CN113943280A

CN113943280A - Compound containing benzo-heterocycle structure, electroluminescent device, and display device

Info

Publication number: CN113943280A
Application number: CN202111221736.8A
Authority: CN
Inventors: 陈磊; 梁丙炎; 陈雪芹; 张东旭; 王丹
Original assignee: BOE Technology Group Co Ltd
Current assignee: BOE Technology Group Co Ltd
Priority date: 2021-10-20
Filing date: 2021-10-20
Publication date: 2022-01-18

Abstract

A compound containing a benzo-heterocycle structure, an electroluminescent device and a display device are disclosed, wherein the structural general formula of the compound containing the benzo-heterocycle structure is shown as a formula I; wherein each group and substituent has the same meaning as in the specification. The compound containing the benzo heterocyclic structure provided by the embodiment of the disclosure has a high refractive index, and can be used as a light extraction material to improve the luminous efficiency of a device; in addition, the compound containing the benzo heterocyclic structure provided by the embodiment of the disclosure has strong absorption of ultraviolet light, but does not absorb light of the device itself, and when the compound is used as a light extraction material, the compound can effectively protect the device from being damaged by ultraviolet light on internal devices; in addition, the compound containing the benzo heterocyclic structure provided by the embodiment of the disclosure has good thermal stability, and has good stability when a light extraction layer is formed by adopting an evaporation process, so that the problem of shortened service life of a device caused by impurities generated in evaporation due to unstable materials can be avoided.

Description

Compound containing benzo-heterocycle structure, electroluminescent device, and display device

Technical Field

The disclosed embodiments relate to, but are not limited to, the technical field of display, and in particular, to a compound containing a benzo-heterocycle structure, an electroluminescent device and a display device.

Background

In recent years, Organic Light Emitting Devices (OLEDs) have been receiving more attention as a new type of flat panel display. The display has the characteristics of active light emission, high brightness, high resolution, wide viewing angle, high response speed, low energy consumption, flexibility and the like, so that the display becomes a popular mainstream display product in the market at present. With the continuous development of products, the resolution requirement of customers on the products is higher and higher, and the power consumption requirement value is lower and lower. Therefore, there is a need to develop a high efficiency, low voltage, long lifetime device.

Currently, most OLED devices adopt a top-emitting device structure. The top-emitting device structure adopts a reflective anode and a transparent cathode to enhance the light extraction efficiency through the microcavity effect. In this device, a very important functional Layer is a light extraction Layer (also called a Capping Layer, CPL). The light extraction layer is generally provided with a higher refractive index and is arranged on the upper layer of the cathode to form the matching of the high refractive index and the low refractive index, so that a better light extraction effect is realized.

However, the refractive index of the CPL material is generally about 2.0@460nm, and the effect of improving the light extraction and the device efficiency is still limited. Moreover, the current CPL material has small ultraviolet absorption to the external environment, and it is difficult to avoid the device from being damaged by the ultraviolet light.

Disclosure of Invention

The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the present application.

The embodiment of the present disclosure provides a compound containing a benzo-heterocycle structure, where the structural general formula of the compound containing a benzo-heterocycle structure is:

wherein at least one of Z1, Z2 and Z3 is N, and the others are C (H);

r1 and R2 are each independently any one of substituted or unsubstituted Ar2, substituted or unsubstituted group of formula II, substituted or unsubstituted group of formula III, and substituted or unsubstituted group of formula IV, and R1 and R2 are not both Ar 2; here, substituted Ar2, substituted group of formula II, substituted group of formula III, substituted group of formula IV means substituted with Ar 3;

x1 and X2 are respectively and independently any one of C (H), CR3 and N, and Y is any one of O, S, N (H), NR4 and CR5R 6; here, R3, R4, R5, R6 are each independently hydrogen, deuterium, halogen, nitro, nitrile group, substituted or unsubstituted C1 to C60 alkyl group, substituted or unsubstituted C3 to C30 cycloalkyl group, substituted or unsubstituted C2 to C30 alkenyl group, substituted or unsubstituted C1 to C30 alkoxy group, substituted or unsubstituted C1 to C30 thioether group, substituted or unsubstituted C6 to C60 aryl group, substituted or unsubstituted C5 to C60 heteroaryl group; here, substituted C1 to C60 alkyl, substituted C3 to C30 cycloalkyl, substituted C2 to C30 alkenyl, substituted C1 to C30 alkoxy, substituted C1 to C30 thioether, substituted C6 to C60 aryl, substituted C5 to C60 heteroaryl means substituted with one or more of the following groups: hydrogen, deuterium, halogen, nitro, nitrile group, alkyl group of C1 to C60, cycloalkyl group of C3 to C30, alkenyl group of C2 to C30, alkoxy group of C1 to C30, thioether group of C1 to C30, aryl group of C6 to C60, heteroaryl group of C5 to C60;

ar1, Ar2, Ar3 are each independently any one of hydrogen, a nitrile group, an alkyl group of C2 to C30, a cycloalkyl group of C3 to C30, an aryl group of C6 to C60 substituted by a substituent R7, an aryl group of unsubstituted C6 to C60, a heteroaryl group of C5 to C60 substituted by a substituent R8, and a heteroaryl group of unsubstituted C5 to C60, and Ar2 is not hydrogen, a nitrile group, an alkyl group of C2 to C30, Ar3 is not hydrogen; here, the substituents R7, R8 are each independently any one or more of a nitrile group, an alkyl group of C2 to C30, an aryl group of unsubstituted C6 to C60, an aryl group of C6 to C60 substituted with a substituent R9, a heteroaryl group of unsubstituted C5 to C60, and a heteroaryl group of C5 to C60 substituted with a substituent R10; here, the substituents R9, R10 are each independently any one or more of a nitrile group, an aryl group of C6 to C60;

l1, L2, L3 are each independently any one of a single bond, a substituted or unsubstituted arylene group of C6 to C60, a substituted or unsubstituted heteroarylene group of C2 to C60, where the substituted arylene group of C6 to C60, the substituted heteroarylene group of C2 to C60 are substituted with one or more of the following groups: deuterium, halogen, nitro, nitrile group, aryl of C6 to C60, heteroaryl of C2 to C60;

m, n are each independently 0,1 or 2, and m + n is 2.

Embodiments of the present disclosure also provide an electroluminescent device including a light extraction layer, and a material of the light extraction layer may include a compound including a benzo-heterocycle structure as described above.

The embodiment of the present disclosure also provides a display device including the electroluminescent device as described above.

Additional features and advantages of the disclosure will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the disclosure. Other advantages of the disclosure may be realized and attained by the instrumentalities and combinations particularly pointed out in the specification and the drawings.

Drawings

The accompanying drawings are included to provide an understanding of the disclosed embodiments and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the examples serve to explain the principles of the disclosure and not to limit the disclosure.

Fig. 1 is a schematic structural view of an electroluminescent device according to an exemplary embodiment of the present disclosure;

FIG. 2 is a graph of refractive index change at different wavelengths for compound 1' of an exemplary embodiment of the present disclosure versus the compound of comparative example 1;

fig. 3 is a graph of the change in absorption coefficient at different wavelengths for compound 1' of an exemplary example of the present disclosure and the compound of comparative example 1.

The reference symbols in the drawings have the following meanings:

100-a cathode; 200-a hole injection layer; 300-hole transport layer; 400-an electron blocking layer; 500-a light emitting layer; 600-a hole blocking layer; 700-electron transport layer; 800-electron injection layer; 900-cathode; 1000-light extraction layer.

