Laminated organic light-emitting device and display device comprising same

Abstract

The invention provides a laminated organic light-emitting device and a display device comprising the same, the laminated organic light-emitting device comprises an anode, a cathode and at least two light-emitting units arranged between the anode and the cathode, each light-emitting unit comprises a light-emitting layer and an electron blocking layer, a charge connection layer is arranged between any two adjacent light-emitting units, the charge connection layer comprises a P-type charge generation layer, and the P-type charge generation layer comprises a first host material and a first doping material. Through the material design of the P-type charge generation layer in the charge connection layer, the design of the carrier mobility and the energy level matching between materials, the carrier transport balance is realized, so that the laminated organic light-emitting device has higher light-emitting efficiency and light-emitting brightness, meanwhile, the voltage and the energy consumption are reduced, and the service lives of the device and the display device are prolonged.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic electroluminescent display, and in particular relates to a laminated organic electroluminescent device and a display device comprising the same. Background Art

[0002] An organic light-emitting device (OLED) consists of a cathode, an anode, and an organic thin-film structure located between the two electrodes. This thin-film structure contains a variety of organic functional materials and is the core of the OLED device. Common organic functional materials include hole injection materials, hole transport materials, hole blocking materials, electron injection materials, electron transport materials, electron blocking materials, luminescent host materials, and luminescent guest materials (dyes). When power is applied, electrons and holes from the two electrodes are injected and transported to the light-emitting region, where they recombine, generating excitons and emitting light.

[0003] With the development of display technology and people's demand for more advanced display technology, people have put forward higher requirements for the brightness, lifespan and other performance of display panels and OLED devices. In order to improve the performance of OLED devices, stacked organic electroluminescent devices containing two or more light-emitting units have come into being. Compared with single-layer devices containing one light-emitting unit, stacked devices have obvious performance advantages in terms of luminous brightness and lifespan. However, in stacked organic electroluminescent devices, the voltage drop caused by the charge generation layer between each light-emitting unit can lead to problems such as increased device voltage, increased power consumption, and reduced efficiency and lifespan. Therefore, the field urgently needs to develop stacked organic electroluminescent devices with higher performance. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a stacked organic electroluminescent device and a display device comprising the same. Through the material design and energy level matching of the P-type charge generation layer in the charge connection layer, the stacked organic electroluminescent device has lower voltage, higher luminous efficiency and longer service life.

[0005] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a stacked organic electroluminescent device, comprising an anode, a cathode, and at least two light-emitting units disposed between the anode and the cathode, each of the light-emitting units comprising a light-emitting layer and an electron blocking layer, a charge connection layer being disposed between any two adjacent light-emitting units, the charge connection layer comprising a P-type charge generation layer, the P-type charge generation layer comprising a first host material and a first dopant material;

[0007] The LUMO energy level of the first host material in at least one of the charge connection layers is LUMO PH , the HOMO energy level is HOMO PH ; The LUMO energy level of the first doping material is LUMO PG HOMO PH >LUMO PG ;

[0008] The LUMO energy level of the electron blocking layer material in the light emitting unit adjacent to the charge connection layer and located near the cathode side is LUMO EB , the HOMO energy level is HOMO EB ;LUMO PH >LUMO EB , 0≤HOMO PH -HOMO EB ≤0.30eV;

[0009] The carrier mobility of the first host material in at least one of the charge connection layers is ≥1.0×10 -4 cm 2 ·V -1 ·s -1 .

[0010] In the stacked organic electroluminescent device provided by the present invention, a charge connection layer is provided between two adjacent light-emitting units, and the charge connection layer includes a P-type charge generation layer (P-CGL). The first main material in the P-CGL has a high carrier mobility and excellent carrier transport performance. At the same time, by designing the HOMO energy level of the first main material in at least one (preferably each) P-CGL to be greater than the LUMO energy level of the first doping material, and the first main material in at least one (preferably each) P-CGL and the electron blocking layer material in the adjacent and cathode-proximal light-emitting unit have a specific HOMO / LUMO energy level matching relationship, the hole charge generation capability of the device can be significantly improved, and the rapid injection of hole charges can be ensured to achieve carrier transport balance, thereby increasing the probability of electron and hole recombination and generation of excitons, thereby improving the luminous efficiency and luminous brightness of the stacked organic electroluminescent device, reducing the voltage, and extending the life of the device and display device.

[0011] It should be noted that the number of light-emitting units in the stacked organic electroluminescent device is ≥2, for example, it can be 2, 3, 4, 5, 6, 7, 8, 9, 10, etc.; a charge connection layer is set between any two adjacent light-emitting units, and the charge connection layer includes a P-type charge generation layer, and the direction from the anode to the cathode is the first direction, and the light-emitting units are numbered in sequence according to the first direction, then the i-th light-emitting unit is close to the anode, and the i+1-th light-emitting unit is close to the cathode; i is an integer ≥1; a charge connection layer is set between the i-th light-emitting unit and the i+1-th light-emitting unit, and there is a LUMO between the first host material in the charge connection layer and the electron blocking layer material in the i+1-th light-emitting unit. PH >LUMO EB , and 0≤HOMO PH -HOMO EB The energy level matching relationship of ≤0.30eV is achieved through the matching of HOMO / LUMO energy levels between the layers and the energy level matching of the two materials in the P-type charge generation layer (HOMO PH >LUMO PG ) and carrier mobility (≥1.0×10 -4 cm 2 ·V -1 ·s -1 ) design can ensure that the electrons of the next light-emitting unit (the light-emitting unit close to the cathode, that is, the i+1th light-emitting unit) cannot flow into the previous light-emitting unit (the i-th light-emitting unit), thereby avoiding the non-radiative recombination of electrons and holes, improving the hole charge generation capacity and hole transport capacity of the stacked organic electroluminescent device, and ensuring the rapid transport and injection of hole charges to achieve carrier transport balance, thereby increasing the probability of electron and hole recombination and generating excitons, thereby improving the luminous efficiency and luminous brightness of the stacked organic electroluminescent device, while reducing the voltage and extending the life of the device and display device.

[0012] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the objectives and beneficial effects of the present invention can be better achieved and realized.

[0013] In the present invention, the carrier mobility of the first host material in at least one (more preferably each) of the charge connection layers is ≥1.0×10 -4 cm 2 ·V -1 ·s -1 , for example, it can be 1.1×10 -4 cm 2 ·V -1 ·s -1 , 1.2×10 -4 cm 2·V -1 ·s -1 , 1.3×10 -4 cm 2 ·V -1 ·s -1 , 1.4×10 -4 cm 2 ·V -1 ·s -1 , 1.5×10 -4 cm 2 ·V -1 ·s -1 , 1.6×10 - 4 cm 2 ·V -1 ·s -1 , 1.7×10 -4 cm 2 ·V -1 ·s -1 , 1.8×10 -4 cm 2 ·V -1 ·s -1 , 1.9×10 -4 cm 2 ·V -1 ·s -1 , 2×10 -4 cm 2 ·V -1 ·s -1 , 2.2×10 -4 cm 2 ·V -1 ·s -1 , 2.5×10 -4 cm 2 ·V -1 ·s -1 or 2.8×10 -4 cm 2 ·V -1 ·s -1 wait.

[0014] It should be noted that the carrier mobility of the first host material can be understood as hole carrier mobility.

[0015] In the present invention, 0≤HOMO PH -HOMO EB ≤0.30eV, HOMO PH -HOMO EBIt can be 0, 0.01eV, 0.02eV, 0.05eV, 0.08eV, 0.10eV, 0.12eV, 0.15eV, 0.18eV, 0.20eV, 0.22eV, 0.25eV, 0.28eV, etc., preferably 0≤HOMO PH -HOMO EB ≤0.15eV.

[0016] Preferably, the LUMO energy level of the first host material in at least one (more preferably each) of the charge connection layers is ≥-1.85 eV, for example, PH It may be -1.55 eV, -1.58 eV, -1.60 eV, -1.62 eV, -1.65 eV, -1.68 eV, -1.70 eV, -1.72 eV, -1.75 eV, -1.78 eV, -1.80 eV, -1.82 eV, -1.84 eV, or the like.

[0017] Preferably, the HOMO energy level of the first host material in at least one (more preferably each) of the charge connection layers is -4.96 eV to -5.21 eV, for example, PH It may be -4.96 eV, -4.98 eV, -5.00 eV, -5.02 eV, -5.05 eV, -5.08 eV, -5.10 eV, -5.12 eV, -5.15 eV, -5.18 eV, -5.20 eV, or the like.

[0018] Preferably, the thickness of at least one (more preferably each) of the P-type charge generation layers is 5-15 nm, for example, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, etc., more preferably 8-12 nm.

[0019] Preferably, in at least one (and more preferably each) of the P-type charge generation layers, the mass of the first doping material is 1%-20%, based on the mass of the first main material as 100%, for example, it can be 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, etc., and more preferably 5%-10%.

