Color conversion substrate, manufacturing method therefor, and display panel

Abstract

Provided in the embodiments of the present disclosure are a color conversion substrate, a manufacturing method therefor, and a display panel, which relate to the technical field of display, and are used for improving the color purity displayed by display panels. The color conversion substrate comprises a base substrate, a color conversion layer and a cholesteric liquid crystal layer. The color conversion layer is located on one side of the base substrate; the color conversion layer comprises a first color conversion portion; and the first color conversion portion is configured to convert into second-color light rays first-color light rays emitted to the first color conversion portion. The cholesteric liquid crystal layer comprises a first cholesteric liquid crystal portion located between the base substrate and the first color conversion portion; and the first cholesteric liquid crystal portion is configured to reflect unconverted light rays of the first-color light rays back to the first color conversion portion. The color conversion substrate is used for performing color conversion.

Description

Color conversion substrate and preparation method thereof, and display panel

[0001] This application claims priority to Chinese patent application No. 202311270313.4 filed on September 27, 2023, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present disclosure relates to the field of display technology, and in particular to a color conversion substrate and a preparation method thereof, and a display panel. Background Art

[0003] In the display field, the use of color conversion substrates to achieve full-color display in display panels is widely used. Specifically, light emitted by the display panel's light-emitting substrate serves as excitation light, stimulating the color conversion material in the color conversion substrate. This converts at least part of the excitation light into different colors, causing the display panel to emit red, green, and blue light, thus achieving full color.

[0004] Summary of the Invention

[0005] In one aspect, a color conversion substrate is provided. The color conversion substrate includes a substrate, a color conversion layer, and a cholesteric liquid crystal layer. The color conversion layer is located on one side of the substrate and includes a first color conversion portion. The first color conversion portion is configured to convert a first color light incident on the first color conversion portion into a second color light. The cholesteric liquid crystal layer includes a first cholesteric liquid crystal portion located between the substrate and the first color conversion portion. The first cholesteric liquid crystal portion is configured to reflect unconverted light of the first color light back to the first color conversion portion.

[0006] In some embodiments, the color conversion layer further includes a second color conversion portion arranged along a first direction with the first color conversion portion, where the first direction intersects the thickness direction of the substrate. The second color conversion portion is configured to convert light of the first color directed toward the second color conversion portion into light of a third color. The cholesteric liquid crystal layer further includes a second cholesteric liquid crystal portion located between the substrate and the second color conversion portion. The second cholesteric liquid crystal portion is configured to reflect unconverted light of the first color back to the second color conversion portion.

[0007] In some embodiments, the cholesteric liquid crystals in the first cholesteric liquid crystal portion and the second cholesteric liquid crystal portion are in a planar state.

[0008] In some embodiments, the color conversion substrate further includes a light-transmitting portion arranged along a first direction with the color conversion layer, the first direction intersecting the thickness direction of the substrate, and the light of the first color passing through the light-transmitting portion. The cholesteric liquid crystal layer further includes a third cholesteric liquid crystal portion located between the substrate and the light-transmitting portion; the third cholesteric liquid crystal portion is configured to disperse the portion of the first color light passing through the light-transmitting portion near the normal viewing angle toward a wide viewing angle.

[0009] In some embodiments, the cholesteric liquid crystal in the third cholesteric liquid crystal portion is in a focal conic state.

[0010] In some embodiments, the first cholesteric liquid crystal portion includes a first chiral liquid crystal portion and a second chiral liquid crystal portion stacked together. The helical direction of the liquid crystal molecules in the first chiral liquid crystal portion is opposite to the helical direction of the liquid crystal molecules in the second chiral liquid crystal portion. When the cholesteric liquid crystal layer further includes a second cholesteric liquid crystal portion, the second cholesteric liquid crystal portion includes a third chiral liquid crystal portion and a fourth chiral liquid crystal portion stacked together. The helical direction of the liquid crystal molecules in the third chiral liquid crystal portion is opposite to the helical direction of the liquid crystal molecules in the fourth chiral liquid crystal portion.

[0011] In some embodiments, the helical pitch of the liquid crystal molecules in the first cholesteric liquid crystal portion is greater than or equal to 270 nm and less than or equal to 310 nm. The helical pitch of the liquid crystal molecules in the second cholesteric liquid crystal portion is greater than or equal to 270 nm and less than or equal to 310 nm.

[0012] In some embodiments, the first color light is blue light. The central reflection wavelength of the first cholesteric liquid crystal portion is greater than or equal to 450 nm and less than or equal to 470 nm. The central reflection wavelength of the second cholesteric liquid crystal portion is greater than or equal to 450 nm and less than or equal to 470 nm.

[0013] In some embodiments, the half-value width of the transmission spectrum of the first cholesteric liquid crystal portion is greater than or equal to 70 nm and less than or equal to 100 nm. The half-value width of the transmission spectrum of the second cholesteric liquid crystal portion is greater than or equal to 70 nm and less than or equal to 100 nm.

[0014] In some embodiments, the color conversion substrate further includes an alignment layer positioned between the cholesteric liquid crystal layer and the substrate. The alignment layer includes a first alignment portion, a second alignment portion, and a third alignment portion arranged along a first direction. The first alignment portion is configured to align the liquid crystal molecules in the first cholesteric liquid crystal portion. The second alignment portion is configured to align the liquid crystal molecules in the second cholesteric liquid crystal portion. The third alignment portion is configured to align the liquid crystal molecules in the third cholesteric liquid crystal portion.

[0015] In some embodiments, the haze of the third cholesteric liquid crystal portion is greater than or equal to 3% and less than or equal to 8%.

[0016] In some embodiments, the third cholesteric liquid crystal portion has a transmittance greater than or equal to 90% for light in a first wavelength band, wherein the minimum wavelength of the first wavelength band is 450 nm and the maximum wavelength of the first wavelength band is 470 nm.

[0017] In some embodiments, the thickness of the cholesteric liquid crystal layer is greater than or equal to 2 μm and less than or equal to 6 μm.

[0018] In some embodiments, the material of the first color converter includes a first quantum dot material, and the material of the second color converter includes a second quantum dot material.

[0019] In some embodiments, the color conversion substrate further includes a blocking pattern. The blocking pattern includes a plurality of first openings. The first color conversion portion and the first cholesteric liquid crystal portion are located within one first opening. The second color conversion portion and the second cholesteric liquid crystal portion are located within another first opening. The light-transmitting portion and the third cholesteric liquid crystal portion are located within yet another first opening.

[0020] In some embodiments, the color conversion substrate further includes a light-blocking layer positioned between the cholesteric liquid crystal layer and the substrate. The light-blocking layer includes a light-absorbing pattern and multiple color filter portions. The light-absorbing pattern includes multiple second openings, each of which is positioned opposite the multiple first openings. The multiple color filter portions are positioned on a side of the substrate proximal to the cholesteric liquid crystal layer; each color filter portion is disposed within one of the second openings. The multiple color filter portions include a first color filter portion positioned opposite the first color conversion portion, a second color filter portion positioned opposite the second color conversion portion, and a third color filter portion positioned opposite the light-transmitting portion.

[0021] In another aspect, a method for preparing a color conversion substrate is provided. The method includes providing a substrate. A cholesteric liquid crystal layer is formed on one side of the substrate; the cholesteric liquid crystal layer includes a first cholesteric liquid crystal portion. A color conversion layer is formed on a side of the cholesteric liquid crystal layer away from the substrate; the color conversion layer includes a first color conversion portion located on the side of the first cholesteric liquid crystal portion away from the substrate. The first color conversion portion is configured to convert a first color light incident on the first color conversion portion into a second color light. The first cholesteric liquid crystal portion is configured to reflect unconverted light from the first color light back to the first color conversion portion.

[0022] In some embodiments, the color conversion substrate further includes a light-transmitting portion arranged along a first direction with the color conversion layer, the first direction intersecting the thickness direction of the substrate; the light of the first color can pass through the light-transmitting portion. The color conversion layer further includes a second color conversion portion arranged along the first direction with the first color conversion portion, the second color conversion portion being configured to convert the light of the first color directed toward the second color conversion portion into light of a third color. Forming a cholesteric liquid crystal layer on one side of the substrate includes forming an initial cholesteric liquid crystal layer on one side of the substrate, the initial cholesteric liquid crystal layer including a first initial cholesteric liquid crystal portion, a second initial cholesteric liquid crystal portion, and a third initial cholesteric liquid crystal portion. The first initial cholesteric liquid crystal portion is formed into a first cholesteric liquid crystal portion, and the second initial cholesteric liquid crystal portion is formed into a second cholesteric liquid crystal portion; the second cholesteric liquid crystal portion is located between the substrate and the second color conversion portion; and the second cholesteric liquid crystal portion is configured to reflect unconverted light of the first color back to the second color conversion portion. The third initial cholesteric liquid crystal portion forms a third cholesteric liquid crystal portion located between the substrate and the light-transmitting portion. The third cholesteric liquid crystal portion is configured to disperse the portion of the first color light passing through the light-transmitting portion close to the normal viewing angle toward a wide viewing angle.

[0023] In another aspect, a display panel is provided. The display panel includes: a color conversion substrate as described in any of the above embodiments and a light-emitting substrate. The light-emitting substrate is opposite to the color conversion substrate and is configured to emit light of a first color.

[0024] In some embodiments, the light-emitting substrate includes any one of an OLED light-emitting substrate, an LED light-emitting substrate, a Micro LED light-emitting substrate, and a Mini LED light-emitting substrate.

[0025] In some embodiments, the light-emitting substrate is an OLED light-emitting substrate, comprising a cathode and an anode disposed opposite each other, and at least two light-emitting units disposed between the cathode and the anode. The light-emitting units include a light-emitting layer configured to emit light of a first color toward the color conversion substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] To more clearly illustrate the technical solutions of the present disclosure, the following briefly introduces the drawings required for use in some embodiments of the present disclosure. Obviously, the drawings described below are only drawings of some embodiments of the present disclosure, and those skilled in the art can also derive other drawings based on these drawings. Furthermore, the drawings described below are schematic diagrams and are not intended to limit the actual dimensions of the products, actual processes of the methods, actual timing of signals, and the like involved in the embodiments of the present disclosure.

[0027] FIG1 is a structural diagram of a display panel according to some embodiments;

[0028] FIG2 is a light emission diagram of a color conversion substrate according to some embodiments;

[0029] FIG3 is a structural diagram of a color conversion substrate according to some embodiments;

[0030] FIG4 is a structural diagram of a color conversion substrate according to yet other embodiments;

[0031] FIG5 is a light emission diagram of a color conversion substrate according to still other embodiments;

[0032] FIG6 is a structural diagram of a display panel according to yet other embodiments;

[0033] FIG7 is a flow chart of preparing a color conversion substrate according to some embodiments;

[0034] FIG8 is a flow chart of preparing a cholesteric liquid crystal layer according to some embodiments;

[0035] FIG9 is a diagram illustrating a process for preparing a cholesteric liquid crystal layer according to some embodiments;

[0036] FIG10 is a structural diagram of a display panel according to yet other embodiments;

[0037] FIG11 is a microscopic morphology diagram of a first cholesteric liquid crystal portion according to some embodiments;

[0038] FIG12 is a polarizing microscope texture image of the first cholesteric liquid crystal portion according to some embodiments;

[0039] FIG13 is a transmission spectrum diagram of a first cholesteric liquid crystal portion according to some embodiments;

[0040] FIG14 is a microscopic morphology diagram of a third cholesteric liquid crystal portion according to some embodiments;

[0041] FIG15 is a polarization microscope texture image of the third cholesteric liquid crystal portion according to some embodiments;

[0042] FIG. 16 is a diagram illustrating angular light intensity distribution of a third cholesteric liquid crystal portion according to some embodiments. DETAILED DESCRIPTION

[0043] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present disclosure. Obviously, the embodiments described are only some embodiments of the present disclosure, not all embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of the present disclosure.

[0044] Unless the context requires otherwise, throughout the specification and claims, the term "comprise" and its other forms, such as the third person singular form "comprises" and the present participle form "comprising", are to be interpreted as open and inclusive, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "example", "specific example" or "some examples" are intended to indicate that the particular features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the particular features, structures, materials or characteristics may be included in any one or more embodiments or examples in any appropriate manner.

[0045] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, "plurality" means two or more.

[0046] “At least one of A, B and C” has the same meaning as “at least one of A, B or C” and both include the following combinations of A, B and C: A only, B only, C only, the combination of A and B, the combination of A and C, the combination of B and C, and the combination of A, B and C.

[0047] “A and / or B” includes the following three combinations: A only, B only, and a combination of A and B.

[0048] The use of "adapted to" or "configured to" herein is intended to be open and inclusive language that does not exclude devices adapted or configured to perform additional tasks or steps.

[0049] Additionally, the use of “based on” is meant to be open and inclusive, as a process, step, calculation, or other action “based on” one or more stated conditions or values ​​may, in practice, be based on additional conditions or values ​​beyond those stated.

[0050] As used herein, "about," "substantially," or "approximately" includes the stated value and an average value that is within an acceptable range of deviation from the particular value as determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

[0051] As used herein, "parallel", "perpendicular", and "equal" include the situations described and situations similar to the situations described, and the range of the similar situations is within an acceptable deviation range, wherein the acceptable deviation range is as determined by a person of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of the specific quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, wherein the acceptable deviation range of approximate parallelism can be, for example, a deviation within 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, wherein the acceptable deviation range of approximate perpendicularity can also be, for example, a deviation within 5°. "Equal" includes absolute equality and approximate equality, wherein the acceptable deviation range of approximate equality can be, for example, that the difference between the two equals is less than or equal to 5% of either one.

[0052] It will be understood that when a layer or element is referred to as being on another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may be present therebetween.

[0053] Exemplary embodiments are described herein with reference to cross-sectional and / or plan views that are idealized exemplary drawings. In the drawings, the thickness of layers and the area of ​​regions are exaggerated for clarity. Therefore, variations in shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are contemplated. Therefore, the exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but rather include deviations in shape due to, for example, manufacturing. For example, an etched region shown as a rectangle will typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the actual shape of regions of the device and are not intended to limit the scope of the exemplary embodiments.

[0054] It should be noted that, in the drawings of this disclosure, references such as 11 to 1 indicate that component 11 belongs to component 1. For example, references such as 121 to 120 in FIG1 indicate that first color conversion portion 121 belongs to color conversion layer 120. The same description applies to other similar reference numerals in the drawings. References such as 1 / 2 in the drawings of this disclosure indicate that both structure 1 and structure 2 can refer to such structures. For example, references such as 131 / 132 in FIG3 indicate that first cholesteric liquid crystal portion 131 and second cholesteric liquid crystal portion 132 can refer to such structures. The same description applies to other similar reference numerals in the drawings.

[0055] Currently, in the display field, display panels mainly achieve full-color display through the following three methods.

[0056] The first method is the RGB pixel juxtaposition method, which utilizes three luminescent materials—R (red), G (green), and B (blue)—to emit light independently. In this method, R (red), G (green), and B (blue) are also called the three primary colors, and while these colors are relatively pure, they are also relatively expensive. For example, for light-emitting devices such as OLEDs, this method can use a fine metal mask and vapor deposition to create OLED light-emitting devices of different colors.

