Light-emitting substrate and display apparatus

Abstract

A light-emitting substrate and a display apparatus. The light-emitting substrate comprises at least one light-emitting device, wherein each light-emitting device comprises a first electrode, a second electrode, a first light-emitting unit, a second light-emitting unit and a charge generation layer. The first light-emitting unit comprises a first light-emitting layer and a first blocking layer located on the side of the first light-emitting layer that is close to the first electrode, and the second light-emitting unit comprises a second light-emitting layer and a second blocking layer located on the side of the second light-emitting layer that is away from the second electrode, the material of the second blocking layer comprising a blocking host material and a blocking guest material. A light-emergent side of the light-emitting substrate is located on the side of the second electrode that is away from the first electrode, the value of the ratio of the distance between the second light-emitting layer and the second electrode to the distance between the first electrode and the second electrode ranges from 10% to 25%, and the value of the ratio of the distance between the first light-emitting layer and the first electrode to the distance between the first electrode and the second electrode ranges from 10% to 30%. Therefore, the light-emitting substrate has a higher level of light-emitting efficiency and a longer service life.

Description

Light-emitting substrate and display device Technical Field

[0001] Embodiments of the present disclosure relate to a light-emitting substrate and a display device. Background Art

[0002] In recent years, organic light emitting diodes (OLEDs), as a new type of flat-panel display, have garnered increasing attention. Due to their active illumination, high brightness, high resolution, wide viewing angle, fast response, low energy consumption, and flexibility, they have become a popular mainstream display product in the market. With the continuous development of these products, customers are demanding higher resolution and lower power consumption, necessitating the development of high-efficiency, low-voltage, and long-life OLEDs.

[0003] Laminated devices combine multiple light-emitting units of the same color through a charge-generating layer, increasing their luminous efficiency and lifespan to 1.5-2 times that of a single unit. They are widely used in display panels, automotive products, lighting, and other fields.

[0004] Summary of the Invention

[0005] The disclosed embodiments provide a light-emitting substrate and display device. By designing the distance between the second light-emitting layer and the second electrode, as well as the distance between the first light-emitting layer and the first electrode, multiple light beams can be maximized to form interference peaks when they meet, thereby enhancing the light. Furthermore, by doping the second blocking layer with a blocking guest material, while minimizing the effect of the second blocking layer's doping on the distance between the second light-emitting layer and the second electrode, the brightness and exciton utilization of the light-emitting device can be improved, while also preventing electron damage to the blocking host material of the second blocking layer and extending the life of the light-emitting device.

[0006] At least one embodiment of the present disclosure provides a light-emitting substrate, which includes at least one light-emitting device, each of which includes: a first electrode; a second electrode; a first light-emitting unit located between the first electrode and the second electrode; a second light-emitting unit located between the first light-emitting unit and the second electrode; and a charge generation layer located between the first light-emitting unit and the second light-emitting unit, the first light-emitting unit including a first light-emitting layer and a first blocking layer located on a side of the first light-emitting layer close to the first electrode, the second light-emitting unit including a second light-emitting layer and a second blocking layer located on a side of the second light-emitting layer away from the second electrode, the material of the second blocking layer including a blocking host material and a blocking guest material doped in the blocking host material, the light-emitting side of the light-emitting substrate is located on a side of the second electrode away from the first electrode, the ratio of the distance between the second light-emitting layer and the second electrode to the distance between the first electrode and the second electrode is in a range of 10%-25%, and the ratio of the distance between the first light-emitting layer and the first electrode to the distance between the first electrode and the second electrode is in a range of 10%-30%.

[0007] For example, in the light-emitting substrate provided in one embodiment of the present disclosure, the at least one light-emitting substrate includes a red light-emitting device, a green light-emitting device and a blue light-emitting device, the ratio of the distance between the second light-emitting layer and the second electrode of the red light-emitting device to the distance between the first electrode and the second electrode of the red light-emitting device is R1, the ratio of the distance between the second light-emitting layer and the second electrode of the green light-emitting device to the distance between the first electrode and the second electrode of the green light-emitting device is R2, the ratio of the distance between the second light-emitting layer and the second electrode of the blue light-emitting device to the distance between the first electrode and the second electrode of the blue light-emitting device is R3, and R1≤R2≤R3.

[0008] For example, in the light-emitting substrate provided in an embodiment of the present disclosure, the ratio R1 of the distance between the second light-emitting layer and the second electrode of the red light-emitting device to the distance between the first electrode and the second electrode of the red light-emitting device ranges from 10% to 15%.

[0009] For example, in the light-emitting substrate provided in an embodiment of the present disclosure, the ratio R2 of the distance between the second light-emitting layer and the second electrode of the green light-emitting device to the distance between the first electrode and the second electrode of the green light-emitting device ranges from 15% to 19%.

[0010] For example, in the light-emitting substrate provided in an embodiment of the present disclosure, the ratio R3 of the distance between the second light-emitting layer and the second electrode of the blue light-emitting device to the distance between the first electrode and the second electrode of the blue light-emitting device ranges from 19% to 25%.

[0011] For example, in the light-emitting substrate provided in one embodiment of the present disclosure, the material of the second light-emitting layer includes a second light-emitting main material and a second guest material doped in the second light-emitting main material, and the content of the blocking guest material in the second blocking layer is less than the content of the second guest material in the second light-emitting layer.

[0012] For example, in the light-emitting substrate provided in one embodiment of the present disclosure, the content of the blocking guest material in the second blocking layer is less than 2%, the content of the second guest material in the second light-emitting layer of the red light-emitting device is in the range of 2%-5%, the content of the second guest material in the second light-emitting layer of the green light-emitting device is in the range of 6%-10%, and the content of the second guest material in the second light-emitting layer of the blue light-emitting device is in the range of 4%-7%.

[0013] For example, in the light-emitting substrate provided in an embodiment of the present disclosure, the blocking guest material of the second blocking layer is the same as the second guest material of the second light-emitting layer.

[0014] For example, in the light-emitting substrate provided in an embodiment of the present disclosure, the first blocking layer is not doped with a blocking guest material.

[0015] For example, in the light-emitting substrate provided in one embodiment of the present disclosure, the material of the first light-emitting layer includes a first light-emitting main material and a first light-emitting guest material doped in the first light-emitting main material, the material of the first blocking layer is different from the first light-emitting main material, the material of the second light-emitting layer includes a second light-emitting main material and a second light-emitting guest material doped in the second light-emitting main material, and the blocking main material of the second blocking layer is different from the second light-emitting main material.

[0016] For example, in the light-emitting substrate provided in an embodiment of the present disclosure, the light-emitting color of the first light-emitting layer of each light-emitting device is the same as the light-emitting color of the second light-emitting layer.

[0017] For example, in the light-emitting substrate provided in one embodiment of the present disclosure, the material of the first light-emitting layer includes a first light-emitting main material and a first light-emitting guest material doped in the first light-emitting main material, the material of the second light-emitting layer includes a second light-emitting main material and a second guest material doped in the second light-emitting main material, and the first light-emitting guest material of the first light-emitting layer of each of the light-emitting devices is the same as the second light-emitting guest material of the second light-emitting layer.

[0018] For example, in the light-emitting substrate provided in an embodiment of the present disclosure, the first light-emitting unit further includes a hole injection layer, which is located between the first electrode and the first blocking layer. The material of the hole injection layer includes a p-type dopant and a hole transport material. The hole transport material includes at least one of aromatic amines, dimethylfluorene or carbazole materials, and the p-type dopant includes at least one of hexacyanohexaazatriphenylene, 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane, and 1,2,3-tris[(cyano)(4-cyano-2,3,5,6-tetrafluorophenyl)methylene]cyclopropane.

[0019] For example, in the light-emitting substrate provided in one embodiment of the present disclosure, the first light-emitting unit further includes a first hole transport layer, which is located between the hole injection layer and the first blocking layer; the second light-emitting unit further includes a second hole transport layer, which is located between the charge generation layer and the second blocking layer; the materials of the first hole transport layer and the second hole transport layer include at least one of aromatic amines, dimethylfluorene or carbazole materials having hole transport properties.

[0020] For example, in the light-emitting substrate provided in an embodiment of the present disclosure, the material of the first barrier layer and the barrier host material of the second barrier layer include at least one of aromatic amines, dimethylfluorene or carbazole materials having hole transport properties.

