Display substrate and display device

Abstract

Embodiments of the present application relate to the technical field of display, and provide a display substrate and a display device, for use in improving the light emitting efficiency of light-emitting devices. The display substrate comprises a base substrate, and a first light-emitting device, a second light-emitting device, and a third light-emitting device which are provided on the base substrate. Each light-emitting device comprises a first electrode, a second electrode, a first light-emitting unit, a second light-emitting unit and a charge generation unit. There is a first distance between the surface of the first electrode close to the first light-emitting unit and the surface of the first charge generation layer away from the first light-emitting unit; there is a first difference between the first distance corresponding to the third light-emitting device and the first distance corresponding to the first light-emitting device; there is a second difference between the first distance corresponding to the second light-emitting device and the first distance corresponding to the first light-emitting device; and the ratio of the first difference to the second difference ranges from 1.8 to 2.5. The display substrate is used for displaying an image.

Description

Display substrate and display device Technical Field

[0001] This disclosure relates to the field of display technology, and in particular to a display substrate and a display device. Background Technology

[0002] OLED (Organic Light Emitting Diode) display substrates are widely used in display screens for mobile phones, tablets, automotive displays, and other devices due to their advantages such as being all-solid-state, having a fast response time, and a wide operating temperature range.

[0003] Summary of the Invention

[0004] On one hand, a display substrate is provided. The display substrate includes a substrate and a first light-emitting device, a second light-emitting device, and a third light-emitting device disposed on the substrate. The first light-emitting device is used to emit light of a first color. The second light-emitting device is used to emit light of a second color; the wavelength of the second color light is greater than the wavelength of the first color light. The third light-emitting device is used to emit light of a third color; the wavelength of the third color light is greater than the wavelength of the second color light.

[0005] Each of the first, second, and third light-emitting devices includes a first electrode, a second electrode, a first light-emitting unit, a second light-emitting unit, and a charge-generating unit. The first and second electrodes are disposed opposite each other along a first direction, with the second electrode closer to the substrate relative to the first electrode. The first and second light-emitting units are located between the first and second electrodes and are stacked along the first direction; the second light-emitting unit is further away from the first electrode relative to the first light-emitting unit. The charge-generating unit is located between the first and second light-emitting units; the charge-generating unit includes a first charge-generating layer and a second charge-generating layer stacked along the first direction, with the second charge-generating layer further away from the first electrode relative to the first charge-generating layer.

[0006] Wherein, there is a first distance between the surface of the first electrode near the first light-emitting unit and the surface of the first charge-generating layer away from the first light-emitting unit; there is a first difference between the first distance corresponding to the third light-emitting device and the first distance corresponding to the first light-emitting device; there is a second difference between the first distance corresponding to the second light-emitting device and the first distance corresponding to the first light-emitting device; the ratio between the first difference and the second difference is in the range of 1.8 to 2.5.

[0007] In some embodiments, there is a second distance between the surface of the second electrode near the second light-emitting unit and the surface of the second charge-generating layer away from the second light-emitting unit. The second distance corresponding to the third light-emitting device has a third difference with the second distance corresponding to the second light-emitting device; the second distance corresponding to the second light-emitting device has a fourth difference with the second distance corresponding to the first light-emitting device; the ratio between the third difference and the fourth difference ranges from 1.0 to 1.5.

[0008] In some embodiments, the ratio between the first distance and the second distance in the first light-emitting device ranges from 0.65 to 0.90; and / or, the ratio between the first distance and the second distance in the second light-emitting device ranges from 0.60 to 0.85; and / or, the ratio between the first distance and the second distance in the third light-emitting device ranges from 0.50 to 0.80.

[0009] In some embodiments, the range of the second distance in the first light-emitting device is within And / or, the range of the second distance in the second light-emitting device is within And / or, the range of the second distance in the third light-emitting device is within

[0010] In some embodiments, in the first light-emitting device, the first light-emitting unit includes a first light-emitting layer; the second light-emitting unit includes a second light-emitting layer. In the second light-emitting device, the first light-emitting unit includes a third light-emitting layer; the second light-emitting unit includes a fourth light-emitting layer. In the third light-emitting device, the first light-emitting unit includes a fifth light-emitting layer; the second light-emitting unit includes a sixth light-emitting layer. Wherein, the dimension of the fifth light-emitting layer along the first direction has a fifth difference with the dimension of the first light-emitting layer along the first direction; the dimension of the third light-emitting layer along the first direction has a sixth difference with the dimension of the first light-emitting layer along the first direction; the ratio between the fifth difference and the sixth difference ranges from 0.8 to 3.0; and / or, the dimension of the sixth light-emitting layer along the first direction has a seventh difference with the dimension of the second light-emitting layer along the first direction, and the dimension of the fourth light-emitting layer along the first direction has an eighth difference with the dimension of the second light-emitting layer along the first direction; the ratio between the seventh difference and the eighth difference ranges from 0.8 to 3.0.

[0011] In some embodiments, the first light-emitting unit further includes a first functional unit located between the first type of light-emitting layer and the charge-generating unit. The first type of light-emitting layer is a first light-emitting layer, a third light-emitting layer, or a fifth light-emitting layer. The first functional unit includes a first functional layer. The second light-emitting unit further includes a second functional unit located between the second type of light-emitting layer and the second electrode. The second type of light-emitting layer is a second light-emitting layer, a fourth light-emitting layer, or a sixth light-emitting layer. The second functional unit includes a third functional layer, a fourth functional layer, and a fifth functional layer arranged sequentially along the direction close to the second electrode.

[0012] In some embodiments, the first functional unit further includes a second functional layer located between the first functional layer and the charge generation unit.

[0013] In some embodiments, in the same light-emitting device, the dimension of the third functional layer along the first direction is greater than or equal to the dimension of the first functional layer along the first direction; the light-emitting device is any one of the first light-emitting device, the second light-emitting device, and the third light-emitting device.

[0014] In some embodiments, in the same light-emitting device, the ratio between the dimension of the fourth functional layer along the first direction and the dimension of the second functional layer along the first direction is in the range of 1.5 to 2.5; the light-emitting device is any one of the first light-emitting device, the second light-emitting device, and the third light-emitting device.

[0015] In some embodiments, the material of the first charge generation layer and / or the material of the fifth functional layer includes a first host material and a first doped material. The first host material is a hole-type material. The first doped material is configured to p-type dope the first host material. When the material of the first charge generation layer includes the first host material and the first doped material, the mass percentage of the first doped material in the material of the first charge generation layer is less than the mass percentage of the first host material in the material of the first charge generation layer. When the material of the fifth functional layer includes the first host material and the first doped material, the mass percentage of the first doped material in the material of the fifth functional layer is less than the mass percentage of the first host material in the material of the fifth functional layer.

[0016] In some embodiments, the first doped material is selected from any of the structures shown in the following general formula (I).

[0017] Wherein, A is any one of a three-membered ring, a four-membered ring, a five-membered ring, and a six-membered ring. R1, R2, R3, R4, R5, and R6 may be the same or different, and are independently selected from any one of a halogen, a cyano group, a substituted aryl group, and a substituted or unsubstituted heteroaryl group; and, in the case where R1, R2, R3, R4, R5, or R6 is a substituted aryl group, the substituent of the aryl group includes at least one electron-withdrawing group.

[0018] In some embodiments, at least one of R1, R2, R3, R4, R5, and R6 is a cyano group.

[0019] In some embodiments, the first doped material is selected from any of the structures shown in the following general formula (II).

[0020] Where X1 and X2 are the same or different, and are independently selected from C(R) a ), N and Si(R) bY1 and Y2 are either the same or different, and are independently selected from N(R). c Ar1, Ar2, Ar3, and Ar4 may be the same or different, and are independently selected from any one of halogen, cyano, substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted fluorenyl, substituted or unsubstituted adamantyl, and substituted or unsubstituted heteroaryl; or may be connected to adjacent groups to form substituted or unsubstituted rings. a R b and R c Whether identical or different, each is independently selected from hydrogen, deuterium, halogen, cyano, substituted or unsubstituted C3–C20 heteroaryl, substituted or unsubstituted C6–C20 aryl, substituted or unsubstituted C1–C5 alkyl, substituted or unsubstituted C1–C10 haloalkyl, substituted or unsubstituted C3–C10 cycloalkyl, substituted or unsubstituted C2–C10 heterocycloalkyl, substituted or unsubstituted C1–C10 alkoxy, substituted or unsubstituted C1–C10 alkylthio, substituted or unsubstituted C6–C18 aryloxy, substituted or unsubstituted C6–C18 arylthio, substituted or unsubstituted C6–C24 phosphoroxy, and substituted or unsubstituted C6–C18 alkylsulfonyl. m and n may be identical or different, each independently selected from 1, 2, 3, 4, and 5.

[0021] In some embodiments, the mass percentage of the first doped material in the material of the first charge generation layer is greater than or equal to 0.5% and less than or equal to 10%; and / or, the mass percentage of the first doped material in the material of the fifth functional layer is greater than or equal to 0.5% and less than or equal to 10%.

[0022] In some embodiments, the material of the second charge generation layer includes a second host material and a second doped material; in the second charge generation layer, the mass percentage of the second doped material is less than the mass percentage of the second host material. The second host material is selected from any of the structures shown in general formula (III).

[0023] Among them, X3, X4, X5, and X6 may be the same or different, and are independently selected from C(R). dAr5, Ar6, Ar7, and Ar8 are either hydrogen, deuterium, tritium, halogen, cyano, nitro, substituted or unsubstituted C6–C60 aryl, substituted or unsubstituted C3–C60 alicyclic, substituted or unsubstituted C6–C60 aromatic fused ring, substituted or unsubstituted C1–C50 alkyl, substituted or unsubstituted C2–C20 alkenyl, substituted or unsubstituted C2–C20 alkynyl, etc. The heterocyclic group comprises any one of the following: substituted or unsubstituted C1-C30 alkoxy group, substituted or unsubstituted C6-C30 aryloxy group, substituted or unsubstituted C3-C60 alkylsilyl group, substituted or unsubstituted C18-C60 arylsilyl group, substituted or unsubstituted C8-C60 alkylarylsilyl group, and substituted or unsubstituted C2-C60 heterocyclic group; and the heterocyclic group comprises at least one of O, N, S, Si, and P. d It is selected from hydrogen, deuterium, substituted or unsubstituted C1-C60 alkyl, substituted or unsubstituted C2-C60 alkenyl, substituted or unsubstituted C2-C60 alkynyl, substituted or unsubstituted C1-C60 alkoxy, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C1-C10 heterocyclic alkyl, substituted or unsubstituted C3-C10 cycloalkenyl, substituted or unsubstituted C1-C10 heterocyclic alkenyl, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C6-C60 aryloxy, substituted or unsubstituted C6-C60 arylthio, substituted or unsubstituted C1-C60 heteroaryl, substituted or unsubstituted monovalent nonaromatic condensed polycyclic and substituted or unsubstituted monovalent nonaromatic condensed heterocyclic.

[0024] In some embodiments, the second doping material includes one or any combination of alkali metals, alkaline earth metals, transition metals, alkali metal compounds, alkaline earth metal compounds, and transition metal compounds.

[0025] In some embodiments, the mass percentage of the second doped material in the material of the second charge generation layer is greater than or equal to 0.5% and less than or equal to 3%.

[0026] In some embodiments, the wavelength range of the light emitted by the first light-emitting layer and the second light-emitting layer is 440nm to 490nm; and / or, the wavelength range of the light emitted by the third light-emitting layer and the fourth light-emitting layer is 500nm to 540nm; and / or, the wavelength range of the light emitted by the fifth light-emitting layer and the sixth light-emitting layer is 600nm to 650nm.

[0027] In some embodiments, the ratio of the electron mobility of the material of the second light-emitting layer to the electron mobility of the material of the first light-emitting layer ranges from 0.01 to 100; the ratio of the hole mobility of the material of the second light-emitting layer to the hole mobility of the material of the first light-emitting layer ranges from 0.01 to 100; and / or, the ratio of the electron mobility of the material of the fourth light-emitting layer to the electron mobility of the material of the third light-emitting layer ranges from 0.01 to 100; the ratio of the hole mobility of the material of the fourth light-emitting layer to the hole mobility of the material of the third light-emitting layer ranges from 0.01 to 100; and / or, the ratio of the electron mobility of the material of the sixth light-emitting layer to the electron mobility of the material of the fifth light-emitting layer ranges from 0.01 to 100; the ratio of the hole mobility of the material of the sixth light-emitting layer to the hole mobility of the material of the fifth light-emitting layer ranges from 0.01 to 100.

[0028] In some embodiments, the second electrode is an anode; the first functional unit and the second functional unit are hole transport units; in the same light-emitting device, the absolute value of the difference between the highest occupied molecular orbital energy level of the material of the second functional layer and the highest occupied molecular orbital energy level of the material of the first functional layer is greater than or equal to 0.1 eV and less than or equal to 0.4 eV; and / or, the absolute value of the difference between the highest occupied molecular orbital energy level of the material of the fourth functional layer and the highest occupied molecular orbital energy level of the material of the third functional layer is greater than or equal to 0.1 eV and less than or equal to 0.4 eV; wherein, the light-emitting device is any one of the first light-emitting device, the second light-emitting device, and the third light-emitting device.

[0029] In some embodiments, the second electrode is an anode; the first functional unit and the second functional unit are hole transport units. In the same light-emitting device, the hole mobility of the third functional layer is greater than or equal to the hole mobility of the first functional layer; the light-emitting device is any one of the first light-emitting device, the second light-emitting device, and the third light-emitting device.

[0030] In some embodiments, the second electrode is an anode; the first functional unit and the second functional unit are hole transport units; in the same light-emitting device, the hole mobility of the fourth functional layer is greater than or equal to the hole mobility of the second functional layer; the light-emitting device is any one of the first light-emitting device, the second light-emitting device and the third light-emitting device.

[0031] In some embodiments, the second electrode is an anode; the first functional unit and the second functional unit are hole transport units. In the same light-emitting device, the absolute value of the difference between the highest occupied molecular orbital energy level of the material of the first charge-generating layer and the highest occupied molecular orbital energy level of the material of the second functional layer is less than or equal to 0.3 eV. The light-emitting device is any one of a first light-emitting device, a second light-emitting device, and a third light-emitting device.

[0032] In some embodiments, the first light-emitting unit further includes a third functional unit located between the first type of light-emitting layer and the first electrode. The third functional unit includes a sixth functional layer, a seventh functional layer, and an eighth functional layer arranged sequentially along the direction close to the first electrode. The second light-emitting unit further includes a fourth functional unit located between the second type of light-emitting layer and the second charge-generating layer; the fourth functional unit includes a ninth functional layer. The third and fourth functional units are electron transport units.

[0033] In some embodiments, in the same light-emitting device, the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the material of the sixth functional layer and the lowest unoccupied molecular orbital energy level of the material of the seventh functional layer is greater than or equal to 0.4 eV and less than or equal to 1.0 eV; and / or, the fourth functional unit further includes a tenth functional layer located between the ninth functional layer and the charge generating unit, the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the material of the ninth functional layer and the lowest unoccupied molecular orbital energy level of the material of the tenth functional layer is greater than or equal to 0.4 eV and less than or equal to 1.0 eV; wherein, the light-emitting device is any one of the first light-emitting device, the second light-emitting device, and the third light-emitting device.

[0034] In some embodiments, within the same light-emitting device, the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the material of the second charge-generating layer and the lowest unoccupied molecular orbital energy level of the material of the ninth functional layer is less than or equal to 0.5 eV; or, the fourth functional unit further includes a tenth functional layer located between the ninth functional layer and the charge-generating unit, wherein the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the material of the second charge-generating layer and the lowest unoccupied molecular orbital energy level of the material of the tenth functional layer is less than or equal to 0.5 eV. The light-emitting device is any one of the first, second, and third light-emitting devices.

[0035] In some embodiments, the material of the light-emitting layer includes a third host material and a guest material. The mass percentage of the guest material in the material of the light-emitting layer is less than the mass percentage of the third host material in the material of the light-emitting layer. The light-emitting layer is any one of a first light-emitting layer, a second light-emitting layer, a third light-emitting layer, a fourth light-emitting layer, a fifth light-emitting layer, and a sixth light-emitting layer.

[0036] In some embodiments, in the same first light-emitting unit, the absolute value of the difference between the highest occupied molecular orbital energy level of the third host material and the highest occupied molecular orbital energy level of the material of the first functional layer is less than or equal to 0.3 eV; and / or, in the same second light-emitting unit, the absolute value of the difference between the highest occupied molecular orbital energy level of the third host material and the highest occupied molecular orbital energy level of the material of the third functional layer is less than or equal to 0.3 eV.

[0037] In some embodiments, in the same first light-emitting unit, the difference between the lowest unoccupied molecular orbital energy level of the material of the first functional layer and the lowest unoccupied molecular orbital energy level of the third host material is greater than or equal to 0.3 eV; and / or, in the same second light-emitting unit, the difference between the lowest unoccupied molecular orbital energy level of the material of the third functional layer and the lowest unoccupied molecular orbital energy level of the third host material is greater than or equal to 0.3 eV.

[0038] In some embodiments, where the first light-emitting unit further includes a sixth functional layer and the second light-emitting unit further includes a ninth functional layer; in the same first light-emitting unit, the difference between the highest occupied molecular orbital energy level of the material of the sixth functional layer and the highest occupied molecular orbital energy level of the third host material is greater than or equal to 0.3 eV; and / or, in the same second light-emitting unit, the difference between the highest occupied molecular orbital energy level of the material of the ninth functional layer and the highest occupied molecular orbital energy level of the third host material is greater than or equal to 0.3 eV.

[0039] In some embodiments, where the first light-emitting unit further includes a sixth functional layer and the second light-emitting unit further includes a ninth functional layer; in the same first light-emitting unit, the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the material of the sixth functional layer and the lowest unoccupied molecular orbital energy level of the third host material is less than or equal to 0.3 eV; and / or, in the same second light-emitting unit, the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the material of the ninth functional layer and the lowest unoccupied molecular orbital energy level of the third host material is less than or equal to 0.3 eV.

[0040] On the other hand, a display device is provided. The display device includes a driver chip and a display substrate as described in any of the above embodiments. The driver chip is used to drive the display substrate to perform display. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in this disclosure, the accompanying drawings used in some embodiments of this disclosure will be briefly described below. Obviously, the drawings described below are only drawings of some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings. In addition, the drawings described below can be regarded as schematic diagrams and are not intended to limit the actual size of the product, the actual flow of the method, the actual timing of the signals, etc. involved in the embodiments of this disclosure.

[0042] Figure 1 is a structural diagram of a display device according to some embodiments;

[0043] Figure 2 is a structural diagram of a display substrate according to some embodiments;

[0044] Figure 3 is a structural diagram of a display substrate according to some other embodiments;

[0045] Figure 4 is a structural diagram of a display substrate according to some other embodiments;

[0046] Figure 5 is a structural diagram of a display substrate according to some other embodiments;

[0047] Figure 6 is a structural diagram of a light-emitting device according to some embodiments;

[0048] Figure 7 is a structural diagram of a display substrate according to some other embodiments;

[0049] Figure 8 is a structural diagram of a light-emitting device according to some other embodiments;

[0050] Figure 9 is a structural diagram of a light-emitting device according to some other embodiments;

[0051] Figure 10 is a structural diagram of a light-emitting device according to some other embodiments;

[0052] Figure 11 is a structural diagram of a display substrate according to some other embodiments;

[0053] Figure 12 is a structural diagram of a light-emitting device according to some other embodiments;

[0054] Figure 13 is a structural diagram of a light-emitting device according to some other embodiments;

[0055] Figure 14 is a structural diagram of a light-emitting device according to some other embodiments;

[0056] Figure 15 is a structural diagram of a display substrate according to some other embodiments;

[0057] Figure 16 is a structural diagram of a light-emitting device according to some other embodiments. Detailed Implementation

[0058] The technical solutions in some embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments provided in this disclosure are within the scope of protection of this disclosure.

[0059] Unless the context otherwise requires, throughout the specification and claims, the term "comprise" and its other forms, such as the third-person singular "comprises" and the present participle "comprising," are interpreted as open-ended and encompassing, meaning "including, but not limited to." In the description of the specification, terms such as "one embodiment," "some embodiments," "exemplary embodiments," "example," "specific example," or "some examples," etc., are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this disclosure. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics mentioned may be included in any suitable manner in any one or more embodiments or examples.

[0060] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this disclosure, unless otherwise stated, "a plurality of" means two or more.

[0061] "At least one of A, B and C" has the same meaning as "at least one of A, B or C", both including the following combinations of A, B and C: only A, only B, only C, combinations of A and B, combinations of A and C, combinations of B and C, and combinations of A, B and C.

[0062] "A and / or B" includes the following three combinations: A only, B only, and a combination of A and B.

[0063] As used herein, “about,” “approximately,” or “approximately” includes the stated value and the average value within an acceptable range of deviation from the given value, wherein the acceptable range of deviation is determined by a person skilled in the art taking into account the measurement under discussion and the error associated with the measurement of the given quantity (i.e., the limitations of the measurement system).

[0064] As used herein, “parallel,” “perpendicular,” and “equal” include the described situation and situations that are similar to the described situation, within an acceptable range of deviation, which is determined by those skilled in the art taking into account the measurement under discussion and the error associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, “parallel” includes absolute parallelism and approximate parallelism, where an acceptable range of deviation for approximate parallelism may be, for example, within 5°; “perpendicular” includes absolute perpendicularity and approximate perpendicularity, where an acceptable range of deviation for approximate perpendicularity may also be, for example, within 5°; “equal” includes absolute equality and approximate equality, where an acceptable range of deviation for approximate equality may be, for example, a difference between the two equals being less than or equal to 5% of either one.

[0065] It should be understood that when a layer or element is referred to as being on another layer or substrate, it can mean that the layer or element is directly on the other layer or substrate, or that there is an intermediate layer between the layer or element and the other layer or substrate.

[0066] This document describes exemplary embodiments with reference to cross-sectional views and / or plan views, which are idealized exemplary drawings. In the drawings, the thickness of layers and the area of ​​regions are enlarged for clarity. Therefore, variations in shape relative to the drawings are contemplated due to, for example, manufacturing techniques and / or tolerances. Thus, exemplary embodiments should not be construed as being limited to the shapes of the regions shown herein, but rather include shape deviations due to, for example, manufacturing processes. For example, etched areas shown as rectangular would typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to show the actual shapes of the areas of the device, nor are they intended to limit the scope of the exemplary embodiments.

