Compounds and organic electroluminescent devices and display devices

Abstract

The present application relates to the field of electroluminescence, and discloses a compound, an organic electroluminescent device, and a display device. The structural formula of the compound is shown in formula (I): The organic electroluminescent device using the material of the compound of the present application has a lower driving voltage and a higher current efficiency.

Description

Technical Field

[0001] The present application relates to the field of electroluminescence, and in particular to a compound and an organic electroluminescent device and a display device. Background Art

[0002] Currently, organic electroluminescent (OLED) display technology has been applied in smart phones, tablet computers and other fields, and will be further expanded to large-size application fields such as televisions. In the past 30 years of development, people have developed various OLED materials with excellent performance, and through different designs of device structures and optimization of device performance such as life and efficiency, the commercialization process of OLED has been accelerated, making OLED widely used in the display and lighting fields.

[0003] However, the huge gap between the external quantum efficiency and internal quantum efficiency of OLEDs has greatly restricted the development of OLEDs. One of the most important factors is that the efficiency of the device has not yet reached the ideal level. This is due to the mode loss of the substrate, the loss of the surface plasmon and the waveguide effect, which confines most of the light inside the light-emitting device, thereby reducing the luminous efficiency of the device. Improving the luminous efficiency of the device and using light extraction materials is one of the effective methods. The light extraction layer (Capping Layer, CPL) can effectively improve the light extraction efficiency of the device by reducing the surface plasma effect of the metal electrode and adjusting the light extraction direction and light extraction efficiency, thereby improving the luminous efficiency of the device. At present, the types of light extraction materials are relatively single, and the effects are not ideal. Developing more effective light extraction materials is one of the more severe challenges facing OLED workers.

[0004] In addition, the selection of light-emitting layer and other organic functional layer materials also has a significant impact on the current efficiency and driving voltage of the device, and functional layer materials with higher performance are still being explored.

[0005] Therefore, in order to meet people's higher requirements for OLED devices, the field is in urgent need of developing more types of OLED materials with higher performance. Summary of the invention

[0006] The present application discloses a compound, an organic electroluminescent device and a display device. The organic electroluminescent device using the material of the compound of the present application has a lower driving voltage and a higher current efficiency.

[0007] In order to achieve the above objectives, this application provides the following technical solutions:

[0008] A compound, the structural formula of the compound is as shown in formula (I),

[0009]

[0010] Wherein, m, n, p are selected from 0 or 1;

[0011] A, B, and Q are each independently selected from an aromatic group containing 6 to 40 carbon atoms, wherein the hydrogen in the aromatic group containing 6 to 40 carbon atoms may be replaced by R;

[0012] Ar1 is selected from formula (II), wherein R1 to R 10 At least one is absent, and the corresponding carbon atom is connected to the N atom or A in formula (I); X is selected from oxygen or sulfur;

[0013] Ar2 is selected from an aromatic group containing 6 to 40 carbon atoms or formula (II), wherein the hydrogen in the aromatic group containing 6 to 40 carbon atoms may be replaced by R;

[0014] Ar3 is selected from formula (III), * represents the position where Ar3 is connected to the Q or N atom in formula (I), and the hydrogen in Ar3 may be replaced by one or more R;

[0015] R and R1~R 10 Each is independently selected from hydrogen, deuterium, F, CN, an alkyl group containing 1 to 20 carbon atoms, an alkoxy group containing 1 to 20 carbon atoms or an aromatic group containing 6 to 40 carbon atoms.

[0016] Further, A, B, and Q are selected from benzene, biphenyl, naphthalene, anthracene, phenanthrene, fluoranthene, triphenylene, fluorene, spirofluorene, pyrene, benzanthracene, benzofluorene, naphthoanthracene, naphthofluorene, dibenzanthracene, dibenzofluorene, hydrogenated benzanthracene, indenofluorene, and benzindenofluorene.

[0017] Furthermore, the aromatic group of 6 to 40 carbon atoms is selected from benzene, biphenyl, naphthalene, anthracene, phenanthrene, fluoranthene, triphenylene, fluorene, spirofluorene, pyrene, benzanthracene, benzofluorene, naphthoanthracene, naphthofluorene, dibenzanthracene, dibenzofluorene, hydrogenated benzanthracene, indenofluorene, and benzindenofluorene.

[0018] Furthermore, the structure of the compound is one of the following structures:

[0019]

[0020] Furthermore, the structure of the compound is one of the following structures:

[0021]

[0022] Furthermore, R1 and R 10 Each is independently selected from one of F, CN, methoxy, phenyl or biphenyl.

