CN112242492B

CN112242492B - Organic electroluminescent device, device and preparation method

Info

Publication number: CN112242492B
Application number: CN201910649760.8A
Authority: CN
Inventors: 孙龙; 刘嵩
Original assignee: Guan Eternal Material Technology Co Ltd
Current assignee: Guan Eternal Material Technology Co Ltd
Priority date: 2019-07-18
Filing date: 2019-07-18
Publication date: 2023-12-01
Anticipated expiration: 2039-07-18
Also published as: CN112242492A

Abstract

The invention provides an organic electroluminescent device, which comprises one or more light emitting areas, wherein each light emitting area sequentially comprises a cathode, a light emitting layer, an electron blocking layer and an anode, the electron blocking layer comprises a first electron blocking layer, the electron blocking layer of at least one light emitting area further comprises a second electron blocking layer positioned between the anode and the first electron blocking layer, the first electron blocking layer is composed of a first electron blocking layer material, and the second electron blocking layer comprises a second electron blocking layer host material and a second electron blocking layer guest material. The invention also provides an organic light emitting device comprising the organic electroluminescent device and a method for preparing the organic electroluminescent device.

Description

Organic electroluminescent device, device and preparation method

Technical Field

The present invention relates to the field of organic electroluminescence, and more particularly, to an organic electroluminescent device, and an organic light emitting apparatus including the same and a method of manufacturing the same.

Background

The organic electroluminescent display (english name Organic Light Emiting Display, abbreviated as OLED) is an active light emitting display device, and is expected to be the next generation mainstream panel display technology because of its advantages of simple manufacturing process, low cost, high contrast, wide viewing angle, low power consumption, etc., and is one of the most focused technologies in the current panel display technology.

In top-emission devices, hole transporting materials (including hole injection layers, hole transport layers, electron blocking layers) are typically made thicker, especially for red devices, to a thickness of up to 250nm, in order to achieve optical path-conforming devices. The device thickness of the layer is too thick, so that the problems of higher voltage, reduced efficiency and the like of the device are caused. The p-type dopant is usually doped in the hole transport material to improve the hole transport capability, further improve the device efficiency and reduce the device voltage, but if too much p-type dopant is added, the device crosstalk and quenching will be caused.

Disclosure of Invention

In view of the above problems of the prior art, researchers of the present invention have designed a novel device structure through continuous intensive research, by making a light emitting layer not in direct contact with a layer doped with a p-type dopant, the occurrence of the problem of device crosstalk is reduced on the basis of improving hole transporting capability, and quenching due to the introduction of the p-type dopant is avoided.

In one aspect, an organic electroluminescent device is provided, comprising one or more light emitting regions, each light emitting region comprising, in sequence, a cathode, a light emitting layer, an electron blocking layer, and an anode, the electron blocking layer comprising a first electron blocking layer, wherein the electron blocking layer of at least one light emitting region further comprises a second electron blocking layer located between the anode and the first electron blocking layer, the first electron blocking layer being comprised of a first electron blocking layer material, the second electron blocking layer comprising a second electron blocking layer host material and a second electron blocking layer guest material.

In some embodiments, the first electron blocking layer is the same for each light emitting region in the organic electroluminescent device.

In some embodiments, the molar ratio of the second electron blocking layer host material to the second electron blocking layer guest material in the organic electroluminescent device is from 1:0.01 to 1:0.09.

In some embodiments, the second electron blocking layer host material and the second electron blocking layer guest material in the organic electroluminescent device satisfy the following energy level relationship:

︱LUMO _{second electron blocking layer guest material} ︱－︱HOMO _{Second electron blocking layer main material} ︱≥0.05。

In some embodiments, the first electron blocking layer has a thickness of 5 to 60nm, preferably 5 to 40nm, and the second electron blocking layer has a thickness of 40 to 100nm, preferably 60 to 100nm, in the organic electroluminescent device.

In some embodiments, the first electron blocking layer material is the same as the second electron blocking layer host material in the organic electroluminescent device, and the material has a hole mobility of not less than 3.0X10 ^-5 cm ² Vs and satisfies |lumo _{Luminescent host material} ︱－︱LUMO _{Second electron blocking layer main material} Is more than or equal to 0.5, and the triplet state energy level of the main material of the second electron blocking layer is higher than that of the light-emitting main bodyTriplet energy level of material, or

The first electron blocking layer material is different from the second electron blocking layer main material, and the mobility of the first electron blocking layer material is not less than 8.0X10 ^-5 cm ² Vs and satisfies% _{Luminescent host material} ︱＞︱HOMO _{First electron blocking layer material} ︱＞︱HOMO _{Second electron blocking layer main material} ︱。

In some embodiments, the second electron blocking layer in the organic electroluminescent device is formed by co-evaporating the second electron blocking layer host material with the second electron blocking layer guest material.

In some embodiments, at least one light emitting region including the first electron blocking layer and the second electron blocking layer in the organic electroluminescent device is a red light emitting region, a yellow light emitting region, or a green light emitting region.

In some embodiments, the thickness of the second electron blocking layer in the organic electroluminescent device is 80-100nm when the light emitting region is a red light emitting region, 60-80nm when the light emitting region is a green light emitting region, and 70-90nm when the light emitting region is a yellow light emitting region.

In some embodiments, the organic electroluminescent device comprises a plurality of light emitting regions, wherein at least one of the light emitting regions is a blue light emitting region, and the electron blocking layer thereof is comprised of a first electron blocking layer.

In some embodiments, the first electron blocking layer material and the second electron blocking layer host material in the organic electroluminescent device are the same material.

In yet another aspect, the present invention provides an organic light emitting device comprising the above organic electroluminescent device.

In still another aspect, the present invention provides a method of preparing an organic electroluminescent device, comprising the steps of:

s1: forming an anode;

s2: forming an electron blocking layer comprising:

s21: co-evaporating the second electron blocking layer host material and the second electron blocking layer guest material to form a second electron blocking layer; and

s22: evaporating the first electron blocking layer material to form a first electron blocking layer;

s3: forming a light-emitting layer; and

s4: forming a cathode.

The invention has the following beneficial effects:

the invention provides a novel device structure, which is characterized in that an electron blocking layer is arranged to comprise a first electron blocking layer and a second electron blocking layer, wherein the first electron blocking layer is made of a first electron blocking layer material, and the second electron blocking layer comprises a second electron blocking layer host material and a second electron blocking layer guest material, so that a light emitting layer is not in direct contact with a layer doped with a p-type dopant, the occurrence of the problem of crosstalk of the device is reduced on the basis of improving hole transmission capability, and quenching caused by introduction of the p-type dopant is avoided.

Drawings

Fig. 1 shows a schematic structure of an organic electroluminescent device according to an embodiment of the present invention;

fig. 2 shows a schematic structural view of an organic electroluminescent device according to an embodiment of the present invention;

fig. 3 shows a schematic structural view of an organic electroluminescent device according to an embodiment of the present invention;

fig. 4 shows a schematic structural view of an organic electroluminescent device according to an embodiment of the present invention;

fig. 5 shows a schematic structural view of an organic electroluminescent device according to an embodiment of the present invention;

fig. 6 shows a schematic structural view of an organic electroluminescent device according to an embodiment of the present invention.

The reference numerals have the following meanings:

100: an organic electroluminescent device 1;

101: a cathode;

102: an anode;

200: an organic electroluminescent device 2;

201: a cathode;

202: an anode;

210: a first light emitting region;

220: a second light emitting region;

230: a third light emitting region;

300: an organic electroluminescent device 3;

301: a cathode;

302: an anode;

310: a first light emitting region;

320: a second light emitting region;

330: a third light emitting region;

400: an organic electroluminescent device 4;

401: a cathode;

402: an anode;

410: a first light emitting region;

420: a second light emitting region;

430: a third light emitting region;

500: an organic electroluminescent device 5;

501: a cathode;

502: an anode;

510: a first light emitting region;

520: a second light emitting region;

600: an organic electroluminescent device 6;

601: a cathode;

602: an anode;

610: a first light emitting region;

620: a second light emitting region;

630: a third light emitting region;

EIL: an electron injection layer;

ETL: an electron transport layer;

EML: a light emitting layer;

EBL1: a first electron blocking layer;

EBL2: a second electron blocking layer;

HTL: a hole transport layer;

HIL: a hole injection layer;

HBL: a hole blocking layer;

r EML: a red light pixel light emitting layer;

g EML: a green pixel light emitting layer;

b EML: a blue light pixel light emitting layer;

y EML: and a yellow pixel light emitting layer.

Detailed Description

The present invention will be described in further detail below in order to make the objects, technical solutions and advantages of the present invention more apparent. The matters set forth in the various aspects and embodiments are not limited to the relevant parts but may be combined in any suitable manner without contradiction.

In this specification, terms such as "upper", "lower", "left", "right", "inner", "outer", and the like, which indicate an azimuth or a positional relationship, are used for the purpose of describing the present invention only, for example, in order to describe the relationship between the components of the device in correspondence with the drawings, but should not be construed to limit the present invention in any way, i.e., it should not be construed as being limited to only the specific positions or the positional relationships described. The drawings are for illustrative purposes only and are not intended to limit the scope of the present invention in any way in terms of the dimensions, proportions, positional relationships, etc. shown.

