Patent Application
20240298532
The present disclosure relates to a novel compound and an organic light emitting device comprising the same.
In general, an organic light emitting phenomenon refers to a phenomenon where electric energy is converted into light energy by using an organic material. The organic light emitting device using the organic light emitting phenomenon has characteristics such as a wide viewing angle, an excellent contrast, a fast response time, an excellent luminance, driving voltage and response speed, and thus many studies have proceeded.
The organic light emitting device generally has a structure which comprises an anode, a cathode, and an organic material layer interposed between the anode and the cathode. The organic material layer frequently has a multilayered structure that comprises different materials in order to enhance efficiency and stability of the organic light emitting device, and for example, the organic material layer can be formed of a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and the like. In the structure of the organic light emitting device, if a voltage is applied between two electrodes, the holes are injected from an anode into the organic material layer and the electrons are injected from the cathode into the organic material layer, and when the injected holes and electrons meet each other, an exciton is formed, and light is emitted when the exciton falls to a ground state again.
There is a continuous need to develop a new material for the organic material used in the organic light emitting device as described above.
Patent Literature
It is an object of the present disclosure to provide a novel compound and an organic light emitting device comprising the same.
According to an aspect of the present disclosure, provided is a compound of Chemical Formula 1:
According to another aspect of the present disclosure, provided is an organic light emitting device comprising: a first electrode; a second electrode that is opposite to the first electrode; and one or more organic material layers that are between the first electrode and the second electrode, wherein one or more layers of the one or more organic material layers comprises the compound of Chemical Formula 1.
The above-mentioned compound of Chemical Formula 1 can be used as a material of an organic material layer in an organic light emitting device, and can improve the efficiency, achieve low driving voltage and/or improve lifetime characteristics in the organic light emitting device. In particular, the compound of Chemical Formula 1 can be used as hole injection, hole transport, light emission, electron transport, and/or electron injection materials.
Hereinafter, embodiments of the present disclosure will be described in more detail to facilitate understanding of the invention.
According to the present disclosure, the compound of Chemical Formula 1 is provided.
As used herein, the notation
and mean a bond linked to another substituent group.
As used herein, the term “substituted or unsubstituted” means being unsubstituted or substituted with one or more substituents selected from the group consisting of deuterium; a halogen group; a nitryl group; a nitro group; a hydroxy group; a carbonyl group; an ester group; an imide group; an amino group; a phosphine oxide group; an alkoxy group; an aryloxy group; an alkylthioxy group; an arylthioxy group; an alkylsulfoxy group; an arylsulfoxy group; a silyl group; a boron group; an alkyl group; a cycloalkyl group; an alkenyl group; an aryl group; an aralkyl group; an aralkenyl group; an alkylaryl group; an alkylamine group; an aralkylamine group; a heteroarylamine group; an arylamine group; an arylphosphine group; or a heteroaryl containing at least one of N, O and S atoms, or being unsubstituted or substituted with a substituent in which two or more substituents of the above-exemplified substituents are linked. For example, “a substituent in which two or more substituents are linked” can be a biphenyl group. Namely, a biphenylyl group can be an aryl group, or it can also be interpreted as a substituent in which two phenyl groups are linked.
In the present disclosure, the carbon number of a carbonyl group is not particularly limited, but is preferably 1 to 40. Specifically, it can be a substituent group having the following structure, but is not limited thereto:
In the present disclosure, an ester group can have a structure in which oxygen of the ester group can be substituted by a straight-chain, branched-chain, or cyclic alkyl group having 1 to 25 carbon atoms, or an aryl group having 6 to 25 carbon atoms. Specifically, it can be a substituent group having the following structure, but is not limited thereto:
In the present disclosure, the carbon number of an imide group is not particularly limited, but is preferably 1 to 25. Specifically, it can be a substituent group having the following structure, but is not limited thereto:
In the present disclosure, a silyl group specifically includes a trimethylsilyl group, a triethylsilyl group, a t-butyldimethylsilyl group, a vinyldimethylsilyl group, a propyldimethylsilyl group, a triphenylsilyl group, a diphenylsilyl group, a phenylsilyl group, and the like, but is not limited thereto.
