Novel compounds and organic light-emitting elements comprising the same

Abstract

The present application provides a compound represented by the following Chemical Formula 1 and an organic light emitting element including the same: <Chemical Formula 1>

Description

Technical Field

[0001] This invention relates to a novel compound and an organic light-emitting element comprising the novel compound. Background Technology

[0002] Recently, self-emissive, low-voltage driven organic light-emitting elements have gained attention as a new generation of display elements compared to the mainstream flat panel display element, liquid crystal display (LCD). These advantages include superior viewing angle and contrast ratio, no need for backlighting, lightweight and thin design, low power consumption, and wide color reproduction range.

[0003] Materials used as organic layers in organic light-emitting elements can be broadly classified according to their function into light-emitting layer materials, hole injection materials, hole transport materials, electron transport materials, and electron injection materials.

[0004] Furthermore, the aforementioned luminescent materials can be classified into polymers and single molecules based on their molecular weight, and into fluorescent materials derived from singlet excited states of electrons, phosphorescent materials derived from triplet excited states of electrons, and delayed fluorescent materials derived from electron movement from triplet excited states to singlet excited states based on their luminescence mechanism. Additionally, luminescent materials can be classified into blue, green, yellow, and vermilion luminescent materials, which are needed to achieve a more superior natural color than red luminescent materials, based on their luminescence color.

[0005] Furthermore, to improve color purity and energy transfer-based luminescence efficiency, host / dopant type substances can also be used as luminescent materials. The principle is that by incorporating a small amount of a dopant (a luminescent material with a smaller energy band gap than the host) into the luminescent layer, excitons generated in the host can be transferred to the dopant and emit light. Using the principle described above, the desired wavelength of light can be obtained depending on the type of host and dopant.

[0006] To date, a variety of compounds have been known as suitable materials for the aforementioned organic light-emitting elements (OLEDs). However, OLEDs using these known materials suffer from problems such as high driving voltage, low efficiency, and short lifespan, necessitating the development of new materials. Therefore, researchers have consistently focused on developing OLEDs with excellent properties that enable low-voltage driving, high brightness, and long lifespan. Summary of the Invention

[0007] The purpose of this invention is to provide a novel compound and organic light-emitting element that forms a deep highest occupied molecular orbital (HOMO) while having a high lowest occupied molecular orbital (LUMO) and T1, thereby easily achieving electron interception and exciton movement interception and excellent charge balance within the light-emitting layer.

[0008] Furthermore, the present invention aims to provide a novel compound and organic light-emitting element that has a fast Hall mobility, and can ensure excellent molecular arrangement during thin film formation due to enhanced π-conjugation, thereby achieving low driving voltage and high efficiency, and can achieve long lifespan by suppressing decay phenomena.

[0009] Furthermore, the object of the present invention is to provide a novel compound and an organic light-emitting element that can prevent the recrystallization of the thin film and thereby improve driving stability due to having a high glass transition temperature (Tg).

[0010] Next, we will provide a detailed explanation of the topics mentioned above, as well as any additional topics.

[0011] As a means to solve the above problems,

[0012] An embodiment of the present invention provides a compound represented by the following chemical formula 1.

[0013] <Chemical Formula 1>

[0014]

[0015] In the above chemical formula 1,

[0016] Ar1 is a substituted or unsubstituted C6-C50 aryl group, but does not contain a fluorenyl group;

[0017] Ar2 is a phenyl group or an unsubstituted C7-C30 fused aryl group, but does not contain a fluorenyl group;

[0018] L1 and L2 are each independently a directly bonded, substituted or unsubstituted C6-C50 arylene, or a substituted or unsubstituted C2-C50 heteroarylene;

[0019] R1 to R4 are each independently hydrogen, deuterium, halogen, nitro, nitrile, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C1-C30 mercapto, substituted or unsubstituted C3-C30 silyl, substituted or unsubstituted C6-C50 aryl, or substituted or unsubstituted C2-C50 heteroaryl.

[0020] l is an integer from 0 to 4; and,

[0021] m is an integer from 0 to 4.

[0022] Furthermore, as an embodiment of the present invention, an organic light-emitting element is provided, comprising:

[0023] Electrode 1;

[0024] An organic layer is located on the first electrode described above; and,

[0025] The second electrode is located on the aforementioned organic layer;

[0026] The organic layer described above contains the compounds described above.

[0027] The aforementioned organic layer can be one or more of the following: hole injection layer, hole transport layer, and light-emitting auxiliary layer. Specifically, it can be a light-emitting auxiliary layer located between the hole transport layer and the light-emitting layer.

