Light-emitting substrate, display panel and display apparatus

Abstract

Embodiments of the present disclosure relate to the field of display technology, and provide a light-emitting substrate, a display panel and a display apparatus, which can be used to improve the luminous efficacy, service life and color purity of a light-emitting device. The light-emitting substrate comprises a base substrate and multiple light-emitting devices. The plurality of light-emitting devices are disposed on the base substrate and arranged along a first direction, the first direction being parallel to a plane in which the base substrate is located. Each of the multiple light-emitting devices comprises a light-emitting layer, and the material of the light-emitting layer of each of the multiple light-emitting devices comprises a guest material, the guest material being configured to emit light having a set wavelength. The guest material of the light-emitting layer of at least one light-emitting device among the multiple light-emitting devices is a tetradentate ligand material. The light-emitting substrate is used to display an image.

Description

Light-emitting substrate, display panel, and display device

[0001] This application claims priority to Chinese patent application No. 202310919569.7, filed on July 25, 2023, the entire contents of which are incorporated by reference into this application. Technical Field

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

[0003] Organic Light Emitting Diode (OLED) display panels have the advantages of self-luminescence, high color gamut, high saturation, and high response speed. They are widely used in display screens such as mobile phones, tablets, and car displays.

[0004] Summary of the Invention

[0005] In one aspect, a light-emitting substrate is provided. The light-emitting substrate includes a substrate and a plurality of light-emitting devices. The plurality of light-emitting devices are disposed on the substrate and arranged along a first direction parallel to a plane of the substrate. Each of the plurality of light-emitting devices includes a light-emitting layer, and the material of the light-emitting layer of each of the plurality of light-emitting devices includes a guest material, and the guest material is configured to emit light of a set wavelength. The guest material of the light-emitting layer of at least one of the plurality of light-emitting devices is a tetradentate ligand material.

[0006] In some embodiments, the material of the light-emitting layer of each light-emitting device in the multiple light-emitting devices also includes a host material, and the host material includes a first host material and a second host material; in at least one light-emitting device in the multiple light-emitting devices, the difference between the triplet energy level of the first host material and the triplet energy level of the guest material is greater than or equal to 0.2 eV and less than or equal to 0.5 eV; the difference between the triplet energy level of the second host material and the triplet energy level of the guest material is greater than or equal to 0.2 eV and less than or equal to 0.5 eV.

[0007] In some embodiments, the hole mobility of the first host material is greater than the hole mobility of the second host material; the electron mobility of the second host material is greater than the electron mobility of the second host material; in at least one light-emitting device among the multiple light-emitting devices, the absolute value of the difference between the highest occupied molecular orbital energy level of the first host material and the highest occupied molecular orbital energy level of the guest material is greater than or equal to 0.4 eV; the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the second host material and the lowest unoccupied molecular orbital energy level of the guest material is greater than or equal to 0.1 eV.

[0008] In some embodiments, in at least one light-emitting device among the plurality of light-emitting devices, an orientation parameter of the guest material in the host material is greater than or equal to -0.40 and less than or equal to -0.10.

[0009] In some embodiments, a light-emitting layer of at least one of the plurality of light-emitting devices emits light with a half-maximum width of a spectrum greater than or equal to 20 nm and less than or equal to 30 nm.

[0010] In some embodiments, each of the multiple light-emitting devices further includes an anode, a cathode, a hole transport functional layer and an electron transport functional layer; the anode is located on one side of the light-emitting layer; the cathode is located on the other side of the light-emitting layer; the hole transport functional layer is located between the anode and the light-emitting layer, and is configured to transport holes, and / or, block electrons or excitons; the electron transport functional layer is located between the cathode and the light-emitting layer, and is configured to transport electrons, and / or, block holes or excitons; wherein, in the light-emitting layer of at least one light-emitting device among the multiple light-emitting devices, the region where holes and electrons recombine to form excitons is located on the side close to the hole transport functional layer.

[0011] In some embodiments, the plurality of light-emitting devices include a first light-emitting device, a second light-emitting device, and a third light-emitting device arranged along a first direction; wherein the first light-emitting device is configured to emit light of a first wavelength, which is green light; the second light-emitting device is configured to emit light of a second wavelength, which is red light; and the third light-emitting device is configured to emit light of a third wavelength, which is blue light.

[0012] In some embodiments, the guest material of the light-emitting layer of the first light-emitting device is selected from any one of the structures represented by the following general formula (I).

[0013] wherein X1 is selected from oxygen and sulfur. R1, R2, R3, R4, and R5 are the same or different and are independently selected from hydrogen, deuterium, substituted or unsubstituted methyl, substituted or unsubstituted ethyl, substituted or unsubstituted propyl, substituted or unsubstituted isopropyl, substituted or unsubstituted n-butyl, substituted or unsubstituted isobutyl, substituted or unsubstituted sec-butyl, substituted or unsubstituted tert-butyl, substituted or unsubstituted cyclopropyl, substituted or unsubstituted cyclobutyl, substituted or unsubstituted cyclopentyl, substituted or unsubstituted cyclohexyl, and substituted or unsubstituted phenyl. n1 and n5 are the same or different and are independently selected from 0, 1, 2, 3, and 4. n2 is selected from 0, 1, 2, 3, 4, and 5. n3 and n4 are the same or different and are independently selected from 0, 1, 2, and 3.

[0014] In some embodiments, in the first light-emitting device, a mass ratio of the guest material to the host material is greater than or equal to 5% and less than or equal to 14%.

[0015] In some embodiments, the first host material of the light-emitting layer of the first light-emitting device is selected from any one of the structures represented by the following general formula (III).

[0016] Wherein, L1 and L2 are the same or different and are independently selected from any one of substituted or unsubstituted phenylene, substituted or unsubstituted biphenylene and substituted or unsubstituted naphthylene. 11 、R 12 、R 13 、R 14 、R 15 and R 16 are the same or different and are independently selected from any one of hydrogen, deuterium, substituted or unsubstituted methyl, substituted or unsubstituted ethyl, substituted or unsubstituted propyl, substituted or unsubstituted isopropyl, substituted or unsubstituted n-butyl, substituted or unsubstituted isobutyl, substituted or unsubstituted sec-butyl, substituted or unsubstituted tert-butyl, substituted or unsubstituted cyclopropyl, substituted or unsubstituted cyclobutyl, substituted or unsubstituted cyclopentyl, substituted or unsubstituted cyclohexyl and substituted or unsubstituted phenyl. 11 and n 12 The same or different, each independently selected from any one of 0 and 1. 13 and n 16 The same or different, each independently selected from any one of 0, 1, 2, 3 and 4. 14 and n 15 are the same or different and are independently selected from any one of 0, 1 and 2.

[0017] In some embodiments, the second host material of the light-emitting layer of the first light-emitting device is selected from any one of the structures represented by the following general formula (IV).

[0018] Wherein, L3 and L4 are the same or different and are independently selected from any one of substituted or unsubstituted phenylene, substituted or unsubstituted biphenylene and substituted or unsubstituted naphthylene. 17 、R 18 、R 19 、R 20 、R 21 and R 22are the same or different and are independently selected from any one of substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted dimethylfluorenyl, substituted or unsubstituted diphenylfluorenyl, substituted or unsubstituted benzothiophenyl, substituted or unsubstituted benzoxazolyl and substituted or unsubstituted benzimidazolyl. 17 and n 18 The same or different, each independently selected from any one of 0 and 1. 20 and n 22 The same or different, each independently selected from any one of 0, 1, 2, 3 and 4. 21 Select any one from 0, 1 and 2.

[0019] In some embodiments, in the first light-emitting device, a mass ratio between the first host material and the second host material is greater than or equal to 1:1 and less than or equal to 7:3.

[0020] In some embodiments, the guest material of the light-emitting layer of the second light-emitting device is selected from any one of the structures represented by the following general formula (II).

[0021] wherein X2 is selected from any one of oxygen and sulfur. Ar1 is selected from any one of a benzene ring and a naphthalene ring. R6, R7, R8, R9 and R 10 are the same or different and are independently selected from any one of hydrogen, deuterium, substituted or unsubstituted methyl, substituted or unsubstituted ethyl, substituted or unsubstituted propyl, substituted or unsubstituted isopropyl, substituted or unsubstituted n-butyl, substituted or unsubstituted isobutyl, substituted or unsubstituted sec-butyl, substituted or unsubstituted tert-butyl, substituted or unsubstituted cyclopropyl, substituted or unsubstituted cyclobutyl, substituted or unsubstituted cyclopentyl, substituted or unsubstituted cyclohexyl, and substituted or unsubstituted phenyl. n6 is selected from any one of 0, 1, 2, 3, and 4. n7 is selected from any one of 0, 1, 2, 3, 4, and 5. n8 and n9 are the same or different and are independently selected from any one of 0, 1, 2, and 3. 10 Select any one from 0, 1 and 2.

[0022] In some embodiments, the guest material of the light-emitting layer of the second light-emitting device is selected from any one of the structures represented by the following general formula (II-A).

[0023] Wherein, X3 is selected from any one of oxygen and sulfur.

[0024] In some embodiments, in the second light-emitting device, a mass ratio of the guest material to the host material is greater than or equal to 1% and less than or equal to 5%.

[0025] In some embodiments, the first host material of the light-emitting layer of the second light-emitting device is selected from any one of the structures represented by the following general formula (V).

[0026] Among them, R 23 、R 24 、R 25 、R 26 、R 27 and R 28 are the same or different and are independently selected from any one of hydrogen, deuterium, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C1-C6 cycloalkyl, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophenyl and substituted or unsubstituted carbazolyl. 23 and n 24 The same or different, each independently selected from any one of 0, 1, 2, 3, 4 and 5. 25 and n 28 The same or different, each independently selected from any one of 0, 1, 2, 3 and 4. 26 and n 27 are the same or different and are independently selected from any one of 0, 1 and 2.

[0027] In some embodiments, the second host material of the light-emitting layer of the second light-emitting device is selected from any one of the structures represented by the following general formula (VI).

[0028] wherein L5, L6, and L7 are the same or different and are independently selected from any one of substituted or unsubstituted phenylene, substituted or unsubstituted biphenylene, substituted or unsubstituted naphthylene, substituted or unsubstituted dibenzofuranylene, substituted or unsubstituted benzodibenzofuranylene, substituted or unsubstituted dibenzothiophenylene, substituted or unsubstituted benzodibenzothiophenylene, substituted or unsubstituted carbazolylene, substituted or unsubstituted benzocarbazolylene, and substituted or unsubstituted phenanthroxazolylene. 29 、R 30 and R 31 are the same or different and are independently selected from any one of substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted benzodibenzofuranyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted benzodibenzothiophenyl, substituted or unsubstituted carbazolyl, substituted or unsubstituted benzocarbazolyl and substituted or unsubstituted phenanthroxazolyl. 29 、n 30 and n 31are the same or different, and are independently selected from any one of 0 and 1.

[0029] In some embodiments, in the second light-emitting device, a mass ratio between the first host material and the second host material is greater than or equal to 3:7 and less than or equal to 1:1.

[0030] In some embodiments, when the guest material of the light-emitting layer of the first light-emitting device is selected from any one of the structures represented by general formula (I), at least one of R1, R2, R3, R4 and R5 contains deuterium; and / or,

[0031] In the case where the first host material of the light-emitting layer of the first light-emitting device is selected from any one of the structures shown in general formula (III), L1, L2, R 11 、R 12 、R 13 、R 14 、R 15 and R 16 at least one of which contains deuterium; and / or

[0032] In the case where the second host material of the light-emitting layer of the first light-emitting device is selected from any one of the structures shown in general formula (IV), L3, L4, R 17 、R 18 、R 19 、R 20 、R 21 and R 22 at least one of which contains deuterium; and / or

[0033] In the case where the guest material of the light-emitting layer of the second light-emitting device is selected from any one of the structures represented by formula (II) or formula (II-A), Ar1, R6, R7, R8, R9 and R 10 at least one of which contains deuterium; and / or

[0034] In the case where the first host material of the light-emitting layer of the second light-emitting device is selected from any one of the structures shown in general formula (V), R 23 、R 24 、R 25 、R 26 、R 27 and R 28 at least one of which contains deuterium; and / or

[0035] In the case where the second host material of the light-emitting layer of the second light-emitting device is selected from any one of the structures shown in general formula (VI), L5, L6, L7, R 29 、R 30 and R 31 At least one of them contains deuterium.

[0036] In some embodiments, the half-maximum width of the spectrum of light emitted by the light-emitting layer of the second light-emitting device is smaller than the half-maximum width of the spectrum of light emitted by the light-emitting layer of the first light-emitting device.

[0037] In another aspect, a display panel is provided. The display panel includes: a light-emitting substrate as described in any of the above embodiments; and a plurality of pixel driving circuits. Each of the plurality of pixel driving circuits is electrically connected to a light-emitting device and is configured to drive the light-emitting device to emit light.

[0038] In another aspect, a display device is provided, comprising: a display panel as described in any one of the above embodiments and a driver chip, wherein the driver chip is configured to drive the display panel to display. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] To more clearly illustrate the technical solutions of the present disclosure, the following briefly introduces the drawings required for use in some embodiments of the present disclosure. Obviously, the drawings described below are only drawings of some embodiments of the present disclosure, and those skilled in the art can also derive other drawings based on these drawings. Furthermore, the drawings described below are schematic diagrams and do not limit the actual dimensions of the products, actual processes of the methods, actual timing of signals, etc. involved in the embodiments of the present disclosure.

[0040] FIG1 is a structural diagram of a display device according to some embodiments;

[0041] FIG2 is a structural diagram of a display panel according to some embodiments;

[0042] FIG3 is a structural diagram of a light-emitting substrate according to some embodiments;

[0043] FIG4 is a structural diagram of a light-emitting substrate according to some further embodiments;

[0044] FIG5 is a structural diagram of a light-emitting substrate according to some further embodiments;

[0045] FIG6 is a comparison diagram of exciton recombination regions according to some embodiments;

[0046] FIG7 is a comparison diagram of the highest occupied molecular orbital energy level and the lowest unoccupied molecular orbital energy level according to some embodiments;

[0047] FIG8 is a structural diagram of a light-emitting substrate according to some further embodiments;

[0048] FIG9 is a structural diagram of a light-emitting substrate according to some other embodiments;

[0049] FIG10 is a graph showing a change in normalized exciton intensity versus exciton recombination area according to some embodiments;

[0050] FIG. 11 is a diagram illustrating an energy transfer process according to some embodiments. DETAILED DESCRIPTION

[0051] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present disclosure. Obviously, the embodiments described are only some embodiments of the present disclosure, not all embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of the present disclosure.

[0052] Unless the context requires otherwise, throughout the specification and claims, the term "comprise" and its other forms, such as the third person singular form "comprises" and the present participle form "comprising", are to be interpreted as open and inclusive, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "example", "specific example" or "some examples" are intended to indicate that the particular features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the particular features, structures, materials or characteristics may be included in any one or more embodiments or examples in any appropriate manner.

[0053] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, "plurality" means two or more.

[0054] “At least one of A, B and C” has the same meaning as “at least one of A, B or C” and both include the following combinations of A, B and C: A only, B only, C only, the combination of A and B, the combination of A and C, the combination of B and C, and the combination of A, B and C.

[0055] “A and / or B” includes the following three combinations: A only, B only, and a combination of A and B.

[0056] As used herein, "about," "substantially," or "approximately" includes the stated value and an average value that is within an acceptable range of deviation from the particular value as determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

[0057] As used herein, "parallel", "perpendicular", and "equal" include the situations described and situations similar to the situations described, and the range of the similar situations is within an acceptable deviation range, wherein the acceptable deviation range is as determined by a person of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of the specific quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, wherein the acceptable deviation range of approximate parallelism can be, for example, a deviation within 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, wherein the acceptable deviation range of approximate perpendicularity can also be, for example, a deviation within 5°. "Equal" includes absolute equality and approximate equality, wherein the acceptable deviation range of approximate equality can be, for example, that the difference between the two equals is less than or equal to 5% of either one.