[0067] It should be noted that, for example, 11-1 in the accompanying drawings of this disclosure indicates that component 11 belongs to component 1; for example, 194-19B in Figure 16 indicates that the ninth functional layer 194 belongs to the fourth functional unit 19B; other similar reference numerals in the accompanying drawings also follow the above description. For example, 1 / 2 in the accompanying drawings of this disclosure indicates that both component 1 and component 2 can refer to this component; for example, 101 / 100 in Figure 3 indicates that both the first light-emitting device 101 and the light-emitting device 100 can be represented by this component. Other similar reference numerals in the accompanying drawings also follow the above description.

[0068] As shown in FIG1, some embodiments of the present disclosure provide a display device 300, which includes a display substrate 200.

[0069] The aforementioned display device 300 may be, for example, an OLED (Organic Light Emitting Diode) display device 300.

[0070] As exemplarily shown in FIG1, the display device 300 further includes a driver chip 310. The driver chip 310 is used to drive the display substrate 200 to perform display.

[0071] In addition, the display device 300 may also include an under-display camera and an under-display fingerprint sensor, enabling the display device 300 to perform various functions such as taking photos, recording videos, fingerprint recognition, or facial recognition.

[0072] The aforementioned display device 300 can be any display device that displays either moving (e.g., video) or stationary (e.g., still image) text or images. More specifically, the display device 300 of the described embodiment is contemplated for implementation in or associated with a variety of electronic devices, such as (but not limited to) mobile phones, wireless devices, personal data assistants (PDAs), handheld or portable computers, GPS receivers / navigators, cameras, MP4 video players, camcorders, game consoles, watches, clocks, calculators, television monitors, flat panel displays, computer monitors, automotive displays (e.g., odometer displays, etc.), navigators, cockpit controllers and / or displays, displays of camera views (e.g., displays of rearview cameras in vehicles), electronic photographs, electronic billboards or signs, projectors, architectural structures, packaging and aesthetic structures (e.g., displays of images of a piece of jewelry), etc.

[0073] In some embodiments, as shown in FIG2, the display substrate 200 includes a substrate 210 and a light-emitting functional layer 220 disposed on the substrate 210, the light-emitting functional layer 220 including a plurality of light-emitting devices 100.

[0074] For example, a plurality of light-emitting devices 100 may be arranged along a second direction Y, which is, for example, a direction parallel to the plane where the substrate 210 is located.

[0075] For example, the material of the substrate 210 can be a transparent rigid material, such as glass, to realize a rigid substrate display; or the material of the substrate 210 can also be a transparent flexible material, such as polyimide, to realize a flexible substrate display.

[0076] In some examples, as shown in FIG2, the display substrate 200 further includes an array layer 230 disposed between the substrate 210 and the light-emitting functional layer 220. The array layer 230 includes a plurality of pixel driving circuits 231, wherein the pixel driving circuit 231 includes a plurality of transistor TFTs. Each pixel driving circuit 231 is electrically connected to a light-emitting device 100 for driving the light-emitting device 100 to emit light.

[0077] For example, in the display substrate 200, the pixel driving circuit 231 can generate a driving current. Each light-emitting device 100 can emit light under the driving action of the driving current generated by the corresponding pixel driving circuit 231. The light emitted by multiple light-emitting devices 100 cooperates with each other, thereby enabling the display substrate 200 to realize the display function.

[0078] In some examples, as shown in FIG2, the display substrate 200 further includes an encapsulation layer 240; in this case, the array layer 230, the light-emitting functional layer 220 and the encapsulation layer 240 are stacked on the substrate 210, and the array layer 230, the light-emitting functional layer 220 and the encapsulation layer 240 are arranged sequentially in a direction away from the substrate 210.

[0079] For example, the display substrate 200 can be an OLED display substrate 200. In this case, the encapsulation layer 240 covers the light-emitting device 100 and encapsulates the light-emitting device 100 to prevent moisture and oxygen from the external environment from entering the display substrate 200 and damaging the organic materials in the light-emitting device 100, thereby shortening the lifespan of the OLED display substrate 200.

[0080] In some embodiments, as shown in FIG2 and FIG3, the light-emitting functional layer 220 in the display substrate 200 further includes a pixel defining layer 221, the pixel defining layer 221 having a plurality of openings Q, and a plurality of light-emitting devices 100 can be configured one-to-one with the plurality of openings Q.

[0081] In some embodiments, as shown in Figures 3 and 4, the plurality of light-emitting devices 100 of the display substrate 200 include at least one first light-emitting device 101, at least one second light-emitting device 102, and at least one third light-emitting device 103. Under the action of a driving voltage, the first light-emitting device 101 is configured to emit a first color light, the second light-emitting device 102 is configured to emit a second color light, and the third light-emitting device 103 is configured to emit a third color light.

[0082] The first color light, the second color light, and the third color light are all different. Thus, by setting up multiple light-emitting devices 100, including at least one first light-emitting device 101, at least one second light-emitting device 102, and at least one third light-emitting device 103, the brightness (grayscale) of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 can be adjusted respectively. Through color combination and superposition, multiple colors can be displayed, thereby realizing the full-color display of the display substrate 200.

[0083] For example, the wavelength of the second color light is greater than the wavelength of the first color light; the wavelength of the third color light is greater than the wavelength of the second color light. For instance, the first color light is blue light; the second color light is green light; and the third color light is red light.

[0084] It should be noted that Figures 4 to 16 are simplified schematic diagrams obtained after removing the film layers other than the film layers related to the light-emitting device 100 from the display substrate 200.

[0085] In some embodiments, as shown in Figures 2 to 8, the light-emitting device 100 includes an anode 11 and a cathode 12 disposed opposite to each other along a first direction X, and at least one light-emitting unit 13 disposed between the anode 11 and the cathode 12. The light-emitting unit 13 includes a light-emitting layer 131.

[0086] Based on the above structure, the light-emitting principle of the light-emitting device 100 is as follows: Through a circuit (e.g., pixel driving circuit 231) connecting the anode 11 and the cathode 12, holes are injected into the light-emitting layer 131 by the anode 11, and electrons are injected into the light-emitting layer 131 by the cathode 12. The injected electrons and holes form excitons (i.e., electron-hole pairs) in the light-emitting layer 131. The excitons then undergo radiative transitions back to the ground state, emitting photons. Therefore, in the light-emitting process of the light-emitting device 100, efficient charge generation, effective charge injection, and rapid charge transport are all indispensable. The aforementioned charges are holes or electrons.

[0087] In some examples, as shown in Figure 3, the anode 11 may be located on the side of the light-emitting unit 13 closer to the substrate 210, and the cathode 12 may be located on the side of the light-emitting unit 13 away from the substrate 210. In other examples, the anode 11 may be located on the side of the light-emitting unit 13 away from the substrate 210, and the cathode 12 may be located on the side of the light-emitting unit 13 closer to the substrate 210.

[0088] For example, to ensure that the light-emitting device 100 can emit light effectively, the anode 11 can be made of a material with a high work function. This allows holes in the anode 11 to migrate effectively to the light-emitting layer 131 of the light-emitting unit 13 under the drive of the electric field, thereby recombineing with electrons from the cathode 12 to emit light. The material of the anode 11 can be a transparent conductive metal oxide material, such as indium tin oxide (ITO) or indium zinc oxide (IZO). Alternatively, the anode 11 can be a composite electrode containing multiple materials, such as ITO / Ag / ITO, Ag / IZO, CNT / ITO, CNT / IZO, GO / ITO, or GO / IZO, where Ag is silver, CNT is carbon nanotube, and GO is graphene oxide.

[0089] In some examples, the cathode 12 can be made of a material with a low work function, which makes it easier for electrons from the cathode 12 to be injected into the target film layer (e.g., electron injection layer 1331; for an introduction to electron injection layer 1331, please refer to the following content, which will not be repeated here). This allows electrons in the cathode 12 to effectively migrate to the light-emitting layer 131 of the light-emitting unit 13 under the drive of the electric field, thereby recombineing with holes in the anode 11 to emit light. Furthermore, the cathode 12 must also have good light transmittance and conductivity. The material of the cathode 12 can be a metal, metal oxide, or metal alloy, such as aluminum (Al), silver (Ag), gold (Au), magnesium (Mg), calcium (Ca), ytterbium (Yb), indium (In), lithium (Li), potassium (K), sodium (Na), tin (Sn), titanium (Ti), lead (Pb), samarium (Sm), yttrium (Y), indium tin oxide (ITO), magnesium-silver alloy (Mg:Ag), ytterbium-gold alloy (Yb:Au), and ytterbium-silver alloy. The cathode 12 can be made of materials such as (Yb:Ag), lithium aluminum alloy (Li:Al), or lithium calcium magnesium alloy (Li:Ca:Al); or, the cathode 12 can be made of a multilayer material, such as magnesium / aluminum (Mg / Al), magnesium / silver (Mg / Ag), aluminum / silver (Al / Ag), aluminum / gold (Al / Au), ytterbium / gold (Yb / Au), ytterbium / silver (Yb / Ag), calcium / magnesium (Ca / Mg), calcium / silver (Ca / Ag), barium / silver (Ba / Ag), etc.

[0090] In some embodiments, a capping layer (not shown) is further provided between the encapsulation layer 240 and the cathode 12 in the display substrate 200. The material forming the capping layer is, for example, a material with a high refractive index (e.g., a small organic molecule material). By providing the capping layer, the high refractive properties of the material can be utilized to improve the light extraction efficiency of the light-emitting device 100, thereby improving the efficiency and brightness of the light-emitting device 100 when lit.

[0091] For example, the thickness of the cover layer can be 5nm to 80nm, such as 5nm, 20nm, 35nm, 55nm, 70nm, or 80nm.

[0092] For example, the material of the coating layer has a refractive index greater than or equal to 1.8 at a wavelength of 460 nm, such as 1.8, 2.0, 2.2, 2.5, 3.0, etc.

[0093] In some examples, as shown in Figures 2-4, the light-emitting device 100 includes a single light-emitting unit 13. In this case, the light-emitting device 100 is a single-layer light-emitting device, with the anode 11, the light-emitting unit 13, and the cathode 12 stacked along a first direction X, which intersects with a second direction Y. In other examples, as shown in Figures 5-8, the light-emitting device 100 includes multiple (e.g., two) stacked light-emitting units 13. In this case, the light-emitting device 100 is a multilayer light-emitting device, with the anode 11, multiple light-emitting units 13, and the cathode 12 stacked along the first direction X.

[0094] For example, as shown in Figures 2 to 8, the second direction Y is set perpendicular to the first direction X.

[0095] In some embodiments, as shown in Figures 5 to 8, when the light-emitting device 100 includes a plurality of light-emitting units 13, that is, when the light-emitting device 100 includes at least two light-emitting units 13, the light-emitting device 100 further includes a charge-generating unit 14, which is located between two adjacent light-emitting units 13 among the plurality of light-emitting units 13.

[0096] Through the aforementioned charge generation unit 14, multiple light-emitting units 13 can be sequentially connected in the vertical direction (e.g., the first direction X) of the light-emitting surface. Furthermore, the charge generation unit 14 in the stacked OLED light-emitting device 100 not only serves to connect the light-emitting units 13, but also helps to improve the generation efficiency of charges (holes or electrons), thus significantly impacting the performance of the light-emitting device 100. In addition, when the charge generation unit 14 has high transmittance in the visible light range, the luminous efficiency of the light-emitting device 100 can be improved.

[0097] In some examples, as shown in Figures 5 to 8, the charge generation unit 14 includes an electron generation layer 141 and a hole generation layer 142 stacked together; the electron generation layer 141 is closer to the anode 11 than the hole generation layer 142.

[0098] For example, the electron generating layer 141 described above can also be referred to as an N-type charge generating layer NCGL. The thickness of the electron generating layer 141 can be 15 nm to 25 nm. The material of the electron generating layer 141 can be an electronic material, such as an electronic material containing phenanthroline or phosphoxy groups. In some examples, the electron generating layer 141 contains a dopant, which can be any one or a combination of alkali metals, alkaline earth metals, alkali metal oxides, and alkaline earth metal oxides. Among them, alkali metals are, for example, lithium (Li), sodium (Na), potassium (K), or cesium (Cs), and alkaline earth metals are, for example, magnesium (Mg), strontium (Sr), barium (Ba), or radium (Ra). The material of the electron generating layer 141 may also include ytterbium (Yb). For example, the material of the electron generating layer 141 can include a material with the structure shown in the following formula.

[0099] For example, the hole generation layer 142 described above can also be referred to as a P-type charge generation layer PCGL. The thickness of the hole generation layer 142 can be 5 nm to 15 nm. The material of the hole generation layer 142 can be a hole-type material, such as N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine (NPB) or N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD), etc. In some examples, the hole generation layer 142 contains a dopant, such as 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazabenzophenanthrene (HATCN) or 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanodimethyl-p-benzoquinone (F4TCNQ), etc. For example, the material of the hole-generating layer 142 may include a material with a structure as shown in the following three formulas; wherein the material represented by the third structure belongs to the triaxial compound class.

[0100] In some embodiments, as shown in Figures 3 to 8, to improve the luminous efficiency of the light-emitting device 100, the light-emitting unit 13 further includes a hole transport functional layer 132, located on the side of the light-emitting layer 131 near the anode 11 and in contact with the light-emitting layer 131. The hole transport functional layer 132 includes, for example, at least one of a hole injection layer 1321 (HIL), a hole transport layer 1322 (HTL), and an electron blocking layer 1323 (EBL) stacked together. When the hole transport functional layer 132 includes a hole injection layer 1321, a hole transport layer 1322, and an electron blocking layer 1323, the hole injection layer 1321, the hole transport layer 1322, and the electron blocking layer 1323 are arranged sequentially in a direction away from the anode 11, and the electron blocking layer 1323 is in contact with the light-emitting layer 131.

[0101] In some embodiments, as shown in Figures 3 to 8, to improve the luminous efficiency of the light-emitting device 100, the light-emitting unit 13 further includes an electron transport functional layer 133, located on the side of the light-emitting layer 131 near the cathode 12 and in contact with the light-emitting layer 131. The electron transport functional layer 133 may include, for example, at least one of a stacked electron injection layer 1331 (EIL), an electron transport layer 1332 (ETL), and a hole blocking layer 1333 (EBL). When the electron transport functional layer 133 includes an electron injection layer 1331, an electron transport layer 1332, and a hole blocking layer 1333, the electron injection layer 1331, the electron transport layer 1332, and the hole blocking layer 1333 are arranged sequentially in a direction away from the cathode 12, and the hole blocking layer 1333 is in contact with the light-emitting layer 131.

[0102] By setting up the hole injection layer 1321, hole transport layer 1322, electron blocking layer 1323, electron injection layer 1331, electron transport layer 1332, and hole blocking layer 1333, it is equivalent to setting up transition steps between the anode 11 and the light-emitting layer 131, and between the cathode 12 and the light-emitting layer 131, reducing the potential barrier height that carrier transitions need to overcome, and thus making the luminous efficiency higher.

[0103] For example, the hole transport layer 132 can be configured to transport holes and / or block electrons and excitons generated within the light-emitting layer 131. For instance, the hole injection layer 1321 can be configured to reduce the hole injection barrier and improve hole injection efficiency. The hole transport layer 1322 can be configured to transport holes. The electron blocking layer 1323 can be configured to transport holes, block electrons, and block excitons generated within the light-emitting layer 131; for example, the electron blocking layer 1323 can confine excitons within the light-emitting layer 131, preventing exciton leakage to both sides of the light-emitting layer 131 and thus preventing efficiency loss.

[0104] For example, the electron transport functional layer 133 may be configured to transport electrons and / or block holes and excitons generated within the light-emitting layer 131.

[0105] For example, the material of the hole injection layer 1321 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, or manganese oxide; or, the material of the hole injection layer 1321 can also be a dopant containing a strong electron-withdrawing material, such as 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanodimethyl-p-benzoquinone (F4TCNQ) or 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12 - Hexaazabenzanphenanthrene (HATCN)pyrazolo[2,3-F][1,10]phenanthroline-2,3-dianitronitrile (PPDN); or, the material of the hole injection layer 1321 can also be a material obtained by p-type doping of the material of the hole transport layer 1322, in which case the thickness of the hole injection layer 1321 can be 5nm to 20nm; the process of forming the hole injection layer 1321 is, for example, by co-evaporating the material of the hole transport layer 1322 with the p-type dopant. The structural formulas of F4TCNQ, HATCN and PPDN are shown in the following formulas.

[0106] For example, the material of the hole transport layer 1322 has good hole transport characteristics and can be an aromatic amine material or a carbazole material, such as N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine (NPB), 4,4',4”-tris(carbazole-9-yl)triphenylamine (TCTA), 4,4'-cyclohexylbis[N,N-di(4-methylphenyl)aniline] (TAPC), N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD), (9-phenylfluorene-9-yl)triphenylamine (BAFLP), or bis[n-(9,9-dimethylfluorene-2-yl)-n-phenylamino]biphenyl (DFLDPBi), etc. The structural formulas of NPB, TCTA, and TAPC are shown below.

[0107] For example, the electron blocking layer 1323 can also be called the light-emitting auxiliary layer. Its material has good hole transport characteristics and can be an aromatic amine material or a carbazole material, such as 4,4'-bis(9-carbazole)biphenyl (CBP) or 9-phenyl-3-[4-(10-phenyl-9-anthrayl)phenyl]-9h-carbazole (PCzPA), etc.

[0108] For example, the material of the electron injection layer 1331 can be an alkali metal or a metal, such as lithium fluoride (LiF), ytterbium (Yb), magnesium (Mg), calcium (Ca), or a compound of the above metals.

[0109] For example, the materials of the electron transport layer 1332 and the hole blocking layer 1333 can be aromatic heterocyclic compounds, such as imidazole derivatives, pyrimidine derivatives, azine derivatives, compounds containing a nitrogen-containing six-membered ring structure, or compounds having phosphine oxide substituents on the heterocycle. Among these, imidazole derivatives are, for example, benzimidazole derivatives, imidazopyridine derivatives, or benzimidazolephenanthridine derivatives; azine derivatives are, for example, triazine derivatives; and compounds containing a nitrogen-containing six-membered ring structure are, for example, quinoline derivatives, isoquinoline derivatives, or phenanthreneroline derivatives. In some examples, the electron transport layer 1332 and the hole blocking layer 1333 are made of materials such as 2,2'-(1,3-phenyl)bis[5-(4-tert-butylphenyl)-1,3,4-oxadiazole] (OXD-7), 3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole (TAZ), 3-(4-tert-butylphenyl)-4-(4-ethylphenyl)-5-(4-biphenyl)-1,2,4-triazole (p-EtTAZ), 4,7-diphenyl-1,10-phenanthroline (BPhen), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), or 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBi), etc. For example, the material of the electron transport layer 1332 may include a material with a structure as shown in the following three formulas.

[0110] In some embodiments, as shown in Figures 2, 3, 5, and 7, when the plurality of light-emitting devices 100 include a first light-emitting device 101, a second light-emitting device 102, and a third light-emitting device 103, the cathodes 12 of the plurality of light-emitting devices 100 are in a fully interconnected structure, that is, the cathode 12 can be a common electrode shared by the plurality of light-emitting devices 100. The hole injection layer 1321 of the plurality of light-emitting devices 100 can also be in a fully interconnected structure, that is, the hole injection layer 1321 can be a common film layer shared by the plurality of light-emitting devices 100. The hole transport layer 1322, the electron blocking layer 1323, the electron injection layer 1331, the electron transport layer 1332, the hole blocking layer 1333, the electron generation layer 141, and the hole generation layer 142 can also be common film layers shared by the plurality of light-emitting devices 100, which will not be described in detail here.

[0111] For example, as shown in FIG3, when the cathode 12 is a common electrode shared by multiple light-emitting devices 100, the cathode 12 is simultaneously formed on the side of the pixel defining layer 221 away from the substrate 210.

[0112] In some embodiments, as shown in Figures 3-5 and 7, when multiple light-emitting devices 100 include a first light-emitting device 101, a second light-emitting device 102, and a third light-emitting device 103, the electron blocking layers 1323 of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 are independently disposed; that is, the electron blocking layer 1323 may include a blue electron blocking layer 1323B, a green electron blocking layer 1323G, and a red electron blocking layer 1323R. With this arrangement, the material of the electron blocking layer 1323 with matching performance can be selected as needed, depending on the material of the light-emitting layer 131.

[0113] For example, when the light-emitting device 100 is a single-layer light-emitting device, the structure of the light-emitting device 100 (e.g., the first light-emitting device 101) is as shown in FIG4. The light-emitting device 100 includes an anode 11, a hole injection layer 1321, a hole transport layer 1322, an electron blocking layer 1323, a light-emitting layer 131, a hole blocking layer 1333, an electron transport layer 1332, an electron injection layer 1331, and a cathode 12 stacked together.

[0114] For example, when the light-emitting device 100 is a stacked light-emitting device (e.g., containing two light-emitting units 13), the structure of the light-emitting device 100 (e.g., the first light-emitting device 101) is as shown in Figures 6 and 8. The light-emitting device 100 includes a stacked anode 11, a hole transport functional layer 132, a light-emitting layer 131, an electron transport functional layer 133, an electron generation layer 141, a hole generation layer 142, a hole transport functional layer 132, a light-emitting layer 131, an electron transport functional layer 133, and a cathode 12. Among them, the hole transport functional layer 132, the light-emitting layer 131, and the electron transport functional layer 133 located near the anode 11 constitute the first light-emitting unit 13, and the hole transport functional layer 132, the light-emitting layer 131, and the electron transport functional layer 133 located near the cathode 12 constitute the second light-emitting unit 13.

[0115] For example, when the light-emitting device 100 is a stacked light-emitting device (e.g., including two light-emitting units 13), and the multiple light-emitting devices 100 include a first light-emitting device 101, a second light-emitting device 102, and a third light-emitting device 103, the structure of the display substrate 200 is as shown in Figures 5 and 7, for example. The cathode 12 is the common electrode of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103; the hole transport functional layers 132 of the first light-emitting unit 13 and the second light-emitting unit 13, excluding the electron blocking layer 1323, and the respective electron transport functional layers 133 of the first light-emitting unit 13 and the second light-emitting unit 13 are common film layers shared by the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103. The anode 11 of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103, the electron blocking layer 1323 of the first light-emitting unit 13, and the light-emitting layer 131 of the second light-emitting unit 13 are independently disposed. For information on how to set it up independently, please refer to the above content; it will not be repeated here.