[0020] Preferably, the light-emitting unit adjacent to the charge connection layer and located near the cathode side also includes a hole transport layer; with the direction from the anode to the cathode as the first direction, the light-emitting unit includes a hole transport layer, an electron blocking layer and a light-emitting layer along the first direction.

[0021] Preferably, the material of the hole transport layer is the same as the first host material in the charge connection layer.

[0022] It is understood that the first light-emitting unit may also include a hole transport layer, an electron blocking layer, and a light-emitting layer along the first direction. The material of the hole transport layer is not specifically limited; a suitable hole-transporting compound may be selected. Preferably, the material of the hole transport layer in the first light-emitting unit is the same as the hole transport material in the second light-emitting unit.

[0023] Preferably, the first host material is independently selected from at least one compound having a structure as shown in any one of Formula I, Formula II, Formula III, and Formula IV:

[0024]

[0025] In Formula I,

[0026] X is selected from O, S, CR 1 R 2 NR 3 or SiR 4 R 5 Any of the following;

[0027] Ar 11 、Ar 12 are each independently selected from any one of substituted phenyl, substituted or unsubstituted C9-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl; and when the Ar 11 Include When Z 1 Selected from O, S, CR A1 R A2 or NR A3 Any one of: -* represents the connecting bond of the group;

[0028] Ar 13 Any one selected from a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group;

[0029] R 1 、R 2 、R 3 、R 4 、R 5 、R A1 、R A2 、R A3 are each independently selected from any one of hydrogen, substituted or unsubstituted C1-C20 straight or branched alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C2-C12 alkenyl, substituted or unsubstituted C2-C12 alkynyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl; the R 1 and R2 、R 4 and R 5 、R A1 and R A2 Each independently is not connected or connected to form a ring through chemical bonds, that is, R 1 and R 2 Not connected or connected to form a ring through chemical bonds, R 4 and R 5 Not connected or connected to form a ring through chemical bonds, R A1 and R A2 Not connected or connected to form a ring through chemical bonds;

[0030] R 11 、R 12 、R 13 Each is independently selected from any one of halogen, cyano, substituted or unsubstituted C1-C20 straight or branched alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C2-C12 alkenyl, substituted or unsubstituted C2-C12 alkynyl, substituted or unsubstituted C6-C30 aryl, and substituted or unsubstituted C3-C30 heteroaryl;

[0031] Ar 11 、Ar 12 、Ar 13 、R 1 、R 2 、R 3 、R 4 、R 5 、R A1 、R A2 、R A3 、R 11 、R 12 、R 13 The substituents are each independently selected from any one or a combination of at least two of halogen, cyano, C1-C10 straight or branched alkyl, C3-C10 cycloalkyl, C2-C10 heterocycloalkyl, C1-C10 alkoxy, C1-C10 alkylthio, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryl, and C3-C30 heteroaryl;

[0032] In the present invention, the "substituted or unsubstituted" group may be substituted with one substituent or with multiple substituents. When there are multiple substituents (at least 2), they may be the same or different substituents. When the same expressions are mentioned below, they have the same meaning. Unless otherwise specified, the selection range of substituents related to Formula I is as shown above and will not be repeated one by one.

[0033] k1, k2, k3 represent substituents R 11 、R12 、R 13 k1 and k2 are each independently selected from integers of 0-3, for example, 0, 1, 2 or 3; k3 is selected from integers of 0-4, for example, 0, 1, 2, 3 or 4. When k1=0, it means that there is no substituent R 11 , the corresponding ring structure is all CH; when k1≥2, multiple R 11 The same applies to k2 and k3, and their descriptions are omitted. The following descriptions of the number of substituents are also similar and are omitted.

[0034] In Formula II, R 21 、R 22 、R 23 、R 24 Each is independently selected from any one of substituted or unsubstituted C1-C30 straight-chain branched alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl; the R 21 and R 22 Not connected or connected to form a ring through chemical bonds, the R 23 and R 24 Not connected or connected to form a ring through chemical bonds;

[0035] R 25 、R 26 Each is independently selected from any one of a substituted or unsubstituted C1-C30 straight or branched alkyl group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C6-C30 aryl group, and a substituted or unsubstituted C3-C30 heteroaryl group;

[0036] L 21 、L 22 are each independently selected from any one of a single bond, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted C3-C30 heteroarylene group; when L 21 、L 22 When it is a single bond, it means that the N atom and the fluorene derivative structure are directly connected through a single bond; the expression of "single bond" below is similar and will not be repeated one by one.

[0037] R 21 、R 22 、R 23 、R 24 、R 25 、R 26 、L 21 、L 22The substituents are each independently selected from any one or a combination of at least two of a C1-C20 straight or branched alkyl group, a C3-C20 cycloalkyl group, a C6-C30 arylamino group, a C3-C30 heteroarylamino group, a C6-C30 aryl group, and a C3-C30 heteroaryl group;

[0038] Unless otherwise specified, R 21 、R 22 、R 23 、R 24 、R 25 、R 26 、L 21 、L 22 The selection ranges of the relevant substituents are as shown above and will not be repeated here.

[0039] Cy is selected from any one of substituted or unsubstituted C6-C30 aryl groups and substituted or unsubstituted C3-C30 heteroaryl groups; the substituents in Cy are each independently selected from any one of C3-C20 cycloalkyl groups, C6-C30 arylamino groups, C3-C30 heteroarylamino groups, C6-C30 aryl groups, and C3-C30 heteroaryl groups, or a combination of at least two thereof;

[0040] n1 and n2 represent substituents R 25 、R 26 The number of R is independently selected from an integer of 0-4, for example, 0, 1, 2, 3 or 4; when n1≥2, multiple (at least 2) R 25 Same or different, adjacent R 25 There is no connection between them; when n2≥2, multiple (at least 2) R 26 Same or different, adjacent R 26 There is no connection between them.

[0041] In formula III,

[0042] Ar 31 、Ar 32 、Ar 33 Each is independently selected from any one of a substituted or unsubstituted C6-C30 aryl group and a substituted or unsubstituted C3-C30 heteroaryl group;

[0043] L 31 、L 32 、L 33 、L 34 Each is independently selected from any one of a single bond, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted C3-C30 heteroarylene group;

[0044] R 31 、R 32 、R33 、R 34 Each is independently selected from any one of halogen, cyano, nitro, hydroxy, amino, substituted or unsubstituted C1-C20 straight or branched alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C1-C20 alkylsilyl, substituted or unsubstituted C6-C60 arylamino, substituted or unsubstituted C3-C60 heteroarylamino, substituted or unsubstituted C6-C60 aryl, and substituted or unsubstituted C3-C60 heteroaryl;

[0045] R 35 Any one selected from substituted or unsubstituted C1-C10 straight or branched alkyl, substituted or unsubstituted C3-C20 cycloalkyl;

[0046] Ar 31 、Ar 32 、Ar 33 、L 31 、L 32 , L 33 , L 34 、R 31 、R 32 、R 33 、R 34 、R 35 The substituents substituted in the above-mentioned group are each independently selected from any one or a combination of at least two of halogen, C1-C20 straight or branched alkyl, C3-C20 cycloalkyl, C2-C20 heterocycloalkyl, C1-C10 alkoxy, carboxyl, nitro, cyano, amino, hydroxyl, thiol, C1-C20 alkylsilyl, C1-C20 alkylamino, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryloxy, C3-C30 heteroaryloxy, C6-C60 aryl, and C3-C60 heteroaryl;

[0047] Unless otherwise specified, the selection ranges of the relevant substituents in Formula III are as shown above and will not be repeated here.

[0048] s1, s2, s3, s4 represent substituents R 31 、R 32 、R 33 、R 34 The number of s1 and s2 is each independently selected from an integer of 0-3, for example, it can be 0, 1, 2 or 3; s3 is selected from an integer of 0-4, for example, it can be 0, 1, 2, 3 or 4; s4 is selected from an integer of 0-5, for example, it can be 0, 1, 2, 3, 4 or 5.

[0049] In Formula IV,

[0050] L 41 , L42 Each is independently selected from any one of a single bond, a substituted or unsubstituted C6-C50 arylene group, and a substituted or unsubstituted C3-C30 heteroarylene group;

[0051] Ar 41 、Ar 42 Each is independently selected from any one of a substituted or unsubstituted C6-C50 aryl group and a substituted or unsubstituted C3-C30 heteroaryl group;

[0052] R 41 、R 42 Each is independently selected from any one of halogen, C1-C20 straight or branched alkyl, C1-C12 alkoxy, C3-C20 cycloalkyl, C2-C12 alkenyl, C2-C12 alkynyl, carboxyl, cyano, amino, C6-C30 arylamino, C3-C30 heteroarylamino, substituted or unsubstituted C6-C50 aryl, and substituted or unsubstituted C3-C30 heteroaryl;

[0053] L 41 , L 42 、Ar 41 、Ar 42 、R 41 、R 42 The substituents are each independently selected from any one or a combination of at least two of halogen, C1-C10 straight or branched alkyl, C3-C10 cycloalkyl, C2-C10 alkenyl, C1-C6 alkoxy, C1-C6 alkylthio, carboxyl, cyano, amino, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryl, and C3-C30 heteroaryl;

[0054] Unless otherwise specified, the selection ranges of the relevant substituents in Formula IV are as shown above and will not be repeated here.

