Light-emitting device, display panel, and display apparatus

Abstract

A light-emitting device, a display panel, and a display apparatus, relating to the technical field of display, and for use in improving the light-emitting efficiency of the light-emitting device and prolonging the service life of the device. The light-emitting device comprises a cathode and an anode oppositely arranged, and at least one light-emitting unit arranged between the cathode and the anode. The light-emitting unit comprises: a light-emitting layer and a first-type functional layer arranged on the side of the light-emitting layer close to the cathode; and the first-type functional layer comprises a first functional layer and a second functional layer. The material of the first functional layer comprises a first functional material. The material of the second functional layer comprises a second functional material. The structure of the first functional material comprises fluorenyl. The structure of the second functional material comprises fluorenyl. The light-emitting device is used for displaying images.

Description

Light-emitting device, display panel, and display apparatus Technical Field

[0001] The present disclosure relates to the field of display technology, and in particular to a light-emitting device, a display panel, and a display apparatus. Background Art

[0002] OLED (Organic Light Emitting Diode) display panels are widely used in display screens such as mobile phones, tablets, and car displays due to their advantages such as full solid-state, fast response speed, and wide operating temperature range.

[0003] Summary of the Invention

[0004] In one aspect, a light-emitting device is provided. The light-emitting device includes a cathode and an anode disposed opposite each other, and at least one light-emitting unit disposed between the cathode and the anode. The light-emitting unit includes a light-emitting layer and a first type of functional layer disposed on the cathode side of the light-emitting layer; the first type of functional layer includes a first functional layer and a second functional layer. The material of the first functional layer includes a first functional material. The material of the second functional layer includes a second functional material. The first functional material includes a fluorene group in its structure. The second functional material also includes a fluorene group in its structure.

[0005] In some embodiments, the first functional layer is closer to the cathode than the second functional layer. The first functional material comprises an azafluorene group.

[0006] In some embodiments, the first functional material is selected from any one of the structures represented by the following general formula (I).

[0007] Among them, X 11 、X 12 、X 13 、X 14 、X 15 、X 16 、X 17 and X 18 are independently selected from C(R a ) and N; X 11 、X 12 、X 13 、X 14 、X 15 、X 16 、X 17 and X 18 Any two of them, the same or different; and X 11 、X 12 、X 13 and X 14 At least one of them is N. 11 、R12 、R 13 、R 14 and R a are the same or different and are independently selected from any one of hydrogen, deuterium, halogen, cyano, nitro, hydroxyl, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 5- to 30-membered heteroaryl, and substituted or unsubstituted 3- to 30-membered heterocyclyl; or may be linked to adjacent groups to form a substituted or unsubstituted 3- to 30-membered ring. 11 Any one selected from a direct bond, a substituted or unsubstituted C3-C30 alkylene group, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted 5- to 30-membered heteroarylene group. A is any one selected from a substituted or unsubstituted C6-C12 aryl group and a substituted or unsubstituted 5- to 12-membered heteroaryl group. 11 Any one selected from 0, 1 and 2. n 12 Select either 0 or 1.

[0008] In some embodiments, the second functional material is selected from any one of the structures represented by the following general formula (II).

[0009] Among them, X 21 、X 22 、X 23 and X 24 are independently selected from C(R b ) and N; X 21 、X 22 、X 23 and X 24 Any two of them, the same or different. 21 、R 22 、R 23 、R 24 and R b are the same or different and are independently selected from any one of hydrogen, deuterium, halogen, cyano, nitro, hydroxyl, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 5- to 30-membered heteroaryl, and substituted or unsubstituted 3- to 30-membered heterocyclyl; or may be linked to adjacent groups to form a substituted or unsubstituted 3- to 30-membered ring. 21Any one selected from a direct bond, a substituted or unsubstituted C3-C30 alkylene group, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted 5- to 30-membered heteroarylene group. Ar1 and Ar2 are the same or different and are independently selected from any one of a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C2-C30 alkenyl group, a substituted or unsubstituted C2-C30 alkynyl group, a substituted or unsubstituted C3-C30 cycloalkyl group, a substituted or unsubstituted C1-C30 alkoxy group, a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted 5- to 30-membered heteroaryl group, and a substituted or unsubstituted 3- to 30-membered heterocyclyl group; or may be linked to an adjacent group to form a substituted or unsubstituted 3- to 30-membered ring. 21 Any one selected from 0, 1 and 2. n 22 Select either 0 or 1.

[0010] In some embodiments, the first functional material is selected from any one of the structures represented by the following general formula (IA).

[0011] Among them, X 31 、X 32 、X 33 、X 34 、X 35 、X 36 、X 37 and X 38 are independently selected from C(R c ) and N; X 31 、X 32 、X 33 、X 34 、X 35 、X 36 、X 37 and X 38 Any two of them, same or different. 31 Selected from direct bond, C(R d R e ), any one of O, S and Se. c 、R d and R ethe same or different, and independently selected from any one of hydrogen, deuterium, halogen, cyano, nitro, hydroxyl, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 5- to 30-membered heteroaryl and substituted or unsubstituted 3- to 30-membered heterocyclyl; or may be connected with adjacent groups to form a substituted or unsubstituted 3- to 30-membered ring.

[0012] In some embodiments, R 11 is phenyl; R 12 It is phenyl.

[0013] In some embodiments, A is selected from any one of the structures represented by the following formula (A1-1), formula (A1-2), formula (A1-3) and formula (A1-4).

[0014] Wherein, # represents the fusion site. g and R h the same or different, and independently selected from any one of hydrogen, deuterium, halogen, cyano, nitro, hydroxyl, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 5- to 30-membered heteroaryl and substituted or unsubstituted 3- to 30-membered heterocyclyl; or may be connected with adjacent groups to form a substituted or unsubstituted 3- to 30-membered ring.

[0015] In some embodiments, A is selected from any one of the structures represented by the following formula (A2), formula (A3), formula (A4) and formula (A5).

[0016] Among them, # represents a fusion site.

[0017] X 41 、X 42 、X 43 、X 44 、X 45 、X 46 、X 51 、X 52 、X 53 、X 54 、X 55 、X 56 、X 71 、X72 、X 73 、X 74 、X 81 、X 82 、X 83 and X 84 are independently selected from C(R f ) and N; X 41 、X 42 、X 43 、X 44 、X 45 、X 46 、X 51 、X 52 、X 53 、X 54 、X 55 、X 56 、X 71 、X 72 、X 73 、X 74 、X 81 、X 82 、X 83 and X 84 Any two of them, same or different. 81 Selected from C(R i R j )、N(R k ), any one of O, S and Se. f 、R i 、R j and R k the same or different, and independently selected from any one of hydrogen, deuterium, halogen, cyano, nitro, hydroxyl, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 5- to 30-membered heteroaryl and substituted or unsubstituted 3- to 30-membered heterocyclyl; or may be connected with adjacent groups to form a substituted or unsubstituted 3- to 30-membered ring.

[0018] In some embodiments, A is selected from any one of the structures shown in general formula (A2). 15 、X 16 、X 17 and X 18 The six-membered ring forms a phenanthroline group.

[0019] In some embodiments, A is selected from any one of the structures shown in general formula (A4). 15 、X16 、X 17 and X 18 The six-membered ring forms a benzodiazinyl group.

[0020] In some embodiments, the second functional material is selected from any one of the structures represented by the following general formula (II-A);

[0021] Among them, X 91 、X 92 、X 93 、X 94 、X 95 、X 96 、X 97 and X 98 are independently selected from C(R n ) and N; X 91 、X 92 、X 93 、X 94 、X 95 、X 96 、X 97 and X 98 Any two of them, same or different. 91 Selected from direct bond, C(R o R p ), any one of O, S and Se. n 、R o and R p the same or different, and independently selected from any one of hydrogen, deuterium, halogen, cyano, nitro, hydroxyl, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 5- to 30-membered heteroaryl and substituted or unsubstituted 3- to 30-membered heterocyclyl; or may be connected with adjacent groups to form a substituted or unsubstituted 3- to 30-membered ring.

[0022] In some embodiments, R 21 is phenyl; R 22 It is phenyl.

[0023] In some embodiments, R 21 is methyl; R 22 It is a methyl group.

[0024] In some embodiments, L 21 The structure is shown in the following structure (IIA).

[0025] Wherein, * indicates the attachment site.

[0026] In some embodiments, X 21 、X 22 、X 23 and X 24 is a substituted or unsubstituted carbon.

[0027] In some embodiments, the first type of functional layer further includes a third functional layer, the third functional layer being located on a side of the first functional layer away from the second functional layer, and the third functional layer comprising a third functional material selected from any one of ytterbium and lithium fluoride.

[0028] In some embodiments, the material of the light-emitting layer includes a host material and a guest material, wherein the guest material is configured to emit blue light.

[0029] In some embodiments, the guest material is selected from any one of a fluorescent material, a phosphorescent material, and a delayed fluorescent material.

[0030] In some embodiments, the light-emitting device includes at least two light-emitting units, the at least two light-emitting units are stacked, and the light-emitting device also includes a charge generation layer located between two adjacent light-emitting units. The material of the second functional layer of each light-emitting unit includes a second functional material.

[0031] In another aspect, a display panel is provided. The display panel includes a plurality of light-emitting devices according to any of the above embodiments and a plurality of pixel driving circuits. Each of the plurality of pixel driving circuits is electrically connected to a light-emitting device and is configured to drive the light-emitting device to emit light.

[0032] In another aspect, a display device is provided. The display device includes a display panel as described in any of the above embodiments and a driver chip. The driver chip is used to drive the display panel to display. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] 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.

[0034] FIG1 is a structural diagram of a display device according to some embodiments;

[0035] FIG2 is a structural diagram of a display panel according to some embodiments;

[0036] FIG3 is a structural diagram of a display panel according to yet other embodiments;

[0037] FIG4 is a structural diagram of a display panel according to yet other embodiments;

[0038] FIG5 is a structural diagram of a display panel according to yet other embodiments;

[0039] FIG6 is a structural diagram of a display panel according to yet other embodiments;

[0040] FIG7 is a structural diagram of a display panel according to some other embodiments;

[0041] FIG8 is a diagram showing the LUMO electron cloud distribution of a first functional material according to some embodiments;

[0042] FIG9 is a HOMO electron cloud distribution diagram of a first functional material according to some embodiments;

[0043] FIG10 is a diagram illustrating electron cloud distribution of T1 holes in a first functional material according to some embodiments;

[0044] FIG11 is an electron cloud distribution diagram of T1 electrons of a first functional material according to some embodiments;

[0045] FIG12 is a diagram showing the LUMO electron cloud distribution of a second functional material according to some embodiments;

[0046] FIG13 is a diagram showing the HOMO electron cloud distribution of a second functional material according to some embodiments;

[0047] FIG14 is a diagram showing electron cloud distribution of T1 holes of a second functional material according to some embodiments;

[0048] FIG. 15 is a diagram illustrating electron cloud distribution of T1 electrons of a second functional material according to some embodiments. DETAILED DESCRIPTION

[0049] 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.

[0050] Unless the context requires otherwise, throughout the specification and claims, the term "comprise" and its other forms, such as the third person singular form "comprises" and the present participle form "comprising", are to be interpreted as open and inclusive, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "example", "specific example" or "some examples" are intended to indicate that the particular features, structures, materials or characteristics associated with the embodiment or example are 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.

[0051] 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.

[0052] “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.

[0053] “A and / or B” includes the following three combinations: A only, B only, and a combination of A and B.

[0054] As used herein, "about," "substantially," or "approximately" includes the stated value and an average value that is within an acceptable range of deviation from the particular value as determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

[0055] As used herein, "parallel", "perpendicular", and "equal" include the situations described and situations similar to the situations described, and the range of the similar situations is within an acceptable deviation range, wherein the acceptable deviation range is as determined by a person of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of the specific quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, wherein the acceptable deviation range of approximate parallelism can be, for example, a deviation within 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, wherein the acceptable deviation range of approximate perpendicularity can also be, for example, a deviation within 5°. "Equal" includes absolute equality and approximate equality, wherein the acceptable deviation range of approximate equality can be, for example, that the difference between the two equals is less than or equal to 5% of either one.

[0056] 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.

[0057] Exemplary embodiments are described herein with reference to cross-sectional and / or plan views that are idealized exemplary drawings. In the drawings, the thickness of layers and the area of ​​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.

[0058] It should be noted that, in the drawings of this disclosure, references to components 1 and 2, for example, and 101 / 100, for example, representing first light-emitting device 101 and light-emitting device 100, for example, may refer to the same component. The above description applies to other similar reference numerals in the drawings.

[0059] As shown in FIG. 1 , some embodiments of the present disclosure provide a display device 300 , which includes a display panel 200 .

[0060] The display device 300 may be, for example, an OLED (Organic Light Emitting Diode) display device 300 .

[0061] 1 , the display device 300 further includes a driver chip 310. The driver chip 310 is used to drive the display panel 200 to perform display.

[0062] In addition, the display device 300 may also include an under-screen camera and an under-screen fingerprint recognition sensor, so that the display device 300 can realize various functions such as taking pictures, recording videos, fingerprint recognition or face recognition.

[0063] The display device 300 can be any display device that displays either motion (e.g., video) or fixed (e.g., still images) and text or images. More specifically, it is contemplated that the display device 300 of the embodiments described herein can be implemented in or associated with a variety of electronic devices, such as (but not limited to) mobile phones, wireless devices, personal data assistants (PDAs), handheld or portable computers, 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., speedometer displays), navigation systems, cockpit controls and / or displays, camera view displays (e.g., displays for rearview cameras in vehicles), electronic photographs, electronic billboards or signs, projectors, architectural structures, packaging, and aesthetic structures (e.g., displays for images of a piece of jewelry), and the like.

[0064] In some embodiments, as shown in FIG2 , the display panel 200 includes a substrate 210 and a light-emitting functional layer 220 disposed on the substrate 210 . The light-emitting functional layer 220 includes a plurality of light-emitting devices 100 . The plurality of light-emitting devices 100 are arranged along a first direction X, and the first direction X is parallel to the plane where the substrate 210 is located.

[0065] For example, the material of the substrate 210 may be a transparent rigid material, such as glass, to realize a rigid substrate display; or the material of the substrate 210 may be a transparent flexible material, such as polyimide, to realize a flexible substrate display.

[0066] In some examples, as shown in FIG2 , the display panel 200 further includes an array layer 230 disposed between the substrate 210 and the light-emitting functional layer 220. The array layer 230 includes a plurality of pixel driving circuits 231, wherein the pixel driving circuits 231 include a plurality of transistors TFT. Each pixel driving circuit 231 is electrically connected to a light-emitting device 100 to drive the light-emitting device 100 to emit light.

[0067] For example, in the display panel 200, the pixel driving circuit 231 can generate a driving current. Each light-emitting device 100 can emit light under the driving action of the driving current generated by the corresponding pixel driving circuit 231. The light emitted by multiple light-emitting devices 100 cooperates with each other, thereby enabling the display panel 200 to achieve a display function.

[0068] In some examples, as shown in Figure 2, the display panel 200 also includes an encapsulation layer 240; in this case, the array layer 230, the light-emitting functional layer 220 and the encapsulation layer 240 are stacked on the substrate 210, and the array layer 230, the light-emitting functional layer 220 and the encapsulation layer 240 are arranged in sequence in a direction away from the substrate 210.

[0069] Exemplarily, the display panel 200 may be an OLED display panel 200. In this case, the encapsulation layer 240 covers the light-emitting device 100, encapsulating the light-emitting device 100 to prevent moisture and oxygen in the external environment from entering the display panel 200 and damaging the organic material in the light-emitting device 100, thereby shortening the life of the OLED display panel 200.

[0070] In some embodiments, as shown in FIG. 2 and FIG. 3 , in the display panel 200 , the light-emitting functional layer 220 further includes a pixel defining layer 221 . The pixel defining layer 221 has a plurality of openings Q. The plurality of light-emitting devices 100 may be arranged in one-to-one correspondence with the plurality of openings Q.

[0071] In some embodiments, as shown in Figures 3 and 4, the plurality of light-emitting devices 100 of the display panel 200 include a first light-emitting device 101, a second light-emitting device 102, and a third light-emitting device 103. Under the action of a driving voltage, the first light-emitting device 101 is configured to emit blue light, the second light-emitting device 102 is configured to emit green light, and the third light-emitting device 103 is configured to emit red light.

[0072] By setting up multiple light-emitting devices 100 including a first light-emitting device 101, a second light-emitting device 102 and a third light-emitting device 103, the brightness (grayscale) of the first light-emitting device 101, the second light-emitting device 102 and the third light-emitting device 103 can be adjusted respectively, and the display of multiple colors can be achieved through color combination and superposition, thereby realizing full-color display of the display panel 200.

[0073] It should be noted that FIG. 4 to FIG. 7 are simplified schematic diagrams obtained after removing the other film layers in the display panel 200 except the film layers related to the light emitting device 100.

[0074] In some embodiments, as shown in FIG2 to FIG7 , the light emitting device 100 includes a stacked anode 11 and a cathode 12 , and at least one light emitting unit 13 disposed between the anode 11 and the cathode 12 . The light emitting unit 13 includes a light emitting layer 131 .

[0075] Based on the above structure, the light-emitting device 100 operates as follows: a circuit (e.g., pixel driver circuit 231) connected to the anode 11 and cathode 12 injects holes into the light-emitting layer 131 using the anode 11, and injects electrons into the light-emitting layer 131 using the cathode 12. The injected electrons and holes form excitons (i.e., electron-hole pairs) in the light-emitting layer 131, which then transition back to the ground state through radiation, emitting photons. Thus, efficient charge generation, effective charge injection, and rapid charge transport are essential for the light-emitting device 100. The charges are either holes or electrons.

[0076] 3 , the anode 11 may be located on a side of the light emitting unit 13 close to the substrate 210, and the cathode 12 may be located on a side of the light emitting unit 13 away from the substrate 210. In other examples, the anode 11 may be located on a side of the light emitting unit 13 away from the substrate 210, and the cathode 12 may be located on a side of the light emitting unit 13 close to the substrate 210.

[0077] For example, the material of the anode 11 may be a transparent oxide, such as indium tin oxide (ITO) or indium zinc oxide (IZO); or, the anode 11 may be a composite electrode, such as ITO / Ag / ITO, Ag / IZO, CNT / ITO, or CNT / IZO, where Ag is silver and CNT is carbon nanotube.

[0078] For example, the material of the cathode 12 may be silver-magnesium alloy or aluminum.

[0079] In some examples, as shown in Figures 3 to 5 , the light-emitting device 100 includes a single light-emitting unit 13. In this case, the light-emitting device 100 is a single-layer light-emitting device 100, and the anode 11, the light-emitting unit 13, and the cathode 12 are stacked along the second direction Y, where the second direction Y intersects the first direction X. In other examples, as shown in Figure 6 , the light-emitting device 100 includes multiple (e.g., two) stacked light-emitting units 13. In this case, the light-emitting device 100 is a stacked light-emitting device 100, and the anode 11, the multiple light-emitting units 13, and the cathode 12 are stacked along the second direction Y.

[0080] Exemplarily, as shown in FIG. 3 to FIG. 6 , the second direction Y is perpendicular to the first direction X.

[0081] In some embodiments, as shown in FIG. 6 , when the light emitting device 100 includes a plurality of light emitting units 13 , the light emitting device 100 further includes a charge generation layer 14 , and the charge generation layer 14 is located between two adjacent light emitting units 13 among the plurality of light emitting units 13 .

