CN112242492A

CN112242492A - Organic electroluminescent device and preparation method

Info

Publication number: CN112242492A
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: 2021-01-19
Anticipated expiration: 2039-07-18
Also published as: CN112242492B

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 main material and a second electron blocking layer guest material. The present invention also provides an organic light emitting device including the organic electroluminescent device and a method of manufacturing the organic electroluminescent device.

Description

Organic electroluminescent device and preparation method

Technical Field

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

Background

An Organic Light emitting Display (abbreviated as OLED) is an active Light emitting Display device, and is expected to become a next generation mainstream panel Display technology due to its advantages of simple manufacturing process, low cost, high contrast, wide viewing angle, low power consumption, and the like, and is one of the most concerned technologies in the panel Display technology at present.

In top emission devices, hole transport materials (including hole injection layer, hole transport layer, electron blocking layer) are usually made thicker to obtain devices conforming to optical path, especially for red devices, which are 250nm thick. The device thickness of the layer is too thick, so that the problems of high voltage, low efficiency and the like of the device are caused. P-type dopants are usually doped in the hole transport material to improve the transport capability of holes, thereby improving the efficiency of the device and reducing the voltage of the device.

Disclosure of Invention

In view of the above problems in the prior art, the present inventors have conducted extensive research and design a novel device structure, in which a light-emitting layer is not in direct contact with a layer doped with a p-type dopant, so as to reduce the occurrence of crosstalk problem of the device and avoid quenching caused by introduction of the p-type dopant on the basis of improving hole transport capability.

In one aspect, an organic electroluminescent device is provided, comprising one or more light emitting areas, each light emitting area 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 area 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.

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

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 host material}︱≥0.05。

In some embodiments, the first electron blocking layer in the organic electroluminescent device 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 100 nm.

In some embodiments, the first electron blocking layer material in the organic electroluminescent device is the same as the second electron blocking layer host material, and the hole mobility of the material is not less than 3.0 × 10^-5cm²Vs and satisfies the | LUMO_{Luminescent host materials}︱－︱LUMO_{Second electron blocking layer host material}| is not less than 0.5, and the triplet energy level of the primary material of the second electron blocking layer is higher than that of the luminescent primary material, or

The first electron barrier layer material is different from the second electron barrier layer main material, and the mobility of the first electron barrier layer material is not less than 8.0 x 10^-5cm²Vs and satisfies | HOMO_{Luminescent host materials}︱＞︱HOMO_{First electron blocking layer material}︱＞︱HOMO_{Second electron blocking layer host 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 organic electroluminescent device has a thickness of the second electron blocking layer of 80-100nm when the light-emitting region is a red light-emitting region, a thickness of the second electron blocking layer of 60-80nm when the light-emitting region is a green light-emitting region, and a thickness of the second electron blocking layer of 70-90nm when the light-emitting region is a yellow light-emitting region.

In some embodiments, the organic electroluminescent device includes a plurality of light-emitting regions, at least one of which is a blue light-emitting region whose electron blocking layer is composed of the 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 still another aspect, the present invention provides an organic light emitting device comprising the above organic electroluminescent device.

In a further 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 barrier material to form a first electron barrier layer;

s3: forming a light emitting layer; and

s4: a cathode is formed.

The invention has the following beneficial effects:

the invention provides a novel device structure, wherein an electron blocking layer is arranged to comprise a first electron blocking layer and a second 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, so that a light emitting layer is not in direct contact with a layer doped with a p-type dopant, the cross talk problem of the device is reduced on the basis of improving the hole transport capability, and quenching caused by introduction of the p-type dopant is avoided.

Drawings

Fig. 1 shows a schematic structural view 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;

EBL 1: a first electron blocking layer;

EBL 2: a second electron blocking layer;

HTL: a hole transport layer;

HIL: a hole injection layer;

HBL: a hole blocking layer;

r EML: a red pixel light emitting layer;

g EML: a green pixel light emitting layer;

b, EML: a blue pixel light emitting layer;

y EML: and the yellow pixel light-emitting layer.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below. The matter set forth herein with respect to the various aspects and embodiments is not limited to the relevant portions, but may be combined in any suitable manner without contradiction.

In this specification, terms indicating orientation or positional relationship such as "upper", "lower", "left", "right", "inner", "outer", and the like are for the purpose of describing the present invention only, for example, for describing the relationship between the components of the device corresponding to the drawings, but they should not be construed as limiting the present invention in any way, that is, they should not be construed as being limited to the specific positional or orientational relationship described. The drawings are for illustrative purposes only, and the sizes, proportions, positional relationships, and the like shown therein are not intended to limit the scope of the present invention in any way.

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

in the present invention, the expression of Ca to Cb means that the group has carbon atoms a to b, and the carbon atoms do not include the carbon atoms of the substituents unless otherwise specified. In the present invention, the expression of chemical elements includes the concept of chemically identical isotopes, such as the expression of "hydrogen", and also includes the concept of chemically identical "deuterium" and "tritium". In the present invention, "D" may be used to represent "deuterium".

In the present specification, the term "substituted or unsubstituted" means substituted with one or more substituents selected from halogen, cyano, hydroxyl, alkyl groups of C1 to C12, alkoxy groups of C1 to C12, aryl groups of C6 to C12, and heteroaryl groups of C3 to C12, preferably fluorine, cyano, methoxy, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, phenyl, biphenyl, naphthyl, phenanthryl, fluorenyl, dibenzofuranyl, dibenzothiophenyl, pyridyl, quinolyl, phenylpyridinyl, 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 alkyl groups 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 the present specification, the heteroaryl group is a heteroaryl group containing at least one of O, N, S, Si as a heteroatom, 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 include fused ring groups.

In the present specification, the expression of the "-" underlined loop structure means that the linking site is located at an arbitrary position on the loop structure where the linking site can be bonded.

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 main 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 (EBL1), a second electron blocking layer (EBL2), a Hole Transport Layer (HTL), and a Hole Injection Layer (HIL) 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 a substrate. The substrate is generally a glass or polymer material having excellent mechanical strength, thermal stability, water resistance, and transparency. In addition, 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) can be used₂) And transparent conductive oxide materials such as zinc oxide (ZnO), and any combination thereof. As the cathode, a metal or an alloy such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), or any combination thereof can be used.