[0055] m1 and m2 represent substituents R 41 、R 42 The number of, m1 is selected from an integer of 0-6, for example, it can be 0, 1, 2, 3, 4, 5 or 6; m2 is selected from an integer of 0-7, for example, it can be 0, 1, 2, 3, 4, 5, 6 or 7.

[0056] In the present invention, the halogen may be fluorine, chlorine, bromine or iodine. The following descriptions of the same elements have the same meanings.

[0057] In the present invention, the expression of chemical elements, unless otherwise specified, includes the concept of isotopes with the same chemical properties. For example, hydrogen (H) includes 1 H (hydrogen), 2 H (deuterium, D), 3H (tritium, T), etc.; carbon (C) includes 12 C. 13 C, etc.

[0058] In the present invention, unless otherwise specified, the heteroatom of the heteroaryl group is selected from N, O, S, P, B, Si or Se, preferably N, O or S.

[0059] 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.

[0060] In the present invention, "-*" and "*" both represent the attachment site of a group.

[0061] In the present invention, the expression Ca-Cb represents that the number of carbon atoms in the group is ab. Unless otherwise specified, the number of carbon atoms does not include the number of carbon atoms in the substituent.

[0062] In the present invention, “each independently” means that when there are multiple subjects, they may be the same or different.

[0063] In the present invention, the C9-C30 can all be C9, C10, C12, C14, C16, C18, C20, C22, C24, C26, C28, etc.

[0064] The C6-C30 can all be C6, C9, C10, C12, C14, C16, C18, C20, C22, C24, C26, C28, etc.

[0065] The C3-C30 can all be C3, C4, C5, C6, C9, C10, C12, C14, C16, C18, C20, C22, C24, C26, C28, etc.

[0066] The C1-C20 can all be C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, etc.

[0067] The C3-C20 can all be C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, etc.

[0068] The C2-C12 can all be C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, or C12.

[0069] The C1-C10 can all be C2, C3, C4, C5, C6, C7, C8, C9, etc.

[0070] The C3-C10 can all be C4, C5, C6, C7, C8, C9, etc.

[0071] The C2-C10 can all be C3, C4, C5, C6, C7, C8, C9, etc.

[0072] The C1-C30 can all be C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, C20, C22, C24, C26, C28, etc.

[0073] The C6-C60 can all be C6, C9, C10, C12, C14, C16, C18, C20, C22, C24, C26, C28, C30, C32, C34, C36, C38, C40, C42, C44, C46, ​​C48, C50, C52, C54, C56, C58, etc.

[0074] The C3-C60 can all be C3, C4, C5, C6, C9, C10, C12, C14, C16, C18, C20, C22, C24, C26, C28, C30, C32, C34, C36, C38, C40, C42, C44, C46, ​​C48, C50, C52, C54, C56, C58, etc.

[0075] The C2-C20 can all be C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, etc.

[0076] The C6-C50 can be C6, C9, C10, C12, C14, C16, C18, C20, C22, C24, C26, C28, C30, C32, C34, C36, C38, C40, C42, C44, C46, ​​C48, etc.

[0077] The C1-C6 can all be C2, C3, C4, C5, C6, etc.

[0078] In the present invention, the C6-C60 aryl, C6-C50 aryl, C6-C30 aryl, preferably C6-C20 aryl, includes monocyclic aryl and condensed ring aryl; the monocyclic aryl means that the group contains at least one phenyl group, and when it contains at least two phenyl groups, the phenyl groups are connected by a single bond, illustratively including but not limited to: phenyl, biphenyl, terphenyl, etc.; the condensed ring aryl means that the group contains at least two aromatic rings, and the aromatic rings share two The groups in which adjacent carbon atoms are fused to each other include, but are not limited to, naphthyl, anthracenyl, phenanthrenyl, indenyl, fluorenyl and its derivatives (9,9-dimethylfluorenyl, 9,9-diethylfluorenyl, 9,9-dipropylfluorenyl, 9,9-dibutylfluorenyl, 9,9-dipentylfluorenyl, 9,9-dihexylfluorenyl, 9,9-diphenylfluorenyl, 9,9-dinaphthylfluorenyl, spirobifluorenyl, benzofluorenyl, etc.), fluoranthenyl, triphenylene, pyrenyl, perylene, phenyl or tetraphenyl etc.

[0079] The C3-C60 heteroaryl group, C3-C30 heteroaryl group, preferably C3-C20 heteroaryl group, includes a monocyclic heteroaryl group or a condensed ring heteroaryl group. The monocyclic heteroaryl group means that the molecule contains at least one heteroaryl group. When the molecule contains a heteroaryl group and other groups (such as aryl, heteroaryl, etc.), the heteroaryl group and the other group are connected by a single bond, and illustratively include but are not limited to: pyridyl, pyrimidinyl, pyrazinyl, pyridazinyl, triazinyl, furyl, thienyl, pyrrolyl, triazolyl, etc. The fused-ring heteroaryl group means a group containing at least one aromatic heterocycle and one aromatic ring (aromatic heterocycle or aromatic ring) in the molecule, and the two share two adjacent atoms fused to each other, including but not limited to: quinolyl, isoquinolyl, quinoxalinyl, quinazolinyl, benzimidazolyl, benzofuranyl, benzothiophenyl, isobenzofuranyl, isobenzothiophenyl, indolyl, dibenzofuranyl, dibenzothiophenyl, carbazolyl and its derivatives (N-phenylcarbazolyl, N-naphthylcarbazolyl, benzocarbazolyl, dibenzocarbazolyl, indolecarbazolyl, azacarbazolyl, etc.), acridinyl, phenothiazinyl, phenoxazinyl, hydroacridinyl, benzofurancarbazolyl, benzothiophenecarbazolyl, azadibenzothiophenyl, azadibenzofuranyl, etc.

[0080] Specific examples of the C6-C30 arylene group and the C6-C50 arylene group include divalent groups obtained by removing one hydrogen atom from the above examples of the aryl group; specific examples of the C3-C30 heteroarylene group include divalent groups obtained by removing one hydrogen atom from the above examples of the heteroaryl group.

[0081] In the present invention, the C6-C30 aryloxy group is a monovalent group formed by connecting the above-mentioned aryl groups with O, and the C3-C30 heteroaryloxy group is a monovalent group formed by connecting the above-mentioned heteroaryl groups with O.

[0082] In the present invention, specific examples of the C6-C60 arylamino group and the C6-C30 arylamino group are monovalent groups in which at least one hydrogen in -NH2 is replaced by the above-mentioned aryl group, and illustratively include but are not limited to: phenylamino, methylphenylamino, naphthylamino, anthrylamino, phenanthrenylamino, biphenylamino, etc. Specific examples of the C3-C60 heteroarylamino group and the C3-C30 heteroarylamino group are monovalent groups in which at least one hydrogen in -NH2 is replaced by the above-mentioned heteroaryl group, and illustratively include but are not limited to: pyridylamino, pyrimidinylamino, dibenzofuranylamino, etc.

[0083] The C1-C30 straight chain or branched alkyl group, C1-C20 straight chain or branched alkyl group, C1-C10 straight chain or branched alkyl group, preferably C1-C6 straight chain or branched alkyl group, illustratively include but are not limited to: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, 2-methylbutyl, n-pentyl, isopentyl, neopentyl, n-hexyl, neohexyl, 2-ethylhexyl, n-octyl, n-heptyl, n-nonyl, n-decyl, etc.

[0084] Specific examples of the C1-C20 alkoxy, C1-C12 alkoxy, C1-C10 alkoxy, and C1-C6 alkoxy groups include monovalent groups formed by connecting the above-mentioned linear or branched alkyl groups to O. Specific examples of the C1-C10 alkylthio and C1-C6 alkylthio groups include monovalent groups formed by connecting the above-mentioned linear or branched alkyl groups to S.

[0085] A specific example of the C1-C20 alkylsilyl group is a monovalent group in which at least one hydrogen in -SiH3 is replaced by the above-mentioned straight-chain or branched alkyl group; a specific example of the C1-C20 alkylamino group is a monovalent group in which at least one hydrogen in -NH2 is replaced by the above-mentioned straight-chain or branched alkyl group.