[0082] Through the charge generation layer 14, multiple light-emitting units 13 can be sequentially connected in a direction perpendicular to the light-emitting surface (e.g., the second direction Y). Furthermore, the charge generation layer 14 in the stacked OLED light-emitting device 100 not only connects the light-emitting units 13 but also helps improve the efficiency of charge (holes or electrons) generation, significantly impacting the performance of the light-emitting device 100.

[0083] In some examples, as shown in FIG6 , charge generation layer 14 includes an electron generation layer 141 and a hole generation layer 142 stacked together; electron generation layer 141 is closer to anode 11 than hole generation layer 142. Electron generation layer 141 may also be referred to as an N-type charge generation layer, and hole generation layer 142 may also be referred to as a P-type charge generation layer.

[0084] In some embodiments, as shown in Figures 3 to 6, to improve the luminous efficiency of the light-emitting device 100, the light-emitting unit 13 further includes a hole transport functional layer 132, which is located on the side of the light-emitting layer 131 close to the anode 11 and in contact with the light-emitting layer 131. The hole transport functional layer 132, for example, includes at least one of a stacked hole injection layer 1321 (Hole Inject Layer, HIL), a hole transport layer 1322 (Hole Transport Layer, HTL), and an electron blocking layer 1323 (Electron Blocking Layer, EBL). When the hole transport functional layer 132 includes the hole injection layer 1321, the hole transport layer 1322, and the electron blocking layer 1323, the hole injection layer 1321, the hole transport layer 1322, and the electron blocking layer 1323 are arranged in sequence in a direction away from the anode 11, and the electron blocking layer 1323 is in contact with the light-emitting layer 131.

[0085] In some embodiments, as shown in Figures 3 to 6, to improve the luminous efficiency of the light-emitting device 100, the light-emitting unit 13 further includes an electron transport functional layer 133, which is located on the side of the light-emitting layer 131 close to the cathode 12 and in contact with the light-emitting layer 131. The electron transport functional layer 133, for example, includes at least one of a stacked electron injection layer 1331 (Electron Inject Layer, EIL), an electron transport layer 1332 (Electron Transport Layer, ETL), and a hole blocking layer 1333 (Hole Blocking Layer, EBL). When the electron transport functional layer 133 includes the electron injection layer 1331, the electron transport layer 1332, and the hole blocking layer 1333, the electron injection layer 1331, the electron transport layer 1332, and the hole blocking layer 1333 are arranged in sequence in a direction away from the cathode 12, and the hole blocking layer 1333 is in contact with the light-emitting layer 131.

[0086] By setting up the film layers such as the hole injection layer 1321, the hole transport layer 1322, the electron blocking layer 1323, the electron injection layer 1331, the electron transport layer 1332, and the hole blocking layer 1333, it is equivalent to setting up transition steps between the anode 11 and the light-emitting layer 131, and between the cathode 12 and the light-emitting layer 131, thereby reducing the potential barrier height that needs to be overcome for carrier transition, thereby making the luminescence efficiency higher.

[0087] In some examples, the hole injection layer 1321 can be configured to lower the hole injection barrier and improve the hole injection efficiency. The hole transport layer 1322 can be configured to transport holes. The electron blocking layer 1323 can be configured to transport holes and block electrons and excitons generated in the light emitting layer 131.

[0088] Exemplarily, the material of the hole injection layer 1321 can be an inorganic oxide, such as an oxide of a metal such as molybdenum, titanium, vanadium, rhenium, ruthenium, chromium, zirconium, hafnium, tantalum, silver, tungsten, or manganese; or, the material of the hole injection layer 1321 can be a dopant of a strong electron-withdrawing compound, such as F4TCNQ, HAT-CN, or the like; or, the material of the hole injection layer 1321 can be obtained by performing P-type doping on the material of the hole transport layer 1322.

[0089] For example, the thickness of the hole injection layer 1321 may be 3 nm to 30 nm.

[0090] For example, the material of the hole transport layer 1322 is a material with good hole transport properties, and may be an aromatic amine or carbazole material, such as NPB, TPD, BAFLP, DFLDPBi, and the like.

[0091] For example, the thickness of the hole transport layer 1322 may be 30 nm to 300 nm.

[0092] For example, the material of the electron blocking layer 1323 (also referred to as the light-emitting auxiliary layer) is a material having hole transport properties, which may be an aromatic amine or carbazole material, such as CBP, PCzPA, and the like.

[0093] For example, the thickness of the electron blocking layer 1323 may be 5 nm to 150 nm.

[0094] In some examples, the electron injection layer 1331 can be configured to lower the electron injection barrier and improve the electron injection efficiency. The electron transport layer 1332 can be configured to transport electrons. The hole blocking layer 1333 can be configured to transport electrons and block holes and excitons generated in the light-emitting layer 131.

[0095] Exemplarily, the material of the electron injection layer 1331 can be an alkali metal or a metal, such as lithium fluoride (LiF), ytterbium (Yb), magnesium (Mg), calcium (Ca), or the material of the electron injection layer 1331 can be a compound of ytterbium (Yb), magnesium (Mg), calcium (Ca), etc.

[0096] For example, the thickness of the electron injection layer 1331 may be 1 nm to 15 nm.

[0097] Exemplarily, the material of the hole blocking layer 1333 can be an aromatic heterocyclic compound, such as an imidazole derivative, a pyrimidine derivative, an oxazine derivative or a compound containing a nitrogen-containing six-membered ring structure, wherein the imidazole derivative is, for example, a benzimidazole derivative, an imidazopyridine derivative or a benzimidazolephenanthridine derivative, etc., the oxazine derivative is, for example, a triazine derivative, etc., and the compound containing a nitrogen-containing six-membered ring structure is, for example, a quinoline derivative, an isoquinoline derivative, a phenanthroline derivative, etc.; or, the material of the hole blocking layer 1333 can be a compound having a phosphine oxide-based substituent on the heterocyclic ring, such as OXD-7, TAZ, p-EtTAZ, BPhen, BCP.

[0098] For example, the thickness of the hole blocking layer 1333 may be 5 nm to 100 nm.

[0099] Exemplarily, the material of the electron transport layer 1332 can be an aromatic heterocyclic compound, such as an imidazole derivative, a pyrimidine derivative, an oxazine derivative or a compound containing a nitrogen-containing six-membered ring structure, wherein the imidazole derivative is, for example, a benzimidazole derivative, an imidazopyridine derivative or a benzimidazolephenanthridine derivative, etc., the oxazine derivative is, for example, a triazine derivative, etc., and the compound containing a nitrogen-containing six-membered ring structure is, for example, a quinoline derivative, an isoquinoline derivative, a phenanthroline derivative, etc.; alternatively, the material of the hole blocking layer 1333 can be a compound having a phosphine oxide-based substituent on the heterocyclic ring, such as OXD-7, TAZ, p-EtTAZ, BPhen, BCP.

[0100] For example, the thickness of the electron transport layer 1332 may be 20 nm to 120 nm.

[0101] In some embodiments, as shown in FIG3 and FIG4 , when the plurality of light-emitting devices 100 include a first light-emitting device 101, a second light-emitting device 102, and a third light-emitting device 103, the cathodes 12 of the plurality of light-emitting devices 100 may be a structure in which the entire layer is connected, that is, the cathode 12 may be a common electrode shared by the plurality of light-emitting devices 100. The hole injection layer 1321 of the plurality of light-emitting devices 100 may also be a structure in which the entire layer is connected, that is, the hole injection layer 1321 may be a common film layer shared by the plurality of light-emitting devices 100. The hole transport layer 1322, the electron blocking layer 1323, the electron injection layer 1331, the electron transport layer 1332, the hole blocking layer 1333, the electron generation layer 141, and the hole generation layer 142 may also be common film layers shared by the plurality of light-emitting devices 100, and will not be described in detail here.

[0102] For example, as shown in FIG. 3 , when the cathode 12 is a common electrode shared by a plurality of light-emitting devices 100 , the cathode 12 is simultaneously formed on a side of the pixel defining layer 221 away from the substrate 210 .

[0103] In some embodiments, as shown in Figure 4, when the multiple light-emitting devices 100 include a first light-emitting device 101, a second light-emitting device 102 and a third light-emitting device 103, the electron blocking layers 1323 of the first light-emitting device 101, the second light-emitting device 102 and the third light-emitting device 103 are independently arranged. In this way, the material of the electron blocking layer 1323 with matching performance can be selected according to the different materials of the light-emitting layer 131.

[0104] Exemplarily, in the case where the light-emitting device 100 is a single-layer light-emitting device 100, the structure of the display panel 200 including the light-emitting device 100 is, for example, as shown in Figure 5, and the light-emitting device 100 includes a stacked anode 11, a hole injection layer 1321, a hole transport layer 1322, an electron blocking layer 1323, a light-emitting layer 131, a hole blocking layer 1333, an electron transport layer 1332, an electron injection layer 1331 and a cathode 12.

[0105] Exemplarily, when the light-emitting device 100 is a single-layer light-emitting device 100, and the plurality of light-emitting devices 100 include a first light-emitting device 101, a second light-emitting device 102, and a third light-emitting device 103, the structure of the display panel 200 is, for example, as shown in FIG4, where the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 are arranged along the first direction X. Furthermore, the cathode 12 is a common electrode for the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103; the hole injection layer 1321, the hole transport layer 1322, the hole blocking layer 1333, the electron transport layer 1332, and the electron injection layer 1331 are common film layers shared by the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103; and the anode 11 is independently provided, namely, the anode 11B of the first light-emitting device 101, the anode 11G of the second light-emitting device 102, and the anode 11R of the third light-emitting device 103. The electron blocking layers 1323 are independently provided, including the electron blocking layer 1323B of the first light-emitting device 101, the electron blocking layer 1323G of the second light-emitting device 102, and the electron blocking layer 1323R of the third light-emitting device 103. The light-emitting layers 131 are independently provided, including the light-emitting layer 131B of the first light-emitting device 101, the light-emitting layer 131G of the second light-emitting device 102, and the light-emitting layer 131R of the third light-emitting device 103.

[0106] In some embodiments, the material of the light emitting layer 131 includes a host material H and a guest material D.

[0107] For example, the host material H may be configured to: transport holes or electrons, and / or to recombining electrons with holes to form excitons and transfer the exciton energy to the guest material D.

[0108] For example, the guest material D may be configured to: emit photons using the exciton energy transferred from the host material H, and / or to emit photons by forming excitons from recombined electrons and holes.

[0109] In some examples, the guest material D is a fluorescent material that can emit light using singlet excitons; in other examples, the guest material D is a phosphorescent material or a delayed fluorescent material that can emit light using triplet excitons.

[0110] In some examples, the host material H includes two or more materials. For example, the host material H may include a first host material and a second host material, wherein the first host material is a hole-type material and the second host material is an electron-type material.

[0111] For example, the thickness of the light emitting layer 131 may be 15 nm to 100 nm.

[0112] For example, the host material H of the light-emitting layer 131 of the first light-emitting device 101 may be an anthracene derivative, such as AND or MADN.

[0113] For example, the host material H of the light-emitting layer 131 of the second light-emitting device 102 can be coumarin dye, quinacridone copper derivatives, polycyclic aromatic hydrocarbons, diamine anthracene derivatives, carbazole derivatives, such as DMQA, BA-NPB, Alq3, etc.

[0114] For example, the host material H of the light-emitting layer 131 of the third light-emitting device 103 may be a DCM series material, such as DCM, DCJTB or DCJTI.

[0115] As described in the background, in the field of organic semiconductors, OLED light-emitting devices 100 have the advantages of self-luminescence, low power consumption, high resolution, large color gamut, no need for backlight, and flexibility, becoming a mainstream product and have been successfully applied in lighting systems, communication systems, vehicle display systems, portable electronic devices, and high-definition display devices 300.

[0116] With the development of OLED light-emitting devices, the requirements for their efficiency, lifespan, and other performance characteristics are becoming increasingly stringent. The efficiency and lifespan of the light-emitting device 100 are closely related to the device structure and the optimized combination of organic materials in each film layer. Specifically, the device structure of OLED light-emitting devices has evolved from the original sandwich structure to a multilayer device structure, such as a multilayer device structure including an anode 11, a hole transport layer 132, a light-emitting layer 131, an electron transport layer 133, and a cathode 12. For a description of the multilayer device structure, please refer to the previous section and will not be repeated here.

[0117] Since the mobility matching and energy level matching between the functional film layers in the light-emitting device 100, as well as the characteristics of the material itself, will affect the injection and transmission of carriers within the light-emitting device 100, and / or the formation and quenching of excitons, the interface structure of the OLED light-emitting device 100 will affect the performance of the light-emitting device 100 (such as the driving voltage, luminous efficiency and device life, etc.).

[0118] Based on this, as shown in Figures 5 and 6, some embodiments of the present disclosure provide a light-emitting device 100. The light-emitting unit 13 includes: a light-emitting layer 131 and a first-type functional layer disposed on the side of the light-emitting layer 131 near the cathode 12; the first-type functional layer 133 includes a first functional layer and a second functional layer. The material of the first functional layer includes a first functional material G1. The material of the second functional layer includes a second functional material G2. The structure of the first functional material G1 contains a fluorene group. The structure of the second functional material G2 contains a fluorene group.

[0119] The first type of functional layer is the electron transport functional layer 133. The first functional layer may be one of the electron injection layer 1331, the electron transport layer 1332, and the hole blocking layer 1333, and the second functional layer may be the other of the electron injection layer 1331, the electron transport layer 1332, and the hole blocking layer 1333.

[0120] Illustratively, the first functional layer is the electron transport layer 1332 , and the first functional material G1 is the material of the electron transport layer 1332 ; the second functional layer is the hole blocking layer 1333 , and the second functional material G2 is the material of the hole blocking layer 1333 .

[0121] It is understood that when both the first functional material G1 and the second functional material G2 contain fluorene groups in their structures, the first functional material G1 and the second functional material G2 have relatively good compatibility, which can make the transition between the first functional layer and the second functional layer smooth and improve the contact performance between the first functional layer and the second functional layer. In this way, the interface between the first functional layer and the second functional layer can be optimized, which is conducive to the transmission of electrons between the first functional layer and the second functional layer, and the electron transmission effect of the light-emitting device 100 can be improved. The electron transmission can be better controlled, so that the electrons and holes in the light-emitting layer 131 are relatively more balanced, and the recombination probability of excitons is increased. In this way, the exciton yield can be increased, thereby improving the efficiency of the light-emitting device 100. Secondly, the carrier distribution can be balanced, preventing holes or excitons from leaking to the cathode 12 side, thereby improving the life of the light-emitting device 100. In addition, when both the first functional material G1 and the second functional material G2 contain fluorene groups in their structures, the first functional material G1 and the second functional material G2 can be prepared using the same fragment, which can save preparation time and cost.

[0122] In some embodiments, the first functional layer is closer to the cathode 12 than the second functional layer. The first functional material G1 comprises an azafluorene group.

[0123] Illustratively, the first functional layer is the electron transport layer 1332 , and the first functional material G1 is the material of the electron transport layer 1332 .

[0124] It is understood that an azafluorenyl group refers to a group resulting from the replacement of at least one carbon atom in a fluorenyl group with a nitrogen atom. Because the nitrogen atom in the fluorenyl group has a certain electron-withdrawing ability, the azafluorenyl group has better electron transport properties than a fluorenyl group that does not contain nitrogen. Therefore, when the structure of the first functional material G1 includes an azafluorenyl group, the electron transport properties of the first functional material G1 can be improved, resulting in a higher electron mobility of the first functional material G1. This can improve the electron transport effect of the light-emitting device 100, increase the recombination probability of excitons, and thus improve the efficiency and lifespan of the light-emitting device 100.

[0125] Moreover, when the second functional layer is the hole blocking layer 1333, since the material of the hole blocking layer 1333 is the second functional material G2 containing a fluorene group, and the material of the electron transport layer 1332 is the first functional material G1 containing an azofluorene group, the electron transport performance of the material of the electron transport layer 1332 is relatively higher than that of the hole blocking layer 1333. In this way, the electron transport performance of the hole blocking layer 1333 and the electron transport layer 1332 can match the electron transport requirements of the electron transport functional layer 133.

[0126] It should be noted that the first functional layer may also include other materials besides the first functional material G1, and the second functional layer may also include other materials besides the second functional material G2, and the present invention is not limited thereto. In some examples, the material of the first functional layer may also include 8-hydroxyquinoline lithium (LiQ).

[0127] It should be noted that the number and position of nitrogen in the azafluorene group in the structure of the first functional material G1 are not limited here.

[0128] Illustratively, the first functional material G1 can be selected from the structure shown in the general formula (I) described in detail below, wherein, as shown in (G1-8), (G1-57), (G1-69), (G1-72), (G1-80), (G1-85), (G1-88), (G1-93), (G1-96), (G1-101), (G1-104), (G1-123), (G1-127), (G1-131), (G1-135), (G1-185), (G1-189), and (G1-193), the azafluorenyl group can be an azafluorenyl group containing one nitrogen atom.

[0129] For example, the first functional material G1 can be selected from the structure shown in the general formula (I) described in detail below, wherein, for example, (G1-1) to (G1-7), (G1-10) to (G1-31), (G1-33) to (G1-48), (G1-49) to (G1-56), (G1-58) to (G1-68), (G1-70), (G1-71), (G1-73) to (G1-75), (G1-78), (G1-79), (G1-81) to (G1-84), (G1-86), (G1-87), (G1-89) to (G1-92), (G1-94), (G1-95), (G1-97) to (G1-100), (G1-102), (G1-103), (G1-105), (G1-106) to (G1-107). 7)~(G1-122), (G1-124)~(G1-126), (G1-128)~(G1-130), (G1-132)~(G1-134), (G1 -136), (G1-137), (G1-139)~(G1-169), (G1-171)~(G1-173), (G1-175)~(G1-177), ( As shown in Figures 1-179 to 1-181, (G1-183), (G1-184), (G1-187), (G1-188), (G1-191), (G1-192), (G1-195), (G1-196), (G1-199), (G1-203), and (G1-204), the azafluorenyl group may be an azafluorenyl group containing two nitrogen atoms. Furthermore, the relative positions of the two nitrogen atoms are not limited here.

[0130] For example, the first functional material G1 can be selected from the structure represented by the general formula (I) described in detail below, wherein, as shown in (G1-9), the azafluorenyl group can be an azafluorenyl group containing three nitrogen atoms. Moreover, the relative positions of the three nitrogen atoms are not limited herein.

[0131] For example, the first functional material G1 can be selected from the structure represented by the general formula (I) described in detail below, wherein the azafluorenyl group can be an azafluorenyl group containing four nitrogen atoms, as represented by (G1-32), (G1-76), (G1-77), (G1-106), (G1-138), (G1-170), (G1-174), (G1-178), (G1-182), (G1-186), (G1-190), and (G1-194). Furthermore, the relative positions of the four nitrogen atoms are not limited herein.

[0132] In some embodiments, the first functional material G1 is selected from any one of the structures represented by the following general formula (I).

[0133] Among them, X 11 、X 12 、X 13 、X 14 、X 15 、X 16 、X 17 and X 18 are independently selected from C(R a ) and N; X 11 、X 12 、X 13 、X 14 、X 15 、X 16 、X 17 and X 18 Any two of them, the same or different; and X 11 、X 12 、X 13 and X 14 Among them, at least one is N. Among them, C(R a ) is R a substituted carbon, N is nitrogen.

[0134] R 11 、R 12 、R 13 、R 14 and R a the same or different, and independently selected from any one of hydrogen, deuterium, halogen, cyano, nitro, hydroxyl, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 5- to 30-membered heteroaryl and substituted or unsubstituted 3- to 30-membered heterocyclyl; or may be connected with adjacent groups to form a substituted or unsubstituted 3- to 30-membered ring.

