Display panel, preparation method thereof and display device

Abstract

The application provides a display panel and a preparation method thereof and a display device, and relates to the technical field of display. The display panel can improve light output rate and normal viewing angle light emission. The display panel comprises: a substrate and a base arranged oppositely; a plurality of light emitting units arranged in an array, the light emitting units being arranged between the substrate and the base; a plurality of scattering structures arranged in an array; the scattering structures are arranged on a light emitting side of the light emitting units and comprise at least one scattering unit, the scattering unit comprises a matrix and a plurality of scattering particles arranged on one side of the matrix, the particle diameter of the scattering particles and the distance between the normal projection of the scattering particles on the substrate and the central projection satisfy a positive correlation relationship, and the central projection is the normal projection of the center of the light emitting unit on the substrate.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a display panel and a manufacturing method thereof, and a display device. Background Art

[0002] With the continuous development of the television industry, high-color gamut displays have become a mainstream trend. QLED (Quantum Dot Light Emitting Diode) displays, which utilize electroluminescent properties, offer not only a wide color gamut but also high brightness, fast response, and enhanced HDR (High-Dynamic Range) effects, making them promising for widespread application. However, these displays suffer from low light extraction efficiency and require further optimization. Summary of the Invention

[0003] The embodiments of this application adopt the following technical solutions:

[0004] In one aspect, a display panel is provided, comprising:

[0005] substrate;

[0006] A plurality of light-emitting units arranged in an array on the substrate, wherein the light-emitting units are arranged between the substrate and the base;

[0007] A plurality of scattering structures arranged in an array; the scattering structure is arranged on the light-emitting side of the light-emitting unit and includes at least one scattering unit, the scattering unit includes a matrix and a plurality of scattering particles arranged on one side of the matrix, the particle size of the scattering particles and the distance between the orthographic projection and the central projection of the scattering particles on the substrate satisfy a positive correlation, and the central projection is the orthographic projection of the center of the light-emitting unit on the substrate.

[0008] Optionally, the particle size of the scattering particles is D, the distance between the orthographic projection of the scattering particles on the substrate and the central projection is x, and D and x satisfy:

[0009]

[0010] Where f(x, D) is the particle distribution density function.

[0011] Optionally, in the scattering unit, the orthographic projections of the plurality of scattering particles on the substrate are distributed in concentric circles with the central projection as the center.

[0012] Optionally, in the orthographic projection of the plurality of scattering particles on the substrate, the distances between adjacent concentric circles decrease successively along a direction from close to the central projection to far away from the central projection.

[0013] Optionally, in the scattering unit, a plurality of scattering particles whose orthographic projections on the substrate are located on the same circular ring are distributed at equal intervals.

[0014] Optionally, one side of the substrate includes a plurality of openings with different depths and sizes, and the scattering particles are arranged in corresponding openings.

[0015] Optionally, in the scattering unit, the refractive index of the multiple scattering particles is the same.

[0016] Optionally, the scattering structure includes a plurality of scattering units stacked;

[0017] Along the light emitting direction of the light emitting unit, the refractive index of the scattering particles of the plurality of scattering units increases successively.

[0018] Optionally, the scattering structure includes a plurality of scattering units stacked;

[0019] Along the light emitting direction of the light emitting unit, the refractive index of the matrix of the plurality of scattering units increases successively.

[0020] Optionally, the display panel further includes a plurality of reflecting portions and a plurality of defining portions, wherein the defining portions are arranged between adjacent light-emitting units; and the reflecting portion is arranged on at least one side where the defining portions are in contact with the light-emitting units.

[0021] Optionally, the light-emitting unit includes a quantum dot light-emitting layer.

[0022] Optionally, the plurality of light emitting units are configured to emit light of the same initial wavelength band;

[0023] The display panel further includes a plurality of quantum dot color conversion units, which are disposed on the light-emitting side of the light-emitting unit and configured to convert the incident initial wavelength band light into target wavelength band light.

[0024] Optionally, the display panel further includes a plurality of transmission units, each of which is provided on a light-emitting side of the light-emitting unit and configured not to change the wavelength of the incident light of the initial wavelength band;

[0025] Wherein, the quantum dot color conversion unit and the transmission unit are respectively arranged corresponding to different light-emitting units.

[0026] Optionally, the quantum dot color conversion unit and the transmission unit are respectively arranged between the corresponding light-emitting unit and the scattering structure.

[0027] Optionally, the scattering structure includes a plurality of scattering units stacked;

[0028] Along the light emitting direction of the light emitting unit, the refractive index of the matrix of the plurality of scattering units increases successively.

[0029] Optionally, the quantum dot color conversion unit and the transmission unit are respectively configured to also serve as the matrix of the corresponding scattering structure; the scattering particles are respectively arranged on the side of the quantum dot color conversion unit and the transmission unit away from the light-emitting unit.

[0030] Optionally, among the plurality of light-emitting units, any one of some of the light-emitting units is correspondingly provided with a plurality of the quantum dot color conversion units, and any one of the remaining light-emitting units is correspondingly provided with a plurality of the transmission units;

[0031] The scattering particles are disposed on a side of each of the quantum dot color conversion units and each of the transmission units away from the light-emitting unit;

[0032] Along the light emitting direction of the light emitting unit, the refractive index of the plurality of quantum dot color conversion units corresponding to the same light emitting unit is the same, and the refractive index of the plurality of transmission units corresponding to the same light emitting unit is the same.

[0033] On the other hand, a display device is provided, comprising the above-mentioned display panel.

