Organic light-emitting device

Abstract

The present invention relates to an organic electroluminescent device and an electronic device using the same, in which at least one organic functional layer of the organic electroluminescent device comprises a phosphineheptane compound of the following formula (I), # imgabs0 # phosphineheptane compound of formula (I), and can be applied to an organic functional layer of an OLED device, particularly applied to an electron transport layer and / or a charge generation layer; a unique seven-membered ring three-dimensional structure of the phosphineheptyl ring compound shown in the formula (I) is mixed with metal for use, stronger interaction can be generated, a core seven-membered ring of the phosphineheptyl ring compound and three specific aromatic systems form a more stable molecular conjugated system, the working voltage of a device can be remarkably reduced, the current efficiency is improved, and meanwhile the service life of the device is prolonged.

Description

Technical Field

[0001] The invention relates to an organic electroluminescent device and an electronic device using the organic electroluminescent device; the invention belongs to the technical field of organic electroluminescent materials. Background Art

[0002] Electroluminescence (EL) refers to the phenomenon that a luminescent material emits light under the action of an electric field and is stimulated by current and electric field. It is a luminescence process that directly converts electrical energy into light energy.

[0003] Organic Light-Emitting Diode (OLED) devices have attracted much attention due to their thinness, ability to emit light at high brightness at low driving voltage, and ability to emit light in multiple colors by selecting light-emitting materials. Since CW Tang et al. of Kodak revealed that organic thin-film elements can emit light at high brightness, a large number of OLED industry researchers have done a lot of research and promotion on their applications.

[0004] Generally, an OLED device is mainly composed of three parts: an anode, a cathode, and an organic layer between the anode and the cathode.

[0005] Functionalized organic materials commonly used in OLED devices include hole injection materials, hole transport materials, hole blocking materials, electron injection materials, electron transport materials, electron blocking materials, as well as luminescent host materials and luminescent guests (dyes).

[0006] For example, a typical organic electroluminescent device structure includes: anode / hole injection layer (HIL) / hole transport layer (HTL) / light-emitting layer (EML, light-emitting host material: light-emitting guest material) / electron transport layer (ETL) / cathode. They are stacked in sequence on the substrate, and the HIL, HTL, EML and ETL are thin films formed of organic compounds. The basic working principle of OLED devices: when voltage is applied to the anode and the cathode, the holes injected from the anode move to the EML via the HTL, and the electrons injected from the cathode move to the EML via the ETL. The holes and electrons recombine in the EML to generate excitons. When the excitons drop from the excited state to the ground state, light is emitted. Embedding a hole transport layer between the anode and the light-emitting layer and an electron transport layer between the cathode and the light-emitting layer can not only reduce the injection barrier of carriers and balance the carrier transfer rate, but also confine the excitons in the light-emitting layer, thereby improving the luminous efficiency of the device.

[0007] At present, technicians in this field continue to develop and improve the above-mentioned functionalized organic materials, with the aim of: while improving the brightness / illuminance of OLED devices, reducing the operating voltage as much as possible, and balancing the injection and flow of holes and electrons, so that the OLED with the above-mentioned structure has excellent efficiency and / or long life.

[0008] In the devices disclosed in the prior art, nitrogen-containing heterocyclic materials such as pyridine, pyrimidine, oxadiazole, triazole, imidazole, etc., which contain electron-withdrawing groups in their structures, are usually used as electron transport materials. However, the electron mobility of such materials is low, while the hole mobility is relatively high, which causes an electron-hole imbalance inside the light-emitting device, thereby leading to problems such as reduced device efficiency, poor stability, and short life.

[0009] Therefore, those skilled in the art hope to improve the performance of organic semiconductor layers, organic semiconductor materials and organic electroluminescent devices thereof, in particular to achieve higher efficiency and / or longer life by improving the properties of the organic compounds contained therein, in particular to reduce the operating voltage and / or improve the efficiency and life. Summary of the invention

[0010] In order to solve the above technical problems, the first aspect of the present invention provides an organic electroluminescent device, comprising:

[0011] a first electrode;

[0012] a second electrode;

[0013] at least one organic functional layer, located between the first electrode and the second electrode, and comprising at least a light-emitting layer;

[0014] At least one of the organic functional layers comprises a phosphoheptyl ring compound of formula (I),

[0015]

[0016] In the formula (I), Ar1 is selected from substituted or unsubstituted C6-C30 aryl or substituted or unsubstituted C3-C30 heteroaryl;

[0017] R1 and R2 are each independently selected from hydrogen, deuterium, a substituted or unsubstituted C1-C20 straight or branched alkyl or cycloalkyl group, a substituted or unsubstituted C6-C60 aryl group, a substituted or unsubstituted C3-C60 heteroaryl group, or any two adjacent R1 or any two adjacent R2 are bonded to form a ring;

[0018] n1 is selected from any integer from 0 to 6; n2 is selected from any integer from 0 to 6;

[0019] Alternatively, any number of hydrogens at any position in formula (I) are replaced by deuterium.

[0020] A second aspect of the present invention provides an electronic device, wherein the electronic device comprises the aforementioned organic electroluminescent device.

[0021] The organic electroluminescent device provided by the present invention comprises at least one organic functional layer comprising the phosphoheptyl ring compound of the structural formula (I). On the one hand, compared with conventional five-membered heterocyclic compounds and un-annulated compounds, the phosphoheptyl ring compound of the structural formula (I) has a unique seven-membered ring stereostructure, which can produce stronger interaction when used in combination with metals. On the other hand, the phosphoheptyl ring compound of the structural formula (I) has a core seven-membered ring and three specific aromatic systems (Ar1 and two naphthyl groups) to form a more stable molecular conjugated system, which can significantly reduce the operating voltage of the device, improve the current efficiency, and improve the device life. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The following drawings describe in detail the exemplary embodiments disclosed in this application. The same reference numerals represent similar structures in several views of the drawings. Those skilled in the art will understand that these embodiments are non-limiting, exemplary embodiments, and the drawings are only used for the purpose of illustration and description, and are not intended to limit the scope of this application. Other embodiments may also accomplish the inventive intent in this application. It should be understood that the drawings are not drawn to scale. Among them:

[0023] Figure 1 It is a schematic structural diagram of a single-layer organic electroluminescent device according to an embodiment of the present application.

[0024] Figure 2 It is a schematic diagram of the structure of a stacked organic electroluminescent device according to one embodiment of the present application. DETAILED DESCRIPTION

[0025] Unless otherwise specified, the following words, phrases and symbols used in this specification generally have the meanings described below.

[0026] In general, the nomenclature used herein (e.g., IUPAC nomenclature) and the laboratory procedures described below (including for organic chemistry, analytical chemistry, etc.) are those well known and commonly used in the art. Unless otherwise defined, all scientific and technical terms used herein in conjunction with the present disclosure described herein have the same meanings as commonly understood by those skilled in the art. In addition, in the claims and / or the specification, when the term "one" or "an" is used in conjunction with the term "comprising" or a noun, its meaning may be "one", but it is also consistent with the meaning of "one or more", "at least one" and "one or more than one". Similarly, the term "another" or "other" can mean at least a second or more.

[0027] It should be understood that whenever various aspects are described herein with the terms "including" or "comprising," other similar aspects described by "consisting of" and / or "consisting essentially of" are also provided.

[0028] As used herein, the term "phosphahene compound" refers to an organic compound having a six-membered ring structure containing a phosphorus atom.

[0029] In this article, the term "chiral compound" refers to a compound with structural asymmetry; a chiral compound cannot overlap with its mirror image, thus showing unique optical activity; generally, a chiral compound has optical rotation and has a deflection effect on plane polarized light. The P atom in the "phosphine heterohexyl ring compound" of this application is a chiral center.

[0030] As used herein, the term "substituted or unsubstituted" refers to a hydrogen atom in a functional group being replaced by another atom or functional group (i.e., a substituent), for example, by one or more of the following substituents: deuterium, a halogen group, a nitrile group, a nitro group, a hydroxyl group, a carbonyl group, an ester group, an imide group, an amino group, a phosphine oxide group, an alkoxy group, an alkylthio group, an aryloxy group, an arylthio group, an alkylsulfonyl group, an arylsulfonyl group, a silyl group, a boron group, a linear or branched alkyl group, a cycloalkyl group, an alkenyl group, an aryl group, an aralkyl group, an aralkenyl group, an alkylaryl group, an alkylamine group, an aralkylamine group, a heteroarylamine group, an arylamine group, an arylphosphino group, a heterocyclic group; or by a combination of two or more of the substituents listed above, for example, diphenyl and terphenyl.

