Compounds for organic electroluminescence devices and use thereof

Abstract

This invention provides a compound for use in organic electroluminescent devices and its application, the compound having the structure shown in formula (I): L, L 1 L 2 Each is independently selected from single-bonded, substituted or unsubstituted C6-C30 arylene or substituted or unsubstituted C3-C30 heteroarylene; Ar 1 -Ar 2 Each is independently a substituted or unsubstituted C6-C30 aryl group or a substituted or unsubstituted C3-C30 heteroaryl group; X 1 ~X 11 Each independently selected from CR 1 Or N, the R 1 Each is independently selected from one of the following: hydrogen, cyano, nitro, hydroxyl, substituted or unsubstituted C1-C20 chain alkyl, C3-C20 cycloalkyl, C1-C20 alkoxy, C1-C20 silyl, C6-C60 aryl, and C3-C60 heteroaryl, wherein R 1 Each of the substituted or unsubstituted groups can be independently and optionally linked to form a ring; when the above-mentioned substituted or unsubstituted groups have substituents, the substituents are selected from one or more combinations of halogens, C1-C20 chain alkyl, C3-C20 cycloalkyl, C1-C20 alkoxy, C1-C20 thioalkoxy, C1-C20 silyl, cyano, nitro, hydroxyl, C6-C60 aryl, and C3-C60 heteroaryl.

Description

Technical Field

[0001] This invention relates to a novel class of compounds that can be used as electron blocking layers in organic EL devices. The invention is simple to prepare, can improve and balance carrier transport in the device, reduce device voltage, and improve luminous efficiency. Background Technology

[0002] In recent years, optoelectronic devices based on organic materials have become increasingly popular. The inherent flexibility of organic materials makes them ideal for fabrication on flexible substrates, allowing for the design and production of aesthetically pleasing and stylish optoelectronic products, offering unparalleled advantages over inorganic materials. Examples of such organic optoelectronic devices include organic light-emitting diodes (OLEDs), organic field-effect transistors, organic photovoltaic cells, and organic sensors. OLEDs, in particular, have developed rapidly and have already achieved commercial success in the information display field. OLEDs can provide highly saturated red, green, and blue colors, and full-color displays made with them do not require an additional backlight, offering advantages such as vibrant colors, thinness, and flexibility.

[0003] The core of an OLED device is a thin-film structure containing various 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, as well as light-emitting host materials and light-emitting guest materials (dyes). When an electric current is applied, electrons and holes are injected and transported to the light-emitting region, where they recombine, thereby generating excitons and emitting light.

[0004] Various organic materials have been developed and combined with unique device structures to improve carrier mobility, regulate carrier balance, break through electroluminescence efficiency barriers, and delay device decay. For quantum mechanical reasons, common fluorescent emitters primarily utilize singlet excitons generated when electrons and holes combine to emit light, and are still widely used in various OLED products. Some metal complexes, such as iridium complexes, can simultaneously utilize triplet and singlet excitons for light emission, and are called phosphorescent emitters, with energy conversion efficiencies up to four times higher than traditional fluorescent emitters. Thermally excited delayed fluorescence (TADF) technology promotes the transition from triplet to singlet excitons, achieving high luminescence efficiency without the use of metal complexes, while still effectively utilizing triplet excitons. Thermally excited sensitized fluorescence (TASF) technology uses materials with TADF properties to sensitize the emitter through energy transfer, also achieving high luminescence efficiency. Summary of the Invention

[0005] The problem the invention aims to solve

[0006] As OLED products gradually enter the market, people have increasingly higher requirements for their performance. Current OLED materials and device structures cannot fully solve the problems related to efficiency, cost, and other aspects of OLED products.

[0007] In view of the above needs, one of the objectives of the present invention is to provide a compound that, when applied in an OLED device, can improve luminous efficiency and reduce driving voltage.

[0008] Solution to the problem

[0009] Through careful consideration and continuous experimentation, the inventors of this invention discovered an ingenious molecular design scheme, thus completing this invention. Surprisingly, the compounds disclosed in this invention are highly suitable for application in OLEDs, enhancing device performance.

[0010] Specifically, the present invention proposes a compound characterized by having the structure shown in formula (I):

[0011]

[0012] Among them, L, L 1 L 2 Each is independently selected from single-bonded, substituted or unsubstituted C6-C30 arylene or substituted or unsubstituted C3-C30 heteroarylene;

[0013] Ar 1 -Ar 2 Each is independently a substituted or unsubstituted C6-C30 aryl group or a substituted or unsubstituted C3-C30 heteroaryl group;

[0014] X 1 ~X 11 Each independently selected from CR 1 Or N,

[0015] The R 1 Each of the following is independently selected from hydrogen, cyano, nitro, hydroxyl, 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 aryl, and substituted or unsubstituted C3-C60 heteroaryl, wherein R 1 Each can independently choose to connect with the connected aromatic ring or heteroaromatic ring to form a ring;

[0016] When the above-mentioned substituted or unsubstituted groups contain substituents, the substituents are selected from one or more combinations of halogens, C1-C20 chain alkyl, C3-C20 cycloalkyl, C1-C20 alkoxy, C1-C20 thioalkoxy, C1-C20 silyl, cyano, nitro, hydroxyl, C6-C60 aryl, and C3-C60 heteroaryl.

