Organic matter, light-emitting device, laminated light-emitting device, display substrate and display apparatus

Abstract

A laminated light-emitting device (D) comprising a first electrode (d1), a second electrode (d2), at least two light-emitting units (d30) and at least one laminated connection layer (d4). The laminated connection layer (d4) comprises an N-type charge generation layer (d41) and a P-type charge generation layer (d42), which are arranged in a stacked manner. The N-type charge generation layer (d41) is of a binary doped structure including a first host material and a first guest material, and the P-type charge generation layer (d42) is of a binary doped structure including a second host material and a second guest material. An absolute value of a difference value between a highest occupied molecular orbital energy level of the second host material and a highest occupied molecular orbital energy level of the first host material is greater than 0.3 electron volts, and an absolute value of a difference value between a lowest unoccupied molecular orbital energy level of the second host material and a lowest unoccupied molecular orbital energy level of the first host material is greater than 0.1 electron volts.

Description

Organic matter, light-emitting device, stacked light-emitting device, display substrate and display device

[0001] This application claims priority to Chinese patent application No. 202210788076.X filed on July 6, 2022, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present disclosure relates to the field of display technology, and in particular to an organic matter, a light-emitting device, a stacked light-emitting device, a display substrate, and a display device. Background Art

[0003] In the field of display technology, organic light-emitting diode (OLED) display devices have been widely used in many fields such as flat panel displays, flexible displays, automotive displays and solid-state lighting due to their advantages such as wide color gamut, high contrast, energy saving and foldability.

[0004] Summary of the Invention

[0005] In one aspect, a stacked light-emitting device is provided, comprising a first electrode, a second electrode, at least two light-emitting units, and at least one stacked connecting layer. The at least two light-emitting units are stacked between the first electrode and the second electrode, and the stacked connecting layer is disposed between every two adjacent light-emitting units. The stacked connecting layer includes an N-type charge generation layer and a P-type charge generation layer stacked together.

[0006] The N-type charge generation layer is a binary doped structure comprising a first host material and a first guest material, and the P-type charge generation layer is a binary doped structure comprising a second host material and a second guest material. The absolute value of the difference between the highest occupied molecular orbital energy level of the second host material and the highest occupied molecular orbital energy level of the first host material is greater than 0.3 electron volts, and the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the second host material and the lowest unoccupied molecular orbital energy level of the first host material is greater than 0.1 electron volts.

[0007] In some embodiments, the first guest material comprises at least one of a metal or an organic material. When the first guest material is a metal, the absolute value of the difference between the work function of the first guest material and the lowest unoccupied molecular orbital energy level of the first host material is less than 1.0 electron volt; and when the first guest material is an organic material, the absolute value of the difference between the highest occupied molecular orbital energy level of the first guest material and the lowest unoccupied molecular orbital energy level of the first host material is less than 1.0 electron volt.

[0008] In some embodiments, the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the second guest material and the highest occupied molecular orbital energy level of the second host material is less than 0.5 electron volts.

[0009] In some embodiments, the first host material has a conjugated segment in its structure; the conjugated segment has at least two benzene rings, and all the benzene rings in the conjugated segment are π-π conjugated structures.

[0010] In some embodiments, at least one substituent of the conjugated segment has a phosphorus-oxy group.

[0011] [Corrected 16.04.2024 according to Rule 26] In some embodiments, the first host material has a structure as shown in formula (I):

[0012] Wherein, R1, R2, R3 and R4 are independently selected from hydrogen, deuterium, halogen, substituted or unsubstituted C6~C 60 aryl, substituted or unsubstituted C6~C 60 Heteroaryl, substituted or unsubstituted C1~C 20 Alkyl, substituted or unsubstituted C3~C 20 Cycloalkyl, substituted or unsubstituted C1~C 20 Heteroalkyl, substituted or unsubstituted C7~C 30 Aralkyl, substituted or unsubstituted C1~C 20 Alkoxy, substituted or unsubstituted C6~C 30 any one of the structures shown in formula (II).

[0013] [Corrected 16.04.2024 according to Rule 26] wherein at least one of said R1, said R2, said R3 and said R4 has the structure represented by formula (II):

[0014] Wherein, * represents the site of connection with the carbon atom. L1 is selected from: single bond, substituted or unsubstituted C6~C 60 aryl, substituted or unsubstituted C6~C 60 Heteroaryl, substituted or unsubstituted C1~C 20 Alkyl, substituted or unsubstituted C3~C 20 Cycloalkyl, substituted or unsubstituted C1~C 20 Heteroalkyl, substituted or unsubstituted C7~C 30 Aralkyl, substituted or unsubstituted C1~C 20 Alkoxy, substituted or unsubstituted C6~C 30X1 and X2 are each independently selected from hydrogen, deuterium, halogen, substituted or unsubstituted C6 to C 60 aryl, substituted or unsubstituted C6~C 60 Heteroaryl, substituted or unsubstituted C1~C 20 Alkyl, substituted or unsubstituted C3~C 20 Cycloalkyl, substituted or unsubstituted C1~C 20 Heteroalkyl, substituted or unsubstituted C7~C 30 Aralkyl, substituted or unsubstituted C1~C 20 Alkoxy, substituted or unsubstituted C6~C 30 Any of the aryloxy groups.

[0015] In some embodiments, at least one of R3 and R4 has the structure shown in formula (II).

[0016] In some embodiments, both R3 and R4 have the structure shown in formula (II).

[0017] [Corrected 16.04.2024 according to Rule 26] In some embodiments, the first host material has a structure as shown in any one of Formulas (1-1) to (1-10):

[0018] In some embodiments, the light-emitting unit includes a light-emitting layer, which is a binary doping structure comprising a third host material and a third guest material; the structure of the third host material has a conjugated segment; the conjugated segment has at least two benzene rings, and all the benzene rings in the conjugated segment are π-π conjugated structures.

[0019] [Corrected 16.04.2024 according to Rule 26] In some embodiments, the third host material has a structure as shown in formula (III):

[0020] Wherein, A1 and A2 are independently selected from hydrogen, deuterium, halogen, substituted or unsubstituted C6~C 60 aryl, substituted or unsubstituted C6~C 60 Heteroaryl, substituted or unsubstituted C1~C 20 Alkyl, substituted or unsubstituted C3~C 20 Cycloalkyl, substituted or unsubstituted C1~C 20 Heteroalkyl, substituted or unsubstituted C7~C 30 Aralkyl, substituted or unsubstituted C1~C 20 Alkoxy, substituted or unsubstituted C6~C 30Any of the aryloxy groups.

[0021] [Corrected 16.04.2024 according to Rule 26] In some embodiments, the third host material has a structure as shown in any one of Formulas (3-1) to (3-12):

[0022] In another aspect, a stacked light-emitting device is provided. The stacked light-emitting device includes a first electrode, a second electrode, at least two light-emitting units, and at least one stacked connecting layer. The at least two light-emitting units are stacked between the first electrode and the second electrode. The light-emitting units include a light-emitting layer. The stacked connecting layer is disposed between each two adjacent light-emitting units. The stacked connecting layer includes an N-type charge generation layer and a P-type charge generation layer stacked together.

[0023] At least three film layers in the stacked light-emitting device include materials having conjugated segments, and the at least three film layers include at least one of the light-emitting layer and the N-type charge generation layer.

[0024] In some embodiments, the conjugated segment has at least two benzene rings, and all benzene rings in the conjugated segment are in a π-π conjugated structure.

[0025] In some embodiments, at least one of the materials having a conjugated segment has a phosphorus-oxy group in at least one substituent of the conjugated segment.

[0026] In some embodiments, at least two film layers in the stacked light-emitting device have different conjugated segments.

[0027] In some embodiments, in the stacked light-emitting device, there are at least two light-emitting layers, and an N-type charge generation layer located between the at least two light-emitting layers includes a material having the conjugated segment.

[0028] In some embodiments, all the light-emitting layers of the stacked light-emitting device include at least two light-emitting layers made of the same material.

[0029] In some embodiments, the light-emitting layer includes a binary doping structure comprising a third host material and a third guest material; the third host material has the conjugated segment in its structure.

[0030] [Corrected 16.04.2024 according to Rule 26] In some embodiments, the third host material has a structure as shown in formula (III):

[0031] Wherein, A1 and A2 are independently selected from hydrogen, deuterium, halogen, substituted or unsubstituted C6~C60 aryl, substituted or unsubstituted C6~C 60 Heteroaryl, substituted or unsubstituted C1~C 20 Alkyl, substituted or unsubstituted C3~C 20 Cycloalkyl, substituted or unsubstituted C1~C 20 Heteroalkyl, substituted or unsubstituted C7~C 30 Aralkyl, substituted or unsubstituted C1~C 20 Alkoxy, substituted or unsubstituted C6~C 30 Any of the aryloxy groups.

[0032] [Corrected 16.04.2024 according to Rule 26] In some embodiments, the third host material has a structure as shown in any one of Formulas (3-1) to (3-12):

[0033] In some embodiments, the N-type charge generation layer includes a binary doped structure comprising a first host material and a first guest material; the first host material has the conjugated segment in its structure.

[0034] In some embodiments, the P-type charge generation layer is a binary doped structure comprising a second host material and a second guest material; the absolute value of the difference between the highest occupied molecular orbital energy level of the second host material and the highest occupied molecular orbital energy level of the first host material is greater than 0.3 electron volts, and the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the second host material and the lowest unoccupied molecular orbital energy level of the first host material is greater than 0.1 electron volts.

[0035] In some embodiments, the first guest material includes at least one of a metal or an organic matter; wherein the first guest material includes the metal, and the absolute value of the difference between the work function of the metal included in the first guest material and the lowest unoccupied molecular orbital energy level of the first host material is less than 1.0 electron volt; or, the first guest material includes the organic matter, and the absolute value of the difference between the highest occupied molecular orbital energy level of the organic matter included in the first guest material and the lowest unoccupied molecular orbital energy level of the first host material is less than 1.0 electron volt.

[0036] In some embodiments, the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the second guest material and the highest occupied molecular orbital energy level of the second host material is less than 0.5 electron volts.

[0037] [Corrected 16.04.2024 according to Rule 26] In some embodiments, the first host material has a structure as shown in formula (I):

[0038] [Corrected 16.04.2024 according to Rule 26] wherein R1, R2, R3 and R4 are each independently selected from: hydrogen, deuterium, halogen, substituted or unsubstituted C6-C 60 aryl, substituted or unsubstituted C6~C 60 Heteroaryl, substituted or unsubstituted C1~C 20 Alkyl, substituted or unsubstituted C3~C 20 Cycloalkyl, substituted or unsubstituted C1~C 20 Heteroalkyl, substituted or unsubstituted C7~C 30 Aralkyl, substituted or unsubstituted C1~C 20 Alkoxy, substituted or unsubstituted C6~C 30 Any one of the aryloxy groups, and the structures shown in formula (II); wherein at least one of the R1, the R2, the R3 and the R4 has the structure shown in formula (II):

[0039] Wherein, * indicates the site of attachment to the carbon atom;

[0040] L1 is selected from: single bond, substituted or unsubstituted C6~C 60 aryl, substituted or unsubstituted C6~C 60 Heteroaryl, substituted or unsubstituted C1~C 20 Alkyl, substituted or unsubstituted C3~C 20 Cycloalkyl, substituted or unsubstituted C1~C 20 Heteroalkyl, substituted or unsubstituted C7~C 30 Aralkyl, substituted or unsubstituted C1~C 20 Alkoxy, substituted or unsubstituted C6~C 30 Any of the aryloxy groups;

[0041] X1 and X2 are each independently selected from hydrogen, deuterium, halogen, substituted or unsubstituted C6-C 60 aryl, substituted or unsubstituted C6~C 60 Heteroaryl, substituted or unsubstituted C1~C 20 Alkyl, substituted or unsubstituted C3~C 20 Cycloalkyl, substituted or unsubstituted C1~C 20 Heteroalkyl, substituted or unsubstituted C7~C 30 Aralkyl, substituted or unsubstituted C1~C 20 Alkoxy, substituted or unsubstituted C6~C 30 Any of the aryloxy groups.

[0042] [Corrected 16.04.2024 according to Rule 26] In some embodiments, the first host material has a structure as shown in any one of Formulas (1-1) to (1-10):

[0043] In another aspect, a light-emitting device is provided, comprising a first electrode, a second electrode, and at least one light-emitting unit, wherein the at least one light-emitting unit is disposed between the first electrode and the second electrode, and wherein the light-emitting unit comprises a light-emitting layer.

[0044] The light-emitting layer is a binary doped structure comprising a third host material and a third guest material. The third host material has a conjugated segment in its structure; the conjugated segment has at least two benzene rings, and all the benzene rings in the conjugated segment are π-π conjugated structures.

[0045] [Corrected 16.04.2024 according to Rule 26] In some embodiments, the third host material has a structure as shown in formula (III):

[0046] Wherein, A1 and A2 are independently selected from hydrogen, deuterium, halogen, substituted or unsubstituted C6~C 60 aryl, substituted or unsubstituted C6~C 60 Heteroaryl, substituted or unsubstituted C1~C 20 Alkyl, substituted or unsubstituted C3~C 20 Cycloalkyl, substituted or unsubstituted C1~C 20 Heteroalkyl, substituted or unsubstituted C7~C 30 Aralkyl, substituted or unsubstituted C1~C 20 Alkoxy, substituted or unsubstituted C6~C 30 Any of the aryloxy groups.

[0047] [Corrected 16.04.2024 according to Rule 26] In some embodiments, the third host material has a structure as shown in any one of Formulas (3-1) to (3-12):

[0048] In another aspect, a display substrate is provided. The display substrate includes a substrate, multiple light-emitting devices, multiple pixel driving circuits, and an encapsulation layer. At least one of the light-emitting devices is a stacked light-emitting device or a light-emitting device as described in any of the above embodiments. The multiple pixel driving circuits are used to drive the at least one light-emitting device to emit light. The encapsulation layer is used to encapsulate the multiple light-emitting devices and the multiple pixel driving circuits.

