Display panel and preparation method thereof

Abstract

This application discloses a display panel and its fabrication method. The display panel includes: a substrate; a pixel defining layer disposed on the substrate and defining a plurality of first openings; a first electrode located in the first openings; a plurality of light-emitting units disposed in the first openings and located on the side of the first electrode away from the substrate, the light-emitting units including quantum dot light-emitting units and organic light-emitting units disposed in the same layer; an electron transport layer disposed in the first openings and located on the side of the light-emitting units away from the first electrode; and a second electrode disposed on the side of the electron transport layer away from the light-emitting units. The electron transport layer includes an inorganic electron transport layer and an organic electron transport layer, the inorganic electron transport layer covering the quantum dot light-emitting units, and the organic electron transport layer covering the organic light-emitting units.

Description

Technical Field

[0001] This application relates to the field of display technology, specifically to a display panel and its manufacturing method. Background Technology

[0002] Currently, in quantum dot display panels, the luminous efficiency of blue sub-pixels prepared using quantum dot luminescent materials is relatively poor. The industry often uses organic luminescent materials to prepare the luminescent units in blue sub-pixels.

[0003] Correspondingly, an organic electron transport layer with an energy level matching that of the organic light-emitting material is set in the blue sub-pixel. To reduce costs, the organic electron transport layer is formed by open mask evaporation, allowing it to cover the entire display area of ​​the display panel. Specifically, the organic electron transport layer covers the inorganic electron transport layer in the red and green sub-pixels and cannot be effectively removed, resulting in a decrease in the luminous efficiency of the red and green sub-pixels. Summary of the Invention

[0004] This application provides a display panel and its manufacturing method to improve the reduced luminous efficiency of red and green sub-pixels in existing display panels.

[0005] This application provides a display panel, comprising: a substrate; a pixel defining layer disposed on the substrate and defining a plurality of first openings; a first electrode located in the first openings; a plurality of light-emitting units disposed in the first openings and located on the side of the first electrode away from the substrate, the light-emitting units including quantum dot light-emitting units and organic light-emitting units disposed in the same layer; an electron transport layer disposed in the first openings and located on the side of the light-emitting units away from the first electrode; and a second electrode disposed on the side of the electron transport layer away from the light-emitting units; wherein the electron transport layer includes an inorganic electron transport layer and an organic electron transport layer, the inorganic electron transport layer covering the quantum dot light-emitting units, and the organic electron transport layer covering the organic light-emitting units.

[0006] Optionally, in some embodiments of this application, the display panel further includes: an auxiliary electrode, wherein a plurality of second openings are provided on the pixel defining layer, the auxiliary electrode is disposed in the second opening, and the second electrode extends into the second opening and is electrically connected to the auxiliary electrode.

[0007] Optionally, in some embodiments of this application, the quantum dot light-emitting unit includes a first sub-quantum dot light-emitting unit and a second sub-quantum dot light-emitting unit disposed in the same layer, wherein the first sub-quantum dot light-emitting unit, the second sub-quantum dot light-emitting unit, and the organic light-emitting unit are respectively disposed in a one-to-one correspondence with the first opening.

[0008] Optionally, in some embodiments of this application, the light emitted by the first sub-quantum dot light-emitting unit is red light, the light emitted by the second sub-quantum dot light-emitting unit is green light, and the light emitted by the organic light-emitting unit is blue light.

[0009] Optionally, in some embodiments of this application, the first electrode is an anode, the second electrode is a cathode, and / or the organic electron transport layer extends to the end face of the pixel defining layer.

[0010] This application provides a method for manufacturing a display panel, including:

[0011] Provide substrate;

[0012] A pixel defining layer is formed on the substrate, the pixel defining layer defining a plurality of first openings;

[0013] A first electrode is formed within the first opening;

[0014] A light-emitting unit is formed on the first electrode, the light-emitting unit including a quantum dot light-emitting unit and an organic light-emitting unit disposed in the same layer;

[0015] An inorganic electron transport layer is formed on the quantum dot light-emitting unit;

[0016] An organic electron transport layer is deposited on the organic light-emitting unit by vapor deposition;

[0017] Remove the organic electron transport layer from the inorganic electron transport layer to expose the surface of the inorganic electron transport layer;

[0018] A second electrode is formed on the inorganic electron transport layer and the organic electron transport layer.

[0019] Optionally, in some embodiments of this application, after the step of forming an inorganic electron transport layer on the quantum dot light-emitting unit and before the step of depositing an organic electron transport layer on the organic light-emitting unit, the method further includes: forming a magnetic material layer on the inorganic electron transport layer.