[0058] It will be understood that when a layer or element is referred to as being on another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may be present therebetween.

[0059] Exemplary embodiments are described herein with reference to cross-sectional and / or plan views that are idealized exemplary drawings. In the drawings, the thickness of layers and the area of ​​regions are exaggerated for clarity. Therefore, variations in shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are contemplated. Therefore, the exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but rather include deviations in shape due to, for example, manufacturing. For example, an etched region shown as a rectangle will typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the actual shape of regions of the device and are not intended to limit the scope of the exemplary embodiments.

[0060] It should be noted that, for example, 11-1 in the drawings of this disclosure indicates that component 11 belongs to component 1, and for example, 220-200 in FIG2 indicates that the light-emitting functional layer 220 belongs to the light-emitting substrate 200. Other similar reference numerals in the drawings also follow the above description. For example, 1 / 2 in the drawings of this disclosure indicates that both structure 1 and structure 2 can refer to this structure, and for example, 101 / 100 in FIG3 indicates that both the first light-emitting device 100 and the light-emitting device 101 can refer to this structure. Other similar reference numerals in the drawings also follow the above description.

[0061] As shown in FIG. 1 , some embodiments of the present disclosure provide a display device 400 , which includes a display panel 300 .

[0062] In some examples, the display device 400 may be, for example, an OLED (Organic Light Emitting Diode) display device 400 .

[0063] 1 , the display device 400 further includes a driver chip 410. The driver chip 410 is used to drive the display panel 300 to perform display.

[0064] In addition, the display device 400 may also include an under-screen camera and an under-screen fingerprint recognition sensor, so that the display device 400 can realize various functions such as taking pictures, recording videos, fingerprint recognition or face recognition.

[0065] The display device 400 can be any display device 400 that displays either motion (e.g., video) or fixed (e.g., still images) and text or images. More specifically, it is contemplated that the display device 400 of the embodiments described can be implemented in or associated with a variety of electronic devices, such as (but not limited to) mobile phones, wireless devices, personal data assistants (PDAs), handheld or portable computers, GPS receivers / navigators, cameras, MP4 video players, video cameras, game consoles, watches, clocks, calculators, television monitors, flat-panel displays, computer monitors, automotive displays (e.g., speedometer displays, etc.), navigation systems, cockpit controls and / or displays, displays of camera views (e.g., displays of rearview cameras in vehicles), electronic photographs, electronic billboards or signs, projectors, architectural structures, packaging, and aesthetic structures (e.g., displays of images of a piece of jewelry), etc.

[0066] In some embodiments, as shown in FIG2 , the display panel 300 includes a light-emitting substrate 200. In some examples, the light-emitting substrate 200 includes a substrate 210 and a light-emitting functional layer 220 disposed on the substrate 210. The light-emitting functional layer 220 includes a plurality of light-emitting devices 100. The plurality of light-emitting devices 100 are arranged along a first direction X, and the first direction X is parallel to the plane of the substrate 210.

[0067] In some examples, as shown in FIG2 , the display panel 300 further includes an array layer 310 disposed between the substrate 210 and the light-emitting functional layer 220. The array layer 310 includes a plurality of pixel driving circuits 311, wherein the pixel driving circuits 311 include a plurality of transistors TFT. Each pixel driving circuit 311 is electrically connected to a light-emitting device 100 to drive the light-emitting device 100 to emit light.

[0068] 2 , multiple pixel driving circuits 311 and multiple light emitting devices 100 may be coupled in a one-to-one correspondence. In other examples, one pixel driving circuit 311 may be coupled to multiple light emitting devices 100 , or multiple pixel driving circuits 311 may be coupled to one light emitting device 100 .

[0069] For example, in the display panel 300, the pixel driving circuit 311 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 311. The light emitted by multiple light-emitting devices 100 cooperates with each other, thereby enabling the display panel 300 to achieve a display function.

[0070] In some examples, as shown in Figure 2, the display panel 300 also includes an encapsulation layer 320, and the array layer 310, the light-emitting functional layer 220 and the encapsulation layer 320 are stacked on the substrate 210, and the array layer 310, the light-emitting functional layer 220 and the encapsulation layer 320 are arranged in sequence in a direction away from the substrate 210.

[0071] Exemplarily, the display panel 300 can be an OLED (Organic Light Emitting Diode) display panel 300. In this case, the encapsulation layer 320 covers the light-emitting device 100, encapsulating the light-emitting device 100 to prevent water vapor and oxygen in the external environment from entering the display panel 300, damaging the organic material in the light-emitting device 100 and shortening the life of the OLED display panel 300.

[0072] In some embodiments, as shown in Figures 2 and 3, in the light-emitting substrate 200, the light-emitting functional layer 220 also includes a pixel defining layer 221 arranged on one side of the substrate 210, and the pixel defining layer 221 has multiple openings Q. Multiple light-emitting devices 100 can be arranged one-to-one corresponding to the multiple openings Q.

[0073] In some embodiments, as shown in Figures 3 to 5, the plurality of light-emitting devices 100 of the light-emitting substrate 200 include a first light-emitting device 101, a second light-emitting device 102, and a third light-emitting device 103. Under the action of a driving voltage, the first light-emitting device 101 is configured to emit light of a first wavelength, which is green light, the second light-emitting device 102 is configured to emit light of a second wavelength, which is red light, and the third light-emitting device 103 is configured to emit light of a third wavelength, which is blue light.

[0074] By setting up multiple light-emitting devices 100 including a first light-emitting device 101, a second light-emitting device 102 and a third light-emitting device 103, the brightness (grayscale) of the first light-emitting device 101, the second light-emitting device 102 and the third light-emitting device 103 can be adjusted respectively, and the display of multiple colors can be achieved through color combination and superposition, thereby realizing full-color display of the display panel 300.

[0075] It should be noted that Figures 4 to 5 are simplified schematic diagrams obtained after removing other film layers in the light-emitting substrate 200 except for the film layers related to the light-emitting device 100. In Figures 4 to 5, the multiple light-emitting devices 100 are, for example, a first light-emitting device 101, a second light-emitting device 102 and a third light-emitting device 103.

[0076] In some embodiments, each of the plurality of light emitting devices 100 includes an anode 110 and a cathode 120 disposed opposite to each other, and a light emitting layer 130 disposed between the anode 110 and the cathode 120. The anode 110 and the cathode 120 are stacked along a second direction Y that intersects the first direction X.

[0077] Exemplarily, as shown in FIG. 4 and FIG. 5 , the second direction Y is perpendicular to the first direction X.

[0078] In some examples, the anode 110 may be located on a side of the light-emitting layer 130 away from the substrate 210, and the cathode 120 may be located on a side of the light-emitting layer 130 close to the substrate 210. In other examples, the anode 110 may be located on a side of the light-emitting layer 130 close to the substrate 210, and the cathode 120 may be located on a side of the light-emitting layer 130 away from the substrate 210. During operation, a voltage is applied to the anode 110 and the cathode 120, respectively, to generate an electric field therebetween, which can drive the holes in the anode 110 and the electrons in the cathode 120 to recombine in the light-emitting layer 130, thereby emitting light.

[0079] For example, in order to ensure that the light-emitting device 100 can effectively emit light, the anode 110 can be made of a material with a high work function, such as a material with a work function greater than 6 eV; the cathode 120 can be made of a material with a low work function, such as a material with a work function less than a set value, and the set value can range from 2.0 eV to 3.0 eV. In this way, the holes in the anode and the electrons in the cathode can effectively migrate to the light-emitting layer 130 under the drive of the electric field, thereby compounding and emitting light.

[0080] In some examples, the material of the anode 110 may be a transparent conductive metal oxide material, for example, the material of the anode 110 may be indium tin oxide (ITO) or indium zinc oxide (IZO); or, the material of the anode 110 may be a composite layer structure of metal / conductive metal oxide, for example, the material of the anode 110 may be a silver / indium tin oxide composite layer structure or a silver / indium zinc oxide composite layer structure.

[0081] In some examples, the material of cathode 120 may be a metal material, for example, the material of cathode 120 may be magnesium, silver, aluminum, or a magnesium-silver alloy.

[0082] In some embodiments, as shown in Figures 8 and 9 , a cathode cover layer 160 is further disposed between the encapsulation layer 320 and the cathode 120 in the light-emitting substrate 200. The material forming the cathode cover layer 160 is, for example, a material with a high refractive index. By providing the cathode cover layer 160, the high refractive index of the material can be utilized to improve the light extraction efficiency of the light-emitting device, thereby increasing the efficiency and brightness of the light-emitting device 100 when illuminated.

[0083] It should be noted that Figures 8 and 9 are simplified schematic diagrams obtained after removing the other film layers in the light-emitting substrate 200 except the film layers related to the light-emitting device 100. In Figure 8, the multiple light-emitting devices 100 are, for example, the first light-emitting device 101; in Figure 9, the multiple light-emitting devices 100 are, for example, the second light-emitting device 102.

[0084] In some embodiments, as shown in Figures 4 and 5, in order to improve the luminous efficiency of the light-emitting device 100, a hole transport functional layer 140 is provided between the anode 110 and the light-emitting layer 130. The hole transport functional layer 140, for example, includes at least one of a stacked hole injection layer 141 (Hole Inject Layer, HIL) and a hole transport layer (HTL). The hole transport layer (HTL) may include at least one of a first hole transport layer 142 and a second hole transport layer 143. When the hole transport functional layer 140 includes a hole injection layer 141, a first hole transport layer 142, and a second hole transport layer 143, the hole injection layer 141, the first hole transport layer 142, and the second hole transport layer 143 are arranged in sequence in a direction away from the anode 110.

[0085] In some embodiments, to improve the luminous efficiency of the light-emitting device 100, an electron transport functional layer 150 is provided between the cathode 120 and the light-emitting layer 130. The electron transport functional layer 150, for example, includes at least one of a stacked electron injection layer 151 (Electron Inject Layer, EIL), an electron transport layer 152 (Electron Transport Layer, ETL), and a hole blocking layer 153 (Hole Blocking Layer, EBL). When the electron transport functional layer 150 includes the electron injection layer 151, the electron transport layer 152, and the hole blocking layer 153, the electron injection layer 151, the electron transport layer 152, and the hole blocking layer 153 are arranged in sequence in a direction away from the cathode 120.

[0086] By setting up the film layers such as the hole injection layer 141, the first hole transport layer 142, the second hole transport layer 143, the electron injection layer 151, the electron transport layer 152, and the hole blocking layer 153, it is equivalent to setting up transition steps between the anode 110 and the light-emitting layer 130, and between the cathode 120 and the light-emitting layer 130, thereby reducing the potential barrier height that needs to be overcome for carrier transition, thereby making the light-emitting efficiency higher.

[0087] Exemplarily, the hole transport functional layer 140 is configured to transport holes and / or block electrons or excitons. For example, the hole injection layer 141 can be configured to reduce the hole injection barrier and improve the hole injection efficiency. The first hole transport layer 142 can be configured to transport holes. The second hole transport layer 143 can be configured to transport holes and block electrons and excitons generated in the light-emitting layer 130.

[0088] For example, the electron transport functional layer 150 is configured to transport electrons and / or block holes or excitons. For example, the hole blocking layer 153 can be configured to block holes and excitons generated in the light emitting layer 130 .

[0089] In some embodiments, the cathode 120 stacked with each light-emitting layer 130 is a structure that is interconnected throughout the entire layer, that is, the cathode 120 can be a common electrode shared by multiple light-emitting devices 100. The hole injection layer 141 stacked with each light-emitting layer 130 can also be a structure that is interconnected throughout the entire layer, that is, the hole injection layer 141 can be a common film layer shared by multiple light-emitting devices 100. The first hole transport layer 142, the second hole transport layer 143, the hole blocking layer 153, the electron injection layer 151, and the electron transport layer 152 can also be common film layers shared by multiple light-emitting devices 100.

[0090] For example, as shown in FIG. 3 , when the cathode 120 is a common electrode shared by a plurality of light-emitting devices 100 , the cathode 120 is simultaneously formed on a side of the pixel defining layer 221 away from the substrate 210 .

[0091] In other embodiments, as shown in FIG5 , the second hole transport layers 143 of the first light-emitting device 101 , the second light-emitting device 102 , and the third light-emitting device 103 are independently provided. Thus, the material of the second hole transport layer 143 with matching performance can be selected as needed according to the different materials of the light-emitting layer 130 .

[0092] In some embodiments, the material of the light emitting layer 130 of each of the plurality of light emitting devices 100 includes a guest material D. The guest material D is configured to emit light of a set wavelength.

[0093] Exemplarily, the light of the set wavelength may be green light; or red light; or blue light.

[0094] It is understood that the guest material D is the material in the light emitting layer 130 that emits light.

[0095] In some examples, the guest material D is a fluorescent material that can emit light using singlet excitons; in other examples, the guest material D is a phosphorescent material or a delayed fluorescent material that can emit light using triplet excitons.

[0096] In some embodiments, the material of the light emitting layer 130 of each of the plurality of light emitting devices 100 further includes a host material, and the host material includes a first host material HP and a second host material HN.

[0097] For example, the first host material HP can be configured to transport holes and / or to form excitons with recombined electrons and holes, and transfer fluorescence resonance energy to the guest material D. In this case, the hole mobility of the first host material HP is greater than or equal to the hole mobility of the second host material HN.

[0098] Exemplarily, the second host material HN can be configured to: transport electrons, and / or recombine electrons and holes to form excitons, and transfer fluorescence resonance energy to the guest material D. In this case, the electron mobility of the second host material HN is greater than or equal to the electron mobility of the first host material HP.

[0099] Exemplarily, when the material of the light-emitting layer 130 of each light-emitting device 100 also includes a first host material HP and a second host material HN, the guest material D can be configured to: emit photons using energy obtained by fluorescence resonance energy transfer of the first host material HP and / or the second host material HN, and / or, to form excitons by recombining electrons and holes.

[0100] As mentioned in the background, OLED technology is gaining increasing attention in academia and industry within the field of organic semiconductors, and has been successfully applied in commercial flat-panel displays and lighting. OLED light-emitting devices are self-luminous, and accordingly, OLED display panels and OLED light-emitting substrates require no backlight, resulting in thin panels and light weight. OLED light-emitting devices also offer the advantages of being fully solid-state, with fast response times and a wide operating temperature range.

[0101] The different compositions of the compounds used in the organic material layers of OLED light-emitting devices can significantly impact the overall performance of the devices. With the development of OLED light-emitting devices, the requirements for their efficiency, lifespan, power consumption, color purity, and other performance characteristics are becoming increasingly stringent. Existing organic materials are no longer able to meet these requirements.

[0102] In the related art, a ligand material refers to a material with a ligand and a central atom in its structure, and the ligand and the central atom are connected by a coordination bond, wherein a ligand (also called a ligand) represents an atom, molecule, or ion that can form a bond with a central atom (metal or metalloid). When a ligand and a central atom are connected by N coordination bonds, the ligand is called an N-dentate ligand. For example, a bidentate ligand refers to a ligand connected to a central atom by two coordination bonds, and a bidentate ligand material refers to a ligand material that contains at least one bidentate ligand in its structure.

[0103] In some implementations, guest material D is a phosphorescent material and a bidentate ligand material, i.e., a material containing a bidentate ligand, such as a guest material having the structures shown in the following formulas (R-GD) and (R-RD). In formulas (R-GD) and (R-RD), the central atom is iridium (Ir), and the central atom is bonded to three bidentate ligands via ligand bonds. As can be seen from the structures shown in formulas (R-GD) and (R-RD), when guest material D is a bidentate ligand material, the molecular rigidity of guest material D is relatively low and the degree of freedom is relatively large, thereby increasing the vibration and rotation of the ligand.