[0021] For example, in the light-emitting substrate provided in an embodiment of the present disclosure, the material of the first light-emitting layer includes a first light-emitting main material and a first light-emitting guest material doped in the first light-emitting main material, the material of the second light-emitting layer includes a second light-emitting main material and a second guest material doped in the second light-emitting main material, the first light-emitting guest material and the second light-emitting guest material of the blue light-emitting device include at least one of pyrene derivatives, anthracene derivatives, fluorene derivatives, perylene derivatives, styrylamine derivatives, and metal complexes, the first light-emitting guest material and the second light-emitting guest material of the green light-emitting device include at least one of coumarin dyes, quinacridone copper derivatives, polycyclic aromatic hydrocarbons, diamine anthracene derivatives, carbazole derivatives, and metal complexes, and the first light-emitting guest material and the second light-emitting guest of the red light-emitting device include at least one of DCM series materials and metal complexes.

[0022] For example, in the light-emitting substrate provided in one embodiment of the present disclosure, the first light-emitting unit further includes a first hole blocking layer and a first electron transport layer, the first hole blocking layer is located between the first light-emitting layer and the charge generating layer, and the first electron transport layer is located between the first hole blocking layer and the charge generating layer, the second light-emitting unit further includes a second hole blocking layer and a second electron transport layer, the second hole blocking layer is located between the second light-emitting layer and the second electrode, and the second electron transport layer is located between the second hole blocking layer and the second electrode, and the materials of the first hole blocking layer, the second hole blocking layer, the first electron transport layer and the second electron transport layer include at least one of aromatic heterocyclic compounds.

[0023] For example, in a light-emitting substrate provided in an embodiment of the present disclosure, the charge generation layer includes a p-type charge generation layer and an n-type charge generation layer that are stacked, the p-type charge generation layer is located between the n-type charge generation layer and the second light-emitting unit, the material of the p-type charge generation layer includes at least one of aromatic amines, dimethylfluorene or carbazole materials, and the material of the n-type charge generation layer includes an aromatic heterocyclic compound.

[0024] For example, in the light-emitting substrate provided in an embodiment of the present disclosure, the second light-emitting unit further includes a third blocking layer, the third blocking layer is located between the second blocking layer and the charge generation layer, and the third blocking layer is not doped with a blocking guest material.

[0025] At least one embodiment of the present disclosure provides a display device comprising any of the above-mentioned light-emitting substrates. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings in the following description only relate to some embodiments of the present disclosure, rather than limiting the present disclosure.

[0027] FIG1 is a schematic structural diagram of a light-emitting substrate provided by an embodiment of the present disclosure;

[0028] FIG2 is a schematic structural diagram of another light-emitting substrate provided by an embodiment of the present disclosure;

[0029] FIG3 is a schematic structural diagram of a light-emitting substrate;

[0030] FIG4 is a schematic structural diagram of another light-emitting substrate provided by an embodiment of the present disclosure;

[0031] FIG5 is a schematic structural diagram of another light-emitting substrate provided by an embodiment of the present disclosure;

[0032] FIG6 is a schematic diagram of a light-emitting spectrum of a light-emitting substrate provided in one embodiment of the present disclosure;

[0033] FIG7 is a schematic structural diagram of another light-emitting substrate provided in one embodiment of the present disclosure; and

[0034] FIG8 is a schematic diagram of a display device provided according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0035] To make the purpose, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0036] Unless otherwise defined, the technical or scientific terms used in this disclosure should have the usual meanings understood by persons of ordinary skill in the field to which this disclosure belongs. The words "first", "second" and similar terms used in this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" mean that the elements or objects preceding the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0037] Unless otherwise defined, the features such as "parallel", "perpendicular" and "same" used in the embodiments of the present disclosure include the cases of "parallel", "perpendicular", "same" in a strict sense, as well as the cases of "approximately parallel", "approximately perpendicular", "approximately the same" and the like which contain certain errors. For example, the above-mentioned "approximately" may mean that the difference between the compared objects is 10% of the average value of the compared objects, or within 5%. When the number of a component or element is not specifically indicated below in the embodiments of the present disclosure, it means that the component or element may be one or more, or may be understood as at least one. "At least one" refers to one or more, and "multiple" refers to at least two. The "same-layer arrangement" in the embodiments of the present disclosure refers to the relationship between multiple film layers formed by the same material after the same step (for example, a one-step patterning process). The "same layer" here does not always mean that the thickness of multiple film layers is the same or the height of multiple film layers in the cross-sectional view is the same.

[0038] Currently, the carrier recombination areas in multiple light-emitting units in the same color pixel in a stacked device are all at the interface between their respective light-emitting layers and barrier layers (also called prime layers). The concentration of excitons formed at the interface is also the highest, and then they diffuse into the light-emitting layer to transfer energy. Due to the accumulation of high concentrations of excitons and carriers at this interface, some of the excitons will be quenched, resulting in a loss of some light efficiency. At the same time, in OLED devices, the material most susceptible to deterioration is the material of the barrier layer. This is because the material of the barrier layer is generally an electron-rich system material, generally containing an aniline structure. Excessive electrons will produce a repulsive force with the rich electrons in the barrier layer material. This repulsive force will cause the δ bond of the benzene ring on the aniline to distort. The result of the δ bond distortion caused by external force is the breakage of the bond. The defects caused by the breakage of the bond are the degradation of the barrier layer material and the attenuation of the life of the light-emitting device.

[0039] The present disclosure provides a light-emitting substrate comprising at least one light-emitting device, each of which comprises a first electrode, a second electrode, a first light-emitting unit, a second light-emitting unit, and a charge generation layer. The first light-emitting unit is located between the first electrode and the second electrode, the second light-emitting unit is located between the first light-emitting unit and the second electrode, and the charge generation layer is located between the first light-emitting unit and the second light-emitting unit. The first light-emitting unit comprises a first light-emitting layer and a first blocking layer located on the side of the first light-emitting layer closer to the first electrode, the second light-emitting unit comprises a second light-emitting layer and a second blocking layer located on the side of the second light-emitting layer farther from the second electrode, the material of the second blocking layer comprising a blocking host material and a blocking guest material doped in the blocking host material. The light-emitting side of the light-emitting substrate is located on the side of the second electrode farther from the first electrode, the ratio of the distance between the second light-emitting layer and the second electrode to the distance between the first electrode and the second electrode is in the range of 10%-25%, and the ratio of the distance between the first light-emitting layer and the first electrode to the distance between the first electrode and the second electrode is in the range of 10%-30%.

[0040] In the light-emitting substrate provided in the embodiment of the present disclosure, the light-emitting side of the light-emitting substrate is located on the side of the second electrode away from the first electrode. After multiple beams of light, such as light emitted by the second light-emitting layer, light emitted by the first light-emitting layer, and light emitted by the first light-emitting layer reflected by the first electrode, meet, light interference will occur. By setting the ratio of the distance between the second light-emitting layer and the second electrode to the distance between the first electrode and the second electrode to be in the range of 10%-25%, and the ratio of the distance between the first light-emitting layer and the first electrode to the distance between the first electrode and the second electrode to be in the range of 10%-30%, at this time, the peaks of the multiple beams of light can be superimposed as much as possible to form interference peaks, which can play a reinforcing role, effectively ensure the interference effect of the multiple beams of light between the first electrode and the second electrode, improve the luminous brightness of the light-emitting device, and improve the luminous efficiency of the light-emitting device.

[0041] In the light-emitting substrate provided in the embodiments of the present disclosure, the second blocking layer is located on the side of the second light-emitting layer away from the second electrode. The second blocking layer is selectively doped with a blocking guest material. While achieving the aforementioned improvements in luminous efficiency and the lifespan of the light-emitting device, this does not affect the distance between the second light-emitting layer and the second electrode. This design facilitates the sizing, manufacturing, and mass production of the light-emitting device, and ensures consistent luminous performance of the light-emitting device. For example, when the blocking guest material doped in the second blocking layer interacts with excitons to emit light, the second blocking layer also serves as a light-emitting layer or a weakly light-emitting layer. Since the second blocking layer is located on the side of the second light-emitting layer away from the second electrode, the doping of the second blocking layer does not affect the distance between the second light-emitting layer and the second electrode.

[0042] In the light-emitting substrate provided in the embodiments of the present disclosure, the selection of doping a blocking guest material in the second blocking layer can also simultaneously bring about the following effects: on the one hand, the doped blocking guest material can react with the excitons at the interface between the second light-emitting layer and the second blocking layer, reducing the loss of luminous brightness and the reduction of luminous efficiency caused by quenching, thereby improving the luminous efficiency. For example, when the doped blocking guest material interacts with the excitons to emit light, it can also improve the brightness of the light-emitting device and the exciton utilization rate, while not affecting the light color of the light-emitting device. In this case, the second blocking layer can also be called a weak light-emitting layer. On the other hand, the doped blocking guest material can also prevent electrons from damaging the blocking host material of the second blocking layer, thereby improving the life of the second blocking layer and, in turn, improving the service life of the light-emitting device.

