Display panel, method for manufacturing display panel, and display device

Abstract

The application discloses a display panel, a manufacturing method of the display panel and a display device. The display panel comprises a substrate, a light-emitting layer and a wavelength conversion layer which are stacked on the substrate. The light-emitting layer comprises a plurality of light-emitting subunits, each of which comprises a blue light-emitting body and a green light-emitting body. The wavelength conversion layer comprises a red subunit, a blue subunit and a green subunit. The red subunit comprises a quantum dot red conversion layer and a red color film layer which is stacked on the quantum dot red conversion layer. The blue subunit comprises a blue color film layer. The green subunit comprises a green color film layer. The orthographic projection of one red subunit on the substrate at least partially coincides with the orthographic projection of at least one light-emitting subunit on the substrate. The display panel provided by the application can improve the color conversion efficiency of an OLED display panel.

Description

Technical Field

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

[0002] QD-OLED (Quantum Dot Organic Light-Emitting Diode) technology boasts high-quality characteristics such as pure colors, a wider color gamut (90.3% BT2020), wide viewing angles, ultra-high contrast, and fast response times. Therefore, QD-OLED displays are attracting significant attention as the next generation of display devices. Currently, OLED devices are still dominated by BOLED (Blue-OLED) technology, which generally faces the problem of low color conversion efficiency, limiting the application of OLED in high-resolution display devices. Summary of the Invention

[0003] In view of the above problems, the present invention provides a display panel, a method for manufacturing the display panel, and a display device, which can improve the color conversion efficiency of the QD-OLED display panel to meet the manufacturing requirements of high-resolution display devices.

[0004] Firstly, this application provides the following technical solution through an embodiment:

[0005] A display panel, the display panel comprising: a substrate and a light-emitting layer and a wavelength conversion layer stacked on the substrate;

[0006] The light-emitting layer includes multiple light-emitting sub-units, and each light-emitting sub-unit includes a blue light emitter and a green light emitter;

[0007] The wavelength conversion layer includes a red subunit, a blue subunit, and a green subunit; the red subunit includes a quantum dot red conversion layer and a red color filter layer stacked on the quantum dot red conversion layer, the blue subunit includes a blue color filter layer, and the green subunit includes a green color filter layer;

[0008] Wherein, the orthographic projection of one of the red sub-units on the substrate at least partially overlaps with the orthographic projection of at least one of the light-emitting sub-units on the substrate.

[0009] In some embodiments, the display panel further includes a first pixel defining layer, the first pixel defining layer including a first blocking portion having a reflective effect and a plurality of first openings, wherein the red sub-unit, the blue sub-unit and the green sub-unit are located within the first openings.

[0010] In some embodiments, the first blocking portion includes a reflective layer and an isolation layer located on the surface of the reflective layer, wherein the material of the quantum dot red conversion layer is hydrophobic on the surface of the isolation layer.

[0011] In some embodiments, the isolation layer is made of fluororesin, and the quantum dot red conversion layer is a perovskite quantum dot red conversion layer.

[0012] In some embodiments, the luminance of the green light emitter is 90% to 96%, and the luminance of the blue light emitter is 4% to 10%.

[0013] In some embodiments, the display panel includes a plurality of pixel regions, wherein the ratio of the number of red sub-units, the number of blue sub-units and the number of green sub-units in each pixel region is 2:1:1.

[0014] In some embodiments, the display panel includes a plurality of pixel regions, in which the red sub-unit's orthogonal projection onto the substrate covers two adjacent light-emitting sub-units.

[0015] In some embodiments, the display panel further includes a second pixel defining layer having a plurality of second openings, wherein one of the light-emitting sub-units is located within one of the second openings;

[0016] The light-emitting subunit further includes an anode layer disposed on the side of the light-emitting subunit near the substrate.

[0017] In some embodiments, the display panel further includes a micro / nano structure layer disposed on the side of the anode layer near the substrate, wherein the orthographic projection of the micro / nano structure layer on the substrate at least partially overlaps with the orthographic projection of the red sub-unit on the substrate.

[0018] In some embodiments, the anode layer is a composite film of indium tin oxide, silver, and indium tin oxide, and the gaps in the micro / nano structure layer are filled with indium tin oxide.

[0019] In some embodiments, the display panel further includes a three-dimensional photonic crystal layer located between the anode layer and the light-emitting sub-unit;

[0020] The orthographic projection of the three-dimensional photonic crystal layer on the substrate at least partially overlaps with the orthographic projection of the red subunit on the substrate.

[0021] In some embodiments, the bandgap of the three-dimensional photonic crystal layer is 1.5 eV to 2.5 eV.

[0022] In some embodiments, the red subunit further includes a grating layer, the quantum dot red conversion layer and the red color film layer are stacked on the grating layer, the grating includes an edge region and a non-edge region, and the height of the edge region is greater than the height of the non-edge region.

[0023] In some embodiments, the grating includes a plurality of spaced columns;

[0024] The height of the pillars increases from the middle to the edge of the grating, with the lowest height of the pillars being 40nm to 120nm; the height difference between two adjacent pillars is 10nm to 60nm, and the spacing between them is 100nm to 400nm.

[0025] Secondly, based on the same inventive concept, this application provides the following technical solution through an embodiment:

[0026] A method for manufacturing a display panel, comprising:

[0027] Provide substrates;

[0028] A light-emitting layer and a wavelength conversion layer are stacked on the substrate.

[0029] The light-emitting layer includes multiple light-emitting sub-units, each of which includes a blue light emitter and a green light emitter; the wavelength conversion layer includes a red sub-unit, a blue sub-unit, and a green sub-unit; the red sub-unit includes a quantum dot red conversion layer and a red color filter layer stacked on the quantum dot red conversion layer, the blue sub-unit includes a blue color filter layer, and the green sub-unit includes a green color filter layer; the orthographic projection of one red sub-unit on the substrate at least partially coincides with the orthographic projection of at least one light-emitting sub-unit on the substrate.

