Compound, light emitting device, and display device

Abstract

The invention provides a compound, a light-emitting device and a display device. The compound comprises a structural general formula 1 and a structural general formula 2, het in the structural general formula 1 satisfies a structural general formula 3. According to the technical scheme, the efficiency and service life of the display device can be improved, and the voltage of the display device is reduced. # imgabs0 # [general structural formula 3] # imgabs1 #

Description

Technical Field

[0001] The present application relates to the field of display technology, and more specifically, to a compound, a light-emitting device and a display apparatus. Background Art

[0002] Organic light emitting diodes (OLED) have the advantages of being light, thin, self-luminous, low power, no backlight, wide viewing angle and fast response. They have gradually replaced liquid crystal display panels to become a new generation of flat panel displays, and also have great potential in flexible displays. At present, OLED has gradually been applied to high-end display fields such as mobile phones, wearable devices, vehicles and computers.

[0003] Among them, OLED materials have also received more and more attention due to their importance in OLEDs, and have made remarkable progress in recent years. When selecting OLED materials, many factors need to be considered, such as their impact on the voltage, life and efficiency of OLEDs. Therefore, how to select OLED materials to improve the performance of OLEDs is a technical problem that needs to be solved urgently. Summary of the invention

[0004] In view of the above problems, the present application provides a compound, a light-emitting device and a display device, which can improve the efficiency and life of the display device and reduce the voltage of the display device.

[0005] In a first aspect, a compound is provided, comprising structural formula 1 and structural formula 2:

[0006]

[0007] Het in the general structural formula 1 satisfies the general structural formula 3:

[0008] [Structural Formula 3]

[0009]

[0010] Wherein, in the general structural formula 1, the general structural formula 2, and the general structural formula 3: * is the connection point of the general structural formula 1 and the general structural formula 2, and any two adjacent connection points in the general structural formula 1 are connected with the connection point in the general structural formula 2 to obtain a condensed ring; o, i, r, s are independently non-negative integers in the range of 0-4; J is 0 or 1; A is benzene or naphthalene; X is N; Y is at least one of O, S or N(Rb); Q is O, S, C(Ra)(Rb) or N at least one of (Rc); W is a direct bond; h is 0 or 1; Ra and Rb are independently deuterium, tritium, hydrogen, halogen, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C6-C60 heteroaryl, substituted or unsubstituted C1-C50 alkyl, substituted or unsubstituted C1-C50 cycloalkyl, substituted or unsubstituted C1-C50 alkoxy, substituted or unsubstituted C5-C50 aryloxy, substituted or unsubstituted C5-C50 arylthio, substituted or any one of unsubstituted C1-C50 alkoxycarbonyl; Rc, R21, R22 are independently deuterium, tritium, hydrogen, halogen, cyano, nitro, hydroxyl, substituted or unsubstituted C1-C18 alkyl, substituted or unsubstituted C2-C18 alkenyl, substituted or unsubstituted C2-C18 alkynyl, substituted or unsubstituted C3-C18 cycloalkyl, substituted or unsubstituted C1-C18 alkoxy, substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C5-C18 heteroaryl , any one of substituted or unsubstituted C5-C18 heterocyclic groups; L1, L2 and L3 are independently any one of a direct bond, a substituted or unsubstituted C6-C30 aryl group, or a substituted or unsubstituted C2-C30 heteroaryl group; Ar1 ​​and Ar2 are independently any one of a substituted or unsubstituted C6-C30 aryl group, or a substituted or unsubstituted C3-C30 heteroaryl group; Ar3 and Ar4 are independently any one of a direct bond, an alkyl group, a cycloalkyl group, a heterocycloalkyl group, an alkenyl group, or an alkynyl group.

[0011] In combination with the first aspect, in certain implementations of the first aspect, the general structural formula is any one of the following structures:

[0012]

[0013]

[0014] In combination with the first aspect, in certain implementations of the first aspect, the general structural formula 3 is one of the following structures:

[0015]

[0016] In the general structural formula 3-1, the general structural formula 3-2, the general structural formula 3-3 and the general structural formula 3-4: G is a direct bond, any one of O, S, C, and N; E is any one of O, S, and N; a, b, c, d, e, f, g, m, n, and p are non-negative integers in the range of 0-4; R1-R10 are independently deuterium, tritium, hydrogen, halogen, cyano, nitro, hydroxyl, substituted or unsubstituted C1-C18 alkyl, substituted or unsubstituted C2-C18 alkenyl, substituted or unsubstituted C2-C18 alkynyl, substituted or unsubstituted C3-C18 cycloalkyl, substituted or unsubstituted C1-C18 alkoxy, substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C5-C18 heteroaryl, or substituted or unsubstituted C5-C18 heterocyclyl.

[0017] In combination with the first aspect, in certain implementations of the first aspect, at least one of the Ra, the Rb, the Rc, the R21, the R22, and the R1-R10 is deuterium.

[0018] In combination with the first aspect, in certain implementations of the first aspect, the triplet energy level T1 of the compound satisfies: 2.1 eV≤T1≤2.5 eV.

[0019] In combination with the first aspect, in certain implementations of the first aspect, the reorganization energy λ of the compound satisfies: λ≤0.3 eV.

