A composition material and an organic electroluminescent device using the same

Abstract

The present application relates to a kind of composition materials for organic electroluminescence device and the organic electroluminescence device using it, the organic electroluminescence device includes anode layer, cathode layer and the organic layer between the anode layer and cathode layer;The organic light-emitting layer contains the composition material formed by the compound represented by formula (I) and the compound represented by formula (II) together.Wherein compound (I) is hole type host material, has good hole transport capacity, compound (II) is electron type host material, mainly responsible for electron transmission in light-emitting layer, the light-emitting layer formed by two considerations hole and electron transmission, the comprehensive performance of device can be obviously improved by the use of two.

Description

Technical Field

[0001] This invention belongs to the field of organic electroluminescence technology, specifically relating to a composition material and an organic electroluminescent device using the same. Background Technology

[0002] The core of an organic light-emitting diode (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.

[0003] In recent years, industry professionals have made continuous attempts and explorations to improve the efficiency and stability of devices. Among them, the main approach is to seek new materials to improve device performance. A large number of novel materials have been developed and applied to organic electroluminescent devices. Although they have improved device performance to some extent, they still suffer from the problem of large accumulation of charge carriers at the interface and low device efficiency.

[0004] Therefore, there is an urgent need in this field to develop organic electroluminescent devices with higher performance. Summary of the Invention

[0005] In view of the shortcomings of the prior art, one of the objectives of the present invention is to provide a composition material and an organic electroluminescent device using the same, which can effectively improve the efficiency and lifespan of the device.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] This invention provides a compositional material for an organic electroluminescent device, the compositional material comprising a compound represented by formula (I) and a compound represented by formula (II):

[0008]

[0009] In formula (Ⅰ), L1 and L2 are each independently selected from one of single bond, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl, and L3 is selected from one of substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl.

[0010] Ar1 and Ar2 are independently selected from one of the substituted or unsubstituted C6-C30 aryl groups and the substituted or unsubstituted C3-C30 heteroaryl groups, respectively, and Ar3 is selected from the substituted or unsubstituted nitrogen-containing C3-C30 heteroaryl group.

[0011] When Ar1, Ar2, Ar3, L1, L2, and L3 have substituent groups, the substituent groups are selected from one or a combination of two of the following: deuterium, halogen, cyano, nitro, hydroxyl, amino, aldehyde, ester, C1-C30 chain alkyl, C1-C30 alkoxy, C3-C20 cycloalkyl, C3-C20 heterocycloalkyl, C6-C60 aryl, and C3-C60 heteroaryl.

[0012]

[0013] In formula (II):

[0014] Ar4 and Ar5 are each independently selected from one of the substituted or unsubstituted C6-C30 aryl groups or the substituted or unsubstituted C3-C30 heteroaryl groups;

[0015] L is selected from one of the following: single bond, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl;

[0016] R1 and R2 are each independently selected from one of the following: substituted or unsubstituted C1-C20 chain alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C6-C30 aryl, or substituted or unsubstituted C3-C30 heteroaryl; R1 and R2 may or may not be connected.

[0017] R3 and R4 represent a single substituted group up to the maximum permissible number of substituted groups, and adjacent substituted groups may or may not be connected; R3 and R4 are each independently 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.

[0018] When Ar4, Ar5, L, R1, R2, R3, and R4 have substituent groups, the substituent groups are selected from one or a combination of two of the following: deuterium, halogen, cyano, nitro, hydroxyl, amino, aldehyde, ester, C1-C30 chain alkyl, C1-C30 alkoxy, C3-C20 cycloalkyl, C3-C20 heterocycloalkyl, C6-C60 aryl, and C3-C60 heteroaryl.