[0020] Optionally, in some embodiments of this application, the step of removing the organic electron transport layer from the inorganic electron transport layer to expose the surface of the inorganic electron transport layer includes:

[0021] A magnetic element is used to adsorb the magnetic material layer, thereby separating the organic electron transport layer on the magnetic material layer and the magnetic material layer together from the first opening.

[0022] Optionally, in some embodiments of this application, the step of forming a magnetic material layer on the inorganic electron transport layer includes:

[0023] Magnetic ink is disposed within the first opening by inkjet printing, the magnetic ink comprising a material that can be attracted by the magnetic element;

[0024] The substrate printed with magnetic ink is subjected to vacuum drying and annealing baking processes in sequence to form the magnetic material layer.

[0025] Optionally, in some embodiments of this application, the magnetic element includes a rotating portion and a scraping portion, the rotating portion having a rotatable magnetic surface, the magnetic surface being opposite to the organic electron transport layer by the rotation of the rotating portion; the scraping portion is disposed on the rotation path of the rotating portion;

[0026] The step of using a magnetic element to adsorb the magnetic material layer includes:

[0027] The magnetic surface adsorbs the magnetic material layer, causing the organic electron transport layer and the magnetic material layer located above the magnetic material layer to detach together from the first opening, thereby exposing the inorganic electron transport layer.

[0028] Rotate the rotating part to move the magnetic element from one end of the substrate to the other end of the substrate;

[0029] The scraping section removes the magnetic material layer and the organic electron transport layer adsorbed on the magnetic surface.

[0030] The display panel provided in this application includes an inorganic quantum dot light-emitting unit and an organic light-emitting unit. The first quantum dot light-emitting unit is covered by a first inorganic electron transport layer, and the organic light-emitting unit is covered by an organic electron transport layer, so as to ensure that the energy level of the light-emitting unit matches the corresponding electron transport layer, thereby effectively improving the luminous efficiency of the light-emitting unit. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1This is a cross-sectional view of the display panel provided in this application;

[0033] Figures 2A to 2I This is a schematic diagram of the structure of the display panel at each stage in the manufacturing method of the display panel provided in this application.

[0034] Explanation of icon numbers:

[0035] 1: Substrate; 2: Pixel defining layer; 21: First opening; 22: Second opening; 3: First electrode; 41: Hole injection layer; 42: Hole transport layer; 43a: First sub-quantum dot light-emitting unit; 43b: Organic light-emitting unit; 43c: Second sub-quantum dot light-emitting unit; 44a: First inorganic electron transport layer; 44b: Organic electron transport layer; 44c: Second inorganic electron transport layer; 5: Second electrode; 6: Auxiliary electrode; 7: Magnetic material layer; 8: Magnetic element; 81: Rotating part; 82: Scraping part; 83: Magnetic surface. Detailed Implementation

[0036] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. In addition, it should be understood that the specific embodiments described herein are only for illustration and explanation of this application and are not intended to limit this application. In this application, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0037] This application provides a display panel; please refer to... Figure 1The display panel includes: a substrate 1, a pixel defining layer 2, a first electrode 3, multiple light-emitting units (43a, 43b, 43c as shown in the figure), an electron transport layer (44a, 44b, 44c as shown in the figure), and a second electrode 5. The pixel defining layer 2 is disposed on the substrate 1. The pixel defining layer 2 defines multiple first openings 21. The first electrode 3 is located in the first openings 21. The light-emitting units are disposed in the first openings 21. The light-emitting units are located on the side of the first electrode 3 away from the substrate 1. The light-emitting units include quantum dot light-emitting units (43a, 43c as shown in the figure) and organic light-emitting units 43b disposed in the same layer. The electron transport layer is disposed in the first openings 21. The electron transport layer is located on the side of the light-emitting units away from the first electrode 3. The second electrode 5 is disposed on the side of the electron transport layer away from the light-emitting units. The electron transport layer includes an inorganic electron transport layer (44a, 44c as shown in the figure) and an organic electron transport layer 44b. The inorganic electron transport layer covers the quantum dot light-emitting units. The organic electron transport layer covers the organic light-emitting units.

[0038] Substrate 1 includes a substrate (not shown in the figure) and a thin-film transistor functional layer (not shown in the figure) disposed on the substrate. The substrate may be a flexible substrate. The material of the flexible substrate may be one or more of polyethersulfone, polyacrylate, polyimide, polyethylene naphthalate, and polyethylene terephthalate. In some specific embodiments of this application, the substrate may also be a rigid substrate, and the material of the rigid substrate may be glass; this application does not specifically limit this.

