Display panel, manufacturing method thereof, and display device

Abstract

The present invention discloses a display panel, a manufacturing method thereof, and a display device. The display panel includes a substrate, a driving circuit layer, and a light-emitting functional layer; the driving circuit layer is disposed on the substrate and includes signal terminals disposed in a non-display area; the light-emitting functional layer is disposed on a side of the driving circuit layer away from the substrate and includes a stacked electron transport layer and a cathode layer, the electron transport layer is disposed in the display area and extends to the non-display area, and includes a first conduction portion located on a side of the signal terminal away from the substrate, the cathode layer is located in the display area and extends to the non-display area, and includes a signal connection portion disposed on a side of the first conduction portion away from the signal terminal; wherein, the Fermi level on a side of the signal terminal close to the first conduction portion is greater than the Fermi level of the first conduction portion, and the Fermi level of the first conduction portion is greater than the Fermi level of the signal connection portion. The present invention can use the same mask to prepare the cathode layer and the electron transport layer, so as to simplify the process steps and reduce the cost.

Description

Technical Field

[0001] The present invention relates to the field of display technologies, and particularly to a display panel, a manufacturing method thereof, and a display device. Background Art

[0002] With the development of display technologies, in order to reduce costs, an inkjet printing method is adopted to form a hole injection layer, a hole transport layer, and a light-emitting layer in an OLED (Organic Light-Emitting Diode) display panel. The electron injection layer, the electron transport layer, and the cathode are usually formed by evaporation or sputtering.

[0003] In the process of manufacturing an OLED display panel, since the cathode needs to be connected to a signal terminal in a non-display area to realize signal input of the cathode, and the materials of the electron injection layer and the electron transport layer have high resistance and poor conductivity. Therefore, the coverage area of the cathode needs to be larger than that of the electron injection layer and the electron transport layer to enable good signal transmission between the cathode and the signal terminal, resulting in the need to use two masks to prepare the cathode, the electron injection layer, and the electron transport layer, increasing the process flow and process cost, and reducing the manufacturing efficiency. Summary of the Invention

[0004] Embodiments of the present invention provide a display panel, a manufacturing method thereof, and a display device, which can simplify the process flow and reduce the process cost.

[0005] Embodiments of the present invention provide a display panel. The display panel includes a display area and a non-display area adjacent to the display area. The display panel further includes:

[0006] a substrate;

[0007] a driving circuit layer disposed on the substrate, the driving circuit layer including a signal terminal disposed in the non-display area;

[0008] a light-emitting functional layer disposed on a side of the driving circuit layer away from the substrate. The light-emitting functional layer includes an electron transport layer and a cathode layer stacked. The electron transport layer is disposed in the display area and extends to the non-display area. The electron transport layer includes a first conduction portion on a side of the signal terminal away from the substrate. The cathode layer is disposed in the display area and extends to the non-display area. The cathode layer includes a signal connection portion on a side of the first conduction portion away from the signal terminal;

[0009] wherein, a Fermi level on a side of the signal terminal close to the first conduction portion is greater than a Fermi level of the first conduction portion, and the Fermi level of the first conduction portion is greater than a Fermi level of the signal connection portion.

[0010] In one embodiment of the present invention, the signal terminal includes a signal transmission portion and a protective metal portion, and the first conduction portion is disposed on a surface of the protective metal portion away from the signal transmission portion, and the Fermi level of the protective metal portion is greater than the Fermi level of the first conduction portion.

[0011] In one embodiment of the present invention, the signal terminal includes a signal transmission portion, and the first conduction portion is disposed on a surface of the signal transmission portion away from the substrate side;

[0012] Wherein, the signal transmission portion includes a plurality of stacked signal sub-portions, and the plurality of signal sub-portions include a first signal sub-portion in contact with the first conduction portion, and the Fermi level of the first signal sub-portion is greater than the Fermi level of the first conduction portion.

[0013] In one embodiment of the present invention, the light-emitting functional layer further includes an electron injection layer disposed between the electron transport layer and the cathode layer, the electron injection layer is disposed in the display area and extends to the non-display area, and the electron injection layer includes a second conduction portion disposed between the first conduction portion and the signal connection portion;

[0014] Wherein, the Fermi level of the first conduction portion is greater than the Fermi level of the second conduction portion, and the Fermi level of the second conduction portion is greater than the Fermi level of the signal connection portion.

[0015] In one embodiment of the present invention, the material of the electron transport layer and the material of the electron injection layer are each independently selected from at least one of an N-type doped organic semiconductor material, an organometallic complex material, and an organic semiconductor material.

[0016] In one embodiment of the present invention, the Fermi level of the first conduction portion is greater than or equal to -5.5 eV and less than or equal to -3.5 eV, and the Fermi level of the second conduction portion is greater than or equal to -5.5 eV and less than or equal to -3.5 eV.

[0017] In one embodiment of the present invention, the material of the electron transport layer and the material of the electron injection layer are each independently selected from at least one of a single metal material, an alloy material, a metal oxide material, and a metal salt material.

[0018] In one embodiment of the present invention, the Fermi level of the first conduction portion gradually decreases in a direction away from the signal terminal, and the thickness of the first conduction portion is greater than or equal to 40 nanometers.