Detailed Description

The embodiments herein may be embodied in many different forms. Those skilled in the art can readily appreciate the fact that the present implementations and teachings can be modified into a variety of forms without departing from the spirit and scope of the present disclosure. Therefore, the present disclosure should not be construed as being limited to the contents described in the following embodiments. The embodiments and features of the embodiments in the present disclosure may be arbitrarily combined with each other without conflict.

In the drawings, the size of constituent elements, the thickness of layers, or regions may be exaggerated for clarity. Thus, any one implementation of the present disclosure is not necessarily limited to the dimensions shown in the figures, and the shapes and sizes of the components in the figures are not intended to reflect actual proportions. Further, the drawings schematically show ideal examples, and any one implementation of the present disclosure is not limited to the shapes, numerical values, or the like shown in the drawings.

wherein at least one of Z1, Z2 and Z3 is N, and the others are C (H);

x1 and X2 are respectively and independently any one of C (H), CR3 and N, and Y is any one of O, S, N (H), NR4 and CR5R 6; here, R3, R4, R5, R6 are each independently hydrogen, deuterium, halogen, nitro, a nitrile group (or cyano group), a substituted or unsubstituted C1 to C60 alkyl group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C2 to C30 alkenyl group, a substituted or unsubstituted C1 to C30 alkoxy group, a substituted or unsubstituted C1 to C30 thioether group, a substituted or unsubstituted C6 to C60 aryl group, a substituted or unsubstituted C5 to C60 heteroaryl group; here, substituted C1 to C60 alkyl, substituted C3 to C30 cycloalkyl, substituted C2 to C30 alkenyl, substituted C1 to C30 alkoxy, substituted C1 to C30 thioether, substituted C6 to C60 aryl, substituted C5 to C60 heteroaryl means substituted with one or more of the following groups: hydrogen, deuterium, halogen, nitro, nitrile group, alkyl group of C1 to C60, cycloalkyl group of C3 to C30, alkenyl group of C2 to C30, alkoxy group of C1 to C30, thioether group of C1 to C30, aryl group of C6 to C60, heteroaryl group of C5 to C60;

m, n are each independently 0,1 or 2, and m + n is 2.

In embodiments of the present disclosure, the aryl group includes, but is not limited to, phenyl, naphthyl, anthracenyl, acenaphthenyl, indenyl, phenanthryl, azulenyl, pyrenyl, fluorenyl, perylenyl, spirofluorenyl, spirobifluorenyl,

phenyl, benzophenanthryl, benzanthryl, fluoranthryl, picene, tetracene, and indacenyl.

The term "hetero" as used in heteroaryl means that at least one carbon atom in the aromatic ring is substituted with a heteroatom selected from any one or more of a nitrogen atom (N), an oxygen atom (O) and a sulfur atom (S).

In embodiments of the present disclosure, the heteroaryl group includes, but is not limited to, benzoxazolyl, benzothiazolyl, indolyl, benzimidazolyl, pyrrolyl, pyridinyl, pyrimidinyl, pyrazinyl, pyridazinyl, triazinyl, tetrazinyl, imidazolyl, pyrazolyl, carbazolyl, thienyl, thiazolyl, benzocarbazolyl, dibenzocarbazolyl, indolocarbazolyl, indenocarbazolyl, quinolinyl, isoquinolinyl, phthalazinyl (phthalazinyl), quinoxalinyl (quinoxalinyl), cinnolinyl (cinnolinyl), quinazolinyl, phthalazinyl, benzoquinolinyl, benzisoquinolinyl, benzoquinazolinyl, benzoquinoxalinyl, acridinyl, phenanthrolinyl, furanyl, pyranyl, oxazinyl, oxazolyl, oxadiazolyl (oxadiazolyl), triazolyl, dioxinyl (dioxanyl), benzofuranyl, dibenzofuranyl, thiopyranyl, thiazinyl, thiophenyl and N-substituted spirofluorenyl.

The compound containing the benzo heterocyclic structure provided by the embodiment of the disclosure has a high refractive index, and can be used as a light extraction material to improve the luminous efficiency of a device; in addition, the compound containing the benzo heterocyclic structure provided by the embodiment of the disclosure has strong absorption of ultraviolet light, but does not absorb light of the device itself, and when the compound is used as a light extraction material, the compound can effectively protect the device from being damaged by ultraviolet light on internal devices; in addition, the compound containing the benzo heterocyclic structure provided by the embodiment of the disclosure has good thermal stability, and has good stability when a light extraction layer is formed by adopting an evaporation process, so that the problem of shortened service life of a device caused by impurities generated in evaporation due to unstable materials can be avoided.

In an exemplary embodiment, Z1, Z2, Z3 may all be N; alternatively, two of Z1, Z2, Z3 may be N, and the other is c (h).

In exemplary embodiments, R1, R2 may each independently be any one of the following groups:

in exemplary embodiments, L1, L2, L3 may each independently be any one of a single bond, phenylene, naphthylene.

In the exemplary embodiment, it is contemplated that,

r1 may be a substituted or unsubstituted group of formula II, R2 may be Ar 2; or

R1 and R2 may each independently be any of a substituted or unsubstituted group represented by formula III and a substituted or unsubstituted group represented by formula IV.

In an exemplary embodiment, R1 is a substituted or unsubstituted group of formula II, where substituted group of formula II is substituted with Ar 3; r2 is substituted or unsubstituted Ar 2; m is 1, n is 1;

at least one of Z1, Z2, Z3 may be N, the others are c (h);

x1 and X2 may be each independently any one of c (h), CR3, and N; here, R3 may be hydrogen, deuterium, halogen, nitro, nitrile, substituted or unsubstituted C1 to C60 alkyl, substituted or unsubstituted C2 to C30 alkenyl, substituted or unsubstituted C1 to C30 alkoxy, substituted or unsubstituted C1 to C30 thioether, substituted or unsubstituted C6 to C60 aryl, substituted or unsubstituted C5 to C60 heteroaryl; here, substituted C1 to C60 alkyl, substituted C2 to C30 alkenyl, substituted C1 to C30 alkoxy, substituted C1 to C30 thioether, substituted C6 to C60 aryl, substituted C5 to C60 heteroaryl means substituted with one or more of the following groups: hydrogen, deuterium, halogen, nitro, nitrile group, alkyl group of C1 to C60, alkenyl group of C2 to C30, alkoxy group of C1 to C30, thioether group of C1 to C30, aryl group of C6 to C60, heteroaryl group of C5 to C60;

ar1, Ar2, Ar3 may each independently be any one of an aryl group of C6 to C60 substituted with a substituent R7, an aryl group of unsubstituted C6 to C60, a heteroaryl group of C5 to C60 substituted with a substituent R8, and a heteroaryl group of unsubstituted C5 to C60; here, the substituents R7, R8 are each independently any one or more of an alkyl group of C2 to C30, an aryl group of unsubstituted C6 to C60, an aryl group of C6 to C60 substituted with a substituent R9, a heteroaryl group of unsubstituted C5 to C60, and a heteroaryl group of C5 to C60 substituted with a substituent R10; here, the substituents R9, R10 are each independently any one or more of aryl groups of C6 to C60;

l1, L2, L3 may each independently be any one of a single bond, a substituted or unsubstituted arylene group of C6 to C60, a substituted or unsubstituted heteroarylene group of C2 to C60, where the substituted arylene group of C6 to C60, the substituted heteroarylene group of C2 to C60 are meant to be substituted with one or more of the following groups: deuterium, halogen, nitro, nitrile group, aryl of C6-C60, heteroaryl of C2-C60.

In exemplary embodiments, X1, X2 may both be N; alternatively, one of X1 and X2 may be N, and the other may be c (h).