[0043] The light-emitting substrate and the display device provided by the embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0044] An embodiment of the present disclosure provides a light-emitting substrate. FIG1 is a schematic structural diagram of a light-emitting substrate provided in one embodiment of the present disclosure. As shown in FIG1 , the light-emitting substrate 100 includes at least one light-emitting device 110. Each light-emitting device 110 includes a first electrode 111, a second electrode 115, a first light-emitting unit 112, a second light-emitting unit 114, and a charge generation layer 113. The first light-emitting unit 112 is located between the first electrode 111 and the second electrode 115. The second light-emitting unit 114 is located between the first light-emitting unit 112 and the second electrode 115. The charge generation layer 113 is located between the first light-emitting unit 112 and the second light-emitting unit 114. The first light-emitting unit 112 includes a first light-emitting layer 1124 and a first blocking layer 1123 located on a side of the first light-emitting layer 1124 close to the first electrode 111. The second light-emitting unit 114 includes a second light-emitting layer 1143 and a second blocking layer 1142 located on a side of the second light-emitting layer 1143 away from the second electrode 115. The material of the second blocking layer 1142 includes a blocking host material and a blocking guest material doped in the blocking host material. The light-emitting side S1 of the light-emitting substrate 100 is located on the side of the second electrode 115 away from the first electrode 111. The ratio of the distance D2 between the second light-emitting layer 1143 and the second electrode 115 to the distance D0 between the first electrode 111 and the second electrode 115 is in a range of 10% to 25%. The ratio of the distance D1 between the first light-emitting layer 1124 and the first electrode 111 to the distance D0 between the first electrode 111 and the second electrode 115 is in a range of 10% to 30%. For example, the light-emitting mode of this light-emitting substrate can also be called top emission.

[0045] It should be noted that the distance between two elements in the present disclosure refers to the distance between their facing surfaces, not the distance between their centers. For example, as shown in FIG1 , the distance D2 between the second light-emitting layer 1143 and the second electrode 115 is the vertical distance between the surface of the second light-emitting layer 1143 near the second electrode 115 and the surface of the second electrode 115 near the second light-emitting layer 1143. For example, the distance D0 between the first electrode 111 and the second electrode 115 is the vertical distance between the surface of the first electrode 111 near the second electrode 115 and the surface of the second electrode 115 near the first electrode 111. For example, the distance D1 between the first light-emitting layer 1124 and the first electrode 111 is the vertical distance between the surface of the first light-emitting layer 1124 near the first electrode 111 and the surface of the first electrode 111 near the first light-emitting layer 1124.

[0046] In the light-emitting substrate 100 provided in the embodiment of the present disclosure, the light-emitting side S1 of the light-emitting substrate 100 is located on the side of the second electrode 115 away from the first electrode 111. When multiple beams of light, such as the light emitted by the second light-emitting layer 1143, the light emitted by the first light-emitting layer 1124, and the light emitted by the first light-emitting layer 1124 reflected by the first electrode 111, meet, light interference occurs. By setting the distance D2 between the second light-emitting layer 1143 and the second electrode 115 to be equal to the distance D0 between the first electrode 111 and the second electrode 115, the light interference phenomenon occurs. The ratio ranges from 10% to 25%, and the ratio of the distance D1 between the first light-emitting layer 1124 and the first electrode 111 to the distance D0 between the first electrode 111 and the second electrode 115 ranges from 10% to 30%. At this time, the peaks of the multiple beams of light can be superimposed as much as possible to form interference peaks, which can play a reinforcing role, effectively ensure the interference effect of the multiple beams of light between the first electrode 111 and the second electrode 115, improve the luminous brightness of the light-emitting device 110, and improve the luminous efficiency of the light-emitting device.

[0047] In the light-emitting substrate 100 provided in the embodiment of the present disclosure, the second blocking layer 1142 is located on the side of the second light-emitting layer 1143 away from the second electrode 115. The second blocking layer 1142 is selectively doped with a blocking guest material. While achieving the aforementioned improvements in luminous efficiency and the lifespan of the light-emitting device, this does not affect the distance D1 between the second light-emitting layer 1143 and the second electrode 115. This design facilitates the sizing, manufacturing, and mass production of the light-emitting device 110, and ensures consistent luminous performance across the light-emitting device 110. For example, when the blocking guest material doped in the second blocking layer 1142 interacts with excitons to produce light, the second blocking layer 1142 also serves as a light-emitting layer or a weakly light-emitting layer. Because the second blocking layer 1142 is located on the side of the second light-emitting layer 1143 away from the second electrode 115, the doping of the second blocking layer 1142 does not affect the distance D2 between the second light-emitting layer 1143 and the second electrode 115.

[0048] In the light-emitting substrate 100 provided in the embodiment of the present disclosure, the selection of doping a blocking guest material in the second blocking layer 1142 can also simultaneously bring about the following effects: on the one hand, the doped blocking guest material can react with the excitons at the interface between the second light-emitting layer 1143 and the second blocking layer 1142, reducing the loss of luminous brightness and the reduction of luminous efficiency caused by quenching, thereby improving the luminous efficiency. For example, when the doped blocking guest material interacts with the excitons to emit light, it can also improve the brightness of the light-emitting device 110 and the exciton utilization rate, while not affecting the light color of the light-emitting device 110. In this case, the second blocking layer 1142 can also be called a weak light-emitting layer. On the other hand, the doped blocking guest material can also prevent electrons from damaging the blocking host material of the second blocking layer 1142, thereby improving the life of the second blocking layer 1142 and, in turn, improving the service life of the light-emitting device 110.

[0049] For example, the ratio of the distance D2 between the second light-emitting layer 1143 and the second electrode 115 to the distance D0 between the first electrode 111 and the second electrode 115 can be 12.3%, 15%, 15.6%, 19%, or 19.4%. For example, the ratio of the distance D1 between the first light-emitting layer 1124 and the first electrode 111 to the distance D0 between the first electrode 111 and the second electrode 115 can be 21.2%, 18.9%, or 18.6%. Of course, the embodiments of the present disclosure are not limited to this, and the two ratios can be any value within the corresponding value ranges.

[0050] In some examples, as shown in FIG1 , at least one light-emitting substrate 100 includes a red light-emitting device 110R, a green light-emitting device 110G, and a blue light-emitting device 110B. A ratio of a distance D2 between the second light-emitting layer 1143 and the second electrode 115 of the red light-emitting device 110R to a distance D0 between the first electrode 111 and the second electrode 115 of the red light-emitting device 110 is R1, a ratio of a distance D2 between the second light-emitting layer 1143 and the second electrode 115 of the green light-emitting device 110G to a distance D0 between the first electrode 111 and the second electrode 115 of the green light-emitting device 110 is R2, and a ratio of a distance D2 between the second light-emitting layer 1143 and the second electrode 115 of the blue light-emitting device 110 to a distance D0 between the first electrode 111 and the second electrode 115 of the blue light-emitting device 110 is R3, where R1≤R2≤R3. Light of different colors has different wavelengths. By making R1≤R2≤R3, the luminous brightness of the red light-emitting device 110, the green light-emitting device 110, and the blue light-emitting device 110 in the light-emitting substrate 100 can be improved.

[0051] It should be noted that, to more clearly illustrate the red light-emitting device 110R, the green light-emitting device 110G, and the blue light-emitting device 110B, FIG1 only labels the layers and distances of the red light-emitting device 110R. The layers and distances of the green light-emitting device 110G and the blue light-emitting device 110B refer to the red light-emitting device 110R. For example, among the layers of the red light-emitting device 110R, the green light-emitting device 110G, and the blue light-emitting device 110B, except for the light-emitting layers of each color, other layers such as the first electrode, the second electrode, the charge generation layer, the first blocking layer, and the hole transport layer, hole blocking layer, electron transport layer, and electron injection layer mentioned below can be formed from the same material layer through the same patterning process.

[0052] In some examples, as shown in FIG1 , the ratio R1 of the distance D2 between the second light-emitting layer 1143 and the second electrode 115 of the red light-emitting device 110 to the distance D0 between the first electrode 111 and the second electrode 115 of the red light-emitting device 110 is in the range of 10%-15%. This ensures that the multiple beams of light emitted or reflected by the first light-emitting layer 1124 and the second light-emitting layer 1143 of the red light-emitting device 110 form interference peaks when they meet, thereby improving the brightness of the red light-emitting device 110. For example, the ratio of the distance D2 between the second light-emitting layer 1143 and the second electrode 115 of the red light-emitting device 110 to the distance D0 between the first electrode 111 and the second electrode 115 of the red light-emitting device 110 can be 12.3%. Of course, the present disclosure is not limited to this, and the ratio can be any value within the corresponding range.