[0019] In one embodiment of the present invention, the Fermi level of the second conduction portion gradually decreases in a direction away from the signal terminal, and the thickness of the second conduction portion is greater than or equal to 40 nanometers.

[0020] In an embodiment of the present invention, the difference between the Fermi level of the first conduction part and the Fermi level of the signal connection part is less than or equal to 2 eV, and the difference between the Fermi level on the side of the signal terminal close to the first conduction part and the Fermi level of the first conduction part is less than or equal to 2 eV.

[0021] Based on the above object of the present invention, an embodiment of the present invention further provides a method for manufacturing a display panel. The display panel includes a display area and a non-display area adjacent to the display area. The method for manufacturing the display panel includes the following steps:

[0022] Provide a substrate;

[0023] Form a driving circuit layer on the substrate. The driving circuit layer includes signal terminals formed in the non-display area.

[0024] Form a light-emitting functional layer on the side of the driving circuit layer away from the substrate. The light-emitting functional layer includes a stacked electron transport layer and a cathode layer. The electron transport layer is formed in the display area and extends to the non-display area. The electron transport layer includes a first conduction part on the side of the signal terminal away from the substrate. The cathode layer is formed in the display area and extends to the non-display area. The cathode layer includes a signal connection part on the side of the first conduction part away from the signal terminal. Among them, the Fermi level on the side of the signal terminal close to the first conduction part is greater than the Fermi level of the first conduction part, and the Fermi level of the first conduction part is greater than the Fermi level of the signal connection part.

[0025] In an embodiment of the present invention, forming the light-emitting functional layer on the side of the driving circuit layer away from the substrate further includes the following steps:

[0026] Use the same mask to sequentially form the electron transport layer and the cathode layer on the side of the driving circuit layer away from the substrate.

[0027] Based on the above object of the present invention, an embodiment of the present invention further provides a display device, and the display device includes the display panel.

[0028] Advantages of the present invention: In the display panel provided by the present invention, the electron transport layer includes a first conduction part located in the non-display area, the cathode layer includes a signal connection part located in the non-display area, and the first conduction part is located between the signal terminal and the signal connection part. In the present invention, the Fermi levels of the signal terminal, the first conduction part, and the signal connection part are set such that the Fermi level on the side of the signal terminal close to the first conduction part is greater than the Fermi level of the first conduction part, and the Fermi level of the first conduction part is greater than the Fermi level of the signal connection part. Furthermore, at the contact interface between the signal terminal and the first conduction part and at the contact interface between the first conduction part and the signal connection part, electrons migrate from the high-energy-level film layer to the low-energy-level film layer, and the electron migration barrier in this process is relatively low. As a result, good ohmic contact can be achieved between the signal terminal and the first conduction part and between the first conduction part and the signal connection part, showing a relatively small contact resistance, enabling the signal terminal and the signal connection part to be electrically connected, and allowing the cathode layer to receive the electrical signal in the signal terminal. Further, in the present invention, the first conduction part can realize the electrical connection between the cathode layer and the signal terminal. Thus, the same mask can be used to fabricate the cathode layer and the electron transport layer, simplifying the process steps and reducing the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The following, with reference to the drawings and through a detailed description of the specific embodiments of the present invention, will make the technical solutions and other beneficial effects of the present invention obvious.

[0030] Figure 1 FIG. [ID] is a schematic diagram of a manufacturing process structure of a display panel in the related art;

[0031] Figure 2 FIG. [ID] is another schematic diagram of a manufacturing process structure of a display panel in the related art;

[0032] Figure 3 FIG. [ID] is a schematic diagram of a planar film layer distribution structure of a display panel in the related art;

[0033] Figure 4 FIG. [ID] is a schematic diagram of a structure of a display panel provided by an embodiment of the present invention in the non-display area;

[0034] Figure 5 FIG. [ID] is a schematic diagram of a structure of a display panel provided by an embodiment of the present invention;

[0035] Figure 6 FIG. [ID] is a schematic diagram of a planar film layer distribution structure of a display panel provided by an embodiment of the present invention;

[0036] Figure 7 FIG. [ID] is another schematic diagram of a structure of a display panel provided by an embodiment of the present invention in the non-display area;

[0037] Figure 8Another structural schematic diagram of the display panel provided by the embodiment of the present invention;

[0038] Figure 9 Flowchart of the manufacturing method of the display panel provided by the embodiment of the present invention. Detailed implementation manners

[0039] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present invention.

