Mixture and application thereof in photoelectric field

Abstract

A mixture comprising two host materials (a first host material H1 and a second host material H2) capable of forming an exciplex and two emitters (a first emitter E1 and a second emitter E2) wherein the first emitter E1 is an MR-TADF material and the absorption spectrum of the second emitter E2 and the emission spectrum of the first emitter E1 at least partially overlap each other; therefore, effective resonance energy transfer is achieved between the two light-emitting bodies. The first illuminant E1 is preferably selected from a first host material H1, the second illuminant E2 is preferably selected from an MR-TADF material, and the half-peak width of the luminous spectrum of the second illuminant E2 is smaller than or equal to 40 nm. The invention further discloses a composition (printing ink) containing the first host material H1, the second host material H2, the first illuminant E1 and the second illuminant E2, and a technical option is provided for OLED printing. The invention further discloses a photoelectric device, especially an organic electroluminescent device, the luminescent layer of which contains the mixture, and the organic electroluminescent device according to the invention has both high luminous efficiency and long device life.

Description

Technical Field

[0001] This invention relates to the field of organic optoelectronic materials and devices, and in particular to a mixture, a composition comprising the mixture, optoelectronic devices, and their applications in the optoelectronic field. Background Technology

[0002] Organic semiconductor materials are diverse in synthesis, have relatively low manufacturing costs, and possess excellent optical and electrical properties. Organic light-emitting diodes (OLEDs) have become the mainstream technology for optoelectronic devices (such as flat panel displays and lighting).

[0003] To date, OLED luminescent material systems based on fluorescence and phosphorescence have been developed. Organic light-emitting diodes (OLEDs) using fluorescent materials exhibit high reliability, but their internal electroluminescence quantum efficiency under electrical excitation is limited to 25% due to the 1:3 branching ratio of singlet to triplet excited states of the exciton. In contrast, OLEDs using phosphorescent materials have achieved nearly 100% internal electroluminescence quantum efficiency. Based on phosphorescent materials, phosphorescence-sensitized fluorescence technology (PSF, see Forrest et al., Nature, 2000, 403, 750) has also been developed. Currently, commercially successful phosphorescent materials are metal complexes containing rare and precious metals such as Ir or Pt. The high cost of raw materials, coupled with the complexity of their synthesis, results in high material costs. Qiu Yong and Duan Lian et al. proposed a strategy of thermally excited delayed fluorescence material-sensitized fluorescence (TADF) (see Zhang et al., Adv. Mater. 2014, 26, 5050, or Chinese patent ZL201310692266.2), which can achieve 100% internal electroluminescence quantum efficiency using pure organic compounds. However, the lifetime of TSF-based OLEDs is lower than that of phosphorescent OLEDs or phosphorescently sensitized fluorescent OLEDs, i.e., PSF-OLEDs; especially blue light, phosphorescent OLEDs, PSF-OLEDs, and TSF-OLEDs, their lifetimes are still far from commercialization.

[0004] Therefore, existing solutions for OLED luminescent materials, especially blue luminescent materials, still need to be improved and developed. Summary of the Invention

[0005] Based on this, the object of the present invention is to provide a mixture, a composition comprising the mixture, an optoelectronic device (particularly an organic electroluminescent device), and its application in the optoelectronic field.

[0006] The specific technical solution is as follows:

[0007] A mixture comprising a first host material H1, a second host material H2, a first luminescent material E1, and a second luminescent material E2, wherein: 1) the emission peak wavelength of the first luminescent material E1 is shorter than the emission peak wavelength of the second luminescent material E2, and the absorption spectrum of the second luminescent material E2 and the emission spectrum of the first luminescent material E1 at least partially overlap; 2) the first luminescent material E1 is selected from MR-TADF materials, preferably selected from structures shown in chemical formula (I-1) or (I-2); 3) E T1 (E1)≤min[LUMO(H1)-HOMO(H2),LUMO(H2)-HOMO(H1)]≤min[E T1 (H1), E T1 [(H2)]+0.1eV, where E T1 (E1) is the triplet energy level of the first luminescent body E1, LUMO(H1), HOMO(H1) and E T1 (H1) represents the lowest unoccupied orbital, the highest occupied orbital, and the triplet state energy level of the first host material H1, respectively, LUMO(H2), HOMO(H2), and E. T1 (H2) represents the lowest unoccupied orbital, the highest occupied orbital, and the triplet energy level of the second host material H2, respectively.

[0008]

[0009] in:

[0010] Ar 1 -Ar 3 The same or different ones are selected from aromatic or heteroaromatic groups having 5 to 24 ring atoms;

[0011] Ar 4 -Ar 5 The same or different are selected from aromatic or heteroaromatic groups with empty ring atoms or having 5 to 24 ring atoms;

[0012] When Ar 4 -Ar 5 When not empty, X a and X b Each occurrence is independently selected from N, C(R) 6 ) or Si(R 6 ), Y a and Y b Each occurrence is independently selected from B, P=O, and C(R). 6 ) or Si(R 6 );

[0013] When Ar 4 Or Ar 5 When X is empty b Selected from N, C(R)6 ) or Si(R 6 ), Y a Selected from B, P=O, C(R) 6 ) or Si(R 6 ), corresponding X a Or Y b Each occurrence is independently selected from N(R) 6 ), C(R 6 R 7 ), Si(R) 6 R 7 C=O, O, C=N(R) 6 ), C = C(R) 6 R 7 ), P(R 6 ), P(=O)R 6 S, S = O or SO2;

[0014] X 1 X 2 It is independently selected from empty space or a bridging group;

[0015] R 1 -R 7 Each time it appears, it may be selected from H, D, or straight-chain alkyl, haloalkyl, alkoxy, or thioalkoxy groups having 1 to 20 carbon atoms; or branched or cyclic alkyl, haloalkyl, alkoxy, thioalkoxy, or silyl groups having 3 to 20 carbon atoms; or substituted ketyl groups having 1 to 20 carbon atoms; or alkoxycarbonyl groups having 2 to 20 carbon atoms; or aryloxycarbonyl groups having 7 to 20 carbon atoms; or cyano groups, carbamoyl groups, haloformyl groups, formyl groups, or isocyano groups. The following groups are included: isocyanate groups, thiocyanate groups, isothiocyanate groups, hydroxyl groups, nitro groups, CF3, Cl, Br, F, I, crosslinkable groups, or substituted or unsubstituted aromatic or heteroaromatic ring systems having 5 to 40 ring atoms, or aryloxy or heteroaryloxy groups having 5 to 40 ring atoms, or arylamine or heteroarylamine groups having 5 to 40 ring atoms, disubstituted units at any position of the above groups, or combinations of these groups, wherein one or more groups may form monocyclic or polycyclic aliphatic or aromatic ring systems with each other and / or with the rings bonded to the groups.

[0016] Preferably, the second luminescent body E2 is selected from chemical formula (I-1), chemical formula (I-2), or aromatic amine derivatives.

[0017] Preferably, the first host material H1 is selected from chemical formula (III-1) or chemical formula (III-2); and / or the second host material H2 is selected from chemical formula (IV):

[0018]

[0019] Among them: Z 101 -Z 103 Selected independently from N or CR 12 And at least one of them is selected from N; L1-L3 are selected from single bonds, or substituted or unsubstituted aromatic or heteroaromatic groups with 6 to 30 ring atoms; Ar 6 -Ar 11 Selected from substituted or unsubstituted aromatic or heteroaromatic groups having 5 to 40 ring atoms, or aryloxy or heteroaryloxy groups having 5 to 40 ring atoms, or combinations of these groups, wherein one or more groups may form a monocyclic or polycyclic aliphatic or aromatic ring system with each other and / or with the rings bonded to the groups.

[0020] R 8 -R 12 The definition of R is as described above. 1 ;

[0021] n1, n3, and n4 are each independently selected from integers from 0 to 7;

[0022] n2 is an integer selected from 0 to 8.

[0023] The present invention further provides a composition comprising a mixture as described above and at least one organic solvent.

[0024] The present invention also provides an optoelectronic device comprising a mixture as described above.

[0025] Preferably, the optoelectronic device is an organic electroluminescent device, and includes a substrate, an anode, a light-emitting layer and a cathode arranged sequentially, wherein the light-emitting layer comprises at least one mixture as described above, or the light-emitting layer is prepared using a composition as described above.

[0026] Beneficial effects: The organic electroluminescent device according to the present invention comprises a first host material H1 and a second host material H2, which readily form an exciplex; it also comprises a BN compound (first emitting element E1) with MR-TADF characteristics, which can fully utilize the triplet and singlet state energies of the exciplex. The absorption spectrum of the second emitting element E2 is on one side of the shorter wavelength of the emission spectrum of the first emitting element E1, and at least partially overlaps with it, thus achieving efficient energy resonant transfer between the first emitting element E1 and the second emitting element E2. Resonance Energy Transfer (FRET) achieves both high efficiency and long lifetime. Furthermore, the second emitting element E2 is preferably a BN compound with a narrow emission spectrum, which can achieve a high color gamut. Attached Figure Description

[0027] Figure 1 The emission (PL) spectrum of E1-1 in toluene and the absorption (Abs) and emission (PL) spectrum of E2-1 in toluene are shown. Detailed Implementation

[0028] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0029] 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 specification of this 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.

[0030] In the description of the embodiments of the present invention, the numerical range represented by “~” refers to the range including the values ​​recorded before and after “~” as the lower limit and upper limit values.

[0031] In the description of the embodiments of the present invention, the substituents may be further substituted by substituents, and "substituted group a" may refer to group a being substituted by a substituent, which may be substituted by at least one further substituent or may not be substituted.

[0032] In this invention, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0033] In this invention, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both represent: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0034] It should be understood that in various embodiments of the present invention, the order of the above-mentioned processes does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0035] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0036] The term "OLED" is an abbreviation for "Organic Light Emitting Diode," also known as organic electroluminescent display or organic light-emitting semiconductor. OLEDs are current-driven organic light-emitting devices that emit light through the injection and recombination of charge carriers; the luminous intensity is directly proportional to the injected current. Under the influence of an electric field, holes generated at the anode and electrons generated at the cathode move and are injected into the hole transport layer and electron transport layer, respectively, migrating to the emissive layer. When these two electrons meet in the emissive layer, they generate excitons, which excite the light-emitting molecules to ultimately produce visible light.

[0037] The term "TADF" is an abbreviation for "Thermally Activated Delayed Fluorescence," which essentially refers to the phenomenon where, when the energies of a triplet excited state and a singlet excited state are close, the triplet excited state can undergo a thermally activated reverse intersystem crossing (ISC) to return to the singlet excited state. Traditional luminescence occurs through fluorescence and phosphorescence, where the exciton returns to the ground state via radiative emission from the singlet and triplet states, respectively. Furthermore, the energy difference between lower singlet and triplet states is generally large, meaning that once an exciton reaches the triplet state from the singlet state via the ISC process, it cannot return to the singlet state.

[0038] In this invention, the main material, matrix material, host material, and matrix material have the same meaning and can be used interchangeably.

[0039] In this invention, organometallic complexes, organometallic coordination compounds, and organometallic coordination compounds have the same meaning and can be used interchangeably.

[0040] In this invention, composition, printing ink, ink and ink ink have the same meaning and can be used interchangeably.

[0041] This invention provides a mixture comprising a first host material H1, a second host material H2, a first luminescent material E1, and a second luminescent material E2, wherein: 1) the emission peak wavelength of the first luminescent material E1 is shorter than the emission peak wavelength of the second luminescent material E2, and the absorption spectrum of the second luminescent material E2 and the emission spectrum of the first luminescent material E1 at least partially overlap; 2) the first luminescent material E1 is selected from MR-TADF materials, preferably from structures represented by chemical formulas (I-1) or (I-2); 3) E is defined as... ex =min[LUMO(H1)-HOMO(H2),LUMO(H2)-HOMO(H1)],E T1 (E1)≤E ex ≤min[E T1 (H1), E T1 [(H2)]+0.1eV, where E T1 (E1) is the triplet energy level of the first luminescent body E1, LUMO(H1), HOMO(H1) and E T1 (H1) represents the lowest unoccupied orbital, the highest occupied orbital, and the triplet energy level of the first host material H1, respectively, LUMO(H2), HOMO(H2), and E. T1 (H2) represents the lowest unoccupied orbital, the highest occupied orbital, and the triplet energy level of the second host material H2, respectively.

[0042]

[0043] in:

[0044] Ar 1 -Ar 3 The same or different ones are selected from aromatic or heteroaromatic groups having 5 to 24 ring atoms;

[0045] Ar 4 -Ar 5 The same or different are selected from aromatic or heteroaromatic groups with empty ring atoms or having 5 to 24 ring atoms;

[0046] When Ar 4 -Ar 5 When not empty, X aand X b Each occurrence is independently selected from N, C(R) 6 ) or Si(R 6 ), Y a and Y b Each occurrence is independently selected from B, P=O, and C(R). 6 ) or Si(R 6 );

[0047] When Ar 4 Or Ar 5 When X is empty b Selected from N, C(R) 6 ) or Si(R 6 ), Y a Selected from B, P=O, C(R) 6 ) or Si(R 6 ), corresponding X a Or Y b Each occurrence is independently selected from N(R) 6 ), C(R 6 R 7 ), Si(R) 6 R 7 ), C=O, O, C=N(R) 6 ), C = C(R) 6 R 7 ), P(R 6 ), P(=O)R 6 S, S = O or SO2;

[0048] X 1 X 2 It is independently selected from empty space or a bridging group;

[0049] R 1 -R 7Each time it appears, it may be selected from H, D, or straight-chain alkyl, haloalkyl, alkoxy, or thioalkoxy groups having 1 to 20 carbon atoms; or branched or cyclic alkyl, haloalkyl, alkoxy, thioalkoxy, or silyl groups having 3 to 20 carbon atoms; or substituted ketyl groups having 1 to 20 carbon atoms; or alkoxycarbonyl groups having 2 to 20 carbon atoms; or aryloxycarbonyl groups having 7 to 20 carbon atoms; or cyano groups, carbamoyl groups, haloformyl groups, formyl groups, or isocyano groups. The following groups are included: isocyanate groups, thiocyanate groups, isothiocyanate groups, hydroxyl groups, nitro groups, CF3, Cl, Br, F, I, crosslinkable groups, or substituted or unsubstituted aromatic or heteroaromatic ring systems having 5 to 40 ring atoms, or aryloxy or heteroaryloxy groups having 5 to 40 ring atoms, or arylamine or heteroarylamine groups having 5 to 40 ring atoms, disubstituted units at any position of the above groups, or combinations of these groups, wherein one or more groups may form monocyclic or polycyclic aliphatic or aromatic ring systems with each other and / or with the rings bonded to the groups.

[0050] In a preferred embodiment, the first luminescent material E1 is selected from other MR-TADF materials.

[0051] The emission peak wavelength of the first light emitter E1 is smaller than that of the second light emitter E2. In some preferred embodiments, the difference is ≤20nm, preferably ≤15nm, more preferably ≤10nm, particularly preferably ≤7nm, and most preferably ≤5nm.

