Organic electroluminescence device, display substrate and display device

Abstract

The embodiment of the present disclosure provides an organic electroluminescence device, a display substrate and a display device. The organic electroluminescence device comprises an anode, a first functional layer, a light-emitting layer, a second functional layer, a cathode and a cover layer which are sequentially stacked, wherein the material of the cover layer comprises a compound with a structure as shown in formula (I) or a compound with a structure as shown in formula (II).

Description

Technical Field

[0001] This disclosure relates to, but is not limited to, the field of display technology, and particularly to an organic electroluminescent device, a display substrate, and a display apparatus. Background Technology

[0002] Organic light-emitting devices (OLEDs) are active-matrix light-emitting devices with advantages such as light emission, ultra-thinness, wide viewing angle, high brightness, high contrast, low power consumption, and extremely fast response speed. They have gradually become a promising next-generation display technology. A typical OLED device includes an anode, a cathode, a light-emitting material located between the two electrodes, and a capping layer located on the cathode side away from the anode. The design of the capping layer is crucial for achieving better luminous efficiency and a longer lifespan in OLEDs. Summary of the Invention

[0003] The following is an overview of the subject matter described in detail herein. This overview is not intended to limit the scope of the claims.

[0004] In a first aspect, embodiments of this disclosure provide an organic electroluminescent device, comprising: an anode, a first functional layer, a light-emitting layer, a second functional layer, a cathode, and a capping layer stacked sequentially, wherein the material of the capping layer comprises: a compound with the structure shown in formula (I) or a compound with the structure shown in formula (II);

[0005]

[0006] In formulas (I) and (II), L3, L4, and L5 are each independently selected from any of the following groups: single bond, alkyl group with 2 to 30 substituted or unsubstituted carbon atoms, aryl group with 6 to 20 substituted or unsubstituted carbon atoms, fused aryl group with 6 to 20 substituted or unsubstituted carbon atoms, heteroaryl group with 5 to 20 substituted or unsubstituted carbon atoms; at least one of Ar3 and Ar4 is selected from any of the groups with structures shown in formulas (2-1) to (2-7);

[0007]

[0008] in, The symbol represents a chemical bond; X is selected from CR, NR, oxygen, or sulfur; CR is a carbon atom bonded to hydrogen or an alkyl group; NR is a nitrogen atom bonded to hydrogen or an alkyl group; Y, Y1, Y2, Y3, and Y4 are each independently CR or nitrogen, and only one of Y1 to Y4 is nitrogen; Z is CR or NR; R is selected from any of the following: hydrogen, deuterium, alkyl group with 2 to 30 carbon atoms, aryl group with 6 to 20 carbon atoms, heteroaryl group with 5 to 20 carbon atoms; Ar is selected from a group containing only one heteroatom, which is nitrogen, oxygen, or sulfur.

[0009] Secondly, embodiments of this disclosure provide a display substrate, including: a substrate and a plurality of light-emitting devices disposed on one side of the substrate, wherein at least one of the plurality of light-emitting devices is an organic electroluminescent device as described in the exemplary embodiments above.

[0010] Thirdly, embodiments of this disclosure provide a display device, including: the display substrate described in the exemplary embodiments above.

[0011] The organic electroluminescent device, display substrate, and display device provided in this disclosure effectively improve the refractive index of the capping layer and the hole mobility in the film layer region between the anode and the light-emitting layer, thereby effectively improving the luminous efficiency and lifetime of the entire organic electroluminescent device.

[0012] Other features and advantages of this disclosure will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the disclosure. Other advantages of this disclosure may be realized and obtained by means of the embodiments described in the description and the accompanying drawings.

[0013] After reading and understanding the accompanying diagrams and detailed descriptions, the other aspects can be understood. Attached Figure Description

[0014] The accompanying drawings are provided to illustrate the technical solutions of this disclosure and form part of the specification. They are used together with the embodiments of this disclosure to explain the technical solutions of this disclosure and do not constitute a limitation on the technical solutions of this disclosure. The shapes and sizes of the components in the drawings do not reflect actual proportions and are only intended to illustrate the content of this disclosure.

[0015] Figure 1 This is a schematic diagram of the structure of an OLED display device;

[0016] Figure 2 This is a schematic diagram of the planar structure of the display area of ​​a display substrate;

[0017] Figure 3 This is a schematic diagram of a cross-sectional structure of a display substrate;

[0018] Figure 4This is a schematic diagram of the structure of an organic electroluminescent device according to an exemplary embodiment of the present disclosure;

[0019] Figure 5 This is a schematic diagram of the structure of another organic electroluminescent device in an exemplary embodiment of this disclosure.

[0020] Explanation of reference numerals in the attached figures:

[0021] 101—Substrate; 102—Driving circuit layer; 103—Light-emitting structure layer;

[0022] 104—Packaging structure layer; 210—Transistor; 211—Storage capacitor;

[0023] 302—Pixel definition layer; 303—Organic light-emitting layer; 401—First encapsulation layer.

[0024] 402—Second encapsulation layer; 403—Third encapsulation layer; 501—Anode;

[0025] 502—First functional layer; 503—Emitting layer; 504—Second functional layer;

[0026] 505—Cathode; 506—Capping layer; 601—Hole injection layer;

[0027] 602—Hole transport layer; 603—Assisted emission layer; 604—Hole blocking layer;

[0028] 605—Electron transport layer; 606—Electron injection layer. Detailed Implementation

[0029] This disclosure describes several embodiments, but these descriptions are exemplary and not limiting, and it will be apparent to those skilled in the art that many more embodiments and implementations are possible within the scope of the embodiments described herein. Although many possible combinations of features are shown in the drawings and discussed in exemplary embodiments, many other combinations of the disclosed features are also possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with any other feature or element of any other embodiment, or may substitute for any other feature or element of any other embodiment.

[0030] The scale of the figures in this disclosure can be used as a reference in actual manufacturing processes, but is not limited thereto. For example, the aspect ratio of the channel, the thickness and spacing of each film layer, and the width and spacing of each signal line can be adjusted according to actual needs. The number of pixels in the display substrate and the number of sub-pixels in each pixel are not limited to the quantities shown in the figures. The figures described in this disclosure are only schematic diagrams of the structure, and one aspect of this disclosure is not limited to the shapes or values ​​shown in the figures.

[0031] In the exemplary embodiments disclosed herein, ordinal numbers such as "first," "second," or "third," and similar terms, are used to avoid confusion among constituent elements, rather than to limit in terms of quantity, order, or importance. They should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include at least one of those features.

[0032] In the exemplary embodiments of this disclosure, for convenience, terms such as "center," "middle," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," or "circumferential" are used to describe the positional relationships of the constituent elements with reference to the accompanying drawings. This is solely for the purpose of facilitating the description of this disclosure and simplifying the description, and is not intended to indicate or imply that the device or element referred to has a specific orientation, or is constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this disclosure. The positional relationships of the constituent elements may be appropriately varied depending on the direction in which each constituent element is described. Therefore, the description is not limited to the terms used in the specification and may be appropriately replaced as appropriate.

[0033] In the exemplary embodiments disclosed herein, unless otherwise expressly specified and limited, the terms "installed," "connected," "linked," or "fixed," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or the internal communication of two components or the interaction between two components. Those skilled in the art will understand the meaning of the above terms in this disclosure based on the actual situation.

[0034] In the embodiments of this disclosure, a transistor refers to a device that includes at least three terminals: a gate electrode (also referred to as the gate or control electrode), a drain electrode (also referred to as the drain terminal, drain region, or drain electrode), and a source electrode (also referred to as the source terminal, source region, or source electrode). The transistor has a channel region between the drain electrode and the source electrode, and current can flow through the drain electrode, the channel region, and the source electrode. Note that in this specification, the channel region refers to the region through which current primarily flows.