In the present disclosure, a boron group specifically includes a trimethylboron group, a triethylboron group, a t-butyldimethylboron group, a triphenylboron group, and a phenylboron group, but is not limited thereto.
In the present disclosure, examples of a halogen group include fluorine, chlorine, bromine, or iodine.
In the present disclosure, the alkyl group can be straight-chain or branched-chain, and the carbon number thereof is not particularly limited, but is preferably 1 to 40. According to one embodiment, the carbon number of the alkyl group is 1 to 20. According to another embodiment, the carbon number of the alkyl group is 1 to 10. According to yet another embodiment, the carbon number of the alkyl group is 1 to 6. Specific examples of the alkyl group include methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methyl-butyl, 1-ethylbutyl, 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-dimethylheptyl, 1-ethyl-propyl, 1,1-dimethyl-propyl, isohexyl, 2-methylpentyl, 4-methylhexyl, 5-methylhexyl, and the like, but are not limited thereto.
In the present disclosure, the alkenyl group can be straight-chain or branched-chain, and the carbon number thereof is not particularly limited, but is preferably 2 to 40. According to one embodiment, the carbon number of the alkenyl group is 2 to 20. According to another embodiment, the carbon number of the alkenyl group is 2 to 10. According to still another embodiment, the carbon number of the alkenyl group is 2 to 6. Specific examples thereof 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, a stilbenyl group, a styrenyl group, and the like, but are not limited thereto.
In the present disclosure, a cycloalkyl group is not particularly limited, but the carbon number thereof is preferably 3 to 60. According to one embodiment, the carbon number of the cycloalkyl group is 3 to 30. According to another embodiment, the carbon number of the cycloalkyl group is 3 to 20. According to still another embodiment, the carbon number of the cycloalkyl group is 3 to 6. Specific examples thereof include 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.
In the present disclosure, an aryl group is not particularly limited, but the carbon number thereof is preferably 6 to 60, and it can be a monocyclic aryl group or a polycyclic aryl group. According to one embodiment, the carbon number of the aryl group is 6 to 30. According to one embodiment, the carbon number of the aryl group is 6 to 20. The aryl group can be a phenyl group, a biphenyl group, a terphenyl group or the like as the monocyclic aryl group, but is not limited thereto. The polycyclic aryl group includes a naphthyl group, an anthracenyl group, a phenanthryl group, a pyrenyl group, a perylenyl group, a chrysenyl group, a fluorenyl group, and the like, but is not limited thereto.
In the present disclosure, the fluorenyl group can be substituted, and two substituent groups can be linked with each other to form a spiro structure. In the case where the fluorenyl group is substituted,
the like can be formed. However, the structure is not limited thereto.
In the present disclosure, a heteroaryl group is a heteroaryl group containing one or more of O, N, Si and S as a heteroatom, and the carbon number thereof is not particularly limited, but is preferably 2 to 60. According to one embodiment, the carbon number of the heteroaryl group is 6 to 30. According to one embodiment, the carbon number of the heteroaryl group is 6 to 20. Examples of the heteroaryl group include a thiophene group, a furan group, a pyrrole group, an imidazole group, a thiazole group, an oxazol group, an oxadiazol group, a triazol group, a pyridyl group, a bipyridyl group, a pyrimidyl group, a triazine group, an acridyl group, a pyridazine group, a pyrazinyl group, a quinolinyl group, a quinazoline group, a quinoxalinyl group, a phthalazinyl group, a pyridopyrimidinyl group, a pyridopyrazinyl group, a pyrazinopyrazinyl group, an isoquinoline group, an indole group, a carbazole group, a benzoxazole group, a benzoimidazole group, a benzothiazol group, a benzocarbazole group, a benzothiophene group, a dibenzothiophene group, a benzofuranyl group, a phenanthroline group, an isoxazolyl group, a thiadiazolyl group, a phenothiazinyl group, a dibenzofuranyl group, and the like, but are not limited thereto.
