Light emitting element, light emitting substrate, and display device

Abstract

The present disclosure provides a light-emitting element, a light-emitting substrate and a display device, and belongs to the technical field of display. The light-emitting element comprises an anode, a first hole transport region, a first light-emitting layer, a first electron transport region, a charge generation layer, a second hole transport region, a second light-emitting layer, a second electron transport region, a cathode and a light extraction layer which are sequentially stacked. Through the optimization of the film thickness of the light-emitting element, the material of the charge generation layer and the material of the light extraction layer, the performance of the light-emitting element is improved.

Description

Technical Field

[0001] This disclosure relates to the field of display technology, and more specifically, to a light-emitting element, a light-emitting substrate, and a display device. Background Technology

[0002] Thin-film light-emitting elements (LEDs) possess numerous advantages such as flexibility, self-illumination, and high contrast, leading to their increasingly widespread application in electronic devices. However, the lifespan of thin-film LEDs is one of the limiting factors restricting their further application.

[0003] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0004] The purpose of this disclosure is to overcome the shortcomings of the prior art and provide a light-emitting element, a light-emitting substrate, and a display device to improve the performance of the light-emitting element.

[0005] According to one aspect of this disclosure, a light-emitting element is provided, comprising an anode, a first hole transport region, a first light-emitting layer, a first electron transport region, a charge generation layer, a second hole transport region, a second light-emitting layer, a second electron transport region, a cathode, and a light extraction layer, which are sequentially stacked; the first hole transport region includes a first hole transport layer and a first electron blocking layer stacked.

[0006] Wherein, the total thickness L is the distance between the anode and the cathode; the second dimension L2 is the distance between the first light-emitting layer and the anode; and the third dimension L3 is the distance between the first hole transport layer and the second electron transport region.

[0007] 0.1≤L2 / L3≤0.45;

[0008] 0.5≤L³ / L≤0.0.9;

[0009] The structural formula of the material of the light extraction layer is shown in Chemical Formula 1:

[0010]

[0011] Ar1, Ar2, and Ar3 are each independently selected from aryl groups with 6 to 60 substituted or unsubstituted carbon atoms, or heteroaryl groups with 5 to 60 substituted or unsubstituted carbon atoms, and at least one is selected from the structure shown in Formula 2.

[0012] L a L bEach is independently selected from arylene groups with 6 to 60 carbon atoms (single bond, substituted or unsubstituted) and heteroarylene groups with 2 to 60 carbon atoms (substituted or unsubstituted);

[0013] X is selected from O, S, C(R1R2) or NR3;

[0014] R1, R2, and R3 are each independently selected from alkyl groups having 1 to 10 carbon atoms, cycloalkyl groups having 5 to 10 carbon atoms, aryl groups having 6 to 20 carbon atoms, and heteroaryl groups having 5 to 20 carbon atoms;

[0015] The charge generation layer includes an N-type charge generation layer stacked on the side of the first electron transport region away from the anode and a P-type charge generation layer located on the side of the N-type charge generation layer away from the anode; the structural formula of the main material of the N-type charge generation layer is shown in Chemical Formula 3:

[0016]

[0017] Among them, X1, X2, X3, and X4 are each independently selected from N or C(R4), and at least two of X1, X2, X3, and X4 are selected from N;

[0018] R4 may appear the same or different each time, and each is independently selected from hydrogen, deuterium, substituted or unsubstituted alkyl with 1 to 60 carbon atoms, substituted or unsubstituted alkenyl with 2 to 60 carbon atoms, substituted or unsubstituted alkynyl with 2 to 60 carbon atoms, substituted or unsubstituted alkoxy with 1 to 60 carbon atoms, substituted or unsubstituted cycloalkyl with 3 to 10 carbon atoms, substituted or unsubstituted heterocyclic alkyl with 1 to 10 carbon atoms, substituted or unsubstituted Cycloalkenyl groups with 3 to 10 carbon atoms, heterocyclic alkenyl groups with 1 to 10 substituted or unsubstituted carbon atoms, aryl groups with 6 to 60 substituted or unsubstituted carbon atoms, aryloxy groups with 6 to 60 substituted or unsubstituted carbon atoms, arylthio groups with 6 to 60 substituted or unsubstituted carbon atoms, heteroaryl groups with 1 to 60 substituted or unsubstituted carbon atoms, monovalent non-aromatic condensed polycyclic groups with substituted or unsubstituted carbon atoms, and monovalent non-aromatic condensed heteropolycyclic groups with substituted or unsubstituted carbon atoms;

[0019] Ar4, Ar5, Ar6, and Ar7 may be the same or different, and each is independently selected from the group consisting of: hydrogen, deuterium, tritium, halogen, cyano, nitro, aryl group with 6 to 60 substituted or unsubstituted carbon atoms, heterocyclic group with 2 to 60 substituted or unsubstituted carbon atoms containing at least one heteroatom from O, N, S, Si, and P, aliphatic ring with 3 to 60 substituted or unsubstituted carbon atoms, fused ring group of aromatic ring with 6 to 60 substituted or unsubstituted carbon atoms, and substituted or unsubstituted... Alkyl groups having 1 to 50 carbon atoms, alkenyl groups having 2 to 20 carbon atoms (substituted or unsubstituted), alkynyl groups having 2 to 20 carbon atoms (substituted or unsubstituted), alkoxy groups having 1 to 30 carbon atoms (substituted or unsubstituted), aryloxy groups having 6 to 30 carbon atoms (substituted or unsubstituted), alkylsilyl groups having 3 to 60 carbon atoms (substituted or unsubstituted), arylsilyl groups having 18 to 60 carbon atoms (substituted or unsubstituted), and alkylarylsilyl groups having 8 to 60 carbon atoms (substituted or unsubstituted).

[0020] The structural formula of the doped material of the P-type charge generation layer is shown in chemical formula 4:

[0021]

[0022] Among them, X5 and X6 are each independently selected from C(Rg), N, and Si(Rg);

[0023] Y1 and Y2 are each independently selected from N(Rh), O, and S;

[0024] Ra, Rb, Rc, Rd, Rg, and Rh are each independently selected from halogens, cyano groups, substituted or unsubstituted phenyl groups, substituted or unsubstituted biphenyl groups, substituted or unsubstituted terphenyl groups, substituted or unsubstituted fluorene groups, substituted or unsubstituted adamantane groups, and substituted or unsubstituted heteroaryl groups.

[0025] Re and Rf are each independently selected from deuterium, halogen groups, cyano, heteroaryl groups with 3 to 20 substituted or unsubstituted carbon atoms, aryl groups with 6 to 20 substituted or unsubstituted carbon atoms, alkyl groups with 1 to 5 substituted or unsubstituted carbon atoms, haloalkyl groups with 1 to 10 substituted or unsubstituted carbon atoms, cycloalkyl groups with 3 to 10 substituted or unsubstituted carbon atoms, heterocycloalkyl groups with 2 to 10 substituted or unsubstituted carbon atoms, alkoxy groups with 1 to 10 substituted or unsubstituted carbon atoms, alkylthio groups with 1 to 10 substituted or unsubstituted carbon atoms, aryloxy groups with 6 to 18 substituted or unsubstituted carbon atoms, arylthio groups with 6 to 18 carbon atoms, phosphoxy groups with 6 to 24 carbon atoms, and alkylsulfonyl groups with 6 to 18 substituted or unsubstituted carbon atoms.

[0026] a and b are independent integers from 1 to 5.

[0027] According to another aspect of this disclosure, a light-emitting substrate is provided, comprising at least one of the aforementioned light-emitting elements.

[0028] According to another aspect of this disclosure, a display device is provided, including the above-described light-emitting substrate.

[0029] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0030] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0031] Figure 1 This is a schematic diagram of the structure of the display panel in one embodiment of the present disclosure.

[0032] Figure 2 This is a schematic diagram of the planar structure of the display panel in one embodiment of the present disclosure.

[0033] Figure 3 This is a cross-sectional structural diagram of the display panel in one embodiment of the present disclosure.

[0034] Figure 4 This is a schematic diagram of the structure of a light-emitting element in one embodiment of the present disclosure.

[0035] Figure 5 This is a schematic diagram of the structure of an OLED in one embodiment of the present disclosure.

[0036] Figure 6 This is a schematic diagram of the structure of a red light-emitting element in one embodiment of the present disclosure.

[0037] Figure 7 This is a schematic diagram of the structure of a green light-emitting element in one embodiment of the present disclosure.

[0038] Figure 8 This is a schematic diagram of the structure of a blue light-emitting element in one embodiment of the present disclosure.

[0039] Figure 9 This is a schematic diagram of the structure of a light-emitting element in one embodiment of the present disclosure. Detailed Implementation

[0040] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore detailed descriptions of them will be omitted. Furthermore, the drawings are merely illustrative of this disclosure and are not necessarily drawn to scale.

[0041] Although relative terms such as "up" and "down" are used in this specification to describe the relative relationship of one component of an icon to another, these terms are used only for convenience, such as according to the orientation of the examples shown in the accompanying drawings. It is understood that if the device of the icon is flipped upside down, the component described as "up" will become the component described as "down." When a structure is "up" of another structure, it may mean that the structure is integrally formed on the other structure, or that the structure is "directly" mounted on the other structure, or that the structure is "indirectly" mounted on the other structure through another structure.

[0042] The terms “a,” “one,” “the,” “the,” and “at least one” are used to indicate the presence of one or more elements / components / etc.; the terms “including” and “having” are used to indicate an open-ended inclusion and to mean that there may be other elements / components / etc. in addition to the listed elements / components / etc.; the terms “first,” “second,” and “third,” etc., are used only as markers and are not a limitation on the number of objects.

[0043] Structural layer A is located on the side of structural layer B that faces away from the substrate. This can be understood as structural layer A being formed on the side of structural layer B that faces away from the substrate. When structural layer B is a patterned structure, some structures of structural layer A may also be located at the same physical height as structural layer B or at a lower physical height than structural layer B, where the substrate serves as the height reference.

[0044] In this disclosure, the term "substituted or unsubstituted" means that the functional group described after the term may or may not have substituents (hereinafter, for ease of description, substituents are collectively referred to as Rx). For example, "substituted or unsubstituted aryl" refers to an aryl group having a substituent Rx or an unsubstituted aryl group. The substituent Rx can be, for example, deuterium, halogen groups, cyano, alkyl, alkoxy, alkylthio, haloalkyl, deuteralkyl, cycloalkyl, trialkylsilyl, triphenylsilyl, diarylphosphine, aryloxy, etc. In this disclosure, the "substituted" functional group can be substituted by one or more of the aforementioned substituents Rx.

[0045] In embodiments of this disclosure, the number of carbon atoms in substituted or unsubstituted groups refers to the total number of carbon atoms. For example, if Ar x If an aryl group is substituted with 12 carbon atoms, then the total number of carbon atoms in the aryl group and its substituents is 12.

[0046] The descriptive phrases used in this disclosure, such as "...each independently selected" and "...independently selected each time it appears," can mean that the specific options expressed by the same symbol in different groups do not affect each other, or that the specific options expressed by the same symbol in the same group do not affect each other. For example: in " In this formula, each q is independently 0, 1, 2 or 3, and each R is independently selected from the description of hydrogen, fluorine or chlorine. The meaning is as follows: Formula Q-1 indicates that there are q substituents R on the benzene ring. Each R can be the same or different, and the options of each R do not affect each other. Formula Q-2 indicates that there are q substituents R on each benzene ring of biphenyl. The number q of substituents R on the two benzene rings can be the same or different, and each R can be the same or different. The options of each R do not affect each other.

[0047] In this disclosure, aryl refers to any optional functional group or substituent derived from an aromatic hydrocarbon ring. The aryl group can be a monocyclic aryl (e.g., phenyl) or a polycyclic aryl; in other words, the aryl group can be a monocyclic aryl, a fused-ring aryl, two or more monocyclic aryl groups conjugated by carbon-carbon bonds, a monocyclic aryl and a fused-ring aryl group conjugated by carbon-carbon bonds, or two or more fused-ring aryl groups conjugated by carbon-carbon bonds. That is, two or more aromatic groups conjugated by carbon-carbon bonds can also be considered as aryl groups in this disclosure. Fused-ring aryl groups may include, for example, bicyclic fused aryl (e.g., naphthyl), tricyclic fused aryl (e.g., phenanthrene, fluorenyl, anthracene), etc. The aryl group does not contain heteroatoms such as B, N, O, S, Se, Si, or P. For example, in this disclosure, biphenyl, terphenyl, etc., are aryl groups. Examples of aryl groups may include phenyl, naphthyl, fluorenyl, anthracene, phenanthryl, biphenyl, terphenyl, tetraphenyl, benzo[9,10]phenanthryl, pyrene, benzofluoranthracene, etc. Indene, etc., but not limited to these.

[0048] In embodiments of this disclosure, the substituted aryl group may be one or more hydrogen atoms of the aryl group that are replaced by groups such as deuterium atoms, halogen groups, -CN, aryl, heteroaryl, trialkylsilyl, alkyl, cycloalkyl, alkoxy, alkylthioyl, etc. Specific examples of heteroaryl-substituted aryl groups include, but are not limited to, dibenzofuranyl-substituted phenyl, dibenzothiopheneyl-substituted phenyl, pyridyl-substituted phenyl, carbazoleyl-substituted phenyl, etc. It should be understood that the number of carbon atoms in the substituted aryl group refers to the total number of carbon atoms of the aryl group and the substituents on the aryl group. For example, a substituted aryl group with 18 carbon atoms means that the total number of carbon atoms of the aryl group and the substituents is 18.

[0049] In embodiments of this disclosure, a heteroaryl group refers to a monovalent aromatic ring or its derivative containing at least one heteroatom, where the heteroatom can be at least one of B, O, N, P, Si, Se, and S. The heteroaryl group can be a monocyclic or polycyclic heteroaryl group; in other words, it can be a single aromatic ring system or a system of multiple aromatic rings conjugated by carbon-carbon bonds, and any aromatic ring system can be a single aromatic monocyclic ring or a fused aromatic ring. For example, heteroaryl groups may include thiophene, furanyl, pyrrole, imidazolyl, thiazolyl, oxazolyl, oxadiazolyl, triazolyl, pyridyl, bipyridyl, pyrimidinyl, triazinyl, acridinel, pyridazinyl, pyrazinyl, quinolinyl, quinazolinyl, quinoxolinyl, phenoxazinyl, phthalazinyl, pyridopyrimidinyl, pyridopyrazinyl, isoquinolinyl, indolyl, carbazole, benzoxazolyl, and benzimidazole. The group includes, but is not limited to, benzothiazolyl, benzocarbazolyl, benzothiophenel, dibenzothiophenel, thienozothiophenel, benzofuranyl, phenanthrolinel, isoxazolyl, thiadiazolyl, benzothiazolyl, phenothiazinyl, silanyl, dibenzofuranyl, and N-arylcarbazolyl (such as N-phenylcarbazolyl), N-heteroarylcarbazolyl (such as N-pyridylcarbazolyl), and N-alkylcarbazolyl (such as N-methylcarbazolyl), etc. Among these, thiophenel, furanyl, and phenanthrolinel are heteroaryl groups of the single aromatic ring type, while N-arylcarbazolyl and N-heteroarylcarbazolyl are heteroaryl groups of the polycyclic system type linked by carbon-carbon conjugation.

[0050] In embodiments of this disclosure, the substituted heteroaryl group may be one or more hydrogen atoms of the heteroaryl group that are replaced by groups such as deuterium atoms, halogen groups, -CN, aryl, heteroaryl, trialkylsilyl, alkyl, cycloalkyl, alkoxy, alkylthioyl, etc. Specific examples of aryl-substituted heteroaryl groups include, but are not limited to, phenyl-substituted dibenzofuranyl, phenyl-substituted dibenzothiophenyl, phenyl-substituted pyridyl, etc. It should be understood that the number of carbon atoms in the substituted heteroaryl group refers to the total number of carbon atoms of the heteroaryl group and the substituents on the heteroaryl group.

