A display panel and display device

Abstract

This invention provides a display panel and a display device, including a substrate; a light-emitting structure layer located on one side of the substrate, including a plurality of light-emitting units emitting different colors of light; and an optical functional layer located on the side of the light-emitting structure layer opposite to the substrate, including at least two alternately arranged light extraction layers. Each light extraction layer includes a first light extraction layer or a second light extraction layer, wherein the refractive index of the first light extraction layer is greater than the refractive index of the second light extraction layer, and the refractive index difference between the first and second light extraction layers satisfies: 0 ≤ n1 - n2 ≤ 0.2 and 0 ≤ n3 - n1 ≤ 0.4. Wherein, n1 is the refractive index difference between the first and second light extraction layers in a first wavelength band, n2 is the refractive index difference between the first and second light extraction layers in a second wavelength band, and n3 is the refractive index difference between the first and second light extraction layers in a third wavelength band.

Description

Technical Field

[0001] This invention relates to the field of display technology, and more particularly to a display panel and a display device. Background Technology

[0002] OLED displays have become the mainstream display technology due to their wide color gamut, thinness, and flexibility. However, with the popularization and penetration of new technologies, such as 5G phones consuming 20% ​​more power than 4G phones, the display screen, as the most power-consuming component in a mobile phone, needs to continuously reduce power consumption. Therefore, improving the light extraction efficiency of OLED products and reducing power consumption has become the primary goal.

[0003] Currently, it is difficult to achieve significant power consumption improvement through iterative improvement of light-emitting layer materials. Therefore, optimizing the light extraction layer of the external microcavity structure has become a new breakthrough point for improving power consumption. Summary of the Invention

[0004] In view of the above problems, the present invention provides a display panel and a display device to solve the problem that the efficiency of red, green and blue light cannot be taken into account in the same multi-layer light extraction layer structure thickness setting.

[0005] To achieve the above objectives, the present invention provides a display panel, comprising a substrate; a light-emitting structure layer located on one side of the substrate, comprising a plurality of light-emitting units emitting different colors of light; and an optical functional layer located on the side of the light-emitting structure layer opposite to the substrate, comprising at least two alternately arranged light extraction layers; the light extraction layer comprises a first light extraction layer or a second light extraction layer, wherein the refractive index of the first light extraction layer is greater than the refractive index of the second light extraction layer, and the refractive index difference between the first light extraction layer and the second light extraction layer satisfies: 0 ≤ n1 - n2 ≤ 0.2 and 0 ≤ n3 - n1 ≤ 0.4. Wherein, n1 is the refractive index difference between the first light extraction layer and the second light extraction layer in a first wavelength band, n2 is the refractive index difference between the first light extraction layer and the second light extraction layer in a second wavelength band, and n3 is the refractive index difference between the first light extraction layer and the second light extraction layer in a third wavelength band.

[0006] Furthermore, the refractive index of the first light extraction layer is greater than or equal to 1.8, and the refractive index of the second light extraction layer is less than 1.8.

[0007] Furthermore, the refractive index difference between the first light extraction layer and the second light extraction layer satisfies: 0≤n1-n2≤0.15 and 0≤n3-n1≤0.25 Furthermore, the refractive index of the first light extraction layer has a difference between 0 and 0.2 in the first and second wavebands, and a difference between 0 and 0.4 in the first and third wavebands; the refractive index of the second light extraction layer has a difference between 0 and 0.1 in the first and second wavebands, and a difference between 0 and 0.2 in the first and third wavebands.

[0008] Furthermore, the optical functional layer includes a first light extraction layer and a second light extraction layer; the first light extraction layer is located on the side of the second light extraction layer that faces away from the substrate. Alternatively, the second light extraction layer is located on the side of the first light extraction layer that is away from the substrate.

[0009] Furthermore, the optical functional layer includes two first light extraction layers and one second light extraction layer, with the second light extraction layer located between the two first light extraction layers; Alternatively, the display panel includes two second light extraction layers and one first light extraction layer, with the first light extraction layer located between the two second light extraction layers.

[0010] Furthermore, the optical functional layers located on the side of different light-emitting units away from the substrate have different thicknesses, and the optical functional layers include at least one first light extraction layer and at least one second light extraction layer.

[0011] Furthermore, the thickness of the second light extraction layer located at different light-emitting units is the same, and at least one of the first light extraction layers has a different thickness; Alternatively, the thickness of the first light extraction layer located at different light-emitting units is the same, and the thickness of at least one second light extraction layer is different.

[0012] Furthermore, the light-emitting unit includes a first light-emitting unit, a second light-emitting unit, and a third light-emitting unit. The first light extraction layer includes a first light extraction sub-part, a second light extraction sub-part, and a third light extraction sub-part. The first light extraction sub-part is located on the side of the first light-emitting unit away from the substrate. The second light extraction sub-part is located on the side of the second light-emitting unit away from the substrate. The third light extraction sub-part is located on the side of the third light-emitting unit away from the substrate. The orthographic projection of the first light-emitting unit on the substrate is within the orthographic projection range of the first light extraction sub-part on the substrate. The orthographic projection of the second light-emitting unit on the substrate is within the orthographic projection range of the second light extraction sub-part on the substrate. The orthographic projection of the third light-emitting unit on the substrate is within the orthographic projection range of the third light extraction sub-part on the substrate. The thickness of the third light extraction sub-part is greater than the thickness of the second light extraction sub-part, and the thickness of the second light extraction sub-part is greater than the thickness of the first light extraction sub-part.