[0035] In the embodiments of this disclosure, to distinguish the two terminals of a transistor other than the control terminal, one terminal is directly described as the first terminal and the other as the second terminal. The first terminal can be the drain electrode and the second terminal can be the source electrode, or vice versa. In cases where transistors with opposite polarities are used or where the current direction changes during circuit operation, the functions of the "source electrode" and "drain electrode" are sometimes interchanged. Therefore, in this specification, the "source electrode" and "drain electrode" can be interchanged.

[0036] The transistors used in this disclosure can all be thin-film transistors (TFTs), field-effect transistors (FETs), or other devices with similar characteristics. For example, the thin-film transistors used in this disclosure can include, but are not limited to, oxide TFTs or low-temperature polysilicon TFTs (LTPS TFTs). For example, the thin-film transistor can be a bottom-gate structure thin-film transistor or a top-gate structure thin-film transistor, as long as it can achieve the switching function. Here, this disclosure does not limit this aspect.

[0037] In the embodiments of this disclosure, the term "about" refers to a value that is not strictly limited and is within the range of process and measurement errors.

[0038] In the embodiments of this disclosure, the term "sequentially stacked" may refer to multiple film layers being stacked in one direction, but does not necessarily mean that these film layers are necessarily bonded together in pairs.

[0039] In the embodiments of this disclosure, the expressions "on," "formed on," "set on," or similar expressions can indicate that one layer is directly formed or set on another layer, or that one layer is indirectly formed or set on another layer, meaning that there are other layers between the two layers. Furthermore, "above," "over," and "on top" of the first feature and the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" of the first feature and the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature. In this document, unless otherwise stated, the term "located in the same layer" means that two layers, components, members, elements, or portions can be formed by the same patterning process, and that these two layers, components, members, elements, or portions are generally formed of the same material. In this document, unless otherwise stated, the expression "patterning process" generally includes steps such as photoresist coating, exposure, development, etching, and photoresist stripping. The expression "one-time patterning process" refers to a process of forming patterned layers, components, members, etc., using a single photomask.

[0040] In this embodiment of the disclosure, "thickness" refers to the height of the surface away from the substrate from the surface near the substrate in a plane perpendicular to the substrate.

[0041] The embodiments will now be described with reference to the accompanying drawings. These embodiments can be implemented in several different forms. Those skilled in the art will readily understand that the methods and content can be varied in different forms without departing from the spirit and scope of this disclosure. Therefore, this disclosure should not be construed as being limited to the content described in the following embodiments.

[0042] To keep the following description of the embodiments of this disclosure clear and concise, detailed descriptions of some known functions and components have been omitted. The accompanying drawings of the embodiments of this disclosure only relate to the structures involved in the embodiments of this disclosure; other structures can be referred to in general design.

[0043] Figure 1 This is a schematic diagram of the structure of a display device. Figure 1As shown, the display device may include a timing controller, a data driver, a scan driver, a light-emitting driver, and a pixel array. The timing controller is connected to the data driver, the scan driver, and the light-emitting driver. The data driver is connected to multiple data signal lines (D1 to Dn), the scan driver is connected to multiple scan signal lines (S1 to Sm), and the light-emitting driver is connected to multiple light-emitting signal lines (E1 to Eo). The pixel array may include multiple sub-pixels Pxij, where i and j can be natural numbers. At least one sub-pixel Pxij may include a circuit unit and a light-emitting device connected to the circuit unit. The circuit unit may include a pixel driving circuit, which may be connected to the scan signal lines, the light-emitting signal lines, and the data signal lines. In some exemplary embodiments, the timing controller may provide grayscale values ​​and control signals of specifications suitable for the data driver to the data driver, provide clock signals, scan start signals, etc. of specifications suitable for the scan driver to the scan driver, and provide clock signals, transmit stop signals, etc. of specifications suitable for the light-emitting driver to the light-emitting driver. The data driver can use grayscale values ​​and control signals received from the timing controller to generate data voltages to be provided to data signal lines D1, D2, D3, ..., Dn. For example, the data driver can sample grayscale values ​​using a clock signal and apply data voltages corresponding to the grayscale values ​​to data signal lines D1 to Dn in pixel rows, where n can be a natural number. The scan driver can generate scan signals to be provided to scan signal lines S1, S2, S3, ..., Sm by receiving clock signals, scan start signals, etc., from the timing controller. For example, the scan driver can sequentially provide scan signals with on-level pulses to scan signal lines S1 to Sm. For example, the scan driver can be configured as a shift register and can generate scan signals by sequentially transmitting scan start signals in the form of on-level pulses to the next stage circuit under the control of a clock signal, where m can be a natural number. The light-emitting driver can generate transmit signals to be provided to light-emitting signal lines E1, E2, E3, ..., Eo by receiving clock signals, transmit stop signals, etc., from the timing controller. For example, an LED driver can sequentially provide transmit signals with cutoff level pulses to LED signal lines E1 to Eo. For example, the LED driver can be configured as a shift register and can generate transmit signals by sequentially transmitting transmit stop signals in the form of cutoff level pulses to the next stage circuit under the control of a clock signal, where o can be a natural number.

[0044] Figure 2 This is a schematic diagram of a planar structure of a display substrate. Figure 2As shown, the display substrate may include multiple pixel units P arranged in a regular pattern (e.g., in a matrix). At least one pixel unit P may include a first sub-pixel P1 emitting a first color light, a second sub-pixel P2 emitting a second color light, and a third sub-pixel P3 emitting a third color light. Each sub-pixel may include a circuit unit and a light-emitting device connected to the circuit unit. The circuit unit may include a pixel driving circuit and scan signal lines, data signal lines, and light-emitting signal lines connected to the pixel driving circuit. The pixel driving circuit is configured to receive the data voltage transmitted by the data signal line and output a corresponding current to the light-emitting device under the control of the scan signal line and the light-emitting signal line. The light-emitting device in each sub-pixel is connected to the pixel driving circuit of its respective sub-pixel, and the light-emitting device is configured to emit light of a corresponding brightness in response to the current output by the pixel driving circuit of its respective sub-pixel.

[0045] In some exemplary embodiments, a pixel unit P may include red, green, and blue sub-pixels, or it may include red, green, blue, and white sub-pixels; this disclosure does not limit the scope of the invention. In some exemplary embodiments, the shape of the sub-pixels in a pixel unit may be rectangular, rhomboid, pentagonal, or hexagonal, etc. In some exemplary embodiments, when a pixel unit includes three sub-pixels, the three sub-pixels may be arranged horizontally side-by-side, vertically side-by-side, or in a triangular arrangement. In other exemplary embodiments, when a pixel unit includes four sub-pixels, the four sub-pixels may be arranged horizontally side-by-side, vertically side-by-side, or in a square arrangement; this disclosure does not limit the scope of the invention.

[0046] Figure 3 This is a cross-sectional structural diagram of a display substrate, illustrating the structure of three sub-pixels in an OLED display substrate. Figure 3 As shown, on a plane perpendicular to the display substrate, the display substrate may include a driving circuit layer 102 disposed on the substrate 101, a light-emitting structure layer 103 disposed on the side of the driving circuit layer 102 away from the substrate 101, and an encapsulation structure layer 104 disposed on the side of the light-emitting structure layer 103 away from the substrate 101. In some possible implementations, the display substrate may include other film layers, such as a touch structure layer, etc., which are not limited herein.

[0047] In some exemplary embodiments, the substrate 101 may be a flexible substrate or a rigid substrate.

[0048] In some exemplary embodiments, the driving circuit layer 102 for each sub-pixel may include a plurality of transistors and a storage capacitor constituting a pixel driving circuit. Figure 3The example only uses one transistor 210 and one storage capacitor 211. In some exemplary embodiments, the light-emitting structure layer 103 may include an anode 501, a pixel definition layer 302, an organic light-emitting layer 303, and a cathode 505. The anode 501 is connected to the drain electrode of the driving transistor 210 through a via. The pixel definition layer 302 is provided with a pixel opening that exposes the anode 501. The organic light-emitting layer 303 is connected to the anode 501, and the cathode 505 is connected to the organic light-emitting layer 303. The organic light-emitting layer 303 emits light of the corresponding color under the drive of the anode 501 and the cathode 505.

