Organic compound for organic light-emitting device, organic electroluminescent device

Abstract

The present invention provides a compound and its application. The compound has a structure shown in formula (1). When the compound of the present invention is used in an organic electroluminescent device, especially as a luminescent dye material, the device excitation voltage can be effectively reduced, the device luminescence efficiency can be improved, and the best effect can be achieved.

Description

Technical Field

[0001] The invention relates to the technical field of organic electroluminescence, in particular to an organic compound and application thereof, and also to an organic electroluminescence device. Background Art

[0002] In recent years, optoelectronic devices based on organic materials have become increasingly popular. The inherent flexibility of organic materials makes them very suitable for manufacturing on flexible substrates. Beautiful and cool optoelectronic products can be designed and produced according to demand, gaining unparalleled advantages over inorganic materials. Examples of such organic optoelectronic devices include organic light-emitting diodes (OLEDs), organic field-effect transistors, organic photovoltaic cells, organic sensors, etc. Among them, OLED has developed particularly rapidly and has achieved commercial success in the field of information display. OLED can provide highly saturated red, green, and blue colors. Full-color display devices made of OLEDs do not require additional backlight sources and have the advantages of brilliant colors, lightness, thinness, and softness.

[0003] The core of OLED devices is a thin film structure containing a variety of organic functional materials. Common functionalized organic materials include: hole injection materials, hole transport materials, hole blocking materials, electron injection materials, electron transport materials, electron blocking materials, luminescent host materials and luminescent guest (dyes), etc. When power is turned on, electrons and holes are injected and transported to the luminescent area respectively and recombine there, thereby generating excitons and emitting light.

[0004] People have developed a variety of organic materials, combined with various unique device structures, which can improve carrier mobility, regulate carrier balance, break through electroluminescence efficiency, and delay device attenuation. For quantum mechanical reasons, common fluorescent luminescent bodies mainly use singlet excitons generated when electrons and vacancies combine to emit light, and are still widely used in various OLED products. Some metal complexes, such as iridium complexes, can simultaneously use triplet excitons and singlet excitons to emit light, and are called phosphorescent luminescent bodies. Their energy conversion efficiency can be increased by up to four times that of traditional fluorescent luminescent bodies. Thermally excited delayed fluorescence (TADF) technology promotes the transformation of triplet excitons to singlet excitons. Without the use of metal complexes, triplet excitons can still be effectively utilized to achieve higher luminescence efficiency. Thermally excited sensitized fluorescence (TASF) technology uses materials with TADF properties to sensitize luminescent bodies by energy transfer, which can also achieve higher luminescence efficiency. Especially in the field of blue luminescence, which has always been difficult to effectively improve luminescence efficiency, it has a very broad application prospect.

[0005] In the field of OLED blue light emission, the following luminescent dye capable of thermal excitation sensitization has been developed (CN110759851A), which utilizes triplet excitons to achieve higher luminescence efficiency.

[0006]

[0007] However, as OLED products gradually enter the market, people have increasingly higher requirements for the performance of such products. The above-mentioned OLED materials and device structures cannot completely solve the problems of OLED product efficiency, life span, cost, etc., and there is room for further improvement. Summary of the invention

[0008] Through in-depth research, the researchers of the present invention have discovered an ingenious molecular design scheme, which has obtained a luminescent dye material with better product efficiency. The compound disclosed by the present invention is very suitable for application in OLED and improving the performance of the device, and is particularly suitable for use as a blue light dye material.

[0009] Specifically, the present invention provides an organic compound characterized by having a structure shown in formula (1);

[0010]

[0011] in:

[0012] D 1 , D 2 are independently selected from the group represented by formula (2):

[0013]

[0014] X 1 ~X 8 Independently selected from N or CR 1 , R 1 is independently selected from one of hydrogen, substituted or unsubstituted C1-C20 alkyl, substituted or unsubstituted C1-C20 alkoxy, halogen, cyano, nitro, hydroxyl, amino, substituted or unsubstituted C1-C20 silyl, substituted or unsubstituted C6-C60 arylamino, substituted or unsubstituted C3-C60 heteroarylamino, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C3-C60 heteroaryl,

[0015] D 3 , D 4 Independently selected from the group represented by formula (3):

[0016]

[0017] Y 1 ~Y 8 are independently selected from CH or N;

[0018] R is selected from one of hydrogen, halogen, cyano, nitro, hydroxyl, amino, substituted or unsubstituted C1-C20 chain alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C1-C20 silyl, substituted or unsubstituted C6-C60 arylamino, substituted or unsubstituted C3-C60 heteroarylamino, substituted or unsubstituted C6-C60 aryl, and substituted or unsubstituted C3-C60 heteroaryl;

[0019] The groups in the above-mentioned "substituted or unsubstituted" are substituted by one or more groups selected from halogen, cyano, C1-C17 amino, C1-C17 carboxyl, C1-C17 aldehyde, C1-C17 ester, C1-C12 chain alkyl, C3-C12 cycloalkyl, C2-C10 alkenyl, C1-C10 alkoxy or thioalkoxy, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryl, and C3-C30 heteroaryl.