[0020] In combination with the first aspect, in certain implementations of the first aspect, the absolute value of the energy value of the highest occupied molecular orbital of the compound satisfies: 5.0 eV≤|HOMO|≤5.9 eV.

[0021] In combination with the first aspect, in certain implementations of the first aspect, the absolute value of the energy value of the lowest unoccupied molecular orbital of the compound satisfies: 1.8 eV≤|LUMO|≤2.2 eV.

[0022] In a second aspect, a light-emitting device is provided, comprising a first electrode, a light-emitting layer, and a second electrode stacked in sequence; the light-emitting layer comprises a first material, and the first material comprises the compound described in any embodiment of the first aspect.

[0023] According to the second aspect, in certain implementations of the second aspect, the light-emitting layer further includes a second material, and the absolute value difference of the energy values ​​of the highest occupied molecular orbitals of the first material and the second material satisfies: Δ|HOMO|≤0.5 eV.

[0024] In a third aspect, a display device is provided, comprising the compound described in any implementation of the first aspect of the present application, or the light-emitting device described in any implementation of the second aspect of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without paying creative work.

[0026] Figure 1 This is a schematic structural diagram of a light-emitting device according to an embodiment of the present application;

[0027] Figure 2a and Figure 2b This is an electron cloud diagram of the excited state T1 according to one embodiment of the present application. DETAILED DESCRIPTION

[0028] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below in conjunction with the accompanying drawings.

[0029] The "range" disclosed in the present application is defined in the form of a lower limit and an upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a specific range. The range defined in this way includes the endpoint values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a range. For example, if the range of 60-120 and 80-110 is listed for a specific parameter, it is understood that the range of 60-110 and 80-120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4 and 5 are listed, the following ranges can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present application, unless otherwise specified, the numerical range "ab" represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers. For example, the numerical range "0-5" represents that all real numbers between "0-5" have been fully listed herein, and "0-5" is just the abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0030] If not otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0031] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0032] The terms used in the following embodiments are only for the purpose of describing specific embodiments, and are not intended to be used as limitations on the present application. As used in the specification and the appended claims of the present application, the singular expressions "one", "a kind of", "said", "above", "the" and "this" are intended to also include expressions such as "one or more", unless there is a clear contrary indication in the context. It should also be understood that in the following embodiments of the present application, "at least one", "one or more" refer to one, two or more. The term "and / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist; for example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship.

[0033] References to "one embodiment", "some embodiments", "an example" or "some examples" described in this specification mean that a particular feature, structure or characteristic described in conjunction with the example is included in one or more examples of the present application. Thus, the phrases "in one embodiment", "in some other examples", "in some other examples", etc. appearing at different places in this specification do not necessarily all refer to the same example, but mean "one or more but not all examples", unless otherwise specifically emphasized. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized.

[0034] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different description objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0035] The present application embodiments will be described in more detail below with reference to the accompanying drawings. In each of the accompanying drawings, the same elements are represented by similar reference numerals. For the sake of clarity, the various parts in the accompanying drawings are not drawn to scale. In addition, some well-known parts may not be shown in the drawings.

[0036] The OLED device includes an anode layer, a hole injection layer (HIL), a hole transport layer (HTL), an electron blocking layer (EBL), an emitting layer (EML), a hole blocking layer (HBL), an electron transport layer (ETL), an electron injection layer (EIL), and a cathode layer sequentially deposited on a substrate. When the OLED device is working, a voltage is applied to the anode and the cathode, and the holes injected from the anode electrode move to the EML layer via the HTL layer, and the electrons injected from the cathode electrode move to the EML layer via the ETL layer. Holes and electrons recombine in the EML layer to produce excitons. Light is emitted when the excitons drop from the excited state to the ground state. The injection and flow of holes and electrons should be balanced so that the OLED device with the above structure can work normally.

[0037] In OLED devices, the excitons formed by the recombination of electrons and holes are not restricted by the spin law. According to statistical calculations, the ratio of excited singlet state to excited triplet state is 1:3. Fluorescent electroluminescence only utilizes the excited singlet state, that is, only about 25% of the input energy is utilized, and the energy of the excited triplet state, which accounts for 75% of the input energy, is wasted. However, phosphorescent organic light-emitting diode (PHOLED) devices can utilize excited singlet state and excited triplet state at the same time, and use spin-orbit coupling to make 75% of triplet excitons that could not be used originally transition to the ground state, breaking the limitation of OLED devices that the internal quantum efficiency is not higher than 25%. In principle, the internal quantum efficiency of PHOLED can reach 100%. Therefore, phosphorescent organic electroluminescence is considered to be an effective way to improve device efficiency.

[0038] Therefore, the selection of the light-emitting layer material will directly affect the efficiency of exciton formation, and then affect the performance of the device. At present, in the existing red light OLED devices, the light-emitting layer includes a host material and a phosphorescent guest, and the host material can be a single-component material or a multi-component material. When the light-emitting layer includes multi-component materials, that is, hole-type host (RH-P) materials and electron-type host (RH-N) materials, the RH-P material and the RH-N material can form an exciton complex. Under electrical excitation, electrons and holes recombine on the host to form excitons, and the excitons transfer energy from the host to the phosphorescent guest, and then emit light through the radiation transition of the phosphorescent guest.

