Display substrate and display device

Abstract

The display substrate includes a backplane, an anode layer, a first auxiliary layer, a first light-emitting layer, a second auxiliary layer, a plurality of second light-emitting layers of at least two different colors, a third auxiliary layer, and a cathode layer. The first auxiliary layer includes a film layers stacked in sequence, and the optical thickness of the a film layers is L1, and L1 satisfies the following formula. 【Equation 1】 TIFF2025522942000052.tif1525 The second auxiliary layer includes b film layers stacked in sequence, and the optical thickness of the b film layers is L2, and L2 satisfies the following formula. 【Equation 2】 TIFF2025522942000053.tif1725 The third auxiliary layer includes c film layers stacked in sequence, and the optical thickness of the c film layers is L3, and L3 satisfies the following formula. 【Equation 3】 TIFF2025522942000054.tif1828 L1, L2, and L3 satisfy the following formula. 【Equation 4】 TIFF2025522942000055.tif1583

Description

[Technical Field]

[0001] This application claims priority from a Chinese patent application bearing application number 202210798416.7, filed on July 8, 2022, the entire contents of which are incorporated herein by reference.

[0002] The present disclosure relates to the field of display technology, and more particularly to a display substrate and a display device. [Background technology]

[0003] OLED (Organic Light Emitting Diode) display devices are displays made of organic electroluminescent diodes. OLED display devices are currently widely used due to their excellent properties, such as no need for backlight, high contrast, thinness, wide viewing angle, fast response speed, usability in flexible panels, wide operating temperature range, and relatively simple structure and process. Summary of the Invention

[0004] An embodiment of the present invention is ,table The present invention aims to provide a display substrate and a display device.

[0005] In one embodiment, a display substrate is provided. The display substrate includes a backplane and an anode layer, a first auxiliary layer, a first light-emitting layer, a second auxiliary layer, a plurality of second light-emitting layers of at least two different colors, a third auxiliary layer, and a cathode layer, which are sequentially stacked on the backplane. A microcavity is formed between the anode layer and the cathode layer. The first light-emitting layer is disposed between the first auxiliary layer and the second auxiliary layer. The plurality of second light-emitting layers are disposed between the second auxiliary layer and the third auxiliary layer. Here, the first auxiliary layer includes a number of film layers sequentially stacked, and the a number of film layers have an optical thickness L1, where L1 is

number

[0006] The second auxiliary layer includes b film layers stacked in sequence, and the b film layers have an optical thickness of L2, where L2 is:

number

[0007] The third auxiliary layer includes c film layers stacked in sequence, and the c film layers have an optical thickness L3, where L3 is:

number

[0008] L 1, L2, and L3 satisfy the following formula.

number

[0009] In some embodiments, the plurality of second light-emitting layers include a plurality of second blue light-emitting layers, a plurality of second red light-emitting layers, and a plurality of second green light-emitting layers, and the wavelength of light emitted by the first light-emitting layers is shorter than the wavelength of light emitted by at least one of the second light-emitting layers.

[0010] In some embodiments, the first light-emitting layer comprises a first guest material; In the second light-emitting layer of at least one colorThe second light-emitting layer includes a second guest material, the emission spectrum of which at least partially overlaps with the absorption spectrum of the second guest material of the second light-emitting layer of at least one color.

[0011] In some embodiments, the overlap range between the emission spectrum of the first guest material and the absorption spectrum of the second guest material is 60% or more of the wavelength range of the emission spectrum of the first guest material.

[0012] In some embodiments, the overlap range between the emission spectrum of the first guest material and the absorption spectrum of the second guest material is 60% or more of the wavelength range of the absorption spectrum of the second guest material.

[0013] In some embodiments, the emission spectrum of the first guest material has a peak value below 600 nm.

[0014] In some embodiments, the first guest material comprises at least one luminescent material. When the first guest material comprises two luminescent materials, the separation between the peak values ​​of the emission spectra of the two luminescent materials is 30 nm or less.

[0015] In some embodiments, the first guest material has an emission spectrum with a peak value ranging from 465 nm to 475 nm, and the second guest material of the second green light-emitting layer has an absorption spectrum with a peak value ranging from 507 nm to 517 nm.

[0016] In some embodiments, the emission spectrum of the first guest material has a peak value in the range of 525 nm to 535 nm, the absorption spectrum of the second guest material of the second green light-emitting layer has a peak value in the range of 510 nm to 520 nm, and the absorption spectrum of the second guest material of the second red light-emitting layer has a peak value in the range of 595 nm to 605 nm.

[0017] In some embodiments, the first guest material includes at least one luminescent material. When the first guest material includes two luminescent materials, at least one of the two luminescent materials is doped with boron, and the doping ratio of the boron is in the range of 0.5% to 5%.

[0018] In some embodiments, the second guest material of the second emissive layer of at least one color comprises at least one luminescent material, and when the second guest material comprises two luminescent materials, the separation between the peak values ​​of the emission spectra of the two luminescent materials is 30 nm or less.

[0019] In some embodiments, the second guest material of the second light-emitting layer of at least one color comprises at least one light-emitting material, and when the second guest material comprises two light-emitting materials, at least one of the two light-emitting materials is doped with boron, and the doping ratio of the boron is in the range of 0.5% to 5%.

[0020] In some embodiments, the first guest material comprises at least one of a fluorescent material, a phosphorescent material, and a thermally activated delayed fluorescent material, and / or the second guest material comprises at least one of a fluorescent material, a phosphorescent material, or a thermally activated delayed fluorescent material with multiple resonance properties.

[0021] In some embodiments, the first light-emitting layer further comprises a first host material, and the first host material comprises a single host material or a PN mixed host material.

[0022] In some embodiments, the material of the second light-emitting layer of at least one color further comprises a second host material, and the second host material comprises a bipolar host material.

[0023] In some embodiments, the second host material comprises a single host material or a PN mixed host material. When the second host material is a PN mixed host material, in PN mixed host materials N-type materials have thermally activated delayed fluorescence properties.

[0024] In some embodiments, the microcavity comprises a plurality of sub-microcavities, the plurality of sub-microcavities comprising: In the plurality of second red light-emitting layers a red sub-microcavity corresponding to the second red light-emitting layer; and In the plurality of second green light-emitting layers a green sub-microcavity corresponding to the second green light-emitting layer; and In the plurality of second blue light-emitting layers and a blue sub-microcavity corresponding to the second blue light-emitting layer. The number of film layers corresponding to the sub-microcavities of any one color located between the anode layer and the cathode layer is d, and the optical thickness of the d film layers is L, where L satisfies the following formula:

number

[0025] In the formula, d is a positive integer, n m is the refractive index of the mth film layer among the d film layers, and r m is the thickness of the mth film layer, k is a natural number, λ is the target spectral peak wavelength, and φ is the phase shift caused by the target light after it is reflected by the anode layer.

[0026] In some embodiments, the length of the blue sub-microcavity is smaller than the length of the red sub-microcavity, and the length of the blue sub-microcavity is smaller than the length of the green sub-microcavity.

[0027] In some embodiments, the thickness of the first light-emitting layer is in the range of 15 nm to 60 nm; and / or In a plurality of second light-emitting layers of at least two different colors The thickness of the second light-emitting layer ranges from 10 nm to 50 nm.

[0028] In some embodiments, the first auxiliary layer includes a light-transmitting conductive layer, a hole injection layer, a first hole transport layer, and an electron blocking layer; and / or the second auxiliary layer includes a first hole blocking layer, a first electron transport layer, a first charge generation layer, a second charge generation layer, and a microcavity adjustment layer; and / or the third auxiliary layer includes a second hole blocking layer, a second electron transport layer, and an electron injection layer.

[0029] In some embodiments, the microcavity adjusting layer comprises a second hole transport layer and a second hole transport layer. In the plurality of second red light-emitting layers a red sub-microcavity adjusting layer provided between the second red light-emitting layer and the second hole transport layer; In the plurality of second green light-emitting layers a green sub-microcavity adjusting layer provided between the second green light-emitting layer and the second hole transport layer; In the plurality of second blue light-emitting layers and a blue sub-microcavity adjusting layer disposed between the red sub-microcavity adjusting layer and the second blue light-emitting layer, wherein the red sub-microcavity adjusting layer and the blue sub-microcavity adjusting layer have different lengths, and the green sub-microcavity adjusting layer and the blue sub-microcavity adjusting layer have different lengths.

[0030] In some embodiments, the red sub-microcavity adjusting layer includes a red hole transport layer and a red electron blocking layer stacked in sequence away from the backplate, and the green sub-microcavity adjusting layer includes a green hole transport layer and a green electron blocking layer stacked in sequence away from the backplate, where the red hole transport layer and the green hole transport layer are used to adjust the length of the sub-microcavity of the corresponding color, respectively.

[0031] In some embodiments, the light-transmitting conductive layer has a thickness of 10 nm or less, and / or the hole injection layer has a thickness of 10 nm or less, and / or the electron blocking layer has a thickness of 10 nm or less, and / or the first hole blocking layer has a thickness of 10 nm or less, and / or the first electron transport layer has a thickness ranging from 15 nm to 50 nm, and / or the first charge generation layer has a thickness of 10 nm or less, and / or the second charge generation layer has a thickness of 10 nm or less, and / or the second hole blocking layer has a thickness of 10 nm or less, and / or the second electron transport layer has a thickness ranging from 15 nm to 50 nm.

[0032] In some embodiments, the number of the first light-emitting layers is plural, and the second auxiliary layer is provided between any two adjacent first light-emitting layers; and / or At least two different colors Multiple second light-emitting layers The second light-emitting layer in are located in the same layer to form one light-emitting layer group, the number of the light-emitting layer groups is plural, and the third auxiliary layer is provided between any two adjacent light-emitting layer groups.

[0033] In another aspect, a display substrate is provided. The display substrate includes a backplane and an anode layer, a first auxiliary layer, a first light-emitting layer, a second auxiliary layer, a plurality of second light-emitting layers of at least two different colors, a third auxiliary layer, and a cathode layer, which are sequentially stacked on the backplane. A microcavity is formed between the anode layer and the cathode layer. The first light-emitting layer is disposed between the first auxiliary layer and the second auxiliary layer. The plurality of second light-emitting layers are disposed between the second auxiliary layer and the third auxiliary layer. Here, the first auxiliary layer includes a number of film layers stacked in sequence, the second auxiliary layer includes a number of film layers stacked in sequence, and the third auxiliary layer includes a number of film layers stacked in sequence, where a, b, and c are all positive integers. The optical thicknesses of the a film layer, the b film layer, and the c film layer satisfy the following formula:

number

[0034]

number

number

[0035] In yet another aspect, a display substrate is provided. The display substrate includes a backplane and an anode layer, a first auxiliary layer, a first light-emitting layer, a second auxiliary layer, a plurality of second light-emitting layers of at least two different colors, a third auxiliary layer, and a cathode layer, which are sequentially stacked on the backplane. The second auxiliary layer includes a charge generating layer, and a microcavity is formed between the anode layer and the cathode layer. The first light-emitting layer is capable of emitting light of at least two different colors. The plurality of second light-emitting layers includes a plurality of second blue light-emitting layers, a plurality of second red light-emitting layers, and a plurality of second green light-emitting layers. Here, the first auxiliary layer includes a number of film layers stacked in sequence, the second auxiliary layer includes a number of film layers stacked in sequence, and the third auxiliary layer includes a number of film layers stacked in sequence, where a, b, and c are all positive integers. The optical thicknesses of the a film layer, the b film layer, and the c film layer satisfy the following formula:

number

[0036]

number

number

[0037] In yet another aspect, there is provided a display device, the display device comprising the display substrate according to any one of the embodiments of the above aspect, the display device comprising the display substrate according to the embodiment of another aspect, or the display device comprising the display substrate according to the embodiment of yet another aspect.

[0038] The display device may have the same display substrate as that provided in some of the above embodiments. Jiyu This has beneficial technical effects, and the description thereof will be omitted here. [Brief explanation of the drawings]

[0039] In order to more clearly explain the technical solutions in the present disclosure, the following will briefly explain the drawings required for describing some embodiments of the present disclosure. The drawings in the following description are merely drawings of some embodiments of the present disclosure, and it is obvious to those skilled in the art that other drawings can be obtained based on these drawings. Furthermore, the drawings in the following description can be regarded as schematic diagrams, and do not limit the actual dimensions of the products, the actual processes of the methods, the actual sequences of the signals, etc., according to the embodiments of the present disclosure.

[0040] [Figure 1] 1 is a structural diagram of a display device according to some embodiments of the present disclosure.

[0041] [Figure 2] 1A and 1B are structural diagrams of a display substrate according to some embodiments of the present disclosure.

[0042] [Figure 3]FIG. 10 is a structural diagram of another display substrate according to some embodiments of the present disclosure.

[0043] [Figure 4] FIG. 1 is a structural diagram of a display substrate in a first method.

[0044] [Figure 5] FIG. 10 is a structural diagram of a display substrate in the second method.

[0045] [Figure 6] FIG. 10 is a structural diagram of yet another display substrate according to some embodiments of the present disclosure.

[0046] [Figure 7] FIG. 10 is a structural diagram of yet another display substrate according to some embodiments of the present disclosure.

[0047] [Figure 8] FIG. 10 is a structural diagram of yet another display substrate according to some embodiments of the present disclosure.

