Display panel, preparation method thereof and display device

Abstract

The display panel comprises a substrate, an isolation structure and a plurality of light emitting devices on the substrate. The isolation structure encloses a plurality of isolated openings. The light emitting devices correspond to the isolated openings. The light emitting devices comprise, in sequence from bottom to top, a cathode, a light emitting functional layer and an anode on the substrate. The light emitting functional layer and the anode of the light emitting device are at least partially located in the corresponding isolated opening. The light emitting functional layer comprises at least one functional group. The functional group comprises, in sequence from the cathode to the anode, a first functional layer, a light emitting layer and a second functional layer. The optical thickness of the light emitting layer to the cathode is N times of 1 / 4 of the light emitting wavelength of the light emitting device, and N is a positive integer not less than 2. This scheme can ensure the light emitting efficiency of the light emitting device and reduce the risk of electric leakage at the edge position of the light emitting device.

Description

Technical Field

[0001] This disclosure relates to the field of display technology, specifically to a display panel and its manufacturing method, and a display device. Background Technology

[0002] Organic light-emitting diodes (OLEDs) are organic thin-film electroluminescent devices. They have attracted great attention and are widely used in electronic display products due to their advantages such as simple fabrication process, low cost, low power consumption, high brightness, wide viewing angle, high contrast and flexible display capability. The structure of this electronic display product can be found in the relevant descriptions in patents CN118251982A, 202410864269.8, PCT / CN2024 / 098407, PCT / CN2024 / 102783, PCT / CN2024 / 098217, PCT / CN2024 / 099419, PCT / CN2024 / 099072, CN117979755A, CN117998900A, CN117062489A, CN117580403A, CN116583155A, CN116669477A, ​​CN117396039A, CN116669480A, CN116600606A, and CN117500332A, and will not be repeated here.

[0003] However, current electronic display products are limited by their structural design, making it difficult to further improve display quality while ensuring a high pixel density (PPI). Summary of the Invention

[0004] This disclosure provides a display panel comprising a substrate, an isolation structure, and a plurality of light-emitting devices located on the substrate. The isolation structure encloses a plurality of isolation openings, with each light-emitting device corresponding to one of the openings. Each light-emitting device includes a cathode, a light-emitting functional layer, and an anode sequentially stacked on the substrate. The light-emitting functional layer and the anode of each light-emitting device are at least partially located within their respective isolation openings. The light-emitting functional layer includes at least one functional group, comprising a first functional layer, a light-emitting layer, and a second functional layer sequentially arranged from the cathode to the anode. The optical thickness of the light-emitting layer to the cathode is N times one-quarter of the emission wavelength of the light-emitting device, where N is a positive integer not less than 2.

[0005] By using an isolation structure, light-emitting devices can be fabricated in batches, allowing for full-area evaporation during the fabrication of the light-emitting device's film layers. This eliminates the need to consider the alignment accuracy of the film layers formed by each evaporation process after formation, which can significantly reduce the gap between individual light-emitting devices and increase their pixel density (PPI). However, in this process, the edges of the light-emitting functional layers of the light-emitting devices may come into contact with the sidewalls of the isolation structure, potentially causing leakage current (including lateral and longitudinal leakage). In the above scheme, the light-emitting device is inverted, that is, the cathode of the light-emitting device faces the substrate. Thus, the first functional layer is primarily an electron-conducting film, while the second functional layer is primarily a hole-conducting film. The conductivity of the electron-conducting film is lower than that of the hole-conducting film. Compared to an upright light-emitting device, this reduces the risk of lateral leakage. Furthermore, by adjusting the thickness of the first functional layer to ensure the spacing between the light-emitting layer and the cathode meets the aforementioned conditions, not only can the light-emitting layer be positioned at the standing wave position of the microcavity structure formed by the light-emitting device, increasing the light extraction efficiency, but the thickness of the first functional layer (primarily an electron-conducting film) can also be increased to further reduce the risk of longitudinal leakage at the edges of the light-emitting device. This reduces the power consumption of the display panel, increases the lifespan of the light-emitting device, and improves the visual effect of the displayed image (e.g., improving low-grayscale image quality).

[0006] In one specific embodiment of the first aspect of this disclosure, the anode comprises a high work function material and the cathode comprises a low work function material.

[0007] Optionally, the anode comprises indium tin oxide. In this way, the anode is a transparent electrode, thereby improving the light extraction efficiency of the side of the light-emitting device away from the substrate.

[0008] Optionally, the cathode comprises a metal. More optionally, the cathode comprises at least one of silver, magnesium, and aluminum. In this way, the cathode itself can increase the light extraction efficiency of the light-emitting device by increasing the thickness of the cathode to directly set it as a high-reflectivity electrode, and the sheet resistance during cathode driving can be reduced (due to increased thickness).

[0009] In one specific embodiment of the first aspect of this disclosure, the first functional layer includes electronic materials and the second functional layer includes hole materials.

[0010] Optionally, the first functional layer includes at least one of an electron injection layer and an electron transport layer.

[0011] Optionally, the second functional layer includes at least one of a hole injection layer and a hole transport layer.

[0012] In one specific embodiment of the first aspect of this disclosure, the light-emitting functional layer of the light-emitting device includes only one functional group, and the number of the first functional layer, the light-emitting layer and the second functional layer is one.

[0013] Optionally, the optical thickness from the light-emitting layer to the cathode is half the emission wavelength of the light-emitting device. In this way, while ensuring that the first functional layer containing electronic materials has a large thickness to reduce leakage current, the light-emitting layer is located at the standing wave position of the microcavity structure, thereby ensuring the light emission efficiency of the light-emitting device.

[0014] In one specific embodiment of the first aspect of this disclosure, the optical thickness of the surface of the light-emitting layer on the side away from the cathode from the anode is 1 / 4 of the emission wavelength of the light-emitting device. This maintains the microcavity structure of the light-emitting device, thereby ensuring its light emission efficiency.

[0015] In one specific embodiment of the first aspect of this disclosure, the light-emitting functional layer of the light-emitting device includes at least two functional groups, and the number of the first functional layer, the light-emitting layer, and the second functional layer are both at least two. Thus, the light-emitting device has at least two light-emitting layers, thereby achieving high light extraction efficiency to increase the brightness of the displayed image on the display panel. Furthermore, this design allows for more space to adjust the thickness of each film layer of the light-emitting device, ensuring that the first functional layer adjacent to the cathode has sufficient thickness to reduce leakage current.

[0016] Optionally, the optical thickness of the light-emitting layer in the functional group closest to the cathode is half the emission wavelength of the light-emitting device. When the light-emitting device has multiple functional groups, there is more space to adjust the thickness of each film layer of the light-emitting device. This ensures that the first functional layer adjacent to the cathode has sufficient thickness while also ensuring that the light-emitting layer is located at the standing wave position of the microcavity structure formed by the light-emitting device, thereby ensuring the light emission efficiency of the light-emitting device.

[0017] Optionally, the optical thickness between adjacent light-emitting layers is one-quarter of the emission wavelength of the light-emitting device. In this way, each light-emitting layer is located at the standing wave position of the microcavity structure, thereby ensuring the light emission efficiency of the light-emitting device.

[0018] Optionally, the thickness of the first functional layer in the functional group closest to the cathode is greater than the thickness of the first functional layer in other functional groups.

[0019] In one specific embodiment of the first aspect of this disclosure, the optical thickness of the light-emitting layer closest to the anode to the side of the anode away from the cathode is 1 / 4 of the emission wavelength of the light-emitting device.

[0020] In one specific embodiment of the first aspect of this disclosure, the light-emitting functional layer further includes a charge-generating layer located between adjacent functional groups.

[0021] In one specific embodiment of the first aspect of this disclosure, the isolation structure includes a support portion and a crown portion. The support portion is located between the substrate and the crown portion, and the orthographic projection of the surface of the support portion away from the substrate onto the substrate is located within the orthographic projection of the crown portion onto the substrate. Thus, the size of the crown portion is larger than the size of the upper portion of the support portion to ensure the isolating effect of the isolation structure on the film layer of the light-emitting device. Furthermore, this arrangement can limit the evaporation angle of the film layer of the light-emitting device during evaporation, thereby ensuring that the anode can overlap with the isolation structure while reducing the overlap area between the light-emitting functional layer and the isolation structure or avoiding overlap between the light-emitting functional layer and the isolation structure.

[0022] Optionally, the support is a conductive structure, with the edge of the anode overlapping the side surface of the support. In this way, the conductive support can connect the anodes of each light-emitting device in series to form a common electrode. Since the support is located between the light-emitting devices, it does not require light transmission and is not limited by thickness, thereby reducing the impedance of the common electrode and alleviating the voltage drop problem on each anode when driving the light-emitting devices.

[0023] Optionally, the orthographic projection of the light-emitting functional layer on the substrate lies within the orthographic projection of the anode on the substrate. This ensures that the light-emitting functional layer does not completely block the anode and the isolation structure, allowing the edge portion of the anode to overlap with the isolation structure.

[0024] In one specific embodiment of the first aspect of this disclosure, the orthographic projection of the support portion on the substrate lies within the orthographic projection of the crown portion on the substrate. Thus, the size of the crown portion is larger than the size of the support portion. In the evaporation deposition process for fabricating the film layer of a light-emitting device based on the isolation structure, the entry angle of the evaporation material can be limited based on the edge of the crown to control the extension range of the evaporation film layer below the crown, thereby controlling the position of the edge of the evaporation film layer. This ensures that the light-emitting functional layer avoids or minimizes overlap with the isolation structure, while maximizing the overlap between the anode and the isolation structure.

[0025] In one specific embodiment of the first aspect of this disclosure, in the edge region of the isolation opening, the thickness of the portion of each film layer of the light-emitting functional layer closer to the edge of the isolation opening is smaller.