[0013] Furthermore, the light-emitting unit includes a first light-emitting unit, a second light-emitting unit, and a third light-emitting unit. The second light extraction layer includes a fourth light extraction sub-part, a fifth light extraction sub-part, and a sixth light extraction sub-part. The fourth light extraction sub-part is located on the side of the first light-emitting unit away from the substrate. The fifth light extraction sub-part is located on the side of the second light-emitting unit away from the substrate. The sixth light extraction sub-part is located on the side of the third light-emitting unit away from the substrate. The orthographic projection of the fourth light-emitting unit on the substrate is within the orthographic projection range of the first light extraction sub-part on the substrate. The orthographic projection of the fifth light-emitting unit on the substrate is within the orthographic projection range of the second light extraction sub-part on the substrate. The orthographic projection of the sixth light-emitting unit on the substrate is within the orthographic projection range of the third light extraction sub-part on the substrate. The thickness of the sixth light extraction sub-part is greater than the thickness of the fifth light extraction sub-part, and the thickness of the fifth light extraction sub-part is greater than the thickness of the fourth light extraction sub-part.

[0014] The present invention also provides a display device, including the display panel as described above. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of a display panel provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of another display panel provided in an embodiment of the present invention; Figure 3 Schematic diagram of a display panel structure designed for different thicknesses of high refractive index light extraction layer; Figure 4 Schematic diagram of a display panel structure designed for different thicknesses of low-refractive-index light extraction layer; Figure 5 A schematic diagram of a display panel structure designed for a different thickness of another high-refractive-index light extraction layer; Figure 6 A schematic diagram of a display panel structure designed for different thicknesses of a high-refractive-index light extraction layer; Figure 7 A schematic diagram of a display panel structure designed for a different thickness of another low-refractive-index light extraction layer; Figure 8 This is an example structure of a light-emitting unit in a display panel; Figure 9 This is a schematic diagram of the structure of another display panel provided in an embodiment of the present invention; 101-Substrate; 200-Light-emitting structure layer; 201-Pixel definition layer; 202-Light-emitting unit; 202a-First electrode; 202b-Second electrode; 202c-Hole injection layer; 202d-Hole transport layer; 202e-Organic light-emitting layer; 202f-Electron transport layer; 202g-Electron injection layer; 202h-Functional layer; 2021-First light-emitting unit; 2022-Second light-emitting unit; 2023-Third light-emitting unit; 300-Optical functional layer; 301-First light extraction layer; 3011-First light extraction sub-section; 3012-Second light extraction sub-section; 3013-Third light extraction sub-section; 302-Second light extraction layer; 3021-Fourth light extraction sub-section; 3022-Fifth light extraction sub-section; 3023-Sixth light extraction sub-section Detailed implementation method: The accompanying drawings illustrate preferred embodiments of the present invention, demonstrating its implementability. These embodiments provide a complete overview of the invention to those skilled in the art, making its technical content clearer and easier to understand. The present invention can be embodied in many different forms of embodiments, and its scope of protection is not limited to the embodiments mentioned herein.

[0017] In the accompanying drawings, components with the same structure are indicated by the same numerical designation, and components with similar structures or functions are indicated by similar numerical designations. The dimensions and thicknesses of each component shown in the drawings are arbitrary, and the present invention does not limit the dimensions and thicknesses of each component. To make the illustrations clearer, the thickness of components is appropriately exaggerated in some places in the drawings.

[0018] Furthermore, the following descriptions of the embodiments of the invention are made with reference to the accompanying illustrations, illustrating specific embodiments in which the invention can be implemented. Directional terms used in this invention, such as "upper," "lower," "front," "rear," "left," "right," "inner," "outer," and "side," are merely directional references to the accompanying drawings. Therefore, the use of directional terms is for better and clearer explanation and understanding of the invention, and does not indicate or imply that the referred device or element must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0019] When a component is described as being "on" another component, the component may be placed directly on the other component; alternatively, there may be an intermediate component on which the component is placed, and the intermediate component is placed on the other component. When a component is described as being "installed to" or "connected to" another component, both can be understood as being directly "installed" or "connected" to, or as being indirectly "installed to" or "connected to" another component via an intermediate component.

[0020] In relevant display technologies, display panels employ a multi-layer light extraction layer structure. However, in existing multi-layer light extraction layer structures, the refractive index (n-value) of high-refractive-index light extraction layer materials varies significantly across different emission wavelengths, while the n-value of low-refractive-index light extraction layer materials varies less. This results in substantial differences in the n-values ​​of high-refractive-index and low-refractive-index light extraction layers across different wavelengths. Therefore, with the same multi-layer light extraction layer thickness, it is impossible to simultaneously achieve efficiency gains for different light colors.

