Display panel and manufacturing method thereof

Abstract

The present disclosure provides a display panel and a preparation method thereof, wherein the display panel comprises a substrate, a driving layer, the driving layer comprises an active layer, a gate layer, an interlayer dielectric layer, a source-drain electrode layer and a planarization layer, the active layer, the gate layer, the interlayer dielectric layer, the source-drain electrode layer and the planarization layer are stacked from bottom to top, the interlayer dielectric layer has a first refractive index, the planarization layer has a second refractive index, and the second refractive index is greater than the first refractive index, a transition layer is arranged between the planarization layer and the interlayer dielectric layer, and the transition layer has a third refractive index, the third refractive index is between the first refractive index and the second refractive index, so as to reduce the refractive index difference between the planarization layer and the interlayer dielectric layer and reduce the reflected light, by arranging the transition layer between the two layers with large refractive index difference, the problem of large reflectivity and low transmittance caused by large refractive index difference between different materials is effectively alleviated, and the overall performance of the display panel is optimized.

Description

Technical Field

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

[0002] In organic light-emitting diode (OLED) display panels, the complexity of the structure and the properties of the materials in each layer have a crucial impact on display performance. Display panels typically consist of multiple layers that work together to achieve image display. Among these, the interlayer dielectric layer and the planarization layer play indispensable roles in the overall structure; however, the difference in refractive index between them brings about a series of problems.

[0003] Due to the inorganic material properties of the interlayer dielectric layer and the organic material properties of the planarization layer, there is a significant difference in their refractive indices. According to optical principles, when light enters from one medium to another, reflection and refraction occur at the interface, and the degree of reflection and refraction is closely related to the difference in refractive indices between the two media. At the boundary between the interlayer dielectric layer and the planarization layer, a large amount of light is reflected due to the significant difference in refractive indices. This not only prevents light from passing smoothly through the display panel, reducing the overall transmittance of the display panel, but also has many negative impacts on the display effect. For example, reflected light will be reflected and scattered multiple times within the display panel, resulting in poor brightness uniformity and the appearance of local bright or dark spots; at the same time, the presence of reflected light will also interfere with the display of black images, reduce contrast, and make it difficult to clearly display details in the dark areas of the image, affecting the quality of the display and the visual experience. Summary of the Invention

[0004] In view of this, the purpose of this disclosure is to provide a display panel and a method for manufacturing the same, so as to solve the problem of reduced overall transmittance of the display panel caused by the large difference in refractive index between the interlayer dielectric layer and the planarization layer.

[0005] For the purposes described above, this application provides a display panel, comprising:

[0006] Substrate;

[0007] A driving layer is located on the substrate; the driving layer includes an active layer, a gate layer, an interlayer dielectric layer, a source / drain electrode layer, and a planarization layer, wherein the active layer, the gate layer, the interlayer dielectric layer, the source / drain electrode layer, and the planarization layer are stacked from bottom to top;

[0008] The interlayer dielectric layer is used to prevent short circuits between adjacent conductive layers and to ensure that current can be conducted between the functional layers according to the designed path; the interlayer dielectric layer has a first refractive index.

[0009] The planarization layer is used to fill the unevenness of the underlying layer, and the planarization layer has a second refractive index, which is greater than the first refractive index.

[0010] A transition layer is disposed between the planarization layer and the interlayer dielectric layer, and the transition layer has a third refractive index; the third refractive index is between the first refractive index and the second refractive index, so as to reduce the refractive index difference between the planarization layer and the interlayer dielectric layer and reduce reflected light.

[0011] Furthermore, the transition layer is made of inorganic materials.

[0012] Preferably, the transition layer is made of SiON.

[0013] Furthermore, the transition layer has at least one layer.

[0014] Furthermore, the thickness of the transition layer is less than the thickness of the interlayer dielectric layer.

[0015] Furthermore, the thickness of the transition layer is 100-400 nm;

[0016] Preferably, the thickness of the transition layer is 100 nm.

[0017] Furthermore, the third refractive index is 1.87-2.0;

[0018] Preferably, the third refractive index is 2.0.

[0019] Furthermore, the material of the interlayer dielectric layer is silicon nitride and silicon oxide.

[0020] Furthermore, a stepped area is formed on the display panel, and the height of the stepped area gradually decreases from top to bottom.

[0021] This application also provides a method for manufacturing a display panel, comprising the following steps:

[0022] A first display panel comprising a substrate and a driving layer is obtained; the driving layer is located on the substrate; the driving layer comprises an active layer, a gate layer, an interlayer dielectric layer, a source / drain electrode layer, and a planarization layer;

[0023] A transition layer material is selected, and the transition layer is disposed between the interlayer dielectric layer and the planarization layer to obtain the display panel;

[0024] The transmittance of the display panel is detected and optimized.

