituted arylene group having 6 to 30 carbon atoms or a single bond, and X ₁ and X ₂ may be bonded to each other. ; Y ₁ to Y ₂ are the same as or different from each other, and each independently substituted or unsubstituted aryl group having 6 to 24 carbon atoms, substituted or unsubstituted heteroaryl group having 2 to 24 carbon atoms, substituted or unsubstituted carbon number 1 An alkyl group of 24 to 24, a substituted or unsubstituted heteroalkyl group of 1 to 24 carbon atoms, a substituted or unsubstituted cycloalkyl group of 3 to 24 carbon atoms, a substituted or unsubstituted alkoxy group of 1 to 24 carbon atoms, a cyano group, a halogen group, Substituted or unsubstituted aryloxy group having 6 to 24 carbon atoms, substituted or unsubstituted alkylsilyl group having 1 to 40 carbon atoms, substituted or unsubstituted arylsilyl group having 6 to 30 carbon atoms, germanium, phosphorus, boron, deuterium and Selected from the group consisting of hydrogen, and may form a condensed ring of an aliphatic, aromatic, aliphatic or aromatic hetero group with adjacent groups, wherein l and m are each from 1 to 20 It is an integer and n is an integer of 1-4.

In the above [Formula 3], the C_yIs a substituted or unsubstituted cycloalkyl having 3 to 8 carbon atoms, b is an integer of 1 to 4, when b is 2 or more, each cycloalkane may be in a fused form. In addition, the hydrogen substituted therein may be each substituted with deuterium or alkyl, the same or different from each other, B Is a single bond or-[C (R₅) (R₆)]_pP is an integer of 1 to 3, and when p is 2 or more, 2 or more R₅ And R₆Are the same or different from each other; R_One, R₂, R_3,R₅ And R₆Are independently of each other hydrogen, deuterium, halogen atom, hydroxyl group, cyano group, nitro group, amino group, amidino group, hydrazine, hydrazone, carboxyl group or salt thereof, sulfonic acid group or salt thereof, phosphoric acid or salt thereof, substitution or Unsubstituted C1-C60 alkyl group, substituted or unsubstituted C2-C60 alkenyl group, substituted or unsubstituted C2-C60 alkynyl group, substituted or unsubstituted C1-C60 alkoxy group, substituted Or an unsubstituted C1-C60 alkylthio group, a substituted or unsubstituted C3-C60 cycloalkyl group, a substituted or unsubstituted C6-C60 aryl group, a substituted or unsubstituted C5-C5 60 aryloxy group, substituted or unsubstituted arylthio group having 5 to 60 carbon atoms, substituted or unsubstituted heteroaryl group having 2 to 60 carbon atoms, substituted or unsubstituted carbon atom having 1 to 60 carbon atoms (al ) Amino group, di (substituted or unsubstituted C1-C60 alkyl) amino group, or (substituted or unsubstituted C6-C60 aryl) amino group, di (substituted or unsubstituted C6-C60 aryl) amino group , Substituted or unsubstituted alkylsilyl group having 1 to 40 carbon atoms, substituted or unsubstituted arylsilyl group having 6 to 30 carbon atoms can be selected, a is an integer of 1 to 4, when a is 2 or more R₃Are the same as or different from each other, and R₃When there are plural, each R₃May be in fused form and n is an integer from 1 to 4.

Meanwhile, the thickness of the light emitting layer in the present invention may be about 10 nm to about 100 nm, for example, about 20 nm to about 60 nm. When the thickness of the light emitting layer satisfies the aforementioned range, the light emitting layer may exhibit excellent light emission characteristics without a substantial increase in driving voltage.

Next, an electron transporting layer (ETL) is formed on the light emitting layer by various methods such as vacuum deposition, spin coating, and casting. In the case of forming the electron transporting layer by vacuum deposition and spin coating, the conditions vary depending on the compound used, and in general, the electron transporting layer may be selected from a range of conditions substantially the same as the formation of the hole injection layer. As the electron transport layer material, a known electron transport material may be used as a function of stably transporting electrons injected from an electron injection electrode (Cathode). Examples of known electron transport materials include quinoline derivatives, in particular tris (8-quinolinorate) aluminum (Alq 3), TAZ, Balq, beryllium bis (benzoquinolin-10-noate) olate: Bebq ₂ ), ADN, compound 201, compound 202, oxadiazole derivatives such as PBD, BMD, BND may be used, but is not limited thereto.

 <Compound 201> <Compound 202> BCP

The electron transport layer may have a thickness of about 10 nm to about 100 nm, for example, about 15 nm to about 50 nm. When the thickness of the electron transporting layer satisfies the aforementioned range, a satisfactory electron transporting characteristic can be obtained without a substantial increase in driving voltage.

Alternatively, the electron transport layer may further include a metal-containing material, in addition to a known electron transport organic compound.

In the metal-containing compound, the metal-containing material may include a Li, Cs, Na, and Ca complex. Non-limiting examples of the Li complex include lithium quinolate (LiQ) or the following compound 203:

Compound 203

 In addition, an electron injection layer (EIL), which is a material having a function of facilitating injection of electrons from the cathode, may be stacked on the electron transport layer, which does not particularly limit the material.

