Organic electroluminescent device and display device

Abstract

The invention provides an organic light-emitting device and a display device. The organic light-emitting device comprises a substrate, an anode, an organic light-emitting layer and a cathode which are sequentially stacked, the organic light-emitting layer comprises a host material, an object light-emitting material and an exciton utilization agent, the host material comprises a hole-type host material and an electron-type host material, and the object light-emitting material comprises a hole-type host material and an electron-type host material. The minimum values of bond dissociation energies of the electronic host material and the exciton utilization agent in an anionic state, an electrically neutral state and a cationic state are respectively and independently greater than or equal to 2.6 eV, the HOMO energy level of the object luminescent material is calculated as H1, the HOMO energy level of the exciton utilization agent is calculated as H2, and H1 and H2 meet the relational expression that H2-H1 is greater than or equal to 0eV and less than or equal to 0.5 eV. The minimum value of the bond dissociation energy of the three materials and the HOMO energy level difference of the two materials are limited in the range, so that the utilization rate of triplet excitons of the blue light-emitting material can be improved, and the light-emitting efficiency and the working life of an OLED device can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of display devices, and in particular to an organic electroluminescent device and a display device. Background Art

[0002] Under electrical excitation, according to the law of spin statistics, the recombination of electrons and holes will produce 25% singlet excitons (S1) and 75% triplet excitons (T1), and different luminescent materials have different exciton (including S1 and T1) utilization rates in devices. For traditional fluorescent materials, triplet excitons cannot emit light through radiative transitions due to spin prohibition and can only dissipate through non-radiative transitions, resulting in an exciton utilization rate of only 25%.

[0003] In order to utilize 75% of T1 for luminescence, Ma Yuguang, Forrest and others successively proposed to accelerate the intersystem crossing (ISC) process from S1 to T1 through the spin-orbit coupling effect of heavy metal atoms, while allowing the originally spin-forbidden radiative transition process from T1 to S0 to occur, thereby realizing phosphorescence emission. Theoretically, the exciton utilization rate can reach 100%.

[0004] Red and green phosphorescent materials have been mass-produced in commercial OLED display panels, but blue phosphorescent materials still have problems such as low color purity and poor stability. Considering the working life of the display, blue fluorescent materials with low exciton utilization are still commonly used in current commercial OLED displays. The luminous efficiency of blue fluorescent materials is low, resulting in a high proportion of power consumption in the blue part of the OLED screen, which may even reach more than half of the total power consumption.

[0005] In recent years, thermally activated delayed fluorescent materials have attracted widespread attention from the industry and scientific research institutions. The T1 and S1 energy levels of thermally activated delayed fluorescent materials are similar (the energy level difference between the singlet and triplet states is defined as ΔE ST , ΔE ST =S1-T1), T1 can absorb the heat in the environment to overcome ΔE ST The energy barrier is converted to S1 (i.e., the reverse intersystem crossing process), achieving efficient utilization of T1. Since the luminescence of TADF materials comes from the charge transfer excited state radiative transition, the spectrum of TADF materials is relatively wide, usually with a half-maximum width (FWHM) of 60 to 100 nm, which limits its application in the display field with high requirements for color purity.

[0006] On this basis, researching and developing a blue light organic electroluminescent device with high efficiency, narrow emission spectrum and long working life is of great significance for reducing the power consumption of OLED display devices. Summary of the invention

[0007] The main purpose of the present invention is to provide an organic light-emitting device and a display device to solve the problem in the prior art that the utilization rate of triplet excitons of blue light-emitting materials is low, resulting in low OLED luminous efficiency and high power consumption of OLED display devices.

[0008] In order to achieve the above-mentioned purpose, the present invention provides an organic electroluminescent device on one hand, which includes a substrate, an anode, an organic light-emitting layer and a cathode which are stacked in sequence, wherein the organic light-emitting layer includes a host material, a guest light-emitting material and an exciton utilization agent, the host material includes a hole-type host material and an electron-type host material, the minimum values ​​of the bond dissociation energies of the electron-type host material and the exciton utilization agent in the anionic state, the electrically neutral state and the cationic state are independently ≥2.6eV, the HOMO energy level of the guest light-emitting material is calculated as H1, the HOMO energy level of the exciton utilization agent is calculated as H2, and H1 and H2 satisfy the relationship: 0eV≤H2-H1≤0.5eV.

[0009] In order to achieve the above-mentioned purpose, another aspect of the present invention further provides a display device, which includes the above-mentioned organic electroluminescent device provided in the present application, and the display device is selected from a tablet mobile phone, a wearable display device, a tablet computer, a laptop computer, a medical display device, a foldable display device, a vehicle-mounted display device, a virtual reality or augmented reality display device.

[0010] By applying the technical solution of the present invention, compared with other ranges, the minimum value of the bond dissociation energy of the above three materials in the organic light-emitting layer is limited to the above specific range, which can enhance the stability of the molecules in the anionic state, the electrically neutral state and the cationic state, and can effectively inhibit the degradation pathways of each material in the triplet-triplet annihilation and triplet-polaron annihilation processes, thereby improving the stability of each material during the operation of the organic electroluminescent device and achieving a longer device service life.

[0011] Compared with other ranges, limiting the HOMO energy level difference (H2-H1) between the exciton utilization agent and the guest luminescent material within the above-mentioned specific range can effectively inhibit the physical process of the guest luminescent material becoming a hole potential well, and reduce the chances of triplet-triplet annihilation and triplet-polaron annihilation of the excitons on the guest luminescent material, thereby improving the utilization rate of triplet excitons in the blue luminescent material, and further improving the luminous efficiency and service life of the OLED device. Applying it to OLED display devices can significantly reduce power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0013] Figure 1 A schematic diagram of the stacked structure of an OLED device in a preferred embodiment is shown;

[0014] Figure 2 A schematic diagram of energy transfer in a preferred embodiment is shown;

[0015] Figure 3 A schematic diagram of the stacked structure of an OLED device in a preferred embodiment is shown;

[0016] Figure 4 A schematic diagram of the stacked structure of an OLED device in another preferred embodiment is shown;

[0017] Figure 5 A schematic diagram of the stacked structure of an OLED device in another preferred embodiment is shown.

[0018] The above drawings include the following reference numerals:

[0019] 10. Substrate; 20. Anode; 30. Organic light-emitting layer; 40. Cathode; 50. Hole transport layer; 60. Electron transport layer; 70. Hole injection layer; 80. Electron injection layer; 90. Optical cover layer. DETAILED DESCRIPTION

[0020] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0021] As described in the background art, the existing blue light-emitting materials have low utilization rate of triplet excitons, resulting in low OLED luminescence efficiency and high power consumption of OLED display devices. In order to solve the above technical problems, the present application provides an organic electroluminescent device, such as Figure 1 As shown, the organic electroluminescent device includes a substrate 10, an anode 20, an organic light-emitting layer 30 and a cathode 40 which are stacked in sequence, wherein the organic light-emitting layer 30 includes a host material, a guest light-emitting material and an exciton utilization agent, the host material includes a hole-type host material and an electronic host material, the minimum values ​​of the bond dissociation energies of the electronic host material and the exciton utilization agent in the anionic state, the electrically neutral state and the cationic state are independently ≥2.6eV, the HOMO energy level of the guest light-emitting material is calculated as H1, the HOMO energy level of the exciton utilization agent is calculated as H2, and H1 and H2 satisfy the relationship: 0eV≤H2-H1≤0.5eV.

[0022] When the organic electroluminescent device is powered on, holes are injected from the anode 20 and electrons are injected from the cathode 40. The injected holes and electrons recombine in the organic light-emitting layer 30 to form excitons. Figure 2As shown, when the exciton utilization agent is a thermally activated delayed fluorescent material, after the host material is excited, an excited state is generated, and the energy is transferred to the exciton utilization agent by means of energy transfer. The triplet excitons of the exciton utilization agent are converted into singlet excitons through the RISC process, and then transferred to the guest luminescent material by means of energy transfer. The singlet excitons of the guest luminescent material are de-excited and returned to the ground state by means of radiation transition, thereby achieving blue light emission. When the exciton utilization agent is a phosphorescent material, the difference between its luminescence mechanism and the above-mentioned method is that: the energy is transferred from the triplet energy level T1 of the phosphorescent material to the singlet energy level of the guest luminescent material by means of the Forster energy transfer process, and the singlet excitons of the guest luminescent material are de-excited and returned to the ground state by means of radiation transition, thereby achieving blue light emission. The organic light-emitting layer 30 containing the above-mentioned materials can fully utilize the singlet and triplet excitons of the host material to sensitize the guest luminescent material by energy transfer, thereby improving the exciton utilization rate.

