Display substrate and display device

Abstract

The embodiment of the invention provides a display substrate and a display device, and relates to the technical field of display. The display substrate comprises a substrate, an isolation structure, a first light-emitting device, a second light-emitting device and a third light-emitting device. The isolation structure is disposed on the substrate. Each of the first light-emitting device, the second light-emitting device and the third light-emitting device comprises a first electrode, a second electrode, at least two light-emitting units and at least one charge generation unit, the first electrode and the second electrode are oppositely arranged in the first direction, and the at least two light-emitting units are located between the first electrode and the second electrode. The at least one charge generation unit is positioned between two adjacent light-emitting units in the at least two light-emitting units; the size of the charge generation unit in the first direction is a first thickness, and the first thickness is larger than or equal to and smaller than or equal to the display substrate and used for displaying images.

Description

Display substrate and display device Technical Field

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

[0002] OLED (Organic Light Emitting Diode) light-emitting devices have the advantages of high efficiency and high brightness, and are widely used in display devices such as mobile phones, tablets, and televisions.

[0003] Summary of the Invention

[0004] On one hand, a display substrate is provided. The display substrate includes a substrate, an isolation structure, a first light-emitting device, a second light-emitting device, and a third light-emitting device. The isolation structure is disposed on the substrate. The first, second, and third light-emitting devices are disposed on the substrate. The first light-emitting device emits light of a first color. The second light-emitting device emits light of a second color, the wavelength of which is greater than the wavelength of the first color light. The third light-emitting device emits light of a third color, the wavelength of which is greater than the wavelength of the second color light. Each of the first, second, and third light-emitting devices includes a first electrode, a second electrode, at least two light-emitting units, and at least one charge-generating unit. The first and second electrodes are disposed opposite each other along a first direction. At least two light-emitting units are located between the first and second electrodes and are stacked along the first direction. At least one charge-generating unit is located between two adjacent light-emitting units of the at least two light-emitting units. The isolation structure is used to isolate the charge-generating units; the dimension of the charge-generating unit along the first direction is a first thickness, the first thickness being greater than or equal to... and less than or equal to

[0005] In some embodiments, the light-emitting device has a light-emitting side and a non-light-emitting side disposed opposite to each other. The second electrode is closer to the light-emitting side of the light-emitting device relative to the first electrode. At least two light-emitting units include a first light-emitting unit and a second light-emitting unit; the first light-emitting unit is closer to the first electrode relative to the second light-emitting unit. In the first light-emitting device, the first light-emitting unit includes a first light-emitting layer, and the second light-emitting unit includes a second light-emitting layer. In the second light-emitting device, the first light-emitting unit includes a third light-emitting layer, and the second light-emitting unit includes a fourth light-emitting layer. In the third light-emitting device, the first light-emitting unit includes a fifth light-emitting layer, and the second light-emitting unit includes a sixth light-emitting layer.

[0006] The first light-emitting unit further includes a first functional unit located between the first light-emitting layer and the first electrode, between the third light-emitting layer and the first electrode, or between the fifth light-emitting layer and the first electrode; the dimension of the first functional unit along the first direction is the second thickness.

[0007] The second light-emitting unit also includes a second functional unit located between the second light-emitting layer and the charge-generating unit, between the fourth light-emitting layer and the charge-generating unit, or between the sixth light-emitting layer and the charge-generating unit; the dimension of the second functional unit along the first direction is the third thickness.

[0008] In the same light-emitting device, the second thickness is greater than or equal to the third thickness.

[0009] In some embodiments, at least two of the first, third, and fifth light-emitting layers have the same dimensions along the first direction; and / or at least two of the second, fourth, and sixth light-emitting layers have the same dimensions along the first direction.

[0010] In some embodiments, the dimension of the first light-emitting layer along the first direction is smaller than the dimension of the third light-emitting layer along the first direction; the dimension of the first light-emitting layer along the first direction is smaller than the dimension of the fifth light-emitting layer along the first direction. The dimension of the third light-emitting layer along the first direction is less than or equal to the dimension of the fifth light-emitting layer along the first direction.

[0011] The dimension of the second light-emitting layer along the first direction is smaller than the dimension of the fourth light-emitting layer along the first direction. The dimension of the second light-emitting layer along the first direction is smaller than the dimension of the sixth light-emitting layer along the first direction. The dimension of the fourth light-emitting layer along the first direction is less than or equal to the dimension of the sixth light-emitting layer along the first direction.

[0012] In some embodiments, the dimension of the first light-emitting layer along the first direction is equal to the dimension of the second light-emitting layer along the first direction. And / or, the dimension of the third light-emitting layer along the first direction is equal to the dimension of the fourth light-emitting layer along the first direction. And / or, the dimension of the fifth light-emitting layer along the first direction is equal to the dimension of the sixth light-emitting layer along the first direction.

[0013] In some embodiments, the dimensions of the first light-emitting layer along the first direction range from 18 nm to 22 nm, and the dimensions of the second light-emitting layer along the first direction range from 18 nm to 22 nm. And / or, the dimensions of the third light-emitting layer along the first direction range from 30 nm to 50 nm, and the dimensions of the fourth light-emitting layer along the first direction range from 30 nm to 50 nm. And / or, the dimensions of the fifth light-emitting layer along the first direction range from 30 nm to 50 nm, and the dimensions of the sixth light-emitting layer along the first direction range from 30 nm to 50 nm.

[0014] In some embodiments, in the first light-emitting device, the ratio between the second thickness and the first thickness ranges from 4.0 to 5.0; the ratio between the third thickness and the first thickness ranges from 2.0 to 3.0.

[0015] In some embodiments, in the second light-emitting device, the ratio between the second thickness and the first thickness ranges from 5.0 to 6.0; the ratio between the third thickness and the first thickness ranges from 2.0 to 3.0.

[0016] In some embodiments, in the third light-emitting device, the ratio between the second thickness and the first thickness ranges from 7.0 to 8.0; the ratio between the third thickness and the first thickness ranges from 3.0 to 4.0.

[0017] In some embodiments, the first electrode is an anode, and the first functional unit includes multiple hole transport functional layers. The second functional unit includes multiple hole transport functional layers. The first light-emitting unit further includes a fourth functional unit located between the first light-emitting layer and the charge-generating unit, between the third light-emitting layer and the charge-generating unit, or between the fifth light-emitting layer and the charge-generating unit; the fourth functional unit includes at least one electron transport functional layer. The second light-emitting unit further includes a third functional unit located between the second light-emitting layer and the second electrode, between the fourth light-emitting layer and the second electrode, or between the sixth light-emitting layer and the second electrode; the third functional unit includes multiple electron transport functional layers. Wherein, at least one of the dimensions of the first, second, third, fourth, fifth, and sixth light-emitting layers along the first direction is smaller than the dimension of one of the multiple hole transport functional layers included in the first and second functional units along the first direction. And / or, at least one of the dimensions of the first, second, third, fourth, fifth, and sixth light-emitting layers along the first direction is smaller than the dimension of one of the multiple electron transport functional layers included in the third and fourth functional units along the first direction.

[0018] In some embodiments, the first functional unit includes a first hole transport functional layer, a second hole transport functional layer, and a third hole transport functional layer arranged in a direction away from the first electrode; the second functional unit includes a fourth hole transport functional layer and a fifth hole transport functional layer arranged in a direction away from the charge generation unit. The third functional unit includes a first electron transport functional layer, a second electron transport functional layer, and a third electron transport functional layer arranged in a direction away from the second electrode. The fourth functional unit includes a fourth electron transport functional layer and a fifth electron transport functional layer arranged in a direction close to the charge generation unit. In the first light-emitting device, the dimension of the first light-emitting layer along the first direction is smaller than the dimension of the third hole transport functional layer along the first direction; the dimension of the second light-emitting layer along the first direction is smaller than the dimension of the fifth hole transport functional layer along the first direction. And / or, in the second light-emitting device, the dimension of the third light-emitting layer along the first direction is smaller than the dimension of the second hole transport functional layer along the first direction; the dimension of the fourth light-emitting layer along the first direction is smaller than the dimension of the fourth hole transport functional layer along the first direction. And / or, in the third light-emitting device, the dimension of the fifth light-emitting layer along the first direction is smaller than the dimension of the fifth electron transport functional layer along the first direction; the dimension of the sixth light-emitting layer along the first direction is smaller than the dimension of the second electron transport functional layer along the first direction.

[0019] In some embodiments, the charge generating unit includes a first charge generating layer and a second charge generating layer stacked along a first direction, wherein the first charge generating layer is closer to the first electrode than the second charge generating layer; the second charge generating layer has a fourth thickness along the first direction. In the first light-emitting device, the ratio between the second thickness and the sum of the third and fourth thicknesses ranges from 1.0 to 2.0. And / or, in the second light-emitting device, the ratio between the second thickness and the sum of the third and fourth thicknesses ranges from 1.0 to 2.0. And / or, in the third light-emitting device, the ratio between the second thickness and the sum of the third and fourth thicknesses ranges from 1.0 to 3.0.

[0020] In some embodiments, in the second light-emitting device, the second thickness is greater than the sum of the third and fourth thicknesses. A first difference exists between the second thickness and the sum of the third and fourth thicknesses; the ratio of this first difference to the wavelength of the second color light ranges from 0.1 to 0.2. And / or, in the third light-emitting device, the second thickness is greater than the sum of the third and fourth thicknesses. A second difference exists between the second thickness and the sum of the third and fourth thicknesses; the ratio of this second difference to the wavelength of the third color light ranges from 0.1 to 0.2.

[0021] In some embodiments, the charge generating unit includes a first charge generating layer and a second charge generating layer stacked along a first direction; the first charge generating layer is closer to the first electrode than the second charge generating layer; the second charge generating layer has a fourth thickness along the first direction. The sum of the second thicknesses corresponding to the first light-emitting device, the second light-emitting device, and the third light-emitting device is a sixth thickness; the sum of the third thicknesses corresponding to the first light-emitting device, the second light-emitting device, and the third light-emitting device is a seventh thickness; the sum of the fourth thicknesses corresponding to the first light-emitting device, the second light-emitting device, and the third light-emitting device is an eighth thickness; the ratio between the sixth thickness and the sum of the seventh thickness and the eighth thickness ranges from 1.0 to 2.0.

[0022] In some embodiments, the charge generating unit includes a first charge generating layer and a second charge generating layer stacked along a first direction, wherein the first charge generating layer is closer to the first electrode than the second charge generating layer. The first charge generating layer has a fifth thickness along the first direction, and the fifth thickness ranges from... The second charge-generating layer has a fourth thickness along the first direction; the range of the fourth thickness is within...

[0023] In some embodiments, the charge generating unit includes a first charge generating layer and a second charge generating layer stacked along a first direction, wherein the first charge generating layer is closer to the first electrode than the second charge generating layer. The first charge generating layer has a fifth thickness along the first direction, and the fifth thickness ranges from... The second charge-generating layer has a fourth thickness along the first direction; the range of the fourth thickness is within...

[0024] In some embodiments, the ratio between the distance between the surface of the selected light-emitting layer away from the first electrode and the surface of the first electrode close to the selected light-emitting layer, and the wavelength of the selected color light is greater than or equal to (4n+1) / 8 and less than or equal to (4n+3) / 8; n is 0 or a positive integer; wherein the selected light-emitting layer is any one of the first light-emitting layer, the second light-emitting layer, the third light-emitting layer, the fourth light-emitting layer, the fifth light-emitting layer, and the sixth light-emitting layer; the selected color light is the light corresponding to the selected light-emitting layer among the first color light, the second color light, and the third color light.

[0025] In some embodiments, the first electrode is an anode; the first functional unit includes a first hole transport functional layer, a second hole transport functional layer, and a third hole transport functional layer arranged in a direction away from the first electrode; the second functional unit includes a fourth hole transport functional layer and a fifth hole transport functional layer arranged in a direction away from the charge generation unit.

[0026] In some embodiments, in the second light-emitting device, there is a first distance between the third hole transport functional layer and the charge generation unit; the sum of the dimension of the third hole transport functional layer along the first direction and the first distance is less than or equal to the sum of the dimensions of the first hole transport functional layer and the second hole transport functional layer along the first direction.

[0027] In some embodiments, in the first light-emitting device, the size of the third hole transport functional layer along the first direction ranges from 5 nm to 10 nm; the size of the fifth hole transport functional layer along the first direction ranges from 5 nm to 10 nm. And / or, in the second light-emitting device, the size of the third hole transport functional layer along the first direction ranges from 40 nm to 45 nm; the size of the fifth hole transport functional layer along the first direction ranges from 15 nm to 20 nm. And / or, in the third light-emitting device, the size of the third hole transport functional layer along the first direction ranges from 80 nm to 95 nm; the size of the fifth hole transport functional layer along the first direction ranges from 25 nm to 35 nm.

[0028] In some embodiments, the size of the first hole transport functional layer along the first direction ranges from 5 nm to 15 nm. And / or, the size of the second hole transport functional layer along the first direction ranges from 95 nm to 105 nm. And / or, the size of the fourth hole transport functional layer along the first direction ranges from 50 nm to 60 nm.

[0029] In some embodiments, the material of the selected light-emitting layer includes a host material and a guest material; the doping ratio of the guest material in the material of the selected light-emitting layer is greater than 0 and less than or equal to 10%; wherein, the selected light-emitting layer is any one of the first light-emitting layer, the second light-emitting layer, the third light-emitting layer, the fourth light-emitting layer, the fifth light-emitting layer, and the sixth light-emitting layer; the guest materials contained in any two of the first light-emitting layer, the second light-emitting layer, the third light-emitting layer, the fourth light-emitting layer, the fifth light-emitting layer, and the sixth light-emitting layer may be the same or different.

[0030] In some embodiments, the doping ratio of the guest material in the fifth light-emitting layer is less than or equal to the doping ratio of the guest material in the third light-emitting layer, and less than or equal to the doping ratio of the guest material in the fourth light-emitting layer. Similarly, the doping ratio of the guest material in the sixth light-emitting layer is less than or equal to the doping ratio of the guest material in the third light-emitting layer, and less than or equal to the doping ratio of the guest material in the fourth light-emitting layer.

[0031] In some embodiments, the charge generation unit includes a first charge generation layer and a second charge generation layer stacked along a first direction, wherein the first charge generation layer is closer to the first electrode than the second charge generation layer; the material of the first charge generation layer includes a first matrix material and an N-type dopant. The material of the second charge generation layer includes a second matrix material and a P-type dopant. The ratio between the doping ratio of the N-type dopant in the material of the first charge generation layer and the doping ratio of the P-type dopant in the material of the second charge generation layer is greater than or equal to 0.01 and less than or equal to 0.2.

[0032] In some embodiments, the doping ratio of N-type dopant in the material of the first charge generation layer is greater than or equal to 0 and less than or equal to 5%. And / or, the doping ratio of P-type dopant in the material of the second charge generation layer is greater than or equal to 0 and less than or equal to 20%.

[0033] In some embodiments, the wavelength of the first color light is greater than or equal to 400 nm and less than or equal to 500 nm. The wavelength of the second color light is greater than or equal to 510 nm and less than or equal to 540 nm. The wavelength of the third color light is greater than or equal to 600 nm.

[0034] In another aspect, a display device is provided, including a driver chip and a display substrate as described in any of the above embodiments. The driver chip is used to drive the display substrate to perform display. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in this disclosure, the accompanying drawings used in some embodiments of this disclosure will be briefly described below. Obviously, the drawings described below are only drawings of some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings. In addition, the drawings described below can be regarded as schematic diagrams and are not intended to limit the actual size of the product, the actual flow of the method, the actual timing of the signals, etc. involved in the embodiments of this disclosure.

[0036] Figure 1 is a structural diagram of a display device according to some embodiments;

[0037] Figure 2 is a structural diagram of a display substrate according to some embodiments;

[0038] Figure 3 is a structural diagram of a display substrate according to some other embodiments;

[0039] Figure 4 is a structural diagram of a display substrate according to some other embodiments;

[0040] Figure 5 is a structural diagram of a display substrate according to some other embodiments;

[0041] Figure 6 is a structural diagram of a first light-emitting device according to some embodiments;

[0042] Figure 7A is a structural diagram of a display substrate according to some other embodiments;

[0043] Figure 7B is a structural diagram of a display substrate according to some other embodiments;

[0044] Figure 8 is a structural diagram of a first light-emitting device according to some other embodiments;

[0045] Figure 9 is a structural diagram of a second light-emitting device according to some embodiments;

[0046] Figure 10 is a structural diagram of a third light-emitting device according to some embodiments;

[0047] Figure 11 is a structural diagram of a display substrate according to some other embodiments;

[0048] Figure 12 is a structural diagram of a display substrate according to some other embodiments;

[0049] Figure 13 is a structural diagram of a first light-emitting device according to some other embodiments;

[0050] Figure 14 is a structural diagram of a second light-emitting device according to some other embodiments;

[0051] Figure 15 is a structural diagram of a third light-emitting device according to some other embodiments. Detailed Implementation

[0052] The technical solutions in some embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments provided in this disclosure are within the scope of protection of this disclosure.

[0053] Unless the context otherwise requires, throughout the specification and claims, the term "comprise" and its other forms, such as the third-person singular "comprises" and the present participle "comprising," are interpreted as open-ended and encompassing, meaning "including, but not limited to." In the description of the specification, terms such as "one embodiment," "some embodiments," "exemplary embodiments," "example," "specific example," or "some examples," etc., are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this disclosure. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics mentioned may be included in any suitable manner in any one or more embodiments or examples.

[0054] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this disclosure, unless otherwise stated, "a plurality of" means two or more.

[0055] "At least one of A, B and C" has the same meaning as "at least one of A, B or C", both including the following combinations of A, B and C: only A, only B, only C, combinations of A and B, combinations of A and C, combinations of B and C, and combinations of A, B and C.

[0056] "A and / or B" includes the following three combinations: A only, B only, and a combination of A and B.

[0057] As used herein, depending on the context, the term “if” is optionally interpreted as meaning “when” or “at the time of”. Similarly, depending on the context, the phrase “if it is determined that…” is optionally interpreted as meaning “when it is determined that…”.

[0058] The use of “applies to” or “configured to” in this article implies an open and inclusive language that does not preclude applicability to or configuration to devices that perform additional tasks or steps.

[0059] In addition, the use of “based on” implies openness and inclusivity, because processes, steps, calculations or other actions “based on” one or more of the stated conditions or values ​​may in practice be based on additional conditions or values ​​beyond those stated.

[0060] As used herein, “about,” “approximately,” or “approximately” includes the stated value and the average value within an acceptable range of deviation from the given value, wherein the acceptable range of deviation is determined by a person skilled in the art taking into account the measurement under discussion and the error associated with the measurement of the given quantity (i.e., the limitations of the measurement system).

[0061] As used herein, “parallel,” “perpendicular,” and “equal” include the described situation and situations that are similar to the described situation, within an acceptable range of deviation, which is determined by those skilled in the art taking into account the measurement under discussion and the error associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, “parallel” includes absolute parallelism and approximate parallelism, where an acceptable range of deviation for approximate parallelism may be, for example, within 5°; “perpendicular” includes absolute perpendicularity and approximate perpendicularity, where an acceptable range of deviation for approximate perpendicularity may also be, for example, within 5°; “equal” includes absolute equality and approximate equality, where an acceptable range of deviation for approximate equality may be, for example, a difference between the two equals being less than or equal to 5% of either one.

[0062] It should be understood that when a layer or element is referred to as being on another layer or substrate, it can mean that the layer or element is directly on the other layer or substrate, or that there is an intermediate layer between the layer or element and the other layer or substrate.

[0063] This document describes exemplary embodiments with reference to cross-sectional views and / or plan views, which are idealized exemplary drawings. In the drawings, the thickness of layers and the area of ​​regions are enlarged for clarity. Therefore, variations in shape relative to the drawings are contemplated due to, for example, manufacturing techniques and / or tolerances. Thus, exemplary embodiments should not be construed as being limited to the shapes of the regions shown herein, but rather include shape deviations due to, for example, manufacturing processes. For example, etched areas shown as rectangular would typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to show the actual shapes of the areas of the device, nor are they intended to limit the scope of the exemplary embodiments.

[0064] It should be noted that, for example, 11-1 in the accompanying drawings of this disclosure indicates that component 11 belongs to component 1; for example, 221-220 in Figure 3 indicates that pixel defining layer 221 belongs to light-emitting functional layer 220; other similar reference numerals in the drawings also follow the above description. For example, 1 / 2 in the accompanying drawings of this disclosure indicates that both component 1 and component 2 can refer to this component; for example, 101 / 100 in Figure 3 indicates that both first light-emitting device 101 and light-emitting device 100 can be represented by this component. Other similar reference numerals in the accompanying drawings also follow the above description.

[0065] As shown in FIG1, some embodiments of the present disclosure provide a display device 300, which includes a display substrate 200.

[0066] The aforementioned display device 300 can be an OLED display device. OLED display devices are a new type of flat panel display device. Firstly, compared to liquid crystal displays (LCDs), OLED display devices offer better viewing angles and contrast. Secondly, because OLEDs are self-emissive, they do not require a separate backlight, allowing for lighter and thinner designs. Thirdly, OLEDs exhibit superior power consumption compared to LCDs and other flat panel display devices. Fourthly, OLEDs can be driven with low direct current (DC) voltages, offering a fast response time. Fifthly, OLEDs also boast low manufacturing costs. In the field of organic semiconductors, OLED technology has received increasing attention from academia and industry and has been successfully applied in commercial flat panel displays and lighting industries.

[0067] For example, as shown in FIG1, the display device 300 further includes a driver chip 310, which is used to drive the display substrate 200 to display.

[0068] In addition, the display device 300 may also include an under-display camera and an under-display fingerprint sensor, enabling the display device 300 to perform various functions such as taking photos, recording videos, fingerprint recognition, or facial recognition.

[0069] The aforementioned display device 300 can be a device used to display information such as images, text, and video, such as electronic products, communication equipment, billboards, monitoring systems, etc., but is not limited thereto. The aforementioned display device can be any display device that displays either moving (e.g., video) or fixed (e.g., still images) text or images. More specifically, the display device of the described embodiments is intended to be implemented in or associated with a variety of electronic devices, such as (but not limited to) mobile phones, wireless devices, personal data assistants (PDAs), handheld or portable computers, GPS receivers / navigators, cameras, MP4 video players, camcorders, game consoles, watches, clocks, calculators, television monitors, flat panel displays, computer monitors, automotive displays (e.g., odometer displays, etc.), navigators, cockpit controllers and / or displays, displays of camera views (e.g., displays of rearview cameras in vehicles), electronic photographs, electronic billboards or signs, projectors, architectural structures, packaging and aesthetic structures (e.g., displays of images of a piece of jewelry), etc.

[0070] In some embodiments, as shown in FIG2, the display substrate 200 includes a substrate 210 and a light-emitting functional layer 220 disposed on the substrate 210, the light-emitting functional layer 220 including a plurality of light-emitting devices 100.

[0071] For example, a plurality of light-emitting devices 100 may be arranged along a second direction Y, which is, for example, a direction parallel to the plane where the substrate 210 is located.

