Display panel and display device

Abstract

The utility model provides a display panel and a display device, and belongs to the technical field of display. The display panel disclosed by the utility model comprises a substrate and a plurality of light-emitting devices arranged on the substrate, the light-emitting device comprises a plurality of light-emitting units and charge separation and generation units arranged between the adjacent light-emitting units. The plurality of light-emitting devices comprise a first light-emitting device, a second light-emitting device and a third light-emitting device; the display panel further comprises a pixel defining layer. The pixel defining layer comprises a first pixel opening corresponding to the first light-emitting device, a second pixel opening corresponding to the second light-emitting device, and a third pixel opening corresponding to the third light-emitting device; each first pixel opening comprises a first opening part and a second opening part which are sequentially arranged in the direction away from the substrate, and the opening size of the first opening part is larger than that of the second opening part; the second pixel opening comprises a third opening part and a fourth opening part which are sequentially arranged in the direction away from the substrate, and the opening size of the third opening part is larger than that of the fourth opening part; and the side wall of the third pixel opening is a flat plane.

Description

Technical Field

[0001] The present disclosure belongs to the field of display technology, and particularly relates to a display panel and a display device. Background Art

[0002] Organic electroluminescence display (OLED) has the advantages of high color saturation, low driving voltage, wide viewing angle display, flexibility, fast response speed, simple manufacturing process, etc., making OLED display panels gradually become the development trend of display devices.

[0003] For specific usage scenarios such as outdoor, higher brightness requirements are placed on light-emitting devices. Compared with single-stack OLED light-emitting devices (such as Single OLED devices), multi-stack tandem OLED light-emitting devices (Tandem OLED devices) have the characteristics of high brightness, long life, narrow half-width (high color gamut), and low power consumption, and are gradually becoming the development trend of display products for specific usage scenarios such as outdoor.

[0004] However, a charge separation generating layer (CGL layer) is arranged in the middle of the Tandem OLED device. Since the CGL layer has a strong lateral migration ability, it causes serious lateral crosstalk problems between high pixel density (Pixels Per Inch, PPI) devices, which reduces the device efficiency and worsens the high and low grayscale color deviation problem of the device. Utility Model Content

[0005] The present disclosure aims to solve at least one of the technical problems existing in the prior art and provides a display panel and a display device.

[0006] In a first aspect, the technical solution adopted to solve the technical problem of the present disclosure is a display panel, comprising a substrate substrate, and a plurality of light-emitting devices arranged on the substrate substrate; the light-emitting devices include a plurality of light-emitting units, and a charge separation generating unit arranged between adjacent light-emitting units; the plurality of light-emitting devices include a first light-emitting device, a second light-emitting device and a third light-emitting device;

[0007] The display panel further includes a pixel defining layer; the pixel defining layer includes a first pixel opening corresponding to the first light emitting device, a second pixel opening corresponding to the second light emitting device, and a third pixel opening corresponding to the third light emitting device;

[0008] The first pixel opening includes a first opening portion and a second opening portion which are sequentially arranged along a direction away from the base substrate, and the opening size of the first opening portion is larger than the opening size of the second opening portion; the second pixel opening includes a third opening portion and a fourth opening portion which are sequentially arranged along a direction away from the base substrate, and the opening size of the third opening portion is larger than the opening size of the fourth opening portion; the side wall of the third pixel opening is a flat plane.

[0009] In some embodiments, the first pixel opening further includes a fifth opening portion disposed on a side of the first opening portion away from the second opening portion; the second pixel opening further includes a sixth opening portion disposed on a side of the third opening portion away from the fourth opening portion; the centers of the first opening portion, the second opening portion and the fifth opening portion are collinear; the centers of the third opening portion, the fourth opening portion and the sixth opening portion are collinear;

[0010] The opening size of the fifth opening is smaller than or equal to the opening size of the second opening; the opening size of the sixth opening is smaller than or equal to the opening size of the fourth opening.

[0011] In some embodiments, for the adjacent first pixel opening and the third pixel opening, the shortest distance from the sidewall of the second opening to the sidewall of the third pixel opening is greater than half of the shortest distance from the fifth opening to the sidewall of the third pixel opening;

[0012] For the adjacent first pixel opening and the second pixel opening, the shortest distance from the side wall of the second opening to the side wall of the fourth opening is greater than half of the shortest distance from the side wall of the fifth opening to the side wall of the sixth opening.

[0013] In some embodiments, a third opening ratio of the third pixel opening is greater than a first opening ratio of the first pixel opening; and a third opening ratio of the third pixel opening is greater than a second opening ratio of the second pixel opening.

[0014] In some embodiments, a ratio of the third opening ratio to the first opening ratio is between 1.1 and 2; a ratio of the third opening ratio to the second opening ratio is between 1.1 and 2.

[0015] In some embodiments, the first light emitting device, the second light emitting device, and the third light emitting device all emit white light.

[0016] In some embodiments, the plurality of light emitting units include at least a first light emitting unit and a second light emitting unit, and the first light emitting unit is closer to the substrate than the second light emitting unit;

[0017] The first light-emitting unit includes a red light-emitting layer and a green light-emitting layer; the second light-emitting unit includes a blue light-emitting layer.

[0018] In some embodiments, the first light emitting device and the second light emitting device are the same.

[0019] In some embodiments, the display panel further includes a color filter layer disposed on a side of the plurality of light-emitting devices away from the base substrate, the color filter layer including a first color filter, a second color filter, and a third color filter; the first color filter is disposed corresponding to the first light-emitting device, the second color filter is disposed corresponding to the second light-emitting device, and the third color filter is disposed corresponding to the third light-emitting device;

[0020] The first color filter transmits red light, the second color filter transmits green light, and the third color filter transmits blue light.