[0048] [Figure 9] FIG. 10 is a structural diagram of yet another display substrate according to some embodiments of the present disclosure.

[0049] [Figure 10] 10 is a spectrogram of a part of a light-emitting layer in Verification Example 1.

[0050] [Figure 11] 10 is a spectrogram of a part of the light-emitting layer in Verification Example 2.

[0051] [Figure 12] FIG. 10 is a structural diagram of yet another display substrate according to some embodiments of the present disclosure.

[0052] [Figure 13] FIG. 10 is a structural diagram of yet another display substrate according to some embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0053] The following clearly and completely describes the technical solutions of some embodiments of the present disclosure with reference to the drawings, but it is clear that the described embodiments are only a part of the embodiments of the present disclosure and do not represent all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments provided by the present disclosure fall within the scope of protection of the present disclosure.

[0054] In this specification and claims, the term "comprise" and other forms thereof, such as the third-person singular "comprises" and the present participle form "comprising," should be construed in an open, inclusive sense, i.e., "including but not limited to," unless the context otherwise requires. In the description herein, the terms "one embodiment," "some embodiments," "exemplary embodiments," "example," "specific example," or "some examples" are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of the present disclosure. General references to the above terms do not necessarily refer to the same embodiment or example. Furthermore, a described particular feature, structure, material, or characteristic may be included in any one or more embodiments or examples in any appropriate manner.

[0055] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and cannot be understood to express or imply relative importance or the number of technical features presented. Thus, a feature qualified by "first" or "second" may explicitly or implicitly include one or more of that feature. In describing the embodiments of the present disclosure, unless otherwise specified, "plurality" means two or more than two.

[0056] When describing some embodiments, the term "connected" and expressions derived therefrom may be used. For example, when describing some embodiments, the term "connected" may be used to indicate that two or more components are in direct physical or electrical contact with each other. The embodiments disclosed herein are not necessarily limited to the contents of this specification.

[0057] "At least one of A, B, and C" has the same meaning as "at least one of A, B, or C," and all include combinations of A, B, and C with A only, B only, C only, a combination of A and B, a combination of A and C, a combination of B and C, and a combination of A, B, and C.

[0058] "A and / or B" includes three combinations: A only, B only, and a combination of A and B.

[0059] The use of "disposed to" herein is intended to be open and inclusive language and does not exclude devices adapted or arranged to perform additional tasks or steps.

[0060] Also, the use of "based on" is meant to be open-ended and inclusive, as a process, step, calculation, or other action performed "based on" one or more stated conditions or values ​​may, in fact, be based on additional conditions or exceed the stated values.

[0061] As used herein, "about" includes the stated value and the mean within an acceptable range of deviation of the specified value, where the acceptable range of deviation is determined by one of ordinary skill in the art considering the measurement and the error associated with measuring the specified quantity (i.e., limitations of the measurement system).

[0062] When a layer or element is referred to as being on another layer or substrate, it is understood that the layer or element may be located directly on the other layer or substrate, or there may be intermediate layers between the layer or element and the other layer or substrate.

[0063] Exemplary embodiments are described herein with reference to cross-sectional and / or plan views that are idealized illustrative drawings. In the drawings, thicknesses of layers and regions are exaggerated for clarity. Accordingly, variations in shape relative to the drawings due, for example, to manufacturing techniques and / or tolerances, can be expected. Thus, the exemplary embodiments are not limited to the shapes of regions illustrated herein, but should be construed to include deviations in shape due to manufacturing or otherwise. For example, an etching region shown as a rectangle typically has curved features. Thus, the regions shown in the drawings are exemplary in nature, and their shapes are not intended to represent the actual shape of the regions of the facility, nor are they intended to limit the scope of the exemplary embodiments.

[0064] Some embodiments of the present invention provide a display substrate and a display device. Hereinafter, a display substrate 100 and a display device 1000 will be described in conjunction with the drawings.

[0065] As shown in FIG. 1 , some embodiments of the present disclosure provide a display substrate 1000. The display device 1000 can be any device that displays text or images, whether moving (e.g., video) or fixed (e.g., still images). More specifically, it is anticipated that the described embodiments may be implemented in or associated with a variety of electronic devices, including, 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, car displays (e.g., odometer displays, etc.), navigation, cockpit controllers and / or displays, camera view displays (e.g., rearview camera displays in vehicles), electronic photography, electronic signage or signs, projectors, architectural structures, packaging, and aesthetic structures (e.g., displays for jewelry images).

[0066] In some examples, the display device 1000 includes a frame, a display substrate 100 provided in the frame, a circuit board, a data driver IC (Integrated Circuit), and other electronic components.

[0067] The display substrate 100 may be, for example, an organic light emitting diode (OLED). (Organic Light Emitting Diode, abbreviated as OLED) The display substrate may be a quantum dot light emitting diode (QLED) display substrate, a micro light emitting diode (Micro LED) display substrate, or a mini light emitting diode (Mini LED) display substrate, but the present disclosure is not particularly limited thereto.

[0068] Hereinafter, several embodiments of the present disclosure will be described schematically, taking the substrate 100 as an OLED display substrate as an example.

[0069] In some embodiments, the display substrate 100 includes a backplane 1, as shown in FIG.

[0070] In some examples, the backplane 1 includes a substrate 11 and a plurality of pixel driving circuits 12 disposed on the substrate 11 .

[0071] The substrate 11 may be of various types, and may be selected and installed according to actual needs.

[0072] Illustratively, the substrate 11 may be a rigid substrate, and the material of the rigid substrate may include, for example, glass, quartz, or plastic.

[0073] Exemplarily, the substrate 11 may be a flexible substrate, and the material of the flexible substrate may include, for example, PET (Polyethylene terephthalate), PEN (Polyethylene naphthalate two formic acid glycol ester), or PI (Polyimide).

[0074] In some examples, the plurality of pixel driving circuits 12 are arranged, for example, in an array.

[0075] The pixel driving circuit 12 may have various structures, which can be selected and configured according to actual needs. For example, the pixel driving circuit 12 may have a structure such as "3T1C", "4T1C", "6T1C", "7T1C", "6T2C", "7T2C", or "8T2C", where "T" represents a transistor, the number before "T" represents the number of transistors, and "C" represents a storage capacitor, and the number before "C" represents the number of storage capacitors.

[0076] Illustratively, the pixel driving circuit 12 is represented by one transistor 121 in FIG.

[0077] In some embodiments, the display substrate 100 further includes a light emitting element layer 2, as shown in FIG.

[0078] In some examples, as shown in Fig. 3, the light-emitting element layer 2 includes a plurality of light-emitting elements 2a, which are arranged, for example, in an array, as shown in Fig. 2. Here, the light-emitting elements 2a are, for example, OLEDs.

[0079] The pixel driving circuit 12 and the light emitting element 2a are electrically connected. Here, the electrical connection relationship between them includes various types, and specifically, it can be selected and installed according to actual needs, and the present disclosure is not limited thereto.

[0080] For example, the pixel driving circuits 12 and the light-emitting elements 2a may be electrically connected in one-to-one correspondence. Also, for example, one pixel driving circuit 12 may be electrically connected to multiple light-emitting elements 2a. Furthermore, for example, multiple pixel driving circuits 12 may be electrically connected to one light-emitting element 2a.

[0081] The structure of the display substrate 100 will be described below in a schematic manner, taking as an example a case where the pixel driving circuits 12 and the light emitting elements 2a are electrically connectable in one-to-one correspondence.

[0082] It is understood that the pixel driving circuit 12 generates a driving signal and transmits the driving signal to the corresponding light-emitting element 2a to control the light-emitting state of the light-emitting element 2a. The light-emitting state includes, for example, whether the light-emitting element 2a is emitting light or not, and the light-emitting brightness of the light-emitting element 2a. A plurality of pixel driving circuits 12 commonly control the light-emitting states of the plurality of light-emitting elements 2a, thereby realizing a screen display on the display substrate 100.

[0083] Here, each pixel driving circuit 12 and the light emitting element 2a electrically connected thereto can be called a sub-pixel.

[0084] There are two main ways for a display substrate to achieve full color display. For example, one way is to provide a full color display solution by using R / G / B individual light emitting units, and the other way is to achieve full color by using color conversion or color filtering. display It is to provide solutions.

[0085] In one embodiment, providing a full-color display solution using R / G / B individual light-emitting units means that the light-emitting element mainly includes an anode, a light-emitting layer, and a cathode, which are stacked sequentially away from the substrate. Here, the light-emitting layer may be a red light-emitting layer, a green light-emitting layer, or a blue light-emitting layer, and the light-emitting element may be a red light-emitting element, a green light-emitting element, or a blue light-emitting element, respectively. The red light-emitting element can emit red light under the control of a corresponding pixel driving circuit, the green light-emitting element can emit green light under the control of a corresponding pixel driving circuit, and the blue light-emitting element can emit blue light under the control of a corresponding pixel driving circuit. A full-color display can be achieved by operating multiple light-emitting elements in conjunction with each other. However, this solution results in relatively low light-emitting efficiency and light-emitting brightness of the light-emitting elements.

[0086] In another embodiment, full color is obtained by color conversion or color filtering. display There are two main ways to provide solutions.

[0087] As shown in FIG. 4, in the first type, the light-emitting element 2a' is a series-connected bottom-emission light-emitting element, and the light-emitting element is used to emit white light. The display substrate further includes a color filter CF disposed on the side of the substrate 11' away from the light-emitting element 2a'. After passing through the color filter CF, the white light emitted by the light-emitting element 2a' is converted into red, green, or blue light, thereby achieving a full-color display. However, due to its structure, it is relatively difficult to improve the brightness at a front viewing angle with a bottom-emission light-emitting element. Furthermore, using a top-emission light-emitting element increases the process complexity and also causes problems such as excessive light loss in certain wavelength bands.

[0088] As shown in FIG. 5, in the second type, the light-emitting element 2a' is a serial top-emission light-emitting element, and is used to emit blue light. The display substrate further includes a red quantum dot conversion layer R-CC and a green quantum dot conversion layer G-CC disposed on the side of the light-emitting element 2a' away from the substrate 11'. Blue light passing through the red quantum dot conversion layer R-CC is converted into red light, and blue light passing through the green quantum dot conversion layer G-CC is converted into green light. This achieves full-color display. However, due to the influence of the light conversion efficiency of the red quantum dot conversion layer R-CC and the green quantum dot conversion layer G-CC themselves, the color purity of the converted red and green light is relatively low. Therefore, corresponding filters must be added. For example, a red filter R-CF may be provided on the side of the red quantum dot conversion layer R-CC away from the substrate 11', and a green filter G-CF may be provided on the side of the green quantum dot conversion layer G-CC away from the substrate 11' to improve color purity. In this way, the process complexity of the display substrate increases, and the power consumption of the display substrate increases.

[0089] Based on this, as shown in FIG. 3 , in some embodiments of the present disclosure, the light-emitting element layer 2 includes an anode layer 21, a first auxiliary layer 22, a first light-emitting layer 23, a second auxiliary layer 24, a plurality of second light-emitting layers 25, a third auxiliary layer 26, and a cathode layer 27 provided on a backplate 1.

[0090] 3, the anode layer 21 includes a plurality of anodes 211, which are arranged, for example, in an array, where each anode 211 corresponds to a light-emitting element 2a, and each light-emitting element 2a is electrically connected to a corresponding pixel driving circuit 12 via the anode 211. The anode 211 receives a driving signal from the corresponding pixel driving circuit 12, and can cooperate with the corresponding pixel driving circuit 12 to individually control the light-emitting element 2a.

[0091] Illustratively, the material of the anode layer 21 includes a conductive material having a relatively high work function. The structure of the anode layer 21 may be, for example, a single-layer structure, or may be, for example, a structure in which multiple film layers are sequentially stacked.

[0092] For example, when the anode layer 21 has a single-layer structure, the single-layer structure has a relatively good light reflection performance and can reflect light emitted to the anode layer 21 .

[0093] For example, when the anode layer 21 has a structure in which multiple film layers are sequentially stacked, the film layers of the multiple film layers that are farther from the backplate 1 have relatively good light reflectivity and can reflect light radiated to the anode layer 21. The material of the film layers with relatively good light reflectivity may include, for example, at least one of Al (aluminum), Ag (silver), and Mg (magnesium). The film layers of the multiple film layers that are closer to the backplate 1 may have relatively good light transmittance, for example, and the material of the film layers with relatively good light transmittance may include, for example, ITO (indium tin oxide), IZO (indium zinc oxide), etc.

[0094] For example, a method for forming the anode 211 includes forming (e.g., using a sputtering process) a conductive thin film (the conductive thin film has a single layer structure or a structure in which multiple thin films are sequentially stacked) on the backplane 1, and then patterning the conductive film (e.g., etching the conductive thin film using a photolithography process) to obtain multiple anodes 211 that are independent of each other.

[0095] The display substrate 100 may further include a pixel definition layer disposed on the side of the anode layer 21 remote from the substrate 11. The pixel definition layer has a plurality of openings, which are arranged in one-to-one correspondence with the anodes 211, and each opening exposes a portion of the corresponding anode 211 to facilitate contact between the anode 211 and the film layer located on the side remote from the substrate 11, thereby forming an electrical connection.

[0096] 3, the first auxiliary layer 22 is provided on the side of the anode layer 21 away from the substrate 11. Optionally, the first auxiliary layer 22 is located on the side of the pixel definition layer away from the substrate 11.