[0026] Optionally, the first functional layer includes a first part and a second part, the second part surrounds the first part, the orthographic projection of the junction of the first part and the second part on the substrate coincides with the orthographic projection of the edge of the crown on the substrate, the orthographic projection of the second part on the substrate is located within the orthographic projection of the crown on the substrate, and the thickness of the second part gradually decreases from the junction of the second part and the first part to the edge of the second part away from the first part.

[0027] In one specific embodiment of the first aspect of this disclosure, the isolation opening includes a first side and a second side opposite to each other along a first direction, and a third side and a fourth side opposite to each other along a second direction. The first direction and the second direction intersect. At the first side and the second side, the edge of the first functional layer of the functional group adjacent to the cathode overlaps with the side surface of the support. At the third side and the fourth side, the edge of the first functional layer is spaced from the side surface of the support.

[0028] In another specific embodiment of the first aspect of this disclosure, the isolation opening includes a first side and a second side opposite to each other along a first direction, and a third side and a fourth side opposite to each other along a second direction. The first direction and the second direction intersect. At the first side, the second side, the third side, and the fourth side, the edges of the first functional layer of the functional group adjacent to the cathode overlap with the side surface of the support. The overlap area of ​​the first functional layer with the support at the first side and the second side is greater than the overlap area with the support at the third side and the fourth side.

[0029] In one specific embodiment of the first aspect of this disclosure, the distance between the first and second sides of the isolation opening is smaller than the distance between the third and fourth sides of the isolation opening. Thus, the first and second sides form the long side direction of the isolation opening. At the first and second sides, there is a larger connection area between the anode of the light-emitting device and the isolation structure, resulting in relatively low impedance. Therefore, during vapor deposition, the scanning direction of the vapor deposition is controlled to make it easier for the vapor-deposited material to be deposited at the first and second sides. However, this also makes it easier for the vapor-deposited film layer (light-emitting functional layer) to overlap with the support portion of the isolation structure at the first and second sides. That is, at the first and second sides, the leakage current is also greater when the light-emitting functional layer is connected to the support portion. By adopting the above-described solution of this disclosure, the leakage current occurring at the first and second sides can be avoided or reduced.

[0030] In one specific embodiment of the first aspect of this disclosure, the isolation structure further includes a bottom located between the support and the substrate, wherein the orthographic projection of the support on the substrate is located within the orthographic projection of the bottom on the substrate.

[0031] Optionally, the bottom is a conductive structure, and the anode overlaps with the portion of the bottom surface facing away from the substrate that is not covered by the support. Compared to the sidewalls of the support, the anode is more easily deposited on the surface area of ​​the bottom facing away from the substrate, thereby reducing the impedance at the connection between the anode and the isolation structure.

[0032] Optionally, the orthographic projection of the bottom on the substrate lies within the orthographic projection of the crown on the substrate.

[0033] Optionally, the materials of the bottom, support and crown are molybdenum, aluminum and titanium or titanium, aluminum and titanium, respectively.

[0034] In one specific embodiment of the first aspect of this disclosure, the isolation opening includes a first side and a second side opposite to each other along a first direction, and a third side and a fourth side opposite to each other along a second direction. The first direction and the second direction intersect. At the first side and the second side, the edge of the first functional layer of the functional group adjacent to the cathode overlaps with the bottom surface away from the substrate. At the third side and the fourth side, the edge of the first functional layer is spaced from the bottom surface away from the substrate.

[0035] In another specific embodiment of the first aspect of this disclosure, the isolation opening includes a first side and a second side opposite to each other along a first direction, and a third side and a fourth side opposite to each other along a second direction. The first direction and the second direction intersect. At the first side, the second side, the third side, and the fourth side, the edges of the first functional layer included in the functional group adjacent to the cathode overlap with the bottom surface away from the substrate. The overlap area of ​​the first functional layer with the bottom surface away from the substrate at the first side and the second side is greater than the overlap area with the bottom surface away from the substrate at the third side and the fourth side.

[0036] In one specific embodiment of the first aspect of this disclosure, the first direction and the second direction are perpendicular.

[0037] In one specific embodiment of the first aspect of this disclosure, when the isolation structure has a bottom, the distance between the first and second sides of the isolation opening is smaller than the distance between the third and fourth sides of the isolation opening. Thus, the first and second sides are along the long side direction of the isolation opening. At the first and second sides, there is a larger connection area between the anode of the light-emitting device and the isolation structure, resulting in relatively low impedance. Therefore, during vapor deposition, the scanning direction of the vapor deposition is controlled to make it easier for the vapor-deposited material to be deposited at the first and second sides. However, this also makes it easier for the vapor-deposited film layer (light-emitting functional layer) to overlap with the bottom of the isolation structure at the first and second sides. That is, at the first and second sides, the light-emitting functional layer, when connected to the bottom, will also result in a larger leakage current. By adopting the above-described solution of this disclosure, the leakage current occurring at the first and second sides can be avoided or reduced.

[0038] In one specific embodiment of the first aspect of this disclosure, the display panel may further include a pixel defining layer, the pixel defining layer being located on a substrate and including pixel openings corresponding to the isolation openings, the pixel openings communicating with the corresponding isolation openings, and the light-emitting functional layer of the light-emitting device filling the pixel openings and extending to the surface of the pixel defining layer away from the substrate.

[0039] Optionally, the pixel defining layer includes an inorganic film layer. Inorganic films are denser and have higher insulation properties. In processes where light-emitting devices are fabricated based on isolation structures, the pixel defining layer does not need to be very thick to accommodate the light-emitting devices, thus facilitating the thinner and lighter design of the display panel. Furthermore, the pixel defining layer including the inorganic film layer can have higher bonding strength with the isolation structure and cathode, reducing the risk of the isolation structure and cathode detaching. Additionally, the high density of the inorganic film layer can more effectively block the intrusion of water, oxygen, etc., thereby improving the encapsulation effect of the display panel.

[0040] Optionally, the orthographic projection of the pixel opening on the substrate is located within the orthographic projection of the isolation opening on the substrate.

[0041] Optionally, the orthographic projection of the pixel opening onto the substrate is located within the orthographic projection of the cathode onto the substrate, and the edge portion of the cathode is located between the pixel defining layer and the substrate.

[0042] Optionally, the pixel defining layer is located between the isolation structure and the substrate.

[0043] In one specific embodiment of the first aspect of this disclosure, the display panel may further include a first encapsulation layer. The first encapsulation layer is located on the side of the light-emitting device away from the substrate and includes a plurality of encapsulation units, each of which covers an isolation opening corresponding to the light-emitting device. During the batch fabrication of the light-emitting device based on the isolation structure, the encapsulation units are fabricated synchronously with the light-emitting devices in batches, thereby protecting the already fabricated light-emitting devices during the process of fabricating the next batch of light-emitting devices (in which etching is involved).

[0044] Optionally, the packaging unit extends to the side of the isolation structure away from the substrate, and the portion of the packaging unit located on the side of the isolation structure away from the substrate is a suspended portion, which is spaced apart from the isolation structure.

[0045] Optionally, the first encapsulation layer includes an inorganic film layer.

[0046] Optionally, the display panel further includes a second encapsulation layer and a third encapsulation layer, which cover the first encapsulation layer and the isolation structure, with the second encapsulation layer located between the first encapsulation layer and the third encapsulation layer.

[0047] Optionally, the second encapsulation layer includes an organic film layer, and the third encapsulation layer includes an inorganic film layer.

[0048] A second aspect of this disclosure provides a display panel including a substrate, an isolation structure on the substrate, and a plurality of light-emitting devices. The isolation structure encloses a plurality of isolation openings, with each light-emitting device corresponding to one of the openings. Each light-emitting device includes a cathode, a light-emitting functional layer, and an anode sequentially stacked on the substrate, with the light-emitting functional layer and anode at least partially located within their respective isolation openings. The light-emitting functional layer includes at least one functional group, comprising a first functional layer, a light-emitting layer, and a second functional layer arranged sequentially from the cathode to the anode. The optical thickness from the light-emitting layer closest to the cathode to the cathode is greater than the optical thickness from the light-emitting layer closest to the anode to the anode. Thus, the light-emitting device is inverted, i.e., the cathode of the light-emitting device faces the substrate. In this configuration, the first functional layer is primarily an electron-conducting film, while the second functional layer is primarily a hole-conducting film. Since the conductivity of the electron-conducting film is less than that of the hole-conducting film, the risk of lateral leakage can be reduced compared to a normally positioned light-emitting device. Furthermore, by increasing the thickness of the first functional layer (primarily an electron-conducting film), the risk of longitudinal leakage at the edges of the light-emitting device is further reduced. This can reduce the power consumption of the display panel, increase the lifespan of the light-emitting devices, and improve the visual effect of the displayed images (such as improving low grayscale image quality).