[0104] Based on this, some embodiments of the present disclosure provide a light-emitting substrate 200. The guest material D of the light-emitting layer 130 of at least one light-emitting device 100 among the plurality of light-emitting devices 100 is a tetradentate ligand material.

[0105] As can be seen from the above, when the guest material D is a tetradentate ligand material, its structure contains at least one tetradentate ligand, and the tetradentate ligand is bonded to the central atom via a ligand bond. Here, the central atom can be a metal or a metalloid, and this is not a limitation. In this case, the guest material D is a phosphorescent material.

[0106] Exemplarily, the central atom of the guest material D is platinum (Pt), that is, the guest material D is a ligand material having platinum as the central atom and containing at least one tetradentate ligand.

[0107] It can be understood that, compared to the case where the guest material is a bidentate ligand material in some implementations, the tetradentate ligand design is relatively more reasonable, and can provide a suitable coordination position for the central atom of the phosphorescent material (for example, platinum), so that the molecular rigidity of the guest material is relatively high. In this way, first, the degree of freedom of the guest material D can be made relatively small, the vibration and rotation of the tetradentate ligand can be reduced, the metal-to-ligand charge transfer (MLCT) of the ligand material and the non-radiative attenuation caused by the ligand center (LC) transition can be reduced, the proportion of radiative transition can be increased, and the luminous efficiency of the light-emitting device 100 can be effectively improved. Second, the tetradentate ligand can maintain a square planar configuration, so that the orientation of the guest material D is improved, so that more molecules in the guest material D can emit light in a direction perpendicular to the substrate, which can increase the light extraction efficiency of the guest material D and effectively improve the luminous efficiency of the light-emitting device 100. Third, when the molecular rigidity of the guest material D is relatively high, the amplitude of the molecular torsional motion can be reduced, resulting in relatively less bond breakage caused by the molecular torsional motion, thereby improving the stability of the guest material D and effectively increasing the service life of the light-emitting device 100. Fourth, when the molecular rigidity of the guest material D is relatively high, the molecular deformation in the excited state is relatively small, and the corresponding triplet state split energy levels are relatively small. This results in a relatively narrow wavelength band when the guest material D emits light using triplet excitons, resulting in a relatively narrow peak in the emission spectrum of the light-emitting layer 130, effectively improving the color purity of the light-emitting device 100.

[0108] It can be seen that by setting the guest material D of the light-emitting layer 130 of at least one light-emitting device 100 among the multiple light-emitting devices 100 as a tetradentate ligand material, the luminous efficiency, service life, and color purity of at least one light-emitting device 100 among the multiple light-emitting devices 100 can be improved.

[0109] In some embodiments, in at least one light-emitting device 100 among the plurality of light-emitting devices 100, the difference between the triplet energy level T1(HP) of the first host material HP and the triplet energy level T1(D) of the guest material D is greater than or equal to 0.2 eV and less than or equal to 0.5 eV; and the difference between the triplet energy level T1(HN) of the second host material HN and the triplet energy level T1(D) of the guest material D is greater than or equal to 0.2 eV and less than or equal to 0.5 eV. That is, 0.2 eV ≤ T1(HP)-T1(D) ≤ 0.5 eV, and 0.2 eV ≤ T1(HN)-T1(D) ≤ 0.5 eV.

[0110] It is understood that when the light-emitting device 100 emits light, the first host material HP and the second host material HN can form an exciplex HP / HN. Furthermore, the triplet energy level T1(HP / HN) of the exciplex HP / HN is lower than the triplet energy level T1(HP) of the first host material HP and lower than the triplet energy level T1(HN) of the second host material HN. Therefore, through the above configuration, on the one hand, the triplet energy level T1(HP) of the first host material HP and the triplet energy level T1(HN) of the second host material HN can both be higher than the triplet energy level T1(D) of the guest material D. Thus, the triplet energy level T1(HP / HN) of the exciplex HP / HN can be higher than the triplet energy level T1(D) of the guest material D, enabling energy transfer from the exciplex HP / HN to the guest material D. This can prevent exciton quenching caused by exciton backflow during energy transfer, thereby improving the efficiency of the light-emitting device 100. On the other hand, the difference between the triplet energy level T1(HP / HN) of the excited complex HP / HN and the triplet energy level T1(D) of the guest material D can be made relatively small, thereby improving the energy transfer efficiency, enhancing the adequacy of energy transmission, and improving the efficiency of the light-emitting device 100.

[0111] Illustratively, in at least one light-emitting device 100 among the plurality of light-emitting devices 100, the difference between the triplet energy level T1(HP) of the first host material HP and the triplet energy level T1(D) of the guest material D may be 0.2eV, 0.3eV, 0.4eV, 0.45eV or 0.5eV, etc.

[0112] Illustratively, in at least one light-emitting device 100 among the plurality of light-emitting devices 100, the difference between the triplet energy level T1(HN) of the second host material HN and the triplet energy level T1(D) of the guest material D may be 0.2 eV, 0.3 eV, 0.35 eV, 0.4 eV or 0.5 eV, etc.

[0113] Here, among the multiple light-emitting devices 100, a light-emitting device 100 in which the guest material D of the light-emitting layer 130 is a tetradentate ligand material is defined as light-emitting device 100A. Among the multiple light-emitting devices 100, a light-emitting device 100 that satisfies 0.2 eV ≤ T1(HP) - T1(D) ≤ 0.5 eV and 0.2 eV ≤ T1(HN) - T1(D) ≤ 0.5 eV is defined as light-emitting device 100B. It should be noted that the at least one light-emitting device 100A and the at least one light-emitting device 100B can be the same light-emitting device 100 or different light-emitting devices 100.

[0114] In some embodiments, in the light-emitting layer 130 of at least one light-emitting device 100 among the plurality of light-emitting devices 100 , the region where holes and electrons recombine to form excitons is located on a side close to the hole transport functional layer.

[0115] In the related art, in some light-emitting devices 100, the material PR in the hole transport functional layer 140 close to the light-emitting layer 130 (for example, the second hole transport layer 143) can form an exciton complex PR / HN with the second main material HN, and holes and electrons can recombine on the exciton complex PR / HN to form excitons.

[0116] It can be understood that, as shown in FIG6 , when the region where holes and electrons recombine to form excitons is located on the side close to the hole transport functional layer (such as the K1 position shown in FIG6 ), compared to the case where the region where holes and electrons recombine to form excitons is located in the middle of the light-emitting layer 130 (such as the K2 position shown in FIG6 ), holes and electrons can recombine to form excitons not only on the exciplex HP / HN but also on the exciplex PR / HN. In this way, energy utilization can be improved, thereby improving the efficiency of the light-emitting device 100. Therefore, by configuring the region where holes and electrons recombine to form excitons in the light-emitting layer 130 of at least one light-emitting device 100 among the multiple light-emitting devices 100 to be close to the hole transport functional layer 140, the luminous efficiency of at least one light-emitting device 100 among the multiple light-emitting devices 100 can be improved.

[0117] Here, among the multiple light-emitting devices 100, a light-emitting device 100 in which the region where holes and electrons in the light-emitting layer 130 recombine to form excitons is located on the side close to the hole transport functional layer 140 is defined as a light-emitting device 100C. It should be noted that three or any two of the at least one light-emitting device 100A, the at least one light-emitting device 100B, and the at least one light-emitting device 100C may be the same light-emitting device 100 or different light-emitting devices 100.

[0118] In some embodiments, in at least one light-emitting device 100 among the plurality of light-emitting devices 100, the absolute value of the difference between the highest occupied molecular orbital energy level HOMO(HP) of the first host material HP and the highest occupied molecular orbital energy level HOMO(D) of the guest material D is greater than or equal to 0.4 eV; and the absolute value of the difference between the lowest unoccupied molecular orbital energy level LUMO(HN) of the second host material HN and the lowest unoccupied molecular orbital energy level LUMO(D) of the guest material D is greater than or equal to 0.1 eV. In other words, |HOMO(HP)-HOMO(D)|≥0.4 eV, and |LUMO(HN)-LUMO(D)|≥0.1 eV.

[0119] It can be understood that when |HOMO(HP)-HOMO(D)|≥0.4eV, the absolute value of the difference between the highest occupied molecular orbital energy level HOMO(HP) of the first host material HP and the highest occupied molecular orbital energy level HOMO(D) of the guest material D is relatively large, and accordingly, deeper hole traps are easily generated on the first host material HP. The hole transport performance can be relatively low. Thus, on the one hand, holes can be more easily captured by the host material (for example, one or more of the first host material HP, the second host material HN, and the exciplex HP / HN formed by the first host material and the second host material), which can increase the probability of holes and electrons recombining to form excitons, improve the energy utilization rate, and improve the efficiency of the light-emitting device 100; on the other hand, due to the relatively low hole transport performance, the region where holes and electrons recombining to form excitons can be located on the side close to the hole transport functional layer. Thus, holes and electrons can recombined to form excitons on the exciplex HP / HN, or they can recombined to form excitons on the exciplex PR / HN, which can improve the energy utilization rate and improve the efficiency of the light-emitting device 100.

[0120] Exemplarily, in at least one light-emitting device 100 among the multiple light-emitting devices 100, the absolute value of the difference between the highest occupied molecular orbital energy level HOMO (HP) of the first host material HP and the highest occupied molecular orbital energy level HOMO (D) of the guest material D can be 0.4 eV, 0.45 eV, 0.5 eV, 0.6 eV or 0.7 eV, etc.

[0121] Illustratively, in at least one light-emitting device 100 among the plurality of light-emitting devices 100, the absolute value of the difference between the lowest unoccupied molecular orbital energy level LUMO(HN) of the second host material HN and the lowest unoccupied molecular orbital energy level LUMO(D) of the guest material D may be 0.1eV, 0.15eV, 0.2eV, 0.25eV or 0.3eV, etc.

[0122] Here, among the multiple light-emitting devices 100, a light-emitting device 100 that satisfies |HOMO(HP)-HOMO(D)| ≥ 0.4 eV and |LUMO(HN)-LUMO(D)| ≥ 0.1 eV is defined as a light-emitting device 100D. It should be noted that any four, any three, or any two of the at least one light-emitting device 100A, the at least one light-emitting device 100B, the at least one light-emitting device 100C, and the at least one light-emitting device 100D may be the same light-emitting device 100 or different light-emitting devices 100.

[0123] In some examples, at least one of the multiple light-emitting devices 100 satisfies the following conditions: the guest material D of the light-emitting layer 130 is a tetradentate ligand material; and the region in the light-emitting layer 130 where holes and electrons recombine to form excitons is located on a side close to the hole transport functional layer; at the same time, the absolute value of the difference between the highest occupied molecular orbital energy level HOMO (HP) of the first host material HP and the highest occupied molecular orbital energy level HOMO (D) of the guest material D is greater than or equal to 0.4 eV; and the absolute value of the difference between the lowest unoccupied molecular orbital energy level LUMO (HN) of the second host material HN and the lowest unoccupied molecular orbital energy level LUMO (D) of the guest material D is greater than or equal to 0.1 eV.

[0124] In order to illustrate the changes in the highest occupied molecular orbital energy level and the lowest unoccupied molecular orbital energy level when the guest material GD of the light-emitting layer 130 of the light-emitting device 100 is a tetradentate ligand material, taking the first light-emitting device 101 as an example, when the guest material D of the first light-emitting device 101 is a tetradentate ligand material (GD shown in the figure) and a bidentate ligand material (R-GD shown in the figure), the highest occupied molecular orbital energy level HOMO and the lowest unoccupied molecular orbital energy level LUMO of the first host material HP, the second host material HN and the guest material D in the light-emitting layer 130 are schematically compared, and the results are shown in Figure 7.

[0125] It should be noted that the upper edge of the box outside each material in Figure 7 represents the highest occupied molecular orbital (HOMO) energy level of that material, and the lower edge represents the lowest unoccupied molecular orbital (LUMO) energy level of that material. The left and right edges are for schematic packaging purposes and have no practical meaning. The left-right arrangement of guest material GD and guest material R-GD in Figure 9 is to more clearly illustrate the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of the two materials and has no practical meaning.

[0126] As shown in Figure 7, the absolute value of the difference between the highest occupied molecular orbital energy level HOMO(GHP) of the first host material GHP and the highest occupied molecular orbital energy level HOMO(GD) of the guest material GD, |HOMO(GHP)-HOMO(GD)|, is greater than the absolute value of the difference between the highest occupied molecular orbital energy level HOMO(GHP) of the first host material GHP and the highest occupied molecular orbital energy level HOMO(R-GD) of the guest material R-GD, |HOMO(GHP)-HOMO(R-GD)|.

[0127] In some embodiments, in at least one light-emitting device 100 among the plurality of light-emitting devices 100 , an orientation parameter S of the guest material D in the host material is greater than or equal to −0.40 and less than or equal to −0.10. That is, −0.40 ≤ S ≤ −0.10.

[0128] In related art, the orientation parameter S can be used to characterize the anisotropy of the transition dipole moment vectors (TDMVs) of a molecule. The orientation parameter S can be calculated using the following formula:

[0129] Where, <cos 2 θ> is the anisotropy factor, which represents the quadratic average of the TDMV projections of the molecular system, with each molecule carrying only one different TDMV relative to the surface normal. Therefore, when the molecules are perfectly aligned horizontally, <cos 2 θ>=0,and S=-0.5;when the molecules are isotropically distributed, <cos 2 θ>=0.33,and S=0;when the molecules are arranged in a vertical direction, <cos 2 θ>=1, and S=1.

[0130] The orientation parameter S of the guest material D in the host material is greater than or equal to -0.40 and less than or equal to -0.10, which can result in a relatively large number of horizontally oriented molecules in the guest material D. Since horizontally oriented molecules can emit light perpendicular to the substrate, this provides a better light-emission direction and higher light-extraction efficiency. Setting the orientation parameter S of the guest material D in the host material to be greater than or equal to -0.40 and less than or equal to -0.10 can optimize the light-emission direction of the guest material D in the light-emitting layer 130, improve the light-extraction efficiency of the light-emitting device 100, and thereby enhance the luminous efficiency of the light-emitting device 100. Therefore, when, in at least one of the multiple light-emitting devices 100, the orientation parameter S of the guest material D in the host material is greater than or equal to -0.40 and less than or equal to -0.10, the luminous efficiency of the at least one of the multiple light-emitting devices 100 can be enhanced.

[0131] For example, in at least one light-emitting device 100 among the plurality of light-emitting devices 100 , the orientation parameter S of the guest material D in the host material may be −0.40, −0.30, −0.25, −0.20, or −0.10.

[0132] Here, among the plurality of light-emitting devices 100, a light-emitting device 100 that satisfies an orientation parameter S of the guest material D in the host material greater than or equal to -0.40 and less than or equal to -0.10 is defined as a light-emitting device 100E. It should be noted that any five, any four, any three, or any two of the at least one light-emitting device 100A, the at least one light-emitting device 100B, the at least one light-emitting device 100C, the at least one light-emitting device 100D, and the at least one light-emitting device 100E may be the same light-emitting device 100 or different light-emitting devices 100.

[0133] In some examples, the guest material D of the light-emitting layer 130 of at least one light-emitting device 100 among the plurality of light-emitting devices 100 is a tetradentate ligand material; and the orientation parameter S of the guest material D of the light-emitting device 100 in the host material is greater than or equal to -0.40 and less than or equal to -0.10.

[0134] It can be understood that when the guest material D is a tetradentate ligand material, the molecular rigidity of the guest material D can be made relatively high, and the tetradentate ligand can maintain a square planar configuration, so that the orientation of the guest material D is improved, so that more molecules in the guest material D can emit light in a direction perpendicular to the substrate, which can increase the light extraction efficiency of the guest material D and effectively improve the luminous efficiency of the light-emitting device 100.