[0057] The second method is a method of using a combination of a white light emitting substrate (e.g., a white light LED) and a color filter. In this method, a white light emitting device emits white light as a backlight source. The white light is filtered into red light, green light, and blue light through a color filter. This method is relatively low-cost. However, due to the presence of color filters, there are certain limitations in light transmittance and light color purity. Therefore, in theory, the combination of a white light emitting device and a color filter is inferior to the RGB pixel juxtaposition method in terms of brightness, contrast, color, and energy saving.

[0058] The third method, as described in the background and shown in Figure 1, utilizes a combination of a light-emitting substrate 200 and a color conversion substrate 100. In this method, light (e.g., blue light) emitted by the light-emitting substrate 200 of the display panel 1000 serves as excitation light to excite the color conversion material in the color conversion substrate 100. This excitation light undergoes color conversion, causing the display panel 1000 to emit red, green, and blue light, thereby achieving full color. For example, the combination of a blue OLED light-emitting device and the color conversion substrate 100 can utilize an open mask, thereby reducing process complexity and improving light energy utilization. Therefore, the use of the color conversion substrate 1000 to achieve full-color display in the display panel 1000 has gained widespread application.

[0059] In some embodiments, as shown in FIG1 , in a method of combining a light-emitting substrate 200 and a color conversion substrate 100, the region emitting the first color light L1 corresponds to the first sub-pixel region AA, the region emitting the second color light L2 corresponds to the second sub-pixel region BB, and the region emitting the third color light L3 corresponds to the third sub-pixel region CC. The first color light L1 is, for example, blue light, the second color light L2 is, for example, red light, and the third color light L3 is, for example, green light.

[0060] In some embodiments, the excitation light emitted by the light-emitting substrate 200 is a first color light L1. In this case, the first color light L1 located in the first sub-pixel region AA can be emitted directly without passing through a color conversion material. The first color light L1 located in the second sub-pixel region BB is converted into a second color light L2 by a color conversion material corresponding to the second color and then emitted. The first color light L1 located in the third sub-pixel region CC is converted into a third color light L3 by a color conversion material corresponding to the third color and then emitted.

[0061] In some implementations, the color conversion material in the color conversion substrate fails to completely convert the first color light L1 (e.g., blue light) emitted by the light-emitting substrate, causing the unconverted first color light L1 to be emitted from the second sub-pixel region BB and / or the third sub-pixel region CC. This leads to leakage of the first color light L1, resulting in the second color light L2 (e.g., red light) emitted from the second sub-pixel region BB being doped with the first color light L1 (e.g., blue light), and / or the third color light L3 (e.g., green light) emitted from the third sub-pixel region CC being doped with the first color light L1 (e.g., blue light). This reduces the color purity of the display panel and affects the display quality.

[0062] In other implementations, the film layer containing the color-conversion material in the color-conversion substrate is the color-conversion layer. The external quantum efficiency (EQE) of the color-conversion layer is affected by factors such as the quantum yield of the color-conversion material and the light extraction efficiency. Due to limitations in the light extraction efficiency of the color-conversion layer, the external quantum efficiency of the color-conversion layer is also limited, and cannot meet the efficiency requirements of the display panel.

[0063] In some other implementations, there are three methods to improve the blue light leakage problem. In the first method, the color conversion material is a quantum dot material, and the optical density of the quantum dot material is increased to improve the blue light leakage problem. However, when the optical density of the quantum dot material increases, it is easy to have poor dispersion, resulting in a decrease in quantum yield (QY). At the same time, quantum dot materials with high optical density may lead to a decrease in optical conversion efficiency. The second method is to superimpose a color filter containing a dye on the light-emitting side of the color conversion substrate to absorb the leaked blue light and improve the display contrast. However, with this method, the blue light absorbed by the color filter will be wasted and difficult to be effectively utilized. The third method is to infiltrate scattering particles such as TiO2 and SiO2 into the color conversion layer to increase the utilization rate of the first color light (for example, blue light). However, the blended quantum dots and inorganic scattering particles have problems such as easy aggregation, easy quenching, self-absorption and stability.

[0064] Based on this, as shown in Figures 1 and 2, some embodiments of the present disclosure provide a color conversion substrate 100. The color conversion substrate 100 includes a substrate 110, a color conversion layer 120, and a cholesteric liquid crystal layer 130. The color conversion layer 120 is located on one side of the substrate 110 and includes a first color conversion portion 121. The first color conversion portion 121 is configured to convert a first color light L1 incident on the first color conversion portion 121 into a second color light L2. The cholesteric liquid crystal layer 130 includes a first cholesteric liquid crystal portion 131 located between the substrate 110 and the first color conversion portion 121. The first cholesteric liquid crystal portion 131 is configured to reflect unconverted light from the first color light L1 back to the first color conversion portion 121.

[0065] In some examples, the substrate 110 may include an insulating material such as glass, plastic, quartz, resin, etc. The substrate 110 may include a material selected from materials having excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and waterproofness.

[0066] Exemplarily, the light transmittance of the substrate 110 is greater than or equal to 99.5%. For example, the light transmittance of the substrate 110 may be 99.5%, 99.6%, 99.7%, 99.8%, or 99.9%. In this way, the light converted by the color conversion layer 120 (for example, the second color light L2 or the third color light L3) and the first color light L1 emitted from the first pixel area AA can be emitted from the substrate 110, thereby improving luminous efficiency.

[0067] Exemplarily, the refractive index of the substrate 110 is less than or equal to 1.30. For example, the refractive index of the substrate 110 may be 1.10, 1.15, 1.20, 1.25, or 1.30. This prevents the light converted by the color conversion layer 120 (e.g., the second color light L2 or the third color light L3) and the first color light L1 emitted from the first pixel area AA from being reflected at the substrate 110, thereby improving luminous efficiency.

[0068] In the aforementioned color conversion substrate 100, as shown in FIG2 , the color conversion layer 120 is a film layer within the color conversion substrate 100 that implements the color conversion function. The first color conversion portion 121 may be the portion of the color conversion layer 120 located in the second sub-pixel region BB and may contain a color conversion material corresponding to the second color. Thus, first color light L1 incident on the first color conversion portion 121 may be converted into second color light L2. For example, the first color light L1 may be blue light, and the second color light L2 may be red light.

[0069] Illustratively, the thickness of the first color conversion portion 121 may be 8 μm to 12 μm. For example, the thickness of the first color conversion portion 121 may be 8 μm, 9 μm, 10 μm, 11 μm, or 12 μm.

[0070] In the related art, cholesteric liquid crystal (CLC) is a one-dimensional photonic crystal. Unlike other nematic or smectic liquid crystal materials, CLC molecules are flat and arranged in layers. Within each layer, the molecules are parallel to each other, with their long axes parallel to the layer plane. The directions of the long axes of the molecules in different layers vary slightly, forming a helical structure along the layer normal. Due to its unique helical twisted structure, CLC possesses unique optical properties, such as optical rotation and selective reflection. Cholesteric liquid crystals with different helical pitches have different reflection bands (also known as reflection windows), allowing them to selectively reflect light with wavelengths within their reflection bands while transmitting light with wavelengths outside of their reflection bands. Therefore, it is possible to produce CLCs that reflect red light, green light, or blue light, respectively.

[0071] In the color conversion substrate 100 , as shown in FIG. 2 , the material of the cholesteric liquid crystal layer 130 may include cholesteric liquid crystals that reflect the first color light L1 . Thus, the first color light L1 , such as blue light, may be reflected.

[0072] As can be understood, as shown in FIG2 , since the first cholesteric liquid crystal region 131 is located between the substrate 110 and the first color conversion region 121, when the material of the first cholesteric liquid crystal region 131 includes cholesteric liquid crystals that reflect the first color light L1, the first color light L1 that has passed through the first color conversion region 121 but has not been converted can be reflected back by the first cholesteric liquid crystal region 131 into the first color conversion region 121, exciting the color conversion material in the first color conversion region 121 and being converted into the second color light L2. This reduces leakage of the first color light L1 from the second sub-pixel region BB, resulting in a relatively high color purity of the second color light L2 emitted from the second sub-pixel region BB, thereby improving the color purity of the display panel 1000. This also prevents the leakage of the first color light L1 from entering adjacent sub-pixels and causing crosstalk, thereby widening the color gamut. Furthermore, it improves the light extraction efficiency of the first color conversion region 121 in the color conversion layer 120, thereby enhancing the external quantum efficiency of the color conversion layer 120.

[0073] In some embodiments, the material of the first color conversion portion 121 includes a first quantum dot material.

[0074] As can be appreciated, quantum dot materials offer advantages such as high brightness, high color volume, and high efficiency. When the first color conversion portion 121 comprises the first quantum dot material, the first quantum dot material can be excited by the first color light L1 and emit the second color light L2. Furthermore, the emitted second color light L2 has a relatively high brightness, thereby enhancing the display quality of the display panel 1000.

[0075] Exemplarily, the first quantum dot material can be CdSe, CdSe / ZnS, InP, CuInS2 (abbreviated as CIS), AgInS2 (abbreviated as AIS), AgGaS2 (abbreviated as AGS), or a perovskite quantum dot material. Among them, CdSe / ZnS is a quantum dot material with CdSe as the core and ZnS as the shell.

[0076] For example, the peak wavelength of the photoluminescence spectrum of the first quantum dot material can be in the range of 625 nm to 645 nm. For example, the peak wavelength of the photoluminescence spectrum of the first quantum dot material can be 625 nm, 630 nm, 635 nm, 640 nm, or 645 nm. In this case, the light emitted by the first quantum dot material (i.e., the second color light L2) is red light.

[0077] For example, the full width at half maximum (FWHM) of the photoluminescence spectrum of the first quantum dot material can be in the range of 15 nm to 35 nm. For example, the full width at half maximum (FWHM) of the photoluminescence spectrum of the first quantum dot material can be 15 nm, 20 nm, 25 nm, 30 nm, or 35 nm. In this way, the color purity of the second color light L2 converted by the first quantum dot material can be improved.

[0078] Exemplarily, the color coordinate CIEx of the light emitted by the first quantum dot material can be in the range of 0.685 to 0.710; for example, the color coordinate CIEx of the light emitted by the first quantum dot material can be 0.685, 0.690, 0.695, 0.700, 0.705 or 0.710, etc. In this case, the light emitted by the first quantum dot material (i.e., the second color light L2) is red light. It should be noted that the color coordinate CIEx refers to the color coordinate in the CIE chromaticity diagram, which is a color system created by the International Commission on Illumination (CIE). In this color system, color attributes can be represented by chromaticity coordinates CIEx and CIEy.

[0079] In some examples, the material of the first color conversion portion 121 also includes a first light-transmitting main material, such as a light-transmitting adhesive, in which the first quantum dot material is dispersed. Furthermore, the doping amount of the first quantum dot material is between 20 wt% and 50 wt%. For example, the doping amount of the first quantum dot material can be 20 wt%, 30 wt%, 42 wt%, or 50 wt%.

[0080] In some embodiments, as shown in Figures 1 and 2 , the color conversion layer 120 further includes a second color conversion portion 122 arranged along a first direction X with the first color conversion portion 121. The first direction X intersects the thickness direction Y of the substrate 110. The second color conversion portion 122 is configured to convert the first color light L1 incident on the second color conversion portion 122 into a third color light L3. The cholesteric liquid crystal layer 130 further includes a second cholesteric liquid crystal portion 132 located between the substrate 110 and the second color conversion portion 122. The second cholesteric liquid crystal portion 132 is configured to reflect unconverted light from the first color light L1 back to the second color conversion portion 122.

[0081] The second color conversion portion 122 may be the portion of the color conversion layer 120 located in the third sub-pixel region CC and may include a color conversion material corresponding to the third color. Thus, the first color light L1 incident on the second color conversion portion 122 may be converted into the third color light L3. The first color light L1 may be, for example, blue light, and the second color light L2 may be, for example, green light.

[0082] As can be understood, as shown in FIG2 , because the second cholesteric liquid crystal region 132 is located between the substrate 110 and the second color conversion region 122, when the material of the second cholesteric liquid crystal region 132 includes cholesteric liquid crystals that reflect the first color light L1, the first color light L1 that has passed through the second color conversion region 122 but has not been converted can be reflected back by the second cholesteric liquid crystal region 132 into the second color conversion region 122, thereby exciting the color conversion material in the second color conversion region 122 and converting it into the third color light L3. This reduces leakage of the first color light L1 from the third sub-pixel region CC, resulting in a relatively high color purity of the third color light L3 emitted from the third sub-pixel region CC, thereby improving the color purity of the display panel 1000. This also prevents the leakage of the first color light L1 from entering adjacent sub-pixels and causing crosstalk, thereby widening the color gamut. Furthermore, it improves the light extraction efficiency of the second color conversion region 122 in the color conversion layer 120, thereby enhancing the external quantum efficiency of the color conversion layer 120.

[0083] Illustratively, the thickness of the second color conversion portion 122 can be 8 μm to 12 μm. For example, the thickness of the second color conversion portion 122 can be 8 μm, 9 μm, 10.5 μm, 11 μm, or 12 μm. Furthermore, the thickness of the second color conversion portion 122 can be the same as or different from the thickness of the first color conversion portion 121.

[0084] In some examples, the second cholesteric liquid crystal portion 132 and the first cholesteric liquid crystal portion 131 may be arranged along the first direction X; and the thickness H2 of the second cholesteric liquid crystal portion 132 may be the same as or different from the thickness H1 of the first cholesteric liquid crystal portion 131 .

[0085] Exemplarily, as shown in FIG. 1 , the first direction X is perpendicular to the thickness direction Y of the substrate 110 .

[0086] In some embodiments, the material of the second color conversion portion 122 includes a second quantum dot material.

[0087] As can be appreciated, quantum dot materials offer advantages such as high brightness, high color volume, and high efficiency. When the second color conversion portion 122 comprises a second quantum dot material, the second quantum dot material can be excited by the first color light L1 to emit a third color light L3. Furthermore, the emitted third color light L3 has a relatively high brightness, thereby enhancing the display quality of the display panel 1000.

[0088] Exemplarily, the second quantum dot material may be CdSe, CdSe / ZnS, InP, CuInS2 (abbreviated as CIS), AgInS2 (abbreviated as AIS), AgGaS2 (abbreviated as AGS) or a perovskite-based quantum dot material.

[0089] For example, the peak wavelength of the photoluminescence spectrum of the second quantum dot material can be in the range of 525 nm to 540 nm. For example, the peak wavelength of the photoluminescence spectrum of the second quantum dot material can be 525 nm, 530 nm, 535 nm, or 540 nm. In this case, the light emitted by the second quantum dot material (i.e., the third color light L3) is green light.

[0090] For example, the full width at half maximum (FWHM) of the photoluminescence spectrum of the second quantum dot material can be in the range of 15 nm to 35 nm. For example, the full width at half maximum (FWHM) of the photoluminescence spectrum of the second quantum dot material can be 15 nm, 22 nm, 25 nm, 31 nm, or 35 nm. In this way, the color purity of the third color light L3 converted by the second quantum dot material can be improved.

