Display panel, preparation method thereof and display device

Abstract

The application provides a display panel and a preparation method therefor, and a display device. The display panel comprises an array substrate, a first electrode and a second electrode on the array substrate, a light-emitting functional layer between the first electrode and the second electrode, a first encapsulating layer on the side of the second electrode away from the first electrode, and a second encapsulating layer on the side of the first encapsulating layer away from the second electrode. A plurality of first openings are formed in the first encapsulating layer, and the second encapsulating layer is in contact with the second electrode through the first openings. The display panel provided by the application can effectively improve the adhesion between the second encapsulating layer and the second electrode by forming openings in the first encapsulating layer and making the second encapsulating layer contact the second electrode through the openings, thereby improving the bending performance of the device.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a display panel, a method for manufacturing the same, and a display device. Background Technology

[0002] QLED (Quantum Dot Light Emitting Diodes) devices are a type of thin-film display panel with a novel structure. They achieve light emission through electronic excitation of the quantum dot layer, offering advantages such as wide color gamut, high brightness, long lifespan, fast response, ultra-thinness, low power consumption, high purity, and high image quality. QLED devices enable flexible displays and a wider range of display applications, representing a major direction in the development of next-generation display technology.

[0003] However, the performance of existing QLED devices needs to be improved. Summary of the Invention

[0004] In view of this, the purpose of this application is to provide a display panel that can increase the adhesion between film layers and improve device performance.

[0005] To achieve the above objectives, this application provides a display panel comprising:

[0006] Array substrate;

[0007] The first electrode and the second electrode are located on the array substrate;

[0008] A light-emitting functional layer located between the first electrode and the second electrode;

[0009] The first encapsulation layer located on the side of the second electrode away from the first electrode;

[0010] A second encapsulation layer located on the side of the first encapsulation layer away from the second electrode;

[0011] The first encapsulation layer has a plurality of first openings, and the second encapsulation layer contacts the second electrode through the first openings.

[0012] Preferably, the plurality of first openings form a hollow area, thereby giving the first encapsulation layer a mesh structure.

[0013] Preferably, the display panel further includes a dam structure that spacees the light-emitting functional layer, the dam structure including a plurality of second openings that accommodate the light-emitting functional layer, wherein the inner wall of the first opening and the inner wall of the second opening at least partially overlap in orthographic projection on the array substrate.

[0014] Preferably, the second encapsulation layer contains an acidic substance, and the mass ratio of the acidic substance to the second encapsulation layer ranges from 0.01% to 10%.

[0015] Preferably, the acidic substance includes one or more of acrylic acid, acrylate, isobutyric acid, and isobutyrate.

[0016] Preferably, the second encapsulation layer is an organic encapsulation layer and includes one or more of acrylate, epoxy resin, and ink.

[0017] Preferably, the first encapsulation layer is an inorganic encapsulation layer and includes one or more of SiON, SiOx, TiOx, SiNx, and AlOx.

[0018] Preferably, it further includes:

[0019] A third encapsulation layer located on the side of the second encapsulation layer away from the first encapsulation layer, and an insulating layer located between the second encapsulation layer and the third encapsulation layer.

[0020] Preferably, the third encapsulation layer comprises one or more of SiON, SiOx, TiOx, SiNx, and AlOx;

[0021] Preferably, from the first electrode to the second electrode, the light-emitting functional layer includes a hole injection layer, a hole transport layer, a light-emitting layer, and an electron transport layer stacked sequentially.

[0022] Preferably, the first electrode is an anode and the second electrode is a cathode.

[0023] Preferably, in the direction from the first electrode to the second electrode, the light-emitting functional layer includes an electron transport layer, a light-emitting layer, an electron blocking layer, a hole transport layer, and a hole injection layer stacked sequentially.

[0024] Preferably, the first electrode is an anode and the second electrode is a cathode.