The electron blocking layer of at least one light emitting region in the organic electroluminescent device is arranged to comprise at least two layers, the first electron blocking layer and the second electron blocking layer are respectively arranged from the cathode to the anode, the first electron blocking layer is composed 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 composed 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 device efficiency, but also reduces the probability of quenching the device.

The electron blocking layer can 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-evaporation, spin coating or printing of the second electron blocking layer host material and the second electron blocking layer guest material, for example, may be formed by vacuum multi-source co-evaporation. The proportion of 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 rate of the second electron blocking layer host material and the second electron blocking layer guest material.

Satisfying the energy level relation can ensure a smaller energy level barrier between the main material and the guest material.

In some embodiments, the thickness of the first electron blocking layer in the organic electroluminescent device is from 40 to 60nm and the thickness of the second electron blocking layer is from 60 to 100 nm.

The light-emitting layer contains a light-emitting material. The light-emitting layer includes a light-emitting material (i.e., dopant) that can emit different wavelength spectra, and may also include a Host material (Host).

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

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

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

In one aspect of the invention, the light-emitting layer employs phosphorescent electroluminescent technology. The host material of the light emitting layer 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 electroluminescent technology. The phosphorescent dopant of the light emitting layer can be selected from, but is not limited to, one or more of GPD-1 to GPD-47 listed below.

In one aspect of the invention, the light emitting layer employs a phosphorescent electroluminescent technology, with the host material of the light emitting layer being selected from, but not limited to, a combination of one or more of RH-1 to RH-31.

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

In one aspect of the invention, the light-emitting layer employs phosphorescent electroluminescent technology. The phosphorescent dopant of the light-emitting layer can be selected from, but is not limited to, one or more 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 hole mobility of the material is not smallAt 3.0X 10^-5cm²Vs and satisfies the | LUMO_{Luminescent host materials}︱－︱LUMO_{Second electron blocking layer host material}The | is more than or equal to 0.5, and the triplet energy level of the main material of the second electron barrier layer is higher than that of the luminescent main 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 8.0 x 10^-5cm²Vs and satisfies | HOMO_{Luminescent host materials}︱＞︱HOMO_{First electron blocking layer material}︱＞︱HOMO_{Second electron blocking layer host material}An | is dispensed. The condition is satisfied, so that the barrier energy level between the luminescent material and the barrier material is ensured to be in a descending trend, and the difference between the barriers is reduced.

In some embodiments, the first electron blocking layer of each light emitting region in the organic electroluminescent device is the same. For example, the material and thickness of the first electron blocking layer are the same. When the first electron layer is made of the same material and has the same thickness, the mass production process can be reduced, namely, the evaporation can be finished by using the OPEN MASK once.

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 single color light emitting layers of a plurality of different colors may be arranged in a planar manner in accordance with a pixel pattern, or may be stacked 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 emitting red, green, blue, yellow, or the like at the same time.

Since the optical coupling thicknesses (thin films) corresponding to 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 regions of 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 of the light emitting regions in the organic electroluminescent device is a blue light emitting region, and the electron blocking layer does not include the 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, a blue region 210, a red region 220, and a green region 230, and includes a cathode 201 and an anode 202, and further includes a light emitting layer (EML), a first electron blocking layer (EBL1), and a second electron blocking layer (EBL2) in a direction from the cathode 201 to the anode 202, wherein the blue region 210 includes only the first electron blocking layer (EBL1) and does not include the second electron blocking layer (EBL2), and the red region 220 and the green region 230 each include the first electron blocking layer (EBL1) and the second electron blocking layer (EBL2), respectively.

Fig. 3 shows an organic electroluminescent device 300 according to an embodiment of the present application, which includes 3 light emitting regions, a blue region 310, a red region 320, and a green region 330, and includes a cathode 301 and an anode 302, and further includes a light emitting layer (EML), a first electron blocking layer (EBL1), and a second electron blocking layer (EBL2) in a direction from the cathode 301 to the anode 302, wherein the blue region 310 and the green region 330 include only the first electron blocking layer (EBL1) and not the second electron blocking layer (EBL2), and the red region 320 includes the first electron blocking layer (EBL1) and the second electron blocking layer (EBL 2).

Fig. 4 shows an organic electroluminescent device 400 according to an embodiment of the present application, including 3 light emitting regions, a blue region 410, a red region 420, and a green region 430, the light emitting device including a cathode 401 and an anode 402, and further including a light emitting layer (EML), a first electron blocking layer (EBL1), and a second electron blocking layer (EBL2) in a direction from the cathode 401 to the anode 402, wherein the blue region 410 and the red region 420 include only the first electron blocking layer (EBL1) and not the second electron blocking layer (EBL2), and the green region 430 includes the first electron blocking layer (EBL1) and the second electron blocking layer (EBL 2).

Fig. 5 shows an organic electroluminescent device 500 according to an embodiment of the present application, including 2 light emitting regions, a blue region 510 and a yellow region 420, respectively, the light emitting device including a cathode 501 and an anode 502, and further including a light emitting layer (EML), a first electron blocking layer (EBL1), and a second electron blocking layer (EBL2) in a direction from the cathode 501 to the anode 502, wherein the blue region 510 includes only the first electron blocking layer (EBL1) and not the second electron blocking layer (EBL2), and the yellow region 520 includes the first electron blocking layer (EBL1) 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, a blue region 610, a red region 620, and a green 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 (EBL1), a second electron blocking layer (EBL2), 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 (EBL1) and does not include the second electron blocking layer (EBL2), the red region 620 and the green region 630 each include the first electron blocking layer (EBL1) and the second electron blocking layer (EBL2), respectively.

In some embodiments, the first electron blocking layer material and/or the second electron blocking layer host material is selected from compounds of 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 a phenyl group, a biphenylene group, a terphenylene group, a naphthylene group, an anthracenylene group, a phenanthrenylene group, a fluorenylene group, a pyrenylene group

Mesitylene, fluorenylene, benzolene [ a]Anthracenyl, benzo [ c ] idene]Phenanthryl, YazhiPhenyl, phenylene [ k ]]Fluoranthenyl, benzidene [ g ]]

Radical, phenylene [ b]Triphenylene, phenyleneyl, peryleneyl, etc., among which phenylene, naphthylene, biphenylene are preferred, and phenylene is more preferred.

