Display panel, display device and preparation method of display panel

Abstract

The application provides a display panel, a display device and a preparation method of the display panel. The display panel comprises: a substrate with an anode conductive layer; a plurality of pixel units arranged in an array on the substrate, the pixel units comprising a P-type semiconductor unit layer, a light-emitting unit layer and an electron transport unit layer, the light-emitting unit layer being located on the side of the P-type semiconductor unit layer away from the substrate, and the electron transport unit layer being located on the side of the light-emitting unit layer away from the P-type semiconductor unit layer; an electron transport film covering the substrate and the plurality of pixel units, the electron transport film being attached to the substrate and the plurality of pixel units; and a cathode conductive layer located on the side of the electron transport film away from the substrate. The technical scheme provided by the application can solve the problem of short circuit risk of the display panel in the related art.

Description

Technical Field

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

[0002] With the development of display technology, display devices using light-emitting diodes (LEDs) as light sources are increasingly appearing in people's lives, greatly changing their lifestyles. OLEDs (Organic Light-Emitting Diodes) possess characteristics such as self-illumination, high brightness, wide viewing angle, high contrast, flexibility, and low energy consumption, thus attracting widespread attention. As a new generation of display technology, they have begun to gradually replace traditional LCD displays and are widely used in mobile phone screens, computer monitors, full-color televisions, and more.

[0003] In related technologies, OLED functional layers generally include EIL (Electron Injection Layer), ETL (Electron Transport Layer), EML (Emissive Layer), HTL (Hole Transport Layer), and HIL (Hole Injection Layer). These functional layers are typically fabricated using vacuum evaporation. In a vacuum chamber, organic light-emitting materials are heated, and the substrate is masked using a photomask. Light-emitting materials are deposited on the pixels corresponding to RGB values. Then, the OLED pixel units are patterned using various processing techniques. Specifically, when evaporating the light-emitting materials on the RGB pixels, multiple photolithography and etching processes are required to remove the sacrificial layer.

[0004] However, after the sacrificial layer is stripped away, the electron transport layer in the OLED functional layer is exposed. During the cathode deposition, there is a possibility that the cathode and the hole injection layer may come into direct contact. Since the hole injection layer has strong conductivity, there is a possibility that the cathode potential and the anode potential may bypass the light-emitting unit layer and come into direct contact, which may lead to a short circuit risk. Summary of the Invention

[0005] In view of this, the present invention aims to provide a display panel, a display device, and a method for manufacturing a display panel, so as to solve the problem of short circuit risk in display panels.

[0006] The present invention provides a display panel, comprising: a substrate having an anode conductive layer; a plurality of pixel units arrayed on the substrate, the pixel units including a P-type semiconductor unit layer, a light-emitting unit layer and an electron transport unit layer, the light-emitting unit layer being located on the side of the P-type semiconductor unit layer away from the substrate, and the electron transport unit layer being located on the side of the light-emitting unit layer away from the P-type semiconductor unit layer; an electron transport film covering the substrate and the plurality of pixel units, the electron transport film being bonded to both the substrate and the plurality of pixel units; and a cathode conductive layer located on the side of the electron transport film away from the substrate.

[0007] In one embodiment, the electron transport film is made of an organic material with electron transport function; and / or, the thickness of the electron transport film is less than the thickness of the electron transport unit layer.

[0008] In one embodiment, the electron transport film includes multiple transport protrusions and multiple connecting films. Adjacent transport protrusions are connected by connecting films. Multiple pixel units extend into the multiple transport protrusions one by one. The sidewalls of the P-type semiconductor unit layer, the light-emitting unit layer, and the electron transport unit layer are respectively disposed opposite to the inner wall of the transport protrusion. The cathode conductive layer covers the side of the multiple transport protrusions and multiple connecting films away from the substrate.

[0009] In one embodiment, the display panel further includes an electron injection layer, with an electron film located between the electron transport film and the cathode conductive layer; and / or, the display panel further includes an encapsulation film located on the side of the cathode conductive layer away from the substrate; and / or, the pixel unit further includes a substrate, with a plurality of substrate arrays disposed on the substrate and a P-type semiconductor unit layer disposed on the corresponding substrate.

