Patent Application
20240090318
The present disclosure relates to a novel compound useful for an organic light-emitting diode and, more specifically, to a novel compound that can be used as a host material in an organic light-emitting diode and allows for excellent diode characteristics including high luminous efficiency, low driving voltage, and high longevity, and an organic light-emitting diode including same.
Organic light-emitting diodes (OLEDs), based on self-luminescence, enjoy the advantage of having a wide viewing angle and being able to be made thinner and lighter than liquid crystal displays (LCDs). In addition, an OLED display exhibits a very fast response time. Accordingly, OLEDs find applications in the illumination field as well as the full-color display field.
In general, the term “organic light-emitting phenomenon” refers to a phenomenon in which electrical energy is converted to light energy by means of an organic material. An OLED using the organic light-emitting phenomenon has a structure usually comprising an anode, a cathode, and an organic material layer interposed therebetween. In this regard, the organic material layer may be, for the most part, of a multilayer structure consisting of different materials, for example, a hole injecting layer, a hole transport layer, a light-emitting layer, an electron transport layer, and an electron injecting layer, in order to improve the efficiency and stability of the organic light-emitting diode (OLED). In the organic light-emitting diode having such a structure, when a voltage is applied between the two electrodes, a hole injected from the anode migrates to the organic layer while an electron is released from the cathode and moves toward the organic layer. In the luminescent zone, the hole and the electron recombine to produce an exciton. When the exciton returns to the ground state from the excited state, the molecule of the organic layer emits light. Such an organic light-emitting diode is known to have characteristics such as self-luminescence, high luminance, high efficiency, low driving voltage, a wide viewing angle, high contrast, and high-speed response.
Materials used as organic layers in OLEDs may be divided into luminescent materials and charge transport materials, for example, a hole injection material, a hole transport material, an electron injection material, and an electron transport material. As for the luminescent materials, there are two main families of OLED: those based on small molecules and those employing polymers. The light-emitting mechanism forms the basis for classification of the luminescent materials as fluorescent or phosphorescent materials, which use excitons in singlet and triplet states, respectively.
Meanwhile, when a single material is employed as the luminescent material, intermolecular actions cause the wavelength of maximum luminescence to shift toward a longer wavelength, decreasing color purity or attenuating light with consequent reduction in the efficiency of the diode. In this regard, a host-dopant system may be used as a luminescent material so as to increase the color purity and the light emission efficiency through energy transfer.
This is based on the principle whereby, when a dopant is smaller in energy band gap than a host accounting for the light-emitting layer, the addition of a small amount of the dopant to the host generates excitons from the light-emitting layer so that the excitons are transported to the dopant, emitting light at high efficiency. Here, light of desired wavelengths can be obtained depending on the kind of dopant because the wavelength of the host moves to the wavelength range of the dopant.
For use as host compounds in a light-emitting layer, heterocyclic compounds have been recently studied. With regard to related art, reference may be made to Korean Patent No. 10-2016-0089693 A (Jul. 28, 2016), which discloses a compound structured to have a dibenzofuran ring moiety bonded to an anthracene ring, and an organic light-emitting diode including same. Also, Korean patent No. 10-0874749 (Dec. 29, 2008) introduces a blue light-emitting compound in which an arylamine is coupled to a pyrene ring, and an organic light-emitting diode including same.
In addition, Korean Patent No. 10-2017-0055743 A (May 22, 2017) discloses a compound in which an aryl substituent or a heteroaryl substituent is bonded to a fused fluorene ring bearing a heteroatom such as oxygen, nitrogen, sulfur, etc., and an organic light-emitting diode including same.
Despites a variety of types of compounds prepared for use in light emitting layers in organic light emitting diodes including the related arts, there is still a continuing need to develop a novel compound that allows an OLED to be stably driven at a lower voltage with high efficiency and longevity, and an OLED including same.
Therefore, an aspect of the present disclosure is to provide a novel organic compound which can be used as a host material in a light-emitting layer of an organic light-emitting diode.
In addition, another aspect of the present disclosure is to provide an organic light-emitting diode (OLED) having the organic compound as a host material therein and exhibiting characteristics including high luminous efficiency, low-voltage driving, and high longevity.
In order to accomplish the purposes, the present disclosure provides an organic compound represented by the following Chemical Formula A:
When used as a host material, the novel compound represented by Chemical Formula A according to the present disclosure allows for the provision of an organic light-emitting diode that can be driven at a lower voltage with improved luminous efficiency and longevity, compared to conventional organic light-emitting diodes.