[0021] Based on the technical problems discovered in the aforementioned related display technologies, this embodiment of the invention provides a display panel, such as... Figure 1 and Figure 2 As shown. Figure 1 This is a schematic diagram of the structure of a display panel provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of another display panel provided in an embodiment of the present invention. The display panel includes: a substrate 101; a light-emitting structure layer 200 located on one side of the substrate 101, including a plurality of light-emitting units emitting different colors of light; and an optical functional layer 300 located on the side of the light-emitting structure layer 200 away from the substrate 101, including at least two alternately arranged light extraction layers, wherein the light extraction layer includes a first light extraction layer 301 or a second light extraction layer 302, the refractive index of the first light extraction layer 301 is greater than the refractive index of the second light extraction layer 302, and the difference in refractive index between the first light extraction layer 301 and the second light extraction layer 302 satisfies: 0≤n1-n2≤0.2 and 0≤n3-n1≤0.4. Wherein, n1 is the refractive index difference between the first light extraction layer 301 and the second light extraction layer 302 in the first wavelength band, n2 is the refractive index difference between the first light extraction layer 301 and the second light extraction layer 302 in the second wavelength band, and n3 is the refractive index difference between the first light extraction layer 301 and the second light extraction layer 302 in the third wavelength band. This embodiment of the invention constructs a weak microcavity structure by combining high and low refractive index light extraction layers, enhancing the microcavity enhancement effect at specific wavelengths and mitigating total internal reflection loss caused by refractive index mismatch. Simultaneously, it improves the n-value matching between the low-refractive-index and high-refractive-index light extraction layers, reducing the n-value difference between them in different light color bands. Therefore, the multi-layer light extraction layer structure exhibits good efficiency gains under different light colors.

[0022] In this embodiment of the invention, the substrate 101 may be made of inorganic or organic materials. Inorganic materials may be glass or metal; non-limiting examples of glass materials include soda-lime glass, quartz glass, and sapphire glass; non-limiting examples of metal materials include stainless steel, aluminum, and nickel. Organic materials may be polymer materials, and non-limiting examples include polymethyl methacrylate (PMMA), polyvinyl alcohol (PVA), polyvinyl phenol (PVP), polyether sulfone (PES), polyimide (PI), polyamide, polyacetal, polycarbonate (PC), polyethylene terephthalate (PET), and polyethylene naphthalate (PET). One or more of naphthalate (PEN) are used. In some embodiments of the present invention, the substrate 101 is a flexible substrate, and its material may be selected from polyimide, for example. In some embodiments of the present disclosure, the substrate 101 may be configured as a multilayer composite structure. Exemplarily, the substrate 101 may include a base film layer, a pressure-sensitive adhesive layer, a first polyimide layer, and a second polyimide layer stacked sequentially.

[0023] The light-emitting structure layer 200 includes a pixel definition layer 201 and multiple light-emitting units 202 emitting different colors of light. The pixel definition layer 201 is located between the substrate 101 and the optical functional layer 300, serving to separate adjacent sub-pixels, prevent color mixing of the light-emitting materials, and define the opening area of ​​each light-emitting unit 202. In embodiments of the present invention, the pixel definition layer 201 can be made of inorganic materials, organic materials, or organic-inorganic hybrid materials, with the specific selection considering insulation, heat resistance, hydrophobicity, and process compatibility. For example, the pixel definition layer 201 can be a photosensitive organic resin, including: polyimide resins, acrylic resins, epoxy resins, phenolic resins, and polysiloxane resins. In some embodiments of the present invention, the above-mentioned organic materials may also have hydrophobic functional groups (such as fluorocarbon segments) added to give their surface ink / liquid-repellent properties, suitable for inkjet-printed OLED processes. For applications requiring higher barrier properties, thinner thickness, or higher resistance to plasma etching, the pixel definition layer 201 can be made of inorganic insulating materials, including silicon oxide (SiO2). x Silicon nitride (SiN) x ), silicon oxynitride (SiON) x Materials with conventional dielectric constants, such as aluminum oxide (AlO4), etc. x Titanium oxide (TiO)x ), hafnium oxide (HfO) x Materials with high dielectric constants, such as [material name], and stacked combinations of the above materials. Inorganic pixel definition layers are typically formed by plasma-enhanced chemical vapor deposition (PECVD) combined with dry etching to create patterns. Their advantages include narrower linewidths and steeper sidewalls, making them suitable for high PPI displays. In some embodiments of the present invention, the pixel definition layer 201 can be configured as a dual-layer structure of an organic bottom layer and an inorganic top layer. The bottom layer uses a photosensitive organic resin, formed into an inverted or regular trapezoidal cross-section through photolithography to facilitate self-alignment of the shadow effect during evaporation. The top layer uses a thin layer of inorganic material to cover defects and pinholes on the surface of the organic layer, improving overall barrier properties and enhancing the quality of the light-emitting layer. In other embodiments of the present invention, the pixel definition layer may also include a light-shielding function. For example, black pigments (such as carbon black, titanium black, aniline black) or near-infrared absorbing dyes can be doped into the aforementioned organic resin to form a black pixel definition layer, eliminating the need for a separate black matrix (BM) layer and further reducing the bezel size.