[0021] In some embodiments, the outline shape of the orthographic projection of the third color filter on the base substrate is a regular hexagon; the outline shapes of the orthographic projections of the first color filter and the second color filter on the base substrate are irregular hexagons, and the irregular hexagons have at least two sides of different lengths;

[0022] Two adjacent first color filters and second color filters are symmetrically arranged with their contacting edges as symmetry axes;

[0023] For any of the third color filters, a plurality of the first color filters and a plurality of the second color filters are arranged around it, and the first color filters and the second color filters are alternately arranged along a direction surrounding the third color filter;

[0024] The length of the contact edge between the first color filter and the third color filter is the first side length; the length of the contact edge between the second color filter and the third color filter is the second side length; the length of the contact edge between two adjacent first color filters and the second color filter is the third side length; the first side length is equal to the second side length, and the third side length is less than the first side length.

[0025] In some embodiments, for any of the first color filters, one of the lengths of two sides disposed opposite to each other is the first length, and the other is the third length;

[0026] For any second color filter, one of the lengths of two opposite sides is the second side length, and the other is the third side length.

[0027] In some embodiments, the orthographic projection of the first color filter on the base substrate covers the orthographic projection of the second opening on the base substrate;

[0028] The orthographic projection of the second color filter on the base substrate covers the orthographic projection of the fourth opening on the base substrate.

[0029] In some embodiments, the ratio of the maximum opening size of the first opening portion to the maximum opening size of the second opening portion is in a range of 1.1 to 1.4.

[0030] In some embodiments, the material of the substrate includes silicon.

[0031] In a second aspect, an embodiment of the present disclosure further provides a display device, comprising a display panel as described in any one of the first aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1a A schematic diagram of the local structure of a pixel definition layer of a related silicon-based Tandem OLED device;

[0033] Figure 1b A schematic diagram of color coordinate shift of a related silicon-based Tandem OLED device at different grayscales;

[0034] Figure 2 A simplified diagram of a display panel provided for an embodiment of the present disclosure;

[0035] Figure 3 A schematic diagram of the structure of a display panel in Example 1 provided in an embodiment of the present disclosure;

[0036] Figure 4 A structural diagram of a pixel defining layer provided in an embodiment of the present disclosure;

[0037] Figure 5 A schematic diagram of adjacent first pixel openings and second pixel openings provided in an embodiment of the present disclosure;

[0038] Figure 6 A schematic diagram of the structure of a display panel in Example 2 provided in an embodiment of the present disclosure;

[0039] Figure 7 A schematic diagram of a white light emitting device provided in an embodiment of the present disclosure;

[0040] Figure 8a A schematic diagram of a specific structure of a display panel provided in an embodiment of the present disclosure;

[0041] Figure 8b for Figure 8a A simple diagram from a bird's-eye view;

[0042] Fig. 9 A schematic diagram of the luminous efficiency of a red sub-pixel, a green sub-pixel and a blue sub-pixel at different current densities provided by an embodiment of the present disclosure;

[0043] Fig.10 An enlarged view of an undercut structure provided for an embodiment of the present disclosure;

[0044] Fig.11 A schematic diagram of another undercut structure provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical scheme and advantages of the embodiments of the present disclosure clearer, the technical scheme in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all of the embodiments. The components of the embodiments of the present disclosure generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present disclosure provided in the drawings is not intended to limit the scope of the present disclosure for protection, but merely represents the selected embodiments of the present disclosure. Based on the embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present disclosure.

[0046] Unless otherwise defined, the technical terms or scientific terms used in the present disclosure should be 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, similar words such as "one", "one" or "the" do not indicate quantity restrictions, but indicate that there is at least one. Similar words such as "include" or "comprise" mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Similar words such as "connect" or "connected" are not limited to physical or mechanical connections, but can 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 described object changes, the relative positional relationship may also change accordingly.

[0047] The "multiple or several" mentioned in this disclosure refers to two or more. "And / or" describes the association relationship of the associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0048] In the related art, in a Tandem OLED device, different light-emitting units are connected through a CGL layer. The CGL layer is usually composed of an organic material with a high carrier transfer rate and doped with an active metal (usually Li). Under the action of an electric field, charge separation occurs in the CGL layer, electrons are transferred to the electron transport layer (ETL), holes are transferred to the hole transport layer (HTL), and composite light is generated in different light-emitting units 23. Therefore, under the same current density, the Tandem OLED device can improve the device luminescence efficiency by several times compared to the SingleOLED device.

[0049] Although Tandem OLED devices have many advantages, they also have disadvantages. Due to the strong lateral migration ability of the CGL layer, in high PPI display products (i.e., the spacing between devices is narrow), Tandem OLED devices are prone to serious lateral crosstalk problems, which reduces the efficiency of Tandem OLED devices and worsens the high and low grayscale color deviation problems of the devices.

[0050] In related technologies, such as Figure 1a As shown, it is a schematic diagram of the local structure of the pixel defining layer of the related silicon-based Tandem OLED device. The pixel defining layer PDL has a sub-pixel opening 03, and a partition structure 04 is provided between the sub-pixel openings 03 of adjacent light-emitting devices 02. The partition structure 04 (undercut) is used to separate the CGL layer to prevent adjacent light-emitting devices 02 from generating lateral crosstalk problems. However, the above structural design can only solve the crosstalk problem between the light-emitting devices 02, and cannot solve the high and low grayscale color deviation problem caused by internal leakage of the light-emitting device 02. Due to the morphology of the pixel defining layer PDL, the evaporation shadows of each film layer of the light-emitting device 02 are formed, which causes the cathode layer 22 and the CGL layer to generate more serious internal leakage of the light-emitting device 02 at the positions of Leak1 and Leak2. Due to the influence of the partition structure 04, while disconnecting the CGL layer, the film layer distortion will also be more serious, so Leak2 is also more seriously affected by the leakage than the position of Leak1. Internal leakage of the light-emitting device 02 will cause differences in the transmission speeds of electrons and holes generated in the CGL layer, thereby affecting the recombination efficiency. For example, leakage causes the blue light at the Leak1 and Leak2 positions to light up prematurely at low grayscales, and the Leak2 position is located at the intersection of the color filters corresponding to the adjacent light-emitting device 02, resulting in optical leakage, which causes the luminous intensity of the blue sub-pixel to increase, resulting in an imbalance in the ratio of red, green and blue light generated by the pixel unit, and thus causing color shift.

