Micro light emitting diode chip and display device

Abstract

The application provides a micro light emitting diode chip and a display device, and relates to the technical field of display. The micro light emitting diode chip comprises a substrate and a plurality of pixel units, the plurality of pixel units are arranged in an array on one side of the substrate, each pixel unit comprises at least one green micro light emitting diode chip and at least one blue micro light emitting diode chip, along a first direction, the green micro light emitting diode chip and the blue micro light emitting diode chip are sequentially arranged, the green micro light emitting diode chip is closer to the substrate than the blue micro light emitting diode chip, and the blue micro light emitting diode chip is located on at least part of the surface of the green micro light emitting diode chip away from the substrate, and the first direction is a direction perpendicular to the substrate. Therefore, the micro light emitting diode chip can realize at least multi-color display through wafer-level vertical stacking monolithic, the application scenarios are various, and the future product development prospect is great.

Description

Technical Field

[0001] This application relates to the field of displays, and more particularly to a micro light-emitting diode chip and a display device. Background Technology

[0002] With the continuous development of light emitting diode (LED) technology, micro light emitting diodes (Micro LEDs) have great application prospects in fields such as augmented reality (AR) glasses, virtual reality (VR) glasses, televisions, projectors, head-up displays (HUDs), digital vehicle lights, and embedded image displays due to their advantages such as high refresh rate, ultra-high definition, low power consumption, and long lifespan.

[0003] In related technologies, green can be displayed using a single green MicroLED chip. However, single green MicroLED chip displays only support a single shade of green, which greatly limits application scenarios and future product expansion prospects. Utility Model Content

[0004] This application provides a micro light-emitting diode chip and display device, which can achieve multi-color display by vertically stacking single wafers at the wafer level. It has a wide range of applications and great prospects for future product expansion.

[0005] In a first aspect, a micro light-emitting diode chip is provided, comprising: a substrate and a plurality of pixel units, wherein the plurality of pixel units are arranged in an array on one side of the substrate, and each pixel unit includes at least one green micro light-emitting diode chip and at least one blue micro light-emitting diode chip, wherein the green micro light-emitting diode chip and the blue micro light-emitting diode chip are arranged sequentially along a first direction, and the green micro light-emitting diode chip is closer to the substrate than the blue micro light-emitting diode chip, and the blue micro light-emitting diode chip is located on at least a portion of the surface of the green micro light-emitting diode chip on the side away from the substrate, wherein the first direction is a direction perpendicular to the substrate.

[0006] Because the above technical solution involves vertically stacking green and blue micro-light-emitting diode chips from bottom to top on one side of the substrate, it can provide multi-color displays other than red, thus providing a rich range of colors to meet basic daily display needs and offering more application scenarios. Moreover, the green and blue micro-light-emitting diode chips can be manufactured using existing mature green and blue chip processes, which are efficient and cost-effective, enabling mass production.

[0007] In some embodiments, each pixel unit includes a first sub-pixel unit and a second sub-pixel unit, the first sub-pixel unit and the second sub-pixel unit being spaced apart; the first sub-pixel unit includes at least one green micro-light-emitting diode chip and at least one blue micro-light-emitting diode chip, the second sub-pixel unit includes at least one color micro-light-emitting diode chip and at least one red quantum dot structure, the color micro-light-emitting diode chip including any one of only green micro-light-emitting diode chips, only blue micro-light-emitting diode chips, and a combination of green micro-light-emitting diode chips and blue micro-light-emitting diode chips; along a first direction, in each first sub-pixel unit, the green micro-light-emitting diode chip and the blue micro-light-emitting diode chip are arranged sequentially, and the green micro-light-emitting diode chip is closer to the substrate than the blue micro-light-emitting diode chip, the blue micro-light-emitting diode chip is located on at least a portion of the surface of the green micro-light-emitting diode chip on the side away from the substrate; along the first direction, in each second sub-pixel unit, the color micro-light-emitting diode chip and the red quantum dot structure are arranged sequentially, and the color micro-light-emitting diode chip is closer to the substrate than the red quantum dot structure, the red quantum dot structure is located on at least a portion of the surface of the color micro-light-emitting diode chip on the side away from the substrate.

[0008] In the above technical solution, a full-color display can be provided by vertically stacking green micro-light-emitting diode chips and blue micro-light-emitting diode chips from bottom to top on one side of the substrate, as well as blue micro-light-emitting diode chips and red quantum dot structures spaced apart from them. Moreover, the green micro-light-emitting diode chips and blue micro-light-emitting diode chips can be realized based on existing mature green and blue chip manufacturing processes, and red light emission is achieved by exciting red quantum dots through blue micro-light-emitting diode chips. There is no need to fabricate red micro-light-emitting diode chips separately. The process has low complexity, low cost, high efficiency and high yield, and is suitable for mass production. It has achieved a wafer-level vertically stacked monolithic full-color display.

[0009] In some embodiments, a first photoresist structure is disposed between any adjacent first sub-pixel unit and second sub-pixel unit. The first photoresist structure is in contact with the first sub-pixel unit and the second sub-pixel unit respectively. The first photoresist structure is used to block and reflect light.

[0010] In the above technical solution, a first photoresist structure is provided between any adjacent first sub-pixel unit and second sub-pixel unit. This first photoresist structure can play the roles of light blocking and preventing light leakage, thereby reducing light crosstalk and color mixing between any adjacent first sub-pixel units and second sub-pixel units and improving the contrast of full-color display. At the same time, by reducing the reflectivity of the interface to ambient light, glare interference can be reduced, especially in strong light environments, which can improve the visibility of full-color display.

[0011] In some embodiments, each pixel unit includes a first sub-pixel unit and a third sub-pixel unit; along a first direction, the first sub-pixel unit and the third sub-pixel unit are arranged sequentially, and the first sub-pixel unit is closer to the substrate than the third sub-pixel unit, while the third sub-pixel unit is located on a portion of the surface of the first sub-pixel unit facing away from the substrate; the first sub-pixel unit includes at least one green micro-light-emitting diode chip and at least one blue micro-light-emitting diode chip, and the third sub-pixel unit includes at least one second photoresist structure and at least one red quantum dot structure; along the first direction, in each first sub-pixel unit, the green micro-light-emitting diode chip and the blue micro-light-emitting diode chip are arranged sequentially, and the green micro-light-emitting diode chip is closer to the substrate than the blue micro-light-emitting diode chip, while the blue micro-light-emitting diode chip is located on at least a portion of the surface of the green micro-light-emitting diode chip facing away from the substrate; along a second direction, in each third sub-pixel unit, the red quantum dot structure is in contact with the second photoresist structure, and the second photoresist structure is used to block and reflect light; the second direction is a direction parallel to the substrate.

[0012] In the above technical solution, a full-color display can be provided by vertically stacking green micro-LED chips, blue micro-LED chips, horizontally arranged red quantum dot structures, and a second photoresist structure from bottom to top on one side of the substrate. At the same time, the second photoresist structure can play a role in shielding light and preventing light leakage, reducing light crosstalk and color mixing between the light emitted from the green and blue micro-LED chips and the light emitted from the red quantum dot structure, thereby improving the contrast of the full-color display. It can also reduce glare interference by reducing the reflectivity of the interface to ambient light, especially in strong light environments, thereby improving the visibility of the full-color display and further enhancing the display performance. In addition, the green and blue micro-LED chips can be realized based on existing mature green and blue chip manufacturing processes, which have efficient processes and low cost feasibility, and can achieve mass production.

[0013] In some embodiments, the number of second photoresist structures is one, and along the second direction, the second photoresist structure is located to the left or right of the red quantum dot structure; or, the number of second photoresist structures is two, and along the second direction, the red quantum dot structure is located between the two second photoresist structures.

[0014] In the above technical solution, the second photoresist structure can play the roles of light shielding and preventing light leakage, reducing light crosstalk and color mixing between any adjacent sub-pixel units, and improving the contrast of full-color display; at the same time, it can reduce glare interference by reducing the reflectivity of the interface to ambient light, and can improve the visibility of full-color display, especially in strong light environment.

