A display panel, a method for manufacturing the display panel, and a display device.

Abstract

This application provides a display panel, a method for manufacturing the display panel, and a display device, belonging to the field of display technology. The display panel includes: a substrate; a light-emitting layer disposed on one side of the substrate; a quantum dot conversion layer disposed on the light-emitting side of the light-emitting layer, used to convert light emitted by the light-emitting layer into light of a first wavelength or a third wavelength, including a plurality of arrayed light conversion units, and an isolation structure disposed between adjacent light conversion units; wherein, a light-reflecting film layer is disposed on the surface of the isolation structure. This can effectively solve the optical crosstalk problem of the 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] Compared to the light-emitting materials of traditional organic light-emitting diodes (OLEDs), quantum dot materials have a narrower emission spectrum, resulting in better color performance, including color gamut and saturation.

[0003] In existing technologies, traditional quantum dot light emission is usually achieved by using light-emitting diodes (LEDs) as backlights, combined with liquid crystal pixels and quantum dot conversion layers. However, due to the limited light conversion efficiency of the quantum dot conversion layer, the display panel suffers from optical crosstalk problems. Summary of the Invention

[0004] This application provides a display panel, a method for manufacturing the display panel, and a display device, aiming to solve the optical crosstalk problem of the display panel.

[0005] In a first aspect, embodiments of this application provide a display panel, including:

[0006] substrate; A light-emitting layer is disposed on one side of the substrate; A quantum dot conversion layer is disposed on the light-emitting side of the light-emitting layer, including multiple arrayed light conversion units and an isolation structure disposed between adjacent light conversion units. The quantum dot conversion layer is used to convert the first wavelength light emitted by the light-emitting layer into a second wavelength light or a third wavelength light. The surface of the isolation structure is provided with a light-reflecting film layer.

[0007] In one possible implementation, the light-reflecting film layer includes a first film layer and a second film layer, wherein the first film layer is disposed on the surface of the isolation structure and the second film layer is disposed on the surface of the first film layer; The refractive index of the second film layer is greater than that of the first film layer.

[0008] In one possible implementation, the material of the first film layer is SiO; The refractive index of the first film layer is 1.4-1.59; the thickness of the first film layer is 200 Å-1000 Å.

[0009] In one possible implementation, the material of the second film layer is SiN; the refractive index of the second film layer is 1.8-2.1; The thickness of the second film layer is 200A-1000A.

[0010] In one possible implementation, the orthographic projection of the isolation structure onto the substrate does not coincide with the orthographic projection of the light conversion unit onto the substrate; Along the light emission direction of the display panel, the size of the isolation structure gradually decreases, while the size of the light conversion unit gradually increases.

[0011] In one possible implementation, the light-reflecting film covers one side of the isolation structure facing the light conversion unit, and the light-reflecting film is used to reflect light of a first wavelength to the light conversion unit.

[0012] In one possible implementation, the light-emitting layer includes a plurality of light-emitting units, which are disposed in a one-to-one correspondence with a plurality of light-converting units of the quantum dot conversion layer, and the orthographic projection of the light-converting unit on the substrate covers the orthographic projection of the light-emitting unit on the substrate; Preferably, the plurality of light conversion units include a first light conversion unit, a second light conversion unit, and a third light conversion unit; the first light conversion unit and the second light conversion unit each include different quantum dot conversion materials; the first light conversion unit is used to convert the first wavelength light emitted by the light-emitting unit into the second wavelength light, and the second light conversion unit is used to convert the first wavelength light emitted by the light-emitting unit into the third wavelength light; The wavelength of the first wavelength light after passing through the third conversion unit remains unchanged; Preferably, the first light conversion unit includes a first quantum dot material, which emits second wavelength light when excited by the first wavelength light. The second light conversion unit includes a second quantum dot material, which emits the third wavelength light when excited by the first wavelength light. The first wavelength of light emits a blue color, the second wavelength of light emits a red color, and the third wavelength of light emits a green color.

[0013] Secondly, embodiments of this application provide a method for manufacturing a display panel. Provide a substrate; A light-emitting layer is prepared on one side of the substrate; A patterned isolation structure is formed on the light-emitting side of the light-emitting layer, and a light-reflecting film layer is formed on the surface of the isolation structure; Quantum dot luminescent material is filled between the isolation structures to form a quantum dot conversion layer comprising multiple light conversion units; The quantum dot conversion layer is used to convert the first wavelength light emitted by the light-emitting layer into a second wavelength light or a third wavelength light.

