Novel compound and organic light-emitting element comprising the same

Abstract

The present invention provides a compound represented by the following Chemical Formula 1 and an organic light-emitting element comprising the compound: #imgabs0#.

Description

Technical Field

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

[0002] Recently, self-luminous organic light-emitting elements that can be driven at low voltage have attracted much attention as the next generation of display elements due to their advantages over the mainstream flat-panel display elements, namely liquid crystal displays (LCDs). These include superior viewing angles and contrast ratios, the absence of a backlight, the ability to be lightweight and thinner, low power consumption, and a wide range of color reproduction.

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

[0004] In addition, the luminescent materials can be divided into polymers and single molecules according to their molecular weight, and can be divided into fluorescent materials originating from the singlet excited state of electrons, phosphorescent materials originating from the triplet excited state of electrons, and delayed fluorescent materials originating from the movement of electrons from the triplet excited state to the singlet excited state according to their luminescent mechanism. The luminescent materials can be divided into blue, green, yellow required to achieve a natural color better than red luminescent materials, and vermilion luminescent materials according to their luminescent colors.

[0005] Furthermore, to improve color purity and luminescence efficiency through energy transfer, a host / dopant type of material can also be used as the luminescent material. The principle is that by incorporating a small amount of a luminescent material (a dopant) with a smaller energy bandgap than the host into the light-emitting layer, excitons generated in the host can be transferred to the dopant, emitting light. This principle allows for the production of light of a desired wavelength, depending on the type of host and dopant.

[0006] Currently, a variety of compounds are known as materials suitable for use in organic light-emitting diodes. However, organic light-emitting diodes using these known materials suffer from issues such as high driving voltage, low efficiency, and short lifespan, necessitating the development of new materials. Consequently, efforts have been underway to utilize materials with superior properties to develop organic light-emitting diodes that achieve low-voltage operation, high brightness, and long lifespans. Summary of the Invention

[0007] The object of the present invention is to provide a novel compound and an organic light-emitting element that form a deeper highest occupied molecular orbital (HOMO) while having a higher lowest occupied molecular orbital (LUMO) and T1, thereby easily achieving electron interception and exciton migration interception and having excellent charge balance in the light-emitting layer.

[0008] In addition, the purpose of the present invention is to provide a new compound and organic light-emitting element that has faster Hall mobility and can ensure excellent molecular arrangement when forming a thin film due to improved π conjugation, thereby achieving lower driving voltage and high efficiency, and can achieve a long service life by suppressing the attenuation phenomenon.

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

[0010] Next, the above-mentioned issues and additional issues will be described in detail.

[0011] As a means of solving the above-mentioned problems,

[0012] One embodiment of the present invention provides a compound represented by the following Chemical Formula 1.

[0013] <Chemical Formula 1>

[0014]

[0015] In the chemical formula 1,

[0016] Ar1 and Ar2 are each independently a phenyl group or an unsubstituted C7-C30 fused aryl group;

[0017] L is a C10-50 arylene group or a C10-50 heteroarylene group, and does not include a fluorenyl group;

[0018] R1 to R3 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;

[0019] l, m and n are each independently an integer from 0 to 4.

[0020] Furthermore, as one embodiment of the present invention, an organic light-emitting element is provided, comprising:

[0021] 1st electrode;

[0022] an organic layer located on the first electrode; and

[0023] a second electrode, located on the organic layer;

[0024] The organic layer includes the compound described above.

[0025] The organic layer may be one or more of a hole injection layer, a hole transport layer, and a luminescence auxiliary layer, and specifically, may be a luminescence auxiliary layer located between the hole transport layer and the luminescence layer.

[0026] The compound according to the present invention has an amine structure containing a spirobifluorenyl group and a terminal aromatic group (Ar1 and Ar2 in Chemical Formula 1) composed of a phenyl group or a fused aromatic group. Since a deeper highest occupied molecular orbital (HOMO) can be formed while maintaining a higher lowest occupied molecular orbital (LUMO), a lower voltage of an organic light-emitting element can be achieved, thereby providing a high-efficiency element.

[0027] In addition, the compound can increase π-conjugation through a linking group L with more than 10 carbon atoms, thereby having a faster Hall mobility, and can ensure excellent molecular arrangement when forming a thin film, thereby achieving a lower driving voltage and high efficiency, and can also achieve an organic light-emitting element with a long service life by suppressing the attenuation phenomenon.

[0028] Furthermore, since the unextended aromatic groups of the spirobifluorenyl group and the amino group have higher lowest occupied molecular orbitals (LUMO) and T1, the effect of intercepting the movement of excitons in the light-emitting layer can be maximized, thereby further improving the efficiency of the organic light-emitting device.

