CN111834537B

CN111834537B - Organic electroluminescent device comprising light extraction layer

Info

Publication number: CN111834537B
Application number: CN202010686052.4A
Authority: CN
Inventors: 李涛; 杨曦; 潘君友; 龙芷君
Original assignee: Guangzhou Chinaray Optoelectronic Materials Ltd; Wuhan China Star Optoelectronics Semiconductor Display Technology Co Ltd
Current assignee: Guangzhou Chinaray Optoelectronic Materials Ltd; Wuhan China Star Optoelectronics Semiconductor Display Technology Co Ltd
Priority date: 2019-07-18
Filing date: 2020-07-16
Publication date: 2023-07-28
Anticipated expiration: 2040-07-16
Also published as: CN111834537A

Abstract

The invention relates to an organic electroluminescent device comprising two electrodes, one or more functional layers arranged between the two electrodes and a light extraction layer arranged over an electrode. The light extraction layer material is a carbazole-containing compound having a suitable energy level, a high extinction coefficient in the near ultraviolet region (300 nm-400 nm), and a high refractive index in the visible region. The organic electroluminescent display device can reduce the damage of external high-energy light to internal materials of the organic electroluminescent display device, effectively reduce the loss of visible light in the device, promote light extraction and improve the luminous efficiency of the device.

Description

Organic electroluminescent device comprising light extraction layer

The present application claims priority from the chinese patent office, application number 2019106480791, entitled "organic electroluminescent device comprising light extraction layer," filed on 7/18 2019, the entire contents of which are incorporated herein by reference.

Technical Field

The invention relates to the technical field of organic electroluminescence, in particular to an organic electroluminescent device with an organic compound with a higher refractive index as a light extraction layer, and further relates to a polycarbazole compound and application thereof in the field of organic electroluminescence.

Background

The organic electroluminescent display device is a self-luminous display device, which generates excitons by transfer and recombination of carriers between functional layers, and emits light by means of organic compounds or metal complexes having high quantum efficiency. The light source has the characteristics of self-luminescence, high brightness, high efficiency, high contrast, high responsiveness and the like.

In recent years, the luminous efficiency of organic electroluminescent diodes (OLEDs) has been greatly improved, but the internal quantum efficiency thereof has been approaching the theoretical limit. Therefore, improving the light extraction efficiency becomes an effective means for further improving the device stability and current efficiency (e.g., accumulation of the emissive layer metal complex, matching of refractive indices between functional layers, etc.). In 2001, hung et al covered a layer of organic or inorganic compound at about 50nm on the surface of the metal cathode to improve the performance of the device by controlling the thickness and refractive index. In 2003, riel et al have attempted to vapor-deposit an inorganic compound ZnSe having a high refractive index (n=2.6) on a cathode, to improve light extraction efficiency by utilizing the difference in refractive index between functional layers, but such compounds have not been used more in organic electroluminescent devices due to high evaporation temperature, slow evaporation rate of inorganic materials, and the like.

For the above reasons, there have been attempts to use organic compounds having a higher refractive index in electroluminescent devices to improve light extraction efficiency. The compounds need to meet the following conditions: the extinction coefficient is high in the ultraviolet band (less than 400 nm), and adverse effects of harmful light on device materials are avoided; the extinction coefficient is close to 0 in the visible light range (> 430 nm), the visible light has higher transmissivity, and the influence on the light-emitting efficiency of the equipment is reduced; the light-emitting diode has the characteristics of higher refractive index in the visible light range, smaller difference, light emission improvement, device structure optimization and the like; has higher glass transition temperature and improves the thermal stability of the compound.

Therefore, a new class of materials for improving the light extraction efficiency of organic electroluminescent devices needs to be further developed.

Disclosure of Invention

In view of the foregoing deficiencies of the prior art, it is a primary object of the present invention to provide an organic electroluminescent device having an organic compound with a relatively high refractive index as a light extraction layer, for improving the light extraction efficiency of the device. The invention further provides a compound containing polycarbazole and application thereof in the field of organic electroluminescence.

The technical scheme of the invention is as follows:

The invention relates to an organic electroluminescent device comprising two electrodes, one or more organic functional layers arranged between the two electrodes and a light extraction layer arranged on one electrode, which is characterized in that: the light extraction layer material comprises a compound represented by the general formula (1):

wherein:

q is selected from N (R) ₁ ) _3-n Or a substituted or unsubstituted aromatic group having 5 to 30 ring atoms, a substituted or unsubstituted heteroaromatic group having 5 to 30 ring atoms, or a compound havingA substituted or unsubstituted non-aromatic ring system having 3 to 30 ring atoms;

n≥2；

a is independently selected from structural formula (2) at each occurrence

Ar ₁ 、Ar ₂ Each occurrence is independently selected from a substituted or unsubstituted aromatic group having 5 to 60 ring atoms, a substituted or unsubstituted heteroaromatic group having 5 to 60 ring atoms, or a non-aromatic ring system having 3-25 ring atoms;

x is independently selected at each occurrence from the absence or one of the following groups:

the dotted line represents X and Ar ₁ 、Ar ₂ A bonded key; * Representing the ligation site

R ₁ -R ₃ Independently at each occurrence, selected from the group consisting of hydrogen, D, straight chain alkyl having 1 to 20C atoms, alkoxy having 1 to 20C atoms, thioalkoxy having 1 to 20C atoms, branched alkyl having 3 to 20C atoms, cyclic alkyl having 3 to 20C atoms, alkoxy having 3 to 20C atoms, thioalkoxy having 3 to 20C atoms, silyl, keto having 1 to 20C atoms, alkoxycarbonyl having 2 to 20C atoms, aryloxycarbonyl having 7 to 20C atoms, cyano, carbamoyl, haloformyl, formyl, isocyano, isocyanate, thiocyanate, isothiocyanate, hydroxy, nitro, CF ₃ Cl, br, F, a crosslinkable group, a substituted or unsubstituted aromatic group having 5 to 60 ring atoms, a substituted or unsubstituted heteroaromatic group having 5 to 60 ring atoms, a substituted or unsubstituted aryloxy group having 5 to 60 ring atoms, or a substituted or unsubstituted heteroaryloxy group having 5 to 60 ring atomsClusters, or combinations of these systems;

when Q is selected from an aromatic group or a heteroaromatic group, the attachment sites of the multiple substituents a on Q are not adjacent nor opposite.

The invention further relates to a compound selected from the structures according to formula (5):

wherein:

q is selected from N (R) ₁ ) _3-n Or a substituted or unsubstituted aromatic group having 5 to 30 ring atoms, a substituted or unsubstituted heteroaromatic group having 5 to 30 ring atoms, or a non-aromatic ring system having 3 to 30 ring atoms;

n≥2；

a is independently selected from structural formula (6) at each occurrence

W is independently selected from O or S for each occurrence; * Represents a ligation site;

Ar ₂ each occurrence is independently selected from a substituted or unsubstituted aromatic group having 5 to 60 ring atoms, a substituted or unsubstituted heteroaromatic group having 5 to 60 ring atoms, or a non-aromatic ring system having 3-25 ring atoms;

R ₁ Independently at each occurrence, selected from the group consisting of hydrogen, D, straight chain alkyl having 1 to 20C atoms, alkoxy having 1 to 20C atoms, thioalkoxy having 1 to 20C atoms, branched alkyl having 3 to 20C atoms, cyclic alkyl having 3 to 20C atoms, alkoxy having 3 to 20C atoms, thioalkoxy having 3 to 20C atoms, silyl, keto having 1 to 20C atoms, alkoxycarbonyl having 2 to 20C atoms, aryloxycarbonyl having 7 to 20C atoms, cyano, carbamoyl, haloformyl,formyl, isocyano, isocyanate, thiocyanate, isothiocyanate, hydroxy, nitro, CF ₃ Cl, br, F, a crosslinkable group, a substituted or unsubstituted aromatic group having from 5 to 60 ring atoms, a substituted or unsubstituted heteroaromatic group having from 5 to 60 ring atoms, a substituted or unsubstituted aryloxy group having from 5 to 60 ring atoms, or a substituted or unsubstituted heteroaryloxy group having from 5 to 60 ring atoms, or a combination of these systems;

The invention also relates to a composition comprising at least one compound as described above and at least one organic solvent.