[0019] The term "compositional material for an organic electroluminescent device" in this invention disclosure means that at least two materials that can be used in an organic electroluminescent device are present together or are prepared to be present together. In this document, "present together" means not only that the at least two materials are mixed but also that the at least two materials are separate from each other. Furthermore, the concept of compositional material for an organic electroluminescent device encompasses materials included before (e.g., before vapor deposition) and materials included after (e.g., after vapor deposition) in the organic electroluminescent device. For example, compositional material for an organic electroluminescent device may include at least two of hole injection materials, hole transport materials, hole assist materials, luminescence assist materials, electron blocking materials, luminescent materials (host materials and / or dopant materials), electron buffer materials, hole blocking materials, electron transport materials, and electron injection materials. The compositional material for an organic electroluminescent device may comprise at least two hole injection materials, at least two hole transport materials, at least two hole assist materials, at least two light-emitting assist materials, at least two electron blocking materials, at least two light-emitting materials (host material and / or dopant material), at least two electron buffer materials, at least two hole blocking materials, at least two electron transport materials, and / or at least two electron transport materials. The compositional material for an organic electroluminescent device disclosed herein may be contained in any layer constituting the organic electroluminescent device. The at least two materials contained in the compositional material may be contained together in one layer or may be contained separately in different layers. When at least two materials are contained in one layer, they may be mixed and evaporated to form a layer, or they may be co-evaporated separately and simultaneously to form a layer.

[0020] 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.

[0021] In this specification, the expression Ca~Cb represents that the group has a~b carbon atoms. Unless otherwise specified, the number of carbon atoms generally does not include the number of carbon atoms of the substituents.

[0022] In this specification, "each independently" means that when there are multiple subjects, they may be the same or different from each other.

[0023] In this invention, the description of chemical elements, unless otherwise specified, usually includes the concept of their isotopes. For example, the description of "hydrogen (H)" includes the concept of its isotopes 1H (protium or H) and 2H (deuterium or D); carbon (C) includes 12C, 13C, etc., which will not be elaborated further.

[0024] The heteroatoms in the heteroaryl group of this invention generally refer to atoms or groups of atoms selected from N, O, S, P, Si and Se, preferably selected from N, O and S.

[0025] Examples of halogens in this specification include fluorine, chlorine, bromine, and iodine.

[0026] In this invention, the substituted or unsubstituted C6-C60 aryl groups and the substituted or unsubstituted C6-C30 aryl groups both include monocyclic aryl groups and fused-ring aryl groups, preferably C6-C20 aryl groups. 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, exemplarily such as 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 fused together. Examples of such groups include naphthyl, anthraceneyl, phenanthryl, indene, fluorenyl, fluoranyl, triphenylene, pyrene, peryl, phenyl, tetraphenyl, and their derivatives. The naphthyl group includes 1-naphthyl or 2-naphthyl; the anthraceneyl group is selected from 1-anthrayl, 2-anthrayl, and 9-anthrayl; the fluorenyl group is selected from 1-fluorenyl, 2-fluorenyl, 3-fluorenyl, 4-fluorenyl, and 9-fluorenyl; the pyreneyl group is selected from 1-pyrene, 2-pyrene, and 4-pyrene; and the tetraphenyl group is selected from 1-tetraphenyl, 2-tetraphenyl, and 9-tetraphenyl. 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.

[0027] In this invention, the substituted or unsubstituted C3-C60 heteroaryl groups and the substituted or unsubstituted C3-C30 heteroaryl groups both include monocyclic heteroaryl groups and fused-ring heteroaryl groups, preferably C4-C20 heteroaryl groups, and 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 pyridyl. A fused-ring heteroaryl group refers to a molecule containing at least one aromatic heterocycle and an aromatic ring (aromatic heterocycle or aromatic ring), and 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.

[0028] 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. The substituted or unsubstituted C3-C30 cycloalkyl groups mentioned in this invention are preferably substituted or unsubstituted C3-C20 cycloalkyl groups, and more preferably substituted or unsubstituted C3-C10 cycloalkyl groups, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, n-hexyl, n-octyl, isobutyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, tert-pentyl, cyclohexyl, adamantyl, etc.

[0029] In this invention, the way the ring structure is represented by "—" indicates that the connection point is located at any position on the ring structure where bonding can occur.

[0030] More preferably, Ar3 is selected from substituted or unsubstituted heteroaryl groups containing carbazole groups;

[0031] More preferably, in formula (I), Ar3 is selected from one of the following groups, either substituted or unsubstituted:

[0032] Wherein, R is selected from one or a combination of two of the following: C1-C20 chain alkyl, C3-C20 cycloalkyl, C6-C30 aryl, and C3-C30 heteroaryl;

[0033] When Ar3 has a substituent group, the substituent group is selected from one or a combination of two of the following: chain alkyl groups of C1 to C30, cycloalkyl groups of C3 to C20, aryl groups of C6 to C60, and heteroaryl groups of C3 to C60.

