An organic electroluminescent device

Abstract

The present invention relates to an organic electroluminescent device, the organic electroluminescent device comprises a first electrode, a second electrode and an organic layer located between the first electrode and the second electrode, the organic layer comprises a light-emitting layer; the light-emitting layer comprises a host material and a guest material, the host material comprises a combination of a P-type material and an N-type material; the P-type material comprises any one or a combination of at least two of the compounds shown in formula (1). The present invention uses the P-type material of formula (1) in combination with the N-type material to reduce the proximity of the recombination center to the EBL, reduce the pressure of the EBL blocking excitons, balance the carriers, thereby reducing the driving voltage of the device, and improving the luminous efficiency and device life.

Description

Technical Field

[0001] The present invention relates to the technical field of organic electroluminescence, and in particular to an organic electroluminescence device. Background Art

[0002] In organic light-emitting diodes (OLEDs), the carrier balance of the host material affects device performance. Using only N-type host materials will result in short device life and instability. Currently, red and green phosphorescent hosts generally use dual hosts to balance carriers, increase the recombination area, and improve device performance. However, the use of dual hosts will increase the use of evaporation sources.

[0003] In recent years, people in the industry have been constantly trying and exploring to improve device efficiency and stability. Most of them seek new materials to improve device performance. A large number of novel materials have been developed for use in organic electroluminescent devices. Although there are certain improvements in device performance, there is still a large amount of carrier accumulation at the interface. There are also problems such as high device voltage and short life.

[0004] Therefore, there is an urgent need to develop organic electroluminescent devices with higher performance in this field. Summary of the invention

[0005] In view of the shortcomings of the prior art, one of the purposes of the present invention is to provide an organic electroluminescent device having a lower driving voltage, and higher luminous efficiency and lifespan.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] The present invention provides an organic electroluminescent device, the organic electroluminescent device comprising a first electrode, a second electrode and an organic layer located between the first electrode and the second electrode, the organic layer comprising a light-emitting layer (EML);

[0008] The light-emitting layer includes a host material and a guest material, wherein the host material includes a combination of a P-type material and an N-type material;

[0009] The P-type material includes any one or a combination of at least two of the compounds shown in formula (1);

[0010]

[0011] Wherein, X is selected from O, S, CR 5 R 6 NR 7 or SiR 8 R 9 ;

[0012] L 1Selected from single bonds, substituted or unsubstituted C6~C 30 arylene, substituted or unsubstituted C3~C 30 A heteroarylene group;

[0013] Ar 1 Selected from substituted or unsubstituted C6~C 30 Aryl or condensed ring aromatic group, substituted or unsubstituted C3~C 30 One of the heteroaryl or condensed-ring heteroaryl groups;

[0014] R 1 , R 2 and R 3 are independently selected from hydrogen, substituted or unsubstituted C6 to C 30 Aryl, substituted or unsubstituted C3~C 30 Heteroaryl, C1~C 30 Alkyl, C1~C 30 Alkoxy, C3~C 30 One of cycloalkyl, silyl and carbonyl; m, n, p and q are independently selected from zero to the maximum possible integer value;

[0015] R 4 Selected from substituted or unsubstituted C6~C 30 Aryl or condensed ring aromatic group, substituted or unsubstituted C3~C 30 and R 4 The benzene ring connected to it is connected by -O-, -S-, ~CR 10 R 11 -、-NR 12 -or-SiR 13 R 14 - connected to form a ring or not connected to form a ring;

[0016] In the above, “connecting into a ring” is an example: R 4 It is a phenyl group, and is connected to the connecting benzene ring through -O- to form a ring, that is, a dibenzofuran structure is formed. Examples of "not connected to form a ring" are: R 4 is phenyl, and is not connected to the connected benzene ring to form a ring, that is, phenyl (R 4 ) is substituted on the benzene ring through a single bond.

[0017] The above R 5 To R 14 Each independently selected from hydrogen, C1-C 18 Alkyl, C1~C 18 Alkoxy, C3~C 30 Cycloalkyl, C3~C 18 Alkenyl, C3~C 18 Alkynyl, halogen, cyano, substituted or unsubstituted C6~C30 Aryl, substituted or unsubstituted C3~C 30 Heteroaryl, substituted or unsubstituted C6~C 30 Aromatic amino, substituted or unsubstituted C3~C 30 One of the heteroarylamine groups;

[0018] L 1 ,Ar 1 , R 1 -R 14 The substituted groups are independently selected from halogen, C1-C 10 Alkyl or cycloalkyl, C2~C 10 alkenyl, C1-C6 alkoxy or thioalkoxy group, cyano, nitro, amine, carboxyl, carbonyl, ester, C6-C 30 Monocyclic aromatic hydrocarbons or condensed aromatic hydrocarbon groups, C3~C 30 A combination of one or more monocyclic heteroaromatic hydrocarbon groups or condensed-ring heteroaromatic hydrocarbon groups.

[0019] The present invention provides a novel organic electroluminescent device, wherein a P-type material and an N-type material shown in formula (1) are selected to form a main body of a light-emitting layer. The combination of the two can reduce the proximity of a recombination center to an electron blocking layer (EBL), reduce the pressure of the EBL blocking excitons, and balance the carriers, thereby reducing the driving voltage of the device, improving the luminous efficiency and the life of the device.

[0020] In the present invention, P-type material, also called hole-type material, is a material whose hole concentration is much greater than the free electron concentration; N-type material, also called electron-type material, is a material whose free electron concentration is much greater than the hole concentration. The definitions of these two materials are common knowledge to those skilled in the art.

[0021] In the present invention, the heteroatom of the heteroaryl group is usually selected from N, O, and S.

[0022] In the present invention, the expression of a ring structure crossed by “—” indicates that the connection site is any position on the ring structure that can form a bond.

