Research On Micro-LED Array Theory And Display Technology

Light-emitting diodes(LEDs)are widely used in the field of lighting and display with the advantages of high brightness,long life,fast response speed and environmental protection.In recent years,the combination of semiconductor micro-nano manufacturing technology and LED technology has enabled LED display technology to develop rapidly in the direction of micro-display and high resolution.Micro-LEDs with characteristic dimensions on the order of micrometers have received widespread attention internationally.Compared with OLED and LCD technologies,Micro-LED has many excellent characteristics,such as higher brightness,resolution and color saturation,lower energy consumption,longer life and faster response speed,and has a broad application prospects.The Micro-LED array is a two-dimensional array of high-density,micro-sized LEDs integrated in a small area.Due to its advantages of micro-size and high brightness,it can be applied in many fields such as high-resolution display,lensless microscope,super-resolution microscope,optical tweezers,optical nerve interface,maskless lithography and visible light communication.At the same time,with the upgrading of demand,full-color Micro-LED array devices have also entered people's field of vision.Full-color display devices have a wider range of applications,such as panel displays,head-up displays(HUD),augmented reality(AR),virtual reality(VR),smart watches,and smart phones.This article has carried out research on the array theory and display technology of Micro-LED.The specific work can be divided into the following parts:(1)The photoelectric characteristics of Micro-LED devices were studied.Through finite element simulation,the influence of electrode structure and size on the photoelectric characteristics of Micro-LED is analyzed,and a method to improve the electro-optical conversion efficiency by arraying Micro-LED is proposed.Through finite element simulation,the large-size 40?m,80?m and 160?m Micro-LEDs are formed into 2×2 small-sized Micro-LEDs of 20?m,40?m and 80?m.Comparative analysis of the corresponding photoelectric characteristics shows that due to the improvement of current density distribution and heat dissipation capacity,the arrayed Micro-LEDs have higher peak light power than large-size Micro-LEDs with the same light-emitting area.(2)The preparation process of Micro-LED array devices was experimentally studied.The influence of the mask on the ICP etching and the influence of the deposition method on the deposition of the silicon dioxide dielectric layer are analyzed,and through ICP mesa etching,N electrode deposition,silicon dioxide deposition,and P electrode deposition,a flip-chip blue Micro-LED display array with a pixel size of10?m × 10?m and an array number of 6×6 that can be driven individually is fabricated.(3)The three-color integrated Micro-LED full color display array device was studied.First,the overall structure and process flow of the full-color Micro-LED array display device are designed.Then design and fabricate a patterned metal internal drive circuit on a silicon substrate,and integrate red,green and blue monochromatic MicroLEDs on the silicon substrate to form a full-color Micro-LED array device through transfer printing.The red,green,and blue Micro-LEDs are all flip-chip structures,and the red Micro-LEDs are manufactured by substrate transfer,mesa etching,metal deposition and chip dicing.The device is driven and displayed by an external drive circuit to complete the production of a 48×48 full-color pixelized addressable MicroLED display device.(4)The research on monolithic integrated Micro-LED full-color display array device was carried out,and a new method for fabricating quantum dot color conversion layer for Micro-LED full-color display by microfluidic technology was proposed.Three kinds of perovskite quantum dot color conversion layers with full-color pixel unit sizes of 400 ?m and 200 ?m and array numbers of 10×10 and 20×20 were fabricated by the microfluidic method.The produced perovskite quantum dots have high-efficiency luminescence properties,with green light quantum yields up to 90%,FWHM up to14.2nm,red light quantum yields up to 51%,and FWHM up to 23.8nm.By adjusting the concentration of perovskite quantum dots,2mg/m L red and green perovskite quantum dots can be obtained with the best performance,and the corresponding quantum dot color conversion layer color space coverage rate is 131% NTSC,which has better display effect.