[0034] Furthermore, in formula (Ⅰ): L1 and L2 are each independently selected from single bonds, and L3 is selected from phenyl, biphenyl, terphenyl, naphthyl, dibenzofuranyl or dibenzothiopheneyl;

[0035] Preferably, L3 is selected from phenyl.

[0036] Furthermore, the compound represented by formula (Ⅰ) has any one of the structures shown in P1-P121:

[0037]

[0038]

[0039]

[0040] .

[0041] More preferably, the compound represented by formula (II) in this invention is shown in formula (II-1):

[0042] ;

[0043] R1 and R2 are each independently selected from methyl, phenyl, or spirofluorenyl; R1 and R2 may or may not be connected.

[0044] And / or, the L is selected from one of single bond, C6-C30 aryl, and C3-C30 heteroaryl; preferably, L is selected from phenyl, naphthyl, pyridyl, 2-phenylpyridyl or isoquinolinyl;

[0045] And / or, each of the Ar4 and Ar5 is independently selected from the following groups, substituted or unsubstituted: phenyl, naphthyl, anthracene, phenanthrene, biphenyl, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, spirofluorenyl, benzo[fluorenyl], benzo[furanyl], benzo[thiophene], dibenzo[furanyl] or dibenzo[thiophene].

[0046] More preferably, the compound represented by formula (II) in this invention has any one of the structures shown as N1 to N172:

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055]

[0056] .

[0057] This invention proposes a compositional material for organic electroluminescent devices, comprising a compound represented by formula (I) and a compound represented by formula (II). Organic electroluminescent devices employing this type of compositional material of the present invention simultaneously utilize compound (I) and compound (II) as functional materials in the organic layer.

[0058] Through extensive experimental design and research, the applicant discovered that compounds (I) and (II) are particularly suitable for use together as light-emitting layer materials in the organic layer of a device. This is because compound (I) can regulate the injection and transport of holes within the light-emitting layer, thereby controlling the carrier recombination region in the light-emitting layer. Furthermore, compound (I) possesses a high spatial packing structure, while compound (II) exhibits high molecular planar expansion characteristics and excellent electron transport performance. Therefore, when compounds (I) and (II) are used together, the faster electron transport characteristic of compound (II) can be coordinated, effectively controlling the balance between hole and electron transport. This allows the electron-hole recombination center in the light-emitting layer to be located at the center of the light-emitting layer, thereby effectively improving the device's efficiency and lifetime. The general formula (II) compound of this invention has a lower triplet energy level T1, reducing the energy difference with the guest dye, resulting in less energy loss during energy transfer and improving exciton utilization. Compared to higher energy level electronic host materials, it has higher efficiency.

[0059] The present invention also proposes an organic electroluminescent device, which includes an anode layer, a cathode layer, and an organic layer disposed between the anode layer and the cathode layer, wherein the organic layer includes a composition material formed by a compound represented by formula (I) and a compound represented by formula (II).

[0060] More preferably, the compound represented by formula (I) has any one of the structures shown in P1-P121, and the compound represented by formula (II) has any one of the structures shown in N1-N183.

[0061] Further preferably, the organic layer in the organic electroluminescent device of the present invention includes a light-emitting layer, which includes a composition material formed by a compound represented by formula (I) and a compound represented by formula (II); wherein the mass percentage of the compound represented by formula (I) and the compound represented by formula (II) in the composition material is 10%-200%; preferably, the mass percentage of the compound represented by formula (I) and the compound represented by formula (II) is 50%-150%.

[0062] Further preferably, the light-emitting layer of the organic electroluminescent device of the present invention includes a composition material formed by a combination material formed by any one of the compounds shown in structures P1-P121 and any one of the compounds shown in structures N1-N183; wherein the mass percentage of any one of the compounds shown in structures P1-P121 and any one of the compounds shown in structures N1-N183 in the composition material is 10%-200%; preferably, the mass percentage of any one of the compounds shown in structures P1-P121 and any one of the compounds shown in structures N1-N183 is 50%-150%.

[0063] Specifically, in a preferred embodiment of the present invention, the organic electroluminescent device is prepared by using a mixture of the compound represented by formula (I) and the compound represented by formula (II) as the dual-emissivity material in the light-emitting layer of the device. The mass percentage of the compound represented by formula (I) to the compound represented by formula (II) can preferably be 1.5:1, 1:1, 1:1.5, etc.