[0051] In this embodiment of the disclosure, a non-positioned connecting key refers to a single bond extending from the ring system. This means that one end of the linking bond can be connected to any position in the ring system that the bond passes through, and the other end is connected to the rest of the compound molecule.

[0052] For example, as shown in equation (f) below, the naphthyl group represented by equation (f) is connected to other positions in the molecule through two non-positional linkages that span the bicyclic ring. This means that any possible connection mode is shown in equations (f-1) to (f-10).

[0053]

[0054] For another example, as shown in equation (X'), the phenanthrene group represented by equation (X') is connected to other positions in the molecule via a non-positional linker extending from the middle of one side of the benzene ring. This means that any possible connection mode shown in equations (X'-1) to (X'-4) is included.

[0055]

[0056] In the embodiments of this disclosure, a non-positional substituent refers to a substituent connected by a single bond extending from the center of the ring system, indicating that the substituent can be attached to any possible position in the ring system. For example, as shown in the following formula (Y), the substituent R' group represented by formula (Y) is connected to the quinoline ring by a non-positional linking bond, which means that it includes any possible connection mode shown in formulas (Y-1) to (Y-7).

[0057]

[0058] This disclosure provides a light-emitting substrate and a light-emitting device including the light-emitting substrate. See also Figure 1 The light-emitting substrate PNL includes at least one light-emitting element (LD), which is a thin-film current-driven light-emitting element. For example, the light-emitting element LD can be QLED, OLED, or PLED. In one example, the light-emitting device can be a lighting device (e.g., vehicle headlights, ambient lights, bedside lamps, etc.), thus the light-emitting substrate PNL can be a lighting panel. In another example, the light-emitting device can be a display device for displaying static or dynamic images, such as a smartphone screen, television screen, smartwatch screen, computer monitor screen, vehicle display screen, smart picture frame screen, or other types of display devices. Accordingly, the light-emitting substrate PNL can be a display panel. It is understood that the light-emitting substrate provided in this disclosure can also be used in other fields requiring a light source besides lighting or display.

[0059] exist Figure 1In the example, the light-emitting substrate PNL includes three different colored light-emitting elements (LDs): a red light-emitting element (RLD), a green light-emitting element (GLD), and a blue light-emitting element (BLD). It is understood that in other embodiments of this disclosure, the light-emitting substrate PNL may include only one color of light-emitting element (LD), such as only one of a red light-emitting element (RLD), a green light-emitting element (GLD), or a blue light-emitting element (BLD); in other embodiments of this disclosure, the light-emitting substrate PNL may also include light-emitting elements (LDs) of other colors, such as yellow light-emitting elements, white light-emitting elements, etc.

[0060] In one example, the light-emitting substrate PNL is a display panel and includes at least three different colored light-emitting elements (LDs). For example, the light-emitting substrate PNL includes multiple light-emitting elements (LDs) arranged in an array, and some of the light-emitting elements (LDs) are red light-emitting elements (RLDs), some are green light-emitting elements (GLDs), and some are blue light-emitting elements (BLDs). Furthermore, some of the light-emitting elements (LDs) on the light-emitting substrate PNL can be white light-emitting elements.

[0061] The following is an exemplary description of the structure of a light-emitting substrate PNL, taking it as an example of a display panel.

[0062] Figure 2 This is a schematic diagram of the planar structure of the light-emitting substrate PNL in this example. See also Figure 2 The light-emitting substrate PNL serves as a display panel, including a display area AA and a peripheral area BB located on at least one side of the display area AA. In the display area AA, the light-emitting substrate PNL is provided with an array of display units DU, each display unit DU including a light-emitting element LD as a sub-pixel PX and a pixel driving circuit PDC driving the sub-pixel PX. The light-emitting substrate PNL does not have display units DU in the peripheral area BB, or the provided display units DU are not used for displaying images. Figure 2In the example, the light-emitting substrate PNL has multiple scan lines GL extending along the row direction DH in the display area AA, with each scan line GL corresponding to a row of display units. The pixel driving circuit PDC of each display unit DU in each row of display units is electrically connected to the corresponding scan line GL. The light-emitting substrate PNL also has multiple data lines DL extending along the column direction DV in the display area AA, with each data line DL corresponding to a column of display units. The pixel driving circuit PDC of each display unit DU in each column of display units is electrically connected to the corresponding data line DL. Thus, the pixel driving circuit PDC of each display unit DU is connected to one scan line GL and one data line DL. When a scan signal is applied to the scan line GL, the driving voltage applied to the data line DL can be written into the pixel driving circuit PDC, thereby allowing the pixel driving circuit PDC to control the brightness of the sub-pixel PX according to the written driving voltage. It is understood that in other embodiments of this disclosure, the arrangement of the display units DU and the connection method with the data lines DL, scan lines GL, etc., can also be different from... Figure 2 The examples are different.

[0063] Figure 3 This is a partial cross-sectional schematic diagram of the light-emitting substrate PNL in this example. Figure 3 In the example, the light-emitting substrate PNL may include a substrate SBT, a driving layer DRL, and a pixel layer PXL stacked sequentially. The pixel layer PXL contains light-emitting elements LDs that serve as sub-pixels PX, and the driving layer DRL contains a pixel driving circuit PDC for driving the sub-pixels PX. Each sub-pixel PX can emit light under the drive of the pixel driving circuit PDC to display an image.

[0064] Optionally, the substrate SBT can be an inorganic material substrate or an organic material substrate; of course, it can also be a composite substrate formed by stacking inorganic and organic material substrates. For example, in some embodiments of this disclosure, the material of the substrate SBT can be glass materials such as soda-lime glass, quartz glass, and sapphire glass. In other embodiments of this disclosure, the material of the substrate SBT can be polymethyl methacrylate, polyvinyl alcohol, polyvinylphenol, polyethersulfone, polyimide, polyamide, polyacetal, polycarbonate, polyethylene terephthalate, polyethylene naphthalate, or combinations thereof. In other embodiments of this disclosure, the substrate SBT can also be a flexible substrate, for example, the material of the substrate SBT can be polyimide.

[0065] Optionally, in the driving layer DRL, any pixel driving circuit PDC may include a transistor (e.g., a thin-film transistor) and a storage capacitor. Further, the transistor may be selected from top-gate thin-film transistors, bottom-gate thin-film transistors, or dual-gate thin-film transistors; the material of the active layer of the thin-film transistor may be amorphous silicon semiconductor material, low-temperature polycrystalline silicon semiconductor material, metal oxide semiconductor material, organic semiconductor material, carbon nanotube semiconductor material, or other types of semiconductor material; the thin-film transistor may be an N-type thin-film transistor or a P-type thin-film transistor.

[0066] It is understood that any two transistors in a pixel driving circuit can be of the same or different types. Exemplarily, in some embodiments, some transistors in a pixel driving circuit can be N-type transistors and some transistors can be P-type transistors. Further exemplarily, in other embodiments, in a pixel driving circuit, the active layer material of some transistors can be low-temperature polycrystalline silicon (LTPS) semiconductor material, and the active layer material of some transistors can be metal-oxide-semiconductor (MODS) semiconductor material. In some embodiments of this disclosure, the thin-film transistor is a LPS transistor. In other embodiments of this disclosure, some thin-film transistors are LPS transistors, and some thin-film transistors are MODS transistors.

[0067] Optionally, the driving layer DRL may include a semiconductor layer SCL, a gate insulating layer GI, a gate layer GT, an interlayer dielectric layer ILD, a source / drain metal layer SD, and a planarization layer PLN, stacked between the substrate SBT and the pixel layer PXL. Each thin-film transistor and storage capacitor can be formed from the semiconductor layer SCL, gate insulating layer GI, gate layer GT, interlayer dielectric layer ILD, and source / drain metal layer SD. The positional relationship of each layer can be determined based on the thin-film transistor's layer structure. Further, the semiconductor layer SCL can be used to form the channel region of the transistor, and can also be used to form partial traces or conductive structures if necessary. The gate layer can be used to form one or more gate layer traces such as scan traces, reset control traces, and light emission control traces, or it can be used to form the gate of the transistor, or it can be used to form part or all of the electrode plates of the storage capacitor. The source / drain metal layer can be used to form data traces, drive power supply voltage traces, or other source / drain metal layer traces, or it can be used to form part of the electrode plates of the storage capacitor. Of course, in other embodiments of this disclosure, the driving layer DRL may also include other film layers as needed, such as a light-shielding layer located between the semiconductor layer SCL and the substrate SBT. As needed, any one of the aforementioned semiconductor layer SCL, gate layer GT, source / drain metal layer SD may be multiple layers. For example, the driving layer DRL may include two different semiconductor layers SCL, or two or three source / drain metal layers SD, or two or three gate layers GT. Correspondingly, the insulating film layers in the driving layer DRL (e.g., gate insulating layer GI, interlayer dielectric layer ILD, planarization layer PLN, etc.) may be adaptively increased or decreased, or new insulating film layers may be added as needed. Optionally, the driving layer DRL may also include a passivation layer, which may be disposed on the surface of the source / drain metal layer SD away from the substrate SBT to protect the source / drain metal layer SD.

[0068] In one embodiment of this disclosure, the film layer between the substrate SBT and the first source / drain metal layer SD1 can be referred to as a single unit as a transistor layer TFTL. The transistor layer TFTL has a semiconductor layer SCL, a gate insulating layer GI, and a gate layer GT required for forming thin-film transistors. The structure between the transistor layer TFTL and the pixel layer PXL can also be referred to as a wiring layer MRL. One important function of the wiring layer MRL is to realize electrical connections between different devices, such as electrical connections between thin-film transistors, storage capacitors, and sub-pixels PX. Optionally, the wiring layer MRL may include one or more wiring unit layers, each wiring unit layer may include a source / drain metal layer SD and a planarization layer PLN located on the side of the source / drain metal layer SD away from the substrate SBT. It is understood that in some examples, the wiring unit layer may also include a passivation layer, which may be disposed between the source / drain metal layer SD and the planarization layer PLN to protect the source / drain metal layer SD.

[0069] For example, in Figure 3 In the example, the transistor layer TFTL includes a first inorganic buffer layer BUFA, a polysilicon semiconductor layer PSCL, a first gate insulating layer GI1, a first gate layer GT1, a second inorganic buffer layer BUFB, a second gate layer GT2, a second gate insulating layer GI2, a metal oxide semiconductor layer OSCL, a third gate insulating layer GI3, a second gate layer GT2, and an interlayer dielectric layer ILD, all sequentially stacked on one side of the transistor layer TFTL away from the substrate SBT. The wiring layer MRL includes a first source / drain metal layer SD1, a first planarization layer PLN1, a second source / drain metal layer SD2, a second planarization layer PLN2, a third source / drain metal layer SD3, and a third planarization layer PLN3, all sequentially stacked on the side of the transistor layer TFTL away from the substrate SBT. Thus, the wiring layer MRL comprises three wiring unit layers: a first wiring unit layer (including a first source / drain metal layer SD1 and a first planarization layer PLN1), a second wiring unit layer (including a second source / drain metal layer SD2 and a second planarization layer PLN2), and a third wiring unit layer (including a third source / drain metal layer SD3 and a third planarization layer PLN3). When the light-emitting substrate PNL requires more source / drain metal layers SD, the number of wiring unit layers can be adaptively increased (i.e., the source / drain metal layers SD and planarization layers PLN are added simultaneously).

[0070] exist Figure 3In the example, the driving layer DRL includes two semiconductor layers SCL (polysilicon semiconductor layer PSCL and metal oxide semiconductor layer OSCL), three gate insulating layers GI (first gate insulating layer GI1, second gate insulating layer GI2, and third gate insulating layer GI3), three gate layers GT (first gate layer GT1, second gate layer GT2, and third gate layer GT3), three source drain metal layers SD (first source drain metal layer SD1, second source drain metal layer SD2, and third source drain metal layer SD3), and three planarization layers PLN (first planarization layer PLN1, second planarization layer PLN2, and third planarization layer PLN3). The polysilicon semiconductor layer PSCL, the first gate insulating layer GI1, and the first gate layer GT1 can form low-temperature polysilicon thin-film transistors, while the second gate layer GT2, the second gate insulating layer GI2, the metal oxide semiconductor layer OSCL, the third gate insulating layer GI3, and the third gate layer GT3 can form metal oxide thin-film transistors. Thus, this light-emitting substrate PNL is a display panel employing LTPO technology.

[0071] In this embodiment, the wiring unit layer furthest from the substrate SBT can be referred to as the top wiring unit layer; the source / drain metal layer SD in this wiring unit layer is the top source / drain metal layer TSD, which is the source / drain metal layer SD furthest from the substrate SBT; the planarization layer PLN in this wiring unit layer is the top planarization layer TPLN, which is the planarization layer PLN furthest from the substrate SBT. The top planarization layer TPLN can form vias exposing at least a portion of the top source / drain metal layer TSD, so that the light-emitting element LD in the pixel layer PXL is electrically connected to the top source / drain metal layer TSD, thereby enabling the pixel driving circuit PDC to be electrically connected to the sub-pixel PX.

[0072] Figure 3 The example light-emitting substrate PNL uses LTPO technology to drive the sub-pixel PX, and includes a stacked transistor layer TFTL and a wiring layer MRL. It is understood that in other embodiments of this disclosure, the driving layer DRL may also employ other driving techniques, such as passive driving techniques (e.g., the driving layer DRL may only have a wiring layer MRL and not a transistor layer TFTL) to drive the sub-pixel PX.

[0073] See Figure 3 In pixel layer PXL, sub-pixels PX are thin-film light-emitting elements, which may include two stacked electrodes and a light-emitting functional unit (EFU) sandwiched between the two electrodes. Figure 3In the example, the pixel layer PXL may include a pixel electrode layer PEL, a light-emitting functional layer EFL, and a common electrode layer COML stacked sequentially. The pixel electrode layer PEL has multiple pixel electrodes PE in the display area of ​​the light-emitting substrate PNL, and the pixel electrodes PE are directly or indirectly electrically connected to the top source drain metal layer TSD. The light-emitting functional layer EFL is in direct contact with at least a portion of the pixel electrodes PE, and the common electrode layer COML covers the light-emitting functional layer EFL. The portion of the light-emitting functional layer EFL in direct contact with the pixel electrodes PE serves as the light-emitting functional unit EFU of the sub-pixel PX. The pixel electrodes PE, the light-emitting functional unit EFU, and the common electrode layer COML form the light-emitting element LD of the sub-pixel PX. The pixel electrodes PE and the common electrode layer COML can provide electrons, holes, and other charge carriers to the light-emitting functional unit EFU, causing the light-emitting functional unit EFU to emit light. One of the pixel electrodes PE and the common electrode layer COML serves as the anode of the sub-pixel PX, and the other serves as the cathode of the sub-pixel PX. In this embodiment of the disclosure, the pixel electrode PE can be in contact with the light-emitting functional layer EFL in its entirety, or only in a portion of its area.

[0074] In one example, the sub-pixel PX is an organic light-emitting diode (OLED). It is understood that in other embodiments of this disclosure, the sub-pixel may also be other types of light-emitting elements, such as current-driven light-emitting elements like QLEDs and PLEDs. When the type of sub-pixel PX differs, the light-emitting functional layer (EFL) of the sub-pixel PX may also differ.

[0075] In one example, the sub-pixel PX is a top-emitting light-emitting element, the common electrode layer COML can be a transparent electrode, and the pixel electrode PE is a reflective electrode. When the sub-pixel PX emits light, it emits light from the side of the common electrode layer COML. In another example, the pixel electrode PE serves as the anode of the sub-pixel PX, and the common electrode layer COML serves as the cathode of the sub-pixel PX.

