CN112490382B

CN112490382B - Organic light-emitting device and display device

Info

Publication number: CN112490382B
Application number: CN202011380895.8A
Authority: CN
Inventors: 李国孟; 逄辉; 孙佳欣; 李梦真; 周小康; 刘孟宇
Original assignee: Kunshan New Flat Panel Display Technology Center Co Ltd
Current assignee: Kunshan New Flat Panel Display Technology Center Co Ltd
Priority date: 2020-11-30
Filing date: 2020-11-30
Publication date: 2022-09-13
Anticipated expiration: 2040-11-30
Also published as: CN112490382A

Abstract

The present invention relates to an organic electroluminescent device and a display apparatus, the organic electroluminescent device including a first electrode, a second electrode, and an organic layer between the first electrode and the second electrode; the organic layer includes a light emitting layer including a host material, a thermally activated delayed fluorescence sensitizer, and a fluorescent dye selected from compounds represented by formula (1). The invention provides a novel thermal activation sensitized fluorescent device, which can improve the efficiency of the thermal activation sensitized fluorescent device and reduce the driving voltage by selecting a boron-containing compound with a specific structure as a fluorescent dye.

Description

Organic electroluminescent device and display device

Technical Field

The invention relates to the technical field of organic electroluminescence, in particular to an organic electroluminescence device and a display device.

Background

Thermally Activated Sensitized Fluorescence (TASF) refers to that when a Thermally Activated Delayed Fluorescence (TADF) material is used as a sensitizer, the energy of a host material is transferred to the TADF material, and then the triplet state energy returns to the singlet state through a reverse intersystem crossing (RISC) process, so that the energy is transferred to a doped fluorescent dye to emit light, thereby realizing the complete energy transfer from the host to the dye molecule, and enabling the traditional fluorescent doped dye to break through the limit of 25% of internal quantum efficiency.

However, in the TASF light emitting device, there is a problem that dye carrier trapping is serious, and the device has a high driving voltage and a low efficiency.

Therefore, there is a need in the art to develop a new TASF device that reduces the driving voltage and improves the device efficiency.

Disclosure of Invention

In view of the deficiencies of the prior art, it is an object of the present invention to provide an organic electroluminescent device. The organic electroluminescent device has lower driving voltage and higher device efficiency.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention provides an organic electroluminescent device, which comprises a first electrode, a second electrode and an organic layer positioned between the first electrode and the second electrode;

the organic layer comprises a light-emitting layer, the light-emitting layer comprises a host material, a thermally activated delayed fluorescence sensitizer and a fluorescent dye, and the fluorescent dye is selected from a compound shown in a formula (1);

in formula (1):

the ring X, the ring Y and the ring Z are respectively and independently selected from one of substituted or unsubstituted C5-C60 aromatic rings and substituted or unsubstituted C3-C60 heteroaromatic rings;

ar is ¹ And Ar ² Each independently selected from the group consisting of a structure of formula (G), a substituted or unsubstituted C6-C60 aryl group, a substituted or unsubstituted C3-C60 heteroaryl group, and Ar ¹ And Ar ² At least one is a structure represented by the general formula (G);

Ar ¹ form a ring or not form a ring with the adjacent ring X or ring Z, Ar ² Form a ring or not form a ring with the adjacent ring Y or the ring Z;

in the formula (G):

R ^a and R ^b Each independently selected from one of halogen, cyano, substituted or unsubstituted C1-C20 chain alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C1-C20 silyl, substituted or unsubstituted C6-C60 aryl and substituted or unsubstituted C3-C60 heteroaryl, wherein R is one of C, B, C, B, C, B, C and C, B, C, B ^a And R ^b Each independently is linked to the linked aromatic or heteroaromatic ring to form a ring or is not linked to form a ring;

Y ¹ ～Y ³ each independently selected from CR ¹ Or N, R ¹ Independently selected from one of hydrogen, halogen, cyano-group, nitro-group, hydroxyl, amino, substituted or unsubstituted C1-C20 chain alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C1-C20 silyl, substituted or unsubstituted C6-C60 arylamino, substituted or unsubstituted C3-C60 heteroaryl amino, substituted or unsubstituted C6-C60 aryl and substituted or unsubstituted C3-C60 heteroaryl, wherein R is a halogen atom, a cyano-group, a nitro-group, hydroxyl, amino, substituted or unsubstituted C1-C20 chain alkyl, substituted or unsubstituted C1-C20 silyl, substituted or unsubstituted C6 arylamino, substituted or unsubstituted C3-C60 heteroaryl, substituted or unsubstituted C35aryl, and R is a halogen atom ¹ Independently with the attached aromatic or heteroaromatic ring to form a ring or not;

L ¹ one selected from substituted or unsubstituted C6-C60 arylene, substituted or unsubstituted C3-C60 heteroarylene;

n is an integer of 1-5;

when the above groups have substituents, the substituents are selected from one or a combination of at least two of halogen, cyano, carbonyl, nitro, amino, C1-C20 alkyl, C3-C20 cycloalkyl, C1-C20 alkoxy, C1-C20 silyl, C6-C60 arylamino, C3-C60 heteroarylamino, C6-C60 monocyclic aryl or fused ring aryl, and C3-C60 monocyclic heteroaryl or fused ring heteroaryl.

Preferably, in formula (1), at least one of the ring X, ring Y and ring Z is a group represented by formula (a):

ring Z is linked to the other moiety of formula (1) by a shared bond c and a shared bond d, and ring X and ring Y are each independently linked to the other moiety of formula (1) by a shared bond c or a bond d;

in the formula (a), Z ¹ 、Z ² 、Z ³ And Z ⁴ Independently selected from CR ² Or N, said R ² Independently selected from hydrogen, halogen, cyano-group, carbonyl, nitro-group, hydroxyl, amino, C1-C20 chain alkyl, C3-C20 cycloalkyl, C1-C20 alkoxy, C1-C20 silyl, C6-C60 arylamino, C6-C60 heteroaryl aminoOne of C6-C60 aryl and C3-C60 heteroaryl, wherein R is ² Independently with the attached aromatic or heteroaromatic ring, or not.

