Display substrate and display device

Abstract

The present disclosure provides a display substrate and a display device. The display substrate comprises: a base substrate; a pixel defining layer, which is arranged on one side of the base substrate and is provided with a plurality of pixel openings; at least two light-emitting devices having different colors, each light-emitting device comprising a first electrode, a light-emitting structure layer and a second electrode which are sequentially stacked in a direction away from the base substrate, a part of the light-emitting structure layer of each light-emitting device being located on the side of the pixel defining layer away from the base substrate, and the other part of the light-emitting structure layer of each light-emitting device being located in a pixel opening; and an isolation structure, which is located on the side of the pixel defining layer away from the base substrate and is located between the two light-emitting devices having different colors. The display substrate of the present disclosure has the advantages of low power consumption and low risk of crosstalk between pixels.

Description

Display substrate and display device Technical Field

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

[0002] In recent years, organic electroluminescent displays (OLEDs), a new type of flat-panel display, have garnered increasing attention. Their active illumination, high brightness, high resolution, wide viewing angle, fast response, low energy consumption, and flexibility have made them a popular mainstream display product in the market.

[0003] In organic electroluminescent displays, sub-pixels of different colors require different voltages. When a high-voltage sub-pixel is turned on, the lateral flow of charge can easily cause a low-voltage sub-pixel to turn on, resulting in color crosstalk and affecting the display effect. Summary of the Invention

[0004] The present disclosure aims to solve at least one of the technical problems existing in the prior art, and proposes a display substrate and a display device.

[0005] In order to achieve the above object, according to one aspect of the present disclosure, a display substrate is provided, comprising:

[0006] substrate;

[0007] A pixel defining layer, the pixel defining layer being disposed on one side of the base substrate and having a plurality of pixel openings;

[0008] at least two light-emitting devices of different colors, the light-emitting devices comprising a first electrode, a light-emitting structure layer, and a second electrode stacked sequentially in a direction away from the base substrate, a portion of the light-emitting structure layer of the light-emitting devices being located on a side of the pixel defining layer away from the base substrate, and another portion of the light-emitting structure layer of the light-emitting devices being located within the pixel opening;

[0009] An isolation structure is located on a side of the pixel defining layer away from the base substrate, and the isolation structure is located between the two light-emitting devices of different colors.

[0010] In some optional embodiments, the light-emitting structure layer includes a plurality of stacked light-emitting layers, with at least one charge generation layer between two adjacent stacked light-emitting layers, and the isolation structure is located at least between the charge generation layers of the two light-emitting devices of different colors.

[0011] In some optional embodiments, the charge generating layer includes a first charge generating layer and a second charge generating layer arranged in a stacked manner, the first charge generating layer is closer to the substrate relative to the second charge generating layer, and the electrical properties of the charges generated by the first charge generating layer are different from those of the charges generated by the second charge generating layer.

[0012] In some optional embodiments, one of the first charge generation layer and the second charge generation layer is an electron generation layer, and the other is a hole generation layer, and the thickness of the hole generation layer is less than or equal to the thickness of the electron generation layer.

[0013] In some optional embodiments, a ratio of the thickness of the hole generation layer to the thickness of the electron generation layer is greater than or equal to 0.5 and less than or equal to 1.

[0014] In some optional embodiments, one of the first charge generation layer and the second charge generation layer is an electron generation layer, and the other is a hole generation layer, and the mass proportion of the hole dopant in the hole generation layer is greater than or equal to the mass proportion of the electron dopant in the electron generation layer.

[0015] In some optional embodiments, the mass ratio X1 of the hole dopant in the hole generation layer and the mass ratio X2 of the electron dopant in the electron generation layer satisfy 10≤X1 / X2≤30.

[0016] In some optional embodiments, the orthographic projection of the light emitting layer on the base substrate is located within the orthographic projection of the pixel opening on the base substrate.

[0017] In some optional embodiments, a thickness L2 of the light emitting structure layer located on a side of the pixel defining layer away from the base substrate is smaller than a thickness L1 of the isolation structure.

[0018] In some optional embodiments, a thickness L2 of the light emitting structure layer located on a side of the pixel defining layer away from the base substrate and a thickness L1 of the isolation structure satisfy: L1 / L2<15.

[0019] In some optional embodiments, the first electrode and the second electrode of the light-emitting device 30 form an optical resonant cavity, and the thickness L2 of the light-emitting structure layer located on the side of the pixel defining layer away from the base substrate and the thickness L1 of the isolation structure satisfy the following: 8<L1 / L2<15, so that the light emitted from the light-emitting structure layer is emitted from the second electrode during the first period and the second period of the optical resonant cavity.

[0020] In some optional embodiments, the first electrode and the second electrode of the light-emitting device 30 form an optical resonant cavity, and the thickness L2 of the light-emitting structure layer located on the side of the pixel defining layer away from the base substrate and the thickness L1 of the isolation structure satisfy: 3<L1 / L2<10, so that the light emitted from the light-emitting structure layer is emitted from the second electrode during the second period and the third period of the optical resonant cavity.