In the present disclosure, the aryl group in the aralkyl group, the aralkenyl group, the alkylaryl group and the arylamine group is the same as the aforementioned examples of the aryl group. In the present disclosure, the alkyl group in the aralkyl group, the alkylaryl group and the alkylamine group is the same as the aforementioned examples of the alkyl group. In the present disclosure, the heteroaryl in the heteroarylamine can be applied to the aforementioned description of the heteroaryl group. In the present disclosure, the alkenyl group in the aralkenyl group is the same as the aforementioned examples of the alkenyl group. In the present disclosure, the aforementioned description of the aryl group can be applied except that the arylene is a divalent group. In the present disclosure, the aforementioned description of the heteroaryl group can be applied except that the heteroarylene is a divalent group. In the present disclosure, the aforementioned description of the aryl group or cycloalkyl group can be applied except that the hydrocarbon ring is not a monovalent group but formed by combining two substituent groups. In the present disclosure, the aforementioned description of the heteroaryl group can be applied, except that the heteroaryl is not a monovalent group but formed by combining two substituent groups.
Preferably, Ar1 and Ar2 can be each independently a substituted or unsubstituted C6-20 aryl; or a substituted or unsubstituted C2-20 heteroaryl containing any one or more heteroatoms selected from the group consisting of N, O and S.
More preferably, Ar1 and Ar2 can be each independently phenyl, biphenylyl, terphenylyl, naphthyl, phenyl naphthyl, naphthyl phenyl, phenanthrenyl, phenyl phenanthrenyl, binaphthylyl, chrysenyl, or benzo[c]phenanthrenyl, and the Ar1 and Ar2 are each independently unsubstituted or substituted with at least one deuterium.
Preferably, Ar can be phenyl unsubstituted or substituted with deuterium, or naphthyl unsubstituted or substituted with deuterium. More preferably, Ar can be phenyl or naphthyl.
Preferably, at least one of Ar1 and Ar2 is a substituted or unsubstituted naphthyl, a substituted or unsubstituted phenanthrenyl, chrysenyl, or benzo[c]phenanthrenyl, and the substituted or unsubstituted naphthyl, the substituted or unsubstituted phenanthrenyl, chrysenyl, or benzo[c]phenanthrenyl can be unsubstituted or substituted with at least one deuterium.
More preferably, at least one of Ar1 and Ar2 is naphthyl, phenyl naphthyl, binaphthylyl, phenanthrenyl, phenyl phenanthrenyl, chrysenyl, or benzo[c]phenanthrenyl, and the naphthyl, phenyl naphthyl, binaphthyl, phenanthrenyl, phenyl phenanthrenyl, chrysenyl, or benzo[c]phenanthrenyl can be unsubstituted or substituted with at least one deuterium.
Preferably, at least one of Ar1 and Ar2 can be substituted with deuterium.
Preferably, at least one of R1 to R7 can be deuterium.
Preferably, at least one of Ar1 and Ar2 can be substituted with deuterium, or at least one of R1 to R7 can be deuterium. More preferably, at least one of Ar1 and Ar2 is substituted with deuterium, and at least one of R1 to R7 can be deuterium. More preferably, at least one of Ar1 and Ar2 is phenyl substituted with deuterium or naphthyl substituted with deuterium; or at least five of R1 to R7 can be deuterium. Most preferably, at least one of Ar1 and Ar2 is phenyl substituted with five deuteriums or naphthyl substituted with seven deuteriums; or R1 and R3 to R5 can be deuterium.
Preferably, the compound of Chemical Formula 1 can be substituted with at least five deuteriums.
Representative examples of the compound of Chemical Formula 1 are as follows:
in the above compound, a+b+c is an integer of 1 to 19,
in the above compound, a+b+c is an integer of 1 to 21,
in the above group, a+b+c+d is an integer of 1 to 23,
in the above group, a+b+c+d is an integer of 1 to 25,
in the above group, a+b+c is an integer of 1 to 23,
in the above group, a+b+c is an integer of 1 to 25,
In the compounds, D is deuterium, and a to e are the number of deuterium substituted in each substituent.