As the electron injection layer forming material, any material known as an electron injection layer forming material such as CsF, NaF, LiF, NaCl, Li ₂ O, BaO, or the like may be used. Although the deposition conditions of the electron injection layer vary depending on the compound used, they may be generally selected from the same range of conditions as the formation of the hole injection layer.

The electron injection layer may have a thickness of about 1 kPa to about 100 kPa, about 3 kPa to about 90 kPa. When the thickness of the electron injection layer satisfies the aforementioned range, a satisfactory electron injection characteristic may be obtained without a substantial increase in driving voltage.

In addition, when the phosphorescent dopant or the fluorescent dopant is used as the light emitting layer, the triplet exciton or hole may be prevented from diffusing into the electron transport layer, and the holes may be trapped in the light emitting layer to improve efficiency. A hole blocking layer HBL may be formed using a method such as vacuum deposition, spin coating, cast, LB, or the like between the hole transport layer and the light emitting layer or between the H-functional layer and the light emitting layer. In the case of forming the hole blocking layer by vacuum deposition or spin coating, the conditions vary depending on the compound used, but can be generally within the same condition range as the formation of the hole injection layer. Known hole blocking materials can also be used, and examples thereof include oxadiazole derivatives, triazole derivatives, and phenanthroline derivatives. For example, the following BCP can be used as the hole blocking layer material.

 The hole blocking layer may have a thickness of about 20 kPa to about 1000 kPa, for example, about 30 kPa to about 300 kPa. When the thickness of the hole blocking layer satisfies the aforementioned range, excellent hole blocking characteristics may be obtained without a substantial increase in driving voltage.

On the other hand, the upper electrode 71 of the present invention is made of a metal, alloy, electrically conductive compound or a mixture or inclusion thereof having a small work function.

In addition, since the upper electrode 71 must transmit the emitted light to the functional layer, the upper electrode 71 should have good light transmittance as well as conductivity.

The upper electrode may have a transmittance of 10% or more. It may be preferably at least 20%, more preferably at least 30%, more preferably at least 40%, more preferably at least 50%, more preferably at least 60%, more preferably Preferably 70% or more, more preferably 80% or more, and more preferably 90% or more.

In addition, the resistance value of the upper electrode may have a range of 0.1 mΩ to 500 Ω, preferably 1 mΩ to 100Ω.

Specifically, materials used for the upper electrode include copper, chromium, molybdenum, nickel, aluminum, magnesium, silver, gold, platinum, indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), and ZnO / Ga. ₂ O ₃ , ZnO / Al ₂ O ₃ , sodium, sodium-potassium alloy, cesium, magnesium, lithium, magnesium-silver alloy, aluminum oxide, aluminum-lithium alloy, indium, rare earth metals, these metals and organic light emitting media materials An electrode material composed of a mixture, a mixture of these metals and an electron injection layer material, or the like may be used alone, or two or more thereof may be used in combination.

Preferred materials for the upper electrode include magnesium (Mg), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), and the like. Can be.

In addition, the film thickness of the upper electrode layer is not particularly limited, but is preferably 1 to 1,000 nm, more preferably 1 to 200 nm, the refractive index of the upper electrode is selected from any material having a value in the range of 0.1 to 10 Can be used by

The upper electrode 71 may be formed by a conventional method, but is formed by vacuum deposition or spin coating to minimize deterioration due to thermal damage of the previously deposited organic thin film layer. In this case, it is possible to minimize life degradation due to thermal damage of the organic thin film layer, which may be caused when sputtering and film formation at a high temperature.

In addition, in the present invention, when the functional layer is conductive, it may be connected to the translucent upper electrode to improve the conductivity of the upper electrode.

In addition, the functional layer is preferably made of a light transmitting material in order to reduce the loss during light transmission.

In addition, the material used for the functional layer is preferably a material having a low light absorption characteristics so that the loss of light.

As a material of the said functional layer, Inorganic material of a metal oxide or a metal nitride; Organic materials such as conductive organic materials, polymer compounds, mixtures of conductive organic compounds and polymer compounds, hole injection materials, hole transport materials, electron transport materials, host materials, and dopant materials; any one or a combination thereof may be used. May be, but is not limited to.

As the metal oxide or metal nitride corresponding to the inorganic material, oxides, nitrides, etc. of metals such as In, Sn, Zn, Ti, Zr, Hf, V, Mo, Cu, Ga, Sr, La, Ru, etc. may be used. Specific examples include ITO, IZO, AZO, SnOx, SiNx, ZnOx, TiN, ZrN, HfN, TiOx, Nb ₂ O ₅ , VOx, MoOx, CuI, InN, GaN, TiO ₂ , CuAlO ₂ , CuGaO ₂ , SrCu ₂ O ₂ Conductive or insulating transparent materials such as, LaB ₆ , RuOx and the like may be used.