[0014] In one possible implementation, the light-reflecting film layer includes a first film layer and a second film layer, wherein a patterned isolation structure is formed on the light-emitting side of the light-emitting layer, and a light-reflecting film layer is formed on the surface of the isolation structure, comprising: A first film layer is deposited on the surface of the isolation structure, and a second film layer is deposited on the surface of the first film layer; Wherein, the refractive index of the second film layer is greater than the refractive index of the first film layer; Preferably, the material of the first film layer is SiO; The refractive index of the first film layer is 1.4-1.59; the thickness of the first film layer is 200 Å-1000 Å. Preferably, the material of the second film layer is SiN; the refractive index of the second film layer is 1.8-2.1; The thickness of the second film layer is 200A-1000A.

[0015] Thirdly, embodiments of this application provide a display device, including a display panel as described in the first aspect above.

[0016] In this embodiment, a light-reflecting film layer is provided on the surface of the isolation structure. This light-reflecting film layer can reflect the first wavelength light, such as blue light, that might be absorbed or scattered by the isolation structure back into the light conversion unit. This significantly improves the utilization rate of the first wavelength light, as the reflective film layer effectively confines the first wavelength light, preventing efficiency loss and color shift caused by its lateral propagation. Simultaneously, it enhances the light intensity entering the light conversion unit, allowing the quantum dot material to be more fully excited, thereby improving the brightness and color purity of red and green light. Furthermore, since the light is confined within its respective light conversion unit, optical crosstalk between different colors of light is greatly suppressed, improving the contrast and color performance of the display panel. Therefore, the solution provided in this embodiment, by providing a light-reflecting film layer on the surface of the isolation structure to solve the optical crosstalk problem of the display panel, can fabricate the isolation structure without relying on black adhesive material and can be well applied to the fabrication of high pixel density display panels. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the 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.

[0018] Figure 1 This is a schematic diagram of the structure of a display panel in the prior art; Figure 2 This is a schematic diagram of the structure of a display panel provided in an embodiment of this application; Figure 3 This is a partially enlarged schematic diagram of a reflective film layer on the surface of an isolation structure provided in an embodiment of this application; Figure 4 This is a schematic flowchart of a display panel manufacturing method provided in an embodiment of this application.

[0019] Explanation of reference numerals in the attached figures: substrate 100; Light-emitting layer 200, light-emitting unit 210; Quantum dot conversion layer 300, light conversion unit 310, first light conversion unit 311, second light conversion unit 312, third light conversion unit 313, isolation structure 320, reflective film layer 330, first film layer 331, second film layer 332. Detailed Implementation

[0020] The features and exemplary embodiments of various aspects of this application will now be described in detail. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only configured to explain this application and are not configured to limit this application. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples of this application.

[0021] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0022] It should be understood that when describing the structure of a component, when referring to a layer or region as being "above" or "on top of" another layer or region, it can mean that it is directly above the other layer or region, or that it contains other layers or regions between it and the other layer or region. Furthermore, if the component is flipped over, that layer or region will be located "below" or "under" the other layer or region.

[0023] In related technologies, the core technology of QD-OLED (Quantum Dot Organic Light Emitting Diode) display panels involves exciting red and green quantum dot materials through a blue OLED emitting layer to directly generate the three primary colors. This combines the narrow bandwidth characteristics (20-40nm full width at half maximum) of quantum dot materials with the self-emissive advantages of OLEDs. The quantum dot layer, containing the quantum dot materials, needs to be placed above the backlight layer to absorb the emitted blue light. Ideally, the blue light emitted by the blue OLED should be completely absorbed by the red or green quantum dots above it and converted into red or green light. However, because the conversion efficiency of quantum dots is not 100%, some blue light directly penetrates the quantum dot layer or leaks out from the gaps, mixing with the red or green light of adjacent sub-pixels, resulting in a decrease in color purity.

[0024] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a display panel in the prior art, provided as an embodiment of this application. Figure 1 The display panel shown includes a first light-emitting unit 1, a second light-emitting unit 2, and a third light-emitting unit 3. Taking the second light-emitting unit 3 as an example, the blue light emitted by it should be completely absorbed by the green quantum dot unit 5 above it and converted into green light. However, since the conversion efficiency of quantum dots is not 100%, the green quantum dot unit 5 cannot completely absorb the blue light emitted by the second light-emitting unit 2. Some of the blue light will penetrate the green quantum dot unit 5 and be emitted laterally, mixing with the red light emitted by the adjacent red quantum dot unit 4. Similarly, the red quantum dot unit 4 cannot completely absorb the blue light emitted by the first light-emitting unit 1. Some of the blue light will penetrate the red quantum dot unit 4 and be emitted laterally, mixing with the red light emitted by the adjacent green quantum dot unit 5. This results in optical crosstalk.