The compound of Chemical Formula 1 can be prepared by a preparation method as shown in the following Reaction Scheme 1 as an example, and other remaining compounds can also be prepared in a similar manner:
wherein in Reaction Scheme 1, R1 to R7, Ar1 and Ar2 are as defined in
Chemical Formula 1, and X is halogen, preferably X is chloro or bromo.
Reaction Scheme 1 is a Suzuki coupling reaction, which is preferably carried out in the presence of a palladium catalyst and a base, and a reactive group for the Suzuki coupling reaction can be modified as known in the art. The preparation method can be further embodied in Preparation Examples described hereinafter.
Further, the present disclosure provides an organic light emitting device comprising a compound of Chemical Formula 1. In one example, the present disclosure provides an organic light emitting device comprising: a first electrode; a second electrode that is opposite to the first electrode; and one or more organic material layers that are between the first electrode and the second electrode, wherein one or more layers of the one or more organic material layers includes the compound of Chemical Formula 1.
The organic material layer of the organic light emitting device of the present disclosure can have a single-layer structure, or it can have a multilayered structure in which two or more organic material layers are stacked. For example, the organic light emitting device of the present disclosure can have a structure comprising a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer and the like as the organic material layer. However, the structure of the organic light emitting device is not limited thereto, and it can include a smaller number of organic layers.
Further, the organic material layer can include a light emitting layer, wherein the light emitting layer can include the compound of Chemical Formula 1.
Further, the organic material layer can include a hole transport layer, a hole injection layer, or a layer that simultaneously performs hole transport and hole injection, wherein the hole transport layer, the hole injection layer, or the layer that simultaneously performs hole transport and hole injection can include the compound of Chemical Formula 1.
Further, the organic material layer can include an electron transport layer, an electron injection layer, or an electron transport and injection layer, wherein the electron transport layer, the electron injection layer, or the electron transport and injection layer can include the compound of Chemical Formula 1.
Further, the organic light emitting device according to the present disclosure can be a normal type organic light emitting device in which an anode, one or more organic material layers, and a cathode are sequentially stacked on a substrate. Further, the organic light emitting device according to the present disclosure can be an inverted type organic light emitting device in which a cathode, one or more organic material layers, and an anode are sequentially stacked on a substrate. For example, the structure of the organic light emitting device according to an embodiment of the present disclosure is illustrated in
In such a structure, the compound of Chemical Formula 1 can be included in the light emitting layer.
The organic light emitting device according to the present disclosure can be manufactured by materials and methods known in the art, except that at least one of the organic material layers includes the compound of Chemical Formula 1. Further, when the organic light emitting device includes a plurality of organic material layers, the organic material layers can be formed of the same material or different materials.
For example, the organic light emitting device according to the present disclosure can be manufactured by sequentially stacking a first electrode, an organic material layer and a second electrode on a substrate. In this case, the organic light emitting device can be manufactured by depositing a metal, metal oxides having conductivity, or an alloy thereof on the substrate using a PVD (physical vapor deposition) method such as a sputtering method or an e-beam evaporation method to form an anode, forming organic material layers including the hole injection layer, the hole transport layer, the light emitting layer and the electron transport layer thereon, and then depositing a material that can be used as the cathode thereon. In addition to such a method, the organic light emitting device can be manufactured by sequentially depositing a cathode material, an organic material layer and an anode material on a substrate.
Further, the compound of Chemical Formula 1 can be formed into an organic layer by a solution coating method as well as a vacuum deposition method at the time of manufacturing an organic light emitting device. Wherein, the solution coating method means a spin coating, a dip coating, a doctor blading, an inkjet printing, a screen printing, a spray method, a roll coating, or the like, but is not limited thereto.
In addition to such a method, the organic light emitting device can be manufactured by sequentially depositing a cathode material, an organic material layer and an anode material on a substrate (International Publication WO2003/012890). However, the manufacturing method is not limited thereto.
In one example, the first electrode is an anode, and the second electrode is a cathode, or alternatively, the first electrode is a cathode and the second electrode is an anode.