[0028] The compounds according to the present invention have an amino group attached to the fluorene group at position 1, 3 or 4 via a linker containing a meta-aryl group (specifically 1,3-phenylene). Therefore, they have a deep highest occupied molecular orbital (HOMO) and a high lowest occupied molecular orbital (LUMO) and T1, thereby easily achieving electron interception and exciton movement interception, and exhibiting excellent charge balance within the luminescent layer.

[0029] In particular, the compounds of the present invention can increase π-conjugation and thereby have a faster Hall mobility by including a linker containing a meta-aryl group (specifically 1,3-phenylene) and a terminal aryl group (Ar1 in Formula 1). Furthermore, they can ensure excellent molecular alignment during film formation, thereby achieving a lower driving voltage and high efficiency. They can also achieve a long service life by suppressing the decay phenomenon.

[0030] Furthermore, by including an unextended aryl group (Ar2 in Formula 1) on one side of the amino group to maintain a very deep highest occupied molecular orbital (HOMO) and a relatively high lowest occupied molecular orbital (LUMO) as well as T1, the exciton confinement effect within the luminescent layer can be maximized, thereby further improving the efficiency of the organic light-emitting element.

[0031] Furthermore, the compounds according to the present invention can have a high glass transition temperature (Tg) through the extension of the linking group between the fluorenyl group and the amine group, namely the arylene group (L1 or L2 in chemical formula 1), thereby preventing the recrystallization of the film and thereby achieving an organic light-emitting element with excellent driving stability.

[0032] Next, we will explain in detail the effects described above and the additional effects. Attached Figure Description

[0033] Figure 1 This is a schematic cross-sectional view illustrating the structure of an organic light-emitting element according to an embodiment of the present invention.

[0034] [Symbol Explanation]

[0035] 100: Substrate

[0036] 200: Hole injection layer

[0037] 300: Hole Transport Layer

[0038] 400: Emissive layer

[0039] 500: Electron transport layer

[0040] 600: Electron Injection Layer

[0041] 1000: Electrode 1 (Anode)

[0042] 2000: Second electrode (cathode) Detailed Implementation

[0043] Before providing a detailed description of the invention, it should be understood that the terminology used in this specification is for describing specific embodiments only and is not intended to limit the scope of the invention, which should be defined only by the scope of the appended claims. Unless otherwise expressly stated, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art.

[0044] Throughout this specification and the claims, unless otherwise expressly stated, the terms "comprise," "comprises," or "comprising" are used only to indicate that the mentioned object, step, or series of objects and steps are included, and do not preclude any other object, step, or series of objects or steps.

[0045] Throughout this specification and the claims, the term "aryl" refers to substances such as phenyl, benzyl, naphthyl, biphenyl, terphenyl, fluorene, phenanthrene, triphenylene, and phenylenetriene. Benzyl, fluoranyl, benzo[a]fluorene, benzo[a]triphenylene, benzo[a] Aromatic ring groups of C6 to C50, such as aryl, anthracene, piracene, and pyrene.

[0046] In addition, the term "heteroaryl" can refer to an aromatic ring of C2 to C50 containing at least one heteroelement, such as pyrrole, pyrazinyl, pyridyl, indolyl, isoindolyl, furanyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, benzothiopheneyl, dibenzothiopheneyl, quinolinyl, isoquinolinyl, quinoxalinyl, carbazoyl, phenanthridine, acridine, phenanthridine, thiopheneyl, as well as pyridine, pyrazine, pyrimidine, pyridazine, triazine, indole, quinoline, acridine, pyrrolidine, dioxane, piperidine, morpholine, piperazine, carbazole, furan, thiophene, oxazole, oxadiazole, benzoxazole, thiazole, thiadiazole, benzothiazole, benzotriazole, imidazole, benzimidazole, pyran, dibenzofuran, etc.

[0047] In addition, Ar in the chemical formula x (where x is an integer) unless otherwise explicitly defined, L represents a substituted or substituted C6-C50 aryl group, or a substituted or unsubstituted C2-C50 heteroaryl group, L x (where x is an integer) Unless otherwise explicitly defined, R represents a directly bonded, substituted or unsubstituted C6–C50 arylene, or a substituted or unsubstituted C2–C50 heteroarylene, R x (where x is an integer) Unless otherwise explicitly defined, it means hydrogen, deuterium, halogen, nitro, nitrile, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C1-C30 mercapto, substituted or unsubstituted C6-C50 aryl, or substituted or unsubstituted C2-C50 heteroaryl.

