Full-color miniature LED display

Abstract

The utility model discloses a full-color miniature LED (light-emitting diode) display. The full-color miniature LED display comprises a substrate and a plurality of light-emitting modules, the light-emitting modules are arranged on the substrate and distributed in an array mode, each light-emitting module comprises at least one blue light Micro-LED unit, at least one red light QD-LED unit and at least one green light QD-LED unit, the substrate comprises a first driving circuit, a second driving circuit and a third driving circuit, and the first driving circuit is connected with the second driving circuit. The first driving circuit is electrically connected with the blue light Micro-LED unit and is used for providing a first driving voltage for the blue light Micro-LED unit, the second driving circuit is electrically connected with the red light QD-LED unit and is used for providing a second driving voltage for the red light QD-LED unit, and the third driving circuit is electrically connected with the green light QD-LED unit and is used for providing a third driving voltage for the green light QD-LED unit. According to the utility model, the technical characteristics of the blue light Micro-LED and the red-green light QD-LED are combined, so that the display effect and the reliability of the full-color micro LED display are better.

Description

Technical Field

[0001] The utility model relates to, in particular to, a full-color micro LED display, belonging to the technical field of micro display. Background Art

[0002] In recent years, Micro-LED display has become a hot research direction, which has quickly attracted the attention of researchers at home and abroad. Compared with ordinary LED lighting technology, the new Micro-LED display based on the third-generation semiconductor GaN has excellent performance such as higher brightness and luminous efficiency, shorter response time, lower energy consumption, longer service life, and smaller size. LED displays in the field of micro-display are highly integrated semiconductor display devices that can realize the integration of display, precise positioning, visible light communication and other sensing functions. It is a new information display technology with great application potential. Micro-LED displays have multiple single-pixel element Micro-LED arrays. Pixels can be tiny lighting areas on a display screen, and images can be composed of many pixels. Pixels are usually arranged in a two-dimensional matrix and represented by dots, squares, rectangles or other shapes. Pixels can be the basic unit of a display or digital image and have geometric coordinates. When forming a full-color image, a pixel can be composed of multiple sub-pixels that emit light of different colors, and each sub-pixel can be controlled or driven to emit light of different colors. When manufacturing a full-color LED display, due to the different manufacturing processes or materials of LEDs of different colors, the sub-pixels that emit light of different colors are made separately, and then the sub-pixels are integrated to form a full-color pixel.

[0003] The existing full-color display technology solutions mainly include material growth, mass transfer technology and color conversion technology. Due to the difficulty of material growth (especially red light LED) and the limitation of epitaxial size, material growth technology can hardly be applied to small-size displays; the high cost of mass transfer technology (such as high transfer cost and maintenance cost), production efficiency and yield issues make mass transfer technology face huge challenges in its widespread commercial application; in addition, color conversion technology is also faced with many difficulties in terms of device efficiency, stability and life because it is limited by the attenuation and degradation of the efficiency and stability of red and green quantum dots under high temperature and strong blue light environment. Utility Model Content

[0004] The main purpose of the utility model is to provide a full-color micro LED display, thereby overcoming the deficiencies in the prior art.

[0005] In order to achieve the above-mentioned utility model purpose, the technical solution adopted by the utility model includes:

[0006] The utility model provides a full-color micro-LED display, which includes: a substrate and a plurality of light-emitting modules, wherein the plurality of light-emitting modules are disposed on the substrate and arranged in an array, each of the light-emitting modules includes at least one blue light Micro-LED unit, at least one red light QD-LED unit and at least one green light QD-LED unit, the substrate includes a first drive circuit, a second drive circuit and a third drive circuit, the first drive circuit is electrically connected to the blue light Micro-LED unit and is used to provide a first drive voltage to the blue light Micro-LED unit, the second drive circuit is electrically connected to the red light QD-LED unit and is used to provide a second drive voltage to the red light QD-LED unit, the third drive circuit is electrically connected to the green light QD-LED unit and is used to provide a third drive voltage to the green light QD-LED unit, wherein the first drive voltage is greater than the second drive voltage and the third drive voltage.

[0007] Further, the blue light Micro-LED unit includes a conductive bonding layer, a blue light Micro-LED semiconductor structure layer and an electrode layer, and the blue light Micro-LED semiconductor structure layer is electrically connected to the first driving circuit via the bonding layer and the electrode layer;

[0008] The red light QD-LED unit comprises a first anode, a red light QD-LED semiconductor structure layer and a first cathode, and the red light QD-LED semiconductor structure layer is electrically connected to the second driving circuit via the first anode and the first cathode;

[0009] The green light QD-LED unit includes a second anode, a green light QD-LED semiconductor structure layer and a second cathode, and the green light QD-LED semiconductor structure layer is electrically connected to the third driving circuit via the second anode and the second cathode;

[0010] Wherein, the bonding layer, the first anode and the second anode are integrated.

[0011] Furthermore, the bonding layer, the first anode and the second anode are an integrated conductive material layer, a plurality of avoidance holes are provided on the conductive material layer, the first contact of the first driving circuit, the second contact of the second driving circuit and the third contact of the third driving circuit are respectively exposed in one of the avoidance holes, and the electrode layer, the first cathode and the second cathode are respectively electrically connected to the first contact, the second contact and the third contact corresponding to those exposed in the avoidance holes.

[0012] Furthermore, the full-color micro LED display also includes a passivation structure layer, which is distributed between the electrode layer and the blue light Micro-LED semiconductor structure layer, between the electrode layer and the conductive material layer, between the first cathode and the red light QD-LED semiconductor structure layer, between the first cathode and the conductive material layer, between the second cathode and the green light QD-LED semiconductor structure layer, and between the second cathode and the conductive material layer.

[0013] Furthermore, the semiconductor structure layers of at least one blue light Micro-LED unit, at least one red light QD-LED unit and at least one green light QD-LED unit included in each of the light-emitting modules are isolated from each other.