[0135] In some embodiments, the light emitting layer 130 of at least one light emitting device 100 among the plurality of light emitting devices 100 emits light with a half-maximum width λ greater than or equal to 20 nm and less than or equal to 30 nm, that is, 20 nm ≤ λ ≤ 30 nm.

[0136] It is understood that when the half-maximum width λ of the spectrum of light emitted by the light-emitting layer 130 of the light-emitting device 100 is greater than or equal to 20 nm and less than or equal to 30 nm, the light emitted by the light-emitting layer 130 of the light-emitting device 100 has higher color purity, which can improve the display performance of the light-emitting substrate 200. Therefore, by configuring the light-emitting layer 130 of at least one light-emitting device 100 among the multiple light-emitting devices 100 to emit light with a half-maximum width λ of the spectrum greater than or equal to 20 nm and less than or equal to 30 nm, the light emitted by the light-emitting layer 130 of at least one light-emitting device 100 among the multiple light-emitting devices 100 has higher color purity.

[0137] For example, the half-maximum width λ of the spectrum of light emitted by the light-emitting layer 130 of at least one light-emitting device 100 among the plurality of light-emitting devices 100 may be 20 nm, 22 nm, 24 nm, 27 nm or 30 nm.

[0138] Here, among the plurality of light-emitting devices 100, a light-emitting device 100 having a half-maximum width λ of the emitted light spectrum greater than or equal to 20 nm and less than or equal to 30 nm is defined as a light-emitting device 100F. It should be noted that any six, any five, any four, any three, or any two of the at least one light-emitting device 100A, the at least one light-emitting device 100B, the at least one light-emitting device 100C, the at least one light-emitting device 100D, the at least one light-emitting device 100E, and the at least one light-emitting device 100F may be the same light-emitting device 100 or different light-emitting devices 100.

[0139] In some examples, the guest material D of the light-emitting layer 130 of at least one light-emitting device 100 among the multiple light-emitting devices 100 is a tetradentate ligand material; and the light-emitting layer 130 of the light-emitting device 100 has a half-peak width λ of the spectrum of light emitted that is greater than or equal to 20 nm and less than or equal to 30 nm.

[0140] It can be understood that when the guest material D is a tetradentate ligand material, the molecular rigidity of the guest material D can be made relatively high, so that the deformation of the molecule in the excited state can be made relatively small, and the corresponding triplet split energy levels can be relatively small. When the guest material D utilizes triplet excitons to emit light, the corresponding wavelength band is relatively narrow, and the peak of the emission spectrum of the light-emitting layer 130 is relatively narrow, and the color purity of the light-emitting device 100 can be effectively improved.

[0141] In some embodiments, when the plurality of light-emitting devices 100 includes a first light-emitting device 101, a second light-emitting device 102, and a third light-emitting device 103, the half-maximum width λ2 of the spectrum of light emitted by the light-emitting layer 130 of the second light-emitting device 102 is smaller than the half-maximum width λ1 of the spectrum of light emitted by the light-emitting layer 130 of the first light-emitting device 101. In other words, λ2<λ1.

[0142] When the guest material GD of the light-emitting layer 130 of the first light-emitting device 101 and the guest material RD of the light-emitting layer 130 of the second light-emitting device 102 are both tetradentate ligand materials with platinum as the central atom (i.e., phosphorescent materials containing tetradentate ligands), the half-maximum width λ2 of the spectrum of light emitted by the light-emitting layer 130 of the second light-emitting device 102 is smaller than the half-maximum width λ1 of the spectrum of light emitted by the light-emitting layer 130 of the first light-emitting device 101.

[0143] The structures of the guest material GD, the first host material GHP, and the second host material GHN of the first light-emitting device 101 are exemplarily introduced below.

[0144] In some embodiments, the guest material GD of the light-emitting layer 130 of the first light-emitting device 101 is selected from any one of the structures represented by the following general formula (I).

[0145] Wherein, X1 is selected from any one of oxygen and sulfur.

[0146] R1, R2, R3, R4 and R5 are the same or different and are independently selected from any one of hydrogen, deuterium, substituted or unsubstituted methyl, substituted or unsubstituted ethyl, substituted or unsubstituted propyl, substituted or unsubstituted isopropyl, substituted or unsubstituted n-butyl, substituted or unsubstituted isobutyl, substituted or unsubstituted sec-butyl, substituted or unsubstituted tert-butyl, substituted or unsubstituted cyclopropyl, substituted or unsubstituted cyclobutyl, substituted or unsubstituted cyclopentyl, substituted or unsubstituted cyclohexyl and substituted or unsubstituted phenyl.

[0147] n1 and n5 are the same or different and are independently selected from any one of 0, 1, 2, 3 and 4.

[0148] n2 is selected from any one of 0, 1, 2, 3, 4 and 5.

[0149] n3 and n4 are the same or different and are independently selected from any one of 0, 1, 2 and 3.

[0150] It should be noted that in the structure shown in general formula (I), (Ry) nx , means that the number of Ry is nx. When nx is 0, it means that the substitution positions of the carbon atoms with substitution positions on the corresponding six-membered ring are all replaced by hydrogen atoms. When nx is z, and z is a positive integer greater than or equal to 1, it means that z Ry are connected to the corresponding six-membered ring; and, the z Ry can be connected to any z carbon atoms with substitution positions among the six carbon atoms on the six-membered ring; and, the z Ry can be the same or different. Here, there is no limitation on the position of the carbon atom connected to Ry. Wherein, x is any one of 1, 2, 3, 4 and 5, y is any one of 1, 2, 3, 4 and 5, and z is any one of the values ​​greater than or equal to 1 in the selection range of nx.

[0151] It should be noted that when R1, R2, R3, R4 or R5 is selected from any one of a substituted methyl group, a substituted ethyl group, a substituted propyl group, a substituted isopropyl group, a substituted n-butyl group, a substituted isobutyl group, a substituted sec-butyl group, a substituted tert-butyl group, a substituted cyclopropyl group, a substituted cyclobutyl group, a substituted cyclopentyl group, a substituted cyclohexyl group and a substituted phenyl group, the type of the substituent is not limited here.

[0152] It can be understood that the structure shown in the above general formula (I) is a structure with platinum as the central atom and includes a tetradentate ligand, and the tetradentate ligand is connected to the central atom via a coordination bond.

[0153] Based on the structure shown in general formula (I), the guest material GD can emit light of a first wavelength, which is green light. Moreover, compared to some implementations in which the guest material is a phosphorescent material containing a bidentate ligand (e.g., guest material R-GD), the tetradentate ligand design is relatively more reasonable, providing a suitable coordination position for the central platinum atom of the phosphorescent material, thereby making the molecular rigidity of the guest material GD relatively high. Moreover, the tetradentate ligand can maintain a square planar configuration, thereby improving the orientation of the guest material GD. In this way, the luminous efficiency, service life, and color purity of the first light-emitting device 101 can be improved.

[0154] An exemplary structure of the guest material GD of the light-emitting layer 130 of the first light-emitting device 101 having a structure as represented by general formula (I) is described below.

[0155] In some examples, when X1 is oxygen, the structural formula of the guest material GD of the light-emitting layer 130 of the first light-emitting device 101 may be as shown below.

[0156] In some examples, when X1 is sulfur, the structural formula of the guest material GD of the light-emitting layer 130 of the first light-emitting device 101 can be as shown below.

[0157] It should be noted that the above-listed structural formulas are examples of the structures of the guest material GD in the light-emitting layer 130 of the first light-emitting device 101, and do not limit the guest material GD in the light-emitting layer 130 of the first light-emitting device 101. Moreover, (GD-x) in the above-listed structural formulas is a synonym for each structural formula and does not constitute a part of the structural formula structure, where x is a positive integer.

[0158] In some embodiments, in the first light-emitting device 101 , a mass ratio of the guest material GD to the host material is greater than or equal to 5% and less than or equal to 14%.

[0159] It should be noted that the mass ratio between the guest material GD and the host material is greater than or equal to 5% and less than or equal to 14%, which means that the mass m of the guest material GD is greater than or equal to 5%. GD , the mass m of the first host material GHP GHP , and the mass m of the second host material GHN GHN , satisfied with there.

[0160] It can be understood that when the mass ratio between the guest material GD and the host material is greater than or equal to 5% and less than or equal to 14%, the mass ratio between the guest material GD and the host material is reasonable, which can make the energy transmission in the first light-emitting device 101 relatively high under the synergistic effect of the guest material GD and the host material, thereby improving the efficiency of the first light-emitting device 101.

[0161] For example, in the first light-emitting device 101 , the mass ratio of the guest material GD to the host material is 10%; or, the mass ratio of the guest material GD to the host material is 5%, 7%, 9%, 12% or 14%.

[0162] In some embodiments, the first host material GHP of the light-emitting layer 130 of the first light-emitting device 101 is selected from any one of the structures represented by the following general formula (III).

[0163] Wherein, L1 and L2 are the same or different and are independently selected from any one of substituted or unsubstituted phenylene, substituted or unsubstituted biphenylene and substituted or unsubstituted naphthylene.

[0164] R 11 、R 12 、R 13 、R 14 、R 15 and R 16 are the same or different and are independently selected from any one of hydrogen, deuterium, substituted or unsubstituted methyl, substituted or unsubstituted ethyl, substituted or unsubstituted propyl, substituted or unsubstituted isopropyl, substituted or unsubstituted n-butyl, substituted or unsubstituted isobutyl, substituted or unsubstituted sec-butyl, substituted or unsubstituted tert-butyl, substituted or unsubstituted cyclopropyl, substituted or unsubstituted cyclobutyl, substituted or unsubstituted cyclopentyl, substituted or unsubstituted cyclohexyl and substituted or unsubstituted phenyl.

[0165] n 11 and n 12 are the same or different, and are independently selected from any one of 0 and 1.

[0166] n 13 and n 16 The same or different, each independently selected from any one of 0, 1, 2, 3 and 4.

[0167] n 14 and n 15 are the same or different and are independently selected from any one of 0, 1 and 2.

[0168] It should be noted that here R 13 、R 14 、R15 and R 16 The description of R1 can be found above; here, n 13 、n 14 、n 15 and n 16 The description of n1 can be found in the above description, which will not be repeated here.

[0169] It should be noted that, in the general formula (III), In the above general formula (III), the number of L1 is n 11 , the number of L2 n 12 Can be 0. When n 11 When it is 0, the nitrogen in the carbazole group and R 11 Directly connected by a covalent bond (eg, a single bond). 12 When it is 0, the nitrogen in the carbazole group and R 11 Directly connected by a covalent bond (e.g., a single bond). In the general formula (III), L1 and L2 can be substituted or unsubstituted biphenylene or substituted or unsubstituted naphthylene. The structure of phenylene is introduced below. Phenyl refers to the general term for the group remaining after the hydrogen atom of one carbon atom on the benzene ring is removed. Phenylene refers to the general term for the group remaining after the hydrogen atoms on two carbon atoms on the benzene ring are removed. For the understanding of naphthylene, please refer to the above content and will not be repeated here. When L1 or L2 is a substituted biphenylene or a substituted naphthylene, there is no limitation on the type and number of substituents.

[0170] It should be noted that when R 11 、R 12 、R 13 、R 14 、R 15 and R 16 When the substituent is selected from any one of a substituted methyl group, a substituted ethyl group, a substituted propyl group, a substituted isopropyl group, a substituted n-butyl group, a substituted isobutyl group, a substituted sec-butyl group, a substituted tert-butyl group, a substituted cyclopropyl group, a substituted cyclobutyl group, a substituted cyclopentyl group, a substituted cyclohexyl group and a substituted phenyl group, the type of the substituent is not limited here.

[0171] It can be understood that the structure shown in the general formula (III) contains two carbazole groups connected by a single bond, which can make the hole cloud have a higher distribution density on the structure of the two carbazole groups connected by a single bond. In this way, the first host material GHP of the light-emitting layer 130 of the first light-emitting device 101 has a higher hole transport performance and plays the function of a hole-type host. In this way, during the light-emitting process of the first light-emitting device 101, the first host material GHP and the second host material GHN can form an exciton complex GHP / GHN, transfer the exciton energy to the guest material DGD, achieve the purpose of emitting light, and improve the efficiency of the first light-emitting device 101. Moreover, since the first light-emitting device 101 emits green light with a relatively small wavelength and a relatively high energy compared to other light-emitting devices 100 (for example, the second light-emitting device 102), when the first host material HP contains two carbazole groups connected by a single bond, the triplet energy level T1 (GHP) of the first host material HP is relatively high, and the matching with the second host material GHN and the guest material GD of the light-emitting layer 130 of the first light-emitting device 101 is relatively better, so that the excitons on the guest material GD are not easily returned to the host material, thereby reducing the quenching of the excitons. In this way, the efficiency of the first light-emitting device 101 can be improved.

[0172] The following describes an exemplary structure of the first host material GHP of the light-emitting layer 130 of the first light-emitting device 101 having a structure represented by general formula (III).

[0173] In some examples, when L1 and L2 are both phenylene, R 11 and R 12 When all of them are phenyl groups, the structural formula of the first host material GHP of the light-emitting layer 130 of the first light-emitting device 101 can be shown as follows.

[0174] It should be noted that the above-listed structural formulas are examples of the structures of the first host material GHP of the light-emitting layer 130 of the first light-emitting device 101, and do not limit the first host material GHP of the light-emitting layer 130 of the first light-emitting device 101. Moreover, (GHP-x) in the above-listed structural formulas is a synonym for each structural formula and does not constitute a part of the structural formula structure, where x is a positive integer.

[0175] In some embodiments, the second host material GHN of the light-emitting layer 130 of the first light-emitting device 101 is selected from any one of the structures represented by the following general formula (IV).

[0176] Wherein, L3 and L4 are the same or different and are independently selected from any one of substituted or unsubstituted phenylene, substituted or unsubstituted biphenylene and substituted or unsubstituted naphthylene.

[0177] R 17 、R 18 、R 19 、R 20 、R 21 and R 22 the same or different, and independently selected from any one of substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted dimethylfluorenyl, substituted or unsubstituted diphenylfluorenyl, substituted or unsubstituted benzothiophenyl, substituted or unsubstituted benzoxazolyl and substituted or unsubstituted benzimidazolyl.

[0178] n 17 and n 18 are the same or different, and are independently selected from any one of 0 and 1.

[0179] n 20 and n 22 The same or different, each independently selected from any one of 0, 1, 2, 3 and 4.

[0180] n 21 Select any one from 0, 1 and 2.

[0181] It should be noted that here R 20 、R 21 and R 22 The description of L3 and L4 can refer to the description of L1 and L2 above; 20 、n 21 and n 22 The description of n1 can be found in the above description; 17 and n 18 The description of n can be found in the above 11 and n 12 description; no further description is given here.

[0182] It should be noted that when L3 or L4 is selected from any one of substituted phenylene, substituted biphenylene and substituted naphthylene, and / or R 17 、R 18 、R 19 、R 20 、R 21 or R 22When the substituent is selected from any one of a substituted phenyl group, a substituted biphenyl group, a substituted terphenyl group, a substituted naphthyl group, a substituted dibenzofuranyl group, a substituted dibenzothiophenyl group, a substituted dimethylfluorenyl group, a substituted diphenylfluorenyl group, a substituted benzothiophenyl group, a substituted benzoxazolyl group and a substituted benzimidazolyl group, the type of the substituent is not limited here.

[0183] It is understood that the structure shown in the above general formula (IV) contains a triazine group, that is, The electron cloud can be made to have a higher distribution density on the above-mentioned triazine-based structure, so that the second main material GHN of the light-emitting layer 130 of the first light-emitting device 101 has higher electron transport performance and plays the function of an electronic host. In this way, during the light-emitting process of the first light-emitting device 101, the first main material GHP and the second main material GHN can form an exciton complex GHP / GHN, transfer the exciton energy to the guest material DGD, achieve the purpose of emitting light, and improve the efficiency of the first light-emitting device 101.

