Organic compound containing phenanthroline and phosphine substituent and organic electroluminescent device containing organic compound

Abstract

The invention discloses an organic compound containing phenanthroline and phosphine substituent and an organic electroluminescent device containing the same. The organic compound is selected from a structural general formula as shown in a formula I in the specification. By introducing an aryl substituted phenanthroline structure into the structure, a tetradentate ligand coordinated with rare earth metal can be formed, formation of a more stable 8-coordination complex is facilitated, the stability of an n-CGL layer is improved, and by using a phosphine oxide structure in the structure, the limiting capability on the rare earth metal is improved, and the drift voltage is improved. In addition, direct connection between phosphine atoms and large conjugated substituents such as naphthalene is avoided, or larger polycyclic aromatic hydrocarbons such as anthracene, anthracene and pyrene in molecules are avoided, so that the coordination capability of a phosphine-oxygen structure to metals can be enhanced. The invention also finds that when the compound of the formula I structure is used as an n-CGL material and the compound of the formula II structure is used as an electron transport layer material in a combined manner, the injection barrier between interfaces can be reduced, and the driving voltage of the organic electroluminescent device is further reduced. # imgabs0 #

Description

Technical Field

[0001] The invention belongs to the technical field of OLED, and specifically comprises an organic compound containing phenanthroline and a phosphine substituent and an organic electroluminescent device comprising the same. Background Art

[0002] As market demand continues to increase, stacked devices need to further reduce the driving voltage to reduce the power consumption of the overall panel. In current OLED devices, n-CGL needs to use metal dopants to reduce the injection barrier of electrons after charge separation. During the operation of the device, under the action of the electric field, the metal will migrate with the electric field. This will cause the driving voltage of the device to gradually increase as the working time increases. At the same time, due to the instability of the film layer, the device life will also decrease. To solve this problem, the n-CGL material itself needs to have a certain coordination and binding ability for metals.

[0003] Lanthanide ions are generally trivalent. Compared with transition metals, rare earth metals have more valence electrons and larger ground state spin values. At the same time, the larger ionic radius also determines the higher coordination number and diverse coordination mode of rare earth ion complexes. Under the condition that the ligand can allow, most rare earth ions form complexes with a coordination number of 8 or more. The 8-coordinated complexes have the best stability among rare earth complexes. There are only 7 atoms that can directly coordinate with rare earth ions, which are O, C, N, halogen, S, H and P in descending order according to the number of complexes. In addition, the coordination ability of oxygen atoms is stronger than that of nitrogen atoms, and they can form more stable complexes with rare earth metals. For rare earth ions, water molecules are also a ligand with strong coordination ability. The introduction of phosphine oxide can avoid device defects caused by the coordination of water molecules. In addition, we found that when phosphine atoms are directly connected to large conjugated substituents such as naphthalene, or when larger condensed aromatic hydrocarbons such as anthracene, anthracene, and pyrene exist in the molecule, these structures will weaken the coordination ability of phosphine oxygen structures for metals due to the large electron cloud density. Summary of the invention

[0004] In view of the above problems existing in the prior art, the present invention provides an organic compound containing phenanthroline and a phosphine substituent and an organic electroluminescent device containing the same.

[0005] To achieve the above objectives, the technical solutions adopted by the present invention include:

[0006] The first aspect of the present invention provides an organic compound containing phenanthroline and a phosphine substituent, wherein the organic compound is selected from the general structural formula shown in the following formula I:

[0007]

[0008] Wherein, the R1 is selected from substituted or unsubstituted phenyl or naphthalene substituted or unsubstituted group; the substituent of R1 is selected from C1-C10 alkyl;

[0009] The R2 and R3 are each independently selected from any one of hydrogen, methyl and phenyl;

[0010] The L1 is selected from any one of substituted or unsubstituted phenyl and substituted or unsubstituted naphthyl; the substituent in L1 is selected from any one of C1-C10 alkyl, C3-C10 cycloalkyl, phenyl and naphthyl or any combination thereof.

[0011] Furthermore, the organic compound is selected from one of the following structural formulas:

[0012]

[0013]

[0014] Further, the L1 is selected from naphthalene.