[0049] This disclosure provides a method for fabricating a display panel, the method comprising: providing a substrate and forming a plurality of spaced-apart cathodes on the substrate; forming an isolation structure, wherein the isolation structure encloses a plurality of isolation openings, the isolation openings corresponding to the cathodes respectively; depositing a light-emitting material thin film and a conductive material thin film, the light-emitting material thin film and the conductive material thin film covering the isolation structure and the isolation openings, wherein portions of the light-emitting material thin film and the conductive material thin film located in the isolation openings can respectively form a light-emitting functional layer and an anode, the cathodes, the light-emitting functional layer and the anode stacked on top of each other constituting a light-emitting device; depositing an encapsulation material film layer to cover the light-emitting material thin film and the conductive material thin film; forming a photoresist layer on the encapsulation material film layer, and performing a patterning process on the photoresist layer to form a photoresist pattern, the photoresist pattern covering a portion of the isolation openings; etching the encapsulation material film layer, the light-emitting material thin film and the conductive material thin film based on the photoresist pattern, wherein the remaining portion of the encapsulation material film layer forms an encapsulation unit, and the portions of the light-emitting material thin film and the conductive material thin film not covered by the encapsulation unit are etched; repeating the above process to form a light-emitting device and an encapsulation unit at the isolation openings where no light-emitting device is formed. In the display panel obtained based on the above-described fabrication method, the light-emitting device is inverted, meaning the cathode of the light-emitting device faces the substrate. Thus, the first functional layer is primarily an electron-conducting film, while the second functional layer is primarily a hole-conducting film. The conductivity of the electron-conducting film is lower than that of the hole-conducting film, which reduces the risk of lateral leakage compared to a front-mounted light-emitting device. Furthermore, by adjusting the thickness of the first functional layer to ensure the spacing between the light-emitting layer and the cathode meets the aforementioned conditions, not only can the light-emitting layer be positioned at the standing wave position of the microcavity structure formed by the light-emitting device, increasing the light extraction efficiency, but the thickness of the first functional layer (primarily an electron-conducting film) can also be increased to further reduce the risk of longitudinal leakage at the edges of the light-emitting device. This reduces the power consumption of the display panel, increases the lifespan of the light-emitting device, and improves the visual effect of the displayed image (e.g., improving low-grayscale image quality).

[0050] The fourth aspect of this disclosure is a display device, which includes the display panel described in the first or second aspect above, or a display panel obtained by the preparation method described in the third aspect above. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the planar structure of a display panel provided in one embodiment of the present disclosure.

[0052] Figure 2 for Figure 1 The image shows an enlarged view of area S1 of the display panel in one design.

[0053] Figure 3 for Figure 2The diagram shows a planar structural schematic of a sub-pixel of the display panel.

[0054] Figure 4A for Figure 2 The diagram shows a cross-sectional view of the display panel along M1-N1 in one design.

[0055] Figure 4B for Figure 4A An enlarged view of a portion of the structure of a certain area of ​​the display panel shown.

[0056] Figure 5A for Figure 2 The diagram shows a cross-sectional view of the display panel along M2-N2 in one design, which is consistent with... Figure 4A The corresponding display panel is shown.

[0057] Figure 5B for Figure 5A An enlarged view of a portion of the structure of a certain area of ​​the display panel shown.

[0058] Figure 6 This is a schematic diagram of the film layer stacking structure of the light-emitting device in a display panel according to an embodiment of the present disclosure.

[0059] Figure 7 This is a schematic diagram of the film layer stacking structure of the light-emitting device in another design of the display panel provided in one embodiment of the present disclosure.

[0060] Figure 8A for Figure 2 The diagram shows a cross-sectional view of the display panel along M1-N1 in another design.

[0061] Figure 8B for Figure 8A An enlarged view of a portion of the structure of a certain area of ​​the display panel shown.

[0062] Figure 9A for Figure 2 The diagram shown is a cross-sectional view of the display panel along M2-N2 under another design, which is consistent with... Figure 8A The corresponding display panel is shown.

[0063] Figure 9B for Figure 9A An enlarged view of a portion of the structure of a certain area of ​​the display panel shown.

[0064] Figure 10 for Figure 2 The diagram shows a cross-sectional view of the display panel along M1-N1 in another design.

[0065] Figure 11 This is a flowchart illustrating a method for manufacturing a display panel according to an embodiment of the present disclosure.

[0066] Figures 12A to 12H An embodiment of this disclosure provides a method for forming such Figure 4A The diagram shows a process diagram of one method for manufacturing a display panel.

[0067] Figure 13 This is a schematic diagram showing the positional relationship between a portion of a film layer in a display panel and the vapor deposition source during vapor deposition, according to an embodiment of this disclosure.

[0068] Explanation of reference numerals in the attached figures:

[0069] 10-Display panel; 11-Display area; 12-Border area;

[0070] 100 - Substrate; 200 - Light-emitting device; 210 - Cathode; 220 - Light-emitting functional layer; 220A - Functional group; 221 - First functional layer; 221A - First part; 221B - Second part; 222 - Light-emitting layer; 223 - Second functional layer; 224 - Charge generation layer; 230 - Anode; 300 - Isolation structure; 301 - Isolation opening; 302 - Pixel opening; 302a - First side; 302b - Second side; 302c - Third side; 302d - Fourth side; 310 - Support portion; 310a - First material layer; 320 - Crown portion; 320a - Second material layer; 330 - Pixel defining layer; 330a - Pixel defining material layer; 340 - Bottom;

[0071] 400 - Packaging structure; 410 - First packaging layer; 410a - Packaging material film layer; 411 - Packaging unit; 4111 - Suspension portion; 420 - Second packaging layer; 430 - Third packaging layer;

[0072] 500 - Photoresist pattern; 500a - Filler film. Detailed Implementation

[0073] The technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this specification, and not all embodiments. Based on the embodiments in this specification, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this specification.

[0074] In some scenarios, functional films in light-emitting devices are formed by vapor deposition. Each light-emitting device has multiple functional films, and the material composition of some functional films (such as the light-emitting layer) in light-emitting devices that emit different light is different. Therefore, when vapor deposition of these functional films using a mask (such as a fine mask), multiple alignments are required. To solve the positional offset problem caused by alignment accuracy errors, sufficient space (a safety margin related to alignment errors) needs to be reserved between different light-emitting devices to ensure that the actual light-emitting area of ​​the light-emitting device can have a certain overlap with the designed position (design area). This is equivalent to compressing the designed area of ​​the light-emitting area of ​​the light-emitting device, which not only limits the light-emitting area of ​​the light-emitting device, but also prevents the arrangement density of the light-emitting devices from being further increased, thus making it difficult to further improve the PPI (pixel density) of the display panel.

[0075] In the embodiments of this disclosure, by providing an isolation structure at the gap between the light-emitting devices, the functional film layers of adjacent light-emitting devices are separated. Thus, in the evaporation process of the functional film layers, only the entire display panel needs to be evaporated, without the need to individually prepare the functional film layer for each light-emitting device using a mask. This process does not require consideration of alignment accuracy during evaporation, thereby allowing the gaps between the light-emitting devices to be designed to be smaller, increasing the PPI (the principle of which can be found in the following...). Figures 12A to 12H (Related descriptions in the relevant embodiments).

[0076] It should be noted that, during the fabrication of light-emitting devices based on the aforementioned isolation structure, the inventors discovered through long-term research that the vapor-deposited film extends towards the bottom of the isolation structure (the principle can be found in [reference needed]). Figure 13 (As described in the relevant embodiments), this causes some of the vapor-deposited film layers (excluding the electrodes they include) of the light-emitting device to connect to the isolation structure. Thus, during the driving of the light-emitting device, current is directly conducted along these vapor-deposited film layers to the isolation structure (without being indirectly conducted to the isolation structure via the electrodes included in the light-emitting device, such as the cathode), resulting in lateral leakage current. Furthermore, at the edges of the vapor-deposited film layers, the thickness decreases, making them susceptible to voltage breakdown, resulting in longitudinal leakage current. This leakage current can lead to poor display performance at low grayscale levels and reduced lifespan of the light-emitting device.

[0077] At least one embodiment of this disclosure provides a display panel, a method for fabricating the same, and a display device, to at least solve the aforementioned technical problems. The display panel includes a substrate, an isolation structure, and a plurality of light-emitting devices located on the substrate. The isolation structure encloses a plurality of isolation openings, with the light-emitting devices corresponding to the isolation openings. Each light-emitting device includes a cathode, a light-emitting functional layer, and an anode sequentially stacked on the substrate. The light-emitting functional layer and the anode of the light-emitting device are at least partially located within the corresponding isolation openings. The light-emitting functional layer includes at least one functional group, which includes a first functional layer, a light-emitting layer, and a second functional layer arranged sequentially from the cathode to the anode. The optical thickness of the light-emitting layer to the cathode is N times 1 / 4 of the emission wavelength of the light-emitting device, where N is a positive integer not less than 2. The isolation structure allows for batch fabrication of the light-emitting devices, enabling full-area vapor deposition during the fabrication of the film layers. This eliminates the need to consider the alignment accuracy of the film layers formed by each vapor deposition process after formation, which can significantly reduce the gap between the light-emitting devices and increase the pixel density (PPI) of the light-emitting devices. In the aforementioned process, the edge of the light-emitting functional layer of the light-emitting device may come into contact with the sidewall of the isolation structure, potentially causing leakage current (including lateral and longitudinal leakage). In the above solution, the light-emitting device is inverted, i.e., the cathode of the light-emitting device faces the substrate. Thus, the first functional layer is primarily an electron-conducting film, while the second functional layer is primarily a hole-conducting film. The conductivity of the electron-conducting film is lower than that of the hole-conducting film, reducing the risk of lateral leakage compared to a front-mounted light-emitting device. Furthermore, by adjusting the thickness of the first functional layer to ensure the spacing between the light-emitting layer and the cathode meets the aforementioned conditions, not only can the light-emitting layer be positioned at the standing wave position of the microcavity structure formed by the light-emitting device, increasing the light extraction efficiency, but the thickness of the first functional layer (primarily an electron-conducting film) can also be increased to further reduce the risk of longitudinal leakage at the edge of the light-emitting device. This reduces the power consumption of the display panel, increases the lifespan of the light-emitting device, and improves the visual effect of the displayed image (e.g., improving low-grayscale image quality).

[0078] The structure of a display panel according to at least one embodiment of the present disclosure will now be described in detail with reference to the accompanying drawings. Furthermore, in these drawings, a spatial rectangular coordinate system is established with the substrate as a reference to more intuitively present the positional relationships of the relevant structures in the display panel. In this spatial rectangular coordinate system, the X-axis and Y-axis are parallel to the plane of the substrate, and the Z-axis is perpendicular to the plane of the substrate.