[0010] Another aspect of the present invention provides a display device, including the display panel provided above.

[0011] In another aspect, the present invention provides a method for manufacturing a display panel, comprising: obtaining a substrate; arraying and fabricating a plurality of pixel units of the display panel on the substrate; fabricating an electron transport film of the display panel, such that the electron transport film covers the substrate and the plurality of pixel units; and fabricating a cathode conductive layer of the display panel, such that the cathode conductive layer covers the electron transport film.

[0012] In one embodiment, fabricating multiple pixel units of a display panel on a substrate includes: using a sacrificial layer and photoresist, and employing photolithography and etching processes to fabricate multiple pixel units.

[0013] In one embodiment, a pixel unit includes a red sub-unit, a green sub-unit, and a blue sub-unit. Fabricating multiple pixel units using photolithography and etching processes includes: arraying multiple substrates of a display panel on a substrate; sequentially depositing a P-type semiconductor layer, a red light-emitting layer, and an electron transport layer on the substrate; sequentially coating a sacrificial layer and photoresist; transferring the pattern of a photomask onto the substrate using photolithography; stripping the P-type semiconductor layer, red light-emitting layer, electron transport layer, and sacrificial layer not protected by photoresist using etching to obtain a red sub-unit covered with photoresist; replacing the red light-emitting layer with a green light-emitting layer and a blue light-emitting layer, respectively, and repeating the above steps to obtain a green sub-unit covered with photoresist and a blue sub-unit covered with photoresist; and stripping the photoresist and sacrificial layer on the red, green, and blue sub-units using etching to obtain multiple pixel units.

[0014] In one embodiment, the electron transport film is prepared using a vapor deposition process.

[0015] In one embodiment, after preparing the cathode conductive layer of the display panel, the preparation method further includes: preparing an encapsulation layer on the cathode conductive layer.

[0016] According to the technical solution of this invention, the display panel includes a substrate, multiple pixel units, an electron transport film, and a cathode conductive layer. By covering the substrate and multiple pixel units with an electron transport film, and setting the cathode conductive layer on the side of the electron transport film away from the substrate, the electron transport film can isolate the multiple pixel units and the cathode conductive layer. This prevents the cathode conductive layer from contacting the pixel units, and thus from contacting the P-type semiconductor unit layer of the pixel units. This avoids the possibility of the anode conductive layer and the cathode conductive layer contacting each other through the P-type semiconductor unit layer, thereby preventing short circuits and ensuring the safety of the display panel operation. Attached Figure Description

[0017] Figure 1 The diagram shown is a structural schematic of the display panel provided in an embodiment of the present invention.

[0018] Figure 2 The diagram shows a flowchart of a method for manufacturing a display panel according to an embodiment of the present invention.

[0019] Figure 3 The diagram shown is a schematic diagram of the substrate array substrate in the display panel manufacturing process provided in an embodiment of the present invention.

[0020] Figure 4 The diagram shown is a schematic diagram of the substrate coating with a sacrificial layer and photoresist during the display panel fabrication process provided in an embodiment of the present invention.

[0021] Figure 5The diagram shown is a schematic of the red sub-unit covered with photoresist during the fabrication process of the display panel provided in an embodiment of the present invention.

[0022] Figure 6 The diagram shown is a schematic of a pixel unit covered with photoresist during the fabrication process of a display panel according to an embodiment of the present invention.

[0023] Figure 7 The diagram shown is a schematic diagram of the pixel unit after photoresist is stripped during the fabrication process of the display panel provided in an embodiment of the present invention.

[0024] Figure 8 The diagram shown is a schematic diagram of the electron transport film after evaporation during the manufacturing process of the display panel provided in an embodiment of the present invention.

[0025] Figure 9 The diagram shown is a schematic diagram of the cathode conductive layer after evaporation during the fabrication process of the display panel provided in an embodiment of the present invention.

[0026] Figure 10 The diagram shown is another structural schematic of the display panel provided in an embodiment of the present invention.

[0027] Figure 11 The figure shown is a graph showing the relationship between voltage and current density of the display panel in an embodiment of the present invention.