[0051] Figure 1b Schematic diagram of color coordinate shift of related silicon-based Tandem OLED devices at different grayscales, such as Figure 1bAs shown, affected by the characteristics of the light-emitting layer material, the internal leakage of the light-emitting device 02 causes the blue light of the blue light-emitting layer in the ultra-low grayscale, for example, 0 to 10 to light up prematurely, and as the voltage decreases, the luminescence brightness of the red light-emitting layer and the green light-emitting layer in the ultra-low grayscale 0 to 10 gradually weakens, which can be seen from the luminescence effect of the red sub-pixel and the green sub-pixel. It can be seen that the color point of the red coordinate and the color point of the green coordinate gradually move toward the 0 point, which ultimately leads to serious color deviation of the red light emitted by the red sub-pixel, the green light emitted by the green sub-pixel, and the blue light emitted by the blue sub-pixel in the low grayscale range, which is actually manifested in the uneven display screen at low grayscale.

[0052] In view of this, an embodiment of the present disclosure provides a display panel, which substantially improves the problem of low grayscale color deviation of pixels caused by limitations and defects of related technologies by setting an undercut structure and planning its setting position.

[0053] Specifically, Figure 2 A simplified diagram of a display panel provided in an embodiment of the present disclosure, such as Figure 2 As shown, the display panel includes a substrate 1 and a plurality of light-emitting devices 2 disposed on the substrate 1. The light-emitting device 2 includes a first electrode 21, a second electrode 22, a plurality of light-emitting units 23 disposed between the first electrode 21 and the second electrode 22, and a charge separation generating unit 24 disposed between adjacent light-emitting units 23. The first electrode 21 is closer to the substrate 1 than the second electrode 22; one of the first electrode 21 and the second electrode 22 is an anode and the other is a cathode; for example, the first electrode 21 is an anode and the second electrode 22 is a cathode. Under the action of an electric field, the charge separation generating unit 24 generates electrons and holes and separates them, wherein the electrons move to the light-emitting unit 23 close to the anode to perform composite light emission in the light-emitting unit 23; similarly, the holes move to the light-emitting unit 23 close to the cathode to perform composite light emission in the light-emitting unit 23. The plurality of light-emitting units 23 each independently emit light of the same or different colors. For example, if the light-emitting layers in the plurality of light-emitting units 23 are the same, light of the same color is emitted; if the light-emitting layers in the plurality of light-emitting units 23 are different, light of different colors is emitted.

[0054] For example, Figure 7 As shown, the charge separation generating unit 24 includes a first charge separation generating layer N-CGL generating electrons and a second charge separation generating layer P-CGL generating holes; wherein the first charge separation generating layer N-CGL is closer to the anode of the light emitting device 2 than the second charge separation generating layer P-CGL. The material of the first charge separation generating layer N-CGL is an N-type doped charge generating material, and the material of the second charge separation generating layer P-CGL is a P-type doped charge generating material.

[0055] Figure 3A schematic diagram of the structure of a display panel in Example 1 provided in an embodiment of the present disclosure, such as Figure 3 As shown, the multiple light-emitting devices 2 include a first light-emitting device 201, a second light-emitting device 202 and a third light-emitting device 203; the display panel also includes a pixel defining layer PDL; the pixel defining layer PDL includes a first pixel opening 31 corresponding to the first light-emitting device 201, a second pixel opening 32 corresponding to the second light-emitting device 202, and a third pixel opening 33 corresponding to the third light-emitting device 203.

[0056] Figure 4 The structure diagram of the pixel defining layer provided in the embodiment of the present disclosure is as follows: Figure 4 As shown, the first pixel opening 31 includes a first opening portion 311 and a second opening portion 312 which are sequentially arranged along a direction away from the base substrate 1, and an opening size H1 of the first opening portion 311 is larger than an opening size H2 of the second opening portion 312; the second pixel opening 32 includes a third opening portion 321 and a fourth opening portion 322 which are sequentially arranged along a direction away from the base substrate 1, and an opening size H3 of the third opening portion 321 is larger than an opening size H4 of the fourth opening portion 322; the side wall of the third pixel opening 33 is a flat plane.

[0057] It should be noted that, in the light emitting device 2, except for the first electrode 21, each film layer is laid in a whole layer, and the part corresponding to the pixel opening is sunken; Figure 3 As shown, the first opening portion 311 and the second opening portion 312 are connected to form a first undercut structure, and the first undercut structure cuts off the charge separation generating unit 24 (for example, N-CGL and P-CGL) falling into the first pixel opening 31, that is, the charge separation generating unit 24 between the first light-emitting device 201 and the third light-emitting device 203 or the second light-emitting device 202 adjacent thereto is cut off; the third opening portion 321 and the fourth opening portion 322 are connected to form a second undercut structure, and the second undercut structure cuts off the charge separation generating unit 24 falling into the second pixel opening 32, that is, the charge separation generating unit 24 between the second light-emitting device 202 and the third light-emitting device 203 or the first light-emitting device 201 adjacent thereto is cut off, thereby preventing lateral crosstalk between adjacent light-emitting devices 2.

[0058] At the same time, in the embodiment of the present disclosure, only the inner sides of the first pixel opening 31 and the second pixel opening 32 are provided with corresponding undercut structures, and the side wall of the third pixel opening 33 is a flat plane. Figure 1aIn the case where a partition structure 04 is set between the sub-pixel openings 03, the present invention lengthens the distance between Leak1 and Leak2, that is, lengthens the leakage path, slows down the leakage speed, and improves the problem of efficiency attenuation differences of different light-emitting devices 2 caused by the leakage problem, that is, improves the efficiency attenuation consistency of different light-emitting devices 2, thereby improving the color deviation phenomenon and improving the low grayscale consistency performance of the product.

