Efficiency Enhancement of GaN-Based Power-Chip LEDs with Sidewall Roughness by Natural Lithography

This study reports the development of GaN-based power-chip light-emitting diodes (LEDs) with sidewall roughness using natural lithography with polystyrene spheres as the etching mask. At an injection current of 350 mA , the LED with sidewall roughness increased the light output intensity of the In Ga N ∕ Ga N multiple quantum well LEDs by a factor of 1.26, indicating that the LED with sidewall roughness had larger light extraction efficiency. The wall-plug efficiency of GaN-based LED was increased by 26.5% with sidewall roughness. After 1000 h life test, it was found that normalized output power of power-chip LED with sidewall roughness did not show any significant degradation.