[0025] Furthermore, detecting and optimizing the transmittance of the display panel specifically includes:

[0026] The transmittance spectrum of the display panel after the transition layer is set is simulated to obtain the high transmittance area;

[0027] Select a suitable sensor based on the high transmittance zone and optimize the transition layer structure to obtain higher transmittance.

[0028] Compared with the prior art, the present invention has the following technical effects:

[0029] By setting an inorganic transition layer between the planarization layer and the interlayer dielectric layer, the problem of large refractive index difference between the planarization layer and the interlayer dielectric layer is reduced, the reflected light from the planarization layer to the interlayer dielectric layer is reduced, the transmittance of the display panel is improved, the impact on device performance is reduced, and the image colors of the display panel are more vivid, the details are clearer, and the visual experience is better. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in this disclosure or related technologies, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the structure of an existing display panel;

[0032] Figure 2 This is a schematic diagram of the structure of a display panel provided in one embodiment of this application;

[0033] Figure 3 This is a schematic diagram of a single-layer transition layer structure of a display panel provided in an embodiment of this application;

[0034] Figure 4 This is a schematic diagram of a multi-layer transition layer structure of a display panel provided in an embodiment of this application;

[0035] Figure 5 A flowchart illustrating a method for manufacturing a display panel according to an embodiment of this application;

[0036] Figure 6 A flowchart illustrating an optimized transmittance method for manufacturing a display panel according to an embodiment of this application;

[0037] Figure 7 The transmittance spectrum of a SiNx / SiNx stacked structure detected by a method for fabricating a display panel according to an embodiment of this application;

[0038] Figure 8The transmittance spectrum of a SiNx / SiON stacked structure detected by a method for fabricating a display panel according to an embodiment of this application;

[0039] Wherein, 100 is the substrate; 200 is the driving layer; 201 is the active layer; 202 is the gate layer; 203 is the interlayer dielectric layer; 204 is the source / drain electrode layer; 205 is the planarization layer; 206 is the transition layer; 2061 is the first transition layer; and 2062 is the second transition layer. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0041] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this disclosure should have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms "first," "second," and similar terms used in the embodiments of this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0042] The inventors, through long-term practical work, discovered the following problems in the relevant technology:

[0043] As shown in the figure, a conventional display panel includes a substrate 100 and a driving layer 200. The driving layer 200 is located on the substrate 100 and includes an active layer 201, a gate layer 202, an interlayer dielectric layer 203, a source / drain electrode layer 204, and a planarization layer 205. The active layer 201, gate layer 202, interlayer dielectric layer 203, source / drain electrode layer 204, and planarization layer 205 are stacked from bottom to top. The interlayer dielectric layer 203 is used to prevent short circuits between adjacent conductive layers and ensure that current can be conducted between the functional layers according to the designed path. In the above solution, the refractive index of the interlayer dielectric layer 203 and the planarization layer 205 has a large difference, which enhances the reflection effect, resulting in poor brightness uniformity and the appearance of local bright or dark spots. At the same time, the presence of reflected light also interferes with the display of black images, reduces contrast, and makes it difficult to clearly display dark details of the image, affecting the quality of the display and the visual experience.

[0044] For the reasons stated above, this application provides the following solution:

[0045] Figure 2 This is a schematic diagram of a display panel structure provided in an embodiment of the present application, including a substrate 100 and a driving layer 200. The driving layer 200 is located on the substrate 100, and includes an active layer 201, a gate layer 202, an interlayer dielectric layer 203, a source / drain electrode layer 204, and a planarization layer 205. The active layer 201, gate layer 202, interlayer dielectric layer 203, source / drain electrode layer 204, and planarization layer 205 are stacked from bottom to top. The interlayer dielectric layer 203 is used to prevent short circuits between adjacent conductive layers and ensure current. It can conduct light between functional layers according to the designed path; the interlayer dielectric layer 203 has a first refractive index; the planarization layer 205 is used to fill the unevenness of the underlying layer, and the planarization layer 205 has a second refractive index, which is greater than the first refractive index; a transition layer 206 is provided between the planarization layer 205 and the interlayer dielectric layer 203, and the transition layer 206 has a third refractive index; the third refractive index is between the first refractive index and the second refractive index, so as to reduce the refractive index difference between the planarization layer 205 and the interlayer dielectric layer 203 and reduce reflected light. In this embodiment, by providing a transition layer 206 between two layers with large refractive index differences, the problem of high reflectivity and low transmittance caused by large refractive index differences between different materials is effectively alleviated, thereby optimizing the overall performance of the display panel.