[0023] Bond dissociation energy (BDE) refers to the energy required to break a chemical bond in a molecule. Bond dissociation energy is one of the important molecular parameters for evaluating material stability. Compared with other ranges, limiting the minimum value of the bond dissociation energy of the above three materials in the organic light-emitting layer 30 to the above specific range can enhance the stability of the molecule in the anionic state, the electrically neutral state and the cationic state, and can effectively inhibit the degradation pathways of each material in the triplet-triplet annihilation and triplet-polaron annihilation processes, thereby improving the stability of each material in the operation process of the organic electroluminescent device and achieving a longer device service life.

[0024] When the HOMO energy level of the guest luminescent material becomes shallower than the HOMO of the exciton utilization agent, the guest luminescent material will become a strong hole potential well, hindering the transmission of holes, thereby increasing the triplet exciton group on the guest luminescent material and increasing the chances of triplet-triplet annihilation and triplet-polaron annihilation of the excitons on the guest luminescent material, thereby reducing the luminous efficiency and shortening the working life of the OLED device. Compared with other ranges, limiting the HOMO energy level difference (H2-H1) between the exciton utilization agent and the guest luminescent material within the above-mentioned specific range can effectively inhibit the physical process of the guest luminescent material becoming a hole potential well, reduce the chances of triplet-triplet annihilation and triplet-polaron annihilation of the excitons on the guest luminescent material, thereby improving the utilization rate of triplet excitons of the blue luminescent material, thereby improving the luminous efficiency and working life of the OLED device, and applying it to an OLED display device can significantly reduce power consumption.

[0025] It should be noted that in the present application, HOMO energy level and LUMO energy level are both well-known concepts in the art, wherein HOMO energy level refers to the highest occupied molecular orbital energy level, and LUMO energy level refers to the lowest unoccupied molecular orbital energy level.

[0026] In a preferred embodiment, H1 and H2 satisfy the relationship: 0.1eV≤H2-H1≤0.4eV. Compared with other ranges, limiting the HOMO energy level difference (H2-H1) between the exciton utilization agent and the guest luminescent material within the above-mentioned specific range is conducive to suppressing the physical process of the guest luminescent material becoming a hole potential well, reducing the chances of triplet-triplet annihilation and triplet-polaron annihilation of the excitons on the guest luminescent material, thereby facilitating the improvement of the utilization rate of triplet excitons in the blue luminescent material, and further facilitating the improvement of the luminescence efficiency of the OLED device. Applying it to the OLED display device is conducive to reducing power consumption.

[0027] In order to further improve the utilization rate of triplet excitons of the blue light-emitting material and further improve the luminous efficiency of the OLED device, preferably, H1 and H2 satisfy the relationship: 0.15 eV≤H2-H1≤0.35 eV.

[0028] In a preferred embodiment, the LUMO energy level of the guest luminescent material is L1, and the LUMO energy level of the exciton utilization agent is L2, and L1 and L2 satisfy the relationship: 0.10eV≤L2-L1≤0.50eV. Compared with other ranges, limiting the LUMO energy level difference (L2-L1) between the exciton utilization agent and the guest luminescent material to the above-mentioned specific range is conducive to suppressing the physical process of the guest luminescent material becoming an electron potential well, reducing the chances of triplet-triplet annihilation and triplet-polaron annihilation of the excitons on the guest luminescent material, thereby facilitating the utilization rate of triplet excitons in the blue luminescent material, and further facilitating the improvement of the luminous efficiency of the OLED device, and applying it to the OLED display device is conducive to reducing power consumption.

[0029] In order to further suppress the physical process of the guest light-emitting material becoming an electron potential well, reduce the chances of triplet-triplet annihilation and triplet-polaron annihilation of the excitons on the guest light-emitting material, thereby further improving the utilization rate of triplet excitons in the blue light-emitting material, and further improving the luminous efficiency of the OLED device, preferably, L1 and L2 satisfy the relationship: 0.20eV≤L2-L1≤0.40eV.

[0030] In order to further suppress the physical process of the guest light-emitting material becoming an electron potential well, reduce the chances of triplet-triplet annihilation and triplet-polaron annihilation of the excitons on the guest light-emitting material, thereby further improving the utilization rate of triplet excitons in the blue light-emitting material, and further improving the luminous efficiency of the OLED device, preferably, L1 and L2 satisfy the relationship: 0.25eV≤L2-L1≤0.35eV.

[0031] In a preferred embodiment, the singlet energy level S1 of the guest luminescent material and the triplet energy level T1 of the exciton utilization agent satisfy the relationship: T1>S1. The triplet energy level T1 of the exciton utilization agent being greater than the singlet energy level S1 of the guest luminescent material is beneficial for converting the triplet excitons of the exciton utilization agent into singlet excitons through the RISC process, and then transferring them to the guest luminescent material through energy transfer, thereby facilitating the improvement of the exciton utilization rate, and further facilitating the improvement of the luminescence efficiency of the OLED device.

[0032] In a preferred embodiment, the HOMO energy level of the hole-type host material is H3, and H1, H2 and H3 satisfy the relationship: H1-H3≥0eV, H2-H3≥0.15eV. The HOMO energy level H1 of the guest luminescent material is greater than the HOMO energy level H3 of the hole-type host material, and the HOMO energy level H2 of the exciton utilization agent is greater than the HOMO energy level H3 of the hole-type host material, which is conducive to better realizing the energy transfer between the host material, the exciton utilization agent and the guest luminescent material, thereby facilitating the improvement of the exciton utilization rate and the luminescence efficiency of the OLED device.

[0033] In order to further improve the utilization rate of excitons and further improve the luminous efficiency of OLED devices, preferably, H1, H2 and H3 satisfy the relationship: H1-H3≥0.05eV, H2-H3≥0.20eV.

[0034] In a preferred embodiment, the bond dissociation energies of the electronic host material and the exciton utilization agent in the anionic state, the electrically neutral state and the cationic state are each independently ≥ 2.8 eV. Compared with other ranges, limiting the minimum value of the bond dissociation energy of the above three materials in the organic light-emitting layer 30 to the above specific range is conducive to enhancing the stability of the molecules in the anionic state, the triplet excited state and the cationic state, and can effectively inhibit the degradation pathways of each material in the triplet-triplet annihilation and triplet-polaron annihilation processes, thereby improving the stability of each material in the operation process of the OLED device and achieving a longer device service life.

[0035] In order to improve the stability of the host material in the anionic state, the electrically neutral state and the cationic state, and further inhibit the degradation pathway of the host material in the triplet-triplet annihilation and triplet-polaron annihilation processes, thereby improving the stability of the host material during the operation of the organic electroluminescent device, preferably, the minimum bond dissociation energy of the electronic host material in the anionic state, the electrically neutral state and the cationic state is ≥3.0 eV.

[0036] In order to improve the stability of the exciton utilization agent in the anionic state, the electrically neutral state and the cationic state, and further inhibit the degradation pathway of the exciton utilization agent in the triplet-triplet annihilation and triplet-polaron annihilation processes, thereby improving the stability of the exciton utilization agent during the operation of the organic electroluminescent device, preferably, the minimum bond dissociation energy of the exciton utilization agent in the anionic state, the electrically neutral state and the cationic state is ≥3.0eV.