[0059] It should be noted that the relevant technology Figure 1a This disclosure Figure 3 The premise of the comparative analysis of the structure shown is that the arrangement and center position of each light emitting device 2 remain unchanged, the first aperture ratio of the first light emitting device 201 remains unchanged, the second aperture ratio of the second light emitting device 202 remains unchanged, and the first aperture ratio of the third light emitting device 203 remains unchanged. Therefore, on the basis of the above contents remaining unchanged, the shortest distance D1 between the first pixel opening 31 and the third pixel opening 33 is equal. On this basis, Figure 3 The distance between Leak1 and Leak2 is shown in Figure 2. Figure 1a As shown, the distance between Leak1 and Leak2 is longer, as shown in the following figure: Figure 1a As shown, a partition structure 04 is provided between the sub-pixel openings 03; in order to isolate the CGL layer, the pixel defining layer PDL between adjacent light-emitting devices 02 needs to have a certain size D1 (for example, the distance in the first direction X) for forming the partition structure 04. In practical applications, the size D1 of the pixel defining layer PDL required to form the partition structure 04 must be greater than the maximum distance of the shortest pixel defining layer PDL that can be set between two adjacent light-emitting devices 02. At this time, Leak2 is located at the center of the pixel defining layer PDL between adjacent light-emitting devices 02, close to the side of the light-emitting device 02, that is, the shortest distance from Leak2 to the side wall of the sub-pixel opening 03 is less than half of D1. The position of Leak1 is close to the side wall of the sub-pixel opening 03, so it can be equivalent to the distance between Leak1 and Leak2 being less than half of D1. As shown in FIG. Figure 3 As shown, the undercut structure is located inside the first pixel opening 31 (or the second pixel opening 32), Leak1 is located inside the third sub-pixel opening 33, and Leak2 is located inside the first sub-pixel opening 31. Therefore, it can be seen that the distance between Leak1 and Leak2 is greater than D1; or, it can be understood that Leak1 is approximately located on the side wall of the third sub-pixel opening 33, and Leak2 is approximately located on the side wall of the first sub-pixel opening 31, so it can be equivalent to that the distance between Leak1 and Leak2 is equal to D1. In any case, the distance between Leak1 and Leak2 is greater than Figure 1a The distance between Leak1 and Leak2 is shown.

[0060] In some embodiments, Figure 4 As shown, the first pixel opening 31 also includes a fifth opening portion 313 arranged on the side of the first opening portion 311 away from the second opening portion 312; the second pixel opening 32 also includes a sixth opening portion 323 arranged on the side of the third opening portion 321 away from the fourth opening portion 322; the centers of the first opening portion 311, the second opening portion 312 and the fifth opening portion 313 are collinear; the centers of the third opening portion 321, the fourth opening portion 322 and the sixth opening portion 323 are collinear; the opening size H5 of the fifth opening portion 313 is less than or equal to the opening size H2 of the second opening portion 312; the opening size H6 of the sixth opening portion 323 is less than or equal to the opening size H4 of the fourth opening portion 322.

[0061] Furthermore, if Figure 4 As shown, for the adjacent first pixel opening 31 and third pixel opening 33 , the shortest distance D2 from the sidewall of the second opening 312 to the sidewall of the third pixel opening 33 is greater than half of the shortest distance D1 from the fifth opening 313 to the sidewall of the third pixel opening 33 .

[0062] Figure 5 A schematic diagram of adjacent first pixel openings and second pixel openings provided in an embodiment of the present disclosure, such as Figure 5 As shown, for the adjacent first pixel opening 31 and second pixel opening 32 , the shortest distance D3 from the side wall of the second opening 312 to the side wall of the fourth opening 322 is greater than half of the shortest distance D1 from the side wall of the fifth opening 313 to the sixth opening 323 .

[0063] The distance between Leak1 and Leak2 is shown in the structure disclosed in this embodiment. Figure 1a As shown, the distance between Leak1 and Leak2 is longer, as shown in the following figure: Figure 1a As shown in , the distance between Leak1 and Leak2 is less than half of D1; Figure 4 and Figure 5 As shown, the distance D2 or D3 between Leak1 and Leak2 is greater than half of D1, or even approximately equal to D1.

[0064] In some embodiments, the colors of light emitted by the first light emitting device 201 , the second light emitting device 202 , and the third light emitting device 203 may be the same or different.

[0065] The first light emitting device 201 and the second light emitting device 202 may be the same or different. The same here mainly refers to various limiting conditions of each film layer, including size, shape and material.

[0066] Optionally, the first light emitting device 201 and the second light emitting device 202 are the same. This means that the display panel of the present disclosure only includes two types of light emitting devices 2, and the difference between the two types of light emitting devices 2 is that the aperture ratios of the corresponding pixel openings are different.

[0067] In the display panel corresponding to this embodiment, the light emitting devices 2 have fewer categories, which facilitates the process preparation and ensures the consistency of the light emitting devices 2.

[0068] In some embodiments, Figure 3 As shown, the third opening ratio of the third pixel opening 33 is greater than the first opening ratio of the first pixel opening 31 ; the third opening ratio of the third pixel opening 33 is greater than the second opening ratio of the second pixel opening 32 .

[0069] It should be noted that the aperture ratio of the sub-pixel opening 3 refers to the ratio of the light-emitting area of ​​the corresponding light-emitting device to the overall coverage area of ​​a pixel unit.

[0070] In the disclosed embodiment, the first light emitting device 201 belongs to the red sub-pixel R, the second light emitting device 202 belongs to the green sub-pixel G, and the third light emitting device 203 belongs to the blue sub-pixel B. Since the decay rate of blue light is faster than that of red light and green light, the third aperture ratio corresponding to the third light emitting device 203 is greater than the first aperture ratio and the second aperture ratio to balance the luminous intensity of the three colors of light.

[0071] In some embodiments, since the third light emitting device 203 is not provided with a corresponding undercut structure, the third light emitting device 203 has a larger layout space for the third pixel opening 33 than the first light emitting device 201 and the second light emitting device 202 .