[0072] In some examples, as shown in Figures 2 and 3, the substrate 210 can be made of any transparent rigid material, such as glass, to achieve a rigid substrate display; or, it can be made of any transparent flexible material, such as polyimide, to achieve a flexible substrate display.

[0073] In some examples, depending on whether TFT technology is used in the pixel driving circuit 231, the OLED display substrate can be divided into an active-matrix OLED (AMOLED) display substrate using TFT technology (as shown in Figure 2) and a passive-matrix OLED (PMOLED) display substrate not using TFT technology. That is, the driving types of active-matrix OLED display substrates and passive-matrix OLED display substrates are different.

[0074] In some examples, the AMOLED display substrate has a TFT array. A pixel driving circuit 231 formed by the TFTs transfers a positive charge (+) to the anode 11 of the light-emitting device 100 and a negative charge (-) to the cathode 12 of the light-emitting device 100, creating an electric field between the anode 11 and the cathode 12. Since each light-emitting device 100 is independently controlled by a pixel driving circuit, each light-emitting device 100 of the AMOLED display substrate emits light independently. Based on this, the emission of each light-emitting device 100 can be independently controlled, allowing the light-emitting devices 100 to emit light continuously and independently, ultimately forming the desired image.

[0075] In some examples, the PMOLED display substrate does not include a TFT array, but instead comprises intersecting strips of cathode and anode, with the intersections of the rows and columns capable of emitting light. The PMOLED display substrate illuminates the sub-pixels in the array in a scanning manner.

[0076] In some examples, as shown in FIG2, the display substrate 200 further includes an array layer 230 disposed between the substrate 210 and the light-emitting functional layer 220. The array layer 230 includes a plurality of pixel driving circuits 231, wherein the pixel driving circuit 231 includes, for example, a plurality of transistor TFTs and capacitors, and the plurality of transistor TFTs includes, for example, a switching TFT and a driving TFT. The driving TFT of each pixel driving circuit 231 is electrically connected to a light-emitting device 100 for driving the light-emitting device 100 to emit light. Based on this, scanning signals, data signals and power can be supplied to the plurality of pixel driving circuits 231 arranged in a matrix type, and the selected light-emitting device 100 emits light to display an image.

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

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

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

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

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

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

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

[0084] It should be noted that Figures 4 to 10 are simplified schematic diagrams obtained after removing the film layers other than the film layers related to the light-emitting device 100 from the display substrate 200.

[0085] In some embodiments, as shown in Figures 2 to 6, the light-emitting device 100 includes an anode 11 and a cathode 12 disposed opposite to each other along a first direction X, and at least one light-emitting unit 13 disposed between the anode 11 and the cathode 12. The light-emitting unit 13 includes a light-emitting layer 131.

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

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

[0088] In some examples, based on the direction of light emission, OLED display substrates can be classified into top-emitting display substrates (also known as top-emitting display substrates), bottom-emitting display substrates (also known as bottom-emitting display substrates), and double-sided emitting display substrates (also known as dual-emitting display substrates).

[0089] In the bottom-emitting display substrate, the light emitted by the light-emitting layer 131 is emitted from the substrate 210 side. At this time, the anode 11 and the cathode 12, which are relatively closer to the substrate 210, can be a light-transmitting electrode (such as a transparent electrode or a semi-transparent electrode), and the one that is relatively farther away from the substrate 210 can be an opaque electrode; for example, an opaque reflective electrode.

[0090] In a top-emitting display substrate, the light emitted from the light-emitting layer 131 exits from the side furthest from the substrate 210. Since the light needs to exit from the side furthest from the substrate 210, the anode 11 and cathode 12, the one closer to the substrate 210, can be an opaque electrode, such as an opaque reflective electrode, while the one furthest from the substrate 210 can be a transparent or semi-transparent electrode. Understandably, in a bottom-emitting display substrate, light passes through the substrate 210, causing it to be blocked by the pixel driving circuit 231 on the substrate 210. Therefore, compared to a bottom-emitting display substrate, the pixel defining layer 221 in a top-emitting display substrate has a relatively higher aperture ratio and a relatively higher light transmittance.

[0091] In some examples, the light-emitting region (e.g., the region where the light-emitting layer 131 is located) of the light-emitting device 100 of the top-emitting OLED display substrate 200 is located in a resonant cavity composed of a total reflection film (one of the anode 11 and cathode 12) and a semi-reflective film (the other of the anode 11 and cathode 12). When the cavity length (the distance between the anode 11 and cathode 12) is on the same order of magnitude as the wavelength of the light wave, the light emitted by the light-emitting layer 131 can be reflected multiple times between the anode 11 and cathode 12, so that light of a specific wavelength is selected and enhanced, and the spectrum is narrowed, which is called the microcavity effect. Compared with the light-emitting device without the microcavity effect, the light-emitting device with the microcavity effect can make some of the light that cannot be emitted change the emission angle and then be emitted, thereby achieving the purpose of improving the vertical light emission efficiency. Therefore, in the top-emitting OLED display substrate 200, the design of the cavity length of the microcavity is particularly important in order to enhance the microcavity effect of the light-emitting device 100.

[0092] The double-sided emitting display substrate 200 allows light emitted from its light-emitting layer to exit from both the side away from the substrate 210 and the side of the substrate 210, enabling the display substrate to display from both sides. Since the light needs to exit in two directions, both the anode 11 and the cathode 12 must be configured as light-transmitting electrodes.

[0093] For example, to ensure that the light-emitting device 100 can emit light effectively, the anode 11 can be made of a material with a high work function. This allows holes in the anode 11 to migrate effectively to the light-emitting layer 131 of the light-emitting unit 13 under the drive of the electric field, thereby recombineing with electrons from the cathode 12 to emit light. The material of the anode 11 can be a transparent conductive metal oxide material, such as indium tin oxide (ITO) or indium zinc oxide (IZO). Alternatively, the anode 11 can be a composite electrode containing multiple materials, such as ITO / Ag / ITO, Ag / IZO, CNT / ITO, CNT / IZO, GO / ITO, or GO / IZO, where Ag is silver, CNT is carbon nanotube, and GO is graphene oxide.

[0094] In some examples, the cathode 12 can be made of a material with a low work function, which makes it easier for electrons from the cathode 12 to be injected into the target film layer (e.g., the electron injection layer 1331 described in detail below). This allows electrons in the cathode 12 to migrate effectively to the light-emitting layer 131 of the light-emitting unit 13 under the drive of the electric field, thereby recombinating with holes in the anode 11 to emit light. Furthermore, the cathode 12 must also have good light transmittance and conductivity. The material of the cathode 12 can be a metal, metal oxide, or metal alloy, such as aluminum (Al), silver (Ag), gold (Au), magnesium (Mg), calcium (Ca), ytterbium (Yb), indium (In), lithium (Li), potassium (K), sodium (Na), tin (Sn), titanium (Ti), lead (Pb), samarium (Sm), yttrium (Y), indium tin oxide (ITO), magnesium-silver alloy (Mg:Ag), ytterbium-gold alloy (Yb:Au), and ytterbium-silver alloy. The cathode 12 can be made of materials such as (Yb:Ag), lithium aluminum alloy (Li:Al), or lithium calcium magnesium alloy (Li:Ca:Al); or, the cathode 12 can be made of a multilayer material, such as magnesium / aluminum (Mg / Al), magnesium / silver (Mg / Ag), aluminum / silver (Al / Ag), aluminum / gold (Al / Au), ytterbium / gold (Yb / Au), ytterbium / silver (Yb / Ag), calcium / magnesium (Ca / Mg), calcium / silver (Ca / Ag), barium / silver (Ba / Ag), etc.

[0095] In some embodiments, the light-emitting device 100 further includes a cover layer CPL (refer to Figure 12, also known as a light extraction layer). The cover layer CPL can be in contact with the cathode 12. The cover layer CPL can be made of organic small molecule materials. By setting the cover layer CPL, the refractive index can be adjusted. For example, the high refractive properties of the cover layer CPL material can be used to improve the light extraction efficiency of the light-emitting device 100, thereby improving the efficiency and brightness of the light-emitting device 100 when lit.

[0096] For example, the thickness of the cover layer CPL can be 50nm to 80nm, such as 50nm, 56nm, 62nm, 68nm, 74nm or 80nm.

[0097] For example, the material of the capping layer CPL has a refractive index greater than 1.8 at a wavelength of 460 nm, such as 1.9, 2.3, 2.5, 2.7, 2.9, etc.

[0098] In some examples, as shown in Figures 2-4, the light-emitting device 100 includes a single light-emitting unit 13. In this case, the light-emitting device 100 is a single-layer light-emitting device, with the anode 11, the light-emitting unit 13, and the cathode 12 stacked along a first direction X, which intersects with a second direction Y. In other examples, as shown in Figures 5 and 6, the light-emitting device 100 includes multiple (e.g., two) stacked light-emitting units 13. In this case, the light-emitting device 100 is a multilayer light-emitting device, with the anode 11, multiple light-emitting units 13, and the cathode 12 stacked along the first direction X. Here, when the multilayer light-emitting device is an OLED light-emitting device, it can also be called a tandem organic electroluminescent (TANDEM) light-emitting device.

[0099] For example, as shown in Figures 2 to 6, the second direction Y is set perpendicular to the first direction X.

[0100] In some embodiments, as shown in FIG5 and FIG6, when the light-emitting device 100 includes a plurality of light-emitting units 13, that is, when the light-emitting device 100 includes at least two light-emitting units 13, the light-emitting device 100 further includes a charge-generating unit 14, which is located between two adjacent light-emitting units 13 among the plurality of light-emitting units 13.

[0101] In some examples, as shown in Figures 5 and 6, the charge generation unit 14 includes a stacked electron generation layer 141 and a hole generation layer 142; the electron generation layer 141 is closer to the anode 11 than the hole generation layer 142. The electron generation layer 141 can also be referred to as an N-type charge generation layer NCGL, and the hole generation layer 142 can also be referred to as a P-type charge generation layer PCGL. Exemplarily, the N-type charge generation layer NCGL and the P-type charge generation layer PCGL can be in contact to form a PN junction charge generation unit 14.

[0102] Through the charge generating unit 14 described above, multiple light-emitting units 13 can be connected sequentially in the vertical direction (e.g., the first direction X) of the light-emitting surface. Furthermore, the charge generation unit 14 in the stacked OLED light-emitting device 100 not only serves to connect the light-emitting units 13, but also generates charges and / or separates holes and electrons. In this way, charges (holes or electrons) can be injected into the adjacent light-emitting units 13. For example, as shown in Figures 5 and 6, the electron generation layer 141 can supply electrons to the light-emitting layers of the light-emitting units adjacent to the anode 11 (e.g., the red light-emitting layer 131R, green light-emitting layer 131G, and blue light-emitting layer 131B located on the lower side in the figure); the hole generation layer 142 can supply holes to the light-emitting layers of the light-emitting units adjacent to the cathode 12 (e.g., the red light-emitting layer 131R, green light-emitting layer 131G, and blue light-emitting layer 131B located on the upper side in the figure). In this way, firstly, it is beneficial to improve the charge (holes or electrons) generation efficiency, which can improve the luminous efficiency of the light-emitting device 100; secondly, it can reduce the driving voltage of the light-emitting device 100. Therefore, the charge generation unit 14 can have a significant impact on the performance of the light-emitting device 100.

[0103] In some embodiments, as shown in Figures 3 to 6, to improve the luminous efficiency of the light-emitting device 100, the light-emitting unit 13 further includes a hole transport unit 132, located on the side of the light-emitting layer 131 near the anode 11 and in contact with the light-emitting layer 131. The hole transport unit 132 includes, for example, at least one of a stacked hole injection layer 1321 (HIL), a hole transport layer 1322 (HTL), and an electron blocking layer 1323 (EBL). When the hole transport unit 132 includes a hole injection layer 1321, a hole transport layer 1322, and an electron blocking layer 1323, the hole injection layer 1321, the hole transport layer 1322, and the electron blocking layer 1323 are arranged sequentially in a direction away from the anode 11, and the electron blocking layer 1323 is in contact with the light-emitting layer 131.

[0104] In some embodiments, as shown in Figures 3 to 6, to improve the luminous efficiency of the light-emitting device 100, the light-emitting unit 13 further includes an electron transport unit 133, located on the side of the light-emitting layer 131 near the cathode 12 and in contact with the light-emitting layer 131. The electron transport unit 133 includes, for example, at least one of a stacked electron injection layer 1331 (EIL), an electron transport layer 1332 (ETL), and a hole blocking layer 1333 (EBL). When the electron transport unit 133 includes an electron injection layer 1331, an electron transport layer 1332, and a hole blocking layer 1333, the electron injection layer 1331, the electron transport layer 1332, and the hole blocking layer 1333 are arranged sequentially in a direction away from the cathode 12, and the hole blocking layer 1333 is in contact with the light-emitting layer 131.

[0105] By setting up the hole injection layer 1321, hole transport layer 1322, electron blocking layer 1323, electron injection layer 1331, electron transport layer 1332, and hole blocking layer 1333, it is equivalent to setting up transition steps between the anode 11 and the light-emitting layer 131, and between the cathode 12 and the light-emitting layer 131, reducing the potential barrier height that carrier transitions need to overcome, and thus making the luminous efficiency higher.

[0106] Exemplarily, hole transport unit 132 can be configured to transport holes and / or block electrons and excitons generated within the light-emitting layer 131. For example, hole injection layer 1321 can be configured to reduce the hole injection barrier and improve hole injection efficiency. Hole transport layer 1322 can be configured to transport holes. Electron blocking layer 1323 can be configured to transport holes, block electrons, and block excitons generated within the light-emitting layer 131; for example, electron blocking layer 1323 can confine excitons within the light-emitting layer 131, preventing exciton leakage to both sides of the light-emitting layer 131 and causing efficiency loss. In some examples, the energy levels of the material of electron blocking layer 1323 are within a certain range, so that electron blocking layer 1323 can avoid overtransmission of electrons and distribute exciton recombination regions within the light-emitting layer 131.

[0107] Exemplarily, the electron transport unit 133 can be configured to transport electrons and / or block holes and excitons generated within the light-emitting layer 131. In some examples, the energy levels of the material of the hole blocking layer 1333 are within a certain range, so that the hole blocking layer 1333 can prevent overtransmission of holes and distribute the exciton recombination region within the light-emitting layer 131.

[0108] For example, as shown in Figure 4, when the light-emitting device 100 is a single-layer light-emitting device, the light-emitting device 100 may include: an anode 11, a hole injection layer 1321, a hole transport layer 1322, an electron blocking layer 1323, a light-emitting layer 131, a hole blocking layer 1333, an electron transport layer 1332, an electron injection layer 1331, and a cathode 12. Under the action of the driving voltage, electrons are generated by the cathode 12, injected through the electron injection layer 1331, and transported to the light-emitting layer 131 through the electron transport layer 1332 and the hole blocking layer 1333. Holes are generated by the anode 11, injected through the hole injection layer 1321, and transported to the light-emitting layer 131 through the hole transport layer 1322 and the electron blocking layer 1323. Electrons and holes recombine in the light-emitting layer and generate singlet excitons and triplet excitons with a probability of 25:75. By including multiple structural layers in the light-emitting device 100, the matching effect between different functional layers (such as carrier mobility, energy level, interface, energy transfer, etc.) can be taken into account, thereby improving the device performance.

[0109] For example, the material of the hole injection layer 1321 can be an inorganic metal oxide, such as molybdenum oxide, titanium oxide, vanadium oxide, rhenium oxide, ruthenium oxide, chromium oxide, zirconium oxide, hafnium oxide, tantalum oxide, silver oxide, tungsten oxide, manganese oxide, etc.; or, the hole injection layer 1321 can also be a dopant of a strong electron-withdrawing system, such as tetrafluorotetracyanoquinolinequinone dimethyl ether (F4TCNQ), hexaazaheptaphenyltriphenylhexanitrile (HATCN), etc.; or, the hole injection layer 1321 can also be obtained by p-type doping of the hole transport material (e.g., by co-evaporation to form the hole injection layer). For example, the thickness of the hole injection layer 1321 can be 5 nm to 20 nm, such as 5 nm, 10 nm, 15 nm, 18 nm, or 20 nm.

[0110] For example, the hole transport layer 1322 has good hole transport characteristics, and its material can be an aromatic amine or carbazole material, such as N,N'-di(1-naphthyl)-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (NPB), N,N'-di(naphthyl)-N,N'-diphenylphenyldiamine (TPD), bis(2-(2-hydroxyphenyl)benzoxazole) (BAFLP) or 2,8-difluoro-5,11-bis(tri-tert-butylsilylethynyl)benzo[3,8]phenanthroline (DFLDPBi), etc.

[0111] For example, the electron blocking layer 1323 (also known as the prime layer or light-emitting auxiliary layer) has good hole transport characteristics. The material of the electron blocking layer 1323 can be an aromatic amine material or a carbazole material, such as biphenylbenzoxazole (CBP), polycarbazole phthaloline (PCzPA), etc.

[0112] Exemplarily, the materials of the hole blocking layer 1333 and the electron transport layer 1332 can be aromatic heterocyclic compounds, such as imidazole derivatives, pyrimidine derivatives, azine derivatives, compounds containing a nitrogen-containing six-membered ring structure, or compounds containing phosphine oxide substituents on the heterocycle. Imidazole derivatives include, for example, benzimidazole derivatives, imidazopyridine derivatives, or benzimidazolephenanthridine derivatives; azine derivatives include, for example, triazine derivatives; and compounds containing a nitrogen-containing six-membered ring structure include, for example, quinoline derivatives, isoquinoline derivatives, or phenanthreneroline derivatives. The materials of the hole blocking layer 1333 and the electron transport layer 1332 can be, for example, oxadiazole-7 (OXD-7), 1,3,4-thiadiazole (TAZ), p-ethyltrithiophene (p-EtTAZ), 2,9-diphenyl-1,10-phenanthroline (BPhen), or 2,9-diphenyl-4,7-dinitro-1,10-phenanthroline (BCP).

[0113] For example, the material of the electron injection layer 1331 can be a material with the ability to transport electrons, having the effect of injecting electrons from the cathode 12, and having excellent thin film forming ability. It is generally an alkali metal or a metal, such as lithium fluoride (LiF), ytterbium (Yb), magnesium (Mg), calcium (Ca) or a compound of ytterbium (Yb), magnesium (Mg), calcium (Ca).

[0114] In some embodiments, as shown in Figures 2, 3, and 5, when the plurality of light-emitting devices 100 include a first light-emitting device 101, a second light-emitting device 102, and a third light-emitting device 103, the cathodes 12 of the plurality of light-emitting devices 100 are in a fully interconnected structure, that is, the cathodes 12 can be a common electrode shared by the plurality of light-emitting devices 100. The hole injection layer 1321 of the plurality of light-emitting devices 100 can also be in a fully interconnected structure, that is, the hole injection layer 1321 can be a common film layer shared by the plurality of light-emitting devices 100. The hole transport layer 1322, the electron blocking layer 1323, the electron injection layer 1331, the electron transport layer 1332, the hole blocking layer 1333, the electron generation layer 141, and the hole generation layer 142 can also be common film layers shared by the plurality of light-emitting devices 100, which will not be described in detail here.

[0115] For example, as shown in FIG3, when the cathode 12 is a common electrode shared by multiple light-emitting devices 100, the cathode 12 is simultaneously formed on the side of the pixel defining layer 221 away from the substrate 210.

[0116] In some embodiments, as shown in Figures 3 to 5, when multiple light-emitting devices 100 include a first light-emitting device 101, a second light-emitting device 102, and a third light-emitting device 103, the electron blocking layers 1323 of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 are independently disposed; that is, the electron blocking layer 1323 may include a blue electron blocking layer 1323B (also referred to as a blue light-emitting auxiliary layer), a green electron blocking layer 1323G (also referred to as a green light-emitting auxiliary layer), and a red electron blocking layer 1323R (also referred to as a red light-emitting auxiliary layer). With this arrangement, the material of the electron blocking layer 1323 with matching performance can be selected as needed according to the different materials of the light-emitting layer 131.

[0117] For example, when the light-emitting device 100 is a stacked light-emitting device (e.g., containing two light-emitting units 13), the structure of the light-emitting device 100 (e.g., the first light-emitting device 101) is as shown in FIG. 6. The light-emitting device 100 includes a stacked anode 11, hole transport unit 132, light-emitting layer 131, electron transport unit 133, electron generation layer 141, hole generation layer 142, hole transport unit 132, light-emitting layer 131, electron transport unit 133, and cathode 12. Among them, the hole transport unit 132, light-emitting layer 131, and electron transport unit 133 located near the anode 11 constitute the first light-emitting unit 13, and the hole transport unit 132, light-emitting layer 131, and electron transport unit 133 located near the cathode 12 constitute the second light-emitting unit 13.

[0118] For example, when the light-emitting device 100 is a stacked light-emitting device (e.g., containing two light-emitting units 13), and the multiple light-emitting devices 100 include a first light-emitting device 101, a second light-emitting device 102, and a third light-emitting device 103, the structure of the display substrate 200 is as shown in FIG. 5, for example, the cathode 12 is the common electrode of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103; the other film layers in the hole transport functional layer 132 of the first light-emitting unit 13 and the second light-emitting unit 13, except for the electron blocking layer 1323, and each film layer in the electron transport unit 133 of the first light-emitting unit 13 and the second light-emitting unit 13 are common film layers shared by the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103. The anodes 11 of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103, the electron blocking layer 1323 and the light-emitting layer 131 of the first light-emitting unit 13, and the electron blocking layer 1323 and the light-emitting layer 131 of the second light-emitting unit 13 are independently disposed. For details on the method of independent disposal, please refer to the above content; it will not be repeated here.

[0119] For example, in the above-described stacked light-emitting device, as shown in FIG5, the hole transport unit 132 of the first light-emitting unit 13 closer to the anode 11 may include a hole injection layer 1321, a hole transport layer 1322, and an electron blocking layer 1323. The hole transport unit 132 of the second light-emitting unit 13 closer to the cathode 12 may include a hole transport layer 1322 and an electron blocking layer 1323.

[0120] For example, in the above-described stacked light-emitting device, as shown in Figures 5 and 6, the electron transport unit 133 of the first light-emitting unit 13 closer to the anode 11 may include a hole blocking layer 1333 and an electron transport layer 1332. The electron transport unit 133 of the second light-emitting unit 13 closer to the cathode 12 may include a hole blocking layer 1333, an electron transport layer 1332, and an electron injection layer 1331.

[0121] In the above-mentioned stacked light-emitting device containing two light-emitting units 13, the electron generating layer 141 can inject electrons into the first light-emitting unit 13, and the hole generating layer 142 can inject holes into the second light-emitting unit 13.

[0122] In some embodiments, the material of the light-emitting layer 131 includes a host material and a guest material.

[0123] For example, the host material can be configured to: transport holes or electrons, and / or, recombine electrons with holes to form excitons and transfer exciton energy to the guest material.