[0015] Furthermore, the organic compound is selected from one of the following structural formulas:

[0016]

[0017]

[0018] Further, the organic compound is selected from one of the structures shown below:

[0019]

[0020]

[0021] The second aspect of the present invention provides an organic electroluminescent device, which includes an anode, a first hole transport region, a first light-emitting layer, a first electron transport region, a charge generation region, a second hole transport region, a second light-emitting layer, a second electron transport region, a cathode, and a covering layer, which are sequentially arranged on a substrate; wherein the charge generation region includes one or more organic compounds as described above.

[0022] Furthermore, the charge generation region includes an N-type charge generation layer and a P-type charge generation layer, the N-type charge generation layer is located between the P-type charge generation layer and the first electron transport region, wherein the N-type charge generation layer includes one or more organic compounds as described above.

[0023] Furthermore, the first electron transport region and / or the second electron transport region further comprises an organic compound represented by general formula II:

[0024]

[0025] Wherein, Ar1 and Ar2 are the same or different, and each independently represents one of phenyl and naphthyl;

[0026] The ring A is selected from a substituted or unsubstituted phenyl, naphthyl, anthracenyl group;

[0027] The substituents in the ring A are selected from any one or more of C1-C10 alkyl, C3-C10 cycloalkyl, phenyl, and naphthyl; the L2 is selected from any one of substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, and substituted or unsubstituted naphthyl; the substituents in L2 are selected from any one or more of C1-C10 alkyl, C3-C10 cycloalkyl, phenyl, and naphthyl. Studies have found that when the compound of formula I and the compound of formula II are used in combination, the driving voltage of the device can be further reduced.

[0028] Further, the ring A is selected from one of phenyl, naphthyl and anthracenyl;

[0029] The substituent in L2 is selected from phenyl.

[0030] Furthermore, the first electron transport region and / or the second electron transport region further comprises one of the following structures:

[0031]

[0032]

[0033]

[0034] A third aspect of the present invention provides a display or lighting device, comprising the organic electroluminescent device as described above.

[0035] Beneficial effects of the present invention:

[0036] The invention provides an organic compound containing phenanthroline and a phosphine substituent. The compound limits the R1 group of the phenanthroline structure to a phenyl group or a naphthyl group, so that the phenanthroline fragment can coordinate with a rare earth metal to form a tetradentate ligand, which is conducive to forming a more stable 8-coordinated complex, can enhance the coordination and binding ability to the metal, and further increase the stability of the n-CGL film layer; the phosphine oxide fragment in the compound can improve the confinement ability to the rare earth metal and improve the drift voltage; the compound limits L1 to a substituted or unsubstituted phenyl group or a substituted or unsubstituted naphthyl group, so that the presence of large condensed ring aromatic hydrocarbons such as anthracene, anthracene and pyrene in the molecule can be avoided, and the coordination ability of the phosphine oxide structure to the metal is enhanced.

[0037] The present invention also finds that when the compound of formula I is used as the n-CGL material and the compound of formula II is used in combination as the electron transport layer material, the injection barrier between interfaces can be reduced, and the driving voltage of the organic electroluminescent device can be further reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic structural diagram of the organic electroluminescent device of the present invention. DETAILED DESCRIPTION

[0039] In order to more clearly understand the content of the present invention, it will be described in detail with reference to the drawings and embodiments.

[0040] The organic compound of the present invention is suitable for use in light-emitting elements, display panels and electronic devices, and is particularly suitable for use in organic electroluminescent devices. The electronic device of the present invention is a device comprising a layer of at least one organic compound, and the device may also comprise an inorganic material or a layer formed entirely of an inorganic material. The electronic device is preferably an organic electroluminescent device (OLED). The schematic structural diagram of an exemplary organic electroluminescent device is shown in FIG. Figure 1 shown.