[0039] The pixel defining layer 2 has a plurality of first openings 21. The pixel defining layer 2 can be made of a hydrophobic organic photoresist material. The organic photoresist material can be one or more of polyimide, polyethylene naphthalate, polyethylene terephthalate, polycarbonate, polyetherimide, polyethersulfone, or benzocyclobutene.

[0040] The first electrode 3 is disposed within the first opening 21. The first opening 21 exposes the first electrode 3. In this embodiment, the first electrode 3 is the anode. The first electrode 3 can be a three-layer conductive structure of ITO / Ag / ITO, or a two-layer conductive structure of Ag / ITO, Al / WOx, or Ag / IZO. In some specific embodiments, the first electrode 3 can also be a single-layer conductive structure. Specifically, the material of the first electrode 3 can include one or more of conductive metals or alloys composed of conductive metals such as Mo, Al, Ti, Nd, or Cu, or one or more of conductive oxides such as indium gallium zinc oxide (IGZO), indium zinc tin oxide (IZTO), indium gallium zinc tin oxide (IGZTO), indium tin oxide (ITO), indium zinc oxide (IZO), indium aluminum zinc oxide (IAZO), indium gallium tin oxide (IGTO), or antimony tin oxide (ATO).

[0041] The light-emitting unit is disposed on the first electrode 3 exposed by the first opening 21. The light-emitting unit can be a single-layer structure or a multilayer structure composed of two or more film layers. The materials of different sub-light-emitting units in the light-emitting unit can be different. The light-emitting unit includes quantum dot light-emitting units (43a and 43c shown in the figure) and organic light-emitting units 43b disposed in the same layer.

[0042] The display panel also includes a hole injection layer 41 and a hole transport layer 42 sequentially stacked between the first electrode 3 and the light-emitting unit. The hole injection layer 41 is disposed facing the first electrode 3. The material of the hole injection layer 41 can be a conductive polymer material or its derivatives. The conductive polymer material can include polythiophene or polyaniline. The thickness of the hole injection layer 41 can be between 10 nanometers and 60 nanometers.

[0043] The hole transport layer 42 can be made of organic materials, such as one or more of polytriphenylamine, 9,9-dioctylfluorene / N-(4-sec-butylphenyl)-diphenylamine alternating copolymer (TFB) or N,N′-bis(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine (NPB), or inorganic materials, such as copper oxide (Cu2O) or copper gallium oxide nanoparticles (CuxGa1-xO).

[0044] The electron transport layer serves two main purposes: first, it forms a small potential barrier with the cathode to facilitate electron injection; second, it effectively blocks holes to prevent leakage current. The material of the electron transport layer must ensure that its lowest unoccupied molecular orbital (LUMO) energy level matches the work function of the cathode, while also possessing high electron mobility to enable effective electron injection.

[0045] Organic electron transport materials have poor thermal stability and are easily degraded in oxygen and humid environments. Therefore, they are generally not prepared using solution methods and are mostly formed by vapor deposition. The electron mobility of organic electron transport materials is typically 10-1. -6 Up to 10 -4 cm 2 / (V·s), with poor transmission capability.

[0046] Taking wide-bandgap metal oxide semiconductors such as ZnO, TiO2, and SnO2 as examples, the thermal stability and corrosion resistance of commonly used inorganic electron transport materials are far superior to those of organic electron transport materials. The electron mobility of inorganic electron transport materials is also significantly higher than that of organic electron transport materials. For instance, the electron mobility of zinc oxide is 2 × 10⁻⁶. -3 cm 2 / (V·s).

[0047] In light-emitting display panels, an imbalance between electron and hole injection can cause leakage current in the device. Excess electrons can also charge quantum dots, leading to non-radiative Auger recombination and fluorescence quenching. To improve this situation, it is necessary to improve the hole transport efficiency and match the energy levels of the materials of the hole transport layer 42, the light-emitting unit, and the electron transport layer to ensure display quality.

[0048] The second electrode 5 is disposed on the light-emitting film layer group 4. The second electrode 5 is connected to the light-emitting unit within the first opening 21. In this embodiment, the second electrode 5 is a cathode covering the display area. The second electrode 5 is made of a transparent conductive material. The second electrode 5 is directly connected to the electron transport layer.

[0049] The display panel includes multiple light-emitting units arranged in an array.