[0184] Moreover, the structure shown in the above general formula (IV) contains an indole-carbazolyl group, that is, Furthermore, the substituents attached to both nitrogen atoms in the indolecarbazolyl group produce a certain steric effect, which can reduce the molecular torsion of the second host material HN and increase the triplet energy level T1(GHN) of the second host material HN. Since the first light-emitting device 101 emits green light, the corresponding wavelength is relatively short and the corresponding energy is relatively high compared to other light-emitting devices 100 (e.g., the second light-emitting device 102). When the second host material HN includes an indolecarbazolyl group, the triplet energy level T1(GHN) of the second host material HN is relatively high, resulting in a relatively better match with the first host material GHP and the guest material GD of the light-emitting layer 130 of the first light-emitting device 101. This makes it difficult for excitons in the guest material GD to flow back to the host material, reducing exciton quenching. Thus, the efficiency of the first light-emitting device 101 can be improved.

[0185] In some examples, when the second main material GHN of the light-emitting layer 130 of the first light-emitting device 101 is selected from any one of the structures shown in general formula (IV), the energy transfer process diagram of the material of the light-emitting layer 130 of the first light-emitting device 101 during electroluminescence is as shown in Figure 11.

[0186] As shown in Figure 11, when the second host material GHN of the light-emitting layer 130 of the first light-emitting device 101 is selected from any of the structures represented by general formula (IV), the difference between the singlet energy level S1 and the triplet energy level T1 of the second host material GHN is relatively small. Moreover, not only intersystem crossing (ISC) but also reverse intersystem crossing (RISC) occurs between the singlet energy level S1 and the triplet energy level T1 of the second host material GHN, which can achieve localized excited states and endow the second host material GHN with a certain thermally activated delayed fluorescence (TADF) effect. Thus, when the material of the light-emitting layer 130 of the first light-emitting device 101 generates electroluminescence, excitons generated by the first host material GHP and the second host material GHN can be transferred to the guest material GD through the second host material GHN, achieving efficient energy transfer. Therefore, by configuring the second host material GHN of the light-emitting layer 130 of the first light-emitting device 101 to be any one of the structures shown in general formula (IV), efficient energy transfer of the first light-emitting device 101 can be achieved, thereby improving the efficiency of the first light-emitting device 101.

[0187] The following describes an exemplary structure of the second host material GHN of the light-emitting layer 130 of the first light-emitting device 101 having a structure represented by general formula (IV).

[0188] In some examples, when n 17 and n 18 When both are 0, the structural formula of the second host material GHN of the light-emitting layer 130 of the first light-emitting device 101 can be shown as follows.

[0189] In some examples, when n 17 is 0, n 18 When L is 1 and L4 is a phenylene group, the structural formula of the second host material GHN of the light-emitting layer 130 of the first light-emitting device 101 can be shown as follows.

[0190] In some examples, when n 18 is 0, n 17 When L is 1 and L3 is a phenylene group, the structural formula of the second host material GHN of the light-emitting layer 130 of the first light-emitting device 101 can be shown as follows.

[0191] It should be noted that the above-listed structural formulas are examples of the structures of the second host material GHN of the light-emitting layer 130 of the first light-emitting device 101, and do not limit the second host material GHN of the light-emitting layer 130 of the first light-emitting device 101. Moreover, (GHN-x) in the above-listed structural formulas is a denomination of each structural formula and is not part of the structural formula structure, where x is a positive integer.

[0192] In some embodiments, in the first light-emitting device 101 , a mass ratio between the first host material GHP and the second host material GHN is greater than or equal to 1:1 and less than or equal to 7:3.

[0193] It should be noted that the mass ratio between the first host material GHP and the second host material GHN is greater than or equal to 1:1 and less than or equal to 7:3, which means that the mass m of the first host material GHP is greater than or equal to 1:1 and less than or equal to 7:3. GHP , and the mass m of the second host material GHN GHN , satisfied with there.

[0194] It can be understood that when the mass ratio between the first host material GHP and the second host material GHN is greater than or equal to 1:1 and less than or equal to 7:3, the mass ratio between the first host material GHP and the second host material GHN is reasonable, which can make the electron transmission rate and the hole transmission rate in the first light-emitting device 101 relatively balanced, and can increase the exciton yield. In this way, the energy utilization rate can be relatively high, and the efficiency of the first light-emitting device 101 can be improved.

[0195] For example, in the first light-emitting device 101 , the mass ratio of the first host material GHP to the second host material GHN is 6:4; or, the mass ratio of the first host material GHP to the second host material GHN is 1:1, 5:4, 4:3 or 7:3.

[0196] The above exemplary introduction describes the structures of the guest material GD, the first host material GHP, and the second host material GHN of the first light-emitting device 101. The following exemplary introduction describes the structures of the guest material RD, the first host material RHP, and the second host material RHN of the second light-emitting device 102.

[0197] In some embodiments, the guest material RD of the light-emitting layer 130 of the second light-emitting device 102 is selected from any one of the structures represented by the following general formula (II).

[0198] Wherein, X2 is selected from any one of oxygen and sulfur.

[0199] Ar1 is selected from any one of a substituted or unsubstituted benzene ring and a substituted or unsubstituted naphthalene ring.

[0200] R6, R7, R8, R9 and R 10are the same or different and are independently selected from any one of hydrogen, deuterium, substituted or unsubstituted methyl, substituted or unsubstituted ethyl, substituted or unsubstituted propyl, substituted or unsubstituted isopropyl, substituted or unsubstituted n-butyl, substituted or unsubstituted isobutyl, substituted or unsubstituted sec-butyl, substituted or unsubstituted tert-butyl, substituted or unsubstituted cyclopropyl, substituted or unsubstituted cyclobutyl, substituted or unsubstituted cyclopentyl, substituted or unsubstituted cyclohexyl and substituted or unsubstituted phenyl.

[0201] n6 is selected from any one of 0, 1, 2, 3 and 4.

[0202] n7 is selected from any one of 0, 1, 2, 3, 4 and 5.

[0203] n8 and n9 are the same or different and are independently selected from any one of 0, 1, 2 and 3.

[0204] n 10 Select any one from 0, 1 and 2.

[0205] It should be noted that here R6, R7, R8, R9 and R 10 The description of n6, n7, n8, n9 and n 10 The description of n1 can be found in the above description, which will not be repeated here.

[0206] It should be noted that when R6, R7, R8, R9 or R 10 When the substituent is selected from any one of a substituted methyl group, a substituted ethyl group, a substituted propyl group, a substituted isopropyl group, a substituted n-butyl group, a substituted isobutyl group, a substituted sec-butyl group, a substituted tert-butyl group, a substituted cyclopropyl group, a substituted cyclobutyl group, a substituted cyclopentyl group, a substituted cyclohexyl group and a substituted phenyl group, the type of the substituent is not limited here.

[0207] It should be noted that when Ar1 is selected from a substituted or unsubstituted benzene ring, the position of the shared carbon atoms between Ar1 and the six-membered heterocyclic ring E is not limited here. For example, the shared carbon atoms between Ar1 and the six-membered heterocyclic ring E can be carbon atoms 1 and 2, or carbon atoms 2 and 3, or carbon atoms 3 and 4. When Ar1 is selected from a substituted or unsubstituted naphthalene ring, the number and position of the shared carbon atoms between Ar1 and the six-membered heterocyclic ring E are not limited here. For example, the number of shared carbon atoms between Ar1 and the six-membered heterocyclic ring E can be two or three. Among them, when the number of shared carbon atoms between Ar1 and the six-membered heterocyclic ring E is two, the shared carbon atoms between Ar1 and the six-membered heterocyclic ring E can be carbon atoms 1 and 2, or carbon atoms 2 and 3, or carbon atoms 3 and 4. When the number of carbon atoms shared by Ar1 and the six-membered heterocyclic ring E is three, the carbon atoms shared by Ar1 and the six-membered heterocyclic ring E may be carbon atoms 1, 2, or 3, or carbon atoms 2, 3, or 4.

[0208] It can be understood that the structure represented by the general formula (II) is a structure with platinum as the central atom and includes a tetradentate ligand, and the tetradentate ligand is connected to the central atom via a coordination bond. Moreover, compared to the guest material GD of the light-emitting layer 130 of the first light-emitting device 101 having the structure represented by the general formula (I), the guest material RD of the light-emitting layer 130 of the second light-emitting device 102 having the structure represented by the general formula (II) has a six-membered heterocyclic ring E and Ar1 (a benzene ring or a naphthalene ring) fused together. In this way, the wavelength of light emitted by the guest material RD of the light-emitting layer 130 of the second light-emitting device 102 can be red-shifted by a certain wavelength compared to the wavelength of light emitted by the guest material GD of the light-emitting layer 130 of the first light-emitting device 101. In this way, the guest material RD of the light-emitting layer 130 of the second light-emitting device 102 can emit light of a second wavelength, and the second wavelength is red light.

[0209] Moreover, based on the structure shown in general formula (II), compared with the case in which the guest material is a phosphorescent material containing a bidentate ligand (for example, the guest material R-RD) in some implementations, the tetradentate ligand design is relatively more reasonable, and can provide a suitable coordination position for the central atom platinum of the phosphorescent material, so that the molecular rigidity of the guest material RD is relatively high. The tetradentate ligand can maintain a square planar configuration, so that the orientation of the guest material RD is improved, thereby improving the luminous efficiency, service life, and color purity of the second light-emitting device 102.

[0210] The following describes an exemplary structure of the guest material RD of the light-emitting layer 130 of the second light-emitting device 102 having a structure represented by general formula (II).

[0211] In some examples, when X2 is oxygen, the structural formula of the guest material RD of the light-emitting layer 130 of the second light-emitting device 102 can be as shown below.

[0212] It should be noted that the above-listed structural formulas are examples of the structures of the guest material RD of the light-emitting layer 130 of the second light-emitting device 102, and do not limit the guest material RD of the light-emitting layer 130 of the second light-emitting device 102. Moreover, (RD-x) in the above-listed structural formulas is a synonym for each structural formula and is not a part of the structural formula structure, where x is a positive integer.

[0213] In some embodiments, the guest material RD of the light-emitting layer 130 of the second light-emitting device 102 is selected from any one of the structures represented by the following general formula (II-A).

[0214] Wherein, X3 is selected from any one of oxygen and sulfur.

[0215] It should be noted that here R6, R7, R8, R9 and R 10 The description of R6, R7, R8, R9 and R 10 Here, the description of X2 can refer to the above description of X2; Here, n6, n7, n8, n9 and n 10 For the description of n6, n7, n8, n9 and n 10 The description of Ar1 here can refer to the above description of Ar1, which will not be repeated here.

[0216] It is understood that when X3 is connected between the six-membered carbon ring containing R8 and the six-membered carbon ring containing R9 in the structure shown in general formula (II), the structure shown in general formula (II) can be transformed into the structure shown in general formula (II-A). Because when X3 is connected between the six-membered carbon ring containing R8 and the six-membered carbon ring containing R9, the number of fused rings on the tetradentate ligand increases. Therefore, when the guest material RD of the light-emitting layer 130 of the second light-emitting device 102 is selected from any of the structures shown in general formula (II-A), compared to the case where the guest material RD of the light-emitting layer 130 of the second light-emitting device 102 is selected from any of the structures shown in general formula (II), the molecular rigidity of the guest material can be relatively high, resulting in a relatively high molecular orientation of the guest material. In this way, the luminous efficiency, service life, and color purity of the second light-emitting device 102 can be improved.

[0217] The following describes an exemplary structure of the guest material RD of the light-emitting layer 130 of the second light-emitting device 102 having a structure represented by the general formula (II-A).

[0218] In some examples, when X2 is oxygen and X3 is oxygen, the structural formula of the guest material RD of the light-emitting layer 130 of the second light-emitting device 102 can be as shown below.

[0219] In some examples, when X2 is sulfur and X3 is sulfur, the structural formula of the guest material RD of the light-emitting layer 130 of the second light-emitting device 102 can be as shown below.

[0220] It should be noted that the above-listed structural formulas are examples of the structures of the guest material RD of the light-emitting layer 130 of the second light-emitting device 102, and do not limit the guest material RD of the light-emitting layer 130 of the second light-emitting device 102. Moreover, (RD-x) in the above-listed structural formulas is a synonym for each structural formula and is not a part of the structural formula structure, where x is a positive integer.

[0221] In some embodiments, in the second light-emitting device 102 , a mass ratio of the guest material RD to the host material is greater than or equal to 1% and less than or equal to 5%.

[0222] It should be noted that the mass ratio between the guest material RD and the host material is greater than or equal to 1% and less than or equal to 5%, which means the mass m of the guest material RD is greater than or equal to 1%. RD , the mass m of the first host material RHP RHP , and the mass m of the second host material RHN RHN , satisfied with there.

[0223] It can be understood that when the mass ratio between the guest material D and the host material is greater than or equal to 1% and less than or equal to 5%, the mass ratio between the guest material RD and the host material is reasonable, which can make the energy transmission in the second light-emitting device 102 relatively high under the synergistic effect of the guest material RD and the host material, thereby improving the efficiency of the second light-emitting device 102.

[0224] For example, in the second light-emitting device 102 , the mass ratio of the guest material RD to the host material is 1%, 2%, 3%, 3.5%, 4% or 5%.

[0225] In some embodiments, the first host material RHP of the light-emitting layer 130 of the second light-emitting device 102 is selected from any one of the structures represented by the following general formula (V).

[0226] Among them, R 23 、R 24 、R 25 、R 26 、R 27 and R28 are the same or different and are independently selected from any one of hydrogen, deuterium, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C1-C6 cycloalkyl, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophenyl and substituted or unsubstituted carbazolyl.

[0227] n 23 and n 24 The same or different, each independently selected from any one of 0, 1, 2, 3, 4 and 5.

[0228] n 25 and n 28 The same or different, each independently selected from any one of 0, 1, 2, 3 and 4.

[0229] n 26 and n 27 are the same or different and are independently selected from any one of 0, 1 and 2.

[0230] It should be noted that here R 23 、R 24 、R 25 、R 26 、R 27 and R 28 The description of R1 can be found above; here, n 23 、n 24 、n 25 、n 26 、n 275 and n 28 The description of n1 can be found in the above description, which will not be repeated here.

[0231] It should be noted that when R 23 、R 24 、R 25 、R 26 、R 27 or R 28 When the substituent is selected from any of substituted C1-C6 alkyl, substituted C1-C6 cycloalkyl, substituted phenyl, substituted naphthyl, substituted dibenzofuranyl, substituted dibenzothiophenyl, and substituted carbazolyl, the type of substituent is not limited. A Cx alkyl group refers to an alkyl group having x carbon (C) atoms, where x is a positive integer. The same applies hereinafter. For other examples, such as Cx cycloalkyl groups, please refer to the above description and will not be elaborated upon here.

[0232] It is understood that the structure shown in the above general formula (V) contains a benzindolecarbazolyl group, that is, The hole cloud can be made to have a higher distribution density on the above-mentioned benzindole-carbazole structure, so that the first host material RHP of the light-emitting layer 130 of the second light-emitting device 102 has a higher hole transport performance and plays the function of a hole-type host. In this way, during the light-emitting process of the second light-emitting device 102, the first host material RHP and the second host material RHN can form an exciton complex RHP / RHN, transfer the exciton energy to the guest material RD, achieve the purpose of emitting light, and improve the efficiency of the second light-emitting device 102. Moreover, since the second light-emitting device 102 emits red light with a relatively large wavelength and a relatively low energy compared to other light-emitting devices 100 (for example, the first light-emitting device 101), when the first host material RHP contains a planar group - a benzoindolecarbazole group, the molecular rigidity of the first host material RHP is relatively high, and the molecular orientation is relatively high, so that the triplet energy level T1 (RHP) of the first host material RHP is relatively low, and the matching with the second host material RHN and the guest material RD of the light-emitting layer 130 of the second light-emitting device 102 is relatively better. In this way, the efficiency of the second light-emitting device 102 can be improved.