[0116] For example, in the above-described stacked light-emitting device, as shown in Figures 5 to 8, the hole transport functional layer 132 of the first light-emitting unit 13 closer to the anode 11 may include a hole injection layer 1321, a hole transport layer 1322, and an electron blocking layer 1323. The hole transport functional layer 132 of the second light-emitting unit 13 closer to the cathode 12 may include a hole transport layer 1322 and an electron blocking layer 1323.

[0117] For example, in the above-described stacked light-emitting device, as shown in Figures 5 and 6, the electron transport functional layer 133 of the first light-emitting unit 13 closer to the anode 11 may include a hole blocking layer 1333. Alternatively, as shown in Figures 7 and 8, the electron transport functional layer 133 of the first light-emitting unit 13 may include a hole blocking layer 1333 and an electron transport layer 1332.

[0118] For example, in the above-mentioned stacked light-emitting device, as shown in Figures 5 to 8, the electron transport functional layer 133 of the second light-emitting unit 13 closer to the cathode 12 may include a hole blocking layer 1333, an electron transport layer 1332, and an electron injection layer 1331.

[0119] In the above-mentioned stacked light-emitting device containing two light-emitting units 13, the electron generating layer 141 can inject electrons into the first light-emitting unit 13, and the hole generating layer 142 can inject holes into the second light-emitting unit 13.

[0120] In some embodiments, the material of the light-emitting layer 131 includes a host material and a guest material.

[0121] For example, the host material can be configured to: transport holes or electrons, and / or, recombine electrons with holes to form excitons and transfer exciton energy to the guest material.

[0122] For example, the guest material can be configured to: emit photons using exciton energy transferred from the host material, and / or, recombine electrons and holes to form excitons and emit photons.

[0123] In some examples, the guest material is a fluorescent material, which can emit light using singlet excitons; in other examples, the guest material is a phosphorescent material or a delayed fluorescence material, which can emit light using triplet excitons.

[0124] In some examples, the host material includes two or more materials. For example, the host material may include a first host material and a second host material, wherein the first host material is a hole-type material and the second host material is an electronic-type material.

[0125] For example, when multiple light-emitting devices 100 include a first light-emitting device 101 for emitting blue light, the host material of the light-emitting layer 131 of the first light-emitting device 101 can be at least one material containing anthracene, and the guest material can be a fluorescent dopant. Moreover, when the host material includes two materials, the two materials can be isomers, homologues, or excitocomposites.

[0126] In this case, the host material of the first light-emitting device 101 may include anthracene derivatives, such as 9,10-bis(2-naphthyl)anthracene (ADN) or 2-methyl-9,10-dinaphthylanthracene (MADN); the guest material of the first light-emitting device 101 may include pyrene derivatives, fluorene derivatives, perylene derivatives, styrylamine derivatives, or metal complexes, such as 2,5,8,11-tetra-tert-butylperylene (TBPe), 4,4'-bis[4-(diphenylamino)styryl]biphenyl (BDAVBi), 4,4'-bis[4-(di-p-tolylamino)styryl]biphenyl (DPAVBi), or bis(4,6-difluorophenylpyridine-C2,N)pyridinecarboxyiridium (FIrpic), etc. The structural formulas of ADN and DPAVBi are shown below.

[0127] In some examples, the light-emitting layer 131 of the first light-emitting device 101 is a single-layer structure; in other examples, the light-emitting layer 131 of the first light-emitting device 101 is a stacked structure. Moreover, when the light-emitting layer 131 of the first light-emitting device 101 is a stacked structure, the material of each film layer in the stacked structure includes a host material and a guest material. Furthermore, in different stacks, the host material may be the same or different; the guest material may be the same or different.

[0128] For example, when multiple light-emitting devices 100 include a second light-emitting device 102, and the second light-emitting device 102 is used to emit green light, the host material of the light-emitting layer 131 of the second light-emitting device 102 can be an excimer compound, and the guest material can be a phosphorescent dopant.

[0129] In this case, the host material of the second light-emitting device 102 may include coumarin dyes, quinacridone copper derivatives, polycyclic aromatic hydrocarbons, diamine anthracene derivatives, or carbazole derivatives, such as N,N'-dimethylquinacridone (DMQA), N,N'-di-1-naphthyl-N,N'-diphenyl-[9,9'-bianthra]-10,10'-diamine; N1,N1'-diphenyl-N1,N1'-dinaphthyl-9,9'-bianthra-1,1'-diamine (BA-NPB), 8-hydroxyquinoline aluminum (Alq3), or 4,4'-di(9-carbazolyl)biphenyl (CPB), etc.; the guest material of the second light-emitting device 102 may include metal complexes, such as tri(2-phenylpyridine)iridium (Ir(ppy)3) or di(2-phenylpyridine)iridium acetylacetonate (Ir(ppy)2(acac)), etc. The structural formulas of CPB and Ir(ppy)3 are shown below.

[0130] For example, when multiple light-emitting devices 100 include a third light-emitting device 103, which is used to emit red light, the host material of the light-emitting layer 131 of the third light-emitting device 103 can be an excimer compound, and the guest material can be a phosphorescent dopant.

[0131] In this case, the main material of the third light-emitting device 103 may include DCM series materials, such as 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM), 4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulonidin-9-enyl)-4H-pyran (DCJTB), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinazin-9-yl)vinyl] =-4H-pyran-4-ylidene malononitrile (DCJTI) or 2,8-bis(9H-carbazole-9-yl)dibenzo[b,d]thiophene (DCzDBT), etc.; the guest material of the third light-emitting device 103 may include metal complexes, such as bis(1-phenyl-isoquinoline)(acetylacetone)iridium(III) (Ir(piq)2(acac)), platinum(II)octaethylporphyrin (PtOEP) or bis(2-(2'-benzothiophene)pyridine-N,C3')(acetylacetone)iridium(Ir(btp)2(acac)), etc. The structural formulas of DCzDBT and Ir(piq)2(acac) are shown below.

[0132] As mentioned in the background, in the field of organic semiconductors, OLED light-emitting devices have advantages such as self-illumination, wide viewing angle, high contrast, fast response speed, wide operating temperature range, and the ability to be fabricated into flexible products. Moreover, compared to liquid crystal displays (LCDs), OLED display substrates containing OLED light-emitting devices also have the advantages of not requiring a backlight, thinner panel, and lighter weight. Therefore, OLED display substrates have been successfully applied in commercial flat panel displays, lighting systems, communication systems, automotive display systems, portable electronic devices, and high-definition display devices.

[0133] To achieve higher device efficiency (e.g., current efficiency), the structure of OLED light-emitting devices has evolved from the initial sandwich structure to a stacked structure. A traditional single-layer light-emitting device structure, as shown in Figure 9, includes an anode 11, a hole transport layer 1322, an emissive layer 131, an electron transport layer 1332, and a cathode 12 stacked sequentially; wherein the hole transport layer 1322, the emissive layer 131, and the electron transport layer 1332 constitute an OLED light-emitting unit. As shown in Figure 10, a stacked light-emitting device structure includes, in sequence, an anode 11, a hole transport layer 1322, a light-emitting layer 131, an electron transport layer 1332, a charge generation unit 14, and a cathode 12. The hole transport layer 1322, the light-emitting layer 131, and the electron transport layer 1332 near the anode 11 constitute one OLED light-emitting unit, while the hole transport layer 1322, the light-emitting layer 131, and the electron transport layer 1332 near the cathode 12 constitute another OLED light-emitting unit. The two OLED light-emitting units 13 are connected together through the charge generation unit 14. For descriptions of single-layer and stacked light-emitting device structures, please refer to the preceding content; they will not be repeated here.

[0134] Based on the above structure, stacked OLED light-emitting devices can achieve superior device performance compared to traditional single-layer OLED light-emitting devices, such as higher efficiency and longer lifespan, giving them broad application prospects. Specifically, firstly, since OLEDs emit light through current, under the same current density, the luminous intensity of a stacked OLED light-emitting device 100 composed of n identical light-emitting units 13 is n times that of a traditional OLED light-emitting device 100 composed of a single light-emitting unit 13. Therefore, the current efficiency of the stacked OLED light-emitting device 100 is n times that of the traditional OLED light-emitting device 100. Secondly, OLED displays and lighting devices operate at a certain brightness. Under the same luminous intensity, the current density driving the stacked OLED light-emitting device 100 is 1 / n of the current density driving the traditional OLED light-emitting device 100. Since a higher current density drives the OLED light-emitting device 100, the faster the OLED light-emitting device 100 ages and the shorter its lifespan, the lifespan of the stacked OLED light-emitting device 100 is extended. Therefore, the stacked OLED light-emitting device 100 plays an important role in the fields of OLED display and lighting.

[0135] With the development of stacked OLED light-emitting devices, the performance requirements for efficiency, lifespan, and other aspects of these devices are becoming increasingly stringent. The efficiency and lifespan of stacked OLED light-emitting devices are not only related to the optimized combination of organic materials contained in the structure of the light-emitting device 100 and its various film layers (including those in the light-emitting unit and the charge-generating unit), but also to the thickness of each film layer. By adjusting the thicknesses of the film layers in the light-emitting unit 13 and the charge-generating unit 14 to a suitable range, matching the thicknesses of the film layers in the light-emitting unit 13 and the charge-generating unit 14, the emitted light can be directed to points of enhanced interference, thereby improving the light extraction efficiency of the stacked OLED light-emitting device.

[0136] Based on this, some embodiments of this disclosure provide a display substrate 200, as shown in Figures 11-14. The display substrate 200 includes a substrate 210 (see Figure 3) and a first light-emitting device 101, a second light-emitting device 102, and a third light-emitting device 103 disposed on the substrate 210. The first light-emitting device 101 emits a first color light. The second light-emitting device 102 emits a second color light; the wavelength of the second color light is greater than the wavelength of the first color light. The third light-emitting device 103 emits a third color light; the wavelength of the third color light is greater than the wavelength of the second color light. Each of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 includes a first electrode 15, a second electrode 16, a first light-emitting unit 13A, a second light-emitting unit 13B, and a charge-generating unit 14. The first electrode 15 and the second electrode 16 are disposed opposite each other along a first direction X, with the second electrode 16 being closer to the substrate 210 than the first electrode 15. The first light-emitting unit 13A and the second light-emitting unit 13B are located between the first electrode 15 and the second electrode 16, and are stacked along the first direction X; the second light-emitting unit 13B is further away from the first electrode 15 relative to the first light-emitting unit 13A. A charge-generating unit 14 is located between the first light-emitting unit 13A and the second light-emitting unit 13B. The charge-generating unit 14 includes a first charge-generating layer 143 and a second charge-generating layer 144 stacked along the first direction X, the second charge-generating layer 144 being further away from the first electrode 15 relative to the first charge-generating layer 143.

[0137] The surface of the first electrode 15 near the first light-emitting unit 13A has a first distance from the surface of the first charge-generating layer 143 away from the first light-emitting unit 13A; the first distance L corresponding to the third light-emitting device 103 is... 13 The first distance L corresponding to the first light-emitting device 101 11 There is a first difference (L) between them 13 -L 11The first distance L corresponding to the second light-emitting device 12 The first distance L corresponding to the first light-emitting device 11 There is a second difference (L) between them 12 -L 11 ); First difference (L) 13 -L 11 ) and the second difference (L) 12 -L 11 The ratio between (hereinafter referred to as the first ratio) is in the range of 1.8 to 2.5.

[0138] That is, the first distance L corresponding to the first light-emitting device 101 11 The first distance L corresponding to the second light-emitting device 102 12 and the first distance L corresponding to the third light-emitting device 103 13 The following conditions must be met:

[0139] For example, the first ratio can be 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4 or 2.5, etc.

[0140] Here, the description of the first light-emitting device 101, the second light-emitting device 102, the third light-emitting device 103, and the charge generating unit 14 can be found in the foregoing exemplary description of the first light-emitting device 101, the second light-emitting device 102, the third light-emitting device 103, and the charge generating unit 14, and will not be repeated here.

[0141] In some examples, the first electrode 15 is the cathode and the second electrode 16 is the anode; in this case, the first charge generation layer 143 can be a hole generation layer and the second charge generation layer 144 can be an electron generation layer. In other examples, the first electrode 15 is the anode and the second electrode 16 is the cathode; in this case, the first charge generation layer 143 can be an electron generation layer and the second charge generation layer 144 can be a hole generation layer. For a description of the anode, cathode, hole generation layer, and electron generation layer, please refer to the foregoing exemplary descriptions of the anode, cathode, hole generation layer, and electron generation layer; these will not be repeated here.

[0142] In some examples, the first charge generation layer 143 is a hole generation layer PCGL, and the size of the first charge generation layer 143 along the first direction X is 5nm to 15nm; for example, 5nm, 7nm, 9nm, 11nm, 12nm, 13nm or 15nm, etc.

[0143] In some examples, the second charge generation layer 144 is an electron generation layer NCGL, and the size of the second charge generation layer 144 along the first direction X is 15nm to 25nm; for example, 15nm, 17nm, 19nm, 20nm, 21nm, 23nm or 25nm, etc.

[0144] In some examples, the size of the second electrode 16 along the first direction X is 10nm to 20nm; for example, 10nm, 12nm, 14nm, 15nm, 16nm, 18nm or 20nm, etc.

[0145] In some examples, the display substrate 200 is a single-sided light-emitting display panel, and its light-emitting side and non-light-emitting side are arranged along the first direction X; in this case, the first electrode 15 may be closer to the light-emitting side of the display substrate 200 relative to the second electrode 16; or, the second electrode 16 may be closer to the light-emitting side of the display substrate 200 relative to the first electrode 15.

[0146] In other examples, the display substrate 200 is a dual-sided light-emitting display panel, and its two light-emitting sides are arranged along the first direction X; in this case, the first electrode 15 may be closer to one light-emitting side of the display substrate 200 relative to the second electrode 16; the second electrode 16 may be closer to the other light-emitting side of the display substrate 200 relative to the first electrode 15.

[0147] Here, the first distance is the distance between the surface of the first electrode 15 near the first light-emitting unit 13A and the surface of the first charge-generating layer 143 away from the first light-emitting unit 13A. It should be understood that when the first electrode 15 is in contact with the first light-emitting unit 13A and the first light-emitting unit 13A is in contact with the first charge-generating layer 143, the first distance is the sum of the thicknesses of the first light-emitting unit 13A and the first charge-generating layer 143. It can also be understood as the total thickness of the organic film layer near the first electrode 15 in the light-emitting device 100.

[0148] It should be understood that when the wavelength of the first color light is shorter than the wavelength of the second color light, and the wavelength of the second color light is shorter than the wavelength of the third color light, the wavelengths of the first color light, the second color light, and the third color light are all different.

[0149] Understandably, a microcavity structure can be formed between the first electrode 15 and the second electrode 16 of the light-emitting device 100. When the light-emitting regions of the first light-emitting unit 13A and / or the second light-emitting unit 13B are located in the microcavity enhancement region, a strong microcavity effect can be formed, thereby improving the light extraction efficiency of the light-emitting device 100. Moreover, the position of the microcavity enhancement region is related to the wavelength of the light emitted by the corresponding light-emitting device 100. Therefore, when the wavelengths of the first color light, the second color light, and the third color light are different, the distances between the microcavity enhancement region in the first light-emitting device 101, the microcavity enhancement region in the second light-emitting device 102, and the microcavity enhancement region in the third light-emitting device 103 and the first electrode 15 are all different. Therefore, by setting the first ratio in the range of 1.8 to 2.5, the thicknesses of the first light-emitting unit 13A in the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 and the first charge-generating layer 143 can be different, and the distances between the light-emitting areas of the first light-emitting unit 13A in the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 and the first electrode 15 can be different. In this way, the light-emitting area of ​​the first light-emitting unit 13A in the first light-emitting device 101 can be located in the microcavity enhancement region of the first light-emitting device 101, the light-emitting area of ​​the first light-emitting unit 13A in the second light-emitting device 102 can be located in the microcavity enhancement region of the second light-emitting device 102, and the light-emitting area of ​​the first light-emitting unit 13A in the third light-emitting device 103 can be located in the microcavity enhancement region of the third light-emitting device 103. This can form a strong microcavity effect, optimize the spectrum emitted by the display substrate 200, and improve the light extraction efficiency of the display substrate 200.

[0150] In some embodiments, as shown in Figures 11-14, a second distance exists between the surface of the second electrode 16 near the second light-emitting unit 144 and the surface of the second charge-generating layer 144 away from the second light-emitting unit 13B. The second distance L corresponding to the third light-emitting device 103 is... 23 The second distance L corresponding to the second light-emitting device 102 22 There is a third difference (L) between them 23 -L 22 The second distance L corresponding to the second light-emitting device 102 22 The second distance L corresponding to the first light-emitting device 101 21 There is a fourth difference (L) between them 22 -L 21 The ratio between the third and fourth differences (hereinafter referred to as the second ratio) ranges from 1.0 to 1.5.

[0151] That is, the second distance L corresponding to the first light-emitting device 10121 The second distance L corresponding to the second light-emitting device 102 22 The second distance L corresponding to the third light-emitting device 103 23 The following conditions must be met:

[0152] For example, the second ratio can be 1.0, 1.1, 1.2, 1.3, 1.4 or 1.5, etc.

[0153] Here, the second distance is the distance between the surface of the second electrode 16 near the second light-emitting unit 13B and the surface of the second charge-generating layer 144 away from the second light-emitting unit 13B. It should be understood that when the second electrode 16 is in contact with the second light-emitting unit 13B and the second light-emitting unit 13B is in contact with the second charge-generating layer 144, the second distance is the sum of the thicknesses of the second light-emitting unit 13B and the second charge-generating layer 144. It can also be understood that the second distance is the total thickness of the organic film layer near the second electrode 16 in the light-emitting device 100.

[0154] Understandably, by setting the second ratio to a range of 1.0 to 1.5, the thicknesses of the second light-emitting units 13B in the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 and the second charge-generating layer 144 can be different, and the distances between the light-emitting areas of the second light-emitting units 13B in the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 and the second electrode 16 can be different. In this way, the light-emitting area of ​​the second light-emitting unit 13B in the first light-emitting device 101 can be located in the microcavity enhancement region of the first light-emitting device 101, the light-emitting area of ​​the second light-emitting unit 13B in the second light-emitting device 102 can be located in the microcavity enhancement region of the second light-emitting device 102, and the light-emitting area of ​​the second light-emitting unit 13B in the third light-emitting device 103 can be located in the microcavity enhancement region of the third light-emitting device 103. This can form a strong microcavity effect, optimize the spectrum emitted by the display substrate 200, and improve the light extraction efficiency of the display substrate 200.

[0155] In some embodiments, as shown in Figures 11 to 14, the first distance L in the first light-emitting device 101 11 Distance L from the second point 21 The ratio between them ranges from 0.65 to 0.90.

[0156] That is, the first distance L corresponding to the first light-emitting device 101 11 The second distance L corresponding to the first light-emitting device 101 21 The following conditions must be met:

[0157] For example, in the first light-emitting device 101, the first distance L 11 Distance L from the second point 21 The ratios between them are 0.65, 0.70, 0.75, 0.80, 0.86, or 0.90, etc.

[0158] Understandably, when the first distance L in the first light-emitting device 101 11 Distance L from the second point 21 When the ratio between them is in the range of 0.65 to 0.90, the light-emitting area of ​​the first light-emitting unit 13A in the first light-emitting device 101 is located in the microcavity enhancement region near the first electrode 15, and the light-emitting area of ​​the second light-emitting unit 13B is located in the microcavity enhancement region near the second electrode 16. In this way, the light extraction efficiency of the first light-emitting device 101 can be improved.

[0159] In some embodiments, as shown in Figures 11-14, the first distance L in the second light-emitting device 102 is... 12 Distance L from the second point 22 The ratio between them ranges from 0.60 to 0.85.

[0160] That is, the first distance L corresponding to the second light-emitting device 102 12 The second distance L corresponding to the second light-emitting device 102 22 The following conditions must be met:

[0161] For example, the first distance L in the second light-emitting device 102 12 Distance L from the second point 22 The ratios between them are 0.60, 0.70, 0.75, 0.80, 0.83, or 0.85, etc.

[0162] Understandably, when the first distance L in the second light-emitting device 102 12 Distance L from the second point 22 When the ratio between them is in the range of 0.60 to 0.85, the light-emitting area of ​​the first light-emitting unit 13A in the second light-emitting device 102 is located in the microcavity enhancement region near the first electrode 15, and the light-emitting area of ​​the second light-emitting unit 13B is located in the microcavity enhancement region near the second electrode 16. In this way, the light extraction efficiency of the second light-emitting device 102 can be improved.

[0163] In some embodiments, as shown in Figures 11-14, the first distance L in the third light-emitting device 103 13 Distance L from the second point 23 The ratio between them ranges from 0.50 to 0.80.

[0164] That is, the first distance L corresponding to the third light-emitting device 103 13The second distance L corresponding to the third light-emitting device 103 23 The following conditions must be met:

[0165] For example, in the third light-emitting device 103, the first distance L 13 Distance L from the second point 23 The ratios between them are 0.50, 0.55, 0.60, 0.65, 0.70, 0.72, 0.75, or 0.80, etc.

[0166] Understandably, when the ratio between the first distance L13 and the second distance L23 in the third light-emitting device 103 is in the range of 0.50 to 0.80, the light-emitting area of ​​the first light-emitting unit 13A in the third light-emitting device 103 can be located in the microcavity enhancement region near the first electrode 15, and the light-emitting area of ​​the second light-emitting unit 13B can be located in the microcavity enhancement region near the second electrode 16. In this way, the light extraction efficiency of the third light-emitting device 103 can be improved.

[0167] In some embodiments, as shown in Figures 11 to 14, the second distance L in the first light-emitting device 101 21 The range is That is to say,

[0168] For example, the second distance L in the first light-emitting device 101 21 for or wait.

[0169] Understandably, when the second distance L 21 The range is In this way, the sum of the thicknesses of the second light-emitting unit 13B and the second charge-generating layer 144 in the first light-emitting device 101 can be within a suitable range, so that the light-emitting area of ​​the second light-emitting unit 13B in the first light-emitting device 101 is located in the microcavity enhancement region, and the light emitted by the second light-emitting unit 13B is at the point of interference enhancement. In this way, the light emission efficiency of the first light-emitting device 101 can be improved.

[0170] In some embodiments, as shown in Figures 11-14, the second distance L in the second light-emitting device 102 22 The range is That is to say,

[0171] For example, the second distance L in the second light-emitting device 102 22 for or wait.