[0034] In another aspect, a method for preparing the above display panel is provided, the method comprising:

[0035] forming a plurality of light-emitting units;

[0036] A plurality of scattering structures are formed; wherein the scattering structure is arranged on the light-emitting side of the light-emitting unit and includes at least one scattering unit, the scattering unit includes a matrix and a plurality of scattering particles arranged on one side of the matrix, the particle size of the scattering particles and the distance between the orthographic projection and the central projection of the scattering particles on the substrate satisfy a positive correlation, and the central projection is the orthographic projection of the center of the light-emitting unit on the substrate.

[0037] Optionally, one side of the substrate includes a plurality of openings of different depths, and the scattering particles are arranged in corresponding openings;

[0038] The forming of a plurality of scattering structures comprises:

[0039] Formation of matrix membrane;

[0040] ablating one side surface of the matrix film by laser interference to form the matrix having a plurality of openings of different depths and sizes;

[0041] The scattering particles are sputtered into the opening.

[0042] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0044] Figure 1 The light emission diagram of the quantum dot is schematically shown;

[0045] Figure 2 Schematically shows a light path diagram after a light ray passes through a scattering unit;

[0046] Figure 3-6 Schematically shows the structures of four display panels;

[0047] Figure 7 Schematically shows a structural diagram of a scattering particle;

[0048] Figure 8 for Figure 7 Cross-section along AA direction;

[0049] Figure 9 Schematically shows a structural diagram of a matrix of a scattering unit;

[0050] Figure 10 A schematic structural diagram of a scattering structure is schematically shown;

[0051] Figure 11 for Figure 7 Another cross-sectional view along the AA direction;

[0052] Figure 12 Schematically shows a structural diagram of another scattering structure;

[0053] Figure 13 and Figure 14 Schematically shows the structures of two other display panels;

[0054] Figure 15 A test result diagram is schematically shown. DETAILED DESCRIPTION

[0055] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0056] In the embodiments of the present application, the same items or similar items with basically same functions and effects are distinguished by using "first", "second" and the like, only for clearly describing the technical solutions of the embodiments of the present application, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. In addition, the meaning of "multiple" is two or more than two, and the meaning of "at least one" is one or more than one, unless otherwise explicitly and specifically limited.

[0057] The embodiments of the present application provide a display panel, referring to Figure 3-6 as shown, comprising:

[0058] A substrate 11; the material of the substrate is not limited, for example, the material of the substrate can be rigid, such as glass; or can also be flexible, such as polyimide (PI) and the like.

[0059] A plurality of light emitting units 1 arranged in an array on the substrate 11.

[0060] A plurality of scattering structures (not labeled) arranged in an array. Figure 3-6 The scattering structure is arranged on the light emitting side of the light emitting unit 1 and comprises at least one scattering unit 21, the scattering unit 21 comprises a matrix 22 and a plurality of scattering particles 23 arranged on one side of the matrix 22, in combination with Figure 7 as shown, the particle size D of the scattering particle and the distance L1 between the orthographic projection of the scattering particle on the substrate 11 and the central projection O2 satisfy a positive correlation relationship, and the central projection O2 is the orthographic projection of the center O1 of the light emitting unit 1 on the substrate 11.

[0061] In order to define a plurality of light emitting units, the above display panel can further comprise a plurality of defining parts 3, and an opening area is arranged between adjacent defining parts 3, and the above light emitting unit 1 is arranged in the opening area; the specific structure of the light emitting unit is not limited, for example, the light emitting unit can comprise a first electrode, a light emitting layer and a second electrode. The center of the light emitting unit can be selected according to the structure. For example, the center of the light emitting unit can be the center of the light emitting layer, or referring to Figure 3-6As shown, the center of the light-emitting unit can also be the center O1 of the opening area. The shape and size of the opening area directly affect the shape and size of the light-emitting unit, and thus the shape and size of the sub-pixel. The shape of the cross section of the opening area parallel to the substrate is not limited here, and examples thereof may be rectangular, diamond, or elliptical. In addition, the shape of the cross section of the opening area perpendicular to the substrate is not limited here, and examples thereof may be rectangular or trapezoidal.

[0062] For the sake of convenience, the distance between the orthographic projection and the central projection of the scattering particles on the substrate is called the first distance; the positive correlation between the particle size of the scattering particles and the first distance means: Figure 7 As shown, the particle size D of the scattering particles increases as the first distance L1 increases, or the particle size of the scattering particles decreases as the first distance decreases; then the particle size gradient of the particles decreases from the edge position to the center position, and the particle size of the scattering particles corresponding to the center area of ​​the light-emitting unit (such as the scattering particles marked as S1 in the figure) is smaller than the particle size of the scattering particles corresponding to the edge area of ​​the light-emitting unit (such as the scattering particles marked as S4 in the figure), that is, the particle size of the edge particles is large and the particle size of the center particles is small.

[0063] The size of the above-mentioned scattering particles is at the nanometer level, so they can also be called nano-scattering particles. The particle size range can be 30nm-180nm. The scattering of light by nano-scattering particles belongs to Rayleigh scattering. According to the Rayleigh scattering model, at the nanometer scale, the larger the particle radius, the stronger the Rayleigh scattering effect. In the display panel provided by the present application, the particle size of the scattering particles satisfies a positive correlation with the first distance. The particle size of the scattering particles corresponding to the central area of ​​the light-emitting unit is small (for example, the particle size is 30nm), and the scattering effect is weak, which facilitates direct transmission of light; the particle size of the scattering particles corresponding to the edge area of ​​the light-emitting unit is large (for example, the particle size is 180nm), and the scattering effect is strong, which is conducive to the convergence of light to the center, thereby improving the light output rate and the positive viewing angle luminescence.