R^a、R^bThe same or different groups may be 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, 2-ethylhexyl, trifluoromethyl, pentafluoroethyl, 2,2, 2-trifluoroethyl, vinyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl, ethynyl, propynyl, butynyl, pentynyl, hexynyl, or octynyl, R^aAnd R^bMore preferably C1-C12 alkyl groups, and examples of the C1-C12 alkyl groups 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, wherein methyl, ethyl, n-propyl, isopropyl are preferred, and R is^a、R^bMore preferably methyl.

R^a、R^bThe rings may be linked to form a ring structure, and may be interlinked to form a ring, and such rings are preferably five-membered rings and six-membered rings, and may be, for example, a ring structure in which a cyclohexane ring, cyclopentane, 2-biphenylene group are linked (a spiro-fluorene structure is formed at the X position).

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

Examples of the C1-C12 alkyl group includeExamples of the same above-mentioned aryl group having C6 to C30 include: phenyl, biphenyl, terphenyl, naphthyl, anthryl, phenanthryl, fluorenyl, pyrenyl,

Fluoro, anthryl, benzo [ a ]]Anthracenyl, benzo [ c ]]Phenanthryl, triphenylene, benzo [ k ]]Fluoranthenyl, benzo [ g ]]

Radical, benzo [ b]Triphenylene, picene, perylene, etc., of which phenyl and naphthyl are preferred, and phenyl is more preferred; specific examples of the heteroaryl group having C3 to C30 include: pyridyl, pyrimidinyl, pyrazinyl, pyridazinyl, triazinyl, quinolyl, isoquinolyl, naphthyridinyl, phthalazinyl, quinoxalinyl, quinazolinyl, phenanthridinyl, acridinyl, phenanthrolinyl, pyrrolyl, imidazolyl, pyrazolyl, triazolyl, tetrazolyl, indolyl, benzimidazolyl, indazolyl, imidazopyridinyl, benzotriazolyl, carbazolyl, furyl, thienyl, oxazolyl, thiazolyl, isoxazolyl, isothiazolyl, oxadiazolyl, thiadiazolyl, benzofuranyl, benzothienyl, benzoxazolyl, benzothiazolyl, benzisoxazolyl, benzisothiazolyl, benzooxadiazolyl, benzothiadiazolyl, dibenzofuranyl, dibenzothienyl, piperidyl, pyrrolidinyl, piperazinyl, morpholinyl, phenazinyl, phenothiazinyl, phenoxazinyl, and the like, but not limited thereto.

Preferred examples of the group of R include: benzene, naphthalene, anthracene, benzanthracene, phenanthrene, triphenylene, pyrene, perylene, fluoranthene, tetracene, pentacene, benzopyrene, biphenyl, idobenzene, terphenyl, tetrabiphenyl, fluorene, spirobifluorene, dihydrophenanthrene, dihydropyrene, tetrahydropyrene, cis-or trans-indenofluorene, triindene, isotridendene, spiroisotridendene, furan, benzofuran, isobenzofuran, dibenzofuran, thiophene, benzothiophene, isobenzothiophene, dibenzothiophene, pyrrole, indole, isoindole, carbazole, indolocarbazole, pyridine, quinoline, isoquinoline, acridine, phenanthridine, benzo-5, 6-quinoline, benzo-6, 7-quinoline, benzo-7, 8-quinoline, phenothiazine, phenoxazine, pyrazole, indazole, imidazole, benzimidazole, naphthoimidazole, phenanthroimidazole, pyridoimidazole, pentacene, terphenyl, thiophene, pyrazinoimidazole, quinoxaloimidazole, oxazole, benzoxazole, naphthoxazole, anthraoxazole, phenanthreneoxazole, isooxazole, 1, 2-thiazole, 1, 3-thiazole, benzothiazole, pyridazine, benzopyridazine, pyrimidine, benzopyrimidine, quinoxaline, 1, 5-diazanthracene, 2, 7-diazapyrene, 2, 3-diazapyrene, 1, 6-diazapyrene, 1, 8-diazapyrene, 4,5,9, 10-tetraaza, pyrazine, phenazine, phenoxazine, phenothiazine, fluoranthene, naphthyridine, azacarbazole, benzocaine, phenanthroline, 1,2, 3-triazole, 1,2, 4-triazole, benzotriazole, 1,2, 3-oxadiazole, 1,2, 4-oxadiazole, 1,2, 5-oxadiazole, phenanthroline, 1,2, 3-triazole, 1, 4-oxadiazole, 1, 5-oxadiazole, 1,3, 4-oxadiazole, 1,2, 3-thiadiazole, 1,2, 4-thiadiazole, 1,2, 5-thiadiazole, 1,3, 4-thiadiazole, 1,3, 5-triazine, 1,2, 4-triazine, 1,2, 3-triazine, tetrazole, 1,2,4, 5-tetrazine, 1,2,3, 4-tetrazine, 1,2,3, 5-tetrazine, purine, pteridine, indolizine and benzothiadiazole, or combinations thereof. More preferred groups as 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 substituted or unsubstituted C6-C30 aryl or substituted or unsubstituted C3-C30 heteroaryl, in particular, selected from substituted or unsubstituted C6-C30 aryl or heteroaryl represented by the general formula (A),

in the formula (A), L¹Independently represents a single bond, a substituted or unsubstituted C6-C30 arylene group, or a substituted or unsubstituted C3-C30 heteroarylene group, "+" represents the site of attachment to the parent nucleus, R¹Selected from C1-C20 alkyl, C1-C20 alkenyl, C1-C20 alkynyl, C1-C20 alkoxy, C6-C30 aryl, C3-C30 heteroaryl, multiple R¹Q is an integer of 0 to 7, preferably 0 or 1, and two R's in adjacent positions¹Can be connected to form a ring, such thatThe ring(s) may be aliphatic or aromatic, e.g. R in adjacent positions¹May be linked to form a ring structure such as a benzene ring or a fluorene ring.

X is selected from O, S, NR²、SiR³R⁴Preferably NR²、O、S；R²、R³、R⁴Each independently selected from C1-C12 alkyl, substituted or unsubstituted C6-C30 aryl or substituted or unsubstituted C3-C30 heteroaryl, R³And R⁴Can be interconnected to form a ring.