[0172] Understandably, when the second distance L 22The range is In this way, the sum of the thicknesses of the second light-emitting unit 13B and the second charge-generating layer 144 in the second light-emitting device 102 can be within a suitable range, so that the light-emitting area of ​​the second light-emitting unit 13B in the second light-emitting device 102 is located in the microcavity enhancement region, and the light emitted by the second light-emitting unit 13B is at the point of interference enhancement. In this way, the light emission efficiency of the second light-emitting device 102 can be improved.

[0173] In some embodiments, as shown in Figures 11-14, the second distance L in the third light-emitting device 103 23 The range is That is to say,

[0174] For example, the second distance L in the third light-emitting device 103 23 for or wait.

[0175] Understandably, when the second distance L 23 The range is In this way, the sum of the thicknesses of the second light-emitting unit 13B and the second charge-generating layer 144 in the third light-emitting device 103 can be within a suitable range, so that the light-emitting area of ​​the second light-emitting unit 13B in the third light-emitting device 103 is located in the microcavity enhancement region, and the light emitted by the second light-emitting unit 13B is at the point of interference enhancement. In this way, the light emission efficiency of the third light-emitting device 103 can be improved.

[0176] In some embodiments, as shown in Figures 11-14, in the first light-emitting device 101, the first light-emitting unit 13A includes a first light-emitting layer 1311A; the second light-emitting unit 13B includes a second light-emitting layer 1311B. In the second light-emitting device 102, the first light-emitting unit 13A includes a third light-emitting layer 1312A; the second light-emitting unit 13B includes a fourth light-emitting layer 1312B. In the third light-emitting device 103, the first light-emitting unit 13A includes a fifth light-emitting layer 1313A; the second light-emitting unit 13B includes a sixth light-emitting layer 1313B. The fifth light-emitting layer 1313A has a dimension L along the first direction X. 331 The dimension L of the first light-emitting layer 1311A along the first direction X 311 There is a fifth difference (L) between them 331 -L 311 The third light-emitting layer 1312A has a dimension L along the first direction X. 321 The dimension L of the first light-emitting layer 1311A along the first direction X 311 There is a sixth difference (L) between them 321 -L 311 ); Fifth difference (L) 331 -L311 ) and the sixth difference (L) 321 -L 311 The ratio between (hereinafter referred to as the third ratio) is in the range of 0.8 to 3.0.

[0177] That is, the size L of the first light-emitting layer 1311A along the first direction X 311 The third light-emitting layer 1312A has a dimension L along the first direction X. 321 The fifth light-emitting layer 1313A along the first direction X has a dimension L. 331 The following conditions must be met:

[0178] For example, the third ratio can be 0.8, 1.3, 1.8, 2.3, 2.7 or 3.0, etc.

[0179] Optionally, the third ratio can be 1.0, i.e. In this case, the dimension L of the third light-emitting layer 1312A along the first direction X is... 321 It can be equal to the size L of the fifth light-emitting layer 1313A along the first direction X. 331 .

[0180] Understandably, when the third ratio is in the range of 0.8 to 3.0, the light-emitting region of the first light-emitting unit 13A in the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 can be located in the microcavity enhancement region, forming a strong microcavity effect and improving the light extraction efficiency of the display substrate 200. Furthermore, when the third ratio is in the range of 0.8 to 3.0, the region of hole-electron recombination in the first light-emitting unit 13A in the first light-emitting device 101 can be located in the first light-emitting layer 1311A, the region of hole-electron recombination in the first light-emitting unit 13A in the second light-emitting device 102 can be located in the third light-emitting layer 1312A, and the region of hole-electron recombination in the first light-emitting unit 13A in the third light-emitting device 103 can be located in the fifth light-emitting layer 1313A. This improves exciton utilization and enhances the light-emitting efficiency of the display substrate 200.

[0181] In some embodiments, as shown in Figures 11 to 14, the sixth light-emitting layer 1313B has a dimension L along the first direction X. 332 The dimension L of the second light-emitting layer 1311B along the first direction X 312 There is a seventh difference (L) between them 332 -L 312 The fourth light-emitting layer 1312B has a dimension L along the first direction. 322 The dimension L of the second light-emitting layer 1311B along the first direction X 312 There is an eighth difference (L) between them 322 -L312 ); Seventh difference (L) 332 -L 312 The difference between the eighth and eighth values ​​(L) 322 -L 312 The ratio between (hereinafter referred to as the fourth ratio) ranges from 0.8 to 3.0.

[0182] That is, the second light-emitting layer 1311B has a dimension L along the first direction X. 312 The fourth light-emitting layer 1312B has a dimension L along the first direction. 322 And the sixth light-emitting layer 1313B along the first direction X, dimension L 332 The following conditions must be met:

[0183] For example, the fourth ratio can be 0.8, 1.3, 1.8, 2.1, 2.5 or 3.0, etc.

[0184] Optionally, the fourth ratio can be 1.0, i.e. In this case, the fourth light-emitting layer 1312B has a dimension L along the first direction. 322 It can be equal to the size L of the sixth light-emitting layer 1313B along the first direction X. 332 .

[0185] Understandably, when the fourth ratio is in the range of 0.8 to 3.0, the light-emitting regions of the second light-emitting units 13B in the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 can be located in the microcavity enhancement region, forming a strong microcavity effect and improving the light extraction efficiency of the display substrate 200. Furthermore, when the fourth ratio is in the range of 0.8 to 3.0, the region of hole-electron recombination in the second light-emitting unit 13B of the first light-emitting device 101 can be located in the second light-emitting layer 1311B, the region of hole-electron recombination in the second light-emitting unit 13B of the second light-emitting device 102 can be located in the fourth light-emitting layer 1312B, and the region of hole-electron recombination in the second light-emitting unit 13B of the third light-emitting device 103 can be located in the sixth light-emitting layer 1313B. This improves exciton utilization and enhances the luminous efficiency of the display substrate 200.

[0186] In some embodiments, as shown in Figures 11-14, the first light-emitting unit 13A further includes a first functional unit 17 located between the first type of light-emitting layer and the charge-generating unit 14. The first type of light-emitting layer is a first light-emitting layer 1311A, a third light-emitting layer 1312A, or a fifth light-emitting layer 1313A. The first functional unit 17 includes a first functional layer 171. The second light-emitting unit 13B further includes a second functional unit 18 located between the second type of light-emitting layer and the second electrode 16. The second type of light-emitting layer is a second light-emitting layer 1311B, a fourth light-emitting layer 1312B, or a sixth light-emitting layer 1313B. The second functional unit 18 includes a third functional layer 181, a fourth functional layer 182, and a fifth functional layer 183 arranged sequentially along the direction close to the second electrode 16.

[0187] It should be understood that when the first functional unit 17 is located between the first type of light-emitting layer and the charge-generating unit 14, the first functional unit 17 can transfer the charge carriers injected or generated by the charge-generating unit 14; when the second functional unit 18 is located between the second type of light-emitting layer and the second electrode 16, the second functional unit 18 can transfer the charge carriers generated by the second electrode 16; here, the charge carriers are electrons or holes.

[0188] In some examples, as shown in Figures 7 and 11-14, the first electrode 15 is the cathode and the second electrode 16 is the anode. In this case, the first functional unit 17 is the hole transport functional layer 132 in the first light-emitting unit 13A; and the second functional unit 18 is the hole transport functional layer 132 in the second light-emitting unit 13B. In this case, the first functional layer 171 can be the electron blocking layer 1323 of the first light-emitting unit 13A, the third functional layer 181 can be the electron blocking layer 1323 of the second light-emitting unit 13B, the fourth functional layer 182 can be the hole transport layer 1322 of the second light-emitting unit 13B, and the fifth functional layer 183 can be the hole injection layer 1321 of the second light-emitting unit 13B.

[0189] In other examples, as shown in Figures 7 and 11-14, the first electrode 15 is the anode and the second electrode 16 is the cathode. In this case, the first functional unit 17 is the electron transport functional layer 133 in the first light-emitting unit 13A; and the second functional unit 18 is the electron transport functional layer 133 in the second light-emitting unit 13B. In this case, the first functional layer 171 can be the hole blocking layer 1333 of the first light-emitting unit 13A, the third functional layer 181 can be the hole blocking layer 1333 of the second light-emitting unit 13B, the fourth functional layer 182 can be the electron transport layer 1332 of the second light-emitting unit 13B, and the fifth functional layer 183 can be the electron injection layer 1331 of the second light-emitting unit 13B.

[0190] In some examples, the first functional layer 171 of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 is independently configured. In this case, the size of the first functional layer 171 in the first light-emitting device 101 along the first direction X can be 5nm to 15nm; for example, 5nm, 7nm, 9nm, 11nm, 13nm, or 15nm. The size of the first functional layer 171 in the second light-emitting device 102 along the first direction X can be 10nm to 25nm; for example, 10nm, 13nm, 16nm, 19nm, 22nm, or 25nm. The size of the first functional layer 171 in the third light-emitting device 103 along the first direction X can be 20nm to 45nm; for example, 20nm, 25nm, 30nm, 32nm, 35nm, 40nm, or 45nm.

[0191] In some examples, the third functional layer 181 in the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 is independently configured. In this case, the size of the third functional layer 181 in the first light-emitting device 101 along the first direction X can be 5nm to 15nm; for example, 5nm, 7nm, 9nm, 11nm, 13nm, or 15nm. The size of the third functional layer 181 in the second light-emitting device 102 along the first direction X can be 20nm to 50nm; for example, 20nm, 25nm, 30nm, 35nm, 46nm, or 50nm. The size of the third functional layer 181 in the third light-emitting device 103 along the first direction X can be 60nm to 100nm; for example, 60nm, 70nm, 74nm, 80nm, 90nm, or 100nm.

[0192] In some examples, the fourth functional layer 182 has a size of 80nm to 120nm along the first direction X; for example, 80nm, 90nm, 96nm, 100nm, 110nm or 120nm.

[0193] In some examples, the fifth functional layer 183 has a size of 5nm to 30nm along the first direction X; for example, 5nm, 10nm, 15nm, 18nm, 20nm, 25nm or 30nm, etc.

[0194] For a description of the hole injection layer 1321, hole transport layer 1322, electron blocking layer 1323, electron injection layer 1331, electron transport layer 1332, and hole blocking layer 1333, please refer to the foregoing exemplary description of the hole injection layer 1321, hole transport layer 1322, electron blocking layer 1323, electron injection layer 1331, electron transport layer 1332, and hole blocking layer 1333, which will not be repeated here.

[0195] In some examples, the size of the first light-emitting layer 1311A along the first direction X is 10nm to 40nm; for example, 10nm, 15nm, 20nm, 22nm, 25nm, 30nm or 40nm, etc.

[0196] In some examples, the size of the second light-emitting layer 1311B along the first direction X is 10nm to 40nm; for example, 10nm, 15nm, 18nm, 20nm, 25nm, 30nm or 40nm, etc.

[0197] In some examples, the size of the third light-emitting layer 1312A along the first direction X is 20nm to 50nm; for example, 20nm, 25nm, 28nm, 30nm, 35nm, 40nm or 50nm, etc.

[0198] In some examples, the size of the fourth light-emitting layer 1312B along the first direction X is 20nm to 50nm; for example, 20nm, 25nm, 30nm, 33nm, 35nm, 40nm or 50nm, etc.

[0199] In some examples, the fifth light-emitting layer 1313A has a size of 30nm to 60nm along the first direction X; for example, 30nm, 35nm, 38nm, 40nm, 45nm, 50nm or 60nm, etc.

[0200] In some examples, the size of the sixth light-emitting layer 1313B along the first direction X is 30nm to 60nm; for example, 30nm, 35nm, 40nm, 45nm, 48nm, 50nm or 60nm, etc.

[0201] Understandably, through the above configuration, the first functional unit 17 can be used to improve the carrier transport performance of the first light-emitting unit 13A, thereby achieving efficient charge generation, effective charge injection, and rapid charge transport in the first light-emitting unit 13A; the second functional unit 18 can be used to improve the carrier transport performance of the second light-emitting unit 13B, thereby achieving efficient charge generation, effective charge injection, and rapid charge transport in the second light-emitting unit 13B.

[0202] In some embodiments, as shown in Figures 11 to 14, the first functional unit 17 further includes a second functional layer 172, which is located between the first functional layer 171 and the charge generation unit 14.

[0203] In some examples, as shown in Figures 7 and 11-14, the first electrode 15 is the cathode and the second electrode 16 is the anode. In this case, the second functional layer 172 can be the hole transport layer 1322 of the first light-emitting unit 13A.

[0204] In other examples, as shown in Figures 7 and 11-14, the first electrode 15 is the anode and the second electrode 16 is the cathode. In this case, the second functional layer 172 can be the electron transport layer 1332 of the first light-emitting unit 13A.

[0205] In some examples, the size of the second functional layer 172 along the first direction X is 30nm to 70nm; for example, 30nm, 40nm, 50nm, 55nm, 60nm or 70nm, etc.

[0206] Understandably, the above settings can improve the carrier transport performance of the first light-emitting unit 13A, and achieve efficient charge generation, effective charge injection, and rapid charge transport in the first light-emitting unit 13A.

[0207] In some embodiments, as shown in Figures 11 to 14, in the same light-emitting device 100, the third functional layer 181 has a dimension L along the first direction X. 42 The dimension L of the first functional layer 171 along the first direction X is greater than or equal to the dimension L of the first functional layer 171. 41 The light-emitting device 100 is any one of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103. That is: L 42 ≥L 41 .

[0208] In some examples, the third functional layer 181 and the first functional layer 171 are common film layers shared by the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103. In this case, the dimensions of the third functional layer 181 of the first light-emitting device 101 along the first direction X, the dimensions of the third functional layer 181 of the second light-emitting device 102 along the first direction X, and the dimensions of the third functional layer 181 of the third light-emitting device 103 along the first direction X can be equal, for example, all being L. 42 The dimensions of the first functional layer 171 of the first light-emitting device 101 along the first direction X, the dimensions of the first functional layer 171 of the second light-emitting device 102 along the first direction X, and the dimensions of the first functional layer 171 of the third light-emitting device 10 along the first direction X can be equal, for example, all being L. 41 Moreover, L 42 ≥L 41 .

[0209] In other examples, as shown in Figure 11, the third functional layer 181 of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 is independently configured; the first functional layer 171 of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 is independently configured; in this case, the third functional layer 181 of the first light-emitting device 101 has a dimension L along the first direction X. 421The third functional layer 181 of the second light-emitting device 102 has a dimension L along the first direction X. 422 and the third functional layer 181 of the third light-emitting device 10 along the first direction X, with a dimension L 423 They can be different; the first functional layer 171 of the first light-emitting device 101 has a size L along the first direction X. 411 The first functional layer 171 of the second light-emitting device 102 has a dimension L along the first direction X. 412 and the first functional layer 171 of the third light-emitting device 10 along the first direction X, with a dimension L 413 They can vary; moreover, these dimensions satisfy the following: L 421 ≥L 411 L 422 ≥L 412 L 423 ≥L 413 .

[0210] When the third functional layer 181 of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 are independently configured, and the first functional layer 171 of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 are independently configured, the first functional layer 171 can be, for example, the electron blocking layer of the first light-emitting unit 13A; the third functional layer 181 can be, for example, the electron blocking layer of the second light-emitting unit 13B; here, the description of the electron blocking layer can be referred to the foregoing exemplary description of the electron blocking layer, and will not be repeated here.

[0211] Understandably, firstly, through the above-mentioned arrangement, the light-emitting regions of the first light-emitting unit 13A and the second light-emitting unit 13B in the light-emitting device 100 can be located in the microcavity enhancement region, which can form a strong microcavity effect and improve the light extraction efficiency of the display substrate 200; secondly, compared with the charge carriers (e.g., holes or electrons) generated or injected by the first charge generation layer 143, the second electrode 16 generates more charge carriers, that is, the amount of charge carriers transferred by the second functional unit 18 is greater than or equal to the amount of charge carriers transferred by the first functional unit 17; in this case, through the above-mentioned arrangement, the size of the second functional unit 18 along the first direction X can be larger. The dimensions of the second functional unit 18 and the first functional unit 17 along the first direction X are equal to or greater than the dimensions of the first functional unit 17 along the first direction X. This allows the dimensions of the second functional unit 18 and the first functional unit 17 along the first direction X to be matched with the amount of charge carriers they transmit. This allows the hole-electron recombination region in the first light-emitting unit 13A of the light-emitting device 100 to be located in the first light-emitting layer 1311A, the third light-emitting layer 1312A, or the fifth light-emitting layer 1313A. Similarly, the hole-electron recombination region in the second light-emitting unit 13B of the light-emitting device 100 to be located in the second light-emitting layer 1311B, the fourth light-emitting layer 1312B, or the sixth light-emitting layer 1313B. This can improve exciton utilization and increase the luminous efficiency of the display substrate 200.

[0212] In some embodiments, as shown in Figures 11 to 14, in the same light-emitting device 100, the fourth functional layer 182 has a dimension L along the first direction X. 52 The dimension L of the second functional layer 172 along the first direction X 51 The ratio between them ranges from 1.5 to 2.5; the light-emitting device 100 is any one of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103. That is, 1.5 ≤ L 52 / L 51 ≤2.5.

[0213] In some examples, as shown in Figure 11, the fourth functional layer 182 and the second functional layer 172 are common film layers shared by the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103. In this case, the dimensions of the fourth functional layer 182 of the first light-emitting device 101 along the first direction X, the dimensions of the fourth functional layer 182 of the second light-emitting device 102 along the first direction X, and the dimensions of the fourth functional layer 182 of the third light-emitting device 103 along the first direction X can be equal, for example, all being L. 52 The dimensions of the second functional layer 172 of the first light-emitting device 101 along the first direction X, the dimensions of the second functional layer 172 of the second light-emitting device 102 along the first direction X, and the dimensions of the second functional layer 172 of the third light-emitting device 10 along the first direction X can be equal, for example, all being L. 51Moreover, 1.5≤L 52 / L 51 ≤2.5. At this time, the second functional layer 172 can be, for example, the hole transport layer of the first light-emitting unit 13A; the fourth functional layer 182 can be, for example, the hole transport layer of the second light-emitting unit 13B; here, the description of the hole transport layer can be referred to the foregoing exemplary description of the hole transport layer, and will not be repeated here.

[0214] In other examples, the fourth functional layer 182 of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 are independently configured; the second functional layer 172 of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 are independently configured; in this case, in the first light-emitting device 101, the ratio between the dimension of the fourth functional layer 182 along the first direction X and the dimension of the second functional layer 172 along the first direction X ranges from 1.5 to 2.5; in the second light-emitting device 102, the ratio between the dimension of the fourth functional layer 182 along the first direction X and the dimension of the second functional layer 172 along the first direction X ranges from 1.5 to 2.5; in the third light-emitting device 103, the ratio between the dimension of the fourth functional layer 182 along the first direction X and the dimension of the second functional layer 172 along the first direction X ranges from 1.5 to 2.5.

[0215] Understandably, firstly, through the above-mentioned configuration, the light-emitting regions of the first light-emitting unit 13A and the second light-emitting unit 13B in the light-emitting device 100 can be located in the microcavity enhancement region, which can form a strong microcavity effect and improve the light extraction efficiency of the display substrate 200. Secondly, the size of the second functional unit 18 along the first direction X can be greater than or equal to the size of the first functional unit 17 along the first direction X. In this way, the sizes of the second functional unit 18 and the first functional unit 17 along the first direction X can be matched with the amount of charge carriers they transmit. The hole-electron recombination region in the first light-emitting unit 13A in the light-emitting device 100 can be located in the first light-emitting layer 1311A, the third light-emitting layer 1312A, or the fifth light-emitting layer 1313A; and the hole-electron recombination region in the second light-emitting unit 13B in the light-emitting device 100 can be located in the second light-emitting layer 1311B, the fourth light-emitting layer 1312B, or the sixth light-emitting layer 1313B. This can improve the exciton utilization rate and improve the light extraction efficiency of the display substrate 200.

[0216] In some embodiments, as shown in Figures 11-14, the material of the first charge generation layer 143 includes a first host material H1 and a first dopant material G1. The first host material H1 is a hole-type material. The first dopant material G1 is configured to p-type dope the first host material H1. The mass percentage of the first dopant material G1 in the material of the first charge generation layer 143 is less than the mass percentage of the first host material H1 in the material of the first charge generation layer 143.

[0217] It should be understood that when the first main material H1 is a hole-generating material, the first charge-generating layer 143 can be a hole-generating layer. In this case, the second electrode 16 is the anode and the first electrode 15 is the cathode. Here, the description of the hole-generating layer can be referred to the aforementioned exemplary description of the hole-generating layer, and will not be repeated here.

[0218] Understandably, when the first doping material G1 performs P-type doping on the first host material H1, the hole injection capability of the material of the first charge generation layer 143 can be improved by using the first doping material G1. In this way, holes can be effectively injected into the first light-emitting unit 13A by using the first charge generation layer 143, which can increase the hole injection amount in the first light-emitting unit 13A, which is beneficial to improving the exciton recombination rate and thus improving the luminous efficiency of the display substrate 200.

[0219] In some embodiments, as shown in Figures 11-14, the material of the fifth functional layer 183 includes a first host material H1 and a first dopant material G1. The first host material H1 is a hole transport material. The first dopant material G1 is configured to p-type dope the first host material H1. The mass percentage of the first dopant material G1 in the material of the fifth functional layer 183 is less than the mass percentage of the first host material H1 in the material of the fifth functional layer 183.

[0220] It should be understood that when the first host material H1 is a hole-type material, the fifth functional layer 183 can be a hole injection layer. In this case, the second electrode 16 is the anode and the first electrode 15 is the cathode. Here, the description of the hole injection layer can be referred to the foregoing exemplary description of the hole injection layer, and will not be repeated here.

[0221] Understandably, when the first doping material G1 performs P-type doping on the first host material H1, the hole injection capability of the fifth functional layer 183 can be improved by using the first doping material G1. In this way, the fifth functional layer 183 can be used to effectively inject holes into the second light-emitting unit 13B, thereby increasing the hole injection amount in the second light-emitting unit 13B, which is beneficial to improving the exciton recombination rate and thus improving the luminous efficiency of the display substrate 200.

[0222] For example, in the first charge generating layer 143 or the fifth functional layer 183, the material of the first host material H1 can be N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine (NPB) or N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD), etc.

