Display panel, display screen and electronic device

Abstract

Provided in the present application are a display panel, a display screen and an electronic device. The display panel comprises a plurality of anodes, a pixel definition layer, a hole function layer, a plurality of light-emitting layers, at least one organic connection layer, an electron function layer and a cathode. Any two adjacent anodes among the plurality of anodes are isolated by the pixel definition layer, and the plurality of anodes, the hole function layer, the plurality of light-emitting layers, the electron function layer and the cathode are successively stacked. Each organic connection layer is connected between two adjacent light-emitting layers; the material of each organic connection layer comprises a host material and a doping material doping the host material, the sheet resistance of each organic connection layer in any transverse direction being greater than or equal to 1GΩ / □, and any transverse direction being perpendicular to the thickness direction of the organic connection layer. The solution of the present application can ameliorate transverse crosstalk between pixels, and can also avoid the defects of traditional partition-type Tandem OLED solutions.

Description

Display panels, displays, and electronic devices

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on June 25, 2023, with application number 202310756435.8 and application name “Display panel, display screen and electronic device”. This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on August 29, 2023, with application number 202311104669.0 and application name “Display panel, display screen and electronic device”. The entire contents of both applications are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of display panels, and in particular to a display panel, a display screen, and an electronic device. Background Art

[0003] Tandem organic light-emitting diodes (Tandem OLEDs) are a type of OLED device structure formed by stacking multiple conventional OLED devices in series via a charge generation layer (CGL). Display panels manufactured using Tandem OLED technology offer high brightness, low power consumption, and a long lifespan.

[0004] However, since CGL has a high lateral conductivity characteristic (i.e., conductivity in the direction parallel to the display panel), it will cause lateral light crosstalk between pixels in the TandemOLED display panel (for example, when a red pixel is adjacent to a blue pixel, the blue pixel will emit red light, causing the blue light emitted by the blue pixel to be impure), resulting in a variety of problems such as reduced color gamut of the screen, color shift, abnormal picture display, etc.

[0005] Summary of the Invention

[0006] Embodiments of the present application provide a display panel, a display screen, and an electronic device, which can improve lateral crosstalk between pixels.

[0007] In the first aspect, an embodiment of the present application provides a display panel comprising a plurality of anodes, a pixel definition layer, a hole functional layer, a plurality of light-emitting layers, at least one organic connection layer, an electronic functional layer and a cathode, wherein any two adjacent anodes among the plurality of anodes are isolated by the pixel definition layer, and the plurality of anodes, the hole functional layer, the plurality of light-emitting layers, the electronic functional layer and the cathode are stacked in sequence; each organic connection layer is connected between two adjacent light-emitting layers; the material of each organic connection layer comprises a main material and an impurity doped in the main material, and the square resistance of each organic connection layer in any lateral direction is greater than or equal to 1 GΩ / □, wherein any lateral direction is perpendicular to the thickness direction of the organic connection layer.

[0008] In this solution, by eliminating the isolation grooves on the PDL or providing isolation structures such as isolation columns, the surface of the PDL in the area between any two anodes is continuous, without protrusions or grooves, which can make the cathode continuous and unbroken, reduce the voltage drop on the cathode, and reduce the power consumed by the cathode, thereby making the driving voltage and power consumption of the display panel lower, and avoiding abnormal pixel lighting. In addition, it can also avoid the addition of additional masks and photolithography processes, thereby simplifying the process and reducing costs. In addition, the reliability of the display panel can be improved. Through the doping modification of the organic connection layer, the organic connection layer has a very high lateral square resistance, which can greatly improve the lateral crosstalk. Since the organic connection layer does not need to be arranged according to the distribution of sub-pixels, the pixel design has no effect on the design of the organic connection layer. Therefore, the design of improving lateral crosstalk through the organic connection layer can be applied to all Tandem OLED products. The design has strong compatibility and can meet the needs of mass production.

[0009] In an implementation of the first aspect, the organic connection layer includes a charge generation layer, and the charge generation layer includes an N-type charge generation layer and a P-type charge generation layer; the P-type charge generation layer and the N-type charge generation layer are stacked and located on the side of the N-type charge generation layer facing the cathode.

[0010] In this solution, an N-type charge generation layer and a P-type charge generation layer are provided to transfer carriers to two light-emitting layers connected in series via an organic connecting layer, so as to realize light emission of a series OLED.

[0011] In an implementation of the first aspect, the main material of the N-type charge generation layer includes an N-type main material, the doping material of the N-type charge generation layer includes an N-type doping material, and the concentration of the N-type doping material is ∈(0%, 100%).

[0012] In this solution, by adjusting the doping concentration of the N-type charge generation layer within this range, the lateral square resistance, longitudinal mobility and charge generation capability of the N-type charge generation layer can be comprehensively adjusted as needed to achieve the purpose of reducing lateral crosstalk.

[0013] In an implementation of the first aspect, the N-type main material includes an organic aromatic material, and / or the N-type doping material includes a metal material with a work function ≤3.5 eV, or a metal oxide material with a work function ≤3.5 eV, or an organic material with a work function ≤3.5 eV, or an organic-metal complex material with a work function ≤3.5 eV.

[0014] In this solution, the above-mentioned N-type main material and N-type doping material have excellent performance and can meet the needs of doping modification.

[0015] In an implementation of the first aspect, the main material of the P-type charge generation layer includes a P-type main material, the doping material of the P-type charge generation layer includes a P-type doping material, and the concentration of the P-type doping material is ∈(0%, 100%).

[0016] In this solution, by adjusting the doping concentration of the P-type charge generation layer within this range, the lateral square resistance, longitudinal mobility and charge generation capability of the P-type charge generation layer can be comprehensively adjusted as needed to achieve the purpose of reducing lateral crosstalk.

[0017] In an implementation of the first aspect, the P-type main material includes an organic aromatic material, and / or the P-type doping material includes an organic material with a lowest unoccupied molecular orbital energy level ≤-3.0 eV, or an inorganic material with a work function ≥3.0 eV.

[0018] In this solution, the above-mentioned P-type main material and P-type doping material have excellent performance and can meet the needs of doping modification.

[0019] In an implementation of the first aspect, the charge generation layer further includes an intermediate layer connected between the N-type charge generation layer and the P-type charge generation layer.

[0020] In this solution, the intermediate layer can play a bridging role and can reduce the potential barrier between the N-type charge generation layer and the P-type charge generation layer.

[0021] In an implementation of the first aspect, the organic connecting layer further includes at least one of a hole blocking layer, an electron transport layer, a hole injection layer and a hole transport layer, wherein the hole blocking layer, the N-type charge generation layer and the P-type charge generation layer are stacked in sequence; the electron transport layer, the N-type charge generation layer and the P-type charge generation layer are stacked in sequence, and when the hole blocking layer is present, the hole blocking layer, the electron transport layer and the N-type charge generation layer are stacked in sequence; the hole injection layer and the P-type charge generation layer are stacked and located on the side of the P-type charge generation layer facing the cathode; the hole transport layer and the P-type charge generation layer are stacked and located on the side of the P-type charge generation layer facing the cathode, and when the hole injection layer is present, the P-type charge generation layer, the hole injection layer and the hole transport layer are stacked in sequence.

[0022] In this solution, by making the organic connection layer also include at least one of a hole blocking layer, an electron transport layer, a hole injection layer and a hole transport layer, the performance of the organic connection layer can be optimized, the generation, injection and transport of carriers can be guaranteed, and it is conducive to realizing the light emission of the series OLED.

[0023] In an implementation of the first aspect, the longitudinal mobility of the organic connecting layer is 10 -1 cm 2 / (V·S)~10 -6 cm 2 / (V·S).

[0024] In this solution, by performing doping modification, the organic connection layer can have a higher longitudinal mobility, which is beneficial to reducing the driving voltage and saving power consumption.

[0025] In an implementation manner of the first aspect, the thickness of each organic connecting layer is less than or equal to 300 nm.

[0026] In this solution, controlling the thickness of the organic connection layer within this range can increase the lateral sheet resistance of the organic connection layer, which is beneficial for reducing lateral crosstalk.

[0027] In one implementation of the first aspect, the plurality of anodes includes a first anode and a second anode, the first anode and the second anode being adjacent, the first anode having a top surface facing the cathode; the portion of the pixel definition layer located between the first anode and the second anode has a slope angle; the acute angle formed by a line connecting any two points on the surface of the cathode facing the pixel definition layer and the top surface is less than or equal to the slope angle; and the acute angle formed by a line connecting any two points on the surface of the cathode facing away from the pixel definition layer and the top surface is less than or equal to the slope angle. Through the above design, the pixel definition layer exhibits a flat structure in the region between any two anodes, and the surface of this region is continuous, without protrusions or grooves. The absence of an isolation structure on such a pixel definition layer allows the cathode to be continuous and unbroken, reducing the voltage drop across the cathode and the power consumed by the cathode. This, in turn, reduces the driving voltage and power consumption of the display panel and avoids abnormal pixel lighting. Furthermore, the photomask and photolithography processes required for the isolation structure can be avoided, thereby simplifying the process and reducing costs. Furthermore, the reliability of the display panel can be improved.

[0028] In an implementation of the first aspect, the display panel further includes an isolation structure formed on the pixel definition layer, and the isolation structure passes through the hole functional layer, multiple light-emitting layers, at least one organic connection layer, the electronic functional layer and the cathode.

[0029] In this solution, the isolation structure physically disconnects the organic connection layer from the light-emitting layer, isolating the sub-pixels of different colors in the display panel and reducing lateral crosstalk. The simultaneous presence of the isolation structure and an organic connection layer with high lateral resistance can enhance this effect, thereby preventing lateral crosstalk. This solution can meet specific product design requirements.

[0030] In one implementation of the first aspect, a display panel includes a plurality of sub-pixels, a portion of the plurality of sub-pixels including a first sub-pixel and a second sub-pixel, the first sub-pixel and the second sub-pixel being adjacent, and an isolation structure being located between the first sub-pixel and the second sub-pixel. By providing isolation structures only between a portion of the sub-pixels, fewer isolation structures are present in the display panel, thereby reducing damage to the cathode, lowering the power consumption of the display panel, and ensuring the display quality of the display panel. Furthermore, it is easier to steer the isolation structure away from directions and locations with poor bending reliability, significantly improving the reliability of the display panel.

[0031] In one implementation of the first aspect, the isolation structure includes a columnar structure. This type of isolation structure has a mature and reliable process and can fully separate sub-pixels of different colors in a display panel to meet specific product design requirements.

[0032] In one implementation of the first aspect, the isolation structure includes a groove, and the side of the pixel definition layer facing away from the cathode serves as the bottom wall of the groove. This isolation structure has a mature and reliable process and can fully separate sub-pixels of different colors in a display panel to meet specific product design requirements.

[0033] In one implementation of the first aspect, the subpixels in the display panel form a true red, green, and blue (RGB) arrangement, a diamond arrangement, a delta arrangement, a tripod arrangement, a pentile arrangement, or a diamond-like arrangement. This solution can be applied to various common pixel arrangements, has strong compatibility, and can meet the needs of mass production.

[0034] In an implementation manner of the first aspect, each light-emitting layer includes a red light-emitting unit, a green light-emitting unit, and a blue light-emitting unit.

[0035] In this solution, the colorization of the display panel can be achieved by directly emitting light from RGB sub-pixels. The design of reducing lateral crosstalk can be applied to the panel architecture that directly emits light from RGB sub-pixels to achieve the colorization of the display panel.

[0036] In an implementation of the first aspect, the display panel includes a first color filter film, which includes multiple first red light filter units, multiple first green light filter units, and multiple first blue light filter units; the first color filter film is located on the side of the cathode facing away from the electron functional layer, or the first color filter film is located on the side of the multiple anodes facing away from the hole functional layer; at least two of the multiple light-emitting layers are respectively used to emit light of different colors, and the multiple light-emitting layers as a whole emit white light; the first red light filter unit is used to filter the white light and emit red light, the first green light filter unit is used to filter the white light and emit green light, and the first blue light filter unit is used to filter the white light and emit blue light.

[0037] In this solution, the colorization of the display panel can be achieved by using white light + the first color filter film. The design of reducing lateral crosstalk can be applied to the panel architecture that achieves the colorization of the display panel by using white light + the first color filter film.

[0038] In an implementation of the first aspect, the display panel includes a color conversion layer, the color conversion layer includes multiple red light conversion units and multiple green light conversion units, the color conversion layer is located on the side of the cathode facing away from the electron functional layer, or the color conversion layer is located on the side of the multiple anodes facing away from the hole functional layer; each of the multiple light-emitting layers is used to emit blue light, the red light conversion unit is used to convert the color of the blue light and emit red light, and the green light conversion unit is used to convert the color of the blue light and emit green light.

[0039] In this solution, the colorization of the display panel can be achieved by using blue light + color conversion layer. The design of reducing lateral crosstalk can be applied to the panel architecture that achieves colorization of the display panel by using blue light + color conversion layer.

[0040] In one implementation of the first aspect, the display panel also includes a second color filter film, which is located on the side of the color conversion layer facing away from the cathode; the second color filter film includes a plurality of second red light filter units, a plurality of second green light filter units, and a plurality of second blue light filter units, the second red light filter unit being used to filter the red light emitted by the red light conversion unit and emit red light, the second green light filter unit being used to filter the green light emitted by the green light conversion unit and emit green light, and the second blue light filter unit being used to filter the blue light and emit blue light.

[0041] In this solution, by adding a second color filter film, the light color of the display panel can be made pure.

[0042] In an implementation of the first aspect, the display panel also includes a substrate, multiple thin film transistors, a covering layer and an encapsulation layer, the multiple thin film transistors are arranged on the side of the substrate facing the multiple anodes, the multiple thin film transistors are electrically connected to the multiple anodes one-to-one, the covering layer is located on the side of the cathode facing away from the electronic functional layer, and the encapsulation layer is located on the side of the covering layer facing away from the cathode; wherein, the first color filter film is located on the side of the encapsulation layer facing away from the covering layer, or on the side of the substrate facing away from the multiple thin film transistors; the color conversion layer is located on the side of the encapsulation layer facing away from the covering layer, or on the side of the substrate facing away from the multiple thin film transistors; a portion of the encapsulation layer is filled in the groove and covers the pixel definition layer.

[0043] In this solution, the design of reducing lateral crosstalk can be applied to common, typical tandem OLED panels, thereby improving the lateral crosstalk problem of such tandem OLED panels.