Examples of the substituted or unsubstituted aryl group having C6 to C30 include: naphthyl, phenanthryl, benzophenanthryl, fluoranthenyl, anthracyl, pyrene, dihydropyrene, fennel, perylene, fluoranthene, benzanthracene, triphenylene, naphthacene, pentacene, benzopyrene, furan, benzofuran, isobenzofuran, thiophene, benzothiophene, isobenzothiophene, pyridine, quinoline, isoquinoline, acridine, phenanthridine, benzo-5, 6-quinoline, benzo-6, 7-quinoline, benzo-7, 8-quinoline, phenothiazine, phenazine, pyrazole, indazole, imidazole, benzimidazole, naphthoimidazole, phenanthroimidazole, pyridoimidazole, pyrazinoimidazole, quinoxalimidazole, oxazole, benzoxazole, naphthooxazole, anthra oxazole, phenanthroizole, isoxazole, 1, 2-thiazole, 1, 3-thiazole, benzothiazole, pyridazine, benzopyridazine, pyrimidine, benzopyrimidine, quinoxaline, perylene, fluoranthene, perylene, pyridine, phenanthrene, pyrene, perylene, thiophene, perylene, Pyrazine, phenazine, naphthyridine, azacarbazole, benzocarbazine, phenanthroline, 1,2, 3-triazole, 1,2, 4-triazole, benzotriazole, 1,2, 3-oxadiazole, 1,2, 4-oxadiazole, 1,2, 5-administered oxadiazole, 1,3, 4-oxadiazole, 1,2, 3-thiadiazole, 1,2, 4-thiadiazole, 1,2, 5-thiadiazole, 1,3, 4-thiadiazole, 1,3, 5-triazine, 1,2, 4-triazine, 1,2, 3-triazine, tetrazole, 1,2,4, 5-tetrazine, 1,2,3, 4-tetrazine, 1,2,3, 5-tetrazine, purine, pteridine, indolizine and benzothiadiazole or combinations of these groups, which may also have corresponding substituents.

The above-mentioned "substituted or unsubstituted" means substituted by one or more groups selected from halogen and C₁～C₁₂Alkyl of (C)₁～C₁₂Alkoxy group of (C)₆～C₁₂Aryl of (C)₃～C₁₂Heteroaryl, cyano, hydroxy ofThe term "a linkage" - "which represents a ring structure" indicates that the substituent(s) in (1) is substituted, and that the linkage site is located at an arbitrary position on the ring structure where a bond can be formed.

C above₁～C₁₂Alkyl of (C)₆～C₁₂Aryl of (C)₃～C₁₂As examples of the heteroaryl group in (1), the same ones as those mentioned above can be cited, and examples of the C1-C12 alkoxy group include groups obtained by linking the above-mentioned examples of the C1-C12 alkyl group with-O-, for example, methoxy group, ethoxy group, propoxy group, butoxy group, pentoxy group, hexoxy group, heptoxy group, octoxy group, nonoxy group, decyloxy group, undecyloxy group, dodecyloxy group and the like, and among them, methoxy group, ethoxy group, propoxy group and more preferably methoxy group are preferable.

For the compound, the mother nucleus of the combination of fluorene and 2, 4-diphenylaniline is a main structure, and the compound can be ensured to have good hole transport performance or electron blocking performance by the defined substituent group with a special structure. The high steric hindrance of the 2, 4-diphenyl benzene directly influences the charge transport performance of the compound, so that charges are transferred more smoothly in molecules, and the self-assembly property during film formation is more favorable for intermolecular charge transport due to the high steric hindrance.

On the other hand, the 2 and 4 positions of aniline in the mother nucleus are substituted to increase the thermal stability of molecules and reduce the possibility of oxidation of the molecules, so that the service life of the device is prolonged, and meanwhile, the introduction of a 2-position substituent can increase the steric hindrance between the molecules, so that the molecules are prevented from clustering, film formation during evaporation is facilitated, the potential energy between contact interfaces of film layers is reduced, and charge transfer is facilitated. Therefore, the charge transfer efficiency can be improved and the service life can be prolonged.

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

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

The first electron blocking layer material and the second electron blocking layer host material may also be materials that are generally used as hole transport regions. For example, compounds represented 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 compound used as the organic material layer may be an organic small molecule, an organic large molecule, and a polymer, and a combination 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 containing only one compound and a single layer containing a plurality of compounds. The hole transport region may also be a multilayer structure including at least 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 polymers containing conductive dopants such as polyphenylenevinylene, polyaniline/dodecylbenzenesulfonic acid (Pani/DBSA), poly (3, 4-ethylenedioxythiophene)/poly (4-styrenesulfonate) (PEDOT/PSS), polyaniline/camphorsulfonic acid (Pani/CSA), polyaniline/poly (4-styrenesulfonate) (Pani/PSS), aromatic amine derivatives such as compounds shown below in HT-1 to HT-34; or any combination thereof.

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 compounds of HT-1 to HT-34 described above, or one or more compounds of HI-1 to HI-3 described below; one or more of the following HI-1 to HI-3 compounds 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.

An electron injection layer may also be included in the device between the electron transport layer and the cathode, the electron injection layer material including, but not limited to, combinations of one or more of the following: LiF, NaCl, CsF, Li₂O、Cs₂CO₃、BaO、Na、Li、Ca。

In yet another aspect, there is also provided a method of making 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 main 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 barrier layer material to form a first electron barrier layer;

s3: forming a light emitting layer; and

s4: a cathode is formed.

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

The evaporation is carried out under vacuum, the vacuum degree is generally pumped to 1 × 10^-5～9×10^-3Pa is evaporated. 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 including a plurality of light emitting regions includes a plurality of pixel units distributed in an array, as shown in the figure, each pixel unit includes one or more of a red pixel unit, a green pixel unit, a blue pixel unit and a yellow pixel unit, and each pixel unit includes a common layer arranged in a stacked manner: one or more 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 layers in 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, and 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

The present invention will be described in further detail below with reference to specific embodiments in order to make the present invention better understood by those skilled in the art.