[0050] Specifically, such as Figure 1 As shown, the light-emitting unit includes quantum dot light-emitting units and organic light-emitting units 43b arranged in the same layer. The quantum dot light-emitting unit includes a first quantum dot light-emitting unit 43a and a second quantum dot light-emitting unit 43c. The electron transport layer includes an inorganic electron transport layer and an organic electron transport layer 44b. The inorganic electron transport layer includes a first inorganic electron transport layer 44a and a second inorganic electron transport layer 44c.

[0051] The first quantum dot light-emitting unit 43a is connected to the first inorganic electron transport layer 44a. The first quantum dot light-emitting unit 43a comprises quantum dot material. The first inorganic electron transport layer 44a comprises inorganic electron transport material, such that the energy levels of the material in the first quantum dot light-emitting unit 43a are matched with the energy levels of the material in the first inorganic electron transport layer 44a, thereby improving the luminous efficiency of the first quantum dot light-emitting unit 43a. Specifically, the first inorganic electron transport layer 44a can be an inorganic composite material doped with a nano-noble metal core-shell structure, such as one or more of zinc oxide, zinc magnesium oxide, zinc aluminum oxide, or zinc magnesium lithium oxide.

[0052] Organic light-emitting unit 43b and organic electron transport layer 44b are disposed opposite to each other. A second electrode 5 is disposed on organic electron transport layer 44b. Organic electron transport layer 44b extends to the end face of pixel defining layer 2. Organic electron transport layer 44b covers at least a portion of the end face of pixel defining layer 2. Organic light-emitting unit 43b includes organic light-emitting material. Organic electron transport layer 44b includes organic electron transport material such that the energy level of the material of organic light-emitting unit 43b matches the energy level of the material of organic electron transport layer 44b to maintain the luminous efficiency of organic light-emitting unit 43b. Specifically, organic electron transport layer 44b can be aluminum octahydroxyquinoline.

[0053] The second quantum dot light-emitting unit 43c is connected to the second inorganic electron transport layer 44c. The second quantum dot light-emitting unit 43c includes quantum dot material. The second inorganic electron transport layer 44c includes inorganic electron transport material, such that the energy levels of the material in the second quantum dot light-emitting unit 43c are matched with the energy levels of the material in the second inorganic electron transport layer 44c, thereby improving the luminous efficiency of the second quantum dot light-emitting unit 43c. Specifically, the second inorganic electron transport layer 44c can be an inorganic composite material doped with a nano-noble metal core-shell structure, such as one or more of zinc oxide, zinc magnesium oxide, zinc aluminum oxide, or zinc magnesium lithium oxide.

[0054] It is understandable that the second inorganic electron transport layer 44c can be made of the same material as the first inorganic electron transport layer 44a, so as to be fabricated in the same process, thereby simplifying the preparation process of the electron transport layer.

[0055] Therefore, the quantum dot light-emitting unit uses an electron transport layer 44 made of inorganic electron transport material, and the organic light-emitting unit uses an organic electron transport layer 44b made of organic electron transport material. This design effectively achieves energy level matching between the material of the light-emitting unit and the material of the corresponding electron transport layer 44.

[0056] Because the electron mobility of organic electron transport materials is much lower than that of inorganic electron transport materials, sandwiching the organic electron transport material between the cathode and the inorganic electron transport material causes the organic electron transport material to significantly restrict the actual electron mobility of the inorganic electron transport material, thereby reducing the luminous efficiency of the corresponding light-emitting film layer group. This application proposes that the second electrode 5 directly cover the first inorganic electron transport layer 44a, the organic electron transport layer 44b, and the second inorganic electron transport layer 44c. The second electrode 5 is directly connected to the first inorganic electron transport layer 44a, the organic electron transport layer 44b, and the second inorganic electron transport layer 44c. This design can effectively improve the luminous efficiency of the first and third pixel sub-units using inorganic quantum dot materials.

[0057] Blue quantum dot materials have poor luminescence efficiency; therefore, organic light-emitting materials are used to prepare the light-emitting units in the blue sub-pixels, and correspondingly, organic electron transport materials are used to prepare the electron transport layer in the blue sub-pixels. In this embodiment, the light emitted by the first sub-quantum dot light-emitting unit 43a is red and / or green light. The light emitted by the organic light-emitting unit 43b is blue light. The light emitted by the second sub-quantum dot light-emitting unit 43c is red and / or green light.

[0058] In addition, in this embodiment, since the second electrode 5 is fabricated by laying it across the entire display area, the display panel also includes an auxiliary electrode 6 to reduce voltage drop (IR drop) on the second electrode 5.

