Compound, light-emitting device, display substrate and display device

Abstract

The invention provides a compound, a light-emitting device, a display substrate and a display device, the structural formula of the compound is as shown in a general formula (1): # imgabs0 #, the structural formula of G is as shown in a general formula (2), and two wavy lines respectively represent connection positions of G with a triazine structure and L in the general formula (1); the proportion of the electron cloud of the LUMO energy level of the compound on G is 3%-60%; x is O, S, C (R1) (R2) or N (R3); a is phenyl or naphthyl, and Het is substituted or unsubstituted dibenzofuran at least containing one N atom, substituted or unsubstituted dibenzothiophene at least containing one N atom, substituted or unsubstituted benzodibenzofuran at least containing one N atom, and substituted or unsubstituted benzodibenzothiophene at least containing one N atom.

Description

Technical Field

[0001] The present disclosure belongs to the field of display technology, and particularly relates to a compound, a light-emitting device, a display substrate and a display apparatus. Background Art

[0002] Organic Electroluminescence Display (OLED) has the advantages of being light, thin, self-luminous, low power consumption, no backlight, wide viewing angle, and fast response. It has gradually replaced liquid crystal display panels to become a new generation of flat panel displays, and it also has great potential in flexible displays. At present, OLED has been gradually applied to high-end display fields such as mobile phones, wearable devices, vehicles and computers. Many companies are also developing foldable and curlable OLED screens to meet people's requirements for large-screen experience and product portability. The organic electron transport materials in OLED devices have a significant impact on their performance. The currently disclosed electron transport materials need to be improved in efficiency and lifespan. Therefore, the development of stable and efficient electron transport materials, the improvement of device efficiency, and the extension of device lifespan have very important practical application value. Summary of the invention

[0003] In a first aspect, the present disclosure provides a compound, wherein the structural formula of the compound is shown in general formula (1):

[0004]

[0005] Wherein, the structural formula of G is as shown in the general formula (2), wherein the two wavy lines respectively represent the positions where G is connected to the triazine structure and L in the general formula (1); the electron cloud of the LUMO energy level of the compound accounts for 3% to 60% on G;

[0006] X is O, S, C(R1)(R2), N(R3); A is phenyl or naphthyl;

[0007] R1, R2, and R3 are the same as or different from each other, and are each independently selected from any one of hydrogen, deuterium, a halogen atom, a cyano group, a nitro group, a hydroxyl group, a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C2-C20 alkenyl group, a substituted or unsubstituted C2-C18 alkynyl group, a substituted or unsubstituted C3-C18 cycloalkyl group, a substituted or unsubstituted C1-C18 alkoxy group, a substituted or unsubstituted C6-C60 aryl group, a substituted or unsubstituted 5-60-membered heteroaryl group, and a substituted or unsubstituted 5-18-membered heterocyclyl group;

[0008] Ar1 and Ar2 represent substituted or unsubstituted C6-C60 aryl, or substituted or unsubstituted 6- to 60-heteroaryl;

[0009] L is a direct bond, alkyl, cycloalkyl, heterocycloalkyl, alkenyl, alkynyl, aryl and heteroaryl may be further substituted independently by one or more groups selected from the group consisting of deuterium, (C1-C30)alkyl, halo(C1-C30)alkyl, halogen, cyano, (C3-C30)cycloalkyl, 5-membered to 7-membered heterocycloalkyl, (C2-C30)alkenyl, (C2-C30)alkynyl, (C6-C30)aryl, (C1-C30)alkoxy, (C6-C30)aryloxy, (C2-C30)heteroaryl, (C6-C30)aryl-substituted (C2-C30)heteroaryl, (C6-C30)aryl(C1-C30)alkyl, (C1-C30) )alkyl(C6-C30)aryl, (C6-C30)arylthio, mono- or di-(C1-C30)alkylamino, mono- or di-(C6-C30)arylamino, (C1-C30)alkyl(C6-C30)arylamino, di-(C6-C30)arylboryl, di-(C1-C30)alkylboryl, (C1-C30)alkyl(C6-C30)arylboryl, tri-(C1-C30)alkylsilyl, di-(C1-C30)alkyl(C6-C30)arylsilyl, (C1-C30)alkyldi-(C6-C30)arylsilyl, tri-(C6-C30)arylsilyl, N-carbazolyl, carboxyl, nitro and hydroxyl;

[0010] The structural formula of Het is one of the following general formula (2-1), general formula (2-2), general formula (2-3), and general formula (2-4):

[0012]

[0013] X1, X2, X3, and X4 represent S or O, C, or N, A1 to A10 each independently represent CH, C(Ra), or N, B1 to B10 each independently represent CH, C(Rb), or N, E1 to E10 each independently represent CH, C(Rc), or N, and Y1 to Y8 each independently represent CH, C(Rc), or N;

[0014] At least one of A1 to A10 in the general formula (2-1) is N, at least one of B1 to B10 in the general formula (2-2) is N, at least one of E1 to E10 in the general formula (2-3) is N, and at least one of Y1 to Y8 in the general formula (2-4) is N;

[0015] Ra, Rb, and Rc are the same as or different from each other and are independently selected from hydrogen, deuterium, a halogen atom, a hydroxyl group, a cyano group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 ring carbon atoms, a substituted or unsubstituted arylthio group having 6 to 30 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, and a substituted or unsubstituted heterocyclic group having 5 to 30 ring atoms.

[0016] In some embodiments, when there are multiple Ra, multiple Rb, and multiple Rc, adjacent Ra, adjacent Rb, and adjacent Rc are independently bonded to each other to form a ring structure.

[0017] In some embodiments, the structure represented by the general formula (1) is selected from any one of the following structural formulas:

[0018]

[0019] In some embodiments, the LUMO energy level of the compound is between 1.8 eV and 2.3 eV.

[0020] In some embodiments, the reorganization energy of the compound is less than or equal to 0.4 eV.

[0021] In some embodiments, the triplet energy level of the compound is between 2.0 eV and 2.6 eV.

[0022] In a second aspect, the present disclosure further provides a light-emitting device, which includes a first electrode, a light-emitting layer, and a second electrode stacked in sequence, wherein the light-emitting layer includes a first material, and the first material includes the above-mentioned compound.

[0023] In some embodiments, the light-emitting layer includes a host material and a guest material, the host material includes an electronic host material and a hole host material, the electronic host material includes the first material, and the structure of the hole host material is as follows:

[0024]

[0025] The electron-type host material forms an exciplex with the hole-type host material.

[0026] In some embodiments, the HOMO energy level of the hole-type host material is between 5.0 eV and 5.4 eV.

[0027] In some embodiments, the weight ratio of the hole-type host material to the electron-type host material is between 1:9 and 9:1.

[0028] In some embodiments, the weight percentage of the guest material in the light-emitting layer is between 1 wt % and 3 wt %.

[0029] In some embodiments, the light-emitting device further includes: a hole injection layer, a hole transport layer, and an electron blocking layer, which are located between the first electrode and the light-emitting layer and are sequentially arranged in a direction close to the light-emitting layer, and the absolute value of the difference between the HOMO energy level of the electron blocking layer and the HOMO energy level of the hole-type host material is less than or equal to 0.3 eV.

[0030] In some embodiments, the light-emitting device further includes: an electron injection layer, an electron transport layer, and a hole blocking layer, which are located between the second electrode and the light-emitting layer and are sequentially arranged in a direction close to the light-emitting layer, and the absolute value of the difference between the LUMO energy level of the hole blocking layer and the LUMO energy level of the electronic-type host material is less than or equal to 0.3 eV.

[0031] In some embodiments, the light-emitting device further comprises: an electron injection layer, an electron transport layer and a hole blocking layer, which are located between the second electrode and the light-emitting layer and are sequentially arranged in a direction close to the light-emitting layer, wherein the HOMO energy level of the hole blocking layer is greater than the HOMO energy level of the electronic host material, and the difference between the two is greater than or equal to 0.3 eV;

[0032] The light-emitting device also includes: a hole injection layer, a hole transport layer and an electron blocking layer located between the first electrode and the light-emitting layer and arranged in sequence along a direction close to the light-emitting layer, the LUMO energy level of the electron blocking layer is greater than the LUMO energy level of the hole-type host material, and the difference between the two is greater than or equal to 0.3eV.