Preferably, the structure of formula (1) is as shown in formula (2):

ar is ¹ 、Ar ² Is as defined in formula (1), and Z is ¹ 、Z ² 、Z ³ And Z ⁴ Is as defined in formula (a);

z is ^1’ ～Z ^4’ Are each independently selected from CR ³ Or N, said R ³ Independently selected from one of hydrogen, halogen, cyano-group, carbonyl, nitro-group, hydroxyl, amino, C1-C20 chain alkyl, C3-C20 cycloalkyl, C1-C20 alkoxy, C1-C20 silyl, C6-C60 arylamino, C6-C60 heteroaryl amino, C6-C60 aryl and C3-C60 heteroaryl, wherein R is ³ Independently with the attached aromatic or heteroaromatic ring to form a ring or not;

z is ^1” ～Z ^3” Are each independently selected from CR ⁴ Or N, said R ⁴ Independently selected from one of hydrogen, halogen, cyano-group, carbonyl, nitro-group, hydroxyl, amino, C1-C20 chain alkyl, C3-C20 cycloalkyl, C1-C20 alkoxy, C1-C20 silyl, C6-C60 arylamino, C6-C60 heteroaryl amino, C6-C60 aryl and C3-C60 heteroaryl, wherein R is ⁴ Independently with the attached aromatic or heteroaromatic ring, or not.

Preferably, said R is ² 、R ³ 、R ⁴ Each independently selected from C1-C20 chain alkyl and C3-C20 cycloalkyl, preferably R ² 、R ³ 、R ⁴ Each independently selected from one of the following groups:

preferably, Ar is ¹ And Ar ² Selected from the same group.

Preferably, in the formula (G), L ¹ Selected from the group consisting of groups represented by the formula (L-1) or the formula (L-2):

in the formula (L-1), the X ¹ ～X ⁵ Are each independently selected from CR ⁵ Or N, said R ⁵ Independently selected from one of hydrogen, halogen, cyano, carbonyl, nitro, hydroxyl, amino, C1-C20 chain alkyl, C3-C20 cycloalkyl, C1-C20 alkoxy, C1-C20 silyl, C6-C60 arylamino, C6-C60 heteroarylamino, C6-C60 aryl and C3-C60 heteroaryl, wherein R is selected from one of C3-C20 heteroaryl ⁵ Independently with the attached aromatic or heteroaromatic ring to form a ring or not;

in the formula (L-2), M is selected from O, S or NR ⁶ In a group of (A), the R ⁶ Independently selected from one of hydrogen, halogen, cyano, carbonyl, nitro, hydroxyl, amino, C1-C20 chain alkyl, C3-C20 cycloalkyl, C1-C20 alkoxy, C1-C20 silyl, C6-C60 arylamino, C6-C60 heteroarylamino, C6-C60 aryl and C3-C60 heteroaryl, wherein R is selected from one of C3-C20 heteroaryl ⁶ Independently with the linked aromatic or heteroaromatic ring to form a ring or not; m is preferably O or S.

Preferably, formula (G) is selected from the structures represented by any one of formulae (G-1) to (G-6) below:

said X ¹ ～X ⁵ And M is as defined in the formula (L-1) and the formula (L-2), respectively; said Y ¹ ～Y ³ 、R ^a And R ^b Are respectively the same as defined in the formula (G).

Preferably, theR ^a And R ^b At least one of the alkyl groups is one of substituted or unsubstituted C1-C20 chain alkyl groups and substituted or unsubstituted C3-C20 cycloalkyl groups.

Preferably, said R is ^a And R ^b At least one of the groups is one of methyl, ethyl, tertiary butyl, isopropyl, cyclohexyl or fluorine.

Preferably, the fluorescent dye is selected from any one or at least two combinations of compounds shown as M-1 to M-122.

Preferably, the host material is selected from any one or a combination of at least two of the compounds TDH-1 to TDH-30.

Preferably, the thermally activated delayed fluorescence sensitizer is selected from any one or at least two combinations of compounds TDE1 to TDE 37.

Preferably, the mass of the fluorescent dye accounts for 0.1-10% of the total mass of the light-emitting layer.

Preferably, the organic layer further comprises any one or at least two of a hole injection layer, a hole transport layer, a hole blocking layer, an electron transport layer, or an electron injection layer.

Another object of the present invention is to provide a display device including the organic electroluminescent element according to the first object.

Compared with the prior art, the invention has the following beneficial effects:

the invention provides a TASF device, which adopts boron-containing compound with a specific structure as fluorescent dye, and introduces a group containing steric hindrance (R) into a boron-containing mother nucleus ^a And R ^b ) On one hand, the substituted aromatic ring substituent is modified on the freely rotatable aniline fragment, steric hindrance screens are arranged at 2 ortho positions of a connecting site, certain help is provided for improving the material light color, the light color of molecules can be finely adjusted, and simultaneously the device efficiency is improvedThe introduction of the benzene pyridine group can also improve the dipole arrangement of molecules, is beneficial to light extraction, and further improves the efficiency of the device. The invention selects the fluorescent dye with the specific structure, and the light-emitting layer of the device adopts the specific matching of the host material, the sensitizer and the fluorescent dye, thereby effectively improving the efficiency of the device and reducing the driving voltage.

Drawings

Fig. 1 is a schematic view of the structures of organic electroluminescent devices provided in examples and comparative examples of the present invention.

Detailed Description

For the purpose of facilitating an understanding of the present invention, the present invention will now be described by way of examples. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

The inventor finds that a main reason is that in a light emitting layer of the device, because the energy gap of a main material and a sensitizer material is larger than that of a fluorescent dye, and in addition, the migration and transmission capacity of the dye is poor, the fluorescent dye has certain problems of carrier capture and quenching, further the driving voltage is increased, and the efficiency is reduced.

To this end, the present invention provides an organic electroluminescent device comprising a first electrode, a second electrode, and an organic layer between the first and second electrodes;

in formula (1):

Ar ¹ form a ring or not form a ring with the adjacent ring X or ring Z, Ar ² Form a ring or not form a ring with the adjacent ring Y or ring Z;

in the formula (G):

R ^a and R ^b Each independently selected from one of halogen, cyano, substituted or unsubstituted C1-C20 chain alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C1-C20 silyl, substituted or unsubstituted C6-C60 aryl and substituted or unsubstituted C3-C60 heteroaryl, wherein R is one of C, B, C, B, C, B ^a And R ^b Each independently is linked to the linked aromatic or heteroaromatic ring to form a ring or is not linked to form a ring;

Y ¹ ～Y ³ each independently selected from CR ¹ Or N, R ¹ Independently selected from one of hydrogen, halogen, cyano, nitro, hydroxyl, amino, substituted or unsubstituted C1-C20 chain alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C1-C20 silyl, substituted or unsubstituted C6-C60 arylamino, substituted or unsubstituted C3-C60 heteroarylamino, substituted or unsubstituted C6-C60 aryl and substituted or unsubstituted C3-C60 heteroaryl, wherein R is selected from the group consisting of R, halogen, cyano, nitro, hydroxyl, amino, substituted or unsubstituted C1-C20 chain alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C1-C20 silyl, substituted or unsubstituted C6-C60 arylamino, substituted or unsubstituted C3-C60 heteroaryl, substituted or unsubstituted C6-C60 aryl, and substituted or unsubstituted C3-C60 heteroaryl ¹ Independently with the attached aromatic or heteroaromatic ring to form a ring or not;

n is an integer of 1 to 5;

In the present invention, the "substituted or unsubstituted" group may be substituted with one substituent or a plurality of substituents, and when a plurality of substituents are present, different substituents may be selected from the group.