[0135] L 11 Any one selected from a direct bond, a substituted or unsubstituted C3-C30 alkylene group, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted 5- to 30-membered heteroarylene group.

[0136] A is selected from any one of a substituted or unsubstituted C6-C12 aryl group and a substituted or unsubstituted 5- to 12-membered heteroaryl group.

[0137] n 11 Select any one from 0, 1 and 2.

[0138] n 12 Select either 0 or 1.

[0139] Regarding the structure shown in general formula (I), the following points need to be explained:

[0140] In the structure shown in general formula (I), X 11 、X 12 、X 13 and X 14 At least one of them is N, that is, the fluorenyl group contained in the structure represented by general formula (I) is an azafluorenyl group.

[0141] L 11 Can be a direct key, and, when L 11 When the azafluorenyl group and the IA part (ie, the A ring and the X 15 、X 16 、X 17 and X 18 The six-membered ring of the fused ring and the resulting fused ring group) are directly connected by a covalent bond.

[0142] L 11 It can be selected from any one of a substituted or unsubstituted C3-C30 alkylene group, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted 5- to 30-membered heteroarylene group. Among them, the Cx alkylene group refers to an alkylene group having a total of x carbon (C) atoms, x is a positive integer, and the same applies to the following. For the understanding of other groups such as Cx arylene groups and Cx heteroarylene groups, please refer to the above content and will not be repeated here. In addition, phenyl refers to the general term for the group remaining after the hydrogen atom of one carbon atom on the benzene ring is removed. Phenylene refers to the general term for the group remaining after the hydrogen atoms on two carbon atoms on the benzene ring are removed. For the understanding of other groups such as arylene groups, heteroarylene groups, alkylene groups, etc., please refer to the above content and will not be repeated here. In addition, a Z-membered heteroarylene group refers to a heteroarylene group with Z as the number of atoms on the ring, Z is a positive integer, and the same applies to the following. For the understanding of other groups such as Z-membered heteroaryl and Cx-membered heterocyclic groups, please refer to the above content and will not be repeated here. Here, the ring atoms refer to the atoms connected by chemical bonds to form a ring, for example, the ring atoms of a benzene ring are six carbon atoms.

[0143] In the structure shown in general formula (I), L 11 Connected to the B ring of the azafluorenyl group, and L 11 Also connected to the IA part. 11 The connection position with the B ring in the azafluorenyl group refers to L 11 It can be connected to any atom on the ring B that has a substitution position. 11 The connection position with IA part refers to L 11 It can be connected to any ring atom with a substitution position in the IA part. 11The connection position with the azafluorenyl group, and L 11 The connection position with the IA part is not limited here.

[0144] In the structure shown in general formula (I), (R x ) ny , refers to the substituent R x The number of R is ny. When ny is 0, it means that the carbon atoms with substitution positions on the corresponding six-membered ring are all replaced by hydrogen atoms. When ny is a positive integer greater than or equal to 1, it means that there are ny R atoms connected to the corresponding six-membered ring. x ; Moreover, ny R x It can be connected to any ny of the six carbon atoms on the six-membered ring; x The position of the carbon atom connected is not limited here. When ny is a positive integer greater than 1, ny R x They may be the same or different. Wherein, x is any one of 13 and 14, and y is any one of 11 and 12.

[0145] When R 11 、R 12 、R 13 、R 14 and R a any one selected from substituted C1-C30 alkyl, substituted C2-C30 alkenyl, substituted C2-C30 alkynyl, substituted C3-C30 cycloalkyl, substituted C1-C30 alkoxy, substituted C6-C30 aryl, substituted 5- to 30-membered heteroaryl, and substituted 3- to 30-membered heterocyclic group, and / or L 11 When A is selected from any one of a substituted C3-C30 alkylene group, a substituted C6-C30 arylene group, and a substituted 5- to 30-membered heteroarylene group, and / or A is selected from any one of a substituted C6-C12 aryl group and a substituted 5- to 12-membered heteroaryl group, the type and number of the substituents are not limited herein.

[0146] It can be understood that, on the one hand, the structure shown in the general formula (I) contains at least one electron-withdrawing group with good planarity (for example, the IA part), which can produce a conjugation effect, so that the first functional material G1 has a wider LUMO electron cloud distribution. In this way, the lowest unoccupied molecular orbital (LUMO) energy level of the first functional material G1 can be relatively low, so that the electron mobility of the first functional material G1 is relatively high; on the other hand, the structure shown in the general formula (I) contains an azafluorene group, which has a certain electron-withdrawing ability. Compared with the fluorene group that does not contain nitrogen, the azafluorene group has better electron transport performance, so that the electron mobility of the first functional material G1 is higher; in this way, the electron transport performance of the first functional material G1 can be improved, the recombination probability of excitons can be increased, and the efficiency and life of the light-emitting device 100 can be improved.

[0147] In some examples, the LUMO electron cloud distribution diagram, HOMO electron cloud distribution diagram, T1 hole electron cloud distribution diagram, and T1 electron electron cloud distribution diagram of the first functional material G1 (for example, the first functional material G1 with the structural formula (G1-97) described in detail below) are shown in Figures 8, 9, 10, and 11. As shown in Figure 8, the LUMO electron cloud of the first functional material G1 is distributed at the location of the electron-withdrawing group with good planarity. Moreover, because the first functional material G1 can produce a conjugated effect, the first functional material G1 has a wider LUMO electron cloud distribution, for example, the LUMO electron cloud can also be located at the location of the fluorene group.

[0148] The IA portion can be conjugated with the nitrogen-containing fluorene group so that at least part of the LUMO electron cloud can be distributed in the area where the nitrogen-containing fluorene group is located. In this way, the first functional material G1 can have a relatively wide LUMO electron cloud distribution, the LUMO energy level of the first functional material G1 can be lowered, and the electron mobility of the first functional material G1 can be improved.

[0149] An exemplary structure of the first functional material G1 having the structure represented by general formula (I) is described below.

[0150] In some examples, when R 11 、R 12 When it is a methyl group, the structural formula of the first functional material G1 can be shown as follows.

[0151] In some examples, when R 11 、R 12 When connected to form a six-membered ring, the structural formula of the first functional material G1 can be shown as follows.

[0152] It is understandable that when R 11 、R 12 When connected to form a six-membered ring, the six-membered ring and the azafluorene group share an sp3 carbon atom to form a spirocyclic group. Since the spirocyclic group has an orthogonal stereo configuration, the stereo nature of the configuration of the first functional material G1 can be improved, and the first functional material G1 can be prevented from crystallizing. At the same time, the first functional material G1 can have a higher glass transition temperature. In this way, firstly, the film-forming property of the first functional material G1 can be improved; secondly, the thermal stability of the first functional material G1 can be improved, thereby increasing the life of the light-emitting device 100.

[0153] It should be noted that the above-listed structural formulas are examples of the structure of the first functional material G1 and are not intended to limit the first functional material G1. Furthermore, (G1-x) in the above structural formulas is a synonym for each structural formula and is not part of the structural formula structure, where x is a positive integer.

[0154] In some embodiments, the first functional material G1 is selected from any one of the structures represented by the following general formula (IA).

[0155] Among them, X 31 、X 32 、X 33 、X 34 、X 35 、X 36 、X 37 and X 38 are independently selected from C(R c ) and N; X 31 、X 32 、X 33 、X 34 、X 35 、X 36 、X 37 and X 38 Any two of them may be the same or different. c ) is R c substituted carbon, N is nitrogen.

[0156] Y 31 Selected from direct bond, C(R d R e ), any one of O, S and Se. Among them, C(R d R e ) is R d and R e Substituted carbon, O is oxygen, S is sulfur, and Se is selenium.

[0157] R c 、Rd and R e the same or different, and independently selected from any one of hydrogen, deuterium, halogen, cyano, nitro, hydroxyl, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 5- to 30-membered heteroaryl and substituted or unsubstituted 3- to 30-membered heterocyclyl; or may be connected with adjacent groups to form a substituted or unsubstituted 3- to 30-membered ring.

[0158] It should be noted that Y 31 Can be a direct key, and, when Y 31 In the case of a direct bond, carbon 1 and carbon 2 of the IB portion are directly connected by a covalent bond.

[0159] It should be noted that when R c 、R d and R e When the substituent is selected from any one of a substituted C1-C30 alkyl group, a substituted C2-C30 alkenyl group, a substituted C2-C30 alkynyl group, a substituted C3-C30 cycloalkyl group, a substituted C1-C30 alkoxy group, a substituted C6-C30 aryl group, a substituted 5- to 30-membered heteroaryl group, and a substituted 3- to 30-membered heterocyclyl group, the type and number of the substituent are not limited herein.

[0160] The description of Cx alkyl, Cx alkenyl, etc. herein can be found in the description of Cx alkylene above; the description of Z-membered heteroaryl, Z-membered heterocyclic group, and Z-membered ring herein can be found in the description of Z-membered heteroarylene above; and will not be repeated here. Symbols in Formula (IA) other than those mentioned above have the same meanings as in Formula (I).

[0161] It is understood that, when the structure shown in the general formula (I) is 11 and R 12 When connected to form the structure shown in the IB portion, the structure shown in the general formula (I) can be transformed into the structure shown in the general formula (IA).

[0162] When the first functional material G1 is selected from any one of the structures shown in the general formula (IA), the IB part and the azafluorene group share the sp3 carbon atom to form a spirocyclic group. Since the spirocyclic group has an orthogonal stereoconfiguration, the stereoscopic properties of the configuration of the first functional material G1 can be improved, and the first functional material G1 can be prevented from crystallizing. At the same time, the first functional material G1 can have a higher glass transition temperature. In this way, firstly, the film-forming property of the first functional material G1 can be improved; secondly, the thermal stability of the first functional material G1 can be improved, thereby increasing the life of the light-emitting device 100.

[0163] An exemplary structure of the first functional material G1 having a structure represented by general formula (IA) is described below.

[0164] In some examples, when Y 31 When it is a direct bond, the structural formula of the first functional material G1 can be shown as follows.

[0165] In some examples, when Y 31 When it is substituted carbon, the structural formula of the first functional material G1 can be shown as follows.

[0166] In some examples, when Y 31 When oxygen is used, the structural formula of the first functional material G1 may be as shown below.

[0167] In some examples, when Y 31 When sulfur is used, the structural formula of the first functional material G1 can be shown as follows.

[0168] It should be noted that the above-listed structural formulas are examples of the structure of the first functional material G1 and are not intended to limit the first functional material G1. Furthermore, (G1-x) in the above structural formulas is a synonym for each structural formula and is not part of the structural formula structure, where x is a positive integer.

[0169] In some embodiments, R 11 is phenyl; R 12 It is phenyl.

[0170] It is understood that, when the structure shown in the general formula (I) is 11 and R 12 When both are phenyl, R 11 、R 12Shares sp3 carbon atom with azafluorenyl, R 11 Between the plane where the benzene ring is located and the plane where the azafluorenyl group is located, and R 12 There is a certain angle between the plane where the benzene ring is located and the plane where the nitrogen-fluorene group is located, which can improve the three-dimensionality of the configuration of the first functional material G1, prevent the first functional material G1 from crystallizing, and at the same time make the first functional material G1 have a higher glass transition temperature. In this way, firstly, the film-forming property of the first functional material G1 can be improved; secondly, the thermal stability of the first functional material G1 can be improved, so that the life of the light-emitting device 100 is increased.

[0171] The following describes when R 11 and R 12 When all are phenyl groups, the exemplary structure of the first functional material G1 is as shown in the general formula (I).

[0172] It should be noted that the above-listed structural formulas are examples of the structure of the first functional material G1 and are not intended to limit the first functional material G1. Furthermore, (G1-x) in the above structural formulas is a synonym for each structural formula and is not part of the structural formula structure, where x is a positive integer.

[0173] In some embodiments, A is selected from any one of the structures represented by the following formula (A1-1), formula (A1-2), formula (A1-3) and formula (A1-4).

[0174] Among them, # represents a fusion site.

[0175] R g and R h The same or different groups are independently selected from any one of hydrogen, deuterium, halogen, cyano, nitro, hydroxyl, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 5- to 30-membered heteroaryl and substituted or unsubstituted 3- to 30-membered heterocyclyl; or they may be connected with adjacent groups to form a substituted or unsubstituted 3- to 30-membered ring.

[0176] It should be noted that # represents the fusion site, which refers to the A ring and the X 15 、X 16 、X 17 and X 18 The six-membered ring of IA is formed by sharing atoms at the fusion site.

[0177] It should be noted that when R g or R h When the substituent is selected from any one of a substituted C1-C30 alkyl group, a substituted C2-C30 alkenyl group, a substituted C2-C30 alkynyl group, a substituted C3-C30 cycloalkyl group, a substituted C1-C30 alkoxy group, a substituted C6-C30 aryl group, a substituted 5- to 30-membered heteroaryl group, and a substituted 3- to 30-membered heterocyclyl group, the type and number of the substituent are not limited herein.

[0178] The description of the alkyl group of Cx, the alkenyl group of Cx, etc. here can refer to the above description of the alkylene group of Cx; the description of the Z-membered heteroaryl group, the Z-membered heterocyclic group, and the Z-membered ring here can refer to the above description of the Z-membered heteroarylene group; they will not be repeated here.

[0179] It should be noted that when A is selected from any one of the structures represented by general formula (A1-1), general formula (A1-2), general formula (A1-3) and general formula (A1-4), and in the structure represented by general formula (I), L 11 Connected to the R in the A ring g When connected to carbon, R g It may not exist.

[0180] It should be noted that when A is selected from any one of the structures represented by general formula (A1-1), general formula (A1-2), general formula (A1-3) and general formula (A1-4), with respect to R 11 and R 12 There is no restriction on the type of choice. 11 and R 12 It may be independently selected from any one of hydrogen, deuterium, halogen, cyano, nitro, hydroxyl, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 5- to 30-membered heteroaryl, and substituted or unsubstituted 3- to 30-membered heterocyclyl; or it may be connected with adjacent groups to form a substituted or unsubstituted 3- to 30-membered ring. In particular, R 11 、R 12 Can be connected to form a six-membered ring, or, R 11 、R 12 Can be connected to form the structure shown in part IB, or, R 11 、R 12 They may all be phenyl.

[0181] It is understood that when A in the general formula (I) is selected from When Y is one of the structures shown in the following formulas, A can be a structure shown in the following formulas (A1-1), (A1-2), (A1-3), (A1-4). 61 -N(R h )-,Y 62 =–N, X 61 -C(R g )=, A is the structure shown in the general formula (A1-1), in which case A is an imidazole ring. 61 is –Se–, Y 62 =–N, X 61 -C(R g )=, A is the structure shown in the general formula (A1-2), in which case A is a selenium nitrogen heterocycle. 61 For –O–, Y 62 =–N, X 61 -C(R g )=, A is a structure represented by the general formula (A1-3), in which case A is an oxazole ring. 61 For –S–, Y 62 =–N, X 61 -C(R g )=, A is a structure represented by the general formula (A1-4), in which case A is a thiazole ring.

[0182] When A is selected from any of the structures represented by General Formula (A1-1), General Formula (A1-2), General Formula (A1-3), and General Formula (A1-4), A can be one of an imidazole ring, a selenium nitrogen heterocycle, an oxazole ring, and a thiazole ring. On the one hand, because imidazole rings, selenium nitrogen heterocycles, oxazole rings, and thiazole rings all have certain electron-withdrawing capabilities, they can improve the electron transport performance of the first functional material G1, increase the electron mobility of the first functional material G1, increase the recombination probability of excitons, and thus improve the efficiency and lifespan of the light-emitting device 100. On the other hand, when the molecular weight of A is low, the molecular weight of the first functional material G1 is relatively low, so that the stability of the first functional material G1 is relatively low; when the molecular weight of A is high, the molecular weight of the first functional material G1 is relatively high, which may increase the difficulty of synthesizing the first functional material G1, and the matching with the preparation process of the first functional layer (such as the evaporation process) is relatively poor; therefore, by setting A to be one of the imidazole ring, oxazole ring and thiazole ring, the molecular weight of A can be within an appropriate range, ensuring the stability of the first functional material G1 while reducing the difficulty of synthesizing the first functional material G1, and at the same time improving the matching between the first functional material G1 and the preparation process of the first functional layer (such as the evaporation process).

[0183] The following describes an exemplary structure of the first functional material G1 when A is selected from any one of the structures represented by General Formula (A1-1), General Formula (A1-2), General Formula (A1-3) and General Formula (A1-4).

[0184] In some examples, when A is selected from the structure shown in general formula (A1-3), the structural formula of the first functional material G1 can be as shown above (G1-49) to (G1-104), (G1-200), and (G1-204).

[0185] In some examples, when A is selected from the structure shown in general formula (A1-4), the structural formula of the first functional material G1 can be as shown above (G1-201).

[0186] It should be noted that the structural formula listed above is an example of the structure of the first functional material G1, and does not limit the first functional material G1.

[0187] In some embodiments, A is selected from any one of the structures represented by the following formula (A2), formula (A3), formula (A4) and formula (A5).

[0188] Among them, # represents a fusion site.

[0189] X 41 、X 42 、X 43 、X 44 、X 45 、X 46 、X 51 、X 52 、X 53 、X 54 、X 55 、X 56 、X 71 、X 72 、X 73 、X 74 、X 81 、X 82 、X 83 and X 84 are independently selected from C(R f ) and N; X 41 、X 42 、X 43 、X 44 、X 45 、X 46 、X 51 、X 52 、X 53 、X 54 、X 55 、X 56 、X71 、X 72 、X 73 、X 74 、X 81 、X 82 、X 83 and X 84 Any two of them may be the same or different. f ) is R f substituted carbon, N is nitrogen.

[0190] Y 81 Selected from C(R i R j )、N(R k ), any one of O, S and Se. Among them, C(R i R j ) is R i and R j Substituted carbon, N(R k ) is R k substituted nitrogen, O is oxygen, S is sulfur, and Se is selenium.

[0191] R f 、R i 、R j and R k The same or different groups are independently selected from any one of hydrogen, deuterium, halogen, cyano, nitro, hydroxyl, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 5- to 30-membered heteroaryl and substituted or unsubstituted 3- to 30-membered heterocyclyl; or they may be connected with adjacent groups to form a substituted or unsubstituted 3- to 30-membered ring.

[0192] It should be noted that when R f 、R i 、R j or R k When the substituent is selected from any one of a substituted C1-C30 alkyl group, a substituted C2-C30 alkenyl group, a substituted C2-C30 alkynyl group, a substituted C3-C30 cycloalkyl group, a substituted C1-C30 alkoxy group, a substituted C6-C30 aryl group, a substituted 5- to 30-membered heteroaryl group, and a substituted 3- to 30-membered heterocyclyl group, the type and number of the substituent are not limited herein.

[0193] The description of the alkyl group of Cx, the alkenyl group of Cx, etc. here can refer to the above description of the alkylene group of Cx; the description of the Z-membered heteroaryl group, the Z-membered heterocyclic group, and the Z-membered ring here can refer to the above description of the Z-membered heteroarylene group; the description of the fusion site here can refer to the above description of the fusion site; it will not be repeated here.

[0194] It should be noted that when A is selected from any one of the structures shown in general formula (A2), general formula (A3), general formula (A4) and general formula (A5), and L in the structure shown in general formula (I) 11 Connected to the R in the A ring f When the atoms on the ring are connected, R f It may not exist. For other 11 Connected to the R in the A ring i 、R j and R k The understanding of the atoms on the connected ring, etc. can refer to the above content and will not be repeated here.

