Researchers from the Korea Advanced Institute of Science and Technology (KAIST) developed a new process that enables the fabrication of highly dense MicroLED displays - up to 63,500 PPI (!).
The technique involves stacking RGB LEDs in three dimensions and a semiconductor patterning process. Stacking LEDs one on top of the other creates color interference issues, and to overcome this the researchers deposited an insulating film between the layers. This also improved the efficiency of the microLED devices.