[0023] In the present invention, C6~C 30 Arylene, C6~C 30 The carbon number of the aryl group or condensed ring aryl group can be C10, C12, C14, C16, C18, C20, C26, C28, etc.; C3 to C 30 Sub-heteroaromatic, C3~C 30 The carbon number of the heteroaryl or condensed ring heteroaryl may be C3, C4, C6, C8, C10, C12, C14, C16, C18, C20, C26, C28, etc.; C6 to C 30The carbon number of the aromatic amine group can be C10, C12, C14, C16, C18, C20, C26, C28, etc.; C3~C 30 The carbon number of the heteroarylamine group can be C3, C4, C6, C8, C10, C12, C14, C16, C18, C20, C26, C28, etc. 30 Alkyl or C1~C 30 The carbon number of the alkoxy group can be C2, C3, C4, C5, C6, C7, C8, C9, C10, C12, C14, C16, C18, C20, C26, C28, etc.; C3 to C 30 The carbon number of the cycloalkyl group can be C4, C5, C6, C7, C8, C9, C10, etc.; C1 to C 18 Alkyl, C1~C 18 The carbon number of the alkoxy group can be C2, C3, C4, C5, C6, C7, C8, C9, C10, C12, C14, C16, etc.; C3 to C 18 Alkenyl, C3~C 18 The carbon number of the alkynyl group may be C3, C4, C5, C6, C7, C8, C9, C10, C12, C14, C16, etc. The above carbon numbers are only examples and are not limited to the above.

[0024] Preferably, the P-type material comprises any one or a combination of at least two of the compounds shown in formula (2);

[0025]

[0026] In formula (2), X is selected from O, S or CR 5 R 6 ;

[0027] L 1 Selected from single bonds, substituted or unsubstituted C6~C 30 arylene, substituted or unsubstituted C3~C 30 A heteroarylene group;

[0028] Ar 1 Selected from substituted or unsubstituted C6~C 30 Aryl or condensed ring aromatic group, substituted or unsubstituted C3~C 30 One of the heteroaryl or condensed-ring heteroaryl groups;

[0029] R 4 Selected from substituted or unsubstituted C6~C 30 Aryl or condensed ring aromatic group, substituted or unsubstituted C3~C 30 and R 4 The benzene ring connected to it is connected by -O-, -S-, -CR10 R 11 -、-NR 12 -or-SiR 13 R 14 - connected to form a ring or not connected to form a ring;

[0030] R 1 , R 2 and R 3 are independently selected from hydrogen, substituted or unsubstituted C6 to C 30 Aryl, substituted or unsubstituted C3~C 30 Heteroaryl, C1~C 30 Alkyl, C1~C 30 Alkoxy, C3~C 30 One of cycloalkyl, silyl and carbonyl; m, n, p and q are independently selected from zero to the maximum possible integer value;

[0031] The above R 5 , R 6 and R 10 To R 14 Each independently selected from hydrogen, C1-C 18 Alkyl, C1~C 18 Alkoxy, C3~C 30 Cycloalkyl, C3~C 18 Alkenyl, C3~C 18 Alkynyl, halogen, cyano, substituted or unsubstituted C6~C 30 Aryl, substituted or unsubstituted C3~C 30 Heteroaryl, substituted or unsubstituted C6~C 30 Aromatic amino, substituted or unsubstituted C3~C 30 One of the heteroarylamine groups;

[0032] L 1 ,Ar 1 , R 1 -R 6 , R 10 -R 14 The substituted groups are independently selected from halogen, C1-C 10 Alkyl or cycloalkyl, C2-C 10 alkenyl, C1-C6 alkoxy or thioalkoxy group, cyano, nitro, amine, carboxyl, carbonyl, ester, C6-C 30 Monocyclic aromatic hydrocarbons or condensed aromatic hydrocarbon groups, C3-C 30 One of the monocyclic heteroaromatic hydrocarbon or condensed heteroaromatic hydrocarbon groups.

[0033] Preferably, the P-type material comprises any one or a combination of at least two of the compounds shown in formula (3);

[0034]

[0035] In formula (3): X is selected from CR 5 R 6 ,

[0036] L 1 Selected from single bonds, substituted or unsubstituted C6-C 30 arylene, substituted or unsubstituted C3~C 30 A heteroarylene group;

[0037] Ar 1 Selected from substituted or unsubstituted C6~C 30 Aryl or condensed ring aromatic group, substituted or unsubstituted C3~C 30 One of the heteroaryl or condensed-ring heteroaryl groups;

[0038] R 1 , R 2 and R 3 are independently selected from hydrogen, substituted or unsubstituted C6 to C 30 Aryl, substituted or unsubstituted C3~C 30 Heteroaryl, substituted or unsubstituted C1~C 30 Alkyl, substituted or unsubstituted C1~C 30 Alkoxy, substituted or unsubstituted C3~C 30 Cycloalkyl, substituted or unsubstituted C1~C 30 One of a silane group and a carbonyl group; m, n, p and q are independently selected from zero to the maximum possible integer value;

[0039] R 4 Selected from substituted or unsubstituted C6~C 30 Aryl or condensed ring aromatic group, substituted or unsubstituted C3~C 30 and R 4 The benzene ring connected to it is connected by -O-, -S-, -CR 10 R 11 -、-NR 12 -or-SiR 13 R 14 - connected to form a ring or not connected to form a ring;

[0040] The above R 5 , R 6 and R 10 To R 14 Each independently selected from hydrogen, C1-C 18 Alkyl, C1~C 18 Alkoxy, C3~C 30 Cycloalkyl, C2~C18 Alkenyl, C2~C 18 Alkynyl, halogen, cyano, substituted or unsubstituted C6~C 30 Aryl, substituted or unsubstituted C3~C 30 Heteroaryl, substituted or unsubstituted C6~C 30 Aromatic amino, substituted or unsubstituted C3~C 30 One of the heteroaromatic amine groups; R 5 and R 6 Preferably C1~C 18 Alkyl, more preferably methyl;

[0041] L 1 ,Ar 1 , R 1 -R 6 , R 10 -R 14 The substituted groups are independently selected from halogen, C1-C 10 Alkyl, C3~C 10 Cycloalkyl, C2-C 10 alkenyl, C1-C6 alkoxy or thioalkoxy group, cyano, nitro, amine, carboxyl, carbonyl, ester, C6-C 30 Monocyclic aromatic hydrocarbons or condensed aromatic hydrocarbon groups, C3-C 30 One of the monocyclic heteroaromatic hydrocarbon or condensed heteroaromatic hydrocarbon groups.