As the anode material, generally, a material having a large work function is preferably used so that holes can be smoothly injected into the organic material layer. Specific examples of the anode material include metals such as vanadium, chrome, copper, zinc, and gold, or an alloy thereof; metal oxides such as zinc oxides, indium oxides, indium tin oxides (ITO), and indium zinc oxides (IZO); a combination of metals and oxides, such as ZnO:Al or SnO2: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.
As the cathode material, generally, a material having a small work function is preferably used so that electrons can be easily injected into the organic material layer. Specific examples of the cathode material include metals such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, and lead, or an alloy thereof; a multilayered structure material such as LiF/Al or LiO2/Al, and the like, but are not limited thereto.
The hole injection layer is a layer for injecting holes from the electrode, and the hole injection material is preferably a compound which has a capability of transporting the holes, thus has a hole injecting effect in the anode and an excellent hole injecting effect to the light emitting layer or the light emitting material, prevents excitons produced in the light emitting layer from moving to an electron injection layer or the electron injection material, and further is excellent in the ability to form a thin film. It is preferable that a HOMO (highest occupied molecular orbital) of the hole injection material is between the work function of the anode material and a HOMO of a peripheral organic material layer. Specific examples of the hole injection material include metal porphyrin, oligothiophene, an arylamine-based organic material, a hexanitrilehexaazatriphenylene-based organic material, a quinacridone-based organic material, a perylene-based organic material, anthraquinone, polyaniline and polythiophene-based conductive polymer, and the like, but are not limited thereto.
The hole transport layer is a layer that receives holes from a hole injection layer and transports the holes to the light emitting layer. The hole transport material is suitably a material having large mobility to the holes, which can receive holes from the anode or the hole injection layer and transfer the holes to the light emitting layer. Specific examples thereof include an arylamine-based organic material, a conductive polymer, a block copolymer in which a conjugate portion and a non-conjugate portion are present together, and the like, but are not limited thereto.
The electron blocking layer means a layer provided between the hole transport layer and the light emitting layer in order to prevent the electrons injected from the cathode from being transferred to the hole transport layer without being recombined in the light emitting layer, which can also be referred to as an electron inhibition layer. The electron blocking layer is preferably a material having the smaller electron affinity than the electron transport layer.
The light emitting material is preferably a material which can receive holes and electrons transported from a hole transport layer and an electron transport layer, respectively, and combine the holes and the electrons to emit light in a visible ray region, and has good quantum efficiency to fluorescence or phosphorescence. Specific examples of the light emitting material include an 8-hydroxy-quinoline aluminum complex (Alq3); a carbazole-based compound; a dimerized styryl compound; BAlq; a 10-hydroxybenzoquinoline-metal compound; a benzoxazole, benzothiazol and benzimidazole-based compound; a poly(p-phenylenevinylene)(PPV)-based polymer; a spiro compound; polyfluorene, rubrene, and the like, but are not limited thereto.
The light emitting layer can include a host material and a dopant material. The host material includes a fused aromatic ring derivative, a heterocycle-containing compound, or the like. Specific examples of the fused aromatic ring derivatives include anthracene derivatives, pyrene derivatives, naphthalene derivatives, pentacene derivatives, phenanthrene compounds, fluoranthene compounds, and the like. Examples of the heterocyclic-containing compounds include carbazole derivatives, dibenzofuran derivatives, ladder-type furan compounds, pyrimidine derivatives, and the like, but are not limited thereto. Preferably, the compound of Chemical Formula 1 can be used as a host material of the light emitting layer.
Preferably, the light emitting layer can further comprise a compound of the following Chemical Formula 2:
A1 to A3 are each independently a substituted or unsubstituted C6-60 aryl or a substituted or unsubstituted C2-60 heteroaryl containing any one or more heteroatoms selected from the group consisting of N, O and S; and
L1 to L3 are each independently a single bond, a substituted or unsubstituted C6-60 arylene, or a substituted or unsubstituted C2-60 heteroarylene containing any one or more selected from the group consisting of N, O and S.