[0097] Exemplarily, the first auxiliary layer 22 can contact the anode 211 through an opening in the pixel definition layer to form an electrical connection.

[0098] Illustratively, the first auxiliary layer 22 includes a number a of film layers stacked in sequence, where a is a positive integer. For example, the number of film layers included in the first auxiliary layer 22 may be 1, 2, 3, or 4.

[0099] Optionally, when the first auxiliary layer 22 includes one film layer, the first auxiliary layer 22 covers the anode layer 21. That is, different light-emitting elements 2a share the first auxiliary layer 22.

[0100] Optionally, when the first auxiliary layer 22 comprises at least two film layers: In at least two film layersAt least one film layer covers the anode layer 21. That is, different light-emitting elements 2a share the at least one film layer.

[0101] Illustratively, the present disclosure Example of A deposition process can be used to form the first auxiliary layer 22 .

[0102] By sharing the film layer of the first auxiliary layer 22 among different light-emitting elements 2a, patterning of the first auxiliary layer 22 can be avoided, which is advantageous in simplifying the manufacturing process of the first auxiliary layer 22 and the display substrate 100.

[0103] In some examples, as shown in FIG. 3, the first light-emitting layer 23 is provided on the side of the first auxiliary layer 22 away from the substrate 11.

[0104] Illustratively, the first light-emitting layer 23 is disposed over the entire layer, and different light-emitting elements 2 a share the first light-emitting layer 23 .

[0105] The first auxiliary layer 22 is located between the anode layer 21 and the first light-emitting layer 23, and is mainly used to increase the hole transition rate, reduce the hole injection barrier, increase the amount of holes transitioning to the first light-emitting layer 23, increase the recombination rate between holes and electrons transitioning to the first light-emitting layer 23, and improve the luminous efficiency of the first light-emitting layer 23.

[0106] In some examples, as shown in FIG. 3, the second auxiliary layer 24 is provided on the side of the first light-emitting layer 23 away from the substrate 11. Record number The first light-emitting layer 23 is disposed between the first auxiliary layer 22 and the second auxiliary layer 24. Here, the second auxiliary layer 24 contacts the first light-emitting layer 23 to form an electrical connection.

[0107] Illustratively, the second auxiliary layer 24 includes b film layers stacked in sequence, where b is a positive integer. For example, the number of film layers included in the second auxiliary layer 24 may be 1, 2, 3, or 4.

[0108] Illustratively, different light-emitting elements 2 a share the second auxiliary layer 24 .

[0109] Illustratively, the present disclosure Example of A deposition process can be used to form the second auxiliary layer 24 .

[0110] By sharing the film layer of the second auxiliary layer 24 among different light-emitting elements 2a, patterning of the second auxiliary layer 24 can be avoided, which is advantageous in simplifying the manufacturing process of the second auxiliary layer 24 and the display substrate 100.

[0111] In some examples, as shown in Figure 3, the plurality of second light-emitting layers 25 are disposed on the side of the second auxiliary layer 24 away from the substrate 11. For example, the plurality of second light-emitting layers 25 are located in the same layer, and each second light-emitting layer 25 contacts the second auxiliary layer 24 to form an electrical connection. In the plurality of second light-emitting layers 25 At least two second light-emitting layers 25 may be stacked. Example of Here, an example in which the plurality of second light-emitting layers 25 are located in the same layer will be described.

[0112] Illustratively, the plurality of second light-emitting layers 25 have at least two different colors.

[0113] For example, the plurality of second light-emitting layers 25 have two different colors. Optionally, the plurality of second light-emitting layers 25 includes a plurality of second blue light-emitting layers 25B and a plurality of second red light-emitting layers 25R. Alternatively, the plurality of second light-emitting layers 25 includes a plurality of second blue light-emitting layers 25B and a plurality of second green light-emitting layers 25G. Alternatively, the plurality of second light-emitting layers 25 includes a plurality of second red light-emitting layers 25R and a plurality of second green light-emitting layers 25G.

[0114] For example, the second light-emitting layers 25 have three different colors. Optionally, the second light-emitting layers 25 include a plurality of second blue light-emitting layers 25B, a plurality of second red light-emitting layers 25R, and a plurality of second green light-emitting layers 25G.

[0115] The plurality of second light-emitting layers 25 at least Since the second light-emitting layers 25 have two different colors, they need to be formed by different manufacturing processes, where the second light-emitting layers 25 of one color can correspond to one process. For example, the second light-emitting layers 25 can be formed by a deposition process, where the second light-emitting layers 25 of one color can be deposited in one process, and then the second light-emitting layers 25 of the other color can be deposited in another process.

[0116] The second auxiliary layer 24 is , th Located between the first light-emitting layer 23 and the plurality of second light-emitting layers 25, the second auxiliary layer 24 is mainly used to connect the first light-emitting layer 23 and the second light-emitting layer 25 in series to form a series-type light-emitting element.

[0117] 3, the third auxiliary layer 26 is provided on the side of the second light-emitting layers 25 that is farther from the substrate 11. That is, the second light-emitting layers 25 are provided between the second auxiliary layer 24 and the third auxiliary layer 26. Here, the third auxiliary layer 26 contacts each second light-emitting layer 25 to form an electrical connection.

[0118] Illustratively, the third auxiliary layer 26 includes c film layers stacked in sequence, where c is a positive integer. For example, the number of film layers included in the third auxiliary layer 26 may be 1, 2, or 3.

[0119] Optionally, the different light-emitting devices 2 a share the third auxiliary layer 26 .

[0120] Illustratively, the present disclosure Example of A deposition process can be used to form the third auxiliary layer 26 .

[0121] By sharing the third auxiliary layer 26 among different light-emitting elements 2a, patterning of the third auxiliary layer 26 can be avoided, which is advantageous in simplifying the manufacturing process of the third auxiliary layer 26 and the display substrate 100.

[0122] In some examples, as shown in FIG. 3, the cathode layer 27 is disposed on the side of the third auxiliary layer 26 away from the substrate 11 and contacts the third auxiliary layer 26 to form an electrical connection.

[0123] Illustratively, different light-emitting elements 2a share the cathode layer 27. That is, the cathode layer 27 is a whole-layer structure.

[0124] Illustratively, the present disclosure Example of A vapor deposition process can be used to form the cathode layer 27 .

[0125] By sharing the cathode layer 27 among different light emitting elements 2 a , patterning of the cathode layer 27 can be avoided, which is advantageous in simplifying the manufacturing process of the cathode layer 27 and the display substrate 100 .

[0126] The third auxiliary layer 26 is located between the plurality of second light-emitting layers 25 and the cathode layer 27. The third auxiliary layer 26 mainly serves to increase the electron transition rate, Second light-emitting layer 25 Transition to electronic Increase the amount of holes and Second light-emitting layer 25 and increasing the recombination rate with electrons transitioning to the second light-emitting layer 25, thereby preventing holes or excitons formed by the recombination of holes and electrons from leaking from the second light-emitting layer 25. Second light-emitting layer 25 It is used to improve the luminous efficiency of

[0127] In some examples, the anode layer 21 has a relatively high reflectivity, and the cathode layer 27 is a film layer with semi-transmissive and semi-reflective properties. Here, "semi-transmissive and semi-reflective" means that the cathode layer 27 can transmit and reflect light, and the specific transmittance and reflectance are not limited. The light-emitting element 2a in the embodiments of the present disclosure is a top-emission light-emitting element.

[0128] Illustratively, the reflectance of the anode layer 21 is 80% or more.

[0129] For example, the thickness of the cathode layer 27 is in the range of 10 nm to 20 nm, which ensures the conductive properties of the cathode layer 27 and improves the light transmittance of the cathode layer 27, thereby improving the luminous efficiency of the display substrate 100.

[0130] For example, the thickness of the cathode layer 27 may be 10 nm, 12 nm, 14 nm, 17 nm, 20 nm, or the like.

[0131] For example, the transmittance of the cathode layer 27 for light with a wavelength of 530 nm ranges from 45% to 60%.

[0132] For example, the transmittance may be 45%, 50%, 53%, 57%, or 60%.

[0133] 6, it can be seen that a microcavity A can be formed between the anode layer 21 and the cathode layer 27 based on the characteristics of the anode layer 21 and the cathode layer 27. As a result, light emitted from the first light-emitting layer 23 and the second light-emitting layer 25 can be reflected, interfered, etc. within the microcavity A, resulting in a microcavity effect, which improves the luminance of the emitted light, narrows the spectrum of the emitted light, and improves the luminous efficiency of the light-emitting element 2a. For example, the luminance of blue light can be improved and the spectrum of blue light can be narrowed.

[0134] In some examples, the optical thickness of the a film layers included in the first auxiliary layer 22 is L1, and L1 satisfies the following formula:

number

[0135] In the formula, n h is the refractive index of the h-th film layer among the a film layers, r h is the thickness of the h-th film layer.

[0136] The optical thickness of the b film layers included in the second auxiliary layer 24 is L2, and L2 satisfies the following formula:

number

[0137] In the formula, n i is the refractive index of the i-th film layer among the b film layers, r i is the thickness of the ith film layer.

[0138] The optical thickness of the c film layers included in the third auxiliary layer 26 is L3, and L3 satisfies the following formula:

number

[0139] n j is the refractive index of the j-th film layer among the c film layers, and r j is the thickness of the jth film layer.

[0140] L1, L2, and L3 satisfy the following formula.

number

[0141] For example,

number

[0142] The above-described arrangement can improve the color purity of the light emitted by the light-emitting element 2a on the display substrate 100. In the examples The display substrate 100 can reduce the number of filters installed, thereby reducing the blocking of light emitted by the light emitting element 2a by the filters. In the examples The luminous efficiency of the display substrate 100 is improved. Example ofThis can reduce the driving voltage of the pixel driving circuit 12 in the display substrate 100 while achieving brightness similar to that of the first and second embodiments described above, thereby reducing the power consumption of the display substrate 100 and improving the light-emitting life of the light-emitting element 2a.

[0143] The refractive index range of the h-th film layer, the i-th film layer, and the j-th film layer with respect to light with a wavelength of 460 nm is all 1.7 to 2.0.

[0144] For example, the refractive indexes of the h-th film layer, the i-th film layer, and the j-th film layer with respect to light having a wavelength of 460 nm may be the same or different.

[0145] For example, the refractive indices of the h-th film layer, the i-th film layer, and the j-th film layer with respect to light with a wavelength of 460 nm are 1.7, 1.75, 1.8, 1.9, and 2.0.

[0146] 3, the plurality of second light-emitting layers 25 includes a plurality of second blue light-emitting layers 25B, a plurality of second red light-emitting layers 25R, and a plurality of second green light-emitting layers 25G. The wavelength of light emitted by the first light-emitting layer 23 is shorter than the wavelength of light emitted by at least one of the second light-emitting layers 25.

[0147] Illustratively, the wavelength of light emitted by first light-emitting layer 23 is shorter than the wavelength of light emitted by second blue light-emitting layer 25B, or the wavelength of light emitted by first light-emitting layer 23 is shorter than the wavelength of light emitted by second red light-emitting layer 25R, or the wavelength of light emitted by first light-emitting layer 23 is shorter than the wavelength of light emitted by second green light-emitting layer 25G. Alternatively, the wavelength of light emitted by first light-emitting layer 23 is shorter than the wavelength of light emitted by second red light-emitting layer 25R and shorter than the wavelength of light emitted by second green light-emitting layer 25G, but the present disclosure is not limited thereto.

[0148] For example, the first light-emitting layer 23 can emit blue light, yellow light, or the like.

[0149] By making the wavelength of light emitted by the first light-emitting layer 23 shorter than the wavelength of light emitted by at least one color of the second light-emitting layer 25, when the light emitted by the first light-emitting layer 23 is radiated to the multiple second light-emitting layers 25, at least one of the second red light-emitting layer 25R, the second green light-emitting layer 25G, and the second blue light-emitting layer 25B can be excited to emit light of the corresponding color. This improves the luminance and luminous efficiency of the display substrate 100. 6 As shown in Fig. 1, the light emitted by the first light-emitting layer 23 can be reflected multiple times within the microcavity A. This allows the light emitted by the first light-emitting layer 23 to be radiated multiple times to the plurality of second light-emitting layers 25, further improving the excitation effect of the light emitted by the first light-emitting layer 23 on at least one of the plurality of second light-emitting layers 25, and further improving the luminance and luminous efficiency of the display substrate 100.

[0150] In addition, when the plurality of second light-emitting layers 25 includes a plurality of second blue light-emitting layers 25B, a plurality of second red light-emitting layers 25R, and a plurality of second green light-emitting layers 25G, h is the refractive index of the h-th film layer among the a film layers for the central wavelength of red light, green light, or blue light, and i is the refractive index of the ith film layer among the b film layers for the central wavelength of red light, green light, or blue light.

[0151] For example, the wavelength range of red light is 615 nm to 630 nm, the wavelength range of green light is 515 nm to 535 nm, and the wavelength range of blue light is 460 nm to 475 nm.

[0152] In some embodiments, first light-emitting layer 23 includes a first guest material and second light-emitting layer 25 includes a second guest material, the emission spectrum of which at least partially overlaps with the absorption spectrum of the second guest material of second light-emitting layer 25 for at least one color.