[0049] [Corrected 16.04.2024 according to Rule 26] In another aspect, a display device is provided, comprising the display substrate as described in the above embodiment.

[0050] [Corrected 12.09.2024 according to Rule 26] In another aspect, an organic compound is provided having a structure as shown in formula (III):

[0051] Wherein, A1 and A2 are independently selected from hydrogen, deuterium, halogen, substituted or unsubstituted C6~C 60 aryl, substituted or unsubstituted C6~C 60 Heteroaryl, substituted or unsubstituted C1~C 20 Alkyl, substituted or unsubstituted C3~C 20 Cycloalkyl, substituted or unsubstituted C1~C 20 Heteroalkyl, substituted or unsubstituted C7~C 30 Aralkyl, substituted or unsubstituted C1~C 20 Alkoxy, substituted or unsubstituted C6~C 30 Any of the aryloxy groups.

[0052] [Corrected 16.04.2024 according to Rule 26] In some embodiments, the organic compound has any one of the following structures: BRIEF DESCRIPTION OF THE DRAWINGS

[0053] To more clearly illustrate the technical solutions of the present disclosure, the following briefly introduces the drawings required for use in some embodiments of the present disclosure. Obviously, the drawings described below are only drawings of some embodiments of the present disclosure, and those skilled in the art can also derive other drawings based on these drawings. Furthermore, the drawings described below are schematic diagrams and are not intended to limit the actual dimensions of the products, actual processes of the methods, actual timing of signals, and the like involved in the embodiments of the present disclosure.

[0054] FIG1 is a structural diagram of a display device according to some embodiments;

[0055] FIG2 is a structural diagram of a display module according to some embodiments;

[0056] FIG3 is a structural diagram of a display substrate according to some embodiments;

[0057] FIG4 is a structural diagram of a light emitting device in the related art;

[0058] FIG5 is a structural diagram of a stacked light emitting device in the related art;

[0059] FIG6 is a structural diagram of a stacked light emitting device according to some embodiments;

[0060] FIG. 7 is a structural diagram of a light emitting device according to some embodiments. DETAILED DESCRIPTION

[0061] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present disclosure. Obviously, the embodiments described are only some embodiments of the present disclosure, not all embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of the present disclosure.

[0062] Unless the context requires otherwise, throughout the specification and claims, the term "including" is to be interpreted as having an open, inclusive meaning, that is, "including, but not limited to." In the description of the specification, the terms "one embodiment," "some embodiments," "exemplary embodiments," "examples," or "some examples" are intended to indicate that a particular feature, structure, material, or characteristic associated with the embodiment or example is included in at least one embodiment or example of the present disclosure. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the particular features, structures, materials, or characteristics may be included in any one or more embodiments or examples in any appropriate manner.

[0063] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, "plurality" means two or more.

[0064] When describing some embodiments, the expressions "coupled" and "connected" and their derivatives may be used. For example, when describing some embodiments, the term "connected" may be used to indicate that two or more components are in direct physical or electrical contact with each other. For another example, when describing some embodiments, the term "coupled" may be used to indicate that two or more components are in direct physical or electrical contact. However, the term "coupled" or "communicatively coupled" may also refer to two or more components that are not in direct contact with each other, but still cooperate or interact with each other. The embodiments disclosed herein are not necessarily limited to the contents of this document.

[0065] “At least one of A, B and C” has the same meaning as “at least one of A, B or C” and both include the following combinations of A, B and C: A only, B only, C only, the combination of A and B, the combination of A and C, the combination of B and C, and the combination of A, B and C.

[0066] “A and / or B” includes the following three combinations: A only, B only, and a combination of A and B.

[0067] The use of "adapted to" or "configured to" herein is intended to be open and inclusive language that does not exclude devices adapted or configured to perform additional tasks or steps.

[0068] It will be understood that when a layer or element is referred to as being on another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may be present therebetween.

[0069] Exemplary embodiments are described herein with reference to cross-sectional and / or plan views that are idealized exemplary drawings. In the drawings, the thicknesses of layers and regions are exaggerated for clarity. Therefore, variations in shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are contemplated. Therefore, the exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but rather include deviations in shape due to, for example, manufacturing. For example, an etched region shown as a rectangle will typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the actual shape of regions of the device and are not intended to limit the scope of the exemplary embodiments.

[0070] As shown in FIG1 , some embodiments of the present disclosure provide a display device 100, which can be any device that displays an image, whether in motion (e.g., video) or fixed (e.g., still image), and whether text or text. More specifically, it is contemplated that some embodiments of the present disclosure may be implemented in or associated with a variety of electronic devices. The various electronic devices may include, for example (but not limited to), mobile phones, wireless devices, personal digital assistants (PDAs), handheld or portable computers, global positioning system (GPS) receivers / navigators, cameras, MP4 video players, video cameras, game consoles, watches, clocks, calculators, television monitors, flat-panel displays, computer monitors, automotive displays (e.g., odometer displays, etc.), navigation systems, cockpit controls and / or displays, displays of camera views (e.g., displays of rearview cameras in vehicles), electronic photographs, electronic billboards or signs, projectors, architectural structures, packaging, and aesthetic structures (e.g., displays of images of a piece of jewelry), etc.

[0071] In some embodiments, referring still to FIG. 1 , the display device 100 includes a display module 110 and a housing 120 .

[0072] In some examples, as shown in FIG. 2 , the display module 110 includes a display substrate 111 , a flexible circuit board 112 , and other electronic components.

[0073] It should be noted that the display substrate 111 can be of various types and can be selected based on actual needs. For example, the display substrate 111 can be an electroluminescent display substrate, such as an organic light emitting diode (OLED) display substrate or a quantum dot light emitting diode (QLED) display substrate, etc. This disclosure does not specifically limit this.

[0074] Hereinafter, some embodiments of the present disclosure will be exemplarily described by taking the display substrate 111 as an OLED display substrate as an example.

[0075] In some embodiments, as shown in FIG2 , the display substrate 111 may have a display area A within a dotted frame and a peripheral area B outside the dotted frame. The display area A is the area of ​​the display substrate 111 where images are displayed; the peripheral area B is the area where images are not displayed. The peripheral area B is configured to house display driver circuits, such as gate driver circuits and source driver circuits.

[0076] It should be noted that the present disclosure does not limit the location of peripheral area B. For example, peripheral area B can be located on one, two, or three sides of display area A. For another example, peripheral area B can surround display area A. Figure 2 illustrates the example of peripheral area B surrounding display area A.

[0077] In some examples, as shown in FIG2 , the display substrate 111 includes a plurality of sub-pixels P disposed on one side of the substrate 1 and located in the display area A. For example, the plurality of sub-pixels P include at least a first color sub-pixel, a second color sub-pixel, and a third color sub-pixel. The first color, the second color, and the third color may be three primary colors (e.g., red, green, and blue).

[0078] The plurality of sub-pixels P are arranged in a plurality of rows and columns, where each row includes a plurality of sub-pixels P arranged along a first direction X, and each column includes a plurality of sub-pixels P arranged along a second direction Y. The plurality of sub-pixels P arranged in a row along the first direction X may be referred to as sub-pixels P in the same row, and the plurality of sub-pixels P arranged in a column along the second direction Y may be referred to as sub-pixels P in the same column.

[0079] Here, the first direction X and the second direction Y intersect each other. The angle between the first direction X and the second direction Y can be set according to actual needs. For example, the angle between the first direction X and the second direction Y can be 85°, 89°, or 90°.

[0080] In some embodiments, as shown in Figures 2 and 3, the display substrate 111 includes a substrate 1, a circuit structure layer 2, a light-emitting structure layer 3, and an encapsulation layer 4. The circuit structure layer 2 is disposed on the substrate 1, and the circuit structure layer 2 includes a plurality of pixel driving circuits 10, each of which includes a plurality of transistors 101. The light-emitting structure layer 3 is disposed on a side of the circuit structure layer 2 away from the substrate 1. The light-emitting structure layer 3 includes a plurality of light-emitting devices D0, with each light-emitting device D0 correspondingly connected to each pixel driving circuit 10. The encapsulation layer 4 is disposed on a side of the light-emitting structure layer 3 away from the substrate 1, and is configured to encapsulate the circuit structure layer 2 and the light-emitting structure layer 3 on the substrate 1.

[0081] It should be noted that the transistors 101 included in the pixel driving circuit 10 may be of various types. For example, each transistor 101 included in the pixel driving circuit 10 may be a bottom-gate thin film transistor or a top-gate thin film transistor.

[0082] In some examples, the plurality of transistors 101 included in the pixel driving circuit 10 includes a driving transistor, which is electrically connected to the light-emitting device D0.

[0083] It should be noted that the driving transistor and the light emitting device D0 may be directly or indirectly electrically connected.

[0084] In some examples, as shown in FIG3 , transistor 101 includes an active layer 1011, a source 1012, a drain 1013, a gate 1014, and a gate insulating layer 1015. The source 1012 and the drain 1013 are in contact with the active layer 1011, respectively; and the gate insulating layer 1015 is disposed between the active layer 1011 and the gate 1014.

[0085] On this basis, as an example, referring to FIG3 , along a direction Z away from the substrate 1, the light-emitting device D0 includes a first electrode d1, a light-emitting functional layer d3, and a second electrode d2, which are sequentially arranged. The first electrode d1 is electrically connected to the source 1012 or drain 1013 of at least one transistor 101 among the multiple transistors 101. FIG3 illustrates the example of the electrical connection between the first electrode d1 and the source 1012 of a transistor 101.

[0086] It should be noted that the first electrodes d1 of the above-mentioned multiple light-emitting devices D0 together constitute the first electrode layer, the second electrodes d2 of the multiple light-emitting devices D0 together constitute the second electrode layer, and the light-emitting functional layers d3 of the multiple light-emitting devices D0 together constitute the organic light-emitting layer.

[0087] It should be noted that the first electrode layer may be a block structure, for example; the second electrode layer may be a full-surface structure, and cover the entire display area A; in addition, the organic light-emitting layer may be a full-surface structure, or a block structure, for example.

[0088] The first electrode d1 may be an anode or a cathode; correspondingly, the second electrode d2 may be a cathode or an anode.

[0089] In some examples, the first electrode d1 is an anode, and the first electrode layer is an anode layer; correspondingly, the second electrode d2 is a cathode, and the second electrode layer is a cathode layer. In this case, the light-emitting device D0 is an upright top-emitting light-emitting device. Because the first electrode d1 is opaque and the second electrode d2 is transparent or translucent, light emitted by the light-emitting functional layer d3 is emitted from the side of the light-emitting device D0 away from the substrate 1.

[0090] It should be understood that the following embodiments are all described by taking the first electrode d1 as the anode and the second electrode d2 as the cathode as an example.

[0091] In some examples, the encapsulation layer 4 may be an encapsulation film or an encapsulation cover.

[0092] In some examples, as shown in FIG. 3 , the display substrate 111 further includes a pixel defining layer 102 . The pixel defining layer 102 includes a plurality of opening regions, and one light emitting device D0 is disposed in one opening region.

[0093] In some examples, as shown in FIG3 , the display substrate 111 further includes a capping layer (CPL) 103 disposed on a side of the first electrode d1 away from the second electrode d2. For example, the capping layer 103 may be made of 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB).

[0094] 4 and 5 , the structure of the light emitting device D0 in the display substrate 111 will be described.

[0095] In some embodiments, the light emitting functional layer d3 of the light emitting device D0 includes only one light emitting unit d310. In this case, as shown in FIG4 , along a direction Z away from the first electrode d1, the light emitting device D0 includes the first electrode d1, the light emitting unit d310 and the second electrode d2.

[0096] In some examples, referring to Figure 4, along the direction Z away from the first electrode d1, the above-mentioned light-emitting unit d310 includes a hole injection layer (HIL) d3101, a hole transporting layer (HTL) d3102, an electron blocking layer (EBL) d3103, an emissive layer (EML) d3104, a hole blocking layer (HBL) d3105, an electron transporting layer (ETL) d3106 and an electron injection layer (EIL) d3107.

[0097] In this case, in combination with Figures 3 and 4, the working principle of the above-mentioned display substrate 111 is explained as follows: When the pixel driving circuit 10 is working and the driving voltage is transmitted to the light-emitting device D0 through the transistor 101 electrically connected to the first electrode d1, the first electrode d1 can generate positively charged holes under the action of the electric field, and the second electrode d2 can generate negatively charged electrons under the action of the electric field. At this time, the holes generated by the first electrode d1 can be injected into the hole transport layer d3102 through the hole injection layer d3101, and enter the light-emitting layer d3104 through the hole transport layer d3102 and the electron blocking layer d3103. Correspondingly, the electrons generated by the second electrode d2 can be injected into the electron transport layer d3106 through the electron injection layer d3107, and enter the light-emitting layer d3104 through the electron transport layer d3106 and the hole blocking layer d3105. The holes and electrons in the light-emitting layer d3104 recombine to form excitons, and the excitons return to the ground state through radiation transition, emitting photons. At this time, the light-emitting device D0 emits light.

[0098] In other embodiments, the light-emitting functional layer d3 of the light-emitting device D0 may include at least two stacked light-emitting units and at least one stacked connecting layer, and the stacked connecting layer is disposed between every two adjacent light-emitting units. In this case, the light-emitting device D0 may be referred to as a stacked light-emitting device.