[0223] In some examples, the first host material H1 and the first doped material G1 can be co-evaporated to form the first charge generation layer 143 or the fifth functional layer 183.

[0224] It should be noted that when both the materials of the first charge generation layer 143 and the fifth functional layer 183 include the first host material H1 and the first dopant material G1, the first host material H1 of the first charge generation layer 143 and the first host material H1 of the fifth functional layer 183 may be the same or different; there are no restrictions here.

[0225] In some embodiments, the first doped material G1 is selected from any of the structures shown in the following general formula (I).

[0226] Where A is any one of the three-membered ring, four-membered ring, five-membered ring and six-membered ring.

[0227] R1, R2, R3, R4, R5, and R6 may be the same or different, and are independently selected from any one of halogen, cyano, substituted aryl, and substituted or unsubstituted heteroaryl; and, in the case where R1, R2, R3, R4, R5, or R6 is a substituted aryl, the substituent of the aryl includes at least one electron-withdrawing group.

[0228] Here, A can be a carbon ring or a carbon heterocycle containing carbon atoms and heteroatoms; for example, when A is a three-membered ring, A can be a three-membered carbon ring or a carbon heterocycle containing carbon atoms and heteroatoms (e.g., nitrogen N, silicon Si or germanium Ge).

[0229] It should be noted that when A is a four-membered ring, a five-membered ring, or a six-membered ring, as shown in general formula (I), three atoms in the ring are connected to double bonds; there are no restrictions on the connecting bonds and connecting groups of atoms in other rings that are not connected to double bonds. For example, atoms in other rings that are not connected to double bonds can be connected to double bonds or single bonds.

[0230] Here, when R1, R2, R3, R4, R5, or R6 is a substituted aryl group, the substituent of the aryl group includes at least one electron-withdrawing group. The type and number of electron-withdrawing groups are not limited here; for example, the electron-withdrawing group can be a cyano (-CN), a halogen (-F, -Cl, -Br, or -I), or a trifluoromethyl (-CF3), etc. When R1, R2, R3, R4, R5, or R6 is a substituted heteroaryl group, the type and number of substituents are not limited here.

[0231] Understandably, through the above configuration, the structure shown in general formula (I) contains electron-withdrawing groups, and the structure shown in general formula (I) contains an A ring and multiple double bonds connected thereto, which can form a conjugated system. In this way, the electron-withdrawing ability of the first doped material G1 can be improved, the conductivity of the first doped material G1 can be enhanced, and the hole injection performance of the first charge generation layer 143 or the fifth functional layer 183 can be improved. This is beneficial to the effective generation, injection and transport of charges, and can improve the luminous efficiency of the display substrate 200.

[0232] In some examples, when R1, R2, R3, R4, R5, and R6 are all phenyl groups substituted with electron-withdrawing groups, the structural formula of the first dopant G1 can be as shown below.

[0233] In some embodiments, at least one of R1, R2, R3, R4, R5, and R6 is a cyano group.

[0234] Understandably, cyano groups have a strong electron-withdrawing ability. When at least one of R1, R2, R3, R4, R5, and R6 is a cyano group, the electron-withdrawing ability of the first dopant material G1 can be enhanced. In this way, the conductivity of the first dopant material G1 can be enhanced, and the hole injection performance of the first charge generation layer 143 or the fifth functional layer 183 can be improved.

[0235] In some examples, when there are two cyano groups in R1, R2, R3, R4, R5, and R6, the structure of the first doped material G1 can be as shown in the following formula.

[0236] In some examples, when there are three cyano groups in R1, R2, R3, R4, R5, and R6, the structure of the first doped material G1 can be as shown in the following formula.

[0237] It should be noted that the structural formulas listed above are examples of the structure of the first doped material G1, and are not a limitation on the first doped material G1. Moreover, (G1-x) in the above structural formulas is a suffix for each structural formula, and is not part of the structural formula, where x takes a positive integer.

[0238] In some embodiments, the first doped material G1 is selected from any of the structures shown in the following general formula (II).

[0239] Where X1 and X2 are the same or different, and are independently selected from C(R) a ), N and Si(R) b Any one of the following. Where C(R) a ) is R a Substituted carbon, N is nitrogen, Si(R) b ) is R b Replacement silicon.

[0240] Y1 and Y2 may be the same or different, and are independently selected from N(R). c Any one of N(R), O, and S. Where N(R) c ) is R c The nitrogen is replaced by oxygen (O) and sulfur (S).

[0241] Ar1, Ar2, Ar3, and Ar4 may be the same or different, and are independently selected from any one of halogen, cyano, substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted fluorenyl, substituted or unsubstituted adamantyl, and substituted or unsubstituted heteroaryl; or may be connected to adjacent groups to form substituted or unsubstituted rings.

[0242] R7, R8, R a R b and R c Whether identical or different, each is independently selected from hydrogen, deuterium, halogen, cyano, substituted or unsubstituted C3-C20 heteroaryl, substituted or unsubstituted C6-C20 aryl, substituted or unsubstituted C1-C5 alkyl, substituted or unsubstituted C1-C10 haloalkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C2-C10 heterocycloalkyl, substituted or unsubstituted C1-C10 alkoxy, substituted or unsubstituted C1-C10 alkylthio, substituted or unsubstituted C6-C18 aryloxy, substituted or unsubstituted C6-C18 arylthio, substituted or unsubstituted C6-C24 phosphoxy, and substituted or unsubstituted C6-C18 alkylsulfonyl.

[0243] m and n may be the same or different, and are independently selected from 1, 2, 3, 4 and 5 respectively.

[0244] Here, Cx refers to an alkyl group containing x carbon (C) atoms, where x is a positive integer, and the same applies below. For the understanding of other groups such as Cx aryl and Cx heteroaryl, please refer to the above content, which will not be repeated here. Furthermore, phenyl refers to the group remaining after removing a hydrogen atom from one carbon atom of the benzene ring. For the understanding of other groups such as aryl, heteroaryl, and alkyl, please refer to the above content, which will not be repeated here.

[0245] In the structure shown in general formula (II), (R x ) y It refers to the substituent R x The quantity is y. When y is 0, it means that all the carbon atoms with substitution sites on the corresponding six-membered ring have been replaced by hydrogen atoms. When y is a positive integer greater than or equal to 1, it means that there are y R atoms connected to the corresponding six-membered ring. x Moreover, y R x It can be attached to any y substituted carbons among the six carbons on a six-membered ring; here, regarding R... x The positions of the connected carbon atoms are not restricted here. When y is a positive integer greater than 1, there are y R atoms. x They can be the same or different. Here, x is either 7 or 8, and y is either m or n.

[0246] When Ar1, Ar2, Ar3, and Ar4 are selected from any one of substituted phenyl, substituted biphenyl, substituted terphenyl, substituted fluorenyl, substituted adamantyl, and substituted heteroaryl, and / or, L 11 Selected from any one of substituted C3-C30 alkylene groups, substituted C6-C30 arylene groups, and substituted 5- to 30-membered heteroarylene groups, and / or, R7, R8, R a R b and R c When the substituent is selected from any of the following: substituted C3-C20 heteroaryl, substituted C6-C20 aryl, substituted C1-C5 alkyl, substituted C1-C10 haloalkyl, substituted C3-C10 cycloalkyl, substituted C2-C10 heterocycloalkyl, substituted C1-C10 alkoxy, substituted C1-C10 alkylthio, substituted C6-C18 aryloxy, substituted C6-C18 arylthio, substituted C6-C24 phosphoxy, and substituted C6-C18 alkylsulfonyl, there are no restrictions on the type and number of substituents.

[0247] Understandably, the IIA portion in the structure shown in general formula (II), and the substituents Ar1, Ar2, Ar3 and Ar4 connected to the IIA portion, have a certain electron-withdrawing ability; this can improve the electron-withdrawing ability of the first doped material G1; moreover, the IIA portion with a certain electron-withdrawing ability can form a conjugated system with the substituents Ar1, Ar2, Ar3 and Ar4, producing a conjugation effect, which can improve the electron-withdrawing ability of the first doped material G1. Thus, the conductivity of the first doped material G1 can be enhanced, and the hole injection performance of the first charge generation layer 143 or the fifth functional layer 183 can be improved, which is beneficial to the effective generation, injection and transport of charge, and can improve the luminous efficiency of the display substrate 200.

[0248] In some examples, when X1 and X2 are nitrogen and Y1 and Y2 are oxygen, the structure of the first doped material G1 can be as shown in the following formula.

[0249] In some examples, when X1 and X2 are nitrogen and Y1 and Y2 are sulfur, the structure of the first doped material G1 can be as shown in the following formula.

[0250] In some examples, when X1 and X2 are carbon and Y1 and Y2 are oxygen, the structure of the first doped material G1 can be as shown in the following formula.

[0251] In some examples, when X1 and X2 are carbon and Y1 and Y2 are sulfur, the structural formula of the first doped material G1 can be as shown below.

[0252] It should be noted that the structural formulas listed above are examples of the structure of the first doped material G1, and are not a limitation on the first doped material G1. Moreover, (G1-x') in the above structural formulas is a suffix for each structural formula, and is not part of the structural formula, where x takes a positive integer.

[0253] In some embodiments, the mass percentage of the first doped material G1 in the material of the first charge generation layer 143 is greater than or equal to 0.5% and less than or equal to 10%.

[0254] For example, the mass percentage of the first doped material G1 in the material of the first charge generation layer 143 can be 0.5%, 0.8%, 1%, 3%, 4%, 5%, 6%, 7%, 9%, or 10%, etc.

[0255] In some embodiments, the mass percentage of the first doped material G1 in the material of the fifth functional layer 183 is greater than or equal to 0.5% and less than or equal to 10%.

[0256] For example, the mass percentage of the first doped material G1 in the material of the fifth functional layer 183 can be 0.5%, 0.7%, 1%, 3%, 4%, 5%, 6%, 8%, 9%, or 10%, etc.

[0257] Understandably, when the mass percentage of the first doped material G1 in the materials of the first charge generation layer 143 and / or the fifth functional layer 183 is small (e.g., less than 0.5%), the improvement of hole injection performance of the first doped material G1 on the first charge generation layer 143 and / or the fifth functional layer 183 is small; at the same time, it will cause carriers to accumulate at the interface, which will cause the interface material to deteriorate and result in poor lifetime of the light-emitting device 100. In some examples, the first charge generation layer 143 and / or the fifth functional layer 183 are common films shared by the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 (e.g., common films obtained by open mask evaporation). When the mass percentage of the first dopant material G1 in the material of the first charge generation layer 143 and / or the fifth functional layer 183 is large (e.g., greater than 10%), the conductivity of the material of the first charge generation layer 143 and / or the fifth functional layer 183 will be significantly increased, exhibiting characteristics similar to a metallic conductor. This causes current to be transverse to adjacent light-emitting devices 100, resulting in color crosstalk and accompanying light emission, leading to poor color purity of the light emitted by the light-emitting device 100. Therefore, through the above configuration, the mass percentage of the first dopant material G1 in the material of the first charge generation layer 143 and / or the fifth functional layer 183 can be kept within a suitable range, which can improve the hole injection performance of the first charge generation layer 143 and / or the fifth functional layer 183, and at the same time improve the lifetime and color purity of the display substrate 200.

[0258] In some embodiments, the material of the second charge generation layer 144 includes a second host material H2 and a second doped material G2; the mass percentage of the second doped material G2 in the second charge generation layer 144 is less than the mass percentage of the second host material H2. The second host material H2 is selected from any one of the structures shown in the following general formula (III).

[0259] Among them, X3, X4, X5, and X6 may be the same or different, and are independently selected from C(R). d C(R) and N; and at least two of X3, X4, X5, and X6 are N. d ) is for R d Replaced carbon.

[0260] Ar5, Ar6, Ar7, and Ar8 may be the same or different, and are independently selected from hydrogen, deuterium, tritium, halogen, cyano, nitro, substituted or unsubstituted C6–C60 aryl, substituted or unsubstituted C3–C60 alicyclic, substituted or unsubstituted C6–C60 aromatic fused ring, substituted or unsubstituted C1–C50 alkyl, substituted or unsubstituted C2–C20 alkenyl, substituted or unsubstituted C2–C20 alkynyl, substituted or unsubstituted C1–C30 alkoxy, substituted or unsubstituted C6–C30 aryloxy, substituted or unsubstituted C3–C60 alkylsilyl, substituted or unsubstituted C18–C60 arylsilyl, substituted or unsubstituted C8–C60 alkylarylsilyl, and substituted or unsubstituted C2–C60 The heterocyclic group comprises any one of the following: O, N, S, Si, and P. Wherein, O is oxygen, N is nitrogen, S is sulfur, Si is silicon, and P is phosphorus.

[0261] R d It is selected from hydrogen, deuterium, substituted or unsubstituted C1-C60 alkyl, substituted or unsubstituted C2-C60 alkenyl, substituted or unsubstituted C2-C60 alkynyl, substituted or unsubstituted C1-C60 alkoxy, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C1-C10 heterocyclic alkyl, substituted or unsubstituted C3-C10 cycloalkenyl, substituted or unsubstituted C1-C10 heterocyclic alkenyl, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C6-C60 aryloxy, substituted or unsubstituted C6-C60 arylthio, substituted or unsubstituted C1-C60 heteroaryl, substituted or unsubstituted monovalent nonaromatic condensed polycyclic and substituted or unsubstituted monovalent nonaromatic condensed heterocyclic.

[0262] The descriptions of alkyl groups and alkenyl groups of Cx can be found in the above description of alkyl groups of Cx, and will not be repeated here.

[0263] It should be noted that when Ar5, Ar6, Ar7, and Ar8 are selected from any one of the following: substituted C6-C60 aryl, substituted C3-C60 alicyclic, substituted C6-C60 aromatic fused-ring, substituted C1-C50 alkyl, substituted C2-C20 alkenyl, substituted C2-C20 alkynyl, substituted C1-C30 alkoxy, substituted C6-C30 aryloxy, substituted C3-C60 alkylsilyl, substituted C18-C60 arylsilyl, substituted C8-C60 alkylarylsilyl, and substituted C2-C60 heterocyclic, and / or, R dWhen the substituent is selected from any of the following: substituted C1-C60 alkyl, substituted C2-C60 alkenyl, substituted C2-C60 alkynyl, substituted C1-C60 alkoxy, substituted C3-C10 cycloalkyl, substituted C1-C10 heterocyclic alkyl, substituted C3-C10 cycloalkenyl, substituted C1-C10 heterocyclic alkenyl, substituted C6-C60 aryl, substituted C6-C60 aryloxy, substituted C6-C60 arylthio, substituted C1-C60 heteroaryl, substituted monovalent non-aromatic condensed polycyclic, and substituted monovalent non-aromatic condensed heteropolycyclic, no restrictions are placed on the type and number of substituents.

[0264] Understandably, when at least two of X3, X4, X5, and X6 are N, the structure shown in general formula (III) is a heterocyclic compound. Firstly, the heterocyclic compound represented by the structure shown in general formula (III) has a lower lowest unoccupied molecular orbital energy level (which can also be understood as a deeper lowest unoccupied molecular orbital energy level), which can reduce the energy level barrier at the interface between the first charge generation layer 143 and the second charge generation layer 144 (hereinafter referred to as the first interface), reduce the accumulation of charge carriers caused by the energy level barrier at the first interface, and prevent material degradation at the first interface. Thus, the lifetime of the display substrate 200 can be improved. Secondly, the heterocyclic compound represented by the structure shown in general formula (III) has sp2 hybridized nitrogen atoms, which can give the second host material H2 excellent electron transport capabilities. A pin structure is formed between the first charge generation layer 143 and the second charge generation layer 144, generating an electron flow that allows electrons to be rapidly transported to the second light-emitting unit 13B for radiative emission, thereby reducing the driving voltage of the display substrate. Thirdly, the sp2 hybridized nitrogen atoms possess lone pairs of electrons, which can form complexes with the second dopant material (e.g., a metal compound). This can suppress the crystallization of the second host material H2, controlling the crystallization at the interface between the second charge generation layer 144 and the electron transport functional layer of the second light-emitting unit 13B (hereinafter referred to as the second interface), resulting in a more uniform morphology at the second interface. Secondly, it can increase the electron injection capability of the second charge generation layer 144, improving charge flow in the light-emitting device 100 and reducing the driving voltage of the display substrate 200. Therefore, when the second host material H2 is selected from any of the structures shown in general formula (III), the luminous efficiency and lifetime of the display substrate 200 can be improved, and the driving voltage of the display substrate 200 can be reduced.

[0265] It should be understood that when the second host material H2 includes a structure selected from the structure shown in general formula (III), the second charge generating layer 144 can be an electron generating layer. In this case, the second electrode 16 is the anode and the first electrode 15 is the cathode. Here, the description of the electron generating layer can be referred to the foregoing exemplary description of the electron generating layer, and will not be repeated here.

[0266] In some examples, when X3 and X4 are nitrogen, the structural formula of the second host material H2 can be as shown below.

[0267] In some examples, when X5 and X6 are nitrogen, the structural formula of the second host material H2 can be as shown below.

[0268] It should be noted that the structural formulas listed above are examples of the structures of the second host material H2, and are not restrictions on the second host material H2. Moreover, (H2-x) in the above structural formulas is a suffix for each structural formula, and is not part of the structural formula itself, where x takes a positive integer.

[0269] In some embodiments, the second doped material G2 includes one or any combination of alkali metals, alkaline earth metals, transition metals, alkali metal compounds, alkaline earth metal compounds, and transition metal compounds.

[0270] For example, alkali metals include lithium (Li), sodium (Na), potassium (K) or cesium (Cs), and alkaline earth metals include magnesium (Mg), strontium (Sr), barium (Ba) or radium (Ra).

[0271] Understandably, on the one hand, through the above-mentioned configuration, the second doping material G2 can perform N-type doping on the second host material H2, which can improve the electron injection capability of the second charge generation layer 144, improve the charge flow in the light-emitting device 100, and reduce the driving voltage of the display substrate 200; on the other hand, through the above-mentioned configuration, the second doping material G2 can form a complex with the second host material H2, thereby making the morphology at the second interface more uniform and reducing the driving voltage of the display substrate 200.

[0272] In some embodiments, as shown in FIG11, the mass percentage of the second doped material G2 in the material of the second charge generation layer 144 is greater than or equal to 0.5% and less than or equal to 3%.

[0273] For example, the mass percentage of the second doped material G2 in the material of the second charge generation layer 144 can be 0.5%, 0.8%, 1.0%, 1.5%, 2.0%, 2.5%, or 3.0%, etc.

[0274] Understandably, when the mass percentage of the second dopant G2 in the material of the second charge generation layer 144 is small (e.g., less than 0.5%), the improvement in electron injection performance of the second charge generation layer 144 by the second dopant G2 is small; at the same time, it will cause carriers to accumulate at the interface, resulting in the degradation of the interface material and a poor lifetime of the light-emitting device 100. In some examples, the second charge generation layer 144 is a common film layer shared by the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 (e.g., a common film layer obtained by open mask evaporation); when the mass percentage of the second dopant G2 in the material of the second charge generation layer 144 is large (e.g., greater than 3%), the conductivity of the material of the second charge generation layer 144 is greatly improved, exhibiting characteristics similar to a metallic conductor, causing current to be transverse to adjacent light-emitting devices 100, causing color crosstalk, producing accompanying luminescence, and resulting in poor color purity of the light emitted by the light-emitting device 100. Therefore, through the above settings, the mass ratio of the second doped material G2 in the material of the second charge generation layer 144 can be within a suitable range, which can improve the electron injection performance of the second charge generation layer 144, and at the same time improve the lifetime and color purity of the display substrate 200.

[0275] The above is an exemplary description of the material of the charge generation unit 14. The following will exemplarily describe the spectrum of light emitted by the light-emitting layer in the light-emitting device 100, as well as the highest occupied molecular orbital energy level / lowest unoccupied molecular orbital energy level and electron / hole mobility of each film layer. It should be noted that in the following embodiments, the descriptions of the hole injection layer, hole transport layer, electron blocking layer, electron injection layer, electron transport layer, hole blocking layer, hole generation layer, and electron generation layer can refer to the foregoing exemplary descriptions of these layers, and will not be repeated here.

[0276] In some embodiments, as shown in Figures 11 to 14, the wavelength range of the light emitted by the first light-emitting layer 1311A and the second light-emitting layer 1311B is 440nm to 490nm.

[0277] For example, the wavelengths of the light emitted by the first light-emitting layer 1311A and the second light-emitting layer 1311B are 440nm, 450nm, 460nm, 470nm, 472nm, 480nm or 490nm, etc.

[0278] Understandably, through the above configuration, the wavelengths of the light emitted by the first light-emitting layer 1311A and the second light-emitting layer 1311B are closer, that is, the colors of the light emitted by the first light-emitting layer 1311A and the second light-emitting layer 1311B are closer. In this way, the superposition effect of the spectrum of the light emitted by the first light-emitting layer 1311A and the second light-emitting layer 1311B can be improved, so that there is no obvious color difference between the light emitted by the two light-emitting units, and the color purity of the light emitted by the first light-emitting device 101 can be improved.

[0279] In some embodiments, as shown in Figures 11 to 14, the wavelength range of the light emitted by the third light-emitting layer 1312A and the fourth light-emitting layer 1312B is 500nm to 540nm.

[0280] For example, the wavelengths of the light emitted by the third light-emitting layer 1312A and the fourth light-emitting layer 1312B are 500nm, 510nm, 520nm, 526nm, 530nm or 540nm, etc.

[0281] Similarly, by setting it up in this way, the superposition effect of the light spectrum emitted by the third light-emitting layer 1312A and the fourth light-emitting layer 1312B can be improved, so that there is no obvious color difference between the light emitted by the two light-emitting units, and the color purity of the light emitted by the second light-emitting device 102 can be improved.

[0282] In some embodiments, as shown in Figures 11 to 14, the wavelength range of the light emitted by the fifth light-emitting layer 1313A and the sixth light-emitting layer 1313B is 600nm to 650nm.

[0283] For example, the wavelengths of the light emitted by the fifth light-emitting layer 1313A and the sixth light-emitting layer 1313B are 600nm, 610nm, 620nm, 630nm, 634nm, 640nm or 650nm, etc.

[0284] Similarly, by setting it up in this way, the superposition effect of the light spectrum emitted by the fifth light-emitting layer 1313A and the sixth light-emitting layer 1313B can be improved, so that there is no obvious color difference between the light emitted by the two light-emitting units, and the color purity of the light emitted by the third light-emitting device 103 can be improved.