In the present specification, the following terms have the following meanings, unless otherwise indicated:

in the present invention, the expression of Ca to Cb means that the group has a carbon number of a to b, and generally the carbon number does not include the carbon number of the substituent unless otherwise specified. In the present invention, the expression of chemical elements includes the concept of isotopes of the same chemical nature, for example, the expression of "hydrogen", and also includes the concept of "deuterium", "tritium" of the same chemical nature. In the present invention, "deuterium" may be represented by "D".

In the present specification, "substituted or unsubstituted" means substituted with one or more substituents selected from halogen, cyano, hydroxy, C1-C12 alkyl, C1-C12 alkoxy, C6-C12 aryl, C3-C12 heteroaryl, preferably fluorine, cyano, methoxy, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, phenyl, biphenyl, naphthyl, phenanthryl, fluorenyl, dibenzofuranyl, dibenzothiophenyl, pyridyl, quinolinyl, phenylpyridyl, pyridylphenyl and the like.

In the present specification, the alkyl group may be linear or branched, and includes cycloalkyl groups, and the number of carbon atoms is not particularly limited, but is preferably 1 to 12. Specific examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, decyl, and the like.

In the present specification, the aryl group is not particularly limited, but preferably has 6 to 30 carbon atoms. Specific examples of aryl groups include phenyl, biphenyl, naphthyl, anthryl, phenanthryl, and the like. In this specification, a heteroaryl group is a heteroaryl group containing one or more heteroatoms in O, N, S, si, and the number of carbon atoms is preferably 3 to 30. Specific examples of heteroaryl groups include thienyl, furyl, pyrrolyl, imidazolyl, thiazolyl, oxazolyl, and the like. Wherein both aryl and heteroaryl groups comprise fused ring groups.

In the present specification, the expression "the ring structure" indicates that the linking site is located at any position on the ring structure capable of bonding.

The following describes various aspects of the present invention.

The invention provides an organic electroluminescent device, which comprises one or more light emitting areas, wherein each light emitting area sequentially comprises a cathode, a light emitting layer, an electron blocking layer and an anode, the electron blocking layer comprises a first electron blocking layer, the electron blocking layer of at least one light emitting area further comprises a second electron blocking layer positioned between the anode and the first electron blocking layer, the first electron blocking layer is composed of a first electron blocking layer material, and the second electron blocking layer comprises a second electron blocking layer host material and a second electron blocking layer guest material.

Fig. 1 shows an organic electroluminescent device 100 according to an embodiment of the present application, which includes a cathode 101 and an anode 102, and further includes an Electron Injection Layer (EIL), an Electron Transport Layer (ETL), an emission layer (EML), a first electron blocking layer (EBL 1), a second electron blocking layer (EBL 2), a Hole Transport Layer (HTL), and a Hole Injection Layer (HIL) in a direction from the cathode 101 to the anode 102.

The cathode and anode may be formed by sputtering or depositing a material serving as an electrode on the substrate. The substrate is generally a glass or polymer material having excellent mechanical strength, thermal stability, water repellency, and transparency. A Thin Film Transistor (TFT) may be provided on a substrate for a display. As the anode, indium Tin Oxide (ITO), indium Zinc Oxide (IZO), tin dioxide (SnO) ₂ ) An oxide transparent conductive material such as zinc oxide (ZnO), and any combination thereof. As the cathode, metals or alloys such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), and the like, and any combination thereof can be used.

The electron blocking layer of at least one light emitting area in the organic electroluminescent device is provided with at least two layers, namely a first electron blocking layer and a second electron blocking layer in the direction from a cathode to an anode, wherein the first electron blocking layer is made of a first electron blocking layer material, the second electron blocking layer comprises a second electron blocking layer main material and a second electron blocking layer guest material, namely, the first electron blocking layer is made of a single material, and the second electron blocking layer comprises at least two materials, so that the combined effect not only ensures the improvement of the efficiency of the device, but also reduces the quenching probability of the device.

The electron blocking layer may be formed by vacuum thermal evaporation, spin coating, printing, or the like. For example, the first electron blocking layer may be formed by vacuum thermal evaporation, spin coating, printing of the first electron blocking layer material. The second electron blocking layer is formed by co-evaporating, spin-coating or printing the second electron blocking layer host material with the second electron blocking layer guest material, for example, may be formed by vacuum multi-source co-evaporation. The ratio between the second electron blocking layer host material and the second electron blocking layer guest material in the second electron blocking layer can be adjusted by controlling the evaporation rates of the two materials.

Satisfying the above energy level relationship can ensure a small energy level barrier between the host material and the guest material.

In some embodiments, the first electron blocking layer has a thickness of 40-60nm and the second electron blocking layer has a thickness of 60-100nm in an organic electroluminescent device.

The light-emitting layer comprises a light-emitting material. The light emitting layer includes a light emitting material (i.e., dopant) that can emit different wavelength spectrums, and may also include a Host material (Host) at the same time.

According to different technologies, the luminescent layer material can be made of different materials such as fluorescent electroluminescent material, phosphorescent electroluminescent material, thermal activation delayed fluorescence luminescent material and the like. In an OLED device, a single light emitting technology may be used, or a combination of different light emitting technologies may be used. The different luminescent materials classified by the technology can emit light of the same color, and can also emit light of different colors.

In some embodiments, the light emitting layer employs fluorescence electroluminescence technology. The luminescent layer fluorescent host material thereof may be selected from, but is not limited to, one or more combinations of BFH-1 through BFH-16 listed below.

In some embodiments, the light emitting layer employs fluorescence electroluminescence technology. The luminescent layer fluorescent dopant thereof may be selected from, but is not limited to, one or more combinations of BFD-1 through BFD-12 listed below.

In one aspect of the invention, the light-emitting layer employs phosphorescent electroluminescence technology. The luminescent layer host material is selected from, but not limited to, one or more of GPH-1 to GPH-80.

In one aspect of the invention, the light-emitting layer employs phosphorescent electroluminescence technology. The luminescent layer phosphorescent dopant thereof may be selected from, but is not limited to, one or more combinations of GPD-1 to GPD-47 listed below.

/>

In one aspect of the present invention, the luminescent layer employs phosphorescence electroluminescent technology, wherein the luminescent layer host material is selected from, but not limited to, one or more of RH-1 to RH-31.

In one aspect of the invention, the light-emitting layer employs phosphorescent electroluminescence technology. The luminescent layer phosphorescent dopant thereof may be selected from, but is not limited to, one or more combinations of the RPD-1 through RPD-28 listed below.

In one aspect of the invention, the light-emitting layer employs phosphorescent electroluminescence technology. The luminescent layer phosphorescent dopant may be selected from, but is not limited to, one or more combinations of YPD-1-YPD-11 listed below.

In some embodiments, the first electron blocking layer material is the same as the second electron blocking layer host material in the organic electroluminescent device, and the material has a hole mobility of not less than 3.0X10 ^-5 cm ² Vs and satisfies |lumo _{Luminescent host material} ︱－︱LUMO _{Second electron blocking layer main material} And (2) is not less than 0.5, and the triplet state energy level of the second electron blocking layer host material is higher than that of the light-emitting host material.

In other embodiments, the first electron blocking layer material is different from the second electron blocking layer host material, and the mobility of the first electron blocking layer material is not less than 8.0X10 ^-5 cm ² Vs and satisfies% _{Luminescent host material} ︱＞︱HOMO _{First electron blocking layer material} ︱＞︱HOMO _{Second electron blocking layer main material} And (3). Meeting the condition can ensure that the potential barrier energy level between the luminescent material and the barrier layer material is in a decreasing trend, and the gap between potential barriers is reduced.

In some embodiments, the first electron blocking layer is the same for each light emitting region in the organic electroluminescent device. For example, the first electron blocking layer is the same in material and thickness. When the first electronic layers are made of the same material and have the same thickness, the number of production steps can be reduced, i.e., evaporation can be completed by using one OPEN MASK.

The light emitting layer may be a single color light emitting layer emitting a single color of red, green, blue, yellow, or the like. The plurality of monochromatic light emitting layers with different colors can be arranged in a plane according to the pixel pattern, or can be stacked together to form a color light emitting layer. When the light emitting layers of different colors are stacked together, they may be spaced apart from each other or may be connected to each other. The light emitting layer may be a single color light emitting layer capable of simultaneously emitting different colors of red, green, blue, yellow, etc.

Since the optical coupling thicknesses (films) corresponding to the different colors of light are different, the red light is thickest and the blue light is thinnest, the thicknesses of the second electron blocking layers in the light emitting areas of the different colors are different.

In some embodiments, the thickness of the second electron blocking layer in the red light emitting region is 80 to 100nm, the thickness of the second electron blocking layer in the green light emitting region is 60 to 80nm, and the thickness of the second electron blocking layer in the yellow light emitting region is 70 to 90nm in the organic electroluminescent device.

In some embodiments, at least one light emitting region in the organic electroluminescent device is a blue light emitting region, the electron blocking layer of which does not include a second electron blocking layer.