[0052] In a preferred embodiment, the absorption spectrum of the second light emitter E2 is on the shorter wavelength side of the emission spectrum of the first light emitter E1.

[0053] In other embodiments, the absorption spectrum of the second light emitter E2 is on the longer wavelength side of the emission spectrum of the first light emitter E1.

[0054] In a preferred embodiment, the difference between the peak of the absorption spectrum of the second light emitter E2 and the peak of the emission spectrum of the first light emitter E1 is ≤10nm, preferably ≤8nm, more preferably ≤6nm, particularly preferably ≤5nm, and most preferably ≤4nm.

[0055] In a preferred embodiment, E T1 (E1)≥E T1 (E2).

[0056] In some preferred embodiments, the full width at half maximum (FWHM) of the emission spectrum of the second emitting element E2 is ≤45nm, preferably ≤40nm, more preferably ≤35nm, and most preferably ≤30nm.

[0057] In some other preferred embodiments, the second light emitter E2 and the first light emitter E1 have a fluorescence quantum efficiency (PLQY) of ≥60%, preferably ≥65%, more preferably ≥70%, even more preferably ≥80%, and most preferably ≥85%.

[0058] In some preferred embodiments, R 1 -R 7 Each time it appears, it may be selected from H, D, or straight-chain alkyl, haloalkyl, alkoxy, or thioalkoxy groups having 1 to 10 carbon atoms; or branched or cyclic alkyl, haloalkyl, alkoxy, thioalkoxy, or silyl groups having 3 to 10 carbon atoms; or substituted ketyl groups having 1 to 10 carbon atoms; or alkoxycarbonyl groups having 2 to 10 carbon atoms; or aryloxycarbonyl groups having 7 to 10 carbon atoms; or cyano groups (-CN), carbamoyl groups (-C(=O)NH2), or haloformyl groups (-C(=O)-X). X represents a halogen atom), formyl group (-C(=O)-H), isocyanate group, isocyanate group, thiocyanate group, isothiocyanate group, hydroxy group, nitro group, CF3, Cl, Br, F, I, crosslinkable group, or substituted or unsubstituted aromatic or heteroaromatic ring system having 5 to 20 ring atoms, or aryloxy or heteroaryloxy group having 5 to 20 ring atoms, or arylamine or heteroarylamine group having 5 to 20 ring atoms, or a combination of these groups, wherein one or more groups may form a monocyclic or polycyclic aliphatic or aromatic ring system with each other and / or with the ring bonded to the groups.

[0059] In some preferred embodiments, the first light emitter E1 comprises a structure represented by the following chemical formula (I-1a) or (I-2a):

[0060]

[0061] Among them, Ar 1 -Ar 5 X 1 X 2 R 1 -R 5 The definition is as described above.

[0062] In some preferred embodiments, X 1 and X 2 Independently selected from O or S; in some more preferred embodiments, X 1 and X 2 All are O.

[0063] In some preferred embodiments, X 1 X2 At least one of them is empty; preferably both are empty, in which case the first luminescent body E1 is selected from structures containing the following chemical formulas (I-1b) or (I-2b):

[0064]

[0065] Among them, Ar 1 -Ar 5 R 1 -R 5 The definition is as described above.

[0066] In some preferred embodiments, X 1 X 2 At least one of them is a single bond; particularly preferred are both single bonds, in which case the first luminescent body E1 is selected from structures containing the following chemical formulas (I-1c) or (I-2c):

[0067]

[0068] Among them, Ar 1 -Ar 5 R 1 -R 5 The definition is as described above.

[0069] In some preferred embodiments, X 1 X 2 In each occurrence, the two-bridge basis is the same or different, and the preferred two-bridge basis includes:

[0070]

[0071]

[0072] Where: Z1-Z4 are defined the same as R above. 1 The dashed key represents a bond that is bonded to an adjacent structural unit.

[0073] For the purposes of this invention, aromatic ring systems contain 5 to 10 carbon atoms, and heteroaromatic ring systems contain 1 to 10 carbon atoms and at least one heteroatom, provided that the total number of carbon atoms and heteroatoms is at least 4. The heteroatom is preferably selected from Si, N, P, O, S, and / or Ge, and particularly preferably from Si, N, P, O, and / or S. For the purposes of this invention, aromatic or heteroaromatic ring systems not only include systems containing aryl or heteroaromatic groups, but also in which multiple aryl or heteroaromatic groups can be interrupted by short non-aromatic units (<10% non-H atoms, preferably less than 5% non-H atoms, such as C, N, or O atoms). Therefore, systems such as 9,9′-spirodifluorene, 9,9-diarylfluorene, triarylamines, and diaryl ethers are also considered aromatic ring systems for this purpose.

[0074] In some preferred embodiments, Ar in the first light emitter E1 1 -Ar 5 The same or different ones, in each occurrence, are selected from aromatic or heteroaromatic groups having 5 to 20 ring atoms; preferably selected from aromatic or heteroaromatic groups having 5 to 18 ring atoms; even better selected from aromatic or heteroaromatic groups having 5 to 15 ring atoms; and best selected from aromatic or heteroaromatic groups having 5 to 10 ring atoms; they may be unsubstituted or substituted with one or two R atoms. 1 Group substitution. Preferred aryl or heteroaryl groups include benzene, naphthalene, anthracene, phenanthrene, pyridine, dianaphthalene, or thiophene.

[0075] In some preferred embodiments, Ar 1 -Ar 5 Selected from the following structural formula:

[0076]

[0077] Where: X 3 It is CR 101 Or N; Y1 is selected from NR 101 CR 102 R 103 SiR 104 R 105 C (=O), S or O; R 101 -R 105 The definition of R is the same as above. 1 .

[0078] Furthermore, Ar 1 Ar 2 Ar 3 Ar 4 Ar 5 It is independently selected from one or a combination of the following chemical structural formulas, and may be further substituted in any way:

[0079]

[0080] In some particularly preferred embodiments, Ar 1 -Ar 5 It is a phenyl group.

[0081] In some preferred embodiments, Ar 4 Ar 5 At least one of them is empty; preferably both are empty, in which case the first luminescent body E1 comprises the structure shown by the following chemical formula (I-1d) or (I-2d) or (I-1e) or (I-2e):

[0082]

[0083] Among them, Ar 1 -Ar 3 X a Y b R 3 -R 5 The definition is as described above.

[0084] Prioritized, X in chemical formulas (I-1d) and (I-1e) a Selected independently from N(R) whether they are the same or different 6 ), C(R 6 R 7 ), Si(R) 6 R 7 ), O or S.

[0085] Preferred, Y in chemical formulas (I-2d) and (I-2e) b They are selected independently from C=O, O, S, P(=O)R, whether identical or different. 6 S = O or SO2; with particular preference, C = O is selected.

[0086] In some other preferred embodiments, the first light emitter E1 comprises the structure shown by the following chemical formulas (I-1f)-(I-1i):

[0087]

[0088] Among them, Y c Can be the same or different from O or S; Ar 1 -Ar 3 X a R 3 -R 5 The definition is as described above.

[0089] In some particularly preferred embodiments, the above-mentioned Ar 2 Ar3 The following structural units are preferred and can be arbitrarily replaced:

[0090]

[0091] In some preferred embodiments, according to the structural units of chemical formula (I-1)-(I-1i) and chemical formula (I-2)-(I-2e), wherein R 1 -R 5 When appearing multiple times, the following structural units or combinations thereof may be included, either identically or differently:

[0092]

[0093] Where n0 is 1, 2, 3, or 4.

[0094] In a preferred embodiment, the first light emitter E1 is selected from chemical formulas (I-1), (I-1a)-(I-1i).

[0095] In some particularly preferred embodiments, the first light emitter E1 has the structure shown in the following chemical formulas (I-1j)-(I-1l):

[0096]

[0097] Where: Y c The definition is as described above; R 201 -R 205 It can be H, D, or a straight-chain alkyl, alkoxy, or thioalkoxy group having 1 to 20 carbon atoms; or a branched or cyclic alkyl, alkoxy, thioalkoxy, or silyl group having 3 to 20 carbon atoms; or a substituted ketone group having 1 to 20 carbon atoms; or an alkoxycarbonyl group having 2 to 20 carbon atoms; or an aryloxycarbonyl group having 7 to 20 carbon atoms; or a cyano group (-CN) or a carbamoyl group (-C(=O)NH2). Haloformyl groups (-C(=O)-X where X represents a halogen atom), formyl groups (-C(=O)-H), isocyanate groups, isocyanate groups, thiocyanate groups, isothiocyanate groups, hydroxyl groups, nitro groups, CF3, Cl, Br, F, crosslinkable groups, or substituted or unsubstituted aromatic or heteroaromatic ring systems having 5 to 40 ring atoms, or aryloxy or heteroaryloxy groups having 5 to 40 ring atoms, or combinations of these groups, wherein one or more of the groups R 201 -R 205The rings can form monocyclic or polycyclic aliphatic or aromatic ring systems with each other and / or with the said groups; m and n are independently selected from any integer from 0 to 4; o and q are independently selected from any integer from 0 to 5; p is independently selected from any integer from 0 to 3. Preferably, R 201 -R 205 At least one of them contains an alcohol-soluble or water-soluble group;

[0098] Preferred, R 201 -R 205 It can be H, D, or a straight-chain alkyl, alkoxy, or thioalkoxy group having 1 to 10 carbon atoms, or a branched or cyclic alkyl, alkoxy, thioalkoxy, or silyl group having 3 to 10 carbon atoms, or a substituted ketone group having 1 to 10 carbon atoms, or an alkoxycarbonyl group having 2 to 10 carbon atoms, or an aryloxycarbonyl group having 7 to 10 carbon atoms, or a cyano group (-CN), a carbamoyl group (-C(=O)NH2), or a haloformyl group (-C(=O)-X). Wherein X represents a halogen atom, a formyl group (-C(=O)-H), an isocyanate group, an isocyanate group, a thiocyanate group, an isothiocyanate group, a hydroxyl group, a nitro group, CF3, Cl, Br, F, a crosslinkable group, or a substituted or unsubstituted aromatic or heteroaromatic ring system having 5 to 20 ring atoms, or an aryloxy or heteroaryloxy group having 5 to 20 ring atoms, or a combination of these groups, wherein one or more of the groups may form a monocyclic or polycyclic aliphatic or aromatic ring system with each other and / or with the rings bonded to the groups.

[0099] In some more preferred embodiments, the above-mentioned R 201 -R 205 At least one of the structures is selected from that described in equation (X):

[0100]

[0101] Among them, neither ring B nor ring C exists, or at least one of them exists;

[0102] Rings A, B, C, D, and E are independently selected from substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, or substituted or unsubstituted fused ring structures; W is selected from C(R1,R2), NR3, P, P=O, or Al.

[0103] V is selected from CR4 or N; the definitions of R1-R4 are the same as those of R above. 1 .

[0104] In some further preferred embodiments, the structure described in formula (X) above is selected from the structures described in formulas (Y-1) to (Y-3):

[0105]

[0106] In some further preferred embodiments, the structure described in formula (X) above is selected from the structures described in formulas (Z-1) to (Z-7):

[0107]

[0108] In a preferred embodiment, the second light emitter E2 is selected from MR-TADF material.

[0109] Furthermore, the second luminescent body E2 is preferably selected from chemical formulas (I-1) or (I-2), (I-1a)-(I-1l) or (I-2a)-(I-2e); particularly preferred from (I-1), chemical formulas (I-1a)-(I-1l); more preferably from chemical formulas (I-1j)-(I-1l), wherein R 201 -R 205 The preferred formulas are (X), (Y-1)-(Y-3), and (Z-1)-(Z-7).

[0110] In other embodiments, the second luminescent body E2 is selected from conventional fluorescent luminescent bodies (i.e., singlet luminescent bodies); conventional singlet luminescent bodies often have a long conjugated π-electron system. Numerous examples have been made to date, such as styrene amines and their derivatives disclosed in JP2913116B and WO2001021729A1, indofluorene and its derivatives disclosed in WO2008 / 006449 and WO2007 / 140847, and triarylamine derivatives of pyrene disclosed in US7233019 and KR2006-0006760.

[0111] In some preferred embodiments, the first light emitter E1 may be selected from monostyreneamine, distyreneamine, tristyreneamine, tetrastyreneamine, styrenephosphine, styrene ether, and aromatic amine.

[0112] A monostyrene amine refers to a compound comprising an unsubstituted or substituted styrene group and at least one amine, preferably an aromatic amine. A distyrene amine refers to a compound comprising two unsubstituted or substituted styrene groups and at least one amine, preferably an aromatic amine. A ternarystyrene amine refers to a compound comprising three unsubstituted or substituted styrene groups and at least one amine, preferably an aromatic amine. A tetrastyrene amine refers to a compound comprising four unsubstituted or substituted styrene groups and at least one amine, preferably an aromatic amine. A preferred styrene is stilbene, which may be further substituted. The definitions of the corresponding phosphines and ethers are similar to those for amines. An aryl amine or aromatic amine refers to a compound comprising three unsubstituted or substituted aromatic rings or heterocyclic systems directly linked to nitrogen. At least one of these aromatic or heterocyclic ring systems is preferably a fused ring system and preferably has at least 14 aromatic ring atoms. Preferred examples include aromatic anthracene amines, aromatic anthracene diamines, aromatic pyrene amines, aromatic pyrene diamines, aromatic trehalamines, and aromatic trehalamines. An aromatic anthracene amine refers to a compound in which one diarylamine group is directly attached to anthracene, preferably at the 9-position. An aromatic anthracene diamine refers to a compound in which two diarylamine groups are directly attached to anthracene, preferably at the 9 or 10 positions. The definitions of aromatic pyrene amines, aromatic pyrene diamines, aromatic trehalamines, and aromatic trehaline diamines are similar, wherein the diarylamine group is preferably attached to the 1 or 1,6 positions of pyrene.

[0113] Examples, and preferred examples, of conventional singlet luminescent emitters based on ethyleneamine and aromatic amines can be found in the following patent documents: WO2006 / 000388, WO2006 / 058737, WO2006 / 000389, WO2007 / 065549, WO2007 / 115610, US7250532B2, DE102005058557A1, CN1583691A, JP08053397A, US6251531B1, US2006 / 210830A, EP1957606A1, and US2008 / 0113101A1. The entire contents of the patent documents listed above are hereby incorporated herein by reference.

[0114] Examples of traditional singlet luminescent materials based on isostyrene and its derivatives include US5121029.

[0115] Furthermore, preferred conventional singlet luminescent materials may be indene-fluorene-amine and indene-fluorene-diamine, as disclosed in WO2006 / 122630, benzo[a]indene-amine and benzo[a]indene-diamine, as disclosed in WO2008 / 006449, and dibenzo[a]indene-amine and dibenzo[a]indene-diamine, as disclosed in WO2007 / 140847.

