Light-emitting structure and display panel

Abstract

The utility model provides a light-emitting structure and a display panel. The light-emitting structure comprises a driving substrate; the multiple bonding layers are arranged on one side of the driving substrate at intervals; the luminous source is arranged on one side, far away from the driving substrate, of the bonding layer; wherein one side, close to the luminous source, of the bonding layer is provided with a light-operated layer, and the light-operated layer is provided with wavefront in paraboloid phase distribution. According to the light-emitting structure, the metasurface layer is formed on the bonding layer, so that the bonding layer can generate the optical characteristic of focusing light on the basis of realizing electrical connection and heat dissipation effects, and the brightness and the working efficiency of the light-emitting structure are improved.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a light-emitting structure and a display panel. Background Technology

[0002] In some display devices, the limited thickness of quantum dot (QD) materials affects the light absorption and emission characteristics of the quantum dot film, leading to blue light leakage when blue backlight LEDs (BLEDs) and quantum dot films are used together. Therefore, color filters (CFs) are added in related technologies to filter out blue light and ensure color gamut. However, the filtering capability of color filters is limited, resulting in a bottleneck in the maximum brightness of quantum dot-micro LEDs (QD-Micro LEDs). Therefore, improving brightness has always been a key area of ​​focus for improvement in this type of display device. Summary of the Invention

[0003] Embodiments of this application provide a light-emitting structure and a display panel to solve the problem of difficulty in improving the maximum brightness of QD-Micro LEDs in related technologies.

[0004] To solve the above problems, the technical solution provided in this application is as follows:

[0005] In a first aspect, this application provides a light-emitting structure, comprising:

[0006] Drive substrate;

[0007] A bonding layer, having multiple layers spaced apart on one side of the driving substrate; and

[0008] A light source is disposed on the side of the bonding layer away from the driving substrate;

[0009] The bonding layer has a photocontrol layer on the side closest to the light source, and the photocontrol layer has a wavefront with a parabolic phase distribution.

[0010] In one embodiment, the light control layer includes:

[0011] A metasurface layer connected to the bonding layer, the metasurface layer comprising the same material as the bonding layer.

[0012] In one embodiment, the metasurface layer comprises at least a plurality of cells arranged in a single layer, with gaps between the plurality of cells;

[0013] The light control layer further includes a dielectric layer, which is fixed in the gap by abutment.

[0014] In one embodiment, the cell includes any one or more combinations of solids of revolution, prisms, and frustums.

[0015] In one embodiment, the ratio of the thickness of the metasurface layer to the operating wavelength of the metasurface layer ranges from 0.1 to 0.8.

[0016] In one embodiment, the projected area of ​​the bonding layer on the driving substrate is larger than the projected area of ​​the light source on the driving substrate.

[0017] In one embodiment, the light-emitting structure further includes:

[0018] A passivation layer is disposed on one side of the driving substrate and covers the bonding layer and the light source;

[0019] The passivation layer comprises the same material as the dielectric layer.

[0020] In one embodiment, the passivation layer has a plurality of grooves on the side away from the driving substrate, the grooves being at least used to accommodate quantum dot material or transparent material;

[0021] The groove has a trapezoidal cross-section, and the projection of the groove on the driving substrate overlaps with the projection of the bonding layer on the driving substrate.

[0022] The light-emitting structure further includes a reflective layer, which is fixedly connected to the inner sidewall of the groove, and the surface of the reflective layer is in direct contact with the quantum dot material or the transparent material.

[0023] In one embodiment, the light-emitting structure further includes:

[0024] A lens layer is disposed on the side of the passivation layer away from the driving substrate, and the projection of the lens layer on the driving substrate overlaps with the projection of the bonding layer on the driving substrate.

[0025] Secondly, this application provides a display panel including the aforementioned light-emitting structure.