[0017] When the above-mentioned compounds of the present invention are used as electron blocking layers in organic EL devices, they can effectively reduce device voltage, improve device luminous efficiency, and increase device lifetime. The underlying principle is not yet clear, but it is speculated as follows: By attaching a specific aromatic amine group at a specific position in the trimelline parent structure, the carrier transport of the device can be improved and balanced, thereby increasing the device's luminous efficiency. Furthermore, by adjusting the -L-Ar content in the aromatic amine group, the HOMO / LUMO energy levels can be further optimized, refractive properties improved, and carrier mobility balanced, thereby further increasing the device's luminous efficiency and reducing the device voltage. Thus, a good prime material is obtained.

[0018] It is worth noting that the inventors further discovered that, although the reason is not yet clear, the compound of the present invention performs best as a prime material when a specific aromatic amine group is attached to the trimerene matrix structure. If more than one aromatic amine group is attached, the device performance is actually worse than when only one aromatic amine group is attached.

[0019] In this specification, the expression Ca to Cb represents that the group has a to b carbon atoms. Unless otherwise specified, the number of carbon atoms generally does not include the number of carbon atoms of the substituents.

[0020] In this specification, the way a ring structure is represented by "—" indicates that the connection site is any position on the ring structure where bonding can occur.

[0021] In this specification, "each independently" means that when there are multiple subjects, they may be the same or different from each other.

[0022] In this invention, unless otherwise specified, the description of chemical elements usually includes the concept of their isotopes. For example, the description of "hydrogen (H)" includes its isotope 1H (protium or H). 2 The concept of H (deuterium or D); carbon (C) includes... 12 C 13 C, etc., will not be elaborated further.

[0023] In this specification, heteroatoms generally refer to atoms or groups of atoms selected from N, O, S, P, Si and Se, preferably selected from N, O and S.

[0024] Examples of halogens in this specification include fluorine, chlorine, bromine, and iodine.

[0025] Unless otherwise specified, the chain alkyl groups mentioned in this invention include straight-chain alkyl groups and branched-chain alkyl groups. Specifically, substituted or unsubstituted C1-C30 chain alkyl groups are preferably substituted or unsubstituted C1-C16 chain alkyl groups, and more preferably substituted or unsubstituted C1-C10 chain alkyl groups. Examples of substituted or unsubstituted C1-C10 chain alkyl groups include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, n-pentyl, sec-pentyl, neopentyl, n-hexyl, neohexyl, n-heptyl, n-octyl, 2-ethylhexyl, etc.

[0026] In this invention, the cycloalkyl group includes monocycloalkyl and polycycloalkyl; wherein, monocycloalkyl refers to an alkyl group containing a single ring structure; polycycloalkyl refers to a structure composed of two or more cycloalkyl groups sharing one or more carbon atoms on a ring; examples of C3-C20 cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, etc.

[0027] In this specification, the substituted or unsubstituted C1-C20 alkoxy group is preferably a substituted or unsubstituted C1-C10 alkoxy group. Examples of C1-C10 alkoxy groups include: methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, isobutoxy, tert-butoxy, pentooxy, isopentoxy, hexoxy, heptoxy, octoxy, nonoxy, decoxy, undecoxy, dodecoxy, etc., among which methoxy, ethoxy, n-propoxy, isopropoxy, tert-butoxy, sec-butoxy, isobutoxy, isopentoxy, and isopentoxy are preferred, and methoxy is more preferred.

[0028] In this specification, the substituted or unsubstituted C1-C20 silanes and the substituted or unsubstituted C1-C10 silanes are examples of silanes substituted with groups listed in the above C1-C10 silanes, specifically including: methylsilane, dimethylsilane, trimethylsilane, ethylsilane, diethylsilane, triethylsilane, tert-butyldimethylsilane, tert-butyldiphenylsilane, etc.

[0029] In this invention, unless otherwise specified, aryl and heteroaryl groups include both monocyclic and fused-ring types.

