KR102083093B1 - Organic light emitting device - Google Patents

Abstract

The present specification relates to an organic light emitting device.

Description

Organic light emitting element {ORGANIC LIGHT EMITTING DEVICE}

The present application relates to an organic light emitting device.

In general, organic light emitting phenomenon refers to a phenomenon of converting electrical energy into light energy using an organic material. An organic light emitting device using an organic light emitting phenomenon usually has a structure including an anode, a cathode and an organic material layer therebetween. In this case, the organic material layer is often made of a multi-layer structure composed of different materials in order to increase the efficiency and stability of the organic light emitting device, for example, it may be made of a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer. When the voltage is applied between the two electrodes in the structure of the organic light emitting device, holes are injected into the organic material layer at the anode, and electrons are injected into the organic material layer, and excitons are formed when the injected holes and the electrons meet each other. When it falls back to the ground, it glows.

In this process, in order to improve the efficiency characteristics of the OLED, a film is inserted between the light emitting layer and the electron transport layer with a material having a triplet higher than the triplet of the light emitting layer host. This helps to improve efficiency by using TTA, but excitons are mainly formed in the light emitting layer and adjacent to the blocking layer, causing only a part of the light emitting layer to be severely stressed, resulting in a shorter lifespan.

Therefore, there is a continuing need for development of a technology capable of improving the lifetime characteristics of the organic light emitting device and at the same time obtaining the conventional efficiency.

ACS Appl. Mater. Interfaces 2017, 9, 19040

The present application provides an organic light emitting device.

The present application is a first electrode; A second electrode provided to face the first electrode; And a light emitting layer, an exciton control layer, and an electron transport layer sequentially provided between the first electrode and the second electrode, wherein the light emitting layer includes a host and a dopant.

The triplet energy of the light emitting layer host is greater than or equal to the triplet energy of the exciton control layer to provide an organic light emitting device.

The organic light emitting device according to the exemplary embodiment of the present application is capable of low driving voltage, high luminous efficiency and / or long life.

1 shows an example of an organic light emitting device in which a substrate 1, an anode 2, a light emitting layer 3, and a cathode 4 are sequentially stacked.
2 shows an organic light emitting device in which a substrate 1, an anode 2, a hole injection layer 5, a light emitting layer 3, an exciton control layer 6, an electron transport layer 7 and a cathode 4 are sequentially stacked. An example is shown.
3 to 6 are graphs showing the life characteristics of the device according to the exemplary embodiment of the present application in comparison with a comparative example.

Hereinafter, this specification is demonstrated in detail.

In this specification, when a member is located "on" another member, this includes not only when one member is in contact with another member but also when another member exists between the two members.

In the present specification, when a part "includes" a certain component, this means that the component may further include other components, except for the case where there is no description to the contrary.

Herein is a first electrode; A second electrode provided to face the first electrode; And a light emitting layer, an exciton control layer, and an electron transport layer sequentially provided between the first electrode and the second electrode, wherein the light emitting layer includes a host and a dopant.

The triplet energy of the light emitting layer host is greater than or equal to the triplet energy of the exciton control layer.

In addition, the exemplary embodiment of the present specification provides an organic light emitting device in which the light emitting layer and the exciton control layer are in contact with each other, and the exciton control layer and the electron transport layer are in contact with each other.

In addition, according to an exemplary embodiment of the present specification, the triplet energy of the emission layer host and the triplet energy of the exciton control layer may be the same.

In addition, according to an exemplary embodiment of the present specification, the electron transport layer is made of a material having a triplet energy higher than the triplet energy of the exciton control layer.

The triplet energy of the electron transport layer is larger, so that the TTA (Triplet-Triplet Annihilation) occurs smoothly in the exciton control layer, and the singlet generated through the TTA is transferred to the singlet of the light emitting dopant, thereby improving efficiency. Because it can.

Conventionally, in order to prevent the triplet of the host from emitting light and disappearing, the triplet energy of the layer in contact with the light emitting layer is made of a material higher than the triplet energy of the light emitting layer host. The density of light emitting excitons (Exciton) in the vicinity of the contact layer is increased, the degradation is severe, thereby shortening the life of the entire device.

Therefore, according to an exemplary embodiment of the present specification, it is possible to extend the life of the device by mitigating the triplet and dividing the light emitting region by dividing the excessive excitation of the light excitons in a predetermined portion. In this case, the exciton control layer, which is a layer in contact with the light emitting layer, is made of a material having the same material as the light emitting layer host or a triplet energy such as the light emitting layer host, and the light emitting dopant is not included.