[0040] The following disclosure provides many different embodiments or examples for implementing different structures of the present invention. To simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are only examples and are not intended to limit the present invention. In addition, the present invention may repeat reference numerals and / or reference letters in different examples. Such repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides examples of various specific processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0041] Please refer to Figure 1 、 Figure 2 and Figure 3 , where Figure 1 and Figure 2 are both Figure 3Cross-sectional view taken along line CC. In the related art, the negative electrode 1 of the OLED display panel needs to extend into the non-display area BA to overlap with the terminal 2 for signal transmission. Specifically, since both the negative electrode 1 and the electronic functional layer 3 need to be prepared by evaporation or sputtering processes and a mask is required to control the film formation range. Further, since the negative electrode 1 needs to overlap with the terminal 2, the negative electrode 1 and the electronic functional layer 3 need to be prepared using masks with different opening sizes respectively. For example, the electronic functional layer 3 can be first formed using the mask 4, and the coverage range of the electronic functional layer 3 is controlled to expose the upper surface of the protective metal 6, where the protective metal 6 is located on the upper surface of the terminal 2 to provide protection for the terminal 2, and the protective metal 6 is electrically connected to the terminal 2. Then the negative electrode 1 is formed using the mask 5, and the opening area of the mask 5 is larger than that of the mask 4. Consequently, the coverage range of the negative electrode 1 is also larger than the coverage area of the electronic functional layer 3, so that the negative electrode 1 can cover the upper surface of the protective metal 6 to achieve the electrical connection between the negative electrode 1 and the terminal 2. Therefore, in the related art, different masks are required to complete the preparation of the electronic functional layer 3 and the negative electrode 1, which not only increases the process flow and process cost but also is not conducive to improving the preparation efficiency.

[0042] An embodiment of the present invention provides a display panel. Please refer to Figure 3 and Figure 4 , the display panel includes a display area 101 and a non-display area 102 adjacent to the display area 101.

[0043] The display panel further includes a substrate 10, a driving circuit layer 20, and a light-emitting functional layer 30. Among them, the driving circuit layer 20 is disposed on the substrate 10, and the driving circuit layer 20 includes a signal terminal 21 disposed in the non-display area 102. The light-emitting functional layer 30 is disposed on a side of the driving circuit layer 20 away from the substrate 10. The light-emitting functional layer 30 includes a stacked electron transport layer 311 and a cathode layer 32. The electron transport layer 311 is disposed in the display area 101 and extends into the non-display area 102. The electron transport layer 311 includes a first conduction portion 3101 on a side of the signal terminal 21 away from the substrate 10. The cathode layer 32 is disposed in the display area 101 and extends into the non-display area 102. The cathode layer 32 includes a signal connection portion 320 on a side of the first conduction portion 3101 away from the signal terminal 21.

[0044] Further, the Fermi level on a side of the signal terminal 21 close to the first conduction portion 3101 is greater than the Fermi level of the first conduction portion 3101, and the Fermi level of the first conduction portion 3101 is greater than the Fermi level of the signal connection portion 320.

[0045] In the implementation and application process, in the display panel provided by the embodiment of the present invention, the electron transport layer 311 includes a first conduction part 3101 located in the non-display area 102, the cathode layer 32 includes a signal connection part 320 located in the non-display area 102, and the first conduction part 3101 is located between the signal terminal 21 and the signal connection part 320. In the embodiment of the present invention, the Fermi levels of the signal terminal 21, the first conduction part 3101, and the signal connection part 320 are set such that the Fermi level of a part of the signal terminal 21 in contact with the first conduction part 3101 is greater than the Fermi level of the first conduction part 3101, and the Fermi level of the first conduction part 3101 is greater than the Fermi level of the signal connection part 320. Further, at the contact interface between the signal terminal 21 and the first conduction part 3101 and at the contact interface between the first conduction part 3101 and the signal connection part 320, electrons migrate from the high-energy-level film layer to the low-energy-level film layer, and the electron migration barrier in this process is relatively low. Thus, good Ohmic contact can be achieved between the signal terminal 21 and the first conduction part 3101 and between the first conduction part 3101 and the signal connection part 320, showing a small contact resistance, enabling conduction between the signal terminal 21 and the signal connection part 320, and allowing the cathode layer 32 to receive the electrical signal in the signal terminal 21. Further, in the embodiment of the present invention, the first conduction part 3101 can achieve conduction between the cathode layer 32 and the signal terminal 21. Thus, the same mask can be used to fabricate the cathode layer 32 and the electron transport layer 311, simplifying the process steps and reducing the cost.

[0046] Specifically, the structure of the display panel provided by the embodiment of the present invention will be described in detail below.

[0047] In an embodiment of the present invention, please continue to refer to Figure 4 and Figure 5 , in which the display panel includes a substrate 10, a driving circuit layer 20 disposed on the substrate 10, and a light-emitting functional layer 30 disposed on the driving circuit layer 20. The display panel may include a thin-film encapsulation layer (not shown in the figure) disposed on the light-emitting functional layer 30, which is not limited herein.

[0048] Further, the driving circuit layer 20 includes an active layer 25 sequentially disposed on the substrate 10, a passivation layer 27 disposed on the substrate 10 and covering the active layer 25, a gate 26 disposed on the passivation layer 27, a gate insulating layer 28 disposed on the passivation layer 27 and covering the gate 26, a source 221 and a drain 222 disposed on the gate insulating layer 28, an interlayer dielectric layer 23 disposed on the gate insulating layer 28 and covering the source 221 and the drain 222, and a planarization layer 24 disposed on the interlayer dielectric layer 23. Among them, the active layer 25, the gate 26, the source 221, and the drain 222 are all disposed within the display area 101. The gate 26 is located above the active layer 25, while the source 221 and the drain 222 are respectively located on both sides above the active layer 25, and both pass through the gate insulating layer 28 and the passivation layer 27 to overlap with both sides of the active layer 25.