In an exemplary embodiment, Z1, Z2, Z3 may all be N; alternatively, Z1, Z3 may be N, Z2 is c (h); alternatively, Z1, Z2 may be N, and Z3 is c (h).

In an exemplary embodiment, R1, R2 may each independently be any of a substituted or unsubstituted group of formula III, a substituted or unsubstituted group of formula IV, where substituted group of formula III, substituted group of formula IV means substituted with Ar 3;

z2, Z3 may be N, Z1 may be c (h);

y can be any one of O, S, N (H), NR4 and CR5R 6; here, R4, R5, R6 may each independently be hydrogen, deuterium, halogen, nitro, a nitrile group, a substituted or unsubstituted alkyl group of C1 to C60, a substituted or unsubstituted cycloalkyl group of C3 to C30, a substituted or unsubstituted aryl group of C6 to C60, a substituted or unsubstituted heteroaryl group of C5 to C60; here, substituted C1 to C60 alkyl, substituted C3 to C30 cycloalkyl, substituted C6 to C60 aryl, substituted C5 to C60 heteroaryl means substituted with one or more of the following groups: hydrogen, deuterium, halogen, nitro, nitrile group, alkyl group of C1 to C60, cycloalkyl group of C3 to C30, aryl group of C6 to C60, heteroaryl group of C5 to C60;

ar1, Ar3 may each independently be any one of hydrogen, a nitrile group, an alkyl group of C2 to C30, a cycloalkyl group of C3 to C30, an aryl group of C6 to C60 substituted with a substituent R7, an aryl group of unsubstituted C6 to C60, a heteroaryl group of C5 to C60 substituted with a substituent R8, an heteroaryl group of unsubstituted C5 to C60, and Ar3 is not hydrogen; here, the substituents R7, R8 are each independently any one or more of a nitrile group, an alkyl group of C2 to C30, an aryl group of unsubstituted C6 to C60, an aryl group of C6 to C60 substituted with a substituent R9, a heteroaryl group of unsubstituted C5 to C60, and a heteroaryl group of C5 to C60 substituted with a substituent R10; here, the substituents R9, R10 are each independently any one or more of a nitrile group, an aryl group of C6 to C60;

l1, L2, L3 may each independently be any one of a single bond, a substituted or unsubstituted arylene group of C6 to C60, a substituted or unsubstituted heteroarylene group of C2 to C60, where the substituted arylene group of C6 to C60, the substituted heteroarylene group of C2 to C60 are meant to be substituted with one or more of the following groups: deuterium, halogen, nitro, nitrile group, aryl of C6 to C60, heteroaryl of C2 to C60;

in an exemplary embodiment, Y may be any one of O, S, NR4 and R4 may be phenyl.

In exemplary embodiments, the benzo-heterocycle structure-containing compound may be any one of the following compounds:

in the exemplary embodiment, it is contemplated that,

the refractive index of the compound containing a benzo-heterocycle structure at a wavelength of 460nm may be in the range of 2.11 to 2.31;

the refractive index of the benzo-heterocycle structure-containing compound at a wavelength of 530nm may be in the range of 1.95 to 2.19;

the refractive index of the compound containing a benzo-heterocycle structure at a wavelength of 620nm may be in a range of 1.88 to 2.09.

When the compound containing the benzo-heterocycle structure of the embodiment of the disclosure is used for forming a light extraction layer of a device, lithium fluoride (LIF) and a Chemical Vapor Deposition (CVD) encapsulation layer can be matched, and the refractive index is required to be high or low. When the refractive index of the compound containing a benzo-heterocycle structure in the embodiment of the disclosure is in the above range, the matching of the refractive index of the formed light extraction layer and the refractive index of the lithium fluoride and the CVD encapsulation layer can meet the requirement.

In exemplary embodiments, the compound having a benzo-heterocycle structure may have an absorption coefficient of 0.837 or more at a wavelength of 400nm and zero at a wavelength of 450nm and wavelengths greater than 450 nm.

In exemplary embodiments, the glass transition temperature of the compound containing a benzo-heterocycle structure may be above 121 ℃.

The embodiment of the disclosure also provides application of the compound containing the benzo heterocyclic structure as described above as a light extraction material.

Embodiments of the present disclosure also provide a light extraction material including a compound containing a benzo-heterocycle structure as described above.

In an exemplary embodiment, the electroluminescent device may include: an anode, a Hole Injection Layer (HIL), a Hole Transport Layer (HTL), an Electron Blocking Layer (EBL), a light Emitting Layer (EML), a Hole Blocking Layer (HBL), an Electron Transport Layer (ETL), an Electron Injection Layer (EIL), a cathode, and a light extraction Layer.

Fig. 1 is a schematic structural diagram of an electroluminescent device according to an exemplary embodiment of the present disclosure. As shown in fig. 1, the electroluminescent device may include: an anode 100, a hole injection layer 200, a hole transport layer 300, an electron blocking layer 400, a light emitting layer 500, a hole blocking layer 600, an electron transport layer 700, an electron injection layer 800, a cathode 900, and a light extraction layer 1000. The hole injection layer 200 is provided on a surface of the anode 100 side, the hole transport layer 300 is provided on a surface of the hole injection layer 200 on a side away from the anode 100, the electron blocking layer 400 is disposed on a surface of the hole transport layer 300 on a side away from the anode 100, the light emitting layer 500 is disposed on a surface of the electron blocking layer 400 on a side away from the anode 100, the hole blocking layer 600 is disposed on a surface of the light emitting layer 500 on a side away from the anode 100, the electron transport layer 700 is disposed on a surface of the hole blocking layer 600 on a side away from the anode 100, the electron injection layer 800 is disposed on a surface of the electron transport layer 700 on a side away from the anode 100, the cathode 900 is disposed on a surface of the electron injection layer 800 on a side away from the anode 100, the light extraction layer 1000 is disposed on a surface of the cathode 900 on a side away from the anode 100.

In an exemplary embodiment, the light extraction layer may be formed by evaporation using the light extraction material provided in the embodiments of the present disclosure.

In an exemplary embodiment, the anode may be a material having a high work function. For example, for a bottom emission type device, a transparent Oxide material such as Indium Tin Oxide (ITO) or Indium Zinc Oxide (IZO) may be used for the anode. Alternatively, for a top emission device, the anode may be a composite structure of metal and transparent Oxide, such as Ag/ITO (Indium Tin Oxide), Ag/IZO (Indium Zinc Oxide), Al/ITO, Al/IZO, or ITO/Ag/ITO, which can ensure good reflectivity.

In an exemplary embodiment, the material of the hole injection layer may include a transition metal oxide, for example, any one or more of molybdenum oxide, titanium oxide, vanadium oxide, rhenium oxide, ruthenium oxide, chromium oxide, zirconium oxide, hafnium oxide, tantalum oxide, silver oxide, tungsten oxide, and manganese oxide.

In another exemplary embodiment, the material of the hole injection layer may include a p-type dopant of a strong electron-withdrawing system and a hole transport material;

the p-type dopant may include any one or more of 2,3,6,7,10, 11-hexacyano-1, 4,5,8,9, 12-hexaazatriphenylene, 2,3,5, 6-tetrafluoro-7, 7 ', 8, 8' -tetracyano-p-benzoquinone (F4TCNQ), 1,2, 3-tris [ (cyano) (4-cyano-2, 3,5, 6-tetrafluorophenyl) methylene ] cyclopropane;

the hole transport material can comprise any one or more of arylamine hole transport materials, dimethyl fluorene hole transport materials and carbazole hole transport materials; for example, the hole transport material may include any one or more of 4,4 '-bis [ N- (1-naphthyl) -N-phenylamino ] biphenyl (NPB), N' -bis (3-methylphenyl) -N, N '-diphenyl- [1, 1' -biphenyl ] -4,4 '-diamine (TPD), 4-phenyl-4' - (9-phenylfluoren-9-yl) triphenylamine (BAFLP), 4 '-bis [ N- (9, 9-dimethylfluoren-2-yl) -N-phenylamino ] biphenyl (DFLDPBi), 4' -bis (9-Carbazolyl) Biphenyl (CBP), and 9-phenyl-3- [4- (10-phenyl-9-anthracenyl) phenyl ] -9H-carbazole (PCzPA).

