Mini-LED / Micro-LED full-color display device based on photonic crystal and preparation method of Mini-LED / Micro-LED full-color display device

Abstract

The invention relates to a Mini-LED / Micro-LED full-color display device based on a photonic crystal and a preparation method of the Mini-LED / Micro-LED full-color display device, and the Mini-LED / Micro-LED full-color display device comprises a driving substrate which is provided with a driving circuit; the light-emitting units of at least three colors are bonded to the driving substrate, each light-emitting unit is prepared by processing a blue light Mini-LED / Micro-LED chip, and each light-emitting unit comprises a buffer layer, an n-GaN layer, a blue light multi-quantum well layer and a p-GaN layer which are sequentially stacked; each light-emitting unit further comprises a control electrode, and the control electrode comprises a p-type electrode layer and an n-type electrode layer; each light-emitting unit can also be provided with a green photonic crystal structure or a red light body structure which penetrates through the buffer layer and extends to the n-GaN layer to form a green light-emitting unit or a red light-emitting unit, and the light-emitting unit without the photonic crystal structure is a blue light-emitting unit; the three adjacent light-emitting units arranged in the array include a red light-emitting unit, a green light-emitting unit and a blue light-emitting unit.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor nano-display technology, and in particular to a Mini-LED / Micro-LED full-color display device based on photonic crystals and a preparation method thereof. Background Art

[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 need of the market. Mini-LED and micro-LED are new-generation display technologies with self-luminous display characteristics. Compared with organic light-emitting diode (OLED) technology, Mini-LED and Micro-LED display devices have a series of advantages such as higher brightness and stability, higher luminous efficiency, lower power consumption, and faster response time. A series of products have been developed in the fields of TV, flat panel display, mobile phone display, etc.

[0003] The display principle of the display device is to thin-film, miniaturize and array the LED structure design, with a size of only about 1-100 microns, and then form a display array through the array transfer method. However, display technology still faces many key technical difficulties, including the integration of massive devices. Moreover, the reduction in the size of Mini-LED / Micro-LED will also bring about problems such as deterioration of device performance and increased manufacturing difficulty. For example, the traditional Mini-LED / Micro-LED full-color preparation process requires the preparation of red, green and blue monochrome Micro-LED pixels separately before transfer, which not only increases the manufacturing cost of the Mini-LED / Micro-LED full-color display device during the screening, testing, packaging and other processes in the manufacturing process; and the prepared red and green monochrome Mini-LED / Micro-LED has low luminous efficiency and low product yield, resulting in the problem of low luminous efficiency and yield of the entire Mini-LED / Micro-LED full-color display device. Summary of the invention

[0004] The present invention provides a Mini-LED / Micro-LED full-color display device based on photonic crystal and a preparation method thereof 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 array.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] The present invention provides a Mini-LED / Micro-LED full-color display device based on photonic crystal, comprising:

[0007] A driving substrate provided with a driving circuit;

[0008] At least three light-emitting units of different colors are bonded to the driving substrate, each of the light-emitting units is processed and prepared by a blue light Mini-LED / Micro-LED chip, and each of the light-emitting units includes a buffer layer, an n-GaN layer, a blue light multi-quantum well layer and a p-GaN layer stacked in sequence; each of the light-emitting units also includes a control electrode, and the control electrode includes a p-type electrode layer and an n-type electrode layer;

[0009] The p-type electrode layer is electrically connected to the p-GaN layer and the driving circuit;

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

[0011] Among the three adjacent light-emitting units of different colors arranged in an array, two of the light-emitting units are also provided with a photonic crystal structure penetrating the buffer layer and extending to the n-GaN layer, the photonic crystal structure including a plurality of crystal holes and quantum dots filled in the crystal holes, wherein 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.

[0012] In one of the embodiments, an isolation structure is further provided between two adjacent light emitting units, and the isolation structure is used to prevent light crosstalk between the light emitted by the two adjacent light emitting units.

[0013] In one of the embodiments, the isolation structure includes a metal light shielding layer and an oxide isolation layer wrapping the metal light shielding layer, and the oxide isolation layer connects the sides of two adjacent light emitting units.

[0014] In one of the embodiments, the p-type electrode layer electrically connects the driving circuit and the p-GaN layer along the side of the light-emitting unit, and the p-type electrode layer is covered by the oxide isolation layer at the side of the light-emitting unit; and / or, the n-type electrode layer electrically connects the driving circuit and the n-GaN layer along the side of the light-emitting unit, and the n-type electrode layer is covered by the oxide isolation layer at the side of the light-emitting unit.