[0030] Thirdly, based on the same inventive concept, this application provides the following technical solution through an embodiment:

[0031] A method for manufacturing a display panel, comprising:

[0032] Provides substrates and color filter substrates;

[0033] A light-emitting layer is formed on the substrate, and a wavelength conversion layer is formed on the color filter substrate;

[0034] The display panel is obtained by aligning a substrate including the light-emitting layer and a color filter substrate including the wavelength conversion layer.

[0035] The light-emitting layer includes multiple light-emitting sub-units, each of which includes a blue light emitter and a green light emitter; the wavelength conversion layer includes a red sub-unit, a blue sub-unit, and a green sub-unit; the red sub-unit includes a quantum dot red conversion layer and a red color filter layer stacked on the quantum dot red conversion layer, the blue sub-unit includes a blue color filter layer, and the green sub-unit includes a green color filter layer; the orthographic projection of one red sub-unit on the substrate at least partially coincides with the orthographic projection of at least one light-emitting sub-unit on the substrate.

[0036] Fourthly, based on the same inventive concept, this application provides the following technical solution through an embodiment:

[0037] A display device comprising any of the display panels provided in the first aspect embodiment.

[0038] Through one or more technical solutions of the present invention, the present invention has the following beneficial effects or advantages:

[0039] This invention provides a display panel that uses blue and green light-emitting emitters as backlights, i.e., B+G OLED emitters. Combined with a quantum dot red conversion layer and a red color film layer in the wavelength conversion layer, blue and green light can be converted into red light for emission. Then, the green light is filtered through the blue color film layer to achieve green light emission, and the green color film layer filters through the blue light to achieve green light emission, thereby obtaining the color pixels required for display. By using quantum dot materials to form a red conversion layer or red conversion film structure in the red sub-unit, i.e., the red sub-pixel area, the color conversion efficiency of QD-OLED can be improved, thereby meeting the requirements of high-resolution display devices.

[0040] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0041] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings.

[0042] In the attached diagram:

[0043] Figure 1 A schematic diagram of the structure of a B-OLED display panel is shown;

[0044] Figure 2A schematic diagram of a display panel employing an RRGB pixel arrangement according to an embodiment of the present disclosure is shown;

[0045] Figure 3 A schematic diagram of a display panel showing a red subunit covering two light-emitting subunits according to an embodiment of the present disclosure is shown;

[0046] Figure 4 A schematic diagram of a display panel with a micro / nano structure layer according to an embodiment of the present disclosure is shown;

[0047] Figure 5 A schematic diagram of a display panel having a three-dimensional photonic crystal layer according to an embodiment of the present disclosure is shown;

[0048] Figure 6 A schematic diagram of a display panel with a grating layer according to an embodiment of the present disclosure is shown;

[0049] Figure 7 A schematic diagram of the structure of a display panel manufactured using a cell-to-cell process according to an embodiment of the present disclosure is shown;

[0050] Figure 8 A schematic flowchart illustrating the manufacturing process of a display panel using an ON-EL process according to an embodiment of the present disclosure is shown;

[0051] Figure 9 A schematic flowchart illustrating the manufacturing process of a display panel using a cell-to-cell process according to an embodiment of the present disclosure is shown;

[0052] Figure 10 A schematic diagram of a display device according to an embodiment of the present disclosure is shown;

[0053] Explanation of reference numerals in the attached figures:

[0054] 100. Substrate; 110. Thin-film transistor layer;

[0055] 200. Light-emitting layer; 210. Light-emitting subunit; 211. Blue and green light-emitting elements; 212. Anode layer; 213. Cathode layer;

[0056] 300, Wavelength conversion layer; 310, Red sub-unit; 311, Quantum dot red conversion layer; 312, Red color filter layer; 320, Green sub-unit; 321, Green color filter layer; 330, Blue sub-unit; 331, Blue color filter layer; 340, First pixel limiting layer; 341, Reflective layer; 342, Isolation layer; 350, Raster layer; 360, Blocking layer;

[0057] 410. Second pixel confinement layer; 420. Micro / nano structure layer; 430. Three-dimensional photonic crystal layer;

[0058] 510, First thin-film encapsulation layer; 520, Second thin-film encapsulation layer; 530, Filler layer;

[0059] 600. Color film substrate. Detailed Implementation

[0060] Embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the disclosure. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.

[0061] The accompanying drawings illustrate various structural schematics according to embodiments of the present disclosure. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0062] In the context of this disclosure, when a layer / element is referred to as being "above" another layer / element, the layer / element may be directly above the other layer / element, or there may be an intermediate layer / element between them. Additionally, if a layer / element is "above" another layer / element in one orientation, then when the orientation is reversed, the layer / element may be "below" the other layer / element.

[0063] In the context of this disclosure, unless otherwise specified, the light-emitting side of the display panel is referred to as the "top side" or "upper side," and its opposite side as the "bottom side" or "lower side," to facilitate the description of relative directions. Accordingly, the direction from the bottom side to the top side is the thickness direction of the display panel, and the direction perpendicular to the thickness direction is the "planar direction" or "extension direction" of the display panel. It should be understood that these directions are relative directions rather than absolute directions.

[0064] Figure 1A B-OLED structure is shown, comprising, from bottom to top, the following layers along the thickness of the display panel: a substrate 100', a TFT (Thin Film Transistor) layer 110', an OLED light-emitting layer 200', a TFE (Thin Film Encapsulation) layer 500', a quantum dot color conversion layer (including an R-QD red light conversion layer 311' and a G-QD green light conversion layer 321'), and corresponding color filter layers (including a red color filter layer 312', a green color filter layer 322', and a blue color filter layer 331'). The OLED light-emitting layer 200' is a B-OLED electroluminescent device; the color conversion layer, especially the G-QD layer, contains nanoparticles with scattering effects to improve color conversion efficiency. During display, red light (R) and green light (G) are obtained by converting blue light (B) emitted from the OLED light-emitting layer 200' through the corresponding color conversion layer, and then passing through the corresponding color filter layer (CF) before being emitted; blue light (B) is directly obtained after passing through the blue color filter layer 331'.