[0044] In a second aspect, an embodiment of the present application provides a display screen, comprising a cover plate and the display panel, wherein the cover plate is bonded to the display panel.

[0045] The display screen of this solution has a display panel capable of improving lateral crosstalk, so the display screen has better performance and lower cost.

[0046] In a third aspect, an embodiment of the present application provides an electronic device, including a structural member and the display screen, wherein the display screen is fixed to the structural member.

[0047] The electronic device of this solution has a display panel capable of improving lateral crosstalk, so the electronic device has better performance and lower cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] FIG1 is a partial top view of a conventional partitioned Tandem OLED display panel;

[0049] FIG2 is a schematic partial cross-sectional view taken along line AA of FIG1 ;

[0050] FIG3 is a schematic structural diagram of an electronic device according to an embodiment of the present application;

[0051] FIG4 is a schematic structural diagram of another electronic device according to an embodiment of the present application;

[0052] FIG5 is a schematic structural diagram of another electronic device according to an embodiment of the present application;

[0053] FIG6 is a schematic structural diagram of another electronic device according to an embodiment of the present application;

[0054] FIG7 is a schematic structural diagram of another electronic device according to an embodiment of the present application;

[0055] FIG8 is a schematic structural diagram of another electronic device according to an embodiment of the present application;

[0056] FIG9 is a schematic structural diagram of another electronic device according to an embodiment of the present application;

[0057] FIG10 is a schematic structural diagram of another electronic device according to an embodiment of the present application;

[0058] FIG11a is a schematic diagram of a partial cross-sectional structure of a display panel according to the first embodiment;

[0059] FIG11 b is a schematic diagram of a flat structure of the pixel definition layer in the region between any two anodes in Example 1;

[0060] FIG11c is a schematic diagram of a partial cross-sectional structure of a display panel according to another embodiment;

[0061] FIG12 is a schematic cross-sectional view of the organic connection layer in FIG11a;

[0062] FIG13 is a schematic diagram illustrating the principle of the super-square resistance phenomenon of an organic conductive surface;

[0063] FIG14 is a schematic diagram illustrating the principle of the phenomenon that a metal conductive surface does not have super-square resistance;

[0064] FIG15 is a schematic diagram illustrating the principle of reducing the super-square resistance phenomenon of organic-inorganic hybrid conductive surfaces;

[0065] FIG16 is a simplified connection circuit of sub-pixels in the display panel of FIG11a;

[0066] FIG17 is an IV curve diagram of an OLED device;

[0067] FIG18 is a simulation curve showing the relationship between the lateral square resistance of the organic connection layer, the equivalent resistor 36R and the lighting voltage across the light-emitting unit 3c;

[0068] FIG19 is a schematic diagram of a partial cross-sectional structure of a display panel according to the second embodiment;

[0069] FIG20 is a schematic diagram of a partial cross-sectional structure of a display panel according to the fifth embodiment;

[0070] FIG21 is a schematic diagram of a partial cross-sectional structure of a display panel according to Example 6;

[0071] FIG22 is a schematic diagram of a partial cross-sectional structure of a display panel in an implementation manner of Example 7;

[0072] FIG23 shows a schematic microstructure of the stack from anode to cathode located between adjacent anodes in FIG22;

[0073] FIG24 is a schematic diagram of a partial cross-sectional structure of a display panel in another implementation manner of Example 7;

[0074] FIG25 shows a schematic microstructure of the stack from anode to cathode located between adjacent anodes in FIG24;

[0075] 26-31 are schematic diagrams showing the application of the design for improving lateral crosstalk according to Example 7 in a 2B-in-1 arrangement in a true red, green, and blue array;

[0076] 32-37 are schematic diagrams showing the application of the design for improving lateral crosstalk according to Example 7 in a 1B-in-1 arrangement in a true red, green, and blue array;

[0077] 38-43 are schematic diagrams showing the application of the design for improving lateral crosstalk in a diamond arrangement according to Example 7;

[0078] 44 to 47 are schematic diagrams of partial cross-sectional structures of display panels in different implementations of Example 8;

[0079] 48 and 49 are schematic diagrams of a partial cross-sectional structure of a display panel according to the twelfth embodiment. DETAILED DESCRIPTION

[0080] For ease of understanding, the relevant technical terms involved in the embodiments of this application are explained and described below.

[0081] In the description of the embodiments of the present application, unless otherwise specified, "multiple (layers)" refers to two (layers) or more.

[0082] The terms "first", "second", etc. are used for descriptive purposes only and should not be understood to suggest or imply relative importance or to implicitly indicate the quantity of the technical features indicated. Features qualified as "first" or "second" may explicitly or implicitly include one or more of such features.

[0083] The term "connect" should be interpreted broadly. For example, "connect" can mean either a detachable or non-detachable connection, a direct connection, or an indirect connection through an intermediary. The term "fix" should also be interpreted broadly. For example, "fix" can mean either a direct fixation or an indirect fixation through an intermediary.

[0084] The directional terms used in the embodiments of this application, such as "upper," "lower," "top," and "bottom," are merely references to the directions in the accompanying drawings. These directional terms are intended to better and more clearly illustrate and facilitate understanding of the embodiments of this application. They do not explicitly or implicitly indicate that the devices or components referred to must have a specific orientation, be constructed or operate in a specific orientation, and therefore should not be construed as limiting the embodiments of this application.

[0085] In the description of the embodiments of this application, unless otherwise specified, "and / or" is simply a description of an association relationship between associated objects, indicating that three relationships can exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone.

[0086] The embodiment of this application first describes the traditional partition-type Tandem OLED solution.

[0087] FIG1 is a partial top view of a partitioned tandem OLED display panel (hereinafter referred to as the display panel), wherein the viewing direction is perpendicular to the xy plane, and any direction in the xy plane can be referred to as the horizontal direction.

[0088] As shown in FIG1 , the display panel 1 is provided with a plurality of sub-pixels arranged in an array (illustrated by dashed boxes), such as sub-pixel 1a, sub-pixel 1b, and sub-pixel 1c. Essentially, a spacer (illustrated by thick black lines) is provided between any two adjacent sub-pixels, such as spacer 12 and spacer 13. There are a large number of spacer columns, distributed at multiple locations within the display panel 1, and these spacer columns may be crisscrossed. Adjacent sub-pixels are separated by spacer columns, which serve to block lateral crosstalk between the sub-pixels.

[0089] FIG2 is a schematic partial cross-sectional view taken along line AA of FIG1 , wherein the sight line direction is perpendicular to the xz plane, the direction along the z-axis may be referred to as the longitudinal direction, and the transverse direction may be the direction along the x-axis.

[0090] As shown in FIG2 , the display panel 1 may include a substrate 11, thin film transistors (TFT) 121, TFT 122, and TFT 123, anodes 131, 132, and 133, a pixel definition layer (PDL) 14, isolation columns 12 and 13, emitting layers (EML) 151, 152, and 153, a plurality of CGLs 16, emitting cells 171, 172, and 173, emitting cells 181, 182, and 183, a cathode 19, a capping layer (CPL) 110, and an encapsulation layer 111.

[0091] Each light-emitting unit contributes to the formation of a sub-pixel. For example, as shown in FIG1 and FIG2 , sub-pixel 1a may include light-emitting unit 151, light-emitting unit 171, and light-emitting unit 181; sub-pixel 1b may include light-emitting unit 152, light-emitting unit 172, and light-emitting unit 182; and sub-pixel 1c may include light-emitting unit 153, light-emitting unit 173, and light-emitting unit 183. Multiple light-emitting units arranged along the z-axis can emit light of the same color. For example, light-emitting unit 151, light-emitting unit 171, and light-emitting unit 181 can emit red light. Multiple light-emitting units arranged along the x-axis can emit light of different colors. For example, light-emitting unit 151, light-emitting unit 152, and light-emitting unit 153 can emit red, green, and blue light, respectively.

[0092] As shown in FIG2 , a CGL 16 is provided between every two layers of light emitting units, and every two layers of light emitting units are connected in series through the CGL 16. The number of series layers of light emitting units can be set as needed (“…” in FIG2 indicates omitted light emitting unit layers and CGL 16).

[0093] As shown in FIG2 , the isolation columns 12 and the isolation columns 13 are both formed on the PDL 14. In conjunction with FIG1 , the isolation columns (e.g., the isolation columns 12) partially disconnect the layer from the light-emitting unit 151 to the cover layer 110. The isolation columns separate adjacent light-emitting units (e.g., the light-emitting unit 151 and the light-emitting unit 152) on the same layer in some lateral directions, and disconnect multiple CGLs 16 from the cathode 19 in the lateral direction. In conjunction with FIG1 , in order to ensure that the cathode 19 can work normally, the isolation columns do not isolate the cathode 19 in all lateral directions, that is, the isolation columns do not divide the cathode 19 into multiple isolated regions, but rather allow each region of the cathode 19 to remain conductive. Accordingly, the isolation columns do not isolate the CGL 16 in all lateral directions, and each region of the CGL 16 remains conductive.

[0094] The above-mentioned partitioned Tandem OLED solution achieves the purpose of partial disconnection of CGL 16 by means of physical isolation, thereby reducing lateral crosstalk. However, as mentioned above, CGL16 is not disconnected in all lateral directions, and each area of ​​CGL16 is still conductive, which causes lateral crosstalk to still exist. Since the cathode 19 will be partially disconnected and discontinuous, the surface impedance of the cathode 19 will increase, the voltage drop (current and resistance drop, IR drop) on the cathode 19 will increase, and the power consumed by the cathode 19 will increase, which will lead to higher driving voltage and power consumption of the display panel 1. Especially when the number of isolation columns is large, the damage to the cathode 19 is great, causing the high power consumption defect to become more obvious. In addition, the disconnection of the cathode 19 will also cause abnormal pixel lighting. In addition, the preparation of the isolation column requires one or two additional photolithography masks and photolithography steps, which requires the introduction of additional processes, resulting in increased costs. In addition, the display panel 1 will also have reliability issues. After the display panel 1 is subjected to scenes such as bending, long-term high brightness, and squeezing, the performance of the display panel 1 is easily degraded due to the failure of the isolation columns. For example, the display panel 1 may have defects such as dark spots, black spots, and abnormal pixel luminescence. Especially when the number of isolation columns is large, the reliability defects will become more obvious. Moreover, the isolation structure in the partitioned Tandem OLED solution needs to be arranged according to the distribution of sub-pixels. The pixel design has a great impact on the isolation structure design. The same isolation structure design cannot be directly migrated to all Tandem OLED products, resulting in a lack of design compatibility and difficulty in meeting mass production needs.

[0095] In view of this, the following embodiments of the present application provide an alternative to the traditional partitioned tandem OLED, which can improve or overcome the above-mentioned defects of the traditional partitioned tandem OLED. Detailed description will be given below.

[0096] The embodiments of the present application provide an electronic device, which includes but is not limited to mobile phones (such as straight-screen phones, foldable phones, and curved-screen phones), tablet computers, laptop computers (including foldable laptop computers), smart screens, desktop monitors, smart bracelets, smart watches, mixed reality devices (MR), virtual reality devices (VR), augmented reality devices (AR), and vehicle-mounted devices (such as car computers). The electronic device includes a structural member and a display screen fixed to the structural member. The display screen may include a cover plate and a display panel. The cover plate is bonded to the display panel. The display panel may be a Tandem OLED display panel. The specific forms of several electronic devices are listed below.

[0097] For example, as shown in Figure 3, the electronic device 2 can be a foldable mobile phone, and the electronic device 2 can include a structural member 21 and a display screen 22 fixed on the structural member 21. The structural member 21 can include a middle frame, and the display screen 22 can be installed on the middle frame. The display screen 22 can include a flexible cover and a display panel that fit together. Schematically, when the electronic device 2 is folded, the display screen 22 can be located on the outside, and the electronic device 2 can be an external folding screen mobile phone. In other embodiments, when the electronic device 2 is folded, the display screen 22 can be located on the inside, and this electronic device 2 can be an internal folding screen mobile phone.

[0098] Unlike FIG3 , as shown in FIG4 , the electronic device 2 may be a bar phone, and the display screen 22 may include a rigid cover and a display panel that fit together. Unlike FIG4 , as shown in FIG5 , the electronic device 2 may be a tablet computer.

[0099] As shown in Figure 6, electronic device 2 may be a laptop computer. Electronic device 2 may include a screen portion and a keyboard portion. Structural member 21 may be the housing of the screen portion. Display screen 22 may include a rigid cover plate and a display panel that fit together. Unlike Figure 6, as shown in Figure 7, electronic device 2 may be a smart screen. Structural member 21 may include a midframe. Display screen 22 may be mounted on the midframe. Display screen 22 may include a rigid cover plate and a display panel that fit together.

[0100] As shown in Figure 8 , electronic device 2 may be a smart bracelet, structural member 21 may include a bracket, and display screen 22 may be mounted on the bracket. Display screen 22 may include a rigid cover plate and a display panel that fit together. Unlike Figure 8 , as shown in Figure 9 , electronic device 2 may be a smart watch, structural member 21 may include a case, and display screen 22 may be mounted on the case.

[0101] As shown in Figure 10, electronic device 2 may be VR glasses or MR glasses. Structural member 21 may include a frame, head-mounted display device 23 may be mounted on the frame, and display screen 22 may be located within head-mounted display device 23, which can be considered to be mounted on the frame. Display screen 22 may include a rigid cover plate and a display panel that fit together. When electronic device 2 is MR glasses, head-mounted display device 23 may also include a built-in camera and / or other sensors.

[0102] The display panel according to the embodiment of the present application will be described in detail below.

[0103] Figure 11a illustrates a partial cross-sectional view of the display panel 3 according to Example 1. The display panel 3 may be a Tandem OLED display panel. As shown in Figure 11a, the display panel 3 may include a substrate 30, TFTs 311, 312, and 313, anodes 321, 322, and 323, a PDL 33, a hole-functional layer 34, a light-emitting layer 35a, an organic connection layer 36, a light-emitting layer 37a, an electronic functional layer 38, a cathode 39, a CPL 310, and an encapsulation layer 320.

[0104] It is understandable that Figure 11a only illustrates the positional relationship of the various material layers and does not limit whether the various material layers are directly connected. In addition, the material layers shown in Figure 11a are not all the material layers of the display panel 3. As needed, the display panel 3 may also include other stacked layers, such as a touch layer formed on the encapsulation layer 320, and a polarizer formed on the touch layer. In another embodiment, the display panel 3 may not have the polarizer, and the display panel 3 may be manufactured using a technology that forms a color filter on encapsulation (COE) layer on the encapsulation layer.