[0153] The materials for the first light-emitting layer 23 and the second light-emitting layer 25 include a host material and a guest material doped into the host material. The host material itself has good film-forming properties and can be mixed with other materials having excellent light-emitting properties, while the guest material itself has excellent light-emitting properties. Thus, when the first light-emitting layer 23 or the second light-emitting layer 25 is commonly formed using a host material and a guest material doped therein, the host material contains molecules in a high excited energy state, and these molecules in the high excited energy state can transfer their energy to the guest material, thereby changing the wavelength of light emitted by the first light-emitting layer 23 or the second light-emitting layer 25 and simultaneously improving the luminous efficiency of the first light-emitting layer 23 or the second light-emitting layer 25.

[0154] For example, the first guest material is a material that is mainly used in the first light-emitting layer 23 to emit light, and the second guest material is a material that is mainly used in the second light-emitting layer 25 to emit light.

[0155] The above phrase "at least partially overlap" means that the emission spectrum of the first guest material partially overlaps with the absorption spectrum of the second guest material of the second light-emitting layer 25 of at least one color, or that the emission spectrum of the first guest material entirely overlaps with the absorption spectrum of the second guest material of the second light-emitting layer 25 of at least one color.

[0156] Illustratively, the emission spectrum of the first guest material in the first light-emitting layer 23 at least partially overlaps with the absorption spectrum of the second guest material in the second red light-emitting layer 25R, or the emission spectrum of the first guest material in the first light-emitting layer 23 at least partially overlaps with the absorption spectrum of the second guest material in the second green light-emitting layer 25G. Alternatively, the emission spectrum of the first guest material in the first light-emitting layer 23 at least partially overlaps with the absorption spectrum of the second guest material in the second blue light-emitting layer 25B, or the emission spectrum of the first guest material in the first light-emitting layer 23 not only at least partially overlaps with the absorption spectrum of the second guest material in the second red light-emitting layer 25R, but also at least partially overlaps with the absorption spectrum of the second guest material in the second green light-emitting layer 25G. Example ofis not limited to this.

[0157] By at least partially overlapping the emission spectrum of the first guest material of the first light-emitting layer 23 with the absorption spectrum of the second guest material of the at least one color second light-emitting layer 25, a portion of the light emitted by the first guest material of the first light-emitting layer 23 is absorbed by the second guest material of the at least one color second light-emitting layer 25. As a result, the second guest material of the at least one color second light-emitting layer 25 emits light upon excitation by the light emitted by the first guest material, thereby improving the luminous efficiency of the second guest material of the second light-emitting layer 25. Here, another portion of the light emitted by the first guest material of the first light-emitting layer 23 is emitted through the cathode layer 27 and forms a series light-emitting element together with the light emitted by the second light-emitting layer 25, thereby improving the luminance of the display substrate 100.

[0158] In addition, when the light emitted by the first light-emitting layer 23 in the display substrate 100 is radiated to the second light-emitting layer 25, the second light-emitting layer 25 can absorb the light emitted by the first light-emitting layer 23 and excite light of a corresponding color. Furthermore, the first light-emitting layer 23 and the second light-emitting layer 25 themselves can form a series light-emitting assembly. The cooperation of the above two light-emitting mechanisms allows the display substrate 100 to achieve higher light-emitting efficiency.

[0159] It can be understood that the greater the overlap between the emission spectrum of the first guest material and the absorption spectrum of the second guest material in the second light-emitting layer 25, the more light emitted by the first guest material can excite the second guest material to emit more light, and the higher the luminous efficiency of the second guest material in the second light-emitting layer 25.

[0160] In some embodiments, the overlap range between the emission spectrum of the first guest material in the first light-emitting layer 23 and the absorption spectrum of the second guest material in the second light-emitting layer 25 is 60% or more of the wavelength range of the emission spectrum of the first guest material.

[0161] For example, the overlap range between the emission spectrum of the first guest material and the absorption spectrum of the second guest material may be 60%, 70%, 80%, 90%, or 99% of the wavelength range of the emission spectrum of the first guest material.

[0162] With this arrangement, 60% or more of all the light emitted by the first guest material is absorbed by the second guest material, thereby improving the utilization rate of the light emitted by the first guest material by the second guest material.

[0163] In some embodiments, the overlap range between the emission spectrum of the first guest material in the first light-emitting layer 23 and the absorption spectrum of the second guest material in the second light-emitting layer 25 is 60% or more of the wavelength range of the absorption spectrum of the second guest material.

[0164] For example, the overlap range between the emission spectrum of the first guest material and the absorption spectrum of the second guest material may be 60%, 70%, 80%, 90%, or 99% of the wavelength range of the absorption spectrum of the second guest material.

[0165] This arrangement allows more of the light emitted by the first guest material to be absorbed by the second guest material, thereby improving the efficiency of the second guest material in utilizing the light emitted by the first guest material.

[0166] In some embodiments, the emission spectrum of the first guest material of the first light-emitting layer 23 has a peak value of less than 600 nm.

[0167] For example, the peak value of the emission spectrum of the first guest material of the first light-emitting layer 23 may be 465 nm, 500 nm, 515 nm, 560 nm, 595 nm, or the like.

[0168] As mentioned above, the shorter the wavelength of light, the higher the energy of the light. This configuration ensures that the light emitted from the first light-emitting layer 23 has relatively high energy, which allows the second guest material in the second light-emitting layer 25 to be more easily excited and emit light.

[0169] In some embodiments, the first guest material of the first light-emitting layer 23 includes at least one light-emitting material. When the first guest material includes two light-emitting materials, the distance between the peak values ​​of the emission spectra of the two light-emitting materials is 30 nm or less.

[0170] Illustratively, the number of types of light-emitting materials contained in the first guest material may be one or two, but the present disclosure is not limited thereto.

[0171] It is understood that different light-emitting materials can emit light of different colors, and when the first guest material of the first light-emitting layer 23 includes one type of light-emitting material, the first light-emitting layer 23 can emit light of one color, and when the first guest material of the first light-emitting layer 23 includes two types of light-emitting materials, the first light-emitting layer 23 can emit light of two colors.

[0172] For example, when the first guest material of the first light-emitting layer 23 includes two light-emitting materials, the distance between the peak values ​​of the emission spectra of the two light-emitting materials may be 1 nm, 10 nm, 19 nm, 25 nm, 30 nm, or the like.

[0173] By setting the distance between the peak values ​​of the emission spectra of the two light-emitting materials in the first guest material to 30 nm or less, the colors of the light emitted by the two light-emitting materials in the first guest material can be made more similar, thereby improving the color purity of the light emitted by the first light-emitting layer 23.

[0174] In some embodiments, the emission spectrum of the first guest material in first light-emitting layer 23 and the absorption spectrum of the second guest material in second green light-emitting layer 25G overlap.

[0175] Illustratively, the light emitted by the first guest material is blue light.

[0176] For example, the emission spectrum of the first guest material has a peak value in the range of 465 nm to 475 nm, and the absorption spectrum of the second guest material of the second green light-emitting layer 25G has a peak value in the range of 507 nm to 517 nm.

[0177] For example, the peak value of the emission spectrum of the first guest material may be 465 nm, 467 nm, 469 nm, 471 nm, 475 nm, etc. The peak value of the absorption spectrum of the second guest material of the second green light-emitting layer 25G may be 507 nm, 509 nm, 512 nm, 514 nm, 517 nm, etc.

[0178] This arrangement allows the emission spectrum of the first guest material and the absorption spectrum of the second guest material to have a larger overlap range, thereby improving the luminous efficiency of the second guest material in the second light-emitting layer 25.

[0179] In some embodiments, the emission spectrum of the first guest material in first light-emitting layer 23 and the absorption spectrum of the second guest material in bi-color second light-emitting layer 25 have overlap.

[0180] Illustratively, the light emitted by the first guest material is green light.

[0181] For example, the emission spectrum of the first guest material has a peak value in the range of 525 nm to 535 nm, the absorption spectrum of the second guest material of the second green light-emitting layer 25G has a peak value in the range of 510 nm to 520 nm, and the absorption spectrum of the second guest material of the second red light-emitting layer 25R has a peak value in the range of 595 nm to 605 nm.

[0182] For example, the peak value of the emission spectrum of the first guest material may be 525 nm, 527 nm, 529 nm, 531 nm, 535 nm, etc. The peak value of the absorption spectrum of the second guest material of the second green light-emitting layer 25G may be 510 nm, 514 nm, 516 nm, 518 nm, 520 nm, etc. The peak value of the absorption spectrum of the second guest material of the second red light-emitting layer 25R may be 595 nm, 597 nm, 600 nm, 602 nm, 605 nm, etc.

[0183] By this arrangement, the emission spectrum of the first guest material in the first light-emitting layer 23 and Two-color Since the absorption spectra of the second guest materials of the second light-emitting layers 25 can overlap with each other in a larger range, the luminous efficiency of the second guest material of the second light-emitting layers 25 can be improved.

[0184] In some embodiments, when the first guest material of the first light-emitting layer 23 includes two light-emitting materials, at least one of the two light-emitting materials is doped with boron, and the doping ratio of the boron is in the range of 0.5% to 5%.

[0185] Illustratively, the doping rate of the boron element may be 0.5%, 1.5%, 3.5%, 4%, or 5%, etc.

[0186] In some embodiments, the first guest material of the first light-emitting layer 23 includes at least one of a fluorescent material, a phosphorescent material, and a thermally activated delayed fluorescent material.

[0187] Illustratively, fluorescent materials include pyrene-based, fused carbazole-based, and boron-containing materials. Phosphorescent materials include iridium (Ir) and platinum (Pt) complexes. Thermally activated delayed fluorescent materials generally have a DA structure, and S1-T1<0.3 eV, where S1 represents the singlet excited energy level of the material, and T1 represents the triplet excited energy level of the material.

[0188] In some embodiments, first light-emitting layer 23 further comprises a first host material. The first host material of first light-emitting layer 23 comprises a single host material or a PN mixed host material.

[0189] Illustratively, the first host material includes at least one of an anthracene-based material, a fluorene-based material, a pyrene-based material, and a carbazole-based derivative material. In some embodiments, the thickness of the first light-emitting layer 23 ranges from 15 nm to 60 nm.

[0190] Illustratively, the thickness of the first light-emitting layer 23 may be 15 nm, 20 nm, 35 nm, 45 nm, 60 nm, or the like.

[0191] In some embodiments, the second guest material of the at least one color second emissive layer 25 comprises at least one emissive material. When the second guest material comprises two emissive materials, the separation between the peak values ​​of the emission spectra of the two emissive materials is 30 nm or less.

[0192] Optionally, the second red-light-emitting layer may comprise at least one light-emitting material, or the second green-light-emitting layer may comprise at least one light-emitting material, or the second blue-light-emitting layer may comprise at least one light-emitting material. Optionally, the second red-light-emitting layer and the second green-light-emitting layer may all comprise at least one light-emitting material.

[0193] For example, the number of types of light-emitting materials contained in the second guest material may be one or two, although the present disclosure is not limited thereto.

[0194] It is understood that different light-emitting materials can emit light of different colors, and when the second guest material of the second light-emitting layer 25 includes one type of light-emitting material, the second light-emitting layer 25 can emit light of one color, and when the second guest material of the second light-emitting layer 25 includes two types of light-emitting materials, the second light-emitting layer 25 can emit light of two colors.

[0195] For example, when the second guest material of the second light-emitting layer 25 contains two light-emitting materials, the emission spectrum of one of the two light-emitting materials overlaps with the absorption spectrum of the other light-emitting material, thereby improving the luminous efficiency of the two light-emitting materials.

[0196] For example, when the second guest material of the second light-emitting layer 25 includes two light-emitting materials, the distance between the peak values ​​of the emission spectra of the two light-emitting materials may be 1 nm, 10 nm, 19 nm, 25 nm, 30 nm, or the like.

[0197] By setting the distance between the peak values ​​of the emission spectra of the two light-emitting materials in the second guest material of the second light-emitting layer 25 to 30 nm or less, the colors of the light emitted by the two light-emitting materials in the second guest material can be made more similar, thereby improving the color purity of the light emitted by the second light-emitting layer 25.

[0198] In some embodiments, when the second guest material of the second light-emitting layer 25 of at least one color contains two light-emitting materials, at least one of the two light-emitting materials is doped with boron, and the doping ratio of the boron element is in the range of 0.5% to 5%.

[0199] Illustratively, the doping rate of the boron element may be 0.5%, 1.5%, 3.5%, 4%, or 5%, etc.

[0200] In some embodiments, the second guest material is a fluorescent material, a phosphorescent material, or a multi-resonance material. (MR) The material contains at least one of thermally activated delayed fluorescent materials having the following properties.

[0201] In some embodiments, at least one color second light-emitting layer 25 further comprises a second host material, which comprises a bipolar host material.

[0202] In some embodiments, the second host material is a single host material or a PN mixed host material.

[0203] In some examples, when the second host material is a PN mixed host material, in PN mixed host materials The N-type component has thermally activated delayed fluorescence properties.

[0204] When the N-type component has thermally activated delayed fluorescence properties, the luminous efficiency of the second guest material in the second light-emitting layer 25 can be improved.

[0205] In some embodiments, the thickness of second light-emitting layer 25 ranges from 10 nm to 50 nm.