[0072] Figure 6 A schematic diagram of the structure of a display panel in Example 2 provided in an embodiment of the present disclosure, such as Figure 6 As shown, compared Figure 3 The difference between the structures shown is that: Figure 3 On the basis of the third aperture ratio shown in FIG. 1 , the aperture ratio of the third pixel opening 33 is further improved. At this time, for the adjacent first pixel opening 31 and the third pixel opening 33, the shortest distance M1 from the side wall of the fifth opening 313 to the side wall of the third pixel opening 33 is less than D1; the shortest distance M2 from the side wall of the second opening 312 to the side wall of the third pixel opening 33 is less than D2. Similarly, for the adjacent second pixel opening 31 and the third pixel opening 33, the shortest distance from the side wall of the sixth opening 323 to the side wall of the third pixel opening 33 is less than D1; the shortest distance from the side wall of the fourth opening 322 to the side wall of the third pixel opening 33 is less than D2. It should be noted that the specific sizes of M1 and M2 can be adjusted according to the requirements of the pixel aperture ratio, the realization of the opening preparation process, etc., and the specific data are not limited.

[0073] like Figure 6 As shown, the ratio of the third opening ratio to the first opening ratio is between 1.5 and 2; the ratio of the third opening ratio to the second opening ratio is between 1.1 and 2.

[0074] Exemplarily, the ratio of the third aperture ratio to the first aperture ratio may be 2:1.

[0075] For example, the ratio of the third aperture ratio to the second aperture ratio may be 2:1.5. Alternatively, the ratio of the third aperture ratio to the second aperture ratio may be 2:1.

[0076] Under the premise of not affecting the stability of the film layer and the signal stability, this embodiment appropriately reduces the shortest distance D2 from the side wall of the second opening 312 to the side wall of the third pixel opening 33, thereby reasonably increasing the aperture ratio of the third pixel opening 33, and then increasing the light-emitting area of ​​the third light-emitting device 203, so that the light output efficiency of each light-emitting unit 23 in the third light-emitting device 203 is improved, and the problem of reduced light-emitting efficiency caused by leakage is further improved; in addition, since the light emitted by each light-emitting device 2 only emits monochromatic light after passing through the color filter layer 6, and at this time there will be a problem of inconsistent brightness level attenuation of light-emitting devices 2 of different colors, therefore, this embodiment can improve the light-emitting efficiency of the third light-emitting device 203 while also compensating in advance for the blue sub-pixel B whose light-emitting efficiency attenuates too quickly, to ensure that the attenuation degree of the light-emitting efficiency of sub-pixels of different colors is consistent, thereby improving color deviation and ensuring that the display screen of the display product is consistent at low grayscale.

[0077] In some embodiments, Figure 4 As shown, the first light emitting device 201, the second light emitting device 202 and the third light emitting device 203 all emit white light, that is, all three are white light emitting devices.

[0078] Exemplarily, the light-emitting device 2 provided in the embodiment of the present disclosure is a multi-layer tandem white light OLED light-emitting device 2 (Tandem WOLED device), which has the characteristics of high brightness, long life, narrow half-peak width (high color gamut), and low power consumption.

[0079] In some embodiments, the plurality of light emitting units 23 include at least a first light emitting unit 231 and a second light emitting unit 232 ; the light emitted by the first light emitting unit 231 is different from the light emitted by the second light emitting unit 232 .

[0080] The first light-emitting unit 231 may be a mixed light-emitting unit including multiple light-emitting layers; the second light-emitting unit 232 may be a single-color light-emitting unit including one light-emitting layer.

[0081] Optionally, Figure 7 A schematic diagram of a white light emitter provided in an embodiment of the present disclosure, such as Figure 7 As shown, the first light-emitting unit 231 is closer to the substrate 1 than the second light-emitting unit 232; the first light-emitting unit 231 includes a red light-emitting layer EML_R and a green light-emitting layer EML_G; the second light-emitting unit 232 includes a blue light-emitting layer EML_B. The red light-emitting layer EML_R emits red light, the green light-emitting layer EML_G emits green light, the first light-emitting unit 231 emits a mixture of red and green light, such as yellow light, the blue light-emitting layer EML_B emits blue light, and finally the light-emitting device 2 emits white light.

[0082] Exemplarily, the red light-emitting layer EML_R and the green light-emitting layer EML_G are stacked and in direct contact with each other, and the red light-emitting layer EML_R is closer to the base substrate 1 than the green light-emitting layer EML_G.

[0083] like Figure 7 As shown, the first light-emitting unit 231 includes other light-emitting functional layers in addition to the red light-emitting layer EML_R and the green light-emitting layer EML_G, such as a first hole injection layer HIL1, a first hole transport layer HTL1, and a first electron blocking layer EBL1, which are sequentially arranged on the side of the first electrode 21 away from the substrate 1, and a first electron injection layer EIL1, a first electron transport layer ETL1, and a first hole blocking layer HBL1, which are sequentially arranged on the side of the charge separation generating unit 24 close to the first electrode 21.

[0084] The holes generated by the first electrode 21 pass through the first hole injection layer HIL1, the first hole transport layer HTL1, and the first electron blocking layer EBL1 in sequence to enter the first light-emitting unit 231, and the electrons generated by the charge separation generating unit 24 pass through the first electron injection layer EIL1, the first electron transport layer ETL1, and the first hole blocking layer HBL1 in sequence to enter the first light-emitting unit 231. At this time, the holes and electrons in the first light-emitting unit 231 recombine to generate excitons, and emit light by radiative transition.

[0085] like Figure 7 As shown, the above-mentioned second light-emitting unit 232 includes other light-emitting functional layers in addition to the blue light-emitting layer EML_B, such as a second hole injection layer HIL2, a second hole transport layer HTL2, and a second electron blocking layer EBL2, which are sequentially arranged on the side of the charge separation generating unit 24 close to the second electrode 22, and a second electron injection layer EIL2, a second electron transport layer ETL2, and a second hole blocking layer HBL2, which are sequentially arranged on the side of the second electrode 22 close to the charge separation generating unit 24.

[0086] The holes generated by the charge separation generating unit 24 sequentially pass through the second hole injection layer HIL2, the second hole transport layer HTL2, and the second electron blocking layer EBL2 to enter the second light-emitting unit 232, and the electrons generated by the second electrode 22 sequentially pass through the second electron injection layer EIL2, the second electron transport layer ETL2, and the second hole blocking layer HBL2 to enter the second light-emitting unit 232. At this time, the holes and electrons in the second light-emitting unit 232 recombine to generate excitons, and emit light by radiative transition.