[0116] Further preferred conventional singlet luminescent materials can be selected from fluorene-based fused ring systems, such as those disclosed in US2015333277A1, US2016099411A1, and US2016204355A1.

[0117] More preferred conventional singlet luminescent materials may be pyrene derivatives, such as the structure disclosed in US2013175509A1; pyrene triarylamine derivatives, such as the pyrene triarylamine derivative containing a dibenzofuran unit disclosed in CN102232068B; or other pyrene triarylamine derivatives with specific structures, such as those disclosed in CN105085334A and CN105037173A. Other materials that can be used as singlet luminescent materials are polycyclic aromatic hydrocarbons, especially derivatives of the following compounds: anthracene such as 9,10-di(2-naphthyl)anthracene, naphthalene, tetraphenylene, xanthracene, phenanthrene, pyrene (such as 2,5,8,11-tetra-t-butylperylene), indene, benzo[a]pyrene, benzo[b]pyrene such as (4,4'-bis(9-ethyl-3-carbazovinyl)-1,1'-biphenyl), diindene, decacyclic ethylene, hexabenzobenzene, fluorene, spirodifluorene, arylpyrene (such as US20060222886), and aromatic ethylene (such as US5121). 029, US5130603), cyclopentadiene such as tetraphenylcyclopentadiene, rubrene, coumarin, rhodamine, quinacridone, pyrans such as 4-(dicyanomethylene)-6-(4-p-dimethylaminostyryl-2-methyl)-4H-pyran (DCM), thiorans, bis(acrazinyl)imine boron compounds (US2007 / 0092753A1), bis(acrazinyl)methylene compounds, carbostyryl compounds, oxazinones, benzoxazole, benzothiazole, benzimidazole, and pyrrolopyrrolediones. Materials for some conventional singlet luminescent materials can be found in the following patent documents: US20070252517A1, US4769292, US6020078. The entire contents of the aforementioned patent documents are hereby incorporated herein by reference.

[0118] In some embodiments, for stability reasons, the second luminescent material E2 is not selected from thermally excited delayed fluorescence (TADF) compounds having a DA structure, nor from compounds having aggregation-induced emission (AIE) properties.

[0119] In another preferred embodiment, the second luminescent body E2 is selected from any one of the chemical formulas (II-1)-(II-18):

[0120]

[0121]

[0122] Wherein: R0-R3, each time they appear, may be selected from H, D, or straight-chain alkyl, haloalkyl, alkoxy, or thioalkoxy groups having 1 to 20 carbon atoms, or branched or cyclic alkyl, haloalkyl, alkoxy, thioalkoxy, or silyl groups having 3 to 20 carbon atoms, or substituted ketone groups having 1 to 20 carbon atoms, or alkoxycarbonyl groups having 2 to 20 carbon atoms, or aryloxycarbonyl groups having 7 to 20 carbon atoms, or cyano groups, carbamoyl groups, halocarbamoyl groups, or formyl groups. The following groups may be used: isocyanate groups, isocyanate groups, thiocyanate groups, isothiocyanate groups, hydroxy groups, nitro groups, CF3, Cl, Br, F, I, crosslinkable groups, or substituted or unsubstituted aromatic or heteroaromatic ring systems having 5 to 40 ring atoms, or aryloxy or heteroaryloxy groups having 5 to 40 ring atoms, or arylamine or heteroarylamine groups having 5 to 40 ring atoms, disubstituted units at any position of the above groups, or combinations of these groups, wherein one or more groups may form monocyclic or polycyclic aliphatic or aromatic ring systems with each other and / or with the rings bonded to the groups.

[0123] When Ar1-Ar4 appear multiple times, they may be selected from aromatic or heteroaromatic groups having 5 to 60 ring atoms, either identically or differently; preferably selected from aromatic or heteroaromatic groups having 6 to 40 ring atoms; more preferably selected from aromatic or heteroaromatic groups having 6 to 30 ring atoms; and most preferably selected from aromatic or heteroaromatic groups having 6 to 20 ring atoms.

[0124] For the purposes of this invention, any H atom on the first light emitter E1 and the second light emitter E2 is subjected to R 1 Group substitution, R 1 As defined above, preferably, (1) C1-C10 alkyl, particularly preferably, refers to the following groups: methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclobutyl, 2-methylbutyl, n-pentyl, n-hexyl, cyclohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-methylheptyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, vinyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclo (1) Hexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl, ethynyl, propynyl, butynyl, pentyynyl, hexynyl, and octyynyl; (2) C1-C10 alkoxy, particularly preferably methylbutoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, or 2-methylbutoxy; (3) C2 to C10 aryl or heteroaryl, which may be monovalent or divalent depending on the application, and in each case may be R of the aforementioned groups. 1Substitution and attachment to aromatic or heteroaromatic rings at any desired position are particularly preferred, including: benzene, naphthalene, anthracene, dianaminate, dihydropyrene, chlorophenanthrene, fluoranthene, butanthene, pentane, benzo[a]pyrene, furan, benzo[a]furan, isobenzo[a]furan, dibenzo[a]furan, thiophene, benzo[a]thiophene, isobenzo[a]thiophene, thiofluorene, pyrrole, indole, isoindole, carbazole, pyridine, quinoline, isoquinoline, acridine, phenanthridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline, phenothiazine, phenotoxazine, pyrazole, indazole, imidazole, benzimidazole, naphthiazole, phenanthreneimidazole, pyridinium pyridimazole, pyrazinium pyridimazole, quinoxaline pyridimazole, oxazole, benzo[a]oxazole, naphthiazole, anthraquinone pyridimazole, phenanthrene pyridimazole, isoxazole, 1,2- Thiazole, 1,3-thiazole, benzothiazole, pyridazine, benzopyridazine, pyrimidine, benzopyrimidine, quinoxaline, pyrazine, diazanthracene, 1,5-diazanaphthalene, nitrocarbazole, benzocarbline, phenanthroline, 1,2,3-triazole, 1,2,4-triazole, benzotriazole, 1,2,3-oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,3,4- Oxadiazole, 1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole, 1,3,5-triazine, 1,2,4-triazine, 1,2,3-triazine, tetrazolium, 1,2,4,5-tetraazine, 1,2,3,4-tetraazine, 1,2,3,5-tetraazine, purine, pteridine, indene, and benzothiadiazole. For the purposes of this invention, aromatic and heteroaromatic ring systems are considered to include, in particular, biphenylene, terphenylene, fluorene, spirofluorene, dihydrophenanthrene, tetrahydropyrene, and cis or trans indenefluorene, in addition to the aryl and heteroaromatic groups mentioned above.

[0125] In this embodiment of the invention, for the energy level structure of organic materials, the triplet energy level (E T1 and singlet energy levels (E) S1 The HOMO, LUMO, and resonance factor intensity f play a crucial role. The determination of these parameters is introduced below.

[0126] HOMO and LUMO energy levels can be measured using the photoelectric effect, such as XPS (X-ray photoelectron spectroscopy) and UPS (ultraviolet photoelectron spectroscopy), or cyclic voltammetry (CV). Recently, quantum chemical methods, such as density functional theory (DFT), have also become effective methods for calculating molecular orbital energy levels.

[0127] triplet energy level E of organic materials T1 The energy levels can be measured by low-temperature time-resolved emission spectra or obtained through quantum simulation calculations (such as Time-dependent DFT), for example, using commercial software Gaussian 09W (Gaussian Inc.). Specific simulation methods are described below. The singlet energy level E of organic materials...S1 It can be determined by absorption spectrum or emission spectrum, or by quantum simulation calculation (such as Time-dependent DFT); the resonance factor intensity f can also be obtained by quantum simulation calculation (such as Time-dependent DFT).

[0128] It should be noted that HOMO, LUMO, and E T1 and E S1 The absolute value depends on the measurement or calculation method used. Even for the same method, different evaluation methods, such as those at the starting point and peak point on the CV curve, can give different HOMO / LUMO values. Therefore, a reasonable and meaningful comparison should be made using the same measurement method and the same evaluation method. In the description of the embodiments of this invention, HOMO, LUMO, and E are used... T1 and E S1 The value is based on a simulation of the Time-dependent DFT, but does not affect the application of other measurement or calculation methods.

[0129] In some preferred embodiments, according to the first light emitter E1 of the present invention, its (E S1 -E T1 ≤0.65eV, preferably ≤0.55eV, even better ≤0.45eV, even better ≤0.35eV, and best ≤0.3eV.

[0130] In some other preferred embodiments, according to the first light emitter E1 of the present invention, its (E S1 -E T1 ≤0.25eV, preferably ≤0.20eV, even better ≤0.15eV, and most preferably ≤0.10eV.

[0131] In some embodiments, the mixture, wherein the first luminescent body E1 and the second luminescent body E2 are small molecules or polymers, preferably small molecules.

[0132] In a preferred embodiment, the mixture does not contain any resin.

[0133] Furthermore, in this invention, the H atom or CH2 group on a separate aromatic ring or heteroaromatic ring can be replaced by a group R. R is selected from alkyl groups having 1 to 40 carbon atoms, preferably from the following groups: methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclobutyl, methylbutyl, n-pentyl, sec-pentyl, cyclopentyl, n-hexyl, cyclohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, ethylhexyl, trifluoromethyl, pentafluoroethyl, trifluoroethyl, vinyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl, ethynyl, propynyl, butynyl, penynyl, hexynyl, and ocynyl; alkoxy groups having 1 to 40 carbon atoms, such as methoxy, trifluoromethoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, or methylbutoxy.

[0134] One object of the present invention is to provide a material solution for vapor-deposited OLEDs.

[0135] In a preferred embodiment, in the mixture, the first host material H1, the second host material H2, the first luminescent body E1, or the second luminescent body E2 are at least partially deuterated, preferably 10% or more of the H are deuterated, more preferably 20% or more of the H are deuterated, most preferably 30% or more of the H are deuterated, and most preferably 40% or more of the H are deuterated.

[0136] Examples of the first light emitter E1 and the second light emitter E2 are given below, but are not limited to:

[0137]

[0138]

[0139]

[0140]

[0141]

[0142] The following is a further example of the second luminescent material E2 according to chemical formula (II-1)-(II-18):

[0143]

[0144]

[0145]

[0146]

[0147] According to the mixture of the present invention, the absorption spectrum of the second light emitter E2 and the emission spectrum of the first light emitter E1 have a large overlap, and a relatively efficient energy transfer can be achieved between them.

[0148] In some preferred embodiments, the peak value (λ2) of the absorption spectrum of the second emitting element E2 is on the side of the shorter wavelength of the peak value (λ1) of the emission spectrum of the first emitting element E1, and there is a large overlap.

[0149] In other embodiments, the peak value (λ2) of the absorption spectrum of the second light emitter E2 is on the side of the longer wavelength of the peak value (λ1) of the emission spectrum of the first light emitter E1, and there is a large overlap.

[0150] Preferably, the difference between λ1 and λ2 is ≤10nm, more preferably ≤8nm, even better ≤5nm, particularly preferably ≤3nm, and most preferably ≤2nm.

[0151] In some other preferred embodiments, the peak value (λ2) of the absorption spectrum of the second emitting element E2 is between the peak value (λ1) of the emission spectrum of the first emitting element E1 and the peak value (λ3) of the absorption spectrum of the first emitting element E1.

[0152] In some embodiments, the peak value (λ1) of the emission spectrum of the first light emitter E1 is between the peak value (λ2) of the absorption spectrum of the second light emitter E2 and the peak value (λ3) of the absorption spectrum of the first light emitter E1.

[0153] In some preferred embodiments, the mixture emits a light spectrum entirely from the second emitter E2, meaning that complete energy transfer is achieved between the first emitter E1 and the second emitter E2.

[0154] In some embodiments, the peak value (λ4) of the emission spectrum of the second light emitter E2 is between 400 nm and 800 nm, preferably between 450 nm and 750 nm, and most preferably between 450 nm and 700 nm.

[0155] In a preferred embodiment, the peak value (λ4) of the second light emitter E2 emission spectrum is between 450 nm and 460 nm.

[0156] In another preferred embodiment, the peak value (λ4) of the second light emitter E2 emission spectrum is between 520 nm and 535 nm.

[0157] In another preferred embodiment, the peak value (λ4) of the second light emitter E2 emission spectrum is between 600 nm and 640 nm.

[0158] In some preferred embodiments, the weight ratio between the first light emitter E1 and the second light emitter E2 in the mixture is from 10:90 to 90:10, preferably from 20:80 to 80:20, more preferably from 70:30 to 30:70, particularly preferably from 60:40 to 40:60, and most preferably from 55:45 to 45:55.

[0159] In a preferred embodiment, the lowest unoccupied orbital energy level (LUMO) of the first host material H1 is higher than that of the second host material H2.

[0160] In a preferred embodiment, the mixture, wherein the first host material H1 and the second host material H2 form a type II heterojunction structure, wherein the highest occupied orbital level (HOMO) (H1) of the first host material H1 is higher than the HOMO (H2) of the second host material H2, and the lowest unoccupied orbital level (LUMO) (H1) of the first host material H1 is higher than the LUMO (H2) of the second host material H2. In some embodiments, the band gap of the first host material H1 is smaller than that of the second host material H2. In some more preferred embodiments, the band gap of the first host material H1 is larger than that of the second host material H2.

[0161] In some embodiments, the mixture has HOMO(H1)≥HOMO(H2)+0.10eV and / or LUMO(H1)≥LUMO(H2)+0.10eV.

[0162] In a preferred embodiment, the mixture has HOMO(H1)≥HOMO(H2)+0.20eV and / or LUMO(H1)≥LUMO(H2)+0.20eV.

[0163] In a more preferred embodiment, the mixture has HOMO(H1)≥HOMO(H2)+0.25eV and / or LUMO(H1)≥LUMO(H2)+0.25eV.

[0164] In a most preferred embodiment, the mixture has HOMO(H1)≥HOMO(H2)+0.30eV and / or LUMO(H1)≥LUMO(H2)+0.30eV.

[0165] In some embodiments, the first host material H1 and the second host material H2, their E ex =min[LUMO(H1)-HOMO(H2),LUMO(H1)-HOMO(H2)]≤min[E T1 (H1),E T1[(H2)]+0.2eV, where HOMO(H1), LUMO(H1) and E T1 (H1) represents the highest occupied orbital, the lowest unoccupied orbital, and the triplet energy level of the first host material H1, respectively, HOMO(H2), LUMO(H2), and E. T1 (H2) represents the highest occupied orbital, the lowest unoccupied orbital, and the triplet energy level of the second host material H2, respectively.

[0166] In a preferred embodiment, E ex ≤min[E T1 (H1), E T1 (H2)]+0.1eV, more preferably ≤min[E T1 (H1), E T1 (H2)], especially preferred is ≤min[E T1 (H1), E T1 (H2)]-0.1eV, the optimal value is ≤min[E T1 (H1), E T1 [(H2)]-0.2eV.

