RGB arrays for micro-LED applications using nanoporous GaN embedded with quantum dots.

The multiple light scattering of nanoporous (NP) GaN was systematically studied and applied to the color down-conversion for micro-LED display applications. The transport mean free path (TMFP) in NP GaN is 660 nm at 450 nm (light wavelength) and it decreases with decreasing wavelength. It was observed that the short TMFP of the NP GaN increased the light extinction coefficient at 370 nm by 11 times. Colloidal QDs were loaded into half 4" wafer-scale NP GaN, and 96 and 100% light conversion efficiencies for green and red were achieved, respectively. By loading green and red QDs selectively into NP GaN mesas, we demonstrated the RGB micro-arrays based on the blue-violet pumping light with green and red color converting regions.