[0049] In some exemplary embodiments, the organic light-emitting layer 303 may include an emitting layer (EML) and any one or more of the following: a hole injection layer (HIL), a hole transport layer (HTL), an electron block layer (EBL), a hole block layer (HBL), an electron transport layer (ETL), and an electron injection layer (EIL). The emitting layer is configured to emit light by recombination of electrons and holes. The hole injection layer is configured to lower the potential barrier for injecting holes from the anode, allowing holes to be effectively injected from the anode into the emitting layer. The hole transport layer is configured to enable the directional and orderly controllable migration of injected holes. The electron block layer is configured to form a migration barrier for electrons, preventing electrons from migrating out of the emitting layer. The hole block layer is configured to form a migration barrier for holes, preventing holes from migrating out of the emitting layer. The electron transport layer is configured to enable the directional and orderly controlled migration of injected electrons. The electron injection layer is configured to lower the potential barrier for electrons injected from the cathode, allowing electrons to be efficiently injected from the cathode into the light-emitting layer. In some exemplary embodiments, one or more of the hole injection layer, hole transport layer, electron blocking layer, hole blocking layer, electron transport layer, and electron injection layer of all sub-pixels may be common layers connected together, and the light-emitting layers of adjacent sub-pixels may have a small overlap or may be isolated.

[0050] In some exemplary embodiments, the encapsulation structure layer 104 may include a first encapsulation layer 401, a second encapsulation layer 402, and a third encapsulation layer 403 stacked together. For example, the first encapsulation layer 401 and the third encapsulation layer 403 may be made of inorganic materials, while the second encapsulation layer 402 may be made of organic materials. The second encapsulation layer 402 is disposed between the first encapsulation layer 401 and the third encapsulation layer 403 to ensure that external moisture cannot enter the light-emitting structure layer 103.

[0051] In some exemplary embodiments, the pixel driving circuit may employ a pixel circuit with an nTmC (n and m are positive integers) structure, such as 2T1C (i.e., two transistors and one capacitor), 3T1C, 4T1C, 5T1C, 5T2C, 6T1C, 7T1C, or 8T1C. In different exemplary embodiments, the pixel circuit may further include a compensation sub-circuit, which may include an internal or external compensation sub-circuit, and may include transistors, capacitors, etc. For example, as needed, the pixel circuit may also include a reset sub-circuit, a light emission control sub-circuit, etc. This disclosure does not limit this aspect.

[0052] Many OLED structures employ a top-emitting device structure, using a reflective anode and a transparent cathode to enhance light extraction efficiency through the microcavity effect. In such devices, a crucial layer is the capping layer (CPL), also known as the light extraction layer. The capping layer typically uses a high-refractive-index organic or inorganic transparent material with virtually no absorption range in the visible light spectrum. Light-emitting devices with a capping layer can improve the light extraction mode. The high refractive index of the capping layer, positioned above the cathode, creates a high-low refractive index combination, allowing light that would otherwise be confined inside the device to exit, resulting in higher light extraction efficiency and better light emission. The higher the refractive index of the capping layer material, the more pronounced the light extraction effect and the better the device performance. However, in some technologies, the capping layer material has a low refractive index (e.g., 2.0 at 460nm wavelength), which has a smaller impact on improving light extraction and device efficiency.

[0053] This exemplary embodiment provides an organic electroluminescent device that effectively improves the refractive index of the capping layer (CPL) by introducing cycloalkylnaphthalene groups, and can improve the hole mobility in the film region between the anode and the light-emitting layer, thereby effectively improving the luminous efficiency and lifetime of the entire organic electroluminescent device.

[0054] In some exemplary embodiments, the organic light-emitting device may be a blue organic light-emitting device, a red organic light-emitting device, or a green organic light-emitting device.

[0055] An exemplary embodiment of this disclosure provides an organic electroluminescent device. Figure 4 This is a schematic diagram of the structure of an organic electroluminescent device according to an exemplary embodiment of this disclosure. Figure 4 As shown, an organic electroluminescent device may include: an anode 501, a first functional layer 502, a light-emitting layer 503, a second functional layer 504, a cathode 505, and a capping layer (CPL) 506 stacked sequentially, wherein the material of the capping layer (CPL) 506 may include: a compound with the structure shown in Formula (I) or a compound with the structure shown in Formula (II).

[0056]

[0057] In formulas (I) and (II), L3, L4, and L5 are each independently selected from any of the following groups: single bond, alkyl group with 2 to 30 substituted or unsubstituted carbon atoms, aryl group with 6 to 20 substituted or unsubstituted carbon atoms, fused aryl group with 6 to 20 substituted or unsubstituted carbon atoms, heteroaryl group with 5 to 20 substituted or unsubstituted carbon atoms; at least one of Ar3 and Ar4 is selected from any of the groups with structures shown in formulas (2-1) to (2-7);

[0058]

[0059] in, Indicates a chemical bond; X is selected from CR, NR, oxygen (O), or sulfur (S); CR is a carbon atom bonded to hydrogen or an alkyl group; NR is a nitrogen atom bonded to hydrogen or an alkyl group; Y, Y1, Y2, Y3, and Y4 are each independently CR or nitrogen (N), and only one of Y1 to Y4 is N; Z is CR or NR; R is selected from any of the following: hydrogen, deuterium (D), alkyl group with 2 to 30 carbon atoms, aryl group with 6 to 20 carbon atoms, and heteroaryl group with 5 to 20 carbon atoms. Ar is selected from a group containing only one heteroatom, which is nitrogen (N), oxygen (O), or sulfur (S).

[0060] Thus, in the organic electroluminescent device provided in the exemplary embodiments of this disclosure, by introducing cycloalkylnaphthalene groups into the capping layer material, the refractive index of the capping layer (CPL) can be increased. Furthermore, since the capping layer material has a strong electron-donating ability, the hole mobility in the film layer region between the anode and the light-emitting layer can be increased. Moreover, the increased molecular weight relative to naphthalene improves the device lifetime, thereby improving the luminous efficiency and lifetime of the entire organic electroluminescent device, and realizing a high-efficiency, long-life OLED device.

[0061] In some exemplary embodiments, L3 and L4 may be the same or different.

[0062] In some exemplary embodiments, X is oxygen (O) or sulfur (S).

[0063] In some exemplary embodiments, Ar3 and Ar4, which are not selected from the structures shown in formulas (2-1) to (2-7), are selected from any of the following groups: alkyl groups with 2 to 20 substituted or unsubstituted carbon atoms, aryl groups with 6 to 20 substituted or unsubstituted carbon atoms, and heteroaryl groups with 5 to 20 substituted or unsubstituted carbon atoms containing one or more heteroatoms; wherein the heteroatoms are nitrogen, oxygen, or sulfur.

[0064] In some other exemplary embodiments, Ar3 and Ar4 contain any group not selected from the structures shown in formulas (2-1) to (2-7), but selected from the structures shown in formulas (2-8) to (2-10):

[0065]

[0066] In some exemplary embodiments, the material of the capping layer is selected from any of the compounds with structures shown in formulas (3-1) to (3-53):

[0067]

[0068]

[0069]

[0070]

[0071]

[0072]

[0073] In this disclosure, compounds with the structure shown in formula (3-1) are referred to as compound 1, and similarly, compounds with the structure shown in formula (3-2) are referred to as compound 2, compounds with the structure shown in formula (3-3) are referred to as compound 3, ..., compounds with the structure shown in formula (3-53) are referred to as compound 53, and so on.