[0206] Illustratively, the thickness of the second light-emitting layer 25 may be 10 nm, 20 nm, 28 nm, 38 nm, 50 nm, or the like.

[0207] 6 , the microcavity A includes a plurality of sub-microcavities A1, including a red sub-microcavity A1-R corresponding to the second red light-emitting layer 25R, a green sub-microcavity A1-G corresponding to the second green light-emitting layer 25G, and a blue sub-microcavity A1-B corresponding to the second blue light-emitting layer 25B. The number of film layers corresponding to the sub-microcavities A1 of any one color located between the anode layer 21 and the cathode layer 27 is d, and the optical thickness of the d film layers is L, where L satisfies the following formula:

number

[0208] In the formula, d is a positive integer, n m is the refractive index of the mth film layer among the d film layers, and r m is the thickness of the mth film layer, k is a natural number, λ is the target spectral peak wavelength, and φ is the phase shift caused by the target light after it is reflected by the anode layer 21.

[0209] In addition, when the plurality of second light-emitting layers 25 includes a plurality of second blue light-emitting layers 25B, a plurality of second red light-emitting layers 25R, and a plurality of second green light-emitting layers 25G, m is the refractive index of the m-th film layer among the d film layers for the central wavelength of red light, green light, or blue light.

[0210] For example, when required for interference of blue light, λ is the wavelength of blue light; when required for interference of red light, λ is the wavelength of red light; and when required for interference of green light, λ is the wavelength of green light.

[0211] For example, when L of the red sub-microcavity A1-R satisfies the above formula, the red light emitted from the second red light-emitting layer 25R can generate a microcavity effect within the red sub-microcavity A1-R, thereby increasing the brightness and color purity of the red light.

[0212] Similarly, the green light emitted by the second green light-emitting layer 25G and the blue light emitted by the second blue light-emitting layer 25B also generate a microcavity effect in the corresponding sub-microcavity A1, thereby increasing the brightness and color purity of the green light and blue light.

[0213] In some embodiments, the length of the blue sub-microcavity A1-B is less than the length of the red sub-microcavity A1-R, and the length of the blue sub-microcavity A1-B is less than the length of the green sub-microcavity A1-G.

[0214] For example, the wavelength range of red light is 615 nm to 630 nm, the wavelength range of green light is 515 nm to 535 nm, blue The wavelength range of the color light is 460 nm to 475 nm. Therefore, when the red light, the green light, and the blue light can all produce the microcavity effect, the length of the blue sub-microcavity A1-B is the shortest.

[0215] Any one of the first auxiliary layer 22, the second auxiliary layer 24, and the third auxiliary layer 26 may include one film layer or multiple film layers stacked in sequence, and when any one of the first auxiliary layer 22, the second auxiliary layer 24, and the third auxiliary layer 26 includes multiple film layers, each film layer may have a different function, thereby allowing the first auxiliary layer 22, the second auxiliary layer 24, and the third auxiliary layer 26 to have multiple functions.

[0216] In some examples, as shown in FIG. 7, the first auxiliary layer 22 includes a light-transmitting conductive layer 221, a hole injection layer 222, a first hole transport layer 223, and an electron blocking layer 224.

[0217] The light-transmitting conductive layer 221 has good light transmittance and conductivity, and when light is radiated into the light-transmitting conductive layer 221, the light can pass through the light-transmitting conductive layer 221 and be radiated to the anode layer 21. Since the anode layer 21 has relatively good light reflecting performance, the light can be reflected by the anode layer 21 and the light-transmitting conductive layer 221.

[0218] Illustratively, the material of the light-transmitting conductive layer 221 may include, for example, ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), or the like.

[0219] Illustratively, the thickness of the light-transmitting conductive layer 221 is 10 nm or less. Optionally, the thickness range of the light-transmitting conductive layer 221 is 5 nm to 10 nm.

[0220] For example, the thickness of the light-transmitting conductive layer 221 may be 5 nm, 6.5 nm, 8 nm, 9 nm, 10 nm, or the like.

[0221] Illustratively, the hole injection layer 222 can be formed by doping the material of the first hole transport layer 223 with a P-type dopant (e.g., MnO3, F4TCNQ, etc.), where the doping ratio of the P-type dopant is 5% or less, and the thickness of the hole injection layer 222 is 10 nm or less.

[0222] For example, the doping ratio of the P-type dopant in the material of the first hole transport layer 223 may be 1%, 2%, 3%, 4%, or 5%, etc. The thickness of the hole injection layer 222 may be 1 nm, 3 nm, 5 nm, 8 nm, or 10 nm, etc.

[0223] For example, the material of the first hole transport layer 223 includes a carbazole-based material having a relatively high hole transport rate. The first hole transport layer 223 can be manufactured and formed by a vapor deposition process.

[0224] Illustratively, the thickness of the electron blocking layer 224 is 10 nm or less. For example, the thickness of the electron blocking layer 224 may be 1 nm, 3 nm, 5 nm, 8 nm, 10 nm, or the like.

[0225] For example, the HOMO (Highest Occupied Molecular Orbital) energy levels of the material of the hole injection layer 222, the HOMO energy level of the material of the first hole transport layer 223, and the HOMO energy level of the material of the electron blocking layer 224 increase sequentially. This arrangement reduces the hole injection barrier and increases the hole transitivity, which is favorable for holes to be injected from the anode layer 21 and sequentially transported into the first light-emitting layer 23. This increases the amount of holes accumulated in the first light-emitting layer 23 and improves the luminous efficiency and luminous lifetime of the first light-emitting layer 23.

[0226] Exemplarily, the HOMO energy level ranges from −5.2 eV to −5.6 eV for the material of the first hole transport layer 223. For example, the HOMO energy level of the material of the first hole transport layer 223 may be −5.2 eV, −5.3 eV, −5.4 eV, −5.5 eV, or −5.6 eV.

[0227] Illustratively, the HOMO energy level range of the material of the electron blocking layer 224 is −5.5 eV to −5.9 eV. For example, the HOMO energy levels of the material of the electron blocking layer 224 include −5.5 eV, −5.6 eV, −5.7 eV, −5.8 eV, −5.9 eV, etc.

[0228] For example, T1 of the material of the electron blocking layer 224 is greater than T1 of the light-emitting material in the first light-emitting layer 23. This prevents electrons and / or excitons from leaking out of the first light-emitting layer 23, maintains the concentration of electrons and / or excitons in the first light-emitting layer 23, and ensures the luminous efficiency of the first light-emitting layer 23.

[0229] For example, the T 1 of the material of electron blocking layer 224 is at least 0.2 eV higher than the T 1 of the light-emitting material in first light-emitting layer 23 .

[0230] In some examples, as shown in FIG. 7, the second auxiliary layer 24 includes a first hole-blocking layer 241, a first electron-transporting layer 242, a first charge-generating layer 243, a second charge-generating layer 244, and a microcavity-adjusting layer 245.

[0231] Illustratively, the absolute value of the HOMO energy level of the material of the first hole blocking layer 241 is greater than the absolute value of the HOMO energy level of the material of the first light-emitting layer 23. The first hole blocking layer 241 is used to prevent holes and / or excitons from leaking out of the first light-emitting layer 23.

[0232] For example, the absolute value of the HOMO energy level of the material of the first hole-blocking layer 241 is at least 0.2 eV greater than the absolute value of the HOMO energy level of the material of the first light-emitting layer 23 .

[0233] Illustratively, the T 1 of the material of the first hole blocking layer 241 is higher than the T 1 of the light-emitting material contained in the first light-emitting layer 23 .

[0234] For example, the T 1 of the material of first hole-blocking layer 241 is at least 0.2 eV higher than the T 1 of the light-emitting material contained in first light-emitting layer 23 .

[0235] Illustratively, the material of the first hole blocking layer 241 includes a triazine-based material.

[0236] Exemplarily, the thickness of the first hole blocking layer 241 is 10 nm or less, for example, 1 nm, 3 nm, 5 nm, 8 nm, or 10 nm.

[0237] For example, the material of the first electron transport layer 242 includes at least one material selected from the group consisting of a thiophene-based material, an imidazole-based material, an azine-based derivative material, and lithium quinolate. The first electron transport layer 242 can be obtained by blending a thiophene-based material, an imidazole-based material, an azine derivative material, or the like with lithium quinolate, where the mass ratio of lithium quinolate ranges from 30% to 70%.

[0238] For example, the mass proportion of the lithium quinolate is 30%, 40%, 50%, 60%, or 70%.

[0239] Illustratively, the thickness range of the first electron transport layer 242 is 15 nm to 50 nm. For example, the thickness of the first electron transport layer 242 is 15 nm, 23 nm, 35 nm, 40 nm, or 50 nm.

[0240] For example, the first charge generation layer 243 and the second charge generation layer 244 are used to improve the overall light emission brightness of the display substrate 100 by forming the first light emitting layer 23 and the second light emitting layer 25 in the light emitting element layer 2 in series emission.

[0241] Illustratively, the first charge generating layer 243 is made of a material that is low in conductivity compared to the material of the first electron transport layer 242. work The first charge generation layer 243 can be formed by doping with a functional metal (lithium (Li), ytterbium (Yb), calcium (Ca), etc.), and the doping rate is 5% or less. The thickness of the first charge generation layer 243 is 10 nm or less.

[0242] For example, the doping ratio of the low-function metal may be 1%, 2%, 3%, 4%, or 5%, etc. The thickness of the first charge generation layer 243 may be 1 nm, 3 nm, 5 nm, 8 nm, or 10 nm, etc.

[0243] For example, the second charge generation layer 244 can be formed by doping the material of the second hole transport layer 2451 described below with a P-type dopant (e.g., MnO3 or F4TCNQ, etc.), and the doping rate is 5% or less. Second charge generation layer 244 The thickness is 10 nm or less.

[0244] For example, the doping ratio of the P-type dopant may be 1%, 2%, 3%, 4%, or 5%, etc. The thickness of the second charge generation layer 244 may be 1 nm, 3 nm, 5 nm, 8 nm, or 10 nm, etc.

[0245] Optionally, the first charge generation layer 243 may be referred to as an N-type charge generation layer (N-CGL), and the second charge generation layer 244 may be referred to as a P-type charge generation layer (P-CGL).

[0246] For example, the thickness of the microcavity adjusting layer 245 is adjustable, and by adjusting the thickness of the microcavity adjusting layer 245, the lengths of the sub-microcavities A1 can be adjusted, so that the light corresponding to the sub-microcavities A1 can all generate the microcavity effect.

[0247] In some embodiments, FIG. and Figure 7 1, the microcavity adjusting layer 245 includes a second hole transport layer 2451, a red sub-microcavity adjusting layer 245R provided between the second hole transport layer 2451 and the second red light-emitting layer 25R, a green sub-microcavity adjusting layer 245G provided between the second hole transport layer 2451 and the second green light-emitting layer 25G, and a blue sub-microcavity adjusting layer 245B provided between the second hole transport layer 2451 and the second blue light-emitting layer 25B. Here, the red sub-microcavity adjusting layer 245R and the blue sub-microcavity adjusting layer 245B have different thicknesses, and the green sub-microcavity adjusting layer 245G and the blue sub-microcavity adjusting layer 245B have different thicknesses.

[0248] Illustratively, the second hole transport layer 245 1 The material of the second hole transport layer 245 includes a carbazole-based material having a relatively high hole transport rate. 1 can be fabricated and formed by a vapor deposition process.

[0249] Illustratively, the second hole transport layer 245 1 is used to reduce the hole injection barrier and increase the hole transition rate, which is advantageous for the transport of holes into the second light-emitting layer 25. This can increase the amount of holes accumulated in the second light-emitting layer 25, and improve the luminous efficiency and luminous lifetime of the second light-emitting layer 25.

[0250] For example, the second hole transport layer 245 1 The HOMO energy level of the material of the second hole transport layer 2451 ranges from −5.2 eV to −5.6 eV, for example, the HOMO energy levels of the material of the second hole transport layer 2451 include −5.2 eV, −5.3 eV, −5.4 eV, −5.5 eV, and −5.6 eV.

[0251] Illustratively, the T 1 of the material of red sub-microcavity adjusting layer 245 R, green sub-microcavity adjusting layer 245 G, and blue sub-microcavity adjusting layer 245 B is higher than the T 1 of the luminescent material of second light-emitting layer 25 .

[0252] For example, the T 1 of the material of red sub-microcavity adjusting layer 245 R, green sub-microcavity adjusting layer 245 G, and blue sub-microcavity adjusting layer 245 B is at least 0.2 eV higher than the T 1 of the luminescent material of second luminescent layer 25 .

[0253] Illustratively, the thickness of blue sub-microcavity-adjusting layer 245B is 10 nm or less.

[0254] For example, the thickness of the blue sub-microcavity adjusting layer 245B may be 1 nm, 3 nm, 5 nm, 7 nm, 10 nm, or the like.

[0255] For example, the thickness of the second hole transport layer 2451, the thickness of the red sub-microcavity adjusting layer 245R, the thickness of the green sub-microcavity adjusting layer 245G, and the thickness of the blue sub-microcavity adjusting layer 245B can all be adjusted individually. By adjusting the thickness of the second hole transport layer 2451, the thickness of the red sub-microcavity adjusting layer 245R, the thickness of the green sub-microcavity adjusting layer 245G, and the thickness of the blue sub-microcavity adjusting layer 245B, the lengths of the sub-microcavities A1 can be adjusted, and the light corresponding to the sub-microcavities A1 can all generate the microcavity effect.