In the present specification, the expression of Ca to Cb means that the group has carbon atoms of a to b, and the carbon atoms do not generally include the carbon atoms of the substituents unless otherwise specified.

In the present specification, the expression "-" of the underlined loop structure means that the linking site is located at any position on the loop structure where a bond can be formed, and denotes the position of the bonding site of the group.

In the present specification, "independently" means that the subject may be the same or different when a plurality of subjects are provided.

The hetero atom in the present invention generally refers to an atom or group of atoms selected from N, O, S, P, Si and Se, preferably N, O, S.

In the present invention, unless otherwise specified, the expression of chemical elements generally includes the concept of isotopes having the same chemical properties, for example, the expression "hydrogen (H)" also includes the concept of 1H (protium or H), 2H (deuterium or D) having the same chemical properties; carbon (C) includes 12C, 13C, etc., and will not be described in detail.

In the present specification, examples of the halogen include: fluorine, chlorine, bromine, iodine, and the like.

In the present invention, the monocyclic aryl group means that one or at least two phenyl groups are contained in a molecule, and when at least two phenyl groups are contained in a molecule, the phenyl groups are independent of each other and are connected by a single bond, such as phenyl, biphenylyl, terphenylyl, etc., for example; the fused ring aryl group means that at least two benzene rings are contained in the molecule, but the benzene rings are not independent of each other, but common ring sides are fused with each other, and exemplified by naphthyl, anthryl and the like; monocyclic heteroaryl refers to a compound having at least one heteroaryl group in the molecule, and when a heteroaryl group and other groups (e.g., aryl, heteroaryl, alkyl, etc.) are present in the molecule, the heteroaryl and other groups are independently linked by a single bond, illustratively pyridine, furan, thiophene, etc.; fused ring heteroaryl refers to a fused ring of at least one phenyl group and at least one heteroaryl group, or, fused ring of at least two heteroaryl rings, illustratively quinoline, isoquinoline, benzofuran, dibenzofuran, benzothiophene, dibenzothiophene, and the like.

In the present invention, both aryl and heteroaryl groups include monocyclic and fused rings unless otherwise specified.

In the present invention, unless otherwise specified, a substituent is not condensed with a group in which it is present.

In the present invention, the substituted or unsubstituted C6-C30 aryl group or C10-C30 condensed ring aryl group is preferably C6-C30 aryl group, more preferably C6-C20 aryl group, and preferably the aryl group is a phenyl group, biphenyl group, terphenyl group, naphthyl group, anthryl group, phenanthryl group, indenyl group, fluorenyl group and derivatives thereof, anthryl group, triphenylene group, pyrenyl group, perylenyl group, perylene group, or the like,

A group of the group consisting of a phenyl group and a tetracenyl group. The biphenyl group is selected from the group consisting of 2-biphenyl, 3-biphenyl, and 4-biphenyl; the terphenyl group includes p-terphenyl-4-yl, p-terphenyl-3-yl, p-terphenyl-2-yl, m-terphenyl-4-yl, m-terphenyl-3-yl and m-terphenyl-2-yl; the naphthyl group includes a 1-naphthyl group or a 2-naphthyl group; the anthracene group is selected from the group consisting of 1-anthracene group, 2-anthracene group, and 9-anthracene group; the fluorenyl group is selected from the group consisting of 1-fluorenyl, 2-fluorenyl, 3-fluorenyl, 4-fluorenyl and 9-fluorenyl; the fluorenyl derivative is selected from the group consisting of 9,9 '-dimethylfluorene, 9' -spirobifluorene and benzofluorene; the pyrenyl group is selected from a group consisting of a 1-pyrenyl group, a 2-pyrenyl group and a 4-pyrenyl group; said tetracene is selected from the group consisting of 1-tetracene, 2-tetracene and 9-tetraceneGroup consisting of radicals.

In the present invention, the substituted or unsubstituted C3-C30 heteroaryl or C3-C30 fused heteroaryl is preferably C3-C30 heteroaryl, more preferably C4-C20 heteroaryl, and preferably the heteroaryl is furyl, thienyl, pyrrolyl, benzofuryl, benzothienyl, isobenzofuryl, indolyl, dibenzofuryl, dibenzothienyl, carbazolyl and derivatives thereof, wherein the carbazolyl derivative is preferably 9-phenyl carbazole, 9-naphthyl carbazole benzocarbazole, dibenzocarbazole, or indolocarbazole.

Specific examples of the arylene group in the present invention include divalent groups obtained by removing one hydrogen atom from the above-mentioned examples of the aryl group. Specific examples of the heteroarylene group in the present invention include divalent groups obtained by removing one hydrogen atom from the above-mentioned examples of the heteroaryl group.

Examples of the aryloxy group in the present invention include monovalent groups composed of the above aryl group, heteroaryl group and oxygen.

Examples of the C6-C30 arylamino group mentioned in the present invention include: phenylamino, methylphenylamino, naphthylamino, anthrylamino, phenanthrylamino, biphenylamino and the like.

Examples of the heteroarylamino group having C3 to C30 in the present invention include: pyridylamino, pyrimidylamino, dibenzofuranylamino and the like.

In the present invention, the chain alkyl group having C1 to C20 is preferably a chain alkyl group having C1 to C10, more preferably a chain alkyl group having C1 to C6, and examples thereof include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-hexyl, n-octyl, n-pentyl, n-heptyl, n-nonyl, n-decyl and the like.

In the present invention, the C3-C20 cycloalkyl group is preferably a cyclopropyl group, a cyclobutyl group, a cyclopentyl group or a cyclohexyl group.