The invention also relates to a light extraction layer comprising the above compound or the above composition.

The beneficial effects are that:

the polycarbazole compound disclosed by the invention is used as a light extraction layer material of an organic electroluminescent device, has a higher glass transition temperature and has higher thermal stability. The extinction coefficient is high in the ultraviolet band, smaller in the visible light range and higher in refractive index. When used as a light extraction layer of an electronic device, the light extraction layer can avoid adverse effects of harmful light on materials inside the device and improve the light extraction efficiency of visible light.

Drawings

Fig. 1 is a schematic diagram of an embodiment of a device. Wherein 1 is a substrate, 2 is an anode, 3a is a Hole Injection Layer (HIL), 3b is a Hole Transport Layer (HTL), 3c is a light emitting layer, 3d is an Electron Transport Layer (ETL), 3e is an Electron Injection Layer (EIL), 4 is a cathode, and 5 is a light extraction layer.

FIG. 2 is the UV-visible absorption spectrum of a synthesis example C-3 in methylene chloride solution.

FIG. 3 shows the refractive index and extinction coefficient of a synthetic example C-3.

Detailed Description

The present invention provides an organic electroluminescent device comprising a polycarbazole-containing compound as a material for a light extraction layer. The invention also relates to a compound containing the heteroatom five-membered ring and carbazole. The present invention will be described in further detail below in order to make the objects, technical solutions and effects of the present invention more clear and distinct. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.

In the present invention, "substituted" means that a hydrogen atom in a substituted group is substituted by a substituent.

In the present invention, "substituted or unsubstituted" means that the defined group may or may not be substituted. When a defined group is substituted, it is understood to be optionally substituted with groups acceptable in the art, including but not limited to: c (C) _1-30 Alkyl, cycloalkyl containing 3 to 20 ring atoms, heterocyclyl containing 3 to 20 ring atoms, aryl containing 5 to 20 ring atoms, heteroaryl containing 5 to 20 ring atoms, silyl, carbonyl, alkoxycarbonyl, aryloxycarbonyl, carbamoyl, haloformyl, formyl, -NRR', cyano, isocyano, thiocyanate, isothiocyanate, hydroxy, trifluoromethyl, nitro or halogen, and which may be further substituted with substituents acceptable in the art; it is understood that R and R 'in-NRR' are each independently substituted with a group acceptable in the art, including but not limited to H, C _1-6 Alkyl, cycloalkyl having 3 to 8 ring atoms, heterocyclyl having 3 to 8 ring atoms, aryl having 5 to 20 ring atoms or heteroaryl having 5 to 10 ring atoms; the C is _1-6 Alkyl, cycloalkyl having 3 to 8 ring atoms, heterocyclyl having 3 to 8 ring atoms, aryl having 5 to 20 ring atoms, or heteroaryl having 5 to 10 ring atoms is optionally further substituted with one or more of the following groups: c (C) _1-6 Alkyl, cycloalkyl having 3 to 8 ring atoms, heterocyclyl having 3 to 8 ring atoms, halogen, hydroxy, nitro or amino.

In the present invention, the "number of ring atoms" means the number of atoms among atoms constituting the ring itself of a structural compound (for example, a monocyclic compound, a condensed ring compound, a crosslinked compound, a carbocyclic compound, a heterocyclic compound) in which atoms are bonded to form a ring. When the ring is substituted with a substituent, the atoms contained in the substituent are not included in the ring-forming atoms. The same applies to the "number of ring atoms" described below, unless otherwise specified. For example, the number of ring atoms of the benzene ring is 6, the number of ring atoms of the naphthalene ring is 10, and the number of ring atoms of the thienyl group is 5.

In the present invention, "the substituent group-linking sites are not adjacent" means that these groups are not bonded to the same carbon atom or to adjacent carbon atoms or to positions between two carbon atoms where there is no substituent, specifically in three ways:

In the present invention, the term "the substituent group connecting site is not relative" means that in a molecular structure having a symmetry axis or symmetry center of 2 times, particularly in an aromatic group or a heteroaromatic group, a substituent cannot be bonded to two sites which are at symmetry positions and are farthest from each other, and two sites at symmetry positions mean that the same substituent group replaces either of the two sites, thereby obtaining the same molecular structure. For example:

an aromatic group refers to a hydrocarbon group containing at least one aromatic ring. Heteroaromatic groups refer to aromatic hydrocarbon groups containing at least one heteroatom. The heteroatoms are preferably selected from Si, N, P, O, S and/or Ge, particularly preferably from Si, N, P, O and/or S. Fused ring aromatic group means that the ring of the aromatic group may have two or more rings in which two carbon atoms are shared by two adjacent rings, i.e., fused rings. Fused heterocyclic aromatic groups refer to fused ring aromatic hydrocarbon groups containing at least one heteroatom. For the purposes of the present invention, aromatic or heteroaromatic groups include not only aromatic ring systems but also non-aromatic ring systems. Thus, systems such as pyridine, thiophene, pyrrole, pyrazole, triazole, imidazole, oxazole, oxadiazole, thiazole, tetrazole, pyrazine, pyridazine, pyrimidine, triazine, carbene, and the like are also considered aromatic or heterocyclic aromatic groups for the purposes of this invention. For the purposes of the present invention, fused-ring aromatic or fused-heterocyclic aromatic ring systems include not only aromatic or heteroaromatic systems, but also systems in which a plurality of aromatic or heterocyclic aromatic groups may also be interrupted by short non-aromatic units (< 10% of non-H atoms, preferably less than 5% of non-H atoms, such as C, N or O atoms). Thus, for example, systems such as 9,9' -spirobifluorene, 9-diaryl fluorene, triarylamine, diaryl ether, and the like are also considered fused ring aromatic ring systems for the purposes of this invention.

In the present invention, the "light extraction layer" refers to a layer located on the surface of one electrode of the organic electroluminescent device opposite to the surface facing the organic functional layer, i.e., the surface facing away from the organic functional layer;

an organic electroluminescent device comprising two electrodes, one or more organic functional layers disposed between the two electrodes, and a light extraction layer disposed over an electrode, the light extraction layer material comprising a compound represented by the general formula (1):

wherein:

n≥2；

a is independently selected from structural formula (2) at each occurrence

Ar ₁ 、Ar ₂ Each occurrence is independently selected from the group consisting of a substituted or unsubstituted aromatic group having 5 to 60 ring atoms, a substituted or unsubstituted hetero ring having 5 to 60 ring atomsAn aromatic group, or a non-aromatic ring system having 3 to 25 ring atoms which may be substituted or unsubstituted;

the dotted line represents X and Ar ₁ 、Ar ₂ A bonded key; * Represents a ligation site;

R ₁ -R ₃ Independently at each occurrence, selected from the group consisting of hydrogen, D, straight chain alkyl having 1 to 20C atoms, alkoxy having 1 to 20C atoms, thioalkoxy having 1 to 20C atoms, branched alkyl having 3 to 20C atoms, cyclic alkyl having 3 to 20C atoms, alkoxy having 3 to 20C atoms, thioalkoxy having 3 to 20C atoms, silyl, keto having 1 to 20C atoms, alkoxycarbonyl having 2 to 20C atoms, aryloxycarbonyl having 7 to 20C atoms, cyano, carbamoyl, haloformyl, formyl, isocyano, isocyanate, thiocyanate, isothiocyanate, hydroxy, nitro, CF ₃ Cl, br, F, a crosslinkable group, a substituted or unsubstituted aromatic group having from 5 to 60 ring atoms, a substituted or unsubstituted heteroaromatic group having from 5 to 60 ring atoms, a substituted or unsubstituted aryloxy group having from 5 to 60 ring atoms, or a substituted or unsubstituted heteroaryloxy group having from 5 to 60 ring atoms, or a combination of these systems;

In a preferred embodiment, when there are a plurality of a, the a's are identical to each other.