[0167] In some embodiments, E ex ≥2.6eV, E is preferred ex ≥2.7eV, E is better ex ≥2.75eV, with particular advantage being E ex ≥2.8eV, the optimal value is E ex ≥2.85eV.

[0168] In a preferred embodiment, the mixture wherein the first host material H1 is selected from chemical formula (III-1) or (III-2); and / or the second host material H2 is selected from chemical formula (IV):

[0169]

[0170] Among them: Z 101 -Z 103 Selected independently from N or CR 12 And at least one of them is selected from N; L1-L3 are selected from single bonds, or substituted or unsubstituted aromatic or heteroaromatic groups with 6 to 30 ring atoms; Ar 6 -Ar 11 Selected from substituted or unsubstituted aromatic or heteroaromatic groups having 5 to 40 ring atoms, or aryloxy or heteroaryloxy groups having 5 to 40 ring atoms, or combinations of these groups, wherein one or more groups may form a monocyclic or polycyclic aliphatic or aromatic ring system with each other and / or with the rings bonded to the groups; R 8 -R12 The definition of R is as described above. 1 n1, n3, and n4 are each independently selected from integers from 0 to 7; n2 is selected from integers from 0 to 8.

[0171] In another preferred embodiment, the first host material H1 is selected from chemical formula (III-3):

[0172]

[0173] Ar 12 Ar 13 Ar 14 Ar 15 Each can be used to independently represent an aromatic group or a heterocyclic aromatic group with 5 to 30 ring atoms;

[0174] X1 represents a single bond, N(R) 15 ), C(R 15 )2、Si(R 15 )2、O、C=N(R 15 ), C = C(R) 15 )2、P(R 15 ), P(=O)R 15 S, S = O or SO2; X2 and X3 independently represent single bonds and N(R) bonds, respectively. 15 ), C(R 15 )2、Si(R 15 )2、O、C=N(R 15 ), C = C(R) 15 2. P(R) 15 ), P(=O)R 15 S, S = O or SO2, but X2 and X3 are not simultaneously single bonds; R 13 R 14 R 15 Each of these groups independently represents H, D, F, CN, alkenyl, alkynyl, amino, nitro, acyl, alkoxy, carbonyl, sulfone, alkyl with 1–30 carbon atoms, cycloalkyl with 3–30 carbon atoms, or aromatic hydrocarbon or heterocyclic group with 5–60 ring atoms, wherein R 13 R 14 The connection site can be any carbon atom on the fused ring, and is controlled by R. 13 R 14 There can be any number of carbon atoms that are substituted.

[0175] In a preferred embodiment, the first host material H1 is selected from any one of chemical formula (III-1a), chemical formula (III-1b), or chemical formula (III-2a):

[0176]

[0177]

[0178] In a particularly preferred embodiment, the first host material H1 is selected from chemical formula (III-1a) or chemical formula (III-2a).

[0179] In a preferred embodiment, the first host material H1 is selected from chemical formulas (III-3a) to (III-3e).

[0180]

[0181] Where X4 represents N(R) 15 ), C(R 15 )2、Si(R 15 )2、O、C=N(R 15 ), C = C(R) 15 )2、P(R 15 ), P(=O)R 15 S, S = O or SO2; X4 is preferably derived from N(R) 15 ) or O; Ar 15 R 15 The definition is the same as described above.

[0182] In some preferred embodiments, the above-mentioned Ar 6 Ar 7 Ar 8 Each is independently represented as a substituted or unsubstituted aromatic group or heterocyclic group having a ring atom number of 5 to 30; in a more preferred embodiment, Ar 6 Ar 7 Ar 8 Each is independently represented as a substituted or unsubstituted aromatic group or heterocyclic group having a ring atom number of 5 to 20; in the most preferred embodiment, Ar 6 Ar 7 Ar 8 Each is represented independently as an aromatic group or heterocyclic group having 5 to 15 substituted or unsubstituted ring atoms.

[0183] In some preferred embodiments, the above-mentioned Ar 6 Ar 7 Ar 8 Ar 15 It may contain one or more combinations of the following structural groups:

[0184]

[0185] Among them, A 1 A 2 A3 A 4 A 5 A 6 A 7 A 8 CR are represented independently. 16 Or N;

[0186] W 1 W 2 Selected independently from C(R) 17 R 18 ), Si(R) 17 R 18 ), NR 16 C (=O), S or O;

[0187] R 16 R 17 R 18 Each time it appears, it may be the same or different selected from H, D, or straight-chain alkyl, alkoxy or thioalkoxy having 1 to 20 C atoms, or branched or cyclic alkyl, alkoxy, thioalkoxy or silyl having 3 to 20 C atoms, or ketone having 1 to 20 C atoms, or alkoxycarbonyl having 2 to 20 C atoms, or aryloxycarbonyl having 7 to 20 C atoms, or cyano, carbamoyl, haloformyl, formyl, isocyano, isocyanate, thiocyanate, isothiocyanate, hydroxyl, nitro, CF3, Cl, Br, F, crosslinkable groups, or substituted or unsubstituted aromatic or heteroaromatic ring systems having 5 to 40 ring atoms, or aryloxy or heteroaromatic groups having 5 to 40 ring atoms, or combinations of these groups, wherein one or more groups may form monocyclic or polycyclic aliphatic or aromatic ring systems with each other and / or with the rings bonded to the groups.

[0188] In a more preferred embodiment, the above-mentioned Ar 6 Ar 7 Ar 8 Ar 15 It contains one of the following structural groups, wherein the H on the ring can be arbitrarily substituted:

[0189]

[0190] Furthermore, the aforementioned Ar 6 Ar 7 Ar 8 Ar 15It is selected from benzene, biphenyl, naphthalene, anthracene, phenanthrene, pyrene, pyridine, pyrimidine, triazine, fluorene, thiofluorene, silylfluorene, carbazole, thiophene, furan, thiazole, triphenylamine, triphenylphosphine oxide, tetraphenylsilane, spirofluorene, spirosilylfluorene, etc., and any combination thereof; more preferably, it is selected from benzene, biphenyl, pyridine, pyrimidine, triazine, furan, carbazole, etc., and any combination thereof.

[0191] In a preferred embodiment, Ar in chemical formula (III-2) or chemical formula (III-2a) 7 Or Ar 8 It contains an electron-withdrawing group, especially a weak electron-withdrawing group, preferably from pyridine, pyrimidine or pyrazine.

[0192] In a preferred embodiment, n1, n3, n4 are 0, meaning there is no corresponding substitution.

[0193] In some preferred embodiments, R 8 -R 18 The groups are independently selected from H, D, CN, substituted or unsubstituted alkyl groups having 1 to 18 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 18 carbon atoms, substituted or unsubstituted aromatic hydrocarbon groups having 5 to 30 aromatic heterocyclic groups; in a more preferred embodiment, R 8 -R 18 Each of the following groups independently represents H, D, an alkyl group with 1 to 12 substituted or unsubstituted carbon atoms, or an aromatic hydrocarbon group or an aromatic heterocyclic group with 5 to 20 substituted or unsubstituted ring atoms; in the most preferred embodiment, R 8 -R 18 Each of the following can be independently represented: H, D, alkyl group with 1 to 6 substituted or unsubstituted carbon atoms, aromatic hydrocarbon group or aromatic heterocyclic group with 5 to 15 substituted or unsubstituted ring atoms.

[0194] In some embodiments, E T1 (H1)≥2.7eV, preferably ≥2.8eV, more preferably ≥2.85eV, and most preferably ≥2.9eV.

[0195] In a preferred embodiment, the HOMO of the first host material H1 is ≤-5.7 eV, preferably ≤-5.8 eV, and most preferably ≤-5.9 eV.

[0196] In some other preferred embodiments, the ΔHOMO of the first host material H1 is ≥0.2 eV, preferably ≥0.3 eV, more preferably ≥0.35 eV, and most preferably ≥0.4 eV.

[0197] In a preferred embodiment, the excitocomplex formed between the first host material H1 and the second host material H2 has a singlet energy level E. S1 and triplet energy level ET1 The difference is ≤0.3eV, better is ≤0.25eV, even better is ≤0.2eV, and especially better is ≤0.15eV.

[0198] In another preferred embodiment, the excitocomplex formed between the first host material H1 and the second host material H2 has a triplet energy level E T1 ≥2.6eV, preferably ≥2.7eV, even better ≥2.75eV, and most preferably ≥2.8eV.

[0199] In other embodiments, the excitocomplex formed between the first host material H1 and the second host material H2 has a triplet energy level E T1 ≥2.2eV, preferably ≥2.3eV, even better ≥2.4eV, and most preferably ≥2.5eV.

[0200] Examples of preferred first host materials H1 according to chemical formulas (III-1), (III-2), (III-3), (III-1a), (III-1b), (III-2a), (III-3a)-(III-3e) are shown below, but are not limited to:

[0201]

[0202]

[0203]

[0204]

[0205]

[0206]

[0207] In some preferred embodiments, the second host material H2 is selected from chemical formula (IV), wherein: Ar 9 -Ar 11 Each group is independently selected from one of the formulas (V-1) to (V-7):

[0208]

[0209]

[0210] Where: W1-W2 are selected from O, S, or Se; m1 is an integer from 0 to 3, m2 is an integer from 0 to 4, and m3 is an integer from 0 to 5; R 101 -R 116 The definition of R is as described above. 1 .

[0211] In some preferred embodiments, L1-L3 are selected from single bonds or the following groups or combinations thereof:

[0212]

[0213] Among them: A 10 Each time it appears, it is selected independently from CR. 19 Or N; X5 is independently selected from NR 20 , O, S or Se; R 19 -R 20 Each time it appears, it is independently selected from: H, D, or a straight-chain alkyl group having 1 to 20 carbon atoms, or a straight-chain alkoxy group having 1 to 20 carbon atoms, or a straight-chain thioalkoxy group having 1 to 20 carbon atoms, or a branched or cyclic alkyl group having 3 to 20 carbon atoms, or a branched or cyclic alkoxy group having 3 to 20 carbon atoms, or a branched or cyclic thioalkoxy group having 3 to 20 carbon atoms, silyl group, a ketone group having 1 to 20 carbon atoms, or an alkoxycarbonyl group having 2 to 20 carbon atoms. Or an aryloxy carbonyl group, cyano group, carbamoyl group, haloformyl group, formyl group, isocyano group, isocyanate group, thiocyanate group, isothiocyanate group, hydroxy group, nitro group, CF3 group, Cl group, Br group, F group, crosslinkable group having 7 to 20 carbon atoms, or a substituted or unsubstituted aromatic group having 5 to 60 ring atoms, or a substituted or unsubstituted heteroaromatic group having 5 to 60 ring atoms, or an aryloxy group having 5 to 60 ring atoms, or a heteroaryloxy group having 5 to 60 ring atoms, or a combination of these groups.

[0214] In some preferred embodiments, L1-L3 are selected from the following groups or combinations thereof:

[0215]

[0216] The asterisk (*) indicates the bond position, and the H atoms on the ring can be further substituted.

[0217] In some preferred embodiments, the energy difference ΔE between the singlet and triplet levels of the second host material H2 ST ≤0.50eV, preferably ≤0.40eV, even better ≤0.30eV, and most preferably ≤0.20eV.

[0218] In some preferred embodiments, the triplet energy level E of the second host material H2 T1 ≥2.70eV, preferably ≥2.80eV, even better ≥2.85eV, and most preferably ≥2.90eV.

[0219] In other embodiments, the triplet energy level E of the second host material H2 T1≥2.30eV, preferably ≥2.40eV, even better ≥2.5eV, and most preferably ≥2.60eV.

[0220] In a preferred embodiment, the LUMO of the second host material H2 is ≤-2.7eV, preferably ≤-2.75eV, and most preferably ≤-2.8eV.

[0221] In some other preferred embodiments, the ΔLUMO of the second host material H2 is ≥0.2 eV, preferably ≥0.3 eV, more preferably ≥0.35 eV, and most preferably ≥0.4 eV.

[0222] In some preferred embodiments, the second host material H2 is of general formula (IV), wherein Z 101 -Z 103 All are selected from N.

[0223] In some preferred embodiments, Ar9-Ar 11 Each group is independently selected from one of the groups shown in formula (V-1), formula (V-3), formula (V-5), or formula (V-6).

[0224] In a preferred embodiment, Ar9-Ar 11 At least one of them is selected from formula (V-3).

[0225] In another preferred embodiment, Ar9-Ar 11 At least one of them is selected from formula (V-5).

[0226] In a preferred embodiment, Ar9-Ar 11 At least one of them is selected from formula (V-6).

[0227] The following examples illustrate specific instances of the second main material H2, but are not limited to these examples; it can be further arbitrarily replaced:

[0228]

[0229]

[0230] The H can be partially or completely replaced by D.

[0231] In some embodiments, the above-mentioned Ar 6 -Ar 11 Ar 15 R 8 -R 18 It may further include the following chemical formula (A):

[0232]

[0233] L4 is selected from single bonds or any divalent linking group; the dashed line represents a linking bond; Ar 16 -Ar 18 It is selected from substituted or unsubstituted aromatic or heteroaromatic groups having 5 to 30 ring atoms, or aryloxy or heteroaryloxy groups having 5 to 30 ring atoms, or combinations of these groups; preferably substituted or unsubstituted aromatic or heteroaromatic groups having 5 to 20 ring atoms, or aryloxy or heteroaryloxy groups having 5 to 20 ring atoms, or combinations of these groups; more preferably substituted or unsubstituted aromatic or heteroaromatic groups having 5 to 15 ring atoms, or aryloxy or heteroaryloxy groups having 5 to 15 ring atoms, or combinations of these groups.

[0234] In a highly preferred embodiment, the mixture is used as the light-emitting layer in an organic electroluminescent device. In some embodiments, there may be special requirements for the first host material H1 and the second host material H2 for stability or process considerations.

[0235] In a preferred embodiment, the mixture according to the invention comprises at least one of the first host material H1 and the second host material H2, wherein ((LUMO+1)-LUMO) ≥ 0.1 eV, preferably ≥ 0.15 eV, more preferably ≥ 0.20 eV, even more preferably ≥ 0.25 eV, and most preferably ≥ 0.30 eV.

[0236] In a preferred embodiment, the mixture according to the invention contains a second host material H2, wherein ((LUMO+1)-LUMO) ≥ 0.1 eV, preferably ≥ 0.15 eV, more preferably ≥ 0.20 eV, even more preferably ≥ 0.25 eV, and most preferably ≥ 0.30 eV.

[0237] In another preferred embodiment, the mixture according to the invention, wherein at least one of the first host material H1 and the second host material H2 has (HOMO-(HOMO-1)) ≥ 0.2 eV, preferably ≥ 0.25 eV, more preferably ≥ 0.30 eV, even more preferably ≥ 0.35 eV, and most preferably ≥ 0.40 eV.

[0238] In another preferred embodiment, the mixture according to the invention, wherein the first host material H1 has (HOMO-(HOMO-1)) ≥ 0.2 eV, preferably ≥ 0.25 eV, more preferably ≥ 0.30 eV, even more preferably ≥ 0.35 eV, and most preferably ≥ 0.40 eV.