In addition, according to an exemplary embodiment of the present specification, triplet energy can be measured using a spectroscopic device capable of measuring fluorescence and phosphorescence, and in the case of the measurement conditions, toluene or TF with solvent in a cryogenic state using liquid nitrogen Prepare a solution at a concentration of 10 ^-6 M, and confirm by analyzing the emission spectrum in triplet from the emission spectrum by irradiating the light source with the absorption wavelength band of the material to the solution.

In addition, according to an exemplary embodiment of the present specification, the host and the exciton control layer of the light emitting layer includes a compound represented by the following formula (1).

[Formula 1]

In Formula 1, Ar1 and Ar2 are each independently a substituted or unsubstituted aryl group; Or a substituted or unsubstituted heterocyclic group, R1 to R8 are each independently hydrogen; heavy hydrogen; Halogen group; Nitro group; Cyano group; Ester group; Carbonyl group; Substituted or unsubstituted alkyl group; A substituted or unsubstituted cycloalkyl group; Substituted or unsubstituted alkoxy group; Substituted or unsubstituted alkenyl group; Substituted or unsubstituted aryl group; Or a substituted or unsubstituted heteroring group.

Examples of substituents herein are described below, but are not limited thereto.

The term "substituted" means that a hydrogen atom bonded to a carbon atom of the compound is replaced with another substituent, and the position to be substituted is not limited to a position where the hydrogen atom is substituted, that is, a position where a substituent can be substituted, if two or more substituted , Two or more substituents may be the same or different from each other.

As used herein, the term "substituted or unsubstituted" is hydrogen; Halogen group; Nitrile group; Nitro group; Hydroxyl group; Substituted or unsubstituted alkyl group; A substituted or unsubstituted cycloalkyl group; Substituted or unsubstituted alkenyl group; Substituted or unsubstituted amine group; Substituted or unsubstituted aryl group; And it is substituted with one or two or more substituents selected from the group consisting of a substituted or unsubstituted heterocyclic group, or two or more of the substituents exemplified above are substituted with a substituent, or means that do not have any substituents. For example, "a substituent to which two or more substituents are linked" may be a biphenyl group. That is, the biphenyl group may be an aryl group, and can be interpreted as a substituent to which two phenyl groups are linked.

In the present specification, examples of the halogen group include fluorine, chlorine, bromine or iodine.

In this specification, although carbon number of an ester group is not specifically limited, It is preferable that it is C1-C50. Specifically, it may be a compound of the following structural formula, but is not limited thereto.

Although carbon number of a carbonyl group in this specification is not specifically limited, It is preferable that it is C1-C50. Specifically, it may be a compound having a structure as follows, but is not limited thereto.

In the present specification, the alkyl group may be linear or branched chain, carbon number is not particularly limited, but is preferably 1 to 50. Specific examples include methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methyl-butyl, 1-ethyl-butyl, pentyl, n-pentyl , Isopentyl, neopentyl, tert-pentyl, hexyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, heptyl, n -Heptyl, 1-methylhexyl, cyclopentylmethyl, cyclohexylmethyl, octyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethyl Heptyl, 1-ethyl-propyl, 1,1-dimethyl-propyl, isohexyl, 2-methylpentyl, 4-methylhexyl, 5-methylhexyl, and the like.

In the present specification, the cycloalkyl group is not particularly limited, but preferably 3 to 60 carbon atoms, specifically, cyclopropyl, cyclobutyl, cyclopentyl, 3-methylcyclopentyl, 2,3-dimethylcyclopentyl, cyclohexyl, 3-methylcyclohexyl, 4-methylcyclohexyl, 2,3-dimethylcyclohexyl, 3,4,5-trimethylcyclohexyl, 4-tert-butylcyclohexyl, cycloheptyl, cyclooctyl, and the like, but are not limited thereto. Do not.

In the present specification, the alkoxy group may be linear, branched or cyclic. Although carbon number of an alkoxy group is not specifically limited, It is preferable that it is C1-C20. Specifically, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy, sec-butoxy, n-pentyloxy, neopentyloxy, isopentyloxy, n -Hexyloxy, 3,3-dimethylbutyloxy, 2-ethylbutyloxy, n-octyloxy, n-nonyloxy, n-decyloxy, benzyloxy, p-methylbenzyloxy, and the like, but It is not limited.

