Composition and organic electroluminescent device

Abstract

The invention provides a composition and an organic electroluminescent device. The composition comprises at least one first compound and at least one second compound; the first compound has a structure as shown in a formula I, and the second compound has a structure as shown in a formula II. The composition with specific composition is obtained by selecting the first compound with the specific structural formula and the second compound with the specific structural formula for cooperative use, and the organic electroluminescent device prepared by taking the composition as the main body material of the luminescent layer has excellent performance.

Description

Technical Field

[0001] The invention belongs to the technical field of organic electroluminescent materials, and in particular relates to a composition and an organic electroluminescent device. Background Art

[0002] With the rapid development of science and technology and information technology, people have also put forward new goals and requirements for the performance of information display systems. Displays with high brightness, high resolution, wide viewing angle and low energy consumption have become a research hotspot. Organic electroluminescent (OLED) display technology can meet the above needs of people. At the same time, it has other advantages such as a wide operating temperature and flexible display. Therefore, it has become the new darling of the new generation of flat-panel displays after CRT (cathode ray tube) displays, LCD (liquid crystal display) and PDP (plasma display) flat-panel displays. At present, organic electroluminescent (OLED) display technology has been applied in smart phones, tablet computers and other fields, and has expanded to large-size application fields such as televisions.

[0003] In the past 30 years of development, different designs of organic electroluminescent device structures, optimization of organic electroluminescent device life, efficiency and other performance, and various OLED materials with excellent performance have attracted extensive attention and research. This field is in urgent need of developing more types of materials with higher performance to meet people's higher requirements for OLED devices. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention aims to provide a composition and an organic electroluminescent device. In the present invention, a first compound having a specific structural formula and a second compound having a specific structural formula are selected and used in combination to obtain a composition having a specific composition, and the composition is used as the main material of the light-emitting layer, so that the prepared organic electroluminescent device has excellent performance.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a composition comprising at least one first compound and at least one second compound;

[0007] The first compound has a structure shown in the following formula I:

[0008]

[0009] Among them, Ar 21 ,Ar 22 Each independently selected from any one or a combination of at least two of phenyl, diphenyl, terphenyl, quaterphenyl and naphthyl;

[0010] Ar 23Any one selected from a single bond, a phenylene group, a naphthylene group, a biphenylene group, a terphenylene group or a quaterphenylene group;

[0011] The second compound has a structure shown in the following formula II:

[0012]

[0013] Among them, Ar 31 ,Ar 32 ,Ar 33 Each is independently selected from any one of a single bond, a phenylene group, a biphenylene group, a terphenylene group, a quaterphenylene group or a naphthylene group;

[0014] X1-X6 are each independently selected from N or CR5, and at least one of X1-X6 is selected from N;

[0015] R1 to R5 are each independently any one of H, phenyl, biphenyl, terphenyl, quaterphenyl, and naphthyl, or a combination of at least two thereof;

[0016] The hydrogen atoms in the first compound and the second compound may each independently be substituted with a deuterium atom (D).

[0017] In the present invention, a composition with a specific composition is obtained by selecting a first compound with a specific structural formula and a second compound with a specific structural formula for use in combination, and the composition is used as the main material of the light-emitting layer. The prepared organic electroluminescent device has a lower driving voltage, a higher current efficiency and a longer life.

[0018] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the objectives and beneficial effects of the present invention can be better achieved and realized.

[0019] As a preferred technical solution of the present invention, the first compound is selected from the compound represented by formula I-1 or the compound represented by formula I-2:

[0020]

[0021] Among them, Ar 21 ,Ar 22 Each independently selected from any one or a combination of at least two of phenyl, diphenyl, terphenyl, quaterphenyl and naphthyl;

[0022] The hydrogen atoms in the compound represented by formula I-1 or the compound represented by formula I-2 may each independently be replaced by a deuterium atom.

[0023] Preferably, Ar in the first compound 21 ,Ar22 The hydrogen atoms in the ions are each independently replaced by deuterium atoms.

[0024] Preferably, the first compound is selected from the compound represented by formula I-1-D or the compound represented by formula I-2-D:

[0025]

[0026] Among them, Ar 21 ,Ar 22 Each is independently selected from any one or a combination of at least two of phenyl, biphenyl, terphenyl, quaterphenyl and naphthyl.

