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.
The researchers further investigated the electrochemical variables that affect the nanopore size, separation ratio, and emission characteristics of dot LEDs, as well as the effect of solvent type on ultrasonic separation using a sonochemical process.