[0074] In some exemplary embodiments, the first functional layer located between the light-emitting layer 503 and the anode 501 may include multiple organic layers. At least two layers of the multiple organic layers may contain aromatic amine groups, and at least one layer may contain cycloalkylnaphthalene groups. For example, the first functional layer may include one or more of a hole injection layer 601, a hole transport layer 602, and an auxiliary light-emitting layer (AEML) 603. The hole injection layer 601 is configured to lower the potential barrier for holes injected from the anode, enabling holes to be effectively injected from the anode into the light-emitting layer 503. The hole transport layer 602 is configured to achieve controlled, directional migration of injected holes. The auxiliary light-emitting layer (AEML) 603 is configured to have the same function as the electron blocking layer (EBL) (e.g., to form a migration barrier for electrons, preventing electrons from migrating out of the light-emitting layer (EML) 503), and can share the same chamber and fine metal mask (FMM mask) with the light-emitting layer (EML) 503, reducing fabrication costs and difficulty. The auxiliary light-emitting layer (AEML) 603 can also be configured to reduce the potential barrier between the hole transport layer and the host material in the light-emitting layer (EML) 503, efficiently migrating holes to the light-emitting layer (EML) 503 to recombine with electrons to form excitons, thereby improving luminescence efficiency.

[0075] In some exemplary embodiments, such as Figure 5 As shown, the first functional layer may include: a hole injection layer 601 disposed on the anode side, a hole transport layer 602 disposed on the side of the hole injection layer 601 away from the anode, and an auxiliary light-emitting layer (AEML) 603 disposed on the side of the hole transport layer 602 away from the hole transport layer 602. At least two of the hole injection layer 601, hole transport layer 602, and auxiliary light-emitting layer 603 may contain aromatic amine groups, and at least one of the hole injection layer 601, hole transport layer 602, and auxiliary light-emitting layer 603 may contain cycloalkylnaphthalene groups. For example, multiple layers of the hole injection layer 601, hole transport layer 602, and auxiliary light-emitting layer 603 may contain both aromatic amine groups and cycloalkylnaphthalene groups. This increases the hole transport rate of the first functional layer located between the light-emitting layer 503 and the anode 501, and since the photoluminescence (PL) spectrum of the aromatic amine material is in the range of 400 nm to 450 nm, it is beneficial to improve device efficiency.

[0076] In some exemplary embodiments, the first functional layer located between the light-emitting layer 503 and the anode 501 may include multiple organic layers, wherein at least one of the multiple organic layers may be made of any one of the compounds with the structure shown in formulas (4-1) to (4-3).

[0077]

[0078] In some exemplary embodiments, the material of one or more layers of the hole injection layer 601, hole transport layer 602, auxiliary light emission layer (AEML) 603, etc., can be selected from any of the compounds with structures shown in formulas (4-1) to (4-3).

[0079] In some exemplary embodiments, such as Figure 5 As shown, the first functional layer may include a hole injection layer 601 disposed on the anode side and a hole transport layer 602 disposed on the side of the hole injection layer 601 away from the anode, wherein the hole injection layer comprises the same material as the hole transport layer. For example, the materials of both the hole injection layer 601 and the hole transport layer 602 include aromatic amine groups, and at least one of the hole injection layer 601 and the hole transport layer 602 comprises cycloalkylnaphthalene groups. Thus, in the organic electroluminescent device provided in the exemplary embodiments of this disclosure, since the materials used in the hole injection layer and the hole transport layer have relatively fast mobility and more matched energy levels, the voltage can be reduced and the efficiency improved. Furthermore, the material used in the capping layer has high refractive index and high thermal stability, thereby enabling high-performance devices.

[0080] In some exemplary embodiments, such as Figure 5 As shown, the second functional layer may include one or more of the following: a hole blocking layer 604, an electron transport layer 605, and an electron injection layer 606. The hole blocking layer 604 is configured to form a migration barrier for holes, preventing them from migrating out of the light-emitting layer. The electron transport layer 605 is configured to enable the directional and orderly controllable migration of injected electrons. The electron injection layer 606 is configured to lower the barrier for injecting electrons from the cathode, allowing electrons to be effectively injected from the cathode into the light-emitting layer.

[0081] In some exemplary embodiments, the first functional layer 502 may include multiple organic layers, and the material of at least one of the multiple organic layers may include a compound with the structure shown in formula (III);

[0082]

[0083] In formula (III), G1 and R are each independently selected from any of the following groups: hydrogen (H), deuterium (D), aryl with 6 to 12 substituted or unsubstituted carbon atoms; L1 and L2 are each independently selected from any of the following groups: direct bond, aryl with 6 to 24 substituted or unsubstituted carbon atoms, heteroaryl with 5 to 20 substituted or unsubstituted carbon atoms; Ar1 ​​and Ar2 are each independently selected from any of the following groups: aryl with 6 to 30 substituted or unsubstituted carbon atoms, heteroaryl with 5 to 30 substituted or unsubstituted carbon atoms; (D)m represents a group with m deuterium (D) atoms, (D)n represents a group with n deuterium (D) atoms, where m and n are integers from 0 to 4; (D)o represents a group with o deuterium (D) atoms, where o is an integer from 0 to 8; p is an integer from 0 to 2. Thus, by introducing cycloalkylnaphthalene groups and aromatic amine groups into at least one layer of the first functional layer located between the light-emitting layer and the anode, the strong electron-donating ability of the cycloalkylnaphthalene groups increases the electron cloud density, thereby improving hole mobility. Furthermore, the increased molecular weight relative to naphthalene enhances the material's thermal stability. Additionally, the photoluminescence (PL) spectrum of aromatic amine materials, ranging from 400 nm to 450 nm, is beneficial for improving device efficiency. This leads to an improvement in the overall luminous efficiency and lifetime of the organic electroluminescent device.

[0084] In some exemplary embodiments, the material of one or more layers of the hole injection layer 601, hole transport layer 602, auxiliary light-emitting layer (AEML) 603, etc., may include a compound with the structure shown in Formula (III). Thus, by introducing cycloalkylnaphthalene groups and aromatic amine groups into at least one of the hole injection layer, hole transport layer, and auxiliary light-emitting layer, the strong electron-donating ability of the cycloalkylnaphthalene groups increases the electron cloud density, thereby improving the hole mobility of at least one of the hole injection layer, hole transport layer, and auxiliary light-emitting layer. Furthermore, the increased molecular weight relative to naphthalene enhances the thermal stability of the material, thereby improving the luminous efficiency and lifetime of the entire organic electroluminescent device. Additionally, the photoluminescence (PL) spectrum of the aromatic amine material is in the range of 400 nm to 450 nm, which is beneficial for improving device efficiency. For example, the material of the hole injection layer may include a compound with the structure shown in Formula (III), or the material of the hole transport layer may include a compound with the structure shown in Formula (III). In this way, the hole mobility of the hole transport layer can be improved, and the device efficiency and lifetime can be improved. Alternatively, the materials of the hole injection layer and the hole transport layer may include a compound with the structure shown in Formula (III), or the materials of the hole injection layer, the hole transport layer and the auxiliary light-emitting layer may include a compound with the structure shown in Formula (III), etc.

[0085] In some exemplary embodiments, G1 and R may be the same or different. L1 and L2 may be the same or different. Ar1 and Ar2 may be the same or different.

[0086] In some exemplary embodiments, in equation (III) Choose any one of the structures shown in equations (a1) to (a32):

[0087]

[0088] In some exemplary embodiments, the structures shown in equations (a1) to (a32) may be partially or completely deuterated.

[0089] In some exemplary embodiments, the material of at least one layer of the first functional layer located between the light-emitting layer 503 and the anode 501 (such as at least one layer of a hole injection layer, a hole transport layer, and an auxiliary light-emitting layer) can be selected from any of the compounds with structures shown in Formulas 1 to 249. Thus, by introducing aromatic amine groups and cycloalkylnaphthalene groups into at least one layer of the first functional layer located between the light-emitting layer and the anode, the photoluminescence (PL) spectrum of the aromatic amine material is in the range of 400 nm to 450 nm, which is beneficial for improving device efficiency. Furthermore, since the cycloalkylnaphthalene group has a strong electron-donating ability, it can increase the electron cloud density, thereby improving the hole mobility and hole transport rate of the first functional layer located between the light-emitting layer and the anode. Moreover, the increased molecular weight relative to naphthalene can improve the thermal stability of the material.