[0037] In a preferred embodiment, the hole-type host material includes but is not limited to one or more of the compounds represented by general formula (I) and (II):

[0038]

[0039] Wherein, R includes but is not limited to a link or a phenylene group substituted by at least one deuterium atom, L1 includes but is not limited to a link, a phenylene group, or a phenylene group substituted by at least one deuterium atom, and R1 includes but is not limited to

[0040] Wherein, Y1 includes but is not limited to Si or Ge, m1 represents that the corresponding benzene ring structure is substituted with any integer number of deuterium atoms from 0 to 5, m2 represents that the corresponding benzene ring structure is substituted with any integer number of deuterium atoms from 0 to 4, R2 and R3 each independently include but are not limited to C1-C6 alkyl or C6-C 20 wherein Z includes but is not limited to a connecting bond, O or S; n1 represents that the corresponding benzene ring structure is substituted with any integer number of deuterium atoms from 0 to 3, and n2 and n3 represent that the corresponding benzene ring structure is substituted with any integer number of deuterium atoms from 0 to 4.

[0041] Compared with other types, the use of the above-mentioned hole-type host material having the structure shown in general formulas (I) to (V) is beneficial to improving the triplet energy level and bond dissociation energy of the hole-type host material, thereby helping to improve the luminous efficiency of the OLED device and extend the working life of the OLED device. Applying it to an OLED display device is beneficial to reducing power consumption and improving the stability of the display device.

[0042] In order to further improve the triplet energy level and bond dissociation energy of the hole-type host material, further improve the luminous efficiency of the OLED device and extend the working life of the OLED device, preferably, R includes but is not limited to connecting bonds, n3 represents that the corresponding benzene ring structure is substituted with any integer number of 0 to 4 deuterium atoms, preferably 0 or 4 deuterium atoms.

[0043] In a preferred embodiment, the hole-type host material has one or more of the compounds represented by general formula (Ia), (Ib), (Ic), (Id) and (IIa):

[0044]

[0045]

[0046] Among them, R1 includes but is not limited to R4 includes but is not limited to

[0047]

[0048] Compared with other types, the use of the above-mentioned hole-type host material having the structure shown in general formulas (I) to (V) is beneficial to improving the triplet energy level and bond dissociation energy of the hole-type host material, thereby helping to improve the luminous efficiency of the OLED device and extend the working life of the OLED device. Applying it to an OLED display device is beneficial to reducing power consumption and improving the stability of the display device.

[0049] In a preferred embodiment, L1 includes but is not limited to a connecting bond, a phenylene group, or a phenylene group substituted by 4 deuterium atoms, n1 indicates that the corresponding benzene ring structure is substituted with 0 or 3 deuterium atoms, n2 and n3 each independently indicate that the corresponding benzene ring structure is substituted with 0 or 4 deuterium atoms, and R2 and R3 each independently include but are not limited to a methyl group or a phenyl group. Compared with other types, the hole-type host material with the above structure is conducive to further improving the bond dissociation energy of the hole-type host material, improving the optical stability, electrical stability and chemical stability of the hole-type host material; at the same time, the hole transport ability of the hole-type host material is further regulated, and it is matched with the electronic host material to better regulate the exciton recombination zone of the light-emitting layer, thereby further improving the luminous efficiency and device service life of the OLED device.

[0050] In a preferred embodiment, the hole-type host material includes but is not limited to one or more of compounds HH1 to HH29:

[0051]

[0052]

[0053]

[0054]

[0055] The present application also provides a synthetic route for the compound represented by the above general formula (Ia), which is as follows:

[0056]

[0057] The present application also provides a synthetic route for the compound represented by the above general formula (Ib), which is as follows:

[0058]

[0059] The present application also provides a synthetic route for the compound represented by the above general formula (Ic), which is as follows:

[0060]

[0061] The present application also provides a synthetic route for the compound represented by the above general formula (Id), which is as follows:

[0062]

[0063] The present application also provides a synthetic route for the compound represented by the above general formula (IIa), which is as follows:

[0064]

[0065] In a preferred embodiment, the electronic host material has one or more of the compounds represented by general formula (III) to (XIV):

[0066]

[0067]

[0068] Wherein, R5, R6, and R7 independently include but are not limited to C6 to C 20 aromatic group, C6~C 20 The aromatic group,

[0069] Wherein, Y2 includes but is not limited to Si or Ge, wherein R a Including but not limited to R b and Rc each independently include, but are not limited to, hydrogen, m1 and m5 represent that the corresponding benzene ring structure is substituted with any integer number of deuterium atoms from 0 to 5, m2 and m3 represent that the corresponding benzene ring structure is substituted with any integer number of deuterium atoms from 0 to 3, m4 and m6 represent that the corresponding benzene ring structure is substituted with any integer number of deuterium atoms from 0 to 4; R8, R'8, R"8 and R"'8 each independently include but are not limited to hydrogen, deuterium or And R8, R'8, R"8 and R"'8 are not all the same n4 represents that the corresponding benzene ring structure is substituted with any integer number of deuterium atoms from 0 to 3; R9 includes but is not limited to hydrogen, deuterium or n5 and n6 represent that the corresponding benzene ring structure is substituted with any integer number of deuterium atoms from 0 to 3; R 10 and R 11 Each independently includes but is not limited to Preferably R 12 and R 13 Each independently includes but is not limited to n7 represents that the corresponding benzene ring structure is substituted with any integer number of deuterium atoms from 0 to 4; X1 includes but is not limited to C or N, R 14 and R 15 Each independently includes but is not limited to -CF3, -CN, or R 16 and R 17 Each independently includes but is not limited to -CN or X2 includes but is not limited to O, S or *C=O, R 18 Including but not limited to R 19 Including but not limited to hydrogen, R 20 Including but not limited to R 21 Including but not limited to n8 indicates that the corresponding benzene ring structure is substituted with any integer number of deuterium atoms from 0 to 3; R 22 Including but not limited to R 23 Including but not limited to hydrogen, -CN or deuterium, n9 represents that the corresponding benzene ring structure is substituted with any integer number of deuterium atoms from 0 to 4, n10 represents that the corresponding benzene ring structure is substituted with any integer number of deuterium atoms from 0 to 2; R 24 Including but not limited to n11 indicates that the corresponding benzene ring structure is substituted with any integer number of deuterium atoms from 0 to 2.

[0070] Compared with other types, the use of the above-mentioned types of electronic host materials is beneficial to improving their triplet energy levels and their electron transmission capabilities, which is beneficial to more effectively regulating the exciton recombination zone. At the same time, the above-mentioned electronic host materials have high bond dissociation energy and high stability, which is beneficial to improving the luminous efficiency and service life of OLED devices.

[0071] In a preferred embodiment, the electronic host material includes but is not limited to one or more of compounds EH1 to EH80:

[0072]

[0073]

[0074]

[0075]

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

[0085]

[0086]

[0087]

[0088] In a preferred embodiment, the guest luminescent material includes but is not limited to a fluorescent luminescent material.

[0089] In a preferred embodiment, the guest luminescent material is a multi-resonance organic compound, preferably a boron nitrogen multi-resonance organic compound and / or an indolecarbazole multi-resonance organic compound. Compared with other types, the use of the above-mentioned types of guest luminescent materials is conducive to improving the luminous efficiency of OLED devices, and applying them to OLED display devices is conducive to reducing power consumption.