[0091] For example, the color coordinates CIEx of the light emitted by the second quantum dot material may be in the range of 0.170 to 0.230; for example, the color coordinates CIEx of the light emitted by the second quantum dot material may be 0.170, 0.180, 0.190, 0.200, 0.205, 0.210, 0.220, or 0.230. In this case, the light emitted by the second quantum dot material (i.e., the third color light L3) is green light.

[0092] In some examples, the material of the second color conversion portion 122 also includes a second light-transmitting main material, such as a light-transmitting adhesive, in which the second quantum dot material is dispersed. Furthermore, the doping amount of the second quantum dot material is between 20 wt% and 50 wt%. For example, the doping amount of the second quantum dot material can be 20 wt%, 33 wt%, 40 wt%, or 50 wt%.

[0093] In the related art, cholesteric liquid crystals have two zero-field stable states, one of which is a planar state, also known as a planar textured state. Under the action of a zero electric field, the cholesteric liquid crystal in the planar state has a periodic helical structure, with its helical axis substantially perpendicular to the surface of the substrate (e.g., substrate 110). Planar cholesteric liquid crystals have excellent reflective properties and can reflect light within a set wavelength band. Therefore, planar cholesteric liquid crystals can exhibit the performance of a distributed Bragg reflector (DBR).

[0094] In some embodiments, as shown in FIG. 3 , the cholesteric liquid crystal in the first cholesteric liquid crystal portion 131 is in a planar state.

[0095] It is understood that when the cholesteric liquid crystal in the first cholesteric liquid crystal region 131 is in a planar state, it can undergo Bragg reflection and exhibit excellent reflective properties. Furthermore, by adjusting the pitch of the cholesteric liquid crystal in the first cholesteric liquid crystal region 131, the first cholesteric liquid crystal region 131 can be made to reflect the first color light L1. In this manner, the first color light L1 that has passed through the first color conversion region 121 but has not been converted can be reflected back by the first cholesteric liquid crystal region 131 back to the first color conversion region 121, where it excites the color conversion material in the first color conversion region 121 and is converted into the second color light L2. This reduces leakage of the first color light L1 from the second sub-pixel region BB, resulting in a relatively high color purity of the second color light L2 emitted from the second sub-pixel region BB. Furthermore, this prevents the leakage of the first color light L1 from entering adjacent sub-pixels and causing crosstalk, thereby widening the color gamut and improving the light extraction efficiency of the first color conversion region 121 in the color conversion layer 120.

[0096] In some embodiments, as shown in FIG. 3 , the cholesteric liquid crystal in the second cholesteric liquid crystal portion 132 is in a planar state.

[0097] It is understood that when the cholesteric liquid crystal in the second cholesteric liquid crystal region 132 is in a planar state, the second cholesteric liquid crystal region 132 can undergo Bragg reflection and exhibit excellent reflective properties. Furthermore, by adjusting the pitch of the cholesteric liquid crystal in the second cholesteric liquid crystal region 132, the second cholesteric liquid crystal region 132 can be made to reflect the first color light L1. In this manner, the first color light L1 that passes through the second color conversion region 122 but is not converted can be reflected back by the second cholesteric liquid crystal region 132 into the second color conversion region 122, where it excites the color conversion material in the second color conversion region 122 and is converted into the third color light L3. This can reduce leakage of the first color light L1 from the third sub-pixel region CC, resulting in a relatively high color purity of the third color light L3 emitted from the third sub-pixel region CC. Furthermore, this can prevent the leakage of the first color light L1 from entering adjacent sub-pixels and causing crosstalk, thereby widening the color gamut and improving the light extraction efficiency of the second color conversion region 122 in the color conversion layer 120.

[0098] In some implementations, due to the isotropic emission characteristics of the color conversion material (e.g., quantum dot material), the second color light and the third color light converted by the color conversion layer have a relatively wide angular distribution. The angular distribution of the unconverted first color light is determined by the optical properties of the light-emitting substrate. When the light-emitting substrate is an organic light emitting diode (OLED) light-emitting substrate, for example, the emitted first color light has a relatively high concentration of light near the normal viewing angle, resulting in a relatively narrow angular distribution of the first color light L1. This results in a mismatch in the angular distribution of the light emitted from the first, second, and third sub-pixel regions, causing angular color shift.

[0099] In some embodiments, as shown in Figures 1 and 2, the color conversion substrate 100 further includes a light-transmitting portion 140 arranged along a first direction X with the color conversion layer 120. The first direction X intersects the thickness direction of the substrate 110, and the first color light L1 passes through the light-transmitting portion 140. The cholesteric liquid crystal layer 130 further includes a third cholesteric liquid crystal portion 133 located between the substrate 110 and the light-transmitting portion 140. The third cholesteric liquid crystal portion 133 is configured to disperse the portion of the first color light L1 passing through the light-transmitting portion 140 that is close to the normal viewing angle toward a wide viewing angle.

[0100] The light-transmitting portion 140 and the color-converting portion are arranged along the first direction X. For example, as shown in FIG1 , the light-transmitting portion 140 can be substantially flush with the color-converting portion in the first direction X. This allows the surface of the color-converting substrate 100 to be relatively flat. Furthermore, the light-transmitting portion 140 can be located directly opposite the first sub-pixel area AA. In this manner, the first color light L1 can pass through the light-transmitting portion 140 and be emitted from the first sub-pixel area AA.

[0101] For example, the material of the light-transmitting portion 140 may be transparent photoresist.

[0102] For example, the thickness of the light-transmitting portion 140 may be 8 μm to 12 μm, for example, 8 μm, 9 μm, 10.2 μm, 11.2 μm, or 12 μm. Moreover, the thickness of the light-transmitting portion 140 may be the same as or different from the thickness of the color conversion layer 120 .

[0103] It can be understood that when the third cholesteric liquid crystal portion 133 is disposed between the substrate 110 and the light-transmitting portion 140, and the third cholesteric liquid crystal portion 133 disperses the portion of the first color light L1 close to the normal viewing angle toward the wide viewing angle, compared to a case where the third cholesteric liquid crystal portion 133 is not disposed, the angular distribution of the first color light L1 emitted from the first sub-pixel region AA is relatively wider. In this way, the matching of the angular distributions of the light emitted from the first sub-pixel region AA, the second sub-pixel region BB, and the third sub-pixel region CC can be improved, thereby alleviating the problem of angular color shift.

[0104] In related art, the second zero-field stable state of cholesteric liquid crystal is the focal conic state, also known as the focal conic texture state. Cholesteric liquid crystal in the focal conic state exhibits multi-domain formation, with the helical structure within each domain still present. Therefore, cholesteric liquid crystal in the focal conic state scatters incident light. Furthermore, the focal conic state of cholesteric liquid crystal is independent of the polarization properties of the incident light.

[0105] In some embodiments, as shown in FIG. 4 , the cholesteric liquid crystal in the third cholesteric liquid crystal portion 133 is in a focal conic state.

[0106] It can be understood that when the cholesteric liquid crystal in the third cholesteric liquid crystal portion 133 is in a focal conic state, it is equivalent to adding scattering particles to the third cholesteric liquid crystal portion 133, allowing the third cholesteric liquid crystal portion 133 to scatter the first color light L1, thereby shaping the emission spectrum of the first color light L1. This can ensure a relatively wide angular distribution of the first color light L1 emitted from the first sub-pixel region AA, improve the matching of the angular distributions of the light emitted from the first sub-pixel region AA, the second sub-pixel region BB, and the third sub-pixel region CC, and alleviate the problem of angular color shift.

[0107] The following explains the helical orientation of liquid crystal molecules in cholesteric liquid crystals and the concept of pitch. In related art, the helical structure of cholesteric liquid crystals is either left-handed or right-handed. Cholesteric liquid crystals can be divided into left-handed and right-handed cholesteric liquid crystals based on the handedness of the helical structure. Cholesteric liquid crystals consist of many layers of molecules, each arranged in the same direction, but with the directions of the molecules in adjacent layers slightly rotated, forming a helical structure. When the molecular arrangement rotates 360 degrees and then returns to its original orientation, the distance between two layers with identical molecular arrangements is called the cholesteric liquid crystal pitch. The pitch can be altered by adding chiral agents to the cholesteric liquid crystals as needed. If the wavelength of the incident light matches the helical pitch of the cholesteric liquid crystal, the cholesteric liquid crystal allows light with an opposite handedness to pass through and reflects light with the same handedness. If the wavelength of the incident light does not match the helical pitch of the cholesteric liquid crystal, the cholesteric liquid crystal allows all incident light to pass through. Therefore, the reflection or transmission of incident light can be adjusted by adjusting the helical pitch.

[0108] 5 , the first cholesteric liquid crystal portion 131 includes a stacked first chiral liquid crystal portion 1311 and a second chiral liquid crystal portion 1312. The helical direction of the liquid crystal molecules in the first chiral liquid crystal portion 1311 is opposite to the helical direction of the liquid crystal molecules in the second chiral liquid crystal portion 1312.

[0109] It can be understood that because the first cholesteric liquid crystal portion 131 can reflect the first color light L1, the helical pitch of the cholesteric liquid crystal in the first cholesteric liquid crystal portion 131 is consistent with the wavelength of the first color light L1. In other words, the helical pitches of the first chiral liquid crystal portion 1311 and the second chiral liquid crystal portion 1312 are consistent with the wavelength of the first color light L1. As shown in FIG5 , the portion L11 of the first color light L1 whose helical direction is the same as the helical direction of the liquid crystal molecules in the first chiral liquid crystal portion 1311 can be reflected by the first chiral liquid crystal portion 1311 back to the first color conversion portion 121 and converted into the second color light L2. At the same time, because the helical direction of the liquid crystal molecules in the first chiral liquid crystal portion 1311 is opposite to that of the liquid crystal molecules in the second chiral liquid crystal portion 1312, the portion L12 of the first color light L1 whose helical direction is opposite to that of the liquid crystal molecules in the first chiral liquid crystal portion 1311 can be reflected by the second chiral liquid crystal portion 1312 back to the first color conversion portion 121 and converted into the second color light L2. In this way, the reflectivity of the first cholesteric liquid crystal portion 131 to the first color light L1 can be enhanced, so that relatively less first color light L1 leaks from the second sub-pixel region BB, and the color purity of the second color light L2 emitted from the second sub-pixel region BB is relatively high. At the same time, the light extraction efficiency of the first color conversion portion 121 in the color conversion layer 120 can be improved.

[0110] In some examples, the helical direction of the liquid crystal molecules in the first chiral liquid crystal portion 1311 is left-handed, and in this case, the helical direction of the liquid crystal molecules in the second chiral liquid crystal portion 1312 is right-handed. In other examples, the helical direction of the liquid crystal molecules in the first chiral liquid crystal portion 1311 is right-handed, and in this case, the helical direction of the liquid crystal molecules in the second chiral liquid crystal portion 1312 is left-handed.

[0111] It should be noted that the portion of the first cholesteric liquid crystal portion 131 close to the first color conversion portion 121 may be the first chiral liquid crystal portion 1311 or the second chiral liquid crystal portion 1312 , which is not limited here.

[0112] In some embodiments, as shown in FIG5 , when the cholesteric liquid crystal layer 130 further includes a second cholesteric liquid crystal portion 132, the second cholesteric liquid crystal portion 132 includes a stacked third chiral liquid crystal portion 1321 and a fourth chiral liquid crystal portion 1322. The helical direction of the liquid crystal molecules in the third chiral liquid crystal portion 1321 is opposite to the helical direction of the liquid crystal molecules in the fourth chiral liquid crystal portion 1322.

[0113] It can be understood that because the second cholesteric liquid crystal portion 132 can reflect the first color light L1, the helical pitch of the cholesteric liquid crystal in the second cholesteric liquid crystal portion 132 is consistent with the wavelength of the first color light L1. In other words, the helical pitch of the third chiral liquid crystal portion 1321 and the fourth chiral liquid crystal portion 1322 is consistent with the wavelength of the first color light L1. As a result, as shown in FIG5 , the portion L11 of the first color light L1 having the same helical direction as the liquid crystal molecules in the third chiral liquid crystal portion 1321 can be reflected by the third chiral liquid crystal portion 1321 back to the first color conversion portion 121 and converted into the third color light L3. At the same time, because the helical direction of the liquid crystal molecules in the third chiral liquid crystal portion 1321 is opposite to that of the liquid crystal molecules in the fourth chiral liquid crystal portion 1322, the portion L12 of the first color light L1 having the opposite helical direction as that of the liquid crystal molecules in the third chiral liquid crystal portion 1321 can be reflected by the fourth chiral liquid crystal portion 1322 back to the second color conversion portion 122 and converted into the third color light L3. In this way, the reflectivity of the second cholesteric liquid crystal portion 132 to the first color light L1 can be enhanced, so that relatively less first color light L1 leaks from the third sub-pixel region CC, and the color purity of the third color light L3 emitted from the third sub-pixel region CC is relatively high. At the same time, the light extraction efficiency of the second color conversion portion 122 in the color conversion layer 120 can be improved.

[0114] In some examples, the helical direction of the liquid crystal molecules in the third chiral liquid crystal portion 1321 is left-handed, and in this case, the helical direction of the liquid crystal molecules in the fourth chiral liquid crystal portion 1322 is right-handed. In other examples, the helical direction of the liquid crystal molecules in the third chiral liquid crystal portion 1321 is right-handed, and in this case, the helical direction of the liquid crystal molecules in the fourth chiral liquid crystal portion 1322 is left-handed.

[0115] It should be noted that the portion of the second cholesteric liquid crystal portion 132 close to the second color conversion portion 122 may be the third chiral liquid crystal portion 1321 or the fourth chiral liquid crystal portion 1322 , which is not limited here.

[0116] In some embodiments, the helical pitch of the liquid crystal molecules in the first cholesteric liquid crystal portion 131 is greater than or equal to 270 nm and less than or equal to 310 nm.

[0117] It is understood that when the helical pitch of the liquid crystal molecules in the first cholesteric liquid crystal portion 131 is within the range of 270 nm to 310 nm, the wavelength of light reflected by the first cholesteric liquid crystal portion 131 matches the wavelength of blue light. Thus, the first cholesteric liquid crystal portion 131 can reflect blue light leaking from the second sub-pixel region BB back to the first color conversion portion 121, where it is converted into second color light L2 (e.g., red light) by the second color conversion portion 122. This results in a relatively high color purity of the second color light L2 emitted from the second sub-pixel region BB. Furthermore, the light extraction efficiency of the first color conversion portion 121 in the color conversion layer 120 can be improved.

[0118] For example, the helical pitch of the liquid crystal molecules in the first cholesteric liquid crystal portion 131 may be 270 nm, 280 nm, 290 nm, 300 nm, or 310 nm.

[0119] In some embodiments, the helical pitch of the liquid crystal molecules in the second cholesteric liquid crystal portion 132 is greater than or equal to 270 nm and less than or equal to 310 nm.