[0014] Furthermore, an isolation groove or an insulating isolation structure layer is provided between the semiconductor structure layers of at least one of the blue light Micro-LED units, at least one of the red light QD-LED units and at least one of the green light QD-LED units included in each of the light-emitting modules, and the semiconductor structure layers of the blue light Micro-LED unit, the red light QD-LED unit and the green light QD-LED unit are isolated from each other via the isolation groove or the isolation structure layer.

[0015] In a more specific implementation manner, the plurality of light-emitting modules are isolated from each other.

[0016] Furthermore, an isolation groove or an insulating isolation structure layer is provided between two adjacent light-emitting modules, and the two adjacent light-emitting modules are isolated from each other via the isolation groove or the isolation structure layer.

[0017] Furthermore, the isolation structure layer is formed by transforming the blue light Micro-LED semiconductor structure layer or the red light QD-LED semiconductor structure layer or the green light QD-LED semiconductor structure layer after ion implantation.

[0018] Furthermore, the isolation groove is formed by etching away a portion of the blue light Micro-LED semiconductor structure layer or the red light QD-LED semiconductor structure layer or the green light QD-LED semiconductor structure layer.

[0019] In another more specific embodiment, the blue light Micro-LED semiconductor structure layer also has a step structure, and adjacent blue light Micro-LED units are electrically isolated by the step structure, so that adjacent blue light Micro-LED units can be driven independently.

[0020] Furthermore, the blue light Micro-LED semiconductor structure layer includes a first doped semiconductor layer, an active layer, and a second doped semiconductor layer stacked in sequence on the bonding layer, the passivation structure layer is arranged on the second doped semiconductor layer, the active layer, the first doped semiconductor layer, and a portion of the bonding layer, the height of the step structure is not less than the thickness of the second doped semiconductor layer and less than or equal to the thickness of the blue light Micro-LED semiconductor structure layer, and the step structure at least electrically isolates the second doped semiconductor layers of adjacent blue light Micro-LED units.

[0021] Furthermore, the blue light Micro-LED unit further includes a reflector layer and a transparent conductive layer, wherein the reflector layer is stacked on the bonding layer, the transparent conductive layer is stacked on the reflector layer, the first doped semiconductor layer is stacked on the transparent conductive layer, and the reflector layer also has a connection hole penetrating through the reflector layer along its thickness direction, and a part of the bonding layer passes through the connection hole and is electrically connected to the transparent conductive layer.

[0022] Furthermore, the reflector layer is a Bragg reflector.

[0023] Furthermore, the red light QD-LED semiconductor structure layer and the green light QD-LED semiconductor structure layer both include a hole injection layer, a hole transport layer, a quantum dot light-emitting layer, an electron transport layer, and an electron injection layer stacked in sequence, the first anode / the second anode is electrically connected to the hole injection layer, the first cathode / the second cathode is electrically connected to the electron injection layer, and the passivation structure layer is arranged on the hole injection layer, the hole transport layer, the quantum dot light-emitting layer, the electron transport layer, and a portion of the first anode / the second anode.

[0024] Compared with the prior art, the advantages of the utility model include:

[0025] The utility model provides a full-color micro LED display that combines the technical features of blue light Micro-LED and red and green light QD-LED, achieving a combination of the advantages of full-color micro LED display in terms of display effect and reliable performance;

[0026] The QD-LED unit in a full-color micro LED display provided by the utility model is an active light-emitting display technology, which can be individually controlled by driving and directly used as an active light-emitting point without the need for strong blue light excitation. At the same time, the operating temperature is relatively low, and the QD-LED starting voltage is relatively smaller. The high temperature and strong blue light environment in the color conversion technology is avoided in the light-emitting mechanism. The utility model can combine the stability advantages of blue light Micro-LED and red and green light QD-LED to solve the stability problem in the existing color conversion technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a top view of a full-color micro LED display provided in a typical implementation case of the utility model;

[0028] Figure 2 It is a top view of another full-color micro LED display provided in a typical implementation case of the utility model;

[0029] Figure 3 yes Figure 2 A cross-sectional view formed along BB;

[0030] Figure 4-Figure 10 They are respectively schematic diagrams of an intermediate structure formed in a production process of a full-color micro LED display provided in a typical implementation case of the utility model. DETAILED DESCRIPTION

[0031] In view of the deficiencies in the prior art, the inventor of this case has proposed the technical solution of the utility model after long-term research and extensive practice. The following will further explain the technical solution, its implementation process and principle, etc. in conjunction with the accompanying drawings and specific implementation cases.

[0032] Although specific configurations and arrangements are discussed, it should be understood that this is done for illustrative purposes only. Therefore, other configurations and arrangements may be used without departing from the scope of the present invention. Moreover, the present invention may also be adopted in a variety of other applications. The functions and structural features described in the present invention may be combined, adjusted and modified with each other in a variety of ways not specifically shown in the accompanying drawings, so that these combinations, adjustments and modifications are within the scope of the present invention.

[0033] In general, terms may be understood at least in part based on usage in context. For example, the term "one or more" as used herein may be used to describe any component, structure, or feature in the singular, or may be used to describe a combination of components, structures, or features in the plural, depending at least in part on the context. Similarly, terms such as "one," "an," or "the" may also be understood to convey singular usage or to convey plural usage, depending at least in part on the context. Additionally, the term "based on..." may be understood to not necessarily be intended to convey a set of exclusive factors, but may instead allow for the presence of additional factors that may not necessarily be explicitly described, depending at least in part on the context.

[0034] It should be easily understood that the meanings of “on,” “over,” and “on” in the present invention should be interpreted in the broadest manner, so that “on” means not only “directly on something,” but also means “on something” including the presence of intermediate components or layers therebetween, and “on something” or “on something” means not only “on something” or “on something,” but also includes the meaning of “on something” or “on something” without any intermediate components or layers therebetween (i.e., directly on something).

[0035] Additionally, for ease of description, spatially relative terms such as "below," "beneath," "lower," "above," "upper," etc. may be used herein to describe the relationship of one element or component to another element or component illustrated in the drawings. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the drawings. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly.