[0031] Herein, the "straight or branched alkyl" is preferably a "straight or branched alkyl having 1 to 10 carbon atoms", wherein the number of carbon atoms is preferably 1 to 8, the number of carbon atoms is further preferably 1 to 6, and more preferably 1 to 4. In some embodiments, the alkyl group may include, but is not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, and the like.

[0032] Herein, the "cycloalkyl" is preferably a "cycloalkyl having 3 to 10 carbon atoms", more preferably a mono- or polycyclic hydrocarbon having 3 to 10 ring skeleton carbon atoms, wherein the number of carbon atoms is preferably 3 to 9, the number of carbon atoms is preferably 3 to 8, and more preferably 3 to 7. In some embodiments, the cycloalkyl may include, but is not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclohexylmethyl, and the like.

[0033] In this article, the term "alkoxy" refers to -O (alkyl). Optionally, the alkyl portion of the alkoxy group may contain 1-10 carbon atoms, 1-6 carbon atoms, or 1-4 carbon atoms, etc. In some embodiments, the alkoxy group may include, but is not limited to, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy, sec-butoxy, etc.

[0034] In this article, the term "aryl", preferably a substituted or unsubstituted (sub)aryl having 6 to 30 carbon atoms, refers to a monocyclic or condensed ring group derived from an aromatic hydrocarbon having 6 to 30 ring skeleton carbon atoms, wherein the number of ring skeleton carbon atoms is preferably 6 to 25, 6 to 20, 6 to 15, 6 to 12, and more preferably 6 to 10. In some embodiments, monocyclic (sub)aryl includes but is not limited to phenyl, biphenyl, terphenyl, quaterphenyl, pentaphenyl, etc. In some embodiments, condensed ring (sub)aryl includes but is not limited to naphthyl, anthracenyl, phenanthrenyl, pyrenyl, peryl, fluorenyl, etc. In some embodiments, condensed ring (sub)aryl can be substituted, such as substituted fluorenyl, optionally, methylfluorenyl, dimethylfluorenyl (optionally, 9,9-dimethylfluorenyl), phenylfluorenyl, diphenylfluorenyl (optionally, 9,9-diphenylfluorenyl), benzofluorenyl. In other embodiments, the fused ring (lene)aryl group may also contain a spiro structure; for example, 9,9'-spirobifluorenyl.

[0035] The above description of the aryl group can be applied to the aryl groups in the aryloxy group, aryloxythio group, aryloxysulfonyl group, arylphosphino group, arylalkyl group, arylalkylamino group, arylalkenyl group, alkylaryl group, arylamino group and the like.

[0036] In this article, the term "heteroaryl", preferably a substituted or unsubstituted (sub) heteroaryl having 5 to 30 carbon atoms, is an aryl having a ring skeleton atom, wherein the ring skeleton atom includes at least one heteroatom selected from the group consisting of B, N, O, S, Si, P, Se and Ge, preferably at least one heteroatom selected from N, O and S, wherein the number of ring skeleton carbon atoms is preferably 5 to 30, 5 to 25, 5 to 20, 5 to 15, 5 to 12, 5 to 10. The number of heteroatoms in the heteroaryl is preferably 1 to 4. The above heteroaryl can be a monocyclic ring or a condensed ring condensed with at least one benzene ring. In addition, herein, the above heteroaryl can be a heteroaryl formed by connecting at least one heteroaryl or aryl to a heteroaryl via one or more single bonds. In some embodiments, monocyclic heteroaryl includes but is not limited to furanyl, thienyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, oxazolyl, azinyl, oxazolyl, pyridinyl, pyrazinyl, pyrimidinyl, pyridazinyl, etc. In other embodiments, the fused ring heteroaryl groups include but are not limited to benzofuranyl, benzothienyl, dibenzofuranyl, dibenzothienyl, dinaphthofuranyl, naphthiobenzofuranyl, dinaphthothiophenyl, naphthiobenzothienyl, naphthrydinyl, acridinyl, xanthenyl, phenanthridinyl, naphthyrazinyl, triazaindenyl, indolyl, indolizinyl, phthalazinyl, benzocarbazolyl, benzothiazolyl, benzoxazolyl, benzimidazolyl, benzocarbazolyl, benzopyrazinyl, pyrimidoindolyl, pyrazinoindolyl, imidazopyridinyl, spirofluoreneoxanthryl, spirofluoreneazaanthryl and the like.

[0037] The above description of the heteroaryl group applies to the heteroaryl group in the heteroarylamine group and the arylheteroarylamine group.

[0038] In the present specification, the expression "bonds to adjacent atoms to form a ring" means a case where adjacent atoms can bond to each other to form a ring.

[0039] On one hand, the present application provides an organic electroluminescent device, comprising:

[0040] a first electrode;

[0041] a second electrode;

[0042] at least one organic functional layer, located between the first electrode and the second electrode, and comprising at least a light-emitting layer;

[0043] At least one of the organic functional layers comprises a phosphoheptyl ring compound of formula (I),

[0044]

[0045] In the formula (I), Ar1 is selected from substituted or unsubstituted C6-C30 aryl or substituted or unsubstituted C3-C30 heteroaryl;

[0046] R1 and R2 are each independently selected from hydrogen, deuterium, a substituted or unsubstituted C1-C20 straight or branched alkyl or cycloalkyl group, a substituted or unsubstituted C6-C60 aryl group, a substituted or unsubstituted C3-C60 heteroaryl group, or any two adjacent R1 or any two adjacent R2 are bonded to form a ring;

[0047] n1 is selected from any integer from 0 to 6; n2 is selected from any integer from 0 to 6;

[0048] Alternatively, any number of hydrogens at any position in formula (I) are replaced by deuterium.

[0049] In one or more embodiments, the phosphoheptyl ring compound is one or a combination of chiral compounds having the following structural formula (I') or (I"):

[0050]

[0051] In the formula (I') and (I"), Ar1 is selected from a substituted or unsubstituted C6-C30 aryl group or a substituted or unsubstituted C3-C30 heteroaryl group;

[0052] R1 and R2 are each independently selected from hydrogen, deuterium, a substituted or unsubstituted C1-C20 straight or branched alkyl or cycloalkyl group, a substituted or unsubstituted C6-C60 aryl group, a substituted or unsubstituted C3-C60 heteroaryl group, or any two adjacent R1 or any two adjacent R2 are bonded to form a ring;

[0053] n1 is selected from any integer from 0 to 6; n2 is selected from any integer from 0 to 6;

[0054] Alternatively, any number of hydrogens at any position in formula (I) are replaced by deuterium.

[0055] The phosphoheptyl ring compound of the present application is a chiral compound having structural asymmetry, for example, with the p atom as the chiral center. The phosphoheptyl ring compound of the present application may be of the structure of formula (I'), or of the structure of formula (I"), or of a combination of the structures of formula (I') or (I"), but the chiral structure of the phosphoheptyl ring compound of the present application is not limited thereto, for example, it may have other chiral centers in addition to the p atom or may contain multiple chiral centers. The phosphoheptyl ring compound of the present application includes a mixture of different diastereomers or corresponding racemates and a single separated diastereomer or enantiomer. The phosphoheptyl ring compound of the present application is used to prepare an organic electroluminescent device (OLED). The light efficiency of the OLED can be effectively improved by the unique spatial arrangement of the chiral compound, thereby laying a foundation for subsequent research and application of OLED.

[0056] In one or more embodiments, the organic electroluminescent device is a stacked device comprising two or more light-emitting layers, wherein the charge generation layer contains the phosphoheptyl ring compound.

[0057] In some embodiments, Ar1 is selected from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms and a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms. The substituted or unsubstituted aryl group having 6 to 30 carbon atoms may optionally have 6 to 28, 8 to 25, 10 to 22, 12 to 20 or 14 to 18 carbon atoms. The substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms may optionally have 3 to 28, 5 to 25, 6 to 22, 8 to 20, 12 to 18 or 14 to 16 carbon atoms.