[0059] Multiple second openings 22 are formed on the pixel defining layer 2. Each second opening 22 is located between two adjacent first openings 21. The second opening 22 is adjacent to the first opening 21. An auxiliary electrode 6 is disposed within a second opening 22. A second electrode 5 covers the auxiliary electrode 6. The second electrode 5 is directly connected to the auxiliary electrode 6. The auxiliary electrode 6 is made of a material with good conductivity; by being directly connected to the second electrode 5, it can effectively reduce the resistivity of the second electrode 5 and alleviate voltage loss on the second electrode 5.

[0060] The auxiliary electrode 6 can have the same film structure as the first electrode 3. Specifically, the auxiliary electrode 6 can be a single-layer conductive structure, a double-layer conductive structure, or a triple-layer conductive structure. The auxiliary electrode 6 can be disposed in the same layer as the first electrode 3 or in a different layer. When the auxiliary electrode 6 is disposed in the same layer as the first electrode 3, the auxiliary electrode 6 and the first electrode 3 can be fabricated in the same process, thereby improving process efficiency and saving costs.

[0061] It is understood that in another specific embodiment of this application, the first electrode 3 is disposed on the side of the first opening 21 near the substrate 1. Specifically, the first electrode 3 is disposed on the substrate 1, and the pixel defining layer 2 is disposed on the first electrode 3.

[0062] It is understood that in another specific embodiment of this application, the first electrode 3 is a cathode and the second electrode 5 is an anode. Specifically, the first electrode 3 is sequentially provided with an electron transport layer, a light-emitting unit, a hole transport layer, a hole injection layer, and the second electrode 5.

[0063] It is understood that, in another specific embodiment of this application, the auxiliary electrode 6 is disposed on the side of the second opening 22 near the substrate 1. Specifically, the auxiliary electrode 6 is disposed on the substrate 1, and the pixel defining layer 2 is disposed on the auxiliary electrode 6.

[0064] It is understood that the auxiliary electrode 6 can also be disposed at intervals in different conductive film layers. It should be noted that the structure of the auxiliary electrode 6 in this embodiment is only schematic and is used to facilitate the description of this embodiment. The specific structure of the auxiliary electrode 6 can be referred to the prior art, and will not be described in detail here.

[0065] This application provides a method for manufacturing a display panel, such as... Figures 2A to 2I As shown. The display panel includes multiple light-emitting units arranged in an array, and includes the following steps:

[0066] Step B1, as follows Figure 2AAs shown, a substrate 1 is provided. A pixel defining layer 2 is formed on the substrate 1. A plurality of first openings 21 and a plurality of second openings 22 are formed on the pixel defining layer 2. A first electrode 3 is disposed within a first opening 21. The first opening 21 exposes the first electrode 3. An auxiliary electrode 6 is disposed within a second opening 22. The second opening 22 exposes the auxiliary electrode 6.

[0067] Specifically, step B1 includes the following steps:

[0068] Step B11: A patterned first electrode 3 and an auxiliary electrode 6 are formed on the substrate 1.

[0069] Step B12: A pixel defining layer 2 is formed on the first electrode 3 and the auxiliary electrode 6, such that the first electrode 3 is disposed in the first opening 21 and the auxiliary electrode 6 is disposed in the second opening 22.

[0070] Step B13: Pattern the pixel defining layer 2 to form a plurality of first openings 21 and a plurality of second openings 22 on the pixel defining layer 2.

[0071] It is understood that, in another specific embodiment of this application, the first electrode 3 may also be disposed on the side of the first opening 21 near the substrate 1. Specifically, the first electrode 3 is disposed on the substrate 1, and the pixel defining layer 2 is disposed on the first electrode 3.

[0072] Step B2, as follows Figure 2B As shown, a hole injection layer 41, a hole transport layer 42, and a light-emitting unit are sequentially formed on the first electrode 3 located within the first opening 21.

[0073] Specifically, the hole injection layer 41, the hole transport layer 42, and the light-emitting unit are disposed on the first electrode 3 within the first opening 21 by inkjet printing.

[0074] Step B2 includes:

[0075] B21. A first quantum dot light-emitting unit 43a is inkjet printed inside the first opening 21. An organic light-emitting unit 43b is inkjet printed inside another first opening 21. A second quantum dot light-emitting unit 43c is inkjet printed inside yet another first opening 21.

[0076] The first quantum dot light-emitting unit 43a and the second quantum dot light-emitting unit 43c are made of inorganic quantum dot materials. The organic light-emitting unit 43b is made of organic light-emitting materials.