FIGURE is a schematic diagram of an OLED according to some embodiments of the present disclosure.
Hereinafter, exemplary embodiments which can be easily implemented by those skilled in the art will be described with reference to the accompanying drawing. In each drawing of the present disclosure, sizes or scales of components may be enlarged or reduced from their actual sizes or scales for better illustration, and known components may not be depicted therein to clearly show features of the present disclosure. Therefore, the present disclosure is not limited to the drawings. When describing the principle of the embodiments of the present disclosure in detail, details of well-known functions and features may be omitted to avoid unnecessarily obscuring the presented embodiments.
In drawings, for convenience of description, sizes of components may be exaggerated for clarity. For example, since sizes and thicknesses of components in drawings are arbitrarily shown for convenience of description, the sizes and thicknesses are not limited thereto. Furthermore, throughout the description, the terms “on” and “over” are used to refer to the relative positioning, and mean not only that one component or layer is directly disposed on another component or layer but also that one component or layer is indirectly disposed on another component or layer with a further component or layer being interposed therebetween. Also, spatially relative terms, such as “below”, “beneath”, “lower”, and “between” may be used herein for ease of description to refer to the relative positioning.
Throughout the specification, when a portion may “comprise” or “include” a certain constituent element, unless explicitly described to the contrary, it may not be construed to exclude another constituent element but may be construed to further include other constituent elements. Further, throughout the specification, the word “on” means positioning on or below the object portion, but does not essentially mean positioning on the lower side of the object portion based on a gravity direction.
The present disclosure provides an organic compound represented by the following Chemical Formula A:
The expression indicating the number of carbon atoms, such as “a substituted or unsubstituted alkyl of 1 to 30 carbon atoms”, “a substituted or unsubstituted aryl of 5 to 50 carbon atoms”, etc. means the total number of carbon atoms of, for example, the alkyl or aryl radical or moiety alone, exclusive of the number of carbon atoms of substituents attached thereto. For instance, a phenyl group with a butyl at the para position falls within the scope of an aryl of 6 carbon atoms, even though it is substituted with a butyl radical of 4 carbon atoms.
As used herein, the term “aryl” means an organic radical derived from an aromatic hydrocarbon by removing one hydrogen that is bonded to the aromatic hydrocarbon. Further, the aromatic system may include a fused ring that is formed by adjacent substituents on the aryl radical.
Concrete examples of the aryl include phenyl, o-biphenyl, m-biphenyl, p-biphenyl, o-terphenyl, m-terphenyl, p-terphenyl, naphthyl, anthryl, phenanthryl, pyrenyl, indenyl, fluorenyl, tetrahydronaphthyl, perylenyl, chrysenyl, naphthacenyl, and fluoranthenyl at least one hydrogen atom of which may be substituted by a deuterium atom, a halogen atom, a hydroxy, a nitro, a cyano, a silyl, an amino (—NH2, —NH(R), —N(R′)(R″) wherein R′ and R″ are each independently an alkyl of 1 to 10 carbon atoms, in this case, called “alkylamino”), an amidino, a hydrazine, a hydrazone, a carboxyl, a sulfonic acid, a phosphoric acid, an alkyl of 1 to 24 carbon atoms, a halogenated alkyl of 1 to 24 carbon atoms, an alkenyl of 2 to 24 carbon atoms, an alkynyl of 2 to 24 carbon atoms, a heteroalkyl of 1 to 24 carbon atoms, an aryl of 6 to 24 carbon atoms, an arylalkyl of 6 to 24 carbon atoms, a heteroaryl of 2 to 24 carbon atoms, or a heteroarylalkyl of 2 to 24 carbon atoms.
The substituent heteroaryl used in the compound of the present disclosure refers to a cyclic aromatic system of 2 to 24 carbon atoms bearing as ring members one to three heteroatoms selected from among N, O, P, Si, S, Ge, Se, and Te. In the aromatic system, two or more rings may be fused. One or more hydrogen atoms on the heteroaryl may be substituted by the same substituents as on the aryl.
In addition, the term “heteroaromatic ring”, as used herein, refers to an aromatic hydrocarbon ring bearing as aromatic ring members 1 to 3 heteroatoms selected particularly from N, O, P, Si, S, Ge, Se, and Te.