[0105] Substrate 30 includes, but is not limited to, rigid glass substrates, flexible substrates, silicon substrates, and other substrates capable of driving the light-emitting layer to emit light. Flexible substrates include, but are not limited to, polyimide (PI) and fabric substrates that can be bent, folded, or arbitrarily changed in shape. Silicon substrates include, but are not limited to, single-crystal silicon wafers.

[0106] A TFT array layer 31a may be formed on the substrate 30. The TFT array layer 31a may include a plurality of TFTs arranged in an array, such as TFT 311, TFT 312, and TFT 313 as shown in FIG11a. Each TFT is used to drive a sub-pixel.

[0107] An anode array layer 32a may be formed on the TFT array layer 31a. The anode array layer 32a includes a plurality of anodes arranged in an array, such as anode 321, anode 322, and anode 323 as shown in FIG11a. Each anode may be made of an inorganic or metallic material, such as indium tin oxide (ITO), titanium (Ti), silver (Ag), or aluminum (Al). Each anode may generate holes under an applied driving voltage, and the holes from the anode migrate toward the light-emitting layer under the applied driving voltage.

[0108] As shown in Figure 11a, PDL 33 can be formed between the anodes to isolate them. PDL 33 does not include any isolation structures, such as isolation trenches or isolation pillars. The area between any two anodes is flat and continuous, with no protrusions or grooves.

[0109] This flat structure can be geometrically described in conjunction with Figure 11b. Figure 11b illustrates a schematic microstructure of a stacked layer extending from the anode to the cathode 39, located between adjacent anodes 321 (or first anode) and 322 (or second anode). As shown in Figure 11b, between anodes 321 and 322, PDL 33 can be droplet-shaped, and its slope angle a can be defined: a tangent line L0 is drawn through the intersection of the curved surface 33a of PDL 33 and the top surface 31b of the anode, and the acute angle formed between tangent line L0 and the top surface 31b is called slope angle a. For the portion of cathode 39 located between adjacent anodes 321 and 322: the acute angle formed between a line connecting any two points on surface 39a of cathode 39 facing PDL 33 and top surface 31b is less than or equal to slope angle a. For example, acute angle b formed between line L1 and top surface 31b is less than slope angle a. The acute angle formed between a line connecting any two points on surface 39b of cathode 39 facing away from PDL 33 and top surface 31b is less than or equal to slope angle a. For example, acute angle c formed between line L2 and top surface 31b is less than slope angle a. Figure 11b only illustrates the case where the acute angle formed between this line and top surface 31b is less than slope angle a. It is easy to understand that there is such a line where the acute angle formed between this line and top surface 31b is equal to slope angle a.

[0110] In this embodiment, since no isolation structure is provided on the PDL 33, the hole functional layer 34, organic connection layer 36, electron functional layer 38, cathode 39, and CPL 310 are all continuous and have no locally disconnected film layers. These layers, such as the hole functional layer 34, organic connection layer 36, electron functional layer 38, cathode 39, and CPL 310, which extend continuously and are interconnected in all regions, can be referred to as common layers.

[0111] As shown in Figure 11a, the hole functional layer 34 can be located above the anode array layer 32a and the PDL 33. The hole functional layer 34 may include a hole injection layer (HIL), a hole transport layer (HTL) and an electron blocking layer. The anode array layer 32a, the hole injection layer, the hole transport layer and the electron blocking layer may be stacked in sequence. The hole injection layer can smoothly inject holes from each anode into the hole transport layer. The material of the hole transport layer can be an aromatic amine material, such as HTC01, etc. The hole transport layer can transport holes to the light-emitting layer. The electron blocking layer is used to block electrons from entering the hole transport layer. In this embodiment, the hole functional layer 34 can be an organic conducting-surface (OCS) structure. In other embodiments, as needed, the hole functional layer 34 may not have an electron blocking layer.

[0112] As shown in FIG. 11 a , a hole functional layer 34 , a light emitting layer 35 a , an organic connection layer 36 , a light emitting layer 37 a , an electron functional layer 38 , a cathode 39 and a CPL 310 may be sequentially stacked.

[0113] The light-emitting layer 35a and the light-emitting layer 37a are connected in series via an organic connecting layer 36, thereby forming a two-light-emitting layer tandem OLED structure. It should be understood that this is merely an example, and the first embodiment does not limit the number of light-emitting layers connected in series. For example, the light-emitting layer can have three or more layers, with any two light-emitting layers connected in series via an organic connecting layer 36.

[0114] In the first embodiment, the light-emitting layer may include a plurality of light-emitting units arranged in a regular array. These light-emitting units include, but are not limited to, red light-emitting units (R), green light-emitting units (G), blue light-emitting units (B), white light-emitting units (W), and yellow light-emitting units (Y). For example, light-emitting layer 35a includes red light-emitting units 351, green light-emitting units 352, and blue light-emitting units 353, and light-emitting layer 37a includes red light-emitting units 371, green light-emitting units 372, and blue light-emitting units 373. The red light-emitting units may be formed by mixing a host material and a red light-emitting material dopant, the green light-emitting units may be formed by mixing a host material and a green light-emitting material dopant, and the blue light-emitting units may be formed by mixing a host material and a blue light-emitting material dopant.

[0115] There may be gaps between the red light emitting unit (R), the green light emitting unit (G), and the blue light emitting unit (B), or they may overlap and be connected. It is understood that in Figure 11a, the red light emitting unit (R), the green light emitting unit (G), and the blue light emitting unit (B) are arranged in sequence along the x-axis. This is only an example. In fact, the arrangement of sub-pixels can be set as needed, and this is not limited in Example 1. For example, multiple adjacent light emitting units in a certain area can emit the same color light or different colors of light.

[0116] As shown in Figure 11a, the height of the red light emitting unit can be greater than the height of the green light emitting unit, and the height of the green light emitting unit can be greater than the height of the blue light emitting unit. For example, the height of the red light emitting unit 351 can be greater than the height of the green light emitting unit 352, and the height of the green light emitting unit 352 can be greater than the height of the blue light emitting unit 353. Here, the height refers to the size of the light emitting unit along the z-axis direction, or is called the thickness. The heights of the red light emitting unit (R), the green light emitting unit (G), and the blue light emitting unit (B) are reduced in sequence. A microcavity structure can be constructed for the red light emitting unit (R), the green light emitting unit (G), and the blue light emitting unit (B), respectively. The microcavity structure can produce a microcavity effect to improve the light extraction rate of the OLED, thereby improving the luminous efficiency and brightness of the OLED.

[0117] In other embodiments, unlike the first embodiment, the height relationship between the red light emitting unit (R), the green light emitting unit (G), and the blue light emitting unit (B) may not be limited. For example, in the display panel 3' shown in Figure 11c, the heights of the light emitting units in each light emitting layer may be consistent or substantially consistent. For example, the heights of the red light emitting unit 351, the green light emitting unit 352, and the blue light emitting unit 353 in the light emitting layer 35a may be consistent or substantially consistent. In addition, the light emitting layer in the display panel 3' may also be three or more layers. For example, Figure 11c shows light emitting layers such as the light emitting layer 35a, the light emitting layer 37a, and the light emitting layer 330a, and any two light emitting layers are connected in series through an organic connecting layer 36.

[0118] In the first embodiment, the light-emitting layer may further include a primer layer, on which light-emitting units are formed. For example, the red light-emitting unit 351, the green light-emitting unit 352, and the blue light-emitting unit 353 in the light-emitting layer 35a are all formed on the primer layer. The primer layer is used to adjust the microcavities of different light colors.

[0119] In the first embodiment, the organic connecting layer 36 has the functions of generating and transporting charges, including electrons and holes, and injecting charges into the light-emitting layer. The organic connecting layer 36 has an extremely small thickness at the nanometer level, which can be less than or equal to 300 nm, such as 2 nm, 10 nm, 50 nm, 100 nm, 300 nm, etc. The organic connecting layer 36 is essentially an organic nanofilm and can include at least one of an organic conducting surface (OCS) and an organic-inorganic hybrid conducting surface (OIHCS). Based on their conductive characteristics, organic conducting surfaces are classified into N-type conducting surfaces, P-type conducting surfaces, and bipolar conducting surfaces. N-type conductive surfaces have a much higher electron mobility than P-type conductive surfaces, and appear to conduct only electrons. Examples include the hole-blocking layer, electron-transport layer, N-CGL, and intermediate layer, which will be described below. P-type conductive surfaces have a much higher hole mobility than electrons, and appear to conduct only holes. Examples include the P-CGL, hole-injection layer, and hole-transport layer, which will be described below. Bipolar conductive surfaces have comparable electron and hole mobilities, and appear to conduct both electrons and holes, such as the intermediate layer. Evaluation metrics for organic conductive surfaces can include surface resistance and longitudinal mobility. For N-CGLs and P-CGLs, additional evaluation metrics include charge generation capability.

[0120] Organic and organic-inorganic hybrid conducting surfaces can be modified through doping to adjust their lateral resistance, longitudinal mobility, and charge generation capacity. By adjusting these properties, lateral crosstalk can be improved, the specific principles of which will be explained below.

[0121] In the first embodiment, as shown in FIG12 , the organic connection layer 36 may include, for example, a hole blocking layer 360, an electron transport layer 361, an N-type CGL 362, a P-type CGL 363, a hole injection layer 364, a hole transport layer 365, and an electron blocking layer 366, stacked in sequence. Referring to FIG12 and FIG11 a , the hole blocking layer 360 may be located adjacent to the light-emitting layer 35 a, and the electron blocking layer 366 may be located adjacent to the light-emitting layer 37 a.

[0122] The hole blocking layer 360 blocks holes in the light-emitting layer 35a from entering the electron transport layer 361, thereby preventing carrier quenching. The electron transport layer 361 transports electrons to the red, green, and blue light-emitting units 351, 352, and 353 near the anode.

[0123] Under an applied driving voltage, holes and electrons are generated at the interface between N-type CGL 362 and P-type CGL 363. N-type CGL 362 transports electrons at the interface between N-type CGL 362 and P-type CGL 363 to the adjacent electron transport layer 361. P-type CGL 363 transports holes at the interface between N-type CGL 362 and P-type CGL 363 to the adjacent hole injection layer 364 or hole transport layer 365.

[0124] In the first embodiment, the N-type CGL 362 and the P-type CGL 363 form a two-layer CGL. In other embodiments, an interlayer may be provided between the N-type CGL 362 and the P-type CGL 363. The interlayer connects the N-type CGL 362 and the P-type CGL 363 and acts as a bridge to reduce the potential barrier between the N-type CGL 362 and the P-type CGL 363. The interlayer may be a single-layer structure or a multi-layer structure, such as a structure with two or more layers. When the interlayer is a single-layer structure, the N-type CGL 362, the interlayer, and the P-type CGL 363 may form a three-layer CGL. When the interlayer is a multi-layer structure, the N-type CGL 362, the interlayer, and the P-type CGL 363 may form a multi-layer CGL.

[0125] The hole injection layer 364 is used to transfer the holes transferred from the P-type CGL 363 to the hole transport layer 365 .

[0126] The hole transport layer 365 is used to transfer holes transferred from the P-type CGL 363 or the hole injection layer 364 to the light-emitting unit.

[0127] The electron blocking layer 366 is used to block electrons in the light emitting layer 37 a from entering the hole transporting layer 365 .

[0128] Unlike the first embodiment, in other embodiments, the organic connection layer may not include any one or more of the hole blocking layer 360, the electron transport layer 361, the hole injection layer 364, the hole transport layer 365, and the electron blocking layer 366. For example, the organic connection layer may include the electron transport layer 361, the N-type CGL 362, the P-type CGL 363, and the hole transport layer 365, but may not include the hole blocking layer 360 and the hole injection layer 364. Alternatively, the organic connection layer may include the N-type CGL 362 and the P-type CGL 363, but may not include the hole blocking layer 360, the electron transport layer 361, the hole injection layer 364, and the hole transport layer 365.

[0129] In the first embodiment, the organic connection layer 36 comprises a host material and a dopant material doped within the host material. Through doping modification, the organic connection layer 36 can have an ultra-high lateral sheet resistance. For example, the sheet resistance in any lateral direction can be greater than or equal to 1 GΩ / □, such as 1 GΩ / □, 10 GΩ / □, 50 GΩ / □, and 196 GΩ / □. This high lateral sheet resistance of the organic connection layer 36 can significantly reduce lateral crosstalk.

[0130] In one embodiment, the N-type CGL 362 is modified by doping. The material of the N-type CGL 362 includes an N-type main material and an N-type dopant material.

[0131] Among them, the N-type host material can be an organic aromatic material, such as an organic material containing pyridine, pyrazine, pyrimidine, triazine, imidazole, phenyl, naphthyl, anthracenyl, phenanthrenyl, pyrene and other groups. Or the N-type host material can be an organic material containing deuterium, tritium, N 15 Isotope-substituted organic materials, such as TmPyPB (1,3,5-tris(3-pyridyl-3-phenyl)benzene), Bphen (4,7-diphenyl-1,10-phenanthroline), TPBi (1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene) and other organic materials.

[0132] Among them, the N-type doping material may include a metal material with a work function of ≤3.5eV, such as ytterbium (Yb), lithium (Li), samarium (Sm), barium (Ba), cesium (Cs) or calcium (Ca), or may include a metal oxide material with a work function of ≤3.5eV, such as lithium oxide (Li2O), lithium carbonate (Li2CO3), cesium oxide (Cs2O), cesium carbonate (Cs2CO3), or may include an organic material with a work function of ≤3.5eV, such as Liq (8-hydroxyquinoline-lithium), Libpp (2-(2',2"-bipyridyl-6'-yl)-phenolate lithium), or an organic-metal complex material with a work function of ≤3.5eV. The doping concentration of the N-type doping material may be less than or equal to 100%, for example, 0% to 3%, and illustratively may be 0.5%.

[0133] In the first embodiment, the material selection of the N-type main material and the N-type dopant material is independent of each other. As needed, any N-type dopant material can be doped into any N-type main material.

[0134] In the first embodiment, when the N-type doping material is an organic material, the N-type CGL 362 formed by doping can be called an organic conductive surface. When the N-type doping material is an inorganic material, the N-type CGL 362 formed by doping can be called an organic-inorganic hybrid conductive surface.