[0029] Furthermore, since the compound can have a high glass transition temperature (Tg) by extending the spirobifluorene group and the linker L, an organic light-emitting element with excellent driving stability can be realized by preventing recrystallization of the thin film.

[0030] Next, the above-mentioned effects and additional effects will be described in detail. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] 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.

[0032]

Explanation of symbols

[0033] 100: Substrate

[0034] 200: Hole injection layer

[0035] 300: Hole transport layer

[0036] 400: Luminous layer

[0037] 500: electron transport layer

[0038] 600: electron injection layer

[0039] 1000: 1st electrode (anode)

[0040] 2000: Second electrode (cathode) DETAILED DESCRIPTION

[0041] Before describing the present invention in detail, it should be understood that the terms used in this specification are intended only to describe specific embodiments and are not intended to limit the scope of the present invention, which is to be determined solely by the appended claims. Unless otherwise expressly stated, all technical and scientific terms used in this specification have the same meanings as those commonly understood by persons of ordinary skill in the art.

[0042] Throughout this specification and claims, unless expressly stated otherwise, terms such as comprise, comprise, or comprising merely indicate the inclusion of the stated item, step, or series of items and steps, and do not preclude any other item, step, or series of items or steps.

[0043] Throughout the present specification and claims, the term "aryl" refers to groups such as phenyl, benzyl, naphthyl, biphenyl, terphenyl, fluorenyl, phenanthrenyl, triphenylene, phenylene, Benzotriphenylene, benzophenone, fluoranthene, benzofluorenyl, benzotriphenylene, benzo The term "heteroaryl" refers to a C5-50 aromatic hydrocarbon ring containing an aromatic ring such as pyrrolyl, pyrazinyl, pyridyl, indolyl, isoindolyl, furyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, benzothiophenyl, dibenzothiophenyl, quinolyl, isoquinolyl, quinoxalinyl, carbazolyl, phenanthridinyl, acridinyl, phenanthrolinyl, thienyl, and a group consisting of pyridine, pyrazine, pyrimidine, pyridazine, triazine, indole, quinoline, acridine, pyrrolidine, dibenzothiophenyl, ... Alkane, piperidine, morpholine, piperazine, carbazole, furan, thiophene, Azoles, oxadiazole, benzo The heterocyclic group is a C2-50 aromatic ring containing at least one hetero element, which is composed of oxazole, benzofuran, thiazole, thiadiazole, benzothiazole, benzothiophene, benzotriazole, imidazole, benzimidazole, pyran, dibenzofuran, etc.

[0044] In addition, Ar in the chemical formula x (wherein x is an integer) unless otherwise specifically defined, represents a substituted or unsubstituted C6-C50 aryl group, or a substituted or unsubstituted C2-C50 heteroaryl group, L x (wherein x is an integer) unless otherwise specifically defined, represents a directly bonded, substituted or unsubstituted C6-C50 arylene group, or a substituted or unsubstituted C2-C50 heteroarylene group, R x (wherein x is an integer) unless explicitly defined otherwise, represents 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.

[0045] Throughout the present specification and claims, the term "substituted or unsubstituted" may refer to a group substituted with deuterium, halogen, amino, cyano, nitrile, nitro, nitroso, sulfamoyl, isothiocyanate, thiocyanate, carboxyl, or C1-C30 alkyl, C1-C30 alkylsulfinyl, C1-C30 alkylsulfonyl, C1-C30 alkylsulfanyl, C1-C12 fluoroalkyl, C2-C30 alkenyl, C1-C30 alkoxy, C1-C12 alkylsulfonyl ... The alkyl group may be substituted or unsubstituted with one or more groups selected from the group consisting of a C1-C12 N-alkylamino group, a C2-C20 N,N-dialkylamino group, a substituted or unsubstituted C1-C30 mercapto group, a C1-C6 N-alkylsulfamoyl group, a C2-C12 N,N-dialkylsulfamoyl group, a C3-C30 silyl group, a C3-C20 cycloalkyl group, a C3-C20 heterocycloalkyl group, a C6-C50 aryl group, and a C3-C50 heteroaryl group. In addition, throughout the specification of this application, unless otherwise specified, the same symbols have the same meaning.

[0046] In addition, unless otherwise explicitly stated to the contrary, the various embodiments of the present invention may be combined with other embodiments. Next, the embodiments of the present invention and their effects will be described.

[0047] Next, the present invention will be described in detail.

[0048] The compound according to the present invention is represented by Chemical Formula 1 below.