[0064] The scattering particles may be made of an inorganic material, such as any one or a combination of silicon dioxide, titanium dioxide, zirconium dioxide, vanadium dioxide, tin dioxide, aluminum oxide, or barium titanate; or an organic material, such as any one or a combination of silicone, polystyrene, or polycarbonate. This is not a limitation and may be selected based on actual requirements.

[0065] The shape of the scattering particles is not limited. For example, the scattering particles can be spherical, ellipsoidal, or cubic. To facilitate the analysis of scattering paths and reduce the difficulty of design and production, spherical scattering particles can be used. The drawings of the embodiments of this application are all drawn using spherical scattering particles as an example. When the scattering particles are spherical, the particle size of the scattering particles refers to the diameter; if the scattering particles are shaped differently, the particle size of the scattering particles can refer to the size of the scattering particles.

[0066] In some embodiments, the scattering particles are hollow particles. These hollow particles can be spherical and have a core-shell structure, specifically comprising a core and a shell. As the diameter of the hollow particle increases, the amount of gas layer filling the core increases, and the refractive index of the scattering unit filled with the hollow particle decreases.

[0067] The matrix can be made of a transmissive material, for example, an amorphous material that can be evaporated; other transmissive materials are also possible and are not limited here. The thickness of the matrix in the direction perpendicular to the substrate is not limited and is generally in the micrometer range.

[0068] The structure of the light-emitting unit is not limited. For example, the light-emitting unit may include a light-emitting layer. The material of the light-emitting layer is not limited here and may be an organic light-emitting material or a quantum dot material. To improve the luminous efficiency, the light-emitting unit may also include an electron transport layer and a hole transport layer located on both sides of the light-emitting layer. To further improve the injection efficiency of electrons and holes, the light-emitting unit may also include an electron injection layer located on the side of the electron transport layer away from the light-emitting layer, and a hole injection layer located on the side of the hole transport layer away from the light-emitting layer. The light-emitting unit may emit blue light, or may also emit UV light, etc., which is not limited here.

[0069] The above display panel can be applied to Figure 3 and Figure 4 The QLED display panel shown, in this case, the above-mentioned light-emitting unit may include a quantum dot light-emitting layer. Quantum dots (QD) are nanocrystalline particles whose radius is smaller than or close to the exciton Bohr radius, and usually have a particle size between 1nm and 20nm. Quantum dots have a quantum confinement effect and emit fluorescence when excited. Quantum dots have unique luminescence properties, such as: a wide excitation peak width, a narrow emission peak and an adjustable luminescence spectrum. By adjusting the size of the quantum dots, a high-purity spectrum of different colors can be obtained. In addition, quantum dots are inorganic substances, have a more stable working state, a longer life, and a lower cost. However, reference Figure 1 As shown, the light output angle of the electroluminescent layer (EL) is dispersed, the photon extraction rate and the luminous intensity at the positive viewing angle need to be further optimized. Figure 2 As shown, the photon extraction rate and the luminous intensity at the positive viewing angle can be greatly improved.

[0070] Alternatively, the display panel can also be applied to Figure 5 and Figure 6 The QD-OLED display panel shown in the figure, in this case, the above-mentioned light-emitting unit may include a blue light organic light-emitting layer, and the above-mentioned display panel may also include a quantum dot color conversion layer. The QD-OLED display panel combines blue light OLED (Organic Light-Emtting Diode) and QD (Quantum Dot). The blue light emitted by the blue light organic light-emitting layer can obtain red light or green light after passing through the quantum dot color conversion layer, thereby realizing color display.

[0071] The manufacturing process of the display panel is not limited. For example, the display panel can be formed by a cell-to-cell process (for example Figure 4 and Figure 6 The display panel shown in FIG. 1 may further include a substrate, wherein the substrate and the substrate are arranged opposite to each other. Figure 4 and Figure 6 As shown, a light-emitting unit 1 and other film layers can be fabricated on a substrate 11 to form a first substrate, and a black matrix 14, a color filter layer (including a color filter unit 15), and a plurality of scattering structures (including a scattering unit 21) and other film layers can be fabricated on a base 12 in sequence to form a second substrate. The first substrate and the second substrate are then assembled to form a display panel. Alternatively, the display panel can also be formed using an On-EL process (e.g. Figure 3 and Figure 5 For details, refer to the display panel shown in Figure 3 and Figure 5 As shown, the light-emitting unit 1, multiple scattering structures (including the scattering unit 21), the black matrix 14, the color film layer (including the color film unit 15) and other film layers can be manufactured in sequence on the substrate 11, and then the base 12 is used to form a cover plate to form a display panel.

[0072] It should be noted that the above display panel may also include Figure 3-6 The black matrix 14 and the color filter layer (including the color filter unit 15) and other structures shown here only introduce the structures related to the invention points, and other structures are not described in detail.

[0073] In the display panel provided by the present application, the particle size distribution of the scattering particles is adjusted so that the particle size gradient of the particles decreases from the edge position to the center position, and the particle size of the scattering particles corresponding to the center area of ​​the light-emitting unit is smaller than the particle size of the scattering particles corresponding to the edge area of ​​the light-emitting unit; in this way, the particle size of the scattering particles corresponding to the center area of ​​the light-emitting unit is small, and the scattering effect is weak, thereby facilitating direct light transmission; the particle size of the scattering particles corresponding to the edge area of ​​the light-emitting unit is large, and the scattering effect is strong, referring to Figure 2As shown, this helps light converge toward the center, thereby improving light extraction efficiency and luminescence at a normal viewing angle. In addition, the scattering unit includes a matrix and a plurality of scattering particles disposed on one side of the matrix, so that the surface of the scattering unit on the side where the scattering particles are disposed is uneven, thereby disrupting the flatness of the film layer and reducing the probability of specular reflection, thereby further improving light extraction efficiency.