[0025] To address the optical crosstalk issue in QD-OLED display panels, a black vinyl isolation structure 6 is typically placed between adjacent red quantum dot units 4 and green quantum dot units 5 to absorb side-emitted blue light. However, current processes cannot use exposure methods to finely pattern the black vinyl material to form the isolation structure, making the black vinyl isolation structure 6 unsuitable for display panels with high pixel density.

[0026] To solve the above technical problems, such as Figure 2 As shown, Figure 2This is a schematic diagram of the structure of a display panel provided in an embodiment of this application. The display panel includes: substrate 100; A light-emitting layer 200 is disposed on one side of the substrate 100; A quantum dot conversion layer 300 is disposed on the light-emitting side of the light-emitting layer 200, including a plurality of arrayed light conversion units 310 and an isolation structure 320 disposed between adjacent light conversion units, for converting the first wavelength light emitted by the light-emitting layer 200 into a second wavelength or a third wavelength light. The isolation structure 320 has a light-reflecting film layer 330 on its surface.

[0027] In this embodiment, the substrate 100 serves as the carrier of the entire display panel and can be a rigid substrate or a flexible substrate. In a preferred embodiment, the substrate 100 is a transparent substrate, such as a glass substrate, a quartz substrate, or a transparent polyimide (PI) substrate.

[0028] In another implementation, the substrate 100 can also be opaque, such as a metal substrate or a ceramic substrate, depending on the light emission direction of the display panel (top-emitting or bottom-emitting). In this embodiment, taking a bottom-emitting display panel as an example, the substrate 100 is preferably a transparent glass substrate. A thin-film transistor (TFT) array layer (not shown) may be further disposed on the substrate 100 for driving each sub-pixel in the light-emitting layer 200 to emit light.

[0029] A light-emitting layer 200 is disposed on one side of the substrate 100. Specifically, the light-emitting layer 200 can be an organic light-emitting material layer formed by vapor deposition or solution methods (such as inkjet printing or spin coating) or a micro-light-emitting diode chip array formed by direct growth. This embodiment does not limit the specific fabrication method of the light-emitting layer. The light-emitting layer 200 is used to emit light of a first wavelength under the drive of an electrical signal. To adapt to the subsequent quantum dot conversion layer 300, this first wavelength light is preferably short-wavelength, high-energy light, such as blue light or ultraviolet light. In this embodiment, the first wavelength light is blue light, with a peak wavelength range of 440nm-470nm.

[0030] A quantum dot conversion layer 300 is disposed on the light-emitting side of the light-emitting layer 200. Specifically, the quantum dot conversion layer 300 is formed directly or indirectly above the light-emitting layer 200. Its core function is to receive light of the first wavelength emitted by the light-emitting layer 200, such as blue light, and convert a portion of it into light of the second or third wavelength, such as red and green light, thereby achieving full-color display.

[0031] like Figure 2As shown, the quantum dot conversion layer 300 includes a plurality of arrayed light conversion units 310 and an isolation structure 320 disposed between adjacent light conversion units 310. The plurality of light conversion units 310 are arranged in a periodic array, such as a classic RGB (red, green, blue) pixel arrangement or an RGBW (red, green, blue, white) arrangement. Each light conversion unit 310 corresponds to a sub-pixel area of ​​the display panel. The isolation structure 320 physically separates the individual light conversion units 310 to prevent crosstalk between different colors of light.

[0032] In this embodiment, a light-reflecting film layer 330 is provided on the surface of the isolation structure 320. This light-reflecting film layer 330 can reflect first-wavelength light, such as blue light, that was originally directed towards the isolation structure 320 and might be absorbed or scattered back into the light conversion unit 310. This significantly improves the utilization rate of the first-wavelength light, as the reflective film layer effectively confines the first-wavelength light, preventing efficiency loss and color shift caused by its lateral propagation. Simultaneously, it enhances the light intensity entering the light conversion unit 310, allowing the quantum dot material to be more fully excited, thereby improving the brightness and color purity of red and green light. Furthermore, since the light is confined within its respective light conversion unit 310, optical crosstalk between different colors of light is greatly suppressed, improving the contrast and color performance of the display panel. Therefore, the solution provided in this embodiment, by providing a light-reflecting film layer on the surface of the isolation structure to solve the optical crosstalk problem of the display panel, can fabricate the isolation structure without relying on black adhesive material and can be well applied to the fabrication of high-pixel-density display panels.

