Research on Fabrication for nanostructures on the surface of GaN

A novel way to fabricate nanostructures on the GaN surface using a GaN-on-Sapphire system is developed. The direct fabrication of nanostructures on GaN was performed by four interfering nanosecond laser beams with a diffractive beam splitter. It was found that the obtained nanostructures had a negative shape of the interference pattern of four laser beams. The reflection losses at the GaN interfaces are suppressed. The light extraction efficiency is significantly improved for the nanostructured GaN layer. This work provides a very practical approach to fabricate freestanding nanostructures on the GaN-on-Sapphire system for further improving the light extraction efficiency.