A vehicle-mounted visible light communication system and its application based on Micro-LED

Abstract

The present invention discloses a vehicle-mounted visible light communication system based on Micro-LED and its application. Among them, the Micro-LED array chip is composed of a periodic arrangement of single devices driven by independent addressing, and the size and shape of the devices are not limited. The Micro-LED device includes a substrate epitaxial layer, a current spreading layer, a passivation layer and an electrode. The present invention uses the Micro-LED array chip as both a light transmitter and a light receiver for visible light communication, and applies it to vehicles or transportation facilities to build a vehicle-mounted visible light communication system consisting of a Micro-LED light transmitter, a free space environment and a Micro-LED light receiver. Through high-speed, bidirectional and parallel visible light communication between vehicles and vehicles, and vehicles and transportation facilities, a multi-terminal online shared data link network is constructed to realize real-time information interaction between users and users, and users and the Internet, while providing high-speed optical communication transmission, it also has lighting display functions to improve resource utilization.

Description

Technical Field

[0001] The present invention belongs to the technical field of visible light communication, and specifically, relates to a vehicle-mounted visible light communication system based on Micro-LED and its application. Background Art

[0002] With the rapid development of wireless communication and big data technology, the requirements for communication capacity and data transmission rate are increasing day by day. Radio frequency communication is gradually facing problems such as tight spectrum resources and limited transmission power. In order to achieve high-quality communication, it is urgent to seek new directions. Visible light communication (VLC) is a new wireless communication technology that uses visible light as a transmission medium. It has been proven to have the advantages of high security and confidentiality, low power consumption, and strong anti-electromagnetic interference. Compared with traditional radio frequency communication, visible light has a higher frequency and a corresponding wider spectrum range. It does not need to occupy existing communication resources and can combine lighting with communication. It is an ideal choice for data communication.

[0003] Currently, visible light communication based on light-emitting diodes (LEDs) and laser diodes (LDs) is commonly used, and LEDs or LDs are commonly used at the transmitting end, and photodiodes are commonly used at the receiving end. However, commercial LEDs have limitations in terms of modulation bandwidth and transmission rate; LD devices still face many challenges in terms of laser lighting safety and optical scalability. To overcome this dilemma, researchers introduced Micro-LEDs into visible light communication systems.

[0004] In recent years, intelligent driving technology is an important branch of the development of communication and Internet of Things technology, and the application of visible light communication in the field of smart transportation is also a major research direction. In-vehicle visible light communication often uses vehicle headlights and taillights as communication light sources, building a huge high-speed communication network between vehicles and vehicles and between vehicles and infrastructure, providing efficient data connection and security for traffic signal violations, curve assistance, vehicle lane change, parking assistance, collision warning, etc. Communication range and delay time are key indicators of vehicle communication safety performance. Compared with Micro-LED devices, conventional light-emitting devices lack obvious advantages in the application of in-vehicle visible light communication.

[0005] Therefore, considering that Micro-LED has the characteristics of high bandwidth, high current density and high-speed parallel communication, it is necessary to further improve the performance of Micro-LED so that it can be combined with in-vehicle applications to achieve fast and efficient signal response and provide a safe and reliable solution for smart transportation. Summary of the invention

[0006] The purpose of the present invention is to solve the above-mentioned problems in the prior art and to provide a vehicle-mounted visible light communication system based on Micro-LED and its application.

[0007] Technical solution: To solve the above technical problems, the technical solution adopted by the present invention is:

[0008] In a first aspect, a Micro-LED device is provided, including a substrate, an epitaxial layer structure, a current spreading layer, a passivation layer, and a p-type electrode layer and an n-type electrode layer;

[0009] The epitaxial layer structure is grown on a substrate and includes, from bottom to top, a GaN buffer layer, an n-GaN layer, an InGaN / GaN superlattice structure layer, an InGaN / GaN multi-quantum well layer, a p-AlGaN electron blocking layer and a p-GaN layer;

[0010] The current spreading layer is arranged on the p-GaN layer;

[0011] The n-GaN layer is exposed by photolithography and etching the current spreading layer, the p-GaN layer, the p-AlGaN electron blocking layer, the InGaN / GaN multi-quantum well layer, the InGaN / GaN superlattice structure layer and part of the n-GaN layer to form a protruding mesa;

[0012] The p-type electrode layer is electrically connected to the current spreading layer, and the n-type electrode layer is electrically connected to the n-GaN layer;

[0013] The passivation layer is wrapped around the table and the exposed surface of the n-GaN layer, playing the role of isolating the electrodes.

