Fabrication of GaN-based Micro-LED Green Micro-display with High Brightness

Micro-LEDs are a new display technology with advantages including high contrast, fast response, and long lifetimes. Micro-LEDs are currently regarded as an active topic of research. Micro-LED display technology is a promising industry, but its commercialization faces many technical challenges and bottlenecks. This study explores the diode preparation process and related technologies for high-brightness, green-light, GaN-based micro-LED micro-displays. Monochrome green micro-LEDs with resolutions of 800×480 and 0.41 in were fabricated based on the CMOS driver circuit of an all-digital signal circuit. The CMOS driver circuit was connected to an LED chip via high-precision flip bonding. The experimental results showed that the turn-on voltage of the LED was 2.8 V and that the peak wavelength of the electroluminescence spectrum was 524 nm. The maximum brightness of the device can reach 250, 000 cd/m² within the normal driving range of silicon-based CMOS circuits, and the brightness can reach 108, 000 cd/m² at 5 V. When the current density was controlled at 0.61 A/cm², the CIE coordinates were (0.175, 0.756). When the current density was increased from 0.3 A/cm² to 1.3 A/cm², the CIE coordinates changed from (0.178, 0.757) to (0.175, 0.746). The color stability of the device met the requirements for practical applications.