[0079] like Figures 1 to 6As shown, the planar area of ​​the display panel 10 can be divided into a display area 11 and a border area 12 surrounding the display area 11. Sub-pixels (also called sub-pixels, etc.) can be arranged in the display area 11, such as P1, P2, P3 sub-pixels. The physical structure of the sub-pixel can be the light-emitting device in the following embodiment. Adjacent sub-pixels with different emitted light colors constitute a pixel (also called a pixel unit, large pixel, etc.). The arrangement density of the pixel in the display area 11 represents the pixel density PPI.

[0080] The physical structure of the display panel 10 may include a substrate 100, an isolation structure 300 located on the substrate 100, and a plurality of light-emitting devices 200. The isolation structure 300 encloses a plurality of isolation openings 301, and the light-emitting devices 200 correspond to the isolation openings 301. The physical light-emitting structure of the P1, P2, and P3 sub-pixels is the light-emitting device 200. Thus, the light-emitting devices 200 can be classified as light-emitting devices that emit different colors of light.

[0081] The light-emitting device 200 includes a cathode 210, a light-emitting functional layer 220, and an anode 230 stacked sequentially on a substrate 100. The light-emitting functional layer 220 and the anode 230 of the light-emitting device 200 are located in corresponding isolation openings 301. That is, the light-emitting functional layer 220 and the anode 230 can be formed by vapor deposition. Specifically, after forming the isolation structure 300 with the isolation openings 301, vapor deposition is performed on the entire surface to form the light-emitting functional layer 220 and the anode 230 in each isolation opening 301 respectively.

[0082] The light-emitting functional layer 220 includes at least one functional group 220A. The functional group 220A includes a first functional layer 221, a light-emitting layer 222, and a second functional layer 223 arranged sequentially from the cathode 210 to the anode 230. The optical thickness of the light-emitting layer 222 to the cathode 210 is N times 1 / 4 of the emission wavelength of the light-emitting device 200. Figure 6 The middle is 1 / 2λ), N( Figure 6(2) is a positive integer not less than 2. In the embodiments of this disclosure, the light-emitting device 200 is configured to be inverted. Then, the first functional layer 221 is a film layer that mainly conducts electrons, and the second functional layer 223 is a film layer that mainly conducts holes. The conductivity of the film layer that conducts electrons is less than the conductivity of the film layer that conducts holes. Compared with the upright configuration of the light-emitting device 200, the bottom layer of the functional group 220A can be avoided from being a film layer used for conducting holes (the film layer where leakage mainly occurs), thereby reducing the risk of lateral leakage of the light-emitting device 200. In addition, by setting the thickness of the first functional layer 221, the spacing between the light-emitting layer 222 and the cathode 210 can be ensured to meet the above conditions. This not only allows the light-emitting layer 222 to be located at the standing wave position of the microcavity structure formed by the light-emitting device 200 to increase the light output of the light-emitting device 200, but also increases the thickness of the first functional layer 221 (which is mainly a film layer that conducts electrons) to further reduce the risk of longitudinal leakage at the edge position of the light-emitting device 200.

[0083] In the embodiments of this disclosure, "optical thickness" is the optical path length of light in the film layer, which is the product of the actual thickness of the film layer and its refractive index.

[0084] The microcavity structure is a structure in which the light emitted by the light-emitting device 200 can produce a microcavity effect. The microcavity effect is the resonance phenomenon that occurs between the cathode 210 and the anode 230 when the light emitted by the light-emitting layer 222 in the light-emitting device 200 is reflected repeatedly between the cathode 210 and the anode 230. The phase accumulation of multiple reflections enhances the intensity of light of a specific wavelength.

[0085] In at least one embodiment of this disclosure, the cathode 210 is an electrode comprising a low work function material, such as a metallic material; and the anode 230 is an electrode comprising a high work function material, such as a metal oxide material.

[0086] For example, the anode 230 comprises indium tin oxide. Thus, the anode 230 is a transparent electrode, thereby improving the light extraction efficiency of the side of the light-emitting device 200 away from the substrate 100.

[0087] For example, the cathode 210 may include at least one of silver, magnesium, and aluminum. In this way, the cathode 210 itself can increase the light extraction efficiency of the light-emitting device 200 by increasing the thickness of the cathode 210 to directly set it as a high-reflectivity electrode, and the sheet resistance (due to increased thickness) of the cathode 210 during driving can be reduced.

[0088] It should be noted that when the light-emitting device is upright (opposite to the arrangement of the light-emitting device used in this disclosure), the anode of the light-emitting device will be below and the cathode will be above. The cathode is made of metal material in the same layer. Even if its thickness is reduced to make the cathode transparent, its transmittance will be small (semi-transparent), and the light output efficiency will be limited, which will be less than the light output efficiency of the light-emitting device used in this disclosure when it is inverted.

[0089] In at least one embodiment of this disclosure, the first functional layer 221 includes an electronic material, and the second functional layer 223 includes a hole-based material. For example, the first functional layer 221 includes at least one of an electron injection layer and an electron transport layer. For example, the second functional layer 223 includes at least one of a hole injection layer and a hole transport layer. For example, a hole blocking layer may be provided in the first functional layer 221, and an electron blocking layer may be provided in the second functional layer 223.

[0090] In the embodiments of this disclosure, the number of functional groups 220A included in the light-emitting device 200 is not limited. For example, each light-emitting device 200 can be configured as follows: Figure 6 The diagram shows only one functional group 220A; alternatively, each light-emitting device 200 can be configured as follows: Figure 7 The diagram shows only two or more functional groups 220A. Below, we will describe the specific arrangement of each film layer of the light-emitting device 200 through different embodiments, depending on the chosen option.

[0091] In some embodiments of this disclosure, such as Figure 6 As shown, the light-emitting functional layer 220 of the light-emitting device 200 includes only one functional group 220A, with one first functional layer 221, one light-emitting layer 222, and one second functional layer 223. For example, the optical thickness of the light-emitting layer 222 to the cathode 210 is half the emission wavelength of the light-emitting device 200. In this way, while ensuring that the first functional layer 221, which contains electronic materials, has a large thickness to reduce leakage current, the light-emitting layer 222 is located at the standing wave position of the microcavity structure of the light-emitting device 200, thereby ensuring the light extraction efficiency of the light-emitting device 200.

[0092] In at least one embodiment of this disclosure, as shown in FIG4, the optical thickness of the surface of the light-emitting layer 222 to the anode 230 on the side away from the cathode 210 is 1 / 4 of the emission wavelength of the light-emitting device 200. In this way, the microcavity structure of the light-emitting device 200 can be maintained to ensure the light emission efficiency of the light-emitting device 200.

[0093] In other embodiments of this disclosure, such as Figure 7As shown, the light-emitting functional layer 220 of the light-emitting device 200 includes at least two functional groups 220A, and the number of the first functional layer 221, the light-emitting layer 222, and the second functional layer 223 are all at least two. Thus, the light-emitting device 200 has at least two light-emitting layers 222, thereby achieving high light extraction efficiency to increase the brightness of the displayed image on the display panel. Furthermore, this design allows for more space to adjust the thickness of each film layer of the light-emitting device 200, ensuring that the first functional layer 221 adjacent to the cathode 210 has sufficient thickness to reduce leakage current.

[0094] For example, when function group 220A is set to at least two, such as Figure 7 As shown, the optical thickness of the light-emitting layer 222 in the functional group 220A closest to the cathode 210 to the cathode 210 is half the emission wavelength of the light-emitting device 200. When the light-emitting device 200 has multiple functional groups 220A, there is more space to adjust the thickness of each film layer of the light-emitting device 200. This ensures that the first functional layer 221 adjacent to the cathode 210 has sufficient thickness, while also ensuring that the light-emitting layer 222 is located at the standing wave position of the microcavity structure formed by the light-emitting device 200, thereby ensuring the light emission efficiency of the light-emitting device 200.

[0095] For example, when function group 220A is set to at least two, such as Figure 7 As shown, the optical thickness between adjacent light-emitting layers 222 is 1 / 4 of the emission wavelength of the light-emitting device 200. In this way, each light-emitting layer 222 is located at the standing wave position of the microcavity structure, thereby ensuring the light emission efficiency of the light-emitting device 200.

[0096] For example, when function group 220A is set to at least two, such as Figure 7 As shown, the thickness of the first functional layer 221 in the functional group 220A closest to the cathode 210 is greater than the thickness of the first functional layer 221 in other functional groups 220A. Thus, by increasing the thickness of the first functional layer 221 in the functional group 220A closest to the cathode 210, longitudinal leakage current can be avoided due to breakdown of the first functional layer 221 in the functional group 220A closest to the cathode 210.

[0097] In at least one embodiment of this disclosure, such as Figure 7 As shown, when functional groups 220A are set to at least two, the optical thickness of the light-emitting layer 222 closest to the anode 230 to the surface of the anode 230 away from the cathode 210 is 1 / 4 of the emission wavelength of the light-emitting device 200. In this way, each light-emitting layer 222 can be located at the standing wave of the microcavity structure, thereby ensuring the light emission efficiency of the light-emitting device 200.

[0098] In at least one embodiment of this disclosure, such as Figure 7 As shown, when there are at least two functional groups 220A, the light-emitting functional layer 220 also includes a charge generation layer 224 located between adjacent functional groups 220A. The charge generation layer (CGL) is disposed between two functional groups 220A to supply electrons and holes to the functional groups 220A.

[0099] The phenomenon of lateral and longitudinal leakage current at the edge of the light-emitting device is related to the process of fabricating the light-emitting device based on the isolation structure (in the absence of the above-described solution of this disclosure). Therefore, the specific design of the isolation structure and the arrangement relationship between the isolation structure and the light-emitting device will be described below through different embodiments to introduce the background of the technical problem faced by the solution of this disclosure and the specific principle of the solution to the technical problem.