[0124] For example, the guest material can be configured to: emit photons using exciton energy transferred from the host material, and / or, recombine electrons and holes to form excitons and emit photons.

[0125] In some examples, the guest material is a fluorescent material, which can emit light using singlet excitons; in other examples, the guest material is a phosphorescent material or a delayed fluorescence material, which can emit light using triplet excitons.

[0126] In some examples, the host material may include one material, while in other examples, the host material may include two or more materials. For example, the host material may include a first host material and a second host material, wherein the first host material is a hole-type material and the second host material is an electronic-type material.

[0127] For example, when multiple light-emitting devices 100 include a first light-emitting device 101, and the first light-emitting device 101 is used to emit blue light, the host material of the light-emitting layer 131 of the first light-emitting device 101 can be a carbazole derivative, such as 1,3-bis(N-carbazolyl)benzene (mCP), 2-amino-4-(2-amino-4-methoxyphenyl)-5-methyl-2H-carbazole (UGH2), or bis(p-tolyl)carbazole oxide (DCPPO), etc.; the guest material can be a metal complex or metal coordination compound, such as bis(4,6-difluorophenylpyridine-C 2 ,N)(pyridinecarboxylate)iridium(III)(FIrpic), etc.

[0128] For example, when multiple light-emitting devices 100 include a second light-emitting device 102, and the second light-emitting device 102 is used to emit green light, the host material of the light-emitting layer 131 of the second light-emitting device 102 can be a phosphorescent host material, and the guest material can be a green phosphorescent dopant. For example, the host material of the light-emitting layer 131 of the second light-emitting device 102 can be a coumarin dye, a quinacridone copper derivative, a polycyclic aromatic hydrocarbon, a diamine anthracene derivative, or a carbazole derivative, such as N,N'-dimethylquinacridone (DMQA), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyldiamine (BA-NPB), or tris(8-hydroxyquinoline)aluminum (Alq3). The guest material can be a metal complex, such as tris(2-phenylpyridine)iridium (Ir(ppy)3) or di(2-phenylpyridine)-acetylacetone iridium (Ir(ppy)2(acac)).

[0129] In some examples, where multiple light-emitting devices 100 include a third light-emitting device 103 for emitting red light, the host material of the light-emitting layer 131 of the third light-emitting device 103 can be a phosphorescent host material and the guest material can be a red phosphorescent dopant. The host material of the light-emitting layer 131 of the third light-emitting device 103 can be a 4-(dicyanomethyl)-2-methyl-6-(p-dimethylaminophenyl)-H-pyran (DCM) series material, such as 4-(dicyanomethyl)-2-methyl-6-(p-dimethylaminophenyl)-H-pyran (DCM), 4-(dicyanomethyl)-2-methyl-6-(p-dimethylaminophenyl)-H-pyran (DCJTB) or 4-(dicyanomethyl)-2-methyl-6-(p-dimethoxyphenyl)-H-pyran, etc., and the guest material can be a metal complex, such as di(3-phenylpyridine)di(propylene glycol)iridium (Ir(piq)2(acac)), platinum octaethylporphyrin (PtOEP) or di(8-tripropyl)di(pyridocarbazoline)iridium (Ir(btp)2(acac)), etc.

[0130] As mentioned in the background, in the field of organic semiconductors, OLED light-emitting devices have the advantages of self-illumination, wide viewing angle, high contrast, fast response speed, wide operating temperature range, and can be fabricated into flexible products.

[0131] Stacked OLED light-emitting devices can achieve superior performance compared to traditional single-layer OLED light-emitting devices, such as higher efficiency and higher brightness, giving them broad application prospects. Specifically, since OLEDs emit light through current, under the same current density, the luminous intensity of a stacked OLED light-emitting device 100 composed of n identical light-emitting units 13 is n times that of a traditional OLED light-emitting device 100 composed of a single light-emitting unit 13. Therefore, the current efficiency of the stacked OLED light-emitting device 100 is n times that of the traditional OLED light-emitting device 100. The stacked OLED light-emitting device 100 plays a crucial role in the fields of OLED displays and lighting.

[0132] In some implementations, there is a problem that the light emission efficiency and lifespan of light-emitting devices of different colors (e.g., first light-emitting device 101, second light-emitting device 102, and third light-emitting device 103) are inconsistent in the display substrate containing stacked OLED light-emitting devices.

[0133] Based on this, some embodiments of this disclosure provide a display substrate 200, as shown in Figures 7A, 7B, and 11. The display substrate 200 includes a substrate 210, an isolation structure 250, and a first light-emitting device 101, a second light-emitting device 102, and a third light-emitting device 103. The isolation structure 250 is disposed on the substrate 210. The first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 are disposed on the substrate 210. The first light-emitting device 101 emits a first color light. The second light-emitting device 102 emits a second color light, the wavelength λ2 of which is greater than the wavelength λ1 of the first color light. The third light-emitting device 103 emits a third color light, the wavelength λ3 of which is greater than the wavelength λ2 of the second color light.

[0134] Each of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 includes a first electrode 15, a second electrode 16, at least two light-emitting units 13, and at least one charge-generating unit 14. The first electrode 15 and the second electrode 16 are disposed opposite to each other along a first direction X. The at least two light-emitting units 13 are located between the first electrode 15 and the second electrode 16. The at least one charge-generating unit 14 is located between two adjacent light-emitting units 13; wherein, the isolation structure 250 is used to isolate the charge-generating unit 14; the dimension of the charge-generating unit 14 along the first direction X is a first thickness D, and the first thickness D is greater than or equal to and less than or equal to

[0135] For example, the first thickness D can be or wait.

[0136] Here, the description of the first light-emitting device 101, the second light-emitting device 102, the third light-emitting device 103, and the charge generating unit 14 can be found in the foregoing exemplary description of the first light-emitting device 101, the second light-emitting device 102, the third light-emitting device 103, and the charge generating unit 14, and will not be repeated here.

[0137] In some examples, as shown in Figure 7A, the isolation structure 250 defines a plurality of pixel openings K; the first light-emitting device 101, the second light-emitting device 102 and the third light-emitting device 103 are disposed within the plurality of pixel openings K.

[0138] As shown in FIG7A, when the display substrate 200 further includes the aforementioned pixel defining layer 221, the pixel defining layer 221 can be understood as part of the isolation structure 250, and the opening Q of the pixel defining layer 221 can be understood as part of the pixel opening K.

[0139] In some examples, in addition to the pixel defining layer 221, the isolation structure 250 also includes a portion disposed on the pixel defining layer 221, which can be used to block the charge generating unit 14.

[0140] Here, the material of the isolation structure 250 can be a conductive material, an insulating material, or a dielectric material; there are no restrictions here.

[0141] Understandably, by including the isolation structure 250 in the display substrate 200, the isolation structure 250 can isolate the charge generation units 14 in different pixel openings K, prevent the generation of transverse current between the charge generation units 14, avoid color crosstalk, and make the color purity of the display substrate 200 higher.

[0142] In some examples, the first electrode 15 is the anode and the second electrode 16 is the cathode; in other examples, the first electrode 15 is the cathode and the second electrode 16 is the anode; for a description of the anode and cathode, please refer to the foregoing exemplary description of the anode and cathode, which will not be repeated here.

[0143] In some examples, as shown in FIG7B, the second electrode 16 is further away from the substrate 210 relative to the first electrode 15; in other examples, the first electrode 15 is further away from the substrate 210 relative to the second electrode 16.

[0144] In some examples, as shown in FIG7B, the display substrate 200 is a single-sided light-emitting display panel, and its light-emitting side 200A and non-light-emitting side 200B are arranged along the first direction X; in this case, the second electrode 16 may be closer to the light-emitting side 200A of the display substrate 200 relative to the first electrode 15; or, the first electrode 15 may be closer to the light-emitting side of the display substrate 200 relative to the second electrode 16.

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

[0146] In some examples, as shown in Figure 7B, the charge generating unit 14 is a common film layer shared by the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103. In this case, the charge generating unit 14 in the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 has the same thickness.

[0147] In other examples, the charge generating unit 14 is set independently. In this case, any two of the thicknesses of the charge generating unit 14 in the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 may be the same or different.

[0148] Understandably, when the first thickness D is small, it may lead to insufficient electron or hole injection, resulting in higher driving voltages and energy consumption for the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103. When the first thickness D is large, it may reduce transmittance, affecting the luminous efficiency of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103. Furthermore, it may cause a significant difference in thickness between the portion of the charge generation unit 14 that performs electron injection and the portion that performs hole injection, leading to a deviation in the amount of electrons and holes injected. This reduces the exciton generation rate and causes the recombination region of electrons and holes to deviate from the light-emitting layer, affecting other materials in the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 and reducing device lifetime. Therefore, by adjusting the first thickness D within a certain range... The optimal setting of the first thickness D allows for a reasonable range, which serves several purposes: firstly, it avoids insufficient electron and hole injection, resulting in lower driving voltages for the first, second, and third light-emitting devices 101, 102, and 103; secondly, it prevents deviations in the amount of electron and hole injection, enabling recombination of electrons and holes within the light-emitting region of the light-emitting unit (e.g., the light-emitting layer described in detail below), thereby improving the luminous efficiency and lifetime of the first, second, and third light-emitting devices 101, 102, and 103; and thirdly, it allows for higher transmittance, further enhancing the luminous efficiency of the first, second, and third light-emitting devices 101, 102, and 103. This improves the consistency of the light extraction efficiency and lifetime of the first, second, and third light-emitting devices 101, 102, and 103.

[0149] In some embodiments, as shown in Figures 7B to 10, the light-emitting device 100 has a light-emitting side 100A and a non-light-emitting side 100B disposed opposite to each other; the second electrode 16 of the light-emitting device 100 is closer to the light-emitting side 100A of the light-emitting device 100 relative to the first electrode 15; the at least two light-emitting units 13 of the light-emitting device 100 include a first light-emitting unit 13A and a second light-emitting unit 13B. The first light-emitting unit 13A is closer to the first electrode 15 relative to the second light-emitting unit 13B.

[0150] In the first light-emitting device 101, the first light-emitting unit 13A includes a first light-emitting layer 1311A; the second light-emitting unit 13B includes a second light-emitting layer 1311B. In the second light-emitting device 102, the first light-emitting unit 13A includes a third light-emitting layer 1312A; the second light-emitting unit 13B includes a fourth light-emitting layer 1312B. In the third light-emitting device 103, the first light-emitting unit 13A includes a fifth light-emitting layer 1313A; the second light-emitting unit 13B includes a sixth light-emitting layer 1313B.

[0151] The first light-emitting unit 13A further includes a first functional unit 18 located between the first light-emitting layer 1311A and the first electrode 15, between the third light-emitting layer 1312A and the first electrode 15, or between the fifth light-emitting layer 1313A and the first electrode 15; the first functional unit 18 has a second thickness along the first direction X. The second light-emitting unit 13B further includes a second functional unit 17 located between the second light-emitting layer 1311B and the charge-generating unit 14, between the fourth light-emitting layer 1312B and the charge-generating unit 14, or between the sixth light-emitting layer 1313B and the charge-generating unit 14; the second functional unit 17 has a third thickness along the first direction X; wherein, in the same light-emitting device, the second thickness is greater than or equal to the third thickness.

[0152] Specifically, as shown in Figure 8, the second thickness A1 corresponding to the first light-emitting device 101 and the third thickness A2 corresponding to the first light-emitting device 101 satisfy the following condition: A1≥A2.

[0153] As shown in Figure 9, the second thickness B1 corresponding to the second light-emitting device 102 and the third thickness B2 corresponding to the second light-emitting device 102 satisfy the following condition: B1≥B2.

[0154] As shown in Figure 10, the following condition is satisfied between the second thickness F1 corresponding to the third light-emitting device 103 and the third thickness F2 corresponding to the third light-emitting device 103: F1≥F2.

[0155] For example, the second thickness A1 corresponding to the first light-emitting device 101 can be or The third thickness A2 corresponding to the first light-emitting device 101 can be... or wait.

[0156] For example, the second thickness B1 corresponding to the second light-emitting device 102 can be... or The third thickness B2 corresponding to the second light-emitting device 102 can be... or wait.

[0157] For example, the second thickness F1 corresponding to the third light-emitting device 103 can be... or The third thickness F2 corresponding to the third light-emitting device 103 can be... or wait.

[0158] Here, the description of the first light-emitting layer 1311A, the second light-emitting layer 1311B, the third light-emitting layer 1312A, the fourth light-emitting layer 1312B, the fifth light-emitting layer 1313A and the sixth light-emitting layer 1313B can be referred to the exemplary description of the light-emitting layer 131 (see Figure 4) above, and will not be repeated here.

[0159] It should be explained that Figures 7B and 10 show blank areas on the side away from the first electrode 15 of the first light-emitting layer 1311A, the third light-emitting layer 1312A, the second light-emitting layer 1311B, and the fourth light-emitting layer 1312B. This is to illustrate the possible thickness differences between the first light-emitting layer 1311A, the third light-emitting layer 1312A, and the fifth light-emitting layer 1313A, as well as the possible thickness differences between the second light-emitting layer 1311B, the fourth light-emitting layer 1312B, and the sixth light-emitting layer 1313B. In actual applications, no gaps are left in the various light-emitting devices 100 of the display substrate 200, or no material is filled in these blank areas. In other words, the first light-emitting layer 1311A can be in direct contact with the film layer located on the side away from the first electrode 15; the third light-emitting layer 1312A can be in direct contact with the film layer located on the side away from the first electrode 15; the second light-emitting layer 1311B can be in direct contact with the film layer located on the side away from the first electrode 15; and the fourth light-emitting layer 1312B can be in direct contact with the film layer located on the side away from the first electrode 15.

[0160] In some examples, the first functional unit 18 can be a hole transport unit of the first light-emitting unit 13A, and the second functional unit 17 can be a hole transport unit of the second light-emitting unit 13B; in other examples, the first functional unit 18 can be an electron transport unit of the first light-emitting unit 13A, and the second functional unit 17 can be an electron transport unit of the second light-emitting unit 13B. Here, the description of the hole transport unit and the electron transport unit can be referred to the exemplary description of the hole transport unit and the electron transport unit described above, and will not be repeated here.

[0161] It should be understood that when the first functional unit 18 is the hole transport unit of the first light-emitting unit 13A and the second functional unit 17 is the hole transport unit of the second light-emitting unit 13B, the second thickness A1 corresponding to the first light-emitting device 101, the second thickness B1 corresponding to the second light-emitting device 102, and the second thickness F1 corresponding to the third light-emitting device 103 can be the sum of the thicknesses of the hole injection layer HTL, the hole transport layer HTL, and the electron blocking layer EBL (as shown in Figures 8 to 10), or the sum of the thicknesses of any two of the hole injection layer HTL, the hole transport layer HTL, and the electron blocking layer EBL, or the thickness of any one of the hole injection layer HTL, the hole transport layer HTL, and the electron blocking layer EBL.

[0162] When the first functional unit 18 is the electron transport unit of the first light-emitting unit 13A and the second functional unit 17 is the electron transport unit of the second light-emitting unit 13B, the second thickness A1 corresponding to the first light-emitting device 101, the second thickness B1 corresponding to the second light-emitting device 102, and the second thickness F1 corresponding to the third light-emitting device 103 can be the sum of the thicknesses of the electron injection layer ETL, the electron transport layer ETL, and the hole blocking layer HBL (as shown in Figures 8 to 10), or the sum of the thicknesses of any two of the electron injection layer ETL, the electron transport layer ETL, and the hole blocking layer HBL, or the thickness of any one of the electron injection layer ETL, the electron transport layer ETL, and the hole blocking layer HBL.

[0163] Understandably, compared to the charge carriers (holes or electrons) generated and injected into the second light-emitting unit 13B by the charge generation unit 14, the first electrode 15 generates and injects a relatively large number of charge carriers into the first light-emitting unit 13A. This results in the first functional unit 18 needing to transport a relatively large number of charge carriers, while the second functional unit 17 needs to transport a relatively small number of charge carriers. Therefore, by setting the second thickness to be greater than or equal to the third thickness, the interaction between the first electrode 15 and the first light-emitting layer 1311A, the third light-emitting layer 1312A, or the fifth light-emitting layer 1313 can be mitigated. The carrier transport rate between A and B allows the carriers in the first light-emitting unit 13A and the second light-emitting unit 13B to be smoothly transported to their corresponding light-emitting layers, enabling electrons and holes to recombine within the light-emitting layers and matching the amount of holes and electrons within the light-emitting layers. This can improve the exciton generation rate and prevent excitons from accumulating in areas other than the light-emitting layers, thereby improving the efficiency and lifetime of the light-emitting device 100. It can also improve the consistency of the light extraction efficiency and lifetime of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103.

[0164] In some embodiments, as shown in Figures 7B to 11, at least two of the first light-emitting layer 1311A, the third light-emitting layer 1312A, and the fifth light-emitting layer 1313A have the same size along the first direction X.

[0165] For example, the dimension E1 of the first light-emitting layer 1311A along the first direction X can be the same as the dimension E3 of the third light-emitting layer 1312A along the first direction X; for another example, the dimension E1 of the first light-emitting layer 1311A along the first direction X can be the same as the dimension E5 of the fifth light-emitting layer 1313A along the first direction X; and for yet another example, as shown in Figure 11, the dimension E3 of the third light-emitting layer 1312A along the first direction X can be the same as the dimension E5 of the fifth light-emitting layer 1313A along the first direction X.

[0166] In some embodiments, as shown in Figures 7A, 7B to 11, at least two of the second light-emitting layer 1311B, the fourth light-emitting layer 1312B, and the sixth light-emitting layer 1313B have the same size along the first direction X.

[0167] For example, the dimension E2 of the second light-emitting layer 1311B along the first direction X can be the same as the dimension E4 of the fourth light-emitting layer 1312B along the first direction X. For another example, the dimension E2 of the second light-emitting layer 1311B along the first direction X can be the same as the dimension E6 of the sixth light-emitting layer 1313B along the first direction X. For yet another example, as shown in Figure 11, the dimension E4 of the fourth light-emitting layer 1312B along the first direction X can be the same as the dimension E6 of the sixth light-emitting layer 1313B along the first direction X.

[0168] Understandably, at least one of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 (e.g., the second light-emitting device 102 and / or the third light-emitting device 103) has a thicker light-emitting layer to form a certain light-emitting buffer. Therefore, through the above arrangement, the thicknesses of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 can be relatively consistent. In this way, the thickness of at least one of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 can be more consistent with the thickness of the light-emitting layer of the light-emitting device 100 with the light-emitting buffer. Thus, the thickness of the light-emitting layer of the light-emitting device 100 in the display substrate 200 can be larger, and the exciton recombination region in the light-emitting device 100 can be wider, which can increase the exciton utilization rate and improve the luminous efficiency of the light-emitting device 100. Moreover, through the above settings, the thickness of the light-emitting layer of the light-emitting device 100 can be made more uniform, or the thickness difference between the light-emitting layers can be made smaller. In this way, the control effect of the isolation structure 250 on the emitted light can be improved, and the process yield of the display substrate 200 can be improved.

[0169] In some examples, the wavelength of the third color light (e.g., red light) is relatively large. In this case, the exciton recombination region of the third light-emitting device 103 (e.g., red light-emitting device) is more likely to deflect from the light-emitting layer compared to the first light-emitting device 101 (e.g., blue light-emitting device) and the second light-emitting device 102 (e.g., green light-emitting device).

[0170] In some examples, the material type of the light-emitting layer of the first light-emitting device 101 (e.g., a blue light-emitting device) is different from the material type of the light-emitting layers of the second light-emitting device 102 (e.g., a green light-emitting device) and the third light-emitting device 103 (e.g., a red light-emitting device). The material types of the light-emitting layers of the second light-emitting device 102 (e.g., a green light-emitting device) and the third light-emitting device 103 (e.g., a red light-emitting device) are more consistent.

[0171] In some embodiments, as shown in Figures 7B to 11, the dimension E1 of the first light-emitting layer 1311A along the first direction X is smaller than the dimension E3 of the third light-emitting layer 1312A along the first direction X; the dimension E1 of the first light-emitting layer 1311A along the first direction X is smaller than the dimension E5 of the fifth light-emitting layer 1313A along the first direction X; the dimension E3 of the third light-emitting layer 1312A along the first direction X is smaller than or equal to the dimension E5 of the fifth light-emitting layer 1313A along the first direction X. The dimension E2 of the second light-emitting layer 1311B along the first direction X is smaller than the dimension E4 of the fourth light-emitting layer 1312B along the first direction X; the dimension E2 of the second light-emitting layer 1311B along the first direction X is smaller than the dimension E6 of the sixth light-emitting layer 1313B along the first direction X; the dimension E4 of the fourth light-emitting layer 1312B along the first direction X is smaller than or equal to the dimension E6 of the sixth light-emitting layer 1313B along the first direction X. Here, the dimension of the light-emitting layer along the first direction X is simply referred to as the thickness of the light-emitting layer, and the same applies below.

[0172] Understandably, firstly, through the above-mentioned configuration, the thickness of the fifth light-emitting layer 1313A and the sixth light-emitting layer 1313B can be relatively large, forming a thicker light-emitting buffer zone. This prevents the recombination region of holes and electrons in the third light-emitting device 103 from shifting away from the light-emitting layer, thus preventing excitons from accumulating in areas other than the light-emitting layer and improving the lifetime of the third light-emitting device 103. Secondly, through the above-mentioned configuration, the thickness of the first light-emitting layer 1311A and the second light-emitting layer 1311B can be relatively small. This allows the thickness of the first light-emitting layer 1311A and the second light-emitting layer 1311B to match the material properties of the light-emitting layer of the first light-emitting device 101, improving the consistency of the light extraction efficiency and lifetime of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103. Thirdly, the microcavity length of the first light-emitting device 101 can be better matched with the wavelength λ1 of the first color light, the microcavity length of the second light-emitting device 102 can be better matched with the wavelength λ2 of the second color light, and the microcavity length of the third light-emitting device 103 can be better matched with the wavelength λ3 of the third color light. This can create a microcavity effect in the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103, thereby improving the luminous efficiency of the display substrate 200.

[0173] In some embodiments, as shown in FIG7B, FIG8 and FIG11, the dimension E1 of the first light-emitting layer 1311A along the first direction X is equal to the dimension E2 of the second light-emitting layer 1311B along the first direction X.

[0174] In some embodiments, as shown in FIG7B, FIG9 and FIG11, the dimension E3 of the third light-emitting layer 1312A along the first direction X is equal to the dimension E4 of the fourth light-emitting layer 1312B along the first direction X.

[0175] In some embodiments, as shown in FIG7B, FIG10 and FIG11, the dimension E5 of the fifth light-emitting layer 1313A along the first direction X is equal to the dimension E6 of the sixth light-emitting layer 1313B along the first direction X.

[0176] In other words, in the same light-emitting device 100, the size of the light-emitting layer contained in the first light-emitting unit 13A along the first direction X is equal to the size of the light-emitting layer contained in the second light-emitting unit 13B along the first direction X.

