Heterogeneous tta-uc system for single-emitting layer organic electroluminescent device, host compound containing phenanthrobenzofuran structure and application

Abstract

The application relates to the technical field of organic electroluminescent materials, and particularly discloses a hetero TTA-UC system for a single light-emitting layer organic electroluminescent device, a host compound containing phenanthropenobenzofuran structure and application. The hetero TTA-UC system comprises a triplet donor (BHT), a quenching agent (BHA) and a doped light-emitting material (BD); the quenching agent is a multi-anthracene compound; and T 1‑BHT >T 1‑BHA ,S 1‑BHT >S 1‑BD ,S 1‑BHA >S 1‑BD ,2×T 1‑BHA >S 1‑BHA . The energy level of the hetero TTA-UC system is limited, and the host compound containing the phenanthropenobenzofuran structure is used as the quenching agent in the single light-emitting layer organic electroluminescent device, so that the triplet exciton transfer can be improved, the exciton concentration can be reduced, the energy quenching can be effectively prevented, the luminous efficiency of the device is improved, and the service life of the device is prolonged.

Description

Technical Field

[0001] This invention relates to the field of organic electroluminescent materials technology, and in particular to a heterogeneous TTA-UC system for single-emitting-layer organic electroluminescent devices, a host compound containing a phenanthrene-benzofuran structure, and its applications. Background Technology

[0002] Organic light-emitting diodes (OLEDs) have become one of the most competitive display and lighting technologies due to their high efficiency, lightweight design, high color saturation, near 180° viewing angle, ultra-fast response speed, and potential for achieving pure black displays. In current mass-produced blue OLED devices, the emitting layer generally employs a host-guest doping system, utilizing a blend of host and guest dopants to achieve electroluminescence. Blue fluorescent devices often use anthracene-based compounds as the host material. However, existing anthracene-based host materials still require improvement in device performance indicators such as efficiency and driving voltage. To overcome the limitations of spin statistics theory and improve the utilization rate of triplet excitons, an effective strategy is to enhance the triplet-triplet annihilation (TTA) upconversion efficiency of the material. By introducing additional anthracene fragments into the anthracene host molecule to construct bi-anthracene compounds, an intramolecular TTA pathway can be introduced, thereby improving device performance.

[0003] Nevertheless, the development of bis-anthracene compounds faces significant challenges. Compared to mono-anthracene molecules, bis-anthracene molecules typically have larger intermolecular distances, leading to slower carrier transport and consequently decreased carrier mobility, affecting device efficiency. Therefore, developing bis-anthracene host materials that combine high hole / electron mobility with efficient TTA (transfer-to-charge) properties remains a current research challenge.

[0004] Furthermore, while blue OLED technology based on the TTA mechanism has made significant progress and become the mainstream of current mass production systems, inherent physical bottlenecks still limit further improvements in its efficiency. Specifically, existing TTA emitting layers rely on high triplet exciton density to achieve efficient energy upconversion (TTA-UC). At high exciton densities, although the upconversion efficiency is high, it easily induces non-radiative decay processes such as triplet-polaron annihilation (TPA), leading to a severe roll-off in device efficiency. Conversely, if the exciton concentration is reduced to suppress efficiency roll-off, the TTA upconversion efficiency will drop sharply, also failing to achieve high-performance devices. This contradiction between exciton concentration, upconversion efficiency, and efficiency roll-off limits the performance upper limit of traditional TTA devices. At the same time, ideal TTA materials require strictly matched first singlet level (S1), first triplet level (T1), and second triplet level (T2) to meet the thermodynamic requirements of energy transfer and annihilation. However, for the same compound structure, its molecular skeleton determines the energy level distribution, making it difficult to independently and precisely control the parameters of each energy level without compromising other photoelectric properties. This further increases the difficulty of developing high-performance TTA materials.

[0005] Therefore, if the performance bottlenecks of existing TTA devices (such as low carrier mobility, exciton management contradictions, and difficulty in energy level control) can be overcome by optimizing the energy level arrangement and energy transfer path within the emitting layer, it will have significant practical implications and broad application prospects for promoting the performance improvement of single-emitting-layer OLED devices. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides a heterogeneous TTA-UC system for single-emitting-layer organic electroluminescent devices, a host compound containing a phenanthrene-benzofuran structure, and its applications. By confining the energy levels of the heterogeneous TTA-UC system, triplet exciton transfer can be improved, exciton concentration can be reduced, and energy quenching can be effectively prevented, thereby improving the luminous efficiency and extending the device's lifetime.

[0007] To solve the above-mentioned technical problems, the technical solution provided by the present invention is as follows: In a first aspect, the present invention provides a heterogeneous TTA-UC system for a single-emitting-layer organic electroluminescent device, comprising a triplet donor (BHT), an annihilation agent (BHA), and a doped luminescent material (BD); wherein the annihilation agent is a polyanthracene compound; The first singlet state energy level of the triplet donor is S. 1-BHT The first triplet energy level is T 1-BHT The first singlet state energy level of the annihilator is S. 1-BHA The first triplet energy level is T 1-BHA The first singlet energy level of the doped luminescent material is S. 1-BDAnd T 1-BHT >T 1-BHA S 1-BHT >S 1-BD S 1-BHA >S 1-BD 2×T 1-BHA >S 1-BHA .

[0008] This invention provides a limit of 2×T 1-BHA >S 1-BHA This ensures that triplet excitons are efficiently converted into singlet states through the TTA channel, rather than undergoing nonradiative loss.

[0009] Preferably, 0.1 eV < T 1-BHT -T 1-BHA <0.5eV.

[0010] Further preferred, 0.1 eV < T 1-BHT -T 1-BHA <0.3eV.

[0011] Preferably, the first triplet energy level of the doped luminescent material is T. 1-BD T 1-BD >T 1-BHA .

[0012] The present invention, through the above-mentioned limitations, can effectively prevent triplet energy backflow.

[0013] Further preferred, T 1-BD >T 1-BHT >T 1-BHA .

[0014] Preferred, S 1-BHT >S 1-BHA >S 1-BD .

[0015] Further preferred, S 1-BHT -S 1-BHA <0.6eV.

[0016] More preferably, S 1-BHT -S 1-BHA <0.3eV.

[0017] Preferred, 2×T 1-BHT >S 1-BHT .

[0018] Preferably, the first quintet energy level of the annihilation agent is Q. 1-BHA And Q 1-BHA >2×T 1-BHA >S 1-BHA .

[0019] Preferably, the first quintet energy level of the triplet donor is Q. 1-BHT And Q 1-BHT >2×T 1-BHT >S 1-BHT .

[0020] Preferably, the triplet donor is selected from at least one of the compounds shown in formulas I-1 to I-6. I-1 I-2 I-3 I-4 I-5 I-6 In formulas I-1~I-6, Ar T11 Ar T51 Ar T61 Ar T62 It represents substituted or unsubstituted aryl groups with 6 to 60 carbon atoms, and substituted or unsubstituted heteroaryl groups with 3 to 60 carbon atoms; Ar T12 Ar T13 Ar T14 Each of these groups independently represents hydrogen, an alkyl group with 1 to 15 carbon atoms, an alkoxy group with 1 to 15 carbon atoms, a substituted or unsubstituted aryl group with 6 to 30 carbon atoms, or a substituted or unsubstituted heteroaryl group with 3 to 30 carbon atoms, and Ar T13 Ar T14 At least one of them is H; Ar T21 Ar T22 Ar T23 Ar T24 Ar T31 Ar T32 Ar T41 Ar T42 Each is independently selected from hydrogen, substituted or unsubstituted aryl groups with 6 to 60 carbon atoms, and substituted or unsubstituted heteroaryl groups with 3 to 60 carbon atoms; and Ar T21 Ar T22 Ar T23 Ar T24 Not all of it is hydrogen, Ar T31 Ar T32 Not all of it is hydrogen, Ar T41 Ar T42 Not all of it is hydrogen; Ar T52 Ar T53 Ar T54 Ar T63 ArT64 Each can independently represent hydrogen, substituted or unsubstituted aryl groups with 6 to 30 carbon atoms, or substituted or unsubstituted heteroaryl groups with 3 to 30 carbon atoms; L represents substituted or unsubstituted aryl groups with 6 to 30 carbon atoms, and substituted or unsubstituted heteroaryl groups with 3 to 30 carbon atoms; Any hydrogen atom in formulas I-1 to I-6 can be independently replaced by deuterium.