[0076] In one embodiment of this disclosure, see Figure 3The light-emitting substrate PNL may further include a thin-film encapsulation layer TFE located on the side of the pixel layer PXL away from the substrate SBT. This thin-film encapsulation layer TFE may include alternately stacked inorganic and organic encapsulation layers. The inorganic encapsulation layer effectively blocks external moisture and oxygen, preventing water and oxygen from invading the pixel layer PXL and causing material aging. Optionally, the edge of the inorganic encapsulation layer may be located in the peripheral region. The organic encapsulation layer is located between two adjacent inorganic encapsulation layers to achieve planarization and reduce stress between the inorganic encapsulation layers. The edge of the organic encapsulation layer may be located between the edge of the display area and the edge of the inorganic encapsulation layer. Exemplarily, the thin-film encapsulation layer TFE includes a first inorganic encapsulation layer, an organic encapsulation layer, and a second inorganic encapsulation layer sequentially stacked on the side of the pixel layer PXL away from the substrate SBT. Of course, in other embodiments of this disclosure, the thin-film encapsulation layer TFE may also employ other structures, such as multiple stacked inorganic encapsulation layers.

[0077] exist Figure 3 In the example, the light-emitting substrate PNL may also include a touch function layer TSL, which may be disposed on the side of the thin-film encapsulation layer TFE away from the pixel layer PXL, so that the light-emitting substrate PNL has touch functionality. Figure 3 In the example, the touch functional layer TSL includes a first touch metal layer, a touch insulating layer, and a second touch metal layer that are sequentially stacked on the surface of the thin film encapsulation layer TFE.

[0078] Understandably, the light-emitting substrate PNL can be configured with more layers or structures as needed, such as polarizers, color filters, or protective layers.

[0079] exist Figure 2 and Figure 3 In the example, the light-emitting substrate PNL is a display panel driven by a pixel drive circuit (PDC) formed using thin-film transistors. It is understood that in other embodiments of this disclosure, the light-emitting substrate PNL can be a silicon-based display panel driven by a silicon-based drive substrate.

[0080] For thin-film light-emitting diodes (LDs), their lifespan directly restricts their wider application and better user experience. In this disclosure, the LDs are arranged in a stacked structure, and the materials and film dimensions of the stacked LDs are specifically optimized to improve their efficiency and lifespan.

[0081] Figure 4 This is a schematic diagram of a stacked light-emitting element (LD) according to one embodiment of this disclosure. See also... Figure 4The light-emitting functional unit (EFU) of a stacked light-emitting element (LD) includes multiple stacked structural layers arranged between an anode (AE) and a cathode (CE), with a charge-generating layer (CGL) between adjacent stacked structural layers. Each stacked structural layer has a light-emitting layer for emitting light.

[0082] For example, in Figure 4 In the example, the light-emitting element LD has a first stacked structure layer ELS1, a charge generation layer CGL, and a second stacked structure layer ELS2 stacked sequentially between the anode AE ​​and the cathode CE. The first stacked structure layer ELS1 has a first light-emitting layer EL1 for emitting light, and the second stacked structure layer ELS2 has a second light-emitting layer EL2 for emitting light.

[0083] In embodiments of this disclosure, the type of light-emitting element (LD) can vary depending on the type of LD. For example, when the LD is an OLED, the light-emitting layer in the stacked structure is an organic light-emitting layer. As another example, when the LD is a QLED, the light-emitting layer in the stacked structure is a quantum dot light-emitting layer. For instance, in... Figure 5 In the example, a first organic light-emitting layer EML1 is disposed in the first stacked structure layer ELS1, and a second organic light-emitting layer EML2 is disposed in the second stacked structure layer ELS2. Figure 5 The LD shown in the example is a stacked OLED.

[0084] See Figure 4Each stacked structure layer includes a hole transport region, an emissive layer, and an electron transport region sequentially stacked along the direction from the anode (AE) to the cathode (CE). The hole transport region is used to inject holes into the emissive layer, and the electron transport region is used to inject electrons into the emissive layer. Electrons and holes recombine in the emissive layer to form excitons, thereby causing the emissive layer to emit light. The hole transport region and the electron transport region are used to adjust the injection efficiency and injection rate of holes and electrons injected into the emissive layer, as well as to adjust the energy levels of the injected electrons and holes, thereby improving the balance between hole injection and electron injection and thus improving the performance of the light-emitting functional unit (EFU), such as improving the luminous efficiency of the light-emitting element (LD), increasing the device lifetime of the LD, and reducing the power supply voltage of the LD, or one or more of these improvements. Optionally, the hole transport region may include one or more of the following films: a hole injection layer, a hole transport layer, and an electron blocking layer (or light-emitting auxiliary layer), which are sequentially stacked along the direction from the anode (AE) to the cathode (CE). Any one of these films can be a composite layer of multiple sub-films as needed. For example, the hole transport layer can be a hole transport layer made of a single material, or it can be a hole transport layer composed of stacked sub-films made of multiple different materials. Optionally, the electron transport region may include one or more of the following films: an electron injection layer, an electron transport layer, and a hole blocking layer, which are sequentially stacked along the direction from the cathode (CE) to the anode (AE). Any one of these films can be a composite layer of multiple sub-films as needed.

[0085] For example, in Figure 4 In the example, the first stacked structure layer ELS1 includes a first hole transport region HTA1, a first light-emitting layer EL1, and a first electron transport region ETA1 stacked sequentially along the direction from the anode AE ​​to the cathode CE. The first hole transport region HTA1 includes a hole injection layer HIL, a first hole transport layer HTL1, and a first electron blocking layer EBL1 stacked on the surface of the anode AE. The first electron transport region ETA1 includes a first hole blocking layer HBL1 and a first electron transport layer ETL1 stacked on the surface of the first light-emitting layer EL1.

[0086] For another example, in Figure 4 In the example, the second stacked structure layer ELS2 includes a second hole transport region HTA2, a second light-emitting layer EL2, and a second electron transport region ETA2 stacked sequentially along the direction from the anode AE ​​to the cathode CE. The second hole transport region HTA2 includes a second hole transport layer HTL2 and a second electron blocking layer EBL2 stacked on the surface of the charge generation layer CGL. The second electron transport region ETA2 includes a second hole blocking layer HBL2, a second electron transport layer ETL2, and an electron injection layer EIL stacked on the surface of the second light-emitting layer EL2.

[0087] See Figure 4The light-emitting functional unit (EFU) may also include a charge generation layer (CGL) located between two adjacent stacked structural layers to improve the efficiency of injecting electrons and holes into the two adjacent stacked structural layers. For example, the charge generation layer CGL includes an N-type charge generation layer (NCGL) and a P-type charge generation layer (PCGL) stacked between two adjacent stacked structural layers; wherein the N-type charge generation layer (NCGL) is adjacent to the electron transport region of one of the stacked structural layers for injecting electrons into that electron transport region; the P-type charge generation layer (PCGL) is adjacent to the hole transport region of the other stacked structural layer for injecting holes into that hole transport region. In other words, the P-type charge generation layer (PCGL) is located on the side of the N-type charge generation layer (NCGL) away from the anode (AE). Of course, it is understood that in other examples, the charge generation layer CGL may also include other structures.

[0088] In this embodiment of the disclosure, the light-emitting element LD further includes a light extraction layer CPL located on the side of the cathode CE away from the anode AE, so as to improve the light extraction efficiency of the light-emitting element LD.

[0089] In this embodiment, the materials of the charge generation layer CGL, the light extraction layer CPL, and the thickness of each film layer can achieve a synergistic effect, ultimately improving the light extraction efficiency of the light-emitting element LD. Below, the adjustment of each film layer of the light-emitting element LD, the selection of the material for the charge generation layer CGL, and the selection of the material for the light extraction layer CPL will be explained one by one. Then, verification of the synergistic effect of these three factors improving the light extraction efficiency of the light-emitting substrate PNL will be presented.

[0090] In this embodiment of the disclosure, for ease of description, when describing the upper surface of a certain film layer (excluding the anode AE) of the light-emitting element LD, it refers to the surface of the film layer away from the anode AE; when describing the lower surface of a certain film layer (excluding the anode AE) of the light-emitting element LD, it refers to the surface of the film layer close to the anode AE. The upper surface of the anode AE ​​is the surface of the anode AE ​​close to the cathode CE, and the lower surface of the anode AE ​​refers to the surface of the anode AE ​​away from the cathode CE.

[0091] In one example, the cathode CE is a transparent electrode, and the light-emitting element LD emits light from the cathode CE side.

[0092] See Figure 4In the light-emitting element (LD) of this embodiment, the thickness of the second electron transport region ETA2 is a first dimension L1, that is, the distance between the lower surface of the cathode CE and the upper surface of the second light-emitting layer EL2 is a first dimension L1. The thickness of the first hole transport region HTA1 is a second dimension L2, that is, the distance between the lower surface of the first light-emitting layer EL1 and the upper surface of the anode AE ​​is a second dimension L2. The distance between the second electron transport region ETA2 and the first hole transport layer HTL1 is a third dimension L3, that is, the distance between the lower surface of the second electron transport region ETA2 and the upper surface of the first hole transport layer HTL1 is a third dimension L3. The total thickness of the first electron blocking layer EBL1 and the first light-emitting layer EL1 is a fourth dimension L4, that is, the distance between the upper surface of the first light-emitting layer EL1 and the lower surface of the first electron blocking layer EBL1 is a fourth dimension L4. The total thickness of the second electron blocking layer EBL2 and the second light-emitting layer EL2 is a fifth dimension L5, that is, the distance between the upper surface of the second light-emitting layer EL2 and the lower surface of the second electron blocking layer EBL2 is a fifth dimension L5. In this embodiment of the present disclosure, the first dimension L1 to the fifth dimension L5 can be adjusted so that the first light-emitting layer EL1 and the second light-emitting layer EL2 are located in the microcavity reinforcement region, thereby improving the light emission efficiency of the first light-emitting layer EL1 and the second light-emitting layer EL2.

[0093] In one embodiment of this disclosure, a red light-emitting element (RLD), a green light-emitting element (GLD), and a blue light-emitting element (BLD) can be simultaneously disposed on a light-emitting substrate (PNL). The materials and thicknesses of certain film layers of the red light-emitting element (RLD), the green light-emitting element (GLD), and the blue light-emitting element (BLD) can be different to achieve simultaneous optimization of the red light-emitting element (RLD), the blue light-emitting element (BLD), and the green light-emitting element (GLD).

[0094] exist Figure 6 In the example, L1(R) represents the first dimension L1 of the red light-emitting element RLD; L2(R) represents the second dimension L2 of the red light-emitting element RLD; L3(R) represents the third dimension L3 of the red light-emitting element RLD; L4(R) represents the fourth dimension L4 of the red light-emitting element RLD; L5(R) represents the fifth dimension L5 of the red light-emitting element RLD; and L(R) represents the total thickness L of the red light-emitting element RLD. Figure 7 In the example, L1(G) represents the first dimension L1 of the green light-emitting element GLD; L2(G) represents the second dimension L2 of the green light-emitting element GLD; L3(G) represents the third dimension L3 of the green light-emitting element GLD; L4(G) represents the fourth dimension L4 of the green light-emitting element GLD; L5(G) represents the fifth dimension L5 of the green light-emitting element GLD; and L(G) represents the total thickness L of the green light-emitting element GLD. Figure 8In the example, L1(B) represents the first dimension L1 of the blue light-emitting element BLD; L2(B) represents the second dimension L2 of the blue light-emitting element BLD; L3(B) represents the third dimension L3 of the blue light-emitting element BLD; L4(B) represents the fourth dimension L4 of the blue light-emitting element BLD; L5(B) represents the fifth dimension L5 of the blue light-emitting element BLD; and L(B) represents the total thickness L of the blue light-emitting element BLD.

[0095] Optionally, the first dimensions L1(R) of the red light-emitting element, L1(B) of the blue light-emitting element, and L1(G) of the green light-emitting element can be the same or different.

[0096] In one example, the second hole-blocking layer HBL2, the second electron transport layer ETL2, and the electron injection layer EIL are all common layers; that is, the red light-emitting element (RLD), the blue light-emitting element (BLD), and the green light-emitting element (GLD) share the second hole-blocking layer HBL2, the second electron transport layer ETL2, and the electron injection layer EIL. For example, an open-face mask can be used to fabricate the second hole-blocking layer HBL2, the second electron transport layer ETL2, and the electron injection layer EIL. In this way, the first dimension L1(R), the first dimension L1(B), and the first dimension L1(G) of the red light-emitting element are the same.

[0097] Optionally, the second dimensions L2(R) of the red light-emitting element, L2(B) of the blue light-emitting element, and L2(G) of the green light-emitting element can be the same or different.

[0098] In one example, the hole injection layer HIL is a common layer, that is, the red light-emitting element RLD, the blue light-emitting element BLD, and the green light-emitting element GLD share the hole injection layer HIL. For example, an open mask can be used to prepare the hole injection layer HIL.

[0099] In one example, the first hole transport layer HTL1 is a common layer, that is, the red light-emitting element RLD, the blue light-emitting element BLD and the green light-emitting element GLD share the first hole transport layer HTL1. For example, an open mask can be used to prepare the first hole transport layer HTL1.

[0100] In one example, the materials or thicknesses of the first electron blocking layers EBL1 of the red light-emitting element (RLD), blue light-emitting element (BLD), and green light-emitting element (GLD) can differ. For example, the materials of the first electron blocking layers EBL1R, EBL1G, and EBL1B of the red light-emitting element, green light-emitting element, and blue light-emitting element can be different to match the energy levels of the first electron blocking layers EBL1 with the energy levels of the first light-emitting layer EL1. As another example, the thicknesses of the first electron blocking layers EBL1R, EBL1G, and EBL1B of the red, green, and blue light-emitting elements can be different to adjust the second dimensions L2(R), L2(B), and L2(G) of the red, blue, and green light-emitting elements, respectively, so that the first red light-emitting layer REL1, the first green light-emitting layer GEL1, and the first blue light-emitting layer BEL1 are each located in the microcavity reinforcement region. In this example, a precision metal mask can be used to deposit the first electron blocking layer EBL1 and the first emitting layer EL1 of the light-emitting element (LD). For example, a first precision metal mask can be used to deposit the first electron blocking layer EBL1R and the first red emitting layer REL1 of the red light-emitting element, a second precision metal mask can be used to deposit the first electron blocking layer EBL1G and the first green emitting layer GEL1 of the green light-emitting element, and a third precision metal mask can be used to deposit the first electron blocking layer EBL1B and the first blue emitting layer BEL1 of the blue light-emitting element. Accordingly, the fourth dimension L4(R) of the red light-emitting element, the fourth dimension L4(B) of the blue light-emitting element, and the fourth dimension L4(G) of the green light-emitting element can be different.

[0101] Optionally, the third dimension L3(R) of the red light-emitting element, the third dimension L3(B) of the blue light-emitting element, and the third dimension L3(G) of the green light-emitting element can be the same or different.

[0102] In one example, the first hole blocking layer HBL1 is a common layer, that is, the red light-emitting element RLD, the blue light-emitting element BLD and the green light-emitting element GLD share the first hole blocking layer HBL1. For example, an open mask can be used to prepare the first hole blocking layer HBL1.

[0103] In one example, the first electron transport layer ETL1 is a common layer, meaning that the red light-emitting element (RLD), the blue light-emitting element (BLD), and the green light-emitting element (GLD) share the first electron transport layer ETL1. For example, an open-mask can be used to fabricate the first electron transport layer ETL1. In other examples of this disclosure, for example in... Figure 9 In the example, the light-emitting element LD may also omit the first electron transport layer ETL1.

[0104] In one example, the N-type charge generation layer NCGL is a common layer, that is, the red light-emitting element RLD, the blue light-emitting element BLD and the green light-emitting element GLD share the N-type charge generation layer NCGL. For example, an open mask can be used to prepare the N-type charge generation layer NCGL.

[0105] In one example, the P-type charge generation layer PCGL is a common layer, that is, the red light-emitting element RLD, the blue light-emitting element BLD and the green light-emitting element GLD share the P-type charge generation layer PCGL. For example, an open mask can be used to prepare the P-type charge generation layer PCGL.

[0106] In one example, the second hole transport layer HTL2 is a common layer, that is, the red light-emitting element RLD, the blue light-emitting element BLD and the green light-emitting element GLD share the second hole transport layer HTL2. For example, an open mask can be used to prepare the second hole transport layer HTL2.