[0015] In some embodiments, each pixel unit includes a fourth sub-pixel unit and a fifth sub-pixel unit. Along a first direction, the fourth sub-pixel unit and the fifth sub-pixel unit are arranged sequentially, with the fourth sub-pixel unit being closer to the substrate than the fifth sub-pixel unit. Each fifth sub-pixel unit is located on at least a portion of the surface of each fourth sub-pixel unit on the side facing away from the substrate. The fourth sub-pixel unit includes at least one green micro-light-emitting diode chip, and the fifth sub-pixel unit includes at least one blue micro-light-emitting diode chip, at least one red quantum dot structure, and at least one second photoresist structure. Along a second direction, one of the second photoresist structures in each fifth sub-pixel unit is located between the blue micro-light-emitting diode chip and the red quantum dot structure, and the blue micro-light-emitting diode chip, the second photoresist structure, and the red quantum dot structure are in contact. The second photoresist structure is used to block and reflect light. The second direction is a direction parallel to the substrate.

[0016] In the above technical solution, a full-color display can be provided by vertically stacking green micro-light-emitting diode chips and horizontally arranging blue micro-light-emitting diode chips, a red quantum dot structure, and a second photoresist structure on one side of the substrate from bottom to top. At the same time, the second photoresist structure can play a role in shielding light and preventing light leakage, reducing light crosstalk and color mixing between the light emitted from the green and blue micro-light-emitting diode chips and the light emitted from the red quantum dot structure, thereby improving the contrast of the full-color display. It can also reduce glare interference by reducing the reflectivity of the interface to ambient light, especially in strong light environments, thereby improving the visibility of the full-color display and further enhancing the display performance. In addition, the green and blue micro-light-emitting diode chips can be realized based on existing mature green and blue chip manufacturing processes, which have efficient processes and low cost feasibility, and can achieve mass production.

[0017] In some embodiments, each fifth sub-pixel unit includes a blue micro-LED chip, a second photoresist structure, and a red quantum dot structure, with the second photoresist structure located between the blue micro-LED chip and the red quantum dot structure; or, each fifth sub-pixel unit includes a blue micro-LED chip, two second photoresist structures, and a red quantum dot structure, with one second photoresist structure located between the blue micro-LED chip and the red quantum dot structure, and the other second photoresist structure located on the side of the red quantum dot structure away from the blue micro-LED chip.

[0018] In the above technical solution, the second photoresist structure can play the roles of light shielding and preventing light leakage, reducing light crosstalk and color mixing between any adjacent sub-pixel units, and improving the contrast of full-color display; at the same time, it can reduce glare interference by reducing the reflectivity of the interface to ambient light, and can improve the visibility of full-color display, especially in strong light environment.

[0019] In some embodiments, a first photoresist structure is provided between any two adjacent pixel units, the first photoresist structure is in contact with the pixel unit, and the first photoresist structure is used to block and reflect light.

[0020] In the above technical solution, by setting a second photoresist structure between any two adjacent pixel units, the second photoresist structure can play the roles of light blocking and preventing light leakage, reducing light crosstalk and color mixing between any two adjacent pixels, and improving the contrast of full-color display; at the same time, by reducing the reflectivity of the interface to ambient light, glare interference can be reduced, especially in strong light environments, the visibility of full-color display can be improved.

[0021] In some embodiments, each green micro-light-emitting diode chip and each blue micro-light-emitting diode chip are provided with a size of less than 200 μm.

[0022] In the above technical solution, each micro LED chip is relatively small in size.

[0023] In a second aspect, a display device is provided, comprising the micro light-emitting diode chip of the first aspect.

[0024] It is understandable that the beneficial effects of the second aspect mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here. Attached Figure Description

[0025] Figure 1 The diagram illustrates a display device for AR glasses provided in some embodiments of this application;

[0026] Figure 2 The diagram shows the structure of the lens and green Micro LED chip in AR glasses in the relevant technology;

[0027] Figure 3 The diagram shows the structure of the lens, X-cube, and Micro LED chip in AR glasses in related technologies;

[0028] Figure 4 The diagram shows the structure of the lens and Micro LED chip in the AR glasses of the related technology;

[0029] Figure 5 The present application shows structural diagrams of micro light-emitting diode chips in some embodiments;

[0030] Figure 6 The present application shows structural diagrams of micro light-emitting diode chips in some embodiments;

[0031] Figure 7 The present application shows structural diagrams of micro light-emitting diode chips in some embodiments;

[0032] Figure 8 The present application shows structural diagrams of micro light-emitting diode chips in some embodiments;

[0033] Figure 9 The present application shows structural diagrams of micro light-emitting diode chips in some embodiments;

[0034] Figure 10 The present application shows structural diagrams of micro light-emitting diode chips in some embodiments;

[0035] Figure 11 The present application shows structural diagrams of micro light-emitting diode chips in some embodiments;

[0036] Figure 12 The present application shows structural diagrams of micro light-emitting diode chips in some embodiments;

[0037] Figure 13 The present application shows structural diagrams of micro light-emitting diode chips in some embodiments;

[0038] Figure 14 The present application shows structural diagrams of micro light-emitting diode chips in some embodiments;

[0039] Figure 15 The present application shows structural diagrams of micro light-emitting diode chips in some embodiments;

[0040] Figure 16 The present application shows structural diagrams of micro light-emitting diode chips in some embodiments;

[0041] Figure 17 The present application shows structural diagrams of micro light-emitting diode chips in some embodiments;

[0042] Figure 18 The diagram shows a structural diagram of a micro light-emitting diode chip in some embodiments of this application.

[0043] The following are the labeling elements in the figure:

[0044] 100-, 1-Lens, 2-Micro LED chip, 21-Substrate, 20-Red Micro LED chip, 22-Green Micro LED chip, 23-Blue Micro LED chip, 24-Red quantum dot structure, 251-First photoresist structure, 252-Second photoresist structure, 4-X-cube, D-Pixel unit, D1-First sub-pixel unit, D2-Second sub-pixel unit, D3-Third sub-pixel unit, D4-Fourth sub-pixel unit, D5-Fifth sub-pixel unit. Detailed Implementation

[0045] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0046] In the description of the embodiments of this application, the term "at least one" refers to one or more, and "more than one" refers to two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of a single item or a plurality of items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be a single item or multiple items.

[0047] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on or indirectly on the other component. When a component is referred to as "connected to" another component, it can be directly connected to or indirectly connected to the other component.

[0048] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can also refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0049] It should be understood that "electrical connection" in the embodiments of this application can be understood as physical contact and electrical conduction between components, or as the form of connection between different components in the circuit structure through a physical line that can transmit electrical signals.

[0050] In the description of the embodiments of this application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0051] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0052] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature.

[0053] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments in any suitable manner.

[0054] This application does not limit the specific type of display device. The display device can be implemented in various ways, such as AR glasses, VR glasses, television (specifically, smart TV), projector, HUD, digital car lights, and embedded image display, etc.

[0055] Figure 1 A schematic diagram of an AR glasses 100 provided in some embodiments of this application is shown. For example... Figure 1 As shown, the AR glasses 100 may include a lens 1 and a Micro LED chip 2, with the lens 1 positioned on the light-emitting side of the Micro LED chip 2. It can be understood that the light-emitting side of the Micro LED chip 2 refers to the side of the Micro LED chip 2 that emits light.

[0056] Figure 2 A structural diagram of the lens 1 and the green Micro LED chip 22 of the AR glasses 100 in the related technology is shown. Figure 2 It is a single green MicroLED chip display.

[0057] like Figure 2 As shown, lens 1 is positioned on the light-emitting side of green Micro LED chip 22. Green Micro LED chip 22 can generate green light, which is emitted from lens 1 to achieve green display.

