Organic compound for cover layer and organic light-emitting device containing the same

Abstract

The present invention relates to a compound for a covering layer and an organic light-emitting device comprising the same. The compound for a covering layer in one embodiment of the present invention is suitable for an organic light-emitting device and can improve the external luminous efficiency, color coordinates and life of the organic light-emitting device.

Description

Technical Field

[0001] The present invention relates to an organic compound for a cover layer and an organic light-emitting device comprising the same. Background Art

[0002] In an organic light-emitting device, the materials used as the organic layer can be roughly classified into light-emitting materials, hole injection materials, hole transport materials, electron transport materials, electron injection materials, etc. according to their functions. In addition, the above-mentioned light-emitting materials can be classified into fluorescent materials derived from the singlet excited state of electrons and phosphorescent materials derived from the triplet excited state of electrons according to the light-emitting mechanism, and can be classified into blue, green, and red light-emitting materials according to the light-emitting color.

[0003] A general organic light-emitting device may have the following structure: an anode is formed on the upper part of a substrate, and a hole transport layer, a light-emitting layer, an electron transport layer and a cathode are sequentially formed on the upper part of the anode. The hole transport layer, the light-emitting layer and the electron transport layer are organic thin films formed of organic compounds.

[0004] The driving principle of the organic light-emitting device having the above structure is as follows. When a voltage is applied between the anode and the cathode, holes injected from the anode move to the light-emitting layer via the hole transport layer, while electrons injected from the cathode move to the light-emitting layer via the electron transport layer. The holes and electrons moved to the light-emitting layer recombine to generate excitons. The excitons are converted from an excited state to a ground state to generate light.

[0005] The efficiency of an organic light-emitting device can generally be divided into internal luminous efficiency and external luminous efficiency. The internal luminous efficiency is related to how effectively excitons are generated in an organic layer such as a hole transport layer, a light-emitting layer, and an electron transport layer interposed between the first electrode and the second electrode to achieve light conversion. Theoretically, the internal luminous efficiency is about 25% for fluorescence and about 100% for phosphorescence.

[0006] On the other hand, the external luminous efficiency represents the efficiency of extracting light generated from the organic layer to the outside of the organic light-emitting device, and is generally extracted to the outside at a level of about 20% of the internal luminous efficiency.

[0007] As a method for improving this external luminous efficiency, that is, light extraction efficiency, in order to prevent the light emitted to the outside from being totally reflected and lost, a variety of organic compounds are used as capping layers. In order to improve the performance of organic light-emitting devices, efforts are continuously made to develop organic compounds with high refractive index and thin film stability that can improve the external luminous efficiency.

[0008] Prior art literature

[0009] Patent Literature

[0010] Korean Patent Publication No. 10-2004-0098238 Summary of the invention

[0011] The problem to be solved by the present invention is to provide a compound for a covering layer having a wide band gap in the visible light region that cannot absorb the organic light-emitting device and a high refractive index, thereby improving the color purity and external luminous efficiency of the organic light-emitting device, and an organic light-emitting device including a covering layer containing the above compound.

[0012] Another problem to be solved by the present invention is to provide a compound for a covering layer that can improve the refractive index to improve efficiency, and by increasing the absorption wavelength in the ultraviolet region, can improve stability when exposed to external ultraviolet rays to increase the lifespan, and an organic light-emitting device including a covering layer containing the above-mentioned compound.

[0013] Another problem to be solved by the present invention is to provide a compound for a covering layer that increases the internal conjugation of the compound to improve the film arrangement of molecules to form a stable film, thereby increasing the life of the organic light-emitting device by blocking external air and moisture, and an organic light-emitting device including a covering layer containing the above compound.

[0014] Another problem to be solved by the present invention is to provide a compound for a covering layer having high Tg and high Td to prevent intermolecular recrystallization, thereby being able to maintain a stable thin film against the heat generated when the organic light-emitting device is driven, and an organic light-emitting device including a covering layer containing the above compound.

[0015] However, the problems to be solved by the present invention are not limited to the problems described above, and those skilled in the art should clearly understand other problems not described through the following descriptions.

[0016] A first embodiment of the present invention provides a compound for a cover layer represented by the following Chemical Formula 1.

[0017] Chemical formula 1

[0018]

[0019] In the above chemical formula 1,

[0020] X and Y are each independently O, S, NR, N-* or CR`R`` (wherein -* represents a site bonded to L1 or L2),

[0021] R, R', R'', R1 to R4 are each independently hydrogen, deuterium, halogen, nitro, nitrile, substituted or unsubstituted C 1～30 Alkyl, substituted or unsubstituted C 2～30 Alkenyl, substituted or unsubstituted C 1～30 Alkoxy, substituted or unsubstituted C1～30 Thioether, substituted or unsubstituted C 6～50 Aryl, or substituted or unsubstituted C 2～50 Heteroaryl (wherein R` and R`` may be bonded to form a ring or not, when X is N and Y is CR`R``, R` and R`` are substituted or unsubstituted C 6～50 Aryl, or substituted or unsubstituted C 2～50 Except for the case of heteroaryl),

[0022] l and o are each independently 0 or an integer from 1 to 4,

[0023] m and n are each independently 0 or an integer from 1 to 4,

[0024] L1 is a directly bonded, substituted or unsubstituted C 6～50 Arylene, or substituted or unsubstituted C 2～50 Heteroarylene,

[0025] L2 is substituted or unsubstituted C 6～50 Arylene, or substituted or unsubstituted C 2～50 Heteroarylene,

[0026] Ar1 to Ar3 are each independently substituted or unsubstituted C 6～50 Arylene, or substituted or unsubstituted C 2～50 Heteroarylene.

[0027] The second embodiment of the present invention provides an organic light-emitting device, which includes: a first electrode and a second electrode; an organic layer, which is located inside the first electrode and the second electrode; and a covering layer, which is arranged outside one or more electrodes of the first electrode and the second electrode, and contains the compound for the covering layer of the first embodiment of the present invention.