[0177] Understandably, through the above settings, the dimensions of the two light-emitting layers in the same light-emitting device 100 along the first direction X can be made consistent, the exciton quantity in the two light-emitting layers can be made relatively consistent, and the luminous efficiency of the two light-emitting units can be made relatively consistent. In this way, the overall luminous efficiency of the light-emitting device 100 can be improved.

[0178] In some embodiments, as shown in Figures 7B, 8, and 11, the dimension E1 of the first light-emitting layer 1311A along the first direction X ranges from 18 nm to 22 nm. The dimension E2 of the second light-emitting layer 1311B along the first direction X ranges from 18 nm to 22 nm.

[0179] For example, the size E1 of the first light-emitting layer 1311A along the first direction X can be 18nm, 19nm, 20nm, 21.5nm or 22nm, etc.

[0180] For example, the size E2 of the second light-emitting layer 1311B along the first direction X can be 18nm, 19.5nm, 20nm, 21.5nm and 22nm, etc.

[0181] It should be understood that when the thickness of the first light-emitting layer 1311A and the second light-emitting layer 1311B is large, it may lead to an increase in the turn-on voltage of the first light-emitting device 101, resulting in higher energy consumption. Moreover, when the thickness of the first light-emitting layer 1311A and the second light-emitting layer 1311B increases within a certain range, it can increase the exciton recombination region and improve the luminous efficiency of the first light-emitting device 101. However, since the position of the exciton recombination region is relatively fixed, when the efficiency of the first light-emitting device 101 reaches a high value, that is, when the thickness of the first light-emitting layer 1311A and the second light-emitting layer 1311B exceeds a certain thickness value, the change in the relative position of the first light-emitting layer 1311A and the second light-emitting layer 1311B may cause the exciton recombination region to shift, resulting in a downward trend in the luminous efficiency of the first light-emitting device 101.

[0182] Understandably, through the above settings, the thickness of the first light-emitting layer 1311A and the second light-emitting layer 1311B can be within a suitable range. While ensuring a low start-up voltage and high luminous efficiency, the thickness of the first light-emitting layer 1311A and the second light-emitting layer 1311B can be relatively small, so that the thickness of the first light-emitting layer 1311A and the second light-emitting layer 1311B can match the material properties of the light-emitting layer of the first light-emitting device 101.

[0183] In some embodiments, as shown in Figures 7B, 9, and 11, the dimension E3 of the third light-emitting layer 1312A along the first direction X ranges from 30 nm to 50 nm. The dimension E4 of the fourth light-emitting layer 1312B along the first direction X ranges from 30 nm to 50 nm.

[0184] For example, the dimension E3 of the third light-emitting layer 1312A along the first direction X can be 30nm, 37nm, 40nm, 45nm or 50nm, etc.

[0185] For example, the dimension E4 of the fourth light-emitting layer 1312B along the first direction X can be 30nm, 34nm, 40nm, 46nm, and 50nm, etc.

[0186] Similarly, through the above settings, the thicknesses of the third light-emitting layer 1312A and the fourth light-emitting layer 1312B can be within a suitable range. While ensuring a low start-up voltage and high luminous efficiency, firstly, the thicknesses of the third light-emitting layer 1312A and the fourth light-emitting layer 1312B can be better matched with the material properties of the light-emitting layer of the second light-emitting device 100; secondly, the thicknesses of the third light-emitting layer 1312A and the fourth light-emitting layer 1312B can be larger, forming a light-emitting buffer of a certain thickness, which can prevent the recombination region of holes and electrons in the second light-emitting device 102 from shifting away from the light-emitting layer.

[0187] In some embodiments, as shown in Figures 7B, 10, and 11, the fifth light-emitting layer 1313A has a dimension E5 ranging from 30 nm to 50 nm along the first direction X. The sixth light-emitting layer 1313B has a dimension E6 ranging from 30 nm to 50 nm along the first direction X.

[0188] For example, the dimension E5 of the fifth light-emitting layer 1313A along the first direction X can be 30nm, 35nm, 41nm, 45nm or 50nm, etc.

[0189] For example, the size E6 of the sixth light-emitting layer 1313B along the first direction X can be 30nm, 38nm, 40nm, 45nm or 50nm, etc.

[0190] Similarly, through the above settings, the thicknesses of the fifth light-emitting layer 1313A and the sixth light-emitting layer 1313B can be within a suitable range. While ensuring a low start-up voltage and high luminous efficiency, firstly, the thicknesses of the fifth light-emitting layer 1313A and the sixth light-emitting layer 1313B can be better matched with the material properties of the light-emitting layer of the third light-emitting device 103; secondly, the thicknesses of the fifth light-emitting layer 1313A and the sixth light-emitting layer 1313B can be larger, forming a thicker light-emitting buffer zone, which can prevent the recombination region of holes and electrons in the third light-emitting device 103 from shifting away from the light-emitting layer.

[0191] The above is an exemplary description of the dimensions of the light-emitting layers in the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103. The relationship between the second thickness, the third thickness, and the first thickness D in the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 will be described exemplary below. In the following embodiments, the dimension of the structure or layer along the first direction X is simply referred to as the thickness of the structure or layer.

[0192] It should be understood that when the first functional unit 18 is located between the first light-emitting layer 1311A, the third light-emitting layer 1312A or the fifth light-emitting layer 1313A and the first electrode 15, the relative positional relationship between the first light-emitting layer 1311A, the third light-emitting layer 1312A or the fifth light-emitting layer 1313A and the first electrode 15, and between the first light-emitting layer 1311A, the third light-emitting layer 1312A or the fifth light-emitting layer 1313A and the second electrode 16 can be adjusted by adjusting the second thickness (the dimension of the first functional unit 18 along the first direction X), for example by adjusting the relative relationship between the second thickness and the first thickness, thereby adjusting the optical distance of the light-emitting device 100. Similarly, by adjusting the third thickness (the dimension of the second functional unit 17 along the first direction X), for example by adjusting the relative relationship between the third thickness and the first thickness, the relative positional relationship between the second light-emitting layer 1311B, the fourth light-emitting layer 1312B or the sixth light-emitting layer 1313B and the first electrode 15, and between the second light-emitting layer 1311B, the fourth light-emitting layer 1312B or the sixth light-emitting layer 1313B and the second electrode 16 can be adjusted, thereby adjusting the optical distance of the light-emitting device 100.

[0193] In some embodiments, as shown in FIG8, in the first light-emitting device 101, the ratio between the second thickness A1 and the first thickness D (hereinafter referred to as the first ratio) ranges from 4.0 to 5.0; the ratio between the third thickness A2 and the first thickness D (hereinafter referred to as the second ratio) ranges from 2.0 to 3.0.

[0194] That is, in the first light-emitting device 101, the following conditions are satisfied between the second thickness A1 and the first thickness D, and between the third thickness A2 and the first thickness D:

[0195] For example, the first ratio can be 4.0, 4.2, 4.5, 4.6, 4.8 or 5.0, etc.

[0196] For example, the second ratio can be 2.0, 2.2, 2.4, 2.5, 2.8 or 3.0, etc.

[0197] In some examples, the first functional unit 18 is the hole transport unit of the first light-emitting unit 13A, and the second functional unit 17 is the hole transport unit of the second light-emitting unit 13B. In this case, in the first light-emitting device 101, the ratio between the thickness of the hole transport unit of the first light-emitting unit 13A and the thickness of the charge generating unit 14 is in the range of 4.0 to 5.0; the ratio between the thickness of the hole transport unit of the second light-emitting unit 13B and the thickness of the charge generating unit 14 is in the range of 2.0 to 3.0.

[0198] In some examples, the first functional unit 18 is the electron transport unit of the first light-emitting unit 13A, and the second functional unit 17 is the electron transport unit of the second light-emitting unit 13B. In this case, in the first light-emitting device 101, the ratio between the thickness of the electron transport unit of the first light-emitting unit 13A and the thickness of the charge generating unit 14 is in the range of 4.0 to 5.0; the ratio between the thickness of the electron transport unit of the second light-emitting unit 13B and the thickness of the charge generating unit 14 is in the range of 2.0 to 3.0.

[0199] Understandably, by setting the first ratio range to 4.0–5.0 and the second ratio range to 2.0–3.0, firstly, the microcavity distance of the first light-emitting device 101 can be kept within a suitable range, which can improve the matching between the microcavity distance and the wavelength of the first color light, thereby achieving a stronger microcavity effect and thus improving the light extraction efficiency of the first light-emitting device 101; secondly, the recombination region of holes and electrons can be located in the first light-emitting layer 1311A and / or the second light-emitting layer 1311B, so as to avoid the impact on the device lifetime when charge carriers recombine in other regions other than the first light-emitting layer 1311A and the second light-emitting layer 1311B, thereby improving the device lifetime of the first light-emitting device 101.

[0200] In some embodiments, as shown in Figures 7B and 9, in the second light-emitting device 102, the ratio between the second thickness B1 and the first thickness D (hereinafter referred to as the third ratio) ranges from 5.0 to 6.0; the ratio between the third thickness B2 and the first thickness D (hereinafter referred to as the fourth ratio) ranges from 2.0 to 3.0.

[0201] That is, in the second light-emitting device 102, the second thickness B1 and the first thickness D, and the third thickness B2 and the first thickness D, satisfy the following:

[0202] For example, the third ratio can be 5.0, 5.2, 5.5, 5.6, 5.8 or 6.0, etc.

[0203] For example, the fourth ratio can be 2.0, 2.2, 2.4, 2.6, 2.9 or 3.0, etc.

[0204] In some examples, the first functional unit 18 is the hole transport unit of the first light-emitting unit 13A, and the second functional unit 17 is the hole transport unit of the second light-emitting unit 13B. In this case, in the second light-emitting device 102, the ratio between the thickness of the hole transport unit of the first light-emitting unit 13A and the thickness of the charge generating unit 14 is in the range of 5.0 to 6.0; the ratio between the thickness of the hole transport unit of the second light-emitting unit 13B and the thickness of the charge generating unit 14 is in the range of 2.0 to 3.0.

[0205] In some examples, the first functional unit 18 is the electron transport unit of the first light-emitting unit 13A, and the second functional unit 17 is the electron transport unit of the second light-emitting unit 13B. In this case, in the second light-emitting device 102, the ratio of the thickness of the electron transport unit of the first light-emitting unit 13A to the thickness of the charge generating unit 14 is in the range of 5.0 to 6.0; the ratio of the thickness of the electron transport unit of the second light-emitting unit 13B to the thickness of the charge generating unit 14 is in the range of 2.0 to 3.0.

[0206] Understandably, by setting the third ratio range to 5.0–6.0 and the fourth ratio range to 2.0–3.0, firstly, the microcavity distance of the second light-emitting device 102 can be kept within a suitable range, which can improve the matching between the microcavity distance and the wavelength of the second color light to achieve a stronger microcavity effect, thereby improving the light extraction efficiency of the second light-emitting device 102; secondly, the recombination region of holes and electrons can be located in the third light-emitting layer 1312A and / or the fourth light-emitting layer 1312B, so as to avoid the impact on the device lifetime when charge carriers recombine in other regions other than the third light-emitting layer 1312A and the fourth light-emitting layer 1312B, thereby improving the device lifetime of the second light-emitting device 102.

[0207] In some embodiments, as shown in FIG7B and FIG10, in the third light-emitting device 103, the ratio between the second thickness F1 and the first thickness D (hereinafter referred to as the fifth ratio) ranges from 7.0 to 8.0; the ratio between the third thickness F2 and the first thickness D (hereinafter referred to as the sixth ratio) ranges from 3.0 to 4.0.

[0208] That is, in the third light-emitting device 103, the following conditions are satisfied between the second thickness F1 and the first thickness D, and between the third thickness F2 and the first thickness D:

[0209] For example, the fifth ratio can be 7.0, 7.2, 7.5, 7.6, 7.8 or 8.0, etc.

[0210] For example, the sixth ratio can be 3.0, 3.1, 3.4, 3.6, 3.8 or 4.0, etc.

[0211] In some examples, the first functional unit 18 is the hole transport unit of the first light-emitting unit 13A, and the second functional unit 17 is the hole transport unit of the second light-emitting unit 13B; in this case, the ratio between the thickness of the hole transport unit of the first light-emitting unit 13A and the thickness of the charge generating unit 14 is in the range of 7.0 to 8.0; the ratio between the thickness of the hole transport unit of the second light-emitting unit 13B and the thickness of the charge generating unit 14 is in the range of 3.0 to 4.0.

[0212] In some examples, the first functional unit 18 is the electron transport unit of the first light-emitting unit 13A, and the second functional unit 17 is the electron transport unit of the second light-emitting unit 13B; in this case, the ratio between the thickness of the electron transport unit of the first light-emitting unit 13A and the thickness of the charge generating unit 14 is in the range of 7.0 to 8.0; the ratio between the thickness of the electron transport unit of the second light-emitting unit 13B and the thickness of the charge generating unit 14 is in the range of 3.0 to 4.0.

[0213] Understandably, by setting the fifth ratio range to 7.0–8.0 and the sixth ratio range to 3.0–4.0, firstly, the microcavity distance of the third light-emitting device 103 can be kept within a suitable range, which can improve the matching between the microcavity distance and the wavelength of the third color light, thereby achieving a stronger microcavity effect and improving the light extraction efficiency of the third light-emitting device 103; secondly, the recombination region of holes and electrons can be located in the fifth light-emitting layer 1313A and / or the sixth light-emitting layer 1313B, so as to avoid the impact on the device lifetime when charge carriers recombine in other regions other than the fifth light-emitting layer 1313A and the sixth light-emitting layer 1313B, thereby improving the device lifetime of the third light-emitting device 103.

[0214] In some embodiments, as shown in Figures 7B and 11, the first electrode 15 is the anode, and the first functional unit 18 includes multiple hole transport functional layers. The second functional unit 17 includes multiple hole transport functional layers. The first light-emitting unit 13A further includes a fourth functional unit 19B located between the first light-emitting layer 1311A and the charge-generating unit 14, between the third light-emitting layer 1312A and the charge-generating unit 14, or between the fifth light-emitting layer 1313A and the charge-generating unit 14; the fourth functional unit 19B includes at least one electron transport functional layer. The second light-emitting unit 13B further includes a third functional unit 19A located between the second light-emitting layer 1311B and the second electrode 16, between the fourth light-emitting layer 1312B and the second electrode 16, or between the sixth light-emitting layer 1313B and the second electrode 16; the third functional unit 19A includes multiple electron transport functional layers (e.g., including electron transport functional layers represented by reference numerals 191, 192, and 193 in Figures 7B to 11).

[0215] In some examples, as shown in Figures 7B and 11, a multilayer hole transport functional layer may include any number of hole injection layers (HIL), hole transport layers (HTL), and electron blocking layers (EBL). A multilayer electron transport functional layer may include any number of electron injection layers (EIL), electron transport layers (ETL), and hole blocking layers (HBL).

[0216] In some embodiments, as shown in FIG7B and FIG11, at least one of the dimensions of the first light-emitting layer 1311A, the second light-emitting layer 1311B, the third light-emitting layer 1312A, the fourth light-emitting layer 1312B, the fifth light-emitting layer 1313A, and the sixth light-emitting layer 1313B along the first direction X is smaller than the dimension of one of the multiple hole transport functional layers included in the first functional unit 18 and the second functional unit 17 along the first direction X.

[0217] In other words, a reference hole transport functional layer exists within the multilayer hole transport functional layers. Among the first light-emitting layer 1311A, the second light-emitting layer 1311B, the third light-emitting layer 1312A, the fourth light-emitting layer 1312B, the fifth light-emitting layer 1313A, and the sixth light-emitting layer 1313B, there is a comparison light-emitting layer. The dimension of the comparison light-emitting layer along the first direction X is smaller than the dimension of the reference hole transport functional layer along the first direction X. Here, there are no limitations on the number of reference hole transport functional layers or the number of comparison light-emitting layers. In other words, there can be multiple reference hole transport functional layers and multiple comparison light-emitting layers. In this case, the reference hole transport functional layers corresponding to different comparison light-emitting layers can be the same reference hole transport functional layer or different reference hole transport functional layers.

[0218] For example, a multilayer hole transport functional layer may contain a first reference hole transport functional layer, a second reference hole transport functional layer, and a third reference hole transport functional layer. The dimension E1 of the first light-emitting layer 1311A along the first direction X and / or the dimension E2 of the second light-emitting layer 1311B along the first direction X may be smaller than one of the dimensions of the first, second, or third reference hole transport functional layers along the first direction X; the dimension E3 of the third light-emitting layer 1312A along the first direction X and / or the dimension E4 of the fourth light-emitting layer 1312B along the first direction X may be smaller than another dimension of the first, second, or third reference hole transport functional layers along the first direction X; the dimension E5 of the fifth light-emitting layer 1313A along the first direction X and / or the dimension E6 of the sixth light-emitting layer 1313B along the first direction X may be smaller than yet another dimension of the first, second, or third reference hole transport functional layers along the first direction X.

[0219] In some examples, the first functional unit 18 is a shared functional unit of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103. In this case, the aforementioned multi-layer hole transport functional layer includes the hole transport functional layer shared by the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103. In other examples, some or all of the multi-layer hole transport functional layers of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 are independently configured. In this case, the aforementioned multi-layer hole transport functional layer includes the multi-layer hole transport functional layer of the first light-emitting device 101, the multi-layer hole transport functional layer of the second light-emitting device 102, and the multi-layer hole transport functional layer of the third light-emitting device 103.

[0220] Understandably, through the above configuration, the dimension of the reference hole transport functional layer along the first direction X can be larger than at least one of the dimensions of the first light-emitting layer 1311A, the second light-emitting layer 1311B, the third light-emitting layer 1312A, the fourth light-emitting layer 1312B, the fifth light-emitting layer 1313A, and the sixth light-emitting layer 1313B along the first direction X. In this way, the dimensions of the first functional unit 18 and / or the second functional unit 17 along the first direction X can be larger, the hole transport rate of the first light-emitting unit 13A and / or the second light-emitting unit 13B can be within a suitable range, and the holes in the first light-emitting unit 13A and / or the second light-emitting unit 13B can be smoothly transported to the corresponding light-emitting layer, so that electrons and holes can recombine in the light-emitting layer and the amount of holes and electrons in the light-emitting layer can be matched, which can improve the exciton generation rate and avoid the accumulation of excitons in other areas besides the light-emitting layer, thereby improving the efficiency and lifespan of the light-emitting device 100.

[0221] In some embodiments, as shown in FIG7B and FIG11, at least one of the dimensions of the first light-emitting layer 1311A, the second light-emitting layer 1311B, the third light-emitting layer 1312A, the fourth light-emitting layer 1312B, the fifth light-emitting layer 1313A, and the sixth light-emitting layer 1313B along the first direction X is smaller than the dimension of one of the multilayer electron transport functional layers included in the third functional unit 19A and the fourth functional unit 19B along the first direction X.

[0222] In other words, a reference electron transport functional layer exists within the multilayer electron transport functional layers. A comparison light-emitting layer exists within the first light-emitting layer 1311A, the second light-emitting layer 1311B, the third light-emitting layer 1312A, the fourth light-emitting layer 1312B, the fifth light-emitting layer 1313A, and the sixth light-emitting layer 1313B. The dimension of the comparison light-emitting layer along the first direction X is smaller than the dimension of the reference electron transport functional layer along the first direction X. Here, the description of the reference electron transport functional layer and the comparison light-emitting layer can be referred to the exemplary description of the reference hole transport functional layer and the comparison light-emitting layer described above, and will not be repeated here.

[0223] In some examples, the third functional unit 19A is a shared functional unit of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103. In this case, the aforementioned multi-layer electron transport functional layer includes the electron transport functional layer shared by the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103. In other examples, some or all of the multi-layer electron transport functional layers of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 are independently configured. In this case, the aforementioned multi-layer electron transport functional layer includes the multi-layer electron transport functional layer of the first light-emitting device 101, the multi-layer electron transport functional layer of the second light-emitting device 102, and the multi-layer electron transport functional layer of the third light-emitting device 103.

[0224] Understandably, through the above configuration, the dimension of the reference electron transport functional layer along the first direction X can be made larger than at least one of the dimensions E6 of the first light-emitting layer 1311A, the second light-emitting layer 1311B, the third light-emitting layer 1312A, the fourth light-emitting layer 1312B, the fifth light-emitting layer 1313A, and the sixth light-emitting layer 1313B along the first direction X. In this way, the dimensions of the third functional unit 19A and / or the fourth functional unit 19B along the first direction X can be increased, and the electron transport rate of the first light-emitting unit 13A and / or the second light-emitting unit 13B can be kept within a suitable range. This allows electrons in the first light-emitting unit 13A and / or the second light-emitting unit 13B to be smoothly transported to the corresponding light-emitting layer, enabling electrons to recombine within the light-emitting layer and matching the amount of electrons within the light-emitting layer. This can improve the exciton generation rate and prevent excitons from accumulating in areas other than the light-emitting layer, thereby improving the efficiency and lifespan of the light-emitting device 100.

[0225] In some embodiments, as shown in Figures 7B to 11, the first functional unit 18 includes a first hole transport functional layer 183, a second hole transport functional layer 182, and a third hole transport functional layer 181 arranged in a direction away from the first electrode 15. The second functional unit 17 includes a fourth hole transport functional layer 172 and a fifth hole transport functional layer 171 arranged in a direction away from the charge generation unit 14. The third functional unit 19A includes a first electron transport functional layer 193, a second electron transport functional layer 192, and a third electron transport functional layer 191 arranged in a direction away from the second electrode 16. The fourth functional unit 19B includes a fourth electron transport functional layer 194 and a fifth electron transport functional layer 195 arranged in a direction close to the charge generation unit.

[0226] In some examples, the first hole transport functional layer 183 can be a hole injection layer HIL; the second hole transport functional layer 182 and the fourth hole transport functional layer 172 can be hole transport layers HTL; and the third hole transport functional layer 181 and the fifth hole transport functional layer 171 can be electron blocking layers EBL. For a description of the hole injection layer HIL, the hole transport layer HTL, and the electron blocking layer EBL, please refer to the foregoing exemplary descriptions of the hole injection layer HIL, the hole transport layer HTL, and the electron blocking layer EBL, which will not be repeated here.

[0227] In some examples, in the first light-emitting device 101, the size of the first hole transport functional layer 183 along the first direction X ranges from 5 nm to 15 nm, the size of the second hole transport functional layer 182 along the first direction X ranges from 95 nm to 105 nm, and the size of the third hole transport functional layer 181 along the first direction X ranges from 5 nm to 10 nm. In this case, the size of the third hole transport functional layer 181 along the first direction X is less than or equal to the size of the first hole transport functional layer 183 along the first direction X, the size of the first hole transport functional layer 183 along the first direction X is less than the size of the second hole transport functional layer 182 along the first direction X, and the size of the second hole transport functional layer 182 along the first direction X is less than the size of the second hole transport functional layer 182 along the first direction X.