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097]

[0098]

[0099]

[0100]

[0101]

[0102]

[0103]

[0104] In some exemplary embodiments, compounds with structures shown in Formulas 1 to 249 may be partially or fully deuterated.

[0105] In this disclosure, compounds with the structure shown in Formula 1 are designated as compound 1A, similarly, compounds with the structure shown in Formula 2 are designated as compound 2A, compounds with the structure shown in Formula 3 are designated as compound 3A, ..., compounds with the structure shown in Formula 249 are designated as compound 249A, and so on.

[0106] In some exemplary embodiments, the anode can be made of a material with a high work function. For bottom-emitting OLEDs, the anode can be a transparent oxide material, such as indium tin oxide (ITO) or indium zinc oxide (IZO), and the anode thickness can be approximately 80 nm to 200 nm. For top-emitting OLEDs, the anode can be a composite structure of metal and transparent oxide, such as Ag / ITO, Ag / IZO, or ITO / Ag / ITO, etc., where the thickness of the metal layer in the anode can be approximately 80 nm to 100 nm, and the thickness of the transparent oxide in the anode can be approximately 5 nm to 20 nm, resulting in an average reflectance of approximately 85% to 95% in the visible light region.

[0107] In some exemplary embodiments, for bottom-emitting OLEDs, the cathode can be made of magnesium (Mg), silver (Ag), aluminum (Al), or a Mg:Ag alloy, and the thickness of the cathode can be approximately greater than 80 nm, giving the cathode good reflectivity. For top-emitting OLEDs, the cathode can be made of a metallic material formed by a vapor deposition process. The metallic material can be magnesium (Mg), silver (Ag), or aluminum (Al), or an alloy material, such as a Mg:Ag alloy, with a Mg:Ag ratio of approximately 3:7 to 1:9. The thickness of the cathode can be approximately 10 nm to 20 nm, giving the cathode an average transmittance of approximately 50% to 60% at a wavelength of 530 nm.

[0108] In some exemplary embodiments, the light-emitting layer may include a host light-emitting material and a guest light-emitting material. The host light-emitting material may be a bipolar mono-host material or a dual-host material formed by blending hole-type and electron-type hosts. The guest light-emitting material may be a phosphorescent material, a fluorescent material, a delayed fluorescence material, etc., and the doping ratio of the guest light-emitting material is approximately 2% to 12%. For example, the doping ratio of the blue guest material BD in the blue light-emitting layer is approximately 3%.

[0109] In some exemplary embodiments, the electron transport layer may be prepared by blending thiophene, imidazole or azazine derivatives with quinoline lithium, wherein the doping ratio of quinoline lithium in the electron transport layer is about 30% to 70%, and the thickness of the electron transport layer may be about 20 nm to 70 nm.

[0110] In some exemplary embodiments, the electron injection layer may be formed by a vapor deposition process using materials such as lithium fluoride (LiF), lithium 8-hydroxyquinoline (LiQ), ytterbium (Yb), or calcium (Ca), and the thickness of the electron injection layer may be approximately 0.5 nm to 2 nm.

[0111] In some exemplary embodiments, for top-emitting OLEDs, the thickness of the film layer (such as the first functional layer, the light-emitting layer, and the second functional layer) between the anode and the cathode can be designed to meet the optical path requirements of the optical micro-resonator in order to obtain optimal light intensity and color.

[0112] In the exemplary embodiments of this disclosure, the descriptions “...each independently is” and “...each independently is selected from” are interchangeable and should be interpreted broadly. They can mean that the example options expressed by the same symbol in different groups do not affect each other, or that the example options expressed by the same symbol in the same group do not affect each other.

[0113] In exemplary embodiments of this disclosure, the number of carbon atoms in L1, L2, L3, L4, L5, Ar1, Ar2, Ar3, and Ar4 refers to the total number of carbon atoms. For example, when L3 is selected from a substituted arylene group having 6 carbon atoms, the total number of carbon atoms in the arylene group and its substituents is 12.

[0114] In exemplary embodiments of this disclosure, unless otherwise specifically defined, "heteroatom" can refer to a functional group comprising at least one heteroatom such as boron (B), nitrogen (N), oxygen (O), sulfur (S), selenium (Se), silicon (Si), or phosphorus (P), with the remaining atoms being carbon (C) and hydrogen (H). An unsubstituted alkyl group can be a "saturated alkyl group" without any double or triple bonds.

[0115] In exemplary embodiments of this disclosure, "alkyl" may include straight-chain alkyl or branched alkyl. Depending on the specific case, an alkyl group may have 2 to 30 carbon atoms, or, for example, 2 to 20 carbon atoms. In exemplary embodiments of this disclosure, numerical ranges such as "2 to 20" refer to integers within a given range; for example, "alkyl with 2 to 20 carbon atoms" may refer to an alkyl group containing 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 carbon atoms. Furthermore, the alkyl group may be substituted or unsubstituted.

[0116] In exemplary embodiments of this disclosure, aryl refers to any optional functional group or substituent derived from an aromatic carbon ring. The aryl group can be a monocyclic aryl (e.g., phenyl) or a polycyclic aryl. For example, the aryl group can be a monocyclic aryl, a fused-ring aryl, two or more monocyclic aryl groups conjugated by carbon-carbon bonds, a monocyclic aryl and a fused-ring aryl group conjugated by carbon-carbon bonds, or two or more fused-ring aryl groups conjugated by carbon-carbon bonds. That is, unless otherwise stated, two or more aromatic groups conjugated by carbon-carbon bonds can also be considered as aryl groups in this disclosure. A fused-ring aryl refers to a molecule containing at least two aromatic rings, where the aromatic rings are not independent but share two adjacent carbon atoms fused together. For example, fused-ring aryl can include: bicyclic fused aryl (e.g., naphthyl), tricyclic fused aryl (e.g., phenanthrene, fluorene, anthracene), etc. The aryl group does not contain heteroatoms such as B, N, O, S, P, Se, and Si. For example, in this disclosure, biphenyl, terphenyl, etc. are aryl groups. Aryl groups may include, but are not limited to: phenyl, naphthyl, fluorenyl, anthracene, phenanthryl, biphenyl, terphenyl, tetraphenyl, pentaphenyl, benzo[9,10]phenanthryl, pyrene, benzofluoranthracene, etc.

[0117] In exemplary embodiments of this disclosure, the described "aryl" may contain 6 to 20 carbon atoms. In some exemplary embodiments, the number of carbon atoms in the aryl group may be 6 to 19; in other exemplary embodiments, the number of carbon atoms in the aryl group may be 6 to 14; and in still other exemplary embodiments, the number of carbon atoms in the aryl group may be 6 to 8. For example, in this disclosure, the number of carbon atoms in the aryl group may be 6, 10, 12, 13, 14, 15, 18, 20, etc. Of course, the number of carbon atoms may also be other numbers, which will not be listed here. In this disclosure, biphenyl can be understood as a phenyl-substituted aryl group or an unsubstituted aryl group.

[0118] In exemplary embodiments of this disclosure, arylene can refer to a divalent group formed by the loss of a hydrogen atom from an aryl group.

[0119] In exemplary embodiments of this disclosure, the substituted aryl group may be one or more hydrogen atoms of the aryl group that are replaced by groups such as deuterium atoms, halogen groups, cyano groups, aryl groups, heteroaryl groups, alkyl groups, cycloalkyl groups, etc. For example, heteroaryl-substituted aryl groups may include, but are not limited to, dibenzofuranyl-substituted phenyl groups, dibenzothiophene-substituted phenyl groups, pyridine-substituted phenyl groups, etc. The number of carbon atoms in the substituted aryl group refers to the total number of carbon atoms of the aryl group and the substituents on the aryl group. For example, a substituted aryl group with 18 carbon atoms means that the total number of carbon atoms of the aryl group and its substituents is 18. For example, aryl groups that are substituents may include, but are not limited to, phenyl, naphthyl, biphenyl, etc.