[0014] In some embodiments, the current spreading layer is formed by electron beam evaporation or magnetron sputtering process;

[0015] In some embodiments, the current spreading layer is made of an indium tin oxide (ITO) film or a nickel / gold (Ni / Au) metal layer, which forms a good ohmic contact with p-GaN;

[0016] In some embodiments, the p-type electrode layer and the n-type electrode layer are formed by sputtering a metal such as titanium / gold (Ti / Au);

[0017] In some embodiments, the passivation layer is realized by depositing SiO2, Si3N4, Al2O3 materials by PECVD or PVD;

[0018] In some embodiments, the material of the substrate is sapphire, Si, SiC, GaN or GaAs.

[0019] In some embodiments, the size of the mesa is less than 100 μm, and the shape includes but is not limited to circular or square.

[0020] In some embodiments, the substrate thickness is 430 μm; the thickness of the unintentionally doped GaN buffer layer is 2-3 μm; the thickness of the n-GaN layer is 2-3 μm; the thickness of the InGaN / GaN superlattice structure layer is 200-300 nm; the thickness of the InGaN / GaN multiple quantum well layer is 100-200 nm; the thickness of the p-AlGaN electron blocking layer is 20-100 nm; the thickness of the p-GaN layer is 100 nm; the thickness of the current spreading layer is 100 nm; the thickness of the passivation layer is 0.2 μm; and the thickness of the p-type electrode layer and the n-type electrode layer are both 0.2 μm.

[0021] In a second aspect, a Micro-LED array device is provided, in which the Micro-LED devices driven by independent addressing are periodically distributed and arranged, wherein the size of a single Micro-LED device in the Micro-LED array device can be freely set.

[0022] In some embodiments, a distance between two adjacent Micro-LED devices is less than 500 μm.

[0023] In a third aspect, a Micro-LED array chip is provided, which is formed by bonding and packaging the Micro-LED array device and the CMOS drive control circuit.

[0024] In a third aspect, the application of the Micro-LED array chip, the Micro-LED array device or the Micro-LED device as an optical transmitter and / or optical receiver of a visible light communication system is provided.

[0025] In a fourth aspect, a vehicle-mounted visible light communication system based on Micro-LED is provided, comprising:

[0026] The Micro-LED array chip is used as both a light transmitter and a light receiver for visible light communication and is applied to vehicles or transportation facilities to build an on-vehicle visible light communication system consisting of a Micro-LED light transmitter, a free space environment and a Micro-LED light receiver. Through high-speed, bidirectional and parallel visible light communication between vehicles and vehicles, and vehicles and transportation facilities, a multi-terminal online shared data link network is constructed to achieve real-time information interaction between users and users, and between users and the Internet.

[0027] In some embodiments, the vehicle-mounted visible light communication system based on Micro-LED, the transmitting end of the vehicle-mounted visible light communication system includes a transmission signal input control module, a light transmitter based on a Micro-LED array chip and a focusing lens; the receiving end includes a focusing lens, a light receiver based on a Micro-LED array chip and a signal receiving processing module; the visible light transmission channel is a free space environment;

[0028] The Micro-LED array chip adopts on-off keying (OOK) or orthogonal frequency division multiplexing (OFDM) modulation, combined with a multiple-input multiple-output (MIMO) system to achieve high-speed two-way visible light communication, expand communication capacity and improve communication transmission rate and responsiveness.

[0029] The Micro-LED array device of the present invention is composed of distributed and arranged individual devices (pixels), each pixel can be independently addressed and driven. The light-emitting size of the array device ranges from 1 μm to 100 μm, the size and shape can be freely set, and the pixel pitch is less than 500 μm.