[0120] It is understood that when the helical pitch of the liquid crystal molecules in the second cholesteric liquid crystal portion 132 is within the range of 270 nm to 310 nm, the wavelength of light reflected by the second cholesteric liquid crystal portion 132 matches the wavelength of blue light. In this way, the second cholesteric liquid crystal portion 132 can reflect the blue light leaking from the third sub-pixel region CC back to the second color conversion portion 122, where it is converted into the third color light L3 (e.g., green light) by the second color conversion portion 122. This ensures that the color purity of the third color light L3 emitted from the third sub-pixel region CC is relatively high. At the same time, the light extraction efficiency of the second color conversion portion 122 in the color conversion layer 120 can be improved.

[0121] For example, the helical pitch of the liquid crystal molecules in the second cholesteric liquid crystal portion 132 may be 270 nm, 278 nm, 291 nm, 300 nm, or 310 nm.

[0122] In some embodiments, the first color light L1 is blue light. The central reflection wavelength of the first cholesteric liquid crystal portion 131 is greater than or equal to 450 nm and less than or equal to 470 nm.

[0123] It can be understood that when the central reflection wavelength of the first cholesteric liquid crystal portion 131 is within the range of 450 nm to 470 nm, the wavelength corresponding to the trough of the transmission spectrum of the first cholesteric liquid crystal portion 131 is also within the range of 450 nm to 470 nm. In other words, the first cholesteric liquid crystal portion 131 can reflect light with a wavelength within the range of 450 nm to 470 nm. In this way, the first cholesteric liquid crystal portion 131 can reflect blue light leaking from the second sub-pixel region BB back to the first color conversion portion 121, where it is converted into second color light L2 (e.g., red light) by the second color conversion portion 122. This improves the color purity of the second color light L2 emitted from the second sub-pixel region BB and enhances the light extraction efficiency of the first color conversion portion 121 in the color conversion layer 120.

[0124] For example, the central reflection wavelength of the first cholesteric liquid crystal portion 131 may be 450 nm, 455 nm, 460 nm, 465 nm, or 470 nm.

[0125] In some embodiments, the first color light L1 is blue light. The central reflection wavelength of the second cholesteric liquid crystal portion 132 is greater than or equal to 450 nm and less than or equal to 470 nm.

[0126] It can be understood that when the central reflection wavelength of the second cholesteric liquid crystal portion 132 is within the range of 450 nm to 470 nm, the wavelength corresponding to the trough of the transmission spectrum of the second cholesteric liquid crystal portion 132 is also within the range of 450 nm to 470 nm. In other words, the second cholesteric liquid crystal portion 132 reflects light with a wavelength within the range of 450 nm to 470 nm. In this way, the second cholesteric liquid crystal portion 132 can reflect blue light leaking from the third sub-pixel region CC back to the second color conversion portion 122, where it is converted into third color light L3 (e.g., green light). This results in a relatively high color purity of the third color light L3 emitted from the third sub-pixel region CC. This also improves the light extraction efficiency of the second color conversion portion 122 in the color conversion layer 120.

[0127] For example, the central reflection wavelength of the second cholesteric liquid crystal portion 132 may be 450 nm, 454 nm, 460 nm, 466 nm, or 470 nm.

[0128] In some embodiments, the half-value width of the transmission spectrum of the first cholesteric liquid crystal portion 131 is greater than or equal to 70 nm and less than or equal to 100 nm.

[0129] It is understandable that when the half-maximum width of the transmission spectrum of the first cholesteric liquid crystal portion 131 is within the range of 70 nm to 100 nm, the trough peak of the transmission spectrum of the first cholesteric liquid crystal portion 131 is relatively narrow. In this way, the first cholesteric liquid crystal portion 131 can specifically reflect the first color light L1 (for example, blue light) and reflect relatively less light of other wavelength bands or other colors. In this way, the loss of light of other wavelength bands or other colors during multiple reflections can be avoided, thereby improving the light extraction efficiency of the first color conversion portion 121 in the color conversion layer 120.

[0130] For example, the half-value width of the transmission spectrum of the first cholesteric liquid crystal portion 131 may be 70 nm, 80 nm, 90 nm, or 100 nm.

[0131] In some embodiments, the half-value width of the transmission spectrum of the second cholesteric liquid crystal portion 132 is greater than or equal to 70 nm and less than or equal to 100 nm.

[0132] It is understandable that when the half-maximum width of the transmission spectrum of the second cholesteric liquid crystal portion 132 is within the range of 70 nm to 100 nm, the trough peak of the transmission spectrum of the second cholesteric liquid crystal portion 132 is relatively narrow. In this way, the second cholesteric liquid crystal portion 132 can specifically reflect the first color light L1 (for example, blue light) and reflect relatively less light of other wavelength bands or other colors. In this way, the loss of light of other wavelength bands or other colors during multiple reflections can be avoided, thereby improving the light extraction efficiency of the second color conversion portion 122 in the color conversion layer 120.

[0133] For example, the half-value width of the transmission spectrum of the second cholesteric liquid crystal portion 132 may be 70 nm, 85 nm, 95 nm, or 100 nm.

[0134] In some embodiments, as shown in FIG6 , the color conversion substrate 100 further includes an alignment layer 150 positioned between the cholesteric liquid crystal layer 130 and the substrate 110. The alignment layer 150 includes a first alignment portion 151, a second alignment portion 152, and a third alignment portion 153 arranged along a first direction X. The first alignment portion 151 is configured to align the liquid crystal molecules in the first cholesteric liquid crystal portion 131. The second alignment portion 152 is configured to align the liquid crystal molecules in the second cholesteric liquid crystal portion 132. The third alignment portion 153 is configured to align the liquid crystal molecules in the third cholesteric liquid crystal portion 133.

[0135] By arranging an alignment layer 150 between the cholesteric liquid crystal layer 130 and the substrate 110, and making the molecules of the alignment layer 150 parallel to the substrate 110, the first alignment portion 151 can be used to make the initial alignment of the liquid crystal molecules in the first cholesteric liquid crystal portion 131 parallel to the substrate 110, thereby achieving the purpose of aligning the liquid crystal molecules in the first cholesteric liquid crystal portion 131; the second alignment portion 152 can be used to make the initial alignment of the liquid crystal molecules in the second cholesteric liquid crystal portion 132 parallel to the substrate 110, thereby achieving the purpose of aligning the liquid crystal molecules in the second cholesteric liquid crystal portion 132. The purpose of aligning the liquid crystal molecules is to use the third alignment portion 153 to initially align the liquid crystal molecules in the third cholesteric liquid crystal portion 133 parallel to the substrate 110. This allows the long axes of the liquid crystal molecules in the first initial cholesteric liquid crystal portion 131a, the second initial cholesteric liquid crystal portion 132a, and the third initial cholesteric liquid crystal portion 133a to be aligned parallel to the substrate 110, forming a cholesteric liquid crystal structure. This alignment principle can be either photoalignment or rubbing alignment, and is not limited here. For an introduction to the first initial cholesteric liquid crystal portion 131a, the second initial cholesteric liquid crystal portion 132a, and the third initial cholesteric liquid crystal portion 133a, please refer to S2.1 below in the method for preparing the color conversion substrate 100 and will not be further elaborated here.

[0136] For example, the material of the alignment layer 150 may be an alignment agent, such as polyimide.

[0137] It should be noted that, when the first cholesteric liquid crystal portion 131 includes a first chiral liquid crystal portion 1311 and a second chiral liquid crystal portion 1312, the first alignment portion 151 can align the liquid crystal molecules in the portion of the first or second chiral liquid crystal portion 1311, 1312 that is closer to the substrate 110. When the second cholesteric liquid crystal portion 132 includes a third chiral liquid crystal portion 1321 and a fourth chiral liquid crystal portion 1322, the second alignment portion 152 can align the liquid crystal molecules in the portion of the third or fourth chiral liquid crystal portion 1321, 1322 that is closer to the substrate 110.

[0138] The above is an exemplary description of the first cholesteric liquid crystal portion 131 , the second cholesteric liquid crystal portion 132 , and the alignment layer 150 . The third cholesteric liquid crystal portion 133 will be described below in an exemplary manner.

[0139] In the related art, haze is the percentage of the transmitted light intensity that deviates from the incident light by more than 2.5° to the total transmitted light intensity. The greater the haze, the lower the gloss and transparency of the film, especially the imaging quality.

[0140] In some embodiments, the haze of the third cholesteric liquid crystal portion 133 is greater than or equal to 3% and less than or equal to 8%.

[0141] It is understandable that when the haze of the third cholesteric liquid crystal portion 133 is in the range of 3% to 8%, the front light extraction efficiency of the third cholesteric liquid crystal portion 133 is relatively high. Moreover, compared with the first color light L1 incident on the third cholesteric liquid crystal portion 133, the first color light L1 passing through the third cholesteric liquid crystal portion 133 has a relatively wide angular distribution. In this way, the matching of the angular distributions of the light emitted from the first sub-pixel area AA, the second sub-pixel area BB, and the third sub-pixel area CC can be improved, thereby alleviating the problem of angular color shift.

[0142] For example, the haze of the third cholesteric liquid crystal portion 133 may be 3%, 4%, 5%, 6%, 7% or 8%.

[0143] In some embodiments, the third cholesteric liquid crystal portion 133 has a transmittance greater than or equal to 90% for light in the first wavelength band, wherein the minimum wavelength of the first wavelength band is 450 nm and the maximum wavelength of the first wavelength band is 470 nm.

[0144] It can be understood that when the minimum wavelength of the first wavelength band is 450 nm and the maximum wavelength of the first wavelength band is 470 nm, the light in the first wavelength band matches the blue light. When the transmittance of the third cholesteric liquid crystal portion 133 for the light in the first wavelength band is greater than or equal to 90%, the transmittance of the third cholesteric liquid crystal portion 133 for the blue light is relatively high. This improves the light extraction efficiency of the third cholesteric liquid crystal portion 133 and the color extraction efficiency of the color conversion substrate 100.

[0145] For example, the transmittance of the third cholesteric liquid crystal portion 133 to the light in the first wavelength band may be 90%, 92%, 94%, 96%, 98%, 99% or 100%.

[0146] In some embodiments, as shown in FIG. 2 , the thickness H of the cholesteric liquid crystal layer 130 is greater than or equal to 2 μm and less than or equal to 6 μm.

[0147] It can be understood that when the thickness H of the cholesteric liquid crystal layer 130 is in the range of 2μm to 6μm, on the one hand, the first cholesteric liquid crystal portion 131 and the second cholesteric liquid crystal portion 132 can have a certain thickness to achieve the function of reflecting the first color light L1. On the other hand, it can prevent the cholesteric liquid crystal layer 130 from absorbing more incident light; specifically, when the thickness H1 of the first cholesteric liquid crystal portion 131 is in the range of 2μm to 6μm, it can prevent the first cholesteric liquid crystal portion 131 from absorbing more light passing through the first color conversion portion 121, such as the second color light L2 generated by conversion, and / or the first color light L1 that has not been converted; when the thickness H2 of the second cholesteric liquid crystal portion 132 is in the range of 2μm to 6μm, it can prevent the second cholesteric liquid crystal portion 131 from absorbing more light passing through the first color conversion portion 121; The second cholesteric liquid crystal layer 132 absorbs a significant portion of light transmitted through the second color conversion portion 122, such as the converted third color light L3 and / or the unconverted first color light L1. When the thickness H2 of the second cholesteric liquid crystal layer 132 is within a range of 2 μm to 6 μm, the third cholesteric liquid crystal layer 133 can be prevented from absorbing a significant portion of light transmitted through the light-transmitting portion 140 (i.e., the first color light L1). This can improve the color extraction efficiency of the color conversion substrate 100 and the efficiency of the display panel 1000. Thirdly, since a greater thickness H of the cholesteric liquid crystal layer 130 results in a correspondingly higher haze, when the thickness H of the cholesteric liquid crystal layer 130 is within a range of 2 μm to 6 μm, the haze of the cholesteric liquid crystal layer 130 can be prevented from being relatively high, allowing the display panel 1000 to achieve a better display quality.

[0148] For example, the thickness H1 of the first cholesteric liquid crystal portion 131 may be 2 μm, 3 μm, 4 μm, 5 μm, or 6 μm.

[0149] For example, when the first cholesteric liquid crystal portion 131 includes a stacked first chiral liquid crystal portion 1311 and a second chiral liquid crystal portion 1312, the thickness of the first chiral liquid crystal portion 1311 is greater than or equal to 1 μm and less than or equal to 3 μm, such as 1 μm, 1.3 μm, 2 μm, 2.7 μm, or 3 μm, and the thickness of the second chiral liquid crystal portion 1312 is greater than or equal to 1 μm and less than or equal to 3 μm, such as 1 μm, 1.4 μm, 2 μm, 2.5 μm, or 3 μm. Furthermore, the thickness of the first chiral liquid crystal portion 1311 and the thickness of the second chiral liquid crystal portion 1312 may be the same or different.

[0150] For example, the thickness H2 of the second cholesteric liquid crystal portion 132 may be 2 μm, 3.2 μm, 4 μm, 5.3 μm, or 6 μm.

[0151] For example, when the second cholesteric liquid crystal portion 132 includes a stacked third chiral liquid crystal portion 1321 and a fourth chiral liquid crystal portion 1322, the thickness of the third chiral liquid crystal portion 1321 is greater than or equal to 1 μm and less than or equal to 3 μm, such as 1 μm, 1.5 μm, 2 μm, 2.5 μm, or 3 μm. The thickness of the fourth chiral liquid crystal portion 1322 is greater than or equal to 1 μm and less than or equal to 3 μm, such as 1 μm, 1.6 μm, 2 μm, 2.4 μm, or 3 μm. Furthermore, the thickness of the third chiral liquid crystal portion 1321 and the fourth chiral liquid crystal portion 1322 may be the same or different.

[0152] For example, the thickness H3 of the third cholesteric liquid crystal portion 133 may be 2 μm, 3 μm, 4.5 μm, 5 μm, or 6 μm.

[0153] It should be noted that the thicknesses of any two of the first cholesteric liquid crystal portion 131 , the second cholesteric liquid crystal portion 132 and the third cholesteric liquid crystal portion 133 may be the same or different, and there is no limitation thereto.

[0154] In some examples, the thickness H3 of the first cholesteric liquid crystal portion 131 , the second cholesteric liquid crystal portion 132 , and the third cholesteric liquid crystal portion 133 are the same. In this way, the first cholesteric liquid crystal portion 131 , the second cholesteric liquid crystal portion 132 , and the third cholesteric liquid crystal portion 133 can be prepared by a single coating process, which can simplify the process.

[0155] In some embodiments, as shown in FIG1 and FIG6 , the color conversion substrate 100 further includes a barrier pattern 160. The barrier pattern 160 includes a plurality of first openings Q. The first color conversion portion 121 and the first cholesteric liquid crystal portion 131 are located within one first opening Q. The second color conversion portion 122 and the second cholesteric liquid crystal portion 132 are located within another first opening Q. The light-transmitting portion 140 and the third cholesteric liquid crystal portion 133 are located within yet another first opening Q.