Compounds of synthetic methods not mentioned in the examples are all starting products obtained commercially. Basic chemical raw materials such as petroleum ether, ethyl acetate, toluene, tetrahydrofuran, N-dimethylformamide, methylene chloride, cesium carbonate, potassium carbonate, palladium acetate, 2-dicyclohexylphosphine-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-biphenylboronic acid, sodium tert-butoxide, and the like, which are used in examples, are commercially available in domestic chemical product markets.

Analytical testing of intermediates and compounds in the present invention used an ABCIEX mass spectrometer (4000QTRAP) and Brookfield nuclear magnetic resonance spectrometer (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 prepared by the steps of firstly carrying out Suzuki reaction on 2, 4-dibromoaniline and phenylboronic acid to obtain an intermediate 2, 4-diphenylaniline, then carrying out reaction on the intermediate and 2-bromo-9, 9-dimethylfluorene to obtain an intermediate A-1, and then carrying out Buchwald-Hartwig coupling reaction on a halide and the intermediate A-1.

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

synthesis of intermediate A-2

The intermediate A-2 can be used for synthesizing the compound of the general formula (I-1), and the compound of the general formula (I-2) can be obtained similarly based on the same principle, and other homologues can be obtained based on the similar synthetic method.

Synthesis of A-1:

in a four-neck flask equipped with a condenser tube, raw materials of 2, 4-dibromoaniline (50g, 199mmol), phenylboronic acid (54g, 438mmol) and potassium carbonate (83g, 598mmol) are added into a mixed solvent of Tetrahydrofuran (THF) (600mL) and water (300mL), the mixture is stirred uniformly, and then Pd (PPh) is added under the protection of nitrogen gas₃)₄(9.2g, 7.97mmol), heated to 70 ℃ and reacted for 18 h. After cooling to room temperature, 500mL of water is directly added for liquid separation, the water phase is extracted twice by 300mL of ethyl acetate, the organic phases are combined, dried by anhydrous sodium sulfate and concentrated to obtain a crude product. Purifying the crude product by column chromatography (PE/EA, 5/1) to obtain light yellow powder 38 g;

synthesis of A-2:

a-1(38g, 135 mmol), 2-bromo-9, 9-dimethylfluorene ((41g, 148mmol), sodium tert-butoxide (32.4g, 337mmol), toluene (500mL) were added to a four-necked flask equipped with a condenser tube, and Pd (dppf) Cl was added thereto under nitrogen protection₂(1.5g, 2.02mmol) and SPhos (1.7g, 4.05mmol), the reaction solution was heated to 100 ℃ and reacted for 18 h. Cooling to room temperature, adding 250mL saturated salt solution, separating, extracting the water phase with 200mL ethyl acetate for three times, mixing the organic phases, drying with anhydrous sodium sulfate, and concentrating to obtainAnd (5) obtaining a crude product. The crude product was purified by silica gel column chromatography (PE/EA, 10/1) to obtain 45g of a pale yellow solid.

General Synthesis of Compounds of formula

Synthesis example 1

Synthesis of Compound-1

Synthesis of intermediate M1

In a four-mouth bottle equipped with a condenser tube, raw materials of 4-dibenzothiophene borate (40g, 175mmol), bromobenzene (33g, 211mmol) and potassium carbonate (36g, 263mmol) are added into a mixed solvent of toluene (500mL), ethanol (100mL) and water (100mL), the mixture is stirred uniformly, and then Pd (PPh) is added under the protection of nitrogen gas₃)₄(4.1g, 3.51mmol) and heated to 100 ℃ for 18 h. After cooling to room temperature, 300mL of saturated saline solution is directly added for liquid separation, the water phase is extracted twice by 300mL of ethyl acetate, the organic phases are combined, dried by anhydrous sodium sulfate and concentrated to obtain a crude product. The crude product was purified by silica gel column chromatography (PE/DCM, 20/1) to give 30g of a white powder;

synthesis of intermediate M2

A fully dried compound M1(20g, 76.8mmol) was charged into a dry three-necked flask equipped with a constant pressure dropping funnel, low temperature thermometer. Anhydrous tetrahydrofuran (300mL) was added, the mixture was stirred to dissolve the compound, and then the reaction system was cooled to-78 ℃ by a liquid nitrogen-ethanol bath under nitrogen protection. Then, s-BuLi (71mL, 1.3M,92.2mmol) is dripped through a constant pressure dropping funnel, the dripping speed is controlled to keep the temperature of the reaction system between-60 ℃ and-70 ℃, and the temperature is kept for 30min after the dripping is finished, so that the solution is mauve. 1, 2-dibromoethane (18.8g, 99.9mmol) was dissolved in THF (100mL), and the solution was gradually yellow by dropwise addition, after dropwise addition, the temperature was naturally raised to room temperature, and stirring was carried out for 4 hours. The reaction system was poured into 300mL of saturated brine, extracted twice with ethyl acetate (200mL), the organic phases were combined, dried over anhydrous sodium sulfate, and concentrated to give 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 tube, raw material M2(17g, 50mmol), p-chlorobenzoic acid (9.4g, 60mmol) and potassium carbonate (10.4g, 75.2mmol) were added to a mixed solvent of toluene (200mL), ethanol (50mL) and water (50mL), stirred uniformly, and then Pd (PPh) was added under nitrogen protection₃)₄(0.6g, 0.5mmol) and heated to 100 ℃ for 18 h. After cooling to room temperature, 300mL of saturated brine was added directly for liquid separation, 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 silica gel column chromatography (PE/DCM, 20/1) to give 10g of a white powder;

synthesis of Compound-1

Intermediate A-2(10g, 22.8mmol), M3(10.2g, 27.4mmol) and sodium tert-butoxide (2.9g, 29.7mmol) were placed in a three-necked flask, 100mL of toluene solvent was added and stirred uniformly, and catalyst Pd2(dba)3(209mg, 0.228mmol) and SPhos (188mg, 0.457mmol) were added under nitrogen. Heating to 110 ℃, gradually making the solution brown red, and keeping the temperature for reaction overnight. Cooling, pouring into 200mL water, extracting with EA (200 mL. multidot.2), combining organic phases, drying with sodium sulfate, concentrating to obtain brown oil, purifying crude product with column chromatography to obtain PE/DCM, 5/1), and concentrating to obtain light yellow solid. The product was recrystallized from a mixed solvent of n-hexane and toluene (15/1) to give 10g of a 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 (20g, 76mmol), p-chlorobenzeneboronic acid (14.3g, 91mmol), and potassium carbonate (15.8g, 114mmol) were added to toluene (200mL) and ethyleneAlcohol (50mL) and water (50mL) are mixed and stirred uniformly, and then Pd (PPh) is added under the protection of nitrogen₃)₄(0.9g, 0.76mmol) and heated to 100 deg.C for 18 h. After cooling to room temperature, 300mL of saturated brine was added directly for liquid separation, 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 pale yellow solid. Recrystallizing the crude product by using methanol and dichloromethane to obtain 10g of white solid;

synthesis of Compound-3

Synthesis of Compound-3 referring to Compound-1, intermediate M4 was substituted 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

The synthesis of compound-2 is the same as the synthesis of compound-1. Intermediate M5 was used as the starting material in place of M3 to give a pale yellow solid.