Examples of the dopant material include an aromatic amine derivative, a styrylamine compound, a boron complex, a fluoranthene compound, a metal complex, and the like. Specifically, the aromatic amine derivative is a substituted or unsubstituted fused aromatic ring derivative having an arylamino group, and examples thereof include pyrene, anthracene, chrysene, periflanthene and the like, which have an arylamino group. The styrylamine compound is a compound where at least one arylvinyl group is substituted in substituted or unsubstituted arylamine, in which one or two or more substituent groups selected from the group consisting of an aryl group, a silyl group, an alkyl group, a cycloalkyl group, and an arylamino group are substituted or unsubstituted. Specific examples thereof include styrylamine, styryldiamine, styryltriamine, styryltetramine, and the like, but are not limited thereto. Further, the metal complex includes an iridium complex, a platinum complex, and the like, but is not limited thereto.
The electron transport layer is a layer which receives electrons from an electron injection layer and transports the electrons to a light emitting layer, and an electron transport material is suitably a material which can receive electrons well from a cathode and transfer the electrons to a light emitting layer, and has a large mobility for electrons. Specific examples of the electron transport material include: an Al complex of 8-hydroxyquinoline; a complex including Alq3; an organic radical compound; a hydroxyflavone-metal complex, 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 related art. In particular, appropriate examples of the cathode material are a typical material which has a low work function, followed by an aluminum layer or a silver layer. Specific examples thereof include cesium, barium, calcium, ytterbium, and samarium, in each case followed by an aluminum layer or a silver layer.
The electron injection layer is a layer which injects electrons from an electrode, and is preferably a compound which has a capability of transporting electrons, has an effect of injecting electrons from a cathode and an excellent effect of injecting electrons into a light emitting layer or a light emitting material, prevents excitons produced from the light emitting layer from moving to a hole injection layer, and is also excellent in the ability to form a thin film. Specific examples of the electron injection layer include fluorenone, anthraquinodimethane, diphenoquinone, thiopyran dioxide, oxazole, oxadiazole, triazole, imidazole, perylenetetracarboxylic acid, fluorenylidene methane, anthrone, and the like, and derivatives thereof, a metal complex compound, a nitrogen-containing 5-membered ring derivative, and the like, but are not limited thereto.
Examples of the metal complex compound include 8-hydroxy-quinolinato 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-hydroxy-quinolinato)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-naphtholato)gallium, and the like, but are not limited thereto.
On the other hand, in the present disclosure, the “electron transport and injection layer” is a layer that performs both the roles of the electron injection layer and the electron transport layer, and the materials that perform the roles of each layer can be used alone or stacked and used in combination, without being limited thereto.
The organic light emitting device according to the present disclosure can be a bottom emission device, a top emission device, or a double-sided light emitting device, and particularly, can be a bottom emission device that requires relatively high luminous efficiency.
In addition, the compound of Chemical Formula 1 can be included in an organic solar cell or an organic transistor in addition to an organic light emitting device.
Below, the embodiments are described in more detail to assist in the understanding of the present disclosure. However, the following examples are provided for illustrative purposes only, and are not intended to limit the subject matter of the present disclosure.