[0039] However, due to the existence of non-radiative transition processes such as triplet-triplet annihilation and triplet-polaron annihilation in phosphorescent materials, the luminescence efficiency of the film itself is very low. Only when it is doped into the main material can it emit light efficiently. Therefore, the development of the main material is particularly important.

[0040] In view of the above problems, an embodiment of the present application provides a compound that can be used as a host material and mixed with a phosphorescent material for application in an OLED device, thereby improving the efficiency and life of the device and reducing the voltage of the device.

[0041] Unless otherwise specified, the compound is used as the RH-N material in the red light host material. Of course, it may also be other materials, and this application does not make any special restrictions on this.

[0042] Figure 1 FIG. 1 is a schematic diagram of the structure of a light emitting device according to an embodiment of the present application. Figure 1 The light-emitting device 100 includes a substrate 110, a first electrode (ITO) 120, a hole injection layer 131, a hole transport layer 132, an electron blocking layer 133, a light-emitting layer 134, a hole blocking layer 135, an electron transport layer 136, an electron injection layer 137 and a second electrode 140, which are arranged in sequence. The compound described in the embodiment of the present application is applied in the light-emitting layer 134.

[0043] The first aspect of the present application provides a compound, including structural formula 1 and structural formula 2:

[0044]

[0045] Het in the general structural formula 1 satisfies the general structural formula 3:

[0046] [Structural Formula 3]

[0047]

[0048] Wherein, in the general structural formula 1, the general structural formula 2, and the general structural formula 3, * is the connection point of the general structural formula 1 and the general structural formula 2, and any two adjacent connection points in the general structural formula 1 are connected with the connection point in the general structural formula 2 to obtain a condensed ring; o, i, r, s are independently non-negative integers in the range of 0-4; J is 0 or 1; A is benzene or naphthalene; X is N; Y is any one of O, S or NRb; Q is any one of O, S, C(Ra)(Rb) or N(Rc); W is a direct bond; h is 0 or 1; Ra and Rb are independently deuterium, tritium, hydrogen, halogen, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C6-C60 heteroaryl, substituted or unsubstituted C1-C50 alkyl, substituted or unsubstituted C1-C50 cycloalkyl, substituted or unsubstituted C1-C50 alkoxy, substituted or unsubstituted C5-C50 aryloxy, substituted or unsubstituted C5-C50 arylthio, substituted or unsubstituted C1-C50 alkoxy any one of alkylcarbonyl; Rc, R21, and R22 are independently deuterium, tritium, hydrogen, halogen, cyano, nitro, hydroxyl, substituted or unsubstituted C1-C18 alkyl, substituted or unsubstituted C2-C18 alkenyl, substituted or unsubstituted C2-C18 alkynyl, substituted or unsubstituted C3-C18 cycloalkyl, substituted or unsubstituted C1-C18 alkoxy, substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C5-C18 heteroaryl, substituted or unsubstituted C 5-C18 heterocyclic groups; L1, L2 and L3 are independently any one of a direct bond, a substituted or unsubstituted C6-C30 aryl group, or a substituted or unsubstituted C2-C30 heteroaryl group; Ar1 ​​and Ar2 are independently at least one of a substituted or unsubstituted C6-C30 aryl group, or a substituted or unsubstituted C3-C30 heteroaryl group; Ar3 and Ar4 are independently any one of a direct bond, an alkyl group, a cycloalkyl group, a heterocycloalkyl group, an alkenyl group, or an alkynyl group.

[0049] Specifically, "obtaining a fused ring" means connecting two or more ring structures by chemical reaction to form a larger ring structure that shares one or more carbon atoms. This structure is called a "fused ring" or "fused ring".

[0050] As shown in the general structural formula, there are four connection points in general structural formula 1 and two connection points in general structural formula 2, that is, the two connection points in general structural formula 2 are connected to any two connection points of the four connection points in general structural formula 1 to form a compound.

[0051] Specifically, the general structural formula 1 has a triazine group, that is, a nitrogen-containing six-membered heterocyclic compound; the general structural formula 2 has a phenanthroline group, that is, a nitrogen-containing five-membered ring; the phenanthroline group and the triazine group are connected, so that this type of chemical has a suitable lowest unoccupied molecular orbital (LUMO) energy level, which can be used as RH-N material, and can form an exciplex with a suitable RH-P material. When used as the main material of a red light device, it can be matched with a guest material to achieve red light emission. At the same time, the compound also has a suitable highest occupied molecular orbital (HOMO) energy level, which plays a role in blocking electrons, thereby achieving the best match with the adjacent functional layer.

[0052] Specifically, the compound composed of the phenanthroline oxazole group and the triazine group has a rigid structure, and the molecular structure has a relatively stable geometric configuration, so that the molecule is not easily deformed under the action of an external electric field, and its reorganization energy is low.

[0053] Specifically, when the compound has a more rigid structure, that is, the compound has a higher glass transition temperature, this can improve the film-forming property and thermal stability of the compound, thereby further improving the luminescence life and operational stability of the device. The compound in the present application is very stable and has a stable stereo configuration, which can reduce the interaction between molecules and avoid the red shift of the spectrum of the host material under thin film conditions, which causes the excitons formed on the host material to be unable to be effectively transferred to the guest, thereby improving the guest luminescence efficiency and the efficiency of the device.