[0027] It should be noted that in the compound represented by formula I-1-D or the compound represented by formula I-2-D, (D)4 indicates that the four hydrogen atoms on the corresponding benzene ring are replaced by deuterium atoms. Similarly, (D)3 indicates that the three hydrogen atoms on the corresponding benzene ring are replaced by deuterium atoms. In the compound represented by formula I-1-D or the compound represented by formula I-2-D, Ar 21 ,Ar 22 There are no deuterium atoms in the groups.

[0028] As a preferred technical solution of the present invention, the Ar 21 ,Ar 22 The sum of the number of benzene rings in is selected from an integer ≥ 4, for example, it can be 4, 5, 6, 7 or 8.

[0029] Preferably, the Ar 21 is phenyl, the Ar 22 Any one selected from diphenyl, terphenyl or quaterphenyl.

[0030] Preferably, the Ar 21 is a diphenyl group, wherein Ar 22 Selected from diphenyl or terphenyl.

[0031] As a preferred technical solution of the present invention, the first compound is selected from any one of the following substituted or unsubstituted compounds:

[0032]

[0033]

[0034] The substitution means that the hydrogen atoms in the above compounds can each be independently replaced by a deuterium atom.

[0035] Preferably, the first compound is selected from any one of the following substituted or unsubstituted compounds H-1 to H-28, H101 to H105, H-17o, H-17m, H-101 to H-106:

[0036]

[0037]

[0038]

[0039] The substitution means that the hydrogen atoms in the above compounds can each be independently replaced by a deuterium atom.

[0040] Preferably, the first compound is selected from any one of the following compounds:

[0041]

[0042]

[0043] As a preferred technical solution of the present invention, the Ar 33 is selected from phenylene or a single bond.

[0044] Preferably, X1 to X3 are all selected from N.

[0045] Preferably, X1 to X6 are all selected from N.

[0046] Preferably, X1-X3 are all selected from N, and X4-X6 are each independently selected from CR5;

[0047] The R5 has the same protection scope as above.

[0048] Preferably, R1 and R2 are each independently selected from phenyl or biphenyl.

[0049] As a preferred technical solution of the present invention, the second compound is selected from the compound represented by formula II-1:

[0050]

[0051] Among them, Ar 31 ,Ar 32 ,Ar 33 , X1~X6, R1~R5 have the same protection scope as above.

[0052] As a preferred technical solution of the present invention, the second compound is selected from any one of the following substituted or unsubstituted compounds:

[0053]

[0054]

[0055]

[0056]

[0057] The substitution means that the hydrogen atoms in the above compound can be independently replaced by deuterium atoms.

[0058] Preferably, the second compound is selected from any one of the following substituted or unsubstituted compounds:

[0059]

[0060]

[0061] The substitution means that the hydrogen atoms in the above compound can be independently replaced by deuterium atoms.

[0062] It should be noted that the present invention does not impose any special limitation on the preparation methods of the first compound and the second compound, and any preparation methods commonly used in the art are applicable.

[0063] In a second aspect, the present invention provides an organic electroluminescent device, the organic electroluminescent device comprising an anode, a cathode and an organic thin film layer disposed between the anode and the cathode;

[0064] The material of the organic thin film layer includes the composition described in the first aspect.

[0065] Preferably, the organic thin film layer includes a hole layer and a light-emitting layer;

[0066] The host material of the light-emitting layer includes the composition described in the first aspect.

[0067] As a preferred technical solution of the present invention, the organic thin film layer includes a hole layer and a light-emitting layer, the light-emitting layer includes the compound as described in the first aspect, the hole layer includes an electron blocking layer, and the material of the electron blocking layer includes a compound having a structure shown in the following formula A:

[0068]

[0069] Among them, R 601 Any one selected from tert-butyl substituted phenyl, methylcyclopentyl substituted phenyl, methylcyclohexyl substituted phenyl, methylcyclopentyl, methylcyclohexyl or tert-butyl;

[0070] Ring A and Ring B are each independently selected from a benzene ring or a naphthalene ring;

[0071] Ar 601 is selected from phenyl, naphthyl, phenylene or naphthylene;

[0072] m, n, and p are each independently selected from 0 or 1;

[0073] The hydrogen atoms in the compounds of formula A may each independently be replaced by a deuterium atom.

[0074] It should be noted that when m is 1 and n is 1, Ar 601 is selected from phenylene or naphthylene; when m is 0 and n is 1, Ar 601 Selected from phenyl or naphthyl.

[0075] Preferably, the compound of formula A is selected from any one of the following substituted or unsubstituted compounds:

[0076]

[0077]

[0078] The substitution means that the hydrogen atoms in the above compounds can each be independently replaced by a deuterium atom.