[0087] It should be noted that, in addition to this embodiment, the plurality of light-emitting units 23 may also include at least three stacked light-emitting units 23, such as a first light-emitting unit 231, a second light-emitting unit 232, and a third light-emitting unit (not shown in the figure), and a charge separation generating unit 24 is provided between adjacent light-emitting units 23. Exemplarily, the first light-emitting unit 231 includes a red light-emitting layer EML_R and a green light-emitting layer EML_G, the second light-emitting unit 232 includes a first blue light-emitting layer; and the third light-emitting unit includes a second blue light-emitting layer. Again exemplarily, the first light-emitting unit 231 includes a red light-emitting layer EML_R, the second light-emitting unit 232 includes a green light-emitting layer EML_G, and the third light-emitting unit includes a blue light-emitting layer EML_B.

[0088] In the embodiment of the present disclosure, the display panel includes a plurality of pixel units, each pixel unit includes a plurality of sub-pixels, and a sub-pixel includes a light-emitting device 2 and a color filter corresponding to the light-emitting device 2. Each light-emitting device 2 can emit light of the same color, such as white light. Different sub-pixels emit light of different colors, and the different sub-pixels include, for example, a first color sub-pixel, a second color sub-pixel, and a third color sub-pixel.

[0089] For ease of understanding, the embodiments of the present disclosure are described using the first color being red, the second color being green, and the third color being blue as an example, but this does not mean that the first color, the second color, and the third color are only the above three colors. They can be set according to actual conditions, that is, the first color is not limited to red, the second color is not limited to green, and the third color is not limited to blue.

[0090] The following description is made by taking an example where a pixel unit includes a red sub-pixel R, a green sub-pixel G and a blue sub-pixel B.

[0091] In some embodiments, Figure 8a A schematic diagram of a specific structure of a display panel provided in an embodiment of the present disclosure is shown in FIG. Figure 8aAs shown, the display panel further includes an encapsulation layer 5 disposed on the side of the light emitting device 2 facing away from the base substrate 1, and a color filter layer 6 disposed on the side of the encapsulation layer 5 facing away from the base substrate 1. The color filter layer 6 includes a first color filter 61, a second color filter 62, and a third color filter 63; the first color filter 61 is disposed corresponding to the first light emitting device 201, the second color filter 62 is disposed corresponding to the second light emitting device 202, and the third color filter 63 is disposed corresponding to the third light emitting device 203; the first color filter 61 transmits red light, the second color filter 62 transmits green light, and the third color filter 63 transmits blue light.

[0092] That is, the red sub-pixel R includes a first color filter 61 and a first light-emitting device 201 , the green sub-pixel includes a second color filter 62 and a second light-emitting device 202 , and the blue sub-pixel B includes a third color filter 63 and a third light-emitting device 203 .

[0093] Figure 8b for Figure 8a A simple diagram from a bird's-eye view. Figure 8a for Figure 8b The cross-sectional view in the A-A' direction. Figure 8b As shown, any two red sub-pixels R are arranged at intervals; any two green sub-pixels G are arranged at intervals; and any two blue sub-pixels B are arranged at intervals. Exemplarily, a red sub-pixel R and a green sub-pixel G are arranged between any two blue sub-pixels B, a red sub-pixel R and a blue sub-pixel B are arranged between any two green sub-pixels G, and a green sub-pixel G and a blue sub-pixel B are arranged between any two red sub-pixels R.

[0094] Alternatively, if Figure 8b As shown, the outline shape of the orthographic projection of the first color filter 61 , the second color filter 62 and the third color filter 63 on the base substrate 1 is a hexagon.

[0095] Alternatively, if Figure 8bAs shown, the contour shape of the orthographic projection of the third color filter 63 on the substrate 1 is a regular hexagon, and the contour shape of the orthographic projection of the first color filter 61 and the second color filter 62 on the substrate 1 is an irregular hexagon, which is manifested in that at least some of the side lengths are different. Two adjacent first color filters 61 and second color filters 62 are symmetrically arranged with their contact edges as the symmetry axis. Taking a third color filter 63 as an example, the third color filter 63 is surrounded by a plurality of first color filters 61 and a plurality of second color filters 62, for example, the third color filter 63 is surrounded by three first color filters 61 and three second color filters 62, and the first color filters 61 and the second color filters 62 are alternately arranged along the direction surrounding the third color filter 63. The length of the contact edge between the first color filter 61 and the third color filter 63 is the first side length; the length of the contact edge between the second color filter 61 and the third color filter 63 is the second side length; the length of the contact edge between two adjacent first color filters 61 and second color filters 62 is the third side length; the first side length is equal to the second side length, and the third side length is less than the first side length.

[0096] Further, for any first color filter 61, the lengths of the two sides disposed opposite to each other are different, one is the first side length, and the other is the third side length. For any second color filter 62, the lengths of the two sides disposed opposite to each other are different, one is the second side length, and the other is the third side length. By arranging the first color filter 61, the second color filter 62, and the third color filter 63 in this arrangement, the densest arrangement of blue sub-pixels can be achieved, which is beneficial to improving PPI.

[0097] In some embodiments, Figure 8a As shown, the first pixel opening 31 corresponding to the red sub-pixel R has a first bottom cut structure capable of isolating the charge separation generating unit 24; the second pixel opening 32 corresponding to the green sub-pixel G has a second bottom cut structure capable of isolating the charge separation generating unit 24; the side wall of the third pixel opening 33 corresponding to the blue sub-pixel B is a flat surface.