[0233] The following describes an exemplary structure of the first host material RHP of the light-emitting layer 130 of the second light-emitting device 102 having a structure as shown in general formula (V).

[0234] In some examples, when R 23 When it is a dibenzofuranyl group, the structural formula of the first host material RHP of the light-emitting layer 130 of the second light-emitting device 102 can be shown as follows.

[0235] In some examples, when R 23 When it is a naphthyl group, the structural formula of the first host material RHP of the light-emitting layer 130 of the second light-emitting device 102 can be shown as follows.

[0236] In some examples, when R 23 When the carbazole group is substituted with a phenyl group, the structural formula of the first host material RHP of the light-emitting layer 130 of the second light-emitting device 102 can be shown as follows.

[0237] It should be noted that the above-listed structural formulas are examples of the structures of the first host material RHP of the light-emitting layer 130 of the second light-emitting device 102, and do not limit the first host material RHP of the light-emitting layer 130 of the second light-emitting device 102. Moreover, (RHP-x) in the above-listed structural formulas is a synonym for each structural formula and is not part of the structural formula structure, where x is a positive integer.

[0238] In some embodiments, the second host material RHN of the light-emitting layer 130 of the second light-emitting device 102 is selected from any one of the structures represented by the following general formula (VI).

[0239] Wherein, L5, L6 and L7 are the same or different and are independently selected from any one of substituted or unsubstituted phenylene, substituted or unsubstituted biphenylene, substituted or unsubstituted naphthylene, substituted or unsubstituted dibenzofuranylene, substituted or unsubstituted benzodibenzofuranylene, substituted or unsubstituted dibenzothiophenylene, substituted or unsubstituted benzodibenzothiophenylene, substituted, substituted or unsubstituted carbazolylene, substituted, substituted or unsubstituted benzocarbazolylene and substituted, substituted or unsubstituted phenanthroxazolyl.

[0240] R 29 、R 30 and R 31 The same or different, each independently selected from any one of substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted benzodibenzofuranyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted benzodibenzothiophenyl, substituted, substituted or unsubstituted carbazolyl, substituted, substituted or unsubstituted benzocarbazolyl and substituted, substituted or unsubstituted phenanthroxazolyl.

[0241] n 29 、n 30 and n 31 are the same or different, and are independently selected from any one of 0 and 1.

[0242] It should be noted that here n 29 、n 30 and n 31 The description of n can be found in the above 11 and n 12 description; no further description is given here.

[0243] It should be noted that when L5, L6 or L7 is selected from any one of substituted phenylene, substituted biphenylene, substituted naphthylene, substituted dibenzofuranyl, substituted benzodibenzofuranyl, substituted dibenzothiophenylene, substituted benzodibenzothiophenylene, substituted carbazolyl, substituted benzocarbazolyl and substituted phenanthroxazolyl, and / or R 29 、R 30 and R 31When the substituent is selected from any one of a substituted phenyl group, a substituted biphenyl group, a substituted naphthyl group, a substituted dibenzofuranyl group, a substituted benzodibenzofuranyl group, a substituted dibenzothiophenyl group, a substituted benzodibenzothiophenyl group, a substituted carbazolyl group, a substituted benzocarbazolyl group and a substituted phenanthroxazolyl group, the type of the substituent is not limited here.

[0244] It is understood that the structure shown in the above general formula (VI) contains a triazine group, that is, The electron cloud can be made to have a higher distribution density on the above-mentioned triazine-based structure, so that the second main material RHN of the light-emitting layer 130 of the second light-emitting device 102 has higher electron transport performance and plays the function of an electronic main body. In this way, during the light-emitting process of the second light-emitting device 102, the first main material RHP and the second main material RHN can form an exciton complex RHP / RHN, transfer the exciton energy to the guest material RGD, achieve the purpose of emitting light, and improve the efficiency of the second light-emitting device 102.

[0245] Furthermore, in the structure represented by the above general formula (VI), R 29 、R 30 and R 31 The range of substituents selected includes phenyl, biphenyl, naphthyl, dibenzofuranyl, benzodibenzofuranyl, dibenzothiophenyl, benzodibenzothiophenyl, carbazolyl, benzocarbazolyl, and phenanthroxazolyl. These substituents are all planar groups. These planar groups can make the triplet energy level T1(RHN) of the second host material RHN relatively low, thereby reducing the triplet energy level T1(RHN) of the second host material RHN. Since the second light-emitting device 102 emits red light with a relatively shorter wavelength and higher energy than other light-emitting devices 100 (e.g., the first light-emitting device 101), when the second host material RHN includes the above-mentioned planar groups, the triplet energy level T1(RHN) of the second host material RHN is relatively low, and the compatibility with the first host material RHP and the guest material RD of the light-emitting layer 130 of the second light-emitting device 102 is relatively better, thereby improving the efficiency of the second light-emitting device 102.

[0246] The following describes an exemplary structure of the second host material RHN of the light-emitting layer 130 of the second light-emitting device 102 having a structure represented by formula (VI).

[0247] In some examples, when R 29 When it is a deuterated naphthyl group, the structural formula of the second host material RHN of the light-emitting layer 130 of the second light-emitting device 102 can be shown as follows.

[0248] In some examples, when R 29When it is a phenyl group, the structural formula of the second host material RHN of the light-emitting layer 130 of the second light-emitting device 102 can be shown as follows.

[0249] It should be noted that the above-listed structural formulas are examples of the structure of the second host material RHN of the light-emitting layer 130 of the second light-emitting device 102, and do not limit the second host material RHN of the light-emitting layer 130 of the second light-emitting device 102. Moreover, (RHN-x) in the above-listed structural formulas is a synonym for each structural formula and is not part of the structural formula structure, where x is a positive integer.

[0250] In some embodiments, in the second light-emitting device 102 , a mass ratio between the first host material RHP and the second host material RHN is greater than or equal to 3:7 and less than or equal to 1:1.

[0251] It should be noted that the mass ratio between the first host material RHP and the second host material RHN and the mass ratio between the guest material RD and the host material is greater than or equal to 3:7 and less than or equal to 1:1, which means that the mass ratio m of the first host material RHP is greater than or equal to 3:7 and less than or equal to 1:1. RHP , and the mass m of the second host material RHN RHN , satisfied with there.

[0252] It can be understood that when the mass ratio between the first host material RHP and the second host material RHN is greater than or equal to 3:7 and less than or equal to 1:1, the mass ratio between the first host material RHP and the second host material RHN is reasonable, which can make the electron transmission rate and the hole transmission rate in the first light-emitting device 101 relatively balanced, and can increase the exciton yield. In this way, the energy utilization rate can be relatively high, and the efficiency of the second light-emitting device 102 can be improved.

[0253] For example, in the second light-emitting device 102 , the mass ratio between the first host material RHP and the second host material RHN is 3:7, 4:6, 3:4, 4:5 or 1:1.

[0254] In some embodiments, when the guest material GD of the light-emitting layer 130 of the first light-emitting device 101 is selected from any one of the structures represented by general formula (I), at least one of R1, R2, R3, R4 and R5 contains deuterium.

[0255] Since the atomic weight of deuterium is twice that of hydrogen, by setting at least one of R1, R2, R3, R4 and R5 in the structure shown in general formula (I) to contain deuterium, the physical properties of the guest material GD of the light-emitting layer 130 of the first light-emitting device 101 will change. Specifically, after the guest material GD of the light-emitting layer 130 of the first light-emitting device 101 is replaced by deuterium, the molecular vibration can be effectively suppressed, the bond length can be reduced, the bond energy can be increased, and the molecular stability can be improved. In this way, the thermal stability of the guest material GD of the light-emitting layer 130 of the first light-emitting device 101 is improved, and the life of the first light-emitting device 101 can be increased.

[0256] In some examples, when R1 and R5 contain deuterium, the structural formula of the guest material GD of the light-emitting layer 130 of the first light-emitting device 101 can be as shown in Formula (GD-2).

[0257] In some embodiments, when the first host material GHP of the light-emitting layer 130 of the first light-emitting device 101 is selected from any one of the structures shown in general formula (III), L1, L2, R 11 、R 12 、R 13 、R 14 、R 15 and R 16 At least one of them contains deuterium.

[0258] Since the atomic weight of deuterium is twice that of hydrogen, L1, L2, R 11 、R 12 、R 13 、R 14 、R 15 and R 16 In the case where at least one of the materials contains deuterium, the physical properties of the first main material GHP of the light-emitting layer 130 of the first light-emitting device 101 will change. Specifically, after the first main material GHP of the light-emitting layer 130 of the first light-emitting device 101 is replaced by deuterium, molecular vibration can be effectively suppressed, bond length can be reduced, bond energy can be increased, and molecular stability can be improved. In this way, the thermal stability of the first main material GHP of the light-emitting layer 130 of the first light-emitting device 101 is improved, and the life of the first light-emitting device 101 can be increased.

[0259] In some examples, when R 13 、R 14 、R 15 and R 16 When deuterium is contained, the structural formula of the first host material GHP of the light-emitting layer 130 of the first light-emitting device 101 may be as shown in Formula (GHP-1).

[0260] In other examples, when R 12When deuterium is contained, the structural formula of the first host material GHP of the light-emitting layer 130 of the first light-emitting device 101 may be as shown in Formula (GHP-3).

[0261] In some embodiments, when the second host material GHN of the light-emitting layer 130 of the first light-emitting device 101 is selected from any one of the structures shown in general formula (IV), L3, L4, R 17 、R 18 、R 19 、R 20 、R 21 and R 22 At least one of them contains deuterium.

[0262] Since the atomic weight of deuterium is twice that of hydrogen, L3, L4, R 17 、R 18 、R 19 、R 20 、R 21 and R 22 In the case where at least one of the materials contains deuterium, the physical properties of the second main material GHN of the light-emitting layer 130 of the first light-emitting device 101 will change. Specifically, after the second main material GHN of the light-emitting layer 130 of the first light-emitting device 101 is replaced by deuterium, molecular vibration can be effectively suppressed, bond length can be reduced, bond energy can be increased, and molecular stability can be improved. In this way, the thermal stability of the second main material GHN of the light-emitting layer 130 of the first light-emitting device 101 is improved, and the life of the first light-emitting device 101 can be increased.

[0263] In some examples, when R 20 、R 21 and R 22 When deuterium is contained, the structural formula of the second host material GHN of the light-emitting layer 130 of the first light-emitting device 101 may be as shown in Formula (GHN-1).

[0264] In other examples, when R 19 When deuterium is contained, the structural formula of the second host material GHN of the light-emitting layer 130 of the first light-emitting device 101 may be as shown in Formula (GHN-3).

[0265] In some embodiments, when the guest material RD of the light-emitting layer 130 of the second light-emitting device 102 is selected from any one of the structures represented by formula (II) or formula (II-A), Ar1, R6, R7, R8, R9 and R 10 At least one of them contains deuterium.

[0266] Since the atomic weight of deuterium is twice that of hydrogen, Ar1, R6, R7, R8, R9 and R10 In the case where at least one of the light emitting devices 102 contains deuterium, the physical properties of the guest material RD of the light emitting layer 130 of the second light emitting device 102 will change. Specifically, after the guest material RD of the light emitting layer 130 of the second light emitting device 102 is replaced by deuterium, molecular vibration can be effectively suppressed, bond length can be reduced, bond energy can be increased, and molecular stability can be improved. In this way, the thermal stability of the guest material RD of the light emitting layer 130 of the second light emitting device 102 is improved, and the life of the second light emitting device 102 can be increased.

[0267] In some examples, when R1, R2, R4, and R5 contain deuterium, the structural formula of the guest material RD of the light-emitting layer 130 of the second light-emitting device 102 may be as shown in Formula (RD-2).

[0268] In some embodiments, when the first host material RHP of the light-emitting layer 130 of the second light-emitting device 102 is selected from any one of the structures shown in general formula (V), R 23 、R 24 、R 25 、R 26 、R 27 and R 28 At least one of them contains deuterium.

[0269] Since the atomic weight of deuterium is twice that of hydrogen, the structure shown in formula (V) is 23 、R 24 、R 25 、R 26 、R 27 and R 28 In the case where at least one of the materials contains deuterium, the physical properties of the first main material RHP of the light-emitting layer 130 of the second light-emitting device 102 will change. Specifically, after the first main material RHP of the light-emitting layer 130 of the second light-emitting device 102 is replaced by deuterium, molecular vibration can be effectively suppressed, bond length can be reduced, bond energy can be increased, and molecular stability can be improved. In this way, the thermal stability of the first main material RHP of the light-emitting layer 130 of the second light-emitting device 102 is improved, and the life of the second light-emitting device 102 can be increased.

[0270] In some examples, when R 25 、R 26 、R 27 and R 28 When deuterium is contained, the structural formula of the first host material RHP of the light-emitting layer 130 of the second light-emitting device 102 may be as shown in Formula (RHP-1).

[0271] In other examples, when R 23When deuterium is contained, the structural formula of the first host material RHP of the light-emitting layer 130 of the second light-emitting device 102 may be as shown in Formula (RHP-2).

[0272] In some embodiments, when the second host material RHN of the light-emitting layer 130 of the second light-emitting device 102 is selected from any one of the structures shown in formula (VI), L5, L6, L7, R 29 、R 30 and R 31 At least one of them contains deuterium.

[0273] Since the atomic weight of deuterium is twice that of hydrogen, L5, L6, L7, R 29 、R 30 and R 31 In the case where at least one of the materials contains deuterium, the physical properties of the second main material RHN of the light-emitting layer 130 of the second light-emitting device 102 will change. Specifically, after the second main material RHN of the light-emitting layer 130 of the second light-emitting device 102 is replaced by deuterium, molecular vibration can be effectively suppressed, bond length can be reduced, bond energy can be increased, and molecular stability can be improved. In this way, the thermal stability of the second main material RHN of the light-emitting layer 130 of the second light-emitting device 102 is improved, and the life of the second light-emitting device 102 can be increased.

[0274] In some examples, when R 29 When deuterium is contained, the structural formula of the second host material RHN of the light-emitting layer 130 of the second light-emitting device 102 may be as shown in Formula (RHN-1).

[0275] In some examples, when R 29 and R 31 When deuterium is contained, the structural formula of the second host material RHN of the light-emitting layer 130 of the second light-emitting device 102 may be as shown in Formula (RHN-2).

[0276] In other examples, when R 30 When deuterium is contained, the structural formula of the second host material RHN of the light-emitting layer 130 of the second light-emitting device 102 may be as shown in Formula (RHN-3).

[0277] In order to objectively evaluate the technical effects of the embodiment of the light-emitting substrate 200 including the first light-emitting device 101 of the present disclosure, the technical solutions provided by the present disclosure will be described in detail and exemplarily through the following experimental examples and comparative examples.

[0278] The following examples and comparative examples use different materials to form the light-emitting layer 130 of the first light-emitting device 101, and compare the voltage, current efficiency, color of emitted light, device life, and half-value width of the emission spectrum of the first light-emitting device 101. The color of the emitted light is represented by the chromaticity coordinates CIEx and CIEy in the CIE chromaticity diagram.

[0279] In the related art, the CIE chromaticity diagram is a color system created by the International Commission on Illumination (CIE), in which color attributes can be represented by chromaticity coordinates CIEx and CIEy.

[0280] In the following comparative examples and embodiments, the structure of the first light-emitting device 101 and the test conditions of the first light-emitting device 101 are the same.

