Nanoscale Vacuum Tube with ZnO nanorods

ZnO nanorods electron emitter was fabricated with the simple solution and hydrothermal process. ZnO can grow to countless nanorods without vacuum process. The ITO glass was used as an anode plate and the ZnO electron emitter as a cathode. The cathode and anode plate were kept apart by spacer with thickness of $10~\mu m$. The current-voltage (I-V) characteristics were measured in the air and in a vacuum in order to determine the performance of ZnO nanorods as the electron emission source. Here we found this device provides a high drive current (>10 micro-amperes) at relatively low drain voltage (10V). This indicates ZnO have high performance for electron emitter.