Light-emitting substrate, display panel and display device

Abstract

The embodiment of the invention provides a light-emitting substrate, a display panel and a display device, relates to the technical field of display, and is used for improving the light-emitting efficiency, the service life and the color purity of a light-emitting device. The light-emitting substrate comprises a substrate and a plurality of light-emitting devices. The plurality of light-emitting devices are arranged on the substrate and are arranged along a first direction, and the first direction is parallel to a plane where the substrate is located; each of the plurality of light-emitting devices includes a light-emitting layer, a 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; wherein the guest material of the light-emitting layer of at least one of the plurality of light-emitting devices is a tetradentate ligand material. The light-emitting substrate is used for displaying images.

Description

Technical Field

[0001] 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

[0002] 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. Summary of the invention

[0003] The purpose of the embodiments of the present disclosure is to provide a light-emitting substrate, a display panel and a display device, which are used to improve the light-emitting efficiency, lifespan and color purity of a light-emitting device.

[0004] To achieve the above objectives, the embodiments of the present disclosure provide the following technical solutions:

[0005] In one aspect, a light-emitting substrate is provided. The light-emitting substrate comprises 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, the first direction being parallel to the plane where the substrate is located; each of the plurality of light-emitting devices comprises a light-emitting layer, the 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 of the plurality of light-emitting devices is a tetradentate ligand material.

[0006] It can be understood that the design of the tetradentate ligand 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 can be relatively small, the vibration and rotation of the tetradentate ligand can be reduced, the non-radiative attenuation caused by the metal-to-ligand charge transfer (MLCT) of the ligand material and the ligand center (LC) transition can be reduced, and the proportion of radiative transition can be increased, so that the luminous efficiency of the light-emitting device can be effectively improved. Second, the tetradentate ligand can maintain a square planar configuration, so that the orientation of the guest material is improved, so that more molecules in the guest material can emit light in a direction perpendicular to the substrate, which can increase the light extraction efficiency of the guest material, and effectively improve the luminous efficiency of the light-emitting device. Third, when the molecular rigidity of the guest material is relatively high, the amplitude of the molecular torsional motion can be reduced, so that the bond breakage caused by the molecular torsional motion is relatively small, the stability of the guest material can be improved, and the service life of the light-emitting device can be effectively improved. Fourth, when the molecular rigidity of the guest material is relatively high, the deformation of the molecule in the excited state is relatively small, and the corresponding triplet split energy levels are relatively small, so that when the guest material uses triplet excitons to emit light, the corresponding band is relatively narrow, and the peak of the emission spectrum of the light-emitting layer is relatively narrow, and the color purity of the light-emitting device can be effectively improved. It can be seen that by setting the guest material of the light-emitting layer of at least one light-emitting device among the multiple light-emitting devices as a tetradentate ligand material, the luminous efficiency, service life, and color purity of at least one light-emitting device among the multiple light-emitting devices can be improved.

[0007] In some embodiments, the material of the light-emitting layer of each of 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 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 0.2eV and less than or equal to 0.5eV; 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 0.2eV and less than or equal to 0.5eV.

[0008] 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 plurality of 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.

[0009] 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.

[0010] In some embodiments, a 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.

[0011] 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.

[0012] In some embodiments, a 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.

[0013] 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).

[0014]

[0015] 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.

[0016] 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%.

[0017] 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).

[0018]

[0019] 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 The same or different, each independently selected from any one of 0, 1 and 2.

[0020] 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).

[0021]

[0022] 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 of 0, 1 and 2.

[0023] 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.

[0024] 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).

[0025]

[0026] 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. n 10 Select any one of 0, 1 and 2.

[0027] 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).

[0028]

[0029] Wherein, X3 is selected from any one of oxygen and sulfur.

[0030] 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%.

[0031] 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).

[0032]

[0033] 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 dibenzothienyl 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.

[0034] 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).

[0035]

[0036] 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. 29 , R 30 and R 31are 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. 29 、n 30 and n 31 are the same or different, and are independently selected from any one of 0 and 1.

[0037] 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.

[0038] 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 shown in general formula (I), at least one of R1, R2, R3, R4 and R5 contains deuterium; and / or,

[0039] 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

[0040] 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

[0041] 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 the general formula (II) or the general formula (II-A), Ar1, R6, R7, R8, R9 and R 10 at least one of which contains deuterium; and / or

[0042] 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 R28 at least one of which contains deuterium; and / or

[0043] 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.

[0044] In some embodiments, 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.

[0045] In another aspect, a display panel is provided, comprising: a light-emitting substrate as described in any of the above embodiments and a plurality of pixel driving circuits, wherein each of the plurality of pixel driving circuits is electrically connected to a light-emitting device and is used to drive the light-emitting device to emit light.

[0046] The beneficial effects that can be achieved by the display panel provided by some embodiments of the present disclosure are the same as the beneficial effects that can be achieved by a light-emitting device provided by the above technical solution, and will not be repeated here.

[0047] In another aspect, a display device is provided, the display device comprising: a display panel and a driving chip as described in any of the above embodiments. The driving chip is used to drive the display panel to display.

[0048] The beneficial effects that can be achieved by the display device provided by some embodiments of the present disclosure are the same as the beneficial effects that can be achieved by a display panel provided by the above technical solution, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions in the present disclosure, the following briefly introduces the drawings required to be used in some embodiments of the present disclosure. Obviously, the drawings described below are only drawings of some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can also be obtained based on these drawings. In addition, the drawings described below can be regarded as schematic diagrams, and are not limitations on the actual size of the product involved in the embodiments of the present disclosure, the actual process of the method, the actual timing of the signal, etc.

[0050] Figure 1 is a structural diagram of a display device according to some embodiments;

[0051] Figure 2 is a structural diagram of a display panel according to some embodiments;

[0052] Figure 3 is a structural diagram of a light-emitting substrate according to some embodiments;

[0053] Figure 4 is a structural diagram of a light-emitting substrate according to some further embodiments;

[0054] Figure 5 is a structural diagram of a light-emitting substrate according to some further embodiments;

[0055] Figure 6 is a comparison diagram of exciton recombination areas according to some embodiments;

[0056] Figure 7 is a comparison diagram of the highest occupied molecular orbital energy level and the lowest unoccupied molecular orbital energy level according to some embodiments;

[0057] Figure 8 is a structural diagram of a light-emitting substrate according to some further embodiments;

[0058] Fig. 9 is a structural diagram of a light-emitting substrate according to some other embodiments;

[0059] Fig.10 is a graph showing a change in normalized exciton intensity versus exciton recombination area according to some embodiments;

[0060] Fig.11 is a diagram of an energy transfer process according to some embodiments. DETAILED DESCRIPTION

[0061] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present disclosure.

[0062] Unless the context requires otherwise, throughout the specification and claims, the term "comprise" and other forms thereof, such as the third person singular form "comprises" and the present participle form "comprising", are to be interpreted as open, 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" and the like are intended to indicate that specific 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 specific features, structures, materials or characteristics may be included in any one or more embodiments or examples in any appropriate manner.

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

[0064] “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.

[0065] “A and / or B” includes the following three combinations: A only, B only, and a combination of A and B.