[0100] See again for at least one embodiment of this disclosure. Figure 4A The isolation structure 300 includes a support portion 310 and a crown portion 320. The support portion 310 is located between the substrate 100 and the crown portion 320. The orthographic projection of the surface of the support portion 310 away from the substrate 100 onto the substrate 100 is located within the orthographic projection of the crown portion 320 onto the substrate 100. Thus, the size of the crown portion 320 is larger than the size of the upper part of the support portion 310 to ensure the isolation effect of the isolation structure 300 on the film layer of the light-emitting device 200. In addition, this arrangement can limit the evaporation angle of the film layer of the light-emitting device 200 during evaporation, so as to ensure that the anode 230 can overlap with the isolation structure 300 while reducing the overlap area between the light-emitting functional layer 220 and the isolation structure 300 or avoiding the overlap between the light-emitting functional layer 220 and the isolation structure 300.

[0101] In at least one embodiment of this disclosure, such as Figure 4A As shown, the support portion 310 is a conductive structure, and the edge portion of the anode 230 overlaps with the side surface of the support portion 310. In this way, the conductive support portion 310 can connect the anodes 230 of each light-emitting device 200 in series to form a common electrode. Moreover, the support portion 310 is located in the gap between the light-emitting devices 200, so it does not need to transmit light and is not limited by thickness, thereby reducing the impedance of the common electrode and alleviating the voltage drop problem on each anode 230 when driving the light-emitting device 200.

[0102] In at least one embodiment of this disclosure, such as Figure 4AAs shown, the orthographic projection of the light-emitting functional layer 220 on the substrate 100 lies within the orthographic projection of the anode 230 on the substrate 100. In this way, it can be ensured that the anode 230 and the isolation structure 300 are not completely blocked by the light-emitting functional layer 220, so that the edge portion of the anode 230 can overlap with the isolation structure 300.

[0103] In at least one embodiment of this disclosure, such as Figure 4A As shown, the orthographic projection of the support portion 310 on the substrate 100 lies within the orthographic projection of the crown portion 320 on the substrate 100. Thus, the size of the crown portion 320 is larger than the size of the support portion 310. In the vapor deposition process for fabricating the film layer of the light-emitting device 200 based on the isolation structure 300, the entry angle of the vapor deposition material can be limited based on the edge of the crown portion 320 to control the extension range of the vapor deposition film layer below the crown portion 320, thereby controlling the position of the edge of the vapor deposition film layer. This ensures that the light-emitting functional layer 220 avoids or minimizes overlap with the isolation structure 300, while maximizing the overlap between the anode 230 and the isolation structure 300.

[0104] In at least one embodiment of this disclosure, such as Figure 4B and Figure 5B As shown, in the edge region of the isolation opening 301, the thickness of each film layer of the light-emitting functional layer 220 is smaller closer to the edge of the isolation opening 301 (for details, please refer to the section on...). Figure 13 (See the related description in the illustrated embodiment). When the light-emitting functional layer 220 is formed based on the isolation structure 300, due to the obstruction of the crown 320, the thickness of the light-emitting functional layer 220 at the edges in the region below the crown 320 will be smaller, which makes the film layer easier to break down, resulting in longitudinal leakage current.

[0105] In at least one embodiment of this disclosure, such as Figure 4B and Figure 5B As shown, the first functional layer 221 includes a first part 221A and a second part 221B. The second part 221B surrounds the first part 221A. The orthographic projection of the junction of the first part 221A and the second part 221B on the substrate 100 coincides with the orthographic projection of the edge of the crown 320 on the substrate 100. The orthographic projection of the second part 221B on the substrate 100 is located within the orthographic projection of the crown 320 on the substrate 100. From the junction of the second part 221B and the first part 221A to the edge of the second part 221B away from the first part 221A, the thickness of the second part 221B gradually decreases.

[0106] In some embodiments of this disclosure, such as Figures 3 to 5BAs shown, the isolation structure 300 may only include a support portion 310 and a crown portion 320. In this case, the isolation opening 301 includes a first side 302a and a second side 302b opposite each other along a first direction (e.g., the X-axis direction), and a third side 302c and a fourth side 302d opposite each other along a second direction (e.g., the Y-axis direction). The first and second directions intersect. At the first side 302a and the second side 302b, the edge of the first functional layer 221 of the functional group 220A adjacent to the cathode 210 overlaps with the side surface of the support portion 310. At the third side 302c and the fourth side 302d, the edge of the first functional layer 221 is spaced from the side surface of the support portion 310.

[0107] In other embodiments of this disclosure, the isolation opening 301 includes a first side 302a and a second side 302b opposite to each other along a first direction, and a third side 302c and a fourth side 302d opposite to each other along a second direction. The first and second directions intersect. At the first side 302a, the second side 302b, the third side 302c and the fourth side 302d, the edges of the first functional layer 221 of the functional group 220A adjacent to the cathode 210 overlap with the side surface of the support portion 310. The overlap area of ​​the first functional layer 221 with the support portion 310 at the first side 302a and the second side 302b is greater than the overlap area with the support portion 310 at the third side 302c and the fourth side 302d.

[0108] When depositing a film layer (e.g., the light-emitting functional layer and anode described below) in the light-emitting device 200 based on the isolation structure 300, the deposition source can be moved relative to the display panel along a second direction (e.g., the Y-axis direction), that is, the scanning direction of the deposition is along the X-axis direction, and the deposition source can be a line deposition source, the length direction of which can be parallel to the first direction (X-axis direction). Thus, the vapor-deposited material will have a larger vapor-deposit range (larger vapor-deposit angle) in the first direction (X-axis direction), making it easier for the vapor-deposited material to extend and accumulate at the bottom of the isolation structure 300 to overlap with the isolation structure 300. If a specific film layer in the light-emitting device 200 overlaps with the isolation structure, leakage current will exist between the light-emitting device 200 and the isolation structure 300. That is, at the first side 302a and the second side 302b, the edge of the light-emitting functional layer 220 is more likely to overlap with the support portion 310 of the isolation structure 300. Without adopting the above-mentioned solution of this disclosure, there is a risk of lateral leakage current and longitudinal leakage current at the first side 302a and the second side 302b.

[0109] See again for at least one embodiment of this disclosure. Figure 3The distance D1 between the first side 302a and the second side 302b of the isolation opening 301 is less than the distance D2 between the third side 302c and the fourth side 302d of the isolation opening 301. Thus, the first side 302a and the second side 302b are the long side directions of the isolation opening 301. At the first side 302a and the second side 302b, there is a large connection area between the anode 230 of the light-emitting device 200 and the isolation structure 300, resulting in a relatively small impedance. Therefore, during the evaporation process, the scanning direction of the evaporation is controlled to make it easier for the evaporation material to be deposited at the first side 302a and the second side 302b. However, this also makes it easier for the evaporation film layer (light-emitting functional layer 220) to overlap with the isolation structure 300 at the first side 302a and the second side 302b. That is, at the first side 302a and the second side 302b, the light-emitting functional layer 220 will also have a larger leakage current when connected to the isolation structure 300. By adopting the above-described solution of this disclosure, the leakage current at the first side 302a and the second side 302b can be avoided or reduced.

[0110] In at least one embodiment of this disclosure, such as Figures 8A to 9B As shown, the isolation structure 300 also includes a bottom 340, which is located between the support portion 310 and the substrate 100. The orthographic projection of the support portion 310 on the substrate 100 is located within the orthographic projection of the bottom 340 on the substrate 100.

[0111] In at least one embodiment of this disclosure, such as Figures 8A to 9B As shown, the bottom 340 is a conductive structure, and the anode 230 overlaps with the portion of the bottom 340's surface facing away from the substrate 100 that is not covered by the support portion 310. Compared to the sidewall of the support portion 310, the anode is more easily deposited on the surface area of ​​the bottom 340 facing away from the substrate 100, thereby reducing the impedance at the connection between the anode and the isolation structure 300.

[0112] It should be noted that when the bottom 340 is provided, the anode 230 may overlap only with the bottom 340, or it may overlap with both the side surface of the support 310 and the surface of the bottom 340 that is away from the substrate 100.

[0113] In at least one embodiment of this disclosure, such as Figures 8A to 9B As shown, the orthographic projection of the bottom 340 on the substrate 100 lies within the orthographic projection of the crown 320 on the substrate 100. In this way, the isolation effect of the isolation structure 300 on the light-emitting functional layer 220 can be increased.

[0114] In at least one embodiment of this disclosure, the materials of the bottom 340, the support 310, and the crown 320 are molybdenum, aluminum, and titanium, or titanium, aluminum, and titanium, respectively. The corrosion resistance of aluminum, molybdenum, and titanium increases sequentially, and during etching, the film formed by these materials can form a film such as… Figures 8A to 9B The isolation structure 300 is shown.

[0115] In some embodiments of this disclosure, such as Figure 3 and Figures 8A to 9B As shown, the isolation opening 301 includes a first side 302a and a second side 302b opposite to each other along a first direction, and a third side 302c and a fourth side 302d opposite to each other along a second direction. The first and second directions intersect. At the first side 302a and the second side 302b, the edge of the first functional layer 221 of the functional group 220A adjacent to the cathode 210 overlaps with the surface of the bottom 340 facing away from the substrate 100. At the third side 302c and the fourth side 302d, the edge of the first functional layer 221 is spaced from the surface of the bottom 340 facing away from the substrate 100. For example, the first and second directions are perpendicular.

[0116] In other embodiments of this disclosure, the isolation opening 301 includes a first side 302a and a second side 302b opposite to each other along a first direction, and a third side 302c and a fourth side 302d opposite to each other along a second direction. The first and second directions intersect. At the first side 302a, the second side 302b, the third side 302c, and the fourth side 302d, the edges of the first functional layer 221 of the functional group 220A adjacent to the cathode 210 overlap with the surface of the bottom 340 away from the substrate 100. The overlap area of ​​the first functional layer 221 with the surface of the bottom 340 away from the substrate 100 at the first side 302a and the second side 302b is greater than the overlap area with the surface of the bottom 340 away from the substrate 100 at the third side 302c and the fourth side 302d. For example, the first and second directions are perpendicular.