In addition, as the organic material, the conductive organic material is PEDOT poly (3,4-ethylenedioxythiophene) = / PSS (polystyrene parasulfonate), starburst material, arylamine type, perylene type, carbazole type, hydrazone type, stilbene group and pyrrole group One synthetic polymer having a hole transporting capacity selected from; Or polystyrene, poly (styrene-butadiene) copolymer, polymethylmethacrylate, polyalphamethylstyrene, styrene-methylmethacrylate copolymer, polybutadiene, polycarbonate, polyethylterephthalate, polyestersulfonate, polyaryllay And at least one polymer selected from the group consisting of fluorinated polyimides, transparent fluorine resins and transparent acrylic resins, and starbursts including arylamines, phenylenes, carbazoles, stilbenes, pyrroles and derivatives thereof. 1 type of polymer, oxazole type compound, isoxazole type compound, triazole type compound, isothiazole type compound, oxa selected from the group which consists of the mixture which disperse | distributed the low molecule which has at least 1 type of hole transport ability selected from the group Diazole compounds, thiadiazole compounds, perylene compounds, Aluminum complexes such as Alq ₃ (tris (8-quinolinolato) -aluminum) BAlq, SAlq, Almq ₃ , gallium complexes such as Gaq'2OPiv, Gaq'2OAc, 2 (Gaq'2)) and the like can be used.

The present invention also relates to N, N'-diphenyl-N, N'-bis- [4- (phenyl-m-tolyl-amino) -phenyl] -biphenyl-4,4'-diamine (N) as the organic material. , N´-diphenyl-N, N´-bis- [4- (phenyl-

m-tolyl-amino) -phenyl] -biphenyl-4,4´-diamine: DNTPD), phthalocyanine compounds such as copper phthalocyanine, m-MTDATA [4,4 ', 4''-tris (3-methylphenylphenylamino) triphenylamine] , NPB (N, N'-di (1-naphthyl) -N, N'-diphenylbenzidine), TDATA, 2 -N, N'-di (1-naphthyl) -N, N'-di (1-naphthyl) -N, N'-diphenylbenzidine) TNATA, Pani / DBSA (Polyaniline / Dodecylbenzenesulfonic acid: Polyaniline / Dodecylbenzenesulfonic acid), PEDOT / PSS (Poly (3,4-ethylenedioxythiophene) / Poly (4-styrenesulfonate): Poly (3,4-ethylenedioxythiophene) Poly (4-styrenesulfonate)), Pani / CSA (Polyaniline / Camphor sulfonicacid: polyaniline / camphorsulfonic acid) or PANI / PSS (Polyaniline) / Poly (4-styrenesulfonate): polyaniline) / poly (4-styrenesulfonate Hole injection materials such as;); Carbazole derivatives such as N-phenylcarbazole and polyvinylcarbazole, N, N'-bis (3-methylphenyl) -N, N'-diphenyl- [1,1-biphenyl] -4,4'- Diamine (TPD), TCTA (4,4 ', 4 "-tris (N-carbazolyl) triphenylamine (4,4', 4" -tris (N-carbazolyl) triphenylamine)), NPB (N, N ' Hole transport materials such as -di (1-naphthyl) -N, N'-diphenylbenzidine (N, N'-di (1-naphthyl) -N, N'-diphenylbenzidine)); Quinoline derivatives, in particular tris (8-quinolinorate) aluminum (Alq ₃ ), TAZ, Balq, beryllium bis (benzoquinolin-10-noate) (beryllium bis (benzoquinolin-10-olate: Bebq ₂ ), ADN, etc. Electron transport materials for dopants such as pyrene-based compounds, arylamines, peryl compounds, pyrrole compounds, hydrazone compounds, carbazole compounds, stilbene compounds, starburst compounds, oxadiazole compounds, and coumarine Substances: Alq3, anthracene compound, CBP (4,4'-N, N'-dicarbazole-biphenyl), PVK (poly (n-vinylcarbazole)), TCTA, TPBI (1,3,5-tris For host such as (N-phenylbenzimidazol-2-yl) benzene (1,3,5-tris (N-phenyl benzimidazole-2-yl) benzene)), E3, DSA (distyryl arylene), dmCBP Substance; is usable.

In addition, as the organic material, the polymer compound is typically an acrylic resin, a polycarbonate resin, a polyimide resin, a fluorinated polyimide resin, a benzoguanamine resin, a melamine resin, a cyclic polyolefin, a novolak resin, vinyl cinnamic acid, a cyclized rubber, a polychlorinated compound. Vinyl resin, polystyrene, phenol resin, alkyd resin, epoxy resin, polyurethane resin, polyester resin, maleic acid resin, polyamide resin and the like can be used.

In addition, a mixture of the conductive organic material and the polymer compound may be used as the functional layer of the present invention.

In addition, the functional layer 80 may also be processed into a desired pattern by photolithography by introducing a photosensitive group, and also by vacuum deposition or spin coating to minimize degradation due to thermal damage of the previously deposited organic thin film layer. It is preferably formed.

The thickness of the functional layer 80 depends on the process conditions or the requirements of the device, but is preferably 0.5 nm to 1 mm, preferably 1 nm to 100 μm, more preferably 10 nm to 10 μm.

The functional layer should include a light transmitting property, the preferred light transmittance is preferably in the range of 5 to 100%.

On the other hand, the reflective layer 90 in the present invention serves to reflect the light emitted from the organic thin film layer passed through the functional layer.