[0015] In one of the embodiments, the side of the light-emitting unit is also covered with a SiO2 layer, one end of the SiO2 layer extends to the n-GaN layer, and the other end of the SiO2 layer 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 with the p-GaN layer; the n-type electrode layer covers the SiO2 layer and one end extends to contact with the n-GaN layer.

[0016] In one embodiment, the crystal hole penetrates the n-GaN layer to the light emitting surface of the blue light multi-quantum well layer.

[0017] In one of the embodiments, in the photonic crystal-based Mini-LED / Micro-LED full-color display device, any three adjacent light-emitting units can emit red light, green light and blue light.

[0018] In a second aspect, the present invention provides a method for preparing a Mini-LED / Micro-LED full-color display device based on photonic crystals, and the method for preparing the Mini-LED / Micro-LED full-color display device comprises the following steps:

[0019] A Mini-LED / Micro-LED chip array is provided, comprising a plurality of blue Mini-LED / Micro-LED chips, each of which comprises 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 comprises a p-type electrode layer and an n-type electrode layer;

[0020] Providing a processing substrate, thinning the sapphire substrate layer of the blue light Mini-LED / Micro-LED chip array by mechanical polishing to expose the GaN buffer layer, and then transferring the blue light Mini-LED / Micro-LED chip array to the processing substrate;

[0021] Prepare crystal holes, using photolithography, electron beam lithography, helium ion microscope-focused ion beam system, inductively coupled plasma etching or nanoimprinting to form a plurality of crystal holes penetrating the buffer layer and extending to the n-GaN layer on the blue light Mini-LED / Micro-LED chip;

[0022] Filling quantum dots: filling green quantum dots or red quantum dots in the crystal holes on different blue Mini-LED / Micro-LED chips by electrodeposition or inkjet printing, so as to ensure that among the three adjacent blue Mini-LED / Micro-LED chips arranged in an array, the quantum dots in one of the blue Mini-LED / Micro-LED chips are red quantum dots, and the quantum dots in another blue Mini-LED / Micro-LED chip are green quantum dots;

[0023] A driving substrate provided with a driving circuit is provided, and the blue light Mini-LED / Micro-LED chip array with the crystal holes and the quantum dots is transferred to the driving substrate by bonding and the processing substrate is peeled off, and 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.

[0024] In one of the embodiments, in the step of providing the Mini-LED / Micro-LED chip array, for the Mini-LED / Micro-LED chip array, an isolation structure is further provided between any two adjacent Mini-LED / Micro-LED chips, and the isolation structure is used to prevent optical crosstalk between the light emitted by two adjacent light-emitting units.

[0025] In one of the embodiments, the isolation structure includes a metal light shielding layer and an oxide isolation layer wrapping the metal light shielding layer, and the oxide isolation layer connects the sides of two adjacent light emitting units.

[0026] It can be seen from the above technical solutions that the embodiments of the present invention have at least the following advantages and positive effects:

[0027] The Mini-LED / Micro-LED full-color display device based on photonic crystals of the embodiments of the present invention and the preparation method thereof, the Mini-LED / Micro-LED full-color display device based on photonic crystals includes an RGB LED unit formed by a driving substrate and at least three light-emitting units, wherein two light-emitting units are provided with a color conversion layer (i.e., a photonic crystal structure) located in a buffer layer and an n-GaN layer, and the remaining light-emitting unit is not provided with a photonic crystal structure. On this basis, in the same RGB LED unit, the red photonic crystal in the red light-emitting unit can convert the blue light emitted by the blue light multi-quantum well layer into red light; the green photonic crystal in the green light-emitting unit can convert the blue light emitted by the blue light multi-quantum well layer into green light; and the blue light multi-quantum well layer in the blue light-emitting unit can emit blue light. This solution controls the light emission of the three colors of RGB within the same RGB LED unit, eliminating the selection step of the RGB three-color LED and reducing the screening cost. Moreover, the three light-emitting units of the present invention are all made of the most efficient and stable blue light Mini-LED / Micro-LED chips on the market, which greatly reduces the huge cost of chip testing and mass transfer caused by 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 high color conversion efficiency (>90%), high stability, and high-quality optical properties with a narrow light-emitting spectrum, which can enable the RGB LED unit to obtain a wider display color gamut and a longer display life, and improve the luminous efficiency and product yield of the Mini-LED / Micro-LED full-color display device. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0029] Figure 1 This is a schematic structural diagram of a Mini-LED / Micro-LED full-color display device according to an embodiment of the present invention;