[0048] Throughout this specification and the claims, the term "substituted or unsubstituted" may refer to a group consisting of deuterium, halogen, amino, cyano, nitrile, nitro, nitrosyl, aminosulfonyl, isothiocyanate, thiocyanate, carboxyl, or C1-C30 alkyl, C1-C30 alkylsulfinyl, C1-C30 alkylsulfonyl, C1-C30 alkylthioalkyl, C1-C12 fluoroalkyl, C2-C30 alkenyl, C1-C30 alkoxy, C1 The substituted or unsubstituted group is selected from the group consisting of N-alkylamino (C12), N,N-dialkylamino (C2-C20), substituted or unsubstituted thiol (C1-C30), N-alkylaminosulfonyl (C1-C6), N,N-dialkylaminosulfonyl (C2-C12), silyl (C3-C30), cycloalkyl (C3-C20), heterocycloalkyl (C3-C20), aryl (C6-C50), and heteroaryl (C2-C50). Furthermore, throughout this specification, unless otherwise expressly stated, the same symbols may have the same meaning.

[0049] Furthermore, unless otherwise expressly stated to the contrary, various embodiments of the present invention may be combined with certain other embodiments. The embodiments of the present invention and their effects will now be described.

[0050] The present invention will now be described in detail.

[0051] The compounds according to the present invention are represented by the following chemical formula 1.

[0052] <Chemical Formula 1>

[0053]

[0054] In the above chemical formula 1,

[0055] Ar1 is a substituted or unsubstituted C6-C50 aryl group, but does not contain a fluorenyl group;

[0056] Ar2 is a phenyl group or an unsubstituted C7-C30 fused aryl group, but does not contain a fluorenyl group;

[0057] L1 and L2 are each independently a directly bonded, substituted or unsubstituted C6-C50 arylene, or a substituted or unsubstituted C2-C50 heteroarylene;

[0058] R1 to R4 are each independently hydrogen, deuterium, halogen, nitro, nitrile, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C1-C30 mercapto, substituted or unsubstituted C3-C30 silyl, substituted or unsubstituted C6-C50 aryl, or substituted or unsubstituted C2-C50 heteroaryl.

[0059] l is an integer from 0 to 4; and,

[0060] m is an integer from 0 to 4.

[0061] At this time, R1 and R2 can each be independently a substituted or unsubstituted C1-C30 alkyl, a substituted or unsubstituted C6-C50 aryl, or a substituted or unsubstituted C2-C50 heteroaryl.

[0062] In the above content, the substituent during substitution can be one of the substituents mentioned above, specifically methyl or phenyl, but is not limited to this.

[0063] Furthermore, R3 is preferably hydrogen, deuterium, halogen, nitro, nitrile, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C1-C30 mercapto, substituted or unsubstituted C3-C30 silyl, or substituted or unsubstituted C6-C50 aryl.

[0064] As described above, the compound represented by Formula 1 according to the present invention has a structure in which an amino group is attached to the 1, 3, or 4 positions of a fluorene group via a linker containing a meta-aryl group (specifically, a 1,3-phenylene). Therefore, it is possible to achieve a deeper highest occupied molecular orbital (HOMO) beneficial to the luminescent auxiliary layer and a higher lowest occupied molecular orbital (LUMO) beneficial to electron interception. In particular, when R1 and R2 are methyl or phenyl, the decrease in Hall mobility can be suppressed by minimizing the volume characteristics of the fluorene group, thus effectively improving the driving voltage. Furthermore, because thin film deposition can be performed at lower temperatures, its thermal stability is excellent.

[0065] Specifically, the above chemical formula 1 can be represented by the following chemical formula 2:

[0066] <Chemical Formula 2>

[0067]

[0068] The definitions of Ar1, Ar2, L1, L2, R3, R4, l, and m are the same as those in chemical formula 1 above.

[0069] R1 and R2 are each independently a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C6-C50 aryl group, or a substituted or unsubstituted C2-C50 heteroaryl group.

[0070] L1 connects to any of the * positions.

[0071] As described above, the compound represented by chemical formula 2 according to the present invention has a structure in which an amino group is bonded to the 3rd or 4th position of a fluorenyl group and R1 and R2 are defined as alkyl, aryl or heteroaryl. By minimizing molecular warpage, it can form a deeper highest occupied molecular orbital (HOMO) while having a higher lowest occupied molecular orbital (LUMO). Therefore, when it is applied to a light-emitting auxiliary layer, the electronic balance within the light-emitting layer can be easily adjusted, thereby improving efficiency and lifespan.

[0072] Furthermore, the above chemical formula 1 can be represented by the following chemical formula 3:

[0073] <Chemical Formula 3>

[0074]

[0075] In the above chemical formula 3,

[0076] The definitions of Ar1, Ar2, L1, R3, R4, l, and m are the same as those in chemical formula 1 above.

[0077] R1 and R2 are each independently a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C6-C50 aryl group, or a substituted or unsubstituted C2-C50 heteroaryl group.

[0078] L3 is a directly bonded, substituted or unsubstituted C6-C50 arylene, or a substituted or unsubstituted C2-C50 heteroarylene.