Synthesis example 4

Synthesis of Compound-5

Synthesis of intermediate M6

Adding N-phenyl-3-bromocarbazole (70g, 218mmol), p-chlorobenzoic acid (41g, 260mmol) and potassium carbonate (45g, 325mmol) into a mixed solvent of THF (700mL) and water (100mL) in a four-mouth bottle equipped with a condenser tube, stirring uniformly, and then adding Pd under the protection of nitrogen₂₍dba)₃(1.26g, 1.38mmol), heated to 60 ℃ and reacted for 18 h. Cooling to room temperatureThen, 500mL of saturated brine was added directly for liquid separation, the aqueous phase was extracted twice with 500mL of ethyl acetate, and 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 synthesis of 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

In a four-necked flask equipped with a condenser tube, 3-bromofluoranthene (20g, 71mmol), p-chlorophenylboronic acid (12.3g, 78mmol) and potassium carbonate (12.9g, 92.5mmol) were added to a mixed solvent of THF (350mL) and water (50mL), stirred well, and then Pd (PPh) was added under nitrogen protection₃)₄(822mg, 0.71mmol), heated to 100 ℃ and reacted for 18 h. After cooling to room temperature, 300mL of saturated brine was added directly for liquid separation, 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 pale yellow solid. Recrystallizing the crude product by using methanol and dichloromethane to obtain 16g of yellow solid;

synthesis of Compound-6

Referring to the synthesis of 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

Adding carbazole (20g, 120mmol), 4-bromo-2-chloro-1-fluorobenzene (30g, 144mmol), cesium carbonate (30g, 155mmol) and DMF (400mL) into a three-neck flask, heating to 100 ℃ under the protection of nitrogen, stirring for reaction for 20 hours, pouring the reaction liquid into 500mL of saturated saline solution after cooling, extracting twice with 300mL of ethyl acetate, combining organic phases, drying with anhydrous sodium sulfate, concentrating, and purifying a crude product by silica gel column chromatography (PE/EA, 7/1) to obtain 30g of a white solid.

Synthesis of intermediate M9

In a four-necked flask equipped with a condenser tube, M8(20g, 56mmol), phenylboronic acid (8.2g, 67mmol), and potassium carbonate (10g, 73mmol) were added to a mixed solvent of toluene (300mL), ethanol (150mL), and water (150mL), stirred well, and then Pd (PPh) was added under nitrogen protection₃)₄(1.3g, 1.12mmol), heated to 100 ℃ and reacted for 18 h. After cooling to room temperature, 300mL of saturated brine was added directly for liquid separation, 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 pale yellow solid. The crude product was purified by silica gel column to obtain 11g of a yellow solid.

Synthesis of Compound-16

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

Synthesis example 7

Synthesis of Compound-250

Analogous compound-250 is obtained by the following synthetic route

The specific synthesis method can be referred to the synthesis conditions of the compound-1. A pale yellow solid was obtained.

Synthesis example 8

Synthesis of Compound-248

The specific synthesis method can be referred to the synthesis conditions of the compound-1. A yellow solid was obtained.

By replacing different Ar-X₂(sometimes referred to in the art as aryl halides) different target compounds can be obtained. It should be noted that the above synthetic method uses Buchwald-Hartwig coupling to link intermediate M to intermediate A-2, but is not limited to this coupling method, and those skilled in the art may select other methods, such as but not limited to Stille coupling method, Grignard reagent method, Kumada-Tamao, etc., and any equivalent synthetic method may be used to realize the linking of substituent A₁And A₂The purpose of the attachment to the benzopyrene ring may be selected as desired.

Device comparative example 1

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

The preparation process of the organic electroluminescent device in the comparative example is as follows:

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

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

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

a second electron blocking layer is evaporated on the hole transport layer in vacuum, 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 adjusted to be 0.1nm/s by using 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 80 nm;

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

a luminescent layer of the device is vacuum evaporated on the first electron blocking layer, the luminescent layer comprises a main material and a dye material, the evaporation rate of the main material RH-1 is adjusted to be 0.1nm/s by using 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 40 nm;

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

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

Device comparative example 2

This comparative example is different from comparative example 1 of the device only in that a second electron blocking layer comprising a host material compound-1 and a guest material HI-1 was vacuum-evaporated on the hole transport layer, and the evaporation rate of the host material compound-1 was adjusted to 0.1nm/s by a multi-source co-evaporation method, the evaporation rate of the guest material HI-1 was set at a rate of 1% of the evaporation rate of the host material, and the total thickness of the evaporated film was 80 nm.

And (3) vacuum-evaporating a material compound-1 on the second electron blocking layer to be used 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 4 nm.

Device comparative example 3

And (3) vacuum-evaporating a material compound-1 on the second electron blocking layer to be used 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 65 nm.

Device comparative example 4

This comparative example is different from comparative example 1 of the device only in that a second electron blocking layer including a host material compound-1 and a guest material HI-1 was vacuum-evaporated on the hole transport layer, and the evaporation rate of the host material compound-1 was adjusted to 0.1nm/s, the evaporation rate of the guest material HI-1 was set at a rate of 1% of the evaporation rate of the host material, and the total film thickness of the evaporated film was 35nm by a multi-source co-evaporation method.

And (3) vacuum-evaporating a material compound-1 on the second electron blocking layer to be used 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 40 nm.