[0030] Figure 2 for Figure 1 A schematic diagram of the light diffusion structure of a red light emitting unit in the full-color display device shown;

[0031] Figure 3 for Figure 1 A schematic diagram of the light diffusion structure of a green light emitting unit in the full-color display device shown;

[0032] Figure 4 for Figure 1 A schematic diagram of the light diffusion structure of a blue light emitting unit in the full-color display device shown;

[0033] Figure 5 for Figure 1 A schematic diagram of the arrangement of a light-emitting unit array in which any three adjacent light-emitting units emit red, blue and green light in an embodiment of a full-color device is shown;

[0034] Figure 6 for Figure 1 The structural schematic diagram of a single light-emitting unit in the full-color display device shown is shown;

[0035] Figures 7 to 10 This is a diagram of the steps for preparing a Mini-LED / Micro-LED full-color display device according to an embodiment of the present invention.

[0036] The following are the descriptions of the reference numerals:

[0037] 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. GaN buffer layer; 220. n-GaN layer; 230. blue light multi-quantum well layer; 240. GaN cap layer; 250. p-GaN layer; 260. control electrode layer; 261. p-type electrode layer; 262. n-type electrode layer; Polar layer; 270, SiO2 layer; 280, photonic crystal structure; 281, crystal hole; 282, quantum dots; 282a, red quantum dots; 282b, green quantum dots; 300, isolation structure; 310, oxide isolation layer; 320, metal shading 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 DESCRIPTION

[0038] Typical embodiments that embody 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 changes in different embodiments without departing from the scope of the present invention, and the descriptions and illustrations therein are essentially used for illustration purposes rather than for limiting the present invention.

[0039] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0040] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "setting", and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0041] refer to Figure 1 The present invention provides a Mini-LED / Micro-LED full-color display device 10 based on photonic crystals, which includes a driving substrate 100 and at least three light-emitting units 200. The light-emitting units 200 are prepared by processing a blue light Mini-LED / Micro-LED chip 201. The three light-emitting units 200 are arranged in an array and bonded to the driving substrate 100. Moreover, the three light-emitting units 200 form an RGB unit. The three light-emitting units in the same RGB unit can emit red light, green light and blue light respectively, thereby realizing the light emission control of different colors of the same RGB unit, completing the full-color display of RGB, and improving the resolution of the Micro-LED full-color display device 10.

[0042] Please refer to Figures 2 to 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 It shows that when the driving circuit controls the red light emitting unit 200a to work alone, the RGB unit emits red light; Figure 3 It shows that when the driving circuit controls the green light-emitting unit alone, the RGB unit emits green light; Figure 4 It shows that when the driving circuit controls the blue light-emitting unit to work alone, the RGB unit emits blue light. Figure 5, in order to make the Micro-LED full-color display device 10 emit light more uniformly, any three adjacent light-emitting units 200 can emit red light (R), green light (G) and blue light (B), then in the same Micro-LED full-color display device 10, any three adjacent light-emitting units 200 can constitute an RGB unit, and the Micro-LED full-color display device 10 is composed of a plurality of 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, the number of light-emitting units 200 of each color is not limited, and the arrangement positions of light-emitting units 200 of different colors are not limited. It is only necessary to satisfy that at least three light-emitting units 200 of different colors are included in at least the same Micro-LED full-color display device 10 to constitute the three-color light emission of the RGB unit.