[0033] In another embodiment of this application, the light-reflecting film layer 330 includes a first film layer 331 and a second film layer 332, wherein the first film layer 331 is disposed on the surface of the isolation structure 320, and the second film layer 332 is disposed on the surface of the first film layer 331. Wherein, the refractive index of the second film layer 332 is greater than the refractive index of the first film layer 331; Preferably, the insulating structure material includes metal.

[0034] Figure 3 This is a partially enlarged schematic diagram of the isolation structure and reflective film layer in a display panel provided as an embodiment of this application. Figure 3 As shown, the light-reflecting film layer 330 disposed on the surface of the isolation structure 320 is not a single material layer, but a composite multilayer film structure, which specifically includes a first film layer 331 and a second film layer 332.

[0035] The first film layer 331 is directly disposed on the surface of the isolation structure 320, while the second film layer 332 is disposed on the surface of the first film layer 331. The refractive indices of the first film layer 331 and the second film layer 332 are designed to match, with the refractive index of the second film layer 332 being greater than that of the first film layer 331.

[0036] In a preferred embodiment, the first film layer 331 is made of a low-refractive-index transparent medium material, such as silicon monoxide (SiO) or other low-refractive-index optical coating materials. The refractive index of the first film layer is 1.4-1.59, for example, it can be 1.41, 1.45, 1.5, 1.51, 1.5, 1.57 or 1.58.

[0037] The thickness of the first film layer 331 is 200A-1000A, which can be designed according to the target reflection wavelength (the first wavelength, i.e., blue light). For example, the thickness can be 210A, 250A, 300A, 400A, 500A, 600A, 800A, 900A or 950A.

[0038] The second film layer 332 is made of a high-refractive-index transparent dielectric material, such as SiN. The refractive index of the second film layer can be 1.8-2.1, for example, 1.81, 1.85, 1.9 or 2.0.

[0039] The thickness of the second film layer 332 also needs to be carefully designed. The thickness of the second film layer 332 is 200A-1000A, for example, the thickness can be 210A, 250A, 300A, 400A, 500A, 600A, 800A, 900A or 950A.

[0040] In this embodiment, when the first wavelength light rays travel from inside the light conversion unit 310 to the sidewall of the isolation structure 320, they first encounter the second film layer 332. Because the second film layer 332 has a high refractive index, the light rays are refracted and enter the second film layer 332. Subsequently, the light rays reach the interface between the second film layer 332 and the first film layer 331. At this interface, since the light rays travel from a high-refractive-index medium to a low-refractive-index medium, from an optically denser medium to an optically less dense medium, total internal reflection (TIR) ​​occurs when the angle of incidence is greater than or equal to the critical angle. The totally internally reflected light rays are reflected back to the second film layer 332 and eventually re-enter the light conversion unit 310. By rationally designing the thickness and refractive index difference between the first film layer 331 and the second film layer 332, extremely high reflectivity (theoretically close to 100%) can be achieved for light rays in a specific wavelength range (e.g., the blue light band).

[0041] In this embodiment, the first film layer 331 is made of SiO with a low refractive index n1 ranging from 1.4 to 1.59, and the second film layer 332 is made of SiN with a high refractive index n2 ranging from 1.8 to 2.1, forming a "low-high" refractive index interface. The critical angle for total internal reflection at this interface is α = arcsin(n1 / n2). The smaller the ratio of n1 / n2, the smaller the critical angle, and the easier it is for total internal reflection to occur. For example, if n1 = 1.45 and n2 = 2.0, then the critical angle α ≈ 46.5°; if n1 = 1.55 and n2 = 1.85, then the critical angle α ≈ 57.0°. Through research, the inventors discovered that when n1 is between 1.45 and 1.55 and n2 is between 1.95 and 2.05, i.e., the refractive index difference between the first film layer 331 and the second film layer 332 is ≥0.4, the critical angle can be controlled between 40° and 60°. This angle range precisely matches the main distribution range of light angles from the light conversion unit 310 to the sidewall of the isolation structure, approximately 30° to 60°. Therefore, most of the oblique light rays that would otherwise leak to adjacent pixels can undergo total internal reflection at this interface and be efficiently returned to the light conversion unit of this pixel.