[0023] Furthermore, the compound is one of the following structures:

[0024]

[0025]

[0026]

[0027]

[0028]

[0029] An organic electroluminescent device comprises the compound described in the present application.

[0030] A display device includes the organic electroluminescent device provided in the present application.

[0031] The technical solution of this application produces the following beneficial effects:

[0032] The compound represented by formula (I) of the present application is a new compound and can be used in organic electroluminescent devices as HTL, EBL, and Host materials. In addition, the OLED device prepared using the compound material represented by formula (I) of the present application has low driving voltage and high luminous efficiency. DETAILED DESCRIPTION

[0033] The following will be combined with the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0034] It should be noted that: in this application, if there is no special description, all the embodiments and preferred implementation methods mentioned herein can be combined with each other to form a new technical solution. In this application, if there is no special description, all the technical features and preferred features mentioned herein can be combined with each other to form a new technical solution. In this application, if there is no special description, percentage (%) or part refers to the weight percentage or weight part relative to the composition. In this application, if there is no special description, the components or their preferred components involved can be combined with each other to form a new technical solution. In this application, unless otherwise specified, the numerical range "a-b" represents an abbreviation of any real number combination between a and b, where a and b are both real numbers. For example, the numerical range "6-22" means that all real numbers between "6-22" have been listed in this article, and "6-22" is just an abbreviation of these numerical combinations. The "range" disclosed in this application can be one or more lower limits and one or more upper limits in the form of lower limits and upper limits. In this application, unless otherwise specified, each reaction or operation step can be carried out sequentially or not in sequence. Preferably, the reaction method in this article is carried out sequentially.

[0035] Unless otherwise specified, the professional and scientific terms used herein are the same as those familiar to those skilled in the art. In addition, any method or material similar or equivalent to the described content may also be applied to the present application.

[0036] The present application provides a compound, whose structural formula is shown in formula (I),

[0037]

[0038] Wherein, m, n, p are selected from 0 or 1;

[0039] A, B, and Q are each independently selected from an aromatic group containing 6 to 40 carbon atoms, wherein the hydrogen in the aromatic group containing 6 to 40 carbon atoms may be replaced by R;

[0040] Ar1 is selected from formula (II), wherein R1 to R 10 At least one is absent, and the corresponding carbon atom is connected to the N atom or A in formula (I); X is selected from oxygen or sulfur;

[0041] Ar2 is selected from an aromatic group containing 6 to 40 carbon atoms or formula (II), wherein the hydrogen in the aromatic group containing 6 to 40 carbon atoms may be replaced by R;

[0042] Ar3 is selected from formula (III), * represents the position where Ar3 is connected to the Q or N atom in formula (I), and the hydrogen in Ar3 may be replaced by one or more R;

[0043] R and R1~R10 Each is independently selected from hydrogen, deuterium, F, CN, an alkyl group containing 1 to 20 carbon atoms, an alkoxy group containing 1 to 20 carbon atoms or an aromatic group containing 6 to 40 carbon atoms.

[0044] Specifically, as an exemplary illustration, the compounds defined in the present application may include any one of Table 1.

[0045] Table 1

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055] Among them, in each compound listed in Table 1, each fragment is connected by an Sp2 hybridized carbon atom, and any SP2 hybridized carbon atom can participate in the connection. If the fragment is composed of two or more aromatic rings, these two or more aromatic rings can also be connected arbitrarily. Examples are as follows: Compound 1-2 in Table 1 includes but is not limited to the following structure:

[0056]

[0057]

[0058] Synthesis of Compound B-1 (A-37) in Synthesis Example 1 The synthesis route is as follows:

[0059]

[0060] In a 500 ml three-necked flask, under nitrogen protection, add 250 ml of dry toluene, 4.84 g (0.01 mol) of the compound shown in M-1, 2.97 g (0.01 mol) of 3-bromobenzo[kl]xanthene, 0.0575 g (0.0001 mol) of Pd(dba)2 (bis(dibenzylideneacetonepalladium), 0.4 g (0.0002 mol) of a toluene solution containing 10% tri-tert-butylphosphine, and 1.44 g (0.015 mol) of sodium tert-butoxide. Heat to reflux for 6 hours, cool, add water to separate, wash the organic layer with water until neutral, dry with magnesium sulfate, filter to remove magnesium sulfate, concentrate to dryness, separate by silica gel column chromatography, and elute with petroleum ether:ethyl acetate = 10:0.5 (volume ratio) to obtain 5.8 g of the compound shown in formula B-1.