[0107] In one example, the materials or thicknesses of the second electron blocking layers EBL2 of the red light-emitting element (RLD), blue light-emitting element (BLD), and green light-emitting element (GLD) can differ. For example, the materials of the second electron blocking layers EBL2R, EBL2G, and EBL2B of the red light-emitting element, green light-emitting element, and blue light-emitting element can be different to match the energy levels of the second electron blocking layers EBL2 with the energy levels of the second light-emitting layer EL2. As another example, the thicknesses of the second electron blocking layers EBL2R, EBL2G, and EBL2B of the red, green, and blue light-emitting elements can be different to ensure that the second red light-emitting layer REL2, second green light-emitting layer GEL2, and second blue light-emitting layer BEL2 are each located in the microcavity reinforcement region. In this example, a precision metal mask can be used to deposit the second electron blocking layer EBL2 and the second light-emitting layer EL2 of the light-emitting element LD. For example, a fourth precision metal mask is used to deposit the second electron blocking layer EBL2R and the second red emitting layer REL2 for the red light-emitting element; a fifth precision metal mask is used to deposit the second electron blocking layer EBL2G and the second green emitting layer GEL2 for the green light-emitting element; and a sixth precision metal mask is used to deposit the second electron blocking layer EBL2B and the second blue emitting layer BEL2 for the blue light-emitting element. Correspondingly, the fifth dimension L5(R) of the red light-emitting element, the fifth dimension L5(B) of the blue light-emitting element, and the fifth dimension L5(G) of the green light-emitting element can be different, and the third dimension L3(R) of the red light-emitting element, the third dimension L3(B) of the blue light-emitting element, and the third dimension L3(G) of the green light-emitting element can also be different.

[0108] In one embodiment of this disclosure, 0.1 ≤ L2 / L3 ≤ 0.45; 0.5 ≤ L3 / L ≤ 0.9. This allows the first emitting layer EL1 and the second emitting layer EL2 to each be located in the light-enhancing region of the microcavity.

[0109] In one embodiment of this disclosure, in the red light-emitting element RLD, 0.1 ≤ L2(R) / L3(R) ≤ 0.3, and particularly 0.15 ≤ L2(R) / L3(R) ≤ 0.25. For example, the value of L2(R) / L3(R) is 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, 0.21, 0.22, 0.23, 0.24, or 0.25. This allows the first red light-emitting layer REL1 of the red light-emitting element RLD to be located in or near the 1 / 4 red light wavelength region, which is beneficial for improving the light extraction efficiency of the red light emitted by the first red light-emitting layer REL1 through the microcavity effect.

[0110] In one embodiment of this disclosure, in the green light-emitting element GLD, 0.15 ≤ L2(G) / L3(G) ≤ 0.35, and particularly 0.2 ≤ L2(G) / L3(G) ≤ 0.3. For example, the value of L2(G) / L3(G) is 0.2, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.3. This allows the first green light-emitting layer GEL1 of the green light-emitting element GLD to be located in or near the 1 / 4 green light wavelength region, which is beneficial for improving the light extraction efficiency of the green light emitted by the first green light-emitting layer GEL1 through the microcavity effect.

[0111] In one embodiment of this disclosure, in the blue light-emitting element (BLD), 0.25 ≤ L2(B) / L3(B) ≤ 0.45, and particularly 0.3 ≤ L2(B) / L3(B) ≤ 0.4. For example, the value of L2(B) / L3(B) is 0.3, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, or 0.4. This allows the first blue light-emitting layer (BEL1) of the blue light-emitting element (BLD) to be located in or near the 1 / 4 blue light wavelength region, which is beneficial for improving the light extraction efficiency of the blue light emitted by the first blue light-emitting layer (BEL1) through the microcavity effect.

[0112] In one embodiment of this disclosure, in the red light-emitting element RLD,

[0113] 0.65 ≤ L3(R) / L(R) ≤ 0.9, especially 0.7 ≤ L3(R) / L(R) ≤ 0.8. For example, the value of L3(R) / L(R) can be 0.7, 0.71, 0.72, 0.73, 0.74, 0.75, 0.76, 0.77, 0.78, 0.79, or 0.8. In this way, the second red emitting layer REL2 of the red light-emitting element RLD can be located in or close to the 3 / 4 red light wavelength region, which is beneficial to improving the light extraction efficiency of the red light emitted by the second red emitting layer REL2 through the microcavity effect.

[0114] In one embodiment of this disclosure, in a green light-emitting element (GLD),

[0115] 0.6 ≤ L3(G) / L(G) ≤ 0.85, especially 0.65 ≤ L3(G) / L(G) ≤ 0.75. For example, the value of L3(G) / L(G) is 0.65, 0.66, 0.67, 0.68, 0.69, 0.7, 0.71, 0.72, 0.73, 0.74, or 0.75. In this way, the second green emitting layer GEL2 of the green light-emitting element GLD can be located in or close to the 3 / 4 green light wavelength region, which is beneficial to improving the light extraction efficiency of the green light emitted by the second green emitting layer GEL2 through the microcavity effect.

[0116] In one embodiment of this disclosure, in the blue light-emitting element (BLD),

[0117] 0.5 ≤ L3(B) / L(B) ≤ 0.8, especially 0.6 ≤ L3(B) / L(B) ≤ 0.7. For example, the value of L3(B) / L(B) can be 0.6, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, 0.69, or 0.7. In this way, the second blue emitting layer BEL2 of the blue light-emitting element BLD can be located in or close to the 3 / 4 blue light wavelength region, which is beneficial to improving the light extraction efficiency of the blue light emitted by the second blue emitting layer BEL2 through the microcavity effect.

[0118] In one embodiment of this disclosure, the first electron blocking layer EBL1 and the second electron blocking layer EBL2 of the light-emitting element LD can be made of the same material, and the first light-emitting layer EL1 and the second light-emitting layer EL2 can also be made of the same material. Thus, the exciton recombination region of the first stacked structure layer ELS1 is the same as or similar to the exciton recombination region of the second stacked structure layer ELS2, which can effectively suppress color separation problems.

[0119] For example, the first electron blocking layer EBL1R and the second electron blocking layer EBL2R of the red light-emitting element are made of the same material, and the first red light-emitting layer REL1 and the second red light-emitting layer REL2 are made of the same material. Thus, the exciton recombination region of the first red stacked structure layer RELS1 is essentially the same as the exciton recombination region of the second red stacked structure layer RELS2, which can effectively suppress the color separation problem of the red light-emitting element RLD.

[0120] For example, the first electron blocking layer EBL1G and the second electron blocking layer EBL2G of the green light-emitting element are made of the same material, and the first green light-emitting layer GEL1 and the second green light-emitting layer GEL2 are made of the same material. In this way, the exciton recombination region of the first green stacked structure layer GELS1 is basically the same as that of the second green stacked structure layer GELS2, which can effectively suppress the color separation problem of the green light-emitting element GLD.

[0121] For example, the first electron blocking layer EBL1B and the second electron blocking layer EBL2B of the blue light-emitting element are made of the same material, and the first blue light-emitting layer BEL1 and the second blue light-emitting layer BEL2 are made of the same material. Thus, the exciton recombination region of the first blue stacked structure layer BELS1 is essentially the same as the exciton recombination region of the second blue stacked structure layer BELS2, which can effectively suppress the color separation problem of the blue light-emitting element (BLD).

[0122] In one embodiment of this disclosure, the first electron blocking layer EBL1 and the second electron blocking layer EBL2 of the light-emitting element LD have the same or similar thicknesses, and the first light-emitting layer EL1 and the second light-emitting layer EL2 have the same or similar thicknesses. Thus, the exciton recombination region of the first stacked structure layer ELS1 and the exciton recombination region (electron blocking layer + light-emitting layer) of the second stacked structure layer ELS2 have the same or similar thicknesses, which can improve the uniformity of the luminous efficiency of the first stacked structure layer ELS1 and the second stacked structure layer ELS2, thereby helping to suppress color separation. In one example, 0.8 ≤ L4 / L5 ≤ 1.2, especially 0.9 ≤ L4 / L5 ≤ 1.1.

[0123] For example, 0.8 ≤ L4(R) / L5(R) ≤ 1.2, such as L4(R) / L5(R) values ​​of 0.9, 0.92, 0.94, 0.96, 0.98, 1, 1.02, 1.04, 1.06, 1.08, or 1.1. In one example, the thickness ratio of the first electron blocking layer EBL1R to the second electron blocking layer EBL2R of the red light-emitting element is in the range of 0.9 to 1.1. In another example, the thickness ratio of the first red light-emitting layer REL1 to the second red light-emitting layer REL2 is in the range of 0.9 to 1.1. This further improves the similarity of the exciton recombination regions of the first red stacked structure layer RELS1 and the second red stacked structure layer RELS2, further reducing the risk of color separation in the red light-emitting element RLD.

[0124] For example, 0.8 ≤ L4(G) / L5(G) ≤ 1.2, such as L4(G) / L5(G) values ​​of 0.9, 0.92, 0.94, 0.96, 0.98, 1, 1.02, 1.04, 1.06, 1.08, or 1.1. In one example, the thickness ratio of the first electron blocking layer EBL1G to the second electron blocking layer EBL2G of the green light-emitting element is in the range of 0.9 to 1.1. In another example, the thickness ratio of the first green light-emitting layer GEL1 to the second green light-emitting layer GEL2 is in the range of 0.9 to 1.1. This further improves the similarity of the exciton recombination regions of the first green stacked structure layer GELS1 and the second green stacked structure layer GELS2, further reducing the risk of color separation in the green light-emitting element (GLD).

[0125] For example, 0.8 ≤ L4(B) / L5(B) ≤ 1.2, such as L4(B) / L5(B) values ​​of 0.9, 0.92, 0.94, 0.96, 0.98, 1, 1.02, 1.04, 1.06, 1.08, or 1.1. In one example, the thickness ratio of the first electron blocking layer EBL1B to the second electron blocking layer EBL2B of the blue light-emitting element is in the range of 0.9 to 1.1, and the thickness ratio of the first blue light-emitting layer BEL1 to the second blue light-emitting layer BEL2 is in the range of 0.9 to 1.1. This further improves the similarity of the exciton recombination regions of the first blue stacked structure layer BELS1 and the second blue stacked structure layer BELS2, further reducing the risk of color separation in the blue light-emitting element (BLD).

[0126] In one embodiment of this disclosure, the thickness of the first hole transport region HTA1 is not significantly different from the thickness of the second electron transport region ETA2, for example, 0.8 ≤ L1 / L2 ≤ 1.25. This facilitates the adjustment of electron and hole injection efficiency and injection balance, and also facilitates the adjustment of the positions of the first light-emitting layer EL1 and the second light-emitting layer EL2, ensuring that both the first light-emitting layer EL1 and the second light-emitting layer EL2 are in a position of enhanced light emission.

[0127] For example, 0.8≤L1(R) / L2(R)≤1.2; this is beneficial for adjusting the positions of the first red light-emitting layer REL1 and the second red light-emitting layer REL2 in the red light-emitting element RLD.

[0128] For example, 0.85≤L1(G) / L2(G)≤1.25; this is beneficial for adjusting the position of the first green light-emitting layer GEL1 and the second green light-emitting layer GEL2 in the green light-emitting element GLD.

[0129] For example, 0.8≤L1(B) / L2(B)≤1.25; this is beneficial for adjusting the position of the first blue light-emitting layer BEL1 and the second blue light-emitting layer BEL2 in the blue light-emitting element BLD.

[0130] In one embodiment of this disclosure, the thicknesses of the red light-emitting element (RLD), the green light-emitting element (GLD), and the blue light-emitting element (BLD) can be optimized to facilitate light emission from the light-emitting elements (LDs). For example, the first light-emitting layer (EL1) and the second light-emitting layer (EL2) can both be located in the light emission enhancement region.

[0131] In one example, the total thickness L(R) of the red light-emitting element is ≤250nm ≤ 300nm, meaning the total thickness of the light-emitting functional unit (EFU) of the red light-emitting element (RLD) is between 250nm and 300nm. For example, the total thickness of the EFU of the red light-emitting element (RLD) can be 250nm, 255nm, 260nm, 265nm, 270nm, 275nm, 280nm, 285nm, 290nm, 295nm, or 300nm. This allows the first red light-emitting layer (REL1) and the second red light-emitting layer (REL2) to be located in or near the 1 / 4 and 3 / 4 red light wavelength regions of the red light-emitting element (RLD), respectively.

[0132] In one example, the total thickness L(G) of the green light-emitting element is ≤200nm ≤250nm, meaning the total thickness of the light-emitting functional unit (EFU) of the green light-emitting element (GLD) is between 200nm and 250nm. For example, the total thickness of the EFU of the green light-emitting element (GLD) can be 200nm, 205nm, 210nm, 215nm, 220nm, 225nm, 230nm, 235nm, 240nm, 245nm, or 250nm. This allows the first green light-emitting layer GEL1 and the second green light-emitting layer GEL2 to be located in or near the 1 / 4 and 3 / 4 green light wavelength regions of the green light-emitting element (GLD), respectively.

[0133] In one example, 150nm ≤ total thickness L(B) of the blue light-emitting element ≤ 200nm, meaning the total thickness of the light-emitting functional unit (EFU) of the blue light-emitting element (BLD) is between 150 and 200nm. For example, the total thickness of the EFU of the blue light-emitting element (BLD) can be 150nm, 155nm, 160nm, 165nm, 170nm, 175nm, 180nm, 185nm, 190nm, 195nm, or 200nm. This allows the first blue light-emitting layer (BEL1) and the second blue light-emitting layer (BEL2) to be located in or near the 1 / 4 and 3 / 4 blue light wavelength regions of the blue light-emitting element (BLD), respectively.

[0134] In one embodiment of this disclosure, Wherein, n(460) is the refractive index of the light extraction layer CPL for light with a wavelength of 460nm; n(530) is the refractive index of the light extraction layer CPL for light with a wavelength of 530nm; and n(620) is the refractive index of the light extraction layer CPL for light with a wavelength of 620nm.

[0135] In one embodiment of this disclosure, k1(405)-k1(430)≥0.1. Wherein, k1(405) is the extinction coefficient of the light extraction layer CPL for light with a wavelength of 405nm; k1(430) is the extinction coefficient of the light extraction layer CPL for light with a wavelength of 430nm.

[0136] In one embodiment of this disclosure, the extinction coefficient of the light extraction layer CPL for light with a wavelength of 430 nm or higher is no greater than 0.08.

[0137] In one embodiment of this disclosure, the refractive index of the light extraction layer CPL gradually decreases with increasing wavelength, for example, n(460) > n(4530) > n(620).

[0138] Understandably, for blue light-emitting diodes (BLDs), increasing the thickness of the light extraction layer (CPL) helps improve light extraction efficiency. For red light-emitting diodes (RLDs) and green light-emitting diodes (GLDs), decreasing the thickness of the CPL helps improve light extraction efficiency. Therefore, selecting appropriate CPL materials and thicknesses helps maintain a balance in the extraction of red, green, and blue light, thereby improving white light efficiency.

[0139] In one embodiment of this disclosure, the material of the light extraction layer CPL has the following structural formula as described in the chemical formula.

[0140] As shown in Equation 1:

[0141]

[0142] Ar1, Ar2, and Ar3 are each independently selected from aryl groups with 6 to 60 substituted or unsubstituted carbon atoms, or heteroaryl groups with 5 to 60 substituted or unsubstituted carbon atoms, and at least one is selected from the structure shown in Formula 2.

[0143] L a L b Each is independently selected from arylene groups with 6 to 60 carbon atoms (single bond, substituted or unsubstituted) and heteroarylene groups with 2 to 60 carbon atoms (substituted or unsubstituted);

[0144] X is selected from O, S, C(R1R2) or NR3;

[0145] R1, R2, and R3 are each independently selected from alkyl groups with 1 to 10 carbon atoms, cycloalkyl groups with 5 to 10 carbon atoms, aryl groups with 6 to 20 carbon atoms, and heteroaryl groups with 5 to 20 carbon atoms.