[0021] In some optional embodiments, the second electrodes of the two light-emitting devices of different colors are connected to form a second electrode layer, and a portion of the second electrode layer is located on a side of the isolation structure away from the base substrate.

[0022] In some optional embodiments, the isolation structure includes a first surface and a second surface arranged opposite to each other, the first surface is located on a side of the second surface close to the base substrate, and the orthographic projection of the second surface on the base substrate covers and exceeds the orthographic projection of the first surface on the base substrate.

[0023] In some optional embodiments, the cross-sectional area of ​​the isolation structure in a direction parallel to the substrate gradually decreases toward the substrate.

[0024] In some optional embodiments, an orthographic projection of the isolation structure on the base substrate does not overlap with an orthographic projection of the pixel opening on the base substrate.

[0025] In some optional embodiments, the isolation structure further includes a connecting side surface connecting the first surface and the second surface, the pixel defining layer includes a first defining surface and a second defining surface arranged opposite to each other, and a defining side surface connecting the first defining surface and the second defining surface, the second defining surface includes a contact sub-surface in contact with the isolation structure and a spacer sub-surface located outside the contact sub-surface, and the angle θ1 between the connecting side surface and the spacer sub-surface is greater than the angle θ2 between the defining side surface and the first defining surface.

[0026] In some optional embodiments, the angle θ1 between the connecting side surface and the spacer surface and the angle θ2 between the defining side surface and the first defining surface satisfy: θ1 / θ2≥2.

[0027] According to another aspect of the present disclosure, a display device is provided, including the above-mentioned display substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following detailed description, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0029] FIG1 is a schematic structural diagram of a display substrate according to an optional embodiment of the present disclosure;

[0030] FIG2 is a schematic diagram showing the positional relationship among the base substrate, the pixel defining layer, the isolation structure and the light emitting structure layer in FIG1 ;

[0031] FIG3 is a schematic diagram showing the positional relationship among the substrate, the pixel defining layer and the isolation structure in FIG1 ;

[0032] FIG4 shows an angled view of the isolation structure in FIG1 ;

[0033] FIG. 5 is a schematic diagram showing the positional relationship between the isolation structure and the pixel defining layer in FIG. 1 .

[0034] 10. Base substrate; 20. Pixel defining layer; 21. Pixel opening; 22. First defining surface; 23. Second defining surface; 231. Contact sub-surface; 232. Spacer sub-surface; 24. Defined side; 30. Light-emitting device; 40. First electrode; 50. Light-emitting structure layer; 51. Light-emitting layer; 52. Charge generation layer; 521. First charge generation layer; 522. Second charge generation layer; 523. First charge transport layer; 524. Second charge transport layer; 525. First charge blocking layer; 53. Charge injection layer; 54. Third charge transport layer; 55. Fourth charge transport layer; 56. Second charge blocking layer; 60. Second electrode; 70. Isolation structure; 71. First surface; 72. Second surface; 73. Connecting side; 80. Second electrode layer. DETAILED DESCRIPTION

[0035] The following describes the specific embodiments of the present disclosure in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present disclosure and are not intended to limit the present disclosure.

[0036] 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.

[0037] Unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present disclosure should have the usual meanings understood by people with ordinary skills in the field to which the present disclosure belongs. The "first", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "include" or "comprise" mean that the elements or objects appearing before 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. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0038] As used herein, "parallel" and "perpendicular" include the conditions described and conditions similar to the conditions described, and the range of the similar conditions is within an acceptable deviation range, wherein the acceptable deviation range is determined by a person of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of the specific quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, wherein the acceptable deviation range for approximate parallelism can be, for example, a deviation within 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, wherein the acceptable deviation range for approximate perpendicularity can also be, for example, a deviation within 5°.

[0039] It will be understood that when a layer or element is referred to as being on another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may be present therebetween.

[0040] Exemplary embodiments are described herein with reference to cross-sectional and / or plan views that are idealized exemplary drawings. In the drawings, the thicknesses of layers and regions are exaggerated for clarity. Therefore, variations in shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are contemplated. Therefore, the exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but rather include deviations in shape due to, for example, manufacturing. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the actual shape of regions of the device and are not intended to limit the scope of the exemplary embodiments.

[0041] Figure 1 shows a schematic diagram of a display substrate of an optional embodiment of the present disclosure. As can be seen from Figure 1, the display substrate includes a base substrate 10, a pixel defining layer 20, an isolation structure 70 and at least two light-emitting devices 30 of different colors. The pixel defining layer 20 is arranged on one side of the base substrate 10, and the pixel defining layer 20 has a plurality of pixel openings 21.

[0042] In an embodiment of the present disclosure, the light-emitting device 30 includes a first electrode 40, a light-emitting structure layer 50, and a second electrode 60 stacked sequentially in a direction away from the base substrate 10. A portion of the light-emitting structure layer 50 of the light-emitting device 30 is located on a side of the pixel defining layer 20 away from the base substrate 10, and another portion of the light-emitting structure layer 50 of the light-emitting device 30 is located within the pixel opening 21.