[0135] In one embodiment, the P-type CGL 363 is modified by doping. The material of the P-type CGL 363 includes a P-type main material and a P-type dopant material.

[0136] Among them, the P-type host material includes organic aromatic materials, such as organic materials containing primary amino groups, secondary amino groups, tertiary amino groups, quaternary ammonium groups, phenyl groups, naphthyl groups, anthracenyl groups, phenanthrenyl groups, pyrenyl groups, fluorenyl groups, spirofluorenyl groups and the like. Or the P-type host material can be organic materials containing the above-mentioned groups deuterium, tritium, N 15 Isotope-substituted organic materials, such as TAPC (4-[1-[4-[bis(4-methylphenyl)amino]phenyl]cyclohexyl]-N-(3-methylphenyl)-N-(4-methylphenyl)aniline), NPB (N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine), TCTA (4,4',4'-tris(carbazol-9-yl)triphenylamine) and other organic materials.

[0137] The P-type dopant material may include an organic material with a deep LUMO (lowest unoccupied molecular orbital) energy level, for example, a LUMO energy level ≤ -3.0 eV. Specifically, the P-type dopant material may include organic materials such as NDP-9 (4-({2,3-bis[cyano(4-cyano-2,3,5,6-tetrafluorophenyl)methylidene]cyclopropylidene}(cyano)methyl)-2,3,5,6-tetrafluorobenzene-1-carbonitrile), HAT-CN (2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene), and F4-TCNQ (tetrafluoro-tetracyanoquinodimethane). Alternatively, the P-type dopant material may include an inorganic material having a work function ≥ 3.0 eV, such as indium tin oxide (ITO), molybdenum trioxide (MoO3), vanadium pentoxide (V2O5), ferric chloride (FeCl3), tungsten trioxide (WO3), rhenium trioxide (ReO3), etc. The doping concentration of the P-type dopant material may be less than or equal to 100%, for example, 0% to 20%, and illustratively may be 1%.

[0138] In the first embodiment, the material selection of the P-type main material and the P-type dopant material is independent of each other. As needed, any P-type dopant material can be doped into any P-type main material.

[0139] In the first embodiment, when the P-type dopant material is an organic material, the P-type CGL 363 formed by doping can be referred to as an organic conductive surface. When the P-type dopant material is an inorganic material, the P-type CGL 363 formed by doping can be referred to as an organic-inorganic hybrid conductive surface. In the first embodiment, either the N-type CGL 362 or the P-type CGL 363 can be doped, or both the N-type CGL 362 and the P-type CGL 363 can be doped simultaneously.

[0140] In summary, the organic connection layer 36 may contain at least one of an organic conductive surface and an organic-inorganic hybrid conductive surface. The principle of making the organic connection layer 36 have a high lateral resistance through doping modification will be described below.

[0141] It has been explained above that the organic connecting layer 36 may include an organic conductive surface. The organic conductive surface is essentially an organic nanofilm with an extremely small thickness (for example, the thickness may be less than or equal to 100 nm). Unlike inorganic materials such as metals or semiconductors, the organic conductive surface has a hyper square resistance (HSR) characteristic, that is, as the film thickness of the organic conductive surface decreases, its lateral square resistance changes, generally showing a sharp increase, and the change characteristic of the lateral square resistance with the film thickness does not conform to the resistivity formula R = ρ*L / S, where ρ is the resistivity of the material making the resistor, L is the length of the wire wound into the resistor, S is the cross-sectional area of ​​the wire wound into the resistor, and R is the resistance value.

[0142] The super-sheet resistance characteristics of organic conductive surfaces can be intuitively seen in Tables 1 and 2 below. Tables 1 and 2 show the measured test current (third column), the true sheet resistance calculated using R = U / I (fourth column), and the sheet resistance calculated using the resistivity formula (fifth column) for different device structures derived from reference SID 2022 DIGEST, 877-880 at the same test voltage of 20V. Among them, from NO.5 to NO.1 in Table 1, the film thickness of the organic conductive surface in each device structure decreases successively; from NO.9 to NO.6 in Table 2, the film thickness of the organic conductive surface in each device structure decreases successively; the data in the column of the real sheet resistance calculation result of each row in Table 1 is expressed by the ratio of the real sheet resistance calculation result of each row to the real sheet resistance calculation result of NO.5 (the real sheet resistance calculation result of NO.5 is used as the benchmark 100%), and the data in the column of the resistivity formula calculation result in Table 1 is also subjected to the same benchmark processing; the data in the column of the real sheet resistance calculation result of each row in Table 2 is expressed by the ratio of the real sheet resistance calculation result of each row to the real sheet resistance calculation result of NO.9 (the real sheet resistance calculation result of NO.9 is used as the benchmark 100%), and the data in the column of the resistivity formula calculation result in Table 2 is also subjected to the same benchmark processing.

[0143] Table 1: Calculation results of the square resistance of the organic conductive surface of device structures 1 to 5

[0144] Table 2: Calculation results of the square resistance of the organic conductive surface of device structures 6 to 9

[0145] The mechanism by which organic conducting surfaces have super-square resistance characteristics can be explained by the hypothesis that carriers are transported along molecular orbitals and that carriers are transported differently on the surface and inside of organic conducting surfaces.

[0146] As a comparison, the transport characteristics of carriers in a nanofilm composed of metal, namely a metal conducting-surface (MCS), are first explained. Figure 13 is a schematic diagram illustrating the principle of the super-square resistance characteristics of an organic conducting surface, where a set pixel definition layer gap (PDL gap) (e.g., 20 μm) and a film thickness of 10 nm of the organic conducting surface are used as an example. As shown in Figure 13, for the surface and interior of the metal conducting surface, since the diameter of the metal molecules is less than 0.5 nm (e.g., the radius of the Ag atom is 0.144 nm), the metal molecules are densely packed, and the metal molecules are connected to each other by strong metallic bonds, the connection is relatively tight, and the difference in the transport behavior of carriers inside and on the surface of the film is small, and the transport capacity is the same, so that carriers can quickly pass through the metal nanofilm in the horizontal direction. The carriers will be transported along the shortest path, and the carrier transmission path is approximately equal to the minimum distance between the positive and negative electrodes. Therefore, when the metal conducting surface transmits carriers in the horizontal direction, it follows the resistivity formula R = ρ * L / S, and there is no super-square resistance phenomenon.

[0147] As shown in Figure 14, for organic conductive surfaces, due to the irregular shape and large molecular diameter (reaching the same nanometer scale as the organic conductive surface), intermolecular forces are weaker than covalent, metallic, and ionic bonds. However, due to the numerous benzene rings and conjugated double bonds in the organic materials that make up OLEDs, there is a high degree of π-π stacking between molecules, allowing carriers to more easily transport between molecules through these delocalized π bonds. Since the molecular stacking of organic materials is disordered during film formation, the intermolecular π-π stacking also exhibits disorder, leading to disordered transport channels. This disorder, combined with the two-dimensional nature of the carrier transport channels on the surface of the organic conductive surface and the three-dimensional nature of the carrier transport channels within the organic conductive surface, leads to the conclusion that, on the surface of the organic conductive surface, intermolecular interactions such as π-π stacking are weak, resulting in fewer transport channels and poor transport performance. However, within the organic conductive surface, intermolecular interactions such as π-π stacking are strong, resulting in more transport channels and better transport performance. The closer to the surface of the organic conductive surface, the worse the transmission characteristics, and the surface of the organic conductive surface has the worst transmission characteristics. Therefore, the thinner the organic conductive surface, the higher the proportion of carrier transmission on the film surface, the greater the increase in impedance, and thus the phenomenon of super-square resistance. According to this hypothesis, the larger the orbital size of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO), the weaker the intermolecular interactions such as π-π stacking, and the thinner the organic conductive surface, the more likely the super-square resistance characteristics will appear.

[0148] For comparison, as shown in Figure 15, for an organic-inorganic hybrid conducting surface with a thickness of 10 nm, 5% by weight of metal Yb or Li is doped into organic molecules with a molecular weight of approximately 800 Da. For the surface of the organic-inorganic hybrid conducting surface, the metal and other inorganic materials with low molecular weight fill the gaps between the organic molecules, increasing carrier transport channels and significantly enhancing surface transport capacity, narrowing the gap between the surface and the internal transport capacity of the organic-inorganic hybrid conducting surface. For the interior of the organic-inorganic hybrid conducting surface, the metal and other inorganic materials with low molecular weight fill the gaps between the organic molecules, shortening the internal transport path and enhancing the internal transport capacity. Therefore, when the doping concentration of the inorganic material with low molecular weight and good transport performance is reduced, the sheet resistance of the organic-inorganic hybrid conducting surface will increase significantly, and the super-sheet resistance phenomenon will become more obvious. The same mechanism can be explained for organic conducting surfaces.

[0149] In the first embodiment, by performing doping modification, the longitudinal mobility of the N-type CGL 362 and the P-type CGL 363 can be made similar, for example, the difference between the two can be within 10 times, thereby making the organic connection layer 36 have a higher longitudinal mobility, which is beneficial to reduce the driving voltage and save power. For example, the driving voltage can be reduced by 0.2V to 0.5V. Schematically, the longitudinal mobility of the organic connection layer 36 can reach 10 -6 cm 2 / (V·S)~10 -1 cm 2 / (V·S), for example 10 -6 cm 2 / (V·S), 10 -3 cm 2 / (V·S), 10 -1 cm 2 / (V·S) etc.

[0150] In the first embodiment, the CGL in the organic connection layer 36 can also have a better charge generation capability through doping modification. For example, under an electric field of 8V, the current density of a single charge generation layer device can reach 100mA / cm 2 Improving the charge generation capability is beneficial to improving the current efficiency (for example, the current efficiency can be improved by 3% to 5%), reducing the driving voltage (for example, the driving voltage can be reduced by 0.2V to 0.5V), and improving the lifespan (for example, the lifespan can be increased by 20%).

[0151] In embodiment 1, the electronic functional layer 38 may include a hole blocking layer, an electron transport layer (ETL) and an electron injection layer (EIL), and the hole blocking layer, the electron transport layer, the electron injection layer and the cathode 39 may be stacked in sequence. The hole blocking layer is used to block holes from entering the electron transport layer from the light-emitting layer. The electron injection layer can smoothly inject electrons from the cathode 39 into the electron transport layer, and the electron transport layer can transfer electrons to the light-emitting layer. In this embodiment, the electronic functional layer 38 can be an organic conductive surface structure. In other embodiments, as needed, the electronic functional layer 38 may not have a hole blocking layer and / or an electron injection layer.

[0152] In the first embodiment, the material of the electron transport layer can be an organic aromatic material, such as an organic material containing pyridine, pyrazine, pyrimidine, triazine, imidazole, phenyl, naphthyl, anthracenyl, phenanthrenyl, pyrene and the like, or the material of the electron transport layer can be an organic material containing deuterium, tritium, N 15 Organic materials with isotope substitution, such as TmPyPB (1,3,5-tris(3-pyridyl-3-phenyl)benzene), Bphen (4,7-diphenyl-1,10-phenanthroline), and TPBi (1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene). The electron injection layer can be made of lithium fluoride (LiF), ytterbium (Yb), etc.

[0153] The cathode 39 may include an electron injection layer and a metal cathode, wherein the electron injection layer, the metal cathode, and the CPL 310 are sequentially stacked. Alternatively, the cathode 39 may include an electron injection layer and an alloy cathode, wherein the electron injection layer, the alloy cathode, and the CPL 310 are sequentially stacked. The electron injection layer may be made of, for example, ytterbium (Yb), lithium (Li), lithium fluoride (LiF), 8-hydroxyquinoline lithium (LiQ), calcium (Ca), cesium (Cs), or lithium oxide (Li2O). The metal cathode may be made of, for example, silver (Ag), magnesium (Mg), aluminum (Al), or gold (Au), and the alloy cathode may be made of, for example, an alloy of silver (Ag), magnesium (Mg), aluminum (Al), or gold (Au).

[0154] As shown in FIG11a , in Example 1, cathode 39 can generate electrons under an applied driving voltage, and the electrons from cathode 39 can move toward the light-emitting layer under the driving voltage. In some embodiments, cathode 39 can function as the electron injection layer in the aforementioned electronic functional layer 38, in which case the electronic functional layer 38 may not include an electron injection layer.

[0155] CPL 310 is formed on cathode 39. CPL 310 can be made of a material that exhibits light refraction and light extraction properties, such as lithium fluoride (LiF). CPL 310 can be used to improve light extraction efficiency, adjust light extraction efficiency, and select a specific light spectrum. In some embodiments, CPL 310 may be omitted.

[0156] The encapsulation layer 320 can be formed on the CPL 310. The encapsulation layer 320 can encapsulate the CPL 310, cathode 39, electronic functional layer 38, light-emitting layer 37a, organic connection layer 36, light-emitting layer 35a, hole functional layer 34, PDL 33, anode array layer 32a, and TFT array layer 31a. The encapsulation layer 320 can be a flexible encapsulation method, such as chemical vapor deposition (CVD), thin film encapsulation (TFE), atomic layer deposition (ALD), or any combination of these methods. The encapsulation layer 320 can also be a rigid encapsulation method, such as glass adhesive (Frit) + glass cover encapsulation.

[0157] The following will take the red light emitting unit 351 and the red light emitting unit 371 as examples to illustrate the light emitting principle of the sub-pixels in the display panel 3. The light emitting principles of other light emitting units are the same.

[0158] As shown in Figure 11a, when a driving voltage is applied between cathode 39 and anode 321, electrons from cathode 39 are injected into electron functional layer 38 and transported therein, while holes from anode 321 are injected into hole functional layer 34 and transported therein. Under the action of this driving voltage, in the CGL of organic connection layer 36, carriers transition between different molecular orbitals under the action of the electric field, thereby generating electrons in new molecular orbitals and transporting them to the adjacent electron transport layer 361, while generating holes in old molecular orbitals and transporting them to the adjacent hole injection layer 364 or hole transport layer 365. Holes from anode 321 and electrons from electron transport layer 361 meet in red light emitting unit 351 and recombine to form excitons, which then radiatively transition back to the ground state and emit red light. Electrons from cathode 39 and holes from hole injection layer 364 or hole transport layer 365 meet and recombine in red light-emitting unit 371 to form excitons. The excitons then radiatively transition back to the ground state, emitting red light. As a result, red light-emitting unit 351 and red light-emitting unit 371 can emit red light. This red light can be emitted upward from the CPL 310 (a top-emission architecture) or downward from the substrate 30 (a bottom-emission architecture).