In the above substituents, the number of carbon atoms of the chain alkyl group having from C1 to C10 may be C2, C3, C4, C5, C6, C7, C8, C9, C10, or the like; the carbon number of the C3-C10 cycloalkyl group can be C4, C5, C6, C7, C8, C9, C10 and the like; the C1-C10 alkoxy group may have C2, C3, C4, C5, C6, C7, C8, C9, C10, etc.; the C1-C10 thioalkoxy group may have C2, C3, C4, C5, C6, C7, C8, C9, C10, etc.; the C6-C30 monocyclic aryl group may have C10, C12, C14, C16, C18, C20, C26, C28 and the like; the number of carbons of the C10-C30 condensed ring aryl group may be C10, C12, C14, C16, C18, C20, C26, C28, etc.; the C3-C30 monocyclic heteroaryl group may have C3, C4, C6, C8, C10, C12, C14, C16, C18, C20, C26, C28, etc.; the carbon number of the C6-C30 fused heteroaryl may be C10, C12, C14, C16, C18, C20, C26, C28 and the like.

In the present invention, the C3-C12 cycloalkyl group includes monocyclic alkyl and polycyclic alkyl groups, preferably C1-C10 alkyl groups and C3-C10 cycloalkyl groups.

The invention provides a TASF device, which adopts boron-containing compound with a specific structure as fluorescent dye, and introduces a group containing steric hindrance (R) into a boron-containing mother nucleus ^a And R ^b ) On one hand, the substituted aromatic ring substituent is modified on the freely rotatable aniline fragment, steric hindrance screens are arranged at 2 ortho positions of a connecting site, so that the improvement of the material light color is facilitated to a certain extent, the light color of molecules can be finely adjusted, and the improvement of the device efficiency is facilitated.

The invention selects the fluorescent dye with the specific structure, and adopts the specific matching of the main material, the sensitizer and the fluorescent dye in the light-emitting layer of the device, thereby effectively improving the efficiency of the device and reducing the driving voltage.

In an alternative embodiment, ring X, ring Y and ring Z are each independently selected from one of a substituted or unsubstituted C5-C14 aromatic ring, a substituted or unsubstituted C3-C14 heteroaromatic ring.

In an alternative embodiment, ring X, ring Y and ring Z are each independently selected from one of a substituted or unsubstituted C5-C8 aromatic ring, a substituted or unsubstituted C5-C8 heteroaromatic ring.

In an alternative embodiment, ring X, ring Y and ring Z are each independently selected from one of a substituted or unsubstituted benzene ring, a substituted or unsubstituted furan ring, a substituted or unsubstituted thiophene ring, a substituted or unsubstituted naphthalene ring, a substituted or unsubstituted phenanthrene ring or a substituted or unsubstituted carbazole ring.

In an alternative embodiment, in formula (1), at least one of ring X, ring Y and ring Z is a group represented by formula (a):

in the formula (a), Z ¹ 、Z ² 、Z ³ And Z ⁴ Independently selected from CR ² Or N, said R ² Independently selected from one of hydrogen, halogen, cyano, carbonyl, nitro, hydroxyl, amino, C1-C20 chain alkyl, C3-C20 cycloalkyl, C1-C20 alkoxy, C1-C20 silyl, C6-C60 arylamino, C6-C60 heteroarylamino, C6-C60 aryl and C3-C60 heteroaryl, wherein R is selected from one of C3-C20 heteroaryl ² Independently with the attached aromatic or heteroaromatic ring, or not.

In an alternative embodiment, the structure of formula (1) is as shown in formula (2):

ar is ¹ 、Ar ² Is as defined in formula (1), and Z ¹ 、Z ² 、Z ³ And Z ⁴ Is as defined in formula (a);

z is ^1’ ～Z ^4’ Are each independently selected from CR ³ Or N, said R ³ Independently selected from one of hydrogen, halogen, cyano, carbonyl, nitro, hydroxyl, amino, C1-C20 chain alkyl, C3-C20 cycloalkyl, C1-C20 alkoxy, C1-C20 silyl, C6-C60 arylamino, C6-C60 heteroarylamino, C6-C60 aryl and C3-C60 heteroaryl, wherein R is selected from one of C3-C20 heteroaryl ³ Independently with the attached aromatic or heteroaromatic ring to form a ring or not;

z is ^1” ～Z ^3” Are each independently selected from CR ⁴ Or N, said R ⁴ Independently selected from one of hydrogen, halogen, cyano, carbonyl, nitro, hydroxyl, amino, C1-C20 chain alkyl, C3-C20 cycloalkyl, C1-C20 alkoxy, C1-C20 silyl, C6-C60 arylamino, C6-C60 heteroarylamino, C6-C60 aryl and C3-C60 heteroaryl, wherein R is selected from one of C3-C20 heteroaryl ⁴ Independently with the attached aromatic or heteroaromatic ring, or not.

In an alternative embodiment, in formula (2), Z ⁴ Is CH or N, said Z ^4’ Is CH or N.

In one optional embodiment, Z is ⁴ Is CH or N, said Z ^4’ Is CH or N, said Z ¹ Is CH or N, the Z ^1’ Is CH or N.

In an alternative embodiment, Z is ⁴ 、Z ^4’ 、Z ¹ 、Z ^1’ Are both CH.

In an alternative embodiment, in formula (2), Z ² 、Z ³ Are each independently selected from CR ² Said R is ² Independently selected from one of hydrogen, chain alkyl of C1-C20, cycloalkyl of C3-C20 and aryl of C6-C60, and the Z is ^2’ 、Z ^3’ Are each independently selected from CR ³ Said R is ³ Independently selected from one of hydrogen, chain alkyl of C1-C20, cycloalkyl of C3-C20 and aryl of C6-C60, and the Z is ^2” Selected from the group consisting of CR ⁴ Said R is ⁴ Selected from hydrogen, C1-C20 chain alkyl, C3-C20 cycloalkyl, C6-C60 aryl,One of C3-C60 heteroaryl.

In an alternative embodiment, Z is ² 、Z ^2’ Is selected from CH, said Z ³ Selected from the group consisting of CR ² Said R is ² Independently selected from one of C1-C20 chain alkyl, C3-C20 naphthenic base and C6-C60 aryl, Z ^3’ Selected from the group consisting of CR ³ Said R is ³ Independently selected from one of chain alkyl of C1-C20, naphthenic base of C3-C20 and aryl of C6-C60.

In an alternative embodiment, Z is ³ 、Z ^3’ Selected from CH, said Z ² Selected from the group consisting of CR ² Said R is ² Independently selected from one of C1-C20 chain alkyl, C3-C20 naphthenic base and C6-C60 aryl, Z ^2’ Selected from the group consisting of CR ³ Said R is ³ Independently selected from one of C1-C20 chain alkyl, C3-C20 naphthenic base and C6-C60 aryl.