[0043] It should be noted that the isolation structure 70 is located on the side of the pixel defining layer 20 away from the base substrate 10. The isolation structure 70 is located between the two light-emitting devices 30 of different colors and is configured to block the movement of charges between the light-emitting structure layers 50 of the two light-emitting devices 30 of different colors. By providing the isolation structure 70 between the two light-emitting devices 30 of different colors, the isolation structure 70 can block the movement of charges between the two light-emitting structure layers 50 of different colors, thereby avoiding crosstalk between the two light-emitting devices 30 of different colors and improving the display effect of the display substrate.

[0044] In some optional embodiments, referring to FIG. 1 , the light-emitting structure layer 50 includes multiple stacked light-emitting layers 51, with at least one charge generation layer 52 located between two adjacent stacked light-emitting layers 51. An isolation structure 70 is located between the charge generation layers 52 of at least two light-emitting devices 30 of different colors to prevent charge from migrating between the charge generation layers 52 of the two light-emitting devices 30 of different colors. The provision of multiple stacked light-emitting layers 51 can improve the luminous efficiency and lifespan of the light-emitting devices 30. Since the material of the charge generation layer 52 has excellent lateral conductivity, disposing the isolation structure 70 between the charge generation layers 52 of two adjacent light-emitting devices 30 of different colors effectively prevents crosstalk between the light-emitting devices 30 of different colors.

[0045] It should be noted that an open mask evaporation process is used to produce the charge generation layer 52 in the present disclosure. If there is no isolation structure 70, the charge generation layers 52 of all light-emitting devices 30 are connected together. The minimum voltage required to turn on sub-pixels of different colors is different. When the high-voltage sub-pixel is turned on, the charge will flow laterally to the adjacent low-voltage sub-pixel position, thereby causing the low-voltage sub-pixel that does not need to emit light to turn on, causing crosstalk between the light-emitting devices 30, affecting the display effect. The present disclosure provides an isolation structure 70 to at least isolate the charge generation layer 52 to prevent the charge from flowing laterally to the adjacent low-voltage sub-pixel position, thereby avoiding crosstalk.

[0046] For example, the display substrate includes light-emitting devices 30 of multiple colors, specifically red, green and blue light-emitting devices 30. The operating voltages of the three colors of light-emitting devices 30 are different. For example, the operating voltage of the red light-emitting device 30 is lower than that of the blue light-emitting device 30. If there is no isolation structure 70, when the blue light-emitting device 30 is working, the charge will flow laterally to the position of the red light-emitting device 30. Since the operating voltage at the position of the red light-emitting device 30 is low, part of the charge flows to the position of the red light-emitting device 30 and reaches the operating voltage of the red light-emitting device 30, causing the red light-emitting device 30 to work, while the red light-emitting device 30 at this position is not required to work, thereby causing color crosstalk.

[0047] It should be noted that the operating voltage refers to the minimum voltage required for the light emitting device 30 of that color to be illuminated.

[0048] Since the operating voltage of light-emitting devices 30 of the same color is the same, even if some charge flows to the position of a light-emitting device 30 of the same color that does not need to work, it will not cause the light-emitting device 30 of the same color to work. For example, when the first blue light-emitting device 30 is working, the second blue light-emitting device 30 adjacent to the first blue light-emitting device 30 does not need to work. Even if charge flows to the position of the second blue light-emitting device 30, due to the smaller amount of charge, the drifted charge cannot reach the operating voltage of the second blue light-emitting device 30. Therefore, the second blue light-emitting device 30 will not work, and thus no crosstalk will be generated between pixels of the same color. Therefore, the isolation structure 70 can be set only between two light-emitting devices 30 of different colors, and the isolation structure 70 can be set between light-emitting devices 30 of the same color, or it can be set without the isolation structure 70. There is no specific limitation here.

[0049] In the present disclosure, referring to FIG1 , the orthographic projection of the light-emitting layer 51 on the base substrate 10 is located within the orthographic projection of the pixel opening 21 on the base substrate 10. In other words, the light-emitting structure layer 50 located within the pixel opening 21 includes the light-emitting layer 51, while the light-emitting structure layer 50 located on the side of the pixel-defining layer 20 away from the base substrate 10 does not. This arrangement allows the area of ​​the display substrate with the pixel opening 21 to emit light, while the area outside the pixel opening 21 does not emit light, thus preventing crosstalk.

[0050] In some optional embodiments, referring to Figures 1 to 3 , the orthographic projection of the isolation structure 70 on the substrate does not overlap with the orthographic projection of the pixel opening 21 on the substrate. This arrangement prevents the isolation structure 70 from blocking the light-emitting layer 51, thereby ensuring that the pixel opening 21 has sufficient effective light-emitting area.