[0033] In some embodiments, the absolute value of the difference between the molecular weight of the hole-type host material and the molecular weight of the electron-type host material is less than or equal to 300.

[0034] In some embodiments, the molecular weight of the hole-type host material and the molecular weight of the electron-type host material are both greater than or equal to 600, and the molecular weight of the guest material is between 700 and 1500.

[0035] In some embodiments, the distance between the electron cloud of the HOMO energy level of the hole-type host material and the electron cloud of the LUMO energy level of the electron-type host material is between 3 and 5 angstroms.

[0036] In some embodiments, the emission wavelength λ of the hole-type host material is P The emission wavelength λ of the electronic host material is between 380nm and 430nm. N The emission wavelength of the exciplex is λe between 420nm and 480nm, wherein:

[0037] λe-λ P ≥20nm,λe-λ N ≥20nm.

[0038] In some embodiments, the light-emitting device further includes: a hole injection layer, a hole transport layer, and an electron blocking layer located between the first electrode and the light-emitting layer and sequentially arranged in a direction close to the light-emitting layer, the electron blocking layer includes a first sub-blocking layer and a second sub-blocking layer sequentially arranged in a direction close to the light-emitting layer, the thickness of the first sub-blocking layer is greater than the thickness of the second sub-blocking layer, and the mobility of the first sub-blocking layer is greater than the mobility of the second sub-blocking layer.

[0039] In some embodiments, the light-emitting device further comprises: a hole injection layer, a hole transport layer, and an electron blocking layer, which are located between the first electrode and the light-emitting layer and are sequentially arranged in a direction close to the light-emitting layer, and an electron injection layer, an electron transport layer, and a hole blocking layer, which are located between the second electrode and the light-emitting layer and are sequentially arranged in a direction close to the light-emitting layer;

[0040] The mobility of the hole blocking layer is 10 -7 ~10 -9 cm 2 V -1 s -1 @5000V 1 / 2 / m 1 / 2 between,

[0041] The mobility of the electron transport layer is 10 -5 ~10 -7 cm 2 V -1 s -1 @5000V 1 / 2 / m 1 / 2 between,

[0042] The mobility of the hole transport layer is 10 -4 ~10 -6 cm 2 V -1 s -1 @5000V 1 / 2 / m 1 / 2 between,

[0043] The mobility of the electron blocking layer is 10 -4 ~10 -7 cm 2 V -1 s -1 @5000V 1 / 2 / m 1 / 2 between.

[0044] In some embodiments, the light-emitting device further comprises: a hole injection layer, a hole transport layer and an electron blocking layer, which are disposed between the first electrode and the light-emitting layer and in sequence in a direction close to the light-emitting layer, and an electron injection layer, an electron transport layer and a hole blocking layer, which are disposed between the second electrode and the light-emitting layer and in sequence in a direction close to the light-emitting layer; the electron blocking layer comprises a first sub-blocking layer and a second sub-blocking layer, which are disposed in sequence in a direction close to the light-emitting layer;

[0045] The triplet energy level of the light emitting layer is lower than the triplet energy level of any one of the second sub-blocking layer and the hole blocking layer.

[0046] In some embodiments, the light-emitting layer is configured to emit red light;

[0047] The light-emitting layer further comprises a dopant, and the dopant is used to emit light with a wavelength between 600 and 650 nm; the light-emitting peak of the light-emitting layer is between 600 and 650 nm.

[0048] In a third aspect, the present disclosure further provides a display substrate, comprising the above-mentioned light-emitting device.

[0049] In a fourth aspect, the present disclosure further provides a display device, comprising the above-mentioned display substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 Spectral curves of different materials provided in some embodiments.

[0051] Figure 2 It is a schematic diagram of the structure of the light-emitting device provided in some embodiments of the present disclosure.

[0052] Figures 3 to 6 Schematic diagram of LUMO electron cloud distribution of different structures provided in some embodiments of the present disclosure.

[0053] Figure 7 A schematic diagram of a display substrate provided in some embodiments of the present disclosure. DETAILED DESCRIPTION

[0054] In order to enable those skilled in the art to better understand the technical solution of the present disclosure, the present disclosure is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0055] Unless otherwise defined, the technical terms or scientific terms involved in the present disclosure shall be the common meanings understood by people with ordinary skills in the technical field to which the present disclosure belongs. The words "one", "a", "a", "the" and the like involved in the present disclosure do not indicate a quantity limitation, and may indicate the singular or the plural. The terms "include", "comprise", "have" and any of their variations involved in the present disclosure are intended to cover non-exclusive inclusions; for example, a process, method, system, product or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units that are not listed, or may also include other steps or units inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like involved in the present disclosure are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The "multiple" involved in the present disclosure refers to two or more. "And / or" describes the association relationship of associated objects, indicating that there may be three relationships, for example, "A and / or B" may indicate: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the objects before and after are in an "or" relationship. The terms "first", "second", "third", etc. involved in the present disclosure are only used to distinguish similar objects and do not represent a specific ordering of the objects. "Up", "down", "left", "right", etc. are only used to indicate a relative position relationship. When the absolute position of the described object changes, the relative position relationship may also change accordingly.

[0056] The OLED device includes an anode, a hole injection layer (HIL), a hole transport layer (HTL), an electron blocking layer 14 (EBL), an emitting layer (EML), a hole blocking layer (HBL), an electron transport layer (ETL), an electron injection layer 18 (EIL) and a cathode, which are 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 move to the emitting layer via hole transport, and the electrons injected from the cathode move to the emitting layer via the electron transport layer. The holes and electrons recombine in the emitting layer to generate excitons, and 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.

[0057] In OLED devices, the excitons formed by the recombination of electrons and holes are not restricted by the law of spin. 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. Phosphorescence Organic Light-Emitting Diode (PHOLED) devices can utilize excited singlet and excited triplet states at the same time, and use spin-orbit coupling to allow 75% of triplet excitons that could not be used to transition to the ground state, breaking the limitation of OLED devices that the internal quantum efficiency is no more 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.

[0058] 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.

[0059] 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.

[0060] Among them, the host material used in organic electrophosphorescent devices should have the following properties:

[0061] (1) Have good charge transport properties: The main material must have certain transport properties (holes and electrons), and the transport properties of holes and electrons, in other words, the balance of holes and electrons, determine the position of the exciton recombination area in the EML layer, and the position of the exciton recombination area will affect the life and efficiency of the device. Too many or too few holes will lead to reduced device efficiency. If the exciton recombination area is far away from the center of the EML and close to an adjacent layer, it will affect the electron resistance and hole resistance of the material layer, thereby degrading the material layer and causing the device life to deteriorate. Specifically: RH-P has a higher hole mobility, and RH-N has a higher electron mobility.

[0062] (2) There is a good energy level match between the host and the guest: Generally, the energy gap of the host is required to be larger than that of the guest, so that the exciton energy can be effectively transferred to the guest molecule to emit phosphorescence, or the charge can be directly trapped on the guest to form exciton radiation decay and emit phosphorescence. RH-P has a suitable HOMO and RH-N has a suitable LUMO.

[0063] (3) Appropriate singlet energy level (S1 energy level) and triplet energy level (T1 energy level): The energy level of the host material is higher than the T1 energy level of the guest material (RD), which can ensure that the excitons formed on the host material transfer energy to the phosphorescent guest, causing it to emit red light. Figure 1 are spectral curves of different materials provided in some embodiments, Figure 1 Spectral curves of guest materials, hole-type host materials, electron-type host materials, and exciplexes are shown in FIG. Figure 1 The horizontal axis represents the wavelength, the vertical axis represents the normalized intensity, and the shaded area represents the overlapping area between the absorption spectrum of the excited complex and the spectrum of the guest material, that is, the energy of the host material can be transferred to the guest material by energy transfer.

[0064] (4) It usually must have certain phosphorescence properties. At low temperatures, its phosphorescence peak wavelength is shorter than that of the guest phosphorescent material, that is, the T1 energy level of the host material is required to be greater than the T1 energy level of the guest material, and it has a longer phosphorescence lifetime. The energy level structure matching between the host material and the guest material is the key factor restricting the luminescence efficiency of the device.

[0065] (5) The main material has good film-forming properties, ensuring that the material can form a good amorphous film.