In an exemplary embodiment, the hole transport layer may be formed by evaporation.

In an exemplary embodiment, the material of the electron blocking layer may include any one or more of an arylamine-based electron blocking material, a dimethylfluorene-based electron blocking material, and a carbazole-based electron blocking material; for example, the material of the electron blocking layer may include any one or more of 4,4 '-bis [ N- (1-naphthyl) -N-phenylamino ] biphenyl (NPB), N' -bis (3-methylphenyl) -N, N '-diphenyl- [1, 1' -biphenyl ] -4,4 '-diamine (TPD), 4-phenyl-4' - (9-phenylfluoren-9-yl) triphenylamine (BAFLP), 4 '-bis [ N- (9, 9-dimethylfluoren-2-yl) -N-phenylamino ] biphenyl (DFLDPBi), 4' -bis (9-Carbazolyl) Biphenyl (CBP), and 9-phenyl-3- [4- (10-phenyl-9-anthracenyl) phenyl ] -9H-carbazole (PCzPA) And (4) seed preparation.

In an exemplary embodiment, the electron blocking layer may be formed by evaporation.

In an exemplary embodiment, the material of the light emitting layer may include one light emitting material, or may include two or more light emitting materials. For example, a host light emitting material and a guest light emitting material doped into the host light emitting material may be included.

In an exemplary embodiment, the electroluminescent device may be a blue electroluminescent device, a green electroluminescent device, or a red electroluminescent device, the material of the light emitting layer of the blue electroluminescent device includes a blue light emitting material, the material of the light emitting layer of the green electroluminescent device includes a green light emitting material, and the material of the light emitting layer of the red electroluminescent device may include a red light emitting material.

In an exemplary embodiment, the blue light emitting material may include any one or more of a pyrene derivative-based blue light emitting material, an anthracene derivative-based blue light emitting material, a fluorene derivative-based blue light emitting material, a perylene derivative-based blue light emitting material, a styryl amine derivative-based blue light emitting material, and a metal complex-based blue light emitting material.

For example, the blue light emitting material may include N1, N6-bis ([1, 1' -biphenyl ] -2-yl) -N1, any one or more of N6-bis ([1,1 ' -biphenyl ] -4-yl) pyrene-1, 6-diamine, 9, 10-bis- (2-naphthyl) Anthracene (ADN), 2-methyl-9, 10-bis-2-naphthylanthracene (MADN), 2,5,8, 11-tetra-tert-butylperylene (TBPe), 4 ' -bis [4- (diphenylamino) styryl ] biphenyl (BDAV Bi), 4 ' -bis [4- (di-p-tolylamino) styryl ] biphenyl (DPAVBi), bis (4, 6-difluorophenylpyridine-C2, N) iridium picolinate (FIrpic).

In an exemplary embodiment, the green emitting material may include any one or more of a coumarin dye, a quinacridone copper derivative type green emitting material, a polycyclic aromatic hydrocarbon type green emitting material, a diamine anthracene derivative type green emitting material, a carbazole derivative type green emitting material, and a metal complex type green emitting material.

For example, the green emitting material may include any one or more of coumarin 6(C-6), coumarin 545T (C-525T), quinacridone copper (QA), N ' -Dimethylquinacridone (DMQA), 5, 12-Diphenylnaphthacene (DPT), N10, N10' -diphenyl-N10, N10' -bisanthrylene-9, 9 ' -dianthracene-10, 10' -diamine (abbreviated as BA-NPB), tris (8-hydroxyquinoline) aluminum (III) (abbreviated as Alq3), tris (2-phenylpyridine) iridium (Ir (ppy)3), and bis (2-phenylpyridine) iridium acetylacetonate (Ir (ppy)2 (acac)).

In an exemplary embodiment, the red light emitting material may include any one or more of a DCM-based red light emitting material and a metal complex-based red light emitting material.

For example, the red light emitting material may include any one or more of 4- (dicyanomethylene) -2-methyl-6- (4-dimethylaminostyryl) -4H-pyran (DCM), 4- (dicyanomethylene) -2-tert-butyl-6- (1,1,7, 7-tetramethyljulolidin-9-enyl) -4H-pyran (DCJTB), bis (1-phenylisoquinoline) (acetylacetonate) iridium (III) (ir (piq)2(acac)), platinum octaethylporphyrin (abbreviated as PtOEP), bis (2- (2 '-benzothienyl) pyridine-N, C3') (acetylacetonate) iridium (abbreviated as ir (btp)2 (acac).

In an exemplary embodiment, the light emitting layer may be formed by evaporation.

In an exemplary embodiment, the material of the hole blocking layer may include an aromatic heterocyclic-based hole blocking material, and for example, may include any one or more of a benzimidazole derivative-based hole blocking material, an imidazopyridine derivative-based hole blocking material, a benzimidazole phenanthridine derivative-based hole blocking material, a pyrimidine derivative-based hole blocking material, a triazine derivative-based hole blocking material, a quinoline derivative-based hole blocking material, an isoquinoline derivative-based hole blocking material, and a phenanthroline derivative-based hole blocking material.

For another example, the hole blocking layer material may include 2- (4-biphenylyl) -5- (4-tert-butylphenyl) -1,3, 4-oxadiazole (PBD), 1, 3-bis [5- (p-tert-butylphenyl) -1,3, 4-oxadiazol-2-yl ] benzene (OXD-7), 3- (4-tert-butylphenyl) -4-phenyl-5- (4-biphenylyl) -1,2, 4-Triazole (TAZ), 3- (4-tert-butylphenyl) -4- (4-ethylphenyl) -5- (4-biphenylyl) -1,2, 4-triazole (p-EtTAZ), bathophenanthroline (BPhen), (BCP), 4, any one or more of 4' -bis (5-methylbenzoxazol-2-yl) stilbenes (BzOs).

In an exemplary embodiment, the hole blocking layer may be formed by evaporation.

In an exemplary embodiment, the material of the electron transport layer may include an aromatic heterocyclic-based electron transport material, and for example, may include any one or more of a benzimidazole derivative-based electron transport material, an imidazopyridine derivative-based electron transport material, a benzimidazole phenanthridine derivative-based electron transport material, a pyrimidine derivative-based electron transport material, a triazine derivative-based electron transport material, a quinoline derivative-based electron transport material, an isoquinoline derivative-based electron transport material, and a phenanthroline derivative-based electron transport material.

As another example, the material of the electron transport layer may include 2- (4-biphenyl) -5- (4-tert-butylphenyl) -1,3, 4-oxadiazole (PBD), 1, 3-bis [5- (p-tert-butylphenyl) -1,3, 4-oxadiazol-2-yl ] benzene (OXD-7), 3- (4-tert-butylphenyl) -4-phenyl-5- (4-biphenyl) -1,2, 4-Triazole (TAZ), 3- (4-tert-butylphenyl) -4- (4-ethylphenyl) -5- (4-biphenyl) -1,2, 4-triazole (p-EtTAZ), bathophenanthroline (BPhen), (BCP) Any one or more of 4, 4' -bis (5-methylbenzoxazol-2-yl) stilbenes (BzOs).