[0061] The compound represented by formula B-1 was subjected to mass spectrometry detection, and the m / z of the molecule was determined to be 699.

[0062] The compound represented by formula B-1 was subjected to NMR detection, and the data analysis is as follows: 1H-NMR (Bruker Company, Switzerland, AvanceⅡ400MHz NMR spectrometer, CDCl3), δ8.06 (m, 1H), δ7.96 (m, 1H), δ7.93~7.84 (m, 4H), δ7.73 (m, 2H), δ7.69 (m, 2H), δ7.62 (d, 1H), δ7.60~7.44 (m, 6H), δ7.43~7.20 (m, 13H), δ7.19~7.13 (m, 2H), δ6.39 (m, 1H).

[0063] Synthesis Example 2 Synthesis of Compound B-2

[0064] The synthetic route is as follows:

[0065]

[0066] The synthesis method refers to the synthesis of compound B-1 in Example 1, where the compound represented by M-1 is replaced by the compound represented by M-2, and the 3-bromobenzo[kl]xanthene is replaced by 3-(4-bromophenyl)benzo[kl]xanthene to obtain compound B-2.

[0067] The compound shown in B-2 was subjected to mass spectrometry detection, and the m / z of the molecule was determined to be: 815.

[0068] Synthesis Example 3 Synthesis of Compound B-3

[0069] The synthetic route is as follows:

[0070]

[0071] The synthesis method refers to the synthesis of compound B-1 in Example 1, and the compound represented by M-1 is replaced by the compound represented by M-21 to obtain compound B-3.

[0072] The compound shown in B-3 was subjected to mass spectrometry detection, and the m / z of the molecule was determined to be 775.

[0073] Synthesis Example 4 Synthesis of Compound B-4

[0074]

[0075] The synthesis method refers to the synthesis of compound B-1 in Example 1, where the compound represented by M-1 is replaced by the compound represented by M-21, and the 3-bromobenzo[kl]oxanthene is replaced by 3-(4-bromophenyl)benzo[kl]oxanthene to obtain compound B-4.

[0076] The compound shown in B-4 was subjected to mass spectrometry detection, and the m / z of the molecule was determined to be: 851.

[0077] Synthesis Example 5 Synthesis of Compound A-11

[0078] (1) Synthesis of intermediate M-10

[0079]

[0080] In a 250 ml three-necked flask, under nitrogen protection, add 30 ml of DMF, 2.97 g (0.01 mol) of 8-bromobenzo[kl]xanthene, 0.5 g of cuprous iodide, and 1.16 g (0.02 mol) of KF, heat to reflux for 24 hours, cool to room temperature, add water and dichloromethane for separation, wash the organic layer with water until neutral, dry with magnesium sulfate, filter out the magnesium sulfate, concentrate the organic layer to dryness, separate by silica gel column chromatography, and elute with petroleum ether to obtain 0.9 g of the compound shown in M-10.

[0081] The compound shown by M-10 was subjected to mass spectrometry detection, and the m / z of the molecule was determined to be: 236.

[0082] (2) Synthesis of intermediate M-11

[0083]

[0084] To a 250 ml three-necked flask, add 80 ml of DMF and 2.36 g (0.01 mol) of 8-fluorobenzo[kl]xanthene shown in M-10. Control the temperature at 20-25°C. Add 1.78 g (0.01 mol) of N-bromosuccinimide (NBS) in batches while stirring. Then control the temperature at 20-25°C to react for 6 hours. Add water and dichloromethane for separation. Wash the organic layer with water, separate it by silica gel column chromatography, and elute with petroleum ether to obtain 1.6 g of the compound shown in M-11.

[0085] The compound represented by formula M-11 was detected by mass spectrometry. The two largest peaks were 314 and 316. The molecular formula of the product was determined to be: C 16 H8BrFO.

[0086] The compound represented by formula M-11 was subjected to NMR detection, and the data analysis is as follows: 1H-NMR (Bruker Company, Switzerland, AvanceⅡ400MHz NMR spectrometer, CDCl3), δ8.49 (m, 1H), δ7.71 (m, 2H), δ7.68 (m, 1H), δ7.65 (m, 1H), δ7.46 (d, 1H), δ7.24 (m, 1H), δ7.20 (m, 1H).

[0087] (3) Synthesis of Compound A-11

[0088]

[0089] The synthesis method refers to the synthesis of compound B-1 in Example 1, replacing the compound represented by M-1 with the compound represented by M-2, and replacing 3-bromobenzo[kl]oxanthene with the compound represented by M-11 to obtain compound A-11.