The reflective layer may have a reflectance of 20% or more. Preferably it may be at least 30%, more preferably at least 40%, more preferably at least 50%, more preferably at least 60%, more preferably at least 70%, more preferably Preferably it may be 80% or more, more preferably 90% or more.

The reflective layer may be made of a material using a material containing any one or more selected from aluminum, magnesium, silver, gold, platinum, chromium, cobalt, tungsten, calcium, lithium, and sodium or a combination of two or more of these materials. Preferably, Al, Ag can be used.

Although the film thickness of the said reflection layer is not specifically limited, In order to make thickness of an element thin, it can form in the range of 1 nm-5000 nm, Preferably it can be 10 nm-300 nm.

In addition, the upper electrode 90 may be formed by a conventional method, but may be formed by a vacuum deposition method or a spin coating method in order to minimize degradation due to thermal damage of the previously deposited organic thin film layer.

On the other hand, the present invention may be provided with a capping layer between the lower electrode layer and the substrate layer, or to maximize the respective luminous efficiency for the color coordinates of R, G and B of the light emitting material on the outer surface of the substrate layer. The capping layer may be composed of an organic material or an inorganic material.

The organic material or the inorganic material used in the capping layer may have a refractive index of 1 to 10, thereby preventing total reflection of light when light passes through the interface with different constituents, thereby preventing the luminous efficiency of R, G, and B. Can increase. The thickness of the capping layer may be laminated in the range of 1 nm to 120 nm.

In the present invention, the organic electroluminescent device includes a blue light emitting material, a green light emitting material or a red light emitting material emitting light in the wavelength range of 380 nm to 800 nm, the blue light emitting material, green light emitting material or red light emitting material is fluorescent Material or phosphorescent material.

In addition, the substrate may include a wiring unit capable of driving the organic EL device. The wiring unit includes a switching and driving thin film transistor (not shown), and drives the organic EL device by providing a signal to allow the organic light emitting material to emit light.

The wiring unit may further include a gate line disposed in one direction of the substrate 10, a data line insulated from the gate line, a common power line, and the like.

In another aspect, the present invention comprises the steps of forming a lower electrode on the transparent substrate; Forming an organic thin film layer including a light emitting layer on the lower electrode; Forming a light transmissive upper electrode on the organic thin film layer; Forming a functional layer that mutually reinforces and interferes with light transmitted on the upper electrode; And it provides a method of manufacturing an organic electroluminescent device comprising the step of forming a reflective layer on the functional layer.

In this case, the functional layer may be formed by a deposition process or a solution process.

The deposition process means that a material constituting the functional layer is evaporated by a heating source to form a functional layer on the substrate, and the solution process is a state in which a material constituting the functional layer is dissolved in a solvent. This means that the functional layer is formed on the substrate by spin coating or printing.

In the present invention, the organic thin film layer may include at least one selected from a hole injection layer, a hole transport layer, an electron blocking layer, a function layer having a hole injection function and a hole transport function, a light emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer. It may comprise a layer.

In this case, at least one or more of the lower electrode, the organic thin film layer, the light transmissive upper electrode, the functional layer, and the reflective layer may be formed by a solution process.

In an embodiment, the organic light emitting diode display including the organic light emitting diode according to the present invention may include a switching thin film transistor, a driving thin film transistor, a power storage element, an organic electroluminescent element, and the like, respectively formed for each pixel.

In addition, an absorbent 95 is provided as a sealing member to exclude the influence of moisture in the air in the opposite direction of the substrate, which is the upper side of the organic EL device, and is included during the formation of the organic EL device or penetrated from the outside. It can absorb moisture.

Hereinafter, the operation of the organic EL device of the present invention will be described in detail.

When voltage is applied between the lower electrode 20 formed on the transparent substrate 10 and the transparent upper electrode 71 formed on the organic thin film layer, holes injected from the anode, which is the lower electrode, are transferred to the light emitting layer via the hole transport layer. The electrons injected from the cathode, which is the upper electrode, move to the light emitting layer via the electron transport layer. Carriers such as holes and electrons recombine in the emission layer to generate excitons. The excitons change from excited state to ground state and light is generated.

At this time, the generated light goes straight in the positive electrode direction and the negative electrode direction and various directions, and the light that goes straight to the positive electrode passes through the glass and exits the air layer, and the light that goes straight to the negative electrode passes through the light-transmissive upper electrode 71 to the upper electrode. After passing through the functional layer 80 formed on the functional layer to mutually reinforce and interfere with the transmitted light, it is reflected by the reflective layer 90 formed on the functional layer and passes through the functional layer toward the substrate through the upper electrode. It proceeds and is delayed than the light which goes straight toward the positive electrode and is emitted.

In this case, the light reflected by the reflective layer 90 may cause reinforcement or destructive interference with light traveling straight toward the anode by the functional layer and the organic thin film layer whose thickness is preset, thereby adjusting the characteristics of the spectrum. According to such an interference effect of light, the organic electroluminescent device of the present invention can provide an organic light emitting device having high chromaticity and high efficiency by having a sharp peak at a specific wavelength of light emitted.