[0036] The term "layer" as used herein refers to a material portion including an area with a certain thickness. The layer can extend over the entire lower or upper structure, or can have a degree less than the scope of the lower or upper structure. In addition, the layer can be a region of a homogeneous or inhomogeneous continuous structure, and its thickness is less than the thickness of the continuous structure. For example, the layer can be located between the top surface and the bottom surface of the continuous structure or between any pair of horizontal planes therebetween. The layer can extend horizontally, vertically and / or along a tapered surface. The substrate can be a layer, one or more layers can be included therein, and / or one or more layers can be provided thereon, above and / or below. A layer can include multiple layers. For example, the semiconductor layer can include one or more doped or undoped semiconductor layers, and can have the same or different materials.

[0037] Different from the quantum dot photoluminescence mechanism in color conversion technology, quantum dot electroluminescent diode QD-LED is a device that electrically excites quantum dots to emit light. It is an active light-emitting display technology based on the principle of quantum dot electroluminescence. It directly acts as a light-emitting point and does not require the use of a blue light excitation chip. Quantum dot electroluminescent diode QD-LED has no photon absorption step, which can effectively reduce energy loss and improve the quantum efficiency within the device. It has excellent luminous efficiency, color purity, reliability, etc., and has good development potential and broad application prospects in the display field.

[0038] Due to the surface effect of quantum dots, the surface functionalization of quantum dots, that is, reasonable surface modification, has a significant impact on their application and performance optimization. Usually, the stability and luminous efficiency of quantum dots can be improved by improving the shell structure and surface functionalization of quantum dots, and the application field of quantum dots can be effectively broadened. The optical properties of colloidal quantum dots with different ligands of the same structure may be almost the same. When two QDs are applied to quantum dot light-emitting diodes QD-LED with the same device structure, the electrical properties of the two may show great differences (the EQE of the two may differ by nearly 100 times). It can be seen that compared with the optical performance, the selection of ligands on the surface of quantum dots has a more important impact on the performance of quantum dot light-emitting diodes QD-LED. For example, when focusing on the improvement of the electrochemical stability of quantum dots in device operation in practice, electrochemically inert ligands can be selected to balance the optical and electrical properties of the surface quantum dots. For example, according to the preparation process requirements of the device (such as spin coating, inkjet printing, photolithography, etc.), quantum dots need to be stably dispersed in a specific medium to meet the feasibility of the process, which also needs to be achieved through reasonable surface modification. In addition to performance optimization from the perspective of quantum dots, the operating voltage of the device can be controlled by designing new quantum dot electroluminescent diodes QD-LEDz carrier injection layers, transport layers and other functional layers and electrode materials, thereby avoiding leakage current and improving the overall optoelectronic performance of the device.

[0039] The utility model provides a full-color micro-LED display and a manufacturing method thereof that have the advantages of both Micro-LED and QD-LED technologies, optimizes the full-color light-emitting diode device structure, and helps to improve the application performance of the full-color micro-display.

[0040] The utility model combines the technical characteristics of blue light Micro-LED and red and green light QD-LED to achieve the advantages of full-color micro LED display in terms of display effect and reliable performance. The process means involved include but are not limited to spin coating, inkjet printing, photolithography, etching, etc.

[0041] See also Figure 1 and Figure 2, a full-color micro-LED display, comprising: a substrate and a plurality of light-emitting modules A formed on the substrate, each of the light-emitting modules A comprising a blue light Micro-LED unit 300, a red light QD-LED unit 400 and a green light QD-LED unit 500, the substrate comprising a first driving circuit, a second driving circuit and a third driving circuit, the first driving circuit being electrically connected to the blue light Micro-LED unit 300 and used to provide a first driving voltage to the blue light Micro-LED unit 300, the second driving circuit being electrically connected to the red light QD-LED unit 400 and used to provide a second driving voltage to the red light QD-LED unit 400, the third driving circuit being electrically connected to the green light QD-LED unit 500 and used to provide a third driving voltage to the green light QD-LED unit 500, wherein the first driving voltage is greater than the second driving voltage and the third driving voltage.

[0042] It should be noted that the first driving circuit, the second driving circuit and the third driving circuit all work independently, and each blue light Micro-LED unit 300, each red light QD-LED unit 400 and each green light QD-LED unit 500 can be driven independently, so that each blue light Micro-LED unit 300, each red light QD-LED unit 400, each green light QD-LED unit 500 independently serves as a functional micro LED pixel.

[0043] For details, please refer to Figure 3 , Figure 3 yes Figure 2 The cross-sectional view formed along BB, Figure 3 , the overall structure of the blue light Micro-LED unit 300 , the red light QD-LED unit 400 , and the green light QD-LED unit 500 in cooperation with the substrate 100 is shown.

[0044] Specifically, the blue light Micro-LED unit 300 includes a conductive bonding layer 210, a blue light Micro-LED semiconductor structure layer 310, a first passivation structure layer 610 and an electrode layer 320, wherein the bonding layer 210 is disposed on the substrate 100, and the bonding layer 210 is electrically connected to the first driving circuit of the substrate 100, the blue light Micro-LED semiconductor structure layer 310 is disposed on the bonding layer 330, the first passivation structure layer 610 is disposed on a portion of the blue light Micro-LED semiconductor structure layer 310 and a portion of the bonding layer 210, the electrode layer 320 is disposed on a portion of the blue light Micro-LED semiconductor structure layer 310 and a portion of the first passivation structure layer 610, and the electrode layer 320 is electrically connected to the blue light Micro-LED semiconductor structure layer 310 and the first driving circuit of the substrate 100, respectively;

[0045] The red QD-LED unit 400 includes a first anode 220, a red QD-LED semiconductor structure layer 410, a second passivation structure layer 620, and a first cathode 420. The first anode 220 is disposed on the substrate 100 and is electrically connected to the second driving circuit of the substrate 100. The red QD-LED semiconductor structure layer 410 is disposed on the first anode 220. The second passivation structure layer 620 is disposed on a portion of the red QD-LED semiconductor structure layer 410 and a portion of the first anode 220. The first cathode 420 is disposed on a portion of the red QD-LED semiconductor structure layer 410 and a portion of the second passivation structure layer 620. The first cathode 420 is electrically connected to the red QD-LED semiconductor structure layer 410 and the second driving circuit of the substrate 100, respectively.