[0146] In one embodiment of this disclosure, Ar1, Ar2, and Ar3 are each independently selected from the group consisting of the following structures:

[0147]

[0148] Furthermore, at least one of Ar1, Ar2, and Ar3 is selected from the group consisting of the following structures:

[0149]

[0150] In one embodiment of this disclosure, the material of the light extraction layer CPL is selected from the group consisting of the following compounds:

[0151]

[0152]

[0153]

[0154] The aromatic amine compounds provided above for use in the optical extraction layer CPL employ an aromatic amine as the main core, with conjugated systems containing heteroatoms such as N, O, or S linked to the core group. The conjugated system increases the polarizability of the compound, and the presence of heteroatoms further enhances the polarizability, thereby increasing the overall refractive index of the aromatic amine compound, resulting in high polarizability and refractive index. Thus, when these compounds are applied to the optical extraction layer CPL, they can effectively improve the optical coupling efficiency of the light-emitting element, improve the light emission mode of the light-emitting element, and allow light inside the light-emitting element to exit the element more efficiently, effectively improving the light extraction efficiency of the electroluminescent device. Simultaneously, these compounds exhibit high stability, which can improve the stability of the optical extraction layer CPL itself, increase the thermal stability of the light-emitting element LD fabrication, and extend the lifespan of the light-emitting element LD. Furthermore, these materials used in the optical extraction layer CPL have a very low absorption coefficient in the visible light region but a high absorption coefficient in the ultraviolet light band. This reduces the absorption of visible light by the light extraction layer CPL and prevents high-energy light such as ultraviolet rays from entering the interior of the light-emitting element (LD) and accelerating the aging of the LD material. Therefore, the light extraction layer CPL can simultaneously extract visible light and protect the LD from ultraviolet light damage, thus improving both the light extraction efficiency and lifespan of the LD.

[0155] In the above compounds, compound 1-1 has a refractive index of 2.45 at 460 nm, 2.18 at 530 nm, and 2.03 at 620 nm. Compound 1-2 has a refractive index of 2.23 at 460 nm, 2.09 at 530 nm, and 2.02 at 620 nm. In contrast, compound CPL-Ref, a commonly used light extraction layer material, has a refractive index of 2.16 at 460 nm, 2.01 at 530 nm, and 1.96 at 620 nm. This indicates that the light extraction layer CPL provided in this embodiment not only has a larger refractive index.

[0156]

[0157] In the light-emitting element (LD) provided in this disclosure, a charge generation layer CGL is located between a first stacked structural layer ELS1 and a second stacked structural layer ELS2, used to inject electrons into the first stacked structural layer ELS1 and holes into the second stacked structural layer ELS2. The charge generation layer CGL needs to efficiently generate, transport, and inject charge. Furthermore, the charge generation layer CGL also needs to have high light transmittance. This disclosure provides a material combination of an N-type charge generation layer NCGL and a P-type charge generation layer PCGL to enable the charge generation layer CGL to efficiently generate, transport, and inject charge, thereby improving the light extraction efficiency of the light-emitting element LD.

[0158] In one embodiment of this disclosure, the N-type charge generation layer NCGL may include a host material and a doped material to provide electron injection efficiency and stability.

[0159] In one example, the mass ratio of the doped material in the N-type charge generation layer NCGL is 0.5% to 11%, for example, 0.5%, 1.5%, 2.5%, 3.5%, 4.5%, 5.5%, 6.5%, 7.5%, 8.5%, 9.5%, 10.5%, or 11%.

[0160] In one example, the doping material in the N-type charge generation layer NCGL comprises at least one alkali metal, alkaline earth metal, or transition metal, or a compound of alkali metal, alkaline earth metal, or transition metal. For example, the doping material in the N-type charge generation layer NCGL can be an alkali metal, a lanthanide metal, or Liq (lithium isoquinoline).

[0161] In one example, the glass transition temperature of the host material of the N-type charge generation layer NCGL is greater than 120°C.

[0162] In one example, the host material of the N-type charge generation layer NCGL contains multiple heteroatoms. When the host material of the N-type charge generation layer NCGL is entirely composed of nitrogen atoms, SP 2 The number of hybridized nitrogen atoms is no less than two.

[0163] In one embodiment of this disclosure, the structural formula of the host material of the N-type charge generation layer NCGL is shown in Chemical Formula 3:

[0164]

[0165] Among them, X1, X2, X3, and X4 are each independently selected from N or C(R4), and at least two of X1, X2, X3, and X4 are selected from N;

[0166] R4 may appear the same or different each time, and each is independently selected from hydrogen, deuterium, substituted or unsubstituted alkyl with 1 to 60 carbon atoms, substituted or unsubstituted alkenyl with 2 to 60 carbon atoms, substituted or unsubstituted alkynyl with 2 to 60 carbon atoms, substituted or unsubstituted alkoxy with 1 to 60 carbon atoms, substituted or unsubstituted cycloalkyl with 3 to 10 carbon atoms, substituted or unsubstituted heterocyclic alkyl with 1 to 10 carbon atoms, substituted or unsubstituted Cycloalkenyl groups with 3 to 10 carbon atoms, heterocyclic alkenyl groups with 1 to 10 substituted or unsubstituted carbon atoms, aryl groups with 6 to 60 substituted or unsubstituted carbon atoms, aryloxy groups with 6 to 60 substituted or unsubstituted carbon atoms, arylthio groups with 6 to 60 substituted or unsubstituted carbon atoms, heteroaryl groups with 1 to 60 substituted or unsubstituted carbon atoms, monovalent non-aromatic condensed polycyclic groups with substituted or unsubstituted carbon atoms, and monovalent non-aromatic condensed heteropolycyclic groups with substituted or unsubstituted carbon atoms;

[0167] Ar4, Ar5, Ar6, and Ar7 may be the same or different, and each is independently selected from the group consisting of: hydrogen, deuterium, tritium, halogen, cyano, nitro, aryl group with 6 to 60 substituted or unsubstituted carbon atoms, heterocyclic group with 2 to 60 substituted or unsubstituted carbon atoms containing at least one heteroatom from O, N, S, Si, and P, aliphatic ring with 3 to 60 substituted or unsubstituted carbon atoms, fused ring group of aromatic ring with 6 to 60 substituted or unsubstituted carbon atoms, and substituted or unsubstituted... Alkyl groups having 1 to 50 carbon atoms, alkenyl groups having 2 to 20 carbon atoms (substituted or unsubstituted), alkynyl groups having 2 to 20 carbon atoms (substituted or unsubstituted), alkoxy groups having 1 to 30 carbon atoms (substituted or unsubstituted), aryloxy groups having 6 to 30 carbon atoms (substituted or unsubstituted), alkylsilyl groups having 3 to 60 carbon atoms (substituted or unsubstituted), arylsilyl groups having 18 to 60 carbon atoms (substituted or unsubstituted), and alkylarylsilyl groups having 8 to 60 carbon atoms (substituted or unsubstituted).

[0168] The heterocyclic compound shown in Formula 3 possesses a low (deep) LUMO level, which lowers the energy barrier at the interface between the N-type charge generation layer (NCGL) and the P-type charge generation layer (PCGL), thereby suppressing interface degradation caused by carrier accumulation due to the energy level barrier. Doping in the N-type charge generation layer (NCGL) further lowers the LUMO level, further enhancing electron injection characteristics. When the dopant in the N-type charge generation layer (NCGL) is a metal, to overcome the problem of high metal activity and instability, the host material of the N-type charge generation layer (NCGL) possesses binding sites, enabling the metal to form stable complexes.

[0169] The heterocyclic compound shown in formula 3 has SP 2The hybrid N atoms give this type of compound excellent electron transport capabilities, enabling the electron flow generated by the (pin) structure formed in the P-type charge generation layer PCGL and the N-type charge generation layer NCGL to be rapidly transported to the first stacked structure layer ELS1 through the N-type charge generation layer NCGL, thereby facilitating the luminescence of the first stacked structure layer ELS1.

[0170] Meanwhile, the heterocyclic compound shown in Formula 3 has SP 2 Hybridized nitrogen atoms, with their lone pairs of electrons, can form complexes with active metal compounds in the N-type charge generation layer (NCGL). This suppresses crystallization of the host material and increases the electron injection capability of the NCGL. This allows for control of crystallization at the interface between the first electron transport region (ETA1) and the NCGL, resulting in a more uniform interface morphology. Consequently, charge flow in the light-emitting element (LD) can be improved, thereby reducing the driving voltage.

[0171] In one example, at least one of the Ar4, Ar5, Ar6, and Ar7 is selected from the group consisting of:

[0172]

[0173] Ar8, Ar9, Ar 10 Ar 11 Ar 12 Ar 13 Ar 14 Each is independently selected from phenyl, diphenyl, triphenyl, naphthyl, anthracene, phenanthryl, pyridyl, pyrimidinyl, quinolinyl, isoquinolinyl, or phenanthrolineyl;

[0174] L c L d L e L f Each is independently selected from single bonds, phenylene, diphenylene, terphenylene, naphthylene, anthraceneylene, phenanthrene, pyridylene, and pyrimidinyl.

[0175] In one example, at least one of the Ar4, Ar5, Ar6, and Ar7 is selected from the group consisting of:

[0176]

[0177] In one example, the host material of the N-type charge-generating layer NCGL is selected from the group consisting of the following compounds:

[0178]

[0179]

[0180] Compound 3-19.

[0181] In one embodiment of this disclosure, the P-type charge generation layer PCGL includes a host material and a dopant material to improve the hole injection efficiency of the P-type charge generation layer PCGL. Further, at least one of the host material and the dopant material is a compound containing a large stereostructure.

[0182] In one example, the mass ratio of the doped material in the P-type charge generation layer PCGL is 3% to 10%, for example, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10%.

[0183] In one embodiment of this disclosure, the structure of the doped material of the P-type charge generation layer PCGL is shown in Chemical Formula 4:

[0184]

[0185] Structural Formula 4

[0186] Among them, X5 and X6 are each independently selected from C(Rg), N, and Si(Rg);

[0187] Y1 and Y2 are each independently selected from N(Rh), O, and S;

[0188] Ra, Rb, Rc, Rd, Rg, and Rh are each independently selected from halogens, cyano groups, substituted or unsubstituted phenyl groups, substituted or unsubstituted biphenyl groups, substituted or unsubstituted terphenyl groups, substituted or unsubstituted fluorene groups, substituted or unsubstituted adamantane groups, and substituted or unsubstituted heteroaryl groups.

[0189] Re and Rf are each independently selected from deuterium, halogen groups, cyano, heteroaryl groups with 3 to 20 substituted or unsubstituted carbon atoms, aryl groups with 6 to 20 substituted or unsubstituted carbon atoms, alkyl groups with 1 to 5 substituted or unsubstituted carbon atoms, haloalkyl groups with 1 to 10 substituted or unsubstituted carbon atoms, cycloalkyl groups with 3 to 10 substituted or unsubstituted carbon atoms, heterocycloalkyl groups with 2 to 10 substituted or unsubstituted carbon atoms, alkoxy groups with 1 to 10 substituted or unsubstituted carbon atoms, alkylthio groups with 1 to 10 substituted or unsubstituted carbon atoms, aryloxy groups with 6 to 18 substituted or unsubstituted carbon atoms, arylthio groups with 6 to 18 carbon atoms, phosphoxy groups with 6 to 24 carbon atoms, and alkylsulfonyl groups with 6 to 18 substituted or unsubstituted carbon atoms.

[0190] a and b are independent integers from 1 to 5.

[0191] The compound shown in Formula 4 contains a large number of electron-withdrawing groups. As a dopant material for the P-type charge generation layer PCGL, this compound can be co-deposited with the host material of the P-type charge generation layer PCGL to form the P-type charge generation layer PCGL. This can improve the conductivity of the P-type charge generation layer PCGL, ensure charge transport in the P-type charge generation layer PCGL, and especially improve the hole injection characteristics of the P-type charge generation layer PCGL.

[0192] In one example, Ra, Rb, Rc, and Rd are each independently selected from cyano, fluorine-substituted phenyl, trifluoromethyl-substituted phenyl, and trifluoromethoxy-substituted phenyl; and at least one of Ra and Rb is cyano, and at least one of Rc and Rd is cyano.

[0193] In one example, Y1 and Y2 are each independently selected from O and S.

[0194] In one example, X5 and X6 are each independently selected from N and CH.

[0195] In one example, Re and Rf are each independently selected from fluorine, methyl, trifluoromethyl, trifluoromethoxy, fluorine-substituted phenyl, trifluoromethyl-substituted phenyl, and trifluoromethoxy-substituted phenyl; and at least one Re is selected from fluorine-substituted phenyl, trifluoromethyl-substituted phenyl, and trifluoromethoxy-substituted phenyl, and at least one Rf is selected from fluorine-substituted phenyl, trifluoromethyl-substituted phenyl, and trifluoromethoxy-substituted phenyl.

[0196] In one example, the doping material of the P-type charge-generating layer PCGL is selected from the group consisting of the following compounds:

[0197]

[0198]

[0199] In one embodiment of this disclosure, the charge generation layer CGL may further include a metal layer located between the P-type charge generation layer PCGL and the N-type charge generation layer NCGL. For example, it may include a Yb metal layer with a thickness of 1 to 10 angstroms, or a Yb metal layer with a thickness of 11 to 19 angstroms, to improve the conductivity of the charge generation layer CGL.

[0200] In one embodiment of this disclosure, the emission wavelength of the red light-emitting element (RLD) is between 600 and 650 nm. Furthermore, the difference between the peak emission wavelength of the first red light-emitting layer (REL1) and the peak emission wavelength of the second red light-emitting layer (REL2) does not exceed 20 nm, and particularly does not exceed 10 nm. Thus, the emission wavelengths of the first red light-emitting layer (REL1) and the second red light-emitting layer (REL2) are essentially the same, and their spectra are superimposed to improve the color purity of the red light-emitting element (RLD), which is beneficial for improving the color gamut of the light-emitting substrate (PNL).

[0201] Optionally, both the first red emitting layer REL1 and the second red emitting layer REL2 comprise a host material and a phosphorescent dopant material. The host material comprises at least one type. In one example, the host material in either the first red emitting layer REL1 or the second red emitting layer REL2 is a host material capable of simultaneously transporting electrons and holes.

[0202] In another example, the first red emitting layer REL1 or the second red emitting layer REL2 comprises two host materials, which are exciton complexes, isomers, or homologues. This is beneficial for improving exciton utilization, thereby increasing the efficiency of the red light-emitting element (RLD). Furthermore, the peak emission spectrum of the exciton complex in the first red emitting layer REL1 or the second red emitting layer REL2 is at least 20 nm higher than the peak emission spectrum of either host material.

[0203] In one embodiment of this disclosure, the emission wavelength of the green light-emitting element (GLD) is between 500 and 540 nm. Furthermore, the difference between the peak emission wavelength of the first green light-emitting layer (GEL1) and the peak emission wavelength of the second green light-emitting layer (GEL2) does not exceed 20 nm, and particularly does not exceed 10 nm. Thus, the emission wavelengths of the first green light-emitting layer (GEL1) and the second green light-emitting layer (GEL2) are essentially the same, and their spectra are superimposed to improve the color purity of the green light-emitting element (GLD) spectrum, which is beneficial for improving the color gamut of the light-emitting substrate (PNL).

[0204] Optionally, both the first green emitting layer GEL1 and the second green emitting layer GEL2 comprise a host material and a phosphorescent dopant material. The host material comprises at least one type. In one example, the host material in either the first green emitting layer GEL1 or the second green emitting layer GEL2 is a host material capable of simultaneously transporting electrons and holes.

[0205] In another example, the first green emitting layer GEL1 or the second green emitting layer GEL2 comprises two host materials, which are exciton complexes, isomers, or homologues. This is beneficial for improving exciton utilization, thereby increasing the efficiency of the green light-emitting element (GLD). Furthermore, the peak emission spectrum of the exciton complex in the first green emitting layer GEL1 or the second green emitting layer GEL2 is at least 20 nm higher than the peak emission spectrum of either host material.