Hereinafter, an organic electroluminescent device embodied through Examples based on FIG. 3 will be described in more detail, but the present invention is not limited to the following Examples.

EXAMPLE

Example: Fabrication of Devices

1. Si _x N _y is formed in the soda-lime glass 10 by a sputtering method so as to have a thickness of 25 nm so that Na ions do not diffuse into the transparent conductive film.

As the lower electrode 20, the transparent conductive film ITO is deposited by sputtering to have a thickness of 50 nm, and then an auxiliary electrode 25 made of Cr and Mo is deposited.

2. Thereafter, an exposure process for forming the auxiliary electrode 25 pattern is performed. At this time, PR is formed by screen printing, and then an acidic solution is used as Cr and Mo etchant, and the light emitting unit is exposed using an exposure and etching method. The auxiliary electrode 25 is formed outside.

3. Then, in order to form the insulating film 27 pattern, a polyimide-based material having excellent insulation and a photosensitive and viscous material such as a photoresist, and uniformly using a spin coating method on the upper surface of the ITO After coating, the substrate is exposed and exposed using an exposure mask, and then developed and etched to have a predetermined pattern to produce a substrate having an insulating film pattern having a polygon or curvature.

4. The hole injection layer 30 (HIL), the hole transport layer 40 (HTL), the light emitting layer 50 (EML), the electron transport layer 60, as shown in Fig. 3, on the transparent conductive film (ITO) substrate having the insulating film 27 ETL), the electron injection layer (EIL), and the upper electrode 71 are deposited in the following manner.

After mounting the ITO glass having the insulation film pattern formed in the vacuum chamber and having a base pressure of 1 × 10 ⁻⁷ torr, DNTPD was deposited on the ITO to form a hole injection layer having a thickness of 400 kV or 840 kPa, Α-NPB was deposited on the hole injection layer to change the thickness to 250 to 1200 Å to form a hole transport layer. Β-ADN was used as a host on the hole transport layer, and Compound 250] (3% by weight) was co-deposited as a dopant to form a light emitting layer having a thickness of 250 μs. Then, Alq ₃ was deposited on the light emitting layer to form a 300 μm thickness. The electron transport layer of was formed.

Subsequently, after forming a 5F thick LiF electron injection layer, MgAg was formed as the upper electrode 71 by vapor deposition.

[DNTPD] [α-NPB] [β-ADN]

[Compound 400] [Alq3]

The upper electrode 71 formed Mg and Ag in a ratio of 9: 1 to have light transmittance, and the formed electrode thickness had a thickness of 145 145.

5. Subsequently, N, N'-diphenyl-N, N'-bis- [4- (phenyl-m-tolyl-amino) -phenyl] -ratio to form the functional layer 80 of the present invention. Using phenyl-4,4 ';-diamine (DNTPD), functional layers having a thickness of 100 nm to 130 nm were formed by vacuum thermal evaporation, respectively, and as the reflective layer 90, aluminum (Al) having a thickness of 100 nm. Was deposited in vacuo to form a reflective layer, to fabricate the organic EL device of the present invention.

Comparative Example: Fabrication of Devices

Al was used as a cathode functioning as a reflective layer according to the prior art, without forming a functional layer and a reflective layer in the present invention, and the thickness of each layer was the same as in the above-described embodiment except for the parts shown in Table 1 below. An organic electroluminescent device was produced.

Device performance evaluation

4 shows the result of normalizing the EL spectrum according to the change of the thickness of the functional layer according to the present invention. This is a result implemented through optical simulation of the organic light emitting device according to the present invention by changing the thickness of the functional layer with the remaining layers except the functional layer under the same conditions, it is possible to evaluate the change in the EL spectrum accordingly.

More specifically, when the thickness of the functional layer is 70 nm, the wavelength corresponding to the maximum intensity is formed in the vicinity of 500 nm, but when the thickness of the functional layer becomes thick to 80 nm, the wavelength shifts to shorter wavelength, and the thickness of the functional layer is 100 nm. As it gets thicker, it shows a shift to longer wavelengths.

Table 1, Figure 5 and Figure 6 shows the light emission characteristics of the device according to the embodiment and the comparative example and will be described in detail.

Table 1 below describes the test results of the thickness and luminous efficiency data of each layer according to the Examples and Comparative Examples. More specifically, the results in Table 1 below, after fixing the thickness of the hole injection layer (84 nm), the light emitting layer (20 nm), the electron injection layer (30 nm) the thickness of the hole transport layer is changed from 84 nm to 130 nm, It is obtained by changing the thickness of the functional layer to a thickness of 110 nm to 130 nm. At this time, as the comparative element Ref, the spectrum of the organic EL element manufactured by the method described in the comparative example is shown, and the rest is produced by the element structure according to the present invention.

Table 1

Here, HIL represents a hole injection layer, HTL represents a hole transfer layer, MgAg represents an upper electrode, and V represents a voltage applied to both ends, and the results were tested under the condition of 10 mA / cm ² .

Looking at the results shown in Table 1, it is indicated that the lowest CIEy value can be represented by adjusting the thickness of the HTL layer and the functional layer. More specifically, it can be seen from Table 1 that the HTL layer has a thickness of 120 nm and the functional layer has the lowest CIEy value when the thickness is 120 nm.