[0281] Exemplarily, as shown in Figure 8, the preparation method of the light-emitting substrate 200 including the first light-emitting device 101 is as follows: a substrate 110 (glass substrate) provided with an array layer 310, a pixel defining layer 221 and an anode 110 (the material of the anode 110 is indium tin oxide) is used as a backplane, and the backplane is placed in a vacuum evaporation device, and the hole injection layer 141, the first hole transport layer 142, the second hole transport layer 143, the light-emitting layer 130, the hole blocking layer 153, the electron transport layer 152, the electron injection layer 151, the cathode 120, and the cathode covering layer 160 are sequentially formed on the backplane.

[0282] It should be noted that the thickness and materials of the anode 110, hole injection layer 141, first hole transport layer 142, second hole transport layer 143, hole blocking layer 153, electron transport layer 152, electron injection layer 151, cathode 120, and cathode covering layer 160 in the embodiment and the comparative example are the same, and the thickness of the light-emitting layer 130 is the same; the material of the light-emitting layer 130 is not exactly the same.

[0283] The light-emitting layer 130 in the following comparative example includes a comparative guest material, a comparative first host material, and a comparative first host material, wherein the structure of the comparative guest material is shown in formula (R-GD), the structure of the comparative first host material is shown in formula (R-GHP), and the structure of the comparative second host material is shown in formula (R-GHN).

[0284] It should be noted that (R-GHP) and (R-GHN) in the above structural formulas are aliases for each structural formula and are not part of the structural formula structure.

[0285] The materials of the light emitting layer 130 of the first light emitting device 101 of the embodiment and the comparative example are described below.

[0286] In Example 1, the light-emitting layer 130 includes a first host material GHP, a second host material GHN, and a guest material GD. The structural formula of the first host material GHP is shown as (GHP-1); the structural formula of the second host material GHN is shown as (GHN-1); and the structural formula of the guest material GD is shown as (GD-1). Furthermore, the mass ratio of the first host material GHP to the second host material GHN is 6:4, and the mass ratio of the guest material GD to the host material is 12%.

[0287] In Example 2, the light-emitting layer 130 includes a first host material GHP, a second host material GHN, and a guest material GD. The structural formula of the first host material GHP is shown as (GHP-2); the structural formula of the second host material GHN is shown as (GHN-2); and the structural formula of the guest material GD is shown as (GD-2). Furthermore, the mass ratio of the first host material GHP to the second host material GHN is 6:4, and the mass ratio of the guest material GD to the host material is 12%.

[0288] In Example 3, the light-emitting layer 130 includes a first host material GHP, a second host material GHN, and a guest material GD. The structural formula of the first host material GHP is shown as (GHP-3); the structural formula of the second host material GHN is shown as (GHN-3); and the structural formula of the guest material GD is shown as (GD-3). Furthermore, the mass ratio of the first host material GHP to the second host material GHN is 6:4, and the mass ratio of the guest material GD to the host material is 12%.

[0289] In Comparative Example 1, the light-emitting layer 130 includes a first host material GHP, a second host material GHN, and a guest material GD. The structural formula of the first host material GHP is shown as (R-GHP); the structural formula of the second host material GHN is shown as (R-GHN); and the structural formula of the guest material GD is shown as (R-GD). Furthermore, the mass ratio of the first host material GHP to the second host material GHN is 6:4, and the mass ratio of the guest material GD to the host material is 12%.

[0290] In order to more clearly describe the differences in the structural formulas of the first host material GHP, the second host material GHN, and the guest material GD used in the examples and the comparative examples, the following Table 1 is used to more clearly show the structural formulas of the first host material GHP, the second host material GHN, and the guest material GD used in the examples and the comparative examples.

[0291] Table 1

[0292] It should be noted that "Ax" in Table 1 refers to the corresponding structural formula Ax. For example, the sub-grid corresponding to the first host material HP in Example 1 is "GHP-1," which means that the structural formula of the first host material GHP in the light-emitting layer 130 of Example 1 is shown as (GHP-1). The structural formulas represented by GHP-x, GHN-x, GD-x (x is a positive integer), R-GHP, R-GHN, and R-GD are as described above and are not repeated here.

[0293] The absolute value of the highest occupied molecular orbital energy level (HOMO), the absolute value of the lowest occupied molecular orbital energy level (LUMO), the triplet energy level (T1), and the orientation parameters of the first host material GHP, the second host material GHN, the guest material GD, the comparative guest material R-GD, the comparative first host material R-GHP, and the comparative second host material R-GHN shown in Table 1 are shown in Table 2.

[0294] Table 2

[0295] It should be noted that the absolute values ​​of the highest occupied molecular orbital (HOMO), lowest occupied molecular orbital (LUMO), and triplet energy levels (T1) in Table 2 are expressed in electron volts (eV). The structural formulas represented by GHP-x, GHN-x, GD-x (x is a positive integer), R-GHP, R-GHN, and R-GD are as described above and are not repeated here.

[0296] Based on the above materials, the first light-emitting device 101 of Examples 1 to 3 and Comparative Example 1 was tested for voltage (V), current efficiency (cd / A), emitted light color, device lifetime, and half-value width of the emission spectrum. The voltage (V), current efficiency (cd / A), and device lifetime data were compared with those of Example 1. The test results are shown in Table 3 below. Device lifetime is characterized by the parameter LT95, and emitted light color is represented by the chromaticity coordinates CIEx and CIEy in the CIE chromaticity diagram.

[0297] Table 3

[0298] As can be seen from Table 3, in Examples 1 to 3 and Comparative Example 1, the chromaticity coordinates CIEx of the color of the light emitted by the light-emitting layer 130 of the first light-emitting device 101 are all in the range of 0.244 to 0.246, and the chromaticity coordinates CIEy are all in the range of 0.712 to 0.715, indicating that the color of the light emitted by the light-emitting layer 130 of the first light-emitting device 101 in Examples 1 to 3 and Comparative Example 1 is green, which is the same as the preset color.

[0299] Compared with Comparative Example 1, please refer to Table 3. The current efficiency of Examples 1 to 3 is relatively high. This is because in the light-emitting layer 130 of the first light-emitting device 101 of Examples 1 to 3, the guest material GD is a tetradentate ligand material. Compared with the guest material R-GD (bidentate ligand material) in Comparative Example 1, the molecular rigidity of the guest material GD is relatively high, which makes the molecular orientation of the guest material GD relatively high and the light extraction efficiency relatively high. At the same time, the degree of freedom of the guest material GD is relatively small, the vibration and rotation of the tetradentate ligand are relatively small, the metal-ligand charge transfer of the ligand material and the non-radiative attenuation caused by the ligand center transition are relatively small, which increases the proportion of radiative transitions, making the current efficiency of the first light-emitting device 101 of Examples 1 to 3 relatively high. In addition, compared with Comparative Example 1, in Examples 1 to 3, in the light-emitting layer 130 of the first light-emitting device 101, the triplet energy levels of the first host material GHP and the second host material GHN are relatively high, making it difficult for the excitons on the guest material GD to flow back to the host material, reducing the quenching of the excitons, and thus improving the efficiency of the first light-emitting device 101.

[0300] As shown in Table 3, when comparing Examples 1 to 3 with Comparative Example 1, the device lifespans of Examples 1 to 3 are relatively long. This is because the guest material GD in the light-emitting layer 130 of the first light-emitting device 101 of Examples 1 to 3 is a tetradentate ligand material. Compared to the guest material R-GD (a bidentate ligand material) in Comparative Example 1, the molecular rigidity of the guest material GD is relatively high, which can reduce the amplitude of molecular torsional motion, resulting in relatively less bond breakage caused by molecular torsional motion, and thus improving the stability of the guest material GD.

[0301] As shown in Table 3, the half-maximum widths of the emission spectra of Examples 1 to 3 are relatively narrow when compared with Comparative Example 1. This is because the guest material GD in the light-emitting layer 130 of the first light-emitting device 101 of Examples 1 to 3 is a tetradentate ligand material. Compared to the guest material R-GD (a bidentate ligand material) in Comparative Example 1, the molecular rigidity of the guest material GD is relatively high, the molecular deformation in the excited state is relatively small, and the corresponding triplet split energy levels are relatively small. As a result, when the guest material GD emits light using triplet excitons, the corresponding wavelength band is relatively narrow, resulting in a relatively narrow peak in the emission spectrum of the light-emitting layer 130.

[0302] To demonstrate the effects achieved when the guest material GD of the light-emitting layer 130 of the first light-emitting device 101 is a tetradentate ligand material, the normalized exciton intensity at various locations along the second direction Y in the light-emitting layer 130 was measured, using Comparative Example 1 as a comparison. The results are shown in FIG10 . It should be noted that the normalized exciton intensity in FIG10 refers to the sum of the exciton intensities at all measurement points normalized to 1.

[0303] As shown in FIG10 , compared to the first light-emitting device 101 in Comparative Example 1, the region with higher exciton intensity in the light-emitting layer 130 of the first light-emitting device 101 in Example 1 is closer to the second hole transport layer 143. This indicates that compared to the first light-emitting device 101 in Comparative Example 1, the exciton recombination region in the light-emitting layer 130 of the first light-emitting device 101 in Example 1 is closer to the second hole transport layer 143. This indicates that when the guest material GD of the light-emitting device 100 is a tetradentate ligand material, the region where holes and electrons recombine to form excitons can be located closer to the hole transport functional layer 140. This improves energy utilization and the efficiency of the light-emitting device 100.

[0304] In order to objectively evaluate the technical effects of the embodiment of the light-emitting substrate 200 including the second light-emitting device 102 of the present disclosure, the technical solutions provided by the present disclosure will be described in detail and exemplarily through the following experimental examples and comparative examples.

[0305] The following examples and comparative examples use different materials to form the light-emitting layer 130 of the second light-emitting device 102, and compare the voltage, current efficiency, color of emitted light, device life, and half-value width of the emission spectrum of the second light-emitting device 102. The color of the emitted light is represented by the chromaticity coordinates CIEx and CIEy in the CIE chromaticity diagram.

[0306] In the following comparative examples and embodiments, the structure of the second light-emitting device 102 and the test conditions of the second light-emitting device 102 are the same.

[0307] Exemplarily, as shown in Figure 9, the preparation method of the light-emitting substrate 200 including the second light-emitting device 102 is as follows: a substrate 110 (glass substrate) provided with an array layer 310, a pixel defining layer 221 and an anode 110 (the material of the anode 110 is indium tin oxide) is used as a backplane, and the backplane is placed in a vacuum evaporation device, and the hole injection layer 141, the first hole transport layer 142, the second hole transport layer 143, the light-emitting layer 130, the hole blocking layer 153, the electron transport layer 152, the electron injection layer 151, the cathode 120, and the cathode covering layer 160 are sequentially formed on the backplane.

[0308] It should be noted that the thickness and materials of the anode 110, hole injection layer 141, first hole transport layer 142, second hole transport layer 143, hole blocking layer 153, electron transport layer 152, electron injection layer 151, cathode 120, and cathode covering layer 160 in the embodiment and the comparative example are the same, and the thickness of the light-emitting layer 130 is the same; the material of the light-emitting layer 130 is not exactly the same.

[0309] The light-emitting layer 130 in the following comparative example includes a comparative guest material, a comparative first host material, and a comparative first host material, wherein the structure of the comparative guest material is shown in formula (R-RD), the structure of the comparative first host material is shown in formula (R-RHP), and the structure of the comparative second host material is shown in formula (R-RHN).

[0310] It should be noted that (R-RHP) and (R-RHN) in the above structural formulas are aliases for each structural formula and are not part of the structural formula structure.

[0311] The materials of the light-emitting layer 130 of the second light-emitting device 102 of the embodiment and the comparative example are described below.

[0312] In Example 4, the light-emitting layer 130 includes a first host material RHP, a second host material RHN, and a guest material RD. The structural formula of the first host material RHP is shown as (RHP-1); the structural formula of the second host material RHN is shown as (RHN-1); and the structural formula of the guest material RD is shown as (RD-1). Furthermore, the mass ratio of the first host material RHP to the second host material RHN is 4:6, and the mass ratio of the guest material RD to the host material is 2%.

[0313] In Example 5, the light-emitting layer 130 includes a first host material RHP, a second host material RHN, and a guest material RD. The structural formula of the first host material RHP is shown as (RHP-2); the structural formula of the second host material RHN is shown as (RHN-2); and the structural formula of the guest material RD is shown as (RD-2). Furthermore, the mass ratio of the first host material RHP to the second host material RHN is 4:6, and the mass ratio of the guest material RD to the host material is 2%.

[0314] In Example 6, the light-emitting layer 130 includes a first host material RHP, a second host material RHN, and a guest material RD. The structural formula of the first host material RHP is shown as (RHP-3); the structural formula of the second host material RHN is shown as (RHN-3); and the structural formula of the guest material RD is shown as (RD-3). Furthermore, the mass ratio of the first host material RHP to the second host material RHN is 4:6, and the mass ratio of the guest material RD to the host material is 2%.

[0315] In Comparative Example 2, the light-emitting layer 130 includes a first host material RHP, a second host material RHN, and a guest material RD. The structural formula of the first host material RHP is shown as (R-RHP); the structural formula of the second host material RHN is shown as (R-RHN); and the structural formula of the guest material RD is shown as (R-RD). Furthermore, the mass ratio of the first host material RHP to the second host material RHN is 4:6, and the mass ratio of the guest material RD to the host material is 2%.

[0316] In order to more clearly describe the differences in the structural formulas of the first host material RHP, the second host material RHN and the guest material RD used in the embodiment and the comparative example, the following Table 1 is used to more clearly show the structural formulas of the first host material RHP, the second host material RHN and the guest material RD used in the embodiment and the comparative example.

[0317] Table 4

[0318] It should be noted that "Ax" in Table 4 refers to the corresponding structural formula Ax. For example, the subcell corresponding to the first host material HP in Example 1 is "RHP-1," which means that the structural formula of the first host material RHP in the light-emitting layer 130 of Example 1 is shown as (RHP-1). The structural formulas represented by RHP-x, RHN-x, RD-x (x is a positive integer), R-RHP, R-RHN, and R-RD are as described above and are not repeated here.

[0319] The absolute value of the highest occupied molecular orbital energy level (HOMO), the absolute value of the lowest occupied molecular orbital energy level (LUMO), the triplet energy level (T1), and the orientation parameters of the first host material RHP, the second host material RHN, the guest material RD, the comparative guest material R-RD, the comparative first host material R-RHP, and the comparative second host material R-RHN shown in Table 4 are shown in Table 5.

[0320] Table 5

[0321] It should be noted that the absolute values ​​of the highest occupied molecular orbital (HOMO), lowest occupied molecular orbital (LUMO), and triplet energy levels (T1) in Table 5 are expressed in electron volts (eV). The structural formulas represented by RHP-x, RHN-x, RD-x (x is a positive integer), R-RHP, R-RHN, and R-RD are as described above and are not further described here.

[0322] Based on the above materials, the second light-emitting device 102 of Examples 4 to 6 and Comparative Example 2 was tested for voltage (V), current efficiency (cd / A), emitted light color, device lifetime, and half-width of the emission spectrum. The voltage (V), current efficiency (cd / A), and device lifetime data were based on Example 4. The test results are shown in Table 6 below. Device lifetime is characterized by the parameter LT95, and emitted light color is represented by the chromaticity coordinates CIEx and CIEy in the CIE chromaticity diagram.

[0323] Table 6

[0324] As can be seen from Table 6, in Examples 4 to 6 and Comparative Example 2, the chromaticity coordinates CIEx of the color of the light emitted by the light-emitting layer 130 of the second light-emitting device 102 are all in the range of 0.680 to 0.682, and the chromaticity coordinates CIEy are all in the range of 0.309 to 0.320, indicating that the color of the light emitted by the light-emitting layer 130 of the second light-emitting device 102 in Examples 4 to 6 and Comparative Example 2 is all red, which is the same as the preset color.