[0079] Compared with the prior art, the present invention has the following beneficial effects:

[0080] (1) In the present invention, a composition having a specific composition is obtained by selecting a first compound having a specific structure and a second compound having a specific structure for use in combination, and the composition is used as the main material of the light-emitting layer. The prepared organic electroluminescent device has a lower driving voltage, a higher current efficiency and a longer life.

[0081] (2) In the present invention, the composition of the first compound and the second compound is used as the main material of the light-emitting layer, and the compound of formula A is used as the electron blocking layer material, which can further improve the performance of the organic electroluminescent device. DETAILED DESCRIPTION

[0082] For the convenience of understanding the present invention, the present invention lists the following embodiments. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0083] The specific structures of the compounds used in the following device examples and device comparative examples are as follows:

[0084]

[0085]

[0086] Device Example 1

[0087] This device embodiment provides an organic electroluminescent device, and the composition provided by the present invention is selected as the green light host material in the organic electroluminescent device. The specific composition of the composition is shown in Table 1 below.

[0088] The structure of the organic electroluminescent device is: ITO / HT-1 (20nm) / green light host material (35nm): Ir(ppy)3[10%] / TPBI(10nm) / Alq3(15nm) / LiF(0.5nm) / Al(150nm). "Ir(ppy)3[10%]" refers to the doping ratio of the green light dye, that is, the volume ratio of the green light host material to Ir(ppy)3 is 90:10.

[0089] The preparation process of organic electroluminescent device is as follows:

[0090] (1) a glass plate coated with an ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment until the water was completely removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam;

[0091] (2) Place the glass substrate with the anode in a vacuum chamber and evacuate the chamber to a vacuum of 1×10 -5 ~9×10 -4 Pa, vacuum evaporating a hole transport layer HT-1 on the above anode layer film, the evaporation rate is 0.1nm / s, and the evaporation film thickness is 20nm;

[0092] (3) Vacuum evaporation of a green light host material and dye Ir(ppy)3 on the hole transport layer as the light-emitting layer of the organic electroluminescent device, with an evaporation rate of 0.1 nm / s and a total evaporation film thickness of 35 nm; In this embodiment, the first compound H-1 and the second compound E-1 are placed in different evaporation sources for heating, and the heating rate is controlled so that the volume ratio of the two evaporated onto the substrate is 1:1, as the green light host material.

[0093] (4) vacuum evaporating the electron transport layer TPBI and Alq3 on the light-emitting layer in sequence, with the evaporation rate of each being 0.1 nm / s and the evaporation film thickness being 10 nm and 15 nm respectively;

[0094] (5) 0.5 nm of LiF and 150 nm of Al were vacuum-deposited on the electron transport layer as the electron injection layer and cathode, respectively.

[0095] Device Examples 2-19

[0096] Device Examples 2-19 respectively provide an organic electroluminescent device, which differs from Device Example 1 only in that the green light main material is different. The specific selection of the green light main material is shown in Table 1. The volume ratio of the two components in the green light main body evaporated onto the substrate is 1:1, and the other preparation steps and conditions are the same as those of Device Example 1.

[0097] Device Comparison Examples 1-9

[0098] Device comparison examples 1-9 respectively provide an organic electroluminescent device, which is different from device example 1 only in that the first compound and / or the second compound in the green light host material is different. In device comparison examples 5-6, only a single compound is used as the green light host material. The specific selection of the green light host material is shown in Table 1. When there are two components in the green light host, the volume ratio of the two components evaporated onto the substrate is 1:1. The other preparation steps and conditions are the same as those in device example 1.

[0099] Performance Test:

[0100] The OLED-1000 multi-channel accelerated aging life and light color performance analysis system produced by Hangzhou Yuanfang was used to test the brightness, driving voltage, current efficiency, and life test LT90 of the prepared organic electroluminescent device. Among them, the life test LT90 refers to the current density at room temperature (25-27°C) at the initial brightness (here 1000cd / m 2 ), the time required for the brightness to decrease to 90% of the initial brightness. In the following table, voltage, efficiency, and LT90 are all relative values.

[0101] The test results are detailed in Table 1 below.

[0102] Table 1

[0103]

[0104]

[0105] Where “ / ” indicates that the component does not exist.

[0106] As can be seen from the contents of Table 1, in the present invention, a composition is obtained by selecting the first compound and the second compound for use in combination, and the composition is used as the main material of the light-emitting layer. The prepared organic electroluminescent device has a lower driving voltage, a higher current efficiency and a longer life.