[0066] As used herein, "about," "substantially," or "approximately" includes the stated value and an average value that is within an acceptable range of variation 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).

[0067] 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 the acceptable deviation range, wherein the acceptable deviation range is 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 a particular 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 may be, for example, a deviation within 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, wherein the acceptable deviation range of approximate perpendicularity may also be, for example, a deviation within 5°. "Equal" includes absolute equality and approximate equality, wherein the acceptable deviation range of approximate equality may be, for example, the difference between the two equalities is less than or equal to 5% of either one.

[0068] It will be understood that when a layer or an 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 between the layer or element and the other layer or substrate.

[0069] Exemplary embodiments are described herein with reference to cross-sectional views and / or plan views that are idealized exemplary drawings. In the drawings, the thickness of the layers and the area of ​​the regions are exaggerated for clarity. Therefore, variations in the shapes relative to the drawings due to, for example, manufacturing techniques and / or tolerances are conceivable. Therefore, the exemplary embodiments should not be interpreted as being limited to the shapes of the regions shown herein, but include shape deviations 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 shapes of the regions of the device, and are not intended to limit the scope of the exemplary embodiments.

[0070] It should be noted that, for example, 11-1 in the drawings of the present disclosure indicates that component 11 belongs to component 1, for example, Figure 2 220-200 indicates that the light-emitting functional layer 220 belongs to the light-emitting substrate 200, and other similar reference numerals in the drawings also follow the above description. For example, 1 / 2 in the drawings of the present disclosure indicates that structure 1 and structure 2 can refer to the structure, for example, Figure 3 The reference numeral 101 / 100 indicates that both the first light emitting device 100 and the light emitting device 101 can refer to this structure, and other similar reference numerals appearing in the drawings also follow the above description.

[0071] like Figure 1 As shown, some embodiments of the present disclosure provide a display device 400 , which includes: a display panel 300 .

[0072] In some examples, the display device 400 may be, for example, an OLED (Organic Light Emitting Diode) display device 400 .

[0073] For example, Figure 1 As shown, the display device 400 further includes a driving chip 410. The driving chip 410 is used to drive the display panel 300 to display.

[0074] 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 a variety of different functions such as taking pictures, recording videos, fingerprint recognition or face recognition.

[0075] The display device 400 described above may be any display device 400 that displays, whether in motion (e.g., video) or fixed (e.g., still image) and whether textual or image. More specifically, it is contemplated that the display device 400 of the embodiments described may 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., odometer displays, etc.), navigators, cockpit controls and / or displays, displays of camera views (e.g., displays of rear-view 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.

[0076] In some embodiments, Figure 2 As shown, 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, and the light-emitting functional layer 220 includes a plurality of light-emitting devices 100, and the plurality of light-emitting devices 100 are arranged along a first direction X, and the first direction X is parallel to the plane where the substrate 210 is located.

[0077] In some examples, such as Figure 2 As shown, the display panel 300 further includes an array layer 310 disposed between the substrate 210 and the light-emitting functional layer 220, and 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, and is used to drive the light-emitting device 100 to emit light.

[0078] For example, Figure 2As shown, multiple pixel driving circuits 311 and multiple light emitting devices 100 may be coupled one-to-one. 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 .

[0079] Exemplarily, 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, and the lights emitted by the multiple light emitting devices 100 cooperate with each other, so that the display panel 300 realizes the display function.

[0080] In some examples, such as Figure 2 As shown, 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 .

[0081] 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 and damaging the organic material in the light-emitting device 100, thereby shortening the life of the OLED display panel 300.

[0082] In some embodiments, Figure 2 and Figure 3 As shown, in the light-emitting substrate 200 , the light-emitting functional layer 220 further includes a pixel defining layer 221 disposed on one side of the substrate 210 . The pixel defining layer 221 has a plurality of openings Q. The plurality of light-emitting devices 100 can be disposed correspondingly to the plurality of openings Q one by one.

[0083] In some embodiments, Figure 3 to Figure 5 As shown, 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.

[0084] 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 (gray scale) 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.

[0085] It should be noted that Figure 4-5 This is a simplified schematic diagram obtained after removing other film layers in the light-emitting substrate 200 except for the film layers related to the light-emitting device 100. Figure 4-5 In the embodiment, the plurality of 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 .

[0086] 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, and the second direction Y intersects the first direction X.

[0087] For example, Figure 4-5 As shown, the second direction Y is perpendicular to the first direction X.

[0088] 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, so that an electric field is generated between the two, which can drive the holes of the anode 110 and the electrons of the cathode 120 to recombine in the light-emitting layer 130, thereby emitting light.

[0089] Exemplarily, 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, so that 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.

[0090] 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.

[0091] 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.

[0092] In some embodiments, Figure 8 and Fig. 9 As shown, in the light-emitting substrate 200, a cathode covering layer 160 is further provided between the encapsulation layer 320 and the cathode 120. The material forming the cathode covering layer 160 is, for example, a material with a high refractive index. By providing the cathode covering layer 160, the high refractive performance of the material can be utilized to improve the light extraction efficiency of the light-emitting device, and the efficiency of the light-emitting device 100 and the brightness when lit can be improved.

[0093] It should be noted that Figure 8-Figure 9 This is a simplified schematic diagram obtained after removing other film layers in the light-emitting substrate 200 except for the film layers related to the light-emitting device 100. Figure 8 In the embodiment, the plurality of light emitting devices 100 are, for example, first light emitting devices 101; Fig. 9 In the embodiment, the plurality of light emitting devices 100 are, for example, second light emitting devices 102 .

[0094] In some embodiments, Figure 4-5 As shown, 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 hole injection layer 141 (Hole Inject Layer, HIL) and a hole transport layer (Hole Transport Layer, HTL) stacked. Among them, the hole transport layer (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.

[0095] In some embodiments, in order 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 an electron injection layer 151, an electron transport layer 152, and a 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.

[0096] 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 barrier height that needs to be overcome for carrier transition, thereby making the light-emitting efficiency higher.

[0097] 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, block electrons and excitons generated in the light-emitting layer 130.

[0098] Exemplarily, the electron transport functional layer 150 is configured to transport electrons and / or block holes or excitons. For example, the hole blocking layer 153 may be configured to block holes and excitons generated in the light emitting layer 130 .

[0099] In some embodiments, the cathode 120 stacked with each light-emitting layer 130 is a structure in which the entire layer is connected, 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 in which the entire layer is connected, 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.

[0100] For example, Figure 3As shown, 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 .

[0101] In other embodiments, Figure 5 As shown, 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 arranged. In this way, 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 .

[0102] 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.

[0103] Exemplarily, the light of the set wavelength may be green light; or, may be red light; or, may be blue light.

[0104] It can be understood that the guest material D is the material in the light emitting layer 130 that emits light.

[0105] 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.

[0106] 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.

[0107] Exemplarily, the first host material HP can be configured to: transport holes, and / or, recombining electrons and holes to form excitons, and transferring fluorescence resonance energy to the guest material D. At this time, the hole mobility of the first host material HP is greater than or equal to the hole mobility of the second host material HN.