[0058] The advantages of a single green MicroLED chip display are: 1. Outstanding brightness and efficiency: The quantum efficiency of green MicroLED chips is higher than that of red MicroLED chips, enabling ultra-high brightness (e.g., brightness exceeding 1 million nits), suitable for outdoor and high ambient light scenarios (e.g., HUD, projectors); 2. High technological maturity, no need for multi-color integration and complex optical systems, simple manufacturing process, low cost and complexity, mass production is possible, and the cost is also low.

[0059] However, single-green MicroLED chip displays also have many disadvantages: 1. Limited color: Only supports single green information display, limiting application scenarios; 2. Poor functional expandability: Cannot achieve dynamic color adjustment through color conversion or color mixing, making it difficult to adapt to multiple scenario needs such as full-color display.

[0060] Figure 3 The diagram shows the structure of the lens 1, the color-combining prism (X-cube), and the Micro LED chip of the AR glasses 100 in the related technology. Figure 3 Full-color display for X-cube.

[0061] like Figure 3 As shown, lens 1 is positioned on the light-emitting side of the assembly consisting of the Micro LED chip and X-cube 4. The Micro LED chip includes a green Micro LED chip 22, a blue Micro LED chip 23, and a red Micro LED chip 20. The green Micro LED chip 22 is positioned on the side of X-cube 4 facing away from lens 1, the blue Micro LED chip 23 is positioned on the right side of X-cube 4, and the red Micro LED chip 20 is positioned on the left side of X-cube 4. This uses Micro LED chips with red, green, and blue light as the light source, and the X-cube 4 combines the three colors to produce colored light. This colored light is emitted from lens 1, achieving full-color display.

[0062] The advantages of X-cube full-color display are: 1. Simple implementation: It uses Micro LED chips with red, green and blue light to optically combine colors with X-cube prisms, a mature technology; 2. High brightness and wide color gamut: Red, green and blue light are driven independently, and brightness can be optimized separately (for example, red light brightness can reach 100,000 nits and green light brightness can reach 500,000 nits), and the color gamut coverage can reach 133% of sRGB, which can present rich colors; 3. Flexible modular design: Red, green and blue light can be prepared, replaced and upgraded separately, etc., with low maintenance costs.

[0063] However, X-cube full-color displays also have many disadvantages: 1. Large size and weight: X-cube prisms require multiple panels to be spliced ​​together, which increases the size of the optical engine and makes it difficult to meet the lightweight requirements of display devices; 2. Significant light efficiency loss: There is light loss during the color mixing process of X-cube prisms, resulting in low overall energy efficiency and high power consumption; 3. High cost: It requires three sets of driving circuits and precision optical calibration, etc., and the comprehensive cost is as high as 3 to 5 times that of a single green MicroLED chip display.

[0064] Figure 4 The diagram shows the structure of the lens 1 and the Micro LED chip of the AR glasses 100 in the related technology. Figure 4 Full-color display for wafer-level vertical stacking packaging (WLVSP).

[0065] like Figure 4 As shown, lens 1 is positioned on the light-emitting side of the Micro LED chip. From the direction closest to lens 1 to the direction furthest from lens 1, the Micro LED chip sequentially includes a blue Micro LED chip 23, a green Micro LED chip 22, and a red Micro LED chip 20. These three Micro LED chips, representing red, green, and blue light, serve as a light source to generate colored light, which is emitted from lens 1, achieving full-color display.

[0066] The advantages of WLVSP full-color display are: 1. Ultra-high brightness and wide color gamut: The sub-pixels of red, green and blue light emit light independently, and the brightness superposition effect of a single pixel is significant; 2. Superior pixel density and size: The Micro LED chips of red, green and blue light are integrated on the same driving backplane, eliminating the need for beam splitters or mass transfer, compressing the pixel pitch, improving resolution, and making the optical engine small and suitable for lightweight display devices; 3. Process compatibility and cost potential: The manufacturing process is compatible with existing processes, the process is simple, and the cost is low.

[0067] However, WLVSP full-color display also has many disadvantages: 1. High manufacturing process complexity and material mismatch: The red Micro LED chip 20 generally uses the aluminum gallium indium phosphide (AlGaInP) material system, while the green Micro LED chip 22 and blue Micro LED chip 23 usually use the gallium nitride (GaN) material system. The lattice constants of AlGaInP and GaN are different, which makes it easy to generate defects when stacking epitaxial layers. Buffer layers or strain layers need to be introduced, resulting in low yield and high cost; 2. Complex driving circuit design: Each LED chip layer needs to be designed with independent electrodes and current control, etc. The increased density of pixel-level driving circuits easily causes crosstalk, leading to increased power consumption; 3. Heat dissipation and reliability issues: The concentrated heat density easily causes temperature stacking, and high temperature accelerates quantum well degradation; 4. The AlGaInP material system is different from the GaN material system, which means that the red, green and blue Micro LED chips cannot be realized by in-situ growth. They can only be made by wafer bonding process. The wafer bonding process for red, green and blue is very complex, and the bonding difficulty of different material systems is also very high, resulting in low mass production feasibility.

[0068] It is evident that various AR glasses solutions have been provided through the design of Micro LED chip structure and position, but each solution has its own set of problems.

[0069] Therefore, in order to enable AR glasses and other display devices to have full-color display effects while being simple and easy to implement, this application provides a micro light-emitting diode chip. This micro light-emitting diode chip can provide at least multi-color display by vertically stacking at least green micro light-emitting diode chips and blue micro light-emitting diode chips on a substrate. Moreover, the green and blue chips can be realized based on existing mature processes, with many application scenarios and great prospects for future expansion.

[0070] To facilitate a further understanding of the technical solutions in some embodiments of this application, the technical solutions of the micro-light-emitting diode chip and display device, and how these solutions solve the aforementioned technical problems, are described in detail below with reference to specific embodiments and accompanying drawings. Each embodiment can be combined with others, and the same or similar concepts or processes may not be repeated in some embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this application.

[0071] Example 1 ( Figure 5 )

[0072] Figure 5 The diagram shows a structural diagram of a micro light-emitting diode chip in some embodiments of this application.

[0073] like Figure 5As shown, this embodiment provides a micro light-emitting diode chip (hereinafter referred to as Micro LED chip), which may include: a substrate 21 and a plurality of pixel units D, wherein the plurality of pixel units D are arranged in an array on one side of the substrate 21.

[0074] Each pixel unit D includes at least one green micro light emitting diode (G Micro LED) chip 22 and at least one blue micro light emitting diode (B Micro LED) chip 23.

[0075] Along the first direction ( Figure 5 In the oz direction), G Micro LED chip 22 and B Micro LED chip 23 are arranged sequentially. G Micro LED chip 22 is closer to substrate 21 than B Micro LED chip 23. One G Micro LED chip 22 is in contact with substrate 21. Each B Micro LED chip 23 is located on at least a portion of the surface of each G Micro LED chip 22 on the side away from substrate 21.

[0076] It should be noted that the oz direction is perpendicular to the substrate 21.

[0077] Because the epitaxial layer (e.g., indium gallium nitride (InGaN) quantum well) of the G Micro LED chip 22 has a strong absorption of blue light, if the G Micro LED chip 22 is placed above the B Micro LED chip 23, the blue light emitted by the B Micro LED chip 23 needs to penetrate the upper G Micro LED chip 22 before it can be emitted. However, the absorption rate of blue light (short wavelength) by the InGaN quantum well in the G Micro LED chip 22 is significantly higher than the absorption rate of green light (long wavelength) by the epitaxial layer (e.g., gallium nitride (GaN) quantum well) of the B Micro LED chip 23, resulting in a significant attenuation of blue light energy, which cannot be effectively mixed with green light. Moreover, when blue light passes through the green light layer, some energy may also be absorbed by the electrodes, encapsulation layer, etc. in the G Micro LED chip 22, resulting in insufficient intensity of emitted blue light, which cannot form a uniform color mixture with green light, and may even only display green light due to the weakness of blue light. Therefore, in this embodiment, the B Micro LED chip 23 is positioned above the G Micro LED chip 22. Since the GaN quantum well of the B Micro LED chip 23 has weak absorption of green light, the green light emitted by the G Micro LED chip 22 located below can penetrate the B Micro LED chip 23 located above and be emitted together with the blue light, thus achieving a good multi-color display.