In an alternative embodiment, said R is ² 、R ³ 、R ⁴ Each independently selected from C1-C20 chain alkyl and C3-C20 cycloalkyl, preferably R ² 、R ³ 、R ⁴ Each independently selected from one of the following groups:

in the preferred technical scheme of the invention, the alkyl or cycloalkyl group with the specific structure on the ring X, the ring Y and the ring Z has a certain steric hindrance effect compared with other groups, and has the advantages of easy synthesis, proper molecular weight, easy evaporation and the like.

In an alternative embodiment, said R is ² 、R ³ 、R ⁴ Each independently selected from one of the following groups:

in an alternative embodiment, in formula (G), L ¹ Selected from the group consisting of groups represented by the formula (L-1) or the formula (L-2):

in the formula (L-2), M is selected from O, S or NR ⁶ In one of (1), the R ⁶ Independently selected from one of hydrogen, halogen, cyano, carbonyl, nitro, hydroxyl, amino, C1-C20 chain alkyl, C3-C20 cycloalkyl, C1-C20 alkoxy, C1-C20 silyl, C6-C60 arylamino, C6-C60 heteroarylamino, C6-C60 aryl and C3-C60 heteroaryl, wherein R is selected from one of C3-C20 heteroaryl ⁶ Independently with the attached aromatic or heteroaromatic ring to form a ring or not; m is preferably O or S.

In an alternative embodiment, formula (G) is selected from the structures represented by any one of formulae (G-1) to (G-6) below:

said X is ¹ ～X ⁵ And M is as defined in the formula (L-1) and the formula (L-2), respectively; said Y is ¹ ～Y ³ 、R ^a And R ^b Are respectively the same as defined in the formula (G).

Further, Ar is preferred in the present invention ¹ And Ar ² Is a formulaThe groups shown in the formulas (G-1) to (G-6) have specific steric hindrance effect, have good transmission capability and are easy to synthesize and prepare, so that the fluorescent dye, the main material and the sensitizer are matched for use, and the performance of the device can be further improved.

In an optional embodiment, n is an integer of 1 to 3.

In an alternative embodiment, said X ¹ ～X ⁵ Are each independently selected from CR ⁵ Or N, and at least 4 of which are selected from CR ⁵ 。

In an alternative embodiment, said X ¹ ～X ⁵ Are each independently selected from CR ⁵ And wherein at least one CR is ⁵ R in (1) ⁵ Is hydrogen.

In an alternative embodiment, said X ¹ ～X ⁵ Are both CH.

In an alternative embodiment, said R is ^a And R ^b At least one of the alkyl groups is one of substituted or unsubstituted C1-C20 chain alkyl groups and substituted or unsubstituted C3-C20 cycloalkyl groups.

Further, R is preferred in the present invention ^a And R ^b The group is alkyl, has an ortho-position clamping effect, enables the connection of the adjacent aromatic ring to be twisted, is beneficial to narrowing of the self-emission spectrum of the dye, enables the fluorescent dye to be matched with a main material and a sensitizer for use, and can further improve the performance of the device, wherein the methyl group has a moderate size and a high reaction yield.

In an alternative embodiment, said R is ^a And R ^b At least one of the above groups is one of methyl, ethyl, tert-butyl, isopropyl, cyclohexyl and fluorine.

In an alternative embodiment, the Ar is ¹ And Ar ² All have a structure represented by the general formula (G).

In an alternative embodiment, the Ar is ¹ And Ar ² Selected from the same group.

Further, Ar is preferred in the present invention ¹ And Ar ² Identical, i.e. the fluorescent dyes have symmetryThe substituent has better molecular orientation, is easy to synthesize and prepare, and can be matched with a main material and a sensitizer to further improve the performance of the device.

In an alternative embodiment, the fluorescent dye is selected from any one or at least two combinations of compounds shown as M-1 to M-122 (e.g., a combination of M-1 and M-20, a combination of M-5 and M-11, or a combination of M-8, M-100, and M-122):

the fluorescent dyes used in the present invention can be prepared by conventional methods, illustratively providing the following representative synthetic routes:

representative synthetic route 1:

representative synthetic route 2:

it should be noted that the fluorescent dye obtained in the present invention is not limited to the synthesis method and raw materials used in the present invention, and those skilled in the art can select other methods or routes to obtain the compound proposed in the present invention.

In an alternative embodiment, the host material is selected from any one or combination of at least two of the following compounds TDH-1 to TDH-30 (e.g., TDH-1 and TDH-4, TDH-6 and TDH-18, or TDH-3, TDH-6 and TDH-20):

in an alternative embodiment, the thermally activated delayed fluorescence sensitizer is selected from any one or at least two combinations of the following compounds TDE1 to TDE37 (e.g., a combination of TDE7 and TDE10, a combination of TDE8 and TDE17, or a combination of TDE6, TDE8, and TDE 20):

in an alternative embodiment, the mass of the fluorescent dye accounts for 0.1-10% (may be simply referred to as doping concentration) of the total mass of the light-emitting layer, and is preferably 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.8%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, etc., and preferably 1%.

Aiming at the fluorescent dye with a specific structure selected by the invention, the doping concentration of the fluorescent dye in a light-emitting layer is further optimized, the performance of a TASF device is further improved within the concentration range, and the doping amount is too low, so that fewer dye molecules participating in light emission are generated, and the efficiency of the device is lower. Too high doping can lead to increased quenching of the dye in the device, resulting in poor device efficiency and poor operating voltage.

In an alternative embodiment, the mass of the sensitizer accounts for 1% to 99% of the total mass of the light emitting layer, and is preferably 2%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, and the like, and is preferably 10% to 50%.

In an optional embodiment, the organic layer further includes any one or at least two combinations of a Hole Injection Layer (HIL), a Hole Transport Layer (HTL), a Hole Blocking Layer (HBL), an Electron Blocking Layer (EBL), an Electron Transport Layer (ETL), or an Electron Injection Layer (EIL).

Embodiments of the present invention also provide a display apparatus, which includes the organic electroluminescent device provided as above. The display device can be specifically an OLED display panel, and any product or component with a display function, such as a television, a digital camera, a mobile phone, a tablet computer and the like, comprising the display panel. The display device has the same advantages as the organic electroluminescent device compared with the prior art, and the description is omitted here.

It is to be understood that the first electrode and the second electrode represent an anode and a cathode, respectively, in the present invention.

The hole transport region, the electron transport region, the anode, and the cathode of the present invention will be described below. The hole transport region is located between the anode and the light emitting layer. The hole transport region may be a hole transport layer of a single layer structure including a single layer containing only one compound and a single layer containing a plurality of compounds. The hole transport region may also be a multilayer structure including at least two layers of a hole injection layer, a hole transport layer, and an electron blocking layer.