[0028] Figure 12 The figure shown is a graph showing the relationship between voltage and brightness of the display panel provided in an embodiment of the present invention.

[0029] Figure 13 The figure shown is a graph showing the relationship between the brightness and current efficiency of the display panel provided in an embodiment of the present invention.

[0030] Figure 14 The image shown is a spectral diagram of a display panel provided in an embodiment of the present invention. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] like Figure 1As shown, an embodiment of the present invention provides a display panel, which includes a substrate 10, a plurality of pixel units 20, an electron transport film 30, and an electron transport film 50. The substrate 10 has an anode conductive layer. The plurality of pixel units 20 are arrayed on the substrate 10. Each pixel unit 20 includes a P-type semiconductor unit layer 22, a light-emitting unit layer 23, and an electron transport unit layer 24. The light-emitting unit layer 23 is located on the side of the P-type semiconductor unit layer 22 away from the substrate 10, and the electron transport unit layer 24 is located on the side of the light-emitting unit layer 23 away from the P-type semiconductor unit layer 22. The electron transport film 30 covers the substrate 10 and the plurality of pixel units 20, and the electron transport film 30 is attached to both the substrate 10 and the plurality of pixel units 20. The cathode conductive layer 50 is located on the side of the electron transport film 30 away from the substrate 10.

[0033] According to the technical solution of this invention, the display panel includes a substrate 10, a plurality of pixel units 20, an electron transport film 30, and a cathode conductive layer 50. By covering the substrate 10 and the plurality of pixel units 20 with the electron transport film 30, and providing the cathode conductive layer 50 on the side of the electron transport film 30 away from the substrate 10, the plurality of pixel units 20 and the cathode conductive layer 50 can be isolated by the electron transport film 30. This prevents the cathode conductive layer 50 from contacting the pixel units 20, and thus prevents it from contacting the P-type semiconductor unit layer 22 of the pixel units 20. This avoids the possibility of the anode conductive layer and the cathode conductive layer 50 contacting each other through the P-type semiconductor unit layer 22, thereby preventing short circuits and ensuring the safety of the display panel operation.

[0034] In one specific embodiment, the P-type semiconductor cell layer 22 includes a hole transport cell layer 222 and a hole injection cell layer 221, with the hole transport cell layer 222 located between the anode conductive layer and the hole injection cell layer 221. The hole injection cell layer 221 has a low work function to lower the hole injection barrier and improve hole injection efficiency. The hole injection cell layer 221 facilitates the injection of holes from the anode conductive layer into the hole transport cell layer 222. Commonly used materials for the hole injection cell layer 221 include MoO3 and WO3. The hole transport cell layer 222 has a high hole mobility to ensure efficient hole transport and injection into the light-emitting layer. Commonly used materials for the hole transport cell layer 222 include NPB and TAPC.

[0035] In some specific embodiments, the P-type semiconductor cell layer 22 may also consist only of a hole transport layer.

[0036] The primary function of the electron transport layer is to transport electrons and inject them into the light-emitting layer. It needs to possess high electron mobility to ensure efficient electron transport. Commonly used materials for electron transport layers include TPBi and Bphen.

[0037] It should be noted that the pixel unit 20 in the display panel provided by the present invention is prepared by photolithography and etching processes. By performing photolithography and etching on the hole injection layer, hole transport layer, light emission layer and electron transport layer formed by vapor deposition, the hole injection unit layer 221, hole transport unit layer 222, light emission unit layer 23 and electron transport unit layer 24 of the pixel unit 20 can be formed.

[0038] In other embodiments, the functional film layers of the display panel can also be prepared using alternative processes such as inkjet printing, spin coating, spraying, dip coating, and atomic layer deposition.

[0039] In one specific embodiment, an isolation pillar is provided between each adjacent pixel unit 20. The isolation pillar can short-circuit between adjacent pixels, ensuring that each pixel can emit light independently. Commonly used materials for fabricating isolation pillars include insulating inorganic materials (such as silicon nitride, silicon carbide, and silicon oxide) and organic polymer materials (such as PI and polytetrafluoroethylene).