[0049] In an embodiment of the present invention, the driving circuit layer 20 further includes a signal terminal 21. Among them, the signal terminal 21 includes a signal transmission portion 211 and a protective metal portion 212 which are stacked, and the signal transmission portion 211 is located between the protective metal portion 212 and the substrate 10.

[0050] The signal transmission portion 211 can be fabricated on the same layer as the source 221 and the drain 222, and the material of the signal transmission portion 211 can also be the same as that of the source 221 and the drain 222, such as copper or aluminum.

[0051] Among them, an opening is provided in the interlayer dielectric layer 23 corresponding to the signal terminal 21 to expose the upper surface of the protective metal portion 212, and the protective metal portion 212 covers the upper surface of the signal transmission portion 211 to prevent the signal transmission portion 211 from being oxidized and corroded, and the material of the protective metal portion 212 can be a molybdenum-titanium alloy; on the other hand, the protective metal portion 212 has conductivity and does not affect the signal transmission of the signal transmission portion 211.

[0052] The light-emitting functional layer 30 includes a plurality of anodes 34 disposed on the planarization layer 24, a pixel defining layer 33 disposed on the planarization layer 24, a hole injection layer 35, a hole transport layer 36, an organic light-emitting layer 37, an electron transport layer 311, and a cathode layer 32 disposed on the pixel defining layer 33.

[0053] Among them, the pixel definition layer 33 includes a plurality of pixel openings 330, and each pixel opening 330 corresponds to an anode 34, so as to expose a part of the upper surface of the corresponding anode 34. The hole injection layer 35, the hole transport layer 36, and the organic light-emitting layer 37 are stacked and continuously cover the plurality of pixel openings 330. Further, in the embodiment of the present invention, the planarization layer 24 and the pixel definition layer 33 form a lap hole 300 in the non-display area 102 to expose a part of the upper surface of the protective metal part 212, and the coverage boundaries of the hole injection layer 35, the hole transport layer 36, and the organic light-emitting layer 37 can all be located on the side of the lap hole 300 close to the display area 101.

[0054] In the embodiment of the present invention, the electron transport layer 311 is disposed in the display area 101 and extends into the non-display area 102, and the electron transport layer 311 includes a first conduction part 3101 located on the side of the protective metal part 212 away from the substrate 10; the cathode layer 32 is disposed in the display area 101 and extends into the non-display area 102, and the cathode layer 32 includes a signal connection part 320 located on the side of the first conduction part 3101 away from the signal transmission part 211. That is, at the position of the display panel corresponding to the lap hole 300, the signal transmission part 211, the protective metal part 212, the first conduction part 3101, and the signal connection part 320 are stacked in order from bottom to top.

[0055] Among them, the Fermi level of the protective metal part 212 is greater than the Fermi level of the cathode layer 32, and the Fermi level of the first conduction part 3101 is greater than the Fermi level of the signal connection part 320. Furthermore, at the contact interface between the protective metal part 212 and the first conduction part 3101 and at the contact interface between the first conduction part 3101 and the signal connection part 320, electrons migrate from the high-energy-level film layer to the low-energy-level film layer, and the electron migration barrier in this process is relatively low, so that good ohmic contact can be achieved between the protective metal part 212 and the first conduction part 3101 and between the first conduction part 3101 and the signal connection part 320, showing a relatively small lap resistance, enabling conduction between the protective metal part 212 and the signal connection part 320, and enabling the cathode layer 32 to receive the electrical signal in the signal terminal 21.

[0056] Optionally, the difference between the Fermi level of the protective metal part 212 and the Fermi level of the first conduction part 3101 and the difference between the Fermi level of the first conduction part 3101 and the Fermi level of the signal connection part 320 are both less than or equal to 2 eV, making the Fermi levels of the three closer to reduce the energy required for electrons to migrate between the three, and making it easier for the protective metal part 212, the first conduction part 3101, and the signal connection part 320 to conduct.

[0057] Continuing from the above, in the embodiments of the present invention, by setting the Fermi levels of the protective metal part 212, the first conduction part 3101, and the signal connection part 320, the contact resistance between the three can be effectively reduced. Furthermore, a current path can be formed between the signal transmission part 211 and the signal connection part 320 to achieve signal transmission between the signal transmission part 211 and the cathode layer 32. Moreover, in the embodiments of the present invention, there is no need to limit the coverage range of the electron transport layer 311, and the coverage range of the electron transport layer 311 can be the same as that of the cathode layer 32, that is, the same mask 40 can be used to fabricate the electron transport layer 311 and the cathode layer 32, thereby simplifying the process steps and reducing the process cost.

[0058] In addition, please refer to Figure 3 , in the related art, the electronic functional layer 3 covers the display area AA and extends to the non-display area BA, and the boundary of the electronic functional layer 3 is located on the side of the terminal 2 close to the display area AA, while the cathode electrode 1 covers the display area AA and extends into the non-display area BA and covers the terminal 2. In the related art, in addition to controlling the coverage range of the electronic functional layer 3, a certain distance also needs to be maintained between the terminal 2 and the display area AA to prevent the electronic functional layer 3 from affecting the contact between the cathode electrode 1 and the terminal 2. In the embodiments of the present invention, please refer to Figure 4 and Figure 6 , since the electron transport layer 311 and the cathode layer 32 can be fabricated using the same mask 40, the coverage ranges of the electron transport layer 311 and the cathode layer 32 are the same. Furthermore, the distance between the signal terminal 21 and the display area 101 can be reduced to reduce the border width of the display panel and achieve a narrow border for the display panel.