[0099] In this case, every two light-emitting units in the stacked light-emitting device are connected in series via a stacked connecting layer, thereby improving the luminous efficiency of the stacked light-emitting device and extending the service life of the stacked light-emitting device. Furthermore, as the number of light-emitting units in the stacked light-emitting device increases, the luminous efficiency and service life of the stacked light-emitting device increase linearly.

[0100] In some examples, as shown in FIG5 , the light-emitting functional layer d3 of the light-emitting device D0 includes two stacked light-emitting units, namely a first light-emitting unit d301 and a second light-emitting unit d302. In this case, along a direction Z away from the first electrode d1, the light-emitting device D0 (i.e., the stacked light-emitting device) includes the first electrode d1, the first light-emitting unit d301, the stacked connecting layer d422, the second light-emitting unit d302, and the second electrode d2.

[0101] Along the direction Z away from the first electrode d1, the first light-emitting unit d301 includes a first hole injection layer d3211, a first hole transport layer d3212, a first electron blocking layer d3213, a first light-emitting layer d3214, a first hole blocking layer d3215, and a first electron transport layer d3216. Along the direction Z away from the first electrode d1, the second light-emitting unit d302 includes a second hole transport layer d3222, a second electron blocking layer d3223, a second light-emitting layer d3224, a second hole blocking layer d3225, a second electron transport layer d3226, and a second electron injection layer d3227.

[0102] The stacked connecting layer d422 includes an N-type charge generation layer d4221 and a P-type charge generation layer d4222. The N-type charge generation layer d4221 is disposed on the side of the stacked connecting layer d422 that is closer to the first electrode d1, and the P-type charge generation layer d4222 is disposed on the side of the stacked connecting layer d422 that is closer to the second electrode d2.

[0103] In this case, the operating principle of the display substrate 111 described above is described as follows, in conjunction with Figures 3 and 5: When the pixel driving circuit 10 is operating, the driving voltage can be transmitted to the stacked light-emitting device via the transistor 101 electrically connected to the first electrode d1. At this time, under the action of the electric field, the first electrode d1 can generate holes, the second electrode d2 can generate electrons, and the contact area between the N-type charge generation layer d4221 and the P-type charge generation layer d4222 can generate holes and electrons. At this time, the holes generated by the first electrode d1 can sequentially pass through the first hole injection layer d3211, the first hole transport layer d3212, and the first electron blocking layer d3213 to enter the first light-emitting layer d3214. Correspondingly, the electrons generated in the contact area between the N-type charge generation layer d4221 and the P-type charge generation layer d4222 can sequentially pass through the N-type charge generation layer d4221, the first electron transport layer d3216, and the first hole blocking layer d3215 to enter the first light-emitting layer d3214. Similarly, holes generated in the contact region between the N-type charge generation layer d4221 and the P-type charge generation layer d4222 can sequentially pass through the P-type charge generation layer d4222, the second hole transport layer d3222, and the second electron blocking layer d3223 into the second light-emitting layer d3224. Electrons generated by the second electrode d2 can sequentially pass through the second electron injection layer d3227, the second electron transport layer d3226, and the second hole blocking layer d3225 into the second light-emitting layer d3224. At this point, holes and electrons in the first light-emitting layer d3214, as well as holes and electrons in the second light-emitting layer d3224, recombine to form excitons, causing the stacked light-emitting device to emit light.

[0104] It should be noted that the N-type charge generation layer d4221 has electron injection capabilities, and the P-type charge generation layer d4222 has hole injection capabilities. Therefore, the N-type charge generation layer d4221 can be reused as the electron injection layer in the first light-emitting unit d301, and the P-type charge generation layer d4222 can be reused as the hole injection layer in the second light-emitting unit d302. In other words, the first light-emitting unit d301 of the stacked light-emitting device does not need to have an additional electron injection layer, and the second light-emitting unit d302 does not need to have an additional hole injection layer.

[0105] Of course, in the above-mentioned stacked light-emitting device, an additional electron injection layer located between the N-type charge generation layer d4221 and the first electron transport layer d3216 may be provided in the first light-emitting unit d301. Similarly, an additional hole injection layer located between the P-type charge generation layer d4222 and the second hole transport layer d3222 may be provided in the second light-emitting unit d302. The present disclosure does not impose any restrictions on this.

[0106] In this regard, the inventors of the present disclosure have discovered through research that: since the relevant technology has not reasonably designed the physical parameters of the N-type charge generation layer d4221 and the P-type charge generation layer d4222 of the above-mentioned stacked light-emitting device, the two cannot effectively cooperate with each other. At this time, the holes and electrons generated in the contact area between the N-type charge generation layer d4221 and the P-type charge generation layer d4222 in the stacked connecting layer d422 may be quenched, making it difficult to ensure the number of electrons and holes provided by the stacked connecting layer d422 to its two adjacent light-emitting units (for example, the above-mentioned first light-emitting unit d301 and the second light-emitting unit d302), which ultimately leads to a reduction in the luminous efficiency and service life of the stacked light-emitting device.

[0107] Based on this, embodiments of the present disclosure provide a stacked light-emitting device D. The stacked light-emitting device D includes a first electrode d1, a second electrode d2, at least two light-emitting units d30, and at least one stacked connecting layer d4. The at least two light-emitting units d30 are stacked between the first electrode d1 and the second electrode d2. A stacked connecting layer d4 is disposed between each two adjacent light-emitting units d30. The stacked connecting layer d4 includes an N-type charge generation layer d41 and a P-type charge generation layer d42. Among them, the N-type charge generation layer d41 is a binary doped structure including a first host material and a first guest material; the P-type charge generation layer d42 is a binary doped structure including a second host material and a second guest material; the absolute value of the difference between the highest occupied molecular orbital (HOMO) energy level of the second host material and the HOMO energy level of the first host material is greater than 0.3 electron volts, and the absolute value of the difference between the lowest unoccupied molecular orbital (LUMO) energy level of the second host material and the LUMO energy level of the first host material is greater than 0.1 electron volts.

[0108] In summary, the stacked light-emitting device D provided in the embodiment of the present invention can prevent the reverse transmission of electrons and holes generated in the contact area between the N-type charge generation layer d41 and the P-type charge generation layer d42 (i.e., prevent the electrons generated in the contact area from being transmitted to the P-type charge generation layer d42, and prevent the holes generated in the contact area from being transmitted to the N-type charge generation layer d41) by limiting the absolute value of the difference between the HOMO energy level of the second main material and the HOMO energy level of the first main material to be greater than 0.3 electron volts, and the absolute value of the difference between the LUMO energy level of the second main material and the LUMO energy level of the first main material to be greater than 0.1 electron volts, thereby avoiding quenching of electrons and holes generated in the contact area due to reverse transmission, thereby ensuring the stability of the number of carriers provided by each stacked connecting layer d4 to its two adjacent light-emitting units, and ultimately improving the luminous efficiency of the stacked light-emitting device D.

[0109] It should be noted that the absolute value of the difference between the HOMO energy level of the above-mentioned second host material and the HOMO energy level of the first host material is greater than 0.3 electron volts. It can be: the difference between the HOMO energy level of the second host material and the HOMO energy level of the first host material is greater than 0.3 electron volts. At this time, the HOMO energy level of the second host material is greater than the HOMO energy level of the first host material; or, the difference between the HOMO energy level of the second host material and the HOMO energy level of the first host material is less than negative 0.3 electron volts. At this time, the HOMO energy level of the second host material is less than the HOMO energy level of the first host material.

[0110] Similarly, the absolute value of the difference between the LUMO energy level of the second host material and the LUMO energy level of the first host material is greater than 0.1 electron volts, which can be: the difference between the LUMO energy level of the second host material and the LUMO energy level of the first host material is greater than 0.1 electron volts, at this time, the LUMO energy level of the second host material is greater than the LUMO energy level of the first host material; or, the difference between the LUMO energy level of the second host material and the LUMO energy level of the first host material is less than negative 0.1 electron volts, at this time, the LUMO energy level of the second host material is less than the LUMO energy level of the first host material.

[0111] It should be noted that in the stacked light-emitting device D provided in the embodiments of the present disclosure, the number of light-emitting units d30 can be selected as needed and is not limited in this embodiment. For example, the number of light-emitting units d30 is two, in which case the number of stacked connecting layers d4 is one; this can reduce the manufacturing cost of the stacked light-emitting device D. For another example, the number of light-emitting units d30 is three, in which case the number of stacked connecting layers d4 is two; this can improve the luminous efficiency of the stacked light-emitting device D and extend its service life.

[0112] In some examples, referring to FIG. 6 , along a direction Z away from the first electrode d1 , the stacked light emitting device D includes a first electrode d1 , a first light emitting unit d31 , a stacked connecting layer d4 , a second light emitting unit d32 and a second electrode d2 .

[0113] Along the direction Z away from the first electrode d1, the first light-emitting unit d31 includes a first hole injection layer d311, a first hole transport layer d312, a first electron blocking layer d313, a first light-emitting layer d314, a first hole blocking layer d315, and a first electron transport layer d316. Along the direction Z away from the first electrode d1, the second light-emitting unit d32 includes a second hole transport layer d322, a second electron blocking layer d323, a second light-emitting layer d324, a second hole blocking layer d325, a second electron transport layer d326, and a second electron injection layer d327.

[0114] Among them, the N-type charge generation layer d41 is arranged on a side of the stacked connection layer d4 close to the first electrode d1, and the P-type charge generation layer d42 is arranged on a side of the stacked connection layer d4 close to the second electrode d2.

[0115] In the above embodiment, since the function of the above-mentioned N-type charge generation layer d41 is to inject the electrons generated in the contact area between the N-type charge generation layer d41 and the P-type charge generation layer d42 into the first electron transport layer d316, and the function of the P-type charge generation layer d42 is to inject the holes generated in the contact area into the second hole transport layer d322, it is limited that the absolute value of the difference between the HOMO energy level of the second main material and the HOMO energy level of the first main material is greater than 0.3 electron volts, and the absolute value of the difference between the LUMO energy level of the second main material and the LUMO energy level of the first main material is greater than 0.3 electron volts. A value greater than 0.1 electron volts can prevent the reverse transmission of electrons and holes generated in the contact area between the N-type charge generation layer d41 and the P-type charge generation layer d42 (that is, prevent the electrons generated in the contact area from being transmitted to the P-type charge generation layer d42, and prevent the holes generated in the contact area from being transmitted to the N-type charge generation layer d41), thereby avoiding quenching of electrons and holes generated in the contact area due to reverse transmission, thereby ensuring the stability of the number of carriers provided by each stacked connecting layer d4 to its two adjacent light-emitting units, and ultimately improving the luminous efficiency of the stacked light-emitting device D.

[0116] It should be noted that the embodiment of the present disclosure does not limit the materials of the first electrode d1 and the second electrode d2.

[0117] In some examples, the material of the first electrode d1 is a metal. For example, the material of the first electrode d1 can be selected from at least one of silver (Ag), magnesium (Mg), copper (Cu), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca), Ca-LiF alloy, Al-LiF alloy, molybdenum (Mo), titanium (Ti), indium (In), tin (Sn), and zinc (Zn).

[0118] In some examples, the material of the second electrode d2 is a metal or an inorganic material. For example, when the material of the second electrode d2 is a metal, the material of the second electrode d2 can be silver (Ag), magnesium (Mg), ytterbium (Yb), lithium (Li), or calcium (Ca); when the material of the second electrode d2 is an inorganic material, the material of the second electrode d2 can be lithium oxide (Li2O), calcium oxide (CaO), lithium fluoride (LiF), or magnesium fluoride (MgF2).

[0119] In some embodiments, the first guest material of the N-type charge generation layer d41 includes at least one of a metal or an organic substance.

[0120] In some examples, the first guest material of the N-type charge generation layer d41 is a metal. In this case, the absolute value of the difference between the work function of the first guest material and the LUMO energy level of the first host material is less than 1.0 electron volt.

[0121] In the above embodiment, the function of the first guest material is to donate electrons from the first guest material to the first host material, enabling the electrons to be transported through the first host material within the N-type charge generation layer d41 and injected into the first electron transport layer d316 adjacent to the N-type charge generation layer d41. Furthermore, the closer the work function of the first guest material is to the LUMO energy level of the first host material, the less energy is required for electron transfer between the first guest material and the first host material, and the easier it is for electrons from the first guest material to transfer to the first host material. This increases the number of electrons injected from the N-type charge generation layer d41 into the first electron transport layer d316, thereby increasing the probability of electron-hole recombination to produce excitons in the first light-emitting layer d314. Therefore, by limiting the difference between the work function of the first guest material and the LUMO energy level of the first host material, the stacked light-emitting device D provided in the above embodiment increases the probability of electron-hole recombination to produce excitons in the first light-emitting layer d314, thereby improving the luminous efficiency of the stacked light-emitting device D.

[0122] It should be noted that the absolute value of the difference between the work function of the above-mentioned first guest material and the LUMO energy level of the first host material is less than 1.0 electron volt. It can be: the difference between the work function of the first guest material and the LUMO energy level of the first host material is greater than or equal to zero and less than 1.0 electron volt. At this time, the work function of the first guest material is greater than or equal to the LUMO energy level of the first host material; or the difference between the work function of the first guest material and the LUMO energy level of the first host material is greater than negative 1.0 electron volt and less than or equal to zero. At this time, the work function of the first guest material is less than or equal to the LUMO energy level of the first host material.

[0123] In other examples, the first guest material of the N-type charge generation layer d41 is organic. In this case, the absolute value of the difference between the HOMO energy level of the first guest material and the LUMO energy level of the first host material is less than 1.0 electron volt.