[0053] For example, the ratio of the distance D1 between the first light-emitting layer 1124 and the first electrode 111 of the red light-emitting device 110 to the distance D0 between the first electrode 111 and the second electrode 115 of the red light-emitting device 110 can be 21.2%. Of course, the embodiments of the present disclosure are not limited to this, and the ratio can be any value within the corresponding value range.

[0054] In some examples, as shown in FIG1 , the ratio R2 of the distance D2 between the second light-emitting layer 1143 and the second electrode 115 of the green light-emitting device 110 to the distance D0 between the first electrode 111 and the second electrode 115 of the green light-emitting device 110 is in the range of 15% to 19%. In this case, it can be better ensured that the multiple beams of light emitted or reflected by the first light-emitting layer 1124 and the second light-emitting layer 1143 of the green light-emitting device 110 form interference peaks when they meet, thereby further improving the luminous brightness of the green light-emitting device 110. For example, the ratio of the distance D2 between the second light-emitting layer 1143 and the second electrode 115 of the green light-emitting device 110 to the distance D0 between the first electrode 111 and the second electrode 115 of the green light-emitting device 110 can be 15.6%. Of course, the embodiments of the present disclosure are not limited to this, and the ratio can be any value within the corresponding value range.

[0055] For example, the ratio of the distance D1 between the first light-emitting layer 1124 and the first electrode 111 of the green light-emitting device 110 to the distance D0 between the first electrode 111 and the second electrode 115 of the green light-emitting device 110 can be 18.9%. Of course, the embodiment of the present disclosure is not limited to this, and the ratio can be any value within the corresponding value range.

[0056] In some examples, as shown in FIG1 , the ratio R3 of the distance D2 between the second light-emitting layer 1143 and the second electrode 115 of the blue light-emitting device 110 to the distance D0 between the first electrode 111 and the second electrode 115 of the blue light-emitting device 110 is in the range of 19% to 25%. This ensures that the multiple beams of light emitted or reflected by the first light-emitting layer 1124 and the second light-emitting layer 1143 of the blue light-emitting device 110 form interference peaks when they meet, thereby improving the brightness of the blue light-emitting device 110. For example, the ratio of the distance D2 between the second light-emitting layer 1143 and the second electrode 115 of the blue light-emitting device 110 to the distance D0 between the first electrode 111 and the second electrode 115 of the blue light-emitting device 110 can be 19.4%. Of course, the present disclosure is not limited to this, and the ratio can be any value within the corresponding range.

[0057] For example, the ratio of the distance D1 between the first light-emitting layer 1124 and the first electrode 111 of the blue light-emitting device 110 to the distance D0 between the first electrode 111 and the second electrode 115 of the blue light-emitting device 110 can be 18.6%. Of course, the embodiment of the present disclosure is not limited to this, and the ratio can be any value within the corresponding value range.

[0058] In some examples, the material of the second light-emitting layer 1143 includes a second light-emitting host material and a second guest material doped in the second light-emitting host material, and the content of the blocking guest material in the second blocking layer 1142 is less than the content of the second guest material in the second light-emitting layer 1143. Because the lowest triplet state (T1) of the material in the second blocking layer 1142 is higher, the number of excitons that diffuse into the second blocking layer 1142 is smaller. Therefore, by making the content of the blocking guest material in the second blocking layer 1142 less than the content of the second guest material in the second light-emitting layer 1143, carrier quenching is reduced and energy transfer to the interior of the second light-emitting layer 1143 is also facilitated.

[0059] For example, the content of the blocking guest material in the second blocking layer 1142 is less than 2%. For example, the content of the blocking guest material in the second blocking layer 1142 is less than 1%.

[0060] In this specification, “content” refers to mass percentage. For example, the content of the blocking guest material in the second blocking layer 1142 refers to the percentage of the mass of the blocking guest material in the second blocking layer 1142 to the total mass of the second blocking layer 1142 .

[0061] For example, the content of the second guest material in the second light-emitting layer 1143 of the red light-emitting device 110 is in the range of 2%-5%, the content of the second guest material in the second light-emitting layer 1143 of the green light-emitting device 110 is in the range of 6%-10%, and the content of the second guest material in the second light-emitting layer 1143 of the blue light-emitting device 110 is in the range of 4%-7%. The present disclosure does not specifically limit the content of the second guest material in the second light-emitting layer 1143 of the light-emitting device 110.

[0062] In some examples, the blocking guest material of the second blocking layer 1142 is the same as the second guest material of the second light-emitting layer 1143. Thus, the color of light emitted by the blocking guest material of the second blocking layer 1142 interacting with excitons is the same as the color of light emitted by the second light-emitting layer 1143, making the color of light emitted by the second light-emitting unit 114 purer.

[0063] For example, the blocking guest material of the second blocking layer 1142 can be different from the second guest material of the second light-emitting layer 1143. For example, when the light-emitting device 110 is a blue light-emitting device 110, the blocking guest material of the second blocking layer 1142 can be a material that emits a darker blue light than the second guest material of the second light-emitting layer 1143, and the second guest material of the second light-emitting layer 1143 can be a material that emits a lighter blue light than the blocking guest material of the second blocking layer 1142. This can improve the service life of the light-emitting device 110. For example, when the light-emitting device 110 is a red light-emitting device 110 or a green light-emitting device, the same process is employed and will not be further described herein.

[0064] In some examples, as shown in FIG1 , the first barrier layer 1123 is not doped with a blocking guest material. For example, when the first barrier layer 1123 is not doped with a blocking guest material, the distance D1 between the first light-emitting layer 1124 and the first electrode 111 is constant, which can facilitate the size design of the light-emitting device 110 so that the multiple beams of light between the first electrode 111 and the second electrode 115 form an interference peak as much as possible when they meet, thereby achieving better luminance of the light-emitting device 110.

[0065] For example, the first blocking layer 1123 may also include a blocking host material and a blocking guest material doped within the blocking host material. In this example, when the first blocking layer 1123 is doped with the blocking guest material, for example, if the blocking guest material is the same as the first luminescent guest material of the first luminescent layer 1124, the first blocking layer 1123 will emit weak light. In this case, by ensuring that the ratio of the distance between the first blocking layer 1123 and the first electrode 111 to the distance between the first electrode 111 and the second electrode 115 is within a range of 10%-30%, the peaks of the multiple beams emitted by the first luminescent layer, the first blocking layer, and the second luminescent layer can overlap to form interference peaks. This effectively ensures the interference effect of the multiple beams between the first electrode and the second electrode, thereby improving the brightness and luminous efficiency of the light-emitting device. Furthermore, the doped blocking guest material can react with excitons at the interface between the first luminescent layer 1124 and the first blocking layer 1123, reducing the loss of brightness and the reduction in luminous efficiency caused by quenching. For example, when the doped blocking guest material interacts with excitons to emit light, it can also improve the brightness of the light-emitting device 110 and the exciton utilization rate without affecting the light color of the light-emitting device 110; on the other hand, the doped blocking guest material can also avoid the destruction of the blocking host material of the first blocking layer 1123 by electrons, which can increase the life of the first blocking layer 1123, and thus increase the service life of the light-emitting device 110.

[0066] In some examples, the material of the first light-emitting layer 1124 includes a first light-emitting host material and a first light-emitting guest material doped in the first light-emitting host material, the material of the first blocking layer 1123 is different from the first light-emitting host material, the material of the second light-emitting layer 1143 includes a second light-emitting host material and a second light-emitting guest material doped in the second light-emitting host material, and the blocking host material of the second blocking layer 1142 is different from the second light-emitting host material.

[0067] In some examples, the color emitted by the first light-emitting layer 1124 of each light-emitting device 110 is the same as the color emitted by the second light-emitting layer 1143. This improves the luminous efficiency and lifetime of the light-emitting device 110. For example, the same luminous color may mean that the wavelength of light emitted by the first light-emitting layer 1124 is the same as the wavelength of light emitted by the second light-emitting layer 1143, or that the difference between the wavelengths of light emitted by the first light-emitting layer 1124 and the second light-emitting layer 1143 is within a range of ±10%.

[0068] In some examples, the first luminescent guest material of the first luminescent layer 1124 of each light-emitting device 110 is the same as the second luminescent guest material of the second luminescent layer 1143. This can improve the luminous efficiency and lifetime of the light-emitting device 110 and make the light emitted by the light-emitting device 110 purer.

[0069] In some examples, as shown in the figure, the first light emitting unit 112 further includes a hole injection layer 1121, which is located between the first electrode 111 and the first blocking layer 1123. The material of the hole injection layer 1121 includes a p-type dopant and a hole transport material.