[0028] The compound for the capping layer of one embodiment of the present invention has a wide band gap in the visible light region that cannot absorb the organic light-emitting device and has a high refractive index, thereby showing an effect of improving the color purity and external luminous efficiency of the organic light-emitting device.

[0029] Furthermore, the compound for the cover layer of one example of the present invention shows an effect of improving the efficiency by improving the refractive index and increasing the absorption wavelength in the ultraviolet region to improve the stability when exposed to external ultraviolet rays and thus increase the life span.

[0030] Furthermore, the compound for the covering layer of one embodiment of the present invention increases the internal conjugation of the compound to improve the film arrangement of molecules to form a stable film, thereby showing the effect of increasing the life of the organic light-emitting device by blocking external air and moisture.

[0031] Furthermore, the compound for the cover layer of one embodiment of the present invention has high Tg and high Td to prevent intermolecular recrystallization, thereby showing the effect of maintaining a stable thin film against the heat generated when the organic light-emitting device is driven. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic diagram showing an organic light emitting device according to an example of the present invention.

[0033] Figure 2 The graph is a graph comparing the absorption intensity of the compound of one example of the present invention and the compound of a comparative example in the ultraviolet region.

[0034] Description of Reference Numerals

[0035] 100: Substrate

[0036] 200: Hole injection layer

[0037] 300: Hole transport layer

[0038] 400: Luminous layer

[0039] 500: Electron transport layer

[0040] 600: Electron injection layer

[0041] 1000: First electrode (anode)

[0042] 2000: Second electrode (cathode)

[0043] 3000: Overlay DETAILED DESCRIPTION

[0044] Hereinafter, examples and embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the present invention.

[0045] However, the present invention can be implemented in many different forms and is not limited to the examples and embodiments described herein. In addition, in the drawings, in order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are marked with similar reference numerals throughout the specification.

[0046] Throughout the specification of the present invention, when one component is located “on” another component, it includes not only the case where one component is in contact with the other component, but also the case where other components exist between the two components.

[0047] Throughout the present specification, when a part "includes" a structural element, unless there is a special record to the contrary, it means that other structural elements may also be included, rather than excluding other structural elements. The terms "about", "substantially", etc. used throughout the present specification are used with their numerical values ​​or close to their numerical values ​​when the mentioned meanings indicate inherent preparation and material tolerances, so as to prevent unscrupulous infringers from improperly using the disclosure that mentions accurate or absolute numerical values ​​to help understand the present invention. The terms "(of) step" or "step of" used throughout the present specification do not mean "step for" .

[0048] Throughout the specification of the present invention, the term "combination thereof" contained in the expression of Markush form means a mixture or combination of one or more selected from the group consisting of multiple structural elements recorded in the expression of Markush form, and means including one or more selected from the group consisting of the above-mentioned multiple structural elements.

[0049] Throughout the present specification, the description "A and / or B" means "A or B, or A and B".

[0050] Throughout the present specification, the term "aryl" or "arylene" may mean a group containing C 6-50 Aromatic hydrocarbon ring groups, for example, phenyl, benzyl, naphthyl, biphenyl, terphenyl, fluorene, phenanthryl, triphenylalkenyl, phenylalkenyl, Benzotriphenylbenzene, fluoranthene, benzofluorenyl, benzotriphenylene, benzo "Heteroaryl" or "heteroarylene" refers to an aromatic ring such as a C group containing at least one heteroelement. 2-50 The aromatic ring includes, for example, a pyrrolinyl group, a pyrazinyl group, a pyridyl group, an indolyl group, an isoindolyl group, a furyl group, a benzofuranyl group, an isobenzofuranyl group, a dibenzofuranyl group, a benzothiophenyl group, a dibenzothiophenyl group, a quinolyl group, an isoquinolyl group, a quinoxalinyl group, a carbazolyl group, a phenanthrylidinyl group, an acridinyl group, a phenanthrolinyl group, a thienyl group, and a heterocyclic group formed by a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, a triazine ring, an indole ring, a quinoline ring, an acridinium ring, a pyrrolidine ring, a dioxane ring, a piperidine ring, a morpholine ring, a piperazine ring, a carbazole ring, a furan ring, a thiophene ring, an oxazole ring, an oxadiazole ring, a benzoxazole ring, a thiazole ring, a thiadiazide ring, a benzothiazole ring, a triazole ring, an imidazole ring, a benzimidazole ring, a pyran ring, and a dibenzofuran ring.

[0051] Throughout the present specification, the term "substituted" or "substitutable" may mean a substituent selected from deuterium, halogen, amino, nitrile, nitro or C1-C 30 Alkyl, C2~C 30 Alkenyl, C1~C30 Alkoxy, C3~C 20 Cycloalkyl, C3~C 20 Heterocycloalkyl, C6~C 30 The aromatic group and C3~C 30 In addition, in the entire specification of the present invention, the same reference numerals have the same meaning unless otherwise specified.

[0052] A first embodiment of the present invention provides a compound for a cover layer represented by the following Chemical Formula 1.

[0053] Chemical formula 1

[0054]

[0055] In the above chemical formula 1,

[0056] X and Y are each independently O, S, NR, N-* or CR`R`` (wherein -* represents a site bonded to L1 or L2),

[0057] R, R', R'', R1 to R4 are each independently hydrogen, deuterium, halogen, nitro, nitrile, substituted or unsubstituted C 1～30 Alkyl, substituted or unsubstituted C 2～30 Alkenyl, substituted or unsubstituted C 1～30 Alkoxy, substituted or unsubstituted C 1～30 Thioether, substituted or unsubstituted C 6～50 Aryl, or substituted or unsubstituted C 2～50 Heteroaryl (wherein R` and R`` may be bonded to form a ring or not, when X is N and Y is CR`R``, R` and R`` are substituted or unsubstituted C 6～50 Aryl, or substituted or unsubstituted C 2～50 Except for the case of heteroaryl),

[0058] l and o are each independently 0 or an integer from 1 to 4,

[0059] m and n are each independently 0 or an integer from 1 to 4,

[0060] L1 is a directly bonded, substituted or unsubstituted C 6～50 Arylene, or substituted or unsubstituted C 2～50 Heteroarylene,

[0061] L2 is substituted or unsubstituted C 6～50 Arylene, or substituted or unsubstituted C 2～50 Heteroarylene,

[0062] Ar1 to Ar3 are each independently substituted or unsubstituted C 6～50 Arylene, or substituted or unsubstituted C 2～50 Heteroarylene.