[0066] (6) Thermal stability: The main material needs to have excellent thermal stability to prevent the device performance from deteriorating (such as material cracking during the evaporation process, which leads to a decrease in device life).

[0067] The embodiments of the present disclosure provide a compound that can be used as a host material and mixed with a phosphorescent material to be applied to a light-emitting device, thereby improving the efficiency and life of the light-emitting device and reducing the voltage of the light-emitting device. Figure 2 is a schematic diagram of the structure of a light-emitting device provided in some embodiments of the present disclosure, such as Figure 2 As shown, the light emitting device includes: a first electrode 11, a light emitting layer and a second electrode 19 stacked in sequence on a substrate 10. The material of the first electrode 11 includes, for example, indium tin oxide (ITO), and the material of the second electrode 19 includes a metal, for example, magnesium silver (Mg / Ag) alloy.

[0068] In a specific example, the light-emitting device includes: a first electrode 11, a hole injection layer 12, a hole transport layer 13, an electron blocking layer 14, a light-emitting layer 15, a hole blocking layer 16, an electron transport layer 17, an electron injection layer 18 and a second electrode 19, which are sequentially arranged in a direction away from the substrate. The compound in the embodiment of the present disclosure is applied to the light-emitting layer.

[0069] The structural formula of the compound provided in the embodiments of the present disclosure is shown in the following general formula (1):

[0070]

[0071] Wherein, the structural formula of G is shown in the general formula (2), wherein the two wavy lines respectively represent the positions where G is connected to the triazine structure and L in the general formula (1); specifically, the structural formula of the compound in the embodiment of the present disclosure can be shown as follows:

[0072]

[0073] The electron cloud of the LUMO energy level of the compound accounts for 3% to 60% on G; X is O, S, C (R1) (R2), N (R3); and A is phenyl or naphthyl.

[0074] R1, R2, and R3 are the same as or different from each other and are each independently selected from any one of hydrogen, deuterium, a halogen atom, a cyano group, a nitro group, a hydroxyl group, a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C2-C20 alkenyl group, a substituted or unsubstituted C2-C18 alkynyl group, a substituted or unsubstituted C3-C18 cycloalkyl group, a substituted or unsubstituted C1-C18 alkoxy group, a substituted or unsubstituted C6-C60 aryl group, a substituted or unsubstituted 5-60 membered heteroaryl group, and a substituted or unsubstituted 5-18 membered heterocyclyl group.

[0075] Ar1 and Ar2 represent substituted or unsubstituted C6-C60 aryl, or substituted or unsubstituted C6- to C60 heteroaryl.

[0076] L is a direct bond, alkyl, cycloalkyl, heterocycloalkyl, alkenyl, alkynyl, aryl and heteroaryl may be further substituted independently by one or more groups selected from the group consisting of deuterium, (C1-C30)alkyl, halo(C1-C30)alkyl, halogen, cyano, (C3-C30)cycloalkyl, 5-membered to 7-membered heterocycloalkyl, (C2-C30)alkenyl, (C2-C30)alkynyl, (C6-C30)aryl, (C1-C30)alkoxy, (C6-C30)aryloxy, (C2-C30)heteroaryl, (C6-C30)aryl-substituted (C2-C30)heteroaryl, (C6-C30)aryl(C1-C30)alkyl, (C1-C30) )alkyl(C6-C30)aryl, (C6-C30)arylthio, mono- or di-(C1-C30)alkylamino, mono- or di-(C6-C30)arylamino, (C1-C30)alkyl(C6-C30)arylamino, di-(C6-C30)arylboryl, di-(C1-C30)alkylboryl, (C1-C30)alkyl(C6-C30)arylboryl, tri-(C1-C30)alkylsilyl, di-(C1-C30)alkyl(C6-C30)arylsilyl, (C1-C30)alkyldi-(C6-C30)arylsilyl, tri-(C6-C30)arylsilyl, N-carbazolyl, carboxyl, nitro and hydroxyl groups.

[0077] In some embodiments, the structural formula of Het is one of the following general formula (2-1), general formula (2-2), general formula (2-3), and general formula (2-4):

[0078]

[0079] X1, X2, X3, and X4 represent S or O, C, and N, A1 to A10 each independently represent CH, C(Ra), or a nitrogen atom N, B1 to B10 each independently represent CH, C(Rb), or a nitrogen atom N, E1 to E10 each independently represent CH, C(Rc), or a nitrogen atom N, and Y1 to Y8 each independently represent CH, C(Rc), or a nitrogen atom N.

[0080] At least one of A1 to A10 in the general formula (2-1) is N, at least one of B1 to B10 in the general formula (2-2) is N, at least one of E1 to E10 in the general formula (2-3) is N, and at least one of Y1 to Y8 in the general formula (2-4) is N.

[0081] Ra, Rb, and Rc are the same as or different from each other and are independently selected from hydrogen, D, a halogen atom, a hydroxyl group, a cyano group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 ring carbon atoms, a substituted or unsubstituted arylthio group having 6 to 30 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, and a substituted or unsubstituted heterocyclic group having 5 to 30 ring atoms.

[0082] In some embodiments, when there are multiple Ra, multiple Rb, and multiple Rc, multiple Ra may be the same or different from each other, multiple Rb may be the same or different from each other, and multiple Rc may be the same or different from each other. When there are multiple R2, multiple R2 are the same or different from each other; adjacent Ra, adjacent Rb, and adjacent Rc are independently bonded to each other to form a ring structure.

[0083] The proportion of the electron cloud of the LUMO energy level of the compound provided by the present invention on G is 3% to 60%, the position where the triazine is connected to the benzene ring in the G structure has a significant effect on the proportion of the LUMO electron cloud on the G structure, and the substituent where Het is located also has a significant effect on the proportion of the LUMO electron cloud on the G structure.

[0084] The compounds provided by the present disclosure can have a suitable LUMO energy level by adjusting the connection position of triazine and benzene in the G structure, the connection position of the N hetero group and the G structure, and the position of the N hetero group in the general formula, and can be used as the N-type material of RH, and can form an exciplex with a suitable P-type material, and can be used as the main material of a red light device, and can be matched with a guest material to achieve red light emission.

[0085] Moreover, the compound of the present invention contains a group of the general formula Het, and by changing the substitution position and the position of N impurities, the compound, as an N-type material of the red light main body, has an appropriate HOMO energy level, plays a role in blocking electrons, and thus achieves the best match with the adjacent functional layer. In addition, the compound of the present invention 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 lower; at the same time, the more rigid structure makes the compound have a higher glass transition temperature, improves the film-forming property and thermal stability of the compound, and further improves the luminescence life and operational stability of the device. In addition, the G structure in the general formula (1) and the group where the triazine is located can form a better conjugation, so that the planarity of the molecule is better, the carrier mobility of the main material can be improved, and the exciton recombination rate can be improved, thereby reducing the operating voltage of the device, making it have a higher application value.

[0086] The compounds provided in the embodiments of the present disclosure contain a group of the general formula Het, which increases the spatial stereo configuration of the molecule, can reduce the interaction between molecules, and avoid the red shift of the spectrum of the host material under thin film conditions, so as to avoid the problem that the excitons formed on the host material cannot be effectively transferred to the guest, resulting in a decrease in the luminescence efficiency of the guest, thereby ensuring the efficiency of the device.

[0087] In the disclosed embodiments, hydrogen atoms include isotopes with different numbers of neutrons, namely protium, deuterium and tritium. H atoms are common elements in the film layer of OLED devices, and deuterium is an isotope of hydrogen. Carbon-deuterium bonds have shorter bond lengths, higher bond energies and lower vibrational energies than carbon-hydrogen bonds. Therefore, replacing hydrogen atoms in organic molecules with deuterium atoms is an effective means of regulating the physical and chemical properties of molecules. In organic small molecules of OLED devices, the introduction of deuterium can suppress molecular vibrations, narrow the spectrum (dopant materials), reduce bond lengths, increase bond energies, and improve molecular stability, thereby helping to extend the service life of the device. Deuterium substitution has the following advantages:

[0088] First, when hydrogen is replaced by deuterium, the chemical properties of the compound remain almost unchanged; second, the atomic weight of deuterium is twice that of hydrogen, so the physical properties of the deuterated compound may change. The vibration energy level of the deuterated compound becomes lower, and the deuterated compound can prevent the reduction of quantum efficiency caused by the van der Waals force between molecules or the collision caused by the vibration between molecules; third, the CD bond can improve the stability of the compound, which can improve the efficiency and life of the device; fourth, the more the number of deuterium substitutions increases, the more energy is required in the side reaction, so that the side reaction is difficult to occur, and the stability of the compound can also be greatly increased.