Fig. 2 shows an organic electroluminescent device 200 according to an embodiment of the present application, which includes 3 light emitting regions, namely, a blue light region 210, a red light region 220 and a green light region 230, respectively, the light emitting device including a cathode 201 and an anode 202, and further including an emitting layer (EML), a first electron blocking layer (EBL 1) and a second electron blocking layer (EBL 2) in a direction from the cathode 201 to the anode 202, wherein the blue light region 210 includes only the first electron blocking layer (EBL 1) and does not include the second electron blocking layer (EBL 2), and the red light region 220 and the green light region 230 each include the first electron blocking layer (EBL 1) and the second electron blocking layer (EBL 2), respectively.

Fig. 3 shows an organic electroluminescent device 300 according to an embodiment of the present application, which includes 3 light emitting regions, namely, a blue light region 310, a red light region 320 and a green light region 330, the light emitting device including a cathode 301 and an anode 302, and further including an emitting layer (EML), a first electron blocking layer (EBL 1) and a second electron blocking layer (EBL 2) in a direction from the cathode 301 to the anode 302, wherein the blue light region 310 and the green light region 330 include only the first electron blocking layer (EBL 1) and not the second electron blocking layer (EBL 2), and the red light region 320 includes the first electron blocking layer (EBL 1) and the second electron blocking layer (EBL 2).

Fig. 4 shows an organic electroluminescent device 400 according to an embodiment of the present application, which includes 3 light emitting regions, namely, a blue light region 410, a red light region 420 and a green light region 430, and includes a cathode 401 and an anode 402, and further includes an emitting layer (EML), a first electron blocking layer (EBL 1) and a second electron blocking layer (EBL 2) in a direction from the cathode 401 to the anode 402, wherein the blue light region 410 and the red light region 420 include only the first electron blocking layer (EBL 1) and not the second electron blocking layer (EBL 2), and the green light region 430 includes the first electron blocking layer (EBL 1) and the second electron blocking layer (EBL 2).

Fig. 5 shows an organic electroluminescent device 500 according to an embodiment of the present application, comprising 2 light emitting regions, a blue light region 510 and a yellow light region 420, respectively, the light emitting device comprising a cathode 501 and an anode 502, and further comprising a light emitting layer (EML), a first electron blocking layer (EBL 1) and a second electron blocking layer (EBL 2) in a direction from the cathode 501 to the anode 502, wherein the blue light region 510 comprises only the first electron blocking layer (EBL 1) and not the second electron blocking layer (EBL 2), and the yellow light region 520 comprises the first electron blocking layer (EBL 1) and the second electron blocking layer (EBL 2).

Fig. 6 shows an organic electroluminescent device 600 according to an embodiment of the present application, which includes 3 light emitting regions, namely, a blue light region 610, a red light region 620 and a green light region 630, and includes a cathode 601 and an anode 602, and further includes an Electron Transport Layer (ETL), a Hole Blocking Layer (HBL), an emission layer (EML), a first electron blocking layer (EBL 1), a second electron blocking layer (EBL 2), a Hole Transport Layer (HTL) and a Hole Injection Layer (HIL) in a direction from the cathode 601 to the anode 602. Wherein the blue region 610 includes only the first electron blocking layer (EBL 1) and does not include the second electron blocking layer (EBL 2), and the red region 620 and the green region 630 each include the first electron blocking layer (EBL 1) and the second electron blocking layer (EBL 2), respectively.

In some embodiments, the first electron blocking layer material and/or the second electron blocking layer host material is selected from the group consisting of compounds represented by the following general formula (I),

wherein L independently represents a single bond, a substituted or unsubstituted C6-C30 arylene group or a substituted or unsubstituted C3-C30 heteroarylene group, and examples of the C6-C30 arylene group include phenyl, biphenylene, terphenylene, naphthylene, anthrylene, phenanthrylene, fluorenylene, pyrenylene, and biphenyleneBase, fluororenylene and benzo [ a ]]Anthracenyl, benzo [ c ]]Phenanthryl, triphenylene, benzo [ k ]]Fluorescent anthracenyl, benzo [ g ]]/>Benzo [ b ] base]Triphenylene, picene, perylene, and the like, among which phenylene, naphthylene, biphenylene, and the like are preferable, and phenylene is more preferable.

R ^a 、R ^b The same or different groups are each independently selected from C1-C20 alkyl, C1-C20 alkenyl, and C1-C20 alkynyl, and examples of these groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, n-pentyl, sec-pentyl, cyclopentyl, neopentyl, n-hexyl, cyclohexyl, neohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, and 2-ethylhexyl Trifluoromethyl, pentafluoroethyl, 2-trifluoroethyl, ethenyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl, ethynyl, propynyl, butynyl, pentynyl, hexynyl or octynyl, R ^a And R is ^b More preferably C1-C12 alkyl, and examples of the C1-C12 alkyl group include: methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, pentyl, isopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl and the like are preferred, with methyl, ethyl, n-propyl, isopropyl, wherein R ^a 、R ^b More preferably methyl.

R ^a 、R ^b May be linked to form a ring structure, may be linked to form a ring, and such a ring is preferably a five-membered ring and a six-membered ring, and may be, for example, a cyclohexane ring, cyclopentane, a cyclic structure formed by linking 2, 2-biphenylene groups (a spirofluorene structure formed by screwing at the X position).

R is selected from the group consisting of C1-C20 alkyl, C1-C20 alkenyl, C1-C20 alkynyl, C1-C20 alkoxy, C6-C30 aryl, C3-C30 heteroaryl, more preferably C1-C12 alkyl, C6-C30 aryl, C3-C30 heteroaryl.

Examples of the C1-C12 alkyl group include the same examples as described above, and examples of the C6-C30 aryl group include: phenyl, biphenyl, terphenyl, naphthyl, anthryl, phenanthryl, fluorenyl, pyrenyl, and the like,Radical, fluoranthenyl radical and benzo [ a ]]Anthracenyl and benzo [ c ]]Phenanthryl, triphenylene, benzo [ k ]]Fluorescent anthracenyl and benzo [ g ]]/>Radical, benzo [ b ]]Triphenylene, picene, perylene, etc., with phenyl, naphthyl, more preferably phenyl; specific examples of the C3-C30 heteroaryl group include: pyridyl, pyrimidinyl, pyrazinyl, pyridazinyl, triazinyl, quinolinyl, isoquinolinyl, naphthyridinyl,Phthalazinyl, quinoxalinyl, quinazolinyl, phenanthridinyl, acridinyl, phenanthrolinyl, pyrrolyl, imidazolyl, pyrazolyl, triazolyl, tetrazolyl, indolyl, benzimidazolyl, indazolyl, imidazopyridinyl, benzotriazolyl, carbazolyl, furanyl, thienyl, oxazolyl, thiazolyl, isoxazolyl, isothiazolyl, oxadiazolyl, thiadiazolyl, benzofuranyl, benzothienyl, benzoxazolyl, benzothiazolyl, benzisoxazolyl, benzisothiazolyl, benzoxadiazolyl, benzothiadiazolyl, dibenzofuranyl, dibenzothiophenyl, piperidinyl, pyrrolidinyl, piperazinyl, morpholinyl, phenazinyl, phenothiazinyl, phenoxazinyl, and the like, but are not limited thereto.

Preferred groups for R may also be exemplified by: benzene, naphthalene, anthracene, benzanthracene, phenanthrene, benzophenanthrene, pyrene, hole, perylene, fluoranthene, naphthacene, pentacene, benzopyrene, biphenyl, benzine, terphenyl, triphenylene, tetraphenyl, fluorene, benzopyrene, triphenylene, tetraphenyl, triphenylene spirobifluorene, dihydrophenanthrene, dihydropyrene, tetrahydropyrene, cis-or trans-indenofluorene, trimeric indene, heterotrimeric indene, spirotrimeric indene, spiroheterotrimeric indene, furan, coumarone, isobenzofuran, dibenzofuran, thiophene, benzothiophene, isobenzothiophene, dibenzothiophene, pyrrole, indole, isoindole, carbazole, indolocarbazole, indenocarbazole, pyridine, quinoline, isoquinoline, acridine, phenanthridine, benzo-5, 6-quinoline, benzo-6, 7-quinoline, benzo-7, 8-quinoline, phenothiazine, phenoxazine, pyrazole, indazole, imidazole, benzimidazole, naphthazole, phenanthroimidazole, indenocarbazole, pyridine, quinoline, isoquinoline, acridine, phenanthridine, benzo-5, 6-quinoline, benzo-6, 7-quinoline, benzo-7, 8-quinoline, phenothiazine, phenoxazine, pyrazole, indazole, imidazole, benzimidazole, and the like pyridine imidazole, pyrazine imidazole, quinoxaline imidazole, thiophene, benzoxazole, naphthazole, anthracene, phenanthrene, isoxazole, 1, 2-thiazole, 1, 3-thiazole, benzothiazole, pyridazine, benzopyridazine, pyrimidine, benzopyrimidine, quinoxaline, 1, 5-diazaanthracene, 2, 7-diazapyrene, 2, 3-diazapyrene, 1, 6-diazapyrene, 1, 8-diazapyrene, 4,5,9, 10-tetrazole, pyrazine, phenazine, phenoxazine, phenothiazine, fluorored ring, naphthyridine, azacarbazole, benzocarboline, phenanthroline, 1,2, 3-triazole, 1,2, 4-triazole, benzotriazole, 1,2, 3-oxadiazole, 1,2, 4-oxadiazole, 1,2, 5-diazole, 1, 3-diazole, 1,2, 4-diazole, 1,2, 3-diazole, 1,2, 4-diazole, 2-diazole 1,3, 5-triazine, 1,2, 4-triazine, 1,2, 3-triazine, tetrazole, 1,2,4, 5-tetrazine, 1,2,3, 4-tetrazine, 1,2,3, 5-tetrazine, purine, pteridine, indolizine, and benzothiadiazole, or a combination thereof. More preferred groups for R are phenyl or naphthyl.

p is an integer of 0 to 7, preferably 0 or 1.