[0046] Substrate 100 is the fundamental support structure of the display panel, providing a physical support platform for the fabrication of subsequent layers and ensuring the stability of the entire panel during long-term use. The material selection for substrate 100 is crucial, requiring sufficient mechanical strength and good thermal stability. Typically, substrate 100 can be made of materials such as glass, plastic, or metal. Glass substrates 100 dominate the traditional display panel field due to their flatness, chemical stability, and thermal stability. During production, glass substrates 100 can withstand high temperatures and chemical treatments, ensuring no deformation or chemical reaction occurs during complex manufacturing processes, thus guaranteeing the uniform deposition and accurate patterning of subsequent thin films. However, with technological advancements, flexible substrates are increasingly favored due to their lightweight and bendability. In this embodiment, a flexible substrate 100 is used. The material of the flexible substrate 100 can be polyimide. Polyimide possesses excellent thermal stability and mechanical properties, enabling it to withstand bending and folding applications, making it suitable for manufacturing flexible displays. Furthermore, polyimide exhibits strong chemical stability, is corrosion-resistant and aging-resistant, maintaining good performance even under long-term use. Using this material as a substrate effectively improves the reliability and durability of the display panel. Furthermore, the selection of the flexible substrate 100 also enables the display panel to perform exceptionally well in certain specialized applications, such as wearable devices and automotive displays. Its flexibility allows it to better conform to irregular surfaces, providing a more comfortable user experience.

[0047] The driving layer 200, comprised of multiple functional layers working in concert, converts externally input electrical signals into precise control signals to drive OLED pixels to emit light in the desired manner. The functionality of the driving layer 200 relies on precise circuit design, including an active matrix array and thin-film transistors (TFTs). TFTs, acting as switching elements, control each OLED pixel and are the core components for pixel control. The performance of the TFTs directly affects the display quality of the display panel, including brightness, contrast, and response time. High-performance TFTs require characteristics such as low resistance and high mobility to ensure fast and stable current transmission, thereby achieving precise pixel control. The active matrix array is responsible for addressing and driving these TFTs.

[0048] The active layer 201 is a crucial component of the driving layer 200, enabling electron transport and control. Its material and structure determine the electrical performance of the TFT. Amorphous silicon active layer 201 was widely used in early display technologies due to its simple fabrication process and low cost. The disordered atomic arrangement of amorphous silicon results in relatively low electron mobility, but it can still meet basic requirements in applications with lower display performance demands, such as low-end LCDs. The emergence of polycrystalline silicon active layer 201 significantly improved TFT performance. Polycrystalline silicon has a relatively ordered atomic arrangement, resulting in much higher electron mobility than amorphous silicon, enabling faster switching speeds and higher current driving capabilities. This has led to the widespread use of polycrystalline silicon TFTs in high-resolution, high-refresh-rate display panels, such as those in high-end smartphones and tablets. Organic semiconductor materials, as active layer 201, have brought new directions to display technology. Organic semiconductor materials have advantages such as solution-processability and flexibility, enabling low-cost, large-area manufacturing and suitability for flexible displays. However, the stability and electrical properties of organic semiconductor materials still need to be further improved to meet the requirements for long-term stable use.

[0049] The gate layer 202 plays a crucial role in controlling current conduction and cutoff in TFTs. The choice of gate layer 202 material significantly impacts TFT performance. Metal gate materials such as molybdenum, aluminum, and copper possess excellent conductivity and stability, enabling efficient signal transmission and withstanding high-temperature processes. Molybdenum gates, with their high melting point and good corrosion resistance, are less prone to deformation during high-temperature processing, ensuring dimensional accuracy and thus improving TFT performance consistency. In advanced display technologies, the requirements for the gate layer 202 are increasingly stringent. To achieve higher resolution and faster response times, it is necessary to reduce the gate size and resistance. This necessitates that the gate layer 202 material not only possesses good conductivity but also better process adaptability. For example, while copper has higher conductivity than aluminum and molybdenum, it is prone to diffusion under certain process conditions, causing contamination of other functional layers. Therefore, special processes and materials are needed to address this issue, such as adding a barrier layer to the copper gate surface to prevent copper diffusion.