[0120] In exemplary embodiments of this disclosure, a heteroaryl group refers to a monovalent aromatic ring or a derivative thereof containing at least one heteroatom, where the heteroatom can be at least one of B, O, N, P, Si, Se, and S. The heteroaryl group can be a monocyclic or polycyclic heteroaryl group. For example, a heteroaryl group can be a single aromatic ring system or a system of multiple aromatic rings conjugated by carbon-carbon bonds, and any aromatic ring system can be a single aromatic monocyclic ring or a fused aromatic ring. For example, heteroaryl groups can include, but are not limited to: thiophene, furanyl, pyrrole, imidazolyl, thiazolyl, oxazolyl, oxadiazolyl, triazolyl, pyridyl, bipyridyl, pyrimidinyl, triazinyl, acridinel, pyridazinyl, pyrazinyl, quinolinyl, quinazolinyl, quinoxazinyl, phenoxazinyl, phthalazinyl, pyridopyrimidinyl, pyridopyrazinyl, isoquinolinyl, indolyl, carbazole, benzoxazolyl, and benzimidazolyl. The group includes, but is not limited to, benzothiazolyl, benzotriazolyl, benzocarbazolyl, benzothiophene, dibenzothiophene, thienozothiophene, benzofuranyl, phenanthrolinel, isoxazolyl, thiadiazolyl, benzothiazolyl, phenothiazinyl, silanylfluorenyl, dibenzofuranyl, and N-arylcarbazolyl (such as N-phenylcarbazolyl), N-heteroarylcarbazolyl (such as N-pyridylcarbazolyl), and N-alkylcarbazolyl (such as N-methylcarbazolyl), etc. Among these, thiophene, furanyl, and phenanthrolinel are heteroaryl groups of the single aromatic ring type, while N-arylcarbazolyl and N-heteroarylcarbazolyl are heteroaryl groups of the polycyclic system type linked by carbon-carbon conjugation. The heteroaryl group disclosed herein may contain 5 to 20 carbon atoms. In some exemplary embodiments, the number of carbon atoms in the heteroaryl group may be 5 to 10, and in other exemplary embodiments, the number of carbon atoms in the aryl group may be 5 to 19. For example, the number of carbon atoms in the heteroaryl group may be 5, 6, 7, 8, 9, 10, 11, 12, 13, 18, 19, or 20, etc., and this disclosure does not limit this.

[0121] In exemplary embodiments of this disclosure, a heteroaryl group refers to a divalent group formed by the loss of a hydrogen atom from a heteroaryl group.

[0122] In exemplary embodiments of this disclosure, the substituted heteroaryl group may be one or more hydrogen atoms of the heteroaryl group that are replaced by groups such as deuterium atoms, halogen groups, cyano groups, aryl groups, heteroaryl groups, alkyl groups, and cycloalkyl groups. Aryl-substituted heteroaryl groups may include, but are not limited to, phenyl-substituted dibenzofuranyl, phenyl-substituted dibenzothiophenyl, and N-phenylcarbazoyl groups. Furthermore, the number of carbon atoms in the substituted heteroaryl group refers to the total number of carbon atoms in the heteroaryl group and the substituents on the heteroaryl group. The halogen group may include fluorine, iodine, bromine, chlorine, etc.

[0123] In exemplary embodiments of this disclosure, the heteroaryl group used as a substituent may include, but is not limited to, pyridyl, benzimidazolyl, benzothiazolyl, benzoxazolyl, benzopyridyl, benzotriazolyl, etc.

[0124] In exemplary embodiments of this disclosure, fusion refers to any ring structure herein fused with an existing ring structure in the disclosed compound. When the fused ring is a heterocyclic or heteroaryl ring, any carbon atom on the existing ring structure that is part of the fused heterocyclic or heteroaryl ring is replaced by a nitrogen atom. A fused aryl refers to an aryl ring as defined herein fused with at least one other ring (e.g., an aryl ring, a heterocyclic ring, or a heteroaryl ring). A fused bicyclic aryl refers to a fused aryl ring fused with one other ring.

[0125] In exemplary embodiments of this disclosure, an aromatic amine group refers to an amine having an aromatic substituent, namely -NH2, -NH, or a nitrogen-containing group attached to an aromatic hydrocarbon.

[0126] In exemplary embodiments of this disclosure, the molecular structure of a cycloalkylnaphthalene group may include two parts: a naphthalene-attached five-membered ring and an alkyl group. The naphthalene-attached five-membered ring is formed by two benzene rings connected by external five-membered rings. The alkyl group is a hydrocarbon group composed of a carbon chain and hydrogen atoms. For example, the alkyl group may be alkyl groups of different lengths, such as methyl, ethyl, or propyl.

[0127] The synthesis process of compound 1 will be illustrated below using a compound having the structure shown in formula (3-1) as an example.

[0128] The synthesis process of compound 1 is shown below:

[0129]

[0130] The synthesis process of compound 1 may include:

[0131] 1. Synthesis of intermediate: 200 mL of toluene solvent was added to the reaction flask, and then raw material 1 (1 mol) and raw material 2 (1.1 mol) were added to the 200 mL of toluene solvent in sequence. The mixture was heated to 110 °C, stirred to dissolve, and nitrogen gas was continuously and gradually introduced. Subsequently, sodium tert-butoxide (1.5 mol), XantPhos (4,5-bisdiphenylphosphine-9,9-dimethyloxanthracene) (0.02 mol) and Pd(AcO)2 (palladium acetate) (0.01 mol) were added. The reaction was refluxed, the solution turned black, and flocculent matter gradually appeared after the reaction continued. The reaction was carried out for 7 hours, filtered and washed with dichloromethane. The intermediate was obtained by purification by extraction, recrystallization and other methods.

[0132] 2. Synthesis of Compound 1: Subsequently, 150 mL of toluene solvent was added to the reaction flask, followed by the addition of intermediate (1 mol) and starting material 3 (1.05 mol) to the 150 mL toluene solvent. The mixture was stirred and heated to 110 °C, refluxed for 30 minutes until the solution was clear. Then, sodium tert-butoxide (2 mol), Sphos (2-bicyclohexylphosphine-2',6'-dimethoxybiphenyl) (0.04 mol) and Pd2(dba)3 (tris(dibenzylacetone)dipalladium) (0.02 mol) were added. The reaction was carried out for 7 hours, filtered, and washed with dichloromethane. Compound 1 was obtained by purification methods such as extraction, column chromatography, and recrystallization, with a purity of 99.12% and a yield of 86%.

[0133] Furthermore, the synthesis processes of compounds 2 to 53 are similar to those of compound 1 in the above examples. Compounds 2 to 53 can be synthesized by referring to the synthesis principles in the above examples, and will not be listed one by one here.

[0134] Table 1 shows the comparison results of the refractive indices of the compound materials and comparative materials at different wavelengths in the exemplary embodiments of this disclosure. As shown in Table 1, the compound materials in the exemplary embodiments of this disclosure include: compound 1, compound 9, compound 14, compound 15, compound 22, compound 23, compound 28, compound 30, and compound 43; the comparative materials include: a compound with the structure shown in formula (5-1) (denoted as comparative CP-1) and a compound with the structure shown in formula (5-2) (denoted as comparative CP-2). The refractive index was measured using an ellipsometer; the instrument scanning range was 245 to 1000 nm; a thin film was deposited on a silicon wafer with a film thickness of 50 nm, and the results shown in Table 1 were obtained.

[0135]

[0136] Table 1. Refractive indices of the material disclosed herein and the comparative material at different wavelengths

[0137]

[0138]

[0139] As shown in Table 1, at different wavelengths (e.g., 460nm, 530nm, and 620nm), the compound material in this disclosure exhibits a significant improvement in refractive index compared to comparative materials CP-1 and CP-2. Since refractive index is a crucial physical parameter of the capping layer material, directly determining the optical coupling efficiency of the device, using the compound material in this disclosure as the capping layer in the exemplary organic electroluminescent device can significantly improve the refractive index of the capping layer. This is beneficial for the optical coupling output of the device, increasing the light extraction efficiency and thus enhancing the overall luminous efficiency and lifetime of the organic electroluminescent device.