In addition, as shown in Table 1, when comparing Example 4 with Example 5, the HTL layer causes the phenomenon that the color coordinate CIEy value rises again around 120 nm. It has a moderate half width when the HTL layer is 120 nm and shows the lowest CIEy. This shows the maximum resonance effect at the main wavelength of 455 nm while the intensity of the spectrum is optimal (Example 6). In Example 5, the half width is small, but the resonance spectrum occurs at 480 nm or more, resulting in a rise in CIEy.

In Example 7, the intensity of the main wavelength in the resonant structure is high, but the half width of the spectrum is widened, thereby increasing the CIEy.

The emission characteristics of the organic EL device according to the present invention will be described in more detail with reference to FIGS. 5 and 6.

FIG. 5 is a diagram illustrating the intensity of the EL spectrum obtained by changing the thicknesses of the HTL layer and the functional layer without normalization. Referring to FIG. 5, as shown in Table 1, the HTL layer ( 84 nm to 130 nm) and the thickness of the functional layer (100 nm to 130 nm) were varied and the thickness of the remaining layers was fixed to evaluate the characteristics of the device to show the intensity of the spectrum.

6 illustrates a normalized spectrum based on the result of FIG. 5.

5 and 6, the light emission characteristics of the device are described in detail. When the thickness of the functional layer is changed from 110 nm to 130 nm (Examples 5, 6, and 7), the intensity of the spectral dominant wavelength is 450 to 456. When the thickness of the functional layer is 120 nm while moving between nm, the intensity of the dominant wavelength is increased and the half width of the EL spectrum is appropriately reduced. This shows that the wavelength above 460 nm decreases with extinction interference, and the wavelength below 460 nm causes constructive interference, resulting in high intensity.

In addition, as shown in FIG. 6, when the thickness of the functional layer is increased to 120 nm or more, the half width of the spectrum is increased again. The wavelength of the functional layer is mainly reduced at 460 nm, and the interference is changed to constructive interference. Because.

In the spectrum of FIG. 6, when the HTL layer and the functional layer are 120 nm (Example 6), the intensity of the wavelength of 470 nm or more is decreased while the wavelength intensity of 455 nm has the optimum resonance.

This means that when the HTL layer and the functional layer are 120 nm, the intensity of the 460 nm wavelength is enhanced by the constructive interference, and the intensity of the wavelength becomes stronger, and more than 470 nm proves the disappearance interference phenomenon. Thus, the thickness of the functional layer to increase the intensity of 455 nm using the thickness of the functional layer and the wavelength of the wavelength of more than 470 nm to reduce the intensity of the wavelength of more than 470 nm to obtain a thickness of the functional layer to obtain a resonance structure having an optimal color coordinate and wavelength intensity to 120 nm have.

The result is to evaluate the device characteristics when the thickness of the hole injection layer, the hole transport layer, the light emitting layer, and the electron injection layer is fixed, and if the thickness of the other layer is changed, the HTL layer and the functional layer The thickness can be any thickness other than 120 nm.

Moreover, the result of the lifetime of the organic light emitting element manufactured by this invention is shown in FIG. In more detail, FIG. 7 is a graph showing device life evaluation in the device (Example 6) in which the thickness of the HTL and the functional layer is 120 nm and the device using the conventional technique (Comparative Example).

Comparing the life (square) to which the device structure of Example 6 is applied and the device (circle) manufactured as a comparative example, the life time of T97 (the time from initial luminance to 3% reduction) of Example 6 is 180 hours and that of Comparative Example T97 life was 150 hours. Here, the initial luminance of the lifetime of Example 6 and Comparative Example is 1500 cd / m ² .

Therefore, the life characteristics of Example 6 showed the same or more lifespan than the device fabricated by the method of Comparative Example, and it can be seen that the device according to the present invention realizes longer life characteristics.

The present invention can manufacture an organic light emitting device having characteristics of high colorability, high brightness, long life and high efficiency, and also has a structure that is simple to manufacture a device having a large manufacturing area and has high color reproducibility. An organic light emitting device having a structure can be produced.

Claims (25)