[0025] Based on the same inventive concept, this application also discloses a method for manufacturing a display panel, which includes:

[0026] The first electrode is fabricated on the array substrate;

[0027] A light-emitting functional layer is formed on one side of the first electrode;

[0028] A second electrode is formed on the side of the light-emitting functional layer away from the first electrode;

[0029] A first encapsulation layer is formed on the side of the second electrode away from the light-emitting functional layer, and a plurality of first openings are formed on the first encapsulation layer;

[0030] A second encapsulation layer is formed on the side of the first encapsulation layer away from the second electrode, and the second encapsulation layer contacts the second electrode through the first opening.

[0031] Preferably, forming a first encapsulation layer on the side of the second electrode away from the light-emitting functional layer, and forming a plurality of first openings on the first encapsulation layer, includes:

[0032] A first encapsulation layer is formed on the side of the second electrode away from the light-emitting functional layer by vapor deposition;

[0033] A plurality of first openings are formed on the first encapsulation layer by etching;

[0034] Preferably, forming a second encapsulation layer on the side of the first encapsulation layer away from the second electrode, the second encapsulation layer contacting the second electrode through the first opening, includes:

[0035] An acidic substance is mixed into the second encapsulation layer material, and the second encapsulation layer material mixed with the acidic substance is printed by inkjet printing on the side of the first encapsulation layer away from the second electrode and the first opening to form the second encapsulation layer.

[0036] Based on the same inventive concept, this application also discloses a display device, which includes the above-described display panel.

[0037] Compared with the prior art, the display panel provided in this application forms an opening in the first encapsulation layer, and the second encapsulation layer contacts the second electrode through the opening, which can effectively improve the adhesion between the second encapsulation layer and the second electrode, thereby improving the bending performance of the device. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in this application or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a schematic diagram of the hierarchical structure of an existing QLED device;

[0040] Figure 2 A schematic diagram of the hierarchical structure of a display panel provided in a preferred embodiment of this application;

[0041] Figure 3 This is a top view of the first encapsulation layer in a display panel provided in another preferred embodiment of this application;

[0042] Figure 4 A schematic diagram of the hierarchical structure of a display panel provided in another preferred embodiment of this application;

[0043] Figure 5 A schematic diagram of the hierarchical structure of a display panel provided in another preferred embodiment of this application;

[0044] Figure 6 A schematic diagram of the hierarchical structure of a display panel provided in another preferred embodiment of this application;

[0045] Figure 7 A schematic diagram of the hierarchical structure of a display panel provided in another preferred embodiment of this application;

[0046] Figure 8 A flowchart illustrating a method for manufacturing a display panel according to another preferred embodiment of this application;

[0047] Figure 9 A flowchart illustrating a method for manufacturing a display panel according to another preferred embodiment of this application.

[0048] Marker explanation:

[0049] 10. Array substrate; 11. Second opening;

[0050] 1. First electrode;

[0051] 2. Light-emitting functional layer; 21. Hole injection layer; 22. Hole transport layer; 23. Light-emitting layer; 24. Electron transport layer; 25. Electron blocking layer;

[0052] 3. Second electrode;

[0053] 4. Encapsulation layer;

[0054] 5. First encapsulation layer; 51. First opening;

[0055] 6. Second encapsulation layer;

[0056] 7. Third encapsulation layer;

[0057] 8. Insulation layer. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0059] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0060] Reference Figure 1 This is a schematic diagram of the layer structure of a conventional QLED device. The QLED device includes an array substrate 10; a first electrode 1 and a second electrode 3 located on the array substrate 10; a light-emitting functional layer 2 located between the first electrode 1 and the second electrode 3; and an encapsulation layer 4 located on the side of the second electrode 3 away from the light-emitting functional layer 2. The light-emitting functional layer 2 includes at least a light-emitting layer 23, and may further include other functional layers, such as a hole injection layer 21, a hole transport layer 22, an electron blocking layer, a hole blocking layer, an electron transport layer 24, and an electron injection layer.

[0061] Existing QLED devices suffer from insufficient bending performance. Through long-term research, the inventors discovered that the adhesion between film layers is closely related to the bending performance of the device, and poor adhesion is a major cause of poor bending performance. Based on this, this application provides a panel solution, as detailed in the following embodiments.