[0046] The green QD-LED unit 500 includes a second anode 230, a green QD-LED semiconductor structure layer 510, a third passivation structure layer 630, and a second cathode 520. The second anode 230 is disposed on the substrate 100 and is electrically connected to the third driving circuit of the substrate 100. The green QD-LED semiconductor structure layer 510 is disposed on the second anode 230. The third passivation structure layer 630 is disposed on a portion of the green QD-LED semiconductor structure layer 510 and a portion of the second anode 230. The second cathode 520 is disposed on a portion of the green QD-LED semiconductor structure layer 510 and a portion of the third passivation structure layer 630. The second cathode 520 is electrically connected to the green QD-LED semiconductor structure layer 510 and the third driving circuit of the substrate 100, respectively.

[0047] The bonding layer 210 , the first anode 220 , and the second anode 230 are integrated, and the bonding layer 210 , the first anode 220 , and the second anode 230 are part of the conductive material layer 200 .

[0048] Specifically, a plurality of avoidance holes are provided on the conductive material layer 200, and the first contact of the first driving circuit, the second contact of the second driving circuit, and the third contact of the third driving circuit are respectively exposed in one of the avoidance holes, and the electrode layer 320, the first cathode 420, and the second cathode 430 are electrically connected to the first contact, the second contact, and the third contact correspondingly from the avoidance holes.

[0049] Figure 1 and Figure 2A top view of an exemplary blue Micro-LED unit 300, a red QD-LED unit 400, and a green QD-LED unit 500 is shown, and a substrate 100 has a driving circuit formed therein for driving the blue Micro-LED unit 300, the red QD-LED unit 400, and the green QD-LED unit 500. Contacts of the driving circuit are exposed on one side of the blue Micro-LED unit 300, the red QD-LED unit 400, and the green QD-LED unit 500.

[0050] Specifically, substrate 100 refers to a material on which subsequent material layers are added. Substrate 100 itself can be patterned. The material added to the top of the substrate can be patterned or can remain unpatterned. In some embodiments, substrate 100 may include semiconductor materials such as silicon, silicon carbide, gallium nitride, germanium, gallium arsenide, indium phosphide. In some embodiments, substrate 100 may be made of a non-conductive material such as glass, plastic or sapphire wafer. In some embodiments, substrate 100 may have a driving circuit formed therein, and substrate 100 may be a CMOS backplane or a TFT glass substrate. The driving circuit provides an electrical signal to the LED unit (the LED unit in this case can be regarded as a collective term for a blue light Micro-LED unit 300, a red light QD-LED unit 400, and a green light QD-LED unit 500) to control the brightness. In some embodiments, the driving circuit may include an active matrix driving circuit, wherein each individual LED unit corresponds to an independent driver. In some embodiments, the driving circuit may include a passive matrix driving circuit, wherein a plurality of LED units are arranged in an array and connected to a data line and a scan line driven by the driving circuit.

[0051] Specifically, the material of the conductive material layer 200 is a conductive material with an adhesive effect. More specifically, the material of the conductive material layer 200 may include Au, Sn, In, Cu or Ti. It should be understood that the description of the material of the conductive material layer 200 is only exemplary and not restrictive. Those skilled in the art may make changes as required, and all these changes are within the scope of the present application.

[0052] In a specific embodiment, the blue light Micro-LED semiconductor structure layer 310 includes a first doped semiconductor layer, an active layer, and a second doped semiconductor layer stacked in sequence on the bonding layer 210, the first doped semiconductor layer is electrically connected to the bonding layer 210, the electrode layer 220 is electrically connected to the second doped semiconductor layer, and the electrode layer 220 is electrically isolated from the first doped semiconductor layer, the active layer, and the bonding layer 210 by the first passivation structure layer 610.

[0053] In some embodiments, the first doped semiconductor layer and the second doped semiconductor layer may include one or more layers based on IIVI materials (such as ZnSe or ZnO) or IIIV nitride materials (such as GaN, AlN, InN, InGaN, GaP, AlInGaP, AlGaAs and alloys thereof). In some embodiments, the first doped semiconductor layer may be a p-type semiconductor layer that extends across multiple blue light Micro-LED units 300 and forms a common anode for these blue light Micro-LED units 300. In some embodiments, the thickness of the first doped semiconductor layer may be between about 0.05 μm and about 1 μm. In some other embodiments, the thickness of the first doped semiconductor layer may be between about 0.05 μm and about 0.7 μm. In some alternative embodiments, the thickness of the first doped semiconductor layer may be between about 0.05 μm and about 0.5 μm. By having a continuous thin layer of the first doped semiconductor on each blue light Micro-LED unit 300, the bonding area between the substrate 100 and the plurality of blue light Micro-LED units 300 is not limited to the area below the second doped semiconductor layer, but also extends to the area between the respective blue light Micro-LED units 300. In other words, by having a continuous thin layer of the first doped semiconductor, the area of ​​the bonding layer is increased. Therefore, the bonding strength between the substrate 100 and the plurality of blue light Micro-LED units 300 is enhanced, and the risk of blue light Micro-LED structure peeling can be reduced.

[0054] In some embodiments, the first doped semiconductor layer may be p-type GaN. In some embodiments, the first doped semiconductor layer may be formed by doping GaN with magnesium (Mg). In some embodiments, the first doped semiconductor layer may be p-type InGaN. In some embodiments, the first doped semiconductor layer may be p-type AlInGaP. Each LED unit has an anode and a cathode connected to a drive circuit, for example, the drive circuit is formed in the substrate 100 (the drive circuit is not explicitly shown in the figure). For example, each blue light Micro-LED unit 300 has an anode connected to a constant voltage source and a cathode connected to the source / drain of the drive circuit. In other words, by forming a continuous first doped semiconductor across each blue light Micro-LED unit 300, multiple blue light Micro-LED units 300 have a common anode formed by a first doped semiconductor layer and a bonding layer.