[0086] The C3-C20 cycloalkyl and C3-C10 cycloalkyl groups include monocyclic and polycyclic alkyl groups. A monocyclic alkyl group refers to an alkyl group containing a single cyclic structure, and a polycyclic alkyl group refers to a structure composed of two or more cycloalkyl groups sharing one or more ring carbon atoms. Examples thereof include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and adamantyl groups.

[0087] Specific examples of the C2-C20 heterocycloalkyl group and the C2-C10 heterocycloalkyl group include monovalent groups formed by replacing at least one carbon atom in the above cycloalkyl group with a heteroatom (such as N, O or S, etc.), including but not limited to epoxy, oxetanyl, tetrahydrofuranyl, tetrahydrothiophenyl, tetrahydropyrrolyl, tetrahydropyranyl, piperidinyl, piperazinyl, dioxane, morpholinyl and the like.

[0088] The C2-C12 alkenyl and C2-C10 alkenyl groups, which contain at least one C=C, illustratively include but are not limited to: vinyl, propenyl, allyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, butadienyl, pentadienyl, etc.

[0089] The C2-C12 alkynyl group and the C2-C10 alkynyl group contain at least one C≡C, and illustratively include but are not limited to ethynyl, propynyl, butynyl, and the like.

[0090] In formula I, X is selected from O, S, CR 1 R 2 NR 3 or SiR 4 R 5 Any one, preferably CR 1 R 2 NR 3 or SiR 4 R 5 , more preferably CR 1 R 2 .

[0091] Preferably, the R 1 、R 2 、R 3 、R 4 、R 5 Each is independently selected from any one of substituted or unsubstituted C1-C6 (for example, C2, C3, C4, C5, etc.) straight chain or branched alkyl groups, substituted or unsubstituted C6-C20 (for example, C6, C7, C8, C9, C10, C12, C14, C16 or C18, etc.) aryl groups, further preferably any one of C1-C6 straight chain or branched alkyl groups, phenyl groups, biphenyl groups, terphenyl groups, and naphthyl groups, more preferably methyl groups or phenyl groups.

[0092] Preferably, the R 1 and R 2 Not connected or connected by chemical bonds to form a spirobifluorene ring, and / or, the R 4 and R 5 Not connected or connected to form a ring through chemical bonds.

[0093] Preferably, in Formula I, Ar 11 、Ar 12 Each is independently selected from any one of the following substituted or unsubstituted groups:

[0094] Wherein, -* represents the attachment site of the group; R 01 、R 02 Each independently represents a single substitution up to the maximum permissible substitution;

[0095] R 01 、R 02 Each is independently selected from any one or a combination of at least two of cyano, halogen, C1-C10 (e.g., C2, C3, C4, C5, C6, C7, C8, C9, etc.) straight or branched alkyl, C3-C10 (e.g., C3, C4, C5, C6, C7, C8, C9, etc.) cycloalkyl, C6-C20 (e.g., C6, C7, C8, C9, C10, C12, C14, C16 or C18, etc.) aryl, C3-C20 (e.g., C4, C5, C6, C7, C8, C9, C10, C12, C14, C16 or C18, etc.) heteroaryl, and more preferably any one of cyano, fluorine, C1-C6 straight or branched alkyl, C3-C6 cycloalkyl, phenyl, biphenyl, terphenyl, naphthyl, and pyridyl.

[0096] Preferably, in Formula I, Ar 13 Any one selected from substituted or unsubstituted C6-C20 (e.g., C6, C7, C8, C9, C10, C12, C14, C16 or C18, etc.) aryl, substituted or unsubstituted C3-C20 (e.g., C4, C5, C6, C7, C8, C9, C10, C12, C14, C16 or C18, etc.) heteroaryl, further preferably any one of the following substituted or unsubstituted groups:

[0097] Preferably, in Formula I, the R 11 、R 12 、R 13 Each is independently selected from any one of halogen, cyano, substituted or unsubstituted C1-C6 straight or branched alkyl, substituted or unsubstituted C3-C6 cycloalkyl, substituted or unsubstituted C6-C20 aryl, and substituted or unsubstituted C3-C20 heteroaryl.

[0098] Preferably, in Formula I, k1, k2 and k3 are all 0; or, k1 is 0, k2 is 0 or 1, and k3 is 1 or 2.

[0099] Preferably, the compound having the structure shown in Formula I is selected from any one of the structures shown in the following compounds A1-A590:

[0100]

[0101]

[0102]

[0103]

[0104]

[0105]

[0106]

[0107]

[0108]

[0109]

[0110]

[0111]

[0112]

[0113]

[0114]

[0115]

[0116]

[0117]

[0118]

[0119]

[0120]

[0121]

[0122]

[0123]

[0124]

[0125]

[0126]

[0127]

[0128]

[0129]

[0130]

[0131]

[0132]

[0133]

[0134]

[0135]

[0136]

[0137]

[0138]

[0139] Preferably, in Formula II, the R 21 、R 22 、R 23 、R 24 Each is independently selected from any one of substituted or unsubstituted C1-C10 (for example, C2, C3, C4, C5, C6, C7, C8, C9, etc.) linear or branched alkyl groups, substituted or unsubstituted C3-C10 (for example, C4, C5, C6, C7, C8, C9, etc.) cycloalkyl groups, and substituted or unsubstituted C6-C20 (for example, C6, C7, C8, C9, C10, C12, C14, C16 or C18, etc.) aryl groups.

[0140] Preferably, the R 21 and R 22 Not connected or connected to ring A1 by chemical bonds, the R 23 and R 24 Not connected or connected by chemical bonds to form ring A2; the ring A1 and ring A2 are each independently selected from any one of a C3-C12 (e.g., C3, C4, C5, C6, C7, C8, C9, C10, C11, etc.) alicyclic rings or C6-C20 (e.g., C6, C7, C8, C9, C10, C12, C14, C16 or C18, etc.) aromatic rings, and more preferably any one of an adamantane ring, a fluorene ring or a benzofluorene ring.

[0141] Preferably, in Formula II, the R25 、R 26 Each is independently selected from any one of substituted or unsubstituted C1-C6 (for example, C2, C3, C4, C5, etc.) straight chain or branched alkyl, substituted or unsubstituted C3-C10 (for example, C4, C5, C6, C7, C8, C9, etc.) cycloalkyl, substituted or unsubstituted C6-C20 (for example, C6, C7, C8, C9, C10, C12, C14, C16 or C18, etc.) aryl, further preferably any one of C1-C6 straight chain or branched alkyl, phenyl, biphenyl, terphenyl, naphthyl, more preferably methyl or phenyl.

[0142] Preferably, in Formula II, n1 and n2 are each independently 0 or 1.

[0143] Preferably, in Formula II, the L 21 、L 22 Each is independently selected from any one of a single bond, a substituted or unsubstituted C6-C20 (e.g., C6, C7, C8, C9, C10, C12, C14, C16 or C18, etc.) arylene group, and a substituted or unsubstituted C3-C20 (e.g., C4, C5, C6, C7, C8, C9, C10, C12, C14, C16 or C18, etc.) heteroarylene group, and is further preferably any one of a single bond, a substituted or unsubstituted group selected from the following groups: Wherein, -* represents the attachment site of the group.

[0144] Preferably, in Formula II, the Cy is selected from any one of substituted or unsubstituted C6-C20 (e.g., C6, C7, C8, C9, C10, C12, C14, C16 or C18, etc.) aryl groups, and further preferably any one of the following substituted or unsubstituted groups: Wherein, -* represents the attachment site of the group.

[0145] Preferably, in Formula II, the Cy is not a dimethylfluorenyl group.

[0146] Preferably, the compound having the structure represented by Formula II is selected from any one of the structures represented by the following compounds C1-C318:

[0147]

[0148]

[0149]

[0150]

[0151]

[0152]

[0153]

[0154]

[0155]

[0156]

[0157]

[0158]

[0159]

[0160]

[0161]

[0162]

[0163] Preferably, in formula III, the Ar 31 、Ar 32 、Ar 33 Each is independently selected from any one of a substituted or unsubstituted C6-C20 (e.g., C6, C7, C8, C9, C10, C12, C14, C16 or C18, etc.) aryl group, a substituted or unsubstituted C3-C20 (e.g., C4, C5, C6, C7, C8, C9, C10, C12, C14, C16 or C18, etc.) heteroaryl group, and is further preferably any one of the following substituted or unsubstituted groups:

[0164] Preferably, in Formula III, the L 31 、L 32 、L 33 、L 34Each is independently selected from any one of a single bond, a substituted or unsubstituted C6-C20 (e.g., C6, C7, C8, C9, C10, C12, C14, C16 or C18, etc.) arylene group, and a substituted or unsubstituted C3-C20 (e.g., C4, C5, C6, C7, C8, C9, C10, C12, C14, C16 or C18, etc.) heteroarylene group, and is further preferably any one of a single bond, a substituted or unsubstituted group selected from the following groups:

[0165] Preferably, in Formula III, the R 35 Any one selected from substituted or unsubstituted C1-C6 (e.g. C2, C3, C4, C5, etc.) straight or branched alkyl groups, substituted or unsubstituted C3-C6 (e.g. C3, C4, C5, etc.) cycloalkyl groups.