As used herein, the term “alkyl” refers to an alkane missing one hydrogen atom and includes linear or branched structures. Examples of the alkyl substituent useful in the present disclosure include methyl, ethyl, propyl, isopropyl, isobutyl, sec-butyl, tert-butyl, pentyl, iso-amyl, and hexyl. At least one hydrogen atom of the alkyl may be substituted by the same substituent as in the aryl.
The term “cyclo” as used in substituents of the present disclosure, such as cycloalkyl, cycloalkoxy, etc., refers to a structure responsible for a mono- or polycyclic ring of saturated hydrocarbons such as alkyl, alkoxy, etc. Concrete examples of cycloalkyl radicals include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methylcyclopentyl, methylcyclohexyl, ethylcyclopentyl, ethylcyclohexyl, adamantyl, dicyclopentadienyl, decahydronaphthyl, norbornyl, bornyl, and isobornyl. One or more hydrogen atoms on the cycloalkyl may be substituted by the same substituents as on the aryl and it can be applied to cycloalkoxy, as well.
The term “alkoxy” as used in the compounds of the present disclosure refers to an alkyl or cycloalkyl singularly bonded to oxygen. Concrete examples of the alkoxy include methoxy, ethoxy, propoxy, isobutoxy, sec-butoxy, pentoxy, iso-amyloxy, hexyloxy, cyclobutyloxy, cyclopentyloxy, adamantyloxy, dicyclopentyloxy, bornyloxy, and isobornyloxy. One or more hydrogen atoms on the alkoxy may be substituted by the same substituents as on the aryl.
Concrete examples of the arylalkyl used in the compounds of the present disclosure include phenylmethyl(benzyl), phenylethyl, phenylpropyl, naphthylmethyl, and naphthylethyl. One or more hydrogen atoms on the arylalkyl may be substituted by the same substituents as on the aryl.
Concrete examples of the silyl radicals used in the compounds of the present disclosure include trimethylsilyl, triethylsilyl, triphenylsilyl, trimethoxysilyl, dimethoxyphenylsilyl, diphenylmethylsilyl, diphenylvinylsilyl, methylcyclobutylsilyl, and dimethyl furylsilyl. One or more hydrogen atoms on the silyl may be substituted by the same substituents as on the aryl.
As used herein, the term “alkenyl” refers to an unsaturated hydrocarbon group that contains a carbon-carbon double bond between two carbon atoms and the team “alkynyl” refers to an unsaturated hydrocarbon group that contains a carbon-carbon triple bond between two carbon atoms.
As used herein, the term “alkylene” refers to an organic aliphatic radical regarded as derived from a linear or branched saturated hydrocarbon alkane by removal of two hydrogen atoms from different carbon atoms. Concrete examples of the alkylene include methylene, ethylene, propylene, isopropylene, isobutylene, sec-butylene, tert-butylene, pentylene, iso-amylene, hexylene, and so on. One or more hydrogen atoms on the alkylene may be substituted by the same substituents as on the aryl.
Furthermore, as used herein, the term “diarylamino” refers to an amine radical having two identical or different aryl groups bonded to the nitrogen atom thereof, the term “diheteroarylamino” refers to an amine radical having two identical or different heteroaryl groups bonded to the nitrogen atom thereof, and the term “aryl(heteroaryl)amino” refers to an amine radical having an aryl group and a heteroaryl group both bonded to the nitrogen atom thereof.
As more particular examples accounting for the term “substituted” in the expression “substituted or unsubstituted” used for compounds of Chemical Formulas A, the compounds may be substituted by at least one substituents selected from the group consisting of a deuterium atom, a cyano, a halogen, a hydroxy, a nitro, an alkyl of 1 to 12 carbon atoms, a halogenated alkyl of 1 to 12 carbon atoms, an alkenyl of 2 to 12 carbon atoms, an alkynyl of 2 to 12 carbon atoms, a cycloalkyl of 3 to 12 carbon atoms, a heteroalkyl of 1 to 12 carbon atoms, an aryl of 6 to 18 carbon atoms, an arylalkyl of 7 to 20 carbon atoms, an alkylaryl of 7 to 20 carbon atoms, a heteroaryl of 2 to 18 carbon atoms, a heteroarylalkyl of 2 to 18 carbon atoms, an alkoxy of 1 to 12 carbon atoms, an alkylamino of 1 to 12 carbon atoms, a diarylamino of 12 to 18 carbon atoms, a diheteroarylamino of 2 to 18 carbon atoms, an aryl(heteroaryl)amino of 7 to 18 carbon atoms, an alkylsilyl of 1 to 12 carbon atoms, an arylsilyl of 6 to 18 carbon atoms, an aryloxy of 6 to 18 carbon atoms, and an arylthionyl of 6 to 18 carbon atoms.