[0058] Preferably, Ar1 is selected from one or a combination of substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthryl, substituted or unsubstituted anthracenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted triphenylene, substituted or unsubstituted pyrene, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophenyl.

[0059] In some embodiments, the number n1 of R1 is 0, 1, 2, 3, 4, 5 or 6; preferably, n1 is 0 or 1 or 2.

[0060] In some embodiments, the number n2 of R2 is 0, 1, 2, 3, 4, 5 or 6; preferably, n2 is 0 or 1 or 2.

[0061] In some embodiments, R1 and R2 are independently selected from hydrogen, deuterium, methyl, deuterated methyl, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted biphenyl, substituted or unsubstituted furanyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted thienyl, substituted or unsubstituted dibenzothienyl, substituted or unsubstituted pyridyl, substituted or unsubstituted pyrrolyl, substituted or unsubstituted indolyl, substituted or unsubstituted pyrimidinyl, substituted or unsubstituted quinolyl, substituted or unsubstituted isoquinolyl; or any two adjacent R1 or any two adjacent R2 are bonded to each other to form a ring.

[0062] In some embodiments, the substituent in the "substituted" is selected from hydrogen, deuterium, substituted or unsubstituted C1-C10 straight or branched alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C1-C10 alkoxy, substituted or unsubstituted C6-C20 aryl, substituted or unsubstituted C3-C20 heteroaryl.

[0063] Preferably, the substituent in the "substituted" is selected from deuterium, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclohexylmethyl, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy, sec-butoxy, phenyl, methylphenyl, tert-butylphenyl, naphthyl, biphenyl, pyridine and the like.

[0064] In some embodiments, the phosphine heteroheptyl ring compound is selected from any of the following structural formulas:

[0065]

[0066]

[0067]

[0068]

[0069]

[0070]

[0071] In the formulas (E-1) to (E-256), R3 and R4 are independently selected from deuterium, methyl, phenyl, naphthyl, biphenyl, dibenzofuranyl, and dibenzothiophenyl;

[0072] n3 and n4 are each selected from any integer from 0 to 3;

[0073] Alternatively, any number of hydrogen atoms at any positions in formulas (E-1) to (E-256) are substituted with deuterium.

[0074] In some embodiments, the phosphine heteroheptyl ring compound is selected from any of the following structural formulas:

[0075]

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083] In some preferred embodiments, the phosphine heteroheptyl ring compound is selected from any of the following structural formulas:

[0084]

[0085]

[0086]

[0087] In some preferred embodiments, the organic layer further comprises at least one n-type dopant;

[0088] Preferably, the n-type dopant is selected from metals or metal compounds; the metal is selected from alkali metals, alkaline earth metals, and rare earth metals; the metal compound is selected from alkali metal compounds, alkaline earth metal compounds, and rare earth metal compounds;

[0089] More preferably, the n-type dopant is selected from any one of the following metals or combinations: Li, Na, K, Be, Mg, Ca, Sr, Ba, Sc, Y, La, Sm, Eu, Tb, Yb, Lu, Ti, V, and Mn.

[0090] In some preferred embodiments, the organic functional layer includes an electron transport layer, an electron injection layer, or a charge generation layer; the electron transport layer is a single-layer electron transport layer or a multi-layer electron transport layer.

[0091] More preferably, the organic electroluminescent device is a single-layer device, wherein the electron transport layer contains the phosphoheptyl ring compound, or the organic electroluminescent device is a stacked device, wherein the stacked device comprises two or more light-emitting layers, wherein the electron transport layer and / or the charge generation layer contains the phosphoheptyl ring compound.

[0092] More preferably, the organic electroluminescent device is a stacked device, which comprises two or more light-emitting layers, wherein the charge generating layer contains the phosphoheptyl ring compound.

[0093] In some embodiments, the organic electroluminescent device comprises a first electrode and a second electrode arranged opposite to each other and an organic layer located between the first electrode and the second electrode, wherein the organic layer comprises a light-emitting layer. As an example, the first electrode is an anode and the second electrode is a cathode. The cathode may be one or more layers. The organic layer may be a single-layer structure or a multilayer series structure in which two or more organic layers are laminated. The organic layer may include at least one of a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer.

[0094] In some specific embodiments, the structure of the organic electroluminescent device can be selected from one of the following:

[0095] (1) An organic electroluminescent device comprises an anode, a hole injection layer, a first hole transport layer, a light-emitting layer, a first electron transport layer, and a cathode stacked in sequence, that is, anode / hole injection layer / first hole transport layer / light-emitting layer / first electron transport layer / cathode. The device structure will be expressed in this simplified manner below.

[0096] (2) anode / hole injection layer / first hole transport layer / second hole transport layer / light-emitting layer / first electron transport layer / cathode.

[0097] (3) anode / hole injection layer / first hole transport layer / second hole transport layer / light-emitting layer / first electron transport layer / second electron transport layer / cathode.

[0098] (4) anode / hole injection layer / first hole transport layer / second hole transport layer / light-emitting layer / first electron transport layer / second electron transport layer / electron injection layer / cathode.

[0099] (5) Anode / hole injection layer / first hole transport layer / second hole transport layer / light-emitting layer / first electron transport layer / second electron transport layer / multilayer cathode.

[0100] (6) anode / hole injection layer / first hole transport layer / first light-emitting layer / charge generation layer / first hole transport layer / second light-emitting layer / first electron transport layer / cathode.

[0101] (7) anode / hole injection layer / first hole transport layer / first light-emitting layer / charge generation layer / first hole transport layer / second light-emitting layer / first electron transport layer / second electron transport layer / cathode.

[0102] (8) anode / hole injection layer / first hole transport layer / second hole transport layer / first light-emitting layer / charge generation layer / first hole transport layer / second light-emitting layer / first electron transport layer / cathode.

[0103] (9) anode / hole injection layer / first hole transport layer / second hole transport layer / first light-emitting layer / charge generation layer / first hole transport layer / second light-emitting layer / first electron transport layer / second electron transport layer / cathode.

[0104] (10) Anode / hole injection layer / hole transport layer / electron blocking layer / light-emitting layer / electron transport layer / electron injection layer / cathode.

[0105] (11) anode / hole injection layer / first hole transport layer / second hole transport layer / light-emitting layer / hole blocking layer / electron transport layer / cathode.

[0106] (12) anode / hole injection layer / first hole transport layer / second hole transport layer / light-emitting layer / hole blocking layer / electron transport layer / electron injection layer / cathode.

[0107] (13) Anode / hole injection layer / hole transport layer / electron blocking layer / light-emitting layer / electron transport layer / cathode.

[0108] (14) Anode / hole injection layer / hole transport layer / electron blocking layer / light-emitting layer / hole blocking layer / electron transport layer / cathode.

[0109] (15) anode / hole injection layer / first hole transport layer / second hole transport layer / first light-emitting layer / hole blocking layer / electron transport layer / charge generation layer / first hole transport layer / second hole transport layer / second light-emitting layer / hole blocking layer / electron transport layer / cathode.

[0110] (16) anode / hole injection layer / first hole transport layer / second hole transport layer / first light-emitting layer / hole blocking layer / electron transport layer / charge generation layer / first hole transport layer / second hole transport layer / second light-emitting layer / hole blocking layer / electron transport layer / electron injection layer / cathode.

[0111] The light emission direction of the organic electroluminescent device can be emitted from the anode side or the cathode side. When emitted from the cathode side, the difference from the above structure is that a covering layer needs to be added on the cathode side.

[0112] The specific structure is as follows:

[0113] 1) Anode / hole injection layer / first hole transport layer / light-emitting layer / first electron transport layer / cathode / covering layer.

[0114] 2) Anode / hole injection layer / first hole transport layer / second hole transport layer / light-emitting layer / first electron transport layer / cathode / covering layer.

[0115] 3) anode / hole injection layer / first hole transport layer / second hole transport layer / light-emitting layer / first electron transport layer / second electron transport layer / cathode / covering layer.

[0116] 4) anode / hole injection layer / first hole transport layer / second hole transport layer / light-emitting layer / first electron transport layer / second electron transport layer / electron injection layer / cathode / covering layer.

[0117] 5) anode / hole injection layer / first hole transport layer / second hole transport layer / light-emitting layer / first electron transport layer / second electron transport layer / multilayer cathode / covering layer.