[0042] Based on refractive index matching, the inventors further discovered that when the thicknesses of the first film layer 331 and the second film layer 332 satisfy a specific optical thickness matching relationship, an interference enhancement effect can be generated, increasing the reflectivity of a specific wavelength (i.e., the first wavelength, blue light, with a peak of approximately 450nm~470nm) to over 95%.

[0043] When the optical thickness (physical thickness × refractive index) of the second film layer 332 is equal to an odd multiple of 1 / 4 of the wavelength of blue light in the medium, this layer can act as a resonant cavity layer, allowing the reflected light to undergo constructive interference with the incident light. Simultaneously, the optical thickness of the first film layer 331 must also be designed to be an integer or half-integer multiple of 1 / 4 of the blue light wavelength to provide anti-reflection or phase compensation. A ratio of the optical thicknesses of the two films (n2d2 / n1d1) falling between 1.2 and 2.0 can form a highly efficient resonant cavity reflection structure, achieving a blue light reflectivity of 96% to 99%. If the thickness deviates from this window—for example, if the thickness of the first film layer is less than 200 Å or greater than 1000 Å, or the thickness of the second film layer is less than 200 Å or greater than 1000 Å—the interference conditions are disrupted, and the blue light reflectivity drops sharply. Therefore, the thickness range of this invention is not arbitrarily chosen but is a key process parameter strictly limited based on the principle of resonant coupling.

[0044] Therefore, this embodiment constructs a reflective film layer 330 composed of a first film layer 331 with a low refractive index and a second film layer 332 with a high refractive index. By utilizing the principle of total internal reflection, it efficiently reflects the first wavelength light propagating laterally back to the light conversion unit 310. This greatly improves the light extraction efficiency while avoiding optical crosstalk between adjacent light conversion units 310, effectively improving the color shift of the display panel.

[0045] Understandably, to achieve a wider wavelength or higher angle of reflection, the light-reflecting film 330 can also be a multilayer film structure composed of alternating stacks of multiple first film layers 331 and second film layers 332, such as (HL)^n or (LH)^n structures, where H represents a high-refractive-index layer, L represents a low-refractive-index layer, and n is the number of periods (usually 2-10). Such a design can form a photonic bandgap, achieving omnidirectional reflection of light in a specific wavelength band.

[0046] In another embodiment of this application, the light-emitting layer 200 includes a plurality of light-emitting units 210, and the plurality of light-emitting units 210 are disposed in a one-to-one correspondence with the plurality of light conversion units 310 of the quantum dot conversion layer 300. The orthogonal projection of the light conversion unit 310 on the substrate 100 covers the orthogonal projection of the light-emitting unit 210 on the substrate 100.

[0047] In this embodiment, the light-emitting layer 200 includes a plurality of independent light-emitting units 210. Each light-emitting unit 210 can be an organic light-emitting region above the pixel electrode (anode) of an OLED, or an independent light-emitting pixel of a Micro-LED. The light-emitting units 210 are arranged in an array on the substrate 100, with each light-emitting unit 210 corresponding to a sub-pixel region.

[0048] This embodiment of the application maximizes light absorption and conversion efficiency by designing the projection area of ​​the light conversion unit 310 to completely cover the projection area of ​​the light emission unit 210. All light rays of the first wavelength emitted by each light emission unit 210 are directly emitted upwards into the interior of the corresponding light conversion unit 310 directly above it. Because the light conversion unit 310 is larger and its boundary extends beyond the boundary of the light emission unit 210, this ensures that even with some alignment deviation, tilted light rays emitted from the edge of the light emission unit 210 will not directly enter adjacent light conversion units, but will still fall within the range of the light conversion unit 310 of the current pixel. This is crucial for ensuring independent light emission of each sub-pixel and avoiding color mixing.

[0049] Simultaneously, combined with the light-reflecting film layer 330 on the sidewall of the isolation structure 320, this coverage relationship forms a highly efficient optical cavity. Blue light emitted from the light-emitting unit 210 enters directly upwards into the quantum dot material or scattering particles of the light conversion unit 310; another portion strikes the sidewall boundary of the light conversion unit 310 at a large angle. Since the boundary of the light conversion unit 310 extends beyond the boundary of the light-emitting unit 210, these large-angle rays first encounter the sidewall of the light conversion unit 310, i.e., the reflective film layer 330 on the isolation structure 320, and are reflected back into the light conversion unit 310, thus gaining a second opportunity to excite the quantum dots or emit light. If the projected area of ​​the light conversion unit 310 is less than or equal to that of the light-emitting unit 210, then the large-angle rays at the edge will directly enter the isolation structure 320 or be reflected to adjacent pixels, causing severe efficiency loss and crosstalk.