[0020] It should be noted that in this specification, the expression of Ca to Cb means that the number of carbon atoms in the group is a to b. Unless otherwise specified, the number of carbon atoms does not include the number of carbon atoms in the substituent. In the present invention, the expression of chemical elements, unless otherwise specified, usually includes the concept of isotopes with the same chemical properties. For example, the expression of "hydrogen" also includes the concept of "deuterium" and "tritium" with the same chemical properties. Carbon (C) includes 12 C. 13 C, etc., no further details.

[0021] In the structural formula disclosed in this specification, the expression of a ring structure crossed by “—” indicates that the connection site is any position on the ring structure that can form a bond.

[0022] In this specification, unless otherwise specified, aryl and heteroaryl include both monocyclic and condensed rings. The so-called monocyclic aryl refers to a molecule containing at least one phenyl group. When the molecule contains at least two phenyl groups, the phenyl groups are independent of each other and connected by a single bond, such as phenyl, biphenyl, terphenyl, etc.; condensed ring aryl refers to a molecule containing at least two benzene rings, but the benzene rings are not independent of each other, but condensed to each other by sharing the ring edge, such as naphthyl, anthracenyl, etc.; monocyclic heteroaryl refers to a molecule containing at least one heteroaryl group. When the molecule contains one heteroaryl group and other groups (such as aryl, heteroaryl, alkyl, etc.), the heteroaryl group and other groups are independent of each other and connected by a single bond, such as pyridine, furan, thiophene, etc.; condensed ring heteroaryl refers to a molecule composed of at least one phenyl group and at least one heteroaryl group fused together, or at least two heteroaryl rings fused together, such as quinoline, isoquinoline, benzofuran, dibenzofuran, benzothiophene, dibenzothiophene, etc.

[0023] In this specification, substituted or unsubstituted C6 to C 30 The aryl group is preferably C6-C 20 The aryl group is more preferably a group selected from the group consisting of phenyl, naphthyl, anthracenyl, benzanthryl, phenanthryl, triphenylenyl, pyrenyl, chrysene, peryl, fluoranthenyl, tetraphenyl, pentacene, benzopyrenyl, biphenyl, phenylene, terphenyl, triphenylene, quaterphenyl, fluorenyl, spirobifluorenyl, dihydrophenanthryl, dihydropyrenyl, tetrahydropyrenyl, cis- or trans-indenofluorenyl, trimerized indenyl, isotrimerized indenyl, spirotrimerized indenyl, and spiroisotrimerized indenyl. Specifically, the biphenyl group is selected from 2-biphenyl, 3-biphenyl and 4-biphenyl; the terphenyl group includes p-terphenyl-4-yl, p-terphenyl-3-yl, p-terphenyl-2-yl, m-terphenyl-4-yl, m-terphenyl-3-yl and m-terphenyl-2-yl; the naphthyl group includes 1-naphthyl or 2-naphthyl; the anthracenyl group is selected from 1-anthracenyl, 2-anthracenyl and 9-anthracenyl; the fluorenyl group is selected from 1-fluorenyl, 2-fluorenyl, 3-fluorenyl, 4-fluorenyl and 9-fluorenyl; the pyrenyl group is selected from 1-pyrenyl, 2-pyrenyl and 4-pyrenyl; the tetraphenyl group is selected from 1-tetraphenyl, 2-tetraphenyl and 9-tetraphenyl. Preferred examples of the aryl group in the present invention include phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, phenanthrenyl, indenyl, fluorenyl and its derivatives, fluoranthenyl, triphenylene, pyrenyl, peryl, The biphenyl group is selected from the group consisting of 2-biphenyl, 3-biphenyl and 4-biphenyl; the terphenyl group includes p-terphenyl-4-yl, p-terphenyl-3-yl, p-terphenyl-2-yl, m-terphenyl-4-yl, m-terphenyl-3-yl and m-terphenyl-2-yl; the naphthyl group includes 1-naphthyl or 2-naphthyl; the anthracenyl group is selected from the group consisting of 1-anthracenyl, 2-anthracenyl and The fluorenyl group is selected from the group consisting of 1-fluorenyl, 2-fluorenyl, 3-fluorenyl, 4-fluorenyl and 9-fluorenyl; the fluorenyl derivative is selected from the group consisting of 9,9-dimethylfluorene, 9,9-spirobifluorene and benzofluorene; the pyrenyl group is selected from the group consisting of 1-pyrenyl, 2-pyrenyl and 4-pyrenyl; the naphthyl group is selected from the group consisting of 1-naphthyl, 2-naphthyl and 9-naphthyl.

[0024] The heteroatom in the present invention is generally selected from N, O, S, P, Si and Se, preferably selected from N, O and S.