[0051] In some optional embodiments, referring to Figures 1 and 2, the charge generation layer 52 includes a first charge generation layer 521 and a second charge generation layer 522 arranged in a stacked manner, with the first charge generation layer 521 being closer to the substrate 10 than the second charge generation layer 522. The first charge generation layer 521 is configured to generate a first type of charge, while the second charge generation layer 522 is configured to generate a second type of charge. The first and second charges have opposite electrical properties, with the first type of charge being opposite to that of the first electrode 40, while the second type of charge being opposite to that of the second electrode 60. One of the first and second charge generation layers 521, 522 is an electron generation layer, while the other is a hole generation layer. For example, if the light-emitting layer 51 comprises two layers, with a charge generation layer 52 located between the two layers, when the first electrode 40 is an anode and the second electrode 60 is a cathode, the first charge generation layer 521 is an electron generation layer, while the second charge generation layer 522 is a hole generation layer. On the contrary, when the first electrode 40 is a cathode and the second electrode 60 is an anode, the first charge generation layer 521 is a hole generation layer and the second charge generation layer 522 is an electron generation layer. No specific restrictions are made here, and it is only necessary to ensure that electrons and holes are combined in the light-emitting layer 51.

[0052] Optionally, when the light-emitting layer 51 is multi-layer, there is a charge generating layer 52 between each adjacent layer, and each charge generating layer 52 includes a first charge generating layer 521 and a second charge generating layer 522 stacked in a direction away from the substrate, and the electrical properties of the multiple first charge generating layers 521 are the same, and the electrical properties of the multiple second charge generating layers 522 are the same, or in other words, in the charge generating layers 52 in each layer, the first charge generating layer 521 is close to the first electrode 40 relative to the second charge generating layer 522, so that the electrical properties in the first charge generating layer 521 are opposite to those of the first electrode 40.

[0053] In some alternative embodiments, one of the first charge generation layer 521 and the second charge generation layer 522 is an electron generation layer, and the other is a hole generation layer, where the thickness of the hole generation layer is less than or equal to the thickness of the electron generation layer. Controlling the thickness relationship between the hole generation layer and the electron generation layer facilitates controlling the balance between electrons and holes, thereby ensuring good luminous efficiency and long life for the display substrate.

[0054] In some optional embodiments, the ratio of the thickness of the hole generation layer to the thickness of the electron generation layer is greater than or equal to 0.5 and less than or equal to 1. If the ratio of the thickness of the hole generation layer to the thickness of the electron generation layer is less than 0.5, the hole generation layer becomes thin, the number of holes generated is small, resulting in an imbalance between the number of electrons and holes, and the region where electrons and holes recombine is not located in the central region of the light-emitting layer 51, resulting in low luminous efficiency and a short lifespan of the light-emitting layer 51. If the ratio of the thickness of the hole generation layer to the thickness of the electron generation layer is greater than 1, the hole generation layer becomes thick, the number of holes generated is large, resulting in an imbalance between the number of electrons and holes, and the region where electrons and holes recombine is not located in the central region of the light-emitting layer 51, resulting in low luminous efficiency and a short lifespan of the light-emitting layer 51. Limiting the ratio of the thickness of the hole generation layer to the thickness of the electron generation layer to the thickness of the electron generation layer to within the range of 0.5 to 1 facilitates a balance between electrons and holes, placing the region where electrons and holes recombine closer to the central region of the light-emitting layer 51, thereby improving the luminous efficiency and lifespan of the light-emitting layer 51. For example, if the thickness of the hole-generating layer is 10 nm and the thickness of the electron-generating layer is 14 nm, the ratio of the thickness of the hole-generating layer to the thickness of the electron-generating layer is 0.71. For another example, if the thickness of the hole-generating layer is 9 nm and the thickness of the electron-generating layer is 9 nm, the ratio of the thickness of the hole-generating layer to the thickness of the electron-generating layer is 1.

[0055] In some optional embodiments, one of the first charge generation layer 521 and the second charge generation layer 522 is an electron generation layer, and the other of the first charge generation layer 521 and the second charge generation layer 522 is a hole generation layer. The mass fraction of the hole dopant in the hole generation layer is greater than or equal to the mass fraction of the electron dopant in the electron generation layer. By controlling the relationship between the mass fraction of the hole dopant in the hole generation layer and the mass fraction of the electron dopant in the electron generation layer, it is advantageous to control the balance of electrons and holes, thereby ensuring that the display substrate has good luminous efficiency and service life.

[0056] In some optional embodiments, the mass ratio of the hole dopant in the hole generation layer, X1, to the mass ratio of the electron dopant in the electron generation layer, X2, satisfies 10≤X1 / X2≤30. If the ratio of the mass ratio of the hole dopant in the hole generation layer, X1, to the mass ratio of the electron dopant in the electron generation layer, X2, is less than 10 or greater than 30, the number of electrons and holes is unbalanced, resulting in low luminous efficiency and short life of the light-emitting layer 51. Limiting the ratio of the mass ratio of the hole dopant in the hole generation layer, X1, to the mass ratio of the electron dopant in the electron generation layer, X2, to within the range of 10 to 30 is conducive to achieving a balance between electrons and holes, thereby improving the luminous efficiency and life of the light-emitting layer 51. For example, if the mass ratio of the hole dopant in the hole generation layer, X1, is 10%, and the mass ratio of the electron dopant in the electron generation layer, X2, is 0.5%, then X1 / X2 = 20. For another example, the mass proportion X1 of the hole dopant in the hole generation layer is 12%, and the mass proportion X2 of the electron dopant in the electron generation layer is 0.4%, then X1 / X2=30.