In a preferred embodiment, X in formula (2) is selected from the absence, i.e., formula (2) is described by the following formula:

in certain embodiments, each occurrence of X in formula (2) is independently selected from one of the following groups:

in one embodiment, each occurrence of X in formula (2) is selected from the same group; in another embodiment, X is selected to be absent for each occurrence; in one embodiment, X is selected from the group consisting of, for each occurrence

In a preferred embodiment, Q in formula (1) is preferably selected from N (R) ₁ ) _3-n Or an aromatic group having 5 to 30 ring atoms or a heteroaromatic group having 5 to 30 ring atoms; more preferably, Q is preferably selected from NR ₁ An aromatic group having 6 to 25 ring atoms or a heteroaromatic group having 6 to 25 ring atoms; more preferably, Q is preferably selected from NR ₁ An aromatic group having 12 to 25 ring atoms or a heteroaromatic group having 12 to 25 ring atoms;

in a preferred embodiment, ar ₁ 、Ar ₂ Each occurrence is independently selected from a substituted or unsubstituted aromatic group having 5 to 60 ring atoms or a heteroaromatic group having 5 to 60 ring atoms; more preferably Ar ₁ 、Ar ₂ Each occurrence is independently selected from an aromatic group having 5 to 30 ring atoms or a heteroaromatic group having 5 to 30 ring atoms; more preferably Ar ₁ 、Ar ₂ Each occurrence is independently selected from an aromatic group having 5 to 15 ring atoms or a heteroaromatic group having 5 to 15 ring atoms.

In a preferred embodiment, ar ₁ With Ar ₂ Selected from the same groups.

In a preferred embodiment, an organic electroluminescent device according to the invention, Q, ar ₁ 、Ar ₂ Each time it appears, it selects independentlyFrom one or a combination of the following groups:

wherein: z is independently selected from CR when multiple occurrences occur ₄ Or N; w is independently selected from CR when multiple occurrences occur ₅ R ₆ ，NR ₅ O, S, c=o or Se;

R ₄ ～R ₆ each occurrence is independently selected from the group consisting of hydrogen, D, straight chain alkyl having 1 to 20C atoms, alkoxy having 1 to 20C atoms, thioalkoxy having 1 to 20C atoms, branched alkyl having 3 to 20C atoms, cyclic alkyl having 3 to 20C atoms, alkoxy having 3 to 20C atoms, thioalkoxy having 3 to 20C atoms, silyl, keto having 1 to 20C atoms, alkoxycarbonyl having 2 to 20C atoms, aryloxycarbonyl having 7 to 20C atoms, cyano, carbamoyl, haloformyl, formyl, isocyano, isocyanate, thiocyanate, isothiocyanate, hydroxy, nitro, CF ₃ Cl, br, F, a crosslinkable group, a substituted or unsubstituted aromatic group having from 5 to 60 ring atoms, a substituted or unsubstituted heteroaromatic group having from 5 to 60 ring atoms, a substituted or unsubstituted aryloxy group having from 5 to 60 ring atoms, or a substituted or unsubstituted heteroaryloxy group having from 5 to 60 ring atoms, or a combination of these systems.

Further, Q, ar ₁ 、Ar ₂ Each occurrence is independently selected from one or a combination of the following groups:

in a preferred embodiment, ar ₁ 、Ar ₂ Each occurrence is independently selected from one or a combination of the following groups:

in a more preferred embodiment, ar ₂ Selected from benzene and its derivatives at each occurrence; ar (Ar) ₁ Each occurrence is selected from fluorene, furan, benzene and derivatives thereof.

In a preferred embodiment, in accordance with the organic electroluminescent device according to the invention, the substituents a are each independently selected from one or a combination of the following groups:

wherein: ar (Ar) ₁ 、Ar ₂ And W is as defined above, represents the site of attachment to Q;

x is selected from

R ₂ 、R ₃ The meaning is as above.

Further, each occurrence of substituent A is independently selected from one or a combination of the following groups:

Wherein:

x is selected from

R ₂ 、R ₃ The meaning is as above.

in a preferred embodiment, a may select the same group in multiple occurrences; more preferably, a may choose the same structure over multiple occurrences.

In a preferred embodiment, Q may be selected from one or a combination of the following groups:

further, Q may be selected from one or a combination of the following groups:

wherein: * Represents the site of attachment to A;

R ₁ and R is ₄ Each occurrence is independently selected from: hydrogen, D, straight-chain alkyl having 1 to 20C atoms, alkoxy having 1 to 20C atoms, thioalkoxy having 1 to 20C atoms, branched alkyl having 3 to 20C atoms, cyclic alkyl having 3 to 20C atoms, alkoxy having 3 to 20C atoms, thioalkoxy having 3 to 20C atoms, silyl, keto having 1 to 20C atoms, alkoxycarbonyl having 2 to 20C atoms, aryloxycarbonyl having 7 to 20C atoms, cyano, carbamoyl, haloformyl, formyl, isocyano, isocyanate, thiocyanate, isothiocyanate, hydroxy, nitro, CF ₃ Cl, br, F, a crosslinkable group, a substituted or unsubstituted aromatic group having from 5 to 60 ring atoms, a substituted or unsubstituted heteroaromatic group having from 5 to 60 ring atoms, a substituted or unsubstituted aryloxy group having from 5 to 60 ring atoms, or a substituted or unsubstituted heteroaryloxy group having from 5 to 60 ring atoms, or a combination of these systems.

Still further, Q may be selected from one or a combination of the following groups:

in a preferred embodiment, formula (1) may be selected from any one of formulas (3-1) - (3-2):

wherein: q, ar ₁ 、Ar ₂ W is as defined above;

x is selected from

R ₂ 、R ₃ The meaning is as above.

Further, ar ₁ And Ar is a group ₂ Aryl groups each independently having 5 to 6 ring atoms or heteroaryl groups having 5 to 6 ring atoms.

Further, ar ₁ And Ar is a group ₂ All are phenyl groups.

Further, ar ₁ And Ar is a group ₂ One of which is phenyl and one of which is a 5 membered heteroaryl; further, ar ₁ And Ar is a group ₂ One of which is phenyl and one of which isFurther, ar ₁ Is->Ar ₂ Is phenyl;

further, the general formula (1) may be selected from any one of the general formulae (4-1) to (4-6):

wherein:

R ₂ 、R ₃ the meaning is as above.