[0025] In the present specification, the substituted or unsubstituted C3-C30 heteroaryl group is preferably a C4-C20 heteroaryl group, and more preferably a nitrogen-containing heteroaryl group, an oxygen-containing heteroaryl group, a sulfur-containing heteroaryl group, and the like. Specific examples include: furyl, thienyl, pyrrolyl, pyridyl, benzofuranyl, benzothienyl, isobenzofuranyl, isobenzothienyl, indolyl, isoindolyl, dibenzofuranyl, dibenzothienyl, carbazolyl and its derivatives, quinolyl, isoquinolyl, acridinyl, phenanthridinyl, benzo-5-, 6-quinolyl, benzo-6,7-quinolyl, benzo-7,8-quinolyl, phenothiazinyl, phenazinyl, pyrazolyl, indazolyl, imidazolyl, benzimidazolyl, naphthoimidazolyl, phenanthroimidazolyl, pyridoimidazolyl, pyrazinoimidazolyl, quinoxalin imidazolyl, oxazolyl, benzoxazolyl, naphthoxazolyl, anthrazolyl, phenanthroxazolyl, 1,2-thiazolyl, 1,3-thiazolyl, benzothiazolyl, pyridazinyl, benzopyridazinyl, pyrimidinyl, benzopyrimidinyl, quinoxalinyl, 1,5-diazaanthryl, 2,7-diazapyrenyl, 2,3-diazapyrenyl, 1,6-diazapyrenyl, 1,8-diazapyrenyl, 4, 5-diazapyrenyl, 4,5,9,10-tetraazaperyl, pyrazinyl, phenazinyl, phenothiazinyl, naphthyridinyl, azacarbazolyl, benzocarbolinyl, phenanthrolinyl, 1,2,3-triazolyl, 1,2,4-triazolyl, benzotriazolyl, 1,2,3-oxadiazolyl, 1,2,4-oxadiazolyl, 1,2,5-oxadiazolyl, 1,2,3-thiadiazolyl, 1,2,4-thiadiazolyl, 1,2,5-thiadiazolyl, 1,3,4-thiadiazolyl, 1,3,5-triazinyl, 1,2,4-triazinyl, 1,2,3-triazinyl, tetrazolyl, 1,2,4,5-tetrazinyl, 1,2,3,4-tetrazinyl, 1,2,3,5-tetrazinyl, purinyl, pteridinyl, indolizinyl, benzothiadiazole, etc. Preferred examples of heteroaryl in the present invention include furanyl, thienyl, pyrrolyl, benzofuranyl, benzothienyl, isobenzofuranyl, indolyl, dibenzofuranyl, dibenzothienyl, carbazolyl and derivatives thereof, wherein the carbazolyl derivative is preferably 9-phenylcarbazole, 9-naphthylcarbazole, benzocarbazole, dibenzocarbazole or indolocarbazole.

[0026] In the present specification, examples of the C1-C30 alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, 2-methylbutyl, n-pentyl, sec-pentyl, cyclopentyl, n-hexyl, cyclohexyl, adamantyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl, pentafluoroethyl, and 2,2,2-trifluoroethyl.

[0027] In the present specification, the cycloalkyl group includes a monocyclic alkyl group and a polycyclic alkyl group, and examples thereof include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and the like.

[0028] In the present specification, examples of C1-C30 alkoxy groups include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, isobutoxy, pentyloxy, isopentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy, etc., among which methoxy, ethoxy, n-propoxy, isopropoxy, tert-butoxy, sec-butoxy, isobutoxy, isopentyloxy, and methoxy is more preferred.

[0029] In the present specification, examples of C1-C30 silyl groups include silyl groups substituted with the groups listed in the above C1-C30 alkyl groups, specifically including methylsilyl, dimethylsilyl, trimethylsilyl, ethylsilyl, diethylsilyl, triethylsilyl, tert-butyldimethylsilyl, tert-butyldiphenylsilyl and the like.

[0030] In the present specification, examples of halogen include fluorine, chlorine, bromine, and iodine.

[0031] In the present invention, the "substituted or unsubstituted" group may be substituted with one substituent or with multiple substituents. When there are multiple substituents, they may be selected from different substituents. When the same expressions are involved in the present invention, they all have the same meaning, and the selection range of substituents is as shown above and will not be repeated one by one.

[0032] In the present invention, it is very important that the above D 3 , D 4 Independently selected from the group represented by formula (3), that is, D 3 , D 4 It is unsubstituted carbazole or unsubstituted N-hybridized carbazole. The inventors found that if such a group is selected, the luminescence efficiency can be improved and the excitation voltage can be reduced accordingly. The specific reason why these compounds can further achieve excellent technical effects is still unclear. The following is the inventor's speculation: when the cyano meta-position adopts a carbazole structure without peripheral substituents, the conformation of the molecule is more conducive to accumulation into a state with high carrier transport performance during film formation, thereby improving the corresponding transport efficiency and also reducing the voltage. If D 3 , D 4 If there are substituents on the film, the film formation may be unfavorable for charge transport due to steric hindrance. The above reasons are only speculations, but these speculations do not limit the protection scope of the present invention.