[0030] In this invention, the substituted or unsubstituted C6-C30 aryl group is preferably a C6-C20 aryl group. A monocyclic aryl group refers to a molecule containing at least one phenyl group. When a molecule contains at least two phenyl groups, the phenyl groups are independent of each other and connected by a single bond. Examples include phenyl, biphenyl, and terphenyl. Specifically, the biphenyl group includes 2-biphenyl, 3-biphenyl, and 4-biphenyl; the terphenyl group includes p-terphenyl-4-yl, p-terphenyl-3-yl, p-terphenyl-2-yl, meta-terphenyl-4-yl, meta-terphenyl-3-yl, and meta-terphenyl-2-yl. A fused-ring aryl group refers to a molecule containing at least two aromatic rings, where the aromatic rings are not independent of each other but share two adjacent carbon atoms and are fused together. Examples include naphthyl, anthraceneyl, phenanthryl, indene, fluorenyl, fluoranyl, triphenylene, pyrene, perylene, etc. Naphthyl, 2-naphthyl, and their derivative groups, etc. The naphthyl includes 1-naphthyl or 2-naphthyl; the anthraceneyl is selected from 1-anthrayl, 2-anthrayl, and 9-anthrayl; the fluorenyl is selected from 1-fluorenyl, 2-fluorenyl, 3-fluorenyl, 4-fluorenyl, and 9-fluorenyl; the pyrene is selected from 1-pyrene, 2-pyrene, and 4-pyrene; the 2-tetraphenyl is selected from 1-2 ... The fluorene derivative group is selected from 9,9-dimethylfluorenyl, 9,9-diethylfluorenyl, 9,9-dipropylfluorenyl, 9,9-dibutylfluorenyl, 9,9-dipentylfluorenyl, 9,9-dihexylfluorenyl, 9,9-diphenylfluorenyl, 9,9-dinaphthylfluorenyl, 9,9'-spirodifluorenyl, and benzo[a]fluorenyl.

[0031] In this invention, the substituted or unsubstituted C3-C30 heteroaryl groups are preferably C3-C20 heteroaryl groups, more preferably C4-C16 heteroaryl groups, and even more preferably C5-C12 heteroaryl groups. A monocyclic heteroaryl group refers to a molecule containing at least one heteroaryl group. When a molecule contains one heteroaryl group and other groups (such as aryl, heteroaryl, alkyl, etc.), the heteroaryl group and the other groups are independent of each other and connected by a single bond. Examples of monocyclic heteroaryl groups include furanyl, thiophene, pyrrole, and pyridinyl. A fused-ring heteroaryl group refers to a molecule containing at least one aromatic heterocycle and an aromatic ring (aromatic heterocycle or aromatic ring), where the two are not independent of each other but share two adjacent atoms fused together. Examples of fused-ring heteroaryl groups include: benzofuranyl, benzothiophenyl, isobenzofuranyl, indolyl, dibenzofuranyl, dibenzothiophenyl, carbazoyl, acridineyl, isobenzofuranyl, isobenzothiophenyl, benzocarbazoyl, azircarbazoyl, phenothiazinyl, phenothiazinyl, 9-phenylcarbazoyl, 9-naphthylcarbazoyl, dibenzocarbazoyl, indolocarbazoyl, etc.

[0032] Specific examples of arylene groups in this invention can be exemplified by removing one hydrogen atom from the aforementioned aryl examples to obtain a divalent group. The number of carbon atoms in arylene groups includes, but is not limited to, C6, C8, C10, C12, C14, C16, C18, C20, C22, C24, C26, and C28. Specific examples of heteroarylene groups in this invention can be exemplified by removing one hydrogen atom from the aforementioned heteroaryl examples to obtain a divalent group.

[0033] In this invention, unless otherwise specified, the substituents do not fuse with the group they belong to. This is because the structure obtained after fusion is actually a conjugated system different from the original parent nucleus. Therefore, without verification, it should not be assumed that the fused system can achieve the technical effects of this invention.

[0034] In this invention, the "substituted or unsubstituted" group can replace one substituent or multiple substituents. When there are multiple substituents, they can be selected from different substituents. In this invention, when the same expression is used, they all have the same meaning, and the selection range of substituents is as shown above and will not be repeated one by one.

[0035] It should be noted that, for ease of explanation, the possible effects of each group / feature have been described separately in this application, but this does not mean that these groups / features act in isolation. In fact, the reason for achieving good performance is essentially the optimized combination of the entire molecule, and the result of the synergistic effect between the various groups.

[0036] In the compounds of this invention, Ar 1 and Ar 2 Preferably, each group is independently selected from one of the following groups: substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted fluorene, substituted or unsubstituted spirofluorene, substituted or unsubstituted dibenzofuran, substituted or unsubstituted dibenzothiophene, substituted or unsubstituted carbazole.

[0037] When the above-mentioned substituted or unsubstituted groups contain substituents, the substituents are selected from one or more combinations of halogens, C1-C20 chain alkyl, C3-C20 cycloalkyl, C1-C20 alkoxy, C1-C20 thioalkoxy, C1-C20 silyl, cyano, nitro, hydroxyl, C6-C60 aryl, and C3-C60 heteroaryl.