[0055] In some embodiments, the second doped semiconductor layer can be an n-type semiconductor layer and forms the cathode of each blue light Micro-LED unit 300. In some embodiments, the second doped semiconductor layer can be n-type GaN. In some embodiments, the second doped semiconductor layer can be n-type InGaN. In some embodiments, the second doped semiconductor layer can be n-type AlInGaP. The second doped semiconductor layers of different blue light Micro-LED units 300 are electrically isolated, so each blue light Micro-LED unit 300 can have a cathode with a different voltage level than other units. As a result of the disclosed embodiments, multiple independently operable blue light Micro-LED units 300 are formed, whose first doped semiconductor layers extend horizontally across adjacent blue light Micro-LED units 300, and whose second doped semiconductor layers are electrically isolated between adjacent blue light Micro-LED units 300.

[0056] In some embodiments, the active layer is a multi-quantum well (MQW) layer. In some embodiments, the thickness of the first doped semiconductor layer and the second doped semiconductor layer may be between about 0.3 μm and about 5 μm. In some other embodiments, the thickness of the first doped semiconductor layer, the active layer and the second doped semiconductor layer may be between about 0.4 μm and about 4 μm, preferably between 0.5 μm and about 3 μm.

[0057] Specifically, the first passivation structure layer 610 can also be used to protect and isolate the blue light Micro-LED unit 300. In some embodiments, the material of the first passivation structure layer 610 may include SiO2, Al2O3, SiN or other suitable materials. In some embodiments, the material of the first passivation structure layer 610 may include polyimide, SU8 photoresist or other photo-patternable polymers. The electrode layer 320 is formed on a portion of the first passivation structure layer 610, and the electrode layer 320 is electrically connected to the second doped semiconductor layer through the opening on the first passivation structure layer 610.

[0058] Specifically, the blue light Micro-LED unit 300 also includes a reflector layer and a transparent conductive layer, the reflector layer is stacked on the bonding layer 210, the transparent conductive layer is stacked on the reflector layer, the first doped semiconductor layer is stacked on the transparent conductive layer, and the reflector layer also has a connection hole that penetrates itself along its thickness direction, and a part of the bonding layer 210 passes through the connection hole and is electrically connected to the transparent conductive layer. The reflector layer is formed on the bonding layer 210 to reflect the light emitted by the blue light Micro-LED unit 300. In some embodiments, the reflector layer can be a distributed Bragg reflector (DBR). In some embodiments, the reflector layer can include multiple pairs of TiO2 / SiO2 layers or multiple pairs of SiO2 / HfO2 layers. In some embodiments, the reflector layer can include 3 to 10 pairs of TiO2 / SiO2 layers or 3 to 10 pairs of SiO2 / HfO2 layers. More specifically, the shape of the connection hole can be a regular shape such as a circle or a square, or it can be an irregular shape. In some embodiments, the axial direction of the connecting hole may be perpendicular to the plane where the reflector layer is located, or may be inclined to form a certain angle with the plane where the reflector layer is located.

[0059] Specifically, the structures of the red light QD-LED unit 400 and the green light QD-LED unit 500 may be the same, especially the structures of the red light QD-LED semiconductor structure layer 410 and the green light QD-LED semiconductor structure layer 510 are the same, and the difference between the two mainly lies in the different quantum dot light-emitting layers contained in the red light QD-LED semiconductor structure layer 410 and the green light QD-LED semiconductor structure layer 510. Specifically, the red light QD-LED semiconductor structure layer 410 and the green light QD-LED semiconductor structure layer 510 both include a hole injection layer, a hole transport layer, a quantum dot light-emitting layer, an electron transport layer, and an electron injection layer stacked in sequence, the first anode 220 / the second anode 230 is electrically connected to the hole injection layer, the first cathode 420 / the second cathode 520 is electrically connected to the electron injection layer, the second passivation structure layer 620 / the third passivation structure layer 630 is arranged on a portion of the first anode 220 / the second anode 230, the hole injection layer, the hole transport layer, the quantum dot light-emitting layer, the electron transport layer, and the electron injection layer, the second passivation structure layer 620 / the third passivation structure layer 630 can electrically isolate the first cathode 420 / the second cathode 520, and can also electrically isolate adjacent red light QD-LED units 400 and / or green light QD-LED units 500.

[0060] Specifically, the first passivation structure layer 610, the second passivation structure layer 620, and the third passivation structure layer 630 may be integrally arranged. In some embodiments, the material of the second passivation structure layer 620 / the third passivation structure layer 630 may include SiO2, Al2O3, SiN or other suitable materials. In some embodiments, the material of the second passivation structure layer 620 / the third passivation structure layer 630 may include polyimide, SU8 photoresist or other photo-patternable polymers.

[0061] More specifically, the functional layers in the red light QD-LED unit 400 and the green light QD-LED unit 500 are stacked, and the good film-forming quality of each functional layer will inevitably make other layers, such as the upper electrode, more uniform and flat, thereby making the carrier injection and transmission of the quantum dot light-emitting diode stable and uniform over the entire surface, ultimately making the quality of the quantum dot electroluminescent diode more excellent.

[0062] In one specific embodiment, an isolation groove is formed between the blue light Micro-LED unit 300, the red light QD-LED unit 400, and the green light QD-LED unit 500, and the semiconductor structure layers of the blue light Micro-LED unit 300, the red light QD-LED unit 400, and the green light QD-LED unit 500 are electrically isolated by the isolation groove. In another specific embodiment, an isolation structure layer is formed between the blue light Micro-LED unit 300, the red light QD-LED unit 400, and the green light QD-LED unit 500, and the blue light Micro-LED unit 30 0. The semiconductor structure layers of the red QD-LED unit 400 and the green QD-LED unit 500 are electrically isolated by an isolation structure layer. Specifically, the isolation structure layer may be an isolation material layer formed of an insulating material such as SiO2, Al2O3, or SiN. Alternatively, the isolation structure layer may be an insulating structure layer formed by ion implantation of any one of the blue Micro-LED semiconductor structure layer 310, the red QD-LED semiconductor structure layer 410, and the green QD-LED semiconductor structure layer 510. These are processes known to those skilled in the art and are not specifically limited here.