[0041] Experimental Section

[0042] In order to understand the content of the present invention more clearly, the luminescent characteristics of the organic compound, the preparation method of the organic compound and the device will be explained in detail in conjunction with the examples. Various chemical reactions can be applied to the synthetic method of the compound of one embodiment of the present invention. However, it should be noted that the synthetic method of the compound of one embodiment of the present invention is not limited to the synthetic method described below. Unless otherwise indicated, the subsequent synthesis is carried out in anhydrous solvent under a protective gas atmosphere. Solvents and reagents can be purchased from conventional reagent suppliers.

[0043] Intermediate synthesis

[0044]

[0045] Sub-1 (40.4 g, 100 mmol), Sub-2 (24.1 g, 100 mmol) and potassium carbonate (16.56 g, 120 mmol) were added to a mixed solution of 500 ml toluene: water = 4:1 (V / V), and then tetrakistriphenylphosphine palladium (3.5 g, 3 mmol) was introduced under nitrogen protection. The reaction system was then heated to 110°C, refluxed and maintained for 8 hours, cooled to room temperature, quenched with water and separated, the organic phase was dried over anhydrous sodium sulfate, the solvent was removed by rotation, and the crude product was separated and purified using a petroleum ether: dichloromethane = 10:1 (V / V) column to finally obtain the product Sub-3: 30.1 g, yield: 83%, MS (m / z) (M+): 362.

[0046] Sub-3 (29.0 g, 80 mmol), bipyraclostrobin (21.3 g, 84 mmol) and potassium acetate (8.2 g, 84 mmol) were added to 300 ml of 1,4-dioxane, and then tetrakistriphenylphosphine palladium (2.3 g, 2 mmol) was introduced under nitrogen protection. The reaction system was then heated to 110°C, refluxed and maintained for 8 hours, cooled to room temperature, quenched with water and separated, the organic phase was dried over anhydrous sodium sulfate, the solvent was removed by rotation, and the crude product was separated and purified using a petroleum ether: dichloromethane = 10:1 (V / V) column to finally obtain product A1: 22.5 g, yield: 62%, MS (m / z) (M+): 454.

[0047] Synthesis of compounds

[0048] Synthesis Example 1

[0049]

[0050] A1 (10.6 g, 20 mmol), B1 (6.7 g, 20 mmol) and potassium carbonate (4.1 g, 30 mmol) were added to a mixed solution of 300 ml toluene: water = 4:1 (V / V), and then tetrakistriphenylphosphine palladium (1.2 g, 1 mmol) was introduced under nitrogen protection. The reaction system was then heated to 110°C, refluxed and maintained for 8 hours, cooled to room temperature, quenched with water and separated, the organic phase was dried over anhydrous sodium sulfate, the solvent was removed by rotation, and the crude product was separated and purified using a petroleum ether: dichloromethane = 10:1 (V / V) column to finally obtain product C1: 10.1 g, yield: 77%, MS (m / z) (M+): 658.

[0051] Synthesis Example 2

[0052]

[0053] The same method as in Synthesis Example 1 was used, except that A2 (10.6 g, 20 mmol) and B2 (6.7 g, 20 mmol) replaced A1 and B1, and the final product C2 was obtained: 6.8 g (yield: 52%), MS (m / z) (M+): 658.

[0054] Synthesis Example 3

[0055]

[0056] The same method as in Synthesis Example 1 was used, except that A3 (10.6 g, 20 mmol) and B3 (6.7 g, 20 mmol) replaced A1 and B1, and the final product C3 was obtained: 10.5 g (yield: 80%), MS (m / z) (M+): 658.

[0057] Synthesis Example 4

[0058]

[0059] The same method as in Synthesis Example 1 was used, except that A4 (11.1 g, 20 mmol) and B4 (6.7 g, 20 mmol) replaced A1 and B1, and the final product C4 was obtained: 9.7 g (yield: 71%), MS (m / z) (M+): 684.

[0060] Synthesis Example 5

[0061]

[0062] The same method as in Synthesis Example 1 was used, except that A5 (9.6 g, 20 mmol) and B5 (6.7 g, 20 mmol) replaced A1 and B1, and finally product C5 was obtained: 6.6 g (yield: 54%), MS (m / z) (M+): 608.