[0038] Ar1 and Ar2 are more preferably each independently selected from one of the following groups:

[0039]

[0040] In this context, * indicates a connection site.

[0041] Ar1 and Ar2 are further preferably each independently selected from one of the following groups:

[0042]

[0043] By setting Ar1 and Ar2 as the aforementioned groups, the driving voltage of organic electroluminescent devices using this compound can be further reduced, thereby improving current efficiency.

[0044] In the compounds of the present invention, X is preferred. 1 ~X 11 All are CR 1 R is preferred 1 Each of the following is independently selected from hydrogen, cyano, hydroxyl, substituted or unsubstituted C1-C10 chain alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C1-C20 silyl, substituted or unsubstituted C6-C30 aryl, and substituted or unsubstituted C3-C30 heteroaryl, wherein R 1 Each can independently choose to connect with the connected aromatic ring or heteroaromatic ring to form a ring;

[0045] More preferably R 1 Each is independently selected from one of hydrogen, methyl, tert-butyl, cyclohexyl, substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophene, substituted or unsubstituted fluorenyl, substituted or unsubstituted carbazolyl;

[0046] Further preferred are those independently selected from one of hydrogen, methyl, tert-butyl, cyclohexyl, phenyl, biphenyl, naphthyl, dibenzofuranyl, dibenzothiophenyl, fluorenyl, and carbazoleyl;

[0047] Further optimization of R 1 Each is independently selected from hydrogen or phenyl; R is the most preferred. 1 Both are hydrogen.

[0048] By X 1 ~X 11 By incorporating the aforementioned functional groups, the lifespan of organic electroluminescent devices using this compound can be improved.

[0049] In the compounds of the present invention, L is preferably a single bond, a substituted or unsubstituted phenylene, a substituted or unsubstituted biphenylene, a substituted or unsubstituted naphthylene, or a substituted or unsubstituted pyridylene.

[0050] L is more preferably a single bond, a phenylene group, a biphenylene group, a naphthylene group, or a pyridylene group;

[0051] L is further preferably a single bond or a phenylene oxide;

[0052] L is most preferably a single bond.

[0053] In the compounds of this invention, L 1 and L 2 Preferably, each is independently selected from one of the following: single bond, substituted or unsubstituted phenylene, substituted or unsubstituted biphenylene, substituted or unsubstituted naphthylene, substituted or unsubstituted dibenzofuranylene, substituted or unsubstituted dibenzothiopheneylene, substituted or unsubstituted fluoreneylene, and substituted or unsubstituted carbazolylene.

[0054] L 1 and L 2 More preferably, each is independently selected from one of the following: single bond, phenylene, biphenylene, naphthylene, dibenzofuranylene, dibenzothiopheneylene, fluoreneylene, and carbazolylene;

[0055] Further optimization of L 1 and L 2 Each is independently selected from single bonds and phenylene;

[0056] Optimal choice L 1 and L 2 All are single keys.

[0057] By setting L, L1, and L2 as the aforementioned groups, the driving voltage of organic electroluminescent devices using this compound can be further reduced, thereby improving current efficiency.

[0058] The compounds of the present invention preferably have any one of the following structures:

[0059]

[0060]

[0061]

[0062]

[0063]

[0064]

[0065]

[0066]

[0067] The object of this invention is to provide an application of the compound described in one of the objects, wherein the compound is used in an organic electroluminescent device.

[0068] The purpose of this invention is to provide an organic electroluminescent device, comprising a substrate, and an anode layer, a plurality of light-emitting functional layers, and a cathode layer sequentially formed on the substrate.

[0069] The light-emitting functional layer includes at least one of a hole injection layer, a hole transport layer, a light-emitting layer, an electron blocking layer, and an electron transport layer, wherein the hole transport layer contains at least one of the compounds described in one of the objectives.

[0070] Invention Effects

[0071] This invention designs a novel material structure based on triterpenene derivatives as an electron blocking layer for organic EL devices. By improving and balancing carrier transport, it can effectively reduce device voltage and increase luminous efficiency. Furthermore, by adjusting -L-Ar, it can further optimize the HOMO / LUMO energy levels, improve refractive properties, balance carrier mobility, and enhance device performance. Therefore, this novel material is a promising prime material. Detailed Implementation

[0072] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0073] Specifically, another technical solution of the present invention provides an organic electroluminescent device, including a substrate, and an anode layer, a plurality of light-emitting functional layers and a cathode layer sequentially formed on the substrate; the light-emitting functional layers include at least one of a hole injection layer, a hole transport layer, a light-emitting layer, an electron blocking layer and an electron transport layer, wherein the electron blocking layer contains at least one of the above-mentioned compounds.

