Light extraction enhancement in GaN-based vertical light-emitting diodes with hemispherical bumps

Abstract

Ion beam etching technology was applied to the surfaces of GaN-based vertical light-emitting diodes (V-LEDs). The ability to control morphology using this technology resulted in very uniform, hexagonal, closely packed hemispherical bumps on the n-type GaN layer. The textured V-LEDs showed a remarkable increase (130%) in light output power compared to the original, and no electrical deterioration was noted. This study demonstrates that ion beam etching is an effective approach for fabricating hemispherical bumps to achieve increased light extraction efficiency in GaN-based V-LEDs, and potentially other optical devices.