[0079] L1 connects to any of the * positions.

[0080] As described above, the compound represented by Formula 3 according to the present invention can maintain a high T1 while forming a deeper least occupied molecular orbital (LUMO) by defining the linker (L2) directly bound to the amine group as a structure containing a phenylene group.

[0081] Specifically, the above chemical formula 1 can be represented by the following chemical formula 4:

[0082] <Chemical Formula 4>

[0083]

[0084] In the above chemical formula 4,

[0085] The definitions of Ar1, Ar2, L1, R3, and R4 are the same as those in Chemical Formula 1 above.

[0086] R1 and R2 are each independently a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C6-C50 aryl group, or a substituted or unsubstituted C2-C50 heteroaryl group.

[0087] L3 is a directly bonded, substituted or unsubstituted C6-C50 arylene, or a substituted or unsubstituted C2-C50 heteroarylene.

[0088] L1 connects to any of the * positions.

[0089] As described above, the compound represented by the above chemical formula 4 according to the present invention has a structure in which the linker directly bound to the amine group is defined as p-phenylene (1,4-phenylene), thus its molecules have excellent thin-film arrangement and therefore have a fast Hall mobility, thereby enabling a lower driving voltage.

[0090] Furthermore, the aforementioned chemical formula 1 can be represented by the following chemical formula 5 or chemical formula 6:

[0091] <Chemical Formula 5>

[0092]

[0093] <Chemical Formula 6>

[0094]

[0095] In the aforementioned chemical formulas 5 and 6,

[0096] The definitions of Ar1 and Ar2 are the same as those in Chemical Formula 1 above.

[0097] R1 and R2 are each independently a substituted or unsubstituted C1-C6 alkyl, a substituted or unsubstituted C6-C50 aryl, or a substituted or unsubstituted C2-C50 heteroaryl.

[0098] o and p are each independently 0 or 1.

[0099] The compound represented by Formula 5 according to the present invention has a structure in which L1 and L3 are directly bonded or more than one phenylene group bonded to the 3 position of the fluorene group. Therefore, excellent thin-film alignment of the molecule can be ensured and mobility can be effectively improved by minimizing the warpage of the fluorene group.

[0100] Furthermore, the compound represented by chemical formula 6 according to the present invention has a structure that defines L1 and L3 as directly bonded or one or more phenylene groups and defines the binding position of the fluorene group as position 4, which can maintain a deeper highest occupied molecular orbital (HOMO) and a higher lowest occupied molecular orbital (LUMO) and T1. Therefore, excitons can be easily formed in the luminescent layer and the decrease in mobility can be minimized, thereby maintaining the driving voltage more effectively and improving efficiency.

[0101] Furthermore, in the case that the terminal aryl group Ar2 of the amine group is phenyl in the above-mentioned chemical formula 5 or chemical formula 6, a high T1 can be maintained while forming a high least occupied molecular orbital (LUMO), thus maintaining a high efficiency of the organic light-emitting element and achieving excellent driving improvement.

[0102] Furthermore, in any of the chemical formulas 1 to 6 mentioned above,

[0103] The Ar2 mentioned above can be phenyl or naphthyl. The compounds of the present invention that meet the above conditions can not only achieve deeper highest occupied molecular orbitals (HOMOs), but also form thin films at lower deposition temperatures, thus exhibiting excellent thermal stability improvement.

[0104] In addition, the Ar1 mentioned above can be phenyl, biphenyl, terphenyl, naphthyl, phenanthrene or triphenylene, and may contain o-phenylene (1,2-phenylene) or m-phenylene (1,3-phenylene).

[0105] Specifically, the Ar1 mentioned above can be phenyl, biphenyl, or a combination thereof.

[0106] As an example, the Ar1 mentioned above can be any of the substituents represented by the following structures A-1 to A-13:

[0107]

[0108] According to the present invention, the compound represented by any one of chemical formulas 1 to 6, as Ar1, contains phenyl, biphenyl, or a combination thereof, thus ensuring excellent thin-film alignment of molecules and effectively improving Hall mobility by minimizing the volume characteristics of terminal extension, thereby improving service life by driving and suppressing decay phenomena.

[0109] At the same time, R1 and R2 can each be methyl or phenyl independently.

[0110] The aforementioned R3 and R4 can each be hydrogen, deuterium, methyl, phenyl, biphenyl, or naphthyl.

[0111] The compounds of the present invention that meet the above conditions can suppress the decrease in Hall mobility by minimizing the volume characteristics of the fluorene group, thus not only effectively improving the driving voltage, but also improving thermal stability due to the lower deposition temperature.

[0112] The following compounds are specific examples of compounds according to the present invention. These examples are merely illustrative and are not intended to limit the scope of the invention.