[0050] The interlayer dielectric layer 203 is a crucial component for ensuring the stable electrical performance of the display panel. Inorganic insulating materials such as silicon oxide (SiO) and silicon nitride (SiN) are commonly used interlayer dielectric materials. Silicon oxide possesses excellent insulation properties, chemical stability, and a low dielectric constant. The low dielectric constant reduces capacitive coupling during signal transmission, lowers signal interference, and improves the electrical performance of the display panel. Silicon nitride, on the other hand, has higher hardness and better moisture barrier properties, effectively preventing moisture and impurities from corroding other functional layers, thus improving the reliability and lifespan of the display panel. The fabrication process of the interlayer dielectric layer 203 significantly impacts its performance. Chemical vapor deposition (CVD) is a commonly used method; by precisely controlling parameters such as the flow rate, temperature, and pressure of the reactant gases, high-quality interlayer dielectric layer 203 can be fabricated. During fabrication, it is essential to ensure the uniformity and density of the interlayer dielectric layer 203's thickness to guarantee its insulation performance and short-circuit prevention capabilities. With the continuous advancement of display technology, the requirements for the interlayer dielectric layer 203 are constantly increasing. In high-resolution, high-refresh-rate display panels, the interlayer dielectric layer 203 needs to have better flatness and lower roughness to meet the requirements of high-precision photolithography processes.

[0051] The source / drain electrode layer 204 is a crucial component in a TFT for current input and output, and its performance directly affects the TFT's driving capability and the display panel's display effect. Metals such as aluminum and copper are commonly used materials for the source / drain electrode layer 204 due to their good conductivity and low resistance. Aluminum is relatively inexpensive and has good process adaptability, making it widely used in mass production. However, aluminum has relatively weak corrosion resistance and may corrode in harsh environments, affecting electrode performance. Copper has higher conductivity, reducing energy loss during current transmission and improving the TFT's driving capability. However, copper diffusion can contaminate other functional layers, affecting the stability of the display panel. To address this issue, a barrier layer is typically added to the copper electrode surface, or special processes are used to control copper diffusion. In some advanced display technologies, multilayer metal structures are used as source / drain electrodes to further improve electrode performance. For example, covering the copper electrode surface with a thin layer of titanium or titanium nitride can improve electrode adhesion and corrosion resistance while preventing copper diffusion.

[0052] The planarization layer 205 plays a crucial role in display panels, eliminating unevenness in the underlying layer and providing a smooth surface for the growth of subsequent layers. Organic materials such as polyimide are commonly used planarization layer materials due to their excellent flowability and filling properties. During preparation, a polyimide 205 solution can be uniformly coated onto the underlying surface, and then cured through processes such as baking, filling the tiny grooves and protrusions in the underlying layer to form a smooth surface.

[0053] The planarization layer 205 not only improves the uniformity of subsequent thin film deposition but also enhances the precision of the photolithography process. During photolithography, a smooth surface ensures uniform coating of the photoresist and consistent exposure, thereby improving patterning accuracy and reducing pattern deformation and defects. Furthermore, the planarization layer 205 also acts as a buffer, reducing stress concentration between different material layers and improving the reliability and stability of the display panel.

[0054] like Figure 3 As shown, the transition layer 206 is disposed between the planarization layer 205 and the interlayer dielectric layer 203. Its main function is to reduce the large refractive index difference between these two layers, thereby reducing reflected light and improving the optical performance of the display panel. Specifically, the transition layer 206 is made of inorganic materials. Inorganic materials typically possess excellent chemical and thermal stability. During the manufacturing and use of the display panel, it undergoes various complex process conditions and environmental factors, such as high temperatures, chemical reagent treatment, and prolonged electronic radiation. Inorganic materials can maintain their structural and performance stability under these conditions, ensuring that the transition layer can always fulfill its function of reducing refractive index differences and reducing reflected light. Taking silicon nitride (SiN) as an example, it does not easily decompose or undergo chemical reactions at high temperatures, effectively resisting the impact of high-temperature processes during manufacturing on its performance, thereby ensuring the long-term reliability of the display panel. Moreover, inorganic materials have good compatibility with other functional layers in the display panel, such as the inorganic interlayer dielectric layer 203 and the organic planarization layer 205. This compatibility is reflected in the strong interfacial bonding between materials, which reduces the likelihood of delamination and debonding, thus helping to maintain the overall stability of the display panel structure. Simultaneously, the interactions between inorganic materials are relatively simple, avoiding complex chemical reactions, reducing the difficulty of process control, and improving product yield. Furthermore, the optical properties of inorganic materials can be precisely controlled. For the transition layer 206, precise refractive index control is crucial. Inorganic materials can achieve precise refractive index adjustment by modifying their chemical composition and microstructure, meeting specific requirements between the planarization layer 205 and the interlayer dielectric layer 203. For example, silicon oxide, by changing its oxygen-silicon ratio and doping with other elements, can have its refractive index adjusted over a wide range, making it possible to achieve ideal optical performance matching.