[0166] Preferably, the compound having the structure represented by Formula III is selected from any one of the structures represented by the following compounds P1-P624:

[0167]

[0168]

[0169]

[0170]

[0171]

[0172]

[0173]

[0174]

[0175]

[0176]

[0177]

[0178]

[0179]

[0180]

[0181]

[0182]

[0183]

[0184]

[0185]

[0186]

[0187]

[0188]

[0189]

[0190]

[0191]

[0192]

[0193] The compound of formula IV has a structure as shown in formula IV-1 or formula IV-2, preferably the structure of formula IV-1: Among them, L 41 , L 42 、Ar 41 、Ar 42 、R 41 、R 42 , m1, and m2 have the same defined ranges as in Formula IV.

[0194] Preferably, the L 41 , L 42 Each is independently selected from any one of a single bond, a substituted or unsubstituted C6-C20 (e.g., C6, C7, C8, C9, C10, C12, C14, C16 or C18, etc.) arylene group, and a substituted or unsubstituted C3-C20 heteroarylene group (e.g., C4, C5, C6, C7, C8, C9, C10, C12, C14, C16 or C18, etc.), and is further preferably any one of a single bond, a substituted or unsubstituted group as follows:

[0195] Preferably, the Ar 41 、Ar 42Each is independently selected from any one of a substituted or unsubstituted C6-C20 (e.g., C6, C7, C8, C9, C10, C12, C14, C16 or C18, etc.) aryl group, a substituted or unsubstituted C3-C20 (e.g., C4, C5, C6, C7, C8, C9, C10, C12, C14, C16 or C18, etc.) heteroaryl group, and is further preferably any one of the following substituted or unsubstituted groups:

[0196] Preferably, the compound having the structure represented by Formula IV is selected from any one of the structures represented by the following compounds B1-B417:

[0197]

[0198]

[0199]

[0200]

[0201]

[0202]

[0203]

[0204]

[0205]

[0206]

[0207]

[0208]

[0209]

[0210]

[0211]

[0212]

[0213] Preferably, the first doping materials are each independently an electron acceptor compound.

[0214] Preferably, the first doping materials are each independently selected from any one or a combination of at least two of the following compounds:

[0215] Preferably, the electron blocking layers in the light-emitting units are made of the same material.

[0216] Preferably, the charge connection layer also includes an N-type charge generation layer (N-CGL), and the N-type charge generation layer is located on the near-anode side of the charge connection layer; that is, with the direction from the anode to the cathode as the first direction, the charge connection layer includes an N-type charge generation layer and a P-type charge generation layer along the first direction.

[0217] Preferably, the N-type charge generation layer includes a second host material and a second doping material.

[0218] Preferably, the second host material is selected from at least one compound having a structure as shown in Formula V;

[0219] R 51 -QR 52 Formula V;

[0220] In formula V, the bridging group Q is selected from one of the substituted or unsubstituted groups:

[0221]

[0222]

[0223] Among them, the wavy line and the *wavy line represent the two connection sites of the group respectively.

[0224] In formula V, R 51 、R 52 Each is independently selected from any one of substituted or unsubstituted C3-C60 heteroaryl groups, wherein the heteroaryl group contains at least one nitrogen atom.

[0225] Q, R 51 、R 52 The substituents are each independently selected from any one or a combination of at least two of cyano, halogen, C1-C10 straight or branched alkyl, C3-C10 cycloalkyl, silicon, C6-C60 arylphosphino, C6-C60 arylphosphinooxy, C6-C30 arylamine, C6-C30 aryl, and C2-C30 heteroaryl; R 61 、R 62 The substituted substituents are each independently not connected to the adjacent ring structure or are connected to form a ring through a chemical bond.

[0226] For example, the second main material includes but is not limited to any one or a combination of at least two of the following L1-L90:

[0227]

[0228]

[0229]

[0230]

[0231]

[0232]

[0233]

[0234]

[0235]

[0236] Preferably, the second doping material independently includes a metal and / or a metal salt, and more preferably any one or a combination of at least two of LiQ, LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Na, Li, Ca, Mg, and Yb.

[0237] Preferably, in at least one (and more preferably each) of the N-type charge generation layers, the mass of the second doping material is 0.1%-20%, based on the mass of the second main material as 100%, for example, it can be 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, etc., and more preferably 1%-10%.

[0238] Preferably, the thickness of at least one (more preferably each) of the N-type charge generation layers is 5-15 nm, for example, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, etc., more preferably 9-11 nm.

[0239] Preferably, at least one (more preferably each) of the light-emitting units is independently selected from any one of a blue light-emitting unit, a red light-emitting unit or a green light-emitting unit.

[0240] Preferably, each of the light-emitting units further includes a hole blocking layer and / or an electron transport layer.

[0241] Preferably, with the direction from the anode to the cathode being the first direction, each of the light-emitting units independently comprises a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer and an electron transport layer sequentially arranged along the first direction;

[0242] Preferably, a hole injection layer is further provided on the side of the anode close to the light-emitting unit;

[0243] Preferably, an electron injection layer is further provided on a side of the cathode close to the light-emitting unit.

[0244] In a preferred embodiment, a substrate is provided on the side of the anode facing away from the light-emitting unit or the side of the cathode facing away from the light-emitting unit. The substrate is made of glass or a polymer material with excellent mechanical strength, thermal stability, water resistance, and transparency. Furthermore, the substrate used for the display may also include thin-film transistors (TFTs).

[0245] In a preferred technical solution, the anode can be formed by sputtering or depositing a material used as an anode on a substrate; for example, transparent conductive oxide materials such as indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (SnO2), zinc oxide (ZnO), and any combination thereof can be used. The cathode can be made of metals or alloys such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), ytterbium (Yb), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), and any combination thereof. The anode in the present invention is preferably ITO.

[0246] The organic layer in each light-emitting unit can be formed on the electrode by vacuum thermal evaporation, spin coating, printing, etc. The compound used as the organic layer can be an organic small molecule, an organic macromolecule or a polymer, or a combination thereof.

[0247] In a preferred technical solution, the material of the hole transport layer can be selected from, but not limited to, phthalocyanine derivatives such as CuPc, conductive polymers or polymers containing conductive dopants such as polyphenylene ethylene, polyaniline / dodecylbenzenesulfonic acid (Pani / DBSA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / camphorsulfonic acid (Pani / CSA), polyaniline / poly(4-styrenesulfonate) (Pani / PSS), aromatic amine derivatives, or one or more compounds of A1-A590, C1-C318, P1-P624, B1-B419 mentioned above; wherein the aromatic amine derivatives include the compounds shown below as HT-1 to HT-54; or any combination thereof.

[0248]

[0249]

[0250]

[0251] In a preferred technical solution, the hole injection layer can be a single compound material or a combination of multiple compounds. For example, the hole injection layer can use one or more compounds from HT-1 to HT-54 described above, or one or more compounds from HI-1 to HI-3 described below, or one or more compounds from A1-A590, C1-C318, P1-P624, and B1-B417 described above. It can also use one or more compounds from HT-1 to HT-54 doped with one or more compounds from HI-1 to HI-3 described below. It can also use one or more compounds from A1-A590, C1-C318, P1-P624, and B1-B417 doped with one or more compounds from HI-1 to HI-3 described below. Preferably, the material of the hole injection layer is the same as that of the P-type charge generation layer.

[0252]

[0253] In a preferred technical solution, the material of the electron blocking layer may be, but is not limited to, one or more compounds of HT-1 to HT-54 described above, or one or more compounds of PH-47 to PH-77 described below; or a mixture of, but not limited to, one or more compounds of HT-1 to HT-54 and one or more compounds of PH-47 to PH-77.

[0254]

[0255]

[0256] The light-emitting layer includes a host material (Host) and a luminescent dye (i.e., a dopant) that can emit light of different wavelengths. The light-emitting layer can be a single-color light-emitting layer that emits a single color, such as red, green, or blue. Multiple single-color light-emitting layers of different colors can be arranged in a planar pattern according to a pixel pattern, or they can be stacked together to form a multi-color light-emitting layer. When light-emitting layers of different colors are stacked together, they can be separated from each other or connected to each other. The light-emitting layer can also be a single-color light-emitting layer that can simultaneously emit different colors, such as red, green, and blue.

[0257] Depending on the technology, the light-emitting layer material can be fluorescent or phosphorescent. An OLED device can employ a single light-emitting technology or a combination of multiple technologies. These different light-emitting materials, categorized by technology, can emit the same or different colors of light.