[0078] In the embodiments of this application, the material of the substrate 21 can be any one of sapphire, silicon (Si) or silicon carbide (SiC).

[0079] Furthermore, sapphire can be chosen as the material for substrate 21. Sapphire is not easily corroded in high-temperature and acid / alkali environments, making it suitable for high-temperature epitaxial growth processes and ensuring the stability of semiconductor layers such as InGaN and GaN. Simultaneously, sapphire has high transmittance in the ultraviolet to near-infrared band (approximately 200nm-2500nm), while exhibiting almost no absorption in the green light (approximately 520nm) emitted by the G Micro LED chip 22 and the blue light (approximately 450nm) emitted by the B Micro LED chip 23, ensuring efficient light output. Moreover, sapphire has high surface flatness, resulting in smooth surfaces for epitaxially grown GaN and other semiconductor layers, reducing light scattering losses at interfaces and improving light extraction efficiency. In addition, the process of fabricating substrate 21 using sapphire is mature and cost-effective, and it is compatible with vertically structured Micro LED chips, making it highly suitable for display devices such as AR glasses and VR glasses.

[0080] The substrate 21 can be any one of a mature integrated circuit complementary metal oxide semiconductor (CMOS) driving backplane or a thin film transistor (TFT) driving backplane.

[0081] Furthermore, substrate 21 can be selected as a CMOS driving backplane. The CMOS driving backplane can realize active addressing of pixels and can have various circuits such as timer control register (TCON) and overcurrent protection (OCP). In addition, it can also achieve lightweight design. All of these features make the micro-display technology combining the CMOS driving backplane and MicroLED chip compatible with semiconductor processes, suitable for mass production, and well-suited for use in near-eye display devices such as AR glasses and VR glasses.

[0082] The following explanations will all take substrate 21 as an example of a CMOS driving backplane.

[0083] It should be understood that each pixel unit D includes at least one G Micro LED chip 22 and at least one B Micro LED chip 23. Along the oz direction, the G Micro LED chip 22 is in contact with the substrate 21, and the G Micro LED chip 22 and B Micro LED chip 23 are arranged sequentially. The fact that each B Micro LED chip 23 is located on at least a portion of the surface of each G Micro LED chip 22 on the side facing away from the substrate 21 means: Figure 5As shown, the Micro LED chip includes six pixel units D, each pixel unit D including a G Micro LED chip 22 and a B Micro LED chip 23. In this case, the G Micro LED chip 22 is located between the substrate 21 and the B Micro LED chip 23, and the B Micro LED chip 23 is located on the entire surface of the G Micro LED chip 22 facing away from the substrate 21. Alternatively, the Micro LED chip may include at least one pixel unit D, each pixel unit D including a G Micro LED chip 22 and a B Micro LED chip 23. In this case, the G Micro LED chip 22 is located between the substrate 21 and the B Micro LED chip 23, and the B Micro LED chip 23 is located on a portion of the surface of the G Micro LED chip 22 facing away from the substrate 21. The remaining portion of the surface of the G Micro LED chip 22 facing away from the substrate 21 is not provided with any structure. This is not specifically limited here.

[0084] Alternatively, the Micro LED chip may include at least one pixel unit D, and each pixel unit D may include multiple G Micro LED chips 22 and multiple B Micro LED chips 23. In this case, along the oz direction, the G Micro LED chips 22 are in contact with the substrate 21, and the G Micro LED chips 22 and B Micro LED chips 23 are arranged sequentially. Each B Micro LED chip 23 is located on the entire surface of each G Micro LED chip 22 on the side facing away from the substrate 21. Of course, the Micro LED chip may also include at least one pixel unit D, and each pixel unit D may include multiple G Micro LED chips 22 and multiple B Micro LED chips 23. In this case, along the oz direction, the G Micro LED chips 22 are in contact with the substrate 21, and the G Micro LED chips 22 and B Micro LED chips 23 are arranged sequentially. Each B Micro LED chip 23 is located on a portion of the surface of each G Micro LED chip 22 on the side facing away from the substrate 21. The remaining portion of the surface of a G Micro LED chip 22 on the side facing away from the substrate 21 is not provided with any structure. This is not specifically limited here.

[0085] It should be noted that, when each pixel unit D includes multiple G Micro LED chips 22 and multiple B Micro LED chips 23, it is further possible to select an even number of G Micro LED chips 22 and an even number of B Micro LED chips 23 per pixel unit D. This can improve the efficiency of co-emission of green and blue light, thereby better realizing multi-color display. In practical applications, the number of G Micro LED chips 22 and B Micro LED chips 23 in each pixel unit D can be determined according to the size of the Micro LED chips and the required functions.

[0086] In the embodiments of this application, the size of each G Micro LED chip 22 and the size of each B Micro LED chip 23 can be less than 200μm.

[0087] Along the oz direction, starting from near substrate 21, each Micro LED chip may include a first electrode, an epitaxial wafer, and a second electrode stacked sequentially. The first electrode may be an N-type electrode, in which case the second electrode may be a P-type electrode; alternatively, the first electrode may be a P-type electrode, in which case the second electrode may be an N-type electrode, depending on the specific application. The N-type electrode can be made of a metal, such as indium tin oxide (ITO), chromium / platinum / gold (Cr / Pt / Au), titanium / gold (Ti / Au), or titanium / silver / indium tin oxide (Ti / Ag / ITO). The P-type electrode can also be made of a metal, such as copper (Cu), tin (Sn), silver (Ag), Au, or indium (In).

[0088] Along the oz direction, starting from near the substrate 21, the epitaxial wafer generally includes an electron injection layer, a light-emitting layer, and a hole injection layer stacked sequentially. The light-emitting layer is the light-emitting region of the epitaxial wafer, capable of confining charge carriers; the material of the light-emitting layer can be a multi-quantum well, etc. The electron injection layer provides electrons and serves as the N-region of the light-emitting layer; the material of the electron injection layer can be any of GaN, gallium phosphide (GaP), or zinc oxide (ZnO). The hole injection layer provides holes and serves as the P-region of the light-emitting layer; the material of the hole injection layer can also be any of GaN, GaP, or ZnO.

[0089] Building upon the above, the epitaxial wafer may further include other layers, such as an electron blocking layer and a hole blocking layer. Thus, the electron blocking layer can be disposed between the light-emitting layer and the hole injection layer, and can be used to prevent electrons from leaking into the P-region of the light-emitting layer, thereby increasing the recombination rate of electrons and holes in the light-emitting recombination region. Similarly, the hole blocking layer can be disposed between the light-emitting layer and the electron injection layer, and can be used to prevent holes from leaking into the N-region of the light-emitting layer, thereby increasing the recombination rate of electrons and holes in the light-emitting recombination region.

[0090] Specifically, the G Micro LED chip 22 may include: a P electrode, a P-type GaN, an AlGaN electron blocking layer, a green quantum well layer, an N-type GaN layer, and an N electrode, which are stacked sequentially along the oz direction and starting from the substrate 21.

[0091] Specifically, the B Micro LED chip 23 may include: along the oz direction and starting from the substrate 21, a P electrode, a P-type GaN, an AlGaN electron blocking layer, a blue quantum well layer, an N-type GaN layer, and an N electrode are stacked sequentially; or, an N electrode, an N-type GaN, a blue quantum well layer, an AlGaN electron blocking layer, a P-type GaN layer, and a P electrode.

[0092] Please refer to this again. Figure 5 Here, for any two adjacent pixel units D, along the second direction ( Figure 5 The spacing w1 in the ox direction is not specifically limited. For example, when the size of a single chip is less than 50μm, w1 can be 5μm-100μm. Furthermore, w1 can be selected as 10μm-30μm, that is, w1 can be 10μm, 15μm, 20μm, 25μm, or 30μm, etc. This allows for the formation of a thermal buffer region using air, accelerating the thermal diffusion of the Micro LED chip; simultaneously, it reduces mechanical stress during temperature changes and lowers crosstalk; furthermore, it is compatible with current chip fabrication processes.