[0049] <Chemical Formula 1>

[0050]

[0051] In the chemical formula 1,

[0052] Ar1 and Ar2 are each independently a phenyl group or an unsubstituted C7-C30 fused aryl group;

[0053] L is a C10-50 arylene group or a C10-50 heteroarylene group, and does not include a fluorenyl group;

[0054] R1 to R3 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;

[0055] l, m and n are each independently an integer from 0 to 4.

[0056] As described above, the compound represented by Chemical Formula 1 according to the present invention has an amine structure containing a spirobifluorenyl group and a terminal aromatic group (Ar1 and Ar2 of Chemical Formula 1) composed of a phenyl group or a fused aromatic group. Since a deeper highest occupied molecular orbital (HOMO) suitable for a light-emitting auxiliary layer can be formed while maintaining a higher lowest occupied molecular orbital (LUMO) that is easy to intercept electrons, a lower voltage of the organic light-emitting element can be achieved.

[0057] Specifically, the chemical formula 1 can be represented by the following chemical formula 2:

[0058] <Chemical Formula 2>

[0059]

[0060] In the chemical formula 2,

[0061] The definitions of Ar1, Ar2, R1 to R3, l, m and n are the same as those in Chemical Formula 1.

[0062] R4 and R5 are each independently hydrogen, deuterium, halogen, nitro, nitrile, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C6-C50 aryl, or substituted or unsubstituted C2-C50 heteroaryl,

[0063] o is an integer from 1 to 5.

[0064] Because the compound represented by Chemical Formula 2 contains two or more substituted or unsubstituted phenylene groups as the linker L, it can ensure excellent molecular alignment during thin film formation, thereby improving Hall mobility, and can easily intercept electrons by forming a higher lowest occupied molecular orbital (LUMO).

[0065] In particular, when o is 1 or 2, a higher glass transition temperature (Tg) of the compound can be achieved, and thus the driving stability of the device can be effectively improved.

[0066] In addition, the chemical formula 1 can be represented by the following chemical formula 3:

[0067] <Chemical Formula 3>

[0068]

[0069] In the chemical formula 3,

[0070] The definitions of Ar1, Ar2, R1 to R3, l, m and n are the same as those in Chemical Formula 1.

[0071] R4 and R5 are each independently hydrogen, deuterium, halogen, nitro, nitrile, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C6-C50 aryl, or substituted or unsubstituted C2-C50 heteroaryl,

[0072] o is an integer from 1 to 5,

[0073] The phenylene group is linked to any one of the * positions of the spirobifluorenyl group.

[0074] Since the compound represented by Chemical Formula 3 introduces a linker comprising two or more substituted or unsubstituted phenylene groups into the 3rd or 4th position of the spirobifluorenyl group, a deeper highest occupied molecular orbital (HOMO) can be formed and a faster Hall mobility can be achieved.

[0075] In addition, the chemical formula 3 can be represented by the following chemical formula 3-1 or chemical formula 3-2:

[0076] <Chemical Formula 3-1>

[0077]

[0078] <Chemical Formula 3-2>

[0079]

[0080] In the chemical formula 3-1 and the chemical formula 3-2,

[0081] The definitions of Ar1, Ar2, R1 to R3, l, m and n are the same as those in Chemical Formula 1.

[0082] R4 and R5 are each independently hydrogen, deuterium, halogen, nitro, nitrile, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C6-C50 aryl, or substituted or unsubstituted C2-C50 heteroaryl,

[0083] o is an integer from 1 to 5.

[0084] The compounds represented by Chemical Formula 3-1 and Chemical Formula 3-2 have a structure in which a linker L including two or more substituted or unsubstituted phenylene groups is connected to the 3rd or 4th position of the spirobifluorenyl group.

[0085] In this case, the compound represented by Chemical Formula 3-1 is introduced as a linker L into position 3 of the spirobifluorenyl group. In this case, a faster Hall mobility can be achieved, thereby further reducing the driving voltage of the organic light-emitting device.

[0086] In addition, the compound represented by Chemical Formula 3-2 is introduced as a linker L into position 4 of the spirobifluorenyl group. In this case, a deeper highest occupied molecular orbital (HOMO) can be formed, thereby effectively improving the efficiency of the organic light-emitting device.

[0087] More specifically, the chemical formula 1 can be represented by the following chemical formula 4 or chemical formula 5:

[0088] <Chemical Formula 4>

[0089]

[0090] <Chemical Formula 5>

[0091]

[0092] In the chemical formula 4 and the chemical formula 5,

[0093] The definitions of Ar1, Ar2, R1 to R3 are the same as those in Chemical Formula 1.