[0090] The present application also provides a synthetic route for the compound represented by the above general formula (III), which is as follows:

[0091]

[0092] The present application also provides a synthetic route for the compound represented by the above general formula (IV), taking R8 as a substituent, R'8, R"8 and R"'8 as an example to represent hydrogen or deuterium, the synthetic route is as follows:

[0093]

[0094] The present application also provides a synthetic route for the compound represented by the above general formula (V), which is as follows:

[0095]

[0096] The present application also provides a synthetic route for the compound represented by the above general formula (VI), which is as follows:

[0097]

[0098] The present application also provides a synthetic route for the compound represented by the above general formula (VII), which is as follows:

[0099]

[0100] The present application also provides a synthetic route for the compound represented by the above general formula (VIII), which is as follows:

[0101]

[0102] The present application also provides a synthetic route for the compound represented by the above general formula (IX), wherein R 16 Taking cyano as an example, the synthetic route is as follows:

[0103]

[0104] The present application also provides a synthetic route for the compound represented by the above general formula (X), which is as follows:

[0105]

[0106] The present application also provides a synthetic route for the compound represented by the above general formula (XI), wherein R 19 Taking the phosphine oxygen-containing group as an example, the synthetic route is as follows:

[0107]

[0108] The present application also provides a synthetic route for the compound represented by the above general formula (XII), wherein R 20 Taking the phosphine oxygen-containing group as an example, R 21 When it is a carbazole group, the synthetic route is as follows:

[0109]

[0110] The present application also provides a synthetic route for the compound represented by the above general formula (XIII), which is as follows:

[0111]

[0112] The present application also provides a synthetic route for the compound represented by the above general formula (XIV), which is as follows:

[0113]

[0114] In a preferred embodiment, the guest luminescent material includes but is not limited to one or more of the compounds represented by general formula (XV):

[0115] Among them, R 25 and R' 25 Including but not limited to R 26 and R' 26 Including but not limited to Where R 28 and R 29 Each independently includes but is not limited to deuterium or R 27 including but not limited to hydrogen or

[0116] Compared with other types, the use of the above-mentioned types of guest luminescent materials is conducive to improving the luminous efficiency of OLED devices, and applying them to OLED display devices is conducive to reducing power consumption.

[0117] In order to further improve the luminous efficiency of the OLED device, preferably, R 26 and R' 26 Including but not limited to

[0118] In a preferred embodiment, the guest luminescent material includes but is not limited to one or more of Compound E1 to Compound E9:

[0119]

[0120]

[0121]

[0122] Compared with other types, the use of the above-mentioned types of guest luminescent materials is conducive to improving the luminous efficiency of OLED devices, and applying them to OLED display devices is conducive to reducing power consumption.

[0123] The present application also provides a synthetic route for the compound represented by the above general formula (XV), which is as follows:

[0124]

[0125] In a preferred embodiment, the exciton utilization agent includes but is not limited to a metal complex and / or a thermally activated delayed fluorescent material (TADF). Compared with other types, the use of the above-mentioned types of exciton utilization agents is conducive to better exerting its sensitization effect, and is conducive to improving the exciton utilization rate, thereby helping to improve the luminous efficiency of the OLED device, and also helping to improve the color purity of the blue light.

[0126] In order to further improve the exciton utilization rate, and further improve the luminous efficiency of the OLED device and the color purity of the blue light, preferably, the exciton utilization agent includes but is not limited to iridium organic complexes and / or platinum organic complexes.

[0127] In a preferred embodiment, the exciton utilization agent includes but is not limited to one or more of the compounds shown in formula (XVI) and (XVII):

[0128]

[0129] Among them, in the general formula (XVI), W 1 , W 2 and W 3 Each independently includes but is not limited to C or N, W 1 When N is R 31 Empty, W 2 When N is R 33 Empty, W 3 When N is R 34 Empty; R 30 and R' 30 Each independently includes but is not limited to deuterium, hydrogen, C6~C 20 aromatic group, C6~C 20aromatic group, C1~C 10 of an alkyl group, or R 31 Including but not limited to hydrogen, cyano,

[0130] Wherein, n12 and n14 represent that the corresponding benzene ring structure is substituted with any integer number of deuterium atoms from 0 to 5, preferably 0 or 5; n13, n'13, n15 and n16 represent that the corresponding benzene ring structure is substituted with any integer number of deuterium atoms from 0 to 3, preferably 0 or 3; R 39 and R' 39 Each independently includes but is not limited to C1~C 10 Alkyl, or C1-C 10 alkyl, preferably deuterated methyl or methyl; R 40 and R' 40 Each independently includes but is not limited to hydrogen or deuterium; R 41 and R' 41 Including but not limited to C6~C 20 aromatic group, C6~C 20 Aryl, C1~C 10 Alkyl, or C1-C 10 alkyl, preferably phenyl, deuterated phenyl, methyl, deuterated methyl or deuterated tert-butyl; R 32 and R' 32 Each independently includes but is not limited to hydrogen, deuterium, cyano, C1-C 10 Alkyl, C1~C 10 Alkyl, C6~C 20 aromatic group, C6~C 20 C6~C 20 Aryl, C1~C 10 Alkyl-substituted phenyl,

[0131]

[0132]

[0133] R 33 and R 34 Including but not limited to hydrogen, cyano, C6~C 20 C6~C 20 The aromatic group,

[0134] Wherein, n17 represents that the corresponding benzene ring is substituted with any integer number of deuterium atoms from 0 to 3, n18 represents that the corresponding benzene ring is substituted with any integer number of deuterium atoms from 0 to 4, n19 represents that the corresponding benzene ring is substituted with any integer number of deuterium atoms from 0 to 5, R 42 and R' 42 Each independently includes but is not limited to C6~C 20 aromatic group, C6~C 20 Aryl, C1~C 10 Alkyl, or C1-C 10 The alkyl group, R 42 and R' 42 Preferably, it is phenyl, deuterated phenyl, methyl, deuterated methyl or deuterated tert-butyl; R 35 Including but not limited to In the general formula (XVII), R 36 Including but not limited to *CD3, R 37 Including but not limited to n20 represents that the corresponding benzene ring is substituted with any integer of 0 to 4 deuterium atoms, preferably 0 or 4.

[0135] The use of the above-mentioned types of exciton utilization agents is conducive to better exerting their sensitization effect, and is conducive to improving the exciton utilization rate, thereby helping to improve the luminous efficiency of OLED devices and also helping to improve the color purity of blue light.

[0136] In order to further better exert the sensitization effect of the exciton utilization agent, improve the exciton utilization rate, and improve the luminous efficiency of the OLED device and the color purity of the blue light, preferably, R 30 and R' 30 Each independently includes but is not limited to a deuterium atom, a hydrogen atom, a phenyl group, *CD3, deuterated tert-butyl, R 31 Including but not limited to hydrogen atoms, cyano groups,

[0137]

[0138]

[0139]

[0140] R 32 and R' 32Each independently includes, but is not limited to, a hydrogen atom, a deuterium atom, a cyano group, a methyl group, a deuterated methyl group, a phenyl group, a deuterated phenyl group, a cyano-substituted phenyl group, a tert-butyl-substituted phenyl group,

[0141] R 33 and R 34 Including but not limited to hydrogen, cyano, phenyl, cyano substituted phenyl,

[0142]

[0143] In a preferred embodiment, the exciton utilization agent includes but is not limited to one or more of Compound X1 to Compound X90:

[0144]

[0145]

[0146]

[0147]

[0148]

[0149]

[0150]

[0151]

[0152]

[0153]

[0154]

[0155]

[0156]

[0157]

[0158]

[0159]

[0160]

[0161]

[0162]

[0163]

[0164]

[0165] The use of the above-mentioned types of exciton utilization agents is conducive to better exerting their sensitization effect, and is conducive to improving the exciton utilization rate, thereby helping to improve the luminous efficiency of OLED devices and also helping to improve the color purity of blue light.

[0166] The present application also provides a synthetic route for the compound represented by the above general formula (XVI), which is as follows:

[0167]

[0168] The compound represented by the general formula (XVII) in the present application can be synthesized with reference to the following literature: Sun J, Ahn H, Kang S, et al. Exceptionally Stable Blue Phosphorescent Organic Light-Emitting Diodes [J]. Nature Photonics, 2022, 16(3): 212-218.

[0169] In a preferred embodiment, in the first light-emitting functional layer composed of an exciton utilization agent and a host material, the doping concentration of the exciton utilization agent is 1 to 30 wt %, and the maximum luminous intensity of the corresponding electroluminescent spectrum is recorded as E1, and the wavelength on the short wavelength side corresponding to the luminous intensity of 60% E1 is recorded as λ EL The maximum luminous intensity of the corresponding photoluminescence spectrum is E1', and the short wavelength side corresponding to the luminous intensity of 60% E1' is λ PL In the second light-emitting functional layer composed of the host material and the guest light-emitting material, the doping concentration of the guest light-emitting material is 0.1 to 3 wt %, and the maximum light-emitting intensity E2 of the corresponding electroluminescent spectrum is 60% of the wavelength on the short wavelength side corresponding to E2 is λ EL ', the maximum luminous intensity of the corresponding photoluminescence spectrum is E2', and the wavelength on the short wavelength side corresponding to the luminous intensity of 60% E2' is λ EL '; where λ EL and λ EL 'Satisfies the following relationship: EL ≤λ EL ',λ PL and λ PL 'Satisfies the following relationship: PL ≤λPL '.