[0063] Synthesis Example 6

[0064]

[0065] The same method as in Synthesis Example 1 was used, except that A6 (11.1 g, 20 mmol) and B6 (6.7 g, 20 mmol) replaced A1 and B1, and the final product C6 was obtained: 7.9 g (yield: 58%), MS (m / z) (M+): 684.

[0066] Synthesis Example 7

[0067]

[0068] The same method as in Synthesis Example 1 was used, except that A7 (11.1 g, 20 mmol) and B7 (7 g, 20 mmol) replaced A1 and B1, and the final product C7 was obtained: 9.6 g (yield: 68%), MS (m / z) (M+): 698.

[0069] Synthesis Example 8

[0070]

[0071] The same method as in Synthesis Example 1 was used, except that A8 (10.7 g, 20 mmol) and B8 (6.7 g, 20 mmol) replaced A1 and B1, and the final product C8 was obtained: 10 g (yield: 75%), MS (m / z) (M+): 664.

[0072] Synthesis Example 9

[0073]

[0074] The same method as in Synthesis Example 1 was used, except that A9 (10.6 g, 20 mmol) and B9 (7.8 g, 20 mmol) replaced A1 and B1, and the final product C9 was obtained: 7.9 g (yield: 56%), MS (m / z) (M+): 711.

[0075] Synthesis Example 10

[0076]

[0077] The same method as in Synthesis Example 1 was used, except that A10 (11.1 g, 20 mmol) and B10 (7.8 g, 20 mmol) replaced A1 and B1, and the final product C10 was obtained: 11.2 g (yield: 76%), MS (m / z) (M+): 737.

[0078] Synthesis Example 11

[0079]

[0080] The same method as in Synthesis Example 1 was used, except that A11 (11.1 g, 20 mmol) and B11 (7.8 g, 20 mmol) replaced A1 and B1, and the final product C11 was obtained: 9.8 g (yield: 67%), MS (m / z) (M+): 737.

[0081] Synthesis Example 12

[0082]

[0083] The same method as in Synthesis Example 1 was used, except that A12 (11.1 g, 20 mmol) and B12 (7.8 g, 20 mmol) replaced A1 and B1, and the final product C12 was obtained: 8.7 g (yield: 59%), MS (m / z) (M+): 737.

[0084] Synthesis Example 13

[0085]

[0086] The same method as in Synthesis Example 1 was used, except that A13 (10.6 g, 20 mmol) and B13 (7.8 g, 20 mmol) replaced A1 and B1, and the final product C13 was obtained: 7.5 g (yield: 53%), MS (m / z) (M+): 711.

[0087] Comparative Examples 1-4

[0088] The structures of the compounds tried during the research are shown below:

[0089]

[0090] Material performance evaluation 1

[0091] The binding effect of organic compounds on metals is mainly related to the following aspects:

[0092] ① The number of coordination teeth of the compound: For multidentate ligands, that is, containing two or more coordinating atoms, the electron donor can provide two or more lone pairs of electrons, and the ligand and the coordination center ion form two or more coordination bonds. Utilizing the properties of multidentate ligands is conducive to the formation of coordination compounds with multidimensional network space structures. The compound structure described in this case, through phenanthroline and two substituted aromatic groups adjacent to phenanthroline nitrogen, constitutes a stable tetradentate ligand (the bold part in the C1 structure), which is more conducive to forming a stable structure with a coordination number of 8 with rare earth metals, that is, it is easy to form the situation that is most conducive to the stable coordination of rare earth metals.

[0093]

[0094] ② Competitive ligand: In the coordination compound of metal ions, the introduction of another coordination center changes the original spatial configuration to some extent. In this case, by introducing the phosphine oxide structure as a competitive ligand, the rare earth metal can be effectively bound and the drift voltage of the device can be improved.

[0095] ③ Maximum negative electrostatic potential (ESP) of the material: The presence of a strong electron-rich group near the coordination site will make the surrounding coordinating atoms less nucleophilic, affecting the coordination with the central metal atom. The nucleophilicity of an atom can be evaluated by the maximum negative electrostatic potential (ESP). The larger the absolute value of ESP, the stronger the nucleophilicity of the region of the molecule and the better the coordination with the metal atom.