In the present specification, the alkenyl group may be linear or branched chain, carbon number is not particularly limited, but is preferably 2 to 40. Specific examples include vinyl, 1-propenyl, isopropenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 3-methyl-1- Butenyl, 1,3-butadienyl, allyl, 1-phenylvinyl-1-yl, 2-phenylvinyl-1-yl, 2,2-diphenylvinyl-1-yl, 2-phenyl-2- ( Naphthyl-1-yl) vinyl-1-yl, 2,2-bis (diphenyl-1-yl) vinyl-1-yl, stilbenyl group, styrenyl group and the like, but are not limited thereto.

In the present specification, when the aryl group is a monocyclic aryl group, carbon number is not particularly limited, but preferably 6 to 25 carbon atoms. Specifically, the monocyclic aryl group may be a phenyl group, a biphenyl group, a terphenyl group, etc., but is not limited thereto.

Carbon number is not particularly limited when the aryl group is a polycyclic aryl group. It is preferable that it is C10-24. Specifically, the polycyclic aryl group may be a naphthyl group, anthracenyl group, phenanthryl group, pyrenyl group, peryllenyl group, chrysenyl group, fluorenyl group, and the like, but is not limited thereto.

In the present specification, the fluorenyl group may be substituted, and adjacent substituents may combine with each other to form a ring.

,

,

및

등이 될 수 있으나, 이에 한정되는 것은 아니다.When the fluorenyl group is substituted,

,

,

And

Etc., but is not limited thereto.

In the present specification, the heterocyclic group includes one or more atoms other than carbon and heteroatoms, and specifically, the heteroatoms may include one or more atoms selected from the group consisting of O, N, Se, and S, and the like. Although carbon number of a heterocyclic group is not specifically limited, It is preferable that it is C2-C60. Examples of the heterocyclic group include thiophene group, furan group, pyrrole group, imidazole group, thiazole group, oxazole group, oxadiazole group, triazole group, pyridyl group, bipyridyl group, pyrimidyl group, triazine group, triazole group, Acridil group, pyridazine group, pyrazinyl group, quinolinyl group, quinazoline group, quinoxalinyl group, phthalazinyl group, pyrido pyrimidinyl group, pyrido pyrazinyl group, pyrazino pyrazinyl group, isoquinoline group , Indole group, carbazole group, benzoxazole group, benzimidazole group, benzothiazole group, benzocarbazole group, benzothiophene group, dibenzothiophene group, benzofuranyl group, phenanthroline group, phenanthroline group, thiazolyl group, Isooxazolyl group, oxadiazolyl group, thiadiazolyl group, benzothiazolyl group, phenothiazinyl group, dibenzofuranyl group, and the like, but is not limited thereto.

In the present specification, the term "adjacent" means a substituent substituted on an atom directly connected to the atom to which the corresponding substituent is substituted, a substituent positioned closest to the substituent, or another substituent substituted on the atom to which the substituent is substituted. Can be. For example, two substituents substituted at the ortho position in the benzene ring and two substituents substituted at the same carbon in the aliphatic ring may be interpreted as "adjacent" groups.

In the present specification, the meaning that adjacent groups are bonded to each other to form a ring means that adjacent groups are bonded to each other as described above to form a 5 to 8 membered hydrocarbon ring or a 5 to 8 membered hetero ring. , Monocyclic or polycyclic, and may be aliphatic, aromatic or condensed form thereof, but is not limited thereto.

According to an exemplary embodiment of the present application, the compound represented by Formula 1 is represented by any one selected from the following structural formula.

In addition, according to one embodiment of the present specification, the dopant may use an amine-based material. More specifically, a substance containing pyrene or dibenzofuran may be used.

According to an exemplary embodiment of the present specification, the dopant includes a compound represented by the following formula (2).

[Formula 2]

In Chemical Formula 2,

X is a direct bond or CR ',

R 'and R11 to R19 are each independently hydrogen; heavy hydrogen; Halogen group; Substituted or unsubstituted alkyl group; A substituted or unsubstituted cycloalkyl group; Substituted or unsubstituted amine group; Substituted or unsubstituted aryl group; Substituted or unsubstituted arylamine group; Or a substituted or unsubstituted heterocyclic group, and groups adjacent to each other may combine to form a ring,

At least two of R11 to R19 are represented by the following formula (3),

[Formula 3]

In Chemical Formula 3,

R20 and R21 are each independently hydrogen; heavy hydrogen; Halogen group; Substituted or unsubstituted alkyl group; A substituted or unsubstituted cycloalkyl group; Substituted or unsubstituted amine group; Substituted or unsubstituted aryl group; Substituted or unsubstituted arylamine group; Or a substituted or unsubstituted heteroring group.