[0108] Exemplarily, the second host material HN can be configured to: transport electrons, and / or, recombining electrons and holes to form excitons, and transfer fluorescence resonance energy to the guest material D. At this time, the electron mobility of the second host material HN is greater than or equal to the electron mobility of the first host material HP.

[0109] 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 combining electrons and holes.

[0110] As mentioned in the background, in the field of organic semiconductors, OLED technology has attracted more and more attention from academia and industry, and has been successfully applied in the commercial flat panel display and lighting industries. OLED light-emitting devices have the characteristics of self-luminescence. Accordingly, OLED display panels and OLED light-emitting substrates have the advantages of not requiring a backlight source, thin panels, and light weight. At the same time, OLED light-emitting devices also have the advantages of being all solid-state, fast response time, and a wide operating temperature range.

[0111] Among them, the different compositions of the compounds used in the organic material layers of OLED light-emitting devices will have a significant difference in the overall performance of the organic light-emitting devices. With the development of OLED light-emitting devices, the requirements for the efficiency, service life, power consumption, color purity and other performance of OLED light-emitting devices are getting higher and higher, and the existing organic materials can hardly meet the requirements of OLED light-emitting devices.

[0112] In the related art, a ligand material refers to a material having a ligand and a central atom in the structure, and the ligand and the central atom are connected by a coordination bond, wherein a ligand (also called a ligand) refers to 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 having at least one bidentate ligand in the structure.

[0113] In some implementations, the 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 a structure as shown in the following formula (R-GD) and (R-RD). In the formula (R-GD) and (R-RD), the central atom is iridium (Ir), and the central atom iridium is bonded to three bidentate ligands through ligand bonds. It can be seen from the structures shown in the formulas (R-GD) and (R-RD) that when the guest material D is a bidentate ligand material, the molecular rigidity of the guest material D is relatively low, and the degree of freedom is relatively large, so that the vibration and rotation of the ligand are increased.

[0114]

[0115] 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.

[0116] 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 through a ligand bond. Here, the type of the central atom can be metal or metalloid, and there is no limitation here. In this case, the guest material D is a phosphorescent material.

[0117] 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 comprising at least one tetradentate ligand.

[0118] It can be understood that, compared with the case where the guest material is a bidentate ligand material in some implementations, the design of the tetradentate ligand 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 relatively small, the vibration and rotation of the tetradentate ligand can be reduced, the non-radiative attenuation caused by the metal-to-ligand charge transfer (MLCT) of the ligand material and the ligand center (LC) transition can be reduced, and the proportion of radiative transitions can be increased, so that the luminous efficiency of the light-emitting device 100 is 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, so that the bond breakage caused by the molecular torsional motion is relatively small, the stability of the guest material D can be improved, and the service life of the light-emitting device 100 can be effectively improved. Fourth, when the molecular rigidity of the guest material D is relatively high, the deformation of the molecule in the excited state is relatively small, and the corresponding triplet split energy level is relatively small, so that when the guest material D uses triplet excitons to emit light, the corresponding band is relatively narrow, so that 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.

[0119] 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.

[0120] 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; 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.

[0121] It can be 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, and 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 arrangement, 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 be higher than the triplet energy level T1(D) of the guest material D, so that 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, so that energy transfer from the exciplex HP / HN to the guest material D is realized, and exciton quenching caused by exciton backflow during energy transfer can be prevented, so that the efficiency of the light-emitting device 100 is improved. On the other hand, the difference between the triplet energy level T1(HP / HN) of the excited base 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 transfer, and improving the efficiency of the light-emitting device 100.

[0122] 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.

[0123] 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 0.2eV, 0.3eV, 0.35eV, 0.4eV or 0.5eV, etc.

[0124] Here, among the multiple light-emitting devices 100, the light-emitting device 100 in which the guest material D of the light-emitting layer 130 is a tetradentate ligand material is defined as a light-emitting device 100A. Among the multiple light-emitting devices 100, the light-emitting device 100 that satisfies 0.2eV≤T1(HP)-T1(D)≤0.5eV and 0.2eV≤T1(HN)-T1(D)≤0.5eV is defined as a 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 may be the same light-emitting device 100 or different light-emitting devices 100.

[0125] 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 , a region where holes and electrons recombine to form excitons is located on a side close to the hole transport functional layer.

[0126] 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.

[0127] It is understandable that if Figure 6 As shown, 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 Figure 6 When the K1 position is shown in FIG, compared with the region where holes and electrons recombine to form excitons located in the middle of the light-emitting layer 130 (as shown in FIG. Figure 6 In the case of the K2 position shown in the figure, holes and electrons can not only recombine to form excitons on the exciplex HP / HN, but also recombine to form excitons on the exciplex PR / HN, so that the energy utilization rate can be improved, and the efficiency of the light-emitting device 100 can be improved. Therefore, by setting the area 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 located on a side 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.

[0128] Here, among the plurality of light-emitting devices 100, the light-emitting device 100 that satisfies the requirement that the region where holes and electrons in the light-emitting layer 130 are combined 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 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, three or any two thereof, may be the same light-emitting device 100 or different light-emitting devices 100.

[0129] 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; 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. That is, |HOMO(HP)-HOMO(D)|≥0.4 eV, and |LUMO(HN)-LUMO(D)|≥0.1 eV.

[0130] 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 correspondingly, 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 exciton complex 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 energy utilization, and improve the efficiency of the light-emitting device 100; on the other hand, since the hole transport performance is relatively low, 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 exciton complex HP / HN, or on the exciton complex PR / HN, which can improve energy utilization, and improve the efficiency of the light-emitting device 100.

[0131] 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.

[0132] 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 0.1 eV, 0.15 eV, 0.2 eV, 0.25 eV or 0.3 eV, etc.

[0133] Here, among the plurality of light-emitting devices 100, the light-emitting device 100 that satisfies |HOMO(HP)-HOMO(D)|≥0.4eV and |LUMO(HN)-LUMO(D)|≥0.1eV is defined as a light-emitting device 100D. It should be noted that 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.

[0134] 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; 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.

[0135] 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 as shown in the figure) and a bidentate ligand material (R-GD as 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 FIG. Figure 7 shown.

[0136] It should be noted that Figure 7 In the box outside each material, the upper box edge represents the highest occupied molecular orbital energy level HOMO of the material, and the lower box edge represents the lowest unoccupied molecular orbital energy level LUMO of the material; the left box edge and the right box edge are to form a schematic diagram of the package and have no actual meaning. Fig. 9 The guest material GD and the guest material R-GD are arranged on the left and right to more clearly illustrate the highest occupied molecular orbital energy level HOMO and the lowest unoccupied molecular orbital energy level LUMO of the two materials, and it has no practical meaning.

[0137] Depend on Figure 7As shown, 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)|.

[0138] 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.

[0139] In the related art, the orientation parameter S can be used to characterize the anisotropy of the transition dipole moment vectors (TDMVs) of the molecule. The orientation parameter S can be calculated by the following formula:

[0140]

[0141] In the formula, <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 vertically, <cos 2 θ>=1, and S=1.