[0054] Specifically, the phenanthroline oxazole group and triazine group contained in the compound can form a good conjugation, which can make the molecule more planar, which can improve the carrier mobility of the main material and the exciton recombination rate, thereby reducing the operating voltage of the device and making it have a higher application value. In addition, due to the good conjugation of the fused compound, under the premise of introducing a high T1 fragment into the molecule, the T1 electron cloud of this type of fused compound is mainly concentrated on the fused fragment, so that this type of material has a suitable T1 energy level when used as a red light host, and can have good energy transfer with the doping material, thereby reducing energy loss and improving the efficiency of the device.

[0055] It should be understood that the connection point in the structural formula 1 that is not connected to the structural formula 2 can be hydrogen.

[0056] In some embodiments, the structural formula 1 is any one of the following structures:

[0057]

[0058]

[0059] In some embodiments, the general structural formula 3 is one of the following structures:

[0060]

[0061] In the general structural formula 3-1, the general structural formula 3-2, the general structural formula 3-3 and the general structural formula 3-4, G is a direct bond, any one of O, S, C, and N; E is any one of O, S, and N; a, b, c, d, e, f, g, m, n, and p are non-negative integers in the range of 0-4; and R1-R10 are independently deuterium, tritium, hydrogen, halogen, cyano, nitro, hydroxyl, substituted or unsubstituted C1-C18 alkyl, substituted or unsubstituted C2-C18 alkenyl, substituted or unsubstituted C2-C18 alkynyl, substituted or unsubstituted C3-C18 cycloalkyl, substituted or unsubstituted C1-C18 alkoxy, substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C5-C18 heteroaryl, or substituted or unsubstituted C5-C18 heterocyclyl.

[0062] Specifically, the aryl, heteroaryl, alkyl, cycloalkyl, alkoxy, aryloxy, arylthio, and alkoxycarbonyl groups may be substituted by any of the following groups: deuterium, tritium, hydrogen, C1-C30 alkyl, halogenated C1-C30 alkyl, halogen, cyano, C3-C30 cycloalkyl, C5-C30 heterocycloalkyl, C2-C30 alkenyl, C2-C30 alkynyl, C6-C30 aryl, C1-C30 alkoxy, C6-C30 aryloxy, C2-C30 heteroaryl, C6-C30 aryl-substituted C1-C30 heteroaryl, C6-C30 arylC1-C30 alkyl, C1-C30 C1-C30 alkyl C6-C30 aryl group, C6-C30 arylthio group, mono- or di-C1-C30 alkylamino group, mono- or di-C6-C30 arylamino group, C1-C30 alkyl C6-C30 arylamino group, di-C6-C30 arylboryl group, di-C1-C30 alkylboryl group, C1-C30 alkyl C6-C30 arylboryl group, tri-C1-C30 alkylsilyl group, di-C1-C30 alkyl C6-C30 arylsilyl group, C1-C30 alkyl di-C6-C30 arylsilyl group, tri-C6-C30 arylsilyl group, N-carbazolyl group, carboxyl group, nitro group and hydroxyl group.

[0063] In some embodiments, at least one of Ra, Rb, Rc, R21, R22, R1-R10 is deuterium.

[0064] The T1 electron cloud of the fused compound is mainly concentrated on the fused fragment. Therefore, when the device is working, a large number of triplet excitons are generated on the main material, and triplet-triplet annihilation (TTA) annihilation occurs, and high-energy intermediates are generated. These high-energy intermediates will cause the fission of the material, thereby affecting the service life of the device. Therefore, by introducing deuterium substitution, that is, performing a certain range of D generation on the fused fragment, the electrical stability of the compound can be enhanced through D generation, and the bond energy of the host and guest materials can be enhanced, so that the material can avoid the generation of high-energy intermediates during TTA, causing the material to deteriorate, thereby improving the efficiency and life of the material.

[0065] In some embodiments, the triplet energy level T1 of the compound satisfies: 2.1 eV≤T1≤2.5 eV.

[0066] In some embodiments, the reorganization energy λ of the compound satisfies: λ≤0.3 eV.

[0067] In some embodiments, the absolute value of the energy value of the highest occupied molecular orbital of the compound satisfies: 5.0 eV≤|HOMO|≤5.9 eV.

[0068] In some embodiments, the absolute value of the energy value of the lowest unoccupied molecular orbital of the compound satisfies: 1.8 eV≤|LUMO|≤2.2 eV.

[0069] By controlling the T1, λ, LUMO and HOMO of the compound within the above ranges, the device can have better performance.

[0070] Specifically, the triplet energy level T1 of the compound may be 2.1 eV, 2.15 eV, 2.18 eV, 2.2 eV, 2.5 eV or any value within the above range.

[0071] Specifically, the reorganization energy λ of the compound may be 0.1 eV, 0.15 eV, 0.18 eV, 0.23 eV, 0.29 eV or any value within the above range.

[0072] Specifically, the HOMO of the compound may be 5.1 eV, 5.3 eV, 5.5 eV, 5.6 eV, 5.9 eV or any value within the above range.