[0057] It should be noted that the thickness of the isolation structure 70 is greater than the thickness of the charge generation layer 52 to prevent lateral charge migration. If the charge generation layer 52 includes only the first charge generation layer 521 and the second charge generation layer 522, the thickness of the isolation structure 70 is greater than the sum of the thicknesses of the first charge generation layer 521 and the second charge generation layer 522. If the charge generation layer 52 includes the first charge generation layer 521, the second charge generation layer 522, and other structural layers, the thickness of the isolation structure 70 is greater than the total thickness of the first charge generation layer 521, the second charge generation layer 522, and other structural layers.

[0058] In some optional embodiments, referring to FIG1 and FIG2 , the charge generation layer 52 further includes a first charge transport layer 523 and a second charge transport layer 524. The first charge transport layer 523 is located on a side of the first charge generation layer 521 away from the second charge generation layer 522, and the second charge transport layer 524 is located on a side of the second charge generation layer 522 away from the first charge generation layer 521. In this case, the thickness of the isolation structure 70 is greater than the total thickness of the first charge transport layer 523, the first charge generation layer 521, the second charge generation layer 522, and the second charge transport layer 524.

[0059] In other optional embodiments, referring to Figures 1 and 2, the charge generation layer 52 further includes a first charge transport layer 523, a second charge transport layer 524, and at least one first charge blocking layer 525. The first charge blocking layer 525 is configured to block the first type of charge or the second type of charge. When the first charge blocking layer 525 is located on the side of the first charge transport layer 523 away from the first charge generation layer 521, the first charge blocking layer 525 is configured to block the second type of charge. When the first charge blocking layer 525 is located on the side of the second charge transport layer 524 away from the second charge generation layer 522, the first charge blocking layer 525 is configured to block the first type of charge. In this case, the thickness of the isolation structure 70 is greater than the total thickness of the first charge transport layer 523, the first charge generation layer 521, the second charge generation layer 522, the second charge transport layer 524, and the first charge blocking layer 525.

[0060] Optionally, the first charge blocking layer 525 may be an electron blocking layer or a hole blocking layer. Whether to block electrons or holes may be selected according to actual needs, and no specific limitation is made here.

[0061] In some optional embodiments, referring to Figures 1 and 2, the light-emitting structure layer 50 further includes a charge injection layer 53 and a third charge transport layer 54, the charge injection layer 53 and the third charge transport layer 54 are located on the side of the charge generation layer 52 facing the base substrate 10, the third charge transport layer 54 is close to the charge generation layer 52 relative to the charge injection layer 53, a light-emitting layer 51 is located between the charge generation layer 52 and the third charge transport layer 54, and the first electrode 40 is located between the charge injection layer 53 and the base substrate 10.

[0062] In some optional embodiments, referring to FIG1 and FIG2 , the light-emitting structure layer 50 further includes a fourth charge transport layer 55 and a second charge blocking layer 56. The fourth charge transport layer 55 and the second charge blocking layer 56 are located on the side of the charge generation layer 52 away from the substrate 10. The fourth charge transport layer 55 is farther away from the charge generation layer 52 than the second charge blocking layer 56. Another light-emitting layer 51 is located between the charge generation layer 52 and the second charge blocking layer 56. The second charge blocking layer 56 blocks minority carriers in the second electrode 60. For example, the second electrode 60 is a cathode, the majority carriers in the second electrode 60 are electrons, and the minority carriers are holes. In this case, the second charge blocking layer 56 blocks holes, that is, the second charge blocking layer 56 is a hole blocking layer.

[0063] Optionally, the second charge blocking layer 56 may be an electron blocking layer or a hole blocking layer. Whether to block electrons or holes may be selected according to actual needs, and no specific limitation is made here.

[0064] In the specific embodiment shown in FIG. 1 , a common layer is prepared on the first electrode 40 and the pixel defining layer 20 by an open mask evaporation method, wherein the common layer is other layers in the light emitting structure layer 50 excluding the light emitting layer 51 .

[0065] Specifically, a charge injection layer 53 and a third charge transport layer 54 are sequentially formed on the first electrode 40 and the pixel defining layer 20 by the method of Open Mask evaporation. Then, the first light-emitting layer 51 of the sub-pixels of different colors are evaporated in the pixel opening 21 by the method of FMM (Fine Metal Mask, fine metal mask plate) evaporation. Continue to form the first charge blocking layer 525, the first charge transport layer 523, the first charge generation layer 521, the second charge generation layer 522, and the second charge transport layer 524 by the method of Open Mask evaporation. Then, the second light-emitting layer 51 of the sub-pixels of different colors is evaporated in the pixel opening 21 by the method of FMM evaporation. Finally, the second charge blocking layer 56, the fourth charge transport layer 55 and the second electrode layer 80 are evaporated by Open Mask.