[0118] 6) anode / hole injection layer / first hole transport layer / first light-emitting layer / charge generation layer / first hole transport layer / second light-emitting layer / first electron transport layer / cathode / covering layer.

[0119] 7) Anode / hole injection layer / first hole transport layer / first light-emitting layer / charge generation layer / first hole transport layer / second light-emitting layer / first electron transport layer / second electron transport layer / cathode / covering layer.

[0120] 8) anode / hole injection layer / first hole transport layer / second hole transport layer / first light-emitting layer / charge generation layer / first hole transport layer / second light-emitting layer / first electron transport layer / cathode / covering layer.

[0121] 9) anode / hole injection layer / first hole transport layer / second hole transport layer / first light-emitting layer / charge generation layer / first hole transport layer / second light-emitting layer / first electron transport layer / second electron transport layer / cathode / covering layer.

[0122] 10) Anode / hole injection layer / hole transport layer / electron blocking layer / light-emitting layer / electron transport layer / electron injection layer / cathode / covering layer.

[0123] 11) Anode / hole injection layer / first hole transport layer / second hole transport layer / light-emitting layer / hole blocking layer / electron transport layer / cathode / covering layer.

[0124] 12) Anode / hole injection layer / hole transport layer / electron blocking layer / light-emitting layer / electron transport layer / cathode / covering layer.

[0125] 13) Anode / hole injection layer / hole transport layer / electron blocking layer / light-emitting layer / hole blocking layer / electron transport layer / cathode / covering layer.

[0126] Some specific functional layers in the organic electroluminescent device will be described below.

[0127] Substrate:

[0128] The substrate is generally located below the anode, and the substrate may be made of plastic or glass, and may be rigid or bendable. The substrate is provided with a driving unit, which may drive the corresponding pixel to emit light.

[0129] anode:

[0130] Organic EL (Organic Electro-Luminescence) components usually have requirements for the anode to have good conductivity, a flat surface, and not prone to cracks. At the same time, there are certain requirements for the work function, mainly to be able to match the hole injection layer and exert the hole injection effect.

[0131] When the top emission mode (light emitting from the cathode side) is adopted, the anode adopts a metal compound with a work function of 4.2eV or more, such as indium tin oxide alloy, tin oxide, indium zinc oxide, gold, silver, platinum, copper, carbon nanotubes, carbon nanowires, graphene, etc. The thickness is 10nm to 200nm, preferably 10nm to 50nm. A reflective electrode is set under the anode (close to the substrate end). The reflective electrode is generally made of metal or metal alloy, such as silver metal, copper metal, aluminum metal, gold metal or alloys of these metals and other metals. The reflectivity of the reflective electrode is relatively high, and the reflectivity is required to be above 90%. The thickness is usually used at a thickness of 100nm to 500nm, preferably in the range of 80nm to 150nm.

[0132] When the bottom emission mode (light emitting from the negative substrate side) is adopted, the anode adopts a metal compound with a work function of 4.2eV or more, for example, indium tin oxide alloy, tin oxide, indium zinc oxide, gold, silver, platinum, copper, carbon nanotubes, carbon nanowires, graphene, etc. The thickness is 10nm to 1μm, preferably 50nm to 200nm.

[0133] The anode can be produced by forming an electrode material into a thin film by a method such as vapor deposition, sputtering, or coating.

[0134] Hole injection layer:

[0135] In order to make the light-emitting device more efficient, the hole injection layer needs to have good hole injection ability. The hole injection layer uses a mixed material of a hole dopant and a hole transport host material.

[0136] The thickness of the hole injection layer can be

[0137] The mass ratio of the hole dopant to the hole transport host is 1% to 5%.

[0138] The hole dopant can be selected from organic compounds or metal oxides, such as annulene. for example:

[0139]

[0140] In the above formula (a), R1 to R 15 , R1 to R2 in the above chemical formula (b) are independently selected from fluorine, trifluoromethyl, cyano and nitro.

[0141] Specifically, it can be selected from the following compounds:

[0142]

[0143] The hole transport host material can be selected from monoamine and diamine compounds, selected from the following:

[0144]

[0145]

[0146] In the above formulas (c) to (f),

[0147] L1 to L3 are each independently selected from a single bond or a phenylene group;

[0148] Ar1 to A4 are each independently selected from substituted or unsubstituted aryl or heteroaryl groups having 6 to 30 carbon atoms, and the substituent is an alkyl group having 1 to 10 carbon atoms; preferably selected from phenyl, biphenyl, dimethylfluorenyl, dibenzofuranyl, dibenzothiophenyl, N-phenylcarbazolyl, benzo[B]naphtho[2,3-D]furan, benzo[B]naphtho[1,2-D]furan, and benzo[B]naphtho[2,1-D]furan.

[0149] In some preferred embodiments, the hole transport host material is selected from the group consisting of:

[0150]

[0151] Hole transport layer:

[0152] The hole transport layer may include one or more hole transport materials, and the hole transport layer material may be a single-layer structure or a multi-layer structure.

[0153] First hole transport layer:

[0154] The thickness of the first hole transport layer can be 3nm to 500nm. When there is no second hole transport layer, the thickness of the first hole transport layer is generally 40nm to 150nm; when there is a second hole transport layer, the thickness of the first hole transport layer is generally 3nm to 500nm. The material selection of the first hole transport layer can refer to the hole transport host material.

[0155] Second hole transport layer:

[0156] The thickness of the second hole transport layer is generally 5nm to 150nm. Aromatic amine compounds are often used, which can be aromatic monoamines or aromatic polyamines. The hole transport material is required to have high hole mobility, be able to reduce the driving voltage, and have a glass transition temperature exceeding 100°C to avoid crystallization at high temperatures.

[0157] Electron blocking layer:

[0158] The electron blocking layer can have both hole transport and electron blocking functions. At the same time, the higher triplet excitation energy level of the electron blocking layer can lock the excitons generated in the light-emitting layer in the light-emitting layer, thereby improving the luminous efficiency of the device.

[0159] Luminous layer:

[0160] The material of the light-emitting layer generally includes a host material and a guest dopant material. The content of the host material is greater than that of the guest dopant material. Optionally, the mass percentage of the guest dopant material in the light-emitting layer is 1% to 20%.

[0161] The guest doping material used as the luminescent material may include phosphorescent or fluorescent materials or thermally activated delayed fluorescent materials. Red light, green light and blue light can be selected from the above three guest doping materials. For example, the guest doping material of the luminescent layer corresponding to the luminescent unit with red luminescent color and the luminescent layer corresponding to the luminescent unit with green luminescent color is a phosphorescent material, and the guest doping material of the luminescent layer corresponding to the luminescent unit with blue luminescent color is a phosphorescent material.

[0162] Or for example, the guest doping material of the light-emitting layer corresponding to the light-emitting unit with red light-emitting color and the light-emitting layer corresponding to the light-emitting unit with green light-emitting color is a phosphorescent material, and the guest doping material of the light-emitting layer corresponding to the light-emitting unit with blue light-emitting color is a phosphorescent material.

[0163] Or for example, the guest doping material of the light-emitting layer corresponding to the light-emitting unit with red light-emitting color and the light-emitting layer corresponding to the light-emitting unit with green light-emitting color is a thermally activated delayed fluorescent material, and the guest doping material of the light-emitting layer corresponding to the light-emitting unit with blue light-emitting color is a fluorescent material.

[0164] Or for example, the guest doping material of the light-emitting layer corresponding to the light-emitting unit with red light-emitting color and the light-emitting layer corresponding to the light-emitting unit with green light-emitting color is a thermally activated delayed fluorescent material, and the guest doping material of the light-emitting layer corresponding to the light-emitting unit with blue light-emitting color is a phosphorescent material.

[0165] In order to reduce the power consumption of the organic light-emitting display panel in the organic electroluminescent device, the guest doping material can be selected to have excellent light-emitting performance. Taking the top-emitting device as an example, optionally, the light-emitting unit with a red light-emitting color has a light-emitting brightness of 1000 cd / m 2 The current efficiency is greater than 30cd / A, and the green luminous unit has a luminous brightness of 6000cd / m 2 The current efficiency is greater than 100cd / A, and the light-emitting unit with fluorescent blue light color has a light brightness of 1000cd / m 2 The current efficiency is greater than 5cd / A as the standard, and the appropriate guest doping material is selected. The light-emitting unit with a phosphorescent blue light color has a light-emitting brightness of 1000cd / m 2 The current efficiency is greater than 10cd / A. When the current efficiency is higher, the power consumption can be reduced.

