Output power enhancement of light-emitting diodes via two-dimensional hole arrays generated by a monolayer of microspheres

Abstract
The output power enhancement of the GaN-based light-emitting diodes(LEDs) featuring two-dimensional (2D) hole arrays is demonstrated. The 2D air hole arrays were first generated in the photoresist by utilizing the focusing nature of microspheres, and then transferred onto the GaNsurface through dry etching. The maximum output power of the surface-textured LEDs was enhanced by 45% compared with the LEDs without surface texturing. The finite-difference time-domain calculation was performed and revealed that the light extraction efficiency of the textured LEDs increased with increasing etching depth.