[0064] More preferably, the organic layer in the organic electroluminescent device of the present invention further includes one or more of a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer.

[0065] More preferably, the thickness of the light-emitting layer in the organic electroluminescent device of the present invention is 10-60 nm, such as 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, etc., preferably 20-50 nm, and more preferably 40 nm.

[0066] In the organic electroluminescent device of the present invention, the organic layer further includes one or more of a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer.

[0067] Meanwhile, the present invention also provides a display device, wherein the display device includes the organic electroluminescent device as described above. Attached Figure Description

[0068] Figure 1 This is a schematic diagram of the structure of an organic electroluminescent device provided in a specific embodiment of the present invention;

[0069] Among them, 1-glass substrate, 2-anode layer, 3-hole injection layer, 4-hole transport layer, 5-electron blocking layer, 6-light emitting layer, 7-electron transport layer, 8-electron injection layer, 9-cathode layer, and 10-external power supply. Detailed Implementation

[0070] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0071] 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.

[0072] The first electrode can be formed by sputtering or depositing the material 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.

[0073] 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.

[0074] 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.

[0075] 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, wherein the aromatic amine derivatives are compounds shown below as HT-1 to HT-52; or any combination thereof.

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083] .

[0084] 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-52 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-52 doped with one or more compounds of HI-1 to HI-3 described below.

[0085] .

[0086] The emissive layer includes a host material and dopants that emit different wavelengths of light. 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 simultaneously emits different colors such as red, green, and blue.

[0087] Depending on the technology used, the light-emitting layer material can be phosphorescent photoluminescent material. An OLED device can employ a single light-emitting technology or a combination of different light-emitting technologies. These different light-emitting materials, categorized by technology, can emit light of the same color or different colors.

[0088] In this type of device, the material of the light-emitting layer is a phosphorescent material selected from a combination of compound (I) and compound (II) of this invention.

[0089] 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.

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097]

[0098]

[0099] .

[0100] 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.

[0101]

[0102]

[0103]

[0104]

[0105]

[0106] .

[0107] 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.

[0108]

[0109] .

[0110] The organic material layer of an OLED 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 electron injection layer (EIL) and an electron transport layer (ETL).

[0111] 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.

[0112]

[0113]

[0114]

[0115]

[0116]

[0117]

[0118]

[0119]

[0120]

[0121]

[0122]

[0123]

[0124]

[0125]

[0126]

[0127]

[0128]

[0129]

[0130] .

[0131] 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.

[0132] LiQ, LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Na, Li, Ca, Mg, Yb.

[0133] In this invention, the synthesis methods of the compounds represented by formula (I) and formula (II) are both prior art. Specifically, the synthesis method of compound (I) is described in patent application number 202010624467.9, and the synthesis method of compound (II) is described in patents CN113892196A and CN113924665A. The synthesis method of the comparative compound D-N1 is described in patent TW202026399A.

[0134] This invention provides an organic electroluminescent device, the structure of which is as follows: Figure 1 As shown, it includes a glass substrate 1, an anode layer 2, a hole injection layer 3, a hole transport layer 4, an electron blocking layer 5, a light-emitting layer 6, an electron transport layer 7, an electron injection layer 8, a cathode layer 9, and an external power supply 10.

[0135] The method for preparing the first group of organic electroluminescent devices of the present invention is as follows:

[0136] 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.

[0137] The glass substrate with the anode was placed in a vacuum chamber and evacuated to a vacuum level of <1×10⁻⁶. -5 Pa, on the above-mentioned anodic layer 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 compound HT-4 as a hole transport layer, and a 60 nm compound HT52 as an electron blocking layer.

[0138] A light-emitting layer with a thickness in the range of 10-60 nm was prepared. A mixture of compounds represented by formula (I) as the first host and compounds represented by formula (II) as the second host was used as a dual-light-emitting host material. The mixture was combined with a ternary mixture of dye RPD-10 to form the light-emitting layer. The mass percentage of compounds represented by formula (I) and formula (II) ranged from 10% to 150%, and the mass percentage of dye in the entire light-emitting layer was 5%.

[0139] The process continued by preparing 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 electrode as a cathode. The total evaporation rate of all organic layers and LiF was controlled at 0.1 nm / s, and the evaporation rate of the metal electrode was controlled at 1 nm / s.

