Surface conduction electron emission of ZnO nanostructures

This paper describes a study on the surface conduction electron emission of ZnO tetrapods, which were synthesized by the oxidation of Zn vapor. With an insulator of thickness 100 mu m, the turn-on voltage was 540 V in the surface conduction structure and 750 V in the conventional cathode-gate field emission structure. At the same gate voltage, the surface conduction structure had a much larger anode current density. It was found that electrical activation of the ZnO-tetrapod layer greatly enhanced the electron emission. After activation, the turn-on voltage was 40 V, and the emission current density reached 0.49 mA cm(-2) at an applied voltage of 150 V. A preliminary theory on the surface conduction electron emission of ZnO is presented.