[0074] An OLED includes a first electrode and a second electrode, and an organic material layer located between the electrodes. This organic material layer can be further divided into multiple regions. For example, the organic material layer may include a hole transport region, a light-emitting layer, and an electron transport region.

[0075] In specific embodiments, a substrate can be used below the first electrode or above the second electrode. The substrate is typically made of glass or polymer material with excellent mechanical strength, thermal stability, water resistance, and transparency. Furthermore, thin-film transistors (TFTs) can also be incorporated into the substrate used for displays.

[0076] The first electrode can be formed by sputtering or depositing the material to be used as the first electrode on a substrate. When the first electrode is used as the anode, it can be a transparent conductive oxide material such as indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (SnO2), zinc oxide (ZnO), or any combination thereof. When the first electrode is used as the cathode, it can be 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), or any combination thereof.

[0077] Organic material layers can be formed on electrodes using methods such as vacuum thermal evaporation, spin coating, and printing. The compounds used as organic material layers can be small organic molecules, large organic molecules, polymers, and combinations thereof.

[0078] The hole transport region is located between the anode and the emissive layer. The hole transport region can be a single-layer hole transport layer (HTL), including single-layer hole transport layers containing only one compound and single-layer hole transport layers containing multiple compounds. Alternatively, the hole transport region can be a multilayer structure including at least one 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 emissive layer.

[0079] The material for the hole transport region may be selected from, but is 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 as shown in HT-1 to HT-51 below; or any combination thereof.

[0080]

[0081]

[0082]

[0083] 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 be one or more compounds of HT-1 to HT-51 described above, or one or more compounds of HI-1 to HI-3 described below; it can also be one or more compounds of HT-1 to HT-51 doped with one or more compounds of HI-1 to HI-3 described below.

[0084]

[0085] The emissive layer includes luminescent dyes (i.e., dopants) that can emit different wavelengths of light, and may also include a host material. The emissive layer can be a monochromatic emissive layer emitting a single color such as red, green, or blue. Multiple monochromatic emissive layers of different colors can be arranged in a planar pattern according to pixel design, or they can be stacked together to form a colored emissive layer. When different colored emissive layers are stacked together, they can be separated from each other or connected to each other. The emissive layer can also be a single colored emissive layer that can simultaneously emit different colors such as red, green, and blue.

[0086] Depending on the technology used, the light-emitting layer material can be various, including fluorescent electroluminescent materials, phosphorescent electroluminescent materials, and thermally activated delayed fluorescence materials. An OLED device can employ a single light-emitting technology or a combination of different technologies. These different light-emitting materials, categorized by technology, can emit light of the same color or different colors.

[0087] In one aspect of the invention, the light-emitting layer employs fluorescent electroluminescence technology. The fluorescent host material of the light-emitting layer may be selected from, but is not limited to, one or more combinations of BFH-1 to BFH-17 listed below.

[0088]

[0089]

[0090] In one aspect of the invention, the light-emitting layer employs fluorescent electroluminescence technology. The fluorescent dopant of the light-emitting layer may be selected from, but is not limited to, one or more combinations of BFD-1 to BFD-24 listed below.

[0091]

[0092]

[0093] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. 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.

[0094]

[0095]

[0096]

[0097]

[0098] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The phosphorescent dopant of the light-emitting layer may be selected from, but not limited to, one or more combinations of GPD-1 to GPD-47 listed below.

[0099]

[0100]

[0101] Where D stands for deuterium.

[0102] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The phosphorescent dopant of the light-emitting layer may be selected from, but not limited to, one or more combinations of RPD-1 to RPD-28 listed below.

[0103]

[0104] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The phosphorescent dopant of the light-emitting layer may be selected from, but not limited to, one or more combinations of YPD-1 to YPD-11 listed below.

[0105]

[0106]

[0107] In one aspect of the invention, the light-emitting layer employs thermally activated delayed fluorescence emission technology. 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 described above.

[0108] In one aspect of the invention, the luminescent layer employs thermally activated delayed fluorescence emission technology. The fluorescent dopant in the luminescent layer may be selected from, but is not limited to, one or more combinations of TDE1-TDE37 listed below.

[0109]

[0110]

[0111] 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 employ, but is not limited to, one or more compounds of HT-1 to HT-51 described above, or one or more compounds of PH-47 to PH-77 described above; or a mixture of one or more compounds of HT-1 to HT-51 and one or more compounds of PH-47 to PH-77 may be employed.

[0112] The OLED organic material layer may also include an electron transport region between the light-emitting layer and the cathode. The electron transport region can be a single-layer electron transport layer (ETL), including single-layer electron transport layers containing only one compound and single-layer electron transport layers containing multiple compounds. Alternatively, the electron transport region can be a multilayer structure including at least one of an electron injection layer (EIL), an electron transport layer (ETL), and a hole blocking layer (HBL).