[0073] Specifically, the LUMO of the compound may be 1.8 eV, 1.9 eV, 2.1 eV, 2.15 eV, 2.2 eV or any value within the above range.

[0074] As described above, the light emitting device 100 includes the first electrode 120 , the light emitting layer 134 , and the second electrode 140 .

[0075] In some embodiments, the light emitting layer 134 includes a first material, and the first material includes a compound according to any of the above embodiments.

[0076] In some embodiments, the light emitting layer 134 further includes a second material, and the absolute value difference of HOMO between the first material and the second material satisfies: Δ|HOMO|≤0.5 eV.

[0077] In the above scheme, by making the HOMO difference between the first material and the second material no greater than 0.5 eV, that is, the difference between the RH-P material and the RH-N material no greater than 0.5 eV, it is beneficial to form a suitable band gap, thereby maintaining normal charge transfer.

[0078] The detailed structure of Het is listed in detail below, but the structure of Het is not limited to the following form.

[0079]

[0080]

[0081] The detailed structures of L1, L2, and L3 in the general structural formula 1 and the general structural formula 2 are listed in detail below, but the structures of L1, L2, and L3 are not limited to the following forms.

[0082]

[0083] The detailed structures of Ar1 and Ar2 in the general structural formula 1 and the general structural formula 2 are listed in detail below, but the structures of Ar1 and Ar2 are not limited to the following forms.

[0084]

[0085]

[0086]

[0087] The detailed structures of the compounds composed of Structural Formula 1 and Structural Formula 2 are listed in detail below, but the structures of the compounds are not limited to the following forms.

[0088]

[0089]

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097]

[0098]

[0099]

[0100]

[0101]

[0102]

[0103]

[0104]

[0105]

[0106]

[0107]

[0108]

[0109]

[0110]

[0111]

[0112]

[0113]

[0114]

[0115]

[0116]

[0117]

[0118]

[0119]

[0120]

[0121]

[0122]

[0123]

[0124]

[0125]

[0126]

[0127]

[0128]

[0129]

[0130]

[0131]

[0132]

[0133]

[0134]

[0135]

[0136]

[0137]

[0138] The use of the above compound in a display device can improve the efficiency and life of the display device and reduce the voltage of the display device.

[0139] The display device may be a display device such as an OLED display, or any product or component with a display function including such display devices, such as a television, a digital camera, a mobile phone, and a tablet computer.

[0140] The embodiments will be described in more detail below with reference to examples. However, these embodiments are not to be construed as limiting the scope of the present invention in any sense.

[0141] The following is a simple and exemplary method for synthesizing a compound, wherein, if a general formula is used, it means that all substances represented by the general formula are applicable to the reaction process.

[0142] 1. Preparation of Compound M with General Formula

[0143] 1-1. Intermediate M-1:

[0144]

[0145] In a three-necked flask, 1-1a, 1-1b, potassium acetate, DMSO and ditriphenylphosphine palladium dichloride were mixed, and then heated to reflux at 80°C for 3h under the protection of nitrogen, cooled to room temperature, and the generated solid was filtered. After filtration, the solid was washed with tetrahydrofuran, ethyl acetate, water and ethanol. After drying, the intermediate 1-1c was obtained.

[0146] Then, under a nitrogen atmosphere, 1-1c and 1-1d are placed in tetrahydrofuran in a ratio of 1:1.1, and the resulting mixture is stirred and refluxed. Thereafter, potassium carbonate is introduced into the mixture, the resulting mixture is fully stirred, and tetratriphenylphosphine palladium is introduced therein. After reacting for 12 hours, the temperature of the product is lowered to room temperature and the generated solid is filtered. After filtering, the solid is washed with tetrahydrofuran, ethyl acetate, water and ethanol, and dried to prepare intermediate 1-1e, i.e. intermediate M-1.

[0147] 1-2. Intermediate M-2:

[0148]

[0149] In a three-necked flask, 2-1a, 2-1b, potassium acetate, DMSO and ditriphenylphosphine palladium dichloride were mixed, and then heated to reflux at 80°C for 3h under the protection of nitrogen, cooled to room temperature, and the generated solid was filtered. After filtration, the solid was washed with tetrahydrofuran, ethyl acetate, water and ethanol. After drying, intermediate 2-1c, i.e. intermediate M-2, was obtained.

[0150] 1-3. Preparation of Compound M:

[0151]

[0152] The intermediate M-1 and intermediate M-2 prepared above are placed in tetrahydrofuran at an equivalent ratio of 1:1.1, and the resulting mixture is stirred and refluxed. Thereafter, potassium carbonate is introduced into the mixture, the resulting mixture is fully stirred, and tetratriphenylphosphine palladium is introduced therein. After reacting for 12 hours, the temperature of the product is reduced to room temperature and the generated solid is filtered. After filtering, the solid is washed with tetrahydrofuran, ethyl acetate, water and ethanol, and dried to prepare the final product, i.e., compound M.

[0153] The above is a complete preparation process of a compound M. The preparation processes of some other compounds M will be listed below, and the parts with the same preparation conditions as above will not be repeated. 2.

[0155] 3.

[0157] 4.

[0159] 5.

[0161] 6.