[0089] In some embodiments, the structure represented by general formula (1) is selected from any one of the following structural formulas:

[0090]

[0091] In some embodiments, Het can be represented by a group represented by any of the following structural formulas:

[0092]

[0093]

[0094]

[0095]

[0096]

[0097]

[0098]

[0099]

[0100] In some embodiments, L is represented by a group represented by any of the following structural formulas:

[0101]

[0102] Among them, * indicates the chemical bond connection point.

[0103] In some embodiments, Ar1 and Ar2 can be independently selected from the groups shown in the following structural formula:

[0104]

[0105]

[0106]

[0107]

[0108]

[0109]

[0110] In some embodiments, the structure represented by general formula (1) is selected from any one of the following structural formulas:

[0111]

[0112]

[0113]

[0114]

[0115]

[0116]

[0117]

[0118]

[0119]

[0120]

[0121]

[0122]

[0123]

[0124]

[0125]

[0126]

[0127]

[0128]

[0129]

[0130]

[0131]

[0132]

[0133] In some embodiments, the LOMO energy level of the compound is between 1.8 eV and 2.3 eV, such as between 1.8 eV and 1.9 eV; or between 1.9 eV and 2.0 eV; or between 2.0 eV and 2.2 eV; or between 2.2 eV and 2.3 eV.

[0134] In some embodiments, the triplet energy level T1 of the compound satisfies: 2.0 eV≤T1≤2.6 eV, for example, 2.1 eV≤T1≤2.2 eV, for example, 2.2 eV≤T1≤2.3 eV, for example, 2.3 eV≤T1≤2.4 eV, for example, 2.4 eV≤T1≤2.6 eV.

[0135] In some embodiments, the reorganization energy λ of the compound satisfies: λ≤0.4 eV. For example, 0.15 eV≤λ≤0.2 eV; for another example, 0.2 eV≤λ≤0.25 eV; for another example, 0.25 eV≤λ≤0.3 eV; for another example, 0.3 eV≤λ≤0.32 eV, for another example, 0.32 eV≤λ≤0.35 eV, for another example, 0.35 eV≤λ≤0.4 eV.

[0136] By controlling the T1, λ, and LUMO of the compound within the above ranges, the device can have better performance.

[0137] The following examples illustrate a 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.

[0138]

[0139] The synthesis of the compound represented 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 use 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 reactions such as Suzuki and Miyaura.

[0140] Several exemplary synthesis methods of compounds are given below:

[0141] (1) Synthesis of compound RH-1:

[0142]

[0143] Specifically, in a three-necked flask, 1-1a (25mmol), 1-1b (20mmol), potassium carbonate (40mmol), THF (200ml) and bis (tri-tert-butylphosphine) palladium (5mmol) were added, and the mixture was heated to reflux at 80°C for 3 hours under nitrogen protection, cooled to room temperature, and the solid produced was filtered. After filtration, the solid was washed with 100ml tetrahydrofuran, 500ml ethyl acetate, 500ml water, and 300ml ethanol. Intermediate 1-1c was dried to give a yield of 94%. Then under a nitrogen atmosphere, 1-1c (50mmol) and 1-1d were placed in 300m dioxanes in a ratio of 1:1.1, and the resulting mixture was stirred and refluxed. Thereafter, potassium acetate (165mmol) was introduced into the mixture, the resulting mixture was fully stirred, and tetratriphenylphosphine palladium (1.67mmol) was then introduced thereto. After reacting for 12 hours, the temperature of the product was reduced to room temperature and the resulting 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. The obtained product was dried to prepare Intermediate 11e (95.2%).

[0144] In a three-necked flask, 1-1a (25 mmol), 1-1b (20 mmol), potassium carbonate (40 mmol), THF (180 ml) and bis(tri-tert-butylphosphine) palladium (5 mmol) were added, heated to reflux at 90°C for 3 hours under nitrogen protection, cooled to room temperature, and the generated solid was filtered. After filtering, 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 compound RH-1 with a yield of 85.2%.

[0145] (2) Synthesis of compound RH-2:

[0146]

[0147] The synthesis of compound RH-2 can refer to the synthesis of RH-1, and the yield is 83.6%. (3) Synthesis of compound RH-3:

[0148]

[0149] The synthesis of compound RH-3 can refer to the synthesis of RH-1, and the yield is 69.4%. (4) Synthesis of compound RH-4:

[0150]

[0151]

[0152] The synthesis of compound RH-4 can refer to the synthesis of RH-1, and the yield is 87.6%. (5) Synthesis of compound RH-5:

[0153]

[0154] The synthesis of compound RH-5 can refer to the synthesis of RH-1, and the yield is 89.8%. (6) Synthesis of compound RH-6:

[0155]

[0156] The synthesis of compound RH-6 can refer to the synthesis of RH-1, and the yield is 90.6%. (7) Synthesis of compound RH-7:

[0157]

[0158] The synthesis of compound RH-7 can refer to the synthesis of RH-1, and the yield is 87.3%. (8) Synthesis of compound RH-8:

[0159]

[0160] The synthesis of compound RH-8 can refer to the synthesis of RH-1, and the yield is 82.4%.

[0161] (9) Synthesis of compound RH-9:

[0162]

[0163] The synthesis of compound RH-9 can refer to the synthesis of RH-1, and the yield is 85.7%.

[0164] (10) Synthesis of compound RH-10:

[0165]

[0166] The synthesis of compound RH-10 can refer to the synthesis of RH-1, and the yield is 84.2%.

[0167] Similarly, the compounds in Tables 1 to 4 below were synthesized:

[0168] Table 1

[0169]

[0170] Table 2

[0171]

[0172] Table 3

[0173]

[0174] Table 4

[0175]

[0176]

[0177] Among them, in Tables 1 to 4, the intermediate 1 in the synthesis examples of compounds RH-11 to RH-30 is respectively recorded as intermediate 1-11 to intermediate 1-30, and their structural formulas are as follows:

[0178]

[0179]

[0180]

[0181] Intermediate 1-29Intermediate 1-30

[0182] The structural formulas of products 11 to 30 in Tables 1 to 4 (i.e., the structural formulas of compounds RH-11 to RH-30) are as follows:

[0183]

[0184]

[0185]

[0186] It should be noted that some compounds are listed in Tables 1 to 4, and the preparation processes of the unlisted compounds are similar to those of the above compounds and will not be described in detail here.

[0187] Tables 5 and 6 show the distribution of LUMO electron clouds in molecules of some structures and the proportion of LUMO electron clouds on G.

[0188] Table 5

[0189]

[0190] Table 6

[0191]

[0192] Among them, the structural formulas of structures 1 to 14 are shown in the following structural formulas (7-1) to (7-14), respectively.

[0193]

[0194]

[0195]

[0196] The distribution of LUMO electron clouds in the molecules of structures 1 to 4 can be found in Figure 3 , the LUMO electron cloud distribution in the molecules of structure 5 to structure 7 can be found in Figure 4 , the LUMO electron cloud distribution in the molecules of structures 8 to 11 can be found in Figure 5 , the LUMO electron cloud distribution in the molecules of structures 12 to 14 can be found in Figure 6 .

[0197] Some performance parameters of the compounds of the present invention were measured: HOMO, LUMO, S1, and T1 of the above compounds were obtained by simulation calculation, and the mobility was obtained by SCLC test (EOD: ITO / ET10nm / ET: LiQ(1:150%)15nm / RH110nm / ET: LiQ(1:150%)15nm / Yb 1nm / Mg:Ag(8:2)80nm). The test results are shown in Tables 7 and 8.

[0198] Table 7

[0199]

[0200]

[0201] Table 8

[0202]

[0203] From the data in the above table, it can be seen that the compounds provided by the present disclosure have suitable T1, HOMO and LUMO energy levels, reorganization energy and mobility as red light hosts. From the above simulation results, it can be seen that the compounds provided by the present disclosure, by adjusting the connection position of triazine and benzene in the G structure, the connection position of the N hetero group and G, and the position of N hetero in the general formula, can make such compounds have suitable LUMO energy levels, used as electronic host materials, can form exciplexes with appropriate hole-type host materials, as host materials of red light devices, and match with guest materials to achieve red light emission.