[0033] From the viewpoint of ease of synthesis and better photoelectric performance, D 3 With D 4 are the same group.

[0034] D is very important in the present invention. 3 , D4 In terms of the above, preferably all of them are carbazole groups, but the carbazole groups can be replaced by 1 to 2 N hybridization groups, that is, wherein Y 1 ~Y 8 All are CH, or 1 or 2 of them are N and the rest are CH. More preferably, Y 1 ~Y 4 One or two of them are N and the rest are CH, among which Y 5 ~Y 8 One or two of them are N and the rest are CH. If the number of N hybrids is too large, it may cause D 3 , D 4 The electron-withdrawing ability of benzonitrile is too strong, which is not conducive to the improvement of the electron cloud density of the benzonitrile parent core and destroys the carrier transport property.

[0035] Overall, D 3 , D 4 Preferably selected from the following groups:

[0036]

[0037] More preferred are the following groups:

[0038]

[0039] D is very important in the present invention. 1 , D 2 In terms of X in formula (2), 1 ~X 8 Independently selected from N, CH, CR 1’ or CR 2 , as one of the R 1’ , preferably a group that can slightly increase the electron cloud on the carbazole group and provide appropriate steric hindrance.

[0040] Such groups as the above-mentioned substituted or unsubstituted C4-C20 alkyl, substituted or unsubstituted C1-C20 alkoxy, amino and substituted amino, substituted or unsubstituted C1-C20 silyl are good. Among them, substituted or unsubstituted C1-C20 saturated alkyl is particularly preferred. In this way, the carbazole structure substituted with a saturated alkyl at the ortho position of the cyano group and the electron donating ability of the carbazole peripheral substituent is in a suitable weak state, which is conducive to the blue shift of luminescence, making the light color of the compound of the present invention more outstanding.

[0041] Among them, R 2 is a group represented by the following formula (4),

[0042]

[0043] Where R a , Rb , R c Each independently selected from hydrogen, C1-C9 alkyl, R a , R b , R c Connected to form a ring or not connected to form a ring, R a , R b , R c At least one of them is hydrogen, and * represents the connection end with formula (2). Through such a preferred range, the peripheral substituents have relatively small steric hindrance and are in a suitable state, which is conducive to forming a suitable stacking structure during film formation, thereby improving the carrier transport performance and reducing the voltage. At the same time, it can provide protection for the active sites on carbazole, inhibit Dexter energy transfer, and improve stability. As a further preferred R 2 Examples of R include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, 2-methylbutyl, n-pentyl, sec-pentyl, cyclopentyl, neopentyl, n-hexyl, cyclohexyl, neohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl, pentafluoroethyl, 2,2, 2-trifluoroethyl, and more preferably methyl, ethyl, propyl, isopropyl, isobutyl, cyclopentyl, and cyclohexyl. When R 2 For these groups, compared to R 2 In the case of a tertiary carbon substituent, the effect of the present invention is further enhanced.

[0044] X 1 ~X 4 At least one of them is CR 2 ;

[0045] Preferred X 1 ~X 4 1 or 2 of them are CR 2 ;

[0046] Preferred X 1 ~X 4 1 of them is CR 2 .

[0047] As a further preferred range, X 1 ~X 8 Each independently selected from CH or CR 2 , where X 1 ~X 4 One or two of them are CR 2 , X 5 ~X 8 All are CH, or 1-2 of them are CR 2 , further optimize X 1 ~X 4 1 of them is CR 2, X 5 ~X 8 All are CH, or one of them is CR 2 .

[0048] X 1 ~X 4 1 of them is CR 2 , X 5 ~X 8 1 of them is CR 2 Preferably, X 1 ~X 4 1 of them is CR 2 , X 5 ~X 8 1 of them is CR 2 , and the R 2 Select the same group.

[0049] As mentioned above, as D 1 , D 2 The group X of formula (2) 1 ~X 8 Among them, X is preferred 3 and / or X 6 CR 2 , and the other groups are CH. Such substitution positions are more conducive to ensuring the appropriate electron cloud density of the carbazole group, and the luminescence efficiency is more outstanding. At the same time, it is more conducive to forming a suitable stacking structure during film formation, thereby improving the carrier transport performance.

[0050] The inventors' research also found that when R 2 When the tertiary carbon-containing group is a tertiary butyl group, a tertiary amyl group, etc., the sublimation temperature of the entire compound will be very high, which is not conducive to film formation. In short, in the compound of the present invention, R 2 Preferably, it is not a substituent containing a tertiary carbon atom.

[0051] As D 1 , D 2 Preferred groups include the following groups.