[0062] Reference Figure 2 As shown, one embodiment of this application discloses a display panel, which includes an array substrate 10; a first electrode 1 and a second electrode 3 located on the array substrate 10; a light-emitting functional layer 2 located between the first electrode 1 and the second electrode 3; a first encapsulation layer 5 located on the side of the second electrode 3 away from the first electrode 1; a second encapsulation layer 6 located on the side of the first encapsulation layer 5 away from the second electrode 3; a plurality of first openings 51 are formed on the first encapsulation layer 5, and the second encapsulation layer 6 contacts the second electrode 3 through the first openings 51.

[0063] The display panel provided in this embodiment forms a first opening 51 on the first encapsulation layer 5, and the second encapsulation layer 6 contacts the second electrode 3 through the first opening 51, which can effectively improve the adhesion between the second encapsulation layer 6 and the second electrode 3, thereby improving the bending performance of the device.

[0064] In one embodiment, the first electrode 1 is the anode and the second electrode 3 is the cathode; in another embodiment, the first electrode 1 is the cathode and the second electrode 3 is the anode. No specific limitation is made.

[0065] Reference Figure 3 As shown, in one embodiment, a plurality of first openings 51 form a hollow area, making the first encapsulation layer 5 have a mesh structure, which can further improve the adhesion between the second encapsulation layer 6 and the second electrode 3, thereby improving the bending performance of the device. The arrangement of the plurality of first openings 51 on the first encapsulation layer 5 may include an array or the like; the shape of the first openings 51 may include rectangles, circles, triangles, etc., which can be set as needed and are not specifically limited.

[0066] Reference Figure 5 As shown, in one embodiment, the display panel further includes a dam structure that spacees the light-emitting functional layer 2. The dam structure includes a plurality of second openings 11 that accommodate the light-emitting functional layer 2. The inner wall of the first opening 51 and the inner wall of the second opening 11 at least partially overlap in orthographic projection pattern on the array substrate 10. This is beneficial for improving light extraction capability and enhancing the light extraction efficiency of the device.

[0067] Reference Figure 4 As shown, in one embodiment, the light-emitting functional layer 2 includes at least a light-emitting layer 23, and may further include other functional layers, such as a hole injection layer 21, a hole transport layer 22, an electron blocking layer, a hole blocking layer, an electron transport layer 24, an electron injection layer, etc.

[0068] In one embodiment, the second encapsulation layer 6 contains an acidic substance; the acidic substance in the second encapsulation layer 6 can enter the second electrode 3 through the first opening 51, promoting positive aging of the device and improving device performance. QLED devices exhibit a phenomenon where various efficiencies (current, power, or external quantum efficiency) increase over time, known as the "positive aging effect." The positive aging effect mainly occurs in organic-inorganic hybrid QLED devices using materials such as zinc oxide (ZnO) as the electron transport layer. It is generally believed that acidic substances can promote the positive aging of QLED devices.

[0069] Preferably, the mass ratio of the acidic substance to the second encapsulation layer 6 ranges from 0.01% to 10%. For example, 0.01%, 0.1%, 1%, 5%, 10%, etc. In other embodiments, the mass ratio of the acidic substance to the second encapsulation layer 6 can be set as needed, for example, 0.005%, 15%, 20%, etc., and is not specifically limited.

[0070] In one embodiment, the first encapsulation layer 5 is formed by vapor deposition, the second encapsulation layer 6 is formed by inkjet printing, and the first opening 51 is formed by etching.

[0071] In one embodiment, the second encapsulation layer 6 is an organic encapsulation layer and includes one or more of acrylates, epoxy resins, and inks, while the acidic substance includes one or more of acrylic acid, acrylates, isobutyric acid, and isobutyrate. In other embodiments, the second encapsulation layer 6 and the acidic substance may also include other materials or combinations, without specific limitations.