[0021] More preferably, in formulas I-1 to I-6, the aryl group includes phenyl, naphthyl, biphenyl, phenanthryl, anthraceneyl, pyreneyl, or fluoreneyl.

[0022] More preferably, in formulas I-1 to I-6, the heteroaryl group includes benzofuranyl, dibenzofuranyl, naphthobenzofuranyl, phenanthro[4,5-bcd]furanyl, phenanthrobenzofuranyl, benzothiophene, dibenzothiophene, carbazoyl, pyridyl, pyrimidinyl, pyrazinyl, triazinyl, N-phenylindolyl, quinolinyl, or isoquinolinyl.

[0023] More preferably, in formulas I-1 to I-6, the heteroaryl group is selected from dibenzofuranyl, naphthobenzofuranyl, phenanthrobenzofuranyl or phenanthro[4,5-bcd]furanyl.

[0024] More preferably, in formulas I-1 to I-6, the alkyl group includes a chain alkyl group or a cycloalkyl group.

[0025] More preferably, in formulas I-1 to I-6, the alkoxy group includes chain alkoxy or cycloalkoxy.

[0026] More preferably, in formulas I-1 to I-6, the arylene group includes phenylene, naphthylene, biphenylene, phenanthrene, anthracene, pyrene, or fluorene.

[0027] More preferably, in formulas I-1 to I-6, the heteroaryl group includes dibenzofuranyl, naphthobenzofuranyl, phenanthrenebenzofuranyl, or phenanthrene[4,5-bcd]furanyl.

[0028] Further preferred, when Ar in equations I-1 to I-6 T11 ~Ar T14 Ar T21 ~Ar T24 Ar T31 Ar T32 Ar T41 Ar T42 Ar T51 ~Ar T54 Ar T61 ~Ar T64When L contains a substituent, the substituent includes deuterium, alkyl with 1 to 12 carbon atoms, alkoxy with 1 to 12 carbon atoms, substituted or unsubstituted aryl with 6 to 20 carbon atoms, and substituted or unsubstituted heteroaryl with 3 to 20 carbon atoms.

[0029] More preferably, when Ar in equations I-1 to I-6 T11 ~Ar T14 Ar T21 ~Ar T24 Ar T31 Ar T32 Ar T41 Ar T42 Ar T51 ~Ar T54 Ar T61 ~Ar T64 When L contains a substituent, the substituent includes deuterium, phenyl, naphthyl, biphenyl, phenanthryl, anthraceneyl, pyrene, dibenzofuranyl, naphthobenzofuranyl, or phenanthrenebenzofuranyl.

[0030] It should be noted that in this invention, the naphthobenzofuranyl group refers to the following structure, and the linkage site is optional during substitution: ; phenanthrenebenzofuranyl refers to the following structures, and the linkage site is optional during substitution: The structure of the phenanthroline [4,5-bcd]furanyl group is as follows: The connection site can be chosen arbitrarily when replacing.

[0031] More preferably, the triplet donor is selected from at least one of the following structural formulas. In the above structural formula, any one of the hydrogen atoms can be independently replaced by deuterium.

[0032] Preferably, the annihilating agent is a dianthracene compound, a trianthracene compound, or a tetraanthracene compound.

[0033] More preferably, the annihilating agent is selected from compounds shown in formulas II-1 to II-2. II-1 II-2 In equations II-1 to II-2, Ar A1Ar A2 Ar A3 Ar A4 Ar A5 Ar A6 Each can be independently represented as an aryl group with 6 to 60 substituted or unsubstituted carbon atoms, or a heteroaryl group with 3 to 60 substituted or unsubstituted carbon atoms; L1, L2, L4, and L5 each independently represent a single bond, phenylene, biphenylene, or naphthylene; L0 and L3 are selected from single bonds, substituted or unsubstituted aryl groups with 6 to 30 carbon atoms, and substituted or unsubstituted heteroaryl groups with 3 to 30 carbon atoms; In Formula II, any hydrogen atom can be independently replaced by deuterium.

[0034] More preferably, the annihilating agent is selected from compounds represented by formula II-1 or II-3. II-1 II-3.

[0035] More preferably, in formulas II-1 to II-2, the aryl group includes phenyl, naphthyl, biphenyl, phenanthryl, anthraceneyl, or fluorenyl.

[0036] More preferably, in formulas II-1 to II-2, the heteroaryl group includes benzofuranyl, dibenzofuranyl, naphthobenzofuranyl, phenanthro[4,5-bcd]furanyl, phenanthrobenzofuranyl, benzothiophene, dibenzothiophene, carbazoyl, pyridyl, pyrimidinyl, pyrazinyl, triazinyl, N-phenylindolyl, quinolinyl, or isoquinolinyl.

[0037] More preferably, in formulas II-1 to II-2, the heteroaryl group is selected from dibenzofuranyl, naphthobenzofuranyl, phenanthrobenzofuranyl, or phenanthro[4,5-bcd]furanyl.

[0038] More preferably, in formulas II-1 to II-2, the arylene group includes phenylene, naphthylene, biphenylene, phenanthrene, anthracene, pyrene, or fluorene.

[0039] More preferably, in formulas II-1 to II-2, the heteroaryl group includes dibenzofuranyl, naphthobenzofuranyl, phenanthrenebenzofuranyl or phenanthrene[4,5-bcd]furanyl.

[0040] More preferably, when Ar in formulas II-1 to II-2 A1 Ar A2 Ar A3 Ar A4 Ar A5 Ar A6When L0 and L3 contain substituents, the substituents include deuterium, alkyl groups having 1 to 12 carbon atoms, alkoxy groups having 1 to 12 carbon atoms, substituted or unsubstituted aryl groups having 6 to 20 carbon atoms, and substituted or unsubstituted heteroaryl groups having 3 to 20 carbon atoms.

[0041] Furthermore, in formulas II-1 to II-2, Ar is preferred. A1 Ar A2 Ar A3 Ar A4 Ar A5 Ar A6 When L0 and L3 contain substituents, the substituents include deuterium, phenyl, naphthyl or biphenyl.

[0042] More preferably, in formulas II-1 to II-2, L0 and L3 are selected from single bonds, phenylene, naphthylene, dimethylfluorene, diphenylfluorene, dibenzofuranyl, naphthylbenzofuranyl or phenanthrene[4,5-bcd]furanyl, and any one of the hydrogen atoms in L0 and L3 can be independently substituted with deuterium.

[0043] Furthermore, in formulas II-1 to II-2, Ar A1 Ar A2 Ar A3 Ar A4 Ar A5 Ar A6 Each is independently selected from substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, or substituted or unsubstituted dibenzofuranyl.

[0044] More preferably, the triplet donor is selected from at least one of the following structural formulas. In the above structural formula, any one of the hydrogen atoms can be independently replaced by deuterium.

[0045] It should be noted that this invention does not impose any special limitation on the specific structure of the doped luminescent material; commonly used doped luminescent materials in the art can be used, as long as the energy level requirements are met. In some specific examples, the doped luminescent material is selected from any of the following structural formulas. .