[0043] refer to Figure 6 Each light-emitting unit 200 includes a GaN buffer layer 210, an n-GaN layer 220, a blue light multi-quantum well layer 230, a GaN cap layer 240 and a p-GaN layer 250 stacked in sequence. 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 electrically connects the driving circuit and the p-GaN layer 250 along the side of the light-emitting unit 200; the n-type electrode layer 262 electrically connects the driving circuit and the n-GaN layer 220 along the side of the light-emitting unit 200; the SiO2 layer 270 is used as a commonly used blocking isolation layer, and its main functions are to prevent impurity diffusion, dielectric isolation, insulation, etc. In the present application, the SiO2 layer 270 is used on the one hand to block the electrical connection between the hierarchical structure other than the control electrode layer 260 (i.e., the four electrode layers of the n-GaN layer 220, the blue light multi-quantum well layer 230, the GaN cap layer 240 and the p-GaN layer 250) and the driving circuit; on the other hand, the SiO2 layer 270 is used to block the diffusion of impurities between the control electrode layer 260 and other hierarchical electrodes, thereby protecting the control electrode layer 260 and other electrode layer structures. Specifically, Figure 5It is shown that the SiO2 layer 270 is arranged 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 along the side of the light-emitting unit 200. It should be understood that in other embodiments, the GaN capping layer 240 may not be arranged; secondly, the arrangement positions of the p-type electrode layer 261 and the n-type electrode layer 262 are not limited, and they may extend and cover along the side of the light-emitting unit 200, or may be stacked and arranged on opposite sides of the light-emitting unit 200, or may be arranged at other positions of 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; in addition, if the arrangement positions of the p-type electrode layer 261 and the n-type electrode layer 262 are different, the arrangement position of the SiO2 layer 270 will also change accordingly, or may not even be arranged.

[0044] Combined with 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 also provided with a photonic crystal structure 280 that penetrates the buffer layer 210 and extends to the n-GaN layer. The photonic crystal structure 280, as a color conversion layer, 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 a plurality of 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. The light-emitting unit 200 with red photonic crystals 280a is the red light-emitting unit 200a described above; the crystal holes 281 filled with green quantum dots 282b form green photonic crystals 280b. The light-emitting unit 200 with green photonic crystals 280b is the green light-emitting unit 200b described above; the light-emitting unit 200 without the crystal structure 280 is the blue light-emitting unit 200c described above. The red photonic crystal 280a and the green photonic crystal 280b can serve as color conversion layers to convert the blue light emitted by the blue multi-quantum well layer 240 into green light and red light, respectively. Specifically, the red quantum dot 282a and the green quantum dot 282b materials can further absorb the blue light emitted by the blue multi-quantum well layer 240 and confined in the photonic crystal structure 280, thereby converting the absorbed blue light into red and green light and emitting it from the surface of the photonic crystal structure 280, thereby realizing a full-color Micro-LED light source. In addition, the depth and size of the crystal hole 281 can be calculated and designed by simulation software such as FDTD, MPB, and RSoft. The size of the crystal hole 281 is 100nm to 5um, which is enough for the quantum dot 282 material (<10nm) to fill the interior of the crystal hole 281. In the present application, the materials of the red quantum dots 282a and the green quantum dots 282b are II-VI compound semiconductor materials or III-V compound semiconductor materials, wherein the II-VI compound semiconductor materials include CdS, CdSe, CdS / ZnS, CdSe / ZnS or CdSe / CdS / ZnS, and the III-V compound semiconductor materials include InP, InP / ZnSe or InP / ZnSe / ZnS.

[0045] The photonic crystal-based Mini-LED / Micro-LED full-color display device 10 and its preparation method according to the embodiment of the present invention, the photonic crystal-based Mini-LED / Micro-LED full-color display device comprises a driving substrate 100 and an RGB LED unit formed by at least three light-emitting units 200, wherein two light-emitting units 200 are provided with a color conversion layer (i.e., a photonic crystal structure 280) located in a buffer layer 210 and an n-GaN layer 220, and the remaining light-emitting unit 200 is not provided with a photonic crystal structure 280. On this basis, in the same RGB LED unit, the red photonic crystal 280a in the red light-emitting unit 200a can convert the blue light emitted by the blue light multi-quantum well layer 240 into red light; the green photonic crystal 280b in the green light-emitting unit 200b can convert the blue light emitted by the blue light multi-quantum well layer 240 into green light; and the blue light multi-quantum well layer 240 in the blue light-emitting unit 200c can emit blue light. This solution controls the light emission of the three colors of RGB in the same RGB LED unit, eliminating the selection step of the RGB three-color LED and reducing the screening cost in the manufacturing process. Moreover, the three light-emitting units 200 of the present invention are all processed and prepared using the blue light Mini-LED / Micro-LED chip 201 with the highest efficiency and the best stability on the market, which greatly reduces the huge cost required for chip testing and mass transfer due to the low yield of red and green Mini-LED / Micro-LED, and greatly reduces the manufacturing cost; secondly, the quantum dot 282 material in the color conversion layer (photonic crystal structure 280) has high color conversion efficiency (>90%), high stability, and high-quality optical properties with a narrow light emission spectrum, which can make the light emission of the RGB LED unit obtain a wider display color gamut and a longer display life, and improve the light emission efficiency and product yield of the Mini-LED / Micro-LED full-color display device 100.