[0050] In another embodiment of this application, the orthographic projection of the isolation structure 320 on the substrate 100 does not coincide with the orthographic projection of the light conversion unit 310 on the substrate 100; Along the light emission direction of the display panel, the size of the isolation structure 320 gradually decreases, while the size of the light conversion unit 310 gradually increases. The light-reflecting film 330 covers the side surface of the isolation structure 320 facing the light conversion unit 310, and the light-reflecting film 330 is used to reflect light of the first wavelength to the light conversion unit 310.

[0051] In this embodiment, the isolation structure 320 is wider near the bottom of the substrate 100 and narrower at the top away from the substrate 100. Correspondingly, the light conversion unit 310 has an inverted trapezoidal or conical shape, that is, the bottom (near the light-emitting layer 200) is narrower and the top (light-emitting surface) is wider.

[0052] This morphology can be achieved through specific photolithography processes. For example, when using positive photoresist to form the pattern of the isolation structure 320, the tilt angle of the photoresist sidewalls can be controlled by adjusting parameters such as the exposure focal length and the post-baking temperature. If the material of the isolation structure 320 is negative photoresist, the exposure amount can be controlled to form an inverted trapezoidal (i.e., the top width is greater than the bottom width) opening, so that the material of the subsequently filled light conversion unit 310 naturally forms a shape that is wider at the top and narrower at the bottom.

[0053] In this application, the light conversion unit 310 has the largest size on the light-emitting side, which means that the effective area of ​​light emitted from the display panel is the largest, directly improving the panel's aperture ratio and light emission brightness.

[0054] Meanwhile, the sidewalls of the isolation structure 320 are inclined outwards, extending outwards from the bottom to the top. This inclination angle can be optimized so that the large-angle light emitted from the light-emitting unit 210 and directed towards the sidewall, after being reflected by the reflective film layer 330, tends to be perpendicular to the light-emitting surface of the panel (i.e., the normal direction). This effectively narrows the divergence angle of the emitted beam, improves axial brightness, and guides light that might otherwise be absorbed or cause crosstalk by adjacent pixel structures towards the light-emitting direction.

[0055] Because the isolation structure 320 is wider at the bottom, it can better isolate the first wavelength of light emitted from the light-emitting unit 210 that propagates laterally close to the substrate surface. This light is usually difficult to extract and is one of the main sources of efficiency loss in display panels. The wide-bottom isolation structure, together with its highly reflective sidewall film layer, can effectively reflect this guided light upwards and convert it into usable outgoing light.

[0056] In another embodiment of this application, see also: Figure 2 The plurality of light conversion units 310 include a first light conversion unit 311, a second light conversion unit 312, and a third light conversion unit 313; the first light conversion unit 311 and the second light conversion unit 312 respectively include different quantum dot conversion materials; the first light conversion unit 311 is used to convert the first wavelength light emitted by the light-emitting unit 210 into the second wavelength light, and the second light conversion unit 312 is used to optically convert the first wavelength light emitted by the light-emitting unit 210 into the third wavelength light; The wavelength of the first wavelength light after passing through the third conversion unit 313 remains unchanged.

[0057] The first light conversion unit 311 includes a first quantum dot material, which emits a second wavelength of light when excited by the first wavelength of light. The second light conversion unit 312 includes a second quantum dot material, which emits a third wavelength of light when excited by a first wavelength of light. The first wavelength of light emits a blue color, the second wavelength of light emits a red color, and the third wavelength of light emits a green color.

[0058] In this embodiment, the multiple arrayed light conversion units 310 include at least three functionally different units: a first light conversion unit 311, a second light conversion unit 312, and a third light conversion unit 313. These three units are arranged in a specific periodic order in the display panel.

[0059] The first wavelength of light is blue, the second wavelength is red, and the third wavelength is green. Accordingly, the first quantum dot material emits red light when excited by blue light, with a peak emission wavelength range of, for example, 620 nm-650 nm; the second quantum dot material emits green light when excited by blue light, with a peak emission wavelength range of, for example, 520 nm-550 nm.

