2018 Volume 126 Issue 5 Pages 367-371
The room temperature growth of ZnO nanoneedle arrays on seed layers was demonstrated via wet-chemical synthesis. The orientation of ZnO nanoneedles was found to be extremely high on the flat seed layer with high crystallinity, whereas a poor orientation was observed on rough seed layers. We expect that the direction of ZnO  (c-axis) dictates the orientation of ZnO nanoneedles. With longer reaction time, ZnO nanoneedles grew dominantly in a length compared to a diameter. Dense ZnO nanoneedles with a high orientation is believed to be promising for many applications in optelectronics and photonics.