Ar in the general formula is selected from a substituted or unsubstituted C6-C30 aryl group or a substituted or unsubstituted C3-C30 heteroaryl group, in particular, a substituted or unsubstituted C6-C30 aryl group or a heteroaryl group represented by the general formula (A),

in the formula (A), L ¹ Independently represents a single bond, a substituted or unsubstituted C6-C30 arylene group or a substituted or unsubstituted C3-C30 heteroarylene group, "" represents a linking site to a parent nucleus, R ¹ Selected from the group consisting of C1-C20 alkyl, C1-C20 alkenyl, C1-C20 alkynyl, C1-C20 alkoxy, C6-C30 aryl, C3-C30 heteroaryl, and a plurality of R ¹ Q is an integer from 0 to 7, preferably 0 or 1, two R's in adjacent positions, identical or different ¹ May be linked to form a ring, such a ring may be aliphatic or aromatic, e.g. R in adjacent positions ¹ Can be connected to form a benzene ring, a fluorene ring and other ring structures.

X is selected from O, S, NR ² 、SiR ³ R ⁴ Preferably NR ² 、O、S；R ² 、R ³ 、R ⁴ Each independently selected from C1-C12 alkyl, substituted or unsubstituted C6-C30 aryl or substituted or unsubstituted C3-C30 heteroaryl, R ³ And R is ⁴ May be interconnected to form a ring.

Examples of the substituted or unsubstituted aryl group having 6 to 30 carbon atoms include: naphthyl, phenanthryl, benzophenyl, fluoranthenyl, anthryl, pyrene, dihydropyrene, fennel, perylene, fluoranthene, benzanthracene, benzophenanthrene, naphthacene, pentacene, benzopyrene, furan, benzofuran, isobenzofuran, thiophene, benzothiophene, isophene, pyridine, quinoline, isoquinoline, acridine, phenanthridine, benzo-5, 6-quinoline, benzo-6, 7-quinoline, benzo-7, 8-quinoline, phenothiazine, phenazine, pyrazole, indazole, imidazole, benzimidazole, naphthyridine, phenanthroimidazole, pyridoimidazole, pyrazinoimidazole, quinoxalinoimidazole, enozole, benzoxazole, naphthyzole, anthracenyl oxazole, phenanthroimidazole isoxazoles, 1, 2-thiazoles, 1, 3-thiazoles, benzothiazoles, pyridazines, benzopyridazines, pyrimidines, benzopyrimidines, quinoxalines, pyrazines, phenazines, naphthyridines, azacarbazoles, benzocarbolines, phenanthrolines, 1,2, 3-triazoles, 1,2, 4-triazoles, benzotriazoles, 1,2, 3-oxadiazoles, 1,2, 4-oxadiazoles, 1,2, 5-oxadiazoles, 1,3, 4-oxadiazoles, 1,2, 3-thiadiazoles, 1,2, 4-thiadiazoles, 1,2, 5-thiadiazoles, 1,3, 4-thiadiazoles, 1,3, 5-triazines, 1,2, 3-triazines, tetrazoles, 1,2,4, 5-tetrazines, 1,2,3, 4-tetrazines, 1,2,3, 5-tetrazines, purines, naphthyridines, and benzothiadiazoles or combinations of these groups, these groups may have corresponding substituents.

The above "substituted or unsubstituted" means substituted with one or more substituents selected from halogen, C ₁ ～C ₁₂ Alkyl, C of (2) ₁ ～C ₁₂ Alkoxy, C ₆ ～C ₁₂ Aryl, C of (2) ₃ ～C ₁₂ Substituted by substituents in heteroaryl, cyano, hydroxy, the bond "-" of the substituent being drawn through the representation of the ring structure to indicate that the attachment site is at any position on the ring structure capable of bonding.

C as described above ₁ ～C ₁₂ Alkyl, C of (2) ₆ ～C ₁₂ Aryl, C of (2) ₃ ～C ₁₂ Examples of heteroaryl groups of (C1-C12 alkoxy) include those obtained by linking the C1-C12 alkyl group with-O-such as methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy and the like, and among them, methoxy, ethoxy, propoxy and more preferably methoxy groups are preferable.

For the above compound, the main structure of the mother nucleus of fluorene and 2, 4-diphenylaniline is that of the compound, and the compound can be ensured to have good hole transport performance or electron blocking performance through the defined substituent group with a special structure. It is presumed that the high steric hindrance of 2, 4-diphenyl benzene directly affects the charge transport property of the compound, so that charge is more smoothly transferred in molecules, and the high steric hindrance is also likely to make self-assembly property during film formation more favorable for charge transport between molecules.

On the other hand, the 2, 4-position of aniline in the mother nucleus is replaced, so that the thermal stability of molecules can be improved, the possibility of oxidation of the molecules is reduced, the service life of a device is prolonged, meanwhile, the introduction of 2-position substituents can increase the steric hindrance between the molecules, thereby preventing the molecules from clustering, facilitating film formation during vapor deposition, reducing potential energy between contact interfaces of film layers, and facilitating charge transfer. Thus, the charge transfer efficiency can be improved from various aspects, and the service life can be prolonged.

In particular, the compound of formula (I) is selected from the following compounds:

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in some embodiments, the second electron blocking layer host material is selected from compounds of formula (I). In other embodiments, the first electron blocking layer material is selected from compounds of formula (I).

In particular, the first electron blocking layer material and the second electron blocking layer host material are both selected from compounds of formula (I).

The first electron blocking layer material and the second electron blocking layer host material may also be materials that generally function as hole transport regions. For example, the compounds illustrated by HT-1 through HT-34 described below may also be used as the first electron blocking layer material and/or the second electron blocking layer host material.

The second electron blocking layer guest material in the organic electroluminescent device may be selected from HI-1 to HI-3.

In some embodiments, the organic electroluminescent device further comprises one or more of an electron injection layer, an electron transport layer, a hole blocking layer, a hole transport layer, a hole injection layer. The organic material layer may be formed on the electrode by vacuum thermal evaporation, spin coating, printing, or the like. The compounds used as the organic material layer may be small organic molecules, large organic molecules and polymers, and combinations thereof.

The hole transport region is located between the anode and the light emitting layer. The hole transport region may be a Hole Transport Layer (HTL) of a single layer structure including a single layer hole transport layer containing only one compound and a single layer hole transport layer containing a plurality of compounds. The hole transport region may have a multilayer structure including at least one of a Hole Injection Layer (HIL), a Hole Transport Layer (HTL), and an Electron Blocking Layer (EBL).

The material of the hole transport region may be selected from, but is not limited to, phthalocyanine derivatives such as CuPc, conductive polymers or conductive dopant containing polymers such as polystyrene, polyaniline/dodecylbenzenesulfonic acid (Pani/DBSA), poly (3, 4-ethylenedioxythiophene)/poly (4-styrenesulfonate) (PEDOT/PSS), polyaniline/camphorsulfonic acid (Pani/CSA), polyaniline/poly (4-styrenesulfonate) (Pani/PSS), aromatic amine derivatives such as the compounds shown below HT-1 to HT-34; or any combination thereof.

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The hole injection layer is located between the anode and the hole transport layer. The hole injection layer may be a single compound material or a combination of a plurality of compounds. For example, the hole injection layer may employ one or more of the compounds HT-1 through HT-34 described above, or one or more of the compounds HI-1 through HI-3 described below; one or more of the following HI-1 to HI-3 may also be doped with one or more of the compounds HT-1 to HT-34:

the OLED organic material layer may further include an electron transport region between the light emitting layer and the cathode. The electron transport region may be an Electron Transport Layer (ETL) of a single layer structure including a single layer electron transport layer containing only one compound and a single layer electron transport layer containing a plurality of compounds. The electron transport region may also be a multilayer structure including at least one of an Electron Injection Layer (EIL), an Electron Transport Layer (ETL), and a Hole Blocking Layer (HBL).

In some embodiments, the electron transport layer material may be selected from, but is not limited to, combinations of one or more of ET-1 through ET-57 listed below.

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The device may further include an electron injection layer between the electron transport layer and the cathode, the electron injection layer material including, but not limited to, a combination of one or more of the following: liF, naCl, csF, li ₂ O、Cs ₂ CO ₃ 、BaO、Na、Li、Ca。

In yet another aspect, there is also provided a method of preparing an organic electroluminescent device as described herein, comprising the steps of:

s1: forming an anode;

s2: forming an electron blocking layer comprising:

s21: co-evaporating, spin-coating or printing the second electron blocking layer host material and the second electron blocking layer guest material to form a second electron blocking layer; and

s22: evaporating, spin-coating or printing the first electron blocking layer material to form a first electron blocking layer;

s3: forming a light-emitting layer; and

s4: forming a cathode.