[0124] In the above embodiment, the first guest material functions by donating electrons from the first guest material to the first host material, enabling the electrons to be transported through the first host material within the N-type charge generation layer d41 and injected into the first electron transport layer d316 adjacent to the N-type charge generation layer d41. The closer the HOMO energy level of the first guest material is to the LUMO energy level of the first host material, the less energy required for electron transfer between the first guest material and the first host material, and the easier it is for electrons from the first guest material to transfer to the first host material. This increases the number of electrons injected from the N-type charge generation layer d41 into the first electron transport layer d316, thereby increasing the probability of electron-hole recombination to produce excitons in the first light-emitting layer d314. Therefore, the stacked light-emitting device D provided in the above embodiment increases the probability of electron-hole recombination to produce excitons in the first light-emitting layer d314 by limiting the difference between the HOMO energy level of the first guest material and the LUMO energy level of the first host material, thereby improving the luminous efficiency of the stacked light-emitting device D.

[0125] It should be noted that the absolute value of the difference between the HOMO energy level of the above-mentioned first guest material and the LUMO energy level of the first host material is less than 1.0 electron volt. It can be: the difference between the HOMO energy level of the first guest material and the LUMO energy level of the first host material is greater than or equal to zero and less than 1.0 electron volt. At this time, the HOMO energy level of the first guest material is greater than or equal to the LUMO energy level of the first host material; or the difference between the HOMO energy level of the first guest material and the LUMO energy level of the first host material is greater than negative 1.0 electron volt and less than or equal to zero. At this time, the HOMO energy level of the first guest material is less than or equal to the LUMO energy level of the first host material.

[0126] It should be noted that the disclosed embodiments do not limit the method for obtaining the binary doping structure of the N-type charge generation layer d41. For example, the binary doping structure can be obtained by doping the first guest material into the first host material through ion implantation or diffusion.

[0127] In some embodiments, the absolute value of the difference between the LUMO energy level of the second guest material and the HOMO energy level of the second host material is less than 0.5 electron volts.

[0128] In the above embodiment, the function of the second guest material is to transfer holes from the second guest material to the second host material, enabling the holes to be transported through the second host material within the P-type charge generation layer d42 and injected into the second hole transport layer d322 adjacent to the P-type charge generation layer d42. The closer the LUMO energy level of the second guest material is to the HOMO energy level of the second host material, the less energy is required for hole transfer between the two materials, and the easier it is for holes from the second guest material to transfer to the second host material. This increases the number of holes injected from the P-type charge generation layer d42 into the second hole transport layer d322, thereby increasing the probability of holes and electrons recombining to form excitons in the second light-emitting layer d324. Therefore, the stacked light-emitting device D provided in the above embodiment increases the probability of holes and electrons recombining to form excitons in the second light-emitting layer d324 by limiting the difference between the LUMO energy level of the second guest material and the HOMO energy level of the second host material, thereby improving the luminous efficiency of the stacked light-emitting device D.

[0129] It should be noted that the absolute value of the difference between the LUMO energy level of the above-mentioned second guest material and the HOMO energy level of the second host material is less than 0.5 electron volts. It can be: the difference between the LUMO energy level of the second guest material and the HOMO energy level of the second host material is greater than or equal to zero and less than 0.5 electron volts. At this time, the LUMO energy level of the second guest material is greater than or equal to the HOMO energy level of the second host material; or, the difference between the LUMO energy level of the second guest material and the HOMO energy level of the second host material is greater than negative 0.5 electron volts and less than or equal to zero. At this time, the LUMO energy level of the second guest material is greater than or equal to the HOMO energy level of the second host material.

[0130] It should be noted that the present embodiment does not limit the method for obtaining the dual-doping structure of the P-type charge generation layer d42. For example, the dual-doping structure can be obtained by doping the second guest material into the second host material through ion implantation or diffusion.

[0131] In the above embodiments, the limitations on the physical parameters of the materials constituting the various structures of the stacked connecting layer d4 (for example, the limitation on the absolute value of the difference between the HOMO energy level of the second host material and the HOMO energy level of the first host material) are primarily described. The following describes exemplary materials that meet these limitations on physical parameters.

[0132] In some embodiments, the first host material of the N-type charge generation layer d41 has a conjugated segment in its structure; the conjugated segment has at least two benzene rings, and all the benzene rings in the conjugated segment are π-π conjugated structures.

[0133] In this embodiment, the first host material of the N-type charge generation layer d41 has a conjugated segment in its structure. Based on this, since the electron cloud overlap between molecules in the conjugated structure is relatively large, it facilitates the hopping transmission of electrons between molecules. Therefore, the stacked light-emitting device D provided in the embodiment of the present disclosure, by using a material having this conjugated segment in its structure as the host material of the N-type charge generation layer d41, can improve the smoothness of electron transmission in the N-type charge generation layer d41, that is, improve the electron mobility of the N-type charge generation layer d41, thereby improving the efficiency of electron transmission through the N-type charge generation layer d41 to the electron transport layer d316, and thus improving the luminous efficiency of the stacked light-emitting device D.

[0134] It should be noted that the present disclosure does not impose any restriction on the number of benzene rings contained in the above-mentioned conjugated segment, as long as all the benzene rings therein are in a π-π conjugated structure.

[0135] [Corrected 12.09.2024 according to Rule 26] In some examples, the conjugated fragment has two benzene rings, and the two benzene rings are in a π-π conjugated structure. In this case, the conjugated fragment is a naphthalene fragment, and its chemical formula is C 10 H8, the structural formula is

[0136] [Corrected 12.09.2024 according to Rule 26] In other examples, the conjugated fragment has three benzene rings, and the three benzene rings are in a π-π conjugated structure. In this case, the conjugated fragment is anthracene fragment, and its chemical formula is C 14 H 10 , the structural formula is

[0137] [Corrected 12.09.2024 according to Rule 26] In some other examples, the conjugated segment has five benzene rings, and the five benzene rings are π-π conjugated structures. In this case, the conjugated segment is a fragment of pentacene, and its chemical formula is C 22 H 14 , the structural formula is

[0138] It should be noted that the structure of the first host material of the N-type charge generation layer d41 further has at least one substituent connected to the conjugated segment.

[0139] In some examples, the at least one substituent is independently selected from hydrogen, deuterium, halogen, substituted or unsubstituted C6 to C 60 aryl, substituted or unsubstituted C6~C 60 Heteroaryl, substituted or unsubstituted C1~C 20 Alkyl, substituted or unsubstituted C3~C 20Cycloalkyl, substituted or unsubstituted C1~C 20 Heteroalkyl, substituted or unsubstituted C7~C 30 Aralkyl, substituted or unsubstituted C1~C 20 Alkoxy and substituted or unsubstituted C6~C 30 of aryloxy.

[0140] In some embodiments, at least one substituent of the conjugated segment has a phosphorus-oxy group (P=O group).

[0141] In this embodiment, the structure of the first host material of the N-type charge generation layer d41 has a phosphorus oxygen group (P=O group). On this basis, since the phosphorus oxygen group is a strong electron-withdrawing group (a strong electron-withdrawing group is a substituent that externally exhibits a positive electric field and tends to attract electrons), the stacked light-emitting device D provided in the embodiment of the present disclosure uses a material having a phosphorus oxygen group in its structure as the first host material. This can enhance the electron injection capability of the N-type charge generation layer d41, thereby further improving the electron mobility of the N-type charge generation layer d41, and further improving the luminous efficiency of the stacked light-emitting device D.

[0142] [Corrected 16.04.2024 according to Rule 26] In some embodiments, the first host material of the N-type charge generation layer d41 has a structure as shown in Formula (I):

[0143] Wherein, R1, R2, R3 and R4 are independently selected from hydrogen, deuterium, halogen, substituted or unsubstituted C6~C 60 aryl, substituted or unsubstituted C6~C 60 Heteroaryl, substituted or unsubstituted C1~C 20 Alkyl, substituted or unsubstituted C3~C 20 Cycloalkyl, substituted or unsubstituted C1~C 20 Heteroalkyl, substituted or unsubstituted C7~C 30 Aralkyl, substituted or unsubstituted C1~C 20 Alkoxy, substituted or unsubstituted C6~C 30 Any one of the aryloxy groups and the structures shown in formula (II).

[0144] [Corrected 16.04.2024 according to Rule 26] wherein at least one of R1, R2, R3 and R4 has a structure of formula (II):

[0145] Here, * indicates the site of attachment to the carbon atom.

[0146] L1 is selected from: single bond, substituted or unsubstituted C6~C 60aryl, substituted or unsubstituted C6~C 60 Heteroaryl, substituted or unsubstituted C1~C 20 Alkyl, substituted or unsubstituted C3~C 20 Cycloalkyl, substituted or unsubstituted C1~C 20 Heteroalkyl, substituted or unsubstituted C7~C 30 Aralkyl, substituted or unsubstituted C1~C 20 Alkoxy, substituted or unsubstituted C6~C 30 Any of the aryloxy groups.

[0147] X1 and X2 are each independently selected from hydrogen, deuterium, halogen, substituted or unsubstituted C6-C 60 aryl, substituted or unsubstituted C6~C 60 Heteroaryl, substituted or unsubstituted C1~C 20 Alkyl, substituted or unsubstituted C3~C 20 Cycloalkyl, substituted or unsubstituted C1~C 20 Heteroalkyl, substituted or unsubstituted C7~C 30 Aralkyl, substituted or unsubstituted C1~C 20 Alkoxy, substituted or unsubstituted C6~C 30 Any of the aryloxy groups.

[0148] [Corrected 12.09.2024 according to Rule 26] In this embodiment, the first host material of the N-type charge generation layer d41 has a structure as shown in formula (I), that is, the structure of the first host material contains anthracene fragment (molecular formula C 14 H 10 , the structural formula is ), which is a large conjugated rigid structure. On this basis, since the electron cloud overlap between molecules of the conjugated structure is large, it is conducive to the jumping transmission of electrons between molecules. Therefore, the stacked light-emitting device D provided by the embodiment of the present disclosure adopts a material containing fragmented anthracene as the main material of the N-type charge generation layer d41. It can improve the smoothness of electron transmission in the N-type charge generation layer d41, that is, improve the electron mobility of the N-type charge generation layer d41, thereby improving the efficiency of electron transmission through the N-type charge generation layer d41 to the electron transport layer d316, and then improve the luminous efficiency of the stacked light-emitting device D. In addition, at least one of the substituent groups R1, R2, R3 and R4 on the first main material of the N-type charge generation layer d41 has a structure of formula (II), that is, the structure of the first main material contains a phosphorus oxygen group (P=O group). On this basis, since the phosphorus oxygen group is a strong electron-withdrawing group, the stacked light-emitting device D provided in the embodiment of the present disclosure can enhance the electron injection ability of the N-type charge generation layer d41 by using a material with a phosphorus oxygen group in the structure as the first main material, thereby further improving the electron mobility of the N-type charge generation layer d41, and then improving the luminous efficiency of the stacked light-emitting device D.

[0149] It should be noted that the embodiments of the present disclosure do not limit the substitution sites of R3 and R4.

[0150] [Corrected 12.09.2024 according to Rule 26] For example, the first host material has a structure represented by the following formula (IV):

[0151] [Corrected 12.09.2024 according to Rule 26] Alternatively, the first host material has a structure represented by the following formula (V):

[0152] In some embodiments, at least one of R3 and R4 has a structure as shown in formula (II) above.

[0153] In the stacked light-emitting device D provided in the above embodiment, by using a material having a structure as shown in formula (II) in the tail group (R3 and / or R4) (the structure of the tail group contains a phosphorus oxygen group) as the first main material, the electron injection ability of the N-type charge generation layer d41 can be further enhanced, thereby further improving the electron mobility of the N-type charge generation layer d41, and then improving the luminous efficiency of the stacked light-emitting device D.

[0154] In some embodiments, R3 and R4 both have the structure shown in the above formula (II).

[0155] In the stacked light-emitting device D provided in the above embodiment, by using a material whose tail groups (R3 and R4) both have a structure as shown in formula (II) (the structure of the tail groups contains a phosphorus oxygen group) as the first main material, the electron injection ability of the N-type charge generation layer d41 can be further enhanced, thereby further improving the electron mobility of the N-type charge generation layer d41, and then improving the luminous efficiency of the stacked light-emitting device D.

[0156] [Corrected 16.04.2024 according to Rule 26] In some embodiments, the first host material has a structure as shown in any one of Formulas (1-1) to (1-10):

[0157] It should be noted that the materials represented by the above formulas (1-1) to (1-10) are only examples of the first host material, and any material satisfying the above formula (I) can be used as the first host material in the embodiments of the present disclosure.

[0158] In the above embodiments, when the first main material has a structure as shown in the above formulas (1-1) to (1-10), the structure of the tail group (R3 and / or R4) of the first main material contains a phosphorus oxygen group, which can further enhance the electron injection ability of the N-type charge generation layer d41, thereby further improving the electron mobility of the N-type charge generation layer d41, and further improving the luminous efficiency of the stacked light-emitting device D.

[0159] In some examples, the method for preparing the material represented by the above formula (1-1) may include S11 and S12.

[0160] [Corrected 16.04.2024 according to Rule 26] S11. A 500 mL flask was filled with argon. 3.06 g of the starting material 1 represented by Formula A and 3.23 g of the starting material 2 represented by Formula B were added to the flask. 0.236 g of tetrakis(triphenylphosphine)palladium, 20 mL of 1,2-dimethoxyethane, 20 mL of toluene, and 20 mL of a 2M aqueous sodium carbonate solution (i.e., 20 mL of a sodium carbonate solution having a molar concentration of 2 mol / L) were then added to the flask. The mixture was heated to 150° C. and refluxed for 10 hours. The product obtained after the reflux reaction was cooled to room temperature, and the precipitated solid was filtered. The filtered solid was then washed with water and methanol and recrystallized from toluene to obtain Intermediate 1 represented by Formula C.