[0239] In a preferred embodiment, the mixture wherein the molar ratio of the first host material H1 to the second host material H2 is from 2:8 to 8:2; a preferred molar ratio is from 3:7 to 7:3; and a more preferred molar ratio is from 4:6 to 6:4.

[0240] In a preferred embodiment, at least one of the first main material H1 and the second main material H2 in the mixture according to the invention has a glass transition temperature (Tg) ≥ 100°C; in a more preferred embodiment, at least one has a Tg ≥ 120°C; in a more preferred embodiment, at least one has a Tg ≥ 140°C; in a further more preferred embodiment, at least one has a Tg ≥ 160°C; and in a most preferred embodiment, at least one has a Tg ≥ 180°C.

[0241] In a preferred embodiment, in the mixture according to the present invention, both the first host material H1 and the second host material H2 are small molecule materials.

[0242] One object of the present invention is to provide a material solution for vapor-deposited OLEDs.

[0243] In a preferred embodiment, the mixture according to the invention is used in a vapor-deposited OLED device. For this purpose, the first host material H1 and the second host material H2 in the mixture according to the invention have a molecular weight ≤1000 g / mol, preferably ≤900 g / mol, very preferably ≤850 g / mol, more preferably ≤800 g / mol, and most preferably ≤700 g / mol.

[0244] Another objective of this invention is to provide a material solution for printed OLEDs.

[0245] For this purpose, in the mixture according to the invention, at least one of the first main material H1 and the second main material H2, preferably both, has a molecular weight ≥700 g / mol, preferably ≥800 g / mol, very preferably ≥900 g / mol, more preferably ≥1000 g / mol, and most preferably ≥1100 g / mol.

[0246] In solution-processed OLEDs, the physical properties of the two host materials can affect the printing process or film performance, thereby impacting device performance. These properties, besides molecular weight, melting point / Tg, and solubility, can also include other parameters such as molecular volume. Therefore, for printed OLEDs, preferred embodiments of the mixture according to the present invention include:

[0247] The difference in molecular weight between the first host material H1 and the second host material H2 is ≥50 Dalton, preferably ≥80 Dalton, more preferably ≥120 Dalton, most preferably ≥150 Dalton, or;

[0248] The difference in solubility of the first main material H1 and the second main material H2 in an organic solvent, such as toluene, shall not exceed 15%, more preferably not exceed 12%, particularly preferably not exceed 10%, and most preferably not exceed 5%, or;

[0249] The difference between the melting point or Tg of the first main material H1 and the second main material H2 shall not exceed 30K, preferably not exceed 20K, more preferably not exceed 15K, and most preferably not exceed 5K, or;

[0250] The difference in molecular volume between the first host material H1 and the second host material H2 is ≥20%, preferably ≥30%, more preferably ≥40%, and most preferably ≥45%.

[0251] In some embodiments, the difference in molecular volume between the first host material H1 and the second host material H2 is ≤30%, preferably ≤20%, and most preferably ≤10%.

[0252] In other embodiments, at least one of the first main material H1 and the second main material H2 in the mixture according to the invention, preferably both, has a solubility in toluene of ≥10 mg / mL at 25°C, preferably ≥12 mg / mL, more preferably ≥15 mg / mL, and most preferably ≥20 mg / mL.

[0253] The term "small molecule" as defined herein refers to a molecule that is not a polymer, oligomer, dendritic polymer, or blend. In particular, small molecules do not contain repeating structures. The molecular weight of a small molecule is ≤3000 g / mol, preferably ≤2000 g / mol, and most preferably ≤1500 g / mol.

[0254] Polymers include homopolymers, copolymers, and block copolymers. In this invention, polymers also include dendrimers; for information on the synthesis and application of dendrimers, please refer to [Dendrimers and Dendrons, Wiley-VCH Verlag GmbH & Co. KGaA, 2002, Ed. George R. Newkome, Charles N. Moorefield, Fritz Vogtle.].

[0255] A conjugated polymer is a polymer whose backbone is mainly composed of sp atoms of carbon atoms. 2 Hybrid orbitals are a common feature, with notable examples including polyacetylene and poly(phenylenevinylene). In these compounds, the carbon atoms in the main chain can be replaced by other non-carbon atoms, and when the sp atoms in the main chain... 2 Even when hybridization is disrupted by some natural defects, it is still considered a conjugated polymer. Furthermore, the conjugated polymers in this invention also include those whose main chain contains aryl amines, aryl phosphine, and other heterocyclic aromatics, organometallic complexes, etc.

[0256] In a particularly preferred embodiment, the mixture further comprises another organic functional material. This other organic functional material includes hole injection or transport materials (HIM / HTM), hole blocking materials (HBM), electron injection or transport materials (EIM / ETM), electron blocking materials (EBM), organic host materials, singlet luminescent materials (fluorescent materials), triplet luminescent materials (phosphorescent materials), organic thermally excited delayed fluorescence materials (TADF materials), and especially luminescent organometallic complexes. Various organic functional materials are described in detail, for example, in WO2010135519A1, US20090134784A1, and WO2011110277A1, the entire contents of which are hereby incorporated herein by reference. The organic functional material can be a small molecule or a polymer.

[0257] In some preferred embodiments, the mixture further comprises a light emitter selected from phosphorescent light emitters or TADF materials.

[0258] In a preferred embodiment, the mixture further comprises a phosphorescent emitter. The phosphorescent emitter is ≤20 wt% by weight, preferably ≤15 wt%, and more preferably ≤10 wt%.

[0259] Phosphorescent emitters are also known as triplet emitters. In a preferred embodiment, the phosphorescent emitter is a metal complex of the general formula M(L)n0, where M is a metal atom, L (which may appear the same or different times) is an organic ligand that is bonded or coordinated to the metal atom M at one or more sites, and n0 is an integer greater than 1, preferably 1, 2, 3, 4, 5, or 6. Optionally, these metal complexes are linked to a polymer at one or more sites, preferably through an organic ligand.

[0260] In a preferred embodiment, the metal atom M is selected from a transition metal element, a lanthanide element, or an actinide element, preferably Ir, Pt, Pd, Au, Rh, Ru, Os, Sm, Eu, Gd, Tb, Dy, Re, Cu, or Ag, particularly preferably Os, Ir, Ru, Rh, Re, Pd, or Pt, and most preferably Ir or Pt.

[0261] Generally, phosphorescent emitters contain chelating ligands, i.e., ligands that coordinate with a metal through at least two binding sites. Particularly preferred are triplet emitters containing two or three identical or different bidentate or polydentate ligands. Chelating ligands are beneficial for improving the stability of metal complexes.

[0262] Examples of organic ligands may be selected from phenylpyridine derivatives, 7,8-benzoquinoline derivatives, 2-(2-thienyl)pyridine derivatives, 2-(1-naphthyl)pyridine derivatives, or 2-phenylquinoline derivatives. All of these organic ligands may be substituted, for example, with fluorinated or trifluoromethyl groups. The auxiliary ligand may preferably be selected from acetone acetate or picric acid.

[0263] In a preferred embodiment, the metal complex that can be used as a triplet luminescent material has the following form:

[0264]

[0265] Metal atoms M1 are selected from transition metals, lanthanides, or actinides, with preference given to Ir, Pt, Pd, Au, Rh, Ru, Os, Re, Cu, Ag, Ni, Co, W, or Eu, and especially Ir, Au, Pt, W, or Os.

[0266] Ar5 and Ar6, which may appear the same or different each time, are cyclic groups. Ar5 contains at least one donor atom, i.e., an atom with a lone pair of electrons, such as nitrogen, which is coordinated to the metal through its cyclic group. Ar6 contains at least one carbon atom, which is also coordinated to the metal through its cyclic group. Ar5 and Ar6 are covalently linked together and may each carry one or more substituents, and they may also be linked together through substituents. L', which may appear the same or different each time, is a bidentate auxiliary ligand, preferably a monoanionic bidentate ligand. q1 can be 0, 1, 2, or 3, preferably 2 or 3. q2 can be 0, 1, 2, or 3, preferably 1 or 0. Examples of organic ligands may be selected from phenylpyridine derivatives or 7,8-benzoquinoline derivatives. All these organic ligands may be substituted, for example, with alkyl chains or fluorinated or silicon-containing compounds. The auxiliary ligand may preferably be selected from acetone acetate or picric acid.

[0267] In a particularly preferred embodiment, the phosphorescent emitter is a transition metal complex (preferably a metal complex of Ir or Pt) and contains at least one ligand or a subset of ligands selected from the following:

[0268]

[0269]

[0270] Where T is selected from B, Al, Ga, or In; K 1 The direct key is selected from NR. e PR e , O, S or Se; Y 1 -Y 15 Selected from CR 0 Or N; Y 101 Selected from BR e NR e PR e ,O,S,Se,C=O,C=S,C=Se,C=NR e C = CR e R f S = O, SO2, CR e R f P(O)R e SiR e R f or GeR e R f ;R e and R f It can be fused or linked into a ring; R a R b R c and R dThese are represented as substituents or unsubstituted groups, ranging from a single substituent to the maximum possible number;

[0271] R a1 R b1 R c1 R d1 R a R b R c R d R e and R f The groups are selected from H, D, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, boronyl, arylalkyl, alkoxy, aryl, alkenyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfonyl, sulfoxide, phosphoryl, selenyl, or combinations thereof; and R a1 R b1 R c1 R d1 R a R b R c R d Any two adjacent substituents can be fused or linked to form a ring or to form a polydentate ligand; R 0 The definition of R is the same as above. 1 .

[0272] Examples of phosphorescent materials and their applications can be found in the following patent documents and literature: WO200070655, WO200141512, WO200202714, WO200215645, EP1191613, EP1191612, EP1191614, WO2005033244, WO2005019373, US20050258742, WO2009146 770, WO2010015307, WO2010031485, WO2010054731, WO2010054728, WO2010086089, WO20100998 52, WO2010102709, US20070087219A1, US20090061681A1, US20010053462A1, Baldo, Thompsonnet al.Nature 403,(2000),750-753, Adachi et al.Appl.Phys.Lett.78(2001),1622-1624, J.Kido et al.Appl.Phys.Lett.65(1994),2124, Kido et al. al.Chem.Lett.657,1990,US20070252517A1,Johnson et al.,JACS105,1983,1795,Wrighton,JACS 96,1974,998,Maet al.,Synth.Metals 94, 1998, 245, US6824895, US7029766, US6835469, US6830828, US20010053462A1, WO2007095118A1, US2012004407A1, WO2012007088A1, WO2012007087A1, WO2012007086A1, US2008027220A1, WO2011157339A1, CN102282150A, WO2009118087A1. The entire contents of the patent documents and literature listed above are hereby incorporated herein by reference.

[0273] The following are some examples of suitable metal complexes for phosphorescent photoluminescent devices, but are not limited to:

[0274]

[0275]

[0276]

[0277] In a preferred embodiment, the mixture further comprises a TADF luminescent material. The TADF luminescent material has a weight percentage of ≤15 wt%, preferably ≤10 wt%, and more preferably ≤8 wt%.

[0278] The following is a more detailed description of TADF luminescent materials (but not limited to this).

[0279] Traditional organic fluorescent materials can only utilize 25% of singlet excitons formed by electrical excitation to emit light, resulting in low internal quantum efficiency (maximum 25%). While phosphorescent materials, due to the strong spin-orbit coupling at the heavy atom centers enhancing intersystem crossing, can effectively utilize singlet and triplet excitons formed by electrical excitation to emit light, achieving an internal quantum efficiency of 100%, their high cost, poor material stability, and severe efficiency roll-off limit their application in OLEDs. Thermally activated delayed fluorescence (TERF) materials are the third generation of organic light-emitting materials developed after organic fluorescent and organic phosphorescent materials. These materials generally possess a small singlet-triplet energy level difference (ΔEst), allowing triplet excitons to transform into singlet excitons through anti-intersystem crossing. This fully utilizes singlet and triplet excitons formed under electrical excitation, achieving an internal quantum efficiency of 100%. Furthermore, the material structure is controllable, its properties are stable, and it is inexpensive, requiring no precious metals, making it a promising candidate for OLED applications.

[0280] TADF materials need to have a small singlet-triplet energy level difference, preferably ΔE. ST <0.3eV, the second best is ΔE ST <0.25eV, or better yet, ΔE ST <0.20eV, preferably ΔE ST <0.1 eV. In a preferred embodiment, the TADF material has a relatively small ΔE. STIn another preferred embodiment, TADF exhibits good fluorescence quantum efficiency. Some TADF-emitting materials can be found in the following patent documents: CN103483332(A), TW201309696(A), TW201309778(A), TW201343874(A), TW201350558(A), US20120217869(A1), WO2013133359(A1), WO2013154064(A1), Adachi, et al. Adv. Mater.,21,2009,4802,Adachi,et.al.Appl.Phys.Lett.,98,2011,083302,Adachi,et.al.Appl.Phys.Lett.,101,2012,093306,Adachi,et.al.Chem.Commun.,48,2012,11392,Adachi,et.al.Nature Photonics, 6, 2012, 253, Adachi, et.al. Nature, 492, 2012, 234, Adachi, et.al. J. Am. Chem. Soc, 134, 2012, 14706, Adachi, et. al. Angew. Chem. Int.Ed,51,2012,11311,Adachi,et.al.Chem.Commun.,48,2012,9580,Adachi,et.al.Chem.Commun.,48,2013,10385,Adachi,et.al.Adv.Mate r.,25,2013,3319, Adachi,et.al.Adv.Mater.,25,2013,3707, Adachi,et.al.Chem.Mater.,25,2013,3038, Adachi,et.al.Chem.Mater.,25,2013,3766, Adachi,et.al.J.Mater.Chem.C.,1,2013,4599, Adachi,et.al.J.Phys.Chem.A.,117,2013,5607. The entire contents of the patents or articles listed above are hereby incorporated herein by reference.

[0281] Below are some examples of suitable TADF luminescent materials:

[0282]

[0283]

[0284] In some embodiments, the mixture according to the invention has a solubility in toluene of ≥10 mg / mL, preferably ≥15 mg / mL, and most preferably ≥20 mg / mL at 25°C.

[0285] The present invention further relates to a composition or ink comprising a mixture as described above and at least one organic solvent.

[0286] When used in printing processes, ink viscosity and surface tension are important parameters. Appropriate ink surface tension parameters are suitable for specific substrates and printing methods.

[0287] In a preferred embodiment, the ink according to the invention has a surface tension of about 19 dyne / cm to 50 dyne / cm at the operating temperature or at 25°C; more preferably, it is in the range of 22 dyne / cm to 35 dyne / cm; and most preferably, it is in the range of 25 dyne / cm to 33 dyne / cm.

[0288] In another preferred embodiment, the ink according to the invention has a viscosity of about 1 cps to 100 cps at the operating temperature or 25°C; preferably 1 cps to 50 cps; more preferably 1.5 cps to 20 cps; and most preferably 4 cps to 20 cps. The composition thus formulated will facilitate inkjet printing.