[0072] In one embodiment, the first encapsulation layer 5 is an inorganic encapsulation layer and includes one or more of SiON, SiOx, TiOx, SiNx, and AlOx. In other embodiments, the first encapsulation layer 5 may also include other materials or combinations thereof, without specific limitations.

[0073] Reference Figure 6 As shown, in one embodiment, the display panel further includes a third encapsulation layer 7 located on the side of the second encapsulation layer 6 away from the first encapsulation layer 5, and an insulating layer 8 located between the second encapsulation layer 6 and the third encapsulation layer 7. Preferably, the first encapsulation layer 5 is an organic encapsulation layer, the second encapsulation layer 6 is an inorganic encapsulation layer, and the third encapsulation layer 7 is an organic encapsulation layer, thereby achieving an inorganic-organic-inorganic three-layer encapsulation, further improving encapsulation reliability. Preferably, the third encapsulation layer 7 is formed by vapor deposition. Preferably, the third encapsulation layer 7 includes one or more of SiON, SiOx, TiOx, SiNx, and AlOx. Further, the third encapsulation layer 7 may also include other materials, which are not specifically limited. The insulating layer 8 can ensure the insulation between the second encapsulation layer 6 and the third encapsulation layer 7, improving the encapsulation effect.

[0074] In one embodiment, the display panel is a front-facing display panel, see reference. Figure 4 The light-emitting functional layer 2, from the first electrode 1 to the second electrode 3, includes a hole injection layer 21, a hole transport layer 22, a light-emitting layer 23, and an electron transport layer 24 sequentially stacked on the first electrode 1. Preferably, the first electrode 1 is the anode and the second electrode 3 is the cathode. Further, the light-emitting functional layer 2 may also include an electron blocking layer, a hole blocking layer, an electron injection layer, etc.

[0075] Reference Figure 7 As shown, in one embodiment, the display panel is an inverted display panel; wherein, from the first electrode 1 to the second electrode 3, the light-emitting functional layer 2 includes an electron transport layer 24, a light-emitting layer 23, an electron blocking layer 25, a hole transport layer 22, and a hole injection layer 21 sequentially stacked on the first electrode 1. Preferably, the first electrode 1 is an anode and the second electrode 3 is a cathode. Further, the light-emitting functional layer 2 may also include a hole blocking layer, an electron injection layer, etc.

[0076] Based on the same inventive concept, and referring to Figure 8As shown, another embodiment of this application discloses a method for fabricating a display panel. The display panel fabricated by this method can be referred to... Figure 2 The method for manufacturing this display panel includes the following steps:

[0077] Step S10: Fabricate the first electrode 1 on the array substrate 10;

[0078] Step S20: Form a light-emitting functional layer 2 on one side of the first electrode 1;

[0079] Step S30: Form a second electrode 3 on the side of the light-emitting functional layer 2 away from the first electrode 1;

[0080] Step S40: A first encapsulation layer 5 is formed on the side of the second electrode 3 away from the light-emitting functional layer 2, and a plurality of first openings 51 are formed on the first encapsulation layer 5.

[0081] Step S50: A second encapsulation layer 6 is formed on the side of the first encapsulation layer 5 away from the second electrode 3, and the second encapsulation layer 6 contacts the second electrode 3 through an opening.

[0082] The display panel fabrication method provided in this embodiment forms a first opening 51 on the first encapsulation layer 5, and the second encapsulation layer 6 contacts the second electrode 3 through the first opening 51, which can effectively improve the adhesion between the second encapsulation layer 6 and the second electrode 3, thereby improving the bending performance of the device.

[0083] In one embodiment, the first electrode 1 is the anode and the second electrode 3 is the cathode; in another embodiment, the first electrode 1 is the cathode and the second electrode 3 is the anode. No specific limitation is made.

[0084] In one embodiment, a plurality of first openings 51 form a hollow area, making the first encapsulation layer 5 have a mesh structure, which can further improve the adhesion between the second encapsulation layer 6 and the second electrode 3, thereby improving the bending performance of the device.

