Kookmin University

Researchers from Korea's Kookmin University have developed a new GaN-based fin-LED chip material and pixel process technology, saying that this innovation may be the key to overcome the limitations of current microLED technologies.

The researchers developed a viable pixel manufacturing process that vertically assembles sub-micron-sized fin-LEDs using a face-selective dielectrophoresis (DEP) assembly method. The GaN-based sub-micron-sized fin-LEDs are designed to maximize performance while minimizing costs related to the chips and pixelation process. This technology significantly enhances extraction light efficiency by vertically aligning the fin-LEDs, and it enables the implementation of chip materials and pixel manufacturing processes that significantly reduce production costs.

Researchers from Korea's Kookmin University in Seoul, led by Prof. Young Rag Do, have developed a novel top-down process to fabricate and isolate sub-micron GaN microLEDs. The process combines electrochemical etching and sonochemical separation of the etched porous layer to isolate the microLEDs.

The researchers have used the process to produce Au-coated GaN blue LEDs that offer an EQE of 6.21% (at 4.0 V) and a luminous efficacy of 1,070 cd/m2 (at 10.0 V). The LEDs themselves had a diameter of 750 nm, these are true sub-micon LEDs.

Researchers from Korea's Kookmin University in collaboration with colleagues from Kyung Hee University have managed to enhance the performance of microLEDs produced using fluidic self-assembly based on chelation bonds of chemical linkers. The researcher report up to 61.8% increase in assembly yield compared to previous methods, and their vertically assembled 1.3 um microLEDs achieved a peak EQE of 8.1% and a brightness of 22,300 nits at 9 V.

The researchers developed a novel approach for the face-selective vertical assembly of microLEDs using a chemical linker capable of engaging in metal chelate coordination interactions within Zn metal complexes.