[0206] For example, the first green emitting layer GEL1 or the second green emitting layer GEL2 contains two main materials: GH-P (P-type main material) and GH-N (N-type main material). Among them,

[0207] 380nm≤λ(GH-P)≤450nm; 420nm≤λ(GH-N)≤480nm;

[0208] λexiplex-λ(GH-P)≥20nm; λexiplex-λ(GH-N)≥20nm.

[0209] λ(GH-P) is the peak value of the emission spectrum of the P-type host material; λ(GH-N) is the peak value of the emission spectrum of the N-type host material; λexciplex is the peak value of the emission spectrum of the excitopolymer complex formed by GH-P and GH-N.

[0210] In one embodiment of this disclosure, the emission wavelength of the blue light-emitting element (BLD) is between 440 and 490 nm. Furthermore, the difference between the peak emission wavelength of the first blue light-emitting layer (BEL1) and the peak emission wavelength of the second blue light-emitting layer (BEL2) does not exceed 20 nm, and particularly does not exceed 10 nm. Thus, the emission wavelengths of the first blue light-emitting layer (BEL1) and the second blue light-emitting layer (BEL2) are essentially the same, and their spectra are superimposed to improve the color purity of the blue light-emitting element (BLD), which is beneficial for improving the color gamut of the light-emitting substrate (PNL).

[0211] Optionally, both the first blue emitting layer BEL1 and the second blue emitting layer BEL2 comprise a host material and a dopant material. The host material is at least one anthracene-containing material, and the dopant material is a fluorescent or phosphorescent dopant. When the host material comprises two materials, these two materials can be isomers or homologues, or they can be an exciton complex. This is beneficial for improving exciton utilization, thereby increasing the efficiency of the blue emitting element (BLD). Furthermore, the peak value of the emission spectrum of the exciton complex in the first blue emitting layer BEL1 or the second blue emitting layer BEL2 is at least 20 nm higher than the peak value of the emission spectrum of any one of the host materials.

[0212] In one embodiment of this disclosure, within the same stacked structure layer, the absolute value of the difference between the LUMO energy level of the hole blocking layer and the LUMO energy level of the electron transport layer is between 0.4 eV and 1.0 eV. This results in a larger energy barrier between the hole blocking layer and the electron transport layer, slowing down the electron transport rate and thus facilitating electron-hole transport balance within the stacked structure layer.

[0213] For example, the absolute value of the difference between the LUMO energy level of the first hole blocking layer HBL1 and the LUMO energy level of the first electron transport layer ETL1 is between 0.4 eV and 1.0 eV, such as 0.4 eV, 0.5 eV, 0.6 eV, 0.7 eV, 0.8 eV, 0.9 eV or 1 eV.

[0214] For another example, the absolute value of the difference between the LUMO energy level of the second hole blocking layer HBL2 and the LUMO energy level of the second electron transport layer ETL2 is between 0.4 eV and 1.0 eV, for example, 0.4 eV, 0.5 eV, 0.6 eV, 0.7 eV, 0.8 eV, 0.9 eV or 1 eV.

[0215] In one embodiment of this disclosure, the absolute value of the HOMO energy level difference between the hole transport layer and the electron blocking layer in the same stacked structure layer is between 0.3 eV and 0.4 eV. This eliminates the decrease in hole transport rate caused by the energy level barrier between the hole transport layer and the electron blocking layer, thereby promoting electron-hole transport balance within the stacked structure layer.

[0216] For example, the absolute value of the HOMO energy level difference between the first hole transport layer HTL1 and the first electron blocking layer EBL1 is between 0.3 eV and 0.4 eV, such as 0.3 eV, 0.31 eV, 0.32 eV, 0.33 eV, 0.34 eV, 0.35 eV, 0.36 eV, 0.37 eV, 0.38 eV, 0.39 eV or 0.4 eV.

[0217] For another example, the absolute value of the HOMO energy level difference between the second hole transport layer HTL2 and the second electron blocking layer EBL2 is between 0.3 eV and 0.4 eV, such as 0.3 eV, 0.31 eV, 0.32 eV, 0.33 eV, 0.34 eV, 0.35 eV, 0.36 eV, 0.37 eV, 0.38 eV, 0.39 eV or 0.4 eV.

[0218] In one embodiment of this disclosure, in the same stacked structure layer, the absolute value of the HOMO energy level difference between the host material in the light-emitting layer and the electron blocking layer is no greater than 0.3 eV. This can reduce the energy level barrier between the host material and the electron blocking layer material, which is beneficial for the electron blocking layer to inject holes into the light-emitting layer.

[0219] For example, the absolute value of the HOMO energy level difference between the host material in the first light-emitting layer EL1 and the first electron blocking layer EBL1 is no greater than 0.3 eV, such as 0.1 eV, 0.12 eV, 0.14 eV, 0.16 eV, 0.18 eV, 0.2 eV, 0.22 eV, 0.24 eV, 0.26 eV, 0.28 eV or 0.3 eV.

[0220] For another example, the absolute value of the HOMO energy level difference between the host material in the second emitting layer EL2 and the second electron blocking layer EBL2 is no greater than 0.3 eV, such as 0.1 eV, 0.12 eV, 0.14 eV, 0.16 eV, 0.18 eV, 0.2 eV, 0.22 eV, 0.24 eV, 0.26 eV, 0.28 eV or 0.3 eV.

[0221] In one embodiment of this disclosure, in the same stacked structure layer, the absolute value of the LUMO energy level difference between the host material in the light-emitting layer and the hole blocking layer is no greater than 0.3 eV. This can reduce the energy level barrier between the host material and the hole blocking layer material, which is beneficial for the hole blocking layer to inject electrons into the light-emitting layer.

[0222] For example, the absolute value of the LUMO energy level difference between the host material in the first light-emitting layer EL1 and the first hole-blocking layer HBL1 is no greater than 0.3 eV, such as 0.1 eV, 0.12 eV, 0.14 eV, 0.16 eV, 0.18 eV, 0.2 eV, 0.22 eV, 0.24 eV, 0.26 eV, 0.28 eV or 0.3 eV.

[0223] For another example, the absolute value of the LUMO energy level difference between the host material in the second light-emitting layer EL2 and the second hole-blocking layer HBL2 is no greater than 0.3 eV, such as 0.1 eV, 0.12 eV, 0.14 eV, 0.16 eV, 0.18 eV, 0.2 eV, 0.22 eV, 0.24 eV, 0.26 eV, 0.28 eV or 0.3 eV.

[0224] In one embodiment of this disclosure, within the same stacked structure layer, the HOMO level of the hole blocking layer is at least 0.3 eV higher than the HOMO level of the host material in the light-emitting layer. This increases the hole transport barrier between the light-emitting layer and the hole blocking layer, facilitating the hole blocking layer's ability to block holes.

[0225] For example, the HOMO level of the first hole blocking layer HBL1 is at least 0.3 eV higher than the HOMO level of the host material in the first light-emitting layer EL1, for example, 0.3 eV, 0.35 eV, 0.4 eV, 0.45 eV, 0.5 eV, 0.55 eV, 0.6 eV, 0.65 eV, 0.7 eV, 0.75 eV, or 0.8 eV higher.

[0226] For another example, the HOMO level of the second hole blocking layer HBL2 is at least 0.3 eV higher than the HOMO level of the host material in the second luminescent layer EL2, for example, 0.3 eV, 0.35 eV, 0.4 eV, 0.45 eV, 0.5 eV, 0.55 eV, 0.6 eV, 0.65 eV, 0.7 eV, 0.75 eV, or 0.8 eV higher.

[0227] In one embodiment of this disclosure, within the same stacked structure, the LUMO energy level of the electron blocking layer is at least 0.3 eV higher than the LUMO energy level of the host material in the light-emitting layer. This increases the electron transport barrier between the light-emitting layer and the electron blocking layer, facilitating the blocking of electrons by the electron blocking layer.

[0228] For example, the LUMO level of the first electron blocking layer EBL1 is at least 0.3 eV higher than the LUMO level of the host material in the first luminescent layer EL1, for example, 0.3 eV, 0.35 eV, 0.4 eV, 0.45 eV, 0.5 eV, 0.55 eV, 0.6 eV, 0.65 eV, 0.7 eV, 0.75 eV, or 0.8 eV higher.

[0229] For another example, the LUMO level of the second electron blocking layer EBL2 is at least 0.3 eV higher than the LUMO level of the host material in the second emitting layer EL2, for example, 0.3 eV, 0.35 eV, 0.4 eV, 0.45 eV, 0.5 eV, 0.55 eV, 0.6 eV, 0.65 eV, 0.7 eV, 0.75 eV, or 0.8 eV higher.

[0230] In one embodiment of this disclosure, the absolute value of the HOMO energy level difference between the P-type charge generation layer PCGL and the second hole transport layer HTL2 is no greater than 0.3 eV. This is beneficial for reducing the hole transport barrier between the P-type charge generation layer PCGL and the second hole transport layer HTL2, and for increasing the rate at which the P-type charge generation layer PCGL injects holes into the second hole transport layer HTL2. In one example, the bulk material of the P-type charge generation layer PCGL is the same as the material of the second hole transport layer HTL2.

[0231] In one embodiment of this disclosure, when the N-type charge generation layer NCGL is in direct contact with the first hole blocking layer HBL1, the absolute value of the LUMO energy level difference between the N-type charge generation layer NCGL and the first hole blocking layer HBL1 is no greater than 0.5 eV. This is beneficial to reducing the electron transport barrier between the P-type charge generation layer PCGL and the first hole blocking layer HBL1, and to increasing the rate at which the P-type charge generation layer PCGL injects electrons into the first hole blocking layer HBL1.

[0232] In one embodiment of this disclosure, the mobility of the hole blocking layer is located at

[0233] 10 -7 ~10 -9 cm 2 V -1 s- 1 @5000V 1 / 2 / m 1 / 2 Within the range.

[0234] In one embodiment of this disclosure, the mobility of the electron transport layer is located at

[0235] 10 -5 ~10 -7 cm 2 V -1 s- 1 @5000V 1 / 2 / m 1 / 2 Within the range.

[0236] In one embodiment of this disclosure, the mobility of the hole transport layer is located at

[0237] 10 -4 ~10 -6 cm 2 V -1 s- 1 @5000V 1 / 2 / m 1 / 2 Within the range.

[0238] In one embodiment of this disclosure, the mobility of the electron blocking layer is located at

[0239] 10 -4 ~10 -7 cm 2 V -1 s- 1 @5000V 1 / 2 / m 1 / 2 Within the range.

[0240] In one embodiment of this disclosure, the mobility of the N-type charge generation layer NCGL is at 10. -5 ~10-7 cm 2 V - 1 s- 1 @5000V 1 / 2 / m 1 / 2 Within the range.

[0241] In one embodiment of this disclosure, the mobility of the P-type charge generation layer PCGL is at 10. -4 ~10 -6 cm 2 V - 1 s- 1 @5000V 1 / 2 / m 1 / 2 Within the range.

[0242] Alternatively, the SCLC (space charge confined current method) can be used to test the mobility of the material.

[0243] In one embodiment of this disclosure, the anode is a high work function electrode material, such as transparent oxide ITO or IZO; it can also be a composite electrode formed by ITO / Ag / ITO, Ag / IZO, CNT / ITO, CNT / IZO, GO / ITO, GO / IZO, etc.

[0244] In one example, the anode material is ITO.

[0245] In one embodiment of this disclosure, the hole injection layer primarily functions to lower the hole injection barrier and improve hole injection efficiency. The hole injection layer can be an inorganic oxide, such as molybdenum oxide, titanium oxide, vanadium oxide, rhenium oxide, ruthenium oxide, chromium oxide, zirconium oxide, hafnium oxide, tantalum oxide, silver oxide, tungsten oxide, manganese oxide, etc. It can also be a dopant of a strong electron-withdrawing system, such as F4TCNQ, HATCN, PPDN, etc. Alternatively, p-type doping can be performed on the hole transport material, and the hole injection layer can be formed through co-evaporation.

[0246]

[0247] In one example, the thickness of the hole injection layer (HIL) is 5–30 nm, for example, 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, or 30 nm.

[0248] In one embodiment of this disclosure, the hole transport layer mainly plays a transport role. The material of this layer has good hole transport characteristics and can be an aromatic amine or carbazole material, such as NPB, TPD, BAFLP, DFLDPBi, TCTA, TAPC, etc.

[0249]

[0250] In one example, the thickness of the first hole transport layer HTL1 is between 10 and 40 nm, for example, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm or 40 nm.

[0251] In one example, the thickness of the second hole transport layer HTL2 is between 30 and 70 nm, for example, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm or 70 nm.

[0252] In one embodiment of this disclosure, the main function of the electron blocking layer is to confine excitons within the light-emitting layer, preventing exciton leakage to both sides of the light-emitting layer and thus avoiding efficiency loss. It also possesses good hole transport characteristics. The electron blocking layer can be made of aromatic amines or carbazoles, such as CBP or PCzPA.

[0253] In one example, the thickness of the first electron blocking layer EBL1R of the red light-emitting element is 5 to 30 nm, for example, 5 nm, 8 nm, 11 nm, 14 nm, 17 nm, 20 nm, 23 nm, 26 nm, 29 nm or 30 nm.

[0254] In one example, the thickness of the second electron blocking layer EBL2R of the red light-emitting element is 5 to 30 nm, for example, 5 nm, 8 nm, 11 nm, 14 nm, 17 nm, 20 nm, 23 nm, 26 nm, 29 nm or 30 nm.

[0255] In one example, the thickness of the first electron blocking layer EBL1G of the green light-emitting element is 5 to 20 nm, for example, 5 nm, 6 nm, 8 nm, 10 nm, 12 nm, 14 nm, 16 nm, 18 nm or 20 nm.

[0256] In one example, the thickness of the second electron blocking layer EBL2G of the green light-emitting element is 5 to 20 nm, for example, 5 nm, 6 nm, 8 nm, 10 nm, 12 nm, 14 nm, 16 nm, 18 nm or 20 nm.

[0257] In one example, the thickness of the first electron blocking layer EBL1B of the blue light-emitting element is 5 to 20 nm, for example, 5 nm, 6 nm, 8 nm, 10 nm, 12 nm, 14 nm, 16 nm, 18 nm or 20 nm.

[0258] In one example, the thickness of the second electron blocking layer EBL2B of the blue light-emitting element is 5 to 20 nm, for example, 5 nm, 6 nm, 8 nm, 10 nm, 12 nm, 14 nm, 16 nm, 18 nm or 20 nm.

[0259] In one embodiment of this disclosure, the light-emitting layer may include a host material and a dopant material. The host material may be one or more types. The dopant material may be a fluorescent dopant or a phosphorescent dopant.

[0260] Optionally, in the light-emitting layer of the blue light-emitting element (BLD), the main material can be selected from anthracene derivatives such as ADN and MADN; the doping material can be pyrene derivatives, fluorene derivatives, perylene derivatives, styrene-amine derivatives, metal complexes, etc., such as TBPe, BDAVBi, DPAVBi, FIrpic, etc.

[0261] Optionally, in the luminescent layer of the green light-emitting element (GLD), the host material can be selected from coumarin dyes, quinacrine copper derivatives, polycyclic aromatic hydrocarbons, diamine anthracene derivatives, carbazole derivatives, such as CBP, DMQA, BA-NPB, Alq3, etc. The doping material can be a metal complex, such as Ir(ppy)3, Ir(ppy)2(acac), etc.

[0262] Optionally, in the light-emitting layer of the red light-emitting element RLD, the main material can be selected from DCM series materials, such as DCM, DCJTB, DCJTI, DCzDBT, etc., and the doping material can be a metal complex, such as Ir(piq)2(acac), PtOEP, Ir(btp)2(acac), etc.

[0263]

[0264] In one example, the thickness of the first red emitting layer REL1 is 40–70 nm, for example, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm or 70 nm.

[0265] In one example, the thickness of the second red emitting layer REL2 is 30–60 nm, for example, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm or 70 nm.

[0266] In one example, the thickness of the first green emitting layer GEL1 is 20–50 nm, for example, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm or 50 nm.

