Series OLED display panel

Abstract

The utility model provides a series connection OLED display panel. The series connection OLED display panel comprises a substrate and a pixel layer arranged on one side of the substrate. The pixel layer comprises a pixel definition area and a sub light-emitting area; the pixel definition area is provided with an isolation barrier layer; the isolation barrier layer is of a trapezoid structure, the bottom edge of the trapezoid structure is close to the substrate, and the isolation barrier layer separates one charge generation layer in every two adjacent sub-light-emitting areas. The pixel definition area of the series OLED display panel is provided with the isolation barrier layer, leakage current between two adjacent light-emitting areas is prevented, further, different pixel arrangement structures are matched, the light-emitting areas with different colors are provided with the isolation barrier layers with different shapes, and the light-emitting areas with different colors are provided with the isolation barrier layers with different shapes. Therefore, the access between the charge generation layers of the light-emitting areas with different colors can be better blocked, and the problem of transverse crosstalk of the series OLED display panel can be improved.

Description

OLED display panels Technical Field

[0001] This utility model relates to the technical field of display panels, and more specifically, to a series OLED display panel. Background Technology

[0002] Organic light-emitting diodes (OLEDs) are current-driven light-emitting devices with advantages such as fast response, self-illumination, wide viewing angle, and a wide operating temperature range, making them widely used in high-performance display fields. In particular, the increasing demand for AMOLED screens in laptops and automotive applications has placed demands on OLED screens for long lifespan, high HDR, peak brightness exceeding 1000 nits, and a room-temperature lifespan (T80) greater than 10000 hours. To meet these requirements, tandem OLED display panels are gaining increasing market favor.

[0003] The key technology in tandem device structures is the charge generation layer (CGL), which provides electrons and holes for individual light-emitting elements. The charge generation layer typically consists of an N-type doped layer (N-CGL) and a P-type doped layer (P-CGL), used to generate electrons and holes, respectively. Therefore, the charge generation layer must have a low work function to achieve low operating voltage and less power consumption, and good LUMO / HUMO energy level matching with the adjacent charge transport layer to prevent charge accumulation in the charge generation layer from causing voltage drop at the PN junction. However, because the charge generation layer has high conductivity, it is prone to lateral leakage current (crosstalk) under the influence of an electric field, making it difficult for AMOLEDs to meet customer requirements for low grayscale brightness.

[0004] It should be noted that the information in the background section of the present invention is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] To address the problems in the prior art, the purpose of this utility model is to provide a series OLED display panel that improves the problem of lateral crosstalk by setting an isolation barrier layer in the pixel definition area between two adjacent light-emitting areas to block the path between the charge generation layers of adjacent light-emitting areas.

[0006] An embodiment of this utility model provides a tandem OLED display panel, including a substrate and a pixel layer disposed on one side of the substrate;

[0007] The pixel layer includes a pixel definition region and a sub-light emission region;

[0008] The pixel definition area is provided with an isolation barrier layer;

[0009] The isolation barrier layer has a trapezoidal structure with its base close to the substrate, and the isolation barrier layer separates a charge generation layer in two adjacent sub-light-emitting regions.

[0010] According to some examples of the present invention, the tandem OLED display panel further includes a pixel driving circuit layer disposed between the substrate and the pixel layer;

[0011] The pixel driving circuit layer includes multiple pixel driving circuit units, and each pixel driving circuit unit includes three sub-driving circuits.

[0012] The sub-light-emitting region is a blue sub-light-emitting region, a red sub-light-emitting region, or a green sub-light-emitting region, and a blue sub-light-emitting region, a red sub-light-emitting region, and a green sub-light-emitting region constitute a pixel.

[0013] Each of the pixel driving circuit units has a sub-driving circuit corresponding to a sub-emitting region of a certain color and is configured to drive the sub-emitting region of that color to emit light.

[0014] According to some examples of the present invention, the isolation barrier layer includes a first isolation barrier layer and a second isolation barrier layer;

[0015] The first isolation barrier layer is disposed in the pixel definition area corresponding to the blue sub-light emission area;

[0016] The second isolation barrier layer is disposed in the pixel definition area corresponding to the red sub-light emission area and / or the pixel definition area corresponding to the green sub-light emission area.

[0017] According to some examples of this utility model, each of the pixels is quadrilateral;

[0018] The blue sub-light-emitting areas of multiple pixels are in the same row, and the red and green sub-light-emitting areas of multiple pixels are in an adjacent row, with the red and green sub-light-emitting areas arranged alternately.