[0066] In some optional embodiments, the thickness L2 of the light emitting structure layer 50 on the pixel defining layer 20 is less than the thickness L1 of the isolation structure 70. This configuration allows the light emitting structure layer 50 to be disconnected by the isolation structure 70 during evaporation, so that the light emitting structure layer 50 is not connected at the location of the isolation structure 70, thereby avoiding lateral charge movement and reducing crosstalk.

[0067] It should be noted that the light-emitting structure layer 50 includes a first portion located on the pixel defining layer 20 and a second portion located in the pixel opening 21. The light-emitting layer 51 is not provided in the first portion of the light-emitting structure layer 50, and the light-emitting layer 51 is provided in the second portion of the light-emitting structure layer 50. That is to say, the thickness L2 of the light-emitting structure layer 50 located on the pixel defining layer 20 does not include the thickness of the light-emitting layer 51.

[0068] In some optional embodiments, the thickness L2 of the light-emitting structure layer 50 located on the pixel-defining layer 20 and the thickness L1 of the isolation structure 70 satisfy the following relationship: L1 / L2 < 15. If L1 / L2 is greater than or equal to 15, the thickness L1 of the isolation structure 70 is too large, which is not conducive to the thinning and lightweight display substrate. Limiting the ratio of thickness L1 to thickness L2 to less than 15 ensures that the isolation structure 70 disconnects the light-emitting structure layer 50 while facilitating the development of thinner and lighter display substrates.

[0069] The first and second electrodes of the light-emitting device 30 form an optical resonant cavity. The thickness L2 of the light-emitting structure layer 50, located on the side of the pixel-defining layer 20 away from the base substrate 10, and the thickness L1 of the isolation structure 70 satisfy the following relationship: 8 < L1 / L2 < 15. This allows light emitted from the light-emitting structure layer 50 to be emitted from the second electrode during the first and second periods of the optical resonant cavity. In other words, when L1 / L2 is greater than 8 and less than 15, the light emitted from the light-emitting structure layer 50 achieves optimal optical efficiency during the first and second periods.

[0070] Alternatively, 100nm≤L2≤160nm. 1μm≤L1≤2.5μm. For example, if L2 is 120nm and the thickness L1 of the isolation structure 70 is 1μm, then L1 / L2 = 8.3. For another example, if L2 is 125nm and L1 is 1.5μm, then L1 / L2 = 12. For another example, if L2 is 110nm and L1 is 1.5μm, then L1 / L2 = 13.63. For another example, if L2 is 100nm and L1 is 1.3μm, then L1 / L2 = 13. For another example, if L2 is 130nm and L1 is 1.3μm, then L1 / L2 = 10.

[0071] It should be noted that the optical resonant cavity has a periodic gain for light, and the first period refers to the distance over which the optical resonant cavity performs the first gain for light, and the second period refers to the distance over which the optical resonant cavity performs the second gain for light.

[0072] The first electrode and the second electrode of the light-emitting device 30 form an optical resonant cavity, and the thickness L2 of the light-emitting structure layer 50 located on the side of the pixel defining layer 20 away from the base substrate 10 and the thickness L1 of the isolation structure 70 satisfy: 3<L1 / L2<10, so that the light emitted from the light-emitting structure layer 50 is emitted from the second electrode during the second period and the third period of the optical resonant cavity.

[0073] Alternatively, 220nm≤L2≤290nm. 1μm≤L1≤2.5μm. For example, L2 is 266nm and the thickness L1 of the isolation structure 70 is 1.4μm. In this case, L1 / L2=5.3. For another example, if L2 is 250nm and L1 is 1.4μm, L1 / L2=5.6. For another example, if L2 is 230nm and L1 is 1.5μm, L1 / L2=6.52. For another example, if L2 is 280nm and L1 is 1.3μm, L1 / L2=4.64. For another example, if L2 is 290nm and L1 is 1.4μm, L1 / L2=4.8. For another example, if L2 is 270nm and the thickness L1 of the isolation structure 70 is 2μm, L1 / L2=7.41. For another example, L2 is 230 nm, the thickness L1 of the isolation structure 70 is 1.6 μm, and L1 / L2 = 6.95.

[0074] In some optional embodiments, referring to FIG. 1 , the second electrodes 60 of a plurality of light-emitting devices 30 are connected to form a second electrode layer 80, and the second electrode layer 80 is located on a side of the isolation structure 70 away from the base substrate 10. The second electrodes 60 of all light-emitting devices 30 are connected to form the second electrode layer 80, avoiding isolation by the isolation structure 70. This helps reduce the resistance of the second electrodes 60, thereby reducing the power consumption of the display substrate and improving the service life of the display substrate.

[0075] In some optional embodiments, referring to FIG. 4 and FIG. 5 , the isolation structure 70 includes a first surface 71 and a second surface 72 disposed opposite each other. The first surface 71 is located on a side of the second surface 72 closer to the base substrate 10, and the orthographic projection of the second surface 72 on the base substrate 10 overlaps and exceeds the orthographic projection of the first surface 71 on the base substrate 10. In other words, the area of ​​the first surface 71 is smaller than the area of ​​the second surface 72 to prevent the charge generation layer 52 from forming on the sidewalls of the isolation structure 70 during deposition of the charge generation layer 52. This allows the charge generation layer 52 to be disconnected at the location of the isolation structure 70, thereby preventing charge from moving between the charge generation layers 52 of different light-emitting devices 30.