In some embodiments, the evaporation rate ratio of the second electron blocking layer host material to the second electron blocking layer guest material in step S21 is 1:0.01 to 1:0.09.

The evaporation is carried out under vacuum condition, and the vacuum degree is generally pumped to 1 multiplied by 10 ^-5 ～9×10 ^-3 Pa, vapor deposition is performed. The evaporation rate is generally 0.01nm/s to 2.0nm/s, for example, about 0.1 nm/s.

One or more of the light emitting layer, the electron injection layer, the electron transport layer, the hole blocking layer, the hole transport layer, and the hole injection layer may be formed by vacuum thermal evaporation, spin coating, printing, or the like.

In some embodiments, the electron blocking layer, the light emitting layer, the electron injection layer, the electron transport layer, the hole blocking layer, the hole transport layer, and the hole injection layer are all formed by vacuum thermal evaporation.

The organic electroluminescent device comprising a plurality of light emitting areas comprises a plurality of pixel units distributed in an array, as shown in the legend, each pixel unit comprises one or more of a red light pixel unit, a green light pixel unit, a blue light pixel unit and a yellow light pixel unit, and each pixel unit comprises a common layer which is stacked: one or more layers of a cathode layer, an electron injection layer, an electron transport layer, a hole blocking layer, an electron blocking layer, a hole transport layer, a hole injection layer and an anode layer. The common layer in the different light emitting regions may be the same or different, for example, the cathode layer, the electron injection layer, the electron transport layer, the hole blocking layer, the hole transport layer, the hole injection layer, the anode layer may be the same, thereby simplifying the manufacturing process, and the light emitting layer and the electron blocking layer may be different, as shown in fig. 2 to 6.

Examples

In order that those skilled in the art will better understand the present invention, the present invention will be described in further detail with reference to specific embodiments.

All compounds of the synthesis process not mentioned in the examples are commercially available starting products. Various chemicals used in the examples, such as petroleum ether, ethyl acetate, toluene, tetrahydrofuran, N-dimethylformamide, methylene chloride, cesium carbonate, potassium carbonate, palladium acetate, 2-dicyclohexylphosphorus-2, 4, 6-triisopropylbiphenyl (XPhos), 2-dicyclohexylphosphine-2 ',6' -dimethoxybiphenyl (SPhos), tetrakis (triphenylphosphine) palladium, bis (4-biphenylyl) amine, carbazole, 1-bromo-3-chloro-5-fluorobenzene, 4-biphenylboric acid, sodium t-butoxide, and the like, can be commercially available as basic chemical raw materials in domestic chemical products.

Analytical testing of intermediates and compounds in the present invention used an absiex mass spectrometer (4000 QTRAP) and a bruk nuclear magnetic resonance (400M).

The present invention will be described more specifically with reference to the following examples, but the present invention is not limited to these examples. The compound represented by the general formula (1) is synthesized by using 2, 4-dibromoaniline and phenylboric acid to react through Suzuki to obtain an intermediate 2, 4-diphenylaniline, then reacting with 2-bromo-9, 9-dimethylfluorene to obtain an intermediate A-1, and then using a halide and the intermediate A-1 to synthesize a product through Buchwald-Hartwig coupling reaction.

A representative synthetic route for the compounds of the general formula of the present invention is as follows:

synthesis of intermediate A-2

Intermediate A-2 can be used for the synthesis of compounds of the general formula (I-1), compounds of the general formula (I-2) can likewise be obtained on the basis of the same principle, and other homologs can also be obtained on the basis of analogous synthetic methods.

Synthesis of A-1:

in a four-necked flask equipped with a condenser, 2, 4-dibromoaniline (50 g, 199 mmol) as a raw material, phenylboronic acid (54 g, 438 mmol), potassium carbonate (83 g, 598 mmol) were added to a mixed solvent of Tetrahydrofuran (THF) (600 mL) and water (300 mL), stirred uniformly, and then Pd (PPh) was added under nitrogen protection ₃ ) ₄ (9.2 g,7.97 mmol) was heated to 70℃and reacted for 18h. After cooling to room temperature, 500mL of water was directly added, the aqueous phase was extracted twice with 300mL of ethyl acetate, the organic phases were combined, dried over anhydrous sodium sulfate, and concentrated to give a crude product. Purifying the crude product by column chromatography (PE/EA, 5/1) to obtain light yellow powder 38g;

synthesis of A-2:

into a four-necked flask equipped with a condenser, A-1 (38 g, 135 mmol), 2-bromo-9, 9-dimethylfluorene ((41 g, 148 mmol), sodium t-butoxide (32.4 g,337 mmol), toluene (500 mL) and Pd (dppf) Cl under nitrogen were added ₂ (1.5 g,2.02 mmol) and SPhos (1.7 g,4.05 mmol), the reaction solution was heated to 100deg.C and reacted for 18h. After cooling to room temperature, 250mL of saturated aqueous salt solution was directly added, the aqueous phase was extracted three times with 200mL of ethyl acetate, the organic phases were combined, dried over anhydrous sodium sulfate, and concentrated to obtain a crude product. The crude product was purified by column chromatography on silica gel (PE/EA, 10/1) to give 45g of a pale yellow solid.

General synthetic method of Compounds of general formula (I)

Synthesis example 1

Synthesis of Compound-1

Synthesis of intermediate M1

In a four-necked flask equipped with a condenser, a starting material of dibenzothiophene 4-borate (40 g, 175 mmol), bromobenzene (33 g, 211 mmol), and potassium carbonate (36 g, 263 mmol) were added Adding into a mixed solvent of toluene (500 mL) and ethanol (100 mL), water (100 mL), stirring, adding Pd (PPh) under nitrogen protection ₃ ) ₄ (4.1 g,3.51 mmol) was heated to 100deg.C and reacted for 18h. After cooling to room temperature, 300mL of saturated aqueous salt solution was directly added, the aqueous phase was extracted twice with 300mL of ethyl acetate, the organic phases were combined, dried over anhydrous sodium sulfate, and concentrated to give a crude product. The crude product was purified by column chromatography over silica gel (PE/DCM, 20/1) to give 30g of a white powder;

synthesis of intermediate M2

Thoroughly dried compound M1 (20 g,76.8 mmol) was added to a dry three-necked flask equipped with a constant pressure dropping funnel, a low temperature thermometer. Anhydrous tetrahydrofuran (300 mL) was added, the compound was dissolved with stirring, and then the reaction system was cooled to-78 ℃ by a liquid nitrogen-ethanol bath under nitrogen protection. Then, s-BuLi (71 mL,1.3M,92.2 mmol) was added dropwise through a constant pressure dropping funnel, and the dropping speed was controlled so that the temperature of the reaction system was kept at-60 to-70℃and the mixture was kept at that temperature for 30 minutes after the completion of the dropping to give a purplish red solution. 1, 2-dibromoethane (18.8 g,99.9 mmol) was dissolved in THF (100 mL), and the solution was added dropwise to the above solution, and after the addition of the solvent, the solution was gradually yellow, and after the addition of the solvent, the temperature was naturally raised to room temperature and stirred for 4 hours. The reaction system was poured into 300mL of saturated brine, extracted twice with ethyl acetate (200 mL), the organic phases were combined, dried over anhydrous sodium sulfate, and concentrated to a solid, which was stirred with petroleum ether for 30min to give a white solid (18 g).

Synthesis of intermediate M3

In a four-necked flask equipped with a condenser, M2 (17 g, 50 mmol), p-chlorophenylboronic acid (9.4 g, 60 mmol), potassium carbonate (10.4 g, 75.2 mmol) were added to a mixed solvent of toluene (200 mL) and ethanol (50 mL), water (50 mL), stirred uniformly, and Pd (PPh) was then added under nitrogen ₃ ) ₄ (0.6 g,0.5 mmol) was heated to 100deg.C and reacted for 18h. After cooling to room temperature, 300mL of saturated aqueous salt solution was directly added, the aqueous phase was extracted twice with 300mL of ethyl acetate, the organic phases were combined, dried over anhydrous sodium sulfate and concentrated to give a brown oil. The crude product was purified by column chromatography over silica gel (PE/DCM, 20/1) to give 10g of a white powder;

synthesis of Compound-1

Intermediate A-2 (10 g,22.8 mmol), M3 (10.2 g,27.4 mmol), sodium t-butoxide (2.9 g,29.7 mmol) were placed in a three-necked flask, 100mL toluene solvent was added and stirred well, and catalyst Pd2 (dba) 3 (209 mg,0.228 mmol) and SPhos (188 mg,0.457 mmol) were added under nitrogen protection. The temperature was raised to 110℃and the solution developed a reddish brown color, and the reaction was incubated overnight. After cooling, poured into 200mL of water, extracted with EA (200 mL x 2), the organic phases were combined, dried over sodium sulphate, concentrated to a brown oil, the crude purified PE/DCM, 5/1) by column chromatography, concentrated to a pale yellow solid. The product was recrystallized from a mixed solvent of n-hexane and toluene (15/1) to give 10g of pale yellow solid.