[0065] To improve the color conversion efficiency of QD-OLED display panels, firstly, in some embodiments, please refer to... Figure 2 A display panel is provided, comprising:

[0066] The light-emitting layer 200 includes multiple light-emitting sub-units 210, each of which includes a blue light emitter and a green light emitter 211;

[0067] The wavelength conversion layer 300 includes a red subunit 310, a blue subunit 330, and a green subunit 320; the red subunit 310 includes a quantum dot red conversion layer 311 and a red color filter layer 312 stacked on the quantum dot red conversion layer 311, the blue subunit 330 includes a blue color filter layer 331, and the green subunit 320 includes a green color filter layer 321.

[0068] In this case, the orthographic projection of a red subunit 310 on the substrate 100 at least partially overlaps with the orthographic projection of at least one light-emitting subunit 210 on the substrate 100.

[0069] Optionally, the orthographic projection of a blue subunit 330 on the substrate 100 at least partially overlaps with the orthographic projection of a light-emitting subunit 210 on the substrate 100, and the orthographic projection of a green subunit 320 on the substrate 100 at least partially overlaps with the orthographic projection of a light-emitting subunit 210 on the substrate 100.

[0070] The display panel provided in this embodiment can be an OLED display panel, specifically a B+G OLED, which uses organic light-emitting diodes capable of simultaneously emitting blue and green light as the light-emitting sub-units 210. It is understood that the display panel can also use other types of electroluminescent devices capable of simultaneously emitting blue and green light as the light-emitting sub-units 210. The area where one light-emitting sub-unit 210 is located can be considered a sub-pixel area. A certain number (e.g., 3 or 4) of light-emitting sub-units 210 constitute the light-emitting area of ​​a color pixel. Unless otherwise specified, this disclosure uses an OLED display panel as an example for description.

[0071] In this embodiment, the light-emitting layer 200 and the wavelength conversion layer 300 are sequentially stacked on the substrate 100, that is, in the thickness direction of the display panel, from bottom to top, they are: substrate 100, light-emitting layer 200, and wavelength conversion layer 300. The blue and green light-emitting elements 211 in the light-emitting layer 200 can be made of commonly used organic light-emitting materials and can emit blue light and green light respectively. They are arranged in a certain order to form light-emitting sub-units 210 that can emit blue light and green light simultaneously. Optionally, the blue light emitted by the blue light-emitting element has a wavelength range of 460nm to 480nm, preferably 470nm, and the green light emitted by the green light-emitting element has a wavelength range of 520nm to 540nm, preferably 530nm, to meet the display requirements of this embodiment.

[0072] Currently, display panels commonly use the three primary colors of red, green, and blue to synthesize color pixels. Therefore, a wavelength conversion layer 300 is used to filter or convert blue and green light. Specifically, a quantum dot red conversion layer 311 and a red color film layer 312 are stacked at the red sub-unit 310. The quantum dot red conversion layer 311 is close to the light-emitting sub-unit 210 and converts the blue and green light emitted by the light-emitting layer 200 into red light through wavelength conversion. The red color film layer 312 is far from the light-emitting sub-unit 210 and plays a role in wavelength selective transmission, blocking non-red light from escaping. It should be noted that wavelength conversion refers to converting the wavelength of incident light to another wavelength without using additional energy, while wavelength selective transmission means allowing only a portion of the incident light with the required wavelength to pass through, while blocking light of other wavelengths from passing through.

[0073] Similarly, the blue color filter layer 331 in the blue sub-unit 330 is used to achieve blue light emission, and the green color filter layer 321 in the green sub-unit 320 is used to achieve green light emission, thereby realizing the emission of RGB primary colors. Therefore, a certain number of red sub-units 310, blue sub-units 330, and green sub-units 320 combined with the corresponding light-emitting sub-unit 210 can be regarded as a sub-pixel, and the three can be combined to form a colored RGB pixel.

[0074] Therefore, the orthographic projections of a red sub-unit 310, a blue sub-unit 330, and a green sub-unit 320 onto the substrate 100 should each coincide with the orthographic projection portion of at least one light-emitting sub-unit 210 onto the substrate 100 to obtain emitted light of the corresponding color. A preferred option is for the two to completely or substantially coincide to reduce light crosstalk between different sub-pixel regions.

[0075] Therefore, the display panel provided in this embodiment uses blue and green light emitters 211 as backlights, i.e., B+G OLED light emitters, combined with the quantum dot red conversion layer 311 and red color film layer 312 in the wavelength conversion layer 300, which can convert blue and green light into red light for emission. Then, the green light is filtered by the blue color film layer 331 to achieve green light emission, and the green color film layer 321 filters the blue light to achieve green light emission, thereby obtaining the color pixels required for display. By using quantum dot materials to form a red conversion layer or red conversion film structure in the red sub-unit 310, i.e., the red sub-pixel area, the color conversion efficiency of QD-OLED can be improved, thereby meeting the requirements of high-resolution display devices.

[0076] Currently, BOLED quantum dot color conversion layers are typically fabricated using printing to separately prepare red quantum dot conversion layers (R-QD) and green quantum dot conversion layers (G-QD). However, this method suffers from low light color conversion efficiency, resulting in poor color gamut (~90%) and impacting resolution. Therefore, while printing technology is currently the most feasible, it still has limitations in the development of high-resolution display products, while small-to-medium-sized display products have higher resolution requirements. Thus, further improving the color conversion efficiency, optimizing white balance, and enhancing brightness and color gamut are the key challenges to be addressed.

