High refractive index organic compound, cover material, and light emitting element

Abstract

The present application provides a kind of for improving the luminous efficiency of organic light emitting element and color purity compound, the organic light emitting element material containing the compound, organic light emitting element cover layer material and organic light emitting element.The compound provided by the present application has thiofuran structure, thiazole structure, thiadiazole structure, furan structure, oxazole structure, oxadiazole structure or pyrrole structure on the one hand, and contains a series of aryl, heteroaryl, fused ring aryl, fused ring heteroaryl structure.The organic light emitting element provided by the present application can realize high luminous efficiency and color reproducibility, and the organic light emitting element of the present application can be used for organic EL display, backlight of liquid crystal display, light source of illumination, meter, signboard, identification lamp and the like.The present application provides organic light emitting element with greatly improved luminous efficiency and superior color purity.

Description

Technical Field

[0001] This invention relates to organic compounds for light-emitting elements, coating materials containing the compounds, and light-emitting elements, particularly organic compounds for light-emitting elements, coating materials, and light-emitting elements with significantly improved light extraction efficiency. Background Technology

[0002] Organic light-emitting elements (OLEDs) are self-emissive display devices that feature thinness, wide viewing angles, low power consumption, high contrast, and wide color gamut. With technological advancements, OLEDs can also be designed with flexibility, allowing for bending or folding during use, making products more portable and enabling applications in a wider variety of scenarios.

[0003] The light-emitting principle of organic light-emitting elements (OLEDs) is as follows: by applying a voltage to the element, holes and electrons are generated on the electrodes at both ends. Through conduction in the functional layers, the holes and electrons combine in the light-emitting layer to generate excitons, thereby exciting the light-emitting material. The light-emitting material then returns from the excited state to the ground state, ultimately producing light. These OLEDs have a thin and lightweight structure, can emit high brightness light at low driving voltages, and can emit multiple colors by selecting the light-emitting material, thus attracting considerable attention.

[0004] Since Kodak's CWTang et al. revealed that organic thin-film devices could emit light with high brightness, there has been much research on the application of organic thin-film light-emitting elements. Organic thin-film light-emitting elements are now widely used in mobile phone displays, television displays, smartwatches, VR / AR devices, and other fields, achieving tangible progress in practical application. However, many technical challenges remain, among which improving the luminous efficiency and reducing the power consumption of light-emitting elements are urgent and long-standing issues that need to be addressed.

[0005] Depending on their structure, organic light-emitting devices (OLEDs) can be divided into bottom-emitting and top-emitting structures. In bottom-emitting OLEDs, a reflective electrode is located on the upper part of the organic light-emitting layer, and a transparent electrode is located on the lower part of the organic light-emitting layer, with light directed towards the substrate side. In this case, when the OLED is an active matrix element, the overall light-emitting area is reduced because the thin-film transistors are partially opaque. On the other hand, in top-emitting OLEDs, the transparent electrode is located on the upper part of the organic light-emitting layer, and the reflective electrode is located on the lower part of the organic light-emitting layer. Therefore, the generated light is directed in the opposite direction to the substrate side, increasing the light transmission area and improving brightness.

[0006] In the prior art, in order to improve the luminous efficiency of top-emitting organic light-emitting elements, the method used is to form an organic coating layer above the upper semi-transparent metal electrode through which the light-emitting layer passes, thereby adjusting the optical interference distance and suppressing external light reflection and extinction caused by surface plasma energy movement (see Patent Documents 1-5).

[0007] For example, Patent Document 2 describes forming a film with a refractive index of 1.7 or higher and a film thickness of [missing information] on the upper translucent metal electrode of a top-emitting organic light-emitting element. The organic coating layer improves the luminous efficiency of red and green organic light-emitting elements by approximately 1.5 times. The materials used in the organic coating layer include amine derivatives and quinolinol complexes.

[0008] Patent Document 4 states that materials with a band gap of less than 3.2 eV will affect the emission of blue wavelengths, and therefore are not suitable for use in organic coatings. In Patent Document 4, the organic coating material used is an amine derivative or the like with a specific chemical structure.

[0009] According to Patent Document 5, in order to achieve a blue light-emitting element with a low CIEy value, the organic coating material should have a refractive index change of Δn > 0.08 in the wavelength range of 430-460nm. In Patent Document 5, the organic coating material used is anthracene derivatives with a specific chemical structure, etc.

[0010] Patent documents

[0011] Patent Document 1: WO01 / 039554A1

[0012] Patent Document 2: JP 2006-156390A

[0013] Patent Document 3: JP 2007-103303A

[0014] Patent Document 4: JP 2006-302878A

[0015] Patent Document 5: WO2011 / 043083A1 Summary of the Invention

[0016] As mentioned above, in the prior art, it is known that high-refractive-index organic compounds with specific structures can be used as organic capping layer materials to improve the light extraction efficiency and color purity of top-emitting light-emitting elements. However, the organic capping layers in the prior art do not sufficiently improve light extraction efficiency and cannot provide a solution that simultaneously improves luminous efficiency and color purity.

[0017] To address the aforementioned technical problems, the present invention provides an organic compound for improving the light extraction efficiency and color purity of a light-emitting element, a light-emitting element material containing the organic compound, a light-emitting element capping layer material, and a light-emitting element.

[0018] The organic compounds provided by this invention are characterized by containing, on the one hand, a thiophene structure, a thiazole structure, a thiadiazole structure, a furan structure, an oxazole structure, an oxadiazole structure, or a pyrrole structure, and on the other hand, an aryl, a heteroaryl, a fused-ring aryl, or a fused-ring heteroaryl structure. By simultaneously containing the above two structures, these organic compounds possess superior thin film stability and high refractive index, and can simultaneously improve luminous efficiency and color purity.

[0019] One aspect of the present invention provides an organic compound having the structure shown in general formula 1:

[0020]

[0021] Wherein, X is selected from the group consisting of sulfur atoms, oxygen atoms, N-R1 and C(R2)(R3); wherein, R1, R2, and R3 are independently selected from the group consisting of hydrogen, hydroxyl, alkyl, cycloalkyl, heterocyclic, cycloalkenyl, alkenyl, alkynyl, alkoxy, alkylthio, aryl ether, aryl thioether, aryl, heteroaryl, acyl, carboxylic acid, acyloxy, silyl, alkylamine, arylamine, alkylimino, and arylimino;

[0022] B1 is a nitrogen atom or CR4;

[0023] B2 is a nitrogen atom or CR5;

[0024] R4 and R5 can be the same or different, and can be selected from the group consisting of hydrogen atoms, alkyl, cycloalkyl, heterocyclic, cycloalkenyl, aryl and heteroaryl groups;

[0025] n is an integer greater than or equal to 0;

[0026] m is an integer greater than or equal to 0;

[0027] L1 and L2 can be the same or different, and the group consisting of free aryl and heteroaryl groups is selected.

[0028] Y1 and Y2 can be the same or different, representing the structure shown in General Formula 2 below:

[0029]

[0030] Z is selected from the group consisting of boron atoms, nitrogen atoms, phosphorus atoms, P=O, P=S, carbon atoms, and silicon atoms;

[0031] k is an integer greater than or equal to 2;

[0032] A can be the same or different, and is selected from the group consisting of hydrogen, hydroxyl, alkyl, cycloalkyl, heterocyclic, cycloalkenyl, alkenyl, alkynyl, alkoxy, alkylthio, aryl ether, aryl thioether, aryl, heteroaryl, acyl, carboxylic acid, acyloxy, silyl, alkylamine, arylamine, alkylimino, and arylimino; multiple A's or A and Z can be interconnected, so that one of Y1 and Y2, or both together, forms a polycyclic cycloalkyl, polycyclic heterocyclic, polycyclic cycloalkenyl, fused-ring aryl, or fused-ring heteroaryl.

[0033] Another aspect of the present invention provides a light-emitting element material, characterized in that the material contains the aforementioned organic compound.

[0034] Another aspect of the present invention provides a light-emitting element, characterized in that it comprises a substrate, a first electrode, one or more film layers including a light-emitting layer, a second electrode, and a cover layer; the light-emitting element contains the aforementioned light-emitting element material.

[0035] Another aspect of the present invention provides a light-emitting element cover material, characterized in that: the material contains the above-mentioned organic compound.

[0036] The organic compounds provided by this invention can significantly improve the luminous efficiency and color purity of light-emitting elements. Detailed Implementation

[0037] The specific embodiments of the present invention will be described in detail below.

[0038] First, the organic compounds having the structure of general formula 1 provided by the present invention will be described.

[0039]

[0040] Wherein, X is selected from the group consisting of sulfur atoms, oxygen atoms, N-R1 and C(R2)(R3); wherein, R1, R2, and R3 are independently selected from the group consisting of hydrogen, hydroxyl, alkyl, cycloalkyl, heterocyclic, cycloalkenyl, alkenyl, alkynyl, alkoxy, alkylthio, aryl ether, aryl thioether, aryl, heteroaryl, acyl, carboxylic acid, acyloxy, silyl, alkylamine, arylamine, alkylimino, and arylimino;

[0041] B1 is a nitrogen atom or CR4;

[0042] B2 is a nitrogen atom or CR5;

[0043] R4 and R5 can be the same or different, and can be selected from the group consisting of hydrogen atoms, alkyl, cycloalkyl, heterocyclic, cycloalkenyl, aryl and heteroaryl groups;

[0044] n is an integer greater than or equal to 0;

[0045] m is an integer greater than or equal to 0;

[0046] L1 and L2 can be the same or different, and the group consisting of free aryl and heteroaryl groups is selected.