[0170] The first light-emitting functional layer composed of an exciton utilization agent and a host material with a specific doping concentration has the above-mentioned light-emitting spectrum characteristics, and the second light-emitting functional layer composed of a host material and a guest light-emitting material with a specific doping concentration has the above-mentioned light-emitting spectrum characteristics, and λ is limited EL <λ EL ' and PL <λ PL 'And applying the host material, guest luminescent material and exciton utilization agent that meet the above conditions to the organic light-emitting layer 30 is beneficial to improving the utilization rate of triplet excitons, thereby improving the luminous efficiency of the OLED device.

[0171] In a preferred embodiment, Figure 3 As shown, at least one hole transport layer 50 is further provided between the anode 20 and the organic light emitting layer 30, and at least one electron transport layer 60 is further provided between the cathode 40 and the organic light emitting layer 30. The organic electroluminescent device comprises a substrate 10, an anode 20, a hole transport layer 50, an organic light emitting layer 30, an electron transport layer 60 and a cathode 40 which are stacked in sequence. The OLED device having the above-mentioned stacked structure has high transmission efficiency of holes and electrons, which is conducive to improving the luminous efficiency.

[0172] In a preferred embodiment, the material of the hole transport layer 50 includes, but is not limited to, one or more of the group consisting of aromatic amine derivatives, carbazole derivatives, and spirocyclic compounds. Compared with other types, the use of the above-mentioned types of materials for the hole transport layer 50 is conducive to improving the hole transport efficiency, thereby helping to improve the luminous efficiency of the OLED device.

[0173] In a preferred embodiment, the material of the electron transport layer 60 includes but is not limited to one or more of the group consisting of azine compounds, benzimidazole compounds, phenanthroline compounds, polycyclic compounds, spirofluorene compounds and phosphine oxide compounds. Preferably, azine compounds include pyridine compounds, pyrimidine compounds, triazine compounds and pyridazine compounds; polycyclic compounds include anthracene compounds, pyrene compounds, Compared with other types, the use of the above-mentioned types of materials for the electron transport layer 60 is beneficial to improving the electron transport efficiency, thereby improving the luminous efficiency of the OLED device.

[0174] In a preferred embodiment, Figure 4 As shown, a hole injection layer 70 is further provided between the hole transport layer 50 and the anode 20. The provision of the hole injection layer 70 is conducive to further improving the hole injection efficiency, thereby further improving the luminous efficiency of the OLED device.

[0175] In order to further improve the hole injection efficiency and thus further improve the luminous efficiency of the OLED device, preferably, the material of the hole injection layer 70 includes but is not limited to one or more of the group consisting of aromatic amine compounds, carbazole compounds, spirobifluorene compounds and fluorene compounds.

[0176] In a preferred embodiment, Figure 4 As shown, an electron injection layer 80 is further provided between the electron transport layer 60 and the cathode 40. The provision of the electron injection layer 80 is conducive to further improving the electron injection efficiency, thereby further improving the luminous efficiency of the OLED device.

[0177] In order to further improve the electron injection efficiency and thus further improve the luminous efficiency of the OLED device, preferably, the material of the electron injection layer 80 includes but is not limited to one or more of the group consisting of azine compounds, benzimidazole compounds, phenanthroline compounds, polycondensed ring compounds, spirofluorene compounds and phosphine oxide compounds.

[0178] The substrate 10 in the present application can be a glass substrate 10 commonly used in the art, and the glass substrate 10 has a conductive surface. In a preferred embodiment, the substrate 10 includes but is not limited to indium tin oxide (ITO) conductive glass, fluorine-doped SnO2 (FTO) conductive glass, indium gallium zinc oxide (IGZO) conductive glass or indium zinc oxide (IZO) conductive glass.

[0179] In a preferred embodiment, the cathode 40 is a metal electrode, wherein the metal includes but is not limited to one or more of the group consisting of Ag, Mg, Yb, Al, Ca and Au. The cathode 40 of the above type has good conductivity, which is convenient for improving the current efficiency and luminous efficiency of the OLED device.

[0180] In a preferred embodiment, Figure 5 As shown, the organic electroluminescent device further includes an optical cover layer 90, which is disposed on a surface of the cathode 40 away from the substrate 10, and the material of the optical cover layer 90 includes one or more of the compound represented by formula (A) and the compound represented by formula (B):

[0181]

[0182] Wherein, M includes but is not limited to O or S, Q1 includes but is not limited to hydrogen atom or deuterium atom, L a , L b and L c Each independently includes but is not limited to C6~C 20 Ar1 and Ar2 are the same, and Ar1 and Ar2 include but are not limited to any one of the following structures:

[0183]

[0184] The compound represented by formula (I) and the compound represented by formula (II) have a high refractive index in the visible light region and a very low extinction coefficient. Providing an optical covering layer 90 having the above-mentioned compounds on the surface of the cathode 40 away from the substrate 10 is beneficial to improving the light extraction efficiency and the current efficiency of the OLED device. Moreover, the optical covering layer 90 made of the above-mentioned compounds has high stability and excellent durability.

[0185] In order to further improve the light extraction efficiency and the current efficiency of the OLED device, preferably, L a , L b and L c Each independently includes, but is not limited to, phenylene or naphthylene.

[0186] The second aspect of the present application also provides a display device, which includes the above-mentioned organic electroluminescent device provided in the present application, and the display device includes but is not limited to a tablet mobile phone, a wearable display device, a tablet computer, a laptop computer, a medical display device, a foldable display device, a vehicle display device, a virtual reality or augmented reality display device. The above-mentioned OLED device provided in the present application has a high exciton utilization rate and luminous efficiency, and its application in an OLED display device can significantly reduce power consumption.

[0187] The present application is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

[0188] Device Example 1

[0189] A method for preparing an OLED device, comprising:

[0190] (1) Cutting the ITO conductive glass into a size of 50 mm×50 mm×0.7 mm, ultrasonically treating it in isopropyl alcohol and deionized water for 30 min respectively, and then exposing it to ozone for cleaning for 10 min to obtain a substrate 10; wherein the ITO conductive glass includes an indium tin oxide conductive surface, and the thickness of the indium tin oxide conductive surface is 10 nm;

[0191] (2) Placing the above-mentioned substrate 10 in a vacuum deposition device, and co-evaporating a p-type doping material compound 1 and a hole transport material compound 2 on one side of the indium tin oxide conductive surface of the substrate 10 to obtain a hole injection layer 70 with a thickness of 5 nm; wherein the weight ratio of compound 1 to compound 2 is 3:97; the chemical structures of the raw materials used are as follows:

[0192]

[0193] (3) vacuum evaporating a hole transport material compound 3 on the surface of the hole injection layer 70 away from the ITO conductive glass to obtain a first hole transport layer 50 with a thickness of 100 nm; the chemical structure of the raw material used is as follows:

[0194]

[0195] (4) vacuum evaporating a hole transport material compound HH18 on the surface of the first hole transport layer 50 away from the ITO conductive glass to obtain a second hole transport layer 50 with a thickness of 5 nm;

[0196] (5) vacuum evaporating a host material (compound HH18 and compound EH7), an exciton utilization agent (compound X76) and a guest luminescent material (compound E2) on the surface of the second hole transport layer 50 away from the ITO conductive glass to obtain an organic light-emitting layer 30 with a thickness of 30 nm; wherein the weight ratio of compound HH18, compound EH7, compound X85 and compound E2 is 54:25:20:1;

[0197] (6) vacuum evaporating an electron transport material compound EH7 on the surface of the organic light emitting layer 30 away from the ITO conductive glass to obtain an electron transport layer 60 with a thickness of 5 nm;

[0198] (7) Electron injection materials Compound 8 and Compound 9 are vacuum-deposited on the surface of the electron transport layer 60 away from the ITO conductive glass, and the weight ratio of Compound 8 to Compound 9 is 1:1, to obtain an electron injection layer 80 with a thickness of 30 nm; the chemical structures of the raw materials used are as follows:

[0199]

[0200] (8) vacuum evaporating a magnesium-silver electrode on the surface of the electron injection layer 80 away from the ITO conductive glass, with the weight ratio of metal magnesium to metal silver being 1:9, to obtain a cathode 40 with a thickness of 10 nm;

[0201] (9) Compound 6 is vacuum-evaporated on the surface of the cathode 40 away from the ITO conductive glass to obtain an optical cover layer 90 with a thickness of 65 nm. The chemical structure of compound 6 is as follows:

[0202]

[0203] Device Comparison Example 1

[0204] The difference from device example 1 is that the compound EH7 in step (5) and step (6) is replaced by comparative compound 1. The chemical structure of comparative compound 1 is as follows:

[0205] The bond dissociation energy of the anionic state of the comparative compound 1 calculated by B3LYP / 6-31G* was 2.26 eV.