[0113]

[0114]

[0115]

[0116]

[0117]

[0118]

[0119]

[0120]

[0121]

[0122]

[0123]

[0124]

[0125]

[0126]

[0127]

[0128]

[0129]

[0130]

[0131]

[0132]

[0133]

[0134]

[0135]

[0136]

[0137]

[0138]

[0139]

[0140]

[0141]

[0142]

[0143] Furthermore, another embodiment of the present invention provides an organic light-emitting element comprising a compound represented by the above-described chemical formula 1. The organic light-emitting element may include one or more organic layers containing the compound according to the present invention between the first electrode and the second electrode.

[0144] In one embodiment of the present invention, the aforementioned organic layer may be one or more of a hole injection layer, a hole transport layer, and a light-emitting auxiliary layer, for example, it may be a light-emitting auxiliary layer, but it is not limited thereto. In this case, the compound of the present invention may be used alone or in combination with known organic light-emitting compounds.

[0145] In this invention, the light-emitting auxiliary layer refers to the layer formed between the hole transport layer and the light-emitting layer. The hole transport layer can be referred to as such as the second hole transport layer or the third hole transport layer, depending on its number.

[0146] Specifically, the organic light-emitting element of the present invention may include one or more organic layers such as a hole injection layer (HIL), a hole transport layer (HTL), an emissive layer (EML), an electron transport layer (ETL), and an electron injection layer (EIL) between the first electrode and the second electrode.

[0147] Figure 1 This is a schematic diagram illustrating the structure of an organic light-emitting element according to an embodiment of the present invention.

[0148] like Figure 1 As shown, the organic light-emitting element of the present invention can be manufactured by stacking the first electrode (hole injection electrode) 1000, hole injection layer 200, hole transport layer 300, light-emitting layer 400, electron transport layer 500, electron injection layer 600 and second electrode (electron injection electrode) 2000 sequentially from bottom to top on the upper part of the substrate 100.

[0149] In addition, although not shown in the figure, a hole blocking layer (not shown) may be included between the light-emitting layer 400 and the electron transport layer 500, and an electron blocking layer (not shown) may be included between the hole transport layer 300 and the light-emitting layer 400.

[0150] Furthermore, a cover layer (not shown) may be included between the substrate 100 and the first electrode 1000, and a cover layer (not shown) may also be included on the upper part of the second electrode 2000.

[0151] Figure 1 The substrate 100 can be used as a substrate in organic light-emitting elements, especially a transparent glass substrate or a flexible plastic substrate with excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of handling and water resistance.

[0152] The first electrode 1000 is used as the anode for injecting holes in the organic light-emitting element. To achieve hole injection, a material with the lowest possible work function is used, and transparent materials such as indium tin oxide (ITO), indium zinc oxide (IZO), and graphene can be used.

[0153] Above the first electrode, a hole injection layer 200 can be formed by depositing a hole injection layer material using methods such as vacuum deposition, spin coating, casting, or the Langmuir-Blodgett (LB) method. When forming the hole injection layer using vacuum deposition, the deposition conditions will vary depending on the compound used as the hole injection layer material, the desired hole injection layer structure, and its thermal properties. Typically, deposition temperatures ranging from 50 to 500°C and 10... -8 Up to 10 -3 The vacuum level of the Torr is 0.01 to... deposition rate per second and Appropriate selection should be made within the range of layer thickness up to 5 μm.

[0154] Next, on top of the aforementioned hole injection layer 200, a hole transport layer 300 can be formed by depositing a hole transport layer material using methods such as vacuum deposition, spin coating, casting, or the Langmuir-Brønder (LB) method. When forming the hole transport layer using the aforementioned vacuum deposition method, the deposition conditions will vary depending on the compound used, but are generally preferably selected within a range of conditions almost identical to those used for forming the hole injection layer. There can be more than one hole transport layer; for example, it can be two layers, such as a first hole transport layer and a second hole transport layer (luminescent auxiliary layer). At least one of the aforementioned first hole transport layer and second hole transport layer can include a compound of Chemical Formula 1 according to the present invention.

[0155] Next, on top of the aforementioned hole transport layer or luminescent auxiliary layer, a luminescent layer 400 can be formed by depositing a luminescent layer material using methods such as vacuum deposition, spin coating, casting, or the Langmuir-Brønder (LB) method. When forming the luminescent layer using the aforementioned vacuum deposition method, the deposition conditions will vary depending on the compound used, but it is generally preferable to select conditions within a range almost identical to those used for forming the hole injection layer. Furthermore, known compounds can be used as the main agent or dopant as the luminescent layer material.