[0140] Examples 1-1 to 1-10 and Comparative Examples 1-1 to 1-4 were prepared according to the preparation method of the first group of organic electroluminescent devices described above. In the examples, the light-emitting host material was composed of a compound represented by formula (I) as the first host and a compound represented by formula (II) as the second host. The specific compound numbers and their mixing ratios are detailed in Table 1. The specific structure of the prior art compound D-N1 used in Comparative Example 1-1 is shown below.

[0141]

[0142] Performance testing

[0143] At the same brightness of 3000 cd / m 2 The efficiency of the organic electroluminescent devices prepared in the examples and comparative examples was measured. Lifetime testing was conducted under constant current, recording the efficiency of each device from an initial luminance of 10000 cd / m². 2 Attenuation to 9700 cd / m 2 The time taken.

[0144] The efficiency and lifetime data of the devices in Table 1 are relative values ​​compared with the experimental data of Comparative Example 1-1.

[0145] Table 1:

[0146] Example First subject Second subject First subject: Second subject efficiency life Comparative Example 1-1 P102 D-N1 1:1 1 1 Comparative Examples 1-2 / N6 / 0.63 0.17 Comparative Examples 1-3 / N9 / 0.59 0.21 Comparative Examples 1-4 / N92 / 0.53 0.14 Example 1-1 P102 N6 1:1 1.03 1.52 Examples 1-2 P102 N9 1:1 1.01 1.41 Examples 1-3 P102 N27 1:1 1.17 1.01 Examples 1-4 P102 N29 1:1 1.11 1.02 Examples 1-5 P102 N41 1:1 1.01 1.33 Examples 1-6 P102 N62 1:1 1.05 1.16 Examples 1-7 P102 N83 1:1 1.15 1.04 Examples 1-8 P102 N92 1:1 1.04 1.13 Examples 1-9 P102 N102 1:1 1.02 1.37 Examples 1-10 P102 N171 1:1 1.08 1.09

[0147] The method for preparing the second group of organic electroluminescent devices of the present invention is as follows:

[0148] 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.

[0149] The glass substrate with the anode was placed in a vacuum chamber and evacuated to a vacuum level of <1×10⁻⁶. -5 Pa, on the above-mentioned anodic layer 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 compound HT-4 as a hole transport layer, and a 60 nm compound HT52 as an electron blocking layer.

[0150] A light-emitting layer with a thickness in the range of 10-60 nm was prepared. A mixture of compounds represented by formula (I) as the first host and compounds represented by formula (II) as the second host was used as a dual-light-emitting host material. The mixture was combined with a ternary mixture of dye RPD-10 to form the light-emitting layer. The mass percentage of compounds represented by formula (I) and formula (II) ranged from 10% to 150%, and the mass percentage of dye in the entire light-emitting layer was 5%.

[0151] The process continued by preparing a 25 nm ET-61: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 electrode as a cathode. The total evaporation rate of all organic layers and LiF was controlled at 0.1 nm / s, and the evaporation rate of the metal electrode was controlled at 1 nm / s.

[0152] Examples 2-1 to 9-4 and Comparative Examples 2-1 to 2-2 were prepared according to the preparation method of the second group of organic electroluminescent devices described above. In the examples, the light-emitting host material was composed of a compound represented by formula (I) as the first host and a compound represented by formula (II) as the second host. The specific compound numbers and their mixing ratios are detailed in Table 2.

[0153] Performance testing

[0154] At the same brightness of 3000 cd / m 2 The efficiency of the organic electroluminescent devices prepared in the examples and comparative examples was measured. Lifetime testing was conducted under constant current, recording the efficiency of each device from an initial luminance of 10000 cd / m². 2 Attenuation to 9700 cd / m 2 The time taken.

[0155] The efficiency and lifetime data of the devices in Table 2 are relative values ​​compared with the experimental data of Comparative Example 2-1.