[0206] Device Comparison Example 2

[0207] The difference from device example 1 is that the compound X76 in step (5) is replaced by comparative compound 2, and the chemical structure of comparative compound 2 is as follows:

[0208] The bond dissociation energy of the anionic state of the comparative compound 3 calculated by B3LYP / 6-31G* was 1.29 eV.

[0209] The bond dissociation energy data of the materials of the organic light-emitting layer 30 in the device example 1 and device comparative examples 1 to 4 of the present application in the anionic state are shown in Table 1.

[0210] Table 1

[0211]

[0212] The OLED devices prepared in the device embodiment 1 and the device comparative examples 1 and 2 of the present application were tested for luminous performance. The test results are shown in Table 2. The blue light index and device service life of the device embodiment 1 are 100%, the blue light index is the ratio of the device current efficiency to the CIEy, and the test condition is 10 mA / cm 2 of current density.

[0213] Table 2

[0214]

[0215] Compared with other ranges, limiting the minimum value of the bond dissociation energy of the main material and the exciton utilization agent in the organic light-emitting layer 30 within the above-mentioned specific range can enhance the stability of the molecules in the anionic state, the electrically neutral state and the cationic state, and can effectively inhibit the degradation pathways of each material in the triplet-triplet annihilation and triplet-polaron annihilation processes, thereby improving the stability of each material during the operation of the organic electroluminescent device and achieving a longer device service life.

[0216] It should be noted that, before carrying out the above device embodiment 1, the inventors first carried out an electroluminescence spectrum characteristic test experiment.

[0217] Test Example 1

[0218] A method for preparing an OLED test device, comprising:

[0219] (1) to (4), steps (1) to (4) are respectively the same as those of the device embodiment 1 above;

[0220] (5) Using compound HH18 and compound EH7 as the main materials and compound X88 as the exciton utilization agent, vacuum evaporation is performed on the surface of the second hole transport layer 50 away from the ITO conductive glass to form a first light-emitting functional layer, wherein the weight ratio of compound HH18, compound EH7 and compound X88 is 45:45:10, that is, in the first light-emitting functional layer, the doping concentration of compound X88 is 10wt%;

[0221] (6) to (9), steps (6) to (9) are respectively the same as those in the above-mentioned device embodiment 1.

[0222] The maximum luminous intensity of the electroluminescence spectrum of the above OLED test device was measured by a color spectroradiometer CS-2000A (Konica Minolta, Japan) and recorded as E1. The wavelength on the short wavelength side corresponding to the luminous intensity of 60% E1 was recorded as λ. EL ,λ EL =455nm.

[0223] Test Example 2

[0224] A method for preparing an OLED test device, comprising:

[0225] (1) to (4), steps (1) to (4) are respectively the same as those of the device embodiment 1 above;

[0226] (5) Using compound HH18 and compound EH7 as host materials and compound E2 as guest luminescent material, vacuum evaporation is performed on the surface of the second hole transport layer 50 away from the ITO conductive glass to form a second luminescent functional layer, wherein the weight ratio of compound HH18, compound EH7 and compound E2 is 50:49:1, and the doping concentration of compound E2 is 1 wt%;

[0227] (6) to (9), steps (6) to (9) are respectively the same as those in the above-mentioned device embodiment 1.

[0228] The maximum luminous intensity E2 of the electroluminescence spectrum of the above OLED test device was measured using a color spectroradiometer CS-2000A (Konica Minolta, Japan). The wavelength on the short wavelength side corresponding to the luminous intensity of 60% E2 is λ EL ',λ EL '=455nm.

[0229] Test Comparative Example 1

[0230] A method for preparing an OLED test device, comprising:

[0231] (1) to (4), steps (1) to (4) are respectively the same as those of the device embodiment 1 above;

[0232] (5) Compound HH18 and compound EH7 were used as the host materials, and comparative compound 3 was used to replace the guest light-emitting material in Test Example 1, and a third light-emitting functional layer was formed by vacuum evaporation on the surface of the second hole transport layer 50 away from the ITO conductive glass, wherein the doping concentration of comparative compound 3 was 1 wt %, and the chemical structure of comparative compound 3 was as follows:

[0233]

[0234] (6) to (9), steps (6) to (9) are respectively the same as those in the above-mentioned embodiment 1.

[0235] The maximum luminous intensity E3 of the electroluminescence spectrum of the above OLED test device was measured using a color spectroradiometer CS-2000A (Konica Minolta, Japan). The wavelength on the short wavelength side corresponding to the luminous intensity of 60% E3 is λ EL C ,λ EL C =449nm.

[0236] By comparison, we can see that EL =λ EL ', meets the above range of this application, and λ EL >λ EL C , does not satisfy the above range of the present application, which indicates that there is a higher chance of energy transfer from the exciton utilization agent compound X88 to the guest luminescent material compound E2; on the contrary, the exciton utilization agent compound X88 and the guest luminescent material comparison compound 3 do not satisfy the above relationship, and the chance of energy transfer from the exciton utilization agent X88 to the guest luminescent material comparison compound 3 is even lower.

[0237] Device Example 2

[0238] The difference from device embodiment 1 is that in step (5), the weight ratio of compound HH18, compound EH7, compound X88 and compound E2 is 45:44:10:1.

[0239] Device Comparison Example 3

[0240] The difference from device example 1 is that comparative compound 3 is used to replace compound E2 in step (5), and the weight ratio of compound HH18, compound EH7, compound X88 and comparative compound 3 is 45:44:10:1. The chemical structure of comparative compound 3 is as shown above.

[0241] The OLED devices prepared in the device embodiment 2 and the device comparative example 3 of the present application were tested for luminous performance. The test results are shown in Table 3. The blue light index and device service life of the device embodiment 2 are 100%, the blue light index is the ratio of the device current efficiency to the CIEy, and the test conditions are 10 mA / cm 2 of current density.

[0242] Table 3

[0243]

[0244] Device Comparison Example 4

[0245] The difference from device example 1 is that comparative compound 4 is used to replace compound E2 in step (5), and the weight ratio of compound HH18, compound EH7, compound X88 and comparative compound 4 is 45:44:10:1. The chemical structure of comparative compound 4 is as follows:

[0246]

[0247] The exciton utilization agent and the guest luminescent material used in the above-mentioned device embodiment 2 and device comparison example 4 of the present application were respectively evaporated on the surface of the silicon wafer by evaporation to obtain a test sample with a thickness of 50 nm. The HOMO energy level was tested by AC2 photoelectron energy spectrum. The test data is shown in Table 4.

[0248] Table 4

[0249] Compound HOMO(eV) Compound HH18 -5.46 Compound EH7 -5.91 Compound X88 -5.15 Compound E2 -5.42 Comparative Compound 4 -4.98

[0250] As can be seen from Table 4, the guest luminescent material compound E2 has a deeper HOMO energy level than the exciton utilization compound X88, and the difference between the HOMO energy level (H2) of the exciton utilization compound X88 and the HOMO energy level (H1) of the guest luminescent material compound E2 is 0.27 eV, which satisfies the above relationship of the present application: 0eV≤H2-H1≤0.5eV. However, the comparative compound 4 has a shallower HOMO energy level than the exciton utilization compound X88, and does not satisfy the above relationship.