[0094] R4 and R5 are each independently hydrogen, deuterium, halogen, nitro, nitrile, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C6-C50 aryl, or substituted or unsubstituted C2-C50 heteroaryl,

[0095] o is an integer from 1 to 5,

[0096] The phenylene group is linked to any one of the * positions of the spirobifluorenyl group.

[0097] Specifically, R4 and R5 can each independently be hydrogen or phenyl.

[0098] The compounds represented by Chemical Formula 4 and Chemical Formula 5 have a structure in which a linker L including two or more substituted or unsubstituted phenylene groups is connected to the 3rd or 4th position of the spirobifluorenyl group.

[0099] In particular, in the case of the compound represented by Chemical Formula 4, the phenylene group directly bonded to the amine group in the phenylene group of the linker is a p-phenylene (1,4-phenylene) group. In this case, a faster Hall mobility can be achieved, thereby improving the driving performance of the organic light-emitting element while suppressing attenuation, thereby extending the service life of the element.

[0100] In addition, the compound represented by Chemical Formula 5 is an o-phenylene (1,2-phenylene) group in the phenylene group directly bonded to the amine group. In this case, the highest occupied molecular orbital (HOMO) level can be further reduced while achieving a higher lowest occupied molecular orbital (LUMO), thereby improving charge balance within the light-emitting layer and device efficiency.

[0101] More specifically, in the chemical formula 4, One or more of o-phenylene (1,2-phenylene) and m-phenylene (1,3-phenylene) may be contained, thereby forming a higher highest occupied molecular orbital (HOMO) and effectively improving efficiency.

[0102] Furthermore, in the chemical formula 5, It may contain p-phenylene (1,4-phenylene) or may consist of only p-phenylene in some cases. This can minimize molecular distortion and effectively improve mobility.

[0103] In addition, in any one of Chemical Formulae 1 to 5, R1 to R3 may each independently be hydrogen or a phenyl group.

[0104] When the terminal substituents R1 to R3 introduced into the spirobifluorenyl group are hydrogen or phenyl groups, the volume characteristics of the compound can be minimized, thereby more effectively improving the driving voltage of the device. In particular, when R1 to R3 are all hydrogen, this effect can be maximized.

[0105] Meanwhile, in any one of Chemical Formulae 2 to 5, R1 to R5 may each independently be hydrogen or a phenyl group, more specifically a phenyl group.

[0106] Furthermore, Ar1 and Ar2 may each independently be a phenyl group, a naphthyl group, a phenanthrenyl group or a triphenylene group, and specifically a phenyl group.

[0107] In the above case, a lower highest occupied molecular orbital (HOMO) can be formed, and at the same time, the decrease in Hall mobility can be prevented by minimizing the volume characteristics of the compound, and a higher lowest occupied molecular orbital (LUMO) and T1 can be maintained, thereby improving the driving efficiency of the element.

[0108] Meanwhile, the linker (L in Chemical Formula 1) connecting the spirobifluorenyl group and the amino group N may include a biphenylene group or a terphenylene group. As an example, it may include any one of the structures represented by A-1 to A-23 below:

[0109]

[0110]

[0111] As described above, when the linking group connecting the spirobifluorenyl group and the amino group N (L in Chemical Formula 1) is a biphenylene group or a terphenylene group as shown in the structures represented by A-1 to A-23, a lower highest occupied molecular orbital (HOMO) and a higher highest occupied molecular orbital (LUMO) as well as T1 can be achieved, thereby effectively improving the efficiency of the device and significantly reducing the deposition temperature during thin film formation, thereby enhancing the thermal stability of the device.

[0112] At the same time, when the linking groups (L in Chemical Formula 1) shown as A-2 to A-6 and A-8 to A-23 include one or more m-phenylene (1,3-phenylene) or o-phenylene (1,2-phenylene), a higher lowest occupied molecular orbital (LUMO) and T1 can be formed while having a deeper highest occupied molecular orbital (HOMO), thereby effectively improving efficiency and effectively reducing the deposition temperature, thereby ensuring excellent thermal stability.

[0113] The following compounds are specific examples of the compounds according to the present invention. The following examples are merely illustrative for illustrating the present invention, and the present invention is not limited thereby.

[0114]

[0115]

[0116]

[0117]

[0118]

[0119]

[0120]

[0121]

[0122]

[0123]

[0124]

[0125]

[0126]

[0127]

[0128]

[0129]

[0130]

[0131]

[0132]

[0133]

[0134] Furthermore, another embodiment of the present invention provides an organic light-emitting device including the compound represented by Chemical Formula 1. The organic light-emitting device may include one or more organic layers containing the compound according to the present invention between a first electrode and a second electrode.