[0204] The compound disclosed in the present invention contains a group of the general formula Het. By changing the substitution position and the position of N impurities, the compound, as an electronic host material of the red light emitting layer, has an appropriate HOMO energy level, plays a role in blocking electrons, and thus achieves the best match with the adjacent functional layer.

[0205] At the same time, the compounds disclosed in the present invention have a rigid structure, and the molecular structure has a relatively stable geometric configuration, so that the molecules are not easily deformed under the action of an external electric field, and their reorganization energy is lower; at the same time, the more rigid structure enables the compound to have a higher glass transition temperature, improves the film-forming property and thermal stability of the compound, and further improves the luminescence life and operational stability of the device. In addition, the G structure and the group where the triazine is located can form a better conjugation, so that the planarity of the molecule is better, the carrier mobility of the main 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. At the same time, the more rigid structure enables the compound to have a higher glass transition temperature, improves the film-forming property and thermal stability of the compound, and further improves the luminescence life and operational stability of the device. In addition, the electron cloud of the material T1 mainly depends on the group with a low T1, and the T1 electron cloud of the disclosed compound is distributed on G, and such material characteristics can better match the red light emission.

[0206] The compounds provided in the embodiments of the present disclosure contain a group of the general formula Het, which increases the spatial stereo configuration of the molecule, can reduce the interaction between molecules, and avoid the red shift of the spectrum of the host material under thin film conditions, so as to avoid the problem that the excitons formed on the host material cannot be effectively transferred to the guest material, thereby preventing the luminous efficiency of the guest material from being reduced and ensuring the efficiency of the device.

[0207] The light-emitting device in the embodiment of the present disclosure is introduced below. In a specific example, the light-emitting device includes: a first electrode 11, a hole injection layer 12, a hole transport layer 13, an electron blocking layer 14, a light-emitting layer 15, a hole blocking layer 16, an electron transport layer 17, an electron injection layer 18 and a second electrode 19, which are arranged in sequence in a direction away from the substrate.

[0208] The material of the substrate can be any transparent rigid or flexible substrate material, such as glass, polyimide and the like.

[0209] The material of the first electrode 11 is a high work function electrode material, such as transparent oxide ITO, IZO; alternatively, the first electrode 11 may also be a composite electrode formed by ITO / Ag / ITO, Ag / IZO, CNT / ITO, CNT / IZO, GO / ITO, GO / IZO, etc.

[0210] The material of the hole injection layer 12 can be an inorganic oxide, such as molybdenum oxide, titanium oxide, vanadium oxide, rhenium oxide, ruthenium oxide, chromium oxide, zirconium oxide, hafnium oxide, tantalum oxide, silver oxide, tungsten oxide, manganese oxide, etc., or a dopant of a strong electron-withdrawing system, such as F4TCNQ, HATCN, etc. P-type doping can also be performed on the hole transport material, and the thickness of the hole injection layer 12 can be 5 to 20 nm, and the hole injection layer 12 is formed by co-evaporation.

[0211] The hole transport layer 13 is made of a material with good hole transport properties, such as aromatic amine or carbazole materials, such as NPB, TPD, BAFLP, DFLDPBi, etc. The thickness of the hole transport layer 13 may be 100-2000 nm.

[0212] The electron blocking layer 14 also has good hole transport properties, and the light-emitting auxiliary layer can be a red light-emitting auxiliary layer, a green light-emitting auxiliary layer, or a blue light-emitting auxiliary layer, and the specific material can be an aromatic amine or carbazole material, such as CBP, PCzPA, etc. In one example, the electron blocking layer 14 can include a first sub-blocking layer 141 and a second sub-blocking layer 142 sequentially arranged in a direction close to the light-emitting layer 15.

[0213] The light-emitting layer 15 includes a first material, and the first material includes the compound provided in the above embodiment. The light-emitting layer 15 is used to emit red light, and its thickness is between 10 and 100 nm.

[0214] In some embodiments, the light emitting layer 15 includes a host material and a guest material, the host material includes an electron-type host material and a hole-type host material, the electron-type host material includes the above-mentioned compound, and the electron-type host material and the hole-type host material form an exciplex.

[0215] In some embodiments, the structure of the hole-type host material is as follows:

[0216]

[0217] In some embodiments, the HOMO energy level of the hole-type host material is between 5.0 eV and 5.4 eV.

[0218] In some embodiments, the weight ratio of the hole-type host material to the electron-type host material is between 1:9 and 9:1. For example, the weight ratio of the two is 1:1, or 4:6, or 6:4.

[0219] In some embodiments, the weight percentage of the guest material in the light emitting layer 15 is between 1 wt% and 3 wt% to ensure the light emitting effect of the light emitting layer 15. For example, the weight percentage of the guest material in the light emitting layer 15 is 1 wt%, or 2 wt%, or 3 wt%.

[0220] The hole blocking layer 16 and the electron transport layer 17 can be aromatic heterocyclic compounds, such as imidazole derivatives such as benzimidazole derivatives, imidazopyridine derivatives, benzimidazolephenanthridine derivatives; oxazine derivatives such as pyrimidine derivatives and triazine derivatives; quinoline derivatives, isoquinoline derivatives, phenanthroline derivatives and other compounds containing nitrogen-containing six-membered ring structures (also including compounds with phosphine oxide-based substituents on the heterocyclic ring. For example: OXD-7, TAZ, p-EtTAZ), BPhen, BCP, etc. The thickness of the hole blocking layer 16 is between 5 and 100 nm, and the thickness of the electron transport layer 17 is between 20 and 100 nm.

[0221] The material of the electron injection layer 18 is, for example, LiF, Yb, Mg, Ca or a compound thereof, and the thickness thereof is between 1 and 10 nm.

[0222] Among them, the HOMO energy level of the electron blocking layer 14 is recorded as HOMO (EBL), the HOMO energy level of the hole blocking layer 16 is recorded as HOMO (HBL), the HOMO energy level of the hole-type host material is recorded as HOMO (Host-P), and the HOMO energy level of the electron-type host material is recorded as HOMO (Host-N); the LUMO energy level of the electron blocking layer 14 is recorded as LUMO (EBL), the LUMO energy level of the hole blocking layer 16 is recorded as LUMO (HBL), the LUMO energy level of the hole-type host material is recorded as LUMO (Host-P), and the LUMO energy level of the electron-type host material is recorded as LUMO (Host-N).

[0223] In some embodiments, |HOMO(Host-P)-HOMO(EBL)|≤0.3eV, thereby reducing the energy level gap between the electron blocking layer 14 and the hole-type host material, which is beneficial to the transmission of holes. For example, |HOMO(Host-P)-HOMO(EBL)|=0; for another example, 0<|HOMO(Host-P)-HOMO(EBL)|≤0.1eV; for another example, 0.1<|HOMO(Host-P)-HOMO(EBL)|≤0.2eV; for another example, 0.2<|HOMO(Host-P)-HOMO(EBL)|≤0.3eV.

[0224] In some embodiments, |LUMO(HBL)-LUMO(Hos-N)|≤0.3eV, thereby reducing the energy level gap between the hole blocking layer 16 and the electronic host material, which is beneficial to the transmission of electrons. For example, |LUMO(HBL)-LUMO(Hos-N)|=0, and for another example, 0<|LUMO(HBL)-LUMO(Hos-N)|≤0.1eV, or, 0.1<|LUMO(HBL)-LUMO(Hos-N)|≤0.2eV, or, 0.2<|LUMO(HBL)-LUMO(Hos-N)|≤0.3eV.

[0225] In some embodiments, HOMO(HBL)-HOMO(Host-N)≥0.3 eV, which is beneficial for the hole blocking layer 16 to block holes. LUMO(EBL)-LUMO(Host)≥0.3 eV.

[0226] In some embodiments, the absolute value of the difference between the molecular weight of the hole-type host material and the molecular weight of the electronic-type host material is less than or equal to 300, thereby ensuring that the evaporation temperatures of the hole-type host material and the electronic-type host material are slightly different, preventing phase separation during the evaporation process of the light-emitting layer 15.