[0156] It is understood that the blocking pattern 160 can separate the first sub-pixel area AA, the second sub-pixel area BB, and the third sub-pixel area CC. First, it can absorb wide-angle light emitted from the first sub-pixel area AA, the second sub-pixel area BB, and the third sub-pixel area CC, thereby improving cross-color between adjacent sub-pixel areas. Second, it can separate the first color conversion portion 121 and the second color conversion portion 122 from each other during manufacturing, improving the feasibility of the process. Third, it facilitates the formation of a thicker color conversion layer 120 and cholesteric liquid crystal layer 130. Specifically, a thicker color conversion layer 120 can improve the conversion efficiency of the color conversion layer 120 for the first color light L1. A thicker cholesteric liquid crystal layer 130 can also enhance the reflection effect of the first cholesteric liquid crystal portion 131 and the second cholesteric liquid crystal portion 132 on the first color light L1, as well as the scattering effect of the third cholesteric liquid crystal portion 133 on the first color light L1.

[0157] In some examples, as shown in Figures 1 and 6, the cross-section of the portion of the blocking pattern 160 located between two adjacent sub-pixel regions has a shape of an inverted trapezoid, with one end being larger than the other, and the smaller end being further away from the substrate 110 than the larger end. This allows more light emitted by the light-emitting substrate 200 to enter the first sub-pixel region AA, the second sub-pixel region BB, and the third sub-pixel region CC.

[0158] For example, the thickness of the barrier pattern 160 in the second direction Y may be 5 μm, 10 μm, 15 μm, 18 μm, or 20 μm, etc., where the second direction Y is the thickness direction of the substrate 110 .

[0159] For example, the material of the barrier pattern 160 may be an acrylic polymer material or an epoxy polymer material.

[0160] In some embodiments, as shown in Figures 1 and 6, the color conversion substrate 100 further includes a light-blocking layer 170 positioned between the cholesteric liquid crystal layer 130 and the substrate. The light-blocking layer 170 includes a light-absorbing pattern 171 and multiple color filter sections 172. The light-absorbing pattern 171 includes multiple second openings N, which are positioned opposite the multiple first openings Q. Multiple color filter sections 172 are positioned on the side of the substrate proximal to the cholesteric liquid crystal layer 130; each color filter section 172 is disposed within a second opening N. The multiple color filter sections 172 include a first color filter section 1721 that faces the first color conversion section 121, a second color filter section 1722 that faces the second color conversion section 122, and a third color filter section 1723 that faces the light-transmitting section 140.

[0161] The light-blocking layer 170 includes the light-absorbing pattern 171, thereby separating different color filter portions 172 and absorbing light incident on the light-absorbing pattern 171, thereby improving the display contrast of the display panel 1000. By arranging the plurality of second openings N opposite the plurality of first openings Q, the first openings Q and the second openings N can collectively form a sub-pixel region, such as a first sub-pixel region AA, a second sub-pixel region BB, or a third sub-pixel region CC.

[0162] For example, the thickness of the light absorption pattern 171 in the second direction Y may be 2 μm, 3 μm, 4 μm, 5 μm, or 6 μm.

[0163] For example, the material of the light absorption pattern 171 may be a mixed material of metal, metal oxide and resin, the metal being, for example, chromium, and the metal oxide being, for example, chromium oxide.

[0164] The color filter portion 172 can be configured to allow light of the same color to pass through and filter out light of a different color. The first color filter portion 1721 allows the second color light L2 in the external light to enter the second sub-pixel region BB and be reflected before being emitted, thereby enhancing the light effect. Furthermore, the color filter portion 1721 filters out all light except the second color light L2, thereby improving the color purity of the light emitted from the second sub-pixel region BB and achieving a wider color gamut for the display panel 1000.

[0165] For example, when the second color light L2 is red light, the material of the first color filter portion 1721 may include a photoresist resin, and a red dye or a red pigment dispersed in the photoresist resin.

[0166] Illustratively, the transmittance of the first color filter portion 1721 to red light is greater than or equal to 80%, for example, 80%, 85%, 90% or 99%.

[0167] Exemplarily, the thickness of the first color filter portion 1721 may be 1 μm to 3 μm, for example, 1 μm, 1.5 μm, 2 μm, 2.5 μm, or 3 μm.

[0168] By providing the second color film portion 1722, the third color light L3 in the external light can enter the third sub-pixel area CC and be emitted after reflection, thereby increasing the light effect. At the same time, other light in the external light except the third color light L3 can be filtered out to improve the color purity of the light emitted from the third sub-pixel area CC, thereby making the color gamut of the display panel 1000 higher.

[0169] For example, when the third color light L3 is green light, the material of the second color filter portion 1722 may include a photoresist resin, and a green dye or a green pigment dispersed in the photoresist resin.

[0170] Illustratively, the transmittance of the second color filter portion 1722 to green light is greater than or equal to 75%, such as 75%, 80%, 90% or 99%.

[0171] Exemplarily, the thickness of the second color filter portion 1722 may be 1 μm to 3 μm, such as 1 μm, 1.6 μm, 2 μm, 2.4 μm, or 3 μm.

[0172] By setting the third color film portion 1723, the first color light L1 in the external light can enter the first sub-pixel area AA and be emitted after reflection, thereby increasing the light effect. At the same time, other light in the external light except the first color light L1 can be filtered out to improve the color purity of the light emitted from the first sub-pixel area AA, thereby making the color gamut of the display panel 1000 higher.

[0173] For example, when the first color light L1 is blue light, the material of the third color filter portion 1723 may include a photoresist resin, and a blue dye or a blue pigment dispersed in the photoresist resin.

[0174] Illustratively, the transmittance of the third color filter portion 1723 to blue light is greater than or equal to 70%, for example, 70%, 80%, 90% or 98%.

[0175] Exemplarily, the thickness of the third color filter portion 1723 may be 1 μm to 3 μm, for example, 1 μm, 1.4 μm, 2 μm, 2.6 μm, or 3 μm.

[0176] In some embodiments, as shown in Figures 1 and 6 , color conversion substrate 100 further includes a first encapsulation layer 180. First encapsulation layer 180 is located on a side of first color conversion portion 121, second color conversion portion 122, and light-transmitting portion 140 that is away from substrate 110. If color conversion substrate 100 further includes a blocking pattern 160, first encapsulation layer 180 is also located on a side of blocking pattern 160 that is away from substrate 110.

[0177] With this arrangement, the first encapsulation layer 180 can be used to cover the first color conversion portion 121, the second color conversion portion 122, the light-transmitting portion 140, and the blocking pattern 160, thereby encapsulating the first color conversion portion 121 and the second color conversion portion 122. This prevents moisture and oxygen from the external environment from entering the color conversion substrate 100 and damaging the material of the first color conversion portion 121 (e.g., red quantum dot material) and the material of the second color conversion portion 122 (e.g., green quantum dot material), thereby shortening the life of the color conversion substrate 100.

[0178] Exemplarily, the first encapsulation layer 180 may include a plurality of stacked first sub-encapsulation layers, and the material of the first sub-encapsulation layers may be an organic material or an inorganic material. For example, the organic material may be an acrylate polymer material or an epoxy polymer material. For example, the inorganic material may be SiOx, SiNx, or Al2O3.

[0179] Exemplarily, the thickness of the first encapsulation layer 180 may be 10 μm to 30 μm, for example, 10 μm, 15 μm, 20 μm, 25 μm, or 30 μm.

[0180] Some embodiments of the present disclosure further provide a method for preparing a color conversion substrate 100 , as shown in FIG. 7 , including steps S1 to S3 .

[0181] S1: providing a substrate 110 .

[0182] S2 : forming a cholesteric liquid crystal layer 130 on one side of the substrate 110 ; the cholesteric liquid crystal layer 130 includes a first cholesteric liquid crystal portion 131 .

[0183] S3: A color conversion layer 120 is formed on the side of the cholesteric liquid crystal layer 130 away from the substrate 110. The color conversion layer 120 includes a first color conversion portion 121 located on the side of the first cholesteric liquid crystal portion 131 away from the substrate 110. The first color conversion portion 121 is configured to convert the first color light L1 incident on the first color conversion portion 121 into the second color light L2. The first cholesteric liquid crystal portion 131 is configured to reflect the unconverted light in the first color light L1 back to the first color conversion portion 121.

[0184] The beneficial effects that can be achieved by the method for preparing a color conversion substrate 100 provided in some embodiments of the present disclosure are the same as the beneficial effects that can be achieved by the color conversion substrate 100 provided by the above technical solution, and will not be repeated here.

[0185] In some embodiments, a cholesteric liquid crystal layer 130 is formed on one side of the substrate 110 , as shown in FIG. 8 and FIG. 9 , including steps S2.1 to S2.3 .

[0186] S2.1: As shown in FIG9 , an initial cholesteric liquid crystal layer 130a is formed on one side of the substrate 110. The initial cholesteric liquid crystal layer 130a includes a first initial cholesteric liquid crystal portion 131a, a second initial cholesteric liquid crystal portion 132a, and a third initial cholesteric liquid crystal portion 133a.

[0187] Exemplarily, the process of forming the initial cholesteric liquid crystal layer 130 a is a coating process.

[0188] Exemplarily, the material forming the initial cholesteric liquid crystal layer 130a is a precursor, which includes, for example, a liquid crystal monomer, a chiral additive, and a photoinitiator.

[0189] Illustratively, in the precursor, the mass proportion of the liquid crystal monomer may be 85% to 95%, for example, 85%, 88%, 90%, 92% or 95%.

[0190] For example, in the precursor, the mass proportion of the chiral additive may be 2% to 5%, for example, 2%, 3%, 4%, 4.5% or 5%.

[0191] For example, in the precursor, the mass proportion of the photoinitiator may be 1% to 5%, for example, 1%, 2%, 3%, 4% or 5%.

[0192] For example, the liquid crystal monomer may be selected from any one of the structures represented by the following general formula (I).

[0193] Wherein, R1 and R2 are the same or different and are independently selected from polymerizable functional groups, such as acrylate groups, vinyl ether groups, thiol groups or epoxy groups. 21 , L 22 , L 23 L3 and L4 are the same or different and are independently selected from C0-C20 alkyl groups and alkyl groups containing heteroatoms such as N, O, and S to provide a bridging chain. A, B, and C are the same or different and are independently selected from aryl, heteroaryl, and cycloalkane groups; examples of aryl groups include phenyl, naphthyl, and biphenyl. m, n, and p are the same or different and are independently selected from 0, 1, 2, 3, 4, and 5.

[0194] For example, the structure of the liquid crystal monomer may be the structure shown in structural formula (II).

[0195] For example, the structure of the photoinitiator may be the structure shown in structural formula (III).

[0196] It should be noted that the above-listed structural formulas are examples of the structures of liquid crystal monomers and photoinitiators and are not intended to limit the scope of these monomers and photoinitiators. Furthermore, (I), (II), and (III) in the above structural formulas are merely designations of the structures and are not part of the structures themselves.

[0197] S2.2: As shown in FIG. 9 , the first initial cholesteric liquid crystal portion 131 a is formed into the first cholesteric liquid crystal portion 131 , and the second initial cholesteric liquid crystal portion 132 a is formed into the second cholesteric liquid crystal portion 132 .

[0198] In some examples, the first initial cholesteric liquid crystal portion 131 a is formed into the first cholesteric liquid crystal portion 131 , and the second initial cholesteric liquid crystal portion 132 a is formed into the second cholesteric liquid crystal portion 132 , including S2.2.1 to S2.2.3.

[0199] S2.2.1: As shown in FIG9 , a mask is placed above the initial cholesteric liquid crystal layer 130 a to expose the first initial cholesteric liquid crystal portion 131 a and the second initial cholesteric liquid crystal portion 132 a .

[0200] S2.2.2: As shown in FIG. 9 , the first initial cholesteric liquid crystal portion 131 a and the second initial cholesteric liquid crystal portion 132 a are cured by ultraviolet light irradiation to form the first cholesteric liquid crystal portion 131 and the second cholesteric liquid crystal portion 132 .

[0201] By using the above process, the first initial cholesteric liquid crystal portion 131a and the second initial cholesteric liquid crystal portion 132a irradiated with ultraviolet light can undergo a curing reaction to form the first cholesteric liquid crystal portion 131 and the second cholesteric liquid crystal portion 132 containing planar cholesteric liquid crystals. The liquid crystal molecules in the region not irradiated with ultraviolet light (e.g., the third initial cholesteric liquid crystal portion 133a) are still planar cholesteric liquid crystals in a small molecule state and have not undergone a curing reaction.

[0202] For example, the intensity of ultraviolet radiation can be 0.5 mW / cm 2 ~10.0mW / cm 2 , for example 0.5 mW / cm 2 , 2.0mW / cm 2 , 4.0mW / cm 2 、6.0mW / cm 2 , 8.0mW / cm 2 or 10.0mW / cm 2 .

[0203] For example, the ultraviolet light irradiation time can be 2 min to 30 min, for example, 2 min, 10 min, 15 min, 20 min, 25 min or 30 min.

[0204] S2.2.3: Remove the mask.

[0205] S2.3: As shown in FIG. 9 , the third initial cholesteric liquid crystal portion 133 a is formed into the third cholesteric liquid crystal portion 133 .

[0206] In some examples, the third initial cholesteric liquid crystal portion 133 a is formed into the third cholesteric liquid crystal portion 133 including S2.3.1 to S2.3.2.

[0207] S2.3.1: Heat the third initial cholesteric liquid crystal portion 133a so that the temperature of the third initial cholesteric liquid crystal portion 133a is higher than the clearing point of the liquid crystal molecules.

[0208] By using the above process, the helical axis of the cholesteric liquid crystal in the third initial cholesteric liquid crystal portion 133 a can be made isotropic, thereby forming focal conic cholesteric liquid crystal.

[0209] Exemplarily, the third initial cholesteric liquid crystal portion 133a is heated to 120°C to 150°C, such as 120°C, 125°C, 130°C, 135°C, 140°C, 145°C or 150°C, so that the temperature of the third initial cholesteric liquid crystal portion 133a is higher than the clearing point of the liquid crystal molecules.

[0210] S2.3.2: Cooling the third initial cholesteric liquid crystal portion 133 a under ultraviolet light irradiation to solidify the third initial cholesteric liquid crystal portion 133 a to form a third cholesteric liquid crystal portion 133 .

[0211] By using the above process, the third initial cholesteric liquid crystal portion 133 a irradiated by the ultraviolet light can be cured to form the third cholesteric liquid crystal portion 133 including focal conic cholesteric liquid crystal.

[0212] Illustratively, the cooling rate of the third initial cholesteric liquid crystal portion 133 a may be 0.5° C. / min to 10.0° C. / min, for example, 0.5° C. / min, 2.0° C. / min, 4.0° C. / min, 6.0° C. / min, 8.0° C. / min, or 10.0° C. / min.

[0213] For example, the intensity of ultraviolet radiation can be 0.5 mW / cm 2 ~10.0mW / cm 2 , for example 0.5 mW / cm 2 , 1.5mW / cm 2 , 4.0mW / cm 2 、6.5mW / cm 2 , 8.0mW / cm 2 or 10.0mW / cm 2 .

