Mini-LED / Micro-LED Full-Color Display Device Based on Photonic Crystal and Its Fabrication Method

Abstract

The present application relates to a kind of based on photonic crystal Mini-LED / Micro-LED full-color display device and preparation method thereof, Mini-LED / Micro-LED full-color display device includes: driving substrate, is provided with driving circuit;At least three colors of light emitting unit, bonding in driving substrate, each light emitting unit is blue light Mini-LED / Micro-LED chip processing preparation, each light emitting unit includes the buffer layer, n-GaN layer, blue light multiple quantum well layer and p-GaN layer sequentially stacked;Each described light emitting unit further includes control electrode, the control electrode includes p-type electrode layer and n-type electrode layer;Each light emitting unit can also be provided with the green photonic crystal structure or red light body structure extending to n-GaN layer through buffer layer, and green light emitting unit or red light emitting unit is formed, the light emitting unit without photonic crystal structure is blue light emitting unit;In array arrangement adjacent three light emitting units include red light emitting unit, green light emitting unit and blue light emitting unit.

Description

Technical Field

[0001] This invention relates to the field of semiconductor nanodisplay technology, and in particular to a Mini-LED / Micro-LED full-color display device based on photonic crystals and its fabrication method. Background Technology

[0002] With the rise of emerging technologies such as smart wearable devices, augmented reality, and virtual reality, high-end display technology has become an urgent market demand. Mini-LEDs and Micro-LEDs are next-generation display technologies with self-emissive display characteristics. Compared to Organic Light-Emitting Diode (OLED) technology, Mini-LED and Micro-LED display devices offer a range of advantages, including higher brightness and stability, higher luminous efficiency, lower power consumption, and faster response time. A series of products have already been developed for use in televisions, flat panel displays, and mobile phone displays.

[0003] The display principle of the display device is to thin, miniaturize, and array the LED structure, with its size only on the order of 1-100 micrometers, and then form a display array through array transfer.

[0004] However, display technology still faces many key technical challenges, including the integration of massive numbers of devices. Furthermore, the reduction in the size of Mini-LED / Micro-LEDs also leads to problems such as performance degradation and increased manufacturing difficulty. For example, the traditional manufacturing process for full-color Mini-LED / Micro-LEDs requires the separate fabrication of red, green, and blue monochrome Micro-LED pixels before transfer. This not only increases manufacturing costs in the screening, testing, and packaging processes of Mini-LED / Micro-LED full-color display devices, but also results in low luminous efficiency and low product yield for the red and green monochrome Mini-LEDs, ultimately leading to low luminous efficiency and yield of the entire Mini-LED / Micro-LED full-color display device. Summary of the Invention

[0005] The present invention provides a Mini-LED / Micro-LED full-color display device based on photonic crystal and its fabrication method to solve the technical problems of high process cost, low luminous efficiency and low product yield in the manufacturing process of full-color LED display arrays.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] This invention provides a Mini-LED / Micro-LED full-color display device based on photonic crystals, comprising:

[0008] A driving substrate is provided with a driving circuit.

[0009] At least three light-emitting units of different colors are bonded to the driving substrate. Each light-emitting unit is fabricated from a blue Mini-LED / Micro-LED chip. Each light-emitting unit includes a buffer layer, an n-GaN layer, a blue multi-quantum well layer, and a p-GaN layer stacked sequentially. Each light-emitting unit also includes a control electrode, which includes a p-type electrode layer and an n-type electrode layer.

[0010] The p-type electrode layer is electrically connected to the p-GaN layer and the driving circuit;

[0011] The n-type electrode layer is electrically connected to the n-GaN layer and the driving circuit;

[0012] In the array of three adjacent light-emitting units of different colors, two of the light-emitting units are further provided with a photonic crystal structure that penetrates the buffer layer and extends to the n-GaN layer. The photonic crystal structure includes a plurality of crystal holes and quantum dots filling the crystal holes. The quantum dots in one of the light-emitting units are red quantum dots, and the quantum dots in the other light-emitting unit are green quantum dots.