[0258] In a preferred technical solution, the light-emitting layer adopts fluorescent electroluminescence technology. The fluorescent host material of the light-emitting layer can be selected from, but not limited to, one or more combinations of BFH-1 to BFH-17 listed below.

[0259]

[0260]

[0261] In a preferred technical solution, the light-emitting layer adopts fluorescent electroluminescence technology. The fluorescent dopant (including blue light dye) of the light-emitting layer can be selected from, but not limited to, one or more combinations of BFD-1 to BFD-24 listed below.

[0262]

[0263]

[0264] In a preferred technical solution, the light-emitting layer adopts phosphorescent luminescence technology, and the host material is selected from, but not limited to, one or more combinations of PH-1 to PH-85.

[0265]

[0266]

[0267]

[0268]

[0269] In a preferred technical solution, the light-emitting layer adopts phosphorescent electroluminescence technology, and the doping material (phosphorescent doping material, also known as guest material, dye) includes a green light material, which can be selected from, but not limited to, one or more combinations of GPD-1 to GPD-47 listed below.

[0270] Where D is deuterium.

[0271] In a preferred technical solution, the light-emitting layer adopts phosphorescent electroluminescence technology, and the doping material of the light-emitting layer includes a red light material, which can be selected from but not limited to one or more combinations of RPD-1 to RPD-28 listed below.

[0272]

[0273]

[0274] In a preferred technical solution, the light-emitting layer adopts phosphorescent electroluminescence technology, and the doping material of the light-emitting layer can be selected from, but not limited to, one or more combinations of YPD-1 to YPD-11 listed below.

[0275]

[0276]

[0277] In a preferred technical solution, the material of the electron transport layer can be selected from, but not limited to, any one or a combination of at least two of the compounds ET-1 to ET-73 listed below.

[0278]

[0279]

[0280]

[0281]

[0282] In a preferred embodiment, a hole-blocking layer (HBL) is located between the electron-transporting layer and the light-emitting layer. The hole-blocking layer can be composed of, but not limited to, one or more of the compounds ET-1 to ET-73, or one or more of the compounds PH-1 to PH-46; or a mixture of, but not limited to, one or more of the compounds ET-1 to ET-73 and one or more of the compounds PH-1 to PH-46.

[0283]

[0284]

[0285]

[0286] In a preferred technical solution, the material of the electron injection layer includes but is not limited to one or more combinations of the following: LiQ, LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Na, Li, Ca, Mg or Yb.

[0287] In a preferred technical solution, the cathode can be made of metals or alloys such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), ytterbium (Yb), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), and any combination thereof. It can also be made of metals such as ITO, metal mixtures, oxides, etc. The cathode of the present invention is preferably a magnesium-silver (Mg-Ag) combination.

[0288] In a second aspect, the present invention provides a display device, comprising the stacked organic electroluminescent device according to the first aspect.

[0289] Compared with the prior art, the present invention has the following beneficial effects:

[0290] In the stacked organic electroluminescent device provided by the present invention, the hole charge generation capacity and hole transport capacity of the device can be significantly improved through the material design of the P-type charge generation layer in the charge connection layer, the design of the carrier mobility, and the energy level matching between the materials, thereby ensuring that the hole charge can be quickly injected and transported, and avoiding the non-radiative recombination of electrons and holes, reducing carrier accumulation, thereby achieving carrier transport balance, and increasing the probability of electron and hole recombination and generating excitons, so that the stacked organic electroluminescent device has higher luminous efficiency and luminous brightness, while reducing voltage and energy consumption, and extending the life of the device and display device. BRIEF DESCRIPTION OF THE DRAWINGS

[0291] Figure 1 A schematic structural diagram of a stacked organic electroluminescent device provided in one embodiment of the present invention;

[0292] Among them, 1-glass substrate, 2-anode, 3-hole injection layer, 4-first hole transport layer, 5-first electron blocking layer, 6-first light-emitting layer, 7-first hole blocking layer, 8-first electron transport layer, 9-N-type charge generation layer, 10-P-type charge generation layer, 11-second hole transport layer, 12-second electron blocking layer, 13-second light-emitting layer, 14-second hole blocking layer, 15-second electron transport layer, 16-electron injection layer, 17-cathode, and 18-external power supply. DETAILED DESCRIPTION

[0293] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0294] In a specific embodiment, the HOMO energy level of the first host material is -4.96 eV to -5.21 eV.

[0295] In one embodiment, the LUMO energy level of the first host material is ≥-1.85 eV.

[0296] In one embodiment, the LUMO energy level and HOMO energy level of the organic material are tested as follows:

[0297] Cyclic voltammetry was performed on the main material to be tested using an electrochemical workstation. The workstation used a three-electrode system with a platinum electrode as the working electrode, a platinum wire electrode as the counter electrode, and an Ag wire electrode as the reference electrode. 0.5 g of the sample to be tested was dissolved in 5 mL of ultra-dry tetrahydrofuran. Tetrabutylammonium perchlorate was used as the electrolyte salt. The test sample was protected by nitrogen. The voltage range was -2 V to 2 V, the scan rate was 100 mV / s, and the number of scans was 2. On the CV curve, the peak value, i.e., the oxidation potential E, was read. ox and reduction potential E red , according to the same settings as above, test the oxidation potential E of ferrocene Fe Calculated HOMO = -((E ox -E Fe )+4.8), LUMO=-((E red -E Fe )+4.8).

[0298] In a specific embodiment, the hole carrier mobility of the first host material is ≥1.0×10 - 4 cm 2 ·V -1 ·s -1 .

[0299] In one embodiment, the hole carrier mobility of the first host material is tested as follows:

[0300] The glass substrate coated with the ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone / ethanol mixed solvent, baked in a clean environment until the water was completely removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam. The glass substrate with the anode was placed in a vacuum chamber and evacuated to a vacuum of less than 1×10 -5 On the anode layer, a hole-only charge carrier device was fabricated by sequentially vacuum-depositing a 10nm mixture of the compounds HT-53:HI-2 (97 / 3, w / w), 150nm of the material to be tested, 3nm of HI-2, and 13nm of Mg:Ag (1:9, mass ratio) onto the aforementioned anode layer. The IV characteristics of the single-carrier device were measured using a digital source meter and a luminance meter. The carrier mobility was calculated using the SCLC (space charge limited current) method at an electric field strength of 0.14mV / cm for data accumulation and comparison.

[0301] The data of LUMO energy level, HOMO energy level and hole carrier mobility of representative organic materials are shown in Table 1:

[0302] Table 1

[0303] Material No. HOMO(eV) LUMO(eV) <![CDATA[Hole carrier mobility (cm 2 ·V -1 ·s -1 )]]> A16 -5.18 -1.60 <![CDATA[1.38×10 -4 ]]> C2 -5.20 -1.63 <![CDATA[1.49×10 -4 ]]> C7 -5.13 -1.84 <![CDATA[1.93×10 -4 ]]> P57 -5.16 -1.73 <![CDATA[1.60×10 -4 ]]> P14 -5.18 -1.60 <![CDATA[1.41×10 -4 ]]> B135 -5.19 -1.83 <![CDATA[1.60×10 -4 ]]> HT-53 -5.19 -1.59 <![CDATA[1.14×10 -4 ]]> HT-54 -5.26 -1.85 <![CDATA[4.50×10 -5 ]]> HTL1 -5.19 -1.61 <![CDATA[8.43×10 -5 ]]> EBL1 -5.09 -2.14 / HI-2 / -5.3 /

[0304] HTL1 and EBL1 in Table 1 are

[0305] Example 1

[0306] A stacked organic electroluminescent device comprises an anode, a cathode and two light-emitting units arranged between the anode and the cathode, and its structural schematic diagram is shown as follows Figure 1 As shown, it specifically includes a glass substrate 1, an anode 2 (ITO), a hole injection layer 3, a first hole transport layer 4, a first electron blocking layer 5, a first light-emitting layer 6, a first hole blocking layer 7, a first electron transport layer 8, an N-type charge generation layer 9, a P-type charge generation layer 10, a second hole transport layer 11, a second electron blocking layer 12, a second light-emitting layer 13, a second hole blocking layer 14, a second electron transport layer 15, an electron injection layer 16, and a cathode 17 (magnesium silver electrode) stacked in sequence; the anode 2 and the cathode 17 are respectively connected to an external power supply 18.