[0047] Y1 and Y2 can be the same or different, representing the structure shown in General Formula 2 below:

[0048]

[0049] Z is selected from the group consisting of boron atoms, nitrogen atoms, phosphorus atoms, P=O, P=S, carbon atoms, and silicon atoms;

[0050] k is an integer greater than or equal to 2;

[0051] A can be the same or different, and is selected from the group consisting of hydrogen, hydroxyl, alkyl, cycloalkyl, heterocyclic, cycloalkenyl, alkenyl, alkynyl, alkoxy, alkylthio, aryl ether, aryl thioether, aryl, heteroaryl, acyl, carboxylic acid, acyloxy, silyl, alkylamine, arylamine, alkylimino, and arylimino; multiple A's or A and Z can be interconnected, so that one of Y1 and Y2, or both together, forms a polycyclic cycloalkyl, polycyclic heterocyclic, polycyclic cycloalkenyl, fused-ring aryl, or fused-ring heteroaryl.

[0052] The alkyl group is preferably a C1-C20 alkyl group, more preferably a C1-C10 alkyl group, and even more preferably a C1-C6 alkyl group; it is further preferably one or more of saturated aliphatic hydrocarbon groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl or tert-butyl.

[0053] The cycloalkyl group is preferably a C3-C20 cycloalkyl group, more preferably a C3-C12 cycloalkyl group, and even more preferably a C3-C10 cycloalkyl group; it is further preferably one or more of saturated alicyclic hydrocarbon groups such as cyclopropyl, cyclohexyl, norbornyl, or adamantyl.

[0054] The aforementioned heterocyclic group is preferably a C2-C20 heterocyclic group, more preferably a C2-C10 heterocyclic group, and even more preferably a C2-C6 heterocyclic group; it is further preferably one or more of aliphatic rings having atoms other than carbon in the ring, such as pyran ring, piperidine ring, or cyclic amide.

[0055] The aforementioned cycloalkenyl group is preferably a C3-C20 cycloalkenyl group, more preferably a C3-C12 cycloalkenyl group, and even more preferably a C3-C10 cycloalkenyl group; it is further preferably one or more of unsaturated alicyclic hydrocarbon groups containing double bonds, such as cyclopentenyl, cyclopentadienyl, or cyclohexenyl.

[0056] The alkenyl group is preferably a C2-C20 alkenyl group, more preferably a C2-C10 alkenyl group, and even more preferably a C2-C6 alkenyl group; it is further preferably one or more of unsaturated aliphatic hydrocarbon groups containing double bonds, such as vinyl groups.

[0057] The aforementioned alkynyl group is preferably a C2-C20 alkynyl group, more preferably a C2-C10 alkynyl group, and even more preferably a C2-C6 alkynyl group; it is further preferably one or more of the following unsaturated aliphatic hydrocarbon groups containing a triple bond, such as acetylene group.

[0058] The alkoxy group is preferably a C1-C20 alkoxy group, more preferably a C1-C10 alkoxy group, and even more preferably a C1-C6 alkoxy group; it is further preferably one or more of the functional groups such as methoxy, ethoxy, or propoxy that are bonded to aliphatic hydrocarbon groups by ether bonds.

[0059] The above-mentioned alkoxy group is a group in which the oxygen atom of the alkoxy group is replaced by a sulfur atom. The above-mentioned alkoxy group is preferably one or more of C1-C20 alkoxy groups (more preferably C1-C10 alkoxy groups, and even more preferably C1-C6 alkoxy groups).

[0060] The aryl ether group is preferably a C6-C40 aryl ether group, more preferably a C6-C20 aryl ether group, and even more preferably a C6-C10 aryl ether group; further preferably one or more of the functional groups such as phenoxy that are bonded to aromatic hydrocarbon groups by ether bonds.

[0061] The above-mentioned aryl thioether group is a group in which the oxygen atom of the ether bond of the aryl ether group is replaced by a sulfur atom. Preferably, it is a C6-C60 aryl thioether group (more preferably a C6-C40 aryl thioether group, and even more preferably a C6-C20 aryl thioether group).

[0062] The aryl group is preferably a C6-C60 aryl group, more preferably a C6-C40 aryl group, and even more preferably a C6-C20 aryl group; it is further preferably one or more of aromatic hydrocarbon groups such as phenyl, naphthyl, biphenyl, phenanthryl, phenyltriphenyl or pyrene.

[0063] The aforementioned heteroaryl group is preferably a C4-C60 aromatic heterocyclic group, more preferably a C4-C40 aromatic heterocyclic group, and even more preferably a C4-C20 aromatic heterocyclic group; further preferably one or more of furanyl, thiophene, pyrrole, benzofuranyl, benzothiophene, dibenzofuranyl, dibenzothiophene, pyridyl or quinolinyl.

[0064] The acyl group is preferably a C2-C20 acyl group, more preferably a C2-C12 acyl group, and even more preferably a C2-C8 acyl group; it is further preferably one or more of acetyl, benzenesulfonyl, etc.

[0065] The carboxylic acid group is preferably a C2-C20 carboxylic acid group, more preferably a C2-C10 carboxylic acid group, and even more preferably a C2-C6 carboxylic acid group; further preferably one or more of acetic acid group, propionic acid group, butyric acid group, etc.

[0066] The aforementioned acyloxy group is preferably a C2-C20 acyloxy group, more preferably a C2-C10 acyloxy group, and even more preferably a C2-C8 acyloxy group; further preferably one or more of acetoxy, propionyloxy, phenyl acyloxy, etc.

[0067] The aforementioned silane group refers to functional groups having bonds bonded to silicon atoms, such as trimethylsilane, triethylsilane, dimethyl tert-butylsilane, or triphenylsilane. There is no particular limitation on the number of carbon atoms in the silane group; it is typically in the range of 1 to 40, more preferably in the range of 1 to 20, and even more preferably in the range of 1 to 10.

[0068] The alkylamine group is preferably a C1-C20 alkylamine group, more preferably a C1-C10 alkylamine group, and even more preferably a C1-C6 alkylamine group; it is further preferably one or more of methylamino, dimethylaminoamino, methylethylamino, and diethylamino groups.

[0069] The arylamine group is preferably a C6-C60 arylamine group, more preferably a C6-C40 arylamine group, and even more preferably a C6-C20 arylamine group; further preferably one or more of phenylamino, diphenylamino, etc.

[0070] It should be noted that, in this document, the terms "alkyl", "cycloalkyl", "heterocyclic", "alkenyl", "cycloalkenyl", "alkynyl", "alkoxy", "alkthio", "aryl ether", "aryl thioether", "aryl", "heteroaryl", "acyl", "carboxylic acid", "acyloxy", "silylalkyl", "alkylamine", "arylamine", "alkylimino", "arylimino", "cyclocycloalkyl", "polycyclic heterocyclic", "polycyclic cycloalkenyl", "fused-ring aryl", and "fused-ring heteroaryl" include both cases where they are not substituted and cases where they are substituted. Here, "cases where they are substituted" means that the above groups may have substituents without affecting the effect of the present invention.

[0071] The substituents mentioned above are selected from one or more of the following: halogens, C1-C15 alkyl groups, C3-C15 cycloalkyl groups, C3-C15 heterocyclic groups, C2-C15 alkenyl groups, C4-C15 cycloalkenyl groups, C2-C15 alkynyl groups, C1-C55 alkoxy groups, C1-C55 alkylthio groups, C6-C55 aryl ether groups, C6-C55 aryl thioether groups, C6-C55 aryl groups, C4-C55 aromatic heterocyclic groups, acyl groups, carboxyl groups, acyloxy groups, or silane groups having 1-5 silicon atoms in C3-C15.

[0072] Compounds containing thiophene, thioazole, thiadiazole, furan, oxazole, oxadiazole, or pyrrole structures, especially those containing thiophene, furan, or pyrrole structures, exhibit high glass transition temperatures (Tg) and steric hindrance, thus demonstrating superior stability in thin film morphologies. Furthermore, these compounds, particularly those containing thiophene, furan, or pyrrole structures, can enhance absorption and attenuation coefficients, resulting in higher refractive indices in the ultraviolet-visible range.

[0073] Considering the availability of raw materials and ease of synthesis, n and m are preferably 1 or 2, more preferably 2.

[0074] L1 is preferably phenyl, naphthyl, anthracene, pyridyl, pyrazinyl, etc. The connection position of L1 can be any two different positions. For example, in the case of phenyl, the connection position can be (1,2-), (1,3-), or (1,4-).

[0075] L2 is preferably phenyl, naphthyl, anthracene, pyridyl, pyrazinyl, etc. The connection position of L2 can be any two different positions. For example, in the case of pyridyl, the connection positions can be (2,3-), (2,4-), (2,5-), (2,6-), (3,4-), (3,5-), (3,6-).

[0076] From the perspective of obtaining higher luminous efficiency, it is preferable that Y1 and Y2 are selected from the structure shown in Formula 2, and Y1 and Y2 may be the same or different.