[0046] In this embodiment, the red photonic crystal 280a and the green photonic crystal 280b both penetrate the n-GaN layer 230 to the light-emitting surface of the blue light multi-quantum well layer 240. This arrangement increases the frequency of blue light being converted in a single light-emitting unit 200 to ensure precise control of the light-emitting color.

[0047] 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 to 4 The isolation structure 300 is used to prevent the light crosstalk between the light emitted by two adjacent light emitting units 200. Specifically, Figure 1As shown, the isolation structure 300 includes an oxide isolation layer 310 and a metal light shielding layer 320. The opposite sides of the oxide isolation layer 310 cover the side periphery of each light-emitting unit 200 (covering the control electrode layer 260) and the side 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 from the upper surface of the driving substrate 100 to the light-emitting surface along the side periphery of each light-emitting unit 200 (through the entire light-emitting unit 200 along the thickness direction of the light-emitting unit 200). It should be understood that the oxide isolation layer 310 and the metal light shielding layer 320 are only an isolation method for preventing optical crosstalk between two adjacent light-emitting units 200. In other embodiments, the isolation structure 300 can use other light-absorbing isolation materials.

[0048] The present invention also provides a method for preparing a Mini-LED / Micro-LED full-color display device 10 based on photonic crystals. The method for preparing the Mini-LED / Micro-LED full-color display device 10 of the present invention comprises the following steps:

[0049] Step S10, reference Figure 7 , providing a Mini-LED / Micro-LED chip array 202 including multiple (at least three) blue light Mini-LED / Micro-LED chips 201, each blue light Mini-LED / Micro-LED chip 201 includes a GaN buffer layer 210, an n-GaN layer 220, a blue light multi-quantum well layer 230, a GaN cap layer 240 and a p-GaN layer 250 and a control electrode 260 stacked on a sapphire substrate 20; the control electrode 260 includes a p-type electrode layer 261 and an n-type electrode layer 262.

[0050] Step S20, combined with reference Figure 8 and Fig. 9 , providing a processing substrate 30, thinning the sapphire substrate 20 layer of the blue light Mini-LED / Micro-LED chip array 202 by mechanical polishing, exposing the GaN buffer layer 210, and then flip-chip transferring the blue light Mini-LED / Micro-LED chip array 202 to the processing substrate 30; wherein, Figure 8 As shown, the control electrode layer 260 is in contact with the upper surface of the processed substrate 30, and the GaN buffer layer 210 is exposed as a light emitting surface.

[0051] Step S30, reference Fig. 9, prepare crystal holes 281, and use photolithography, electron beam lithography, helium ion microscope-focused ion beam system, inductively coupled plasma etching or nanoimprinting to form multiple crystal holes 281 penetrating the buffer layer 210 and extending to the n-GaN layer 220 on the blue light Mini-LED / Micro-LED chip 201.

[0052] Step S40, reference Fig.10 , providing a driving substrate 100 provided with a driving circuit, and using a bonding method to peel off the blue light Mini-LED / Micro-LED chip array 202 with a crystal hole 281 from the processing substrate 40 and transfer it to the driving substrate 100; wherein the p-type electrode layer 261 is electrically connected to the p-GaN layer 250 and the driving circuit, the n-type electrode layer 262 is electrically connected to the n-GaN layer 220 and the driving circuit, and the p-type electrode layer 261 and the n-type electrode layer 262 of the control electrode layer 260 are directly electrically in contact with the driving circuit to form a closed loop, so that a single light-emitting unit 200 can be individually controlled without the need for additional circuit connection design.

[0053] Step S50, reference Figure 1 , filling quantum dots 282, using electrodeposition or inkjet printing to fill red quantum dots 282a or green quantum dots 282b in the crystal holes 281 on different blue light Mini-LED / Micro-LED chips 201, so as to ensure that among the three adjacent blue light Mini-LED / Micro-LED chips 201 arranged in the array, the quantum dots 282 in one of the blue light Mini-LED / Micro-LED chips are red quantum dots 282a, and the quantum dots 282 in another blue light Mini-LED / Micro-LED chip 201 are green quantum dots 282b. Figure 1 The Mini-LED / Micro-LED full-color display device 10 shown in FIG. wherein 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 280 is a blue light-emitting unit 200c.