[0055] The selection and design of the transition layer 206 require precise matching of the refractive indices of the planarization layer 205 and the interlayer dielectric layer 203. Some inorganic-organic hybrid materials with specific refractive indices or specially doped oxide materials are often used as transition layer materials. Preferably, the transition layer 206 is made of silicon oxynitride (SiON). The refractive index of SiON is typically between 1.8 and 2.0, a range that falls precisely between the refractive indices of common organic planarization layers 205 (such as polyimide, with a refractive index of approximately 1.6-1.7) and inorganic interlayer dielectric layers 203 (such as silicon nitride with a refractive index of approximately 2.0-2.1, and silicon oxide with a refractive index of approximately 1.4-1.5). This excellent matching characteristic allows SiON to effectively reduce the refractive index difference between the planarization layer and the interlayer dielectric layer, minimizing reflected light and improving the transmittance of the display panel. For example, in the display panel of this embodiment, using SiON as the transition layer 206 reduces the intensity of reflected light by approximately 30% within a specific wavelength range, significantly improving optical performance. Secondly, the fabrication process of SiON is quite mature in the semiconductor and display fields. It can be prepared using various methods such as chemical vapor deposition (CVD) and physical vapor deposition (PVD). Taking CVD as an example, by precisely controlling the flow rate and ratio of reactant gases such as silane, ammonia, and oxygen, as well as parameters such as reaction temperature and pressure, uniform and high-quality SiON films can be prepared. This mature fabrication process not only ensures the quality stability of the SiON transition layer 206 but also reduces production costs, making it suitable for large-scale industrial production. Furthermore, in addition to its excellent optical properties, SiON also possesses certain mechanical strength and insulation properties. In display panels, it can enhance the overall structural stability to a certain extent while preventing leakage between different conductive layers, thus improving the electrical performance of the display panel. Moreover, SiON has a certain barrier function against moisture and oxygen, protecting the internal organic functional layers from external environmental corrosion and extending the lifespan of the display panel.

[0056] It should be noted that the transition layer 206 must have at least one layer. For example... Figure 4As shown, the transition layer 206 includes a first transition layer 2061 and a second transition layer 2062. By setting multiple transition layers 206, more precise optical performance adjustment can be achieved by adjusting parameters such as the thickness and refractive index of each layer. For example, when it is necessary to optimize transmittance across multiple wavelength ranges, a single transition layer may not meet complex optical requirements. Multiple transition layers, through the synergistic effect between different layers, can more precisely control the reflection and refraction of light at different wavelengths. Taking a two-layer SiON transition layer as an example, by rationally designing the thickness and refractive index of the two layers, the transmittance in the blue and red light regions is increased by 10% and 8% respectively, achieving optical performance optimization over a wider wavelength range compared to a single-layer transition layer 206. In actual production, process parameters may fluctuate to some extent. The multi-layer transition layer 206 structure can, to some extent, compensate for the impact of process fluctuations. If the thickness or refractive index of a single-layer transition layer 206 deviates, it may significantly affect optical performance. However, in a multi-layer transition layer 206, a slight deviation in one layer can be compensated for by adjusting other layers, thereby ensuring relatively stable overall optical performance. For example, on a certain production line, a slight deviation in the thickness of one transition layer was caused by equipment failure. However, by fine-tuning the parameters of another transition layer 206, the optical performance of the final display panel still met the product requirements, improving the fault tolerance of production and the yield rate of products.

[0057] The thickness of the transition layer 206 is less than that of the interlayer dielectric layer 203. The transition layer 206 is mainly used to reduce the refractive index difference between the planarization layer 205 and the interlayer dielectric layer 203, thereby reducing reflected light. Its thickness only needs to effectively match the refractive indices of the two layers to optimize optical performance. If the transition layer 206 is too thick, light may be reflected and refracted multiple times within the transition layer 206, which may increase light loss and affect the transmittance of the display panel. For example, when the transition layer is too thick, some light cannot pass through smoothly within the transition layer and is absorbed by multiple reflections, resulting in a weakening of the final emitted light intensity and a reduction in display effect. Moreover, if the transition layer 206 is too thick, it may affect the electrical performance stability of the interlayer dielectric layer 203. For example, an excessively thick transition layer 206 may introduce additional impurities or defects, affecting the insulation effect of the interlayer dielectric layer 203, increasing the risk of leakage, and thus affecting the overall electrical performance and reliability of the display panel. When fabricating the transition layer 206, its thickness needs to be precisely controlled to ensure that its refractive index falls accurately between that of the planarization layer 205 and the interlayer dielectric layer 203. Excessive thickness or thinness can affect its optical performance, resulting in ineffective reduction of reflected light. Furthermore, the interface bonding between the transition layer 206 and the adjacent layers is also crucial; a good interface bonding can reduce interface defects and further improve optical performance. The introduction of the transition layer 206 not only improves the light transmittance of the display panel but also enhances its contrast and color performance.