In addition, according to an exemplary embodiment of the present specification, any one of R11 to R13 and any one of R16 to R18 is represented by the formula (3).

In addition, according to an exemplary embodiment of the present specification, R11 and R16 are represented by the formula (3).

In addition, according to an exemplary embodiment of the present specification, R12 and R17 are represented by the formula (3).

In addition, according to an exemplary embodiment of the present specification, R13 and R18 are represented by the formula (3).

According to an exemplary embodiment of the present specification, the dopant includes any one selected from the following compounds.

According to an exemplary embodiment of the present specification, the thickness of the exciton control layer is 10 to 150Å. If the thickness is thinner than 10Å can not play a role of the exciton control, if it is thicker than 150Å may interfere with the flow of electrons may be less efficient. More specifically, it is 10-100 microseconds, More specifically, it is 10-50 microseconds.

According to one embodiment of the present specification, the exciton control layer may use a host that does not include a dopant used in the emission layer.

The light emitting layer of the organic light emitting device of the present specification may be included in the organic material layer, and the organic material layer may be formed of a single layer structure, but may be formed of a multilayer structure in which two or more organic material layers are stacked. For example, the organic light emitting device of the present invention may have a structure including a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer and the like as an organic material layer. However, the structure of the organic light emitting device is not limited thereto and may include a smaller number of organic layers.

In an exemplary embodiment of the present specification, the organic light emitting device may be an organic light emitting device having a structure in which an anode, one or more organic material layers, and a cathode are sequentially stacked on a substrate.

 In another exemplary embodiment, the organic light emitting device may be an organic light emitting device having an inverted type in which a cathode, one or more organic material layers, and an anode are sequentially stacked on a substrate.

For example, the structure of an organic light emitting diode according to one embodiment of the present specification is illustrated in FIGS. 1 and 2.

1 illustrates a structure of an organic light emitting device in which a substrate 1, an anode 2, a light emitting layer 3, and a cathode 4 are sequentially stacked.

2 illustrates an organic light emitting device in which a substrate 1, an anode 2, a hole injection layer 5, a light emitting layer 3, an exciton control layer 6, an electron transport layer 7 and a cathode 4 are sequentially stacked. The structure of is illustrated. As shown in FIG. 2, the organic light emitting device according to the exemplary embodiment of the present specification may provide an exciton control layer between the light emitting layer and the electron transport layer.

The organic light emitting device of the present specification may be manufactured by materials and methods known in the art, except for including the exciton control layer herein.

For example, the organic light emitting device of the present specification may be manufactured by sequentially stacking a first electrode, an organic material layer, and a second electrode on a substrate. At this time, by using a physical vapor deposition (PVD) method such as sputtering or e-beam evaporation, a metal or conductive metal oxide or an alloy thereof is deposited on the substrate to form an anode. And an organic material layer including a hole injection layer, a hole transporting layer, a light emitting layer, and an electron transporting layer thereon, and then depositing a material that can be used as a cathode thereon. In addition to the above method, an organic light emitting device may be manufactured by sequentially depositing a cathode material, an organic material layer, and an anode material on a substrate.

In addition, the exciton control layer may be formed of an organic material layer by a solution coating method as well as a vacuum deposition method in the manufacture of the organic light emitting device. Here, the solution coating method means spin coating, dip coating, doctor blading, inkjet printing, screen printing, spray method, roll coating, etc., but is not limited thereto.

In addition to such a method, an organic light emitting device may be fabricated by sequentially depositing an organic material layer and an anode material on a substrate (International Patent Application Publication No. 2003/012890). However, the manufacturing method is not limited thereto.

In one embodiment of the present specification, the first electrode is an anode, and the second electrode is a cathode.

In another exemplary embodiment, the first electrode is a cathode and the second electrode is an anode.

As the anode material, a material having a large work function is generally preferred to facilitate hole injection into the organic material layer. Specific examples of the positive electrode material that can be used in the present invention include metals such as vanadium, chromium, copper, zinc and gold or alloys thereof; Metal oxides such as zinc oxide, indium oxide, indium tin oxide (ITO), indium zinc oxide (IZO); ZnO: Al or SNO 2: Combination of oxides with metals such as Sb; Conductive polymers such as poly (3-methylthiophene), poly [3,4- (ethylene-1,2-dioxy) thiophene] (PEDOT), polypyrrole and polyaniline, and the like, but are not limited thereto.

It is preferable that the cathode material is a material having a small work function to facilitate electron injection into the organic material layer. Specific examples of the negative electrode material include metals such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, and lead or alloys thereof; Multilayer structure materials such as LiF / Al or LiO 2 / Al, and the like, but are not limited thereto.