[0042] Preferably, the P-type material comprises any one or a combination of at least two of the compounds shown in formula (4);

[0043]

[0044] In formula (4): X is selected from CR 5 R 6 ,

[0045] L 1 Selected from single bonds, substituted or unsubstituted C6-C 30 arylene, substituted or unsubstituted C3~C 30 A heteroarylene group;

[0046] Ar 1 Selected from substituted or unsubstituted C6~C 30 Aryl or condensed ring aromatic group, substituted or unsubstituted C3~C 30 One of the heteroaryl or condensed-ring heteroaryl groups;

[0047] R 1 , R 2 and R 3 are independently selected from hydrogen, substituted or unsubstituted C6 to C 30Aryl, substituted or unsubstituted C3~C 30 Heteroaryl, substituted or unsubstituted C1~C 30 Alkyl, substituted or unsubstituted C1~C 30 Alkoxy, substituted or unsubstituted C3~C 30 Cycloalkyl, substituted or unsubstituted C1~C 30 One of a silane group and a carbonyl group; m, n, p and q are independently selected from zero to the maximum possible integer value;

[0048] R 4 Selected from substituted or unsubstituted C6~C 30 Aryl or condensed ring aromatic group, substituted or unsubstituted C3~C 30 and R 4 The benzene ring connected to it is connected by -O-, -S-, -CR 10 R 11 -、-NR 12 -or-SiR 13 R 14 - connected to form a ring or not connected to form a ring;

[0049] The above R 5 , R 6 and R 10 To R 14 Each independently selected from hydrogen, C1-C 18 Alkyl, C1~C 18 Alkoxy, C3~C 30 Cycloalkyl, C2~C 18 Alkenyl, C2~C 18 Alkynyl, halogen, cyano, substituted or unsubstituted C6~C 30 Aryl, substituted or unsubstituted C3~C 30 Heteroaryl, substituted or unsubstituted C6~C 30 Aromatic amino, substituted or unsubstituted C3~C 30 One of the heteroaromatic amine groups; R 5 and R 6 Preferably C1~C 18 Alkyl, more preferably methyl;

[0050] L 1 ,Ar 1 , R 1 -R 6 , R 10 -R 14 The substituted groups are independently selected from halogen, C1-C 10 Alkyl, C3~C 10 Cycloalkyl, C2-C 10alkenyl, C1-C6 alkoxy or thioalkoxy group, cyano, nitro, amine, carboxyl, carbonyl, ester, C6-C 30 Monocyclic aromatic hydrocarbons or condensed aromatic hydrocarbon groups, C3-C 30 One of the monocyclic heteroaromatic hydrocarbon or condensed heteroaromatic hydrocarbon groups.

[0051] Preferably, the L 1 is selected from a single bond or phenylene.

[0052] Preferably, the Ar 1 The invention is selected from one of phenyl, biphenyl, terphenyl, naphthyl, phenanthryl, anthracenyl, fluoranthene, carbazole, fluorene, dibenzofuran and dibenzothiophene, or a combination of these groups.

[0053] Preferably, the R 4 A group selected from one or at least two of phenyl, biphenyl, terphenyl, naphthyl, fluorene, anthracene, phenanthryl, fluoranthenyl, carbazole, dibenzofuran, and dibenzothiophene, preferably phenyl or biphenyl.

[0054] Preferably, the R 1 To R 3each independently selected from H, or selected from the following substituted or unsubstituted groups: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, n-pentyl, sec-pentyl, cyclopentyl, neopentyl, n-hexyl, cyclohexyl, neohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, phenyl, naphthyl, anthracenyl, benzanthryl, phenanthrenyl, triphenylenyl, pyrenyl, chrysene, peryl, fluoranthenyl, naphthyl, pentacene, benzopyrenyl, biphenyl, phenylene, terphenyl, triphenylene, quaternaryl, fluorenyl , spirobifluorenyl, dihydrophenanthryl, dihydropyrenyl, tetrahydropyrenyl, cis- or trans-indenofluorenyl, trimerized indenyl, isotrimerized indenyl, spirotrimerized indenyl, spiroisotrimerized indenyl, furanyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, thienyl, benzothienyl, isobenzothienyl, dibenzothienyl, pyrrolyl, isoindolyl, carbazolyl, indenocarbazolyl, pyridinyl, quinolyl, isoquinolyl, acridinyl, phenanthridinyl, benzo-5,6-quinolyl, benzo-6,7-quinolyl, benzo-7,8-quinolyl, phenothiazinyl, phenazinyl, pyrazolyl, indazolyl, imidazolyl, benzimidazolyl, naphthoimidazolyl, phenanthrene imidazolyl, pyridinimidazolyl, pyrazinimidazolyl, quinoxalinimidazolyl, oxazolyl, benzoxazolyl, naphthoxazolyl, anthrazolyl, phenanthrozolyl, 1,2-thiazolyl, 1,3-thiazolyl, benzothiazolyl, pyridazinyl, benzopyridazinyl, pyrimidinyl, benzopyrimidinyl, quinoxalinyl, 1,5-diazaanthryl, 2,7-diazapyrenyl, 2,3-diazapyrenyl, 1,6-diazapyrenyl, 1,8-diazapyrenyl, 4,5-diazapyrenyl, 4,5,9,10-tetraazaperyl, pyrazinyl, phenazinyl, phenothiazinyl, naphthyridinyl, azacarbazolyl, benzocarbolinyl, phenanthroline A group formed by connecting one or at least two of the following: 1,2,3-triazolyl, 1,2,4-triazolyl, benzotriazolyl, 1,2,3-oxadiazolyl, 1,2,4-oxadiazolyl, 1,2,5-oxadiazolyl, 1,2,3-thiadiazolyl, 1,2,4-thiadiazolyl, 1,2,5-thiadiazolyl, 1,3,4-thiadiazolyl, 1,3,5-triazinyl, 1,2,4-triazinyl, 1,2,3-triazinyl, tetrazolyl, 1,2,4,5-tetrazinyl, 1,2,3,4-tetrazinyl, 1,2,3,5-tetrazinyl, purinyl, pteridinyl, indolizinyl and benzothiadiazolyl.