The materials of the hole transport region, including HIL and HTL, may be selected from, but are not limited to, phthalocyanine derivatives such as CuPc, conductive polymers or polymers containing conductive dopants such as polyphenylenevinylene, polyaniline/dodecylbenzenesulfonic acid (Pani/DBSA), poly (3, 4-ethylenedioxythiophene)/poly (4-styrenesulfonate) (PEDOT/PSS), polyaniline/camphorsulfonic acid (Pani/CSA), polyaniline/poly (4-styrenesulfonate) (Pani/PSS), aromatic amine derivatives.

Among them, the aromatic amine derivatives may be compounds shown below as HT-1 to HT-34. If the material of the hole transport region is an aromatic amine derivative, it may be one or at least two combinations of compounds represented by HT-1 to HT-34 (e.g., a combination of HT-5 and HT-8, or a combination of HT-11, HT-12, and HT-15, etc.).

The hole injection layer is located between the anode and the hole transport layer. The hole injection layer may be a single compound material or a combination of a plurality of compounds. For example, the hole injection layer may employ one or at least two compounds of HT-1 to HT-34 described above, or employ one or at least two combinations of HI-1-HI-3 described below; one or at least two combinations of the following HI-1-HI-3 (e.g., a combination of HI-1 and HI-2, etc.) may also be doped with one or at least two combinations of HT-1 to HT-34.

The electron transporting region may be a single-layer structure of the electron transporting layer, including a single-layer electron transporting layer containing only one compound and a single-layer electron transporting layer containing a plurality of compounds. The electron transport region may also be a multilayer structure including at least two layers of an electron injection layer, an electron transport layer, and a hole blocking layer.

Further, in the embodiment of the present invention, the electron transport layer material may be selected from, but not limited to, one or a combination of at least two of ET-1 to ET-65 listed below (e.g., a combination of ET-2 and ET-9 or a combination of ET-12, ET-17 and ET-33, etc.).

In an alternative embodiment, the hole blocking material in the hole blocking layer is selected from any one or at least two combinations of the compounds represented by the following HB-1 to HB-6 (e.g., the combination of HB-1 and HB-2, the combination of HB-5, HB-6 and HB-4, the combination of HB-1, HB-3, HB-4 and HB-6, etc.):

in an alternative embodiment, the electron blocking material of the electron blocking layer is selected from any one or at least two combinations of the compounds shown in the following EB-1 to EB-21, compounds TDH-1 to TDH-30:

in an alternative embodiment, the electron injection material in the electron injection layer comprises any one or a combination of at least two of the following compounds:

Liq、LiF、NaCl、CsF、Li ₂ O、Cs ₂ CO ₃ 、BaO、Na、Li、Ca、Mg、Ag、Yb。

in an alternative embodiment, a substrate may be used either below the first electrode or above the second electrode. The substrate is a glass or polymer material having excellent mechanical strength, thermal stability, water resistance, and transparency. Further, a Thin Film Transistor (TFT) may be provided on a substrate for a display.

In an alternative embodiment, the first electrode may be formed by sputtering or depositing a material used as the first electrode on the substrate. When the first electrode is used as an anode, Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), tin dioxide (SnO) may be used ₂ ) And transparent conductive oxide materials such as zinc oxide (ZnO), and any combination thereof. When the first electrode is used as a cathode, a metal or an alloy such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), or any combination thereof can be used.

The device can be coated with a light extraction layer (CPL layer) by evaporation above the cathode so as to improve the efficiency of the device and adjust the optical microcavity.

The thicknesses of the various layers described above may be those conventional in the art.

The invention also provides a preparation method of the organic electroluminescent device, which comprises the steps of depositing the anode, the hole transmission area, the luminescent layer, the electron transmission area and the cathode on the substrate in sequence, and then packaging. Wherein, when preparing the luminescent layer, a multi-source co-evaporation method is utilized. The anode, the hole transport region, the electron transport region and the cathode are deposited in the same manner as the conventional manner in the art.

The following synthesis example exemplarily shows a specific synthesis method of the fluorescent dye, and the analytical detection of the compound thereof uses an ABCIEX mass spectrometer (4000 QTRAP).

Synthesis example 1: synthesis of M-1

(1) Preparation of intermediate M1-1:

4-bromoaniline (43g, 250mmol), 1, 3-dimethylbenzeneboronic acid (37.5g, 250mmol), tetrakis (triphenylphosphine) palladium (8.66g, 7.5mmol) and potassium carbonate (69g, 500mmol) are added to a 2L single-neck flask, 1000ml of 1, 4 dioxane and 250ml of water are added, and the mixture is heated under nitrogen atmosphere at 110 ℃ for reaction for 20 h.

After the system was cooled, 1000ml of ethyl acetate was added to the reaction system, filtration was performed, the organic phase was washed with 400ml of concentrated hydrochloric acid, liquid separation was performed, the PH of the aqueous phase was adjusted to be alkaline with sodium hydroxide, extraction was performed with 200ml of dichloromethane x 3, the organic phases were combined, concentrated under reduced pressure, and purification was performed by column chromatography. Intermediate M1-139.8 g was obtained.

(2) Synthesis of intermediate M1-2:

intermediate M1-1(31.7, 160mmol) was charged into a 2L three-necked flask, and 4-tert-butylbromobenzene (40.4g, 190mmol), [1,1\ bis (diphenylphosphino) ferrocene ] dichloropalladium (2.3g, 3.1mmol), sodium tert-butoxide (22.8g, 237mmol) were added and reacted overnight at 110 ℃ under 800ml of toluene nitrogen, and the reaction was stopped and purified by column chromatography. After purification, intermediate M1-229.7 g was obtained.

(3) Synthesis of intermediate M1-3:

intermediate M1-2(26.4g, 80mmol), 2, 6-dibromo-4-methylchlorobenzene (10.4g, 37mmol), tris (dibenzylideneacetone) dipalladium (1.72g, 1.88mmol), 2-dicyclohexylphosphine-2 ',6' -dimethoxybiphenyl (2.32g, 5.64mmol), sodium tert-butoxide (10.85g, 113mmol) and 1L toluene were charged into a 2000ml three-necked flask, reacted overnight at 110 ℃ under nitrogen protection, stopped, and purified by column chromatography. After purification, intermediate M1-316.5 g was obtained.