A lower electrode formed on the light transmissive substrate; An organic thin film layer formed on the lower electrode and including a light emitting layer; A light transmissive upper electrode formed on the organic thin film layer; A functional layer formed on the upper electrode and mutually reinforcing and interfering transmitted light; And a reflective layer formed on the functional layer. The method of claim 1, The organic electroluminescent device is an organic electroluminescent device, characterized in that provided with an auxiliary electrode formed on the edge on the lower electrode. The method of claim 1, The lower electrode is a conductive transparent electrode, characterized in that the organic light emitting device having a thickness of 1 nm to 1000 nm. The method of claim 1, The upper electrode has a transmittance of 10% or more, An organic electroluminescent device, characterized in that the resistance value ranges from 0.1 mΩ to 500 Ω. The method of claim 1, The upper electrode has a thickness in the range of 1 nm to 1000 nm, The upper electrode materials are copper, chromium, molybdenum, nickel, aluminum, magnesium, silver, gold, platinum, indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), ZnO / Ga ₂ O ₃ , ZnO / Al ₂ O ₃ , sodium, sodium-potassium alloys, cesium, magnesium, lithium, magnesium-silver alloys, aluminum, aluminum oxide, aluminum-lithium alloys, indium, rare earth metals, mixtures of these metals with organic luminescent media materials, and An organic electroluminescent element characterized by using an electrode material composed of a mixture of these metals and an electron injection layer material alone or by combining two or more kinds of these electrode materials The method of claim 1, The functional layer has an index of the refractive index of 0.1 to 10 and the thickness of the organic electroluminescent device, characterized in that it has a range of 1 nm to 1000 nm The method of claim 1, The functional layer may include an inorganic material of metal oxide or metal nitride; An organic material selected from a conductive organic material, a polymer compound, a mixture of a conductive organic compound and a polymer compound, a hole injection material, a hole transport material, an electron transport material, a host material, and a dopant material; any one or a combination thereof Organic electroluminescent element The method of claim 1, By controlling the thickness of the functional layer or the transparent upper electrode, the organic electroluminescent device, characterized in that to control the mutual reinforcement and interference of the light emitted in the organic electroluminescent device. The method of claim 1, The reflective layer is characterized in that the organic electroluminescent device, characterized in that the reflectance is 20% or more. The method of claim 1, The reflective layer is made of a component using one or more materials selected from aluminum, magnesium, silver, gold, platinum, chromium, cobalt, tungsten, calcium, lithium, sodium, or a combination of two or more of these materials. Organic EL device, characterized in that the thickness is in the range of 1 nm to 5000 nm. The method of claim 1, The organic thin film layer may include at least one layer selected from a hole injection layer, a hole transport layer, an electron blocking layer, a hole injection function, and a hole injection function, a light emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer. An organic electroluminescent device, characterized in that. The method of claim 11, At least one layer selected from a layer including a hole injection layer, a hole transport layer, an electron blocking layer, a hole injection function and a hole transport function, a light emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer included in the organic thin film layer Organic electroluminescent device, characterized in that the mutual reinforcement and interference control of light by changing the thickness The method of claim 11, An organic electroluminescent device, characterized in that the light emitting layer emits light by a combination of a host and a dopant The method of claim 13, The host is an organic electroluminescent device, characterized in that it comprises at least one anthracene derivative represented by the following [Formula 1A] [Formula 1A]

In [Formula 1A], X ₁ to X ₁₀ are the same as or different from each other, and each independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, substituted or unsubstituted Substituted cycloalkyl group having 3 to 30 carbon atoms, substituted or unsubstituted cycloalkenyl group having 5 to 30 carbon atoms, substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, Substituted or unsubstituted alkyl thioxy group having 1 to 30 carbon atoms, substituted or unsubstituted arylthioxy group having 5 to 30 carbon atoms, substituted or unsubstituted alkylamine group having 1 to 30 carbon atoms, substituted or unsubstituted carbon atoms 5 to 30 An arylamine group having 30, a substituted or unsubstituted aryl group having 5 to 50 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 50 carbon atoms having O, N or S as a hetero atom, substituted Is an unsubstituted silicone, substituted or unsubstituted boron group, substituted or unsubstituted silane group, carbonyl group, phosphoryl group, amino group, nitrile group, hydroxy group, nitro group, halogen group, amide group and ester group Any one selected from and adjacent groups to each other can form a condensed ring of aliphatic, aromatic, aliphatic hetero or aromatic hetero. The method of claim 13, The dopant comprises one or more compounds represented by the following [Formula 2] or [Formula 3], an organic electroluminescent device  [Formula 2] [Formula 3]