[0074] Optionally, the particle size of the scattering particles is D, the distance between the orthographic projection and the central projection of the scattering particles on the substrate is x, and D and x satisfy:

[0075]

[0076] Where f(x, D) is the particle distribution density function.

[0077] The distribution density of the scattering particles satisfies f(x, D), and the distribution density of the scattering particles in the edge area of ​​the corresponding light-emitting unit is greater than the distribution density of the scattering particles in the center area of ​​the corresponding light-emitting unit; then, reference Figure 7 As shown, the distribution density of the scattering particles corresponding to the central area of ​​the light-emitting unit is low, and the particle size is small, so there is no obvious effect on the light emission at the front angle; while the distribution density of the scattering particles corresponding to the edge area of ​​the light-emitting unit is high, and the particle size is large, which has a strong scattering effect on the light at the side angle. Therefore, more than 30% of the light at the side angle will enter the light emission path at the front angle, thereby further improving the brightness of the light emission at the front angle.

[0078] The green light monochrome QLED device is used as a simulation sample, and the device structure is referenced Figure 3 As shown, the material of the scattering particles is titanium dioxide, and the particle size distribution density satisfies f(x, D). After simulation testing, we can get the following Figure 15 The test pattern shown. Figure 15 In the figure, the horizontal axis represents the view angle (degrees); the vertical axis represents the normalized light intensity. Furthermore, the structure corresponding to the experimental example is equipped with a scattering structure, while the structure corresponding to the control example is not equipped with a scattering structure. By comparison, it can be found that the view angle of the experimental example is greater than that of the control example, indicating that the light extraction efficiency of the device has been effectively improved.

[0079] It should be noted that, according to the conditions of different sub-pixels, the distribution density of the scattering particles can be further optimized, thereby obtaining a distribution density function different from f(x, D).

[0080] Optionally, to further improve light output, refer to Figure 7 As shown, in the scattering unit, the orthographic projections of a plurality of scattering particles on the substrate 11 are distributed in concentric circles with the central projection O2 as the center.

[0081] refer to Figure 7As shown, the particle sizes of multiple scattering particles located in the same circle are the same. In addition, the closer to the center, the smaller the particle size of the scattering particles and the lower the distribution density; the farther away from the center, the larger the particle size of the scattering particles and the higher the distribution density. Figure 7 Four concentric circles are used as an example for illustration. Components belonging to the same ring are marked with the same letter, and the scattered particles on the four rings are labeled S1, S2, S3, and S4 respectively.

[0082] In one or more embodiments, in order to ensure that the density of the scattering particles close to the center is less than the density of the scattering particles far from the center, reference Figure 7 and Figure 8 As shown in FIG, in the orthographic projection of multiple scattering particles on the substrate, the distance between adjacent concentric circles decreases in sequence from the projection close to the center to the projection far away from the center. Figure 8 In the equation, D3 is smaller than D2, D2 is smaller than D1; d4 is larger than d3, d3 is larger than d2, and d2 is larger than d1.

[0083] In one or more embodiments, in order to improve the uniformity of light output and further improve the light output efficiency, in the scattering unit, multiple scattering particles whose orthographic projections on the substrate are located in the same ring are distributed at equal intervals, referring to Figure 7 As shown, on the same ring, the L2 of adjacent scattering particles are the same.

[0084] In one or more embodiments, in combination Figure 8 and Figure 9 As shown, one side of the matrix 22 includes a plurality of openings 220 with different depths ( H1 ) and different sizes ( L1 ), and the scattering particles 23 are disposed in corresponding openings 220 .

[0085] In the scattering unit, the scattering particles are embedded in the surface openings of the matrix, so that the distribution of the scattering particles can be controlled by controlling the distribution of the openings, which has higher controllability and is easy to implement.

[0086] Of course, the specific structure of the matrix and scattering particles in the scattering unit is not limited thereto. Figure 11 As shown, the scattering particles 23 can also be directly set on one side of the matrix 22, and the matrix does not need to be provided with openings; under this structure, in order to better fix the scattering particles, the scattering unit also needs to be provided with a fixing unit; there is no limitation on the fixing unit here, and the fixing unit can fix the scattering particles based on magnetic adsorption or electrical adsorption, and the specific structure can be obtained in combination with relevant technologies.

[0087] In one or more embodiments, in the scattering unit, the refractive index of the multiple scattering particles is the same; thus, the multiple scattering particles can be made of the same material, thereby simplifying the manufacturing process and reducing the manufacturing cost; at the same time, it is beneficial to the optical path design.

[0088] Optional, reference Figure 10 and Figure 12 As shown, the scattering structure 2 includes a plurality of scattering units 21 arranged in a stacked manner; along the light emitting direction of the light emitting unit, the refractive indices of the scattering particles 23 of the plurality of scattering units 21 increase in sequence.

[0089] That is, within the same scattering unit, the refractive index of multiple scattering particles is the same; for multiple scattering units arranged in layers, the closer to the light-emitting unit, the smaller the refractive index of the scattering particles, and the farther away from the light-emitting unit, the larger the refractive index of the scattering particles; this is further conducive to converging the light to the center and further improving the light output efficiency.