(4) Synthesis of Compound M-1:

m1-3(7.8g, 10mmol) was added to a 500ml three-necked flask, p-tert-butylbenzene (150ml) was added, the reaction was cooled to 0 ℃ after stirring for 20 minutes, 15mmol tert-butyllithium was added, and stirring was continued for 30 minutes while maintaining the low temperature. Then gradually heating to 60 ℃ and continuously heating for 3 h. Finally, the temperature of the reaction system is reduced to 0 ℃ again, boron tribromide (5.1g, 20mmol) is added under the protection of nitrogen, and diisopropylethylamine (13g, 80mmol) is added after stirring for 30 minutes. Finally, the reaction system is heated to 60 ℃ to react for 12 h. After the reaction was cooled to room temperature, the organic phase was spin-dried under reduced pressure. Ethyl acetate (200ml) was extracted three times, and the organic phases were combined and dried over anhydrous sodium sulfate. The organic phase is mixed with silica gel for concentration, column chromatography is carried out to obtain 3.4g of crude product, toluene/n-hexane is recrystallized to obtain 2.1g of yellow solid with the purity of 99.71 percent. Mass spectrometric determination of molecular ion mass: 754.86 (theoretical value: 754.44).

Synthesis example 2: synthesis of M-3

(1) Preparation of intermediate M3-1:

3-bromoaniline (43g, 250mmol), 1, 3-dimethylphenylboronic acid (37.5g, 250mmol), tetrakis (triphenylphosphine) palladium (8.66g, 7.5mmol), potassium carbonate (69g, 500mmol) were added to a 2L one-neck flask, 1000ml of 1, 4-dioxane and 250ml of water were added, and the mixture was heated under nitrogen atmosphere at 110 ℃ for 20 h.

After the system was cooled, 1000ml of ethyl acetate was added to the reaction system, filtration was performed, the organic phase was washed with 400ml of concentrated hydrochloric acid, liquid separation was performed, the PH of the aqueous phase was adjusted to be alkaline with sodium hydroxide, extraction was performed with 200ml of dichloromethane x 3, the organic phases were combined, concentrated under reduced pressure, and purification was performed by column chromatography. Intermediate M3-142.2 g can be obtained.

(2) Preparation of intermediate M3-2:

the synthesis scheme was as for M1-2, and column chromatography gave 36.9g of a solid.

(3) Preparation of intermediate M3-3:

the synthesis scheme was as for M1-3, and column chromatography gave 17.9g of a white solid.

(4) Synthesis of Compound M-3:

synthesis protocol As for M-1, M1-3 was replaced with M3-3(10mmol) to give 3.95g of a yellow solid of 99.17% purity.

Mass spectrometric analysis determined molecular ion mass: 754.75 (theoretical value: 754.44).

Other compounds were synthesized analogously according to the general synthesis formula and confirmed by mass spectrometry with the following results:

compound numbering	Theoretical value of mass spectrum	Mass spectrometry test data
			M-8	1002.51	1002.68
M-9	858.51	858.72
			M-11	886.54	886.69
M-24	1064.52	1064.84
			M-29	740.43	740.64
M-32	988.49	988.69
			M-53	756.44	756.56
M-57	742.42	742.59
			M-65	794.38	794.49
M-69	850.45	850.60
			M-73	780.82	780.96
M-81	954.51	954.66
			M-97	766.36	766.57
M-98	734.40	734.53
			M-112	798.38	798.51
M-117	754.45	754.62
			M-121	854.48	854.61

The organic electroluminescent device according to the invention is further illustrated by the following specific examples.

Examples 1 to 27, comparative examples 1 to 4

The above embodiments and comparative examples respectively provide an organic electroluminescent device, which has a structure as shown in fig. 1, and sequentially includes an anode, a Hole Injection Layer (HIL), a Hole Transport Layer (HTL), an Electron Blocking Layer (EBL), an emission layer (EML), a Hole Blocking Layer (HBL), an Electron Transport Layer (ETL), an Electron Injection Layer (EIL), and a cathode from bottom to top, wherein the emission layer includes a combination containing a host material, a thermally activated delayed fluorescence sensitizer, and a fluorescent dye, and specific material selection and doping amount are detailed in table 1.

The specific preparation method of the organic electroluminescent device comprises the following steps:

(1) the glass plate coated with the ITO transparent conductive layer was sonicated in a commercial detergent, rinsed in deionized water, washed in acetone: ultrasonically removing oil in an ethanol mixed solvent, baking in a clean environment until the water is completely removed, cleaning by using ultraviolet light and ozone, and bombarding the surface by using low-energy cationic beams;

(2) placing the glass substrate with the anode in a vacuum chamber, and vacuumizing to less than 1 × 10 ^-5 Pa, performing vacuum evaporation on the anode layer film to obtain HI-3 serving as a hole injection layer, wherein the evaporation rate is 0.1nm/s, and the evaporation film thickness is 2 nm;

(3) vacuum evaporating a hole transport layer HT-28 on the hole injection layer, wherein the evaporation rate is 0.1nm/s, and the total film thickness of the evaporation is 30 nm;

(4) vacuum evaporating an electron blocking layer EB-12 on the hole transmission layer, wherein the evaporation rate is 0.1nm/s, and the total film thickness is 5 nm;

(5) and (3) vacuum evaporating a light-emitting layer on the electron blocking layer, wherein the light-emitting layer comprises a main body material, a sensitizer and fluorescent dye, and the main body evaporation rate is 0.1nm/s and the evaporation film thickness is 30nm by using a multi-source co-evaporation method.

(6) Vacuum evaporating HB-5 on the luminescent layer as a hole blocking layer, wherein the evaporation rate is 0.1nm/s, and the total film thickness is 5 nm;

(7) evaporating ET-60 and ET-57 as electron transport layers on the hole blocking layer in vacuum at a ratio of 1:1, at an evaporation rate of 0.1nm/s and at a total film thickness of 25 nm;

(8) liq with the thickness of 1nm is vacuum-evaporated on the electron transport layer to be used as an electron injection layer, and an Al layer with the thickness of 150nm is used as a cathode of the device.

Among them, the fluorescent dyes used in comparative examples 1 to 4 have the structures of ref-1, ref-2, ref-3 and ref-4, respectively:

testing the performance of the device:

(1) the driving voltage and external quantum efficiency of the organic electroluminescent devices prepared in the above device examples and comparative examples were measured at the same brightness using a digital source table and PR 650. Specifically, the voltage was raised at a rate of 0.1V per second, and it was determined that the luminance of the organic electroluminescent device reached 1000cd/m ² The voltage is the driving voltage under the corresponding brightness, and the external quantum efficiency (EQE,%) of the device can be directly tested on PR 650;

the test results are shown in table 1.