[0059] Furthermore, in another embodiment of the present invention, please refer to Figure 7 and Figure 8 , the light-emitting functional layer 30 may further include an electron injection layer 312 disposed between the electron transport layer 311 and the cathode layer 32.

[0060] The electron injection layer 312 is disposed within the display area 101 and extends to the non-display area 102. The electron injection layer 312 includes a second conduction part 3102 disposed between the first conduction part 3101 and the signal connection part 320.

[0061] In this embodiment, the first conduction part 3101 is located between the protective metal part 212 and the second conduction part 3102. The Fermi level of the first conduction part 3101 is greater than the Fermi level of the second conduction part 3102. And the Fermi level of the first conduction part 3101 is less than the Fermi level of the protective metal part 212, and the Fermi level of the second conduction part 3102 is greater than the Fermi level of the signal connection part 320.

[0062] Preferably, in the embodiments of the present invention, the signal connection portion 320 and the other parts of the cathode layer 32 are integrally formed and made of the same material; the first conduction portion 3101 and the other parts of the electron transport layer 311 are integrally formed and made of the same material; the second conduction portion 3102 and the other parts of the electron injection layer 312 are integrally formed and made of the same material.

[0063] It can be understood that by selecting the materials of the electron transport layer 311 and the electron injection layer 312, the Fermi levels of the electron transport layer 311 and the electron injection layer 312 can meet the requirements, that is, the Fermi level of the protective metal portion 212 is greater than the Fermi level of the first conduction portion 3101, the Fermi level of the first conduction portion 3101 is greater than the Fermi level of the second conduction portion 3102, the Fermi level of the second conduction portion 3102 is greater than the Fermi level of the signal connection portion 320, and at the same time, the LUMO level and the HOMO level are matched to meet the light emission requirements of the display panel.

[0064] Optionally, the materials of the electron transport layer 311 and the electron injection layer 312 can be independently selected from at least one of N-type doped organic semiconductor materials, organometallic complex materials, and organic semiconductor materials; among them, the organometallic complex materials can include Liq (lithium quinolate), Alq (aluminum quinolate), Gaq (gallium quinolate), CuPc (copper phthalocyanine), etc., and the N-type doped organic semiconductor materials can include organic semiconductor materials doped with electron-rich materials, and the electron-rich materials can be Li, Yb, Ba, etc.

[0065] At this time, the Fermi level of the first conduction portion 3101 can be greater than or equal to -5.5 eV and less than or equal to -3.5 eV, that is, the Fermi level of the electron transport layer 311 can be greater than or equal to -5.5 eV and less than or equal to -3.5 eV; the Fermi level of the second conduction portion 3102 can be greater than or equal to -5.5 eV and less than or equal to -3.5 eV, that is, the Fermi level of the electron injection layer 312 can be greater than or equal to -5.5 eV and less than or equal to -3.5 eV.

[0066] Optionally, the difference between the Fermi level of the second conduction portion 3102 and the Fermi level of the signal connection portion 320 is less than or equal to 2 eV, the difference between the Fermi level of the protective metal portion 212 and the Fermi level of the first conduction portion 3101 is less than or equal to 2 eV, and the difference between the Fermi level of the first conduction portion 3101 and the Fermi level of the second conduction portion 3102 is less than or equal to 2 eV, so that the Fermi levels of the above four are closer, so as to reduce the energy required for electrons to migrate between the four, and make it easier for the protective metal portion 212, the first conduction portion 3101, the second conduction portion 3102, and the signal connection portion 320 to conduct.

[0067] Further, the materials of the electron transport layer 311 and the electron injection layer 312 can each independently be selected from at least one of elemental metal materials, alloy materials, metal oxide materials, and metal salt materials. Among them, the elemental metal materials can include Li, Yb, Ca, and Ba; the alloy materials can include LiAl alloy and CsAg alloy; the metal oxide materials can include ZnO and InO; the metal salt materials can include LiF, NaF, CaF2, and CsF.

[0068] In addition, in the embodiments of the present invention, when the thickness of the first conduction part 3101 is relatively large, the Fermi level of the first conduction part 3101 can be gradually decreased in the direction away from the protection metal part 212. For example, when the thickness of the first conduction part 3101 is greater than or equal to 40 nanometers, the Fermi level of the first conduction part 3101 is gradually decreased in the direction away from the protection metal part 212 to further improve the conduction performance of the first conduction part 3101. Similarly, when the thickness of the second conduction part 3102 is relatively large, the Fermi level of the second conduction part 3102 can be gradually decreased in the direction away from the protection metal part 212. For example, when the thickness of the second conduction part 3102 is greater than or equal to 40 nanometers, the Fermi level of the second conduction part 3102 is gradually decreased in the direction away from the protection metal part 212.