[0093] It should be noted that the ox direction is parallel to the substrate 21, that is, the ox direction is perpendicular to the oz direction.

[0094] As an example, in this embodiment, GaN-based green epitaxial wafers and GaN-based blue epitaxial wafers can be grown on different sapphire substrates first; then, the green epitaxial wafers and blue epitaxial wafers can be bonded to a CMOS driver backplane in sequence; finally, the chip structure can be etched and packaged to obtain the monolithic multicolor Micro LED chip in this embodiment.

[0095] As another example, in this embodiment of the application, GaN-based green epitaxial wafers and GaN-based blue epitaxial wafers can be grown in situ on the same sapphire substrate in sequence; finally, the chip structure is etched out and packaged to obtain the monolithic multicolor Micro LED chip in this embodiment of the application.

[0096] This application provides a micro LED chip, which consists of G Micro LED chips and B Micro LED chips vertically stacked from bottom to top on one side of a substrate. These two different colored Micro LED chips can provide multi-color displays other than red, thus providing a rich color palette to meet basic daily display needs and offering more application scenarios. Moreover, both the G Micro LED chips and the B Micro LED chips use GaN material systems and can be grown in situ or achieved through wafer bonding. The wafer bonding process is simple and easy to bond with the same material system. In other words, the G Micro LED chips and B Micro LED chips can be realized based on existing mature green and blue chip manufacturing processes, which has efficient processes and low cost feasibility, enabling mass production and facilitating industrial production and application.

[0097] In some embodiments, the micro light-emitting diode chip in this application may further include a first photoresist structure, which is disposed between any two adjacent pixel units D and is in contact with the two pixel units D. The first photoresist structure is used to block and reflect light.

[0098] This application provides a micro LED chip. By setting a first photoresist structure between any two adjacent pixel units, the first photoresist structure can play a role in blocking light and preventing light leakage, reducing light crosstalk and color mixing between any two adjacent pixels, and improving the contrast of full-color display. At the same time, the first photoresist structure can reduce glare interference by reducing the reflectivity of the interface to ambient light, especially in strong light environments, which can improve the visibility of full-color display and further improve the display performance of Micro LED chip.

[0099] Example 2 ( Figures 6 to 11 )

[0100] Figure 6 The diagram shows a structural diagram of a micro light-emitting diode chip in some embodiments of this application.

[0101] like Figure 6 As shown, this embodiment provides a Micro LED chip, which may include: a substrate 21 and a plurality of pixel units D, wherein the plurality of pixel units D are arranged in an array on one side of the substrate 21.

[0102] Each pixel unit D includes a first sub-pixel unit D1 and a second sub-pixel unit D2. The first sub-pixel unit D1 and the second sub-pixel unit D2 are separate and spaced apart. The first sub-pixel unit D1 includes at least one G Micro LED chip 22 and at least one B Micro LED chip 23. The second sub-pixel unit D2 includes at least one B Micro LED chip 23 and at least one red quantum dot structure 24.

[0103] Along the oz direction, the G Micro LED chip 22 and B Micro LED chip 23 in each first sub-pixel unit D1 are arranged sequentially. The G Micro LED chip 22 is closer to the substrate 21 than the B Micro LED chip 23. One G Micro LED chip 22 is in contact with the substrate 21. Each B Micro LED chip 23 is located on at least a portion of the surface of each G Micro LED chip 22 on the side away from the substrate 21.

[0104] Along the oz direction, the B Micro LED chip 23 and the red quantum dot structure 24 in each second sub-pixel unit D2 are arranged sequentially. The B Micro LED chip 23 is closer to the substrate 21 than the red quantum dot structure 24. One B Micro LED chip 23 is in contact with the substrate 21, and each red quantum dot structure 24 is located on at least a portion of the surface of the B Micro LED chip 23 on the side away from the substrate 21.

[0105] It should be noted that the G Micro LED chip 22 and B Micro LED chip 23 in the first sub-pixel unit D1 in this embodiment can refer to the above embodiment, and will not be repeated here.

[0106] In applications, the red quantum dots in the red quantum dot structure can include cadmium-based quantum dots (e.g., cadmium selenide / zinc sulfide (CdSe / ZnS) core-shell structure), cadmium-free quantum dots (e.g., indium phosphide / zinc sulfide (InP / ZnS) core-shell structure, copper indium sulfide / zinc sulfide (CuInS2 / ZnS)), or perovskite quantum dots, etc.

[0107] In each second sub-pixel unit D2 of this application embodiment, the B Micro LED chip 23 (wavelength approximately 430nm-480nm) emits blue light after being powered on. The blue light is transmitted upward along the oz direction to the red quantum dot structure 24. The absorption spectrum of the red quantum dots in the red quantum dot structure 24 can cover the emission wavelength of the B Micro LED chip 23, allowing the blue light photons to be absorbed by the quantum dots. At this time, electrons are excited from the valence band to the conduction band, forming excitons. When the excitons recombine, they release energy and emit red light. That is, the blue light of the B Micro LED chip 23 can be used to excite the red quantum dots in the red quantum dot structure 24, and red light emission can be achieved through the quantum confinement effect.

[0108] The spacing w2 along the ox direction between any two adjacent first sub-pixel units D1 and second sub-pixel units D2 is not specifically limited. For example, when the size of a single chip is less than 50μm, w2 can be 5μm-100μm. Further, w2 can be selected as 10μm-30μm, that is, w2 can be 10μm, 15μm, 20μm, 25μm, or 30μm, etc. Thus, a thermal buffer region can be formed using air or similar materials to accelerate the thermal diffusion of the Micro LED chip; at the same time, it can also reduce mechanical stress during temperature changes and reduce crosstalk; furthermore, it is compatible with current chip fabrication processes.

[0109] As an example, in this embodiment, GaN-based green epitaxial wafers and GaN-based blue epitaxial wafers can be grown on different sapphire substrates first; then, the green and blue epitaxial wafers can be bonded to a CMOS driver backplane in sequence; then, the chip structure can be etched; finally, red quantum dots can be formed on the B Micro LED chip 23 (which does not have the G Micro LED chip 22) and packaged to obtain the monolithic full-color Micro LED chip in this embodiment.

[0110] As another example, in this embodiment, GaN-based green epitaxial wafers and GaN-based blue epitaxial wafers can be grown in situ on the same sapphire substrate in sequence; then, the chip structure can be etched; finally, red quantum dots can be formed on the B Micro LED chip 23, which does not have the G Micro LED chip 22, and the chip can be packaged to obtain the monolithic full-color Micro LED chip in this embodiment.

[0111] It should be noted that the epitaxial growth processes of the GaN-based green epitaxial wafer and the GaN-based blue epitaxial wafer in the embodiments of this application are both mature GaN processes for sapphire substrates. However, the red light of the vertically stacked red (Red, R), G and B monolithic full-color technology in related technologies uses gallium arsenide (GaAs) technology, which makes it impossible to grow the RMicro LED chip in situ. It can only be obtained by bonding. This makes the epitaxial growth process of the RGB monolithic full-color technology in related technologies complex and costly.

[0112] This application provides a micro-light-emitting diode chip. A first sub-pixel unit is formed by vertically stacking G Micro LED chips and B Micro LED chips from bottom to top on one side of a substrate. A second sub-pixel unit is formed by vertically stacking B Micro LED chips and a red quantum dot structure from bottom to top on one side of the substrate. The first and second sub-pixel units are spaced apart and together form a single pixel unit. The combination of these two different colored Micro LED chips with the red quantum dot structure can provide full-color display, offering a rich array of colors suitable for a wide range of applications. Furthermore, the G Micro LED chips and B Micro LED chips can be fabricated using existing mature green and blue chip manufacturing processes. Red light emission is achieved by exciting the red quantum dots with the B Micro LED chips, eliminating the need for additional red Micro LED chips. This process is less complex, lower in cost, more efficient, and yields higher production rates, making it suitable for mass production. It effectively realizes wafer-level vertically stacked monolithic full-color display, which is beneficial for industrial production and application.