TABLE 1

As can be seen from table 1, the fluorescent dye with a specific structure is introduced into the light-emitting layer of the TASF device, and compared with the dye in the prior art, the fluorescent dye can effectively improve the device performance, specifically, the driving voltage is reduced, and the external quantum efficiency is improved.

Comparative examples 1-4 are structurally different from the fluorescent dyes used in the present invention and the data show that the devices of comparative examples 1-4 are significantly less efficient than the present invention. Among them, the compound ref-2 used in comparative example 2 is different from M-1 of the present invention only in that the biphenyl group has no substituted methyl group, and its efficiency and voltage are remarkably poor under the same conditions as other conditions in the device.

It can be seen from comparative examples 1-5 that the performance of the TASF device can be further improved when the doping ratio of the fluorescent dye of the present invention is controlled to be in the range of 0.1% -10% (examples 2-4), wherein the effect is best when the doping amount is 1% (example 3).

It is understood from comparison between example 3 and example 10 that the substitution of alkyl groups on ring X and ring Y (example 3) is advantageous in further improving the device performance as compared with the case of the substitution of phenyl groups (example 10).

By comparing example 3 with example 11, Ar ¹ And Ar ² The fluorescent dye having a symmetric structure (example 3) is advantageous in further improving the device performance compared to the asymmetric structure (example 11).

By comparing example 3 with example 12, Ar ¹ And Ar ² The fluorescent dye (example 3) in which the monocyclic aryl group is directly bonded to the N atom is more advantageous in improving the device performance than the case of the condensed-ring aryl group (example 12).

The applicant states that the present invention is illustrated in detail by the above examples, but the present invention is not limited to the above detailed methods, i.e. it is not meant that the present invention must rely on the above detailed methods for its implementation. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.

Claims

1. An organic electroluminescent device comprising a first electrode, a second electrode, and an organic layer between the first and second electrodes;

in formula (1):

Ar ¹ with or without rings, Ar, between adjacent rings X or Z ² Form a ring or not form a ring with the adjacent ring Y or ring Z;

in the formula (G):

Y ¹ ～Y ³ each independently selected from CR ¹ Or N, R ¹ Independently selected from hydrogen, halogen, cyano, nitro, hydroxy, amino, substituted or unsubstitutedC1-C20 chain alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C1-C20 silyl, substituted or unsubstituted C6-C60 arylamino, substituted or unsubstituted C3-C60 heteroarylamino, substituted or unsubstituted C6-C60 aryl, and substituted or unsubstituted C3-C60 heteroaryl, wherein R is one of the R ¹ Independently with the linked aromatic or heteroaromatic ring to form a ring or not;

n is an integer of 1-5;

2. The organic electroluminescent device according to claim 1, wherein in formula (1), at least one of the ring X, ring Y and ring Z is a group represented by formula (a):

in the formula (a), Z ¹ 、Z ² 、Z ³ And Z ⁴ Independently selected from CR ² Or N, said R ² Independently selected from hydrogen, halogen, cyano, carbonyl, nitro, hydroxyl, amino, C1-C20 chain alkyl, C3-C20 cycloalkyl, C1-C20 alkoxy, C1-C20 silyl, C6-C60 arylamino, C6-C60, one of heteroaryl amino, C6-C60 aryl and C3-C60 heteroaryl, wherein R is ² Independently with the attached aromatic or heteroaromatic ring, or not.

3. The organic electroluminescent device according to claim 2, wherein the structure of formula (1) is represented by the following formula (2):

4. The organic electroluminescent device according to claim 3, wherein R is ² 、R ³ 、R ⁴ Are respectively and independently selected from one of C1-C20 chain alkyl and C3-C20 naphthenic base.

5. The organic electroluminescent device according to claim 4, wherein R is ² 、R ³ 、R ⁴ Each independently selected from one of the following groups:

6. the organic electroluminescent device according to claim 1, wherein the Ar is Ar ¹ And Ar ² Selected from the same group.

7. The organic electroluminescent device according to claim 1, wherein in formula (G), L is ¹ Selected from the group consisting of groups represented by the formula (L-1) or the formula (L-2):

in the formula (L-2), M is selected from O, S or NR ⁶ In a group of (A), the R ⁶ Independently selected from one of hydrogen, halogen, cyano, carbonyl, nitro, hydroxyl, amino, C1-C20 chain alkyl, C3-C20 cycloalkyl, C1-C20 alkoxy, C1-C20 silyl, C6-C60 arylamino, C6-C60 heteroarylamino, C6-C60 aryl and C3-C60 heteroaryl, wherein R is selected from one of C3-C20 heteroaryl ⁶ Independently with attached aromatic ringsOr the heteroaromatic rings may or may not be linked to form a ring.

8. The organic electroluminescent device according to claim 7, wherein M is selected from O or S.

9. The organic electroluminescent device according to claim 7, wherein the formula (G) is selected from structures represented by any one of the following formulae (G-1) to (G-6):

said X ¹ ～X ⁵ And M is as defined in the formula (L-1) and the formula (L-2), respectively; said Y is ¹ ～Y ³ 、R ^a And R ^b Are as defined in formula (G), respectively.

10. The organic electroluminescent device according to claim 1, wherein R is ^a And R ^b At least one of the alkyl groups is one of substituted or unsubstituted C1-C20 chain alkyl groups and substituted or unsubstituted C3-C20 cycloalkyl groups.

11. The organic electroluminescent device according to claim 10, wherein R is ^a And R ^b At least one of the above groups is one of methyl, ethyl, tert-butyl, isopropyl, cyclohexyl and fluorine.

12. The organic electroluminescent device according to claim 1, wherein the fluorescent dye is selected from any one or at least two combinations of compounds shown as M-1 to M-122:

13. the organic electroluminescent device according to claim 1, wherein the host material is selected from any one or a combination of at least two of the following compounds TDH-1 to TDH-30:

14. the organic electroluminescent device according to claim 1, wherein the thermally activated delayed fluorescence sensitizer is selected from any one or at least two combinations of the following compounds TDE1 to TDE 37:

15. the organic electroluminescent device according to claim 1, wherein the fluorescent dye accounts for 0.1 to 10% by mass of the total mass of the light emitting layer.

16. The organic electroluminescent device according to claim 1, wherein the organic layer further comprises any one or a combination of at least two of a hole injection layer, a hole transport layer, a hole blocking layer, an electron transport layer, or an electron injection layer.

17. A display device comprising the organic electroluminescent device according to any one of claims 1 to 16.