[0030] The structure of the Micro-LED device includes a substrate epitaxial layer, a current spreading layer, a passivation layer, and a metal layer. The device preparation is mainly based on III-V compound semiconductors such as GaN, GaP, and GaAs as epitaxial materials. The present invention takes the GaN-based Micro-LED as an example. The substrate material can be a sapphire (Al2O3) substrate, a Si substrate, a SiC substrate, a GaAs substrate, and a GaN substrate. The embodiment of the present invention takes a sapphire substrate as an example.

[0031] The present invention discloses a Micro-LED array device that can be used as both a light transmitter and a light receiver for visible light communication, thereby realizing a bidirectional visible light communication function. The above-mentioned Micro-LED device has the characteristics of high modulation bandwidth and high communication rate, and can be used as a light transmitter to send light signals; at the same time, since the Micro-LED device responds to visible light in a specific band, it can also be used as a photodetector to convert the received light signal into an electrical signal. The -3 dB modulation bandwidth of a single Micro-LED light emitting device can reach the GHz level, and the -3 dB modulation bandwidth of a single Micro-LED light receiving device can reach hundreds of MHz.

[0032] According to the disclosed embodiment, the second aspect of the present invention discloses a vehicle-mounted visible light communication system application technology based on Micro-LED. The main scheme is as follows:

[0033] The vehicle-mounted visible light communication system of the present invention includes a transmitting end based on a Micro-LED light transmitter, a transmission channel, and a receiving end based on a Micro-LED light receiver. The transmitting end mainly includes a transmission signal input control module, a Micro-LED light transmitter array, and a focusing lens, etc.; the receiving end mainly includes a focusing lens, a Micro-LED light receiver array, and a signal receiving and processing module; the transmission channel is a free space environment.

[0034] The above-mentioned visible light communication Micro-LED array chip, which integrates signal transmission and information reception functions, can adopt on-off keying (OOK) or orthogonal frequency division multiplexing (OFDM) modulation, combined with a multiple-input multiple-output (MIMO) system to achieve high-speed two-way visible light communication, thereby expanding communication capacity and improving communication transmission rate and responsiveness.

[0035] The above-mentioned array chips based on Micro-LED can be arranged in the light-emitting positions of vehicles and traffic facilities, including vehicle headlights and taillights, traffic lights, traffic signs and various traffic cameras. The focusing lens can be designed in the outer cover of the headlight or the shell of other light-emitting devices through process integration. While providing on-board visible light communication, the Micro-LED array chip still has the function of lighting display, which greatly reduces resource consumption and reduces product costs.

[0036] Therefore, the Micro-LED-based in-vehicle visible light communication solution of the present invention utilizes Micro-LED arrays of different sizes below 100 μm as both light-emitting devices and detection devices, and is applied to vehicles or transportation facilities. Through high-speed two-way visible light communication between vehicles and vehicles, and vehicles and transportation facilities, the Internet of Things communication transmission between users and users, and users and devices is realized, providing an application solution for vehicle network communication, traffic safety and intelligent driving.

[0037] The present invention has developed a dedicated Micro-LED chip that combines high-speed parallel visible light communication and green lighting, providing a hardware guarantee for the application of Internet of Vehicles communication, safe driving and smart transportation. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A schematic diagram of the cross-sectional structure of a GaN-based Micro-LED single device according to a specific embodiment of the present invention;

[0039] Figure 2 A schematic top view of a GaN-based Micro-LED array device according to a specific embodiment of the present invention;

[0040] Figure 3A flowchart of a bidirectional visible light communication process based on a Micro-LED light emitter array and a light receiver array according to a specific embodiment of the present invention;

[0041] Figure 4 A schematic diagram of a model in which a Micro-LED array chip according to a specific embodiment of the present invention acts as both a light transmitter and a light receiver to realize in-vehicle bidirectional visible light communication;

[0042] Figure 5 The application effect of the Micro-LED array proposed by the present invention on vehicles and transportation facilities;

[0043] Figure 6 This is a schematic diagram of the application of Micro-LED-based in-vehicle visible light communication proposed by the present invention;