[0076] In some optional embodiments, referring to Figures 1 to 5, the cross-sectional area of ​​the isolation structure 70 in a direction parallel to the base substrate 10 gradually decreases as it approaches the base substrate 10. This configuration results in the isolation structure 70 having a tapered longitudinal cross-section in a direction perpendicular to the base substrate 10, specifically, an inverted cone shape with a larger top and smaller bottom. This can reduce the formation of a continuous layer of the light-emitting structure layer 50 on the sidewalls of the isolation structure 70, facilitating the disconnection of the light-emitting structure layer 50. It should be noted that the "inverted cone shape with a larger top and smaller bottom" herein refers to the side of the isolation structure 70 facing the base substrate 10 as the bottom, and the side of the isolation structure 70 away from the base substrate 10 as the top.

[0077] In some optional embodiments, referring to Figures 4 and 5 , the isolation structure 70 further includes a connecting side surface 73 connecting the first surface 71 and the second surface 72. The pixel defining layer 20 includes a first defining surface 22 and a second defining surface 23 disposed opposite each other, and a defining side surface 24 connecting the first defining surface 22 and the second defining surface 23. The second defining surface 23 includes a contact sub-surface 231 that contacts the isolation structure 70 and a spacer sub-surface 232 located outside the contact sub-surface 231. The angle θ1 between the connecting side surface 73 and the spacer sub-surface 232 is greater than the angle θ2 between the defining side surface 24 and the first defining surface 22. By limiting the relationship between the angle θ1 between the connecting side surface 73 and the spacer sub-surface 232 and the angle θ2 between the defining side surface 24 and the first defining surface 22, the inclination angle of the connecting side surface 73 and the defining side surface 24 can be controlled, which facilitates the isolation structure to disconnect the light-emitting structure layer 50 and reduce crosstalk. This also ensures the continuity of the second electrode layer 80 and prevents disconnection.

[0078] In some optional embodiments, referring to FIG3 , the angle θ1 between the connecting side surface 73 and the spacer surface 232 is greater than the angle θ2 between the limiting side surface 24 and the first limiting surface 22, and the following relationship is satisfied: θ1 / θ2 ≥ 2. During vapor deposition of the second electrode layer 80, the second electrode layer 80 is deposited onto the second surface 72 of the isolation structure 70, the connecting side surface 73, and the pixel opening 21. The angle θ1 between the connecting side surface 73 and the spacer surface 232, and the angle θ2 between the first limiting surface 22, may affect the continuity of the second electrode layer 80. Limiting θ1 / θ2 to a range greater than or equal to 2 can ensure the continuity of the second electrode layer 80, thereby preventing an increase in resistance and reducing power consumption of the display substrate.

[0079] In some optional embodiments, the angle θ2 is less than 45°, for example, the angle θ2 is less than 40°.

[0080] For example, if the angle θ1 between the connecting side surface 73 and the spacer sub-surface 232 is 66°, and the angle θ2 between the defining side surface 24 and the first defining surface 22 is 28°, then θ1 / θ2 ≈ 2.4. For another example, if the angle θ1 between the connecting side surface 73 and the spacer sub-surface 232 is 64°, and the angle θ2 between the defining side surface 24 and the first defining surface 22 is 32°, then θ1 / θ2 = 2.

[0081] When the display substrate has only one light-emitting layer 51, the thickness L2 of the light-emitting structure layer 50 located on the pixel defining layer 20 is less than the thickness L1 of the isolation structure 70, which can still block the movement of charges between light-emitting devices 30 of different colors. Of course, the isolation structure 70 can also only disconnect the stacked layer structure between the light-emitting layer 51 and the first electrode 40, which can also reduce the problem of crosstalk. Of course, the isolation structure 70 can also only disconnect the stacked layer structure between the light-emitting layer 51 and the second electrode layer 80, which can also reduce the problem of crosstalk.

[0082] In another aspect, a display device is provided, comprising the display substrate described above. The display device disclosed herein has the advantages of low power consumption and low crosstalk between pixels.

[0083] The display device may include any device or product with a display function. For example, the display device may be a smart phone, a mobile phone, an e-book reader, a desktop computer (PC), a laptop PC, a netbook PC, a personal digital assistant (PDA), a portable multimedia player (PMP), a digital audio player, a mobile medical device, a camera, a wearable device (such as a head-mounted device, electronic clothing, an electronic bracelet, an electronic necklace, an electronic accessory, an electronic tattoo, or a smart watch), a television, etc. The above-mentioned device or product with a display function also has a foldable function.

[0084] It is understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the present disclosure, and the present disclosure is not limited thereto. Those skilled in the art may make various modifications and improvements without departing from the spirit and substance of the present disclosure, and such modifications and improvements are also considered to be within the scope of protection of the present disclosure.