[0026] This application provides a light-emitting structure and a display panel. The light-emitting structure includes a driving substrate; a bonding layer having multiple layers spaced apart on one side of the driving substrate; and a light source disposed on the side of the bonding layer away from the driving substrate. A light control layer is provided on the side of the bonding layer near the light source. The light control layer has a wavefront with a parabolic phase distribution to focus light incident on the light control layer. This light-emitting structure, by forming a metasurface layer on the bonding layer, enables the bonding layer to generate optical characteristics for focused light, in addition to providing electrical connection and heat dissipation, thereby improving the brightness and operating efficiency of the light-emitting structure. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application, 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 this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Appendix Figure 1 This is a cross-sectional schematic diagram of an optional light-emitting structure in an embodiment of this application;

[0029] Appendix Figure 2 Based on Figure 1 A magnified view of a portion of the light-emitting structure;

[0030] Appendix Figure 3 This is a cross-sectional schematic diagram of another optional light-emitting structure in the embodiments of this application;

[0031] Appendix Figure 4 This is a schematic diagram of the surface array assembly structure of the metasurface layer in the embodiments of this application;

[0032] Appendix Figure 5 This is a schematic diagram of the cross-sectional structure of the metasurface layer in the embodiments of this application;

[0033] Appendix Figure 6 This is a simulation diagram of the side structure of the metasurface layer in the embodiments of this application;

[0034] Appendix Figure 7 This is a diagram showing the light-gathering effect of the surface array of the metasurface layer in the embodiments of this application.

[0035] Appendix Figure 8 This is a schematic diagram of the energy distribution of the light-emitting structure in the embodiments of this application from one viewpoint.

[0036] Appendix Figure 9 This is a schematic diagram of the energy distribution of the light-emitting structure in the embodiments of this application from another perspective;

[0037] Appendix Figure 10 This is a schematic diagram of an optional cell structure in an embodiment of this application;

[0038] Appendix Figure 11 Figure 11 (a) to Figure 11 (d) is a simulation diagram of the light reflection effect corresponding to different sized cells in the embodiments of this application;

[0039] Appendix Figure 12 This is a schematic diagram of the fabrication steps of the light-emitting structure in the embodiments of this application;

[0040] Appendix Figure 13This is a flowchart illustrating the fabrication process of the light-emitting structure in the embodiments of this application.

[0041] 10. Light-emitting structure;

[0042] 100, Driving substrate; 200, Bonding layer; 300, Light source; 400, Light control layer; 410, Metasurface layer; 411, Cell; 420, Insulating layer; 500, Passivation layer; 501, Groove; 510, Lens layer; 600, Color conversion layer; 700, Color filter layer; 800, Reflective layer. Detailed Implementation

[0043] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0044] In the accompanying drawings, the thickness of layers, films, plates, regions, etc., may be exaggerated for clarity, better understanding, and ease of description. It should be understood that when an element such as a layer, film, region, or substrate is referred to as "located on another element," it may be located directly on the other element or there may be inserted elements.

[0045] Furthermore, unless explicitly stated otherwise, the word "including" and its variations such as "comprising" or "containing" will be understood to imply the inclusion of the discussed element, but not necessarily the exclusion of other elements. Further, in the specification, the phrase "on" refers to placement above or below the object part, and not necessarily to placement on the upper side of the object part based on the direction of gravity.

[0046] It will be understood that although the terms “first,” “second,” etc., may be used in this document to describe various components, these components should not be limited by these terms. These terms are used only to distinguish one component from another.

[0047] Reference Figures 1 to 3 As shown, according to a first aspect of this application, a light-emitting structure 10 is provided, including a driving substrate 100, a bonding layer 200, a light source 300, and a light control layer 400.

[0048] The driving substrate 100 is used to construct the driving circuit of the display panel to control the brightness and color of each pixel. In some embodiments of this application, the driving substrate 100 may be a silicon-based complementary metal-oxide-semiconductor (CMOS) backplane or a thin-film transistor (TFT) field-effect transistor display substrate.

[0049] The bonding layer 200 is provided with multiple layers spaced apart on one side of the driving substrate 100. In some embodiments of this application, the bonding layer 200 may include a multilayer structure of metal film and non-metal film composite, or it may only include metal film. The metal film includes Cr, Ni, Au, Ag, Sn, Ti, Pt and Pb, etc., and the non-metal film includes indium tin oxide (ITO) film, etc. This multilayer structure can improve the overall material strength and flexibility of the bonding layer, and at the same time, it can combine the conductivity characteristics of different materials to optimize the overall conductivity and resistance characteristics.