[0085] In one embodiment, step S40 involves forming a first encapsulation layer 5 on the side of the second electrode 3 away from the light-emitting functional layer 2, and forming a first opening 51 on the first encapsulation layer 5, including:

[0086] The first encapsulation layer 5 is formed on the side of the second electrode 3 away from the light-emitting functional layer 2 by vapor deposition;

[0087] A first opening 51 is formed on the first encapsulation layer 5 by etching.

[0088] In one embodiment, step S50 involves forming a second encapsulation layer 6 on the side of the first encapsulation layer 5 away from the second electrode 3, the second encapsulation layer 6 contacting the second electrode 3 through a first opening 51, including:

[0089] An acidic substance is mixed into the second encapsulation layer material, and the second encapsulation layer material mixed with the acidic substance is printed into the side of the first encapsulation layer 5 away from the second electrode 3 and the first opening 51 by inkjet printing to form the second encapsulation layer 6. The acidic substance contained in the second encapsulation layer 6 can enter the second electrode 3 through the first opening 51, promote the positive aging of the device, and improve the device performance.

[0090] Preferably, the mass ratio of the acidic substance to the second encapsulation layer 6 ranges from 0.01% to 10%. For example, 0.01%, 0.1%, 1%, 5%, 10%, etc. In other embodiments, the mass ratio of the acidic substance to the second encapsulation layer 6 can be set as needed, for example, 0.005%, 15%, 20%, etc., and is not specifically limited.

[0091] In one embodiment, the second encapsulation layer 6 is an organic encapsulation layer and includes one or more of acrylates, epoxy resins, and inks, while the acidic substance includes one or more of acrylic acid, acrylates, isobutyric acid, and isobutyrate. In other embodiments, the second encapsulation layer 6 and the acidic substance may also include other materials or combinations, without specific limitations.

[0092] In one embodiment, the first encapsulation layer 5 is an inorganic encapsulation layer and includes one or more of SiON, SiOx, TiOx, SiNx, and AlOx. In other embodiments, the first encapsulation layer 5 may also include other materials or combinations thereof, without specific limitations.

[0093] Reference Figure 9 As shown, in one embodiment, the method for manufacturing the display panel further includes the following steps:

[0094] Step S60: An insulating layer 8 is formed on the side of the second encapsulation layer 6 away from the first encapsulation layer 5;

[0095] Step S70: A third encapsulation layer 7 is formed on the side of the insulating layer 8 away from the second encapsulation layer 6. Preferably, the first encapsulation layer 5 is an organic encapsulation layer, the second encapsulation layer 6 is an inorganic encapsulation layer, and the third encapsulation layer 7 is an organic encapsulation layer, thereby achieving an inorganic-organic-inorganic three-layer encapsulation, further improving encapsulation reliability. The insulating layer 8 ensures insulation between the second encapsulation layer 6 and the third encapsulation layer 7, improving the encapsulation effect. Preferably, the third encapsulation layer 7 is formed by vapor deposition.

[0096] Another embodiment of this application discloses a display device, which includes the display panel described in the above embodiments. This display device can be used on smart devices (such as mobile phones, VR devices, computers, televisions, in-vehicle displays, etc.).

[0097] In this embodiment, the display panel of the display device forms a first opening 51 on the first encapsulation layer 5, through which the second encapsulation layer 6 contacts the second electrode 3. This effectively improves the adhesion between the second encapsulation layer 6 and the second electrode 3, thereby improving the bending performance of the display panel and the performance of the display device.

[0098] Although this application has been described in conjunction with specific embodiments thereof, many substitutions, modifications and variations of these embodiments will be apparent to those skilled in the art from the foregoing description.

[0099] It should be noted that the above description describes some embodiments of this application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in a different order than that shown in the above embodiments and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0100] The embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this application should be included within the protection scope of this application.