[0019] The first isolation barrier layer is disposed in the direction of row extension;

[0020] The second isolation barrier layer is disposed in the vertical direction of the row extension.

[0021] According to some examples of this utility model, the first isolation barrier layer is in the shape of a strip, a C-shape, or a bracket shape;

[0022] The second isolation barrier layer is elongated.

[0023] According to some examples of this utility model, each of the sub-light-emitting regions includes:

[0024] First electrode layer;

[0025] At least two light-emitting structure layers are stacked on the first electrode layer. Each light-emitting structure layer includes a first carrier transport layer, a light-emitting layer, and a second carrier transport layer. The light-emitting layer is disposed between adjacent first carrier transport layers and second carrier transport layers.

[0026] At least one charge generation layer, each charge generation layer being disposed between two adjacent light-emitting structure layers, the charge generation layer comprising a second carrier generation layer, an intermediate layer and a first carrier generation layer stacked sequentially;

[0027] The second electrode layer is disposed on the side of at least two of the light-emitting structural layers opposite to the first electrode layer;

[0028] The top of the isolation barrier layer is higher than the top of the charge generation layer closest to the second electrode layer.

[0029] According to some examples of the present invention, the top of the isolation barrier layer is between the bottom and top of the first carrier transport layer of the light-emitting structure layer closest to the second electrode layer.

[0030] According to some examples of the present invention, the isolation barrier layer includes one or more layers of aromatic amine compound layer, azine compound layer, and triazine compound layer.

[0031] According to some examples of this invention, the refractive index of the isolation barrier layer is between 1.6 and 1.8.

[0032] The pixel definition area of ​​the series OLED display panel of this invention is provided with an isolation barrier layer to prevent leakage current between two adjacent light-emitting areas. Furthermore, in conjunction with different pixel arrangement structures, different shapes of isolation barrier layers are provided for light-emitting areas of different colors, thereby better blocking the path between the charge generation layers of light-emitting areas of different colors, thus improving the problem of lateral crosstalk in series OLED display panels. Attached Figure Description

[0033] The above and other features and advantages of this application will become more apparent from a detailed description of exemplary embodiments thereof with reference to the accompanying drawings.

[0034] Figure 1 is a schematic diagram of the structure of a series OLED display panel according to an embodiment of the present invention;

[0035] Figure 2 is a top view of a tandem OLED display panel according to an embodiment of the present invention; and

[0036] Figure 3 is a top view of a tandem OLED display panel according to another embodiment of the present invention. Detailed Implementation

[0037] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed herein. This utility model can also be implemented or applied through other different specific embodiments. Various details in this utility model can also be modified or changed according to different viewpoints and application systems without departing from the spirit of this utility model. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this utility model can be combined with each other.

[0038] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings, so that those skilled in the art can easily implement it. This utility model can be embodied in many different forms and is not limited to the embodiments described herein.

[0039] In the representation of this utility model, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics represented in connection with that embodiment or example, which are included in at least one embodiment or example of this utility model. Furthermore, the specific features, structures, materials, or characteristics represented may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate different embodiments or examples represented in this utility model, as well as features of different embodiments or examples.

[0040] Furthermore, the terms "first" and "second" are used for illustrative purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the representation of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0041] To clearly illustrate this utility model, components unrelated to the description are omitted, and the same or similar constituent elements throughout the specification are given the same reference numerals.

[0042] Throughout this specification, when it is said that a device is "connected" to another device, this includes not only "direct connection" but also "indirect connection" by placing other components in between. Furthermore, when it is said that a device "comprises" a certain constituent element, unless otherwise stated otherwise, this does not exclude other constituent elements, but rather implies that other constituent elements may be included.

[0043] When we say that a device is "above" another device, this can mean that it is directly above the other device, or it can mean that other devices are present in between. Conversely, when we say that a device is "directly" "above" another device, there are no other devices present in between.

[0044] Although the terms first, second, etc., are used in some instances herein to refer to various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, first interface and second interface, etc., are used. Furthermore, as used herein, the singular forms “a,” “an,” and “the” are intended to also include the plural forms unless the context indicates otherwise. It should be further understood that the terms “comprising,” “including,” indicate the presence of features, steps, operations, elements, components, items, kinds, and / or groups, but do not exclude the presence, occurrence, or addition of one or more other features, steps, operations, elements, components, items, kinds, and / or groups. The terms “or” and “and / or” as used herein are interpreted as inclusive, or mean any one or any combination thereof. Thus, “A, B, or C” or “A, B, and / or C” means “any one of: A; B; C; A and B; A and C; B and C; A, B, and C.” Exceptions to this definition will only occur if the combination of elements, functions, steps, or operations is inherently mutually exclusive in some way.