[0113] In one aspect of the present invention, the electron transport layer material may be selected from, but not limited to, one or more combinations of ET-1 to ET-73 listed below.

[0114]

[0115]

[0116]

[0117] 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 employ, but is not limited to, one or more compounds of ET-1 to ET-73, or one or more compounds of PH-1 to PH-46; or a mixture of one or more compounds of ET-1 to ET-73 and one or more compounds of PH-1 to PH-46 may be employed.

[0118] The device may also include an electron injection layer located between the electron transport layer and the cathode, and the electron injection layer material includes, but is not limited to, one or more combinations of the following.

[0119] LiQ, LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Na, Li, Ca, Mg, Yb.

[0120] The representative synthetic routes of the compounds of this invention are as follows:

[0121]

[0122] Synthesis example

[0123] Synthesis Example 1: Synthesis of P13

[0124]

[0125] Under a nitrogen atmosphere, 20.00 g of 1-aminotriptene, 17.31 g of 4-bromobiphenyl, 0.54 g of [1,1′-bis(diphenylphosphino)ferrocene]palladium dichloride (Pd(dppf)Cl2), 0.61 g of 2-dicyclohexylphosphine-2′,6′-dimethoxybiphenyl (s-phos), 14.27 g of sodium tert-butoxide (t-BuONa), and 300 ml of toluene (Tol) were placed in a 1 L reaction vessel and reacted at 100 °C for 12 h. After the reaction was complete, the reaction solution was cooled to room temperature and extracted three times with ethyl acetate / water. The upper organic phases were combined and concentrated. Intermediate P13-1 (19.60 g) was obtained by column chromatography. Calculated molecular weight: 421.2, Measured M / Z: 422.2 [M+H] + .

[0126]

[0127] Under a nitrogen atmosphere, 18.00 g of P13-1, 11.66 g of 2-bromo-9,9'-dimethylfluorene, 0.39 g of tris(dibenzylacetone)dipalladium (Pd2(dba)3), 0.35 g of 2-dicyclohexylphosphine-2′,6′-dimethoxybiphenyl (s-phos), 8.21 g of sodium tert-butoxide (t-BuONa), and 300 ml of toluene (Tol) were placed in a 1 L reaction vessel and reacted at 110 °C for 12 h. After the reaction was complete, the reaction solution was cooled to room temperature and extracted three times with ethyl acetate / water. The upper organic phases were combined and concentrated. Column chromatography was used to separate compound P13 (10.20 g). Calculated molecular weight: 613.3, Measured M / Z: 614.3 [M+H] + .

[0128] Synthesis Example 2: Synthesis of P25

[0129] Replacing 2-bromo-9,9'-dimethylfluorene in Synthesis Example 1 with an equal molar amount of 3-bromodibenzofuran, while keeping other parameters unchanged, yielded compound P25. Calculated molecular weight: 587.2; Measured molecular weight (M / Z): 588.2 [M+H] + .

[0130] Synthesis Example 3: Synthesis of P37

[0131] Replacing 2-bromo-9,9'-dimethylfluorene in Synthesis Example 1 with an equal molar amount of 3-bromodibenzothiophene, while keeping other parameters unchanged, yielded compound P37. Calculated molecular weight: 603.2, Measured M / Z: 604.2 [M+H] + .

[0132] Synthesis Example 4: Synthesis of P50

[0133] Replacing 2-bromo-9,9'-dimethylfluorene in Synthesis Example 1 with an equal molar amount of N-phenyl-3-bromocarbazole, while keeping other parameters unchanged, yielded compound P50. Calculated molecular weight: 662.3, Measured M / Z: 663.3 [M+H] + .

[0134] Synthesis Example 5: Synthesis of P60

[0135]

[0136] Under a nitrogen atmosphere, 15.00 g of 1-aminotriptene, 30.43 g of 2-bromo-9,9'-dimethylfluorene, 0.51 g of tris(dibenzylacetone)dipalladium (Pd2(dba)3), 0.46 g of 2-bicyclohexylphosphine-2′,6′-dimethoxybiphenyl (s-phos), 10.70 g of sodium tert-butoxide (t-BuONa), and 400 ml of toluene (Tol) were placed in a 1 L reaction vessel and reacted at 110 °C for 12 h. After the reaction was complete, the reaction solution was cooled to room temperature and extracted three times with ethyl acetate / water. The upper organic phases were combined and concentrated. Compound P6012.70 g was obtained by column chromatography. Calculated molecular weight: 653.3, Measured M / Z: 654.3 [M+H] + .