In an exemplary embodiment, the electron transport layer may be formed by evaporation.

In an exemplary embodiment, the material of the electron injection layer may include any one or more of an alkali metal electron injection material and a metal electron injection material.

For example, the electron injection layer material may include any one or more of LiF, Yb, Mg, Ca.

In an exemplary embodiment, the electron injection layer may be formed by evaporation.

In exemplary embodiments, the cathode may be formed using a metal having a relatively low work function, such as Al, Ag, Mg, or the like, or an alloy containing a metal material having a low work function.

In an exemplary embodiment, the display apparatus may include a plurality of the electroluminescent devices. For example, the electroluminescent device may be a blue electroluminescent device, a green electroluminescent device, or a red electroluminescent device, and the display apparatus may include a blue electroluminescent device, a green electroluminescent device, and a red electroluminescent device.

The display device can be any product or component with a display function, such as a mobile phone, a tablet personal computer, a television, a display, a notebook computer, a digital photo frame, a navigator, a vehicle-mounted display, an intelligent watch, an intelligent bracelet and the like.

The following are tests and comparisons of the synthetic procedures and performance of compounds containing benzo-heterocyclic structures of some exemplary embodiments of the present disclosure.

Synthesis example 1: synthesis of Compound 1

A500 ml reaction flask was purged with nitrogen, and then added with A10.04mol of a raw material, Tetrahydrofuran (THF)300ml, B10.04mol of a raw material, and tetrakis (triphenylphosphine) palladium 0.004mol, respectively, followed by stirring, and then added with K₂CO₃Heating 0.04ml of water solution to 80 ℃, carrying out reflux reaction for 12 hours, sampling a sample point plate, and completely reacting; naturally cooling, extracting with dichloromethane, layering, drying the extract with anhydrous sodium sulfate, filtering, rotary evaporating the filtrate, and purifying with silica gel column to obtain intermediate C1 with HPLC purity of 99.3% and yield of 84%.

Introducing nitrogen into a three-neck flask, adding the intermediate C10.04mol, the raw material B20.04mol, 300ml of N, N-Dimethylformamide (DMF) and 0.004mol of palladium acetate into the three-neck flask, stirring the mixture, and then adding 0.04mol of K₃PO₄Heating the aqueous solution to 150 ℃, carrying out reflux reaction for 24 hours, and sampling a sample point plate to complete the reaction; cooling naturally, extracting with dichloromethane, layering, and collecting extractive solutionDrying with sodium sulfate, filtering, rotary evaporating the filtrate, and purifying with silica gel column to obtain intermediate C2 with HPLC purity of 99.4% and yield of 83%.

Introducing nitrogen into a three-neck flask, adding the intermediate C20.04mol, DMF300ml, the raw material B30.04mol and palladium acetate 0.004mol, stirring, and then adding K0.04 mol₃PO₄Heating the aqueous solution to 150 ℃, carrying out reflux reaction for 24 hours, and sampling a sample point plate to complete the reaction; naturally cooling, extracting with dichloromethane, layering, drying the extract with anhydrous sodium sulfate, filtering, rotary evaporating the filtrate, and purifying with silica gel column to obtain target product compound 1 with HPLC purity of 99.5% and yield of 75%.

Mass spectrum m/z: 685.81, element content (%): c₄₄H₂₇N₇S，C，77.06；H，3.97；S，4.67；N，14.30。

¹H NMR(500MHz，CDCl₃)：δ8.69(2H)，8.45(1H)，8.37(1H)，8.24-8.2(1H)，8.17(1H)，8.03(2H)，7.96-7.93(5H)，7.8-7.77(4H)，7.56-7.54(3H)，7.49(1H)，7.38(1H)7.25-6.9(4H)。

Synthesis example 2: synthesis of Compound 2

The procedure for the synthesis of intermediate C1 was the same as in synthesis example 1.

The procedure for the synthesis of intermediate C3 was similar to that of intermediate C2 in synthesis example 1, except that starting material B2 was changed to B4, and the other steps were the same.

The synthesis of compound 2 was similar to that of compound 1 in synthesis example 1, except that intermediate C2 was replaced with intermediate C3, and the other steps were the same.

Mass spectrum m/z: 620.21, element content (%): c₃₉H₂₄N₈O，C，75.47；H，3.90；O，2.58；N，18.05。

¹H NMR(500MHz，CDCl₃)：δ8.69(3H)，8.37(1H)，8.03(2H)，7.96(9H)，7.8-7.77(4H)，7.74(2H)，7.54(4H)，7.38(4H)，7.25-6.9(3H)。

Synthesis example 3: synthesis of Compound 4

The synthesis process of compound 4 was similar to that of compound 2 in synthesis example 2, except that the starting material B3 was replaced with the starting material B4, and the other steps were the same.

Mass spectrum m/z: 619.21, element content (%): c₄₀H₂₅N₇O，C，77.53；H，4.07；O，2.58；N，15.82。

¹H NMR(500MHz，CDCl₃)：δ8.69(3H)，8.52-8.32(3H)，7.96-7.92(7H)，7.8-7.77(4H)，7.74(2H)，7.65-7.45(2H)，7.38(4H)，7.25-6.9(3H)。

Synthesis example 4: synthesis of Compound 6

The procedure for the synthesis of intermediate C4 was similar to that of intermediate C3 in synthesis example 2, except that starting material B4 was replaced with starting material B5, and the other steps were the same.

The synthesis of compound 6 was similar to that of compound 2 in synthesis example 2, except that intermediate C3 was replaced with intermediate C4, and the other steps were the same.

Mass spectrum m/z: 619.22, element content (%): c₃₉H₂₅N₉，C，75.59；H，4.07；N，20.34。

1H NMR(500MHz，CDCl₃)：δ8.69(2H)，8.52(2H)，8.37(1H)，8.03-7.96(4H)，7.8-7.77(4H)，7.54(2H)，7.35-6.9(4H)。

Synthesis example 5: synthesis of Compound 9

The procedure for the synthesis of intermediate C5 was similar to that of intermediate C4 in synthesis example 4, except that starting material B5 was replaced with starting material 6, and the other steps were the same.

The synthesis of compound 9 was similar to that of compound 2 in synthesis example 2, except that intermediate C3 was replaced with intermediate C5, and the other steps were the same.

Mass spectrum m/z: 744.27, element content (%): c₅₀H₃₂N₈，C，80.63；H，4.33；N，15.04。

¹H NMR(500MHz，CDCl₃)：δ8.69(2H)，8.55(1H)，8.37-8.31(2H)，8.03-7.91(8H)，7.8-7.74(5H)，7.62-7.5(7H)，7.38-7.35(2H)，7.25(2H)，7.16-6.9(3H)。

Synthesis example 6: synthesis of Compound 16

The procedure for the synthesis of intermediate C6 was similar to that of intermediate C5 in synthesis example 5, except that starting material B6 was replaced with starting material B7, and the other steps were the same.

The synthesis of compound 16 was similar to that of compound 2 in synthesis example 2, except that intermediate C3 was replaced with intermediate C6, and the other steps were the same.

Mass spectrum m/z: 688.24, element content (%): c₄₄H₂₈N₈，C，79.02；H，4.22；N，16.76。

¹H NMR(500MHz，CDCl₃)：δ8.69(3H)，8.55(1H)，8.37-8.19(2H)，8.03-7.96(6H)，7.94-7.91(5H)，7.8-7.77(4H)，7.62(2H)，7.58-7.5(5H)，7.38-7.35(3H)，7.25-7.2(2H)，7.16-6.9(3H)。

Synthesis example 7: synthesis of Compound 18

The procedure for the synthesis of intermediate C7 was similar to that of intermediate C1 in synthesis example 1, except that starting material B1 was replaced with starting material B8.