Claims

1. A display substrate, wherein: include: substrate; A pixel defining layer, the pixel defining layer being disposed on one side of the base substrate and having a plurality of pixel openings; at least two light-emitting devices of different colors, the light-emitting devices comprising a first electrode, a light-emitting structure layer, and a second electrode stacked sequentially in a direction away from the base substrate, a portion of the light-emitting structure layer of the light-emitting devices being located on a side of the pixel defining layer away from the base substrate, and another portion of the light-emitting structure layer of the light-emitting devices being located within the pixel opening; An isolation structure is located on a side of the pixel defining layer away from the base substrate, and the isolation structure is located between the two light-emitting devices of different colors.

2. The display substrate according to claim 1, wherein The light emitting structure layer includes a plurality of stacked light emitting layers, at least one charge generation layer is provided between two adjacent stacked light emitting layers, and the isolation structure is located at least between the charge generation layers of the two light emitting devices of different colors.

3. The display substrate according to claim 2, wherein: The charge generating layer includes a first charge generating layer and a second charge generating layer which are stacked together. The first charge generating layer is closer to the base substrate than the second charge generating layer. The charges generated by the first charge generating layer have different electrical properties from those generated by the second charge generating layer.

4. The display substrate according to claim 3, wherein: One of the first charge generation layer and the second charge generation layer is an electron generation layer, and the other is a hole generation layer. The thickness of the hole generation layer is less than or equal to the thickness of the electron generation layer.

5. The display substrate according to claim 4, wherein: A ratio of a thickness of the hole generating layer to a thickness of the electron generating layer is greater than or equal to 0.5 and less than or equal to 1. The display substrate according to claim 3 , wherein: One of the first charge generation layer and the second charge generation layer is an electron generation layer, and the other is a hole generation layer. The mass proportion of the hole dopant in the hole generation layer is greater than or equal to the mass proportion of the electron dopant in the electron generation layer.

7. The display substrate according to claim 6, wherein: The mass ratio X1 of the hole dopant in the hole generation layer and the mass ratio X2 of the electron dopant in the electron generation layer satisfy 10≤X1 / X2≤30.

8. The display substrate according to claim 2, wherein: The orthographic projection of the light emitting layer on the base substrate is located within the orthographic projection of the pixel opening on the base substrate.

9. The display substrate according to any one of claims 1 to 8, wherein: The thickness L2 of the light emitting structure layer located on a side of the pixel defining layer away from the base substrate is smaller than the thickness L1 of the isolation structure.

10. The display substrate according to claim 9, wherein: The thickness L2 of the light emitting structure layer located on the side of the pixel defining layer away from the base substrate and the thickness L1 of the isolation structure satisfy the following relationship: L1 / L2<15.

11. The display substrate according to claim 10, wherein: The first electrode and the second electrode of the light-emitting device form an optical resonant cavity, and the thickness L2 of the light-emitting structure layer located on the side of the pixel defining layer away from the base substrate and the thickness L1 of the isolation structure satisfy the following: 8<L1 / L2<15, so that the light emitted from the light-emitting structure layer is emitted from the second electrode during the first period and the second period of the optical resonant cavity.

12. The display substrate according to claim 10, wherein: The first electrode and the second electrode of the light-emitting device form an optical resonant cavity, and the thickness L2 of the light-emitting structure layer located on the side of the pixel defining layer away from the base substrate and the thickness L1 of the isolation structure satisfy the following: 3<L1 / L2<10, so that the light emitted from the light-emitting structure layer is emitted from the second electrode during the second period and the third period of the optical resonant cavity.

13. The display substrate according to any one of claims 1 to 8, wherein: The second electrodes of the two light-emitting devices of different colors are connected to form a second electrode layer, and a portion of the second electrode layer is located on a side of the isolation structure away from the base substrate.

14. The display substrate according to any one of claims 1 to 8, wherein: The isolation structure includes a first surface and a second surface arranged opposite to each other, the first surface is located on a side of the second surface close to the base substrate, and the orthographic projection of the second surface on the base substrate covers and exceeds the orthographic projection of the first surface on the base substrate.

15. The display substrate according to claim 14, wherein: The cross-sectional area of ​​the isolation structure in a direction parallel to the substrate gradually decreases toward the substrate.

16. The display substrate according to claim 14, wherein: An orthographic projection of the isolation structure on the base substrate does not overlap with an orthographic projection of the pixel opening on the base substrate.

17. The display substrate according to claim 14, wherein: The isolation structure also includes a connecting side surface connecting the first surface and the second surface, the pixel defining layer includes a first defining surface and a second defining surface arranged opposite to each other, and a defining side surface connecting the first defining surface and the second defining surface, the second defining surface includes a contact sub-surface in contact with the isolation structure and a spacer sub-surface located outside the contact sub-surface, and the angle θ1 between the connecting side surface and the spacer sub-surface is greater than the angle θ2 between the defining side surface and the first defining surface.

18. The display substrate according to claim 17, wherein: An included angle θ1 between the connecting side surface and the spacer surface and an included angle θ2 between the limiting side surface and the first limiting surface satisfy the following: θ1 / θ2≥2.

19. A display device, wherein: A display substrate comprising the display substrate according to any one of claims 1 to 18.

Images