[0040] In related technologies, after the sacrificial layer is peeled off, some residue usually remains, obstructing the electron transport layer. Alternatively, the electron transport layer may be damaged due to the etching process used to peel off the sacrificial layer, resulting in an uneven surface. Since there is an inherent potential barrier between the cathode conductive layer 50 and the electron transport layer, this uneven surface further complicates the process, increasing the difficulty of electron injection. However, the display panel provided by this invention covers the pixel unit 20 with an electron transport film 30. This electron transport film 30 covers the electron transport unit layer 24 after the sacrificial layer has been peeled off, thereby covering its uneven surface. The smooth surface of the electron transport film 30 adheres to the cathode conductive layer 50, thus reducing the difficulty of electron injection.

[0041] In one specific embodiment, the electron transport membrane 30 is made of an organic material with electron transport function. Using this material enhances the electron transport function of the electron transport membrane 30.

[0042] Specifically, the material of the electron transport membrane 30 can be TPBi, Bphen, etc.

[0043] It should be noted that the material of the electron transport film 30 can be the same as or different from the material of the electron transport unit layer 24 of the pixel unit 20. Alternatively, provided that the materials are the same, the doping ratio of each component in the electron transport film 30 can be the same as or different from the doping ratio of each component in the electron transport unit layer 24.

[0044] The thickness of the electron transport film 30 is less than the thickness of the electron transport unit layer 24. By adopting this configuration, the thickness of the electron transport unit layer 24 can be made close to the thickness of the electron transport unit layer 24 of the pixel unit 20 in the display panel of the related art, thus not affecting the light emission effect of the pixel unit 20.

[0045] In one specific embodiment, the ratio between the thickness of the electron transport unit layer 24 of the display panel provided in this embodiment of the invention and the thickness of the electron transport unit layer 24 of the pixel unit 20 of the display panel in the related art is between 0.7 and 0.8. Correspondingly, the ratio between the thickness of the electron transport film 30 and the thickness of the electron transport unit layer 24 of the pixel unit 20 of the display panel in the related art is between 0.2 and 0.3. By adopting the above settings, the thickness of the manufactured pixel unit 20 can be made consistent with the thickness of the pixel unit 20 in the related art, thereby ensuring that the thickness of the display panel remains unchanged.

[0046] like Figure 1 As shown, the electron transport film 30 includes multiple transport protrusions 31 and multiple connecting films 32. Adjacent transport protrusions 31 are connected by connecting films 32. Multiple pixel units 20 extend into the multiple transport protrusions 31 one-to-one. The sidewalls of the P-type semiconductor unit layer 22, the light-emitting unit layer 23, and the electron transport unit layer 24 are respectively disposed opposite to the inner walls of the transport protrusions 31. The cathode conductive layer 50 covers the side of the multiple transport protrusions 31 and the multiple connecting films 32 away from the substrate 10. Using this structure, by placing the P-type semiconductor unit layer 22, the light-emitting unit layer 23, and the electron transport unit layer 24 of the pixel unit 20 within the transport protrusions 31, the transport protrusions 31 can effectively isolate the P-type semiconductor unit layer 22 and the cathode conductive layer 50, preventing direct contact between them and thus avoiding short circuits.

[0047] It should be noted that since the cathode conductive layer 50 covers the electron transport film 30, the structure of the cathode conductive layer 50 is the same as that of the electron transport film 30.

[0048] The connecting diaphragm 32 covers the corresponding isolation column.

[0049] In related technologies, the cathode conductive layer 50 is directly deposited after the sacrificial layer and photoresist 3 are peeled off. The cathode conductive layer 50 will come into contact with the sides of the pixel unit 20, specifically with the sides of the P-type semiconductor unit layer 22, the light-emitting unit layer 23, and the electron transport unit layer 24, potentially leading to a short circuit. However, in this embodiment, the cathode conductive layer 50 and the sides of the P-type semiconductor unit layer 22 are isolated by the electron transport film 30, thus preventing short circuits.

[0050] like Figure 1 As shown, the display panel also includes an electron injection layer 40, with the electron film located between the electron transport film 30 and the cathode conductive layer 50. The electron injection layer 40 facilitates the injection of electrons from the cathode into the electron transport layer.