[0055] Preferably, the P-type material includes any one or a combination of at least two of the compounds shown in C1 to C822.

[0056] In the present invention, the representative synthesis route of the compound of formula (1) is as follows:

[0057]

[0058] It should be noted that the method and route for obtaining the compound are not limited to the method and route used in the present invention, and those skilled in the art may also select other methods or routes to obtain the compound of formula (1).

[0059] Preferably, the hole mobility of the P-type material is 10 -5 ~10 -2 cm 2 / v / s, for example 2×10 -5 cm 2 / v / s, 3×10 -5 cm 2 / v / s, 4×10 -5 cm 2 / v / s, 5×10 -5 cm 2 / v / s, 6×10 -5 cm 2 / v / s, 7×10 -5 cm 2 / v / s, 8×10 -5 cm 2 / v / s, 9×10 -5 cm 2 / v / s, 10 -4 cm 2 / v / s, 2×10 -4 cm 2 / v / s, 3×10 -4 cm 2 / v / s, 4×10 -4 cm 2 / v / s, 5×10 - 4 cm 2 / v / s, 6×10 -4 cm 2 / v / s, 7×10 -4 cm 2 / v / s, 8×10 -4 cm 2 / v / s, 9×10 -4 cm 2 / v / s, 10 -3 cm 2 / v / s, 2×10 -3 cm 2 / v / s, 3×10 -3 cm 2 / v / s, 4×10 -3 cm 2 / v / s, 5×10 -3 cm 2 / v / s, 6×10-3 cm 2 / v / s, 7×10 - 3 cm 2 / v / s, 8×10 -3 cm 2 / v / s, 9×10 -3 cm 2 / v / s, etc.

[0060] Preferably, the glass transition temperature of the P-type material is greater than 100°C, for example, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, etc., preferably greater than 130°C.

[0061] In the preferred embodiment, the glass transition temperature of the selected compound is relatively high, which can ensure that the compound can form a dense film in a non-crystalline form after evaporation, thereby improving the stability of device performance. At the same time, its hole mobility is high, which can reduce the proximity of the recombination center to the EBL and reduce the pressure of the EBL blocking excitons.

[0062] The present invention prefers compound C4 as a P-type material, whose glass transition temperature is greater than 130°C and hole mobility is within 10 -4 ~10 -2 cm 2 / v / s.

[0063] Preferably, in the light-emitting layer, the thickness ratio of the P-type material to the N-type material is 10:1 to 1:10, for example, 9:1, 8:1, 7:1, 6:1, 5:1, 4:1, 3:1, 2:1, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, etc., preferably 5:1 to 1:5. In the present invention, when evaporating the light-emitting layer, it is preferred that the evaporation rate ratio of the P-type material to the N-type material is 10:1 to 1:10, and the evaporation rate unit is nm / s, so that the thickness ratio of the P-type material and the N-type material is 10:1 to 1:10.

[0064] The present invention preferably has a thickness ratio of P-type material to N-type material of 10:1 to 1:10, that is, a ratio of the evaporation rate of P-type material to N-type material of 10:1 to 1:10. Within this range, the device can have the best luminous efficiency, driving voltage and life. Too much or too little P-type material will lead to an imbalance of carriers in the light-emitting layer, thereby reducing efficiency and shortening life.

[0065] Preferably, the organic layer comprises an organic functional layer and a light-emitting layer, the organic functional layer comprises an electron blocking layer, and the electron blocking layer contains any one or a combination of at least two of the compounds represented by formula (1).

[0066] In the present invention, the first electrode is an anode and the second electrode is a cathode, or the first electrode is a cathode and the second electrode is an anode.

[0067] In the present invention, it is preferred that the electron blocking layer is disposed between the anode and the light-emitting layer.

[0068] In a preferred technical solution of the present invention, the electron blocking layer also contains the compound of formula (1), which can further increase the interface stability between the EBL and the EML, balance the carriers, and improve the device performance.

[0069] Preferably, the electron blocking material in the electron blocking layer has the same chemical structure as any one of the P-type materials in the light-emitting layer.

[0070] Furthermore, the present invention preferably uses the same P-type material in the electron blocking layer and the light-emitting layer, which can not only save evaporation sources but also increase the interface stability between the EBL and the EML, balance the carriers, and improve the device performance.

[0071] Preferably, the N-type material is selected from any one or a combination of at least two of the following compounds GPH-1 to GPH-80:

[0072]

[0073]

[0074]

[0075]

[0076] Preferably, the N-type material includes an N-type green light material or an N-type red light material.

[0077] Preferably, the N-type green light material is selected from any one or a combination of at least two of the following compounds GPH-1 to GPH-80:

[0078]

[0079]

[0080]

[0081] Preferably, the N-type red light material is selected from any one or a combination of at least two of the following compounds RH-1 to RH-31:

[0082]

[0083] Preferably, the organic functional layer further comprises any one of a hole injection layer, a hole transport layer, a hole blocking layer, an electron transport layer or an electron injection layer, or a combination of at least two of them, preferably a combination of a hole injection layer, a hole transport layer, an electron transport layer and an electron injection layer.

[0084] The organic electroluminescent device of the present invention is prepared by vacuum evaporation, and can also be prepared by other methods, not limited to vacuum deposition. The present invention is described only by using the device prepared by vacuum deposition.

[0085] The preparation method includes substrate cleaning, drying, pretreatment, cavity entry, and sequential vacuum deposition of a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer (electron injection layer), a cathode, and a light extraction layer.

[0086] Among them, the substrate is a rigid substrate or a flexible substrate. The rigid substrate includes a glass substrate, a Si substrate, etc., and the flexible substrate includes a polyvinyl alcohol (PVA) film, a polyimide (PD) film, a polyester (PET) film, etc.; the substrate of the present invention is preferably a rigid glass substrate.