[0013] In one embodiment, an isolation structure is provided between two adjacent light-emitting units to prevent light crosstalk between the two light-emitting units.

[0014] In one embodiment, the isolation structure includes a metal light-shielding layer and an oxide isolation layer that encloses the metal light-shielding layer, the oxide isolation layer connecting the sides of two adjacent light-emitting units.

[0015] In one embodiment, the p-type electrode layer is electrically connected to the driving circuit and the p-GaN layer along the periphery of the light-emitting unit, and the p-type electrode layer is covered by the oxide isolation layer on the periphery of the light-emitting unit; and / or, the n-type electrode layer is electrically connected to the driving circuit and the n-GaN layer along the periphery of the light-emitting unit, and the n-type electrode layer is covered by the oxide isolation layer on the periphery of the light-emitting unit.

[0016] In one embodiment, the periphery of the light-emitting unit is further covered with a SiO2 layer, one end of which extends to the n-GaN layer and the other end of which extends to the side of the p-GaN layer facing the driving substrate; the p-type electrode layer covers the SiO2 layer and one end extends to contact the p-GaN layer; the n-type electrode layer covers the SiO2 layer and one end extends to contact the n-GaN layer.

[0017] In one embodiment, the crystal hole extends through the n-GaN layer to the light-emitting surface of the blue light-emitting multiple quantum well layer.

[0018] In one embodiment, in the photonic crystal-based Mini-LED / Micro-LED full-color display device, any three adjacent light-emitting units can emit red, green, and blue light.

[0019] Secondly, the present invention provides a method for fabricating a Mini-LED / Micro-LED full-color display device based on photonic crystals, the method comprising the following steps:

[0020] A Mini-LED / Micro-LED chip array is provided, comprising multiple blue Mini-LED / Micro-LED chips. Each of the blue Mini-LED / Micro-LED chips includes a buffer layer, an n-GaN layer, a blue multi-quantum well layer, a p-GaN layer, and a control electrode stacked sequentially from bottom to top on a sapphire substrate. The control electrode includes a p-type electrode layer and an n-type electrode layer.

[0021] A processing substrate is provided. The blue Mini-LED / Micro-LED chip array is thinned by mechanical polishing to expose the buffer layer. Then, the blue Mini-LED / Micro-LED chip array is transferred onto the processing substrate.

[0022] Crystal holes are fabricated by using electron beam lithography, helium ion microscopy-focused ion beam system, inductively coupled plasma etching, or nanoimprinting to form a plurality of crystal holes on the blue Mini-LED / Micro-LED chip that penetrate the buffer layer and extend to the n-GaN layer.

[0023] Quantum dots are filled into the crystal holes of different blue Mini-LED / Micro-LED chips by electrodeposition or inkjet printing, either green or red quantum dots, to ensure that in three adjacent blue Mini-LED / Micro-LED chips arranged in an array, one chip contains red quantum dots and the other contains green quantum dots.

[0024] A driving substrate with a driving circuit is provided. The blue Mini-LED / Micro-LED chip array with the crystal hole and the quantum dot is transferred to the driving substrate by bonding and the processing substrate is peeled off. The p-type electrode layer is electrically connected to the p-GaN layer and the driving circuit, and the n-type electrode layer is electrically connected to the n-GaN layer and the driving circuit.

[0025] In one embodiment, in the step of providing the Mini-LED / Micro-LED chip array, for any two adjacent Mini-LED / Micro-LED chips, an isolation structure is provided, which is used to prevent light crosstalk between the light emitted by two adjacent light-emitting units.

[0026] In one embodiment, the isolation structure includes a metal light-shielding layer and an oxide isolation layer that encloses the metal light-shielding layer, the oxide isolation layer connecting the sides of two adjacent light-emitting units.