[0135] In one embodiment of the present invention, the organic layer may be one or more of a hole injection layer, a hole transport layer, and a luminescence-assisting layer, for example, but not limited to, a luminescence-assisting layer. In this case, the compound of the present invention may be used alone or in combination with a known organic light-emitting compound.

[0136] In the present invention, the luminescence-assisting layer refers to a layer formed between the hole transport layer and the luminescent layer. The hole transport layer may be referred to as the second hole transport layer or the third hole transport layer, depending on the number of the hole transport layer.

[0137] 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), a light-emitting layer (EML), an electron transport layer (ETL) and an electron injection layer (EIL) between the first electrode and the second electrode.

[0138] Figure 1 This is a schematic diagram illustrating the structure of an organic light-emitting element according to an embodiment of the present invention.

[0139] 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, the hole injection layer 200, the hole transport layer 300, the light-emitting layer 400, the electron transport layer 500, the electron injection layer 600 and the second electrode (electron injection electrode) 2000 in the order from bottom to top on the upper part of the substrate 100.

[0140] Although not shown, 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 .

[0141] 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 be included on the upper portion of the second electrode 2000 .

[0142] Figure 1 The middle substrate 100 may be a substrate used in an organic light emitting element, and in particular, a transparent glass substrate or a flexible plastic substrate having excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and waterproofness.

[0143] The first electrode 1000 serves as an anode for injecting holes into the organic light-emitting element. To achieve hole injection, a material with the lowest possible work function is used, such as transparent materials such as indium tin oxide (ITO), indium zinc oxide (IZO), and graphene.

[0144] On the upper portion of the first electrode, a hole injection layer material can be deposited by a method such as vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) method to form a hole injection layer 200. When forming the hole injection layer by vacuum deposition, the deposition conditions vary depending on the compound used as the material of the hole injection layer, the desired structure of the hole injection layer, and the thermal properties. Generally, the deposition temperature can be 50 to 500°C, 10 -8 to 10 -3Torr vacuum degree, 0.01 to The deposition rate and The layer thickness is appropriately selected within a range of up to 5 μm.

[0145] Next, on the upper part of the hole injection layer 200, a hole transport layer material can be deposited by a vacuum deposition method, a spin coating method, a casting method, a Langmuir-Brødgette (LB) method, etc. to form a hole transport layer 300. When the hole transport layer is formed by the vacuum deposition method, the deposition conditions will vary depending on the compound used, but it is usually appropriate to select a condition that is almost the same as that for the formation of the hole injection layer. The hole transport layer can be more than one, for example, it can be two layers such as a first hole transport layer and a second hole transport layer (luminescence auxiliary layer). At least one of the first hole transport layer and the second hole transport layer may contain a compound according to Chemical Formula 1 of the present invention.

[0146] Next, on top of the hole transport layer or the light-emitting auxiliary layer, a light-emitting layer material can be deposited by a method such as vacuum deposition, spin coating, casting, or Langmuir-Brøgeta (LB) method to form a light-emitting layer 400. When forming the light-emitting layer by the vacuum deposition method, the deposition conditions will vary depending on the compound used, but it is generally preferable to select conditions within a range that is almost the same as those for forming the hole injection layer. In addition, as the light-emitting layer material, a known compound can be used as a main agent or a dopant.

[0147] In addition, when a phosphorescent dopant is used in the light-emitting layer, in order to prevent triplet excitons or holes from diffusing to the electron transport layer, a stacked hole blocking material (HBL) can be added by vacuum deposition or spin coating. In this case, the hole blocking material used is not particularly limited, and any known substance used as a hole blocking material can be used. For example, Oxadiazole derivatives or benzotriazole derivatives, o-phenanthroline derivatives or hole blocking materials described in Japanese Patent Application Laid-Open No. 11-329734 (A1), among which the most representative ones include Balq (bis(8-hydroxy-2-methylquinoline)-(4-phenylphenoxy)aluminum), phenanthroline compounds (for example: BCP (bathocuproine) of UDC Company), etc.

[0148] The electron transport layer 500 is formed on the upper portion of the light-emitting layer 400 formed in the manner described above. The electron transport layer can be formed by methods such as vacuum deposition, spin coating, and casting. The deposition conditions of the electron transport layer vary depending on the compound used, but are generally preferably selected within a range of conditions similar to those used for forming the hole injection layer.

[0149] Next, the electron injection layer 600 may be formed by depositing an electron injection layer material on the electron transport layer 500 . In this case, the electron injection layer may be formed using general electron injection layer materials by methods such as vacuum deposition, spin coating, and casting.

[0150] The hole injection layer 200 , hole transport layer 300 , light emitting layer 400 , and electron transport layer 500 of the organic light emitting element may use the compound according to the present invention or the substances listed in Table 1 below, or may use the compound according to the present invention and known substances simultaneously.