[0285] In some embodiments, as shown in Figures 11 to 14, the ratio between the electron mobility of the material of the second light-emitting layer 1311B and the electron mobility of the material of the first light-emitting layer 1311A ranges from 0.01 to 100; the ratio between the hole mobility of the material of the second light-emitting layer 1311B and the hole mobility of the material of the first light-emitting layer 1311A ranges from 0.01 to 100.

[0286] For example, the ratio of the electron mobility of the material of the second light-emitting layer 1311B to the electron mobility of the material of the first light-emitting layer 1311A is 0.01, 0.05, 0.1, 0.5, 1, 6, 10, 20, 50 or 100, etc.

[0287] For example, the ratio between the hole mobility of the material of the second light-emitting layer 1311B and the hole mobility of the material of the first light-emitting layer 1311A is 0.01, 0.05, 0.1, 0.6, 1, 6, 10, 20, 60 or 100, etc.

[0288] Understandably, through the above settings, the electron mobility of the material of the second light-emitting layer 1311B can be made closer to that of the material of the first light-emitting layer 1311A, and the hole mobility of the material of the second light-emitting layer 1311B can be made closer to that of the material of the first light-emitting layer 1311A. In this way, the redshift distance of the spectrum of the light emitted by the first light-emitting layer 1311A and the second light-emitting layer 1311B can be made relatively consistent, thereby improving the color purity of the light emitted by the first light-emitting device 101.

[0289] In some embodiments, as shown in Figures 11 to 14, the ratio between the electron mobility of the material of the fourth light-emitting layer 1312B and the electron mobility of the material of the third light-emitting layer 1312A ranges from 0.01 to 100; the ratio between the hole mobility of the material of the fourth light-emitting layer 1312B and the hole mobility of the material of the third light-emitting layer 1312A ranges from 0.01 to 100.

[0290] For example, the ratio of the electron mobility of the material of the fourth light-emitting layer 1312B to the electron mobility of the material of the third light-emitting layer 1312A is 0.01, 0.03, 0.1, 0.5, 1, 5, 10, 20, 50 or 100, etc.

[0291] For example, the ratio between the hole mobility of the material of the fourth light-emitting layer 1312B and the hole mobility of the material of the third light-emitting layer 1312A is 0.01, 0.05, 0.1, 0.5, 1, 5, 10, 30, 60 or 100, etc.

[0292] Similarly, by setting it up in this way, the electron mobility of the material of the fourth light-emitting layer 1312B can be made closer to that of the material of the third light-emitting layer 1312A, and the hole mobility of the material of the fourth light-emitting layer 1312B can be made closer to that of the material of the third light-emitting layer 1312A. In this way, the redshift distance of the spectrum of the light emitted by the third light-emitting layer 1312A and the fourth light-emitting layer 1312B can be made relatively consistent, thereby improving the color purity of the light emitted by the second light-emitting device 102.

[0293] In some embodiments, as shown in Figures 11 to 14, the ratio between the electron mobility of the material of the sixth light-emitting layer 1313B and the electron mobility of the material of the fifth light-emitting layer 1313A ranges from 0.01 to 100; the ratio between the hole mobility of the material of the sixth light-emitting layer 1313B and the hole mobility of the material of the fifth light-emitting layer 1313A ranges from 0.01 to 100.

[0294] For example, the ratio between the electron mobility of the material of the sixth light-emitting layer 1313B and the electron mobility of the material of the fifth light-emitting layer 1313A is 0.01, 0.06, 0.1, 0.5, 1, 5, 10, 20, 50 or 100, etc.

[0295] For example, the ratio between the hole mobility of the material of the sixth light-emitting layer 1313B and the hole mobility of the material of the fifth light-emitting layer 1313A is 0.01, 0.05, 0.1, 0.5, 1, 5, 10, 20, 40 or 100, etc.

[0296] Similarly, by setting it up in this way, the electron mobility of the material of the sixth light-emitting layer 1313B can be made closer to that of the material of the fifth light-emitting layer 1313A, and the hole mobility of the material of the sixth light-emitting layer 1313B can be made closer to that of the material of the fifth light-emitting layer 1313A. In this way, the redshift distance of the spectrum of the light emitted by the fifth light-emitting layer 1313A and the sixth light-emitting layer 1313B can be made relatively consistent, thereby improving the color purity of the light emitted by the third light-emitting device 103.

[0297] In some embodiments, as shown in Figures 11-14, the second electrode 16 is an anode; the first functional unit 17 and the second functional unit 18 are hole transport units; in the same light-emitting device 100, the absolute value of the difference between the highest occupied molecular orbital energy level of the material of the second functional layer 172 and the highest occupied molecular orbital energy level of the material of the first functional layer 171 is greater than or equal to 0.1 eV and less than or equal to 0.4 eV. The light-emitting device 100 is any one of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103.

[0298] For example, the first functional layer 171 can be the electron blocking layer of the first light-emitting unit 13A; the second functional layer 172 can be the hole transport layer of the first light-emitting unit 13A. In this case, 0.1eV≤|HOMO(HTL1)-HOMO(EBL1)|≤0.4eV.

[0299] For example, the absolute value of the difference between the highest occupied molecular orbital energy level of the material of the second functional layer 172 and the highest occupied molecular orbital energy level of the material of the first functional layer 171 can be 0.1 eV, 0.2 eV, 0.25 eV, 0.3 eV or 0.4 eV, etc.

[0300] Understandably, when the absolute value of the difference between the highest occupied molecular orbital energy level of the material in the second functional layer 172 and the highest occupied molecular orbital energy level of the material in the first functional layer 171 is large, the energy level barrier between the second functional layer 172 and the first functional layer 171 is high, which may lead to a slower hole transport speed. Therefore, by the above setting, the energy level barrier between the second functional layer 172 and the first functional layer 171 can be reduced, the influence of the energy level barrier on the hole transport speed can be reduced, the hole transport speed in the first light-emitting unit 13A can be accelerated, and holes and electrons can recombine and emit light in the first light-emitting layer 1311A, the third light-emitting layer 1312A or the fifth light-emitting layer 1313A. At the same time, it is beneficial to the balance of charge carriers in the recombination region, so that the recombination region can be further away from the electron blocking layer, thereby improving the luminous efficiency and lifetime of the light-emitting device 100.

[0301] In some embodiments, as shown in Figures 11 to 14, the second electrode 16 is an anode; the first functional unit 17 and the second functional unit 18 are hole transport units; in the same light-emitting device 100, the absolute value of the difference between the highest occupied molecular orbital energy level of the material of the fourth functional layer 182 and the highest occupied molecular orbital energy level of the material of the third functional layer 181 is greater than or equal to 0.1 eV and less than or equal to 0.4 eV; wherein, the light-emitting device 100 is any one of the first light-emitting device 101, the second light-emitting device 102 and the third light-emitting device 103.

[0302] For example, the third functional layer 181 can be the electron blocking layer of the second light-emitting unit 13B; the fourth functional layer 182 can be the hole transport layer of the second light-emitting unit 13B. In this case, 0.1eV≤|HOMO(HTL2)-HOMO(EBL2)|≤0.4eV.

[0303] For example, the absolute value of the difference between the highest occupied molecular orbital energy level of the material of the fourth functional layer 182 and the highest occupied molecular orbital energy level of the material of the third functional layer 181 can be 0.1 eV, 0.2 eV, 0.25 eV, 0.3 eV or 0.4 eV, etc.

[0304] Similarly, this configuration can reduce the energy level barrier between the fourth functional layer 182 and the third functional layer 181, accelerate the hole transport speed in the second light-emitting unit 13B, and enable holes and electrons to recombine and emit light in the second light-emitting layer 1311B, the fourth light-emitting layer 1312B, or the sixth light-emitting layer 1313B. It also helps to balance the charge carriers in the recombination region and improves the luminous efficiency and lifetime of the light-emitting device 100.

[0305] In some embodiments, as shown in Figures 11-14, the second electrode 16 is an anode; the first functional unit 17 and the second functional unit 18 are hole transport units. In the same light-emitting device 100, the hole mobility of the third functional layer 181 is greater than or equal to the hole mobility of the first functional layer 171; the light-emitting device 100 is any one of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103.

[0306] For example, the first functional layer 171 can be the electron blocking layer of the first light-emitting unit 13A; the third functional layer 181 can be the electron blocking layer of the second light-emitting unit 13B.

[0307] Understandably, the holes transmitted by the third functional layer 181 come from the second electrode 16, and the holes transmitted by the first functional layer 171 come from the first charge generation layer 143. Moreover, the number of holes generated by the second electrode 16 is greater than the number of holes generated or injected by the first charge generation layer 143. Therefore, by setting the hole mobility of the third functional layer 181 to be greater than or equal to the hole mobility of the first functional layer 171, the hole transmission speed in the second light-emitting unit 13A can be faster, thereby reducing the driving voltage of the light-emitting device 100.

[0308] In some embodiments, the second electrode 16 is an anode; the first functional unit 17 and the second functional unit 18 are hole transport units; in the same light-emitting device 100, the hole mobility of the fourth functional layer 182 is greater than or equal to the hole mobility of the second functional layer 172; the light-emitting device 100 is any one of the first light-emitting device 101, the second light-emitting device 102 and the third light-emitting device 103.

[0309] For example, the second functional layer 172 can be the hole transport layer of the first light-emitting unit 13A; the fourth functional layer 182 can be the hole transport layer of the second light-emitting unit 13B.

[0310] Understandably, the thickness of the fourth functional layer 182 is usually greater than the thickness of the second functional layer 172. When the fourth functional layer 182 and the second functional layer 172 use different materials, by setting the hole mobility of the fourth functional layer 182 to be greater than or equal to the hole mobility of the second functional layer 172, the hole mobility of the material of the fourth functional layer 182 can be faster, which is conducive to the rapid transmission of holes. In this way, the driving voltage of the light-emitting device 100 can be reduced.

[0311] In some embodiments, as shown in Figures 11-14, the second electrode 16 is an anode; the first functional unit 17 and the second functional unit 18 are hole transport units. In the same light-emitting device 100, the absolute value of the difference between the highest occupied molecular orbital energy level of the material of the first charge-generating layer 143 and the highest occupied molecular orbital energy level of the material of the second functional layer 172 is less than or equal to 0.3 eV. The light-emitting device 100 is any one of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103.

[0312] For example, the first charge generation layer 143 can be a hole generation layer; the second functional layer 172 can be a hole transport layer of the first light-emitting unit 13A; in this case, |HOMO(PCGL)-HOMO(HTL1)|≤0.3eV.

[0313] For example, the absolute value of the difference between the highest occupied molecular orbital energy level of the material of the first charge generation layer 143 and the highest occupied molecular orbital energy level of the material of the second functional layer 172 can be 0, 0.1 eV, 0.2 eV, 0.25 eV or 0.3 eV, etc.

[0314] Understandably, the above settings can reduce the energy level barrier between the first charge generation layer 143 and the second functional layer 172, allowing holes to be effectively injected into the first light-emitting unit 13A. This can improve the luminous efficiency of the light-emitting device 100 and reduce the driving voltage of the light-emitting device 100.

[0315] In some embodiments, as shown in Figures 11-14, the first light-emitting unit 13A further includes a third functional unit 19A located between the first type of light-emitting layer and the first electrode 15. The third functional unit 19A includes a sixth functional layer 191, a seventh functional layer 192, and an eighth functional layer 193 arranged sequentially along the direction close to the first electrode 15. The second light-emitting unit 13B further includes a fourth functional unit 19B located between the second type of light-emitting layer and the second charge-generating layer 144; the fourth functional unit 19B includes a ninth functional layer 194. The third functional unit 19A and the fourth functional unit 19B are electron transport units.

[0316] It should be understood that when the third functional unit 19A and the fourth functional unit 19B are electron transport units, the third functional unit 19A can transport electrons generated by the first electrode 15 to the first type of light-emitting layer; when the second functional unit 18 is located between the second type of light-emitting layer and the second electrode 16, the fourth functional unit 19B can transport electrons generated or injected by the second charge generation layer 144 to the second type of light-emitting layer.

[0317] For example, the sixth functional layer 191 can be a hole blocking layer of the first light-emitting unit 13A, the seventh functional layer 192 can be an electron transport layer of the first light-emitting unit 13A, and the eighth functional layer 193 can be an electron injection layer of the first light-emitting unit 13A.

[0318] For example, the ninth functional layer 194 can be a hole blocking layer of the second light-emitting unit 13B.

[0319] In some examples, the size of the sixth functional layer 191 along the first direction X is 5nm to 15nm; for example, 5nm, 7nm, 9nm, 11nm, 13nm or 15nm.

[0320] In some examples, the size of the seventh functional layer 192 along the first direction X is 20nm to 100nm; for example, 20nm, 40nm, 54nm, 60nm, 75nm, 80nm or 100nm, etc.

[0321] In some examples, the size of the eighth functional layer 193 along the first direction X is 1nm to 15nm; for example, 1nm, 2nm, 3nm, 5nm, 7nm, 9nm, 12nm or 15nm, etc.

[0322] In some examples, the ninth functional layer 194 has a size of 5nm to 15nm along the first direction X; for example, 5nm, 7nm, 9nm, 11nm, 12nm, 13nm or 15nm, etc.

[0323] Understandably, through the above configuration, the third functional unit 19A can be used to improve the electron transport performance of the first light-emitting unit 13A, thereby achieving efficient electron generation, effective electron injection, and rapid electron transport in the first light-emitting unit 13A; the fourth functional unit 19B can be used to improve the electron transport performance of the second light-emitting unit 13B, thereby achieving efficient electron generation, effective electron injection, and rapid electron transport in the second light-emitting unit 13B.

[0324] In some embodiments, as shown in Figures 11 to 14, in the same light-emitting device 100, the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the material of the sixth functional layer 191 and the lowest unoccupied molecular orbital energy level of the material of the seventh functional layer 192 is greater than or equal to 0.4 eV and less than or equal to 1.0 eV; wherein, the light-emitting device 100 is any one of the first light-emitting device 101, the second light-emitting device 102 and the third light-emitting device 103.

[0325] For example, when the sixth functional layer 191 can be a hole blocking layer and the seventh functional layer 192 can be an electron transport layer, the materials of the sixth functional layer 191 and the seventh functional layer 192 satisfy the following: 0.4eV≤|LOMO(HBL1)-LOMO(ETL1)|≤1.0eV.

[0326] For example, the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the material of the sixth functional layer 191 and the lowest unoccupied molecular orbital energy level of the material of the seventh functional layer 192 can be 0.4 eV, 0.5 eV, 0.6 eV, 0.7 eV, 0.8 eV or 1.0 eV, etc.

[0327] Understandably, the above configuration can increase the energy level barrier between the sixth functional layer 191 and the seventh functional layer 192, thereby slowing down the electron transport rate in the first light-emitting unit 13A. This allows the electron transport rate to be better matched with the hole transport rate, and the recombination region of electrons and holes to be located in the first light-emitting layer 1311A, the third light-emitting layer 1312A, or the fifth light-emitting layer 1313A. At the same time, it is beneficial to the balance of charge carriers in the recombination region, allowing the recombination region to be further away from the electron blocking layer, which can improve the luminous efficiency and lifetime of the light-emitting device 100.

[0328] In some embodiments, as shown in Figures 11 to 14, the fourth functional unit 19B further includes a tenth functional layer 195 located between the ninth functional layer 194 and the charge generation unit 14. In the same light-emitting device 100, the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the material of the ninth functional layer 194 and the lowest unoccupied molecular orbital energy level of the material of the tenth functional layer 195 is greater than or equal to 0.4 eV and less than or equal to 1.0 eV. The light-emitting device 100 is any one of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103.

[0329] For example, if the ninth functional layer 194 can be a hole blocking layer, the tenth functional layer 195 can be an electron transport layer of the second light-emitting unit 13B. The materials of the ninth functional layer 194 and the tenth functional layer 195 satisfy the following: 0.4eV≤|LOMO(HBL2)-LOMO(ETL2)|≤1.0eV.

[0330] For example, the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the material in the ninth functional layer 194 and the lowest unoccupied molecular orbital energy level of the material in the tenth functional layer 195 can be 0.4 eV, 0.5 eV, 0.6 eV, 0.75 eV, 0.8 eV or 1.0 eV, etc.

[0331] Understandably, the above configuration can increase the energy level barrier between the ninth functional layer 194 and the tenth functional layer 195, thereby slowing down the electron transport rate in the second light-emitting unit 13B. This allows the recombination region of electrons and holes to be located in the second light-emitting layer 1311B, the fourth light-emitting layer 1312B, or the sixth light-emitting layer 1313B. It also helps to balance the carriers in the recombination region, allowing the recombination region to be further away from the electron blocking layer, which can improve the luminous efficiency and lifetime of the light-emitting device 100.

[0332] In some embodiments, as shown in Figures 11-14, in the same light-emitting device 100, the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the material of the second charge-generating layer 144 and the lowest unoccupied molecular orbital energy level of the material of the ninth functional layer 194 is less than or equal to 0.5 eV. The light-emitting device 100 is any one of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103.

[0333] It should be understood that, in the case where the fourth functional unit 19B also includes a ninth functional layer 194, but does not include the aforementioned tenth functional layer 195, the ninth functional layer 194 can be a film layer in contact with the second charge generation layer 144. For example, the ninth functional layer 194 can be a hole-blocking layer of the second light-emitting unit 13B, and the second charge generation layer 144 can be an electron-generating layer; in this case, the materials of the ninth functional layer 194 and the second charge generation layer 144 satisfy the following condition: |LOMO(NCGL)-LOMO(HBL2)|≤0.5eV.

[0334] For example, the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the material of the second charge generation layer 144 and the lowest unoccupied molecular orbital energy level of the material of the ninth functional layer 194 can be 0, 0.1 eV, 0.2 eV, 0.3 eV, 0.4 eV or 0.5 eV, etc.

[0335] Understandably, the above configuration can reduce the energy level barrier between the second charge generation layer 144 and the ninth functional layer 194, allowing electrons to be effectively injected into the second light-emitting unit 13B. This can improve the luminous efficiency of the light-emitting device 100 and reduce the driving voltage of the light-emitting device 100.

[0336] In some embodiments, as shown in Figures 11-14, in the same light-emitting device 100, the fourth functional unit 19B further includes a tenth functional layer 195 located between the ninth functional layer 194 and the charge-generating unit 14. The absolute value of the difference between the lowest unoccupied molecular orbital energy level of the material of the second charge-generating layer 144 and the lowest unoccupied molecular orbital energy level of the material of the tenth functional layer 195 is less than or equal to 0.5 eV. The light-emitting device 100 is any one of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103.

[0337] It should be understood that when the fourth functional unit 19B further includes a ninth functional layer 194 and a tenth functional layer 195, the tenth functional layer 195 can be a film layer in contact with the second charge generation layer 144. For example, the tenth functional layer 195 can be an electron transport layer of the second light-emitting unit 13B, and the second charge generation layer 144 can be an electron generation layer; in this case, the materials of the tenth functional layer 195 and the second charge generation layer 144 satisfy the following condition: |LOMO(NCGL)-LOMO(ETL2)|≤0.5eV.

[0338] For example, the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the material of the second charge generation layer 144 and the lowest unoccupied molecular orbital energy level of the material of the tenth functional layer 195 can be 0, 0.1 eV, 0.25 eV, 0.3 eV, 0.4 eV or 0.5 eV, etc.

[0339] Understandably, the above configuration can reduce the energy level barrier between the second charge generation layer 144 and the tenth functional layer 195, allowing electrons to be effectively injected into the second light-emitting unit 13B. This can improve the luminous efficiency of the light-emitting device 100 and reduce the driving voltage of the light-emitting device 100.

[0340] In some embodiments, as shown in Figures 11-14, the material of the light-emitting layer 131 includes a third host material and a guest material. The mass percentage of the guest material in the material of the light-emitting layer 131 is less than the mass percentage of the third host material in the material of the light-emitting layer. The light-emitting layer 131 is any one of the first light-emitting layer 1311A, the second light-emitting layer 1311B, the third light-emitting layer 1312A, the fourth light-emitting layer 1312B, the fifth light-emitting layer 1313A, and the sixth light-emitting layer 1313B.

[0341] As mentioned above, the third host material can be configured to: transport holes or electrons, and / or, recombine electrons with holes to form excitons, and transfer the exciton energy to the guest material. The guest material can be configured to: emit photons using the exciton energy transferred by the third host material, and / or, recombine electrons with holes to form excitons and emit photons. In this way, the light-emitting layer can achieve its light-emitting function. Moreover, by setting the mass ratio of the guest material in the material of the light-emitting layer 131 to be less than the mass ratio of the third host material in the material of the light-emitting layer 131, the mass ratio of the guest material in the material of the light-emitting layer 131 can be kept within a suitable range, resulting in higher luminous efficiency of the light-emitting device 100.

[0342] In some embodiments, as shown in Figures 11 to 14, in the same first light-emitting unit 13A, the absolute value of the difference between the highest occupied molecular orbital energy level of the third host material Host and the highest occupied molecular orbital energy level of the material of the first functional layer 171 is less than or equal to 0.3 eV.

[0343] For example, when the first functional layer 171 is an electron blocking layer, the material of the first functional layer 171 and the third host material Host satisfy the following condition: |HOMO(Host)-HOMO(EBL1)|≤0.3eV.

[0344] For example, the absolute value of the difference between the highest occupied molecular orbital energy level of the third host material Host and the highest occupied molecular orbital energy level of the first functional layer 171 can be 0, 0.1 eV, 0.15 eV, 0.2 eV, 0.24 eV or 0.3 eV, etc.

[0345] Understandably, the above settings can reduce the energy level barrier between the third host material and the material of the first functional layer 171, increase the hole transport rate in the first light-emitting unit 13A, and enable holes and electrons to recombine and emit light in the first light-emitting layer 1311A, the third light-emitting layer 1312A, or the fifth light-emitting layer 1313A. At the same time, it is beneficial to the balance of charge carriers in the recombination region, so that the recombination region can be further away from the electron blocking layer, thereby improving the luminous efficiency and lifetime of the light-emitting device 100.

[0346] In some embodiments, as shown in Figures 11 to 14, in the same second light-emitting unit 13B, the absolute value of the difference between the highest occupied molecular orbital energy level of the third host material and the highest occupied molecular orbital energy level of the material of the third functional layer 181 is less than or equal to 0.3 eV.

[0347] For example, when the third functional layer 181 is an electron blocking layer, the material of the third functional layer 181 and the third host material Host satisfy the following: |HOMO(Host)-HOMO(EBL2)|≤0.3eV.