[0024] In this invention, multiple light-emitting units 202 are disposed on the substrate 101 and are at least partially located within the opening area defined by the pixel definition layer 201. The multiple light-emitting units 202 correspond to different colors (such as red, green, and blue) and are arranged in an array, isolated by the pixel definition layer 201, together constituting a full-color display panel. Figure 8As shown, one implementation of the light-emitting unit 202 is as follows: a first electrode 202a, a functional layer 202h, and a second electrode 202b are sequentially stacked on one side of the substrate 101. The first electrode 202a serves as the anode, used to inject holes into the functional layer 202h; the second electrode 202b serves as the cathode, used to inject electrons into the functional layer 202h. The functional layer 202h includes at least an organic light-emitting layer 202e, in which holes and electrons recombine to form excitons, thereby exciting the organic light-emitting layer 202e to emit light. The second electrode 202b is a transparent electrode, ensuring that at least a portion of the light emitted from the organic light-emitting layer 202e can pass sequentially through the second electrode 202b and the light extraction layer before being emitted outwards. Furthermore, the functional layer 202h of the light-emitting unit 202 may also be provided with an auxiliary film layer to improve luminous efficiency or light extraction efficiency. Non-limiting examples of these auxiliary films include a hole injection layer 202c, a hole transport layer 202d, an electron transport layer 202f, and an electron injection layer 202g. Each auxiliary film can be a single-layer or multi-layer structure. Specifically, the hole injection layer 202c and the hole transport layer 202d are disposed between the first electrode 202a and the organic light-emitting layer 202e; the electron transport layer 202f and the electron injection layer 202g are disposed between the second electrode 202b and the organic light-emitting layer 202e. In some embodiments, the functional layer 202h can be prepared using vapor deposition, inkjet printing, or a hybrid process combining both. For example, the organic light-emitting layer 202e and each auxiliary film layer of each light-emitting unit 202 can be formed separately using inkjet printing technology. This method allows for independent control of the thickness of the organic light-emitting layer 202e and the auxiliary film layers in each light-emitting unit 202, thereby facilitating targeted optimization of the light emission efficiency of each light-emitting unit 202.

[0025] An optical functional layer 300 is located on the side of the light-emitting structure layer 200 facing away from the substrate 101, and it itself includes at least two alternately arranged light extraction layers. In this embodiment of the invention, the light extraction layer is a multi-layer structure, taking two-layer and three-layer as examples. The light extraction layer includes a first light extraction layer 301 or a second light extraction layer 302. The refractive index of the first light extraction layer 301 is greater than the refractive index of the second light extraction layer 302. It is not limited to the side of the light-emitting structure layer 200 facing away from the substrate 101 being either the first light extraction layer 301 or the second light extraction layer 302. That is, the multi-layer light extraction layer structure can be any one of "first light extraction layer 301 + second light extraction layer 302", "second light extraction layer 302 + first light extraction layer 301", "first light extraction layer 301 + second light extraction layer 302 + first light extraction layer 301", and "second light extraction layer 302 + first light extraction layer 301 + second light extraction layer 302". This design uses alternating combinations of high and low refractive index materials to form a "light trap" structure, which refocuses the light that was originally scattered in all directions and lost due to electrode reflection and guides it to the front of the screen, thereby significantly improving the brightness and lifespan of the display panel without increasing power consumption.

[0026] In some embodiments, the display panel may further include an encapsulation layer disposed on the side of the light extraction layer facing away from the substrate 101. It is understood that when the display panel simultaneously includes a first light extraction layer 301 and a second light extraction layer 302, the encapsulation layer may be disposed on the side of the second light extraction layer 302 facing away from the substrate 101, or it may be disposed on the side of the first light extraction layer 301 facing away from the substrate 101. Furthermore, the display panel may also include a driving circuit layer disposed between the light-emitting structure layer 200 and the substrate 101, for driving each light-emitting unit 202 to emit light.