[0228] In some examples, in the second light-emitting device 102, the size of the first hole transport functional layer 183 along the first direction X ranges from 5nm to 15nm, the size of the second hole transport functional layer 182 along the first direction X ranges from 95nm to 105nm, and the size of the third hole transport functional layer 181 along the first direction X ranges from 40nm to 45nm. In this case, the size of the first hole transport functional layer 183 along the first direction X is smaller than the size of the third hole transport functional layer 181 along the first direction X; and the size of the third hole transport functional layer 181 along the first direction X is smaller than the size of the second hole transport functional layer 182 along the first direction X.

[0229] In some examples, in the third light-emitting device 103, the size of the first hole transport functional layer 183 along the first direction X ranges from 5 nm to 15 nm, the size of the second hole transport functional layer 182 along the first direction X ranges from 95 nm to 105 nm, and the size of the third hole transport functional layer 181 along the first direction X ranges from 80 nm to 95 nm. In this case, the size of the first hole transport functional layer 183 along the first direction X is smaller than the size of the third hole transport functional layer 181 along the first direction X; the size of the third hole transport functional layer 181 along the first direction X is smaller than or equal to the size of the second hole transport functional layer 182 along the first direction X.

[0230] In some examples, the first electron transport functional layer 193, the second electron transport functional layer 192, and the third electron transport functional layer 191 in the multilayer electron transport functional layer can be the electron injection layer EIL, the electron transport layer ETL, and the hole blocking layer HBL, respectively. The fourth electron transport functional layer 194 can be the hole blocking layer HBL, and the fifth electron transport functional layer 195 can be the electron transport layer ETL. For a description of the electron injection layer EIL, the electron transport layer ETL, and the hole blocking layer HBL, please refer to the foregoing exemplary descriptions of the electron injection layer EIL, the electron transport layer ETL, and the hole blocking layer HBL; these will not be repeated here.

[0231] In some examples, the size of the second electron transport functional layer 192 along the first direction X ranges from 30 nm to 40 nm, for example, 30 nm, 32 nm, 34 nm, 35 nm, 37 nm, or 40 nm. The size of the third electron transport functional layer 191 along the first direction X ranges from 5 nm to 10 nm; in this case, the size of the third electron transport functional layer 191 along the first direction X is smaller than the size of the second electron transport functional layer 192 along the first direction X.

[0232] Understandably, the above settings can reduce the potential barrier height that carrier transitions need to overcome, enabling efficient charge generation, effective charge injection, and rapid charge transport during the light emission process of the light-emitting device 100, thus resulting in higher luminous efficiency of the light-emitting device 100. The aforementioned charge can be either a hole or an electron.

[0233] In some embodiments, as shown in FIG8, in the first light-emitting device 101, the dimension E1 of the first light-emitting layer 1311A along the first direction X is smaller than the dimension a1 of the third hole transport functional layer 1811 along the first direction; the dimension E2 of the second light-emitting layer 1522 along the first direction X is smaller than the dimension a4 of the fifth hole transport functional layer 1711 along the first direction X.

[0234] In some examples, the dimension E1 of the first light-emitting layer 1311A along the first direction X is smaller than any of the dimensions of the multilayer hole transport functional layers in the corresponding first light-emitting unit 13A along the first direction X, and smaller than any of the dimensions of the multilayer electron transport functional layers in the corresponding first light-emitting unit 13A along the first direction X.

[0235] Understandably, through the above settings, the thicknesses of the first light-emitting layer 1311A and the second light-emitting layer 1311B can be within a suitable range. While ensuring luminous efficiency, the thicknesses of the first light-emitting layer 1311A and the second light-emitting layer 1311B can be relatively small. This allows the thicknesses of the first light-emitting layer 1311A and the second light-emitting layer 1311B to match the material properties of the light-emitting layer of the first light-emitting device 101, thereby improving the consistency of the light extraction efficiency and lifespan of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103.

[0236] In some embodiments, as shown in FIG9, in the second light-emitting device 102, the dimension E3 of the third light-emitting layer 1312A along the first direction X is smaller than the dimension b2 of the second hole transport functional layer 182 along the first direction X; the dimension E4 of the fourth light-emitting layer 1312B along the first direction X is smaller than the dimension b5 of the fourth hole transport functional layer 172 along the first direction X.

[0237] Understandably, through the above settings, the thicknesses of the third light-emitting layer 1312A and the fourth light-emitting layer 1312B can be kept within a suitable range, making the thicknesses of the third light-emitting layer 1312A and the fourth light-emitting layer 1312B relatively moderate. Firstly, this allows the dimensions E4 of the third light-emitting layer 1312A and the fourth light-emitting layer 1312B along the first direction X to be better matched with the material properties of the light-emitting layer of the second light-emitting device 100. Secondly, it can form a light-emitting buffer zone of a certain thickness, which can prevent the recombination region of holes and electrons in the second light-emitting device 102 from shifting away from the light-emitting layer.

[0238] In some embodiments, as shown in FIG10, in the third light-emitting device 103, the dimension E5 of the fifth light-emitting layer 1313A along the first direction X is smaller than the dimension f7 of the fifth electron transport functional layer 195 along the first direction; the dimension E6 of the sixth light-emitting layer 1313B along the first direction X is smaller than the dimension f6 of the second electron transport functional layer 192 along the first direction.

[0239] Understandably, through the above settings, the thickness of the fifth light-emitting layer 1313A and the sixth light-emitting layer 1313B can be within a suitable range. Firstly, the dimension E6 of the fifth light-emitting layer 1313A and the sixth light-emitting layer 1313B along the first direction X can be better matched with the material properties of the light-emitting layer of the third light-emitting device 103. Secondly, the thickness of the fifth light-emitting layer 1313A and the sixth light-emitting layer 1313B can be larger, which can form a larger light-emitting buffer zone and prevent the recombination region of holes and electrons in the third light-emitting device 103 from shifting away from the light-emitting layer.

[0240] In some embodiments, as shown in Figures 7B to 11, the charge generation unit 14 includes a first charge generation layer 143 and a second charge generation layer 144 stacked along a first direction X. The first charge generation layer 143 is closer to the first electrode 15 than the second charge generation layer 144. The second charge generation layer 144 has a fourth thickness D2 along the first direction X.

[0241] For example, the first charge generation layer 143 can be an electron generation layer NCGL, and the second charge generation layer 144 can be a hole generation layer PCGL; or, the first charge generation layer 143 can be a hole generation layer PCGL, and the second charge generation layer 144 can be an electron generation layer NCGL. Here, the description of the electron generation layer NCGL and the hole generation layer PCGL can be referred to the foregoing exemplary description of the electron generation layer NCGL and the hole generation layer PCGL, and will not be repeated here.

[0242] In some embodiments, as shown in FIG8, in the first light-emitting device 101, the ratio between the second thickness A1 and the sum of the third thickness A2 and the fourth thickness D21 ranges from 1.0 to 2.0.

[0243] That is, in the first light-emitting device 101, the second thickness A1, the third thickness A2, and the fourth thickness D21 satisfy the following:

[0244] In some embodiments, in the first light-emitting device 101, the ratio between the second thickness A1 and the sum of the third thickness A2 and the fourth thickness D21 ranges from 1.6 to 1.8.

[0245] For example, the ratio between the second thickness A1 and the sum of the third thickness A2 and the fourth thickness D21 can be 1.0, 1.2, 1.5, 1.6, 1.8 or 2.0, etc.

[0246] Understandably, firstly, the first thickness D can control the injection and transport rate of charge carriers (e.g., holes) transmitted to the first light-emitting layer 1311A, and the sum of the third thickness A2 and the fourth thickness D21 can control the injection and transport rate of charge carriers (e.g., holes) transmitted to the second light-emitting layer 1311B. Through this arrangement, the recombination region of holes and electrons can be located in either the first light-emitting layer 1311A or the second light-emitting layer 1311B, thus avoiding the impact on device lifetime when charge carriers recombine in regions other than the first light-emitting layer 1311A and the second light-emitting layer 1311B, thereby improving the device lifetime of the first light-emitting device 101. Secondly, the microcavity distance of the first light-emitting device 101 can be kept within a suitable range to achieve a stronger microcavity effect, thereby improving the light extraction efficiency of the first light-emitting device 101. Moreover, when the first functional unit 18 and the second functional unit 17 are hole transport units, the above arrangement allows for adjustment of the hole injection and transport rate, thereby improving luminous efficiency and device lifetime.

[0247] In some embodiments, as shown in FIG9, in the second light-emitting device 102, the ratio between the second thickness B1 and the sum of the third thickness B2 and the fourth thickness D22 ranges from 1.0 to 2.0.

[0248] That is, in the second light-emitting device 102, the second thickness B1, the third thickness B2, and the fourth thickness D22 satisfy the following:

[0249] In some embodiments, in the second light-emitting device 102, the ratio between the second thickness B1 and the sum of the third thickness B2 and the fourth thickness D22 ranges from 1.8 to 2.0.

[0250] For example, the ratio between the second thickness B1 and the sum of the third thickness B2 and the fourth thickness D22 can be 1.0, 1.2, 1.4, 1.7, 1.8 or 2.0, etc.

[0251] Similarly, through the above arrangement, the recombination region of holes and electrons can be located in the third light-emitting layer 1312A or the fourth light-emitting layer 1312B, which can improve the device lifetime of the second light-emitting device 102; at the same time, a stronger microcavity effect can be achieved, thereby improving the light extraction efficiency of the second light-emitting device 102. Moreover, when the first functional unit 18 and the second functional unit 17 are hole transport units, both luminous efficiency and device lifetime can be improved.

[0252] In some embodiments, as shown in FIG10, in the third light-emitting device 103, the ratio between the second thickness F1 and the sum of the third thickness F2 and the fourth thickness D23 ranges from 1.0 to 3.0.

[0253] That is, in the third light-emitting device 103, the second thickness F1, the third thickness F2, and the fourth thickness D23 satisfy the following:

[0254] In some embodiments, in the third light-emitting device 103, the ratio between the sum of the second thickness F1 and the third thickness F2 and the fourth thickness D23 ranges from 2.05 to 2.15.

[0255] For example, the ratio between the second thickness F1 and the sum of the third thickness F2 and the fourth thickness D23 can be 1.0, 1.4, 1.8, 2.2, 2.8 or 3.0, etc.

[0256] Similarly, through the above arrangement, the recombination region of holes and electrons can be located in the fifth light-emitting layer 1313A or the sixth light-emitting layer 1313B, which can improve the device lifetime of the third light-emitting device 103; at the same time, a stronger microcavity effect can be achieved, thereby improving the light extraction efficiency of the third light-emitting device 103. Moreover, when the first functional unit 18 and the second functional unit 17 are hole transport units, the luminous efficiency and device lifetime can be improved.

[0257] In some embodiments, as shown in FIG9, in the second light-emitting device 102 (e.g., a light-emitting device emitting green light), the second thickness B1 is greater than the sum of the third thickness B2 and the fourth thickness D22; there is a first difference B1-(B2+D22) between the second thickness B1 and the sum of the third thickness B2 and the fourth thickness D22; the ratio between the first difference B1-(B2+D22) and the wavelength λ2 of the second color light is in the range of 0.1 to 0.2.

[0258] That is, in the second light-emitting device 102, the second thickness B1, the third thickness B2, the fourth thickness D22, and the wavelength λ2 of the second color light satisfy the following:

[0259] For example, the ratio between the first difference and the wavelength of the second color light can be 0.1, 0.12, 0.14, 0.16, 0.19, or 0.2, etc.

[0260] With the above settings, the microcavity distance of the second light-emitting device 102 can be better matched with the wavelength of the second color light. In this way, more light can be transmitted through the light-emitting side electrode (e.g., the second electrode), thereby improving the luminous efficiency of the second light-emitting device 102.

[0261] In some embodiments, as shown in FIG10, in the third light-emitting device 103 (e.g., a light-emitting device emitting red light), the second thickness F1 is greater than the sum of the third thickness F2 and the fourth thickness D23; there is a second difference F1-(F2+D23) between the second thickness F1 and the sum of the third thickness F2 and the fourth thickness D23; the ratio between the second difference F1-(F2+D23) and the wavelength λ3 of the third color light is in the range of 0.1 to 0.2.

[0262] That is, in the third light-emitting device 103, the second thickness F1, the third thickness F2, the fourth thickness D23, and the wavelength λ3 of the third color light satisfy the following:

[0263] For example, the ratio between the second difference and the wavelength λ3 of the third color light can be 0.1, 0.13, 0.14, 0.16, 0.18 or 0.2, etc.

[0264] With the above settings, the microcavity distance of the third light-emitting device 103 can be better matched with the wavelength of the third color light. In this way, more light can be transmitted through the light-emitting side electrode (e.g., the second electrode), thereby improving the luminous efficiency of the third light-emitting device 103.

[0265] In some embodiments, as shown in Figures 7B to 11, the charge generating unit 14 includes a first charge generating layer 143 and a second charge generating layer 144 stacked along a first direction X. The first charge generating layer 143 is closer to the first electrode 15 than the second charge generating layer 144. The second charge generating layer 144 has a fourth thickness along the first direction X. The sum of the second thicknesses A1+B1+F1 corresponding to the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 is a sixth thickness. The sum of the third thicknesses A2+B2+F2 corresponding to the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 is a seventh thickness. The sum of the fourth thicknesses D21+D22+D23 corresponding to the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 is an eighth thickness. The ratio between the sixth thickness and the sum of the seventh and eighth thicknesses ranges from 1.0 to 2.0.

[0266] In some examples, the second charge-generating layer 144 is a common film layer shared by the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103. In this case, the fourth thickness D21 corresponding to the first light-emitting device 101, the fourth thickness D22 corresponding to the second light-emitting device 102, and the fourth thickness D23 corresponding to the third light-emitting device 103 are all equal, that is: D21=D22=D23=D2. At this time, the sixth thickness and the sum of the seventh and eighth thicknesses satisfy the following:

[0267] In other examples, the second charge generating layer 144 of the first light-emitting device 101, the second charge generating layer 144 of the second light-emitting device 102, and the second charge generating layer 144 of the third light-emitting device 103 are independently configured. In this case, the fourth thickness D21 corresponding to the first light-emitting device 101, the fourth thickness D22 corresponding to the second light-emitting device 102, and the fourth thickness D23 corresponding to the third light-emitting device 103 may not be equal. In this case, the sixth thickness and the sum of the seventh and eighth thicknesses satisfy the following:

[0268] For example, the ratio between the sixth thickness and the sum of the seventh thickness and the eighth thickness can be 1.0, 1.2, 1.4, 1.5, 1.8 or 2.0, etc.

[0269] Similarly, through the above arrangement, the recombination region of holes and electrons can be located in the light-emitting layer, which can improve the device life of the light-emitting device 100; at the same time, a strong microcavity effect can be achieved, which can improve the light emission efficiency of the light-emitting device 100 and improve the light emission efficiency of the display substrate 200.

[0270] In some embodiments, as shown in Figures 7B to 11, the charge generating unit 14 includes a first charge generating layer 143 and a second charge generating layer 144 stacked along a first direction X. The first charge generating layer 143 is closer to the first electrode 15 than the second charge generating layer 144. The first charge generating layer 143 has a fifth thickness D1 along the first direction X, and the fifth thickness D1 ranges from... The second charge-generating layer 144 has a fourth thickness D2 along the first direction X; the range of the fourth thickness D2 is within... That is to say:

[0271] In some embodiments, as shown in Figures 7B to 11, the charge generating unit 14 includes a first charge generating layer 143 and a second charge generating layer 144 stacked along a first direction X. The first charge generating layer 143 is closer to the first electrode 15 than the second charge generating layer 144. The first charge generating layer 143 has a fifth thickness D1 along the first direction X, and the fifth thickness D1 ranges from... The second charge-generating layer 144 has a fourth thickness D2 along the first direction X; the range of the fourth thickness D2 is within... That is to say:

[0272] For example, the fifth thickness D1 can be or wait.

[0273] For example, the fourth thickness D2 can be or wait.

[0274] As mentioned above, the above settings can make the range of the fifth thickness D1 and / or the fourth thickness D2 reasonable. First, it can avoid insufficient injection of electrons and holes, resulting in a lower driving voltage for the light-emitting device 100. Second, it can avoid deviations between the injection amounts of electrons and holes, allowing electrons and holes to recombine in the light-emitting region of the light-emitting unit, thereby improving the luminous efficiency and lifespan of the light-emitting device 100. Third, it can make the transmittance of the first charge generation layer 143 and / or the second charge generation layer 144 higher, thereby improving the luminous efficiency of the light-emitting device 100.

[0275] In some embodiments, as shown in Figures 7B to 11, the ratio between the distance between the surface of the selected light-emitting layer away from the first electrode 15 and the surface of the first electrode 15 near the selected light-emitting layer, and the wavelength of the selected color light (hereinafter referred to as the seventh ratio), is greater than or equal to (4n+1) / 8 and less than or equal to (4n+3) / 8; n is 0 or a positive integer; wherein, the selected light-emitting layer is any one of the first light-emitting layer 1311A, the second light-emitting layer 1311B, the third light-emitting layer 1312A, the fourth light-emitting layer 1312B, the fifth light-emitting layer 1313A, and the sixth light-emitting layer 1313B; the selected color light is the light corresponding to the selected light-emitting layer among the first color light, the second color light, and the third color light.

[0276] For example, the seventh ratio can be 0.125, 0.20, 0.28, 0.375, 0.625, 0.75, 0.875, 1.125, 1.245, 1.375, 1.625, 1.75, 1.875, 2.125, 2.255, 2.375, 2.625, 2.75, 2.875, 3.125, 3.235, or 3.375, etc.

[0277] In some examples, as shown in Figure 8, the distance L1 between the surface of the first light-emitting layer 1311A away from the first electrode 15 and the surface of the first electrode 15 near the first light-emitting layer 1311A, and the wavelength λ1 of the first color light, satisfy the following: (4n+1) / 8≤L1 / λ1≤(4n+3) / 8, where n is 0 or a positive integer.

[0278] In some examples, as shown in Figure 8, the distance L2 between the surface of the second light-emitting layer 1311B away from the first electrode 15 and the surface of the first electrode 15 near the second light-emitting layer 1311B, and the wavelength λ1 of the first color light, satisfy the following: (4n+1) / 8≤L2 / λ1≤(4n+3) / 8, where n is 0 or a positive integer.

[0279] In some examples, as shown in Figure 9, the distance L3 between the surface of the third light-emitting layer 1312A away from the first electrode 15 and the surface of the first electrode 15 near the third light-emitting layer 1312A, and the wavelength λ2 of the second color light, satisfy the following: (4n+1) / 8≤L3 / λ2≤(4n+3) / 8, where n is 0 or a positive integer.

[0280] In some examples, as shown in Figure 9, the distance L4 between the surface of the fourth light-emitting layer 1312B away from the first electrode 15 and the surface of the first electrode 15 near the fourth light-emitting layer 1312B, and the wavelength λ2 of the second color light, satisfy the following: (4n+1) / 8≤L4 / λ2≤(4n+3) / 8, where n is 0 or a positive integer.

[0281] In some examples, as shown in Figure 10, the distance L5 between the surface of the fifth light-emitting layer 1313A away from the first electrode 15 and the surface of the first electrode 15 near the fifth light-emitting layer 1313A, and the wavelength λ3 of the first color light, satisfy the following: (4n+1) / 8≤L5 / λ3≤(4n+3) / 8, where n is 0 or a positive integer.

[0282] In some examples, as shown in Figure 10, the distance L6 between the surface of the sixth light-emitting layer 1313B away from the first electrode 15 and the surface of the first electrode 15 near the sixth light-emitting layer 1313B, and the wavelength λ3 of the first color light, satisfies the following: (4n+1) / 8≤L6 / λ3≤(4n+3) / 8, where n is 0 or a positive integer.

[0283] In some examples, the first electrode 15 is a reflective anode, in which case the light-emitting device 100 is a positively positioned light-emitting device; in other examples, the first electrode 15 is a reflective cathode, in which case the light-emitting device 100 is an inverted light-emitting device.

[0284] In some examples, as shown in Figures 7B to 10, the second electrode 16 is closer to the light-emitting side 100A of the light-emitting device 100 relative to the first electrode 15; the first electrode 15 is closer to the substrate 210 relative to the second electrode 16. In this case, the light-emitting device 100 is a top-emitting type light-emitting device.

[0285] Understandably, the light emitted by the selected light-emitting layer includes light emitted towards the side near the first electrode 15 (hereinafter referred to as the first light) and light emitted towards the side near the second electrode 16 (hereinafter referred to as the second light). Moreover, when the first electrode 15 is a reflective electrode, the first light can be reflected by the first electrode 15. Therefore, by the above arrangement, the seventh ratio can be kept within a suitable range, and constructive interference can be generated between the second light and the light after the first light is reflected by the first electrode 15, thereby improving the light extraction efficiency of the light-emitting device 100.

[0286] In some embodiments, as shown in Figures 7B to 11, the first electrode 15 is the anode; the first functional unit 18 includes a first hole transport functional layer 183, a second hole transport functional layer 182, and a third hole transport functional layer 181 arranged in a direction away from the first electrode 15; the second functional unit 17 includes a fourth hole transport functional layer 172 and a fifth hole transport functional layer 171 arranged in a direction away from the charge generation unit 14.

[0287] In some examples, the first hole transport functional layer 183 can be a hole injection layer HIL; the second hole transport functional layer 182 can be a hole transport layer HTL; and the third hole transport functional layer 181 can be an electron blocking layer EBL.

[0288] In some examples, the fourth hole transport functional layer 172 can be a hole transport layer HTL, and the fifth hole transport functional layer 171 can be an electron blocking layer EBL.

[0289] In this case, as shown in Figures 8 to 10, the second thickness A1 is the sum of the dimensions of the first hole transport functional layer 183 along the first direction X, the second hole transport functional layer 182 along the first direction X, and the third hole transport functional layer 181 along the first direction X; the third thickness A2 is the sum of the dimensions of the fourth hole transport functional layer 172 along the first direction X and the fifth hole transport functional layer 171 along the first direction X. Understandably, through the above configuration, the second thickness can be relatively large, and the number of first functional units 17 in the first light-emitting unit 13A can be increased. This can slow down the carrier transport rate between the first electrode 15 and the first light-emitting layer 1311A, the third light-emitting layer 1312A, or the fifth light-emitting layer 1313A, allowing holes in the first light-emitting unit 13A and the second light-emitting unit 13B to be smoothly transported to their corresponding light-emitting layers. This allows electrons and holes to recombine within the light-emitting layers, matching the amount of holes and electrons within the light-emitting layers. This can improve the exciton generation rate and prevent excitons from accumulating in areas other than the light-emitting layers, thereby improving the efficiency and lifespan of the light-emitting device 100. It can also improve the consistency of the light extraction efficiency and lifespan of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103.

[0290] In some embodiments, as shown in FIG9, in the second light-emitting device 102, there is a first distance B3 between the third hole transport functional layer 181 and the charge generating unit 14; the sum of the dimension b1 of the third hole transport functional layer 181 along the first direction X and the first distance B3 is less than or equal to the sum of the dimensions b2+b3 of the first hole transport functional layer 183 and the second hole transport functional layer 182 along the first direction X. That is: b1+B3≤b2+b3.