[0161] [Corrected 16.04.2024 according to Rule 26] The reaction equation of S11 is as follows:

[0162] [Corrected on 16.04.2024 according to Rule 26] S12. In a three-necked flask with a capacity of 500 mL, nitrogen is introduced, and 0.02 mol of intermediate 1, 0.02 mol of raw material 3 having a structure as shown in Formula D, 0.002 mol of dimethylformamide (DMF) and 0.002 mol of palladium acetate are charged into the three-necked flask and stirred; then 0.01 mol of K3PO4 aqueous solution is charged into the flask, heated to 150°C, and refluxed for 24 hours, with sampling point plates taken until the reaction is judged to be complete; the product obtained by the above reflux reaction is cooled to room temperature, extracted with dichloromethane, and the obtained extract is dried over anhydrous sodium sulfate, the precipitated solid after drying is filtered out, and the obtained filtrate is rotary evaporated, and finally purified using a silica gel column to obtain the phosphorus oxy derivative represented by the above formula (1-1).

[0163] [Corrected 16.04.2024 according to Rule 26] The reaction equation of S12 is as follows:

[0164] It should be noted that since the materials represented by the above formulas (1-1) to (1-10) are phosphorus-oxygen derivatives with the same general formula, the preparation methods of the materials represented by the above formulas (1-2) to (1-10) are similar to the preparation methods of the materials represented by formula (1-1), and are not described in detail here.

[0165] In some examples, the first guest material may be an organic compound, a metal (e.g., an alkali metal), or a metal-containing compound containing a strong electron-donating group. The strong electron-donating group is a substituent that exhibits a negative electric field and tends to donate electrons.

[0166] For example, the first guest material can be selected from octyl crystal violet (LCV), lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), francium (Fr), magnesium (Mg), calcium (Ca), ytterbium (Yb) or lithium fluoride (LiF).

[0167] When the N-type charge generation layer d41 of the stacked light-emitting device D is composed of the first host material and the first guest material provided in the above embodiment, it can meet the above-mentioned physical parameter requirement of "the absolute value of the difference between the work function of the first guest material and the LUMO energy level of the first host material is less than 1.0 electron volt" or "the absolute value of the difference between the HOMO energy level of the first guest material and the LUMO energy level of the first host material is less than 1.0 electron volt". This can increase the number of electrons injected from the N-type charge generation layer d41 into the first electron transport layer d316, thereby increasing the probability of electrons and holes in the first light-emitting layer d314 to recombine and produce excitons, and ultimately improve the luminous efficiency of the stacked light-emitting device D.

[0168] In some examples, the P-type charge generation layer d42 has a dual-doped structure including a second host material and a second guest material.

[0169] For example, the second host material may be an aromatic amine material, dimethylfluorene, or carbazole material having hole transport properties. For example, the second host material can be selected from 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (TPD), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (BAFLP), 4,4'-bis[N-(9,9-dimethylfluoren-2-yl)-N-phenylamino]biphenyl (DFLDPBi), 4,4'-di(9-carbazolyl)biphenyl (CBP), 9-phenyl-3-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (PCzPA) or 4,4',4"-tris(N-3-methylphenyl-N-phenylamino)triphenylamine (m-MTDATA), etc.

[0170] For example, the second guest material can be an organic material containing a strong electron-withdrawing group. For example, the second guest material can be selected from hexacyanohexaazatriphenylene, 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ), 1,2,3-tris[(cyano)(4-cyano-2,3,5,6-tetrafluorophenyl)methylene]cyclopropane, and the like.

[0171] When the N-type charge generation layer d41 of the stacked light-emitting device D is composed of the first main material and the first guest material provided in the above embodiment, and the P-type charge generation layer d42 is composed of the second main material and the second guest material provided in the above embodiment, it can meet the above-mentioned physical parameter requirement of "the absolute value of the difference between the HOMO energy level of the second main material and the HOMO energy level of the first main material is greater than 0.3 electron volts, and the absolute value of the difference between the LUMO energy level of the second main material and the LUMO energy level of the first main material is greater than 0.1 electron volts", thereby preventing the reverse transmission of electrons and holes generated in the contact area between the N-type charge generation layer and the P-type charge generation layer, and avoiding the quenching of electrons and holes generated in the contact area due to reverse transmission, thereby ensuring the stability of the number of carriers provided by each stacked connection layer d4 to the two adjacent light-emitting units d30, and ultimately improving the luminous efficiency of the stacked light-emitting device.

[0172] In some embodiments, the light-emitting layer d34 in the light-emitting unit d30 is a binary doped structure comprising a third host material and a third guest material. The third host material has a conjugated segment having at least two benzene rings, and all benzene rings in the conjugated segment have a π-π conjugated structure.

[0173] In this embodiment, the stacked light-emitting device D uses a material having the above-mentioned conjugated segment in its structure as the main material of the light-emitting layer d34 (i.e., the third main material). On this basis, since the conjugated segment has at least two benzene rings (aromatic rings) and has the characteristic of high fluorescence quantum yield, the use of a material having the conjugated segment in its structure as the main material of the light-emitting layer d34 can improve the fluorescent luminescence characteristics of the light-emitting layer d34, thereby improving the luminous efficiency of the light-emitting layer d34. In addition, since all the benzene rings in the conjugated segment are π-π conjugated structures, and the electron cloud overlap between molecules of the π-π conjugated structure is large, it is conducive to the hopping transmission of electrons and holes between molecules. Therefore, the use of a material having the conjugated segment in its structure as the main material of the light-emitting layer d34 can improve the smoothness of the transmission of electrons and holes in the light-emitting layer d34, that is, improve the electron mobility and hole mobility of the light-emitting layer d34, thereby promoting the formation of excitons in the light-emitting layer d34, and ultimately improving the luminous efficiency of the stacked light-emitting device D.

[0174] On this basis, the stacked light-emitting device D provided in the embodiment of the present disclosure can also select the first main material as the main material of the N-type charge generation layer d41. At this time, since the stacked light-emitting device D contains at least two light-emitting units d30, and the light-emitting layer d34 of each light-emitting unit d30 uses the third main material as the main material of the light-emitting layer d34, the N-type charge generation layer d41 and the light-emitting layer d34 in the entire stacked light-emitting device D both contain conjugated fragments (that is, a stacked light-emitting device D includes at least three layers of structures containing conjugated fragments). Since the conjugated fragments in the structure of the first main material and the conjugated fragments in the structure of the third main material are both large conjugated rigid aromatic ring structures, the electron mobility of the N-type charge generation layer d41 and the light-emitting layer d34 and the fluorescent luminescence characteristics of the light-emitting layer d34 can be improved. Ultimately, the luminous efficiency of the stacked light-emitting device D can be extended to a greater extent.

[0175] It should be noted that the present disclosure does not impose any restriction on the number of benzene rings contained in the above-mentioned conjugated segment, as long as all the benzene rings therein are in a π-π conjugated structure.

[0176] [Corrected 12.09.2024 according to Rule 26] In some examples, the conjugated fragment has two benzene rings, and the two benzene rings are in a π-π conjugated structure. In this case, the conjugated fragment is a naphthalene fragment, and its chemical formula is C 10H8, the structural formula is

[0177] [Corrected 12.09.2024 according to Rule 26] In other examples, the conjugated fragment has three benzene rings, and the three benzene rings are in a π-π conjugated structure. In this case, the conjugated fragment is anthracene fragment, and its chemical formula is C 14 H 10 , the structural formula is

[0178] [Corrected 12.09.2024 according to Rule 26] In some other examples, the conjugated segment has five benzene rings, and the five benzene rings are π-π conjugated structures. In this case, the conjugated segment is a fragment of pentacene, and its chemical formula is C 22 H 14 , the structural formula is

[0179] [Corrected 16.04.2024 according to Rule 26] In some embodiments, the third host material has a structure as shown in formula (III):

[0180] Wherein, A1 and A2 are independently selected from hydrogen, deuterium, halogen, substituted or unsubstituted C6~C 60 aryl, substituted or unsubstituted C6~C 60 Heteroaryl, substituted or unsubstituted C1~C 20 Alkyl, substituted or unsubstituted C3~C 20 Cycloalkyl, substituted or unsubstituted C1~C 20 Heteroalkyl, substituted or unsubstituted C7~C 30 Aralkyl, substituted or unsubstituted C1~C 20 Alkoxy, substituted or unsubstituted C6~C 30 Any of the aryloxy groups.

[0181] [Corrected 12.09.2024 according to Rule 26] The stacked light emitting device D provided in the above embodiment is selected to contain anthracene fragment (molecular formula C 14 H 10 , the structural formula is ) as the main material of the light-emitting layer d34 (i.e., the third main material). On this basis, since anthracene is a large conjugated aromatic ring structure and has the characteristics of high fluorescence quantum yield, the use of a material containing anthracene as the main material of the light-emitting layer d34 (i.e., the third main material) can enhance the fluorescence luminescence characteristics of the light-emitting layer d34, thereby enhancing the luminous efficiency of the light-emitting layer d34. In addition, since the electron cloud overlap between molecules of the conjugated structure is large, it is conducive to the jumping transmission of electrons between molecules. Therefore, the use of a material containing anthracene as the main material of the light-emitting layer d34 can enhance the smoothness of electron transmission in the light-emitting layer d34, that is, enhance the electron mobility of the light-emitting layer d34, thereby promoting the formation of excitons in the light-emitting layer d34, and ultimately enhancing the luminous efficiency of the stacked light-emitting device D.

[0182] It should be noted that the present disclosure does not limit the method for obtaining the binary doping structure of the light-emitting layer d34. For example, the binary doping structure can be obtained by doping the third guest material into the third host material through ion implantation or diffusion.

[0183] [Corrected 16.04.2024 according to Rule 26] In some embodiments, the third host material has a structure as shown in any one of Formulas (3-1) to (3-12):

[0184] It should be noted that the materials represented by the above formulas (3-1) to (3-12) are only examples of the third host material, and any material that satisfies the above formula (III) can be used as the third host material in the embodiments of the present disclosure.

[0185] In the above embodiments, when the third host material has a structure as shown in any one of Formulas (3-1) to (3-12), the third host material contains more aromatic ring structures, which is beneficial to improving the fluorescent luminescence properties of the light-emitting layer d34.

[0186] In some examples, the method for preparing the material represented by the above formula (3-2) may include: S21.

[0187] [Corrected 16.04.2024 according to Rule 26] S21. Argon is introduced into a 500 mL flask, and 3.2 g of the raw material 4 having the structure represented by Formula E, 2.9 g of 2-bromonaphthalene, 0.23 g of tetrakistriphenylphosphine palladium, 20 mL of a 2M sodium carbonate aqueous solution, 20 mL of 1,2-dimethoxyethane and 25 mL of toluene are placed into the flask, and the flask is heated to 150°C and refluxed for 10 hours; the product obtained after the reflux reaction is cooled to room temperature, and the precipitated solid is filtered; then, the filtered solid is washed with water and methanol, and then recrystallized from toluene to obtain the material represented by the above formula (3-2).

[0188] [Corrected 16.04.2024 according to Rule 26] The reaction equation of S21 is as follows:

[0189] It should be noted that since the materials represented by the above formulas (3-1) to (3-12) have the same general formula, the preparation methods of the materials represented by formula (3-1) and formulas (3-3) to (3-12) are similar to the preparation method of the material represented by formula (3-1), and will not be described in detail here.

[0190] In some examples, the third guest material may be 4,4′-[1,4-phenylenedi-(1E)-2,1-ethylenediyl]bis[N,N-diphenylaniline] (DSA-ph).

[0191] When the light-emitting layer d34 of the stacked light-emitting device D is composed of the third main material and the third guest material provided in the above embodiment, it is beneficial to improve the electron mobility in the light-emitting layer d34, thereby increasing the probability of electrons and holes in the light-emitting layer d34 to recombine and produce excitons, and ultimately improving the luminous efficiency of the stacked light-emitting device D.

[0192] It should be noted that the embodiment of the present disclosure does not limit the materials constituting the first hole injection layer d311, the first hole transport layer d312, the first electron blocking layer d313, the first hole blocking layer d315 and the first electron transport layer d316 in the above-mentioned first light-emitting unit d31.

[0193] In some examples, the material of the first hole injection layer d311 may be a dopant of a hole transport material and an organic material containing a strong electron-withdrawing group. Here, the hole transport material is an organic material having hole transport properties.

[0194] The hole transport material may be selected from aromatic amine materials, dimethylfluorene or carbazole materials having hole transport properties. For example, the hole transport material may be selected from 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (TPD), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (BAFLP), 4,4'-bis[N-(9,9-dimethylfluoren-2-yl)-N-phenylamino]biphenyl (DFLDPBi), 4,4'-di(9-carbazolyl)biphenyl (CBP), 9-phenyl-3-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (PCzPA), or 4,4',4"-tris(N-3-methylphenyl-N-phenylamino)triphenylamine (m-MTDATA).

[0195] The organic material containing a strong electron-withdrawing group can be selected from hexacyanohexaazatriphenylene, 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ), 1,2,3-tris[(cyano)(4-cyano-2,3,5,6-tetrafluorophenyl)methylene]cyclopropane, and the like.

[0196] It should be noted that at least one of the above-mentioned first hole transport layer d312 and the first electron blocking layer d313 can also be formed by the above-mentioned hole transport material.