[0077]

[0078] Z is selected from boron atom, nitrogen atom, phosphorus atom, P=O, P=S, carbon atom, and silicon atom;

[0079] k is an integer greater than or equal to 2;

[0080] A can be the same or different, and is selected from one of hydrogen, hydroxyl, alkyl, cycloalkyl, heterocyclic, cycloalkenyl, alkenyl, alkynyl, alkoxy, alkylthio, aryl ether, aryl thioether, aryl, heteroaryl, acyl, carboxylic acid, acyloxy, silyl, alkylamine, arylamine, alkylimino, or arylimino; or A can be connected to each other, or A and Z can be connected to each other, so that Y1 and Y2 form one of polycyclic cycloalkyl, polycyclic heterocyclic, polycyclic cycloalkenyl, fused-ring aryl, or fused-ring heteroaryl.

[0081] The alkyl, cycloalkyl, heterocyclic, cycloalkenyl, alkenyl, alkynyl, alkoxy, alkylthio, aryl ether, aryl thioether, aryl, heteroaryl, acyl, carboxylic acid, acyloxy, silylalkyl, alkylamino, arylamino, alkylimino, arylimino, polycyclic cycloalkyl, polycyclic heterocyclic, polycyclic cycloalkenyl, fused-ring aryl, and fused-ring heteroaryl groups are as described above;

[0082] The presence of aryl, heteroaryl, fused-ring aryl, and fused-ring heteroaryl compounds expands the conjugated structure. Simultaneously, the introduction of heteroatoms, particularly boron, nitrogen, phosphorus, P=O, P=S, and silicon atoms, allows the Y1 and Y2 structures to acquire different electron attraction or donation capabilities, making it easier to adjust the peak wavelength of the refractive index. The heteroatoms described in this application have the same meaning as commonly understood in the art, for example, referring to atoms other than carbon in the ring constituting the cyclic group. Therefore, introducing aryl, heteroaryl, fused-ring aryl, fused-ring heteroaryl, and / or further introducing heteroatoms into this series of compounds can effectively increase the refractive index of the compounds, thereby effectively improving the light extraction efficiency of organic light-emitting elements.

[0083] Therefore, from the perspective of improving the refractive index, Y1 is preferably quinoxalinyl, quinolinyl, isoquinolinyl, phenantholinyl, phenothiazinyl, phenotoxazinyl, acridinoneyl, phthalimideyl, benzotriazoleyl, benzimidazoleyl, diphenylphosphine oxide, indolyl, benzozolinoneyl, benzothiazolinoneyl, mercaptobenzoxazolyl, mercaptobenzothiazolinyl, or diindenoneyl, etc. The linkage position of Y1 can be any position; for example, in the case of quinolinyl, any one of 2-quinolinyl, 3-quinolinyl, 4-quinolinyl, 5-quinolinyl, 6-quinolinyl, 7-quinolinyl, or 8-quinolinyl is acceptable.

[0084] Y2 is preferably composed of quinoxalinyl, quinolinyl, isoquinolinyl, phenantholinyl, phenothiazinyl, phenotoxazinyl, acridinoneyl, phthalimideyl, benzotriazolyl, benzimidazolyl, diphenylphosphine oxide, indolyl, benzozolinoneyl, benzothiazolinoneyl, mercaptobenzoxazolyl, mercaptobenzothiazolinyl, or diindenoneyl, etc. The linkage position of Y2 can be any position; for example, in the case of isoquinolinyl, any one of 1-isoquinolinyl, 3-isoquinolinyl, 4-isoquinolinyl, 5-isoquinolinyl, 6-isoquinolinyl, 7-isoquinolinyl, or 8-isoquinolinyl is acceptable.

[0085] Preferably, X in Formula 1 is a sulfur atom, an oxygen atom, or an N-R1 atom. In this case, since X has a lone pair of electrons, its polarizability can be increased for the overall structure, thereby further increasing the refractive index of the compound. Furthermore, the presence of sulfur atoms, oxygen atoms, and an N-R1 structure allows the maximum absorption wavelength of the compound to be controlled outside the blue light absorption range, while keeping the peak refractive index wavelength within the blue light range, thus further improving luminous efficiency while avoiding a decrease in color purity. Therefore, X in Formula 1 is preferably a sulfur atom, an oxygen atom, or an N-R1 atom. Considering raw material costs and production convenience, its structural units are preferably: thiophene group, thiazolyl group, thiadiazol group, thiophene group, oxazol group, oxadiazol group, 1-methylpyrrole, 1-phenylpyrrole, etc.

[0086] It should be noted that the terms "quinoxolinyl", "quinolinyl", "isoquinolinyl", "phenantholinyl", "phenothiazinyl", "phenotoxazinyl", "acridoneyl", "phthalimideyl", "benzotriazoleyl", "benzimidazoleyl", "diphenylphosphine oxide", "indolyl", "benzozolinoneyl", "benzothiazolinoneyl", "mercaptobenzoxazolyl", "mercaptobenzothiazolinoneyl", "diindenoneyl", "thiophenyl", "thiazolyl", "thiadiazoleyl", "thiophenyl", "oxazolyl", "oxadiazoleyl", "1-methylpyrrole", and "1-phenylpyrrole" include both unsubstituted and substituted cases. Here, "substituted cases" means that the above groups may have substituents without affecting the effect of the present invention.

[0087] The substituents mentioned above may be selected from one or more of the following: halogens, C1-C15 alkyl groups, C3-C15 cycloalkyl groups, C3-C15 heterocyclic groups, C2-C15 alkenyl groups, C4-C15 cycloalkenyl groups, C2-C15 alkynyl groups, C1-C55 alkoxy groups, C1-C55 alkoxy-thiol groups, C6-C55 aryl ether groups, C6-C55 aryl thioether groups, C6-C55 aryl groups, C4-C55 aromatic heterocyclic groups, acyl groups, carboxyl groups, acyloxy groups, or silane groups having 1-5 silicon atoms from C3-C15.

[0088] The compounds described in this invention are not particularly limited as long as they satisfy the above structure; preferred examples are listed below:

[0089]

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097]

[0098]

[0099]

[0100]

[0101]

[0102] The compound of general formula 1 in this invention can be used alone, or in combination of two or more, or in layers, or in combination with other materials or in layers in organic light-emitting elements.

[0103] The compounds of the present invention have been described in detail above. The mechanism of the present invention can be considered as follows (but not to limit the invention in any way): The compounds provided by the present invention, containing thiophene, thiazole, thiadiazole, furan, oxazole, oxadiazole, or pyrrole structures, have high glass transition temperatures (Tg) and steric hindrance effects, thus exhibiting superior stability in thin film morphology. Simultaneously, the thiophene, thiazole, thiadiazole, furan, oxazole, oxadiazole, or pyrrole structures can improve the absorption coefficient and attenuation coefficient. Higher absorption and attenuation coefficients (k) correspond to higher refractive indices, resulting in higher refractive indices in the ultraviolet-visible range. Furthermore, the presence of aryl, heteroaryl, fused-ring aryl, and fused-ring heteroaryl groups expands the conjugated structure. Moreover, the preferred introduction of heteroatoms, particularly boron, nitrogen, phosphorus, P=O, P=S, and silicon atoms, allows the Y1 and Y2 structures to acquire different electron attraction or donation capabilities, making it easier to adjust the peak wavelength of the refractive index. Therefore, introducing aryl, heteroaryl, fused-ring aryl, fused-ring heteroaryl and / or further introducing heteroatoms into this series of compounds can effectively increase the refractive index of the compounds, thereby effectively improving the light extraction efficiency of organic light-emitting elements.

[0104] Therefore, by using the compounds of the present invention in the capping material, a capping layer with a high refractive index can be obtained, thereby obtaining an organic light-emitting element with significantly improved light extraction efficiency and superior color purity.

[0105] The embodiments of the organic light-emitting element material, organic light-emitting element, and organic light-emitting element cover layer material provided by the present invention will be described in detail below.

[0106] The present invention also provides an organic light-emitting element material containing the compounds described above. The organic light-emitting element of the present invention comprises: a substrate, a first electrode, a light-emitting layer containing one or more organic films, a second electrode, and a capping layer; the organic light-emitting element contains the organic light-emitting element material described above. The present invention further provides an organic light-emitting element capping layer material containing the compounds described above and the following compounds:

[0107]

[0108] The aforementioned compounds achieve a high refractive index based on the thiophene structure, while also expanding the range of conjugated molecular systems. The various groups on the outer side of the molecule exhibit significant effects in modulating the absorption wavelength. Theoretical calculations and practical tests demonstrate that these compounds, as capping layer materials, significantly improve the light extraction efficiency of light-emitting elements.

[0109] The embodiments of the organic light-emitting element of the present invention are described in detail below. The organic light-emitting element of the present invention is an organic light-emitting element containing the compound described in the present invention. The organic light-emitting element has a structure comprising, in sequence, a substrate, a first electrode, one or more organic layers including a light-emitting layer, a second electrode through which light emitted from the aforementioned light-emitting layer passes, and a light extraction efficiency improvement layer (i.e., a capping layer). The light-emitting layer emits light through electrical energy.

[0110] In the light-emitting element of the present invention, the substrate used is preferably a glass substrate such as soda glass or alkali-free glass. Regarding the thickness of the glass substrate, any thickness sufficient to maintain mechanical strength is acceptable; therefore, 0.5 mm or more is sufficient. Regarding the glass material, since fewer ions leached from the glass are better, alkali-free glass is preferred. Alternatively, commercially available glass coated with a protective coating such as SiO2 can also be used. Furthermore, if the first electrode functions stably, the substrate does not necessarily have to be glass; for example, the anode can be formed on a plastic substrate.