[0140] Table 2 shows the performance comparison results of the devices in the exemplary embodiments of this disclosure and the comparative devices. As shown in Table 2, the devices in the exemplary embodiments of this disclosure include: D1, D1A, D14, D14A, D22, D22A, D23, D23A, D28, D28A, D43, and D43A; the comparative devices include: R1, R2, R3, and R4. The device structure is: ITO / Ag / ITO(80 / 1000 / 80nm) / HIL(10nm) / HTL(110nm) / EBL(5nm) / BH:BD(20nm,3%) / HBL(5nm) / ETL:LIQ(30nm,50%) / EIL(1nm) / Mg:Ag(13nm) / CPL(65nm). The anode uses ITO / Ag / ITO with a thickness of 80 / 1000 / 80 nm; the cathode uses a Mg:Ag alloy with a thickness of 13 nm; BH:BD (20 nm, 3%) refers to the co-evaporation of the blue light host material BH and the blue light guest material BD at a volume ratio of 97:3 to form the emissive layer (EML) with a thickness of 20 nm; ETL:LIQ (30 nm, 50%) refers to the electron transport layer (ETL) using a doped structure, with LIQ (an organic salt, lithium 8-hydroxyquinoline) as the guest material, doped at 50%, and a thickness of 30 nm. The hole injection layer (HIL) has a thickness of 10 nm; the hole transport layer (HTL) has a thickness of 110 nm; the electron blocking layer (EBL) has a thickness of 5 nm; the hole blocking layer (HBL) has a thickness of 5 nm; the electron injection layer (EIL) has a thickness of 1 nm; and the capping layer (CPL) has a thickness of 65 nm.

[0141] The comparative materials include: a compound with the structure shown in formula (6-1) (denoted as comparative HTL1) and a compound with the structure shown in formula (6-2) (denoted as comparative HTL2).

[0142]

[0143] The fabrication process of device D1 is as follows: The pre-prepared ITO substrate is cleaned and dried. HIL material, HTL material (using comparative material HTL1), and EBL material are sequentially deposited on the anode (ITO). Then, the light-emitting layer BH:BD material is deposited. HBL material, ETL material, and EIL material are deposited on the light-emitting layer. Then, the cathode is deposited. Subsequently, CPL material (using compound 1 of this disclosure) is deposited on the cathode to obtain device D1.

[0144] The fabrication process for other devices is similar to that for device D1, and the same process can be used to fabricate other devices. Specifically: Device D1A fabrication process: Replace the HTL material in device D1 with compound 1A, otherwise remain the same. Device D14 fabrication process: Replace the CPL material in device D1 with compound 14, otherwise remain the same. Device D14A fabrication process: Replace the HTL material in device D1 with compound 14A, and replace the CPL material in device D1 with compound 14, otherwise remain the same. Device D22 fabrication process: Replace the CPL material in device D1 with compound 22, otherwise remain the same. Device D22A fabrication process: Replace the HTL material in device D1 with compound 22A, and replace the CPL material in device D1 with compound 22, otherwise remain the same. Device D23 fabrication process: Replace the CPL material in device D1 with compound 23, otherwise remain the same. Fabrication process of device D23A: Replace the HTL material in device D1 with compound 23A, replace the CPL material in device D1 with compound 23, and keep everything else the same. Fabrication process of device D28: Replace the HTL material in device D1 with the reference compound HTL2, replace the CPL material in device D1 with compound 28, and keep everything else the same. Fabrication process of device D28A: Replace the HTL material in device D1 with compound 28A, replace the CPL material in device D1 with compound 28, and keep everything else the same. Fabrication process of device D43: Replace the HTL material in device D1 with the reference compound HTL2, replace the CPL material in device D1 with compound 43, and keep everything else the same. Fabrication process of device D43A: Replace the HTL material in device D1 with compound 43A, replace the CPL material in device D1 with compound 43, and keep everything else the same. Comparative device R1 fabrication process: The HTL material in device D1 was replaced with chemical reference HTL2, and the CPL material in device D1 was replaced with reference CP-1; all other aspects remained unchanged. Comparative device R2 fabrication process: The HTL material in device D1 was replaced with chemical reference HTL, and the CPL material in device D1 was replaced with reference CP-2; all other aspects remained unchanged. Comparative device R3 fabrication process: The CPL material in device D1 was replaced with reference CP-1; all other aspects remained unchanged. Comparative device R4 fabrication process: The CPL material in device D1 was replaced with reference CP-2; all other aspects remained unchanged.

[0145] Table 2. Performance Comparison Between the Device in this Disclosure and the Comparative Device

[0146] Devices HTL materials CPL material Voltage (V) Efficiency (cd / A) Lifespan (h) D1 Comparative material HTL1 Compound 1 99％ 103％ 103％ D1A Compound 1A Compound 1 98％ 105％ 103％ D14 Comparative material HTL1 Compound 14 98％ 104％ 105％ D14A Compound 14A Compound 14 97％ 106％ 105％ D22 Comparative material HTL1 Compound 22 99％ 106％ 101％ D22A Compound 22A Compound 22 98％ 107％ 102％ D23 Comparative material HTL1 Compound 23 98％ 106％ 102％ D23A Compound 23A Compound 23 98％ 106％ 102％ D28 Comparative agent HTL2 Compound 28 98％ 107％ 101％ D28A Compound 28A Compound 28 97％ 109％ 103％ D43 Comparative agent HTL2 Compound 43 99％ 104％ 100％ D43A Compound 43A Compound 43 99％ 106％ 100％ R1 Comparative agent HTL2 Comparative material CP-1 100％ 100％ 100％ R2 Comparative agent HTL2 Comparative material CP-2 100％ 103％ 100％ R3 Comparative material HTL1 Comparative material CP-1 100％ 101％ 100％ R4 Comparative material HTL1 Comparative material CP-2 100％ 102％ 100％

[0147] As shown in Table 2, devices D1, D1A, D14, D14A, D22, D22A, D23, D23A, D28, D28A, D43, and D43A, which employ the scheme described in this disclosure, exhibit varying degrees of improvement in device efficiency and lifetime, and their voltage is reduced to varying degrees. This disclosure improves the overall efficiency and lifetime of the OLED device by introducing cycloalkylnaphthalene groups to increase the refractive index of the CPL material and enhance the mobility and lifetime of the hole transport layer.

[0148] For example, as shown in Table 2, compared to the comparative devices R3 and R4, devices D1, D14, D22, and D23 in this disclosure exhibit significant improvements in luminous efficiency and significant reductions in voltage. This indicates that the introduction of cycloalkylnaphthalene groups into the CPL material of the devices in this disclosure can improve the refractive index and thermal stability, which is beneficial to the optical coupling output of the device, improves the mobility and lifetime of the hole transport layer, increases the device efficiency, and reduces the device voltage. Furthermore, devices D1A, D14A, D22A, and D23A in this disclosure exhibit even more significant improvements in luminous efficiency and even more significant reductions in voltage. This indicates that the CPL material of the devices in this disclosure has high refractive index and high thermal stability, which can reduce voltage and improve device efficiency. In addition, the HTL material of the devices in this disclosure has relatively fast mobility and a more matched energy level, which can further reduce voltage and further improve device efficiency, thereby significantly improving the performance of OLED devices.

[0149] For example, as shown in Table 2, compared to the comparative devices R1 and R2, devices D28 and D43 in this disclosure exhibit a significant improvement in luminous efficiency and a significant reduction in voltage. This indicates that the CPL material in the devices of this disclosure has a high refractive index and high thermal stability, which is beneficial for the optical coupling output of the devices, improving device efficiency and reducing device voltage. Furthermore, devices D28A and D43A in this disclosure exhibit an even more significant improvement in luminous efficiency and a more significant reduction in voltage. This indicates that the CPL material in the devices of this disclosure has a high refractive index and high thermal stability, which can reduce voltage and improve device efficiency. In addition, the HTL material in the devices of this disclosure has a relatively fast hole mobility and a more matched energy level, which can further reduce voltage and further improve device efficiency, thereby significantly improving the performance of OLED devices.