Synthesis example 2

Synthesis of Compound-3

Synthesis of intermediate M4

In a four-necked flask equipped with a condenser, 2-bromodibenzothiophene (20 g, 76 mmol), p-chlorobenzeneboronic acid (14.3 g, 91 mmol), potassium carbonate (15.8 g, 114 mmol) were added to a mixed solvent of toluene (200 mL) and ethanol (50 mL), water (50 mL), stirred uniformly, and then Pd (PPh) was added under nitrogen ₃ ) ₄ (0.9 g,0.76 mmol) was heated to 100deg.C and reacted for 18h. After cooling to room temperature, 300mL of saturated aqueous salt solution was directly added, the aqueous phase was extracted twice with 300mL of ethyl acetate, the organic phases were combined, dried over anhydrous sodium sulfate and concentrated to a pale yellow solid. The crude product was recrystallized from methanol and methylene chloride to give 10g of white solid;

synthesis of Compound-3

The synthesis of compound-3 can be performed by referring to compound-1 and substituting intermediate M4 for M3 to give a pale yellow solid.

Synthesis example 3

Synthesis of Compound-2

Synthesis of intermediate M5

The synthesis method of the intermediate M5 is the same as that of the intermediate M4, and the reaction raw material is changed into 4-bromodibenzothiophene. A white solid was obtained.

Synthesis of Compound-2

Synthesis of Compound-2 and Synthesis of Compound-1. The intermediate M5 is used as a reaction raw material to replace M3, and finally light yellow solid is obtained.

Synthesis example 4

Synthesis of Compound-5

Synthesis of intermediate M6

In a four-necked flask equipped with a condenser, N-phenyl-3-bromocarbazole (70 g, 218 mmol), p-chlorophenylboronic acid (41 g, 260 mmol), potassium carbonate (45 g, 325 mmol) were added to a mixed solvent of THF (700 mL) and water (100 mL), stirred uniformly, and then Pd was added under nitrogen protection ₂₍ dba) ₃ (1.26 g,1.38 mmol) was heated to 60℃and reacted for 18h. After cooling to room temperature, 500mL of saturated aqueous salt solution was directly added, the aqueous phase was extracted twice with 500mL of ethyl acetate, the organic phases were combined, dried over anhydrous sodium sulfate, and concentrated to give a brown oil. The crude product was extracted with a mixed solution of petroleum ether and ethyl acetate and concentrated to give 65g of a yellow solid.

Synthesis of Compound-5

Referring to the synthetic procedure for compound-1, intermediate M6 was used instead of M3 to give a pale yellow solid.

Synthesis example 5

Synthesis of Compound-6

Synthesis of intermediate M7

Into a four-necked flask equipped with a condenser tube, 3-bromofluoranthene (20 g, 71 mmol), p-chlorobenzoic acid (1)2.3g, 78 mmol), potassium carbonate (12.9 g, 92.5 mmol) was added to a mixed solvent of THF (350 mL) and water (50 mL), stirred well, and then Pd (PPh) was added under nitrogen protection ₃ ) ₄ (82 mg,0.71 mmol) was heated to 100deg.C and reacted for 18h. After cooling to room temperature, 300mL of saturated aqueous salt solution was directly added, the aqueous phase was extracted twice with 300mL of ethyl acetate, the organic phases were combined, dried over anhydrous sodium sulfate and concentrated to a pale yellow solid. The crude product was recrystallized from methanol and dichloromethane to give 16g of yellow solid;

Synthesis of Compound-6

Referring to the synthetic procedure for compound-1, intermediate M7 was used instead of M3 to give a yellow solid.

Synthesis example 6

Synthesis of Compound-16

Synthesis of intermediate M8

Carbazole (20 g,120 mmol), 4-bromo-2-chloro-1 fluorobenzene (30 g,144 mmol), cesium carbonate (30 g,155 mmol), DMF (400 mL) were added to a three-necked flask, the temperature was raised to 100℃under nitrogen protection, the reaction was stirred for 20h, the reaction solution was poured into 500mL saturated saline after cooling, extracted twice with 300mL ethyl acetate, the organic phases were combined, dried over anhydrous sodium sulfate, concentrated, and the crude product was purified by silica gel column chromatography (PE/EA, 7/1) to give a white solid 30g.

Synthesis of intermediate M9

In a four-necked flask equipped with a condenser, M8 (20 g, 56 mmol), phenylboronic acid (8.2 g, 67 mmol), potassium carbonate (10 g, 73 mmol) were added to a mixed solvent of toluene (300 mL), ethanol (150 mL) and water (150 mL), and stirred uniformly, and then Pd (PPh) was added under nitrogen protection ₃ ) ₄ (1.3 g,1.12 mmol) was heated to 100deg.C and reacted for 18h. After cooling to room temperature, 300mL of saturated aqueous salt solution was directly added, the aqueous phase was extracted twice with 300mL of ethyl acetate, the organic phases were combined, dried over anhydrous sodium sulfate and concentrated to a pale yellow solid. The crude product was purified by column chromatography on silica gel to give 11g of yellow solid.

Synthesis of Compound-16

Referring to the synthesis method of the compound-1, the intermediate M9 is used for replacing M3, xylene is used for replacing toluene as a solvent, and temperature reflux is carried out to obtain a yellow solid product.

Synthesis example 7

Synthesis of Compound-250

Similar Compound-250 can be obtained from the following synthetic route

Specific synthetic methods can be referred to the synthetic conditions of compound-1. Obtained as a pale yellow solid.

Synthesis example 8

Synthesis of Compound-248

Specific synthetic methods can be referred to the synthetic conditions of compound-1. A yellow solid was obtained.

By substitution of different Ar-X ₂ (sometimes referred to in the art as aryl halides) different target compounds may be obtained. In the above synthesis method, the intermediate M is coupled to the intermediate A-2 by using Buchwald-Hartwig coupling, but not limited to this coupling method, and those skilled in the art may select other methods, such as Stille coupling method, grignard reagent method, kumada-Tamao, etc., known methods, but not limited to these methods, and any equivalent synthesis method may be used to achieve the coupling of the substituent A ₁ And A ₂ The purpose of attachment to the benzopyrene ring can be selected as desired.

Device comparative example 1

In this comparative example, an organic electroluminescent device is provided as shown in fig. 1.

The organic electroluminescent device in this comparative example was prepared as follows:

the glass plate coated with the ITO transparent conductive layer was sonicated in commercial cleaners, rinsed in deionized water, and rinsed in acetone: ultrasonic degreasing in ethanol mixed solvent, baking in clean environment to completely remove water, cleaning with ultraviolet light and ozone, and bombarding surface with low-energy cation beam;

placing the above glass substrate with anode in vacuum chamber, and vacuumizing to 1×10 ^-5 ～9×10 ^-3 Pa, vacuum evaporating HI-1 as a hole injection layer on the anode layer film, wherein the evaporation rate is 0.1nm/s, and the thickness of the evaporation film is 10nm;

vacuum evaporation HT-1 is carried out on the hole injection layer to serve as a hole transmission layer of the device, the evaporation rate is 0.1nm/s, and the total film thickness of evaporation is 80nm;

vacuum evaporating a second electron blocking layer on the hole transport layer, wherein the second electron blocking layer comprises a main material compound-1 and a guest material HI-1, the evaporation rate of the main material compound-1 is regulated to be 0.1nm/s by utilizing a multi-source co-evaporation method, the evaporation rate of the guest material HI-1 is set according to the proportion of 1% of the evaporation rate of the main material, and the total evaporation film thickness is 80nm;

vacuum evaporating material compound-1 on the second electron blocking layer to serve as a first electron blocking layer of the device, wherein the evaporation rate is 0.1nm/s, and the total film thickness of evaporation is 1nm;

Vacuum evaporating a luminescent layer of the device on the first electron blocking layer, wherein the luminescent layer comprises a main material and a dye material, the evaporation rate of the main material RH-1 is regulated to be 0.1nm/s by utilizing a multi-source co-evaporation method, the evaporation rate of the dye RPD-1 is set according to the proportion of 5% of the main material, and the total evaporation film thickness is 40nm;

an electron transport layer material ET-1 of the vacuum evaporation device on the luminescent layer has an evaporation rate of 0.1nm/s and an evaporation total film thickness of 30nm;

LiF with the thickness of 0.5nm is vacuum evaporated on an Electron Transport Layer (ETL) to serve as an electron injection layer, and an Al layer with the thickness of 150nm serves as a cathode of the device.

Device comparative example 2

The present comparative example differs from comparative device example 1 only in that a second electron blocking layer comprising a host material compound-1 and a guest material HI-1 was vacuum-deposited on top of the hole transport layer, the deposition rate of the host material compound-1 was adjusted to 0.1nm/s by a multi-source co-evaporation method, the deposition rate of the guest material HI-1 was set in accordance with a 1% ratio of the deposition rate of the host material, and the total deposition film thickness was 80nm.

And vacuum evaporating material compound-1 on the second electron blocking layer to obtain the first electron blocking layer of the device, wherein the evaporation rate is 0.1nm/s, and the total evaporation film thickness is 4nm.

Device comparative example 3

And vacuum evaporating material compound-1 on the second electron blocking layer to obtain the first electron blocking layer of the device, wherein the evaporation rate is 0.1nm/s, and the total evaporation film thickness is 65nm.