[0111] The material used in the first electrode is preferably a metal with high refractive index properties, such as gold, silver, or aluminum, or a metal alloy such as an APC-based alloy. These metals or metal alloys can also be multilayered structures. In addition, transparent conductive metal oxides such as tin oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO) can be stacked on top of and / or under the metal, metal alloy, or their laminates.

[0112] The material used in the second electrode is preferably a material that can form a translucent or transparent film that allows light to pass through. Examples include silver, magnesium, aluminum, calcium, or alloys of these metals, as well as transparent conductive metal oxides such as tin oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO). These metals, alloys, or metal oxides can also be multilayered structures.

[0113] The aforementioned electrodes can be formed using methods such as resistance heating evaporation, electron beam evaporation, sputtering, ion sputtering, or photoresist coating, without particular limitations. Furthermore, depending on the work function of the materials used, one of the first and second electrodes functions as the anode relative to the organic film layer, while the other functions as the cathode.

[0114] Besides consisting solely of a light-emitting layer, the organic layer can also be a stacked structure comprising: 1) a hole transport layer / light-emitting layer; 2) a light-emitting layer / electron transport layer; 3) a hole transport layer / light-emitting layer / electron transport layer; 4) a hole injection layer / hole transport layer / light-emitting layer / electron transport layer; and 5) a hole injection layer / hole transport layer / light-emitting layer / electron transport layer / electron injection layer. Furthermore, each of the above layers can be a single-layer structure or a multi-layer structure. Preferably, when structures 1) to 5) are used, the anode-side electrode is bonded to the hole input layer or the hole transport layer, and the cathode-side electrode is bonded to the electron input layer or the electron transport layer.

[0115] Hole transport layers can be formed by stacking or mixing one or more hole transport materials, or by using a mixture of hole transport materials and polymer binders. The hole transport materials need to efficiently transport holes from the positive electrode between electrodes under an applied electric field; therefore, high hole injection efficiency and efficient transport of injected holes are desirable. Consequently, the hole transport materials must possess appropriate ionic potential, high hole mobility, and excellent stability, and be resistant to the formation of impurities that could become traps during manufacturing and use. There are no particular limitations on substances that meet these conditions. Examples include 4,4'-bis(N-(3-methylphenyl)-N-phenylamino)biphenyl (TPD), 4,4'-bis(N-(1-naphthyl)-N-phenylamino)biphenyl (also known as N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4'-diamine, abbreviated as NPD), 4,4'-bis(N,N-bis(4-biphenyl)amino)biphenyl (also known as N,N,N',N'-tetra(4-biphenyl)diaminobiphenyl, abbreviated as TBDB), bis(N,N-diphenyl-4-phenylamino)-N,N-diphenyl-4,4'-diamino-1,1'-biphenyl (TPD232), and other benzidines, 4,4',4'-tris(3-methyl) Materials in the group called star-shaped triarylamines, such as phenyl(phenyl)amino)triphenylamine (m-MTDATA) and 4,4',4”-tris(1-naphthyl(phenyl)amino)triphenylamine (1-TNATA), with a carbazole skeleton, are preferred. Carbazole polymers are particularly preferred, including dicarbazole derivatives such as di(N-arylcarbazole) or di(N-alkylcarbazole), tricarbazole derivatives, tetracarbazole derivatives, triphenyl compounds, pyrazoline derivatives, stilbene compounds, hydrazine compounds, benzofuran derivatives, thiophene derivatives, oxadiazole derivatives, phthalocyanine derivatives, porphyrin derivatives, and other heterocyclic compounds or fullerene derivatives. In polymer systems, polycarbonate or styrene derivatives, polythiophene, polyaniline, polyfluorene, polyvinylcarbazole, and polysilanes with the above monomers on their side chains are also preferred. In addition, inorganic compounds such as p-type Si and p-type SiC can also be used.

[0116] A hole injection layer can be provided between the anode and the hole transport layer. By providing a hole injection layer, the organic light-emitting element can achieve a low driving voltage and improve its lifespan. The hole injection layer is generally preferably made of a material with a lower ionic potential than the hole transport layer material. Specifically, it can be, for example, a benzidine derivative such as TPD232, a star-shaped triarylamine material group, or a phthalocyanine derivative. Furthermore, it is preferable that the hole injection layer is composed solely of an acceptor compound, or that the acceptor compound is doped into another hole transport layer. Examples of acceptor compounds include metal chlorides such as ferric chloride (III), aluminum chloride, gallium chloride, indium chloride, and antimony chloride; metal oxides such as molybdenum oxide, vanadium oxide, tungsten oxide, and ruthenium oxide; and charge-transfer coordination compounds such as tris(4-bromophenyl)hexachloroantimonate (TBPAH). Additionally, it can also be organic compounds, quinone compounds, acid anhydride compounds, fullerenes, etc., that have an intramolecular nitro, cyano, halogen, or trifluoromethyl groups.

[0117] In this invention, the light-emitting layer can be a single-layer or multi-layer structure, and each layer can be formed using light-emitting materials (main material and dopant material). It can be a mixture of main material and dopant material, or only the main material; either is acceptable. That is, in each light-emitting layer of the light-emitting element of this invention, only the main material or only the dopant material emits light, or both the main material and the dopant material emit light together. From the perspective of efficiently utilizing electrical energy and obtaining high color purity light emission, it is preferable that the light-emitting layer is a mixture of main material and dopant material. Furthermore, the main material and dopant material can each be one type, or a combination of multiple types; either is acceptable. The dopant material can be added to the entire main material or to a portion of it; either is acceptable. The dopant material can be layered or dispersed; either is acceptable. The dopant material can control the emission color. Excessive amounts of dopant material will cause concentration extinction; therefore, its amount relative to the main material is preferably 20% by weight or less, more preferably 10% by weight or less. The doping method can be a co-evaporation method with the main material, or a method of pre-mixing with the main material and then simultaneously evaporating.

[0118] Specifically, as a luminescent material, it can be anthracene, pyrene and other fused-ring derivatives known as luminescent bodies in the past, metal chelate hydroxyquinoline compounds such as tris(8-hydroxyquinoline)aluminum, dibenzofuran derivatives, carbazole derivatives, indolecarbazole derivatives, polyphenylene vinylidene derivatives, poly-p-phenylene derivatives and polythiophene derivatives in polymers, etc., without particular limitation.

[0119] There are no particular limitations on the main material contained in the luminescent material. Compounds or their derivatives with fused aromatic rings such as anthracene, phenanthrene, pyrene, benzo[9,10]phenanthrene, tetraphenyl, perylene, benzo[9,10]phenanthrene, fluoranthene, and indene, aromatic amine derivatives such as N,N'-dinathyl-N,N'-diphenyl-4,4'-diphenyl-1,1'-diamine, metal chelate hydroxyquinoline compounds such as tris(8-hydroxyquinoline)aluminum, pyrrolopyrrole derivatives, dibenzofuran derivatives, carbazole derivatives, indolecarbazole derivatives, and triazine derivatives can be used. In the polymer, polyphenylene vinylidene derivatives, polyp-phenylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, and polythiophene derivatives can be used without particular limitation.

[0120] Furthermore, there are no particular restrictions on the doping materials, and examples include compounds with fused aromatic rings such as naphthalene, anthracene, phenanthrene, pyrene, benzo[9,10]phenanthrene, perylene, benzo[9,10]phenanthrene, fluorene, indene, etc., or their derivatives (e.g., 2-(benzothiazol-2-yl)-9,10-diphenylanthracene), furan, pyrrole, thiophene, thiophene, 9-silazine, 9,9'-spirodisilazine, benzothiophene, benzofuran, indole, dibenzothiophene, and dibenzofuran. Compounds with heterocyclic aromatic rings, such as imidazopyridine, phenanthrene, pyridine, pyrazine, naphthidine, quinoxaline, pyrrolopyridine, thioxanthium, etc., or their derivatives; borane derivatives; stilbene derivatives; aminostyryl derivatives; pyrrolomethyl derivatives; diketopyrrolo[3,4-c]pyrrole derivatives; coumarin derivatives; azole derivatives such as imidazolium, thiazole, thiadiazole, carbazole, oxazole, oxadiazole, triazole, etc.; and aromatic amine derivatives, etc.

[0121] In addition, phosphorescent materials can also be doped into the light-emitting layer. The phosphorescent material is one that can phosphore at room temperature. When using a phosphorescent material as a dopant, it is preferable that it can phosphore substantially at room temperature, but this is not particularly limited; preferably, it contains an organometallic complex selected from at least one metal chosen from indium, ruthenium, rhodium, palladium, platinum, osmium, and rhenium. From the perspective of high phosphorescence efficiency at room temperature, organometallic complexes containing indium or platinum are more preferred. As a host material used in combination with phosphorescent dopants, indole derivatives, carbazole derivatives, indolocarbazole derivatives, nitrogen-containing aromatic compound derivatives with pyridine, pyrimidine, or triazine skeletons, polyarylbenzene derivatives, spirofluorene derivatives, tri-indene, benzo[9,10]phenanthrene and other aromatic hydrocarbon compound derivatives, dibenzofuran derivatives, dibenzothiophene and other compounds containing oxogroup elements, and organometallic complexes such as hydroxyquinoline beryllium complexes can be used well. However, there are no particular limitations as long as the triplet energy is greater than that of the dopant used and electrons and holes can be smoothly injected or transported from their respective transport layers. In addition, it can contain two or more triplet luminescent dopants, and it can also contain two or more host materials. Furthermore, it can also contain one or more triplet luminescent dopants and one or more phosphorescent dopants.