[0027] As can be seen from the above technical solutions, the embodiments of the present invention have at least the following advantages and positive effects:

[0028] This invention discloses a Mini-LED / Micro-LED full-color display device based on photonic crystals and its fabrication method. The Mini-LED / Micro-LED full-color display device includes a driving substrate and an RGB LED unit formed by at least three light-emitting units. Two of the light-emitting units have a color conversion layer (i.e., a photonic crystal structure) located within a buffer layer and an n-GaN layer, while the remaining light-emitting unit does not have a photonic crystal structure. Based on this, within the same RGB LED unit, the red photonic crystal in the red light-emitting unit can convert blue light emitted from the blue multi-quantum well layer into red light; the green photonic crystal in the green light-emitting unit can convert blue light emitted from the blue multi-quantum well layer into green light; and the blue multi-quantum well layer in the blue light-emitting unit can emit blue light. This solution controls the emission of the three RGB colors within the same RGB LED unit, eliminating the need for selecting RGB LEDs and reducing screening costs. Moreover, the three different colored light-emitting units of this invention are all fabricated using the most efficient and stable blue Mini-LED / Micro-LED chips available on the market. This greatly reduces the huge costs required for chip testing and mass transfer due to the low yield of red and green Micro-LEDs, thereby further reducing manufacturing costs. Secondly, the quantum dot material in the color conversion layer (photonic crystal structure) has excellent optical properties such as high color conversion efficiency (>90%), high stability, and narrow emission spectrum. This allows the RGB LED units to achieve a wider color gamut and longer display lifespan, and improves the luminous efficiency and product yield of Mini-LED / Micro-LED full-color display devices. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the structure of a Mini-LED / Micro-LED full-color display device according to an embodiment of the present invention;

[0031] Figure 2 for Figure 1 A schematic diagram of the light-emitting diffusion structure of the red light-emitting unit in the full-color display device shown.

[0032] Figure 3 for Figure 1 A schematic diagram of the light-emitting diffusion structure of the green light-emitting unit in the full-color display device shown.

[0033] Figure 4 for Figure 1 A schematic diagram of the light-emitting diffusion structure of the blue light-emitting unit in the full-color display device shown;

[0034] Figure 5 for Figure 1 The diagram shows the array arrangement of three adjacent light-emitting units that emit red, blue, and green light in an embodiment of the full-color device.

[0035] Figure 6 for Figure 1 The diagram shown is a structural schematic of a single light-emitting unit in a full-color display device.

[0036] Figures 7 to 10 This diagram illustrates the steps involved in fabricating a Mini-LED / Micro-LED full-color display device according to an embodiment of the present invention.

[0037] The annotations in the attached figures are explained as follows:

[0038] 10. Mini-LED / Micro-LED full-color display device; 100. Driving substrate; 200. Light-emitting unit; 200a. Red light-emitting unit; 200b. Green light-emitting unit; 200c. Blue light-emitting unit; 210. Buffer layer; 220. n-GaN layer; 230. Blue light multi-quantum well layer; 240. GaN capping layer; 250. p-GaN layer; 260. Control electrode layer; 261. p-type electrode layer; 262. n-type electrode layer; 270. SiO2 layer; 280. Photonic crystal structure; 281. Crystal hole; 282. Quantum dot; 282a. Red quantum dot; 282b. Green quantum dot; 300. Isolation structure; 310. Oxide isolation layer; 320. Metal shielding layer; 201. Blue light Mini-LED / Micro-LED chip; 202. Blue light Mini-LED / Micro-LED chip array; 20, sapphire substrate; 30, processed substrate. Detailed Implementation

[0039] Typical embodiments embodying the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various variations in different embodiments without departing from the scope of the present invention, and the descriptions and illustrations herein are for illustrative purposes only and not intended to limit the present invention.