[0090] In one or more embodiments, reference Figure 10 and Figure 12 As shown, the scattering structure 2 includes a plurality of scattering units 21 arranged in a stacked manner; along the light emitting direction of the light emitting unit, the refractive index of the matrix 22 of the plurality of scattering units 21 increases successively.

[0091] That is, for multiple scattering units stacked together, the closer the scattering units are to the light-emitting unit, the smaller the refractive index of the matrix is, and the farther the scattering units are from the light-emitting unit, the larger the refractive index of the matrix is; this is further beneficial for converging the light to the center and further improving the light extraction efficiency.

[0092] In one or more embodiments, reference Figure 3-6 As shown, the display panel further includes a plurality of reflecting portions 4 and a plurality of defining portions 3 . The defining portions 3 are arranged between adjacent light emitting units 1 . The reflecting portion 4 is arranged on at least one side where the defining portion 3 contacts the light emitting unit 1 .

[0093] The above-mentioned limiting portion can prevent adjacent light-emitting units from interfering with each other, thereby reducing the risk of cross-color and improving display contrast. The cross-sectional shape of the limiting portion along the direction perpendicular to the substrate can be a right trapezoid, an inverted trapezoid, or a rectangle, etc. The drawings of the embodiments of this application all use a right trapezoid as an example.

[0094] The larger the setting area of ​​the above-mentioned reflective portion, the better the reflection effect. The reflective portion is arranged on at least one side of the limiting portion and the light-emitting unit in contact with each other, including: the reflective portion is arranged on the side of the limiting portion and the light-emitting unit in contact with each other; or, referring to Figure 3-6 As shown, the reflective portion is provided on at least two sides where the limiting portion contacts the light emitting unit; or, the reflective portion is provided on all sides where the limiting portion contacts the light emitting unit; this is not limited here and can be selected according to actual conditions.

[0095] The material of the reflective portion is not limited, and its reflectivity can be set to be above 80% (for example, 80%-95%). When light from the light-emitting unit is directed toward the reflective portion, it is reflected back into the light-emitting unit, thereby changing the path of the light directed toward the reflective portion, extending the optical path of the light, and thus improving the utilization rate of the light.

[0096] In one or more embodiments, reference Figure 3 and Figure 4 As shown, the light emitting unit 1 includes a quantum dot light emitting layer (not shown), and the display panel can be applied to a QLED display panel. The structure of the QLED display panel can refer to Figure 3 and Figure 4 As shown, of course, the panel may also include structures such as a black matrix and a color filter layer.

[0097] In one or more embodiments, reference Figure 5 and Figure 6 As shown, multiple light-emitting units are configured to emit light of the same initial wavelength band; the display panel also includes multiple quantum dot color conversion units 5, which are arranged on the light-emitting side of the light-emitting unit 1 and are configured to convert the incident initial wavelength band light into target wavelength band light.

[0098] The specific wavelengths of the above-mentioned initial wavelength band light and target wavelength band light are not limited. For example, the wavelength of the initial wavelength band light can be 450-480nm, and the light in this wavelength band is blue light; the wavelength of the target wavelength band light can be 622-760nm, and the light in this wavelength band is red light; or, the wavelength of the target wavelength band light can also be 500-560nm, and the light in this wavelength band is green light. The above-mentioned multiple quantum dot color conversion units can be to convert the initial wavelength band light into the same target wavelength band light; or, the multiple quantum dot color conversion units can also be to convert the initial wavelength band light into different target wavelength band lights. For example, the multiple quantum dot color conversion units are divided into two groups, one group converts the initial wavelength band light into one target wavelength band light (for example, red light), and the other group converts the initial wavelength band light into another target wavelength band light (for example, green light). In QD-OLED display panels, red light band and green light band are generally selected as target band light, blue light band is used as initial band light, and multiple quantum dot color conversion units are divided into red conversion unit and green conversion unit. The red conversion unit is configured to convert the blue light band into the red light band (that is, convert blue light into red light), and the green conversion unit is configured to convert the blue light band into the green light band (that is, convert blue light into green light). Figure 5 and Figure 6 In the figure, the quantum dot color conversion unit on the left is a red conversion unit, and the quantum dot color conversion unit on the right is a green conversion unit.

[0099] There is no limitation on the relative positional relationship between the quantum dot color conversion unit and the scattering structure. For example, the scattering structure may be provided only on the side of the quantum dot color conversion unit away from the light-emitting unit; or, the scattering structure may be provided only on the side of the quantum dot color conversion unit close to the light-emitting unit; or, the scattering structure may be provided respectively on the side of the quantum dot color conversion unit away from the light-emitting unit and on the side of the quantum dot color conversion unit close to the light-emitting unit.

[0100] This display panel can be applied to a panel that combines OLED and QD, combining the advantages of both OLED and QD; this application can improve the light output rate of this type of display panel by setting a scattering structure.

[0101] Further optional, refer to Figure 5 and Figure 6 As shown, the display panel also includes a plurality of transmission units 6, which are arranged on the light-emitting side of the light-emitting unit 1 and are configured not to change the wavelength of the incident initial wavelength band light; wherein the quantum dot color conversion unit 5 and the transmission unit 6 are respectively arranged corresponding to different light-emitting units.