[0156] Table 2:

[0157] Example number First subject Second subject First subject: Second subject efficiency life Comparative Example 2-1 / N125 / 1 1 Comparative Example 2-2 P55 / / 0.31 3.15 Example 2-1 P1 N1 1:1 2.47 4.69 Example 2-1A P1 N1 1.5:1 2.53 4.75 Example 2-2 P1 N122 1:1 2.16 4.12 Example 2-3 P1 N125 1:1 2.21 3.83 Examples 2-4 P1 N165 1:1 2.05 3.96 Example 3-1 P18 N1 1:1 2.51 4.45 Example 3-1A P18 N1 1.5:1 2.57 4.64 Example 3-2 P18 N122 1:1 2.30 4.03 Example 3-3 P18 N125 1:1 2.32 4.01 Examples 3-4 P18 N165 1:1 2.18 4.26 Example 4-1 P26 N1 1:1 2.42 4.38 Example 4-2 P26 N122 1:1 2.23 4.23 Example 4-3 P26 N125 1:1 2.31 4.11 Example 4-4 P26 N165 1:1 2.19 4.16 Example 5-1 P35 N1 1:1 2.39 4.27 Example 5-2 P35 N122 1:1 2.26 4.15 Example 5-3 P35 N125 1:1 2.15 4.33 Example 5-4 P35 N165 1:1 2.09 4.05 Example 6-1 P55 N1 1:1 2.58 4.66 Example 6-1A P55 N1 1.5:1 2.62 4.78 Example 6-1B P55 N1 1:1.5 2.66 4.31 Example 6-2 P55 N122 1:1 2.27 4.18 Example 6-3 P55 N125 1:1 2.32 4.03 Example 6-4 P55 N165 1:1 2.10 4.12 Example 7-1 P68 N1 1:1 2.39 4.29 Example 7-2 P68 N122 1:1 2.07 4.01 Example 7-3 P68 N125 1:1 2.15 4.13 Example 7-4 P68 N165 1:1 2.11 3.97 Example 8-1 P76 N1 1:1 2.55 4.39 Example 8-2 P76 N122 1:1 2.21 4.14 Example 8-3 P76 N125 1:1 2.26 4.22 Example 8-4 P76 N165 1:1 2.17 4.16 Example 9-1 P85 N1 1:1 2.51 4.29 Example 9-2 P85 N122 1:1 2.13 4.03 Example 9-3 P85 N125 1:1 2.16 4.23 Example 9-4 P85 N165 1:1 2.08 4.14

[0158] As shown in Tables 1 and 2, the mixture composed of the compound represented by formula (I) and the compound represented by formula (II) of this invention, used as a dual-emissivity host material in organic electroluminescent devices, can effectively improve the luminous efficiency and lifespan of the device. This is presumably because when the compound represented by formula (II) is used alone, the injection and transport of holes are poor, resulting in an imbalance in carrier transport. The luminescent recombination center is close to the electron blocking layer (EBL), causing poor device lifespan and low efficiency when used alone. After introducing the compound represented by formula (I) of this invention, due to its excellent hole transport capability, the carrier balance is achieved, and the luminescent recombination center is far from the EBL layer, significantly improving both lifespan and efficiency. Similarly, when the compound represented by formula (I) is used alone, the injection and transport of electrons are poor, resulting in an imbalance in carrier transport. The luminescent recombination center is close to the hole blocking layer (HBL), also causing poor device lifespan and low efficiency.

[0159] The applicant declares that the detailed method of the present invention is illustrated by the above embodiments, but the present invention is not limited to the above detailed method, that is, it does not mean that the present invention must rely on the above detailed method to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the 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. A compositional material for an organic electroluminescent device, said compositional material being used as a light-emitting layer in the organic electroluminescent device, said compositional material comprising a compound represented by formula (I) and a compound represented by formula (II): In formula (Ⅰ), L1 and L2 are each independently selected from one of single bond, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl, and L3 is selected from one of substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl. Ar1 and Ar2 are independently selected from one of substituted or unsubstituted C6-C30 aryl groups and substituted or unsubstituted C3-C30 heteroaryl groups, respectively, and Ar3 is selected from a substituted or unsubstituted heteroaryl group containing a carbazole group. When Ar1, Ar2, Ar3, L1, L2, and L3 have substituent groups, the substituent groups are selected from one or a combination of two of the following: deuterium, halogen, cyano, C1-C30 chain alkyl, C1-C30 alkoxy, C3-C20 cycloalkyl, C3-C20 heterocycloalkyl, C6-C60 aryl, and C3-C60 heteroaryl. In formula (II): Ar4 and Ar5 are each independently selected from one of the substituted or unsubstituted C6-C30 aryl groups or the substituted or unsubstituted C3-C30 heteroaryl groups; L is selected from one of single bond, C6-C30 aryl, and C3-C30 heteroaryl; R1 and R2 are each independently selected from one of C1-C20 chain alkyl groups and C6-C30 aryl groups; R1 and R2 may or may not be connected. R3 and R4 are each independently selected from hydrogen; When Ar4 and Ar5 have substituent groups, the substituent groups are selected from deuterium, halogen, cyano, C1-C30 chain alkyl, C6-C60 aryl, and C3-C60 heteroaryl.