[0070] For example, the hole transport material includes at least one of aromatic amines, dimethylfluorene, or carbazole materials. For example, the hole transport material having hole transport properties may be 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (TPD), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (BAFLP), 4,4'-bis[N-(9,9-dimethylfluoren-2-yl)-N-phenylamino]biphenyl (DFLDPBi), 4,4'-bis(9-carbazolyl)biphenyl (CBP), 9-phenyl-3-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (PCzPA), etc.

[0071] For example, the p-type dopant may be a p-type dopant of a strong electron-withdrawing system. For example, the p-type dopant of a strong electron-withdrawing system includes at least one of hexacyanohexaazatriphenylene, 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ), and 1,2,3-tris[(cyano)(4-cyano-2,3,5,6-tetrafluorophenyl)methylene]cyclopropane.

[0072] In some examples, as shown in FIG1 , the first light-emitting unit 112 further includes a first hole transport layer 1122, which is located between the hole injection layer 1121 and the first blocking layer 1123. The second light-emitting unit 114 further includes a second hole transport layer 1141, which is located between the charge generation layer 113 and the second blocking layer 1142. The materials of the first hole transport layer 1122 and the second hole transport layer 1141 include at least one of aromatic amines, dimethylfluorene, or carbazole materials having hole transport properties. The specific materials are described above and are not repeated here.

[0073] In some examples, as shown in FIG1 , the material of the first blocking layer 1123 and the blocking main material of the second blocking layer 1142 are at least one of aromatic amines, dimethylfluorene or carbazole materials having hole transport properties. Specific materials are described above and will not be repeated here.

[0074] In some examples, the material of the first light-emitting layer 1124 includes a first light-emitting host material and a first light-emitting guest material doped in the first light-emitting host material, and the material of the second light-emitting layer 1143 includes a second light-emitting host material and a second guest material doped in the second light-emitting host material. For example, the first light-emitting host material and the second light-emitting host material can include a single material or two or more materials, which is not limited in the present disclosure.

[0075] For example, the first and second light-emitting guest materials of the blue light-emitting device 110 include at least one of pyrene derivatives, anthracene derivatives, fluorene derivatives, perylene derivatives, styrylamine derivatives, and metal complexes.

[0076] For example, the first light-emitting guest material and the second light-emitting guest material of the blue light-emitting device 110 include N1,N6-di([1,1'-biphenyl]-2-yl)-N1,N6-di([1,1'-biphenyl]-4-yl)pyrene-1,6-diamine, 9,10-di-(2-naphthyl)anthracene (ADN), 2-methyl-9,10-di-2-naphthylanthracene (MADN), 2,5,8,11-tetra-tert-butylperylene (TBPe), 4,4'-bis[4-(diphenylamino)phenylvinyl]biphenyl (BDAVBi), 4,4'-bis[4-(di-p-tolylamino)phenylvinyl]biphenyl (DPAVBi), and bis(4,6-difluorophenylpyridine-C2,N)picolinyliridium (FIrpic).

[0077] For example, the first luminescent guest material and the second luminescent guest material of the green light-emitting device 110 include at least one of coumarin dyes, quinacridone copper derivatives, polycyclic aromatic hydrocarbons, diamine anthracene derivatives, carbazole derivatives, and metal complexes.

[0078] For example, the first light-emitting guest material and the second light-emitting guest material of the green light-emitting device 110 include coumarin 6 (C-6), coumarin 545T (C-525T), quinacridone copper (QA), N,N'-dimethylquinacridone (DMQA), 5,12-diphenylnaphthonaphthalene (DPT), N10,N10'-diphenyl-N10,N10'-diphthaloyl-9,9'-dianthracene-10,10'-diamine (abbreviated as: BA-NPB), tris(8-hydroxyquinoline)aluminum(III) (abbreviated as: Alq3), tris(2-phenylpyridine)iridium (Ir(ppy)3), and di(2-phenylpyridine)iridium acetylacetonate (Ir(ppy)2(acac)).

[0079] For example, the first luminescent guest material and the second luminescent guest of the red light-emitting device 110 include at least one of a DCM series material and a metal complex.

[0080] For example, the first light-emitting guest material and the second light-emitting guest of the red light-emitting device 110 include 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminophenylvinyl)-4H-pyran (DCM), 4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulolidine-9-enyl)-4H-pyran (DCJTB), bis(1-phenylisoquinoline)(acetylacetonate)iridium(III) (Ir(piq)2(acac)), octaethylporphyrin platinum (abbreviated as: PtOEP), bis(2-(2'-benzothienyl)pyridine-N,C3')(acetylacetonate)iridium complex (abbreviated as: Ir(btp)2(acac)), etc.

[0081] In some examples, as shown in FIG1 , the first light-emitting unit 112 further includes a first hole blocking layer 1125 and a first electron transport layer 1126 , wherein the first hole blocking layer 1125 is located between the first light-emitting layer 1124 and the charge generation layer 113 , and the first electron transport layer 1126 is located between the first hole blocking layer 1125 and the charge generation layer 113 .

[0082] In some examples, as shown in Figure 1, the second light-emitting unit 114 also includes a second hole blocking layer 1144 and a second electron transport layer 1145, the second hole blocking layer 1144 is located between the second light-emitting layer 1143 and the second electrode 115, and the second electron transport layer 1145 is located between the second hole blocking layer 1144 and the second electrode 115.

[0083] For example, the materials of the first hole blocking layer 1125, the second hole blocking layer 1144, the first electron transport layer 1126, and the second electron transport layer 1145 include aromatic heterocyclic compounds. For example, the materials of the first hole blocking layer 1125, the second hole blocking layer 1144, the first electron transport layer 1126, and the second electron transport layer 1145 include imidazole derivatives such as imidazole derivatives, imidazopyridine derivatives, and benzimidazolephenanthridine derivatives; oxazine derivatives such as pyrimidine derivatives and triazine derivatives; and compounds containing a nitrogen-containing six-membered ring structure such as quinoline derivatives, isoquinoline derivatives, and phenanthroline derivatives (including compounds having a phosphine oxide-based substituent on the heterocyclic ring). 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (OXD-7), 3-(4-tert-butylphenyl)-4-phenyl-5-(4-biphenyl)-1,2,4-triazole (TAZ), 3-(4-tert-butylphenyl)-4-(4-ethylphenyl)-5-(4-biphenyl)-1,2,4-triazole (p-EtTAZ), bathophenanthroline (BPhen), (BCP), 4,4'-bis(5-methylbenzoxazol-2-yl)stilbene (BzOs), etc.

[0084] In some examples, as shown in the figure, the charge generation layer 113 includes a p-type charge generation layer 1131 and an n-type charge generation layer 1132 stacked together, and the p-type charge generation layer 1131 is located between the n-type charge generation layer 1132 and the second light emitting unit 114 .

[0085] For example, the material of the p-type charge generation layer 1131 includes at least one of aromatic amines, dimethylfluorene, or carbazole materials. The specific materials are described above and will not be repeated here.

[0086] For example, the material of the n-type charge generation layer 1132 includes an aromatic heterocyclic compound. The specific materials are described above and will not be repeated here.

[0087] In some examples, the light-emitting substrate 100 may further include an electron injection layer, which is located between the second electron transport layer 1145 and the second electrode 115. For example, the material of the electron injection layer includes an alkali metal or a metal. For example, the material of the electron injection layer includes lithium fluoride (LiF), ytterbium (Yb), magnesium (Mg), calcium (Ca), or a compound of LiF, Yb, Mg, and Ca.

[0088] In some examples, the light emitting substrate 100 may further include a light extraction layer located on a side of the second electrode 115 away from the first electrode 111 .