[0027] The refractive index of the first light extraction layer 301 is greater than or equal to 1.8, and the refractive index of the second light extraction layer 302 is less than 1.8. The difference in refractive index between the first light extraction layer 301 and the second light extraction layer 302 satisfies: 0≤n1-n2≤0.2 and 0≤n3-n1≤0.4. Preferably, the difference in refractive index satisfies: 0≤n1-n2≤0.15 and 0≤n3-n1≤0.25. Wherein, n1 is the refractive index difference between the first light extraction layer 301 and the second light extraction layer 302 in the first wavelength band, n2 is the refractive index difference between the first light extraction layer 301 and the second light extraction layer 302 in the second wavelength band, and n3 is the refractive index difference between the first light extraction layer 301 and the second light extraction layer 302 in the third wavelength band. The first wavelength band includes any wavelength in the range of 430nm-490nm, the second wavelength band includes any wavelength in the range of 500nm-560nm, and the third wavelength band includes any wavelength in the range of 590nm-650nm. The refractive index difference of the first light extraction layer 301 in the first and second wavelength bands ranges from 0 to 0.2, and the refractive index difference in the first and third wavelength bands ranges from 0 to 0.4; the refractive index difference of the second light extraction layer 302 in the first and second wavelength bands ranges from 0 to 0.1, and the refractive index difference in the first and third wavelength bands ranges from 0 to 0.2. For example, the first light extraction layer 301 has a refractive index of 2.0 in the first wavelength band, 1.9 in the second wavelength band, and 1.8 in the third wavelength band; the second light extraction layer 302 has a refractive index of 1.7 in the first wavelength band, 1.6 in the second wavelength band, and 1.5 in the third wavelength band. Therefore, the difference in refractive index between the first and second wavelength bands for the first light extraction layer 301 is 0.1, falling between 0 and 0.2, and the difference between the first and third wavelength bands is 0.2, falling between 0 and 0.4; the difference in refractive index between the second and third wavelength bands for the second light extraction layer 302 is 0.1, falling between 0 and 0.1, and the difference between the first and third wavelength bands is 0.2, falling between 0 and 0.2. n1, n2, and n3 are all 0.3, and also satisfy 0 ≤ n1 - n2 ≤ 0.2 and 0 ≤ n3 - n1 ≤ 0.4. In this way, the n-values ​​of the low-refractive-index light extraction layer material and the high-refractive-index light extraction layer material were matched and optimized, reducing the difference in n-values ​​between the two in different light color bands, thereby improving the light extraction efficiency in different light color bands.

[0028] Optionally, both the first light extraction layer 301 and the second light extraction layer 302 can be inorganic or organic materials with small differences in refractive index across different light color bands. For example, the first light extraction layer 301 can be silicon nitride or zirconium oxide, while the second light extraction layer 302 can be silicon oxide, aluminum oxide, or silicon oxynitride. The small difference in refractive index between the two materials across different bands allows for significant improvement in efficiency for different light colors. Furthermore, the identical structure and thickness of the multi-layer light extraction layers can be designed, reducing the number of metal vapor deposition masks required. In addition, because the thickness process window for the multi-layer light extraction layers is large, fluctuations in the thickness of the light extraction layers on the production line have a smaller impact on efficiency.

[0029] Optionally, both the first light extraction layer 301 and the second light extraction layer 302 can be inorganic or organic materials with significant differences in refractive index across different light color bands. For example, the first light extraction layer 301 can be selected from metal oxides such as titanium dioxide or yttrium-stabilized zirconium oxide (YSZ), while the second light extraction layer 302 can be selected from organic resins containing nano- to micron-sized pores or hollow or porous silica particles. The difference in refractive index between the two layers is small across different bands, making the materials for both the first and second light extraction layers 301 and 302 readily available. Similarly, this also allows for a significant improvement in the efficiency for different light colors, reducing the number of metal vapor deposition masks and lowering production costs.

[0030] As described above, the multilayer light extraction layer is not limited to the side of the light-emitting structure layer 200 facing away from the substrate 101 being either the first light extraction layer 301 or the second light extraction layer 302. Optionally, when the optical functional layer includes a first light extraction layer 301 and a second light extraction layer 302, the first light extraction layer 301 is located on the side of the second light extraction layer 302 facing away from the substrate 101, or the second light extraction layer 302 is located on the side of the first light extraction layer 301 facing away from the substrate 101 (e.g., Figure 2 (As shown). Optionally, when the optical functional layer includes two first light extraction layers 301 and one second light extraction layer 302, the second light extraction layer 302 is located between the two first light extraction layers 301 (e.g., Figure 1 As shown), or, the display panel includes two layers of the second light extraction layer 302 and one layer of the first light extraction layer 301, with the first light extraction layer 301 located between the two layers of the second light extraction layer 302 (as shown). Figure 9(As shown). The first light extraction layer 301 and the second light extraction layer 302 work together to more effectively focus and guide the scattered light to the surface of the display panel, further reducing light loss caused by repeated reflections from the electrodes (cathode / anode). Due to the improved light extraction efficiency, power consumption is significantly reduced at the same brightness. If the power consumption remains unchanged, the panel brightness can be increased. In addition, it directly slows down the aging rate of materials, which has a positive effect on product life.

[0031] In this embodiment of the invention, the multiple light extraction layers can be configured to have the same thickness or different thicknesses. The optical functional layers 300 located on the side of different light-emitting units 202 facing away from the substrate 101 have different thicknesses, and each optical functional layer includes at least one first light extraction layer 301 and at least one second light extraction layer 302. Specifically, the second light extraction layers located at different light-emitting units have the same thickness, and at least one first light extraction layer has a different thickness. Alternatively, the thickness of the first light extraction layer located at different light-emitting units is the same, and the thickness of at least one second light extraction layer is different.