[0156] Furthermore, when phosphorescent dopants are used simultaneously in the emitting layer, to prevent triplet excitons or holes from diffusing into the electron transport layer, a stacked hole-blocking material (HBL) can be added using vacuum deposition or spin coating. In this case, the hole-blocking material used is not particularly limited, and any known material used as a hole-blocking material can be selected. For example, oxadiazole derivatives or benzotriazole derivatives, o-diazepinel derivatives, or hole-blocking materials described in Japanese Patent Application Publication No. 11-329734 (A1) can be used. Among these, the most representative include Balq (bis(8-hydroxy-2-methylquinoline)-(4-phenylphenoxy)aluminum) and phenanthrolines (e.g., UDC's BCP).

[0157] An electron transport layer 500 will be formed on top of the light-emitting layer 400 formed as described above. This electron transport layer can be formed by methods such as vacuum deposition, spin coating, or casting. Furthermore, the deposition conditions of the electron transport layer will vary depending on the compound used, but it is generally preferable to select conditions within a range that are almost identical to those for the formation of the hole injection layer.

[0158] Next, an electron injection layer 600 can be formed by depositing an electron injection layer material on top of the electron transport layer 500. At this time, the electron injection layer can be formed using a common electron injection layer material through methods such as vacuum deposition, spin coating, or casting.

[0159] The hole injection layer 200, hole transport layer 300, light emission layer 400, and electron transport layer 500 of the above-mentioned organic light-emitting element may use compounds according to the present invention or substances as described in Table 1 below, or may use compounds according to the present invention and known substances simultaneously.

[0160] Table 1

[0161]

[0162] Above the electron-injected layer 600, a second electrode 2000 can be formed using methods such as vacuum deposition or spin coating. Various metals can be used as the second electrode. Specific examples include materials such as aluminum, gold, and silver.

[0163] As an organic light-emitting element according to the present invention, not only can an organic light-emitting element composed of a first electrode (anode), a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, and a second electrode (cathode) be used, but also organic light-emitting elements with various structures can be used, and one or two intermediate layers can be added as needed.

[0164] The thickness of each organic layer formed by the present invention as described above can be adjusted according to the required degree, specifically from 10 to 1000 nm, and more specifically from 30 to 100 nm.

[0165] Furthermore, the present invention allows for the adjustment of the thickness of an organic layer, comprising a compound represented by the above-described chemical formula 1, at the molecular level, thus providing the advantages of uniform surface and excellent morphological stability.

[0166] Next, the present invention will be described in more detail through examples of the synthesis of compounds according to an embodiment of the present invention and examples of the manufacture of organic light-emitting elements. The following examples are merely illustrative of the present invention, and the scope of the present invention is not limited to the following examples.

[0167] <Manufacturing Example 1> Synthesis of Intermediate Compound IM1

[0168] The intermediate compound IM1 was synthesized according to the following reaction formula.

[0169]

[0170] 200 mL of 1,4-dioxane was added to a round-bottom flask, followed by the dissolution of 10.1 g of (9,9-diphenyl-9H-fluoren-3-yl)boronic acid, 10.0 g of 4'-bromo-3-iodo-1,1'-biphenyl, and then 40 mL of K₂CO₃ (2 M aqueous solution) and 1.0 g of Pd(PPh₃)₄. The mixture was then refluxed with stirring. The extent of the reaction was confirmed by thin-layer chromatography (TLC), and the reaction was terminated after the addition of water. The organic layer was extracted with dichloromethane (MC), filtered under reduced pressure, and recrystallized to obtain 11.0 g of the intermediate compound IM₁ (72% yield).

[0171] <Manufacturing Example 2> Synthesis of intermediate compounds IM2 and IM3

[0172] The same method as in Manufacturing Example 1 described above was used for synthesis, wherein compounds IM2 and IM3 were synthesized using (9,9-diphenyl-9H-fluoren-4-yl)boronic acid and (3-(9,9-diphenyl-9H-fluoren-4-yl)phenyl)boronic acid as starting materials, respectively, as described below.

[0173]

[0174] <Synthetic Example 1> Synthesis of Compound 91

[0175]

[0176] 70 mL of toluene was added to a round-bottom flask, and 3.0 g of the intermediate compound IM1 prepared by Preparation Example 1, 1.0 g of diphenylamine, 0.8 g of t-BuONa, 0.2 g of Pd2(dba)3, and 0.2 mL of (t-Bu)3P were dissolved therein, followed by reflux and stirring. The extent of the reaction was confirmed by thin-layer chromatography (TLC), and the reaction was terminated after the addition of water. The organic layer was extracted with dichloromethane (MC), purified by column chromatography after vacuum filtration, and recrystallized to obtain 2.4 g of compound 91 (yield 69%).