[0050] In some other embodiments of this application, the bonding layer 200 may also be a single-layer metal film. Since heat does not need to pass through multiple layers of materials for heat dissipation, a single-layer metal film can dissipate heat more effectively. At the same time, since the additional deposition steps required by the multi-layer structure are not required, the design of using a single-layer metal film is also beneficial to reducing production complexity and cost.

[0051] Furthermore, in some embodiments of this application, the projected area of ​​the bonding layer 200 on the driving substrate 100 is larger than the projected area of ​​the light source 300 on the driving substrate 100. It should be noted that the bonding layer 200 provides conductive connections, ensuring efficient current transmission to other functional layers. A larger area reduces resistance and helps improve current transmission efficiency. Simultaneously, since the bonding layer 200 helps dissipate heat during display panel operation, a larger area allows for more effective heat dissipation, dispersing the heat generated by the light source over a larger area, thereby improving the stability and lifespan of the display panel. The bonding layer 200 also provides good mechanical support within the display panel and acts as an interface between different surfaces, preventing inter-material diffusion to maintain device stability.

[0052] A light source 300 is disposed on the side of the bonding layer 200 away from the driving substrate 100. A light control layer 400 is disposed on the side of the bonding layer 200 near the light source 300. The light control layer has a wavefront with a parabolic phase distribution to focus the light incident on the light control layer. It should be noted that in a self-emissive display, each pixel is itself a light source. Within a short distance such as the pixel pitch, the propagation of these lights can be considered approximately parallel. However, through the light control layer 400, a micro-nano scale optical structure can be used to converge these lights, focusing the plane waves into a single point, improving the light utilization efficiency, and thus increasing brightness.

[0053] Specifically, refer to Figure 2 As shown, in some embodiments of this application, the light control layer 400 includes a metasurface layer 410, which is connected to the bonding layer 200. The metasurface layer 410 may be made of the same material as the bonding layer. In some more specific embodiments, the metasurface layer 410 may be the same as the bonding layer, including metallic materials with good electrical conductivity and surface plasmon properties such as gold, silver, or aluminum.

[0054] It should be noted that although the light control layer 400 is disposed on one side of the bonding layer 200 and connected as a whole, the metasurface layer 410 and the bonding layer 200 may not be formed in the same process. Therefore, using the same material for both is beneficial to simplify the process, improve the compatibility between layers, reduce interface problems such as delamination, and since the bonding layer also needs to play a heat dissipation role, using the same material for both means having the same coefficient of thermal expansion, which helps to reduce thermal stress and deformation when the temperature changes, and improve the durability of the display panel.

[0055] In addition to using the same materials as the bonding layer, in some other embodiments, the metasurface layer may also include semiconductor materials such as silicon (Si) or gallium nitride (GaN), utilizing their electrical and optical properties to tune the metasurface. Alternatively, two-dimensional materials such as graphene and transition metal dichalcogenides (such as MoS22) may be combined with other materials, and their unique optoelectronic and ultrathin properties allow for more flexible control over the metasurface design.

[0056] Reference Figure 4 As shown, and more specifically, in some embodiments of this application, the metasurface layer comprises at least a plurality of cells arranged in a single layer, and refers to... Figure 5 and Figure 6As shown, gaps are provided between the multiple cells. It should be noted that a metasurface is essentially a two-dimensional planar structure composed of a large number of subwavelength artificial units (typically nanoantennas or dielectric pillars) that can modulate the properties of incident light. The core of a metasurface is to alter the phase of light through tiny structures (called cells or meta-atoms) on its surface. The geometry, size, and arrangement of each cell are carefully designed so that light experiences a specific phase delay as it passes through these units. (Refer to...) Figure 7 The simulation design shown demonstrates how a metasurface can focus, deflect, or shape light by creating a phase gradient within the plane. For example, to achieve focusing, the phase distribution needs to satisfy a parabolic phase profile, meaning the phase gradually changes from the center to the edge, thus converging the plane wave into a single point. The final effect is shown in the reference [reference needed]. Figure 8 and Figure 9 As shown, where, Figure 8 This is a lateral energy distribution map. Figure 9 The diagram shows the energy distribution from a top-down perspective. It can be seen that, regardless of the viewing angle, the energy distribution is concentrated at a single point and stably output outwards through the focusing effect of the metasurface.