In a preferred embodiment, R ₄ Selected from alkyl groups having 1 to 6C atoms, CN or any of the following groups:

E is independently selected from CR when multiple occurrences occur ₇ Or N; y is independently selected from CR when multiple occurrences occur ₇ R ₈ ，NR ₉ O or S;

R ₇ ～R ₉ each occurrence is independently selected from the group consisting of hydrogen, D, straight chain alkyl having 1 to 6C atoms, alkoxy having 1 to 6C atoms, branched alkyl having 3 to 8C atoms, cyano, isocyano, isocyanate, hydroxy, nitro, CF ₃ Cl, br, F, an aromatic group having 5 to 6 ring atoms or a heteroaromatic group having 5 to 6 ring atoms.

In one embodiment, ar in formulas (4-1) - (4-4) ₁ May be selected from phenyl or thienyl.

In a preferred embodiment, ar in formulas (4-1) - (4-4) ₁ Can be selected from thienyl, so as to improve the electron density of the molecular structure, and improve the absorption coefficient of molecules to ultraviolet band and the refractive index of the film.

Still further, formula (1) may be selected from structures as described by formula (5):

wherein:

a is independently selected from structural formula (6) at each occurrence

W is independently selected from O or S for each occurrence; preferably, W is selected from S;

Q，Ar ₂ ，R ₁ the meaning is as described above.

In a preferred embodiment, formula (1) may be selected from the following formulae:

further, the general formula (1) may be selected from the following general formulae:

wherein: r is R ₄ ，R ₅ Each occurrence is independently selected from a substituted or unsubstituted aromatic group having 5 to 60 ring atoms, a substituted or unsubstituted heteroaromatic group having 5 to 60 ring atoms, or a substituted or unsubstituted non-aromatic ring system having 3 to 25 ring atoms;

Ar ₂ W has the meaning given above.

Ar ₃ selected from a substituted or unsubstituted aromatic group having 5 to 60 ring atoms, a substituted or unsubstituted heteroaromatic group having 5 to 60 ring atoms, or a substituted or unsubstituted non-aromatic ring system having 3 to 25 ring atoms.

In one embodiment, ar ₂ Can be selected from furan, oxadiazole, benzene, pyridine and naphthalene.

In certain preferred embodiments, ar ₃ Selected from any one of the following groups:

z and W are as defined above.

Specifically, the organic electroluminescent device according to the present invention, wherein the light extraction layer material is selected from the following structures, but is not limited to:

/>

wherein: h in the above structure may be further optionally substituted.

According to the organic electroluminescent device, the material of the light extraction layer needs higher glass transition temperature, so that the thermal stability of the material of the light extraction layer is improved. In certain preferred embodiments, the glass transition temperature T _g Not less than 100deg.C, in a preferred embodiment T _g Not less than 120℃and in a preferred embodiment T _g 140℃or more, in a more preferred embodiment T _g Not less than 160℃and in a most preferred embodiment T _g ≥180℃。

In certain embodiments, the light extraction layer material has a refractive index greater than 1.7 at a wavelength of 630nm in accordance with the organic electroluminescent devices of the present invention; preferably greater than 1.78; more preferably greater than 1.83.

In other embodiments, the organic electroluminescent device according to the present invention has a singlet energy (S1) of greater than or equal to 2.7eV; preferably greater than or equal to 2.8eV; more preferably greater than or equal to 2.85eV.

In other embodiments, the organic electroluminescent device according to the present invention has a singlet energy (S1) of less than or equal to 3.1eV; preferably less than or equal to 3.0eV.

According to the organic electroluminescent device, the light extraction layer material needs a smaller extinction coefficient, and the extinction coefficient is smaller than 0.1 at the wavelength of 430 nm; preferably less than 0.003; more preferably less than 0.001. Has higher transmissivity to visible light and reduces the influence on the light-emitting efficiency of the equipment.

In certain preferred embodiments, the organic electroluminescent device according to the present invention has a light extraction layer having a relatively large extinction coefficient in the wavelength range of 400nm or less; preferentially, the extinction coefficient is more than or equal to 0.3 when the wavelength is 350 nm; preferably not less than 0.5, more preferably not less than 0.7, and most preferably not less than 1.0.

In certain preferred embodiments, the organic electroluminescent device according to the invention is an organic light emitting diode, wherein the light extraction layer is located on the cathode surface.

In a preferred embodiment, the organic electroluminescent device according to the present invention comprises one or more organic functional layers selected from one or more of an electron injection layer, an electron transport layer, a hole injection layer, a hole transport layer and a light emitting layer, wherein at least one light emitting layer is comprised.

In certain preferred embodiments, the organic electroluminescent device according to the present invention, wherein the luminescent material in the luminescent layer is selected from the group consisting of singlet emitters, triplet emitters or TADF materials.

In certain preferred embodiments, the organic electroluminescent device according to the present invention, wherein the organic functional layer is selected from the group consisting of a hole transporting layer, a light emitting layer and an electron transporting layer.

Some more detailed descriptions of singlet emitters, triplet emitters and TADF materials are provided below (but are not limited thereto).

1. Singlet state luminophor

Singlet emitters tend to have longer conjugated pi electron systems. Heretofore, there have been many examples such as styrylamine and its derivatives disclosed in JP2913116B and WO2001021729A1, indenofluorene and its derivatives disclosed in WO2008/006449 and WO2007/140847, and triarylamine derivatives of pyrene disclosed in US7233019, KR 2006-0006760.

In a preferred embodiment, the singlet light emitters may be selected from the group consisting of monobasic styrenes, dibasic styrenes, tribasic styrenes, quaternary styrenes, styrenes phosphines, styrenes ethers, and aromatic amines.

A monostyramine is a compound which comprises an unsubstituted or substituted styryl group and at least one amine, preferably an aromatic amine. A binary styrylamine is a compound comprising two unsubstituted or substituted styryl groups and at least one amine, preferably an aromatic amine. A ternary styrylamine is a compound which comprises three unsubstituted or substituted styryl groups and at least one amine, preferably an aromatic amine. A quaternary styrylamine is a compound comprising four unsubstituted or substituted styryl groups and at least one amine, preferably an aromatic amine. One preferred styrene is stilbene, which may be further substituted. The definition of the corresponding phosphines and ethers is similar to that of the amines. Aryl amine or aromatic amine refers to a compound comprising three unsubstituted or substituted aromatic or heterocyclic ring 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. Among them, preferred examples are aromatic anthraceneamines, aromatic anthracenediamines, aromatic pyrenamines, aromatic pyrenediamines, aromatic droxylamines and aromatic Qu Eran. An aromatic anthraceneamine is a compound in which a biaryl amine group is attached directly to the anthracene, preferably in the 9 position. An aromatic anthracenediamine is a compound in which two biaryl amine groups are attached directly to the anthracene, preferably in the 9,10 position. Aromatic pyrenamines, aromatic flexoamines and aromatic flexodiamines are defined similarly, with the biaryl amine groups preferably attached to the 1 or 1,6 positions of pyrene.

Examples of singlet emitters based on vinylamines and arylamines are also preferred and can be found in WO 2006/000388, WO 2006/058737, WO 2006/000389, WO 2007/065549, WO 2007/115610,US 7250532 B2,DE 102005058557 A1,CN 1583691 A,US 6251531 B1,US 2006/210830A and US 2008/0110101 A1, the entire contents of which are hereby incorporated by reference.

An example of a singlet light emitter based on stilbene and its derivatives is US 5121029.

Further preferred singlet emitters may be selected from indenofluorene-amines and indenofluorene-diamines, as disclosed in WO 2006/122630, benzoindenofluorene-amines and benzoindenofluorene-diamines, as disclosed in WO 2008/006449, dibenzoindenofluorene-amines and dibenzoindenofluorene-diamines, as disclosed in WO 2007/140847.