[0051] The electron injection layer 40 needs to have a low work function to reduce the electron injection barrier and improve the electron injection efficiency. Commonly used materials for the electron injection layer 40 include LiF and CsF.

[0052] like Figure 10 As shown, the display panel also includes an encapsulation layer 60, which is located on the side of the cathode conductive layer 50 away from the substrate 10. The encapsulation layer 60 encapsulates the display panel, preventing moisture and oxygen from corroding the organic light-emitting materials, thus protecting the internal structure of the OLED device, preventing physical damage and chemical corrosion, and extending the device's lifespan.

[0053] In some specific embodiments, the encapsulation layer 60 can be made of inorganic materials, organic materials, or composite materials. Of course, the encapsulation method can also employ one of various mature encapsulation processes.

[0054] like Figure 3 and Figure 5 As shown, the pixel unit 20 also includes a substrate 21, with an array of substrates 21 disposed on the substrate 10, and a P-type semiconductor unit layer 22 disposed on the corresponding substrate 21. The substrate 21 can support the various functional film layers of the display panel, providing mechanical and thermal stability to each functional film layer.

[0055] For flexible OLEDs, commonly used substrate materials include polyimide (PI) and polyethylene terephthalate (PET).

[0056] Based on the same inventive concept, another embodiment of the present invention provides a display device, including the display panel provided above. By covering the substrate 10 and the plurality of pixel units 20 with an electron transport film 30, and providing a cathode conductive layer 50 on the side of the electron transport film 30 away from the substrate 10, the electron transport film 30 can isolate the plurality of pixel units 20 and the cathode conductive layer 50, so that the cathode conductive layer 50 will not contact the pixel units 20, and therefore will not contact the P-type semiconductor unit layer 22 of the pixel units 20. This avoids the possibility of the anode conductive layer and the cathode conductive layer 50 contacting each other through the P-type semiconductor unit layer 22, thereby preventing short circuits and ensuring the safety of the display panel operation.

[0057] In embodiments of the present invention, the electronic device may include a mobile phone, tablet computer, smart wearable device, television, laptop computer, monitor, or other device with display function. The present invention does not impose specific limitations on the specific form of the electronic device.

[0058] Since the principle of solving the problem in the electronic device embodiment is similar to that in the above-described display module embodiment, the implementation of the electronic device embodiment can refer to the implementation of the above-described display module embodiment, and the repeated parts will not be described again.

[0059] like Figure 2 As shown, based on the same inventive concept, another embodiment of the present invention provides a method for preparing a display panel, which is used to prepare the display panel provided above. The preparation method includes the following steps.

[0060] S1. Obtain a substrate and fabricate multiple pixel units of a display panel on the substrate in an array.

[0061] S2. Prepare the electron transport film for the display panel, so that the electron transport film covers the substrate and multiple pixel units.

[0062] S3. Prepare the cathode conductive layer of the display panel, so that the cathode conductive layer covers the electron transport film.

[0063] Through the above preparation method, in step S1, by arraying multiple pixel units on the substrate, a functional layer for each pixel unit can be formed on the substrate. This allows holes from the anode conductive layer to be transported to the light-emitting unit layer via the P-type semiconductor layer, and electrons to be transported to the light-emitting unit layer via the electron transport unit layer, enabling the light-emitting unit layer to function normally. Figure 8 As shown, in step S2, by preparing an electron transport film, electrons can be transported to the electron transport unit layer. Furthermore, since the electron transport film covers the substrate and multiple pixel units, it can isolate the P-type semiconductor unit layer and the cathode conductive layer, thereby preventing the anode conductive layer and the cathode conductive layer from contacting through the P-type semiconductor unit layer, and thus avoiding short circuits. Figure 9 As shown, in step S3, by preparing the cathode conductive layer, electrons can be transferred to the light-emitting layer in conjunction with the electron injection layer and the electron transport layer.

[0064] In step S1, the fabrication of multiple pixel units for a display panel on the substrate includes: S11, using a sacrificial layer and photoresist, and employing photolithography and etching processes to fabricate multiple pixel units. The above-described process for fabricating pixel units has the advantages of mature technology and high product yield.