[0251] The OLED devices prepared in the device embodiment 2 and the device comparative example 4 of the present application were tested for luminous performance. The test results are shown in Table 5. The blue light index and device service life of the device embodiment 2 are 100%, the blue light index is the ratio of the device current efficiency to the CIEy, and the test conditions are 10 mA / cm 2 of current density.

[0252] Table 5

[0253]

[0254] From the data in Table 5, it can be seen that the blue light index of the device comparison example 3 is significantly reduced relative to that of the device embodiment 2, which indicates that a more efficient energy transfer occurs from the exciton utilization compound X88 to the guest luminescent material compound E2, while no efficient energy transfer is formed between the exciton utilization compound X88 and the guest luminescent material comparison compound 3, which is consistent with the data from the electroluminescence spectrum characteristics test experiment.

[0255] From the analysis of Table 4 and Table 5, it can be seen that the comparative compound 4 in the device comparative example 4 has a shallower HOMO energy level than the exciton utilization agent compound X88. When the HOMO energy level of the guest luminescent material becomes shallower than the HOMO of the exciton utilization agent, the guest luminescent material will become a strong hole potential well, hindering the transmission of holes, thereby being able to increase the triplet exciton group on the guest luminescent material, and increasing the chances of triplet-triplet annihilation and triplet-polaron annihilation of the excitons on the guest luminescent material, thereby resulting in a decrease in the luminous efficiency and a shortened working life of the OLED device. The guest light-emitting material compound E2 used in device embodiment 2 has a deeper HOMO energy level than the exciton utilization agent compound X88, and can effectively inhibit the physical process of the guest light-emitting material becoming a hole potential well, and reduce the chances of triplet-triplet annihilation and triplet-polaron annihilation of the excitons on the guest light-emitting material, thereby improving the utilization rate of triplet excitons in the blue light-emitting material, and further improving the luminous efficiency and service life of the OLED device. Applying it to an OLED display device can significantly reduce power consumption.

[0256] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those described herein, for example.

[0257] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises a substrate (10), an anode (20), an organic light-emitting layer (30) and a cathode (40) which are stacked in sequence, wherein the organic light-emitting layer (30) comprises a host material, a guest light-emitting material and an exciton utilization agent, the host material comprises a hole-type host material and an electron-type host material, the minimum values ​​of the bond dissociation energies of the electron-type host material and the exciton utilization agent in anionic state, electrically neutral state and cationic state are independently ≥2.6eV, the HOMO energy level of the guest light-emitting material is H1, the HOMO energy level of the exciton utilization agent is H2, and H1 and H2 satisfy the relationship: 0eV≤H2-H1≤0.5eV.

2. The organic electroluminescent device according to claim 1, characterized in that: The H1 and H2 satisfy the relationship: 0.1eV≤H2-H1≤0.4eV; Preferably, H1 and H2 satisfy the relationship: 0.15eV≤H2-H1≤0.35eV.

3. The organic electroluminescent device according to claim 1, characterized in that: The LUMO energy level of the guest luminescent material is L1, the LUMO energy level of the exciton utilization agent is L2, and L1 and L2 satisfy the relationship: 0.10 eV≤L2-L1≤0.50 eV; Preferably, L1 and L2 satisfy the relationship: 0.20eV≤L2-L1≤0.40eV; Preferably, L1 and L2 satisfy the relationship: 0.25eV≤L2-L1≤0.35eV.

4. The organic electroluminescent device according to claim 1, characterized in that: The singlet energy level S1 of the guest luminescent material and the triplet energy level T1 of the exciton utilization agent satisfy the relationship: T1>S1; Preferably, the HOMO energy level of the hole-type host material is H3, and the H1, H2 and H3 satisfy the relationship: H1-H3≥0eV, H2-H3≥0.15eV; More preferably, H1, H2 and H3 satisfy the relationship: H1-H3≥0.05eV, H2-H3≥0.20eV.

5. The organic electroluminescent device according to claim 1, characterized in that: The bond dissociation energies of the electronic host material and the exciton utilization agent in the anionic state, the electrically neutral state, and the cationic state are each independently ≥ 2.8 eV; Preferably, the bond dissociation energy of the electronic host material in the anionic state, the electrically neutral state and the cationic state is ≥3.0 eV; Preferably, the bond dissociation energy of the exciton utilizing agent in the anionic state, the electrically neutral state and the cationic state is ≥3.0 eV.

6. The organic electroluminescent device according to claim 1, characterized in that: The hole-type host material is selected from one or more compounds represented by general formula (I) and (II): wherein R is selected from a linker or a phenylene group substituted by at least one deuterium atom, L1 is selected from a linker, a phenylene group, or a phenylene group substituted by at least one deuterium atom, R1 is selected from wherein Y1 is selected from Si or Ge, m1 represents that the corresponding benzene ring structure is substituted with any integer of 0 to 5 deuterium atoms, m2 represents that the corresponding benzene ring structure is substituted with any integer of 0 to 4 deuterium atoms, R2 and R3 are each independently selected from C1 to C6 alkyl or C6 to C 20 The aromatic group of , Z is selected from a connecting bond, O or S; n1 represents that the corresponding benzene ring structure is substituted with any integer number of deuterium atoms from 0 to 3, and n2 represents that the corresponding benzene ring structure is substituted with any integer number of deuterium atoms from 0 to 4; Preferably, said R is selected from a connecting bond, n3 represents that the corresponding benzene ring structure is substituted with any integer number of deuterium atoms from 0 to 4, preferably 0 or 4 deuterium atoms; Preferably, the hole-type host material has one or more of the compounds represented by general formula (Ia), (Ib), (Ic), (Id) and (IIa): Wherein R1 is selected from R4 is selected from More preferably, L1 is selected from a linker, a phenylene group, or a phenylene group substituted by 4 deuterium atoms, n1 represents that the corresponding benzene ring structure is substituted by 0 or 3 deuterium atoms, n2 and n3 each independently represent that the corresponding benzene ring structure is substituted by 0 or 4 deuterium atoms, and R2 and R3 each independently represent that the corresponding benzene ring structure is substituted by 0 or 4 deuterium atoms, and R2 and R3 each independently represent that a methyl group or a phenyl group; More preferably, the hole-type host material is selected from one or more of compounds HH1 to HH29: Preferably, the electronic host material has one or more of the compounds represented by general formulae (III) to (XIV): Wherein, R5, R6, and R7 are each independently selected from C6 to C 20 aromatic group, C6~C 20 The aromatic group, Wherein, Y2 is selected from Si or Ge, wherein R a Selected from R b and Rc are each independently selected from hydrogen, The m1 and m5 represent that the corresponding benzene ring structure is substituted with any integer number of deuterium atoms from 0 to 5, m2 and m3 represent that the corresponding benzene ring structure is substituted with any integer number of deuterium atoms from 0 to 3, and m4 and m6 represent that the corresponding benzene ring structure is substituted with any integer number of deuterium atoms from 0 to 4; R8, R'8, R"8 and R"'8 are each independently selected from hydrogen, deuterium or and said R8, said R'8, said R"8 and said R"'8 are not simultaneously n4 indicates that the corresponding benzene ring structure is substituted with any integer number of deuterium atoms from 0 to 3; R9 is selected from hydrogen, deuterium or n5 and n6 represent that the corresponding benzene ring structure is substituted with any integer number of deuterium atoms from 0 to 3; R 10 and R 11 Each independently selected from Preferably R 12 and R 13 Each independently selected from n7 indicates that the corresponding benzene ring structure is substituted with any integer number of deuterium atoms from 0 to 4; X1 is selected from C or N, R 14 and R 15 Each independently selected from -CF3, -CN, or R 16 and R 17 Each independently selected from -CN or X2 is selected from O, S or *C=O, R 18 Selected from R 19 Selected from hydrogen, R 20 Selected from R 21 Selected from n8 indicates that the corresponding benzene ring structure is substituted with any integer number of deuterium atoms from 0 to 3; R 22 Selected from R 23 is selected from hydrogen, -CN or deuterium, n9 represents that the corresponding benzene ring structure is substituted with any integer number of deuterium atoms from 0 to 4, and n10 represents that the corresponding benzene ring structure is substituted with any integer number of deuterium atoms from 0 to 2; R 24 Selected from n11 indicates that the corresponding benzene ring structure is substituted with any integer number of deuterium atoms from 0 to 2; More preferably, the electronic host material is selected from one or more of compounds EH1 to EH80:

7. The organic electroluminescent device according to claim 1, characterized in that: The guest luminescent material is selected from fluorescent luminescent materials; Preferably, the guest light-emitting material is a multi-resonance organic compound, more preferably a boron-nitrogen multi-resonance organic compound and / or an indolecarbazole multi-resonance organic compound.