[0256] As mentioned above, when red light, green light, and blue light have different wavelengths and can all generate a microcavity effect, the red light sub-microcavity A1-R and the blue light sub-microcavity A1-B have different lengths, and the green light sub-microcavity A1-G and the blue light sub-microcavity A1-B have different lengths. As shown in Figure 6, multiple sub-microcavities A1 share the first auxiliary layer 22, the first light-emitting layer 23, some film layers in the second auxiliary layer 24, and the third auxiliary layer 26. The red sub-microcavity adjusting layer 245R and the blue sub-microcavity adjusting layer 245B in the second auxiliary layer 24 have different thicknesses, and the green sub-microcavity adjusting layer 245G and the blue sub-microcavity adjusting layer 245B in the second auxiliary layer 24 have different thicknesses, thereby forming a red sub-microcavity. By simply adjusting the thicknesses of the thickness adjusting layer 245R, the green sub-microcavity adjusting layer 245G, and the blue sub-microcavity adjusting layer 245B, the sub-microcavities A1 can be made to have desired lengths, and the shared film layers (e.g., the first auxiliary layer 22, the first light-emitting layer 23, and the third auxiliary layer 26) in the blue sub-microcavity A1-B, the red sub-microcavity A1-R, and the green sub-microcavity A1-G can be made to have the same thickness. This simplifies the manufacturing process of the shared film layers, and correspondingly simplifies the manufacturing process of the display substrate 100.

[0257] The thicknesses of the second hole transport layer 2451, the red sub-microcavity adjusting layer 245R, the green sub-microcavity adjusting layer 245G, and the blue sub-microcavity adjusting layer 245B have a relatively small effect on the electrical performance of the light-emitting element layer 2 on the display substrate 100. By adjusting the thicknesses of the second hole transport layer 2451, the red sub-microcavity adjusting layer 245R, the green sub-microcavity adjusting layer 245G, and the blue sub-microcavity adjusting layer 245B, the lengths of the sub-microcavities A1 can be adjusted, and the effect on the electrical performance of the light-emitting element layer 2 on the display substrate 100 can be reduced.

[0258] It will be understood that any one of the red sub-microcavity adjusting layer 245R, the green sub-microcavity adjusting layer 245G, and the blue sub-microcavity adjusting layer 245B may include a single film layer, or any one of the red sub-microcavity adjusting layer 245R, the green sub-microcavity adjusting layer 245G, and the blue sub-microcavity adjusting layer 245B may include multiple film layers stacked in sequence.

[0259] In some embodiments, as shown in FIG. 3 , the red sub-microcavity adjusting layer 245R includes a red hole transport layer 245R-1 and a red electron blocking layer 245R-2 stacked in sequence in a direction away from the backplate 1, and the green sub-microcavity adjusting layer 245G includes a green hole transport layer 245G-1 and a green electron blocking layer 245G-2 stacked in sequence in a direction away from the backplate 1.

[0260] For example, the red hole transport layer 245R-1 can reduce the hole injection barrier, allowing holes to be injected from the second auxiliary layer 24 and transported to the second red light-emitting layer 25. R This favors transporting the red light-emitting element into the second red-light-emitting layer 25. R and improves the amount of holes accumulated in the second red light-emitting layer 25. R The green hole-transporting layer 245G-1 can reduce the hole injection barrier, which is advantageous for holes to be injected from the second auxiliary layer 24 and transported into the second green light-emitting layer 25G. This can increase the amount of holes accumulated in the second green light-emitting layer 25G, and improve the light-emitting efficiency and light-emitting lifetime of the second green light-emitting layer 25G.

[0261] Illustratively, red electron blocking layer 245R-2 prevents electrons and / or excitons from entering second red light-emitting layer 25 R and blocking electrons and / or excitons from overflowing from the second red light-emitting layer 25 R This allows the second red light-emitting layer 25 Rto increase the concentration of electrons and / or excitons in the second red light-emitting layer 25 R The green electron blocking layer 245G-2 is used to block electrons and / or excitons from overflowing from the second green light-emitting layer 25G, thereby confining the electrons and / or excitons within the second green light-emitting layer 25G. This increases the concentration of electrons and / or excitons in the second green light-emitting layer 25G, thereby improving the light-emitting luminance and light-emitting efficiency of the second green light-emitting layer 25G.

[0262] In some examples, red hole transport layer 245R-1 and green hole transport layer 245G-1 are used to adjust the length of sub-microcavity A1, respectively.

[0263] It is understood that by changing the thickness of the red hole transport layer 245R-1 and the green hole transport layer 245R-1, the lengths of the corresponding red sub-microcavities A1-R and green sub-microcavities A1-G can be changed, provided that the thicknesses of other film layers (e.g., the first auxiliary layer 22, the first light-emitting layer 23, etc.) are not changed.

[0264] For example, the length of the red sub-microcavity A1-R can be changed by changing the thickness of the red hole transport layer 245R-1. This allows the red light to generate a microcavity effect in the red sub-microcavity A1-R, thereby improving the brightness and color purity of the red light. Furthermore, the wavelength of light capable of generating a microcavity effect in the red sub-microcavity A1-R can be changed, thereby adjusting the color of the light emitted from the red sub-microcavity A1-R. The length of the green sub-microcavity A1-G can be changed by changing the thickness of the green hole transport layer 245R-1. This allows the green light to generate a microcavity effect in the green sub-microcavity A1-G, thereby improving the brightness and color purity of the green light. Furthermore, the wavelength of light capable of generating a microcavity effect in the green sub-microcavity A1-G can be changed, thereby adjusting the color of the light emitted from the green sub-microcavity A1-G.

[0265] In some examples, as shown in FIG. 7, the third auxiliary layer 26 includes a second hole-blocking layer 261, a second electron-transporting layer 262, and an electron-injecting layer 263.

[0266] Illustratively, the absolute value of the HOMO energy level of the material of the second hole blocking layer 261 is greater than the absolute value of the HOMO energy level of the material of the second light-emitting layer 25. The second hole blocking layer 261 is used to prevent holes and / or excitons from leaking out of the second light-emitting layer 25.

[0267] For example, the absolute value of the HOMO energy level of the material of second hole-blocking layer 261 is at least 0.2 eV greater than the absolute value of the HOMO energy level of the material of second light-emitting layer 25 .

[0268] Illustratively, the T 1 of the material of second hole-blocking layer 261 is higher than the T 1 of the light-emitting material contained in second light-emitting layer 25 .

[0269] For example, the T 1 of the material of second hole-blocking layer 261 is at least 0.2 eV higher than the T 1 of the light-emitting material contained in second light-emitting layer 25 .

[0270] Illustratively, the material of the second hole blocking layer 261 includes a triazine-based material.

[0271] Illustratively, the thickness of the second hole blocking layer 261 is 10 nm or less. For example, the thickness of the second hole blocking layer 261 may be 1 nm, 3 nm, 5 nm, 8 nm, 10 nm, or the like.

[0272] For example, the material of the second electron transport layer 262 includes at least one of a thiophene-based material, an imidazole-based material, an azine-based derivative material, and lithium quinolate. The second electron transport layer 262 can be obtained by blending a thiophene-based material, an imidazole-based material, or an azine-based derivative material with lithium quinolate, where the mass ratio of lithium quinolate ranges from 30% to 70%.

[0273] For example, the mass proportion of the lithium quinolate may be 30%, 40%, 50%, 60%, or 70%.

[0274] Illustratively, the thickness range of the second electron transport layer 262 is 15 nm to 50 nm. For example, the thickness of the second electron transport layer 262 may be 15 nm, 23 nm, 35 nm, 40 nm, or 50 nm.

[0275] For example, the electron injection layer 263 is used to reduce the electron injection barrier, which is advantageous for electrons to be injected from the cathode layer 27 and transported into the second light-emitting layer 25. This increases the amount of electrons accumulated in the second light-emitting layer 25, and can improve the luminous efficiency and luminous lifetime of the second light-emitting layer 25.

[0276] Illustratively, the material of the electron injection layer 263 includes lithium fluoride (LiF), ytterbium (Yb), calcium (Ca), etc. The electron injection layer 263 can be manufactured and formed by a vapor deposition process.

[0277] Illustratively, the thickness range of the electron injection layer 263 is 0.5 nm to 2 nm. For example, the thickness of the electron injection layer 263 may be 0.5 nm, 0.8 nm, 1.2 nm, 1.7 nm, or 2 nm.

[0278] In some examples, as shown in FIG. 7, the display substrate 100 further includes an optical coating layer 3 and / or a sealing layer 4 sequentially stacked on the cathode layer 27 .

[0279] Illustratively, the material of the optical coating layer 3 includes a high refractive index organic material, for example, the refractive index of the optical coating layer 3 for light with a wavelength of 530 nm is greater than 1.9.

[0280] Illustratively, the thickness of the optical coating layer 3 is 100 nm or less. For example, the thickness of the optical coating layer 3 may be 10 nm, 30 nm, 50 nm, 80 nm, 100 nm, or the like.

[0281] For example, the sealing layer 4 can prevent the film layers (e.g., the first light-emitting layer 23, the second light-emitting layer 25, etc.) in the display substrate 100 from coming into contact with moisture and oxygen in the air, thereby reducing the aging rate of the film layers and extending the service life of the display substrate 100.

[0282] Exemplarily, the sealing type of the sealing layer 4 includes a sealant seal or a film seal.

[0283] The plurality of second light-emitting layers 25 are located in the same layer and constitute one light-emitting layer group. The present disclosure does not limit the number of first light-emitting layers 23 or the number of light-emitting layer groups; that is, the number of first light-emitting layers 23 and the number of light-emitting layer groups may be one or more.

[0284] In some examples, as shown in FIG. 8, the number of first light-emitting layers 23 is multiple and a second auxiliary layer 24 is provided between any two adjacent first light-emitting layers 23, and / or, as shown in FIG. 9, the number of light-emitting layer groups is multiple and a third auxiliary layer 26 is provided between any two adjacent light-emitting layer groups.

[0285] Illustratively, the number of first light-emitting layers 23 is two, three, four, five, six, or the like.

[0286] By providing multiple first light-emitting layers 23, the total intensity of light that the first light-emitting layers 23 can emit can be increased, thereby increasing the intensity of the excitation light of the second light-emitting layers 25 and increasing the luminance of the display substrate 100.

[0287] By providing multiple light-emitting layer groups, the total intensity of light that can be emitted by the light-emitting layer groups can be increased, which increases the absorption of light emitted by the first light-emitting layer 23 by the light-emitting layer groups, thereby increasing the intensity of excitation light for the light-emitting layer groups and the luminance of the display substrate 100.

[0288] By providing a second auxiliary layer 24 between any two adjacent first light-emitting layers 23 and a third auxiliary layer 26 between any two adjacent light-emitting layer groups, it is ensured that holes and electrons can be transported to the multiple first light-emitting layers 23 and light-emitting layer groups to generate excitons, thereby causing the first light-emitting layers 23 and light-emitting layer groups to emit light.

[0289] The inventors of the present disclosure have verified the color purity and luminous efficiency of the display substrate 100 of the present disclosure.

[0290] Verification Example 1: Includes Comparative Example 1 and Example 1.

[0291] In Comparative Example 1, one display substrate has red, green, and blue light-emitting elements, and the other display substrate has a first blue light-emitting element. Both display substrates are sequentially stacked with an anode layer, a light-transmitting conductive layer, a hole injection layer, a hole transport layer, an electron blocking layer, and a light-emitting layer (e.g., a red light-emitting layer, a green light-emitting layer, a and Blue light-emitting layer or a blue light-emitting layer ), a hole blocking layer, an electron transport layer, an electron injection layer, and a cathode layer.

[0292] In Comparative Example 1, the red light-emitting layer of the red light-emitting device contains a red host material and a red phosphorescent material, and the mass proportion of the red phosphorescent material is 5%. The green light-emitting layer of the green light-emitting device contains a green host material and a green phosphorescent material with multiple resonance properties, and the mass proportion of the green phosphorescent material is 5%. The blue light-emitting layer of the blue light-emitting device contains a blue host material and a deep blue fluorescent material (with an emission spectrum peak of 460 nm), and the mass proportion of the deep blue fluorescent material is 5%. The blue light-emitting layer of the first blue light-emitting device contains a conventional P-type blue host material, a blue light-emitting material with thermally activated delayed fluorescence properties (with an emission spectrum peak of 500 nm), and a boron-containing blue fluorescent material with multiple resonance properties (with an emission spectrum peak of 470 nm), and the mass proportions of the three materials are 79%, 20%, and 1%, respectively.

[0293] The thickness of each film layer corresponding to the light-emitting element in each display substrate of Comparative Example 1 is shown in Table 1 below. [Table 1]

[0294] The display substrate 100 of the first embodiment has red, green, and blue light-emitting elements. The display substrate 100 includes an anode layer, a light-transmitting conductive layer, a hole injection layer, a first hole transport layer, an electron blocking layer, a first light-emitting layer, a first hole blocking layer, a first electron transport layer, a first charge generation layer, a second charge generation layer, a second hole transport layer, and each color Sub It includes a microcavity adjusting layer, a second light-emitting layer for each color, a second hole-blocking layer, a second electron-transporting layer, an electron-injecting layer, and a cathode layer.