[0057] Building upon this, the optical control layer further includes a dielectric layer, which is fixed within the gap by an abutment mechanism. By filling the gaps between cells with a dielectric layer, a smooth surface can be formed for subsequent processing. Furthermore, the dielectric layer can alter the overall electromagnetic response of the metasurface layers, and selecting different dielectric constant materials can help adjust the reflective properties of the metasurface. In some more specific examples, the dielectric layer 420 may include dielectric materials such as silicon dioxide (SiO2), silicon nitride (Si3N4), or barium titanate (BaTiO3). These dielectric materials have low losses and can accommodate more efficient optical manipulation. The specific materials used can be designed according to actual needs, and this application does not impose any limitations.

[0058] More specifically, in some embodiments of this application, the ratio of the thickness of the metasurface layer to the operating wavelength of the metasurface layer ranges from 0.1 to 0.8, and more specifically, it can also be from 0.2 to 0.6. With this setting, the phase, amplitude, and polarization of light can be controlled without significantly increasing the thickness of the light-emitting structure 10.

[0059] It should be noted that the operating wavelength of the metasurface layer refers to the specific wavelength range within which the metasurface can effectively control electromagnetic waves. In this application, the metasurface layer is mainly used to control the emitted light from the light source. Therefore, the operating wavelength of the metasurface layer in this application can be between 400 nm and 700 nm, and the thickness of the metasurface layer can be set between 40 nm and 560 nm. More specifically, depending on different application scenarios and materials, the thickness of the metasurface layer will also be different. In some embodiments of this application, when the metasurface layer uses the same material as the bonding layer, such as Au, the thickness of the metasurface can be set between 70 nm and 300 nm, specifically, it can be 200 nm. nm; In other embodiments of this application, when the metasurface uses a different material than the bonding layer, such as TiO2, the thickness of the metasurface layer can range from 150 nm to 250 nm, or from 200 nm to 300 nm, or from 250 nm to 350 nm, depending on the required operating wavelength; when the metasurface uses Si3N4, its thickness can range from 200 nm to 400 nm or from 350 nm to 600 nm, depending on the different operating wavelengths; when the metasurface uses GaN, its thickness can range from 300 nm to 450 nm; and when the metasurface uses Si, its thickness can range from 250 nm to 350 nm.

[0060] Furthermore, the refractive index and absorption characteristics of the material forming the metasurface layer also influence the choice of its thickness. Using materials with higher refractive indices allows for thinner metasurface layer designs while still enabling effective light manipulation. Specifically, silicon (Si) as mentioned above, or silicon with a refractive index of approximately 3.5, can be used. It will be understood that with technological advancements, metasurface layers can also utilize materials with even higher refractive indices. Combined with relevant resonance or geometric phase designs, it is even possible to achieve a light control layer thickness of less than 40 nm. This application does not impose any limitations on this.

[0061] More specifically, in some embodiments of this application, the cell includes any one or more combinations of solids of revolution, prisms, and frustums. See also... Figure 10 As shown, optionally, the cell can adopt an approximate cylindrical structure as illustrated. It should be noted that... Figure 4 The metasurface structure shown and Figure 10 The cellular structure shown is marked with some wireframes. These wireframes only indicate the space within the selected area for simulation calculations and are unrelated to the structure of the metasurface or the cell itself.