[0107] By comparing the relevant data of the device embodiment and the device comparison example, it can be seen that in the present invention, a composition with a specific composition is obtained by the mutual coordination of a first compound with a specific structure and a second compound with a specific structure. The composition is used as the main material of the light-emitting layer, which can further improve the comprehensive performance of the organic electroluminescent device, so that it has a lower driving voltage, higher current efficiency and longer life.

[0108] Device Example 20

[0109] This device embodiment provides an organic electroluminescent device, and the composition provided by the present invention is selected as the green light host material in the organic electroluminescent device. The specific composition of the composition is shown in Table 2 below.

[0110] The structure of the organic electroluminescent device is: ITO / HT-1 (20nm) / electron blocking layer (5nm) / green light host material (35nm): Ir(ppy)3[10%] / TPBI(10nm) / Alq3(15nm) / LiF(0.5nm) / Al(150nm). "Ir(ppy)3[10%]" refers to the doping ratio of the green light dye, that is, the volume ratio of the green light host material to Ir(ppy)3 is 90:10.

[0111] The preparation process of organic electroluminescent device is as follows:

[0112] (1) a glass plate coated with an ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment until the water was completely removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam;

[0113] (2) Place the glass substrate with the anode in a vacuum chamber and evacuate the chamber to a vacuum of 1×10 -5 ~9×10 -4 Pa, vacuum evaporating a hole transport layer HT-1 on the above anode layer film, the evaporation rate is 0.1nm / s, and the evaporation film thickness is 20nm;

[0114] (3) Vacuum evaporation of EB-1 as an electron blocking layer on the hole transport layer at a rate of 0.1 nm / s and a film thickness of 5 nm;

[0115] (4) Vacuum evaporating a green light host material and dye Ir(ppy)3 on the electron blocking layer as the light-emitting layer of the organic electroluminescent device, the evaporation rate is 0.1 nm / s, and the total evaporation film thickness is 35 nm; In this embodiment, the first compound H-1 and the second compound E-1 are placed in different evaporation sources for heating, and the heating rate is controlled so that the volume ratio of the two evaporated onto the substrate is 1:1, as the green light host material.

[0116] (5) vacuum evaporating electron transport layers TPBI and Alq3 on the light-emitting layer in sequence, with the evaporation rate of each being 0.1 nm / s and the evaporation film thickness being 10 nm and 15 nm respectively;

[0117] (6) 0.5 nm of LiF and 150 nm of Al were vacuum-deposited on the electron transport layer as the electron injection layer and cathode, respectively.

[0118] Device Examples 21-23

[0119] Device Examples 21-23 provide an organic electroluminescent device, which differs from Device Example 20 only in that the electron blocking layer material and / or the main material of the light-emitting layer is different (see Table 2 below for details), and the other preparation steps and conditions are the same as those of Device Example 20.

[0120] Performance Test:

[0121] The OLED-1000 multi-channel accelerated aging life and light color performance analysis system produced by Hangzhou Yuanfang was used to test the brightness, driving voltage, current efficiency, and life test LT90 of the prepared organic electroluminescent device. Among them, the life test LT90 refers to the current density at room temperature (25-27°C) at the initial brightness (here 1000cd / m 2 ), the time required for the brightness to decrease to 90% of the initial brightness. In the following table, voltage, efficiency, and LT90 are all relative values.

[0122] The test results are detailed in Table 2 below.

[0123] Table 2

[0124]

[0125] It can be seen from the contents of Table 2 that in the present invention, a composition with a specific composition is obtained by the mutual coordination of a first compound with a specific structure and a second compound with a specific structure, and an electron blocking layer material with a specific structure is used in combination, which can further improve the comprehensive performance of the organic electroluminescent device, so that it has a lower driving voltage, a higher current efficiency and a longer life.

[0126] The applicant declares that the present invention illustrates the detailed process flow of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed process flow, that is, it does not mean that the present invention must rely on the above-mentioned detailed process flow to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A composition, characterized in that The composition includes at least one first compound and at least one second compound; The first compound has a structure shown in the following formula I: Among them, Ar 21 ,Ar 22 Each independently selected from any one or a combination of at least two of phenyl, diphenyl, terphenyl, quaterphenyl and naphthyl; Ar 23 Any one selected from a single bond, a phenylene group, a naphthylene group, a biphenylene group, a terphenylene group or a quaterphenylene group; The second compound has a structure shown in the following formula II: Among them, Ar 31 ,Ar 32 ,Ar 33 Each is independently selected from any one of a single bond, a phenylene group, a biphenylene group, a terphenylene group, a quaterphenylene group or a naphthylene group; X1-X6 are each independently selected from N or CR5, and at least one of X1-X6 is selected from N; R1 to R5 are each independently any one of H, phenyl, biphenyl, terphenyl, quaterphenyl, and naphthyl, or a combination of at least two thereof; The hydrogen atoms in the first compound and the second compound may each independently be replaced by a deuterium atom.