The synthesis process of intermediate C8 is similar to that of intermediate C3 in synthetic example 2, except that C1 is replaced by C7, and other steps are the same.

The procedure for the synthesis of compound 18 was similar to that of compound 16 in synthesis example 6, except that intermediate C6 was replaced with intermediate C8, and the other steps were the same.

Mass spectrum m/z: 670.22, element content (%): c₄₃H₂₆N₈O，C，77.00；H，3.91；N，16.71，O，2.39。

¹H NMR(500MHz，CDCl₃)：δ9.23(1H)，8.69(2H)，8.53(1H)，8.08-8.03(4H)，7.96(9H)，7.91(1H)，7.8-7.7(8H)，7.69-7.62(3H)，7.58-7.54(3H)，7.38(4H)，7.25(3H)。

Synthesis example 8: synthesis of Compound 1

Intermediate F1 synthesis: in a 500mL three-necked flask, nitrogen gas was introduced, and 0.08mol of D1(1, 4-dibromobenzene) as a starting material, 200mL of THF, 0.2mol of E1 (phenylboronic acid) as a starting material, and 0.0016mol of tetrakis (triphenylphosphine) palladium were added thereto, followed by stirring and then 0.12mol of K was added₂CO₃Heating the aqueous solution (2mol/L) to 80 ℃, refluxing and reacting for 15 hours, taking a sample, and completely reacting. Naturally cooling, extracting with 200ml dichloromethane, demixing, drying the extract with anhydrous sodium sulfate, filtering, rotary evaporating the filtrate, and purifying with silica gel column to obtain intermediate F1 with HPLC purity of 99.6% and yield of 85.3%.

Intermediate F2 synthesis: a500 mL three-necked flask was charged with nitrogen, charged with 0.04mol of E2 (2-bromo-4, 6-dichloro-1, 3-diazine) as a starting material, 300mL of DMF, 0.048mol of intermediate F1 and 0.0004mol of palladium acetate, stirred, and then charged with 0.06mol of K₃PO₄Heating the aqueous solution to 130 ℃, refluxing and reacting for 10 hours, taking a sample, and completely reacting. Naturally cooling, adding water, filtering the mixture and drying in a vacuum drying oven, and purifying the obtained residue with a silica gel column to obtain an intermediate F2; HPLC purity 99.7%, yield 87.3%.

Compound 1' synthesis:

a500 mL three-necked flask was charged with nitrogen, 0.02mol of intermediate F2, 300mL of DMF, 0.06mol of raw material E3, and 0.0004mol of palladium acetate were added thereto, and the mixture was stirred, followed by addition of 0.04mol of K₃PO₄Heating the aqueous solution to 150 ℃, refluxing and reacting for 24 hours, sampling a sample, and reactingAnd (4) completing. Naturally cooling, extracting with 400ml dichloromethane, demixing, drying the extract with anhydrous sodium sulfate, filtering, rotary evaporating the filtrate, and purifying with silica gel column to obtain the target product (compound 1'), with HPLC purity of 99.3% and yield of 85.7%.

Mass spectrum m/z: 618.2, element content (%): c₄₂H₂₆N₄O₂，C，81.54；H，4.24；N，9.06；O，5.17；

¹H NMR(500MHz，CDCl₃)：δ8.3(4H)，8.23(1H)，7.96(6H)，7.75-7.74(6H)，7.49(2H)，7.41-7.38(5H)，7.25(2H)。

Synthesis example 9: synthesis of Compound 2

The synthesis of compound 2 ' is similar to that of compound 1 ' in that starting material E1 is replaced with starting material E4 (2-naphthalene boronic acid) to give intermediate F3, intermediate F4 is then obtained from intermediate F3, and compound 2 ' is formed by reaction. The target product compound 2' is obtained by extraction, delamination, filtration, rotary evaporation of filtrate and purification by silica gel column, the HPLC purity is 99.1 percent, and the yield is 86.3 percent.

Mass spectrum m/z: 668.7, element content (%): c₄₆H₂₈N₄O₂，C，82.62；H，4.22；N，8.38；O，4.78；

¹H NMR(500MHz，CDCl₃)：δ8.3(4H)，8.23-8.06(3H)，7.99-7.96(7H)，7.74-7.55(7H)，7.38(5H)，7.25(2H)。

Synthesis example 10: synthesis of Compound 3

The synthesis of compound 3 ' is similar to that of compound 2 ', starting material D1 is reacted with starting material E4 to form intermediate F3, intermediate F3 is then reacted with starting material E5 to form intermediate F5, and intermediate F5 is reacted again to form compound 3 '. The target product compound 3' is obtained by extraction, delamination, filtration, rotary evaporation of the filtrate and purification by silica gel column, the HPLC purity is 98.7%, and the yield is 87.2%.

Mass spectrum m/z: 677.8, element content (%): c₄₉H₃₁N₃O，C，86.83；H，4.61；N，6.20；O，2.36；

¹H NMR(500MHz，CDCl₃)：δ8.3(4H)，8.23-8.06(5H)，7.99-7.96(6H)，7.85-7.55(10H)，7.38(4H)，7.25(2H)。

Synthesis example 11: synthesis of Compound 4

The synthesis of compound 4 ' is similar to that of compound 1 ', and intermediate F2 is reacted with starting material E6 to form compound 4 '. The target product compound 4' is obtained by extraction, delamination, filtration, rotary evaporation of filtrate and silica gel column purification, with the HPLC purity of 97.9% and the yield of 86.3%.

Mass spectrum m/z: 650.8, element content (%): c₄₂H₂₆N₄S₂，C，77.51；H，4.03；N，8.61；S，9.85；

¹H NMR(500MHz，CDCl₃)：δ8.3(4H)，8.23-8.02(5H)，7.96(6H)，7.75(2H)，7.53-7.41(7H)，7.25(2H)。

Synthesis example 12: synthesis of Compound 5

The synthesis of compound 5 is similar to that of compound 1'. After the compound 5 'is formed, the target product compound 5' is obtained by extraction, delamination, filtration, rotary evaporation of filtrate and silica gel column purification, wherein the HPLC purity is 98.1 percent, and the yield is 85.6 percent.

Mass spectrum m/z: 651.8, element content (%): c₄₁H₂₅N₅S₂，C，75.55；H，3.87；N，10.74；S，9.84；

¹H NMR(500MHz，CDCl₃)：δ8.69(2H)，8.37(1H)，8.3-8.23(5H)，8.18-8.02(4H)，7.96(6H)，753-7.51(4H)，7.38(1H)，7.14(1H)，6.9(1H)。

Refractive index of compound containing benzo-heterocycle structure

Testing the refractive index by an ellipsometer; the instrument scanning range is 245nm to 1000 nm; a thin film of the compound was formed by evaporation from a silicon wafer, the thickness of the thin film was 50nm, and the refractive index was then measured.

Among the comparative compounds CP1, CP2 are the following:

the test results are shown in table 1 and fig. 2; fig. 2 is a graph of refractive index change at different wavelengths for compound 1' of an exemplary example of the present disclosure and the compound of comparative example 1.

TABLE 1

It can be seen that the refractive index of the compounds of the examples of the present disclosure is higher at different wavelengths compared to the compounds CP1, CP2 of comparative examples 1, 2. The refractive index is an important physical parameter of the light extraction material, and the light coupling efficiency of the device is directly determined and improved by the size of the refractive index. Therefore, the compound disclosed by the embodiment of the disclosure is suitable for being used as a light extraction material, is beneficial to light coupling output of an OLED device, and improves the efficiency of the device.