Further preferred singlet emitters may be selected from fluorene-based fused ring systems as disclosed in US2015333277A1, US2016099411A1, US2016204355 A1.

More preferred singlet emitters may be selected from pyrene derivatives, such as the structures disclosed in US2013175509 A1; triarylamine derivatives of pyrene, such as those containing dibenzofuran units as disclosed in CN 102232068B; other triarylamine derivatives of pyrene having a specific structure are disclosed in CN105085334A, CN105037173 a. Other materials which can be used as singlet emitters are polycyclic aromatic compounds, in particular derivatives of anthracene such as 9, 10-bis (2-naphthoanthracene), naphthalene, tetrabenzene, xanthene, phenanthrene, pyrene (such as 2,5,8, 11-tetra-t-butylperylene), indenopyrene, phenylenes such as (4, 4 '-bis (9-ethyl-3-carbazolyl) -1,1' -biphenyl), bisindenopyrene, decacyclic olefin, hexabenzobenzene, fluorene, spirobifluorene, arylpyrene (such as US 20060222886), arylene ethylene (such as US5121029, US 5130603), cyclopentadiene such as tetraphenylcyclopentadiene, rubrene, coumarin, rhodamine, quinacridone, pyrans such as 4 (dicyanomethylene) -6- (4-p-dimethylaminostyryl-2-methyl) -4H-pyran (DCM), thiopyran, bis (azinyl) boron compounds (US 2007/92753 A1), bis (azinyl) methylene compounds, carbostyryl compounds, benzoxazoles, benzooxazoles, pyrroles, and pyrroles. Some materials for singlet emitters can be found in US 20070252517 A1,US 4769292,US 6020078,US 2007/0252517 A1,US 2007/0252517 A1. The entire contents of the above listed patent documents are hereby incorporated by reference.

Examples of some suitable singlet emitters are set forth in the following table:

2. triplet emitters

Triplet emitters are also known as phosphorescent emitters. In a preferred embodiment, the triplet emitter is a metal complex of the general formula M (L) n, where M is a metal atom, L, which may be identical or different at each occurrence, is an organic ligand which is bonded or coordinately bound to the metal atom M via one or more positions, n being an integer between 1 and 6. Preferably, the triplet emitters comprise chelating ligands, i.e. ligands, which coordinate to the metal via at least two binding sites, and particularly preferably the triplet emitters comprise two or three identical or different bidentate or polydentate ligands. Chelating ligands are beneficial for improving the stability of metal complexes. In a preferred embodiment, the metal complexes useful as triplet emitters are of the form:

the metal atom M is selected from transition metal element or lanthanoid or actinoid, preferably Ir, pt, pd, au, rh, ru, os, re, cu, ag, ni, co, W or Eu, particularly preferably Ir, au, pt, W or Os.

Ar ⁴ ，Ar ⁵ Each occurrence, which may be the same or different, is a cyclic group wherein Ar ₁ Comprising at least one donor atom, i.e. an atom having a lone pair of electrons, such as nitrogen, through which the cyclic group is coordinately bound to the metal; wherein Ar is ₂ Comprising at least one carbon atom through whichThe cyclic group is attached to the metal; ar (Ar) ₁ And Ar is a group ₂ Are linked together by covalent bonds, may each carry one or more substituent groups, and may be linked together again by substituent groups; l' may be the same or different at each occurrence and is a bidentate chelating ancillary ligand, preferably a monoanionic bidentate chelating ligand; q1 may be 0,1,2 or 3, preferably 2 or 3; q2 may 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 of these organic ligands may be substituted, for example by alkyl chains or fluorine or silicon containing groups. The auxiliary ligand may preferably be selected from the group consisting of acetone acetate and picric acid.

Examples of materials and applications of triplet emitters can be found in WO200070655, WO200141512, WO200202714, WO200215645, WO2005033244, WO2005019373, US20050258742, US20070087219, US20070252517, US2008027220, WO2009146770, US20090061681, WO2009118087, WO2010015307, WO2010054731, WO2011157339, WO2012007087, WO2013107487, WO2013094620, WO2013174471, WO 2014031977,WO 2014112450,WO2014007565,WO 2014024131,Baldo et al.Nature (2000), 750,Kido et al.Appl.Phys.Lett (1994), 2124,Wrighton et al.J.Am.Chem.Soc (1974), 998. The entire contents of the above listed patent documents and literature are hereby incorporated by reference. Examples of some suitable triplet emitters are set forth in the following table:

3. Thermal activation delayed fluorescence luminescent material (TADF)

The traditional organic fluorescent material can only emit light by using 25% singlet excitons formed by electric excitation, and the internal quantum efficiency of the device is low (25% at maximum). Although phosphorescent materials enhance the system due to strong spin-orbit coupling at the center of the heavy atomThe intersystem crossing can effectively utilize singlet excitons and triplet excitons formed by electric excitation to emit light, so that the internal quantum efficiency of the device reaches 100%. However, the problems of expensive phosphorescent materials, poor material stability, serious roll-off of device efficiency and the like limit the application of the phosphorescent materials in OLED. The thermally activated delayed fluorescence luminescent material is a third generation organic luminescent material that develops subsequent to the organic fluorescent material and the organic phosphorescent material. Such materials generally have a small singlet-triplet energy level difference (ΔE _st ) Triplet excitons may be converted to singlet excitons for light emission by intersystem crossing. This makes it possible to fully utilize singlet excitons and triplet excitons formed under electric excitation. The quantum efficiency in the device can reach 100%. Meanwhile, the material has controllable structure, stable property and low price, does not need noble metal, and has wide application prospect in the field of OLED.

The TADF material needs to have a small singlet-triplet energy level difference, preferably deltaest <0.3eV, next preferably deltaest <0.2eV, and most preferably deltaest <0.1eV. In one preferred embodiment, the TADF material has a relatively small Δest, and in another preferred embodiment, the TADF material has a relatively good fluorescence quantum efficiency. Some TADF luminescent materials can be found in the following patent documents: CN103483332 (a), TW201309696 (a), TW201309778 (a), TW201350558 (a), US20120217869 (A1), WO2013133359 (A1), WO2013154064 (A1), adachi, et al adv.mate, 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.soc, 134, 2012, 14706, adachi, et al angel.chem.e.ed.2012, 2012, 51, 11311, adachi, et al chem.com, 48, 2012, 9580, adachi, et al chem.com, 48, 2013, 10385, adachi, et al adv.mate, 25, 2013, 3319, adachi, et al chem.mate, 25, 2013, 3038, adachi, et al chem.mate, 25, 2013, 3766, adachi, et al j.mate.chem.c., 1, 2013, 4599, adachi, et al j.physis.chem.a., 117, 2013, 5607, the entire contents of the above-listed patents or article documents being hereby incorporated by reference.

Examples of some suitable TADF luminescent materials are listed in the following table:

the organic electroluminescent device according to the present invention may be selected from, but is not limited to: organic Light Emitting Diodes (OLEDs), organic light emitting cells, organic light emitting field effect transistors, organic lasers, etc., with OLEDs being particularly preferred.

The cathode, anode and light extraction layer of the device structure of the organic electroluminescent device are described below, but are not limited thereto.

The anode may comprise a conductive metal or metal oxide, or a conductive polymer. The anode can easily inject holes into a Hole Injection Layer (HIL) or a Hole Transport Layer (HTL) or a 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 emitter in the light emitting layer or of the p-type semiconductor material as HIL or HTL or Electron Blocking Layer (EBL) is less than 0.5eV, preferably less than 0.3eV, most preferably less than 0.2eV. 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), and the like. Other suitable anode materials are known and can be readily selected for use by one of ordinary skill in the art. The anode material may 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), and the like. In certain embodiments, the anode is patterned. Patterned ITO conductive substrates are commercially available and can be used to prepare devices according to the present invention.