[0046] In some more specific examples, the doped luminescent material is selected from bis-boron compounds. It should be noted that bis-boron compounds refer to compounds containing two boron atoms in their structural formula.

[0047] Preferably, the mass ratio of the triplet donor to the annihilator is (1~50):(50~1), and the mass of the doped luminescent material accounts for 0.01%~10% of the total mass of the heterogeneous TTA-UC system.

[0048] More preferably, the mass ratio of the triplet donor to the annihilation agent is (1~10):(10~1), and the mass ratio of the sum of the triplet donor and the annihilation agent to the mass of the doped luminescent material is 100:(0.5~10).

[0049] Secondly, the present invention provides a host compound containing a phenanthrene-benzofuran structure as an annihilator in the heterogeneous TTA-UC system for single-emitting-layer organic electroluminescent devices; the general structural formula of the host compound containing the phenanthrene-benzofuran structure is shown in Formula IV. IV In Equation IV, Ar A7 Ar A8 Each can be used independently to represent substituted or unsubstituted aryl groups with 6 to 30 carbon atoms, or substituted or unsubstituted heteroaryl groups with 3 to 30 carbon atoms. L7 and L8 each independently represent a single bond, phenylene, biphenylene, or naphthylene; L6 is selected from any one of the structures shown in formulas IV-1 to IV-6. IV-1 IV-2 IV-3 IV-4 IV-5 IV-6 R 101 ~R 112 R 201 ~R 212 R 301 ~R 312 R 401 ~R 412 R 501 ~R 512 R 601 ~R 612 Each of the components independently contains two single bonds, which are connected to L7 and L8 respectively, and the remaining components are independently selected from hydrogen, alkyl with 1 to 12 carbon atoms, substituted or unsubstituted aryl with 6 to 30 carbon atoms, and substituted or unsubstituted heteroaryl with 4 to 18 carbon atoms. In Formula IV, any hydrogen atom can be independently replaced by deuterium.

[0050] Preferably, in formula IV-1, R 101 R 102 R 103 R 104 R 105 It contains two single bonds.

[0051] Preferably, in formula IV-2, R 201 R 202 R 203 R 204 R 205 It contains two single bonds.

[0052] Preferably, in formula IV-3, R 301 R 302 R 303 R 304 R 305 R 306 It contains two single bonds.

[0053] Preferably, in formula IV-4, R 401 R 402 R 403 R 404 R 405 R 406 It contains two single bonds.

[0054] Preferably, in formula IV-5, R 501 R 502 R 503 R 504 R 505 R 506 It contains two single bonds, and R 501 R 502 R 503 R 504 It contains at least one single bond.

[0055] Preferably, in formula IV-6, R 601 R 602 R 603 R 604 R 605 R 606 R 607 R 608 R 609 R 610 It contains two single bonds, and R 601 R 602 R 603 R 604 It contains at least one single bond.

[0056] Preferably, in formula IV, Ar A7 Ar A8 Each can be used independently to represent a substituted or unsubstituted aryl group with 6 to 30 carbon atoms.

[0057] Further preferred, in formula IV, when Ar A7Ar A8 When a substituent is present, the substituent may be one or more, and the substituent may be selected from deuterium, alkyl groups having 1 to 10 carbon atoms, or phenyl groups.

[0058] In a further preferred embodiment, in formula IV, Ar A7 Ar A8 Each can be used independently to represent a substituted or unsubstituted phenyl, naphthyl, or biphenyl group.

[0059] More preferably, in formula IV, Ar A7 Ar A8 Each independently selected , , , or .

[0060] Furthermore, in formula IV, Ar A7 Ar A8 Both represent 1-naphthyl.

[0061] Preferably, in formula IV, L7 and L8 independently represent single bonds, , , , , , , or In L7 and L8, any one of the hydrogen atoms can be independently replaced by deuterium.

[0062] In a further preferred embodiment, in Formula IV, L7 and L8 each independently represent a single bond or a phenylene group.

[0063] More preferably, in Formula IV, L7 and L8 both represent 1,4-phenylene.

[0064] More preferably, the host compound containing the phenanthrenebenzofuran structure is selected from any one of the following structural formulas. In the above structure, any one hydrogen atom can be independently replaced by deuterium.

[0065] Thirdly, the present invention provides an organic light-emitting ink composition comprising the heterogeneous TTA-UC system for single-emitting-layer organic electroluminescent devices.

[0066] This invention applies the heterogeneous TTA-UC system to inkjet printing (IJP) devices, which can more effectively improve the TTA ratio.

[0067] Preferably, the organic light-emitting ink composition comprises the host compound containing the phenanthrenebenzofuran structure.

[0068] More preferably, the organic light-emitting ink composition further includes at least one non-halogenated aromatic solvent.

[0069] More preferably, the mass ratio of the heterogeneous TTA-UC system to the non-halogenated aromatic solvent is (1~400):1000, and even more preferably (1~200):1000.

[0070] Fourthly, the present invention provides a single-emitting-layer organic electroluminescent device, wherein the raw material of the emitting layer includes the heterogeneous TTA-UC system or the organic light-emitting ink composition.

[0071] The organic light-emitting ink composition provided by this invention can improve the overall performance of organic electroluminescent devices prepared using it, such as efficiency and lifespan, while meeting the requirements of inkjet printing processes for boiling point, viscosity, solubility and surface tension.

[0072] Preferably, the structure of the single-emitting-layer organic electroluminescent device includes an anode, a hole transport region, an emitting layer, an electron transport region, and a cathode sequentially disposed on a substrate; wherein the emitting layer is formed by inkjet printing of the organic light-emitting ink composition.

[0073] More preferably, the hole transport region includes a hole injection layer and a hole transport layer.

[0074] More preferably, the electron transport region includes an electron transport layer and an electron injection layer.

[0075] In this invention, the anode uses commonly used anode materials in the art, such as ITO, Ag, or their multilayer structures. The hole injection layer uses commonly used hole injection materials in the art, and is doped with F4TCNQ, HATCN, NDP-9, etc., or polymer materials can be used in combination with organic salt compounds for doping. The hole transport layer uses commonly used small molecule or polymer hole transport materials in the art. The light-emitting layer uses the heterogeneous TTA-UC system or organic light-emitting ink composition provided by this invention. The electron transport layer uses commonly used electron transport materials in the art. The electron injection layer uses commonly used electron injection materials in the art, such as LiQ, LiF, Yb, etc. The cathode uses commonly used materials in the art, such as metallic Al, Ag, or metal mixtures (Ag-doped Mg, Ag-doped Ca, etc.).

[0076] The present invention has the following beneficial effects: The heterogeneous TTA-UC system for single-emitting-layer organic electroluminescent devices provided by this invention constructs a single-emitting-layer structure comprising a triplet donor, an annihilator, and a doped luminescent material, and precisely defines the energy level matching relationship among the three. This facilitates the migration of triplet excitons to the unexcited triplet annihilator BHA, optimizing the intermolecular triplet energy transfer pathway. This allows triplet excitons generated on the triplet donor BHT to efficiently transfer to the annihilator molecule BHA, subsequently undergoing TTA upconversion within BHA. This overcomes the high energy loss limitation of traditional fluorescent devices, significantly improving the utilization rate of triplet excitons and ultimately achieving a significant improvement in the external quantum efficiency (EQE). Furthermore, by mixing BHT and BHA in the same luminescent layer, this invention maintains high TTA upconversion efficiency while effectively reducing the triplet exciton density on BHT due to the freer migration and transfer of triplet excitons. Thanks to this, energy quenching effects such as triplet-polaron annihilation (TPA) induced by high-concentration excitons and material degradation induced by high-energy excitons are effectively suppressed, and the energy quenching probability can be reduced by 1 to 2 orders of magnitude. This not only alleviates the efficiency roll-off problem of the device under high current density, but also greatly reduces exciton stress damage to the light-emitting layer material, thereby significantly improving the device's operating life.