[0177] m / z: 637.28 (100.0%), 638.28 (53.4%), 639.28 (14.0%), 640.29 (2.4%)

[0178] <Synthetic Example 2> Synthesis of Compound 187

[0179]

[0180] The same procedure as in Synthesis Example 1 was followed, except that intermediate compound IM1 was synthesized by replacing intermediate compound IM1 with intermediate compound IM2 produced by Manufacturing Example 2 (yield 67%).

[0181] m / z: 637.28 (100.0%), 638.28 (53.4%), 639.28 (14.0%), 640.29 (2.4%)

[0182] <Synthetic Example 3> Synthesis of Compound 188

[0183]

[0184] Compound 188 was synthesized in 70% yield by using intermediate compound IM2 produced by manufacturing example 2 and N-phenyl-[1,1'-biphenyl]-4-amine instead of intermediate compound IM1 and diphenylamine.

[0185] m / z: 713.31 (100.0%), 714.31 (60.3%), 715.31 (17.6%), 716.32 (3.4%)

[0186] <Synthetic Example 4> Synthesis of Compound 190

[0187]

[0188] Compound 190 was synthesized in 65% yield by using intermediate compound IM2 produced by manufacturing example 2 and N-phenyl-[1,1'-biphenyl]-2-amine instead of intermediate compound IM1 and diphenylamine.

[0189] m / z: 713.31 (100.0%), 714.31 (60.3%), 715.31 (17.6%), 716.32 (3.4%)

[0190] <Synthetic Example 5> Synthesis of Compound 238

[0191]

[0192] The same procedure as in Synthesis Example 1 was followed, except that intermediate compound IM1 was synthesized by replacing intermediate compound IM1 with intermediate compound IM3 produced by Manufacturing Example 3 (yield 63%).

[0193] m / z: 713.31 (100.0%), 714.31 (60.3%), 715.31 (17.6%), 716.32 (3.4%)

[0194] Manufacturing of organic light-emitting elements

[0195] The organic light-emitting element of the present invention was manufactured using the substances listed in Table 2 below.

[0196] Table 2

[0197]

[0198] <Example 1>

[0199] Using distilled water to coat with A glass substrate with a thick indium tin oxide (ITO) thin film is ultrasonically cleaned. After washing with distilled water, it is ultrasonically cleaned and dried using solvents such as isopropanol, acetone, and methanol. Next, it is transferred to a plasma cleaner where oxygen plasma is used to clean the substrate for 5 minutes. Then, a thermal evaporator is used to deposit a thin film onto the indium tin oxide (ITO) substrate. HI01 and The HATCN membrane was used as a hole injection layer to form... The HT01 membrane is used as a hole transport layer to form a... After using the film of the compound prepared in Synthesis Example 1 as a light-emitting auxiliary layer, a 3% doped BH01:BD01 was prepared. The film serves as the light-emitting layer. Next, a... After using an ET01:Liq (1:1) film as an electron transport layer, it was fabricated LiF membrane, Organic light-emitting elements are manufactured by encapsulating aluminum (Al) films in a glove box.

[0200] Example 2 to Example 5

[0201] Organic light-emitting elements were manufactured by depositing light-emitting auxiliary layers using the compounds produced by Synthesis Examples 2 to 5, respectively, in the same manner as in Example 1 above.

[0202] Comparative Examples 1 to 6

[0203] Organic light-emitting elements were fabricated by depositing light-emitting auxiliary layers using comparative compounds 1 (Ref. 1) to 6 (Ref. 6) as shown in Table 3 below, respectively.

[0204] Table 3

[0205]

[0206] Performance Evaluation of Organic Light-Emitting Components

[0207] Electrons and holes were injected by applying a voltage to a Kiethley 2400 source measurement unit, and the brightness of the emitted light was measured using a Konica Minolta spectroradiometer (CS-2000). The performance of the organic light-emitting elements of the examples and comparative examples, i.e., the current density and brightness relative to the applied voltage, were evaluated under atmospheric pressure conditions. The results are shown in Table 4.

[0208] Table 4

[0209] Op.V <![CDATA[mA / cm 2 ]]> Cd / A QE (%) CIEx CIEy LT95 Example 1 3.42 10 8.1 6.7 0.139 0.110 163 Example 2 3.45 10 8.5 6.9 0.140 0.109 171 Example 3 3.44 10 8.4 7.5 0.140 0.110 180 Example 4 3.45 10 8.6 7.3 0.142 0.110 175 Example 5 3.45 10 8.7 7.1 0.140 0.109 178 Comparative Example 1 3.46 10 6.5 4.8 0.140 0.111 90 Comparative Example 2 3.48 10 6.8 5.7 0.141 0.109 113 Comparative Example 3 3.50 10 7.0 5.9 0.140 0.110 125 Comparative Example 4 3.54 10 7.2 6.0 0.142 0.110 76 Comparative Example 5 3.70 10 7.4 6.3 0.140 0.110 88 Comparative Example 6 3.51 10 6.9 5.7 0.140 0.110 103

[0210] By comparing the embodiments of the present invention, it can be found that the organic light-emitting elements of the embodiments can not only achieve a lower driving voltage, but also have a very good effect on improving luminous efficiency.