[0159] The principle of how the high lateral square resistance of the organic connection layer 36 can improve the lateral crosstalk will be described below.

[0160] Figure 16 shows a simple connection circuit for the sub-pixels in the display panel 3, which can be used as a model for analyzing the lateral crosstalk of the Tandem OLED. As shown in Figure 16, the light-emitting unit 3a and the light-emitting unit 3b in a sub-pixel are connected in series to form the Tandem OLED. The equivalent resistance 36R corresponding to the organic connecting layer 36 is large. At the rated driving voltage, the light-emitting units 3a and 3b can be illuminated, but due to the voltage division of the equivalent resistance 36R, the voltage across the light-emitting unit 3c is lower than its driving voltage, making it difficult for the light-emitting unit 3c to light up. The larger the equivalent resistance 36R, the lower the voltage across the light-emitting unit 3c, making it more difficult for the light-emitting unit 3c to light up. Therefore, the risk of lateral crosstalk between the light-emitting unit 3a and the light-emitting unit 3b and the light-emitting unit 3c is reduced. Therefore, a general conclusion can be drawn from FIG. 16 : the provision of an organic connection layer 36 with high lateral square resistance can improve lateral crosstalk, and the greater the lateral square resistance, the less likely it is to cause crosstalk.

[0161] The above conclusions will be verified through specific examples below.

[0162] Taking an OLED device described in reference ACS Photonics 2019, 6, 767-778 as an example, the structure of the TandemOLED device is:

[0163] Experimental sheet-R: ITO / HAT-CN (5 nm) / TAPC (50 nm) / TCTA (5 nm) / TPB-AC: 3% Ir(dmdppr-dmp)2(divm) (20 nm) / BmPyPB (40 nm) / LiF (1 nm) / Al (120 nm);

[0164] Experimental sheet-G: ITO / HAT-CN (5 nm) / TAPC (50 nm) / TCTA (5 nm) / TPB-AC: 5% Ir(ppy)2acac (20 nm) / BmPyPB (40 nm) / LiF (1 nm) / Al (120 nm);

[0165] Experimental sheet-B: ITO / HAT-CN (5 nm) / TAPC (50 nm) / TCTA (5 nm) / TPB-AC (20 nm) / BmPyPB (40 nm) / LiF (1 nm) / Al (120 nm).

[0166] The area of ​​the experimental piece is 0.16 cm 2 The IV data of the OLED device are shown in Figure 17. Based on this data, it can be calculated that at a current density of 0.0001 mA / cm2 The internal resistance of the OLED sub-pixel is shown in Table 3 under the conditions that the red sub-pixel size is 20μm×20μm, the green sub-pixel size is 20μm×30μm, and the blue sub-pixel size is 20μm×40μm.

[0167] Table 3: Estimated internal resistance of OLED sub-pixels

[0168] The following calculations are performed using Table 3 and Figure 16. Assume that light-emitting units 3a and 3b are two light-emitting units in a blue Tandem OLED subpixel. For example, light-emitting unit 3a can correspond to blue light-emitting unit 373, and light-emitting unit 3b can correspond to blue light-emitting unit 353. Light-emitting unit 3c is the light-emitting unit on the cathode side of a red Tandem OLED subpixel. For example, light-emitting unit 3c can correspond to red light-emitting unit 371 and green light-emitting unit 372. For example, when blue light is illuminated with red light crosstalk, at low brightness and low grayscale, the internal resistance of light-emitting unit 3a is 2415 GΩ, and the internal resistance of light-emitting unit 3c is 3076 GΩ. Because the activation and driving voltage of a blue OLED is higher than that of a red OLED, for example, when the voltage across light-emitting unit 3a reaches 2.50V, light-emitting unit 3a illuminates (e.g., brightness = 0.02 nit), and when the voltage across light-emitting unit 3c reaches 2.35V, light-emitting unit 3c illuminates (e.g., brightness = 0.02 nit). A voltage of 2.5 V is applied across the parallel circuit formed by the light-emitting unit 3a, the equivalent resistor 36R + the light-emitting unit 3c. When the equivalent resistance of the equivalent resistor 36R exceeds 196 GΩ, the divided voltage across the equivalent resistor 36R exceeds 0.15 V. Since the voltage across the equivalent resistor 36R + the light-emitting unit 3c is 2.5 V, the divided voltage obtained across the light-emitting unit 3c will be less than 2.35 V. It can be concluded that the greater the square resistance of the equivalent resistor 36R, the more difficult it is to light up the light-emitting unit 3c, and the lower the crosstalk risk.

[0169] Figure 18 shows a simulation curve showing the relationship between the lateral sheet resistance of the organic connection layer 36, the equivalent resistance 36R, and the lighting voltage across the light-emitting unit 3c. Figure 18 clearly shows that as the lateral sheet resistance of the organic connection layer 36 increases, the drive voltage across the light-emitting unit 3c drops below the lighting voltage, making it more difficult for the light-emitting unit 3c to light up, thereby reducing the risk of lateral crosstalk.

[0170] In the first embodiment, illustratively, RGB sub-pixels may be directly evaporated using a fine metal mask (FMM) method, and the colorization of the display panel 3 may be achieved by directly emitting light from the RGB sub-pixels.

[0171] The display panel 3 of the first embodiment can be applied to small electronic devices such as mobile phones, tablet computers, laptop computers, smart watches, and smart bracelets.

[0172] In summary, the solution of embodiment 1, by eliminating the isolation structure on the PDL, makes the PDL 33 a flat structure, which can make the cathode 39 continuous and unbroken, reduce the voltage drop on the cathode 39, and reduce the power consumed by the cathode 39, thereby making the driving voltage and power consumption of the display panel 3 lower, and can also avoid abnormal pixel lighting. Moreover, it can also avoid the additional addition of photomasks and photolithography processes, thereby simplifying the process and reducing costs. In addition, the reliability of the display panel 3 can also be improved. By modifying the doping of the organic connection layer 36, the lateral crosstalk can be greatly improved. Since the organic connection layer 36 does not need to be arranged according to the distribution of sub-pixels, the pixel design has no effect on the design of the organic connection layer 36. Therefore, the design of improving the lateral crosstalk through the organic connection layer 36 can be applied to all Tandem OLED products. The design has strong compatibility and can meet the needs of mass production.

[0173] Different from the first embodiment in which colorization is achieved by directly emitting light through RGB sub-pixels, the following embodiments can achieve colorization by using white light + color filter film.

[0174] FIG19 illustrates a partial cross-sectional view of the display panel 4 according to the second embodiment. As shown in FIG11 a, the display panel 4 may include a substrate 40, TFTs 411, 412, and 413, anodes 421, 422, and 423, a PDL 43, a hole functional layer 44, a light emitting layer 45, an organic connecting layer 46, a light emitting layer 47, an electronic functional layer 48, a cathode 49, a CPL 410, an encapsulation layer 420, and a first color filter film (CF) 43a.

[0175] Similar to the first embodiment, the display panel 4 of the second embodiment cancels the isolation structure on the PDL 43, making the PDL 43 a flat structure, which can make the cathode 49 continuous and unbroken, reduce the voltage drop on the cathode 49, and reduce the power consumed by the cathode 39, thereby making the driving voltage and power consumption of the display panel 4 lower, and avoiding abnormal pixel lighting. In addition, it can also avoid the additional addition of mask and photolithography process, thereby simplifying the process and reducing costs. In addition, the reliability of the display panel 4 can also be improved. By doping modification of the organic connecting layer 46, the lateral crosstalk can be greatly improved. The design of improving lateral crosstalk by the organic connecting layer 46 can be applied to all Tandem OLED products. The design has strong compatibility and can meet the needs of mass production.

[0176] Different from the first embodiment, the display panel 4 of the second embodiment can be colored by using white light + color filter film.

[0177] As shown in FIG19 , both light-emitting layer 45 and light-emitting layer 47 are laterally continuous layers of organic material. Deposition of light-emitting layer 45 or light-emitting layer 47 can be completed in a single evaporation process, without using the FMM process, but only using the common metal mask (CMM) process. Light-emitting layer 45 and light-emitting layer 47 can each emit light of different colors, and the light from light-emitting layer 45 and light-emitting layer 47 can mix to produce white light. Illustratively, light-emitting layer 45 can include a red light-emitting unit (R) and a green light-emitting unit (G). The red light emitted by the red light-emitting unit (R) and the green light emitted by the green light-emitting unit (G) can mix to produce yellow light, so that light-emitting layer 45 can emit yellow light. Illustratively, light-emitting layer 47 can include a blue light-emitting unit (B), and light-emitting layer 47 can emit blue light. The yellow light emitted by light-emitting layer 45 can mix with the blue light emitted by light-emitting layer 47 to produce white light, and ultimately all light-emitting layers as a whole emit white light.

[0178] As shown in FIG19 , a first color filter film 43a can be formed on the encapsulation layer 420. The first color filter film 43a can include a plurality of first red light filter units 431, a plurality of first green light filter units 432, and a plurality of first blue light filter units 433. The first red light filter units 431, the first green light filter units 432, and the first blue light filter units 433 can be arranged in a regular array. It will be appreciated that the arrangement of the first red light filter units 431, the first green light filter units 432, and the first blue light filter units 433 along the x-axis is merely an example. In practice, the arrangement of the filter units can be customized as needed and is not limited in the second embodiment.

[0179] As shown in Reference Figure 19, the white light emitted by the entire light-emitting layer can be transmitted upward and enter the first red light filtering unit 431, the first green light filtering unit 432 and the first blue light filtering unit 433 respectively. The first red light filtering unit 431 filters the white light and emits red light, the first green light filtering unit 432 filters the white light and emits green light, and the first blue light filtering unit 433 filters the white light and emits blue light, thereby realizing color display of the display panel 4.

[0180] The display panel 4 of the second embodiment may adopt a top-emission architecture, where light is transmitted upward and emitted from the first color filter 43a above the encapsulation layer 420. In other embodiments, the display panel 4 may adopt a bottom-emission architecture, where the first color filter 43a is located below the substrate 40 (i.e., on the side of the substrate 40 facing away from the light-emitting layer), and light is transmitted downward and emitted from the first color filter 43a below the substrate 40.

[0181] The second embodiment uses white light + color filter film to achieve colorization, which is beneficial to improving the pixel density (pixels per inch, PPI) of the display panel. The display panel 4 of the second embodiment can be applied to electronic devices such as silicon-based OLED TVs or OLED TVs.

[0182] In other embodiments, other white light OLED device structures may be used as needed to achieve colorization using white light + color filter film.

[0183] For example, in Example 3, as shown in FIG19 , light-emitting layer 45 can include blue light-emitting units (B), and light-emitting layer 45 can emit blue light. Light-emitting layer 47 can include red light-emitting units (R) and green light-emitting units (G), and light-emitting layer 45 can emit yellow light. The blue light emitted by light-emitting layer 45 can be mixed with the yellow light emitted by light-emitting layer 47 to form white light. Ultimately, all light-emitting layers as a whole emit white light.

[0184] Alternatively, in the fourth embodiment, a red light-emitting layer, a green light-emitting layer, and a blue light-emitting layer can be provided separately, with the three light-emitting layers stacked (not limited to stacked in sequence), and any two light-emitting layers are connected in series via an organic connecting layer. The red light emitted by the red light-emitting layer, the green light emitted by the green light-emitting layer, and the blue light emitted by the blue light-emitting layer mix to form white light, and ultimately all the light-emitting layers as a whole emit white light.

[0185] Alternatively, in the fifth embodiment shown in FIG20 , two blue-emitting light-emitting layers and one yellow-emitting light-emitting layer may be provided, and white light may be produced by mixing the blue and yellow light. Specifically, as shown in FIG20 , the display panel 5 of the fifth embodiment may include a substrate 50, TFTs 511, TFTs 512, and TFTs 513, anodes 521, 522, and 523, a PDL 53, a hole functional layer 54, a light-emitting layer 55, an organic connection layer 56, a light-emitting layer 57, an organic connection layer 58, a light-emitting layer 59, an electronic functional layer 510, a cathode 520, a CPL 530, an encapsulation layer 540, and a first color filter 55a. The first color filter 55a may include a plurality of first red light filter units 551, a plurality of first green light filter units 552, and a plurality of first blue light filter units 553.

[0186] As shown in Figure 20, the light-emitting layer 55 may include a blue light-emitting unit (B), and the light-emitting layer 55 may emit blue light. The light-emitting layer 57 may include a red light-emitting unit (R) and a green light-emitting unit (G), and the light-emitting layer 57 may emit yellow light. The light-emitting layer 59 may include a blue light-emitting unit (B), and the light-emitting layer 59 may emit blue light. Ultimately, all the light-emitting layers as a whole emit white light. It is understandable that the arrangement order of the light-emitting layer 55-the light-emitting layer 57-the light-emitting layer 59 is only an example. In fact, the arrangement order of each light-emitting layer can be set as needed, and is not limited in Example 5.

[0187] In the Tandem OLED, since the organic light emitting layer has a low efficiency in emitting blue light, it is difficult to emit blue light. Therefore, in the fifth embodiment, an additional light emitting layer emitting blue light is provided to improve the light extraction efficiency of blue light.

[0188] Alternatively, in another embodiment, a first light-emitting layer and a second light-emitting layer may be provided separately and stacked. The first light-emitting layer may include a red light-emitting unit (R) and emit red light; the second light-emitting layer may include a green light-emitting unit (G) and a blue light-emitting unit (B) and emit cyan light. Ultimately, all the light-emitting layers as a whole emit white light.

[0189] Alternatively, in another embodiment, a first light-emitting layer and a second light-emitting layer may be provided separately and stacked. The first light-emitting layer may include a green light-emitting unit (G) and emit green light; the second light-emitting layer may include a red light-emitting unit (R) and a blue light-emitting unit (B) and emit magenta light. Ultimately, all the light-emitting layers as a whole emit white light.

[0190] It is understood that the above examples only illustrate some white light OLED device structures. In the embodiments of the present application, different white light OLED device structures can be configured as needed. These white light OLED device structures meet the following design requirements: among the multiple light-emitting layers, at least two light-emitting layers can emit light of different colors, and the light emitted by all the light-emitting layers can be mixed to form white light, and ultimately all the light-emitting layers as a whole emit white light.

[0191] Different from the above embodiment that uses white light + color filter film to achieve colorization, the sixth embodiment can use blue light + color conversion layer to achieve colorization.