[0195] It should be noted that when A is selected from any one of the structures shown in general formula (A2), general formula (A3), general formula (A4) and general formula (A5), with respect to R 11 and R 12 There is no restriction on the type of choice. 11 and R 12 It may be independently selected from any one of hydrogen, deuterium, halogen, cyano, nitro, hydroxyl, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 5- to 30-membered heteroaryl, and substituted or unsubstituted 3- to 30-membered heterocyclyl; or it may be connected with adjacent groups to form a substituted or unsubstituted 3- to 30-membered ring. In particular, R 11 、R 12 Can be connected to form a six-membered ring, or, R 11 、R 12 Can be connected to form the structure shown in part IB, or, R 11 、R 12 They may all be phenyl.

[0196] It is understood that when the molecular weight of A is low, the molecular weight of the first functional material G1 is relatively low, resulting in relatively low stability of the first functional material G1. When the molecular weight of A is high, the molecular weight of the first functional material G1 is relatively high, which may increase the difficulty of synthesizing the first functional material G1 and reduce its compatibility with the preparation process of the first functional layer (e.g., a vapor deposition process). When A is selected from any of the structures represented by general formula (A2), general formula (A3), general formula (A4), and general formula (A5), the molecular weight of A can be within an appropriate range, ensuring the stability of the first functional material G1 while reducing the difficulty of synthesizing the first functional material G1 and improving its compatibility with the preparation process of the first functional layer (e.g., a vapor deposition process).

[0197] The following describes an exemplary structure of the first functional material G1 when A is selected from any one of the structures represented by general formula (A2), general formula (A3), general formula (A4) and general formula (A5).

[0198] In some examples, when A is selected from the structure shown in general formula (A2), the structural formula of the first functional material G1 can be as shown above (G1-1) to (G1-48), (G1-198), (G1-199), (G1-202), and (G1-203).

[0199] In some examples, when A is selected from the structure shown in general formula (A3), the structural formula of the first functional material G1 can be as shown in (G1-105) to (G1-136) above.

[0200] In some examples, when A is selected from the structure shown in general formula (A4), the structural formula of the first functional material G1 can be as shown above (G1-23), (G1-73), (G1-137) to (G1-168).

[0201] In some examples, when A is selected from the structure shown in general formula (A5), the structural formula of the first functional material G1 can be as shown in (G1-76), (G1-169) to (G1-197) above.

[0202] It should be noted that the structural formula listed above is an example of the structure of the first functional material G1, and does not limit the first functional material G1.

[0203] In some embodiments, A is selected from any one of the structures shown in general formula (A2). 15 、X 16 、X 17 and X 18 The six-membered ring forms a phenanthroline group.

[0204] It should be noted that A is selected from any one of the structures shown in general formula (A2), and A and X 15 、X 16 、X 17 and X 18 The six-membered ring forms a phenanthroline group, which means that in the structure shown in the general formula (I), the IA part is a phenanthroline group.

[0205] When the IA portion is a phenanthroline group, on the one hand, since the phenanthroline group has a certain electron-withdrawing ability, the electron transport performance of the first functional material G1 can be improved, the electron mobility of the first functional material G1 is higher, the recombination probability of the excitons is increased, and the efficiency and life of the light-emitting device 100 are improved. On the other hand, by setting the IA portion as a phenanthroline group, the molecular weight of the first functional material G1 can be within an appropriate range, ensuring the stability of the first functional material G1 while reducing the difficulty of synthesizing the first functional material G1. At the same time, the compatibility of the first functional material G1 with the preparation process of the first functional layer (for example, a vapor deposition process) can be improved.

[0206] The following describes when A is selected from any one of the structures shown in general formula (A2), and A and containing X 15 、X 16 、X 17 and X 18 When the six-membered ring of IA forms a phenanthroline group (i.e., the IA portion is a phenanthroline group), the exemplary structure of the first functional material G1 is as shown in (G1-1) to (G1-48), (G1-198), (G1-202), and (G1-203).

[0207] It should be noted that the structural formula listed above is an example of the structure of the first functional material G1, and does not limit the first functional material G1.

[0208] In some embodiments, A is selected from any one of the structures shown in general formula (A4). 15 、X 16 、X 17 and X 18 The six-membered ring forms a benzodiazinyl group.

[0209] It should be noted that A is selected from any one of the structures shown in the general formula (A4), and A and X 15 、X 16 、X 17 and X 18 The six-membered ring forms a benzodiazine group, which means that in the structure shown in the general formula (I), the IA part is a benzodiazine group.

[0210] When the IA moiety is a benzodiazine group, on the one hand, due to the benzodiazine group's electron-withdrawing ability, the electron transport properties of the first functional material G1 can be improved, resulting in a higher electron mobility of the first functional material G1, increasing the recombination probability of excitons, and improving the efficiency and lifespan of the light-emitting device 100. On the other hand, by configuring the IA moiety as a benzodiazine group, the molecular weight of the first functional material G1 can be adjusted to a suitable range, ensuring the stability of the first functional material G1 while reducing the difficulty of synthesizing the first functional material G1 and improving the compatibility of the first functional material G1 with the preparation process (e.g., a vapor deposition process) of the first functional layer.

[0211] The following describes when A is selected from any one of the structures shown in general formula (A4), and A and containing X 15 、X 16 、X 17 and X 18 When the six-membered ring of IA forms a benzodiazine group (i.e., the IA portion is a benzodiazine group), the exemplary structure of the first functional material G1 is shown in (G1-137), (G1-139), (G1-141) to (G1-168) above.

[0212] It should be noted that the structural formula listed above is an example of the structure of the first functional material G1, and does not limit the first functional material G1.

[0213] In some embodiments, the second functional material G2 is selected from any one of the structures represented by the following general formula (II).

[0214] Among them, X 21 、X 22 、X 23 and X 24 are independently selected from C(R b ) and N; X 21 、X 22 、X 23 and X 24 Any two of them may be the same or different. b ) is R b substituted carbon, N is nitrogen.

[0215] R 21 、R 22 、R 23 、R 24 and R bthe same or different, and independently selected from any one of hydrogen, deuterium, halogen, cyano, nitro, hydroxyl, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 5- to 30-membered heteroaryl and substituted or unsubstituted 3- to 30-membered heterocyclyl; or may be connected with adjacent groups to form a substituted or unsubstituted 3- to 30-membered ring.

[0216] L 21 Any one selected from a direct bond, a substituted or unsubstituted C3-C30 alkylene group, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted 5- to 30-membered heteroarylene group.

[0217] Ar1 and Ar2 are the same or different and are independently selected from any one of substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 5- to 30-membered heteroaryl and substituted or unsubstituted 3- to 30-membered heterocyclyl; or they may be connected with adjacent groups to form a substituted or unsubstituted 3- to 30-membered ring.

[0218] n 21 Select any one from 0, 1 and 2.

[0219] n 22 Select either 0 or 1.

[0220] Regarding the structure shown in general formula (II), the following points need to be explained:

[0221] L 21 Can be a direct key, and, when L 21 In the case of a direct bond, the triazine group and the phenylene group are directly connected via a covalent bond.

[0222] In the structure represented by general formula (II), the phenylene group is connected to the E ring of the fluorenyl group. Regarding the connection position of the phenylene group to the E ring of the fluorenyl group, it means that the phenylene group can be connected to any atom on the E ring of the fluorenyl group that has a substituted position. The connection position of the phenylene group to the E ring of the fluorenyl group is not limited.

[0223] The description of the alkylene group and the arylene group of Cx can refer to the above description of the alkylene group of Cx; the description of the Z-membered heteroarylene group can refer to the above description of the Z-membered heteroarylene group;23 ) n21 and (R 24 ) n22 The description of (R x ) ny The description of the atoms on the ring can refer to the above description of the atoms on the ring; it will not be repeated here.

[0224] When R 21 、R 22 、R 23 、R 24 or R b any one selected from substituted C1-C30 alkyl, substituted C2-C30 alkenyl, substituted C2-C30 alkynyl, substituted C3-C30 cycloalkyl, substituted C1-C30 alkoxy, substituted C6-C30 aryl, substituted 5- to 30-membered heteroaryl, and substituted 3- to 30-membered heterocyclyl; and / or, L 21 When Ar1 or Ar2 is selected from any one of substituted C3-C30 alkylene, substituted C6-C30 arylene and substituted 5- to 30-membered heteroarylene; and / or, when Ar1 or Ar2 is selected from any one of substituted C1-C30 alkyl, substituted C2-C30 alkenyl, substituted C2-C30 alkynyl, substituted C3-C30 cycloalkyl, substituted C1-C30 alkoxy, substituted C6-C30 aryl, substituted 5- to 30-membered heteroaryl and substituted 3- to 30-membered heterocyclyl, the type and number of the substituents are not limited herein.

[0225] It can be understood that the structure shown in general formula (II) contains a triazine group, and the triazine group has a lower LUMO energy level and a stronger electron-withdrawing ability, so that the LUMO electron cloud of the second functional material G2 is mainly distributed at the position of the triazine group. At the same time, compared with other groups in the structure shown in general formula (II), the fluorenyl group has a relatively strong electron-donating ability, so that the HOMO electron cloud and the T1 energy level electron cloud of the second functional material G2 are distributed at the position of the fluorenyl group, making the fluorenyl group the most influential group in the highest occupied molecular orbital (HOM). The main factor affecting the optical density of the second functional material G2 is the HOMO (Homo Orbital Molecular Weight) energy level and the triplet energy level (T1 energy level). Moreover, the structure shown in general formula (II) includes a phenylene group with two connection sites, and the two connection sites are distributed in the meta position. In this way, the phenylene group can be used to separate the fluorenyl group and the triazine group, thereby reducing the delocalization of the HOMO electron cloud and the T1 energy level electron cloud distributed on the electron-donating group fluorenyl group to the electron-withdrawing group triazine group. As a result, the HOMO energy level of the second functional material G2 is deeper and the T1 energy level is higher. In this way, the leakage of holes and excitons in the light-emitting layer 131 to the cathode 12 side can be blocked, thereby increasing the recombination probability of excitons and improving the efficiency and life of the light-emitting device 100.

[0226] In some examples, the LUMO electron cloud distribution of the second functional material G2 is shown in Figure 12; the HOMO electron cloud distribution of the second functional material G2 is shown in Figure 13; the electron cloud distribution of the T1 hole of the second functional material G2 is shown in Figure 14; and the electron cloud distribution of the T1 electron of the second functional material G2 is shown in Figure 15. As shown in Figures 12-15, the LUMO electron cloud of the second functional material G2 is distributed at the position of the triazine group; the HOMO electron cloud of the second functional material G2 is primarily distributed at the position of the fluorenyl group; the electron cloud of the T1 hole of the second functional material G2 is primarily distributed at the position of the fluorenyl group; and the electron cloud of the T1 electron of the second functional material G2 is primarily distributed at the position of the fluorenyl group. Furthermore, due to the separating effect of the phenylene group, the delocalization of the HOMO electron cloud, the electron cloud of the T1 hole, and the electron cloud of the T1 electron of the second functional material G2 toward the position of the triazine group is reduced compared to the first functional material G1.

[0227] An exemplary structure of the second functional material G2 having the structure represented by general formula (II) is described below.

[0228] In some embodiments, R 21 is methyl; R 22 It is a methyl group.

[0229] It is understood that, when in the structure shown in the general formula (II), R 21 and R 22When all of them are methyl groups, the stability of the second functional material G2 can be made relatively high on the basis of making the HOMO energy level of the second functional material G2 deeper and the T1 energy level higher, thereby increasing the life of the light-emitting device 100.

[0230] The following describes when R 21 and R 22 When all are methyl groups, the exemplary structure of the second functional material G2 is as shown in the general formula (II).

[0231] In some embodiments, R 21 is phenyl; R 22 It is phenyl.

[0232] It is understood that, when in the structure shown in the general formula (II), R 21 and R 22 When both are phenyl, R 21 、R 22 Shares sp3 carbon atom with fluorenyl, R 21 There is a certain angle between the plane where the benzene ring is located and the plane where the fluorene group is located, and R 22 There is a certain angle between the plane where the benzene ring is located and the plane where the fluorene group is located, which can improve the three-dimensionality of the configuration of the second functional material G2, prevent the second functional material G2 from crystallizing, and at the same time make the second functional material G2 have a higher glass transition temperature. In this way, firstly, the film-forming property of the second functional material G2 can be improved; secondly, the thermal stability of the second functional material G2 can be improved, so that the life of the light-emitting device 100 is increased.

[0233] The following describes when R 21 and R 22 When all are phenyl groups, the exemplary structure of the second functional material G2 is as shown in the general formula (II).

[0234] In some examples, when R 21 and R 22 When one is a phenyl group and the other is a naphthyl group, the structural formula of the second functional material G2 can be shown as follows.

[0235] It is understandable that when R 21 and R 22 When one is phenyl and the other is naphthyl, R 21 and R 22 The same is true for the case where both are phenyl groups. 21 、R 22Sharing the sp3 carbon atom with the fluorene group can improve the stereoscopic properties of the configuration of the second functional material G2, prevent the second functional material G2 from crystallizing, and at the same time make the second functional material G2 have a higher glass transition temperature. In this way, firstly, the film-forming property of the second functional material G2 can be improved; secondly, the thermal stability of the second functional material G2 can be improved, thereby increasing the life of the light-emitting device 100.

[0236] In some examples, when R 21 、R 22 When connected to form a six-membered ring, the structural formula of the second functional material G2 can be shown as follows.

[0237] It is understandable that when R 21 、R 22 When connected to form a six-membered ring, the six-membered ring and the fluorenyl group share an sp3 carbon atom to form a spirocyclic group. Since the spirocyclic group has an orthogonal stereo configuration, the stereoscopic properties of the configuration of the second functional material G2 can be improved, and the second functional material G2 can be prevented from crystallizing. At the same time, the second functional material G2 can have a higher glass transition temperature. In this way, firstly, the film-forming property of the second functional material G2 can be improved; secondly, the thermal stability of the second functional material G2 can be improved, thereby increasing the life of the light-emitting device 100.

[0238] It should be noted that the above-listed structural formulas are examples of the structure of the second functional material G2 and are not intended to limit the second functional material G2. Furthermore, (G2-x) in the above structural formulas is a synonym for each structural formula and is not part of the structural formula structure, where x is a positive integer.

[0239] In some embodiments, the second functional material G2 is selected from any one of the structures represented by the following general formula (II-A).

[0240] Among them, X 91 、X 92 、X 93 、X 94 、X 95 、X 96 、X 97 and X 98 are independently selected from C(R n ) and N; X 91 、X 92 、X 93 、X 94 、X 95 、X 96 、X 97 and X 98Any two of them may be the same or different. n ) is R n substituted carbon, N is nitrogen.

[0241] Y 91 Selected from direct bond, C(R o R p ), any one of O, S and Se. Among them, C(R o R p ) is R o and R p Substituted carbon, O is oxygen, S is sulfur, and Se is selenium.

[0242] R n 、R o and R p the same or different, and independently selected from any one of hydrogen, deuterium, halogen, cyano, nitro, hydroxyl, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 5- to 30-membered heteroaryl and substituted or unsubstituted 3- to 30-membered heterocyclyl; or may be connected with adjacent groups to form a substituted or unsubstituted 3- to 30-membered ring.

[0243] It should be noted that Y 91 Can be a direct key, and, when Y 91 In the case of a direct bond, carbon 3 and carbon 4 of the IIB portion are directly connected by a covalent bond.

[0244] It should be noted that when R n 、R o and R p When the substituent is selected from any one of a substituted C1-C30 alkyl group, a substituted C2-C30 alkenyl group, a substituted C2-C30 alkynyl group, a substituted C3-C30 cycloalkyl group, a substituted C1-C30 alkoxy group, a substituted C6-C30 aryl group, a substituted 5- to 30-membered heteroaryl group, and a substituted 3- to 30-membered heterocyclyl group, the type and number of the substituent are not limited herein.

[0245] The description of Cx alkyl, Cx alkenyl, etc. herein can be found in the description of Cx alkylene above; the description of Z-membered heteroaryl, Z-membered heterocyclic group, and Z-membered ring herein can be found in the description of Z-membered heteroarylene above; and will not be repeated here. Symbols in Formula (II-A) other than those mentioned above have the same meanings as in Formula (II).

[0246] It is understood that, when in the structure shown in the general formula (II), R 21 and R 22 When connected to form the structure shown in the IB part, the structure shown in the general formula (II) can be transformed into the structure shown in the general formula (II-A).

[0247] When the second functional material G2 is selected from any one of the structures shown in the general formula (II-A), the IB part and the fluorenyl group share an sp3 carbon atom to form a spirocyclic group. Since the spirocyclic group has an orthogonal stereoconfiguration, on the one hand, the stereochemistry of the configuration of the second functional material G2 can be improved, the second functional material G2 can be prevented from crystallizing, and the second functional material G2 can be made to have a higher glass transition temperature. In this way, firstly, the film-forming property of the second functional material G2 can be improved; secondly, the thermal stability of the second functional material G2 can be improved, thereby increasing the life of the light-emitting device 100; secondly, in the structure shown in the general formula (II-A), when the IIB part forms a larger conjugated fragment or a fragment with a stronger electron-donating ability, the HOMO electron cloud and the T1 energy level electron cloud may be distributed in the IIB part; in this way, the HOMO electron cloud and the T1 energy level electron cloud of the second functional material G2 are mainly distributed at the position where the fluorenyl group is located, or at the position where the IIB part is located. Moreover, since in the structure shown in the general formula (II-A), the fluorenyl group and the IIB part share an sp3 carbon atom to form a spirocyclic group, the HOMO electron cloud and the T1 energy level electron cloud can be reduced, and the delocalization from one side of the spirocyclic group to the other side can be reduced, so that the HOMO energy level of the second functional material G2 is relatively deep and the T1 energy level is relatively high; in this way, the leakage of holes and excitons in the light-emitting layer 131 to the cathode 12 side can be blocked, thereby increasing the recombination probability of excitons and improving the efficiency and life of the light-emitting device 100.

[0248] An exemplary structure of the second functional material G2 represented by the general formula (II-A) is described below.

[0249] In some examples, when Y 91 When it is a direct bond, the structural formula of the second functional material G2 can be shown as follows.

[0250] In some examples, when Y 91 When it is substituted carbon, the structural formula of the second functional material G2 can be shown as follows.

[0251] In some examples, when Y 91 When it is oxygen, the structural formula of the second functional material G2 can be shown as follows.

[0252] In some examples, when Y 91 When it is sulfur, the structural formula of the second functional material G2 can be shown as follows.

[0253] It should be noted that the above-listed structural formulas are examples of the structure of the second functional material G2 and are not intended to limit the second functional material G2. Furthermore, (G2-x) in the above structural formulas is a synonym for each structural formula and is not part of the structural formula structure, where x is a positive integer.

[0254] In some embodiments, L 21 The structure is shown in the following structure (IIA).

[0255] Wherein, * indicates the attachment site.

[0256] It should be noted that * represents the connection site, which refers to the position where the connection is formed between IIA and the group connected to it. 21 In the case of the structure shown in structure (IIA), the two connection sites are: triazine group and IIA (ie L 21 ) and the connection site between the phenylene group and IIA (ie L 21 )'s connection site; moreover, the two connection sites are distributed in the meta position.

[0257] It should be noted that when L 21 For the structure shown in (IIA), regarding R 21 and R 22 There is no restriction on the type of choice. 21 and R 22 It may be independently selected from any one of hydrogen, deuterium, halogen, cyano, nitro, hydroxyl, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 5- to 30-membered heteroaryl, and substituted or unsubstituted 3- to 30-membered heterocyclyl; or it may be connected with adjacent groups to form a substituted or unsubstituted 3- to 30-membered ring. In particular, R 21 、R 22 Can be connected to form a six-membered ring, or, R 21 、R 22 can be connected to form the structure shown in Section IIB, or, R 21 、R22 They may all be phenyl or all may be methyl.

