Zinc oxide nano-chrysanthemum as field-emission cathode synthesized on n-doped silicon microstructures

ZnO Nano-chrysanthemum arrays are both synthesized on silicon nano-needles and in silicon micro-holes with hydrothermal method. A ZnO Nano-chrysanthemum is a bunch of ZnO nanorods reaches out from one root. The influence of the reaction time has been carefully discussed and the Van der Waals force is regarded as the driving force from one needle to one Nano-chrysanthemum. This configuration helps suppressing the field screen-effect at a relatively high emission tip density. The influence of the reaction time and the concentration of hydrothermal solution on morphology have been carefully discussed. Turn-on fields as low as 3.35 V/μm and 5.25V/μm from ZnO nano-chrysanthemum on silicon nano-needles and in silicon micro-holes are reported, respectively. A field enhancement factor of 5523 is estimated for ZnO nano-chrysanthemum on silicon nano-needles.