[0044] In the figure: substrate 1; epitaxial layer structure: GaN buffer layer 2, n-GaN layer 3, superlattice structure layer 4, InGaN / GaN multi-quantum well layer 5, p-AlGaN electron blocking layer 6 and p-GaN layer 7; current spreading layer 8; passivation layer 9; p-type electrode layer 10; n-type electrode layer 11; visible light communication first end 12 and second end 13; first Micro-LED array chip 14 and second Micro-LED array chip 15; first focusing optical lens 16 and second focusing optical lens 17. Specific implementation methods

[0045] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

[0046] In the description of the present invention, "several" means more than one, "many" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, and "above", "below", "within", etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0047] In the description of the present invention, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0048] The present invention discloses a vehicle-mounted visible light communication system and application based on Micro-LED, taking GaN-based Micro-LED as an example of bidirectional visible light communication with light transmitter and light receiver. The specific embodiments proposed herein are only used to explain the present invention, but not to limit the present invention. In addition, for the convenience of explanation, only the parts related to the present invention are shown in the drawings instead of all structures.

[0049] Example 1 Figure 1 As shown, a Micro-LED device includes a substrate 1, an epitaxial layer structure, a current spreading layer 8, a passivation layer 9, a p-type electrode layer 10, and an n-type electrode layer 11;

[0050] The epitaxial layer structure is grown on a substrate 1, and includes, from bottom to top, a GaN buffer layer 2, an n-GaN layer 3, an InGaN / GaN superlattice structure layer 4, an InGaN / GaN multi-quantum well layer 5, a p-AlGaN electron blocking layer 6 and a p-GaN layer 7;

[0051] The current spreading layer 8 is arranged on the p-GaN layer 7;

[0052] The n-GaN layer 3 is exposed by photolithography and etching the current spreading layer 8, the p-GaN layer 7, the p-AlGaN electron blocking layer 6, the InGaN / GaN multi-quantum well layer 5, the InGaN / GaN superlattice structure layer 4 and part of the n-GaN layer 3, thereby forming a protruding mesa;

[0053] The p-type electrode layer 10 is electrically connected to the current spreading layer 8 , and the n-type electrode layer 11 is electrically connected to the n-GaN layer 3 ;

[0054] The passivation layer 9 wraps around the mesa and the exposed surface of the n-GaN layer 3 to play the role of isolating the electrodes.

[0055] The Micro-LED device is formed by growing different semiconductor epitaxial layers on a substrate 1, and the epitaxial preparation can be carried out by MOCVD. The material of the substrate 1 can be sapphire, Si, SiC, GaN, GaAs, etc. The embodiment of the present invention takes a c-plane sapphire substrate as an example. The epitaxial layer structure includes from bottom to top: an unintentionally doped GaN buffer layer 2, an n-GaN layer 3, an InGaN / GaN superlattice structure layer 4, an InGaN / GaN multi-quantum well layer 5, an unintentionally doped p-AlGaN electron blocking layer 6 and a p-GaN layer 7. Then, a current expansion layer 8 is prepared on the p-GaN layer 7 by electron beam evaporation or magnetron sputtering process. The current expansion layer 8 can use an indium tin oxide (ITO) film or a nickel / gold (Ni / Au) metal layer with low resistivity and high transmittance to form a good ohmic contact with p-GaN. After a series of processes such as photolithography, etching and thermal annealing are performed on the epitaxial wafer, a table with a size less than 100 μm is formed. The shape of the table is not limited, including but not limited to circular or square. Reference numeral 9 represents a passivation layer 9, which can be achieved by depositing SiO2, Si3N4, Al2O3 materials by PECVD or PVD, and plays the role of isolating electrodes. Finally, a p-type electrode layer 10 and an n-type electrode layer 11 are formed by sputtering metals such as titanium / gold (Ti / Au), respectively, wherein the p-type electrode layer 10 is connected to the current spreading layer 8, and the n-type electrode layer 11 is connected to the n-GaN layer 3. In some embodiments, the substrate 1 has a thickness of 430 μm; the thickness of the unintentionally doped GaN buffer layer 2 is 2-3 μm; the thickness of the n-GaN layer 3 is 2-3 μm (Si doping concentration 2×10 18 cm -3 ); the thickness of the InGaN / GaN superlattice structure layer 4 is 200-300 nm (the In component is controllable); the thickness of the InGaN / GaN multi-quantum well layer 5 is 100-200 nm (the In component is controllable); the thickness of the p-AlGaN electron blocking layer 6 is 20-100 nm (Mg doping concentration is 1×10 19 cm -3 , Al composition is controllable); the thickness of p-GaN layer 7 is 100 nm (Mg doping concentration is 1×10 19 cm -3 ); the thickness of the current spreading layer 8 is 100 nm; the thickness of the passivation layer 9 is 0.2 μm; the thickness of the p-type electrode layer 10 and the n-type electrode layer 11 are both 0.2 μm.