[0096] Under B3LYP / 6-31G** conditions, ORCA was used to evaluate the ESP of the embodiments and comparative examples, and the results are shown in Table 1. From the calculation results, it can be seen that the structure described in this case has two extreme points, located in the middle position of the nitrogen atom of phenanthroline and the position of phosphine oxygen, and the absolute value of ESP of phosphine oxygen is significantly greater than that of phenanthroline. This shows that phosphine oxygen can effectively bind rare earth metal elements and has a strong coordination effect. When the phosphine oxygen group is directly connected to a large conjugated substituent such as naphthalene, or when larger condensed aromatic hydrocarbons such as anthracene, anthracene, and pyrene are present in the molecule, the substituent will significantly reduce the ESP of the material and affect the binding effect of phosphine oxygen on the material.

[0097] Table 1

[0098] Material No. Phenanthroline position EPS (eV) Phosphine oxygen position ESP (eV) C1 -1.90 -2.27 C2 -1.89 -2.20 C3 -1.87 -2.22 C4 -1.85 -2.13 C5 -1.92 -2.10 C6 -1.88 -2.19 C7 -1.85 -2.11 C8 -1.89 -2.18 D1 -1.86 -2.01 D2 -1.73 -2.02 D3 -1.88 -2.21 D4 -1.80 -

[0099] It can be seen from Table 1 that, compared with D1, the phosphine atom in the compound provided by the present invention is not directly connected to naphthalene, so the absolute value of ESP at the phosphine oxygen position is larger; compared with D2, the compound molecule provided by the present invention does not contain large condensed aromatic hydrocarbons such as anthracene, so the absolute value of ESP at the phosphine oxygen position is larger; compared with D3, the compound provided by the present invention limits the R1 group of the phenanthroline structure to phenyl or naphthyl, so that the phenanthroline fragment can coordinate with rare earth metals to form a tetradentate ligand, so the absolute value of EPS at the phenanthroline position is larger; compared with D4, the phosphine oxide structure fragment in the compound can improve the restriction ability to rare earth metals.

[0100] Material performance evaluation 2

[0101] During the experiment, it was found that the use of the phosphine-containing compound of formula II as an electron transport material and the compound of formula I as a CGL material in an organic light-emitting device can significantly reduce the energy required to inject electrons from the CGL layer to the electron transport layer due to their similar electronegativity.

[0102] The zero-field mobility of the CGL and ET materials described in this case was tested by the spatial confinement current method, which describes the electron transport capability of the material based on the current-voltage curve in the dark state. The zero-field mobility was obtained by linear fitting the curve obtained by the test. The sample preparation method is as follows:

[0103] The ITO substrate was mounted on the substrate holder of the vacuum deposition device and the pressure was adjusted to a vacuum rate of 1 × 10 - 7 Then, the following operations were performed according to the combination in Table 2: on the ITO layer (anode) formed on the substrate, 1 nm thick Yb, 100 nm thick CGL material (doped with 2 wt% Yb), 100 nm thick ET material, 1 nm thick Yb, and 100 nm thick Mg / Ag (Mg, Ag mass ratio is 1:9) were vacuum deposited in sequence.

[0104] Afterwards, a deflection voltage is applied to the sample to be tested, and the electric field strength-mobility characteristic curve of the sample is plotted. The intersection of the extended line of the curve and the Y-axis is the zero-field mobility of the sample. The results are shown in Table 2.

[0105] In addition to the materials used in the present invention, the molecular structures of the remaining materials in each layer of the device are as follows:

[0106]

[0107] Table 2

[0108]

[0109]

[0110] It can be seen from the above results that when the CGL material and the ET material provided by the present invention are used in combination, the electron mobility can be significantly enhanced.

[0111] Fabrication and characterization of OLEDs

[0112] Device Embodiment

[0113] The organic electroluminescent device provided by the present invention comprises an anode, a first hole transport region, a first luminescent layer, a first electron transport region, a charge generation region, a second hole transport region, a second luminescent layer, a second electron transport region, a cathode and a covering layer which are sequentially arranged on a substrate.

