Process optimization of full color display pixels fabricated by integration of Micro-LEDs and OLEDs

Journal article, 2026

In micro light-emitting-diodes (Micro-LEDs) full-color display technology, two mainstream solutions are RedGreen-Blue (RGB) heterogeneous integration and Micro-LED-excited quantum dots (QDs) for color conversion. However, these schemes face core challenges: high-cost mass transfer of RGB chips, and insufficient QDs stability in color-conversion solutions. Meanwhile, conventional organic light-emitting diode (OLED) full-color display technology has long been limited by poor blue OLED performance, specifically low brightness and short lifespan, which severely restricts the improvement of display quality. To address these bottlenecks of existing technologies, this study proposes an innovative hybrid architecture. It integrates GaN-based blue Micro-LED arrays with red and green OLEDs, eliminating the need for mass transfer of red and green Micro-LEDs. Through photolithography and high-precision alignment processes, monolithic integration of passive-matrix blue Micro-LEDs (70 & times; 20 mu m2) and red/green OLEDs (70 & times; 90 mu m2) was achieved. Additionally, KOH treatment processes and ITO thickness adjustment were applied to further enhance device performance. Under optimal conditions, the blue Micro-LEDs exhibited a 59.8% increase in relative electroluminescent (EL) intensity and a 92.5% increase in luminance. When driven at 4.5 V, the luminance of the blue Micro-LEDs reached 4.86 & times; 104cd/m2, and at 5 V, the luminance of the red and green OLEDs was 26 cd/m2 and 87 cd/m2, respectively. The turn-on voltage deviation was less than 0.3 V, and the standard RGB (sRGB) color gamut coverage reached 90.89%.