2-Chloro-4-(phenyl-d5)-6-(6-phenylnaphthalen-2-yl)-1,3,5-triazine (15.0 g, 37.6 mmol) and dibenzo[b,d]furan-1-ylboronic acid (8.8 g, 41.4 mmol) were added to 300 ml of THE under a nitrogen atmosphere, and the mixture was stirred and refluxed. Then, potassium carbonate (20.8 g, 150.4 mmol) was dissolved in 62 ml of water and added thereto, and the mixture was sufficiently stirred and then tetrakis(triphenylphosphine)palladium(0) (0.2 g, 1.1 mmol) was added. After reacting for 9 hours, the reaction mixture was cooled to room temperature, and then the organic layer and the aqueous layer were separated, and the organic layer was distilled. This was again dissolved in chloroform, washed twice with water, and then the organic layer was separated, anhydrous magnesium sulfate was added, stirred, then filtered, and the filtrate was distilled under reduced pressure. The concentrated compound was purified by a silica gel column chromatography and then subjected to sublimation purification to give 9.0 g of Compound 1. (Yield: 45%, MS: [M+H]+=532)
Compound 2 was prepared in the same manner as in the preparation method of Compound 1, except that in Preparation Example 1, 2-([2,2′-binaphthalen]-6-yl-1′,3′,4′,5′,6′,7′,8′-d7)-4-chloro-6-phenyl-1,3,5-triazine was used instead of 2-chloro-4-(phenyl-d5)-6-(6-phenylnaphthalen-2-yl)-1,3,5-triazine. (MS[M+H]+=584)
Compound 3 was prepared in the same manner as in the preparation method of Compound 1, except that in Preparation Example 1, 2-chloro-4-(naphthalen-2-yl)-6-(6-phenylnaphthalen-2-yl)-1,3,5-triazine was used instead of 2-chloro-4-(phenyl-d5)-6-(6-phenylnaphthalen-2-yl)-1,3,5-triazine, and (dibenzo[b,d]furan-1-yl-2,4,6,7,8-d5)boronic acid was used instead of dibenzo[b,d]furan-1-ylboronic acid. (MS[M+H]+=582)
Compound 4 was prepared in the same manner as in the preparation method of Compound 1, except that in Preparation Example 1, 2-([1,2′-binaphthalen]-6′-yl)-4-chloro-6-phenyl-1,3,5-triazine was used instead of 2-chloro-4-(phenyl-d5)-6-(6-phenylnaphthalen-2-yl)-1,3,5-triazine, and (dibenzo[b,d]furan-1-yl-d7)boronic acid was used instead of dibenzo[b,d]furan-1-ylboronic acid. (MS[M+H]+=584)
Compound 5 was prepared in the same manner as in the preparation method of Compound 1, except that in Preparation Example 1, 2-chloro-4-(naphthalen-2-yl-d7)-6-(phenanthren-3-yl)-1,3,5-triazine was used instead of 2-chloro-4-(phenyl-d5)-6-(6-phenylnaphthalen-2-yl)-1,3,5-triazine, and (dibenzo[b,d]furan-1-yl-2,4,6,7,8-d5)boronic acid was used instead of dibenzo[b,d]furan-1-ylboronic acid. (MS[M+H]+=563)
2-Chloro-4-phenyl-6-(7-phenylphenanthren-2-yl)-1,3,5-triazine (15 g, 33.8 mmol) and dibenzo[b,d]furan-1-ylboronic acid (7.9 g, 37.2 mmol) were added to 300 ml of THE under a nitrogen atmosphere, and the mixture was stirred and refluxed. Then, potassium carbonate (18.7 g, 135.2 mmol) was dissolved in 56 ml of water and added thereto, and the mixture was sufficiently stirred and then tetrakis(triphenylphosphine)palladium(0) (0.1 g, 1 mmol) was added. After reacting for 8 hours, the reaction mixture was cooled to room temperature, and then the organic layer and the aqueous layer were separated, and the organic layer was distilled. This was again dissolved in chloroform, washed twice with water, and then the organic layer was separated, anhydrous magnesium sulfate was added, stirred, then filtered, and the filtrate was distilled under reduced pressure. The concentrated compound was purified by a silica gel column chromatography to give 11.7 g of Compound 6-a. (Yield: 60%, MS: [M+H]+=577)
Compound 6-a (10.0 g, 17.4 mmol), PtO2 (1.2 g, 5.2 mmol) and D2O (87 ml) were added to a shaker tube, and then the tube was sealed and heated at 250° C. and 600 psi for 12 hours. When the reaction was completed, chloroform was added thereto, and the reaction solution was transferred to a separatory funnel, and extracted. The extract was dried over MgSO4 and concentrated, and then the sample was purified by silica gel column chromatography and then subjected to sublimation purification to give 5.1 g of Compound 6. (Yield: 49%, MS: [M+H]+=602)
A glass substrate on which a thin film of ITO (indium tin oxide) was coated in a thickness of 1,400 Å was put into distilled water containing a detergent dissolved therein and ultrasonically cleaned. At this time, the used detergent was Decon™ CON705 product available from Fischer Co. and the distilled water was one which had been twice filtered by using a 0.22 μm sterilizing filter available from Millipore Co. The ITO was cleaned for 30 minutes, and ultrasonic cleaning was then repeated twice for 10 minutes by using distilled water. After the cleaning with distilled water was completed, the substrate was ultrasonically washed with the solvents of isopropyl alcohol, acetone, and methanol for 10 minutes, and dried, after which it was transported to a plasma cleaner. Then, the substrate was cleaned with oxygen plasma for 5 minutes, and then transferred to a vacuum evaporator.