[0142] 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 make the guest material D have relatively more horizontally oriented molecules. Since the horizontally oriented molecules can emit light in a direction perpendicular to the substrate, the light emission direction is better and the light emission efficiency is higher. By 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, the light emission direction of the guest material D in the light-emitting layer 130 can be optimized, the light emission efficiency of the light-emitting device 100 can be improved, and the light emission efficiency of the light-emitting device 100 can be improved. Therefore, when the orientation parameter S of the guest material D in the host material in at least one of the multiple light-emitting devices 100 is greater than or equal to -0.40 and less than or equal to -0.10, the light emission efficiency of at least one of the multiple light-emitting devices 100 can be improved.

[0143] 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, −0.10, or the like.

[0144] Here, among the plurality of light-emitting devices 100, the light-emitting device 100 that satisfies the orientation parameter S of the guest material D in the host material being 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 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.

[0145] 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.

[0146] 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, and 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.

[0147] 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-peak width λ of a spectrum greater than or equal to 20 nm and less than or equal to 30 nm, that is, 20 nm≤λ≤30 nm.

[0148] It can be understood that when the half-peak 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 20nm and less than or equal to 30nm, the light emitted by the light-emitting layer 130 of the light-emitting device 100 has a higher color purity, which can improve the display performance of the light-emitting substrate 200. Therefore, by setting the half-peak width λ of the spectrum of light emitted by the light-emitting layer 130 of at least one light-emitting device 100 among the multiple light-emitting devices 100 to be greater than or equal to 20nm and less than or equal to 30nm, 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 a higher color purity.

[0149] Exemplarily, the light emitting layer 130 of at least one light emitting device 100 among the plurality of light emitting devices 100 may have a half-peak width λ of a spectrum of light emitted by 20 nm, 22 nm, 24 nm, 27 nm or 30 nm.

[0150] Here, among the plurality of light-emitting devices 100, the light-emitting device 100 that satisfies the half-peak width λ of the spectrum of the emitted light, which is 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 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.

[0151] 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 emits light with a half-peak width λ of a spectrum greater than or equal to 20 nm and less than or equal to 30 nm.

[0152] 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 relatively small, and the corresponding triplet splitting energy levels can be relatively small. When the guest material D utilizes triplet excitons to emit light, the corresponding band is relatively narrow, and the peak of the emission spectrum of the light-emitting layer 130 is relatively narrow, so that the color purity of the light-emitting device 100 can be effectively improved.

[0153] In some embodiments, when the plurality of light-emitting devices 100 include a first light-emitting device 101, a second light-emitting device 102, and a third light-emitting device 103, the half-peak 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-peak width λ1 of the spectrum of light emitted by the light-emitting layer 130 of the first light-emitting device 101. That is, λ2<λ1.

[0154] 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-peak 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-peak width λ1 of the spectrum of light emitted by the light-emitting layer 130 of the first light-emitting device 101.

[0155] 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.

[0156] 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).

[0157]

[0158] Wherein, X1 is selected from any one of oxygen and sulfur.

[0159] 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.

[0160] n1 and n5 are the same or different and are independently selected from any one of 0, 1, 2, 3 and 4.

[0161] n2 is selected from any one of 0, 1, 2, 3, 4 and 5.

[0162] n3 and n4 are the same or different and are independently selected from any one of 0, 1, 2 and 3.

[0163] It should be noted that in the structure shown in the 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.

[0164] It should be noted that when R1, R2, R3, R4 or R5 is selected from any one of a substituted methyl, a substituted ethyl, a substituted propyl, a substituted isopropyl, a substituted n-butyl, a substituted isobutyl, a substituted sec-butyl, a substituted tert-butyl, a substituted cyclopropyl, a substituted cyclobutyl, a substituted cyclopentyl, a substituted cyclohexyl and a substituted phenyl, the type of the substituent is not limited here.

[0165] It can be understood that the structure shown in the above general formula (I) is a structure with platinum as the central atom and contains a tetradentate ligand, and the tetradentate ligand is connected to the central atom through a coordination bond.

[0166] Based on the structure shown in general formula (I), the guest material GD can emit light of a first wavelength, and the light of the first wavelength is green light. Moreover, compared with the case where the guest material is a phosphorescent material containing a bidentate ligand (for example, the guest material R-GD) in some implementations, the design of the tetradentate ligand 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 GD is relatively high, and the tetradentate ligand can maintain a square planar configuration, so that the orientation of the guest material GD is improved, so that the luminous efficiency, service life, and color purity of the first light-emitting device 101 can be improved.

[0167] 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 shown in general formula (I) is described below.

[0168] 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.

[0169]

[0170] 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 may be as shown below.

[0171]

[0172] It should be noted that the above-listed structural formula is an example of the structure of the guest material GD of the light-emitting layer 130 of the first light-emitting device 101, and is not a limitation on the guest material GD of the light-emitting layer 130 of the first light-emitting device 101. Moreover, (GD-x) in the above structural formula is a synonym for each structural formula, and is not a part of the structural formula structure, wherein x is a positive integer.

[0173] 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%.

[0174] 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 GD , the mass m of the first main material GHP GHP , and the mass m of the second main material GHN GHN , satisfied with.

[0175]

[0176] 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 sufficient under the synergistic effect of the guest material GD and the host material, thereby improving the efficiency of the first light-emitting device 101.

[0177] Illustratively, 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%, etc.

[0178] 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).

[0179]

[0180] 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.

[0181] R 11 , R 12 , R 13 , R 14 , R15 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.

[0182] n 11 and n 12 are the same or different, and are independently selected from any one of 0 and 1.

[0183] n 13 and n 16 The same or different, each independently selected from any one of 0, 1, 2, 3 and 4.

[0184] n 14 and n 15 The same or different, each independently selected from any one of 0, 1 and 2.

[0185] It should be noted that here R 13 , R 14 , R 15 and R 16 The description of R1 can be found in the above description; 13 、n 14 、n 15 and n 16 For the description of n1, please refer to the above description of n1, which will not be repeated here.

[0186] 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 and R 11 Directly connected by a covalent bond (eg, a single bond). 12 When it is 0, the nitrogen and R 11Directly 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 remaining group after the hydrogen atom of a carbon atom on the benzene ring is removed. Phenylene refers to the general term for the remaining group 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, which 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.

[0187] 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 substituted methyl, substituted ethyl, substituted propyl, substituted isopropyl, substituted n-butyl, substituted isobutyl, substituted sec-butyl, substituted tert-butyl, substituted cyclopropyl, substituted cyclobutyl, substituted cyclopentyl, substituted cyclohexyl and substituted phenyl, the type of the substituent is not limited herein.

[0188] It can be understood that the structure shown in the general formula (III) above 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 above two carbazole groups connected by a single bond. In this way, the first main 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 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. Moreover, since the first light-emitting device 101 emits green light with a relatively small corresponding wavelength and a relatively high corresponding 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 property 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 easy to flow back 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.

[0189] 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 as shown in general formula (III) is described below.

[0190] 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 as shown below.

[0191]

[0192] It should be noted that the above-listed structural formula is an example of the structure of the first host material GHP of the light-emitting layer 130 of the first light-emitting device 101, and is not a limitation on the first host material GHP of the light-emitting layer 130 of the first light-emitting device 101. Moreover, (GHP-x) in the above structural formula is a synonym for each structural formula, and is not a part of the structural formula structure, wherein x is a positive integer.