[0137] Synthesis Example 6: Synthesis of P74

[0138]

[0139] Under a nitrogen atmosphere, 20.00 g of 4-bromotriptene-1-amine, 7.00 g of phenylboronic acid, 0.66 g of tetrakis(triphenylphosphine)palladium (Pd(PPh3)4), 15.87 g of potassium carbonate (K2CO3), 300 ml of 1,4-dioxane, and 100 ml of distilled water were placed in a 1 L reaction vessel and reacted at 100 °C for 12 h. After the reaction was complete, the reaction solution was cooled to room temperature and extracted three times with ethyl acetate / water. The upper organic phases were combined and concentrated. 14.50 g of compound P74-1 was obtained by column chromatography. Calculated molecular weight: 345.2; Measured molecular weight (M / Z): 346.2 [M+H]. + .

[0140]

[0141] Under a nitrogen atmosphere, 14.00 g of P74-1, 22.14 g of 2-bromo-9,9'-dimethylfluorene, 0.37 g of tris(dibenzylacetone)dipalladium (Pd2(dba)3), 0.33 g of 2-dicyclohexylphosphine-2′,6′-dimethoxybiphenyl (s-phos), 7.79 g of sodium tert-butoxide (t-BuONa), and 300 ml of toluene (Tol) were placed in a 1 L reaction vessel and reacted at 110 °C for 12 h. After the reaction was complete, the reaction solution was cooled to room temperature and extracted three times with ethyl acetate / water. The upper organic phases were combined and concentrated. Column chromatography was used to separate compound P74 (11.40 g). Calculated molecular weight: 729.3; Measured molecular weight (M / Z): 730.3 [M+H]. + .

[0142]

[0143] Synthesis Example 7: Synthesis of P76

[0144] Under a nitrogen atmosphere, 20.00 g of 1-bromotriptene, 8.22 g of p-aminophenylboronic acid, 0.69 g of tetrakis(triphenylphosphine)palladium (Pd(PPh3)4), 16.59 g of potassium carbonate (K2CO3), 300 ml of 1,4-dioxane, and 100 ml of distilled water were placed in a 1 L reaction vessel and reacted at 100 °C for 12 h. After the reaction was complete, the reaction solution was cooled to room temperature and extracted three times with ethyl acetate / water. The upper organic phases were combined and concentrated. Column chromatography was used to separate compound P76-1 (14.20 g). Calculated molecular weight: 345.2; Measured molecular weight (M / Z): 346.2 [M+H]. + .

[0145]

[0146] Under a nitrogen atmosphere, 14.00 g of P76-1, 18.89 g of 4-bromobiphenyl, 0.37 g of tris(dibenzylacetone)dipalladium (Pd2(dba)3), 0.33 g of 2-dicyclohexylphosphine-2′,6′-dimethoxybiphenyl (s-phos), 7.79 g of sodium tert-butoxide (t-BuONa), and 300 ml of toluene (Tol) were placed in a 1 L reaction vessel and reacted at 110 °C for 12 h. After the reaction was complete, the reaction solution was cooled to room temperature and extracted three times with ethyl acetate / water. The upper organic phases were combined and concentrated. 9.70 g of compound P76 was obtained by column chromatography. Calculated molecular weight: 649.3, Measured M / Z: 650.3 [M+H] + .

[0147] Synthesis Example 8: Synthesis of P78

[0148] Replacing 2-bromo-9,9'-dimethylfluorene in Synthesis Example 1 with an equimolar amount of 3-(4-bromophenyl)-9-phenylcarbazole, while keeping everything else unchanged, yielded compound P78. Calculated molecular weight: 738.3, Measured M / Z: 739.3 [M+H] + .

[0149] Synthesis Example 9: Synthesis of P79

[0150] Replacing 2-bromo-9,9'-dimethylfluorene in Synthesis Example 5 with an equal molar amount of bromobenzene, while keeping everything else unchanged, yielded compound P79. Calculated molecular weight: 421.2, Measured M / Z: 422.2 [M+H] + .

[0151] Synthesis Example 10: Synthesis of P5

[0152] Replacing 2-bromo-9,9'-dimethylfluorene in Synthesis Example 5 with an equal molar amount of 4-bromobiphenyl, while keeping everything else unchanged, yielded compound P5. Calculated molecular weight: 573.3, Measured M / Z: 574.3 [M+H] + .

[0153] The fabrication process of the organic electroluminescent device in this embodiment is as follows:

[0154] Example 1

[0155] This embodiment provides an organic electroluminescent device, and the specific fabrication process is as follows:

[0156] 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 acetone:ethanol mixed solvent, baked in a clean environment until all moisture was removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam.