[0114] Further, the first hole transport region includes a hole injection layer, a first hole transport layer and a first electron blocking layer; the first electron transport region includes a first hole blocking layer and a first electron transport layer; the charge generation region includes an N-type charge generation layer and a P-type charge generation layer; the second hole transport region includes a second hole transport layer and a second electron blocking layer; the second electron transport region includes a second hole blocking layer, a second electron transport layer and an electron injection layer.

[0115] Furthermore, the light-emitting layer is composed of a main material and a doping material, and the main material of the light-emitting layer can be composed of one molecular material or multiple molecular materials.

[0116] The deuterated organic compound of the present invention can be used in one or more layers of the above-mentioned organic electroluminescent device, preferably in the N-type charge generation layer material of the device.

[0117] The anode in the embodiment adopts anode materials commonly used in the art, such as ITO, Ag or their multilayer structures. The hole injection layer adopts hole injection materials commonly used in the art, and F4TCNQ, HATCN, NDP-9, etc. are added for doping. The hole transport layer adopts hole transport materials commonly used in the art. The light-emitting layer adopts light-emitting materials and doping materials commonly used in the art, for example, it can be composed of a main material and a doping material. The electron transport layer adopts electron transport materials commonly used in the art. The electron injection layer adopts electron injection materials commonly used in the art, such as Liq, LiF, Yb, etc. The N-type charge generation layer material adopts a deuterated organic compound provided by the benzene invention. The cathode adopts materials commonly used in the art, such as metal Al, Ag or metal mixtures (Ag-doped Mg, Ag-doped Ca, etc.).

[0118] The electrode preparation method and the deposition method of each functional layer in this embodiment are conventional methods in the art, such as vacuum thermal evaporation or inkjet printing, etc., which will not be described in detail here. Only some process details and test methods in the preparation process are supplemented as follows:

[0119] Device Example 1

[0120] The substrates used in the present invention were subjected to the following operations: the ITO substrate was patterned so that its luminous area had a size of 3 mm×3 mm, and then water / isopropanol ultrasound, UV / ozone irradiation, and then dried at 100°C. After that, the ITO substrate was mounted on a substrate holder of a vacuum deposition device and the pressure was adjusted so that the vacuum rate became 1×10 -7 torr.

[0121] Then, the following operations were performed: first, HTL-1 and p-dopant-1 (the mass ratio of HTL-1 to p-dopant-1 was 97:3) were vacuum deposited on the ITO layer (anode) formed on the substrate with a thickness of 10 nm to form a hole injection layer; secondly, HTL-1 was vacuum deposited on the hole injection layer with a thickness of 20 nm to form a first hole transport layer; secondly, EB-1 was vacuum deposited on the first hole transport layer with a thickness of 5 nm to form a first electron blocking layer; and secondly, a mixture of BH-1 and BD-1 was vacuum deposited on the first electron blocking layer with a thickness of 20 nm to form a first light-emitting layer. , wherein BH-1 is used as a host and BD-1 is used as a dopant, and the mass ratio of the host to the dopant is 98:2; then, on the first light-emitting layer, HB-1 is vacuum deposited with a thickness of 5 nm to form a first hole blocking layer; then, on the first hole blocking layer, ETL-1:LiQ (the mass ratio of ETL-1 to LiQ is 1:1) is vacuum deposited with a thickness of 15 nm to form a first electron transport layer; then, on the first electron transport layer, C1 and Yb (the mass ratio of C1 to Yb is 98:2) are vacuum deposited with a thickness of 15 nm to form an N-type charge generation layer, and HTL-1 and p-d are vacuum deposited with a thickness of 10 nm. opant-1 (the mass ratio of HTL-1 to p-dopant-1 is 97:3) to form a P-type charge generation layer, and then on the above hole generation layer, HTL-1 is vacuum deposited with a thickness of 20nm to form a second hole transport layer, and then on the above second hole transport layer, EB-1 is vacuum deposited with a thickness of 5nm to form a second electron blocking layer, and then on the above second electron blocking layer, a mixture of BH-1 and BD-1 is vacuum deposited with a thickness of 20nm to form a second light-emitting layer, wherein BH-1 is used as a host and BD-1 is used as a dopant, and the mass ratio of the host to the dopant is 98:2; then on the above second light-emitting layer, a mixture of BH-1 and BD-1 is vacuum deposited with a thickness of 20nm to form a second light-emitting layer. layer, and HB-1 was vacuum deposited with a thickness of 5 nm to form a second hole blocking layer; then, ETL-1 and LiQ (the mass ratio of ETL-1 to LiQ is 1:1) were vacuum deposited with a thickness of 15 nm on the second hole blocking layer to form a second electron transport layer; then, Yb was deposited with a thickness of 1 nm on the second electron transport layer to form an electron injection layer, and then, Mg and Ag (the mass ratio of Mg to Ag is 1:9) were deposited with a thickness of 15 nm on the electron injection layer to form a cathode, and then, CPL-1 was deposited with a thickness of 50 nm on the cathode to form a covering layer, to prepare a stacked organic electroluminescent device.