[0227] In one example, the molecular weights of the hole-type host material and the electron-type host material are both greater than or equal to 600, and the molecular weight of the guest material is between 700 and 1500.

[0228] In some embodiments, the emission wavelength λ of the hole-type host material is P The emission wavelength λ of the electronic host material is between 380nm and 430nm. N Between 420nm and 480nm, the emission wavelength of the exciplex is λe, where λe-λ P ≥20nm,λe-λ N ≥20nm.

[0229] In some embodiments, the thickness of the first sub-blocking layer 141 is greater than the thickness of the second sub-blocking layer 142, and the mobility of the first sub-blocking layer is greater than the mobility of the second sub-blocking layer 142, thereby facilitating the reduction of the voltage of the light-emitting device. For example, the thickness of the first sub-blocking layer 141 is between 100 angstroms and 150 angstroms, and the thickness of the second sub-blocking layer 142 is between 20 angstroms and 100 angstroms.

[0230] In some embodiments, the mobility of the hole blocking layer 16 is about 10 -7 ~10 -9 cm 2 V -1 s -1 @5000V 1 / 2 / m 1 / 2 The mobility of the electron transport layer 17 is between 10 -5 ~10 -7 cm 2 V -1 s -1 @5000V 1 / 2 / m 1 / 2 The mobility of the hole transport layer 13 is between 10 -4 ~10 -6 cm 2 V -1 s -1 @5000V 1 / 2 / m 1 / 2 The mobility of the electron blocking layer 14 is between 10 -4 ~10 -7 cm 2 V -1 s -1 @5000V 1 / 2 / m 1 / 2 This can make the mobility of each film layer more matched, which is beneficial to adjust the exciton recombination area in the light-emitting layer 15, thereby improving the light-emitting effect.

[0231] In some embodiments, the triplet energy level of the light emitting layer 16 is less than the triplet energy level of any of the second sub-blocking layer 142 and the hole blocking layer 16 , preventing the excitons in the light emitting layer 16 from leaking out.

[0232] In some embodiments, the light-emitting layer 15 includes not only a host material and a guest material, but also a dopant, wherein the dopant is capable of emitting light with a wavelength between 600 and 650 nm to improve the quantum yield of the light-emitting layer 15; the light-emitting peak of the light-emitting layer 15 is between 600 and 650 nm, ensuring that the light of the light-emitting layer 15 has maximum brightness.

[0233] The preparation process of the light-emitting device is as follows:

[0234] S1. Form a first electrode 11 on a base substrate. The material of the first electrode 11 is, for example, indium tin oxide. Then, the base substrate formed with the first electrode 11 is ultrasonically treated in a cleaning agent, rinsed in deionized water, and then ultrasonically degreased in an acetone-ethanol mixed solvent, and baked in a clean environment until the water is completely removed. The material of the first electrode 11 is ITO.

[0235] S2, placing the base substrate with the first electrode 11 in a vacuum chamber, evacuating the vacuum to 1×10-5-1×10-6, and vacuum-depositing a hole injection layer 12 on the first electrode 11 with a thickness of 10 nm.

[0236] S3 . Vapor-deposit a hole transport layer 13 on the hole injection layer 12 , with a thickness of 100 nm.

[0237] S4. Vacuum-deposit an electron blocking layer 14 on the hole transport layer 13. The electron blocking layer 14 includes, for example, a first sub-blocking layer 141 and a second sub-blocking layer 142. The thickness of the first sub-blocking layer 141 is 42 nm, and the thickness of the second sub-blocking layer 142 is 43 nm.

[0238] S5. Vacuum-evaporate the light-emitting layer 15 on the electron blocking layer 14. The light-emitting layer 15 includes a host material and a guest material. The multi-source co-evaporation method can be used during the evaporation. The weight ratio of the host material to the guest material is 98:2. The thickness of the light-emitting layer 15 is 45 nm.

[0239] S6. Vacuum-deposit a hole blocking layer 16 on the light-emitting layer 15 with a thickness of 5 nm.

[0240] S7 . Vacuum-evaporate the electron transport layer 17 on the hole blocking layer 16 to a thickness of 30 nm.

[0241] S8. Vacuum-evaporate Yb with a thickness of 1 nm on the electron transport layer 17 to form the electron injection layer 18 with a thickness of 1 nm.

[0242] S9. Evaporate the second electrode 19 on the electron injection layer 18. The second electrode 19 may be a Mg / Ag alloy layer. The ratio of Mg to Ag content is, for example, 1:9. The thickness of the second electrode 19 is 100 nm.

[0243] The performance tests of the light-emitting devices of different examples are carried out below, wherein the examples to be tested include Examples 1 to 30 and Comparative Examples 1 to 14. Tables 9 and 10 give the compounds used in the film layers in each example, wherein the material of the first electrode 11 in each example is indium tin oxide, the material of the second electrode 19 is Mg / Ag alloy, and the hole injection layer 12 is HT-1 and PD (structural formula as follows). The hole transport layer 13 uses compound HT-1 (structural formula as follows), the hole blocking layer 16 uses compound HBL-1, the electron transport layer 17 uses compound ET-1, and the electron injection layer 18 uses Yb. The materials of the remaining film layers are specifically referred to in the table. Among them, the electronic-type main material in the light-emitting layer in Examples 1 to 30 uses the compound provided by the present disclosure, the electronic-type main material in the light-emitting layer in Comparative Examples 1 to 14 is selected from the following compounds RH-N1 to RH-N12, the hole-type main material of the light-emitting layer in each example includes the following compound RH-P; the guest material of the light-emitting layer in each example includes the following compound RD.

[0244]

[0245]

[0246]

[0247] Table 9

[0248]

[0249]

[0250] Table 10

[0251]

[0252]

[0253] The driving voltage and luminous efficiency of the light-emitting device in each example were measured at a fixed current density. The data results of the driving voltage, luminous efficiency and life of each example are shown in Table 11.

[0254] Table 11

[0255]

[0256]

[0257] By comparison, it can be seen that the compounds disclosed in the present invention have better rigid structures, reduced split energy levels, and reduced non-radiative transitions, thereby improving the efficiency of the device.

[0258] By comparison, it can be seen that the compound disclosed in the present invention has a better rigid structure. The more rigid structure enables the compound to have a higher glass transition temperature, improves the film-forming property and thermal stability of the compound, and further improves the luminescence life and operational stability of the device.

[0259] By comparison, it can be seen that heteroatoms (O, S, N) are introduced into the molecules of the compounds disclosed in the present invention. The heteroatoms in the molecules make the material have greater polarity, which will improve the interface energy level between the material and the adjacent functional layer, thereby improving the injection characteristics of the material, further strengthening the interaction with the adjacent functional layer, and reducing the operating voltage of the device.

[0260] The nitrogen-containing compounds provided by the present disclosure include triazine structure, G structure and Het structure. By adjusting the connection positions among the three, the electron clouds of different compounds are different, and the energy level and mobility of the material can be properly adjusted to match the requirements of different devices.

[0261] When the compound disclosed in the present invention is combined with a hole-type material to form an excited radical complex and used as the main material of the light-emitting layer 15, the target compound has a higher electron mobility, which helps to achieve a balance between electrons and holes in the light-emitting layer 15, broadens the recombination area of ​​electrons and holes in the light-emitting layer 15, improves the luminous efficiency of electroluminescence, reduces the driving voltage of organic electroluminescence, and increases the life of the device.

[0262] The compounds disclosed in the present invention are more suitable as electronic host materials in the mixed host of organic electroluminescent devices, and are particularly suitable for electronic host materials for red light devices. When the nitrogen-containing compounds disclosed in the present invention are used as the light-emitting layer 15 material of the organic electroluminescent device, the electronic transmission performance of the device will be effectively improved, and the luminous efficiency and service life of the device will be improved.

[0263] The present disclosure also provides a display substrate, comprising the light emitting device in the above embodiment. In one example, the display substrate comprises a plurality of light emitting devices, and the plurality of light emitting devices comprises, for example, a red light emitting device, a green light emitting device and a blue light emitting device.