[0045] The technical terms used herein are for reference only to specific embodiments and are not intended to limit the scope of the invention. The singular form used herein includes the plural form unless the statement explicitly indicates otherwise. The word "comprising" as used in this specification means to specify a particular characteristic, region, integer, step, operation, element, and / or component, and does not exclude the presence or addition of other characteristics, regions, integers, steps, operations, elements, and / or components.

[0046] Although not explicitly defined, all terms, including technical and scientific terms used herein, shall have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries shall be further interpreted as having a meaning consistent with relevant technical documents and the content of this present instruction, and shall not be over-interpreted as having an ideal or overly formulaic meaning unless otherwise defined.

[0047] The structure of the tandem OLED display panel of this utility model is further described below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments are not intended to limit the scope of protection of this utility model.

[0048] Figure 1 is a schematic diagram of the structure of a tandem OLED display panel according to an embodiment of the present invention. Specifically, the tandem OLED display panel includes a substrate 9 and a pixel layer disposed on one side of the substrate 9 (the light-emitting side, in the direction of the arrow in Figure 1). As an example, the substrate 9 can be composed of semiconductor materials, insulating materials, conductive materials, or any combination thereof. The substrate 9 can be a single-layer structure or a multi-layer structure. For example, the substrate 9 can be a silicon (Si) substrate, a silicon-germanium (SiGe) substrate, a silicon-germanium-carbon (SiGeC) substrate, a silicon carbide (SiC) substrate, a gallium arsenide (GaAs) substrate, an indium arsenide (InAs) substrate, an indium phosphide (InP) substrate, or other III / V semiconductor substrates or II / VI semiconductor substrates. Alternatively, for example, the substrate 9 can be a layered substrate including, for example, a stack of Si and SiGe, a stack of Si and SiC, silicon-on-insulator (SOI), or silicon-germanium-on-insulator.

[0049] The pixel layer includes a pixel definition region F and a sub-light emission region E, that is, the pixel definition layer 1 separates adjacent sub-light emission regions E. An isolation barrier layer 3 is provided in the pixel definition region F; the isolation barrier layer 3 has a trapezoidal structure, specifically, the cross-section of the isolation barrier layer 3 along the thickness direction of the display panel is a trapezoidal structure, and the bottom edge of the trapezoidal structure is close to the substrate 9.

[0050] An isolation barrier layer 3 separates a charge-generating layer in two adjacent sub-emitting regions E. For example, the sub-emitting regions E of a series-connected OLED display panel include:

[0051] First electrode layer;

[0052] At least two light-emitting structure layers are stacked on the first electrode layer. Each light-emitting structure layer includes a first carrier transport layer, a light-emitting layer, and a second carrier transport layer. The light-emitting layer is disposed between adjacent first carrier transport layers and second carrier transport layers.

[0053] At least one charge generation layer, each charge generation layer being disposed between two adjacent light-emitting structural layers, the charge generation layer comprising a second carrier generation layer, an intermediate layer and a first carrier generation layer stacked sequentially; it can be understood that the above "at least two light-emitting structural layers" means that the number of light-emitting structural layers in the OLED display panel connected in series is N, and N≥2, and the number of charge generation layers is N-1.

[0054] The second electrode layer is disposed on the side of at least two light-emitting structural layers facing away from the first electrode layer.

[0055] When the first electrode layer and the second electrode layer are respectively the anode layer and the cathode layer, the first charge carrier is a hole and the second charge carrier is an electron; when the first electrode layer and the second electrode layer are respectively the cathode layer and the anode layer, the first charge carrier is an electron and the second charge carrier is a hole.

[0056] Taking the tandem OLED display panel of the embodiment in Figure 1 as an example, its first electrode layer and second electrode layer are an anode layer 21 and a cathode layer 24, respectively, including two light-emitting structure layers and a charge-generating layer 23. The light-emitting structure layer near the substrate 9 includes a hole injection layer / hole transport layer 221, an organic light-emitting material layer 222, and an electron transport layer / electron injection layer 223 stacked on the anode layer 21. The light-emitting structure layer away from the substrate 9 includes a hole injection layer / hole transport layer 221', an organic light-emitting material layer 222', and an electron transport layer / electron injection layer 223' stacked on the charge-generating layer 23.