[0163]

[0164] It should be noted that the synthesis of the compound described by the above formula can be carried out using known methods. For example, a cross-coupling reaction using transition metals such as nickel and palladium. Other synthesis methods are CC, CN coupling reactions using transition metals such as magnesium or zinc. The above reactions are limited to the characteristics of mild reaction conditions and superior selectivity of various functional groups, and preferably Suzuki, Miyaura and other reactions.

[0165] 2. Performance test of compounds

[0166] 2.1 Preparation of Compound M

[0167] [Example 1]

[0168]

[0169] In a three-necked flask, 1-1a (25 mmol), 1-1b (30 mmol), potassium acetate (50 mmol), DMSO (200 ml) and ditriphenylphosphine palladium dichloride (0.5 g) were heated to reflux at 80 ° C for 3 hours under nitrogen protection, cooled to room temperature, and the generated solid was filtered. After filtration, the solid was washed with 100 ml of tetrahydrofuran, 500 ml of ethyl acetate, 500 ml of water, and 300 ml of ethanol. Drying gave the intermediate 1-1c with a yield of 94%.

[0170] Then under nitrogen atmosphere, 1-1c and 1-1d are put into 300ml tetrahydrofuran in a ratio of 1:1.1 (55.57mmol), and the resulting mixture is stirred and refluxed. Thereafter, potassium carbonate (167.70mmol) is introduced into the mixture, the resulting mixture is fully stirred, and then tetratriphenylphosphine palladium (1.67mmol) is introduced thereto. After reacting for 12 hours, the temperature of the product is reduced to normal temperature and the solid produced is filtered. After filtering, the solid is washed with 100ml tetrahydrofuran, 500ml ethyl acetate, 500ml water and 300ml ethanol. The resulting product is dried to prepare intermediate 1-1e (87.7%), i.e. intermediate M-1.

[0171]

[0172] The synthesis of intermediate 1-1g, namely intermediate M-2, can refer to the synthesis of 1-1c, and the yield is 90.2%.

[0173]

[0174] The synthesis of compound RH-1 can refer to the synthesis of 1-1e, and the yield is 87.3%.

[0175] [Example 2]

[0176]

[0177] The synthesis of compound RH-2 can refer to the synthesis of RH-1, and the yield is 92.5%.

[0178] [Example 3]

[0179]

[0180] The synthesis of compound RH-3 can refer to the synthesis of RH-1, and the yield is 89.8%.

[0181] [Example 4]

[0182]

[0183] The synthesis of compound RH-4 can refer to the synthesis of RH-1, and the yield is 88.2%.

[0184] [Example 5]

[0185]

[0186] The synthesis of compound RH-5 can refer to the synthesis of RH-1, and the yield is 89.8%.

[0187] [Example 6]

[0188]

[0189] The synthesis of compound RH-6 can refer to the synthesis of RH-1, and the yield is 90.6%.

[0190] [Example 7]

[0191]

[0192] The synthesis of compound RH-7 can refer to the synthesis of RH-1, and the yield is 86.7%.

[0193] [Example 8]

[0194]

[0195] The synthesis of compound RH-8 can refer to the synthesis of RH-1, and the yield is 83.2%.

[0196] [Example 9]

[0197]

[0198] The synthesis of compound RH-9 can refer to the synthesis of RH-1, and the yield is 80.6%.

[0199] [Example 10]

[0200]

[0201] The synthesis of compound RH-10 can refer to the synthesis of RH-1, and the yield is 81.4%.

[0202] [Example 11] - [Example 35]

[0203] Please refer to Table 1 for Examples 11-35 and Table 1 for the preparation process.

[0204] Table 1 Preparation process of Example 11 to Example 35

[0205]

[0206]

[0207]

[0208]

[0209] 2.2 Physical characterization: The HOMO, LUMO, λ and T1 of the above compounds were obtained by simulation calculation. The mobility was obtained by SCLC test (EOD: ITO / ET10 nm / ET:LiQ(1:150%)15nm / RH 110nm / ET:LiQ(1:150%)15nm / Yb 1nm / Mg:Ag(8:2)80nm). Please see Table 2 for the test results.

[0210] Table 2 Physical properties of Examples 1 to 35

[0211]

[0212]

[0213] According to the above simulation results, the compounds of the present application contain phenanthroline oxazole groups, which are connected to triazine groups (a linker may be contained between the two), so that the compounds have a suitable LUMO energy level and can be used as RH-N materials. They can form an exciplex with a suitable RH-P material and serve as the main material of a red light device, and can be combined with a guest material to achieve red light emission.

[0214] According to the above embodiments, the compound containing phenanthroline oxazole groups, that is, the compound having the general structural formula 2, can have a suitable HOMO energy level, so that the compound of the present invention, as the RH-N material of the red light host, can play a role in blocking electrons, thereby achieving the best match with the adjacent functional layer.

[0215] According to the above embodiments, the compounds constituting the present invention all have a rigid structure, and the molecular structure has a relatively stable geometric structure, so that the molecules are not easily deformed under the action of an external electric field, and their reorganization energy is lower.