[0214] It should be noted that FIG. 9 is a simplified schematic diagram obtained after removing all film layers except the film layers related to the cholesteric liquid crystal layer 130 from the color conversion substrate 100 .

[0215] In some embodiments, as shown in FIG9 , before forming the cholesteric liquid crystal layer 130 on one side of the substrate 110, an alignment layer 150 is further formed on one side of the substrate 110. The process for forming the alignment layer 150 is, for example, to first form an initial alignment layer 150 and then perform a photo-alignment treatment on the initial alignment layer 150. The process for forming the initial alignment layer 150 is, for example, a coating process.

[0216] As shown in FIG6 , the alignment layer 150 includes a first alignment portion 151, a second alignment portion 152, and a third alignment portion 153 arranged along a first direction X. The first alignment portion 151 is configured to align the liquid crystal molecules in the first cholesteric liquid crystal portion 131. The second alignment portion 152 is configured to align the liquid crystal molecules in the second cholesteric liquid crystal portion 132. The third alignment portion 153 is configured to align the liquid crystal molecules in the third cholesteric liquid crystal portion 133.

[0217] In some embodiments, the first cholesteric liquid crystal portion 131 includes a first chiral liquid crystal portion 1311 and a second chiral liquid crystal portion 1312, and the second cholesteric liquid crystal portion 132 includes a third chiral liquid crystal portion 1321 and a fourth chiral liquid crystal portion 1322. In this case, the cholesteric liquid crystal layer 130 is formed on one side of the substrate 110 and includes R1 to R6.

[0218] R1: A first sublayer in the initial cholesteric liquid crystal layer 130a is formed on one side of the substrate 110, and the first sublayer in the initial cholesteric liquid crystal layer 130a includes a first subportion of the first initial cholesteric liquid crystal portion 131a, a first subportion of the second initial cholesteric liquid crystal portion 132a, and a first subportion of the third initial cholesteric liquid crystal portion 133a.

[0219] The description of the formation process and materials (such as liquid crystal monomers, chiral additives, and photoinitiators) in step R1 can refer to the description of step S2.1 in steps S2.1 to S2.3 in the aforementioned method, and will not be repeated here.

[0220] For example, in the material forming the first sub-layer of the initial cholesteric liquid crystal layer 130 a , the chiral additive is a first chiral additive, which may have a structure represented by structural formula (IV).

[0221] R2: the first sub-portion of the first initial cholesteric liquid crystal portion 131 a is formed into the first chiral liquid crystal portion 1311 , and the first sub-portion of the second initial cholesteric liquid crystal portion 132 a is formed into the third chiral liquid crystal portion 1321 .

[0222] The description of the forming process in step R2 can refer to the description of step S2.2 in steps S2.1 to S2.3 in the aforementioned method, and will not be repeated here.

[0223] R3: the first sub-portion of the third initial cholesteric liquid crystal portion 133 a is formed into the first sub-portion of the third cholesteric liquid crystal portion 133 .

[0224] The description of the forming process in step R3 can refer to the description of step S2.3 in steps S2.1 to S2.3 in the aforementioned method, and will not be repeated here.

[0225] R4: A second sublayer in the initial cholesteric liquid crystal layer 130a is formed on one side of the first chiral liquid crystal portion 1311, the third chiral liquid crystal portion 1321 and the first subportion of the third cholesteric liquid crystal portion 133, and the second sublayer in the initial cholesteric liquid crystal layer 130a includes the second subportion of the first initial cholesteric liquid crystal portion 131a, the second subportion of the second initial cholesteric liquid crystal portion 132a and the second subportion of the third initial cholesteric liquid crystal portion 133a.

[0226] The description of the formation process and materials (such as liquid crystal monomers, chiral additives, and photoinitiators) in step R4 can refer to the description of step S2.1 in steps S2.1 to S2.3 in the aforementioned method, and will not be repeated here.

[0227] For example, in the material forming the second sub-layer of the initial cholesteric liquid crystal layer 130 a , the chiral additive is a second chiral additive, which may have a structure represented by structural formula (V).

[0228] It should be noted that the above-listed structural formulas are examples of the structures of primary and secondary chiral additives and are not intended to limit them. Furthermore, (IV) and (V) in the above structural formulas are aliases and are not part of the structure.

[0229] R5: the second sub-portion of the first initial cholesteric liquid crystal portion 131 a is formed into the second chiral liquid crystal portion 1312 , and the second sub-portion of the second initial cholesteric liquid crystal portion 132 a is formed into the fourth chiral liquid crystal portion 1322 .

[0230] The description of the forming process in step R5 can refer to the description of step S2.2 in steps S2.1 to S2.3 in the aforementioned method, and will not be repeated here.

[0231] R6: The second sub-portion of the third initial cholesteric liquid crystal portion 133 a is formed into the second sub-portion of the third cholesteric liquid crystal portion 133 .

[0232] The description of the forming process in step R6 can refer to the description of step S2.3 in steps S2.1 to S2.3 in the aforementioned method, and will not be repeated here.

[0233] It should be noted that the first sub-portion of the third cholesteric liquid crystal portion 133 and the second sub-portion of the third cholesteric liquid crystal portion 133 together constitute the third cholesteric liquid crystal portion 133 .

[0234] Some embodiments of the present disclosure further provide a display panel 1000. As shown in Figures 1 and 6 , the display panel 1000 includes: a color conversion substrate 100 as described in any of the above embodiments; and a light-emitting substrate 200. The light-emitting substrate 200 is opposite to the color conversion substrate 100 and is configured to emit a first color light L1.

[0235] The light-emitting substrate 200 emits a first color light L1, for example, a blue light. By placing the light-emitting substrate 200 opposite to the color conversion substrate 100 in any of the above-mentioned embodiments, the color conversion substrate 100 can convert the first color light L1 emitted by the light-emitting substrate 200 and located in the second sub-pixel area BB and the third sub-pixel area CC into a second color light L2 (for example, a red light) and a third color light L3 (for example, a green light), respectively. The second color light L2, the third color light L3, and the first color light L1 emitted from the first sub-pixel area AA are mixed to achieve full-color display of the display panel 1000.

[0236] The beneficial effects achieved by a display panel 1000 provided by some embodiments of the present disclosure are the same as the beneficial effects achieved by a color conversion substrate 100 provided by the above technical solution, and are not further described here.

[0237] In some embodiments, as shown in FIG. 1 and FIG. 6 , the display panel 1000 further includes a filling layer 300 located between the light emitting substrate 200 and the color conversion substrate 100 .

[0238] By providing the filling layer 300 between the light emitting substrate 200 and the color conversion substrate 100 , the cell gap between the color conversion substrate 100 and the display substrate can be filled, so that the light emitting substrate 200 and the color conversion substrate 100 are bonded together.

[0239] Exemplarily, the material of the filling layer 300 is an acrylic polymer material or an epoxy polymer material.

[0240] Illustratively, the thickness of the filling layer 300 may be 10 μm to 20 μm, for example, 10 μm, 12 μm, 15 μm, 18 μm, or 20 μm.

[0241] In some embodiments, the light-emitting substrate 200 includes any one of an OLED light-emitting substrate 200 , an LED (Light Emitting Diode) light-emitting substrate 200 , a Micro LED light-emitting substrate 200 , and a Mini LED light-emitting substrate 200 .

[0242] Based on the light-emitting substrate 200, the display panel 1000 can be any product or component with a display function, such as an OLED panel, an OLED TV, a Micro LED panel, a Micro LED TV, a Mini LED panel, a Mini LED TV, a monitor, a mobile phone, a navigation system, etc. The display panel 1000 can be any display panel 1000 that displays either moving (e.g., video) or fixed (e.g., still images), and whether text or images. More specifically, it is expected that the display panel 1000 of the described embodiments may be implemented in or associated with a variety of electronic devices, such as (but not limited to) mobile phones, wireless devices, personal data assistants (PDAs), handheld or portable computers, GPS receivers / navigators, cameras, MP4 video players, camcorders, game consoles, watches, clocks, calculators, television monitors, flat-panel displays, computer monitors, automotive displays (e.g., odometer displays, etc.), navigators, cockpit controls and / or displays, displays of camera views (e.g., displays of rearview cameras in vehicles), electronic photographs, electronic billboards or signs, projectors, architectural structures, packaging, and aesthetic structures (e.g., displays of images of a piece of jewelry), etc.

[0243] In some embodiments, as shown in FIG1 and FIG6 , the light-emitting substrate 200 is an OLED light-emitting substrate 200 ; the OLED light-emitting substrate 200 includes a cathode 220 and an anode 210 disposed opposite each other, and at least two light-emitting units 230 disposed between the cathode 220 and the anode 210. The light-emitting unit 230 includes a light-emitting layer 231 , which is configured to emit a first color light L1 toward the color conversion substrate 100 .

[0244] When the material of the first color conversion portion 121 includes a first quantum dot material, the material of the second color conversion portion 122 includes a second quantum dot material, and the light-emitting substrate 200 is an OLED light-emitting substrate 200, the display panel 1000 is a quantum dot (QD)-organic light-emitting diode device (QD-OLED). The OLED light-emitting substrate 200 emitting a first color light L1 (e.g., blue light) can be used as an excitation light source, and the first color conversion portion 121 including the first quantum dot material (e.g., red quantum dot material) and the second color conversion portion 122 including the second quantum dot material (e.g., green quantum dot material) can serve as the color conversion layer 120 (CCL). In this case, the display panel 1000 can combine the advantages of quantum dots (high brightness, high color volume, and high efficiency) with the advantages of true black state, high contrast, wide viewing angle, and wide color gamut of OLED devices, thereby achieving a high-quality display effect with the advantages of a wide color gamut, high color conversion efficiency (CCE), and wide viewing angle.

[0245] The OLED light-emitting substrate 200 includes a cathode 220 and an anode 210. During operation, voltages are applied to the anode 210 and cathode 220, respectively, generating an electric field between the two. This drives the holes in the anode 210 and the electrons in the cathode 220 to recombine in the light-emitting layer 231, thereby emitting the first color light L1.

[0246] In some embodiments, the material of the light emitting layer 231 includes a guest material, and the guest material is configured to emit the first color light L1.

[0247] For example, the guest material can be one or more of a fluorescent material, a phosphorescent material, and a thermally activated delayed fluorescent material. Fluorescent materials include, for example, DCM, DCJ, Alq3, or DPVPi; phosphorescent materials include, for example, Pt7O7, PtOEP, FirPic, or Ir(ppy)3; and thermally activated delayed fluorescent materials include, for example, DACR-DPTX, TPA-DMAC, or 4CzIPN.

[0248] For example, the wavelength of the first color light L1 emitted by the light emitting layer 231 may be 450 nm to 470 nm, for example, 450 nm, 455 nm, 460 nm, 465 nm or 470 nm, etc. In this case, the first color light L1 is blue light.

[0249] For example, the half-peak width of the emission spectrum of the first color light L1 emitted by the light-emitting layer 231 is 15 nm to 30 nm, such as 15 nm, 20 nm, 25 nm or 30 nm, etc. In this way, the color purity of the first color light L1 emitted by the light-emitting substrate 200 can be improved.

[0250] In some embodiments, the light-emitting unit 230 further includes a hole transport functional layer disposed between the light-emitting layer 231 and the anode 210, and / or an electron transport functional layer disposed between the light-emitting layer 231 and the cathode 220. The hole transport functional layer may include, for example, at least one of a hole injection layer, a hole transport layer, and an electron blocking layer, thereby improving hole transport performance. The electron transport functional layer may include, for example, at least one of an electron injection layer, an electron transport layer, and a hole blocking layer, thereby improving electron transport performance.

[0251] In some examples, as shown in Figures 1 and 6, the anode 210 can be located on a side of the light-emitting unit 230 away from the color conversion substrate 100, and the cathode 220 can be located on a side of the light-emitting unit 230 closer to the color conversion substrate 100. In this case, the anode 210, at least two light-emitting units 230, and the cathode 220 are stacked along the second direction Y, and the anode 210, at least two light-emitting units 230, and the cathode 220 are arranged in sequence along a direction closer to the color conversion substrate 100. In other examples, the cathode 220 can be located on a side of the light-emitting unit 230 away from the color conversion substrate 100, and the anode 210 can be located on a side of the light-emitting unit 230 closer to the color conversion substrate 100.

[0252] The aforementioned light-emitting substrate 200 includes at least two light-emitting units 230 (e.g., n light-emitting units 230), forming a laminated light-emitting substrate 200. With this configuration, firstly, because OLEDs are current-driven, under the same current density, the luminance of the laminated OLED light-emitting substrate 200, comprised of n identical light-emitting units 230, is n times greater than that of a conventional OLED light-emitting substrate 200 comprised of a single light-emitting unit 230. Therefore, the current efficiency of the laminated OLED light-emitting substrate 200 is n times greater than that of a conventional OLED light-emitting substrate 200. Secondly, the OLED light-emitting substrate 200 operates at a certain brightness. Under the same brightness, the current density driving the laminated OLED light-emitting substrate 200 is 1 / nth of the current density driving a conventional OLED light-emitting substrate 200. Since a higher current density driving the OLED light-emitting substrate 200 accelerates its aging and shortens its lifespan, the lifespan of the laminated OLED light-emitting substrate 200 is extended.

[0253] In some embodiments, as shown in FIG. 1 and FIG. 6 , the light-emitting substrate 200 further includes a charge generation layer 240 . The charge generation layer 240 is located between two adjacent light-emitting units 230 among the plurality of light-emitting units 230 .

[0254] Through the charge generation layer 240, multiple light-emitting units 230 can be sequentially connected in a direction perpendicular to the light-emitting surface (e.g., the second direction Y). Furthermore, the charge generation layer 240 in the stacked OLED light-emitting substrate 200 not only connects the light-emitting units 230 but also helps improve the efficiency of charge (holes or electrons) generation, significantly impacting the performance of the light-emitting substrate 200.

[0255] For example, the charge generation layer 240 may include a plurality of stacked inorganic material layers, such as Li / Ca / Ag, LiF / Al / Au, or Al / WO3 / Au. Alternatively, the charge generation layer 240 may include a stacked inorganic material layer and an organic material layer, such as Alq3(Bphen):Li, Alq3(BCP):Li, Bphen:Rb2CO3, or LiF / ZnPc:C 60 / MoO3, etc. Alternatively, the charge generation layer 240 may include a plurality of stacked organic material layers, such as Alq3:Li / HAT-CN, Bphen:Li / HAT-CN, F 16 CuPc / CuPc or Li:Bphen / Al / F4-TCNQ / HAT-CN, etc.

[0256] For example, the charge generation layer 240 (CGL) may include an electron generation layer (n-CGL) and a hole generation layer (p-CGL) stacked together, wherein the electron generation layer is closer to the anode 210 than the hole generation layer.

[0257] In some embodiments, as shown in Figures 1 and 6, the light-emitting substrate 200 further includes a second encapsulation layer 250. When the cathode 220 is closer to the color conversion substrate 100 than the anode 210, the second encapsulation layer 250 can be located on a side of the cathode 220 away from the light-emitting unit 230.