[0077] In some embodiments, the display panel further includes a first pixel defining layer 340, which includes a first blocking portion with a reflective function and a plurality of first openings, wherein a red sub-unit 310, a blue sub-unit 330 and a green sub-unit 320 are located within the first openings.

[0078] It should be understood that the “Pixel Defining Layer” (PDL) in this disclosure, such as the first pixel defining layer 340 mentioned here and the second pixel defining layer 410 mentioned below, is used to define the range of individual sub-pixels in the display panel, such as the range of red, green and blue sub-pixels, rather than the total range of a color RGB pixel.

[0079] The introduction of a first blocking portion with a reflective function in the first pixel limiting layer 340 can reflect or restore crosstalk light generated by the lower light-emitting sub-unit 210 to the atomic pixel area, thereby increasing the light output of the corresponding sub-pixel and improving the brightness of the display panel. The first blocking portion can be entirely made of reflective material, or a layer of reflective material can be deposited on the blocking portion substrate. The reflective material can be selected with a reflectivity of 90% or higher. The first opening is an opening area formed by being surrounded or divided by the first blocking portion. Multiple first openings can be formed by first manufacturing a complete first blocking portion and then etching or punching holes.

[0080] In some embodiments, the first blocking portion includes a reflective layer 341 and an isolation layer 342 located on the surface of the reflective layer 341. The material of the quantum dot red conversion layer 311 is hydrophobic on the surface of the isolation layer 342. The reflective layer 341 is used to reflect crosstalk light to the atomic pixel region, while the isolation layer 342 utilizes the surface affinity between different materials to ensure that the quantum dot red conversion layer 311 is formed only within the first opening where the red sub-unit 310 is located, thereby improving the accuracy of pixel definition.

[0081] Optionally, the quantum dot red conversion layer 311 can be a perovskite quantum dot red conversion layer 311, and the perovskite composition system can be APbBr. x Cl 3-x A can be MA(CH3NH3), FA(HC(NH2)2), Cs, or a combination of one or more of them, such as MA x FA 1-x It can simultaneously convert blue and green light into red light. Correspondingly, the material of the isolation layer 342 can be fluoropolymer (CYTOP, perfluoro(1-butenyl vinyl ether) polymer) or other hydrophobic materials that do not spread or deposit perovskite quantum dot materials on the surface.

[0082] Taking CYTOP resin as an example, leveraging the characteristic that perovskite quantum dots do not spread or deposit on the surface of CYTOP resin, the corresponding sub-pixel regions can be prepared using plasma etching. This ensures that perovskite quantum dots only deposit in areas without CYTOP resin to form the corresponding red conversion layer, thereby further improving the precision of pixel definition and enhancing the color conversion efficiency of the device. Simultaneously, by combining the reflective layer 341 with the CYTOP resin isolation layer, a better white balance effect can be achieved with only one type of perovskite red light color conversion film.

[0083] Optional, please refer to Figure 2The reflective layer 341 has an isosceles trapezoidal cross-sectional shape in the thickness direction of the display panel. Studies have shown that, compared to triangles, squares, etc., the isosceles trapezoidal shape enables the reflective layer 341 to more effectively restore crosstalk light from other pixel sub-regions to the original pixel sub-region, thereby further improving the light output of the corresponding sub-pixel.

[0084] Optional, please refer to Figure 2 The wavelength conversion layer 300 also includes a barrier layer 360 (or protective layer), which covers the red color filter layer 312, the green color filter layer 321, the blue color filter layer 331, and the first pixel defining layer 340. The barrier layer 360 may be made of silicon nitride. i N x or silicon dioxide S i O x The coating film can be made of materials such as silicon nitride and silicon oxide, and can be a single-layer film or a multilayer composite film.

[0085] In some embodiments, please refer to Figure 2 The display panel also includes a second pixel defining layer 410 having a plurality of second openings, and a light-emitting subunit 210 located within one of the second openings.

[0086] The light-emitting subunit 210 also includes an anode layer 212 disposed on the side of the light-emitting subunit 210 near the substrate 100. Optionally, the light-emitting subunit 210 also includes a cathode layer 213, with blue light emitters and green light emitters 211 located between the anode layer 212 and the cathode layer 213.

[0087] Specifically, in an OLED display panel, the anode layer 212, blue and green light emitters 211, and cathode layer 213 of a light-emitting sub-unit 210 constitute the light-emitting region of a sub-pixel. Therefore, the second pixel defining layer 410 defines multiple light-emitting sub-units 210 in the light-emitting layer 200, and these multiple light-emitting sub-units 210 are arranged in an array. Each light-emitting sub-unit 210 in the array can be considered an OLED. During display, charge carriers supplied from the cathode and anode recombine in the blue light emitter to generate blue light, and recombine in the green light emitter to generate green light. Therefore, in the light-emitting layer 200, multiple light-emitting sub-units 210 arranged parallel to the display surface array of the display panel form the OLED light-emitting dot matrix of the display panel.

[0088] Optionally, the display panel may also include a thin-film field-effect transistor layer 110 formed between the substrate 100 and the anode layer 212 for driving each sub-pixel on the display panel.

[0089] Studies have shown that the required brightness ratio for achieving white balance with red light (R), green light (G), and blue light (B) can be 3:6:1. Therefore, in some embodiments, the blue emitter (B) and green emitter (G) can be arranged in one of the following ways: BG, BBG, BBBG, and BBGB, to optimize the white balance of the display device. Furthermore, the luminance of the green emitter is 90%–96%, and the luminance of the blue emitter is 4%–10%, with a preferred choice of G:B = 94.5%:4.9% to more accurately achieve the required brightness ratio for white balance.