[0216] When the material has a more rigid structure, it will have a higher glass transition temperature, which can improve the film-forming property and thermal stability of the compound, which is conducive to further improving the luminescence life and operational stability of the device. The compounds of the present application having the general structural formula 1 and the general structural formula 2 are very stable and have a stable stereo configuration, which can reduce the interaction between molecules and avoid the red shift of the spectrum of the host material under thin film conditions, thereby avoiding the reduction of the guest luminescence efficiency caused by the inability to effectively transfer the excitons formed on the host material to the guest.

[0217] According to the above embodiments, the electron mobility of the compounds including the general structural formula 1 and the general structural formula 2 is higher. The triazine group and the phenanthroline group can form a better conjugation, so that the planarity of the molecule is better, the carrier mobility of the host material can be improved, and the exciton recombination rate can be increased, thereby reducing the operating voltage of the device, making it have a higher application value.

[0218] Figure 2 is an electron cloud diagram of the excited state T1 of compound RH-1. Figure 2a is the electron cloud diagram of the hole, Figure 2b It is the electron cloud diagram of the electrons of the compound RH-1. According to the embodiment table and Figure 2, the T1 of the compound satisfying the general structural formula of the present application is low, that is, the fused group has a lower T1, which can better match the red light emission.

[0219] 2.3. Device performance test

[0220] Device preparation process:

[0221] (a) The glass plate with ITO was ultrasonically treated in a cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone-ethanol mixed solvent, and baked in a clean environment until the water was completely removed.

[0222] (b) Place the glass substrate with the anode in a vacuum chamber and evacuate the chamber to a vacuum of 1×10 -5 -1×10 -6 , a hole injection material is vacuum evaporated on the above-mentioned anode layer film to form a hole injection layer, wherein the thickness of the hole injection layer is 10 nm.

[0223] (c) A hole transport material is evaporated on the hole injection layer to form a hole transport layer, wherein the thickness of the hole transport layer is 100 nm.

[0224] (d) An electron blocking layer of a hole transporting element is deposited on the hole transporting layer by a vacuum evaporator, wherein the thickness of the electron blocking layer is 85 nm.

[0225] (e) A light-emitting layer of the device is vacuum evaporated on the electron blocking layer, wherein the light-emitting layer includes a host material and a guest material, and a multi-source co-evaporation method is used, wherein the weight ratio of the host material to the guest material is 98:2, and the host material includes a RH-N material and a RH-P material, and the weight ratio of the RH-N material to the RH-P material is 1:1, wherein the thickness of the light-emitting layer is 85 nm.

[0226] (f) A hole blocking layer of the device is vacuum evaporated on the light-emitting layer, wherein the thickness of the hole blocking layer is 5 nm.

[0227] (g) Vacuum-deposit the electron transport layer of the device on the hole blocking layer, wherein the thickness of the electron transport layer is 30 nm.

[0228] (h). Yb is vacuum evaporated on the electron transport layer as an electron injection layer, wherein the thickness of the electron injection layer is 1 nm.

[0229] (i) Mg / Ag was evaporated on the electron injection layer as the cathode layer of the device, wherein the thickness of the cathode layer was 100 nm and the Mg:Ag ratio was 1:9.

[0230] 2.4 Performance Characterization: The driving voltage and luminous efficiency of the above devices were tested at a fixed current density. Please see Table 5 for the test results.

[0231] Table 3 shows the materials used in the above-mentioned different levels, Table 4 shows the specific structures of the main materials of Comparative Examples 1-9, and Table 5 shows the specific performance tests of different devices.

[0232] It should be understood that in the following Examples 1-35 and Comparative Examples 1-9, except for the RH-N material in the light-emitting layer, the materials of the other layers are the same, which will not be described in detail below.

[0233] Table 3 Specific substances at different levels in the device

[0234]

[0235]

[0236] Table 4 Specific structures of the main materials of Comparative Examples 1-9

[0237]

[0238]

[0239] Table 5 Device performance test

[0240]

[0241]

[0242] By comparison, it can be seen that the nitrogen-containing compounds with structural formula 1 and structural formula 2 are applied in the light-emitting layer, that is, the compounds of the present application include a nitrogen heterocyclic structure (pyridine, pyrimidine or triazine) and a structure fused with a nitrogen-containing five-membered ring (thiazole and oxazole). When combined with the RH-P material to form an exciplex as the main material of the light-emitting layer, the target compound has a higher electron mobility, which helps to balance the electrons and holes in the light-emitting layer, broaden the recombination area of ​​the electrons and holes in the light-emitting layer, and thus improve the luminous efficiency of the electroluminescent, reduce the driving voltage of the organic electroluminescent, and increase the life of the device.

[0243] By comparison, it can be seen that the compound of the present application has a better rigid structure, and the better rigid structure enables the compound to have a higher glass transition temperature, which can improve the film-forming property and thermal stability of the compound, and further improve the life of the device.

[0244] By comparison, it can be seen that introducing heteroatoms such as O, S or N into the structure of the compound can make the material have greater polarity, improve the interface energy level between the material and the adjacent functional layer, improve the injection characteristics of the material, further strengthen the interaction with the adjacent functional layer, and reduce the operating voltage of the device.

[0245] By comparison, it can be seen that when the compound only includes structural formula 1 and does not include structural formula 2, that is, the structure shown in comparative examples 5-9, the compound has a higher LUMO energy level, which will cause the LUMO barrier between the RH-N material and the RD material to increase, which will increase the electron traps, so that some electrons will be captured by RD, resulting in a significant decrease in device efficiency.