[0040] Furthermore, the terms "first" and "second" 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. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0041] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "setup," and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0042] refer to Figure 1 This invention provides a Mini-LED / Micro-LED full-color display device 10 based on photonic crystals. The Mini-LED / Micro-LED full-color display device 10 includes a driving substrate 100 and at least three light-emitting units 200. The light-emitting units 200 are fabricated using blue Mini-LED / Micro-LED chips 201. The three light-emitting units 200 are arranged in an array and bonded to the driving substrate 100. Furthermore, the three light-emitting units 200 form an RGB unit, and the three light-emitting units in the same RGB unit can emit red, green, and blue light respectively, thereby achieving different color emission control within the same RGB unit, completing RGB full-color display, and improving the resolution of the Micro-LED full-color display device 10.

[0043] Please refer to Figures 2-4 The driving substrate 100 is provided with a driving circuit, and the RGB unit includes a red light-emitting unit 200a, a green light-emitting unit 200b and a blue light-emitting unit 200c. Figure 2 This illustrates that when the driving circuit controls the red light-emitting unit 200a to work independently, the RGB unit emits red light; Figure 3 This illustrates how the RGB unit emits green light when the driving circuit controls the green light-emitting unit independently. Figure 4 This illustrates how the RGB unit emits blue light when the driving circuit controls the blue light-emitting unit independently. Preferably, see reference... Figure 5To ensure more uniform light emission from the Micro-LED full-color display device 10, any three adjacent light-emitting units 200 can emit red (R), green (G), and blue (B) light. Therefore, within the same Micro-LED full-color display device 10, any three adjacent light-emitting units 200 can constitute an RGB unit. The Micro-LED full-color display device 10 is composed of multiple uniformly arrayed RGB units. It should be understood that in other embodiments, the number of light-emitting units 200 in the same Micro-LED full-color display device is not limited, nor is the number of light-emitting units 200 for each color, nor is the arrangement of light-emitting units 200 of different colors limited. It is only necessary to satisfy the requirement that at least three light-emitting units 200 of different colors constitute an RGB unit for three-color emission within the same Micro-LED full-color display device 10.

[0044] refer to Figure 6 Each light-emitting unit 200 includes a buffer layer 210, an n-GaN layer 220, a blue light multi-quantum well layer 230, a GaN capping layer 240 and a p-GaN layer 250 stacked sequentially. The light-emitting unit 200 also includes a control electrode layer 260 and a SiO2 layer 270. The control electrode layer 260 includes a p-type electrode layer 261 and an n-type electrode layer 262. In one embodiment, the p-type electrode layer 261 is electrically connected to the driving circuit and the p-GaN layer 250 along the periphery of the light-emitting unit 200; the n-type electrode layer 262 is electrically connected to the driving circuit and the n-GaN layer 220 along the periphery of the light-emitting unit 200; the SiO2 layer 270, as a commonly used blocking and isolating layer, mainly functions to prevent impurity diffusion, provide dielectric isolation, and insulation. In this application, the SiO2 layer 270 is used, on the one hand, to block the electrical connection between the layer structure other than the control electrode layer 260 (i.e., the four electrode layers: n-GaN layer 220, blue light multi-quantum well layer 230, GaN capping layer 240, and p-GaN layer 250) and the driving circuit; on the other hand, the SiO2 layer 270 is used to block impurity diffusion between the control electrode layer 260 and other layer electrodes, thereby protecting the control electrode layer 260 and other electrode layer structures. Specifically, Figure 6The illustration shows that the SiO2 layer 270 is disposed along the periphery of the light-emitting unit 200 between the p-type electrode layer 261 and the light-emitting unit 200, and between the n-type electrode layer 262 and the light-emitting unit 200. It should be understood that in other embodiments, the GaN capping layer 240 may not be necessary. Furthermore, the positions of the p-type electrode layer 261 and the n-type electrode layer 262 are not limited; they can extend along the periphery of the light-emitting unit 200, be stacked on opposite sides of the light-emitting unit 200, or be disposed at other positions within the light-emitting unit, as long as the p-type electrode layer 261 is electrically connected to the p-GaN layer and the driving circuit, and the n-type electrode layer is electrically connected to the n-GaN layer and the driving circuit. Additionally, the position of the SiO2 layer 270 can be adapted to different positions of the p-type electrode layer 261 and the n-type electrode layer 262, and may even be omitted altogether.