In the present disclosure, the organic compound represented by Chemical Formula A is characterized by the structure in which a linker L1 is connected to a substituted or unsubstituted pyrene ring moiety at a specific position (see the following
Structural Formula C) and linked to Ar that is any one selected from a substituted or unsubstituted aryl of 10 to 50 carbon atoms and a substituted or unsubstituted heteroaryl of 2 to 50 carbon atoms wherein when Ar is a heteroaryl of 2 to 50 carbon atoms, the aromatic ring of the heteroaryl moiety may contain 10 atoms or more which is carbon atoms or heteroatoms as ring members, and the compound represented by
Chemical Formula A has a structure symmetric about the X-Y axis, except for the substituent Z and more particularly is structurally symmetric about the X-Y axis, including the substituent Z. When employing the compound having such a structural characteristic as a host compound for a light-emitting layer therein, an organic light-emitting diode can exhibit high efficiency, low voltage driving, and long lifespan, compared to conventional light-emitting diodes.
In the compound represented by Chemical Formula A according to some more particular embodiments of the present disclosure, the linker L may be a substituted or unsubstituted arylene of 6 to 18 carbon atoms. In this regard, m may be 1 and the linker may be selected from [Structural Formula 1] and [Structural Formula 2] below:
In the compound represented by Chemical Formula A according to some more particular embodiments of the present disclosure, the linker L may be a substituted or unsubstituted arylene of 6 to 18 carbon atoms represented by the following Structural Formula 3:
In addition, n the compound represented by Chemical Formula A according to some more particular embodiments of the present disclosure, Ar may be a substituted or unsubstituted aryl of 10 to 18 carbon atoms represented by any one selected from [Structural Formula 11] to [Structural Formula 15], below, with preference for [Structural Formula 11]:
Concrete examples of Ar represented by Chemical Formulas 11 to 15 include 1-naphthyl, 2-naphthyl, 1-fluorene, 2-fluorene, 3-fluorene, 4-fluorene, 1-phenanthrene, 2-phenanthrene, 3-phenanthrene, 4-phenanthrene, and 9-phenanthrene, with preference for 1-naphthyl or 2-naphthyl.
In addition, in the compound represented by Chemical Formula A according to some more particular embodiments of the present disclosure, when the linker L is [Structural Formula 3]
Ar may be any one selected from [Structural Formula 11] to [Structural Formula 15], below, with preference for [Structural Formula 11]:
In the compound represented by Chemical Formula A according to some more particular embodiments of the present disclosure, Z may be any one selected from a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl of 1 to 12 carbon atoms, a substituted or unsubstituted cycloalkyl of 3 to 12 carbon atoms, and a substituted or unsubstituted aryl of 6 to 18 carbon atoms.
In addition, the compound represented by Chemical Formula A may be any one selected from [Chemical Formula 1] to [Chemical Formula 90], below, but is not limited thereto:
In addition, the present disclosure provides an organic light-emitting diode comprising: a first electrode: a second electrode facing the first electrode; and a light-emitting layer disposed between the first electrode and the second electrode, wherein the light-emitting layer comprises at least one of the compounds represented by Chemical Formula A.
Throughout the description of the present disclosure, the phrase “(an organic layer) includes at least one organic compound” may be construed to mean that “(an organic layer) may include a single organic compound species or two or more different species of organic compounds falling within the scope of the present disclosure”.
In this regard, the organic light-emitting diode according to the present disclosure may include at least one of a hole injection layer, a hole transport layer, a functional layer capable of both hole injection and hole transport, a light-emitting layer, an electron transport layer, and an electron injection layer.
In more particular embodiments of the present disclosure, the organic layer disposed between the first electrode and the second electrode includes a light-emitting layer composed of a host and a dopant, wherein the compound represented by Chemical Formula A serves as a host in the light-emitting layer.