2. The composition according to claim 1, characterized in that The first compound is selected from the compound represented by formula I-1 or the compound represented by formula I-2: Among them, Ar 21 ,Ar 22 Each independently selected from any one or a combination of at least two of phenyl, diphenyl, terphenyl, quaterphenyl and naphthyl; The hydrogen atoms in the compound represented by formula I-1 or the compound represented by formula I-2 may each independently be replaced by a deuterium atom; Preferably, Ar in the first compound 21 ,Ar 22 The hydrogen atoms in the ions are each independently replaced by deuterium atoms.

3. The composition according to claim 1 or 2, characterized in that The first compound is selected from the compound represented by formula I-1-D or the compound represented by formula I-2-D: Among them, Ar 21 ,Ar 22 Each is independently selected from any one or a combination of at least two of phenyl, biphenyl, terphenyl, quaterphenyl and naphthyl.

4. The composition according to any one of claims 1 to 3, characterized in that The Ar 21 ,Ar 22 The sum of the number of benzene rings in is selected from integers ≥ 4; Preferably, the Ar 21 is phenyl, the Ar 22 Any one selected from diphenyl, terphenyl or quaterphenyl; Preferably, the Ar 21 is a diphenyl group, wherein Ar 22 Selected from diphenyl or terphenyl.

5. The composition according to any one of claims 1 to 4, characterized in that The first compound is selected from any one of the following substituted or unsubstituted compounds: The substitution means that the hydrogen atoms in the above compounds can each independently be replaced by deuterium atoms; Preferably, the first compound is selected from any one of the following substituted or unsubstituted compounds H-1 to H-28, H101 to H105, H-17o, H-17m, H-101 to H-106: The substitution means that the hydrogen atoms in the above compounds can each be independently replaced by a deuterium atom.

6. The composition according to any one of claims 1 to 5, characterized in that The Ar 33 is selected from phenylene or a single bond; Preferably, X1 to X3 are all selected from N; Preferably, X1 to X6 are all selected from N; Preferably, X1-X3 are all selected from N, X4-X6 are each independently selected from CR5, and R5 has the same protection scope as claim 1; Preferably, R1 and R2 are each independently selected from phenyl or biphenyl.

7. The composition according to any one of claims 1 to 6, characterized in that The second compound is selected from the compound represented by formula II-1: Among them, Ar 31 ,Ar 32 ,Ar 33 , X1~X6, R1~R5 have the same protection scope as claim 1.

8. The composition according to any one of claims 1 to 7, characterized in that The second compound is selected from any one of the following substituted or unsubstituted compounds: Wherein, the substitution means that the hydrogen atoms in the above compounds can be independently replaced by deuterium atoms; Preferably, the second compound is selected from any one of the following substituted or unsubstituted compounds: The substitution means that the hydrogen atoms in the above compound can be independently replaced by deuterium atoms.

9. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises an anode, a cathode and an organic thin film layer arranged between the anode and the cathode; The material of the organic thin film layer comprises the composition according to any one of claims 1 to 8; Preferably, the organic thin film layer includes a hole layer and a light-emitting layer; The host material of the light-emitting layer comprises the composition according to any one of claims 1 to 8.

10. The organic electroluminescent device according to claim 9, characterized in that: The hole layer includes an electron blocking layer, and the material of the electron blocking layer includes a compound having a structure shown in the following formula A: Among them, R 601 Any one selected from tert-butyl substituted phenyl, methylcyclopentyl substituted phenyl, methylcyclohexyl substituted phenyl, methylcyclopentyl, methylcyclohexyl or tert-butyl; Ring A and Ring B are each independently selected from a benzene ring or a naphthalene ring; Ar 601 is selected from phenyl, naphthyl, phenylene or naphthylene; m, n, and p are each independently selected from 0 or 1; The hydrogen atoms in the compound of formula A may each independently be replaced by a deuterium atom; Preferably, the compound of formula A is selected from any one of the following substituted or unsubstituted compounds: The substitution means that the hydrogen atoms in the above compounds can each be independently replaced by a deuterium atom.

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