Light Output Enhancement of GaN-Based Light-Emitting Diodes Using ZnO Nanorod Arrays Produced by Aqueous Solution Growth Technique

ZnO nanorod arrays were successfully deposited on GaN-based light-emitting diodes (LEDs) using the aqueous solution growth technique. A 20.3% light output enhancement of the LEDs with ZnO nanorod array was obtained at an injection current of 100 mA. With the presence of the ZnO nanorod array, divergence of the light output was reduced and the light output was confined in a smaller escape cone of about 30 $^{\circ}$ rather than 42 $^{\circ}$ of the conventional LEDs. Current–voltage characteristics and electroluminescence measurements confirmed that there was no significant change in electrical and optical properties of these LEDs with ZnO nanorod arrays.