[0151]

Table 1

[0152]

[0153] The second electrode 2000 can be formed on the electron injection layer 600 by vacuum deposition or spin coating. Various metals can be used as the second electrode, and specific examples include aluminum, gold, and silver.

[0154] As the organic light-emitting element according to the present invention, not only the organic light-emitting element composed of the first electrode (anode), the hole injection layer, the hole transport layer, the light-emitting layer, the electron transport layer, the electron injection layer, and the second electrode (cathode) can be used, but also organic light-emitting elements of various structures can be used, and one or two intermediate layers can be additionally formed as needed.

[0155] The thickness of each organic layer formed by the present invention as described above can be adjusted as needed, specifically, it can be 10 to 1000 nm, more specifically, 30 to 100 nm.

[0156] Furthermore, the present invention can adjust the thickness of the organic layer containing the compound represented by Chemical Formula 1 on a molecular basis, thus having advantages of uniform surface and excellent morphological stability.

[0157] Next, the present invention will be described in more detail by using a synthesis example of a compound according to an embodiment of the present invention and an example of manufacturing an organic light-emitting device. The following examples are merely illustrative of the present invention, and the scope of the present invention is not limited to the following examples.

[0158] <Production Example 1> Synthesis of Intermediate Compound IM1

[0159] The intermediate compound IM1 was synthesized according to the following reaction formula.

[0160]

[0161] 100 ml of 1,4-dioxane was poured into a round-bottom flask, followed by dissolving 5.0 g of 9,9'-spirobi[fluoren]-2-ylboronic acid and 5.0 g of 2-bromo-4'-iodo-1,1'-biphenyl. 20 ml of K2CO3 (2 M aqueous solution) and 0.5 g of Pd(PPh3)4 were added, followed by stirring under reflux. The reaction progress was confirmed by thin-layer chromatography (TLC), and the reaction was terminated by adding water. The organic layer was extracted with dichloromethane (MC), filtered under reduced pressure, and recrystallized to obtain 5.0 g of the intermediate compound IM1 (yield 66%).

[0162] <Production Example 2> Synthesis of Intermediate Compound IM2

[0163] The synthesis was carried out in the same manner as in Preparation Example 1, wherein compound IM2 was synthesized using the starting materials shown in the following reaction formula as described below.

[0164]

[0165] <Production Example 3> Synthesis of Intermediate Compound IM3

[0166] The synthesis was carried out in the same manner as in Preparation Example 1, wherein compound IM3 was synthesized using the starting materials shown in the following reaction formula as described below.

[0167]

[0168] <Production Example 4> Synthesis of Intermediate Compound IM4

[0169] The synthesis was carried out in the same manner as in Preparation Example 1, wherein compound IM4 was synthesized using the starting materials shown in the following reaction formula as described below.

[0170]

[0171] <Production Example 5> Synthesis of Intermediate Compound IM5

[0172] The synthesis was carried out in the same manner as in Preparation Example 1, wherein compound IM5 was synthesized using the starting materials shown in the following reaction formula as described below.

[0173]

[0174] <Synthesis Example 1> Synthesis of Compound 7

[0175]

[0176] A round-bottom flask was filled with 90 ml of toluene, and 3.0 g of the intermediate compound IM1 produced in Production 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 and stirred under reflux. The reaction progress was confirmed by thin-layer chromatography (TLC), and the reaction was terminated by adding water. The organic layer was extracted with dichloromethane (MC), filtered under reduced pressure, and then column purified and recrystallized to obtain 2.1 g of compound 7 (yield 60%).

[0177] m / z: 635.26 (100.0%), 636.26 (53.4%), 637.27 (14.0%), 638.27 (2.4%)

[0178] <Synthesis Example 2> Synthesis of Compound 62

[0179]

[0180] Compound 62 was synthesized in the same manner as in Synthesis Example 1, except that the intermediate compound IM2 prepared in Preparation Example 2 was used instead of IM1 (yield: 67%).

[0181] m / z: 635.26 (100.0%), 636.26 (53.4%), 637.27 (14.0%), 638.27 (2.4%)

[0182] <Synthesis Example 3> Synthesis of Compound 122

[0183]

[0184] Compound 122 was synthesized in the same manner as in Synthesis Example 1, except that the intermediate compound IM3 prepared in Preparation Example 3 was used instead of IM1 (yield: 70%).

[0185] m / z: 635.26 (100.0%), 636.26 (53.4%), 637.27 (14.0%), 638.27 (2.4%)

[0186] <Synthesis Example 4> Synthesis of Compound 127

[0187]

[0188] Compound 127 was synthesized in the same manner as in Synthesis Example 1, except that the intermediate compound IM4 prepared in Preparation Example 4 was used instead of IM1 (yield: 63%).