8. The organic electroluminescent device according to claim 1, characterized in that: The guest luminescent material is selected from one or more compounds represented by general formula (XV): Among them, R 25 and R' 25 Selected from R 26 and R' 26 Selected from Where R 28 and R 29 Each independently selected from deuterium or R 27 Selected from hydrogen or Preferably, the R 26 and the R' 26 Selected from Preferably, the guest luminescent material is selected from one or more of Compound E1 to Compound E9:

9. The organic electroluminescent device according to claim 1, characterized in that: The exciton utilization agent is selected from metal complexes and / or thermally activated delayed fluorescent materials; Preferably, the exciton utilization agent is selected from iridium organic complexes and / or platinum organic complexes.

10. The organic electroluminescent device according to claim 1, characterized in that: The exciton utilization agent is selected from one or more compounds shown in general formula (XVI) and (XVII): Wherein, in the general formula (XVI), W 1 , W 2 and W 3 Each independently selected from C or N, W 1 When N is R 31 Empty, W 2 When N is R 33 Empty, W 3 When N is R 34 is empty; R 30 and R' 30 Each independently selected from deuterium, hydrogen, C6~C 20 aromatic group, C6~C 20 aromatic group, C1~C 10 of an alkyl group, or R 31 Selected from hydrogen, cyano, Wherein, n12 and n14 represent that the corresponding benzene ring structure is substituted with any integer number of deuterium atoms from 0 to 5, preferably 0 or 5; n13, n'13, n15 and n16 represent that the corresponding benzene ring structure is substituted with any integer number of deuterium atoms from 0 to 3, preferably 0 or 3; R 39 and R' 39 Each independently selected from C1 to C 10 Alkyl, or C1-C 10 alkyl, preferably deuterated methyl or methyl; R 40 and R' 40 are each independently selected from hydrogen or deuterium; R 41 and R' 41 Selected from C6~C 20 aromatic group, C6~C 20 Aryl, C1~C 10 Alkyl, or C1-C 10 The alkyl group is preferably phenyl, deuterated phenyl, methyl, deuterated methyl or deuterated tert-butyl; R 32 and R' 32 are independently selected from hydrogen, deuterium, cyano, C1-C 10 Alkyl, C1~C 10 Alkyl, C6~C 20 aromatic group, C6~C 20 C6~C 20 Aryl, C1~C 10 Alkyl-substituted phenyl, R 33 and R 34 Selected from hydrogen, cyano, C6~C 20 C6~C 20 The aromatic group, Wherein, n17 represents that the corresponding benzene ring is substituted with any integer number of deuterium atoms from 0 to 3, n18 represents that the corresponding benzene ring is substituted with any integer number of deuterium atoms from 0 to 4, n19 represents that the corresponding benzene ring is substituted with any integer number of deuterium atoms from 0 to 5, R 42 and R' 42 Each independently selected from C6 to C 20 aromatic group, C6~C 20 Aryl, C1~C 10 Alkyl, or C1-C 10 The alkyl group, R 42 and the R' 42 Preferably, it is phenyl, deuterated phenyl, methyl, deuterated methyl or deuterated tert-butyl; R 35 Selected from In the general formula (XVII), R 36 Selected from *CD3, R 37 Selected from n20 represents that the corresponding benzene ring is substituted with any integer number of deuterium atoms from 0 to 4, preferably 0 or 4; Preferably, the R 30 and the R' 30 are independently selected from a deuterium atom, a hydrogen atom, a phenyl group, *CD3, deuterated tert-butyl, The R 31 Selected from hydrogen atoms, cyano groups, The R 32 and the R' 32 are each independently selected from a hydrogen atom, a deuterium atom, a cyano group, a methyl group, a deuterated methyl group, a phenyl group, a deuterated phenyl group, a phenyl group substituted with a cyano group, a phenyl group substituted with a tert-butyl group, The R 33 and the R 34 is selected from hydrogen, cyano, phenyl, cyano-substituted phenyl, More preferably, the exciton utilization agent is selected from one or more of Compound X1 to Compound X90:

11. The organic electroluminescent device according to any one of claims 1 to 10, characterized in that: In the first light-emitting functional layer composed of the exciton utilization agent and the host material, the doping concentration of the exciton utilization agent is 1 to 30 wt %, the maximum luminous intensity of the corresponding electroluminescent spectrum is recorded as E1, and the wavelength on the short wavelength side corresponding to the luminous intensity of 60% E1 is recorded as λ EL The maximum luminous intensity of the corresponding photoluminescence spectrum is E1', and the short wavelength side corresponding to the luminous intensity of 60% E1' is λ PL In the second light-emitting functional layer composed of the host material and the guest light-emitting material, the doping concentration of the guest light-emitting material is 0.1 to 3 wt %, and the maximum light-emitting intensity E2 of the corresponding electroluminescent spectrum is 60% of the wavelength on the short wavelength side corresponding to E2 is λ EL ', the maximum luminous intensity of the corresponding photoluminescence spectrum is E2', and the wavelength on the short wavelength side corresponding to the luminous intensity of 60% E2' is λ EL '; wherein the λ EL and the λ EL 'Satisfies the following relationship: EL ≤λ EL ', the λ PL and the λ PL 'Satisfies the following relationship: PL ≤λ PL '.

12. The organic electroluminescent device according to any one of claims 1 to 10, characterized in that: At least one hole transport layer (50) is provided between the anode (20) and the organic light-emitting layer (30), and at least one electron transport layer (60) is provided between the cathode (40) and the organic light-emitting layer (30); Preferably, a hole injection layer (70) is further provided between the hole transport layer (50) and the anode (20); Preferably, an electron injection layer (80) is further provided between the electron transport layer (60) and the cathode (40); Preferably, the material of the hole transport layer (50) is selected from one or more of the group consisting of aromatic amine compounds, carbazole compounds, and spirocyclic compounds; Preferably, the material of the electron transport layer (60) is one or more selected from the group consisting of azine compounds, benzimidazole compounds, phenanthroline compounds, polycondensed ring compounds, spirofluorene compounds and phosphine oxide compounds.

13. The organic electroluminescent device according to any one of claims 1 to 10, characterized in that: The organic electroluminescent device further comprises an optical cover layer (90), wherein the optical cover layer (90) is arranged on a surface of the cathode (40) away from the substrate (10), and the material of the optical cover layer (90) comprises one or more of the compound represented by formula (A) and the compound represented by formula (B): Wherein, M is selected from O or S, Q1 is selected from hydrogen atom or deuterium atom, L a , L b and L c Each independently selected from C6 to C 20 Ar1 and Ar2 are the same, and Ar1 and Ar2 are selected from any one of the following structures:

14. The organic electroluminescent device according to claim 13, characterized in that: The L a , the L b and the L c Each is independently selected from phenylene or naphthylene.

15. A display device, characterized in that: The display device comprises the organic electroluminescent device according to claim 1, and the display device is selected from a tablet mobile phone, a wearable display device, a tablet computer, a laptop computer, a medical display device, a foldable display device, a vehicle-mounted display device, a virtual reality or augmented reality display device.

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