[0065] It should be noted that the sacrificial layer includes a first sacrificial layer 1 and a second sacrificial layer 2. The second sacrificial layer 2 is located between the first sacrificial layer 1 and the photoresist 3. The first sacrificial layer 1, the second sacrificial layer 2, and the photoresist 3 are all temporary materials used in the display panel manufacturing process and do not exist in the final product. Therefore, these three layers need to be peeled off before the final product is formed. The first sacrificial layer 1 can be made of resin adhesive, which isolates the pixel units from the second sacrificial layer 2. The second sacrificial layer 2 can be an inorganic layer, which isolates moisture and oxygen.

[0066] In the fabrication of the pixel unit, each functional layer is formed using a vapor deposition process under vacuum conditions. During the photolithography process, the exposure and development processes using a photomask are carried out under atmospheric conditions. Therefore, a second sacrificial layer 2 is required to isolate moisture and oxygen.

[0067] In one specific embodiment, similar to the fabrication method of a display panel in the related art, the photoresist 3 and the second sacrificial layer 2 are removed by a dry etching process, and the first sacrificial layer 1 is removed by a wet etching process.

[0068] Furthermore, in related technologies, after all sacrificial layers and photoresist 3 are peeled off, the electron transport unit layer of the pixel unit is exposed. At this point, if the electron injection layer and cathode conductive layer are directly deposited using a vapor deposition process, there is a risk of direct side contact between the cathode conductive layer and the P-type semiconductor unit layer, leading to a short circuit. Simultaneously, since the first sacrificial layer 1 is peeled off using a wet process and is in direct contact with the electron transport unit layer, the materials used during the peeling process can corrode the electron transport unit layer, causing damage. Additionally, some parts of the first sacrificial layer 1 may not be peeled off by the peeling material, resulting in residue.

[0069] The pixel unit includes red sub-units, green sub-units, and blue sub-units, such as... Figure 6 and Figure 7 As shown, the three sub-units represent the red sub-unit, the green sub-unit, and the blue sub-unit, respectively.

[0070] In step S11, the fabrication of multiple pixel units using photolithography and etching processes includes the following steps.

[0071] S111, Multiple substrates of a display panel are arrayed on a substrate.

[0072] S112. A P-type semiconductor layer, a red light-emitting layer, and an electron transport layer are sequentially deposited on the substrate.

[0073] S113, sequentially coat the sacrificial layer and photoresist.

[0074] S114. The pattern of the photomask is transferred to the substrate using photolithography, and the P-type semiconductor layer, red light-emitting layer, electron transport layer and sacrificial layer that are not protected by photoresist are removed using etching to obtain the red sub-unit covered by photoresist.

[0075] S115. Replace the red light-emitting layer with a green light-emitting layer and a blue light-emitting layer respectively, and repeat the above steps to obtain a green sub-unit covered with photoresist and a blue sub-unit covered with photoresist.

[0076] S116. Using an etching process, the photoresist and sacrificial layer on the red sub-unit, the green sub-unit, and the blue sub-unit are removed to obtain multiple pixel units.

[0077] By following the steps above, such as Figure 3 As shown, in step S111, by arraying multiple substrates on a substrate, support can be provided for each functional layer of the pixel unit. Figure 4 As shown, in step S112, by sequentially depositing each functional layer, the substrate conditions for forming each functional unit layer of the pixel unit can be achieved. In step S113, a sacrificial layer is used to isolate moisture and oxygen, thus protecting each functional layer. Using photoresist as an anti-etching layer protects the underlying material from etching during subsequent photolithography processes. Figure 5 As shown, in step S114, a pixel pattern can be formed through photolithography. After photoresist coating, the photolithography process also includes exposure and development steps. During development, the exposed photoresist protects each functional layer, forming the desired pattern, while the unexposed areas of photoresist are dissolved. Through etching, the functional layers and sacrificial layers in areas lacking pixel units can be peeled off to expose the substrate and slab, providing conditions for subsequent pixel unit fabrication and forming red sub-units covered with photoresist. Figure 6 As shown, in step S115, by replacing the red light-emitting layer with a green light-emitting layer and a blue light-emitting layer respectively, green sub-units and blue sub-units covered with photoresist can be formed respectively. Figure 7 As shown, in step S116, by peeling off the photoresist and sacrificial layer on the pixel unit, multiple pixel units with red sub-units, green sub-units and blue sub-units can be formed on the substrate.