[0087] The anode may preferably be a conductive compound, alloy, metal, or a mixture of such materials having a large work function. Inorganic materials may be used, including metals or metal oxides, laminates formed by alternating metals and metals or metals and non-metals, etc. Metal oxides include indium tin oxide (ITO), zinc oxide (ZnO), indium zinc oxide (IZO), tin oxide (SnO), etc. Metals include gold, silver, copper, aluminum, etc. having a relatively high work function; the anode of the present invention is preferably ITO.

[0088] The hole injection layer uses 6% F4TCNQ doped with MATADA, and the structure is as follows:

[0089]

[0090] The raw material for preparing the hole transport layer is N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine (NPB).

[0091] The green dye is selected from any one or a combination of at least two of the following compounds GPD-1 to GPD-12:

[0092]

[0093] The red dye is selected from any one or a combination of at least two of the compounds shown in the following RPD-1 to RPD-10:

[0094]

[0095] The electron transport layer is made by blending two materials, and the main material is selected from any one or a combination of at least two of the compounds shown in the following ET-1 to ET-5:

[0096]

[0097] The electron transport layer doping materials are:

[0098]

[0099] The cathode is a metal such as magnesium-silver mixture, LiF / Al, ITO, a metal mixture, an oxide, etc., and the present invention preferably uses a Yb / magnesium-silver mixture.

[0100] Compared with the prior art, the present invention has the following beneficial effects:

[0101] The present invention provides a novel organic electroluminescent device, wherein a P-type material and an N-type material shown in formula (1) are selected to form a main body of a light-emitting layer. The combination of the two can reduce the proximity of the recombination center to the EBL, reduce the pressure of the EBL blocking excitons, balance the carriers, thereby reducing the driving voltage of the device, and improving the luminous efficiency and device life. BRIEF DESCRIPTION OF THE DRAWINGS

[0102] Figure 1 is a schematic structural diagram of an organic electroluminescent device provided in Example 1 of the present invention;

[0103] Among them, 1-anode, 2-hole injection layer, 3-hole transport layer, 4-electron blocking layer, 5-light-emitting layer, 6-electron transport layer, 7-electron injection layer, 8-cathode. DETAILED DESCRIPTION

[0104] 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.

[0105] The compounds of general formula (1) used in the following examples were prepared by the method disclosed in patent application CN110317139A. Those skilled in the art can also prepare them by other existing technologies, and the preparation method will not be described in detail in the present invention.

[0106] Example 1

[0107] This embodiment provides an organic electroluminescent device, and the preparation method is as follows:

[0108] On an anode glass substrate with a film thickness of 150 nm formed of indium tin oxide (ITO) / Ag / indium tin oxide (ITO), a vacuum evaporation method was used. When the vacuum degree reached 2×10 -4Each film layer was deposited at 1000 Pa. First, a MATADA:6% F4TCNQ film was formed on ITO (6% refers to the doping ratio of F4TCNQ in the hole injection layer). The evaporation rate ratio of MATADA to F4-TCNQ was 1:0.06, the evaporation rate of MATADA was 1 angstrom / second, and the total thickness was 100nm; then 10nm of NPB was deposited at a evaporation rate of 1 angstrom / second. Compound C4 was evaporated on the hole transport layer NPB as the electron blocking layer of the device. The evaporation rate was 0.1nm / s, and the total evaporation film thickness was 35nm. Compound C4, N-type green light host GPH-1 and 5% dye GPD-1 (5% refers to the doping ratio of the dye in the light-emitting layer) are co-evaporated from different evaporation sources as the green light-emitting layer, and the evaporation rate ratio is 3:1:0.1. The evaporation rate of C4 is 1 angstrom / second, and the thickness of the green light-emitting layer is 40nm; 25nm thick ET-1:Liq is deposited as the electron transport layer, the ratio is 1:1, and the evaporation rate is 1 angstrom / second; then 1nm LiF is deposited as the electron injection layer, and the evaporation rate is 0.1 angstrom / second; a 150nm thick Al layer is used as the cathode of the device.

[0109] The structure of the organic electroluminescent device provided in Example 1 is as follows Figure 1 As shown, it includes an anode 1, a hole injection layer 2, a hole transport layer 3, an electron blocking layer 4, a light-emitting layer 5, an electron transport layer 6, an electron injection layer 7 and a cathode 8.

[0110] Example 2

[0111] The only difference from Example 1 is that the evaporation rates of compound C4, N-type green light host GPH-1 and dye GPD-1 are 10:1:0.1.

[0112] Example 3

[0113] The only difference from Example 1 is that the evaporation rates of compound C4, N-type green light host GPH-1 and dye GPD-1 are 7:1:0.1.

[0114] Example 4

[0115] The only difference from Example 1 is that the evaporation rates of compound C4, N-type green light host GPH-1 and dye GPD-1 are 5:1:0.1.

[0116] Example 5

[0117] The only difference from Example 1 is that the evaporation rates of compound C4, N-type green light host GPH-1 and dye GPD-1 are 1:1:0.1.

[0118] Example 6

[0119] The only difference from Example 1 is that the evaporation rates of compound C4, N-type green light host GPH-1 and dye GPD-1 are 1:2:0.1, and the evaporation rate of the N-type host is 1 angstrom / second.

[0120] Example 7

[0121] The only difference from Example 1 is that the evaporation rates of compound C4, N-type green light host GPH-1 and dye GPD-1 are 1:5:0.1, and the evaporation rate of the N-type host is 1 angstrom / second.

[0122] Example 8

[0123] The only difference from Example 1 is that the evaporation rates of compound C4, N-type green light host GPH-1 and dye GPD-1 are 1:8:0.1, and the evaporation rate of the N-type host is 1 angstrom / second.

[0124] Example 9

[0125] The only difference from Example 1 is that the evaporation rates of compound C4, N-type green light host GPH-1 and dye GPD-1 are 1:10:0.1, and the evaporation rate of the N-type host is 1 angstrom / second.

[0126] Example 10

[0127] The only difference from Example 1 is that compound C4 is replaced by a mixture of compounds C4 and C34, the mass ratio of C4 to C34 is 1:1, and the evaporation rate of the mixture is 1 angstrom / second.