[0307] The preparation method of the stacked organic electroluminescent device is as follows:

[0308] (1) A glass substrate coated with an ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone / ethanol mixed solvent, baked in a clean environment until the water was completely removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam;

[0309] (2) Place the glass substrate with the anode in a vacuum chamber and evacuate to a vacuum of <1×10 -5 Pa, vacuum evaporating 10 nm of a mixture of compound HT-53:HI-2 (97 / 3, w / w) on the above anode layer as a hole injection layer;

[0310] (3) Vacuum evaporation to prepare the first light-emitting unit:

[0311] On the hole injection layer, 25 nm of compound HT-53 was vacuum-deposited as the first hole transport layer, 6 nm of compound HT-54 was vacuum-deposited as the first electron blocking layer, 40 nm of a ternary mixture of compound PH-61:PH-3:GPD-12 (100:100:20, w / w / w) was vacuum-deposited as the first light-emitting layer, 5 nm of compound ET-23 was vacuum-deposited as the first hole blocking layer, and 20 nm of a mixture of compound ET-69:LiQ (50 / 50, w / w) was vacuum-deposited as the first electron transport layer to obtain the first light-emitting unit.

[0312] (4) Vacuum evaporation to prepare the charge connection layer:

[0313] A 10.5 nm layer of compound L1:Yb (100:5, w / w) was vacuum-evaporated on the first electron transport layer as an N-type charge generation layer (N-CGL); a 10.75 nm layer of a compound A16:HI-2 (100 / 7.5, w / w) mixture was vacuum-evaporated on the N-type charge generation layer as a P-type charge generation layer (P-CGL);

[0314] (5) Vacuum evaporation to prepare the second light-emitting unit:

[0315] On the P-type charge generation layer, 25 nm of compound HT-53 was evaporated as a second hole transport layer, 6 nm of compound HT-54 was evaporated as a second electron blocking layer, 40 nm of a ternary mixture of compound PH-61:PH-3:GPD-12 (100:100:20, w / w / w) was evaporated as a second light-emitting layer, 5 nm of compound ET-23 was evaporated as a second hole blocking layer, and 20 nm of a mixture of compound ET-69:LiQ (50 / 50, w / w) was evaporated as a second electron transport layer to obtain a second light-emitting unit;

[0316] (6) Evaporating 1 nm of Yb on the second electron transport layer as an electron injection layer;

[0317] (7) Vacuum-depositing 13 nm of Mg:Ag (1:9) as a cathode on the electron injection layer to obtain the stacked organic electroluminescent device; during the aforementioned vacuum evaporation process, the total evaporation rate of all organic layers is controlled at 0.1 nm / s, the dye evaporation rate is controlled at 0.03 nm / s, the Yb evaporation rate is controlled at 0.1 nm / s, and the Mg and Ag evaporation rates of the metal electrodes are controlled at 0.2 nm / s and 1.8 nm / s respectively.

[0318] Examples 2-36, Comparative Examples 1-5

[0319] A stacked organic electroluminescent device differs from Example 1 only in that the first host material in the P-type charge generation layer, the hole transport layer material in the second light-emitting unit, the electron blocking layer material, and the hole transport layer material in the third light-emitting unit are as shown in Tables 2 and 3; for a stacked organic electroluminescent device having two light-emitting units, the host material in the hole injection layer, the hole transport layer material in the first light-emitting unit, and the hole transport layer material in the second light-emitting unit are the same (such as the second HTL shown in Table 2); for a stacked organic electroluminescent device having more than two light-emitting units, the host material in the hole injection layer, the hole transport layer material in the first light-emitting unit, and the hole transport layer material in the second light-emitting unit are the same (such as the second HTL shown in Table 3), and the hole transport layer material in the third light-emitting unit is shown in the third HTL in Table 3; other layers, thicknesses, and materials not shown in Tables 2 and 3 are the same as those in Example 1.

[0320] For a stacked organic electroluminescent device with a number of light-emitting units greater than 2, the preparation method is different from that of Example 1 in that, according to the above description, Table 2, and Table 3, steps (4) and (5) are repeated until the preparation of all charge connection layers and light-emitting units is completed, and then 1 nm of Yb is vacuum evaporated on the electron transport layer of the last light-emitting unit as an electron injection layer, and then 13 nm of Mg:Ag (1:9, mass ratio) is vacuum evaporated on the electron injection layer as a cathode.

[0321] The performance test of the stacked organic electroluminescent devices provided in the examples and comparative examples was carried out as follows:

[0322] (1) Under the same current density, use a digital source meter and a luminance meter to measure the driving voltage and current efficiency of each stacked organic electroluminescent device. Specifically, increase the voltage at a rate of 0.1V per second and measure the current efficiency when the current density of the stacked organic electroluminescent device reaches 10mA / cm 2 The voltage at this time is the working voltage, and the brightness at this time is measured at the same time. The ratio of brightness to current density is the current efficiency;

[0323] (2) The test method for LT97 life is as follows: at 20mA / cm 2 At a constant current density, measure the time required for the brightness to decay to 97% of the initial brightness;

[0324] For the stacked organic electroluminescent device with two light-emitting units, the test values ​​of the operating voltage, current efficiency, and LT97 life of Comparative Example 1 were recorded as 1. The operating voltage, current efficiency, and LT97 life of each embodiment and other comparative examples were the ratios of their respective test values ​​to the test values ​​of Comparative Example 1 (relative voltage, relative current efficiency). For the stacked organic electroluminescent device with three light-emitting units, the test values ​​of the operating voltage, current efficiency, and LT97 life of Comparative Example 5 were recorded as 1. The operating voltage, current efficiency, and LT97 life of each embodiment and other comparative examples were the ratios of their respective test values ​​to the test values ​​of Comparative Example 5. The test data are shown in Tables 2 and 3.

[0325] In Table 2, “doping (%)” represents the mass of the first doping material HI-2 in the P-CGL, taking the mass of the first host material as 100%; in Table 2, ΔHOMO1 represents the HOMO energy level (HOMO PH ) and the HOMO energy level of the second electron blocking layer (second EBL) material EB The difference (HOMO PH -HOMO EB ); In Table 3, ΔHOMO1 represents the HOMO energy level of the first host material in the first P-CGL (HOMO PH ) and the HOMO of the second EBL EB The difference (HOMO PH -HOMO EB ), ΔHOMO2 represents the HOMO in the second P-CGL PH The HOMO EB The difference.

[0326] Table 2

[0327]

[0328] Table 3

[0329]

[0330] According to the performance test data in Tables 2 and 3, in the stacked organic electroluminescent device provided by the present invention, the materials in the P-CGL and their carrier mobility are designed, and the energy level matching relationship of the materials in the P-CGL and the mutual matching of the LUMO / HOMO energy levels of the functional layers in the P-CGL and the adjacent light-emitting units are optimized. This can significantly improve the hole charge generation ability and hole transport ability of the device, adjust the ability of the light-emitting unit to extract hole electrons from the CGL layer, reduce carrier accumulation, and thus achieve carrier transport balance, thereby improving the luminous efficiency and life of the stacked organic electroluminescent device and effectively reducing the operating voltage.

[0331] Compared with the stacked organic electroluminescent device provided by the present invention, the stacked organic electroluminescent devices of Comparative Examples 1-5 have different degrees of degradation in voltage, efficiency and life. The reason is that: the first host material HT-53 of the P-CGL in Comparative Examples 1-3 and 5 does not match the energy level of the EBL material (EBL1) in the adjacent light-emitting unit located on the cathode side, which increases the voltage and energy consumption of the device and reduces the efficiency and life; although the first host material HTL1 of Comparative Example 4 can better match the energy level, it has a low carrier mobility, resulting in excessive carrier accumulation in the device, reducing the carrier transport performance, increasing the operating voltage, and reducing the efficiency and life, resulting in poor overall device performance.

[0332] The applicant states that while the present invention uses the aforementioned embodiments to illustrate the stacked organic electroluminescent device and display device incorporating the same, the present invention is not limited to the aforementioned process steps, nor does it necessarily rely on the aforementioned process steps for implementation. Persons skilled in the art should understand that any improvements to the present invention, equivalent substitutions for the raw materials used, additions of auxiliary components, and selection of specific methods, etc., fall within the scope of protection and disclosure of the present invention.

Claims

1. A stacked organic electroluminescent device, characterized in that: The stacked organic electroluminescent device includes an anode, a cathode, and at least two light-emitting units disposed between the anode and the cathode, each of the light-emitting units including a light-emitting layer and an electron blocking layer, a charge connection layer is disposed between any two adjacent light-emitting units, the charge connection layer includes a P-type charge generation layer, and the P-type charge generation layer includes a first host material and a first dopant material; The LUMO energy level of the first host material in at least one of the charge connection layers is LUMO PH , the HOMO energy level is HOMO PH ; The LUMO energy level of the first doping material is LUMO PG HOMO PH >LUMO PG ; The LUMO energy level of the electron blocking layer material in the light emitting unit adjacent to the charge connection layer and located near the cathode side is LUMO EB , the HOMO energy level is HOMO EB ;LUMO PH >LUMO EB , 0≤HOMO PH -HOMO EB ≤0.30eV; The carrier mobility of the first host material in at least one of the charge connection layers is ≥1.0×10 -4 cm 2 ·V -1 ·s -1 .