[0193] 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).

[0194]

[0195] 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.

[0196] R 17 , R 18 , R 19 , R 20 , R 21 and R 22 The same or different, each 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.

[0197] n 17 and n 18 are the same or different, and are independently selected from any one of 0 and 1.

[0198] n 20 and n 22 The same or different, each independently selected from any one of 0, 1, 2, 3 and 4.

[0199] n 21 Select any one of 0, 1 and 2.

[0200] 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 For the description of n1, please refer to the above description of n1; 17 and n 18 The description of n can be found in the above 11 and n 12 description; it will not be repeated here.

[0201] 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 22 When 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.

[0202] 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 a higher electron transmission performance and plays the function of an electronic main body. 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, which transfers the exciton energy to the guest material DGD, thereby achieving the purpose of emitting light, and the efficiency of the first light-emitting device 101 can be improved.

[0203] Moreover, the structure shown in the above general formula (IV) contains an indolecarbazolyl group, that is, Moreover, the two nitrogen atoms in the indolecarbazole group are connected with substituents, which will produce a certain steric effect, reduce the molecular torsion of the second host material HN, and improve the triplet energy level T1 (GHN) of the second host material HN. Since the first light-emitting device 101 emits green light with a relatively small corresponding wavelength and a relatively high corresponding energy relative to other light-emitting devices 100 (for example, the second light-emitting device 102), when the second host material HN contains an indolecarbazole group, the triplet energy level T1 (GHN) of the second host material HN is relatively high, and the matching property with the first host material GHP 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 easy to flow back to the host material, and the quenching of the excitons is reduced, so that the efficiency of the first light-emitting device 101 can be improved.

[0204] In some examples, 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), the material of the light-emitting layer 130 of the first light-emitting device 101 is electroluminescent.

[0205] The energy transfer process is shown in the figure Fig.11 shown.

[0206] Depend on Fig.11 It can be seen that 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), the difference between the singlet energy level S1 and the triplet energy level T1 of the second host material GHN is relatively small; moreover, between the singlet energy level S1 and the triplet energy level T1 of the second host material GHN, there is not only intersystem crossing (ISC) but also reverse intersystem crossing (RISC), which can realize localized excited state, so that the second host material GHN has a certain thermally activated delayed fluorescence (TADF) effect. In this way, when the material of the light-emitting layer 130 of the first light-emitting device 101 is electroluminescent, the 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, realizing efficient energy transfer. Therefore, by configuring the second main 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.

[0207] 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 as shown in general formula (IV) is described below.

[0208] In some examples, when n 17 and n 18When all 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 as shown below.

[0209]

[0210] 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 as shown below.

[0211]

[0212] 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 as shown below.

[0213]

[0214] It should be noted that the above-listed structural formula is an example of the structure of the second host material GHN of the light-emitting layer 130 of the first light-emitting device 101, and does 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 structural formula is a synonym for each structural formula, and is not a part of the structural formula structure, wherein x is a positive integer.

[0215] 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.

[0216] It should be noted that the mass ratio between the first main material GHP and the second main material GHN is greater than or equal to 1:1 and less than or equal to 7:3, which means that the mass ratio of the first main material GHP is m GHP , and the mass m of the second main material GHN GHN , satisfied with.

[0217]

[0218] 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 transfer rate and the hole transfer 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.

[0219] 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, etc.

[0220] The above is an exemplary introduction to 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 is an exemplary introduction to 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.

[0221] 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).

[0222]

[0223] Wherein, X2 is selected from any one of oxygen and sulfur.

[0224] Ar1 is selected from any one of a substituted or unsubstituted benzene ring and a substituted or unsubstituted naphthalene ring.

[0225] 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.

[0226] n6 is selected from any one of 0, 1, 2, 3 and 4.

[0227] n7 is selected from any one of 0, 1, 2, 3, 4 and 5.

[0228] n8 and n9 are the same or different and are independently selected from any one of 0, 1, 2 and 3.

[0229] n 10 Select any one of 0, 1 and 2.

[0230] It should be noted that here R6, R7, R8, R9 and R 10 The description of n6, n7, n8, n9 and n 10 For the description of n1, please refer to the above description of n1, which will not be repeated here.

[0231] It should be noted that when R6, R7, R8, R9 or R 10 When the substituent is selected from any one of substituted methyl, substituted ethyl, substituted propyl, substituted isopropyl, substituted n-butyl, substituted isobutyl, substituted sec-butyl, substituted tert-butyl, substituted cyclopropyl, substituted cyclobutyl, substituted cyclopentyl, substituted cyclohexyl and substituted phenyl, the type of the substituent is not limited herein.

[0232] It should be noted that when Ar1 is selected from a substituted or unsubstituted benzene ring, the position of the common carbon atom between Ar1 and the six-membered heterocyclic ring E is not limited here. For example, the common carbon atom between Ar1 and the six-membered heterocyclic ring E can be carbon number 1 or 2, or carbon number 2 or 3, or carbon number 3 or 4. When Ar1 is selected from a substituted or unsubstituted naphthalene ring, the number and position of the common carbon atoms between Ar1 and the six-membered heterocyclic ring E are not limited here. For example, the number of common carbon atoms between Ar1 and the six-membered heterocyclic ring E can be two or three. Among them, when the number of common carbon atoms between Ar1 and the six-membered heterocyclic ring E is two, the common carbon atom between Ar1 and the six-membered heterocyclic ring E can be carbon number 1 or 2, or carbon number 2 or 3, or carbon number 3 or 4. When the number of the common carbon atoms between Ar1 and the six-membered heterocyclic ring E is three, the common carbon atoms between Ar1 and the six-membered heterocyclic ring E may be carbon atoms 1, 2, and 3, or carbon atoms 2, 3, and 4.

[0233] It can be understood that the structure shown in the general formula (II) is a structure with platinum as the central atom and contains a tetradentate ligand, and the tetradentate ligand is connected to the central atom through a coordination bond. Moreover, compared with the guest material GD of the light-emitting layer 130 of the first light-emitting device 101 having the structure shown in the general formula (I), the guest material RD of the light-emitting layer 130 of the second light-emitting device 102 having the structure shown in the general formula (II) has a six-membered heterocyclic ring E and Ar1 (benzene ring or naphthalene ring) fused, so that the wavelength of the 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 the light emitted by the guest material GD of the light-emitting layer 130 of the first light-emitting device 101, so that 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 of light is red light.

[0234] Moreover, based on the structure shown in the 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. In this way, the luminous efficiency, service life, and color purity of the second light-emitting device 102 can be improved.

[0235] An exemplary structure of the guest material RD of the light-emitting layer 130 of the second light-emitting device 102 having a structure as shown in general formula (II) is described below.

[0236] 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 may be as shown below.

[0237]

[0238] It should be noted that the above-listed structural formula is an example of the structure of the guest material RD of the light-emitting layer 130 of the second light-emitting device 102, and is not a limitation on the guest material RD of the light-emitting layer 130 of the second light-emitting device 102. Moreover, (RD-x) in the above structural formula is a synonym for each structural formula, and is not a part of the structural formula structure, wherein x is a positive integer.