[0069] It should be noted that in the embodiments of the present invention, the Fermi levels of the first conduction part 3101 and the second conduction part 3102 can be changed by doping the first conduction part 3101 and the second conduction part 3102 with electron-rich materials, and the Fermi levels of the first conduction part 3101 and the second conduction part 3102 increase with the increase of the doping degree. In addition, in the embodiments of the present invention, the signal connection part 320 can also be made of the same material as the protection metal part 212, and the Fermi level can be adjusted by controlling the doping degree of at least one of the signal connection part 320 and the protection metal part 212 to satisfy that the Fermi level of the protection metal part 212 is greater than the Fermi level of the signal connection part 320.

[0070] Continuing from the above, in the display panel provided by the embodiment of the present invention, the electron transport layer 311 includes a first conduction part 3101 located in the non-display area 102, the electron injection layer 312 includes a second conduction part 3102 in the non-display area 102, the cathode layer 32 includes a signal connection part 320 located in the non-display area 102, and the first conduction part 3101 and the second conduction part 3102 are stacked between the signal terminal 21 and the signal connection part 320. In the implementation of the present invention, the Fermi levels of the signal terminal 21, the first conduction part 3101, the second conduction part 3102, and the signal connection part 320 are set. Among them, the Fermi level of a part of the signal terminal 21 in contact with the first conduction part 3101 is greater than the Fermi level of the first conduction part 3101, the Fermi level of the first conduction part 3101 is greater than the Fermi level of the second conduction part 3102, and the Fermi level of the second conduction part 3102 is greater than the Fermi level of the signal connection part 320. Furthermore, at the contact interface between the protective metal part 212 and the first conduction part 3101, the contact interface between the first conduction part 3101 and the second conduction part 3102, and the contact interface between the second conduction part 3102 and the signal connection part 320, electrons all migrate from the high-energy-level film layer to the low-energy-level film layer, and the electron migration barrier in this process is relatively low. Therefore, good ohmic contacts can be achieved between the protective metal part 212 and the first conduction part 3101, between the first conduction part 3101 and the second conduction part 3102, and between the first conduction part 3101 and the signal connection part 320, showing a small contact resistance, enabling the protective metal part 212 and the signal connection part 320 to be conducted, so that the cathode layer 32 can receive the electrical signal in the signal terminal 21. Further, in the embodiment of the present invention, the first conduction part 3101 and the second conduction part 3102 can realize the conduction between the cathode layer 32 and the signal terminal 21. Furthermore, the same mask can be used to fabricate the cathode layer 32, the electron transport layer 311, and the electron injection layer 312, simplifying the process steps and reducing the cost. Since the electron transport layer 311, the electron injection layer 312, and the cathode layer 32 can be fabricated using the same mask 40, the coverage ranges of the electron transport layer 311, the electron injection layer 312, and the cathode layer 32 are the same. Furthermore, the distance between the signal terminal 21 and the display area 101 can be reduced to reduce the frame width of the display panel and achieve a narrow border of the display panel.

[0071] In other embodiments of the present invention, the difference from the previous embodiment is that the protective metal part 212 may not be provided in the display panel, that is, the signal terminal 21 only includes the signal transmission part 211, and the first conduction part 3101 is directly disposed on the surface of the signal transmission part 211 away from the substrate 10 side, and the Fermi level of the signal transmission part 211 is greater than the Fermi level of the first conduction part 3101.

[0072] In addition, when the signal transmission part 211 is formed by laminating a plurality of metal films, that is, the signal transmission part 211 includes a plurality of signal sub-parts arranged in a stacked manner, and the plurality of signal sub-parts include a first signal sub-part in contact with the first conduction part 3101, it is only necessary that the Fermi level of the first signal sub-part is greater than the Fermi level of the first conduction part 3101.

[0073] In addition, please refer to Figure 7 , Figure 8 and Figure 9 , embodiments of the present invention further provide a method for manufacturing a display panel. The display panel includes a display area 101 and a non-display area 102 adjacent to the display area 101. The method for manufacturing the display panel includes the following steps:

[0074] S10: Provide a substrate 10.

[0075] S20: Form a driving circuit layer 20 on the substrate 10. The driving circuit layer 20 includes signal terminals 21 formed in the non-display area 102.

[0076] Specifically, the driving circuit layer 20 includes an active layer 25 formed on the substrate 10 in sequence, a passivation layer 27 formed on the substrate 10 and covering the active layer 25, a gate 26 formed on the passivation layer 27, a gate insulating layer 28 formed on the passivation layer 27 and covering the gate 26, a source 221 and a drain 222 formed on the gate insulating layer 28, an interlayer dielectric layer 23 formed on the gate insulating layer 28 and covering the source 221 and the drain 222, and a planarization layer 24 formed on the interlayer dielectric layer 23. Among them, the active layer 25, the gate 26, the source 221, and the drain 222 are all disposed in the display area 101. The gate 26 is located above the active layer 25, and the source 221 and the drain 222 are respectively located on both sides above the active layer 25, and both pass through the gate insulating layer 28 and the passivation layer 27 and overlap with both sides of the active layer 25.

[0077] In the embodiments of the present invention, the driving circuit layer 20 further includes signal terminals 21. Among them, the signal terminals 21 include a signal transmission part 211 and a protective metal part 212 arranged in a stacked manner, and the signal transmission part 211 is located between the protective metal part 212 and the substrate 10.

[0078] The signal terminals 21 can be fabricated on the same layer as the source 221 and the drain 222, and the material of the signal terminals 21 can also be the same as that of the source 221 and the drain 222, such as copper or aluminum.