[0090] In some embodiments, the ratio of red sub-units 310, blue sub-units 330, and green sub-units 320 in each pixel region is 2:1:1. Here, a pixel region refers to a single colored pixel unit in the display panel; therefore, the display panel includes multiple pixel regions. A preferred arrangement is... Figure 2 The RRGB shown can also be represented using RGBR. The reason for setting the number of R sub-pixels, G sub-pixels, and B sub-pixels in a color pixel unit to 2:1:1 is that the green sub-pixel (G) in this disclosure is obtained by directly projecting blue light + green light after filtering through the green color filter layer 321. Compared with the conventional method of obtaining green light by converting the wavelength through the G-QD green light color conversion layer and filtering through the green color filter layer 321, the emission ratio of directly projected green light will be significantly increased, resulting in a relative lack of red light and affecting the white balance effect of the display device. Therefore, this embodiment increases the emission amount of red light by adjusting the number of red sub-units 310 (R), thereby further improving the white balance capability of the display device.

[0091] The foregoing embodiments achieve white balance by adjusting the number of red sub-units 310 or the arrangement of sub-pixels. For some alternative embodiments, please refer to... Figure 3 Alternatively, a scheme can be adopted in which the orthographic projection of the red subunit 310 onto the substrate 100 covers two adjacent light-emitting subunits 210 in each pixel region. By extending the red subunit 310 to cover two light-emitting subunits 210 (backlight), the commonly used "RGB" pixel arrangement can be used. While achieving the same enhanced device white balance as the "RRGB" pixel arrangement, a certain aperture ratio can also be increased.

[0092] The above embodiments optimize the white balance of the display panel and improve its brightness and color gamut by adjusting the arrangement or number of red conversion layers or red sub-pixels. Further research shows that the white balance of the display panel can also be optimized and its brightness and color gamut improved by adjusting the light extraction structure of the light-emitting sub-unit 210, i.e., improving the light extraction efficiency of the backlight corresponding to the red sub-pixels, as detailed below:

[0093] In some alternative embodiments, please refer to Figure 4 The display panel also includes a micro-nano structure layer 420, which is disposed on the side of the anode layer 212 close to the substrate 100. The orthographic projection of the micro-nano structure layer 420 on the substrate 100 at least partially overlaps with the orthographic projection of the red sub-unit 310 on the substrate 100.

[0094] A micro / nano structure layer 420 is disposed on the substrate 100 corresponding to the red sub-pixel. Micro / nano structures are nanoscale structures, designed, manufactured, and perfected at the atomic scale using appropriate atomic-level components combined with precisely controlled mechanical techniques. Oxides or metal oxides can be deposited using methods such as chemical vapor deposition (CVD) or atomic layer deposition (ALD), and the desired micro / nano structure layer 420 is formed after etching. The introduction of the micro / nano structure layer 420 can improve the surface plasmon polariton (SPP) effect at the metal interface in the anode, solving the SPP problem caused by the metal interface in top-emitting OLEDs. This effectively improves photon extraction efficiency, enhances the color conversion efficiency of the perovskite quantum dot red conversion layer 311, optimizes the white balance of the display panel, and improves the brightness and color gamut of the display panel.

[0095] It should be noted that after introducing the micro-nano structure layer 420 to improve photon extraction efficiency, the corresponding red light color conversion efficiency is also improved. At this time, the RRGB sub-pixel arrangement method is no longer needed, and the commonly used RGB arrangement method can be used to achieve the white balance of the display panel.

[0096] One example of the morphology of the micro / nano structure layer 420 is a micro / nano structured grating, referred to as a micro / nano grating. After forming the micro / nano grating, an anode can be fabricated on top of the grating, such as a reflective anode composed of a composite film of indium tin oxide, silver, and indium tin oxide (ITO / Ag / ITO), and indium tin oxide can be filled into the gaps between the micro / nano grating. Subsequently, blue and green light emitters 211 are fabricated on the reflective anode. The introduction of the micro / nano grating can effectively improve the surface plasmon polariton (SPP) effect at the metal-Ag interface in the reflective anode.

[0097] Optionally, the depth of the micro-nano grating in the thickness direction of the display panel is 10nm to 60nm, and the scale in the extension direction or planar direction of the display panel is 200nm to 600nm, with a gap of 10nm to 600nm. Research and practice have shown that gratings with this microstructure have better photon extraction efficiency.

[0098] In some alternative embodiments, please refer to Figure 5The display panel also includes a three-dimensional photonic crystal layer 430, which is located between the anode layer 212 and the light-emitting sub-unit 210; the orthographic projection of the three-dimensional photonic crystal layer 430 on the substrate 100 at least partially overlaps with the orthographic projection of the red sub-unit 310 on the substrate 100.

[0099] A photonic crystal is an artificial crystal structure formed by arranging two materials with different dielectric constants in space at a certain period. Three-dimensional photonic crystals can generate a complete bandgap in all directions. In this embodiment, the introduction of a three-dimensional photonic crystal can effectively improve photon extraction efficiency, thereby optimizing the white balance of the display panel and enhancing its brightness and color gamut.

[0100] An optional three-dimensional photonic crystal structure consists of alternating layers of silicon oxide and silicon nitride dielectric. Optionally, the thickness of the silicon nitride dielectric layer can be 40 nm to 100 nm. The bandgap of the three-dimensional photonic crystal is designed to correspond to the color band range of the sub-pixel. For the red sub-pixel, by adjusting the thickness ratio of silicon oxide and silicon nitride, the bandgap of the three-dimensional photonic crystal is controlled between 1.5 eV and 2.5 eV, with 2 eV being a preferred choice.

[0101] The aforementioned embodiment improves the device's white balance by optimizing the light extraction efficiency of the backlight in the red sub-pixel region, with the aim of increasing the amount of red light emitted. Further research shows that the proportion of red light emitted can be further increased by optimizing the structure of the red color film layer 312.