In an embodiment, the organic light-emitting diode according to the present disclosure may employ a compound represented by the following Chemical Formulas D1 to Chemical Formula D10 as a dopant compound in the light-emitting layer:
Among the dopant compounds according to the present disclosure, the boron compounds represented by Chemical Formulas D3 to D10 may have, on the aromatic hydrocarbon rings or heteroaromatic rings of T1 to T9 or on the aromatic hydrocarbon rings or heteroaromatic rings of Q1 to Q3, a substituent selected from a deuterium atom, an alkyl of 1 to 24 carbon atoms, an aryl of 6 to 24 carbon atoms, an alkylamino of 1 to 24 carbon atoms, and an arylamino of 6 to 24 carbon atoms, wherein the alkyl radicals or the aryl radicals in the alkylamino of 1 to 24 carbon atoms and the arylamino of 6 to 24 carbon atoms on the rings may be linked to each other, and particularly a substituent selected from an alkyl of 1 to 12 carbon atoms, an aryl of 6 to 18 carbon atoms, an alkylamino of 1 to 12 carbon atoms, and an arylamino of 6 to 18 carbon atoms wherein the alkyl radicals or aryl radicals in the alkylamino of 1 to 12 carbon atoms and the arylamino of 6 to 18 carbon atoms on the rings may be linked to each other.
Concrete examples of the dopant compounds of Chemical Formulas D1 and D2 used in the light-emitting layer include the compounds of the following Chemical Formulas <d 1> to <d 239>:
Among the dopant compounds used in the light-emitting layer, the compound represented by Chemical Formula D3 may be any one of the following <D 101> to <D 130>:
Examples of the compound represented by any one of [Chemical Formula D4], [Chemical Formula D5], and [Chemical Formula D8] to [Chemical Formula D10] include the compounds of the following [D 201] to [D 476]:
Among the dopant compounds for the light-emitting layer, the compound represented by any one of [Chemical Formula D6] and [Chemical Formula D7] may be any one selected from <D 501> to <D 587>, below:
The content of the dopant in the light-emitting layer may range from about 0.01 to 20 parts by weight, based on 100 parts by weight of the host, but is not limited thereto.
In addition to the above-mentioned dopants and hosts, the light-emitting layer may further include various hosts and dopant materials.
Below, the organic light-emitting diode of the present disclosure will be explained with reference to the drawing.
FIGURE is a schematic cross-sectional view of the structure of an organic light-emitting diode according to an embodiment of the present disclosure.
As shown in FIGURE, the organic light-emitting diode according to an embodiment of the present disclosure comprises: an anode (20); a first emission part including a hole transport layer (40), a light-emitting layer (50) containing a host and a dopant, an electron transport layer (60), and a cathode (80) in that order, wherein the anode and the cathode serve as a first electrode and a second electrode, respectively, with the interposition of the hole transport layer between the anode and the light-emitting layer, and the electron transport layer between the light-emitting layer and the cathode.
Furthermore, the organic light-emitting diode according to an embodiment of the present disclosure may comprise a hole injection layer (30) between the anode (20) and the hole transport layer (40), and an electron injection layer (70) between the electron transport layer (60) and the cathode (80).
Reference is made to FIGURE with regard to the organic light emitting diode of the present disclosure and the fabrication method therefor.
First, a substrate (10) is coated with an anode electrode material to form an anode (20). So long as it is used in a typical organic electroluminescence (EL) device, any substrate may be used as the substrate (10). Preferable is an organic substrate or transparent plastic substrate that exhibits excellent transparency, surface smoothness, ease of handling, and waterproofness. As the anode electrode material, indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO2), or zinc oxide (ZnO), which are transparent and superior in terms of conductivity, may be used.
A hole injection layer material is applied on the anode (20) by thermal deposition in a vacuum or by spin coating to form a hole injection layer (30). Subsequently, thermal deposition in a vacuum or by spin coating may also be conducted to form a hole transport layer (40) with a hole transport layer material on the hole injection layer (30).
So long as it is typically used in the art, any material may be selected for the hole injection layer without particular limitations thereto. Examples include, but are not limited to, 2-TNATA [4,4′,4″-tris(2-naphthylphenyl-phenylamino)-triphenylamine], NPD [N,N′-di(1-naphthyl)-N,N′-diphenylbenzidine)], TPD [N,N′-diphenyl-N,N′-bis(3-methylphenyl)-1,1′-biphenyl-4,4′-diamine], and DNTPD [N,N′-diphenyl-N,N′-bis-[4-(phenyl-m-tolyl-amino)-phenyl]-biphenyl-4,4′-diamine].