[0117] When depositing a film layer (e.g., the light-emitting functional layer and anode described below) in the light-emitting device 200 based on the isolation structure 300, the deposition source can be moved relative to the display panel along a second direction (e.g., the Y-axis direction), that is, the scanning direction of the deposition is along the X-axis direction, and the deposition source can be a line deposition source, the length direction of which can be parallel to the first direction (X-axis direction). Thus, the vapor-deposited material will have a larger vapor-deposit range (larger vapor-deposit angle) in the first direction (X-axis direction), making it easier for the vapor-deposited material to extend and accumulate at the bottom of the isolation structure 300 to overlap with the isolation structure 300. If a specific film layer in the light-emitting device 200 overlaps with the isolation structure, leakage current will exist between the light-emitting device 200 and the isolation structure 300. That is, at the first side 302a and the second side 302b, the edge of the light-emitting functional layer 220 is more likely to overlap with the bottom 340 of the isolation structure 300. Without adopting the above-mentioned solution of this disclosure, there is a risk of lateral leakage current and longitudinal leakage current at the first side 302a and the second side 302b.

[0118] In at least one embodiment of this disclosure, when the isolation structure 300 is provided with a bottom 340, the distance between the first side 302a and the second side 302b of the isolation opening 301 is less than the distance between the third side 302c and the fourth side 302d of the isolation opening 301. Thus, the first side 302a and the second side 302b are along the long side of the isolation opening 301. At the first side 302a and the second side 302b, there is a large connection area between the anode 230 of the light-emitting device 200 and the isolation structure 300, resulting in a relatively small impedance. Therefore, during the evaporation process, the scanning direction of the evaporation is controlled to make it easier for the evaporation material to be deposited at the first side 302a and the second side 302b. However, this also makes it easier for the evaporation film layer (light-emitting functional layer 220) to overlap with the bottom 340 of the isolation structure 300 at the first side 302a and the second side 302b. That is, when the light-emitting functional layer 220 is connected to the bottom 340 at the first side 302a and the second side 302b, the leakage current will be larger. By adopting the above-described solution of this disclosure, the leakage current at the first side 302a and the second side 302b can be avoided or reduced.

[0119] In at least one embodiment of this disclosure, such as Figure 8A As shown, the display panel may further include a pixel defining layer 330, which is located on the substrate 100 and includes pixel openings 302 corresponding to the isolation openings 301 respectively. The pixel openings 302 are connected to the corresponding isolation openings 301. The light-emitting functional layer 220 of the light-emitting device 200 fills the pixel openings 302 and extends to the surface of the pixel defining layer 330 away from the substrate 100.

[0120] In at least one embodiment of this disclosure, the pixel defining layer 330 includes an inorganic film layer. The inorganic film layer is denser and has high insulation properties. In the process of fabricating the light-emitting device 200 based on the isolation structure 300, the pixel defining layer 330 does not need a high thickness to accommodate the light-emitting device 200, thus facilitating a thinner and lighter display panel design. Furthermore, the pixel defining layer 330 including the inorganic film layer can have a higher bonding strength with the isolation structure 300 and the cathode 210, reducing the risk of the isolation structure 300 and the cathode 210 detaching. Additionally, the high density of the inorganic film layer can more effectively block the intrusion of water, oxygen, etc., thereby improving the encapsulation effect of the display panel. Moreover, when the pixel defining layer 330 is an inorganic layer, it can have a smaller thickness, thereby reducing the discontinuity at the edge of the pixel opening 302, improving the film continuity of the anode 230 at that location, reducing the impedance of the anode 230, and thus ensuring the display effect of the display panel.

[0121] In at least one embodiment of this disclosure, such as Figure 8A As shown, the orthographic projection of the pixel opening 302 on the substrate 100 is located within the orthographic projection of the isolation opening 301 on the substrate 100. In this way, the thickness of the portion of the vapor-deposited film layer falling in the pixel opening 302 can be relatively uniform, so as to ensure the luminous efficiency and quality of the luminous area (the area defined by the pixel opening 302) of the light-emitting device 200.

[0122] In at least one embodiment of this disclosure, such as Figure 8A As shown, the orthographic projection of the pixel opening 302 onto the substrate 100 lies within the orthographic projection of the cathode 210 onto the substrate 100, and the edge portion of the cathode 210 lies between the pixel defining layer 330 and the substrate 100. The pixel opening 302 exposes at least a portion of the cathode 210. The pixel defining layer 330 can space the conductive isolation structure 300 and the cathode 210 of the light-emitting device 200, thereby allowing the gap between the light-emitting devices 200 to have a smaller design size, thereby increasing the pixel density (PPI) of the display panel.

[0123] See again for at least one embodiment of this disclosure. Figure 4AThe pixel defining layer 330 is located between the isolation structure 300 and the substrate 100. When the pixel defining layer 330 is provided in the display panel, the cathode 210 of the light-emitting device 200 can be designed to have a larger area to avoid positional misalignment between the cathode 210 and the isolation structure 300 during actual manufacturing (errors caused by process precision), which would make it difficult to guarantee the actual light-emitting area of ​​the light-emitting device, thereby improving the aperture ratio (related to the light-emitting area of ​​the light-emitting device) and brightness of the displayed image of the display panel. For example, without the pixel defining layer 330, to avoid connection between the cathode 210 and the isolation structure 300, the design area of ​​the cathode 210 is limited. If the position of the cathode 210 is misaligned, the light-emitting area of ​​the light-emitting device may be smaller than the designed area (the light-emitting area expected during design), resulting in a decrease in the brightness of the light-emitting device.

[0124] In at least one embodiment of this disclosure, such as Figure 4A and Figure 8A As shown, the display panel may further include a first encapsulation layer 410, which is located on the side of the light-emitting device 200 away from the substrate 100 and includes multiple encapsulation units 411. The encapsulation units 411 respectively cover the corresponding isolation openings 301 of the light-emitting device 200. During the batch fabrication of the light-emitting device 200 based on the isolation structure 300, the encapsulation units 411 are fabricated synchronously with the light-emitting device 200, so that in the process of fabricating the next batch of light-emitting devices 200 (in which etching occurs), the light-emitting device 200 can protect the already fabricated light-emitting device 200.

[0125] In cases where the light-emitting device 200 is divided into multiple types that emit different colors of light, each light-emitting device 200 emitting different colors of light is manufactured independently. However, the film layer (evaporated film layer, such as the light-emitting functional layer, etc.) in each light-emitting device 200 is deposited on the entire display panel during the evaporation process. For example, see [link to previous section]. Figures 2 to 5BThe light-emitting devices 200 are classified into three types: a first type (P1), a second type (P2), and a third type (P3) that emit light of different colors. During the fabrication process, light-emitting devices P1, P2, and P3 are fabricated sequentially. When fabricating light-emitting device P1, a light-emitting device P1 is formed in each isolation opening 301. A first encapsulation layer 410 is fabricated on the display panel to cover light-emitting device P2. Then, the first encapsulation layer 410 in some isolation openings 301 (used to form light-emitting devices P2 and P3 in the final product), as well as the anode and light-emitting functional layer of light-emitting device P1, are removed to obtain encapsulation unit 411. In this process, the encapsulation unit 411 protects the light-emitting devices P1 in other isolation openings 301. Based on this method, light-emitting devices P2 and P3 are then fabricated sequentially, ultimately forming the first encapsulation layer 410 as shown in Figure 8. That is, the first encapsulation layer 410 on the entire display panel is obtained through multiple processes. This process can be found below. Figures 12A to 12H The relevant descriptions in the embodiments are not repeated here.

[0126] For example, the first type of light-emitting device (P1), the second type of light-emitting device (P2), and the third type of light-emitting device (P3) can emit red light, green light, and blue light respectively (in no particular order).

[0127] For example, the encapsulation unit 411 extends to the side of the isolation structure 300 facing away from the substrate 100. The portion of the encapsulation unit 411 located on the side of the isolation structure 300 facing away from the substrate 100 is a suspended portion 4111, which is spaced apart from the isolation structure 300. In the above process, since the film layers used to form the structure of the light-emitting device 200 are separated by the isolation structure 300, these film layers are deposited on the display panel in their entirety. That is, these film layers cover the isolation structure 300. In the etching process of forming the encapsulation unit 411, the etching material etches the portion of the film layer covering the isolation structure 300, thereby making the edge portion of the encapsulation unit 411 suspended, thus forming the suspended portion 4111.

[0128] In at least one embodiment of this disclosure, such as Figure 10As shown, the display panel further includes a second encapsulation layer 420 and a third encapsulation layer 430 covering the first encapsulation layer 410. The second encapsulation layer 420 is located between the first encapsulation layer 410 and the third encapsulation layer 430, and the third encapsulation layer 430 is located on the side of the second encapsulation layer 420 facing away from the substrate 100. The first encapsulation layer 410, the second encapsulation layer 420, and the third encapsulation layer 430 constitute an encapsulation structure 400. Optionally, the second encapsulation layer 420 is a planarization layer. Optionally, the second encapsulation layer 420 includes an organic film layer, and the third encapsulation layer 430 includes an inorganic film layer. Optionally, the second encapsulation layer 420 and the third encapsulation layer 430 are continuous film layers. The second encapsulation layer 420 can improve the flatness of the display panel surface, so as to facilitate the placement of other components on the encapsulation layer. In addition, the second encapsulation layer 420 can have a certain degree of flexibility to relieve the stress of the first encapsulation layer 410 and the third encapsulation layer 430, thereby improving the reliability of the display panel and making it more suitable for application in the field of flexible displays. Furthermore, the third encapsulation layer 430 has high density and a high barrier effect against water, oxygen, etc., and the third encapsulation layer 430 has higher strength, so as to facilitate the fabrication of other components (such as touch-related structures, optical films, etc.) on it.