[0063] In the case of the compound for the covering layer of the above chemical formula 1 of one embodiment of the present invention, two conjugated tricyclics (dibenzofuran, dibenzothiophene, carbazole or fluorene) are linearly bonded and not directly bonded to the nitrogen of the amine, but bonded through a linking group such as an arylene group or a heteroarylene group, thereby maintaining a wide band gap in the visible light region that cannot absorb light and maintaining a high refractive index. Through this characteristic, the compound for the covering layer of the present invention can improve the color purity and external luminous efficiency of the organic light-emitting device.

[0064] In addition, in the case of the compound for the covering layer of the above chemical formula 1 of one example of the present invention, an aryl group or a heteroaryl group is included on the other side of the above conjugated tricyclic bonded amine, thereby improving the refractive index while increasing the absorption wavelength in the ultraviolet region, thereby improving the stability when exposed to external ultraviolet rays. Through this characteristic, the compound for the covering layer of the present invention can improve the external luminous efficiency of the organic light-emitting device and extend the lifespan.

[0065] For the compound for covering layer of the above Chemical Formula 1 according to one embodiment of the present invention, the refractive index at 450 nm may be 2.1 or more, specifically 2.2 or more, and the absorption intensity at 380 nm, which is the ultraviolet absorption region, may be 0.6 or more, specifically 0.7 or more.

[0066] Furthermore, the compound for the cover layer of the above chemical formula 1 of one embodiment of the present invention increases conjugation through an arylene or heteroarylene linker, so that the film arrangement of molecules becomes excellent, thereby forming a stable film. Through this characteristic, the life of the organic light-emitting device can be improved by blocking external air and moisture.

[0067] Furthermore, the cover layer compound of the above Chemical Formula 1 according to one embodiment of the present invention has high Tg and high Td due to two conjugated tricyclic rings (dibenzofuran, dibenzothiophene, carbazole or fluorene), thereby suppressing intermolecular recrystallization, thereby maintaining a stable thin film against the heat generated during driving.

[0068] That is, when the compound for a covering layer of one embodiment of the present invention is applied to a covering layer and the covering layer is disposed outside the electrode of an organic light-emitting device, the external light-emitting efficiency can be improved. When light generated in the organic layer between the first electrode and the second electrode of the organic light-emitting device is extracted to the outside of the organic light-emitting device, the light emitted to the outside can be prevented from being totally reflected and lost.

[0069] The compound for the covering layer of one embodiment of the present invention can have a high refractive index due to the structural features as described above. Due to the outstanding film stability, when it is used as a covering layer of an organic light-emitting device, it can improve the external luminous efficiency, color coordinates and life of the organic light-emitting device.

[0070] In one embodiment of the present invention, the above Chemical Formula 1 can be represented by the following Chemical Formula 2.

[0071] Chemical formula 2

[0072]

[0073] In the above chemical formula 2,

[0074] X, Y, R, R', R'', R1 to R4, l, m, n, o, L1, Ar1 to Ar3 are as defined in the above chemical formula 1,

[0075] R5 is hydrogen, deuterium, halogen, nitro, nitrile, substituted or unsubstituted C 1～30 Alkyl, substituted or unsubstituted C 2～30 Alkenyl, substituted or unsubstituted C 1～30 Alkoxy, substituted or unsubstituted C 1～30 Thioether, substituted or unsubstituted C 6～50 Aryl, or substituted or unsubstituted C 2～50 Heteroaryl,

[0076] p is an integer of 1 to 4.

[0077] In one embodiment of the present invention, the above Chemical Formula 1 can be represented by the following Chemical Formula 3.

[0078] Chemical formula 3

[0079]

[0080] In the above chemical formula 3,

[0081] X, Y, R, R`, R``, R1 to R4, L1, Ar1 to Ar3 and p are as defined in the above Chemical Formula 2.

[0082] In one embodiment of the present invention, the above Chemical Formula 1 can be represented by one of the following Chemical Formulas 4 to 6.

[0083] Chemical formula 4

[0084]

[0085] Chemical formula 5

[0086]

[0087] Chemical formula 6

[0088]

[0089] In the above Chemical Formulae 4 to 6,

[0090] X, Y, R, R`, R``, R1 to R4, L1, Ar1 to Ar3 and p are as defined in the above Chemical Formula 2.

[0091] The compounds represented by the above Chemical Formulae 2 to 6 are the same as the compound of Chemical Formula 1, wherein two conjugated tricyclic rings (dibenzofuran, dibenzothiophene, carbazole or fluorene) are linearly bonded and not directly bonded to the nitrogen of the amine, but have a linking group such as an arylene group or a heteroarylene group.

[0092] Therefore, the compounds represented by the above chemical formulas 2 to 6 can also maintain a wide band gap that cannot absorb visible light, and can maintain a high refractive index, and can improve the refractive index while increasing the absorption wavelength in the ultraviolet region to improve the stability when exposed to external ultraviolet rays. Due to increased conjugation, the film arrangement of molecules becomes excellent, thereby forming a stable film, and due to high Tg and high Td, it is possible to suppress intermolecular recrystallization. Due to such characteristics, for an organic light-emitting device including a covering layer containing the compound for a covering layer of the present invention, the color purity and external luminous efficiency are improved, and the stability to moisture and heat, etc. is improved, thereby extending the life.

[0093] According to an example of the present invention, in the chemical formula 1, the above X and Y can be independently O, S, NR or N-*. That is, the tricyclic ring can be dibenzofuran, dibenzothiophene or carbazole. In this case, the efficiency of the organic light-emitting device can be further improved, because the bonding energy between carbon and O, S, and N atoms is high, the stability of the molecule is outstanding, and the life span can be increased.