[0045] Reference Figure 1 and Figure 6In the same RGB unit (three adjacent light-emitting units 200 arranged in an array), two of the light-emitting units 200 are further provided with photonic crystal structures 280 that penetrate the buffer layer 210 and extend to the n-GaN layer. The photonic crystal structure 280 acts as a color conversion layer, which can convert the blue light emitted by the blue light multi-quantum well layer 230 in the light-emitting unit 200 into other colors. The photonic crystal structure 280 includes multiple crystal holes 281 and quantum dots 282 filled in the crystal holes 281. The crystal holes 281 filled with red quantum dots 282a form red photonic crystals 280a, and the light-emitting unit 200 with red photonic crystals 280a is the aforementioned red light-emitting unit 200a; the crystal holes 281 filled with green quantum dots 282b form green photonic crystals 280b, and the light-emitting unit 200 with green photonic crystals 280b is the aforementioned green light-emitting unit 200b; the light-emitting unit 200 without crystal structure 280 is the aforementioned blue light-emitting unit 200c. Red photonic crystal 280a and green photonic crystal 280b, acting as color conversion layers, can convert blue light emitted from the blue multi-quantum well layer 230 into green and red light, respectively. Specifically, red quantum dot 282a and green quantum dot 282b materials can further absorb blue light emitted from the blue multi-quantum well layer 230 and confined within the photonic crystal structure 280, thereby converting the absorbed blue light into red and green light, which is then emitted from the surface of the photonic crystal structure 280, realizing a full-color Micro-LED light source. Furthermore, the depth and size of the crystal aperture 281 can be calculated and designed using simulation software such as FDTD, MPB, and RSoft. The size of the crystal aperture 281 is 100nm~5µm, sufficient for quantum dot 282 material (<10 nm) to fill the interior of the crystal aperture 281. In this application, the materials of the red quantum dot 282a and the green quantum dot 282b are group II-VI compound semiconductor materials or group III-V compound semiconductor materials, wherein the group II-VI compound semiconductor materials include CdS, CdSe, CdS / ZnS, CdSe / ZnS or CdSe / CdS / ZnS, and the group III-V compound semiconductor materials include InP, InP / ZnSe or InP / ZnSe / ZnS.

[0046] The present invention discloses a Mini-LED / Micro-LED full-color display device 10 based on photonic crystals and its fabrication method. The Mini-LED / Micro-LED full-color display device includes a driving substrate 100 and an RGB LED unit formed by at least three light-emitting units 200. Two of the light-emitting units 200 are provided with a color conversion layer (i.e., a photonic crystal structure 280) located within a buffer layer 210 and an n-GaN layer 220, while the remaining light-emitting unit 200 does not have a photonic crystal structure 280. Based on this, within the same RGB LED unit, the red photonic crystal 280a in the red light-emitting unit 200a can convert blue light emitted from the blue multi-quantum well layer 230 into red light; the green photonic crystal 280b in the green light-emitting unit 200b can convert blue light emitted from the blue multi-quantum well layer 230 into green light; and the blue multi-quantum well layer 230 in the blue light-emitting unit 200c can emit blue light. This solution controls the emission of the three RGB colors within a single RGB LED unit, eliminating the need for separate selection of RGB LEDs and reducing screening costs during manufacturing. Furthermore, the three different color emission units 200 of this invention are all fabricated using the most efficient and stable blue Mini-LED / Micro-LED chip 201 available on the market. This significantly reduces the substantial costs associated with chip testing and mass transfer due to the low yield of red and green Mini-LED / Micro-LEDs, thus greatly lowering manufacturing costs. Secondly, the quantum dot 282 material in the color conversion layer (photonic crystal structure 280) possesses excellent optical properties such as high color conversion efficiency (>90%), high stability, and a narrow emission spectrum. This allows the RGB LED unit to achieve a wider color gamut and longer lifespan, improving the luminous efficiency and yield of the Mini-LED / Micro-LED full-color display device 100.