Device comparative example 5

This comparative example is different from comparative example 1 of the device only in that a second electron blocking layer including a host material compound-1 and a guest material HI-1 was vacuum-evaporated on the hole transport layer, and the evaporation rate of the host material compound-1 was adjusted to 0.1nm/s by a multi-source co-evaporation method, the evaporation rate of the guest material HI-1 was set at a rate of 1% of the evaporation rate of the host material, and the total thickness of the evaporated film was 105 nm.

Device comparative example 6

This comparative example is different from comparative device example 1 only in that the second electron blocking layer was vacuum-deposited on the hole transport layer and comprised only the host material compound-1, the deposition rate of the host material compound-1 was adjusted to 0.1nm/s, and the total film thickness of the deposition was adjusted to 80 nm.

Device comparative example 7

This comparative example is different from comparative device example 1 only in that the first electron blocking layer was directly vapor-deposited on the hole transport layer by vacuum vapor deposition, and only the host material compound-1 was included, the vapor deposition rate of the host material compound-1 was adjusted to 0.1nm/s, and the total vapor deposition film thickness was adjusted to 40 nm.

Device comparative example 8

And (3) performing vacuum evaporation on a light-emitting layer of the device on the second electron blocking layer, wherein the light-emitting layer comprises a main material and a dye material, the evaporation rate of the main material RH-1 is adjusted to be 0.1nm/s by using 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 40 nm.

Device comparative example 9

This comparative example is different from comparative device example 1 only in that a second electron blocking layer comprising host compound-1 and guest compound HI-1 was vacuum-evaporated on the hole transporting layer, and the evaporation rate of the host compound-1 was adjusted to 0.1nm/s, the evaporation rate of the guest compound HI-1 was set at a rate of 0.5% of the evaporation rate of the host compound, and the total thickness of the evaporated film was 80nm by a multi-source co-evaporation method.

Device comparative example 10

This comparative example is different from 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-evaporated on the hole transporting layer, and the evaporation rate of the host material compound-1 was adjusted to 0.1nm/s, the evaporation rate of the guest material HI-1 was set at a rate of 10% of the evaporation rate of the host material, and the total thickness of the evaporated film was 80nm by a multi-source co-evaporation method.

Device comparative example 11

The difference between the present comparative example and comparative device 1 is that a second electron blocking layer, which includes a host material HT4 and a guest material HI-1, was vacuum-evaporated on the hole transport layer, and the evaporation rate of the host material HT4 was adjusted to 0.1nm/s by a multi-source co-evaporation method, the evaporation rate of the guest material HI-1 was set to 1% of the evaporation rate of the host material, and the total thickness of the evaporated film was 80 nm.

And vacuum evaporating a material HT4 on the second electron barrier layer to form a first electron barrier layer of the device, wherein the evaporation rate is 0.1nm/s, and the total evaporation film thickness is 40 nm.

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 the embodiment is as follows:

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

Device example 2

The difference between this example and the device example 1 is only that the evaporation rate ratio of the host material to the guest material in the second electron blocking layer is 1:0.02, and the thickness is not changed.

Device example 3

The difference between this example and the device example 1 is only that the evaporation rate ratio of the host material to the guest material in the second electron blocking layer is 1:0.03, and the thickness is not changed.

Device example 4

The difference between this example and the device example 1 is only that the evaporation rate ratio of the host material to the guest material in the second electron blocking layer is 1:0.09, and the thickness is not changed.

Device example 5

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

Device example 6

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

Device example 7

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

Device example 8

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

Device example 9

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

Device example 10

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

Device example 11

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

Device example 12

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

Device examples 13 to 24

Organic electroluminescent devices were prepared according to the method shown in table 1, following device example 1.

Preparing a device containing light emitting areas with different colors:

device example 25

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

and (3) evaporation of blue light pixel points: evaporating by using a fine mask plate, and evaporating a compound-1 as a first electron barrier layer of the device on the hole transport layer in vacuum at the evaporation rate of 0.1nm/s and the total film thickness of 50 nm; vacuum evaporation is carried out on the blue light emitting layer of the first light emitting area on the first electronic barrier layer, 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 adjusted 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 30 nm;

evaporation of red light (yellow light) pixel points:

evaporating a second electron layer by using a fine mask, wherein the second electron blocking layer comprises a host material and an object material, the materials and the proportion are the same as those in the embodiment 1, and the evaporation thickness is 80 nm; then, evaporating the first electron barrier layer by using a fine mask plate, wherein the evaporation rate is 0.1nm/s, and the total film thickness of evaporation is 50 nm; continuing to use a fine mask plate to evaporate a second light emitting region, and evaporating a red (yellow) light emitting layer on the first electron blocking layer in vacuum, wherein the red (yellow) light emitting layer comprises a red (yellow) light main body compound RH-1 and a red (yellow) light dye material RPD-1(YPD-1), the evaporation rate of the red (yellow) light main body compound RH-1 is adjusted to be 1nm/s, 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 body compound, and the total evaporation film thickness is 30 nm;

and (3) evaporation of green light pixel points: evaporating a second electron blocking layer by using a fine mask, wherein the second electron blocking layer comprises a host material and an object material, the materials and the proportion are the same as those in the embodiment 1, and the evaporation thickness is 60 nm; then, evaporating the first electron barrier layer by using a fine mask plate, wherein the evaporation rate is 0.1nm/s, and the total film thickness of evaporation is 50 nm; continuously using a fine mask to evaporate a third light emitting region to evaporate a green light emitting layer in vacuum, wherein the third light emitting region comprises a green light main compound GPH-1 and a green light dye material GPD-1, adjusting the evaporation rate of the green light main compound GPH-1 to be 1nm/s by using a multi-source co-evaporation method, setting the evaporation rate of the green light dye material GPD-1 according to the proportion of 5% of the evaporation rate of the main compound, and setting the total evaporation film thickness to be 30 nm;

after the evaporation of the luminous layers in the three regions is finished, switching to a through hole mask plate, and continuing to perform vacuum evaporation on an electron transport layer material ET-1 of the device, wherein the evaporation rate is 0.1nm/s, and the total evaporation film thickness is 30 nm;

Examples 26 to 34

Organic electroluminescent devices were prepared according to the method described in example 25, and 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 an object material, and the evaporation thickness is 70 nm.

