Light Output Power Enhancement of GaN-Based Light Emitting Diodes with Periodic Deflector Embedded on the Wet Etch Patterned Sapphire Substrate

In this work, light-emitting diodes (LEDs) are fabricated with periodic deflector embedded (PDE) on the wet etch patterned sapphire substrate (PSS). A wet etching technique is employed to form the PDE-PSS structures. The performance of the PDE and PDE-PSS LEDs were compared with the conventional LEDs. The light output power of the PDE and PDE-PSS LEDs were enhanced by the factor of 40 and 60%, respectively, compared to that obtained from conventional LEDs. The light trajectories that are guided along the epilayer in the LEDs can be extracted by the helps of periodic deflectors as well as a typical PSS structure. (C) 2011 The Japan Society of Applied Physics