Effects of the growth parameters on the hydrothermal synthesis of ZnO nano-rods and their application to GaN based LEDs

Accurate growth control is required to apply ZnO nanorods to devices and materials. This study examined the effects of the growth parameters, such as pressure, growth temperature, growth time, and concentration of the growth solution. The pressure had little influence on ZnO growth. The growth temperature increased length of ZnO nanorods but not affected diameter of ZnO nanorods. The concentration of the growth solution increased the length and diameter of ZnO nanorods. The growth time affected only length of the ZnO nanorods. We confirmed the effect of ZnO nanorods growth parameters successfully and control is possible. The LEDs with ZnO nanorods exhibited improved light extraction efficiency due to the wave manipulation by the ZnO nanorods.