[0102] The above-mentioned transmission unit can be transmissive to the incident light without band conversion. For example, if the initial band light is blue light, the blue light can pass through the transmission unit and will not be converted into light of other bands such as red light, and can be directly used for blue display. The transmission unit can be a light diffusion unit, so that the incident light is scattered without changing the wavelength, which is conducive to uniform display. The light diffusion unit can be made of a light diffusion resin or a transmissive resin with light diffusion ability, so that the incident light is more uniform after passing through it. In this application, transmission means allowing light to be transmitted while changing the angle but without band conversion. Of course, the transmission unit can also modulate the depth of the color of the incident light. For example, if the incident light is dark blue, it will be converted into light blue after being modulated by the transmission unit. The wavelengths of the incident light and the converted light both belong to the blue light band.

[0103] The following provides a specific structure of a quantum dot color conversion unit, a transmission unit and a scattering structure.

[0104] refer to Figure 5 and Figure 6 As shown, the quantum dot color conversion unit 5 and the transmission unit 6 are respectively arranged between the corresponding light-emitting unit 1 and the scattering structure (including the scattering unit 21).

[0105] In this way, the initial wavelength band light emitted by the light-emitting unit is converted by the quantum dot color conversion unit or the transmission unit and then emitted to the scattering structure. After passing through the quantum dot color conversion unit or the transmission unit, the light output angle is relatively dispersed, and the light extraction efficiency is low. By providing a scattering structure, the light emitted from the quantum dot color conversion unit or the transmission unit is modulated, so that the light is concentrated as much as possible towards the center, thereby improving the light extraction efficiency and the emission angle of the light at the right angle.

[0106] Further optional, refer to Figure 10 As shown, the scattering structure 2 includes a plurality of scattering units 21 arranged in a stacked manner; along the light emitting direction of the light emitting unit, the refractive index of the matrix 22 of the plurality of scattering units 21 increases successively.

[0107] In this way, the matrix of multiple scattering units can also modulate the incident light, which can further make more light converge to the center, thereby further improving the light output rate and the positive viewing angle of light.

[0108] The following provides another specific structure of the quantum dot color conversion unit, the transmission unit and the scattering structure.

[0109] refer to Figure 13 and Figure 14 As shown, the quantum dot color conversion unit 5 and the transmission unit 6 are respectively configured to also serve as the matrix of the corresponding scattering structure; scattering particles 23 are respectively set on the side of the quantum dot color conversion unit 5 and the transmission unit 6 away from the light-emitting unit 1.

[0110] Then, the quantum dot color conversion unit and the corresponding scattering particles are integrated together, and the transmission unit and the corresponding scattering particles are integrated together, so there is no need to set up an additional matrix, which is beneficial to saving materials and costs; at the same time, the scattering particles can modulate the light emitted from the quantum dot color conversion unit or the transmission unit, so that the light is concentrated to the center as much as possible, thereby improving the light output rate and the positive viewing angle luminescence.

[0111] Further optional, refer to Figure 14 As shown, in order to further improve the light extraction efficiency, among the multiple light-emitting units, any one of some light-emitting units 1 is correspondingly provided with multiple quantum dot color conversion units 5, and any one of the remaining light-emitting units 1 is correspondingly provided with multiple transmission units 6.

[0112] refer to Figure 14 As shown, scattering particles 23 are provided on the side of each quantum dot color conversion unit 5 and each transmission unit 6 away from the light-emitting unit 1. Along the light-emitting direction of the light-emitting unit, the refractive index of the multiple quantum dot color conversion units corresponding to the same light-emitting unit is the same, and the refractive index of the multiple transmission units corresponding to the same light-emitting unit is the same.

[0113] The initial wavelength light emitted from the light-emitting unit is converted by the quantum dot color conversion unit or the transmission unit and then emitted to the scattering particles. After the light is modulated once by the scattering particles, it enters the quantum dot color conversion unit or the transmission unit again. Then, it is emitted to the scattering particles again for a second modulation. This process is repeated, so that the light undergoes multiple modulations, ultimately significantly improving the light extraction efficiency. It should be noted that in order to modulate the light emitted by the quantum dot color conversion unit and the transmission unit, the scattering particles are arranged on the side of the quantum dot color conversion unit and the transmission unit away from the light-emitting unit. Therefore, this structure is more suitable for application in display panels formed using the On-EL process.

[0114] refer to Figure 3-6 As shown, the display panel also includes a color film layer (including a color film unit 15), which is located between the scattering structure and the substrate. The color film layer includes multiple color film units 15, and the color film unit 15 is configured to transmit the target band light emitted by the scattering unit and absorb non-target band light.

[0115] The color filter unit can be a red color filter unit that transmits red light and absorbs light of other wavelengths; or a green color filter unit that transmits green light and absorbs light of other wavelengths; or a blue color filter unit that transmits blue light and absorbs light of other wavelengths. To achieve color display, the multiple color filter units can include red, green, and blue color filter units.

[0116] It should be noted that if the display panel is applied to a QD-OLED display panel, the display panel also includes multiple quantum dot color conversion units and multiple transmission units. If the multiple quantum dot color conversion units are divided into red conversion units and green conversion units, and the multiple transmission units are blue conversion units, then the red conversion unit corresponds to the red color film unit, the green conversion unit corresponds to the green color film unit, and the blue conversion unit corresponds to the blue color film unit.