[0062] It should be noted that each cell on the metasurface can be considered as a scatterer or a truncated waveguide, which can generate secondary waves. These waves interfere with each other, forming a specific phase distribution. Therefore, referring to... Figure 11As shown, the size of the cells also affects the light-gathering effect of the metasurface. Without considering factors such as structural resonance and manufacturing errors, through... Figure 11 (b) and Figure 11 The comparison in (d) shows that, with a fixed width, taller sub-units can provide a larger phase modulation range, thus achieving a greater phase delay and more precisely controlling the shape of the light wave. This results in better light-gathering properties for the metasurface. Furthermore, taller sub-units are more likely to achieve the desired phase gradient, thereby more effectively focusing light to the focal point. Figure 11 (a) Figure 11 (b) and Figure 11 The comparison in (c) shows that, with a fixed height, wider sub-units result in fewer sub-units that can be set within the same area. Therefore, wider sub-units reduce the spatial resolution of the metasurface, limiting the ability to finely control the light field. Simultaneously, the reduced spatial resolution also leads to less precise phase gradient changes between sub-units, resulting in weakened light-gathering characteristics. However, depending on other conditions, changes in height or width alone do not have a decisive impact on the light-gathering characteristics of the sub-units. Therefore, in actual production, a more balanced parameter needs to be found to achieve the optimal light-gathering effect.

[0063] Based on this, in some embodiments of this application, the metasurface can be described by a 2×2 Jones matrix or a 4×4 Mueller matrix, which respectively represent the polarization transformation and total polarization transformation of the incident light by the metasurface.

[0064] Specifically, for a metasurface composed of rotating nanocubes, its Jones matrix can be written as:

[0065]

[0066] Where θ is the orientation angle of the nanocube, and t o and t e These are the complex scattering coefficients along the fast and slow optical axes. The Jones vector of the emitted light can be calculated from this matrix, expressed as:

[0067] E S =J(θ)E i

[0068] Among them, E i It is the Jones vector of the incident light.

[0069] For a metasurface on a cylinder composed of rotating nanocubes, its Mueller matrix can be written as:

[0070]

[0071] The Stokes vector of the incident light can be calculated from this matrix, and is expressed as:

[0072] S'=M(θ)S

[0073] Where S is the Stokes vector of the incident light.

[0074] Based on the above matrix, in the actual design process, the design of metasurfaces can adopt a forward approach, such as "phase matching", which means determining the required phase delay of each elementary atom according to the desired output light wavefront, and optimizing the performance of the metasurface through numerical simulation or experiment.

[0075] Reference Figure 1 As shown, in some embodiments of this application, the light-emitting structure 10 further includes a passivation layer 500, a color conversion layer 600, a color filter layer 700, and a reflective layer 800. The passivation layer 500 is disposed on one side of the driving substrate 100 and covers the bonding layer 200 and the light source 300. A groove 501 is spaced apart on the side of the passivation layer 500 away from the driving substrate 100, and the color conversion layer 600 is disposed in the groove 501. The color filter layer 700 is disposed on the side of the color conversion layer 600 away from the driving substrate 100. In some embodiments of this application, the material of the passivation layer 500 may include SiO2, Al2O3, SiN, polyimide, or other photo-patternable polymers such as SU-8 photoresist.

[0076] To ensure the color conversion effect of the color conversion layer 600 on the light source 300, the groove 501 and the color conversion layer 600 have trapezoidal cross-sections, and the projection of the groove 501 on the driving substrate 100 overlaps with the projection of the bonding layer 200 on the driving substrate 100. Furthermore, a reflective layer 800 is disposed in the groove 501 and connected to the inner sidewall of the groove 501, as well as the outer wall of the color conversion layer 600. Through the inclined trapezoidal sidewalls, the reflective layer 800 can better focus the light emitted by the light source 300 into the color conversion layer 600.

[0077] In some embodiments of this application, the light source 300 is a blue light source 300, and the color conversion layer 600 includes red quantum dot material, green quantum dot material and transparent material, so as to convert red, green and blue light respectively.

[0078] Reference Figure 3As shown, in some other embodiments of this application, the light-emitting structure can be applied not only to quantum dot display devices but also to native micro-LED display devices. The light-emitting structure further includes a passivation layer 500 disposed on one side of the driving substrate 100 and covering the bonding layer 200 and the light source 300. A lens layer may also be disposed on the side of the passivation layer 500 away from the driving substrate 100. The projection of the lens layer onto the driving substrate overlaps with the projection of the bonding layer onto the driving substrate, thereby helping to improve the display brightness of the display device.