[0113] In some embodiments, Figure 7 The diagram shows a structural diagram of a micro-light-emitting diode chip in some embodiments of this application. For example... Figure 7 As shown, Figure 7 and Figure 6 The difference is: Figure 7 In the second sub-pixel unit D2, each red quantum dot structure 24 is located on at least a portion of the surface of the GMicro LED chip 22 on the side opposite to the substrate 21.

[0114] In the application, in each second sub-pixel unit D2, the G Micro LED chip 22 (wavelength approximately 520nm-530nm) emits green light when powered on. This green light travels upwards along the oz direction to the red quantum dot structure 24. The absorption spectrum of the red quantum dots in the red quantum dot structure 24 covers the emission wavelength of the G Micro LED chip 22, allowing the green photons to be absorbed by the quantum dots. At this point, electrons are excited from the valence band to the conduction band, forming excitons. When the excitons recombine, they release energy and emit red light. In other words, the green light from the G Micro LED chip 22 can be used to excite the red quantum dots in the red quantum dot structure 24, achieving red light emission through the quantum confinement effect.

[0115] This application provides a micro-light-emitting diode chip. A first sub-pixel unit is formed by vertically stacking G Micro LED chips and B Micro LED chips from bottom to top on one side of a substrate. A second sub-pixel unit is formed by vertically stacking G Micro LED chips and a red quantum dot structure from bottom to top on one side of the substrate. The first and second sub-pixel units are spaced apart and together form a single pixel unit. The combination of these two different colored Micro LED chips with the red quantum dot structure can provide full-color display, offering a rich array of colors suitable for a wide range of applications. Furthermore, the G Micro LED chips and B Micro LED chips can be fabricated using existing mature green and blue chip manufacturing processes. Red light emission is achieved by exciting the red quantum dots with the G Micro LED chips, eliminating the need for additional red Micro LED chips. This process is less complex, lower in cost, more efficient, and yields higher output, making it suitable for mass production. It effectively realizes wafer-level vertically stacked monolithic full-color display, which is beneficial for industrial production and application.

[0116] In some embodiments, Figure 8 The diagram shows a structural diagram of a micro-light-emitting diode chip in some embodiments of this application. For example... Figure 8 As shown, Figure 8 and Figure 6 The difference is: Figure 8 In the second sub-pixel unit D2, each red quantum dot structure 24 is located on at least a portion of the surface of the overall structure composed of G Micro LED chip 22 and B Micro LED chip 23 facing away from the substrate 21, at which time G Micro LED chip 22 is disposed between the substrate 21 and B Micro LED chip 23.

[0117] In applications, the number of G Micro LED chips 22 and B Micro LED chips 23 in the second sub-pixel unit D2 is not specifically limited; the number of both G Micro LED chips 22 and B Micro LED chips 23 can be at least one. When there are multiple G Micro LED chips 22 and B Micro LED chips 23, they are arranged sequentially along the oz direction, starting from contact with the substrate 21.

[0118] This application provides a micro-light-emitting diode chip. A first sub-pixel unit is formed by vertically stacking G Micro LED chips and B Micro LED chips from bottom to top on one side of a substrate. A second sub-pixel unit is formed by vertically stacking G Micro LED chips, B Micro LED chips, and a red quantum dot structure from bottom to top on one side of the substrate. The first and second sub-pixel units are spaced apart and together form a single pixel unit. The combination of these two different colored Micro LED chips with the red quantum dot structure can provide full-color display, offering a rich array of colors suitable for a wide range of applications. Furthermore, the G Micro LED chips and B Micro LED chips can be fabricated using existing mature green and blue chip manufacturing processes. Red light emission is achieved by jointly exciting the red quantum dots using the G Micro LED chips and B Micro LED chips, eliminating the need for additional red Micro LED chips. This process is less complex, lower in cost, more efficient, and yields higher production rates, making it suitable for mass production. It effectively realizes wafer-level vertically stacked monolithic full-color display, which is beneficial for industrial production and application.

[0119] In some embodiments, Figure 9 The diagram shows a structural diagram of a micro-light-emitting diode chip in some embodiments of this application. For example... Figure 9 As shown, Figure 9 and Figure 6 The difference is that the micro light-emitting diode chip also includes a first photoresist structure 251. The first photoresist structure 251 is disposed between any adjacent first sub-pixel unit D1 and second sub-pixel unit D2. The first photoresist structure 251 is in contact with the first sub-pixel unit D1 and the second sub-pixel unit D2 respectively. The first photoresist structure 251 is used to block and reflect light.

[0120] Figure 10 The diagram shows a structural diagram of a micro-light-emitting diode chip in some embodiments of this application. For example... Figure 10 As shown, Figure 10 and Figure 7The difference is that the micro light-emitting diode chip also includes a first photoresist structure 251. The first photoresist structure 251 is disposed between any adjacent first sub-pixel unit D1 and second sub-pixel unit D2. The first photoresist structure 251 is in contact with the first sub-pixel unit D1 and the second sub-pixel unit D2 respectively. The first photoresist structure 251 is used to block and reflect light.

[0121] Figure 11 The diagram shows a structural diagram of a micro-light-emitting diode chip in some embodiments of this application. For example... Figure 11 As shown, Figure 11 and Figure 8 The difference is that the micro light-emitting diode chip also includes a first photoresist structure 251. The first photoresist structure 251 is disposed between any adjacent first sub-pixel unit D1 and second sub-pixel unit D2. The first photoresist structure 251 is in contact with the first sub-pixel unit D1 and the second sub-pixel unit D2 respectively. The first photoresist structure 251 is used to block and reflect light.

[0122] In applications, the aforementioned first photoresist structure 251 can be a black matrix (BM), etc. The material of the first photoresist structure 251 can be a low-reflectivity material, such as an organic resin containing carbon black or metal oxides. In this case, the reflectivity of the first photoresist structure 251 can be as low as 5% or less, while maintaining high light-blocking properties. Furthermore, the first photoresist structure 251 can be a structure combining an ultrathin metal layer and a resin layer. In this case, the reflectivity of the first photoresist structure 251 can be as low as 1% or less, while maintaining high light-blocking properties.

[0123] This application provides a micro LED chip. By setting a first photoresist structure between any two adjacent first and second sub-pixel units, the first photoresist structure can block light and prevent light leakage, reducing light crosstalk and color mixing between any two adjacent first and second sub-pixel units, and improving the contrast of full-color display. At the same time, the first photoresist structure can reduce glare interference by reducing the reflectivity of the interface to ambient light, especially in strong light environments, which can improve the visibility of full-color display and further improve the display performance of the Micro LED chip.

[0124] Example 3 ( Figures 12 to 14 )

[0125] Figures 12 to 14 Structural diagrams of micro-light-emitting diode chips in some embodiments of this application are shown. For example... Figures 12 to 14As shown, this embodiment provides a Micro LED chip, which may include: a substrate 21 and a plurality of pixel units D, the plurality of pixel units D being arranged in an array on one side of the substrate 21, and each pixel unit D including a first sub-pixel unit D1 and a third sub-pixel unit D3.

[0126] Along the oz direction, the first sub-pixel unit D1 and the third sub-pixel unit D3 are arranged sequentially. The first sub-pixel unit D1 is closer to the substrate 21 than the third sub-pixel unit D3. One first sub-pixel unit D1 is in contact with the substrate 21. Each third sub-pixel unit D3 is located on a portion of the surface of each first sub-pixel unit D1 that is away from the substrate 21. The first sub-pixel unit D1 includes at least one G Micro LED chip 22 and at least one B Micro LED chip 23. The third sub-pixel unit D3 includes at least one red quantum dot structure 24 and at least one second photoresist structure 252.