On the ITO transparent electrode thus prepared, the following Compound HI-A and Compound LG-101 were sequentially thermally vacuum-deposited to a thickness of 800 Å and 50 Å, respectively, to form a hole injection layer. The following Compound HT-A was vacuum-deposited thereon to a thickness of 800 Å as a hole transport layer, and then, the following Compound EB-A was thermally vacuum-deposited to a thickness of 600 Å as an electron blocking layer. The following Compound RH-A was applied as a host for the light emitting layer, and the following Compound RD-A was applied as a dopant, and the host and dopant were vacuum-deposited at a weight ratio of 98:2 to a thickness of 400 A. Then, the following Compound ET-A and Compound Liq were thermally vacuum-deposited at a ratio of 1:1 to a thickness of 360 Å, and then Compound Liq was vacuum-deposited to a thickness of 5 Å as an electron transport and injection layer.
Magnesium and silver were sequentially deposited in a weight ratio of 10:1 to a thickness of 220 Å, and aluminum to a thickness of 1000 Å on the electron injection layer to form a cathode, thereby completing the manufacture of an organic light emitting device.
The organic light emitting devices of Examples 1 to 9 and Comparative Examples 2 to 8 were manufactured in the same manner as in Comparative Example 1, except that in Comparative Example 1, Compound RH-A was changed as shown in Table 1 below. At this time, when a mixture of two types of Compounds was used as the host, the numbers inside the parentheses means the weight ratio between the host compounds. The structures of Compound pRH-1, Compound pRH-2, and Compounds A to F shown in Table 1 below are as follows.
The driving voltage, efficiency and lifetime were measured by applying a current to the organic light emitting devices manufactured in Examples 1 to 9 and Comparative Examples 1 to 8, and the results are shown in Table 1 below. At this time, the voltage and efficiency were measured by applying a current density of 10 mA/cm2, and the lifetime (LT97) means the time required for the luminance to be reduced to 97% of the initial luminance at a current density of 20 mA/cm2.
According to the disclosure in Table 1, it can be seen that a structure in which triazine is directly bonded to the 1-position of dibenzofuran substituted only with hydrogen or deuterium exhibits high electron injection and mobility characteristics and thus low voltage characteristics. In particular, it was easy to adjust the charge balance in the light emitting layer when simultaneously applied with a p-type host having excellent hole transport properties, such as Compound pRH-1 or pRH-2. Further, an aryl group fused with two or more benzene rings included in at least one of Ar1 and Ar2 lowers the triplet energy of the material, and, particularly, facilitates energy transfer to the red light emitting dopant, thereby exhibiting high efficiency characteristics. In addition, when deuterium is substituted as shown in Chemical Formula 1, the vibrational energy of the material is lowered, which not only increases the stability of the material, but also increases the stability of the exciplex formed with the p-type host, thereby exhibiting long life characteristics.
From the above results, it was confirmed that when the compounds having the structure of Chemical Formula 1 were applied to the light emitting layer of the organic light emitting device, a device having characteristics of low voltage, high efficiency, and long lifetime could be obtained.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2022-0057910 | May 2022 | KR | national |
| 10-2023-0057176 | May 2023 | KR | national |
This application is a National Stage Application of International Application No. PCT/KR2023/006081 filed on May 3, 2023, which claims priority to and claims the benefit of Korean Patent Application No. 10-2022-0057910 filed on May 11, 2022 and Korean Patent Application No. 10-2023-0057176 filed on May 2, 2023 in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2023/006081 | 5/3/2023 | WO |