[0325] As shown in Table 6, compared with Comparative Example 2, Examples 4 to 6 have relatively high current efficiencies. This is because in the light-emitting layer 130 of the second light-emitting device 102 of Examples 4 to 6, the guest material RD is a tetradentate ligand material. Compared with the guest material R-RD (bidentate ligand material) in Comparative Example 2, the molecular rigidity of the guest material RD is relatively high, resulting in a relatively high molecular orientation of the guest material RD and a relatively high light extraction efficiency. At the same time, the degree of freedom of the guest material RD is relatively small, the vibration and rotation of the tetradentate ligand are relatively small, the non-radiative attenuation caused by the metal-ligand charge transfer and ligand center transition of the ligand material is relatively small, and the proportion of radiative transition is increased, resulting in a relatively high current efficiency of the second light-emitting device 102 of Examples 1 to 3.

[0326] As shown in Table 6, compared with Comparative Example 2, Examples 4 to 6 have relatively longer device lifespans. This is because the guest material RD in the light-emitting layer 130 of the second light-emitting device 102 in Examples 4 to 6 is a tetradentate ligand material. Compared to the guest material R-RD (a bidentate ligand material) in Comparative Example 2, the molecular rigidity of guest material RD is relatively high, which can reduce the amplitude of molecular torsional motion, resulting in relatively less bond breakage caused by molecular torsional motion, and thus improving the stability of guest material RD.

[0327] Refer to Table 6 for Examples 4 to 6 and Comparative Example 2. The half-maximum widths of the emission spectra of Examples 4 to 6 are relatively narrow. This is because the guest material RD in the light-emitting layer 130 of the second light-emitting device 102 of Examples 4 to 6 is a tetradentate ligand material. Compared to the guest material R-RD (a bidentate ligand material) in Comparative Example 2, the molecular rigidity of the guest material RD is relatively high, the molecular deformation in the excited state is relatively small, and the corresponding triplet split energy levels are relatively small. As a result, when the guest material RD emits light using triplet excitons, the corresponding wavelength band is relatively narrow, resulting in a relatively narrow peak in the emission spectrum of the light-emitting layer 130.

[0328] As can be seen from the above embodiments and comparative examples, the present disclosure, by setting the guest material D of the light-emitting layer 130 as a tetradentate ligand material, can make the molecular rigidity of the guest material D relatively high, can improve the orientation of the guest material D, and effectively improve the luminous efficiency of the light-emitting device 100. Moreover, the present disclosure, by setting the guest material D of the light-emitting layer 130 as a tetradentate ligand material, can reduce the amplitude of the molecular torsional motion, can improve the stability of the guest material D, and can effectively improve the service life of the light-emitting device 100. At the same time, the present disclosure, by setting the guest material D of the light-emitting layer 130 as a tetradentate ligand material, the deformation of the molecule in the excited state is relatively small, and the corresponding triplet state split energy level is relatively small. When the guest material D uses triplet excitons to emit light, the peak of the emission spectrum of the light-emitting layer 130 is relatively narrow, and the color purity of the light-emitting device 100 can be effectively improved.

[0329] The above description is merely a specific embodiment of the present disclosure, but the scope of protection of the present disclosure is not limited thereto. Any changes or substitutions that a person skilled in the art can conceive within the technical scope disclosed in the present disclosure should be included within the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope of protection of the claims.

Claims

1. A light-emitting substrate, comprising: substrate; A plurality of light emitting devices are disposed on the substrate and arranged along a first direction, wherein the first direction is parallel to the plane where the substrate is located; Each of the plurality of light-emitting devices comprises a light-emitting layer, a material of the light-emitting layer of each of the plurality of light-emitting devices comprises a guest material, and the guest material is configured to emit light of a set wavelength; Wherein, the guest material of the light-emitting layer of at least one light-emitting device among the plurality of light-emitting devices is a tetradentate ligand material.

2. The light-emitting substrate according to claim 1, wherein: The material of the light-emitting layer of each of the plurality of light-emitting devices further includes a host material, wherein the host material includes a first host material and a second host material; In at least one of the multiple light-emitting devices, the difference between the triplet energy level of the first host material and the triplet energy level of the guest material is greater than or equal to 0.2 eV and less than or equal to 0.5 eV; the difference between the triplet energy level of the second host material and the triplet energy level of the guest material is greater than or equal to 0.2 eV and less than or equal to 0.5 eV.

3. The light-emitting substrate according to claim 2, wherein: The hole mobility of the first host material is greater than the hole mobility of the second host material; the electron mobility of the second host material is greater than the electron mobility of the second host material; In at least one light-emitting device among the multiple light-emitting devices, the absolute value of the difference between the highest occupied molecular orbital energy level of the first host material and the highest occupied molecular orbital energy level of the guest material is greater than or equal to 0.4 eV; the absolute value of the difference between the lowest unoccupied molecular orbital energy level of the second host material and the lowest unoccupied molecular orbital energy level of the guest material is greater than or equal to 0.1 eV.

4. The light-emitting substrate according to claim 2 or 3, wherein: In at least one light-emitting device among the plurality of light-emitting devices, an orientation parameter of the guest material in the host material is greater than or equal to -0.40 and less than or equal to -0.

10.

5. The light emitting substrate according to any one of claims 1 to 4, wherein The light emitting layer of at least one of the plurality of light emitting devices emits light with a half-peak width of a spectrum greater than or equal to 20 nm and less than or equal to 30 nm.

6. The light emitting substrate according to any one of claims 1 to 5, wherein Each of the plurality of light emitting devices further comprises: an anode, located on one side of the light-emitting layer; a cathode, located on the other side of the light-emitting layer; A hole transport functional layer, located between the anode and the light emitting layer, configured to transport holes and / or block electrons or excitons; An electron transport functional layer, located between the cathode and the light emitting layer, configured to transport electrons and / or block holes or excitons; Among them, in the light-emitting layer of at least one light-emitting device among the plurality of light-emitting devices, the region where the holes and the electrons recombine to form excitons is located on a side close to the hole transport functional layer.

7. The light-emitting substrate according to any one of claims 1 to 6, wherein The multiple light-emitting devices include a first light-emitting device, a second light-emitting device, and a third light-emitting device arranged along a first direction; wherein the first light-emitting device is configured to emit light of a first wavelength, which is green light; the second light-emitting device is configured to emit light of a second wavelength, which is red light; and the third light-emitting device is configured to emit light of a third wavelength, which is blue light.

8. The light-emitting substrate according to claim 7, wherein: The guest material of the light-emitting layer of the first light-emitting device is selected from any one of the structures represented by the following general formula (I); Wherein, X1 is selected from any one of oxygen and sulfur; R1, R2, R3, R4 and R5 are the same or different and are independently selected from any one of hydrogen, deuterium, substituted or unsubstituted methyl, substituted or unsubstituted ethyl, substituted or unsubstituted propyl, substituted or unsubstituted isopropyl, substituted or unsubstituted n-butyl, substituted or unsubstituted isobutyl, substituted or unsubstituted sec-butyl, substituted or unsubstituted tert-butyl, substituted or unsubstituted cyclopropyl, substituted or unsubstituted cyclobutyl, substituted or unsubstituted cyclopentyl, substituted or unsubstituted cyclohexyl and substituted or unsubstituted phenyl; n1 and n5 are the same or different and are independently selected from any one of 0, 1, 2, 3 and 4; n2 is selected from any one of 0, 1, 2, 3, 4 and 5; n3 and n4 are the same or different and are independently selected from any one of 0, 1, 2 and 3.

9. The light-emitting substrate according to claim 7 or 8, wherein: In the first light-emitting device, a mass ratio of the guest material to the host material is greater than or equal to 5% and less than or equal to 14%.

10. The light emitting substrate according to any one of claims 7 to 9, wherein The first host material of the light-emitting layer of the first light-emitting device is selected from any one of the structures represented by the following general formula (III); Wherein, L1 and L2 are the same or different and are independently selected from any one of substituted or unsubstituted phenylene, substituted or unsubstituted biphenylene and substituted or unsubstituted naphthylene; R 11 , R 12 , R 13 , R 14 , R 15 and R 16 are the same or different and are independently selected from any one of hydrogen, deuterium, substituted or unsubstituted methyl, substituted or unsubstituted ethyl, substituted or unsubstituted propyl, substituted or unsubstituted isopropyl, substituted or unsubstituted n-butyl, substituted or unsubstituted isobutyl, substituted or unsubstituted sec-butyl, substituted or unsubstituted tert-butyl, substituted or unsubstituted cyclopropyl, substituted or unsubstituted cyclobutyl, substituted or unsubstituted cyclopentyl, substituted or unsubstituted cyclohexyl and substituted or unsubstituted phenyl; n 11 and n 12 The same or different, each independently selected from any one of 0 and 1; n 13 and n 16 The same or different, each independently selected from any one of 0, 1, 2, 3 and 4; n 14 and n 15 are the same or different and are independently selected from any one of 0, 1 and 2.

11. The light emitting substrate according to claim 7 to 10, wherein: The second host material of the light-emitting layer of the first light-emitting device is selected from any one of the structures represented by the following general formula (IV); Wherein, L3 and L4 are the same or different and are independently selected from any one of substituted or unsubstituted phenylene, substituted or unsubstituted biphenylene and substituted or unsubstituted naphthylene; R 17 , R 18 , R 19 , R 20 , R 21 and R 22 are the same or different and are independently selected from any one of substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted dimethylfluorenyl, substituted or unsubstituted diphenylfluorenyl, substituted or unsubstituted benzothiophenyl, substituted or unsubstituted benzoxazolyl and substituted or unsubstituted benzimidazolyl; n 17 and n 18 The same or different, each independently selected from any one of 0 and 1; n 20 and n 22 The same or different, each independently selected from any one of 0, 1, 2, 3 and 4; n 21 Select any one of 0, 1 and 2.

12. The light emitting substrate according to any one of claims 7 to 11, wherein In the first light-emitting device, a mass ratio between the first host material and the second host material is greater than or equal to 1:1 and less than or equal to 7:

3.

13. The light emitting substrate according to any one of claims 7 to 12, wherein The guest material of the light-emitting layer of the second light-emitting device is selected from any one of the structures represented by the following general formula (II); Wherein, X2 is selected from any one of oxygen and sulfur; Ar1 is selected from any one of a substituted or unsubstituted benzene ring and a substituted or unsubstituted naphthalene ring; R6, R7, R8, R9 and R 10 are the same or different and are independently selected from any one of hydrogen, deuterium, substituted or unsubstituted methyl, substituted or unsubstituted ethyl, substituted or unsubstituted propyl, substituted or unsubstituted isopropyl, substituted or unsubstituted n-butyl, substituted or unsubstituted isobutyl, substituted or unsubstituted sec-butyl, substituted or unsubstituted tert-butyl, substituted or unsubstituted cyclopropyl, substituted or unsubstituted cyclobutyl, substituted or unsubstituted cyclopentyl, substituted or unsubstituted cyclohexyl and substituted or unsubstituted phenyl; n6 is selected from any one of 0, 1, 2, 3 and 4; n7 is selected from any one of 0, 1, 2, 3, 4 and 5; n8 and n9 are the same or different and are independently selected from any one of 0, 1, 2 and 3; n 10 Select any one of 0, 1 and 2.

14. The light emitting substrate according to claim 13, wherein: The guest material of the light-emitting layer of the second light-emitting device is selected from any one of the structures represented by the following general formula (II-A); Wherein, X3 is selected from any one of oxygen and sulfur.

15. The light emitting substrate according to any one of claims 7 to 14, wherein In the second light-emitting device, a mass ratio of the guest material to the host material is greater than or equal to 1% and less than or equal to 5%.

16. The light emitting substrate according to any one of claims 7 to 15, wherein The first host material of the light-emitting layer of the second light-emitting device is selected from any one of the structures represented by the following general formula (V); Among them, R 23 , R 24 , R 25 , R 26 , R 27 and R 28 The same or different, each independently selected from hydrogen, deuterium, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C1-C6 cycloalkyl, substituted or unsubstituted phenyl, substituted or Any one of an unsubstituted naphthyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothienyl group, and a substituted or unsubstituted carbazolyl group; n 23 and n 24 The same or different, each independently selected from any one of 0, 1, 2, 3, 4 and 5; n 25 and n 28 The same or different, each independently selected from any one of 0, 1, 2, 3 and 4; n 26 and n 27 are the same or different and are independently selected from any one of 0, 1 and 2.

17. The light emitting substrate according to any one of claims 7 to 16, wherein The second host material of the light-emitting layer of the second light-emitting device is selected from any one of the structures represented by the following general formula (VI); wherein L5, L6 and L7 are the same or different and are independently selected from any one of substituted or unsubstituted phenylene, substituted or unsubstituted biphenylene, substituted or unsubstituted naphthylene, substituted or unsubstituted dibenzofuranylene, substituted or unsubstituted benzodibenzofuranylene, substituted or unsubstituted dibenzothienylene, substituted or unsubstituted benzodibenzothienylene, substituted or unsubstituted carbazolylene, substituted or unsubstituted benzocarbazolylene and substituted or unsubstituted phenanthroxazolyl; R 29 , R 30 and R 31 are the same or different and are independently selected from any one of substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted benzodibenzofuranyl, substituted or unsubstituted dibenzothienyl, substituted or unsubstituted benzodibenzothienyl, substituted or unsubstituted carbazolyl, substituted or unsubstituted benzocarbazolyl and substituted or unsubstituted phenanthroxazolyl; n 29 、n 30 and n 31 are the same or different, and are independently selected from any one of 0 and 1.

18. The light emitting substrate according to any one of claims 7 to 17, wherein In the second light-emitting device, a mass ratio between the first host material and the second host material is greater than or equal to 3:7 and less than or equal to 1:

1.

19. The light emitting substrate according to any one of claims 7 to 18, wherein In the case where the guest material of the light-emitting layer of the first light-emitting device is selected from any one of the structures represented by general formula (I), at least one of R1, R2, R3, R4 and R5 contains deuterium; and / or, The first host material of the light-emitting layer of the first light-emitting device is selected from any one of the structures shown in general formula (III): In this case, L1, L2, R 11 , R 12 , R 13 , R 14 , R 15 and R 16 at least one of which contains deuterium; and / or In the case where the second host material of the light-emitting layer of the first light-emitting device is selected from any one of the structures shown in general formula (IV), L3, L4, R 17 , R 18 , R 19 , R 20 , R 21 and R 22 at least one of which contains deuterium; and / or In the case where the guest material of the light-emitting layer of the second light-emitting device is selected from any one of the structures represented by general formula (II) or general formula (II-A), Ar1, R6, R7, R8, R9 and R 10 at least one of which contains deuterium; and / or In the case where the first host material of the light-emitting layer of the second light-emitting device is selected from any one of the structures shown in general formula (V), R 23 , R 24 , R 25 , R 26 , R 27 and R 28 at least one of which contains deuterium; and / or In the case where the second host material of the light-emitting layer of the second light-emitting device is selected from any one of the structures shown in general formula (VI), L5, L6, L7, R 29 , R 30 and R 31 At least one of them contains deuterium.

20. The light emitting substrate according to any one of claims 7 to 19, wherein The half-peak width of the spectrum of light emitted by the light-emitting layer of the second light-emitting device is smaller than the half-peak width of the spectrum of light emitted by the light-emitting layer of the first light-emitting device.

21. A display panel, comprising the light-emitting substrate according to any one of claims 1 to 20; Also includes: A plurality of pixel driving circuits, each of which is electrically connected to one of the light emitting devices and is used to drive the light emitting device to emit light.

22. A display device comprising the display panel according to claim 21; Also includes: A driving chip is used to drive the display panel to display.

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