The hole injection material is a layer for injecting holes from an electrode, and the hole injection material has a capability of transporting holes. The hole injection material has a hole injection effect at an anode, and has an excellent hole injection effect for a light emitting layer or a light emitting material. The compound which prevents the movement of the excited excitons to the electron injection layer or the electron injection material, and is excellent in thin film formation ability is preferable. Preferably, the highest occupied molecular orbital (HOMO) of the hole injection material is between the work function of the positive electrode material and the HOMO of the surrounding organic material layer. Specific examples of the hole injection material include metal porphyrin, oligothiophene, arylamine-based organic material, hexanitrile hexaazatriphenylene-based organic material, quinacridone-based organic material, and perylene-based Organic materials, anthraquinone and polyaniline and polythiophene-based conductive polymers, but are not limited thereto.

The hole transport layer is a layer that receives holes from the hole injection layer and transports holes to the light emitting layer. The hole transport material is a material capable of transporting holes from the anode or the hole injection layer to the light emitting layer. The material is suitable. Specific examples thereof include an arylamine-based organic material, a conductive polymer, and a block copolymer having a conjugated portion and a non-conjugated portion together, but are not limited thereto.

The light emitting material is a material capable of emitting light in the visible region by transporting and combining holes and electrons from the hole transport layer and the electron transport layer, respectively, and a material having good quantum efficiency with respect to fluorescence or phosphorescence is preferable. Specific examples include 8-hydroxyquinoline aluminum complex (Alq 3); Carbazole series compounds; Dimerized styryl compounds; BAlq; 10-hydroxybenzo quinoline-metal compound; Benzoxazole, benzthiazole and benzimidazole series compounds; Poly (p-phenylenevinylene) (PPV) -based polymers; Spiro compounds; Polyfluorene, rubrene and the like, but are not limited thereto.

The light emitting layer may include a host material and a dopant material. The host material may be a condensed aromatic ring derivative or a hetero ring-containing compound. Specifically, the condensed aromatic ring derivatives include anthracene derivatives, pyrene derivatives, naphthalene derivatives, pentacene derivatives, phenanthrene compounds, and fluoranthene compounds, and the heterocyclic containing compounds include compounds, dibenzofuran derivatives and ladder type furan compounds. , Pyrimidine derivatives, and the like, but is not limited thereto.

The electron transporting material is a layer that receives electrons from the electron injection layer and transports electrons to the light emitting layer. The electron transporting material is a material that can inject electrons well from the cathode and transfer them to the light emitting layer. This is suitable. Specific examples thereof include Al complexes of 8-hydroxyquinoline; Complexes including Alq3; Organic radical compounds; Hydroxyflavone-metal complexes and the like, but are not limited thereto. The electron transport layer can be used with any desired cathode material as used according to the prior art. In particular, examples of suitable cathode materials are conventional materials having a low work function followed by an aluminum or silver layer. Specifically cesium, barium, calcium, ytterbium and samarium, followed by aluminum layers or silver layers in each case.

The electron injection layer is a layer that injects electrons from an electrode, has an ability of transporting electrons, has an electron injection effect from a cathode, an excellent electron injection effect on a light emitting layer or a light emitting material, and hole injection of excitons generated in the light emitting layer The compound which prevents the movement to a layer and is excellent in thin film formation ability is preferable. Specifically, fluorenone, anthraquinodimethane, diphenoquinone, thiopyran dioxide, oxazole, oxadiazole, triazole, imidazole, perylenetetracarboxylic acid, preorenylidene methane, anthrone and the derivatives thereof, metal Complex compounds, nitrogen-containing five-membered ring derivatives, and the like, but are not limited thereto.

Examples of the metal complex compound include 8-hydroxyquinolinato lithium, bis (8-hydroxyquinolinato) zinc, bis (8-hydroxyquinolinato) copper, bis (8-hydroxyquinolinato) manganese, Tris (8-hydroxyquinolinato) aluminum, tris (2-methyl-8-hydroxyquinolinato) aluminum, tris (8-hydroxyquinolinato) gallium, bis (10-hydroxybenzo [h] Quinolinato) beryllium, bis (10-hydroxybenzo [h] quinolinato) zinc, bis (2-methyl-8-quinolinato) chlorogallium, bis (2-methyl-8-quinolinato) ( o-cresolato) gallium, bis (2-methyl-8-quinolinato) (1-naphtholato) aluminum, bis (2-methyl-8-quinolinato) (2-naphtolato) gallium, etc. It is not limited to this.