[0052]

[0053] Furthermore, as D 1 , D 2 Preferred groups include the following groups.

[0054]

[0055] In the compound of the present invention, R is preferably a hydrogen atom.

[0056] Furthermore, D 3 With D4 are the same group;

[0057] Furthermore, Y 1 ~Y 8 All are CH, or one of them is N and the rest are CH.

[0058] Furthermore, Y 1 ~Y 4 All are CH, or Y 1 ~Y 4 One or two of them are N and the rest are CH.

[0059] Furthermore, Y 5 ~Y 8 All are CH, or Y 5 ~Y 8 One or two of them are N and the rest are CH.

[0060] Furthermore, the group represented by formula (3) is selected from the following groups,

[0061]

[0062] Furthermore, the organic compound of the present invention can preferably include the specific structural compounds shown below, which are only representative and do not limit the scope of the present invention.

[0063]

[0064]

[0065]

[0066]

[0067]

[0068]

[0069]

[0070]

[0071] In addition, the preparation process of the compound of the present invention is simple and easy, the raw materials are easily available, it is suitable for mass production and expansion, and is very suitable for industrial application.

[0072] The above-mentioned compound of the present invention has excellent luminescent properties, can provide triplet excitons to achieve higher luminescent efficiency, and is suitable for use as a luminescent dye, especially as a blue luminescent dye, based on its excellent carrier transfer efficiency. Of course, since the compound of the present invention can also be used as a sensitizer together with the host material and the dye to achieve a good luminescent layer. The devices used include but are not limited to organic electroluminescent devices, optical sensors, solar cells, lighting elements, organic thin film transistors, organic field effect transistors, organic thin film solar cells, information tags, electronic artificial skin sheets, sheet-type scanners or electronic paper, preferably organic electroluminescent devices.

[0073] The present invention also provides an organic electroluminescent device, which comprises a first electrode, a second electrode and at least one or more light-emitting functional layers inserted between the first electrode and the second electrode, wherein the light-emitting functional layer contains at least one compound described in the present invention.

[0074] The structure of the organic electroluminescent device of the present invention is consistent with that of the existing devices, for example, it includes an anode layer, multiple light-emitting functional layers and a cathode layer; the multiple light-emitting functional layers at least include a light-emitting layer, wherein the light-emitting layer contains the above-mentioned organic compound of the present invention.

[0075] The OLED device prepared by using the compound of the present invention has low starting voltage, high luminous efficiency and better service life, and can meet the requirements of current panel and display manufacturers for high-performance materials. DETAILED DESCRIPTION

[0076] The technical solution of the present invention is further described in more detail below. It should be understood by those skilled in the art that the embodiments are only used to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0077] Method for obtaining the compound of the present invention

[0078] The compound represented by the general formula (1) of the present invention can be obtained by a known method, for example, by a known organic synthesis method. An exemplary synthesis route is given below, but those skilled in the art can also obtain it by other known methods.

[0079] Synthesis process

[0080]

[0081] The structure of the organic electroluminescent device of the present invention is a known structure, and is characterized in that the compound of the present invention is used in the light-emitting layer. The organic electroluminescent device is described in detail below.

[0082] OLED includes a first electrode, a second electrode, and an organic material layer between the electrodes. The organic material can be divided into multiple regions. For example, the organic material layer can include a hole transport region, a light emitting layer, and an electron transport region.

[0083] In a specific embodiment, a substrate may be used below the first electrode or above the second electrode. The substrate is a glass or polymer material with excellent mechanical strength, thermal stability, water resistance, and transparency. In addition, a thin film transistor (TFT) may also be provided on the substrate used as a display.

[0084] The first electrode can be formed by sputtering or depositing the material used as the first electrode on the substrate. When the first electrode is used as an anode, an oxide transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (SnO2), zinc oxide (ZnO) and any combination thereof can be used. When the first electrode is used as a cathode, a metal or alloy such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), ytterbium (Yb), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag) and any combination thereof can be used.

[0085] The organic material layer can be formed on the electrode by vacuum thermal evaporation, spin coating, printing, etc. The compound used as the organic material layer can be organic small molecules, organic macromolecules and polymers, and combinations thereof.

[0086] The hole transport region is located between the anode and the light-emitting layer. The hole transport region can be a single-layer hole transport layer (HTL), including a single-layer hole transport layer containing only one compound and a single-layer hole transport layer containing multiple compounds. The hole transport region can also be a multilayer structure including at least one layer of a hole injection layer (HIL), a hole transport layer (HTL), and an electron blocking layer (EBL); wherein the HIL is located between the anode and the HTL, and the EBL is located between the HTL and the light-emitting layer.

[0087] The material of the hole transport region can be selected from, but not limited to, phthalocyanine derivatives such as CuPc, conductive polymers or polymers containing conductive dopants such as polyphenylene ethylene, polyaniline / dodecylbenzenesulfonic acid (Pani / DBSA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / camphorsulfonic acid (Pani / CSA), polyaniline / poly(4-styrenesulfonate) (Pani / PSS), aromatic amine derivatives such as the compounds shown in HT-1 to HT-51 below; or any combination thereof.