[0047] In this embodiment, both the red photonic crystal 280a and the green photonic crystal 280b penetrate the light-emitting surface of the n-GaN layer 220 to the blue light multi-quantum well layer 230. This arrangement increases the frequency of blue light conversion in a single light-emitting unit 200 to ensure precise control of the emitted color.

[0048] In one embodiment, the Mini-LED / Micro-LED full-color display device 10 further includes an isolation structure 300 disposed between two adjacent light-emitting units 200. Figures 2-4 The diagram illustrates how the isolation structure 300 prevents crosstalk between light emitted from two adjacent light-emitting units 200. Specifically, Figure 1The diagram illustrates that the isolation structure 300 includes an oxide isolation layer 310 and a metal light-shielding layer 320. The oxide isolation layer 310 covers the periphery of each light-emitting unit 200 (covering the control electrode layer 260) and the periphery of the metal light-shielding layer 320, respectively. The oxide isolation layer 310 indirectly connects the sides of two adjacent light-emitting units 200 through the metal light-shielding layer 320. The isolation structure 300 extends a self-emissive surface along the periphery of the self-driven substrate 100 (penetrating the entire light-emitting unit 200 along its thickness direction). It should be understood that the oxide isolation layer 310 and the metal light-shielding layer 320 are merely one method of isolation to prevent optical crosstalk between two adjacent light-emitting units 200. In other embodiments, the isolation structure 300 may employ other light-absorbing isolation materials.

[0049] The present invention also provides a method for fabricating a Mini-LED / Micro-LED full-color display device 10 based on photonic crystals. The method for fabricating the Mini-LED / Micro-LED full-color display device 10 of the present invention includes the following steps:

[0050] Step S10, refer to Figure 7 The present invention provides a Mini-LED / Micro-LED chip array 202 comprising multiple (at least three) blue Mini-LED / Micro-LED chips 201, each blue Mini-LED / Micro-LED chip 201 comprising a buffer layer 210, an n-GaN layer 220, a blue multi-quantum well layer 230, a GaN capping layer 240 and a p-GaN layer 250, and a control electrode 260 stacked on a blue sapphire substrate 20; the control electrode 260 comprising a p-type electrode layer 261 and an n-type electrode layer 262.

[0051] Step S20, in conjunction with the reference Figure 8 and Figure 9 A processing substrate 30 is provided. The blue Mini-LED / Micro-LED chip array 202 is thinned by mechanical polishing of the sapphire substrate 20 layer to expose the buffer layer 210. Then, the blue Mini-LED / Micro-LED chip array 202 is flip-chip transferred onto the processing substrate 30. Figure 8 This illustrates that the control electrode layer 260 is in contact with the upper surface of the processing substrate 30, and the buffer layer 210 is exposed as the light-emitting surface.

[0052] Step S30, refer to Figure 9Crystal holes 281 are fabricated by photolithography, electron beam lithography, helium ion microscopy-focused ion beam system, inductively coupled plasma etching or nanoimprinting to form multiple crystal holes 281 on the blue Mini-LED / Micro-LED chip 201 that penetrate the buffer layer 210 and extend to the n-GaN layer 220.