[0094] Furthermore, according to an example of the present invention, in the chemical formula 1, X and Y can be independently O or S. That is, the tricyclic ring can be dibenzofuran or dibenzothiophene. In this case, the efficiency of the organic light-emitting device can be further improved, and the lifespan can be further increased.

[0095] Furthermore, according to an example of the present invention, in the above Chemical Formula 1, R, R1 to R5 may be independently hydrogen, methyl, fluoro, methoxy, cyano, phenyl or biphenyl. In this case, the π conjugation of the substituents may be minimized to maintain a wide band gap.

[0096] Furthermore, according to an embodiment of the present invention, in the above Chemical Formula 1, R' and R" can each independently be hydrogen or methyl. In this case, the bulkiness of fluorene is minimized, thereby effectively improving the refractive index.

[0097] Furthermore, according to an embodiment of the present invention, the above Ar1 to Ar3 can be independently phenyl, naphthyl, biphenyl, terphenyl, phenanthryl, triphenylene, dibenzofuranyl, dibenzothiophene, pyridyl or a combination thereof. In this case, the absorption wavelength in the ultraviolet region is effectively increased.

[0098] Furthermore, according to an embodiment of the present invention, at least one of Ar1 to Ar3 may be a dibenzofuranyl group or a dibenzothiophene group. In this case, the bonding energy between carbon and O and S atoms is higher, so that the stability of the molecule is very outstanding and the absorption in the visible light region can be minimized.

[0099] Furthermore, according to an example of the present invention, at least one of Ar1 to Ar3 may include a terphenyl group. In this case, the life of the organic light-emitting device can be greatly improved.

[0100] Furthermore, according to an embodiment of the present invention, the above-mentioned p can be an integer of 1 or 2, or L1 can be a direct bond, p can be an integer of 1 or 2, and L1 can be a direct bond. In this case, it has the effect of minimizing π conjugation to maintain a wide band gap while having a high refractive index.

[0101] In one embodiment of the present invention, the compounds for the covering layer represented by the above Chemical Formulae 1 to 6 can be synthesized by the following reaction formulas, but are not limited thereto and can be synthesized by various methods.

[0102] Reactive

[0103]

[0104] In one example of the present invention, the compound represented by the above chemical formula 1 may be one of the following compounds 1 to 612, but is not limited thereto:

[0105]

[0106]

[0107]

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[0109]

[0110]

[0111]

[0112]

[0113]

[0114]

[0115]

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[0117]

[0118]

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[0120]

[0121]

[0122]

[0123]

[0124]

[0125]

[0126]

[0127]

[0128]

[0129]

[0130]

[0131]

[0132]

[0133]

[0134]

[0135]

[0136]

[0137]

[0138]

[0139]

[0140]

[0141]

[0142]

[0143]

[0144]

[0145]

[0146]

[0147]

[0148]

[0149]

[0150]

[0151]

[0152]

[0153]

[0154]

[0155]

[0156] A second embodiment of the present invention provides an organic light emitting device including a capping layer including a compound represented by one of Chemical Formulae 1 to 6 above.

[0157] According to one example of the present invention, an organic light-emitting device may include: a first electrode and a second electrode, an organic layer disposed inside the first electrode and the second electrode; and a covering layer disposed outside one or more of the first electrode and the second electrode and comprising the compound for the covering layer of the present invention.

[0158] Among the two side surfaces of the first electrode or the second electrode, the side adjacent to the organic layer between the first electrode and the second electrode is regarded as the inner side, and the side not adjacent to the organic layer is regarded as the outer side. That is, when the covering layer is arranged outside the first electrode, the first electrode is interposed between the covering layer and the organic layer, and when the covering layer is arranged outside the second electrode, the second electrode is interposed between the covering layer and the organic layer.

[0159] According to one example of the present invention, in the organic light-emitting device, a plurality of organic layers may be interposed inside the first electrode and the second electrode, and a covering layer may be formed outside at least one of the first and second electrodes. The covering layer is formed outside the first electrode and outside the second electrode, or may be arranged outside the first electrode or outside the second electrode. The covering layer may include the compound for covering layer of the present invention.

[0160] Furthermore, according to an embodiment of the present invention, an organic layer having multiple functions may be formed on the outer sides of the first electrode and the second electrode with the cover layer interposed therebetween.

[0161] That is, the covering layer can be formed directly on the outer surface of the first electrode (or the second electrode), or an organic layer having multiple functions can be formed on the outer surface of the first electrode (or the second electrode), and a covering layer containing the compound of the present invention can be formed on the above-mentioned organic layer.

[0162] According to an example of the present invention, the covering layer may include the compound for a covering layer according to an example of the present invention alone, or may include two or more kinds of known compounds together.

[0163] An organic light-emitting device of an embodiment of the present invention includes one or more organic layers between the first electrode and the second electrode, that is, inside the first electrode and the second electrode, and a covering layer may be formed outside the first electrode and the second electrode. The organic layer may generally be a hole transport layer, a light-emitting layer, and an electron transport layer constituting a light-emitting portion, but is not limited thereto.

[0164] The above-mentioned organic light-emitting device 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 (anode) and the second electrode (cathode).

[0165] For example, the organic light emitting device may be Figure 1The organic light-emitting device can be stacked in order from bottom to top: first electrode (anode, hole injection electrode 1000) / hole injection layer 200 / hole transport layer 300 / light-emitting layer 400 / electron transport layer 500 / electron injection layer 600 / second electrode (cathode, electron injection electrode 2000) / covering layer 3000.

[0166] As described above, in the case of the compound for the covering layer of one embodiment of the present invention, two conjugated tricyclic rings (dibenzofuran, dibenzothiophene, carbazole or fluorene) are linearly bonded and have a linking group such as an arylene group or a heteroarylene group between the nitrogen of the amine, thereby maintaining a wide band gap that cannot absorb visible light, and maintaining a high refractive index, while improving the refractive index and increasing the absorption wavelength in the ultraviolet region, thereby improving the stability when exposed to external ultraviolet rays, and because of the increase in conjugation, the thin film arrangement of the molecules becomes excellent, thereby forming a stable thin film, and because of the high Tg and Td, the recrystallization between molecules can be suppressed. As a result, in the case of the organic light-emitting device of the present invention, the color purity and external luminous efficiency are improved, and the stability to moisture and heat is improved, thereby extending the life.