Device comparative example 4

The present comparative example differs from comparative device example 1 only in that a second electron blocking layer comprising a host material compound-1 and a guest material HI-1 was vacuum-deposited on top of the hole transport layer, the deposition rate of the host material compound-1 was adjusted to 0.1nm/s by a multi-source co-evaporation method, the deposition rate of the guest material HI-1 was set in accordance with a 1% ratio of the deposition rate of the host material, and the total deposition film thickness was 35nm.

And vacuum evaporating material compound-1 on the second electron blocking layer to obtain the first electron blocking layer of the device, wherein the evaporation rate is 0.1nm/s, and the total evaporation film thickness is 40nm.

Device comparative example 5

The present comparative example differs from comparative device example 1 only in that a second electron blocking layer comprising a host material compound-1 and a guest material HI-1 was vacuum-deposited on top of the hole transport layer, the deposition rate of the host material compound-1 was adjusted to 0.1nm/s by a multi-source co-evaporation method, the deposition rate of the guest material HI-1 was set in accordance with a 1% ratio of the deposition rate of the host material, and the total deposition film thickness was 105nm.

Device comparative example 6

The present comparative example differs from the device comparative example 1 only in that the second electron blocking layer was vacuum-deposited on top of the hole transporting layer, comprising only the main material compound-1, and the evaporation rate of the main material compound-1 was adjusted to 0.1nm/s, and the total film thickness of the evaporation was 80nm.

Device comparative example 7

The present comparative example differs from the device comparative example 1 only in that the first electron blocking layer was directly vapor deposited by vacuum vapor deposition on top of the hole transport layer, comprising only the main material compound-1, and the vapor deposition rate of the main material compound-1 was adjusted to 0.1nm/s, and the total vapor deposition film thickness was 40nm.

Device comparative example 8

And the luminescent layer of the vacuum evaporation device is arranged on the second electron blocking layer, the luminescent layer comprises a main material and a dye material, the evaporation rate of the main material RH-1 is regulated to be 0.1nm/s by utilizing a multi-source co-evaporation method, the evaporation rate of the dye RPD-1 is set according to the proportion of 5% of the main material, and the total evaporation film thickness is 40nm.

Device comparative example 9

The present comparative example differs from the device comparative example 1 only in that a second electron blocking layer comprising a host material compound-1 and a guest material HI-1 was vacuum-deposited on top of the hole transport layer, the deposition rate of the host material compound-1 was adjusted to 0.1nm/s by a multi-source co-evaporation method, the deposition rate of the guest material HI-1 was set in a proportion of 0.5% of the deposition rate of the host material, and the total deposition film thickness was 80nm.

Device comparative example 10

The comparative example differs from comparative device example 1 only in that a second electron blocking layer comprising a host material compound-1 and a guest material HI-1 was vacuum-deposited on top of the hole transport layer, the deposition rate of the host material compound-1 was adjusted to 0.1nm/s by a multi-source co-evaporation method, the deposition rate of the guest material HI-1 was set in accordance with the 10% ratio of the deposition rate of the host material, and the total deposition film thickness was 80nm.

Device comparative example 11

The comparative example differs from comparative device example 1 only in that a second electron blocking layer comprising a host material HT4 and a guest material HI-1 was vacuum-deposited on top of the hole transport layer, the vapor deposition rate of the host material HT4 was adjusted to 0.1nm/s by a multi-source co-evaporation method, the vapor deposition rate of the guest material HI-1 was set in a proportion of 1% of the vapor deposition rate of the host material, and the total vapor deposition film thickness was 80nm.

Vacuum evaporation material HT4 is used as a first electron blocking layer of the device on the second electron blocking layer, the evaporation rate is 0.1nm/s, and the total film thickness of evaporation is 40nm.

Device example 1

In the following examples, an organic electroluminescent device having a structure including a cathode, an electron injection layer, an electron transport layer, a light emitting layer, a first electron blocking layer, a second electron blocking layer, a hole transport layer, a hole injection layer, and an anode in this order from top to bottom was prepared and tested for performance as shown in fig. 1. Wherein the electron blocking layer includes a first electron blocking layer and a second electron blocking layer, and the second electron blocking layer is composed of a host material and a guest material.

The preparation process of the organic electroluminescent device in this embodiment is as follows:

vacuum evaporating material compound-1 on the second electron blocking layer to serve as a first electron blocking layer of the device, wherein the evaporation rate is 0.1nm/s, and the total film thickness of evaporation is 40nm;

Device example 2

The embodiment differs from the device embodiment 1 only in that the evaporation rate ratio of the host material and the guest material in the second electron blocking layer is 1:0.02, and the thickness is unchanged.

Device example 3

The embodiment is different from the device embodiment 1 only in that the evaporation rate ratio of the host material and the guest material in the second electron blocking layer is 1:0.03, and the thickness is unchanged.

Device example 4

The embodiment is different from the device embodiment 1 only in that the evaporation rate ratio of the host material and the guest material in the second electron blocking layer is 1:0.09, and the thickness is unchanged.

Device example 5

This embodiment differs from device embodiment 1 only in that the thickness of the second electron blocking layer is 40nm.

Device example 6

This embodiment differs from device embodiment 1 only in that the thickness of the second electron blocking layer is 50nm.

Device example 7

This embodiment differs from device embodiment 1 only in that the thickness of the second electron blocking layer is 70nm.

Device example 8

This embodiment differs from device embodiment 1 only in that the thickness of the second electron blocking layer is 80nm.

Device example 9

This embodiment differs from device embodiment 1 only in that the thickness of the second electron blocking layer is 100nm.

Device example 10

This embodiment differs from device embodiment 1 only in that the thickness of the first electron blocking layer is 5nm.

Device example 11

This embodiment differs from device embodiment 1 only in that the thickness of the first electron blocking layer is 50nm.

Device example 12

This embodiment differs from device embodiment 1 only in that the thickness of the first electron blocking layer is 60nm.

Device examples 13 to 24

An organic electroluminescent device was prepared according to the method of device example 1, as shown in table 1.

Device preparation containing light emitting regions of different colors:

Device example 25

placing the above glass substrate with anode in vacuum chamber, and vacuumizing to 1×10 ^-5 ～9×10 ^-3 Pa, selecting a through hole mask, and vacuum evaporating HI-1 on the anode layer film as a hole injection layer, wherein the evaporation rate is 0.1nm/s, and the evaporation film thickness is 10nm;

blue light pixel point evaporation: vacuum evaporating a compound-1 on the hole transport layer by using a fine mask plate to serve as a first electron blocking layer of the device, wherein the evaporation rate is 0.1nm/s, and the total film thickness of evaporation is 50nm; vacuum evaporation of a blue light emitting layer of a first light emitting area on the first electron blocking layer, wherein the blue light emitting layer comprises a blue light main body compound BFH-1 and a blue light dye material BFD-1, the evaporation rate of the blue light main body compound BFH-1 is regulated to be 1nm/s by utilizing a multi-source co-evaporation method, the evaporation rate of the blue light dye material BFD-1 is set according to the proportion of 5% of the evaporation rate of the main body compound, and the total evaporation film thickness is 30nm;

Red (yellow) pixel point evaporation:

evaporating a second electron layer by using a fine mask, wherein the second electron blocking layer comprises a host material and a guest material, the materials and the proportion are the same as those in the embodiment 1, and the evaporating thickness is 80nm; evaporating the first electron blocking layer by using a fine mask plate, wherein the evaporation rate is 0.1nm/s, and the total evaporation film thickness is 50nm; continuously evaporating a second light-emitting area by using a fine mask, and vacuum evaporating a red (yellow) light-emitting layer on the first electron blocking layer, wherein the red (yellow) light-emitting layer comprises a red (yellow) light main compound RH-1 and a red (yellow) light dye material RPD-1 (YPD-1), the evaporation rate of the red (yellow) light main compound RH-1 is regulated to be 1nm/s by using a multi-source co-evaporation method, the evaporation rate of the red (yellow) light dye material RPD-1 (YPD-1) is set according to the proportion of 5 percent (10 percent) of the evaporation rate of the main compound, and the total evaporation film thickness is 30nm;

and (3) vapor plating of green light pixels: evaporating a second electron blocking layer by using a fine mask, wherein the second electron blocking layer comprises a host material and a guest material, the materials and the proportion are the same as those in the embodiment 1, and the evaporating thickness is 60nm; evaporating the first electron blocking layer by using a fine mask plate, wherein the evaporation rate is 0.1nm/s, and the total evaporation film thickness is 50nm; continuously evaporating a third light-emitting area by using a fine mask to perform vacuum evaporation of a green light-emitting layer, wherein the third light-emitting area comprises a green light main body compound GPH-1 and a green light dye material GPD-1, the evaporation rate of the green light main body compound GPH-1 is regulated to be 1nm/s by using a multi-source co-evaporation method, the evaporation rate of the green light dye material GPD-1 is set according to the proportion of 5% of the evaporation rate of the main body compound, and the total evaporation film thickness is 30nm;

After the evaporation of the luminescent layers in the three areas is completed, switching to a through hole mask, and continuing to evaporate an electron transport layer material ET-1 of the device in a vacuum way, wherein the evaporation rate is 0.1nm/s, and the total film thickness of evaporation is 30nm;

Examples 26 to 34

An organic electroluminescent device was prepared according to the method of example 25, as shown in table 2.