[0291] In some examples, as shown in Figure 9, in the second light-emitting device 102, the first light-emitting unit 13A further includes a multilayer electron transport functional layer located between the charge generating unit 14 and the third light-emitting layer 1312A. The multilayer electron transport functional layer includes, for example, a fourth electron transport functional layer 194 and a fifth electron transport functional layer 195. The fourth electron transport functional layer 194 can be a hole blocking layer, and the fifth electron transport functional layer 195 can be an electron transport layer.

[0292] In this case, the first distance B3 is the sum of the thickness E3 of the third light-emitting layer 1312A, the thickness of the fourth electron transport functional layer 194, and the thickness of the fifth electron transport functional layer 195.

[0293] In some examples, as shown in Figures 12 to 15, the thickness of the fifth electron transport functional layer 195 can be 0, that is, the charge generation unit 14 and the third light-emitting layer 1312A can be separated only by the fourth electron transport functional layer 194.

[0294] For example, the sum of the dimension B1 and the first distance B3 of the third hole transport functional layer 181 along the first direction X can be... or wait.

[0295] For example, the sum of the dimensions of the first hole transport functional layer 183 and the second hole transport functional layer 182 along the first direction X can be or wait.

[0296] In some embodiments, in the second light-emitting device 102, the ratio between the sum of the dimension b1 of the third hole transport functional layer 181 along the first direction X and the first distance B3, and the sum of the dimensions b2+b3 of the first hole transport functional layer 183 and the second hole transport functional layer 182 along the first direction X. The range is 0.70 to 0.85.

[0297] For example, in the second light-emitting device 102, the ratio between the sum of the dimension b1 of the third hole transport functional layer 181 along the first direction X and the first distance B3, and the sum of the dimensions b2+b3 of the first hole transport functional layer 183 and the second hole transport functional layer 182 along the first direction X. It can be 0.10, 0.30, 0.52, 0.70, 0.80, 0.85, 0.90 or 1.00, etc.

[0298] Understandably, through the above settings, the thickness of the first functional unit 18 in the second light-emitting device 102 can be relatively thick, so that the microcavity length of the second light-emitting device 102 is more matched with the wavelength of the second color light. In this way, a stronger microcavity effect can be achieved, thereby improving the luminous efficiency of the second light-emitting device 102.

[0299] In some embodiments, as shown in FIG8, in the first light-emitting device 101, the third hole transport functional layer 1811 has a size a1 ranging from 5nm to 10nm along the first direction X; the fifth hole transport functional layer 171 has a size a4 ranging from 5nm to 10nm along the first direction X.

[0300] For example, the dimension a1 of the third hole transport functional layer 181 along the first direction X can be 5nm, 6nm, 7nm, 8.5nm, 9nm or 10nm, etc.

[0301] For example, the dimension a4 of the fifth hole transport functional layer 171 along the first direction X can be 5nm, 6.5nm, 7nm, 8nm, 9nm or 10nm, etc.

[0302] In some embodiments, as shown in FIG9, in the second light-emitting device 102, the dimension b1 of the third hole transport functional layer 181 along the first direction X ranges from 40nm to 45nm. The dimension b4 of the fifth hole transport functional layer 171 along the first direction X ranges from 15nm to 20nm.

[0303] For example, the dimension b1 of the third hole transport functional layer 181 along the first direction X can be 40nm, 41nm, 42nm, 43.5nm, 44nm or 45nm, etc.

[0304] For example, the dimension b4 of the fifth hole transport functional layer 171 along the first direction X can be 15nm, 16.5nm, 17nm, 18nm, 19nm or 20nm, etc.

[0305] In some embodiments, as shown in FIG10, in the third light-emitting device 103, the size f1 of the third hole transport functional layer 181 along the first direction X ranges from 80nm to 95nm. The size f4 of the fifth hole transport functional layer 171 along the first direction X ranges from 25nm to 35nm.

[0306] For example, the size f1 of the third hole transport functional layer 181 along the first direction X can be 80nm, 83nm, 86nm, 89nm, 94nm or 95nm, etc.

[0307] For example, the size f4 of the fifth hole transport functional layer 171 along the first direction X can be 25nm, 28nm, 29nm, 31nm, 33nm or 35nm, etc.

[0308] Understandably, firstly, through the above-mentioned configuration, the thicknesses of the fifth hole transport functional layer 171 and the third hole transport functional layer 181 of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 can be set differently, and the thicknesses of the first functional unit 18 and the second functional unit 17 in the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 can be set differently. In this way, the microcavity distance of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 can be within a suitable range, and a stronger microcavity effect can be achieved. Thus, the light emission efficiency of the light-emitting device 100 can be improved. Secondly, through the above-mentioned configuration, the recombination region of holes and electrons can be located in the light-emitting layer, which can improve the device lifespan of the light-emitting device 100. Thirdly, the third hole transport functional layer 181 of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 can be independently configured, and the fifth hole transport functional layer 171 of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 can be independently configured. The materials of the third hole transport functional layer 181 and the fifth hole transport functional layer 171 with matching performance can be selected as needed according to the different materials of the light-emitting layers.

[0309] In some embodiments, as shown in FIG7B, the size of the first hole transport functional layer 183 along the first direction X ranges from 5nm to 15nm.

[0310] For example, the size of the first hole transport functional layer 183 along the first direction X can be 5nm, 7nm, 9nm, 11nm, 13nm or 15nm, etc.

[0311] In some embodiments, as shown in FIG7B, the size of the second hole transport functional layer 182 along the first direction X ranges from 95nm to 105nm.

[0312] For example, the size of the second hole transport functional layer 182 along the first direction X can be 95nm, 97nm, 99nm, 101nm, 103nm or 105nm, etc.

[0313] In some embodiments, as shown in FIG7B, the size of the fourth hole transport functional layer 172 along the first direction X ranges from 50nm to 60nm.

[0314] For example, the size of the fourth hole transport functional layer 172 along the first direction X can be 50nm, 52nm, 54nm, 56nm, 58nm or 60nm, etc.

[0315] Understandably, through the above configuration, electrons and holes of the first light-emitting unit 13A can recombine in the first light-emitting layer 1311A, the third light-emitting layer 1312A, or the fifth light-emitting layer 1313A, and electrons and holes of the second light-emitting unit 13B can recombine in the second light-emitting layer 1311B, the fourth light-emitting layer 1312B, or the sixth light-emitting layer 1313B, thereby improving the efficiency and lifespan of the light-emitting device 100.

[0316] In some embodiments, as shown in Figures 7B to 11, the material of the selected light-emitting layer includes a host material and a guest material; the doping ratio of the guest material in the material of the selected light-emitting layer is greater than 0 and less than or equal to 10%; wherein, the selected light-emitting layer is any one of the first light-emitting layer 1311A, the second light-emitting layer 1311B, the third light-emitting layer 1312A, the fourth light-emitting layer 1312B, the fifth light-emitting layer 1313A, and the sixth light-emitting layer 1313B; the guest materials contained in any two of the first light-emitting layer 1311A, the second light-emitting layer 1311B, the third light-emitting layer 1312A, the fourth light-emitting layer 1312B, the fifth light-emitting layer 1313A, and the sixth light-emitting layer 1313B may be the same or different.

[0317] For a description of the subject material and the object material, please refer to the foregoing exemplary description of the subject material and the object material. Furthermore, the subject materials contained in any two of the first light-emitting layer 1311A, the second light-emitting layer 1311B, the third light-emitting layer 1312A, the fourth light-emitting layer 1312B, the fifth light-emitting layer 1313A, and the sixth light-emitting layer 1313B may be the same or different.

[0318] For example, the doping ratio of the guest material in the selected light-emitting layer material can be 2%, 4%, 5%, 6%, 8%, or 10%, etc.

[0319] Understandably, a high doping ratio of the guest material in the selected light-emitting layer may cause exciton quenching, resulting in exciton loss and lower efficiency of the light-emitting device 100. Therefore, by setting the doping ratio of the guest material in the selected light-emitting layer to be greater than 0 and less than or equal to 10%, the light-emitting efficiency of the light-emitting device 100 can be improved.

[0320] In some embodiments, as shown in Figures 7B and 11, the doping ratio of the guest material contained in the fifth light-emitting layer 1313A in the material of the fifth light-emitting layer 1313A is less than or equal to the doping ratio of the guest material contained in the third light-emitting layer 1312A in the material of the third light-emitting layer 1312A, and less than or equal to the doping ratio of the guest material contained in the fourth light-emitting layer 1312B in the material of the fourth light-emitting layer 1312B; the doping ratio of the guest material contained in the sixth light-emitting layer 1313B in the material of the sixth light-emitting layer 1313B is less than or equal to the doping ratio of the guest material contained in the third light-emitting layer 1312A in the material of the third light-emitting layer 1312A, and less than or equal to the doping ratio of the guest material contained in the fourth light-emitting layer 1312B in the material of the fourth light-emitting layer 1312B.

[0321] In some examples, the doping ratio of the guest material contained in the fifth light-emitting layer 1313A in the material of the fifth light-emitting layer 1313A is less than or equal to the doping ratio of the guest material contained in the first light-emitting layer 1311A in the material of the first light-emitting layer 1311A, and less than or equal to the doping ratio of the guest material contained in the second light-emitting layer 1311B in the material of the second light-emitting layer 1311B; the doping ratio of the guest material contained in the sixth light-emitting layer 1313B in the material of the sixth light-emitting layer 1313B is less than or equal to the doping ratio of the guest material contained in the first light-emitting layer 1311A in the material of the first light-emitting layer 1311A, and less than or equal to the doping ratio of the guest material contained in the second light-emitting layer 1311B in the material of the second light-emitting layer 1311B.

[0322] Understandably, the energy level of the guest material used to emit a third color light (e.g., red light) is relatively low, resulting in relatively high luminous efficiency. Furthermore, the guest material used to emit a third color light (e.g., red light) is more prone to exciton quenching. With the above configuration, the content of guest material in the luminescent layer of the third light-emitting device 103 is less than the content in the luminescent layer of the second light-emitting device 102. This reduces exciton quenching during the luminescence process of the third light-emitting device 103, resulting in higher luminous efficiency.

[0323] In some embodiments, as shown in FIG11, the charge generating unit 14 includes a first charge generating layer 143 and a second charge generating layer 144 stacked along a first direction X. The first charge generating layer 143 is closer to the first electrode 15 than the second charge generating layer 144. The material of the first charge generating layer 143 includes a first matrix material and an N-type dopant. The material of the second charge generating layer 144 includes a second matrix material and a P-type dopant. The ratio between the doping ratio Xn of the N-type dopant in the material of the first charge generating layer 143 and the doping ratio Xp of the P-type dopant in the material of the second charge generating layer 144 is greater than or equal to 0.01 and less than or equal to 0.2. That is, Xn ≤ 0.2Xp.

[0324] For example, the ratio of the doping ratio Xn of the N-type dopant in the material of the first charge generation layer 143 to the doping ratio Xp of the P-type dopant in the material of the second charge generation layer 144 can be 0.01, 0.05, 0.10, 0.14, 0.18, or 0.2.

[0325] For example, the first matrix material can be an organic material, such as one or any combination of tri-8-hydroxyquinoline aluminum, triazine, hydroxyquinoline derivatives, indole derivatives and thiophene derivatives.

[0326] For example, the N-type dopant can be an alkali metal, an alkali metal compound, an alkaline earth metal, or an alkaline earth metal compound, such as one or any combination of lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Fs), magnesium (Mg), calcium (Ga), strontium (Sr), barium (Ba), lanthanum (La), cerium (Fe), samarium (Sm), europium (Eu), terbium (Tb), dysprosium (Dy), and ytterbium (Yb).

[0327] For example, the first matrix material can be an organic material, such as one or any combination of N,N′-di(naphthyl-1-yl)-N,N′-diphenyl-benzidine (NPB), N,N′-diphenyl-N,N′-bis(3-methylphenyl)-(1,1′-biphenyl)-4,4′-diamine (TPD), and N,N,N′,N′-tetranaphthylbenzidine (TNB).

[0328] For example, the P-type dopant can be a metal or an organic material. When the P-type dopant is a metal, the metal can be selected from one or any combination of aluminum (Al), copper (Fu), iron (Fe), lead (Pb), zinc (Zn), gold (Au), platinum (Pt), tungsten (W), indium (In), molybdenum (Mo), nickel (Ni), and titanium (Ti). When the P-type dopant is an organic material, the P-type dopant can be one or any combination of 2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-p-quinone dimethane (F4-TFNQ) and 7,7,8,8-tetracyano-p-quinone dimethane (TFNQ) derivatives.

[0329] Understandably, through the above settings, the doping ratio Xn of the N-type dopant in the material of the first charge generation layer 143 can be matched with the electron transport performance of the N-type dopant, and the doping ratio Xp of the P-type dopant in the material of the second charge generation layer 144 can be matched with the hole transport performance of the P-type dopant. This allows electrons and holes in the first light-emitting unit 13A and the second light-emitting unit 13B to recombine in the light-emitting layer, which is beneficial to improving the efficiency and lifespan of the light-emitting device 100.

[0330] In some embodiments, the doping ratio Xn of the N-type dopant in the material of the first charge generation layer 143 is greater than or equal to 0 and less than or equal to 5%.

[0331] For example, the doping ratio Xn of the N-type dopant in the first charge generation layer 143 can be 0%, 1%, 2%, 3.2%, 4%, or 5%, etc.

[0332] Understandably, a higher doping level of N-type dopant in the material of the first charge generation layer 143 can increase the electron generation and / or electron injection levels, and affect the electron diffusion rate (which can be called drift rate) and / or electron diffusion distance, resulting in higher electron generation and transport efficiency. However, this can lead to two problems: firstly, electrons or excitons may accumulate in areas other than the light-emitting layer, affecting the lifetime of the light-emitting device; secondly, it can increase the conductivity of the first charge generation layer 143, making it easier to generate lateral currents and cause color crosstalk. Therefore, through the above settings, the electron generation and transport efficiency can be kept within a suitable range, allowing electrons and holes to recombine in the light-emitting layer, thereby improving the lifetime of the light-emitting device 100 and avoiding color crosstalk.

[0333] In some embodiments, the doping ratio Xp of the P-type dopant in the material of the second charge generation layer 144 is greater than or equal to 0 and less than or equal to 20%.

[0334] For example, the doping ratio Xp of the P-type dopant in the second charge generation layer 144 can be 0%, 5%, 8%, 10%, 15%, or 20%, etc.

[0335] Understandably, a higher doping level of P-type dopant in the material of the second charge generation layer 144 can increase the hole generation and / or hole injection levels, and affect the hole diffusion rate (which can be called drift rate) and / or hole diffusion distance, resulting in higher hole generation and transport efficiency. However, this can lead to two problems: firstly, the recombination region of electrons and holes may deviate from the light-emitting layer, affecting the lifetime of the light-emitting device; secondly, it can increase the conductivity of the second charge generation layer 144, making it easier to generate lateral currents and cause color crosstalk. Therefore, through the above settings, the hole generation and transport efficiency can be kept within a suitable range, allowing electrons and holes to recombine in the light-emitting layer, thereby improving the lifetime of the light-emitting device 100 and avoiding color crosstalk.

[0336] In some embodiments, the wavelength of the first color light is greater than or equal to 400 nm and less than or equal to 500 nm; the wavelength of the second color light is greater than or equal to 510 nm and less than or equal to 540 nm; and the wavelength of the third color light is greater than or equal to 600 nm.

[0337] For example, the wavelength of the first color light can be 400nm, 420nm, 440nm, 460nm, 480nm, or 500nm, etc.

[0338] For example, the wavelength of the second color light can be 510nm, 516nm, 522nm, 528nm, 534nm, or 540nm, etc.

[0339] For example, the wavelength of the third color light can be 600nm, 610nm, 620nm, 630nm, 640nm, or 650nm, etc.

[0340] Understandably, through the above settings, the display substrate 200 can achieve full-color display, and at the same time, the color purity of the light emitted by the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 can be improved.

[0341] In order to objectively evaluate the technical effects of the embodiments of this disclosure, the technical solutions provided by this disclosure will be described in detail and by way of example through the following experimental examples and comparative examples.

[0342] The following embodiments and comparative examples fabricated display substrates 200 or light-emitting substrates with different film layer thicknesses. The display substrate 200 includes a first light-emitting device 101, a second light-emitting device 102, and a third light-emitting device 103. The light-emitting substrate includes either the first light-emitting device 101, the second light-emitting device 102, or the third light-emitting device 103. The structure of the display substrate 200 is shown in Figure 12, the structure of the first light-emitting device 101 in the display substrate 200 or the light-emitting substrate is shown in Figure 13, the structure of the second light-emitting device 102 in the display substrate 200 or the light-emitting substrate is shown in Figure 14, and the structure of the third light-emitting device 103 in the display substrate 200 or the light-emitting substrate is shown in Figure 15. It should be understood that, based on the structures shown in Figures 12 to 15, the thickness of the charge-generating unit 14 (i.e., the first thickness) is the sum of the thickness of the first charge-generating layer 143 (i.e., the fifth thickness) and the thickness of the second charge-generating layer 144 (i.e., the fourth thickness). The thickness of the first functional unit 18 (i.e., the second thickness) is the sum of the thicknesses of the first hole transport functional layer 183, the second hole transport functional layer 182, and the third hole transport functional layer 181. The thickness of the second functional unit 17 (i.e., the third thickness) is the sum of the thicknesses of the fourth hole transport functional layer 172 and the fifth hole transport functional layer 171. The first distance is the sum of the thickness of the light-emitting layer of the first light-emitting unit 13A and the thickness of the fourth electron transport functional layer 194.

[0343] According to the evaluation purpose of the embodiments, the following experimental examples and comparative examples are divided into the first group of experimental examples, the second group of experimental examples, the third group of experimental examples, the fourth group of experimental examples, and the fifth group of experimental examples.

[0344] [First Group of Test Cases]

[0345] The following Examples 1 to 10 describe the preparation of display substrates 200 with different film thicknesses. The structure of the display substrate 200 is shown in Figure 12.

[0346] Exemplarily, the method for fabricating a display substrate 200 including a first light-emitting device 101, a second light-emitting device 102, and a third light-emitting device 103 is as follows: a substrate 210 (glass substrate) with a patterned first electrode 15 (ITO electrode) is used as a back plate, and the back plate is placed in the vacuum chamber of a vacuum evaporation apparatus, and the vacuum is evacuated to 1×10⁻⁶. -5 Pa ~ 1×10 -6After Pa, the materials of the first hole transport functional layer 183, the second hole transport functional layer 182, the third hole transport functional layer 181, the light-emitting layer of the first light-emitting unit 13A, the fourth electron transport functional layer 194, the first charge generation layer 143, the second charge generation layer 144, the fourth hole transport functional layer 172, the fifth hole transport functional layer 171, the light-emitting layer of the second light-emitting unit 13B, the third electron transport functional layer 191, the second electron transport functional layer 192, and the first electron transport functional layer 193 are utilized. The materials of the first hole transport functional layer 183, the second hole transport functional layer 182, the third hole transport functional layer 181, the light-emitting layer of the first light-emitting unit 13A, the fourth electron transport functional layer 194, the first charge generation layer 143, the second charge generation layer 144, the fourth hole transport functional layer 172, the fifth hole transport functional layer 171, the light-emitting layer of the second light-emitting unit 13B, the third electron transport functional layer 191, the second electron transport functional layer 192, the first electron transport functional layer 193, the second electrode 16, and the cover layer CPL are sequentially formed on the back plate.

[0347] Before use, the backplate is ultrasonically treated in a cleaning agent and rinsed in deionized water. It is then ultrasonically treated sequentially in acetone and isopropanol solvents to remove oil. Afterward, it is baked in a clean environment until all moisture is removed, and then baked with an ultraviolet lamp to remove residual organic matter from the substrate surface. The light-emitting layer of the first light-emitting unit 13A includes the materials of the first light-emitting layer 1311A, the third light-emitting layer 1312A, and the fifth light-emitting layer 1313A. The light-emitting layer of the second light-emitting unit 13B includes the materials of the second light-emitting layer 1311B, the fourth light-emitting layer 1312B, and the sixth light-emitting layer 1313B. The materials of the first light-emitting layer 1311A and the second light-emitting layer 1311B are deposited in the area corresponding to the first light-emitting device 101. The materials of the third light-emitting layer 1312A and the fourth light-emitting layer 1312B are deposited in the area corresponding to the second light-emitting device 102. The materials of the fifth light-emitting layer 1313A and the sixth light-emitting layer 1313B are deposited in the area corresponding to the third light-emitting device 103.

[0348] It should be noted that in the following embodiments 1 to 10, the materials used for the first hole transport functional layer 183, the second hole transport functional layer 182, the third hole transport functional layer 181, the fourth electron transport functional layer 194, the first charge generation layer 143, the second charge generation layer 144, the fourth hole transport functional layer 172, the fifth hole transport functional layer 171, the third electron transport functional layer 191, the second electron transport functional layer 192, the first electron transport functional layer 193, the second electrode 16, and the capping layer CPL in the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 are all the same. For example, the material of the first hole transport functional layer 183 in the first light-emitting device 101 is the same as the material of the first hole transport functional layer 183 in the second light-emitting device 102, and also the same as the material of the first hole transport functional layer 183 in the third light-emitting device 103.

[0349] The first hole transport functional layer 183 is made of a hole transport material with the structure shown in formula (NPB) and a hole injection material with the structure shown in formula (HATCN), with a mass ratio of 99:1. The materials of the second hole transport functional layer 182 and the fourth hole transport functional layer 172 have the structure shown in formula (NPB). The materials of the third hole transport functional layer 181 and the fifth hole transport functional layer 171 have the structure shown in formula (TCTA). The materials of the fourth electron transport functional layer 194 and the third electron transport functional layer 191 have the structure shown in formula (PPF). The material of the first charge generation layer 143 includes a structure shown in formula (NPB). The first material and lithium (Li) are shown in the following formula (BCP), and their mass ratio is 99.5:0.5; the material of the second charge generation layer 144 includes a hole transport material with the structure shown in the following formula (NPB) and a hole injection material with the structure shown in the following formula (HATCN), and their mass ratio is 90:10; the material of the second electron transport functional layer 192 includes an electron transport material with the structure shown in the following formula (TmPypB) and Liq, and their mass ratio is 1:1; the material of the first electron transport functional layer 193 is ytterbium; the material of the second electrode 16 is a magnesium-silver alloy; the structure of the material of the capping layer CPL is shown in the following formula (CPL).

[0350] In Examples 1 to 10 below, the materials used for the light-emitting layers of the first light-emitting unit 13A and the second light-emitting unit 13B in the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 are different. Specifically, in the first light-emitting device 101, the first light-emitting layer 1311A and the second light-emitting layer 1311B are made of the same material, both comprising a main material with the structure shown in formula (mCP) and a guest material with the structure shown in formula (Flrpic), with a mass ratio of 99:1. In the second light-emitting device 102, the third light-emitting layer 1312A and the fourth light-emitting layer 1312B are made of the same material, both comprising a main material with the structure shown in formula (CBP) and a guest material with the structure shown in formula (Ir(ppy)3), with a mass ratio of 92:8. In the third light-emitting device 103, the fifth light-emitting layer 1313A and the sixth light-emitting layer 1313B are made of the same material, both including the host material with the structure shown in the following formula (DCzDBT) and the guest material with the structure shown in the following formula (Ir(piq)2(acac)), and the mass ratio of the two is 98:2.