2. The composition material according to claim 1, characterized in that, In formula (I), Ar3 is selected from one of the following groups, either substituted or unsubstituted: Wherein, R is selected from one or a combination of two of the following: C1-C20 chain alkyl, C3-C20 cycloalkyl, C6-C30 aryl, and C3-C30 heteroaryl; When Ar3 has a substituent group, the substituent group is selected from one or a combination of two of the following: chain alkyl groups of C1 to C30, cycloalkyl groups of C3 to C20, aryl groups of C6 to C60, and heteroaryl groups of C3 to C60.

3. The composition material according to claim 1 or 2, characterized in that, In the formula (Ⅰ): L1 and L2 are each independently selected from single bonds, and L3 is selected from phenyl, biphenyl, terphenyl, naphthyl, dibenzofuranyl or dibenzothiophene.

4. The composition material according to claim 1 or 2, characterized in that, In formula (Ⅰ), L3 is selected from phenyl.

5. The composition material according to claim 1, characterized in that, The compound represented by formula (Ⅰ) has any one of the following compounds: 。 6. The composition material according to claim 1, characterized in that, The compound represented by formula (II) is shown in formula (II-1): ； R1 and R2 are each independently selected from methyl, phenyl, or spirofluorenyl; R1 and R2 may or may not be connected; R3 and R4 are each independently selected from hydrogen. And / or, the L is selected from one of single bond, C6-C30 aryl, and C3-C30 heteroaryl; And / or, each of the Ar4 and Ar5 is independently selected from the following groups, substituted or unsubstituted: phenyl, naphthyl, anthracene, phenanthrene, biphenyl, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, spirofluorenyl, benzo[fluorenyl], benzo[furanyl], benzo[thiophene], dibenzo[furanyl], pyridyl, or dibenzo[thiophene].

7. The composition material according to claim 6, characterized in that, L is selected from phenyl, naphthyl, pyridyl, 2-phenylpyridyl or isoquinolinyl.

8. The composition material according to claim 1, characterized in that, The compound represented by formula (II) has any one of the following compounds: 。 9. An organic electroluminescent device, the organic electroluminescent device comprising an anode layer, a cathode layer, and an organic layer disposed between the anode layer and the cathode layer, characterized in that, The organic layer includes a light-emitting layer, which comprises a composition material formed by the compound represented by formula (I) and the compound represented by formula (II) as described in claim 1.

10. The organic electroluminescent device according to claim 9, wherein the light-emitting layer comprises a compositional material formed by any one of the compounds of claim 5 and any one of the compounds of claim 8.

11. The organic electroluminescent device according to claim 9, wherein the mass percentage of the compound represented by formula (I) to the compound represented by formula (II) in the composition material is 10%-200%.

12. The organic electroluminescent device according to claim 9, wherein the mass percentage of the compound represented by formula (I) to the compound represented by formula (II) is 50%-150%.

13. The organic electroluminescent device according to claim 10, wherein the mass percentage of any compound selected from claim 5 and any compound selected from claim 8 in the composition material is 10%-200%.

14. The organic electroluminescent device according to claim 10, wherein the mass percentage of any compound selected from claim 5 and any compound selected from claim 8 is 50%-150%.

15. The organic electroluminescent device according to any one of claims 9-14, characterized in that, The organic layer further includes one or more of a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer; The thickness of the light-emitting layer is 10-60 nm.

16. The organic electroluminescent device according to claim 15, characterized in that, The thickness of the light-emitting layer is 20-50 nm.

17. The organic electroluminescent device according to claim 15, characterized in that, The thickness of the light-emitting layer is 40 nm.

18. A display device, characterized in that, The display device includes an organic electroluminescent device as described in any one of claims 9-17.

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