[0057] In the above embodiments, the isolation barrier layer 3 serves to separate a charge generation layer in two adjacent sub-light-emitting regions E, so the top of the isolation barrier layer 3 should be higher than the top of the charge generation layer 23. When the tandem OLED display panel includes three or more light-emitting structure layers, the top of the isolation barrier layer 3 should be higher than the top of the charge generation layer closest to the second electrode layer. Preferably, the top of the isolation barrier layer is between the bottom and top of the first carrier transport layer of the light-emitting structure layer closest to the second electrode layer.

[0058] Accordingly, the isolation barrier layer 3 can be obtained by sequentially depositing a light-emitting structure layer on the substrate up to the charge generation layer of the light-emitting structure layer closest to the second electrode layer, or by depositing the first carrier transport layer closest to the second electrode layer on the substrate. The isolation barrier layer 3 can be obtained by first patterning the corresponding grooves, and then depositing the material of the isolation barrier layer in the grooves through evaporation or inkjet deposition processes. In practice, the depth of the grooves can be between 1.5 and 1.7 micrometers, and the width of the grooves can be between 3 and 4 micrometers. The thickness of the isolation barrier layer filling the grooves can be less than the depth of the grooves, such as the thickness of the isolation barrier layer being between 1.2 and 1.4 micrometers.

[0059] The isolation barrier layer can be one or more layers selected from aromatic amine compound layers, azine compound layers, and triazine compound layers; that is, the isolation barrier layer can be a single-layer structure or a multi-layer structure. Preferably, the refractive index of the isolation barrier layer is between 1.6 and 1.8.

[0060] The pixel definition area of ​​the tandem OLED display panel of this invention is provided with an isolation barrier layer, which causes the charge generation layer CGL layer to break at the isolation barrier layer. At the same time, the isolation barrier layer keeps the hole injection layer / hole transport layer 221', organic light-emitting material layer 222', electron transport layer / electron injection layer 223' and the second electrode layer continuous, thereby ensuring that the resistance of the display panel will not increase due to the discontinuity of the second electrode layer. This avoids the problems of increased resistance and subsequent increased power consumption and large current voltage drop caused by the discontinuity of the cathode layer in large-size display panels, which would affect the light-emitting performance of the tandem OLED display panel.

[0061] The tandem OLED display panel also includes a pixel driving circuit layer disposed between the substrate and the pixel layer. The pixel driving circuit layer includes multiple pixel driving circuit units, and each pixel driving circuit unit includes three sub-driving circuits 8 (elliptical dashed box). The sub-emitting regions are a blue sub-emitting region B, a red sub-emitting region R, or a green sub-emitting region G, and a blue sub-emitting region B, a red sub-emitting region R, and a green sub-emitting region G constitute a pixel. Each sub-driving circuit 8 of each pixel driving circuit unit corresponds to a sub-emitting region of a certain color and is configured to drive the sub-emitting region of that color to emit light. The isolation barrier layer includes a first isolation barrier layer and a second isolation barrier layer.

[0062] Figure 2 is a top view of a series OLED display panel according to an embodiment of the present invention. The blue sub-light-emitting region B, the red sub-light-emitting region R, and the green sub-light-emitting region G are all quadrilaterals. Multiple pixels of the blue sub-light-emitting region B are in the same row, and multiple pixels of the red sub-light-emitting region R and the green sub-light-emitting region G are in an adjacent row, with the red sub-light-emitting region R and the green sub-light-emitting region G arranged alternately. At this time, the pixel including a blue sub-light-emitting region B, a red sub-light-emitting region R, and a green sub-light-emitting region G is also quadrilateral.

[0063] In one embodiment shown in Figure 2, the first isolation barrier layer 3B is disposed in the pixel definition area corresponding to the blue sub-light emission area B, and the second isolation barrier layer 3RG is disposed in the pixel definition area corresponding to the red sub-light emission area R and / or the pixel definition area corresponding to the green sub-light emission area G.

[0064] It should be noted that when no isolation barrier layer is set, the charge generation layer is deposited entirely on top of the pixel definition layer 1. Under the action of an external electric field, leakage current will pass through the charge generation layer. Especially at low brightness, since the driving voltage of the blue sub-light-emitting area is higher than that of the red and green sub-light-emitting areas, the leakage current when the blue sub-light-emitting area emits light may drive the red and green sub-light-emitting areas to emit light, resulting in low color purity at low brightness, a reddish or greenish tint in the display, and poor display panel quality.