[0122] In addition to the materials used in the present invention, the molecular structures of the remaining materials in each layer of the device are as follows:

[0123]

[0124] Device Examples 2-8

[0125] The above method is used to prepare the compound described in the example into an organic electroluminescent device, wherein C2 to C8 are used to replace C1 to prepare organic electroluminescent device examples 2-8.

[0126] Device Comparison Examples 1-4

[0127] The above method was used to prepare the compounds described in the examples into organic electroluminescent devices, wherein D1 to D4 were used to replace C1 to prepare organic electroluminescent device comparative examples 1-4.

[0128] The OLED devices described above were tested by standard methods. For this purpose, at J = 10 mA / cm 2 The driving voltage, brightness, electroluminescent current efficiency (measured in cd / A) and external quantum efficiency (EQE, measured in percentage) of the organic electroluminescent device are determined at a current density of 200 mA / cm2, which is calculated as a function of the luminous density from the current / voltage / luminous density characteristic line (IVL characteristic line) showing Lambertian emission characteristics. The lifespan LT is defined as the time after which the brightness drops from the initial luminous brightness L0 to a specific proportion L1 when operating at a constant current J; J = 20 mA / cm2 2 The expression L1 = 90% means that at 20 mA / cm 2 When working under LT, the luminance drops to 90% of its initial value L0 after time LT. Similarly, J = 20 mA / cm 2 , L1 = 95% means, at 20mA / cm 2 When working under LT, the luminous brightness drops to 95% of its initial value L0 after time LT. The drift voltage refers to the ratio of the difference between the voltage V1 after the device works for 150 hours and the initial voltage V0 of the device to the initial voltage V0, that is, drift voltage = (V1-V0) / V0. The driving voltage of the device is selected from the voltage V1 after the device works for 150 hours. The lower the drift voltage value, the better the reliability of the device. The lower the value, the less likely the device is to deteriorate with the extension of working time.

[0129] The data of various OLED devices are summarized in Table 3. Various parameters of the device examples and the device comparison examples are compared to show the performance data of various OLED devices.

[0130] The test instruments and methods for testing the performance of the OLED devices in the above embodiments and comparative examples are as follows:

[0131] Quantum efficiency CE (cd / A) and color coordinates (CIEy) were tested using a spectrum scanner PhotoResearch PR-635;

[0132] Current density and lighting voltage: tested using a digital source meter Keithley 2400;

[0133] Blue index is obtained by dividing the quantum efficiency CE (cd / A) by the color coordinate (CIEy);

[0134] Life test: Use LT-96ch life test device.

[0135] The performance test results of the above devices are listed in Table 3.

[0136] Table 3 Device performance test results

[0137]

[0138]

[0139]

[0140] From the above data, it can be seen that the compound provided by the present invention can significantly improve the drift voltage of the device by limiting the R1 group of the phenanthroline structure to phenyl or naphthyl, so that the phenanthroline fragment can coordinate with the rare earth metal to form a tetradentate ligand, and the restriction ability to the rare earth metal is improved by the phosphine oxide fragment. At the same time, since the compound provided by the present invention can enhance the coordination and binding ability to the metal and increase the stability of the n-CGL film layer, the driving voltage and life of the device are also significantly improved compared with the device in the comparative example.