[0295] In Example 1, the material of the first light-emitting layer 23 is the same as the material of the light-emitting layer of the first blue light-emitting element in Comparative Example 1, and includes a conventional P-type blue host material, a blue light-emitting material with thermally activated delayed fluorescence properties (the peak value of the emission spectrum is 500 nm), and a boron-containing blue fluorescent material with multiple resonance properties (the peak value of the emission spectrum is 470 nm), and the mass proportions of the above three materials are 79%, 20%, and 1%, respectively.

[0296] In the above Example 1, the second light-emitting layer 25 in the red light-emitting element contains a red host material and a red phosphorescent material, and the mass proportion of the red phosphorescent material is 5%; the second light-emitting layer 25 in the green light-emitting element contains a green host material and a green phosphorescent material having multiple resonance properties, and the mass proportion of the green phosphorescent material is 5%; and the second light-emitting layer 25 in the blue light-emitting element contains a blue host material and a deep blue fluorescent material (with an emission spectrum peak value of 460 nm), and the mass proportion of the deep blue fluorescent material is 5%.

[0297] The thickness of each film layer corresponding to each light-emitting element in the display substrate 100 of Example 1 is shown in Table 2 below. [Table 2]

[0298] Here, in Comparative Example 1 and Example 1, the P-type doping rate of the hole injection layer is 3%, the material of the cathode layer is a magnesium-silver alloy, and the mass ratio of magnesium to silver in the magnesium-silver alloy is 1:9, and the material of the electron transport layer is (8-hydroxyquinoline)lithium.

[0299] As shown in Figure 10, the horizontal axis of the graph represents wavelength (unit: nm), and the vertical axis represents relative spectral intensity. The emission spectra p1 of the emitting layer of the first blue light-emitting device in Comparative Example 1 and the first emitting layer 23 of the blue light-emitting device in Example 1 clearly exhibit double-peak characteristics. This double-peak characteristic is due to the overlap of the emission spectra of the blue light-emitting material (whose emission spectrum peaks at 500 nm) and the boron-containing blue fluorescent material (whose emission spectrum peaks at 470 nm) exhibiting thermally activated delayed fluorescence properties in the first emitting layer 23. The absorption spectrum p2 of the red phosphorescent material in the second emitting layer 25 of the red light-emitting device in Example 1 overlaps with the emission spectrum p1 of the first emitting layer 23 of the blue light-emitting device. Table 3 compares the relationship between each related quantity and the first blue light-emitting device in Comparative Example 1 and Example 1.

[0300] Here, the driving voltage of the first blue light emitting element is 4.5V, the luminance is 1000, the color coordinates are (0.17, 0.32), and the luminous efficiency is 38cd / A. [Table 3]

[0301] As can be seen from the above results, after combining the first light-emitting layer 23 and the second light-emitting layer 25 in series, the blue and green light-emitting elements in Example 1 exhibited several times higher efficiency and several times higher lifespan at the same luminance compared to Comparative Example 1. Since the red light-emitting element in the second light-emitting layer 25 does not contain a luminescent material that can be excited by the light emitted by the first light-emitting layer 23, the red light-emitting element in the second light-emitting layer 25 maintains its original efficiency level and Red light emitting element The color purity of the red light emitted by the red-emitting layer is also unaffected by the microcavity tuning, and although the lifetime of the red-emitting layer is reduced, it still remains at a relatively high level.

[0302] Verification Example 2: Includes Comparative Example 2 and Example 2.

[0303] In Comparative Example 2, one display substrate has red, green, and blue light-emitting elements, and the other display substrate has a first green light-emitting element. The film layers included in the two display substrates are the same as the film layers included in the display substrate in Comparative Example 1.

[0304] In Comparative Example 2, the light-emitting layer in the red light-emitting element contains a P-type red host material, an N-type red host material having thermally activated delayed fluorescence properties, and a red fluorescent material, and the mass proportions of the above three materials are 69%, 30%, and 1%, respectively; the light-emitting layer in the green light-emitting element contains a green host material and a green light-emitting material having multiple resonance properties, and the mass proportion of the green light-emitting material is 1%; and the light-emitting layer in the blue light-emitting element contains a blue host material and a deep blue fluorescent material (the peak value of the emission spectrum is 460 nm), and the mass proportion of the deep blue fluorescent material is 5%.

[0305] The thickness of each film layer corresponding to each light-emitting element in the display substrate of Comparative Example 2 is shown in Table 4 below. [Table 4]

[0306] The structure of the display substrate 100 of the second embodiment is the same as the structure of the display substrate 100 of the first embodiment.

[0307] In Example 2, the material of the first light-emitting layer 23 is the same as the material of the light-emitting layer of the first green light-emitting element in Comparative Example 2, and includes a conventional P-type green host material and a green light-emitting material having thermally activated delayed fluorescence properties (the peak value of the emission spectrum is 460 nm), and the mass proportion of the green light-emitting material having thermally activated delayed fluorescence properties is 30%.

[0308] In Example 2, the second light-emitting layer 25 in the red light-emitting element comprises a P-type red host material, an N-type red host material having thermally activated delayed fluorescence properties, and a red fluorescent material, and the mass proportions of these three materials in the materials of the second light-emitting layer 25 are 69%, 30%, and 1%, respectively; the second light-emitting layer 25 in the green light-emitting element comprises a green host material and a green fluorescent material having multiple resonance properties, and the mass proportion of the green fluorescent material is 1%; and the second light-emitting layer 25 in the blue light-emitting element comprises a blue host material and a deep blue fluorescent material (with an emission spectrum peak at 460 nm), and the mass proportion of the deep blue fluorescent material in the materials of the second light-emitting layer 25 is 5%.

[0309] The thickness of each film layer corresponding to each light-emitting element in the display substrate 100 of Example 2 is shown in Table 5 below. [Table 5]

[0310] The hole injection layer has a P-type doping rate of 3%, the cathode layer is made of a magnesium-silver alloy, and the mass ratio of magnesium to silver in the magnesium-silver alloy is 1:9, and the electron transport layer is made of (8-hydroxyquinoline)lithium.

[0311] 11, the horizontal axis of the graph represents wavelength in nm, and the vertical axis represents relative spectral intensity, and the emission spectrum p3 of the first green light-emitting element of Comparative Example 2 and the first light-emitting layer 23 of Example 2 clearly has single-peak characteristics and overlaps with the absorption spectrum p4 of the second light-emitting layer 25 of the red light-emitting element of Example 2 and the absorption spectrum p5 of the second light-emitting layer 25 of the green light-emitting element. Table 6 shows the comparative relationship between each related quantity in Comparative Example 2 and Example 2 and the first green light-emitting element.

[0312] In Comparative Example 2, the driving voltage of the first green light emitting element is 3.6V, the luminance is 10000, the color coordinates are (0.34, 0.60), and the luminous efficiency is 53 cd / A. [Table 6]

[0313] As can be seen from the above results, in Example 2, after connecting the first light-emitting layer 23 and the second light-emitting layer 25 in series, both the red and green light-emitting elements exhibited higher efficiency and better lifespan levels at the same luminance compared to Comparative Example 2. The second light-emitting layer 25 of the blue light-emitting element was unable to obtain additional gain from the first light-emitting layer 23, and the second light-emitting layer 25 of the blue light-emitting element was unable to obtain additional gain compared to Comparative Example 2. 2 The blue light emitting devices of the present invention have similar efficiency and lifetime levels.

[0314] Verification Example 3: Includes Example 3-1 and Example 3-2.

[0315] The display substrate 100 of Examples 3-1 and 3-2 has red light-emitting elements, green light-emitting elements, and blue light-emitting elements. The display substrate 100 of Examples 3-1 and 3-2 includes an anode layer, a light-transmitting conductive layer, a hole injection layer, a first hole transport layer, an electron blocking layer, a first light-emitting layer, a first hole blocking layer, a first electron transport layer, a first charge generation layer, a second charge generation layer, a second hole transport layer, and each color Sub It includes a microcavity adjusting layer, a second light-emitting layer for each color, a second hole-blocking layer, a second electron-transporting layer, an electron-injecting layer, a cathode layer, and an optical coating layer.

[0316] The thickness of each film layer in the display substrate 100 of Example 3-1 is shown in Table 7 below. [Table 7]

[0317] The thickness of each film layer in the display substrate 100 of Example 3-2 is shown in Table 8 below. [Table 8]

[0318] Here, the P-type doping ratio of the hole injection layer in Examples 3-1 and 3-2 is 3%, the material of the cathode layer is a magnesium-silver alloy, and the mass ratio of magnesium to silver in the magnesium-silver alloy is 1:9, and the material of the electron transport layer is (8-hydroxyquinoline)lithium.

[0319] In Example 3-2, compared with Example 3-1, the optical thickness L1 can be adjusted by adjusting the thickness of the first hole transport layer close to the anode layer 21, and the length of each sub-microcavity A1 is simultaneously modified by adjusting the thickness of the second hole transport layer remote from the anode layer 21. That is, the thickness of the first hole transport layer close to the anode layer 21 in Example 3-2 is 40 nm - 25 nm = 15 nm thicker than the thickness of the first hole transport layer close to the anode layer 21 in Example 3-1, and the thickness of the second hole transport layer remote from the anode layer 21 in Example 3-2 is 15 nm less than the thickness of the second hole transport layer remote from the anode layer 21 in Example 3-1.

[0320] Table 9 shows the results of luminous purity and luminous efficiency for Example 3-1 and Example 3-2. [Table 9]

[0321] As can be seen from the above results, the blue light-emitting element in Example 3-2 has low luminous efficiency and low color purity. The main reason is that the above L1, L2, and L3 corresponding to the blue light-emitting element deviate too much from the optimized sizes and do not satisfy the following formula:

number

[0322] Some other embodiments of the present disclosure further provide a display substrate 100, which includes a backplane 1 and a light-emitting element layer 2, as shown in FIG.

[0323] 12 , the light-emitting element layer 2 includes an anode layer 21, a first auxiliary layer 22, a first light-emitting layer 23, a second auxiliary layer 24, a plurality of second light-emitting layers 25, a third auxiliary layer 26, and a cathode layer 27 provided on the backplate 1. A microcavity A is formed between the anode layer 21 and the cathode layer 27.

[0324] In some examples, the plurality of second light-emitting layers 25 includes a plurality of second blue light-emitting layers 25B, a plurality of second red light-emitting layers 25R, and a plurality of second green light-emitting layers 25G.

[0325] The first auxiliary layer includes a film layers stacked in sequence, the second auxiliary layer includes b film layers stacked in sequence, and the third auxiliary layer includes c film layers stacked in sequence, where a, b, and c are all positive integers.

[0326] The optical thicknesses of the a film layers, the b film layers, and the c film layers satisfy the following formula:

number

[0327]

number

number

[0328] For example,

number

[0329] The average refractive index is calculated by dividing the sum of the optical thicknesses of the film layers located between the anode layer 21 and the cathode layer 27 by the sum of the actual thicknesses of the film layers located between the anode layer 21 and the cathode layer 27. Alternatively, the average refractive index of the film layers between the anode layer 21 and the cathode layer 27 can be directly measured by a refractive index testing device (e.g., a refractometer or an ellipsometer).

[0330] For example,

number

[0331] In some examples, in the display substrate 100 provided by the above embodiments, the difference in refractive index between any two film layers located between the anode layer 21 and the cathode layer 27 is 0.32 or less. This arrangement allows the refractive indexes of any two film layers located between the anode layer 21 and the cathode layer 27 to be relatively close to each other, thereby reducing the difference in refractive index between any two film layers located between the anode layer 21 and the cathode layer 27. This reduces the abrupt change in refractive index between the film layers, allows the light emitting element 2a to have good light emission efficiency, and reduces the dispersion of light emitted by the light emitting element 2a.

[0332] It should be noted that the structure of the display substrate 100 in this embodiment is the same as the structure of the display substrate 100 in some of the above embodiments. Optionally, the backplane 1 in this embodiment has the same characteristics as the backplane in some of the above embodiments, and the light-emitting element layer 2 in this embodiment has the same characteristics as the light-emitting element layer 2 in some of the above embodiments. For details, please refer to the above description, and the description will be omitted here.

[0333] Some other embodiments of the present disclosure further provide a display substrate 100, which includes a backplane 1 and a light-emitting element layer 2, as shown in FIG.

[0334] 13 , the light-emitting element layer 2 includes an anode layer 21, a first auxiliary layer 22, a first light-emitting layer 23, a second auxiliary layer 24, a plurality of second light-emitting layers 25, a third auxiliary layer 26, and a cathode layer 27 provided on the backplate 1. A microcavity A is formed between the anode layer 21 and the cathode layer 27.

[0335] In some instances, the second auxiliary layer 24 includes a charge generating layer 247 .

[0336] Illustratively, the charge generation layer 247 may include an N-type charge generation layer (N-CGL) and a P-type charge generation layer (P-CGL).

[0337] In some examples, first light-emitting layer 23 can emit light of at least two different colors.

[0338] For example, the first light-emitting layer 23 can emit red light and blue light, or the first light-emitting layer 23 can emit green light and blue light, or the first light-emitting layer 23 can emit red light, green light, and blue light.