[0150] Thus, the organic light-emitting device in the exemplary embodiments of this disclosure, by introducing cycloalkylnaphthalene groups into the CPL material, improves the refractive index and thermal stability of the CPL material, giving it a stronger electron-donating ability. This enhances the hole mobility in the film layer region (such as the hole transport layer) between the anode and the light-emitting layer. Furthermore, the increased molecular weight relative to naphthalene improves the device lifetime, thereby enhancing the overall luminous efficiency and lifetime of the organic light-emitting device. Additionally, by including aromatic amine groups and cycloalkylnaphthalene groups in the HTL material, the mobility and hole transport rate of the HTL material are increased, resulting in a more matched energy level. This further reduces the voltage and improves the device efficiency. Moreover, since the photoluminescence (PL) spectrum of aromatic amine materials is in the range of 400 nm to 450 nm, it is beneficial for improving device efficiency. Ultimately, this achieves better luminous efficiency, lower voltage, and longer lifetime, resulting in a high-performance OLED device.

[0151] This disclosure also provides a display substrate, including: a substrate and a plurality of light-emitting devices disposed on one side of the substrate, wherein at least one of the plurality of light-emitting devices is an organic electroluminescent device described in one or more of the above embodiments.

[0152] This disclosure also provides a display device, which may include the display substrate described in one or more of the above embodiments.

[0153] Here, the display device can be a product with image (including still images or moving images, where moving images can be video) display capabilities. In some exemplary embodiments, the display device can be, but is not limited to, any product or component with display capabilities such as a mobile phone, tablet computer, television, monitor, laptop computer, in-vehicle display, or navigation device. This disclosure does not limit the type of display device. Other essential components of the display device are those that should be understood by those skilled in the art, and are not described in detail here, nor should they be construed as limiting this disclosure.

[0154] Furthermore, the display device in this disclosure embodiment may include, in addition to the structures exemplified in the above embodiments, other necessary components and structures, such as a circuit for providing electrical signals to the display substrate to drive the display substrate to emit light. This circuit may be called a control circuit, and may include at least one of a circuit board and an integrated circuit (IC) electrically connected to the display substrate; or a power supply system for supplying power to the display substrate. Those skilled in the art can design and supplement accordingly based on the type of display substrate and usage requirements, which will not be elaborated here.

[0155] The description of the above display device embodiments is similar to that of the above organic electroluminescent device embodiments, and has similar beneficial effects. For technical details not disclosed in the display device embodiments of this disclosure, those skilled in the art should refer to the descriptions in the organic electroluminescent device embodiments of this disclosure for understanding, and will not be repeated here.

[0156] While the embodiments disclosed herein are as described above, the above content is merely for the purpose of facilitating understanding of this disclosure and is not intended to limit this disclosure. Any person skilled in the art to which this disclosure pertains may make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed herein, but the scope of patent protection of this disclosure shall still be determined by the scope defined in the appended claims.

Claims

1. An organic electroluminescent device, comprising: An anode, a first functional layer, a light-emitting layer, a second functional layer, a cathode, and a capping layer are stacked in sequence, wherein the material of the capping layer includes a compound with the structure shown in formula (II); Formula (II); In formula (II), L3, L4 and L5 are each independently selected from any of the following groups: single bond, arylene group with 6 to 20 substituted or unsubstituted carbon atoms; at least one of Ar3 and Ar4 is selected from any of the groups with structures as shown in formulas (2-1) to (2-7); ； ； ； in, Indicates a chemical bond; X is selected from CR, NR, oxygen, or sulfur; CR is a carbon atom bonded to hydrogen or an alkyl group; NR is a nitrogen atom bonded to hydrogen or an alkyl group; Y, Y1, Y2, Y3, and Y4 are each independently CR or nitrogen, and only one of Y1 to Y4 is nitrogen; Z is CR or NR; R is selected from any of the following: hydrogen, deuterium, alkyl group with 2 to 30 carbon atoms, aryl group with 6 to 20 carbon atoms, heteroaryl group with 5 to 20 carbon atoms; Ar is selected from a group containing only one heteroatom, wherein the heteroatom is nitrogen, oxygen, or sulfur; Ar3 and Ar4 not selected from the structures shown in formulas (2-1) to (2-7), are selected from any of the following groups: alkyl groups with 2 to 20 substituted or unsubstituted carbon atoms, aryl groups with 6 to 20 substituted or unsubstituted carbon atoms, and heteroaryl groups with 5 to 20 substituted or unsubstituted carbon atoms containing one or more heteroatoms; wherein the heteroatoms are nitrogen, oxygen or sulfur.

2. The organic electroluminescent device according to claim 1, characterized in that, For Ar3 and Ar4, if not selected from the structures shown in formulas (2-1) to (2-7), select any one of the groups shown in the following structures: 。 3. The organic electroluminescent device according to claim 1, characterized in that, The material of the coating layer is selected from any of the compounds with the following structures: ； ； ； ； ； ； ； ； 。 4. An organic electroluminescent device, comprising: The anode, first functional layer, light-emitting layer, second functional layer, cathode, and capping layer are stacked sequentially, wherein the material of the capping layer is selected from any of the compounds with the following structures: ； ； 。 5. The organic electroluminescent device according to any one of claims 1 to 4, characterized in that, The first functional layer includes multiple organic layers, and at least one of the multiple organic layers is made of a compound with the structure shown in formula (III); Formula (III); In formula (III), G1 and R are each independently selected from any of the following groups: hydrogen, deuterium, aryl with 6 to 12 substituted or unsubstituted carbon atoms; L1 and L2 are each independently selected from any of the following groups: direct bond, aryl with 6 to 24 substituted or unsubstituted carbon atoms, heteroaryl with 5 to 20 substituted or unsubstituted carbon atoms; Ar1 ​​and Ar2 are each independently selected from any of the following groups: aryl with 6 to 30 substituted or unsubstituted carbon atoms, heteroaryl with 5 to 30 substituted or unsubstituted carbon atoms; (D)m represents a group with m deuterium atoms, (D)n represents a group with n deuterium atoms, where m and n are integers from 0 to 4; (D)o represents a group with o deuterium atoms, where o is an integer from 0 to 8; p is an integer from 0 to 2.

6. The organic electroluminescent device according to claim 5, characterized in that, In formula (III) Choose any one of the structures shown in equations (a1) to (a32): ； ； ； ； 。 7. The organic electroluminescent device according to claim 5, characterized in that, At least one of the multilayer organic layers is selected from any one of the compounds with structures shown in formulas (4-1) to (4-3): 。 8. The organic electroluminescent device according to claim 5, characterized in that, At least one of the multilayer organic layers includes at least one of a hole injection layer, a hole transport layer, and an auxiliary light-emitting layer.

9. The organic electroluminescent device according to any one of claims 1 to 4, characterized in that, The first functional layer comprises multiple organic layers, wherein at least two of the multiple organic layers are made of aromatic amine groups, and at least one of the multiple organic layers is made of cycloalkylnaphthalene groups.

10. The organic electroluminescent device according to claim 9, characterized in that, At least two of the multilayer organic layers include at least two of a hole injection layer, a hole transport layer, and an auxiliary light-emitting layer, and at least one of the multilayer organic layers includes at least one of a hole injection layer, a hole transport layer, and an auxiliary light-emitting layer.

11. The organic electroluminescent device according to claim 10, characterized in that, The hole injection layer contains the same material as the hole transport layer.

12. A display substrate, comprising: The substrate and a plurality of light-emitting devices disposed on one side of the substrate, wherein at least one of the plurality of light-emitting devices is an organic electroluminescent device as described in any one of claims 1 to 11.

13. A display device, comprising: The display substrate as described in claim 12.

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