[0058] In this embodiment, the thickness of the transition layer 206 is 100-400 nm. Within this thickness range, the transition layer 206 can effectively adjust the refractive index difference between the planarization layer 205 and the interlayer dielectric layer 203. When the thickness of the transition layer is less than 100 nm, it may not be able to fully exert its effect of reducing the refractive index difference, resulting in an insignificant reduction in reflected light. For example, some experiments have shown that when the thickness of the transition layer is less than 100 nm, the reduction in reflected light intensity is small, and the improvement on the optical performance of the display panel is limited. When the thickness of the transition layer exceeds 400 nm, as mentioned above, problems such as increased light loss and impact on electrical performance will occur. Secondly, transition layer materials such as SiON can maintain good structural stability and performance consistency within the thickness range of 100-400 nm. Within this thickness range, the microstructure of the material is relatively uniform, and there will be no internal stress concentration or increased defects due to excessive thickness. In addition, existing fabrication processes, such as chemical vapor deposition and physical vapor deposition, can control the thickness and quality of the transition layer relatively precisely within this thickness range. For example, chemical vapor deposition can prepare SiON transition layers 206 with uniform thickness and stable performance in the range of 100-400 nm by precisely controlling parameters such as reaction time and gas flow rate.

[0059] Preferably, the transition layer 206 has a thickness of 100 nm. Numerous experiments and actual production verifications have shown that a 100 nm thick transition layer 206 achieves a good balance between reducing reflected light and increasing transmittance. At this thickness, the transition layer 206 can effectively match the refractive index of the planarization layer 205 and the interlayer dielectric layer 203, minimizing reflected light. Furthermore, the 100 nm thickness is relatively easy to control in the fabrication process, reducing process complexity and production costs. Compared to a thicker transition layer 206, fabricating a 100 nm thick transition layer 206 requires less material and time, and has relatively lower equipment requirements. For example, in a display panel production line, fabricating a 100 nm thick transition layer 206 increases production efficiency by approximately 30% compared to fabricating a 400 nm thick transition layer, while reducing material costs by approximately 20%.

[0060] The third refractive index is 1.87-2.0. When light propagates at the interface of media with different refractive indices, reflection and refraction occur. The difference in refractive index between the interlayer dielectric layer 203, the planarization layer 205, and the transition layer 206 directly affects the intensity of reflected light. Since the second refractive index is greater than the first refractive index, light will be strongly reflected when propagating at the interface between the interlayer dielectric layer and the planarization layer, which will lead to increased light loss and affect the light transmittance and display effect of the display panel. The third refractive index of the transition layer 206 is between the first and second refractive indices, which can act as a buffer to reduce this abrupt change in refractive index, thereby effectively reducing the intensity of reflected light. For example, if the interlayer dielectric layer 203 is made of silicon oxide with a first refractive index of about 1.45, and the planarization layer 205 is made of some organic material with a second refractive index of about 1.65, placing a transition layer with a suitable third refractive index between them can significantly suppress the reflection of light at the interface. Materials such as SiON, commonly used in the transition layer 206, typically have a refractive index of around 1.8-2.0. This range precisely meets the requirement of being between the refractive indices of the common interlayer dielectric layer 203 and planarization layer 205. While different display panel material systems may vary, extensive experiments and practical experience have shown that a third refractive index of 1.87-2.0 achieves good optical matching in most cases. For example, when the first refractive index of the interlayer dielectric layer 203 is 1.4-1.5 and the second refractive index of the planarization layer 205 is 1.6-1.7, a third refractive index of 1.87-2.0 can effectively reduce the refractive index difference and optimize optical performance.