The cathode may comprise a conductive metal or metal oxide. The cathode can easily inject electrons into the EIL or ETL or directly into the hairIn the optical layer. In one embodiment, the absolute value of the difference between the work function of the cathode and the LUMO or conduction band level of the light-emitting body in the light-emitting layer or of the n-type semiconductor material as an Electron Injection Layer (EIL) or Electron Transport Layer (ETL) or Hole Blocking Layer (HBL) is less than 0.5eV, preferably less than 0.3eV, and most preferably less than 0.2eV. In principle, all materials which can be used as cathode of an OLED are possible as cathode materials for the device according to the invention. Examples of cathode materials include, but are not limited to: al, au, ag, ca, ba, mg, liF/Al, mgAg alloy and BaF ₂ /Al, cu, fe, co, ni, mn, pd, pt, ITO, etc. The cathode material may 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), and the like.

The light extraction layer needs to have a proper energy level structure, has stronger absorption in a region with the wavelength smaller than 400nm, and has weak or near zero absorption when the visible light with the wavelength larger than 400nm, so that the damage to the internal materials of the device caused by the irradiation of high-energy light in the subsequent process is avoided. Meanwhile, the light extraction layer has a higher refractive index, can be used for beneficially guiding out the emission of visible light, and improves the luminous efficiency of the organic electroluminescent device. When the reflectance of the interface between the light extraction layer and the adjacent electrode is large, the influence of light interference is large, and therefore, the refractive index of the material constituting the light extraction layer is preferably larger than that of the adjacent electrode, and the refractive index is preferably 1.50 or more, more preferably 1.70 or more, and particularly preferably 1.80 or more at 630 nm.

In some more preferred embodiments, the organic electroluminescent device according to the present invention has a thickness of the organic compound of the light extraction layer of generally 10nm to 200nm, preferably 20nm to 150nm, more preferably 30nm to 100nm, and most preferably 40nm to 90nm.

In one embodiment, as shown in fig. 1, the organic electroluminescent device includes an anode 2, an organic functional layer 3, a cathode 4, and a light extraction layer 5 sequentially stacked on a substrate 1, wherein the organic functional layer 3 includes a Hole Injection Layer (HIL) 3a, a Hole Transport Layer (HTL) 3b, a light emitting layer 3c, an Electron Transport Layer (ETL) 3d, an Electron Injection Layer (EIL) 3e sequentially stacked, the Hole Injection Layer (HIL) 3a layer being adjacent to the anode 2, and the Electron Injection Layer (EIL) 3e being adjacent to the cathode 4.

The invention also relates to the use of the electroluminescent device according to the invention in various electronic devices, including, but not limited to, display devices, lighting devices, light sources, sensors, etc.

The invention further relates to a compound selected from the structures shown in the general formula (5):

wherein:

n≥2；

A is independently selected from structural formula (6) at each occurrence

W is independently selected from O or S for each occurrence; preferably, W is selected from S.

R ₁ independently at each occurrence selected from the group consisting of hydrogen, D, straight chain alkyl having 1 to 20C atoms, alkoxy having 1 to 20C atoms, thioalkoxy having 1 to 20C atoms, branched alkyl having 3 to 20C atoms, cyclic alkyl having 3 to 20C atoms, alkoxy having 3 to 20C atoms, thioalkoxy having 3 to 20C atoms, silyl, keto having 1 to 20C atoms, alkoxycarbonyl having 2 to 20C atoms, aryloxycarbonyl having 7 to 20C atoms, cyanoCarbamoyl, haloformyl, formyl, isocyano, isocyanate, thiocyanate, isothiocyanate, hydroxy, nitro, CF ₃ Cl, br, F, a crosslinkable group, a substituted or unsubstituted aromatic group having from 5 to 60 ring atoms, a substituted or unsubstituted heteroaromatic group having from 5 to 60 ring atoms, a substituted or unsubstituted aryloxy group having from 5 to 60 ring atoms, or a substituted or unsubstituted heteroaryloxy group having from 5 to 60 ring atoms, or a combination of these systems;

Q has the meaning as described above.

In a preferred embodiment, Q is selected from aromatic or heteroaromatic groups having 5 to 30 ring atoms.

In a preferred embodiment, Q is selected from any one of the following groups:

in a preferred embodiment, Q is selected from any one of the following groups:

specifically, the structure of the general formula (5) may be selected from any one of compounds of the general formulae (7-1) to (7-5):

Ar ₂ w has the meaning given above.

In certain preferred embodiments, ar ₂ Can be selected from furan, oxadiazole, benzene, pyridine and naphthalene.

In certain preferred embodiments, R ₄ ，R ₅ Can be selected from

Specifically, the compound according to the present invention is selected from any one of the structural formulas (G-90) - (G-112) as described above, but is not limited thereto.

The compound shown in the general formula (5) can be applied to not only the light extraction layer of the organic electroluminescent device, but also other organic functional layers, such as: an electron injection layer, an electron transport layer, a hole injection layer, a hole transport layer, and a light emitting layer. It is an object of the present invention to provide a material solution for an evaporated OLED.

In certain embodiments, the compounds according to the invention have a molecular weight of 1200g/mol or less, preferably 1100g/mol or less, very preferably 1000g/mol or less, more preferably 950g/mol or less, most preferably 900g/mol or less.

It is another object of the invention to provide a material solution for printed OLEDs.

In certain embodiments, the compounds according to the invention have a molecular weight of 800g/mol or more, preferably 900g/mol or more, very preferably 1000g/mol or more, more preferably 1100g/mol or more, most preferably 1200g/mol or more.

In other embodiments, the compounds according to the invention have a solubility in toluene of 2mg/ml or more, preferably 3mg/ml or more, more preferably 4mg/ml or more, most preferably 5mg/ml or more at 25 ℃.

The invention also relates to a composition comprising at least one compound according to formula (5) and at least one organic solvent; the at least one organic solvent is selected from aromatic or heteroaromatic, ester, aromatic ketone or aromatic ether, aliphatic ketone or aliphatic ether, alicyclic or olefinic compound, borate or phosphate compound, or mixture of two or more solvents.

The invention further relates to an organic electronic device comprising at least one compound as described above. The organic electronic device according to the present invention may be selected from, but not limited to, organic Light Emitting Diodes (OLEDs), organic photovoltaic cells, organic light emitting cells, organic field effect transistors, organic light emitting field effect transistors, organic lasers, organic spintronic devices, organic sensors, organic plasmon emitting diodes, etc., with OLEDs being particularly preferred.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

The present invention will be illustrated by the following specific examples, but the present invention is not limited to the following examples. It is to be understood that the appended claims outline the scope of the invention, and those skilled in the art, guided by the inventive concepts herein provided, will appreciate that certain modifications to the various embodiments of the invention will be covered by the scope of the appended claims.

The structure of the synthetic examples is as follows:

synthesis of Compound C-1:

i-1 (4 g,12.3 mmol), I-2 (9.6 g,26 mmol), potassium carbonate (8.5 g,61 mmol), tetrakis (triphenylphosphine) palladium (0.43 g,0.37 mmol) were weighed into a 250mL double-neck flask, 150mL of a mixed solvent of toluene and water was added, nitrogen was purged three times, and the temperature was raised to 90℃and stirred overnight. After the reaction solution was cooled to room temperature, water was added thereto, extraction was performed with ethyl acetate, the organic phase was washed with brine, dried over sodium sulfate, and the organic solvent was distilled off under reduced pressure, whereby 6.6g of the objective product was obtained by column chromatography on silica gel with a yield of 82%.