[0157] The glass substrate with the anode was placed in a vacuum chamber and evacuated to a vacuum level of <1×10⁻⁶. -5 On the aforementioned anolyte film, a 10 nm HT-4:HI-3 (97 / 3, w / w) mixture was vacuum thermally deposited as a hole injection layer, a 60 nm HT-4 compound as a hole transport layer, a 35 nm P13 compound as an electron blocking layer, a 40 nm PH-61:PH-3:GPD-12 (100:100:20, w / w / w) ternary mixture as a light-emitting layer, a 25 nm ET-69:ET-57 (50 / 50, w / w) mixture as an electron transport layer, a 1 nm LiF layer as an electron injection layer, and a 150 nm aluminum metal as a cathode. The total deposition rate of all organic layers and LiF was controlled at 0.1 nm / s, and the deposition rate of the metal electrode was controlled at 1 nm / s.

[0158] Examples 2 to 7 were fabricated using the same method as Example 1, except that P13 in the electron blocking layer was replaced with P25, P37, P50, P60, P74, P76, P79, and P5, respectively.

[0159] Comparative Examples 1 to 3 were prepared using the same method as Example 1, except that P13 in the electron blocking layer was replaced with CCP-1, CCP-2, and CCP-3, respectively.

[0160] The structures of CCP-1, CCP-2, and CCP-3 are shown below:

[0161]

[0162] Performance testing

[0163] The organic electroluminescent devices prepared by the above process were subjected to the following performance measurements:

[0164] Under the same brightness, the driving voltage, current efficiency, and lifetime of the organic electroluminescent devices prepared in Examples 1-10 and Comparative Examples 1-3 were measured using a digital source meter and a luminance meter. Specifically, the voltage was increased at a rate of 0.1V per second, and the measurement was performed when the brightness of the organic electroluminescent device reached 10000 cd / m². 2 The voltage at that time is the driving voltage, and the current density at that time is also measured; the ratio of brightness to current density is the current efficiency. The measured performance of the organic electroluminescent device is shown in Table 1.

[0165] Table 1

[0166] Compound numbering <![CDATA[Required brightness cd / m 2 > Voltage (V) Current efficiency (cd / A) Comparative Example 1 CCP-1 10000 4.28 50.22 Comparative Example 2 CCP-2 10000 4.71 52.32 Comparative Example 3 CCP-3 10000 5.39 48.72 Example 1 P13 10000 3.93 62.08 Example 2 P25 10000 4.01 62.11 Example 3 P37 10000 4.07 61.46 Example 4 P50 10000 3.98 61.28 Example 5 P60 10000 3.95 61.67 Example 6 P74 10000 3.96 61.54 Example 7 P76 10000 4.11 61.39 Example 8 P78 10000 4.06 61.16 Example 9 P79 10000 4.15 59.73 Example 10 P5 10000 4.04 61.88

[0167] The above results show that the novel organic material of the present invention can effectively reduce the start-up voltage and improve the current efficiency when used in organic electroluminescent devices, and is a high-performance green photoelectron blocking layer material.

[0168] Although the invention has been described in conjunction with embodiments, the invention is not limited to the above embodiments. It should be understood that various modifications and improvements can be made by those skilled in the art under the guidance of the inventive concept, and the appended claims summarize the scope of the invention.

Claims

1. An electron blocking layer material, characterized in that, It is an organic compound having the structure shown in formula (I): Wherein, L is a single bond, phenylene, biphenylene, or naphthylene. 1 and L 2 Each is independently selected from one of the following: single bond, phenylene, biphenylene, naphthylene, and fluorene; Ar 1 and Ar 2 Each group is independently selected from one of the following groups: Where * represents a connection site; X 1 ~X 11 Each independently selected from CR 1 The R 1 Each is independently selected from one of hydrogen, methyl, tert-butyl, cyclohexyl, phenyl, biphenyl, naphthyl, dibenzofuranyl, dibenzothiophene, fluorenyl, and carbazoleyl.

2. The electron blocking layer material according to claim 1, characterized in that, Ar 1 and Ar 2 Each group is independently selected from one of the following groups:

3. The electron blocking layer material according to claim 1, characterized in that, R 1 Each is independently selected from hydrogen or phenyl.

4. The electron blocking layer material according to claim 1, characterized in that, R 1 Both are hydrogen.

5. The electron blocking layer material according to claim 1, characterized in that, L represents a single bond or a phenylene group.

6. The electron blocking layer material according to claim 1, characterized in that, L stands for a single bond.

7. The electron blocking layer material according to claim 1, characterized in that, L 1 and L 2 All are single keys.

8. An electron blocking layer material having a compound with the structure shown below:

9. The application of the electron blocking layer material according to any one of claims 1 to 8 in organic electroluminescent devices.

10. An organic electroluminescent device, comprising a substrate, and an anode layer, a plurality of light-emitting functional layers, and a cathode layer sequentially formed on the substrate. The light-emitting functional layer includes at least one of a hole injection layer, a hole transport layer, a light-emitting layer, an electron blocking layer, and an electron transport layer, wherein the electron blocking layer contains at least one electron blocking layer material as described in any one of claims 1 to 8.

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