[0088]

[0089]

[0090]

[0091] The hole injection layer is located between the anode and the hole transport layer. The hole injection layer can be a single compound material or a combination of multiple compounds. For example, the hole injection layer can use one or more compounds of HT-1 to HT-50 mentioned above, or one or more compounds of HI-1 to HI-3 below; or one or more compounds of HT-1 to HT-51 can be doped with one or more compounds of HI-1 to HI-3 below.

[0092]

[0093] The light-emitting layer includes a light-emitting dye (i.e., dopant) that can emit light of different wavelength spectra, and may also include a host material (Host). The light-emitting layer may be a monochrome light-emitting layer that emits a single color such as red, green, and blue. A plurality of monochrome light-emitting layers of different colors may be arranged in a plane according to a pixel pattern, or may be stacked together to form a color light-emitting layer. When light-emitting layers of different colors are stacked together, they may be separated from each other or may be connected to each other. The light-emitting layer may also be a single color light-emitting layer that can simultaneously emit different colors such as red, green, and blue.

[0094] According to different technologies, the light-emitting layer material can be made of different materials such as fluorescent electroluminescent materials, phosphorescent electroluminescent materials, and thermally activated delayed fluorescent materials. In an OLED device, a single light-emitting technology can be used, or a combination of multiple different light-emitting technologies can be used. These different light-emitting materials classified by technology can emit light of the same color or different colors.

[0095] In one aspect of the present invention, the light-emitting layer adopts the technology of thermally activated delayed fluorescence luminescence, and the main material of the light-emitting layer is selected from, but not limited to, one or more combinations of PH-1 to PH-85.

[0096]

[0097]

[0098]

[0099]

[0100] In one aspect of the present invention, an electron blocking layer (EBL) is located between the hole transport layer and the light emitting layer. The electron blocking layer may be, but not limited to, one or more of the compounds HT-1 to HT-51 described above, or one or more of the compounds PH-47 to PH-77 described above; or a mixture of, but not limited to, one or more of the compounds HT-1 to HT-51 and one or more of the compounds PH-47 to PH-77.

[0101] The OLED organic material layer may further include an electron transport region between the light emitting layer and the cathode. The electron transport region may be a single-layer electron transport layer (ETL), including a single-layer electron transport layer containing only one compound and a single-layer electron transport layer containing multiple compounds. The electron transport region may also be a multi-layer structure including at least one layer of an electron injection layer (EIL), an electron transport layer (ETL), and a hole blocking layer (HBL).

[0102] In one aspect of the present invention, the electron transport layer material can be selected from, but not limited to, one or more combinations of ET-1 to ET-65 listed below.

[0103]

[0104]

[0105]

[0106]

[0107] In one aspect of the present invention, a hole blocking layer (HBL) is located between the electron transport layer and the light emitting layer. The hole blocking layer may be, but not limited to, one or more compounds of ET-1 to ET-65, or one or more compounds of PH-1 to PH-46; or a mixture of one or more compounds of ET-1 to ET-65 and one or more compounds of PH-1 to PH-46.

[0108] The device may further include an electron injection layer located between the electron transport layer and the cathode. Materials for the electron injection layer include, but are not limited to, one or more combinations of the following.

[0109] LiQ, LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Na, Li, Ca, Yb, Mg.

[0110] Example

[0111] In the following, the organic compounds of the present invention are representatively synthesized and applied together with corresponding comparative compounds to organic electroluminescent devices to test the device performance under the same conditions.

[0112] The following synthesis examples of the present invention illustratively provide specific synthesis methods for representative compounds. The solvents and reagents, intermediates, ethyl acetate, methanol, ethanol and other chemical reagents used in the following synthesis examples can all be purchased or customized from the domestic chemical product market, for example, from Sinopharm Reagent Company, Sigma-Aldrich Company, and J&K Reagent Company.

[0113] In addition, the mass spectrum characterization data in the following synthesis examples were obtained by testing a ZAB-HS mass spectrometer manufactured by Micromass, UK, under the following test conditions: direct injection, EI source, ionization voltage 70 eV, ionization temperature 250° C., acceleration voltage 6 kV, and resolution 1000.

[0114] Synthesis Example

[0115] Synthesis Example 1: Synthesis of T1

[0116]

[0117] Synthesis of intermediate T1-1:

[0118] At room temperature, 2,3,5,6-tetrafluorobenzonitrile (1.75 g, 10.0 mmol), 3-methylcarbazole (3.8 g, 21.0 mmol) and sodium carbonate (2.65 g, 25 mmol) and DMF (120 ml) were added to a 250 ml single-necked bottle, and the atmosphere was replaced and protected with nitrogen, and the reaction was allowed to proceed overnight at room temperature.