[0102] In some alternative embodiments, please refer to Figure 6 The red subunit 310 also includes a grating layer 350, a quantum dot red conversion layer 311, and a red color film layer 312 stacked on the grating layer 350. The grating includes an edge region and a non-edge region, with the height of the edge region being greater than that of the non-edge region. By introducing a grating layer 350 with high sides and low center at the bottom of the perovskite quantum dot red conversion layer 311, the collimation path of light output can be improved, and light crosstalk can be reduced. Combined with the introduction of the reflective layer 341, the proportion of red light emitted can be further increased.

[0103] Optionally, the grating includes multiple spaced pillars; the height of the pillars increases from the center to the edge of the grating, with a minimum pillar height of 40nm to 120nm; the height difference between two adjacent pillars is 10nm to 60nm, and the spacing between them is 100nm to 400nm. That is, the height of the grating layer 350 in the central or intermediate region is 40nm to 120nm, and from the center to both ends, the height of the grating layer 350 gradually increases, with a height increase step of 10nm to 60nm, and the spacing is the width between two pillars. The scale of the grating layer 350 in the planar or extending direction of the display panel is 200nm to 600nm.

[0104] The shape of the grating layer 350 can be a polygon with high edges and low center; a preferred choice is as follows: Figure 6 The arc shape shown, with its high edges and low center, has a better ability to reduce light crosstalk.

[0105] The grating layer 350 can be made of metal oxides, such as any one or more of aluminum oxide and titanium dioxide, or of organic polymer semiconductor materials, such as any one or more of polymethyl methacrylate, polymethacrylonitrile, polyvinyl alcohol, polyvinylidene fluoride and polyacrylic acid.

[0106] It should be noted that the foregoing embodiments and appendices Figures 2-6 The display panel structure shown is manufactured using the ON-EL method. ON-EL refers to the process of continuously fabricating a wavelength conversion layer 300 on the light-emitting layer 200. Therefore, the display panel manufactured using the ON-EL method also includes a first thin film encapsulation layer 510 (TFE Encapsulation) located between the light-emitting layer 200 and the wavelength conversion layer 300. The wavelength conversion layer 300 is formed or stacked on the first thin film encapsulation layer 510.

[0107] In addition, the display panel provided in this disclosure can also be manufactured using a cell-to-cell process, such as... Figure 7 As shown. The cell assembly process refers to forming a light-emitting layer 200 on a substrate 100 and a wavelength conversion layer 300 on a color filter substrate 600, and then assembling the two together to obtain a display panel. Therefore, in Figure 7 The display panel also includes a second thin film encapsulation layer 520, a filler layer 530, and a color filter substrate 600. A wavelength conversion layer 300 is disposed on the color filter substrate 600. The second thin film encapsulation layer 520 and the wavelength conversion layer 300 are connected to each other through the filler layer 530.

[0108] Based on the foregoing embodiments, the display panel provided in this disclosure has the following characteristics:

[0109] 1) The display panel uses B+G OLED as the backlight. Blue light (B) and green light (G) are obtained by transmission through the corresponding color filter layer (CF), while red light is obtained by perovskite quantum dot red conversion layer 311 Per-QD combined with red color filter layer 312. Taking advantage of the difference in affinity between perovskite quantum dots on different material surfaces, it does not deposit on the surface of the isolation layer 342 of the first pixel limiting layer 340. This forms a color conversion film with better color conversion efficiency in the red sub-pixel area, meeting the requirements of high-resolution display products. It should be noted that the display panel provided in this disclosure only needs to use perovskite quantum dot red conversion layer 311 for red light conversion. Thanks to the better color conversion efficiency, compared with conventional solutions, it is no longer necessary to add nanoparticles with scattering effect to the red conversion layer.

[0110] 2) By optimizing the arrangement of red sub-pixels, or optimizing the light extraction structure (improving the light extraction efficiency of the backlight corresponding to the red pixels), or optimizing the emission of red light in the wavelength conversion layer 300, the white balance, brightness and color gamut of the display device can be further improved to better meet the needs of small and medium-sized high-resolution display products.

[0111] As mentioned in the above embodiments, the display panel can be manufactured using an ON-EL or a cascaded configuration. Regarding the ON-EL configuration, based on the same inventive concept, secondly, in some embodiments, please refer to... Figure 8 A method for manufacturing a display panel is provided, comprising:

[0112] S81: Provides substrate 100;

[0113] S82: A light-emitting layer 200 and a wavelength conversion layer 300 are formed on a substrate 100;

[0114] The light-emitting layer 200 includes a plurality of light-emitting sub-units 210, each of which includes a blue light emitter and a green light emitter; the wavelength conversion layer 300 includes a red sub-unit 310, a blue sub-unit 330, and a green sub-unit 320; the red sub-unit 310 includes a quantum dot red conversion layer 311 and a red color filter layer 312 stacked on the quantum dot red conversion layer 311, the blue sub-unit 330 includes a blue color filter layer 331, and the green sub-unit 320 includes a green color filter layer 321; the orthographic projection of a red sub-unit 310 on the substrate 100 at least partially coincides with the orthographic projection of at least one light-emitting sub-unit 210 on the substrate 100.

[0115] Taking OLED display panels as an example, for display panels with optimized sub-pixel arrangement, an optional fabrication process based on the ON-EL method includes:

[0116] 1) A thin-film field-effect transistor layer 110, an anode layer 212, a second pixel limiting layer 410, a blue light emitter and a green light emitter 211, a cathode layer 213 and a first thin-film encapsulation layer 510 (TFE) are formed on a substrate 100.

[0117] 2) A reflective layer 341 is formed on the first thin film encapsulation layer 510, and then CYTOP resin is deposited on the reflective layer 341 to obtain the first pixel defining layer 340. The corresponding sub-pixel region is prepared by plasma etching to obtain the perovskite quantum dot red conversion layer 311. Since the perovskite quantum dots do not spread on the surface of the CYTOP resin, they can be deposited by spin coating or blade coating.