Claims

1. A display panel, characterized in that, include: Array substrate; The first electrode and the second electrode are located on the array substrate; A light-emitting functional layer located between the first electrode and the second electrode; A first encapsulation layer located on the side of the second electrode away from the first electrode; the first encapsulation layer is an inorganic encapsulation layer; A second encapsulation layer is located on the side of the first encapsulation layer away from the second electrode; the second encapsulation layer is an organic encapsulation layer. The first encapsulation layer has a plurality of first openings, the second encapsulation layer contacts the second electrode through the first openings, the second encapsulation layer contains an acidic substance, and the acidic substance contained in the second encapsulation layer can enter the second electrode through the first openings; the light-emitting functional layer includes at least a quantum dot light-emitting layer. The plurality of first openings form a hollow area, thereby making the first encapsulation layer have a mesh structure; The display panel further includes a dam structure that spacees the light-emitting functional layer. The dam structure includes a plurality of second openings that accommodate the light-emitting functional layer. The orthographic projection patterns of the inner walls of the first openings and the second openings on the array substrate at least partially overlap.

2. The display panel as described in claim 1, characterized in that, The mass ratio of the acidic substance to the second encapsulation layer ranges from 0.01% to 10%.

3. The display panel as described in claim 2, characterized in that, The acidic substance includes one or more of acrylic acid, acrylate, isobutyric acid, and isobutyrate.

4. The display panel as described in claim 1, characterized in that, The second encapsulation layer comprises one or more of acrylate, epoxy resin, and ink.

5. The display panel as described in claim 1, characterized in that, The first encapsulation layer includes one or more of SiON, SiOx, TiOx, SiNx, and AlOx.

6. The display panel as described in claim 1, characterized in that, Also includes: A third encapsulation layer located on the side of the second encapsulation layer away from the first encapsulation layer, and an insulating layer located between the second encapsulation layer and the third encapsulation layer.

7. The display panel as described in claim 6, characterized in that, The third encapsulation layer includes one or more of SiON, SiOx, TiOx, SiNx, and AlOx.

8. The display panel as described in claim 1, characterized in that, From the first electrode to the second electrode, the light-emitting functional layer includes a hole injection layer, a hole transport layer, a light-emitting layer, and an electron transport layer stacked sequentially.

9. The display panel as described in claim 8, characterized in that, The first electrode is the anode, and the second electrode is the cathode.

10. The display panel as claimed in claim 1, characterized in that, From the first electrode to the second electrode, the light-emitting functional layer includes an electron transport layer, a light-emitting layer, an electron blocking layer, a hole transport layer, and a hole injection layer stacked sequentially.

11. The display panel as claimed in claim 10, characterized in that, The first electrode is the anode, and the second electrode is the cathode.

12. A method for manufacturing a display panel, used to manufacture the display panel as described in any one of claims 1-11, characterized in that, include: The first electrode is fabricated on the array substrate; A light-emitting functional layer is formed on one side of the first electrode; A second electrode is formed on the side of the light-emitting functional layer away from the first electrode; A first encapsulation layer is formed on the side of the second electrode away from the light-emitting functional layer, and a plurality of first openings are formed on the first encapsulation layer; A second encapsulation layer is formed on the side of the first encapsulation layer away from the second electrode, and the second encapsulation layer contacts the second electrode through the first opening.

13. The method for manufacturing a display panel as described in claim 12, characterized in that, The first encapsulation layer is formed on the side of the second electrode away from the light-emitting functional layer, and a plurality of first openings are formed on the first encapsulation layer, including: A first encapsulation layer is formed on the side of the second electrode away from the light-emitting functional layer by vapor deposition; A plurality of first openings are formed on the first encapsulation layer by etching.

14. The method for manufacturing a display panel as described in claim 12, characterized in that, The step of forming a second encapsulation layer on the side of the first encapsulation layer away from the second electrode, wherein the second encapsulation layer contacts the second electrode through the first opening, includes: An acidic substance is mixed into the second encapsulation layer material, and the second encapsulation layer material mixed with the acidic substance is printed by inkjet printing on the side of the first encapsulation layer away from the second electrode and the first opening to form the second encapsulation layer.

15. A display device, characterized in that, The display device includes a display panel as described in any one of claims 1-11.

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