[0054] It should be explained that the processing order of step S40 and step S50 can be exchanged, that is, the quantum dots 282 are filled first, and then the blue light Mini-LED / Micro-LED chip array 202 with the crystal structure 280 is peeled off from the processing substrate 40 and transferred to the driving substrate 100. In addition, in the Mini-LED / Micro-LED chip array provided in step S10, an isolation structure 300 is also provided between any two adjacent Mini-LED / Micro-LED chips, and the isolation structure 300 is used to prevent the light emitted by the two adjacent light-emitting units 200 from causing optical crosstalk between the two. Specifically, the isolation structure 300 includes a metal shading layer 320 and an oxide isolation layer 310 wrapping the metal shading layer 320, and the oxide isolation layer 310 indirectly connects the sides of the two adjacent light-emitting units 200 through the metal shading layer 320. It should be understood that in other embodiments, the isolation structure 300 can use other light-absorbing isolation materials.

[0055] Although the present invention has been described with reference to several typical embodiments, it should be understood that the terms used are illustrative and exemplary, rather than restrictive. Since the present invention can be embodied in a variety of 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, so all changes 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 provided with a driving circuit; At least three light-emitting units of different colors are bonded to the driving substrate, each of which is processed and prepared by a blue light Mini-LED / Micro-LED chip; each of the light-emitting units includes a buffer layer, an n-GaN layer, a blue light multi-quantum well layer and a p-GaN layer stacked in sequence; each of the light-emitting units also includes a control electrode, and the control electrode 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; Among the three adjacent light-emitting units of different colors arranged in an array, two of the light-emitting units are also provided with a photonic crystal structure penetrating the buffer layer and extending to the n-GaN layer, the photonic crystal structure including a plurality of crystal holes and quantum dots filled in the crystal holes, wherein 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 also provided between two adjacent light emitting units, and the isolation structure is used to prevent light crosstalk between the light emitted by the two adjacent 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 comprises a metal light shielding layer and an oxide isolation layer wrapping the metal light shielding layer, and 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 electrically connects the driving circuit and the p-GaN layer along the side of the light-emitting unit, and the p-type electrode layer is covered by the oxide isolation layer at the side of the light-emitting unit; and / or, the n-type electrode layer electrically connects the driving circuit and the n-GaN layer along the side of the light-emitting unit, and the n-type electrode layer is covered by the oxide isolation layer at the side of the light-emitting unit.

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

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

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

8. A method for preparing a Mini-LED / Micro-LED full-color display device based on photonic crystal, characterized in that: The method for preparing the Mini-LED / Micro-LED full-color display device comprises the following steps: A Mini-LED / Micro-LED chip array is provided, comprising a plurality of blue Mini-LED / Micro-LED chips, each of which comprises 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 comprises a p-type electrode layer and an n-type electrode layer; Providing a processing substrate, thinning the sapphire substrate layer of the blue light Mini-LED / Micro-LED chip array by mechanical polishing to expose the GaN buffer layer, and then transferring the blue light Mini-LED / Micro-LED chip array to the processing substrate; Prepare crystal holes, using photolithography, electron beam lithography, helium ion microscope-focused ion beam system, inductively coupled plasma etching or nanoimprinting to form a plurality of crystal holes penetrating the buffer layer and extending to the n-GaN layer on the blue light Mini-LED / Micro-LED chip; Filling quantum dots: filling green quantum dots or red quantum dots in the crystal holes on different blue Mini-LED / Micro-LED chips by electrodeposition or inkjet printing, so as to ensure that among the three adjacent blue Mini-LED / Micro-LED chips arranged in an array, the quantum dots in one of the blue Mini-LED / Micro-LED chips are red quantum dots, and the quantum dots in another blue Mini-LED / Micro-LED chip are green quantum dots; A driving substrate provided with a driving circuit is provided, and the blue light Mini-LED / Micro-LED chip array with the crystal holes and the quantum dots is transferred to the driving substrate by bonding and the processing substrate is peeled off, and 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 step of providing the Mini-LED / Micro-LED chip array, for the Mini-LED / Micro-LED chip array, an isolation structure is also provided between any two adjacent Mini-LED / Micro-LED chips, and the isolation structure is used to prevent optical 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 comprises a metal light shielding layer and an oxide isolation layer wrapping the metal light shielding layer, and the oxide isolation layer connects the sides of two adjacent light emitting units.

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