[0060] Quantum dot materials include, but are not limited to: core-shell II-VI semiconductor compounds, such as cadmium selenide / cadmium sulfide (CdSe / CdS) and cadmium telluride / cadmium sulfide (CdTe / CdS); III-V semiconductor compounds, such as indium phosphide / zinc sulfide (InP / ZnS); and novel perovskite quantum dots, such as cesium lead bromine / chlorine (CsPbBr3 / CsPbCl3). Among these, InP-based quantum dots, because they do not contain the heavy metal cadmium (Cd), comply with environmental regulations (such as RoHS) and are the preferred material for current high-end display applications. For example, the red quantum dot in the first light conversion unit 311 can be selected as an InP / ZnSe / ZnS core-shell quantum dot, and the green quantum dot in the second light conversion unit 312 can be selected as an InP / ZnSe / ZnS or CdSe / ZnS quantum dot. Quantum dots are typically dispersed in acrylate, epoxy, or polysiloxane photocurable or thermocurable resin matrices and precisely filled into the openings defined by the isolation structure 320 using inkjet printing or photolithography.

[0061] Although the third light conversion unit 313 does not contain quantum dots, it can be filled with light scattering particles, such as TiO2, ZrO2 or SiO2 nanoparticles, or simply filled with transparent organic resin in order to improve the emission angle and brightness uniformity of blue light.

[0062] This application embodiment uses a high-brightness, high-efficiency blue light-emitting unit as the backlight for all sub-pixels, and then uses quantum dot materials to convert some of the blue light down into red and green light. This avoids the direct fabrication of red and green light-emitting units with relatively low efficiency and stability (especially in OLED and QLED technologies), greatly simplifying the manufacturing process and improving the overall performance.

[0063] Based on the same inventive concept, such as Figure 4 As shown, Figure 4 This is a flowchart illustrating a method for manufacturing a display panel according to an embodiment of this application. The method includes: S101, Provide a substrate.

[0064] The substrate has a thin film transistor (TFT) array layer, which is used to drive each sub-pixel in the light-emitting layer 200 to emit light.

[0065] S102. Prepare a light-emitting layer on one side of the substrate.

[0066] The light-emitting layer 200 can be an organic light-emitting material layer formed by vapor deposition or solution method (such as inkjet printing or spin coating) or a micro light-emitting diode chip array formed by direct growth. The specific preparation method of the light-emitting layer is not limited in the embodiments of this application. The light-emitting layer 200 is used to emit light of the first wavelength under the drive of an electrical signal.

[0067] S103. A patterned isolation structure is formed on the light-emitting side of the light-emitting layer, and a light-reflecting film layer is formed on the surface of the isolation structure.

[0068] S104. Fill the space between the isolation structures with quantum dot luminescent material to form a quantum dot conversion layer comprising multiple light conversion units.

[0069] The quantum dot conversion layer is used to convert the first wavelength light emitted by the light-emitting layer into a second wavelength light or a third wavelength light.

[0070] The quantum dot conversion layer includes multiple arrayed light conversion units and isolation structures disposed between adjacent light conversion units. The multiple light conversion units are arranged in a periodic array, such as the classic RGB (red, green, blue) pixel arrangement or RGBW (red, green, blue, white) arrangement. Each light conversion unit 310 corresponds to a sub-pixel area of ​​the display panel. The isolation structures physically separate the individual light conversion units to prevent crosstalk between different colors of light. In this embodiment, a light-reflecting film layer is provided on the surface of the isolation structure. This light-reflecting film layer can reflect the first wavelength light, such as blue light, that might be absorbed or scattered by the isolation structure back into the light conversion unit. This significantly improves the utilization rate of the first wavelength light, as the reflective film layer effectively confines the first wavelength light, preventing efficiency loss and color shift caused by its lateral propagation. Simultaneously, it enhances the light intensity entering the light conversion unit 310, allowing the quantum dot material to be more fully excited, thereby improving the brightness and color purity of red and green light. Furthermore, since the light is confined within its respective light conversion unit, optical crosstalk between different colors of light is greatly suppressed, improving the contrast and color performance of the display panel. Therefore, the solution provided in this embodiment, by providing a light-reflecting film layer on the surface of the isolation structure to solve the optical crosstalk problem of the display panel, can fabricate the isolation structure without relying on black adhesive material and can be well applied to the fabrication of high pixel density display panels.

[0071] In another embodiment of this application, the light-reflecting film layer includes a first film layer and a second film layer. Specifically, the formation of a patterned isolation structure on the light-emitting side of the light-emitting layer and the formation of the light-reflecting film layer on the surface of the isolation structure can be implemented as follows: A first film layer is deposited on the surface of the isolation structure, and a second film layer is deposited on the surface of the first film layer; The refractive index of the second film layer is greater than that of the first film layer.