[0078] Among them, the P-type semiconductor layer, the red light-emitting layer, and the electron transport layer are collectively referred to as OLED functional layer 4.

[0079] The electron transport film is prepared using a vapor deposition process. This process offers advantages such as mature technology and high product yield.

[0080] like Figure 2As shown, after step S3 of preparing the cathode conductive layer of the display panel, the preparation method further includes the following steps.

[0081] S4. Prepare an encapsulation layer on the cathode conductive layer.

[0082] like Figure 10 As shown, through step S4, the display panel can be encapsulated using an encapsulation layer to isolate moisture and oxygen, thus protecting the pixel units.

[0083] The following description compares the display panels in related technologies with the display panel provided in the embodiments of the present invention:

[0084] Both the display panel in the related technology and the display panel in the embodiment of the present invention include a hole blocking layer. The hole blocking layer is located between the electron transport layer and the light-emitting layer, and can prevent holes from entering the light-emitting layer from the anode or the hole transport layer, thereby improving the luminous efficiency and stability of the device.

[0085] In an embodiment of the present invention, the electron transport film of the display panel is left to stand in the atmosphere for 60 minutes and then baked at 90°C for 60 minutes.

[0086] It should be noted that each different film layer can be made of a single material or a composite of two or more materials. For example, the hole transport layer is made of EB material with a thickness of 350 Å. The electron transport film is made of ET1 with a thickness of 36 Å and ET2 with a thickness of 24 Å.

[0087] Table 1

[0088]

[0089] As shown in Table 1 above, Table 1 presents the IVL data of the green sub-unit under a brightness condition of 15000 nits, obtained using IVL testing equipment. In the table, D1 represents the display panel in the related art, and D2 represents the display panel of this embodiment. As can be seen from the table, the display panel of this embodiment has a voltage reduction of approximately 1V and a current efficiency increase of approximately 15cd / A compared to the display panels in the related art.

[0090] In this diagram, CIE-x and CIE-y are the x and y coordinates, respectively, in the CIE1931 chromaticity diagram, used to describe the chromaticity of a color. The Main Peak refers to the wavelength position with the highest intensity in the spectrum.

[0091] In spectroscopy, the width of a spectral line (FWHM) is used to describe the width of the spectral line. It can be used to analyze information such as the shape, peak position, and peak intensity of the spectral line. The higher the resolution of the spectrometer, the smaller the FWHM of the measured spectral line, meaning that more subtle spectral features can be resolved.

[0092] like Figure 11 As shown, Figure 11 The diagram shows voltage and current density graphs for display panels in related technologies and display panels according to embodiments of the present invention. Figure 11 It can be seen that, under the same voltage, the current density of D2 is significantly greater than that of D1. It should be noted that... Figure 11 The three curves at the top represent three tests on D2, while the two curves at the bottom represent two tests on D1.

[0093] Wherein, D1 represents the display panel in the related art, and D2 represents the display panel in the embodiment of the present invention.

[0094] like Figure 12 As shown, Figure 12 The diagram shows voltage and brightness curves for a display panel in the related art and a display panel according to an embodiment of the present invention. Figure 12 It can be seen that, under the same voltage, the brightness of D2 is significantly greater than that of D1. It should be noted that... Figure 12 The three curves at the top represent three tests on D2, while the two curves at the bottom represent two tests on D1.

[0095] like Figure 13 As shown, Figure 13 The diagram shows graphs illustrating the brightness and current efficiency of display panels in related technologies and display panels according to embodiments of the present invention. Figure 12 It can be seen that, under the same brightness, the current efficiency of D2 is significantly greater than that of D1. It should be noted that... Figure 13 The two curves at the top represent two tests conducted on D2, while the two curves at the bottom represent two tests conducted on D1. Since the test results are quite similar, the two test curves for D1 are almost identical.