[0077] Step B3: Deposit a first inorganic electron transport layer 44a on the first quantum dot light-emitting unit 43a. Deposit a second inorganic electron transport layer 44c on the second quantum dot light-emitting unit 43c.

[0078] The first inorganic electron transport layer 44a and the second inorganic electron transport layer 44c are made of inorganic electron transport materials, such as zinc oxide, zinc magnesium oxide, etc.

[0079] Step B4: Form a magnetic material layer 7 on the inorganic electron transport layer.

[0080] Step B4 includes:

[0081] B41, such as Figure 2C As shown, magnetic ink 71 is deposited in the first opening 21 and the second opening 22, where inorganic electron transport layers are disposed, using an inkjet printing process. The magnetic ink 71 is located on the first inorganic electron transport layer 44a, the second inorganic electron transport layer 44c, and the auxiliary electrode 6. The magnetic ink 71 comprises a material that can be attracted by magnetic elements.

[0082] Specifically, magnetic ink 71 contains materials such as iron, nickel, and cobalt.

[0083] B42, such as Figure 2D As shown, a display panel printed with magnetic ink is subjected to vacuum drying treatment, and the display panel after vacuum drying treatment is annealed and baked to form a magnetic material layer 7 in the first opening 21 and the second opening 22 where the inorganic electron transport layer is provided.

[0084] It should be noted that the annealing and baking temperature of the display panel after the vacuum drying process is less than 250°C.

[0085] Step B5, as follows Figure 2E As shown, an organic electron transport layer 44b is formed on the magnetic material layer 7 by vapor deposition using an open mask. The organic electron transport layer 44b is made of an organic electron transport material. The organic electron transport layer 44b covers the magnetic material layer 7, the pixel defining layer 2, and the organic light-emitting unit 43b.

[0086] An aperture mask has a through-hole corresponding to the display area of ​​the display panel to block the non-display area. Compared to a fine mask, an aperture mask is much less expensive. The organic electron transport layer 44b formed by vapor deposition through the aperture mask covers the entire display area.

[0087] The energy level of the organic electron transport material used in the organic electron transport layer 44b matches the energy level of the organic light-emitting material used in the organic light-emitting unit 43b.

[0088] Step B6, as follows Figures 2F to 2H As shown, a magnetic element 8 is used to adsorb the magnetic material layer 7. The magnetic material layer 7 and the portion of the organic electron transport layer 44b connected to the magnetic material layer 7 are removed.

[0089] The magnetic element 8 includes a rotating portion 81 and a scraping portion 82. The rotating portion 81 has a rotatable magnetic surface 83. The magnetic surface 83 is opposite to the organic electron transport layer 44b by the rotation of the rotating portion 81. The scraping portion 82 is disposed on the rotation path of the rotating portion 81. The distance between the scraping portion 82 and the magnetic surface 83 is less than the thickness of the magnetic material layer 7.

[0090] Step B6 includes:

[0091] B61. Position the side of the substrate 1 closest to the magnetic material layer 7 toward the magnetic element 8. The magnetic material layer 7 is opposite to the magnetic surface 83 on the rotating part 81.

[0092] B62. The magnetic surface 83 adsorbs the magnetic material layer 7, so that the part of the organic electron transport layer 44b located in the second opening 22 where the organic light-emitting unit 43b is provided, together with the magnetic material layer 7, detaches from the second opening 22 to expose the auxiliary electrode 6.

[0093] The magnetic surface 83 adsorbs the magnetic material layer 7, causing the portion of the organic electron transport layer 44b located within the first opening 21 where the first quantum dot light-emitting unit 43a is located, and the magnetic material layer 7 to detach from the first opening 21 together, thus exposing the first inorganic electron transport layer 44a.

[0094] The magnetic surface 83 adsorbs the magnetic material layer 7, causing the portion of the organic electron transport layer 44b located within the second opening 22 where the organic light-emitting unit 43b is located, and the magnetic material layer 7 together detach from the second opening 22 to expose the auxiliary electrode 6.

[0095] The magnetic surface 83 adsorbs the magnetic material layer 7, causing the portion of the organic electron transport layer 44b located within the first opening 21 where the second sub-quantum dot light-emitting unit 43c is located, and the magnetic material layer 7 together detach from the first opening 21 to expose the third electron transport layer 44c.

[0096] The magnetic surface 83 adsorbs the magnetic material layer 7, causing the portion of the organic electron transport layer 44b located within the second opening 22 where the second quantum dot light-emitting unit 43c is located, and the magnetic material layer 7 to detach from the second opening 22 together, exposing the auxiliary electrode 6.