[0072] This application embodiment constructs a reflective film layer composed of a first film layer with a low refractive index and a second film layer with a high refractive index. By utilizing the principle of total internal reflection, it efficiently reflects the first wavelength light propagating laterally back to the light conversion unit. This greatly improves the light extraction efficiency while avoiding optical crosstalk between adjacent light conversion units, effectively improving the color shift of the display panel.

[0073] This application also provides a display device, including any of the display panels described in the above embodiments, wherein the display device can be an electronic device such as a smartphone, tablet computer, or laptop computer.

[0074] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0075] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A display panel, characterized in that, include: substrate; A light-emitting layer is disposed on one side of the substrate; A quantum dot conversion layer is disposed on the light-emitting side of the light-emitting layer, including multiple arrayed light conversion units and an isolation structure disposed between adjacent light conversion units. The quantum dot conversion layer is used to convert the first wavelength light emitted by the light-emitting layer into a second wavelength light or a third wavelength light. The surface of the isolation structure is provided with a light-reflecting film layer.

2. The display panel according to claim 1, characterized in that, The light-reflecting film layer includes a first film layer and a second film layer, wherein the first film layer is disposed on the surface of the isolation structure, and the second film layer is disposed on the surface of the first film layer; The refractive index of the second film layer is greater than that of the first film layer.

3. The display panel according to claim 2, characterized in that, The material of the first film layer is SiO; The refractive index of the first film layer is 1.4-1.59; the thickness of the first film layer is 200 Å-1000 Å.

4. The display panel according to claim 2 or 3, characterized in that... The material of the second film is SiN; the refractive index of the second film is 1.8-2.1; and the thickness of the second film is 200 Å-1000 Å.

5. The display panel according to claim 4, characterized in that, The orthographic projection of the isolation structure on the substrate does not coincide with the orthographic projection of the light conversion unit on the substrate; Along the light emission direction of the display panel, the size of the isolation structure gradually decreases, while the size of the light conversion unit gradually increases.

6. The display panel according to claim 5, characterized in that, The light-reflecting film covers the side surface of the isolation structure facing the light conversion unit, and the light-reflecting film is used to reflect light of the first wavelength to the light conversion unit.

7. The display panel according to claim 1 or 2, characterized in that, The light-emitting layer includes a plurality of light-emitting units, and the plurality of light-emitting units are arranged in a one-to-one correspondence with the plurality of light conversion units of the quantum dot conversion layer. The orthogonal projection of the light conversion unit on the substrate covers the orthogonal projection of the light-emitting unit on the substrate. Preferably, the plurality of light conversion units include a first light conversion unit, a second light conversion unit, and a third light conversion unit; the first light conversion unit and the second light conversion unit each include different quantum dot conversion materials; the first light conversion unit is used to convert the first wavelength light emitted by the light-emitting unit into the second wavelength light, and the second light conversion unit is used to convert the first wavelength light emitted by the light-emitting unit into the third wavelength light; The wavelength of the first wavelength light after passing through the third conversion unit remains unchanged; Preferably, the first light conversion unit includes a first quantum dot material, which emits second wavelength light when excited by the first wavelength light. The second light conversion unit includes a second quantum dot material, which emits the third wavelength light when excited by the first wavelength light. The first wavelength of light emits a blue color, the second wavelength of light emits a red color, and the third wavelength of light emits a green color.

8. A method for manufacturing a display panel, characterized in that, Provide a substrate; A light-emitting layer is prepared on one side of the substrate; A patterned isolation structure is formed on the light-emitting side of the light-emitting layer, and a light-reflecting film layer is formed on the surface of the isolation structure; Quantum dot luminescent material is filled between the isolation structures to form a quantum dot conversion layer comprising multiple light conversion units; The quantum dot conversion layer is used to convert the first wavelength light emitted by the light-emitting layer into a second wavelength light or a third wavelength light.

9. The preparation method according to claim 8, characterized in that, The light-reflecting film layer includes a first film layer and a second film layer. A patterned isolation structure is formed on the light-emitting side of the light-emitting layer, and a light-reflecting film layer is formed on the surface of the isolation structure, including: A first film layer is deposited on the surface of the isolation structure, and a second film layer is deposited on the surface of the first film layer; Wherein, the refractive index of the second film layer is greater than the refractive index of the first film layer; Preferably, the material of the first film layer is SiO; The refractive index of the first film layer is 1.4-1.59; the thickness of the first film layer is 200 Å-1000 Å. Preferably, the material of the second film layer is SiN; the refractive index of the second film layer is 1.8-2.1; The thickness of the second film layer is 200A-1000A.

10. A display device, characterized in that, The electronic device includes a display panel as described in any one of claims 1-7.

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