[0258] It is understandable that when L 21 When the structure is represented by (IIA), in the structure represented by general formula (II) or general formula (II-A), the triazine group and the fluorenyl group are connected by L 21 The biphenyl group composed of the phenylene group is separated, and the connection point between the fluorenyl group and the phenylene group and the phenylene group and the L 21 The connection sites of phenylene and L are distributed in the meta position; 21 The linking site and L 21 The connection sites with the triazine group are distributed in the meta position; in this way, the separation effect between the fluorenyl group and the triazine group can be improved, and the HOMO electron cloud and the T1 energy level electron cloud distributed on the fluorenyl group (or the IIB part) can be reduced, and the delocalization to the electron-withdrawing group triazine group can be reduced, so that the HOMO energy level of the second functional material G2 is deeper and the T1 energy level is higher; in this way, the holes and excitons in the light-emitting layer 131 can be blocked from leaking to the cathode 12 side, thereby increasing the recombination probability of the excitons and improving the efficiency and life of the light-emitting device 100.

[0259] The following introduces when L 21 For example, the second functional material G2 may have a structure as shown in (IIA). For example, the second functional material G2 may have a structure as shown in (G2-2), (G2-4), (G2-6), (G2-8), (G2-10), (G2-12), (G2-14), (G2-16), (G2-18), (G2-20), (G2-22), (G2-24), (G2-26), (G2-28), (G2-30), (G2-32), (G2-34), (G2-36), (G2-38), (G2-40), (G2-42), (G2-44), (G2-46), (G2-48), (G2-50), (G2-52), (G2-54), (G2-56), (G2-58), (G2-60), (G2-62), (G2-64), (G2-66), (G2-68), (G2-70), (G2-72), (G2-74), (G2-76), (G2-78), (G2-80), (G2-82), (G2- 84), (G2-86), (G2-88), (G2-90), (G2-92), (G2-94), (G2-96), (G2-98), (G2-100), (G2-102), (G2-104), (G2-106), (G2-108), (G2-116).

[0260] In some examples, L 21It is a naphthylene group, and the connection site between the phenylene group and the naphthylene group and the connection site between the naphthylene group and the triazine group are distributed in a meta position.

[0261] By setting it up like this, 21 The same is true for the structure shown in (IIA). The separation effect between the fluorenyl group and the triazine group can be improved, and the HOMO electron cloud and the T1 energy level electron cloud distributed on the fluorenyl group (or IIB part) can be reduced. The delocalization to the electron-withdrawing group triazine group can make the HOMO energy level of the second functional material G2 deeper and the T1 energy level higher. In this way, the holes and excitons in the light-emitting layer 131 can be blocked from leaking to the cathode 12 side, thereby increasing the recombination probability of the excitons and improving the efficiency and life of the light-emitting device 100.

[0262] For example, when L 21 When it is a naphthylene group, and the connection sites between the phenylene group and the naphthylene group and the connection sites between the naphthylene group and the triazine group are distributed in the meta position, the structural formula of the second functional material G2 can be as shown in (G2-110), (G2-112), and (G2-114) above.

[0263] In some embodiments, X 21 、X 22 、X 23 and X 24 is a substituted or unsubstituted carbon.

[0264] It is understandable that when X 21 、X 22 、X 23 and X 24 When the fluorenyl group is substituted or unsubstituted carbon, the structure represented by general formula (II) or general formula (II-A) does not contain a nitrogen atom in the fluorenyl group. Compared to the case where the fluorenyl group contains a nitrogen atom, the electron-donating ability of the fluorenyl group is relatively strong when it does not contain a nitrogen atom, which can cause the HOMO electron cloud and the T1 energy level electron cloud of the second functional material G2 to be distributed at the location of the fluorenyl group. In this way, when the phenylene group separates the fluorenyl group and the triazine group, the HOMO energy level of the second functional material G2 can be deeper and the T1 energy level higher. This can prevent the leakage of holes and excitons in the light-emitting layer 131 to the cathode 12 side, thereby increasing the recombination probability of excitons and improving the efficiency and lifespan of the light-emitting device 100.

[0265] The following introduces when X 21 、X 22 、X 23 and X 24When the carbon atoms are substituted or unsubstituted, the exemplary structures of the second functional material G2 are as follows. For example, the structural formulas of the second functional material G2 may be as shown above: (G2-1), (G2-2), (G2-17), (G2-18), (G2-19), (G2-33) to (G2-36), (G2-49) to (G2-56), (G2-61), (G2-62), (G2-77) to (G2-80), (G2-86), (G2-89), (G2-91), (G2-94), (G2-97), (G2-99), (G2-101), (G2-108), (G2-109), (G2-113), (G2-115), and (G2-116).

[0266] It should be noted that the structural formula listed above is an example of the structure of the second functional material G2, and does not limit the second functional material G2.

[0267] The above is an exemplary introduction to the first functional material G1 and the second functional material G2 in the first functional layer of the light-emitting device 100 . Other film materials (such as the third functional material) in the first functional layer will be introduced below.

[0268] In some embodiments, the first type of functional layer further includes a third functional layer, the third functional layer being located on a side of the first functional layer away from the second functional layer, and the third functional layer comprising a third functional material selected from any one of ytterbium and lithium fluoride.

[0269] When the first functional layer is the electron transport layer 1332 and the second functional layer is the hole blocking layer 1333 , the third functional layer is the electron injection layer 1331 .

[0270] It can be understood that when the first type of functional layer includes a third functional layer, and the material of the third functional layer (i.e., the third functional material) is selected from any one of ytterbium and lithium fluoride, the injection of electrons can be increased. When used in combination with the above-mentioned first functional material G1 and the second functional material G2, better electron injection and electron transport can be achieved, and the distribution of carriers (holes and / or electrons) can be balanced, which can increase electroluminescence, increase the recombination probability of excitons, and improve the efficiency and life of the light-emitting device 100.

[0271] In some examples, the third functional material is ytterbium (e.g., as described in detail in Examples 12 to 14 below); in other examples, the third functional material is lithium fluoride (e.g., as described in detail in Examples 1 to 11 and 15 to 25 below).

[0272] The above is an exemplary introduction to the materials of the first type of functional layer of the light-emitting device 100 . The materials of the light-emitting layer 131 of the light-emitting device 100 will be introduced below.

[0273] In some embodiments, the guest material D is configured to emit blue light.

[0274] It can be understood that when the structure of the first functional material G1 and the structure of the second functional material G2 both contain fluorene groups, and the guest material D is configured to emit blue light, in the first light-emitting device 101, the interface between the first functional layer and the second functional layer can be optimized, which is beneficial to the transmission of electrons between the first functional layer and the second functional layer of the first light-emitting device 101; in this way, the electron transmission effect of the first light-emitting device 101 can be improved, and the electron transmission can be better controlled, so that the electrons and holes in the light-emitting layer 131 are relatively more balanced, and the recombination probability of the excitons is increased, which can meet the electron transmission requirements of the first light-emitting device 101 and improve the efficiency and life of the first light-emitting device 101.

[0275] Compared with the guest material D of the second light-emitting device 102 and the guest material D of the third light-emitting device 103, the guest material D of the first light-emitting device 101 that emits blue light generally has a larger singlet energy level (S1 energy level), a larger triplet energy level (T1 energy level), and the difference between the LUMO energy level and the HOMO energy level is also relatively large. Moreover, as mentioned above, when the display panel 200 includes the first light-emitting device 101, the second light-emitting device 102 and the third light-emitting device 103, the first functional layer (for example, the electron transport layer 1332) and the second functional layer (for example, the hole blocking layer 1333) can be a common film layer shared by multiple light-emitting devices 100. Therefore, compared with the second light-emitting device 102 and the third light-emitting device 103, the first light-emitting device 101 has relatively higher requirements on the electron transport performance of the first functional layer (for example, the electron transport layer 1332) and the second functional layer (for example, the hole blocking layer 1333). When the first functional layer (for example, the electron transport layer 1332) and the second functional layer (for example, the hole blocking layer 1333) meet the electron transport requirements of the first light-emitting device 101, the first functional layer and the second functional layer also meet the electron transport effects of the second light-emitting device 102 and the third light-emitting device 103. In this way, the efficiency and life of the display panel 200 can be improved.

[0276] In some embodiments, the structural formula of the host material H is shown below.

[0277] It is understood that the host material H shown in structure (H-1) is 9,10-di(2-naphthyl)anthracene (ADN), an anthracene core fluorescent material, which can serve as the host material H of the light-emitting device 100 (for example, the first light-emitting device 101) and effectively transfer energy with the guest material D. Exemplarily, the LUMO energy level of the host material H is -2.98 eV, and the HOMO energy level is -5.74 eV.

[0278] When the structure of the second functional material G2 contains a fluorene group (for example, the second functional material G2 is selected from one of the structures shown in general formula (II)), and the structure of the main material H is as shown in (H-1), the difference between the HOMO energy level of the second functional material G2 and the HOMO energy level of the main material H can be within a suitable range, for example, the difference is 0.8 eV. In this way, the leakage of holes to the cathode 12 side can be effectively blocked, the recombination probability of excitons can be increased, the utilization rate of excitons can be increased, and the efficiency and life of the light-emitting device 100 (for example, the first light-emitting device 101) can be improved.

[0279] In some embodiments, the structural formula of the host material H is shown below.

[0280] It is understood that the host material H shown in structure (H-2) is 9,9'-(1,3-phenyl)di-9H-carbazole (MCP), a TADF host material H having high singlet and triplet energy levels (e.g., 2.91 eV), and can be used as the host material H of the light-emitting device 100 (e.g., the first light-emitting device 101), effectively transferring energy with the guest material D. Exemplarily, the LUMO energy level of the host material H is -2.3 eV, and the HOMO energy level is -5.8 eV.

[0281] When the structure of the second functional material G2 contains a fluorene group (for example, the second functional material G2 is selected from one of the structures shown in general formula (II)), and the structure of the main material H is as shown in (H-2), the difference between the HOMO energy level of the second functional material G2 and the HOMO energy level of the main material H can be within an appropriate range. In this way, the leakage of holes to the cathode 12 side can be effectively blocked, the recombination probability of excitons can be increased, the utilization rate of excitons can be increased, and the efficiency and life of the light-emitting device 100 (for example, the first light-emitting device 101) can be improved.

[0282] In some embodiments, the guest material D is selected from any one of a fluorescent material, a phosphorescent material, and a delayed fluorescent material.

[0283] It can be understood that when the structures of the first functional material G1 and the second functional material G2 both contain fluorene groups, and the guest material D is a fluorescent material, the first functional material G1 (for example, the material of the electron transport layer 1332) and the second functional material G2 (for example, the material of the hole blocking layer 1333) can be used to effectively transport electrons to the light-emitting layer 131, thereby improving the electron transport effect of the first type of functional layer. The electrons transported to the light-emitting layer 131 are then recombined with holes from the anode 11 side to produce singlet excitons, and the guest material D uses the singlet excitons to emit light, thereby achieving the purpose of emitting light of a set wavelength.

[0284] When the structures of the first functional material G1 and the second functional material G2 both contain fluorene groups, and the guest material D is a phosphorescent material or a delayed fluorescent material, the first functional material G1 (for example, the material of the electron transport layer 1332) and the second functional material G2 (for example, the material of the hole blocking layer 1333) can be used to effectively transport electrons to the light-emitting layer 131, thereby improving the electron transport effect of the first type of functional layer. The electrons transported to the light-emitting layer 131 then recombine with holes from the anode 11 side to generate triplet excitons, and the guest material D uses the triplet excitons to emit light, thereby achieving the purpose of emitting light of a set wavelength.

[0285] For example, the guest material D may be configured to emit light of a set color; the set color may be red, green, blue, yellow, orange, or white light, etc.

[0286] Exemplarily, when the guest material D is configured to emit blue light, the guest material D can be a pyrene derivative, a fluorene derivative, a perylene derivative, a styrylamine derivative, a metal complex or a TADF material, such as TBPe, BDAVBi, DPAVBi, Firpic, SpiroAC-TRZ or 4CzFCN.

[0287] For example, when the guest material D is configured to emit green light, the guest material D may be a metal complex, such as Ir(ppy)3 or Ir(ppy)2(acac).

[0288] For example, when the guest material D is configured to emit red light, the guest material D may be a metal complex, such as Ir(piq)2(acac), PtOEP, or Ir(btp)2(acac).

[0289] For example, as shown in Examples 1 to 7, 12 to 14, and 19 to 25 described in detail below, the fluorescent material may have the following structure (DPAVBi): The fluorescent material has an absorption peak wavelength of 405 nm and can emit blue light.

[0290] For example, as shown in Example 8 and Example 9 described in detail below, the phosphorescent material may be shown in the following structure (Firpic).

[0291] For example, as shown in Example 10 and Example 11 described in detail below, the delayed fluorescent material may have the following structure (SpiroAC-TRZ).

[0292] In some embodiments, the light emitting device 100 includes at least two light emitting units 13. The material of the second functional layer of each light emitting unit 13 includes a second functional material G2.

[0293] It can be understood that when the material of the second functional layer of each light-emitting unit 13 includes the second functional material G2 (for example, the second functional material G2 having a structure represented by the general formula (II)), the interface between the first functional layer and the second functional layer in each light-emitting unit 13 can be optimized, which is beneficial to the transmission of electrons in each light-emitting unit 13, can improve the overall electron transmission effect of the stacked light-emitting device 100, and can increase the recombination probability of excitons in the light-emitting layer 131 of each light-emitting unit 13, so that the efficiency and life of each light-emitting unit 13 are improved, and the efficiency and life of the light-emitting device 100 can be improved.

[0294] Moreover, when the material of the second functional layer of each light-emitting unit 13 is selected from one of the structures shown in general formula (II), the HOMO electron cloud and the T1 energy level electron cloud of the second functional material G2 in each light-emitting unit 13 are distributed at the position of the fluorene group; and, the phenyl group in the structure shown in general formula (II) can be used to separate the fluorene group and the triazine group to reduce the delocalization of the HOMO electron cloud and the T1 energy level electron cloud distributed on the electron-donating group fluorene group to the electron-withdrawing group triazine group, so that the HOMO energy level of the second functional material G2 is deeper and the T1 energy level is higher; in this way, the holes and excitons in the light-emitting layer 131 can be blocked from leaking to the cathode 12 side, thereby increasing the recombination probability of the excitons, thereby improving the efficiency and life of each light-emitting unit 13, and thus improving the efficiency and life of the light-emitting device 100.

[0295] To objectively evaluate the technical effects of the embodiments of the present disclosure, the technical solutions provided by the present disclosure are described in detail and exemplarily through the following experimental examples and comparative examples. Based on the structure of the light-emitting device 100 and the material of the light-emitting layer 131, the following experimental examples and comparative examples are divided into a first group of experimental examples, a second group of experimental examples, a third group of experimental examples, a fourth group of experimental examples, and a fifth group of experimental examples.

[0296]

First group of experimental examples

[0297] The following embodiments and comparative examples use different materials to make the electron transport layer 1332 (i.e., the first functional layer) and the hole blocking layer 1333 (i.e., the second functional layer) of the first light-emitting device 101, and compare the driving voltage, current efficiency, and device life of the first light-emitting device 101.

[0298] In the following Comparative Example 2 and Examples 1 to 7, the structure of the first light-emitting device 101 is the same. In the following Comparative Example 1, the first type of functional layer (i.e., the electron transport functional layer 133) does not include the hole blocking layer 1333. The structures of the other film layers except the hole blocking layer 1333 are the same as those in Comparative Example 2 and Examples 1 to 7. In the following Comparative Examples 1 and 2 and Examples 1 to 7, the testing conditions of the first light-emitting device 101 are the same.

[0299] As shown in Figure 5, the preparation method of the first light-emitting device 101 is as follows: a substrate 210 provided with an array layer, a pixel defining layer and an anode 11 is used as a substrate, and the substrate is cleaned and dried, and then the substrate is placed in a vacuum evaporation device, using the material of the hole injection layer 1321, the material of the hole transport layer 1322, the material of the electron blocking layer 1323, the material of the light-emitting layer 131, the material of the hole blocking layer 1333, the material of the electron transport layer 1332, the material of the electron injection layer 1331, and the material of the cathode 12 to form a hole injection layer 1321, a hole transport layer 1322, an electron blocking layer 1323, a light-emitting layer 131, a hole blocking layer 1333, an electron transport layer 1332, an electron injection layer 1331, and a cathode 12 on the substrate in sequence.

[0300] It should be noted that the thicknesses of the hole injection layer 1321, hole transport layer 1322, electron blocking layer 1323, light-emitting layer 131, hole blocking layer 1333, electron transport layer 1332, electron injection layer 1331, and cathode 12 in the embodiment and the comparative example are all the same, namely, 10 nm, 110 nm, 5 nm, 20 nm, 5 nm, 30 nm, 1 nm, and 130 nm, respectively. The materials of the anode 11, hole injection layer 1321, hole transport layer 1322, electron blocking layer 1323, light-emitting layer 131, electron injection layer 1331, and cathode 12 in the embodiment and the comparative example are all the same. The anode 11 is made of indium tin oxide (ITO), the hole injection layer 1321 has the following structure (HAT-CN), the hole transport layer 1322 has the following structure (NPB), the electron blocking layer 1323 has the following structure (TCTA), the host material H of the light-emitting layer 131 (EML) has the structure (H-1) above, the guest material D (also known as a blue fluorescent dopant) of the light-emitting layer 131 (EML) has the structure (DPAVBi) above, the electron injection layer 1331 is made of lithium fluoride (LiF), and the cathode 12 is made of aluminum. In the light-emitting layer 131, the mass ratio of host material H to guest material D is 95:5.

[0301] It should be noted that (HAT-CN), (NPB), and (TCTA) in the above structural formulas are aliases for each structural formula and are not part of the structural formula structure.

[0302] The materials of the first functional layer (ie, the electron transport layer 1332ETL) and the second functional layer (ie, the hole blocking layer 1333HBL) of the first light-emitting device 101 of the embodiment and the comparative example are described below.

[0303] In Example 1, the material of the first functional layer is composed of the first functional material G1 having a structure as shown in (G1-18) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1; the structural formula of the material of the second functional layer is shown in (G2-2).

[0304] In Example 2, the material of the first functional layer is composed of the first functional material G1 having a structure as shown in (G1-18) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1; the structural formula of the material of the second functional layer is shown in (G2-18).

[0305] In Example 3, the material of the first functional layer is composed of the first functional material G1 having a structure as shown in (G1-18) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1; the structural formula of the material of the second functional layer is shown in (G2-20).

[0306] In Example 4, the material of the first functional layer is composed of the first functional material G1 having a structure as shown in (G1-18) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1; the structural formula of the material of the second functional layer is shown in (G2-33).

[0307] In Example 5, the material of the first functional layer is composed of the first functional material G1 having a structure as shown in (G1-42) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1; the structural formula of the material of the second functional layer is shown in (G2-18).

[0308] In Example 6, the material of the first functional layer is composed of the first functional material G1 having a structure as shown in (G1-67) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1; the structural formula of the material of the second functional layer is shown in (G2-18).

[0309] In Example 7, the material of the first functional layer is composed of the first functional material G1 having a structure as shown in (G1-97) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1; the structural formula of the material of the second functional layer is shown in (G2-18).

[0310] In Comparative Example 1, the material of the first functional layer is composed of the first functional material G1 having a structure as shown in (G1-18) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1.

[0311] In Comparative Example 2, the material of the first functional layer is composed of the second functional material G2 having a structure as shown in (G2-2) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1; the structural formula of the material of the second functional layer is shown in (G1-18).