[0264] In a red light-emitting device, the light-emitting layer may include a phosphorescent host and a red phosphorescent dopant; in a green light-emitting device, the light-emitting layer may include a phosphorescent host and a green phosphorescent dopant; or include a fluorescent host and a fluorescent dopant; a blue light-emitting layer may use a blue phosphorescent host material and a blue phosphorescent dopant, or may use a blue fluorescent host material and a blue fluorescent dopant. Each host material (such as a red phosphorescent host material or a green fluorescent host material) may include one material or a mixture of two or more materials.

[0265] For example, the host material of the blue light-emitting layer can be selected from anthracene derivatives ADN, MADN, etc.; the guest material can be pyrene derivatives, fluorene derivatives, perylene derivatives, styrylamine derivatives, metal complexes, etc., such as TBPe, BDAVBi, DPAVBi, FIrpic, etc. The host material of the green light-emitting layer can be selected from coumarin dyes, quinacrine copper derivatives, polycyclic aromatic hydrocarbons, diamine anthracene derivatives, carbazole derivatives, such as DMQA, BA-NPB, Alq3, etc., and the guest material can be a metal complex, such as Ir(ppy)3, Ir(ppy)2(acac), etc. The host material of the red light-emitting layer is as described above, and the guest material can be a metal complex, such as Ir(piq)2(acac), PtOEP, Ir(btp)2(acac), etc.

[0266] Figure 7 Schematic diagram of a display substrate provided in some embodiments of the present disclosure, such as Figure 7As shown, the display substrate includes a driving circuit layer 20 disposed on a base substrate 10, a light emitting structure layer 30 disposed on the driving circuit layer 20, and an encapsulation layer 40 disposed on the light emitting structure layer 30. In some possible implementations, the display substrate may include other film layers, which are not limited in the present disclosure.

[0267] The driving circuit layer 20 may include transistors and storage capacitors constituting pixel circuits. Figure 7Only one transistor and one storage capacitor in each pixel circuit are shown, and the transistor includes an active layer 202, a gate electrode 201, a source electrode 203, and a drain electrode 204. In some possible implementations, the driving circuit layer 20 of each sub-pixel may include: a buffer layer BFL disposed on the base substrate 10, an active layer 202 disposed on the buffer layer BFL, a first gate insulating layer GI1 covering the active layer 202, a gate electrode 201 and a first capacitor electrode 205 disposed on the first gate insulating layer GI1, a second gate insulating layer GI2 covering the gate electrode 201 and the first capacitor electrode 205, a second capacitor electrode 206 disposed on the second gate insulating layer GI2, an interlayer insulating layer ILD covering the second capacitor electrode 206, a via hole being provided on the interlayer insulating layer ILD, and the via hole exposing the active layer 202. The source electrode 203 and the drain electrode 204 are disposed on the interlayer insulating layer ILD, and the source electrode 203 and the drain electrode 204 are connected to the active layer 202 through the via holes, respectively. The flat layer PLN is located on the side of the source electrode 203 and the drain electrode 204 away from the substrate 10. The first capacitor electrode 205 and the second capacitor electrode 206 form a storage capacitor. In some possible implementations, the buffer layer BFL, the first gate insulating layer GI1, the second gate insulating layer GI2 and the interlayer insulating layer ILD can be made of any one or more of silicon oxide (SiOx), silicon nitride (SiNx) and silicon oxynitride (SiON), and can be a single layer, a multilayer or a composite layer. The gate electrode 201, the source electrode 203, the drain electrode 204, the first capacitor electrode 205 and the second capacitor electrode 206 can be made of metal materials, such as any one or more of silver (Ag), copper (Cu), aluminum (Al), titanium (Ti) and molybdenum (Mo), or alloy materials of the above metals, such as aluminum neodymium alloy (AlNd) or molybdenum niobium alloy (MoNb), and can be a single layer structure, or a multilayer composite structure, such as Ti / Al / Ti, etc. The active layer 202 may be made of amorphous indium gallium zinc oxide (a-IGZO), zinc oxynitride (ZnON), indium zinc tin oxide (IZTO), amorphous silicon (a-Si), polycrystalline silicon (p-Si), sexithiophene or polythiophene, and the like, that is, the present disclosure is applicable to transistors manufactured based on oxide technology, silicon technology or organic technology. The active layer 202 based on oxide technology may be made of oxides containing indium and tin, oxides containing tungsten and indium, oxides containing tungsten, indium and zinc, oxides containing titanium and indium, oxides containing titanium, indium and tin, oxides containing indium and zinc, oxides containing silicon, indium and tin, oxides containing indium, gallium and zinc, and the like.

[0268] The light emitting structure layer 30 includes a pixel defining layer PDL and a plurality of light emitting devices. The pixel defining layer PDL has a plurality of pixel openings. The light emitting devices are located in the pixel openings. Figure 7Only the first electrode 11, the light-emitting layer 15 and the second electrode 19 of the light-emitting device are schematically shown.

[0269] In one example, a light extraction layer (not shown) may be further provided on the side of the second electrode 19 of the light emitting device away from the base substrate 10, and the thickness of the light extraction layer may be 60-100 nm. The material of the light extraction layer includes aromatic heterocyclic organic compounds, including triarylamines, cyclic ureas, acyl structures, dibenzothiophenes, dibenzofurans, carbazoles, etc. By providing a light extraction layer, the light extraction efficiency of the light emitting device can be improved.

[0270] The encapsulation layer 40 may include a first encapsulation layer 401, a second encapsulation layer 402 and a third encapsulation layer 403 stacked together. The first encapsulation layer 401 and the third encapsulation layer 403 may be made of inorganic materials, and the second encapsulation layer 402 may be made of organic materials. The second encapsulation layer 402 is arranged between the first encapsulation layer 401 and the third encapsulation layer 403 to ensure that external water vapor cannot enter the light-emitting structure layer 30.

[0271] The present disclosure also provides a display device, comprising the display substrate in the above embodiment.

[0272] The display device may include any device or product having a display function. For example, the display device may be a smart phone, a mobile phone, an e-book reader, a desktop computer (PC), a laptop PC, a netbook PC, a personal digital assistant (PDA), a portable multimedia player (PMP), a digital audio player, a mobile medical device, a camera, a wearable device (such as a head-mounted device, an electronic garment, an electronic bracelet, an electronic necklace, an electronic accessory, an electronic tattoo, or a smart watch), a television, etc.

[0273] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present disclosure, but the present disclosure is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and substance of the present disclosure, and these modifications and improvements are also considered to be within the scope of protection of the present disclosure.

Claims

1. A compound, wherein The structural formula of the compound is shown in general formula (1): Wherein, the structural formula of G is as shown in the general formula (2), wherein the two wavy lines respectively represent the positions where G is connected to the triazine structure and L in the general formula (1); the electron cloud of the LUMO energy level of the compound accounts for 3% to 60% on G; X is O, S, C(R1)(R2), N(R3); A is phenyl or naphthyl; R1, R2, and R3 are the same as or different from each other, and are each independently selected from any one of hydrogen, deuterium, a halogen atom, a cyano group, a nitro group, a hydroxyl group, a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C2-C20 alkenyl group, a substituted or unsubstituted C2-C18 alkynyl group, a substituted or unsubstituted C3-C18 cycloalkyl group, a substituted or unsubstituted C1-C18 alkoxy group, a substituted or unsubstituted C6-C60 aryl group, a substituted or unsubstituted 5-60-membered heteroaryl group, and a substituted or unsubstituted 5-18-membered heterocyclyl group; Ar1 and Ar2 represent substituted or unsubstituted C6-C60 aryl, or substituted or unsubstituted 6- to 60-heteroaryl; L is a direct bond, alkyl, cycloalkyl, heterocycloalkyl, alkenyl, alkynyl, aryl and heteroaryl may be further substituted independently by one or more groups selected from the group consisting of deuterium, (C1-C30)alkyl, halo(C1-C30)alkyl, halogen, cyano, (C3-C30)cycloalkyl, 5-membered to 7-membered heterocycloalkyl, (C2-C30)alkenyl, (C2-C30)alkynyl, (C6-C30)aryl, (C1-C30)alkoxy, (C6-C30)aryloxy, (C2-C30)heteroaryl, (C6-C30)aryl-substituted (C2-C30)heteroaryl, (C6-C30)aryl(C1-C30)alkyl, (C1-C30) )alkyl(C6-C30)aryl, (C6-C30)arylthio, mono- or di-(C1-C30)alkylamino, mono- or di-(C6-C30)arylamino, (C1-C30)alkyl(C6-C30)arylamino, di-(C6-C30)arylboryl, di-(C1-C30)alkylboryl, (C1-C30)alkyl(C6-C30)arylboryl, tri-(C1-C30)alkylsilyl, di-(C1-C30)alkyl(C6-C30)arylsilyl, (C1-C30)alkyldi-(C6-C30)arylsilyl, tri-(C6-C30)arylsilyl, N-carbazolyl, carboxyl, nitro and hydroxyl; The structural formula of Het is one of the following general formula (2-1), general formula (2-2), general formula (2-3), and general formula (2-4): X1, X2, X3, and X4 represent S or O, C, or N, A1 to A10 each independently represent CH, C(Ra), or N, B1 to B10 each independently represent CH, C(Rb), or N, E1 to E10 each independently represent CH, C(Rc), or N, and Y1 to Y8 each independently represent CH, C(Rc), or N; At least one of A1 to A10 in the general formula (2-1) is N, at least one of B1 to B10 in the general formula (2-2) is N, at least one of E1 to E10 in the general formula (2-3) is N, and at least one of Y1 to Y8 in the general formula (2-4) is N; Ra, Rb, and Rc are the same as or different from each other and are independently selected from hydrogen, deuterium, a halogen atom, a hydroxyl group, a cyano group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 ring carbon atoms, a substituted or unsubstituted arylthio group having 6 to 30 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, and a substituted or unsubstituted heterocyclic group having 5 to 30 ring atoms.