[0077] The main compound containing the phenanthrenebenzofuran structure provided by this invention, when used as an annihilator in a single-emitting-layer organic electroluminescent device, exhibits the following outstanding beneficial effects. (1) The compound uses the phenanthrenebenzofuran structure as a connecting bridge between two anthracene units, forming a stable bi-anthracene structure on the molecular skeleton. This structural feature provides an additional triplet-triplet annihilation (TTA) channel (intramolecular TTA) within a single molecule, effectively increasing the upconversion efficiency of triplet excitons, thereby breaking through the limitations of spin statistics in traditional fluorescent devices and significantly improving the utilization rate of triplet excitons. (2) This invention innovatively introduces the oxygen-containing fused heterocyclic structure of phenanthrenebenzofuran as a connecting group. On the one hand, the strong electronegativity of oxygen atoms endows the molecule with a certain electron affinity potential, optimizing the LUMO+n energy level distribution of the material; on the other hand, the rigid planar oxygen heterocyclic structure enhances the π-π stacking ability between molecules, effectively reducing the intermolecular distance. The synergistic effect of the two significantly improves the electron mobility of the material, solving the problem of slow carrier transport caused by the large intermolecular distance in traditional bis-anthracene compounds, thereby further improving the luminescence efficiency of the device. (3) The bis-anthracene compound containing phenanthrenebenzofuran, as an annihilator, can well meet the strict requirements of the heterogeneous TTA-UC system for energy level matching in its S1 and T1 energy levels. Combined with the aforementioned advantages in electron transport, this material achieves efficient intramolecular TTA while ensuring efficient transport of carriers and energy, ultimately improving both device efficiency and lifetime. Detailed Implementation

[0078] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0079] Terms and Definitions In this invention, the terms "preferred," "further preferred," "more preferred," "even more preferred," and "most preferred" refer to embodiments of the invention that provide certain beneficial effects under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of this invention.

[0080] In this invention, the first singlet state energy level of the triplet donor (BHT) is S. 1-BHT The first triplet energy level is T 1-BHT The first quintet energy level is Q. 1-BHT The first singlet energy level of the annihilation agent (BHA) is S. 1-BHA The first triplet energy level is T 1-BHA The first quintet energy level is Q. 1-BHA The first singlet energy level of the doped luminescent material (BD) is S. 1-BD The first triplet energy level is T 1-BD Among them, the full name of the first singlet state energy level is the first singlet excited state energy level, the full name of the first triplet state energy level is the first triplet excited state energy level, and the full name of the first quintet state energy level is the first quintet excited state energy level.

[0081] "Deuterium" refers to the hydrogen isotope deuterium.

[0082] "Deuteration" refers to the substitution of one or more hydrogen atoms in a group by deuterium.

[0083] The asterisk (*) indicates a connection point with other atoms.

[0084] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0085] The following are specific examples. Unless otherwise specified, the solvents and reagents used in the examples can be purchased from conventional reagent suppliers, and the relevant compounds can be prepared by existing processes or conventional processes in the art.

[0086] The synthesis methods of the host material (including triplet donor and annihilator), guest material (i.e. doped luminescent material) and its corresponding intermediate compound in the embodiments of the present invention can be obtained by conventional technical means in the art.

[0087] In a specific example of the present invention, the triplet donor (BHT) is selected from BHT01 to BHT03, the annihilation agent (BHA) is selected from BHA01 to BHA16, and the doped luminescent material (BD) is selected from BD01 to BD02; the contrast annihilation agent is selected from monoanthracene compounds DBHA01 to DBHA03 (the specific structure is shown in the following formula).

[0088] BHT01 BHT02 BHT03 BHA01 BHA02 BHA03 BHA04 BHA05 BHA06 BHA07 BHA08 BHA09 BHA10 BHA11 BHA12 BHA13 BHA14 BHA15 BHA16 BD01 BD02 DBHA01 DBHA02 DBHA03 This invention does not impose any special limitations on the preparation method of the organic light-emitting ink composition. Conventional preparation methods in the art can be used to mix the host compound, guest compound and non-halogenated aromatic solvent evenly.

[0089] The fabrication methods of the organic electroluminescent devices and the deposition methods of each functional layer in the embodiments of the present invention are conventional methods in the art, and will not be described in detail here.

[0090] Synthesis example 1 This synthetic example provides a method for synthesizing a host compound (denoted as BHA03), the chemical equation of which is shown below.

[0091] Under nitrogen protection, 50 mL of toluene, 12 mL of ethanol, and 10 mL of water were added to a Schlenk flask. Then, intermediates 03-a (8.50 g), 03-b (4.26 g), potassium carbonate (7.56 g), and tetra-triphenylphosphine palladium (2.31 g) were added. The mixture was heated to 90 °C and reacted for 12 h. After cooling to room temperature, the mixture was filtered. The filter cake was dissolved in toluene and filtered to remove the solid insolubles. Recrystallization yielded compound BHA03 (5.23 g, yield: 51%). (ESI) + -MS: m / z 1024.37 [M + ].

[0092] 1 H-NMR (500 mHz, DMSO-d6) δ 8.15 (s, 1H), 8.13 (s, 2H), 8.12 (d, 5H), 8.07 (s, 2H), 8.06 (d, 5H), 8.02 (s, 2H), 7.96 (s, 1H), 7.82 (s, 1H), 7.74(s, 2H), 7.69 (s, 1H), 7.60 (d, 1H), 7.61 – 7.57 (m, 8H), 7.58 – 7.55 (m,4H), 7.52 (d, 11H), 7.50 (s, 1H), 7.48 (s, 1H). Synthesis example 2 This synthetic example provides a method for synthesizing a host compound (denoted as BHA04), the chemical equation of which is shown below.

[0093] Under nitrogen protection, 50 mL of toluene, 12 mL of ethanol, and 10 mL of water were added to a Schlenk flask. Then, intermediates 04-a (7.00 g), 04-b (4.26 g), potassium carbonate (7.56 g), and tetraphenylphosphine palladium (2.54 g) were added. The mixture was heated to 95 °C and reacted for 12 h. After cooling to room temperature, the mixture was filtered. The filter cake was dissolved in toluene and filtered to remove the solid insolubles. Recrystallization yielded compound BHA04 (3.67 g, yield: 42%). (ESI) + -MS: m / z 872.31 [M + ].

[0094] 1H-NMR (500 mHz, DMSO-d6) δ 8.27 (s, 2H), 8.24 (s, 1H), 8.06 (s,11H), 8.00 (s, 1H), 7.99 (s, 2H), 7.92 (s, 1H), 7.90 (s, 1H), 7.89 (s, 1H),7.87 (s, 2H), 7.73 – 7.71 (m, 2H), 7.66 (s, 2H), 7.63 (s, 1H), 7.54 (s, 1H),7.52 (s, 12H). Synthesis example 3 This synthetic example provides a method for synthesizing a host compound (denoted as BHA05), the chemical equation of which is shown below.

[0095] Under nitrogen protection, 50 mL of toluene, 12 mL of ethanol, and 10 mL of water were added to a Schlenk flask. Then, intermediates 05-a (8.50 g), 05-b (4.26 g), potassium carbonate (7.56 g), and tetra-triphenylphosphine palladium (2.31 g) were added. The mixture was heated to 90 °C and reacted for 10 h. After cooling to room temperature, the mixture was filtered. The filter cake was dissolved in toluene and filtered again to remove insoluble solids. Recrystallization yielded compound BHA05 (5.02 g, yield: 49%). (ESI) + -MS: m / z 1024.37 [M + ].