[0246] It should be noted that the nitrogen-containing compound is more suitable as the RH-N material in the mixed host of the organic electroluminescent device, especially suitable for the RH-N material of the red light device. When the nitrogen-containing compound of the present application is used as the light-emitting layer material of the organic electroluminescent device, it will effectively improve the electronic transmission performance of the device, improve the luminous efficiency and service life of the device.

[0247] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A compound, characterized in that Including structural formula 1 and structural formula 2: [Structural formula 1] [Structural formula 2] Het in the general structural formula 1 satisfies the general structural formula 3: [Structural Formula 3] Wherein, in the general structural formula 1, the general structural formula 2, and the general structural formula 3: * is a connection point between the structural formula 1 and the structural formula 2, and any two adjacent connection points in the structural formula 1 are connected with the connection point in the structural formula 2 to obtain a condensed ring; o, i, r, s are independently non-negative integers between 0 and 4; J is 0 or 1; A is benzene or naphthalene; X is N; Y is any one of O, S or N(Rb); Q is any one of O, S, C(Ra)(Rb) or N(Rc); W is a direct key; h is 0 or 1; Ra and Rb are independently any one of deuterium, tritium, hydrogen, halogen, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C6-C60 heteroaryl, substituted or unsubstituted C1-C50 alkyl, substituted or unsubstituted C1-C50 cycloalkyl, substituted or unsubstituted C1-C50 alkoxy, substituted or unsubstituted C5-C50 aryloxy, substituted or unsubstituted C5-C50 arylthio, substituted or unsubstituted C1-C50 alkoxycarbonyl; Rc, R21, and R22 are independently any one of deuterium, tritium, hydrogen, halogen, cyano, nitro, hydroxyl, substituted or unsubstituted C1-C18 alkyl, substituted or unsubstituted C2-C18 alkenyl, substituted or unsubstituted C2-C18 alkynyl, substituted or unsubstituted C3-C18 cycloalkyl, substituted or unsubstituted C1-C18 alkoxy, substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C5-C18 heteroaryl, and substituted or unsubstituted C5-C18 heterocyclyl; L1, L2 and L3 are independently any one of a direct bond, a substituted or unsubstituted C6-C30 aryl group, or a substituted or unsubstituted C2-C30 heteroaryl group; Ar1 and Ar2 are independently any one of a substituted or unsubstituted C6-C30 aryl group and a substituted or unsubstituted C3-C30 heteroaryl group; Ar3 and Ar4 are independently any one of a direct bond, an alkyl group, a cycloalkyl group, a heterocycloalkyl group, an alkenyl group, and an alkynyl group.

2. The compound according to claim 1, characterized in that The general structural formula 1 is any one of the following structures:

3. The compound according to claim 2, characterized in that The general structural formula 3 is one of the following structures: In the general structural formula 3-1, the general structural formula 3-2, the general structural formula 3-3 and the general structural formula 3-4: G is any one of a direct bond, O, S, C, and N; E is any one of O, S, and N; a, b, c, d, e, f, g, m, n, p are non-negative integers between 0 and 4; R1-R10 are independently deuterium, tritium, hydrogen, halogen, cyano, nitro, hydroxyl, substituted or unsubstituted C1-C18 alkyl, substituted or unsubstituted C2-C18 alkenyl, substituted or unsubstituted C2-C18 alkynyl, substituted or unsubstituted C3-C18 cycloalkyl, substituted or unsubstituted C1-C18 alkoxy, substituted or unsubstituted C6-C18 aryl, substituted or unsubstituted C5-C18 heteroaryl, substituted or unsubstituted C5-C18 heterocyclyl.

4. The compound according to claim 3, characterized in that At least one of the Ra, the Rb, the Rc, the R21, the R22, and the R1-R10 is deuterium.

5. The compound according to any one of claims 1 to 4, characterized in that The triplet energy level T1 of the compound satisfies: 2.1 eV≤T1≤2.5 eV.

6. The compound according to any one of claims 1 to 4, characterized in that The reorganization energy λ of the compound satisfies: λ≤0.3 eV.

7. The compound according to any one of claims 1 to 4, characterized in that The absolute value of the energy value of the highest occupied molecular orbital of the compound satisfies: 5.0 eV≤|HOMO|≤5.9 eV.

8. The compound according to any one of claims 1 to 4, characterized in that The absolute value of the energy value of the lowest unoccupied molecular orbital of the compound satisfies: 1.8 eV≤|LUMO|≤2.2 eV.

9. A light emitting device, characterized in that: It includes a first electrode, a light-emitting layer and a second electrode which are stacked in sequence; The light emitting layer comprises a first material, and the first material comprises the compound according to any one of claims 1 to 8.

10. The light emitting device according to claim 9, characterized in that: The light-emitting layer further includes a second material, and the absolute value difference of the energy values ​​of the highest occupied molecular orbitals of the first material and the second material satisfies: Δ|HOMO|≤0.5 eV.

11. A display device, characterized in that: The invention comprises the compound as claimed in any one of claims 1 to 8, or comprises the light-emitting device as claimed in claim 9 or 10.

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