[0197] In some examples, the first hole blocking layer d315 and the first electron transport layer d316 can both be formed of aromatic heterocyclic compounds. For example, the materials constituting the first hole blocking layer d315 and the first electron transport layer d316 can be imidazole derivatives (e.g., benzimidazole derivatives, imidazopyridine derivatives, benzimidazolephenanthridine derivatives, etc.), oxazine derivatives (e.g., pyrimidine derivatives, triazine derivatives, etc.), quinoline derivatives, isoquinoline derivatives, phenanthroline derivatives, etc., including compounds containing nitrogen-containing six-membered ring structures and compounds having phosphine oxide-based substituents on the heterocyclic ring. For example, 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (OXD-7), 3-(4-tert-butylphenyl)-4-phenyl-5-(4-biphenyl)-1,2,4-triazole (TAZ), 3-(4-tert-butylphenyl)-4-(4-ethylphenyl)-5-( dopants such as 4-biphenyl-1,2,4-triazole (p-EtTAZ), bathophenanthroline (BPhen), 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline (BCP), 4,4'-bis(5-methylbenzoxazol-2-yl)stilbene (BzOs), 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBi) and 8-hydroxyquinoline-lithium (Liq).

[0198] Similarly, the embodiments of the present disclosure do not limit the materials constituting the second hole transport layer d322, the second electron blocking layer d323, the second hole blocking layer d325, the second electron transport layer d326 and the second electron injection layer d327 in the above-mentioned second light-emitting unit d32.

[0199] In some examples, the selection ranges of materials constituting the second hole transport layer d322, the second electron blocking layer d323, the second hole blocking layer d325 and the second electron transport layer d326 can refer to the selection ranges of materials constituting the first hole transport layer d312, the first electron blocking layer d313, the first hole blocking layer d315 and the first electron transport layer d316 in the above embodiments, and will not be repeated here.

[0200] In some examples, the second electron injection layer d327 can be formed of a metal (e.g., an alkali metal) or a metal-containing compound. For example, the material constituting the second electron injection layer d327 can be selected from lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), francium (Fr), magnesium (Mg), calcium (Ca), ytterbium (Yb), or lithium fluoride (LiF).

[0201] To sum up, the stacked light-emitting device D provided by the embodiment of the present disclosure can ensure the stability of the number of carriers provided by each stacked connecting layer d4 to the two adjacent light-emitting units d30, improve the electron mobility of the N-type charge generation layer d41 and the light-emitting layer d34, increase the probability of electrons and holes in the light-emitting layer d34 to recombine and produce excitons, improve the fluorescent luminescence characteristics of the light-emitting layer d34, and thus improve the luminescence efficiency of the stacked light-emitting device D.

[0202] In order to objectively evaluate the technical effects of the embodiments of the present disclosure, the stacked light-emitting device D provided by the embodiments of the present disclosure will be exemplarily described below through specific examples.

[0203] Example 1

[0204] A stacked light-emitting device D includes a first electrode d1, a first hole injection layer d311, a first hole transport layer d312, a first electron blocking layer d313, a first light-emitting layer d314, a first hole blocking layer d315, a first electron transport layer d316, an N-type charge generation layer d41, a P-type charge generation layer d42, a second hole transport layer d322, a second electron blocking layer d323, a second light-emitting layer d324, a second hole blocking layer d325, a second electron transport layer d326, a second electron injection layer d327 and a second electrode d2 as shown in Figure 6.

[0205] [Corrected 12.09.2024 according to Rule 26] In this embodiment, the material constituting the first electrode d1 is ITO; the material constituting the first hole injection layer d311 is a mixture of m-MTDATA and F4TCNQ; the material constituting the first hole transport layer d312 and the second hole transport layer d322 are both m-MTDATA; the material constituting the first electron blocking layer d313 and the second electron blocking layer d323 are both CBP; the third host material constituting the first light-emitting layer d314 and the second light-emitting layer d324 are both the material represented by the above formula (3-2), and the third guest material constituting the first light-emitting layer d314 and the second light-emitting layer d324 are both the material represented by the formula (VI) material; the materials constituting the first hole blocking layer d315 and the second hole blocking layer d325 are both TPBi; the materials constituting the first electron transport layer d316 and the second electron transport layer d326 are both a mixture of BCP and Liq; the first main material constituting the N-type charge generation layer d41 is the material shown in the above formula (1-1), and the first guest material constituting the N-type charge generation layer d41 is Yb; the second main material constituting the P-type charge generation layer d42 is m-MTDATA, and the second guest material constituting the P-type charge generation layer d42 is F4TCNQ; the material constituting the second electron injection layer d327 is Yb; the material constituting the second electrode d2 is a mixture of Mg and Ag.

[0206] Next, a method for preparing the stacked light-emitting device D will be introduced.

[0207] Taking the first electrode d1 as an anode, for example, a 150nm thick ITO transparent conductive layer can be coated on a glass substrate to serve as the first electrode d1. The glass substrate coated with the ITO transparent conductive layer is ultrasonically treated in a cleaning agent and then rinsed with deionized water. Next, ultrasonic oil removal is performed in a mixed solvent of acetone and ethanol. After baking in a clean environment to completely remove moisture, the substrate is cleaned with ultraviolet light and ozone, and the surface is bombarded with a low-energy cation beam.

[0208] [Corrected 12.09.2024 according to Rule 26] Place the glass substrate prepared above in a vacuum chamber and evacuate to vacuum (1 empty glass substrate -5 ~1 glass substrate -4 After the first electrode d1 is formed, a first hole injection layer d311 is vacuum-evaporated on the first electrode d1. For example, the evaporation rate of the first hole injection layer d311 can be 0.1 nm / s, and the total evaporation thickness can be 10 nm. The first hole injection layer d311 is formed from a mixture of m-MTDATA and F4TCNQ, with a mass ratio of m-MTDATA to F4TCNQ of 97:3. The structural formulas of m-MTDATA and F4TCNQ are shown below.

[0209] A first hole transport layer d312 is evaporated on the first hole injection layer d311. For example, the evaporation rate of the first hole transport layer d312 can be 0.1 nm / s, and the total evaporation thickness can be 20 nm. The first hole transport layer d312 is formed from the above-mentioned m-MTDATA.

[0210] [Corrected 12 / 09 / 2024 in accordance with Rule 26] A first electron blocking layer d313 is evaporated on the first hole transport layer d312. For example, the evaporation rate of the first electron blocking layer d313 can be 0.1 nm / s, and the total evaporated film thickness can be 10 nm. The first electron blocking layer d313 is formed of CBP. The structural formula of CBP is shown below.

[0211] A first light-emitting layer d314 is evaporated on the first electron blocking layer d313. For example, the evaporation rate of the first light-emitting layer d314 can be 0.1 nm / s, and the total thickness of the evaporated film can be 20 nm. The first light-emitting layer d314 is composed of a third host material and a third guest material, and the mass ratio of the third host material to the third guest material is 95:5. The third host material is a material represented by formula (3-2) above. The third guest material is a material represented by formula (VI) above.

[0212] [Corrected 12.09.2024 in accordance with Rule 26] A first hole-blocking layer d315 is evaporated on the first light-emitting layer d314. For example, the evaporation rate of the first hole-blocking layer d315 can be 0.1 nm / s, and the total thickness of the evaporated layer can be 5 nm. The first hole-blocking layer d315 is formed of TPBi. The structural formula of TPBi is shown below.

[0213] [Corrected 12.09.2024 in accordance with Rule 26] A first electron transport layer d316 is evaporated on the first hole-blocking layer d315. For example, the evaporation rate of the first electron transport layer d316 can be 0.1 nm / s, and the total evaporated film thickness can be 30 nm. The first electron transport layer d316 is formed from a mixture of BCP and Liq, with a mass ratio of BCP to Liq of 1:1. The structures of BCP and Liq are shown below.

[0214] An N-type charge generation layer d41 is evaporated on the first electron transport layer d316. For example, the evaporation rate of the N-type charge generation layer d41 can be 0.1 nm / s, and the total evaporation thickness can be 20 nm. The N-type charge generation layer d41 is composed of a first host material and a first guest material, and the mass ratio of the first host material to the first guest material is 99:1. The first host material is the material represented by formula (1-1) above. The first guest material is Yb.

[0215] A P-type charge generation layer d42 is evaporated on the N-type charge generation layer d41. For example, the evaporation rate of the P-type charge generation layer d42 can be 0.1 nm / s, and the total evaporated film thickness can be 9 nm. The P-type charge generation layer d42 is formed from a mixture of m-MTDATA and F4TCNQ, with a mass ratio of m-MTDATA to F4TCNQ of 95:5.

[0216] A second hole transport layer d322 is evaporated on the P-type charge generation layer d42. For example, the evaporation rate of the second hole transport layer d322 can be 0.1 nm / s, and the total evaporation thickness can be 40 nm. The second hole transport layer d322 is formed from the aforementioned m-MTDATA.

[0217] The methods of evaporating a second electron blocking layer d323 on the second hole transport layer d322, evaporating a second light-emitting layer d324 on the second electron blocking layer d323, evaporating a second hole blocking layer d325 on the second light-emitting layer d324, and evaporating a second electron transport layer d326 on the second hole blocking layer d325 can refer to the above embodiments and will not be repeated here.

[0218] A second electron injection layer d327 is evaporated on the second electron transport layer d326. For example, the evaporation rate of the second electron injection layer d327 can be 0.1 nm / s, and the total evaporation thickness can be 1 nm.

[0219] The second electrode d2 is evaporated on the second electron injection layer d327. For example, the evaporation rate of the second electron injection layer d327 can be 0.1 nm / s, and the total evaporation thickness can be 13 nm. The second electron injection layer d327 is formed from a mixture of Mg and Ag, with a mass ratio of Mg to Ag of 1:9.

[0220] After the above evaporation step is completed, resin is used as a packaging material, and ultraviolet rays are used to cure the resin to package the above layers on the substrate, thereby obtaining a stacked light-emitting device D.

[0221] Example 2

[0222] In terms of the selection of materials for each layer constituting the stacked light-emitting device D, the difference between this embodiment and embodiment 1 is that the third main material constituting the first light-emitting layer d314 and the second light-emitting layer d324 are both selected from the materials shown in the above formula (3-8).

[0223] The method for preparing the stacked light emitting device D in this embodiment can refer to the above-mentioned embodiment 1, and will not be described in detail here.

[0224] Example 3

[0225] In terms of the selection of materials for each layer constituting the stacked light-emitting device D, the difference between this embodiment and embodiment 1 is that the first main material constituting the N-type charge generation layer d41 is selected from the material shown in the above formula (1-6).

[0226] The method for preparing the stacked light emitting device D in this embodiment can refer to the above-mentioned embodiment 1, and will not be described in detail here.

[0227] Example 4

[0228] In terms of the selection of materials for each layer constituting the stacked light-emitting device D, the difference between this embodiment and Example 1 is that the third main material constituting the first light-emitting layer d314 and the second light-emitting layer d324 are both selected from the materials shown in the above formula (3-8), and the first main material constituting the N-type charge generation layer d41 is selected from the material shown in the above formula (1-6).

[0229] The method for preparing the stacked light emitting device D in this embodiment can refer to the above-mentioned embodiment 1, and will not be described in detail here.

[0230] Example 5

[0231] In terms of the selection of materials for each layer constituting the stacked light-emitting device D, the difference between this embodiment and embodiment 1 is that the first main material constituting the N-type charge generation layer d41 is selected from the material shown in the above formula (1-7).

[0232] The method for preparing the stacked light emitting device D in this embodiment can refer to the above-mentioned embodiment 1, and will not be described in detail here.

[0233] Example 6

[0234] In terms of the selection of materials for each layer constituting the stacked light-emitting device D, the difference between this embodiment and Example 1 is that the first main material constituting the N-type charge generation layer d41 is selected from the material shown in the above formula (1-7), and the third main material constituting the first light-emitting layer d314 and the second light-emitting layer d324 are both selected from the material shown in the above formula (3-8).

[0235] The method for preparing the stacked light emitting device D in this embodiment can refer to the above-mentioned embodiment 1, and will not be described in detail here.

[0236] Comparative Example 1

[0237] In the comparative light emitting device D ref In terms of the material selection of each layer, compared with Example 1, the difference of this comparative example is that the first main material constituting the N-type charge generation layer d41 is BCP.

[0238] In this comparative example, the light emitting device D ref The preparation method can refer to the above-mentioned Example 1 and will not be described in detail here.

[0239] Comparative Example 2

[0240] [Corrected 12.09.2024 according to Rule 26] In the composition of the comparative light emitting device D ref In terms of the selection of materials for each layer, compared with Example 1, the difference of this comparative example is that the third host material constituting the first light-emitting layer d314 and the second light-emitting layer d324 are both selected from materials with a structure as shown in formula (VII).

[0241] In this comparative example, the light emitting device D ref The preparation method can refer to the above-mentioned Example 1 and will not be described in detail here.

[0242] Comparative Example 3

[0243] In the comparative light emitting device D ref In terms of the material selection of each layer, compared with Example 1, the difference of this comparative example is that the first main material constituting the N-type charge generation layer d41 is BCP, and the third main material constituting the first light-emitting layer d314 and the second light-emitting layer d324 are both selected from the above-mentioned structure as shown in formula (VII).

[0244] Next, in conjunction with Table 1, the stacked light emitting devices D provided by the specific embodiments of the present disclosure (the above embodiments 1 to 6) and the comparative light emitting devices D provided by the comparative examples (the above comparative examples 1 to 3) are compared. ref Perform performance comparison.

[0245] Table 1

[0246] It should be noted that the percentages of voltage, EQE, and LT95 in Table 1 are calculated based on the measured data of Comparative Example 1. That is, the voltage data for each comparative example or embodiment in Table 1 were calculated using the specific value of the voltage measured in Comparative Example 1 as the denominator and the specific value of the voltage measured in each comparative example or embodiment as the numerator; the EQE data for each comparative example or embodiment in Table 1 were calculated using the specific value of the EQE measured in Comparative Example 1 as the denominator and the specific value of the EQE measured in each comparative example or embodiment as the numerator; and the LT95 data for each comparative example or embodiment in Table 1 were calculated using the specific value of the LT95 measured in Comparative Example 1 as the denominator and the specific value of the LT95 measured in each comparative example or embodiment as the numerator.