[0097] B63. Rotate the rotating part 81 to move the magnetic element 8 from one end of the substrate 1 to the other end of the substrate 1 until the magnetic material layer 7 and all the organic electron transport layers 44b located above the magnetic material layer 7 are removed, exposing the first inorganic electron transport layer 44a and the second inorganic electron transport layer 44c.

[0098] B64. During the rotation of the rotating part 81, the scraping part 82 removes the magnetic material layer 7 and the organic electron transport layer 44b adsorbed on the magnetic surface 83.

[0099] Step B7, as follows Figure 2I As shown, the second electrode 5 is deposited using an open mask template. The second electrode 5 is a transparent cathode covering the display area.

[0100] In this embodiment, the light emitted by the first sub-quantum dot light-emitting unit 43a is green. The light emitted by the organic light-emitting unit 43b is blue. The light emitted by the second sub-quantum dot light-emitting unit 43c is red.

[0101] The second electrode 5 is directly connected to and covers the first inorganic electron transport layer 44a, which is an inorganic electron transport material, and the first quantum dot light-emitting unit 43a is an inorganic quantum dot material. The second electrode 5 is also directly connected to and covers the organic electron transport layer 44b, which is an organic electron transport material, and the organic light-emitting unit 43b is an organic light-emitting material. Finally, the second electrode 5 is directly connected to and covers the second inorganic electron transport layer 44c, which is an inorganic electron transport material, and the second quantum dot light-emitting unit 43c is an inorganic quantum dot material.

[0102] It should be noted that after the second electrode 5 is formed, an encapsulation layer and a protective cover plate can also be formed on the second electrode 5. The encapsulation layer and the protective cover plate can be referred to the existing technology, and will not be described in detail here.

[0103] The material of the second electrode 5 is a high conductivity material, such as one or more of Ag, Al, or Mg / Ag.

[0104] In this embodiment, since the organic electron transport layer 44b is prepared using an open-face mask, removing the portion of the organic electron transport layer 44b above the magnetic material layer 7 ensures that the subsequently prepared second electrode 5 can be directly connected to the auxiliary electrode 6. The other layers in the light-emitting film layer group 4 are prepared by inkjet printing, and the second electrode 5 is prepared using an open-face mask, eliminating the need for a fine mask. Through the display panel preparation method in the above embodiments of this application, the preparation of each layer of the light-emitting film layer group and the second electrode 5 can be achieved using an open-face mask and inkjet printing, avoiding the use of excessively expensive fine masks and significantly reducing the production cost of the display panel.

[0105] In some embodiments, a patterning process can be used to remove the portion of the organic electron transport layer 44b located within the first opening 21 and the second opening 22, thereby achieving a direct connection between the second electrode and the auxiliary electrode 6 and the electron transport layer. However, the patterning process requires the use of a fine photomask, which significantly increases production costs.

[0106] Compared to existing display panel fabrication methods, the method provided in this application pre-forms a magnetic material layer on the auxiliary electrode and an electron transport layer made of inorganic material. After depositing an organic electron transport layer over the entire surface, a magnetic element is used to adsorb the magnetic material layer on the auxiliary electrode and the inorganic electron transport layer. Since the organic electron transport layer is located on the side of the magnetic material layer closest to the magnetic element, the portion of the organic electron transport layer corresponding to the magnetic material layer will detach from the first and second openings in the pixel defining layer along with the magnetic material layer.

[0107] After removing the magnetic material layer and organic electron transport layer from the corresponding inorganic electron transport layer in the red and green sub-pixel units using quantum dot luminescence, a second electrode is deposited by vapor deposition. This second electrode directly connects to and covers the inorganic electron transport layer. This avoids the reduction in the actual electron mobility of the inorganic electron transport layer caused by sandwiching the organic electron transport material between the cathode and the inorganic electron transport layer, thus ensuring high luminous efficiency for the red and green sub-pixel units using quantum dot luminescence.

[0108] After forming a second electrode on the auxiliary electrode after removing the magnetic material layer and the organic electron transport layer, the second electrode can be directly connected to the auxiliary electrode, which reduces the resistance of the second electrode, thereby improving the voltage loss phenomenon in the display panel, improving the brightness uniformity of the display panel, and thus improving the display effect of the display panel.

[0109] The display panel fabrication method provided in this application achieves the setting of an organic electron transport layer in the blue sub-pixel by using an open-type mask through the cooperation of a magnetic material layer and magnetic elements. The other film layers and the second electrode in the light-emitting film layer group are also fabricated by using an open-type mask and inkjet printing, which avoids the use of expensive fine masks and greatly reduces the production cost of the display panel.