The hole blocking layer is a layer that blocks the reaching of the cathode of the hole, and may be generally formed under the same conditions as the hole injection layer. Specifically, there are oxadiazole derivatives, triazole derivatives, phenanthroline derivatives, BCP, aluminum complexes, and the like, but are not limited thereto.

The organic light emitting device according to the present specification may be a top emission type, a bottom emission type, or a double-sided emission type according to a material used.

Hereinafter, the present invention will be described in detail with reference to Examples. However, embodiments according to the present disclosure may be modified in various other forms, and the scope of the present specification is not interpreted to be limited to the embodiments described below. The embodiments of the present specification are provided to more fully describe the present specification to those skilled in the art.

Production Example  One

Production Example  2

In Preparation Example 1, 1-bromo-4-nitrobenzene instead of [1], naphthalen-1-ylbronic acid instead of [2], and (10- (naphthalen-2-yl) anthracene-9- instead of [6] The same procedure was followed to prepare BH-2 except for using one) boronic acid.

Production Example  3

Production Example  4

Production Example  5

Production Example  6

Production Example  7

Production Example  8

Production Example  8

Production Example  9

Experimental Example

The light emitting area of the ITO glass was patterned to have a size of 2 mm x 2 mm and then washed. After mounting the ITO glass in a vacuum chamber, the base pressure was 1 × 10 ⁻⁷ torr, and then on the ITO, the following HIL (50 kPa), HTL-1 (800 kPa), and HTL-2 (100 kPa) were used. After the film formation, the BH-1 was deposited at a rate of 2.0 mW / s as a host of the light emitting layer, and the following BD-1, a light emitting dopant, was deposited together at a rate of 0.06 mW / s to form a 200 mW light emitting layer. Thereafter, the following ET-1 was formed into a film having a thickness of 50 GPa as the exciton adjusting layer, and the following ET-2 was formed into a film having a thickness of 250 GPa. Subsequently, after forming 10 F of LiF with the following EIL, aluminum was deposited at 1000 으로 with a cathode to fabricate the device of Comparative Example 1.

The device was encapsulated with a stainless cover under N2 atmosphere, and the voltage, brightness, and efficiency were measured at a current density of 10mA / cm2, and the same device measured the time when the luminance reduction reached 90% at a constant current of 10mA / cm2.

The rest of the devices using the same type of substrate, HIL, HTL-1 and HTL-2, LiF, Al are the same as in Comparative Example 1 and the structure and thickness of the light emitting layer, the exciton control layer and the electron transport layer are shown in Tables 1 to 3 below. It was made according to the contents.

Experiment# Light emitting layer
(Triplet) BD Exciton control layer
(Triplet) Thickness of exciton control layer
(Å) ETL
(Triplet) Vop mA / cm2 Cd / A Life-time
(@ 90%) Comparative Example 1 BH-1 (1.6eV) BD-1 ET-1 (2.4eV) 50 ET-2 (1.6eV) 3.79 10 6.8 58 Comparative Example 2 BH-1 (1.6eV) BD-1 ET-1 (2.4eV) 50 ET-3 (1.5eV) 3.51 10 6.3 64 Comparative Example 3 BH-2 (1.6eV) BD-2 ET-1 (2.4eV) 50 ET-2 (1.6eV) 3.75 10 6.7 55 Comparative Example 4 BH-2 (1.6eV) BD-2 ET-1 (2.4eV) 50 ET-3 (1.5eV) 3.56 10 6.1 59 Comparative Example 5 BH-3 (1.6eV) BD-2 ET-1 (2.4eV) 50 ET-2 (1.6eV) 3.77 10 7.2 60 Comparative Example 6 BH-3 (1.6eV) BD-2 ET-1 (2.4eV) 50 ET-3 (1.5eV) 3.50 10 6.9 68 Comparative Example 7 BH-4 (1.7 eV) BD-2 ET-2 (1.6eV) 50 ET-1 (2.4eV) 4.90 10 5.3 87 Example 1 BH-1 (1.6eV) BD-1 BH-1 (1.6eV) 50 ET-1 (2.4eV) 3.45 10 8.7 107 Example 2 BH-1 (1.6eV) BD-1 BH-1 (1.6eV) 50 ET-2 (1.6eV) 3.33 10 6.7 103 Example 3 BH-1 (1.6eV) BD-1 BH-1 (1.6eV) 50 ET-3 (1.5eV) 3.31 10 6.1 98 Example 4 BH-1 (1.6eV) BD-1 BH-1 (1.6eV) 30 ET-3 (1.5eV) 3.20 10 6.0 95 Example 5 BH-1 (1.6eV) BD-1 BH-1 (1.6eV) 10 ET-3 (1.5eV) 3.12 10 5.2 88 Example 6 BH-1 (1.6eV) BD-1 ET-2 (1.6eV) 50 ET-1 (2.4eV) 3.43 10 8.3 100 Example 7 BH-1 (1.6eV) BD-1 ET-2 (1.6eV) 50 ET-2 (1.6eV) 3.32 10 6.8 99 Example 8 BH-1 (1.6eV) BD-1 ET-2 (1.6eV) 50 ET-3 (1.5eV) 3.31 10 6.2 97