[0090] The compound A-11 was subjected to mass spectrometry detection, and the m / z of the molecule was determined to be 757.

[0091] Synthesis Example 6 Synthesis of Compound A-25

[0092] (1) Synthesis of intermediate M-3

[0093]

[0094] In a 250 ml three-necked flask, add 50 ml DMF and 2.97 g (0.01 mol) 8-bromobenzo[kl]xanthene, control the temperature at 20-25°C, add 2.25 g (0.01 mol) N-iodosuccinimide (NIS) in batches under stirring, then control the temperature at 20-25°C to react for 2 hours, then raise the temperature to 40-45°C to react for 1 hour, then raise the temperature to 60°C to react for 1 hour, cool down, add water and dichloromethane for separation, wash the organic layer with water, separate it by silica gel column chromatography, and elute with petroleum ether to obtain 1.8 g of the compound shown in M-3.

[0095] The compound represented by formula M-3 was detected by mass spectrometry. The two largest peaks were 422 and 424. The molecular formula of the product was determined to be: C 16 H8BrIO.

[0096] The compound represented by formula M-3 was subjected to NMR detection, and the data analysis was as follows: 1H-NMR (Bruker Company, Switzerland, AvanceⅡ400MHz NMR spectrometer, CDCl3), δ8.51 (m, 1H), δ7.88 (m, 1H), δ7.82 (m, 2H), δ7.68 (m, 1H), δ7.62 (d, 1H), δ7.44 (d, 1H), δ7.10 (m, 1H).

[0097] (2) Synthesis of intermediate M-4

[0098]

[0099] In a 250 ml three-necked flask, under nitrogen protection, add 60 ml toluene, 40 ml ethanol, 20 ml water, and then add 4.23 g (0.01 mol) of the compound shown in M-3, 1.22 g (0.01 mol) of phenylboric acid, 2.12 g (0.02 mol) of sodium carbonate, and 0.115 g (0.0001 mol) of tetrakistriphenylphosphine palladium. Slowly raise the temperature to 60°C and react for 8 hours. Cool down and add water to separate. After washing the organic layer with water, add magnesium sulfate and a small amount of 200-300 mesh silica gel to dry. After filtering to remove magnesium sulfate and silica gel, remove the solvent under reduced pressure. The obtained solid is recrystallized twice with a mixed solvent of chlorobenzene and methanol to obtain 3.1 g of the compound shown in M-4.

[0100] The compound M-4 was detected by mass spectrometry. The two largest peaks were 372 and 374. The molecular formula of the product was determined to be: C 22 H 13 BrO.

[0101] (3) Synthesis of Compound A-25

[0102]

[0103] The synthesis method refers to the synthesis of compound B-1 in Example 1, and the 3-bromobenzo[kl]xanthene therein is replaced with the compound shown in M-4 to obtain compound A-25.

[0104] The compound A-25 was subjected to mass spectrometry detection, and the m / z of the molecule was determined to be 775.

[0105] Synthesis Example 7 Synthesis of Compound A-28

[0106] (1) Synthesis of intermediate M-8

[0107]

[0108] In a 250 ml three-necked flask, under nitrogen protection, add 50 ml DMF, 4.23 g (0.01 mol) of the compound represented by formula M-3, 0.1 g of cuprous iodide, and 1.16 g (0.02 mol) of KF, heat to reflux for 24 hours, cool to room temperature, add water and dichloromethane for separation, wash the organic layer with water until neutral, dry with magnesium sulfate, filter out the magnesium sulfate, concentrate the organic layer to dryness, separate by silica gel column chromatography, and elute with petroleum ether to obtain 1.6 g of the compound represented by M-8.

[0109] The compound M-8 was detected by mass spectrometry. The two largest peaks were 314 and 316. The molecular formula of the product was determined to be: C 16 H8BrFO.

[0110] (2) Synthesis of Compound A-28

[0111]

[0112] The synthesis method refers to the synthesis of compound B-1 in Example 1, and the 3-bromobenzo[kl]xanthene therein is replaced with the compound shown in M-8 to obtain compound A-28.

[0113] The compound A-28 was subjected to mass spectrometry detection, and the m / z of the molecule was determined to be 717.

