GaN Based LED Grown on Nano-pillar Template／Prof. Hao-chung Kuo, Prof. Tien-chang Lu

　We presented a study of high performance GaN-based light emitting diodes (LEDs) using a GaN nano-pillars (NPs) structure grown on sapphire substrate by integrating RF-plasma molecular beam epitaxy (MBE) and metal-organic chemical vapor deposition (MOCVD). Nano-scale air voids were clearly observed at the interface between GaN NPs and the overgrown GaN layer. It can increase the light extraction efficiency due to additional light scattering. The air voids between GaN NPs introduced during nanoscale epitaxial lateral overgrowth (NELOG) of GaN can suppress the threading dislocation density.