Enhanced light extraction in light-emitting diodes with photonic crystal structure selectively grown on p-GaN

We report on the properties of green light-emitting diodes (LEDs) with a photonic crystal (PC) structure on p-GaN. A PC structure was fabricated by the selective area epitaxy of p-GaN using SiO2 nanopillars. The electrical characteristics of LEDs with PC were not degraded and the optical output power of green LEDs with PC was increased by 70% at 20 mA of injection current compared with that of conventional LEDs without PC. This enhancement of optical output power was attributed to the improvement in light extraction efficiency by the SiO2/p-GaN PC layer on p-GaN.