[0096] 1 H-NMR (500 mHz, DMSO-d6) δ 8.27 (s, 2H), 8.11 (s, 1H), 8.09 (s, 1H), 8.08 (s, 1H), 8.06 (s, 10H), 7.99 (s, 2H), 7.90 (s, 1H), 7.87 (s, 2H), 7.81(d, 2H), 7.68 (s, 1H), 7.66 (d, 3H), 7.65 (d, 1H), 7.61 – 7.58 (m, 2H), 7.57– 7.54 (m, 5H), 7.51 (d, 14H). Synthesis example 4 This synthetic example provides a method for synthesizing a host compound (denoted as BHA06), the chemical equation of which is shown below.

[0097] Under nitrogen protection, 50 mL of toluene, 12 mL of ethanol, and 10 mL of water were added to a Schlenk flask. Then, intermediates 06-a (9.00 g), 06-b (4.26 g), potassium carbonate (7.56 g), and tetraphenylphosphine palladium (2.31 g) were added. The mixture was heated to 90 °C and reacted for 10 h. After cooling to room temperature, the mixture was filtered. The filter cake was dissolved in toluene and filtered again to remove insoluble solids. Recrystallization yielded compound BHA06 (4.74 g, yield: 44%). (ESI) + -MS: m / z 1076.40 [M + ].

[0098] 1 H-NMR (500 mHz, DMSO-d6) δ 8.29 (s, 1H), 8.12 (s, 1H), 8.09 (s, 1H), 8.07 (t, 2H), 8.06 (s, 8H), 8.04 (s, 1H), 7.99 (s, 1H), 7.96 (d, 2H), 7.87(t, 1H), 7.61 (d, 3H), 7.60 – 7.57 (m, 4H), 7.56 – 7.53 (m, 3H), 7.52 (s,10H), 7.46 – 7.44 (m, 1H), 7.44 – 7.41 (m, 5H), 7.39 (q, 3H), 7.36 (t, 5H). Synthesis example 5 This synthetic example provides a method for synthesizing a host compound (denoted as BHA07), the chemical equation of which is shown below.

[0099] Under nitrogen protection, 50 mL of toluene, 12 mL of ethanol, and 10 mL of water were added to a Schlenk flask. Then, intermediates 03-a (8.50 g), 07-b (4.26 g), potassium carbonate (7.42 g), and tetraphenylphosphine palladium (2.31 g) were added. The mixture was heated to 86 °C and reacted for 8 h. After cooling to room temperature, the mixture was filtered. The filter cake was dissolved in toluene and filtered again to remove the solid insolubles. Recrystallization yielded compound BHA07 (5.64 g, yield: 55%). (ESI) + -MS: m / z 1024.37 [M + ].

[0100] 1H-NMR (500 mHz, DMSO-d6) δ 8.26 (s, 1H), 8.13 (s, 2H), 8.12 (s, 4H), 8.07 (d, 3H), 8.06 (s, 4H), 8.04 (s, 1H), 8.02 (d, 3H), 8.00 (s, 1H), 7.94(s, 1H), 7.74 (s, 2H), 7.65 (s, 1H), 7.61 – 7.58 (m, 6H), 7.57 (s, 2H), 7.56– 7.54 (m, 2H), 7.54 (s, 1H), 7.52 (d, 12H), 7.50 (d, 1H), 7.48 (s, 1H). Synthesis example 6 This synthetic example provides a method for synthesizing a host compound (denoted as BHA08), the chemical equation of which is shown below.

[0101] Under nitrogen protection, 50 mL of toluene, 12 mL of ethanol, and 10 mL of water were added to a Schlenk flask. Then, intermediates 08-a (7.50 g), 08-b (4.26 g), potassium carbonate (7.42 g), and tetraphenylphosphine palladium (2.31 g) were added. The mixture was heated to 90 °C and reacted for 10 h. After cooling to room temperature, the mixture was filtered. The filter cake was dissolved in toluene and filtered to remove insoluble solids. Recrystallization yielded compound BHA08 (4.35 g, yield: 47%). (ESI) + -MS: m / z 924.34 [M + ].

[0102] 1 H-NMR (500 mHz, DMSO-d6) δ 8.29 (s, 1H), 8.15 (s, 1H), 8.09 (s, 1H), 8.06 (s, 8H), 8.03 (s, 1H), 7.97 (s, 1H), 7.90 (s, 1H), 7.64 (s, 1H), 7.61 –7.59 (m, 3H), 7.59 – 7.56 (m, 3H), 7.54 (s, 1H), 7.52 (s, 10H), 7.50 (q, 4H),7.48 (d, 1H), 7.45 (t, 1H), 7.43 (d, 2H), 7.42 (d, 1H), 7.40 – 7.38 (m, 2H),7.38 – 7.36 (m, 1H). Synthesis Example 7 This synthetic example provides a method for synthesizing a host compound (denoted as BHA09), the chemical equation of which is shown below.

[0103] Under nitrogen protection, 50 mL of toluene, 12 mL of ethanol, and 10 mL of water were added to a Schlenk flask. Then, intermediates 09-a (7.00 g), 09-b (4.26 g), potassium carbonate (7.42 g), and tetraphenylphosphine palladium (2.31 g) were added. The mixture was heated to 85 °C and reacted for 8 h. After cooling to room temperature, the mixture was filtered. The filter cake was dissolved in toluene and filtered to remove the insoluble solids. Recrystallization yielded compound BHA09 (4.37 g, yield: 50%). (ESI) + -MS: m / z 872.31 [M + ].

[0104] 1 H-NMR (500 mHz, DMSO-d6) δ 8.29 (s, 1H), 8.13 (s, 2H), 8.12 (s, 8H), 8.09 (s, 1H), 8.07 (s, 2H), 8.03 (s, 1H), 8.02 (s, 2H), 7.97 (s, 1H), 7.90(s, 1H), 7.74 (s, 2H), 7.68 (s, 1H), 7.60 (s, 2H), 7.57 (s, 2H), 7.54 (s,1H), 7.52 (d, 11H), 7.44 (s, 1H), 7.42 (s, 1H). Synthesis example 8 This synthetic example provides a method for synthesizing a host compound (denoted as BHA10), the chemical equation of which is shown below.

[0105] Under nitrogen protection, 50 mL of toluene, 12 mL of ethanol, and 10 mL of water were added to a Schlenk flask. Then, intermediates 10-a (9.00 g), 10-b (4.26 g), potassium carbonate (7.42 g), and tetraphenylphosphine palladium (2.54 g) were added. The mixture was heated to 90 °C and reacted for 9 h. After cooling to room temperature, the mixture was filtered. The filter cake was dissolved in toluene and filtered again to remove the solid insolubles. Recrystallization yielded compound BHA10 (4.41 g, yield: 43%). (ESI) + -MS: m / z 1076.40 [M + ].

[0106] 1H-NMR (500 mHz, DMSO-d6) δ 8.42 (s, 1H), 8.28 (s, 1H), 8.18 (s, 1H), 8.06 (s, 10H), 7.98 (s, 1H), 7.91 (s, 1H), 7.70 (s, 1H), 7.68 (s, 1H), 7.66(d, 1H), 7.65 (d, 1H), 7.61 – 7.59 (m, 8H), 7.58 – 7.56 (m, 4H), 7.55 (d,4H), 7.52 (d, 9H), 7.46 – 7.41 (m, 4H), 7.40 – 7.35 (m, 4H). Example 1 This embodiment provides an organic light-emitting ink composition (hereinafter referred to as the ink composition), denoted as INK01, which includes a triplet donor (BHT01), an annihilator (BHA01), a doped light-emitting material (BD01), and a non-halogenated aromatic solvent (ethyl benzoate and dodecylbenzene).