I-3 (6.6 g,10.1 mmol), I-4 (3 g,11 mmol), dipalladium tris (dibenzylideneacetone) (275 mg,0.3 mmol), sodium tert-butoxide (0.96 g,10.1 mmol), and tri-tert-butylphosphine were weighed into a 250mL two-necked flask, 100mL of toluene was added, nitrogen was purged three times, and the temperature was raised to 100℃and stirred overnight. After the reaction solution is cooled to room temperature, water is added, an organic phase is separated, ethyl acetate is used for extraction, the organic phases are combined, the organic solvent is removed by reduced pressure distillation, and the target product is obtained by silica gel sample column chromatography, wherein the yield is 75%. m/z=844.5

Synthesis of Compound C-2:

i-6 (1.5 g,4.6 mmol), I-5 (4.2 g,9.5 mmol), potassium carbonate (1.6 g,11.5 mmol), tetrakis (triphenylphosphine) palladium (0.16 g,0.14 mmol) were weighed into a 250mL two-necked flask, 80mL of a mixed solvent of toluene and water was added, nitrogen was purged three times, the temperature was raised to 90℃and stirring was continued overnight. After the reaction solution is cooled to room temperature, water is added, ethyl acetate is used for extraction, an organic phase is washed by brine, dried by sodium sulfate, the organic solvent is removed by reduced pressure distillation, and the target product C-2 is obtained by silica gel sample column chromatography with the total yield of 2.2g and 60 percent. m/z= 792.8

Synthesis of Compound C-3:

i-7 (5 g,15.7 mmol) was weighed and dissolved in 70mL of methylene chloride, the reaction solution was cooled to 0℃and N-bromosuccinimide (5.6 g) was added. After the reaction is finished, adding water, separating out an organic phase, extracting with dichloromethane, combining the organic phases, distilling under reduced pressure to remove the organic solvent, and performing silica gel sample mixing column chromatography to obtain 5.8g of a target product with the yield of 78%.

The synthesis step of the compound C-3 is similar to that of I-3, the target product is obtained by silica gel sample column chromatography, the yield is 72%, the ultraviolet-visible absorption spectrum of the compound C-3 in methylene dichloride solution is shown in figure 2, and the refractive index and extinction coefficient are shown in figure 3. m/z= 800.4

Synthesis of Compound C-4:

The synthesis step of the compound I-10 is similar to that of I-3, and the target product is obtained by silica gel sample mixing column chromatography, 4.2g is obtained, and the yield is 65%.

The synthesis step of the compound I-11 is similar to that of I-8, and the target product is obtained by silica gel sample mixing column chromatography, 4.15g is obtained, and the yield is 69%.

The synthesis step of the compound C-4 is similar to that of I-3, and the target product is obtained by silica gel sample mixing column chromatography, wherein the yield is 86 percent, and 5.8 g. m/z=841.5

Synthesis of Compound C-5:

the synthesis step of the compound I-13 is similar to that of I-3, and the target product is obtained by silica gel sample mixing column chromatography, and the yield is 79 percent.

The synthesis step of the compound I-14 is similar to that of I-8, and the target product is obtained by silica gel sample mixing column chromatography, and the yield is 65%.

The synthesis step of the compound C-5 is similar to that of I-3, and the target product is obtained by silica gel sample mixing column chromatography, wherein the yield is 82 percent. m/z= 827.1

Synthesis of Compound C-6:

the synthesis step of the compound C-6 is similar to that of I-3, and the target product is obtained by silica gel sample mixing column chromatography, 2.6g is obtained, and the yield is 55%. m/z= 818.6

Synthesis of Compound C-7:

the synthesis step of the compound I-19 is similar to that of I-8, and the target product is obtained by silica gel sample mixing column chromatography, wherein the yield is 87 percent.

The synthesis step of the compound C-7 is similar to that of I-3, and the target product is obtained by silica gel sample mixing column chromatography, wherein the yield is 54 percent. m/z=800.6

Synthesis of Compound C-8:

the synthesis step of the compound C-8 is similar to that of I-3, and the target product is obtained by silica gel sample mixing column chromatography, wherein the yield is 58%. m/z=791.6

Synthesis of Compound C-9:

the synthesis step of the compound C-9 is similar to that of I-3, and the target product is obtained by silica gel sample mixing column chromatography, wherein the yield is 60 percent, and 1.2 g. m/z= 951.1

Synthesis of Compound C-10:

the synthesis procedure for compound I-20 was similar to that for I-3, and the synthesis procedure for compound I-21 was similar to that for I-8, with a total yield of 51% for both parts, yielding 5g.

The synthesis step of the compound C-10 is similar to that of I-3, and the target product is obtained by silica gel sample mixing column chromatography, and the yield is 78%. m/z= 830.4

Synthesis of Compound C-11:

the synthesis step of the compound I-22 is similar to that of I-3, and the target product is obtained by silica gel sample mixing column chromatography, wherein the yield is 46%.

The synthesis step of the compound C-11 is similar to that of I-3, and the target product is obtained by silica gel sample mixing column chromatography, and the yield is 65%. Energy structure of m/z= 889.7 organic compound

The energy level of the organic material can be obtained by quantum computation, for example by means of a Gaussian09W (Gaussian inc.) using a TD-DFT (time-dependent density functional theory), and a specific simulation method can be seen in WO2011141110. The molecular geometry is first optimized by the semi-empirical method "group State/DFT/Default Spin/B3LYP/6-31G (d)" (Charge 0/Spin single), and then the energy structure of the organic molecule is calculated by the TD-DFT (time Density functional theory) method as "TD-SCF/DFT/Default Spin/B3PW91" and the basis set "6-31G (d)" (Charge 0/Spin single).

The compound is evaporated on monocrystalline silicon in a vacuum evaporation mode to form a 50nm film, the monocrystalline silicon is placed on an ellipsometer (ES-01) sample stage, the incident angle is 70 degrees, the test is in an atmospheric environment, and the test result of the extinction coefficient (k) and the refractive index (n) of the compound is obtained by the ellipsometer.

The results are shown in Table 1:

TABLE 1

The compound of the invention has weak absorption in the visible light band and higher absorption in the ultraviolet band, can resist the damage of external high-energy light to the inside of the device, and reduces the influence on visible light. Higher refractive index ensures better light extraction.

Preparation and characterization of OLED devices

The following describes in detail the preparation process of the OLED device by using the specific embodiment, and the OLED device has the following structure: ITO/Ag/ITO (anode)/HATCN/SFNFB/m-CP Ir (p-ppy) ₃ /NaTzF ₂ Ag/light extraction layer, the preparation steps are as follows:

the ITO conductive glass anode layer was cleaned, then ultrasonically cleaned with deionized water, acetone, isopropanol for 15 minutes, and then treated in a plasma cleaner for 5 minutes to increase the work function of the electrode. Evaporating cavity injection layer material HATCN with thickness of 5nm by vacuum evaporation on ITO anode layerAnd/s. On the hole injection layer, a hole transport material SFNFB was vapor deposited by vacuum vapor deposition to a thickness of 80nm. Evaporating a light-emitting layer on the hole transport layer, using m-CP as a host material, ir (p-ppy) ₃ Ir (p-ppy) as doping material ₃ And m-CP is 1:9 by mass and 30nm thick. Evaporating electron transport material NaTzF on the luminescent layer by vacuum evaporation ₂ The thickness was 30nm.Above the electron transport layer, an electron injection layer LiF was vacuum evaporated to a thickness of 1nm, which was an electron injection layer 7. And on the electron injection layer, vacuum evaporating a cathode Mg-Ag layer, wherein the doping ratio of Mg to Ag is 9:1, and the thickness is 15nm. On the cathode layer, the light extraction layer compound C-1 was deposited by vacuum evaporation to a thickness of 60nm.