[0267] In one example, the thickness of the second green emitting layer GEL2 is 20–50 nm, for example, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm or 50 nm.

[0268] In one example, the thickness of the first blue emitting layer BEL1 is 10–40 nm, for example, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm or 40 nm.

[0269] In one example, the thickness of the second blue emitting layer BEL2 is 10–40 nm, for example, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm or 40 nm.

[0270] In one embodiment of this disclosure, the host material of the P-type charge generation layer PCGL can be a hole-type material, such as NPB or TPD. In one example, the doping material of the P-type charge generation layer PCGL can be compound M2X or compound M3X.

[0271]

[0272] In one embodiment of this disclosure, the doping material of the N-type charge generation layer NCGL can be an alkali metal such as lithium (Li), sodium (Na), potassium (K) or cesium (Cs), or an alkali metal or alkaline earth metal and its oxide such as magnesium (Mg), strontium (Sr), barium (Ba) or radium (Ra).

[0273] In one example, the host material of the N-type charge generation layer NCGL can be compound M1X, and the doping material can be Li or Yb.

[0274]

[0275] In one example, the thickness of the N-type charge generation layer NCGL is 15–25 nm, for example, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm, 20 nm, 21 nm, 22 nm, 23 nm, 24 nm or 25 nm.

[0276] In one example, the thickness of the P-type charge generation layer PCGL is 5–15 nm, for example, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm or 15 nm.

[0277] In one embodiment of this disclosure, the hole-blocking layer and the electron transport layer are aromatic heterocyclic compounds, such as imidazole derivatives, imidazopyridine derivatives, benzimidazole-phenanthridine derivatives, and other imidazole derivatives; pyrimidine derivatives, triazine derivatives, and other azine derivatives; quinoline derivatives, isoquinoline derivatives, phenanthreneroline derivatives, and other compounds containing a nitrogen-containing six-membered ring structure (including compounds with phosphine oxide substituents on the heterocycle, such as OXD-7, TAZ, p-EtTAZ, BPhen, BCP, TPBi, M4X, etc.).

[0278]

[0279] In one example, the thickness of the first hole blocking layer HBL1 is 5 to 15 nm, for example, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm or 15 nm.

[0280] In one example, the thickness of the second hole blocking layer HBL2 is 5 to 15 nm, for example, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm or 15 nm.

[0281] In one example, the thickness of the second electron transport layer ETL2 is 20–100 nm, for example, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm or 100 nm.

[0282] In one embodiment of this disclosure, the electron injection layer is an alkali metal or a metal, such as LiF, Yb, Mg, Ca, or compounds thereof.

[0283] In one example, the thickness of the electron injection layer (EIL) is 1–15 nm, for example, 1 nm, 2.5 nm, 4 nm, 5.5 nm, 7 nm, 8.5 nm, 10 nm, 11.5 nm, 13 nm, 14.5 nm, or 15 nm.

[0284] In one example, the thickness of the cathode is 10–20 nm, for example, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm or 20 nm.

[0285] In one embodiment of this disclosure, a light extraction layer CPL is located above the cathode and is used to adjust the refractive index. In one example, the thickness of the light extraction layer CPL is in the range of 5-80 nm. In one example, the refractive index of the light extraction layer CPL is greater than 1.8 at a wavelength of 460 nm.

[0286] The following examples, using multiple experimental cases, further illustrate the effects of the light-emitting element LD provided by the embodiments of this disclosure in at least one aspect, such as reducing driving voltage, improving luminous efficiency, and improving device lifespan.

[0287] In these experimental examples, the experimental devices can be prepared using the following methods.

[0288] Step S01) The glass substrate with ITO (as anode) is ultrasonically treated in a cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone-ethanol mixed solvent, and baked in a clean environment until all moisture is removed.

[0289] Step S02): Place the glass substrate with the anode inside the vacuum chamber and evacuate to 1×10⁻⁶. -5 Pa ~ 1×10 -6 Pa. Hole injection material (compound HIM) and hole transport material (compound HTM) (doping amount of 5%) are vacuum co-deposited on the above anode to form hole injection layer HIL.

[0290] Step S03) Hole transport material (compound HTM) is vapor-deposited onto the hole injection layer to form the first hole transport layer HTL1.

[0291] In step S04), an electron blocking material is deposited on the first hole transport layer to form a first electron blocking layer EBL1. It is understood that the electron blocking material can differ depending on the type of light-emitting element (LD). The material for the first electron blocking layer EBL1R of a red light-emitting element is compound REBM; the material for the first electron blocking layer EBL1G of a green light-emitting element is compound GEBM; and the material for the first electron blocking layer EBL1B of a blue light-emitting element is compound BEBM.

[0292] In step S05, a luminescent material is deposited on the first electron blocking layer to form a first luminescent layer EL1. It is understood that different types of light-emitting elements (LDs) use different luminescent materials. In a red light-emitting element (RLD), the main material of the first red luminescent layer REL1 is a premixed composition (1:1) of compounds RH11 and RH12, and the dopant is compound RD1, with a doping ratio of 2%. In a green light-emitting element (GLD), the main material of the first green luminescent layer GEL1 is a premixed composition (1:1) of compounds GH11 and GH12, and the dopant is compound GD1, with a doping ratio of 10%. In a blue light-emitting element (BLD), the first blue luminescent layer BEL1 includes compound BH1 as the main material and compound BD1 as the dopant, with a doping ratio of 1%.

[0293] Step S06) Hole blocking material (compound HBM) is vacuum evaporated on the first light-emitting layer to form the first hole blocking layer HBL1.

[0294] Step S07): An N-type charge generation layer NCGL is first formed on the first hole blocking layer HBL1 by vapor deposition, and then a P-type charge generation layer PCGL is formed on the N-type charge generation layer NCGL by vapor deposition. The doping material of the N-type charge generation layer NCGL is Yb, and the Yb doping ratio is 1%. The host material of the P-type charge generation layer PCGL is compound PHM, and the doping ratio of the doping material in the P-type charge generation layer PCGL is 5%.

[0295] Step S08) Hole transport material (compound HTM) is deposited on the P-type charge generation layer PCGL to form the second hole transport layer HTL2.

[0296] In step S09), an electron blocking material is deposited on the second hole transport layer to form a second electron blocking layer EBL2. It is understood that the electron blocking material can differ depending on the type of light-emitting element (LD). The material for the second electron blocking layer EBL2R of a red light-emitting element is compound REBM; the material for the second electron blocking layer EBL2G of a green light-emitting element is compound GEBM; and the material for the second electron blocking layer EBL2B of a blue light-emitting element is compound BEBM.

[0297] In step S10), a luminescent material is deposited on the second electron blocking layer to form a second luminescent layer EL2. It is understood that different types of light-emitting elements (LDs) use different luminescent materials. In a red light-emitting element (RLD), the main material of the second red luminescent layer REL2 is a premixed composition (1:1) of compounds RH11 and RH12, and the dopant is compound RD1, with a doping ratio of 2%. In a green light-emitting element (GLD), the main material of the second green luminescent layer GEL2 is a premixed composition (1:1) of compounds GH11 and GH12, and the dopant is compound GD1, with a doping ratio of 10%. In a blue light-emitting element (BLD), the second blue luminescent layer BEL2 includes compound BH1 as the main material and compound BD1 as the dopant, with a doping ratio of 1%.

[0298] Step S11) Hole blocking material (compound HBM) is vacuum-deposited on the light-emitting layer to form a second hole blocking layer HBL2.

[0299] Step S12) Electron transport material (compound ETM) is vacuum-deposited on the second hole blocking layer HBL2 to form the second electron transport layer ETL2.

[0300] Step S13) A Yb layer with a thickness of 1 nm is vacuum-deposited on the electron transport layer as an electron injection layer.

[0301] Step S14): A MgAg (1:9) layer is deposited on the electron injection layer as a cathode.

[0302] Step S15) Photoextraction material is vacuum-deposited on the cathode to form a photoextraction layer CPL.

[0303] The structural formulas of some of the materials used in preparing each experimental example are as follows:

[0304]

[0305]

[0306]

[0307] The above outlines the commonalities of the devices fabricated in each experimental example. The following sections will introduce and explain other details and performance characteristics of the devices in each experimental example.

[0308] Experimental group R1

[0309] Three types of red light-emitting elements (RLDs) were fabricated in experimental group R1: device RLD11, device RLD12, and device RLD13.

[0310] Among them, devices RLD11, RLD12, and RLD13 have the same material for the same type of film layer, and the only difference is the thickness of some film layers.

[0311] In devices RLD11, RLD12, and RLD13, the main material of the N-type charge generation layer NCGL is compound NH-Ref; the doping material of the P-type charge generation layer PCGL is compound PD-Ref; and the material of the light extraction layer CPL is compound CPL-Ref.

[0312] In device RLD11, L2 / L3 = 0.1. In device RLD12, L2 / L3 = 0.4. In device RLD13, L2 / L3 = 0.2.

[0313] The performance of devices RLD11, RLD12, and RLD13 was tested, and the test results were normalized based on the test results of device RLD13. The test results are shown in the table below:

[0314] Device RLD11 L2 / L3 = 0.1 102％ 91％ 99％ Device RLD12 L2 / L3 = 0.4 103％ 86％ 97％ Device RLD13 L2 / L3 = 0.2 100％ 100％ 100％

[0315] The test results show that for red light-emitting diodes (RLDs), changes in the ratio of the second dimension L2 to the third dimension L3 have a significant impact on device performance, especially on light extraction efficiency. The optimal light extraction effect is achieved when the ratio of the second dimension L2 to the third dimension L3 is 0.2.

[0316] experimental group G1

[0317] Three types of green light-emitting elements (GLDs) were fabricated in experimental group G1: device GLD11, device GLD12, and device GLD13.

[0318] Among them, devices GLD11, GLD12, and GLD13 have the same material for the same type of film layer, and the only difference is the thickness of some film layers.

[0319] In devices GLD11, GLD12, and GLD13, the main material of the N-type charge generation layer NCGL is compound NH-Ref; the doping material of the P-type charge generation layer PCGL is compound PD-Ref; and the material of the light extraction layer CPL is compound CPL-Ref.

[0320] In device GLD11, L2 / L3 = 0.1. In device GLD12, L2 / L3 = 0.4. In device GLD13, L2 / L3 = 0.24.

[0321] The performance of devices GLD11, GLD12, and GLD13 was tested, and the test results were normalized based on the test results of device GLD13. The test results are shown in the table below:

[0322] Device GLD11 L2 / L3 = 0.1 102％ 93％ 98％ Device GLD12 L2 / L3 = 0.4 100％ 95％ 100％ Device GLD13 L2 / L3 = 0.24 100％ 100％ 100％

[0323] The test results show that for green light-emitting diodes (GLDs), changes in the ratio of the second dimension L2 to the third dimension L3 have a significant impact on device performance, especially on light extraction efficiency. The optimal light extraction effect is achieved when the ratio of the second dimension L2 to the third dimension L3 is 0.2.

[0324] Experimental group B1

[0325] Three blue light-emitting elements (BLDs) were fabricated in experimental group B1: BLD11, BLD12, and BLD13.

[0326] Among them, the materials of the same type of film layer of devices BLD11, BLD12 and BLD13 are the same, and the only difference is the thickness of some film layers.

[0327] In devices BLD11, BLD12, and BLD13, the main material of the N-type charge generation layer NCGL is compound NH-Ref; the doping material of the P-type charge generation layer PCGL is compound PD-Ref; and the material of the light extraction layer CPL is compound CPL-Ref.

[0328] In device BLD11, L2 / L3 = 0.18. In device BLD12, L2 / L3 = 0.55. In device BLD13, L2 / L3 = 0.34.

[0329] The performance of devices BLD11, BLD12, and BLD13 was tested, and the test results were normalized based on the test results of device BLD13. The test results are shown in the table below:

[0330] Device BLD11 L2 / L3 = 0.18 103％ 84％ 95％ Device BLD12 L2 / L3 = 0.S5 102％ 82％ 97％ Device BLD13 L2 / L3 = 0.34 100％ 100％ 100％

[0331] The test results show that for blue light-emitting diodes (BLDs), changes in the ratio of the second dimension L2 to the third dimension L3 have a significant impact on device performance, especially on light extraction efficiency. The optimal light extraction effect is achieved when the ratio of the second dimension L2 to the third dimension L3 is 0.34.

[0332] Experimental group R2

[0333] Three types of red light-emitting elements (RLDs) were fabricated in experimental group R2: device RLD21, device RLD22, and device RLD23.

[0334] Among them, devices RLD21, RLD22, and RLD23 have the same material for the same type of film layer, and the only difference is the thickness of some film layers.

[0335] In devices RLD21, RLD22, and RLD23, the main material of the N-type charge generation layer NCGL is compound NH-Ref; the doping material of the P-type charge generation layer PCGL is compound PD-Ref; and the material of the light extraction layer CPL is compound CPL-Ref.

[0336] In device RLD21, L3 / L = 0.6. In device RLD22, L3 / L = 0.95. In device RLD23, L3 / L = 0.75.

[0337] The performance of devices RLD21, RLD22, and RLD23 was tested, and the test results were normalized based on the test results of device RLD23. The test results are shown in the table below:

[0338] Device RLD21 L3 / L = 0.6 101％ 94％ 96％ Device RLD22 L3 / L = 0.95 102％ 90％ 97％ Device RLD23 L3 / L = 0.75 100％ 100％ 100％

[0339] The test results show that for red light-emitting diodes (RLDs), the ratio of the third dimension L3 to the total thickness L has a significant impact on device performance, especially on light extraction efficiency. The optimal light extraction effect is achieved when the ratio of the third dimension L3 to the total thickness L is 0.75.

[0340] experimental group G2

[0341] Three types of green light-emitting elements (GLDs) were fabricated in experimental group G2: device GLD21, device GLD22, and device GLD23.

[0342] Among them, devices GLD21, GLD22, and GLD23 have the same material for the same type of film layer, and the only difference is the thickness of some film layers.

[0343] In devices GLD21, GLD22, and GLD23, the main material of the N-type charge generation layer NCGL is compound NH-Ref; the doping material of the P-type charge generation layer PCGL is compound PD-Ref; and the material of the light extraction layer CPL is compound CPL-Ref.

[0344] In device GLD21, L3 / L = 0.5. In device GLD22, L3 / L = 0.9. In device GLD23, L3 / L = 0.7.

[0345] The performance of devices GLD21, GLD22, and GLD23 was tested, and the test results were normalized based on the test results of device GLD23. The test results are shown in the table below:

[0346] Device GLD21 L3 / L = 0.5 100％ 86％ 96％ Device GLD22 L3 / L = 0.9 101％ 84％ 99％ Device GLD23 L3 / L = 0.7 100％ 100％ 100％

[0347] The test results show that for green light-emitting diodes (GLDs), the ratio of the third dimension L3 to the total thickness L has a significant impact on device performance, especially on light extraction efficiency. The optimal light extraction effect is achieved when the ratio of the third dimension L3 to the total thickness L is 0.7.

[0348] Experimental group B2

[0349] Three types of blue light-emitting elements (BLDs) were prepared in experimental group B2: device BLD21, device BLD22, and device BLD23.

[0350] Among them, the same type of film layer of devices BLD21, BLD22 and BLD23 are made of the same material, and the only difference is the thickness of some film layers.

[0351] In devices BLD21, BLD22, and BLD23, the main material of the N-type charge generation layer NCGL is compound NH-Ref; the doping material of the P-type charge generation layer PCGL is compound PD-Ref; and the material of the light extraction layer CPL is compound CPL-Ref.

[0352] In device BLD21, L3 / L = 0.4. In device BLD22, L3 / L = 0.9. In device BLD23, L3 / L = 0.62.

[0353] The performance of devices BLD21, BLD22, and BLD23 was tested, and the test results were normalized based on the test results of device BLD23. The test results are shown in the table below:

[0354] Device BLD21 L3 / L = 0.4 105％ 82％ 97％ Device BLD22 L3 / L = 0.9 102％ 86％ 96％ Device BLD23 L3 / L = 0.62 100％ 100％ 100％

[0355] The test results show that for blue light-emitting diodes (BLDs), the ratio of the third dimension L3 to the total thickness L has a significant impact on device performance, especially on light extraction efficiency. The optimal light extraction effect is achieved when the ratio of the third dimension L3 to the total thickness L is 0.62.