[0107] The preparation method of the above-mentioned organic light-emitting ink composition includes the following steps: Anhydrous and oxygen-free ethyl benzoate (11.20 g) and dodecylbenzene (4.80 g) were weighed separately in a mass ratio of 7:3. The cleaned and dried stir bar and vial were transferred to a glove box, and the two solvents were mixed until homogeneous. In the glove box, 0.03 g of triplet donor BHT01, 0.22 g of annihilator BHA01, and 0.01 g of doped luminescent material BD01 were weighed and transferred to a vial containing the mixed solvent, and stirred. The resulting mixture was stirred at 80°C until the organic functional material was completely dissolved. The heating was then removed, and the mixture was slowly cooled to room temperature and filtered through a 0.2 μm PTFE membrane to obtain the organic luminescent ink composition. 3 mL of the organic luminescent ink composition was used for performance testing, and the remainder was packaged and stored.

[0108] Examples 2-21 Examples 2-21 provide organic luminescent ink compositions, respectively designated INK02-INK21. The components of the heterogeneous TTA-UC system in their raw material composition are shown in Table 1. The component ratios and the selection of non-halogenated aromatic solvents are the same as in Example 1 and will not be repeated here.

[0109] The preparation method of the above organic light-emitting ink composition is similar to that of Example 1, and will not be repeated here.

[0110] Comparative Examples 1-10 Comparative Examples 1-10 provide organic luminescent ink compositions, designated DINK01-DINK10 respectively. The components of the heterogeneous TTA-UC system in their raw material compositions are shown in Table 1. The component ratios and the selection of non-halogenated aromatic solvents are the same as in Example 1 and will not be repeated. Note: The amount of annihilator in Comparative Examples 1, 2, and 5 is 0.25 g, and the amount of triplet donor in Comparative Examples 3 and 4 is 0.25 g.

[0111] The preparation method of the above organic light-emitting ink composition is similar to that of Example 1, and will not be repeated here.

[0112] The triplet, singlet, and quintet energy levels of the triplet donors BHT01~BHT03, annihilators BHA01~BHA16, doped luminescent materials BD01~BD02, and contrast annihilators DBHA01~DBHA03 were tested, and the results are shown in Table 1.

[0113] Triplet level (T1) measurement: A Hitachi F4600 fluorescence spectrometer was used at 77 K with a 2×10⁻⁶ Ω·cm fluorescence spectrometer. -5 The test was conducted using a mol / L toluene solution, and the measured low-temperature PL wavelength was converted into triplet energy E. T1 =1240 / λ PL E T1 λ represents the triplet energy of a material. PL This indicates the emission wavelength of the low-temperature PL.

[0114] Singlet level (S1) test: Similar to the triplet state, the PL wavelength measured at room temperature is converted into singlet energy using the same formula.

[0115] The quintet energy level (Q1): Using ORCA 6.0.1 software, based on the density functional theory (DFT) calculation method (basis set level set: b3lyp-d3 / 6-31G(d), charge number is 0), the ground state structure of the molecule is geometrically optimized and vibrationally analyzed (Opt+freq) to obtain the quintet energy of the material.

[0116] Table 1. Triplet, Singlet, and Quintet Energy Levels of Each Compound in the Organic Light-Emitting Ink Composition Application Example 1 This application example provides a single-emitting-layer organic electroluminescent device, the structure of which includes an anode ITO, a hole injection layer PEDOT:PSS, a hole transport layer PVK, an emissive layer EML, an electron transport layer TPBi, an electron injection layer Liq, and a cathode Al, sequentially disposed on a substrate. PEDOT:PSS is an aqueous conductive polymer composite material composed of poly(3,4-ethylenedioxythiophene) (PEDOT) and polystyrene sulfonate (PSS).

[0117] The fabrication method of the above-mentioned single-emitting-layer organic electroluminescent device specifically includes the following steps: Step 1: Load the organic light-emitting ink composition INK01 from Example 1 into an ink container and assemble it into an inkjet printer, such as a Dimatix Materials Printer DMP-3000 (Fujifilm). Adjust the waveform, pulse time, and voltage of the ejected ink to optimize ink ejection and achieve a stable ink ejection range.

[0118] Step 2: Pattern the cleaned 50mm×50mm indium tin oxide (ITO) substrate to form a pixel defining layer, which contains holes for depositing inkjet printing material.

[0119] Step 3: The hole injection layer (HIL) and hole transport layer (HTL) materials are sequentially inkjet printed into the holes, and the solvent is removed by vacuum drying to obtain HIL / HTL films. The HIL film (30nm thick) is composed of PEDOT:PSS, and the HTL film (45nm thick) is composed of PVK.

[0120] Step 4: The organic light-emitting ink composition INK01 is printed onto the HIL / HTL film by inkjet printing, and the solvent is removed by high-temperature drying in a vacuum environment to obtain an organic light-emitting film (EML) (45nm thick).

[0121] Step 5: Electron transport layer (ETL) (30nm thick), electron injection layer (EIL) (1nm thick), and cathode (120nm thick) are sequentially formed on EML by vacuum thermal evaporation of TPBi, Liq, and aluminum (Al). Finally, the device is encapsulated to obtain a single-emitting-layer organic electroluminescent device.

[0122] In a single-emitting-layer organic electroluminescent device, the molecular structural formulas of each layer material (all of which are commercially available) are as follows: Application Examples 2-21 Application Examples 2-21 each provide a single-emitting-layer organic electroluminescent device, whose structure and preparation method are similar to those of Application Example 1, except that the organic light-emitting ink composition INK01 is replaced with organic light-emitting ink compositions INK02-INK21. All other parameters and conditions are the same as in Application Example 1 and will not be repeated here.

[0123] Compare and contrast examples 1-10 Comparative Application Examples 1-10 each provide a single-emitting-layer organic electroluminescent device, whose structure and preparation method are similar to those of Application Example 1, except that the organic light-emitting ink composition INK01 is replaced with organic light-emitting ink compositions DINK01-DINK10. All other parameters and conditions are the same as in Application Example 1 and will not be repeated here.

[0124] Verification test The performance parameters of the single-emitting-layer organic electroluminescent devices (blue OLED devices) in Application Examples 1-21 and Comparative Application Examples 1-10 were tested using the reference standard method, and the results are shown in Table 2.

[0125] At J = 10 mA / cm 2 The driving voltage (Vop), luminance, and external quantum efficiency (EQE, measured as a percentage) of a single-emitting-layer organic electroluminescent device are determined at a given current density. EQE is calculated as a function of luminous density from the current / voltage / luminous density characteristic line (IVL characteristic line) exhibiting Lambertian emission characteristics.

[0126] The lifetime LT is defined as the time after which the brightness decreases from the initial luminous intensity L0 to L1 when operating at a constant current density J. For example, LT95 refers to the lifetime of the fabricated blue OLED device at J = 20 mA / cm². 2 When operating, the luminous intensity drops to 95% of its initial value L0 after time LT95.

[0127] The testing instruments used for performance testing are as follows: Brightness: Tested using a PhotoResearch PR-655 spectral scanner.

[0128] Electroluminescence current efficiency (cd / A) was measured using a PhotoResearch PR-635 spectral scanner.

[0129] Current density and turn-on voltage: tested using a Keithley 2400 digital source meter.

[0130] Lifetime testing: Using a silicon photonics-based OLED device lifetime testing system.