[0118] 3) A red color filter layer 312 is formed in the red sub-unit 310 region, a blue color filter layer 331 is formed in the blue sub-unit 330 region, and a green color filter layer 321 is formed in the green sub-unit 320 region. Then, a barrier layer material is deposited to form a barrier layer 360, thus obtaining the display panel. The red sub-unit 310, green sub-unit 320, and blue sub-unit 330 regions can use either an RRGB pixel arrangement or an RGB pixel arrangement. In the latter case, the perovskite quantum dot red conversion layer 311's orthogonal projection onto the emitting layer 200 needs to cover two adjacent blue and green emitting elements.

[0119] For display panels with micro / nano structures at the bottom of the anode to optimize the light extraction structure, an optional fabrication process based on the ON-EL method includes:

[0120] 1) A thin-film field-effect transistor layer 110 is formed on a substrate 100;

[0121] 2) Deposit oxides or metal oxides using CVD or ALD methods to form micro-nano gratings with micro-nano structures, and then prepare an anode layer 212, such as an ITO / Ag / ITO reflective anode, on top of the micro-nano grating;

[0122] 3) A second pixel limiting layer 410, a blue light emitter and a green light emitter 211, a cathode layer 213 and a first thin film encapsulation layer 510 are formed on the anode layer 212;

[0123] 4) A first pixel defining layer 340 is formed on the first thin film encapsulation layer 510, and a corresponding sub-pixel region is prepared by plasma etching. A perovskite quantum dot red conversion layer 311 and a red color film layer 312 are formed in the red sub-unit 310, a blue color film layer 331 is formed in the blue sub-unit 330 region, and a green color film layer 321 is formed in the green sub-unit 320 region. Then, a barrier layer material is deposited to form a barrier, and a display panel is obtained.

[0124] For display panels employing composite anodes with three-dimensional photonic crystals to optimize the light extraction structure, an optional fabrication process based on the ON-EL method includes:

[0125] 1) A thin-film field-effect transistor layer 110, an anode layer 212, and a second pixel defining layer 410 are formed on a substrate 100;

[0126] 2) A three-dimensional photonic crystal layer 430 is fabricated on the anode layer 212 in the red sub-pixel region. This can be achieved by alternating deposition and etching of silicon oxide and silicon nitride media. Specifically, this includes: depositing a layer of SiO2 and etching it to create a pattern, then depositing a layer of SiN and etching it to create a pattern; repeating the above steps to obtain a three-dimensional photonic crystal structure with alternating layers of silicon oxide and silicon nitride media; wherein, for the red sub-pixel, by controlling the thickness ratio of silicon oxide and silicon nitride, the bandgap of the three-dimensional photonic crystal is made to be approximately 2 eV, so as to well match the wavelength range of the red light emitted by the red sub-pixel;

[0127] 3) A blue and green light emitter, a cathode layer 213, and a first thin film encapsulation layer 510 are formed on the three-dimensional photonic crystal in the red sub-pixel region or the anode layer 212 in the other sub-pixel region;

[0128] 4) A first pixel defining layer 340 is formed on the first thin film encapsulation layer 510, a perovskite quantum dot red conversion layer 311 and a red color film layer 312 are formed in the red sub-unit 310, a blue color film layer 331 is formed in the blue sub-unit 330 region, and a green color film layer 321 is formed in the green sub-unit 320 region. Then, a barrier layer material is deposited to form a barrier, thereby obtaining a display panel.

[0129] Regarding the manufacturing process of the box, based on the same inventive concept, in some embodiments, please refer to... Figure 9 A method for manufacturing a display panel is provided, comprising:

[0130] S901: Provides a substrate 100 and a color filter substrate 600;

[0131] S902: A light-emitting layer 200 is formed on a substrate 100, and a wavelength conversion layer 300 is formed on a color filter substrate 600;

[0132] S903: A display panel is obtained by aligning a substrate 100 including a light-emitting layer 200 and a color filter substrate 600 including a wavelength conversion layer 300.

[0133] Taking OLED as an example, for display panels with optimized subpixel arrangement, an optional cell manufacturing process includes:

[0134] 1) A light-emitting layer 200 is fabricated on a substrate 100, including a thin-film field-effect transistor layer 110, an anode layer 212, a blue light emitter and a green light emitter 211, a second pixel defining layer 410, a cathode layer 213 and a first thin-film encapsulation layer 510 (TFE) stacked sequentially.

[0135] 2) A wavelength conversion layer 300 is fabricated on a transparent color filter substrate 600. First, a reflective layer 341 is formed on the color filter substrate 600. Then, a CYTOP resin layer is deposited on the reflective layer 341 to obtain a first pixel defining layer 340. Then, a red color filter layer 312 and a perovskite quantum dot red conversion layer 311 are formed in the red sub-unit 310 defined by the first pixel defining layer 340. A green color filter layer 321 is formed in the green sub-unit 320. A blue color filter layer 331 is formed in the blue sub-unit 330. Then, a barrier layer material is deposited to form a barrier layer 360.

[0136] 3) The color filter substrate 600 including the wavelength conversion layer 300 and the substrate substrate 100 including the light emission layer 200 are assembled into a cell, and a filling layer 530 is formed between the barrier layer 360 and the first thin film encapsulation layer 510 to obtain a display panel.

[0137] The manufacturing process for other types of display panels is similar to that in the above embodiments, and will not be described in detail here.

[0138] Based on the same inventive concept, in the fourth aspect, please refer to Figure 10 A display device is provided, including any of the display panels provided in the first aspect embodiment. The display device may be a computer or conference monitor, tablet computer, mobile phone, or other similar product, and the display panel may be an OLED display panel or a QD-OLED display panel.

[0139] The methods and display devices of the second to fourth aspects are based on the display panel provided in the first aspect embodiment, and therefore the corresponding beneficial effects and principles are the same as those of the first aspect embodiment, and will not be repeated here.