[0056] Example 2

[0057] A Micro-LED array device is provided, wherein the Micro-LED devices described in Example 1 are periodically distributed and arranged, wherein the size of a single Micro-LED device in the Micro-LED array device can be freely set.

[0058] In some embodiments, Figure 2 As shown, the Micro-LED array device is periodically arranged by independently addressing and driving individual devices. In this embodiment, the size of a single device is less than 100 μm, and the distance between two adjacent Micro-LED devices is less than 500 μm.

[0059] Example 3

[0060] A Micro-LED array chip is formed by bonding and packaging the Micro-LED array device described in Example 2 and a CMOS drive control circuit.

[0061] In terms of light emission, the Micro-LED array device can emit light in a top-mounted or flip-chip manner. In some embodiments, in order to obtain greater light emission power and resolution, the device of the embodiment emits light in a flip-chip manner, that is, a reflector is attached above the p-type electrode layer 10 so that light is emitted from the substrate area. At the same time, under the flip-chip process, the CMOS drive control circuit can achieve good bonding with the Micro-LED array to form a flip-chip packaged Micro-LED array chip.

[0062] The present invention discloses a Micro-LED array device that can be used as both a light transmitter and a light receiver for visible light communication, thereby realizing a bidirectional visible light communication function. The above-mentioned Micro-LED device has the characteristics of high modulation bandwidth and high communication rate, and can be used as a light transmitter to emit light signals; at the same time, since the Micro-LED device responds to visible light in a specific band, it can also be used as a photodetector to convert the received light signal into an electrical signal. The -3 dB modulation bandwidth of a single Micro-LED light emitting device can reach the GHz level, and the -3 dB modulation bandwidth of a single Micro-LED light receiving device can reach hundreds of MHz.

[0063] Example 3

[0064] The above-mentioned Micro-LED array chip, Micro-LED array device or Micro-LED device is used as an optical transmitter and / or optical receiver of a visible light communication system.

[0065] Micro-LED array-based light emitters and light receivers. Figure 3The present invention is a flowchart of a bidirectional visible light communication process based on a Micro-LED light emitter array and a light receiver array under a specific embodiment.

[0066] Figure 3 The dotted box areas marked with numbers 12 and 13 represent the two sides 12 and 13 of visible light communication respectively. Both communicating parties can have the functions of transmitting and receiving at the same time to achieve two-way communication. The transmitting end mainly includes components such as a signal input module, a light transmitter and a lens. The signal input module mainly includes functions such as electrical signal input, signal amplification bias, signal modulation coding and optical signal driving. The light transmitter is an arrayed Micro-LED device, and the lens is mainly used for optical focusing. The receiving end is mainly composed of a lens, a light receiver and a signal receiving module. The light receiver is a photodetector based on a Micro-LED array, and the signal receiving module mainly includes functions such as signal amplification, signal decoding analysis, and electrical signal output.

[0067] The above-mentioned visible light communication mainly adopts OOK modulation based on single carrier modulation. In order to improve the transmission of parallel signals and increase the transmission rate, OFDM modulation technology based on multi-carrier multiplexing technology is often used. At the same time, MIMO technology can be combined to improve the parallel communication rate. The visible light transmission channel between the transmitter and the receiver can be any free space environment.