[0166] As the light-emitting host material, one light-emitting host material or two light-emitting host materials may be selected.

[0167] Hole blocking layer:

[0168] In order to enhance the balance of hole and electron concentrations, a hole blocking layer is inserted to balance the carrier concentration and prevent exciton quenching. Generally, the hole blocking layer is located between the light-emitting layer and the electron transport layer. The hole blocking layer material must meet the conditions of strong stability, good film-forming properties, and a sufficiently high highest molecular occupied orbital.

[0169] Electron transport layer:

[0170] The electron transport material may include a mixture of an organic electron transport material and a metal compound, or a mixture of an organic electron transport material and a metal.

[0171] When the organic electron transport material is mixed with a metal compound material, for example, it is mixed with an alkali metal compound, an alkaline earth metal compound, a rare earth metal compound, and more specifically, it is mixed with a metal lithium compound, a metal calcium compound, a metal Mg compound, a metal samarium compound, a metal ytterbium compound, and more specifically, it is mixed with 8-hydroxyquinoline lithium, lithium fluoride, magnesium fluoride, ytterbium fluoride, calcium fluoride, etc. When mixed with a metal compound, the mass proportion of the organic electron transport material can be 20% to 80%, 20% to 40%, 40% to 60%, or 60% to 80%, etc.

[0172] When the organic electron transport material is mixed with a metal, for example, mixed with an alkali metal, an alkaline earth metal, or a rare earth metal, more specifically, mixed with lithium metal, magnesium metal, calcium metal, ytterbium metal, samarium metal, etc., when mixed with a metal, the mass proportion of the organic electron transport material can be 80% to 99%, 80% to 89%, 89% to 99%, 80% to 85%, 85% to 90%, 90% to 95%, or 95% to 99%, etc.

[0173] Electron injection layer:

[0174] The electron injection layer material may be selected from alkali metals, alkaline earth metals, rare earth metals, or inorganic substances or coordination compounds thereof.

[0175] Charge generation layer:

[0176] When a single-layer light-emitting layer device is used, holes and electrons are injected from the anode and cathode respectively, and a charge generation layer is not required. When a double-layer or multi-layer light-emitting layer is used, a charge generation layer is required between the light-emitting layers to achieve the effect of charge generation, injection and transmission. The charge generation layer is located between the two light-emitting layers, and is generally composed of two layers of P / N type materials, wherein the P-type material selects a hole injection material, and the N-type material uses an organic electron transport material doped with a metal for mixed use. The organic electron transport layer material is selected from the second electron transport layer mentioned above, and the metal is selected from alkali metals, alkaline earth metals, and rare earth metals, and more specifically lithium metal, magnesium metal, calcium metal, ytterbium metal, samarium metal, etc. When the organic electron transport material is mixed with the metal, the mass proportion of the organic electron transport material can be 80% to 99%, 80% to 89%, 89% to 99%, 80% to 85%, 85% to 90%, 90% to 95%, or 95% to 99%, etc.

[0177] cathode:

[0178] The cathode requires a material with good electrical conductivity and good surface flatness. In order to improve the electron injection capability, a material with a small work function is usually selected. The cathode material can be a single-layer cathode, or a double-layer or multi-layer cathode, generally a metal or a metal alloy. For a single-layer cathode, silver, copper, aluminum, gold, or alloys of these metals with other metals, such as alloys with rare earth metals, alkali metals, and alkaline earth metals, can be used, which can be listed as magnesium-indium alloy, magnesium-aluminum alloy, aluminum-potassium alloy, aluminum-scandium-potassium alloy, magnesium-silver alloy, silver-ytterbium alloy, silver-samarium alloy, etc. If the cathode uses a double-layer metal, the cathode near the light-emitting layer can use alkali metals, alkaline earth metals, rare earth metals, etc., such as lithium, calcium, magnesium, ytterbium, etc., to increase the electron injection ability, and the cathode layer far from the light-emitting side is mainly used to improve the conductivity. Generally, silver, copper, aluminum, gold or alloys of these metals with other metals, such as alloys with rare earth metals, alkali metals, and alkaline earth metals can be used, which can be listed as magnesium-indium alloy, magnesium-aluminum alloy, aluminum-potassium alloy, aluminum-scandium-potassium alloy, magnesium-silver alloy, silver-ytterbium alloy, silver-samarium alloy, etc. The cathode can also be formed into a thin film by evaporation, sputtering, etc.

[0179] When light comes out from the anode side, the cathode is required to be light-proof, and a cathode of not less than 100nm can be evaporated. When light comes out from the cathode side, the cathode is required to be transparent, and the transmittance should be greater than 40% at this time, and the thickness is 10nm to 20nm.

[0180] Cover:

[0181] When light comes out from the cathode side, the photons resonate with the electrons in the cathode metal to reduce the light output efficiency. Adding a covering layer on the side of the cathode away from the light-emitting layer can reduce this effect and effectively improve the light efficiency.

[0182] When adding a cover layer, directly use a cover material with a high refractive index and a low absorption coefficient. For example,

[0183] For example, the material has a refractive index greater than 1.9 at a wavelength of 460nm and an absorptivity less than 0.01%, more preferably a refractive index greater than 2.0 at a wavelength of 460nm and an absorptivity less than 0.01%, more preferably a refractive index greater than 2.1 at a wavelength of 460nm and an absorptivity less than 0.01%, and a refractive index greater than 2.2 at a wavelength of 460nm and an absorptivity less than 0.01%.

[0184] Some of the compounds listed in the overlay are as follows:

[0185]

[0186] On the other hand, the present application further provides an electronic device, which includes the above-mentioned organic electroluminescent device. Preferably, the electronic device is a display device or a lighting device.

[0187] Below will be combined with the embodiment of the present application, the technical scheme of the present application is clearly and completely described. Unless otherwise specified, the reagents and raw materials used can be purchased through commercial channels. The experimental methods of the following examples that do not specify specific conditions are usually measured according to national standards. If there is no corresponding national standard, then according to general international standards, conventional methods and conditions, or according to the conditions recommended by the manufacturer, or according to the product specification selection. Unless otherwise specified, all parts are weight parts, and all percentages are weight percentages.

[0188] Measurement instruments and methods

[0189]

Mass Spectrometry and Nuclear Magnetic Resonance

[0190] In the present application, the mass spectrum was measured by a Waters Corporation single quadrupole mass spectrometer, and the nuclear magnetic resonance was measured by a 400 MHz nuclear magnetic resonance instrument (manufactured by Bruker, Germany).

[0191]

Life measurement

[0192] The device life test involved in this application is obtained using a Foster life measurement system equipped with a power supply and a photodiode as a detection unit.

[0193]

Raw materials and reagents

[0194] The initial raw materials and solvents of this application were purchased from Shanghai Titan Technology Co., Ltd., some commonly used OLED intermediates and other products were purchased from domestic OLED intermediate manufacturers; various palladium catalysts, ligands, etc. were purchased from Shaanxi Ruike New Materials Co., Ltd. 1HNMR data were measured using a (400 MHz) nuclear magnetic resonance instrument (manufactured by Bruker, Germany); HPLC data were measured using a Waters Corporation UPLC ultra-high performance liquid chromatograph. LC-MS (liquid chromatography-mass spectrometry) was tested on a UPLC+SQD2 instrument from Waters Corporation.

[0195] Synthesis Example

[0196] Synthetic common operations:

[0197]

[0198] First step reaction: Synthesis of compound A3:

[0199] 1 molar equivalent of A1 and 1.1 molar equivalent of A2, add 1% molar equivalent of catalyst Pd2(dba)3 and 2% molar equivalent of S-phos (short for 2-dicyclohexylphosphine-2',6'-dimethoxy-1,1'-biphenyl), as well as 2 molar equivalents of K2CO3, 7-20 times the weight of A1 toluene, 1-3 times the weight of ethanol, 1-3 times the weight of water, the system is replaced with nitrogen 3 times, the reaction temperature is raised to reflux, and the reaction is stirred for 4-8 hours. The reaction liquid is cooled to room temperature, separated, and concentrated. Rapid silica gel column chromatography (hot toluene), the column liquid is concentrated, refluxed, and n-hexane is added dropwise during the cooling process. After complete cooling, it is stirred for 2-4 hours, and the solid is filtered and dried.