[0239] 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).

[0240]

[0241] Wherein, X3 is selected from any one of oxygen and sulfur.

[0242] 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 Description of Ar1 here can refer to the above description of Ar1, which will not be repeated here.

[0243] It can be 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). Since X3 is connected between the six-membered carbon ring containing R8 and the six-membered carbon ring containing R9, the number of condensed rings on the tetradentate ligand increases, so 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 shown in general formula (II-A), compared with the case where 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 shown in general formula (II), the molecular rigidity of the guest material can be relatively high, so that the molecular orientation of the guest material is relatively high, so that the luminous efficiency, service life, and color purity of the second light-emitting device 102 can be improved.

[0244] An exemplary structure of the guest material RD of the light-emitting layer 130 of the second light-emitting device 102 having a structure as shown in the general formula (II-A) is described below.

[0245] 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 may be as shown below.

[0246]

[0247] 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 may be as shown below.

[0248]

[0249] It should be noted that the above-listed structural formula is an example of the structure of the guest material RD of the light-emitting layer 130 of the second light-emitting device 102, and is not a limitation on the guest material RD of the light-emitting layer 130 of the second light-emitting device 102. Moreover, (RD-x) in the above structural formula is a synonym for each structural formula, and is not a part of the structural formula structure, wherein x is a positive integer.

[0250] 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%.

[0251] 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 that the mass m of the guest material RD is RD , the mass m of the first main material RHP RHP , and the mass m of the second host material RHN RHN , satisfied with.

[0252]

[0253] 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, so that in the second light-emitting device 102, under the synergistic effect of the guest material RD and the host material, the sufficiency of energy transmission is relatively high, and the efficiency of the second light-emitting device 102 can be improved.

[0254] For example, in the second light-emitting device 102 , the mass ratio between the guest material RD and the host material is 1%, 2%, 3%, 3.5%, 4% or 5%, etc.

[0255] 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 shown in the following general formula (V).

[0256]

[0257] Among them, R 23 , R 24 , R 25 , R 26 , R 27 and R 28 The same or different, each 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.

[0258] n 23 and n 24 The same or different, each independently selected from any one of 0, 1, 2, 3, 4 and 5.

[0259] n 25 and n 28 The same or different, each independently selected from any one of 0, 1, 2, 3 and 4.

[0260] n 26 and n 27 are the same or different and are independently selected from any one of 0, 1 and 2.

[0261] 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 in the above description; 23 、n 24 、n 25 、n 26 、n 275 and n 28 For the description of n1, please refer to the above description of n1, which will not be repeated here.

[0262] 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 one 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 here. Among them, the alkyl of Cx refers to an alkyl group with a total of x carbon (C) atoms, x is a positive integer, and the same applies below. For the understanding of other cycloalkyl groups such as Cx, please refer to the above content and will not be repeated here.

[0263] 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 benzindolecarbazole-based structure, so that the first main 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 main material RHP and the second main material RHN can form an exciton complex RHP / RHN, which transfers the exciton energy to the guest material RD, thereby achieving the purpose of emitting light, and the efficiency of the second light-emitting device 102 can be improved. Moreover, since the second light-emitting device 102 emits red light with a relatively large corresponding wavelength and a relatively low corresponding energy compared to other light-emitting devices 100 (for example, the first light-emitting device 101), when the first main material RHP contains a planar group, namely a benzoindolecarbazole group, the molecular rigidity of the first main material RHP is relatively high, and the molecular orientation is relatively high, so that the triplet energy level T1 (RHP) of the first main material RHP is relatively low, and the matching with the second main material RHN 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.

[0264] 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) is described below.

[0265] 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 as shown below.

[0266]

[0267] 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 as shown below.

[0268]

[0269] 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 may be as shown below.

[0270]

[0271] It should be noted that the above-listed structural formula is an example of the structure of the first host material RHP of the light-emitting layer 130 of the second light-emitting device 102, and is not a limitation on the first host material RHP of the light-emitting layer 130 of the second light-emitting device 102. Moreover, (RHP-x) in the above structural formula is a synonym for each structural formula, and is not a part of the structural formula structure, wherein x is a positive integer.

[0272] 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).

[0273]

[0274] 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, substituted or unsubstituted carbazolylene, substituted, substituted or unsubstituted benzocarbazolylene and substituted, substituted or unsubstituted phenanthroxazolylene.

[0275] 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.

[0276] n 29 、n 30 and n 31 are the same or different, and are independently selected from any one of 0 and 1.

[0277] 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; it will not be repeated here.

[0278] It should be noted that when L5, L6 or L7 is selected from any one of substituted phenylene, substituted biphenylene, substituted naphthylene, substituted dibenzofuranylene, substituted benzodibenzofuranylene, substituted dibenzothienylene, substituted benzodibenzothienylene, substituted carbazolylene, substituted benzocarbazolylene and substituted phenanthroxazolyl, and / or R 29 , R 30 and R 31 When the substituent is selected from any one of a substituted phenyl, a substituted biphenyl, a substituted naphthyl, a substituted dibenzofuranyl, a substituted benzodibenzofuranyl, a substituted dibenzothiophenyl, a substituted benzodibenzothiophenyl, a substituted carbazolyl, a substituted benzocarbazolyl and a substituted phenanthroxazolyl, the type of the substituent is not limited here.

[0279] 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 a higher electron transmission 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, which transfers the exciton energy to the guest material RGD, thereby achieving the purpose of emitting light, and the efficiency of the second light-emitting device 102 can be improved.

[0280] Furthermore, in the structure represented by the above general formula (VI), R 29 , R 30 and R 31 The selection range includes phenyl, biphenyl, naphthyl, dibenzofuranyl, benzodibenzofuranyl, dibenzothiophene, benzodibenzothiophene, 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, and can reduce 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 small corresponding wavelength and a relatively high corresponding energy relative to other light-emitting devices 100 (for example, the first light-emitting device 101), when the second host material RHN contains the above-mentioned planar groups, the triplet energy level T1 (RHN) of the second host material RHN is relatively low, and the matching property 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, so that the efficiency of the second light-emitting device 102 can be improved.

[0281] 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 as shown in general formula (VI).

[0282] 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 as shown below.

[0283]

[0284] In some examples, when R 29 When it is phenyl, the structural formula of the second host material RHN of the light-emitting layer 130 of the second light-emitting device 102 can be as shown below.

[0285]

[0286] It should be noted that the above-listed structural formula is an example of the structure of the second host material RHN of the light-emitting layer 130 of the second light-emitting device 102, and is not a limitation on the second host material RHN of the light-emitting layer 130 of the second light-emitting device 102. Moreover, (RHN-x) in the above structural formula is a synonym for each structural formula, and is not a part of the structural formula structure, wherein x is a positive integer.

[0287] 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.

[0288] 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.

[0289]

[0290] 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 transfer rate and the hole transfer 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.

[0291] 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.

[0292] 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.

[0293] 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 the 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.

[0294] 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 may be as shown in Formula (GD-2).

[0295] 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.

[0296] 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 16In the case where at least one of the light emitting devices 101 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, 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 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.