[0096] like Figure 14 As shown, Figure 14 The spectral diagrams of a display panel in the related art and a display panel according to an embodiment of the present invention are shown. Figure 13 It can be seen that the spectra of D1 and D2 are almost identical, and the difference between them is not significant.

[0097] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A display panel, characterized in that, include: The substrate has an anodic conductive layer; Multiple pixel units are arrayed on the substrate. Each pixel unit includes a P-type semiconductor unit layer, a light-emitting unit layer, and an electron transport unit layer. The light-emitting unit layer is located on the side of the P-type semiconductor unit layer away from the substrate, and the electron transport unit layer is located on the side of the light-emitting unit layer away from the P-type semiconductor unit layer. An electron transport film is covered on the substrate and the plurality of pixel units, and the electron transport film is bonded to both the substrate and the plurality of pixel units. A cathode conductive layer is located on the side of the electron transport film away from the substrate.

2. The display panel according to claim 1, characterized in that, The electron transport membrane is made of an organic material with electron transport function; and / or, The thickness of the electron transport film is less than the thickness of the electron transport unit layer.

3. The display panel according to claim 1, characterized in that, The electron transport film includes multiple transport protrusions and multiple connecting films. Adjacent transport protrusions are connected by the connecting films. Multiple pixel units extend into the multiple transport protrusions one by one. The sidewalls of the P-type semiconductor unit layer, the light-emitting unit layer, and the electron transport unit layer are respectively disposed opposite to the inner walls of the transport protrusions. The cathode conductive layer covers the side of the multiple transport protrusions and the multiple connecting films away from the substrate.

4. The display panel according to claim 1, characterized in that, The display panel further includes an electron injection layer, wherein the electron film is located between the electron transport film and the cathode conductive layer; and / or, The display panel further includes an encapsulation layer located on the side of the cathode conductive layer away from the substrate; and / or, The pixel unit further includes a substrate, and a plurality of the substrate arrays are disposed on the substrate, and the P-type semiconductor unit layer is disposed on the corresponding substrate.

5. A display device, characterized in that, The display panel includes any one of claims 1 to 4.

6. A method for manufacturing a display panel, characterized in that, include: Obtain a substrate, and array and fabricate a plurality of pixel units of the display panel on the substrate; An electron transport film is prepared for the display panel, such that the electron transport film covers the substrate and the plurality of pixel units; Prepare a cathode conductive layer for the display panel, such that the cathode conductive layer covers the electron transport film.

7. The method for manufacturing a display panel according to claim 6, characterized in that, The process of arraying multiple display panel pixel units on the substrate includes: using a sacrificial layer and photoresist, and employing photolithography and etching processes to fabricate multiple pixel units.

8. The method for manufacturing a display panel according to claim 7, characterized in that, The pixel unit includes a red sub-unit, a green sub-unit, and a blue sub-unit. The fabrication of the pixel unit using photolithography and etching processes includes: A plurality of substrates for the display panel are arrayed on the substrate; A P-type semiconductor layer, a red light-emitting layer, and an electron transport layer are sequentially deposited on the substrate. The sacrificial layer and the photoresist are coated sequentially; The pattern of the photomask is transferred onto the substrate using a photolithography process, and the P-type semiconductor layer, the red light-emitting layer, the electron transport layer, and the sacrificial layer that are not protected by the photoresist are removed using an etching process to obtain a red subunit covered with photoresist. The red light-emitting layer was replaced with a green light-emitting layer and a blue light-emitting layer, respectively, and the above steps were repeated to obtain a green sub-unit covered with photoresist and a blue sub-unit covered with photoresist. The photoresist and sacrificial layer on the red sub-unit, the green sub-unit, and the blue sub-unit are removed by an etching process to obtain a plurality of pixel units.

9. The method for manufacturing a display panel according to claim 6, characterized in that, The electron transport film is prepared using a vapor deposition process.

10. The method for manufacturing a display panel according to claim 6, characterized in that, After preparing the cathode conductive layer of the display panel, the preparation method further includes: An encapsulation layer is prepared on the cathode conductive layer.

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