[0312] In order to more clearly describe the differences between the materials of the first functional layer (i.e., the electron transport layer 1332ETL) and the materials of the second functional layer (i.e., the hole blocking layer 1333HBL) used in the embodiment and the comparative example, the following Table 1 is used to more clearly show the materials of the first functional layer (i.e., the electron transport layer 1332ETL) and the materials of the second functional layer (i.e., the hole blocking layer 1333HBL) used in the embodiment and the comparative example.

[0313] Based on the above materials, the driving voltage (V), current efficiency (cd / A), and device life of the first light-emitting devices 101 of Examples 1 to 7, as well as Comparative Examples 1 and 2, were tested. The test results for driving voltage (V), current efficiency (cd / A), and device life are shown in Table 1 below, using Comparative Example 1 as a reference. Device life is characterized by the parameter LT95.

[0314] Table 1

[0315] The highest occupied molecular orbital energy level (HOMO), the lowest occupied molecular orbital energy level (LUMO), the triplet energy level (T1), and the electron mobility of the first functional material G1 and the second functional material G2 shown in Table 1 are shown in Table 2.

[0316] Table 2

[0317] It should be noted that "(Ax)" in Tables 1 and 2 refers to the corresponding structural formula as shown in the aforementioned structural formula (Ax). For example, the sub-grid corresponding to the material of the HBL (i.e., hole blocking layer 1333) in Example 1 is "(G2-2)," which means that the structural formula of the material of the HBL (i.e., hole blocking layer 1333) in Example 1 is as shown in the aforementioned structural formula (G2-2). The structural formulas represented by (G1-x), (G2-x) (x is a positive integer), (H-1), and (DPAVBi) are described above and are not further described here.

[0318] It should be noted that the HOMO and LUMO energy levels in Table 2 are measured using AC3&CV&UV spectroscopy, where AC3 is photoelectron spectroscopy, CV is Raman spectroscopy, and UV is ultraviolet spectroscopy; the T1 energy level is measured using low-temperature phosphorescence; and the electron mobility is calculated using the SCLC (space charge limited current technology) method.

[0319] As shown in Table 1, compared with Comparative Examples 1 and 2, Examples 1 to 7 have relatively high current efficiency and device life. This is because the first light-emitting device 101 in Comparative Example 1 does not include a hole blocking layer 1333, while the electron transport layer 1332 in Comparative Example 2 includes the second functional material G2 having a structure (G2-2), and the hole blocking layer 1333 is made of the first functional material G1 having a structure (G1-18). As a result, compared to Examples 1 to 7, Comparative Examples 1 and 2 have relatively poor electron transport performance and relatively poor hole and exciton blocking performance. It can be seen that when the material of the electron transport layer 1332 is a first functional material G1 containing a fluorene group (for example, the first functional material G1 shown in general formula (I)) and the material of the hole blocking layer 1333 is a second functional material G2 containing a fluorene group (for example, the second functional material G2 shown in general formula (II)), the interface between the first functional layer and the second functional layer can be optimized. At the same time, the first functional material G1 and the second functional material G2 are reasonably arranged, which is conducive to the transmission of electrons between the first functional layer and the second functional layer, and can enhance the electron transport effect of the first light-emitting device 101, so that the electrons and holes in the light-emitting layer 131 are relatively more balanced, and the recombination probability of the excitons is increased. In this way, firstly, the exciton yield can be increased, and the efficiency of the first light-emitting device 101 can be improved; secondly, the distribution of carriers can be balanced, and holes or excitons can be blocked from leaking to the cathode 12 side, so that the life of the first light-emitting device 101 can be improved.

[0320] Compared with Comparative Examples 1 and 2, please refer to Table 1. The driving voltages of Examples 1 to 7 are relatively low. This is because the electron transport performance of Comparative Examples 1 and 2 is relatively poor compared to Examples 1 to 7 (for specific reasons, please refer to the above section on current efficiency and device life). It can be seen that when the material of the electron transport layer 1332 is a first functional material G1 containing a fluorene group (for example, the first functional material G1 shown in formula (I)) and the material of the hole blocking layer 1333 is a second functional material G2 containing a fluorene group (for example, the second functional material G2 shown in formula (II)), on the one hand, the electron mobility of the electron transport functional layer 133 is high, and the electron injection and transport effects are good, so that the driving voltage is low; on the other hand, the difference between the LUMO energy level of the material of the electron transport layer 1332 and the LUMO energy level of the hole blocking layer 1333 is relatively small, which can also make the electron injection effect better and the driving voltage relatively low.

[0321] As shown in Table 1, Example 2 shows a relatively higher current efficiency and device lifespan than Example 1. This is because the second functional material G2 with structure (G2-18) has a relatively higher electron mobility than the second functional material G2 with structure (G2-2), resulting in a relatively better balance between electrons and holes in the light-emitting layer 131, which can increase the recombination probability of excitons and improve the efficiency and lifespan of the first light-emitting device 101.

[0322] As shown in Table 1, Example 3 shows a relatively higher current efficiency and device lifespan compared to Example 2. This is because the fluorene group in the second functional material G2, as shown in structure (G2-20), contains nitrogen atoms, resulting in a relatively high electron mobility in the hole blocking layer 1333 of Example 3. In contrast, the fluorene group in the second functional material G2, as shown in structure (G2-18), does not contain nitrogen atoms. In this case, compared to Example 3, the electron mobility of the hole blocking layer 1333 of Example 2 can be within a more suitable range, resulting in a relatively better balance between electrons and holes, thereby improving the efficiency and lifespan of the first light-emitting device 101.

[0323] As shown in Table 1, Example 4 shows a relatively higher current efficiency and device lifespan than Example 2. This is because, compared to the second functional material G2 with structure (G2-18), the second functional material G2 with structure (G2-33) has a relatively shallow HOMO energy level and a relatively low T1 energy level. Therefore, compared to Example 4, the hole blocking layer 1333 in Example 2 exhibits a relatively superior performance in blocking holes and excitons, thereby increasing the recombination probability of excitons and improving the efficiency and lifespan of the first light-emitting device 101.

[0324] As shown in Table 1, compared with Example 2, Examples 5 to 7 have relatively higher current efficiency and device lifespan. This is because, compared to the first functional material G1 with structure (G1-18), the first functional material G1 with structures (G1-42), (G1-67), and (G1-97) has a relatively higher electron mobility. This optimizes the electron injection and transport performance of the first light-emitting device 101, resulting in a relatively better balance between electrons and holes in the light-emitting layer 131, increasing the recombination probability of excitons, and thus improving the efficiency and lifespan of the first light-emitting device 101.

[0325] It can be seen from the above embodiments and comparative examples that when the material of the electron transport layer 1332 of the first light-emitting device 101 is the first functional material G1 described in the present disclosure, the material of the hole blocking layer 1333 is the second functional material G2 described in the present disclosure, and the guest material D is a fluorescent material that emits blue light, the efficiency and device life of the first light-emitting device 101 are high, and the driving voltage is low, thereby achieving the electroluminescent performance of high efficiency, low driving voltage and long life of the first light-emitting device 101.

[0326] [Second group of experimental examples]

[0327] The following embodiments and comparative examples use different materials to make the electron transport layer 1332 (i.e., the first functional layer) and the hole blocking layer 1333 (i.e., the second functional layer) of the first light-emitting device 101, and compare the driving voltage, current efficiency, and device life of the first light-emitting device 101.

[0328] In the following Comparative Examples 4 and 6 and Examples 8 to 11, the structure of the first light-emitting device 101 is the same. In the following Comparative Examples 3 and 5, the first type of functional layer (i.e., the electron transport functional layer 133) does not include the hole blocking layer 1333. The structures of the other film layers other than the hole blocking layer 1333 are the same as those of Examples 8 to 11. In the following Comparative Examples 3 to 6 and Examples 8 to 11, the testing conditions of the first light-emitting device 101 are the same.

[0329] As shown in Figure 5, the preparation method of the first light-emitting device 101 is as follows: a substrate 210 provided with an array layer, a pixel defining layer and an anode 11 is used as a substrate, and the substrate is cleaned and dried, and then the substrate is placed in a vacuum evaporation device, using the material of the hole injection layer 1321, the material of the hole transport layer 1322, the material of the electron blocking layer 1323, the material of the light-emitting layer 131, the material of the hole blocking layer 1333, the material of the electron transport layer 1332, the material of the electron injection layer 1331, and the material of the cathode 12 to form a hole injection layer 1321, a hole transport layer 1322, an electron blocking layer 1323, a light-emitting layer 131, a hole blocking layer 1333, an electron transport layer 1332, an electron injection layer 1331, and a cathode 12 on the substrate in sequence.

[0330] It should be noted that the thicknesses of the hole injection layer 1321, hole transport layer 1322, electron blocking layer 1323, light-emitting layer 131, hole blocking layer 1333, electron transport layer 1332, electron injection layer 1331, and cathode 12 in the embodiment and the comparative example are all the same, namely, 10 nm, 110 nm, 5 nm, 20 nm, 5 nm, 30 nm, 1 nm, and 130 nm, respectively. The materials of the anode 11, hole injection layer 1321, hole transport layer 1322, electron blocking layer 1323, electron injection layer 1331, and cathode 12 in the embodiment and the comparative example are all the same. Among them, the material of the anode 11 is indium tin oxide (ITO), the structure of the material of the hole injection layer 1321 is shown in the above structure (HAT-CN), the structure of the material of the hole transport layer 1322 is shown in the above structure (NPB), the structure of the material of the electron blocking layer 1323 is shown in the above structure (TCTA), the material of the electron injection layer 1331 is lithium fluoride (LiF), and the material of the cathode 12 is aluminum.

[0331] In the materials of the light-emitting layer 131 in the Examples and Comparative Examples, the mass ratio of the host material H to the guest material D is 95:5. The structure of the host material H of the light-emitting layer 131 (EML) in the Examples and Comparative Examples is shown in the above structure (H-2). The structure of the guest material D (also referred to as a blue phosphorescent dopant) of the light-emitting layer 131 (EML) in Examples 8, 9, Comparative Examples 3, and 4 is shown in the above structure (Firpic). The structure of the guest material D (also referred to as a blue TADF dopant) of the light-emitting layer 131 (EML) in Examples 10, 11, Comparative Examples 5, and 6 is shown in the above structure (SpiroAC-TRZ).

[0332] The materials of the first functional layer (ie, the electron transport layer 1332 , ETL) and the second functional layer (ie, the hole blocking layer 1333 , HBL) of the first light-emitting device 101 of the embodiment and the comparative example are described below.

[0333] In Example 8, the material of the first functional layer is composed of the first functional material G1 having a structure as shown in (G1-18) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1; the structural formula of the material of the second functional layer is shown in (G2-2).

[0334] In Example 9, the material of the first functional layer is composed of the first functional material G1 having a structure as shown in (G1-18) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1; the structural formula of the material of the second functional layer is shown in (G2-18).

[0335] In Comparative Example 3, the material of the first functional layer is composed of the first functional material G1 having a structure as shown in (G1-18) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1.

[0336] In Comparative Example 4, the material of the first functional layer is composed of the second functional material G2 having a structure as shown in (G2-2) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1; the structural formula of the material of the second functional layer is shown in (G1-18).

[0337] In Example 10, the material of the first functional layer is composed of the first functional material G1 having a structure as shown in (G1-18) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1; the structural formula of the material of the second functional layer is shown in (G2-2).

[0338] In Example 11, the material of the first functional layer is composed of the first functional material G1 having a structure as shown in (G1-18) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1; the structural formula of the material of the second functional layer is shown in (G2-18).

[0339] In Comparative Example 5, the material of the first functional layer is composed of the first functional material G1 having a structure as shown in (G1-18) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1.

[0340] In Comparative Example 6, the material of the first functional layer is composed of the second functional material G2 having a structure as shown in (G2-2) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1; the structural formula of the material of the second functional layer is shown in (G1-18).

[0341] To more clearly illustrate the differences in the materials of the first functional layer (i.e., electron transport layer 1332, ETL) and the second functional layer (i.e., hole blocking layer 1333, HBL) used in the Examples and Comparative Examples, Table 3 below more clearly shows the materials of the first functional layer (i.e., electron transport layer 1332, ETL) and the second functional layer (i.e., hole blocking layer 1333, HBL) used in Examples 8, 9, Comparative Examples 3, and 4. Table 4 below more clearly shows the materials of the first functional layer (i.e., electron transport layer 1332, ETL) and the second functional layer (i.e., hole blocking layer 1333, HBL) used in Examples 10, 11, Comparative Examples 5, and 6.

[0342] Based on the above materials, the driving voltage (V), current efficiency (cd / A), and device life of the first light-emitting devices 101 of Examples 8 to 11, and Comparative Examples 3 to 6 were tested. In Examples 8, 9, Comparative Examples 3, and 4, the test results for driving voltage (V), current efficiency (cd / A), and device life were based on Comparative Example 3, as shown in Table 3 below. In Examples 10, 11, Comparative Examples 5, and 6, the test results for driving voltage (V), current efficiency (cd / A), and device life were based on Comparative Example 5, as shown in Table 4 below. Device life is characterized by the parameter LT95.

[0343] Table 3

[0344] Table 4

[0345] It should be noted that "(Ax)" in Tables 3 and 4 refers to the corresponding structural formula as shown in the aforementioned structural formula (Ax). For example, the sub-grid corresponding to the material of the HBL (i.e., hole blocking layer 1333) in Example 8 is "(G2-2)," which means that the structural formula of the material of the HBL (i.e., hole blocking layer 1333) in Example 8 is as shown in the aforementioned structural formula (G2-2). The structural formulas represented by (G1-x), (G2-x) (x is a positive integer), (H-2), (SpiroAC-TRZ), and (Firpic) are described above and are not further described here.

[0346] As shown in Table 3, compared with Comparative Examples 3 and 4, Examples 8 and 9 have relatively high current efficiency and device life. This is because the first light-emitting device 101 in Comparative Example 3 does not include a hole blocking layer 1333, while the electron transport layer 1332 in Comparative Example 4 includes the second functional material G2 having a structure (G2-2), and the hole blocking layer 1333 is made of the first functional material G1 having a structure (G1-18). As a result, compared with Examples 8 and 9, Comparative Examples 3 and 4 have relatively poor electron transport performance and relatively poor hole and exciton blocking performance. It can be seen that when the material of the electron transport layer 1332 is the first functional material G1 containing a fluorene group (for example, the first functional material G1 shown in the general formula (I)) and the material of the hole blocking layer 1333 is the second functional material G2 containing a fluorene group (for example, the second functional material G2 shown in the general formula (II)), the interface between the first functional layer and the second functional layer can be optimized. At the same time, the arrangement positions of the first functional material G1 and the second functional material G2 are reasonable, which is conducive to the transmission of electrons between the first functional layer and the second functional layer, and can enhance the electron transport effect of the first light-emitting device 101, increase the recombination probability of excitons, and improve the efficiency and life of the first light-emitting device 101.

[0347] Compared with Comparative Examples 3 and 4, Example 8 and Example 9, please refer to Table 3. The driving voltages of Examples 8 and 9 are relatively low. This is because the electron transport performance of Comparative Examples 3 and 4 is relatively poor compared to that of Examples 8 and 9 (for specific reasons, please refer to the aforementioned section on current efficiency and device life). It can be seen that when the material of the electron transport layer 1332 is a first functional material G1 containing a fluorene group (for example, a first functional material G1 shown in formula (I)) and the material of the hole blocking layer 1333 is a second functional material G2 containing a fluorene group (for example, a second functional material G2 shown in formula (II)), on the one hand, the electron mobility of the electron transport functional layer 133 is high, and the electron injection and transport effects are good, so that the driving voltage is low; on the other hand, the difference between the LUMO energy level of the material of the electron transport layer 1332 and the LUMO energy level of the hole blocking layer 1333 is relatively small, which can also make the electron injection effect better and the driving voltage relatively low.

[0348] As shown in Table 3, Example 9 shows a relatively higher current efficiency and device lifespan compared to Example 8. This is because the second functional material G2 with structure (G2-18) has a relatively higher electron mobility than the second functional material G2 with structure (G2-2), resulting in a relatively better balance between electrons and holes in the light-emitting layer 131, which can increase the recombination probability of excitons and improve the efficiency and lifespan of the first light-emitting device 101.

[0349] As shown in Table 4, when comparing Examples 10 and 11 with Comparative Examples 5 and 6, the current efficiency and device life of Examples 10 and 11 are relatively high. This is because the first light-emitting device 101 in Comparative Example 5 does not include a hole blocking layer 1333, while the electron transport layer 1332 in Comparative Example 6 includes the second functional material G2 having a structure (G2-2), and the hole blocking layer 1333 is made of the first functional material G1 having a structure (G1-18). As a result, compared to Examples 10 and 11, Comparative Examples 5 and 6 have relatively poor electron transport performance and relatively poor hole and exciton blocking performance. It can be seen that when the material of the electron transport layer 1332 is the first functional material G1 containing a fluorene group (for example, the first functional material G1 shown in the general formula (I)) and the material of the hole blocking layer 1333 is the second functional material G2 containing a fluorene group (for example, the second functional material G2 shown in the general formula (II)), the interface between the first functional layer and the second functional layer can be optimized. At the same time, the arrangement positions of the first functional material G1 and the second functional material G2 are reasonable, which is conducive to the transmission of electrons between the first functional layer and the second functional layer, and can enhance the electron transport effect of the first light-emitting device 101, increase the recombination probability of excitons, and improve the efficiency and life of the first light-emitting device 101.

[0350] Compared with Comparative Examples 5 and 6, Example 10 and Example 11, please refer to Table 4. The driving voltages of Examples 10 and 11 are relatively low. This is because the electron transport performance of Comparative Examples 5 and 6 is relatively poor compared to that of Examples 10 and 11 (for specific reasons, please refer to the aforementioned section on current efficiency and device life). It can be seen that when the material of the electron transport layer 1332 is a first functional material G1 containing a fluorene group (for example, a first functional material G1 shown in formula (I)) and the material of the hole blocking layer 1333 is a second functional material G2 containing a fluorene group (for example, a second functional material G2 shown in formula (II)), on the one hand, the electron mobility of the electron transport functional layer 133 is high, and the electron injection and transport effects are good, so that the driving voltage is low; on the other hand, the difference between the LUMO energy level of the material of the electron transport layer 1332 and the LUMO energy level of the hole blocking layer 1333 is relatively small, which can also make the electron injection effect better and the driving voltage relatively low.

[0351] As shown in Table 4, Example 11 shows a relatively higher current efficiency and device lifespan compared to Example 10. This is because the second functional material G2 with structure (G2-18) has a relatively higher electron mobility than the second functional material G2 with structure (G2-2), resulting in a relatively better balance between electrons and holes in the light-emitting layer 131, which can increase the recombination probability of excitons and improve the efficiency and lifespan of the first light-emitting device 101.

[0352] It can be seen from the above embodiments and comparative examples that when the material of the electron transport layer 1332 of the first light-emitting device 101 is the first functional material G1 described in the present disclosure, the material of the hole blocking layer 1333 is the second functional material G2 described in the present disclosure, and the guest material D is a phosphorescent material or a delayed fluorescent material that emits blue light, the efficiency and device life of the first light-emitting device 101 are high, and the driving voltage is low, thereby achieving the electroluminescent performance of high efficiency, low driving voltage and long life of the first light-emitting device 101.

[0353] The third experimental example

[0354] The following embodiments use different materials to make the electron transport layer 1332 (ie, the first functional layer) and the hole blocking layer 1333 (ie, the second functional layer) of the first light-emitting device 101, and compare the driving voltage, current efficiency, and device life of the first light-emitting device 101.