[0351] In the following Examples 1 to 10, in the first light-emitting device 101 of the display substrate 200, the thickness of the first light-emitting layer 1311A and the second light-emitting layer 1311B are both The thicknesses of the third electron transport functional layer 191 and the fourth electron transport functional layer 194 are both The thickness of the second electron transport functional layer 192 is The thicknesses of the films other than the first light-emitting layer 1311A, the second light-emitting layer 1311B, the third electron transport functional layer 191, the fourth electron transport functional layer 194, and the second electron transport functional layer 192 are shown in Table 1.

[0352] Table 1

[0353] It should be noted that in Table 1, a1 represents the thickness of the third hole transport functional layer 1811, a2 represents the thickness of the second hole transport functional layer 182, a3 represents the thickness of the first hole transport functional layer 183, a4 represents the thickness of the fifth hole transport functional layer 1711, a5 represents the thickness of the fourth hole transport functional layer 172, and A3 represents the first distance corresponding to the first light-emitting device 101. D11 represents the thickness of the first charge generation layer 143 (i.e., the fifth thickness), D21 represents the thickness of the second charge generation layer 144 (i.e., the fourth thickness), and D represents the thickness of the charge generation unit 14 (i.e., the first thickness). Furthermore, all thicknesses shown in Table 1 are in units of...

[0354] In Examples 1 to 10 below, the thickness of the third light-emitting layer 1312A and the fourth light-emitting layer 1312B in the second light-emitting device 102 of the display substrate 200 is 100. The thicknesses of the third electron transport functional layer 191 and the fourth electron transport functional layer 194 are both The thickness of the second electron transport functional layer 192 is The thicknesses of the films other than the third light-emitting layer 1312A, the fourth light-emitting layer 1312B, the third electron transport functional layer 191, the fourth electron transport functional layer 194, and the second electron transport functional layer 192 are shown in Table 2.

[0355] Table 2

[0356] It should be noted that in Table 2, b1 represents the thickness of the third hole transport functional layer 1812, b2 represents the thickness of the second hole transport functional layer 182, b3 represents the thickness of the first hole transport functional layer 183, b4 represents the thickness of the fifth hole transport functional layer 1712, b5 represents the thickness of the fourth hole transport functional layer 172, and B3 represents the first distance corresponding to the first light-emitting device 101. D12 represents the thickness of the first charge generation layer 143 (i.e., the fifth thickness), D22 represents the thickness of the second charge generation layer 144 (i.e., the fourth thickness), and D represents the thickness of the charge generation unit 14 (i.e., the first thickness). Furthermore, all thicknesses shown in Table 2 are in units of...

[0357] In Examples 1 to 10 below, in the third light-emitting device 103 of the display substrate 200, the thickness of the fifth light-emitting layer 1313A and the sixth light-emitting layer 1313B is 100%. The thicknesses of the third electron transport functional layer 191 and the fourth electron transport functional layer 194 are both The thickness of the second electron transport functional layer 192 is The thicknesses of the films other than the third light-emitting layer 1312A, the fourth light-emitting layer 1312B, the third electron transport functional layer 191, the fourth electron transport functional layer 194, and the second electron transport functional layer 192 are shown in Table 3.

[0358] Table 3

[0359] It should be noted that in Table 3, f1 represents the thickness of the third hole transport functional layer 1813, f2 represents the thickness of the second hole transport functional layer 182, f3 represents the thickness of the first hole transport functional layer 183, f4 represents the thickness of the fifth hole transport functional layer 1713, f5 represents the thickness of the fourth hole transport functional layer 172, and F3 represents the first distance corresponding to the first light-emitting device 101. D13 represents the thickness of the first charge generation layer 143 (i.e., the fifth thickness), D23 represents the thickness of the second charge generation layer 144 (i.e., the fourth thickness), and D represents the thickness of the charge generation unit 14 (i.e., the first thickness). Furthermore, all thicknesses shown in Table 3 are in units of...

[0360] Based on the above settings, the driving voltage, luminous efficiency, and lifetime of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 in the display substrate 200 of Examples 1 to 10 were tested. The test results are shown in Table 4 below. Furthermore, in Table 4, the data results for the driving voltage, luminous efficiency, and lifetime of the first light-emitting device 101 are referenced to the first light-emitting device 101 in Comparative Example 1. The data results for the driving voltage, luminous efficiency, and lifetime of the second light-emitting device 102 are referenced to the second light-emitting device 102 in Comparative Example 1. The data results for the driving voltage, luminous efficiency, and lifetime of the third light-emitting device 103 are referenced to the third light-emitting device 103 in Comparative Example 1.

[0361] Table 4

[0362] Referring to Table 4, in Examples 1-5 and Comparative Examples 1-5, the luminous efficiency and lifespan of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device corresponding to Examples 1-5 are relatively higher than those of Comparative Examples 1-5. This is because the first thickness in Examples 1-5 is... Within the range, while the first thickness of Comparative Examples 1 to 5 is not within the range. Within the range. This indicates that when the first thickness is within... When the voltage is within the specified range, firstly, it can avoid insufficient injection of electrons and holes, resulting in lower driving voltages for the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103; secondly, it can avoid deviations between the injection amounts of electrons and holes, allowing electrons and holes to recombine in the light-emitting region of the light-emitting unit, thereby improving the luminous efficiency and lifespan of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103; and thirdly, it can achieve higher transmittance, thereby improving the luminous efficiency of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103.

[0363] Furthermore, compared to Examples 1 and 2, Examples 3 to 5 show that the luminous efficiency and lifespan of the first, second, and third light-emitting devices are relatively higher. This is because the fourth thickness D2 in Examples 3 to 5... The fourth thickness D2 in Examples 1 and 2 is not within the range. Within the range. This indicates that when the fourth thickness D2 is within... When the voltage is within the specified range, the driving voltage of the light-emitting device 100 can be lower; at the same time, the luminous efficiency and lifespan of the light-emitting device 100 can be improved.

[0364] [Second Group of Test Examples]

[0365] The following embodiments and comparative examples prepared light-emitting substrates containing a first light-emitting device 101 with different film thicknesses, wherein the structure of the first light-emitting device 101 is shown in Figure 13. The method for preparing the first light-emitting device 101 in the light-emitting substrate can be referred to the method for preparing the first light-emitting device 101 in the display substrate 200 in the first set of experimental examples, and will not be repeated here.

[0366] The materials of the first electrode 15, first hole transport functional layer 183, second hole transport functional layer 182, third hole transport functional layer 181, light-emitting layer of the first light-emitting unit 13A, fourth electron transport functional layer 194, first charge generation layer 143, second charge generation layer 144, fourth hole transport functional layer 172, fifth hole transport functional layer 171, light-emitting layer of the second light-emitting unit 13B, third electron transport functional layer 191, second electron transport functional layer 192, first electron transport functional layer 193, second electrode 16, and capping layer CPL in Examples 11-15 and Comparative Examples 1-5 are all the same. In other words, the materials of each film layer of the first light-emitting device 101 were not differentiated in Examples 11-15 and Comparative Examples 1-5. Furthermore, the materials used in the aforementioned film layers are the same as those used in the film layers of the first light-emitting device 101 in the first set of test examples. Therefore, the structure and addition ratio of the material used in the first light-emitting device 101 can be referred to the structure and addition ratio of the material of the first light-emitting device 101 in the first set of test examples, and will not be repeated here.

[0367] In Examples 11 to 15 and Comparative Examples 6 to 10 below, the thickness E1 of the first light-emitting layer 1311A is... The thickness E2 of the second light-emitting layer 1311B is The thickness D11 of the first charge generation layer 143 is... The thickness D21 of the second charge generation layer 144 is always... The thicknesses of some of the other film layers, excluding the first light-emitting layer 1311A, the second light-emitting layer 1311B, the first charge-generating layer 143, and the second charge-generating layer 144, are shown in Table 5.

[0368] Table 5

[0369] It should be noted that in Table 5, a1 represents the thickness of the third hole transport layer 1811, a2 represents the thickness of the second hole transport layer 182, a3 represents the thickness of the first hole transport layer 183, a4 represents the thickness of the fifth hole transport layer 1711, a5 represents the thickness of the fourth hole transport layer 172, and A3 represents the first distance. Furthermore, all thicknesses shown in Table 5 are in units of...

[0370] To more clearly describe the relationship between the first thickness D of the charge generation layer 14 along the first direction X, the fourth thickness D21 of the second charge generation layer 144 along the first direction X, the second thickness A1, and the third thickness A2 in the embodiments and comparative examples, Table 6 below is used to more clearly show the relationship between the film thicknesses set in the embodiments and comparative examples.

[0371] Table 6

[0372] It should be noted that the values ​​in Table 6 refer to the values ​​of the corresponding relational expressions. For example, the content of the cell corresponding to the first ratio in Example 11 is "4.30", which means that in Example 1, the first ratio calculated from the second thickness A1 and the first thickness D is 4.30. The meanings of the second thickness A1, the third thickness A2, the first thickness D, and the fourth thickness D21 can be found in the foregoing content and will not be repeated here.

[0373] Based on the above settings, the driving voltage (V), luminous efficiency (%), and lifetime of the first light-emitting device 101 in Examples 11 to 15 and Comparative Examples 6 to 10 were tested. The test results are shown in Table 7 below. The data for driving voltage (V), luminous efficiency (%), and lifetime in Table 7 are based on Comparative Example 6.

[0374] Table 7

[0375] Compared with Comparative Examples 6 to 10, Examples 11 to 15 (see Table 7) exhibit relatively lower driving voltages, higher luminous efficiency, and longer lifetimes. This is because the first ratio in Examples 11 to 15 is within the range of 4.0 to 5.0, and the second ratio is within the range of 2.0 to 3.0, while in Comparative Examples 6 to 10, the first ratio is not within the range of 4.0 to 5.0, and the second ratio is not within the range of 2.0 to 3.0. Specifically, when the first ratio is within the range of 4.0 to 5.0, and the second ratio is within the range of 2.0 to 3.0, the recombination region of holes and electrons can be located in the first luminescent layer 1311A and the second luminescent layer 1311B. This prevents carrier recombination in regions other than the first luminescent layer 1311A and the second luminescent layer 1311B, thereby improving the lifetime of the first light-emitting device 101. Moreover, when the first ratio is in the range of 4.0 to 5.0 and the second ratio is in the range of 2.0 to 3.0, the microcavity distance of the first light-emitting device 101 can be within a suitable range to achieve a stronger microcavity effect and improve the light emission efficiency of the first light-emitting device 101.

[0376] Furthermore, the luminous efficiency and lifetime of the first light-emitting device 101 in Comparative Examples 9 and 10 are relatively low. This may be because in Comparative Example 4, the second thickness A1 is smaller than the third thickness A2, and in Comparative Examples 9 and 10, the ratio between the second thickness A1 and the sum of the third thickness A2 and the fourth thickness D21 is less than 1.0. This indicates that when the second thickness A1 is greater than the third thickness A2, the carrier transport rate between the first electrode 15 and the first light-emitting layer 1311A can be slowed down, allowing electrons and holes to recombine within the light-emitting layer, thereby improving the efficiency and lifetime of the light-emitting device 100. It also indicates that when the ratio between the second thickness A1 and the sum of the third thickness A2 and the fourth thickness D21 is in the range of 1.0 to 2.0, the recombination region of holes and electrons can be located in the first light-emitting layer 1311A and the second light-emitting layer 1311B, which can improve the device lifetime of the first light-emitting device 101. Furthermore, it allows the microcavity distance of the first light-emitting device 101 to be within a suitable range, achieving a stronger microcavity effect and improving the light extraction efficiency of the first light-emitting device 101.

[0377] [Third Group of Test Examples]

[0378] The following examples and comparative examples prepared light-emitting substrates containing a second light-emitting device 102 with different film thicknesses, wherein the structure of the second light-emitting device 102 is shown in Figure 14. The method for preparing the second light-emitting device 102 in the light-emitting substrate can be referred to the method for preparing the second light-emitting device 102 in the first set of experimental examples, and will not be repeated here.

[0379] The materials of the first electrode 15, first hole transport functional layer 183, second hole transport functional layer 182, third hole transport functional layer 181, light-emitting layer of first light-emitting unit 13A, fourth electron transport functional layer 194, first charge generation layer 143, second charge generation layer 144, fourth hole transport functional layer 172, fifth hole transport functional layer 171, light-emitting layer of second light-emitting unit 13B, third electron transport functional layer 191, second electron transport functional layer 192, first electron transport functional layer 193, second electrode 16, and capping layer CPL in Examples 16-22 and Comparative Examples 6-10 are all the same. In other words, the materials of each film layer of the second light-emitting device 102 are not differentiated in Examples 16-22 and Comparative Examples 6-10. Furthermore, the materials used in the aforementioned film layers are the same as those used in the film layers of the second light-emitting device 102 in the first set of test examples. Therefore, the structure and addition ratio of the material used in the second light-emitting device 102 can be referred to the structure and addition ratio of the material in the second light-emitting device 102 in the first set of test examples, and will not be repeated here.

[0380] In Examples 16 to 22, the thickness E3 of the third light-emitting layer 1312A is... The thickness E4 of the fourth luminescent layer 1312B is The thickness D12 of the first charge generation layer 143 is... The thickness D22 of the second charge generation layer 144 is... The thicknesses of some of the other film layers, excluding the third light-emitting layer 1312A, the fourth light-emitting layer 1312B, the first charge-generating layer 143, and the second charge-generating layer 144, are shown in Table 8.

[0381] Table 8

[0382] It should be noted that in Table 8, b1 represents the thickness of the third hole transport layer 1812, b2 represents the thickness of the second hole transport layer 182, b3 represents the thickness of the first hole transport layer 183, b4 represents the thickness of the fifth hole transport layer 1712, b5 represents the thickness of the fourth hole transport layer 172, and B3 represents the first distance. Furthermore, all thicknesses shown in Table 8 are in units of...

[0383] To more clearly illustrate the relationship between the dimensions of the charge generation layer 14 along the first direction X, the first thickness D, the dimensions of the second charge generation layer 144 along the first direction X, the fourth thickness D22, the second thickness B1, the third thickness B2, the first distance B3, the thickness b1 of the third hole transport functional layer 1811, the thickness b2 of the second hole transport functional layer 182, and the thickness b3 of the first hole transport functional layer 183 in the embodiments and comparative examples, Table 9 below is used to more clearly show the relationship between the film layer thicknesses set in the embodiments and comparative examples.

[0384] Table 9

[0385] It should be noted that the values ​​in Table 9 refer to the values ​​of the corresponding relational expressions. For example, the content of the cell corresponding to the third ratio in Example 16 is "5.63", which means that in Example 6, the third ratio calculated from the second thickness B1 and the first thickness D is 5.63. The meanings of the second thickness B1, the third thickness B2, the first thickness D, the first distance B3, and the fourth thickness D21 can be found in the foregoing content and will not be repeated here.

[0386] Based on the above settings, the driving voltage (V), luminous efficiency (%), and lifetime of the second light-emitting devices 102 in Examples 16 to 22 and Comparative Examples 11 to 15 were tested. The test results are shown in Table 10 below. The data for driving voltage (V), luminous efficiency (%), and lifetime in Table 10 are based on Comparative Example 11.

[0387] Table 10

[0388] Compared to Comparative Examples 11-15, Examples 16-22 (see Table 10) exhibit relatively lower driving voltages, higher luminous efficiency, and longer lifetimes. This is because in Examples 16-22, the third ratio in step 5 is within the range of 5.0-6.0, and the fourth ratio is within the range of 2.0-3.0, while in Comparative Examples 11-15, the third ratio is not within the range of 5.0-6.0, and the fourth ratio is not within the range of 2.0-3.0. Specifically, when the third ratio is within the range of 5.0-6.0 and the fourth ratio is within the range of 2.0-3.0, the recombination region of holes and electrons can be located in the third luminescent layer 1312A and the fourth luminescent layer 1312B, which can improve the device lifetime of the second light-emitting device 102; simultaneously, a stronger microcavity effect can be achieved, thereby improving the light extraction efficiency of the second light-emitting device 102.

[0389] Furthermore, the lifespan of the second light-emitting device 102 in Comparative Example 12 is relatively low. This may be because in Comparative Example 12, the ratio between the second thickness B1 and the sum of the third thickness B2 and the fourth thickness D22 is greater than 2.0. This indicates that when the ratio between the second thickness B1 and the sum of the third thickness B2 and the fourth thickness D22 is between 1.0 and 2.0, the recombination region of holes and electrons can be located in the third light-emitting layer 1312A and the fourth light-emitting layer 1312B, which can improve the device lifespan of the second light-emitting device 102.

[0390] The relatively low lifetime of the second light-emitting device 102 in Comparative Examples 14 and 15 may be because in Comparative Examples 9 and 10, the sum of the dimension b1 of the third hole transport functional layer 181 along the first direction X and the first distance B3 is greater than the sum of the dimensions b2+b3 of the first hole transport functional layer 183 and the second hole transport functional layer 182 along the first direction X. This indicates that when the sum of the dimension b1 of the third hole transport functional layer 181 along the first direction X and the first distance B3 is less than or equal to the sum of the dimensions b2+b3 of the first hole transport functional layer 183 and the second hole transport functional layer 182 along the first direction X, electrons and holes can recombine in the third light-emitting layer 1312A, thereby improving the luminous efficiency and lifetime of the second light-emitting device 102.

[0391] [Fourth Group of Test Examples]

[0392] The following examples and comparative examples prepared light-emitting substrates containing a third light-emitting device 103 with different film thicknesses, wherein the structure of the third light-emitting device 103 is shown in Figure 15. The method for preparing the third light-emitting device 103 in the light-emitting substrate can be referred to the method for preparing the third light-emitting device 103 in the first set of experimental examples, and will not be repeated here.

[0393] The materials of the first electrode 15, first hole transport functional layer 183, second hole transport functional layer 182, third hole transport functional layer 181, light-emitting layer of the first light-emitting unit 13A, fourth electron transport functional layer 194, first charge generation layer 143, second charge generation layer 144, fourth hole transport functional layer 172, fifth hole transport functional layer 171, light-emitting layer of the second light-emitting unit 13B, third electron transport functional layer 191, second electron transport functional layer 192, first electron transport functional layer 193, second electrode 16, and capping layer CPL in Examples 23-29 and Comparative Examples 11-15 are all the same. In other words, the materials of each film layer of the second light-emitting device 102 are not differentiated in Examples 23-29 and Comparative Examples 11-15. Furthermore, the materials used in the aforementioned film layers are the same as the materials used in the film layers of the third light-emitting device 103 in the first set of test examples. Therefore, the structure and addition ratio of the materials used in the third light-emitting device 103 can be referred to the structure and addition ratio of the third light-emitting device 103 in the first set of test examples, and will not be repeated here.

[0394] In Examples 13 to 17, the thickness E5 of the fifth light-emitting layer 1313A is... The thickness E2 of the sixth luminescent layer 1313B is The thickness D13 of the first charge generation layer 143 is... The thickness D23 of the second charge generation layer 144 is... The thicknesses of some of the other film layers, excluding the fifth light-emitting layer 1313A, the sixth light-emitting layer 1313B, the first charge-generating layer 143, and the second charge-generating layer 144, are shown in Table 11.

[0395] Table 11

[0396] It should be noted that in Table 11, f1 represents the thickness of the third hole transport layer 1813, f2 represents the thickness of the second hole transport layer 182, f3 represents the thickness of the first hole transport layer 183, f4 represents the thickness of the fifth hole transport layer 1713, f5 represents the thickness of the fourth hole transport layer 172, and F3 represents the first distance. Furthermore, all thicknesses shown in Table 11 are in units of...

[0397] To more clearly describe the relationship between the first thickness D of the charge generation layer 14 along the first direction X, the fourth thickness D23 of the second charge generation layer 144 along the first direction X, the second thickness F1 of the first functional unit 18 along the first direction X, and the third thickness F2 of the second functional unit 17 along the first direction X in the embodiments and comparative examples, the following table 12 more clearly shows the relationship between the film thicknesses set in the embodiments and comparative examples.

[0398] Table 12

[0399] It should be noted that the values ​​in Table 12 refer to the values ​​of the corresponding relational expressions. For example, the content of the cell corresponding to the fifth ratio in Example 23 is "7.22", which means that in Example 13, the fifth ratio calculated from the second thickness F1 and the first thickness D is 7.22. The meanings of the second thickness F1, the third thickness F2, the first thickness D, and the fourth thickness D23 can be found in the foregoing content and will not be repeated here.

[0400] Based on the above settings, the driving voltage (V), luminous efficiency (%), and lifetime of the third light-emitting device 103 in Examples 23 to 29 and Comparative Examples 16 to 20 were tested. The test results are shown in Table 13 below. The data for driving voltage (V), luminous efficiency (%), and lifetime in Table 13 are based on Comparative Example 16.

[0401] Table 13

[0402] Compared to Comparative Examples 16 to 20 (see Table 13), Examples 23 to 29 exhibit relatively lower driving voltages, higher luminous efficiency, and longer lifetimes. This is because the fifth ratio in Examples 23 to 29 is in the range of 7.0 to 8.0, and the sixth ratio is in the range of 3.0 to 4.0, while in Comparative Examples 16 to 120, the fifth ratio is not in the range of 7.0 to 8.0, and the sixth ratio is not in the range of 3.0 to 4.0. Specifically, when the fifth ratio is in the range of 7.0 to 8.0 and the sixth ratio is in the range of 3.0 to 4.0, the recombination region of holes and electrons can be located in the fifth light-emitting layer 1313A and the sixth light-emitting layer 1313B, which can improve the device lifetime of the third light-emitting device 103. Moreover, when the fifth ratio is in the range of 7.0 to 8.0 and the sixth ratio is in the range of 3.0 to 4.0, a stronger microcavity effect can be achieved, thereby improving the light extraction efficiency of the third light-emitting device 103.

[0403] Furthermore, the luminous efficiency and lifetime of the third light-emitting device 103 in Comparative Examples 19 and 20 are relatively low. This may be because in Comparative Examples 19 and 20, the second thickness F1 is smaller than the third thickness F2, and the ratio between the second thickness F1 and the sum of the third thickness F2 and the fourth thickness D23 is less than 1.0. This indicates that when the second thickness F1 is greater than the third thickness F2, the carrier transport rate between the first electrode 15 and the fifth light-emitting layer 1313A can be slowed down, allowing electrons and holes to recombine within the light-emitting layer, thereby improving the efficiency and lifetime of the light-emitting device 100. It also indicates that when the ratio between the second thickness F1 and the sum of the third thickness F2 and the fourth thickness D23 is in the range of 1.0 to 2.0, the recombination region of holes and electrons can be located in the fifth light-emitting layer 1313A and the sixth light-emitting layer 1313B, which can improve the device lifetime of the third light-emitting device 103. Furthermore, the microcavity distance of the third light-emitting device 103 can be kept within a suitable range to achieve a stronger microcavity effect, thereby improving the light extraction efficiency of the third light-emitting device 103.