[0192] FIG21 illustrates a partial cross-sectional view of the display panel 6 of Example 6. As shown in FIG21 , the display panel 6 may include a substrate 60, TFTs 611, 612, and 613, anodes 621, 622, and 623, a PDL 63, a hole functional layer 64, a light-emitting layer 65, an organic connection layer 66, a light-emitting layer 67, a light-emitting layer 68, an electronic functional layer 69, a cathode 610, a CPL 620, an encapsulation layer 630, and a color change layer (CCL) 64a. The light-emitting layer 65, the light-emitting layer 67, and the light-emitting layer 68 are stacked in sequence, and two adjacent light-emitting layers are connected in series via an organic connection layer 66.

[0193] Similar to the second embodiment, the display panel 6 of the sixth embodiment eliminates the isolation structure on the PDL 63, making the PDL 63 a flat structure, which can make the cathode 610 continuous and unbroken, reduce the voltage drop on the cathode 610, and reduce the power consumed by the cathode 610, thereby making the driving voltage and power consumption of the display panel 6 lower, and avoiding abnormal pixel lighting. In addition, it can also avoid the additional addition of mask and photolithography processes, thereby simplifying the process and reducing costs. In addition, the reliability of the display panel 6 can also be improved. Through doping modification, the organic connection layer 66 becomes an organic conductive surface. Through doping modification of the organic connection layer 66, the lateral crosstalk can be greatly improved. The design of improving lateral crosstalk through the organic connection layer 66 can be applied to all Tandem OLED products. The design has strong compatibility and can meet the needs of mass production.

[0194] Different from the second embodiment, the display panel 6 of the sixth embodiment can realize colorization by using a blue light+color conversion layer method.

[0195] As shown in FIG21 , the light-emitting layer 65 , the light-emitting layer 67 and the light-emitting layer 68 all include blue light-emitting units (B), and the light-emitting layer 65 , the light-emitting layer 67 and the light-emitting layer 68 can all emit blue light. Ultimately, all the light-emitting layers as a whole emit blue light.

[0196] As shown in Figure 21, a color conversion layer 64a can be formed on the encapsulation layer 630. The color conversion layer 64a can include multiple red light conversion units 641, multiple green light conversion units 642, and multiple blue light conversion units 643. The red light conversion units 641, green light conversion units 642, and blue light conversion units 643 can be arranged in a regular array. It should be understood that the arrangement of the red light conversion units 641, green light conversion units 642, and blue light conversion units 643 along the x-axis is merely an example. In practice, the arrangement of the conversion units can be customized as needed and is not limited in this embodiment.

[0197] As shown in reference figure 21, the blue light emitted by the entire light-emitting layer can be transmitted upward and enter the red light conversion unit 641, the green light conversion unit 642 and the blue light conversion unit 643 respectively. The red light conversion unit 641 can convert the color of the blue light and emit red light, the green light conversion unit 642 can convert the color of the blue light and emit green light, and the blue light conversion unit 643 can narrow the spectrum of the blue light and emit purer blue light, thereby realizing color display of the display panel 6.

[0198] The display panel 6 of the sixth embodiment may adopt a top-emission architecture, where light is transmitted upward and emitted from the color conversion layer 64a above the encapsulation layer 630. In other embodiments, the display panel 6 may adopt a bottom-emission architecture, where the color conversion layer 64a is located below the substrate 60 (i.e., on the side of the substrate 60 facing away from the light-emitting layer), and light is transmitted downward and emitted from the color conversion layer 64a below the substrate 60.

[0199] In the sixth embodiment, illustratively, to ensure the purity of the light color of the display panel 6, a second color filter film may be disposed outside the color conversion layer 64a. The second color filter film may be located on the side of the color conversion layer 64a facing away from the encapsulation layer 630 (a top-emission structure) or on the side of the color conversion layer 64a facing away from the substrate 60 (a bottom-emission structure). The second color filter film may include a plurality of second red light filter units, a plurality of second green light filter units, and a plurality of second blue light filter units. The second red light filter units correspond to the red light conversion units and can filter the red light emitted by the red light conversion units and emit red light. The second green light filter units can filter the green light emitted by the green light conversion units and emit green light. The second blue light filter units can filter the blue light emitted by the blue light conversion units and emit blue light.

[0200] The sixth embodiment uses a blue light + color conversion layer approach to achieve colorization, which simplifies the process, reduces voltage drop, lowers the power consumption of the display panel, and improves the brightness of the display panel. The display panel 6 of the sixth embodiment can be applied to electronic devices such as high-brightness televisions.

[0201] Different from the sixth embodiment, in other embodiments, the color conversion layer may not have a blue light conversion unit, and the second color filter film may include a second blue light filter unit that filters the blue light emitted by the light-emitting layer.

[0202] The above embodiments describe in detail a tandem OLED display panel using a planar PDL and a doped organic connection layer. The following embodiments describe a tandem OLED display panel using a semi-planar + semi-isolated PDL combined with a doped organic connection layer.

[0203] FIG22 is a schematic diagram of a partial cross-sectional structure of a display panel 7 in an implementation of Example 7. As shown in FIG22 , the display panel 7 may include a substrate 70, TFTs 711, 712, and 713, anodes 721, 722, and 723, a PDL 73, a hole functional layer 74, a plurality of light-emitting layers including a light-emitting layer 75, a light-emitting layer 77, and a light-emitting layer 78, a plurality of organic connection layers 76, an electronic functional layer 79, a cathode 710, a CPL 720, an encapsulation layer 730, and an isolation structure 740.

[0204] Among them, any two adjacent light-emitting layers in the display panel 7 can be connected in series through an organic connecting layer 76. Each light-emitting layer can include multiple light-emitting units. For example, the light-emitting layer 75 can include a light-emitting unit 751, a light-emitting unit 752 and a light-emitting unit 753, the light-emitting layer 77 can include a light-emitting unit 771, a light-emitting unit 772 and a light-emitting unit 773, and the light-emitting layer 78 can include a light-emitting unit 781, a light-emitting unit 782 and a light-emitting unit 783. Each light-emitting layer can also include a preset layer, on which the light-emitting unit is formed, and the preset layer is used to adjust the microcavities of different light colors. Schematically, each light-emitting layer can include multiple red light-emitting units, green light-emitting units and blue light-emitting units. For example, the light-emitting unit 771 can be a red light-emitting unit, the light-emitting unit 772 can be a green light-emitting unit, and the light-emitting unit 773 can be a blue light-emitting unit.

[0205] In this embodiment, the RGB sub-pixels can be directly evaporated by the FMM method, and the colorization of the display panel 7 can be achieved by the direct emission of the RGB sub-pixels.

[0206] In this embodiment, except for the isolation structure 740, the structure, materials, characteristics and working principle of the remaining stacked layers can be the same as those in the above embodiment and will not be repeated here. The isolation structure 740 will be described in detail below.

[0207] FIG22 illustrates an isolation structure 740 formed on the PDL 73. The isolation structure 740 can be roughly a columnar structure similar to a pillar. Its specific structure can be designed as needed and is not limited in this embodiment. The isolation structure 740 is relatively tall and can sequentially penetrate the hole functional layer 74, multiple light-emitting layers, multiple organic connection layers 76, the electronic functional layer 79, the cathode 710, and the CPL 720 along the z-axis direction (i.e., the longitudinal direction). The isolation structure 740 makes the hole functional layer 74, the organic connection layer 76, the cathode 710, and the CPL 720 no longer a continuous and complete structure, but partially disconnected. The isolation structure 740 also separates adjacent light-emitting units in each light-emitting layer (for example, the light-emitting unit 751 and the light-emitting unit 752 in the light-emitting layer 75, the light-emitting unit 781 and the light-emitting unit 782 in the light-emitting layer 78, etc.) in some lateral directions. It can be considered that the isolation structure 740 causes each light-emitting layer to be partially disconnected.

[0208] As shown in Figure 22, due to process reasons, cathode material can also be deposited on the top of the isolation structure 740. The cathode material is the same as the material of the cathode 710, but the cathode material does not have the function of the cathode 720. It can be considered that the cathode material is a redundant structure generated by the process, so it is not shown in Figure 22.

[0209] FIG23 illustrates a schematic microstructure of the stacked layers from the anode to the cathode 710, located between the adjacent anodes 721 (or first anode) and 722 (or second anode) in FIG22 . As shown in FIG23 , between the anodes 721 and 722, the PDL 73 may be drop-shaped, and its slope angle a may be defined as follows: a tangent line L0 to the curved surface 73a of the PDL 73 is drawn through the intersection of the curved surface 73a and the top surface 72b of the anode, and the acute angle formed between the tangent line L0 and the top surface 72b is referred to as the slope angle a. Referring to FIG23 and FIG22 , in the manufacturing process of the display panel 7, after forming the isolation structure 740 on the PDL 73, the stacked layers from the hole functional layer 74 to the cathode 710 are sequentially formed (to highlight the key points, FIG23 shows only the cathode 710 of these stacked layers). Due to manufacturing process reasons, the top of isolation structure 740 can also be covered with cathode material 750. Therefore, when isolation structure 740 is prepared, a raised structure as shown in Figure 23 is formed. This raised structure can be geometrically described as follows: there exists a line connecting a point on cathode material 750 and a point on cathode 710, and the acute angle formed between this line and top surface 72b is greater than or equal to slope angle a. For example, there exists a line L3, and the acute angle d formed between line L3 and top surface 72b is greater than slope angle a. Alternatively, there exists a line L4 parallel to tangent line L0, and the acute angle e formed between line L4 and top surface 72b is equal to slope angle a.

[0210] In this embodiment, the isolation structure 740 can partially disconnect the organic connection layer 76 by physically isolating it, thereby separating the sub-pixels of different colors in the display panel 7, thereby reducing lateral crosstalk. The simultaneous provision of the isolation structure 740 and the organic connection layer 76 with high lateral resistance can enhance this effect, thereby preventing lateral crosstalk.

[0211] FIG24 illustrates a partial cross-sectional view of the display panel 7 in another embodiment of Example 7. Unlike FIG22 , the isolation structure 740 shown in FIG24 can be a groove. The groove extends upward through the hole functional layer 74, multiple light-emitting layers, multiple organic connection layers 76, electronic functional layer 79, cathode 710, and CPL 720, and downward to a certain depth of the PDL 73. The side of the PDL 73 facing the substrate 70 serves as the bottom wall 73b of the groove. During the manufacturing process of the display panel 7, after the groove is formed on the PDL 73, the stack from the hole functional layer 74 to the cathode 710 is sequentially formed. Due to manufacturing process reasons, the bottom wall 73b of the groove can also be covered with cathode material. This cathode material does not function as the cathode 720, but cathode material cannot be deposited on the sidewalls of the groove. A portion 730a of the encapsulation layer 730 can be filled into the groove and cover the cathode material and the PDL 73. Similarly, the isolation structure 740 makes the hole functional layer 74, the organic connecting layer 76, the cathode 710 and the CPL 720 no longer a continuous and complete whole-surface structure, but partially disconnected; the isolation structure 740 also makes the adjacent light-emitting units in each light-emitting layer (for example, the light-emitting unit 751 and the light-emitting unit 752 in the light-emitting layer 75, the light-emitting unit 781 and the light-emitting unit 782 in the light-emitting layer 78, etc.) separated in some lateral directions. It can be considered that the isolation structure 740 causes each light-emitting layer to be partially disconnected.

[0212] FIG25 illustrates a schematic microstructure of the stacked layers from the anode to the cathode 710, located between adjacent anodes 721 and 722 in FIG24 (to emphasize the key points, FIG23 shows only the cathode 710 of these stacked layers). As shown in FIG25 , between the anodes 721 and 722, the PDL 73 can be drop-shaped, and its slope angle a can be defined as follows: a tangent line L0 to the curved surface 73a of the PDL 73 is drawn through the intersection of the curved surface 73a of the PDL 73 and the top surface 72b of the anode. The acute angle formed by the tangent line L0 and the top surface 72b is called the slope angle a. When preparing the isolation structure 740, the groove structure shown in FIG25 is formed. This groove structure can be described by the following geometric relationship: there is a line connecting a point on the cathode material 750 and a point on the cathode 710, and the acute angle formed by this line and the top surface 72b is greater than or equal to the slope angle a. For example, there is a line L5, and the acute angle f formed between the line L5 and the top surface 72b is greater than the slope angle a. Alternatively, there is a line L6 parallel to the tangent line L0, and the acute angle g formed between the line L6 and the top surface 72b is equal to the slope angle a.

[0213] In this embodiment, the isolation structure 740 can partially disconnect the organic connection layer 76 by physically isolating it, thereby separating the sub-pixels of different colors in the display panel 7, thereby reducing lateral crosstalk. The simultaneous provision of the isolation structure 740 and the high lateral resistance organic connection layer 76 can enhance this effect, thereby preventing lateral crosstalk.

[0214] In this embodiment, as shown in Figures 22 and 24, along the x-axis direction, the isolation structure 740 can be located between the adjacent anodes 721 and anode 722, which is merely a schematic diagram. In fact, an isolation structure 740 can be provided between any two adjacent anodes in a portion of the anodes (this portion of the anodes is only a portion of all the anodes, and this portion of the anodes can be arranged together or dispersed). Alternatively, an isolation structure 740 can be provided between any two adjacent anodes in all the anodes in the display panel 7. In this embodiment, such two anodes can be referred to as the first anode and the second anode, respectively, and the isolation structure 740 is located between the first anode and the second anode. It is easy to understand from the above that the number of the first anode and the second anode can be greater than or equal to 1. In this embodiment, there can be one isolation structure 740 between the first anode and the second anode, or there can be multiple isolation structures 740 arranged side by side.

[0215] Alternatively, as shown in Figures 22 and 24, the isolation structure 740 can be located between adjacent sub-pixels to separate them. A sub-pixel can be defined as the entire stacked structure from a TFT to a portion of the CPL 720 corresponding to the TFT. For example, the sub-pixel on the left side of Figure 22 is the entire stacked structure from TFT 711 to a portion of the CPL 720 corresponding to the TFT, including TFT 711, anode 721, a portion of the hole functional layer 74, light-emitting unit 751, a portion of the organic connection layer 76, light-emitting unit 771, a portion of the organic connection layer 76, ..., light-emitting unit 781, a portion of the electronic functional layer 79, a portion of the cathode 710, and a portion of the CPL 720.