[0063] More specifically, the plurality of LED units include a plurality of blue light Micro-LED units 300, a plurality of red light QD-LED units 400, and a plurality of green light QD-LED units 500. More specifically, the plurality of blue light Micro-LED units 300, the plurality of red light QD-LED units 400, and the plurality of green light QD-LED units 500 are respectively distributed in arrays, and the plurality of blue light Micro-LED units 300 are combined to form a plurality of blue light Micro-LED arrays sequentially arranged along a first direction, and each blue light Micro-LED array includes a plurality of blue light Micro-LEDs sequentially arranged along a second direction. Unit 300, a plurality of red light QD-LED units 400 are combined to form a plurality of red light QD-LED arrays arranged in sequence along a first direction, each red light QD-LED array includes a plurality of red light QD-LED units 400 arranged in sequence along a second direction, a plurality of green light QD-LED units 500 are combined to form a plurality of green light QD-LED arrays arranged in sequence along a first direction, each green light QD-LED array includes a plurality of green light QD-LED units 500 arranged in sequence along the second direction, and a blue light Micro-LED array, a green light QD-LED array and a red light QD-LED array are alternately arranged in sequence along the first direction.

[0064] See also Figure 4-Figure 10 In a more specific implementation case, a method for manufacturing a full-color micro LED display may include the following steps:

[0065] 1) Please refer to Figure 4 A second doped semiconductor layer, an active layer, and a first doped semiconductor layer are sequentially formed on a substrate 700, and the second doped semiconductor layer, the active layer, and the first doped semiconductor layer form a blue light Micro-LED semiconductor structure layer 310; and a substrate 100 is provided, and the substrate 100 includes a driving circuit and a plurality of contacts electrically connected to the driving circuit.

[0066] Specifically, the substrate 700 is selected from a base material suitable for forming a blue light Micro-LED semiconductor structure layer. For example, the material of the substrate can be a non-conductive material such as glass, plastic or sapphire wafer, but is not limited thereto; the substrate 100 can be made of semiconductor materials such as silicon, silicon carbide, gallium nitride, germanium, gallium arsenide, indium phosphide, etc. Of course, the substrate 100 can also be made of non-conductive materials such as glass, plastic or sapphire wafer. In this embodiment, the substrate 100 can be a CMOS backplane or a TFT glass substrate 100, etc. The driving circuit is used to provide an electrical signal to the blue light Micro-LED unit 300 and the red light QD-LE D unit 400 and green QD-LED unit 500 to control brightness; in this embodiment, the driving circuit may include an active matrix driving circuit, wherein each individual blue Micro-LED unit 300, red QD-LED unit 400 and green QD-LED unit 500 is equivalent to an independent driver, in this embodiment, the driving circuit may include a passive matrix driving circuit, wherein multiple blue Micro-LED units 300, multiple red QD-LED units 400 and multiple green QD-LED units 500 are distributed in an array and connected to data lines and scan lines driven by the driving circuit.

[0067] In some specific embodiments, chemical vapor deposition (CVD), physical vapor deposition (PVD), atomic layer deposition (ALD), plasma enhanced CVD (PECVD), plasma enhanced ALD (PEALD) and other processes can be used to form the second doped semiconductor layer, the active layer, and the first doped semiconductor layer; exemplarily, the material of the first doped semiconductor layer and the second doped semiconductor layer can be IIVI material (such as ZnSe or ZnO) or IIIV nitride material (such as GaN, AlN, InN, InGaN, GaP, AlInGaP, AlGaAs and alloys thereof), the first doped semiconductor layer can be a P-type semiconductor layer serving as an anode, and in this embodiment, the thickness of the first doped semiconductor layer is 0.05 μm-1 μm, preferably 0.05 μm-0.7 μm, and particularly preferably 0.05 μm-0.5 μm; exemplarily, the first doped semiconductor layer can be formed by doping GaN The first doped semiconductor layer is formed by doping magnesium (Mg). In other implementation cases, the first doped semiconductor layer can also be P-type InGaN, P-type AlInGaP, etc.; in this implementation case, the second doped semiconductor layer can be an N-type semiconductor layer, and the second doped semiconductor layer serves as the cathode of each LED unit; in this implementation case, the second doped semiconductor layer can be N-type GaN, N-type InGaN, N-type AlInGaP, etc.; in this implementation case, the active layer (i.e., MQW layer) is the active area of ​​the LED semiconductor layer. In this implementation case, the thickness of the Micro-LED semiconductor layer (the first doped semiconductor layer, the MQW layer, and the second doped semiconductor layer) is 0.4μm-4μm, preferably 0.5μm-3μm; of course, the first doped semiconductor layer can also be an N-type semiconductor layer. Accordingly, when the first doped semiconductor layer is an N-type semiconductor layer, the second doped semiconductor layer is a P-type semiconductor layer.