[0131] Table 2 Performance test results of single-emitting-layer organic electroluminescent devices As can be seen from the table above, the single-emitting-layer organic electroluminescent device based on the heterogeneous TTA-UC system provided by this invention has significant advantages in terms of luminous efficiency and lifetime.

[0132] Application Examples 3-12 and Application Examples 19-21 used the host compound containing the phenanthrene-benzofuran structure provided by the present invention, which has a more balanced carrier transport. Therefore, compared with Application Examples 1-2 and Application Examples 13-18, the efficiency is more significantly improved and the lifetime is also slightly improved.

[0133] Comparative Application Examples 1-2 and 5 did not include a triplet donor, but only used an annihilation agent. Furthermore, Comparative Application Examples 1-2 were not the preferred host compound structures of this invention, and their luminescence efficiency and lifetime were both at a low level. Comparative Application Examples 3-4 did not include an annihilation agent, but only used a triplet donor as the host material of the luminescent layer, and it can be seen that their luminescence efficiency and lifetime performance were the worst.

[0134] Compared with the application examples 6-10, where the luminescent layer contains both a triplet host and an annihilation agent, but the annihilation agent is not a polyanthracene compound preferred by the present invention, it can be seen that the lifetime is not significantly improved, while the efficiency is slightly improved, but it is significantly less effective than the polyanthracene compounds provided in application examples 1-21.

[0135] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A heterogeneous TTA-UC system for single-emitting-layer organic electroluminescent devices, characterized in that, It comprises a triplet donor, an annihilation agent, and a doped luminescent material; the annihilation agent is a polyanthracene compound. The first singlet state energy level of the triplet donor is S. 1-BHT The first triplet energy level is T 1-BHT The first singlet energy level of the annihilation agent is S. 1-BHA The first triplet energy level is T 1-BHA The first singlet energy level of the doped luminescent material is S. 1-BD And T 1-BHT >T 1-BHA S 1-BHT >S 1-BD S 1-BHA >S 1-BD 2×T 1-BHA >S 1-BHA .

2. The heterogeneous TTA-UC system for single-emitting-layer organic electroluminescent devices as described in claim 1, characterized in that, The first triplet energy level of the doped luminescent material is T. 1-BD T 1-BD >T 1-BHA ; S 1-BHT >S 1-BHA >S 1-BD ; 2×T 1-BHT >S 1-BHT 。 3. The heterogeneous TTA-UC system for single-emitting-layer organic electroluminescent devices as described in claim 2, characterized in that, T 1-BD >T 1-BHT >T 1-BHA ; 0.1eV<T 1-BHT -T 1-BHA <0.5eV;S 1-BHT -S 1-BHA <0.6eV。 4. The heterogeneous TTA-UC system for single-emitting-layer organic electroluminescent devices as described in claim 3, characterized in that, The first quintet energy level of the annihilator is Q. 1-BHA And Q 1-BHA >2×T 1-BHA >S 1-BHA ; The first quintet energy level of the triplet donor is Q. 1-BHT And Q 1-BHT >2×T 1-BHT >S 1-BHT .

5. The heterogeneous TTA-UC system for single-emitting-layer organic electroluminescent devices as described in any one of claims 1 to 4, characterized in that, The triplet donor is selected from at least one of the compounds shown in formulas I-1 to I-6. I-1 I-2 I-3 I-4 I-5 I-6 In formulas I-1~I-6, Ar T11 Ar T51 Ar T61 Ar T62 It represents substituted or unsubstituted aryl groups with 6 to 60 carbon atoms, and substituted or unsubstituted heteroaryl groups with 3 to 60 carbon atoms; Ar T12 Ar T13 Ar T14 Each of these groups independently represents hydrogen, an alkyl group with 1 to 15 carbon atoms, an alkoxy group with 1 to 15 carbon atoms, a substituted or unsubstituted aryl group with 6 to 30 carbon atoms, or a substituted or unsubstituted heteroaryl group with 3 to 30 carbon atoms, and Ar T13 Ar T14 At least one of them is H; Ar T21 Ar T22 Ar T23 Ar T24 Ar T31 Ar T32 Ar T41 Ar T42 Each is independently selected from hydrogen, substituted or unsubstituted aryl groups with 6 to 60 carbon atoms, and substituted or unsubstituted heteroaryl groups with 3 to 60 carbon atoms; and Ar T21 Ar T22 Ar T23 Ar T24 Not entirely hydrogen, Ar T31 Ar T32 Not entirely hydrogen, Ar T41 Ar T42 Not all of it is hydrogen; Ar T52 Ar T53 Ar T54 Ar T63 Ar T64 Each can independently represent hydrogen, substituted or unsubstituted aryl groups with 6 to 30 carbon atoms, or substituted or unsubstituted heteroaryl groups with 3 to 30 carbon atoms; L represents substituted or unsubstituted aryl groups with 6 to 30 carbon atoms, and substituted or unsubstituted heteroaryl groups with 3 to 30 carbon atoms; Any hydrogen atom in formulas I-1 to I-6 can be independently replaced by deuterium.

6. The heterogeneous TTA-UC system for single-emitting-layer organic electroluminescent devices as described in claim 5, characterized in that, In formulas I-1 to I-6, the aryl group includes phenyl, naphthyl, biphenyl, phenanthryl, anthracene, pyrene, or fluorenyl; the heteroaryl group includes benzofuranyl, dibenzofuranyl, naphthobenzofuranyl, phenanthrene[4,5-bcd]furanyl, phenanthrenebenzofuranyl, benzothiophene, dibenzothiophene, carbazoyl, pyridyl, pyrimidinyl, pyrazinyl, triazinyl, N-phenylindolyl, quinolinyl, or isoquinolinyl; In formulas I-1 to I-6, the arylene groups include phenylene, naphthylene, biphenylene, phenanthrene, anthracene, pyrene, or fluorene; the heteroarylene groups include dibenzofuranylene, naphthanobenzofuranylene, phenanthrenebenzofuranylene, or phenanthrene[4,5-bcd]furanylene. When Ar in formulas I-1~I-6 T11 ~Ar T14 Ar T21 ~Ar T24 Ar T31 Ar T32 Ar T41 Ar T42 Ar T51 ~Ar T54 Ar T61 ~Ar T64 When L contains a substituent, the substituent includes deuterium, alkyl with 1 to 12 carbon atoms, alkoxy with 1 to 12 carbon atoms, substituted or unsubstituted aryl with 6 to 20 carbon atoms, and substituted or unsubstituted heteroaryl with 3 to 20 carbon atoms.

7. The heterogeneous TTA-UC system for single-emitting-layer organic electroluminescent devices as described in claim 6, characterized in that, When Ar in formulas I-1~I-6 T11 ~Ar T14 Ar T21 ~Ar T24 Ar T31 Ar T32 Ar T41 Ar T42 Ar T51 ~Ar T54 Ar T61 ~Ar T64 When L contains a substituent, the substituent includes deuterium, phenyl, naphthyl, biphenyl, phenanthryl, anthraceneyl, pyrene, dibenzofuranyl, naphthobenzofuranyl, or phenanthrenebenzofuranyl.

8. The heterogeneous TTA-UC system for single-emitting-layer organic electroluminescent devices as described in claim 5, characterized in that, The triplet donor is selected from at least one of the following structural formulas. In the above structural formula, any one of the hydrogen atoms can be independently replaced by deuterium.