[0129] In at least one embodiment of this disclosure, such as Figure 10 As shown, the substrate 100 may include a substrate and a driving circuit layer located on the substrate. The driving circuit layer includes multiple pixel driving circuits located in the display area, and the display function layer is located on the side of the driving circuit layer away from the substrate. For example, the pixel driving circuit may include multiple transistors (TFTs), capacitors, etc., and may be formed in various forms such as 2T1C (i.e., 2 transistors (TFTs) and 1 capacitor (C)), 3T1C, or 7T1C. The pixel driving circuit is connected to the light-emitting device 200 to control the switching state and brightness of the light-emitting device 200.

[0130] At least one embodiment of this disclosure provides a display panel including a substrate, an isolation structure, and a plurality of light-emitting devices located on the substrate. The isolation structure encloses a plurality of isolation openings, with the light-emitting devices corresponding to the isolation openings. Each light-emitting device includes a cathode, a light-emitting functional layer, and an anode sequentially stacked on the substrate, with the light-emitting functional layer and anode of the light-emitting device at least partially located within the corresponding isolation opening. The light-emitting functional layer includes at least one functional group, comprising a first functional layer, a light-emitting layer, and a second functional layer arranged sequentially from the cathode to the anode. The optical thickness from the light-emitting layer closest to the cathode to the cathode is greater than the optical thickness from the light-emitting layer closest to the anode to the anode. Thus, the light-emitting device is configured to be inverted, i.e., the cathode of the light-emitting device is positioned facing the substrate. In this configuration, the first functional layer is primarily an electron-conducting film, while the second functional layer is primarily a hole-conducting film. The conductivity of the electron-conducting film is less than the conductivity of the hole-conducting film. Compared to a normally positioned light-emitting device, this reduces the risk of lateral leakage. Furthermore, by increasing the thickness of the first functional layer (primarily an electron-conducting film), the risk of longitudinal leakage at the edge of the light-emitting device is further reduced. This can reduce the power consumption of the display panel, increase the lifespan of the light-emitting devices, and improve the visual effect of the displayed image (e.g., improve low grayscale image quality). The structure of this display panel can be found in the aforementioned embodiments (e.g., Figure 6 and Figure 7 The relevant descriptions in the embodiments (etc.) will not be repeated here.

[0131] At least one embodiment of this disclosure provides a method for manufacturing the above-described display panel, the method including, for example, Figure 11 Steps S100 to S700 are as follows.

[0132] S100 provides a substrate and forms a plurality of cathodes spaced apart from each other on the substrate.

[0133] S200, forming an isolation structure, wherein the isolation structure encloses and forms multiple isolation openings, and the isolation openings correspond to the cathode respectively.

[0134] S300, depositing a light-emitting material thin film and a conductive material thin film, the light-emitting material thin film and the conductive material thin film covering the isolation structure and the isolation opening, wherein the portions of the light-emitting material thin film and the conductive material thin film located in the isolation opening can respectively form the light-emitting functional layer and the anode, and the cathode, the light-emitting functional layer and the anode stacked on top of each other constitute a light-emitting device.

[0135] S400 involves depositing encapsulation material layers to cover the luminescent material film and the conductive material film.

[0136] S500 forms a photoresist layer on the packaging material film layer and performs a patterning process on the photoresist layer to form a photoresist pattern, which covers part of the isolation opening.

[0137] S600 etches a packaging material film, a light-emitting material film, and a conductive material film based on a photoresist pattern. The remaining portion of the packaging material film forms a packaging unit, and the portions of the light-emitting material film and the conductive material film not covered by the packaging unit are etched.

[0138] S700, repeat the above process to form a light-emitting device and a packaging unit at the isolation opening where no light-emitting device is formed.

[0139] In the display panel obtained in steps S100 to S700 above, the light-emitting device is inverted, that is, the cathode of the light-emitting device is positioned facing the substrate. Thus, the first functional layer is a film layer that primarily conducts electrons, while the second functional layer is a film layer that primarily conducts holes. The conductivity of the electron-conducting film layer is lower than that of the hole-conducting film layer. Compared to placing the light-emitting device upright, this reduces the risk of lateral leakage. Furthermore, by adjusting the thickness of the first functional layer to ensure that the spacing between the light-emitting layer and the cathode meets the above conditions, not only can the light-emitting layer be positioned at the standing wave position of the microcavity structure formed by the light-emitting device, increasing the light extraction efficiency of the light-emitting device, but the thickness of the first functional layer (primarily an electron-conducting film layer) can also be increased to further reduce the risk of longitudinal leakage at the edges of the light-emitting device. This reduces the power consumption of the display panel, increases the lifespan of the light-emitting device, and improves the visual effect of the displayed image (e.g., improving low grayscale image quality).

[0140] Below, as follows Figure 4A Taking the display panel shown as an example, the manufacturing method of the display panel will be illustrated by way of example.

[0141] like Figure 12A As shown, a substrate 100 is provided and cathodes 210 arranged in an array are formed on the substrate 100.

[0142] like Figure 12B As shown, a pixel defining material layer 330a is formed on a substrate 100 on which a cathode 210 is formed.

[0143] like Figure 12C As shown, a first material layer 310a and a second material layer 320a are formed on the pixel defining material layer 330a.

[0144] For example, the material of the first material layer 310a can be aluminum, and the material of the second material layer 320a can be titanium.

[0145] like Figure 12DAs shown, the first material layer 310a and the second material layer 320a are patterned such that the first material layer 310a is formed as a support portion 310 and the second material layer 320a is formed as a crown portion 320. The support portion 310 and the crown portion 320 define the isolation opening 301 and constitute at least a portion of the isolation structure 300.

[0146] In embodiments of this disclosure, the patterning process can be a photolithographic patterning process, which may include, for example, coating a structural layer to be patterned with photoresist, exposing the photoresist using a photomask, developing the exposed photoresist to obtain a photoresist pattern, etching the structural layer using the photoresist pattern (optionally wet or dry etching), and then optionally removing the photoresist pattern. It should be noted that when the material of the structural layer (e.g., the photoresist pattern described below) includes photoresist, the structural layer can be directly exposed using a photomask to form the desired pattern.

[0147] It should be noted that if the corrosion resistance of the second material layer 320a (e.g., titanium) is greater than that of the first material layer 310a (e.g., aluminum), the etching rate of the first material layer 310a will be greater than that of the second material layer 320a. This will result in the width of the crown 320 being greater than the width of the support portion 310, thus forming a structure as described above. Figure 12D The structure shown.

[0148] like Figure 12E As shown, a patterning process is performed on the pixel defining material layer 330a based on the isolation structure 300 to form a pixel defining layer 330. The pixel defining layer 330 covers the gap between adjacent cathodes 210, so that the planar shape of the pixel defining layer 330 is a grid.

[0149] like Figure 12F As shown, a light-emitting material thin film and a conductive material thin film are vapor-deposited on the substrate 100 to form a light-emitting functional layer 220 and an anode 230 in each isolation opening 301 of the isolation structure 300. The cathode 210, the light-emitting functional layer 220 and the anode 230 stacked on each other at the isolation opening 301 form a light-emitting device 200. No mask is used in the vapor deposition process, so the vapor-deposited material is also deposited on the crown 320. It should be noted that in the actual process, the vapor-deposited material is deposited on the upper surface of the crown 320 away from the substrate 100 and on the sidewalls (not shown in the figure) to form a filling film 500a. Then, an encapsulation material film layer 410a is deposited to cover the light-emitting device 200 and the isolation structure 300.

[0150] For example, the light-emitting layer in the vapor-deposited light-emitting functional layer 220 can be light of the color corresponding to the second type of light-emitting device P2. That is, in this stage, the second type of light-emitting device P2 is formed in each isolation opening 301 of the isolation structure 300.

[0151] like Figure 12G As shown, a photoresist is formed (e.g., coated) on a substrate 100 on which an encapsulation material film layer 410a is formed, and then a patterning process is performed on it to form a photoresist pattern 500, which only covers a portion of the isolation opening 301 of the isolation structure 300.

[0152] like Figure 12H As shown, the surface of the display panel is etched using the photoresist pattern 500 as a mask to remove the encapsulation material film layer 410a, the filling film 500a, the anode 230 and the light-emitting functional layer 220 that are not covered by the photoresist pattern 500. The remaining part of the encapsulation material film layer 410a forms the encapsulation unit of the first encapsulation layer 410. Then, the residual photoresist pattern 500 is removed.

[0153] It should be noted that, in cases such as Figure 12H In the process shown, the filler film 500a can be completely removed, or... The etching degree can be controlled so that at least a portion of the filler film 500a remains to support the suspended portion of the package unit, thereby reducing the risk of package unit breakage.

[0154] Repeat the above Figures 12F to 12H The steps are as follows: to form a first type of light-emitting device P1 and a third type of light-emitting device P3 in other isolation openings 301 respectively, and to form a display panel as shown in FIG4. The process of forming the first type of light-emitting device P1 and the third type of light-emitting device P3 differs from that of forming the second type of light-emitting device P2 in that the isolation openings 301 covered by the photoresist pattern 500 are different.

[0155] like Figure 13 As shown, when depositing the light-emitting functional layer (e.g., the first functional layer), if the deposition source P moves to face the isolation structure 300, the boundary of its deposition angle corresponds to lines A1 and A2 on the display panel. That is, the area between lines A1 and A2 will not be deposited in this case. However, the area on the side of lines A1 and A2 away from the isolation structure 300 will be deposited regardless of the position of the deposition source P. In other words, starting from the area of ​​line A1 or line A2, the closer to the isolation structure 300, the smaller the thickness of the light-emitting functional layer.