Any material that is typically used in the art may be selected for the hole transport layer without particular limitations thereto. Examples include, but are not limited to, N,N′-bis(3-methylphenyl)-N,N′-diphenyl-[1,1-biphenyl]-4,4′-diamine (TPD) and N,N′-di(naphthalen-1-yl)-N,N′-diphenylbenzidine (a-NPD).
In an embodiment of the present disclosure, an electron blocking layer may be additionally disposed on the hole transport layer. Functioning to prevent the electrons injected from the electron injection layer from entering the hole transport layer from the light-emitting layer, the electron blocking layer is adapted to increase the life span and luminous efficiency of the diode. The electron blocking layer may be formed at a suitable position between the light emitting layer and the hole injection layer. Particularly, the electron blocking layer may be formed between the light emitting layer and the hole transport layer.
Next, the light-emitting layer (50) may be deposited on the hole transport layer (40) or the electron blocking layer by deposition in a vacuum or by spin coating.
Herein, the light-emitting layer may contain a host and a dopant and the materials are as described above.
In some embodiments of the present disclosure, the light-emitting layer particularly ranges in thickness from 50 to 2,000 Å.
Meanwhile, the electron transport layer (60) is applied on the light-emitting layer by deposition in a vacuum and spin coating.
A material for use in the electron transport layer functions to stably carry the electrons injected from the electron injection electrode (cathode), and may be an electron transport material known in the art. Examples of the electron transport material known in the art include quinoline derivatives, particularly, tris(8-quinolinolate)aluminum (Alq3), Liq, TAZ, BAlq, beryllium bis(benzoquinolin-10-olate) (Bebq 2), Compound 201, Compound 202, BCP, and oxadiazole derivatives such as PBD, BMD, and BND, but are not limited thereto:
In the organic light emitting diode of the present disclosure, an electron injection layer (EIL) that functions to facilitate electron injection from the cathode may be deposited on the electron transport layer. The material for the EIL is not particularly limited.
Any material that is conventionally used in the art can be available for the electron injection layer without particular limitations. Examples include CsF, NaF, LiF, Li2O, and BaO. Deposition conditions for the electron injection layer may vary, depending on compounds used, but may be generally selected from condition scopes that are almost the same as for the formation of hole injection layers.
The electron injection layer may range in thickness from about 1 Å to about 100 Å, and particularly from about 3 Å to about 90 Å. Given the thickness range for the electron injection layer, the diode can exhibit satisfactory electron injection properties without actually elevating a driving voltage. In order to facilitate electron injection, the cathode may be made of a material having a small work function, such as metal or metal alloy such as lithium (Li), magnesium (Mg), calcium (Ca), an alloy aluminum (Al) thereof, aluminum-lithium (Al—Li), magnesium-indium (Mg—In), and magnesium-silver (Mg—Ag). Alternatively, ITO or IZO may be employed to form a transparent cathode for an organic light-emitting diode.
Moreover, the organic light-emitting diode of the present disclosure may further comprise a light-emitting layer containing a blue, green, or red luminescent material that emits radiations in the wavelength range of 380 nm to 800 nm. That is, the light-emitting layer in the present disclosure has a multi-layer structure wherein the blue, green, or red luminescent material may be a fluorescent material or a phosphorescent material.
Furthermore, at least one selected from among the layers may be deposited using a single-molecule deposition process or a solution process.
Here, the deposition process is a process by which a material is vaporized in a vacuum or at a low pressure and deposited to form a layer, and the solution process is a method in which a material is dissolved in a solvent and applied for the formation of a thin film by means of inkjet printing, roll-to-roll coating, screen printing, spray coating, dip coating, spin coating, etc.
Also, the organic light-emitting diode of the present disclosure may be applied to a device selected from among flat display devices, flexible display devices, monochrome or grayscale flat illumination devices, and monochrome or grayscale flexible illumination devices.
A better understanding of the present disclosure may be obtained through the following examples which are set forth to illustrate, but are not to be construed as limiting the present disclosure.
In a round-bottom flask purged with nitrogen, 1,6-dibromopyrene (10 g, 27.7 mmol), 4-(2-naphthyl)phenylboronic acid (14.5 g, 58.3 mmol), tetrakis triphenylphosphine palladium (Pd[PPh3]4) (1.3 g, 1.1 mmol), potassium carbonate (15.4 g, 111.1 mmol), toluene (50 ml), 1,4-dioxane (50 ml), and water (30 ml) were stirred together for 12 hours under reflux in a nitrogen condition. After completion of the reaction, the reaction mixture was cooled to room temperature and then subjected to extraction with ethyl acetate and water. The organic layer was concentrated in a vacuum and purification by column chromatography afforded [Chemical Formula 1] (9.5 g, yield 55%).