[0119] Stop the reaction, inject the reaction solution into water, add a certain amount of ammonium chloride solid, stir, solid precipitates, filter by suction, column chromatography, obtain 3.8g of white solid, yield 77.5%. Molecular mass determined by mass spectrometry: 497.6 (theoretical value: 497.1).

[0120] Synthesis of T1:

[0121] Add T1-1 (3.0 g, 6.03 mmol), carbazole (2.52 g, 15.07 mmol), sodium carbonate (1.92 g, 18.09 mmol) to a 100 ml three-necked flask and dissolve in 50 ml DMF. Replace with nitrogen three times and protect. Heat to 80°C and react for 16 hours.

[0122] Stop the reaction, inject the reaction solution into water, add a certain amount of ammonium chloride solid, stir, solid precipitates; filter, column chromatography, recrystallize, and obtain 1.51g of yellow solid, with a yield of 31.5%. Molecular mass determined by mass spectrometry: 791.6 (theoretical value: 791.3).

[0123] In Synthesis Examples 2-6, compounds T2, T6, T7, T9, and T12 were synthesized respectively, and the synthesis methods were similar to those in Synthesis Example 1.

[0124] Synthesis example 2

[0125] The reactant 3-methylcarbazole in Synthesis Example 1 was replaced with 3,6-dimethylcarbazole; T2 was synthesized in the same manner as in Synthesis Example 1. The molecular mass determined by mass spectrometry was 819.5 (theoretical value: 819.3).

[0126] Synthesis example 3

[0127] The reactant 3-methylcarbazole in Synthesis Example 1 was replaced with 3-isopropylcarbazole; T6 was synthesized in the same manner as in Synthesis Example 1. The molecular mass determined by mass spectrometry was 847.4 (theoretical value: 847.3).

[0128] Synthesis example 4

[0129] The reactant 3-methylcarbazole in Synthesis Example 1 was replaced with 3-methyl-6-ethylcarbazole; T7 was synthesized in the same manner as in Synthesis Example 1. The molecular mass determined by mass spectrometry was 847.4 (theoretical value: 847.3).

[0130] Synthesis example 5

[0131] The reactant 3-methylcarbazole in Synthesis Example 1 was replaced with 3-methyl-6-isobutylcarbazole; T9 was synthesized in the same manner as in Synthesis Example 1. The molecular mass determined by mass spectrometry was 903.5 (theoretical value: 903.4).

[0132] Synthesis example 6

[0133] The reactant 3-methylcarbazole in Synthesis Example 1 was replaced with 3-ethylcarbazole; T12 was synthesized in the same manner as in Synthesis Example 1. The molecular mass determined by mass spectrometry was 819.6 (theoretical value: 819.3).

[0134] Synthesis Example 7

[0135] The reactant 3-methylcarbazole in Synthesis Example 1 was replaced with 3,6-di-tert-butylcarbazole; T161 was synthesized in the same manner as in Synthesis Example 1. The molecular mass determined by mass spectrometry was 987.8 (theoretical value: 987.5).

[0136] Synthesis example 8

[0137] The reactant 3-methylcarbazole in Synthesis Example 1 was replaced by 4-methylcarbazole; carbazole was replaced by 9H-pyrido[2,3-B]indole; and T162 was synthesized in the same manner as in Synthesis Example 1. The molecular mass determined by mass spectrometry was 793.6 (theoretical value: 793.3).

[0138] Synthesis example 9

[0139] T165 was synthesized by replacing the reactant 3-methylcarbazole in Synthesis Example 1 with 2-methylcarbazole; the synthesis method was the same as that in Synthesis Example 1. The molecular mass determined by mass spectrometry was 791.8 (theoretical value: 791.3).

[0140] Synthesis example 10

[0141] The reactant carbazole in Synthesis Example 1 was replaced with 9H-pyrido[3,4-B]indole; T121 was synthesized in the same manner as in Synthesis Example 1. The molecular mass determined by mass spectrometry was 793.6 (theoretical value: 793.3).

[0142] Synthesis example 11

[0143] The reactant 3-methylcarbazole in Synthesis Example 1 was replaced by 3-propylcarbazole; carbazole was replaced by 9H-pyrido[3,4-B]indole, and T126 was synthesized in the same manner as in Synthesis Example 1. The molecular mass determined by mass spectrometry was 849.7 (theoretical value: 849.3).