[0247] Wherein, N-CGL represents the stacked light emitting device D provided in the specific embodiment or the stacked light emitting device D in the comparative example. ref The host material of the N-type charge generation layer d41; EML host represents the stacked light emitting device D provided in the specific embodiment or the stacked light emitting device D in the comparative example ref The host material of the light-emitting layer in each light-emitting unit is shown in Table 1. The voltage in Table 1 is the driving voltage of the stacked light-emitting device; the external quantum efficiency (EQE) reflects the luminous efficiency of the stacked light-emitting device; and LT95 represents the time it takes for the brightness of the stacked light-emitting device to drop from the initial brightness to 95% of the initial brightness, reflecting the service life of the stacked light-emitting device.

[0248] According to the four sets of data in Table 1, namely, Comparative Example 1, Example 1, Example 3 and Example 5, it can be seen that when the third main material of the light-emitting layer d34 is consistent, selecting the material provided in the embodiment of the present disclosure as the first main material of the N-type charge generation layer d41 can reduce the driving voltage of the stacked light-emitting device D, improve the luminous efficiency of the stacked light-emitting device D, and extend the service life of the stacked light-emitting device D.

[0249] According to the three sets of data in Table 1, namely Comparative Example 2, Example 1 and Example 2, it can be seen that when the first main material of the N-type charge generation layer d41 is consistent, selecting the material provided in the embodiment of the present disclosure as the third main material of the light-emitting layer d34 can reduce the driving voltage of the stacked light-emitting device D, improve the luminous efficiency of the stacked light-emitting device D, and extend the service life of the stacked light-emitting device D.

[0250] According to the seven sets of data in Table 1, namely, Comparative Example 3, Example 1, Example 2, Example 3, Example 4, Example 5 and Example 6, it can be seen that when the material provided in the embodiment of the present disclosure is selected as the first main material of the N-type charge generation layer d41, the material provided in the embodiment of the present disclosure is selected as the third main material of the light-emitting layer d34, which can significantly reduce the driving voltage of the stacked light-emitting device D, improve the luminous efficiency of the stacked light-emitting device D, and extend the service life of the stacked light-emitting device D.

[0251] Some embodiments of the present disclosure provide another light-emitting device D1. As shown in FIG7 , the light-emitting device D1 includes a first electrode d1, a second electrode d2, and at least one light-emitting unit d30. The at least one light-emitting unit d30 is disposed between the first electrode d1 and the second electrode d2. The light-emitting unit d30 includes a light-emitting layer d34. The light-emitting layer d34 has a binary doped structure comprising a third host material and a third guest material. The third host material has a conjugated segment having at least two benzene rings, and all benzene rings in the conjugated segment have a π-π conjugated structure.

[0252] The light-emitting device D1 provided in the embodiment of the present disclosure selects a material having a conjugated segment in the structure as the main material of the light-emitting layer d34 (i.e., the third main material). On this basis, since the conjugated segment has at least two benzene rings (aromatic rings) and has the characteristic of high fluorescence quantum yield, the use of a material having the conjugated segment in the structure as the main material of the light-emitting layer d34 can enhance the fluorescent luminescence characteristics of the light-emitting layer d34, thereby enhancing the luminous efficiency of the light-emitting layer d34. In addition, since all the benzene rings in the above-mentioned conjugated segment are π-π conjugated structures, and the electron cloud overlap between the molecules of the π-π conjugated structure is large, it is conducive to the hopping transmission of electrons and holes between molecules. Therefore, the use of a material having the conjugated segment as the main material of the light-emitting layer d34 can enhance the smoothness of the transmission of electrons and holes in the light-emitting layer d34, that is, enhance the electron mobility and hole mobility of the light-emitting layer d34, thereby promoting the formation of excitons in the light-emitting layer d34, and ultimately enhancing the luminous efficiency of the light-emitting device D1.

[0253] It should be noted that the present disclosure does not impose any restriction on the number of benzene rings contained in the above-mentioned conjugated segment, as long as all the benzene rings therein are in a π-π conjugated structure.

[0254] [Corrected 12.09.2024 according to Rule 26] In some examples, the conjugated fragment has two benzene rings, and the two benzene rings are in a π-π conjugated structure. In this case, the conjugated fragment is a naphthalene fragment, and its chemical formula is C 10 H8, the structural formula is

[0255] [Corrected 12.09.2024 according to Rule 26] In other examples, the conjugated fragment has three benzene rings, and the three benzene rings are in a π-π conjugated structure. In this case, the conjugated fragment is anthracene fragment, and its chemical formula is C 14 H 10 , the structural formula is

[0256] [Corrected 12.09.2024 according to Rule 26] In some other examples, the conjugated segment has five benzene rings, and the five benzene rings are π-π conjugated structures. In this case, the conjugated segment is a fragment of pentacene, and its chemical formula is C 22 H 14 , the structural formula is

[0257] [Corrected 12.09.2024 according to Rule 26] In some embodiments, the third host material has a structure as shown in Formula (III):

[0258] Wherein, A1 and A2 are independently selected from hydrogen, deuterium, halogen, substituted or unsubstituted C6~C 60 aryl, substituted or unsubstituted C6~C 60 Heteroaryl, substituted or unsubstituted C1~C 20 Alkyl, substituted or unsubstituted C3~C 20 Cycloalkyl, substituted or unsubstituted C1~C 20 Heteroalkyl, substituted or unsubstituted C7~C 30 Aralkyl, substituted or unsubstituted C1~C 20 Alkoxy, substituted or unsubstituted C6~C 30 Any of the aryloxy groups.

[0259] [Corrected 12.09.2024 according to Rule 26] In this example, a fragment containing anthracene (molecular formula C 14 H 10 , the structural formula is ) as the main material of the light-emitting layer d34 (i.e., the third main material mentioned above). On this basis, since the fragment anthracene is a large conjugated aromatic ring structure with a high fluorescence quantum yield, the use of a material containing fragment anthracene as the main material of the light-emitting layer d34 can enhance the fluorescent luminescence characteristics of the light-emitting layer d34, thereby enhancing the luminous efficiency of the light-emitting layer d34. In addition, since the electron cloud overlap between molecules of the conjugated structure is large, it is conducive to the jumping transmission of electrons between molecules. Therefore, the use of a material containing fragment anthracene as the main material of the light-emitting layer d34 can enhance the smoothness of electron transmission in the light-emitting layer d34, that is, enhance the electron mobility of the light-emitting layer d34, thereby promoting the formation of excitons in the light-emitting layer d34, and ultimately enhancing the luminous efficiency of the light-emitting device D1.

[0260] It should be noted that the embodiment of the present disclosure does not limit the number of light-emitting units d30 in the light-emitting device D1.

[0261] In some examples, as shown in FIG7 , the light emitting device D1 includes only one light emitting unit d33 , which can save the manufacturing cost of the light emitting device D1 .

[0262] In this case, along a direction Z away from the first electrode d1 , the light emitting device D1 includes the first electrode d1 , the light emitting unit d33 , and the second electrode d2 .

[0263] Among them, along the direction Z away from the first electrode d1, the light-emitting unit d33 includes a first hole injection layer d3111, a first hole transport layer d3121, a first electron blocking layer d3131, a first light-emitting layer d3141, a first hole blocking layer d3151, a first electron transport layer d3161 and a first electron injection layer d3171.

[0264] In other embodiments, the light emitting device D1 includes two or more light emitting units d30. In this case, the light emitting device D1 is a stacked light emitting device, which can improve the light emitting efficiency of the light emitting device D1 and extend the service life of the light emitting device D1.

[0265] In this case, taking the light emitting device D1 including two light emitting units d30 as an example, the structure of the light emitting device D1 can refer to FIG. 6 .

[0266] The structure and material selection range of each layer in the above-mentioned light-emitting unit d30 can refer to the above-mentioned embodiment and will not be repeated here.

[0267] [Corrected 12.09.2024 according to Rule 26] In some embodiments, the third host material has a structure as shown in any one of Formulas (3-1) to (3-12):

[0268] In the above embodiments, when the third host material has a structure as shown in any one of Formulas (3-1) to (3-12), the third host material contains more aromatic ring structures, which is beneficial to improving the fluorescent luminescence properties of the light-emitting layer d34.

[0269] In some examples, the light-emitting layer d34 is a binary doped structure including a third host material and a third guest material. For example, the third guest material can be the DSA-ph or the material represented by formula (VI).

[0270] When the light-emitting layer d34 of the light-emitting device D1 is composed of the third host material and the third guest material provided in the above embodiment, it is beneficial to improve the electron mobility in the light-emitting layer d34, thereby increasing the probability of electrons and holes in the light-emitting layer d34 to recombine and produce excitons, and ultimately improving the luminous efficiency of the light-emitting device D1.

[0271] It should be noted that the present embodiment does not limit the method for obtaining the binary doping structure of the light-emitting layer d34. For example, the binary doping structure can be obtained by doping the third guest material into the third host material through ion implantation or diffusion.

[0272] Some embodiments of the present disclosure provide a display substrate 111. The display substrate 111 includes the substrate 1 as described above, a circuit structure layer 2 disposed on the substrate 1, a light emitting structure layer 3 disposed on a side of the circuit structure layer 2 away from the substrate 1, and an encapsulation layer 4 disposed on a side of the light emitting structure layer 3 away from the substrate 1.

[0273] The circuit structure layer 2 includes multiple pixel drive circuits 10. The light-emitting structure layer 3 includes multiple light-emitting devices, each connected to one pixel drive circuit 10; at least one light-emitting device D is a stacked light-emitting device D as described in any of the above embodiments, or a light-emitting device D1 as described in any of the above embodiments. The encapsulation layer 4 encapsulates the circuit structure layer 2 and the light-emitting structure layer 3 on the substrate 1.

[0274] The beneficial effects that can be achieved by the display substrate 111 provided in the embodiment of the present disclosure are the same as the beneficial effects that can be achieved by the stacked light-emitting device D or the light-emitting device D1 provided in any of the above embodiments, and will not be repeated here.

[0275] Some embodiments of the present disclosure provide a display device 100 including a display substrate 111 as described in any of the above embodiments.

[0276] The beneficial effects that can be achieved by the display device 100 provided by the embodiment of the present disclosure are the same as the beneficial effects that can be achieved by the display substrate 111 provided by any of the above embodiments, and will not be repeated here.

[0277] [Corrected 12.09.2024 according to Rule 26] Some embodiments of the present disclosure provide an organic compound having a structure as shown in formula (III):

[0278] Wherein, A1 and A2 are independently selected from hydrogen, deuterium, halogen, substituted or unsubstituted C6~C 60 aryl, substituted or unsubstituted C6~C 60 Heteroaryl, substituted or unsubstituted C1~C 20 Alkyl, substituted or unsubstituted C3~C 20 Cycloalkyl, substituted or unsubstituted C1~C 20 Heteroalkyl, substituted or unsubstituted C7~C 30 Aralkyl, substituted or unsubstituted C1~C 20 Alkoxy, substituted or unsubstituted C6~C 30 Any of the aryloxy groups.

[0279] [Corrected 12.09.2024 according to Rule 26] The organic matter provided in the embodiment of the present disclosure contains anthracene fragment (molecular formula C 14 H 10 , the structural formula is ), and the substituents A1 and A2 on the anthracene fragment are independently selected from: hydrogen, deuterium, halogen, substituted or unsubstituted C6~C 60 aryl, substituted or unsubstituted C6~C 60 Heteroaryl, substituted or unsubstituted C1~C 20Alkyl, substituted or unsubstituted C3~C 20 Cycloalkyl, substituted or unsubstituted C1~C 20 Heteroalkyl, substituted or unsubstituted C7~C 30 Aralkyl, substituted or unsubstituted C1~C 20 Alkoxy, substituted or unsubstituted C6~C 30 Therefore, the fluorescence quantum yield of the organic matter can be improved, and the smoothness of electron transmission in the organic matter can be improved, thereby improving the electron mobility of the organic matter.

[0280] [Corrected 12.09.2024 according to Rule 26] In some embodiments, the organic compound has any one of the following structures:

[0281] In the above embodiment, the organic matter contains more aromatic ring structures, which is beneficial to further improve its fluorescence quantum yield.

[0282] [Corrected 12.09.2024 according to Rule 26] In summary, the organic matter provided in the embodiments of the present disclosure contains anthracene fragment (molecular formula C 14 H 10 , the structural formula is ), and the substituents A1 and A2 on the anthracene fragment are independently selected from: hydrogen, deuterium, halogen, substituted or unsubstituted C6~C 60 aryl, substituted or unsubstituted C6~C 60 Heteroaryl, substituted or unsubstituted C1~C 20 Alkyl, substituted or unsubstituted C3~C 20 Cycloalkyl, substituted or unsubstituted C1~C 20 Heteroalkyl, substituted or unsubstituted C7~C 30 Aralkyl, substituted or unsubstituted C1~C 20 Alkoxy, substituted or unsubstituted C6~C 30 Any one of the aryloxy groups, therefore, can improve the fluorescence quantum yield and electron mobility of the organic matter.

[0283] The above description is merely a specific embodiment of the present disclosure, but the scope of protection of the present disclosure is not limited thereto. Any changes or substitutions that a person skilled in the art can conceive within the technical scope disclosed in the present disclosure should be included within the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope of protection of the claims.

Claims

1. A stacked light emitting device, comprising: a first electrode; a second electrode; At least two light-emitting units, wherein the at least two light-emitting units are stacked between the first electrode and the second electrode; At least one stacked connection layer, wherein the stacked connection layer is arranged between every two adjacent light-emitting units; the stacked connection layer includes an N-type charge generation layer and a P-type charge generation layer which are stacked; wherein the N-type charge generation layer is a binary doping structure comprising a first host material and a first guest material; the P-type charge generation layer is a binary doping structure comprising a second host material and a second guest material; the absolute value of the difference between the highest occupied molecular orbital energy level of the second host material and the highest occupied molecular orbital energy level of the first host material is greater than 0.3 electron volts, and the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the second host material and the lowest unoccupied molecular orbital energy level of the first host material is greater than 0.1 electron volts.