[0122] In this invention, the electron transport layer is a layer through which electrons are injected from the cathode and then transported. The electron transport layer preferably has high electron injection efficiency and can efficiently transport the injected electrons. Therefore, the electron transport layer is preferably composed of a material with high electron affinity and mobility, excellent stability, and is less likely to generate impurities that could become traps during manufacturing and use. However, considering the balance of hole and electron transport, if the electron transport layer primarily functions to efficiently prevent holes from the anode from recombinizing and flowing to the cathode side, then even if it is composed of a material with relatively low electron transport capability, the effect of improving luminous efficiency will be comparable to that of a material with high electron transport capability. Therefore, in the electron transport layer of this invention, a hole blocking layer that can efficiently prevent hole migration is also included as an equivalent.

[0123] There are no particular limitations on the electron transport materials used in the electron transport layer. Examples include fused aromatic ring derivatives such as naphthalene and anthracene, styrene-based aromatic ring derivatives represented by 4,4'-bis(diphenylvinyl)biphenyl, quinone derivatives such as anthraquinone and biphenylquinone, phosphine oxide derivatives, hydroxyquinoline complexes such as tris(8-hydroxyquinoline)aluminum, benzo(hydroxyquinoline) complexes, hydroxyazole complexes, azomethyl base complexes, cycloheptatrienolone metal complexes, or flavonol metal complexes. From the perspective of reducing the driving voltage and obtaining high-efficiency luminescence, compounds with heterocyclic aromatic ring structures are preferred. The heterocyclic aromatic ring structure is composed of elements selected from carbon, hydrogen, nitrogen, oxygen, silicon, and phosphorus and contains electron-withdrawing nitrogen.

[0124] Heteroaromatic rings containing electron-withdrawing nitrogen exhibit high electrophilicity. Electron transport materials containing electron-withdrawing nitrogen readily accept electrons from cathodes with high electrophilicity, thereby reducing the driving voltage of the light-emitting element. Furthermore, the increased electron supply to the light-emitting layer and the increased probability of recombination in the light-emitting layer lead to improved luminous efficiency. Examples of heteroaromatic rings containing electron-withdrawing nitrogen include, for example, pyridine rings, pyrazine rings, pyrimidine rings, quinoline rings, quinoxaline rings, naphthidine rings, pyrimidine-pyrimidine rings, benzoquinoline rings, phenanthrene-rhein rings, imidazole rings, oxazole rings, oxadiazole rings, triazole rings, thiazole rings, thiadiazole rings, benzoxazole rings, benzothiazole rings, benzimidazole rings, or phenanthrene-imidazolium rings.

[0125] Furthermore, examples of compounds possessing these heterocyclic aromatic ring structures include, for instance, benzimidazole derivatives, benzoxazole derivatives, benzothiazole derivatives, oxadiazole derivatives, thiadiazole derivatives, triazole derivatives, pyrazine derivatives, phenanthroline derivatives, quinoxaline derivatives, quinoline derivatives, benzoquinoline derivatives, and oligopyridine derivatives such as bipyridine and terpyridine. When these derivatives possess a fused aromatic ring skeleton, the glass transition temperature increases, and the electron mobility increases, thereby enhancing the effect of reducing the driving voltage of the light-emitting element, and thus they are preferred. Moreover, considering the improvement of the light-emitting element's lifespan, ease of synthesis, and availability of raw materials, it is preferable that the aforementioned fused aromatic ring skeleton is an anthracene skeleton, a pyrene skeleton, or a phenanthroline skeleton.

[0126] The aforementioned electron transport materials can be used alone, or two or more of the aforementioned electron transport materials can be used in combination, or one or more other electron transport materials can be mixed into the aforementioned electron transport materials. Additionally, donor compounds can be added. Here, a donor compound refers to a compound that improves the electron injection barrier, thereby facilitating the injection of electrons from the cathode or electron injection layer into the electron transport layer, and thus improving the electrical conductivity of the electron transport layer. Preferred examples of donor compounds for this invention include: alkali metals, inorganic salts containing alkali metals, complexes of alkali metals and organic compounds, alkaline earth metals, inorganic salts containing alkaline earth metals, or complexes of alkaline earth metals and organic compounds. Preferred types of alkali metals or alkaline earth metals include alkali metals such as lithium, sodium, or cesium, which have low work functions and are highly effective in improving electron transport capabilities, or alkaline earth metals such as magnesium or calcium.

[0127] In this invention, an electron injection layer may also be provided between the cathode and the electron transport layer. Typically, the electron injection layer is inserted to facilitate the injection of electrons from the cathode into the electron transport layer. When inserted, a compound containing an electron-withdrawing nitrogen heterocyclic structure can be used, or a layer containing the aforementioned donor compound can be used. Furthermore, inorganic materials that are insulators or semiconductors can also be used in the electron injection layer. Using these materials effectively prevents short circuits in the light-emitting element and improves electron injection performance, and is therefore preferred. As these insulators, at least one metal compound selected from alkali metal chalcogenides, alkaline earth metal chalcogenides, alkali metal halides, and alkaline earth metal halides is preferred. Additionally, complexes of organic compounds and metals can also be used well.

[0128] Methods for forming the aforementioned layers constituting the light-emitting element include resistance heating evaporation, electron beam evaporation, sputtering, molecular stacking, or coating, etc., without particular limitations. However, from the perspective of element characteristics, resistance heating evaporation or electron beam evaporation is generally preferred.

[0129] The thickness of the organic layer varies depending on the resistivity of the luminescent material and is not particularly limited, but is preferably 1 to 1000 nm. The film thicknesses of the luminescent layer, electron transport layer, and hole transport layer are preferably 1 nm to 200 nm, and more preferably 5 nm to 100 nm.

[0130] The light extraction efficiency improvement layer of the present invention contains compounds having the above-mentioned thiophene, thioazole, thiadiazole, furan, oxazole, oxadiazole, or pyrrole structures, preferably compounds having the above-mentioned thiophene, furan, or pyrrole structures. To maximize luminous efficiency and achieve color reproducibility, it is preferable to stack the above-mentioned compounds having the thiophene, thioazole, thiadiazole, furan, oxazole, oxadiazole, or pyrrole structures with a thickness of 20 nm to 120 nm. More preferably, the stacking thickness is 40 nm to 80 nm. Furthermore, from the perspective of maximizing luminous efficiency, it is more preferable that the thickness of the light extraction efficiency improvement layer is 50 nm to 70 nm.

[0131] There are no particular limitations on the formation method of the light extraction efficiency improvement layer. Examples include resistance heating evaporation, electron beam evaporation, sputtering, molecular layering, coating, inkjet printing, doctor blade printing, and laser transfer. Evaporation is the most popular method. However, substances that easily crystallize during this process can affect the overall performance of the device.

[0132] The light-emitting element of this invention has the function of converting electrical energy into light. Here, direct current is mainly used as the electrical energy, but pulsed current or alternating current can also be used. There are no particular limitations on the current and voltage values, but considering the power consumption and lifespan of the element, it should be selected in a way that can obtain the maximum brightness with the lowest possible energy.

[0133] The light-emitting element of the present invention can be well used as a flat panel display that displays information in, for example, a matrix and / or field manner.

[0134] Matrix display refers to the arrangement of pixels in a two-dimensional grid or mosaic pattern to display text or images. The shape and size of the pixels depend on the application. For example, in the image and text display of computers, monitors, and televisions, quadrilateral pixels with side lengths of less than 300μm are typically used. In large displays such as display panels, pixels with side lengths in the millimeter range are used. In monochrome displays, simply arranging pixels of the same color is sufficient, but in color displays, red, green, and blue pixels are arranged. Typical patterns in this case are triangular and striped. Furthermore, the matrix can be driven by either line-by-line driving or an active matrix. While line-by-line driving is simpler in construction, active matrices sometimes offer superior operational characteristics; therefore, flexible application is necessary.

[0135] The field method in this invention refers to a method of forming a pattern, illuminating an area defined by the arrangement of the pattern, and thereby displaying predetermined information. Examples include: time and temperature displays in digital clocks and thermometers, operating status displays in audio equipment and induction cookers, and panel displays in automobiles. Furthermore, the matrix display and the field display can coexist on the same panel.

[0136] The light-emitting element of the present invention is preferably used as an illumination source, and can provide a light source that is thinner and lighter than existing light sources and can emit light from a surface.

[0137] Example

[0138] The present invention will now be described in more detail with reference to specific embodiments. However, the following embodiments are only for the purpose of enabling those skilled in the art to understand the concept of the present invention and are not intended to limit the scope of the present invention.

[0139] 1 H-NMR spectra were determined using a JEOL (400MHz) nuclear magnetic resonance spectrometer.

[0140] Synthesis and preparation examples

[0141] The present invention is illustrated below with examples of synthesis and preparation, but the present invention is not limited to these examples. Furthermore, the designations of the compounds in the following examples of synthesis and preparation refer to the designations of the compounds described above.