[0089] For example, the material of the p-type dopant of the hole injection layer 1121 may be F4TCNQ, which has the following structure:

[0090] For example, the materials of the first hole transport layer 1122, the second hole transport layer 1141, and the p-type charge generation layer 1131 may be m-MTDATA, and its structure is as follows:

[0091] For example, the material of the first blocking layer 1123, the second blocking layer 1142, and the light extraction layer can be NPB, and the structure thereof is as follows:

[0092] For example, the material of the first hole blocking layer 1125 and the second hole blocking layer 1144 may be TPBi, and the structure thereof is as follows:

[0093] For example, the materials of the first electron transport layer 1126, the second electron transport layer 1145, and the n-type charge generation layer 1132 may be BCP, and the structure thereof is as follows:

[0094] For example, the first light-emitting host material of the first light-emitting layer 1124 of the blue light-emitting device 110 and the second light-emitting host material of the second light-emitting layer 1143 of the blue light-emitting device 110 may be the following structures:

[0095] For example, the first light-emitting guest material of the first light-emitting layer 1124 of the blue light-emitting device 110 and the first light-emitting guest material of the second light-emitting layer 1143 of the blue light-emitting device 110 may be the following structures:

[0096] For example, the first light-emitting host material of the first light-emitting layer 1124 of the green light-emitting device 110 and the red light-emitting device 110 and the second light-emitting host material of the second light-emitting layer 1143 of the green light-emitting device 110 and the red light-emitting device 110 may be CBP, and its structure is as follows:

[0097] For example, the first luminescent guest material of the first luminescent layer 1124 of the green light-emitting device 110 and the first luminescent guest material of the second luminescent layer 1143 of the green light-emitting device 110 may be Ir(ppy)3, and the structure thereof is as follows:

[0098] For example, the first luminescent guest material of the first luminescent layer 1124 of the red light-emitting device 110 and the first luminescent guest material of the second luminescent layer 1143 of the red light-emitting device 110 may be Ir(piq)(acac), and the structure thereof is as follows:

[0099] FIG2 is a schematic diagram of the structure of another light-emitting substrate provided in one embodiment of the present disclosure. As shown in FIG2 , this light-emitting substrate 100 differs from the light-emitting substrate 100 shown in FIG1 in that the second light-emitting unit 114 of this light-emitting substrate 100 further includes a third blocking layer 1147, which is located between the second blocking layer 1142 and the charge generation layer 113. Third blocking layer 1147 is not doped with a blocking guest material.

[0100] The thickness of the second blocking layer 1142 of the second light-emitting unit 114 of the light-emitting device 110 of the same color shown in Figure 2 is less than the thickness of the second blocking layer 1142 of the second light-emitting unit 114 of the light-emitting device 110 of the corresponding color shown in Figure 1. Therefore, the doping amount of the blocking guest material in the second blocking layer 1142 of the light-emitting substrate 100 shown in Figure 2 is less than the doping amount of the second blocking layer 1142 of the light-emitting substrate 100 shown in Figure 1, thereby having less impact on the process.

[0101] For example, the thicknesses of the second barrier layer 1142 and the third barrier layer 1147 of the second light emitting unit 114 of the same color light emitting device 110 shown in FIG. 2 are substantially the same as the thickness of the second barrier layer 1142 of the second light emitting unit 114 of the corresponding color light emitting device 110 shown in FIG. 1 .

[0102] Fig. 3 is a schematic structural diagram of a light-emitting substrate. As shown in Fig. 3, the light-emitting substrate 1 includes a red light-emitting device 10R, a green light-emitting device 10G, and a blue light-emitting device 10B.

[0103] For example, as shown in Figure 3, the anode 11 of the blue light-emitting device 10B is indium tin oxide (ITO), and the first light-emitting unit 12 includes a hole injection layer 121, a first hole transport layer 122, a first blocking layer 123, a first light-emitting layer 124, a first hole blocking layer 125 and a first electron transport layer 126. The hole injection layer 121 is a mixture of m-MTDATA and F4TCNQ, with F4TCNQ accounting for 1%, and the thickness of the hole injection layer 121 is 10nm; the material of the first hole transport layer 122 is m-MTDATA, with a thickness of 30nm; the material of the first blocking layer 123 is NPB, with a thickness of 10nm; the first light-emitting layer 124 is a mixture of structural formula-1 and structural formula-2 mentioned above, with structural formula-2 accounting for 5%, and the thickness of the first light-emitting layer 124 is 15nm; the material of the first hole blocking layer 125 is TPBI, with a thickness of 5nm; the first electron transport layer 126 is a mixture of BCP and 8-hydroxyquinoline-lithium (Liq) in a ratio of 1:1, and the thickness of the first electron transport layer 126 is 15nm. The charge generation layer 13 includes an n-type charge generation layer 132 and a p-type charge generation layer 131. The n-type charge generation layer 132 is a mixture of BCP and Yb, with the Yb content being 0.5% and a thickness of 9 nm. The p-type charge generation layer 131 is a mixture of m-MTDATA and F4TCNQ, with the F4TCNQ content being 1% and a thickness of 9 nm. The second light-emitting unit 14 includes a second hole transport layer 141, a second blocking layer 142, a second light-emitting layer 143, a second hole blocking layer 144, a second electron transport layer 145, and an electron injection layer 146. The second hole transport layer 141 is made of m-MTDATA and has a thickness of 8nm. The second blocking layer 142 is made of NPB and has a thickness of 35nm. The second light-emitting layer 143 is a mixture of the aforementioned structures 1 and 2, with the structure 2 comprising 5% of the structure 2. The second light-emitting layer 143 is made of TPBI and has a thickness of 5nm. The second hole blocking layer 144 is made of TPBI and has a thickness of 5nm. The second electron transport layer 145 is a mixture of BCP and 8-hydroxyquinoline-lithium (Liq) in a 1:1 ratio and has a thickness of 35nm. The electron injection layer 146 is made of Yb and has a thickness of 1nm. The second electrode 15 is made of a mixture of Mg and Ag and has a thickness of 13nm. The light extraction layer 16 is made of NPB and has a thickness of 60nm.

[0104] As shown in Figure 3, the difference between the green light-emitting device 10G and the blue light-emitting device 10B is that the thickness of the first blocking layer 123 is 16 nm, and the thickness of the second blocking layer 142 is 41 mm; the first light-emitting layer 124 and the second light-emitting layer 143 are a mixture of CBP and Ir(ppy)3, and the proportion of Ir(ppy)3 is 8%. The thickness of the first light-emitting layer 124 and the second light-emitting layer 143 are both 35 nm.

[0105] As shown in Figure 3, the difference between the red light-emitting device 10R and the blue light-emitting device 10B is that the thickness of the first blocking layer 123 is 40nm, and the thickness of the second blocking layer 142 is 55mm; the first light-emitting layer 124 and the second light-emitting layer 143 are a mixture of CBP and Ir(piq)(acac), and the proportion of Ir(piq)(acac) is 2%. The thickness of the first light-emitting layer 124 is 35nm, and the thickness of the second light-emitting layer 143 is 45nm.

[0106] Figure 4 is a schematic diagram of the structure of another light-emitting substrate provided by an embodiment of the present disclosure. As shown in Figure 4, the light-emitting substrate 100 includes a red light-emitting device 110R-1, a green light-emitting device 110G-1, and a blue light-emitting device 110B-1.

[0107] For example, as shown in Figure 4, the anode 111 of the blue light-emitting device 110B-1 is indium tin oxide (ITO), and the first light-emitting unit 112 includes a hole injection layer 1121, a first hole transport layer 1122, a first blocking layer 1123, a first light-emitting layer 1124, a first hole blocking layer 1125 and a first electron transport layer 1126. The hole injection layer 1121 is a mixture of m-MTDATA and F4TCNQ, with F4TCNQ accounting for 1%, and the thickness of the hole injection layer 1121 is 10 nm; the material of the first hole transport layer 1122 is m-MTDATA, with a thickness of 30 nm; the material of the first blocking layer 1123 is NPB, with a thickness of 10 nm; the first light-emitting layer 1124 is a mixture of structural formula-1 and structural formula-2 mentioned above, with structural formula-2 accounting for 5%, and the thickness of the first light-emitting layer 1124 is 15 nm; the material of the first hole blocking layer 1125 is TPBI, with a thickness of 5 nm; the first electron transport layer 1126 is a mixture of BCP and 8-hydroxyquinoline-lithium (Liq) in a ratio of 1:1, and the thickness of the first electron transport layer 1126 is 15 nm. Charge generation layer 113 includes an n-type charge generation layer 1132 and a p-type charge generation layer 1131. The n-type charge generation layer 1132 is a mixture of BCP and Yb, with the Yb content being 0.5% and a thickness of 9 nm. The p-type charge generation layer 1131 is a mixture of m-MTDATA and F4TCNQ, with the F4TCNQ content being 1% and a thickness of 9 nm. The second light-emitting unit 114 includes a second hole transport layer 1141, a second blocking layer 1142, a second light-emitting layer 1143, a second hole blocking layer 1144, a second electron transport layer 1145, and an electron injection layer 1146. The second hole transport layer 1141 is made of m-MTDATA and has a thickness of 8 nm. The second blocking layer 1142 is a mixture of NPB and the compound of formula 2 described above, with formula 2 accounting for 0.5% and a thickness of 35 nm. The second light-emitting layer 1143 is a mixture of the compounds of formulas 1 and 2 described above, with formula 2 accounting for 5% and a thickness of 15 nm. The second hole blocking layer 1144 is made of TPBI and has a thickness of 5 nm. The second electron transport layer 1145 is a mixture of BCP and 8-hydroxyquinoline-lithium (Liq) in a 1:1 ratio and has a thickness of 35 nm. The electron injection layer 1146 is made of Yb and has a thickness of 1 nm. The second electrode 115 is made of a mixture of Mg and Ag and has a thickness of 13 nm. The light extraction layer 116 is made of NPB and has a thickness of 60 nm.