[0355] In the following embodiments 12 to 14, the structures of the first light-emitting devices 101 are all the same, and the test conditions of the first light-emitting devices 101 are all the same.

[0356] As shown in Figure 5, the preparation method of the first light-emitting device 101 is as follows: a substrate 210 provided with an array layer, a pixel defining layer and an anode 11 is used as a substrate, and the substrate is cleaned and dried, and then the substrate is placed in a vacuum evaporation device, using the material of the hole injection layer 1321, the material of the hole transport layer 1322, the material of the electron blocking layer 1323, the material of the light-emitting layer 131, the material of the hole blocking layer 1333, the material of the electron transport layer 1332, the material of the electron injection layer 1331, and the material of the cathode 12 to form a hole injection layer 1321, a hole transport layer 1322, an electron blocking layer 1323, a light-emitting layer 131, a hole blocking layer 1333, an electron transport layer 1332, an electron injection layer 1331, and a cathode 12 on the substrate in sequence.

[0357] It should be noted that the thicknesses of the hole injection layer 1321, the hole transport layer 1322, the electron blocking layer 1323, the light-emitting layer 131, the hole blocking layer 1333, the electron transport layer 1332, the electron injection layer 1331, and the cathode 12 in the embodiment are all the same, namely 10 nm, 110 nm, 5 nm, 20 nm, 5 nm, 30 nm, 1 nm, and 130 nm, respectively. The materials of the anode 11, the hole injection layer 1321, the hole transport layer 1322, the electron blocking layer 1323, the light-emitting layer 131, the electron injection layer 1331, and the cathode 12 in the embodiment are all the same. The anode 11 is made of indium tin oxide (ITO), the hole injection layer 1321 has the structure shown in the aforementioned structure (HAT-CN), the hole transport layer 1322 has the structure shown in the aforementioned structure (NPB), the electron blocking layer 1323 has the structure shown in the aforementioned structure (TCTA), the host material H of the light-emitting layer 131 (EML) has the structure shown in the aforementioned structure (H-1), the guest material D (also known as a blue fluorescent dopant) of the light-emitting layer 131 (EML) has the structure shown in the aforementioned structure (DPAVBi), the electron injection layer 1331 (EIL) has ytterbium (Yb), and the cathode 12 has aluminum. In the light-emitting layer 131, the mass ratio of host material H to guest material D is 95:5.

[0358] The materials of the first functional layer (ie, the electron transport layer 1332ETL) and the second functional layer (ie, the hole blocking layer 1333HBL) of the first light-emitting device 101 of the embodiment are described below.

[0359] In Example 12, the material of the first functional layer is composed of the first functional material G1 having the structure shown in (G1-18) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1; the structural formula of the material of the second functional layer is shown in (G2-2).

[0360] In Example 13, the material of the first functional layer is composed of the first functional material G1 having a structure as shown in (G1-18) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1; the structural formula of the material of the second functional layer is shown in (G2-18).

[0361] In Example 14, the material of the first functional layer is composed of the first functional material G1 having a structure as shown in (G1-18) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1; the structural formula of the material of the second functional layer is shown in (G2-20).

[0362] In order to more clearly describe the differences in the materials of the first functional layer (i.e., the electron transport layer 1332, ETL) and the second functional layer (i.e., the hole blocking layer 1333, HBL) used in the embodiment, the following Table 5 is used to more clearly show the materials of the first functional layer (i.e., the electron transport layer 1332, ETL) and the second functional layer (i.e., the hole blocking layer 1333, HBL) used in the embodiment.

[0363] Based on the above materials, the driving voltage (V), current efficiency (cd / A), and device life of the first light-emitting devices 101 of Examples 12 to 14 were tested. The test results for driving voltage (V), current efficiency (cd / A), and device life were compared with those of Comparative Example 1. The test results are shown in Table 5 below. Device life is characterized by the parameter LT95.

[0364] For the convenience of comparison, Table 5 also lists the materials of Examples 1 to 3 and Comparative Example 1, as well as the test results of driving voltage (V), current efficiency (cd / A), and device life.

[0365] Table 5

[0366] It should be noted that "(Ax)" in Table 5 refers to the corresponding structural formula as shown in the aforementioned structural formula (Ax). For example, the sub-grid corresponding to the material of the HBL (i.e., hole blocking layer 1333) in Example 1 is "(G2-2)," which means that the structural formula of the material of the HBL (i.e., hole blocking layer 1333) in Example 1 is as shown in the aforementioned structural formula (G2-2). The structural formulas represented by (G1-x), (G2-x) (x is a positive integer), (H-1), and (DPAVBi) are as described above and are not further described here.

[0367] As shown in Table 5, Examples 12 to 14 show relatively higher current efficiency and device lifespan compared to Comparative Example 1. This is because the first light-emitting device 101 in Comparative Example 1 lacks a hole-blocking layer 1333 . Consequently, the electron transport performance and hole and exciton blocking performance of Comparative Example 1 are relatively poor compared to Examples 12 to 14. It can be seen that when the material of the electron transport layer 1332 is a first functional material G1 containing a fluorene group (for example, the first functional material G1 shown in general formula (I)) and the material of the hole blocking layer 1333 is a second functional material G2 containing a fluorene group (for example, the second functional material G2 shown in general formula (II)), the interface between the first functional layer and the second functional layer can be optimized. At the same time, the first functional material G1 and the second functional material G2 are reasonably arranged, which is conducive to the transmission of electrons between the first functional layer and the second functional layer, and can enhance the electron transport effect of the first light-emitting device 101, so that the electrons and holes in the light-emitting layer 131 are relatively more balanced, and the recombination probability of the excitons is increased. In this way, firstly, the exciton yield can be increased, and the efficiency of the first light-emitting device 101 can be improved; secondly, the distribution of carriers can be balanced, and holes or excitons can be blocked from leaking to the cathode 12 side, so that the life of the first light-emitting device 101 can be improved.

[0368] Compared with Comparative Example 1, Examples 12 to 14, please refer to Table 5. The driving voltages of Examples 12 to 14 are relatively low. This is because the electron transport performance of Comparative Example 1 is relatively poor compared to Examples 12 to 14 (for specific reasons, please refer to the above section on current efficiency and device life). It can be seen that when the material of the electron transport layer 1332 is the first functional material G1 containing a fluorene group (for example, the first functional material G1 shown in general formula (I)) and the material of the hole blocking layer 1333 is the second functional material G2 containing a fluorene group (for example, the second functional material G2 shown in general formula (II)), on the one hand, the electron mobility of the electron transport functional layer 133 is high, and the electron injection and transport effects are good, which makes the driving voltage lower; on the other hand, the difference between the LUMO energy level of the material of the electron transport layer 1332 and the LUMO energy level of the hole blocking layer 1333 is relatively small, which can also make the electron injection effect better and the driving voltage relatively low.

[0369] Compared with Examples 1 to 3, as shown in Table 5, Examples 12 to 14 show that when the material of the electron injection layer 1331 of the first light-emitting device 101 is ytterbium or lithium fluoride, the material of the electron transport layer 1332 is the first functional material G1 containing a fluorene group (for example, the first functional material G1 represented by formula (I)), and the material of the hole blocking layer 1333 is the second functional material G2 containing a fluorene group (for example, the second functional material G2 represented by formula (II)), the efficiency and device life of the first light-emitting device 101 are both within a relatively high range, and the driving voltage is both within a relatively low range. It can be seen that the first functional material G1 and the second functional material G2 described in the present disclosure, when combined with the material of the electron injection layer 1331, can achieve high efficiency, low driving voltage, and long life electroluminescent performance for the first light-emitting device 101.

[0370]

The fourth group of experimental examples

[0371] The following embodiments and comparative examples use different materials to make the electron transport layer 1332 (i.e., the first functional layer) and the hole blocking layer 1333 (i.e., the second functional layer) of the third light-emitting device 103, and compare the driving voltage, current efficiency, and device life of the third light-emitting device 103.

[0372] In the following Comparative Example 8 and Examples 15 to 18, the structure of the third light-emitting device 103 is the same. In the following Comparative Example 7, the first type of functional layer (i.e., the electron transport functional layer 133) does not include the hole blocking layer 1333. The structures of the other film layers except the hole blocking layer 1333 are the same as those in Comparative Example 8 and Examples 15 to 18. In the following Comparative Examples 7, 8, and Examples 15 to 18, the testing conditions of the third light-emitting device 103 are the same.

[0373] As shown in Figure 5, the preparation method of the third light-emitting device 103 is as follows: a substrate 210 provided with an array layer, a pixel defining layer and an anode 11 is used as a substrate, and the substrate is cleaned and dried, and then the substrate is placed in a vacuum evaporation device, using the material of the hole injection layer 1321, the material of the hole transport layer 1322, the material of the electron blocking layer 1323, the material of the light-emitting layer 131, the material of the hole blocking layer 1333, the material of the electron transport layer 1332, the material of the electron injection layer 1331, and the material of the cathode 12 to form a hole injection layer 1321, a hole transport layer 1322, an electron blocking layer 1323, a light-emitting layer 131, a hole blocking layer 1333, an electron transport layer 1332, an electron injection layer 1331, and a cathode 12 on the substrate in sequence.

[0374] It should be noted that the thicknesses of the hole injection layer 1321, hole transport layer 1322, electron blocking layer 1323, light-emitting layer 131, hole blocking layer 1333, electron transport layer 1332, electron injection layer 1331, and cathode 12 in the embodiment and the comparative example are all the same, namely, 10 nm, 110 nm, 60 nm, 40 nm, 5 nm, 30 nm, 1 nm, and 130 nm, respectively. The materials of the anode 11, hole injection layer 1321, hole transport layer 1322, electron blocking layer 1323, light-emitting layer 131, electron injection layer 1331, and cathode 12 in the embodiment and the comparative example are all the same. Among them, the material of the anode 11 is indium tin oxide (ITO), the structure of the material of the hole injection layer 1321 is shown in the above structure (HAT-CN), the structure of the material of the hole transport layer 1322 is shown in the above structure (NPB), the structure of the material of the electron blocking layer 1323 is shown in the above structure (TCTA), and the host material H of the light-emitting layer 131 (EML) includes a first host material and a second host material, which is conducive to the injection and transport of holes and electrons, and thus facilitates energy transfer to the guest material D. Among them, the structure of the first host material is shown in the following structure (RH-N1), and the structure of the second host material is shown in the following structure (RH-P1). The structure of the guest material D of the light-emitting layer 131 (EML) is shown in the following structure (RD). Moreover, in the light-emitting layer 131, the mass ratio of the first host material, the first host material and the guest material D is 49:49:5. The material of the electron injection layer 1331 is lithium fluoride (LiF), and the material of the cathode 12 is aluminum.

[0375] It should be noted that (RH-N1), (RH-P1), and (RD) in the above structural formulas are aliases for each structural formula and are not part of the structural formula structure.

[0376] The materials of the first functional layer (ie, electron transport layer 1332 , ETL) and the second functional layer (ie, hole blocking layer 1333 , HBL) of the third light-emitting device 103 in the embodiment and comparative example are described below.

[0377] In Example 15, the material of the first functional layer is composed of the first functional material G1 having a structure as shown in (G1-18) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1; the structural formula of the material of the second functional layer is shown in (G2-2).

[0378] In Example 16, the material of the first functional layer is composed of the first functional material G1 having a structure as shown in (G1-18) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1; the structural formula of the material of the second functional layer is shown in (G2-18).

[0379] In Example 17, the material of the first functional layer is composed of the first functional material G1 having a structure as shown in (G1-18) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1; the structural formula of the material of the second functional layer is shown in (G2-20).

[0380] In Example 18, the material of the first functional layer is composed of the first functional material G1 having a structure as shown in (G1-42) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1; the structural formula of the material of the second functional layer is shown in (G2-18).

[0381] In Comparative Example 7, the material of the first functional layer is composed of the first functional material G1 having a structure as shown in (G1-18) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1.

[0382] In Comparative Example 8, the material of the first functional layer is composed of the second functional material G2 having a structure as shown in (G2-2) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1; the structural formula of the material of the second functional layer is shown in (G1-18).

[0383] In order to more clearly describe the differences between the materials of the first functional layer (i.e., the electron transport layer 1332, ETL) and the materials of the second functional layer (i.e., the hole blocking layer 1333, HBL) used in the embodiment and the comparative example, the following Table 6 is used to more clearly show the materials of the first functional layer (i.e., the electron transport layer 1332, ETL) and the materials of the second functional layer (i.e., the hole blocking layer 1333, HBL) used in the embodiment and the comparative example.

[0384] Based on the above materials, the driving voltage (V), current efficiency (cd / A), and device life of the third light-emitting devices 103 of Examples 15 to 18, as well as Comparative Examples 7 and 8, were tested. The test results for driving voltage (V), current efficiency (cd / A), and device life were based on Comparative Example 7, as shown in Table 6 below. Device life was characterized by the parameter LT95.

[0385] Table 6

[0386] It should be noted that "(Ax)" in Table 6 refers to the corresponding structural formula as shown in the aforementioned structural formula (Ax). For example, the sub-grid corresponding to the material of the HBL (i.e., hole blocking layer 1333) in Example 15 is "(G2-2)," which means that the structural formula of the material of the HBL (i.e., hole blocking layer 1333) in Example 15 is as shown in the aforementioned structural formula (G2-2). The structural formulas represented by (G1-x), (G2-x) (x is a positive integer), (RH-N1), (RH-P1), and (RD) are as described above and are not further described here.

[0387] As shown in Table 6, compared with Comparative Examples 7 and 8, Examples 15 to 18 have relatively high current efficiency and device life. This is because the third light-emitting device 103 in Comparative Example 7 does not include a hole blocking layer 1333, while the electron transport layer 1332 in Comparative Example 8 includes the second functional material G2 having a structure (G2-2), and the hole blocking layer 1333 is made of the first functional material G1 having a structure (G1-18). As a result, compared to Examples 15 to 18, Comparative Examples 7 and 8 have relatively poor electron transport performance and relatively poor hole and exciton blocking performance. It can be seen that when the material of the electron transport layer 1332 is a first functional material G1 containing a fluorene group (for example, the first functional material G1 shown in general formula (I)) and the material of the hole blocking layer 1333 is a second functional material G2 containing a fluorene group (for example, the second functional material G2 shown in general formula (II)), the interface between the first functional layer and the second functional layer can be optimized. At the same time, the first functional material G1 and the second functional material G2 are reasonably arranged, which is conducive to the transmission of electrons between the first functional layer and the second functional layer, and can enhance the electron transport effect of the third light-emitting device 103, so that the electrons and holes in the light-emitting layer 131 are relatively more balanced, and the recombination probability of the excitons is increased. In this way, firstly, the exciton yield can be increased, and the efficiency of the third light-emitting device 103 can be improved; secondly, the distribution of carriers can be balanced, and holes or excitons can be blocked from leaking to the cathode 12 side, so that the life of the third light-emitting device 103 can be improved.

[0388] Compared with Comparative Examples 7 and 8, see Table 6. The driving voltages of Examples 15 to 18 are relatively low. This is because the electron transport performance of Comparative Examples 7 and 8 is relatively poor compared to that of Examples 15 to 18 (for a detailed analysis of the reasons, please refer to the previous section on current efficiency and device life). It can be seen that when the material of the electron transport layer 1332 is the first functional material G1 containing a fluorene group (for example, the first functional material G1 represented by formula (I)) and the material of the hole blocking layer 1333 is the second functional material G2 containing a fluorene group (for example, the second functional material G2 represented by formula (II)), on the one hand, the electron mobility of the electron transport functional layer 133 is high, and the electron injection and transport effects are good, resulting in a lower driving voltage. On the other hand, the difference between the LUMO energy level of the material of the electron transport layer 1332 and the LUMO energy level of the hole blocking layer 1333 is relatively small, which can also make the electron injection effect better and the driving voltage of the third light-emitting device 103 relatively low.

[0389] It can be seen from the above embodiments and comparative examples that when the material of the electron transport layer 1332 of the third light-emitting device 103 is the first functional material G1 described in the present disclosure, and the material of the hole blocking layer 1333 is the second functional material G2 described in the present disclosure, the efficiency and device life of the third light-emitting device 103 are high, and the driving voltage is low, thereby achieving the electroluminescent performance of high efficiency, low driving voltage and long life of the third light-emitting device 103.

[0390] [Fifth group of experimental examples]

[0391] The following embodiments and comparative examples use different materials to make the electron transport layer 1332 (i.e., the first functional layer) and the hole blocking layer 1333 (i.e., the second functional layer) of the stacked first light-emitting device 101, and compare the driving voltage, current efficiency, and device life of the first light-emitting device 101.

[0392] In the following comparative example 10 and embodiments 19 to 25, as shown in FIG6 , the structure of the first light-emitting device 101 is the same, and includes a stacked light-emitting device 100 having two light-emitting units 13. Specifically, the first light-emitting device 101 includes an anode 11, a hole injection layer 1321, a first hole transport layer 1322, a first electron blocking layer 1323, a first light-emitting layer 131, a first hole blocking layer 1333 (HBL-1), an electron generation layer 141 (N-type charge generation layer, N-CGL), a hole generation layer 142 (P-type charge generation layer, P-CGL), a second hole transport layer 1322, a second electron blocking layer 1323, a second light-emitting layer 131, a second hole blocking layer 1333 (HBL-2), an electron transport layer 1332 (ETL), an electron injection layer 1331, and a cathode 12, which are arranged in sequence in a direction away from the anode 11. In the following Comparative Example 9, as shown in FIG7 , the second hole blocking layer 1333 (HBL-2) is not included, and the structures of the other film layers except the second hole blocking layer 1333 (HBL-2) are the same as those of Comparative Example 10 and Examples 19 to 25. In the following Comparative Examples 9, 10, and Examples 19 to 25, the testing conditions of the first light-emitting device 101 are the same.

[0393] The preparation method of the first light-emitting device 101 is as follows: a substrate 210 provided with an array layer, a pixel defining layer and an anode 11 is used as a substrate, and the substrate is cleaned and dried, and then the substrate is placed in a vacuum evaporation device, using the material of the hole injection layer 1321, the material of the first hole transport layer 1322, the material of the first electron blocking layer 1323, the material of the first light-emitting layer 131, the material of the first hole blocking layer 1333, the material of the electron generating layer 141, the material of the hole generating layer 142, the material of the second hole transport layer 1322, the material of the second electron blocking layer 1323, the material of the second light-emitting layer 1 31, the material of the second hole blocking layer 1333, the material of the electron transport layer 1332, the material of the electron injection layer 1331 and the material of the cathode 12, and the hole injection layer 1321, the first hole transport layer 1322, the first electron blocking layer 1323, the first light-emitting layer 131, the first hole blocking layer 1333, the electron generating layer 141, the hole generating layer 142, the second hole transport layer 1322, the second electron blocking layer 1323, the second light-emitting layer 131, the second hole blocking layer 1333, the electron transport layer 1332, the electron injection layer 1331 and the cathode 12 are formed in sequence on the substrate.

[0394] It should be noted that the thicknesses of the hole injection layer 1321, the first hole transport layer 1322, the first electron blocking layer 1323, the first light-emitting layer 131, the first hole blocking layer 1333, the electron generating layer 141, the hole generating layer 142, the second hole transport layer 1322, the second electron blocking layer 1323, the second light-emitting layer 131, the second hole blocking layer 1333, the electron transport layer 1332, the electron injection layer 1331 and the cathode 12 in the embodiment and the comparative example are the same, which are 10 nm, 20 nm, 5 nm, 20 nm, 10 nm, 18 nm, 12 nm, 20 nm, 5 nm, 20 nm, 5 nm, 30 nm, 1 nm and 130 nm respectively.