[0128] Embodiment 11

[0129] An OLED organic electroluminescent device, the preparation method is as follows:

[0130] On an anode glass substrate with a film thickness of 150 nm formed of indium tin oxide (ITO) / Ag / indium tin oxide (ITO), a vacuum evaporation method was used. When the vacuum degree reached 2×10 -4Each film layer was deposited under 1000 Pa. First, a MATADA:6% F4TCNQ film was formed on ITO, the evaporation rate ratio of MATADA to F4-TCNQ was 1:0.06, the evaporation rate of MATADA was 1 angstrom / second, and the total thickness was 140nm; then 20nm of NPB was deposited at a evaporation rate of 1 angstrom / second; compound C4 was evaporated on the hole transport layer NPB as the electron blocking layer of the device, the evaporation rate was 0.1nm / s, and the total evaporation film thickness was 90nm. Compound C4, N-type red light host RH-1 and 5% dye RPD-1 were co-evaporated from different evaporation sources as the red light emitting layer, with an evaporation rate ratio of 3:1:0.05, an evaporation rate of C4 of 1 angstrom / second, and a thickness of the red light emitting layer of 35nm; 25nm thick ET-1:Liq was deposited as an electron transport layer with a ratio of 1:1 and an evaporation rate of 1 angstrom / second; then 1nm LiF was deposited as an electron injection layer with an evaporation rate of 0.1 angstrom / second; a 150nm thick Al layer was used as the cathode of the device.

[0131] Example 12

[0132] The only difference from Example 11 is that the evaporation rates of compound C4, N-type red light host RH-1 and dye RPD-1 are 10:1:0.1.

[0133] Embodiment 13

[0134] The only difference from Example 11 is that the evaporation rates of compound C4, N-type red light host RH-1 and dye RPD-1 are 7:1:0.1.

[0135] Embodiment 14

[0136] The only difference from Example 11 is that the evaporation rates of compound C4, N-type red light host RH-1 and dye RPD-1 are 5:1:0.1.

[0137] Embodiment 15

[0138] The only difference from Example 11 is that the evaporation rates of compound C4, N-type red light host RH-1 and dye RPD-1 are 1:1:0.1.

[0139] Example 16

[0140] The only difference from Example 11 is that the evaporation rates of compound C4, N-type red light host RH-1 and dye RPD-1 are 1:2:0.1, and the evaporation rate of the N-type host is 1 Å / s.

[0141] Embodiment 17

[0142] The only difference from Example 11 is that the evaporation rates of compound C4, N-type red light host RH-1 and dye RPD-1 are 1:5:0.1, and the evaporation rate of the N-type host is 1 Å / s.

[0143] Embodiment 18

[0144] The only difference from Example 11 is that the evaporation rates of compound C4, N-type red light host RH-1 and dye RPD-1 are 1:8:0.1, and the evaporation rate of the N-type host is 1 Å / s.

[0145] Embodiment 19

[0146] The only difference from Example 11 is that the evaporation rates of compound C4, N-type red light host RH-1 and dye RPD-1 are 1:10:0.1, and the evaporation rate of the N-type host is 1 Å / s.

[0147] Embodiment 20

[0148] The only difference from Example 11 is that compound C4 is replaced by a mixture of compounds C4 and C34, the mass ratio of C4 to C34 is 1:1, and the evaporation rate of the mixture is 1 angstrom / second

[0149] Embodiment 21

[0150] The only difference from Example 1 is that the evaporation rates of compound C4, N-type green light host GPH-1 and dye GPD-1 are 12:1:0.1.

[0151] Embodiment 22

[0152] The only difference from Example 1 is that the evaporation rates of compound C4, N-type green light host GPH-1 and dye GPD-1 are 1:12:0.1, and the evaporation rate of the N-type host is 1 angstrom / second.

[0153] Embodiment 23

[0154] The only difference from Example 11 is that the evaporation rates of compound C4, N-type red light host RH-1 and dye RPD-1 are 12:1:0.1.

[0155] Embodiment 24

[0156] The only difference from Example 11 is that the evaporation rates of compound C4, N-type red light host RH-1 and dye RPD-1 are 1:12:0.1, and the evaporation rate of the N-type host is 1 Å / s.

[0157] Embodiment 25

[0158] The only difference from Example 1 is that the compound C4 in the electron blocking layer is replaced by the compound C235.

[0159] Embodiment 26

[0160] The only difference from Example 1 is that the compound C4 in the electron blocking layer is replaced by HBL1

[0161]

[0162] Comparative Example 1

[0163] The only difference from Example 1 is that in this example, the light-emitting layer uses only an N-type green light host, and does not use compound C4.

[0164] Comparative Example 2

[0165] The only difference from Example 11 is that in this example, the light-emitting layer uses only an N-type red light host, and does not use compound C4.

[0166] Comparative Example 3

[0167] The only difference from Example 1 is that the compound C4 in the light-emitting layer is replaced by a P-type host material P1.

[0168]

[0169] Comparative Example 4

[0170] The only difference from Example 11 is that the compound C4 in the light-emitting layer is replaced by a P-type host material P2.

[0171]

[0172] Performance Testing

[0173] (1) Under the same brightness, the driving voltage and current efficiency of the organic electroluminescent devices prepared in the examples and comparative examples and the life of the devices were measured using a PR 750 photoradiometer, ST-86LA luminance meter (Beijing Normal University Photoelectric Instrument Factory) and Keithley 4200 test system. Specifically, the voltage was increased at a rate of 0.1 V per second to measure the brightness of the organic electroluminescent device at a blue light level of 1000 cd / m 2 , green light 10000cd / m 2 , red light 5000cd / m 2 The voltage at this time is the driving voltage (V), and the current density at this time is measured at the same time; the ratio of brightness to current density is the current efficiency (CE, cd / A);

[0174] (2) The life test of LT97 is as follows: using ST-86LA luminance meter (Beijing Normal University Optoelectronic Instrument Factory) with blue light at 3000cd / m 2 , green light at 20000cd / m 2 , red light at 10000cd / m 2 Under the brightness, maintain a constant current and measure the time for the brightness of the organic electroluminescent device to drop to 97% of the initial brightness, in hours.