[0108] As shown in Figure 4, the difference between the green light-emitting device 110G-1 and the blue light-emitting device 110B-1 is that the thickness of the first blocking layer 1123 of the green light-emitting device 110G-1 is 16 nm, the second blocking layer 1142 is a mixture of NPB and Ir(ppy)3, the proportion of Ir(ppy)3 is 0.5%, and the thickness of the second blocking layer 1142 is 41 nm; the first light-emitting layer 1124 and the second light-emitting layer 1143 are a mixture of CBP and Ir(ppy)3, the proportion of Ir(ppy)3 is 8%, and the thickness of the first light-emitting layer 1124 and the second light-emitting layer 1143 are both 35 nm.

[0109] As shown in Figure 4, the difference between the red light-emitting device 110R-1 and the blue light-emitting device 110B-1 is that the thickness of the first blocking layer 1123 of the red light-emitting device 110R-1 is 40nm, the second blocking layer 1142 is a mixture of NPB and Ir(piq)(acac), the proportion of Ir(piq)(acac) is 0.5%, and the thickness of the second blocking layer 1142 is 55mm; the first light-emitting layer 1124 and the second light-emitting layer 1143 are a mixture of CBP and Ir(piq)(acac), the proportion of Ir(piq)(acac) is 2%, the thickness of the first light-emitting layer 1124 is 35nm, and the thickness of the second light-emitting layer 1143 is 45nm.

[0110] Figure 5 is a schematic diagram of the structure of another light-emitting substrate provided by an embodiment of the present disclosure. As shown in Figure 5, the light-emitting substrate 100 includes a red light-emitting device 110R-2, a green light-emitting device 110G-2, and a blue light-emitting device 110B-2.

[0111] For example, as shown in FIG5 , the blue light-emitting device 110B-2 of this example differs from the blue light-emitting device 110B-1 of the light-emitting substrate shown in FIG4 in that this blue light-emitting device 110B-2 further includes a third blocking layer 1147, which is located between the second blocking layer 1142 and the second hole transport layer 1141. The second blocking layer 1142 of the blue light-emitting device 110B-2 of this example is a mixture of NPB and the compound of formula 2 described above, with the compound of formula 2 accounting for 0.5%. The thickness of the second blocking layer 1142 is 15 nm. The material of the third blocking layer 1147 of the blue light-emitting device 110B-2 of this example is NPB and the thickness is 20 nm.

[0112] For example, as shown in FIG5 , the green light-emitting device 110G-2 of this example differs from the green light-emitting device 110G-1 of the light-emitting substrate shown in FIG4 in that the green light-emitting device 110G-2 further includes a third blocking layer 1147, which is located between the second blocking layer 1142 and the second hole transport layer 1141. The second blocking layer 1142 of the green light-emitting device 110G-2 of this example is a mixture of NPB and Ir(ppy)3, with the Ir(ppy)3 content being 0.5%, and the thickness of the second blocking layer 1142 is 21 nm. The third blocking layer 1147 of the blue light-emitting device 110B-2 of this example is made of NPB and has a thickness of 20 nm.

[0113] For example, as shown in FIG5 , the red light-emitting device 110R-2 of this example differs from the red light-emitting device 110R-1 of the light-emitting substrate shown in FIG4 in that this red light-emitting device 110R-2 further includes a third blocking layer 1147, which is located between the second blocking layer 1142 and the second hole transport layer 1141. The second blocking layer 1142 of the red light-emitting device 110R-2 of this example is a mixture of NPB and Ir(piq)(acac), with the Ir(piq)(acac) content being 0.5%. The thickness of the second blocking layer 1142 is 35 nm. The material of the third blocking layer 1147 of the red light-emitting device 110R-2 of this example is NPB, and the thickness is 20 nm.

[0114] Table 1 is a comparison table of the optical properties of the light-emitting substrates in Figures 3 to 5. As shown in Figures 3 to 5 and Table 1, the second barrier layer 1142 of the red light-emitting device 110R-1, the green light-emitting device 110G-1, and the blue light-emitting device 110B-1 shown in Figure 4 are all doped with the same material as the luminescent guest material of the second light-emitting layer 1143. The second barrier layer 1142 of the red light-emitting device 110R-2, the green light-emitting device 110G-2, and the blue light-emitting device 110B-2 shown in Figure 5 are all doped with the same material as the luminescent guest material of the second light-emitting layer 1143. Comparing the luminescent properties of Figures 3 to 5, the external quantum efficiency (EQE) and lifetime of the light-emitting devices shown in Figures 4 and 5 are both improved. Therefore, by doping the second barrier layer 1142 of each color light-emitting device with the same material as the luminescent guest material of the second light-emitting layer 1143, the luminous efficiency and lifetime of each color light-emitting device can be improved.

[0115] Table 1

[0116] The light-emitting substrate provided in an embodiment of the present disclosure can obtain a better top emission spectrum by making the ratio of the distance between the first light-emitting layer and the first electrode of the first light-emitting unit of each light-emitting device to the distance between the first electrode and the second electrode meet the value range described above, and making the ratio of the distance between the second light-emitting layer and the second electrode of the second light-emitting unit to the distance between the first electrode and the second electrode meet the value range described above. Figure 6 is a schematic diagram of the light emission spectrum of a light-emitting substrate provided in an embodiment of the present disclosure. As shown in Figure 6, the red light-emitting device, green light-emitting device and blue light-emitting device of the light-emitting substrate do not have wide shoulder peaks in the corresponding red, green and blue regions, and have a good light emission spectrum.

[0117] FIG7 is a schematic diagram of the structure of another light-emitting substrate according to an embodiment of the present disclosure. As shown in FIG7 , this light-emitting substrate 100 differs from the light-emitting substrate shown in FIG2 in that the first light-emitting unit 112 of this light-emitting substrate 100 further includes a fourth barrier layer 1127. Fourth barrier layer 1127 is located on a side of the first barrier layer 1123 away from the first light-emitting layer 1124. The first barrier layer 1123 includes a blocking host material and a blocking guest material doped within the blocking host material, while fourth barrier layer 1127 is not doped with the blocking guest material. In this example, after the first blocking layer 1123 is doped with a blocking guest material, for example, when the blocking guest material is the same as the first luminescent guest material of the first luminescent layer 1124, the first blocking layer 1123 emits weak light. At this time, the ratio of the distance between the first blocking layer 1123 and the first electrode 111 to the distance between the first electrode 111 and the second electrode 115 is within the range of 10%-30%. This allows the peaks of the multiple beams of light emitted by the first luminescent layer, the first blocking layer, and the second luminescent layer to overlap to form interference peaks. This effectively ensures the interference effect of the multiple beams of light between the first electrode and the second electrode, thereby improving the brightness and luminous efficiency of the light-emitting device. Furthermore, the doped blocking guest material can also react with excitons at the interface between the first luminescent layer 1124 and the first blocking layer 1123, reducing the loss of luminous brightness and the reduction of luminous efficiency caused by quenching. For example, when the doped blocking guest material interacts with excitons to emit light, it can also improve the brightness of the light-emitting device 110 and the exciton utilization rate without affecting the light color of the light-emitting device 110; on the other hand, the doped blocking guest material can also avoid the destruction of the blocking host material of the first blocking layer 1123 by electrons, which can increase the life of the first blocking layer 1123, and thus increase the service life of the light-emitting device 110.

[0118] The thickness of the first barrier layer 1123 of the first light-emitting unit 112 of the light-emitting device 110 of the same color shown in FIG7 is smaller than the thickness of the first barrier layer 1123 of the first light-emitting unit 112 of the light-emitting device 110 of the corresponding color shown in FIG2 . On the one hand, the smaller thickness of the first barrier layer 1123 not only makes it easier to ensure that the ratio of the distance between the first barrier layer 1123 and the first electrode 111 to the distance between the first electrode 111 and the second electrode 115 is within the range of 10%-30%, thereby ensuring the interference of multiple beams of light between the first electrode and the second electrode; on the other hand, the smaller thickness of the first barrier layer 1123 has a smaller amount of blocking guest material doping, which has a smaller impact on the process.

[0119] For example, the thicknesses of the first barrier layer 1123 and the fourth barrier layer 1127 of the first light emitting unit 112 of the same color light emitting device 110 shown in FIG. 7 are substantially the same as the thickness of the first barrier layer 1123 of the first light emitting unit 112 of the corresponding color light emitting device 110 shown in FIG. 2 .