[0167] exist Figure 1 In the embodiment, the substrate 100 may be a substrate for an organic light-emitting device, and in particular, may be a transparent glass substrate or a flexible plastic substrate having excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and waterproofness.

[0168] The first electrode 1000 is used as an anode for injecting holes into the organic light emitting device. In order to inject holes, a material with a low work function is used, and it can be formed of a transparent material such as indium tin oxide (ITO), indium zinc oxide (IZO), and graphene.

[0169] The hole injection layer material is deposited on the first electrode 1000 by vacuum deposition, spin coating, casting, LB (Langmuir-Blodgett) method, etc., thereby forming the hole injection layer 200. When the hole injection layer 200 is formed by the vacuum deposition method, the deposition conditions vary depending on the compound used as the material of the hole injection layer 200, the structure and thermal characteristics of the desired hole injection layer 200, etc., but generally, the deposition temperature is 50-500°C, 10 -8 Up to 10 -3 torr (torr) vacuum degree, 0.01 to The deposition rate, The thickness of the layer can be appropriately selected within the range of 1 to 5 μm. Furthermore, a charge generation layer can be deposited on the surface of the hole injection layer as required. As the charge generation layer material, conventional materials can be used, and HATCN can be exemplified.

[0170] Next, a hole transport layer material is deposited on the hole injection layer 200 by vacuum deposition, spin coating, casting, LB method, etc., thereby forming the hole transport layer 300. When the hole transport layer 300 is formed by the vacuum deposition method, the deposition conditions vary depending on the compound used, but generally, it is preferred to select conditions within the same range as those for forming the hole injection layer 200.

[0171] The hole transport layer 300 may be formed using a known compound. According to an embodiment of the present invention, the hole transport layer 300 may be more than one layer. Although not shown in the figure, a light-emitting auxiliary layer may be formed on the hole transport layer 300 .

[0172] The light-emitting layer material is deposited on the hole transport layer 300 or the light-emitting auxiliary layer by vacuum deposition, spin coating, casting, LB method, etc., thereby forming the light-emitting layer 400. When the light-emitting layer 400 is formed by the vacuum deposition method, the deposition conditions vary depending on the compound used, but generally, it is preferred to select conditions within the same range as those for forming the hole injection layer 200. In addition, the light-emitting layer material can use a known compound as a host or a dopant.

[0173] Furthermore, in the light-emitting layer 400, when used together with a phosphorescent dopant, in order to prevent triplet excitons or holes from diffusing to the electron transport layer 500, a hole suppression material (HBL) may be stacked by vacuum deposition or spin coating. The hole suppression material that can be used at this time is not particularly limited, but any substance can be selected from the known substances used as hole suppression materials. For example, oxadiazole derivatives or triazole derivatives, phenanthroline derivatives or hole suppression materials described in Japanese Patent Laid-Open No. 11-329734 (A1) can be cited. Typically, Balq (bis (8-hydroxy-2-methylquinoline) -aluminum biphenyl phenolate), phenanthroline compounds (such as BCP (Basso Coupoline) of Universal Display (UDC) Company) and the like can be used.

[0174] The electron transport layer 500 is formed on the light emitting layer 400 formed as above. At this time, the electron transport layer 500 can be formed by vacuum deposition, spin coating, casting, etc. Moreover, the deposition conditions of the electron transport layer 500 vary depending on the compound used, but generally, it is preferred to select conditions that are almost the same as those for forming the hole injection layer 200.

[0175] Afterwards, an electron injection layer material may be deposited on the electron transport layer 500 to form the electron injection layer 600. At this time, the electron transport layer 600 may be formed using conventional electron injection layer materials by vacuum deposition, spin coating, casting, and the like.

[0176] The hole injection layer 200 , the hole transport layer 300 , the light emitting layer 400 , and the electron transport layer 500 of the organic light emitting device may be made of the following materials, but are not limited thereto.

[0177]

[0178] The second electrode 2000 for injecting electrons is formed on the electron injection layer 600 by vacuum deposition or sputtering. Various metals can be used as the second electrode 2000. Specific examples include aluminum, gold, silver, magnesium and the like.

[0179] The organic light-emitting device of the present invention can not only adopt an organic light-emitting device with a first electrode 1000, a hole injection layer 200, a hole transport layer 300, a light-emitting layer 400, an electron transport layer 500, an electron injection layer 600, and a second electrode 2000 structure, but can also adopt the structure of an organic light-emitting device with various structures. According to needs, one or two intermediate layers can be formed.

[0180] As described above, the thickness of each organic layer formed according to the present invention can be adjusted to a desired extent, specifically, 10 to 1000 nm, more specifically, 20 to 150 nm.

[0181] According to an example of the present invention, in the first electrode 1000, a cover layer 3000 may be formed outside the first electrode 1000 which is not inside and where the hole injection layer 200 is interposed. Figure 1 As shown, in the second electrode 2000 , the capping layer 3000 may be formed outside the second electrode 2000 which is not inside and where the electron injection layer 600 is interposed, but the present invention is not limited thereto.

[0182] The cover layer 3000 may be formed by a deposition process, and the thickness of the cover layer 3000 may be 100 to 1000 μm. More specifically, it can be 300 to In this case, the transmittance of the cover layer can be prevented from being reduced.

[0183] The organic light-emitting compound of this embodiment can be applied to the contents described in the first embodiment of the present invention, but is not limited thereto.

[0184] Hereinafter, the present invention will be described in more detail by way of examples, but the scope of the present invention is not limited to these examples.

[0185] Synthesis of intermediates

[0186] In order to synthesize the target compound, an intermediate (IM) is synthesized.