[0079] Reference Figure 12 and Figure 13 As shown, forming the photocontrol layer 400 on the bonding layer 200 further includes the following steps:

[0080] S1: Apply epitaxy (Epi) adhesive;

[0081] It should be noted that Epi glue is a key material layer used in epitaxy to manufacture optoelectronic devices such as light-emitting diodes (LEDs) and laser diodes. In the LED production process, epitaxy is used to grow multiple layers of semiconductor materials on a substrate, which form the active layer of the LED.

[0082] S2: Prepare a metal layer on Epi adhesive;

[0083] It should be noted that this metal layer is the main part of forming the bonding layer 200 and the photocontrol layer 400.

[0084] S3: Prepare a patterned PR adhesive layer on the metal layer;

[0085] S4: Perform holographic exposure, development, post-baking, ion beam etching, and cleaning on the material obtained in step S3 to pattern the metal layer.

[0086] It should be noted that the first groove 411 is formed in the patterned metal layer.

[0087] S5: Fill the first groove 411 with dielectric layer 420 to form a complete photocontrol layer 400 and bonding layer 200;

[0088] S6: Prepare a driving substrate 100 on one side of the bonding layer 200.

[0089] According to a second aspect of this application, a display panel is also provided, which includes the light-emitting structure 10 of any of the foregoing embodiments. Therefore, the display panel also has all the beneficial effects of the light-emitting structure 10 of this application, which will not be described again here.

[0090] In summary, although the present application has disclosed the preferred embodiments as described above, the above preferred embodiments are not intended to limit the present application. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the present application. Therefore, the scope of protection of the present application shall be determined by the scope defined in the claims.

Claims

1. A light emitting structure, characterized by The light-emitting structure comprises: a driving substrate; a bonding layer provided with a plurality of bonding layers arranged at intervals on one side of the driving substrate; and a light-emitting source arranged on the side of the bonding layer away from the driving substrate; wherein the side of the bonding layer close to the light-emitting source is provided with a light control layer, and the light control layer has a wavefront with a parabolic phase distribution.

2. The light-emitting structure according to claim 1, wherein the light control layer comprises: a metasurface layer connected with the bonding layer, and the metasurface layer comprises the same material as the bonding layer.

3. The light-emitting structure according to claim 2, wherein the metasurface layer comprises a plurality of cells arranged in at least one layer, and gaps are arranged between the cells; and the light control layer further comprises a dielectric layer fixed in the gaps.

4. The light-emitting structure according to claim 3, wherein the cells comprise any one or more of a combination of a solid of revolution, a prism and a prism.

5. The light-emitting structure according to claim 2, wherein the ratio of the thickness of the metasurface layer to the operating wavelength of the metasurface layer ranges from 0.1 to 0.

8.

6. The light-emitting structure according to claim 3, wherein the projection area of the bonding layer on the driving substrate is greater than the projection area of the light-emitting source on the driving substrate.

7. The light-emitting structure according to claim 6, wherein the light-emitting structure further comprises: a passivation layer arranged on one side of the driving substrate and covering the bonding layer and the light-emitting source; and the passivation layer comprises the same material as the dielectric layer.

8. The light-emitting structure according to claim 7, wherein the side of the passivation layer away from the driving substrate is provided with a plurality of grooves, and the grooves are used for at least accommodating quantum dot materials or transparent materials; the cross section of the grooves is in a trapezoidal structure, and the projection of the grooves on the driving substrate overlaps with the projection of the bonding layer on the driving substrate; the light-emitting structure further comprises a reflective layer fixedly connected with the inner side wall of the grooves, and the surface of the reflective layer is in direct contact with the quantum dot materials or transparent materials.

9. The light-emitting structure according to claim 7, wherein the light-emitting structure further comprises: a lens layer arranged on the side of the passivation layer away from the driving substrate, and the projection of the lens layer on the driving substrate overlaps with the projection of the bonding layer on the driving substrate. The light-emitting structure according to any one of claims 1 to 9.

10. A display panel, characterized by ​

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