[0144] Synthesis Example (Comparative Compound)

[0145] The synthesis method of comparative compound S2 refers to CN110759851A, and the specific structure is as follows:

[0146]

[0147] Example 1

[0148] Device Manufacturing Example 1: The process of preparing an organic electroluminescent device is as follows:

[0149] The glass plate coated with the ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in a mixed solvent of acetone:ethanol, baked in a clean environment to completely remove the water, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam;

[0150] Place the glass substrate with the anode in a vacuum chamber and evacuate to a vacuum of <1×10 -5Pa, on the above anode layer film, vacuum thermal evaporation was performed in order of 10nm of HT-4:HI-3 (97 / 3, w / w) mixture as a hole injection layer, 60nm of compound HT-4 as a hole transport layer, 5nm of compound HT-51 as an electron blocking layer; 40nm of compound PH54:T1 (100:40, w / w) binary mixture as a light-emitting layer; 5nm of PH-28 as a hole blocking layer, 25nm of compound ET-69:ET-57 (50 / 50, w / w) mixture as an electron transport layer, 1nm of LiF as an electron injection layer, and 150nm of metal aluminum as a cathode. The total evaporation rate of all organic layers and LiF was controlled at 0.1nm / sec, and the evaporation rate of the metal electrode was controlled at 1nm / sec.

[0151] The preparation process of device examples 2 to 14 and comparative example 1 is the same as that of device example 1, except that T1 in the light-emitting layer is replaced with the compounds listed in Table 1 below.

[0152] The organic electroluminescent device prepared by the above process was subjected to the following performance tests:

[0153] At the same brightness, the driving voltage and external quantum efficiency of the organic electroluminescent device prepared from the compound and the comparative material were measured using a digital source meter, a brightness meter and a PR650. Specifically, the voltage was increased at a rate of 0.1 V per second, and the brightness of the organic electroluminescent device was measured when it reached 1000 cd / m 2 The voltage at which the device is turned on is the driving voltage. At the same time, the external quantum efficiency (EQE%) of the device can be directly tested on PR650.

[0154] Table 1: Organic electroluminescent device performance is shown in the table below

[0155]

[0156]

[0157] As can be seen from Table 2, when the compound of the present invention is used as a dye, compared with the comparative example compound, its voltage is reduced, and the device efficiency is improved, showing excellent device performance. This may be due to the reduction of the peripheral alkyl group, which is conducive to carrier transport, so that the device voltage is reduced, and the balance of carrier transport is also improved, resulting in improved device efficiency. This is conducive to the practical application of the compound of the present invention.

[0158] The above experimental data show that the novel organic material of the present invention, as an electron blocking material for an organic electroluminescent device, has been significantly improved compared with the prior art, is an organic light-emitting functional material with good performance, and has broad application prospects.

[0159] The present invention illustrates the detailed method of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed method, that is, it does not mean that the present invention must rely on the above-mentioned detailed method to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. An organic compound, characterized in that Having the structure shown in formula (1), in: D 1 , D 2 are independently selected from the group represented by formula (2): X 1 ~X 8 Each independently selected from CH or CR 2 , R 2 is a group represented by the following formula (4), Where R a , R b , R c Each independently selected from hydrogen, C1-C9 alkyl, R a , R b , R c Connected to form a ring or not connected to form a ring, R a , R b , R c At least one of them is hydrogen, * represents the connection end with formula (2), X 1 ~X 4 1 of them is CR 2 ; D 3 , D 4 Independently selected from the group represented by formula (3): Y 1 ~Y 8 are independently selected from CH or N.

2. The organic compound according to claim 1, wherein X 5 ~X 8 All are CH, or one of them is CR 2 .

3. The organic compound according to claim 1, wherein X 1 ~X 4 1 of them is CR 2 , X 5 ~X 8 1 of them is CR 2 , and the R 2 Select the same group.

4. The organic compound according to claim 1, wherein X 3 and / or X 6 CR 2 , R 2 It is one selected from methyl, ethyl, propyl, isopropyl, isobutyl, cyclopentyl and cyclohexyl.

5. The organic compound according to claim 1 or 2, wherein The group represented by formula (2) is selected from the following groups, 6. The organic compound according to claim 2, D 3 With D 4 are the same group.

7. The organic compound according to claim 1, wherein Y 1 ~Y 8 All are CH, or one of them is N and the rest are CH.

8. The organic compound according to claim 1, wherein Y 1 ~Y 4 All are CH, or Y 1 ~Y 4 One or two of them are N and the rest are CH. Y 5 ~Y 8 All are CH, or Y 5 ~Y 8 One or two of them are N and the rest are CH.

9. The organic compound according to claim 1, wherein The group represented by formula (3) is selected from the following groups, 10. The organic compound according to claim 1, wherein the compound of general formula (1) is a compound having the following specific structure: 11 . An organic electroluminescent material, which is the compound according to claim 1 . 12 . A luminescent dye material, which is the compound according to claim 1 .

13. Use of the compound according to any one of claims 1 to 10 as a luminescent dye.

14. An organic electroluminescent device comprising a first electrode, a second electrode and one or more light-emitting functional layers inserted between the first electrode and the second electrode, wherein the light-emitting functional layer contains the compound according to any one of claims 1 to 10. 15 . The organic electroluminescent device according to claim 14 , wherein the plurality of light-emitting functional layers include a light-emitting layer, and the light-emitting layer contains the organic compound according to claim 1 .

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