[0175] The test results are shown in Table 1.

[0176] Table 1

[0177]

[0178]

[0179] As can be seen from Table 1, the present invention can reduce the driving voltage, improve the current efficiency, and significantly increase the lifespan by using the compound of formula (1) in combination with the N-type host. At the same time, it can reduce the process cost and improve the finished product yield of the OLED display device.

[0180] In Comparative Examples 1 and 2, no P-type host material is added, and in Comparative Examples 3 and 4, a P-type host material different from the present invention is added. The luminous efficiency, driving voltage and life of the devices in Comparative Examples 1 to 4 are all worse than those in the embodiment. This proves that the use of a P-type host material with a specific structure in the present invention in combination with an N-type host material can further improve device performance.

[0181] Comparing Examples 1 to 9 with Examples 21 to 22, when the ratio of P-type main material to N-type main material is 10:1 to 1:10 (Examples 1 to 9), the device performance is better, while too much P-type main material (Example 21) or too little (Example 22) will reduce the device performance. The same conclusion is obtained by Examples 11 to 19 and Examples 23 to 24.

[0182] By comparing Example 1 and Example 26, it can be seen that when the electron blocking layer material is also selected from the compound of formula (1) (Example 1), the device performance can be further improved.

[0183] (3) Glass transition temperature Tg and hole mobility test process of the P-type materials used in the embodiments and comparative examples:

[0184] The glass transition temperature Tg is tested by using a differential scanning calorimeter DSC, which outputs different powers to the measured object and the reference object, measures the relationship between this difference and temperature, and thus obtains the temperature at which the material changes from a highly elastic state to a glassy state, i.e., the glass transition temperature.

[0185] The hole mobility is measured by the TOF method, that is, a thin film device is prepared and a deflection voltage is applied; the laser is turned on, and the laser excites the material to generate photogenerated carriers; the carriers will move in a directed manner under the action of the electric field, and the oscilloscope records the relationship between the drift current and time and finally calculates the carrier mobility.

[0186] The above test results are shown in Table 2.

[0187] Table 2

[0188] Material Tg / ℃ <![CDATA[Hole mobility / cm 2 / V / s]]> C4 135 <![CDATA[7.2×10 -4 ]]> C34 145 <![CDATA[5.4×10 -4 ]]> C4, C34 mixture (1:1) 142 <![CDATA[6.5×10 -4 ]]>

[0189] The applicant declares that the present invention illustrates the detailed process equipment and process flow of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed process equipment and process flow, that is, it does not mean that the present invention must rely on the above-mentioned detailed process equipment and 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. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises a first electrode, a second electrode and an organic layer located between the first electrode and the second electrode, wherein the organic layer comprises a light-emitting layer; The light-emitting layer includes a host material and a guest material, wherein the host material includes a combination of a P-type material and an N-type material; The P-type material includes any one or a combination of at least two of the compounds shown in formula (1); Wherein, X is selected from O, S, CR 5 R 6 NR 7 or SiR 8 R 9 ; L 1 Selected from single bonds, substituted or unsubstituted C6~C 30 arylene, substituted or unsubstituted C3~C 30 A heteroarylene group; Ar 1 Selected from substituted or unsubstituted C6~C 30 Aryl or condensed ring aromatic group, substituted or unsubstituted C3~C 30 One of the heteroaryl or condensed-ring heteroaryl groups; R 1 , R 2 and R 3 are independently selected from hydrogen, substituted or unsubstituted C6 to C 30 Aryl, substituted or unsubstituted C3~C 30 Heteroaryl, C1~C 30 Alkyl, C1~C 30 Alkoxy, C3~C 30 One of a cycloalkyl group and a silyl group; m, n, p and q are independently selected from zero to the maximum possible integer value; R 4 Selected from substituted or unsubstituted C6~C 30 Aryl or condensed ring aromatic group, substituted or unsubstituted C3~C 30 and R 4 The benzene ring connected to it is connected by -O-, -S-, ~CR 10 R 11 -、-NR 12 -or-SiR 13 R 14 - connected to form a ring or not connected to form a ring; The above R 5 To R 14 Each independently selected from hydrogen, C1-C 18 Alkyl, C3~C 30 Cycloalkyl, C3~C 18 Alkenyl, substituted or unsubstituted C6~C 30 Aryl, substituted or unsubstituted C3~C 30 One of the heteroaryl groups; L 1 ,Ar 1 , R 1 -R 14 The substituted groups are independently selected from halogen, C1-C 10 alkyl or cycloalkyl, C1-C6 alkoxy or thioalkoxy group, cyano, nitro, amino, C6-C 30 Monocyclic aromatic hydrocarbons or condensed aromatic hydrocarbon groups, C3~C 30 A combination of one or more monocyclic heteroaromatic hydrocarbon groups or condensed-ring heteroaromatic hydrocarbon groups.

2. The organic electroluminescent device according to claim 1, characterized in that: The P-type material includes any one or a combination of at least two of the compounds shown in formula (2); In formula (2), X is selected from O, S or CR 5 R 6 ; L 1 Selected from single bonds, substituted or unsubstituted C6~C 30 arylene, substituted or unsubstituted C3~C 30 A heteroarylene group; Ar 1 Selected from substituted or unsubstituted C6~C 30 Aryl or condensed ring aromatic group, substituted or unsubstituted C3~C 30 One of the heteroaryl or condensed-ring heteroaryl groups; R 4 Selected from substituted or unsubstituted C6~C 30 Aryl or condensed ring aromatic group, substituted or unsubstituted C3~C 30 and R 4 The benzene ring connected to it is connected by -O-, -S-, -CR 10 R 11 -、-NR 12 -or-SiR 13 R 14 - connected to form a ring or not connected to form a ring; R 1 , R 2 and R 3 are independently selected from hydrogen, substituted or unsubstituted C6 to C 30 Aryl, substituted or unsubstituted C3~C 30 Heteroaryl, C1~C 30 Alkyl, C1~C 30 Alkoxy, C3~C 30 One of a cycloalkyl group and a silyl group; m, n, p and q are independently selected from zero to the maximum possible integer value; The above R 5 , R 6 and R 10 To R 14 Each independently selected from hydrogen, C1-C 18 Alkyl, C3~C 30 Cycloalkyl, C3~C 18 Alkenyl, substituted or unsubstituted C6~C 30 Aryl, substituted or unsubstituted C3~C 30 One of the heteroaryl groups; L 1 ,Ar 1 , R 1 -R 6 , R 10 -R 14 The substituted groups are independently selected from halogen, C1-C 10 alkyl or cycloalkyl, C1-C6 alkoxy or thioalkoxy group, cyano, nitro, amino, C6-C 30 Monocyclic aromatic hydrocarbons or condensed aromatic hydrocarbon groups, C3-C 30 One of the monocyclic heteroaromatic hydrocarbon or condensed heteroaromatic hydrocarbon groups.