2. The stacked light emitting device according to claim 1, wherein: The first guest material includes at least one of metal or organic matter; wherein, When the first guest material is the metal, the absolute value of the difference between the work function of the first guest material and the lowest unoccupied molecular orbital energy level of the first host material is less than 1.0 electron volt; In the case where the first guest material is the organic substance, an absolute value of a difference between a highest occupied molecular orbital energy level of the first guest material and a lowest unoccupied molecular orbital energy level of the first host material is less than 1.0 electron volt.

3. The stacked light emitting device according to claim 1 or 2, wherein: An absolute value of a difference between a lowest unoccupied molecular orbital energy level of the second guest material and a highest occupied molecular orbital energy level of the second host material is less than 0.5 electron volts.

4. The stacked light emitting device according to any one of claims 1 to 3, wherein: The first host material has a conjugated segment in its structure; the conjugated segment has at least two benzene rings, and all the benzene rings in the conjugated segment are π-π conjugated structures.

5. The stacked light emitting device according to claim 4, wherein: At least one substituent of the conjugated fragment has a phosphorus oxygen group.

6. [Corrected 16.04.2024 according to Rule 26] A stacked light emitting device according to any one of claims 1 to 4, wherein: The first host material has a structure as shown in formula (I): Wherein, R1, R2, R3 and R4 are each independently selected from: hydrogen, deuterium, halogen, substituted or unsubstituted C6-C 60 aryl, substituted or unsubstituted C6~C 60 Heteroaryl, substituted or unsubstituted C1~C 20 Alkyl, substituted or unsubstituted C3~C 20 Cycloalkyl, substituted or unsubstituted C1~C 20 Heteroalkyl, substituted or unsubstituted C7~C 30 Arylalkyl, substituted or unsubstituted C1~C 20 Alkoxy, substituted or unsubstituted C6~C 30 Any one of the aryloxy groups, and the structures shown in formula (II); wherein at least one of the R1, the R2, the R3 and the R4 has the structure shown in formula (II): Wherein, * indicates the site of attachment to the carbon atom; L1 is selected from: a single bond, a substituted or unsubstituted C6~C 60 aryl, substituted or unsubstituted C6~C 60 Heteroaryl, substituted or unsubstituted C1~C 20 Alkyl, substituted or unsubstituted C3~C 20 Cycloalkyl, substituted or unsubstituted C1~C 20 Heteroalkyl, substituted or unsubstituted C7~C 30 Arylalkyl, substituted or unsubstituted C1~C 20 Alkoxy, substituted or unsubstituted C6~C 30 Any of the aryloxy groups; X1 and X2 are each independently selected from: hydrogen, deuterium, halogen, substituted or unsubstituted C6-C 60 aryl, substituted or unsubstituted C6~C 60 Heteroaryl, substituted or unsubstituted C1~C 20 Alkyl, substituted or unsubstituted C3~C 20 Cycloalkyl, substituted or unsubstituted C1~C 20 Heteroalkyl, substituted or unsubstituted C7~C 30 Arylalkyl, substituted or unsubstituted C1~C 20 Alkoxy, substituted or unsubstituted C6~C 30 Any of the aryloxy groups.

7. The stacked light emitting device according to claim 6, wherein: At least one of the R3 and the R4 has the structure shown in formula (II).

8. The stacked light emitting device according to claim 6, wherein: The R3 and the R4 both have the structure shown in formula (II).

9. [Corrected 16.04.2024 according to Rule 26] A stacked light emitting device according to any one of claims 6 to 8, wherein: The first host material has a structure as shown in any one of formulas (1-1) to (1-10):

10. The stacked light emitting device according to any one of claims 1 to 9, wherein: The light-emitting unit includes a light-emitting layer, which is a binary doping structure including a third host material and a third guest material; the structure of the third host material has a conjugated segment; the conjugated segment has at least two benzene rings, and all the benzene rings in the conjugated segment are π-π conjugated structures.

11. [Corrected 16.04.2024 according to Rule 26] A stacked light emitting device according to claim 10, wherein: The third host material has a structure as shown in formula (III): wherein A1 and A2 are each independently selected from: hydrogen, deuterium, halogen, substituted or unsubstituted C6-C 60 aryl, substituted or unsubstituted C6~C 60 Heteroaryl, substituted or unsubstituted C1~C 20 Alkyl, substituted or unsubstituted C3~C 20 Cycloalkyl, substituted or unsubstituted C1~C 20 Heteroalkyl, substituted or unsubstituted C7~C 30 Arylalkyl, substituted or unsubstituted C1~C 20 Alkoxy, substituted or unsubstituted C6~C 30 Any of the aryloxy groups.

12. [Corrected 16.04.2024 in accordance with Rule 26] A stacked light emitting device according to claim 10, wherein: The third host material has a structure as shown in any one of formulas (3-1) to (3-12):

13. A stacked light emitting device, comprising: a first electrode; a second electrode; At least two light-emitting units, wherein the at least two light-emitting units are stacked between the first electrode and the second electrode; the light-emitting unit comprises a light-emitting layer; At least one stacked connection layer, the stacked connection layer is arranged between every two adjacent light-emitting units; the stacked connection layer includes an N-type charge generation layer and a P-type charge generation layer which are stacked; At least three film layers in the stacked light-emitting device include materials having conjugated segments; the at least three film layers include at least one of the light-emitting layer and the N-type charge generation layer.

14. The stacked light emitting device according to claim 13, wherein: The conjugated segment has at least two benzene rings, and all the benzene rings in the conjugated segment are in a π-π conjugated structure.

15. The stacked light emitting device according to claim 13 or 14, wherein: At least one of the materials having a conjugated segment has a phosphorus oxygen group in at least one substituent of the conjugated segment.

16. The stacked light emitting device according to any one of claims 13 to 15, wherein: At least two film layers in the stacked light-emitting device have different conjugated segments.

17. The stacked light emitting device according to any one of claims 13 to 16, wherein: In the stacked light-emitting device, there are at least two light-emitting layers, and an N-type charge generation layer located between the at least two light-emitting layers, comprising a material having the conjugated segment.

18. The stacked light emitting device according to any one of claims 13 to 17, wherein: All the light-emitting layers of the stacked light-emitting device include at least two light-emitting layers made of the same material.

19. The stacked light emitting device according to any one of claims 13 to 18, wherein: The light-emitting layer includes a binary doping structure including a third host material and a third guest material; the third host material has the conjugated fragment in its structure.

20. [Corrected 16.04.2024 in accordance with Rule 26] A stacked light emitting device according to claim 19, wherein: The third host material has a structure as shown in formula (III): wherein A1 and A2 are each independently selected from: hydrogen, deuterium, halogen, substituted or unsubstituted C6-C 60 aryl, substituted or unsubstituted C6~C 60 Heteroaryl, substituted or unsubstituted C1~C 20 Alkyl, substituted or unsubstituted C3~C 20 Cycloalkyl, substituted or unsubstituted C1~C 20 Heteroalkyl, substituted or unsubstituted C7~C 30 Arylalkyl, substituted or unsubstituted C1~C 20 Alkoxy, substituted or unsubstituted C6~C 30 Any of the aryloxy groups.

21. [Corrected 16.04.2024 in accordance with Rule 26] A stacked light emitting device according to claim 19, wherein: The third host material has a structure as shown in any one of formulas (3-1) to (3-12):

22. The stacked light emitting device according to any one of claims 13 to 21, wherein: The N-type charge generation layer includes a binary doping structure including a first host material and a first guest material; the first host material has the conjugated segment in its structure.

23. The stacked light emitting device according to claim 22, wherein: The P-type charge generation layer is a dual-doping structure including a second host material and a second guest material; The absolute value of the difference between the highest occupied molecular orbital energy level of the second host material and the highest occupied molecular orbital energy level of the first host material is greater than 0.3 electron volts, and the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the second host material and the lowest unoccupied molecular orbital energy level of the first host material is greater than 0.1 electron volts.

24. The stacked light emitting device according to claim 22 or 23, wherein: The first guest material includes at least one of metal or organic matter; wherein, The first guest material includes the metal, and the absolute value of the difference between the work function of the metal included in the first guest material and the lowest unoccupied molecular orbital energy level of the first host material is less than 1.0 electron volt; or, The first guest material includes the organic matter, and an absolute value of a difference between a highest occupied molecular orbital energy level of the organic matter included in the first guest material and a lowest unoccupied molecular orbital energy level of the first host material is less than 1.0 electron volt.

25. The stacked light emitting device according to claim 23, wherein: An absolute value of a difference between a lowest unoccupied molecular orbital energy level of the second guest material and a highest occupied molecular orbital energy level of the second host material is less than 0.5 electron volts.

26. [Corrected 16.04.2024 according to Rule 26] A stacked light emitting device according to any one of claims 22 to 24, wherein: The first host material has a structure as shown in formula (I): Wherein, R1, R2, R3 and R4 are each independently selected from: hydrogen, deuterium, halogen, substituted or unsubstituted C6-C 60 aryl, substituted or unsubstituted C6~C 60 Heteroaryl, substituted or unsubstituted C1~C 20 Alkyl, substituted or unsubstituted C3~C 20 Cycloalkyl, substituted or unsubstituted C1~C 20 Heteroalkyl, substituted or unsubstituted C7~C 30 Arylalkyl, substituted or unsubstituted C1~C 20 Alkoxy, substituted or unsubstituted C6~C 30 Any one of the aryloxy groups, and the structures shown in formula (II); wherein at least one of the R1, the R2, the R3 and the R4 has the structure shown in formula (II): Wherein, * indicates the site of attachment to the carbon atom; L1 is selected from: a single bond, a substituted or unsubstituted C6~C 60 aryl, substituted or unsubstituted C6~C 60 Heteroaryl, substituted or unsubstituted C1~C 20 Alkyl, substituted or unsubstituted C3~C 20 Cycloalkyl, substituted or unsubstituted C1~C 20 Heteroalkyl, substituted or unsubstituted C7~C 30 Arylalkyl, substituted or unsubstituted C1~C 20 Alkoxy, substituted or unsubstituted C6~C 30 Any of the aryloxy groups; X1 and X2 are each independently selected from: hydrogen, deuterium, halogen, substituted or unsubstituted C6-C 60 aryl, substituted or unsubstituted C6~C 60 Heteroaryl, substituted or unsubstituted C1~C 20 Alkyl, substituted or unsubstituted C3~C 20 Cycloalkyl, substituted or unsubstituted C1~C 20 Heteroalkyl, substituted or unsubstituted C7~C 30 Arylalkyl, substituted or unsubstituted C1~C 20 Alkoxy, substituted or unsubstituted C6~C 30 Any of the aryloxy groups.

27. [Corrected 16.04.2024 according to Rule 26] A stacked light emitting device according to claim 26, wherein: The first host material has a structure as shown in any one of formulas (1-1) to (1-10):

28. A light emitting device, comprising: a first electrode; a second electrode; At least one light-emitting unit, the at least one light-emitting unit is disposed between the first electrode and the second electrode; the light-emitting unit includes a light-emitting layer; The light-emitting layer is a binary doping structure comprising a third host material and a third guest material; the third host material has a conjugated segment in its structure; the conjugated segment has at least two benzene rings, and all the benzene rings in the conjugated segment are π-π conjugated structures.

29. [Corrected 16.04.2024 in accordance with Rule 26] A light emitting device according to claim 28, wherein: The third host material has a structure as shown in formula (III): wherein A1 and A2 are each independently selected from: hydrogen, deuterium, halogen, substituted or unsubstituted C6-C 60 aryl, substituted or unsubstituted C6~C 60 Heteroaryl, substituted or unsubstituted C1~C 20 Alkyl, substituted or unsubstituted C3~C 20 Cycloalkyl, substituted or unsubstituted C1~C 20 Heteroalkyl, substituted or unsubstituted C7~C 30 Arylalkyl, substituted or unsubstituted C1~C 20 Alkoxy, substituted or unsubstituted C6~C 30 Any of the aryloxy groups.

30. [Corrected 16.04.2024 as per Rule 26] A light emitting device according to claim 28, wherein: The third host material has a structure as shown in any one of formulas (3-1) to (3-12):

31. A display substrate, comprising: substrate; A plurality of light-emitting devices; wherein at least one of the light-emitting devices is a stacked light-emitting device as described in any one of claims 1 to 27 or a light-emitting device as described in claims 28 to 30; A plurality of pixel driving circuits, used for driving the at least one light emitting device to emit light; as well as The encapsulation layer is used to encapsulate the plurality of light emitting devices and the plurality of pixel driving circuits.

32. [Corrected on 16.04.2024 according to Rule 26] A display device comprising a display substrate as claimed in claim 31.

33. An organic substance having a structure as shown in formula (III): in, A1 and A2 are each independently selected from: hydrogen, deuterium, halogen, substituted or unsubstituted C6-C 60 aryl, substituted or unsubstituted C6~C 60 Heteroaryl, substituted or unsubstituted C1~C 20 Alkyl, substituted or unsubstituted C3~C 20 Cycloalkyl, substituted or unsubstituted C1~C 20 Heteroalkyl, substituted or unsubstituted C7~C 30 Arylalkyl, substituted or unsubstituted C1~C 20 Alkoxy, substituted or unsubstituted C6~C 30 Any of the aryloxy groups.

34. [Corrected 16.04.2024 as per Rule 26] An organic substance according to claim 33, wherein The organic matter has a structure shown in any one of the following formulas (3-1) to (3-12):

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