[0127] Along the oz direction, the G Micro LED chip 22 and B Micro LED chip 23 in each first sub-pixel unit D1 are arranged sequentially. The G Micro LED chip 22 is closer to the substrate 21 than the B Micro LED chip 23. One G Micro LED chip 22 is in contact with the substrate 21. Each B Micro LED chip 23 is located on at least a portion of the surface of each G Micro LED chip 22 on the side away from the substrate 21.

[0128] Along the ox direction, the red quantum dot structure 24 in each third sub-pixel unit D3 is in contact with the second photoresist structure 252, which is used to block and reflect light.

[0129] Figure 12 The illustration is based on the example of a first sub-pixel unit D1 comprising a G Micro LED chip 22 and a B Micro LED chip 23, with the G Micro LED chip 22 located between the substrate 21 and the B Micro LED chip 23, and a third sub-pixel unit D3 comprising a red quantum dot structure 24 and a second photoresist structure 252, with the red quantum dot structure 24 located to the right of the second photoresist structure 252.

[0130] As an example, in this embodiment, GaN-based green epitaxial wafers and GaN-based blue epitaxial wafers are first grown on different sapphire substrates. Then, the green and blue epitaxial wafers are sequentially bonded to a CMOS driver backplane. Next, the chip structure is etched out. Finally, a second photoresist structure 252 is formed on a portion of the surface of the B Micro LED chip 23 facing away from the substrate 21, followed by the formation of a red quantum dot structure 24. The red quantum dot structure 24 is then patterned using photolithography. Finally, the chip is packaged to obtain the monolithic full-color Micro LED chip in this embodiment.

[0131] As another example, in this embodiment, GaN-based green epitaxial wafers and GaN-based blue epitaxial wafers can be grown in situ on the same sapphire substrate first; then, the chip structure can be etched out; finally, after forming a second photoresist structure 252 on a portion of the surface of the B Micro LED chip 23 away from the substrate 21, a red quantum dot structure 24 can be formed, and the red quantum dot structure 24 can be patterned by photolithography. Finally, after packaging, the monolithic full-color Micro LED chip in this embodiment can be obtained.

[0132] In some embodiments, Figure 13 The diagram shows a structural diagram of a micro-light-emitting diode chip in some embodiments of this application. For example... Figure 13 As shown, Figure 13 and Figure 12 The difference is that in the third sub-pixel unit D3, the red quantum dot structure 24 is located to the left of the second photoresist structure 252.

[0133] In some embodiments, Figure 14 The diagram shows a structural diagram of a micro-light-emitting diode chip in some embodiments of this application. For example... Figure 13 As shown, Figure 13 and Figure 12 The difference is that the third sub-pixel unit D3 includes a red quantum dot structure 24 and two second photoresist structures 252, with the red quantum dot structure 24 located between the two second photoresist structures 252.

[0134] This application provides a micro-light-emitting diode chip. A pixel unit is formed by vertically stacking G Micro LED chips, B Micro LED chips, a horizontally arranged red quantum dot structure, and a second photoresist structure on one side of a substrate. These two different colored Micro LED chips, combined with the red quantum dot structure, can provide full-color display, offering a rich array of colors suitable for a wide range of applications. Simultaneously, by providing a second photoresist structure on at least one side of the red quantum dot structure, the second photoresist structure serves to shield light and prevent light leakage, reducing crosstalk and color mixing between the light emitted from the G Micro LED and B Micro LED chips and the light emitted from the red quantum dot structure, thus improving the contrast of the full-color display. Furthermore, by reducing the reflectivity of the interface to ambient light, glare interference is reduced, especially in strong light environments, improving the visibility of the full-color display and further enhancing display performance. Moreover, the G Micro LED and B Micro LED chips can be fabricated using existing mature green and blue chip processes, and red light emission is achieved by exciting red quantum dots through the G Micro LED chips, eliminating the need for additional red Micro LED chip fabrication. LED chips have low process complexity, low cost, high efficiency and yield, and are mass-producible. They have enabled wafer-level vertical stacking of single-chip full-color displays, which is beneficial for industrial production and application.

[0135] Example 4 ( Figures 15 to 18 )

[0136] Figures 15 to 18 Structural diagrams of micro-light-emitting diode chips in some embodiments of this application are shown. For example... Figures 15 to 18 As shown, this embodiment provides a Micro LED chip, which may include: a substrate 21 and a plurality of pixel units D, the plurality of pixel units D being arranged in an array on one side of the substrate 21, and each pixel unit D including a fourth sub-pixel unit D4 and a fifth sub-pixel unit D5.

[0137] Along the oz direction, the fourth sub-pixel unit D4 and the fifth sub-pixel unit D5 are arranged sequentially. The fourth sub-pixel unit D4 is closer to the substrate 21 than the fifth sub-pixel unit D5. One fourth sub-pixel unit D4 is in contact with the substrate 21. Each fifth sub-pixel unit D5 is located on at least a portion of the surface of each fourth sub-pixel unit D4 on the side away from the substrate 21. The fourth sub-pixel unit D4 includes at least one G Micro LED chip 22. The fifth sub-pixel unit D5 includes at least one B Micro LED chip 23, at least one red quantum dot structure 24, and at least one second photoresist structure 252.

[0138] Along the ox direction, the B Micro LED chip 23, the red quantum dot structure 24, and the second photoresist structure 252 in each fifth sub-pixel unit D5 are in contact. The second photoresist structure 252 is used to block and reflect light.

[0139] Figure 15 The illustration is based on the example of the fourth sub-pixel unit D1 including a G Micro LED chip 22, and the fifth sub-pixel unit D5 including a B Micro LED chip 23, a red quantum dot structure 24 and a second photoresist structure 252, with the second photoresist structure 252 located between the B Micro LED chip 23 and the red quantum dot structure 24.

[0140] As an example, in this embodiment, GaN-based green epitaxial wafers and GaN-based blue epitaxial wafers are first grown on different sapphire substrates. Then, the green and blue epitaxial wafers are sequentially bonded to a CMOS driver backplane. Next, the green and blue epitaxial wafers are etched to different sizes to make the size of the G Micro LED chip 22 larger than the size of the B Micro LED chip 23, thus etching out the chip structure. Finally, a second photoresist structure 252 is formed on the right side of the B Micro LED chip 23 on the G Micro LED chip 22, followed by the formation of a red quantum dot structure 24. The red quantum dot structure 24 is then patterned using photolithography. Finally, packaging is completed to obtain the monolithic full-color Micro LED chip in this embodiment.

[0141] As another example, in this embodiment, GaN-based green epitaxial wafers and GaN-based blue epitaxial wafers are first grown in situ on the same sapphire substrate. Then, different sized etching processes are performed on the green and blue epitaxial wafers respectively, so that the size of the G Micro LED chip 22 is larger than the size of the B Micro LED chip 23, thus etching out the chip structure. Finally, after forming a second photoresist structure 252 on the right side of the B Micro LED chip 23 on the G Micro LED chip 22, a red quantum dot structure 24 is formed, and the red quantum dot structure 24 is patterned by photolithography. Finally, after packaging, the monolithic full-color Micro LED chip in this embodiment can be obtained.

[0142] In some embodiments, Figure 16 The diagram shows a structural diagram of a micro-light-emitting diode chip in some embodiments of this application. For example... Figure 16 As shown, Figure 16 and Figure 15The difference is that in the fifth sub-pixel unit D5, the red quantum dot structure 24 is located to the left of the second photoresist structure 252, and the B Micro LED chip 23 is located to the right of the second photoresist structure 252.

[0143] In some embodiments, Figure 17 The diagram shows structural diagrams of micro-light-emitting diode chips in some embodiments of this application. For example... Figure 17 As shown, Figure 17 and Figure 15 The difference is that in the fifth sub-pixel unit D5, there are two second photoresist structures 252, and there is also a second photoresist structure 252 on the right side of the red quantum dot structure 24.