[0258] By such a configuration, the second encapsulation layer 250 can be used to cover the light-emitting unit 230 to prevent moisture and oxygen in the external environment from entering the light-emitting unit 230 and damaging the material of the light-emitting unit 230 (such as the guest material) and shortening the life of the light-emitting substrate 200.

[0259] Exemplarily, the second encapsulation layer 250 may include a plurality of stacked second sub-encapsulation layers, and the material of the second sub-encapsulation layer may be an organic material or an inorganic material. The organic material is, for example, an acrylate polymer material or an epoxy polymer material. The inorganic material is, for example, SiOx or SiNx. The thickness of the second sub-encapsulation layer containing organic material may be 6μm to 12μm, for example, 6μm, 7μm, 9μm, 11μm or 12μm. The thickness of the second sub-encapsulation layer containing inorganic material may be 0.4μm to 1.6μm, for example, 0.4μm, 0.8μm, 1.2μm or 1.6μm.

[0260] In some examples, the light-emitting substrate further includes a driving circuit disposed on a side of the anode 210 away from the light-emitting unit. The driving circuit can generate a driving current. The light-emitting substrate can emit light under the driving effect of the driving current generated by the driving circuit.

[0261] In order to objectively evaluate the technical effects of the embodiments of the present disclosure, the technical solutions provided by the present disclosure will be described in detail and exemplarily through the following experimental examples and comparative examples.

[0262] In the following embodiment, as shown in FIG6 , a display panel 1000 includes a color conversion substrate 100, a light-emitting substrate 200, and a filling layer 300 disposed therebetween. The color conversion substrate 100 includes a base 110, a first color filter portion 1721, a second color filter portion 1722, a third color filter portion 1723, a light absorption pattern 171, a barrier pattern 160, an alignment layer 150, a first cholesteric liquid crystal portion 131, a second cholesteric liquid crystal portion 132, a third cholesteric liquid crystal portion 133, a first color conversion portion 121, a second color conversion portion 122, a light-transmitting portion 140, and a first encapsulation layer 180. The first color conversion portion 121 is made of a red quantum dot material, and the second color conversion portion 122 is made of a green quantum dot material. The light-emitting substrate 200 is a laminated light-emitting substrate 200, and the number of light-emitting units 230 is three. Specifically, the light-emitting substrate 200 includes a stacked backplane (including an anode 210), a first light-emitting unit 230, a first charge generation layer 240, a second light-emitting unit 230, a second charge generation layer 240, a third light-emitting unit 230, a cathode 220, and a second encapsulation layer 250. The first color light L1 emitted by the first light-emitting unit 230, the second light-emitting unit 230, and the third light-emitting unit 230 is blue light. For a description of the position, connection, material, shape, etc. of the above structure, please refer to the description of the above embodiment and will not be repeated here.

[0263] In the following comparative example, as shown in FIG10 , the structural difference compared with the above embodiment is that the alignment layer 150 , the first cholesteric liquid crystal portion 131 , the second cholesteric liquid crystal portion 132 , and the third cholesteric liquid crystal portion 133 are not provided.

[0264] In the following examples and comparative examples, the third cholesteric liquid crystal portion 133 was prepared using different UV irradiation intensities. Furthermore, the first and second cholesteric liquid crystal portions 131 and 132 had different thicknesses and structures. Using an optoelectronic testing system, the blue light leakage rate (blue leakage), color conversion efficiency (CCE), color gamut, color shift, and power consumption of the display panel 1000 were compared. In the following comparative examples and examples, the testing conditions for the display panel 1000 were the same.

[0265] Example 1

[0266] A display panel 1000 is prepared, including P1 to P9.

[0267] P1: providing a substrate 110 .

[0268] P2: A light absorption pattern 171 is formed on one side of the substrate 110 by coating and photolithography processes. The light absorption pattern 171 includes a plurality of second openings N.

[0269] P3: A first color filter portion 1721 , a second color filter portion 1722 , and a third color filter portion 1723 are formed in the plurality of second openings N by coating and photolithography processes, thereby forming a light blocking layer 170 .

[0270] P4: A blocking pattern 160 is formed on a side of the light blocking layer 170 away from the substrate 110 by coating and photolithography processes. The blocking pattern 160 includes a plurality of first openings Q.

[0271] P5: coating the material of the initial alignment layer 150 on the side of the blocking pattern 160 away from the light blocking layer 170 to form the initial alignment layer 150 , and performing a photo-alignment treatment on the initial alignment layer 150 to form the alignment layer 150 located in the second opening N.

[0272] P6: Referring to the above methods R1 to R6, a cholesteric liquid crystal layer 130 is formed on the side of the alignment layer 150 away from the light-blocking layer 170 .

[0273] In R1 and R4, the precursor includes a liquid crystal monomer, a chiral additive, and a photoinitiator in a mass ratio of 93:3:4. The liquid crystal monomer has the structure represented by structural formula (II), and the photoinitiator has the structure represented by structural formula (III). In R1, the chiral additive has the structure represented by structural formula (IV), and the thickness of the first sublayer of the initial cholesteric liquid crystal layer 130a is 1.5 μm. In R4, the chiral additive has the structure represented by structural formula (V), and the thickness of the second sublayer of the initial cholesteric liquid crystal layer 130a is 1.5 μm.

[0274] In R2 and R5, the intensity of ultraviolet light irradiation on the first initial cholesteric liquid crystal portion 131a and the second initial cholesteric liquid crystal portion 132a is 7 mW / cm 2 The UV irradiation time of the first initial cholesteric liquid crystal portion 131a and the second initial cholesteric liquid crystal portion 132a is 5 minutes. In R3 and R6, the heating temperature of the third initial cholesteric liquid crystal portion 133a is 140°C, the cooling rate of the third initial cholesteric liquid crystal portion 133a is 3°C / min, and the UV irradiation intensity of the third initial cholesteric liquid crystal portion 133a is 3.0 mW / cm 2 .

[0275] P7: A first color conversion portion 121 is formed on a side of the first cholesteric liquid crystal portion 131 away from the alignment layer 150 by using a coating and photolithography process; a second color conversion portion 122 is formed on a side of the second cholesteric liquid crystal portion 132 away from the alignment layer 150 by using a coating and photolithography process; and a light-transmitting portion 140 is formed on a side of the third cholesteric liquid crystal portion 133 away from the alignment layer 150 by using a coating and photolithography process.

[0276] P8: A first encapsulation layer 180 is formed on the first color conversion portion 121 , the second color conversion portion 122 , and the side of the light-transmitting portion 140 away from the cholesteric liquid crystal layer 130 by coating and photolithography processes. The first encapsulation layer 180 is made of an inorganic material.

[0277] P9: Using a cell-aligning process, the color conversion substrate 100 and the light-emitting substrate 200 are bonded together.

[0278] After forming the first chiral liquid crystal portion 1311, the third chiral liquid crystal portion 1321, and the first sub-portion of the third cholesteric liquid crystal portion 133 in P6, the microscopic morphology of the first cholesteric liquid crystal portion 131 was measured, as shown in FIG11 ; the polarization microscopic texture of the first cholesteric liquid crystal portion 131 was measured, as shown in FIG12 ; the transmission spectrum of the first cholesteric liquid crystal portion 131 was measured, as shown in FIG13 ; the microscopic morphology of the third cholesteric liquid crystal portion 133 was measured, as shown in FIG14 ; and the polarization microscopic texture of the third cholesteric liquid crystal portion 133 was measured, as shown in FIG15 . FIG11 and FIG14 were measured using a scanning electron microscope (S-4800) at a test voltage of 5 kV.

[0279] After P9, the angular light intensity distributions of the first sub-pixel area AA, the second sub-pixel area BB, and the third sub-pixel area CC in the display panel 1000 are measured, and the results are shown in FIG. 16 .

[0280] Example 2

[0281] The display panel 1000 was prepared by referring to the methods P1 to P9 above. The preparation conditions were the same as those in Example 1, except for the thickness of the first sublayer of the initial cholesteric liquid crystal layer 130 a, the thickness of the second sublayer of the initial cholesteric liquid crystal layer 130 a, and the intensity of the ultraviolet light irradiating the third initial cholesteric liquid crystal portion 133 a.

[0282] In this embodiment, the thickness of the first sublayer of the initial cholesteric liquid crystal layer 130a is 1.0 μm; the thickness of the second sublayer of the initial cholesteric liquid crystal layer 130a is 1.0 μm. The intensity of ultraviolet light irradiation of the third initial cholesteric liquid crystal portion 133a is 3.0 mW / cm 2 .

[0283] Example 3

[0284] The display panel 1000 was prepared by referring to the methods P1 to P9 above. The preparation conditions were the same as those in Example 1, except for the thickness of the first sublayer of the initial cholesteric liquid crystal layer 130 a, the thickness of the second sublayer of the initial cholesteric liquid crystal layer 130 a, and the intensity of the ultraviolet light irradiation of the third initial cholesteric liquid crystal portion 133 a.

[0285] In this embodiment, the thickness of the first sublayer of the initial cholesteric liquid crystal layer 130a is 2.0 μm; the thickness of the second sublayer of the initial cholesteric liquid crystal layer 130a is 2.0 μm. The intensity of ultraviolet light irradiation of the third initial cholesteric liquid crystal portion 133a is 3.0 mW / cm 2 .

[0286] Example 4

[0287] The display panel 1000 was prepared by referring to the methods P1 to P9 above. The preparation conditions were the same as those in Example 1, except for the thickness of the first sublayer of the initial cholesteric liquid crystal layer 130 a, the thickness of the second sublayer of the initial cholesteric liquid crystal layer 130 a, and the intensity of the ultraviolet light irradiation of the third initial cholesteric liquid crystal portion 133 a.

[0288] In this embodiment, the thickness of the first sublayer of the initial cholesteric liquid crystal layer 130a is 1.5 μm; the thickness of the second sublayer of the initial cholesteric liquid crystal layer 130a is 1.5 μm. The intensity of ultraviolet light irradiation of the third initial cholesteric liquid crystal portion 133a is 1.0 mW / cm 2 .

[0289] Example 5

[0290] The display panel 1000 was prepared by referring to the methods P1 to P9 above. The preparation conditions were the same as those in Example 1, except for the thickness of the first sublayer of the initial cholesteric liquid crystal layer 130 a, the thickness of the second sublayer of the initial cholesteric liquid crystal layer 130 a, and the intensity of the ultraviolet light irradiation of the third initial cholesteric liquid crystal portion 133 a.

[0291] In this embodiment, the thickness of the first sublayer of the initial cholesteric liquid crystal layer 130a is 1.5 μm; the thickness of the second sublayer of the initial cholesteric liquid crystal layer 130a is 1.5 μm. The intensity of ultraviolet radiation of the third initial cholesteric liquid crystal portion 133a is 5.0 mW / cm 2 .

[0292] Example 6

[0293] Referring to the methods of P1 to P9 above, a display panel 1000 is prepared. Except for P6, the preparation conditions are the same as those of Example 1.

[0294] In this embodiment, P6: Referring to the methods R1 to R3 above, a cholesteric liquid crystal layer 130 is formed on the side of the alignment layer 150 away from the light-blocking layer 170. That is, in this embodiment, in the cholesteric liquid crystal layer 130 prepared in P6, the first cholesteric liquid crystal portion 131 includes only the first chiral liquid crystal layer, the second cholesteric liquid crystal portion 132 includes only the third chiral liquid crystal layer, and the third cholesteric liquid crystal portion 133 includes only the first subportion of the third cholesteric liquid crystal portion 133.

[0295] Among them, in R1, the precursor includes a liquid crystal monomer, a chiral additive and a photoinitiator, and the mass ratio of the three is 93:3:4, wherein the structure of the liquid crystal monomer is the structure shown in structural formula (II); the structure of the photoinitiator is the structure shown in structural formula (III), and the structure of the chiral additive is the structure shown in structural formula (IV). The thickness of the first sublayer of the initial cholesteric liquid crystal layer 130a is 3.0 μm.

[0296] In R2, the intensity of ultraviolet light irradiation on the first initial cholesteric liquid crystal portion 131a and the second initial cholesteric liquid crystal portion 132a is 7 mW / cm 2 The UV irradiation time of the first initial cholesteric liquid crystal portion 131a and the second initial cholesteric liquid crystal portion 132a is 5 minutes. In R3, the heating temperature of the third initial cholesteric liquid crystal portion 133a is 140°C, the cooling rate of the third initial cholesteric liquid crystal portion 133a is 3°C / min, and the intensity of the UV irradiation of the third initial cholesteric liquid crystal portion 133a is 3.0 mW / cm 2 .

[0297] Example 7

[0298] Referring to the methods of P1 to P9 above, a display panel 1000 is prepared. Except for P6, the preparation conditions are the same as those of Example 1.

[0299] In this embodiment, P6: Referring to the methods R4 to R6 above, a cholesteric liquid crystal layer 130 is formed on the side of the alignment layer 150 away from the light-blocking layer 170. That is, in this embodiment, in the cholesteric liquid crystal layer 130 prepared in P6, the first cholesteric liquid crystal portion 131 includes only the second chiral liquid crystal layer, the second cholesteric liquid crystal portion 132 includes only the fourth chiral liquid crystal layer, and the third cholesteric liquid crystal portion 133 includes only the second subportion of the third cholesteric liquid crystal portion 133.

[0300] Among them, in R4, the precursor includes a liquid crystal monomer, a chiral additive and a photoinitiator, and the mass ratio of the three is 93:3:4, wherein the structure of the liquid crystal monomer is the structure shown in structural formula (II); the structure of the photoinitiator is the structure shown in structural formula (III), and the structure of the chiral additive is the structure shown in structural formula (V). The thickness of the second sublayer of the initial cholesteric liquid crystal layer 130a is 3.0 μm.

[0301] In R5, the intensity of ultraviolet light irradiation on the first initial cholesteric liquid crystal portion 131a and the second initial cholesteric liquid crystal portion 132a is 7 mW / cm 2 The UV irradiation time of the first initial cholesteric liquid crystal portion 131a and the second initial cholesteric liquid crystal portion 132a is 5 minutes. In R6, the heating temperature of the third initial cholesteric liquid crystal portion 133a is 140°C, the cooling rate of the third initial cholesteric liquid crystal portion 133a is 3°C / min, and the intensity of the UV irradiation of the third initial cholesteric liquid crystal portion 133a is 3.0 mW / cm 2 .

[0302] Comparative Example

[0303] Referring to the methods P1-P4 and P7-P9 above, a display panel 1000 is fabricated. In P7, a coating and photolithography process are used to form the first color conversion portion 121, the second color conversion portion 122, and the light-transmitting portion 140 within the plurality of second openings N. That is, in this comparative example, the color conversion substrate 100 does not include the cholesteric liquid crystal layer 130.

[0304] In this comparative example, after P9, the angular light intensity distribution of the first sub-pixel area AA in the display panel 1000 is measured. The result is shown in FIG. 16 and compared with the angular light intensity distribution measured in Example 1.