In [Formula 2] and [Formula 3], A is an aromatic ring group having no heteroatom, and is a substituted or unsubstituted aromatic ring group having 6 to 50 carbon atoms; Or an aromatic heterocyclic group having O, N or S as a hetero atom, a substituted or unsubstituted aromatic heterocyclic group having 2 to 50 carbon atoms, and when n is 2 or more, each of the amine groups bonded to A is the same as each other, or Can be different, In Formula [2], X ₁ and X ₂ are the same as or different from each other, and are each independently selected from a substituted or unsubstituted arylene group having 6 to 30 carbon atoms or a single bond; X ₁ and X ₂ may combine with each other; Y ₁ to Y ₂ are the same as or different from each other, and each independently substituted or unsubstituted aryl group having 6 to 24 carbon atoms, substituted or unsubstituted heteroaryl group having 2 to 24 carbon atoms, substituted or unsubstituted carbon atom 1 to An alkyl group of 24, a substituted or unsubstituted heteroalkyl group having 1 to 24 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 24 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 24 carbon atoms, a cyano group, a halogen group, a substitution Or unsubstituted aryloxy group having 6 to 24 carbon atoms, substituted or unsubstituted alkylsilyl group having 1 to 40 carbon atoms, substituted or unsubstituted arylsilyl group having 6 to 30 carbon atoms, germanium, phosphorus, boron, deuterium and hydrogen It is selected from the group consisting of, and can form a condensed ring of aliphatic, aromatic, aliphatic hetero or aromatic hetero group and adjacent to each other; The said l and m are the integers of 1-20, respectively, and n is an integer of 1-4. In Formula 3, C _y is a substituted or unsubstituted cycloalkyl having 3 to 8 carbon atoms, respectively; b is an integer from 1 to 4, and when b is 2 or more, each cycloalkane may be in fused form; In addition, the hydrogen substituted therein may be each substituted with deuterium or alkyl, and may be the same or different from each other, B Is a single bond or-[C (R₅) (R₆)]-, And p is an integer of 1 to 3, and when p is 2 or more, 2 or more R₅ And R₆Are the same or different from each other; R_One, R₂, R_3,R₅ And R₆Are each the same or different and independently of each other, hydrogen, deuterium, halogen atom, hydroxyl group, cyano group, nitro group, amino group, amidino group, hydrazine, hydrazone, carboxyl group or salt thereof, sulfonic acid group or salt thereof, phosphoric acid Or salts thereof, substituted or unsubstituted alkyl groups having 1 to 60 carbon atoms, substituted or unsubstituted alkenyl groups having 2 to 60 carbon atoms, substituted or unsubstituted alkynyl groups having 2 to 60 carbon atoms, substituted or unsubstituted carbon atoms 1 to 60 Alkoxy group of 60, substituted or unsubstituted alkylthio group having 1 to 60 carbon atoms, substituted or unsubstituted cycloalkyl group having 3 to 60 carbon atoms, substituted or unsubstituted aryl group having 6 to 60 carbon atoms, substituted or Unsubstituted aryloxy group having 5 to 60 carbon atoms, substituted or unsubstituted arylthio group having 5 to 60 carbon atoms, substituted or unsubstituted heteroaryl group having 2 to 60 carbon atoms, substituted or unsubstituted C1-C60 (alkyl) amino group, di (substituted or unsubstituted C1-C60 alkyl) amino group, or (substituted or unsubstituted C6-C60 aryl) amino group, di (substituted or unsubstituted Aryl) amino group having 6 to 60 carbon atoms, substituted or unsubstituted alkylsilyl group having 1 to 40 carbon atoms, substituted or unsubstituted arylsilyl group having 6 to 30 carbon atoms, and a is an integer of 1 to 4, when a is 2 or more, two or more R ₃ are the same as or different from each other, and when R ₃ is a plurality, each R ₃ may be in a fused form, and n is 1 to 4 Is an integer. The method of claim 1, The reflective layer or the functional layer is connected to the light transmissive upper electrode by an ohmic (Ohomic) contact to reduce the resistance value of the light transmissive upper electrode, an organic electroluminescent device, characterized in that The method of claim 1, The organic electroluminescent device further comprises a capping layer between the lower electrode layer and the substrate layer or by preventing total reflection of light on the outer surface of the substrate layer to increase the luminous efficiency of the organic light emitting material. The method of claim 1, The organic EL device includes a blue light emitting material, a green light emitting material, or a red light emitting material that emits light in a wavelength range of 380 nm to 800 nm. The blue light emitting material, the green light emitting material, or the red light emitting material is a fluorescent material or a phosphorescent material. Organic electroluminescent element, characterized in that Forming a lower electrode on the light transmissive substrate; Forming an organic thin film layer including a light emitting layer on the lower electrode; Forming a light transmissive upper electrode on the organic thin film layer; Forming a functional layer which mutually reinforces and interferes with light transmitted on the upper electrode; And Method of manufacturing an organic electroluminescent device comprising forming a reflective layer on the functional layer The method of claim 19, The thickness of the functional layer or the transmissive upper electrode is formed, thereby controlling the mutual reinforcement and interference of the light emitted from the organic EL device manufacturing method of an organic EL device characterized in that The method of claim 19, The organic thin film layer may include at least one layer selected from a functional layer having a hole injection layer, a hole transport layer, an electron blocking layer, a hole injection function, and a hole transport function, a light emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer. Method for producing an organic electroluminescent device comprising The method of claim 21, At least one layer selected from among a hole injection layer, a hole transport layer, an electron blocking layer, a hole injection function and a hole transport function included in the organic thin film layer, a light emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer By adjusting the thickness, the method of manufacturing an organic EL device, characterized in that mutual reinforcement and interference of light emitted in the organic EL device are controlled. The method of claim 19, The functional layer may be an inorganic material of metal oxide or metal nitride; An organic material selected from a conductive organic material, a high molecular compound, a mixture of a conductive organic compound and a high molecular compound, a hole injection material, a hole transport material, an electron transport material, a host material, and a material for a dopant; The manufacturing method of the organic electroluminescent element made into The method of claim 19 or 21, The lower electrode, the organic thin film layer, the hole injection layer, the hole transport layer, the electron blocking layer, a functional layer having a hole injection function and a hole transport function at the same time, a light emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer, a light transmissive upper electrode, At least one layer selected from the functional layer and the reflective layer is formed by a deposition process or a solution process, characterized in that the manufacturing method of the organic EL device The method according to any one of claims 1 to 18, The organic EL device may include a flat panel display device; Flexible display devices; Monochrome or white flat lighting devices; And an organic electroluminescent element, which is used in any one device selected from a single or white flexible lighting device.

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