[0289] Viscosity can be adjusted by various methods, such as by selecting a suitable solvent and adjusting the concentration of the functional material in the ink. The ink containing the mixture according to the invention allows for convenient adjustment of the printing ink within an appropriate range according to the printing method used. Generally, the composition according to the invention contains a functional material in a weight ratio ranging from 0.3 wt% to 30 wt%, preferably from 0.5 wt% to 20 wt%, more preferably from 0.5 wt% to 15 wt%, even more preferably from 0.5 wt% to 10 wt%, and most preferably from 1 wt% to 5 wt%.

[0290] In some embodiments, the ink according to the invention, the at least one organic solvent is selected from aromatic or heteroaromatic solvents, particularly aliphatic chain / ring substituted aromatic solvents, or aromatic ketone solvents, or aromatic ether solvents.

[0291] Examples of solvents suitable for this invention include, but are not limited to: aromatic or heteroaromatic solvents: p-diisopropylbenzene, pentobenzene, tetrahydronaphthalene, cyclohexylbenzene, chloronaphthalene, 1,4-dimethylnaphthalene, 3-isopropylbiphenyl, p-methylisopropylbenzene, dipentylbenzene, tripentylbenzene, pentyltoluene, o-xylene, m-xylene, p-xylene, o-diethylbenzene, m-diethylbenzene, p-diethylbenzene, 1,2,3,4-tetramethylbenzene, 1,2,3,5-tetramethylbenzene, 1,2,4,5-tetramethylbenzene, butylbenzene, dodecylbenzene, dihexylbenzene, dibutylbenzene, p-diisopropylbenzene, 1-methoxynaphthalene, cyclohexylbenzene, dimethylnaphthalene, 3-isopropylbiphenyl, p-methylisopropylbenzene, 1-methylnaphthalene, 1,2,4-trichlorobenzene, 1 3-Dipropoxybenzene, 4,4-difluorodiphenylmethane, 1,2-dimethoxy-4-(1-propenyl)benzene, diphenylmethane, 2-phenylpyridine, 3-phenylpyridine, N-methyldiphenylamine, 4-isopropylbiphenyl, α,α-dichlorodiphenylmethane, 4-(3-phenylpropyl)pyridine, benzyl benzoate, 1,1-bis(3,4-dimethylphenyl)ethane, 2-isopropylnaphthalene, dibenzyl ether, etc.; ketone-based solvents: 1-tetrahydronaphthone, 2-tetrahydronaphthone, 2-(phenylepoxy)tetrahydronaphthone, 6-(methoxy)tetrahydronaphthone, acetophenone, phenylacetone, benzophenone, and their derivatives, such as 4-methylacetophenone, 3-methylacetophenone, 2-methylacetophenone, 4- Methyl acetone, 3-methyl acetone, 2-methyl acetone, isophorone, 2,6,8-trimethyl-4-nonanone, frankinc, 2-nonanone, 3-nonanone, 5-nonanone, 2-decanone, 2,5-hexanedione, phorone, di-n-pentyl ketone; Aromatic ether solvents: 3-phenoxytoluene, butoxybenzene, benzyl butylbenzene, p-anisaldehyde dimethyl acetal, tetrahydro-2-phenoxy-2H-pyran, 1,2-dimethoxy-4-(1-propenyl)benzene, 1,4-benzodioxane, 1,3-dipropylbenzene, 2,5-dimethoxytoluene, 4-ethylphenethyl ether, 1,2,4-trimethoxybenzene, 4-(1-propenyl)-1,2-dimethoxybenzene, 1,3-dimethyl... Oxyphenylene, glycidylphenyl ether, dibenzyl ether, 4-tert-butylanisole, trans-p-propenylanisole, 1,2-dimethoxyphenylene, 1-methoxynaphthalene, diphenyl ether, 2-phenoxymethyl ether, 2-phenoxytetrahydrofuran, ethyl-2-naphthyl ether, pentanyl ether, hexyl ether, dioctyl ether, ethylene glycol dibutyl ether, diethylene glycol diethyl ether, diethylene glycol butyl methyl ether, diethylene glycol dibutyl ether, triethylene glycol dimethyl ether, triethylene glycol ethyl methyl ether, triethylene glycol butyl methyl ether, tripropylene glycol dimethyl ether, tetraethylene glycol dimethyl ether; Ester solvents: alkyl octanoate, alkyl sebacate, alkyl stearate, alkyl benzoate, alkyl phenylacetate, alkyl cinnamate, alkyl oxalate, alkyl maleate, alkyl lactone, alkyl oleate, etc.

[0292] Furthermore, in the ink according to the present invention, the at least one organic solvent may be selected from: aliphatic ketones, such as 2-nonanone, 3-nonanone, 5-nonanone, 2-decanone, 2,5-hexanedione, 2,6,8-trimethyl-4-nonanone, phorone, di-n-pentyl ketone, etc.; or aliphatic ethers, such as pentyl ether, hexyl ether, dioctyl ether, ethylene glycol dibutyl ether, diethylene glycol diethyl ether, diethylene glycol butyl methyl ether, diethylene glycol dibutyl ether, triethylene glycol dimethyl ether, triethylene glycol ethyl methyl ether, triethylene glycol butyl methyl ether, tripropylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, etc.

[0293] In other embodiments, the printing ink further comprises another organic solvent. Examples of the other organic solvent include (but are not limited to): methanol, ethanol, 2-methoxyethanol, dichloromethane, trichloromethane, chlorobenzene, o-dichlorobenzene, tetrahydrofuran, anisole, morpholine, toluene, o-xylene, m-xylene, p-xylene, 1,4-dioxane, acetone, methyl ethyl ketone, 1,2-dichloroethane, 3-phenoxytoluene, 1,1,1-trichloroethane, 1,1,2,2-tetrachloroethane, ethyl acetate, butyl acetate, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, tetrahydronaphthalene, naphthane, indene, and / or mixtures thereof.

[0294] In a preferred embodiment, the composition according to the invention is a solution.

[0295] In another preferred embodiment, the composition according to the invention is a suspension.

[0296] The compositions in the embodiments of the present invention may include 0.01 wt% to 20 wt% of the mixture according to the present invention, preferably 0.1 wt% to 15 wt%, more preferably 0.2 wt% to 10 wt%, and most preferably 0.25 wt% to 5 wt% of the mixture.

[0297] The present invention also relates to the use of the composition as a coating or printing ink in the preparation of organic electronic devices, particularly preferably by a preparation method of printing or coating.

[0298] Suitable printing or coating technologies include (but are not limited to) gravure printing, inkjet printing, nozzle printing, letterpress printing, screen printing, dip coating, spin coating, doctor blade coating, roller printing, torsional roller printing, offset printing, flexographic printing, rotary printing, spraying, brush coating or pad printing, slot extrusion coating, etc. Gravure printing, nozzle printing, and inkjet printing are preferred. The solution or suspension may additionally include one or more components such as surfactants, lubricants, wetting agents, dispersants, hydrophobic agents, binders, etc., to adjust viscosity, film-forming properties, and improve adhesion. For detailed information on printing technologies and their requirements for related solutions, such as solvent and concentration, viscosity, etc., please refer to *Handbook of Print Media: Technologies and Production Methods*, edited by Helmut Kipphan, ISBN 3-540-67326-1.

[0299] Based on the above mixture, the present invention also provides an application of the mixture as described above, namely, applying the mixture to an organic electronic device, which may be selected from, but is not limited to, organic light-emitting diodes (OLEDs), organic photovoltaic cells (OPVs), organic light-emitting cells (OLEECs), organic field-effect transistors (OFETs), organic light-emitting field-effect transistors, organic lasers, organic spintronic devices or organic sensors, and organic plasmon emitting diodes, particularly OLEDs. In embodiments of the present invention, it is preferable to use the mixture in the light-emitting layer of an OLED device.

[0300] The present invention further provides an optoelectronic device comprising at least one mixture as described above.

[0301] In some preferred embodiments, the optoelectronic device is an organic light-emitting diode (OLED), an organic photovoltaic cell (OPV), an organic light-emitting cell (OLEEC), an organic field-effect transistor (OFET), an organic light-emitting field-effect transistor, an organic sensor, or an organic plasmon emitting diode.

[0302] In some more preferred embodiments, the optoelectronic device is an organic electroluminescent device, comprising a substrate, an anode, at least one light-emitting layer, a cathode, and optionally a hole transport layer or an electron transport layer. In a preferred embodiment, the light-emitting layer comprises a mixture according to the invention, or the light-emitting layer is prepared using the composition described above. More preferably, the light-emitting layer comprises a mixture according to the invention and at least one luminescent material, which is preferably a phosphorescent material or a TADF material.

[0303] The following describes the device structure of optoelectronic devices, but is not limited to this.

[0304] The substrate can be opaque or transparent. A transparent substrate can be used to fabricate a transparent light-emitting device. See, for example, Bulovic et al., Nature 1996, 380, p29, and Gu et al., Appl. Phys. Lett. 1996, 68, p2606. The substrate can be rigid or flexible. The substrate can be plastic, metal, semiconductor wafer, or glass. Preferably, the substrate has a smooth surface. A substrate without surface defects is particularly desirable. In a preferred embodiment, the substrate is flexible and can be a polymer film or plastic with a glass transition temperature (Tg) of 150°C or higher, preferably 200°C, more preferably 250°C, and most preferably 300°C. Examples of suitable flexible substrates include polyethylene terephthalate (PET) and polyethylene glycol (2,6-naphthalene) (PEN).

[0305] The anode may comprise a conductive metal or metal oxide, or a conductive polymer. Holes can be readily injected into the hole injection layer (HIL), hole transport layer (HTL), or light-emitting layer. In one embodiment, the absolute value of the difference between the work function of the anode and the HOMO level or valence band level of the light emitter in the light-emitting layer or the p-type semiconductor material serving as the HIL, HTL, or electron blocking layer (EBL) is less than 0.5 eV, preferably less than 0.3 eV, and most preferably less than 0.2 eV. Examples of anode materials include, but are not limited to, Al, Cu, Au, Ag, Mg, Fe, Co, Ni, Mn, Pd, Pt, ITO, aluminum-doped zinc oxide (AZO), etc. Other suitable anode materials are known and can be readily selected by those skilled in the art. The anode material can be deposited using any suitable technique, such as a suitable physical vapor deposition method, including radio frequency magnetron sputtering, vacuum thermal evaporation, electron beam (e-beam), etc. In some embodiments, the anode is patterned. Patterned ITO conductive substrates are commercially available and can be used to fabricate devices according to the present invention.

[0306] The cathode may comprise a conductive metal or metal oxide. Electrons can be readily injected into the EIL or ETL or directly into the light-emitting layer. In one embodiment, the absolute value of the difference between the work function of the cathode and the LUMO level or conduction band level of the luminescent material in the light-emitting layer or the n-type semiconductor material serving as the electron injection layer (EIL), electron transport layer (ETL), or hole blocking layer (HBL) is less than 0.5 eV, preferably less than 0.3 eV, and most preferably less than 0.2 eV. In principle, all materials suitable for use as cathodes in OLEDs can be used as cathode materials for the devices of this invention. Examples of cathode materials include, but are not limited to: Al, Au, Ag, Ca, Ba, Mg, LiF / Al, MgAg alloy, BaF2 / Al, Cu, Fe, Co, Ni, Mn, Pd, Pt, ITO, etc. The cathode material can be deposited using any suitable technique, such as a suitable physical vapor deposition method, including radio frequency magnetron sputtering, vacuum thermal evaporation, electron beam (e-beam), etc.

[0307] OLEDs may also include other functional layers, such as a hole injection layer (HIL), a hole transport layer (HTL), an electron blocking layer (EBL), an electron transport layer (ETL), and a hole blocking layer (HBL). Materials suitable for use in these functional layers are described in detail above and in WO2010135519A1, US20090134784A1, and WO2011110277A1, the entire contents of which are hereby incorporated herein by reference.

[0308] In a preferred embodiment, the light-emitting layer of the optoelectronic device according to the invention comprises the mixture of the invention.

[0309] The optoelectronic device according to the present invention has an emission wavelength between 300nm and 1000nm, preferably between 350nm and 900nm, and more preferably between 400nm and 800nm.

[0310] Furthermore, the optoelectronic device also includes a cathode capping layer (CPL).

[0311] Materials used in CPL generally require a high refractive index n, such as n ≥ 1.95 @ 460 nm, n ≥ 1.90 @ 520 nm, or n ≥ 1.85 @ 620 nm. Examples of materials used in CPL include:

[0312]

[0313] Further examples of CPL materials can be found in the following patent documents: KR20140128653A, KR20140137231A, KR20140142021A, KR20140142923A, KR20140143618A, KR20140145370A, KR20150004099A, KR20150012835A, US9496520B2, US2015069350A1, CN10382 8485B, CN104380842B, CN105576143A, TW201506128A, CN103996794A, CN103996795A, CN104744450A, CN104752619A, CN101944570A, US2016308162A1, US9095033B2, US2014034942A1, WO2017014357A1; the above patent documents are hereby incorporated into this document for reference.

[0314] Preferably, in the above-mentioned optoelectronic device, the encapsulation layer is a thin-film encapsulation (TFE).

[0315] The present invention also relates to the application of the optoelectronic device according to the invention in various electronic devices, including, but not limited to, display devices, lighting devices, light sources, sensors, etc.

[0316] Example

[0317] The present invention will now be described in conjunction with preferred embodiments, but the present invention is not limited to the following embodiments. It should be understood that the appended claims summarize the scope of the present invention. Under the guidance of the inventive concept, those skilled in the art should realize that any changes made to the various embodiments of the present invention will be covered by the spirit and scope of the claims of the present invention.

[0318] 1. Materials used

[0319] The materials used in specific embodiments of the present invention are as follows:

[0320]

[0321]

[0322] Example 1: Synthesis of E1-1 (first luminescent material)

[0323]

[0324] In a 50 mL three-necked flask, compounds 1-1 (5.9 g, 20.0 mmol), 1-2 (6.91 g, 20.0 mmol), toluene (20 mL), sodium tert-butoxide (3.93 g, 40 mmol), Pd2(DBA)3 (184 mg), and Xantphos (232 mg) were added sequentially. The mixture was purged with nitrogen three times and heated to 110 °C. The reaction was monitored by TLC. After the reaction was complete, the mixture was cooled to room temperature, and the solvent in the reaction system was removed by rotary evaporation. The mixture was extracted with ethyl acetate and saturated sodium chloride solution. The combined organic phases were dried, filtered, concentrated, and then separated by silica gel column chromatography using n-hexane:dichloromethane in a volume ratio of 8:1 to obtain product compound 1a, which, after drying, yielded approximately 6.15 g, representing a yield of approximately 55%.