2. The stacked organic electroluminescent device according to claim 1, characterized in that: The LUMO energy level of the first host material in at least one of the charge connection layers is ≥-1.85 eV; Preferably, the HOMO energy level of the first host material in at least one of the charge connection layers is from -4.96 eV to -5.21 eV.

3. The stacked organic electroluminescent device according to claim 1, characterized in that: The thickness of at least one of the P-type charge generation layers is 5-15 nm, preferably 8-12 nm.

4. The stacked organic electroluminescent device according to claim 1, characterized in that: In at least one of the P-type charge generation layers, based on 100% by mass of the first host material, the mass of the first doping material is 1%-20%, preferably 5%-10%.

5. The stacked organic electroluminescent device according to claim 1, characterized in that: The light-emitting unit adjacent to the charge connection layer and located near the cathode further includes a hole transport layer; Preferably, the material of the hole transport layer is the same as the first host material in the charge connection layer.

6. The stacked organic electroluminescent device according to any one of claims 1 to 5, characterized in that: The first host material is independently selected from at least one compound having a structure shown in any one of Formula I, Formula II, Formula III, and Formula IV: In Formula I, X is selected from O, S, CR 1 R 2 NR 3 or SiR 4 R 5 Any of the following; Ar 11 、Ar 12 are each independently selected from any one of substituted phenyl, substituted or unsubstituted C9-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl; and when the Ar 11 Include When Z 1 Selected from O, S, CR A1 R A2 or NR A3 Any of the following; Represents the connecting bond of the group; Ar 13 Any one selected from a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C3-C30 heteroaryl group; R 1 、R 2 、R 3 、R 4 、R 5 、R A1 、R A2 、R A3 are each independently selected from any one of hydrogen, substituted or unsubstituted C1-C20 straight or branched alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C2-C12 alkenyl, substituted or unsubstituted C2-C12 alkynyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl; the R 1 and R 2 、R 4 and R 5 、R A1 and R A2 Each independently is not connected or is connected to form a ring through chemical bonds; R 11 、R 12 、R 13 Each is independently selected from any one of halogen, cyano, substituted or unsubstituted C1-C20 straight or branched alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C2-C12 alkenyl, substituted or unsubstituted C2-C12 alkynyl, substituted or unsubstituted C6-C30 aryl, and substituted or unsubstituted C3-C30 heteroaryl; Ar 11 、Ar 12 、Ar 13 、R 1 、R 2 、R 3 、R 4 、R 5 、R A1 、R A2 、R A3 、R 11 、R 12 、R 13 The substituents are each independently selected from any one or a combination of at least two of halogen, cyano, C1-C10 straight or branched alkyl, C3-C10 cycloalkyl, C2-C10 heterocycloalkyl, C1-C10 alkoxy, C1-C10 alkylthio, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryl, and C3-C30 heteroaryl; k1 and k2 are each independently selected from an integer of 0-3; k3 is selected from an integer of 0-4; In Formula II, R 21 、R 22 、R 23 、R 24 Each is independently selected from any one of substituted or unsubstituted C1-C30 straight-chain branched alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl; the R 21 and R 22 Not connected or connected to form a ring through chemical bonds, the R 23 and R 24 Not connected or connected to form a ring through chemical bonds; R 25 、R 26 Each is independently selected from any one of a substituted or unsubstituted C1-C30 straight or branched alkyl group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C6-C30 aryl group, and a substituted or unsubstituted C3-C30 heteroaryl group; L 21 、L 22 Each is independently selected from any one of a single bond, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted C3-C30 heteroarylene group; R 21 、R 22 、R 23 、R 24 、R 25 、R 26 , L 21 , L 22 The substituents are each independently selected from any one or a combination of at least two of a C1-C20 straight or branched alkyl group, a C3-C20 cycloalkyl group, a C6-C30 arylamino group, a C3-C30 heteroarylamino group, a C6-C30 aryl group, and a C3-C30 heteroaryl group; Cy is selected from any one of substituted or unsubstituted C6-C30 aryl groups and substituted or unsubstituted C3-C30 heteroaryl groups; the substituents in Cy are each independently selected from any one of C3-C20 cycloalkyl groups, C6-C30 arylamino groups, C3-C30 heteroarylamino groups, C6-C30 aryl groups, and C3-C30 heteroaryl groups, or a combination of at least two thereof; n1 and n2 are each independently selected from an integer of 0-4; In formula III, Ar 31 、Ar 32 、Ar 33 Each is independently selected from any one of a substituted or unsubstituted C6-C30 aryl group and a substituted or unsubstituted C3-C30 heteroaryl group; L 31 , L 32 , L 33 , L 34 Each is independently selected from any one of a single bond, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted C3-C30 heteroarylene group; R 31 、R 32 、R 33 、R 34 Each is independently selected from any one of halogen, cyano, nitro, hydroxy, amino, substituted or unsubstituted C1-C20 straight or branched alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C1-C20 alkylsilyl, substituted or unsubstituted C6-C60 arylamino, substituted or unsubstituted C3-C60 heteroarylamino, substituted or unsubstituted C6-C60 aryl, and substituted or unsubstituted C3-C60 heteroaryl; R 35 Any one selected from substituted or unsubstituted C1-C10 straight or branched alkyl, substituted or unsubstituted C3-C20 cycloalkyl; Ar 31 、Ar 32 、Ar 33 、L 31 、L 32 、L 33 、L 34 、R 31 、R 32 、R 33 、R 34 、R 35 The substituents substituted in the above-mentioned group are each independently selected from any one or a combination of at least two of halogen, C1-C20 straight or branched alkyl, C3-C20 cycloalkyl, C2-C20 heterocycloalkyl, C1-C10 alkoxy, carboxyl, nitro, cyano, amino, hydroxyl, thiol, C1-C20 alkylsilyl, C1-C20 alkylamino, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryloxy, C3-C30 heteroaryloxy, C6-C60 aryl, and C3-C60 heteroaryl; s1 and s2 are each independently selected from an integer of 0-3, s3 is selected from an integer of 0-4, and s4 is selected from an integer of 0-5; In Formula IV, L 41 , L 42 Each is independently selected from any one of a single bond, a substituted or unsubstituted C6-C50 arylene group, and a substituted or unsubstituted C3-C30 heteroarylene group; Ar 41 、Ar 42 Each is independently selected from any one of a substituted or unsubstituted C6-C50 aryl group and a substituted or unsubstituted C3-C30 heteroaryl group; R 41 、R 42 Each is independently selected from any one of halogen, C1-C20 straight or branched alkyl, C1-C12 alkoxy, C3-C20 cycloalkyl, C2-C12 alkenyl, C2-C12 alkynyl, carboxyl, cyano, amino, C6-C30 arylamino, C3-C30 heteroarylamino, substituted or unsubstituted C6-C50 aryl, and substituted or unsubstituted C3-C30 heteroaryl; L 41 、L 42 、Ar 41 、Ar 42 、R 41 、R 42 The substituents are each independently selected from any one or a combination of at least two of halogen, C1-C10 straight or branched alkyl, C3-C10 cycloalkyl, C2-C10 alkenyl, C1-C6 alkoxy, C1-C6 alkylthio, carboxyl, cyano, amino, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryl, and C3-C30 heteroaryl; m1 is selected from integers of 0-6, and m2 is selected from integers of 0-7.

7. The stacked organic electroluminescent device according to claim 1, characterized in that: The first doping materials are each independently an electron acceptor compound; Preferably, the first doping materials are each independently selected from any one or a combination of at least two of the following compounds:

8. The stacked organic electroluminescent device according to claim 1, characterized in that: The electron blocking layers in the light-emitting units are made of the same material.

9. The stacked organic electroluminescent device according to claim 1, characterized in that: The charge connection layer further comprises an N-type charge generation layer, wherein the N-type charge generation layer is located near the anode in the charge connection layer; Preferably, the N-type charge generation layer comprises a second host material and a second dopant material; Preferably, the thickness of at least one of the N-type charge generation layers is 5-15 nm, more preferably 9-11 nm.

10. The stacked organic electroluminescent device according to claim 1, characterized in that: At least one of the light-emitting units is independently selected from any one of a blue light-emitting unit, a red light-emitting unit or a green light-emitting unit.

11. The stacked organic electroluminescent device according to claim 1, characterized in that: Each of the light-emitting units further includes a hole blocking layer and / or an electron transport layer; Preferably, with the direction from the anode to the cathode being the first direction, each of the light-emitting units independently comprises a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer and an electron transport layer sequentially arranged along the first direction; Preferably, a hole injection layer is further provided on the side of the anode close to the light-emitting unit; Preferably, an electron injection layer is further provided on a side of the cathode close to the light-emitting unit.

12. A display device, characterized in that: The display device comprises the stacked organic electroluminescent device according to any one of claims 1 to 11.

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