Absorption coefficient of compound containing benzo-heterocycle structure

A thin film containing a compound with a benzo heterocyclic structure is formed by evaporation of a glass substrate, the thickness of the thin film is 50nm, and then an ultraviolet visible absorption spectrometer is used for testing the absorption coefficient.

The test results are shown in table 2 and fig. 3; fig. 3 is a graph of the change in absorption coefficient at different wavelengths for compound 1' of an exemplary example of the present disclosure and the compound of comparative example 1.

TABLE 2

In order to protect the OLED device from being damaged by ultraviolet light in the external environment, the CPL material needs to have strong absorption capacity at about 400nm, absorb the external ultraviolet light and prevent the device from aging. While not absorbing light emitted from the OLED device itself, so that absorption at 450nm and beyond needs to be almost 0.

It can be seen that the absorbance coefficient at 400nm is significantly higher for the compounds of the examples of the present disclosure compared to the comparative compounds CP1, CP2, and therefore better absorption of ultraviolet light; furthermore, the compounds of the examples of the present disclosure have zero absorption at 450nm and zero absorption at wavelengths greater than 450nm (not shown), indicating that light emitted from the device itself is not absorbed.

Glass transition temperature of compound containing benzo-heterocycle structure

The measuring instrument for the glass transition temperature is a DSC differential scanning calorimeter; the testing atmosphere is nitrogen, the heating rate is 10 ℃/min, and the temperature range is 50 ℃ to 300 ℃; the measured glass transition temperatures (Tg) are shown in table 3.

TABLE 3

The high and low glass transition temperature (Tg) determines the thermal stability of the material in evaporation, and the higher the Tg, the better the thermal stability of the material. Generally, the Tg can meet the requirement of evaporation when the Tg is more than 110 ℃. It can be seen that the glass transition temperatures, Tg, of the compounds of the examples of the present disclosure are all high, all above 120 ℃. Therefore, the compound disclosed by the embodiment of the disclosure is suitable for being used as a light extraction material, has good stability in an evaporation process, can solve the problem that decomposition impurities are increased due to unstable materials caused by heating in the evaporation process, and is beneficial to improving the stability of materials in a device and prolonging the service life of the device.

The performance of the electroluminescent devices of some exemplary embodiments of the present disclosure was tested and compared below.

OLED device Performance test example 1

In this test example, the material of the CPL layer was selected among compounds 1 to 50 provided in the examples of the present disclosure.

The chemical structures of some of the raw materials used therein are shown in Table 4.

TABLE 4

The preparation process of the OLED device comprises the following steps: cleaning and drying an ITO substrate prepared in advance; sequentially evaporating an HIL material, an HTL material and an EBL material on the anode; then evaporating a luminescent layer material; evaporating an HBL material, an ETL material and an EIL material on the light-emitting layer; then evaporating a cathode; over the cathode, the compound of the disclosed embodiments is evaporated to form a CPL layer. The device is packaged by glass UV. Thin-Film Encapsulation (TFE) can also be adopted, but LIF or organic materials with the refractive index n less than or equal to 1.6 need to be evaporated on CPL.

Structure and thickness of the first blue OLED device

ITO/m-MTDATA:F4TCNQ 3％10nm/m-MTDATA 100nm/CBP 10nm/BH1:BD1 5％20nm/TPBI 5nm/BCP:Liq 1:1 30nm/Yb 1nm/Mg：Ag 13nm/CPL 60nm

Structure and thickness of first green OLED device

ITO/m-MTDATA:F4TCNQ 3％10nm/m-MTDATA 100nm/CBP 45nm/GH:GD 10％40nm/TPBI 5nm/BCP:Liq 1:1 30nm/Yb 1nm/Mg：Ag 13nm/CPL 60nm

Structure and thickness of first red OLED device

ITO/m-MTDATA:F4TCNQ 3％10nm/m-MTDATA 100nm/CBP 75nm/RH:RD 3％45nm/TPBI 5nm/BCP:Liq 1:1 30nm/Yb 1nm/Mg：Ag 13nm/CPL 60nm

The performance of the first blue OLED device is shown in table 5.

TABLE 5

OLED device Performance test example 2

In this test example, the material of the CPL layer was selected among compounds 1 'to 4' provided in the examples of the present disclosure.

The chemical structures of some of the raw materials used therein are shown in Table 6.

TABLE 6

Structure and thickness of the second blue OLED device

ITO/p-doping (2%): NPB 10nm/NPB 110nm/TCTA 5nm/BH2 BD 23% 20nm/TPBi 5nm/Bphen Liq 50% 30nm/Yb 1nm/Mg Ag 13nm/CPL 65nm

The performance of the second blue OLED device is shown in table 7.

TABLE 7

It can be seen that compared with blue OLED devices prepared by using CP1 and CP2 as CPL materials, the blue OLED devices prepared by using the compound of the embodiments of the present disclosure as CPL materials have higher light extraction efficiency (EQE), better stability, and improved efficiency and lifetime.

The light extraction efficiency trends of the red and green OLED devices are similar to those of the blue OLED device. Therefore, the light extraction efficiency of the OLED device can be improved by using the high-refractive-index compound of the embodiment of the present disclosure as the CPL material of the OLED device. And the service life of the device is relatively prolonged due to the improvement of the thermal stability of the CPL material.

Although the embodiments disclosed in the present disclosure are described above, the descriptions are only for the convenience of understanding the present disclosure, and are not intended to limit the present disclosure. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the disclosure, and it is intended that the scope of the disclosure be limited only by the appended claims.

Claims

1. A compound containing a benzo-heterocycle structure is characterized in that the structural general formula of the compound containing the benzo-heterocycle structure is as follows:

wherein at least one of Z1, Z2 and Z3 is N, and the others are C (H);

m, n are each independently 0,1 or 2, and m + n is 2.

2. The benzo-heterocycle structure-containing compound of claim 1, wherein each of Z1, Z2, Z3 is N; alternatively, two of Z1, Z2, Z3 are N and the other is c (h).

3. The benzo-heterocycle structure-containing compound of claim 1, wherein R1, R2 are each independently any one of the following groups:

4. the compound containing a benzo-heterocycle structure of claim 1, wherein each of L1, L2, and L3 is independently any one of a single bond, phenylene, and naphthylene.

5. The benzo-heterocycle structure-containing compound of claim 1,

r1 is a substituted or unsubstituted group of formula II, R2 is Ar 2; or

R1 and R2 are each independently any one of a substituted or unsubstituted group represented by formula III and a substituted or unsubstituted group represented by formula IV.