[0305] As shown in FIG. 16 , compared with the angular intensity distribution of the blue light emitted from the first sub-pixel region AA in the comparative example, the angular intensity distribution of the blue light emitted from the first sub-pixel region AA in the comparative example is closer to the angular intensity distribution of the red light emitted from the second sub-pixel region BB and the angular intensity distribution of the green light emitted from the third sub-pixel region CC. This is because in the first embodiment, a third cholesteric liquid crystal portion 133 is disposed between the substrate 110 and the light-transmitting portion 140. The cholesteric liquid crystal in the third cholesteric liquid crystal portion 133 is in a focal conic state, which can disperse the portion of the first color light L1 near the normal viewing angle toward a wide viewing angle. Compared to the comparative example, the angular distribution of the first color light L1 emitted from the first sub-pixel region AA is relatively wider, which can improve the matching of the angular distributions of the light emitted from the first sub-pixel region AA, the second sub-pixel region BB, and the third sub-pixel region CC, thereby alleviating the problem of angular color shift.

[0306] Based on the above-described Examples 1 to 7 and the comparative example, a photoelectric testing system was used to measure the blue light leakage rate (blue leakage), color conversion efficiency (CCE), color gamut (color gamut), color shift (color shift), and power consumption of the display panel 1000 of Examples 1 to 7 and the comparative example. The data for blue light leakage rate (blue leakage), color conversion efficiency (CCE), color gamut (color gamut), color shift (color shift), and power consumption were measured using the comparative example as a reference. The test results are shown in Table 1 below.

[0307] Table 1

[0308] It should be noted that the blue light leakage rate in Table 1 is the average of the blue light leakage rates of the light emitted by the second sub-pixel region BB and the third sub-pixel region CC. The color conversion efficiency in Table 1 is the average of the color conversion efficiencies of the first color conversion unit 121 and the second color conversion unit 122. The color gamut in Table 1 is determined based on the CIE 1931 chromaticity diagram. The color shift in Table 1 is measured at a viewing angle of 45°.

[0309] As shown in Table 1, when comparing Examples 1 to 7 with the comparative example, Examples 1 to 7 exhibit lower blue light leakage rates, higher color conversion efficiency, wider color gamut, and lower power consumption. This is because, in the color conversion substrates 100 of Examples 1 to 7, a first cholesteric liquid crystal region 131 is disposed between the substrate 110 and the first color conversion region 121, and a second cholesteric liquid crystal region 132 is disposed between the substrate 110 and the second color conversion region 122. Furthermore, the cholesteric liquid crystals in the first and second cholesteric liquid crystal regions 131 and 132 are planar. This allows the first color light L1, which passes through the first and second color conversion regions 121 and 122 but remains unconverted, to be reflected back to the first and second color conversion regions 121 and 122, thereby exciting the color conversion materials in the first and second color conversion regions 121 and 122 and converting them into the second and third color light L2 and L3. This reduces the amount of first color light L1 leaking from the second sub-pixel region BB and the third sub-pixel region CC, resulting in a lower blue light leakage rate. Furthermore, the reflected first color light L1 can be re-entered by the first color conversion portion 121 and the second color conversion portion 122, stimulating the color conversion materials therein and converting them into the second color light L2 and the third color light L3. This improves color conversion efficiency and reduces power consumption of the display panel 1000. Furthermore, it improves the color purity of the display panel 1000, preventing leaked first color light L1 from entering adjacent sub-pixel regions and causing crosstalk, thereby expanding the color gamut of the display panel 1000.

[0310] As shown in Table 1, when comparing Examples 1 to 5 with Examples 6 to 7, Examples 1 to 5 have lower blue light leakage rates, higher color conversion efficiency, wider color gamut, and lower power consumption. This is because in the color conversion substrate 100 of Examples 1 to 5, the first cholesteric liquid crystal portion 131 includes a first chiral liquid crystal portion 1311 and a second chiral liquid crystal portion 1312 with opposite helical directions, and the second cholesteric liquid crystal portion 132 includes a third chiral liquid crystal portion 1321 and a fourth chiral liquid crystal portion 1322 with opposite helical directions. As a result, the portion of the first color light L1 whose helical direction is the same as that of the liquid crystal molecules in the first chiral liquid crystal portion 1311 and the third chiral liquid crystal portion 1321 can be converted by the first chiral liquid crystal portion 1311. The first color light L1 is reflected by the first and third chiral liquid crystal portions 1311 and 1321 back to the first color conversion portion 121 and the second color conversion portion 122, and converted into the second color light L2 and the third color light L3. Simultaneously, the portion of the first color light L1 whose helical direction is opposite to the helical direction of the liquid crystal molecules in the first and third chiral liquid crystal portions 1311 and 1321 is reflected by the second and fourth chiral liquid crystal portions 1312 and 1322 back to the first color conversion portion 121 and the second color conversion portion 122, and converted into the second color light L2 and the third color light L3. This improves the reflectivity of the first and second cholesteric liquid crystal portions 131 and 132 for the first color light L1. This reduces the amount of first color light L1 leaking from the second and third sub-pixel regions BB and CC, resulting in a lower blue light leakage rate. Second, the reflected first color light L1 can be re-entered into the first color conversion unit 121 and the second color conversion unit 122, stimulating the color conversion materials therein and converting the reflected first color light L1 into the second color light L2 and the third color light L3, thereby improving color conversion efficiency and reducing power consumption of the display panel 1000. Third, the color purity of the display panel 1000 can be improved, preventing the leaked first color light L1 from entering adjacent sub-pixel areas and causing crosstalk, thereby widening the color gamut of the display panel 1000.

[0311] As shown in Table 1, Examples 1 to 7 exhibit lower color shift compared to the comparative example. This is because in Examples 1 to 7, a third cholesteric liquid crystal portion 133 is disposed between the substrate 110 and the light-transmitting portion 140. The cholesteric liquid crystal in the third cholesteric liquid crystal portion 133 is in a focal conic state, which disperses the portion of the first color light L1 near the normal viewing angle toward a wider viewing angle. Compared to the comparative example, the angular distribution of the first color light L1 emitted from the first sub-pixel region AA is relatively wide, improving the matching of the angular distributions of the light emitted from the first sub-pixel region AA, the second sub-pixel region BB, and the third sub-pixel region CC, thereby alleviating the problem of angular color shift.

[0312] The above description is merely a specific embodiment of the present disclosure, but the scope of protection of the present disclosure is not limited thereto. Any changes or substitutions that a person skilled in the art can conceive within the technical scope disclosed in the present disclosure should be included within the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope of protection of the claims.

Claims

1. A color conversion substrate, comprising: substrate; A color conversion layer is located on one side of the substrate; The color conversion layer includes a first color conversion portion; the first color conversion portion is configured to: convert a first color light incident on the first color conversion portion into a second color light; A cholesteric liquid crystal layer; the cholesteric liquid crystal layer comprises a first cholesteric liquid crystal portion located between the substrate and the first color conversion portion; the first cholesteric liquid crystal portion is configured to: reflect unconverted light in the first color light back to the first color conversion portion.

2. The color conversion substrate according to claim 1, wherein: The color conversion layer further includes a second color conversion portion arranged along a first direction with the first color conversion portion, the first direction intersecting with the thickness direction of the substrate, the second color conversion portion being configured to: convert the first color light incident on the second color conversion portion into a third color light; The cholesteric liquid crystal layer further includes a second cholesteric liquid crystal portion located between the substrate and the second color conversion portion; the second cholesteric liquid crystal portion is configured to reflect unconverted light in the first color light back to the second color conversion portion.

3. The color conversion substrate according to claim 2, wherein: The cholesteric liquid crystals in the first cholesteric liquid crystal portion and the second cholesteric liquid crystal portion are in a planar state.

4. The color conversion substrate according to any one of claims 1 to 3, wherein It also includes a light-transmitting portion arranged along a first direction with the color conversion layer, the first direction intersects with a thickness direction of the substrate, and the first color light passes through the light-transmitting portion; The cholesteric liquid crystal layer further includes a third cholesteric liquid crystal portion located between the substrate and the light-transmitting portion; the third cholesteric liquid crystal portion is configured to disperse a portion of the first color light passing through the light-transmitting portion close to a normal viewing angle toward a large viewing angle.

5. The color conversion substrate according to claim 4, wherein: The cholesteric liquid crystal in the third cholesteric liquid crystal portion is in a focal conic state.

6. The color conversion substrate according to any one of claims 1 to 5, wherein The first cholesteric liquid crystal portion includes a first chiral liquid crystal portion and a second chiral liquid crystal portion which are stacked; the helical direction of the liquid crystal molecules in the first chiral liquid crystal portion is opposite to the helical direction of the liquid crystal molecules in the second chiral liquid crystal portion; In the case where the cholesteric liquid crystal layer further includes the second cholesteric liquid crystal portion, the second cholesteric liquid crystal portion includes a third chiral liquid crystal portion and a fourth chiral liquid crystal portion which are stacked; the spiral direction of the liquid crystal molecules in the third chiral liquid crystal portion is opposite to the spiral direction of the liquid crystal molecules in the fourth chiral liquid crystal portion.

7. The color conversion substrate according to any one of claims 2 to 6, wherein The helical pitch of the liquid crystal molecules in the first cholesteric liquid crystal portion is greater than or equal to 270 nm and less than or equal to 310 nm; the helical pitch of the liquid crystal molecules in the second cholesteric liquid crystal portion is greater than or equal to 270 nm and less than or equal to 310 nm.

8. The color conversion substrate according to any one of claims 2 to 7, wherein The first color light is blue light; the central reflection wavelength of the first cholesteric liquid crystal portion is greater than or equal to 450nm and less than or equal to 470nm; the central reflection wavelength of the second cholesteric liquid crystal portion is greater than or equal to 450nm and less than or equal to 470nm.

9. The color conversion substrate according to any one of claims 2 to 8, wherein The half-peak width of the transmission spectrum of the first cholesteric liquid crystal portion is greater than or equal to 70 nm and less than or equal to 100 nm; the half-peak width of the transmission spectrum of the second cholesteric liquid crystal portion is greater than or equal to 70 nm and less than or equal to 100 nm.

10. The color conversion substrate according to any one of claims 2 to 9, wherein It also includes an alignment layer located between the cholesteric liquid crystal layer and the substrate, the alignment layer includes a first alignment portion, a second alignment portion and a third alignment portion arranged along a first direction; the first alignment portion is configured to: align the liquid crystal molecules in the first cholesteric liquid crystal portion; the second alignment portion is configured to: align the liquid crystal molecules in the second cholesteric liquid crystal portion; the third alignment portion is configured to: align the liquid crystal molecules in the third cholesteric liquid crystal portion.

11. The color conversion substrate according to any one of claims 4 to 10, wherein The haze of the third cholesteric liquid crystal portion is greater than or equal to 3% and less than or equal to 8%.

12. The color conversion substrate according to any one of claims 4 to 11, wherein The transmittance of the third cholesteric liquid crystal portion to light in the first wavelength band is greater than or equal to 90%; the minimum wavelength of the first wavelength band is 450nm, and the maximum wavelength of the first wavelength band is 470nm.

13. The color conversion substrate according to any one of claims 1 to 12, wherein The thickness of the cholesteric liquid crystal layer is greater than or equal to 2 μm and less than or equal to 6 μm.

14. The color conversion substrate according to any one of claims 2 to 13, wherein The material of the first color conversion unit includes a first quantum dot material; the material of the second color conversion unit includes a second quantum dot material.

15. The color conversion substrate according to any one of claims 4 to 14, wherein It also includes a blocking pattern, which includes a plurality of first openings, wherein the first color conversion portion and the first cholesteric liquid crystal portion are located in one of the first openings; the second color conversion portion and the second cholesteric liquid crystal portion are located in another of the first openings; and the light-transmitting portion and the third cholesteric liquid crystal portion are located in another of the first openings.

16. The color conversion substrate according to any one of claims 4 to 15, wherein It also includes a light-blocking layer located between the cholesteric liquid crystal layer and the substrate, the light-blocking layer including: The light absorption pattern includes a plurality of second openings, wherein the plurality of second openings are directly opposite to the plurality of first openings; A plurality of color filter portions are located on a side of the substrate close to the cholesteric liquid crystal layer; the color filter portion is arranged in one of the second openings; the plurality of color filter portions include a first color filter portion directly opposite to the first color conversion portion, a second color filter portion directly opposite to the second color conversion portion, and a third color filter portion directly opposite to the light-transmitting portion.

17. A method for preparing a color conversion substrate, comprising: providing a substrate; forming a cholesteric liquid crystal layer on one side of the substrate; the cholesteric liquid crystal layer includes a first cholesteric liquid crystal part; A color conversion layer is formed on a side of the cholesteric liquid crystal layer away from the substrate; the color conversion layer includes a first color conversion portion of the first cholesteric liquid crystal portion on a side away from the substrate; The first color conversion unit is configured to convert the first color light irradiated to the first color conversion unit into the second color light; and the first cholesteric liquid crystal unit is configured to reflect the unconverted light in the first color light back to the first color conversion unit.

18. The method for preparing a color conversion substrate according to claim 17, wherein: The color conversion substrate further includes a light-transmitting portion arranged along a first direction with the color conversion layer, the first direction intersecting with a thickness direction of the substrate; the first color light can pass through the light-transmitting portion; The color conversion layer further includes a second color conversion portion arranged along the first direction with the first color conversion portion, the second color conversion portion being configured to: convert the first color light incident on the second color conversion portion into a third color light; Forming a cholesteric liquid crystal layer on one side of the substrate comprises: forming an initial cholesteric liquid crystal layer on one side of the substrate, wherein the initial cholesteric liquid crystal layer includes a first initial cholesteric liquid crystal portion, a second initial cholesteric liquid crystal portion and a third initial cholesteric liquid crystal portion; The first initial cholesteric liquid crystal portion is formed into the first cholesteric liquid crystal portion, and the second initial cholesteric liquid crystal portion is formed into the second cholesteric liquid crystal portion; the second cholesteric liquid crystal portion is located between the substrate and the second color conversion portion; the second cholesteric liquid crystal portion is configured to: reflect the unconverted light in the first color light back to the second color conversion portion; The third initial cholesteric liquid crystal portion is formed into a third cholesteric liquid crystal portion; the third cholesteric liquid crystal portion is located between the substrate and the light-transmitting portion, and the third cholesteric liquid crystal portion is configured to disperse the portion of the first color light passing through the light-transmitting portion close to the normal viewing angle toward a large viewing angle.

19. A display panel comprising the color conversion substrate according to any one of claims 1 to 16; It also includes a light-emitting substrate, which is opposite to the color conversion substrate; the light-emitting substrate is configured to emit the first color light.

20. The display panel according to claim 19, wherein: The light-emitting substrate includes any one of an OLED light-emitting substrate, an LED light-emitting substrate, a Micro LED light-emitting substrate, and a Mini LED light-emitting substrate.

21. The display panel according to claim 19 or 20, wherein: The light-emitting substrate is an OLED light-emitting substrate; The OLED light-emitting substrate comprises: a cathode and an anode arranged opposite to each other, and at least two light-emitting units arranged between the cathode and the anode; The light-emitting unit includes a light-emitting layer, and the light-emitting layer is configured to emit the first color light to the color conversion substrate.

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