[0098] compared to Figure 1aIn the case where a partition structure 04 is set between the sub-pixel openings 03, this embodiment lengthens the distance between Leak1 and Leak2 (see the above description for details); at low grayscale, the extension of the leakage path will reduce the leakage field strength at Leak2 (which can be equivalent to a parallel plate capacitor). It should be noted that at low grayscale, the blue light turns on early, thereby reducing the blue light luminous intensity, thereby reducing the leakage light (blue light) intensity between the red sub-pixel R (or green sub-pixel G) and the blue sub-pixel B, improving the color deviation problem caused by the early lighting of the blue light of the blue light-emitting layer EML_B at low grayscale due to leakage, thereby improving the low grayscale consistency performance of the product. It should be noted that even though there is still blue light leakage due to premature lighting of the blue light-emitting layer EML_B under low grayscale at the distorted position Leak2 disclosed in the present invention, since the first color filter 61 in the red sub-pixel R only transmits red light, the leaked blue light is absorbed and does not affect the luminescence of the red sub-pixel R; similarly, the second color filter 62 in the green sub-pixel G only transmits green light, so the leaked blue light is absorbed and does not affect the luminescence of the red sub-pixel R.

[0099] Fig. 9 Schematic diagram of the luminous efficiency of the red sub-pixel, the green sub-pixel and the blue sub-pixel under different current densities provided by the embodiment of the present disclosure, such as Fig. 9 As shown, the horizontal axis represents the current density and the vertical axis represents the luminous efficiency. Compared with the blue sub-pixel B' before optimization, the luminous efficiency of the optimized blue sub-pixel B in the present disclosure is significantly improved.

[0100] In some embodiments, Figure 8a As shown, the orthographic projection of the first color filter 61 on the base substrate 1 covers the orthographic projection of the second opening 312 on the base substrate 1 ; the orthographic projection of the second color filter 62 on the base substrate 1 covers the orthographic projection of the fourth opening 322 on the base substrate 1 .

[0101] Alternatively, if Figure 8a As shown, the center of the first color filter 61 and the center of the first pixel opening 31 are connected to form a straight line L1.

[0102] Alternatively, if Figure 8a As shown, the center of the second color filter 62 and the center of the second pixel opening 32 are connected to form a straight line L2.

[0103] Alternatively, if Figure 8a As shown, the center of the third color filter 63 and the center of the third pixel opening 33 are connected to form a straight line L3.

[0104] Optionally, the orthographic projection of the second opening 312 on the base substrate 1 and the orthographic projection of the fourth opening 322 on the base substrate 1 do not overlap with the orthographic projection of the third color filter 63 on the base substrate 1 .

[0105] In some embodiments, Figure 8a As shown, the orthographic projection of the first color filter 61 on the base substrate 1 covers the orthographic projection of the first opening 311 on the base substrate 1 ; the orthographic projection of the second color filter 62 on the base substrate 1 covers the orthographic projection of the third opening 321 on the base substrate 1 .

[0106] Optionally, the orthographic projection of the first opening 311 on the base substrate 1 and the orthographic projection of the third opening 321 on the base substrate 1 do not overlap with the orthographic projection of the third color filter 63 on the base substrate 1 .

[0107] In some embodiments, Fig.10 An enlarged view of the undercut structure provided in the embodiment of the present disclosure, such as Fig.10 As shown, the side wall 4021 of the first opening portion 311 and the side wall 4022 of the second opening portion 312 are connected to a first surface 4023 parallel to the plane where the base substrate 1 is located; the surface where the side wall 4022 is located is perpendicular to the first surface 4023; the surface where the side wall 4021 is located is inclined relative to the thickness direction Y of the display panel, and the dihedral angle formed by the surface where the side wall 4021 is located and the first surface 4023 is an acute angle.

[0108] Fig.10 This is only an example of an undercut structure of the present disclosure. Of course, the present disclosure is not limited to this type. For example, it can also be as follows Fig.11 The bottom cut structure similar to the inverted "bowl" type shown can be used as long as it can isolate the corresponding charge separation generating unit 24. The specific shape can be adjusted according to the actual process, and the present disclosure does not make specific limitations on this.

[0109] In some embodiments, Fig.10 As shown, the ratio of the maximum opening size H1 of the first opening 311 to the maximum opening size H2 of the second opening 312 is between 1.1 and 1.4. The ratio of the maximum opening size H3 of the third opening 321 to the maximum opening size H4 of the fourth opening 322 is between 1.1 and 1.4.

[0110] Optionally, the ratio of the maximum opening size H1 of the first opening 311 to the maximum opening size H2 of the second opening 312 may be 1.1, 1.2, 1.3 or 1.4. Optionally, the ratio of the maximum opening size H3 of the third opening 321 to the maximum opening size H4 of the fourth opening 322 may be 1.1, 1.2, 1.3 or 1.4.

[0111] In some embodiments, Fig.10 As shown, the vertical height of the sidewall forming the first opening 311 (i.e., the dimension in the Y direction) is between 30nm and 80nm; the concave depth of the first opening 311 compared to the second opening 312 (i.e., the concave dimension in the X direction) is between 30nm and 80nm. The sidewall forming the second opening 312 is between 5nm and 30nm.

[0112] In some embodiments, Fig.10 As shown, the outer contour of the orthographic projection of the maximum opening size V1 of the second opening portion on the base substrate 1 surrounds the outer contour of the orthographic projection of the corresponding sub-pixel opening 3 on the base substrate 1 .

[0113] Optionally, the center of the first opening V1 , the center of the second opening V2 , and the center of the corresponding sub-pixel opening 3 are connected to form a straight line.

[0114] In some embodiments, the substrate 1 provided in the embodiment of the present disclosure is a silicon substrate. The display panel provided in the embodiment of the present disclosure is a display panel of a silicon-based Tandem WOLED device.

[0115] In some embodiments, the material of the pixel defining layer PDL is an inorganic material, for example, selected from silicon oxide, silicon nitride, or a combination thereof.

[0116] In some embodiments, the pixel defining layer PDL is a one-layer structure or a multi-layer structure. Optionally, the pixel defining layer PDL is a three-layer structure; the thickness of the first layer of the pixel defining layer PDL is between 5nm and 30nm; the thickness of the second layer of the pixel defining layer PDL is between 30nm and 80nm; the thickness of the first layer of the pixel defining layer PDL is between 5nm and 30nm.

[0117] The disclosed embodiments optimize the pixel design of the display area, such as optimizing the position of the undercut structure and the third aperture ratio of the third light-emitting device 203, to improve the color cast problem caused by the inconsistent increase in luminous efficiency of the red sub-pixel R, the green sub-pixel G, and the blue sub-pixel B at low grayscales due to leakage, thereby improving the uniformity of the display product of the silicon-based tandem WOLED device at low grayscales (such as ultra-low grayscales of 0 to 10 grayscales), thereby improving the user experience.