[0061] Preferably, the third refractive index is 2.0. When the third refractive index is 2.0, an optimal balance is achieved between reducing reflected light and increasing transmittance. At this point, the propagation efficiency of light between layers is highest, and light loss is minimal. In this embodiment, by using a transition layer with a third refractive index of 2.0, the transmittance reaches over 90% in the visible light band, which is sensitive to the human eye, while the reflectance is reduced to below 5%. This results in more vibrant and realistic colors and deeper blacks in the displayed image, greatly enhancing the user's visual experience.

[0062] like Figure 4As shown, stepped regions are formed on the transition layer 205 and the interlayer dielectric layer 203, with the height of the steps gradually decreasing from top to bottom. During the display panel manufacturing process, multilayer thin-film deposition and photolithography processes are performed alternately. The patterning and stacking of different functional layers can lead to height differences on the surface. For example, when fabricating structures such as the active layer 201 and the gate layer 202, the photolithography process etches patterns of different shapes and heights. Subsequent interlayer dielectric layers, such as 203, are deposited on top of these patterns, easily forming stepped regions. Furthermore, to achieve specific circuit connections and functional layouts, the fabrication of metal electrodes such as M3 requires the formation of connection points at different height levels, which also contributes to the formation of stepped regions. In addition, the different deposition and etching rates of different materials are also a reason for the formation of stepped regions. For example, inorganic materials such as SiN and SiO and organic materials such as PLN2 grow or are removed at different rates under the same process conditions. During deposition, this results in surface unevenness, which gradually accumulates to form stepped regions. Furthermore, different materials have different stress characteristics. During annealing and other processes after thin film deposition, the degree of material shrinkage or expansion varies, further exacerbating surface undulations and forming stepped regions. When the step height gradually decreases from top to bottom, the resistance encountered by light during propagation is relatively reduced. Compared to steps with larger height differences, the degree of light scattering and diffuse reflection is reduced. This helps improve light transmittance, allowing more light to escape smoothly and increasing the brightness of the display panel. Simultaneously, it also improves brightness uniformity, making the displayed image more uniform and clear. In addition, the gradually decreasing step height facilitates the continuous laying of conductive layers such as metal electrodes. It can reduce the amplitude of resistance changes, making current transmission more stable. This helps ensure the consistency of TFT performance, improves the stability of pixel driving current, thereby improving the accuracy and uniformity of displayed colors, as well as the stability of response time. Moreover, the relatively gentle step region allows for a more uniform electric field distribution, reducing local electric field concentration, lowering the risk of leakage, and improving the electrical reliability of the display panel. This gradually decreasing step structure is also more compatible with other process steps in subsequent processing. For example, during the planarization process, it is easier to achieve uniform filling and planarization in step regions where the height gradually decreases. This also better ensures the uniformity and quality of the film during subsequent deposition, reduces film defects caused by abrupt changes in step height, and improves production yield.

[0063] This invention reduces the problem of large refractive index difference between the planarization layer and the interlayer dielectric layer by setting an inorganic transition layer between the planarization layer and the interlayer dielectric layer. This reduces the reflected light from the planarization layer to the interlayer dielectric layer, improves the transmittance of the display panel, reduces the impact on device performance, and makes the image colors of the display panel more vivid, the details clearer, and the visual experience better.

[0064] like Figure 5As shown, a method for manufacturing a display panel includes the following steps:

[0065] S1: Obtain a first display panel including a substrate 100 and a driving layer 200; the driving layer 200 is located on the substrate 100; the driving layer 200 includes an active layer 201, a gate layer 202, an interlayer dielectric layer 203, a source / drain electrode layer 204, and a planarization layer 205;

[0066] The first display panel refers to the panel excluding the transition layer, such as... Figure 1 As stated above.

[0067] S2: Select the transition layer 206 material and place the transition layer 206 between the interlayer dielectric layer 203 and the planarization layer 205 to obtain the display panel;

[0068] It should be noted that the material of the transition layer 206 is preferably an inorganic material, such as SiON. SiON has good optical properties and chemical stability, and its refractive index is between that of the interlayer dielectric layer 203 and the planarization layer 205, which can effectively reduce the refractive index difference between the two and reduce reflected light.

[0069] In this embodiment, a transition layer 206 is disposed between the interlayer dielectric layer 203 and the planarization layer 205 using chemical vapor deposition. During the deposition process, the composition and refractive index of the transition layer 206 are adjusted to meet design requirements by precisely controlling the flow rates and ratios of silicon, nitrogen, and oxygen source gases, as well as parameters such as reaction temperature and pressure. Simultaneously, the thickness of the transition layer 206 is controlled, typically between 100-400 nm, preferably 100 nm, to ensure its optical performance and process feasibility.

[0070] S3: Detect the transmittance of the display panel and optimize the transmittance.