[0144] In some embodiments, Figure 18 The diagram shows structural diagrams of micro-light-emitting diode chips in some embodiments of this application. For example... Figure 18 As shown, Figure 18 and Figure 16 The difference is that in the fifth sub-pixel unit D5, there are two second photoresist structures 252, and there is also a second photoresist structure 252 on the left side of the red quantum dot structure 24.

[0145] It should be noted that, Figure 17 and Figure 18 The second photoresist structure 252 at both ends is adopted, and the red quantum dot structure 24 can be realized by inkjet printing red quantum dots.

[0146] This application provides a micro-light-emitting diode chip. A pixel unit is formed by vertically stacking G Micro LED chips from bottom to top on one side of a substrate, horizontally arranging B Micro LED chips, a red quantum dot structure, and a second photoresist structure. These two different colored Micro LED chips, combined with the red quantum dot structure, can provide full-color display, offering a rich array of colors suitable for a wide range of applications. Simultaneously, by providing a second photoresist structure on at least one side of the red quantum dot structure, the second photoresist structure serves to shield light and prevent light leakage, reducing crosstalk and color mixing between the light emitted from the G Micro LED and B Micro LED chips and the light emitted from the red quantum dot structure, thus improving the contrast of the full-color display. Furthermore, by reducing the reflectivity of the interface to ambient light, glare interference is reduced, especially in strong light environments, improving the visibility of the full-color display and further enhancing display performance. Moreover, the G Micro LED and B Micro LED chips can be fabricated using existing mature green and blue chip processes, and red light emission is achieved by exciting red quantum dots through the G Micro LED chips, eliminating the need for additional red Micro LED chip fabrication. LED chips have low process complexity, low cost, high efficiency and yield, and can effectively realize wafer-level vertical stacking of single-chip full-color displays. They have good mass production feasibility and great prospects for future product expansion.

[0147] It should be understood that in the various embodiments of this application, the order of the above-mentioned processes does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0148] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0149] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0150] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for example, the division of units is merely a logical functional division, and there may be other division methods in actual implementation; for example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interface, and the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0151] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0152] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0153] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A micro light-emitting diode chip, characterized in that, include: substrate; Multiple pixel units are arranged in an array on one side of the substrate; Each pixel unit includes at least one green micro-light-emitting diode chip and at least one blue micro-light-emitting diode chip; Along a first direction, the green micro-light-emitting diode chip and the blue micro-light-emitting diode chip are arranged sequentially, with the green micro-light-emitting diode chip being closer to the substrate than the blue micro-light-emitting diode chip, and the blue micro-light-emitting diode chip being located on at least a portion of the surface of the green micro-light-emitting diode chip on the side facing away from the substrate; The first direction is perpendicular to the substrate.

2. The micro light-emitting diode chip according to claim 1, characterized in that, Each pixel unit includes a first sub-pixel unit and a second sub-pixel unit, wherein the first sub-pixel unit and the second sub-pixel unit are spaced apart. The first sub-pixel unit includes at least one green micro-light-emitting diode chip and at least one blue micro-light-emitting diode chip, and the second sub-pixel unit includes at least one color micro-light-emitting diode chip and at least one red quantum dot structure, wherein the color micro-light-emitting diode chip includes any one of the following: only the green micro-light-emitting diode chip, only the blue micro-light-emitting diode chip, or a combination of the green micro-light-emitting diode chip and the blue micro-light-emitting diode chip; Along the first direction, in each of the first sub-pixel units, the green micro-light-emitting diode chip and the blue micro-light-emitting diode chip are arranged sequentially, and the green micro-light-emitting diode chip is closer to the substrate than the blue micro-light-emitting diode chip, and the blue micro-light-emitting diode chip is located on at least a portion of the surface of the green micro-light-emitting diode chip on the side away from the substrate; Along the first direction, in each second sub-pixel unit, the color micro-light-emitting diode chip and the red quantum dot structure are arranged sequentially, and the color micro-light-emitting diode chip is closer to the substrate than the red quantum dot structure, and the red quantum dot structure is located on at least a portion of the surface of the color micro-light-emitting diode chip on the side away from the substrate.

3. The micro light-emitting diode chip according to claim 2, characterized in that, A first photoresist structure is provided between any two adjacent first sub-pixel units and second sub-pixel units. The first photoresist structure is in contact with the first sub-pixel unit and the second sub-pixel unit respectively. The first photoresist structure is used to block and reflect light.

4. The micro light-emitting diode chip according to claim 1, characterized in that, Each pixel unit includes a first sub-pixel unit and a third sub-pixel unit; Along the first direction, the first sub-pixel unit and the third sub-pixel unit are arranged sequentially, and the first sub-pixel unit is closer to the substrate than the third sub-pixel unit. The third sub-pixel unit is located on a portion of the surface of the first sub-pixel unit facing away from the substrate. The first sub-pixel unit includes at least one green micro-light-emitting diode chip and at least one blue micro-light-emitting diode chip. The third sub-pixel unit includes at least one second photoresist structure and at least one red quantum dot structure. Along the first direction, in each of the first sub-pixel units, the green micro-light-emitting diode chip and the blue micro-light-emitting diode chip are arranged sequentially, and the green micro-light-emitting diode chip is closer to the substrate than the blue micro-light-emitting diode chip, and the blue micro-light-emitting diode chip is located on at least a portion of the surface of the green micro-light-emitting diode chip on the side away from the substrate; Along the second direction, in each of the third sub-pixel units, the red quantum dot structure is in contact with the second photoresist structure, which is used to block and reflect light; The second direction is a direction parallel to the substrate.

5. The micro light-emitting diode chip according to claim 4, characterized in that, The number of the second photoresist structure is one, and along the second direction, the second photoresist structure is located to the left or right of the red quantum dot structure; Alternatively, there may be two second photoresist structures, with the red quantum dot structure located between the two second photoresist structures along the second direction.

6. The micro light-emitting diode chip according to claim 1, characterized in that, Each pixel unit includes a fourth sub-pixel unit and a fifth sub-pixel unit. Along the first direction, the fourth sub-pixel unit and the fifth sub-pixel unit are arranged sequentially, and the fourth sub-pixel unit is closer to the substrate than the fifth sub-pixel unit. Each fifth sub-pixel unit is located on at least a portion of the surface of each fourth sub-pixel unit on the side away from the substrate. The fourth sub-pixel unit includes at least one green micro-light-emitting diode chip, and the fifth sub-pixel unit includes at least one blue micro-light-emitting diode chip, at least one red quantum dot structure, and at least one second photoresist structure. Along the second direction, one of the second photoresist structures in each of the fifth sub-pixel units is located between the blue micro-light-emitting diode chip and the red quantum dot structure, and the blue micro-light-emitting diode chip, the second photoresist structure and the red quantum dot structure are in contact. The second photoresist structure is used to block and reflect light. The second direction is a direction parallel to the substrate.

7. The micro light-emitting diode chip according to claim 6, characterized in that, Along the second direction, each of the fifth sub-pixel units includes a blue micro-light-emitting diode chip, a second photoresist structure, and a red quantum dot structure, with the second photoresist structure located between the blue micro-light-emitting diode chip and the red quantum dot structure; Alternatively, each of the fifth sub-pixel units includes one of the blue micro-light-emitting diode chips, two of the second photoresist structures, and one of the red quantum dot structures, with one of the second photoresist structures located between the blue micro-light-emitting diode chip and the red quantum dot structure, and the other of the second photoresist structures located on the side of the red quantum dot structure away from the blue micro-light-emitting diode chip.

8. The micro light-emitting diode chip according to claim 1, characterized in that, A first photoresist structure is disposed between any two adjacent pixel units. The first photoresist structure is in contact with the pixel unit and is used to block and reflect light.

9. The micro light-emitting diode chip according to any one of claims 1 to 8, characterized in that, The size of each of the green micro-light-emitting diode chips and each of the blue micro-light-emitting diode chips is less than 200 μm.

10. A display device, characterized in that, Includes the micro light-emitting diode chip as described in any one of claims 1 to 9.

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