[0404] As can be seen from the above embodiments and comparative examples, this disclosure utilizes the range of the first thickness D within... The configuration can avoid insufficient injection of electrons and holes, resulting in lower driving voltages for the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103; secondly, it can avoid deviations between the injection amounts of electrons and holes, while simultaneously increasing transmittance, thereby improving the luminous efficiency and lifespan of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103, and enhancing the consistency of their light extraction efficiency and lifespan.

[0405] [Fifth Group of Test Examples]

[0406] The following embodiments and comparative examples prepared light-emitting substrates 200 containing a first light-emitting device 101, a second light-emitting device 102, and a third light-emitting device 103 with different light-emitting layer thicknesses, as shown in Figure 12. The preparation methods for the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 in the light-emitting substrate can be referred to the preparation method of the display substrate 200 in the first set of experimental examples, and will not be repeated here.

[0407] In Examples 30 to 36 below, the thickness of the third hole transport functional layer 1811 in the first light-emitting device 101 of the display substrate 200 is... The thickness of the second hole transport functional layer 182 is The thickness of the first hole transport functional layer 183 is The thickness of the fifth hole transport functional layer 1711 is The thickness of the fourth hole transport functional layer 172 is The thickness of the first distance corresponding to the first light-emitting device 101 is The thickness D11 (i.e., the fifth thickness) of the first charge generation layer 143 is The thickness D21 (i.e., the fourth thickness) of the second charge generation layer 144 is In Examples 30 to 36 below, the thicknesses of the first light-emitting layer 1311A and the second light-emitting layer 1311B are shown in Table 14 below.

[0408] Table 14

[0409] It should be noted that in Table 14, E1 represents the thickness of the first light-emitting layer 1311A, and E2 represents the thickness of the second light-emitting layer 1311B. The units of thickness shown in Table 14 are all...

[0410] In Examples 30 to 36 below, the thickness of the third hole transport functional layer 1811 in the second light-emitting device 102 of the display substrate 200 is... The thickness of the second hole transport functional layer 182 is The thickness of the first hole transport functional layer 183 is The thickness of the fifth hole transport functional layer 1711 is The thickness of the fourth hole transport functional layer 172 is The thickness of the first distance corresponding to the second light-emitting device 102 is The thickness D12 (i.e., the fifth thickness) of the first charge generation layer 143 is The thickness D22 (i.e., the fourth thickness) of the second charge generation layer 144 is In Examples 30 to 36 below, the thicknesses of the third light-emitting layer 1312A and the fourth light-emitting layer 1312B are shown in Table 15 below.

[0411] Table 15

[0412] It should be noted that in Table 15, E3 represents the thickness of the third light-emitting layer 1312A, and E4 represents the thickness of the fourth light-emitting layer 1312B. The units of thickness shown in Table 15 are all...

[0413] In Examples 30 to 36 below, the thickness of the third hole transport functional layer 1811 in the third light-emitting device 103 of the display substrate 200 is... The thickness of the second hole transport functional layer 182 is The thickness of the first hole transport functional layer 183 is The thickness of the fifth hole transport functional layer 1711 is The thickness of the fourth hole transport functional layer 172 is The thickness of the first distance corresponding to the third light-emitting device 103 is The thickness D13 (i.e., the fifth thickness) of the first charge generation layer 143 is The thickness D23 (i.e., the fourth thickness) of the second charge generation layer 144 is In Examples 30 to 36 below, the thicknesses of the fifth light-emitting layer 1313A and the sixth light-emitting layer 1313B are shown in Table 16 below.

[0414] Table 16

[0415] It should be noted that in Table 16, E3 represents the thickness of the fifth light-emitting layer 1313A, and E4 represents the thickness of the sixth light-emitting layer 1313B. The units of thickness shown in Table 16 are all...

[0416] Based on the above settings, the driving voltage, luminous efficiency, and lifetime of the first light-emitting device 101, the second light-emitting device 102, and the third light-emitting device 103 in the display substrate 200 of Examples 30 to 36 were tested. The test results are shown in Table 17 below. Furthermore, in Table 17, the data results for the driving voltage, luminous efficiency, and lifetime of the first light-emitting device 101 are referenced to the first light-emitting device 101 in Example 33. The data results for the driving voltage, luminous efficiency, and lifetime of the second light-emitting device 102 are referenced to the second light-emitting device 102 in Example 33. The data results for the driving voltage, luminous efficiency, and lifetime of the third light-emitting device 103 are referenced to the third light-emitting device 103 in Example 33.

[0417] Table 17

[0418] In Examples 30 to 36, please refer to Table 17. In the first light-emitting device 101, Examples 31 to 35 have relatively higher luminous efficiency and longer lifetime compared to Examples 30 and 36. This is because the thickness E1 of the first light-emitting layer 1311A and the thickness E2 of the second light-emitting layer 1311B in Examples 31 to 35 are within 18nm to 22nm, while the thickness E1 of the first light-emitting layer 1311A and the thickness E2 of the second light-emitting layer 1311B in Examples 30 and 36 are not within 18nm to 22nm. Within the range of 8nm to 22nm, it is explained that when the thickness E1 of the first light-emitting layer 1311A and the thickness E2 of the second light-emitting layer 1311B are between 18nm and 22nm, the thicknesses of the first light-emitting layer 1311A and the second light-emitting layer 1311B can be matched with the material properties of the light-emitting layer of the first light-emitting device 101. Moreover, the microcavity length of the first light-emitting device 101 can be better matched with the wavelength λ1 of the first color light, and a microcavity effect can be formed in the first light-emitting device 101, thereby improving the luminous efficiency of the display substrate 200.

[0419] In Examples 30 to 36, please refer to Table 17. Compared with Example 30, Examples 31 to 36 of the second light-emitting device 102 have relatively higher luminous efficiency and relatively higher lifetime. This is because the thicknesses E3 and E4 of the third and fourth light-emitting layers in Examples 31 to 36 are within 30nm to 50nm, while those in Example 30 are not within 30nm to 50nm. This indicates that when the thicknesses E3 and E4 of the third and fourth light-emitting layers are within 30nm to 50nm, the thicknesses of the third light-emitting layer 1312A and the fourth light-emitting layer 1312B can be better matched with the material properties of the light-emitting layer of the second light-emitting device 100. Moreover, it can prevent the recombination region of holes and electrons in the second light-emitting device 102 from shifting away from the light-emitting layer. At the same time, it makes the microcavity length of the second light-emitting device 102 more matched with the wavelength λ2 of the second color light, forming a microcavity effect in the second light-emitting device 102, which can improve the luminous efficiency and lifetime of the second light-emitting device 102.

[0420] In the third light-emitting device, the luminous efficiency and lifetime of Examples 30 to 36 are all in a high range. This is because the thickness E5 of the fifth light-emitting layer and the thickness E6 of the sixth light-emitting layer in Examples 30 to 36 are both within 30nm to 50nm, which can make the thickness of the fifth light-emitting layer 1313A and the sixth light-emitting layer 1313B more compatible with the material properties of the light-emitting layer of the third light-emitting device 103. Moreover, it can avoid the displacement of the recombination region of holes and electrons in the third light-emitting device 103 from the light-emitting layer. At the same time, it can make the microcavity length of the third light-emitting device 103 more compatible with the wavelength λ3 of the third color light, so that a microcavity effect is formed in the third light-emitting device 103, which can improve the luminous efficiency and lifetime of the third light-emitting device 103.

[0421] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A display substrate, comprising: Substrate; An isolation structure is disposed on the substrate; and, A first light-emitting device, a second light-emitting device, and a third light-emitting device disposed on the substrate; The first light-emitting device is used to emit light of a first color; the second light-emitting device is used to emit light of a second color; the wavelength of the second color light is greater than the wavelength of the first color light; the third light-emitting device is used to emit light of a third color; the wavelength of the third color light is greater than the wavelength of the second color light. Each of the first light-emitting device, the second light-emitting device, and the third light-emitting device includes: The first electrode and the second electrode are arranged opposite to each other along a first direction; At least two light-emitting units are located between the first electrode and the second electrode, and are stacked along the first direction; and, At least one charge generating unit is located between two adjacent light-emitting units in the at least two light-emitting units; The isolation structure is used to isolate the charge generating unit; the dimension of the charge generating unit along the first direction is a first thickness, which is greater than or equal to... and less than or equal to 2. The display substrate according to claim 1, wherein, The light-emitting device has a light-emitting side and a non-light-emitting side arranged opposite to each other; the second electrode is closer to the light-emitting side of the light-emitting device relative to the first electrode; the at least two light-emitting units include a first light-emitting unit and a second light-emitting unit; the first light-emitting unit is closer to the first electrode relative to the second light-emitting unit; In the first light-emitting device, the first light-emitting unit includes a first light-emitting layer; the second light-emitting unit includes a second light-emitting layer; in the second light-emitting device, the first light-emitting unit includes a third light-emitting layer; the second light-emitting unit includes a fourth light-emitting layer; in the third light-emitting device, the first light-emitting unit includes a fifth light-emitting layer; the second light-emitting unit includes a sixth light-emitting layer. The first light-emitting unit further includes a first functional unit located between the first light-emitting layer and the first electrode, between the third light-emitting layer and the first electrode, or between the fifth light-emitting layer and the first electrode; the dimension of the first functional unit along the first direction is the second thickness; The second light-emitting unit further includes a second functional unit located between the second light-emitting layer and the charge-generating unit, between the fourth light-emitting layer and the charge-generating unit, or between the sixth light-emitting layer and the charge-generating unit; the second functional unit has a third thickness along the first direction. In the same light-emitting device, the second thickness is greater than or equal to the third thickness.

3. The display substrate according to claim 2, wherein, Of the first light-emitting layer, the third light-emitting layer, and the fifth light-emitting layer, at least two have the same dimension along the first direction; and / or, Of the second light-emitting layer, the fourth light-emitting layer, and the sixth light-emitting layer, at least two have the same dimension along the first direction.

4. The display substrate according to claim 2, wherein, The dimension of the first light-emitting layer along the first direction is smaller than the dimension of the third light-emitting layer along the first direction; the dimension of the first light-emitting layer along the first direction is smaller than the dimension of the fifth light-emitting layer along the first direction; the dimension of the third light-emitting layer along the first direction is smaller than or equal to the dimension of the fifth light-emitting layer along the first direction. The dimension of the second light-emitting layer along the first direction is smaller than the dimension of the fourth light-emitting layer along the first direction; the dimension of the second light-emitting layer along the first direction is smaller than the dimension of the sixth light-emitting layer along the first direction; the dimension of the fourth light-emitting layer along the first direction is less than or equal to the dimension of the sixth light-emitting layer along the first direction.

5. The display substrate according to any one of claims 2 to 4, wherein, The dimension of the first light-emitting layer along the first direction is equal to the dimension of the second light-emitting layer along the first direction; and / or, The dimension of the third light-emitting layer along the first direction is equal to the dimension of the fourth light-emitting layer along the first direction; and / or, The dimension of the fifth light-emitting layer along the first direction is equal to the dimension of the sixth light-emitting layer along the first direction.

6. The display substrate according to any one of claims 2 to 5, wherein, The size of the first light-emitting layer along the first direction ranges from 18 nm to 22 nm; the size of the second light-emitting layer along the first direction ranges from 18 nm to 22 nm; and / or, The third light-emitting layer has a size range of 30 nm to 50 nm along the first direction; the fourth light-emitting layer has a size range of 30 nm to 50 nm along the first direction; and / or... The fifth light-emitting layer has a size range of 30nm to 50nm along the first direction; the sixth light-emitting layer has a size range of 30nm to 50nm along the first direction.

7. The display substrate according to any one of claims 2 to 6, wherein, In the first light-emitting device, the ratio between the second thickness and the first thickness ranges from 4.0 to 5.0; the ratio between the third thickness and the first thickness ranges from 2.0 to 3.

0.

8. The display substrate according to any one of claims 2 to 7, wherein, In the second light-emitting device, the ratio between the second thickness and the first thickness ranges from 5.0 to 6.0; the ratio between the third thickness and the first thickness ranges from 2.0 to 3.

0.

9. The display substrate according to any one of claims 2 to 8, wherein, In the third light-emitting device, the ratio between the second thickness and the first thickness ranges from 7.0 to 8.0; the ratio between the third thickness and the first thickness ranges from 3.0 to 4.

0.

10. The display substrate according to any one of claims 2 to 9, wherein, The first electrode is an anode, and the first functional unit includes a multilayer hole transport functional layer; the second functional unit includes a multilayer hole transport functional layer. The first light-emitting unit further includes a fourth functional unit located between the first light-emitting layer and the charge-generating unit, between the third light-emitting layer and the charge-generating unit, or between the fifth light-emitting layer and the charge-generating unit; the fourth functional unit includes at least one electron transport functional layer; the second light-emitting unit further includes a fourth functional unit located between the first light-emitting layer and the charge-generating unit, between the third light-emitting layer and the charge-generating unit, or between the fifth light-emitting layer and the charge-generating unit; the fourth functional unit includes at least one electron transport functional layer; A third functional unit is located between the second light-emitting layer and the second electrode, between the fourth light-emitting layer and the second electrode, or between the sixth light-emitting layer and the second electrode; the third functional unit includes multiple electron transport functional layers. Wherein, at least one of the dimensions of the first light-emitting layer, the second light-emitting layer, the third light-emitting layer, the fourth light-emitting layer, the fifth light-emitting layer, and the sixth light-emitting layer along the first direction is smaller than the dimension along the first direction of one of the multiple hole transport functional layers included in the first functional unit and the second functional unit; and / or, At least one of the dimensions of the first light-emitting layer, the second light-emitting layer, the third light-emitting layer, the fourth light-emitting layer, the fifth light-emitting layer, and the sixth light-emitting layer along the first direction is smaller than the dimension of one of the multiple electron transport functional layers included in the third functional unit and the fourth functional unit along the first direction.

11. The display substrate according to claim 10, wherein, The first functional unit includes a first hole transport functional layer, a second hole transport functional layer, and a third hole transport functional layer arranged in a direction away from the first electrode; the second functional unit includes a fourth hole transport functional layer and a fifth hole transport functional layer arranged in a direction away from the charge generation unit. The third functional unit includes a first electron transport functional layer, a second electron transport functional layer, and a third electron transport functional layer arranged in a direction away from the second electrode; the fourth functional unit includes a fourth electron transport functional layer and a fifth electron transport functional layer arranged in a direction close to the charge generation unit. Wherein, in the first light-emitting device, the dimension of the first light-emitting layer along the first direction is smaller than the dimension of the third hole transport functional layer along the first direction; the dimension of the second light-emitting layer along the first direction is smaller than the dimension of the fifth hole transport functional layer along the first direction; and / or, In the second light-emitting device, the dimension of the third light-emitting layer along the first direction is smaller than the dimension of the second hole transport functional layer along the first direction; the dimension of the fourth light-emitting layer along the first direction is smaller than the dimension of the fourth hole transport functional layer along the first direction; and / or, In the third light-emitting device, the dimension of the fifth light-emitting layer along the first direction is smaller than the dimension of the fifth electron transport functional layer along the first direction; the dimension of the sixth light-emitting layer along the first direction is smaller than the dimension of the second electron transport functional layer along the first direction.

12. The display substrate according to any one of claims 2 to 11, wherein, The charge generation unit includes a first charge generation layer and a second charge generation layer stacked along the first direction. The first charge generation layer is closer to the first electrode than the second charge generation layer. The second charge generation layer has a fourth thickness along the first direction. In the first light-emitting device, the ratio between the second thickness and the sum of the third thickness and the fourth thickness ranges from 1.0 to 2.0; and / or, In the second light-emitting device, the ratio between the second thickness and the sum of the third thickness and the fourth thickness ranges from 1.0 to 2.0; and / or, In the third light-emitting device, the ratio between the second thickness and the sum of the third thickness and the fourth thickness ranges from 1.0 to 3.

0.

13. The display substrate according to any one of claims 2 to 12, wherein, In the second light-emitting device, the second thickness is greater than the sum of the third thickness and the fourth thickness; there is a first difference between the second thickness and the sum of the third thickness and the fourth thickness; the ratio between the first difference and the wavelength of the second color light ranges from 0.1 to 0.2; and / or, In the third light-emitting device, the second thickness is greater than the sum of the third thickness and the fourth thickness; there is a second difference between the second thickness and the sum of the third thickness and the fourth thickness; the ratio between the second difference and the wavelength of the third color light is in the range of 0.1 to 0.

2.

14. The display substrate according to any one of claims 2 to 13, wherein, The charge generation unit includes a first charge generation layer and a second charge generation layer stacked along the first direction. The first charge generation layer is closer to the first electrode than the second charge generation layer. The second charge generation layer has a fourth thickness along the first direction. The sum of the second thicknesses corresponding to the first light-emitting device, the second light-emitting device, and the third light-emitting device is the sixth thickness; the sum of the third thicknesses corresponding to the first light-emitting device, the second light-emitting device, and the third light-emitting device is the seventh thickness; the sum of the fourth thicknesses corresponding to the first light-emitting device, the second light-emitting device, and the third light-emitting device is the eighth thickness. The ratio between the sixth thickness and the sum of the seventh thickness and the eighth thickness is in the range of 1.0 to 2.

0.

15. The display substrate according to any one of claims 1 to 14, wherein, The charge generation unit includes a first charge generation layer and a second charge generation layer stacked along the first direction, wherein the first charge generation layer is closer to the first electrode than the second charge generation layer. The first charge-generating layer has a fifth thickness along the first direction, and the range of the fifth thickness is within... The second charge-generating layer has a fourth thickness along the first direction; the range of the fourth thickness is within...

16. The display substrate according to any one of claims 1 to 15, wherein, The charge generation unit includes a first charge generation layer and a second charge generation layer stacked along the first direction, wherein the first charge generation layer is closer to the first electrode than the second charge generation layer. The first charge-generating layer has a fifth thickness along the first direction, and the range of the fifth thickness is within... The second charge-generating layer has a fourth thickness along the first direction; the range of the fourth thickness is within...

17. The display substrate according to any one of claims 2 to 16, wherein, The ratio between the distance between the surface of the selected light-emitting layer furthest from the first electrode and the surface of the first electrode closest to the selected light-emitting layer, and the wavelength of the selected color light, is greater than or equal to (4n+1) / 8 and less than or equal to (4n+3) / 8; where n is 0 or a positive integer. Wherein, the selected light-emitting layer is any one of the first light-emitting layer, the second light-emitting layer, the third light-emitting layer, the fourth light-emitting layer, the fifth light-emitting layer, and the sixth light-emitting layer; the selected color light is the light corresponding to the selected light-emitting layer among the first color light, the second color light, and the third color light.

18. The display substrate according to any one of claims 2 to 17, wherein, The first electrode is an anode; the first functional unit includes a first hole transport functional layer, a second hole transport functional layer, and a third hole transport functional layer arranged in a direction away from the first electrode; The second functional unit includes a fourth hole transport functional layer and a fifth hole transport functional layer arranged in a direction away from the charge generation unit.

19. The display substrate according to claim 18, wherein, In the second light-emitting device, there is a first distance between the third hole transport functional layer and the charge generating unit; the sum of the dimension of the third hole transport functional layer along the first direction and the first distance is less than or equal to the sum of the dimensions of the first hole transport functional layer and the second hole transport functional layer along the first direction.

20. The display substrate according to claim 18 or 19, wherein, In the first light-emitting device, the size of the third hole transport functional layer along the first direction ranges from 5 nm to 10 nm; the size of the fifth hole transport functional layer along the first direction ranges from 5 nm to 10 nm; and / or, In the second light-emitting device, the size of the third hole transport functional layer along the first direction ranges from 40 nm to 45 nm; the size of the fifth hole transport functional layer along the first direction ranges from 15 nm to 20 nm; and / or, In the third light-emitting device, the size range of the third hole transport functional layer along the first direction is 80nm to 95nm; the size range of the fifth hole transport functional layer along the first direction is 25nm to 35nm.

21. The display substrate according to any one of claims 18 to 20, wherein, The size of the first hole transport functional layer along the first direction ranges from 5 nm to 15 nm; and / or, The second hole transport functional layer has a size ranging from 95 nm to 105 nm along the first direction; and / or, The size of the fourth hole transport functional layer along the first direction ranges from 50nm to 60nm.

22. The display substrate according to any one of claims 2 to 21, wherein, The material of the selected light-emitting layer includes a host material and a guest material; the doping ratio of the guest material in the material of the selected light-emitting layer is greater than 0 and less than or equal to 10%. Wherein, the selected light-emitting layer is any one of the first light-emitting layer, the second light-emitting layer, the third light-emitting layer, the fourth light-emitting layer, the fifth light-emitting layer, and the sixth light-emitting layer; the object materials contained in any two of the first light-emitting layer, the second light-emitting layer, the third light-emitting layer, the fourth light-emitting layer, the fifth light-emitting layer, and the sixth light-emitting layer may be the same or different.

23. The display substrate according to claim 22, wherein, The doping ratio of the guest material contained in the fifth light-emitting layer to the material of the fifth light-emitting layer is less than or equal to the doping ratio of the guest material contained in the third light-emitting layer to the material of the third light-emitting layer, and less than or equal to the doping ratio of the guest material contained in the fourth light-emitting layer to the material of the fourth light-emitting layer. The doping ratio of the guest material contained in the sixth light-emitting layer to the material of the sixth light-emitting layer is less than or equal to the doping ratio of the guest material contained in the third light-emitting layer to the material of the third light-emitting layer, and less than or equal to the doping ratio of the guest material contained in the fourth light-emitting layer to the material of the fourth light-emitting layer.

24. The display substrate according to any one of claims 1 to 23, wherein, The charge generation unit includes a first charge generation layer and a second charge generation layer stacked along the first direction, wherein the first charge generation layer is closer to the first electrode than the second charge generation layer. The material of the first charge generation layer includes a first matrix material and an N-type dopant; The material of the second charge generation layer includes a second matrix material and a P-type dopant; The ratio between the doping ratio of the N-type dopant in the material of the first charge generation layer and the doping ratio of the P-type dopant in the material of the second charge generation layer is greater than or equal to 0.01 and less than or equal to 0.

2.

25. The display substrate according to claim 24, wherein, The doping ratio of the N-type dopant in the material of the first charge generation layer is greater than or equal to 0 and less than or equal to 5%. And / or, The doping ratio of the P-type dopant in the material of the second charge generation layer is greater than or equal to 0 and less than or equal to 20%.

26. The display substrate according to any one of claims 1 to 25, wherein, The wavelength of the first color light is greater than or equal to 400nm and less than or equal to 500nm; the wavelength of the second color light is greater than or equal to 510nm and less than or equal to 540nm; and the wavelength of the third color light is greater than or equal to 600nm.

27. A display device comprising a display substrate as described in any one of claims 1 to 26; Also includes: A driver chip, which is used to drive the display substrate to perform display.

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