[0068] Example 4

[0069] A vehicle-mounted visible light communication system based on Micro-LED, comprising:

[0070] The above-mentioned Micro-LED array chip is used as both an optical transmitter and an optical receiver for visible light communication and applied to vehicles or transportation facilities to build an on-vehicle visible light communication system consisting of a Micro-LED optical transmitter, a free space environment and a Micro-LED optical receiver. Through high-speed, bidirectional and parallel visible light communication between vehicles and vehicles, and vehicles and transportation facilities, a multi-terminal online shared data link network is constructed to realize real-time information interaction between users and users, and users and the Internet.

[0071] Figure 4A schematic diagram of a model in which a Micro-LED array chip under a specific embodiment of the present invention is used as both a light transmitter and a light receiver to realize vehicle-mounted bidirectional visible light communication. In the vehicle-mounted visible light communication system model of the present invention, reference numerals 14 and 15 represent a first Micro-LED array chip 14 and a second Micro-LED array chip 15. In this example model, the Micro-LED array device simultaneously serves as a high-bandwidth light transmitter and a high-performance photodetector to realize multi-channel bidirectional parallel communication. The first focusing optical lens 16 and the second focusing optical lens 17 are respectively placed at the light transmitter end and the light receiver end. In the Micro-LED array, the Micro-LED emitting device under active drive can convert the electrical signal response of the system front-end signal input module into an optical signal and emit it, and send it to the channel space through the lens. At the same time, in the same array or independently of the transmitter array, the Micro-LED detection device under active drive can receive the optical signal transmitted in the external channel, and process and generate an electrical signal response, which is transmitted to the signal receiving module at the back end. The two channels are independent of each other and can work simultaneously to realize high-speed parallel bidirectional communication.

[0072] The above-mentioned Micro-LED array also has the characteristic of self-power supply when working as a photoelectric detector, and can complete the detection function without the help of external power supply, which has obvious advantages in controlling energy consumption.

[0073] Micro-LED array chips can be placed in the light-emitting locations of vehicles and traffic facilities, including vehicle headlights and taillights, traffic lights, traffic signs, and various traffic cameras. The focusing lens can be designed in the outer cover of the headlight or the outer shell of other light-emitting devices through process integration. Micro-LED array chips can provide lighting and display functions while providing on-board visible light communication, achieving efficient use of resources and reducing product costs.

[0074] Figure 5 This is the application effect of the Micro-LED array proposed in the present invention on vehicles and traffic facilities. In the vehicle light source display position, such as the headlights and taillights of the car; in traffic facilities, such as high-speed cameras, Micro-LED devices are used to replace or be independent of traditional LED light source devices, so that a good communication channel can be established between the vehicle and the equipment, and real-time information transmission can be achieved. In a specific embodiment, the focusing lens can be designed through process integration inside the outer cover of the headlight or the outer shell of other light-emitting devices. While providing optical communication, Micro-LED still has the function of lighting display, which can achieve efficient use of resources.

[0075] Figure 6This is a schematic diagram of the application of Micro-LED-based in-vehicle visible light communication proposed by the present invention. As shown in the figure, both the moving vehicle and the traffic light are equipped with a Micro-LED-based in-vehicle visible light communication device. The application of Micro-LED visible light communication enables two-way transmission of information between vehicles and between vehicles and traffic lights, thereby building a multi-terminal online shared data link network, realizing real-time information interaction between users and users, and between users and the Internet, and providing hardware guarantee for the application of Internet of Vehicles communication, safe driving and smart transportation.

[0076] The above is a further detailed description of the present invention in combination with a specific preferred embodiment, but the embodiments of the present invention are not limited to the above embodiments. For ordinary technicians in the technical field to which the present invention belongs, they can make several simple deductions or substitutions without departing from the concept of the present invention, which should be regarded as belonging to the protection scope determined by the present invention.

