Efficiency Improvement of GaN-Based LEDs With $ \hbox{SiO}_{2}$ Microrod Array and Textured Sidewalls

High-performance nitride-based light-emitting diodes (LEDs) grown with SiO ₂ microrod array have been demonstrated. The light output power of LEDs with SiO ₂ microrod array was 9.03% higher than conventional LEDs at the injection current of 20 mA. The improvement contributed to the enhancement of the light extraction efficiency, and epitaxial GaN film quality improved by direct heteroepitaxial lateral overgrowth with SiO ₂ microrod array. The light output power could be further enhanced by about 18.36% as compared with the conventional LEDs when adopting the textured sidewall surface which use buffered oxide etch to remove SiO ₂ microrod arrays and use NaOH to etch the sidewall again into an inverted pyramid shape. After the texturing process, the LEDs show higher electroluminescence intensity and broader far-field pattern. Furthermore, the LEDs with SiO ₂ microrod array and additional wet-etching process will not affect the electrical property.