[0297] 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).

[0298] In other examples, when R 12 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-3).

[0299] 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.

[0300] 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 light emitting devices 101 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, 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 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.

[0301] In some examples, when R 20 , R 21 and R22 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).

[0302] 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).

[0303] 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 the general formula (II) or the general formula (II-A), Ar1, R6, R7, R8, R9 and R 10 At least one of them contains deuterium.

[0304] Since the atomic weight of deuterium is twice that of hydrogen, Ar1, R6, R7, R8, R9 and R 10 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, 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 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.

[0305] 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).

[0306] 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.

[0307] Since the atomic weight of deuterium is twice that of hydrogen, R 23 , R 24 , R 25 , R 26 , R 27 and R 28In the case where at least one of the light emitting devices 102 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, 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 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.

[0308] 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).

[0309] In other examples, when R 23 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-2).

[0310] 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 general formula (VI), L5, L6, L7, R 29 , R 30 and R 31 At least one of them contains deuterium.

[0311] 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 light emitting devices 102 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, 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 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.

[0312] 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).

[0313] In some examples, when R 29 and R31 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).

[0314] 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).

[0315] In order to objectively evaluate the technical effect of the embodiment of the light-emitting substrate 200 including the first light-emitting device 101 of the present disclosure, the technical solution provided by the present disclosure will be described in detail and exemplarily through the following experimental examples and comparative examples.

[0316] The following embodiments and comparative examples use different materials to make the light-emitting layer 130 of the first light-emitting device 101, and compare the voltage, current efficiency, color of the emitted light, device life, and half-peak 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.

[0317] 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.

[0318] 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.

[0319] For example, Figure 8 As shown, 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 a hole injection layer 141, a first hole transport layer 142, a second hole transport layer 143, a light-emitting layer 130, a hole blocking layer 153, an electron transport layer 152, an electron injection layer 151, a cathode 120, and a cathode covering layer 160 are sequentially formed on the backplane.

[0320] 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 completely the same.

[0321] 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).

[0322]

[0323] 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.

[0324] 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.

[0325] 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); the structural formula of the guest material GD is shown as (GD-1). Moreover, the mass ratio between the first host material GHP and the second host material GHN is 6:4; the mass ratio between the guest material GD and the host material is 12%.

[0326] 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); the structural formula of the guest material GD is shown as (GD-2). Moreover, the mass ratio between the first host material GHP and the second host material GHN is 6:4; the mass ratio between the guest material GD and the host material is 12%.

[0327] 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); the structural formula of the guest material GD is shown as (GD-3). Moreover, the mass ratio between the first host material GHP and the second host material GHN is 6:4; the mass ratio between the guest material GD and the host material is 12%.

[0328] 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); the structural formula of the guest material GD is shown as (R-GD). Moreover, the mass ratio between the first host material GHP and the second host material GHN is 6:4; the mass ratio between the guest material GD and the host material is 12%.

[0329] 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 embodiments 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 embodiments and the comparative examples.

[0330] Table 1

[0331] First main material Second main material Object material Example 1 GHP-1 GHN-1 GD-1 Example 2 GHP-2 GHN-2 GD-2 Example 3 GHP-3 GHN-3 GD-3 Comparative Example 1 R-GHP R-GHN R-GD

[0332] It should be noted that "Ax" in Table 1 refers to the corresponding structural formula Ax. For example, the content of 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 refer to the above content and will not be repeated here.

[0333] 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 as shown in Table 2.

[0334] Table 2

[0335]

[0336]

[0337] It should be noted that the absolute value of the highest occupied molecular orbital energy level (HOMO), the absolute value of the lowest occupied molecular orbital energy level (LUMO), and the triplet energy level (T1) in Table 2 are in electron volts, with the symbol eV. The structural formulas represented by GHP-x, GHN-x, GD-x (x is a positive integer), R-GHP, R-GHN, and R-GD refer to the above content and will not be repeated here.

[0338] Based on the above materials, the voltage (V), current efficiency (cd / A), color of emitted light, device life and half-peak width of emission spectrum of the first light emitting device 101 of Examples 1 to 3 and Comparative Example 1 were tested. The data results of voltage (V), current efficiency (cd / A) and device life are based on Example 1, and the test results are shown in Table 3 below. The device life is characterized by the parameter LT95; the color of the emitted light is represented by the chromaticity coordinates CIEx and CIEy in the CIE chromaticity diagram.

[0339] Table 3

[0340] Voltage Current efficiency CIEx CIE LT95 Half peak width (nm) Example 1 100％ 100％ 0.245 0.715 100％ 27 Example 2 101％ 103％ 0.246 0.714 95％ 25 Example 3 100％ 99％ 0.244 0.712 106％ 26 Comparative Example 1 103％ 84％ 0.245 0.715 84％ 29

[0341] It can be seen from Table 3 that 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.

[0342] 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, so that the molecular orientation of the guest material GD is relatively high, and the light extraction efficiency is 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, and the non-radiative attenuation caused by the metal-ligand charge transfer of the ligand material and the ligand center transition is relatively small, which increases the proportion of radiative transitions, so that the current efficiency of the first light-emitting device 101 of Examples 1 to 3 is relatively high. In addition, compared with comparative example 1, in the light-emitting layer 130 of the first light-emitting device 101 of examples 1 to 3, the triplet energy levels of the first host material GHP and the second host material GHN are relatively high, so that the excitons on the guest material GD are not easy to flow back to the host material, which reduces the quenching of the excitons and can improve the efficiency of the first light-emitting device 101.

[0343] As shown in Table 3, compared with Comparative Example 1, Examples 1 to 3 have relatively long device lifespans. 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, and 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 can reduce the amplitude of the molecular torsional motion, make the bond breakage caused by the molecular torsional motion relatively less, and improve the stability of the guest material GD.

[0344] Compared with Comparative Example 1, please refer to Table 3. The half-peak widths of the emission spectra of Examples 1 to 3 are relatively narrow. 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, the molecular deformation in the excited state is relatively small, and the corresponding triplet split energy levels are relatively small, so that when the guest material GD uses 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.

[0345] In order to demonstrate the effect that can be 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 each position along the second direction Y in the light-emitting layer 130 is measured by comparing with Comparative Example 1. The results are as follows: Fig.10 As shown. Fig.10The normalized exciton intensity in refers to that the sum of the exciton intensities of all measurement points is normalized to 1.

[0346] Depend on Fig.10 It can be seen that, compared with 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 embodiment 1 is closer to the second hole transport layer 143; it shows that compared with 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 embodiment 1 is closer to the second hole transport layer 143. It can be seen 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 on the side close to the hole transport functional layer 140, so that the energy utilization rate can be improved, and the efficiency of the light-emitting device 100 can be improved.

[0347] In order to objectively evaluate the technical effect of the embodiment of the light-emitting substrate 200 including the second light-emitting device 102 of the present disclosure, the technical solution provided by the present disclosure will be described in detail and exemplarily through the following experimental examples and comparative examples.

[0348] The following embodiments and comparative examples use different materials to make the light-emitting layer 130 of the second light-emitting device 102, and compare the voltage, current efficiency, color of the emitted light, device life, and half-peak 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.