Experiment# Light emitting layer
(Triplet) BD Exciton control layer
(Triplet) Thickness of exciton control layer
(Å) ETL
(Triplet) Vop mA / cm2 Cd / A Life-time
(@ 90%) Example 9 BH-2 (1.6eV) BD-2 BH-2 (1.6eV) 50 ET-1 (2.4eV) 3.43 10 8.9 127 Example 10 BH-2 (1.6eV) BD-2 BH-2 (1.6eV) 50 ET-2 (1.6eV) 3.30 10 7.1 113 Example 11 BH-2 (1.6eV) BD-2 BH-2 (1.6eV) 50 ET-3 (1.5eV) 3.31 10 7.1 122 Example 12 BH-2 (1.6eV) BD-2 ET-2 (1.6eV) 50 ET-1 (2.4eV) 3.39 10 8.3 123 Example 13 BH-2 (1.6eV) BD-2 ET-2 (1.6eV) 50 ET-2 (1.6eV) 3.20 10 6.8 109 Example 14 BH-2 (1.6eV) BD-2 ET-2 (1.6eV) 50 ET-3 (1.5eV) 3.28 10 6.5 111 Example 15 BH-3 (1.6eV) BD-2 BH-3 (1.6eV) 50 ET-1 (2.4eV) 3.48 10 8.7 123 Example 16 BH-3 (1.6eV) BD-2 BH-3 (1.6eV) 50 ET-2 (1.6eV) 3.17 10 8.4 131 Example 17 BH-3 (1.6eV) BD-2 BH-3 (1.6eV) 50 ET-3 (1.5eV) 3.20 10 8.3 138 Example 18 BH-3 (1.6eV) BD-2 ET-2 (1.6eV) 50 ET-1 (2.4eV) 3.42 10 7.9 142 Example 19 BH-3 (1.6eV) BD-2 ET-2 (1.6eV) 50 ET-2 (1.6eV) 3.17 10 7.7 137 Example 20 BH-3 (1.6eV) BD-2 ET-2 (1.6eV) 50 ET-3 (1.5eV) 3.16 10 7.7 135 Example 21 BH-1 (1.6eV) BD-1 BH-1 (1.6eV) 150 ET-1 (2.4eV) 3.55 10 7.7 122 Example 22 BH-2 (1.6eV) BD-2 BH-2 (1.6eV) 150 ET-1 (2.4eV) 3.54 10 7.5 133 Example 23 BH-3 (1.6eV) BD-2 BH-3 (1.6eV) 150 ET-1 (2.4eV) 3.50 10 7.4 132

Experiment# Light emitting layer
(Triplet) BD Exciton control layer
(Triplet) Thickness of exciton control layer
(Å) ETL
(Triplet) Vop mA / cm2 Cd / A Life-time
(@ 90%) Example 24 BH-4 (1.7 eV) BD-2 BH-4 (1.7 eV) 50 ET-1 (2.4eV) 4.23 10 4.3 213 Example 25 BH-4 (1.7 eV) BD-2 BH-4 (1.7 eV) 50 ET-2 (1.6eV) 4.30 10 4.1 244 Example 26 BH-4 (1.7 eV) BD-2 BH-4 (1.7 eV) 50 ET-3 (1.5eV) 4.35 10 4.0 247

Referring to Tables 1 to 3, it can be seen that the device having the same triplet energy of the light emitting layer and the exciton control layer according to the exemplary embodiment of the present specification has a higher lifespan characteristic than the device that does not have the same triplet energy.

In addition, it can be seen that when the emission layer and the exciton control layer have the same triplet energy, when the triplet energy of the electron transport layer is higher than that of the emission layer and the exciton control layer, the Cd / A value is higher and the efficiency is increased. For example, in Examples 1 to 3, in Example 1, the triplet energy value of the electron transport layer is greater than the triplet energy value of the exciton control layer, and the efficiency of Example 1 is greater than that of Examples 2 and 3. .