9. The heterogeneous TTA-UC system for single-emitting-layer organic electroluminescent devices as described in any one of claims 1 to 4, characterized in that, The annihilating agent is selected from compounds shown in formulas II-1 to II-2. II-1 II-2 In equations II-1 to II-2, Ar A1 Ar A2 Ar A3 Ar A4 Ar A5 Ar A6 Each can be independently represented as an aryl group with 6 to 60 substituted or unsubstituted carbon atoms, or a heteroaryl group with 3 to 60 substituted or unsubstituted carbon atoms; L1, L2, L4, and L5 each independently represent a single bond, phenylene, biphenylene, or naphthylene; L0 and L3 are selected from single bonds, substituted or unsubstituted aryl groups with 6 to 30 carbon atoms, and substituted or unsubstituted heteroaryl groups with 3 to 30 carbon atoms; In Formula II, any hydrogen atom can be independently replaced by deuterium.

10. The heterogeneous TTA-UC system for single-emitting-layer organic electroluminescent devices as described in claim 9, characterized in that, In formulas II-1 to II-2, the aryl group includes phenyl, naphthyl, biphenyl, phenanthryl, anthracene, or fluorenyl; the heteroaryl group includes benzofuranyl, dibenzofuranyl, naphthobenzofuranyl, phenanthrene[4,5-bcd]furanyl, phenanthrenebenzofuranyl, benzothiophene, dibenzothiophene, carbazoyl, pyridyl, pyrimidinyl, pyrazinyl, triazinyl, N-phenylindolyl, quinolinyl, or isoquinolinyl; In formulas II-1 to II-2, the arylene groups include phenylene, naphthylene, biphenylene, phenanthrene, anthracene, pyrene, or fluorene; the heteroarylene groups include dibenzofuranylene, naphthanobenzofuranylene, phenanthrenebenzofuranylene, or phenanthrene[4,5-bcd]furanylene. When Ar in equations II-1 to II-2 A1 Ar A2 Ar A3 Ar A4 Ar A5 Ar A6 When L0 and L3 contain substituents, the substituents include deuterium, alkyl groups having 1 to 12 carbon atoms, alkoxy groups having 1 to 12 carbon atoms, substituted or unsubstituted aryl groups having 6 to 20 carbon atoms, and substituted or unsubstituted heteroaryl groups having 3 to 20 carbon atoms.

11. The heterogeneous TTA-UC system for single-emitting-layer organic electroluminescent devices as described in claim 10, characterized in that, When Ar in equations II-1 to II-2 A1 Ar A2 Ar A3 Ar A4 Ar A5 Ar A6 When a substituent is present, the substituent includes deuterium, phenyl, naphthyl, or biphenyl; In formulas II-1 to II-2, L0 and L3 are selected from single bonds, phenylene, naphthylene, dimethylfluorene, diphenylfluorene, dibenzofuranyl, naphthylbenzobenzofuranyl or phenanthrene[4,5-bcd]furanyl, and any one of the hydrogen atoms in L0 and L3 can be independently substituted with deuterium; In equations II-1 to II-2, Ar A1 Ar A2 Ar A3 Ar A4 Ar A5 Ar A6 Each is independently selected from substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, or substituted or unsubstituted dibenzofuranyl.

12. The heterogeneous TTA-UC system for single-emitting-layer organic electroluminescent devices as described in claim 9, characterized in that, The triplet donor is selected from at least one of the following structural formulas. In the above structural formula, any one of the hydrogen atoms can be independently replaced by deuterium.

13. The heterogeneous TTA-UC system for single-emitting-layer organic electroluminescent devices as described in any one of claims 1 to 4, characterized in that, The mass ratio of the triplet donor to the annihilator is (1~50):(50~1), and the mass of the doped luminescent material accounts for 0.01%~10% of the total mass of the heterogeneous TTA-UC system.

14. A host compound containing a phenanthrenebenzofuran structure, characterized in that, As an annihilator in the heterogeneous TTA-UC system for a single-emitting-layer organic electroluminescent device according to any one of claims 1 to 13; the general structural formula of the host compound containing the phenanthrenebenzofuran structure is shown in Formula IV. IV In Equation IV, Ar A7 Ar A8 Each can be used independently to represent substituted or unsubstituted aryl groups with 6 to 30 carbon atoms, or substituted or unsubstituted heteroaryl groups with 3 to 30 carbon atoms. L7 and L8 each independently represent a single bond, phenylene, biphenylene, or naphthylene; L6 is selected from any one of the structures shown in formulas IV-1 to IV-6. IV-1 IV-2 IV-3 IV-4 IV-5 IV-6 R 101 ~R 112 R 201 ~R 212 R 301 ~R 312 R 401 ~R 412 R 501 ~R 512 R 601 ~R 612 Each of the components independently contains two single bonds, which are connected to L7 and L8 respectively, and the remaining components are independently selected from hydrogen, alkyl with 1 to 12 carbon atoms, substituted or unsubstituted aryl with 6 to 30 carbon atoms, and substituted or unsubstituted heteroaryl with 4 to 18 carbon atoms. In Formula IV, any hydrogen atom can be independently replaced by deuterium.

15. The host compound containing a phenanthrene-benzofuran structure as described in claim 14, characterized in that, In formula IV-1, R101, R102, R103, R104, and R105 contain two single bonds; In formula IV-2, R201, R202, R203, R204, and R205 contain two single bonds; In formula IV-3, R301, R302, R303, R304, R305, and R306 contain two single bonds; In formula IV-4, R401, R402, R403, R404, R405, and R406 contain two single bonds; In formula IV-5, R501, R502, R503, R504, R505, and R506 contain two single bonds, and R501, R502, R503, and R504 contain at least one single bond. In formula IV-6, R601, R602, R603, R604, R605, R606, R607, R608, R609, and R610 contain two single bonds, and R601, R602, R603, and R604 contain at least one single bond.

16. The host compound containing a phenanthrene-benzofuran structure as described in claim 14, characterized in that, In Equation IV, Ar A7 Ar A8 Each independently represents a substituted or unsubstituted aryl group with 6 to 30 carbon atoms; when Ar A7 Ar A8 When a substituent is present, the substituent may be one or more, and the substituent may be selected from deuterium, alkyl groups having 1 to 10 carbon atoms, or phenyl groups.

17. The host compound containing a phenanthrene-benzofuran structure as described in claim 16, characterized in that, In Equation IV, Ar A7 Ar A8 Each can independently represent a substituted or unsubstituted phenyl, naphthyl, or biphenyl group; L7 and L8 each independently represent a single bond. , , , , , , or In L7 and L8, any one of the hydrogen atoms can be independently replaced by deuterium.

18. The host compound containing a phenanthrene-benzofuran structure as described in claim 16, characterized in that, In Equation IV, Ar A7 Ar A8 Each independently selected , , , or ; L7 and L8 each independently represent a single bond or a phenylene group.

19. The host compound containing a phenanthrene-benzofuran structure as described in claim 14, characterized in that, The host compound containing the phenanthrenebenzofuran structure is selected from any one of the following structural formulas. In the above structure, any one hydrogen atom can be independently replaced by deuterium.

20. An organic light-emitting ink composition, characterized in that, Includes the heterogeneous TTA-UC system for single-emitting-layer organic electroluminescent devices as described in any one of claims 1 to 13.

21. The organic light-emitting ink composition as claimed in claim 20, characterized in that, The organic light-emitting ink composition comprises the host compound containing a phenanthrene-benzofuran structure as described in any one of claims 14 to 19.

22. The organic light-emitting ink composition as claimed in claim 20 or 21, characterized in that, The organic light-emitting ink composition further includes at least one non-halogenated aromatic solvent; the mass ratio of the heterogeneous TTA-UC system to the non-halogenated aromatic solvent is (1~400):1000.

23. A single-emitting-layer organic electroluminescent device, characterized in that, The raw materials of its light-emitting layer include the heterogeneous TTA-UC system as described in any one of claims 1 to 13 or the organic light-emitting ink composition as described in any one of claims 20 to 22.

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