[0349] In the following comparative examples and embodiments, the structure of the second light emitting device 102 and the testing conditions of the second light emitting device 102 are the same.

[0350] For example, Fig. 9 As shown, 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 a hole injection layer 141, a first hole transport layer 142, a second hole transport layer 143, a light-emitting layer 130, a hole blocking layer 153, an electron transport layer 152, an electron injection layer 151, a cathode 120, and a cathode covering layer 160 are sequentially formed on the backplane.

[0351] 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 completely the same.

[0352] 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).

[0353]

[0354] 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.

[0355] 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.

[0356] 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); the structural formula of the guest material RD is shown as (RD-1). Moreover, the mass ratio between the first host material RHP and the second host material RHN is 4:6; the mass ratio between the guest material RD and the host material is 2%.

[0357] 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); the structural formula of the guest material RD is shown as (RD-2). Moreover, the mass ratio between the first host material RHP and the second host material RHN is 4:6; the mass ratio between the guest material RD and the host material is 2%.

[0358] 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); the structural formula of the guest material RD is shown as (RD-3). Moreover, the mass ratio between the first host material RHP and the second host material RHN is 4:6; the mass ratio between the guest material RD and the host material is 2%.

[0359] 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); the structural formula of the guest material RD is shown as (R-RD). Moreover, the mass ratio between the first host material RHP and the second host material RHN is 4:6; the mass ratio between the guest material RD and the host material is 2%.

[0360] 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 embodiments and the comparative examples, 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 embodiments and the comparative examples.

[0361] Table 4

[0362] First main material Second main material Object material Example 4 RHP-1 RHN-1 RD-1 Example 5 RHP-2 RHN-2 RD-2 Example 6 RHP-3 RHN-3 RD-3 Comparative Example 2 R-RHP R-RHN R-RD

[0363] It should be noted that "Ax" in Table 4 refers to the corresponding structural formula Ax. For example, the content of the sub-grid 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 refer to the above content and are not repeated here.

[0364] 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 as shown in Table 5.

[0365] Table 5

[0366] |HOMO|(eV) |LUMO|(eV) T1(eV) Orientation parameters RHP-1 5.30 2.30 2.39 - RHP-2 5.29 2.33 2.41 - RHP-3 5.28 2.31 2.40 - R-RHP 5.25 2.32 2.38 - RHN-1 5.91 2.64 2.40 - RHN-2 5.92 2.65 2.42 - RHN-3 5.90 2.66 2.41 - R-RHN 5.91 2.80 2.38 - RD-1 4.91 2.78 2.32 - RD-2 4.94 2.78 2.31 - RD-3 4.92 2.80 2.31 - R-RD 5.01 3.00 2.32 - RD-1 in RHP-1 / RHN-1 - - - -0.28 RD-2 in RHP-2 / RHN-2 - - - -0.30 RD-3 in RHP-3 / RHN-3 - - - -0.31 R-RD in R-RHP / R-RHN - - - -0.09

[0367] It should be noted that the absolute value of the highest occupied molecular orbital energy level (HOMO), the absolute value of the lowest occupied molecular orbital energy level (LUMO), and the triplet energy level (T1) in Table 5 are in electron volts, with the symbol eV. Among them, the structural formulas represented by RHP-x, RHN-x, RD-x (x is a positive integer), R-RHP, R-RHN, and R-RD refer to the above content and will not be repeated here.

[0368] Based on the above materials, the voltage (V), current efficiency (cd / A), color of emitted light, device life and half-peak width of emission spectrum of the second light emitting device 102 of Examples 4 to 6 and Comparative Example 2 were tested. The data results of voltage (V), current efficiency (cd / A) and device life are based on Example 4, and the test results are shown in Table 6 below. The device life is characterized by the parameter LT95; the color of the emitted light is represented by the chromaticity coordinates CIEx and CIEy in the CIE chromaticity diagram.

[0369] Table 6

[0370] Voltage Current efficiency CIEx CIE LT95 Half peak width (nm) Example 4 100％ 100％ 0.682 0.320 100％ 24 Example 5 100％ 101％ 0.681 0.319 98％ 24 Example 6 102％ 98％ 0.682 0.318 101％ 23 Comparative Example 2 104％ 86％ 0.680 0.309 88％ 28

[0371] It can be seen from Table 6 that 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 red, which is the same as the preset color.

[0372] Compared with Comparative Example 2, Examples 4 to 6, please refer to Table 6, the current efficiency of Examples 4 to 6 is relatively high. 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, and 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, so that the molecular orientation of the guest material RD is relatively high, the light extraction efficiency is relatively high, and 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 metal-ligand charge transfer of the ligand material and the non-radiative attenuation generated by the ligand center transition are relatively small, which increases the proportion of radiative transitions, so that the current efficiency of the second light-emitting device 102 of Examples 1 to 3 is relatively high.

[0373] As shown in Table 6, compared with Comparative Example 2, Examples 4 to 6 have relatively long device lifespans. 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, and 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, which can reduce the amplitude of the molecular torsional motion, make the bond breakage caused by the molecular torsional motion relatively less, and improve the stability of the guest material RD.

[0374] For Examples 4 to 6 and Comparative Example 2, please refer to Table 6. The half-peak widths of the emission spectra of Examples 4 to 6 are relatively narrow. 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, the molecular deformation in the excited state is relatively small, and the corresponding triplet split energy levels are relatively small, so that when the guest material RD emits light using triplet excitons, the corresponding wavelength band is relatively narrow, and the peak of the emission spectrum of the light-emitting layer 130 is relatively narrow.

[0375] It can be seen from the above embodiments and comparative examples that the present disclosure can make the molecular rigidity of the guest material D relatively high by setting the guest material D of the light-emitting layer 130 as a tetradentate ligand material, 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 can reduce the amplitude of the molecular torsional motion by setting the guest material D of the light-emitting layer 130 as a tetradentate ligand material, 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 can set the guest material D of the light-emitting layer 130 as a tetradentate ligand material, so that the deformation of the molecule in the excited state is relatively small, and the corresponding triplet split energy level is relatively small, so that 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.

[0376] The above is only a specific embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any changes or substitutions that can be thought of by any person skilled in the art within the technical scope disclosed in the present disclosure should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A light-emitting substrate, characterized in that: include: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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 claim 1, characterized in that: 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 claim 1, characterized in that: 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 claim 2, characterized in that: 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, characterized in that: 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 8, characterized in that: 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 claim 7, characterized in that: 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, characterized in that: 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 claim 10 or 11, characterized in that: 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 claim 7, characterized in that: 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 7, characterized in that: 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 claim 13 or 14, characterized in that: 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 claim 7, characterized in that: 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 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 dibenzothienyl and substituted or unsubstituted carbazolyl; 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 claim 7, characterized in that: 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 claim 16 or 17, characterized in that: 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 11, 13 to 14, and 16 to 17, characterized in that: 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, 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 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 claim 7, characterized in that: 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, characterized in that: comprising the light-emitting substrate according to any one of claims 1 to 20; It 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, characterized in that: comprising the display panel as claimed in claim 21; It also includes: a driving chip, and the driving chip is used to drive the display panel to display.

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