3 and 4 are graphs showing life characteristics over time by selecting some of the comparative examples and examples. As can be seen from Figure 3 to Figure 6, compared with the comparative example it can be seen that the efficiency decrease rate is slow over time, compared to the comparative example, it can be seen that the life characteristics are excellent.

1: substrate
2: anode
3: light emitting layer
4: cathode
5: hole injection layer
6: exciton adjusting layer
7: electron transport layer

Claims (7)

A first electrode;
A second electrode provided to face the first electrode; And
It includes a light emitting layer, an exciton control layer and an electron transport layer sequentially provided between the first electrode and the second electrode,
The light emitting layer includes a host and a dopant,
The light emitting layer and the exciton control layer is in contact with each other,
The exciton control layer and the electron transport layer are in contact with each other,
The electron transport layer is made of a material having a triplet energy higher than the triplet energy of the exciton control layer,
The triplet energy of the light emitting layer host is the same as the triplet energy of the exciton control layer, the exciton control layer is composed of the same material as the light emitting layer host. delete The method according to claim 1,
The dopant is an organic light emitting device comprising a compound represented by the following formula (2):
[Formula 2]

In Chemical Formula 2,
X is a direct bond or CR ',
R 'and R11 to R19 are each independently hydrogen; heavy hydrogen; Halogen group; An alkyl group having 1 to 20 carbon atoms which is unsubstituted or substituted with one group or two or more connected groups from the group consisting of an alkyl group having 1 to 20 carbon atoms and an aryl group having 6 to 30 carbon atoms; A cycloalkyl group having 3 to 30 carbon atoms which is unsubstituted or substituted with one group or two or more connected groups in the group consisting of an alkyl group having 1 to 20 carbon atoms and an aryl group having 6 to 30 carbon atoms; An amine group unsubstituted or substituted with one group or two or more linked groups in the group consisting of an alkyl group having 1 to 20 carbon atoms and an aryl group having 6 to 30 carbon atoms; An aryl group having 6 to 30 carbon atoms unsubstituted or substituted with one group or two or more connected groups from a group consisting of an alkyl group having 1 to 20 carbon atoms and an aryl group having 6 to 30 carbon atoms; An arylamine group having 6 to 30 carbon atoms which is unsubstituted or substituted with one group or two or more linked groups from the group consisting of an alkyl group having 1 to 20 carbon atoms and an aryl group having 6 to 30 carbon atoms; Or an N, O or S-containing heterocyclic group having 2 to 30 carbon atoms substituted or unsubstituted with one or two or more linked groups from the group consisting of an alkyl group having 1 to 20 carbon atoms and an aryl group having 6 to 30 carbon atoms, Adjacent groups may be joined to form an aromatic hydrocarbon ring of 6 to 30 carbon atoms or a heterocyclic ring containing N, O or S of 2 to 30 carbon atoms,
At least two of R11 to R19 are represented by the following formula (3),
[Formula 3]

In Chemical Formula 3,
R20 and R21 are each independently hydrogen; heavy hydrogen; Halogen group; C1-C20 unsubstituted or substituted with one group or two or more connected groups in the group consisting of an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, and an N, O or S-containing heterocyclic group having 2 to 30 carbon atoms 20 alkyl groups; 3 to 3 carbon atoms unsubstituted or substituted with one group or two or more linked groups in the group consisting of an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, and an N, O or S containing heterocyclic group having 2 to 30 carbon atoms. 30 cycloalkyl group; An amine group unsubstituted or substituted with one group or two or more linked groups in the group consisting of an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, and an N, O or S containing heterocyclic group having 2 to 30 carbon atoms; 6 to 6 carbon atoms unsubstituted or substituted with one group or two or more linked groups in the group consisting of an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, and an N, O or S containing heterocyclic group having 2 to 30 carbon atoms. An aryl group of 30; 6 to 6 carbon atoms unsubstituted or substituted with one group or two or more linked groups in the group consisting of an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, and an N, O or S containing heterocyclic group having 2 to 30 carbon atoms. 30 arylamine group; Or carbon atoms unsubstituted or substituted with one group or two or more linked groups in the group consisting of an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, and an N, O or S containing heterocyclic group having 2 to 30 carbon atoms. To N, O or S containing heterocyclic group. The method according to claim 3,
Any one of R11 to R13 and any one of R16 to R18 is represented by the formula (3). delete delete The method according to claim 1,
The thickness of the exciton control layer is an organic light emitting device of 10 to 150Å.

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