[0200] Second step reaction: Synthesis of compound A5:

[0201] Add 1 mol equivalent of compound A3 to a three-necked flask, fully replace with N2 3 times, then add 15-30 times the weight of A3 in anhydrous tetrahydrofuran, stir the solution at -78°C, then slowly drop 2.2 mol equivalent of 2.5M n-butyl lithium dissolved in n-hexane. After the dropwise addition, stir at -78°C for 2h, add 0.8 mol equivalent of compound A4, and continue to stir at -78°C for 2h.

[0202] The reaction solution was filtered through silica gel, and then rinsed with a mixed solvent of dichloromethane / n-hexane = 1:1. The filtrate was concentrated and recrystallized with toluene / n-hexane, and a solid was obtained by suction filtration.

[0203] Step 3: Synthesis of Compound A

[0204] A5 solid was dissolved in 20-50 times the weight of dichloromethane, and 1-10 times the weight of A5 hydrogen peroxide (H2O2) was added, and the mixture was reacted at room temperature for 4 hours. The organic phase was separated, dried, concentrated, slurried with n-hexane, and filtered to obtain a white solid.

[0205] Chiral compounds can be obtained by synthesizing chiral raw materials or by performing chiral physical separation on the obtained racemic compounds.

[0206] The product "Compound A" of the above synthetic route is any one of the structural formulas of the present application (I).

[0207] Synthesis Example 1

[0208] Synthesis of compound 1

[0209]

[0210] First step reaction: Synthesis of compound 1-3:

[0211] Compound 1-1 (20 g, 60 mmol) and compound 1-2 (16.5 g, 66 mmol) were added with catalyst Pd2(dba)3 (0.55 g, 0.6 mmol) and molar equivalent of S-phos (0.5 g, 1.2 mmol), as well as 2 molar equivalents of K2CO3 (16.5 g, 120 mmol)3, 200 mL of toluene, 40 mL of ethanol, 40 mL of water, and the system was replaced with nitrogen 3 times. The reaction temperature was raised to reflux and stirred for 6 h. The reaction solution was cooled to room temperature, separated and concentrated. Rapid silica gel column chromatography (hot toluene) was performed, the column liquid was concentrated, refluxed, and n-hexane was added dropwise during the cooling process. After complete cooling, it was stirred for 2 h, the solid was filtered, and dried to obtain 13.5 g, with a yield of 55%.

[0212] Second step reaction: Synthesis of compound 1-5:

[0213] Compound 1-2 (12 g, 29 mmol) was added to a three-necked flask, and the N2 was fully replaced for 3 times. Then 200 mL of anhydrous tetrahydrofuran was added, and the solution was stirred at -78°C, and then 2.5 M concentration of n-butyl lithium (25.5 mL, 63.8 mmol) dissolved in n-hexane was slowly added dropwise. After the addition, the mixture was stirred at -78°C for 2 h, and compound 1-4 (5.9 g, 23.2 mmol) was added, and the mixture was stirred at -78°C for 2 h.

[0214] The reaction solution was filtered through silica gel, and then rinsed with a mixed solvent of dichloromethane / n-hexane = 1:1. The filtrate was concentrated and recrystallized with 300 mL of toluene / n-hexane. 6 g of solid was obtained by suction filtration, with a yield of 47%.

[0215] Step 3: Synthesis of Compound 1

[0216] The intermediate compound 1-5 (5 g, 11.4 mmol) was dissolved in 200 mL of dichloromethane, and 20 mL of hydrogen peroxide was added, and the mixture was reacted at room temperature for 4 hours. The organic phase was separated, dried, concentrated, and slurried with n-hexane, and filtered to obtain 3.8 g of a white solid, with a yield of 73.3% and a total yield of 18.9% in three steps.

[0217] Product identification data: 1 H NMR(Chloroform-d)δ8.12(d,4H),7.89(m,4H),7.80(d,2H),7.64(m,6H),7.49–7.41(d,4H),7.41(m,1H).

[0218] Synthesis Example 2

[0219] Synthesis of compound 5

[0220]

[0221] The synthesis method of compound 5 is the same as that of compound 1, except that the raw material of the second step reaction is replaced by 5-4 from 1-4. The total yield of compound 5 is 21.5%.

[0222] Product identification data: 1 H NMR(Chloroform-d)δ8.80(d,1H),8.26(t,1H),8.08(t,4H),7.86(m,6H),7.80(d,2H),7.69(d,1H),7.55(m,3H),7.52(m,1H),7.44(t,2H).

[0223] Synthesis Example 3

[0224] Synthesis of compound 16

[0225]

[0226] First step reaction: Synthesis of 16-3:

[0227] 16-1 (30 g, 73.7 mmol) and 16-2 (20.3 g, 81 mmol), catalyst Pd2(dba)3 (0.67 g, 0.74 mmol) and molar equivalent of S-phos (0.6 g, 1.47 mmol), and 2 molar equivalents of K2CO3 (20.3 g, 147 mmol)3 were added, 400 mL of toluene, 60 mL of ethanol, 60 mL of water, and the system was replaced with nitrogen 3 times. The reaction temperature was raised to reflux and stirred for 6 h. The reaction solution was cooled to room temperature, separated, and concentrated. Rapid silica gel column chromatography (hot toluene), column liquid was concentrated, refluxed, and n-hexane was added dropwise during the cooling process. After complete cooling, it was stirred for 3 h, the solid was filtered, and dried to obtain 16.1 g of compound 16-3, with a yield of 45%.

[0228] Second step reaction: Synthesis of 16-5:

[0229] Compound 16-2 (15 g, 30 mmol) was added to a three-necked flask, and the N2 was fully replaced three times. Then 200 mL of anhydrous tetrahydrofuran was added, and the solution was stirred at -78°C, and then 2.5 M concentration of n-butyl lithium (27.2 mL, 67.9 mmol) dissolved in n-hexane was slowly added dropwise. After the addition, the mixture was stirred at -78°C for 2 h, and compound 16-4 (4.2 g, 24 mmol) was added, and the mixture was stirred at -78°C for 2 h.

[0230] The reaction solution was filtered through silica gel, and then rinsed with a mixed solvent of dichloromethane / n-hexane = 1:1. The filtrate was concentrated and recrystallized with 300 mL of toluene / n-hexane. 5.4 g of solid was obtained by suction filtration, with a yield of 42%.

[0231] Step 3: Synthesis of Compound 16

[0232] Intermediate 16-5 (5 g, 11.5 mmol) was dissolved in 200 mL of dichloromethane, and 20 mL of hydrogen peroxide was added, and the mixture was reacted at room temperature for 4 hours. The organic phase was separated, dried, concentrated, and slurried with n-hexane, and filtered to obtain 3.5 g of a white solid with a yield of 68% and a total yield of 12.8% in three steps.

[0233] Product identification data: 1 H NMR(Chloroform-d)δ8.05(m,3H),7.83(m,3H),7.66(m,6H),7.48(m,2H),7.39(m,3H),7.34(d,2H).

[0234] Synthesis Example 4

[0235] Synthesis of compound 20

[0236]

[0237] The method for synthesizing compound 20 is the same as that in Example 3, except that the raw material 16-1 in the first step reaction is replaced by 20-1, and the raw material 16-4 in the second step reaction is replaced by 20-4. The total yield of the three steps is 18%.

[0238] Product identification data: 1 H NMR (Chloroform-d) δ8.55(d,1H),8.39(d,1H),8.25(d,1H),8.19(d,1H),8.14(d,2H),7.94(m,7H),7.83(m,2H),7.36(m,6H).

[0239] Synthesis Example 5

[0240] Synthesis of compound 21

[0241]

[0242] The method for synthesizing compound 21 is the same as that of Example 3, except that the raw material 21-1 in the first step reaction is replaced by 16-1, and the total yield of the three steps is 16%.

[0243] Product identification data: 1 H NMR(Chloroform-d)δ8.03(m,4H),7.97(d,1H),7.90(d,1H),7.83(d,1H),7.72(m,2H),7.49(m,4H),7.37(m,4H),7.24(m,2H).