[0065] The first isolation barrier layer 3B can be elongated, C-shaped, or bracket-shaped. To better block the highly conductive charge-generating layer of the blue sub-light-emitting region B, the elongated first isolation barrier layer 3B can be disposed on both sides of the blue sub-light-emitting region B, and the first isolation barrier layer 3B extends along the row direction (x direction in Figure 2). The second isolation barrier layer can be elongated, and the second isolation barrier layer 3RG can be disposed in the vertical direction of the row extension (y direction in Figure 2).

[0066] When the first isolation barrier layer 3B is C-shaped or bracket-shaped, it is disposed along the row extension direction, with the two ends of the C-shape or bracket shape in the vertical direction (y-direction) of the row extension, as shown in Figure 3. By blocking the path between the charge generation layers of adjacent light-emitting regions through the isolation barrier layer with the above structure between two adjacent light-emitting regions, this invention greatly solves the problem of lateral crosstalk in series OLED display panels.

[0067] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

[0068] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the protection scope of the present invention.

Claims

1. A series-connected OLED display panel, characterized in that, The device includes a substrate and a pixel layer disposed on one side of the substrate; the pixel layer includes a pixel definition region and a sub-light emission region; the pixel definition region is provided with an isolation barrier layer; the isolation barrier layer has a trapezoidal structure, the bottom edge of the trapezoidal structure is close to the substrate, and the isolation barrier layer separates a charge generation layer in two adjacent sub-light emission regions.

2. The tandem OLED display panel according to claim 1, characterized in that, It also includes a pixel driving circuit layer disposed between the substrate and the pixel layer; the pixel driving circuit layer includes a plurality of pixel driving circuit units, and each pixel driving circuit unit includes three sub-driving circuits; the sub-light-emitting region is a blue sub-light-emitting region, a red sub-light-emitting region, or a green sub-light-emitting region, and a blue sub-light-emitting region, a red sub-light-emitting region, and a green sub-light-emitting region constitute a pixel; each sub-driving circuit of each pixel driving circuit unit corresponds to a sub-light-emitting region of a certain color and is configured to drive the sub-light-emitting region of that color to emit light.

3. The tandem OLED display panel according to claim 2, characterized in that, The isolation barrier layer includes a first isolation barrier layer and a second isolation barrier layer; the first isolation barrier layer is disposed in the pixel definition area corresponding to the blue sub-light emission area; the second isolation barrier layer is disposed in the pixel definition area corresponding to the red sub-light emission area and / or the pixel definition area corresponding to the green sub-light emission area.

4. The tandem OLED display panel according to claim 3, characterized in that, Each pixel is quadrilateral; the blue sub-light-emitting areas of multiple pixels are in the same row, and the red and green sub-light-emitting areas of multiple pixels are in an adjacent row, with the red and green sub-light-emitting areas arranged alternately; the first isolation barrier layer is disposed in the direction of row extension; the second isolation barrier layer is disposed in the direction perpendicular to the row extension.

5. The tandem OLED display panel according to claim 4, characterized in that, The first isolation barrier layer is elongated, C-shaped, or bracket-shaped; the second isolation barrier layer is elongated.

6. The tandem OLED display panel according to claim 1, characterized in that, Each of the sub-light-emitting regions includes: a first electrode layer; at least two light-emitting structural layers, wherein the at least two light-emitting structural layers are stacked on the first electrode layer, each light-emitting structural layer including a first carrier transport layer, a light-emitting layer, and a second carrier transport layer, wherein the light-emitting layer is disposed between adjacent first carrier transport layers and second carrier transport layers; at least one charge-generating layer, each charge-generating layer being disposed between two adjacent light-emitting structural layers, each charge-generating layer including a second carrier generating layer, an intermediate layer, and a first carrier generating layer stacked sequentially; a second electrode layer disposed on the side of the at least two light-emitting structural layers facing away from the first electrode layer; and the top of the isolation barrier layer being higher than the top of the charge-generating layer closest to the second electrode layer.

7. The tandem OLED display panel according to claim 6, characterized in that, The top of the isolation barrier layer is located between the bottom and top of the first carrier transport layer of the light-emitting structure layer closest to the second electrode layer.

8. The tandem OLED display panel according to claim 1, characterized in that, The isolation barrier layer includes one or more layers of aromatic amine compounds, azine compounds, or triazine compounds.

9. The tandem OLED display panel according to claim 1, characterized in that, The refractive index of the isolation barrier layer is between 1.6 and 1.8.

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