[0216] In this embodiment, an isolation structure 740 may be provided between any two adjacent sub-pixels in a portion of sub-pixels (this portion of sub-pixels is only a portion of all sub-pixels, and this portion of sub-pixels may be arranged together or dispersedly). Alternatively, an isolation structure 740 may be provided between any two adjacent sub-pixels in all sub-pixels in the display panel 7. In this embodiment, such two sub-pixels may be referred to as the first sub-pixel and the second sub-pixel, respectively, and the isolation structure 740 is located between the first sub-pixel and the second sub-pixel, and separates the first sub-pixel from the second sub-pixel. It is easy to understand from the above that the number of the first sub-pixel and the second sub-pixel may be greater than or equal to 1. In this embodiment, there may be one isolation structure 740 between the first sub-pixel and the second sub-pixel, or there may be multiple isolation structures 740 arranged side by side.

[0217] In this embodiment, when the isolation structures 740 are provided only between some sub-pixels, the display panel 7 has fewer isolation structures 740. This can reduce damage to the cathode 710 (for example, by 2 / 3), lower the power consumption of the display panel 7, and ensure the display quality of the display panel 7. Furthermore, it is easier to avoid directions and locations where bending reliability is poor, significantly improving the reliability of the display panel 7.

[0218] In this embodiment, the isolation structures 740 in the display panel 7 may all be columnar structures, or all be grooves, or a portion of the isolation structures 740 may be columnar structures and another portion of the isolation structures 740 may be grooves.

[0219] In this embodiment, a flat structure can be formed in the area without the isolation structure 740, and the geometric description described above applies to this flat structure. A partitioned structure can be formed in the area with the isolation structure 740, and the geometric description of the raised structure described above applies to this partitioned structure. Therefore, it can be considered that the solution of Example 7 adopts a semi-flat structure + semi-partitioned structure.

[0220] In this embodiment, the isolation structure 740 can be located between the red sub-pixel and the green sub-pixel, and the isolation structure 740 separates the red sub-pixel from the green sub-pixel; and / or, the isolation structure 740 can be located between the red sub-pixel and the blue sub-pixel, and the isolation structure 740 separates the red sub-pixel from the blue sub-pixel; and / or, the isolation structure 740 can be located between the green sub-pixel and the blue sub-pixel, and the isolation structure 740 separates the green sub-pixel from the blue sub-pixel.

[0221] The design for improving lateral crosstalk in this embodiment can be applied to various pixel arrangements, as listed below.

[0222] Figures 26-31 are schematic diagrams illustrating the application of the lateral crosstalk improvement design of this embodiment to a 2B-in-1 arrangement within a real red, green, and blue (Real RGB) array. The ratio of physical pixels to real pixels in the Real RGB array is 1:1. In a 2B-in-1 arrangement, two blue sub-pixels are vapor-deposited within a single FMM aperture, with a small spacing d1 between them. "Red," "Green," and "Blue" represent red, green, and blue sub-pixels, respectively.

[0223] As shown in FIG26 , schematically, the isolation structure 740 is only provided between the green sub-pixel and the red sub-pixel, and only isolates a portion of adjacent green sub-pixels and red sub-pixels, not all adjacent green sub-pixels and red sub-pixels.

[0224] Different from FIG. 26 , as shown in FIG. 27 , schematically, the isolation structure 740 may be provided between all adjacent green sub-pixels and red sub-pixels.

[0225] Different from that shown in FIG26 , as shown in FIG28 , schematically, the isolation structure 740 is only provided between the red sub-pixel and the blue sub-pixel, and only isolates a portion of adjacent red sub-pixels and blue sub-pixels, not all adjacent red sub-pixels and blue sub-pixels.

[0226] Different from what is shown in FIG. 28 , as shown in FIG. 29 , schematically, the isolation structure 740 can be basically provided between all adjacent red sub-pixels and blue sub-pixels.

[0227] Different from that shown in FIG26 , as shown in FIG30 , schematically, the isolation structure 740 is only provided between the green sub-pixel and the blue sub-pixel, and only isolates a portion of adjacent green sub-pixels and blue sub-pixels, not all adjacent green sub-pixels and blue sub-pixels.

[0228] Different from what is shown in FIG30 , as shown in FIG31 , schematically, the isolation structure 740 can be provided between all adjacent green sub-pixels and blue sub-pixels.

[0229] Figures 32-37 are schematic diagrams illustrating the application of the lateral crosstalk improvement design of this embodiment to a 1B-in-1 arrangement within a Real RGB pixel array. In this 1B-in-1 arrangement, one blue sub-pixel is vapor-deposited within one FMM aperture, and the spacing d2 between two adjacent blue sub-pixels is relatively large.

[0230] As shown in FIG32 , schematically, the isolation structure 740 is only provided between the green sub-pixel and the red sub-pixel, and only isolates a portion of adjacent green sub-pixels and red sub-pixels, not all adjacent green sub-pixels and red sub-pixels.

[0231] Different from what is shown in FIG32 , as shown in FIG33 , schematically, the isolation structure 740 can be provided between all adjacent green sub-pixels and red sub-pixels.

[0232] Different from that shown in FIG32 , as shown in FIG34 , schematically, the isolation structure 740 is only provided between the red sub-pixel and the blue sub-pixel, and only isolates a portion of adjacent red sub-pixels and blue sub-pixels, not all adjacent red sub-pixels and blue sub-pixels.

[0233] Different from what is shown in FIG34 , as shown in FIG35 , schematically, the isolation structure 740 can be provided between all adjacent red sub-pixels and blue sub-pixels.

[0234] Different from that shown in FIG32 , as shown in FIG36 , schematically, the isolation structure 740 is only provided between the green sub-pixel and the blue sub-pixel, and only isolates a portion of adjacent green sub-pixels and blue sub-pixels, not all adjacent green sub-pixels and blue sub-pixels.

[0235] Different from that shown in FIG36 , as shown in FIG37 , schematically, the isolation structure 740 can be provided between all adjacent green sub-pixels and blue sub-pixels.

[0236] 38 to 43 are schematic diagrams showing the application of the design for improving lateral crosstalk in a diamond arrangement according to this embodiment, wherein only a portion of the isolation structure 740 is shown for clarity.

[0237] As shown in FIG38 , schematically, the isolation structure 740 is only provided between the red sub-pixel and the green sub-pixel, and only isolates a portion of adjacent red sub-pixels and green sub-pixels, not all adjacent red sub-pixels and green sub-pixels.

[0238] Different from that shown in FIG38 , as shown in FIG39 , schematically, the isolation structure 740 can be provided between all adjacent red sub-pixels and green sub-pixels.

[0239] Different from that shown in FIG38 , as shown in FIG40 , schematically, the isolation structure 740 is only provided between the red sub-pixel and the blue sub-pixel, and only separates a portion of adjacent red sub-pixels and blue sub-pixels, not all adjacent red sub-pixels and blue sub-pixels.

[0240] Different from what is shown in FIG. 40 , as shown in FIG. 41 , schematically, the isolation structure 740 may be provided between all adjacent red sub-pixels and blue sub-pixels.

[0241] Different from that shown in FIG38 , as shown in FIG42 , schematically, the isolation structure 740 is only provided between the green sub-pixel and the blue sub-pixel, and only isolates a portion of adjacent green sub-pixels and blue sub-pixels, not all adjacent green sub-pixels and blue sub-pixels.

[0242] Different from what is shown in FIG. 42 , as shown in FIG. 43 , schematically, the isolation structure 740 may be provided between all adjacent green sub-pixels and blue sub-pixels.

[0243] In addition to the above-mentioned pixel arrangements, the design for improving lateral crosstalk in this embodiment can also be applied to any other suitable pixel arrangements, including but not limited to Delta arrangement, Tripod arrangement, Pentile arrangement, Diamond-like arrangement, etc.

[0244] This embodiment does not limit the shape of the sub-pixel. For example, the sub-pixel can be a regular shape such as a rectangle, a rectangle with rounded corners, a circle, a triangle, or a polygon of any shape or a smooth irregular shape. It can also be divided into two or more discontinuous luminous blocks, each of which can be a rectangle, a rectangle with rounded corners, a circle, a triangle, a polygon of any shape or a smooth irregular shape.

[0245] The pixel arrangement and sub-pixel shape described in the seventh embodiment are applicable to any embodiment of the present application.

[0246] In addition to being applied to the above-mentioned pixel arrangement, the improved lateral crosstalk design of this embodiment can also be applied to semi-flat and semi-partitioned Tandem OLEDs with different partition structure designs, wherein: the isolation column between two sub-pixels (or on the PDL Gap) can be single (can be called a single column), or two (can be called double columns) or more than two (can be called multiple columns); the isolation groove can be single (can be called a single groove), or two (can be called double grooves) or more than two (can be called multiple grooves); the cross-sectional shape of the isolation column or isolation groove can be a rectangle, a regular trapezoid, an inverted trapezoid, or other regular or irregular geometric shapes; the shape, height or depth, width and other structural dimensions of different isolation structures on the same PDLGap (or between the same pair of sub-pixels) can be the same or different.

[0247] Different from the seventh embodiment, the display panel 8 of the eighth embodiment can be colored by using white light + color filter film. Figures 44 to 47 are partial cross-sectional structural diagrams of the display panel 8 in different implementations of the eighth embodiment.

[0248] As shown in Figures 44 and 45, the display panel 8 may include a substrate 80, TFTs 811, 812, and 813, anodes 821, 822, and 823, a PDL 83, a hole functional layer 84, a light-emitting layer 85, an organic connection layer 86, a light-emitting layer 87, an electronic functional layer 88, a cathode 89, a CPL 810, an encapsulation layer 820, a first color filter 830, and an isolation structure 840. The isolation structure 840 in Figure 44 is a columnar structure, while the isolation structure 840 in Figure 45 is a groove. A portion 820a of the encapsulation layer 820 may be filled into the groove and cover the PDL 83.

[0249] Similar to the seventh embodiment, the display panel 8 of the eighth embodiment also adopts a semi-flat structure + a semi-isolated structure + a high-resistance organic connection layer 86 , wherein the isolation structure separates sub-pixels of different colors in the display panel 8 .

[0250] Unlike the seventh embodiment, as shown in Figures 44 and 45, the light-emitting layer 85 and the light-emitting layer 87 are both laterally continuous organic material layers. Instead of using the FMM process, the CMM process can be used, and the deposition of the light-emitting layer 85 or the light-emitting layer 87 can be completed by a single evaporation. The light-emitting layer 85 and the light-emitting layer 87 can respectively emit light of different colors, and the light from the light-emitting layer 85 and the light-emitting layer 87 can be mixed to produce white light. Schematically, the light-emitting layer 85 can include a red light-emitting unit (R) and a green light-emitting unit (G). The red light emitted by the red light-emitting unit (R) and the green light emitted by the green light-emitting unit (G) can be mixed to produce yellow light, so the light-emitting layer 85 can emit yellow light. Schematically, the light-emitting layer 87 can include a blue light-emitting unit (B), and the light-emitting layer 87 can emit blue light. The yellow light emitted by the light-emitting layer 85 can be mixed with the blue light emitted by the light-emitting layer 87 to produce white light, and ultimately all the light-emitting layers as a whole emit white light.

[0251] As shown in Figures 44 and 45, a first color filter film 830 can be formed on the encapsulation layer 820. The first color filter film 830 can include a plurality of first red light filter units 831, a plurality of first green light filter units 832, and a plurality of first blue light filter units 833. The first red light filter units 831, the first green light filter units 832, and the first blue light filter units 833 can be arranged in a regular array. It will be understood that the first red light filter units 831, the first green light filter units 832, and the first blue light filter units 833 are arranged sequentially along the x-axis. This is merely an example. In practice, the arrangement of the filter units can be determined according to the pixel arrangement, and is not limited in the eighth embodiment.

[0252] Referring to Figures 44 and 45, the white light emitted by the entire light-emitting layer can be transmitted upward and enter the first red light filtering unit 831, the first green light filtering unit 832 and the first blue light filtering unit 833 respectively. The first red light filtering unit 831 filters the white light and emits red light, the first green light filtering unit 832 filters the white light and emits green light, and the first blue light filtering unit 833 filters the white light and emits blue light, thereby realizing color display of the display panel 8.

[0253] The display panel 8 of the eighth embodiment may adopt a top-emission architecture, where light is transmitted upward and emitted from the first color filter 830 above the encapsulation layer 820. In other embodiments, the display panel 8 may adopt a bottom-emission architecture, where the first color filter 830 is located below the substrate 80 (i.e., on the side of the substrate 80 facing away from the light-emitting layer), and light is transmitted downward and emitted from the first color filter 830 below the substrate 80.

[0254] The eighth embodiment uses white light + color filter film to achieve colorization, which is beneficial to improving the PPI of the display panel. The display panel 8 of the eighth embodiment can be applied to electronic devices such as silicon-based OLED TVs or OLED TVs.

[0255] In other embodiments, other white light OLED device structures may be used as needed to achieve colorization using white light + color filter film.

[0256] For example, in Example 9, as shown in FIG44 or FIG45 , light-emitting layer 85 can include a blue light-emitting unit (B), and light-emitting layer 85 can emit blue light. Light-emitting layer 87 can include a red light-emitting unit (R) and a green light-emitting unit (G), and light-emitting layer 87 can emit yellow light. The blue light emitted by light-emitting layer 85 can be mixed with the yellow light emitted by light-emitting layer 87 to form white light. Ultimately, all light-emitting layers as a whole emit white light.

[0257] Alternatively, in Example 10, a red light-emitting layer, a green light-emitting layer, and a blue light-emitting layer may be provided separately, with the three light-emitting layers stacked (not limited to stacked in sequence), and any two light-emitting layers are connected in series via an organic connecting layer. The red light emitted by the red light-emitting layer, the green light emitted by the green light-emitting layer, and the blue light emitted by the blue light-emitting layer mix to form white light, and ultimately all the light-emitting layers as a whole emit white light.

[0258] Alternatively, in the eleventh embodiment shown in FIG. 46 and FIG. 47 , two light-emitting layers emitting blue light and one light-emitting layer emitting yellow light may be provided, and white light may be generated by mixing the blue light and the yellow light.

[0259] As shown in Figures 46 and 47, the display panel 9 of the eleventh embodiment may include a substrate 90, TFTs 911, 912, and 913, anodes 921, 922, and 923, a PDL 93, a hole functional layer 94, a light-emitting layer 95, an organic connection layer 96, a light-emitting layer 97, an organic connection layer 96, a light-emitting layer 98, an electronic functional layer 99, a cathode 910, a CPL 920, an encapsulation layer 930, a first color filter 940, and an isolation structure 950. The isolation structure 950 in Figure 46 is a columnar structure, while the isolation structure 950 in Figure 47 is a groove. A portion 930a of the encapsulation layer 930 may be filled into the groove and cover the PDL 93. The first color filter 940 may include a plurality of first red light filter units 941, a plurality of first green light filter units 942, and a plurality of first blue light filter units 943.