[0348] For example, the absolute value of the difference between the highest occupied molecular orbital energy level of the third host material Host and the highest occupied molecular orbital energy level of the material of the third functional layer 181 can be 0, 0.1 eV, 0.13 eV, 0.2 eV, 0.25 eV or 0.3 eV, etc.

[0349] Similarly, the above configuration can reduce the energy level barrier between the third host material and the third functional layer 181, allowing holes and electrons to recombine and emit light in the second light-emitting layer 1311B, the fourth light-emitting layer 1312B, or the sixth light-emitting layer 1313B. This also helps to balance the charge carriers in the recombination region, thereby improving the luminous efficiency and lifetime of the light-emitting device 100.

[0350] In some embodiments, as shown in Figures 11 to 14, in the same first light-emitting unit 13A, the difference between the lowest unoccupied molecular orbital energy level of the material of the first functional layer 171 and the lowest unoccupied molecular orbital energy level of the third host material is greater than or equal to 0.3 eV.

[0351] For example, when the first functional layer 171 is an electron blocking layer, the material of the first functional layer 171 and the third host material Host satisfy the following condition: HOMO(EBL1)-HOMO(Host)≥0.3eV.

[0352] For example, the difference between the lowest unoccupied molecular orbital energy level of the material of the first functional layer 171 and the lowest unoccupied molecular orbital energy level of the third host material can be 0.3, 0.4 eV, 0.5 eV, 0.6 eV, 0.65 eV or 0.7 eV, etc.

[0353] Understandably, the electron blocking performance of the first functional layer 171 can be improved through the above settings, which can enable holes and electrons to recombine and emit light in the first light-emitting layer 1311A, the third light-emitting layer 1312A or the fifth light-emitting layer 1313A. At the same time, it is beneficial to the balance of charge carriers in the recombination region, so that the recombination region can be further away from the electron blocking layer, thereby improving the luminous efficiency and lifetime of the light-emitting device 100.

[0354] In some embodiments, as shown in Figures 11 to 14, in the same second light-emitting unit 13B, the difference between the lowest unoccupied molecular orbital energy level of the material of the third functional layer 181 and the lowest unoccupied molecular orbital energy level of the third host material Host is greater than or equal to 0.3 eV.

[0355] For example, when the third functional layer 181 is an electron blocking layer, the material of the third functional layer 181 and the third host material Host satisfy the following condition: HOMO(EBL2)-HOMO(Host)≥0.3eV.

[0356] For example, the difference between the lowest unoccupied molecular orbital energy level of the material of the third functional layer 181 and the lowest unoccupied molecular orbital energy level of the third host material can be 0.3, 0.4 eV, 0.5 eV, 0.6 eV, 0.7 eV or 0.8 eV, etc.

[0357] Understandably, the electron blocking performance of the third functional layer 181 can be improved through the above settings, which can enable holes and electrons to recombine and emit light in the second light-emitting layer 1311B, the fourth light-emitting layer 1312B or the sixth light-emitting layer 1313B. At the same time, it is beneficial to the balance of charge carriers in the recombination region, so that the recombination region can be further away from the electron blocking layer, thereby improving the luminous efficiency and lifetime of the light-emitting device 100.

[0358] In some embodiments, as shown in Figures 11 to 14, when the first light-emitting unit 13A further includes a sixth functional layer 191, the difference between the highest occupied molecular orbital energy level of the material of the sixth functional layer 191 and the highest occupied molecular orbital energy level of the third host material Host in the same first light-emitting unit 13A is greater than or equal to 0.3 eV.

[0359] For example, when the sixth functional layer 191 is a hole blocking layer, the material of the sixth functional layer 191 and the third host material Host satisfy the following condition: HOMO(HBL1)-HOMO(Host)≥0.3eV.

[0360] For example, the difference between the highest occupied molecular orbital energy level of the material of the sixth functional layer 191 and the highest occupied molecular orbital energy level of the third host material Host can be 0.3 eV, 0.4 eV, 0.5 eV, 0.6 eV or 0.7 eV, etc.

[0361] Understandably, the hole blocking performance of the sixth functional layer 191 can be improved through the above settings, which can enable holes and electrons to recombine and emit light in the first light-emitting layer 1311A, the third light-emitting layer 1312A or the fifth light-emitting layer 1313A. At the same time, it is beneficial to the balance of charge carriers in the recombination region, so that the recombination region can be further away from the electron blocking layer, thereby improving the luminous efficiency and lifetime of the light-emitting device 100.

[0362] In some embodiments, as shown in Figures 11 to 14, when the second light-emitting unit 13B further includes a ninth functional layer 194, the difference between the highest occupied molecular orbital energy level of the material of the ninth functional layer 194 and the highest occupied molecular orbital energy level of the third host material Host in the same second light-emitting unit 13B is greater than or equal to 0.3 eV.

[0363] For example, when the ninth functional layer 194 is a hole blocking layer, the material of the ninth functional layer 194 and the third host material Host satisfy the following condition: HOMO(HBL1)-HOMO(Host)≥0.3eV.

[0364] For example, the difference between the highest occupied molecular orbital energy level of the material in the ninth functional layer 194 and the highest occupied molecular orbital energy level of the third host material Host can be 0.3 eV, 0.4 eV, 0.5 eV, 0.65 eV or 0.8 eV, etc.

[0365] Understandably, the hole blocking performance of the ninth functional layer 194 can be improved through the above settings, which can enable holes and electrons to recombine and emit light in the second light-emitting layer 1311B, the fourth light-emitting layer 1312B or the sixth light-emitting layer 1313B. At the same time, it is beneficial to the balance of charge carriers in the recombination region, so that the recombination region can be further away from the electron blocking layer, thereby improving the luminous efficiency and lifetime of the light-emitting device 100.

[0366] In some embodiments, as shown in Figures 11 to 14, when the first light-emitting unit 13A further includes a sixth functional layer 191, the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the material of the sixth functional layer 191 and the lowest unoccupied molecular orbital energy level of the third host material Host in the same first light-emitting unit 13A is less than or equal to 0.3 eV.

[0367] For example, when the sixth functional layer 191 is a hole blocking layer, the material of the sixth functional layer 191 and the third host material Host satisfy the following: |LOMO(HBL1)-LOMO(Host)|≤0.3eV.

[0368] For example, the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the material of the sixth functional layer 191 and the lowest unoccupied molecular orbital energy level of the third host material can be 0, 0.1 eV, 0.16 eV, 0.2 eV, 0.25 eV or 0.3 eV, etc.

[0369] Understandably, the above configuration can reduce the energy level barrier between the sixth functional layer 191 and the third host material, which is beneficial to the transport of electrons in the first light-emitting unit 13A. Holes and electrons can recombine and emit light in the first light-emitting layer 1311A, the third light-emitting layer 1312A, or the fifth light-emitting layer 1313A. At the same time, it is beneficial to the balance of charge carriers in the recombination region, so that the recombination region can be further away from the electron blocking layer, thereby improving the luminous efficiency and lifetime of the light-emitting device 100.

[0370] In some embodiments, as shown in Figures 11 to 14, when the second light-emitting unit 13B further includes a ninth functional layer 194, the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the material of the ninth functional layer 194 and the lowest unoccupied molecular orbital energy level of the third host material Host in the same second light-emitting unit 13B is less than or equal to 0.3 eV.

[0371] For example, when the ninth functional layer 194 is a hole blocking layer, the material of the ninth functional layer 194 and the third host material Host satisfy the following: |LOMO(HBL2)-LOMO(Host)|≤0.3eV.

[0372] For example, the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the material of the ninth functional layer 194 and the lowest unoccupied molecular orbital energy level of the third host material can be 0, 0.1 eV, 0.15 eV, 0.2 eV, 0.22 eV, 0.25 eV or 0.3 eV, etc.

[0373] Understandably, the above configuration can reduce the energy level barrier between the ninth functional layer 194 and the third host material, which is beneficial for electron transport in the second light-emitting unit 13B. Holes and electrons can recombine and emit light in the second light-emitting layer 1311B, the fourth light-emitting layer 1312B, or the sixth light-emitting layer 1313B. At the same time, it is beneficial for the balance of charge carriers in the recombination region, allowing the recombination region to be further away from the electron blocking layer, thereby improving the luminous efficiency and lifetime of the light-emitting device 100.

[0374] In order to objectively evaluate the technical effects of the embodiments of this disclosure, the technical solutions provided by this disclosure will be described in detail and by way of example through the following experimental examples and comparative examples. According to the evaluation purpose of the embodiments, the following experimental examples and comparative examples are divided into a first group of experimental examples and a second group of experimental examples.

[0375] [First Group of Test Cases]

[0376] The following examples and comparative examples prepared display substrates 200 with different relationships between film thicknesses. The structure of the display substrate 200 is shown in Figure 15, and the structure of the light-emitting device 100 in the display substrate 200 is shown in Figure 16.

[0377] Exemplarily, the method for fabricating a display substrate 200 including a first light-emitting device 101, a second light-emitting device 102, and a third light-emitting device 103 is as follows: a substrate 210 (glass substrate) having a pixel defining layer 221 and a second electrode 15 disposed thereon is used as a back plate, and the back plate is placed in the vacuum chamber of a vacuum evaporation apparatus, and the vacuum is evacuated to 1×10⁻⁶. -5 Pa ~ 1×10 - 6 After Pa, using the materials of the fifth functional layer 183, the fourth functional layer 182, the third functional layer 181, the first type of light-emitting layer, the ninth functional layer 194, the second charge-generating layer 144, the first charge-generating layer 143, the second functional layer 172, the first functional layer 171, the second type of light-emitting layer, the sixth functional layer 191, the seventh functional layer 192, the eighth functional layer 193, and the first electrode 15, the fifth functional layer 183, the fourth functional layer 182, the third functional layer 181, the first type of light-emitting layer, the ninth functional layer 194, the second charge-generating layer 144, the first charge-generating layer 143, the second functional layer 172, the first functional layer 171, the second type of light-emitting layer, the sixth functional layer 191, the seventh functional layer 192, the eighth functional layer 193, and the first electrode 15 are sequentially formed on the back plate. Before use, the back panel is first ultrasonically treated in a cleaning agent, then rinsed with deionized water, then ultrasonically treated in an acetone-ethanol mixed solvent to remove oil, and then dried in a clean environment until moisture and solvent are removed.

[0378] The materials used in Examples 1 to 6 and Comparative Examples 1 to 9 for the fifth functional layer 183, the fourth functional layer 182, the ninth functional layer 194, the second charge generating layer 144, the first charge generating layer 143, the second functional layer 172, the eighth functional layer 193, the seventh functional layer 192, the sixth functional layer 191, and the first electrode 15 are the same. For example, the material of the fifth functional layer 183 in Example 1 is the same as the material of the fifth functional layer 183 in Example X and the same as the material of the fifth functional layer 183 in Comparative Example Y, where X is 2, 3, 4, 5, or 6, Y is any one of 1 to 9, and Y is a positive integer.

[0379] The materials of the fourth functional layer 182 and the second functional layer 172 have the structures shown in formula (HTL). The materials of the ninth functional layer 194 and the sixth functional layer 191 have the structures shown in formula (HBL). The material of the seventh functional layer 192 includes an electron transport material with the structure shown in formula (ETL) and a doped material with the structure shown in formula (LiQ) (the mass ratio of the two materials is 1:1). The material of the eighth functional layer 193 is ytterbium (thickness is 1 nm). The material of the first electrode 15 is a magnesium-silver alloy with a magnesium-silver mass ratio of 1:9. The material of the fifth functional layer 183 includes a hole injection material with the structure shown in formula (HIL) and a hole transport material with the structure shown in formula (HTL), and the mass ratio of the two is 5:95. The material of the first charge generation layer 143 includes a first host material with the structure shown in formula (PCGL-H) and a doped material with the structure shown in formula (D-PCGL-W), and the doping ratio of the doped material is 5%. The material of the second charge generation layer 144 includes a host material with the structure shown in the formula (D-NCGL-H) and a second doped material ytterbium, wherein the doping ratio of the second doped material is 1%.

[0380] In Examples 1-6 and Comparative Examples 1-9, the materials used for the light-emitting layer of the first light-emitting unit 13A, the light-emitting layer of the second light-emitting unit 13B, the third functional layer 181, and the first functional layer 171 in the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 are different. The materials used for the light-emitting layer of the first light-emitting unit 13A, the light-emitting layer of the second light-emitting unit 13B, the third functional layer 181, and the first functional layer 171 in Examples 1-6 and Comparative Examples 1-9 will be described below.

[0381] In the first light-emitting device 101, the materials of the third functional layer 181 and the first functional layer 171 have the following structure (BEBL). The materials of the first light-emitting layer 1311A and the second light-emitting layer 1311B are the same, both including the third host material with the following structure (BH) and the guest material with the following structure (BD).

[0382] In the second light-emitting device 102, the materials of the third functional layer 181 and the first functional layer 171 have the following structure (GEBL). The materials of the third light-emitting layer 1312A and the fourth light-emitting layer 1312B are the same, both including a third host material and a guest material with the following structure (GD). The third host material includes a first material with the following structure (GH-1) and a second material with the following structure (GH-2), and the first material and the second material are premixed before evaporation.

[0383] In the third light-emitting device 103, the materials of the third functional layer 181 and the first functional layer 171 have the following structure (REBL). The materials of the fifth light-emitting layer 1313A and the sixth light-emitting layer 1313B are the same, both including a third host material and a guest material with the following structure (RD); wherein, the third host material includes a third material with the following structure (RH-1) and a fourth material with the following structure (RH-2), and the third material and the fourth material are premixed before evaporation.

[0384] It should be noted that (HIL), (HTL), (EBL), (GH-1), (GH-2), (GD), (HBL), (ETL), (PCGL-H), (D-PCGL-W), (D-NCGL-H), etc. in the above structural formulas are the names of each structural formula, and are not part of the structural formula structure.

[0385] To more clearly illustrate the differences in the relationship between the film thicknesses set in the embodiments and comparative examples, Table 1 below is used to more clearly show the relationship between the film thicknesses set in the embodiments and comparative examples.

[0386] Table 1

[0387] Table 2

[0388] Table 3

[0389] Table 4

[0390] Table 5

[0391] Table 6

[0392] It should be noted that the values ​​in Tables 1 to 6 refer to the values ​​of the corresponding relational expressions, such as those in Example 1. The corresponding subcell content is "2.09", which refers to the first distance L corresponding to the first light-emitting device in Embodiment 1. 11 The first distance L corresponding to the second light-emitting device 12 and the first distance L corresponding to the third light-emitting device 103 13 The calculated first ratio is 2.09. Wherein, the first distance L... 11 L 12 L 13 The second distance L 21 L 22 L 23And the dimension L of the first light-emitting layer 1311A along the first direction X 311 The third light-emitting layer 1312A has a dimension L along the first direction X. 321 The fifth light-emitting layer 1313A along the first direction X has a dimension L. 331 The meanings represented can be found in the aforementioned content, and will not be repeated here.

[0393] Based on the above settings, the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 in the display substrate 200 of Examples 1 to 3 and Comparative Examples 1 to 4 are subjected to a current density of 15 mA / cm². 2 Voltage (V), current efficiency (cd / A), and device lifetime were tested under the specified conditions. The test results are shown in Tables 7 and 8 below. In Table 7, the data for voltage (V), current efficiency (cd / A), and device lifetime are based on Example 1, and in Table 8, the data for voltage (V), current efficiency (cd / A), and device lifetime are based on Example 2. Device lifetime is characterized by the parameter LT95.

[0394] Table 7

[0395] Compared with Comparative Examples 2 and 3, as shown in Table 7, Example 1 exhibits relatively higher current efficiency. This is because in Example 1, the thicknesses of the first light-emitting unit 13A and the first charge-generating layer 143 in the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 are different. This allows the light-emitting region of the first light-emitting unit 13A in the first light-emitting device 101 to be located in the microcavity enhancement region of the first light-emitting device 101, the light-emitting region of the first light-emitting unit 13A in the second light-emitting device 102 to be located in the microcavity enhancement region of the second light-emitting device 102, and the light-emitting region of the first light-emitting unit 13A in the third light-emitting device 103 to be located in the microcavity enhancement region of the third light-emitting device 103. This creates a strong microcavity effect, optimizes the spectrum emitted by the display substrate 200, and improves the current efficiency of the display substrate 200.

[0396] Table 8

[0397] Compared with Comparative Examples 3 and 4 (see Table 8), Examples 2 and 3 exhibit relatively higher current efficiency and longer lifespan. This is because the thicknesses of the first light-emitting layer 1311A, the third light-emitting layer 1312A, and the fifth light-emitting layer 1313A are different. This allows the region of hole-electron recombination in the first light-emitting unit 13A of the first light-emitting device 101 to be located in the first light-emitting layer 1311A, the region of hole-electron recombination in the first light-emitting unit 13A of the second light-emitting device 102 to be located in the third light-emitting layer 1312A, and the region of hole-electron recombination in the first light-emitting unit 13A of the third light-emitting device 103 to be located in the fifth light-emitting layer 1313A. This improves exciton utilization, thus increasing the current efficiency of the display substrate 200, and reduces the impact of exciton energy on other film materials, thereby increasing the lifespan of the display substrate 200. Moreover, compared with Example 2, Example 3 has a relatively lower voltage, a relatively higher current efficiency, and a relatively longer lifespan, indicating that when the third ratio is 1.0, the voltage, efficiency, and lifespan of the light-emitting device 100 and the display substrate 200 can be better optimized.

[0398] [Second Group of Test Examples]

[0399] The following examples and comparative examples used different materials to prepare display substrates 200 with varying film thickness relationships. The structure of the display substrate 200 is shown in Figure 15, and the structure of the light-emitting device 100 within the display substrate 200 is shown in Figure 16. The fabrication method of the display substrate 200 can be referred to the fabrication method of the display substrate 200 in the first set of experimental examples, and will not be repeated here.

[0400] In Examples 7 to 12 and Comparative Example 10, the materials used for the fifth functional layer 183, fourth functional layer 182, third functional layer 181, first type of light-emitting layer, ninth functional layer 194, second functional layer 172, first functional layer 171, second type of light-emitting layer, eighth functional layer 193, seventh functional layer 192, sixth functional layer 191 and first electrode 15 in the first light-emitting device 101, second light-emitting device 102 and third light-emitting device 103 are the same. Furthermore, the materials of the fifth functional layer 183, fourth functional layer 182, third functional layer 181, first type of light-emitting layer, ninth functional layer 194, second functional layer 172, first functional layer 171, second type of light-emitting layer, eighth functional layer 193, seventh functional layer 192, sixth functional layer 191 and first electrode 15 in Examples 7 to 12 and Comparative Example 10 are the same as the materials of the fifth functional layer 183, fourth functional layer 182, third functional layer 181, first type of light-emitting layer, ninth functional layer 194, second functional layer 172, first functional layer 171, second type of light-emitting layer, eighth functional layer 193, seventh functional layer 192, sixth functional layer 191 and first electrode 15 used in the first set of test examples. Therefore, the structure and addition ratio of the above materials can be referred to the materials of the display substrate 200 in the first set of test examples, and will not be repeated here.

[0401] The materials of the first charge generating layer 143 and the second charge generating layer 144 in Examples 7 to 12 and Comparative Example 10 are different, and the relationship between the film thicknesses (the first ratio and the third ratio) is also different. The materials of the second charge generating layer 144 and the first charge generating layer 143 in Examples 7 to 12 and Comparative Example 10, as well as the relationship between the film thicknesses (the first ratio and the third ratio), are described below.

[0402] In Example 7, the material of the first charge generation layer 143 includes a first host material with the structure shown above (PCGL-H) and a doped material with the structure shown above (G1-9), and the doping ratio of the doped material is 5%. The material of the second charge generation layer 144 includes a host material with the structure shown above (D-NCGL-H) and a second doped material ytterbium, and the doping ratio of the second doped material is 1%. The first ratio is 2.09; the third ratio is 1.15.

[0403] In Example 8, the material of the first charge generation layer 143 includes a first host material with the structure shown above (PCGL-H) and a doped material with the structure shown above (G1-2'), and the doping ratio of the doped material is 5%. The material of the second charge generation layer 144 includes a host material with the structure shown above (D-NCGL-H) and a second doped material ytterbium, and the doping ratio of the second doped material is 1%. The first ratio is 2.09; the third ratio is 1.15.

[0404] In Example 9, the material of the first charge generation layer 143 includes a first host material with the structure shown above (PCGL-H) and a doped material with the structure shown above (G1-9), and the doping ratio of the doped material is 5%. The material of the second charge generation layer 144 includes a host material with the structure shown above (H2-1) and a second doped material ytterbium, and the doping ratio of the second doped material is 1%. The first ratio is 2.09; the third ratio is 1.15.

[0405] In Example 10, the material of the first charge generation layer 143 includes a first host material with the structure shown above (PCGL-H) and a doped material with the structure shown above (G1-2'), and the doping ratio of the doped material is 5%. The material of the second charge generation layer 144 includes a host material with the structure shown above (H2-1) and a second doped material ytterbium, and the doping ratio of the second doped material is 1%. The first ratio is 2.09; the third ratio is 1.15.

[0406] In Example 11, the material of the first charge generation layer 143 includes a first host material with the structure shown above (PCGL-H) and a doped material with the structure shown above (G1-9), and the doping ratio of the doped material is 5%. The material of the second charge generation layer 144 includes a host material with the structure shown above (H2-1) and a second doped material ytterbium, and the doping ratio of the second doped material is 1%. The first ratio is 2.09; the third ratio is 1.

[0407] In Example 12, the material of the first charge generation layer 143 includes a first host material with the structure shown above (PCGL-H) and a doped material with the structure shown above (G1-2'), and the doping ratio of the doped material is 5%. The material of the second charge generation layer 144 includes a host material with the structure shown above (H2-1) and a second doped material ytterbium, and the doping ratio of the second doped material is 1%. The first ratio is 2.09; the third ratio is 1.

[0408] In Comparative Example 10, the material of the first charge generation layer 143 includes a first host material with the structure shown above (PCGL-H) and a doped material with the structure shown above (D-PCGL-W), and the doping ratio of the doped material is 5%. The material of the second charge generation layer 144 includes a host material with the structure shown above (D-NCGL-H) and a second doped material ytterbium, and the doping ratio of the second doped material is 1%. The first ratio is 2.09; the third ratio is 1.15.