[0339] Since the first light-emitting layers 23 have two different colors, the first light-emitting layers 23 need to be manufactured and formed using different processes, and the first light-emitting layers 23 of one color can correspond to one process. For example, the first light-emitting layers 23 can be formed using a deposition process, in which the first light-emitting layers 23 of one color are deposited in one process, and then the first light-emitting layers 23 of the other color are deposited in another process.

[0340] In some examples, the plurality of second light-emitting layers 25 includes a plurality of second blue light-emitting layers 25B, a plurality of second red light-emitting layers 25R, and a plurality of second green light-emitting layers 25G.

[0341] The first auxiliary layer 22 includes a number of film layers stacked in sequence, the second auxiliary layer 24 includes b number of film layers stacked in sequence, and the third auxiliary layer 26 includes c number of film layers stacked in sequence, where a, b, and c are all positive integers.

[0342] The optical thicknesses of the a film layers, the b film layers, and the c film layers satisfy the following formula:

number

[0343]

number

number

[0344] For example,

number

[0345] The average refractive index is calculated by dividing the sum of the optical thicknesses of the film layers located between the anode layer 21 and the cathode layer 27 by the sum of the actual thicknesses of the film layers located between the anode layer 21 and the cathode layer 27. Alternatively, the average refractive index of the film layers between the anode layer 21 and the cathode layer 27 can be directly measured by a refractive index testing device (for example, a refractometer or an ellipsometer).

[0346] For example,

number

[0347] In some examples, in the display substrate 100 provided by the above embodiments, the difference in refractive index between any two film layers located between the anode layer 21 and the cathode layer 27 is 0.32 or less. This arrangement allows the refractive indexes of any two film layers located between the anode layer 21 and the cathode layer 27 to be relatively close to each other, thereby reducing the difference in refractive index between any two film layers located between the anode layer 21 and the cathode layer 27. This reduces the abrupt change in refractive index between the film layers, allows the light emitting element 2a to have good light emission efficiency, and reduces the dispersion of light emitted by the light emitting element 2a.

[0348] It should be noted that the structure of the display substrate 100 in this embodiment is the same as the structure of the display substrate 100 in some of the above embodiments. Optionally, the backplane 1 in this embodiment has the same characteristics as the backplane in some of the above embodiments, and the light-emitting element layer 2 in this embodiment has the same characteristics as the light-emitting element layer 2 in some of the above embodiments. For details, please refer to the above description, and the description will be omitted here.

[0349] In some examples, in the display substrate 100 provided by each of the above embodiments, the material types of the film layers between the anode layer 21 and the cathode layer 27 and the refractive index of each film layer for blue light with a wavelength of 460 nm are shown in Table 10 below. [Table 10]

[0350] As can be seen from Table 10, the difference in refractive index between any two of the film layers located between the anode layer 21 and the cathode layer 27 is 0.32 or less, which means that the refractive index of any two of the film layers located between the anode layer 21 and the cathode layer 27 is closer. By selecting the material and refractive index of each film layer located between the anode layer 21 and the cathode layer 27, the difference in refractive index between any two of the film layers located between the anode layer 21 and the cathode layer 27 can be further reduced, and the abrupt change in refractive index between the film layers can be further reduced, resulting in good light emission efficiency for the light emitting element 2a and reduced dispersion of the light emitted by the light emitting element 2a.

[0351] The above are only specific embodiments of the present disclosure, but the scope of protection of the present disclosure is not limited thereto, and any modifications or replacements that can be easily conceived by anyone skilled in the art within the technical scope of the present disclosure are all encompassed within the technical scope of the present disclosure. Therefore, the scope of protection of the present disclosure should be subject to the scope of protection of the claims.

Claims

1. a backplane; an anode layer, a first auxiliary layer, a second auxiliary layer, a third auxiliary layer, and a cathode layer stacked in this order on the backplane, wherein microcavities are formed between the anode layer and the cathode layer; a first light-emitting layer provided between the first auxiliary layer and the second auxiliary layer; a plurality of second light-emitting layers of at least two different colors provided between the second auxiliary layer and the third auxiliary layer; The first auxiliary layer includes a number of film layers laminated in sequence, and the optical thickness of the a number of film layers is L １ and L １ satisfies the following formula, [Equation 1] a is a positive integer, n ｈ is the refractive index of the h-th film layer among the a film layers, r ｈ is the thickness of the h-th film layer, The second auxiliary layer includes b film layers stacked in sequence, and the b film layers have an optical thickness of L ２ and L ２ satisfies the following formula, [Equation 2] b is a positive integer, n ｉ is the refractive index of the i-th film layer among the b film layers, r ｉ is the thickness of the i-th film layer, The third auxiliary layer includes c film layers stacked in sequence, and the c film layers have optical thicknesses L ３ and L ３ satisfies the following formula, [Equation 3] c is a positive integer, n ｊ is the refractive index of the j-th film layer among the c film layers, r ｊ is the thickness of the jth film layer, L １ , L ２ , L ３ satisfies the following formula: [Equation 4] Display board.

2. the plurality of second light-emitting layers include a plurality of second blue light-emitting layers, a plurality of second red light-emitting layers, and a plurality of second green light-emitting layers; the wavelength of light emitted by the first light-emitting layer is shorter than the wavelength of light emitted by at least one second light-emitting layer of a different color; The display substrate according to claim 1 .

3. the first light-emitting layer includes a first guest material, and a second light-emitting layer in the at least one color second light-emitting layer includes a second guest material; an emission spectrum of the first guest material at least partially overlapping with an absorption spectrum of a second guest material of at least one color of a second light-emitting layer; The display substrate according to claim 2 .

4. an overlapping range between the emission spectrum of the first guest material and the absorption spectrum of the second guest material is 60% or more of the wavelength range of the emission spectrum of the first guest material; or an overlapping range between the emission spectrum of the first guest material and the absorption spectrum of the second guest material is 60% or more of the wavelength range of the absorption spectrum of the second guest material; The display substrate according to claim 3 .

5. the emission spectrum of the first guest material has a peak value of less than 600 nm; or the first guest material has an emission spectrum with a peak value ranging from 465 nm to 475 nm, and the second guest material of the second green light-emitting layer has an absorption spectrum with a peak value ranging from 507 nm to 517 nm; or the first guest material has an emission spectrum with a peak value ranging from 525 nm to 535 nm, the second guest material of the second green light-emitting layer has an absorption spectrum with a peak value ranging from 510 nm to 520 nm, and the second guest material of the second red light-emitting layer has an absorption spectrum with a peak value ranging from 595 nm to 605 nm; The display substrate according to claim 3 .

6. the first guest material comprises at least one light-emitting material; When the first guest material comprises two light-emitting materials, the distance between the peak values ​​of the emission spectra of the two light-emitting materials is 30 nm or less; and / or the first guest material comprises at least one light-emitting material; When the first guest material contains two kinds of luminescent materials, at least one of the two luminescent materials is doped with boron, and the doping ratio of the boron element is in the range of 0.5% to 5%. The display substrate according to claim 3 .

7. the second guest material of the second light-emitting layer of at least one color comprises at least one light-emitting material; When the second guest material comprises two light-emitting materials, the distance between the peak values ​​of the emission spectra of the two light-emitting materials is 30 nm or less; and / or When the second guest material contains two kinds of luminescent materials, at least one of the two luminescent materials is doped with boron element, and the doping ratio of the boron element is in the range of 0.5% to 5%. The display substrate according to claim 3 .

8. The first guest material includes at least one material selected from the group consisting of a fluorescent material, a phosphorescent material, and a thermally activated delayed fluorescent material; and / or The second guest material includes at least one material selected from the group consisting of a fluorescent material, a phosphorescent material, and a thermally activated delayed fluorescent material having multiple resonance properties. The display substrate according to claim 7 .

9. The first light-emitting layer further comprises a first host material, and the first host material comprises a single host material or a PN mixed host material; The display substrate according to claim 3 .

10. the material of the second light-emitting layer of at least one color further comprises a second host material, and the second host material comprises a bipolar host material; The display substrate according to claim 3 .

11. the second host material comprises a single host material or a PN mixed host material; When the second host material is a PN mixed type host material, the N-type material in the PN mixed type host material has thermally activated delayed fluorescence properties. The display substrate according to claim 10.

12. the microcavity includes a plurality of sub-microcavities, the plurality of sub-microcavities including a red sub-microcavity corresponding to a second red light-emitting layer in the plurality of second red light-emitting layers, a green sub-microcavity corresponding to a second green light-emitting layer in the plurality of second green light-emitting layers, and a blue sub-microcavity corresponding to a second blue light-emitting layer in the plurality of second blue light-emitting layers; The number of film layers corresponding to the sub-microcavities of any one color located between the anode layer and the cathode layer is d, and the optical thickness of the d film layers is L, where L satisfies the following formula: [Equation 5] In the formula, d is a positive integer, n ｍ is the refractive index of the m-th film layer among the d film layers, r ｍ is the thickness of the mth film layer, k is a natural number, λ is the target spectral peak wavelength, and φ is the phase shift caused by the target light after it is reflected by the anode layer. The display substrate according to claim 2 .

13. the length of the blue sub-microcavity is less than the length of the red sub-microcavity; the length of the blue sub-microcavity is less than the length of the green sub-microcavity; The display substrate according to claim 12 .

14. the thickness range of the first light-emitting layer is 15 nm to 60 nm; and / or the thickness range of the second light-emitting layers in the plurality of second light-emitting layers of at least two different colors is 10 nm to 50 nm; The display substrate according to claim 1 .

15. the first auxiliary layer includes a light-transmitting conductive layer, a hole injection layer, a first hole transport layer, and an electron blocking layer; and / or the second auxiliary layer includes a first hole-blocking layer, a first electron-transporting layer, a first charge-generating layer, a second charge-generating layer, and a microcavity-adjusting layer; and / or the third auxiliary layer includes a second hole blocking layer, a second electron transport layer, and an electron injection layer; The display substrate according to claim 2 .

16. The microcavity adjusting layer is a second hole transport layer; a red sub-microcavity adjusting layer provided between the second hole transport layer and a second red light-emitting layer of the plurality of second red light-emitting layers; a green sub-microcavity adjusting layer provided between the second hole transport layer and a second green light-emitting layer of the plurality of second green light-emitting layers; a blue sub-microcavity adjusting layer provided between the second hole transport layer and a second blue light-emitting layer of the plurality of second blue light-emitting layers; the red sub-microcavity adjusting layer and the blue sub-microcavity adjusting layer have different lengths, and the green sub-microcavity adjusting layer and the blue sub-microcavity adjusting layer have different lengths; The display substrate according to claim 15 .

17. the red sub-microcavity adjusting layer includes a red hole transport layer and a red electron blocking layer that are sequentially stacked in a direction away from the back plate, and the green sub-microcavity adjusting layer includes a green hole transport layer and a green electron blocking layer that are sequentially stacked in a direction away from the back plate; The red hole transport layer and the green hole transport layer are used to adjust the length of the sub-microcavity of the corresponding color, respectively. The display substrate according to claim 16.

18. a backplane; an anode layer, a first auxiliary layer, a second auxiliary layer, a third auxiliary layer, and a cathode layer stacked in this order on the backplane, wherein microcavities are formed between the anode layer and the cathode layer; a first light-emitting layer provided between the first auxiliary layer and the second auxiliary layer; a plurality of second light-emitting layers of at least two different colors provided between the second auxiliary layer and the third auxiliary layer; the first auxiliary layer includes a number of film layers stacked in sequence, the second auxiliary layer includes b number of film layers stacked in sequence, and the third auxiliary layer includes c number of film layers stacked in sequence, where a, b, and c are all positive integers; The optical thicknesses of the a film layers, the b film layers, and the c film layers satisfy the following formula: [Equation 6] [Equation 7] is the average refractive index of the film layer between the anode layer and the cathode layer, [Equation 8] The range is 1.7 to 2.0, r ｈ is the thickness of the h-th film layer among the a film layers, r ｉ is the thickness of the i-th film layer among the b film layers, r ｊ is the thickness of the j-th film layer among the c film layers, Display board.

19. a backplane; an anode layer, a first auxiliary layer, a second auxiliary layer, a third auxiliary layer, and a cathode layer stacked in this order on the backplane, the second auxiliary layer including a charge generating layer, and microcavities formed between the anode layer and the cathode layer; a first light-emitting layer provided between the first auxiliary layer and the second auxiliary layer and capable of emitting light of at least two different colors; a plurality of second light-emitting layers provided between the second auxiliary layer and the third auxiliary layer, the plurality of second light-emitting layers including a plurality of second blue light-emitting layers, a plurality of second red light-emitting layers, and a plurality of second green light-emitting layers; the first auxiliary layer includes a number of film layers stacked in sequence, the second auxiliary layer includes b number of film layers stacked in sequence, and the third auxiliary layer includes c number of film layers stacked in sequence, where a, b, and c are all positive integers; The optical thicknesses of the a film layers, the b film layers, and the c film layers satisfy the following formula: [Equation 9] [Equation 10] is the average refractive index of the film layer between the anode layer and the cathode layer, [0011] The range is 1.7 to 2.0, r ｈ is the thickness of the h-th film layer among the a film layers, r ｉ is the thickness of the i-th film layer among the b film layers, r ｊ is the thickness of the j-th film layer among the c film layers, Display board.

20. A display substrate according to any one of claims 1 to 17, or A display substrate according to claim 18, or A display substrate according to claim 19, Display device.

Images