[0187] Preparation Example 1: Synthesis of IM1

[0188] Step 1: Synthesis of IM1-1

[0189]

[0190] In a round-bottom flask, 15.0 g of dibenzo[b,d]furan-2-ylboronic acid and 25.5 g of 2,8-dibromodibenzo[b,d]furan were dissolved in 700 ml of 1,4-dioxane, and 100 ml of K2CO3 (2M) and 2.5 g of Pd(PPh3)4 were added, followed by reflux stirring. The reaction was confirmed by thin layer chromatography (TLC), and water was added to terminate the reaction. The organic layer was extracted with methyl cellulose (MC), filtered under reduced pressure, and then recrystallized to obtain intermediate IM1-1 (20.2 g, yield 69%).

[0191] Step 2: Synthesis of IM1-2

[0192]

[0193] In a round-bottom flask, 20.0 g of the above IM1-1 and 16.0 g of bis(pinacolato)diboron were dissolved in 400 ml of 1,4-dioxane, and 14.2 g of KOAc and 0.2 g of Pd(dppf)Cl2 were added, followed by reflux stirring. The reaction was confirmed by thin layer chromatography, and water was added to terminate the reaction. The organic layer was extracted with methylcellulose, filtered under reduced pressure, and then recrystallized to obtain the intermediate IM1-2 (16.0 g, yield 72%).

[0194] Step 3: Synthesis of IM1

[0195]

[0196] In a round-bottom flask, 15.0 g of the above IM1-2 and 10.1 g of 1-bromo-4-iodobenzene were dissolved in 400 ml of 1,4-dioxane, and 50 ml of K2CO3 (2M) and 1.2 g of Pd(PPh3)4 were added, followed by reflux stirring. The reaction was confirmed by thin layer chromatography, and water was added to terminate the reaction. The organic layer was extracted with methyl cellulose, filtered under reduced pressure, and then recrystallized to obtain the intermediate IM1 (10.2 g, yield 64%).

[0197] Preparation Examples 2 to 9: Synthesis of IM2 to IM9

[0198] The synthesis was carried out in the same manner as the above IM1, and the starting materials were changed as shown in the following Table 1 to synthesize the following IM2 to IM9.

[0199]

[0200] Table 1

[0201]

[0202] Synthesis of compounds for coatings

[0203] Example 1: Synthesis of Compound 10

[0204]

[0205] In a round-bottom flask, 3.0 g of IM1 prepared in Preparation Example 1, 3.2 g of di([1,1':4',1"-triphenyl]-4-yl)amine, 0.9 g of t-BuONa, 0.2 g of Pd2(dba)3, and 0.3 ml of (t-Bu)3P were dissolved in 1000 ml of toluene and refluxed with stirring. The reaction was confirmed by thin layer chromatography and terminated after adding water. The organic layer was extracted with methyl cellulose, filtered under reduced pressure, and then column purified and recrystallized to obtain compound 10 (3.5 g, yield 65%).

[0206] m / z: 881.33 (100.0%), 882.33 (71.8%), 883.34 (25.5%), 884.34 (6.2%), 885.34 (1.1%)

[0207] Example 2: Synthesis of Compound 34

[0208]

[0209] The synthesis was carried out in the same manner as in Example 1, except that IM2 was used instead of IM1, to thereby synthesize Compound 34 (yield 60%).

[0210] m / z: 897.31 (100.0%), 898.31 (72.7%), 899.31 (26.2%), 900.32 (5.9%), 899.30 (4.5%), 900.31 (3.7%), 901.31 (1.2%), 901.32 (1.1%)

[0211] Example 3: Synthesis of Compound 58

[0212]

[0213] The synthesis was carried out in the same manner as in Example 1, except that IM3 was used instead of IM1, thereby synthesizing Compound 58 (yield 61%).

[0214] m / z: 897.31 (100.0%), 898.31 (72.7%), 899.31 (26.2%), 900.32 (5.9%), 899.30 (4.5%), 900.31 (3.7%), 901.31 (1.2%), 901.32 (1.1%)

[0215] Example 4: Synthesis of Compound 82

[0216]

[0217] The synthesis was carried out in the same manner as in Example 1, except that IM4 was used instead of IM1, to thereby synthesize Compound 82 (yield 66%).

[0218] m / z: 913.28 (100.0%), 914.29 (71.9%), 915.29 (26.6%), 915.28 (9.3%), 91 6.28 (6.6%), 916.29 (6.3%), 917.29 (2.4%), 914.28 (2.0%), 917.30 (1.0%)

[0219] Example 5: Synthesis of Compound 343

[0220]

[0221] The synthesis was carried out in the same manner as in Example 1, and IM5 and N-(4-(dibenzo[b,d]furan-4-yl)phenyl)-[1,1':4',1"-terphenyl]-4-amine were used to replace IM1 and di([1,1':4',1"-terphenyl]-4-yl)amine to synthesize compound 343 (yield 68%).

[0222] m / z: 895.31 (100.0%), 896.31 (72.3%), 897.32 (25.5%), 898.32 (6.4%), 899.32 (1.2%)

[0223] Example 6: Synthesis of Compound 316

[0224]

[0225] The synthesis was carried out in the same manner as in Example 1, and N-(4-(dibenzo[b,d]furan-2-yl)phenyl)-[1,1':4',1"-terphenyl]-4-amine was used instead of di([1,1':4',1"-terphenyl]-4-yl)amine to synthesize compound 316 (yield 70%).

[0226] m / z: 895.31 (100.0%), 896.31 (72.3%), 897.32 (25.5%), 898.32 (6.4%), 899.32 (1.2%)

[0227] Example 7: Synthesis of Compound 105

[0228]

[0229] The synthesis was carried out in the same manner as in Example 1, except that IM6 and N-([1,1'-biphenyl]-4-yl)-[1,1':4',1"-terphenyl]-4-amine were used instead of IM1 and di([1,1':4',1"-terphenyl]-4-yl)amine to synthesize compound 105 (yield 63%).