[0409] To more clearly illustrate the differences in the materials of the first charge generation layer 143 and the second charge generation layer 144 in the embodiments and comparative examples, Table 9 below is used to more clearly show the relationship between the film thicknesses set in the embodiments and comparative examples.

[0410] Table 9

[0411] It should be noted that the values ​​in Table 9 refer to the values ​​of the corresponding relational expressions, such as those in Example 7. The corresponding subcell content is "2.09", which refers to the first distance L corresponding to the first light-emitting device in Embodiment 7. 11 The first distance L corresponding to the second light-emitting device 12 and the first distance L corresponding to the third light-emitting device 103 13 The calculated first ratio is 2.09. Wherein, the first distance L... 11 L 12 L 13 The second distance L 21 L 22 L 23 And the dimension L of the first light-emitting layer 1311A along the first direction X 311 The third light-emitting layer 1312A has a dimension L along the first direction X. 321 The fifth light-emitting layer 1313A along the first direction X has a dimension L. 331 The meanings represented can be found in the aforementioned content, and will not be repeated here.

[0412] In Table 9, "Ax" refers to the corresponding structural formula Ax. For example, the sublattice content corresponding to the doped material of the first charge generation layer in Example 7 is "G1-9", which means that the structural formula of the doped material in the first charge generation layer of Example 7 is as shown in (G1-9). Among them, the structural formulas represented by G1-x, G1-x' (x takes a positive integer), H2-x, D-NCGL-H, and D-PCGL-W are as described above and will not be repeated here.

[0413] Based on the above settings, the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 in the display substrate 200 of Examples 7 to 12 and Comparative Example 10 are subjected to a current density of 15 mA / cm². 2 Voltage (V), current efficiency (cd / A), and device lifetime were tested under the specified conditions. The test results are shown in Table 10 below. The data for voltage (V), current efficiency (cd / A), and device lifetime are compared with Comparative Example 10. Device lifetime is characterized by the parameter LT95.

[0414] Table 10

[0415] Compared with Comparative Example 10, Examples 7 to 12 (see Table 10) show relatively lower voltage, higher current efficiency, and higher lifetime. This is because the material of the first charge generation layer 143 in Examples 7 to 12 includes a first doped material with a structure shown in general formula (I) or general formula (II), and / or the material of the second charge generation layer 144 includes a second host material with a structure shown in general formula (III). The structure shown in general formula (I) or general formula (II) has a strong electron-withdrawing ability, which can enhance the conductivity of the first doped material G1 and improve the hole injection performance of the first charge generation layer 143, thus facilitating the effective generation, injection, and transport of charges and improving the luminous efficiency of the display substrate 200. When the second charge generation layer 144 includes the structure shown in general formula (III), firstly, it can reduce the energy level barrier at the interface (i.e., the first interface) between the first charge generation layer 143 and the second charge generation layer 144, thereby reducing the accumulation of charge carriers caused by the energy level barrier at the first interface, preventing material degradation at the first interface, and improving the lifetime of the display substrate 200; secondly, it can enable electrons to be quickly transported to the second light-emitting unit 13B to achieve radiative emission, thereby reducing the driving voltage of the display substrate; thirdly, it can form a complex with the second doped material ytterbium, thereby suppressing the crystallization of the second host material H2; at the same time, it can increase the electron injection capability of the second charge generation layer 144, improve the charge flow in the light-emitting device 100, and reduce the driving voltage of the display substrate 200. Furthermore, compared with Examples 7 to 10, as shown in Table 10, Examples 11 and 12 have relatively low voltage, relatively high current efficiency, and relatively high lifespan. This indicates that when the third ratio is 1.0, the voltage, efficiency, and lifespan of the light-emitting device 100 and the display substrate 200 can be better optimized.

[0416] As can be seen from the above embodiments and comparative examples, by setting the first ratio in the range of 1.8 to 2.5, the light-emitting area of ​​the first light-emitting unit 13A in the first light-emitting device 101 can be located in the microcavity enhancement region of the first light-emitting device 101, the light-emitting area of ​​the first light-emitting unit 13A in the second light-emitting device 102 can be located in the microcavity enhancement region of the second light-emitting device 102, and the light-emitting area of ​​the first light-emitting unit 13A in the third light-emitting device 103 can be located in the microcavity enhancement region of the third light-emitting device 103. This can form a strong microcavity effect, optimize the spectrum emitted by the display substrate 200, and improve the light extraction efficiency of the display substrate 200. Furthermore, by setting the third ratio in the range of 0.8 to 3.0, the exciton utilization rate can be improved, thereby increasing the luminous efficiency of the display substrate 200. By setting the material of the first charge generation layer 143 to include a first doped material with the structure shown in general formula (I) or general formula (II), and / or setting the material of the second charge generation layer 144 to include a second host material with the structure shown in general formula (III), the efficiency and lifespan of the display substrate 200 can be improved, and the driving voltage of the display substrate 200 can be reduced.

[0417] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A display substrate, comprising: Substrate; and, A first light-emitting device, a second light-emitting device, and a third light-emitting device are disposed on the substrate; the first light-emitting device is used to emit light of a first color; the second light-emitting device is used to emit light of a second color; the wavelength of the second color light is greater than the wavelength of the first color light; the third light-emitting device is used to emit light of a third color; the wavelength of the third color light is greater than the wavelength of the second color light. Each of the first light-emitting device, the second light-emitting device, and the third light-emitting device includes: A first electrode and a second electrode are disposed opposite to each other along a first direction; the second electrode is closer to the substrate than the first electrode. A first light-emitting unit and a second light-emitting unit are located between the first electrode and the second electrode, and are stacked along the first direction; the second light-emitting unit is further away from the first electrode relative to the first light-emitting unit; and, A charge generation unit is located between the first light-emitting unit and the second light-emitting unit; the charge generation unit includes a first charge generation layer and a second charge generation layer stacked along the first direction, wherein the second charge generation layer is further away from the first electrode relative to the first charge generation layer. Wherein, there is a first distance between the surface of the first electrode near the first light-emitting unit and the surface of the first charge-generating layer away from the first light-emitting unit; there is a first difference between the first distance corresponding to the third light-emitting device and the first distance corresponding to the first light-emitting device; there is a second difference between the first distance corresponding to the second light-emitting device and the first distance corresponding to the first light-emitting device; the ratio between the first difference and the second difference is in the range of 1.8 to 2.

5.

2. The display substrate according to claim 1, wherein, There is a second distance between the surface of the second electrode near the second light-emitting unit and the surface of the second charge-generating layer away from the second light-emitting unit; Wherein, the second distance corresponding to the third light-emitting device has a third difference with the second distance corresponding to the second light-emitting device; the second distance corresponding to the second light-emitting device has a fourth difference with the second distance corresponding to the first light-emitting device; the ratio between the third difference and the fourth difference is in the range of 1.0 to 1.

5.

3. The display substrate according to claim 2, wherein, In the first light-emitting device, the ratio between the first distance and the second distance ranges from 0.65 to 0.90; and / or, In the second light-emitting device, the ratio between the first distance and the second distance ranges from 0.60 to 0.85; and / or, In the third light-emitting device, the ratio between the first distance and the second distance ranges from 0.50 to 0.

80.

4. The display substrate according to claim 2 or 3, wherein, In the first light-emitting device, the range of the second distance is within And / or, In the second light-emitting device, the range of the second distance is within And / or, In the third light-emitting device, the range of the second distance is within 5. The display substrate according to any one of claims 1 to 4, wherein, In the first light-emitting device, the first light-emitting unit includes a first light-emitting layer; the second light-emitting unit includes a second light-emitting layer. In the second light-emitting device, the first light-emitting unit includes a third light-emitting layer; the second light-emitting unit includes a fourth light-emitting layer. In the third light-emitting device, the first light-emitting unit includes a fifth light-emitting layer; the second light-emitting unit includes a sixth light-emitting layer. Wherein, the dimension of the fifth light-emitting layer along the first direction has a fifth difference with the dimension of the first light-emitting layer along the first direction, and the dimension of the third light-emitting layer along the first direction has a sixth difference with the dimension of the first light-emitting layer along the first direction; the ratio between the fifth difference and the sixth difference ranges from 0.8 to 3.0; and / or, The dimension of the sixth light-emitting layer along the first direction has a seventh difference with the dimension of the second light-emitting layer along the first direction, and the dimension of the fourth light-emitting layer along the first direction has an eighth difference with the dimension of the second light-emitting layer along the first direction; the ratio between the seventh difference and the eighth difference is in the range of 0.8 to 3.

0.

6. The display substrate according to any one of claims 1 to 5, wherein, The first light-emitting unit further includes a first functional unit located between the first type of light-emitting layer and the charge-generating unit; the first type of light-emitting layer is the first light-emitting layer, the third light-emitting layer, or the fifth light-emitting layer; the first functional unit includes the first functional layer; The second light-emitting unit further includes a second functional unit located between the second type of light-emitting layer and the second electrode; the second type of light-emitting layer is the second light-emitting layer, the fourth light-emitting layer, or the sixth light-emitting layer; the second functional unit includes a third functional layer, a fourth functional layer, and a fifth functional layer arranged sequentially along the direction close to the second electrode.

7. The display substrate according to claim 6, wherein, The first functional unit further includes a second functional layer, which is located between the first functional layer and the charge generating unit.

8. The display substrate according to claim 6 or 7, wherein, In the same light-emitting device, the dimension of the third functional layer along the first direction is greater than or equal to the dimension of the first functional layer along the first direction; the light-emitting device is any one of the first light-emitting device, the second light-emitting device, and the third light-emitting device.

9. The display substrate according to claim 7 or 8, wherein, In the same light-emitting device, the ratio between the dimension of the fourth functional layer along the first direction and the dimension of the second functional layer along the first direction is in the range of 1.5 to 2.5; the light-emitting device is any one of the first light-emitting device, the second light-emitting device and the third light-emitting device.

10. The display substrate according to any one of claims 6 to 9, wherein, The material of the first charge generation layer, and / or the material of the fifth functional layer, includes a first host material and a first doped material; the first host material is a hole-type material; the first doped material is configured to: p-type dope the first host material; When the material of the first charge generation layer includes the first host material and the first doped material, the mass percentage of the first doped material in the material of the first charge generation layer is less than the mass percentage of the first host material in the material of the first charge generation layer. When the material of the fifth functional layer includes the first host material and the first doped material, the mass percentage of the first doped material in the material of the fifth functional layer is less than the mass percentage of the first host material in the material of the fifth functional layer.

11. The display substrate according to claim 10, wherein, The first doped material is selected from any one of the structures shown in the following general formula (I); Where A is any one of the three-membered ring, four-membered ring, five-membered ring and six-membered ring; R1, R2, R3, R4, R5, and R6 may be the same or different, and are independently selected from any one of halogen, cyano, substituted aryl, and substituted or unsubstituted heteroaryl; and, in the case where R1, R2, R3, R4, R5, or R6 is a substituted aryl, the substituent of the aryl includes at least one electron-withdrawing group.

12. The display substrate according to claim 11, wherein, Of R1, R2, R3, R4, R5, and R6, at least one is a cyano group.

13. The display substrate according to claim 10, wherein, The first doped material is selected from any one of the structures shown in general formula (II); Where X1 and X2 are the same or different, and are independently selected from C(R) a ), N and Si(R) b Any one of the following; Y1 and Y2 may be the same or different, and are independently selected from N(R). c Any one of O and S; Ar1, Ar2, Ar3, and Ar4 may be the same or different, and are independently selected from any one of halogen, cyano, substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted fluorenyl, substituted or unsubstituted adamantyl, and substituted or unsubstituted heteroaryl; or may be connected to adjacent groups to form substituted or unsubstituted rings. R7, R8, R a R b and R c Whether the groups are the same or different, they are independently selected from hydrogen, deuterium, halogen, cyano, substituted or unsubstituted C3-C20 heteroaryl, substituted or unsubstituted C6-C20 aryl, substituted or unsubstituted C1-C5 alkyl, substituted or unsubstituted C1-C10 haloalkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C2-C10 heterocycloalkyl, substituted or unsubstituted C1-C10 alkoxy, substituted or unsubstituted C1-C10 alkathio, substituted or unsubstituted C6-C18 aryloxy, substituted or unsubstituted C6-C18 arylthio, substituted or unsubstituted C6-C24 phosphoroxy, and substituted or unsubstituted C6-C18 alkylsulfonyl. m and n may be the same or different, and are independently selected from 1, 2, 3, 4 and 5 respectively.

14. The display substrate according to any one of claims 10 to 13, wherein, The mass percentage of the first doped material in the material of the first charge generation layer is greater than or equal to 0.5% and less than or equal to 10%. And / or, The mass percentage of the first doped material in the material of the fifth functional layer is greater than or equal to 0.5% and less than or equal to 10%.

15. The display substrate according to any one of claims 1 to 14, wherein, The material of the second charge generation layer includes a second host material and a second doped material; in the second charge generation layer, the mass percentage of the second doped material is less than the mass percentage of the second host material. Wherein, the second main material is selected from any one of the structures shown in the following general formula (III); Among them, X3, X4, X5, and X6 may be the same or different, and are independently selected from C(R). d Any one of X3, X4, X5, and X6; and at least two of them are N; Ar5, Ar6, Ar7, and Ar8 may be the same or different, and are independently selected from hydrogen, deuterium, tritium, halogen, cyano, nitro, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C3-C60 alicyclic, substituted or unsubstituted C6-C60 aromatic fused ring, substituted or unsubstituted C1-C50 alkyl, substituted or unsubstituted C2-C20 alkenyl, substituted or unsubstituted C2-C20 alkynyl, etc. The heterocyclic group comprises any one of the following: substituted or unsubstituted C1-C30 alkoxy group, substituted or unsubstituted C6-C30 aryloxy group, substituted or unsubstituted C3-C60 alkylsilyl group, substituted or unsubstituted C18-C60 arylsilyl group, substituted or unsubstituted C8-C60 alkylarylsilyl group, and substituted or unsubstituted C2-C60 heterocyclic group; and the heterocyclic group comprises at least one of O, N, S, Si, and P. R d It is selected from hydrogen, deuterium, substituted or unsubstituted C1-C60 alkyl, substituted or unsubstituted C2-C60 alkenyl, substituted or unsubstituted C2-C60 alkynyl, substituted or unsubstituted C1-C60 alkoxy, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C1-C10 heterocyclic alkyl, substituted or unsubstituted C3-C10 cycloalkenyl, substituted or unsubstituted C1-C10 heterocyclic alkenyl, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C6-C60 aryloxy, substituted or unsubstituted C6-C60 arylthio, substituted or unsubstituted C1-C60 heteroaryl, substituted or unsubstituted monovalent nonaromatic condensed polycyclic group and substituted or unsubstituted monovalent nonaromatic condensed heterocyclic group.

16. The display substrate according to claim 15, wherein, The second doped material includes one or any combination of alkali metals, alkaline earth metals, transition metals, alkali metal compounds, alkaline earth metal compounds, and transition metal compounds.

17. The display substrate according to claim 15 or 16, wherein, The mass percentage of the second doped material in the material of the second charge generation layer is greater than or equal to 0.5% and less than or equal to 3%.

18. The display substrate according to any one of claims 2 to 17, wherein, The wavelength range of the light emitted by the first light-emitting layer and the second light-emitting layer is 440nm to 490nm; and / or, The wavelength range of the light emitted by the third light-emitting layer and the fourth light-emitting layer is 500nm to 540nm; and / or, The wavelength range of the light emitted by the fifth and sixth light-emitting layers is 600nm to 650nm.

19. The display substrate according to any one of claims 2 to 18, wherein, The ratio of the electron mobility of the material of the second light-emitting layer to that of the material of the first light-emitting layer ranges from 0.01 to 100; the ratio of the hole mobility of the material of the second light-emitting layer to that of the material of the first light-emitting layer ranges from 0.01 to 100; and / or, The ratio of the electron mobility of the material in the fourth light-emitting layer to that in the third light-emitting layer ranges from 0.01 to 100; the ratio of the hole mobility of the material in the fourth light-emitting layer to that in the third light-emitting layer ranges from 0.01 to 100; and / or, The ratio of the electron mobility of the material of the sixth light-emitting layer to that of the material of the fifth light-emitting layer is in the range of 0.01 to 100; the ratio of the hole mobility of the material of the sixth light-emitting layer to that of the material of the fifth light-emitting layer is in the range of 0.01 to 100.

20. The display substrate according to any one of claims 7 to 19, wherein, The second electrode is the anode; the first functional unit and the second functional unit are hole transport units; In the same light-emitting device, the absolute value of the difference between the highest occupied molecular orbital energy level of the material in the second functional layer and the highest occupied molecular orbital energy level of the material in the first functional layer is greater than or equal to 0.1 eV and less than or equal to 0.4 eV; and / or, The absolute value of the difference between the highest occupied molecular orbital energy level of the material in the fourth functional layer and the highest occupied molecular orbital energy level of the material in the third functional layer is greater than or equal to 0.1 eV and less than or equal to 0.4 eV. The light-emitting device is any one of the first light-emitting device, the second light-emitting device, and the third light-emitting device.

21. The display substrate according to any one of claims 6 to 20, wherein, The second electrode is an anode; the first functional unit and the second functional unit are hole transport units; in the same light-emitting device, the hole mobility of the third functional layer is greater than or equal to the hole mobility of the first functional layer; the light-emitting device is any one of the first light-emitting device, the second light-emitting device and the third light-emitting device.

22. The display substrate according to any one of claims 7 to 21, wherein, The second electrode is an anode; the first functional unit and the second functional unit are hole transport units; in the same light-emitting device, the hole mobility of the fourth functional layer is greater than or equal to the hole mobility of the second functional layer; the light-emitting device is any one of the first light-emitting device, the second light-emitting device and the third light-emitting device.

23. The display substrate according to any one of claims 7 to 22, wherein, The second electrode is an anode; the first functional unit and the second functional unit are hole transport units; in the same light-emitting device, the absolute value of the difference between the highest occupied molecular orbital energy level of the material of the first charge generation layer and the highest occupied molecular orbital energy level of the material of the second functional layer is less than or equal to 0.3 eV; the light-emitting device is any one of the first light-emitting device, the second light-emitting device and the third light-emitting device.

24. The display substrate according to any one of claims 6 to 23, wherein, The first light-emitting unit further includes a third functional unit located between the first type of light-emitting layer and the first electrode; the third functional unit includes a sixth functional layer, a seventh functional layer and an eighth functional layer arranged sequentially along the direction close to the first electrode; The second light-emitting unit further includes a fourth functional unit located between the second type of light-emitting layer and the second charge-generating layer; the fourth functional unit includes a ninth functional layer; The third functional unit and the fourth functional unit are electronic transmission units.

25. The display substrate according to claim 24, wherein, In the same light-emitting device, the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the material in the sixth functional layer and the lowest unoccupied molecular orbital energy level of the material in the seventh functional layer is greater than or equal to 0.4 eV and less than or equal to 1.0 eV; and / or, The fourth functional unit further includes a tenth functional layer located between the ninth functional layer and the charge generation unit. The absolute value of the difference between the lowest unoccupied molecular orbital energy level of the material in the ninth functional layer and the lowest unoccupied molecular orbital energy level of the material in the tenth functional layer is greater than or equal to 0.4 eV and less than or equal to 1.0 eV. The light-emitting device is any one of the first light-emitting device, the second light-emitting device, and the third light-emitting device.

26. The display substrate according to claim 24 or 25, wherein, In the same light-emitting device, the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the material of the second charge-generating layer and the lowest unoccupied molecular orbital energy level of the material of the ninth functional layer is less than or equal to 0.5 eV; or, The fourth functional unit further includes a tenth functional layer located between the ninth functional layer and the charge generation unit, wherein the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the material of the second charge generation layer and the lowest unoccupied molecular orbital energy level of the material of the tenth functional layer is less than or equal to 0.5 eV. The light-emitting device is any one of the first light-emitting device, the second light-emitting device, and the third light-emitting device.

27. The display substrate according to any one of claims 6 to 26, wherein, The material of the light-emitting layer includes a third host material and a guest material; the mass percentage of the guest material in the material of the light-emitting layer is less than the mass percentage of the third host material in the material of the light-emitting layer; wherein, the light-emitting layer is any one of the first light-emitting layer, the second light-emitting layer, the third light-emitting layer, the fourth light-emitting layer, the fifth light-emitting layer, and the sixth light-emitting layer.

28. The display substrate according to claim 27, wherein, In the same first light-emitting unit, the absolute value of the difference between the highest occupied molecular orbital energy level of the third host material and the highest occupied molecular orbital energy level of the material of the first functional layer is less than or equal to 0.3 eV; and / or, In the same second light-emitting unit, the absolute value of the difference between the highest occupied molecular orbital energy level of the third host material and the highest occupied molecular orbital energy level of the material of the third functional layer is less than or equal to 0.3 eV.

29. The display substrate according to claim 27 or 28, wherein, In the same first light-emitting unit, the difference between the lowest unoccupied molecular orbital energy level of the material of the first functional layer and the lowest unoccupied molecular orbital energy level of the third host material is greater than or equal to 0.3 eV; and / or, In the same second light-emitting unit, the difference between the lowest unoccupied molecular orbital energy level of the material of the third functional layer and the lowest unoccupied molecular orbital energy level of the third host material is greater than or equal to 0.3 eV.

30. The display substrate according to any one of claims 27 to 29, wherein, In the case where the first light-emitting unit further includes the sixth functional layer, and the second light-emitting unit further includes the ninth functional layer; In the same first luminescent unit, the difference between the highest occupied molecular orbital energy level of the material in the sixth functional layer and the highest occupied molecular orbital energy level of the third host material is greater than or equal to 0.3 eV; and / or, In the same second light-emitting unit, the difference between the highest occupied molecular orbital energy level of the material of the ninth functional layer and the highest occupied molecular orbital energy level of the third host material is greater than or equal to 0.3 eV.

31. The display substrate according to any one of claims 17 to 30, wherein, In the case where the first light-emitting unit further includes the sixth functional layer, and the second light-emitting unit further includes the ninth functional layer; In the same first light-emitting unit, the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the material of the sixth functional layer and the lowest unoccupied molecular orbital energy level of the third host material is less than or equal to 0.3 eV; and / or, In the same second light-emitting unit, the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the material of the ninth functional layer and the lowest unoccupied molecular orbital energy level of the third host material is less than or equal to 0.3 eV.

32. A display device comprising a display substrate as described in any one of claims 1 to 31; Also includes: A driver chip, which is used to drive the display substrate to perform display.

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