[0053] Step S40, refer to Figure 10 A driving substrate 100 with a driving circuit is provided. The blue Mini-LED / Micro-LED chip array 202 with crystal holes 281 is peeled off from the processing substrate 40 and transferred to the driving substrate 100 by bonding. The p-type electrode layer 261 is electrically connected to the p-GaN layer 250 and the driving circuit, and the n-type electrode layer 262 is electrically connected to the n-GaN layer 220 and the driving circuit. Moreover, the p-type electrode layer 261 and the n-type electrode layer 262 of the control electrode layer 260 directly contact the driving circuit to form a closed loop, so that a single light-emitting unit 200 can be controlled individually without the need for additional circuit connection design.

[0054] Step S50, refer to Figure 1 Quantum dots 282 are filled by electrodeposition or inkjet printing into the crystal holes 281 of different blue Mini-LED / Micro-LED chips 201, using either red quantum dots 282a or green quantum dots 282b. This ensures that in three adjacent blue Mini-LED / Micro-LED chips 201 arranged in an array, one chip contains red quantum dots 282a, and another contains green quantum dots 282b. Figure 1 The Mini-LED / Micro-LED full-color display device 10 shown is as follows: a blue Mini-LED / Micro-LED chip 201 with a red photonic crystal 280a forms a red light-emitting unit 200a; a blue Mini-LED / Micro-LED chip 201 with a green photonic crystal 280b forms a green light-emitting unit 200b; and a blue Mini-LED / Micro-LED chip 201 without a crystal structure 280b is a blue light-emitting unit 200c.

[0055] It should be explained that the processing order of steps S40 and S50 can be interchanged. That is, the quantum dots 282 can be filled first, and then the blue Mini-LED / Micro-LED chip array 202 with crystal structure 280 can be peeled off from the processing substrate 40 and transferred to the driving substrate 100. Additionally, in the Mini-LED / Micro-LED chip array provided in step S10, an isolation structure 300 is provided between any two adjacent Mini-LED / Micro-LED chips. The isolation structure 300 is used to prevent light crosstalk between adjacent light-emitting units 200. Specifically, the isolation structure 300 includes a metal light-shielding layer 320 and an oxide isolation layer 310 that wraps around the metal light-shielding layer 320. The oxide isolation layer 310 indirectly connects the sides of adjacent light-emitting units 200 through the metal light-shielding layer 320. It should be understood that in other embodiments, the isolation structure 300 can use other light-absorbing isolation materials.

[0056] Although the invention has been described with reference to several typical embodiments, it should be understood that the terminology used is illustrative and exemplary, and not restrictive. Since the invention can be embodied in many forms without departing from the spirit or essence of the invention, it should be understood that the above embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope defined by the appended claims. Therefore, all variations and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A Mini-LED / Micro-LED full-color display device based on photonic crystal, characterized in that, include: A driving substrate is provided with a driving circuit. At least three light-emitting units of different colors are bonded to the driving substrate, and each light-emitting unit is fabricated from a blue Mini-LED / Micro-LED chip; each light-emitting unit includes a buffer layer, an n-GaN layer, a blue multi-quantum well layer and a p-GaN layer stacked sequentially; each light-emitting unit also includes a control electrode, which includes a p-type electrode layer and an n-type electrode layer. The p-type electrode layer is electrically connected to the p-GaN layer and the driving circuit; The n-type electrode layer is electrically connected to the n-GaN layer and the driving circuit; In the array of three adjacent light-emitting units of different colors, two of the light-emitting units are further provided with a photonic crystal structure that penetrates the buffer layer and extends to the n-GaN layer. The photonic crystal structure includes a plurality of crystal holes and quantum dots filling the crystal holes. The quantum dots in one of the light-emitting units are red quantum dots, and the quantum dots in the other light-emitting unit are green quantum dots.

2. The Mini-LED / Micro-LED full-color display device based on photonic crystal according to claim 1, characterized in that, An isolation structure is provided between two adjacent light-emitting units to prevent light crosstalk between the two light-emitting units.