[0211] Specifically, it can be confirmed that the organic light-emitting elements of the above embodiments can achieve lower voltage and higher efficiency compared with Comparative Examples 1 to 3. This is because the compounds of the embodiments used in the light-emitting auxiliary layer have a deeper highest occupied molecular orbital (HOMO) than the compound of Comparative Example 1 in which the linker is introduced into the fluorene group at position 2, and maintain a deeper HOMO and a faster Hall mobility compared with the compounds of Comparative Examples 2 and 3 due to the extension of the meta linker.

[0212] Furthermore, compared to Comparative Example 4, the organic light-emitting element of the embodiments, which includes a compound with an unextended aryl group on the other side of the amine group in the light-emitting auxiliary layer, can maintain a deeper highest occupied molecular orbital (HOMO) while exhibiting a higher lowest occupied molecular orbital (LUMO) and T1. Moreover, it can be confirmed that the compounds of the above embodiments have a better film alignment than the compounds of Comparative Example 5, which contain an extended substituent in the fluorene group, thus improving their Hall mobility. Meanwhile, the compounds of the above embodiments maintain a deeper highest occupied molecular orbital (HOMO) compared to Comparative Example 6, where the aryl group is a methylfluorene group. Therefore, the compounds of the embodiments can more effectively improve Hall mobility compared to the compounds of the comparative examples, while also easily achieving electron interception and exciton movement interception with excellent charge balance within the light-emitting layer. Furthermore, the above compounds can achieve lower driving voltage, higher efficiency, and longer lifespan by suppressing decay phenomena.

Claims

1. A compound represented by the following formula 1: Formula 1 wherein in the above formula 1, Ar1 is a C6 to C50 aryl group substituted with deuterium or a C6 aryl group or unsubstituted, Ar2 is a phenyl group, L1 and L2 are each independently a direct bond or a C6 arylene group, and one or more of L1 and L2 is a C6 arylene group, R1 and R2 are unsubstituted phenyl groups, R3 and R4 are each independently hydrogen or deuterium, 1 is an integer of 0 to 4, and m is an integer of 0 to 4, provided that the following compounds are excluded:

2. The compound according to claim 1, wherein the above formula 1 is a compound represented by the following formula 2: Formula 2 wherein in the above formula 2, the definitions of Ar1, Ar2, L1, L2, R1 to R4, 1 and m are the same as those in the above formula 1, and L1 is attached to any one of the * positions.

3. The compound according to claim 1, wherein the above formula 1 is a compound represented by the following formula 3: Formula 3 wherein in the above formula 3, the definitions of Ar1, Ar2, L1, R1 to R4, 1 and m are the same as those in the above formula 1, L3 is a direct bond, and L1 is attached to any one of the * positions.

4. The compound according to claim 1, wherein the above formula 1 is a compound represented by the following formula 4: Formula 4 wherein in the above formula 4, the definitions of Ar1, Ar2, L1, R1 to R4 are the same as those in the above formula 1, L3 is a direct bond, and L1 is attached to any one of the * positions.

5. The compound according to claim 1, wherein the above formula 1 is a compound represented by the following formula 5 or formula 6: Formula 5 Formula 6 wherein in the above formula 5 and formula 6, the definitions of R1, R2, Ar1 and Ar2 are the same as those in the above formula 1, o is 0 or 1, and p is 0.

6. The compound according to claim 1, wherein Ar1 is a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a phenanthryl group or a triphenylenyl group.

7. The compound according to claim 1, wherein Ar1 is any one of the substituents represented by the following structures A-1 to A-13: Structure A-1 Structure A-2 Structure A-3 Structure A-4 Structure A-5 Structure A-6 Structure A-7 Structure A-8 Structure A-9 Structure A-10 Structure A-11 Structure A-12 Structure A-13 8. The compound according to claim 1, wherein the compound of the above formula 1 is any one of the compounds represented by the following formulas:

9. An organic light emitting element comprising: a first electrode; an organic layer over the first electrode; and a second electrode over the organic layer, wherein the organic layer comprises the compound according to any one of claims 1 to 8.

10. The organic light emitting element according to claim 9, wherein the organic layer is any one or more of a hole injecting layer, a hole transporting layer and a light emitting auxiliary layer.

11. The organic light emitting element according to claim 10, wherein the organic layer is a light emitting auxiliary layer between a hole transporting layer and a light emitting layer. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 9. An organic light emitting element characterized by comprising: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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