[0325]

[0326] Compound 1a (5.45 g, 10.0 mmol), compounds 1-3 (2.91 g, 10.0 mmol), potassium carbonate (2.76 g, 20.0 mmol), and DMF (30 mL) were added sequentially to a 50 mL three-necked flask. The mixture was stirred magnetically and heated to reflux for 6 h. The reaction was monitored by TLC, and the reaction was stopped when the starting materials were almost completely consumed. The mixture was extracted with ethyl acetate and saturated sodium chloride solution, and the organic phase was concentrated. The solution was then slurried with 50 mL of methanol to obtain product compound 1b, which, after drying, yielded approximately 5.2 g, representing a yield of approximately 64%.

[0327]

[0328] In a 50 mL three-necked flask, compound 1b (4.08 g, 5.0 mmol), compounds 1-4 (1.69 g, 5.0 mmol), toluene (20 mL), sodium tert-butoxide (0.96 g, 10 mmol), Pd2(DBA)3 (55 mg), and Xantphos (70 mg) were added sequentially. The mixture was purged with nitrogen three times and heated to 110 °C. The reaction was monitored by TLC. After the reaction was complete, the mixture was cooled to room temperature, and the solvent in the reaction system was removed by rotary evaporation. The mixture was extracted with ethyl acetate and saturated sodium chloride solution. The combined organic phases were dried, filtered, concentrated, and then separated by silica gel column chromatography using n-hexane:dichloromethane (10:1, v / v) as the eluent to obtain product compound 1c, approximately 4 g after drying, with a yield of approximately 74.6%.

[0329]

[0330] In a 50 mL three-necked flask, compound 1c (4 g, 3.72 mmol), compounds 1-5 (0.87 g, 3.72 mmol), toluene (20 mL), sodium tert-butoxide (0.72 g, 7.45 mmol), Pd2(DBA)3 (47 mg), and P(t-Bu)3 (38 mg) were added sequentially. The mixture was purged with nitrogen three times and heated to 110 °C. The reaction was monitored by TLC. After the reaction was complete, the mixture was cooled to room temperature, and the solvent in the reaction system was removed by rotary evaporation. The mixture was extracted with ethyl acetate and saturated sodium chloride solution. The combined organic phases were dried, filtered, concentrated, and then separated by silica gel column chromatography using n-hexane:dichloromethane = 15:1 (v / v) as eluent to obtain product compound 1d, which was approximately 3.12 g after drying, with a yield of approximately 68.3%.

[0331]

[0332] Compound 1d (2.45 g, 2.0 mmol) and tert-butylbenzene (20 mL) were added sequentially to a 50 mL three-necked flask. 1.6 M tert-butyllithium (1.87 mL, 3.0 mmol) was added dropwise at -78 °C. After reacting for 1 h, boron tribromide (1.25 g, 5.0 mmol) was added dropwise at 0 °C. The temperature was raised to 120 °C and reacted for 2 h. Diisopropylethylamine (1.16 g, 9.0 mmol) was added dropwise at 80 °C, and the temperature was raised to 120 °C and reacted for 3 h. The reaction was monitored by TLC. After the reaction was complete, the mixture was cooled to room temperature, and the solvent was removed by rotary evaporation. The mixture was extracted with ethyl acetate and saturated sodium chloride solution. The combined organic phases were dried, filtered, concentrated, and eluented with n-hexane:dichloromethane (10:1, v / v) to separate the product E1-1 by silica gel column chromatography. Approximately 0.4 g of the product was obtained after drying, with a yield of approximately 16.7%.

[0333] Example 2: Synthesis of E2-1 (Second luminescent material)

[0334]

[0335] In a 50 mL three-necked flask, compounds 1-1 (2.89 g, 10.0 mmol), 1-6 (2.8 g, 10.0 mmol), toluene (20 mL), sodium tert-butoxide (1.44 g, 15 mmol), Pd2(DBA)3 (92 mg), and Xantphos (116 mg) were added sequentially. The mixture was purged with nitrogen three times and heated to 110 °C. The reaction was monitored by TLC. After the reaction was complete, the mixture was cooled to room temperature, and the solvent in the reaction system was removed by rotary evaporation. The mixture was extracted with ethyl acetate and saturated sodium chloride solution. The combined organic phases were dried, filtered, concentrated, and then separated by silica gel column chromatography using n-hexane:dichloromethane (15:1, v / v) as eluent to obtain product compound 2a, which yielded approximately 6.15 g after drying, representing a yield of approximately 61.5%.

[0336]

[0337] Compound 2a (3.0 g, 6.16 mmol), compound 2-1 (2.04 g, 6.16 mmol), potassium carbonate (1.7 g, 12.3 mmol), and DMF (30 mL) were added sequentially to a 50 mL three-necked flask. The mixture was stirred magnetically and heated to reflux for 6 h. The reaction was monitored by TLC, and the reaction was stopped when the starting materials were almost completely consumed. The mixture was extracted with ethyl acetate and saturated sodium chloride solution, and the organic phase was concentrated. The solution was then slurried with 50 mL of methanol to obtain product compound 2b, which, after drying, yielded approximately 3.2 g, representing a yield of approximately 65.1%.

[0338]

[0339] In a 50 mL three-necked flask, compound 2b (3.2 g, 4.0 mmol), compound 3-1 (1.13 g, 4.0 mmol), toluene (20 mL), sodium tert-butoxide (0.58 g, 6 mmol), Pd2(DBA)3 (55 mg), and Xantphos (70 mg) were added sequentially. The mixture was purged with nitrogen three times and heated to 110 °C. The reaction was monitored by TLC. After the reaction was complete, the mixture was cooled to room temperature, and the solvent in the reaction system was removed by rotary evaporation. The mixture was extracted with ethyl acetate and saturated sodium chloride solution. The combined organic phases were dried, filtered, concentrated, and then separated by silica gel column chromatography using n-hexane:dichloromethane (12:1, v / v) as eluent to obtain product compound 2c, which, after drying, yielded approximately 3.1 g, with a yield of approximately 77.41%.

[0340]

[0341] Compound 2c (3.1 g, 2.8 mmol) and tert-butylbenzene (20 mL) were added sequentially to a 50 mL three-necked flask. 1.6 M tert-butyllithium (2.91 mL, 4.66 mmol) was added dropwise at -78 °C. After reacting for 1 h, boron tribromide (1.95 g, 7.77 mmol) was added dropwise at 0 °C. The temperature was raised to 120 °C and reacted for 2 h. Diisopropylethylamine (1.81 g, 13.98 mmol) was added dropwise at 80 °C, and the temperature was raised to 120 °C and reacted for 3 h. The reaction was monitored by TLC. After the reaction was complete, the mixture was cooled to room temperature, and the solvent was removed by rotary evaporation. The mixture was extracted with ethyl acetate and saturated sodium chloride solution. The combined organic phases were dried, filtered, concentrated, and eluented with n-hexane:dichloromethane (10:1, v / v) to separate the product E2-1 by silica gel column chromatography. Approximately 0.47 g of the product was obtained after drying, with a yield of approximately 15.6%.

[0342] Example 3: Synthesis of E1-2 (first luminescent material)

[0343]

[0344] In a 1000 mL three-necked flask, compound 3-1 (61.9 g, 220 mmol), starting material 4-1 (34.9 g, 100 mmol), sodium tert-butoxide (28.8 g, 300 mmol), Pd2(dba)3 (915 mg, 1.0 mmol), TTBP·HBF4 (580 mg, 2.0 mmol), and 400 mL of toluene were added sequentially. The mixture was purged with nitrogen three times and heated to 110 °C. The reaction was monitored by TLC. After the reaction was complete, the mixture was cooled to room temperature and extracted with ethyl acetate and saturated sodium chloride solution. The combined organic phases were dried, filtered, concentrated, and separated by silica gel column chromatography using n-hexane as eluent to obtain intermediate 4a, which yielded approximately 61.5 g after drying, representing a yield of approximately 82.1%.

[0345]

[0346] Intermediate 4a (30.0 g, 40.0 mmol) and 200 mL of ultra-dry tert-butylbenzene were added to a 500 mL three-necked flask. The mixture was purged with nitrogen three times. 2.5 M n-butyllithium (17.6 mL, 44.0 mmol) was added dropwise at 0 °C. After the addition was complete, the mixture was reacted at room temperature for 1 h. Boron tribromide (5.7 mL, 60 mmol) was added dropwise at 0 °C, and the mixture was reacted at room temperature for 2 h. Diisopropylethylamine (27.8 mL, 160.0 mmol) was added dropwise at 0 °C, and the mixture was heated to 120 °C and reacted for 3 h. After the reaction was complete, the mixture was cooled to room temperature and extracted with ethyl acetate and saturated sodium chloride solution. The combined organic phases were dried, filtered, concentrated, and recrystallized from toluene to give intermediate 4b, which yielded approximately 9.64 g after drying, with a yield of approximately 35.5%.

[0347]

[0348] In a 100 mL three-necked flask, 4b (3.4 g, 5.0 mmol), compound 5-1 (1.6 g, 5.5 mmol), 30 mL toluene, sodium tert-butoxide (0.7 g, 7.5 mmol), Pd2(dba)3 (45 mg, 0.05 mmol), and X-Phos (48 mg, 0.1 mmol) were added sequentially. The mixture was purged with nitrogen three times and heated to 110 °C. The reaction was monitored by TLC. After the reaction was complete, the mixture was cooled to room temperature and extracted with ethyl acetate and saturated sodium chloride solution. The combined organic phases were dried, filtered, concentrated, and recrystallized from toluene to give product E1-2, which weighed approximately 3.38 g after drying, with a yield of approximately 72.6%.

[0349] Example 4: Synthesis of E1-4 (first luminescent material)

[0350]

[0351] Synthesis of intermediate 6a: Compound 1-1 (28.8 g, 100.0 mmol), compound 1-2 (37.1 g, 110.0 mmol), 300 mL toluene, sodium tert-butoxide (14.4 g, 150.0 mmol), Pd2(dba)3 (916 mg, 1.0 mmol), and Xantphos (1.1 g, 2.0 mmol) were added sequentially to a 500 mL three-necked flask. The mixture was purged with nitrogen three times and heated to 110 °C. The reaction was monitored by TLC. After the reaction was complete, the mixture was cooled to room temperature, and the solvent in the reaction system was removed by rotary evaporation. The mixture was extracted with ethyl acetate and saturated sodium chloride solution. The combined organic phases were dried, filtered, concentrated, and then separated by silica gel column chromatography using n-hexane:dichloromethane (15:1, v / v) as the eluent. Intermediate 6a was obtained, yielding approximately 33.5 g after drying, with a yield of 61.5%.

[0352]

[0353] Synthesis of Intermediate 7a: Intermediate 6a (30.0 g, 55.0 mmol), compound 5-1 (17.6 g, 60.5 mmol), cesium carbonate (26.5 g, 82.5 mmol), and 300 mL of DMF were added sequentially to a 500 mL three-necked flask, and the mixture was heated to reflux. The reaction was monitored by TLC, and the reaction was stopped after the starting materials were almost completely consumed. The mixture was then stirred with 300 mL of methanol and 100 mL of water at room temperature for 2 h to obtain intermediate 7a, which yielded approximately 29.2 g after drying, representing a yield of approximately 65.1%.

[0354]

[0355] Synthesis of intermediate 8a: In a 500 mL three-necked flask, intermediate 7a (25.0 g, 30.6 mmol), compounds 1-6 (9.4 g, 33.6 mmol), 200 mL toluene, sodium tert-butoxide (4.4 g, 45.9 mmol), Pd2(dba)3 (280 mg, 0.3 mmol), and TTBPH·BF4 (174.0 mg, 0.6 mmol) were added sequentially. The mixture was purged with nitrogen three times and heated to 110 °C. The reaction was monitored by TLC. After the reaction was complete, the mixture was cooled to room temperature, and the solvent in the reaction system was removed by rotary evaporation. The mixture was extracted with ethyl acetate and saturated sodium chloride solution. The combined organic phases were dried, filtered, concentrated, and then separated by silica gel column chromatography using n-hexane:dichloromethane (12:1, v / v) as eluent to obtain intermediate 8a, which yielded approximately 21.7 g after drying, with a yield of approximately 69.8%.

[0356]

[0357] Synthesis of compound E1-4: Intermediate 8a (20.0 g, 19.7 mmol) and 200 mL of tert-butylbenzene were added to a 500 mL three-necked flask. The mixture was purged with nitrogen three times. 1.6 M tert-butyllithium (25.8 mL, 43.34 mmol) was added dropwise at 0 °C. After the addition was complete, the temperature was raised to 60 °C and the reaction was carried out for 1 h. Boron tribromide (5.6 mL, 59.1 mmol) was added dropwise at 0 °C, and the reaction was carried out at room temperature for 2 h. Diisopropylethylamine (25.8 mL, 147.7 mmol) was added dropwise at 0 °C, and the reaction was carried out at 120 °C for 3 h. After the reaction was completed, the mixture was cooled to room temperature, and the solvent in the reaction system was removed by rotary evaporation. The mixture was extracted with ethyl acetate and saturated sodium chloride solution. The combined organic phases were dried, filtered, concentrated, and recrystallized from toluene to give compound E1-4, approximately 2.9 g after drying, with a yield of approximately 14.9%.

[0358] Example 5: Synthesis of E2-2 (Second Light Source)

[0359]

[0360] Synthesis of intermediate 9a: Compound 9-1 (17.1 g, 30.6 mmol), compound 9-2 (17.3 g, 33.6 mmol), 200 mL toluene, sodium tert-butoxide (4.4 g, 45.9 mmol), Pd2(dba)3 (280 mg, 0.3 mmol), and TTBPH·BF4 (174.0 mg, 0.6 mmol) were added sequentially to a 500 mL three-necked flask. The mixture was purged with nitrogen three times and heated to 110 °C. The reaction was monitored by TLC. After the reaction was complete, the mixture was cooled to room temperature, and the solvent was removed by rotary evaporation. The mixture was extracted with ethyl acetate and saturated sodium chloride solution. The combined organic phases were dried, filtered, concentrated, and eluented with n-hexane:dichloromethane (8:1, v / v) to obtain intermediate 9a by silica gel column chromatography. The yield after drying was approximately 19.6 g, with a yield of approximately 61.9%.

[0361]

[0362] Synthesis of compound E2-2: Intermediate 9a (20.4 g, 19.7 mmol) and 200 mL of tert-butylbenzene were added to a 500 mL three-necked flask. The mixture was purged with nitrogen three times. 1.6 M tert-butyllithium (25.8 mL, 43.34 mmol) was added dropwise at 0 °C. After the addition was complete, the temperature was raised to 60 °C and the reaction proceeded for 1 h. Boron tribromide (5.6 mL, 59.1 mmol) was added dropwise at 0 °C, and the reaction proceeded to room temperature for 2 h. Diisopropylethylamine (25.8 mL, 147.7 mmol) was added dropwise at 0 °C, and the reaction proceeded to 120 °C and the reaction proceeded for 3 h. After the reaction was completed, the mixture was cooled to room temperature, and the solvent was removed by rotary evaporation. The mixture was extracted with ethyl acetate and saturated sodium chloride solution. The combined organic phases were dried, filtered, concentrated, and recrystallized from toluene to give compound E2-2, approximately 3.5 g after drying, with a yield of approximately 17.5%.