[0244] Synthesis Example 6

[0245] Synthesis of compound 34

[0246]

[0247] The method for synthesizing compound 34 is the same as that in Example 3, except that the raw material 16-1 in the first step reaction is replaced by 34-1, and 16-2 is replaced by 34-2. The total yield of the three steps is 14%.

[0248] Product identification data: 1 H NMR(Chloroform-d)δ9.74(d,1H),8.80(d,1H),8.51(m,2H),8.48(d,1H),8.29(d,1H),8.23(d,1H),8. 04(d,1H),7.93(d,1H),7.69(m,5H),7.60(d,1H),7.55(m,3H),7.51(m,2H),7.44(m,1H),7.32(m,9H).

[0249] Synthesis Example 7

[0250] Synthesis of compound 37

[0251]

[0252] The method for synthesizing compound 37 is the same as that in Example 3, except that the raw material 16-1 in the first step reaction is replaced by 37-1, and 16-2 is replaced by 37-2. The total yield of the three steps is 19%.

[0253] Product identification data: 1 H NMR(Chloroform-d)δ8.23(t,1H),8.03(t,1H),7.99(d,1H),7.91(m,2H),7.85(d,1H),7. 68(m,2H),7.53(m,5H),7.46(m,2H),7.32(m,8H),1.83(m,2H),1.71(m,2H),1.31(d,12H).

[0254] Synthesis Example 8

[0255] Synthesis of compound 48

[0256]

[0257] The method for synthesizing compound 48 is the same as that in Example 1, except that the raw material 1-1 in the first step reaction is replaced by 48-1, and the raw material in the second step reaction is replaced by 48-4. The total yield of the three steps is 23%.

[0258] Product identification data: 1 H NMR(Chloroform-d)δ8.05(m,3H),7.79(m,7H),7.56(t,1H),7.45(m,3H),7.39(m,2H),7.28(d,1H),3.40(s,4H).

[0259] The other compounds were obtained by similar synthesis methods.

[0260] The corresponding yields and LC MS: M / Z results are shown in Table 1 below.

[0261] Table 1

[0262]

[0263]

[0264]

[0265]

[0266]

[0267] Preparation of organic electroluminescent devices

[0268] OLED device structure

[0269] Figure 1 1 is a schematic cross-sectional view of an organic electroluminescent device (OLED) 100 according to an exemplary embodiment of the present invention. The OLED 100 includes a substrate 101, an anode 102, a hole injection layer 103, a first hole transport layer 104, a second hole transport layer 105, an organic light emitting layer 106, a hole blocking layer 107, an electron transport layer 108, and a cathode 109.

[0270] Figure 2 is a schematic cross-sectional view of a stacked organic electroluminescent device (OLED) according to an exemplary embodiment of the present invention, the stacked OLED including two organic light-emitting layers and a charge generation layer. Figure 2 , the OLED 200 includes an anode 210, a first light emitting unit 220a, a charge generating layer 230, a second light emitting unit 220b and a cathode 240;

[0271] The first light-emitting unit 220a includes: a hole injection layer 221a, a first hole transport layer 222a, a second hole transport layer 223a, and a first organic light-emitting layer 224a;

[0272] The charge generation layer 230 includes: an n-type charge generation layer 231 and a p-type charge generation layer 232;

[0273] The second light emitting unit 220b includes: a first hole transport layer 222b, a second hole transport layer 223b, a second organic light emitting layer 224b, a hole blocking layer 225b, an electron transport layer 226b, and an electron injection layer 227b.

[0274] Single-layer OLED device example 1 (device containing a phosphoheptyl ring compound as an electron transport layer)

[0275] refer to Figure 1 The method for preparing an organic electroluminescent device in this embodiment includes:

[0276] (1) On a glass substrate 101, a transparent anode ITO film layer (thickness 150 nm) is formed by a magnetron sputtering process to obtain a first electrode as the anode 102;

[0277] (2) By vacuum evaporation, a mixture of compound M1 and compound M2 is deposited on the surface of the anode 102 as the hole injection layer 103, with a mixing ratio of 97:3 (mass ratio) and a thickness of

[0278] (3) Then, compound M1 (thickness) is deposited on the surface of hole injection layer 103. ), to obtain a first hole transport layer 104;

[0279] (4) Compound M3 (thickness) was evaporated on the first hole transport layer 104. ), forming a second hole transport layer 105;

[0280] (5) On the surface of the second hole transport layer 105, compound M4 and compound M5 were co-evaporated at a mass ratio of 98:2 to form an organic light-emitting layer 106 (thickness );

[0281] (6) Compound M6 is evaporated on the organic light-emitting layer 106 to form a hole blocking layer 107 (thickness );

[0282] (7) A mixed material of the compound 1 of the present invention and metal Yb in a mass ratio of 97:3 was deposited on the hole blocking layer 107 to form an electron transport layer 108 (thickness );

[0283] (8) Magnesium (Mg) and silver (Ag) are mixed and deposited on the electron transport layer 108 at a deposition rate of 1:10 to form a layer with a thickness of The second electrode is used as cathode 109 to complete the preparation of the organic electroluminescent device.

[0284] The compounds involved in the above device preparation example are shown in Table 2 below:

[0285] Table 2

[0286]

[0287] Single-layer OLED device examples 2-8

[0288] The single-layer device embodiments 2 to 8 are prepared by the same method as the single-layer OLED device embodiment 1, except that when forming the electron transport layer, the electron transport layer material in embodiment 1 is replaced by the synthesis embodiment 2-8 respectively.

[0289] Single-layer OLED device comparative example 1-2

[0290] The organic electroluminescent device was prepared by the same method as in Example 1 of the blue light device, except that compounds C1 and C2 were used as electron transport layer materials to replace the electron transport layer materials in Example 1 when forming the electron transport layer.

[0291] The operating voltage and efficiency of the organic electroluminescent device prepared as above were calculated by a computer-controlled Keithley 2400 test system (the test current was 10 mA / cm 2 The device life under dark conditions was obtained using a Foster life measurement system equipped with a power supply and a photodiode as a detection unit (the normal temperature life test conditions were: ambient temperature 25°C, constant current 50 mA / cm 2 LT95 refers to the time required for the brightness to decrease from the initial brightness to 95%, the time of device embodiment 1 is taken as 100%, and the lifespans of other embodiments are relative values ​​compared thereto.

[0292] The test results are shown in Table 3 below.

[0293] Table 3

[0294] Device Embodiment Electron transport materials Relative driving voltage Relative current efficiency LT95(hours) Single-layer device comparative example 1 Compound C1 100％ 100％ 100％ Single-layer device comparative example 2 Compound C2 88％ 143％ 125％ Single-layer device embodiment 1 Compound 1 65％ 155％ 197％ Single-layer device embodiment 2 Compound 5 68％ 156％ 193％ Single-layer device embodiment 3 Compound 16 70％ 156％ 188％ Single-layer device embodiment 4 Compound 20 71％ 155％ 187％ Single-layer device embodiment 5 Compound 21 73％ 155％ 180％ Single-layer device embodiment 6 Compound 34 66％ 157％ 190％ Single-layer device embodiment 7 Compound 37 72％ 154％ 182％ Single-layer device embodiment 8 Compound 48 67％ 159％ 179％

[0295] Laminated OLED device Example 1 (device containing a phosphoheptyl ring compound as an n-type charge generation layer)

[0296] refer to Figure 2 , the method for preparing a stacked organic electroluminescent device comprises:

[0297] (1) forming a transparent anode ITO film layer (thickness 150 nm) on a glass substrate by magnetron sputtering to obtain a first electrode as an anode;

[0298] (2) By vacuum evaporation, a mixture of compound M1 and compound M2 is deposited on the surface of the anode 210 as a hole injection layer 221a, with a mixing ratio of 97:3 (mass ratio) and a thickness of

[0299] (3) Then, compound M1 (thickness) is deposited on the surface of hole injection layer 221a. ), to obtain a first hole transport layer 222a;

[0300] (4) Compound M3 (thickness) was evaporated on the first hole transport layer 222a. ), forming a second hole transport layer 223a;

[0301] (5) On the surface of the second hole transport layer 223a, compound M4, compound M5 and compound M6 were co-evaporated at a mass ratio of 45:45:10 to form a first organic light-emitting layer 224a (thickness );

[0302] (6) Compound M7 is evaporated on the first organic light-emitting layer 224a to form a hole blocking layer 225a (thickness );