2. The compound according to claim 1, wherein When a plurality of Ra, a plurality of Rb, and a plurality of Rc are present, adjacent Ra, adjacent Rb, and adjacent Rc are independently bonded to each other to form a ring structure.

3. The compound according to claim 1, wherein The structure represented by the general formula (1) is selected from any one of the following structural formulas:

4. The compound according to any one of claims 1 to 3, wherein The LUMO energy level of the compound is between 1.8 eV and 2.3 eV.

5. The compound according to any one of claims 1 to 3, wherein The reorganization energy of the compound is less than or equal to 0.4 eV.

6. The compound according to any one of claims 1 to 3, wherein The triplet energy level of the compound is between 2.0 eV and 2.6 eV.

7. A light emitting device, wherein: The invention comprises a first electrode, a light-emitting layer and a second electrode which are stacked in sequence, wherein the light-emitting layer comprises a first material, and the first material comprises the compound according to any one of claims 1 to 6.

8. The light emitting device according to claim 7, wherein: The light-emitting layer includes a host material and a guest material, the host material includes an electronic host material and a hole host material, the electronic host material includes the first material, and the structure of the hole host material is as follows: The electron-type host material forms an exciplex with the hole-type host material.

9. The light emitting device according to claim 8, wherein: The HOMO energy level of the hole-type host material is between 5.0 eV and 5.4 eV.

10. The light emitting device according to claim 8, wherein: The weight ratio of the hole-type host material to the electron-type host material is between 1:9 and 9:

1.

11. The light emitting device according to claim 8, wherein: The weight percentage of the guest material in the light-emitting layer is between 1 wt % and 3 wt %.

12. The light emitting device according to claim 8, wherein: The light-emitting device also includes: a hole injection layer, a hole transport layer and an electron blocking layer located between the first electrode and the light-emitting layer and arranged in sequence in a direction close to the light-emitting layer, and the absolute value of the difference between the HOMO energy level of the electron blocking layer and the HOMO energy level of the hole-type host material is less than or equal to 0.3eV.

13. The light emitting device according to claim 8, wherein: The light-emitting device also includes: an electron injection layer, an electron transport layer and a hole blocking layer located between the second electrode and the light-emitting layer and arranged in sequence in a direction close to the light-emitting layer, and the absolute value of the difference between the LUMO energy level of the hole blocking layer and the LUMO energy level of the electronic host material is less than or equal to 0.3eV.

14. The light emitting device according to claim 8, wherein: The light-emitting device further comprises: an electron injection layer, an electron transport layer and a hole blocking layer which are located between the second electrode and the light-emitting layer and are sequentially arranged in a direction close to the light-emitting layer, wherein the HOMO energy level of the hole blocking layer is greater than the HOMO energy level of the electronic host material, and the difference between the two is greater than or equal to 0.3 eV; The light-emitting device also includes: a hole injection layer, a hole transport layer and an electron blocking layer located between the first electrode and the light-emitting layer and arranged in sequence along a direction close to the light-emitting layer, the LUMO energy level of the electron blocking layer is greater than the LUMO energy level of the hole-type host material, and the difference between the two is greater than or equal to 0.3eV.

15. The light emitting device according to claim 8, wherein: The absolute value of the difference between the molecular weight of the hole-type host material and the molecular weight of the electron-type host material is less than or equal to 300.

16. The light emitting device according to claim 15, wherein: The molecular weight of the hole-type host material and the molecular weight of the electron-type host material are both greater than or equal to 600, and the molecular weight of the guest material is between 700 and 1500.

17. The light emitting device according to claim 8, wherein: The distance between the electron cloud of the HOMO energy level of the hole-type host material and the electron cloud of the LUMO energy level of the electron-type host material is between 3 and 5 angstroms.

18. The light emitting device according to claim 8, wherein: The emission wavelength λ of the hole-type host material P The emission wavelength λ of the electronic host material is between 380nm and 430nm. N The emission wavelength of the exciplex is λe between 420nm and 480nm, wherein: λe-λ P ≥20nm,λe-λ N ≥20nm.

19. The light emitting device according to claim 7, wherein: The light-emitting device further includes: a hole injection layer, a hole transport layer, and an electron blocking layer located between the first electrode and the light-emitting layer and sequentially arranged in a direction close to the light-emitting layer, the electron blocking layer includes a first sub-blocking layer and a second sub-blocking layer sequentially arranged in a direction close to the light-emitting layer, the thickness of the first sub-blocking layer is greater than the thickness of the second sub-blocking layer, and the mobility of the first sub-blocking layer is greater than the mobility of the second sub-blocking layer.

20. The light emitting device according to claim 7, wherein: The light emitting device further comprises: a hole injection layer, a hole transport layer and an electron blocking layer which are located between the first electrode and the light emitting layer and are sequentially arranged in a direction close to the light emitting layer, and an electron injection layer, an electron transport layer and a hole blocking layer which are located between the second electrode and the light emitting layer and are sequentially arranged in a direction close to the light emitting layer; The mobility of the hole blocking layer is 10 -7 ~10 -9 cm 2 V -1 s -1 @5000V 1 / 2 / m 1 / 2 between, The mobility of the electron transport layer is 10 -5 ~10 -7 cm 2 V -1 s -1 @5000V 1 / 2 / m 1 / 2 between, The mobility of the hole transport layer is 10 -4 ~10 -6 cm 2 V -1 s -1 @5000V 1 / 2 / m 1 / 2 between, The mobility of the electron blocking layer is 10 -4 ~10 -7 cm 2 V -1 s -1 @5000V 1 / 2 / m 1 / 2 between.

21. The light emitting device according to claim 7, wherein: The light emitting device further comprises: a hole injection layer, a hole transport layer and an electron blocking layer which are disposed in sequence between the first electrode and the light emitting layer and in a direction close to the light emitting layer, and an electron injection layer, an electron transport layer and a hole blocking layer which are disposed in sequence between the second electrode and the light emitting layer and in a direction close to the light emitting layer; the electron blocking layer comprises a first sub-blocking layer and a second sub-blocking layer which are disposed in sequence in a direction close to the light emitting layer; The triplet energy level of the light emitting layer is lower than the triplet energy level of any one of the second sub-blocking layer and the hole blocking layer.

22. The light emitting device according to any one of claims 7 to 21, wherein: The light-emitting layer is used to emit red light; The light-emitting layer further comprises a dopant, and the dopant is used to emit light with a wavelength between 600 and 650 nm; the light-emitting peak of the light-emitting layer is between 600 and 650 nm.

23. A display substrate, wherein: A light emitting device comprising the light emitting device according to any one of claims 7 to 22.

24. A display device, wherein: Includes the display substrate as claimed in claim 23.

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