[0230] m / z: 880.35 (100.0%), 881.35 (71.9%), 882.35 (26.2%), 883.36 (5.9%), 884.36 (1.1%)

[0231] Example 8: Synthesis of Compound 129

[0232]

[0233] The synthesis was carried out in the same manner as in Example 1, except that IM7 and N-([1,1'-biphenyl]-4-yl)-[1,1':4',1"-terphenyl]-4-amine were used instead of IM1 and di([1,1':4',1"-terphenyl]-4-yl)amine to synthesize compound 129 (yield 61%).

[0234] m / z: 880.35 (100.0%), 881.35 (71.9%), 882.35 (26.2%), 883.36 (5.9%), 884.36 (1.1%)

[0235] Example 9: Synthesis of Compound 273

[0236]

[0237] The synthesis was carried out in the same manner as in Example 1, except that IM8 and N-([1,1'-biphenyl]-4-yl)-[1,1':4',1"-terphenyl]-4-amine were used instead of IM1 and di([1,1':4',1"-terphenyl]-4-yl)amine to synthesize compound 273 (yield 60%).

[0238] m / z: 906.40 (100.0%), 907.40 (75.2%), 908.40 (28.0%), 909.41 (6.8%), 910.41 (1.2%)

[0239] Example 10: Synthesis of Compound 549

[0240]

[0241] The synthesis was carried out in the same manner as in Example 1, except that IM9 and N-([1,1'-biphenyl]-4-yl)-[1,1':4',1"-terphenyl]-4-amine were used instead of IM1 and di([1,1':4',1"-terphenyl]-4-yl)amine to synthesize compound 549 (yield 58%).

[0242] m / z: 880.35 (100.0%), 881.35 (71.9%), 882.35 (26.2%), 883.36 (5.9%), 884.36 (1.1%)

[0243] Preparation of organic light-emitting devices

[0244] according to Figure 1 The organic light-emitting device can be prepared by the structure described in the above. The organic light-emitting device can be stacked in order from bottom to top: 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 / second electrode (electron injection electrode 2000) / covering layer 3000.

[0245] exist Figure 1 In the present invention, when preparing an organic light-emitting device, the substrate 10 may be a transparent glass substrate or a flexible plastic substrate.

[0246] The first electrode 1000 is used as an anode for injecting holes into the organic light emitting device. In order to inject holes, a material with a low work function is used, and it can be formed of a transparent material such as indium tin oxide (ITO), indium zinc oxide (IZO), and graphene.

[0247] In the hole injection layer 200 , the hole transport layer 300 , the light emitting layer 400 , and the electron transport layer 500 , a plurality of substances listed in the following Table 2 are used.

[0248] Table 2

[0249]

[0250] The second electrode 2000 for injecting electrons is formed on the electron injection layer 600. Various metals can be used as the second electrode 2000. Specific examples include aluminum, gold, silver and the like.

[0251] Example 11: Preparation of the organic light-emitting device of the present invention

[0252] On an ITO substrate formed with a reflective layer containing Ag, a hole injection layer was formed. HI01 was used to make the film. HATCN was used to form a film as a hole transport layer. After HT01 is formed into a film, 3% BH01:BD01 is doped as the above-mentioned light-emitting layer to Next, as an electron transport layer, After the ET01:Liq (1:1) film was formed, LiF was deposited Next, MgAg was deposited to a thickness of 15 nm as a second electrode, and on the second electrode, a capping layer was formed. The compound prepared in Example 1 was deposited to a thickness of 500 Å. The device was encapsulated in a glove box to prepare an organic light-emitting device.

[0253] Example 12 to Example 20: Preparation of the organic light-emitting device of the present invention

[0254] The same method as in Example 11 was used to prepare an organic light-emitting device having a capping layer formed into a film, using the compounds prepared in Examples 2 to 10 respectively.

[0255] Comparative Examples 1 to 9: Preparation of Organic Light-Emitting Devices

[0256] The same method as in Example 11 was used to prepare organic light-emitting devices having a cover layer formed into a film, respectively, using Ref. 1 to Ref. 9 shown in Table 2.

[0257] Experimental Example 1: Performance evaluation of organic light-emitting devices

[0258] A voltage was applied using a Keithley 2400 source measurement unit to inject electrons and holes, and a Konica Minolta spectroradiometer (CS-2000) was used to measure the brightness of the light. The current density and brightness for the applied voltage were measured under atmospheric pressure conditions to evaluate the performance of the organic light-emitting devices of Examples 11 to 20 and Comparative Examples 1 to 9. The results are shown in Table 3 below.

[0259] Table 3

[0260] Op.V <![CDATA[mA / cm 2 ]]> Cd / A QE(%) CIEx CIE LT97 Embodiment 11 3.94 10 9.01 7.96 0.137 0.049 173 Example 12 3.95 10 9.21 8.10 0.137 0.048 182 Example 13 3.94 10 9.20 8.10 0.137 0.048 185 Embodiment 14 3.94 10 9.23 8.15 0.137 0.048 183 Embodiment 15 3.95 10 9.12 8.02 0.137 0.048 190 Example 16 3.95 10 9.14 8.05 0.138 0.048 192 Embodiment 17 3.95 10 8.90 7.84 0.138 0.050 165 Embodiment 18 3.95 10 8.92 7.85 0.138 0.050 165 Embodiment 19 3.95 10 8.83 7.75 0.138 0.051 154 Embodiment 20 3.95 10 8.85 7.78 0.138 0.051 160 Comparative Example 1 3.95 10 7.88 6.59 0.135 0.055 115 Comparative Example 2 3.95 10 7.35 6.12 0.135 0.056 92 Comparative Example 3 3.95 10 7.30 6.08 0.132 0.060 79 Comparative Example 4 3.96 10 6.02 5.00 0.130 0.067 65 Comparative Example 5 3.95 10 6.90 5.95 0.132 0.059 83 Comparative Example 6 3.96 10 7.32 6.22 0.132 0.060 80 Comparative Example 7 3.95 10 7.50 6.50 0.135 0.055 95 Comparative Example 8 3.95 10 7.62 6.57 0.135 0.055 106 Comparative Example 9 3.96 10 6.75 5.50 0.134 0.064 74

[0261] In Examples 11 to 20 of the present invention compared with Comparative Examples 1 to 8, two carbazoles, dibenzofurans, dibenzothiophenes or anthracenes are linearly bonded to obtain a wide band gap that cannot absorb visible light. At the same time, carbazoles, dibenzofurans, dibenzothiophenes or anthracenes are all bonded to the nitrogen of the amine through an aromatic linking group to maintain a high refractive index, thereby effectively improving color purity and efficiency.

