Study On Micro-LED For Next-Generation Communication Technologies

As the next-generation communication technology that replaces wireless radio frequency(RF)communication,Visible Light Communication(VLC)utilizes visible light as the transmission medium,offering advantages such as high speed,security,and low power consumption.VLC effectively addresses the development challenges of RF communication,such as limited spectrum resources and restricted transmission power.Conventional commercial LEDs have limited optical modulation bandwidth,which fails to meet the requirements of VLC systems.In contrast,MicroLEDs with higher modulation bandwidth can provide faster transmission rates,making them the most promising competitors as high-speed VLC system light sources.Therefore,this paper focuses on the application of next-generation communication technology and conducts a series of research on MicroLEDs.The specific work is outlined as follows:(1)High-performance gallium nitride(GaN)-based Micro-LED array devices were fabricated through the design of Micro-LED device structures and micro/nano processing schemes.Both a single pixel structure for GaN-based Micro-LED and an independently addressable array device structure were designed.Based on the structural design,photolithography and deposition process masks were designed for the respective processes.Through the exploration of device parameters and fabrication processes,the process flow for device fabrication was established,and a batch of blue/purple GaNbased Micro-LED array devices was successfully fabricated,providing a comprehensive Micro-LED device fabrication solution for high-speed visible light communication(VLC)applications.(2)The optoelectronic performance of the fabricated GaN-based Micro-LED array devices was tested and analyzed.The current-voltage characteristics and array uniformity of the devices were tested using a DC probe station platform.The optical performance of the devices,including electroluminescence spectra,electro-optical conversion efficiency,external quantum efficiency,and radiant flux,was tested using an integrated sphere-based optical efficiency measurement system.The frequency response characteristics of the Micro-LEDs were tested using a visible light communication test system.The results demonstrate that the-3 d B bandwidth of the devices can reach over two hundred megahertz,confirming the superior performance advantage of the fabricated GaNbased Micro-LEDs in terms of high modulation bandwidth,thus providing a high-quality light source selection for visible light communication systems.(3)Silvaco-TCAD was utilized for modeling and simulation of GaN-based Micro-LEDs.Simulation studies on Micro-LEDs were conducted from three aspects: structural parameters of the device,structural design,and novel structures.Specifically,the impact of various parameters such as the aluminum(Al)component in the p-type doped aluminum gallium nitride(p-Al GaN)electron blocking layer,the indium(In)component in the indium gallium nitride(In GaN)/GaN quantum wells,the thickness of the In GaN quantum wells,the number of quantum well periods,and the pixel dimensions of the device were analyzed in detail with respect to the optoelectronic performance of Micro-LEDs.A model of Micro-LEDs with a nano-pillar array structure was designed and constructed to explore the device performance for different nano-pillar array structures.Through simulation calculations,the current-voltage characteristics,electroluminescence power spectral density,internal quantum efficiency,optical power,band structure,and carrier concentration distribution,among other optoelectronic performance metrics,were analyzed in particular for different structural parameter designs of the device.This provides a basis for parameter optimization and theoretical guidance in the design and fabrication of high-performance Micro-LEDs.