[0120] The present disclosure also provides a display device. Figure 8 is a schematic diagram of a display device provided by one embodiment of the present disclosure. As shown in Figure 8, the display device 200 includes any of the aforementioned light-emitting substrates 100. Thus, the display device 200 has the same benefits as the light-emitting substrate 100, which will not be further elaborated here.

[0121] For example, the display device 200 can be any product or component with a display function, such as a television, a laptop computer, a tablet computer, a mobile phone, a navigator, a wearable device, a virtual reality device, etc.

[0122] There are a few points to note:

[0123] (1) The drawings of the embodiments of the present disclosure only relate to the structures related to the embodiments of the present disclosure, and other structures may refer to conventional designs.

[0124] (2) Unless there is any conflict, the features of the same embodiment and different embodiments of the present disclosure may be combined with each other.

[0125] The above are only specific embodiments of the present disclosure, but the scope of protection of the present disclosure is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this disclosure should be included in the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope of protection of the claims.

Claims

1. A light-emitting substrate comprising at least one light-emitting device, wherein: Each of the light emitting devices comprises: a first electrode; a second electrode; a first light-emitting unit, located between the first electrode and the second electrode; a second light-emitting unit, located between the first light-emitting unit and the second electrode; and a charge generation layer, located between the first light-emitting unit and the second light-emitting unit, The first light-emitting unit includes a first light-emitting layer and a first blocking layer located on a side of the first light-emitting layer close to the first electrode; the second light-emitting unit includes a second light-emitting layer and a second blocking layer located on a side of the second light-emitting layer away from the second electrode; the material of the second blocking layer includes a blocking host material and a blocking guest material doped in the blocking host material; The light-emitting side of the light-emitting substrate is located on a side of the second electrode away from the first electrode, and the ratio of the distance between the second light-emitting layer and the second electrode to the distance between the first electrode and the second electrode is in a range of 10% to 25%. The ratio of the distance between the first light-emitting layer and the first electrode to the distance between the first electrode and the second electrode is in a range of 10% to 30%.

2. The light-emitting substrate according to claim 1, wherein The at least one light-emitting substrate includes a red light-emitting device, a green light-emitting device, and a blue light-emitting device. The ratio of the distance between the second light-emitting layer and the second electrode of the red light-emitting device to the distance between the first electrode and the second electrode of the red light-emitting device is R1, the ratio of the distance between the second light-emitting layer and the second electrode of the green light-emitting device to the distance between the first electrode and the second electrode of the green light-emitting device is R2, and the ratio of the distance between the second light-emitting layer and the second electrode of the blue light-emitting device to the distance between the first electrode and the second electrode of the blue light-emitting device is R3, and R1≤R2≤R3.

3. The light-emitting substrate according to claim 2, wherein A ratio R1 of the distance between the second light-emitting layer and the second electrode of the red light-emitting device to the distance between the first electrode and the second electrode of the red light-emitting device ranges from 10% to 15%.

4. The light-emitting substrate according to claim 2, wherein A ratio R2 of the distance between the second light-emitting layer and the second electrode of the green light-emitting device to the distance between the first electrode and the second electrode of the green light-emitting device ranges from 15% to 19%.

5. The light-emitting substrate according to claim 2, wherein A ratio R3 of the distance between the second light-emitting layer and the second electrode of the blue light-emitting device to the distance between the first electrode and the second electrode of the blue light-emitting device ranges from 19% to 25%.

6. The light-emitting substrate according to any one of claims 2 to 5, wherein: The material of the second light-emitting layer includes a second light-emitting host material and a second guest material doped in the second light-emitting host material. A content of the blocking guest material in the second blocking layer is less than a content of the second guest material in the second light-emitting layer.

7. The light-emitting substrate according to claim 6, wherein The content of the blocking guest material in the second blocking layer is less than 2%, The content of the second guest material in the second light-emitting layer of the red light-emitting device is in the range of 2%-5%, the content of the second guest material in the second light-emitting layer of the green light-emitting device is in the range of 6%-10%, and the content of the second guest material in the second light-emitting layer of the blue light-emitting device is in the range of 4%-7%.

8. The light-emitting substrate according to claim 6, wherein The blocking guest material of the second blocking layer is the same as the second guest material of the second light emitting layer.

9. The light-emitting substrate according to any one of claims 1 to 5, wherein: The first blocking layer is not doped with a blocking guest material.

10. The light-emitting substrate according to any one of claims 1 to 5, wherein: The material of the first light-emitting layer includes a first light-emitting host material and a first light-emitting guest material doped in the first light-emitting host material, and the material of the first blocking layer is different from the first light-emitting host material. Materials of the second light-emitting layer include a second light-emitting host material and a second light-emitting guest material doped in the second light-emitting host material, and a blocking host material of the second blocking layer is different from the second light-emitting host material.

11. The light-emitting substrate according to any one of claims 1 to 5, wherein: The light-emitting color of the first light-emitting layer of each light-emitting device is the same as the light-emitting color of the second light-emitting layer.

12. The light-emitting substrate according to claim 11, wherein The material of the first light-emitting layer includes a first light-emitting host material and a first light-emitting guest material doped in the first light-emitting host material, and the material of the second light-emitting layer includes a second light-emitting host material and a second guest material doped in the second light-emitting host material. The first light-emitting guest material of the first light-emitting layer of each of the light-emitting devices is the same as the second light-emitting guest material of the second light-emitting layer.

13. The light-emitting substrate according to any one of claims 1 to 5, wherein: The first light-emitting unit also includes a hole injection layer, which is located between the first electrode and the first blocking layer. The material of the hole injection layer includes a p-type dopant and a hole transport material. The hole transport material includes at least one of aromatic amines, dimethylfluorene or carbazole materials. The p-type dopant includes at least one of hexacyanohexaazatriphenylene, 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane, and 1,2,3-tris[(cyano)(4-cyano-2,3,5,6-tetrafluorophenyl)methylene]cyclopropane.

14. The light-emitting substrate according to claim 13, wherein The first light-emitting unit further includes a first hole transport layer, which is located between the hole injection layer and the first blocking layer. The second light-emitting unit further includes a second hole transport layer, which is located between the charge generation layer and the second blocking layer. The materials of the first hole transport layer and the second hole transport layer include at least one of aromatic amines, dimethylfluorene, or carbazole materials having hole transport properties.

15. The light-emitting substrate according to any one of claims 1 to 5, wherein: The material of the first blocking layer and the blocking host material of the second blocking layer include at least one of aromatic amines, dimethylfluorene, or carbazole materials having hole transport properties.

16. The light-emitting substrate according to any one of claims 2 to 5, wherein: The material of the first light-emitting layer includes a first light-emitting host material and a first light-emitting guest material doped in the first light-emitting host material, and the material of the second light-emitting layer includes a second light-emitting host material and a second guest material doped in the second light-emitting host material. The first luminescent guest material and the second luminescent guest material of the blue light-emitting device include at least one of pyrene derivatives, anthracene derivatives, fluorene derivatives, perylene derivatives, styrylamine derivatives, and metal complexes; the first luminescent guest material and the second luminescent guest material of the green light-emitting device include at least one of coumarin dyes, quinacridone copper derivatives, polycyclic aromatic hydrocarbons, diamine anthracene derivatives, carbazole derivatives, and metal complexes; the first luminescent guest material and the second luminescent guest of the red light-emitting device include at least one of DCM series materials and metal complexes.

17. The light-emitting substrate according to any one of claims 1 to 5, wherein: The first light-emitting unit further includes a first hole blocking layer and a first electron transport layer, wherein the first hole blocking layer is located between the first light-emitting layer and the charge generation layer, and the first electron transport layer is located between the first hole blocking layer and the charge generation layer. The second light-emitting unit further includes a second hole blocking layer and a second electron transport layer, the second hole blocking layer is located between the second light-emitting layer and the second electrode, and the second electron transport layer is located between the second hole blocking layer and the second electrode. Materials of the first hole blocking layer, the second hole blocking layer, the first electron transport layer, and the second electron transport layer include at least one of aromatic heterocyclic compounds.

18. The light-emitting substrate according to any one of claims 1 to 5, wherein: The charge generation layer includes a p-type charge generation layer and an n-type charge generation layer stacked together, wherein the p-type charge generation layer is located between the n-type charge generation layer and the second light emitting unit. The material of the p-type charge generation layer includes at least one of aromatic amines, dimethylfluorene, or carbazole materials, and the material of the n-type charge generation layer includes an aromatic heterocyclic compound.

19. The light-emitting substrate according to any one of claims 1 to 5, wherein: The second light emitting unit further includes a third blocking layer, the third blocking layer being located between the second blocking layer and the charge generation layer, and the third blocking layer being not doped with a blocking guest material.

20. A display device comprising the light-emitting substrate according to any one of claims 1 to 19.

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