[0071] It should be noted that, as Figure 6 As shown, detecting and optimizing the transmittance of the display panel specifically includes:

[0072] S301: Perform a transmittance spectrum simulation test on the display panel after setting the transition layer 206 to obtain the high transmittance area;

[0073] Through simulation testing, transmittance data of the display panel at different wavelengths can be obtained, and a transmittance spectrum curve can then be plotted. This curve is plotted with wavelength on the x-axis and transmittance on the y-axis. For example... Figure 7 , 8 As shown, Figure 7 This is the transmittance spectrum of the SiNx / SiNx stacked structure. Figure 7This is the transmittance spectrum of a SiNx / SiON stacked structure. On the transmittance spectrum curve, identify the wavelength range with relatively high transmittance; this range is the high-transmittance region. Generally, the wavelength range corresponding to the high-transmittance region is the visible light band to which the human eye is most sensitive, such as 400-700 nm.

[0074] S302: Select a suitable sensor based on the high transmittance zone and optimize the structure of the transition layer 206 to obtain higher transmittance.

[0075] The selected sensor's response band must match the high-transmittance area to accurately detect the display panel's transmittance in that area. Simultaneously, the sensor needs high sensitivity and accuracy to detect minute changes in transmittance.

[0076] Optimizing the structure of the transition layer 206 includes adjusting its thickness, which significantly affects transmittance. The thickness value that maximizes transmittance in the high-transmittance region can be determined experimentally or through simulation. Generally, within a certain range, increasing the thickness of the transition layer 206 initially increases transmittance but then decreases it, indicating an optimal thickness. The refractive index of the transition layer 206 needs to be between that of the interlayer dielectric layer 203 and the planarization layer 205. By adjusting the material composition or fabrication process parameters of the transition layer 206, its refractive index can be altered, thereby optimizing transmittance.

[0077] It should be noted that the above description describes some embodiments of this disclosure. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in a different order than that shown in the above embodiments and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0078] This disclosure is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A display panel, characterized in that, include: Substrate; A driving layer is located on the substrate; the driving layer includes an active layer, a gate layer, an interlayer dielectric layer, a source / drain electrode layer, and a planarization layer, wherein the active layer, the gate layer, the interlayer dielectric layer, the source / drain electrode layer, and the planarization layer are stacked from bottom to top; The interlayer dielectric layer is used to prevent short circuits between adjacent conductive layers and to ensure that current can be conducted between the functional layers according to the designed path; the interlayer dielectric layer has a first refractive index. The planarization layer is used to fill the unevenness of the underlying layer, and the planarization layer has a second refractive index, which is greater than the first refractive index. A transition layer is provided between the planarization layer and the interlayer dielectric layer, and the transition layer has a third refractive index; the third refractive index is between the first refractive index and the second refractive index, so as to reduce the refractive index difference between the planarization layer and the interlayer dielectric layer and reduce reflected light.

2. The display panel according to claim 1, characterized in that, The transition layer is made of inorganic materials; Preferably, the transition layer is made of SiON.

3. The display panel according to claim 1, characterized in that, The transition layer has at least one layer.

4. The display panel according to claim 1, characterized in that, The thickness of the transition layer is less than the thickness of the interlayer dielectric layer.

5. The display panel according to claim 1, characterized in that, The thickness of the transition layer is 100-400 nm; Preferably, the thickness of the transition layer is 100 nm.

6. The display panel according to claim 1, characterized in that, The third refractive index is 1.87-2.0; Preferably, the third refractive index is 2.

0.

7. The display panel according to claim 1, characterized in that, The interlayer dielectric layer is made of silicon nitride and silicon oxide.

8. The display panel according to claim 1, characterized in that, The display panel has a stepped area, and the height of the steps gradually decreases from top to bottom.

9. A method for manufacturing a display panel, characterized in that, Includes the following steps: A first display panel comprising a substrate and a driving layer is obtained; the driving layer is located on the substrate; the driving layer comprises an active layer, a gate layer, an interlayer dielectric layer, a source / drain electrode layer, and a planarization layer; A transition layer material is selected, and the transition layer is disposed between the interlayer dielectric layer and the planarization layer to obtain the display panel; The transmittance of the display panel is detected and optimized.

10. The preparation method according to claim 9, characterized in that, Detecting and optimizing the transmittance of the display panel specifically includes: The transmittance spectrum of the display panel after the transition layer is set is simulated to obtain the high transmittance area; Select a suitable sensor based on the high transmittance zone and optimize the transition layer structure to obtain higher transmittance.

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