[0142] Synthesis example 1

[0143] Synthesis of compound

[001]

[0144] Under a nitrogen atmosphere, 4.59 g of 2,5-bis[4-(4-chloro-phenyl)-5-pyridin-2-]thiophene, 4.00 g of phenothiazine, 2.11 g of sodium tert-butoxide, 0.11 g of bis(dibenzylideneacetone)palladium, 0.19 g of 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl, and 200 ml of xylene were added to the reactor and stirred under reflux for 24 h. After cooling to room temperature, the mixture was filtered, and the filter cake was washed with 50 ml of toluene and 200 ml of water twice. After filtration, the filter cake was washed twice with 200 ml of methanol and filtered again. The mixture was then dried under vacuum to obtain 7.12 g of the compound [1].

[0145] 1 HNMR(DMSO):6.55(d,4H),6.7-7.0(m,16H),7.01(d,2H),7.25(d,4H),7.71(d,2H),8.02(d,2H),8.91(d,2H).

[0146] Synthesis example 2

[0147] Synthesis of compound

[004]

[0148] Except for the substitution of 2,5-bis(4'-chloro-biphenyl-4-)thiophene for 2,5-bis[4-(4-chloro-phenyl)-5-pyridin-2-]thiophene, the rest of the synthetic steps were the same as those for compound [1]. 7.02 g of compound [4] was obtained.

[0149] 1 HNMR(DMSO):6.52(d,4H),6.7-7.0(m,18H),7.00(d,2H),7.2-7.6(m,12H).

[0150] Synthesis example 3

[0151] Synthesis of compound

[022]

[0152] Except for the substitution of 2,5-bis[4-(4-chloro-phenyl)-naphthiophene for 2,5-bis[4-(4-chloro-phenyl)-5-pyridine-2-]thiophene, the rest of the synthetic steps were the same as those for compound [1]. 7.53 g of compound

[22] was obtained.

[0153] 1HNMR(DMSO):6.53(d,4H),6.7-7.0(m,16H),6.98(d,2H),7.2-7.7(m,14H).

[0154] Synthesis example 4

[0155] Synthesis of compound

[067]

[0156] Under a nitrogen atmosphere, 4.43 g of 2,5-bis[4-(4-chloro-phenyl)-5-pyridine-2-]furan, 4.00 g of phenothiazine, 2.11 g of sodium tert-butoxide, 0.11 g of bis(dibenzylacetone)palladium, 0.19 g of 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl, and 200 ml of xylene were added to a reactor and stirred under reflux for 8 h. After cooling to room temperature, the mixture was filtered, the solvent was removed by vacuum distillation, and the mixture was washed twice with 200 ml of water. After filtration, the filter cake was washed twice with 200 ml of methanol, filtered, and the filter cake was rinsed with 50 ml of toluene. The resulting toluene solution was washed twice with 200 ml of water, separated, and the organic phase was evaporated to dryness under vacuum to obtain 4.31 g of the compound

[067] .

[0157] 1 HNMR(DMSO):6.25(d,2H),6.57(d,4H),6.7-7.0(m,16H),7.21(d,4H),7.72(d,2H),8.01(d,2H),8.93(d,2H).

[0158] Synthesis example 5

[0159] Synthesis of compound

[162]

[0160] Except for the substitution of phenothiazine with diphenylphosphine oxyphosphate and the substitution of 2,5-bis[4-(4-chloro-phenyl)-5-pyridin-2-]thiophene with 2,5-bis[4-(4-chloro-phenyl)-5-pyridin-2-]furan, the rest of the synthetic steps were the same as those for compound

[067] . 3.12 g of compound

[162] was obtained.

[0161] 1 HNMR(DMSO):7.05(d,2H),7.2-7.6(m,28H),7.71(d,2H),8.05(d,2H),8.93(d,2H).

[0162] Synthesis example 6

[0163] Synthesis of compound

[151]

[0164] Except for the substitution of phenothiazine with diphenylphosphine oxychloride and the substitution of 2,5-bis[4-(4-chloro-phenyl)-5-pyridine-2-]furan with 2,5-bis[4-(4-chloro-phenyl)-5-pyridine-2-]furan, the rest of the synthetic steps were the same as those for compound

[067] . 4.05 g of compound

[151] was obtained.

[0165] 1 HNMR(DMSO):6.21(d,2H),7.2-7.6(m,36H).

[0166] Synthesis Example 7

[0167] Synthesis of compound

[220]

[0168] Under a nitrogen atmosphere, 4.57 g of 2,5-bis(4'-chloro-biphenyl-4-)thiophene, 2.38 g of benzotriazole, 2.11 g of sodium tert-butoxide, 0.22 g of bis(dibenzylacetone)palladium, 0.40 g of 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl, and 200 ml of xylene were stirred and refluxed in a reactor for 24 h. After cooling to room temperature, the mixture was filtered, and the filter cake was washed with 50 ml of toluene. The resulting toluene solution was washed twice with 200 ml of water. The mixture was separated, the organic phase was evaporated to dryness, and refluxed with 10 mL of xylene for 2 h. After filtration, the filter cake was washed with 10 mL of xylene and dried under vacuum to obtain 5.66 g of the compound

[220] .

[0169] 1 HNMR(DMSO):7.00(d,2H),7.2-8.0(m,24H).

[0170] Synthesis example 8

[0171] Synthesis of compound

[250]

[0172] Except for the substitution of benzotriazole with phthalimide and 2,5-bis(4'-chloro-biphenyl-4-)thiazole with 2,5-bis(4'-chloro-biphenyl-4-)thiophene, the rest of the synthetic steps were the same as those for compound

[220] . 5.48 g of compound

[250] was obtained.

[0173] 1 HNMR(DMSO):7.3-7.6(m,16H),7.83(m,8H),8.17(s,1H).

[0174] Synthesis example 9

[0175] Synthesis of compound

[286]

[0176] Under a nitrogen atmosphere, 4.57 g of 2,5-bis(4'-chloro-biphenyl-4-)thiophene, 5.10 g of pinacol quinoline-4-borate, 3.18 g of sodium carbonate, 0.14 g of bis(triphenylphosphine)palladium dichloride, 120 mL of ethylene glycol dimethyl ether, and 40 mL of water were stirred and refluxed in a reactor for 12 h. After cooling to room temperature, the mixture was filtered, and the filter cake was washed with 50 mL of ethylene glycol dimethyl ether, then washed three times with 200 mL of water with stirring. After filtration, the filter cake was dried under vacuum to obtain 5.71 g of the compound

[286] .

[0177] 1 HNMR(DMSO):7.10(d,2H),7.2-7.8(m,24H),8.12(d,2H),8.89(d,2H).

[0178] Synthesis example 10

[0179] Synthesis of compound

[302]

[0180] Except for the substitution of quinoline-4-boronic acid for pinacol ester, the rest of the synthetic steps were the same as those for compound

[286] . 5.32 g of compound

[302] was obtained.

[0181] 1 HNMR(DMSO):7.12(d,2H),7.2-7.6(m,16H),7.7(m,8H),8.81(d,2H).

[0182] Synthesis example 11

[0183] Synthesis of compound

[359]

[0184] Except for the substitution of 2,5-bis(4'-chloro-biphenyl-4-)thiadiazole for 2,5-bis(4'-chloro-biphenyl-4-)thiophene, the rest of the synthetic steps were the same as those for compound

[286] . 5.21 g of compound

[359] was obtained.

[0185] 1 HNMR(DMSO):7.2-7.6(m,24H),8.01(d,2H),8.90(d,2H).

[0186] Synthesis example 12

[0187] Synthesis of compound

[398]

[0188] Except for the substitution of quinoline-4-boronic acid for pinacol ester, the rest of the synthetic steps were the same as those for compound

[286] . 5.01 g of compound

[398] was obtained.

[0189] 1 HNMR(DMSO):7.03(d,2H),7.2-7.6(m,26H).

[0190] Synthesis example 13

[0191] Synthesis of compound

[399]

[0192] Except for the substitution of pentafluorophenylboronic acid for pinacol quinoline-4-boronic acid, the rest of the synthetic steps were the same as those for compound

[286] . 6.58 g of compound

[399] was obtained.

[0193] 1 HNMR(DMSO):7.07(d,2H),7.2-7.6(m,16H).

[0194] Synthesis example 14

[0195] Synthesis of compound

[400]

[0196] Under a nitrogen atmosphere, 3.05 g of 2,5-bis(4-chlorophenyl-1-)thiophene, 4.22 g of 9H-carbazole-3-boric acid, 6.36 g of sodium carbonate, 0.28 g of bis(triphenylphosphine)palladium dichloride, 240 mL of ethylene glycol dimethyl ether, and 80 mL of water were added to a reactor and stirred under reflux for 12 h. After cooling to room temperature, the mixture was filtered, and the filter cake was washed with 50 mL of ethylene glycol dimethyl ether, followed by three washings with 200 mL of water with stirring. The mixture was then filtered again, and the filter cake was dried under vacuum to obtain 5.02 g of 2,5-bis[4-(9H-carbazole-3-)phenyl-1-]thiophene.

[0197] Under a nitrogen atmosphere, 2.83 g of 2,5-bis[4-(9H-carbazole-3-)phenyl-1-]thiophene, 1.98 g of 2-bromobenzoxazole, 2.11 g of sodium tert-butoxide, 0.11 g of bis(dibenzylacetone)palladium, 0.19 g of 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl, and 200 ml of xylene were added to a reactor, and the mixture was stirred and refluxed for 24 h. After cooling to room temperature, the mixture was filtered, and the filter cake was washed with 200 ml of xylene, then washed twice with 200 ml of methanol. After filtration, the filter cake was washed with 50 ml of methanol, and the resulting filter cake was dried under vacuum to obtain 3.57 g of compound

[400] . 1 HNMR(DMSO):7.02(d,2H),7.0-7.8(m,30H).