[0114] Synthesis Example 8 Synthesis of Compound A-29

[0115] (1) Synthesis of intermediate M-9

[0116]

[0117] In a 250 ml three-necked flask, under nitrogen protection, add 50 ml DMF, 4.23 g (0.01 mol) of the compound represented by formula M-3, 0.1 g of cuprous iodide, and 1.79 g (0.02 mol) of CuCN, heat to reflux for 24 hours, cool to room temperature, add water and dichloromethane for separation, wash the organic layer with water until neutral, dry with magnesium sulfate, filter out the magnesium sulfate, concentrate the organic layer to dryness, separate by silica gel column chromatography, and elute with petroleum ether to obtain 1.9 g of the compound represented by M-9.

[0118] The compound M-9 was detected by mass spectrometry. The two largest peaks were 321 and 323. The molecular formula of the product was determined to be: C 17 H8BrNO.

[0119] (2) Synthesis of Compound A-29

[0120]

[0121] The synthesis method refers to the synthesis of compound B-1 in Example 1, except that 3-bromobenzo[kl]xanthene is replaced by the compound shown in M-9 to obtain compound A-29.

[0122] The compound A-29 was subjected to mass spectrometry detection, and the m / z of the molecule was determined to be 724.

[0123] Synthesis Example 9 Synthesis of Compound BS-1

[0124]

[0125] Referring to the synthesis of compound B-1 in Example 1, 3-bromobenzo[kl]xanthene was replaced with 3-bromobenzo[kl]thioanthene to obtain compound BS-1.

[0126] The compound represented by BS-1 was subjected to mass spectrometry detection, and the m / z of the molecule was determined to be 715.

[0127] Device Example:

[0128] Synthesis of HT-4:

[0129]

[0130] Referring to the synthesis of compound 1 in Example 1, except that 3-bromobenzo[kl]xanthene was replaced with 5-naphtho[2,1-b]benzofuran, compound HT-4 was obtained.

[0131] The compound represented by HT-4 was subjected to mass spectrometry detection, and the m / z of the molecule was determined to be 699.

[0132] It should be noted that the preparation methods of the above compounds are only illustrative, and other compounds within the scope of the present application can be prepared by referring to the preparation methods of the above-mentioned example compounds.

[0133] The specific structures of several materials used in the device embodiments of this application are as follows:

[0134]

[0135]

[0136] Device Example 1

[0137] The device of this embodiment uses the compound of the present application as the hole transport material in the organic electroluminescent device, and the comparative embodiment uses HT-1 to H-4 as the hole transport material in the organic electroluminescent device.

[0138] The structure of the organic electroluminescent device is: ITO / HIL02 (100nm) / hole transport material (40nm) / EM1 (35nm) / TPBI (30nm) / LiF (0.5nm) / Al (150nm).

[0139] The preparation process of organic electroluminescent device is as follows:

[0140] The glass substrate coated with an ITO transparent conductive layer (as an anode) is ultrasonically treated in a cleaning agent, then rinsed in deionized water, ultrasonically degreased in a mixed solvent of acetone and ethanol, baked in a clean environment until the water is completely removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam to improve the properties of the surface and enhance the binding ability with the hole injection layer;

[0141] The glass substrate was placed in a vacuum chamber and evacuated to 1×10 -5 ~9×10 -3 Pa, vacuum evaporate HIL02 on the anode as a hole injection layer, the evaporation rate is 0.1nm / s, and the evaporation film thickness is 100nm;

[0142] The compound of the present application and the comparative material are vacuum-deposited on the hole injection layer as a hole transport layer, respectively, with a deposition rate of 0.1 nm / s and a deposition film thickness of 40 nm;

[0143] EM1 was vacuum-deposited on the hole transport layer as the organic light-emitting layer of the device, with a deposition rate of 0.1 nm / s and a total deposition film thickness of 35 nm;

[0144] Vacuum evaporation of TPBI on the organic light-emitting layer as the electron transport layer of the organic electroluminescent device; the evaporation rate is 0.1nm / s, and the total evaporation film thickness is 30nm;

[0145] 0.5 nm of LiF and 150 nm of Al were vacuum-deposited on the electron transport layer to serve as an electron injection layer and a cathode.

[0146] The brightness, driving voltage and current efficiency of the prepared organic electroluminescent device were measured.

[0147] The performance of the organic electroluminescent device is shown in Table 2. The test was conducted using the OLED-1000 multi-channel accelerated aging life and light color performance analysis system produced by Hangzhou Yuanfang.