[0068] 2) Please refer to Figure 5 , forming a conductive material layer 200 on the first doped semiconductor layer and the substrate 100, and bonding the substrate 100 to the blue light Micro-LED semiconductor structure layer 310 through the conductive material layer 200. Exemplarily, the material of the conductive material layer 200 may be metal or metal alloy, for example, the material of the conductive material layer 200 may be Au, Sn, In, Cu or Ti, etc.; it should be understood that the description of the material of the conductive material layer 200 is only exemplary and not restrictive, and those skilled in the art may make changes as required, and all these changes are within the scope of the present application;

[0069] 3) Please refer to Figure 6, removing the substrate, the method of removing the substrate may be implemented by direct stripping or other methods known to those skilled in the art; of course, after removing the substrate, a thinning operation may be performed on the second doped semiconductor layer to remove a portion of the second doped semiconductor layer; in some embodiments, the thinning operation may include a dry etching or a wet etching operation, and in some embodiments, the thinning operation may also include a chemical mechanical polishing (CMP) operation, etc.;

[0070] 4) Please refer to Figure 7 , a portion of the second doped semiconductor layer can be removed by etching or the like, thereby forming a step structure, wherein the step structure separates the second doped semiconductor layer to form a plurality of Micro-LED table tops, each Micro-LED table top corresponds to a blue light Micro-LED unit, and an isolation groove or an isolation structure layer is formed between two adjacent Micro-LED table tops to electrically isolate the two adjacent Micro-LED table tops, and the blue light Micro-LED semiconductor structure layer located in the selected area is removed to expose the conductive material layer 200, and the selected area is subsequently used to make a QD-LED unit, wherein the height of the step structure is not less than the thickness of the second doped semiconductor layer and less than or equal to the thickness of the Micro-LED semiconductor layer, and the step structure at least isolates the second doped semiconductor layers of adjacent Micro-LED units from each other, wherein the step surface of the step structure serves as the light-emitting area of ​​the blue light Micro-LED semiconductor structure layer.

[0071] It can be understood that the step structure penetrates the second doped semiconductor layer along the thickness direction, thereby achieving isolation of the second doped semiconductor layer; or, part of the step structure penetrates the second doped semiconductor layer and the active layer along the thickness direction, or, part of the step structure penetrates the second doped semiconductor layer, the active layer and the first doped semiconductor layer along the thickness direction.

[0072] Specifically, the thickness of the Micro-LED semiconductor layer including the first doped semiconductor layer, the active layer and the second doped semiconductor layer can be between about 0.3μm and about 5μm. In some other embodiments, the thickness of the blue light Micro-LED semiconductor structure layer including the first doped semiconductor layer, the active layer and the second doped semiconductor layer can be between about 0.4μm and about 4μm. In some alternative embodiments, the thickness of the Micro-LED semiconductor layer including the first doped semiconductor layer, the active layer and the second doped semiconductor layer can be between about 0.5μm and about 3μm.

[0073] 5) Please refer to Figure 8a , Figure 8bA hole injection layer, a hole transport layer, a quantum dot light-emitting layer, an electron transport layer, and an electron injection layer are sequentially stacked on the conductive material layer 200 after the blue light Micro-LED semiconductor structure layer is removed to form a red light QD-LED semiconductor structure layer 410 and a green light QD-LED semiconductor structure layer 510. The conductive material layer 200 located at the bottom of the red light QD-LED semiconductor structure layer 410 and the green light QD-LED semiconductor structure layer 510 serves as a common anode of the red light QD-LED unit and the green light QD-LED unit.

[0074] It should be noted that the difference between the red light QD-LED semiconductor structure layer 410 and the green light QD-LED semiconductor structure layer 510 mainly lies in the different quantum dot light-emitting layers, and isolation grooves or isolation structures are also formed between the blue light Micro-LED semiconductor structure layer 310, the red light QD-LED semiconductor structure layer 410, and the green light QD-LED semiconductor structure layer 510.

[0075] 6) Please refer to Figure 9a , Figure 9b , a portion of the conductive material layer 200 covering the contacts of the substrate 100 is removed to form an escape hole exposing the contacts.

[0076] 7) Please refer to Fig.10 A first passivation structure layer 610 is formed on the surface of the formed blue light Micro-LED semiconductor structure layer 310, a second passivation structure layer 620 is formed on the surface of the red light QD-LED semiconductor structure layer 410, and a third passivation structure layer 630 is formed on the surface of the green light QD-LED semiconductor structure layer 510, and an opening is formed on the first passivation structure layer 610 so that a portion of the second doped semiconductor layer and a contact of the first drive circuit are respectively exposed from an opening, and an opening is formed on the second passivation structure layer 620 so that a portion of the electron transport layer of the red light QD-LED semiconductor structure layer 410 and a contact of the second drive circuit are respectively exposed from an opening, and a portion of the electron transport layer of the green light QD-LED semiconductor structure layer 510 and a contact of the third drive circuit are respectively exposed from an opening.

[0077] It should be noted that the first passivation structure layer 610, the second passivation structure layer 620 and the third passivation structure layer 630 may be a continuous thin film structure formed integrally, and the materials of the first passivation structure layer 610, the second passivation structure layer 620 and the third passivation structure layer 630 may be SiO2, Al2O3, SiN or other suitable materials, and the materials of the first passivation structure layer 610, the second passivation structure layer 620 and the third passivation structure layer 630 may also include polyimide, SU8 photoresist or other photo-patternable polymers, etc.;

[0078] 8) An electrode layer 320 is formed on the first passivation structure layer 610, and the electrode layer 320 is electrically connected to the second doped semiconductor layer and the contacts of the first drive circuit from the openings on the first passivation structure layer 610, and the first drive circuit on the substrate 100 can control the voltage and current of the second doped semiconductor layer through the electrode layer 320; specifically, the electrode layer 320 is electrically isolated from other structural layers except the second doped semiconductor layer through the first passivation structure layer 610, and accordingly, a first cathode 420 is formed on the second passivation structure layer 620, and the first cathode 420 is electrically connected to the electron transport layer and the contacts of the second drive circuit from the openings on the second passivation structure layer 620, and a second cathode 520 is formed on the third passivation structure layer 630, and the second cathode 520 is electrically connected to the electron transport layer and the contacts of the third drive circuit from the openings on the third passivation structure layer 630.

[0079] Specifically, the electrode layer and the first cathode and the second cathode may be made of a conductive material such as indium tin oxide (ITO), Cr, Ti, Pt, Au, Al, Cu, Ge or Ni.

[0080] It should be understood that the above embodiments are only for illustrating the technical concept and features of the utility model, and their purpose is to enable people familiar with the technology to understand the content of the utility model and implement it accordingly, and they cannot be used to limit the protection scope of the utility model. Any equivalent changes or modifications made according to the spirit of the utility model should be included in the protection scope of the utility model.