[0198] Synthesis Example 15

[0199] Synthesis of compound

[401]

[0200] Except for the substitution of quinoline-4-boronic acid pinacol ester with 9-phenanthroline, the rest of the synthetic steps were the same as those for compound

[286] . 6.58 g of compound

[401] was obtained.

[0201] 1HNMR(DMSO):7.03(d,2H),7.3-7.6(m,16H),7.8-7.9(m,10H),8.15(m,4H),8.98(m,4H).

[0202] Synthesis example 16

[0203] Synthesis of compound

[402]

[0204] Except for replacing 2,5-bis(4-chlorophenyl-1-)thiophene with 2,5-dibromothiophene and 2-bromobenzoxazole with 4-bromobiphenyl, the rest of the synthetic steps were the same as those for compound

[400] . 3.06 g of compound

[402] was obtained.

[0205] 1 HNMR(DMSO):7.03(d,2H),7.2-7.6(m,30H),7.81(d,2H).

[0206] Synthesis Example 17

[0207] Synthesis of compound

[403]

[0208] Except for replacing 2,5-bis(4-chlorophenyl-1-)thiophene with 2,5-dibromothiophene, replacing 9H-carbazole-3-boronic acid with 6-phenyl-9H-carbazole-3-boronic acid, and replacing 2-bromobenzoxazole with bromobenzene, the rest of the synthetic steps were the same as those for compound

[400] . 2.91 g of compound

[402] was obtained.

[0209] 1 HNMR(DMSO):7.05(d,2H),7.2-7.5(m,28H),7.80(d,4H).

[0210] Synthesis Example 18

[0211] Synthesis of compound

[404]

[0212] Except for the substitution of quinoline-4-boronic acid pinacol ester with 1-pyreneboronic acid, the rest of the synthetic steps were the same as those for compound

[286] . 6.88 g of compound

[404] was obtained.

[0213] 1 HNMR(DMSO):7.05(d,2H),7.2-7.6(m,16H),7.7-8.1(m,18H).

[0214] Synthesis example 19

[0215] Synthesis of compound

[405]

[0216] Except for the substitution of benzotriazole with 9H-carbazole, the rest of the synthetic steps were the same as those for compound

[220] . 6.78 g of compound

[405] was obtained.

[0217] 1 HNMR(DMSO):7.01(d,2H),7.1-7.2(m,8H)7.2-7.6(m,24H).

[0218] Synthesis example 20

[0219] Synthesis of compound

[406]

[0220] Except for the substitution of quinoline-4-boronic acid for pinacol ester, the rest of the synthetic steps were the same as those for compound

[286] . 4.66 g of compound

[406] was obtained.

[0221] 1 HNMR(DMSO):7.02(d,2H),7.4-7.6(m,16H),8.0-8.1(d,6H).

[0222] Synthesis Example 21

[0223] Synthesis of compound

[407]

[0224] Except for the substitution of quinoline-4-boronic acid for pinacol ester, the rest of the synthetic steps were the same as those for compound

[286] . 4.77 g of compound

[407] was obtained.

[0225] 1 HNMR(DMSO):7.02(d,2H),7.4-7.6(m,20H),8.71(d,4H).

[0226] Synthesis example 22

[0227] Synthesis of compound

[408]

[0228] Except for the substitution of 2-bromobenzoxazole with bromobenzene, the rest of the synthetic steps were the same as those for compound

[400] . 3.18 g of compound

[408] was obtained.

[0229] 1 HNMR(DMSO):7.03(d,2H),7.2-7.7(m,32H).

[0230] Synthesis example 23

[0231] Synthesis of compound

[409]

[0232] Except for the substitution of quinoline-4-boronic acid for pinacol ester, the rest of the synthetic steps were the same as those for compound

[286] . 6.23 g of compound

[409] was obtained.

[0233] 1HNMR(DMSO):7.04(d,2H),7.3-7.6(m,16H),7.8-7.9(m,8H),8.1-8.3(m,6H),8.98(m,4H).

[0234] In the preparation example and the comparative example, the following substances were used:

[0235] TBDB: N,N,N',N'-Tetra(4-biphenyl)diaminobiphenyl (structure shown below)

[0236]

[0237] NPD: N,N'-Diphenyl-N,N'-Di(1-naphthyl)-1,1'-biphenyl-4,4'-diamine (structure shown below)

[0238]

[0239] F4-TCNQ: 2,3,5,6-Tetrafluoro-7,7',8,8'-Tetracyanodimethyl-p-benzoquinone (structure shown below)

[0240]

[0241] BH: 9-(2-naphthyl)-10-(4-(1-naphthyl)phenyl)anthracene (structure shown below)

[0242]

[0243] BD: E-7-(4-(diphenylamino)styryl)-N,N-diphenyl-9,9'-dimethylfluorenyl-2-amine (structure shown below)

[0244]

[0245] Alq3: Tris(8-hydroxyquinoline)aluminum (structure shown below)

[0246]

[0247] SPA1: (Structure as follows)

[0248]

[0249] SPA2: (Structure as follows)

[0250]

[0251] Preparation Example 1

[0252] Methods for preparing thin film samples

[0253] An alkali-free glass substrate (Asahi Glass Co., Ltd., AN100) undergoes a 20-minute UV ozone cleaning treatment, and is then placed in a vacuum evaporation apparatus for degassing until the vacuum level inside the apparatus reaches 1×10⁻⁶. -3 Under high vacuum conditions, a thin film of about 50 nm was prepared by resistive heating evaporation of compound [1]. The evaporation rate was 0.1 nm / s.

[0254] The refractive index and attenuation coefficient of the thin film samples prepared above were measured at Toray Research Center, Inc., using an elliptic polarization spectrometer (JAWoollam M-2000).

[0255] Table 1

[0256]

[0257] Preparation Examples 2-23 and Comparative Examples 1, 2, 3, and 4

[0258] Preparation Example 2

[0259] Except for changing compound

[001] to compound

[004] , the preparation was the same as in Preparation Example 1.

[0260] The obtained thin film samples were evaluated. The evaluation results are shown in Table 2.

[0261] Preparation Example 3

[0262] Except for changing compound

[001] to compound

[022] , the preparation method is the same as in Preparation Example 1.

[0263] The obtained thin film samples were evaluated. The evaluation results are shown in Table 2.

[0264] Preparation Example 4

[0265] Except for changing compound

[001] to compound

[067] , the preparation method is the same as in Preparation Example 1.

[0266] The obtained thin film samples were evaluated. The evaluation results are shown in Table 2.

[0267] Preparation Example 5

[0268] Except for changing compound

[001] to compound

[162] , the preparation was the same as in Preparation Example 1.

[0269] The obtained thin film samples were evaluated. The evaluation results are shown in Table 2.

[0270] Preparation Example 6

[0271] Except for changing compound

[001] to compound

[151] , the preparation was the same as in Preparation Example 1.

[0272] The obtained thin film samples were evaluated. The evaluation results are shown in Table 2.

[0273] Preparation Example 7

[0274] Except for changing compound

[001] to compound

[220] , the preparation was the same as in Preparation Example 1.

[0275] The obtained thin film samples were evaluated. The evaluation results are shown in Table 2.

[0276] Preparation Example 8

[0277] Except for changing compound

[001] to compound

[250] , the preparation method is the same as in Preparation Example 1.

[0278] The obtained thin film samples were evaluated. The evaluation results are shown in Table 2.

[0279] Preparation Example 9

[0280] Except for changing compound

[001] to compound

[286] , the preparation method is the same as in Preparation Example 1.

[0281] The obtained thin film samples were evaluated. The evaluation results are shown in Table 2.

[0282] Preparation Example 10

[0283] Except for changing compound

[001] to compound

[302] , the preparation method is the same as in Preparation Example 1.

[0284] The obtained thin film samples were evaluated. The evaluation results are shown in Table 2.

[0285] Preparation Example 11

[0286] Except for changing compound

[001] to compound

[359] , the preparation method is the same as in Preparation Example 1.

[0287] Preparation Example 12

[0288] Except for changing compound

[359] to compound

[398] , the preparation was the same as in Preparation Example 11.

[0289] Preparation Example 13

[0290] Except for changing compound

[359] to compound

[399] , the preparation was the same as in Preparation Example 11.

[0291] Preparation Example 14

[0292] Except for changing compound

[359] to compound

[400] , the preparation was the same as in Preparation Example 11.

[0293] Preparation Example 15

[0294] Except for changing compound

[359] to compound

[401] , the preparation was the same as in Preparation Example 11.

[0295] Preparation Example 16

[0296] Except for changing compound

[359] to compound

[402] , the preparation was the same as in Preparation Example 11.

[0297] Preparation Example 17

[0298] Except for changing compound

[359] to compound

[403] , the preparation was the same as in Preparation Example 11.

[0299] Preparation Example 18

[0300] Except for changing compound

[359] to compound

[404] , the preparation was the same as in Preparation Example 11.

[0301] Preparation Example 19

[0302] Except for changing compound

[359] to compound

[405] , the preparation was the same as in Preparation Example 11.

[0303] Preparation Example 20

[0304] Except for changing compound

[359] to compound

[406] , the preparation was the same as in Preparation Example 11.