3. The organic electroluminescent device according to claim 1 or 2, characterized in that: The L 1 is selected from a single bond or phenylene.

4. The organic electroluminescent device according to claim 1 or 2, characterized in that: The Ar 1 A group formed by connecting one or at least two selected from phenyl, biphenyl, terphenyl, naphthyl, phenanthryl, anthracenyl, fluoranthene, carbazole, fluorene, dibenzofuran and dibenzothiophene.

5. The organic electroluminescent device according to claim 1 or 2, characterized in that: The R 4 The group is selected from one or at least two of phenyl, biphenyl, terphenyl, naphthyl, fluorene, anthracene, phenanthryl, fluoranthenyl, carbazole, dibenzofuran and dibenzothiophene.

6. The organic electroluminescent device according to claim 5, characterized in that: The R 4 Selected from phenyl or biphenyl.

7. The organic electroluminescent device according to claim 1 or 2, characterized in that: The R 1 To R 3 each independently selected from H, or selected from the following substituted or unsubstituted groups: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, n-pentyl, sec-pentyl, cyclopentyl, neopentyl, n-hexyl, cyclohexyl, neohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, phenyl, naphthyl, anthracenyl, benzanthryl, phenanthrenyl, triphenylenyl, pyrenyl, chrysene, peryl, fluoranthenyl, naphthyl, pentacene, benzopyrenyl, biphenyl, phenylene, terphenyl, triphenylene, quaternaryl, fluorenyl , spirobifluorenyl, dihydrophenanthryl, dihydropyrenyl, tetrahydropyrenyl, cis- or trans-indenofluorenyl, trimerized indenyl, isotrimerized indenyl, spirotrimerized indenyl, spiroisotrimerized indenyl, furanyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, thienyl, benzothienyl, isobenzothienyl, dibenzothienyl, pyrrolyl, isoindolyl, carbazolyl, indenocarbazolyl, pyridinyl, quinolyl, isoquinolyl, acridinyl, phenanthridinyl, benzo-5,6-quinolyl, benzo-6,7-quinolyl, benzo-7,8-quinolyl, phenothiazinyl, phenazinyl, pyrazolyl, indazolyl, imidazolyl, benzimidazolyl, naphthoimidazolyl, phenanthrene imidazolyl, pyridinimidazolyl, pyrazinimidazolyl, quinoxalinimidazolyl, oxazolyl, benzoxazolyl, naphthoxazolyl, anthrazolyl, phenanthrozolyl, 1,2-thiazolyl, 1,3-thiazolyl, benzothiazolyl, pyridazinyl, benzopyridazinyl, pyrimidinyl, benzopyrimidinyl, quinoxalinyl, 1,5-diazaanthryl, 2,7-diazapyrenyl, 2,3-diazapyrenyl, 1,6-diazapyrenyl, 1,8-diazapyrenyl, 4,5-diazapyrenyl, 4,5,9,10-tetraazaperyl, pyrazinyl, phenazinyl, phenothiazinyl, naphthyridinyl, azacarbazolyl, benzocarbolinyl, phenanthroline A group formed by connecting one or at least two of the following: 1,2,3-triazolyl, 1,2,4-triazolyl, benzotriazolyl, 1,2,3-oxadiazolyl, 1,2,4-oxadiazolyl, 1,2,5-oxadiazolyl, 1,2,3-thiadiazolyl, 1,2,4-thiadiazolyl, 1,2,5-thiadiazolyl, 1,3,4-thiadiazolyl, 1,3,5-triazinyl, 1,2,4-triazinyl, 1,2,3-triazinyl, tetrazolyl, 1,2,4,5-tetrazinyl, 1,2,3,4-tetrazinyl, 1,2,3,5-tetrazinyl, purinyl, pteridinyl, indolizinyl and benzothiadiazolyl.

8. The organic electroluminescent device according to claim 1, characterized in that: The P-type material includes any one or a combination of at least two of the following compounds C1 to C822:

9. The organic electroluminescent device according to claim 1, characterized in that: The hole mobility of the P-type material is 10 -5 ~10 -2 cm 2 / v / s.

10. The organic electroluminescent device according to claim 1, characterized in that: In the light-emitting layer, the thickness ratio of the P-type material to the N-type material is 10:1 to 1:

10.

11. The organic electroluminescent device according to claim 10, characterized in that: In the light-emitting layer, the thickness ratio of the P-type material to the N-type material is 5:1 to 1:

5.

12. The organic electroluminescent device according to claim 1, characterized in that: The organic layer includes an organic functional layer and a light-emitting layer. The organic functional layer includes an electron blocking layer. The electron blocking layer contains any one or a combination of at least two of the compounds represented by formula (1).

13. The organic electroluminescent device according to claim 12, characterized in that: The electron blocking material in the electron blocking layer has the same chemical structure as any one of the P-type materials in the light-emitting layer.

14. The organic electroluminescent device according to claim 12, characterized in that: The organic functional layer further includes any one of a hole injection layer, a hole transport layer, a hole blocking layer, an electron transport layer or an electron injection layer, or a combination of at least two of them.

15. The organic electroluminescent device according to claim 12, characterized in that: The organic functional layer further includes a combination of a hole injection layer, a hole transport layer, an electron transport layer and an electron injection layer.

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