[0118] In addition, the embodiment of the present disclosure further provides a display device, which includes the display substrate of any one of the above embodiments. The display device can be, for example, a mobile phone, a tablet computer, a television, a monitor, a laptop computer, a digital photo frame, a vehicle-mounted device, or any other product with a display function. Other essential components of the display device should be understood by those of ordinary skill in the art, and will not be described in detail here, nor should they be used as a limitation to the present disclosure.

[0119] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present disclosure, but the present disclosure is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and substance of the present disclosure, and these modifications and improvements are also considered to be within the scope of protection of the present disclosure.

Claims

1. A display panel, characterized in that: The invention comprises a substrate and a plurality of light-emitting devices arranged on the substrate; the light-emitting devices comprise a plurality of light-emitting units and a charge separation generating unit arranged between adjacent light-emitting units; the plurality of light-emitting devices comprise a first light-emitting device, a second light-emitting device and a third light-emitting device; The display panel further includes a pixel defining layer; the pixel defining layer includes a first pixel opening corresponding to the first light emitting device, a second pixel opening corresponding to the second light emitting device, and a third pixel opening corresponding to the third light emitting device; The first pixel opening comprises a first opening portion and a second opening portion which are sequentially arranged in a direction away from the base substrate, and the opening size of the first opening portion is larger than the opening size of the second opening portion; The second pixel opening comprises a third opening portion and a fourth opening portion which are sequentially arranged in a direction away from the base substrate, and the opening size of the third opening portion is larger than the opening size of the fourth opening portion; The side wall of the third pixel opening is a flat surface.

2. The display panel according to claim 1, characterized in that: The first pixel opening further includes a fifth opening portion disposed on a side of the first opening portion away from the second opening portion; the second pixel opening further includes a sixth opening portion disposed on a side of the third opening portion away from the fourth opening portion; the centers of the first opening portion, the second opening portion and the fifth opening portion are collinear; the centers of the third opening portion, the fourth opening portion and the sixth opening portion are collinear; The opening size of the fifth opening is smaller than or equal to the opening size of the second opening; the opening size of the sixth opening is smaller than or equal to the opening size of the fourth opening.

3. The display panel according to claim 2, characterized in that: For the adjacent first pixel opening and the third pixel opening, the shortest distance from the side wall of the second opening to the side wall of the third pixel opening is greater than half of the shortest distance from the fifth opening to the side wall of the third pixel opening; For the adjacent first pixel opening and the second pixel opening, the shortest distance from the side wall of the second opening to the side wall of the fourth opening is greater than half of the shortest distance from the side wall of the fifth opening to the side wall of the sixth opening.

4. The display panel according to claim 1, characterized in that: The third opening ratio of the third pixel opening is greater than the first opening ratio of the first pixel opening; the third opening ratio of the third pixel opening is greater than the second opening ratio of the second pixel opening.

5. The display panel according to claim 4, characterized in that: The ratio of the third aperture ratio to the first aperture ratio is between 1.1 and 2; the ratio of the third aperture ratio to the second aperture ratio is between 1.1 and 2.

6. The display panel according to claim 1, characterized in that: The first light emitting device, the second light emitting device and the third light emitting device all emit white light.

7. The display panel according to claim 6, characterized in that: The plurality of light emitting units at least include a first light emitting unit and a second light emitting unit, wherein the first light emitting unit is closer to the base substrate than the second light emitting unit; The first light-emitting unit includes a red light-emitting layer and a green light-emitting layer; the second light-emitting unit includes a blue light-emitting layer.

8. The display panel according to any one of claims 1 to 7, characterized in that: The first light emitting device and the second light emitting device are identical.

9. The display panel according to any one of claims 1 to 7, characterized in that: The display panel further comprises a color filter layer disposed on a side of the plurality of light-emitting devices away from the base substrate, the color filter layer comprising a first color filter, a second color filter and a third color filter; the first color filter is disposed corresponding to the first light-emitting device, the second color filter is disposed corresponding to the second light-emitting device, and the third color filter is disposed corresponding to the third light-emitting device; The first color filter transmits red light, the second color filter transmits green light, and the third color filter transmits blue light.

10. The display panel according to claim 9, characterized in that: The contour shape of the orthographic projection of the third color filter on the base substrate is a regular hexagon; the contour shapes of the orthographic projections of the first color filter and the second color filter on the base substrate are irregular hexagons, and the irregular hexagons have at least two sides of different lengths; Two adjacent first color filters and second color filters are symmetrically arranged with their contacting edges as symmetry axes; For any of the third color filters, a plurality of the first color filters and a plurality of the second color filters are arranged around it, and the first color filters and the second color filters are alternately arranged along a direction surrounding the third color filter; The length of the contact edge between the first color filter and the third color filter is the first side length; the length of the contact edge between the second color filter and the third color filter is the second side length; the length of the contact edge between two adjacent first color filters and the second color filter is the third side length; the first side length is equal to the second side length, and the third side length is less than the first side length.

11. The display panel according to claim 10, characterized in that: For any of the first color filters, one of the lengths of two sides disposed opposite to each other is the first side length, and the other is the third side length; For any second color filter, one of the lengths of two sides disposed opposite to each other is the second side length, and the other is the third side length.

12. The display panel according to claim 9, characterized in that: The orthographic projection of the first color filter on the base substrate covers the orthographic projection of the second opening on the base substrate; The orthographic projection of the second color filter on the base substrate covers the orthographic projection of the fourth opening on the base substrate.

13. The display panel according to any one of claims 1 to 7, characterized in that: The ratio of the maximum opening size of the first opening portion to the maximum opening size of the second opening portion is in a range of 1.1 to 1.

4.

14. The display panel according to any one of claims 1 to 7, characterized in that: The material of the substrate includes silicon.

15. A display device, characterized in that: The invention comprises the display panel according to any one of claims 1 to 14.

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