[0140] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0141] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A display panel, characterized in that, The display panel includes: a substrate and a light-emitting layer and a wavelength conversion layer stacked on the substrate; The light-emitting layer includes multiple light-emitting sub-units, and each light-emitting sub-unit includes a blue light emitter and a green light emitter; The wavelength conversion layer includes a red subunit, a blue subunit, and a green subunit; the red subunit includes a quantum dot red conversion layer and a red color filter layer stacked on the quantum dot red conversion layer, the blue subunit includes a blue color filter layer, and the green subunit includes a green color filter layer; Wherein, the orthographic projection of one of the red sub-units on the substrate at least partially overlaps with the orthographic projection of at least one of the light-emitting sub-units on the substrate; The display panel includes multiple pixel areas, and in each pixel area, the ratio of the number of red sub-units, the number of blue sub-units, and the number of green sub-units is 2:1:1; or The display panel includes multiple pixel areas, and in each pixel area, the red sub-unit's orthogonal projection onto the substrate covers two adjacent light-emitting sub-units.

2. The display panel as described in claim 1, characterized in that, It also includes a first pixel defining layer, which includes a first blocking portion with a reflective function and a plurality of first openings, wherein the red sub-unit, the blue sub-unit and the green sub-unit are located within the first openings.

3. The display panel as described in claim 2, characterized in that, The first blocking part includes a reflective layer and an isolation layer located on the surface of the reflective layer, wherein the material of the quantum dot red conversion layer is hydrophobic on the surface of the isolation layer.

4. The display panel as described in claim 3, characterized in that, The isolation layer is made of fluororesin, and the quantum dot red conversion layer is a perovskite quantum dot red conversion layer.

5. The display panel as described in claim 1, characterized in that, The luminous intensity of the green light-emitting body is 90%~96%, and the luminous intensity of the blue light-emitting body is 4%~10%.

6. The display panel as described in claim 1, characterized in that, The display panel further includes a second pixel defining layer having a plurality of second openings, and one of the light-emitting sub-units is located within one of the second openings; The light-emitting subunit further includes an anode layer disposed on the side of the light-emitting subunit near the substrate.

7. The display panel as described in claim 6, characterized in that, It also includes a micro / nano structure layer disposed on the side of the anode layer near the substrate, wherein the orthographic projection of the micro / nano structure layer on the substrate at least partially overlaps with the orthographic projection of the red subunit on the substrate.

8. The display panel as described in claim 7, characterized in that, The anode layer is a composite film of indium tin oxide, silver and indium tin oxide, and the gaps in the micro-nano structure layer are filled with indium tin oxide.

9. The display panel as described in claim 6, characterized in that, It also includes a three-dimensional photonic crystal layer, which is located between the anode layer and the light-emitting subunit; The orthographic projection of the three-dimensional photonic crystal layer on the substrate at least partially overlaps with the orthographic projection of the red subunit on the substrate.

10. The display panel as claimed in claim 9, characterized in that, The bandgap of the three-dimensional photonic crystal layer is 1.5 eV to 2.5 eV.

11. The display panel as claimed in claim 1, characterized in that, The red subunit further includes a grating layer, the quantum dot red conversion layer and the red color film layer are stacked on the grating layer, the grating includes an edge region and a non-edge region, and the height of the edge region is greater than the height of the non-edge region.

12. The display panel as claimed in claim 11, characterized in that, The grating includes multiple columns arranged at intervals; The height of the pillars increases from the middle to the edge of the grating, with the lowest height of the pillars being 40nm~120nm; the height difference between two adjacent pillars is 10nm~60nm, and the spacing between them is 100nm~400nm.

13. A method for manufacturing a display panel, characterized in that, include: Provide substrates; A light-emitting layer and a wavelength conversion layer are stacked on the substrate. The light-emitting layer includes multiple light-emitting sub-units, each of which includes a blue light emitter and a green light emitter; the wavelength conversion layer includes a red sub-unit, a blue sub-unit, and a green sub-unit; the red sub-unit includes a quantum dot red conversion layer and a red color film layer stacked on the quantum dot red conversion layer; the blue sub-unit includes a blue color film layer; and the green sub-unit includes a green color film layer. The orthographic projection of one of the red sub-units on the substrate at least partially overlaps with the orthographic projection of at least one of the light-emitting sub-units on the substrate; The display panel includes multiple pixel areas, and in each pixel area, the ratio of the number of red sub-units, the number of blue sub-units, and the number of green sub-units is 2:1:1; or The display panel includes multiple pixel areas, and in each pixel area, the red sub-unit's orthogonal projection onto the substrate covers two adjacent light-emitting sub-units.

14. A method for manufacturing a display panel, characterized in that, include: Provides substrates and color filter substrates; A light-emitting layer is formed on the substrate, and a wavelength conversion layer is formed on the color filter substrate; The display panel is obtained by aligning a substrate including the light-emitting layer and a color filter substrate including the wavelength conversion layer. The light-emitting layer includes multiple light-emitting sub-units, each of which includes a blue light emitter and a green light emitter; the wavelength conversion layer includes a red sub-unit, a blue sub-unit, and a green sub-unit; the red sub-unit includes a quantum dot red conversion layer and a red color film layer stacked on the quantum dot red conversion layer; the blue sub-unit includes a blue color film layer; and the green sub-unit includes a green color film layer. The orthographic projection of one of the red sub-units on the substrate at least partially overlaps with the orthographic projection of at least one of the light-emitting sub-units on the substrate; The display panel includes multiple pixel areas, and in each pixel area, the ratio of the number of red sub-units, the number of blue sub-units, and the number of green sub-units is 2:1:1; or The display panel includes multiple pixel areas, and in each pixel area, the red sub-unit's orthogonal projection onto the substrate covers two adjacent light-emitting sub-units.

15. A display device, characterized in that, The display device includes a display panel as claimed in any one of claims 1-12.

Images