[0032] In some embodiments, when the thickness of the second light extraction layer located at different light-emitting units is the same, and the thickness of at least one first light extraction layer is different, the light-emitting unit includes a first light-emitting unit, a second light-emitting unit, and a third light-emitting unit. The first light extraction layer includes a first light extraction sub-part, a second light extraction sub-part, and a third light extraction sub-part. The first light extraction sub-part is located on the side of the first light-emitting unit away from the substrate. The second light extraction sub-part is located on the side of the second light-emitting unit away from the substrate. The third light extraction sub-part is located on the side of the third light-emitting unit away from the substrate. The orthographic projection of the first light-emitting unit on the substrate is within the orthographic projection range of the first light extraction sub-part on the substrate. The orthographic projection of the second light-emitting unit on the substrate is within the orthographic projection range of the second light extraction sub-part on the substrate. The orthographic projection of the third light-emitting unit on the substrate is within the orthographic projection range of the third light extraction sub-part on the substrate. The thickness of the third light extraction sub-part is greater than the thickness of the second light extraction sub-part, and the thickness of the second light extraction sub-part is greater than the thickness of the first light extraction sub-part.

[0033] For example, such as Figure 3The illustrated "first light extraction layer 301 + second light extraction layer 302" structure has the same thickness for the second light extraction layer 302 corresponding to different light-emitting units, while the first light extraction layer 301 on the side of the second light extraction layer 302 facing away from the substrate 101 has a different thickness. Specifically, the thickness of the third light extraction sub-part 3013 is greater than the thickness of the second light extraction sub-part 3012, and the thickness of the second light extraction sub-part is greater than the thickness of the first light extraction sub-part 3011.

[0034] Optional, such as Figure 5 The illustrated "first light extraction layer 301 + second light extraction layer 302 + first light extraction layer 301" structure has the second light extraction layer 302, located between the two first light extraction layers 301, having a consistent thickness at different light-emitting units. The first light extraction layers 301 on the side of the second light extraction layer 302 facing away from the substrate 101 have different thicknesses. The thickness of the third light extraction sub-section 3013 is greater than the thickness of the second light extraction sub-section 3012, and the thickness of the second light extraction sub-section is greater than the thickness of the first light extraction sub-section 3011. And as shown... Figure 6 The illustrated structure of "first light extraction layer 301 + second light extraction layer 302 + first light extraction layer 301" shows that the second light extraction layer 302, located between the two first light extraction layers 301, has a consistent thickness at different light-emitting units. The two first light extraction layers 301 located on the side of the second light extraction layer 302 facing away from the substrate 101 and the side facing the substrate 101 have different thicknesses. The thickness of the third light extraction sub-section 3013 is greater than the thickness of the second light extraction sub-section 3012, and the thickness of the second light extraction sub-section is greater than the thickness of the first light extraction sub-section 3011. This configuration allows for similar microcavity effects between high-refractive-index and low-refractive-index light extraction layers at different light color bands, under different n-value characteristics of high-refractive-index and low-refractive-index light extraction layers, thereby achieving optimal microcavity effect and light extraction efficiency. The above description is merely an example. It is understood that the light extraction layer structure can also be "second light extraction layer 302 + first light extraction layer 301" or "second light extraction layer 302 + first light extraction layer 301 + second light extraction layer 302", which can also achieve the above-mentioned beneficial effects. Further details will not be elaborated here.

[0035] In other embodiments, when the thickness of the first light extraction layer located at different light-emitting units is the same, and the thickness of at least one second light extraction layer is different, the second light extraction layer includes a fourth light extraction sub-section, a fifth light extraction sub-section, and a sixth light extraction sub-section. The fourth light extraction sub-section is located on the side of the first light-emitting unit away from the substrate, the fifth light extraction sub-section is located on the side of the second light-emitting unit away from the substrate, and the sixth light extraction sub-section is located on the side of the third light-emitting unit away from the substrate. The orthographic projection of the fourth light-emitting unit on the substrate is within the orthographic projection range of the first light extraction sub-section on the substrate, the orthographic projection of the fifth light-emitting unit on the substrate is within the orthographic projection range of the second light extraction sub-section on the substrate, and the orthographic projection of the sixth light-emitting unit on the substrate is within the orthographic projection range of the third light extraction sub-section on the substrate. The thickness of the sixth light extraction sub-section is greater than the thickness of the fifth light extraction sub-section, and the thickness of the fifth light extraction sub-section is greater than the thickness of the fourth light extraction sub-section.

[0036] For example, such as Figure 4 The illustrated "first light extraction layer 301 + second light extraction layer 302" structure has the same thickness for the first light extraction layer 301 located at different light-emitting units, while the second light extraction layer 302 located on the side of the first light extraction layer 301 closer to the substrate 101 has a different thickness. Specifically, the thickness of the sixth light extraction sub-part 3023 is greater than the thickness of the fifth light extraction sub-part 3022, and the thickness of the fifth light extraction sub-part 3022 is greater than the thickness of the fourth light extraction sub-part 3021. Optionally, such as... Figure 7 The illustrated structure of "first light extraction layer 301 + second light extraction layer 302 + first light extraction layer 301" shows that the two first light extraction layers 301 located on the side of the second light extraction layer 302 closest to and away from the substrate 101 have the same thickness. The second light extraction layer 302 located between the two first light extraction layers 301 has different thicknesses at different light-emitting units. The thickness of the sixth light extraction sub-section 3023 is greater than the thickness of the fifth light extraction sub-section 3022, and the thickness of the fifth light extraction sub-section 3022 is greater than the thickness of the fourth light extraction sub-section 3021. Similarly, this configuration allows the microcavity effects of high-refractive-index light extraction layers and low-refractive-index light extraction layers to be similar under different n-value characteristics of high-refractive-index light extraction layers and low-refractive-index light extraction layers in different light color bands, thereby achieving optimal microcavity effect and light extraction efficiency.