[0363] The synthesis of H1-1 and H2-1 can be found in (doi: 10.1038 / s41566-022-00958-4);

[0364] For the synthesis of E1-3, please refer to US2020259096A1;

[0365] For the synthesis of E1-5, please refer to WO2022145773A1;

[0366] For the synthesis of E2-3, please refer to CN117567491A;

[0367] The synthesis of E2-4 can be found in (doi:10.1016 / j.molstruc.2016.07.105);

[0368] For the synthesis of E2-5, see WO2015061198;

[0369] For the synthesis of E2-6, please refer to WO2019240251;

[0370] For the synthesis of E2-7, see US20140309458;

[0371] For the synthesis of E2-8, please refer to WO2006098080;

[0372] For the synthesis of E2-9, see KR1020210117521A;

[0373] For the synthesis of E2-10, see JP5867269;

[0374] For the synthesis of E2-11, see JP5666130;

[0375] For the synthesis of E2-12, see TWI574948;

[0376] For the synthesis of E2-13, please refer to CN106654053B;

[0377] For the synthesis of comparative compound A and comparative compound B, please refer to CN107417486.

[0378] 2. Optical performance of E1-1 and E2-1

[0379] Figure 1 The emission (PL) spectrum of E1-1 in toluene and the absorption (Abs) and emission (PL) spectra of E2-1 in toluene are shown, with significant overlap between the absorption (Abs) spectrum of E2-1 and the emission (PL) spectrum of E1-1.

[0380] 3. Energy level structure of compounds

[0381] Energy levels of organic compounds can be obtained through quantum computing, such as using TD-DFT (time-dependent density functional theory) with Gaussian 09W (Gaussian Inc.). For specific simulation methods, please refer to WO2011141110. First, the molecular geometry is optimized using the semi-empirical method "Ground State / Semi-empirical / Default Spin / AM1" (Charge 0 / Spin Singlet). Then, the energy structure of the organic molecule is calculated using TD-DFT (time-dependent density functional theory) to obtain "TD-SCF / DFT / Default Spin / B3PW91" and the basis set "6-31G(d)" (Charge 0 / Spin Singlet). HOMO and LUMO energy levels are calculated according to the following calibration formula, E... S1 E T1 The resonance factor f(S1) can be used directly.

[0382] HOMO(eV)=((HOMO(G)×27.212)-0.9899) / 1.1206

[0383] LUMO(eV)=((LUMO(G)×27.212)-2.0041) / 1.385

[0384] HOMO(G) and LUMO(G) are direct calculations using Gaussian 09W, expressed in Hartree units. The results are shown in Table 1.

[0385] Table 1

[0386]

[0387] E ex=min[LUMO(H1-1)-HOMO(H2-1), LUMO(H2-1)-HOMO(H1-1)]=2.6eV<min[E T1 (H1-1), E T1 [(H2-1)]+0.1eV, and E ex >E T1 (E1-1) or E T1 (E2-1), thus it can be seen that the mixture of H1-1, H2-1, E1-1 and E2-1 is a mixture according to the present invention.

[0388] 4. Fabrication and characterization of vapor-deposited OLED devices

[0389]

[0390] The structure of the blue OLED device OLED1 according to the present invention is HI (10nm) / HT (60nm) / blocking layer 1 (H1-1, 15nm) / H1-1:H2-1:E1-1:E2-1 (54.8:41.2:3:1, 35nm) / blocking layer 2 (HB, 5nm) / ET:LiQ=50:50 (30nm) / LiQ (2nm) / Al (100nm), where (H1-1+H2-1, 1:1) indicates that H1-1 and H2-1 are co-evaporated in a 1:1 ratio.

[0391] a. Cleaning of ITO (Indium Tin Oxide) conductive glass substrate: Clean with various solvents (such as chloroform, acetone or isopropanol or one or more of these), and then perform ultraviolet ozone treatment.

[0392] b. Evaporation: The ITO substrate is transferred into a vacuum vapor deposition apparatus and deposited under high vacuum (1×10⁻⁶). -6 At a temperature of 10 nm, a HI layer with a thickness of 10 nm was formed using a resistance-heated evaporation source. A HT compound was then deposited on the HI layer to form a 60 nm hole transport layer HT, followed by a 15 nm barrier layer 1. Subsequently, four evaporation sources were used, with the material vaporized at different rates, resulting in an H1-1:H2-1:E1-1:E2-1 ratio of 54.8:41.2:3:1, forming a 35 nm light-emitting layer. Next, a barrier layer 2 (5 nm) was deposited. Then, ET and LiQ were placed in different evaporation units and co-deposited at a ratio of 50% by weight to obtain an electron transport layer (30 nm). A 2 nm layer of LiQ was then deposited as an electron injection layer, and finally, a 100 nm thick Al cathode was deposited on the electron injection layer.

[0393] c. Packaging: The device is encapsulated in a nitrogen glove box using UV-cured resin.

[0394] The emitting layer of the comparative OLED-ref1 is H1-1:H2-1:E2-1 (55.8:41.2:3,35nm), and the rest is the same as OLED1.

[0395] Comparative examples OLED-ref2 to OLED-ref13, OLED-ref15 to OLED-ref19 are the same as OLED-ref1 except that E2-1 is replaced by other E1 or E2 compounds in the emitting layer.

[0396] The emitting layer of the comparative example OLED-ref14 is composed of comparative compound A: comparative compound B: E1-5: E2-8 (54.8:41.2:3:1), and other parameters are the same as OLED1.

[0397] In the embodiments OLED2-OLED17, E1 and E2 in the emitting layer are replaced by other compounds, but otherwise they are the same as OLED1.

[0398] The device performance of the above embodiments and comparative examples was tested, as shown in Table 2; where the external quantum efficiency @J10 is defined as 10 mA / cm 2 The EQE is defined as follows: Device lifetime T95@1000nits is defined as the time it takes for the brightness to decay to 95% of the initial value under constant current conditions when the initial brightness of the device is 1000nits (the results for OLED1 in the table are compared relative values ​​based on the values ​​of the comparative example (OLED-Ref1)).

[0399] Table 2

[0400]

[0401]

[0402] As can be seen from Table 2, by using the mixture according to the present invention, namely H1-1:H2-1:E1-1:E2-1, the lifespan of the OLED can be significantly improved. At the same time, the luminous efficiency is almost the same as or slightly improved compared with the use of the corresponding single guest E1-X (X is 1, 2, 3, 4 or 5).

[0403] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0404] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A mixture comprising a first host material H1, a second host material H2, a first light emitter E1, and a second light emitter E2, characterized in that, 1) The emission peak wavelength of the first luminescent body E1 is shorter than that of the second luminescent body E2, and the absorption spectrum of the second luminescent body E2 and the emission spectrum of the first luminescent body E1 at least partially overlap; 2) The first luminescent body E1 is selected from the structure shown in chemical formula (I-1) or (I-2); 3) E T1 (E1)≤min[LUMO(H1)-HOMO(H2),LUMO(H2)-HOMO(H1)]≤min[E T1 (H1),E T1 [(H2)]+0.1eV, where E T1 (E1) is the triplet energy level of the first luminescent body E1, LUMO(H1), HOMO(H1) and E T1 (H1) represents the lowest unoccupied orbital, the highest occupied orbital, and the triplet energy level of the first host material H1, respectively, LUMO(H2), HOMO(H2), and E. T1 (H2) represents the lowest unoccupied orbital, the highest occupied orbital, and the triplet energy level of the second host material H2, respectively. in: Ar 1 -Ar 3 The same or different ones are selected from aromatic or heteroaromatic groups having 5 to 24 ring atoms; Ar 4 -Ar 5 The same or different are selected from aromatic or heteroaromatic groups with empty ring atoms or having 5 to 24 ring atoms; When Ar 4 -Ar 5 When not empty, X a and X b Each occurrence is independently selected from N, C(R) 6 ) or Si(R 6 ), Y a and Y b Each occurrence is independently selected from B, P=O, and C(R). 6 ) or Si(R 6 ); When Ar 4 Or Ar 5 When X is empty b Selected from N, C(R) 6 ) or Si(R 6 ), Y a Selected from B, P=O, C(R) 6 ) or Si(R 6 ), corresponding X a Or Y b Each occurrence is independently selected from N(R) 6 ), C(R 6 R 7 ), Si(R) 6 R 7 C=O, O, C=N(R) 6 ), C = C(R) 6 R 7 ), P(R 6 ), P(=O)R 6 S, S = O or SO2; X 1 X 2 It is independently selected from empty space or a bridging group; R 1 -R 7 Each time it appears, it may be selected from H, D, or straight-chain alkyl, haloalkyl, alkoxy, or thioalkoxy groups having 1 to 20 carbon atoms; or branched or cyclic alkyl, haloalkyl, alkoxy, thioalkoxy, or silyl groups having 3 to 20 carbon atoms; or substituted ketyl groups having 1 to 20 carbon atoms; or alkoxycarbonyl groups having 2 to 20 carbon atoms; or aryloxycarbonyl groups having 7 to 20 carbon atoms; or cyano groups, carbamoyl groups, haloformyl groups, formyl groups, or isocyano groups. The following groups are included: isocyanate groups, thiocyanate groups, isothiocyanate groups, hydroxyl groups, nitro groups, CF3, Cl, Br, F, I, crosslinkable groups, or substituted or unsubstituted aromatic or heteroaromatic ring systems having 5 to 40 ring atoms, or aryloxy or heteroaryloxy groups having 5 to 40 ring atoms, or arylamine or heteroarylamine groups having 5 to 40 ring atoms, disubstituted units at any position of the above groups, or combinations of these groups, wherein one or more groups may form monocyclic or polycyclic aliphatic or aromatic ring systems with each other and / or with the rings bonded to the groups.

2. The mixture according to claim 1, characterized in that, The first luminescent body E1 is selected from the structure shown by the following chemical formulas (I-1a)-(I-1e) or (I-2a)-(I-2e):

3. The mixture according to claim 1 or 2, characterized in that, Ar 1 Ar 2 Ar 3 Ar 4 Ar 5 Independently selected from one or a combination of the following structural formulas:

4. The mixture according to any one of claims 1 to 3, characterized in that, The second luminescent body E2 is selected from any one of the following chemical formulas: (I-1) or (I-2), (I-1a)-(I-1e), (I-2a)-(I-2e), or (II-1)-(II-18): in: R0-R3, each time appearing, may be the same or different selected from H, D, or straight-chain alkyl, haloalkyl, alkoxy, or thioalkoxy groups having 1 to 20 carbon atoms; or branched or cyclic alkyl, haloalkyl, alkoxy, thioalkoxy, or silyl groups having 3 to 20 carbon atoms; or substituted ketone groups having 1 to 20 carbon atoms; or alkoxycarbonyl groups having 2 to 20 carbon atoms; or aryloxycarbonyl groups having 7 to 20 carbon atoms; or cyano groups, carbamoyl groups, haloformyl groups, formyl groups, or isocyano groups. Cyano group, isocyanate group, thiocyanate group, isothiocyanate group, hydroxy group, nitro group, CF3, Cl, Br, F, I, crosslinkable group, or substituted or unsubstituted aromatic or heteroaromatic ring system having 5 to 40 ring atoms, or aryloxy or heteroaryloxy group having 5 to 40 ring atoms, or arylamine or heteroarylamine group having 5 to 40 ring atoms, disubstituted units at any position of the above groups, or combinations of these groups, wherein one or more groups may form monocyclic or polycyclic aliphatic or aromatic ring system with each other and / or with the ring bonded to the groups; Ar1-Ar4 can be selected from aromatic or heteroaromatic groups with 5 to 60 ring atoms when they appear multiple times, either identically or differently.

5. The mixture according to any one of claims 1 to 4, characterized in that, 1) The difference in molecular weight between the first light emitter E1 and the second light emitter E2 does not exceed 100 Dalton, and / or 2) The difference in sublimation temperature between the first light emitter E1 and the second light emitter E2 does not exceed 30K, and / or 3) In 1×10 -5 ~3×10 -5 At a vacuum level of pa and a vapor deposition temperature of 200℃~280℃, the difference in vapor deposition rate between the first light emitter E1 and the second light emitter E2 does not exceed 5%.

6. The mixture according to any one of claims 1 to 5, characterized in that, The first host material H1 is selected from chemical formula (III-1) or (III-2); and / or the second host material H2 is selected from chemical formula (IV): Among them: Z 101 -Z 103 Selected independently from N or CR 12 And at least one of them is selected from N; L1-L3 are selected from single bonds, or substituted or unsubstituted aromatic or heteroaromatic groups with 6 to 30 ring atoms; Ar 6 -Ar 11 Selected from substituted or unsubstituted aromatic or heteroaromatic groups having 5 to 40 ring atoms, or aryloxy or heteroaryloxy groups having 5 to 40 ring atoms, or combinations of these groups, wherein one or more groups may form a monocyclic or polycyclic aliphatic or aromatic ring system with each other and / or with the rings bonded to the groups. R 8 -R 12 The definition of R as described in claim 1 1 ; n1, n3, and n4 are each independently selected from integers from 0 to 7; n2 is an integer selected from 0 to 8.

7. The mixture according to claim 6, characterized in that, The first host material H1 is selected from any one of chemical formula (III-1a), chemical formula (III-1b), or chemical formula (III-2a):

8. The mixture according to claim 6 or 7, characterized in that, The second host material H2 is selected from chemical formula (IV), and Ar 9 -Ar 11 Each group is independently selected from one of the formulas (V-1) to (V-7): in: W1-W2 are selected from O, S, or Se; m1 is an integer from 0 to 3, m2 is an integer from 0 to 4, and m3 is an integer from 0 to 5; R 101 -R 116 The definition of R as described in claim 1 1 .

9. The mixture according to any one of claims 1 to 8, characterized in that, 1) The difference in molecular weight between the first host material H1 and the second host material H2 does not exceed 100 Daltons, and / or 2) The difference in sublimation temperature between the first host material H1 and the second host material H2 does not exceed 30K, and / or 3) In 1×10 -5 ~3×10 -5 At a vacuum level of pa and a vapor deposition temperature of 200℃~280℃, the difference in vapor deposition rate between the first host material H1 and the second host material H2 does not exceed 5%.

10. A composition comprising a mixture as described in any one of claims 1 to 9, and at least one organic solvent.

11. An optoelectronic device comprising a mixture as described in any one of claims 1 to 9.

12. The optoelectronic device according to claim 11, characterized in that, The optoelectronic device is an organic electroluminescent device and comprises a substrate, an anode, a light-emitting layer and a cathode arranged sequentially, wherein the light-emitting layer comprises at least one mixture as described in any one of claims 1 to 9, or the light-emitting layer is prepared using the composition as described in claim 10.

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