Device example 2: the light extraction layer compound of the organic electroluminescent device becomes C-3.

Device example 3: the light extraction layer compound of the organic electroluminescent device becomes C-6.

Device example 4: the light extraction layer compound of the organic electroluminescent device becomes C-7.

Device example 5: the light extraction layer compound of the organic electroluminescent device becomes C-8.

Device example 6: the light extraction layer compound of the organic electroluminescent device becomes C-2.

Device example 7: the light extraction layer compound of the organic electroluminescent device becomes C-4.

Device example 8: the light extraction layer compound of the organic electroluminescent device becomes C-5.

Device example 9: the light extraction layer compound of the organic electroluminescent device becomes C-9.

Device example 10: the light extraction layer compound of the organic electroluminescent device becomes C-10.

Device example 11: the light extraction layer compound of the organic electroluminescent device becomes C-11.

Device comparative example 1: the light extraction layer compound of the organic electroluminescent device becomes CBP.

Device comparative example 2: the light extraction layer compound of the organic electroluminescent device becomes CT-1.

Device comparative example 3: the light extraction layer compound of the organic electroluminescent device becomes CT-2.

The structure of the compound involved in the device is as follows:

TABLE 2

Numbering device	Light extraction layer compound	Luminous efficiency
			1	C-1	1.22
2	C-3	1.24
			3	C-6	1.10
4	C-7	1.20
			5	C-8	1.15
6	C-2	1.13
			7	C-4	1.25
8	C-5	1.07
			9	C-9	1.05
10	C-10	1.16
			11	C-11	1.15
12	CBP	1.01
			13	CT-1	1.03
14	CT-2	1.0

The luminous efficiency is a relative value in table 2. From table 2, it can be seen that the relative values of the luminous efficiency of the device, the compound of the present invention can effectively improve the luminous efficiency of the organic electroluminescent device as a light extraction layer.

The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.

Claims

1. An organic electroluminescent device comprising two electrodes, one or more organic functional layers disposed between the two electrodes, and a light extraction layer disposed over an electrode, characterized in that: the light extraction layer material comprises a compound represented by the general formula (1):

wherein:

q is selected from one or a combination of the following groups:

wherein: z is independently selected from CR when multiple occurrences occur ₄ Or N; w is independently selected from CR when multiple occurrences occur ₅ R ₆ 、NR ₅ O, S, C =o or Se; * Represents the site of attachment to A;

n≥2；

each occurrence of A is independently selected from one or a combination of the following groups:

wherein: w is independently selected from CR when multiple occurrences occur ₅ R ₆ 、NR ₅ O, S, C =o or Se; * Represents the site of attachment to Q;

x is selected from

The dotted line indicates that X is linked to benzene;

R ₂ -R ₆ independently at each occurrence selected from the group consisting of hydrogen, D, straight chain alkyl having 1 to 20C atoms, alkoxy having 1 to 20C atoms, thioalkoxy having 1 to 20C atoms, branched alkyl having 3 to 20C atoms, cyclic alkyl having 3 to 20C atoms, silyl, keto having 1 to 20C atoms, alkoxycarbonyl having 2 to 20C atoms, aryloxycarbonyl having 7 to 20C atoms, cyano, carbamoyl, haloformyl, formyl, isocyano, isocyanate, thiocyanate, isothiocyanate, hydroxyl, nitro, CF ₃ Cl, br, F, a substituted or unsubstituted aromatic group having from 5 to 60 ring atoms, a substituted or unsubstituted heteroaromatic group having from 5 to 60 ring atoms, a substituted or unsubstituted aryloxy group having from 5 to 60 ring atoms, or a substituted or unsubstituted heteroaryloxy group having from 5 to 60 ring atoms, or a combination of these systems.

2. The organic electroluminescent device of claim 1, wherein: the general formula (1) is selected from the general formula (3-1):

wherein:

x is selected from

3. The organic electroluminescent device according to claim 2, wherein: the general formula (1) is selected from any one of general formulas (4-5) - (4-6):

wherein: z, W meaningThe same claim 1; r is R ₄ Each occurrence is independently selected from the group consisting of hydrogen, D, straight chain alkyl having 1 to 20C atoms, alkoxy having 1 to 20C atoms, thioalkoxy having 1 to 20C atoms, branched alkyl having 3 to 20C atoms, cyclic alkyl having 3 to 20C atoms, silyl, keto having 1 to 20C atoms, alkoxycarbonyl having 2 to 20C atoms, aryloxycarbonyl having 7 to 20C atoms, cyano, carbamoyl, haloformyl, formyl, isocyano, isocyanate, thiocyanate, isothiocyanate, hydroxyl, nitro, CF ₃ Cl, br, F, a substituted or unsubstituted aromatic group having from 5 to 60 ring atoms, a substituted or unsubstituted heteroaromatic group having from 5 to 60 ring atoms, a substituted or unsubstituted aryloxy group having from 5 to 60 ring atoms, or a substituted or unsubstituted heteroaryloxy group having from 5 to 60 ring atoms, or a combination of these systems.

4. The organic electroluminescent device of claim 3, wherein the R ₄ Selected from alkyl groups having 1 to 6C atoms, CN or any of the following groups:

e is independently selected from CR when multiple occurrences occur ₇ Or N; y is independently selected from CR when multiple occurrences occur ₇ R ₈ 、NR ₉ O or S;

5. The organic electroluminescent device of claim 1, wherein: the refractive index of the light extraction layer material at the wavelength of 630nm is greater than 1.7; and/or

The singlet energy (S1) of the light extraction layer material is greater than 2.7eV.

6. The organic electroluminescent device of claim 1, wherein: the organic electroluminescent device is an organic light emitting diode, wherein the light extraction layer is positioned on the surface of the cathode, which is far away from the organic functional layer.

7. A compound, characterized in that: selected from the structures described by general formula (5):

wherein:

q is selected from one or a combination of the following groups:

n≥2；

x is selected fromThe dotted line indicates that X is linked to benzene;

R ₂ -R ₆ independently at each occurrence selected from the group consisting of hydrogen, D, straight chain alkyl having 1 to 20C atoms, alkoxy having 1 to 20C atoms, thioalkoxy having 1 to 20C atoms, branched alkyl having 3 to 20C atoms, cyclic alkyl having 3 to 20C atoms, silyl, keto having 1 to 20C atoms, alkoxycarbonyl having 2 to 20C atoms, aryloxycarbonyl having 7 to 20C atoms, cyano, carbamoyl, haloformyl, formyl, isocyano, isocyanate, thiocyanate, isothiocyanate, hydroxyl, nitro, CF ₃ Cl, br, F, a substituted or unsubstituted aromatic group having from 5 to 60 ring atoms, a substituted or unsubstituted heteroaromatic group having from 5 to 60 ring atoms, a substituted or unsubstituted aryloxy group having from 5 to 60 ring atoms, or a substituted or unsubstituted heteroaryloxy group having from 5 to 60 ring atoms, or a combination of these systems;

* Representing the ligation site.

8. A composition comprising at least one compound of claim 7 and at least one organic solvent.

9. Use of a compound according to claim 7 or a composition according to claim 8 for the preparation of a light extraction layer.