[0141] Device Examples 9-27

[0142] The above method was used to prepare the compounds described in the examples into organic electroluminescent devices, wherein CGL materials and ET materials corresponding to Table 4 were used to replace C1 and ETL-1 to prepare organic electroluminescent device examples 9-27.

[0143] Device Comparison Examples 5-8

[0144] The above method was used to prepare the compounds described in the examples into organic electroluminescent devices, wherein CGL materials and ET materials corresponding to Table 4 were used to replace C1 and ETL-1 to prepare organic electroluminescent device comparative examples 5-8.

[0145] Table 4

[0146]

[0147]

[0148] When the phosphine-containing CGL material and the ET material provided in this case are used in combination, the injection barrier of the interface is reduced, the electron mobility can be significantly improved, and the device driving voltage can be reduced.

[0149] It can be seen from the above device performance test results that when the organic material of the present invention is used in an organic electroluminescent device, the driving voltage is significantly reduced compared with the comparative example.

[0150] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. An organic compound containing phenanthroline and a phosphine substituent, characterized in that: The organic compound is selected from the general structural formula shown in the following formula I: Wherein, the R1 is selected from substituted or unsubstituted phenyl or substituted or unsubstituted naphthyl; the substituent of R1 is selected from C1-C10 alkyl; The R2 and R3 are each independently selected from any one of hydrogen, methyl and phenyl; The L1 is selected from any one of substituted or unsubstituted phenyl and substituted or unsubstituted naphthyl; the substituent of L1 is selected from any one of C1-C10 alkyl, C3-C10 cycloalkyl, phenyl and naphthyl or any combination thereof.

2. The organic compound according to claim 1, characterized in that The organic compound is selected from one of the following structural formulas:

3. The organic compound according to claim 1, characterized in that The organic compound is selected from one of the following structural formulas:

4. The organic compound according to claim 1, characterized in that The organic compound is selected from one of the structures shown below:

5. An organic electroluminescent device, characterized in that: It includes an anode, a first hole transport region, a first light-emitting layer, a first electron transport region, a charge generation region, a second hole transport region, a second light-emitting layer, a second electron transport region, a cathode, and a covering layer, which are sequentially arranged on a substrate; wherein the charge generation region includes one or more organic compounds as described in any one of claims 1 to 4.

6. The organic electroluminescent device according to claim 5, characterized in that: The charge generation region includes an N-type charge generation layer and a P-type charge generation layer, the N-type charge generation layer is located between the P-type charge generation layer and the first electron transport region, wherein the N-type charge generation layer includes one or more organic compounds as described in any one of claims 1 to 4.

7. The organic electroluminescent device according to claim 5, characterized in that: The first electron transport region and / or the second electron transport region further comprises an organic compound represented by general formula II: Wherein, Ar1 and Ar2 are the same or different, and each independently represents one of phenyl and naphthyl; The ring A is selected from a substituted or unsubstituted phenyl, naphthyl, anthracenyl group; The substituent in the ring A is selected from any one or more of a C1-C10 alkyl group, a C3-C10 cycloalkyl group, a phenyl group, and a naphthyl group; The L2 is selected from any one of substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, and substituted or unsubstituted naphthyl; The substituent in L2 is selected from any one or more of a C1-C10 alkyl group, a C3-C10 cycloalkyl group, a phenyl group, and a naphthyl group.

8. The organic electroluminescent device according to claim 7, characterized in that: The ring A is selected from one of phenyl, naphthyl and anthracenyl; The substituent in L2 is selected from phenyl.

9. The organic electroluminescent device according to claim 5, characterized in that: The first electron transport region and / or the second electron transport region further includes one of the following structures:

10. A display or lighting device, characterized in that: The organic electroluminescent device comprises the organic electroluminescent device as claimed in any one of claims 5 to 9.

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