3. The Mini-LED / Micro-LED full-color display device based on photonic crystal according to claim 2, characterized in that, The isolation structure includes a metal light-shielding layer and an oxide isolation layer that wraps the metal light-shielding layer. The oxide isolation layer connects the sides of two adjacent light-emitting units.

4. The Mini-LED / Micro-LED full-color display device based on photonic crystal according to claim 3, characterized in that, The p-type electrode layer is electrically connected to the driving circuit and the p-GaN layer along the periphery of the light-emitting unit, and the p-type electrode layer is covered by the oxide isolation layer on the periphery of the light-emitting unit; and / or, the n-type electrode layer is electrically connected to the driving circuit and the n-GaN layer along the periphery of the light-emitting unit, and the n-type electrode layer is covered by the oxide isolation layer on the periphery of the light-emitting unit.

5. The Mini-LED / Micro-LED full-color display device based on photonic crystal according to claim 1, characterized in that, The periphery of the light-emitting unit is also covered with a SiO2 layer, one end of which extends to the n-GaN layer and the other end of which extends to the side of the p-GaN layer facing the driving substrate; the p-type electrode layer covers the SiO2 layer and one end extends to contact the p-GaN layer; the n-type electrode layer covers the SiO2 layer and one end extends to contact the n-GaN layer.

6. The Mini-LED / Micro-LED full-color display device based on photonic crystal according to claim 1, characterized in that, The crystal hole extends through the n-GaN layer to the light-emitting surface of the blue light multi-quantum well layer.

7. The Mini-LED / Micro-LED full-color display device based on photonic crystal according to claim 1, characterized in that, In the aforementioned Mini-LED / Micro-LED full-color display device based on photonic crystals, any three adjacent light-emitting units can emit red, green, and blue light.

8. A method for fabricating a Mini-LED / Micro-LED full-color display device based on photonic crystals, characterized in that, The fabrication method of the Mini-LED / Micro-LED full-color display device includes the following steps: A Mini-LED / Micro-LED chip array is provided, comprising multiple blue Mini-LED / Micro-LED chips. Each of the blue Mini-LED / Micro-LED chips includes a buffer layer, an n-GaN layer, a blue multi-quantum well layer, a p-GaN layer, and a control electrode stacked sequentially on a sapphire substrate from bottom to top. The control electrode includes a p-type electrode layer and an n-type electrode layer. A processing substrate is provided. The blue Mini-LED / Micro-LED chip array is thinned by mechanical polishing to expose the buffer layer. Then, the blue Mini-LED / Micro-LED chip array is transferred onto the processing substrate. Crystal holes are fabricated by electron beam lithography, helium ion microscopy-focused ion beam system, inductively coupled plasma etching or nanoimprinting to form a plurality of crystal holes that penetrate the buffer layer and extend to the n-GaN layer on the blue Mini-LED / Micro-LED chip. Quantum dots are filled by electrodeposition or inkjet printing into the crystal holes of different blue Mini-LED / Micro-LED chips, either green or red quantum dots, to ensure that in three adjacent blue Mini-LED / Micro-LED chips arranged in an array, one chip contains red quantum dots and the other contains green quantum dots. A driving substrate with a driving circuit is provided. The blue Mini-LED / Micro-LED chip array with the crystal hole and the quantum dot is transferred to the driving substrate by bonding and the processing substrate is peeled off. The p-type electrode layer is electrically connected to the p-GaN layer and the driving circuit, and the n-type electrode layer is electrically connected to the n-GaN layer and the driving circuit.

9. The preparation method according to claim 8, characterized in that, In the provided Mini-LED / Micro-LED chip array step, for any two adjacent Mini-LED / Micro-LED chips, an isolation structure is provided, which is used to prevent light crosstalk between the light emitted by two adjacent light-emitting units.

10. The preparation method according to claim 9, characterized in that, The isolation structure includes a metal light-shielding layer and an oxide isolation layer that wraps the metal light-shielding layer. The oxide isolation layer connects the sides of two adjacent light-emitting units.

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