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 region comprises a host material and an object material, and the evaporation thickness is 90 nm;

the second electron blocking layer of the third light emitting region comprises a host material and an object material, and the evaporation thickness is 90 nm.

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

the driving voltage and current efficiency of the organic electroluminescent devices prepared in examples 1 to 24 and comparative examples 1 to 11 and the lifetime of the devices were measured at the same luminance using a digital source meter and a luminance meter. Specifically, the voltage was raised at a rate of 0.1V per second, and it was determined that the luminance of the organic electroluminescent device reached 100cd/m²The current density is measured at the same time as the driving voltage; the ratio of the brightness to the current density is the current efficiency; the life test of LT90 is as follows: using a luminance meter at 5000cd/m²At luminance, the luminance drop of the organic electroluminescent device was measured to be 4500cd/m while maintaining a constant current²Time in hours.

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

TABLE 1 Performance of organic electroluminescent devices of examples 1 to 24 and comparative examples 1 to 11

The required luminance in examples 25 to 34 and comparative examples 12 to 13 was 100cd/m²The device performance is shown in table 2, and the data in table 2 are relative values based on (1, 1) of comparative example 12.

TABLE 2 Performance of organic electroluminescent devices of examples 25 to 34 and comparative examples 12 to 13

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

TABLE 3 organic electroluminescent host Material Properties

Material	HOMO	LUMO	Mobility ratio	T1
					Compound-1	-5.22	-1.72	8.33×10^-5cm²/Vs	2.8
Compound 8	-5.20	-1.75	9.62×10^-5cm²/Vs	/
					Compound 90	-5.21	-1.73	8.62×10^-5cm²/Vs	/
HI-1	-7.74	-5.34	/	/
					BFH-1	-5.38	-2.25	/	2.6

The above results show that, in the novel device structure of the present invention, by introducing the electron blocking layer, the electron blocking layer comprises the first electron blocking layer and the second electron blocking layer, wherein 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, when the novel device structure is used for a device and a display device, the novel device structure can not only block excess electrons transmitted from one side of the light emitting layer, thereby effectively improving the device efficiency, but also reduce the phenomena of guest material quenching and the like through the double-layer arrangement. Therefore, the rising and falling voltage can be effectively reduced, and the current efficiency is improved.

According to the embodiment of the invention, it can be seen that the electron blocking layer is configured to include the first electron blocking layer and the second electron blocking layer, wherein the second electron blocking layer includes the host material and the guest material, so that the voltage of the device can be reduced by at most about 40%, and the current efficiency can be improved by more than about 30%.

The applicant states that the present invention is illustrated by the above embodiments of the 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 rely on the above embodiments to be practiced. It will be apparent to those skilled in the art that any modification of the present invention, equivalent substitutions of selected materials and additions of auxiliary components, selection of specific modes and the like, which are within the scope and disclosure of the present invention, are contemplated by the present invention.

The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.

It should be noted that the various technical features described in the above embodiments can be combined in any suitable manner without contradiction, and the invention is not described in any way for the possible combinations in order to avoid unnecessary repetition.

In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.

Claims

1. An organic electroluminescent device 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 main material and a second electron blocking layer guest material.

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

3. The organic electroluminescent device according to claim 1, wherein the molar ratio of the second electron blocking layer host material to the second electron blocking layer guest material is 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 is 5-60nm, preferably 5-40nm thick and the second electron blocking layer is 40-100nm, preferably 60-100nm thick.

5. The organic electroluminescent device according to any one of claims 1 to 4, 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 80-100 nm; when the light-emitting region is a green light-emitting region, the thickness of the second electron blocking layer is 60-80 nm; when the light-emitting region is a yellow light-emitting region, the thickness of the second electron blocking layer is 70-90 nm.

7. The organic electroluminescent device according to any one of claims 1 to 6, comprising a plurality of light-emitting regions, at least one of which is a blue light-emitting region, the electron blocking layer of which is composed of the first electron blocking layer.

8. The organic electroluminescent device according to claims 1 to 7, wherein the first electron blocking layer material and the second electron blocking layer host material are the same material.

9. The organic electroluminescent device according to any one of claims 1 to 8, wherein the first electron blocking layer material and/or the second electron blocking layer host material is selected from compounds of 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^bthe same or different, each is independently selected from alkyl of C1-C20, alkenyl of C1-C20, alkynyl of C1-C20, R^a、R^bR is selected from alkyl of C1-C20, alkenyl of C1-C20, alkynyl of C1-C20, alkoxy of C1-C20, aryl of C6-C30 and heteroaryl of C3-C30,

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

in the formula (A), the compound (A),

L¹independently represents a single bond, a substituted or unsubstituted C6-C30 arylene group, or a substituted or unsubstituted C3-C30 heteroarylene group, "-" represents a site of attachment to the parent nucleus,

R¹selected from C1-C20 alkyl, C1-C20 alkenyl, C1-C20 alkynyl, C1-C20 alkoxy, C6-C30 aryl, C3-C30 heteroaryl, multiple R¹Identical or different, two R in adjacent position¹May be linked to form a ring; q is an integer of 0 to 7, preferably 0 or 1,

x is selected from O, S, NR²、SiR³R⁴；R²、R³、R⁴Each independently selected from C1-C12 alkyl, substituted or unsubstituted C6-C30 aryl or substituted or unsubstituted C3-C30 heteroaryl, R³And R⁴Can be interconnected to form a ring,

the above-mentioned "substituted or unsubstituted" means substituted by one or more groups selected from halogen and C₁～C₁₂Alkyl of (C)₁～C₁₂Alkoxy of (2)Base, C₆～C₁₂Aryl of (C)₃～C₁₂The heteroaryl group, cyano group or hydroxyl group in (1) is substituted, and a connecting bond between the substituents "-" represents a ring structure, and represents a connecting site at an arbitrary position on the ring structure where a bond can be formed.

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

11. an organic electroluminescent device according to any one of claims 1 to 10, 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 11, 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. An organic light-emitting device comprising the organic electroluminescent element as claimed in any one of claims 1 to 12.

14. A method of making an organic electroluminescent device as claimed in any one of claims 1 to 12, comprising the steps of:

s1: forming an anode;

s2: forming an electron blocking layer comprising:

s3: forming a light emitting layer; and

s4: a cathode is formed.

15. The method according to claim 14, 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 to 1: 0.09.