[0148] Table 2

[0149] Hole transport materials <![CDATA[Required brightness cd / m 2 > Drive voltage V Current efficiency cd / A HT-1 1000 6.02 1.26 HT-2 1000 6.11 1.33 HT-3 1000 6.13 1.31 HT-4 1000 6.66 1.29 B-1 1000 5.62 1.61 BS-1 1000 5.55 1.65 B-2 1000 5.58 1.62 B-3 1000 5.76 1.77 B-4 1000 5.88 1.68 A-11 1000 4.68 1.66 A-25 1000 4.66 1.72 A-28 1000 4.57 1.7 A-29 1000 4.41 1.82 A-32 1000 4.39 1.76 A-34 1000 4.41 1.71

[0150] It can be seen from the data in Table 2 that, compared with compounds HT-1 to HT-4, the compounds provided in the present application are used as hole transport materials for organic electroluminescent devices, which can improve the current efficiency of the device and reduce the driving voltage. Specifically, compared with the comparative example, the driving voltage of the organic electroluminescent device using the compound of the present application as the hole transport material is reduced and the efficiency is increased. The current efficiency of the organic electroluminescent device prepared using the compounds of the present application can reach more than 1.6cd / A, and the driving voltage can be reduced to less than 6V. In particular, the devices corresponding to compounds A-11 to A-34 can reduce the driving voltage to less than 4.7V.

[0151] Device Example 2

[0152] The device of this embodiment uses the compound of the present application as the red light host material in the organic electroluminescent device, and the comparative embodiment uses HT-1 to HT-4 as the red light host material in the organic electroluminescent device.

[0153] The structure of the organic electroluminescent device is: ITO / NPB (20nm) / red light host material (35nm): Ir(piq)3[10%] / TPBI (10nm) / Alq3(15nm) / LiF(0.5nm) / Al(150nm). "Ir(piq)3[10%]" refers to the doping ratio of the red light dye, that is, the weight ratio of the red light host material to Ir(piq)3 is 100:10.

[0154] The organic electroluminescent device was prepared as follows: 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 to completely remove water, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam;

[0155] Place the glass substrate with the anode in a vacuum chamber and evacuate to 1×10 -5 ~9×10 -3 Pa, vacuum evaporating a hole transport layer NPB on the above anode layer film, the evaporation rate is 0.1nm / s, and the evaporation film thickness is 20nm;

[0156] Vacuum evaporate the red light host material and dye Ir(piq)3 on the hole transport layer as the light-emitting layer of the organic electroluminescent device, the evaporation rate is 0.1nm / s, and the total evaporation film thickness is 35nm;

[0157] The electron transport layer TPBI and Alq3 were vacuum-deposited on the light-emitting layer in sequence, with the evaporation rate of both being 0.1 nm / s and the thickness of the evaporated films being 10 nm and 15 nm respectively;

[0158] 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.

[0159] All organic electroluminescent devices are prepared by the above method, and the only difference is the selection of red light host materials, as shown in Table 3 below.

[0160] Performance Testing:

[0161] The brightness, driving voltage and current efficiency of the prepared organic electroluminescent device were measured using the OLED-1000 multi-channel accelerated aging life and light color performance analysis system produced by Hangzhou Yuanfang. The test results are shown in the following table.

[0162] Table 3

[0163] Red light main material <![CDATA[Required brightness cd / m 2 > Drive voltage V Current efficiency cd / A HT-1 1000 5.11 40.22 HT-2 1000 5.30 38.19 HT-3 1000 5.19 41.23 HT-4 1000 5.18 42.33 B-2 1000 4.66 50.76 B-3 1000 4.78 51.88 B-4 1000 4.77 52.33 B-5 1000 4.73 52.65 A-25 1000 3.96 51.56 A-28 1000 4.10 55.41 A-29 1000 4.06 52.22 A-36 1000 4.15 53.18

[0164] It can be seen from the data in Table 3 that, compared with compounds HT-1 to HT-4, the compounds provided in the present application as red light main materials of organic electroluminescent devices can improve the current efficiency of the device and reduce the driving voltage. Specifically, compared with the comparative example, the driving voltage of the organic electroluminescent device using the compounds of the present application as the red light main material is reduced and the efficiency is increased. The current efficiency of the organic electroluminescent device prepared using the compounds of the present application can reach more than 50cd / A, and the driving voltage can be reduced to below 4.8V. In particular, the devices corresponding to compounds A-25 to A-36 can reduce the driving voltage to below 4.2V.

[0165] Obviously, those skilled in the art can make various changes and modifications to the embodiments of the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises any one of the following compounds:

2. A display device, characterized in that: The organic electroluminescent device as claimed in claim 1 is included.

Images