[0110] The above provides a detailed description of a display panel and its preparation method according to the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A display panel, characterized in that, include: substrate; A pixel defining layer is disposed on the substrate and defines a plurality of first openings; A first electrode, wherein the first electrode is located in the first opening; Multiple light-emitting units are disposed in the first opening and located on the side of the first electrode away from the substrate. The light-emitting units include quantum dot light-emitting units and organic light-emitting units disposed in the same layer. An electron transport layer is disposed in the first opening and located on the side of the light-emitting unit away from the first electrode; The second electrode is disposed on the side of the electron transport layer away from the light-emitting unit; The electron transport layer includes an inorganic electron transport layer and an organic electron transport layer. The inorganic electron transport layer covers the quantum dot light-emitting unit, and the organic electron transport layer covers the organic light-emitting unit. The inorganic electron transport layer and the organic electron transport layer are disposed in the same layer.

2. The display panel according to claim 1, characterized in that, Also includes: The auxiliary electrode is provided with a plurality of second openings on the pixel defining layer. The auxiliary electrode is disposed in the second openings and the second electrode extends into the second openings and is electrically connected to the auxiliary electrode.

3. The display panel according to claim 1, characterized in that, The quantum dot light-emitting unit includes a first sub-quantum dot light-emitting unit and a second sub-quantum dot light-emitting unit arranged in the same layer. The first sub-quantum dot light-emitting unit, the second sub-quantum dot light-emitting unit, and the organic light-emitting unit are respectively arranged in a one-to-one correspondence with the first opening.

4. The display panel according to claim 3, characterized in that, The first quantum dot light-emitting unit emits red light, the second quantum dot light-emitting unit emits green light, and the organic light-emitting unit emits blue light.

5. The display panel according to claim 1, characterized in that, The first electrode is the anode, and the second electrode is the cathode; and / or The organic electron transport layer extends to the end face of the pixel defining layer.

6. A method for manufacturing a display panel, characterized in that, include: Provide substrate; A pixel defining layer is formed on the substrate, the pixel defining layer defining a plurality of first openings; A first electrode is formed within the first opening; A light-emitting unit is formed on the first electrode, the light-emitting unit including a quantum dot light-emitting unit and an organic light-emitting unit disposed in the same layer; An inorganic electron transport layer is formed on the quantum dot light-emitting unit; An organic electron transport layer is formed by vapor deposition on the inorganic electron transport layer and the organic light-emitting unit; Remove the organic electron transport layer from the inorganic electron transport layer to expose the surface of the inorganic electron transport layer; A second electrode is formed on the inorganic electron transport layer and the organic electron transport layer, which are disposed in the same layer.

7. The method for manufacturing a display panel according to claim 6, characterized in that, After the step of forming an inorganic electron transport layer on the quantum dot light-emitting unit and before the step of depositing an organic electron transport layer on the organic light-emitting unit, the method further includes: A magnetic material layer is formed on the inorganic electron transport layer.

8. The method for manufacturing a display panel according to claim 7, characterized in that, The step of removing the organic electron transport layer from the inorganic electron transport layer to expose the surface of the inorganic electron transport layer includes: A magnetic element is used to adsorb the magnetic material layer, thereby separating the organic electron transport layer on the magnetic material layer and the magnetic material layer together from the first opening.

9. The method for manufacturing a display panel according to claim 8, characterized in that, The step of forming a magnetic material layer on the inorganic electron transport layer includes: Magnetic ink is disposed within the first opening by inkjet printing, the magnetic ink comprising a material that can be attracted by the magnetic element; The substrate printed with magnetic ink is subjected to vacuum drying and annealing baking processes in sequence to form the magnetic material layer.

10. The method for manufacturing a display panel according to claim 8, characterized in that, The magnetic element includes a rotating part and a scraping part. The rotating part has a rotatable magnetic surface, which is positioned opposite the organic electron transport layer by the rotation of the rotating part. The scraping part is disposed on the rotation path of the rotating part; The step of using a magnetic element to adsorb the magnetic material layer includes: The magnetic surface adsorbs the magnetic material layer, causing the organic electron transport layer and the magnetic material layer located above the magnetic material layer to detach together from the first opening, thereby exposing the inorganic electron transport layer. Rotate the rotating part to move the magnetic element from one end of the substrate to the other end of the substrate; The scraping section removes the magnetic material layer and the organic electron transport layer adsorbed on the magnetic surface.

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