[0262] Compared with Comparative Example 9, the aromatic group bonded to the amine contains at least 2 aromatic (or heteroaromatic) parts, which not only increases the refractive index but also increases the absorption wavelength in the ultraviolet region, so that it can be stable when exposed to external ultraviolet rays, thereby further improving efficiency and having a long life.

[0263] Furthermore, with regard to the various compounds of the present invention, the molecular film arrangement is excellent and an amorphous film can be formed. It can be seen that the lifespan can be increased by blocking external air and moisture. At the same time, due to the high Tg and high Td, the molecular recrystallization can be prevented, and a stable film can be maintained against the heat generated during driving, thereby further improving the lifespan.

[0264] Experimental Example 2: Evaluation of Refractive Index

[0265] Compound 10 (Example 1), Compound 34 (Example 2), Compound 343 (Example 5), and the compound Ref. 1 in Table 2 were used to prepare deposited films with a thickness of 30 nm on a silicon substrate using a vacuum deposition device, and the refractive index at 450 nm was measured using an ellipsometer (JA Woollam Co. Inc, M-2000X). The results are summarized in Table 4 below.

[0266] Table 4

[0267] @450nm Ref.1 Compound 10 Compound 34 Compound 343 Refractive index, n 2.071 2.224 2.230 2.220

[0268] As described in Table 4, it was confirmed that Compound 10, Compound 34, and Compound 343 had a refractive index of 2.1 or more, and more specifically, exhibited a high refractive index of 2.2 or more.

[0269] Experimental Example 3: Evaluation of absorption intensity in the ultraviolet region

[0270] In the ultraviolet region, the compound 343 (Example 5) and the compound Ref.1 in Table 2 were used to prepare a 30 nm thick deposited film on a silicon substrate by means of a vacuum deposition device, and an ellipsometer device (JA Woollam Co. Inc, M-2000X) was used to measure the absorption wavelength in the range of 250 nm to 1000 nm. The results are as follows: Figure 2 as shown in .

[0271] It was confirmed that the absorption intensity of compound 343 was 0.6 or more, specifically 0.7 or more, based on the ultraviolet absorption region of 380 nm, and the absorption intensity was increased by 10% or more, more specifically 20% or more, compared with the Ref. 1 compound.

[0272] The above description of the present invention is for illustrative purposes, and a person skilled in the art of the present invention can understand that the present invention can be easily deformed in other specific ways without changing the technical concept or essential features of the present invention. Therefore, it should be understood that the multiple embodiments described above are illustrative in all implementations, rather than restrictive. For example, each structural element described in a single type can be implemented in a dispersed manner, and similarly, multiple structural elements described as dispersed can also be implemented in a combined manner.

[0273] The scope of the present invention is indicated by the attached claims for protection, rather than the above detailed description. The meaning and scope of the claims for protection and all changes or modifications derived from their equivalent concepts should be interpreted as being included in the scope of the present invention.

Claims

1. A covering layer, characterized in that: The invention comprises a compound represented by the following chemical formula 1: Chemical formula 1 In the chemical formula 1, Each X is independently O, S or CR`R``, each Y is independently O or CR`R``, R` and R`` are each independently methyl or phenyl, wherein R` and R`` may be bonded to form a ring or not, R1 to R4 are each independently hydrogen or deuterium, l and o are each independently 0 or an integer from 1 to 4, m and n are each independently 0 or an integer from 1 to 4, L1 is direct bonding, L2 is phenylene or biphenylene, Ar1 to Ar3 are each independently a phenyl group, a biphenyl group, a terphenyl group, a dibenzofuranyl group, a dibenzothiophenyl group or a combination thereof.

2. The covering layer according to claim 1, characterized in that The chemical formula 1 is represented by the following chemical formula 2: Chemical formula 2 In the chemical formula 2, X, Y, R', R'', R1 to R4, l, m, n, o, L1, Ar1 to Ar3 are as defined in claim 1, R5 is hydrogen, p is an integer of 1 to 2.

3. The covering layer according to claim 2, characterized in that The chemical formula 2 is represented by the following chemical formula 3: Chemical formula 3 In the chemical formula 3, X, Y, R`, R``, R1 to R4, L1, Ar1 to Ar3 and p are as defined in claim 2.

4. The covering layer according to claim 2, characterized in that The chemical formula 2 is represented by one of the following chemical formulas 4 to 6: Chemical formula 4 Chemical formula 5 Chemical formula 6 In the chemical formula 4 to the chemical formula 6, X, Y, R`, R``, R1 to R4, L1, Ar1 to Ar3 and p are as defined in claim 2.

5. The covering layer according to claim 1, characterized in that The X is O or S, and Y is O.

6. The covering layer according to claim 1, characterized in that At least one of Ar1 to Ar3 is a dibenzofuranyl group or a dibenzothiophenyl group.

7. The covering layer according to claim 1, characterized in that At least one of Ar1 to Ar3 includes a terphenyl group.

8. The covering layer according to claim 1, characterized in that The chemical formula 1 is one of the following compounds 1 to 2, 7, 10-54, 151 to 174, 199 to 210, 223 to 270, and 295 to 408:

9. An organic light-emitting device, characterized in that: include: A first electrode and a second electrode; an organic layer, located inside the first electrode and the second electrode; as well as The covering layer according to any one of claims 1 to 8 is arranged outside one or more of the first electrode and the second electrode.

10. The organic light emitting device according to claim 9, characterized in that: The thickness of the covering layer is 300 to

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