Device comparative examples 12 to 13

Description of the method

Device comparative example 12:

this comparative example differs from device example 25 only in that:

the second electron blocking layer of the second light emitting region comprises a host material and a guest material, and the vapor deposition thickness is 70nm.

Device comparative example 13:

this comparative example differs from device example 25 only in that:

the second electron blocking layer of the second light-emitting area comprises a host material and a guest material, and the vapor deposition thickness is 90nm;

the second electron blocking layer of the third light emitting region comprises a host material and a guest material, and the vapor deposition thickness is 90nm.

The organic electroluminescent device prepared by the above procedure was subjected to the following performance measurement:

the driving voltage and current efficiency and the lifetime of the organic electroluminescent devices manufactured in examples 1 to 24 and comparative examples 1 to 11 were measured using a digital source meter and a luminance meter at the same luminance. Specifically, the luminance of the organic electroluminescent device was measured to reach 100cd/m by increasing the voltage at a rate of 0.1V per second ² The voltage at the time is the driving voltage, and the current density at the time is measured; the ratio of brightness to current density is the current efficiency; the lifetime test of LT90 is as follows: at 5000cd/m using a luminance meter ² Under the condition of brightness, constant current is kept, and the brightness of the organic electroluminescent device is measured to be reduced to 4500cd/m ² Time in hours.

The organic electroluminescent device performance is shown in Table 1 below, wherein the data in Table 1 are relative values of (1, 1) based on comparative example 2.

TABLE 1 organic electroluminescent device Performance of examples 1-24 and comparative examples 1-11

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Examples 25-34 and comparative examples 12-13 had a required luminance of 100cd/m ² The lower display device performance is shown in table 2, and the data in table 2 are relative values of (1, 1) based on comparative example 12.

TABLE 2 organic electroluminescent device Properties of examples 25-34 and comparative examples 12-13

The properties of the organic electroluminescent host materials used in the examples are shown in Table 3:

TABLE 3 Properties of organic electroluminescent host materials

Material	HOMO	LUMO	Mobility of	T1
					Compound-1	-5.22	-1.72	8.33×10 ^-5 cm ² /Vs	2.8
Compound 8	-5.20	-1.75	9.62×10 ^-5 cm ² /Vs	/
					Compound 90	-5.21	-1.73	8.62×10 ^-5 cm ² /Vs	/
HI-1	-7.74	-5.34	/	/
					BFH-1	-5.38	-2.25	/	2.6

The results show that the novel device structure provided by the invention has the advantages that the electron blocking layer is introduced, the electron blocking layer comprises the first electron blocking layer and the second electron blocking layer, the first electron blocking layer is made of the first electron blocking layer material, the second electron blocking layer comprises the second electron blocking layer main material and the second electron blocking layer guest material, and when the novel device structure is used for devices and display devices, excessive electrons transmitted from one side of the light emitting layer can be blocked, the device efficiency is effectively improved, and the phenomena of quenching of the guest material and the like are reduced through double-layer arrangement. Therefore, the voltage drop and start can be effectively reduced, and the current efficiency is improved.

According to an embodiment of the present invention, it can be seen that the electron blocking layer is configured to include a first electron blocking layer and a second electron blocking layer, wherein the second electron blocking layer includes a host material and a guest material, and is capable of reducing a device voltage by up to about 40%, and improving a current efficiency by up to about 30%.

The applicant states that the present invention is described by the above embodiments as an organic electroluminescent device of the present invention, but the present invention is not limited to the above embodiments, i.e. it does not mean that the present invention must be implemented depending on the above embodiments. It should be apparent to those skilled in the art that any modification of the present invention, equivalent substitution of selected raw materials, addition of auxiliary components, selection of specific modes, etc. fall within the scope of the present invention and the scope of disclosure.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific details of the above embodiments, and various simple modifications can be made to the technical solution of the present invention within the scope of the technical concept of the present invention, and all the simple modifications belong to the protection scope of the present invention.

In addition, the specific features described in the above embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, various possible combinations are not described further.

Moreover, any combination of the various embodiments of the invention can be made without departing from the spirit of the invention, which should also be considered as disclosed herein.

It is apparent that the above examples are given by way of illustration only and are not limiting of the embodiments. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. It is not necessary here nor is it exhaustive of all embodiments. While still being apparent from variations or modifications that may be made by those skilled in the art are within the scope of the invention.

Claims

1. An organic electroluminescent device comprising one or more light emitting regions, each light emitting region comprising in sequence a cathode, a light emitting layer, an electron blocking layer and an anode, the electron blocking layer comprising a first electron blocking layer, wherein the electron blocking layer of at least one light emitting region further comprises a second electron blocking layer located between the anode and the first electron blocking layer, the first electron blocking layer being composed of a first electron blocking layer material, the second electron blocking layer comprising a second electron blocking layer host material and a second electron blocking layer guest material;

Wherein the first electron blocking layer material and/or the second electron blocking layer main material is selected from compounds represented by the following general formula (I),

wherein L independently represents a single bond, a substituted or unsubstituted C6-C30 arylene group, or a substituted or unsubstituted C3-C30 heteroarylene group,

R ^a 、R ^b the same or different, each independently selected from C1-C20 alkyl, C1-C20 alkenyl, C1-C20 alkynyl, R ^a 、R ^b Optionally linked to form a ring structure, R is selected from the group consisting of C1-C20 alkyl, C1-C20 alkenyl, C1-C20 alkynyl, C1-C20 alkoxy, C6-C30 aryl, C3-C30 heteroaryl,

p is an integer of 0 to 7,

ar is selected from substituted or unsubstituted C6-C30 aryl or substituted or unsubstituted C3-C30 heteroaryl.

2. The organic electroluminescent device of claim 1, wherein the first electron blocking layer of each light emitting region is the same.

3. The organic electroluminescent device of claim 1, wherein a molar ratio of the second electron blocking layer host material to the second electron blocking layer guest material is from 1:0.01 to 1:0.09.

4. An organic electroluminescent device according to any one of claims 1 to 3, wherein the first electron blocking layer has a thickness of 5-60nm and the second electron blocking layer has a thickness of 40-100nm.

5. The organic electroluminescent device according to any one of claims 1 to 3, wherein at least one light emitting region including the first electron blocking layer and the second electron blocking layer is a red light emitting region, a yellow light emitting region, or a green light emitting region.

6. The organic electroluminescent device according to claim 5, wherein when the light emitting region is a red light emitting region, wherein the thickness of the second electron blocking layer is 80-100nm; when the light emitting region is a green light emitting region, wherein the thickness of the second electron blocking layer is 60-80nm; when the light emitting region is a yellow light emitting region, the thickness of the second electron blocking layer is 70-90nm.

7. An organic electroluminescent device according to any one of claims 1 to 3, comprising a plurality of light emitting regions, wherein at least one light emitting region is a blue light emitting region, the electron blocking layer of which consists of the first electron blocking layer.

8. An organic electroluminescent device according to any one of claims 1 to 3, the first electron blocking layer material being the same material as the second electron blocking layer host material.

9. The organic electroluminescent device as claimed in any one of claims 1 to 3, wherein,

ar is selected from a substituted or unsubstituted C6-C30 aryl group or a heteroaryl group represented by the general formula (A),

In the formula (A), the components of the compound,

L ¹ independently represents a single bond, a substituted or unsubstituted C6-C30 arylene group or a substituted or unsubstituted C3-C30 heteroarylene group, "" represents a linking site with the parent nucleus,

R ¹ selected from the group consisting of C1-C20 alkyl, C1-C20 alkenyl, C1-C20 alkynyl, C1-C20 alkoxy, C6-C30 aryl, C3-C30 heteroaryl, and a plurality of R ¹ Identical or different, two R's in adjacent positions ¹ Optionally linked to form a ring; q is an integer of 0 to 7,

x is selected from O, S, NR ² 、SiR ³ R ⁴ ；R ² 、R ³ 、R ⁴ Each independently selected from C1-C12 alkyl, substituted or unsubstituted C6-C30 aryl or substituted or unsubstituted C3-C30 heteroaryl, R ³ And R is ⁴ Can be connected to form a ring by means of an interconnection,

10. The organic electroluminescent device according to claim 9, wherein the compound represented by the general formula (I) is selected from the following compounds:

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11. an organic electroluminescent device according to any one of claims 1 to 3, wherein the second electron blocking layer guest material is selected from one or more of HI-1 to HI-3.

12. The organic electroluminescent device according to any one of claims 1 to 3, further comprising one or more of an electron injection layer, an electron transport layer, a hole blocking layer, a hole transport layer, a hole injection layer.

13. The organic electroluminescent device of claim 4, wherein the first electron blocking layer has a thickness of 5-40nm and the second electron blocking layer has a thickness of 60-100nm.

14. The organic electroluminescent device of claim 9, wherein q is 0 or 1.

15. An organic light emitting device comprising the organic electroluminescent device as claimed in any one of claims 1 to 14.

16. A method of preparing the organic electroluminescent device of any one of claims 1 to 14, comprising the steps of:

s1: forming an anode;

s2: forming an electron blocking layer comprising:

s3: forming a light-emitting layer; and

s4: forming a cathode.

17. The method according to claim 16, wherein the evaporation rate ratio of the second electron blocking layer host material to the second electron blocking layer guest material in step S21 is 1:0.01-1:0.09.