[0037] The above description is merely an example. It is understood that the light extraction layer structure can also be "second light extraction layer 302 + first light extraction layer 301" or "second light extraction layer 302 + first light extraction layer 301 + second light extraction layer 302", which can also achieve the above-mentioned beneficial effects. Further details will not be elaborated here.

[0038] The method for preparing light extraction layers of different thicknesses in this embodiment of the invention includes: first depositing a whole light extraction layer and then etching it into light extraction sub-sections of different thicknesses corresponding to different light-emitting units; or sequentially depositing light extraction sub-sections of different thicknesses corresponding to different light-emitting units.

[0039] Table 1: n-value characteristics of the first optical extraction layer (with significant differences in n-values ​​across different wavelengths) and the second optical extraction layer at different wavelengths.

[0040] Referring to Table 1, when the first light extraction layer 301 uses a material with significantly different n-values ​​across different wavelength bands, comparing the n-value of the first light extraction layer 301 at 460nm, its n-value at 530nm decreases by 0.8. That is, the difference in n-value between the first light extraction layer 301 at 460nm and 530nm is 0.8. Similarly, the difference in n-value between 460nm and 620nm is 0.73. Similarly, the difference in n-value between the second light extraction layer 302 at 460nm and 530nm is 0, and the difference in n-value between 460nm and 620nm is 0.01. The difference in n-value between the first and second light extraction layer materials is 0.22 between 460nm and 530nm, and 0.30 between 460nm and 620nm.

[0041] Table 2: n-value characteristics of the first optical extraction layer (with small differences in n-values ​​across different wavelengths) and the second optical extraction layer at different wavelengths.

[0042] Referring to Table 2, when the first light extraction layer 301 uses a material with small differences in n-values ​​across different wavelength bands, comparing the n-value of the first light extraction layer 301 at 460nm, its n-value at 530nm decreases by 0.14. That is, the difference in n-value between the first light extraction layer 301 at 460nm and 530nm is 0.14. Similarly, the difference in n-value between 460nm and 620nm is 0.21. Similarly, the difference in n-value between the second light extraction layer 302 at 460nm and 530nm is 0, and the difference in n-value between 460nm and 620nm is 0.01. The difference in n-value between the first and second light extraction layer materials is 0.15 between 460nm and 530nm, and 0.24 between 460nm and 620nm.

[0043] Table 3. Simulation efficiency of devices with different first light extraction layer materials under the "first light extraction layer + second light extraction layer + first light extraction layer" structure for different colors of light.

[0044] Referring to Table 3, comparing the first light extraction layer 301 with materials having large differences in n-values ​​across different wavelengths, when the first light extraction layer 301 uses materials with smaller differences in n-values ​​across different wavelengths, the efficiency is improved regardless of whether it is red light, green light, blue light, or white light. This indicates that reducing the refractive index difference of the high-refractive-index light extraction layer material across different wavelengths, thereby reducing the refractive index difference between the high-refractive-index and low-refractive-index light extraction layers, can improve efficiency gains.

[0045] This invention also provides a display device, which includes the display panel described above. It can be installed as a display device in any electronic terminal with display functionality, such as a mobile phone, laptop, tablet computer, or in-vehicle display. The display device can be used to display static images, such as pictures or photographs. It can also be used to display dynamic images, such as videos.

[0046] In addition, the display device can also perform functions such as taking photos, recording videos, fingerprint recognition, and facial recognition. Accordingly, the display device also includes at least one functional module for implementing the above functions, such as an under-display camera or an under-display fingerprint recognition sensor.

[0047] The display device provided in the embodiments of the present invention and the display panel provided in the embodiments of the present invention belong to the same inventive concept, and have corresponding film layer structures and beneficial effects. Details not described in detail in the embodiments of the display device can be found in the embodiments of the display panel, and will not be repeated here.

[0048] The basic principles of the present invention have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in the present invention are merely examples and not limitations, and should not be considered as essential features of each embodiment of the present invention. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the present invention to the necessity of employing the aforementioned specific details.

[0049] The block diagrams of devices, apparatuses, devices, and systems involved in this invention are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0050] It should also be noted that in the apparatus, device, and method of the present invention, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered as equivalent solutions of the present invention.

[0051] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the invention. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of the invention. Therefore, the invention is not intended to be limited to the aspects shown herein, but rather to be carried out within the widest scope consistent with the principles and novel features disclosed herein.