[0356] Experimental group R3

[0357] Thirteen red light-emitting diodes (RLDs) were fabricated in experimental group R3, namely devices RLD3ref and RLD301 to RLD312. Devices RLD3ref, RLD301, and RLD312 all have the same film structure and thickness within the same film layer; the only difference lies in the material of some film layers. The thicknesses of each film layer are as follows:

[0358]

[0359]

[0360] In experimental group R3, the L2 / L3 ratio of each red light-emitting element RLD was 0.2, and the L3 / L ratio was 0.75.

[0361] The differences between devices RLD3ref and devices RLD301 to RLD312 mainly lie in the materials of the light extraction layer CPL (CPL-M), the host material of the N-type charge generation layer NCGL (NCGL-Host), and the dopant material of the P-type charge generation layer PCGL (PCGL-Dopant). The specific material combinations are shown in the table below. Performance tests were performed on devices RLD3ref and devices RLD301 to RLD312, and the results were normalized based on the results of device RLD3ref. The test results are shown in the table below.

[0362] Device RLD301 Compound 3-1 PD-Ref CPL-Ref 98％ 102％ 100％ Device RLD302 Compounds 3-5 PD-Ref CPL-Ref 97％ 101％ 103％ Device RLD303 NH-Ref Compound 4-1 CPL-Ref 98％ 101％ 101％ Device RLD304 NH-Ref Compound 4-15 CPL-Ref 99％ 100％ 102％ Device RLD305 Compound 3-1 Compound 4-1 CPL-Ref 94％ 108％ 104％ Device RLD306 Compound 3-1 Compound 4-15 CPL-Ref 93％ 108％ 105％ Device RLD307 Compounds 3-5 Compound 4-1 CPL-Ref 93％ 107％ 105％ Device RLD308 Compounds 3-5 Compound 4-15 CPL-Ref 92％ 106％ 103％ Device RLD309 Compound 3-1 Compound 4-1 Compound 1-1 93％ 110％ 106％ Device RLD310 Compound 3-1 Compound 4-15 Compound 1-1 94％ 112％ 105％ Device RLD311 Compounds 3-5 Compound 4-1 Compounds 1-2 92％ 111％ 104％ Device RLD312 Compounds 3-5 Compound 4-15 Compounds 1-2 92％ 113％ 105％ Device RLD3ref NH-Ref PD-Ref CPL-Ref 100％ 100％ 100％

[0363] The test results show that by optimizing the thickness of each film layer of the red light-emitting element (RLD) and optimizing the materials of the N-type charge generation layer (NCGL), the P-type charge generation layer (PCGL), and the light extraction layer (CPL), the film layer thickness and materials of the red light-emitting element (RLD) achieve a synergistic effect, effectively improving the efficiency and lifespan of the red light-emitting element (RLD) and helping to reduce the voltage of the red light-emitting element (RLD).

[0364] Experimental group G3

[0365] In experimental group G3, thirteen types of green light-emitting devices (GLDs) were fabricated, namely device GLD3ref and devices GLD301 to GLD312. Devices GLD3ref, GLD301, and GLD312 all have the same film structure and thickness within the same film layer; the only difference lies in the material of some film layers. The thicknesses of each film layer are as follows:

[0366] Hole injection layer HIL 10 First Hole Transport Layer (HTL1) 20 First electron blocking layer EBL1G 10 First green luminescent layer GEL1 37 First hole-blocking layer HBL1 5 N-type charge generation layer NCGL 18 P-type charge generation layer PCGL 9 Second Hole Transport Layer (HTL2) 38 Second electron blocking layer EBL2G 10 Second green luminescent layer GEL2 37 Second hole-blocking layer HBL2 5 Second electron transport layer ETL2 35

[0367] In experimental group G3, the L2 / L3 ratio of each green light-emitting element GLD was 0.24, and the L3 / L ratio was 0.7.

[0368] The differences between devices GLD3ref and GLD301 to GLD312 mainly lie in the materials of the photoextraction layer CPL (CPL-M), the host material of the N-type charge generation layer NCGL (NCGL-Host), and the dopant material of the P-type charge generation layer PCGL (PCGL-Dopant). The specific material combinations are shown in the table below. Performance tests were performed on devices GLD3ref and GLD301 to GLD312, and the results were normalized based on the results of device GLD3ref. The test results are shown in the table below.

[0369]

[0370]

[0371] The test results show that by optimizing the thickness of each film layer of the green light-emitting element (GLD) and optimizing the materials of the N-type charge generation layer (NCGL), the P-type charge generation layer (PCGL), and the light extraction layer (CPL), the film layer thickness and materials of the green light-emitting element (GLD) achieve a synergistic effect, effectively improving the efficiency and lifespan of the green light-emitting element (GLD) and helping to reduce the voltage of the green light-emitting element (GLD).

[0372] Experimental group B3

[0373] In experimental group B3, thirteen blue light-emitting diodes (BLDs) were fabricated, namely device BLD3ref and devices BLD301 to BLD312. Devices BLD3ref, BLD301, and BLD312 all have the same film structure and thickness within the same film layer; the only difference lies in the material of some film layers. The thicknesses of each film layer are as follows:

[0374]

[0375]

[0376] In experimental group B3, the L2 / L3 ratio of each blue light-emitting element (BLD) was 0.34, and the L3 / L ratio was 0.62.

[0377] The differences between devices BLD3ref and BLD301 to BLD312 mainly lie in the materials of the light extraction layer CPL (CPL-M), the host material of the N-type charge generation layer NCGL (NCGL-Host), and the dopant material of the P-type charge generation layer PCGL (PCGL-Dopant). The specific material combinations are shown in the table below. Performance tests were performed on devices BLD3ref and BLD301 to BLD312, and the results were normalized based on the results of device BLD3ref. The test results are shown in the table below.

[0378] Device BLD301 Compound 3-1 PD-Ref CPL-Ref 98％ 100％ 101％ Device BLD302 Compounds 3-5 PD-Ref CPL-Ref 99％ 101％ 102％ Device BLD303 NH-Ref Compound 4-1 CPL-Ref 101％ 101％ 101％ Device BLD304 NH-Ref Compound 4-15 CPL-Ref 101％ 102％ 102％ Device BLD305 Compound 3-1 Compound 4-1 CPL-Ref 95％ 105％ 106％ Device BLD306 Compound 3-1 Compound 4-15 CPL-Ref 94％ 104％ 105％ Device BLD307 Compounds 3-5 Compound 4-1 CPL-Ref 95％ 104％ 106％ Device BLD308 Compounds 3-5 Compound 4-15 CPL-Ref 93％ 106％ 107％ Device BLD309 Compound 3-1 Compound 4-1 Compound 1-1 94％ 110％ 108％ Device BLD310 Compound 3-1 Compound 4-15 Compound 1-1 95％ 112％ 106％ Device BLD311 Compounds 3-5 Compound 4-1 Compounds 1-2 94％ 109％ 107％ Device BLD312 Compounds 3-5 Compound 4-15 Compounds 1-2 93％ 111％ 106％ Device BLD3ref NH-Ref PD-Ref CPL-Ref 100％ 100％ 100％

[0379] The test results show that by optimizing the thickness of each film layer of the blue light-emitting element (BLD) and optimizing the materials of the N-type charge generation layer (NCGL), the P-type charge generation layer (PCGL), and the light extraction layer (CPL), the film layer thickness and materials of the blue light-emitting element (BLD) achieve a synergistic effect, effectively improving the efficiency and lifespan of the blue light-emitting element (BLD) and helping to reduce the voltage of the blue light-emitting element (BLD).

[0380] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the appended claims.

Claims

1. A light-emitting element, characterized in that, It includes an anode, a first hole transport region, a first light-emitting layer, a first electron transport region, a charge generation layer, a second hole transport region, a second light-emitting layer, a second electron transport region, a cathode, and a light extraction layer, which are stacked sequentially; the first hole transport region includes a first hole transport layer and a first electron blocking layer stacked together. Wherein, the total thickness L is the distance between the anode and the cathode; the second dimension L2 is the distance between the first light-emitting layer and the anode; and the third dimension L3 is the distance between the first hole transport layer and the second electron transport region. 0.1≤L2 / L3≤0.45; 0.5≤L³ / L≤0.9; The structural formula of the material of the light extraction layer is shown in Chemical Formula 1: Chemical Formula 1 Ar1, Ar2, and Ar3 are each independently selected from the group consisting of the following structures: ; Furthermore, at least one of Ar1, Ar2, and Ar3 is selected from the group consisting of the following structures: ； L a L b Each is independently selected from arylene groups with 6 to 60 carbon atoms (single bond, substituted or unsubstituted) and heteroarylene groups with 2 to 60 carbon atoms (substituted or unsubstituted); The charge generation layer includes an N-type charge generation layer stacked on the side of the first electron transport region away from the anode and a P-type charge generation layer located on the side of the N-type charge generation layer away from the anode; the structural formula of the main material of the N-type charge generation layer is shown in Chemical Formula 3: Chemical formula 3 Among them, X1, X2, X3, and X4 are each independently selected from N or C(R4), and at least two of X1, X2, X3, and X4 are selected from N; R4 may appear the same or different each time, and each is independently selected from hydrogen, deuterium, substituted or unsubstituted alkyl with 1 to 60 carbon atoms, substituted or unsubstituted alkenyl with 2 to 60 carbon atoms, substituted or unsubstituted alkynyl with 2 to 60 carbon atoms, substituted or unsubstituted alkoxy with 1 to 60 carbon atoms, substituted or unsubstituted cycloalkyl with 3 to 10 carbon atoms, substituted or unsubstituted heterocyclic alkyl with 1 to 10 carbon atoms, substituted or unsubstituted Cycloalkenyl groups with 3 to 10 carbon atoms, heterocyclic alkenyl groups with 1 to 10 carbon atoms (substituted or unsubstituted), aryl groups with 6 to 60 carbon atoms (substituted or unsubstituted), aryloxy groups with 6 to 60 carbon atoms (substituted or unsubstituted), arylthio groups with 6 to 60 carbon atoms (substituted or unsubstituted), heteroaryl groups with 1 to 60 carbon atoms (substituted or unsubstituted), monovalent non-aromatic condensed polycyclic groups (substituted or unsubstituted), and monovalent non-aromatic condensed heteropolycyclic groups (substituted or unsubstituted). Ar4, Ar5, Ar6, and Ar7 may be the same or different, and each is independently selected from the group consisting of: hydrogen, deuterium, tritium, halogen, cyano, nitro, aryl group with 6 to 60 substituted or unsubstituted carbon atoms, heterocyclic group with 2 to 60 substituted or unsubstituted carbon atoms containing at least one heteroatom from O, N, S, Si, and P, aliphatic ring with 3 to 60 substituted or unsubstituted carbon atoms, fused ring group of aromatic ring with 6 to 60 substituted or unsubstituted carbon atoms, and substituted or unsubstituted... Alkyl groups having 1 to 50 carbon atoms, alkenyl groups having 2 to 20 carbon atoms (substituted or unsubstituted), alkynyl groups having 2 to 20 carbon atoms (substituted or unsubstituted), alkoxy groups having 1 to 30 carbon atoms (substituted or unsubstituted), aryloxy groups having 6 to 30 carbon atoms (substituted or unsubstituted), alkylsilyl groups having 3 to 60 carbon atoms (substituted or unsubstituted), arylsilyl groups having 18 to 60 carbon atoms (substituted or unsubstituted), and alkylarylsilyl groups having 8 to 60 carbon atoms (substituted or unsubstituted). The structural formula of the doped material of the P-type charge generation layer is shown in chemical formula 4: Structural Formula 4 Among them, X5 and X6 are each independently selected from C(Rg), N, and Si(Rg); Y1 and Y2 are each independently selected from N(Rh), O, and S; Ra, Rb, Rc, Rd, Rg, and Rh are each independently selected from halogens, cyano groups, substituted or unsubstituted phenyl groups, substituted or unsubstituted biphenyl groups, substituted or unsubstituted terphenyl groups, substituted or unsubstituted fluorene groups, substituted or unsubstituted adamantane groups, and substituted or unsubstituted heteroaryl groups. Re and Rf are each independently selected from deuterium, halogen groups, cyano, heteroaryl groups with 3 to 20 substituted or unsubstituted carbon atoms, aryl groups with 6 to 20 substituted or unsubstituted carbon atoms, alkyl groups with 1 to 5 substituted or unsubstituted carbon atoms, haloalkyl groups with 1 to 10 substituted or unsubstituted carbon atoms, cycloalkyl groups with 3 to 10 substituted or unsubstituted carbon atoms, heterocycloalkyl groups with 2 to 10 substituted or unsubstituted carbon atoms, alkoxy groups with 1 to 10 substituted or unsubstituted carbon atoms, alkylthio groups with 1 to 10 substituted or unsubstituted carbon atoms, aryloxy groups with 6 to 18 substituted or unsubstituted carbon atoms, arylthio groups with 6 to 18 carbon atoms, phosphoxy groups with 6 to 24 carbon atoms, and alkylsulfonyl groups with 6 to 18 substituted or unsubstituted carbon atoms. a and b are independent integers from 1 to 5.

2. The light-emitting element according to claim 1, characterized in that, The material of the light extraction layer is selected from the group consisting of the following compounds: 。 3. The light-emitting element according to claim 1, characterized in that, At least one of the Ar4, Ar5, Ar6, and Ar7 groups is selected from the group consisting of: ； Ar8, Ar9, Ar 10 Ar 11 Ar 12 Ar 13 Ar 14 Each is independently selected from phenyl, diphenyl, triphenyl, naphthyl, anthracene, phenanthryl, pyridyl, pyrimidinyl, quinolinyl, isoquinolinyl, or phenanthrolineyl; L c L d L e L f Each is independently selected from single bonds, phenylene, diphenylene, terphenylene, naphthylene, anthraceneylene, phenanthrene, pyridylene, and pyrimidinyl.

4. The light-emitting element according to claim 1, characterized in that, At least one of the Ar4, Ar5, Ar6, and Ar7 groups is selected from the group consisting of: 。 5. The light-emitting element according to claim 1, characterized in that, The host material of the N-type charge generation layer is selected from the group consisting of the following compounds: 。 6. The light-emitting element according to claim 1, characterized in that, The doping material of the P-type charge generation layer is selected from the group consisting of the following compounds: 。 7. The light-emitting element according to claim 1, characterized in that, In the P-type charge generation layer, the mass content of the doped material is between 3% and 10%. In the N-type charge generation layer, the mass content of the doped material is between 0.5% and 11.5%.

8. The light-emitting element according to any one of claims 1 to 7, characterized in that, The light-emitting element is a red light-emitting element, and 0.1≤L2 / L3≤0.3; Alternatively, the light-emitting element is a green light-emitting element, where 0.15 ≤ L2 / L3 ≤ 0.35; Alternatively, the light-emitting element is a blue light-emitting element, and 0.25≤L2 / L3≤0.

45.

9. The light-emitting element according to any one of claims 1 to 7, characterized in that, The light-emitting element is a red light-emitting element, and 0.65≤L3 / L≤0.9; Alternatively, the light-emitting element is a green light-emitting element, with a value of 0.6 ≤ L³ / L ≤ 0.85; Alternatively, the light-emitting element is a blue light-emitting element, with 0.5 ≤ L3 / L ≤ 0.

8.

10. The light-emitting element according to any one of claims 1 to 7, characterized in that, The light-emitting element is a red light-emitting element with a wavelength of 250nm ≤ L ≤ 300nm; Alternatively, the light-emitting element is a green light-emitting element with 200nm≤L≤250nm; Alternatively, the light-emitting element is a blue light-emitting element with 150nm ≤ L ≤ 200nm.

11. A light-emitting substrate comprising at least one light-emitting element as described in any one of claims 1 to 10.

12. A display device comprising the light-emitting substrate of claim 11.

Images