MS(MALDI-TOF): m/z 606.23[M]+
The same procedure as in Synthesis Example 1 was carried out, with the exception of using 3-(1-naphthyl)phenylboronic acid instead of 4-(2-naphthyl)phenylboronic acid, to afford [Chemical Formula 3] (yield 58%).
MS(MALDI-TOF): m/z 606.23[M]+
The same procedure as in Synthesis Example 1 was carried out, with the exception of using 3-(2-naphthyl)phenylboronic acid instead of 4-(2-naphthyl)phenylboronic acid, to afford [Chemical Formula 4] (yield 55%).
MS(MALDI-TOF): m/z 606.23 [M]+
The same procedure as in Synthesis Example 1 was carried out, with the exception of using 2-(naphthalen-2-yl)phenylboronic acid instead of 4-(2-naphthyl)phenylboronic acid, to afford [Chemical Formula 6] (yield 58%).
MS(MALDI-TOF) : m/z 606.23 [M]+
The same procedure as in Synthesis Example 1 was carried out, with the exception of using 3-(phenanthren-9-yl)phenylboronic acid instead of 4-(2-naphthyl)phenylboronic acid, to afford [Chemical Formula 9] (yield 54%).
MS(MALDI-TOF) : m/z 706.27 [M]+
The same procedure as in Synthesis Example 1 was carried out, with the exception of using [3-(9,9-dimethyl-9H-fluoren-2-yl)phenyl]boronic acid instead of 4-(2-naphthyl)phenylboronic acid, to afford [Chemical Formula 26] (yield 55%).
MS(MALDI-TOF) : m/z 738.33 [M]+
The same procedure as in Synthesis Example 1 was carried out, with the exception of using 1,6-dibromo-3,8-diphenylpyrene and 3-(1-naphthyl)phenylboronic acid instead of 1,6-dibromopyrene and 4-(2-naphthyl)phenylboronic acid, respectively, to afford [Chemical Formula 35] (yield 58%).
MS(MALDI-TOF) : m/z 758.30 [M]+
The same procedure as in Synthesis Example 1 was carried out, with the exception of using B-[1,2′-Binaphthalen]-4-ylboronic acid instead of 4-(2-naphthyl)phenylboronic acid, to afford [Chemical Formula 62] (yield 64%).
MS(MALDI-TOF) : m/z 706.27 [M]+
An ITO glass substrate was patterned to have a translucent area of 2 mm×2 mm and cleansed. The ITO glass was mounted in a vacuum chamber that was then set to have a base pressure of 1×10−7 torr. On the ITO glass substrate, films were sequentially formed of DNTPD (700 Å) and α-NPD (300 Å). Subsequently, a light-emitting layer (300 Å) was formed of a combination of the host according to the present disclosure and the dopant (BD) (3 wt %) described in Table 1, below. Then, [Chemical Formula E-1] and [Chemical Formula E-2] were deposited at a weight ratio of 1:1 to form an electron transport layer (300 Å) on which an electron injection layer of [Chemical Formula E-1] (10 Å) was formed and then covered with an Al layer (1000 Å) to fabricate an organic light-emitting diode. The organic light-emitting diodes thus obtained were measured at 0.4 mA for luminescence properties.
Organic light emitting diodes were fabricated in the same manner as in the Example, with the exception of using [Chemical Formula 1] and [Chemical Formula 2] as hosts instead of the compounds according to the present disclosure. The luminescence of the organic light-emitting diodes thus obtained was measured at 0.4 mA. Structures of compounds [Chemical Formula A] to [Chemical Formula F] are as follows:
As is understood from data of Table 1, the organic light-emitting diodes according to the present disclosure can drive at lower voltages with higher luminous efficiency and longer lifespan properties, compared to those of the Comparative Examples according to conventional techniques. Thus, the organic light-emitting diodes according to the present disclosure are highly available in the organic light-emitting diode field.
Compared to conventional compounds, the compounds of the present disclosure allow organic light-emitting diodes to exhibit superiority in terms of luminous efficiency, and longevity, thus finding applicability in the organic light-emitting diode field and related industrial fields.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2020-0186006 | Dec 2020 | KR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2021/019978 | 12/28/2021 | WO |