[0156] At least one embodiment of this disclosure provides a display device, which may include the display panel in the above embodiments or a display panel obtained by the manufacturing method in the above embodiments. For example, the display device may include a touch structure, an optical film (e.g., a microlens, a polarizer), a cover plate, or other structures disposed on the light-emitting side of the display panel.

[0157] For example, the display device can be any product or component with a display function, such as a television, digital camera, mobile phone, watch, tablet computer, laptop computer, or navigator.

[0158] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0159] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A display panel, characterized in that, include: substrate; An isolation structure is located on the substrate and encloses a plurality of isolation openings; as well as Multiple light-emitting devices are located on the substrate and correspond to the isolation openings, wherein each light-emitting device includes a cathode, a light-emitting functional layer and an anode stacked sequentially on the substrate, and the light-emitting functional layer and the anode of the light-emitting device are at least partially located in the corresponding isolation openings; The light-emitting functional layer includes at least one functional group, which comprises a first functional layer, a light-emitting layer, and a second functional layer arranged sequentially from the cathode to the anode. The optical thickness from the light-emitting layer to the cathode is N times 1 / 4 of the light-emitting wavelength of the light-emitting device, where N is a positive integer not less than 2.

2. The display panel according to claim 1, characterized in that, The anode comprises a high work function material, and the cathode comprises a low work function material; Preferably, the anode comprises indium tin oxide; Preferably, the cathode comprises a metal; Preferably, the cathode comprises at least one of silver, magnesium, and aluminum.

3. The display panel according to claim 1, characterized in that, The first functional layer includes electronic materials, and the second functional layer includes hole materials; Preferably, the first functional layer includes at least one of an electron injection layer and an electron transport layer; Preferably, the second functional layer includes at least one of a hole injection layer and a hole transport layer.

4. The display panel according to any one of claims 1 to 3, characterized in that, The light-emitting functional layer of the light-emitting device includes only one functional group, and the number of the first functional layer, the light-emitting layer and the second functional layer is one each; Preferably, the optical thickness of the light-emitting layer to the cathode is 1 / 2 of the emission wavelength of the light-emitting device.

5. The display panel according to claim 4, characterized in that, The optical thickness of the light-emitting layer to the side of the anode away from the cathode is 1 / 4 of the emission wavelength of the light-emitting device.

6. The display panel according to any one of claims 1 to 3, characterized in that, The light-emitting functional layer of the light-emitting device includes at least two functional groups, and the number of the first functional layer, the light-emitting layer and the second functional layer are all at least two. Preferably, the optical thickness of the light-emitting layer in the functional group closest to the cathode to the cathode is 1 / 2 of the emission wavelength of the light-emitting device. Preferably, the optical thickness between adjacent light-emitting layers is 1 / 4 of the emission wavelength of the light-emitting device. Preferably, the thickness of the first functional layer in the functional group closest to the cathode is greater than the thickness of the first functional layer in the other functional groups.

7. The display panel according to claim 6, characterized in that, The optical thickness of the light-emitting layer closest to the anode to the side of the anode away from the cathode is 1 / 4 of the emission wavelength of the light-emitting device.

8. The display panel according to claim 6, characterized in that, The light-emitting functional layer further includes a charge-generating layer, which is located between adjacent functional groups.

9. The display panel according to any one of claims 1 to 3, characterized in that, The isolation structure includes a support portion and a crown portion, the support portion being located between the substrate and the crown portion, and The orthographic projection of the surface of the support portion away from the substrate onto the substrate is located within the orthographic projection of the crown portion onto the substrate; Preferably, the support portion is a conductive structure, and the edge portion of the anode overlaps with the side surface of the support portion; Preferably, the orthographic projection of the light-emitting functional layer on the substrate is located within the orthographic projection of the anode on the substrate.

10. The display panel according to claim 9, characterized in that, The orthographic projection of the support portion on the substrate is located within the orthographic projection of the crown portion on the substrate.

11. The display panel according to claim 10, characterized in that, In the edge region of the isolation opening, the thickness of each film layer of the light-emitting functional layer is smaller in the portion closer to the edge of the isolation opening; Preferably, the first functional layer includes a first part and a second part, the second part surrounds the first part, the orthographic projection of the junction of the first part and the second part on the substrate coincides with the orthographic projection of the edge of the crown on the substrate, the orthographic projection of the second part on the substrate is located within the orthographic projection of the crown on the substrate, and the thickness of the second part gradually decreases from the junction of the second part and the first part to the edge of the second part away from the first part.

12. The display panel according to claim 10, characterized in that, The isolation opening includes a first side and a second side opposite to each other along a first direction, and a third side and a fourth side opposite to each other along a second direction, wherein the first direction and the second direction intersect. At the first and second sides, the edge of the first functional layer of the functional group adjacent to the cathode overlaps with the side surface of the support; at the third and fourth sides, the edge of the first functional layer is spaced from the side surface of the support. or At the first side, the second side, the third side, and the fourth side, the edges of the first functional layers included in the functional group adjacent to the cathode all overlap with the side surface of the support, and the overlap area of ​​the first functional layer with the support at the first side and the second side is greater than the overlap area with the support at the third side and the fourth side. Preferably, the first direction and the second direction are perpendicular.

13. The display panel according to claim 12, characterized in that, The distance between the first and second sides of the isolation opening is less than the distance between the third and fourth sides of the isolation opening.

14. The display panel according to claim 10, characterized in that, The isolation structure also includes a bottom, which is located between the support and the substrate, and the orthographic projection of the support on the substrate is located within the orthographic projection of the bottom on the substrate. Preferably, the bottom is a conductive structure, and the anode overlaps with the portion of the bottom surface facing away from the substrate that is not covered by the support portion; Preferably, the orthographic projection of the bottom on the substrate lies within the orthographic projection of the crown on the substrate; Preferably, the materials of the bottom, the support portion, and the crown portion are molybdenum, aluminum, and titanium, or titanium, aluminum, and titanium, respectively.

15. The display panel according to claim 10, characterized in that, The isolation opening includes a first side and a second side opposite to each other along a first direction, and a third side and a fourth side opposite to each other along a second direction, wherein the first direction and the second direction intersect. At the first and second sides, the edge of the first functional layer of the functional group adjacent to the cathode overlaps with the bottom surface facing away from the substrate; at the third and fourth sides, the edge of the first functional layer is spaced from the bottom surface facing away from the substrate. or At the first side, the second side, the third side, and the fourth side, the edges of the first functional layers included in the functional group adjacent to the cathode all overlap with the bottom surface away from the substrate, and the overlap area of ​​the first functional layer with the bottom surface away from the substrate at the first side and the second side is greater than the overlap area with the bottom surface away from the substrate at the third side and the fourth side. Preferably, the first direction and the second direction are perpendicular.

16. The display panel according to claim 15, characterized in that, The distance between the first and second sides of the isolation opening is less than the distance between the third and fourth sides of the isolation opening.

17. The display panel according to claim 15, characterized in that, It also includes a pixel defining layer, wherein the pixel defining layer is located on the substrate and includes pixel openings corresponding to the isolation openings. The pixel opening is connected to the corresponding isolation opening, and the light-emitting functional layer of the light-emitting device fills the pixel opening and extends to the surface of the pixel defining layer away from the substrate; Preferably, the pixel defining layer comprises an inorganic film layer; Preferably, the orthographic projection of the pixel opening on the substrate is located within the orthographic projection of the isolation opening on the substrate; Preferably, the orthographic projection of the pixel opening on the substrate is located within the orthographic projection of the cathode on the substrate, and the edge portion of the cathode is located between the pixel defining layer and the substrate; Preferably, the pixel defining layer is located between the isolation structure and the substrate.

18. A display panel, characterized in that, include: substrate; An isolation structure is located on the substrate and encloses a plurality of isolation openings; as well as Multiple light-emitting devices are located on the substrate and correspond to the isolation openings, wherein each light-emitting device includes a cathode, a light-emitting functional layer and an anode stacked sequentially on the substrate, and the light-emitting functional layer and the anode of the light-emitting device are at least partially located in the corresponding isolation openings; The light-emitting functional layer includes at least one functional group, which comprises a first functional layer, a light-emitting layer, and a second functional layer arranged sequentially from the cathode to the anode. The optical thickness of the light-emitting layer closest to the cathode to the cathode is greater than the optical thickness of the light-emitting layer closest to the anode to the anode.

19. A method for manufacturing a display panel, characterized in that, include: A substrate is provided, and a plurality of cathodes spaced apart from each other are formed on the substrate; An isolation structure is formed, wherein the isolation structure encloses and forms a plurality of isolation openings, and the isolation openings correspond to the cathode respectively; A light-emitting material thin film and a conductive material thin film are deposited, wherein the light-emitting material thin film and the conductive material thin film cover the isolation structure and the isolation opening, wherein the portions of the light-emitting material thin film and the conductive material thin film located in the isolation opening can respectively form a light-emitting functional layer and an anode, and the cathode, the light-emitting functional layer and the anode stacked on top of each other constitute a light-emitting device; Deposit an encapsulation material film to cover the luminescent material film and the conductive material film; A photoresist layer is formed on the encapsulation material film, and the photoresist layer is patterned to form a photoresist pattern, the photoresist pattern covering a portion of the isolation opening; The encapsulation material film, the light-emitting material film, and the conductive material film are etched based on the photoresist pattern, wherein the remaining portion of the encapsulation material film forms an encapsulation unit, and the portions of the light-emitting material film and the conductive material film not covered by the encapsulation unit are etched; and The above process is repeated to form the light-emitting device and the packaging unit at the isolation opening where the light-emitting device is not formed.

20. A display device, characterized in that, The display panel includes any one of claims 1 to 18 or a display panel obtained by the preparation method of claim 19.

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