[0079] Among them, an opening is provided in the interlayer dielectric layer 23 corresponding to the signal terminal 21 to expose the upper surface of the protective metal part 212, and the protective metal part 212 covers the upper surface of the signal terminal 21 to prevent the signal terminal 21 from being oxidized and corroded, and the material of the protective metal part 212 can be molybdenum-titanium alloy; on the other hand, the protective metal part 212 has conductivity and does not affect the signal transmission of the signal terminal 21.

[0080] S30. A light-emitting functional layer 30 is formed on the side of the driving circuit layer 20 away from the substrate 10. The light-emitting functional layer 30 includes an electron transport layer 311 and a cathode layer 32 which are stacked. The electron transport layer 311 is formed in the display area 101 and extends to the non-display area 102. The electron transport layer 311 includes a first conduction part 3101 on the side of the signal terminal 21 away from the substrate 10. The cathode layer 32 is formed in the display area 101 and extends to the non-display area 102. The cathode layer 32 includes a signal connection part 320 on the side of the first conduction part 3101 away from the signal terminal 21. Among them, the Fermi level on the side of the signal terminal 21 close to the first conduction part 3101 is greater than the Fermi level of the first conduction part 3101, and the Fermi level of the first conduction part 3101 is greater than the Fermi level of the signal connection part 320.

[0081] Specifically, the light-emitting functional layer 30 includes a plurality of anodes 34 formed on the planar layer 24, a pixel definition layer 33 formed on the planar layer 24, a hole injection layer 35, a hole transport layer 36, and an organic light-emitting layer 37 formed on the pixel definition layer 33. Among them, the pixel definition layer 33 includes a plurality of pixel openings 330, and each pixel opening 330 corresponds to an anode 34 to expose a part of the upper surface of the corresponding anode 34. The hole injection layer 35, the hole transport layer 36, and the organic light-emitting layer 37 are stacked and continuously cover the plurality of pixel openings 330; further, in the embodiment of the present invention, the planar layer 24 and the pixel definition layer 33 form a lap hole 300 in the non-display area 102 to expose a part of the upper surface of the protective metal part 212, and the coverage boundaries of the hole injection layer 35, the hole transport layer 36, and the organic light-emitting layer 37 are all located on the side of the lap hole 300 close to the display area 101.

[0082] Then, an electron transport layer 311, an electron injection layer 312, and a cathode layer 32 are sequentially formed on the side of the organic light-emitting layer 37 away from the substrate 10 by using the same mask 40. And the electron injection layer 312 is located between the cathode layer 32 and the electron transport layer 311.

[0083] It should be noted that in other embodiments of the present invention, for example Figure 4 and Figure 5In the illustrated embodiment, the light-emitting functional layer 30 does not include an electron injection layer 312. Only an electron transport layer 311 is provided between the cathode layer 32 and the signal terminal 21. At this time, the same mask 40 can be used to sequentially form the electron transport layer 311 and the cathode layer 32 on the side of the organic light-emitting layer 37 away from the substrate 10.

[0084] It can be understood that since the electron transport layer 311, the electron injection layer 312, and the cathode layer 32 are formed using the same mask 40, in the embodiment of the present invention, the coverage ranges of the electron transport layer 311, the electron injection layer 312, and the cathode layer 32 are the same.

[0085] In the embodiment of the present invention, the electron transport layer 311 and the electron injection layer 312 are disposed in the display area 101 and extend into the non-display area 102. The electron transport layer 311 includes a first conduction portion 3101 on the side of the protective metal portion 212 away from the substrate 10, and the electron injection layer 312 includes a second conduction portion 3102 on the side of the first conduction portion 3101 away from the protective metal portion 212. The cathode layer 32 is disposed in the display area 101 and extends into the non-display area 102, and the cathode layer 32 includes a signal connection portion 320 on the side of the first conduction portion 3101 away from the signal transmission portion 211. That is, at the overlapping hole 300 corresponding to the display panel, the signal transmission portion 211, the protective metal portion 212, the first conduction portion 3101, the second conduction portion 3102, and the signal connection portion 320 are sequentially stacked from bottom to top.

[0086] Among them, the Fermi level of the protective metal portion 212 is greater than the Fermi level of the cathode layer 32, the Fermi level of the first conduction portion 3101 is greater than the Fermi level of the second conduction portion 3102, and the Fermi level of the second conduction portion 3102 is greater than the Fermi level of the signal connection portion 320. Therefore, at the contact interface between the protective metal portion 212 and the first conduction portion 3101, at the contact interface between the first conduction portion 3101 and the second conduction portion 3102, and at the contact interface between the second conduction portion 3102 and the signal connection portion 320, electrons migrate from the high-energy-level film layer to the low-energy-level film layer, and the electron migration barrier in this process is relatively low, so that good Ohmic contact can be achieved between the protective metal portion 212 and the first conduction portion 3101, between the first conduction portion 3101 and the second conduction portion 3102, and between the second conduction portion 3102 and the signal connection portion 320, showing a relatively small overlapping resistance, enabling conduction between the protective metal portion 212 and the signal connection portion 320, and enabling the cathode layer 32 to receive the electrical signal in the signal terminal 21.