[0052] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of the invention to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations therein.

[0053] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A display panel, characterized in that, include: Substrate; A light-emitting structure layer, located on one side of the substrate, includes multiple light-emitting units that emit different colors of light; An optical functional layer, located on the side of the light-emitting structure layer facing away from the substrate, includes at least two alternately arranged light extraction layers. Each light extraction layer includes a first light extraction layer or a second light extraction layer. The refractive index of the first light extraction layer is greater than that of the second light extraction layer, and the difference in refractive index between the first and second light extraction layers satisfies the following condition: 0 ≤ n1 - n2 ≤ 0.2 and 0 ≤ n³ - n¹ ≤ 0.4 Wherein, n1 is the refractive index difference between the first light extraction layer and the second light extraction layer in the first band, n2 is the refractive index difference between the first light extraction layer and the second light extraction layer in the second band, and n3 is the refractive index difference between the first light extraction layer and the second light extraction layer in the third band.

2. The display panel according to claim 1, characterized in that, The refractive index of the first light extraction layer is greater than or equal to 1.8, and the refractive index of the second light extraction layer is less than 1.

8.

3. The display panel according to claim 1, characterized in that, The refractive index difference between the first light extraction layer and the second light extraction layer satisfies: 0≤n1-n2≤0.15 and 0≤n3-n1≤0.

25.

4. The display panel according to claim 1, characterized in that, The refractive index of the first light extraction layer has a difference between 0 and 0.2 in the first and second wavebands, and a difference between 0 and 0.4 in the first and third wavebands; the refractive index of the second light extraction layer has a difference between 0 and 0.1 in the first and second wavebands, and a difference between 0 and 0.2 in the first and third wavebands.

5. The display panel according to claim 1, characterized in that, The optical functional layer includes a first light extraction layer and a second light extraction layer; the first light extraction layer is located on the side of the second light extraction layer that is away from the substrate. Alternatively, the second light extraction layer is located on the side of the first light extraction layer that is away from the substrate.

6. The display panel according to claim 1, characterized in that, The optical functional layer includes two first light extraction layers and one second light extraction layer, with the second light extraction layer located between the two first light extraction layers; Alternatively, the display panel may include two second light extraction layers and one first light extraction layer, with the first light extraction layer located between the two second light extraction layers.

7. The display panel according to claim 1, characterized in that, The optical functional layers located on the side of the light-emitting unit away from the substrate have different thicknesses, and the optical functional layers include at least one first light extraction layer and at least one second light extraction layer.

8. The display panel according to claim 7, characterized in that, The thickness of the second light extraction layer located at different light-emitting units is the same, and at least one of the first light extraction layers has a different thickness; Alternatively, the thickness of the first light extraction layer located at different light-emitting units is the same, and the thickness of at least one second light extraction layer is different.

9. The display panel according to claim 8, characterized in that, The light-emitting unit includes a first light-emitting unit, a second light-emitting unit, and a third light-emitting unit. The first light extraction layer includes a first light extraction sub-part, a second light extraction sub-part, and a third light extraction sub-part. The first light extraction sub-part is located on the side of the first light-emitting unit away from the substrate. The second light extraction sub-part is located on the side of the second light-emitting unit away from the substrate. The third light extraction sub-part is located on the side of the third light-emitting unit away from the substrate. The orthographic projection of the first light-emitting unit on the substrate is within the orthographic projection range of the first light extraction sub-part on the substrate. The orthographic projection of the second light-emitting unit on the substrate is within the orthographic projection range of the second light extraction sub-part on the substrate. The orthographic projection of the third light-emitting unit on the substrate is within the orthographic projection range of the third light extraction sub-part on the substrate. The thickness of the third light extraction sub-part is greater than the thickness of the second light extraction sub-part, and the thickness of the second light extraction sub-part is greater than the thickness of the first light extraction sub-part.

10. The display panel according to claim 8 or 9, characterized in that, The light-emitting unit includes a first light-emitting unit, a second light-emitting unit, and a third light-emitting unit. The second light extraction layer includes a fourth light extraction sub-section, a fifth light extraction sub-section, and a sixth light extraction sub-section. The fourth light extraction sub-section is located on the side of the first light-emitting unit away from the substrate. The fifth light extraction sub-section is located on the side of the second light-emitting unit away from the substrate. The sixth light extraction sub-section is located on the side of the third light-emitting unit away from the substrate. The orthographic projection of the fourth light-emitting unit onto the substrate is within the orthographic projection range of the first light extraction sub-section onto the substrate. The orthographic projection of the fifth light-emitting unit onto the substrate is within the orthographic projection range of the second light extraction sub-section onto the substrate. The orthographic projection of the sixth light-emitting unit onto the substrate is within the orthographic projection range of the third light extraction sub-section onto the substrate. The thickness of the sixth light extraction sub-section is greater than the thickness of the fifth light extraction sub-section, and the thickness of the fifth light extraction sub-section is greater than the thickness of the fourth light extraction sub-section.

11. A display device, characterized in that, Includes the display panel as described in any one of claims 1-10.

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