[0395] The materials of the anode 11, hole injection layer 1321, first hole transport layer 1322, first electron blocking layer 1323, first light-emitting layer 131, electron generating layer 141, hole generating layer 142, second hole transport layer 1322, second electron blocking layer 1323, second light-emitting layer 131, electron injection layer 1331 and cathode 12 in the embodiment and the comparative example are the same. The material of the anode 11 is indium tin oxide (ITO); the structure of the material of the hole injection layer 1321 is shown in the above structure (HAT-CN); the structure of the material of the first hole transport layer 1322 and the second hole transport layer 1322 is shown in the above structure (NPB); the structure of the material of the first electron blocking layer 1323 and the second electron blocking layer 1323 is shown in the following structure (TCTA); the structure of the main material H of the first light-emitting layer 131 and the second light-emitting layer 131 is shown in the above structure (H-1), and the structure of the guest material D of the first light-emitting layer 131 and the second light-emitting layer 131 is shown in the above structure (DPAVBi). In the light-emitting layer 131 and the second light-emitting layer 131, the mass ratio of the main material H and the guest material D is 95:5; the material of the electron generation layer 141 includes lithium (Li) and a material having the following structure (N-CGL-1), and the mass ratio of lithium (Li) and the material having the following structure (N-CGL-1) is 1:99; the material of the hole generation layer 142 includes a material having the above structure (NPB) and a material having the above structure (HAT-CN), and the mass ratio of the material having the above structure (NPB) and the material having the above structure (HAT-CN) is 5:95; the material of the electron injection layer 1331 is lithium fluoride (LiF); and the material of the cathode 12 is aluminum.

[0396] In the following embodiments and comparative examples, the material of the first hole blocking layer 1333 includes a comparative material, and the structure of the comparative material is shown in the following formula (HB-1).

[0397] It should be noted that (N-CGL-1) and (HB-1) in the above structural formulas are aliases for each structural formula and are not part of the structural formula structure.

[0398] The following describes the materials of the electron transport layer 1332 (ETL, i.e., the first functional layer) of the first light-emitting device 101 of the embodiment and the comparative example, the materials of the first hole blocking layer 1333 (HBL-1, i.e., the second functional layer of the first light-emitting unit 13 close to the anode 11), and the materials of the second hole blocking layer 1333 (HBL-1, i.e., the second functional layer of the second light-emitting unit 13 close to the cathode 12).

[0399] In Example 19, the material of the electron transport layer 1332 is composed of the first functional material G1 having a structure as shown in (G1-18) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1; the structural formula of the material of the first hole blocking layer 1333 is shown in (HB-1); the structural formula of the material of the second hole blocking layer 1333 is shown in (G2-2).

[0400] In Example 20, the material of the electron transport layer 1332 is composed of the first functional material G1 having a structure as shown in (G1-18) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1; the structural formula of the material of the first hole blocking layer 1333 is shown in (HB-1); the structural formula of the material of the second hole blocking layer 1333 is shown in (G2-18).

[0401] In Example 21, the material of the electron transport layer 1332 is composed of the first functional material G1 having a structure as shown in (G1-18) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1; the structural formula of the material of the first hole blocking layer 1333 is shown in (HB-1); the structural formula of the material of the second hole blocking layer 1333 is shown in (G2-20).

[0402] In Example 22, the material of the electron transport layer 1332 is composed of the first functional material G1 having a structure as shown in (G1-42) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1; the structural formula of the material of the first hole blocking layer 1333 is shown in (HB-1); and the structural formula of the material of the second hole blocking layer 1333 is shown in (G2-18).

[0403] In Example 23, the material of the electron transport layer 1332 is composed of the first functional material G1 having a structure as shown in (G1-18) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1; the structural formula of the material of the first hole blocking layer 1333 is shown in (G2-2); the structural formula of the material of the second hole blocking layer 1333 is shown in (G2-2).

[0404] In Example 24, the material of the electron transport layer 1332 is composed of the first functional material G1 having a structure as shown in (G1-18) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1; the structural formula of the material of the first hole blocking layer 1333 is shown in (G2-18); the structural formula of the material of the second hole blocking layer 1333 is shown in (G2-2).

[0405] In Example 25, the material of the electron transport layer 1332 is composed of the first functional material G1 having a structure as shown in (G1-18) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1; the structural formula of the material of the first hole blocking layer 1333 is shown in (G2-20); the structural formula of the material of the second hole blocking layer 1333 is shown in (G2-2).

[0406] In Comparative Example 9, the material of the electron transport layer 1332 is composed of the first functional material G1 having a structure as shown in (G1-18) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1; the structural formula of the material of the first hole blocking layer 1333 is shown in (HB-1).

[0407] In Comparative Example 10, the material of the electron transport layer 1332 is composed of the first functional material G1 having a structure as shown in (G2-2) and 8-hydroxyquinoline lithium (LiQ), and the mass ratio of the two is 1:1; the structural formula of the material of the first hole blocking layer 1333 is shown in (HB-1); the structural formula of the material of the second hole blocking layer 1333 is shown in (G2-18).

[0408] In order to more clearly describe the differences in the materials of the electron transport layer 1332 (ETL, i.e., the first functional layer), the materials of the first hole blocking layer 1333 (HBL-1, i.e., the second functional layer of the first light-emitting unit 13 close to the anode 11), and the materials of the second hole blocking layer 1333 (HBL-1, i.e., the second functional layer of the second light-emitting unit 13 close to the cathode 12) used in the embodiments and the comparative examples, the following Table 7 is used to more clearly show the materials of the electron transport layer 1332, the materials of the first hole blocking layer 1333, and the materials of the second hole blocking layer 1333 used in the embodiments and the comparative examples.

[0409] Based on the above materials, the driving voltage (V), current efficiency (cd / A), and device life of the first light-emitting devices 101 of Examples 19 to 25, as well as Comparative Examples 9 and 10, were tested. The test results for driving voltage (V), current efficiency (cd / A), and device life were based on Comparative Example 9, as shown in Table 7 below. Device life was characterized by the parameter LT95.

[0410] Table 7

[0411] It should be noted that "(Ax)" in Table 7 refers to the corresponding structural formula as shown in the aforementioned structural formula (Ax). For example, the sub-grid corresponding to the material of HBL-1 (i.e., the first hole blocking layer 1333) in Example 19 is "(HB-1)", which means that the structural formula of the material of HBL-1 (i.e., the first hole blocking layer 1333) in Example 19 is shown in the aforementioned structural formula (HB-1). The structural formulas represented by (G1-x), (G2-x) (x is a positive integer), and (HB-1) are as described above and are not further described here.

[0412] As shown in Table 7, compared with Comparative Examples 9 and 10, Examples 19 to 25 have relatively high current efficiency and device life. This is because the first light-emitting device 101 in Comparative Example 9 does not include a second hole blocking layer 1333, while the electron transport layer 1332 in Comparative Example 10 includes the second functional material G2 having a structure (G2-2), and the second hole blocking layer 1333 is made of the first functional material G1 having a structure (G1-18). As a result, compared to Examples 19 to 25, Comparative Examples 9 and 10 have relatively poor electron transport performance and relatively poor hole and exciton blocking performance. It can be seen that when the material of the electron transport layer 1332 is a first functional material G1 containing a fluorene group (for example, the first functional material G1 shown in general formula (I)) and the material of the hole blocking layer 1333 is a second functional material G2 containing a fluorene group (for example, the second functional material G2 shown in general formula (II)), the interface between the first functional layer and the second functional layer can be optimized. At the same time, the first functional material G1 and the second functional material G2 are reasonably arranged, which is conducive to the transmission of electrons between the first functional layer and the second functional layer, and can enhance the electron transport effect of the first light-emitting device 101, so that the electrons and holes in the light-emitting layer 131 are relatively more balanced, and the recombination probability of the excitons is increased. In this way, firstly, the exciton yield can be increased, and the efficiency of the first light-emitting device 101 can be improved; secondly, the distribution of carriers can be balanced, and holes or excitons can be blocked from leaking to the cathode 12 side, so that the life of the first light-emitting device 101 can be improved.

[0413] Compared with Comparative Examples 9 and 10, as shown in Table 7, Examples 19 to 25 have relatively low driving voltages. This is because the electron transport performance of Comparative Examples 9 and 10 is relatively poor compared to Examples 19 to 25 (for a detailed analysis of the reasons, please refer to the previous section on current efficiency and device life). It can be seen that when the material of the electron transport layer 1332 is a first functional material G1 containing a fluorene group (for example, the first functional material G1 represented by formula (I)) and the material of the hole blocking layer 1333 is a second functional material G2 containing a fluorene group (for example, the second functional material G2 represented by formula (II)), on the one hand, the electron transport functional layer 133 has a high electron mobility, good electron injection and transport effects, and a low driving voltage; on the other hand, the difference between the LUMO energy level of the material of the electron transport layer 1332 and the LUMO energy level of the hole blocking layer 1333 is relatively small, which can also achieve a good electron injection effect and a relatively low driving voltage.

[0414] As shown in Table 7, Examples 23-25 ​​exhibit relatively higher current efficiency and device lifespan compared to Examples 19-22. This is because in Examples 19-22, the material for the second hole-blocking layer 1333 is the second functional material G2, as shown in structure (HB-1), while in Examples 23-25, the material for the second hole-blocking layer 1333 is also the second functional material G2. As a result, compared to Examples 19-22, Examples 23-25 ​​exhibit relatively superior electron transport performance, enhancing the electron transport efficiency of the first light-emitting device 101, improving the balance between electrons and holes within the light-emitting layer 131, and increasing the probability of exciton recombination.

[0415] As shown in Table 7, compared to Examples 19 to 22, Examples 23 to 25 exhibit relatively lower driving voltages. This is because in Examples 19 to 22, the material of the second hole blocking layer 1333 is the second functional material G2, as shown in structure (HB-1), while in Examples 23 to 25, the material of the second hole blocking layer 1333 is the second functional material G2. Consequently, compared to Examples 19 to 22, on the one hand, the electron transport functional layer 133 of Examples 23 to 25 exhibits higher electron mobility, better electron injection and transport, and lower driving voltages. On the other hand, the difference between the LUMO energy level of the material of the electron transport layer 1332 and the LUMO energy level of the hole blocking layer 1333 in Examples 23 to 25 is relatively small, similarly resulting in better electron injection and a relatively low driving voltage.

[0416] It can be seen from the above embodiments and comparative examples that when the material of the electron transport layer 1332 of the stacked first light-emitting device 101 is the first functional material G1 described in the present disclosure, and the material of the hole blocking layer 1333 is the second functional material G2 described in the present disclosure, the efficiency and device life of the first light-emitting device 101 are high, and the driving voltage is low, thereby achieving the electroluminescent performance of high efficiency, low driving voltage and long life of the first light-emitting device 101.

[0417] 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 light-emitting device, comprising: A cathode and an anode disposed opposite to each other, and at least one light-emitting unit disposed between the cathode and the anode; The light-emitting unit includes: a light-emitting layer and a first type of functional layer disposed on a side of the light-emitting layer close to the cathode; the first type of functional layer includes a first functional layer and a second functional layer; the material of the first functional layer includes a first functional material; the material of the second functional layer includes a second functional material; Wherein, the structure of the first functional material contains a fluorenyl group; the structure of the second functional material contains a fluorenyl group.

2. The light-emitting device according to claim 1, wherein The first functional layer is closer to the cathode than the second functional layer; the structure of the first functional material contains an azafluorenyl group.

3. The light-emitting device according to claim 1 or 2, wherein The first functional material is selected from any one of the structures represented by the following general formula (I); Among them, X 11 and X 12 and X 13 and X 14 and X 15 and X 16 and X 17 and X 18 are each independently selected from any one of C(R a ) and N; any two of X 11 and X 12 and X 13 and X 14 and X 15 and X 16 and X 17 and X 18 are the same or different; moreover, at least one of X 11 and X 12 and X 13 and X 14 is N; R 11 、R 12 、R 13 、R 14 and R a are the same or different and are each independently selected from hydrogen, deuterium, halogen, cyano, nitro, hydroxy, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 5- to 30-membered heteroaryl, and substituted or unsubstituted 3- to 30-membered heterocyclic group; or may be linked to an adjacent group to form a substituted or unsubstituted 3- to 30-membered ring; L 11 selected from any one of a direct bond, a substituted or unsubstituted C3-C30 alkylene group, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted 5- to 30-membered heteroarylene group; A is selected from any one of a substituted or unsubstituted C6-C12 aryl group and a substituted or unsubstituted 5- to 12-membered heteroaryl group; n 11 Any one selected from 0, 1, and 2; n 12 Either 0 or 1 is selected.

4. The light-emitting device according to any one of claims 1 to 3, wherein, The second functional material is selected from any one of the structures represented by the following general formula (II); Among them, X 21 , X 22 , X 23 and X 24 are each independently selected from any one of C(R b ) and N; any two of X 21 , X 22 , X 23 and X 24 are the same or different; R 21 、R 22 、R 23 、R 24 and R b are the same or different and are each independently selected from hydrogen, deuterium, halogen, cyano, nitro, hydroxy, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 5- to 30-membered heteroaryl and substituted or unsubstituted 3- to 30-membered heterocyclic group; or may be linked to an adjacent group to form a substituted or unsubstituted 3- to 30-membered ring; L 21 selected from any one of a direct bond, a substituted or unsubstituted C3-C30 alkylene group, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted 5- to 30-membered heteroarylene group; Ar1 and Ar2 are the same or different, and are each independently selected from any one of a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C2-C30 alkenyl group, a substituted or unsubstituted C2-C30 alkynyl group, a substituted or unsubstituted C3-C30 cycloalkyl group, a substituted or unsubstituted C1-C30 alkoxy group, a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted 5- to 30-membered heteroaryl group, and a substituted or unsubstituted 3- to 30-membered heterocyclic group; or may be connected to an adjacent group to form a substituted or unsubstituted 3- to 30-membered ring; n 21 selected from any one of 0, 1, and 2; n 22 Either 0 or 1 is selected.

5. The light-emitting device according to claim 3, wherein, The first functional material is selected from any one of the structures represented by the following general formula (I-A); Among them, X 31 、X 32 、X 33 、X 34 、X 35 、X 36 、X 37 and X 38 are each independently selected from any one of C(R c ) and N; any two of X 31 、X 32 、X 33 、X 34 、X 35 、X 36 、X 37 and X 38 are the same or different; Y 31 Selected from any one of a direct bond, C(R d R e ), O, S, and Se; R c 、R d and R e are the same or different and are each independently selected from hydrogen, deuterium, halogen, cyano, nitro, hydroxy, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 5- to 30-membered heteroaryl, and substituted or unsubstituted 3- to 30-membered heterocyclic group; or may be linked to an adjacent group to form a substituted or unsubstituted 3- to 30-membered ring.

6. The light-emitting device according to claim 3, wherein, R 11 is phenyl; R 12 is phenyl.

7. The light-emitting device according to any one of claims 3 to 6, wherein, A is selected from any one of the structures represented by the following general formula (A1-1), general formula (A1-2), general formula (A1-3) and general formula (A1-4); Wherein, # represents a condensation site; R g and R h are the same or different and are each independently selected from hydrogen, deuterium, halogen, cyano, nitro, hydroxy, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 5- to 30-membered heteroaryl, and substituted or unsubstituted 3- to 30-membered Any one of heterocyclic groups; or may be connected to an adjacent group to form a substituted or unsubstituted 3- to 30-membered ring.

8. The light-emitting device according to any one of claims 3 to 6, wherein, A is selected from any one of the structures represented by the following general formula (A2), general formula (A3), general formula (A4), and general formula (A5); Wherein, # represents a condensation site; X 41 、X 42 、X 43 、X 44 、X 45 、X 46 、X 51 、X 52 、X 53 、X 54 、X 55 、X 56 、X 71 、X 72 、X 73 、X 74 、X 81 、X 82 、X 83 and X 84 are each independently selected from any one of C(R f ) and N; X 41 、X 42 、X 43 、X 44 、X 45 、X 46 、X 51 、X 52 、X 53 、X 54 、X 55 、X 56 、X 71 、X 72 、X 73 、X 74 、X 81 、X 82 、X 83 and X 84 are any two of them, the same or different; Y 81 Selected from C(R i R j ), N(R k ), O, S, and Se; R f 、R i 、R j and R k are the same or different and are each independently selected from hydrogen, deuterium, halogen, cyano, nitro, hydroxy, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 5- to 30-membered heteroaryl, and substituted or unsubstituted 3- to 30-membered heterocyclic group; or may be linked to an adjacent group to form a substituted or unsubstituted 3- to 30-membered ring.

9. The light-emitting device according to claim 8, wherein A is selected from any one of the structures represented by the general formula (A2); moreover, A and the six-membered ring containing X 15 , X 16 , X 17 and X 18 form a phenanthroline group.

10. The light-emitting device according to claim 8, wherein, A is selected from any one of the structures represented by the general formula (A4); moreover, A and the six-membered ring containing X 15 , X 16 , X 17 and X 18 form a benzodiazine group.

11. The light-emitting device according to any one of claims 4 to 10, wherein, The second functional material is selected from any one of the structures represented by the following general formula (II-A); Among them, X 91 、X 92 、X 93 、X 94 、X 95 、X 96 、X 97 and X 98 are each independently selected from any one of C(R n ) and N; any two of X 91 、X 92 、X 93 、X 94 、X 95 、X 96 、X 97 and X 98 are the same or different; Y 91 Selected from any one of a direct bond, C(R o R p ), O, S, and Se; R n 、R o and R p are the same or different and are each independently selected from hydrogen, deuterium, halogen, cyano, nitro, hydroxy, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C2-C30 alkynyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 5- to 30-membered heteroaryl and substituted or unsubstituted 3- to 30-membered heterocyclic group; or may be linked to an adjacent group to form a substituted or unsubstituted 3- to 30-membered ring.

12. The light-emitting device according to any one of claims 4 to 10, wherein, R 21 is phenyl; R 22 is phenyl.

13. The light-emitting device according to any one of claims 4 to 10, wherein R 21 is methyl; R 22 is methyl.

14. The light-emitting device according to any one of claims 4 to 13, wherein, L 21 is the structure shown in the following structure (IIA); Wherein, * represents a connection site.

15. The light-emitting device according to any one of claims 4 to 14, wherein, X 21 、 X 22 、 X 23 and X 24 are substituted or unsubstituted carbons.

16. The light-emitting device according to any one of claims 2 to 15, wherein, The first type of functional layer further includes a third functional layer, and the third functional layer is located on a side of the first functional layer away from the second functional layer; the material of the third functional layer includes a third functional material, and the third functional material is selected from any one of ytterbium and lithium fluoride.

17. The light-emitting device according to any one of claims 1 to 16, wherein, The material of the light-emitting layer includes a host material and a guest material; the guest material is configured to emit blue light.

18. The light-emitting device according to claim 17, wherein, The guest material is selected from any one of a fluorescent material, a phosphorescent material, and a delayed fluorescence material.

19. The light-emitting device according to any one of claims 4 to 18, wherein, The light-emitting device includes at least two light-emitting units, and the at least two light-emitting units are stacked; The light-emitting device further includes a charge generation layer located between two adjacent light-emitting units; The material of the second functional layer of each light-emitting unit includes the second functional material.

20. A display panel, wherein, Including a plurality of light-emitting devices according to any one of claims 1 to 19; Further includes: a driving circuit, and the driving circuit is used to drive the light-emitting device to emit light.

21. A display device, wherein, Including a display panel according to claim 20; Further includes: a driving chip, and the driving chip is used to drive the display panel to display.

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