6. The benzo-heterocycle structure-containing compound of claim 5, wherein R1 is a substituted or unsubstituted group of formula II, R2 is substituted or unsubstituted Ar2, m is 1, n is 1;

at least one of Z1, Z2, Z3 is N, the others are c (h);

r3 is hydrogen, deuterium, halogen, nitro, nitrile, substituted or unsubstituted C1 to C60 alkyl, substituted or unsubstituted C2 to C30 alkenyl, substituted or unsubstituted C1 to C30 alkoxy, substituted or unsubstituted C1 to C30 thioether, substituted or unsubstituted C6 to C60 aryl, substituted or unsubstituted C5 to C60 heteroaryl; here, substituted C1 to C60 alkyl, substituted C2 to C30 alkenyl, substituted C1 to C30 alkoxy, substituted C1 to C30 thioether, substituted C6 to C60 aryl, substituted C5 to C60 heteroaryl means substituted with one or more of the following groups: hydrogen, deuterium, halogen, nitro, nitrile group, alkyl group of C1 to C60, alkenyl group of C2 to C30, alkoxy group of C1 to C30, thioether group of C1 to C30, aryl group of C6 to C60, heteroaryl group of C5 to C60;

ar1, Ar2 and Ar3 are respectively and independently any one of aryl of C6 to C60 substituted by substituent R7, aryl of unsubstituted C6 to C60, heteroaryl of C5 to C60 substituted by substituent R8 and heteroaryl of unsubstituted C5 to C60; here, the substituents R7, R8 are each independently any one or more of an alkyl group of C2 to C30, an aryl group of unsubstituted C6 to C60, an aryl group of C6 to C60 substituted with a substituent R9, a heteroaryl group of unsubstituted C5 to C60, and a heteroaryl group of C5 to C60 substituted with a substituent R10; here, the substituents R9, R10 are each independently any one or more of aryl groups of C6 to C60;

l1, L2, L3 are each independently any one of a single bond, a substituted or unsubstituted arylene group of C6 to C60, a substituted or unsubstituted heteroarylene group of C2 to C60, where the substituted arylene group of C6 to C60, the substituted heteroarylene group of C2 to C60 are substituted with one or more of the following groups: deuterium, halogen, nitro, nitrile group, aryl of C6-C60, heteroaryl of C2-C60.

7. The benzo-heterocycle structure-containing compound of claim 6, wherein X1, X2 are both N; alternatively, one of X1 and X2 is N, and the other is c (h).

8. The benzo-heterocycle structure-containing compound of claim 7, wherein each of Z1, Z2, Z3 is N; or Z1 and Z3 are N, and Z2 is C (H); alternatively, Z1 and Z2 are N, and Z3 is C (H).

9. The benzo-heterocycle structure-containing compound of claim 5, wherein R1, R2 are each independently any one of a substituted or unsubstituted group of formula III, a substituted or unsubstituted group of formula IV;

z2, Z3 are N, Z1 is C (H);

r4, R5, R6 are each independently hydrogen, deuterium, halogen, nitro, nitrile group, substituted or unsubstituted C1 to C60 alkyl group, substituted or unsubstituted C3 to C30 cycloalkyl group, substituted or unsubstituted C6 to C60 aryl group, substituted or unsubstituted C5 to C60 heteroaryl group; here, substituted C1 to C60 alkyl, substituted C3 to C30 cycloalkyl, substituted C6 to C60 aryl, substituted C5 to C60 heteroaryl means substituted with one or more of the following groups: hydrogen, deuterium, halogen, nitro, nitrile group, alkyl group of C1 to C60, cycloalkyl group of C3 to C30, aryl group of C6 to C60, heteroaryl group of C5 to C60;

10. The benzo-heterocycle structure-containing compound of claim 9, wherein Y is any one of O, S, NR4, and R4 is phenyl.

11. The benzo-heterocycle structure-containing compound according to claim 1, wherein the benzo-heterocycle structure-containing compound is any one of the following compounds:

12. the benzo-heterocycle structure-containing compound of any one of claims 1 to 11, wherein,

the refractive index of the compound containing a benzo heterocyclic structure at a wavelength of 460nm is in the range of 2.11 to 2.31;

the refractive index of the compound containing a benzo-heterocycle structure at a wavelength of 530nm is in the range of 1.95 to 2.19;

the refractive index of the compound containing a benzo-heterocycle structure at a wavelength of 620nm is in a range of 1.88 to 2.09.

13. The benzo-heterocycle structure-containing compound according to any one of claims 1 to 11, wherein the compound having a benzo-heterocycle structure has an absorption coefficient of 0.837 or more at a wavelength of 400nm and an absorption coefficient of zero at a wavelength of 450nm and at a wavelength of more than 450 nm.

14. The benzo-heterocycle structure-containing compound of any one of claims 1 to 11, wherein the glass transition temperature of the benzo-heterocycle structure-containing compound is 121 ℃ or higher.

15. An electroluminescent device comprising a light extraction layer, wherein a material of the light extraction layer comprises the compound having a benzo-heterocycle structure according to any one of claims 1 to 14.

16. The electroluminescent device of claim 15, further comprising: an anode, a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a cathode.

17. The electroluminescent device of claim 16, wherein the material of the hole injection layer comprises a transition metal oxide; alternatively, the material of the hole injection layer comprises a hole transport material and a p-type dopant;

wherein the transition metal oxide comprises any one or more of molybdenum oxide, titanium oxide, vanadium oxide, rhenium oxide, ruthenium oxide, chromium oxide, zirconium oxide, hafnium oxide, tantalum oxide, silver oxide, tungsten oxide and manganese oxide;

the p-type dopant includes any one or more of 2,3,6,7,10, 11-hexacyano-1, 4,5,8,9, 12-hexaazatriphenylene, 2,3,5, 6-tetrafluoro-7, 7 ', 8, 8' -tetracyano-p-benzoquinone, 1,2, 3-tris [ (cyano) (4-cyano-2, 3,5, 6-tetrafluorophenyl) methylene ] cyclopropane;

the hole transport material comprises any one or more of arylamine hole transport materials, dimethyl fluorene hole transport materials and carbazole hole transport materials;

the hole transport layer is made of one or more of arylamine hole transport materials, dimethyl fluorene hole transport materials and carbazole hole transport materials;

the material of the electron blocking layer comprises any one or more of arylamine electron blocking materials, dimethyl fluorene electron blocking materials and carbazole electron blocking materials.

18. The electroluminescent device according to claim 16, wherein the electroluminescent device is a blue electroluminescent device, a green electroluminescent device or a red electroluminescent device, the material of the light-emitting layer of the blue electroluminescent device comprises a blue light-emitting material, the material of the light-emitting layer of the green electroluminescent device comprises a green light-emitting material, and the material of the light-emitting layer of the red electroluminescent device comprises a red light-emitting material;

the blue luminescent material comprises any one or more of a pyrene derivative blue luminescent material, an anthracene derivative blue luminescent material, a fluorene derivative blue luminescent material, a perylene derivative blue luminescent material, a styryl amine derivative blue luminescent material and a metal complex blue luminescent material;

the green luminescent material comprises any one or more of coumarin dye, quinacridone copper derivative green luminescent materials, polycyclic aromatic hydrocarbon green luminescent materials, diamine anthracene derivative green luminescent materials, carbazole derivative green luminescent materials and metal complex green luminescent materials;

the red luminescent material comprises any one or more of DCM red luminescent materials and metal complex red luminescent materials.

19. The electroluminescent device according to claim 16, wherein the material of the hole blocking layer comprises any one or more of a benzimidazole derivative type hole blocking material, an imidazopyridine derivative type hole blocking material, a benzimidazole phenanthridine derivative type hole blocking material, a pyrimidine derivative type hole blocking material, a triazine derivative type hole blocking material, a quinoline derivative type hole blocking material, an isoquinoline derivative type hole blocking material, and a phenanthroline derivative type hole blocking material;

the material of the electron transmission layer comprises any one or more of benzimidazole derivative electron transmission materials, imidazopyridine derivative electron transmission materials, benzimidazole phenanthridine derivative electron transmission materials, pyrimidine derivative electron transmission materials, triazine derivative electron transmission materials, quinoline derivative electron transmission materials, isoquinoline derivative electron transmission materials and phenanthroline derivative electron transmission materials;

the material of the electron injection layer includes any one or more of an alkali metal electron injection material and a metal electron injection material.

20. A display device comprising an electroluminescent device according to any one of claims 15 to 19.