[0260] As shown in Figures 46 and 47, the light-emitting layer 95 may include a blue light-emitting unit (B), and the light-emitting layer 95 may emit blue light. The light-emitting layer 97 may include a red light-emitting unit (R) and a green light-emitting unit (G), and the light-emitting layer 97 may emit yellow light. The light-emitting layer 98 may include a blue light-emitting unit (B), and the light-emitting layer 98 may emit blue light. Ultimately, all the light-emitting layers as a whole emit white light. It is understood that the arrangement order of light-emitting layer 95-light-emitting layer 97-light-emitting layer 98 is only an example. In fact, the arrangement order of each light-emitting layer can be set as needed, and is not limited in Example 11.

[0261] In the Tandem OLED, since the organic light emitting layer has a low efficiency in emitting blue light, it is difficult to emit blue light. Therefore, in the eleventh embodiment, an additional light emitting layer emitting blue light is provided to improve the light extraction efficiency of blue light.

[0262] Alternatively, in another embodiment, a first light-emitting layer and a second light-emitting layer may be provided separately and stacked. The first light-emitting layer may include a red light-emitting unit (R) and emit red light; the second light-emitting layer may include a green light-emitting unit (G) and a blue light-emitting unit (B) and emit cyan light. Ultimately, all the light-emitting layers as a whole emit white light.

[0263] Alternatively, in another embodiment, a first light-emitting layer and a second light-emitting layer may be provided separately and stacked. The first light-emitting layer may include a green light-emitting unit (G) and emit green light; the second light-emitting layer may include a red light-emitting unit (R) and a blue light-emitting unit (B) and emit magenta light. Ultimately, all the light-emitting layers as a whole emit white light.

[0264] It is understood that the above examples only illustrate some white light OLED device structures. In the embodiments of the present application, different white light OLED device structures can be configured as needed. These white light OLED device structures meet the following design requirements: among the multiple light-emitting layers, at least two light-emitting layers can emit light of different colors, and the light emitted by all the light-emitting layers can be mixed to form white light, and ultimately all the light-emitting layers as a whole emit white light.

[0265] Different from the above embodiment that uses white light + color filter film to achieve colorization, the twelfth embodiment can use blue light + color conversion layer to achieve colorization.

[0266] Figures 48 and 49 illustrate partial cross-sectional views of a display panel 10 according to a twelfth embodiment. As shown in Figures 48 and 49, the display panel 10 may include a substrate 100, TFTs 101, 102, and 103, anodes 104, 105, and 106, a PDL 107, a hole functional layer 108, a light-emitting layer 109, an organic connection layer 112, a light-emitting layer 113, a light-emitting layer 114, an electron functional layer 115, a cathode 116, a cathode-like layer 117, an encapsulation layer 118, a color conversion layer 119, and an isolation structure 120. The isolation structure 120 in Figure 48 is a columnar structure, while the isolation structure 120 in Figure 49 is a groove. A portion 118a of the encapsulation layer 118 may be inserted into the groove and cover the PDL 107. The light-emitting layer 109, the light-emitting layer 113, and the light-emitting layer 114 are stacked in sequence, with adjacent light-emitting layers connected in series via an organic connection layer 112. The light-emitting layer 109 , the light-emitting layer 113 and the light-emitting layer 114 all include a blue light-emitting unit (B), and the light-emitting layer 109 , the light-emitting layer 113 and the light-emitting layer 114 can all emit blue light. Ultimately, all the light-emitting layers as a whole emit blue light.

[0267] As shown in Figures 48 and 49, a color conversion layer 119 can be formed on the encapsulation layer 118. The color conversion layer 119 can include multiple red light conversion units 119a, multiple green light conversion units 119b, and multiple blue light conversion units 119c. The red light conversion units 119a, green light conversion units 119b, and blue light conversion units 119c can be arranged in a regular array. It should be understood that the red light conversion units 119a, green light conversion units 119b, and blue light conversion units 119c are arranged sequentially along the x-axis. This is merely an example. In practice, the arrangement of the conversion units can be determined based on the pixel arrangement, and this is not limited in Example 12.

[0268] As shown in Figures 48 and 49, the blue light emitted by the entire light-emitting layer can be transmitted upward and enter the red light conversion unit 119a, the green light conversion unit 119b and the blue light conversion unit 119c respectively. The red light conversion unit 119a can convert the color of the blue light and emit red light, the green light conversion unit 119b can convert the color of the blue light and emit green light, and the blue light conversion unit 119c can narrow the spectrum of the blue light and emit purer blue light, thereby realizing color display of the display panel 10.

[0269] The display panel 10 of the twelfth embodiment may adopt a top-emission architecture, where light is transmitted upward and emitted from the color conversion layer 119 above the encapsulation layer 118. In other embodiments, the display panel 10 may adopt a bottom-emission architecture, where the color conversion layer 119 is located below the substrate 100 (i.e., on the side of the substrate 100 facing away from the light-emitting layer), and light is transmitted downward and emitted from the color conversion layer 119 below the substrate 100.

[0270] In the twelfth embodiment, illustratively, to ensure the purity of the light color of the display panel 10, a second color filter film may be further disposed outside the color conversion layer 119. The second color filter film may be located on the side of the color conversion layer 119 facing away from the encapsulation layer 118 (a top-emission architecture) or on the side of the color conversion layer 119 facing away from the substrate 100 (a bottom-emission architecture). The second color filter film may include a plurality of second red light filter units, a plurality of second green light filter units, and a plurality of second blue light filter units. The second red light filter units correspond to the red light conversion units and can filter the red light emitted by the red light conversion units and emit red light. The second green light filter units can filter the green light emitted by the green light conversion units and emit green light. The second blue light filter units can filter the blue light emitted by the blue light conversion units and emit blue light.

[0271] The twelfth embodiment uses a blue light + color conversion layer approach to achieve colorization, which simplifies the process, reduces voltage drop, lowers power consumption of the display panel, and improves the brightness of the display panel. The display panel 10 of the twelfth embodiment can be applied to electronic devices such as high-brightness televisions.

[0272] Different from the twelfth embodiment, in other embodiments, the color conversion layer may not have a blue light conversion unit, and the second color filter film may include a second blue light filter unit that filters the blue light emitted by the light-emitting layer.

[0273] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A display panel, characterized in that: It comprises a plurality of anodes, a pixel definition layer, a hole function layer, a plurality of light-emitting layers, at least one organic connection layer, an electronic function layer and a cathode, wherein any two adjacent anodes among the plurality of anodes are isolated by the pixel definition layer, the plurality of anodes, the hole function layer, the plurality of light-emitting layers, the electronic function layer and the cathode are stacked in sequence, and each of the organic connection layers is connected between two adjacent light-emitting layers; The material of each of the organic connection layers includes a main material and a doping material doped in the main material, and the square resistance of each of the organic connection layers in any lateral direction is greater than or equal to 1 GΩ / □, wherein any lateral direction is perpendicular to the thickness direction of the organic connection layer.

2. The display panel according to claim 1, characterized in that: The organic connection layer includes a charge generation layer, and the charge generation layer includes an N-type charge generation layer and a P-type charge generation layer; the P-type charge generation layer and the N-type charge generation layer are stacked and located on a side of the N-type charge generation layer facing the cathode.

3. The display panel according to claim 2, characterized in that: The main body material of the N-type charge generation layer includes an N-type main body material, the doping material of the N-type charge generation layer includes an N-type doping material, and the concentration of the N-type doping material ∈ (0%, 100%].

4. The display panel according to claim 3, characterized in that: The N-type main material includes organic aromatic materials, and / or, The N-type doping material includes a metal material with a work function of ≤3.5 eV, or a metal oxide material with a work function of ≤3.5 eV, or an organic material with a work function of ≤3.5 eV, or an organic-metal complex material with a work function of ≤3.5 eV.

5. The display panel according to any one of claims 2 to 4, characterized in that: The main material of the P-type charge generation layer includes a P-type main material, the doping material of the P-type charge generation layer includes a P-type doping material, and the concentration of the P-type doping material is ∈(0%, 100%).

6. The display panel according to claim 5, characterized in that: The P-type main material includes organic aromatic materials, and / or, The P-type doping material includes an organic material with a lowest unoccupied molecular orbital energy level of ≤-3.0 eV, or an inorganic material with a work function of ≥3.0 eV.

7. The display panel according to any one of claims 2 to 6, characterized in that: The charge generation layer further includes an intermediate layer connected between the N-type charge generation layer and the P-type charge generation layer.

8. The display panel according to any one of claims 2 to 7, characterized in that: The organic connection layer further comprises at least one of a hole blocking layer, an electron transport layer, a hole injection layer and a hole transport layer, wherein: The hole blocking layer, the N-type charge generation layer and the P-type charge generation layer are stacked in sequence; The electron transport layer, the N-type charge generation layer and the P-type charge generation layer are sequentially stacked, and when the hole blocking layer is present, the hole blocking layer, the electron transport layer and the N-type charge generation layer are sequentially stacked; The hole injection layer is stacked with the P-type charge generation layer and is located on a side of the P-type charge generation layer facing the cathode; The hole transport layer is stacked with the P-type charge generation layer and is located on the side of the P-type charge generation layer facing the cathode, and when the hole injection layer is present, the P-type charge generation layer, the hole injection layer and the hole transport layer are stacked in sequence.

9. The display panel according to any one of claims 1 to 8, characterized in that: The longitudinal mobility of the organic connecting layer is 10 -1 cm 2 / (V·S)~10 -6 cm 2 / (V·S).

10. The display panel according to any one of claims 1 to 9, characterized in that: The thickness of each organic connecting layer is less than or equal to 300 nm.

11. The display panel according to any one of claims 1 to 10, characterized in that: The plurality of anodes include a first anode and a second anode, the first anode is adjacent to the second anode, and the first anode has a top surface facing the cathode; The portion of the pixel definition layer located between the first anode and the second anode has a slope angle; The acute angle formed by a line connecting any two points on the surface of the cathode facing the pixel definition layer and the top surface is less than or equal to the slope angle; the acute angle formed by a line connecting any two points on the surface of the cathode facing away from the pixel definition layer and the top surface is less than or equal to the slope angle.

12. The display panel according to any one of claims 1 to 10, characterized in that: The display panel further includes an isolation structure, which is formed on the pixel definition layer and penetrates the hole functional layer, the plurality of light emitting layers, the at least one organic connection layer, the electronic functional layer and the cathode.

13. The display panel according to claim 12, characterized in that: The display panel includes a plurality of sub-pixels, a portion of the sub-pixels includes a first sub-pixel and a second sub-pixel. The first sub-pixel is adjacent to the second sub-pixel, and the isolation structure is located between the first sub-pixel and the second sub-pixel.

14. The display panel according to claim 12 or 13, characterized in that: The isolation structure includes a columnar structure.

15. The display panel according to any one of claims 12 to 14, characterized in that: The isolation structure comprises a groove, and a side of the pixel definition layer facing away from the cathode is a bottom wall of the groove.

16. The display panel according to any one of claims 1 to 15, characterized in that: The sub-pixels in the display panel form a true red, green and blue arrangement, a diamond arrangement, a delta arrangement, a tripod arrangement, a pentile arrangement or a diamond-like arrangement.

17. The display panel according to any one of claims 1 to 16, characterized in that: Each of the light-emitting layers includes a red light-emitting unit, a green light-emitting unit and a blue light-emitting unit.

18. The display panel according to any one of claims 1 to 16, characterized in that: The display panel includes a first color filter film, which includes a plurality of first red light filter units, a plurality of first green light filter units, and a plurality of first blue light filter units; the first color filter film is located on a side of the cathode facing away from the electronic functional layer, or the first color filter film is located on a side of the anodes facing away from the hole functional layer; At least two of the multiple light-emitting layers are used to emit light of different colors, respectively, and the multiple light-emitting layers as a whole emit white light; the first red light filtering unit is used to filter the white light and emit red light, the first green light filtering unit is used to filter the white light and emit green light, and the first blue light filtering unit is used to filter the white light and emit blue light.

19. The display panel according to any one of claims 1 to 16, characterized in that: The display panel comprises a color conversion layer, the color conversion layer comprises a plurality of red light conversion units and a plurality of green light conversion units, the color conversion layer is located on a side of the cathode facing away from the electron functional layer, or the color conversion layer is located on a side of the plurality of anodes facing away from the hole functional layer; Each of the plurality of light-emitting layers is used to emit blue light, the red light conversion unit is used to convert the color of the blue light and emit red light, and the green light conversion unit is used to convert the color of the blue light and emit green light.

20. The display panel according to claim 19, characterized in that: The display panel also includes a second color filter film, which is located on the side of the color conversion layer facing away from the cathode; the second color filter film includes a plurality of second red light filter units, a plurality of second green light filter units and a plurality of second blue light filter units, the second red light filter unit is used to filter the red light emitted by the red light conversion unit and emit red light, the second green light filter unit is used to filter the green light emitted by the green light conversion unit and emit green light, and the second blue light filter unit is used to filter the blue light and emit blue light.

21. The display panel according to any one of claims 1 to 20, characterized in that: The display panel further comprises a substrate, a plurality of thin film transistors, a covering layer and an encapsulation layer, wherein the plurality of thin film transistors are arranged on a side of the substrate facing the plurality of anodes, the plurality of thin film transistors are electrically connected to the plurality of anodes one-to-one, the covering layer is located on a side of the cathode facing away from the electronic functional layer, and the encapsulation layer is located on a side of the covering layer facing away from the cathode; wherein, The first color filter film is located on a side of the encapsulation layer facing away from the cover layer, or on a side of the substrate facing away from the plurality of thin film transistors; The color conversion layer is located on a side of the encapsulation layer facing away from the cover layer, or on a side of the substrate facing away from the plurality of thin film transistors; A portion of the encapsulation layer fills the groove and covers the pixel definition layer.

22. A display screen, characterized in that: It comprises a cover plate and the display panel according to any one of claims 1 to 21, wherein the cover plate is bonded to the display panel.

23. An electronic device, characterized in that: It comprises a structural member and the display screen according to claim 22, wherein the display screen is fixed to the structural member.

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