Claims

1. A full-color micro LED display, characterized in that: include: A substrate and a plurality of light-emitting modules, wherein the plurality of light-emitting modules are disposed on the substrate and arranged in an array, each of the light-emitting modules comprises at least one blue light Micro-LED unit, at least one red light QD-LED unit and at least one green light QD-LED unit, and the substrate comprises a first driving circuit, a second driving circuit and a third driving circuit, wherein the first driving circuit is electrically connected to the blue light Micro-LED unit and is used to provide a first driving voltage to the blue light Micro-LED unit, the second driving circuit is electrically connected to the red light QD-LED unit and is used to provide a second driving voltage to the red light QD-LED unit, the third driving circuit is electrically connected to the green light QD-LED unit and is used to provide a third driving voltage to the green light QD-LED unit, wherein the first driving voltage is greater than the second driving voltage and the third driving voltage.

2. The full-color micro LED display according to claim 1, characterized in that: The blue light Micro-LED unit includes a conductive bonding layer, a blue light Micro-LED semiconductor structure layer and an electrode layer, and the blue light Micro-LED semiconductor structure layer is electrically connected to the first driving circuit via the bonding layer and the electrode layer; The red light QD-LED unit comprises a first anode, a red light QD-LED semiconductor structure layer and a first cathode, and the red light QD-LED semiconductor structure layer is electrically connected to the second driving circuit via the first anode and the first cathode; The green light QD-LED unit includes a second anode, a green light QD-LED semiconductor structure layer and a second cathode, and the green light QD-LED semiconductor structure layer is electrically connected to the third driving circuit via the second anode and the second cathode; Wherein, the bonding layer, the first anode and the second anode are integrated.

3. The full-color micro LED display according to claim 2, characterized in that: The bonding layer, the first anode and the second anode are an integrated conductive material layer, and a plurality of avoidance holes are provided on the conductive material layer. The first contact of the first driving circuit, the second contact of the second driving circuit and the third contact of the third driving circuit are respectively exposed in one of the avoidance holes, and the electrode layer, the first cathode and the second cathode are respectively electrically connected to the first contact, the second contact and the third contact corresponding to those exposed in the avoidance holes.

4. The full-color micro LED display according to claim 3, characterized in that: The full-color micro LED display also includes a passivation structure layer, which is distributed between the electrode layer and the blue light Micro-LED semiconductor structure layer, between the electrode layer and the conductive material layer, between the first cathode and the red light QD-LED semiconductor structure layer, between the first cathode and the conductive material layer, between the second cathode and the green light QD-LED semiconductor structure layer, and between the second cathode and the conductive material layer.

5. The full-color micro LED display according to claim 3, characterized in that: The semiconductor structure layers of at least one blue light Micro-LED unit, at least one red light QD-LED unit and at least one green light QD-LED unit included in each of the light-emitting modules are isolated from each other.

6. The full-color micro LED display according to claim 5, characterized in that: An isolation groove or an insulating isolation structure layer is also provided between the semiconductor structure layers of at least one blue light Micro-LED unit, at least one red light QD-LED unit and at least one green light QD-LED unit included in each of the light-emitting modules, and the units are isolated from each other through the isolation groove or the insulating isolation structure layer.

7. The full-color micro LED display according to claim 2, characterized in that: The multiple light-emitting modules are isolated from each other.

8. The full-color micro LED display according to claim 7, characterized in that: An isolation groove or an insulating isolation structure layer is further provided between any two adjacent light-emitting modules, and the modules are isolated from each other via the isolation groove or the isolation structure layer.

9. The full-color micro LED display according to claim 6 or 8, characterized in that: The isolation structure layer is formed by converting the blue light Micro-LED semiconductor structure layer or the red light QD-LED semiconductor structure layer or the green light QD-LED semiconductor structure layer after ion implantation; and / or, the isolation groove is formed by etching away a portion of the blue light Micro-LED semiconductor structure layer or the red light QD-LED semiconductor structure layer or the green light QD-LED semiconductor structure layer.

10. The full-color micro LED display according to claim 4, characterized in that: The blue light Micro-LED semiconductor structure layer has a step structure, and adjacent blue light Micro-LED units are electrically isolated by the step structure, so that the adjacent blue light Micro-LED units can be driven independently.

11. The full-color micro LED display according to claim 10, characterized in that: The blue light Micro-LED semiconductor structure layer includes a first doped semiconductor layer, an active layer, and a second doped semiconductor layer stacked in sequence on the bonding layer, the passivation structure layer is arranged on the second doped semiconductor layer, the active layer, the first doped semiconductor layer, and a portion of the bonding layer, the height of the step structure is not less than the thickness of the second doped semiconductor layer and less than or equal to the thickness of the blue light Micro-LED semiconductor structure layer, and the step structure at least electrically isolates the second doped semiconductor layers of adjacent blue light Micro-LED units.

12. The full-color micro LED display according to claim 11, characterized in that: The blue light Micro-LED unit also includes a reflector layer and a transparent conductive layer, the reflector layer is stacked on the bonding layer, the transparent conductive layer is stacked on the reflector layer, the first doped semiconductor layer is stacked on the transparent conductive layer, and the reflector layer also has a connection hole that penetrates itself along its thickness direction, and a part of the bonding layer passes through the connection hole and is electrically connected to the transparent conductive layer.

13. The full-color micro LED display according to claim 12, characterized in that: The reflector layer is a Bragg reflector.

14. The full-color micro LED display according to claim 4, characterized in that: The red light QD-LED semiconductor structure layer and the green light QD-LED semiconductor structure layer both include a hole injection layer, a hole transport layer, a quantum dot light-emitting layer, an electron transport layer, and an electron injection layer stacked in sequence, the first anode / the second anode is electrically connected to the hole injection layer, the first cathode / the second cathode is electrically connected to the electron injection layer, and the passivation structure layer is arranged on the hole injection layer, the hole transport layer, the quantum dot light-emitting layer, the electron transport layer, and a portion of the first anode / the second anode.

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