Claims

1. A Micro-LED device, characterized in that: It includes a substrate, an epitaxial layer structure, a current spreading layer, a passivation layer, a p-type electrode layer, and an n-type electrode layer; The epitaxial layer structure is grown on a substrate and includes, from bottom to top, a GaN buffer layer, an n-GaN layer, an InGaN / GaN superlattice structure layer, an InGaN / GaN multi-quantum well layer, a p-AlGaN electron blocking layer and a p-GaN layer; The current spreading layer is arranged on the p-GaN layer; The n-GaN layer is exposed by photolithography and etching the current spreading layer, the p-GaN layer, the p-AlGaN electron blocking layer, the InGaN / GaN multi-quantum well layer, the InGaN / GaN superlattice structure layer and part of the n-GaN layer to form a protruding mesa; The p-type electrode layer is electrically connected to the current spreading layer, and the n-type electrode layer is electrically connected to the n-GaN layer; The passivation layer is wrapped around the table and the exposed surface of the n-GaN layer, playing the role of isolating the electrodes.

2. The Micro-LED device according to claim 1, characterized in that: The current spreading layer is formed by electron beam evaporation or magnetron sputtering process; And / or, the material of the current spreading layer is an indium tin oxide film or a nickel / gold metal layer, which forms a good ohmic contact with p-GaN; and / or, the p-type electrode layer and the n-type electrode layer are formed by sputtering metal; And / or, the passivation layer is realized by depositing SiO2, Si3N4, Al2O3 material by PECVD or PVD; And / or, the material of the substrate is sapphire, Si, SiC, GaN or GaAs.

3. The Micro-LED device according to claim 1, characterized in that: The size of the mesa is less than 100 μm, and the shape includes but is not limited to circular or square.

4. The Micro-LED device according to claim 1, characterized in that: The substrate thickness is 430 μm; the thickness of the unintentionally doped GaN buffer layer is 2-3 μm; the thickness of the n-GaN layer is 2-3 μm; the thickness of the InGaN / GaN superlattice structure layer is 200-300nm; the thickness of the InGaN / GaN multiple quantum well layer is 100-200 nm; the thickness of the p-AlGaN electron blocking layer is 20-100 nm; the thickness of the p-GaN layer is 100 nm; the thickness of the current spreading layer is 100 nm; the thickness of the passivation layer is 0.2 μm; the thickness of the p-type electrode layer and the n-type electrode layer are both 0.2 μm.

5. A Micro-LED array device, characterized in that: The Micro-LED devices according to any one of claims 1 to 4 are arranged in a periodic distribution.

6. The Micro-LED array device according to claim 5, characterized in that: The distance between two adjacent Micro-LED devices is less than 500 μm.

7. A Micro-LED array chip, characterized in that: The Micro-LED array device according to claim 5 or 6 is bonded and packaged with a CMOS drive control circuit.

8. Use of the Micro-LED array chip according to claim 7, the Micro-LED array device according to claim 5, or the Micro-LED device according to any one of claims 1 to 4 as an optical transmitter and / or optical receiver of a visible light communication system.

9. A vehicle-mounted visible light communication system based on Micro-LED, characterized in that: include: The Micro-LED array chip described in claim 7 is used as both a light transmitter and a light receiver for visible light communication and is applied to vehicles or transportation facilities to build a vehicle-mounted visible light communication system consisting of a Micro-LED light transmitter, a free space environment and a Micro-LED light receiver. Through high-speed, bidirectional and parallel visible light communication between vehicles and vehicles, and vehicles and transportation facilities, a multi-terminal online shared data link network is constructed to achieve real-time information interaction between users and users, and between users and the Internet.

10. The vehicle-mounted visible light communication system based on Micro-LED according to claim 9, characterized in that: include: The transmitting end of the vehicle-mounted visible light communication system includes a transmitting signal input control module, a light transmitter based on a Micro-LED array chip, and a focusing lens; the receiving end includes a focusing lens, a light receiver based on a Micro-LED array chip, and a signal receiving and processing module; The visible light transmission channel is a free space environment; And / or, the Micro-LED array chip adopts on-off keying OOK or orthogonal frequency division multiplexing OFDM modulation, combined with a multiple-input multiple-output MIMO system to achieve high-speed bidirectional visible light communication, expand communication capacity and improve communication transmission rate and responsiveness.

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