[0117] The following provides a display panel formed by a cell-to-cell process. Figure 6 As shown, the manufacturing process of the display panel may include: forming a light-emitting unit 1 on a substrate 11 to form a first substrate, sequentially forming a black matrix 14, a color filter layer (including a color filter unit 15), a scattering structure (including a scattering unit 21), a quantum dot color conversion unit 5 and a transmission unit 6 on a base 12 to form a second substrate, and then assembling the first substrate and the second substrate to form a cell as shown in FIG. Figure 6 The display panel is shown. Of course, reference Figure 6As shown, the display panel includes a substrate 11, and a reflective electrode 10, a thin film transistor 9, a light-emitting unit 1, a limiting portion 3, a reflecting portion 4 and an encapsulation layer 17 arranged on the substrate 11. The display panel also includes a base 12, and a black matrix 14, a color filter layer (including a color filter unit 15), a flat film 13, a spacer 20, a limiting unit 7, and a reflecting unit 8 arranged on the base 12; the display panel also includes a first filling layer 19, a second filling layer 30 and a dam 31. Among them, the flat film can also play a role in encapsulation. The flat film can be used to prepare low-stress, dense inorganic thin films such as SiO through ultra-low temperature processes (≤100°C). x 、SiN x , Al2O3 thin film, etc. The thickness of the flat film is less than 1 μm, for example, less than 0.5 μm, and the refractive index ranges from 1.7 to 2.0, for example, from 1.75 to 1.85.

[0118] The following provides a display panel formed using the On-EL process. Figure 5 As shown, the manufacturing process of the display panel may include: sequentially manufacturing the light-emitting unit 1, the quantum dot color conversion unit 5, the scattering structure (including the scattering unit 21), the black matrix 14, the color filter layer (including the color filter unit 15) and the base 12 (used as a cover plate) on the substrate 11, thereby forming a display panel as shown in FIG. Figure 5 The display panel shown. Of course, refer to Figure 5 As shown, the display panel further includes a defining portion 3 and a reflecting portion 4, and the light-emitting unit 1 is arranged in an opening formed by an adjacent defining portion 3; the display panel further includes an encapsulation layer 17, a reflective polarizer 16, a reflecting electrode 10, a thin film transistor 9, a flat film 13, etc.; the flat film can also play a packaging role, and the flat film can be prepared by an ultra-low temperature process (≤100°C) to form a low-stress, dense inorganic thin film, such as SiO x 、SiN x , Al2O3 thin film, etc. The thickness of the flat film 102 is less than 1 μm, for example, less than 0.5 μm, and the refractive index ranges from 1.7 to 2.0, for example, from 1.75 to 1.85.

[0119] The embodiments of the present application further provide a display device, including the above-mentioned display panel. The display device can be a rigid display device or a flexible display device (i.e., bendable or foldable), which is not limited here. At the same time, its type can be a QLED display panel, or it can also be a QD-OLED display panel, as well as any product or component with a display function such as a TV, digital camera, mobile phone, tablet computer, etc. that includes these display panels. The display device has a high light output rate, strong luminescence at a positive viewing angle, and good display effect.

[0120] An embodiment of the present application further provides a method for preparing the display panel as described above, the method comprising:

[0121] S01. Form a plurality of light-emitting units.

[0122] S02. Form multiple scattering structures; wherein the scattering structure is arranged on the light-emitting side of the light-emitting unit and includes at least one scattering unit, the scattering unit includes a matrix and a plurality of scattering particles arranged on one side of the matrix, the particle size of the scattering particles and the distance between the orthographic projection and the central projection of the scattering particles on the substrate satisfy a positive correlation, and the central projection is the orthographic projection of the center of the light-emitting unit on the substrate.

[0123] The forming methods of the above-mentioned step S01 and step S02 are not limited and can be specifically determined according to the specific structures of the light-emitting unit and the scattering structure.

[0124] The following describes a method for preparing a scattering unit in which scattering particles are embedded in a substrate.

[0125] Optionally, one side of the substrate includes a plurality of openings with different depths, and the scattering particles are arranged in corresponding openings.

[0126] S02. Forming a plurality of scattering structures includes:

[0127] S021. Forming a matrix membrane.

[0128] The material of the matrix film can be a transmissive thin film material that can be evaporated. For example, the matrix material can be evaporated to a preset position using an FMM (Fine Metal Mask).

[0129] S022. A surface of one side of the matrix film is ablated by using laser interference to form a matrix having a plurality of openings of different depths and sizes.

[0130] The patterned matrix is ​​prepared using a laser interference ablation method. Specifically, a high-energy laser can be used to form an interference laser through an interference system. The laser interference system is built according to the expected pattern and period. The interference light source acts on the surface of the matrix to ablate a periodic cross-scale micro / nanostructure pattern. The nanostructure is an array of multiple recessed structures (i.e., multiple openings are formed); each recessed structure corresponds to a subsequently deposited nanoscattering particle. The diameter and depth of the recessed structure can be adjusted by adjusting the energy and action time of the laser, thereby forming multiple openings of different depths and sizes. Among them, the characteristic size of the interference pattern is controllable at 1-10μm, and the characteristic size of the nanoscattering particles is controllable at 20-200nm.

[0131] S023. Sputtering scattering particles into the opening.

[0132] A patterned scattering particle layer is prepared by magnetron sputtering. Specifically, step S022 is used to select scattering particles of different sizes by changing the diameter and depth of these recessed structures (i.e., openings). Recessed structures of different sizes will select scattering particles of corresponding sizes; if the sizes of the two match, the scattering particles can be embedded in the openings of the matrix and fixed on the surface of the matrix, thereby forming a patterned scattering particle layer.

[0133] By repeating S021 to S023 multiple times, a plurality of scattering units arranged in a stacked manner can be formed.

[0134] References herein to "one embodiment," "an embodiment," or "one or more embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. Furthermore, please note that instances of the phrase "in one embodiment" do not necessarily all refer to the same embodiment.