[0189] m / z: 635.26 (100.0%), 636.26 (53.4%), 637.27 (14.0%), 638.27 (2.4%)

[0190] <Synthesis Example 5> Synthesis of Compound 134

[0191]

[0192] Compound 134 was synthesized in the same manner as in Synthesis Example 1, except that the intermediate compound IM5 prepared in Preparation Example 5 was used instead of IM1 (yield: 65%).

[0193] m / z: 711.29 (100.0%), 712.30 (59.9%), 713.30 (17.6%), 714.30 (3.4%)

[0194] Manufacturing of organic light-emitting devices

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

[0196]

Table 2

[0197]

[0198] <Example 1>

[0199] Use distilled water to coat The glass substrate with a thin film of indium tin oxide (ITO) of 1000 nm was ultrasonically cleaned. After washing with distilled water, ultrasonic cleaning was performed using solvents such as isopropyl alcohol, acetone, and methanol, and then dried. The substrate was then transferred to a plasma cleaner and cleaned with oxygen plasma for 5 minutes. A thermal evaporator was then used to deposit a hole injection layer on the top of the ITO substrate. HI01 and HATCN is used as a hole transport layer to form a film HT01, as a light-emitting auxiliary layer film The compound prepared in Synthesis Example 1 is then formed into a film as a light-emitting layer. Next, a film was formed as an electron transport layer. After ET01:Liq (1:1) was used to make the film LiF, Aluminum (Al) is then placed in a glove box and the element is encapsulated to produce an organic light-emitting element.

[0200] <Example 2> to <Example 5>

[0201] The organic light-emitting elements were manufactured by the same method as in Example 1, and the compounds manufactured in Synthesis Examples 2 to 5 were used to deposit and form a light-emitting auxiliary layer.

[0202] <Comparative Example 1> to <Comparative Example 7>

[0203] The same method as in Example 1 was used to manufacture an organic light-emitting element, wherein a light-emitting auxiliary layer was formed by depositing comparative compounds 1 to 7 shown in Table 3 below.

[0204]

Table 3

[0205]

[0206] <Performance Evaluation of Organic Light-Emitting Elements>

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

[0208]

Table 4

[0209] Op.V <![CDATA[mA / cm 2 ]]> Cd / A QE (%) CIEx CIE LT95 Example 1 3.45 10 7.8 6.7 0.139 0.110 143 Example 2 3.46 10 8.0 6.9 0.140 0.109 155 Example 3 3.48 10 8.3 7.5 0.140 0.110 175 Example 4 3.49 10 8.5 7.3 0.142 0.110 166 Example 5 3.48 10 8.4 7.1 0.140 0.109 180 Comparative Example 1 3.51 10 6.8 4.8 0.140 0.111 100 Comparative Example 2 3.52 10 7.0 5.7 0.141 0.109 108 Comparative Example 3 3.54 10 7.3 5.9 0.140 0.110 113 Comparative Example 4 3.52 10 7.0 6.0 0.142 0.110 94 Comparative Example 5 3.70 10 7.3 6.3 0.140 0.110 68 Comparative Example 6 3.50 10 6.4 5.1 0.142 0.110 75 Comparative Example 7 3.65 10 6.9 5.8 0.142 0.111 100

[0210] By comparing with the examples of the present invention, it can be found that the organic light emitting element of the examples can not only achieve a lower driving voltage, but also has an excellent effect of improving the luminous efficiency.

[0211] Specifically, the organic light-emitting element according to the embodiment of the present invention uses a compound with an extended linker to form a light-emitting auxiliary layer, so the π conjugation of the light-emitting auxiliary layer can be increased compared with the organic light-emitting elements of Comparative Examples 1 to 3, thereby ensuring excellent thin film arrangement.

[0212] Specifically, the organic light-emitting elements of Comparative Examples 1 to 3 use a compound in which the linker L between the spirobifluorenyl group and the amine group is a phenylene group as the light-emitting auxiliary layer, while the organic light-emitting element of Comparative Example 7 uses a compound in which the linker L is a fluorenyl group as the light-emitting auxiliary layer. In contrast, the embodiments of the present invention use a compound in which the linker L is not a fluorenyl group but an aromatic group with 10 or more carbon atoms, such as biphenyl or terphenyl, as the light-emitting auxiliary layer. This increases the π conjugation of the light-emitting auxiliary layer and ensures excellent thin film alignment.