[0305] Preparation Example 21

[0306] Except for changing compound

[359] to compound

[407] , the preparation was the same as in Preparation Example 11.

[0307] Preparation Example 22

[0308] Except for changing compound

[359] to compound

[408] , the preparation was the same as in Preparation Example 11.

[0309] Preparation Example 23

[0310] Except for changing compound

[359] to compound

[409] , the preparation was the same as in Preparation Example 11.

[0311] The obtained thin film samples were evaluated. The evaluation results are shown in Table 2.

[0312] Comparative Example 1

[0313] Except for changing compound [1] to NPD, the preparation was the same as in Preparation Example 1.

[0314] Comparative Example 2

[0315] Except for changing compound [1] to SPA1, the preparation was the same as in Preparation Example 1.

[0316] Comparative Example 3

[0317] Except for changing compound [1] to TBDB, the preparation was the same as in Preparation Example 1.

[0318] Comparative Example 4

[0319] Except for changing compound [1] to SPA2, the preparation was the same as in Preparation Example 1.

[0320] The obtained thin film samples were evaluated. The evaluation results are shown in Table 2.

[0321] Table 2

[0322]

[0323]

[0324] As shown in Table 2 above, the refractive indices of Preparation Examples 1 to 23 were all significantly higher than those of Comparative Examples 1, 2, 3, and 4. Furthermore, the performance of the light-emitting elements was tested.

[0325] Evaluation methods for light-emitting elements

[0326] Preparation Example 24

[0327] After being ultrasonically cleaned in isopropanol for 15 minutes, the alkali-free glass underwent a UV ozone cleaning treatment in the atmosphere for 30 minutes. Using a vacuum evaporation method, aluminum was first deposited at a depth of 100 nm to form the anode. Subsequently, a hole injection layer (NPD and F4-TCNQ (weight ratio 97:3), 50 nm), a hole transport layer (NPD, 80 nm), a blue emitting layer (BH and BD (weight ratio 97:3, 20 nm), an electron transport layer (Alq3, 30 nm), and an electron injection layer (LiF, 1 nm) were sequentially stacked and deposited on the anode. Finally, Mg and Ag (weight ratio 10:1, 15 nm) were co-deposited to form a semi-transparent cathode.

[0328] Subsequently, compound

[001] (60 nm) was vapor-deposited as a cover layer.

[0329] Finally, in a glove box with a dry nitrogen atmosphere, the light-emitting element is sealed with an alkali-free glass sealing plate using epoxy resin adhesive.

[0330] The above-mentioned light-emitting element, at room temperature and in atmospheric conditions, with an applied current of 10 mA / cm² 2The luminance and color purity of the light-emitting element were measured using a direct current spectroradiometer (CS1000, Konica Minolta, Inc.) from the sealing plate. The luminous efficiency was determined to be 7.5 cd / A, and the color purity was CIE(x, y) = (0.138, 0.050). A high-performance light-emitting element with high luminous efficiency and high color purity was obtained by using compound

[001] as a capping layer.

[0331] The organic light-emitting elements were evaluated. The evaluation results are shown in Table 3.

[0332] Preparation Example 25

[0333] Except for the fact that the coating material is a compound

[004] , the rest is the same as in Preparation Example 24.

[0334] The organic light-emitting elements were evaluated. The evaluation results are shown in Table 3.

[0335] Preparation Example 26

[0336] Except for the fact that the coating material is a compound

[022] , the rest is the same as in Preparation Example 24.

[0337] The organic light-emitting elements were evaluated. The evaluation results are shown in Table 3.

[0338] Preparation Example 27

[0339] Except for the fact that the coating material is a compound

[067] , the rest is the same as in Preparation Example 24.

[0340] The organic light-emitting elements were evaluated. The evaluation results are shown in Table 3.

[0341] Preparation Example 28

[0342] Except that the coating material is a compound

[162] , it is the same as in Preparation Example 24.

[0343] The organic light-emitting elements were evaluated. The evaluation results are shown in Table 3.

[0344] Preparation Example 29

[0345] Except that the coating material is a compound

[151] , it is the same as in Preparation Example 24.

[0346] The organic light-emitting elements were evaluated. The evaluation results are shown in Table 3.

[0347] Preparation Example 30

[0348] Except that the coating material is compound

[220] , it is the same as in preparation example 24.

[0349] The organic light-emitting elements were evaluated. The evaluation results are shown in Table 3.

[0350] Preparation Example 31

[0351] Except that the coating material is compound

[250] , it is the same as in preparation example 24.

[0352] The organic light-emitting elements were evaluated. The evaluation results are shown in Table 3.

[0353] Preparation Example 32

[0354] Except that the coating material is a compound

[286] , it is the same as in Preparation Example 24.

[0355] The organic light-emitting elements were evaluated. The evaluation results are shown in Table 3.

[0356] Preparation Example 33

[0357] Except for the fact that the coating material is compound

[302] , it is the same as in preparation example 24.

[0358] The organic light-emitting elements were evaluated. The evaluation results are shown in Table 3.

[0359] Preparation Example 34

[0360] Except that the coating material is a compound

[359] , it is the same as in Preparation Example 24.

[0361] The organic light-emitting elements were evaluated. The evaluation results are shown in Table 3.

[0362] Preparation Example 35

[0363] Except that the coating material is a compound

[398] , it is the same as in Preparation Example 24.

[0364] The organic light-emitting elements were evaluated. The evaluation results are shown in Table 3.

[0365] Preparation Example 36

[0366] Except that the coating material is a compound

[399] , it is the same as in Preparation Example 24.

[0367] The organic light-emitting elements were evaluated. The evaluation results are shown in Table 3.

[0368] Preparation Example 37

[0369] Except for the fact that the coating material is compound

[400] , it is the same as in preparation example 24.

[0370] The organic light-emitting elements were evaluated. The evaluation results are shown in Table 3.

[0371] Preparation Example 38

[0372] Except for the fact that the coating material is compound

[401] , it is the same as in preparation example 24.

[0373] The organic light-emitting elements were evaluated. The evaluation results are shown in Table 3.

[0374] Preparation Example 39

[0375] Except for the fact that the coating material is compound

[402] , it is the same as in preparation example 24.

[0376] The organic light-emitting elements were evaluated. The evaluation results are shown in Table 3.

[0377] Preparation Example 40

[0378] Except for the fact that the coating material is compound

[403] , it is the same as in preparation example 24.

[0379] The organic light-emitting elements were evaluated. The evaluation results are shown in Table 3.

[0380] Preparation Example 41

[0381] Except for the fact that the coating material is compound

[404] , the preparation method is the same as in Preparation Example 4.

[0382] The organic light-emitting elements were evaluated. The evaluation results are shown in Table 3.

[0383] Preparation Example 42

[0384] Except for the fact that the coating material is compound

[405] , it is the same as in preparation example 24.

[0385] The organic light-emitting elements were evaluated. The evaluation results are shown in Table 3.

[0386] Preparation Example 43

[0387] Except for the fact that the coating material is compound

[406] , it is the same as in preparation example 24.

[0388] The organic light-emitting elements were evaluated. The evaluation results are shown in Table 3.

[0389] Preparation Example 44

[0390] Except for the fact that the coating material is compound

[407] , it is the same as in preparation example 24.

[0391] The organic light-emitting elements were evaluated. The evaluation results are shown in Table 3.

[0392] Preparation Example 45

[0393] Except for the fact that the coating material is compound

[408] , it is the same as in preparation example 24.

[0394] The organic light-emitting elements were evaluated. The evaluation results are shown in Table 3.

[0395] Preparation Example 46

[0396] Except for the fact that the coating material is compound

[409] , it is the same as in preparation example 24.

[0397] The organic light-emitting elements were evaluated. The evaluation results are shown in Table 3.

[0398] Comparative Example 5

[0399] Except for the fact that the capping material is NPD, the preparation method is the same as in Preparation Example 24.

[0400] The organic light-emitting elements were evaluated. The evaluation results are shown in Table 3.

[0401] Comparative Example 6

[0402] Except for the fact that the capping material is SPA1, the preparation method is the same as in Preparation Example 24.

[0403] Comparative Example 7

[0404] Except for the fact that the capping material is TBDB, the preparation method is the same as in Preparation Example 24.

[0405] Comparative Example 8

[0406] Except for the fact that the capping material is SPA2, the rest is the same as in preparation example 24.

[0407] The organic light-emitting elements were evaluated. The evaluation results are shown in Table 3.

[0408] Table 3

[0409]

[0410]

[0411] As shown in Table 3 above, the light-emitting elements of Preparation Examples 24 to 46 simultaneously satisfy both high luminous efficiency and high color purity. On the other hand, the light-emitting elements of Comparative Examples 5 to 8 have the same level of color purity as the preparation examples, but their luminous efficiency is lower than that of the preparation examples. The light-emitting elements in each preparation example show a significant improvement in luminous efficiency compared to Comparative Examples 5, 6, 7, and 8.

[0412] The above results show that the compounds of the present invention are suitable for organic light-emitting element materials, and can obtain light-emitting elements that simultaneously meet the requirements of high luminous efficiency and high color purity, and can obtain more excellent capping layer materials.

Claims

1. A light-emitting element, characterized in that: The device comprises a substrate, a first electrode, one or more film layers including a light-emitting layer, a second electrode, and a capping layer; the capping layer contains an organic compound having the following structure: 。

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