[0087] In addition, an embodiment of the present invention further provides a display device, which includes the display panel described in the above embodiment and a device body, and the display panel and the device body are combined into one. Specifically, the device body may include a frame, a driving component, a power supply, etc.

[0088] In the above embodiments, the descriptions of the respective embodiments have their own emphases. For parts not detailed in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0089] The above has introduced in detail a display panel, a manufacturing method thereof, and a display device provided by an embodiment of the present invention. Specific examples are used herein to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the technical solution and its core idea of the present invention; those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A display panel, characterized in that, The display panel includes a display area and a non-display area adjacent to the display area, and the display panel further includes: a substrate; a driving circuit layer disposed on the substrate, the driving circuit layer including signal terminals disposed in the non-display area; a light-emitting functional layer disposed on a side of the driving circuit layer away from the substrate, the light-emitting functional layer including an electron transport layer and a cathode layer stacked, the electron transport layer being disposed in the display area and extending into the non-display area, the electron transport layer including a first conduction portion on a side of the signal terminal away from the substrate, the cathode layer being disposed in the display area and extending into the non-display area, the cathode layer including a signal connection portion on a side of the first conduction portion away from the signal terminal; wherein, a Fermi level on a side of the signal terminal close to the first conduction portion is greater than a Fermi level of the first conduction portion, and the Fermi level of the first conduction portion is greater than a Fermi level of the signal connection portion.

2. The display panel according to claim 1, characterized in that, The signal terminal includes a signal transmission portion and a protective metal portion, and the first conduction portion is disposed on a surface of the protective metal portion away from the signal transmission portion, and the Fermi level of the protective metal portion is greater than the Fermi level of the first conduction portion.

3. The display panel according to claim 1, characterized in that, The signal terminal includes a signal transmission portion, and the first conduction portion is disposed on a surface of the signal transmission portion away from the substrate; wherein, the signal transmission portion includes a plurality of stacked signal sub-portions, and the plurality of signal sub-portions include a first signal sub-portion in contact with the first conduction portion, and the Fermi level of the first signal sub-portion is greater than the Fermi level of the first conduction portion.

4. The display panel according to claim 1, characterized in that, The light-emitting functional layer further includes an electron injection layer disposed between the electron transport layer and the cathode layer, the electron injection layer being disposed in the display area and extending into the non-display area, the electron injection layer including a second conduction portion disposed between the first conduction portion and the signal connection portion; wherein, the Fermi level of the first conduction portion is greater than the Fermi level of the second conduction portion, and the Fermi level of the second conduction portion is greater than the Fermi level of the signal connection portion.

5. The display panel according to claim 4, characterized in that, The material of the electron transport layer and the material of the electron injection layer are each independently selected from at least one of an N-type doped organic semiconductor material, an organometallic complex material, and an organic semiconductor material.

6. The display panel according to claim 4, characterized in that, The Fermi level of the first conduction portion is greater than or equal to -5.5 eV and less than or equal to -3.5 eV, and the Fermi level of the second conduction portion is greater than or equal to -5.5 eV and less than or equal to -3.5 eV.

7. The display panel according to claim 4, characterized in that, The material of the electron transport layer and the material of the electron injection layer are each independently selected from at least one of a single metal material, an alloy material, a metal oxide material, and a metal salt material.

8. The display panel according to claim 4, characterized in that, The Fermi level of the first conduction portion gradually decreases in a direction away from the signal terminal, and the thickness of the first conduction portion is greater than or equal to 40 nanometers.

9. The display panel according to claim 4, characterized in that, The Fermi level of the second conduction portion gradually decreases in a direction away from the signal terminal, and the thickness of the second conduction portion is greater than or equal to 40 nanometers.

10. The display panel according to claim 1, characterized in that, The difference between the Fermi level of the first conduction part and the Fermi level of the signal connection part is less than or equal to 2 eV, and the difference between the Fermi level of the signal terminal on the side close to the first conduction part and the Fermi level of the first conduction part is less than or equal to 2 eV.

11. A method for manufacturing a display panel, characterized in that, The display panel includes a display area and a non-display area adjacent to the display area. The manufacturing method of the display panel includes the following steps: Provide a substrate; Form a driving circuit layer on the substrate. The driving circuit layer includes signal terminals formed in the non-display area; Form a light-emitting functional layer on the side of the driving circuit layer away from the substrate. The light-emitting functional layer includes an electron transport layer and a cathode layer stacked. The electron transport layer is formed in the display area and extends to the non-display area. The electron transport layer includes a first conduction part on the side of the signal terminal away from the substrate. The cathode layer is formed in the display area and extends to the non-display area. The cathode layer includes a signal connection part on the side of the first conduction part away from the signal terminal. Among them, the Fermi level of the signal terminal on the side close to the first conduction part is greater than the Fermi level of the first conduction part, and the Fermi level of the first conduction part is greater than the Fermi level of the signal connection part.

12. The method for manufacturing a display panel according to claim 11, characterized in that, The step of forming the light-emitting functional layer on the side of the driving circuit layer away from the substrate further includes the following steps: Use the same mask to sequentially form the electron transport layer and the cathode layer on the side of the driving circuit layer away from the substrate.

13. A display device, characterized in that, The display device includes the display panel according to any one of claims 1 to 10.

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