[0303] (7) Compound C3 and LiQ with a mass ratio of 5:5 were evaporated on the hole blocking layer 225a to form an electron transport layer (ETL1) 226a (thickness );

[0304] (8) Then, a mixed material of compound 1 and metal Yb with a mass ratio of 97:3 was deposited on the electron transport layer 226a to form an n-type charge generation layer 231 (n-CGL, ); then evaporate the mixed material of compound M1 and compound M2 as the p-type charge generation layer 232 (p-CGL), the mixing ratio is 98:2 (mass ratio), the thickness is

[0305] (9) Then, the compound M1 is evaporated to form the first hole transport layer 222b (thickness );

[0306] (10) Compound M3 is evaporated on the first hole transport layer 222b to form a second hole transport layer 223b (thickness );

[0307] (11) Compound M4, compound M5 and compound M6 were co-evaporated at a mass ratio of 45:45:10 on the surface of the second hole transport layer 223b to form a second organic light-emitting layer 224b (thickness );

[0308] (12) Compound M7 is evaporated on the second organic light-emitting layer 224b to form a hole blocking layer 225b (thickness );

[0309] (13) Subsequently, a mixed material of compound C3 and LiQ (thickness: 5:5) was deposited on the hole blocking layer 225b. ) to form an electron transport layer (ETL2) 226b, and then evaporate metal Yb (thickness ) forming an electron injection layer 227b;

[0310] (14) Magnesium (Mg) and silver (Ag) are mixed and deposited on the electron injection layer 227b at a deposition rate of 1:10 to form The second electrode is used as cathode 240 to complete the preparation of the organic electroluminescent device.

[0311] The compounds involved in the above device preparation example are shown in Table 4 below:

[0312] Table 4

[0313]

[0314]

[0315] Laminated OLED Device Examples 2-8

[0316] The same method as that of stacked device example 1 was used to prepare stacked device examples 2-8, except that when forming the n-type charge generation layer (n-CGL), the compound 1 used in stacked device example 1 was replaced by synthesis examples 2-8 respectively.

[0317] Comparative Example 1-2 of Laminated OLED Device

[0318] The organic electroluminescent device was prepared in the same manner as in the stacked device example 1, except that the compounds C1 and C2 materials were used instead of the compound 1 used in the stacked device example 1 when forming the n-type charge generation layer (n-CGL).

[0319] The test results are shown in Table 5.

[0320] Table 5

[0321]

[0322]

[0323] From the technical solution point of view, the single-layer / stacked-layer device embodiments 1-8 are the same as their respective device control examples except for the electron transport layer and the n-type charge generation layer.

[0324] It can be seen from the results in Table 3 and Table 5 that, compared with the respective device control examples, the single-layer / stacked-layer device embodiments 1-8 have the characteristics of significantly lower driving voltage, significantly improved current efficiency, and longer service life.

[0325] The inventors of the present application believe that the reason behind this is due to the molecular structure of the phosphoheptyl ring compound of formula (I) of the present application; on the one hand, compared with conventional five-membered heterocyclic compounds and unannulated compounds, the phosphohexyl ring compound of formula (I) of the present application has a unique seven-membered ring stereostructure, which can interact more strongly with metals; on the other hand, the phosphohexyl ring compound of formula (I) of the present application, its core seven-membered ring and specific three aromatic systems (Ar1 and two naphthyl groups) form a more stable molecular conjugated system, which can significantly reduce the operating voltage of the device, improve the current efficiency, and improve the device life.

[0326] It should be understood that the series of detailed descriptions listed above are only specific descriptions of feasible implementation methods of the present invention, and are not intended to limit the protection scope of the present invention. Those skilled in the art should take the description as a whole, and the technical solutions in each implementation method can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art. All equivalent implementation methods or changes that do not deviate from the technical spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. An organic electroluminescent device, comprising: a first electrode; a second electrode; at least one organic functional layer, located between the first electrode and the second electrode, and comprising at least a light-emitting layer; At least one of the organic functional layers comprises a phosphoheptyl ring compound of formula (I), In the formula (I), Ar1 is selected from substituted or unsubstituted C6-C30 aryl or substituted or unsubstituted C3-C30 heteroaryl; R1 and R2 are each independently selected from hydrogen, deuterium, a substituted or unsubstituted C1-C20 straight or branched alkyl or cycloalkyl group, a substituted or unsubstituted C6-C60 aryl group, a substituted or unsubstituted C3-C60 heteroaryl group, or any two adjacent R1 or any two adjacent R2 are bonded to form a ring; n1 is selected from any integer from 0 to 6; n2 is selected from any integer from 0 to 6; Alternatively, any number of hydrogens at any position in formula (I) are replaced by deuterium.

2. The organic electroluminescent device according to claim 1, characterized in that: The organic electroluminescent device is a stacked device, which comprises two or more light-emitting layers, wherein the charge generating layer contains the phosphoheptyl ring compound.

3. The organic electroluminescent device according to claim 1 or 2, characterized in that: The Ar1 is selected from one or a combination of substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthryl, substituted or unsubstituted biphenyl, substituted or unsubstituted triphenylene, substituted or unsubstituted pyrene, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophenyl.

4. The organic electroluminescent device according to claim 1 or 2, characterized in that: R1 and R2 are independently selected from hydrogen, deuterium, methyl, deuterated methyl, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted biphenyl, substituted or unsubstituted furyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted thienyl, substituted or unsubstituted dibenzothienyl, substituted or unsubstituted pyridyl, substituted or unsubstituted pyrrolyl, substituted or unsubstituted indolyl, substituted or unsubstituted pyrimidinyl, substituted or unsubstituted quinolyl, substituted or unsubstituted isoquinolyl, or any two adjacent R1 or any two adjacent R2 are bonded to each other to form a ring.

5. The organic electroluminescent device according to any one of claims 1 to 4, characterized in that: The substituent in the "substituted" is selected from hydrogen, deuterium, substituted or unsubstituted C1-C10 straight or branched alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C1-C10 alkoxy, substituted or unsubstituted C6-C20 aryl, substituted or unsubstituted C3-C20 heteroaryl.

6. The organic electroluminescent device according to claim 1 or 2, characterized in that: The structural formula of the phosphine heteroheptyl ring compound is selected from any one of the following structural formulas: In the formulas (E-1) to (E-256), R3 and R4 are independently selected from deuterium, methyl, phenyl, naphthyl, biphenyl, dibenzofuranyl, and dibenzothiophenyl; n3 and n4 are each selected from any integer from 0 to 3; Alternatively, any number of hydrogen atoms at any positions in formulas (E-1) to (E-256) are substituted with deuterium.

7. The organic electroluminescent device according to claim 1 or 2, characterized in that: The structural formula of the phosphine heteroheptyl ring compound is selected from any one of the following structural formulas:

8. The organic electroluminescent device according to claim 1 or 2, characterized in that: The structural formula of the phosphine heteroheptyl ring compound is selected from any one of the following structural formulas:

9. The organic electroluminescent device according to claim 1 or 2, characterized in that: The organic functional layer further comprises at least one n-type dopant; Preferably, the n-type dopant is selected from metals or metal compounds; the metal is selected from alkali metals, alkaline earth metals, and rare earth metals; the metal compound is selected from alkali metal compounds, alkaline earth metal compounds, and rare earth metal compounds; More preferably, the n-type dopant is selected from any one of the following metals or combinations: Li, Na, K, Be, Mg, Ca, Sr, Ba, Sc, Y, La, Sm, Eu, Tb, Yb, Lu, Ti, V, Mn; Preferably, the content of the n-type dopant in the organic functional layer is in the range of 0.5 wt % to 25 wt %, preferably in the range of 1 to 20 wt %, more preferably in the range of 1 to 15 wt %, most preferably in the range of 1 to 10 wt %.

10. The organic electroluminescent device according to any one of claims 1 to 9, characterized in that: The organic functional layer includes an electron transport layer, an electron injection layer, or a charge generation layer; the electron transport layer is a single-layer electron transport layer or a multi-layer electron transport layer; More preferably, the organic electroluminescent device is a single-layer device, wherein the electron transport layer contains the phosphoheptyl ring compound.

11. An electronic device, characterized in that: The electronic device comprises the organic electroluminescent device as claimed in claim 10; preferably, the electronic device is a display or lighting device.

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