Highly efficient GaN-based light emitting diodes with micropits

Light emitting diodes (LEDs) on GaN templates with high-density V-shaped micropits have been grown and characterized by transmission electron microscopy, scanning electron microscopy, and photoluminescence. Higher emission efficiency has been obtained for the fabricated LEDs compared with those without V-shaped pits. The high efficiency of the LEDs is mainly attributed to the increase in light extraction efficiency due to the light extraction from the sidewalls of the V-shaped pits. The improved internal quantum efficiency of the device resulting from the reduction of the dislocation density in the light emitting area also contributes to the high efficiency of the LEDs. (c) 2006 American Institute of Physics.