[0213] Furthermore, the organic light-emitting element of Comparative Example 4 includes an amine compound in which a fluorenyl group is substituted with a substituent that functions as an electron donor (Ar1 or Ar2 in Chemical Formula 1) in its light-emitting-assisting layer, resulting in a higher highest occupied molecular orbital (HOMO) value. Furthermore, the organic light-emitting element of Comparative Example 6 includes an amine compound in which a fluorenyl group is substituted with a methyl group and a biphenyl group in its light-emitting-assisting layer, resulting in inferior driving voltage, efficiency, and service life compared to the organic light-emitting element of Comparative Example 4.

[0214] In contrast, the present invention includes in the light-emitting auxiliary layer a compound in which Ar1 and Ar2 in Chemical Formula 1 are respectively a phenyl group or a fused aryl group, and the fused aryl group is an unsubstituted fused aryl group such as a naphthyl group, a phenanthrenyl group or a triphenylene group, and thus has a lower highest occupied molecular orbital (HOMO), thereby effectively improving the driving voltage, efficiency and service life of the organic light-emitting element.

[0215] Meanwhile, the organic light-emitting element of Comparative Example 5 uses a compound in the light-emitting auxiliary layer that has a structure in which a phenyl group is substituted in the benzene ring at the site connected to the amino group in the spirobifluorenyl group (i.e., a structure in which position 2 of the spirobifluorenyl group is substituted with a phenyl group). This leads to a low Hall mobility due to severe distortion of the molecular structure. In contrast, the embodiments of the present invention minimize molecular distortion and effectively improve Hall mobility by not adding a compound that has a substituent such as a phenyl group to the benzene ring at the site connected to the amino group in the spirobifluorenyl group.

[0216] Therefore, the organic light-emitting element according to the embodiment of the present invention, by including the compound according to the present invention in the light-emitting auxiliary layer, can have a lower highest occupied molecular orbital (HOMO) value and a higher lowest occupied molecular orbital (LUMO) and T1, thereby effectively improving the Hall mobility and easily achieving electron interception and exciton interception, thereby ensuring excellent charge balance within the light-emitting layer. Furthermore, the organic light-emitting element of the embodiment can achieve a lower driving voltage by suppressing the decay phenomenon, thereby significantly improving the efficiency and service life of the element.

Claims

1. A compound represented by the following chemical formula 2: Chemical formula 2 In the chemical formula 2, Ar1 and Ar2 are phenyl groups; R1 to R3 are each independently hydrogen or deuterium; R4 and R5 are each independently hydrogen or deuterium, l, m, and n are each independently an integer from 0 to 4, and o is 1 or 2.

2. The compound according to claim 1, The chemical formula 2 is a compound represented by the following chemical formula 3: In the chemical formula 3, The definitions of Ar1, Ar2, R1 to R5, l, m, n and o are the same as those in Chemical Formula 2. The phenylene group is linked to any one of the * positions of the spirobifluorenyl group.

3. The compound according to claim 2, The chemical formula 3 is a compound represented by the following chemical formula 3-1 or chemical formula 3-2: Chemical formula 3-1 Chemical formula 3-2 In the chemical formula 3-1 and the chemical formula 3-2, The definitions of Ar1, Ar2, R1 to R3, l, m, n, R4, R5 and o are the same as those in Chemical Formula 3.

4. The compound according to claim 1, The chemical formula 2 is a compound represented by the following chemical formula 4 or chemical formula 5: Chemical formula 4 Chemical formula 5 In the chemical formula 4 and the chemical formula 5, The definitions of Ar1, Ar2, R1 to R5, and o are the same as those in Chemical Formula 2, and the phenylene group is connected to any one of the * positions of the spirobifluorenyl group.

5. The compound according to claim 4, In the chemical formula 4, Contains one or more of o-phenylene and m-phenylene.

6. The compound according to claim 4, In the chemical formula 5, Contains p-phenylene.

7. The compound according to claim 1, R4 and R5 are each independently hydrogen.

8. The compound according to claim 1, Contains any one of the structures represented by the following A-1 to A-23:

9. The compound according to claim 1, wherein R1 to R3 are each independently hydrogen.

10. The compound according to claim 1, The compound of Chemical Formula 2 is any one of the compounds represented by the following chemical formulas:

11. An organic light-emitting element, comprising: 1st electrode; an organic layer located on the first electrode; and a second electrode, located on the organic layer; The organic layer comprises the compound according to any one of claims 1 to 10.

12. The organic light-emitting element according to claim 11, The organic layer is any one or more of a hole injection layer, a hole transport layer, and a light-emitting auxiliary layer.

13. The organic light-emitting element according to claim 11, The organic layer is a light-emitting auxiliary layer located between the hole transport layer and the light-emitting layer.

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