[0135] In the description provided herein, a large number of specific details are described. However, it is understood that the embodiments of the present application can be practiced without these specific details. In some instances, well-known methods, structures, and techniques are not shown in detail so as not to obscure the understanding of this description.

[0136] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A display panel, wherein: include: substrate; A plurality of light-emitting units arranged in an array on the substrate; Multiple scattering structures arranged in an array; The scattering structure is arranged on the light-emitting side of the light-emitting unit and includes at least one scattering unit. The scattering unit includes a matrix and a plurality of scattering particles arranged on one side of the matrix. The particle size of the scattering particles and the distance between the orthographic projection and the central projection of the scattering particles on the substrate are positively correlated. The central projection is the orthographic projection of the center of the light-emitting unit on the substrate.

2. The display panel according to claim 1, wherein The particle size of the scattering particles is D, the distance between the orthographic projection of the scattering particles on the substrate and the central projection is x, and D and x satisfy: Where f(x, D) is the particle distribution density function.

3. The display panel according to claim 1, wherein: In the scattering unit, the orthographic projections of the plurality of scattering particles on the substrate are distributed in concentric circles with the central projection as the center. 4 . The display panel according to claim 3 , wherein in the orthographic projection of the plurality of scattering particles on the substrate, the distance between adjacent concentric circles decreases in sequence along the direction from close to the center projection to far away from the center projection. 5 . The display panel according to claim 3 , wherein in the scattering unit, the plurality of scattering particles whose orthographic projections on the substrate are located in the same circular ring are distributed at equal intervals. The display panel according to claim 1 , wherein: One side of the substrate includes a plurality of openings with different depths and sizes, and the scattering particles are arranged in the corresponding openings.

7. The display panel according to claim 1, wherein: In the scattering unit, the refractive index of the plurality of scattering particles is the same.

8. The display panel according to claim 7, wherein: The scattering structure includes a plurality of scattering units stacked in layers; Along the light emitting direction of the light emitting unit, the refractive index of the scattering particles of the plurality of scattering units increases successively.

9. The display panel according to claim 1, wherein: The scattering structure includes a plurality of scattering units stacked in layers; Along the light emitting direction of the light emitting unit, the refractive index of the matrix of the plurality of scattering units increases successively.

10. The display panel according to claim 1, wherein The display panel further includes a plurality of reflecting portions and a plurality of defining portions, wherein the defining portions are arranged between adjacent light emitting units; and the reflecting portion is arranged on at least one side where the defining portion contacts the light emitting unit.

11. The display panel according to claim 1, wherein: The light-emitting unit includes a quantum dot light-emitting layer.

12. The display panel according to claim 1, wherein: The plurality of light emitting units are configured to emit light of the same initial wavelength band; The display panel further includes a plurality of quantum dot color conversion units, which are disposed on the light-emitting side of the light-emitting unit and configured to convert the incident initial wavelength band light into target wavelength band light.

13. The display panel according to claim 12, wherein: The display panel further includes a plurality of transmission units, each of which is disposed on a light-emitting side of the light-emitting unit and configured not to change the wavelength of the incident light of the initial wavelength band; Wherein, the quantum dot color conversion unit and the transmission unit are respectively arranged corresponding to different light-emitting units.

14. The display panel according to claim 13, wherein: The quantum dot color conversion unit and the transmission unit are respectively arranged between the corresponding light-emitting unit and the scattering structure.

15. The display panel according to claim 14, wherein: The scattering structure includes a plurality of scattering units stacked in layers; Along the light emitting direction of the light emitting unit, the refractive index of the matrix of the plurality of scattering units increases successively.

16. The display panel according to claim 13, wherein: The quantum dot color conversion unit and the transmission unit are respectively configured to also serve as the matrix of the corresponding scattering structure; the scattering particles are respectively arranged on a side of the quantum dot color conversion unit and the transmission unit away from the light-emitting unit.

17. The display panel according to claim 16, wherein: Among the plurality of light-emitting units, any one of some of the light-emitting units is correspondingly provided with a plurality of the quantum dot color conversion units, and any one of the remaining light-emitting units is correspondingly provided with a plurality of the transmission units; The scattering particles are disposed on a side of each of the quantum dot color conversion units and each of the transmission units away from the light-emitting unit; Along the light emitting direction of the light emitting unit, the refractive index of the plurality of quantum dot color conversion units corresponding to the same light emitting unit is the same, and the refractive index of the plurality of transmission units corresponding to the same light emitting unit is the same.

18. A display device, wherein: The display panel comprises the display panel according to any one of claims 1 to 17.

19. A method for preparing a display panel according to any one of claims 1 to 17, wherein: The method comprises: forming a plurality of light-emitting units; A plurality of scattering structures are formed; wherein the scattering structure is arranged on the light-emitting side of the light-emitting unit and includes at least one scattering unit, the scattering unit includes a matrix and a plurality of scattering particles arranged on one side of the matrix, the particle size of the scattering particles and the distance between the orthographic projection and the central projection of the scattering particles on the substrate satisfy a positive correlation, and the central projection is the orthographic projection of the center of the light-emitting unit on the substrate.

20. The method according to claim 19, wherein One side of the substrate includes a plurality of openings of different depths, and the scattering particles are arranged in the corresponding openings; The forming of a plurality of scattering structures comprises: Formation of matrix membrane; ablating one side surface of the matrix film by laser interference to form the matrix having a plurality of openings of different depths and sizes; The scattering particles are sputtered into the opening.

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